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Sample records for permeation remains unclear

  1. Treatment-related changes in serum lipids and inflammation: clinical relevance remains unclear. Analyses from the Women's Interagency HIV Study

    Science.gov (United States)

    Parrinello, Christina M; Landay, Alan L; Hodis, Howard N; Gange, Stephen J; Norris, Philip J; Young, Mary; Anastos, Kathryn; Tien, Phyllis C; Xue, Xiaonan; Lazar, Jason; Benning, Lorie; Tracy, Russell P; Kaplan, Robert C

    2014-01-01

    Summary Among 127 HIV-infected women, the magnitude of HDLc increases after HAART initiation predicted the magnitude of concurrent decreases in inflammation biomarkers. After HAART initiation, changes in LDLc and inflammation were unrelated. In the same population, predicted risk of coronary heart disease based upon levels of standard clinical risk factors was similar before and after HAART treatment. Thus, it remains unknown whether short-term treatment-related changes in standard risk factors may appreciably change risk of CVD. PMID:23435295

  2. Fate of nuclear waste site remains unclear

    International Nuclear Information System (INIS)

    Anderson, E.V.

    1980-01-01

    The only commercial nuclear fuel reprocessing plant in the U.S., located in West Valley, N.Y., has been shut down since 1972, and no efforts have yet been made to clean up the site. The site contains a spent-fuel pool, high level liquid waste storage tanks, and two radioactive waste burial grounds. Nuclear Fuel Services, Inc., has been leasing the site from the New York State Energy RandD Authority. Federal litigation may ensue, prompted by NRC and DOE, if the company refuses to decontaminate the area when its lease expires at the end of 1980. DOE has developed a plan to solidify the liquid wastes at the facility but needs additional legislation and funding to implement the scheme

  3. The Performance of Public Organization: Still Unclear

    Directory of Open Access Journals (Sweden)

    Bacanu B.

    2014-12-01

    Full Text Available Nowadays, the present discussions about the organisation’s performance have revealed the fact that the concept is unclear. The use of the concept is more difficult in public organisations. The paper presents the case of Romanian SOE Hidroelectrica and the case of public universities, to pinpoint the fact that ambiguous objectives are the cause of a dilemmatic management. The general opinion is that the results of the public organisations management reflect a poor performance of the latter.

  4. On Diffusion and Permeation

    KAUST Repository

    Peppin, Stephen S. L.

    2009-01-01

    concentrations they form a nearly rigid porous glass through which the fluid permeates. The theoretically determined pressure drop is nonlinear in the diffusion regime and linear in the permeation regime, in quantitative agreement with experimental measurements

  5. Permeation through graphene ripples

    Science.gov (United States)

    Liang, Tao; He, Guangyu; Wu, Xu; Ren, Jindong; Guo, Hongxuan; Kong, Yuhan; Iwai, Hideo; Fujita, Daisuke; Gao, Hongjun; Guo, Haiming; Liu, Yingchun; Xu, Mingsheng

    2017-06-01

    Real graphene sheets show limited anti-permeation performance deviating from the ideally flat honeycomb carbon lattice that is impermeable to gases. Ripples in graphene are prevalent and they could significantly influence carrier transport. However, little attention has been paid to the role of ripples in the permeation properties of graphene. Here, we report that gases can permeate through graphene ripples at room temperature. The feasibility of gas permeation through graphene ripples is determined by detecting the initial oxidation sites of Cu surface covered with isolated graphene domain. Nudged elastic band (NEB) calculations demonstrate that the oxygen atom permeation occurs via the formation of C-O-C bond, in which process the energy barrier through the rippled graphene lattice is much smaller than that through a flat graphene lattice, rendering permeation through ripples more favorable. Combining with the recent advances in atoms intercalation between graphene and metal substrate for transfer-free and electrically insulated graphene, this discovery provides new perspectives regarding graphene’s limited anti-permeation performance and evokes for rational design of graphene-based encapsulation for barrier and selective gas separation applications through ripple engineering.

  6. Tritium permeation through iron

    International Nuclear Information System (INIS)

    Hagi, Hideki; Hayashi, Yasunori

    1989-01-01

    An experimental method for measuring diffusion coefficients and permeation rates of tritium in metals around room temperature has been established, and their values in iron have been obtained by using the method. Permeation rates of tritium and hydrogen through iron were measured by the electrochemical method in which a tritiated aqueous solution was used as a cathodic electrolyte. Tritium and hydrogen were introduced from one side of a membrane specimen by cathodic polarization, while at the other side of the specimen the permeating tritium and hydrogen were extracted by potentiostatical ionization. The amount of permeated hydrogen was obtained by integrating the anodic current, and that of tritium was determined by measuring the radioactivity of the electrolyte sampled from the extraction side. Diffusion coefficients of tritium (D T ) and hydrogen (D H ) were determined from the time lag of tritium and hydrogen permeation. D T =9x10 -10 m 2 /s and D H =4x10 -9 m 2 /s at 286 K for annealed iron specimens. These values of D T and D H were compared with the previous data of the diffusion coefficients of hydrogen and deuterium, and the isotope effect in diffusion was discussed. (orig.)

  7. On Diffusion and Permeation

    KAUST Repository

    Peppin, Stephen S. L.

    2009-01-01

    Diffusion and permeation are discussed within the context of irreversible thermodynamics. A new expression for the generalized Stokes-Einstein equation is obtained which links the permeability to the diffusivity of a two-component solution and contains the poroelastic Biot-Willis coefficient. The theory is illustrated by predicting the concentration and pressure profiles during the filtration of a protein solution. At low concentrations the proteins diffuse independently while at higher concentrations they form a nearly rigid porous glass through which the fluid permeates. The theoretically determined pressure drop is nonlinear in the diffusion regime and linear in the permeation regime, in quantitative agreement with experimental measurements. © 2009 Walter de Gruyter, Berlin, New York.

  8. Simplified tritium permeation model

    International Nuclear Information System (INIS)

    Longhurst, G.R.

    1993-01-01

    In this model I seek to provide a simplified approach to solving permeation problems addressed by TMAP4. I will assume that there are m one-dimensional segments with thickness L i , i = 1, 2, hor-ellipsis, m, joined in series with an implantation flux, J i , implanting at the single depth, δ, in the first segment. From material properties and heat transfer considerations, I calculate temperatures at each face of each segment, and from those temperatures I find local diffusivities and solubilities. I assume recombination coefficients K r1 and K r2 are known at the upstream and downstream faces, respectively, but the model will generate Baskes recombination coefficient values on demand. Here I first develop the steady-state concentration equations and then show how trapping considerations can lead to good estimates of permeation transient times

  9. Fermentation of lactose to ethanol in cheese whey permeate and concentrated permeate by engineered Escherichia coli.

    Science.gov (United States)

    Pasotti, Lorenzo; Zucca, Susanna; Casanova, Michela; Micoli, Giuseppina; Cusella De Angelis, Maria Gabriella; Magni, Paolo

    2017-06-02

    Whey permeate is a lactose-rich effluent remaining after protein extraction from milk-resulting cheese whey, an abundant dairy waste. The lactose to ethanol fermentation can complete whey valorization chain by decreasing dairy waste polluting potential, due to its nutritional load, and producing a biofuel from renewable source at the same time. Wild type and engineered microorganisms have been proposed as fermentation biocatalysts. However, they present different drawbacks (e.g., nutritional supplements requirement, high transcriptional demand of recombinant genes, precise oxygen level, and substrate inhibition) which limit the industrial attractiveness of such conversion process. In this work, we aim to engineer a new bacterial biocatalyst, specific for dairy waste fermentation. We metabolically engineered eight Escherichia coli strains via a new expression plasmid with the pyruvate-to-ethanol conversion genes, and we carried out the selection of the best strain among the candidates, in terms of growth in permeate, lactose consumption and ethanol formation. We finally showed that the selected engineered microbe (W strain) is able to efficiently ferment permeate and concentrated permeate, without nutritional supplements, in pH-controlled bioreactor. In the conditions tested in this work, the selected biocatalyst could complete the fermentation of permeate and concentrated permeate in about 50 and 85 h on average, producing up to 17 and 40 g/l of ethanol, respectively. To our knowledge, this is the first report showing efficient ethanol production from the lactose contained in whey permeate with engineered E. coli. The selected strain is amenable to further metabolic optimization and represents an advance towards efficient biofuel production from industrial waste stream.

  10. Value of prophylactic antibiotics for invasive dental procedures unclear.

    Science.gov (United States)

    Rochlen, Glenn K; Keenan, Analia Veitz

    2014-03-01

    The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, the US National Institutes of Health Trials Register and the metaRegister of Controlled Trials. Randomised controlled trials (RCTs) and controlled clinical trials (CCTs) would be included where available. Due to the low incidence of bacterial endocarditis it was anticipated that few such trials would be found. Cohort and case-control studies were included where suitably matched control or comparison groups had been studied. Two review authors independently selected studies for inclusion then assessed risk of bias and extracted data from the included study. Only one case controlled study met the inclusion criteria. It collected all the cases of endocarditis in the Netherlands over two years, finding a total of 24 people who developed endocarditis within 180 days of an invasive dental procedure, definitely requiring prophylaxis according to current guidelines, and who were at increased risk of endocarditis due to a pre-existing cardiac problem. This study included participants who died because of the endocarditis (using proxies). Controls attended local cardiology outpatient clinics for similar cardiac problems, had undergone an invasive dental procedure within the past 180 days, and were matched by age with the cases. No significant effect of penicillin prophylaxis on the incidence of endocarditis could be seen. No data were found on other outcomes. There remains no evidence that antibiotic prophylaxis is either effective or ineffective against bacterial endocarditis in people considered at risk who are about to undergo an invasive dental procedure. It is not clear whether the potential harms and costs of penicillin administration outweigh any beneficial effect. Ethically, practitioners need to discuss the potential benefits and harms of antibiotic prophylaxis with their patients before a decision is made about administration.

  11. Tritium permeation and recovery

    International Nuclear Information System (INIS)

    Bond, R.A.; Hamilton, A.M.

    1987-01-01

    The paper is an appendix to a study of the reactor relevance of the NET design concept. The latter study examines whether the technologies and design principles proposed for NET can be directly extrapolated to a demonstration (DEMO) reactor. In this appendix, tritium transport in the DEMO breeding blanket is considered with emphasis on the permeation rate from the lithium-lead breeder into the coolant. A computational model used to calculate the tritium transport in the breeder blanket is described. Results are reported for the tritium transport in the NET/INTOR type blanket as well as the DEMO blanket in order to provide a comparison. In addition, results are presented for the helium coolant tritium extraction analysis. (U.K.)

  12. In-pile tritium permeation experiment

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Miller, L.G.; Watts, K.D.; Kershner, C.J.; Rogers, M.L.

    1982-01-01

    The experiments in progress are examining various aspects of the permeation of hydrogen isotopes through fusion materials. Of particular importance will be the measurement of permeation due to ion implantation in the presence of a neutron radiation field. Theoretical and early experimental results for these experiments have suggested that sufficient tritium will permeate fusion reactor interior structures that development of a permeation barrier will be needed. (orig.)

  13. In-pile tritium permeation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Longhurst, G.R.; Miller, L.G.; Watts, K.D. (Idaho National Engineering Lab., Idaho Falls (USA)); Kershner, C.J.; Rogers, M.L. (Monsanto Research Corp., Miamisburg, OH (USA). Mound Facility)

    The experiments in progress are examining various aspects of the permeation of hydrogen isotopes through fusion materials. Of particular importance will be the measurement of permeation due to ion implantation in the presence of a neutron radiation field. Theoretical and early experimental results for these experiments have suggested that sufficient tritium will permeate fusion reactor interior structures that development of a permeation barrier will be needed.

  14. Role of lymphoscintigraphy in diagnosis and management of patients with leg swelling of unclear etiology

    International Nuclear Information System (INIS)

    Kalawat, Tek Chand; Chittoria, Ravi Kumar; Reddy, Praveen Kumar; Suneetha, Batchu; Narayan, Ravishwar; Ravi, Parthsarthi

    2012-01-01

    To study the utility of lymphoscintigraphy in detection of lymphatic obstruction in patients with leg swelling of unclear etiology, selection of site for nodo venous shunt procedure, and follow-up lymphoscintigraphic documentation of improved lymph flow in surgically treated limb. Twenty four consecutive patients with leg swelling, 10 male, 14 female with mean age 47 years, range from 13 years to 74 years underwent lymphoscintigraphy. All patients were referred from Department of Plastic Surgery, after initial work-up, and routine investigations to rule out the other causes of leg swelling. Both clinical and scintigraphic staging performed for all patients. All clinically and scintigraphically positive patients treated with decongestive lymphatic therapy (DLT). In addition to the DLT, those patients positive for unilateral or bilateral lymphedema, consented for surgical intervention, nodo venous shunt (NVS) in their only affected or one of the two affected lower limbs. Follow-up lymphoscintigraphy performed in operated cases after 3 months to 6 months of surgery, lymphoscintigraphy images of each patient in pre and post-surgery compared. In 20/24 cases (83%) of clinically positive leg swelling were found to be positive for lymphedema on lymphoscintigraphy and remaining, 4/24 were scintigraphically normal. Based on the clinical and lymphoscintigraphy staging, 03/20 cases (15%) had Grade I lymphedema, 01/20 (5%) Grade II lymphedema, 06/20 (30%) Grade III and remaining 10/20 (50%) had Grade IV lymphedema. 11/20 cases of Lymphedema (55%) were managed conservatively by only DLT and in remaining 09/20 cases (45%), who were case of Grade IV, lymphedema (five patients with unilateral and four patients with bilateral disease) initially treated with DLT, and on completion of DLT, undergone for NVS procedure, in their unilaterally affected lower limb or one of the two diseased lower limbs. All nine patients showed remarkable clinical improvement in leg swelling and their

  15. Hydrogen permeation preventive structural materials

    International Nuclear Information System (INIS)

    Fukushima, Kimichika; Nakahigashi, Shigeo; Imura, Masashi; Terasawa, Michitaka; Ebisawa, Katsuyuki.

    1986-01-01

    Purpose: To provide highly practical wall materials for use in thermonuclear reactors capable of effectively preventing the permeation of hydrogen isotopes such as tritium thereby preventing the contamination of coolants. Constitution: Helium gas is injected into or at the surface of base materials comprising stainless steel plates to form a helium gas region. Alternatively, boron, nitrogen or the compound thereof having a greater helium forming nuclear reaction cross section than that of the base materials is mixed or injected into the base material to form the helium gas region through (n,α) reaction under neutron irradiation. Since the helium gas region constitutes a diffusion barrier for the tritium as the hydrogen isotope, the permeation amount of tritium is significantly suppressed. Helium gas bubbles or lattice defects are formed in the helium gas region under the neutron irradiation, by which the hydrogen isotope capturing effect can also be effected. In this way, permeation of the hydrogen isotope, contamination of the coolants, etc. can be prevented to provide great practical effectives. (Kawakami, Y.)

  16. Deuterium permeation through Flibe facing materials

    International Nuclear Information System (INIS)

    Fukada, S.; Anderl, R.A.; Smolik, G.R.

    2004-01-01

    Experiment of deuterium permeation through Ni facing with purified Flibe is being carried out under the Japan-US joint research project (JUPITER-II). The experiment has been proceeding in the following phases; (i) fabrication and assembly of a dual-probe permeation apparatus, (ii) a single-probe Ni/D 2 , permeation experiment without Flibe, (iii) a dual-probe Ar/Ni/D 2 permeation experiment without Flibe, (iv) Flibe chemical purification by HF/H 2 gas bubbling, (v) physical purification by Flibe transport through a porous Ni filter, (vi) Ar/Ni/Flibe/Ni/D 2 permeation experiment using the dual Ni probe, and (vii) Ar/Ni/Flibe/Ni/HT permeation experiment. The present paper describe results until the Ar/Ni/Flibe/Ni/D 2 permeation experiment in detail. (author)

  17. Permeation behavior of deuterium implanted into beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hirofumi; Hayashi, Takumi; O' hira, Shigeru; Nishi, Masataka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-09-01

    Study on Implantation Driven Permeation (IDP) behavior of deuterium through pure beryllium was investigated as a part of the research to predict the tritium permeation through the first wall components ITER (International Thermonuclear Experimental Reactor). The permeation experiments were carried out with two beryllium specimens, one was an unannealed specimen and the other was that annealed at 1173 K. The permeation flux was measured as a function of specimen temperature and incident ion flux. Surface analysis of specimen was also carried out after the permeation experiment. Permeation was observed only with the annealed specimen and no significant permeation was observed with unannealed specimen under the present experimental condition (maximum temperature: 685 K, detection limit: 1x10{sup 13} D atoms/m{sup 2}s). It could be attributed that the intrinsic lattice defects, which act as diffusion preventing site, decreased with the specimen annealing. Based on the result of steady and transient permeation behavior and surface analysis, it was estimated that the deuterium permeation implanted into annealed beryllium was controlled by surface recombination due to the oxide layer on the surface of the permeated side. (author)

  18. Hydrogen permeation through metallic foils

    International Nuclear Information System (INIS)

    Bernardi, M.I.B.; Rodrigues, J.A.

    1987-01-01

    The process of electrolytic permeation of hydrogen through metallic foils is studied. A double electrolytic cell, in glass, in which the two compartments of reaction are separated by a metallic foil to be studied, was built. As direct result, the hydrogen diffusion coefficient in the metal is obtained. The hydrogen diffusion coefficients in the palladium and, in austenitic stainless steels 304 and 304 L, used in the Angra-1 reactor, were obtained. Samples of stainless steels with and without welding, were used. (Author) [pt

  19. Tritium permeation in fusion reactors: INTOR

    International Nuclear Information System (INIS)

    Baskes, M.I.; Bauer, W.; Kerst, R.A.; Swansiger, W.A.; Wilson, K.L.

    1981-12-01

    Tritium permeation through the first wall of advanced fusion reactors is examined. A fraction of the D-T which bombards the first wall as charge exchange neutral particles will permeate through the first wall and enter the coolant. Calculations of the steady state permeation rate for the US INTOR Tokamak design result in values of less than or equal to 0.002 grams of tritium per day under the most favorable conditions. For unfavorable surface conditions the rate is greater than or equal to 0.1 g/day. The magnitude of these permeation rates is critically dependent on the temperatures and surface conditions of the wall. The introduction of permeation barriers at the wall-coolant interface can significantly reduce permeation rates and hence may be desirable for reactor applications

  20. Water permeation through anion exchange membranes

    Science.gov (United States)

    Luo, Xiaoyan; Wright, Andrew; Weissbach, Thomas; Holdcroft, Steven

    2018-01-01

    An understanding of water permeation through solid polymer electrolyte (SPE) membranes is crucial to offset the unbalanced water activity within SPE fuel cells. We examine water permeation through an emerging class of anion exchange membranes, hexamethyl-p-terphenyl poly (dimethylbenzimidazolium) (HMT-PMBI), and compare it against series of membrane thickness for a commercial anion exchange membrane (AEM), Fumapem® FAA-3, and a series of proton exchange membranes, Nafion®. The HMT-PMBI membrane is found to possess higher water permeabilities than Fumapem® FAA-3 and comparable permeability than Nafion (H+). By measuring water permeation through membranes of different thicknesses, we are able to decouple, for the first time, internal and interfacial water permeation resistances through anion exchange membranes. Permeation resistances on liquid/membrane interface is found to be negligible compared to that for vapor/membrane for both series of AEMs. Correspondingly, the resistance of liquid water permeation is found to be one order of magnitude smaller compared to that of vapor water permeation. HMT-PMBI possesses larger effective internal water permeation coefficient than both Fumapem® FAA-3 and Nafion® membranes (60 and 18% larger, respectively). In contrast, the effective interfacial permeation coefficient of HMT-PMBI is found to be similar to Fumapem® (±5%) but smaller than Nafion®(H+) (by 14%).

  1. 'NTA', a locally named unclear condition that causes failure to thrive ...

    African Journals Online (AJOL)

    'NTA', a locally named unclear condition that causes failure to thrive amongst under five children in southeastern Nigeria: An assessment of mothers' and caregivers' perception of its causes and management.

  2. Implanted-tritium permeation experiments

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Holland, D.F.; Casper, L.A.; Hsu, P.Y.; Miller, L.G.; Schmunk, R.E.; Watts, K.D.; Wilson, C.J.; Kershner, C.J.; Rogers, M.L.

    1982-04-01

    In fusion reactors, charge exchange neutral atoms of tritium coming from the plasma will be implanted into the first wall and other interior structures. EG and G Idaho is conducting two experiments to determine the magnitude of permeation into the coolant streams and the retention of tritium in those structures. One experiment uses an ion gun to implant deuterium. The ion gun will permit measurements to be made for a variety of implantation energies and fluxes. The second experiment utilizes a fission reactor to generate a tritium implantation flux by the 3 He(n,p) 3 H reaction. This experiment will simulate the fusion reactor radiation environment. We also plan to verify a supporting analytical code development program, in progress, by these experiments

  3. Permeation Tests on Polypropylene Fiber Materials

    Science.gov (United States)

    2018-03-16

    Permeation Tests on Polypropylene Fiber Materials Brandy J. White Martin H. Moore Brian J. Melde Laboratory for the Study of Molecular Interfacial...ABSTRACT Permeation Tests on Polypropylene Fiber Materials Brandy J. White, Martin H. Moore, Brian J. Melde Center for Bio/Molecular Science

  4. THE MODEL OF UNCLEAR EXPERT SYSTEM OF PROGNOSTICATION THE CONTENT OF EDUCATION

    Directory of Open Access Journals (Sweden)

    Ivan M. Tsidylo

    2012-12-01

    Full Text Available The article deals with the problem of development of the expert system of prognostication of the educational content by means of fuzzy logic. It was the model of making decision by the group of experts in accordance to meaningfulness of the theme in the educational programme on the base of the hierarchical system that combines in itself the use of both unclear and stochastic data. The structure of the unclear system, function and mechanisms of construction of separate blocks of the model are described. The surface of review of the unclear system represents dependence of estimation of the theme meaningfulness on the level of competence of group of experts and size to the point at the permanent value of level’s variation. The testing of the controller on a test selection proves the functional fitness of the developed model.

  5. Unclear-onset intracerebral hemorrhage: Clinical characteristics, hematoma features, and outcomes.

    Science.gov (United States)

    Inoue, Yasuteru; Miyashita, Fumio; Koga, Masatoshi; Minematsu, Kazuo; Toyoda, Kazunori

    2017-12-01

    Background and purpose Although unclear-onset ischemic stroke, including wake-up ischemic stroke, is drawing attention as a potential target for reperfusion therapy, acute unclear-onset intracerebral hemorrhage has been understudied. Clinical characteristics, hematoma features, and outcomes of patients who developed intracerebral hemorrhage during sleep or those with intracerebral hemorrhage who were unconscious when witnessed were determined. Methods Consecutive intracerebral hemorrhage patients admitted within 24 hours after onset or last-known normal time were classified into clear-onset intracerebral hemorrhage and unclear-onset intracerebral hemorrhage groups. Outcomes included initial hematoma volume, initial National Institutes of Health Stroke Scale score, hematoma growth on 24-hour follow-up computed tomography, and vital and functional prognoses at 30 days. Results Of 377 studied patients (122 women, 69 ± 11 years old), 147 (39.0%) had unclear-onset intracerebral hemorrhage. Patients with unclear-onset intracerebral hemorrhage had larger hematoma volumes (p = 0.044) and higher National Institutes of Health Stroke Scale scores (p Hematoma growth was similarly common between the two groups (p = 0.176). There were fewer patients with modified Rankin Scale (mRS) scores of 0-2 (p = 0.033) and more patients with mRS scores of 5-6 (p = 0.009) and with fatal outcomes (p = 0.049) in unclear-onset intracerebral hemorrhage group compared with clear-onset intracerebral hemorrhage as crude values, but not after adjustment. Conclusions Patients with unclear-onset intracerebral hemorrhage presented with larger hematomas and higher National Institutes of Health Stroke Scale scores at emergent visits than those with clear-onset intracerebral hemorrhage, independent of underlying characteristics. Unclear-onset intracerebral hemorrhage patients showed poorer 30-day vital and functional outcomes than clear-onset intracerebral hemorrhage patients

  6. 76 FR 23732 - Margin Requirements for Uncleared Swaps for Swap Dealers and Major Swap Participants

    Science.gov (United States)

    2011-04-28

    ... the currency in which payment obligations under the swap are required to be settled; Any obligation... RIN 3038--AC97 Margin Requirements for Uncleared Swaps for Swap Dealers and Major Swap Participants... the Commission to adopt capital and initial and variation margin requirements for certain swap dealers...

  7. 78 FR 66621 - Protection of Collateral of Counterparties to Uncleared Swaps; Treatment of Securities in a...

    Science.gov (United States)

    2013-11-06

    ... or MSP may not have that information. \\45\\ Several commenters highlighted the importance of have the... Swaps Customer Account constitute ``customer property''; and owners of such account constitute ``customers.'' DATES: Effective date: This rule is effective January 6, 2014. Compliance dates: For uncleared...

  8. Effect of pressure sensitive adhesive and vehicles on permeation of terbinafine across porcine hoof membrane.

    Science.gov (United States)

    Ahn, Tai Sang; Lee, Jung-Phil; Kim, Juhyun; Oh, Seaung Youl; Chun, Myung-Kwan; Choi, Hoo-Kyun

    2013-11-01

    The purpose of this study was to investigate characteristics of transungual drug delivery and the feasibility of developing a drug-in-adhesive formulation of terbinafine. The permeation of terbinafine from a PSA matrix across porcine hoof membrane was determined using a plate containing poloxamer gel. The permeation rate of terbinafine across hairless mouse skin was evaluated using a flow-through diffusion cell system. The permeation of terbinafine across the hoof membranes was the highest from the silicone adhesive matrix, followed by PIB, and most of the acrylic adhesives, SIS, and SBS. The rank order of permeation rate across mice skin was different from the rank order across porcine hooves. The amount of terbinafine permeated across the porcine hoof membranes poorly correlated with the amount of terbinafine remaining inside the hooves after 20 days, however, the ratio between rate of terbinafine partitioning into the hoof membrane and its rate of diffusion across the membrane was relatively constant within the same type of PSA. For influence of various vehicles in enhancing permeation of terbinafine across the hoof membrane, all vehicles except Labrasol(®) showed tendency to improve permeation rate. However, the enhancement ratio of a given vehicle differed from one adhesive to another with a moderate correlation between them. The infrared spectrum of the hoof treated with NMP, PPG 400 or PEG 200 indicated that the conformation of keratin changed from a non-helical to a helical structure.

  9. Permeation of hydrogen through metal membranes

    International Nuclear Information System (INIS)

    Wienhold, P.; Rota, E.; Waelbroeck, F.; Winter, J.; Banno, Tatsuya.

    1986-08-01

    Experiments show that the permeant flux of hydrogen through a metal membrane at low driving pressures ( r is introduced into the model as a new material constant and the rate equations are given. After the description of the wall pump effect, a variety of different limiting cases are discussed for a symmetrical permeation membrane. This is modified to the asymmetric case and to the influence of particle implantation. The permeation number W turns out to be a dimensionless quantity which characterizes the permeation range and predicts the permeant flux in steady state. (orig.)

  10. Forced freedom. Part 6. The large-scale consumer. Natural gas trade laborious en unclear

    International Nuclear Information System (INIS)

    Kop, L.

    2001-01-01

    Many organisations are busy taking care of their natural gas purchase. Data are compiled, profiles studied, and possibilities for peak shaving examined. Because of the unknown subject, many companies consult specialised advisers. All in all a lot of work, the more so while much is still unclear. One good advice is to ask the VEMW, a Dutch association for the industrial users of energy, environment and water. VEMW has insight into market prices and related conditions

  11. Permeation of deuterium implanted into vanadium alloys

    International Nuclear Information System (INIS)

    Anderl, R.A.; Longhurst, G.R.; Struttmann, D.A.

    1986-05-01

    Permeation of deuterium through the vanadium alloy, V-15Cr-5Ti, was investigated using 3-keV, D 3 + ion beams from a small accelerator. The experiments consisted of measurements of the deuterium reemission and permeation rates as a function of implantation fluence for 0.5-mm thick specimens heated to tempertures from 623 to 823 0 K. Implantation-side surface characterization was made by simultaneous measurements of sputtered ions with a secondary ion mass spectrometer (SIMS). Analyses of these measurements indicate that for the experimental conditions used, the steady-state deuterium permeation flux in V-15Cr-5Ti is approximately 18% of the implantation flux. This corresponds to approximately 1000 times that seen in the ferritic steel, HT-9, under comparable conditions. Measurement of deuterium diffusivity in V-15Cr-5Ti using permeation break-through times indicates D = 1.4 x 10 -8 exp(-.11 eV/kT) (m 2 /s)

  12. Dissolution and permeation characteristics of artemether tablets ...

    African Journals Online (AJOL)

    characterized by delayed drug release but enhanced permeation of the released drug. Keywords: ... and prosopis gum as binders and to consider the relationship between ..... higher tensile strength and higher brittle fracture index compared ...

  13. Proton permeation of lipid bilayers.

    Science.gov (United States)

    Deamer, D W

    1987-10-01

    Proton permeation of the lipid bilayer barrier has two unique features. First, permeability coefficients measured at neutral pH ranges are six to seven orders of magnitude greater than expected from knowledge of other monovalent cations. Second, proton conductance across planar lipid bilayers varies at most by a factor of 10 when pH is varied from near 1 to near 11. Two mechanisms have been proposed to account for this anomalous behavior: proton conductance related to contaminants of lipid bilayers, and proton translocation along transient hydrogen-bonded chains (tHBC) of associated water molecules in the membrane. The weight of evidence suggests that trace contaminants may contribute to proton conductance across planar lipid membranes at certain pH ranges, but cannot account for the anomalous proton flux in liposome systems. Two new results will be reported here which were designed to test the tHBC model. These include measurements of relative proton/potassium permeability in the gramicidin channel, and plots of proton flux against the magnitude of pH gradients. (1) The relative permeabilities of protons and potassium through the gramicidin channel, which contains a single strand of hydrogen-bonded water molecules, were found to differ by at least four orders of magnitude when measured at neutral pH ranges. This result demonstrates that a hydrogen-bonded chain of water molecules can provide substantial discrimination between protons and other cations. It was also possible to calculate that if approximately 7% of bilayer water was present in a transient configuration similar to that of the gramicidin channel, it could account for the measured proton flux. (2) The plot of proton conductance against pH gradient across liposome membranes was superlinear, a result that is consistent with one of three alternative tHBC models for proton conductance described by Nagle elsewhere in this volume.

  14. Permeation of Ionic Liquids through the skin

    Directory of Open Access Journals (Sweden)

    Ana Júlio

    2017-12-01

    Full Text Available Alternative forms of drug delivery such as delivery through the skin, have been developed to explore other routes. However, the incorporation of poorly soluble or partially insoluble drugs into these delivery systems represents a major problem. Ionic liquids (ILs may be incorporated in aqueous, oily or hydroalcoholic solutions and thus, may be used as excipients in drug delivery systems to increase/improve the topical and transdermal drug delivery. However, it is fundamental to consider the cytotoxicity of these salts and it is also crucial to evaluate if these compounds permeate through the skin. Herein, three imidazole-based ILs: [C2mim][Br], [C4mim][Br] and [C6mim][Br], were synthesized and each IL was incorporated within caffeine saturated solutions. Permeation studies of the active (caffeine in these solutions were performed to evaluate the amount of IL that permeated through the porcine ear skin in the presence of the active. To achieve this, gravimetric studies of the receptor compartment were performed. Results showed that the more lipophilic IL [C6mim][Br] presented the highest permeation through the skin. The permeation is dependent upon the size of the alkyl chain of the IL, and as more than 60% of the ILs permeate is it vital to consider the cytotoxicity of these salts when considering their incorporation in topical systems.

  15. Evaluation of whey, milk, and delactosed permeates as salt substitutes.

    Science.gov (United States)

    Smith, S T; Metzger, L; Drake, M A

    2016-11-01

    Whey and milk permeates are by-products of high-protein dairy powder manufacture. Previous work has shown that these permeates contribute to salty taste without contributing significantly to sodium content. The objective of this study was to explore the sensory characteristics and compositional analysis of permeates from different milk and whey streams and a low-sodium product application made from them. Skim milk, Cheddar, cottage, and Mozzarella cheese whey permeates were manufactured in triplicate, and delactosed whey permeate was obtained in triplicate. Composition (protein, fat, solids, minerals) was conducted on permeates. Organic acid composition was determined using HPLC. Volatile compounds were extracted from permeates by solid phase microextraction with gas chromatography-mass spectrometry. A trained sensory panel documented sensory attributes of permeates and cream of broccoli soups with and without salt or permeates followed by consumer acceptance testing (n=105) on the soups. Cottage cheese whey permeate contained a higher lactic acid content than other permeates, which has been shown to contribute to a higher salty taste. Cottage cheese whey permeate also contained potato or brothy and caramel flavors and sour and salty tastes, whereas delactosed whey permeate had high intensities of cardboard and beefy or brothy flavors and salty taste. Milk, Cheddar, and Mozzarella cheese whey permeates were characterized by sweet taste and cooked milky flavor. Permeates with higher cardboard flavor had higher levels of aldehydes. All permeates contributed to salty taste and to salty taste perception in soups; although the control soup with added salt was perceived as saltier and was preferred by consumers over permeate soups. Soup with permeate from cottage cheese was the least liked of all soups, likely due to its sour taste. All other permeate soups scored at parity for liking. These results demonstrate the potential for milk, whey, and delactosed permeates from

  16. [PALEOPATHOLOGY OF HUMAN REMAINS].

    Science.gov (United States)

    Minozzi, Simona; Fornaciari, Gino

    2015-01-01

    Many diseases induce alterations in the human skeleton, leaving traces of their presence in ancient remains. Paleopathological examination of human remains not only allows the study of the history and evolution of the disease, but also the reconstruction of health conditions in the past populations. This paper describes the most interesting diseases observed in skeletal samples from the Roman Imperial Age necropoles found in urban and suburban areas of Rome during archaeological excavations in the last decades. The diseases observed were grouped into the following categories: articular diseases, traumas, infections, metabolic or nutritional diseases, congenital diseases and tumours, and some examples are reported for each group. Although extensive epidemiological investigation in ancient skeletal records is impossible, the palaeopathological study allowed to highlight the spread of numerous illnesses, many of which can be related to the life and health conditions of the Roman population.

  17. Tritium permeation barriers for fusion technology

    International Nuclear Information System (INIS)

    Perujo, A.; Forcey, K.

    1994-01-01

    An important issue concerning the safety, feasibility and fueling (i.e., tritium breeding ratio and recovery from the breeding blanket) of a fusion reactor is the possible tritium leakages through the structural materials and in particular through those operating at high temperatures. The control of tritium permeation could be a critical factor in determining the viability of a future fusion power reactor. The formation of tritium permeation barriers to prevent the loss of tritium to the coolant by diffusion though the structural material seems to be the most practical method to minimize such losses. Many authors have discussed the formation of permeation barriers to reduce the leakage of hydrogen isotopes through proposed first wall and structural materials. In general, there are two routes for the formation of such a barrier, namely: the growth of oxide layers (e.g., Cr 2 O 3 , Al 2 O 3 , etc.) or the application of surface coatings. Non-metals are the most promising materials from the point of view of the formation of permeation barriers. Oxides such as Al 2 O 3 or Cr 2 O 3 or carbides such as SiC or TiC have been proposed. Amongst the metals only tungsten or gold are sufficiently less permeable than steel to warrant investigation as candidate materials for permeation barriers. It is of course possible to grow oxide layers on steel directly by heating in the atmosphere or under a variety of conditions (first route above). The direct oxidizing is normally done in an environment of open-quotes wet hydrogenclose quotes to promote the growth of chromia on, for example, nickel steels or ternary oxides on 316L to prevent corrosion. The application of surface layers (second route above), offers a greater range of materials for the formation of permeation barriers. In addition to reducing permeation, such layers should be adhesive, resistant to attack by corrosive breeder materials and should not crack during thermal cycling

  18. Feasibility of permeation grouting for constructing subsurface barriers

    International Nuclear Information System (INIS)

    Dwyer, B.P.

    1994-03-01

    The technical feasibility of emplacing a barrier beneath a waste site using directionally drilled boreholes and permeation grouting was investigated. The benefits of this emplacement system are: (1) Directionally drilled boreholes provide access beneath a waste site without disturbing the waste; (2) interim containment of contaminants allows time for the development of remediation options; (3) in the interim, the volume of waste remains fixed; (4) barriers may enhance the effectiveness of in situ remediation actions; and (5) barrier systems may provide permanent waste containment

  19. SPECT/spiral-CT hybrid imaging in unclear foci of increased bone metabolism: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Roemer, W.; Kuwert, T. [Nuklearmedizinische Klinik, Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany); Beckmann, M.W. [Frauenklinik, Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany); Forst, R. [Lehrstuhl fuer Orthopaedie mit Orthopaedischer Chirurgie, Friedrich-Alexander Univ. Erlangen/Nuernberg (Germany); Bautz, W. [Radiologisches Inst., Friedrich-Alexander-Univ. Erlangen/Nuernberg (Germany)

    2005-07-01

    In bone scintigraphy, the differentiation between degenerative processes and bone metastases is still difficult. Therefore, additional radiological studies are regularly needed after bone scintigraphy. The now introduced hybrid-cameras combining single-photon emission computed tomography (SPECT) and spiral-CT are unique in the sense that they offer the opportunity to correlate the functional information with morphology in one session. We herein present two patients in whom this technological setup allowed a definite diagnosis in scintigraphically unclear vertebral lesions. In a patient with breast cancer, hypermetabolic lesions were clearly correlated with osteolyses. In another patient with synovial carcinoma, spondylosis and spondylarthrosis caused focal tracer uptake in the lumbar spine. In addition to an improved diagnostic accuracy, SPECT/Spiral-CT will considerably abbreviate the diagnostic process. (orig.)

  20. SPECT/spiral-CT hybrid imaging in unclear foci of increased bone metabolism: a case report

    International Nuclear Information System (INIS)

    Roemer, W.; Kuwert, T.; Beckmann, M.W.; Forst, R.; Bautz, W.

    2005-01-01

    In bone scintigraphy, the differentiation between degenerative processes and bone metastases is still difficult. Therefore, additional radiological studies are regularly needed after bone scintigraphy. The now introduced hybrid-cameras combining single-photon emission computed tomography (SPECT) and spiral-CT are unique in the sense that they offer the opportunity to correlate the functional information with morphology in one session. We herein present two patients in whom this technological setup allowed a definite diagnosis in scintigraphically unclear vertebral lesions. In a patient with breast cancer, hypermetabolic lesions were clearly correlated with osteolyses. In another patient with synovial carcinoma, spondylosis and spondylarthrosis caused focal tracer uptake in the lumbar spine. In addition to an improved diagnostic accuracy, SPECT/Spiral-CT will considerably abbreviate the diagnostic process. (orig.)

  1. Permeation barrier for lightweight liquid hydrogen tanks

    Energy Technology Data Exchange (ETDEWEB)

    Schultheiss, D.

    2007-04-16

    For the future usage of hydrogen as an automotive fuel, its on-board storage is crucial. One approach is the storage of liquid hydrogen (LH2, 20 K) in double-walled, vacuum insulated tanks. The introduction of carbon fiber reinforced plastics (CFRP) as structural material enables a high potential of reducing the weight in comparison to the state-of-the-art stainless steel tanks. The generally high permeability of hydrogen through plastics, however, can lead to long-term degradation of the insulating vacuum. The derived objective of this dissertation was to find and apply an adequate permeation barrier (liner) on CFRP. The investigated liners were either foils adhered on CFRP specimens or coatings deposited on CFRP specimens. The coatings were produced by means of thermal spraying, metal plating or physical vapor deposition (PVD). The materials of the liners included Al, Au, Cu, Ni and Sn as well as stainless steel and diamond-like carbon. The produced liners were tested for their permeation behavior, thermal shock resistance and adherence to the CFRP substrate. Additionally, SEM micrographs were used to characterize and qualify the liners. The foils, although being a good permeation barrier, adhered weakly to the substrate. Furthermore, leak-free joining of foil segments is a challenge still to be solved. The metal plating liners exhibited the best properties. For instance, no permeation could be detected through a 50 {mu}m thick Cu coating within the accuracy of the measuring apparatus. This corresponds to a reduction of the permeation gas flow by more than factor 7400 compared to uncoated CFRP. In addition, the metal platings revealed a high adherence and thermal shock resistance. The coatings produced by means of thermal spraying and PVD did not show a sufficient permeation barrier effect. After having investigated the specimens, a 170 liter CFRP tank was fully coated with 50 {mu}m Cu by means of metal plating. (orig.)

  2. Permeation of Comite through protective gloves.

    Science.gov (United States)

    Zainal, Hanaa; Que Hee, Shane S

    2006-09-01

    The goal of the study was to assess how protective disposable (Safeskin) and chemical protective (Sol-Vex) nitrile gloves were against Comite emulsifiable concentrate formulation containing propargite (PROP) as active pesticidal ingredient, because there were no explicit recommendations for the gloves that should be worn for hand protection. The glove material was exposed in ASTM-type I-PTC-600 permeation cells at 30.0+/-0.5 degrees C, and gas chromatography-mass spectrometry used for PROP analysis. Aqueous solutions of Comite at 40.4 mg/mL permeated both Safeskin and Sol-Vex nitrile by 8h. Safeskin showed a mean PROP mass permeated of 176+/-27 microg after 8h compared with a mean mass permeated for Sol-Vex of 3.17+/-4.08 microg. Thus, Sol-Vex was about 56 times more protective than Safeskin for an 8-h exposure. However, the kinetics of the permeation revealed that Safeskin can be worn for at least 200 min before disposal. When undiluted Comite challenged both types of nitrile, much faster permeation was observed. Safeskin gloves showed two steady state periods. The first had lag times (t(l)) values of about 1h, although normalized breakthrough times (t(b)) were gloves exposed continuously to undiluted Comite permeated above the normalized breakthrough threshold beyond 2.7h. A risk assessment revealed that the PROP skin permeation rate of 7.1 ng cm(-2)h(-1) was much slower than the first steady state Safeskin glove P(s) of 62,000 ng cm(-2)h(-1). Infrared analysis showed that the glove surfaces were not degraded by the Comite challenge. The chemically protective Sol-Vex gloves protected adequately against undiluted formulation for about 2.7h, whereas they provided protection for nearly 8h when the formulation was diluted with water to the highest concentration for field application. In contrast, the disposable Safeskin gloves did not protect at all for the undiluted formulation, but did for 200 min when the formulation was diluted with water to the highest

  3. In-site coatings to reduce H and Tr permeation

    International Nuclear Information System (INIS)

    Stoever, D.; Buchkremer, H.P.; Hecker, R.; Jonas, H.; Schaefer, J.; Zink, U.; Forsyth, N.; Thiele, W.

    1982-01-01

    The main goal of this project is the development of protective coatings to reduce or prevent Tr and H permeation through the heat exchanger walls of HTR components. The tasks of the project are: Measurement of the permeation inhibition efficiency of oxidic coatings on the high-temperature- resistant heat exchanger walls; establishing the parameters influencing permeation by variation of the process gas and steam parameters, temperature and mechanical stress; characterisation of coatings and correlation of coating characteristics with permeation measurements; investigation of permeation and corrosion mechanisms; quantitative description of H and Tr permeation by means of mathematical/physical models. (orig./IHOE) [de

  4. «Unclear Enemy»: Why the Guerrilla War in France in 1814 Failed

    Directory of Open Access Journals (Sweden)

    Nikolay A. Mogilevskiy

    2015-01-01

    Full Text Available Abstract: Author of the article analyzes the reasons of the fail of Napoleon’s attempts to set the guerrilla war in France during the campaign of 1814. While the forces of anti-Napoleonic coalition were standing near the border of France, Napoleon did his best to recruit his new army. But the human resources of France were exhausted, and that’s why Napoleon decided to set the guerrillia. But all his proclamations and even his orders were disobeyed - French people were too tired of incessant war, and Napoleon again decided to gain his goals on the battlefield. Besides author shows great efforts of Russian headquarters to avoid the guerrilla war. Alexander I and his allies in theirs proclamations declared that they were fighting only with Napoleon, but not with the French nation. That tactic gave a brilliant result and helped to avoid the patriotic uplift in France in 1814. In this propagandistic war Napoleon was defeated and that cost him his throne. The reasons of Napoleon’s fail, firstly, was the unclear image of the enemy. French emperor didn’t manage to unite French nation against the rival. On the contrary the French Emperor, his enemies managed (in their proclamations and personal conversations to persuade the French people, that the allies had one enemy - the Emperor Napoleon, not the French nation, and the ultimate goal of war - to set peace on the European continent. That was exactly how the allies did set the disunity between Napoleon and his people. Ultimately, the combination of these factors was the reason that a guerrilla war never broke out in France.

  5. LIBRETTO-3: modelling tritium extraction/permeation and evaluation of permeation barriers under irradiation

    International Nuclear Information System (INIS)

    Sedano, L.A.; Fuetterer, M.A.; Viola, R.; Dies, X.

    1996-01-01

    Permeation barriers are required in order to limit the size and cost of the detritiation plants for future fusion reactor blankets of the water-cooled Pb-17Li type. The LIBRETTO irradiations were performed to evaluate the efficiency of permeation barriers under high flux reactor (HFR) conditions. Tritium extraction and permeation characteristics from Pb-17Li under variable temperatures 553-723 K, H 2 doping (0-1 vol%) and purge gas flow rates 20-100 scc/min were tested in LIBRETTO-3. An external TiC coating, an internal (TiC+Al 2 O 3 ), both produced by chemical vapour deposition (CVD), and an internal Al 2 O 3 produced by pack cementation (PC) on AISI 316L steel were tested as permeation barriers. The release mechanisms, experimental uncertainties and method for permeation barriers qualification are presented. As a result permeation reduction factors (PRF) at 0.1 dpa of 17 and 34 were obtained for the CVD-Al 2 O 3 at 498 K and for the PC-Al 2 O 3 at 508 K, respectively. These values were confirmed by a residence time analysis and are higher than in a preliminary analysis. (orig.)

  6. Effect of Permeation Enhancers on the Release Behavior and ...

    African Journals Online (AJOL)

    Purpose: The aim of this research work was to formulate, characterize and evaluate the in vitro permeation behavior of tramadol lotion containing propylene glycol (PG) and polyethylene glycol (PEG) as permeation enhancers. Methods: The permeation experiments were conducted in vitro using full thickness rabbit skin in ...

  7. Skin permeation and antioxidant efficacy of topically applied resveratrol.

    Science.gov (United States)

    Alonso, Cristina; Martí, M; Barba, C; Carrer, V; Rubio, L; Coderch, L

    2017-08-01

    The permeation of resveratrol was assessed by in vitro and in vivo experiments 24 h after topical administration. The in vitro profile of resveratrol was assessed by Raman spectroscopy. Human skin permeation was analysed in vivo by the tape stripping method with the progressive removal of the stratum corneum layers using adhesive tape strips. Moreover, the free radical scavenging activity of resveratrol after its topical application was determined using the DPPH assay. The Raman spectra indicated that the topically applied resveratrol penetrates deep into the skin. The results showed high amounts of resveratrol in the different stratum corneum layers close to the surface and a constant lower amount in the upper layers of the viable epidermis. The concentration of resveratrol present in the outermost stratum corneum layers was obtained by tape stripping after in vivo application. The results demonstrated that resveratrol mainly remained in the human stratum corneum layers. After topical application, resveratrol maintained its antiradical activity. The antioxidant efficacy of the compound was higher in the inner layers of the stratum corneum. As these results have demonstrated, topically applied resveratrol reinforces the antioxidant system of the stratum corneum and provides an efficient means of increasing the tissue levels of antioxidants in the human epidermis.

  8. Improved permeation barriers for tritiated waste packaging

    International Nuclear Information System (INIS)

    Vassallo, G.; Van Den Bergh, R.; Forcey, K.S.; Perujo, A.

    1994-01-01

    High-density polyethylene (HDPE) is extensively used as flexible bagging or packaging for soft tritiated waste in the tritium community because of its low permeability to the more radiotoxic form of tritium, i.e., tritiated water (HTO). However, HDPE does not represent a perfect barrier to HTO nor does it effectively hinder the permeation of elemental tritium, i.e, HT. This latter drawback is particularly important considering that the elemental form may readily convert to HTO outside of the waste package. The possible use of a multilayer film as packing material for the conditioning of tritiated waste is assessed, and its capability to hinder the permeation of elemental tritium is measured and compared with that of bare HDPE. The material investigated is readily available from the food industry. 5 refs., 1 tab

  9. Modeling and experiments on tritium permeation in fusion reactor blankets

    Science.gov (United States)

    Holland, D. F.; Longhurst, G. R.

    The determination of tritium loss from helium-cooled fusion breeding blankets are discussed. The issues are: (1) applicability of present models to permeation at low tritium pressures; (2) effectiveness of oxide layers in reducing permeation; (3) effectiveness of hydrogen addition as a means to lower tritium permeation; and (4) effectiveness of conversion to tritiated water and subsequent trapping to reduce permeation. Theoretical models applicable to these issues are discussed, and results of experiments in two areas are presented; permeation of mixtures of hydrogen isotopes and conversion to tritiated water.

  10. Modeling and experiments on tritium permeation in fusion reactor blankets

    International Nuclear Information System (INIS)

    Holland, D.F.; Longhurst, G.R.

    1985-01-01

    Issues are discussed that are critical in determining tritium loss from helium-cooled fusion breeding blankets. These issues are: (a) applicability of present models to permeation at low tritium pressures, (b) effectiveness of oxide layers in reducing permeation, (c) effectiveness of hydrogen addition as a means to lower tritium permeation, and (d) effectiveness of conversion to tritiated water and subsequent trapping as a means to reduce permeation. The paper discusses theoretical models applicable to these issues, and presents results of experiments in two areas: permeation of mixtures of hydrogen isotopes and conversion to tritiated water

  11. Phosphate application to firing range soils for Pb immobilization: The unclear role of phosphate

    International Nuclear Information System (INIS)

    Chrysochoou, Maria; Dermatas, Dimitris; Grubb, Dennis G.

    2007-01-01

    Phosphate treatment has emerged as a widely accepted approach to immobilize Pb in contaminated soils and waste media, relying on the formation of the highly insoluble mineral pyromorphite as solubility-controlling phase for Pb. As such, phosphate treatment has been proposed as a Best Management Practice (BMP) for firing ranges where Pb occurs in its metallic forms and several other phases (carbonates, oxides). While pyromorphite thermodynamically has the potential to control Pb solubility at low levels, its formation is kinetically controlled by pH, the solubility of the phosphate source, and the solubility of Pb species. Treatability studies have shown that excess quantities of soluble and acidic phosphate sources, such as phosphoric acid, are necessary for successful in situ treatment. Even under these conditions, Extended X-ray Absorption Fine Structure (EXAFS), the only reliable method to identify and quantify Pb speciation, showed that Pb conversion to pyromorphite in in situ treated soils was less than 45% after 32 months. Furthermore, the use of lime (CaO) to restore soil pH in acidified soil treatments inhibited further conversion. Additionally, phosphate treatment is known to reduce bioavailability through pyromorphite formation in the intestinal tract, and the phytoaccumulation of Pb; both desirable effects for Pb-impacted areas. Given the costs of phosphate treatment, the use of biogenic phosphate sources, such as bone meal, may be a more environmentally sustainable approach toward this end. In the many studies focusing on phosphate treatment, the attendant P leaching and eutrophication have been largely overlooked, along with other issues such as the enhanced leaching of oxyanionic contaminants, such as Se, As and W. The success and sustainability of applying phosphate as a BMP in firing range soils therefore remain questionable

  12. Enzymatic hydrolysis of lactose of whey permeate

    Directory of Open Access Journals (Sweden)

    Karina Nascimento de Almeida

    2015-09-01

    Full Text Available The whey permeate is the residual of the concentration process of the whey proteins by ultrafiltration method. It contains important nutrients such as lactose, minerals and some proteins and lipids. It is without an ending industrial waste that causes serious damage to the environment. For its full use the lactose must be hydrolyzed to enable its consumption by intolerant people. The enzymatic hydrolysis by lactase (β-galactosidase of Kluyveromyces lactis yeast is a safe method that does not compromise the integrity of other nutrients, enabling further use of the permeate as a raw material. This study aimed to perform tests of enzymatic hydrolysis of lactose in whey permeate formulations in a concentration of 0.2%, 0.7% and 1% at 30, 60 and 90 minutes with pH 6.3 medium and 37 °C. The reactions were monitored by high performance liquid chromatography which showed that the enzyme concentration of 0.7% at time 30 minutes formulations became safe for consumption by lactose intolerant people, according to minimum levels established by law.

  13. Incidence of DWI-positive stroke in patients with vertigo of unclear etiology, preliminary results.

    Science.gov (United States)

    Leker, Ronen R; Hur, Tamir Ben; Gomori, John M; Paniri, R; Eichel, Roni; Cohen, Jose E

    2013-03-01

    Acute vertigo may be secondary to stroke or to non-ischemic causes. Accurate identification of vertigo secondary to ischemia may lead to appropriate timely intervention that can minimize stroke-related damage and can help in tailoring the most appropriate individual therapy for affected patients. Diffusion weighted MRI (DWI) is very accurate for diagnosing stroke and we therefore aimed to test whether it can aid in making a correct diagnosis of vertigo secondary to stroke. All patients presenting with vertigo in which the diagnosis of stroke was considered underwent DWI only MRI. Data regarding the symptoms and neurological deficits, vascular risk factors, imaging findings, and outcomes was accrued. Patients with stroke on DWI were compared with those without ischemia. Between June 2010 and August 2011, 28 patients fulfilling the entry criteria were identified with a mean age of 62·2±12·8 (60% male). The final diagnosis was stroke in 11 patients (39%). Patients with stroke did not differ from those without stroke in their risk factor profile. However, patients with stroke more often tended to present with vertigo accompanied by other neurological symptoms (73% versus 12% respectively, P = 0·001). After adjusting for age and the presence of diabetes, the presence of multiple symptoms remained the only variable that was associated with a positive DWI scan (odds ratio: 30: 95% confidence interval: 2·6-349). Most patients with stroke had very mild strokes with a median admission NIHSS score of 3 and DWI lesion volumes >2 cm were found in only three patients. Most stroke patients made a good recovery (modified Rankin score ≤2 in seven of nine patients with 90 day data). The most common diagnosis in patients without stroke was of vertigo of peripheral origin (14/17). DWI only MRI can be used to rapidly screen patients presenting with vertigo and suspected vertebrobasilar stroke. The occurrence of vertigo in combination with other focal neurological symptoms may

  14. Flibe-D2 Permeation Experiment and Analysis

    International Nuclear Information System (INIS)

    Fukada, S.; Anderl, R.A.; Pawelko, R.J.; Smolik, G.R.; Schuetz, S.T.; O'Brien, J.E.; Nishimura, H.; Hatano, Y.; Terai, T.; Petti, D.A.; Sze, D.-K.; Tanaka, S.

    2003-01-01

    Experiment of D 2 permeation through Ni facing with purified Flibe is being carried out under the Japan-US joint research project (JUPITER-II). The experiment is proceeding in the following phases; (i) fabrication and assembly of a dual-probe permeation apparatus, (ii) a single-probe Ni/D 2 permeation experiment without Flibe, (iii) a dual-probe Ni/D 2 permeation experiment without Flibe, (iv) Flibe chemical purification by HF/H 2 gas bubbling, (v) physical purification by Flibe transport through a porous Ni filter, (vi) Ni/Flibe/D 2 permeation experiment, and (vii) Ni/Flibe/HT permeation experiment. The present paper describes results of the single and dual Ni/D 2 permeation experiments in detail

  15. Atomic scale simulation of H2O2 permeation through aquaporin: toward the understanding of plasma cancer treatment

    Science.gov (United States)

    Yusupov, Maksudbek; Yan, Dayun; Cordeiro, Rodrigo M.; Bogaerts, Annemie

    2018-03-01

    Experiments have demonstrated the potential selective anticancer capacity of cold atmospheric plasmas (CAPs), but the underlying mechanisms remain unclear. Using computer simulations, we try to shed light on the mechanism of selectivity, based on aquaporins (AQPs), i.e. transmembrane protein channels transferring external H2O2 and other reactive oxygen species, created e.g. by CAPs, to the cell interior. Specifically, we perform molecular dynamics simulations for the permeation of H2O2 through AQP1 (one of the members of the AQP family) and the palmitoyl-oleoyl-phosphatidylcholine (POPC) phospholipid bilayer (PLB). The free energy barrier of H2O2 across AQP1 is lower than for the POPC PLB, while the permeability coefficient, calculated using the free energy and diffusion rate profiles, is two orders of magnitude higher. This indicates that the delivery of H2O2 into the cell interior should be through AQP. Our study gives a better insight into the role of AQPs in the selectivity of CAPs for treating cancer cells.

  16. Governing Unclear Lines

    NARCIS (Netherlands)

    Justin, Peter Hakim; Vries, de Lotje

    2017-01-01

    South Sudan’s administrative boundaries stem from the colonial period. Since it gained independence in 2011, subsequent rounds of reshuffling of the political system, internal borders, and power relations have been a source of confusion, elite manipulation, and conflict throughout the country. This

  17. Microstructural Study on Oxygen Permeated Arc Beads

    Directory of Open Access Journals (Sweden)

    Kuan-Heng Liu

    2015-01-01

    Full Text Available We simulated short circuit of loaded copper wire at ambient atmosphere and successfully identified various phases of the arc bead. A cuprous oxide flake was formed on the surface of the arc bead in the rapid solidification process, and there were two microstructural constituents, namely, Cu-κ eutectic structure and solutal dendrites. Due to the arc bead formed at atmosphere during the local equilibrium solidification process, the phase of arc bead has segregated to the cuprous oxide flake, Cu-κ eutectic, and Cu phase solutal dendrites, which are the fingerprints of the arc bead permeated by oxygen.

  18. Hydrogen isotope permeation in elastomeric materials

    International Nuclear Information System (INIS)

    Steinmeyer, R.H.; Braun, J.D.

    1976-01-01

    The permeabilities of elastomeric and polymeric materials to hydrogen isotopes were measured at room temperature. The technique for measuring permeation rates is based on the following constant-volume method: a fixed pressure of gas is applied to one side of the specimen to be studied and the permeability constant is determined from the observed rate of pressure increase in an initially evacuated volume on the other side of the specimen. Permeability constants for hydrogen, deuterium, and tritium were measured for Mylar, Teflon, Kapton, Saran, Buna-N, and latex rubber. Results were compared with literature values for hydrogen and deuterium where available and showed excellent agreement

  19. Organic fluid permeation through fluoropolymer membranes

    Science.gov (United States)

    Nemser, Stuart M.; Kosaraju, Praveen; Bowser, John

    2015-07-14

    Separation of the components of liquid mixtures is achieved by contacting a liquid mixture with a nonporous membrane having a fluoropolymer selectively permeable layer and imposing a pressure gradient across the membrane from feed side to permeate side. Unusually high transmembrane flux is obtained when the membrane is subjected to one or more process conditions prior to separation. These include (a) leaving some residual amount of membrane casting solvent in the membrane, and (b) contacting the membrane with a component of the mixture to be separated for a duration effective to saturate the membrane with the component.

  20. Tritium permeation losses in HYLIFE-II heat exchanger tubes

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Dolan, T.J.

    1990-01-01

    Tritium permeation through the intermediate heat exchanger of the HYLIFE-II inertial fusion design concept is evaluated for routine operating conditions. The permeation process is modelled using the Lewis analogy combined with surface recombination. It is demonstrated that at very low driving potentials, permeation becomes proportional to the first power of the driving potential. The model predicts that under anticipated conditions the primary cooling loop will pass about 6% of the tritium entering it to the intermediate coolant. Possible approached to reducing tritium permeation are explored. Permeation is limited by turbulent diffusion transport through the molten salt. Hence, surface barriers with impendance factors typical of present technology can do very little to reduce permeation. Low Flibe viscosity is desirable. An efficient tritium removal system operating on the Flibe before it gets to the intermediate heat exchanger is required. Needs for further research are highlighted. 9 refs., 2 figs., 1 tab

  1. Protection efficacy of gloves against components of the solvent in a sprayed isocyanate coating utilizing a reciprocating permeation panel.

    Science.gov (United States)

    Ceballos, Diana M; Reeb-Whitaker, Carolyn; Sasakura, Miyoko; Dills, Russell; Yost, Michael G

    2015-04-01

    Determine protection effectiveness of 5-mil natural rubber latex (0.13-mm), 5-mil nitrile rubber (0.13-mm), and 13-mil butyl rubber (0.33-mm) glove materials against solvents present in a commonly used automotive clear coat formulation using a novel permeation panel. The latex and nitrile gloves were the type commonly used by local autobody spray painters. Glove materials were tested by spraying an automotive clear coat onto an automated reciprocating permeation panel (permeation panel II). Temperature, relative humidity, and spray conditions were controlled to optimize clear coat loading homogeneity as evaluated by gravimetric analysis. Solvent permeation was measured using charcoal cloth analyzed by the National Institute for Occupational Safety and Health 1501 method. Natural rubber latex allowed 3-5 times the permeation of solvents relative to nitrile rubber for all 10 solvents evaluated: ethyl benzene, 2-heptanone, 1-methoxy-2-propyl acetate, o-xylene, m-xylene, p-xylene, n-butyl acetate, methyl isobutyl ketone, petroleum distillates, and toluene. There is a distinct behavior in solvent permeation before and after the coating dry time. Solvent permeation increased steadily before coating dry time and remained fairly constant after coating dry time. Butyl was not permeated by any of the solvents under the conditions tested. Commonly used 5-mil thick (0.13-mm) latex and nitrile gloves were ineffective barriers to solvents found in a commonly used clear coat formulation. Conversely, 13-mil (0.33-mm) butyl gloves were found to be protective against all solvents in the clear coat formulation. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  2. Development of a Contact Permeation Test Fixture and Method

    Science.gov (United States)

    2013-04-01

    Permeation and Analytical Solutions Team Quality System documentation and the guidance found in the ISO 17025 standard. All permeation and...annular ring (left) and no pressure (right). 2.2.4 Quality Controls Analytical permeation testing was conducted in accordance with ISO 17025 quality...internal standard. This mixture was vortexed for 20–30 s then centrifuged at 15,000 rpm for 5 min in a Micromax microcentrifuge (Thermo IEC ; Needham

  3. In situ measurement of tritium permeation through stainless steel

    Science.gov (United States)

    Luscher, Walter G.; Senor, David J.; Clayton, Kevin K.; Longhurst, Glen R.

    2013-06-01

    The TMIST-2 irradiation experiment was conducted in the Advanced Test Reactor at Idaho National Laboratory to evaluate tritium permeation through Type 316 stainless steel (316 SS). The interior of a 316 SS seamless tube specimen was exposed to a 4He carrier gas mixed with a specified quantity of tritium (T2) to yield partial pressures of 0.1, 5, and 50 Pa at 292 °C and 330 °C. In situ tritium permeation measurements were made by passing a He-Ne sweep gas over the outer surface of the specimen to carry the permeated tritium to a bubbler column for liquid scintillation counting. Results from in situ permeation measurements were compared with predictions based on an ex-reactor permeation correlation in the literature. In situ permeation data were also used to derive an in-reactor permeation correlation as a function of temperature and pressure over the ranges considered in this study. In addition, the triton recoil contribution to tritium permeation, which results from the transmutation of 3He to T, was also evaluated by introducing a 4He carrier gas mixed with 3He at a partial pressure of 1013 Pa at 330 °C. Less than 3% of the tritium resulting from 3He transmutation contributed to tritium permeation.

  4. Separation of aromatics by vapor permeation through solvent swollen membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ito, A.; Adachi, K.; Feng, Y. [Niigata University, Niigata (Japan)

    1995-12-20

    A vapor permeation process for aromatics separation from a hydrocarbon mixture was studied by means of the simultaneous permeation of dimethylsulfoxide vapor as an agent for membrane swelling and preferential permeation of aromatics. The separation performance of the process was demonstrated by a polyvinylalcohol membrane for mixed vapors of benzene/cyclohexane, xylene/octane and a model gasoline. The aromatic vapors preferentially permeated from these mixed vapor feeds. The separation factor was over 10. The separation mechanism of the process mainly depends on the relative salability of the vapors between aromatics and other hydrocarbons in dimethylsulfoxide. 14 refs., 9 figs., 1 tab.

  5. Hydrogen permeation resistant layers for liquid metal reactors

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1980-03-01

    Reviewing the literature in the tritium diffusion field one can readily see a wide divergence in results for both the response of permeation rate to pressure, and the effect of oxide layers on total permeation rates. The basic mechanism of protective oxide layers is discussed. Two coatings which are less hydrogen permeable than the best naturally occurring oxide are described. The work described is part of an HEDL-ANL cooperative research program on Tritium Permeation in Liquid Metal Cooled Reactors. This includes permeation work on hydrogen, deuterium, and tritium with the hydrogen-deuterium research leading to the developments presented

  6. Modelling the effect of mixture components on permeation through skin.

    Science.gov (United States)

    Ghafourian, T; Samaras, E G; Brooks, J D; Riviere, J E

    2010-10-15

    A vehicle influences the concentration of penetrant within the membrane, affecting its diffusivity in the skin and rate of transport. Despite the huge amount of effort made for the understanding and modelling of the skin absorption of chemicals, a reliable estimation of the skin penetration potential from formulations remains a challenging objective. In this investigation, quantitative structure-activity relationship (QSAR) was employed to relate the skin permeation of compounds to the chemical properties of the mixture ingredients and the molecular structures of the penetrants. The skin permeability dataset consisted of permeability coefficients of 12 different penetrants each blended in 24 different solvent mixtures measured from finite-dose diffusion cell studies using porcine skin. Stepwise regression analysis resulted in a QSAR employing two penetrant descriptors and one solvent property. The penetrant descriptors were octanol/water partition coefficient, logP and the ninth order path molecular connectivity index, and the solvent property was the difference between boiling and melting points. The negative relationship between skin permeability coefficient and logP was attributed to the fact that most of the drugs in this particular dataset are extremely lipophilic in comparison with the compounds in the common skin permeability datasets used in QSAR. The findings show that compounds formulated in vehicles with small boiling and melting point gaps will be expected to have higher permeation through skin. The QSAR was validated internally, using a leave-many-out procedure, giving a mean absolute error of 0.396. The chemical space of the dataset was compared with that of the known skin permeability datasets and gaps were identified for future skin permeability measurements. Copyright 2010 Elsevier B.V. All rights reserved.

  7. In situ measurement of tritium permeation through stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Luscher, Walter G., E-mail: walter.luscher@pnnl.gov [Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99352 (United States); Senor, David J., E-mail: david.senor@pnnl.gov [Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99352 (United States); Clayton, Kevin K., E-mail: kevin.clayton@inl.gov [Idaho National Laboratory, 2525 Fremont Ave., Idaho Falls, ID 83415 (United States); Longhurst, Glen R., E-mail: glenlonghurst@suu.edu [Idaho National Laboratory, 2525 Fremont Ave., Idaho Falls, ID 83415 (United States)

    2013-06-15

    Highlights: ► In situ tritium permeation measurements collected over broad pressure range. ► Test conditions relevant to 316 SS in commercial light water reactors. ► Comparisons between in- and ex-reactor measurements provided. ► Correlation between tritium permeation, temperature, and pressure developed. -- Abstract: The TMIST-2 irradiation experiment was conducted in the Advanced Test Reactor at Idaho National Laboratory to evaluate tritium permeation through Type 316 stainless steel (316 SS). The interior of a 316 SS seamless tube specimen was exposed to a {sup 4}He carrier gas mixed with a specified quantity of tritium (T{sub 2}) to yield partial pressures of 0.1, 5, and 50 Pa at 292 °C and 330 °C. In situ tritium permeation measurements were made by passing a He–Ne sweep gas over the outer surface of the specimen to carry the permeated tritium to a bubbler column for liquid scintillation counting. Results from in situ permeation measurements were compared with predictions based on an ex-reactor permeation correlation in the literature. In situ permeation data were also used to derive an in-reactor permeation correlation as a function of temperature and pressure over the ranges considered in this study. In addition, the triton recoil contribution to tritium permeation, which results from the transmutation of {sup 3}He to T, was also evaluated by introducing a {sup 4}He carrier gas mixed with {sup 3}He at a partial pressure of 1013 Pa at 330 °C. Less than 3% of the tritium resulting from {sup 3}He transmutation contributed to tritium permeation.

  8. Permeation of Light Gases through Hexagonal Ice

    Directory of Open Access Journals (Sweden)

    Luis Gales

    2012-09-01

    Full Text Available Gas separation using porous solids have attracted great attention due to their energetic applications. There is an enormous economic and environmental interest in the development of improved technologies for relevant processes, such as H2 production, CO2 separation or O2 and N2 purification from air. New materials are needed for achieving major improvements. Crystalline materials, displaying unidirectional and single-sized pores, preferentially with low pore tortuosity and high pore density, are promising candidates for membrane synthesis. Herein, we study hexagonal ice crystals as an example of this class of materials. By slowly growing ice crystals inside capillary tubes we were able to measure the permeation of several gas species through ice crystals and investigate its relation with both the size of the guest molecules and temperature of the crystal.

  9. Electrical insulator assembly with oxygen permeation barrier

    Science.gov (United States)

    Van Der Beck, Roland R.; Bond, James A.

    1994-01-01

    A high-voltage electrical insulator (21) for electrically insulating a thermoelectric module (17) in a spacecraft from a niobium-1% zirconium alloy wall (11) of a heat exchanger (13) filled with liquid lithium (16) while providing good thermal conductivity between the heat exchanger and the thermoelectric module. The insulator (21) has a single crystal alumina layer (SxAl.sub.2 O.sub.3, sapphire) with a niobium foil layer (32) bonded thereto on the surface of the alumina crystal (26) facing the heat exchanger wall (11), and a molybdenum layer (31) bonded to the niobium layer (32) to act as an oxygen permeation barrier to preclude the oxygen depleting effects of the lithium from causing undesirable niobium-aluminum intermetallic layers near the alumina-niobium interface.

  10. Tritium permeation model for plasma facing components

    Science.gov (United States)

    Longhurst, G. R.

    1992-12-01

    This report documents the development of a simplified one-dimensional tritium permeation and retention model. The model makes use of the same physical mechanisms as more sophisticated, time-transient codes such as implantation, recombination, diffusion, trapping and thermal gradient effects. It takes advantage of a number of simplifications and approximations to solve the steady-state problem and then provides interpolating functions to make estimates of intermediate states based on the steady-state solution. The model is developed for solution using commercial spread-sheet software such as Lotus 123. Comparison calculations are provided with the verified and validated TMAP4 transient code with good agreement. Results of calculations for the ITER CDA diverter are also included.

  11. Tritium permeation model for plasma facing components

    International Nuclear Information System (INIS)

    Longhurst, G.R.

    1992-12-01

    This report documents the development of a simplified one-dimensional tritium permeation and retention model. The model makes use of the same physical mechanisms as more sophisticated, time-transient codes such as implantation, recombination, diffusion, trapping and thermal gradient effects. It takes advantage of a number of simplifications and approximations to solve the steady-state problem and then provides interpolating functions to make estimates of intermediate states based on the steady-state solution. The model is developed for solution using commercial spread-sheet software such as Lotus 123. Comparison calculations are provided with the verified and validated TMAP4 transient code with good agreement. Results of calculations for the ITER CDA diverter are also included

  12. Permeation of Telone EC through protective gloves.

    Science.gov (United States)

    Zainal, Hanaa; Que Hee, Shane S

    2005-09-30

    Telone is a potent fumigant that is based on the chlorinated unsaturated hydrocarbon, 1,3-dichloropropene (1,3-DCP). It is often applied without dilution and so poses severe inhalation and air pollution threats. Urinary metabolites of 1,3-DCP have been detected after Telone skin exposure, so that preventing dermal exposure is also important. The objective of the study was to assess if nitrile and multi-layer ("laminated") gloves provide adequate protection against Telone EC formulation. To accomplish this, disposable (Safeskin) and chemically resistant (Sol-Vex) nitrile and laminated (Barrier mark and Silver Shield) glove materials were challenged by Telone EC with hexane liquid collection in an ASTM-type I-PTC-600 permeation cell. Analyses of cis- and trans-1,3-DCP in the collection fluid at specified times were performed on a moderately polar capillary column by gas chromatography-electron capture detection. Telone EC caused microholes in both nitrile materials, though the chemically protective material was degraded slower than the disposable nitrile. The laminated gloves offered limited protection. Silver Shield protected best because 1.5-2.3 mg 1,3-DCP permeated by 8 h relative to 2.5-7.6 mg for Barrier, implying about 2.5 times more protection for 8 h. Even for Silver Shield, the extent of protection was inadequate as illustrated by a risk assessment of the skin exposure situation. The normalized breakthrough times for both types of laminated gloves varied between 27 and 60 min. It is recommended that Viton gloves still be worn for protection.

  13. A study on reverse osmosis permeating treatment for yarn dyeing ...

    African Journals Online (AJOL)

    This paper presents a fuzzy linear regression model for estimation of reverse osmosis permeating parameters conditions. The proposed model can effectively take on non-crisp, fuzzy and crisp data. This study model used for estimation of reverse osmosis permeating parameters data from Tirupur examines the variables that ...

  14. Effect of Nutrient Formulations on Permeation of Proteins and Lipids ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of nutrient formulations on the permeation of proteins and lipids through porcine intestine in vitro. Method: In vitro permeation studies of proteins and lipids of two peptide-based formulations, composed of various compounds and sources of hydrolyzed protein was carried out, and compared ...

  15. An unheated permeation device for calibrating atmospheric VOC measurements

    Directory of Open Access Journals (Sweden)

    J. Brito

    2011-10-01

    Full Text Available The development of an unpowered permeation device for continuous calibration of in-situ instruments measuring atmospheric volatile organic compounds (VOCs is described. Being lightweight and compact, and containing only negligible amounts of chemicals, the device is especially suited for field use such as on board aircraft. Its speciality is to maintain the permeation process in thermal equilibrium, so that the instantaneous permeation rate can be ascribed to a simple temperature measurement. This equilibrium state is maintained by a combination of three features: (i a thin PTFE membrane as permeation medium which guarantees short stabilization times, (ii a water bath as heat buffer, and (iii a vacuum-panel based insulation, in which features (ii and (iii minimize temperature drifts to ~30 mK h−1 per Kelvin temperature difference to the environment. The respective uncertainty of the permeation rate due to thermal non-equilibrium is kept below 1%. An extensive theory part details the major permeation processes of gases through porous polymers, being Fick's diffusion, Knudsen flow, and viscous flow. Both the measured stabilization time and the measured temperature dependence of the permeation rate independently indicate that the permeation can be described by a viscous flow model, where diffusion of the gas molecules in large pores (having a diameter of >0.05 μm dominates.

  16. Implantation driven permeation behavior of deuterium through pure tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hirofumi E-mail: nakamura@tpl.tokai.jaeri.go.jp; Hayashi, Takumi; Nishi, Masataka; Arita, Makoto; Okuno, Kenji

    2001-09-01

    Implantation driven permeation behavior of deuterium through pure tungsten has been investigated to estimate the amount of tritium permeation through its barrier in a thermo-nuclear fusion device. The permeation experiments were performed on pure tungsten foil of 25 {mu}m thickness under conditions of incident flux of 1.9x10{sup 18}-1.1x10{sup 19} D{sup +}/m{sup 2}s, incident ion energy of 200-2000 eV, and specimen temperature of 512-660 K. As a result of this steady-state permeation experiment, the rate-determining process of deuterium permeation was found to be controlled by diffusion at both implanted and permeated sides. On the other hand, transient permeation was strongly affected by trap effect in the specimen. Simulation analysis using TMAP code on transient permeation behavior indicates the existence of a trap site with a trap energy of nearly 1eV and with a trap density of over several ten's ppm in tungsten.

  17. Implantation driven permeation behavior of deuterium through pure tungsten

    International Nuclear Information System (INIS)

    Nakamura, Hirofumi; Hayashi, Takumi; Nishi, Masataka; Arita, Makoto; Okuno, Kenji

    2001-01-01

    Implantation driven permeation behavior of deuterium through pure tungsten has been investigated to estimate the amount of tritium permeation through its barrier in a thermo-nuclear fusion device. The permeation experiments were performed on pure tungsten foil of 25 μm thickness under conditions of incident flux of 1.9x10 18 -1.1x10 19 D + /m 2 s, incident ion energy of 200-2000 eV, and specimen temperature of 512-660 K. As a result of this steady-state permeation experiment, the rate-determining process of deuterium permeation was found to be controlled by diffusion at both implanted and permeated sides. On the other hand, transient permeation was strongly affected by trap effect in the specimen. Simulation analysis using TMAP code on transient permeation behavior indicates the existence of a trap site with a trap energy of nearly 1eV and with a trap density of over several ten's ppm in tungsten

  18. Permeation of aromatic solvent mixtures through nitrile protective gloves.

    Science.gov (United States)

    Chao, Keh-Ping; Hsu, Ya-Ping; Chen, Su-Yi

    2008-05-30

    The permeation of binary and ternary mixtures of benzene, toluene, ethyl benzene and p-xylene through nitrile gloves were investigated using the ASTM F739 test cell. The more slowly permeating component of a mixture was accelerated to have a shorter breakthrough time than its pure form. The larger differences in solubility parameter between a solvent mixture and glove resulted in a lower permeation rate. Solubility parameter theory provides a potential approach to interpret the changes of permeation properties for BTEX mixtures through nitrile gloves. Using a one-dimensional diffusion model based on Fick's law, the permeation concentrations of ASTM F739 experiments were appropriately simulated by the estimated diffusion coefficient and solubility. This study will be a fundamental work for the risk assessment of the potential dermal exposure of workers wearing protective gloves.

  19. Permeation studies of novel terbinafine formulations containing hydrophobins through human nails in vitro.

    Science.gov (United States)

    Vejnovic, Ivana; Huonder, Cornelia; Betz, Gabriele

    2010-09-15

    Existing treatments of onychomycosis are not satisfactory. Oral therapies have many side effects and topical formulations are not able to penetrate into the human nail plate and deliver therapeutical concentrations of active agent in situ. The purpose of the present study was to determine the amount of terbinafine, which permeates through the human nail plate, from liquid formulations containing enhancers, namely hydrophobins A-C in the concentration of 0.1% (w/v). The used reference solution contained 10% (w/v) of terbinafine in 60% (v/v) ethanol/water without enhancer. Permeability studies have been performed on cadaver nails using Franz diffusion cells modified to mount nail plates and filled with 60% (v/v) ethanol/water in the acceptor chamber. Terbinafine was quantitatively determined by HPLC. The amount of terbinafine remaining in the nail was extracted by 96% ethanol from pulverized nail material after permeation experiment and presented as percentage of the dry nail weight before the milling test. Permeability coefficient (PC) of terbinafine from reference solution was determined to be 1.52E-10 cm/s. Addition of hydrophobins improved PC in the range of 3E-10 to 2E-9 cm/s. Remaining terbinafine reservoir in the nail from reference solution was 0.83% (n=2). An increase of remaining terbinafine reservoir in the nail was observed in two out of three tested formulations containing hydrophobins compared to the reference. In all cases, known minimum inhibitory concentration of terbinafine for dermatophytes (0.003 microg/ml) has been exceeded in the acceptor chamber of the diffusion cells. All tested proteins (hydrophobins) facilitated terbinafine permeation after 10 days of permeation experiment, however one of them achieved an outstanding enhancement factor of 13.05 compared to the reference. Therefore, hydrophobins can be included in the list of potential enhancers for treatment of onychomycosis. Copyright 2010 Elsevier B.V. All rights reserved.

  20. Transcorneal permeation of diclofenac as a function of temperature from film formulation in presence of triethanolamine and benzalkonium chloride.

    Science.gov (United States)

    Mohapatra, Rajaram; Senapati, Sibananda; Sahoo, Chinmaya; Mallick, Subrata

    2014-11-01

    The objective of this report was to evaluate the transcorneal permeation of diclofenac potassium (DCP) as a function of temperature from hydroxypropyl methylcellulose (HPMC) matrix film containing triethanolamine (TEM) as plasticizer and benzalkonium chloride (BKC) as preservative. Activation energy (Ea), enthalpy (ΔH), entropy (ΔS) and free energy (ΔG) of permeation, diffusion and partition were evaluated to understand the underlying mechanism of permeation. Permeation improved with the presence of both the plasticizer and preservative compared to preservative alone. Further, increased amount of TEM in the film increased drug transport across the cornea. Decreased Ea value of the film supported the fact. Rise of temperature from 26 to 30, 34 and 40 °C increased permeation in all the films. Ocular residence of the film in vivo in the rabbit revealed that the film swelled by pronounced lachrymal fluid uptake and traces of hydrogel remained still at the end of 6 h of application. Absence of characteristic exothermic peak of the drug in the thermogram of film formulations indicated the molecular dispersion of drug in polymer matrix. Scanning electron microscopy indicated that the drug crystal size decreased with increasing concentration of TEM in presence of BKC due to effective wetting of drug particles by the polymer. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Impact of changes in broth composition on Chlorella vulgaris cultivation in a membrane photobioreactor (MPBR) with permeate recycle.

    Science.gov (United States)

    Discart, V; Bilad, M R; Marbelia, L; Vankelecom, I F J

    2014-01-01

    A membrane photobioreactor (MPBR) is a proven and very useful concept in which microalgae can be simultaneously cultivated and pre-harvested. However, the behavior with respect to accumulation of algogenic organic matter, including transparent exopolymeric particles (TEPs), counter ions and unassimilated nutrients due to the recycling of the medium is still unclear, even though the understanding of this behavior is essential for the optimization of microalgae processing. Therefore, the dynamics of these compounds, especially TEPs, during coupled cultivation and harvesting of Chlorella vulgaris in an MPBR with permeate recycle are addressed in this study. Results show that TEPs are secreted during algae cell growth, and that their presence is thus inevitable. In the system with permeate recycle, substances such as counter ions and unassimilated nutrients get accumulated in the system. This was proven to limit the algae growth, together with the occurrence of bioflocculation due to an increasing broth pH. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Effects of hypothyroidism on vascular 125I-albumin permeation and blood flow in rats

    International Nuclear Information System (INIS)

    Tilton, R.G.; Pugliese, G.; Chang, K.; Speedy, A.; Province, M.A.; Kilo, C.; Williamson, J.R.

    1989-01-01

    Effects of hypothyroidism on vascular 125I-albumin permeation and on blood flow were assessed in multiple tissues of male Sprague-Dawley rats rendered hypothyroid by dietary supplementation with 0.5% (wt/wt) 2-thiouracil or by thyroidectomy. In both thiouracil-treated and thyroidectomized rats, body weights, kidney weight, arterial blood pressure, and pulse rate were decreased significantly v age-matched controls. After 10 to 12 weeks of thiouracil treatment, 125I-albumin permeation was increased significantly in the kidney, aorta, eye (anterior uvea, choroid, retina), skin, and new granulation tissue, remained unchanged in brain, sciatic nerve, and heart, and was decreased in forelimb skeletal muscle. A similar pattern was observed in thyroidectomized rats, except that increases in 125I-albumin permeation for all tissues were smaller than those observed in thiouracil-treated rats, and 125I-albumin permeation in retina did not differ from controls. In both thiouracil-treated and thyroidectomized rats, changes in blood flow (assessed with 15-microns, 85Sr-labeled microspheres) relative to the decrease in arterial blood pressure were indicative of a decrease in regional vascular resistance except in the choroid and in the kidney, in which vascular resistance was increased significantly. Glomerular filtration rate was decreased, but filtration fraction and urinary excretion of albumin remained unchanged by thiouracil treatment and thyroidectomy. These results indicate that vascular hemodynamics and endothelial cell barrier functional integrity are modulated in many different tissues by the thyroid. In view of the correspondence of hypothyroid- and diabetes-induced vascular permeability changes, these results raise the possibility that altered thyroid function in diabetes may play a role in the pathogenesis of diabetic vascular disease

  3. Effects of hypothyroidism on vascular /sup 125/I-albumin permeation and blood flow in rats

    Energy Technology Data Exchange (ETDEWEB)

    Tilton, R.G.; Pugliese, G.; Chang, K.; Speedy, A.; Province, M.A.; Kilo, C.; Williamson, J.R.

    1989-05-01

    Effects of hypothyroidism on vascular 125I-albumin permeation and on blood flow were assessed in multiple tissues of male Sprague-Dawley rats rendered hypothyroid by dietary supplementation with 0.5% (wt/wt) 2-thiouracil or by thyroidectomy. In both thiouracil-treated and thyroidectomized rats, body weights, kidney weight, arterial blood pressure, and pulse rate were decreased significantly v age-matched controls. After 10 to 12 weeks of thiouracil treatment, 125I-albumin permeation was increased significantly in the kidney, aorta, eye (anterior uvea, choroid, retina), skin, and new granulation tissue, remained unchanged in brain, sciatic nerve, and heart, and was decreased in forelimb skeletal muscle. A similar pattern was observed in thyroidectomized rats, except that increases in 125I-albumin permeation for all tissues were smaller than those observed in thiouracil-treated rats, and 125I-albumin permeation in retina did not differ from controls. In both thiouracil-treated and thyroidectomized rats, changes in blood flow (assessed with 15-microns, 85Sr-labeled microspheres) relative to the decrease in arterial blood pressure were indicative of a decrease in regional vascular resistance except in the choroid and in the kidney, in which vascular resistance was increased significantly. Glomerular filtration rate was decreased, but filtration fraction and urinary excretion of albumin remained unchanged by thiouracil treatment and thyroidectomy. These results indicate that vascular hemodynamics and endothelial cell barrier functional integrity are modulated in many different tissues by the thyroid. In view of the correspondence of hypothyroid- and diabetes-induced vascular permeability changes, these results raise the possibility that altered thyroid function in diabetes may play a role in the pathogenesis of diabetic vascular disease.

  4. Development of tritium permeation barriers on Al base in Europe

    Science.gov (United States)

    Benamati, G.; Chabrol, C.; Perujo, A.; Rigal, E.; Glasbrenner, H.

    The development of the water cooled lithium lead (WCLL) DEMO fusion reactor requires the production of a material capable of acting as a tritium permeation barrier (TPB). In the DEMO blanket reactor permeation barriers on the structural material are required to reduce the tritium permeation from the Pb-17Li or the plasma into the cooling water to acceptable levels (HIP) technology and spray (this one developed also for repair) deposition techniques. The final goal is to select a reference technique to be used in the blanket of the DEMO reactor and in the ITER test module fabrication. The activities performed in four European laboratories are summarised here.

  5. Reemission and permeation of deuterium implanted into metals

    International Nuclear Information System (INIS)

    Tanabe, T.; Furuyama, Y.; Imoto, S.

    1984-01-01

    Focusing on the marked depression of deuterium permeation rate during the deuteron bombardment, implantation experiments coupled with gaseous permeation experiments are performed on pure Ni and Ni with evaporated MnO. It is concluded that the reemission of implanted deuterium is initially depressed, but it soon becomes enhanced with increase of fluence leading to a rapid decrease of permeation rate at the intermediate temperatures 600-1000 K, which is attributed to the formation of short diffusion paths from the projected range to the front surface. (orig.)

  6. Permeation enhancer strategies in transdermal drug delivery.

    Science.gov (United States)

    Marwah, Harneet; Garg, Tarun; Goyal, Amit K; Rath, Goutam

    2016-01-01

    Today, ∼74% of drugs are taken orally and are not found to be as effective as desired. To improve such characteristics, transdermal drug delivery was brought to existence. This delivery system is capable of transporting the drug or macromolecules painlessly through skin into the blood circulation at fixed rate. Topical administration of therapeutic agents offers many advantages over conventional oral and invasive techniques of drug delivery. Several important advantages of transdermal drug delivery are prevention from hepatic first pass metabolism, enhancement of therapeutic efficiency and maintenance of steady plasma level of the drug. Human skin surface, as a site of drug application for both local and systemic effects, is the most eligible candidate available. New controlled transdermal drug delivery systems (TDDS) technologies (electrically-based, structure-based and velocity-based) have been developed and commercialized for the transdermal delivery of troublesome drugs. This review article covers most of the new active transport technologies involved in enhancing the transdermal permeation via effective drug delivery system.

  7. Permeation rates for RTF metal hydride vessels

    International Nuclear Information System (INIS)

    Klein, J.E.

    1992-01-01

    Contamination rates have been estimated for the RTF nitrogen heating and cooling system (NH and CS) due to tritium permeation through the walls of metal hydride vessels. Tritium contamination of the NH and CS will be seen shortly after start-up of the RTF with the majority of it coming from the TCAP units. Contamination rates of the NH and CS are estimated to exceed 400 Ci/year after three years of operation and will elevate tritium concentrations in the NH and CS above 6 x 10 -3 μCi/cc. To reduce tritium activity in the NH and CS, a stripper or ''getter'' bed may need to be installed in the NH and CS. Increasing the purge rate of nitrogen from the NH and CS is shown to be an impractical method for reducing tritium activity due to the high purge rates required. Stripping of the NH and CS nitrogen in the glove box stripper system will give a temporary lowering of tritium activity in the NH and CS, but tritium activity will return to its previous level in approximately two weeks

  8. Ion Permeation and Mechanotransduction Mechanisms of Mechanosensitive Piezo Channels.

    Science.gov (United States)

    Zhao, Qiancheng; Wu, Kun; Geng, Jie; Chi, Shaopeng; Wang, Yanfeng; Zhi, Peng; Zhang, Mingmin; Xiao, Bailong

    2016-03-16

    Piezo proteins have been proposed as the long-sought-after mechanosensitive cation channels in mammals that play critical roles in various mechanotransduction processes. However, the molecular bases that underlie their ion permeation and mechanotransduction have remained functionally undefined. Here we report our finding of the miniature pore-forming module of Piezo1 that resembles the pore architecture of other trimeric channels and encodes the essential pore properties. We further identified specific residues within the pore module that determine unitary conductance, pore blockage and ion selectivity for divalent and monovalent cations and anions. The non-pore-containing region of Piezo1 confers mechanosensitivity to mechano-insensitive trimeric acid-sensing ion channels, demonstrating that Piezo1 channels possess intrinsic mechanotransduction modules separate from their pore modules. In conclusion, this is the first report on the bona fide pore module and mechanotransduction components of Piezo channels, which define their ion-conducting properties and gating by mechanical stimuli, respectively. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Therapeutic impact of [18F]fluoride positron-emission tomography/computed tomography on patients with unclear foot pain

    International Nuclear Information System (INIS)

    Fischer, Dorothee Rita; Hesselmann, Rolf; Johayem, Anass; Hany, Thomas F.; Schulthess, Gustav K. von; Strobel, Klaus; Maquieira, Gerardo J.; Espinosa, Norman; Zanetti, Marco

    2010-01-01

    To evaluate the therapeutic impact of [ 18 F]fluoride positron-emission tomography/computed tomography ([ 18 F]fluoride PET/CT) imaging on patients with unclear foot pain. Twenty-eight patients were prospectively included in this study. Therapeutic management was defined by two experienced dedicated foot surgeons before and after [ 18 F]fluoride PET/CT imaging. Twenty-six patients underwent cross-sectional imaging [CT, magnetic resonance (MR)] prior to PET/CT. A retrospective analysis of the magnetic resonance imaging (MRI) diagnoses was performed when a therapy change occurred after PET/CT imaging. In 13/28 (46%) patients therapeutic management was changed due to PET/CT results. Management changes occurred in patients with the following diagnoses: os trigonum syndrome; sinus tarsi syndrome; os tibiale externum syndrome; osteoarthritis of several joints; non-consolidated fragments; calcaneo-navicular coalition; plantar fasciitis; insertional tendinopathy; suggestion of periostitis; neoarticulations between metatarsal bones. Os trigonum, os tibiale externum, subtalar osteoarthritis and plantar fasciitis were only seen to be active on PET/CT images but not on MR images. [ 18 F]fluoride PET/CT has a substantial therapeutic impact on management in patients with unclear foot pain. (orig.)

  10. Industry remains stuck in a transitional mode

    International Nuclear Information System (INIS)

    Garb, F.A.

    1991-01-01

    The near future for industry remains foggy for several obvious reasons. The shake-up of the Soviet Union and how the pieces will reform remains unclear. How successful efforts are to privatize government oil company operations around the world has yet to be determined. A long sought peace in the Middle East seems to be inching closer, but will this continue? If it does continue, what impact will it have on world energy policy? Will American companies, which are now transferring their attention to foreign E and P, also maintain an interest in domestic activities? Is the U.S. economy really on the upswing? We are told that the worst of the recession is over, but try telling this to thousands of workers in the oil patch who are being released monthly by the big players in domestic operations. This paper reports that 1992 should be a better year than 1991, if measured in opportunity. There are more exploration and acquisition options available, both domestically and internationally, than there have been in years. Probably more opportunities exist than there are players-certainly more than can be funded with current financial resources

  11. Study of tritium permeation through Peach Bottom Steam Generator tubes

    International Nuclear Information System (INIS)

    Yang, L.; Baugh, W.A.; Baldwin, N.L.

    1977-06-01

    The report describes the equipment developed, samples tested, procedures used, and results obtained in the tritium permeation tests conducted on steam generator tubing samples which were removed from the Peach Bottom Unit No. 1 reactor

  12. Recent results on implantation and permeation into fusion reactor materials

    Science.gov (United States)

    Anderl, R. A.; Holland, D. F.; Longhurst, G. R.; Struttman, D. A.

    This paper reports on implantation-driven permeation experiments that have been made for primary candidate alloy (PCA) and the ferritic steel HT-9 using deuterium ion beams from an accelerator. The results include measurements of the implantation flux and fluence dependence of the deuterium reemission and permeation for specimens heated to approximately 430(0)C. Simultaneous measurements of the ions sputtered from the specimen front surface with a secondary ion mass spectrometer provided some characterization of the surface condition throughout an experiment. For both materials, the permeation rate was lowered by the implantation process. However, the steady state permeation rate for HT-9 was found to be at least a factor of 5 greater than that for PCA.

  13. Phase Change Permeation Technology for Environmental Control & Life Support Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is evaluating Dutyion™, a phase change permeation membrane technology developed by Design Technology and Irrigation (DTI), for use in future advanced life...

  14. Effect of residual stresses on hydrogen permeation in iron

    International Nuclear Information System (INIS)

    Mouanga, M.; Bercot, P.; Takadoum, J.

    2010-01-01

    The effect of residual stresses on electrochemical permeation in iron membrane was investigated. Four thermal and mechanical treatments were chosen to obtain different surface states in relation to the residual stresses. Residual stresses were determined by X-ray diffraction (XRD) using the Macherauch and Mueller method. The results were completed by the microhardness measurements. For all iron membranes, compressive residual stresses were obtained. Electrochemical permeation experiments using a Devanathan and Stachurski cell were employed to determine the hydrogen permeation behaviour of the various iron membranes. The latter was charged with hydrogen by galvanostatic cathodic polarization in 0.1 M NaOH at 25 deg. C. The experimental results revealed that hydrogen permeation rate increases with increasing residual stresses introduced in iron membranes.

  15. Research on Crack-Filling Heat Treatment and Hydrogen Permeation Test of Self-healing Tritium Permeation Barriers

    Science.gov (United States)

    Liu, Dawei; Wang, Yan; Zhang, Ying; Ouyang, Taoyuan; Zhou, Tong; Fang, Xuanwei; Suo, Jinping

    2018-03-01

    A TiC + mixture (TiC/Al2O3 (1:1 wt.%)) +Al2O3 self-healing triple layer coating (TLC) was designed and manufactured by our group, and the crack-filling heat treatment process had been roughly explored in the past. In this work, the accelerating test with a thick TiC + mixture (TiC/Al2O3 (1:1 wt.%)) double-layer coating (DLC) was carried out. The DLC coating warped when the heat treatment temperature was lower than 550 °C, which was rare in similar researches, and it crushed into fan-shaped pieces when the treatment temperature was higher than 650 °C. The two different spalling failures were explained by weight gain, porosity and stress analyses. The heating rate had a significant effect. The bonding strength and hydrogen permeation of the TLC samples were also tested. Remaining at 650 °C for 40 h was proved to be an optimal crack-filling heat treatment process, considering the hydrogen resistance.

  16. Measurement of tritium permeation through resistant materials near room temperature

    International Nuclear Information System (INIS)

    Maienschein, J.; DuVal, V.; McMurphy, F.; Uribe, F.; Musket, R.; Brown, D.

    1985-01-01

    To measure tritium permeation through low-permeability materials at 50 to 170 0 C, we use highly-sensitive liquid scintillation counting to detect the permeating tritium. To validate our method, we conducted extensive experiments with copper, for which much data exists for comparison. We report permeability of tritium through copper at 50, 100, and 170 0 C, and discuss details of the experimental technique. Further plans are outlined. 15 refs., 5 figs., 1 tab

  17. Ultrasound-guided biopsy of greater omentum: An effective method to trace the origin of unclear ascites

    Energy Technology Data Exchange (ETDEWEB)

    Que Yanhong [Department of Ultrasound, First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001 (China)], E-mail: quebaobao@yahoo.com.cn; Wang Xuemei [Department of Ultrasound, First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001 (China)], E-mail: wxmlmt@yahoo.com.cn; Liu Yanjun [Department of Ultrasound, First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001 (China)], E-mail: lyj7512@sina.com; Li Ping [Department of Ultrasound, First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001 (China)], E-mail: liping7213@sina.com; Ou Guocheng [Department of Ultrasound, First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001 (China)], E-mail: yang9951@126.com; Zhao Wenjing [Department of Ultrasound, First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001 (China)], E-mail: awk999@163.com

    2009-05-15

    Objectives: Thickened greater omentum is encountered with high frequency in patients with ascites. The purpose of our study was to assess the utility of greater omentum biopsy under the guidance of ultrasound (US) in tracing the origin of unclear ascites and differentiating benign and malignant ascites. Materials and methods: We retrospectively reviewed our institutional database for all records of greater omentum biopsy cases. One hundred and ninety-four patients with unclear ascites and thickened greater omentum were included in the study. The sonograms of greater omentum were evaluated before undergoing the ultrasound-guided biopsy and a biopsy was considered successful if a specific benign or malignant diagnosis was rendered by the pathologist. Results: Successful biopsy was rendered for 182 biopsy procedures (93.8%, 182/194) including tuberculosis (n = 114), chronic inflammation (n = 3), metastases (n = 58), malignant mesothelioma (n = 6) and pseudomyxoma peritonei (n = 1). Twelve biopsies were non-diagnostic. According to the results of biopsy and follow-up, the sensitivity and specificity of biopsy in distinguishing malignant ascites from benign ascities were respectively 95.6% (65/68) and 92.9% (117/126). The greater omentum of 84 cases of tuberculous peritonitis showed 'cerebral fissure' sign and was well seen as an omental cake infiltrated with irregular nodules when involved by carcinomatosis. No 'cerebral fissure' sign was observed in peritoneal carcinomatosis. The sensitivity and specificity of this sign in indicating the existence of tuberculous peritonitis were 73.5% (89/121) and 100% (73/73). Moreover, if the specific 'cerebral fissure' sign was combined with the biopsy results, the specificity of biopsy in distinguishing malignant ascites from benign ascits increased to 96.8% (122/126). Conclusion: Ultrasound-guided biopsy of greater omentum is an important and effective method to diagnose the unclear ascites for

  18. Dopamine transporter imaging in clinically unclear cases of parkinsonism and the importance of Scans Without Evidence of Dopaminergic Deficit (SWEDDs

    Directory of Open Access Journals (Sweden)

    Marco A. T. Utiumi

    2012-09-01

    Full Text Available The clinical diagnosis of Parkinson's disease (PD is susceptible to misdiagnosis, especially in the earlier stages of the disease. Recently, in vivo imaging techniques assessing the presynaptic dopamine transporter (DAT have emerged as a useful tool in PD diagnosis, improving its accuracy. OBJECTIVE: It was to illustrate the clinical usefulness of a brain single-photon emission computed tomography (SPECT DAT ligand, and highlight relevant aspects of scans without evidence of dopaminergic deficit (SWEDDs in this context. CASES: We described four representative patients with clinically unclear parkinsonian syndromes who underwent [99mTc]-TRODAT-1 SPECT and reviewed the clinical implications. CONCLUSION: DAT-SPECT is an important, cost-effective, technique for the differential diagnosis of parkinsonian syndromes. Additionally, SWEDD cases present clinical and paraclinical peculiarities that may retrospectively identify them as essential/dystonic tremor. The lack of histopathological data limits further conclusions.

  19. Ozonation of nanofiltration permeate of whey before processing by reverse osmosis

    Directory of Open Access Journals (Sweden)

    Zmievskii Yurii G.

    2017-01-01

    Full Text Available During nanofiltration processing of whey a significant amount of permeate is generated. In some cases this permeate is treated by reverse osmosis to get purified water for technological needs. Dry substances are not used, because they contain practically the same amount of organic and inorganic components. Mineral substances can be used for the mineralization of drinking water purified by reverse osmosis. However, the presence of organic compounds complicates the process of separation, as well as reduces the specific productivity of reverse osmosis membranes at the concentration stage. Therefore, the search for methods of destruction and removal of organic components is grounded. In the presented work, experimental studies of ozonation and sorption of organic compounds by activated carbon were carried. It has been shown that ozonation improves the degree of sorption purification by six times. Sequential treatment with ozone and subsequent filtration through the layer of activated carbon improves the specific productivity of reverse osmosis membranes by 30% at the stage of treatment of the nanofiltration permeate, while their selectivity remains unchanged.

  20. And the Dead Remain Behind

    Directory of Open Access Journals (Sweden)

    Peter Read

    2013-08-01

    Full Text Available In most cultures the dead and their living relatives are held in a dialogic relationship. The dead have made it clear, while living, what they expect from their descendants. The living, for their part, wish to honour the tombs of their ancestors; at the least, to keep the graves of the recent dead from disrepair. Despite the strictures, the living can fail their responsibilities, for example, by migration to foreign countries. The peripatetic Chinese are one of the few cultures able to overcome the dilemma of the wanderer or the exile. With the help of a priest, an Australian Chinese migrant may summon the soul of an ancestor from an Asian grave to a Melbourne temple, where the spirit, though removed from its earthly vessel, will rest and remain at peace. Amongst cultures in which such practices are not culturally appropriate, to fail to honour the family dead can be exquisitely painful. Violence is the cause of most failure.

  1. Electrochemical measurement of tritium and hydrogen permeation through iron membranes

    International Nuclear Information System (INIS)

    Hagi, Hideki; Hayashi, Yasunori

    1987-01-01

    Permeation rates of tritium and hydrogen through iron were measured by the electro-chemical method in which an aqueous solution containing 3.7 x 10 12 Bq/m 3 tritium was used as a cathodic electrolyte. Tritium and hydrogen were introduced from one side of a specimen by cathodic polarization with a constant current density, while at the other side of the specimen the permeated tritium and hydrogen were extracted by potentiostatical ionization. Nearly all of the potentiostatic current on the extraction side is produced by the ionization of hydrogen, because the concentration of tritium in the cathodic electrolyte is very small. The amount of permeated hydrogen was obtained by integrating the potentiostatic current, and that of permeated tritium was determined by measuring the radioactivity of the electrolyte sampled from the anodic side. The separation factor for permeation obtained under steady state conditions (the ratio of permeation rates of hydrogen to tritium divided by the ratio of the concentration of hydrogen to tritium in the cathodic electrolyte) is 12 at 288 K. This value is independent of cathodic current density. Diffusion coefficients of tritium (D T ) and hydrogen (D H ) in iron were determined from the tritium and hydrogen permeation by using time lag technique. For annealed iron at 286 K, D T = 9 x 10 -10 m 2 /s and D H = 4 x 10 -9 m 2 /s, and for 9 % cold-worked iron at 284 K, D T = 3 x 10 -10 m 2 /s and D H = 4 x 10 -10 m 2 /s. (author)

  2. Families and health-care professionals' perspectives and expectations of family-centred care: hidden expectations and unclear roles.

    Science.gov (United States)

    Coyne, Imelda

    2015-10-01

    Family-centred care (FCC) is viewed as a pivotal concept in the provision of high-quality nursing care for children and their families, yet implementation continues to be problematic worldwide. This research investigated how FCC was enacted from families and nurses' perspectives. Descriptive qualitative approach using elements of analysis from grounded theory method. Data were collected though individual interviews with 18 children aged 7-16 years, their parents (n = 18) and 18 nurses from two children's hospital and one children's unit in a large general hospital in Ireland. Four key themes were identified: expectations; relying on parents' help; working out roles; and barriers to FCC. Nurses wholeheartedly endorsed FCC because of the benefits for families and their reliance on parents' contribution to the workload. There was minimal evidence of collaboration or negotiation of roles which resulted in parents feeling stressed or abandoned. Nurses cited busy workload, under-staffing and inappropriate documentation as key factors which resulted in over-reliance on parents and hindered their efforts to negotiate and work alongside parents. Families are willing to help in their child's care but they require clear guidance, information and support from nurses. Hidden expectations and unclear roles are stressful for families. Nurses need skills training, adequate resources and managerial support to meet families' needs appropriately, to establish true collaboration and to deliver optimal family-centred care. © 2013 John Wiley & Sons Ltd.

  3. Red Assembly: the work remains

    Directory of Open Access Journals (Sweden)

    Leslie Witz

    installed. What to do at this limit, at the transgressive encounter between saying yes and no to history, remains the challenge. It is the very challenge of what insistently remains.

  4. Green business will remain green

    International Nuclear Information System (INIS)

    Marcan, P.

    2008-01-01

    It all started with two words. Climate change. The carbon dioxide trading scheme, which was the politicians' idea on solving the number one global problem, followed. Four years ago, when the project was begun, there was no data for project initiation. Quotas for polluters mainly from energy production and other energy demanding industries were distributed based on spreadsheets, maximum output and expected future development of economies. Slovak companies have had a chance to profit from these arrangements since 2005. Many of them took advantage of the situation and turned the excessive quotas into an extraordinary profit which often reached hundreds of million Sk. The fact that the price of free quotas offered for sale dropped basically to 0 in 2006 only proved that the initial distribution was too generous. And the market reacted to the first official measurements of emissions. Slovak companies also contributed to this development. However, when planning the maximum emission volumes for 2008-2012 period, in spite of the fact that actual data were available, their expectations were not realistic. A glance at the figures in the proposal of the Ministry of Environment is sufficient to realize that there will be no major change in the future. And so for many Slovak companies business with a green future will remain green for the next five years. The state decided to give to selected companies even more free space as far as emissions are concerned. The most privileged companies can expect quotas increased by tens of percent. (author)

  5. Silicon photonics: some remaining challenges

    Science.gov (United States)

    Reed, G. T.; Topley, R.; Khokhar, A. Z.; Thompson, D. J.; Stanković, S.; Reynolds, S.; Chen, X.; Soper, N.; Mitchell, C. J.; Hu, Y.; Shen, L.; Martinez-Jimenez, G.; Healy, N.; Mailis, S.; Peacock, A. C.; Nedeljkovic, M.; Gardes, F. Y.; Soler Penades, J.; Alonso-Ramos, C.; Ortega-Monux, A.; Wanguemert-Perez, G.; Molina-Fernandez, I.; Cheben, P.; Mashanovich, G. Z.

    2016-03-01

    This paper discusses some of the remaining challenges for silicon photonics, and how we at Southampton University have approached some of them. Despite phenomenal advances in the field of Silicon Photonics, there are a number of areas that still require development. For short to medium reach applications, there is a need to improve the power consumption of photonic circuits such that inter-chip, and perhaps intra-chip applications are viable. This means that yet smaller devices are required as well as thermally stable devices, and multiple wavelength channels. In turn this demands smaller, more efficient modulators, athermal circuits, and improved wavelength division multiplexers. The debate continues as to whether on-chip lasers are necessary for all applications, but an efficient low cost laser would benefit many applications. Multi-layer photonics offers the possibility of increasing the complexity and effectiveness of a given area of chip real estate, but it is a demanding challenge. Low cost packaging (in particular, passive alignment of fibre to waveguide), and effective wafer scale testing strategies, are also essential for mass market applications. Whilst solutions to these challenges would enhance most applications, a derivative technology is emerging, that of Mid Infra-Red (MIR) silicon photonics. This field will build on existing developments, but will require key enhancements to facilitate functionality at longer wavelengths. In common with mainstream silicon photonics, significant developments have been made, but there is still much left to do. Here we summarise some of our recent work towards wafer scale testing, passive alignment, multiplexing, and MIR silicon photonics technology.

  6. Hydrogen permeation properties of plasma-sprayed tungsten

    International Nuclear Information System (INIS)

    Anderl, R.A.; Pawelko, R.J.; Hankins, M.R.; Longhurst, G.R.; Neiser, R.A.

    1994-01-01

    Tungsten has been proposed as a plasma-facing component material for advanced fusion facilities. This paper reports on laboratory-scale studies that were done to assess the hydrogen permeation properties of plasma-sprayed tungsten for such applications. The work entailed deuterium permeation measurements for plasma-sprayed (PS) tungsten coatings, sputter-deposited (SP) tungsten coatings, and steel substrate material using a mass-analyzed, 3 keV D + 3 ion beam with fluxes of similar 6.5x10 19 D/m 2 s. Extensive characterization analyses for the plasma-sprayed tungsten coatings were made using Auger spectrometry and scanning electron microscopy (SEM). Observed permeation rates through composite PS-tungsten/steel specimens were several orders of magnitude below the permeation levels observed for SP-tungsten/steel composite specimens and pure steel specimens. Characterization analyses indicated that the plasma-sprayed tungsten coating had a nonhomogeneous microstructure that consisted of splats with columnar solidification, partially-melted particles with grain boundaries, and void regions. Reduced permeation levels can be attributed to the complex microstructure and a substantial surface-connected porosity. ((orig.))

  7. Hydrogen permeation properties of plasma-sprayed tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A. (Idaho National Engineering Lab., EG and G Idaho Inc., Idaho Falls, ID (United States)); Pawelko, R.J. (Idaho National Engineering Lab., EG and G Idaho Inc., Idaho Falls, ID (United States)); Hankins, M.R. (Idaho National Engineering Lab., EG and G Idaho Inc., Idaho Falls, ID (United States)); Longhurst, G.R. (Idaho National Engineering Lab., EG and G Idaho Inc., Idaho Falls, ID (United States)); Neiser, R.A. (Sandia National Laboratories, Albuquerque, NM 87185 (United States))

    1994-09-01

    Tungsten has been proposed as a plasma-facing component material for advanced fusion facilities. This paper reports on laboratory-scale studies that were done to assess the hydrogen permeation properties of plasma-sprayed tungsten for such applications. The work entailed deuterium permeation measurements for plasma-sprayed (PS) tungsten coatings, sputter-deposited (SP) tungsten coatings, and steel substrate material using a mass-analyzed, 3 keV D[sup +][sub 3] ion beam with fluxes of similar 6.5x10[sup 19] D/m[sup 2] s. Extensive characterization analyses for the plasma-sprayed tungsten coatings were made using Auger spectrometry and scanning electron microscopy (SEM). Observed permeation rates through composite PS-tungsten/steel specimens were several orders of magnitude below the permeation levels observed for SP-tungsten/steel composite specimens and pure steel specimens. Characterization analyses indicated that the plasma-sprayed tungsten coating had a nonhomogeneous microstructure that consisted of splats with columnar solidification, partially-melted particles with grain boundaries, and void regions. Reduced permeation levels can be attributed to the complex microstructure and a substantial surface-connected porosity. ((orig.))

  8. Hydrogen permeation properties of plasma-sprayed tungsten*1

    Science.gov (United States)

    Anderl, R. A.; Pawelko, R. J.; Hankins, M. R.; Longhurst, G. R.; Neiser, R. A.

    1994-09-01

    Tungsten has been proposed as a plasma-facing component material for advanced fusion facilities. This paper reports on laboratory-scale studies that were done to assess the hydrogen permeation properties of plasma-sprayed tungsten for such applications. The work entailed deuterium permeation measurements for plasma-sprayed (PS) tungsten coatings, sputter-deposited (SP) tungsten coatings, and steel substrate material using a mass-analyzed, 3 keV D 3+ ion beam with fluxes of ˜6.5 × 10 19 D/m 2 s. Extensive characterization analyses for the plasma-sprayed tungsten coatings were made using Auger spectrometry and scanning electron microscopy (SEM). Observed permeation rates through composite PS-tungsten/steel specimens were several orders of magnitude below the permeation levels observed for SP-tungsten/steel composite specimens and pure steel specimens. Characterization analyses indicated that the plasma-sprayed tungsten coating had a nonhomogeneous microstructure that consisted of splats with columnar solidification, partially-melted particles with grain boundaries, and void regions. Reduced permeation levels can be attributed to the complex microstructure and a substantial surface-connected porosity.

  9. Drug Release and Skin Permeation from Lipid Liquid Crystalline Phases

    Science.gov (United States)

    Costa-Balogh, F. O.; Sparr, E.; Sousa, J. J. S.; Pais, A. A. C. C.

    We have studied drug release and skin permeation from several different liquid crystalline lipid formulations that may be used to control the respective release rates. We have studied the release and permeation through human skin of a water-soluble and amphiphilic drug, propranolol hydrochloride, from several formulations prepared with monoolein and phytantriol as permeation enhancers and controlled release excipients. Diolein and cineol were added to selected formulations. We observed that viscosity decreases with drug load, wich is compatible with the occurrence of phase changes. Diolein stabilizes the bicontinuous cubic phases leading to an increase in viscosity and sustained release of the drug. The slowest release was found for the cubic phases with higher viscosity. Studies on skin permeation showed that these latter formulations also presented lower permeability than the less viscous monoolein lamellar phases. Formulations containing cineol originated higher permeability with higher enhancement ratios. Thus, the various formulations are adapted to different circumstances and delivery routes. While a slow release is usually desired for drug sustained delivery, the transdermal route may require a faster release. Lamellar phases, which are less viscous, are more adapted to transdermal applications. Thus, systems involving lamellar phases of monoolein and cineol are good candidates to be used as skin permeation enhancers for propranolol hydrochloride.

  10. Recent developments in skin mimic systems to predict transdermal permeation.

    Science.gov (United States)

    Waters, Laura J

    2015-01-01

    In recent years there has been a drive to create experimental techniques that can facilitate the accurate and precise prediction of transdermal permeation without the use of in vivo studies. This review considers why permeation data is essential, provides a brief summary as to how skin acts as a natural barrier to permeation and discusses why in vivo studies are undesirable. This is followed by an in-depth discussion on the extensive range of alternative methods that have been developed in recent years. All of the major 'skin mimic systems' are considered including: in vitro models using synthetic membranes, mathematical models including quantitative structure-permeability relationships (QSPRs), human skin equivalents and chromatographic based methods. All of these model based systems are ideally trying to achieve the same end-point, namely a reliable in vitro-in vivo correlation, i.e. matching non-in vivo obtained data with that from human clinical trials. It is only by achieving this aim, that any new method of obtaining permeation data can be acknowledged as a potential replacement for animal studies, for the determination of transdermal permeation. In this review, the relevance and potential applicability of the various models systems will also be discussed.

  11. Permeation of cytotoxic formulations through swatches from selected medical gloves.

    Science.gov (United States)

    Klein, Michael; Lambov, Nikolai; Samev, Nikola; Carstens, Gerhard

    2003-05-15

    The permeability of selected medical glove materials to various cytotoxic agents is described. Fifteen cytotoxic agents were prepared at the highest concentrations normally encountered by hospital personnel. Four single-layer and two double-layer glove systems made of two materials--latex and neoprene--were exposed to the drugs for 30, 60, 90, 120, 150, and 180 minutes. Circular sections of the glove material were cut from the cuff and evaluated without any pretreatment. Permeability tests were conducted in an apparatus consisting of a donor chamber containing the cytotoxic solution and a collection chamber filled with water (the acceptor medium). The two sections were separated by the glove material. Permeating portions, collected in water as the acceptor medium, were analyzed by either ultraviolet-visible light spectrophotometry or high-performance liquid chromatography (HPLC). Permeation rates were calculated on the basis of the concentration of the cytotoxic agent in the acceptor medium. Spectrophotometric measurements were taken every 30 minutes, and HPLC analysis was performed at the end of the three-hour period. Average permeation rates for 14 drugs were low (materials. All glove materials tested were impermeable to most of the cytotoxic agents over a period of three hours. Carmustine was the only agent that substantially permeated single-layer latex glove materials. Permeation of most tested cytotoxic formulations was low through swatches of material from various medical gloves.

  12. The influence of pH on the in vitro permeation of rhodium through human skin.

    Science.gov (United States)

    Jansen Van Rensburg, Sané; Franken, Anja; Du Plessis, Jeanetta; Du Plessis, Johannes Lodewykus

    2017-06-01

    Workers in precious metals refineries are at risk of exposure to salt compounds of the platinum group metals through inhalation, as well as through the skin. Rhodium salt permeation through the skin has previously been proven using rhodium trichloride (RhCl 3 ) dissolved in synthetic sweat at a pH of 6.5. However, the skin surface pH of refinery workers may be lower than 6.5. The aim of this study was to investigate the influence of pH 6.5 and 4.5 on the in vitro permeation of rhodium through intact Caucasian skin using Franz diffusion cells. A concentration of 0.3 mg mL -1 rhodium was used and analyses were performed using inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry. Results indicated a cumulative increase in permeation over 24 h. Rhodium permeation after 12 h was significantly greater at pH 4.5 (1.56 ± 0.24 ng cm -2 ) than at 6.5 (0.85 ± 0.13 ng cm -2 ; p = 0.02). At both pH levels, there was a highly significant difference ( p rhodium remaining in the skin (1428.68 ± 224.67 ng cm -2 at pH 4.5 and 1029.90 ± 115.96 ng cm -2 at pH 6.5) and the mass that diffused through (0.88 ± 0.17 ng cm -2 at pH 4.5 and 0.62 ± 0.10 ng cm -2 at pH 6.5). From these findings, it is evident that an acidic working environment or low skin surface pH may enhance permeation of rhodium salts, contributing to sensitization and adverse health effects.

  13. Double electrolyte sensor for monitoring hydrogen permeation rate in steels

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang, Y.J. [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Department of Chemistry and Chemical Engineering, Huaihua College, Huaihua 418008 (China); Yu, G., E-mail: yuganghnu@163.co [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Ou, A.L.; Hu, L.; Xu, W.J. [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

    2011-06-15

    Highlights: {yields} Designed an amperometric hydrogen sensor with double electrolytes. {yields} Explained the principle of determining hydrogen permeation rate. {yields} Verified good stability, reproducibility and correctness of the developed sensor. {yields} Field on-line monitoring the susceptivity of hydrogen induced cracks. - Abstract: An amperometric hydrogen sensor with double electrolytes composed of a gelatiniform electrolyte and KOH solution has been developed to determine the permeation rate of hydrogen atoms in steel equipment owing to hydrogen corrosion. The gelatiniform electrolyte was made of sodium polyacrylate (PAAS), carboxyl methyl cellulose (CMC) and 0.2 mol dm{sup -3} KOH solution. The results show that the gelatiniform electrolyte containing 50 wt.% polymers has suitable viscosity and high electrical conductivity. The consistent permeation curves were detected by the sensor of the double electrolyte and single liquid KOH electrolyte, respectively. The developed sensor has good stability and reproducibility at room temperature.

  14. Deuterium permeation and diffusion in high-purity beryllium

    International Nuclear Information System (INIS)

    Abramov, E.; Riehm, M.P.; Thompson, D.A.; Smeltzer, W.W.

    1990-01-01

    The permeation rate of deuterium through high-purity beryllium membranes was measured using the gas-driven permeation technique. The time-dependent and the steady-state deuterium flux data were analyzed and the effective diffusivities of the samples were determined. Using multilayer permeation theory the effects of surface oxide were eliminated and the diffusion coefficients of the bulk beryllium determined. The diffusion parameters obtained for the extra-grade beryllium samples (99.8%) are D 0 =6.7x10 -9 m 2 /s and E D =28.4 kJ/mol. For the high-grade beryllium samples (99%) the parameters are D 0 =8.0x10 -9 m 2 /s and E D =35.1 kJ/mol. (orig.)

  15. Deuterium permeation and diffusion in high purity beryllium

    International Nuclear Information System (INIS)

    Abramov, E.

    1990-05-01

    The permeation rate of deuterium through high-purity beryllium membranes was measured using the gas-driven permeation technique. The time-dependent and the steady-state deuterium flux data were analyzed and the effective diffusivities of the samples were determined. A multilayer permeation theory was used in order to eliminate the surface oxide effects and the diffusion coefficients of the bulk beryllium were determined. The diffusion parameters obtained for the extra-grade beryllium samples (99.8%) are D 0 = 6.7 x 10 -9 [m 2 /s] and E D = 28.4 [KJ/mol]; and for the high-grade beryllium samples (99%) the parameters are D 0 = 8.0 x 10 -9 [m 2 /s] and E D = 35.1 [KJ/mol

  16. Double electrolyte sensor for monitoring hydrogen permeation rate in steels

    International Nuclear Information System (INIS)

    Ouyang, Y.J.; Yu, G.; Ou, A.L.; Hu, L.; Xu, W.J.

    2011-01-01

    Highlights: → Designed an amperometric hydrogen sensor with double electrolytes. → Explained the principle of determining hydrogen permeation rate. → Verified good stability, reproducibility and correctness of the developed sensor. → Field on-line monitoring the susceptivity of hydrogen induced cracks. - Abstract: An amperometric hydrogen sensor with double electrolytes composed of a gelatiniform electrolyte and KOH solution has been developed to determine the permeation rate of hydrogen atoms in steel equipment owing to hydrogen corrosion. The gelatiniform electrolyte was made of sodium polyacrylate (PAAS), carboxyl methyl cellulose (CMC) and 0.2 mol dm -3 KOH solution. The results show that the gelatiniform electrolyte containing 50 wt.% polymers has suitable viscosity and high electrical conductivity. The consistent permeation curves were detected by the sensor of the double electrolyte and single liquid KOH electrolyte, respectively. The developed sensor has good stability and reproducibility at room temperature.

  17. Control of tritium permeation through fusion reactor strucural materials

    International Nuclear Information System (INIS)

    Maroni, V.A.

    1978-01-01

    The intention of this paper is to provide a brief synopsis of the status of understanding and technology pertaining to the dissolution and permeation of tritium in fusion reactor materials. The following sections of this paper attempt to develop a simple perspective for understanding the consequences of these phenomena and the nature of the technical methodology being contemplated to control their impact on fusion reactor operation. Considered in order are: (1) the occurrence of tritium in the fusion fuel cycle, (2) a set of tentative criteria to guide the analysis of tritium containment and control strategies, (3) the basic mechanisms by which tritium may be released from a fusion plant, and (4) the methods currently under development to control the permeation-related release mechanisms. To provide background and support for these considerations, existing solubility and permeation data for the hydrogen isotopes are compared and correlated under conditions to be expected in fusion reactor systems

  18. Permeation of "Hydromer" Film: An Elastomeric Hydrogen-Capturing Biopolymer.

    Energy Technology Data Exchange (ETDEWEB)

    Karnesky, Richard A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Friddle, Raymond William [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Whaley, Josh A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Smith, Geoffrey [New Mexico State Univ., Las Cruces, NM (United States)

    2015-12-01

    This report analyzes the permeation resistance of a novel and proprietary polymer coating for hydrogen isotope resistance that was developed by New Mexico State University. Thermal gravimetric analysis and thermal desoprtion spectroscopy show the polymer is stable thermally to approximately 250 deg C. Deuterium gas-driven permeation experiments were conducted at Sandia to explore early evidence (obtained using Brunauer - Emmett - Teller) of the polymer's strong resistance to hydrogen. With a relatively small amount of the polymer in solution (0.15%), a decrease in diffusion by a factor of 2 is observed at 100 and 150 deg C. While there was very little reduction in permeability, the preliminary findings reported here are meant to demonstrate the sensitivity of Sandia's permeation measurements and are intended to motivate the future exploration of thicker barriers with greater polymer coverage.

  19. The formation of tritium permeation barriers by CVD

    International Nuclear Information System (INIS)

    Forcey, K.S.; Perujo, A.; Reiter, F.; Lolli-Ceroni, P.L.

    1993-01-01

    The effectiveness as permeation barriers of the following CVD coatings have been investigated: TiC (1 to 2 μm in thickness); a bi-layer of TiN on TiC (3 μm total thickness) and CVD Al 2 O 3 on a TiN/TiC bi-layer. The substrate materials were TZM (a Mo alloy) and 316L stainless steel in the form of discs of diameter 48 mm and thickness 0.1 or 1 mm. Permeation measurements were performed in the temperature range 515-742 K using deuterium at pressures in the range 1-50 kPa. CVD layers were shown to form reasonably effective permeation barriers. At a temperature of 673 K TiC is around 6000 times less permeable to deuterium than 316L stainless steel. (orig.)

  20. Ion-driven deuterium permeation through tungsten at high temperatures

    Science.gov (United States)

    Gasparyan, Yu. M.; Golubeva, A. V.; Mayer, M.; Pisarev, A. A.; Roth, J.

    2009-06-01

    The ion-driven permeation (IDP) through 50 μm thick pure tungsten foils was measured in the temperature range of 823-923 K during irradiation by 200 eV/D + ion beam with a flux of 10 17-10 18 D/m 2s. Gas driven permeation (GDP) from the deuterium background gas was observed as well. Calculations using both the analytical formula for the diffusion limited regime (DLR) and the TMAP 7 code gave good agreement with the experimental data. Defects with a detrapping energy of (2.05 ± 0.15) eV were found to limit the permeation lag time in our experimental conditions.

  1. Ion-driven deuterium permeation through tungsten at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Gasparyan, Yu.M., E-mail: yury.gasparyan@ipp.mpg.d [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmanstrasse 2, D-85748 Garching (Germany); Moscow Engineering and Physics Institute, Kashirskoe sh. 31, Moscow 115409 (Russian Federation); Golubeva, A.V. [RRC ' Kurchatov Institute' , Ac. Kurchatov sq., 1/1, Moscow RU-123182 (Russian Federation); Mayer, M. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmanstrasse 2, D-85748 Garching (Germany); Pisarev, A.A. [Moscow Engineering and Physics Institute, Kashirskoe sh. 31, Moscow 115409 (Russian Federation); Roth, J. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmanstrasse 2, D-85748 Garching (Germany)

    2009-06-15

    The ion-driven permeation (IDP) through 50 mum thick pure tungsten foils was measured in the temperature range of 823-923 K during irradiation by 200 eV/D{sup +} ion beam with a flux of 10{sup 17}-10{sup 18} D/m{sup 2}s. Gas driven permeation (GDP) from the deuterium background gas was observed as well. Calculations using both the analytical formula for the diffusion limited regime (DLR) and the TMAP 7 code gave good agreement with the experimental data. Defects with a detrapping energy of (2.05 +- 0.15) eV were found to limit the permeation lag time in our experimental conditions.

  2. Ion-driven deuterium permeation through tungsten at high temperatures

    International Nuclear Information System (INIS)

    Gasparyan, Yu.M.; Golubeva, A.V.; Mayer, M.; Pisarev, A.A.; Roth, J.

    2009-01-01

    The ion-driven permeation (IDP) through 50 μm thick pure tungsten foils was measured in the temperature range of 823-923 K during irradiation by 200 eV/D + ion beam with a flux of 10 17 -10 18 D/m 2 s. Gas driven permeation (GDP) from the deuterium background gas was observed as well. Calculations using both the analytical formula for the diffusion limited regime (DLR) and the TMAP 7 code gave good agreement with the experimental data. Defects with a detrapping energy of (2.05 ± 0.15) eV were found to limit the permeation lag time in our experimental conditions.

  3. Electrochemical measurement of tritium and hydrogen permeation through iron membranes

    International Nuclear Information System (INIS)

    Hagi, Hideki; Hayashi, Yasunori

    1988-01-01

    Permeation rates of tritium and hydrogen through iron were measured by the electrochemical method in which an aqueous solution containing 3.7 x 10 12 Bq/m 3 tritium was used as a cathodic electrolyte. Tritium and hydrogen were introduced from one side of a specimen by cathodic polarization with a constant current density, while at the other side of the specimen the permeated tritium and hydrogen were extracted by potentiostatical ionization. Nearly all of the potentiostatic current of the extraction side stands for the ionization of hydrogen, because the concentration of tritium in the cathodic electrolyte is very small. The amount of permeated hydrogen was obtained by integrating the anodic current, and that of tritium was determined by measuring the radioactivity of the electrolyte sampled from the extraction side. The separation factor for permeation obtained under steady state conditions (the ratio of permeation rates of hydrogen to tritium divided by the ratio of the concentration of hydrogen to tritium in the charging electrolyte) is 12 at 288 K. This value is independent of cathodic current density. Diffusion coefficients of tritium (D T ) and hydrogen (D H ) in iron were determined from the time lag of tritium and hydrogen permeation. For annealed specimens at 286 K, D T = 9 x 10 -10 m 2 /s and D H = 4 x 10 -9 m 2 /s, and for 9% cold-worked specimens at 284 K, D T = 3 x 10 -10 m 2 /s and D H = 4 x 10 -10 m 2 /s. (author)

  4. Tritium inventory and permeation in the ITER breeding blanket

    International Nuclear Information System (INIS)

    Violante, V.; Tosti, S.; Sibilia, C.; Felli, F.; Casadio, S.; Alvani, C.

    2000-01-01

    A model has allowed us to perform the analysis of the tritium inventory and permeation in the international thermonuclear experimental reactor (ITER) breeding blanket under the hypothesis of steady state conditions. Li 2 ZrO 3 (reference) and Li 2 TiO 3 (alternative) have been studied as breeding materials. The total breeder inventory assessed is 7.64 g for the Li 2 ZrO 3 at reference temperature. The model has also been used for a parametric analysis of the tritium permeation. At reference temperature and purge helium velocity of 0.01 m/s, the HT partial pressure is ranging from 10 to 30 Pa in the breeder and 1.5x10 -3 Pa in the beryllium. At 0.1 m/s of purge helium velocity, the HT partial pressure is reduced of one order by magnitude in the breeder and becomes 5x10 -5 Pa in the beryllium. The tritium permeation into the coolant for the whole blanket is ranging from 100 to 250 mCi per day for purge helium velocity of 0.01 m/s. The analysis of the tritium inventory and permeation for the alternative Li 2 TiO 3 breeding material has been carried out too. The tritium inventory in the breeder is in the range from 6 to 375 g larger than in Li 2 ZrO 3 by about a factor 5; the tritium permeation into coolant is comparable to the Li 2 ZrO 3 one. This analysis provides indications on the influence of the operating parameters on the tritium control in the ITER breeding blanket; particularly the control of the tritium inventory by the temperature and the tritium permeation by the purge gas velocity

  5. Implantation measurements to determine tritium permeation in first wall structures

    International Nuclear Information System (INIS)

    Holland, D.F.; Causey, R.A.

    1983-01-01

    A principal safety concern for a D-T burning fusion reactor is release of tritium during routine operation. Tritium implantation into first wall structures, and subsequent permeation into coolants, is potentially an important source of tritium loss. This paper reports on an experiment in which an ion accelerator was used to implant deuterium atoms in a stainless steel disk to simulate tritium implantation in first wall structures. The permeation rate was measured under various operating conditions. These results were used in the TMAP computer code to determine potential tritium loss rates for fusion reactors

  6. Permeation Barrier Coatings for the Helical Heat Exchanger

    International Nuclear Information System (INIS)

    Korinko, P.S.

    1999-01-01

    A permeation barrier coating was specified for the Helical Heat Exchanger (HHE) to minimize contamination through emissions and/or permeation into the nitrogen system for ALARA reasons. Due to the geometry of the HHE, a special coating practice was needed since the conventional method of high temperature pack aluminization was intractable. A survey of many coating companies was undertaken; their coating capabilities and technologies were assessed and compared to WSRC needs. The processes and limitations to coating the HHE are described. Slurry coating appears to be the most technically sound approach for coating the HHE

  7. Permeation of deuterium implanted into V-15Cr-5Ti

    International Nuclear Information System (INIS)

    Anderl, R.A.; Longhurst, G.R.; Struttmann, D.A.

    1987-01-01

    Permeation and reemission of deuterium for the vanadium alloy, V-15Cr-5Ti, was investigated using 3 keV, D 3 + ion beams from a small accelerator. The experiments consisted of measurement of the deuterium reemission and permeation rates as a function of implantation fluence for 0.5 mm thick specimens heated to temperatures from 623 K to 823 K. Implantation-side surface characterization was made by simultaneous measurements of sputtered ions with a secondary ion mass spectrometer (SIMS). For the experimental conditions used, the steady-state deuterium permeation flux in V-15Cr-5Ti is approximately 18% of the implantation flux. This is approximately 1000 times that seen in the austenitic stainless steel, PCA, and 200 times that seen in the ferritic steel, HT-9, under comparable conditions. Measurement of deuterium diffusivity in V-15Cr-5Ti using permeation break-through times indicates that D = 1.4x10 -8 exp(-0.11 eV/kT)(m 2 /s), over the temperature range 723 K to 823 K. (orig.)

  8. Hydrogen ion-driven permeation in carbonaceous films

    International Nuclear Information System (INIS)

    Anderl, R.A.; Holland, D.F.; Longhurst, G.R.

    1989-01-01

    This paper presents the results of investigations into the permeation properties of amorphous carbonaceous, a-C:H, films produced by plasmachemical deposition techniques. Carbonaceous films on iron substrates with thickness ranging from 60 nm to 110 nm were subjected to high fluence implantations with mass analyzed D 3 + ions with energies ranging from 600 eV to 3000 eV and fluxes ranging from 5x10 14 D/cm 2 s to 5x10 15 D/cm 2 s, respectively. Deuterium re-emission upstream, deuterium permeation downstream and secondary ions sputtered from the implantation surface were measured as a function of implantation fluence for specimens at 420 K. The present studies indicate that the a-C:H film permeability is directly related to the time, hence the fluence, required to achieve isotopic replacement and saturation of the deuterium ion beam atoms stopped in the implant region. Once the deuterium saturation level is achieved in the layer, a significant fraction of the implanting ions can result in permeation. For the present experiment, this permeation factor was much higher than that for uncoated iron specimens subjected to similar beam conditions. Carbon sputter yields of 0.008-0.01 C/D were determined in this work for 1000-eV to 400-eV deuterium ions incident on a-C:H films. (orig.)

  9. Permeation of deuterium implanted into V-15Cr-5Ti

    Science.gov (United States)

    Anderl, R. A.; Longhurst, G. R.; Struttmann, D. A.

    1987-02-01

    Permeation and reemission of deuterium for the vanadium alloy, V-15Cr-5Ti, was investigated using 3 keV, D 3+ ion beams from a small accelerator. The experiments consisted of measurement of the deuterium reemission and permeation rates as a function of implantation fluence for 0.5 mm thick specimens heated to temperatures from 623 K to 823 K. Implantation-side surface characterization was made by simultaneous measurements of sputtered ions with a secondary ion mass spectrometer (SIMS). For the experimental conditions used, the steady-state deuterium permeation flux in V-15Cr-5Ti is approximately 18% of the implantation flux. This is approximately 1000 times that seen in the austenitic stainless steel, PCA, and 200 times that seen in the ferritic steel, HT-9, under comparable conditions. Measurement of deuterium diffusivity in V-15Cr-5Ti using permeation break-through times indicates that D = 1.4 × 10 -8 exp( -0.11 eV/ kT) (m 2/s), over the temperature range 723 K to 823 K.

  10. Hydrogen ion-driven permeation in carbonaceous films

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; Holland, D.F.; Longhurst, G.R.

    1989-04-01

    This paper presents the results of investigations into the permeation properties of amorphous carbonaceous, a-C:H, films produced by plasmachemical deposition techniques. Carbonaceous films on iron substrates with thickness ranging from 60 nm to 110 nm were subjected to high fluence implantations with mass analyzed D/sub 3//sup +/ ions with energies ranging from 600 eV to 3000 eV and fluxes ranging from 5x10/sup 14/ D/cm/sup 2/ s to 5x10/sup 15/ D/cm/sup 2/ s, respectively. Deuterium re-emission upstream, deuterium permeation downstream and secondary ions sputtered from the implantation surface were measured as a function of implantation fluence for specimens at 420 K. The present studies indicate that the a-C:H film permeability is directly related to the time, hence the fluence, required to achieve isotopic replacement and saturation of the deuterium ion beam atoms stopped in the implant region. Once the deuterium saturation level is achieved in the layer, a significant fraction of the implanting ions can result in permeation. For the present experiment, this permeation factor was much higher than that for uncoated iron specimens subjected to similar beam conditions. Carbon sputter yields of 0.008-0.01 C/D were determined in this work for 1000-eV to 400-eV deuterium ions incident on a-C:H films. (orig.).

  11. Hydrogen ion-driven permeation in carbonaceous films

    Science.gov (United States)

    Anderl, R. A.; Holland, D. F.; Longhurst, G. R.

    1989-04-01

    This paper presents the results of investigations into the permeation properties of amorphous carbonaceous, a-C: H, films produced by plasmachemical deposition techniques. Carbonaceous films on iron substrates with thickness ranging from 60 nm to 110 nm were subjected to high fluence implantations with mass analyzed D +3 ions with energies ranging from 600 eV to 3000 eV and fluxes ranging from 5 × 10 14D/ cm2 s to 5 × 10 15D/ cm2 s, respectively. Deuterium re-emission upstream, deuterium permeation downstream and secondary ions sputtered from the implantation surface were measured as a function of implantation fluence for specimens at 420 K. The present studies indicate that the a-C : H film permeability is directly related to the time, hence the fluence, required to achieve isotopic replacement and saturation of the deuterium ion beam atoms stopped in the implant region. Once the deuterium saturation level is achieved in the layer, a significant fraction of the implanting ions can result in permeation. For the present experiment, this permeation factor was much higher than that for uncoated iron specimens subjected to similar beam conditions. Carbon sputter yields of 0.008-0.01 C/D were determined in this work for 1000-eV to 400-eV deuterium ions incident on a-C : H films.

  12. Permeation of deuterium implanted into V-15Cr-5Ti

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; Longhurst, G.R.; Struttmann, D.A.

    1987-02-01

    Permeation and reemission of deuterium for the vanadium alloy, V-15Cr-5Ti, was investigated using 3 keV, D/sub 3//sup +/ ion beams from a small accelerator. The experiments consisted of measurement of the deuterium reemission and permeation rates as a function of implantation fluence for 0.5 mm thick specimens heated to temperatures from 623 K to 823 K. Implantation-side surface characterization was made by simultaneous measurements of sputtered ions with a secondary ion mass spectrometer (SIMS). For the experimental conditions used, the steady-state deuterium permeation flux in V-15Cr-5Ti is approximately 18% of the implantation flux. This is approximately 1000 times that seen in the austenitic stainless steel, PCA, and 200 times that seen in the ferritic steel, HT-9, under comparable conditions. Measurement of deuterium diffusivity in V-15Cr-5Ti using permeation break-through times indicates that D = 1.4x10/sup -8/ exp(-0.11 eVkT)(m/sup 2/s), over the temperature range 723 K to 823 K.

  13. In vitro-in vivo correlation in skin permeation.

    Science.gov (United States)

    Mohammed, D; Matts, P J; Hadgraft, J; Lane, M E

    2014-02-01

    In vitro skin permeation studies have been used extensively in the development and optimisation of delivery of actives in vivo. However, there are few reported correlations of such in vitro studies with in vivo data. The aim of this study was to investigate the skin permeation of a model active, niacinamide, both in vitro and in vivo. Conventional diffusion cell studies were conducted in human skin to determine niacinamide permeation from a range of vehicles which included dimethyl isosorbide (DMI), propylene glycol (PG), propylene glycol monolaurate (PGML), N-methyl 2-pyrrolidone (NMP), Miglyol 812N® (MG), and mineral oil (MO). Single, binary or ternary systems were examined. The same vehicles were subsequently examined to investigate niacinamide delivery in vivo. For this proof-of-concept study one donor was used for the in vitro studies and one volunteer for the in vivo investigations to minimise biovariability. Analysis of in vitro samples was conducted using HPLC and in vivo uptake of niacinamide was evaluated using Confocal Raman spectroscopy (CRS). The amount of niacinamide permeated through skin in vitro was linearly proportional to the intensity of the niacinamide signal determined in the stratum corneum in vivo. A good correlation was observed between the signal intensities of selected vehicles and niacinamide signal intensity. The findings provide further support for the use of CRS to monitor drug delivery into and across the skin. In addition, the results highlight the critical role of the vehicle and its disposition in skin for effective dermal delivery.

  14. Mechanisms of oxygen permeation through plastic films and barrier coatings

    Science.gov (United States)

    Wilski, Stefan; Wipperfürth, Jens; Jaritz, Montgomery; Kirchheim, Dennis; Mitschker, Felix; Awakowicz, Peter; Dahlmann, Rainer; Hopmann, Christian

    2017-10-01

    Oxygen and water vapour permeation through plastic films in food packaging or other applications with high demands on permeation are prevented by inorganic barrier films. Most of the permeation occurs through small defects (visualized by etching with reactive oxygen in a capacitively coupled plasma and subsequent SEM imaging. In this work, defects in SiO x -coatings deposited by plasma-enhanced chemical vapour deposition on polyethylene terephthalate (PET) are investigated and the mass transport through the polymer is simulated in a 3D approach. Calculations of single defects showed that there is no linear correlation between the defect area and the resulting permeability. The influence of adjacent defects in different distances was observed and led to flow reduction functions depending on the defect spacing and defect area. A critical defect spacing where no interaction between defects occurs was found and compared to other findings. According to the superposition principle, the permeability of single defects was added up and compared to experimentally determined oxygen permeation. The results showed the same trend of decreasing permeability with decreasing defect densities.

  15. The formation of hydrogen permeation barriers on steels by aluminising

    Science.gov (United States)

    Forcey, K. S.; Ross, D. K.; Wu, C. H.

    1991-06-01

    An extensive investigation has been carried out into the effectiveness of aluminised layers as permeation barriers on AISI 316L stainless and DIN 1.4914 martensitic steels. The study involved measurement of the hydrogen permeation rate through commercially aluminised steel discs of thicknesses in the range 1-1.6 mm, at temperatures between 250 and 600 °C and for an upstream hydrogen pressure of 10 5 Pa. The composition and structure of the aluminide layers were investigated by a number of techniques such as SEM, electron beam microprobe and X-ray diffraction. Accelerator based techniques such as RBS and NRA were employed to study the top micron or so of the surfaces of the samples. By these techniques it was found that the effectiveness of the permeation barrier depended on the formation of a thin surface oxide layer consisting of Al 2O 3. It was found that the permeation rate through the aluminised steels could be reduced by 3-4 orders of magnitude by forming a surface oxide layer up to a micron or so in thickness.

  16. Hydrogen permeation behavior through F82H at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, S.; Katayama, K.; Shimozori, M.; Fukada, S. [Interdisciplinary Graduate School of Engineering Science, Kyushu University, Kyushu (Japan); Ushida, H. [Energy Science and Engineering, Faculty of Engineering, Kyushu University, Kyushu (Japan); Nishikawa, M. [Malaysia-Japan International Institute of Technology, UTM, Kuala Lumpur (Malaysia)

    2015-03-15

    F82H is a primary candidate of structural material and coolant pipe material in a blanket of a fusion reactor. Understanding tritium permeation behavior through F82H is important. In a normal operation of a fusion reactor, the temperature of F82H will be controlled below 550 C. degrees because it is considered that F82H can be used up to 30,000 hours at 550 C. degrees. However, it is necessary to assume the situation where F82H is heated over 550 C. degrees in a severe accident. In this study, hydrogen permeation behavior through F82H was investigated in the temperature range from 500 to 800 C. degrees. In some cases, water vapor was added in a sample gas to investigate an effect of water vapor on hydrogen permeation. The permeability of hydrogen in the temperature range from 500 to 700 C. degrees agreed well with the permeability reported by E. Serra et al. The degradation of the permeability by water vapor was not observed. After the hydrogen permeation reached in a steady state at 700 C. degrees, the F82H sample was heated to 800 C. degrees. The permeability of hydrogen through F82H sample which was once heated up to 800 C. degrees was lower than that of the original one. (authors)

  17. GAS PERMEATION PROPERTIES OF POLY(LACTIC ACID). (R826733)

    Science.gov (United States)

    AbstractThe need for the development of polymeric materials based on renewable resources has led to the development of poly(lactic acid) (PLA) which is being produced from a feedstock of corn rather than petroleum. The present study examines the permeation of nitrogen...

  18. Phase Change Permeation Technology For Environmental Control Life Support Systems

    Science.gov (United States)

    Wheeler, Raymond M.

    2014-01-01

    Use of a phase change permeation membrane (Dutyion [Trademark]) to passively and selectively mobilize water in microgravity to enable improved water recovery from urine/brine for Environment Control and Life Support Systems (ECLSS) and water delivery to plans for potential use in microgravity.

  19. In vitro permeation of platinum through African and Caucasian skin.

    Science.gov (United States)

    Franken, A; Eloff, F C; du Plessis, J; Badenhorst, C J; Du Plessis, J L

    2015-02-03

    The majority of the South African workforce are Africans, therefore potential racial differences should be considered in risk and exposure assessments in the workplace. Literature suggests African skin to be a superior barrier against permeation and irritants. Previous in vitro studies on metals only included skin from Caucasian donors, whereas this study compared the permeation of platinum through African and Caucasian skin. A donor solution of 0.3 mg/ml of potassium tetrachloroplatinate (K₂PtCl₄) dissolved in synthetic sweat was applied to the vertical Franz diffusion cells with full thickness abdominal skin. Skin from three female African and three female Caucasian donors were included (n=21). The receptor solution was removed at various intervals during the 24 h experiment, and analysed with high resolution inductively coupled plasma-mass spectrometry (ICP-MS). Skin was digested and analysed by inductively coupled plasma-optical emission spectrometry (ICP-OES). Significantly higher permeation of platinum through intact African skin (p=0.044), as well as a significantly higher mass of platinum retention in African skin in comparison with Caucasian skin (p=0.002) occurred. Significant inter-donor variation was found in both racial groups (pskin and further investigation is necessary to explain the higher permeation through African skin. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Permeation of supercritical carbon dioxide through polymeric hollow fiber membranes

    NARCIS (Netherlands)

    Patil, V.E.; Broeke, van den L.J.P.; Vercauteren, F.F.; Keurentjes, J.T.F.

    2006-01-01

    Permeation of carbon dioxide was measured for two types of composite polymeric hollow fiber membranes for feed pressures up to 18 MPa at a temp. of 313 K. support membrane. The membranes consist of a polyamide copolymer (IPC) layer or a poly(vinyl alc.) (PVA) layer on top of a polyethersulfone

  1. Mechanisms of oxygen permeation through plastic films and barrier coatings

    International Nuclear Information System (INIS)

    Wilski, Stefan; Wipperfürth, Jens; Jaritz, Montgomery; Kirchheim, Dennis; Dahlmann, Rainer; Hopmann, Christian; Mitschker, Felix; Awakowicz, Peter

    2017-01-01

    Oxygen and water vapour permeation through plastic films in food packaging or other applications with high demands on permeation are prevented by inorganic barrier films. Most of the permeation occurs through small defects (<3 µ m) in the barrier coating. The defects were visualized by etching with reactive oxygen in a capacitively coupled plasma and subsequent SEM imaging. In this work, defects in SiO x -coatings deposited by plasma-enhanced chemical vapour deposition on polyethylene terephthalate (PET) are investigated and the mass transport through the polymer is simulated in a 3D approach. Calculations of single defects showed that there is no linear correlation between the defect area and the resulting permeability. The influence of adjacent defects in different distances was observed and led to flow reduction functions depending on the defect spacing and defect area. A critical defect spacing where no interaction between defects occurs was found and compared to other findings. According to the superposition principle, the permeability of single defects was added up and compared to experimentally determined oxygen permeation. The results showed the same trend of decreasing permeability with decreasing defect densities. (paper)

  2. Preventing method and device for underground permeation of hazardous material

    International Nuclear Information System (INIS)

    Funabashi, Kiyomi; Kurokawa, Hideaki; Fukazawa, Tetsuo; Yamazaki, Tadashi.

    1996-01-01

    In a method of preventing hazardous materials from permeating into ground by burying adsorbing materials underground, a plurality of adsorbing layers are laminated being spaced apart from each other, the concentration of the hazardous materials between each of the adsorbent layers is measured. When the concentration reaches a predetermined value, the adsorbent layers are regenerated. A suppression means for preventing hazardous materials from permeating into the ground are formed by an upper adsorbent layer and a lower adsorbent layer, and a means for measuring the concentration of hazardous materials passing through the upper adsorbent layer and a means for charging and discharging regenerated liquid are disposed. When it is detected that the poisonous materials can not be eliminated, the poisonous materials are already permeated to the adsorbent layer, and they start to inflow into underground water. In order to prevent it, an adsorbent layer is additionally disposed at the lower side of the place of detection to eliminate the poisonous materials completely thereby enabling to prevent poisonous materials from permeating into underground for a long period of time. (T.M.)

  3. Permeation of Mixed Penetrants through Glassy Polymer Membranes.

    Science.gov (United States)

    1985-03-15

    and LOPE. Also, ESCA was used in conjunction with plasma etching to determine the effects of the gas phase fluorine concentration and fluorination...at 35 3C. ARD-AISS5 65 PERMEATION OF MIXED PENETRANTS THROUGH GLASSY POLYMER 213 MENBRANES (U) NORTH CAROLINA STATE UNIV AT RALEIGH R T CHERN ET AL. 15

  4. Comparing pervaporation and vapor permeation hybrid distillation processes

    NARCIS (Netherlands)

    Fontalvo, J.; Cuellar, P.; Timmer, J.M.K.; Vorstman, M.A.G.; Wijers, J.G.; Keurentjes, J.T.F.

    2005-01-01

    Previous studies have shown that hybrid distillation processes using either pervaporation or vapor permeation can be very attractive for the separation of mixtures. In this paper, a comparison between these two hybrid processes has been made. A tool has been presented that can assist designers and

  5. Permeated defect detecting test method and device in reactor

    International Nuclear Information System (INIS)

    Sakurai, Yoshishige.

    1996-01-01

    The present invention provides a method of and a device capable of performing a test for entire inner surfaces of the reactor upon periodical inspection of a BWR type reactor while sufficiently taking countermeasures for radiation rays into consideration. Namely, the present invention comprises following steps. (1) A provisional step for taking a shroud head of a reactor core shroud and incore structural components above and below the shroud out of the reactor, discharging reactor water and water tightly closing openings such as reactor wall perforation holes, (2) a pretreatment step for washing exposed inner surfaces of the reactor and peeling deteriorated materials, (3) a first drying step for drying portions washed and peeled in the step (2), (4) a permeation step for applying a permeation liquid of a defect detecting medium on the exposed inner surfaces of the reactor, (5) a permeation liquid removing step for removing the an excess permeation liquid in the step (4), (6) a second drying step for drying corresponding portions after performing the step (5), and (7) a flaw detecting step for optically observing the corresponding portions after performing the step (6) and detecting flaws. (I.S.)

  6. In vitro permeation of platinum and rhodium through Caucasian skin.

    Science.gov (United States)

    Franken, A; Eloff, F C; Du Plessis, J; Badenhorst, C J; Jordaan, A; Du Plessis, J L

    2014-12-01

    During platinum group metals (PGMs) refining the possibility exists for dermal exposure to PGM salts. The dermal route has been questioned as an alternative route of exposure that could contribute to employee sensitisation, even though literature has been focused on respiratory exposure. This study aimed to investigate the in vitro permeation of platinum and rhodium through intact Caucasian skin. A donor solution of 0.3mg/ml of metal, K2PtCl4 and RhCl3 respectively, was applied to the vertical Franz diffusion cells with full thickness abdominal skin. The receptor solution was removed at various intervals during the 24h experiment, and analysed with high resolution ICP-MS. Skin was digested and analysed by ICP-OES. Results indicated cumulative permeation with prolonged exposure, with a significantly higher mass of platinum permeating after 24h when compared to rhodium. The mass of platinum retained inside the skin and the flux of platinum across the skin was significantly higher than that of rhodium. Permeated and skin retained platinum and rhodium may therefore contribute to sensitisation and indicates a health risk associated with dermal exposure in the workplace. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Effect of piperidones on hydrogen permeation and corrosion ...

    Indian Academy of Sciences (India)

    corrosion inhibition. 3.5 Hydrogen permeation measurements. Hydrogen can enter into the metal during various industrial operations like melting, heat treatment, or pickling and electrochemical processes such as cathodic cleaning and electrolytic machining. Of the various sources of entry of hydrogen into the metal,.

  8. Assessment of permeation of lipoproteins in human carotid tissue

    Science.gov (United States)

    Ghosn, Mohamad G.; Syed, Saba H.; Leba, Michael; Morrisett, Joel D.; Tuchin, Valery V.; Larin, Kirill V.

    2010-02-01

    Cardiovascular disease is among the leading causes of death in the United States. Specifically, atherosclerosis is an increasingly devastating contributor to the tally and has been found to be a byproduct of arterial permeability irregularities in regards to lipoprotein penetration. To further explore arterial physiology and molecular transport, the imaging technique of Optical Coherence Tomography (OCT) was employed. With OCT, the permeation of glucose (MW = 180 Da), low density lipoprotein (LDL; MW = 2.1 × 106 Da), and high density lipoprotein (HDL; MW = 2.5 × 105 Da) in human carotid tissue was studied to determine the effect of different molecular characteristics on permeation in atherosclerotic tissues. The permeability rates calculated from the diffusion of the molecular agents into the abnormal carotid tissue samples is compared to those of normal, healthy tissue. The results show that in the abnormal tissue, the permeation of agents correlate to the size constraints. The larger molecules of LDL diffuse the slowest, while the smallest molecules of glucose diffuse the fastest. However, in normal tissue, LDL permeates at a faster rate than the other two agents, implying the existence of a transport mechanism that facilitates the passage of LDL molecules. These results highlight the capability of OCT as a sensitive and specific imaging technique as well as provide significant information to the understanding of atherosclerosis and its effect on tissue properties.

  9. New experimental set-up and procedure for analyzing the dynamics of permeation of H2(g) across Pd-based metallic membranes

    International Nuclear Information System (INIS)

    Decaux, C.; Millet, P.; Decaux, C.

    2006-01-01

    Hydrogen permeation through metallic membranes is an industrial process used for purification purposes. Palladium-based alloys are generally used as permeation materials at operating temperatures above the critical value so that the metal-H system remains monophasic and that diffusion proceeds at sufficient rate. In state of the art systems, metallic membranes with typical thickness of a few tens of microns are used and rate limitation are generally attributed to atomic H transport by diffusion. Because of cost considerations, it is necessary to reduce the thickness of these membranes. In the micron thick range, surface contributions are expected to become rate determining, or at least to play an increasing role. Further, when the membrane is used on the exit side of a gas reformer to directly extract hydrogen, corrosion problems are expected to occur on the upstream side of the membrane. For all these reasons, there is a need to separately measure surface and bulk (diffusion) rate contributions to the overall permeation flux. A new experimental equipment has been specifically designed for this purpose. This setup can be operated in two different modes: for sorption or permeation experiments. In a typical sorption experiment, the metallic membrane is disposed in the reaction chamber and hydrogen is allowed to react from both side of the surface. This procedure allows the separate measurement of surface absorption and desorption resistances associated with the chemisorption step. In a typical permeation experiment, the membrane is mounted between two volume chambers, a pressurized hydrogen source reservoir and an empty sink reservoir. Initially, a difference of pressure is set between the two reservoirs. When the valve of the source tank is opened, H 2 (g) flows to the membrane and permeation proceeds until pressure reaches an equilibrium value. In both experimental configurations, gas pressure transients are synchronously sampled all along the experiment

  10. Development of a plasma driven permeation experiment for TPE

    Energy Technology Data Exchange (ETDEWEB)

    Buchenauer, Dean, E-mail: dabuche@sandia.gov [Sandia National Laboratories, Livermore, CA (United States); Kolasinski, Robert [Sandia National Laboratories, Livermore, CA (United States); Shimada, Masa [Idaho National Laboratory, Idaho Falls, ID (United States); Donovan, David [Sandia National Laboratories, Livermore, CA (United States); Youchison, Dennis [Sandia National Laboratories, Albuquerque, NM (United States); Merrill, Brad [Idaho National Laboratory, Idaho Falls, ID (United States)

    2014-10-15

    Highlights: • We have designed and fabricated a novel tritium permeation membrane holder for use in the Tritium Plasma Experiment (TPE). • The membrane temperature is controlled by varying the cooling flow rate and proximity of a spiral cooling channel. • Sealing tests have demonstrated adequate helium leak rates up to temperatures of 1000 °C. • Flow modeling indicates a minimal helium pressure drop across the membrane holder (<700 Pa). • Thermal modeling shows good heat removal and minimal membrane temperature variation (±2%) even up to peak TPE ion fluxes. - Abstract: Experiments on retention of hydrogen isotopes (including tritium) at temperatures less than 800 °C have been carried out in the Tritium Plasma Experiment (TPE) at Idaho National Laboratory [1,2]. To provide a direct measurement of plasma driven permeation in plasma facing materials at temperatures reaching 1000 °C, a new TPE membrane holder has been built to hold test specimens (≤1 mm in thickness) at high temperature while measuring tritium permeating through the membrane from the plasma facing side. This measurement is accomplished by employing a carrier gas that transports the permeating tritium from the backside of the membrane to ion chambers giving a direct measurement of the plasma driven tritium permeation rate. Isolation of the membrane cooling and sweep gases from TPE's vacuum chamber has been demonstrated by sealing tests performed up to 1000 °C of a membrane holder design that provides easy change out of membrane specimens between tests. Simulations of the helium carrier gas which transports tritium to the ion chamber indicate a very small pressure drop (∼700 Pa) with good flow uniformity (at 1000 sccm). Thermal transport simulations indicate that temperatures up to 1000 °C are expected at the highest TPE fluxes.

  11. In Vitro Skin Permeation Enhancement of Sumatriptan by Microneedle Application.

    Science.gov (United States)

    Nalluri, Buchi N; Anusha, Sai Sri V; Bramhini, Sri R; Amulya, J; Sultana, Ashraf S K; Teja, Chandra U; Das, Diganta B

    2015-01-01

    Different dimensions of commercially available microneedle devices, namely, Admin- Patch(®) microneedle arrays (MN) (0.6, 0.9, 1.2 and 1.5 mm lengths) and Dermaroller(®) microneedle rollers (DR) (0.5 and 1mm lengths) were evaluated for their relative efficiency in enhancement of transdermal permeation of Sumatriptan (SMT). Solubility assessment of SMT was carried out using propylene glycol (PG), polyethylene glycol (PEG) in combination with saline (S) at different ratios and the order of solubility was found to be 70:30 > 80:20 > 90:10 %v/v in both PG:S and PEG:S. In vitro skin permeation studies were performed using PG:S (70:30 %v/v) as donor vehicle. A significant increase in cumulative amount of SMT permeated, steady state flux, permeability coefficient and diffusion coefficient values were observed after microneedle treatment, and the values were in the order of 1.5mm MN >1.2mm MN >0.9mm MN >1mm DR >0.6mm MN >0.5mm DR > passive permeation. Lag times were significantly shorter after longer microneedle application (0.24h for 1.5mm MN). Arrays were found to be superior to rollers with similar microneedle lengths in enhancing SMT permeation and may be attributed to higher density of microneedles and force of application onto skin. The in vitro flux values revealed that 2.5cm(2) area patch is sufficient for effective therapy after treatment of skin with 1.5mm MN. It may be inferred that microneedle application significantly enhances the transdermal penetration of SMT and that it may be feasible to deliver clinically relevant therapeutic levels of SMT using microneedle assisted transdermal delivery systems.

  12. Development of a plasma driven permeation experiment for TPE

    International Nuclear Information System (INIS)

    Buchenauer, Dean; Kolasinski, Robert; Shimada, Masa; Donovan, David; Youchison, Dennis; Merrill, Brad

    2014-01-01

    Highlights: • We have designed and fabricated a novel tritium permeation membrane holder for use in the Tritium Plasma Experiment (TPE). • The membrane temperature is controlled by varying the cooling flow rate and proximity of a spiral cooling channel. • Sealing tests have demonstrated adequate helium leak rates up to temperatures of 1000 °C. • Flow modeling indicates a minimal helium pressure drop across the membrane holder (<700 Pa). • Thermal modeling shows good heat removal and minimal membrane temperature variation (±2%) even up to peak TPE ion fluxes. - Abstract: Experiments on retention of hydrogen isotopes (including tritium) at temperatures less than 800 °C have been carried out in the Tritium Plasma Experiment (TPE) at Idaho National Laboratory [1,2]. To provide a direct measurement of plasma driven permeation in plasma facing materials at temperatures reaching 1000 °C, a new TPE membrane holder has been built to hold test specimens (≤1 mm in thickness) at high temperature while measuring tritium permeating through the membrane from the plasma facing side. This measurement is accomplished by employing a carrier gas that transports the permeating tritium from the backside of the membrane to ion chambers giving a direct measurement of the plasma driven tritium permeation rate. Isolation of the membrane cooling and sweep gases from TPE's vacuum chamber has been demonstrated by sealing tests performed up to 1000 °C of a membrane holder design that provides easy change out of membrane specimens between tests. Simulations of the helium carrier gas which transports tritium to the ion chamber indicate a very small pressure drop (∼700 Pa) with good flow uniformity (at 1000 sccm). Thermal transport simulations indicate that temperatures up to 1000 °C are expected at the highest TPE fluxes

  13. Towards a unified model of passive drug permeation I: origins of the unstirred water layer with applications to ionic permeation.

    Science.gov (United States)

    Ghosh, Avijit; Scott, Dennis O; Maurer, Tristan S

    2014-02-14

    In this work, we provide a unified theoretical framework describing how drug molecules can permeate across membranes in neutral and ionized forms for unstirred in vitro systems. The analysis provides a self-consistent basis for the origin of the unstirred water layer (UWL) within the Nernst-Planck framework in the fully unstirred limit and further provides an accounting mechanism based simply on the bulk aqueous solvent diffusion constant of the drug molecule. Our framework makes no new assumptions about the underlying physics of molecular permeation. We hold simply that Nernst-Planck is a reasonable approximation at low concentrations and all physical systems must conserve mass. The applicability of the derived framework has been examined both with respect to the effect of stirring and externally applied voltages to measured permeability. The analysis contains data for 9 compounds extracted from the literature representing a range of permeabilities and aqueous diffusion coefficients. Applicability with respect to ionized permeation is examined using literature data for the permanently charged cation, crystal violet, providing a basis for the underlying mechanism for ionized drug permeation for this molecule as being due to mobile counter-current flow. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Computational investigation of the effects of barrier layers on the permeation of hydrogen through metals

    International Nuclear Information System (INIS)

    Perkins, W.G.

    1975-01-01

    Results of a computational investigation of the permeation behavior of oxide-coated metal membranes are presented. A steady-state permeation model was developed which promises to be useful in evaluation of oxide layers on metals as hydrogen permeation barriers. The pressure and thickness dependence of steady state permeation through oxide-coated metal membranes is described using plots of logarithmic functions. (U.S.)

  15. Measurement of Skin Permeation/Penetration of Nanoparticles for Their Safety Evaluation

    OpenAIRE

    木村, 恵理子; 河野, 雄一郎; 藤堂, 浩明; 五十嵐, 良明; 杉林, 堅次

    2012-01-01

    The aim of the present study was to quantitatively evaluate the skin permeation/penetration of nanomaterials and to consider their penetration pathway through skin. Firstly, penetration/permeation of a model fluorescent nanoparticle, Fluoresbrite?, was determined through intact rat skin and several damaged skins. Fluoresbrite? permeated through only needle-punctured skin. The permeation profiles of soluble high molecular compounds, fluorescein isothiocyanate-dextrans (FITC-dextrans, FDs), wit...

  16. 40 CFR 1060.521 - How do I test fuel caps for permeation emissions?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false How do I test fuel caps for permeation... EQUIPMENT Test Procedures § 1060.521 How do I test fuel caps for permeation emissions? If you measure a fuel tank's permeation emissions with a nonpermeable covering in place of the fuel cap under § 1060.520(b)(5...

  17. Counter-diffusion and -permeation of deuterium and hydrogen through metals

    Energy Technology Data Exchange (ETDEWEB)

    Kizu, Kaname; Tanabe,; Tetsuo, [Nagoya Univ. (Japan)

    1998-03-01

    The first experiments for counter-diffusion and -permeation of deuterium and hydrogen through palladium were performed. Deuterium permeation rates against D{sub 2} pressure were measured under the condition where hydrogen permeated to opposite direction by supplying H{sub 2} gas at the permeated side of D{sub 2}. It was found that not a small amount of deuterium was clearly permeated even if the deuterium pressure was much smaller than the hydrogen pressure. Deuterium permeation rate was gradually reduced by increasing the counter H permeation. The deuterium permeation rate under the counter H permeation is well represented by a simple model in which the ratio of the deuterium permeation rates with and without the counter H permeation was proportional to the fractional concentration of deuterium in the bulk. As increasing the hydrogen counter flow, however, the deuterium permeation rate deviates from the model. This means that adsorption (absorption) of D{sub 2} from gas phase is inhibited and surface recombination of deuterium is blocked by hydrogen. (author)

  18. Multi-Dielectric Brownian Dynamics and Design-Space-Exploration Studies of Permeation in Ion Channels.

    Science.gov (United States)

    Siksik, May; Krishnamurthy, Vikram

    2017-09-01

    This paper proposes a multi-dielectric Brownian dynamics simulation framework for design-space-exploration (DSE) studies of ion-channel permeation. The goal of such DSE studies is to estimate the channel modeling-parameters that minimize the mean-squared error between the simulated and expected "permeation characteristics." To address this computational challenge, we use a methodology based on statistical inference that utilizes the knowledge of channel structure to prune the design space. We demonstrate the proposed framework and DSE methodology using a case study based on the KcsA ion channel, in which the design space is successfully reduced from a 6-D space to a 2-D space. Our results show that the channel dielectric map computed using the framework matches with that computed directly using molecular dynamics with an error of 7%. Finally, the scalability and resolution of the model used are explored, and it is shown that the memory requirements needed for DSE remain constant as the number of parameters (degree of heterogeneity) increases.

  19. Corrosion behaviour of Al based tritium permeation barriers in flowing Pb-17Li

    International Nuclear Information System (INIS)

    Glasbrenner, H.; Konys, J.; Voss, Z.; Wedemeyer, O.

    2002-01-01

    Tritium permeation barriers on low-activation steels are required in fusion technology in order to reduce the tritium permeation rate through the structural material into the cooling water system. Al-Fe layers with alumina on top can fulfil the required reduction rate. Three techniques were selected to produce such a multi-layered coating system: chemical vapour deposition (CVD) by CEA, hot-dip aluminising (HDA) by FZK and vacuum plasma spraying (VPS) by JRC Ispra. A sufficient corrosion resistance against Pb-17Li attack is also required for the coating. Therefore, the corrosion behaviour of these three coatings on ferritic-martensitic steels was studied in the PICOLO loop of FZK in flowing Pb-17Li at 480 deg. C up to 10 000 h. Corrosion effects could not be found on HDA and VPS coated specimens even up to the longest time of exposure. The total thickness of the two-layered system remained unchanged at around 130 μm for all examined HDA and VPS specimens. In contrast to this, corrosion effects could be inspected on CVD coated specimens

  20. Exercise and physical training improve physical function in older adults with visual impairments but their effect on falls is unclear: a systematic review

    Directory of Open Access Journals (Sweden)

    Michael Gleeson

    2014-09-01

    [Gleeson M, Sherrington C, Keay L (2014 Exercise and physical training improve physical function in older adults with visual impairments but their effect on falls is unclear: a systematic review. Journal of Physiotherapy 60: 130–135

  1. Study on low temperature plasma driven permeation of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Takizawa, Masayuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    It is one of the most important problem in PWI of fusion devices from the point of view of tritium leakage that hydrogen diffuses in the wall of the device and permeates through it, which results in hydrogen being released to the coolant side. In this study, plasma driven permeation experiments were carried out with several kinds of metal membranes in the low temperature plasma where ionic and atomic hydrogen as well as electron existed in order to survey PDP mechanism from the many view points. In addition, incident flux rate from the plasma to the membrane surface was evaluated by calculation analysis. As a result the mechanism of low temperature PDP was found out and described as PDP models. The simulation of the membrane pump system was executed and the system performance was estimated with the models. (author). 135 refs.

  2. Gas Permeation Characteristics across Nano-Porous Inorganic Membranes

    Directory of Open Access Journals (Sweden)

    M.R Othman, H. Mukhtar

    2012-10-01

    Full Text Available An overview of parameters affecting gas permeation in inorganic membranes is presented. These factors include membrane physical characteristics, operational parameters and gas molecular characteristics. The membrane physical characteristics include membrane materials and surface area, porosity, pore size and pore size distribution and membrane morphology. The operational parameters include feed flow rate and concentration, stage cut, temperature and pressure. The gas molecular characteristics include gas molecular weight, diameter, critical temperature, critical pressure, Lennard-Jones parameters and diffusion volumes. The current techniques of material characterization may require complementary method in describing microscopic heterogeneity of the porous ceramic media. The method to be incorporated in the future will be to apply a stochastic model and/or fractal dimension. Keywords: Inorganic membrane, surface adsorption, Knudsen diffusion, Micro-porous membrane, permeation, gas separation.

  3. Intact penetratin metabolite permeates across Caco-2 monolayers

    DEFF Research Database (Denmark)

    Birch, Ditlev; Christensen, Malene Vinther; Stærk, Dan

    . Previous studies have demonstrated that cell-penetrating peptides (CPPs) may be used as carriers in order to improve the bioavailability of a therapeutic cargo like insulin after oral administration. Penetratin, a commonly used CPP, has been shown to increase the uptake of insulin across Caco-2 cell......-2 cells cultured on permeable filter inserts and in cell lysates, respectively. The epithelial permeation of penetratin and the formed metabolites was assessed by using Caco-2 monolayers cultured on permeable filter inserts. Results Preliminary data revealed that at least one specific metabolite...... is formed upon both intracellular and extracellular degradation of penetratin (figure 1A). Following incubation with epithelium for 4 hours, the metabolite permeated the Caco-2 monolayer and the concentration increased approximately 10-fold when compared to a sample collected following 15 minutes...

  4. Study on low temperature plasma driven permeation of hydrogen

    International Nuclear Information System (INIS)

    Takizawa, Masayuki

    1998-03-01

    It is one of the most important problem in PWI of fusion devices from the point of view of tritium leakage that hydrogen diffuses in the wall of the device and permeates through it, which results in hydrogen being released to the coolant side. In this study, plasma driven permeation experiments were carried out with several kinds of metal membranes in the low temperature plasma where ionic and atomic hydrogen as well as electron existed in order to survey PDP mechanism from the many view points. In addition, incident flux rate from the plasma to the membrane surface was evaluated by calculation analysis. As a result the mechanism of low temperature PDP was found out and described as PDP models. The simulation of the membrane pump system was executed and the system performance was estimated with the models. (author). 135 refs

  5. Tritium breeders and tritium permeation barrier coatings for fusion reactor

    International Nuclear Information System (INIS)

    Yamawaki, Michio; Kawamura, Hiroshi; Tsuchiya, Kunihiko

    2004-01-01

    A state of R and D of tritium breeders and tritium permeation barrier coatings for fusion reactor is explained. A list of candidate for tritium breeders consists of ceramics containing lithium, for examples, Li 2 O, Li 2 TiO 3 , Li 2 ZrO 3 , Li 4 SiO 4 and LiAlO 2 . The characteristics and form are described. The optimum particle size is from 1 to 10 μm. The production technologies of tritium breeders in the world are stated. Characteristics of ceramics with lithium as tritium breeders are compared. TiC, TiN/TiC, Al 2 O 3 and Cr 2 O 3 -SiO 2 -P 2 O 5 are tritium permeation barrier coating materials. These production methods and evaluation of characteristics are explained. (S.Y.)

  6. Structural and functional significance of water permeation through cotransporters

    DEFF Research Database (Denmark)

    Zeuthen, Thomas; Gorraitz, Edurne; Her, Ka

    2016-01-01

    Membrane transporters, in addition to their major role as specific carriers for ions and small molecules, can also behave as water channels. However, neither the location of the water pathway in the protein nor their functional importance is known. Here, we map the pathway for water and urea...... through the intestinal sodium/glucose cotransporter SGLT1. Molecular dynamics simulations using the atomic structure of the bacterial transporter vSGLT suggest that water permeates the same path as Na+ and sugar. On a structural model of SGLT1, based on the homology structure of vSGLT, we identified...... to be due to alterations in steric hindrance to water and urea, and/or changes in protein folding caused by mismatching of side chains in the water pathway. Water permeation through SGLT1 and other transporters bears directly on the structural mechanism for the transport of polar solutes through...

  7. Permeation barrier properties of thin oxide films on flexible polymer substrates

    International Nuclear Information System (INIS)

    Fahlteich, John; Fahland, Matthias; Schoenberger, Waldemar; Schiller, Nicolas

    2009-01-01

    Solar cells and organic electronic devices require an encapsulation to ensure sufficient lifetime. Key parameters of the encapsulation are permeation barrier, UV stability, temperature stability, optical transmission spectra and mechanical stability. The requirements depend very much on the specific application. Many work groups suggest multilayer stacks to meet the permeation requirements. In this paper the permeation barrier properties of the different constituents of such a multilayer stack are characterized. Different layer materials are compared regarding their water vapour and oxygen permeability as well as the influence of process parameters is examined. Finally temperature dependent permeation measurements are used to characterize the permeation mechanisms in the different constituents of the multilayer barrier

  8. Low-Volatility Agent Permeation (LVAP) Verification and Validation Report

    Science.gov (United States)

    2015-05-01

    custody procedures were obtained from the ISO / IEC 17025 :2005 standard13 as well as the current version of Permeation and Analytical Solutions Branch...Testing and Calibration Laboratories; ISO / IEC 17025 :2005; International Organization for Standardization: Geneva, Switzerland, 2005. 14. Box, G.E...ECBC, as detailed in Section 6.4.4 The International Organization for Standardization ( ISO ) method, 5725-3 (1994), was used to calculate the standard

  9. Assessment of permeation quality of concrete through mercury intrusion porosimetry

    International Nuclear Information System (INIS)

    Kumar, Rakesh; Bhattacharjee, B.

    2004-01-01

    Permeation quality of laboratory cast concrete beams was determined through initial surface absorption test (ISAT). The pore system characteristics of the same concrete beam specimens were determined through mercury intrusion porosimetry (MIP). Data so obtained on the measured initial surface absorption rate of water by concrete and characteristics of pore system of concrete estimated from porosimetry results were used to develop correlations between them. Through these correlations, potential of MIP in assessing the durability quality of concrete in actual structure is demonstrated

  10. Gas permeation process for post combustion CO2 capture

    International Nuclear Information System (INIS)

    Pfister, Marc

    2017-01-01

    CO 2 Capture and Storage (CCS) is a promising solution to separate CO 2 from flue gas, to reduce the CO 2 emissions in the atmosphere, and hence to reduce global warming. In CCS, one important constraint is the high additional energy requirement of the different capture processes. That statement is partly explained by the low CO 2 fraction in the inlet flue gas and the high output targets in terms of CO 2 capture and purity (≥90%). Gas permeation across dense membrane can be used in post combustion CO 2 capture. Gas permeation in a dense membrane is ruled by a mass transfer mechanism and separation performance in a dense membrane are characterized by component's effective permeability and selectivity. One of the newest and encouraging type of membrane in terms of separation performance is the facilitated transport membrane. Each particular type of membrane is defined by a specific mass transfer law. The most important difference to the mass transfer behavior in a dense membrane is related to the facilitated transport mechanism and the solution diffusion mechanism and its restrictions and limitations. Permeation flux modelling across a dense membrane is required to perform a post combustion CO 2 capture process simulation. A CO 2 gas permeation separation process is composed of a two-steps membrane process, one drying step and a compression unit. Simulation on the energy requirement and surface area of the different membrane modules in the global system are useful to determine the benefits of using dense membranes in a post combustion CO 2 capture technology. (author)

  11. Gas Permeation Processes in Biogas Upgrading: A Short Review

    Czech Academy of Sciences Publication Activity Database

    Kárászová, Magda; Sedláková, Zuzana; Izák, Pavel

    2015-01-01

    Roč. 69, č. 10 (2015), s. 1277-1283 ISSN 0366-6352 R&D Projects: GA MŠk(CZ) LD14094; GA MŠk LH14006; GA ČR GA14-12695S Institutional support: RVO:67985858 Keywords : biogas upgrading * memranes * gas permeation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.326, year: 2015

  12. Hydrogen diffusion, dissolution and permeation of nonmetallic solids

    International Nuclear Information System (INIS)

    Elleman, T.S.; Rao, D.; Verghese, K.; Zumwalt, L.

    1979-01-01

    A review of hydrogen diffusion, dissolution and permeation in metal oxides, carbides, nitrides, halides and hydrides is presented. Results are organized by compound and an effort has been made to resolve differences between measured results where wide disparities exist. The document has been prepared to provide needed data for the development of fusion reactor blankets but the results should be generally useful in technologies that involve interactions between hydrogen and non-metals

  13. Tritium inventory and permeation in liquid breeder blankets

    International Nuclear Information System (INIS)

    Reiter, F.

    1990-01-01

    This report reviews studies of the transport of hydrogen isotopes in the DEMO relevant water-cooled Pb-17Li blanket to be tested in NET and in a self-cooled blanket which uses Pb-17Li or Flibe as a liquid breeder material and V or Fe as a first wall material. The time dependences of tritium inventory and permeation in these blankets and of deuterium and tritium recycling in the self-cooled blanket are presented and discussed

  14. A novel lipid nanoemulsion system for improved permeation of granisetron.

    Science.gov (United States)

    Doh, Hea-Jeong; Jung, Yunjin; Balakrishnan, Prabagar; Cho, Hyun-Jong; Kim, Dae-Duk

    2013-01-01

    A new lipid nanoemulsion (LNE) system containing granisetron (GRN) was developed and its in vitro permeation-enhancing effect was evaluated using Caco-2 cell monolayers. Particle size, polydispersity index (PI) and stability of the prepared GRN-loaded LNE systems were also characterized. The mean diameters of prepared LNEs were around 50 nm with PI<0.2. Developed LNEs were stable at 4°C in the dark place over a period of 12 weeks. In vitro drug dissolution and cytotoxicity studies of GRN-loaded LNEs were performed. GRN-loaded LNEs exhibited significantly higher drug dissolution than GRN suspension at pH 6.8 for 2h (P<0.05). In vitro permeation study in Caco-2 cell monolayers showed that the LNEs significantly enhanced the drug permeation compared to GRN powder. The in vivo toxicity study in the rat jejunum revealed that the prepared GRN-loaded LNE was as safe as the commercial formulation (Kytril). These results suggest that LNE could be used as a potential oral liquid formulation of GRN for anti-emetic treatment on the post-operative and chemotherapeutic patients. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Skin penetration and tissue permeation after topical administration of diclofenac.

    Science.gov (United States)

    Hagen, Martina; Baker, Mark

    2017-09-01

    Topical delivery of drugs is an alternative to oral administration, often with similar efficacy but potentially a more favorable tolerability profile. However, topical formulations need to be able to penetrate the skin and permeate to the target areas in quantities sufficient to exert a therapeutic effect. Many factors can affect this process, including the physicochemical properties of the drug, the formulation used, and the site and mode of application. It is believed that measurement of drug concentrations at the sites of action may be an indicator of their likely efficacy. This review addresses these issues, with reference to topically administered diclofenac in osteoarthritis. Articles relevant to this review were identified after a systematic search of Medline and Embase, using the key words "diclofenac", "topical administration" and "osteoarthritis" in the search strategy. The sparse data available indicate that topical diclofenac can penetrate and permeate to deeper tissues, with a lower plasma to tissue ratio than oral diclofenac. The tissue diclofenac levels after topical delivery are sustained over time (at least several hours). However, there is not enough data to establish how diclofenac levels in the joint compare with IC 50 levels (50% of the maximum inhibition of prostaglandin synthesis) established following oral administration. After topical application, diclofenac can penetrate the skin and permeate to deeper tissues, where it reaches a concentration that appears to be sufficient to exert a therapeutic effect. More robust methods are required for in vivo characterization to better estimate the clinical efficacy of topically applied drugs.

  16. Studies on Tasar Cocoon Cooking Using Permeation Method

    Science.gov (United States)

    Javali, Uday C.; Malali, Kiran B.; Ramya, H. G.; Naik, Subhas V.; Padaki, Naveen V.

    2018-02-01

    Cocoon cooking is an important process before reeling of tasar silk yarn. Cooking ensures loosening of the filaments in the tasar cocoons thereby easing the process of yarn withdrawal during reeling process. Tasar cocoons have very hard shell and hence these cocoons need chemical cooking process to loosen the silk filaments. Attempt has been made in this article to study the effect of using vacuum permeation chamber for tasar cocoon cooking in order to reduce the cooking time and improve the quality of tasar silk yarn. Vacuum assisted permeation cooking method has been studied in this article on tasar daba cocoons for cooking efficiency, deflossing and reelability. Its efficiency has been evaluated with respect to different cooking methods viz, traditional and open pan cooking methods. The tasar silk produced after reeling process has been tested for fineness, strength and cohesion properties. Results indicate that permeation method of tasar cooking ensures uniform cooking with higher efficiency along with better reeling performance and improved yarn properties.

  17. Penetration of radionuclides across the skin. Rat age dependent promethium permeation through skin in vitro

    International Nuclear Information System (INIS)

    Kassai, Z.; Kassai, A.; Bauerova, K.; Koprda, V.; Harangozo, M.; Bendova, P.; Bujnova, A.

    2003-01-01

    The composition and the permeation properties of the skin are dependent on age. In the animal models for permation studies, age affects the mechanical as well as the permeation properties significantly. The time dependence of permeation of 147 Pm 3+ from aqueous solution was established by the animal skin model and the age dependence of promethium permeation through the skin was examined. The aim was to find the optimum rat skin age model for radionuclide permeation studies and to assess the relative importance of the main permeation pathways: transepidermal and transfollicular permeation. The skin from 5-day-old rats (5DR) was found to represent the optimum animal model to study transepidermal permeation of ions. The skin from 9-day-old rats (9DR) was selected to study transfollicular permeation of ions. Comparison of the permeated amounts of promethium through the skin without hairs (3 DR to 6 DR) and with hairs (7DR to 12DR) showed that the additional permation mode via follicles significantly contributed to the permeation rate and extent. (author)

  18. A 2D Finite Element Modelling of Tritium Permeation Through Cooling Plates for The HCLL DEMO Blanket Module

    International Nuclear Information System (INIS)

    Gabriel, F.; Escuriol, Y.; Dabbene, F.; Salavy, J.F.; Giancarli, L.; Gastaldi, O.

    2006-01-01

    As the Tritium self sufficiency is one of the major challenges for fusion reactor, breeding blankets represent one of the major technological breakthroughs required from passing from ITER to the next step reactor, usually called DEMO. One of the two blanket concepts developed in the EU is the Helium Cooled Lithium Lead (HCLL) blanket which uses the eutectic Pb-15.7Li metal liquid as both breeder and neutron multiplier. The structures, made of EUROFER, a low activation ferritic martensitic steel, are cooled by pressurized helium at 8 MPa and inlet/outlet temperature 300/500 o C. In this concept, the LiPb is fed from the top of the blanket and distributed in parallel vertical channels among pairs of cells (one cell for the radial movement towards the plasma, the other for the return). The liquid metal fills the in-box volume and is slowly re-circulated (few mm per seconds) to remove the produced tritium. In this paper, a local finite element modelling of the tritium permeation rate through the HCLL breeder unit cooling plates is presented. The tritium concentration in the helium circuit and remaining in the lithium lead circuit are evaluated by solving partial differential equations governing the tritium concentration balance, the thermal field and the lithium lead velocity field for a simplified 2D geometrical representation of the breeder unit. This allows estimating the sensitivity effect of coupling these different equations in order to deduce a relevant but simplified modelling for tritium permeation. This is to compare with tritium inventories studies, were the tritium permeation rate is estimated using simplified analytical modelling which generally leads to over estimate the tritium permeation rate to the coolant and so has strong influence on the coolant purification plant design. The finite element modelling performed shows that the Tritium permeation is considerable lower than the one obtained in previous estimations where nominal values of the governing

  19. Physics-Based Modeling of Permeation: Simulation of Low-Volatility Agent Permeation and Aerosol Vapor Liquid Assessment Group Experiments

    Science.gov (United States)

    2015-06-01

    methylphosphonothiolate (VX) through natural latex rubber and neoprene resulting from LVAP tests. 2. The permeation model is used to study the sensitivity of...Styrene–Butadiene– Rubber , Ethylene–Propylene–Diene Terpolymer, and Natural Rubber Versus Hydrocarbons (C8–C16). Macromolecules 1991, 24 (9), 2598–2605...22 14. Harogoppad, S.B.; Aminabhavi, T.M. Diffusion and Sorption of Organic Liquids through Polymer Membranes 2. Neoprene, SBR, EPDM, NBR , and

  20. Evaluation of peracetic acid permeation during flash sterilization through pharmaceutical plastic polymers used in cytotoxic reconstitution units.

    Science.gov (United States)

    Havard, Laurent; Fellous-Jerome, Joelle; Bonan, Brigitte; Pradeau, Dominique; Prognon, Patrice

    2005-01-01

    Peracetic acid (PAA) permeation in flash sterilization was studied using three different plastic infusion bags made of polypropylene and polyethylene, filled with glucose 5% or NaCl 0.9%. The pH was measured and acetic acid (AA) and PAA concentrations were made by reverse phase high-performance liquid chromatography (RP-HPLC). PAA was derivatized by oxidation of methyl tolyl sulfide (MTS) into methyl tolyl sulfoxide (MTSO) detected by ultraviolet (UV) absorbance at 230 nm. The technique has a sensitivity of 0.3 microg x L(-1) and was highly specific. Results showed that pH measurements remain constant and demonstrated the absence of PAA permeation, which was confirmed by the absence of AA permeation regardless of the brand tested, with both unwrapped and overwrapped infusion bags, when flash sterilization is applied. These results allow flash sterilization to be performed with unwrapped infusion bags without any risk of drug degradation by PAA. This makes compounding safer and easier, which improves productivity.

  1. Selection of sorption material for tests of pesticide permeation through protective clothing fabrics.

    Science.gov (United States)

    Krzemińska, Sylwia; Nazimek, Teresa

    2004-01-01

    The paper presents the results of studies on selecting a solid sorption material for absorbing liquid crop protection agents which permeate samples of protective clothing fabrics. The sorption materials were investigated and selected with an assumption that they should have a high recovery coefficient for biologically active substances, used as active ingredients in crop protection agents, at a presumed, acceptably high level. The selected substances were determined with a gas chromatograph equipped with an electron capture detector (dichlorvos, cypermethrin and 2,4-D) and a nitrogen-phosphorus detector (carbofuran). The tests demonstrated that polypropylene melt-blown type unwoven cloth had high recovery coefficients for all 4 active ingredients proposed for the study. The highest recovery coefficient, -.97, was obtained for carbofuran. The recovery coefficients obtained for the 3 remaining substances were lower: .89 for cypermethrin and 2,4-D, and .84 for dichlorvos.

  2. Measurement of skin permeation/penetration of nanoparticles for their safety evaluation.

    Science.gov (United States)

    Kimura, Eriko; Kawano, Yuichiro; Todo, Hiroaki; Ikarashi, Yoshiaki; Sugibayashi, Kenji

    2012-01-01

    The aim of the present study was to quantitatively evaluate the skin permeation/penetration of nanomaterials and to consider their penetration pathway through skin. Firstly, penetration/permeation of a model fluorescent nanoparticle, Fluoresbrite®, was determined through intact rat skin and several damaged skins. Fluoresbrite® permeated through only needle-punctured skin. The permeation profiles of soluble high molecular compounds, fluorescein isothiocyanate-dextrans (FITC-dextrans, FDs), with different molecular weights were also measured for comparison. The effects of molecular sizes and different skin pretreatments on the skin barrier were determined on the skin penetration/permeation of Fluoresbrite® and FDs. Fluoresbrite® was not permeated the intact skin, but FDs were permeated the skin. The skin distribution of titanium dioxide and zinc oxide nanoparticles was also observed after topical application of commercial cosmetics. Nanoparticles in sunscreen cosmetics were easily distributed into the groove and hair follicles after their topical application, but seldom migrated from the groove or follicles to viable epidermis and dermis. The obtained results suggested that nanoparticles did not permeate intact skin, but permeated pore-created skin. No or little permeation was observed for these nanomaterials through the stratum corneum.

  3. Tritium permeation characterization of Al{sub 2}O{sub 3}/FeAl coatings as tritium permeation barriers on 321 type stainless steel containers

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Feilong; Xiang, Xin; Lu, Guangda; Zhang, Guikai, E-mail: zhangguikai@caep.cn; Tang, Tao; Shi, Yan; Wang, Xiaolin

    2016-09-15

    Accurate tritium transport properties of prospective tritium permeation barriers (TPBs) are essential to tritium systems in fusion reactors. By passing a temperature and rate-controlled sweeping gas over specimen surfaces to carry the permeated tritium to an ion chamber, the gas-driven permeation of tritium has been performed on 321 type stainless steel containers with Al{sub 2}O{sub 3}/FeAl barriers, to determine the T-permeation resistant performance and mechanism of the barrier. The tritium permeability of the Al{sub 2}O{sub 3}/FeAl coated container was reduced by 3 orders of magnitude at 500–700 °C by contrast with that of the bare one, which meets the requirement of the tritium permeation reduction factor (PRF) of TPBs for tritium operating components in the CN-HCCB TBM. The Al{sub 2}O{sub 3}/FeAl barrier resists the tritium permeation by the diffusion in the bulk substrate at a limited number of defect sites with an effective area and thickness, suggesting that the TPB quality is a very important factor for efficient T-permeation resistance. - Highlights: • T-permeation has been measured on bare and coated type 321 SS containers. • Al{sub 2}O{sub 3}/FeAl coating give a reduction of T-permeability of 3 orders of magnitude. • Mechanism of Al{sub 2}O{sub 3}/FeAl barrier resisting T-permeation has obtained. • Quality of TPB is a very important factor for efficient T-permeating reduction.

  4. Development of a hydrogen permeation sensor for future tritium applications

    Energy Technology Data Exchange (ETDEWEB)

    Llivina, L.; Colominas, S.; Abellà, J., E-mail: sergi.colominas@iqs.es

    2014-10-15

    Highlights: • Designing and testing of a hydrogen permeation sensor. • Palladium and α-iron have been used as a hydrogen permeation materials in the sensor. • The experiments performed using both membranes showed that the operation of the sensors in the equilibrium mode required at least several hours to reach the hydrogen equilibrium pressure. - Abstract: Tritium monitoring in lithium–lead eutectic is of great importance for the performance of liquid blankets in fusion reactors. In addition, tritium measurements will be required in order to proof tritium self-sufficiency in liquid metal breeding systems. On-line hydrogen (isotopes) sensors must be design and tested in order to accomplish these goals. In this work, an experimental set up was designed in order to test the permeation hydrogen sensors at 500 °C. This experimental set-up allowed working with controlled environments (different hydrogen partial pressures) and the temperature was measured using a thermocouple connected to a temperature controller that regulated an electrical heater. In a first set of experiments, a hydrogen sensor was constructed using an α-iron capsule as an active hydrogen area. The sensor was mounted and tested in the experimental set up. In a second set of experiments the α-iron capsule was replaced by a welded thin palladium disk in order to minimize the death volume. The experiments performed using both membranes (α-iron and palladium) showed that the operation of the sensors in the equilibrium mode required at least several hours to reach the hydrogen equilibrium pressure.

  5. Feasibility of permeation grouting for constructing subsurface barriers

    International Nuclear Information System (INIS)

    Dwyer, B.P.

    1994-04-01

    Efforts are being made to devise technologies that provide interim containment of waste sites while final remediation alternatives are developed. Permeation grouting, a technique used extensively in the civil and mining engineering industry has been investigated as a method for emplacing a subsurface containment barrier beneath existing waste sites. Conceptually an underlying barrier is placed by injecting grout into the formation at less than fracturing pressure from a series of directionally drilled boreholes beneath the waste site. This study evaluated the penetration and performance characteristics in varying soil conditions of four different grout materials (two microfine cements, mineral wax, and sodium silicate) at a field scale. Field testing consisted of grout injection via sleeve (tube-a'-manchette) pipe into both vertical and horizontal borehole configurations at the Mixed Waste Landfill Integrated Demonstration site at Sandia National Laboratories. Prior to, during, and after grout injection non-intrusive geophysical techniques were used to map grout flow. Following the tests, the site was excavated to reveal details of the grout permeation, and grouted soil samples were cored for laboratory characterization. The non-intrusive and intrusive grout mapping showed preferential flow patterns, i.e., the grout tended to follow the path of least resistance. Preliminary testing indicates that permeation grouting is a feasible method for emplacing a low permeability subsurface barrier in the semi-arid unconsolidated alluvial soils common to the Southwest. Despite the success of this project, difficulties in predicting grout flow in heterogeneous soils and non-intrusive methods for imaging grout location and continuity are issues that need more attention

  6. Effect of Microneedle Type on Transdermal Permeation of Rizatriptan.

    Science.gov (United States)

    Uppuluri, Chandrateja; Shaik, Ashraf Sultana; Han, Tao; Nayak, Atul; Nair, Karthik J; Whiteside, Benjamin R; Nalluri, Buchi N; Das, Diganta B

    2017-07-01

    The present study was aimed to investigate the effect of salient microneedle (MN) geometry parameters like length, density, shape and type on transdermal permeation of rizatriptan (RIZ). Studies were carried out using two types of MN devices viz. AdminPatch® arrays (ADM) (0.6, 0.9, 1.2 and 1.5 mm lengths) and laboratory-fabricated polymeric MNs (PMs) of 0.6 mm length. In the case of the PMs, arrays were applied three times at different places within a 1.77-cm 2 skin area (PM-3) to maintain the MN density closer to 0.6 mm ADM. Histological studies revealed that PM, owing to their geometry/design, formed wider and deeper microconduits when compared to ADM of similar length. Approximately 4.9- and 4.2-fold increases in the RIZ steady-state flux values were observed with 1.5 mm ADM and PM-3 applications when compared to the passive studies. A good correlation between different dimensionless parameters like the amount of RIZ permeated (C t /C s ), thickness (h/L) and surface area (S a /L 2 ) of the skin was observed with scaling analyses. Numerical simulations provided further information regarding the distribution of RIZ in MN-treated skin after application of different MNs. Overall, the study suggests that MN application enhances the RIZ transdermal permeation and the geometrical parameters of MNs play an important role in the degree enhancement.

  7. Ionic Selectivity and Permeation Properties of Human PIEZO1 Channels.

    Directory of Open Access Journals (Sweden)

    Radhakrishnan Gnanasambandam

    Full Text Available Members of the eukaryotic PIEZO family (the human orthologs are noted hPIEZO1 and hPIEZO2 form cation-selective mechanically-gated channels. We characterized the selectivity of human PIEZO1 (hPIEZO1 for alkali ions: K+, Na+, Cs+ and Li+; organic cations: TMA and TEA, and divalents: Ba2+, Ca2+, Mg2+ and Mn2+. All monovalent ions permeated the channel. At a membrane potential of -100 mV, Cs+, Na+ and K+ had chord conductances in the range of 35-55 pS with the exception of Li+, which had a significantly lower conductance of ~ 23 pS. The divalents decreased the single-channel permeability of K+, presumably because the divalents permeated slowly and occupied the open channel for a significant fraction of the time. In cell-attached mode, 90 mM extracellular divalents had a conductance for inward currents carried by the divalents of: 25 pS for Ba2+ and 15 pS for Ca2+ at -80 mV and 10 pS for Mg2+ at -50 mV. The organic cations, TMA and TEA, permeated slowly and attenuated K+ currents much like the divalents. As expected, the channel K+ conductance increased with K+ concentration saturating at ~ 45 pS and the KD of K+ for the channel was 32 mM. Pure divalent ion currents were of lower amplitude than those with alkali ions and the channel opening rate was lower in the presence of divalents than in the presence of monovalents. Exposing cells to the actin disrupting reagent cytochalasin D increased the frequency of openings in cell-attached patches probably by reducing mechanoprotection.

  8. Evaluation of a dynamic dissolution/permeation model

    DEFF Research Database (Denmark)

    Sironi, Daniel; Christensen, Mette; Rosenberg, Jörg

    2017-01-01

    -steady state). To this end, a model case was construed: compacts of pure crystalline hydrocortisone methanolate (HC·MeOH) of slow release rates were prepared, and their dissolution and permeation determined simultaneously in a side-by-side setup, separated by a biomimetic barrier (Permeapad...... dissolution rate and flux influenced each other. Interestingly, for all the dynamic scenarios, the incremental flux values obtained correlated nicely with the corresponding actual donor concentrations. Furthermore, donor depletion was tested using a HC solution. The dynamic interplay between decrease in donor...

  9. Extraction of tritium from liquid lithium by permeation

    International Nuclear Information System (INIS)

    Alire, R.M.

    1978-01-01

    This paper assesses a method for extracting tritium from liquid lithium for specific application to the conceptual laser fusion reactor that uses a continuous lithium ''waterfall.'' The tritium diffuses through a refractory metal that contains a getter and is then stored in a hydride-forming alloy. There are various uncertainties with this method including helium-4 extraction, unknown impurities that may accumulate in liquid lithium, the effects of these impurities on tritium separation, and the maintenance of tritium-contaminated equipment. Our study indicates that major tritium losses will occur during equipment maintenance rather than as a result of permeation losses through the primary vessel

  10. Design and tritium permeation analysis of China HCCB TBM port cell

    International Nuclear Information System (INIS)

    Jiangfeng, S.; Guoqiang, H.; Zhiyong, H.; Chang'an, C.; Deli, L.

    2015-01-01

    China is planning to develop a helium-cooled ceramic breeder (HCCB) test blanket module (TBM) on ITER to test key blanket technologies. In this paper, the design and tritium permeation analysis of China HCCB TBM port cell are introduced. A theoretical model has been developed to estimate tritium permeation rates and leak rates from the components and pipes which China has scheduled to house in the port cell. It is shown that on normal working conditions, the permeation and leak rate of the systems in the port cell will be no higher than 1.58 Ci/d without the use of tritium permeation barriers, and 0.10 Ci/d with the use of tritium permeation barriers. It also appears that tritium permeation barriers are necessary for high temperature components such as the reduction bed and the heater

  11. Design and tritium permeation analysis of China HCCB TBM port cell

    Energy Technology Data Exchange (ETDEWEB)

    Jiangfeng, S.; Guoqiang, H.; Zhiyong, H.; Chang' an, C.; Deli, L. [China Academy of Engineering Physics, Mianyang, Sichuan (China)

    2015-03-15

    China is planning to develop a helium-cooled ceramic breeder (HCCB) test blanket module (TBM) on ITER to test key blanket technologies. In this paper, the design and tritium permeation analysis of China HCCB TBM port cell are introduced. A theoretical model has been developed to estimate tritium permeation rates and leak rates from the components and pipes which China has scheduled to house in the port cell. It is shown that on normal working conditions, the permeation and leak rate of the systems in the port cell will be no higher than 1.58 Ci/d without the use of tritium permeation barriers, and 0.10 Ci/d with the use of tritium permeation barriers. It also appears that tritium permeation barriers are necessary for high temperature components such as the reduction bed and the heater.

  12. Hydrogen permeation through Flinabe fluoride molten salts for blanket candidates

    Energy Technology Data Exchange (ETDEWEB)

    Nishiumi, Ryosuke, E-mail: r.nishiumi@aees.kyushu-u.ac.jp; Fukada, Satoshi; Nakamura, Akira; Katayama, Kazunari

    2016-11-01

    Highlights: • H{sub 2} diffusivity, solubility and permeability in Flinabe as T breeder are determined. • Effects in composition differences among Flibe, Fnabe and Flinabe are compared. • Changes of pressure dependence of Flinabe permeation rate are clarified. - Abstract: Fluoride molten salt Flibe (2LiF + BeF{sub 2}) is a promising candidate for the liquid blanket of a nuclear fusion reactor, because of its large advantages of tritium breeding ratio and heat-transfer fluid. Since its melting point is higher than other liquid candidates, another new fluoride molten salt Flinabe (LiF + NaF + BeF{sub 2}) is recently focused on because of its lower melting point while holding proper breeding properties. In this experiment, hydrogen permeation behavior through the three molten salts of Flibe (2LiF + BeF{sub 2}), Fnabe (NaF + BeF{sub 2}) and Flinabe are investigated in order to clarify the effects of their compositions on hydrogen transfer properties. After making up any of the three molten salts and purifying it using HF, hydrogen permeability, diffusivity and solubility of the molten salts are determined experimentally by using a system composed of tertiary cylindrical tubes. Close agreement is obtained between experimental data and analytical solutions. H{sub 2} permeability, diffusivity and solubility are correlated as a function of temperature and are compared among the three molten salts.

  13. Tritium permeation barrier based on self-healing composite materials

    International Nuclear Information System (INIS)

    Gao Jifeng; Zhang Dan; Suo Jinping

    2010-01-01

    Pores and cracks in ceramic coatings is one of the most important problems to be solved for the thermally sprayed tritium permeation barriers (TPBs) in fusion reactor. In this work, we developed a self-healing composite coating to address this problem. The coating composed of TiC + mixture(TiC/Al 2 O 3 ) + Al 2 O 3 was deposited on martensitic steels by means of atmospheric plasma spraying (APS). Before and after heat treatment, the morphology and phase of the coating were comparatively investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). In the experiment, NiAl + Al 2 O 3 , mixture(TiC/Al 2 O 3 ) + Al 2 O 3 and NiAl + TiC + mixture(TiC/Al 2 O 3 ) + Al 2 O 3 films were also fabricated and studied, respectively. The results showed that the TiC + mixture(TiC/Al 2 O 3 ) + Al 2 O 3 coating exhibited the best self-healing ability and good thermal shock resistance among the four samples after heat treatment under normal atmosphere. The SEM images analyzed by Image Pro software indicated that the porosity of the TiC + mixture(TiC/Al 2 O 3 ) + Al 2 O 3 coating decreased more than 90% in comparison with the sample before heat treatment. This self-healing coating made by thermal spraying might be a good candidate for tritium permeation barrier in fusion reactors.

  14. Effect of helium irradiation on deuterium permeation behavior in tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Uemura, Yuki; Sakurada, Shodai; Fujita, Hiroe; Azuma, Keisuke; Zhou, Quilai [Graduate School of Science & Technology, Shizuoka University, 836 Ohya, Suruga, Shizuoka, 422-8529 Japan (Japan); Hatano, Yuji [Hydrogen Isotope Research Center, University of Toyama, 3190 Gofuku, Toyama, 930-8555 Japan (Japan); Yoshida, Naoaki; Watanabe, Hideo [Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka, 816-8580 Japan (Japan); Oyaizu, Makoto; Isobe, Kanetsugu [National Institutes for Quantum and Radiological Science and Technology, 2166 Obuchi, Rokkasho, Aomori, 039-3212 Japan (Japan); Shimada, Masashi [Idaho National Laboratory, 1955 N. Fremont Avenue, Idaho Falls, ID 83415 (United States); Buchenauer, Dean; Kolasinski, Robert [Sandia National Laboratories, Chemistry, Combustion and Materials Center, Livermore, CA 94550 (United States); Chikada, Takumi [Graduate School of Science & Technology, Shizuoka University, 836 Ohya, Suruga, Shizuoka, 422-8529 Japan (Japan); Oya, Yasuhisa, E-mail: oya.yasuhisa@shizuoka.ac.jp [Graduate School of Science & Technology, Shizuoka University, 836 Ohya, Suruga, Shizuoka, 422-8529 Japan (Japan)

    2017-07-15

    In this study, we measured deuterium (D) gas-driven permeation through tungsten (W) foils that had been pre-damaged by helium ions (He{sup +}). The goal of this work was to determine how ion-induced damage affects hydrogen isotope permeation. At 873 K, the D permeability for W irradiated by 3.0 keV He{sup +} was approximately one order of magnitude lower than that for un-damaged W. This difference diminished with increasing temperature. Even after heating to 1173 K, the permeability returned to less than half of the value measured for un-damaged W. We propose that this is due to nucleation of He bubbles near the surface which potentially serve as a barrier to diffusion deeper into the bulk. Exposure at higher temperatures shows that the D permeability and diffusion coefficients return to levels observed for undamaged material. It is possible that these effects are linked to annealing of defects introduced by ion damage, and whether the defects are stabilized by the presence of trapped He.

  15. Permeation of limonene through disposable nitrile gloves using a dextrous robot hand.

    Science.gov (United States)

    Banaee, Sean; S Que Hee, Shane

    2017-03-28

    The purpose of this study was to investigate the permeation of the low-volatile solvent limonene through different disposable, unlined, unsupported, nitrile exam whole gloves (blue, purple, sterling, and lavender, from Kimberly-Clark). This study utilized a moving and static dextrous robot hand as part of a novel dynamic permeation system that allowed sampling at specific times. Quantitation of limonene in samples was based on capillary gas chromatography-mass spectrometry and the internal standard method (4-bromophenol). The average post-permeation thicknesses (before reconditioning) for all gloves for both the moving and static hand were more than 10% of the pre-permeation ones (P≤0.05), although this was not so on reconditioning. The standardized breakthrough times and steady-state permeation periods were similar for the blue, purple, and sterling gloves. Both methods had similar sensitivity. The lavender glove showed a higher permeation rate (0.490±0.031 μg/cm 2 /min) for the moving robotic hand compared to the non-moving hand (P≤0.05), this being ascribed to a thickness threshold. Permeation parameters for the static and dynamic robot hand models indicate that both methods have similar sensitivity in detecting the analyte during permeation and the blue, purple, and sterling gloves behave similarly during the permeation process whether moving or non-moving.

  16. Permeation of limonene through disposable nitrile gloves using a dextrous robot hand

    Science.gov (United States)

    Banaee, Sean; S Que Hee, Shane

    2017-01-01

    Objectives: The purpose of this study was to investigate the permeation of the low-volatile solvent limonene through different disposable, unlined, unsupported, nitrile exam whole gloves (blue, purple, sterling, and lavender, from Kimberly-Clark). Methods: This study utilized a moving and static dextrous robot hand as part of a novel dynamic permeation system that allowed sampling at specific times. Quantitation of limonene in samples was based on capillary gas chromatography-mass spectrometry and the internal standard method (4-bromophenol). Results: The average post-permeation thicknesses (before reconditioning) for all gloves for both the moving and static hand were more than 10% of the pre-permeation ones (P≤0.05), although this was not so on reconditioning. The standardized breakthrough times and steady-state permeation periods were similar for the blue, purple, and sterling gloves. Both methods had similar sensitivity. The lavender glove showed a higher permeation rate (0.490±0.031 μg/cm2/min) for the moving robotic hand compared to the non-moving hand (P≤0.05), this being ascribed to a thickness threshold. Conclusions: Permeation parameters for the static and dynamic robot hand models indicate that both methods have similar sensitivity in detecting the analyte during permeation and the blue, purple, and sterling gloves behave similarly during the permeation process whether moving or non-moving. PMID:28111415

  17. Development of Novel Formulations to Enhance in Vivo Transdermal Permeation of Tocopherol

    Directory of Open Access Journals (Sweden)

    Nada Aly H.

    2014-09-01

    Full Text Available Tocopherol represents a big challenge for transdermal permeation owing to its extreme hydrophobicity and large molecular mass. The aim of the present study was to develop alpha-tocopherol (T topical formulations and evaluate their ex vivo and in vivo permeation. Franz diffusion cells were used for ex vivo permeation, and neonatal rats were used for in vivo permeation. Seven gel formulations and 21 liquid formulations were investigated for physical stability, viscosity and permeation of T. Analysis of T was performed by a validated HPLC method using a UV detector. The ex vivo permeation from gel and emulsion formulations was very poor (0.001-0.015 %. Highest permeation was observed from monophasic liquid formulations containing dimethyl sulfoxide (DMSO, tocopheryl polyethylene glycols (TPGs, propylene glycol, ethanol and 9.5 % T. The in vivo results demonstrated higher retention in the epidermis compared to subcutaneous tissues, 1377 and 1.13 μg g-1, respectively. Increasing T concentration from 4.8 to 9.5 % did not increase the amount permeated or % of T retained. It was concluded that simple solutions of T in the presence of DMSO and TPGs were more promising systems for effective transdermal permeation compared to gel, emulsion or oleaginous systems.

  18. Hydrogen gas driven permeation through tungsten deposition layer formed by hydrogen plasma sputtering

    International Nuclear Information System (INIS)

    Uehara, Keiichiro; Katayama, Kazunari; Date, Hiroyuki; Fukada, Satoshi

    2015-01-01

    Highlights: • H permeation tests for W layer formed by H plasma sputtering are performed. • H permeation flux through W layer is larger than that through W bulk. • H diffusivity in W layer is smaller than that in W bulk. • The equilibrium H concentration in W layer is larger than that in W bulk. - Abstract: It is important to evaluate the influence of deposition layers formed on plasma facing wall on tritium permeation and tritium retention in the vessel of a fusion reactor from a viewpoint of safety. In this work, tungsten deposition layers having different thickness and porosity were formed on circular nickel plates by hydrogen RF plasma sputtering. Hydrogen permeation experiment was carried out at the temperature range from 250 °C to 500 °C and at hydrogen pressure range from 1013 Pa to 101,300 Pa. The hydrogen permeation flux through the nickel plate with tungsten deposition layer was significantly smaller than that through a bare nickel plate. This indicates that a rate-controlling step in hydrogen permeation was not permeation through the nickel plate but permeation though the deposition layer. The pressure dependence on the permeation flux differed by temperature. Hydrogen permeation flux through tungsten deposition layer is larger than that through tungsten bulk. From analysis of the permeation curves, it was indicated that hydrogen diffusivity in tungsten deposition layer is smaller than that in tungsten bulk and the equilibrium hydrogen concentration in tungsten deposition layer is enormously larger than that in tungsten bulk at same hydrogen pressure.

  19. Permeation of chromium salts through human skin in vitro

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Fullerton, A; Avnstorp, C

    1992-01-01

    Chromium permeation studies were performed on full thickness human skin in diffusion cells. All samples were analysed for the total chromium content by graphite furnace Zeeman-corrected atomic absorption spectrometry. Some samples were analysed by an ion chromatographic method permitting...... the simultaneous determination of Cr(VI) and Cr(III) as well. The amounts of chromium found in all skin layers were significantly higher when potassium dichromate was applied to the skin compared with chromium chloride or chromium nitrate. Chromium could only be detected in the recipient phase after application...... of the dichromate solution. Chromium skin levels increased with increasing concentrations of applied chromium salts up to 0.034 M Cr. The amount of chromium in recipient phase and skin layers increased with increasing pH when the applied solution contained potassium dichromate. This was ascribed to a decreased skin...

  20. Electrostatic tuning of permeation and selectivity in aquaporin water channels

    DEFF Research Database (Denmark)

    Jensen, Mogens O Stibius; Tajkhorshid, E.; Schulten, K.

    2003-01-01

    Water permeation and electrostatic interactions between water and channel are investigated in the Escherichia coli glycerol uptake facilitator GlpF, a member of the aquaporin water channel family, by molecular dynamics simulations. A tetrameric model of the channel embedded in a 16:0/ 18:1c9...... with the protein electrostatic fields enforce a bipolar water configuration inside the channel with dipole inversion at the NPA motifs. At the NPA motifs water-protein electrostatic interactions facilitate this inversion. Furthermore, water-water electrostatic interactions are in all regions inside the channel...... stronger than water-protein interactions, except near a conserved, positively charged Arg residue. We find that variations of the protein electrostatic field through the channel, owing to preserved structural features, completely explain the bipolar orientation of water. This orientation persists despite...

  1. Tritium permeation barrier based on self-healing composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Gao Jifeng; Zhang Dan [State Key Laboratory of Mould Technology, Institute of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Suo Jinping, E-mail: jpsuo@yahoo.com.cn [State Key Laboratory of Mould Technology, Institute of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2010-12-15

    Pores and cracks in ceramic coatings is one of the most important problems to be solved for the thermally sprayed tritium permeation barriers (TPBs) in fusion reactor. In this work, we developed a self-healing composite coating to address this problem. The coating composed of TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} was deposited on martensitic steels by means of atmospheric plasma spraying (APS). Before and after heat treatment, the morphology and phase of the coating were comparatively investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). In the experiment, NiAl + Al{sub 2}O{sub 3}, mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} and NiAl + TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} films were also fabricated and studied, respectively. The results showed that the TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} coating exhibited the best self-healing ability and good thermal shock resistance among the four samples after heat treatment under normal atmosphere. The SEM images analyzed by Image Pro software indicated that the porosity of the TiC + mixture(TiC/Al{sub 2}O{sub 3}) + Al{sub 2}O{sub 3} coating decreased more than 90% in comparison with the sample before heat treatment. This self-healing coating made by thermal spraying might be a good candidate for tritium permeation barrier in fusion reactors.

  2. Design, performance and manufacturing analysis for a compact permeator

    Energy Technology Data Exchange (ETDEWEB)

    Sacristan, R., E-mail: mrosa.sacristan@sener.es [SENER Ingenieria y Sistemas, Provenza 392, 5a 08025 Barcelona (Spain); Veredas, G. [EURATOM-CIEMAT Fusion Assoc., BBTU, Av. Complutense 22, 28040, Madrid (Spain); Bonjoch, I. [SENER Ingenieria y Sistemas, Provenza 392, 5a 08025 Barcelona (Spain); Fernandez, I. [EURATOM-CIEMAT Fusion Assoc., BBTU, Av. Complutense 22, 28040, Madrid (Spain); Martin, G. [SENER Ingenieria y Sistemas, Provenza 392, 5a 08025 Barcelona (Spain); Sanmarti, M. [b-FUS, Jardins de les Dones de Negre, 08930 Santa Adria de Besos, Barcelona (Spain); Sedano, L. [EURATOM-CIEMAT Fusion Assoc., BBTU, Av. Complutense 22, 28040, Madrid (Spain)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Not a single manufacturing option fulfills fully all the requirements that the PAV needs due to complicated manufacturing geometry and materials. Black-Right-Pointing-Pointer To avoid permeation in piping joints is a challenge. Black-Right-Pointing-Pointer CFD sensibility analysis and efficiency analysis show that the aim of the experiment can be accomplished. - Abstract: A fast and efficient recovery of bred tritium is a major milestone of tritium breeding technologies R and D for the demonstration of a fusion reactor tritium self-sufficiency. Permeator against vacuum (PAV) runs as a single-step process for tritium on-line recovery, acts as passive systems allowing to be thermally governed can be easily in-pipe integrated in LiPb loop systems and can be conceived with high compactness. An optimal PAV design is proposed with detailed design parameterization of tritium recovery efficiency at different velocity ranges from numerical simulation based on properly developed Openfoam{sup Registered-Sign} CFD code BelFoam{sup Registered-Sign} customized solver. Diverse structural design options are being considered to manufacture the PAV component that presents diverse manufacturing concerns. Fabrication options are exploring rolling of thin plate with internal armor in the vacuum gap up to the coating of a porous controlled thick wall. The aim of this paper is to emphasize on the advanced performance of the PAV proposed concept, to present and discuss the different technical solutions that have been studied as well as the fabrication tests carried out.

  3. Current Design of the Flange Type Hydrogen Permeation Sensor in Liquid Breeder

    International Nuclear Information System (INIS)

    Lee, E. H.; Jin, H. G.; Yoon, J. S.; Kim, S. K.; Lee, D. W.; Lee, H. G.

    2015-01-01

    In 2004, A. Ciampichetti et al. proposed a hollow capsule shape permeation sensor and they theoretically and experimentally evaluated the performance of the sensor made of Nb membrane at test condition of 500 .deg. C. However, the evaluation result showed the measured hydrogen permeation flux in the sensor much lower than the predicted one and they concluded that, the result is due to the formation of an oxide layer on the sensor membrane surface. Three years later, A. Ciampichetti et al. observed that a hollow capsule shape permeation sensor has too long response time to measure hydrogen concentration in liquid breeder. However, they suggested optimizing the sensor geometry with the reduction of the ratio 'total sensor volume/permeation surface' to overcome the low hydrogen permeating flux. For development of the liquid breeding technologies in nuclear fusion, the permeation sensor to measure tritium concentration in liquid metal breeder has been developed. Lee et al. proposed a flange type permeation sensor to dramatically reduce the ratio sensor 'inside volume/permeation surface' and to remove membrane welding during sensor manufacture process. However, the flange type sensor has problem with sealing. In present study, the modified flange sensor design with a metallic C-ring spring gasket is introduced. The modified sensor will be verified and evaluated under high temperature conditions by end of 2015

  4. Oxygen permeation through oxygen ion oxide-noble metal dual phase composites

    NARCIS (Netherlands)

    Chen, C.S.; Chen, C.S.; Kruidhof, H.; Bouwmeester, Henricus J.M.; Verweij, H.; Burggraaf, Anthonie; Burggraaf, A.J.

    1996-01-01

    Oxygen permeation behaviour of three composites, yttria-stabilized zirconia-palladium, erbia-stabilized bismuth oxidenoble metal (silver, gold) was studied. Oxygen permeation measurements were performed under controlled oxygen pressure gradients at elevated temperatures. Air was supplied at one side

  5. 40 CFR 1060.102 - What permeation emission control requirements apply for fuel lines?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What permeation emission control... AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT Emission Standards and Related Requirements § 1060.102 What permeation...

  6. 40 CFR 1060.103 - What permeation emission control requirements apply for fuel tanks?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What permeation emission control... AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE NONROAD AND STATIONARY EQUIPMENT Emission Standards and Related Requirements § 1060.103 What permeation...

  7. 40 CFR 90.129 - Fuel tank permeation from handheld engines and equipment.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Fuel tank permeation from handheld... KILOWATTS Emission Standards and Certification Provisions § 90.129 Fuel tank permeation from handheld... equipment with respect to fuel tanks. For the purposes of this section, fuel tanks do not include fuel caps...

  8. 40 CFR 1051.515 - How do I test my fuel tank for permeation emissions?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false How do I test my fuel tank for... Procedures § 1051.515 How do I test my fuel tank for permeation emissions? Measure permeation emissions by weighing a sealed fuel tank before and after a temperature-controlled soak. (a) Preconditioning fuel soak...

  9. 40 CFR 1060.520 - How do I test fuel tanks for permeation emissions?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false How do I test fuel tanks for... STATIONARY EQUIPMENT Test Procedures § 1060.520 How do I test fuel tanks for permeation emissions? Measure permeation emissions by weighing a sealed fuel tank before and after a temperature-controlled soak. (a...

  10. Modeling benzene permeation through drinking water high density polyethylene (HDPE) pipes.

    Science.gov (United States)

    Mao, Feng; Ong, Say Kee; Gaunt, James A

    2015-09-01

    Organic compounds such as benzene, toluene, ethyl benzene and o-, m-, and p-xylene from contaminated soil and groundwater may permeate through thermoplastic pipes which are used for the conveyance of drinking water in water distribution systems. In this study, permeation parameters of benzene in 25 mm (1 inch) standard inside dimension ratio (SIDR) 9 high density polyethylene (HDPE) pipes were estimated by fitting the measured data to a permeation model based on a combination of equilibrium partitioning and Fick's diffusion. For bulk concentrations between 6.0 and 67.5 mg/L in soil pore water, the concentration-dependent diffusion coefficients of benzene were found to range from 2.0×10(-9) to 2.8×10(-9) cm2/s while the solubility coefficient was determined to be 23.7. The simulated permeation curves of benzene for SIDR 9 and SIDR 7 series of HDPE pipes indicated that small diameter pipes were more vulnerable to permeation of benzene than large diameter pipes, and the breakthrough of benzene into the HDPE pipe was retarded and the corresponding permeation flux decreased with an increase of the pipe thickness. HDPE pipes exposed to an instantaneous plume exhibited distinguishable permeation characteristics from those exposed to a continuous source with a constant input. The properties of aquifer such as dispersion coefficients (DL) also influenced the permeation behavior of benzene through HDPE pipes.

  11. Current Design of the Flange Type Hydrogen Permeation Sensor in Liquid Breeder

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E. H.; Jin, H. G.; Yoon, J. S.; Kim, S. K.; Lee, D. W. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, H. G. [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In 2004, A. Ciampichetti et al. proposed a hollow capsule shape permeation sensor and they theoretically and experimentally evaluated the performance of the sensor made of Nb membrane at test condition of 500 .deg. C. However, the evaluation result showed the measured hydrogen permeation flux in the sensor much lower than the predicted one and they concluded that, the result is due to the formation of an oxide layer on the sensor membrane surface. Three years later, A. Ciampichetti et al. observed that a hollow capsule shape permeation sensor has too long response time to measure hydrogen concentration in liquid breeder. However, they suggested optimizing the sensor geometry with the reduction of the ratio 'total sensor volume/permeation surface' to overcome the low hydrogen permeating flux. For development of the liquid breeding technologies in nuclear fusion, the permeation sensor to measure tritium concentration in liquid metal breeder has been developed. Lee et al. proposed a flange type permeation sensor to dramatically reduce the ratio sensor 'inside volume/permeation surface' and to remove membrane welding during sensor manufacture process. However, the flange type sensor has problem with sealing. In present study, the modified flange sensor design with a metallic C-ring spring gasket is introduced. The modified sensor will be verified and evaluated under high temperature conditions by end of 2015.

  12. Hydrogen permeation inhibition by zinc-nickel alloy plating on steel XC68

    International Nuclear Information System (INIS)

    El Hajjami, A.; Gigandet, M.P.; De Petris-Wery, M.; Catonne, J.C.; Duprat, J.J.; Thiery, L.; Raulin, F.; Starck, B.; Remy, P.

    2008-01-01

    The inhibition of hydrogen permeation and barrier effect by zinc-nickel plating was investigated using the Devanathan-Stachurski permeation technique. The hydrogen permeation and hydrogen diffusion for the zinc-nickel (12-15%) plating on steel XC68 is compared with zinc and nickel. Hydrogen permeation and hydrogen diffusion were followed as functions of time at current density applied (cathodic side) and potential permanent (anodic side). The hydrogen permeation inhibition for zinc-nickel is intermediate to that of nickel and zinc. This inhibition was due to nickel-rich layer effects at the Zn-Ni alloy/substrate interface, is shown by GDOES. Zinc-nickel plating inhibited the hydrogen diffusion greater as compared to zinc. This diffusion resistance was due to the barrier effect caused by the nickel which is present at the interface and transformed the hydrogen atomic to Ni 2 H compound, as shown by GIXRD.

  13. Hydrogen permeation inhibition by zinc-nickel alloy plating on steel XC68

    Energy Technology Data Exchange (ETDEWEB)

    El Hajjami, A. [Institut UTINAM, UMR CNRS 6213, Sonochimie et Reactivite des Surfaces, Universite de Franche-Comte, 16 route de Gray, 25030 Besancon Cedex (France); Coventya S.A.S., 51 rue Pierre, 92588 Clichy Cedex (France); Gigandet, M.P. [Institut UTINAM, UMR CNRS 6213, Sonochimie et Reactivite des Surfaces, Universite de Franche-Comte, 16 route de Gray, 25030 Besancon Cedex (France)], E-mail: marie-pierre.gigandet@univ-fcomte.fr; De Petris-Wery, M. [Institut Universitaire de Technologie d' Orsay, Universite Paris XI, Plateau de Moulon, 91400 Orsay (France); Catonne, J.C. [Professeur Honoraire du Conservatoire national des arts et metiers (CNAM), Paris (France); Duprat, J.J.; Thiery, L.; Raulin, F. [Coventya S.A.S., 51 rue Pierre, 92588 Clichy Cedex (France); Starck, B.; Remy, P. [Lisi Automotive, 28 faubourg de Belfort, BP 19, 90101 Delle Cedex (France)

    2008-12-30

    The inhibition of hydrogen permeation and barrier effect by zinc-nickel plating was investigated using the Devanathan-Stachurski permeation technique. The hydrogen permeation and hydrogen diffusion for the zinc-nickel (12-15%) plating on steel XC68 is compared with zinc and nickel. Hydrogen permeation and hydrogen diffusion were followed as functions of time at current density applied (cathodic side) and potential permanent (anodic side). The hydrogen permeation inhibition for zinc-nickel is intermediate to that of nickel and zinc. This inhibition was due to nickel-rich layer effects at the Zn-Ni alloy/substrate interface, is shown by GDOES. Zinc-nickel plating inhibited the hydrogen diffusion greater as compared to zinc. This diffusion resistance was due to the barrier effect caused by the nickel which is present at the interface and transformed the hydrogen atomic to Ni{sub 2}H compound, as shown by GIXRD.

  14. Modell experiments to determine the effect of inhibitive oxide layers on metals against hydrogen permeation

    International Nuclear Information System (INIS)

    Zink, U.

    1983-11-01

    The coupling of H 2 -permeation and corrosion has been examined with the high-temperature alloys Incoloy 800 and Incoloy 802. Permeationsrates as well as corrosionsrates have been measured simultanously under H 2 O-H 2 atmospheres in the test-facility HD-PERM. Test parameters have been temperature and oxidationpotential. Parabolic laws for the growth of the oxide scales have been identified and are considered to be highly important for the efficiency of a permeation barrier. A comparison between the temperature dependencies of corrosionsrates and H 2 -permeationsrates has revealed that permeation and corrosion are coupled only in so far that the permeation barrier is formed by the corrosion reaction. The corrosion data (parabolic rate constant, activation energy) of the oxide scales have given clear indications for the existence of a Cr 2 O 3 -layer, which is considered to be responsible for efficient oxide permeation barriers. (orig.) [de

  15. Uses and evaluation methods of potential hydrogen permeation barriers for nuclear reactor materials

    International Nuclear Information System (INIS)

    Noga, J.O.; Piercy, G.R.; Bowker, J.T.

    1985-07-01

    This report summarizes results on the use of coatings as hydrogen permeation barriers on nuclear reactor component materials. Two classes of base materials were considered, exothermic hydrogen absorbers and endothermic hydrogen absorbers. The results of the tests indicate that substantial reductions in the amount of hydrogen absorbed by a metal can be achieved through the use of hydrogen permeation barrier coatings. Gold was determined to provide an effective hydrogen permeation barrier on Zr-2-1/2 Nb pressure tube material. Tin was determined to be a suitable hydrogen permeation barrier when applied on AISI 410 stainless steel and iron. Both gas phase and electrochemical permeation techniques were used to determine hydrogen permeabilities through coatings and base materials

  16. Fish remains and humankind: part two

    Directory of Open Access Journals (Sweden)

    Andrew K G Jones

    1998-07-01

    Full Text Available The significance of aquatic resources to past human groups is not adequately reflected in the published literature - a deficiency which is gradually being acknowledged by the archaeological community world-wide. The publication of the following three papers goes some way to redress this problem. Originally presented at an International Council of Archaeozoology (ICAZ Fish Remains Working Group meeting in York, U.K. in 1987, these papers offer clear evidence of the range of interest in ancient fish remains across the world. Further papers from the York meeting were published in Internet Archaeology 3 in 1997.

  17. Value of conventional, and diffusion- and perfusion weighted MRI in the management of patients with unclear cerebral pathology, admitted to the intensive care unit

    International Nuclear Information System (INIS)

    Sundgren, P.C.; Reinstrup, P.; Romner, B.; Holtaas, S.; Maly, P.

    2002-01-01

    The aim of our retrospective study was to determine the extent to which diffusion- and perfusion- weighted MRI combined with conventional MRI could be helpful in the evaluation of intensive care unit (ICU) patients who have unknown or unclear cerebral pathology underlying a serious clinical condition. Twenty-one ICU patients with disparity between the findings on brain CT scan and their clinical status were studied. All patients underwent conventional MR and diffusion-weighted imaging and 14 also had MR perfusion studies. Abnormalities were present on diffusion-weighted imaging of 17 of the 21 patients and on perfusion-weighted studies of 7 of 14 patients. The MRI results changed the preliminary/working diagnosis in six patients. In eight other patients, MRI revealed additional pathology that had not been suspected clinically, and/or characterized more closely findings that had already been detected by CT or suspected clinically. MRI showed abnormalities in four of the five patients who had normal CT. MRI findings suggested a negative clinical outcome in all nine patients who subsequently died. MRI findings also suggested positive long-term outcome in five of nine patients who improved significantly as based on Glasgow and extended Glasgow outcome scales. In the three unconscious patients who had normal diffusion- and perfusion-weighted imaging the clinical outcome was good. This study suggests that MRI in seriously ill ICU patients with unclear cerebral pathology can provide information that changes, characterizes, or supports diagnoses and/or prognoses and therefore facilitates further management. (orig.)

  18. By the numbers: Structure-seeking individuals prefer quantitative over qualitative representations of personal value to compensate for the threat of unclear performance contingencies.

    Science.gov (United States)

    Rothschild, Zachary K; Landau, Mark J; Sullivan, Daniel

    2011-11-01

    What combination of dispositional and situational factors leads people to represent their personal value in quantitative terms (e.g., salary) rather than qualitative terms (e.g., virtue)? Integrating research on quantitative information seeking, dispositional epistemic motivation, and learned helplessness, the current article hypothesized that individuals high, but not low, in uncertainty avoidance (measured with the Personal Need for Structure Scale [PNS]) would prefer quantitative (over qualitative) value representations to compensate for the diminished self-esteem certainty caused by exposure to unclear performance contingencies. Accordingly, in Study 1 high-PNS participants exposed to unclear (vs. clear) performance contingencies in one domain (visual intelligence) preferred a quantitative value representation in another domain (verbal intelligence). Study 2 showed that this effect is mediated by self-esteem certainty, not self-esteem level. Study 3 included a failure feedback condition to further isolate the role of epistemic motivation, as distinct from self-enhancement motivation, in driving the tendency to quantify personal value.

  19. Whole glove permeation of cyclohexanol through disposable nitrile gloves on a dextrous robot hand: Fist clenching vs. non-clenching.

    Science.gov (United States)

    Mathews, Airek R; Que Hee, Shane S

    2017-04-01

    The differences in permeation parameters when a gloved dextrous robot hand clenched and did not were investigated with the dynamic permeation system described in the companion paper. Increased permeation through the gloves of the present study for cyclohexanol when the gloved hand clenched depended on glove thickness and porosity for cyclohexanol permeation. The Sterling glove, the thinnest and most porous, was the least protective. Hand clenching promoted more permeation for the Sterling glove in terms of breakthrough times, steady state permeation rate, and diffusion coefficient. The Safeskin glove showed increased permeation only for the steady state permeation rate but not breakthrough times or diffusion coefficient. The Blue and Purple gloves showed no differences when the hand was clenching or not. The correlational analysis supported differences between the clenching and non-clenching situations, and the risk assessment considered the worst and best scenarios relative to one and two hydrated hands that were and were not protected by specific gloves.

  20. Why Agricultural Educators Remain in the Classroom

    Science.gov (United States)

    Crutchfield, Nina; Ritz, Rudy; Burris, Scott

    2013-01-01

    The purpose of this study was to identify and describe factors that are related to agricultural educator career retention and to explore the relationships between work engagement, work-life balance, occupational commitment, and personal and career factors as related to the decision to remain in the teaching profession. The target population for…

  1. Juveniles' Motivations for Remaining in Prostitution

    Science.gov (United States)

    Hwang, Shu-Ling; Bedford, Olwen

    2004-01-01

    Qualitative data from in-depth interviews were collected in 1990-1991, 1992, and 2000 with 49 prostituted juveniles remanded to two rehabilitation centers in Taiwan. These data are analyzed to explore Taiwanese prostituted juveniles' feelings about themselves and their work, their motivations for remaining in prostitution, and their difficulties…

  2. Kadav Moun PSA (:60) (Human Remains)

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

    This is an important public health announcement about safety precautions for those handling human remains. Language: Haitian Creole.  Created: 2/18/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 2/18/2010.

  3. The Annuity Puzzle Remains a Puzzle

    NARCIS (Netherlands)

    Peijnenburg, J.M.J.; Werker, Bas; Nijman, Theo

    We examine incomplete annuity menus and background risk as possible drivers of divergence from full annuitization. Contrary to what is often suggested in the literature, we find that full annuitization remains optimal if saving is possible after retirement. This holds irrespective of whether real or

  4. Explosives remain preferred methods for platform abandonment

    International Nuclear Information System (INIS)

    Pulsipher, A.; Daniel, W. IV; Kiesler, J.E.; Mackey, V. III

    1996-01-01

    Economics and safety concerns indicate that methods involving explosives remain the most practical and cost-effective means for abandoning oil and gas structures in the Gulf of Mexico. A decade has passed since 51 dead sea turtles, many endangered Kemp's Ridleys, washed ashore on the Texas coast shortly after explosives helped remove several offshore platforms. Although no relationship between the explosions and the dead turtles was ever established, in response to widespread public concern, the US Minerals Management Service (MMS) and National Marine Fisheries Service (NMFS) implemented regulations limiting the size and timing of explosive charges. Also, more importantly, they required that operators pay for observers to survey waters surrounding platforms scheduled for removal for 48 hr before any detonations. If observers spot sea turtles or marine mammals within the danger zone, the platform abandonment is delayed until the turtles leave or are removed. However, concern about the effects of explosives on marine life remains

  5. Increased albumin permeation in eyes, aorta, and kidney of hypertensive rats fed galactose

    International Nuclear Information System (INIS)

    Tilton, R.G.; LaRose, L.; Chang, K.; Weigel, C.J.; Williamson, J.R.

    1986-01-01

    These experiments were undertaken to determine whether ingestion of galactose increases albumin permeation in the vasculature of hypertensive rats. 50% dextrin (control) or 50% galactose diets were fed to unilaterally nephrectomized, male Sprague-Dawley rats weighing 200 g. Hypertension (systolic pressure >175 mmHg) was induced by weekly IM injections of 25 mg/kg DOCA and 1% saline drinking water; 3 months later 125 I-albumin permeation was assessed in whole eyes, aorta and kidneys. 125 I-albumin permeation was significantly increased in all 3 tissues of hypertensive rats (n = 9) vs controls (n = 9): aorta (3.30 +/- 0.19 (SD) vs 2.87 +/- 0.14), eye (3.15 +/- 0.14 vs 2.59 +/- 0.11), and kidney (6.58 +/- 0.63 vs 3.85 +/- 0.50). Albumin permeation was increased still further in hypertensive rats fed the galactose diet (n = 8): aorta (3.75 +/- 0.38), eye (3.82 +/- 0.17), and kidney (10.74 +/- 3.13). Hypertension +/- galactose feeding had no effect on albumin permeation in lung, skin, or brain. These findings indicate that: (1) hypertension increases albumin permeation in vessels affected by diabetic vascular diseases, and 2) hypertension-induced increases in albumin permeation are increased still further by galactose ingestion, presumably mediated by imbalances in polyol/insitol metabolism (analogous to those induced by diabetes) independent of hyperglycemia and/or insulinopenia

  6. SAMPA: A free software tool for skin and membrane permeation data analysis.

    Science.gov (United States)

    Bezrouk, Aleš; Fiala, Zdeněk; Kotingová, Lenka; Krulichová, Iva Selke; Kopečná, Monika; Vávrová, Kateřina

    2017-10-01

    Skin and membrane permeation experiments comprise an important step in the development of a transdermal or topical formulation or toxicological risk assessment. The standard method for analyzing these data relies on the linear part of a permeation profile. However, it is difficult to objectively determine when the profile becomes linear, or the experiment duration may be insufficient to reach a maximum or steady state. Here, we present a software tool for Skin And Membrane Permeation data Analysis, SAMPA, that is easy to use and overcomes several of these difficulties. The SAMPA method and software have been validated on in vitro and in vivo permeation data on human, pig and rat skin and model stratum corneum lipid membranes using compounds that range from highly lipophilic polycyclic aromatic hydrocarbons to highly hydrophilic antiviral drug, with and without two permeation enhancers. The SAMPA performance was compared with the standard method using a linear part of the permeation profile and a complex mathematical model. SAMPA is a user-friendly, open-source software tool for analyzing the data obtained from skin and membrane permeation experiments. It runs on a Microsoft Windows platform and is freely available as a Supporting file to this article. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Effect of permeation enhancers on the penetration mechanism of transfersomal gel of ketoconazole

    Directory of Open Access Journals (Sweden)

    Reshmy Rajan

    2012-01-01

    Full Text Available The aim of the present research work was to investigate the potential of transfersome formulations for transdermal delivery of Ketoconazole (KTZ. KTZ is a broad-spectrum antifungal agent that is active against a wide variety of fungi and yeasts. It is readily but incompletely absorbed after oral dosing and is highly variable. The transfersomes were formulated by lipid film hydration technique using Rotary vacuum Evaporator. The prepared transfersomes were converted into suitable gel formulation and is evaluated for their gel characteristics like pH, viscosity, spreadability, extrudability, homogeneity, drug content, etc. Suitable essential oils acting as natural permeation enhancers were added to the transfersomal formulation of KTZ for their release studies. Studies proved that addition of suitable permeation enhancers to the transfersomal formulation improved the release and permeation of KTZ, which showed that the permeation enhancers modify the barrier to penetration present in skin without itself undergoing any change. From the various essential oils which are used as permeation enhancers, the formulation containing Eucalyptus oil showed better in vitro release and permeation as compared with other formulations containing different permeation enhancers.

  8. Modeling the Effects of Interfacial Characteristics on Gas Permeation Behavior of Nanotube-Mixed Matrix Membranes.

    Science.gov (United States)

    Chehrazi, Ehsan; Sharif, Alireza; Omidkhah, Mohammadreza; Karimi, Mohammad

    2017-10-25

    Theoretical approaches that accurately predict the gas permeation behavior of nanotube-containing mixed matrix membranes (nanotube-MMMs) are scarce. This is mainly due to ignoring the effects of nanotube/matrix interfacial characteristics in the existing theories. In this paper, based on the analogy of thermal conduction in polymer composites containing nanotubes, we develop a model to describe gas permeation through nanotube-MMMs. Two new parameters, "interfacial thickness" (a int ) and "interfacial permeation resistance" (R int ), are introduced to account for the role of nanotube/matrix interfacial interactions in the proposed model. The obtained values of a int , independent of the nature of the permeate gas, increased by increasing both the nanotubes aspect ratio and polymer-nanotube interfacial strength. An excellent correlation between the values of a int and polymer-nanotube interaction parameters, χ, helped to accurately reproduce the existing experimental data from the literature without the need to resort to any adjustable parameter. The data includes 10 sets of CO 2 /CH 4 permeation, 12 sets of CO 2 /N 2 permeation, 3 sets of CO 2 /O 2 permeation, and 2 sets of CO 2 /H 2 permeation through different nanotube-MMMs. Moreover, the average absolute relative errors between the experimental data and the predicted values of the proposed model are very small (less than 5%) in comparison with those of the existing models in the literature. To the best of our knowledge, this is the first study where such a systematic comparison between model predictions and such extensive experimental data is presented. Finally, the new way of assessing gas permeation data presented in the current work would be a simple alternative to complex approaches that are usually utilized to estimate interfacial thickness in polymer composites.

  9. Changes in chemical permeation of disposable latex, nitrile, and vinyl gloves exposed to simulated movement.

    Science.gov (United States)

    Phalen, Robert N; Le, Thi; Wong, Weng Kee

    2014-01-01

    Glove movement can affect chemical permeation of organic compounds through polymer glove products. However, conflicting reports make it difficult to compare the effects of movement on chemical permeation through commonly available glove types. The aim of this study was to evaluate the effect of movement on chemical permeation of an organic solvent through disposable latex, nitrile, and vinyl gloves. Simulated whole-glove permeation testing was conducted using ethyl alcohol and a previously designed permeation test system. With exposure to movement, a significant decrease (p ≤ 0.001) in breakthrough time (BT) was observed for the latex (-23%) and nitrile gloves (-31%). With exposure to movement, only the nitrile glove exhibited a significant increase (p ≤ 0.001) in steady-state permeation rate (+47%) and cumulative permeation at 30 min (+111%). Even though the nitrile glove provided optimum chemical resistance against ethyl alcohol, it was most affected by movement. With exposure to movement, the latex glove was an equivalent option for overall worker protection, because it was less affected by movement and the permeation rate was lower than that of the nitrile glove. In contrast, the vinyl glove was the least affected by movement, but did not provide adequate chemical resistance to ethyl alcohol in comparison with the nitrile and latex gloves. Glove selection should take movement and polymer type into account. Some glove polymer types are less affected by movement, most notably the latex glove in this test. With nitrile gloves, at least a factor of three should be used when attempting to assign a protection factor when repetitive hand motions are anticipated. Ultimately, the latex gloves outperformed nitrile and vinyl in these tests, which evaluated the effect of movement on chemical permeation. Future research should aim to resolve some of the observed discrepancies in test results with latex and vinyl gloves.

  10. Human skin in vitro permeation of bentazon and isoproturon formulations with or without protective clothing suit.

    Science.gov (United States)

    Berthet, Aurélie; Hopf, Nancy B; Miles, Alexandra; Spring, Philipp; Charrière, Nicole; Garrigou, Alain; Baldi, Isabelle; Vernez, David

    2014-01-01

    Skin exposures to chemicals may lead, through percutaneous permeation, to a significant increase in systemic circulation. Skin is the primary route of entry during some occupational activities, especially in agriculture. To reduce skin exposures, the use of personal protective equipment (PPE) is recommended. PPE efficiency is characterized as the time until products permeate through material (lag time, Tlag). Both skin and PPE permeations are assessed using similar in vitro methods; the diffusion cell system. Flow-through diffusion cells were used in this study to assess the permeation of two herbicides, bentazon and isoproturon, as well as four related commercial formulations (Basagran(®), Basamais(®), Arelon(®) and Matara(®)). Permeation was measured through fresh excised human skin, protective clothing suits (suits) (Microchem(®) 3000, AgriSafe Pro(®), Proshield(®) and Microgard(®) 2000 Plus Green), and a combination of skin and suits. Both herbicides, tested by itself or as an active ingredient in formulations, permeated readily through human skin and tested suits (Tlag < 2 h). High permeation coefficients were obtained regardless of formulations or tested membranes, except for Microchem(®) 3000. Short Tlag, were observed even when skin was covered with suits, except for Microchem(®) 3000. Kp values tended to decrease when suits covered the skin (except when Arelon(®) was applied to skin covered with AgriSafe Pro and Microgard(®) 2000), suggesting that Tlag alone is insufficient in characterizing suits. To better estimate human skin permeations, in vitro experiments should not only use human skin but also consider the intended use of the suit, i.e., the active ingredient concentrations and type of formulations, which significantly affect skin permeation.

  11. SC lipid model membranes designed for studying impact of ceramide species on drug diffusion and permeation--part II: diffusion and permeation of model drugs.

    Science.gov (United States)

    Ochalek, M; Podhaisky, H; Ruettinger, H-H; Wohlrab, J; Neubert, R H H

    2012-10-01

    The barrier function of two quaternary stratum corneum (SC) lipid model membranes, which were previously characterized with regard to the lipid organization, was investigated based on diffusion studies of model drugs with varying lipophilicities. Diffusion experiments of a hydrophilic drug, urea, and more lipophilic drugs than urea (i.e. caffeine, diclofenac sodium) were conducted using Franz-type diffusion cells. The amount of permeated drug was analyzed using either HPLC or CE technique. The subjects of interest in the present study were the investigation of the influence of physicochemical properties of model drugs on their diffusion and permeation through SC lipid model membranes, as well as the study of the impact of the constituents of these artificial systems (particularly ceramide species) on their barrier properties. The diffusion through both SC lipid model membranes and the human SC of the most hydrophilic model drug, urea, was faster than the permeation of the more lipophilic drugs. The slowest rate of permeation through SC lipid systems occurred in the case of caffeine. The composition of SC lipid model membranes has a significant impact on their barrier function. Model drugs diffused and permeated faster through Membrane II (presence of Cer [EOS]). In terms of the barrier properties, Membrane II is much more similar to the human SC than Membrane I. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Permeation of a H2 + HD + D2 gas mixture through a polymer membrane

    International Nuclear Information System (INIS)

    Mercea, P.; Cuna, S.; Kreibik, S.; Ursu, I.

    1990-01-01

    The selective permeation of a H 2 + HD + D 2 gas mixture through a polyethylene terephthalate membrane was studied at T 20 0 C. It was found that the permeation of the HD through the membrane leads to a smaller overall hydrogen-deuterium separation factor than that determined in the permeation experiments with pure H 2 and D 2 . On the other hand, a process of isotopic exchange between deuterium atoms from the penetrant gas stream and hydrogen atoms from the polymer membrane is assumed and discussed in order to explain temporal variations of the H 2 , HD and D 2 concentrations of the permanent gas stream. (author)

  13. Practical experience of backwashing with SWRO permeate for UF fouling control

    KAUST Repository

    Li, Sheng; Heijman, Sebastiaan G J; Verberk, J. Q J C; Amy, Gary L.; Van Dijk, Johannis C.

    2013-01-01

    Effectiveness of seawater reverse osmosis (SWRO) permeate backwash on fouling control of seawater ultrafiltration was investigated at a pilot scale. A standard membrane module was used in this pilot to represent full-scale desalination plants. Results of the pilot show a good reproducibility. When the UF permeate was used for backwash, the frequency of chemically enhanced backwash (CEB) was around once per day. However, results of the pilot show that SWRO permeate backwashing could significantly reduce the CEB frequency. © 2013 Desalination Publications.

  14. Gas-driven permeation of deuterium through tungsten and tungsten alloys

    Energy Technology Data Exchange (ETDEWEB)

    Buchenauer, Dean A., E-mail: dabuche@sandia.gov [Sandia National Laboratories, Energy Innovation Department, Livermore, CA 94550 (United States); Karnesky, Richard A. [Sandia National Laboratories, Energy Innovation Department, Livermore, CA 94550 (United States); Fang, Zhigang Zak; Ren, Chai [University of Utah, Department of Metallurgical Engineering, Salt Lake City, UT 84112 (United States); Oya, Yasuhisa [Shizuoka University, Graduate School of Science, Shizuoka (Japan); Otsuka, Teppei [Kyushu University, Department of Advanced Energy Engineering Science, Fukuoka (Japan); Yamauchi, Yuji [Hokkaido University, Third Division of Quantum Science and Engineering, Faculty of Engineering, Sapporo (Japan); Whaley, Josh A. [Sandia National Laboratories, Energy Innovation Department, Livermore, CA 94550 (United States)

    2016-11-01

    Highlights: • We have designed and performed initial studies on a high temperature gas-driven permeation cell capable of operating at temperatures up to 1150 °C and at pressures between 0.1–1 atm. • Permeation measurements on ITER grade tungsten compare well with past studies by Frauenfelder and Zahkarov in the temperature range from 500 to 1000 °C. • First permeation measurements on Ti dispersoid-strengthened ultra-fine grained tungsten show higher permeation at 500 °C, but very similar permeation with ITER tungsten at 1000 °C. Diffusion along grain boundaries may be playing a role for this type of material. - Abstract: To address the transport and trapping of hydrogen isotopes, several permeation experiments are being pursued at both Sandia National Laboratories (deuterium gas-driven permeation) and Idaho National Laboratories (tritium gas- and plasma-driven tritium permeation). These experiments are in part a collaboration between the US and Japan to study the performance of tungsten at divertor relevant temperatures (PHENIX). Here we report on the development of a high temperature (≤1150 °C) gas-driven permeation cell and initial measurements of deuterium permeation in several types of tungsten: high purity tungsten foil, ITER-grade tungsten (grains oriented through the membrane), and dispersoid-strengthened ultra-fine grain (UFG) tungsten being developed in the US. Experiments were performed at 500–1000 °C and 0.1–1.0 atm D{sub 2} pressure. Permeation through ITER-grade tungsten was similar to earlier W experiments by Frauenfelder (1968–69) and Zaharakov (1973). Data from the UFG alloy indicates marginally higher permeability (< 10×) at lower temperatures, but the permeability converges to that of the ITER tungsten at 1000 °C. The permeation cell uses only ceramic and graphite materials in the hot zone to reduce the possibility for oxidation of the sample membrane. Sealing pressure is applied externally, thereby allowing for elevation

  15. Tritium permeation in stainless-steel structures exposed to plasma ions

    International Nuclear Information System (INIS)

    Anderl, R.A.; Holland, D.F.; Struttmann, D.A.; Longhurst, G.R.; Merrill, B.J.

    1985-01-01

    This paper presents a comparison of the hydrogen permeation properties of the austenitic primary candidate alloy, PCA, and of the advanced ferritic alloy, HT-9. The comparison is based on experimental measurements of the permeation and reemission of deuterium from specimens undergoing implantation with 3-keV, D 3 + ions produced by an accelerator. Characterization of the specimen surface facing the ion beam is provided by secondary ion mass spectrometer (SIMS) analysis of the species sputtered from the surface during the implantation. Recombination and diffusivity data for PCA and HT-9 were derived from an analysis in which model calculations were applied to the reemission and permeation measurements

  16. Investigation on the suitability of plasma sprayed Fe-Cr-Al coatings as tritium permeation barrier

    International Nuclear Information System (INIS)

    Fazio, C.; Serra, E.; Benamati, G.

    1999-01-01

    Results on the fabrication of a tritium permeation barrier by spraying Fe-Cr-Al powders are described. The sprayed coatings were deposited at temperatures below the A c1 temperature of the ferritic-martensitic steel substrate and no post-deposition heat treatment was applied. The aim of the investigation was the determination of the efficiency of the coatings to act as tritium permeation barrier. Metallurgical investigations as well as hydrogen isotope permeation measurements were carried out onto the produced coatings. The depositions were performed on ferritic-martensitic steels by means of three types of spray techniques: high velocity oxy fuel, air plasma spray and vacuum plasma spray. (orig.)

  17. NMR experiments on ion permeation in irradiated model membranes

    International Nuclear Information System (INIS)

    Sprinz, H.; Winkler, E.; Schaefer, H.

    1981-01-01

    In aqueous solutions of egg-lecithin vesicles treated with ultrasonics the 1 H NMR parameters line width, area, and chemical shift of the signal of the (CH 3 ) 3 N + group were determined as a function of the gamma dose (0 ... 12 kGy). Using europium and the line shape analysis, it has been possible to calculate these parameters for the inside as well as for the outside lipid layer. Increasing 60 Co radiation dose leads to linear increases of the line widths, which are significantly more rapid for the outer than for the inner layer. From that it can be concluded that the outside lipid layer has been more damaged by irradiation. The asymmetry may be the consequence of a radiation effect induced by the radicals of water radiolysis. From the temporal changes of the NMR parameters information can be obtained about the radiation effect on transport processes in the vesicles. Beginning at a threshold (approx. 5 kGy) the permeation of Eu +++ ions to the (CH 3 ) 3 N + head groups, previously not accessible, increases significantly. (author)

  18. The influence of surface roughness on the hydrogen permeation of type API 5L-X52 steel

    International Nuclear Information System (INIS)

    Requiz, R.; Vera, N.; Camero, S.

    2004-01-01

    The influence of surface roughness on the corrosion and hydrogen permeation behaviour was evaluated on a type API 5L-52 steel in dearated 0.1M NaSO 4 at pH=2. Potentiodynamic polarization curves were employed to determine the electrochemical behaviour of the steel, while the Devanathan-Stachurski technique was used to estimate the hydrogen permeation rate. Additionally, the surface roughness profiles were obtained in order to correlate the changes in the hydrogen perkeation rate with different metal surface finishings. The obtained results clearly demonstrate that when the roughness parameters have larger values, the cathodic current of hydrogen evolution increases while the hydrogen entry rate decreases. This effect can be attributed to the microstructural defects induced at the steel surface, such as dislocations, which increase the catalytic activity of the atomic hydrogen favouring its recombination. Also, these defects could allow the atomic hydrogen to remain adsorbed on the steel surface. Both effects could hinder the hydrogen diffusion into the metal since the possibility for this atom of becoming absorbed has been reduced. (Author) 16 refs

  19. Mobility of supercooled liquid toluene, ethylbenzene, and benzene near their glass transition temperatures investigated using inert gas permeation.

    Science.gov (United States)

    May, R Alan; Smith, R Scott; Kay, Bruce D

    2013-11-21

    We investigate the mobility of supercooled liquid toluene, ethylbenzene, and benzene near their respective glass transition temperatures (Tg). The permeation rate of Ar, Kr, and Xe through the supercooled liquid created when initially amorphous overlayers are heated above their glass transition temperature is used to determine the diffusivity. Amorphous benzene crystallizes at temperatures well below its Tg, and as a result, the inert gas underlayer remains trapped until the onset of benzene desorption. In contrast, for toluene and ethylbenzene the onset of inert gas permeation is observed at temperatues near Tg. The inert gas desorption peak temperature as a function of the heating rate and overlayer thickness is used to quantify the diffusivity of supercooled liquid toluene and ethylbenzene from 115 to 135 K. In this temperature range, diffusivities are found to vary across 5 orders of magnitude (∼10(-14) to 10(-9) cm(2)/s). The diffusivity data are compared to viscosity measurements and reveal a breakdown in the Stokes-Einstein relationship at low temperatures. However, the data are well fit by the fractional Stokes-Einstein equation with an exponent of 0.66. Efforts to determine the diffusivity of a mixture of benzene and ethylbenzene are detailed, and the effect of mixing these materials on benzene crystallization is explored using infrared spectroscopy.

  20. Simple and Selective HPLC-UV/Vis Bioanalytical Method to Determine Aluminum Phthalocyanine Chloride in Skin Permeation Studies

    Directory of Open Access Journals (Sweden)

    Thaiene Avila Reis

    2018-01-01

    Full Text Available Considering the feasibility of the aluminum phthalocyanine chloride (AlPcCl application in the topical photodynamic therapy of cutaneous tumors and the lack of HPLC methods capable of supporting skin permeation experiments using this compound, the aim of this study was to obtain a simple and selective chromatographic method for AlPcCl determination in skin matrices. A HPLC-UV/Vis method was developed using a normal-phase column operating at 30°C, an isocratic mobile phase of methanol : phosphoric acid (0.01 M at 1.5 mL/min, and detection at 670 nm. The method exhibited (i selectivity against various contaminants found in the different skin layers, (ii high drug extraction capacity from the hair follicle (>70% and remaining skin (>80%, and (iii low limits of detection and of quantification (0.03 and 0.09 μg/mL, resp.. The method was also linear in the range from 0.1 to 5.0 µg/mL (r = 0.9994 and demonstrated robustness with regard to experimental chromatographic parameters according to a factorial design. Lastly, the developed method was successfully tested in in vitro skin permeation studies of AlPcCl, proving its effectiveness in the development of pharmaceutical delivery systems containing this drug for topical photodynamic therapy of skin cancers.

  1. In vitro profiling of the vaginal permeation potential of anti-HIV microbicides and the influence of formulation excipients.

    Science.gov (United States)

    Grammen, Carolien; Augustijns, Patrick; Brouwers, Joachim

    2012-11-01

    In the search for an effective anti-HIV microbicidal gel, limited drug penetration into the vaginal submucosa is a possible reason for failed protection against HIV transmission. To address this issue in early development, we here describe a simple in vitro strategy to predict the tissue permeation potential of vaginally applied drugs, based on solubility, permeability and flux assessment. We demonstrated this approach for four model microbicides (tenofovir, darunavir, saquinavir mesylate and dapivirine) and additionally examined the influence of formulation excipients on the permeation potential. When formulated in an aqueous-based HEC gel, high flux values across an HEC-1A cell layer were reached by tenofovir, as a result of its high aqueous solubility. In contrast, saquinavir and dapivirine fluxes remained low due to poor permeability and solubility, respectively. These low fluxes suggest limited in vivo tissue penetration, possibly leading to lack of efficacy. Dapivirine fluxes, however, could be enhanced up to 30-fold, by including formulation excipients such as polyethylene glycol 1000 (20%) or cyclodextrins (5%) in the HEC gels. Alternative formulations, i.e. emulsions or silicone elastomer gels, were less effective in flux enhancement compared to cyclodextrin-HEC gels. In conclusion, implementing the proposed solubility and permeability profiling in early microbicide development may contribute to the successful selection of promising microbicide candidates and appropriate formulations. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Decomposition Technique for Remaining Useful Life Prediction

    Science.gov (United States)

    Saha, Bhaskar (Inventor); Goebel, Kai F. (Inventor); Saxena, Abhinav (Inventor); Celaya, Jose R. (Inventor)

    2014-01-01

    The prognostic tool disclosed here decomposes the problem of estimating the remaining useful life (RUL) of a component or sub-system into two separate regression problems: the feature-to-damage mapping and the operational conditions-to-damage-rate mapping. These maps are initially generated in off-line mode. One or more regression algorithms are used to generate each of these maps from measurements (and features derived from these), operational conditions, and ground truth information. This decomposition technique allows for the explicit quantification and management of different sources of uncertainty present in the process. Next, the maps are used in an on-line mode where run-time data (sensor measurements and operational conditions) are used in conjunction with the maps generated in off-line mode to estimate both current damage state as well as future damage accumulation. Remaining life is computed by subtracting the instance when the extrapolated damage reaches the failure threshold from the instance when the prediction is made.

  3. Thiolated hydroxyethyl cellulose: design and in vitro evaluation of mucoadhesive and permeation enhancing nanoparticles.

    Science.gov (United States)

    Rahmat, Deni; Müller, Christiane; Barthelmes, Jan; Shahnaz, Gul; Martien, Ronny; Bernkop-Schnürch, Andreas

    2013-02-01

    Within this study, HEC-cysteamine nanoparticles with free thiol groups in the range of 117-1548 μmol/g were designed and characterized. Nanoparticles were generated via ionic gelation of the cationic polymer with tripolyphosphate (TPP) followed by covalent crosslinking via disulfide bond formation using H2O2 as oxidant. The mean diameter of the particles was in the range of 270-360 nm, and zeta potential was determined to be +4 to +10 mV. Nanoparticles were evaluated in terms of mucoadhesive, permeation enhancing, and biocompatible properties as well as biodegradability. The particles remained attached to porcine intestinal mucosa up to 70% after 3h of incubation. The more nanoparticles were oxidized; however, the less were their mucoadhesive properties. Nanoparticles applied in a concentration of 0.5% (m/v) with the highest content of free thiol groups improved the transport of fluorescein isothiocyanate dextran 4 (FD4) across Caco-2 cell monolayer 3.94-fold in comparison with control (buffer). In addition, the transport of FD4 was even 1.84-fold enhanced in the presence of 0.5% (m/v) nanoparticles with the lowest free thiol group content. The higher the disulfide bond content within nanoparticles was, to a lower degree nanoparticles were hydrolyzed by cellulase. None of these nanoparticles showed pronounced cytotoxicity. Accordingly, HEC-cysteamine could be a promising excipient for nanoparticulate delivery systems for poorly absorbed drugs. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Functional electrical stimulation cycling does not improve mobility in people with acquired brain injury and its effects on strength are unclear: a randomised trial

    Directory of Open Access Journals (Sweden)

    Davide G de Sousa

    2016-10-01

    Full Text Available Question: Does 4 weeks of active functional electrical stimulation (FES cycling in addition to usual care improve mobility and strength more than usual care alone in people with a sub-acute acquired brain injury caused by stroke or trauma? Design: Multi centre, randomised, controlled trial. Participants: Forty patients from three Sydney hospitals with recently acquired brain injury and a mean composite strength score in the affected lower limb of 7 (SD 5 out of 20 points. Intervention: Participants in the experimental group received an incremental, progressive, FES cycling program five times a week over a 4-week period. All participants received usual care. Outcome measures: Outcome measures were taken at baseline and at 4 weeks. Primary outcomes were mobility and strength of the knee extensors of the affected lower limb. Mobility was measured with three mobility items of the Functional Independence Measure and strength was measured with a hand-held dynamometer. Secondary outcomes were strength of the knee extensors of the unaffected lower limb, strength of key muscles of the affected lower limb and spasticity of the affected plantar flexors. Results: All but one participant completed the study. The mean between-group differences for mobility and strength of the knee extensors of the affected lower limb were –0.3/21 points (95% CI –3.2 to 2.7 and 7.5 Nm (95% CI –5.1 to 20.2, where positive values favoured the experimental group. The only secondary outcome that suggested a possible treatment effect was strength of key muscles of the affected lower limb with a mean between-group difference of 3.0/20 points (95% CI 1.3 to 4.8. Conclusion: Functional electrical stimulation cycling does not improve mobility in people with acquired brain injury and its effects on strength are unclear. Trial registration: ACTRN12612001163897. [de Sousa DG, Harvey LA, Dorsch S, Leung J, Harris W (2016 Functional electrical stimulation cycling does not improve

  5. Shotgun microbial profiling of fossil remains

    DEFF Research Database (Denmark)

    Der Sarkissian, Clio; Ermini, Luca; Jónsson, Hákon

    2014-01-01

    the specimen of interest, but instead reflect environmental organisms that colonized the specimen after death. Here, we characterize the microbial diversity recovered from seven c. 200- to 13 000-year-old horse bones collected from northern Siberia. We use a robust, taxonomy-based assignment approach...... to identify the microorganisms present in ancient DNA extracts and quantify their relative abundance. Our results suggest that molecular preservation niches exist within ancient samples that can potentially be used to characterize the environments from which the remains are recovered. In addition, microbial...... community profiling of the seven specimens revealed site-specific environmental signatures. These microbial communities appear to comprise mainly organisms that colonized the fossils recently. Our approach significantly extends the amount of useful data that can be recovered from ancient specimens using...

  6. Some remaining problems in HCDA analysis

    International Nuclear Information System (INIS)

    Chang, Y.W.

    1981-01-01

    The safety assessment and licensing of liquid-metal fast breeder reactors (LMFBRs) requires an analysis on the capability of the reactor primary system to sustain the consequences of a hypothetical core-disruptive accident (HCDA). Although computational methods and computer programs developed for HCDA analyses can predict reasonably well the response of the primary containment system, and follow up the phenomena of HCDA from the start of excursion to the time of dynamic equilibrium in the system, there remain areas in the HCDA analysis that merit further analytical and experimental studies. These are the analysis of fluid impact on reactor cover, three-dimensional analysis, the treatment of the perforated plates, material properties under high strain rates and under high temperatures, the treatment of multifield flows, and the treatment of prestressed concrete reactor vessels. The purpose of this paper is to discuss the structural mechanics of HCDA analysis in these areas where improvements are needed

  7. Political, energy events will remain interwoven

    International Nuclear Information System (INIS)

    Jones, D.P.

    1991-01-01

    This paper reports that it is possible to discuss the significance of political and energy events separately, but, in truth, they are intricately interwoven. Furthermore, there are those who will argue that since the two are inseparable, the future is not predictable; so why bother in the endeavor. It is possible that the central point of the exercise may have been missed-yes, the future is unpredictable exclamation point However, the objective of prediction is secondary. The objective of understanding the dynamic forces of change is primary exclamation point With this view of recent history, it is perhaps appropriate to pause and think about the future of the petroleum industry. The future as shaped by political, energy, economic, environmental and technological forces will direct our lives and markets during this decade. Most importantly, what will be the direction that successful businesses take to remain competitive in a global environment? These are interesting issues worthy of provocative thoughts and innovative ideas

  8. Nuclear remains an economic and ecologic asset

    International Nuclear Information System (INIS)

    Le Ngoc, Boris

    2015-01-01

    The author herein outlines the several benefits of nuclear energy and nuclear industry for France. He first outlines that France possesses 97 per cent of de-carbonated electricity thanks to nuclear energy (77 pc) and renewable energies (20 pc, mainly hydraulic), and that renewable energies must be developed in the building and transport sectors to be able to get rid of the environmentally and financially costly fossil energies. He outlines that reactor maintenance and the nuclear fuel cycle industry are fields of technological leadership for the French nuclear industry which is, after motor industry and aircraft industry, the third industrial sector in France. He indicates that nuclear electricity is to remain the most competitive one, and that nuclear energy and renewable energies must not be opposed to it but considered as complementary in the struggle against climate change, i.e. to reduce greenhouse gas emissions and to get rid of the prevalence of fossil energies

  9. Population cycles: generalities, exceptions and remaining mysteries

    Science.gov (United States)

    2018-01-01

    Population cycles are one of nature's great mysteries. For almost a hundred years, innumerable studies have probed the causes of cyclic dynamics in snowshoe hares, voles and lemmings, forest Lepidoptera and grouse. Even though cyclic species have very different life histories, similarities in mechanisms related to their dynamics are apparent. In addition to high reproductive rates and density-related mortality from predators, pathogens or parasitoids, other characteristics include transgenerational reduced reproduction and dispersal with increasing-peak densities, and genetic similarity among populations. Experiments to stop cyclic dynamics and comparisons of cyclic and noncyclic populations provide some understanding but both reproduction and mortality must be considered. What determines variation in amplitude and periodicity of population outbreaks remains a mystery. PMID:29563267

  10. Permeation of hydrogen at low pressures through stainless steel and implications for tritium control in fusion reactor systems

    International Nuclear Information System (INIS)

    Axtmann, R.C.; Johnson, E.F.; Kuehler, C.W.

    1976-01-01

    New experimental data on the permeation of hydrogen through stainless steel indicate that at driving pressures below 10 -2 torr, the permeation rate is linearly dependent on the driving pressure. A possible consequence is that the permeation rates of hydrogenic species in fusion reactor systems might be much lower than those reported in contemporary conceptual design studies which assume that the rates are dependent on the square root of the driving pressure. The important implications of these low permeation rates are: (1) tritium losses to the environment may be more dependent on ordinary leaks from equipment than on permeation to the steam cycle; (2) recovery of tritium from breeding blankets via permeation windows may be impracticable; and (3) recovery of tritium from breeding blankets not dependent on permeation windows may be simplified by the possibility of operating at much higher average tritium concentrations in the blanket and cooling systems

  11. Experimental evaluation of tritium permeation through stainless steel tubes of heat exchanger from primary to secondary water in ITER

    International Nuclear Information System (INIS)

    Nakamura, Hirofumi; Nishi, Masataka

    2004-01-01

    Tritium permeation through heat exchanger from primary cooling water to secondary cooling water has been investigated experimentally with SS316L heat exchanger under simulated ITER (international thermonuclear experimental reactor) operation condition in order to establish the tritium permeation evaluation method through the heat exchanger. As the result, the permeation rate of aqueous tritium was found to be about three orders smaller than that of the gaseous tritium. Tritium permeation through the heat exchanger in ITER was then evaluated, and it was revealed that total tritium permeation amount based on obtained aqueous permeability was about one order less than that with the former method with the gaseous permeability and putting the permeation reduction factor as 1000. Evaluated tritium permeation amount into secondary water during 20 years was quite small, which could be considered as negligible from the safety viewpoint

  12. Does hypertension remain after kidney transplantation?

    Directory of Open Access Journals (Sweden)

    Gholamreza Pourmand

    2015-05-01

    Full Text Available Hypertension is a common complication of kidney transplantation with the prevalence of 80%. Studies in adults have shown a high prevalence of hypertension (HTN in the first three months of transplantation while this rate is reduced to 50- 60% at the end of the first year. HTN remains as a major risk factor for cardiovascular diseases, lower graft survival rates and poor function of transplanted kidney in adults and children. In this retrospective study, medical records of 400 kidney transplantation patients of Sina Hospital were evaluated. Patients were followed monthly for the 1st year, every two months in the 2nd year and every three months after that. In this study 244 (61% patients were male. Mean ± SD age of recipients was 39.3 ± 13.8 years. In most patients (40.8% the cause of end-stage renal disease (ESRD was unknown followed by HTN (26.3%. A total of 166 (41.5% patients had been hypertensive before transplantation and 234 (58.5% had normal blood pressure. Among these 234 individuals, 94 (40.2% developed post-transplantation HTN. On the other hand, among 166 pre-transplant hypertensive patients, 86 patients (56.8% remained hypertensive after transplantation. Totally 180 (45% patients had post-transplantation HTN and 220 patients (55% didn't develop HTN. Based on the findings, the incidence of post-transplantation hypertension is high, and kidney transplantation does not lead to remission of hypertension. On the other hand, hypertension is one of the main causes of ESRD. Thus, early screening of hypertension can prevent kidney damage and reduce further problems in renal transplant recipients.

  13. Alteration of skin hydration and its barrier function by vehicle and permeation enhancers: a study using TGA, FTIR, TEWL and drug permeation as markers.

    Science.gov (United States)

    Shah, D K; Khandavilli, S; Panchagnula, R

    2008-09-01

    Vehicles and permeation enhancers (PEs) used in transdermal drug delivery (TDD) of a drug can affect skin hydration, integrity and permeation of the solute administered. This investigation was designed to study the effect of the most commonly used vehicles and PEs on rat skin hydration, barrier function and permeation of an amphiphilic drug, imipramine hydrochloride (IMH). An array of well-established techniques were used to confirm the findings of the study. Thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy were used to determine changes in skin hydration. Alteration of the stratum corneum (SC) structure was investigated using FTIR studies. To monitor the barrier function alteration, transepidermal water loss (TEWL) measurement and permeation studies were performed. Our findings indicate that with hydration, there was an increase in the bound water content of the skin, and pseudoequilibrium of hydration (a drastic decrease in hydration rate) was achieved at around 12 h. Hydration increased the ratio between amide-I and amide-II peaks in FTIR and reduced the C-H stretching peak area. Both propylene glycol (PG) and ethanol (EtOH) dehydrated skin, with the latter showing a predominant effect. Furthermore, it was confirmed that PG and EtOH decreased the bound water content due to alteration in the protein domains and extraction of SC lipids, respectively. The effect of hydration on the SC was found to be similar to that reported for temperature. Permeation studies revealed that the dehydration caused by vehicles decreased IMH flux, whereas the flux was enhanced by PEs. The role of partition was predominant for the permeation of IMH through dehydrated skin. A synergistic effect was observed for PG and menthol in the enhancement of IMH. Further findings provided strong evidence that PG affects protein domains and EtOH extracts lipids from the bilayer. Both PG and EtOH, with or without PEs, increased TEWL. Initial TEWL was well

  14. Tritium permeation through helium-heated steam generators of ceramic breeder blankets for DEMO

    International Nuclear Information System (INIS)

    Fuetterer, M.A.; Raepsaet, X.; Proust, E.

    1994-01-01

    The specifications of permeation barriers, tritium recovery process maintaining a very low tritium activity in the coolant, and control of the coolant chemistry, required the evaluation of the tritium losses through the steam generators and include the definition of its operating conditions by thermodynamic cycle calculations and its thermal-hydraulic design. For both tasks specific computer tools were developed. The obtained geometry, surface area, and temperature profiles along the heat exchanger tubes were then used to estimate the daily tritium permeation into the steam cycle. Steam oxidized Incoloy 800 austenitic stainless steel was identified as the best suited existing material; in nominal steady-state operation, the tritium escape into the steam cycle could be restricted to less than 10 Ci/d. Tritium permeation during temperature and pressure transients in the steam generator (destruction and possible self-healing of the permeation barrier) is identified to bear a large tritium release potential. Solutions are proposed. (from authors). 4 figs., 1 tab

  15. Tritium permeation through helium-heated steam generators of ceramic breeder blankets for DEMO

    Energy Technology Data Exchange (ETDEWEB)

    Fuetterer, M A; Raepsaet, X; Proust, E

    1994-12-31

    The specifications of permeation barriers, tritium recovery process maintaining a very low tritium activity in the coolant, and control of the coolant chemistry, required the evaluation of the tritium losses through the steam generators and include the definition of its operating conditions by thermodynamic cycle calculations and its thermal-hydraulic design. For both tasks specific computer tools were developed. The obtained geometry, surface area, and temperature profiles along the heat exchanger tubes were then used to estimate the daily tritium permeation into the steam cycle. Steam oxidized Incoloy 800 austenitic stainless steel was identified as the best suited existing material; in nominal steady-state operation, the tritium escape into the steam cycle could be restricted to less than 10 Ci/d. Tritium permeation during temperature and pressure transients in the steam generator (destruction and possible self-healing of the permeation barrier) is identified to bear a large tritium release potential. Solutions are proposed. (from authors). 4 figs., 1 tab.

  16. Toward enhanced hydrogen generation from water using oxygen permeating LCF membranes

    KAUST Repository

    Wu, Xiao-Yu; Chang, Le; Uddi, Mruthunjaya; Kirchen, Patrick; Ghoniem, Ahmed F.

    2015-01-01

    and flow rates on the feed and sweep sides on the water thermolysis rate and oxygen flux. A single step reaction mechanism is proposed for surface reactions, and three-resistance permeation models are derived. Results show that water thermolysis

  17. Experimental Validation of Hybrid Distillation-Vapor Permeation Process for Energy Efficient Ethanol-Water Separation

    Science.gov (United States)

    The energy demand of distillation-based systems for ethanol recovery and dehydration can be significant, particularly for dilute solutions. An alternative separation process integrating vapor stripping with a vapor compression step and a vapor permeation membrane separation step,...

  18. Formation of permeation barriers on ceramic SiC/SiC composites

    International Nuclear Information System (INIS)

    Racault, C.; Fenici, P.

    1996-01-01

    The effectiveness as permeation barriers of the following CVD and PVD (sputtering) coatings has been investigated: TiC+Al 2 O 3 (CVD), SiC(CVD), SiO 2 (CVD), TiN(CVD), TiN(CVD)+TiN(PVD) and SiC(CVD)+Al 2 O 3 (PVD). The substrate material was a SiC/SiC composite, proposed as low activation structural material for fusion applications. Permeation measurements were performed in the temperature range 300-750 K using deuterium at pressures in the range 0.5-150 kPa. A linear dependence of permeation rate on pressure was measured. The efficiency of the coatings as deuterium permeation barriers is discussed in terms of coating microstructure. The best result was obtained with a bilayer of TiN(CVD) (15 μm) +TiN(PVD) (8 μm). (orig.)

  19. Tritium permeation barriers in contact with liquid lithium-lead eutectic (Pb-17Li)

    International Nuclear Information System (INIS)

    Forcey, K.S.; Perujo, A.

    1995-01-01

    The permeation of deuterium through coated stainless steel tubes containing liquid lithium-lead eutectic (Pb-17Li) has been studied and compared to measurements through tubes without the lithium compound. The measurements form part of an investigation into the effect of a potential tritium breeder material on permeation barriers for fusion reactors. The coatings studied were CVD TiC and Al 2 O 3 and a pack aluminised layer. Without the lithium-lead, the CVD coatings reduced the permeation rate up to 1 order of magnitude, and the aluminised layer up to 2 orders of magnitude. A CVD layer was unaffected by Pb-17Li whilst in the case of the aluminised tube, the lithium-lead completely removed the permeation barrier, presumably by attacking the surface oxide. Furthermore, the aluminised sample presented a large number of cracks and poor adheren ce to the substrate. ((orig.))

  20. Water vapor permeation and dehumidification performance of poly(vinyl alcohol)/lithium chloride composite membranes

    KAUST Repository

    Bui, Duc Thuan; Nida, Aqdas; Ng, Kim  Choon; Chua, Kian  Jon

    2015-01-01

    were observed for membranes with increased lithium chloride content up to 50%. The permeation and sorption properties of the membranes were investigated under different temperatures. The results provided a deeper insight into the membrane water vapor

  1. Water vapor permeation and dehumidification performance of poly(vinyl alcohol)/lithium chloride composite membranes

    KAUST Repository

    Bui, Duc Thuan

    2015-10-09

    Thin and robust composite membranes comprising stainless steel scaffold, fine and porous TiO2 and polyvinyl alcohol/lithium chloride were fabricated and studied for air dehumidification application. Higher hydrophilicity, sorption and permeation were observed for membranes with increased lithium chloride content up to 50%. The permeation and sorption properties of the membranes were investigated under different temperatures. The results provided a deeper insight into the membrane water vapor permeation process. It was specifically noted that lithium chloride significantly reduces water diffusion energy barrier, resulting in the change of permeation energy from positive to negative values. Higher water vapor permeance was observed for the membrane with higher LiCl content at lower temperature. The isothermal air dehumidification tests show that the membrane is suitable for dehumidifying air in high humid condition. Additionally, results also indicate a trade-off between the humidity ratio drop with the water vapor removal rate when varying air flowrate.

  2. Determination of trapping parameters and the chemical diffusion coefficient from hydrogen permeation experiments

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Jiří; Mori, G.; Prethaler, A.; Fischer, F. D.

    2014-01-01

    Roč. 82, MAY (2014), s. 93-100 ISSN 0010-938X Institutional support: RVO:68081723 Keywords : Steel * Electrochemical calculation * Modeling studies * Hydrogen permeation * Kinetic parameters Subject RIV: BJ - Thermodynamics Impact factor: 4.422, year: 2014

  3. Ion-driven permeation of deuterium through tungsten under simultaneous helium and deuterium irradiation

    International Nuclear Information System (INIS)

    Lee, H.T.; Tanaka, H.; Ohtsuka, Y.; Ueda, Y.

    2011-01-01

    Ion-driven permeation of D through tungsten under simultaneous irradiation with He-D was measured as a function of temperature, flux, and energy. He reduced the permeation flux with the reduction increasing with decreasing temperature. The reduction in permeation flux followed a linear dependence to the incident flux at T > 1000 K, but shifted to a square root dependence at T < 1000 K. The results were interpreted as shifts from diffusion limited to recombination limited H transport according to Doyle and Brice's theory. Arrhenius functions of front diffusivity and recombination coefficients were derived and used to calculate the transport parameter W. The effect of He can be interpreted as changes to the front diffusivity that approaches H diffusion behavior in the absence of traps. The reduction in total concentration results in a shallower concentration gradient that can describe the observed decrease in permeation.

  4. The impact of tritium solubility and diffusivity on inventory and permeation in liquid breeder blankets

    International Nuclear Information System (INIS)

    Caorlin, M.; Gervasini, G.; Reiter, F.

    1988-01-01

    The authors reviewed hydrogen solubility and diffusivity data for liquid lithium-based compounds which are potential breeding blanket materials in NET-type fusion devices. These data have been used to assess tritium permeation and inventory in separately cooled NET blankets and in self cooled blankets with a vanadium first wall. The results for the separately cooled NET-liquid breeder show that tritium permeation is negligible for lithium, a serious problem for Pb-17Li and a critical one for Flibe. The total tritium inventory is lowest in lithium, high in Pb-17Li and very high in Flibe. The high tritium partial pressure for Flibe or Pb-17Li can be reduced in a self cooled blanket with a vanadium first wall. Permeation into the plasma reduces the blanket tritium inventory and permeation. Tritium recovery can be combined with the plasma exhaust

  5. Permeation of macromolecules into the renal glomerular basement membrane and capture by the tubules

    Science.gov (United States)

    Lawrence, Marlon G.; Altenburg, Michael K.; Sanford, Ryan; Willett, Julian D.; Bleasdale, Benjamin; Ballou, Byron; Wilder, Jennifer; Li, Feng; Miner, Jeffrey H.; Berg, Ulla B.; Smithies, Oliver

    2017-01-01

    How the kidney prevents urinary excretion of plasma proteins continues to be debated. Here, using unfixed whole-mount mouse kidneys, we show that fluorescent-tagged proteins and neutral dextrans permeate into the glomerular basement membrane (GBM), in general agreement with Ogston's 1958 equation describing how permeation into gels is related to molecular size. Electron-microscopic analyses of kidneys fixed seconds to hours after injecting gold-tagged albumin, negatively charged gold nanoparticles, and stable oligoclusters of gold nanoparticles show that permeation into the lamina densa of the GBM is size-sensitive. Nanoparticles comparable in size with IgG dimers do not permeate into it. IgG monomer-sized particles permeate to some extent. Albumin-sized particles permeate extensively into the lamina densa. Particles traversing the lamina densa tend to accumulate upstream of the podocyte glycocalyx that spans the slit, but none are observed upstream of the slit diaphragm. At low concentrations, ovalbumin-sized nanoparticles reach the primary filtrate, are captured by proximal tubule cells, and are endocytosed. At higher concentrations, tubular capture is saturated, and they reach the urine. In mouse models of Pierson’s or Alport’s proteinuric syndromes resulting from defects in GBM structural proteins (laminin β2 or collagen α3 IV), the GBM is irregularly swollen, the lamina densa is absent, and permeation is increased. Our observations indicate that size-dependent permeation into the lamina densa of the GBM and the podocyte glycocalyx, together with saturable tubular capture, determines which macromolecules reach the urine without the need to invoke direct size selection by the slit diaphragm. PMID:28246329

  6. Acquisition of Preparative Gel Permeation Chromatography for Research and Education in Energy Conversion and Nanocomposites

    Science.gov (United States)

    2017-04-19

    AFRL-AFOSR-VA-TR-2017-0090 Acquisition of Preparative Gel Permeation Chromatography for Research and Education in Energy Conversion and...TITLE AND SUBTITLE Acquisition of Preparative Gel Permeation Chromatography for Research and Education in Energy Conversion and Nanocomposites 5a... research with education at all levels across a broad range of materials, and create important opportunities to expose and train undergraduates, women

  7. Financial Permeation and Economic Growth: Evidence from Sub-Saharan Africa

    OpenAIRE

    Inoue, Takeshi; Hamori, Shigeyuki

    2013-01-01

    This article empirically analyzes the role of finance in economic growth in Sub-Saharan Africa from the perspective of what is termed herein “financial permeation”. By estimating panel data on 37 countries in Sub-Saharan Africa between 2004 and 2010, we examine whether financial permeation through improved convenience and access to financial services has contributed to economic growth in this region. Empirical results clearly indicate that financial permeation has a statistically significant ...

  8. Catalytic reforming of methane to syngas in an oxygen-permeative membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    Urano, Takeshi; Kubo, Keiko; Saito, Tomoyuki; Hitomi, Atsushi, E-mail: turano@jp.tdk.com [Materials and Process Development Center, TDK Corporation 570-2, Matsugashita, Minamihatori, Narita, Chiba 286-8588 (Japan)

    2011-05-15

    For fuel cell applications, partial oxidative reforming of methane to syngas, hydrogen and carbon monoxide, was performed via a dense oxygen-permeative ceramic membrane composed by both ionic and electronic conductive materials. The modification of Ni-based catalyst by noble metals was investigated to increase oxygen permeation flux and decrease carbon deposition during reforming reaction. The role of each component in catalyst was also discussed.

  9. Tritium permeation evaluation through vertical target of divertor based on recent tritium transport properties

    International Nuclear Information System (INIS)

    Nakamura, Hirofumi; Nishi, Masataka

    2003-11-01

    Re-evaluation of tritium permeation through vertical target of divertor under the ITER operation condition was carried out using tritium properties in the candidate materials such as the diffusion coefficient and the trapping factors in tungsten for armor, and the surface recombination coefficient on copper for the heat sink obtained by authours' recent investigation (authors' data), which simulated the plasma-facing conditions of ITER. Evaluation with the data set of previous evaluation was also carried out for comparison (previous data). The permeation analysis was carried out individually by classifying into the armor region (Carbon Fiber Composites and tungsten) and the slit region without armor (3% of armor surface area) assuming the incident flux and temperature for each region. As the results of the permeation analysis, estimated permeation amount with the authors' data was one order less than that with the previous data at the end of lifetime of the divertor due to authors' small diffusion coefficient of tritium in tungsten. It also indicated the possibility that permeation through the slit region of the armor tiles could dominate total permeation through the vertical target, since tritium permeation amount through tungsten armor with the authors' data was estimated to be reduced drastically smaller than that with the previous evaluation data. The result of a little tritium permeation amount through the vertical target with the authors' data ensured the conservatism of the current evaluation of tritium concentration in the primary cooling water in ITER divertor, as it indicated the possibility of direct drainage of the divertor primary cooling water. (author)

  10. Enrofloxacin Permeation Pathways across the Porin OmpC.

    Science.gov (United States)

    Prajapati, Jigneshkumar Dahyabhai; Solano, Carlos José Fernández; Winterhalter, Mathias; Kleinekathöfer, Ulrich

    2018-02-01

    In Gram-negative bacteria, the lack or quenching of antibiotic translocation across the outer membrane is one of the main factors for acquiring antibiotic resistance. An atomic-level comprehension of the key features governing the transport of drugs by outer-membrane protein channels would be very helpful in developing the next generation of antibiotics. In a previous study [ J. D. Prajapati et al. J. Chem. Theory Comput. 2017 , 13 , 4553 ], we characterized the diffusion pathway of a ciprofloxacin molecule through the outer membrane porin OmpC of Escherichia coli by combining metadynamics and a zero-temperature string method. Here, we evaluate the diffusion route through the OmpC porin for a similar fluoroquinolone, that is, the enrofloxacin molecule, using the previously developed protocol. As a result, it was found that the lowest-energy pathway was similar to that for ciprofloxacin; namely, a reorientation was required on the extracellular side with the carboxyl group ahead before enrofloxacin reached the constriction region. In turn, the free-energy basins for both antibiotics are located at similar positions in the space defined by selected reaction coordinates, and their affinity sites share a wide number of porin residues. However, there are some important deviations due to the chemical differences of these two drugs. On the one hand, a slower diffusion process is expected for enrofloxacin, as the permeation pathway exhibits higher overall energy barriers, mainly in the constriction region. On the other hand, enrofloxacin needs to replace some polar interactions in its affinity sites with nonpolar ones. This study demonstrates how minor chemical modifications can qualitatively affect the translocation mechanism of an antibiotic molecule.

  11. The Kinetics and the Permeation Properties of Piezo Channels.

    Science.gov (United States)

    Gnanasambandam, R; Gottlieb, P A; Sachs, F

    2017-01-01

    Piezo channels are eukaryotic, cation-selective mechanosensitive channels (MSCs), which show rapid activation and voltage-dependent inactivation. The kinetics of these channels are largely consistent across multiple cell types and different stimulation paradigms with some minor variability. No accessory subunits that associate with Piezo channels have been reported. They are homotrimers and each ∼300kD monomer has an N-terminal propeller blade-like mechanosensing module, which can confer mechanosensing capabilities on ASIC-1 (the trimeric non-MSC, acid-sensing ion channel-1) and a C-terminal pore module, which influences conductance, selectivity, and channel inactivation. Repeated stimulation can cause domain fracture and diffusion of these channels leading to synchronous loss of inactivation. The reconstituted channels spontaneously open only in asymmetric bilayers but lack inactivation. Mutations that cause hereditary xerocytosis alter PIEZO1 kinetics. The kinetics of the wild-type PIEZO1 and alterations thereof in mutants (M2225R, R2456K, and DhPIEZO1) are summarized in the form of a quantitative model and hosted online. The pore is permeable to alkali ions although Li + permeates poorly. Divalent cations, notably Ca 2+ , traverse the channel and inhibit the flux of monovalents. The large monovalent organic cations such as tetramethyl ammonium and tetraethyl ammonium can traverse the channel, but slowly, suggesting a pore diameter of ∼8Å, and the estimated in-plane area change upon opening is around 6-20nm 2 . Ruthenium red can enter the channel only from the extracellular side and seems to bind in a pocket close to residue 2496. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. A comparison of implantation-driven permeation characteristics of fusion reactor structural materials

    Science.gov (United States)

    Longhurst, G. R.; Anderl, R. A.; Struttmann, D. A.

    1986-11-01

    Implantation-driven permeation experiments have been conducted on samples of the ferritic steel HT-9, the austenitic Primary Candidate Alloy (PCA) and the vanadium alloy V-15Cr-5Ti using D 3+ ions under conditions that simulate charge-exchange neutral loading on a fusion reactor first wall. The steels all exhibited an initially intense permeation "spike" followed by an exponential decrease to low steady-state values. That spike was not evident in the V-15Cr-5Ti experiments. Steady-state permeation was highest in the vanadium alloy and lowest in the austenitic steel. Though permeation rates in the HT-9 were lower than those in V-15Cr-5Ti, permeation transients were much faster in HT-9 than in other materials tested. Sputtering of the steel surface resulted in enhanced reemission, whereas in the vanadium tests, recombination and diffusivity both appeared to diminish as the deuterium concentration rose. We conclude that for conditions comparable to those of these experiments, tritium retention and permeation loss in first wall structures made of steels will be less than in structures made of V-15Cr-5Ti.

  13. Comparison on implantation-driven permeation characteristics of fusion reactor structural materials

    Energy Technology Data Exchange (ETDEWEB)

    Longhurst, G.R.; Anderl, R.A.; Struttmann, D.A. (Idaho National Engineering Lab., Idaho Falls)

    Implantation-driven permeation experiments have been conducted on samples of the ferritic steel HT-9, the austenitic Primary Candidate Alloy (PCA) and the vanadium alloy V-15Cr-5Ti using D{sub 3}{sup +} ions under conditions that simulate charge-exchange neutral loading on a fusion reactor first wall. The steels all exhibited an initially intense permeation spike followed by an exponential decrease to low steady-state values. That spike was not evident in the V-15Cr-5Ti experiments. Steady-state permeation was highest in the vanadium alloy and lowest in the austenitic steel. Though permeation rates in the HT-9 were lower than those in V-15Cr-5Ti, permeation transients were much faster in HT-9 than in other materials tested. Sputtering of the steel surface resulted in enhanced reemission, whereas in the vanadium tests, recombination and diffusivity both appeared to diminish as the deuterium concentration rose. We conclude that for conditions comparable to those of these experiments, tritium retention and permeation loss in first wall structures made of steels will be less than in structures made of V-15Cr-5Ti.

  14. Effects of Vehicles and Enhancers on the Skin Permeation of Phytoestrogenic Diarylheptanoids from Curcuma comosa.

    Science.gov (United States)

    Tuntiyasawasdikul, Sarunya; Limpongsa, Ekapol; Jaipakdee, Napaphak; Sripanidkulchai, Bungorn

    2017-04-01

    Curcuma comosa (C. comosa) is widely used in traditional medicine as a dietary supplement for health promotion in postmenopausal women in Thailand. It contains several diarylheptanoids, which are considered to be a novel class of phytoestrogens. However, the diarylheptanoids isolated from the plant rhizome are shown to have low oral bioavailability and faster elimination characteristics. The aim of this study was to investigate the permeation behavior of the active compounds of diarylheptanoids. The effects of binary vehicle systems and permeation enhancers on diarylheptanoids permeation and accumulation within the skin were studied using side-by-side diffusion cells through the porcine ear skin. Among the tested binary vehicle systems, the ethanol/water vehicle appeared to be the most effective system for diarylheptanoids permeation with the highest flux and shortest lag time. The presence of transcutol in the vehicle system significantly increased diarylheptanoid's permeation and accumulation within the skin in a concentration-dependent manner. Although the presence of terpenes in formulation decreased the flux of diarylheptanoids, it raised the amount of diarylheptanoids retained within the skin substantially. Based on the feasibility of diarylheptanoid permeation, C. comosa extract should be further developed into an effective transdermal product for health benefits and hormone replacement therapy.

  15. Compensation effect in H 2 permeation kinetics of PdAg membranes

    KAUST Repository

    Zeng, Gaofeng

    2012-08-30

    Knowledge about the (inter)dependence of permeation kinetic parameters on the stoichiometry of H 2-selective alloys is still rudimentary, although uncovering the underlying systematic correlations will greatly facilitate current efforts into the design of novel high-performance H 2 separation membranes. Permeation measurements with carefully engineered, 2-7 μm thick supported Pd 100-xAg x membranes reveal that the activation energy and pre-exponential factor of H 2 permeation laws vary systematically with alloy composition, and both kinetic parameters are strongly correlated for x ≤ 50. We show that this permeation kinetic compensation effect corresponds well with similar correlations in the hydrogen solution thermodynamics and diffusion kinetics of PdAg alloys that govern H 2 permeation rates. This effect enables the consistent description of permeation characteristics over wide temperature and alloy stoichiometry ranges, whereas hydrogen solution thermodynamics may play a role, too, as a yet unrecognized source of kinetic compensation in, for example, H 2-involving reactions over metal catalysts or hydrogenation/ dehydrogenation of hydrogen storage materials. © 2012 American Chemical Society.

  16. Enhanced skin permeation of naltrexone by pulsed electromagnetic fields in human skin in vitro.

    Science.gov (United States)

    Krishnan, Gayathri; Edwards, Jeffrey; Chen, Yan; Benson, Heather A E

    2010-06-01

    The aim of the present study was to evaluate the skin permeation of naltrexone (NTX) under the influence of a pulsed electromagnetic field (PEMF). The permeation of NTX across human epidermis and a silicone membrane in vitro was monitored during and after application of the PEMF and compared to passive application. Enhancement ratios of NTX human epidermis permeation by PEMF over passive diffusion, calculated based on the AUC of cumulative NTX permeation to the receptor compartment verses time for 0-4 h, 4-8 h, and over the entire experiment (0-8 h) were 6.52, 5.25, and 5.66, respectively. Observation of the curve indicated an initial enhancement of NTX permeation compared to passive delivery whilst the PEMF was active (0-4 h). This was followed by a secondary phase after termination of PEMF energy (4-8 h) in which there was a steady increase in NTX permeation. No significant enhancement of NTX penetration across silicone membrane occurred with PEMF application in comparison to passively applied NTX. In a preliminary experiment PEMF enhanced the penetration of 10 nm gold nanoparticles through the stratum corneum as visualized by multiphoton microscopy. This suggests that the channels through which the nanoparticles move must be larger than the 10 nm diameter of these rigid particles. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association

  17. Differential permeation of piroxicam-loaded PLGA micro/nanoparticles and their in vitro enhancement

    International Nuclear Information System (INIS)

    Shankarayan, Raju; Kumar, Sumit; Mishra, Prashant

    2013-01-01

    Piroxicam is a non-steroidal anti-inflammatory drug used for the treatment of musculoskeletal pain. The main problem encountered when piroxicam is administered orally is its gastric side-effect (ulcer, bleeding and holes in the stomach). Transmucosal delivery and encapsulation of piroxicam in biodegradable particles offer potential advantages over conventional oral delivery. The present study was aimed to develop an alternative to piroxicam-delivery which could overcome the direct contact of the drug at the mucosal membrane and its permeation through the mucosal membrane was studied. To achieve this, the piroxicam was encapsulated in Poly (lactide-co-glycolide) (PLGA) microparticles (size 1–4 μm, encapsulation efficiency 80–85 %) and nanoparticles (size 151.6 ± 28.6 nm, encapsulation efficiency 92.17 ± 3.08 %). Various formulation process parameters were optimised for the preparation of piroxicam-loaded PLGA nanoparticles of optimal size and encapsulation efficiency. Transmucosal permeability of piroxicam-loaded PLGA micro- and nanoparticles through the porcine oesophageal mucosa was studied. Using fluorescently labelled PLGA micro- and nanoparticles, size-dependent permeation was demonstrated. Furthermore, the effect of different permeation enhancers on the flux rate and permeability coefficient for the permeation of nanoparticles was investigated. The results suggested that amongst the permeation enhancers used the most efficient enhancement of permeation was observed with 10 mM sodium dodecyl sulphate.

  18. Differential permeation of piroxicam-loaded PLGA micro/nanoparticles and their in vitro enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Shankarayan, Raju; Kumar, Sumit; Mishra, Prashant, E-mail: pmishra@dbeb.iitd.ac.in [Indian Institute of Technology Delhi, Department of Biochemical Engineering and Biotechnology (India)

    2013-03-15

    Piroxicam is a non-steroidal anti-inflammatory drug used for the treatment of musculoskeletal pain. The main problem encountered when piroxicam is administered orally is its gastric side-effect (ulcer, bleeding and holes in the stomach). Transmucosal delivery and encapsulation of piroxicam in biodegradable particles offer potential advantages over conventional oral delivery. The present study was aimed to develop an alternative to piroxicam-delivery which could overcome the direct contact of the drug at the mucosal membrane and its permeation through the mucosal membrane was studied. To achieve this, the piroxicam was encapsulated in Poly (lactide-co-glycolide) (PLGA) microparticles (size 1-4 {mu}m, encapsulation efficiency 80-85 %) and nanoparticles (size 151.6 {+-} 28.6 nm, encapsulation efficiency 92.17 {+-} 3.08 %). Various formulation process parameters were optimised for the preparation of piroxicam-loaded PLGA nanoparticles of optimal size and encapsulation efficiency. Transmucosal permeability of piroxicam-loaded PLGA micro- and nanoparticles through the porcine oesophageal mucosa was studied. Using fluorescently labelled PLGA micro- and nanoparticles, size-dependent permeation was demonstrated. Furthermore, the effect of different permeation enhancers on the flux rate and permeability coefficient for the permeation of nanoparticles was investigated. The results suggested that amongst the permeation enhancers used the most efficient enhancement of permeation was observed with 10 mM sodium dodecyl sulphate.

  19. Differential permeation of piroxicam-loaded PLGA micro/nanoparticles and their in vitro enhancement

    Science.gov (United States)

    Shankarayan, Raju; Kumar, Sumit; Mishra, Prashant

    2013-03-01

    Piroxicam is a non-steroidal anti-inflammatory drug used for the treatment of musculoskeletal pain. The main problem encountered when piroxicam is administered orally is its gastric side-effect (ulcer, bleeding and holes in the stomach). Transmucosal delivery and encapsulation of piroxicam in biodegradable particles offer potential advantages over conventional oral delivery. The present study was aimed to develop an alternative to piroxicam-delivery which could overcome the direct contact of the drug at the mucosal membrane and its permeation through the mucosal membrane was studied. To achieve this, the piroxicam was encapsulated in Poly (lactide- co-glycolide) (PLGA) microparticles (size 1-4 μm, encapsulation efficiency 80-85 %) and nanoparticles (size 151.6 ± 28.6 nm, encapsulation efficiency 92.17 ± 3.08 %). Various formulation process parameters were optimised for the preparation of piroxicam-loaded PLGA nanoparticles of optimal size and encapsulation efficiency. Transmucosal permeability of piroxicam-loaded PLGA micro- and nanoparticles through the porcine oesophageal mucosa was studied. Using fluorescently labelled PLGA micro- and nanoparticles, size-dependent permeation was demonstrated. Furthermore, the effect of different permeation enhancers on the flux rate and permeability coefficient for the permeation of nanoparticles was investigated. The results suggested that amongst the permeation enhancers used the most efficient enhancement of permeation was observed with 10 mM sodium dodecyl sulphate.

  20. High permeation rates in liposome systems explain rapid glyphosate biodegradation associated with strong isotope fractionation.

    Science.gov (United States)

    Ehrl, Benno; Mogusu, Emmanuel O; Kim, Kyoungtea; Hofstetter, Heike; Pedersen, Joel A; Elsner, Martin

    2018-05-23

    Bacterial uptake of charged organic pollutants such as the widely used herbicide glyphosate is typically attributed to active transporters, whereas passive membrane permeation as an uptake pathway is usually neglected. For 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes, pH-dependent membrane permeation coefficients (Papp) of glyphosate, determined by nuclear magnetic resonance (NMR) spectroscopy, varied from Papp(pH 7.0) = 3.7 (+/-0.3) × 10-7 m∙s-1 to Papp(pH 4.1) = 4.2 (+/-0.1) × 10-6 m∙s-1. This surprisingly rapid membrane permeation depended on glyphosate speciation and was, at physiological pH, in the range of polar, non-charged molecules suggesting that passive membrane permeation is a potential uptake pathway during glyphosate biodegradation. To test this hypothesis, a Gram-negative glyphosate degrader, Ochrobactrum sp. FrEM, was isolated from glyphosate-treated soil and glyphosate permeation rates inferred from the liposome model were compared to bacterial degradation rates. Estimated maximum permeation rates were, indeed, two orders of magnitudes higher than glyphosate degradation rates. Moreover, biodegradation of millimolar glyphosate concentrations gave rise to pronounced carbon isotope fractionation with an apparent kinetic isotope effect of AKIEcarbon= 1.014 ± 0.003. This value is consistent with unmasked enzymatic isotope fractionation demonstrating that glyphosate biodegradation was little mass transfer-limited and glyphosate exchange across the cell membrane was rapid relative to enzymatic turnover.

  1. Hydrogen permeation modification of 4140 steel by ion nitriding with pulsed plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Bruzzoni, P.; Ortiz, M. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Bruehl, S.P.; Gomez, B.J.A.; Feugeas, J.N. [Inst. de Fisica Rosario (UNR-CONICET), Rosario (Argentina); Nosei, L. [Inst. de Mecanica Aplicada y Estructuras (UNR), Rosario (Argentina)

    1998-11-10

    It is widely known that the hydrogen in steel produces embrittlement. This effect may cause the failure of the elements (confining walls, mechanical parts, etc.) whose surfaces are in contact with this gas or with processes in which hydrogen is continuously generated. In this work it is shown that the ion nitriding of the surface of AISI 4140 is a good mechanism to act as a barrier against hydrogen permeation in its bulk. The ion nitriding was performed using a square wave DC glow discharge. The development of a compound layer of iron nitrides was observed as the cause of the hydrogen permeation reduction. For equal duration of treatment, thicker compound layers were developed in higher discharge/post-discharge ratios in the square wave of the applied voltage onto the sample (cathode), with a greater reduction of hydrogen permeation coefficient as a consequence. Nevertheless, the permeation was not reduced to zero in any of the treatment conditions used. The results of the analysis of the permeation tests and the image of the photomicrographs showed that the existence of cracks, fractures, failures, etc. in the compound layer (pre-existing in the AISI 4140 steel) could be the cause of the residual hydrogen permeation. This can be attributed to the movement of the hydrogen through these defects diffusing through the original {alpha}-Fe phase of the non-treated steel. (orig.) 11 refs.

  2. Skin permeation of D-limonene-based nanoemulsions as a transdermal carrier prepared by ultrasonic emulsification.

    Science.gov (United States)

    Lu, Wen-Chien; Chiang, Been-Huang; Huang, Da-Wei; Li, Po-Hsien

    2014-03-01

    Nanoemulsions can be used for transporting pharmaceutical phytochemicals in skin-care products because of their stability and rapid permeation properties. However, droplet size may be a critical factor aiding permeation through skin and transdermal delivery efficiency. We prepared D-limonene nanoemulsions with various droplet sizes by ultrasonic emulsification using mixed surfactants of sorbitane trioleate and polyoxyethylene (20) oleyl ether under different hydrophilic-lipophilic balance (HLB) values. Droplet size decreased with increasing HLB value. With HLB 12, the droplet size was 23 nm, and the encapsulated ratio peaked at 92.3%. Transmission electron microscopy revealed spherical droplets and the gray parts were D-limonene precipitation incorporated in spherical droplets of the emulsion system. Franz diffusion cell was used to evaluate the permeation of D-limonene nanoemulsion through rat abdominal skin; the permeation rate depended on droplet size. The emulsion with the lowest droplet size (54 nm) achieved the maximum permeation rate. The concentration of D-limonene in the skin was 40.11 μL/cm(2) at the end of 360 min. Histopathology revealed no distinct voids or empty spaces in the epidermal region of permeated rat skin, so the D-limonene nanoemulsion may be a safe carrier for transdermal drug delivery. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Crystallization and deuterium permeation behaviors of yttrium oxide coating prepared by metal organic decomposition

    Directory of Open Access Journals (Sweden)

    Takumi Chikada

    2016-12-01

    Full Text Available Yttrium oxide coatings were fabricated on reduced activation ferritic/martensitic steels by metal organic decomposition with a dip-coating technique, and their deuterium permeation behaviors were investigated. The microstructure of the coatings varied with heat-treatment temperature: amorphous at 670ºC (amorphous coating and crystallized at 700ºC (crystallized coating. Deuterium permeation flux of the amorphous coating was lower than the uncoated steel by a factor of 5 at 500ºC, while that of the crystallized coating was lower by a factor of around 100 at 400‒550ºC. The permeation fluxes of both coatings were drastically decreased during the measurements at higher temperatures by a factor of up to 790 for the amorphous coating and 1000 for the crystallized one, indicating a microstructure modification occurred by an effect of test temperature with hydrogen flux. Temperature dependence of deuterium diffusivity in the coatings suggests that the decrease of the permeation flux has been derived from a decrease of the diffusivity. Characteristic permeation behaviors were observed with different annealing conditions; however, they can be interpreted using the permeation mechanism clarified in the previous erbium oxide coating studies.

  4. Changes on iron electrode surface during hydrogen permeation in borate buffer solution

    International Nuclear Information System (INIS)

    Modiano, S.; Carreno, J.A.V.; Fugivara, C.S.; Torresi, R.M.; Vivier, V.; Benedetti, A.V.; Mattos, O.R.

    2008-01-01

    Hydrogen interaction with oxide films grown on iron electrodes at open circuit potential (E oc ) and in the passive region (+0.30 V ECS ) was studied by chronopotentiometry, chronoamperometry and electrochemical impedance spectroscopy techniques. The results were obtained in deaerated 0.3 mol L -1 H 3 BO 3 + 0.075 mol L -1 Na 2 B 4 O 7 (BB, pH 8.4) solution before, during and after hydrogen permeation. The iron oxide film modification was also investigated by means of in situ X-ray absorption near-edge spectroscopy (XANES) and scanning electrochemical microscopy (SECM) before and during hydrogen permeation. The main conclusion was that the passive film is reduced during the hydrogen diffusion. The hydrogen permeation stabilizes the iron surface at a potential close to the thermodynamic water stability line where hydrogen evolution can occur. The stationary condition required for the determination of the permeation parameters cannot be easily attained on iron surface during hydrogen permeation. Moreover, additional attention must be paid when obtaining the transport parameters using the classical permeation cell

  5. The Human Remains from HMS Pandora

    Directory of Open Access Journals (Sweden)

    D.P. Steptoe

    2002-04-01

    Full Text Available In 1977 the wreck of HMS Pandora (the ship that was sent to re-capture the Bounty mutineers was discovered off the north coast of Queensland. Since 1983, the Queensland Museum Maritime Archaeology section has carried out systematic excavation of the wreck. During the years 1986 and 1995-1998, more than 200 human bone and bone fragments were recovered. Osteological investigation revealed that this material represented three males. Their ages were estimated at approximately 17 +/-2 years, 22 +/-3 years and 28 +/-4 years, with statures of 168 +/-4cm, 167 +/-4cm, and 166cm +/-3cm respectively. All three individuals were probably Caucasian, although precise determination of ethnicity was not possible. In addition to poor dental hygiene, signs of chronic diseases suggestive of rickets and syphilis were observed. Evidence of spina bifida was seen on one of the skeletons, as were other skeletal anomalies. Various taphonomic processes affecting the remains were also observed and described. Compact bone was observed under the scanning electron microscope and found to be structurally coherent. Profiles of the three skeletons were compared with historical information about the 35 men lost with the ship, but no precise identification could be made. The investigation did not reveal the cause of death. Further research, such as DNA analysis, is being carried out at the time of publication.

  6. SMART POINT CLOUD: DEFINITION AND REMAINING CHALLENGES

    Directory of Open Access Journals (Sweden)

    F. Poux

    2016-10-01

    Full Text Available Dealing with coloured point cloud acquired from terrestrial laser scanner, this paper identifies remaining challenges for a new data structure: the smart point cloud. This concept arises with the statement that massive and discretized spatial information from active remote sensing technology is often underused due to data mining limitations. The generalisation of point cloud data associated with the heterogeneity and temporality of such datasets is the main issue regarding structure, segmentation, classification, and interaction for an immediate understanding. We propose to use both point cloud properties and human knowledge through machine learning to rapidly extract pertinent information, using user-centered information (smart data rather than raw data. A review of feature detection, machine learning frameworks and database systems indexed both for mining queries and data visualisation is studied. Based on existing approaches, we propose a new 3-block flexible framework around device expertise, analytic expertise and domain base reflexion. This contribution serves as the first step for the realisation of a comprehensive smart point cloud data structure.

  7. What remains of the Arrow oil?

    International Nuclear Information System (INIS)

    Sergy, G.; Owens, E.

    1993-01-01

    In February 1970, the tanker Arrow became grounded 6.5 km off the north shore of Chedabucto Bay, Nova Scotia, and nearly 72,000 bbl of Bunker C fuel oil were released from the vessel during its subsequent breakup and sinking. The oil was washed ashore in various degrees over an estimated 305 km of the bay's 604-km shoreline, of which only 48 km were cleaned. In addition, the tanker Kurdistan broke in two in pack ice in March 1979 in the Cabot Strait area, spilling ca 54,000 bbl of Bunker C, some of which was later found at 16 locations along the northeast and east shorelines of Chedabucto Bay. In summer 1992, a systematic ground survey of the bay's shorelines was conducted using Environment Canada Shoreline Cleanup Assessment Team (SCAT) procedures. Standard observations were made of oil distribution and width, thickness, and character of the oil residues in 419 coastal segments. Results from the survey are summarized. Oil was found to be present on 13.3 km of the shoreline, with heavy oiling restricted to 1.3 km primarily in the areas of Black Duck Cove and Lennox Passage. Some of this residual oil was identified as coming from the Arrow. Natural weathering processes account for removal of most of the spilled oil from the bay. Oil remaining on the shore was found in areas outside of the zone of physical wave action, in areas of nearshore mixing where fine sediments are not present to weather the oil through biophysical processes, or in crusts formed by oil weathered on the surface. The systematic description of oiled shorelines using the SCAT methodology proved very successful, even for such an old spill. 6 refs

  8. Ghost Remains After Black Hole Eruption

    Science.gov (United States)

    2009-05-01

    NASA's Chandra X-ray Observatory has found a cosmic "ghost" lurking around a distant supermassive black hole. This is the first detection of such a high-energy apparition, and scientists think it is evidence of a huge eruption produced by the black hole. This discovery presents astronomers with a valuable opportunity to observe phenomena that occurred when the Universe was very young. The X-ray ghost, so-called because a diffuse X-ray source has remained after other radiation from the outburst has died away, is in the Chandra Deep Field-North, one of the deepest X-ray images ever taken. The source, a.k.a. HDF 130, is over 10 billion light years away and existed at a time 3 billion years after the Big Bang, when galaxies and black holes were forming at a high rate. "We'd seen this fuzzy object a few years ago, but didn't realize until now that we were seeing a ghost", said Andy Fabian of the Cambridge University in the United Kingdom. "It's not out there to haunt us, rather it's telling us something - in this case what was happening in this galaxy billions of year ago." Fabian and colleagues think the X-ray glow from HDF 130 is evidence for a powerful outburst from its central black hole in the form of jets of energetic particles traveling at almost the speed of light. When the eruption was ongoing, it produced prodigious amounts of radio and X-radiation, but after several million years, the radio signal faded from view as the electrons radiated away their energy. HDF 130 Chandra X-ray Image of HDF 130 However, less energetic electrons can still produce X-rays by interacting with the pervasive sea of photons remaining from the Big Bang - the cosmic background radiation. Collisions between these electrons and the background photons can impart enough energy to the photons to boost them into the X-ray energy band. This process produces an extended X-ray source that lasts for another 30 million years or so. "This ghost tells us about the black hole's eruption long after

  9. A permeation theory for single-file ion channels: one- and two-step models.

    Science.gov (United States)

    Nelson, Peter Hugo

    2011-04-28

    How many steps are required to model permeation through ion channels? This question is investigated by comparing one- and two-step models of permeation with experiment and MD simulation for the first time. In recent MD simulations, the observed permeation mechanism was identified as resembling a Hodgkin and Keynes knock-on mechanism with one voltage-dependent rate-determining step [Jensen et al., PNAS 107, 5833 (2010)]. These previously published simulation data are fitted to a one-step knock-on model that successfully explains the highly non-Ohmic current-voltage curve observed in the simulation. However, these predictions (and the simulations upon which they are based) are not representative of real channel behavior, which is typically Ohmic at low voltages. A two-step association/dissociation (A/D) model is then compared with experiment for the first time. This two-parameter model is shown to be remarkably consistent with previously published permeation experiments through the MaxiK potassium channel over a wide range of concentrations and positive voltages. The A/D model also provides a first-order explanation of permeation through the Shaker potassium channel, but it does not explain the asymmetry observed experimentally. To address this, a new asymmetric variant of the A/D model is developed using the present theoretical framework. It includes a third parameter that represents the value of the "permeation coordinate" (fractional electric potential energy) corresponding to the triply occupied state n of the channel. This asymmetric A/D model is fitted to published permeation data through the Shaker potassium channel at physiological concentrations, and it successfully predicts qualitative changes in the negative current-voltage data (including a transition to super-Ohmic behavior) based solely on a fit to positive-voltage data (that appear linear). The A/D model appears to be qualitatively consistent with a large group of published MD simulations, but no

  10. Expansion of thermodynamic model of solute permeation through reverse osmosis membrane

    International Nuclear Information System (INIS)

    Nishimaki, Kenzo; Koyama, Akio

    1994-01-01

    Many studies have been performed on permeation mechanism of solute and solvent in membrane separation process like reverse osmosis or ultrafiltration, and several models of solute/solvent permeation through membrane are proposed. Among these models, Kedem and Katchalsky, based on the theory of thermodynamics of irreversible processes, formulated the one-solute permeation process in their mathematical model, which treats membrane as a black box, not giving consideration to membrane structure and to interaction between membrane material and permeates, viz. solute and solvent. According to this theory, the driving force of solute/solvent permeation through membrane is the difference of their chemical potential between both sides of membrane, and the linear phenomenological equation is applied to describing the relation between driving force and flux of solute/solvent. This equation can be applied to the irreversible process only when the process is almost in equilibrium. This condition is supposed to be satisfied in the solute/solvent permeation process through compact membrane with fine pores like reverse osmosis membrane. When reverse osmosis is applied to treatment process for liquid waste, which usually contains a lot of solutes as contaminants, we can not predict the behavior of contaminants by the above one-solute process model. In the case of multi-solutes permeation process for liquid waste, the number of parameter in thermodynamic model increases rapidly with the number of solute, because of coupling phenomenon among solutes. In this study, we expanded the above thermodynamic model to multi-solute process applying operational calculus to the differential equations which describe the irreversible process of the system, and expressed concisely solute concentration vector as a matrix product. In this way, we predict the behavior of solutes in multi-solutes process, using values of parameters obtained in two-solutes process. (author)

  11. An optimized probucol microencapsulated formulation integrating a secondary bile acid (deoxycholic acid as a permeation enhancer

    Directory of Open Access Journals (Sweden)

    Mooranian A

    2014-09-01

    Full Text Available Armin Mooranian,1 Rebecca Negrulj,1 Nigel Chen-Tan,2 Gerald F Watts,3 Frank Arfuso,4 Hani Al-Salami11Biotechnology and Drug Development Research Laboratory, School of Pharmacy, Curtin Health Innovation Research Institute, Biosciences Research Precinct, Curtin University, 2Faculty of Science and Engineering, Curtin University, 3School of Medicine and Pharmacology, Royal Perth Hospital, University of Western Australia, 4School of Biomedical Science, Curtin Health Innovation Research Institute, Biosciences Research Precinct, Curtin University, Perth, AustraliaAbstract: The authors have previously designed, developed, and characterized a novel microencapsulated formulation as a platform for the targeted delivery of therapeutics in an animal model of type 2 diabetes, using the drug probucol (PB. The aim of this study was to optimize PB microcapsules by incorporating the bile acid deoxycholic acid (DCA, which has good permeation-enhancing properties, and to examine its effect on microcapsules’ morphology, rheology, structural and surface characteristics, and excipients’ chemical and thermal compatibilities. Microencapsulation was carried out using a BÜCHI-based microencapsulating system established in the authors’ laboratory. Using the polymer sodium alginate (SA, two microencapsulated formulations were prepared: PB-SA (control and PB-DCA-SA (test at a constant ratio (1:30 and 1:3:30, respectively. Complete characterization of the microcapsules was carried out. The incorporation of DCA resulted in better structural and surface characteristics, uniform morphology, and stable chemical and thermal profiles, while size and rheological parameters remained similar to control. In addition, PB-DCA-SA microcapsules showed good excipients’ compatibilities, which were supported by data from differential scanning calorimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray studies, suggesting

  12. Effect of argon ion sputtering of surface on hydrogen permeation through vanadium

    International Nuclear Information System (INIS)

    Yamawaki, Michio; Namba, Takashi; Yoneoka, Toshiaki; Kanno, Masayoshi; Shida, Koji.

    1983-01-01

    In order to measure the hydrogen permeation rate through V with atomically cleaned surface, an Ar ion sputtering apparatus has been installed in the hydrogen permeability measuring system. The permeation rate of the initial specimen was found to be increased by about one order of magnitude after Ar ion sputtering of its upstream side surface. Repeating of such a sputter-cleaning was not so much effective in increasing the steady state permeation rate as the initial sputtering was, but it accelerated the transient response rate by a factor of 2 or 3. The transient response rate was also accelerated by the increase of hydrogen pressure, but this effect tended to be diminished by the sputter-cleaning of specimen surface. The surface impurity layer on the downstream side of specimen was also inferred to act as a diffusion barrier affecting the steady state permeation rate. The present value of activation energy for hydrogen permeation through V at temperatures below 873K was the smallest one ever obtained, showing that the surface effect was minimized in the present study on account of the surface sputter-cleaning in addition to the ultra high vacuum system. (author)

  13. Liquid crystalline systems for transdermal delivery of celecoxib: in vitro drug release and skin permeation studies.

    Science.gov (United States)

    Estracanholli, Eder André; Praça, Fabíola Silva Garcia; Cintra, Ana Beatriz; Pierre, Maria Bernadete Riemma; Lara, Marilisa Guimarães

    2014-12-01

    Liquid crystalline systems of monoolein/water could be a promising approach for the delivery of celecoxib (CXB) to the skin because these systems can sustain drug release, improve drug penetration into the skin layers and minimize side effects. This study evaluated the potential of these systems for the delivery of CXB into the skin based on in vitro drug release and skin permeation studies. The amount of CXB that permeated into and/or was retained in the skin was assayed using an HPLC method. Polarizing light microscopy studies showed that liquid crystalline systems of monoolein/water were formed in the presence of CXB, without any changes in the mesophases. The liquid crystalline systems decreased drug release when compared to control solution. Drug release was independent of the initial water content of the systems and CXB was released from cubic phase systems, irrespective of the initial water content. The systems released the CXB following zero-order release kinetics. In vitro drug permeation studies showed that cubic phase systems allowed drug permeation and retention in the skin layers. Cubic phase systems of monoolein/water may be promising vehicles for the delivery of CXB in/through the skin because it improved CXB skin permeation compared with the control solution.

  14. Development of permeate flux model for municipal wastewater treatment using membrane bioreactor

    International Nuclear Information System (INIS)

    Geissler, S.; Zhou, H.; Zytner, R.; Melin, T.

    2002-01-01

    In municipal wastewater treatment, membrane filtration technologies receive great attention because they usually produce the better quality effluent, generate less sludge and require a smaller aeration tank volume. However, one main challenge of using membranes is membrane fouling, which results in a permeate flux decrease or transmembrane pressure increase over the time. Many efforts have been directed to develop the mechanistic permeate flux model to correlate the permeate flux with process parameters. However, their applicability has been largely thwarted due to complicated membrane fouling mechanisms and the interactions of many factors affecting the membrane bioreactor. This paper proposes a semi-empirical permeate flux model for the membrane bioreactor (MBR) process using ZENON immersed hollow fibre membrane modules. The semi-empirical model was proposed by assuming that the permeate flux is equal to transmembrane pressure divided by total resistance. The total resistance is divided into two components: an inside membrane resistance and an outer fouling layer resistance. These membrane resistances are then related to the ageing of membrane used. Good correlation was found between the predicted and measured flux, with the mean absolute deviation being less than 4%. The observations also identified some general rules for operating membrane systems. Ideally, it is advisable that high pressure periods be avoided as this leads to a faster increase of non-reversal membrane resistance. It was also observed that membrane preservatives should be washed out carefully prior to use. (author)

  15. Dynamic permeation sources for volatile organic compounds (VOCS): 'a standards test environment' nuclear track detector

    International Nuclear Information System (INIS)

    Hussain, A.; Marr, I.

    2000-01-01

    The generation of a test environment for trace VOCs in urban air or work place has never been easy. This investigation is concerned with the loss rates of VOCs through polythene membrane of different thickness. Permeation glass sample bottles were suspended in the chamber with water jacket at 24 deg. C -+ 0.5 deg. temperature. The condenser was connected with a stream of nitrogen gas at a flow rate of 75-ml min/sup -1 and further diluted with air 500-ml min/sup -1/. The loss in weight of VOCs in each bottle was determined regularly, every 24 hours, with a good agreement. The loss rate depends upon temperature of the bath, thickness of the polythene, internal diameter of the permeation bottle opening. However the loss rate from permeation tubes also depends upon the solubility of the VOCs in the polymer. It is generally believed that the vapors of VOCs in the permeation bottle are dissolved in the polythene sheet (making some sort of solution) and are eventually evaporated out of it. It was observed that the loss rate per minute for benzene > toluene. This simple technique described 'generation of test environment through dynamic permeation source' could be suitable for preparing mixture of benzene, toluene and xylene in atmosphere at ppm levels or lower, with good stability, reliability and also for other compounds of atmospheric interest. (author)

  16. Alfuzosin hydrochloride transdermal films: evaluation of physicochemical, in vitro human cadaver skin permeation and thermodynamic parameters

    Directory of Open Access Journals (Sweden)

    Satyanarayan Pattnaik

    2009-12-01

    Full Text Available Purpose: The main objective of the investigation was to develop a transdermal therapeutic system for alfuzosin hydrochloride and to study the effects of polymeric system and loading dose on the in vitro skin permeation pattern. Materials and methods: Principles of experimental design have been exploited to develop the dosage form. Ratio of ethyl cellulose (EC and polyvinyl pyrrolidone (PVP and loading dose were selected as independent variables and their influence on the cumulative amount of alfuzosin hydrochloride permeated per cm2 of human cadaver skin at 24 h (Q24, permeation flux (J and steady state permeability coefficient (P SS were studied using experimental design. Various physicochemical parameters of the transdermal films were also evaluated. Activation energy for in vitro transdermal permeation has been estimated. Results: Ratio of EC and PVP was found to be the main influential factor for all the dependent variables studied. Drug loading dose was also found to influence the dependent variables but to a lesser extent. Physicochemical parameters of the prepared films were evaluated and found satisfactory. Activation energy for alfuzosin permeation has also been estimated and reported. Conclusion: The therapeutic system was found to be dermatologically non-irritant and hence, a therapeutically effective amount of alfuzosin hydrochloride can be delivered via a transdermal route.

  17. Resistance of gloves and protective clothing materials to permeation of cytostatic solutions.

    Science.gov (United States)

    Krzemińska, Sylwia; Pośniak, Małgorzata; Szewczyńska, Małgorzata

    2018-01-15

    The objective of the work was to determine the resistance of selected protective clothing and glove materials to permeation of cytostatics such as docetaxel, fluorouracil, and doxorubicin. The following glove materials were used: natural rubber latex (code A), acrylonitrile-butadiene rubber (code B) and chloroprene rubber (code C). In addition, we tested a layered material composed of a non-woven polyester (PES), a polypropylene (PP) film, and a non-woven PP used for protective coats (code D). The cytostatics were analyzed by liquid chromatography with diode array detection. The tested samples were placed in a purpose-built permeation cell modified to be different from that specified in the standard EN 6529:2001. The tested materials were characterized by good resistance to solutions containing 2 out of the 3 selected cytostatics: doxorubicin and 5-fluorouracil, as indicated by a breakthrough time of over 480 min. Equally high resistance to permeation of the third cytostatic (docetaxel) was exhibited by natural rubber latex, acrylonitrile-butadiene rubber, and chloroprene rubber. However, docetaxel permeated much more readily through the clothing layered material, compromising its barrier properties. It was found that the presence of additional components in cytostatic preparations accelerated permeation through material samples, thus deteriorating their barrier properties. Int J Occup Med Environ Health 2018;31(3):341-350. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  18. Chromatic response of polydiacetylene vesicle induced by the permeation of methotrexate.

    Science.gov (United States)

    Shin, Min Jae; Kim, Ye Jin; Kim, Jong-Duk

    2015-07-07

    The noble vesicular system of polydiacetylene showed a red shift using two types of detecting systems. One of the systems involves the absorption of target materials from the outer side of the vesicle, and the other system involves the permeation through the vesicular layers from within the vesicle. The chromatic mixed vesicles of N-(2-aminoethyl)pentacosa-10,12-diynamide (AEPCDA) and dimethyldioctadecylammonium chloride (DODAC) were fabricated by sonication, followed by polymerization by UV irradiation. The stability of monomeric vesicles was observed to increase with the polymerization of the vesicles. Methotrexate was used as a target material. The polymerized mixed vesicles having a blue color were exposed to a concentration gradient of methotrexate, and a red shift was observed indicating the adsorption of methotrexate on the polydiacetylene bilayer. In order to check the chromatic change by the permeation of methotrexate, we separated the vesicle portion, which contained methotrexate inside the vesicle, and checked chromatic change during the permeation of methotrexate through the vesicle. The red shift apparently indicates the disturbance in the bilayer induced by the permeation of methotrexate. The maximum contrast of color appeared at the equal molar ratio of AEPCDA and DODAC, indicating that the formation of flexible and deformable vesicular layers is important for red shift. Therefore, it is hypothesized that the system can be applicable for the chromatic detection of the permeation of methotrexate through the polydiacetylene layer.

  19. Impact of Humidity on In Vitro Human Skin Permeation Experiments for Predicting In Vivo Permeability.

    Science.gov (United States)

    Ishida, Masahiro; Takeuchi, Hiroyuki; Endo, Hiromi; Yamaguchi, Jun-Ichi

    2015-12-01

    In vitro skin permeation studies have been commonly conducted to predict in vivo permeability for the development of transdermal therapeutic systems (TTSs). We clarified the impact of humidity on in vitro human skin permeation of two TTSs having different breathability and then elucidated the predictability of in vivo permeability based on in vitro experimental data. Nicotinell(®) TTS(®) 20 and Frandol(®) tape 40mg were used as model TTSs in this study. The in vitro human skin permeation experiments were conducted under humidity levels similar to those used in clinical trials (approximately 50%) as well as under higher humidity levels (approximately 95%). The skin permeability values of drugs at 95% humidity were higher than those at 50% humidity. The time profiles of the human plasma concentrations after TTS application fitted well with the clinical data when predicted based on the in vitro permeation parameters at 50% humidity. On the other hand, those profiles predicted based on the parameters at 95% humidity were overestimated. The impact of humidity was higher for the more breathable TTS; Frandol(®) tape 40mg. These results show that in vitro human skin permeation experiments should be investigated under realistic clinical humidity levels especially for breathable TTSs. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  20. Ultrathin graphene-based membrane with precise molecular sieving and ultrafast solvent permeation

    Science.gov (United States)

    Yang, Q.; Su, Y.; Chi, C.; Cherian, C. T.; Huang, K.; Kravets, V. G.; Wang, F. C.; Zhang, J. C.; Pratt, A.; Grigorenko, A. N.; Guinea, F.; Geim, A. K.; Nair, R. R.

    2017-12-01

    Graphene oxide (GO) membranes continue to attract intense interest due to their unique molecular sieving properties combined with fast permeation. However, their use is limited to aqueous solutions because GO membranes appear impermeable to organic solvents, a phenomenon not yet fully understood. Here, we report efficient and fast filtration of organic solutions through GO laminates containing smooth two-dimensional (2D) capillaries made from large (10-20 μm) flakes. Without modification of sieving characteristics, these membranes can be made exceptionally thin, down to ~10 nm, which translates into fast water and organic solvent permeation. We attribute organic solvent permeation and sieving properties to randomly distributed pinholes interconnected by short graphene channels with a width of 1 nm. With increasing membrane thickness, organic solvent permeation rates decay exponentially but water continues to permeate quickly, in agreement with previous reports. The potential of ultrathin GO laminates for organic solvent nanofiltration is demonstrated by showing >99.9% rejection of small molecular weight organic dyes dissolved in methanol. Our work significantly expands possibilities for the use of GO membranes in purification and filtration technologies.

  1. Impacts of chemical enhancers on skin permeation and deposition of terbinafine.

    Science.gov (United States)

    Erdal, Meryem Sedef; Peköz, Ayca Yıldız; Aksu, Buket; Araman, Ahmet

    2014-08-01

    The addition of chemical enhancers into formulations is the most commonly employed approach to overcome the skin barrier. The objective of this work was to evaluate the effect of vehicle and chemical enhancers on the skin permeation and accumulation of terbinafine, an allylamine antifungal drug. Terbinafine (1% w/w) was formulated as a Carbopol 934 P gel formulation in presence and absence of three chemical enhancers, nerolidol, dl-limonene and urea. Terbinafine distribution and deposition in stratum corneum (SC) and skin following 8-h ex vivo permeation study was determined using a sequential tape stripping procedure. The conformational order of SC lipids was investigated by ATR-FTIR spectroscopy. Nerolidol containing gel formulation produced significantly higher enhancement in terbinafine permeation through skin and its skin accumulation was increased. ATR-FTIR results showed enhancer induced lipid bilayer disruption in SC. Urea resulted in enhanced permeation of terbinafine across the skin and a balanced distribution to the SC was achieved. But, dl-limonene could not minimize the accumulation of terbinafine in the upper SC. Nerolidol dramatically improved the skin permeation and deposition of terbinafine in the skin that might help to optimize targeting of the drug to the epidermal sites as required for both of superficial and deep cutaneous fungal infections.

  2. Determination of solvents permeating through chemical protective clothing with a microsensor array.

    Science.gov (United States)

    Park, J; Zellers, E T

    2000-08-01

    The performance of a novel prototype instrument in determining solvents and solvent mixtures permeating through samples of chemical protective clothing (CPC) materials was evaluated. The instrument contains a mini-preconcentrator and an array of three polymer-coated surface-acoustic-wave (SAW) microsensors whose collective response patterns are used to discriminate among multiple permeants. Permeation tests were performed with a 2.54 cm diameter test cell in an open-loop configuration on samples of common glove materials challenged with four individual solvents, three binary mixtures, and two ternary mixtures. Breakthrough times, defined as the times required for the permeation rate to reach a value of 1 microg cm(-2) min(-1), determined by the instrument were within 3 min of those determined in parallel by manual sampling and gas chromatographic analysis. Permeating solvents were recognized (identified) from their response patterns in 59 out of 64 measurements (92%) and their vapor concentrations were quantified to an accuracy of +/- 31% (typically +/- 10%). These results demonstrate the potential for such instrumentation to provide semi-automated field or bench-top screening of CPC permeation resistance.

  3. Skin Delivery of EGCG and Silibinin: Potential of Peptide Dendrimers for Enhanced Skin Permeation and Deposition.

    Science.gov (United States)

    Shetty, Pallavi Krishna; Manikkath, Jyothsna; Tupally, Karnaker; Kokil, Ganesh; Hegde, Aswathi R; Raut, Sushil Y; Parekh, Harendra S; Mutalik, Srinivas

    2017-08-01

    The aim of the present study was to evaluate the ability of the peptide dendrimers to facilitate transdermal delivery of antioxidants, silibinin, and epigallocatechin-3-gallate (EGCG). Drug-peptide dendrimer complexes were prepared and evaluated for their ability to permeate across the skin. The data revealed the ready formation of complexes between drug and peptide dendrimer in a molar ratio of 1:1. In vitro permeation studies using excised rat skin and drug-peptide dendrimer complexes showed highest values for cumulative drug permeation at the end of 12 h (Q 12 ), with corresponding permeability coefficient (Kp) and enhancement ratio values also determined at this time point. With silibinin, 3.96-, 1.81-, and 1.06-fold increase in skin permeation was observed from silibinin-peptide dendrimer complex, simultaneous application of silibinin + peptide dendrimer, and pretreatment of skin with peptide dendrimer, respectively, in comparison with passive diffusion. With EGCG, 9.82-, 2.04-, and 1.72-fold increase in skin permeation was observed from EGCG-peptide dendrimer complex, simultaneous application of EGCG + peptide dendrimer, and pretreatment of skin with peptide dendrimer, respectively, in comparison with passive diffusion. The present study demonstrates the application of peptide dendrimers in effectively delivering antioxidants such as EGCG and silibinin into the skin, thus offering the potential to provide antioxidant effects when delivered via appropriately formulated topical preparations.

  4. Tritium permeation and recovery for the Flibe/He blanket design

    International Nuclear Information System (INIS)

    Moir, R.

    1984-10-01

    This study assumes tritium to be a gas dissolved in molten salt, with TF formation suppressed. Tritium permeates readily through the hot steel tubes of the reactor and steam generator and will leak into the steam system at the rate of about one gram per day in the absence of special permeation barriers, assuming that 1% of the helium coolant flow rate is processed for tritium recovery at 90% efficiency per pass. Tritiated water in the steam system is a personnel hazard at concentration levels well below one part per million and this level would soon be reached without costly isotopic processing. Alternatively, including a combination of permeation barriers on reactor and steam generator tubes and molten salt processing is estimated to reduce the leak rate into the steam system by over two orders of magnitude. For the option with the lowest estimated leak rate, 55 Ci/d, it may be possible to purge the steam system continuously to prevent tritiated water buildup. At best, isotopic separation of dilute tritiated water may not be necessary and for higher leak-rate options the isotopic processing rate can be reduced. The proposed permeation barrier for the reactor tubes is a 10 μm layer of tungsten which, in principle, will reduce tritium blanket permeation by a factor of about 300 below the bare-steel rate

  5. Comparative study of silver nanoparticle permeation using Side-Bi-Side and Franz diffusion cells

    Science.gov (United States)

    Trbojevich, Raul A.; Fernandez, Avelina; Watanabe, Fumiya; Mustafa, Thikra; Bryant, Matthew S.

    2016-03-01

    Better understanding the mechanisms of nanoparticle permeation through membranes and packaging polymers has important implications for the evaluation of drug transdermal uptake, in food safety and the environmental implications of nanotechnology. In this study, permeation of 21 nm diameter silver nanoparticles (AgNPs) was tested using Side-Bi-Side and Franz static diffusion cells through hydrophilic 0.1 and 0.05 µm pore diameter 125 µm thick synthetic cellulose membranes, and 16 and 120 µm thick low-density polyethylene (LDPE) films. Experiments performed with LDPE films discarded permeation of AgNPs or Ag ions over the investigated time-frame in both diffusion systems. But controlled release of AgNPs has been quantified using semipermeable hydrophilic membranes. The permeation followed a quasi-linear time-dependent model during the experimental time-frame, which represents surface reaction-limited permeation. Diffusive flux, diffusion coefficients, and membrane permeability were determined as a function of pore size and diffusion model. Concentration gradient and pore size were key to understand mass transfer phenomena in the diffusion systems.

  6. Comparative study of silver nanoparticle permeation using Side-Bi-Side and Franz diffusion cells

    International Nuclear Information System (INIS)

    Trbojevich, Raul A.; Fernandez, Avelina; Watanabe, Fumiya; Mustafa, Thikra; Bryant, Matthew S.

    2016-01-01

    Better understanding the mechanisms of nanoparticle permeation through membranes and packaging polymers has important implications for the evaluation of drug transdermal uptake, in food safety and the environmental implications of nanotechnology. In this study, permeation of 21 nm diameter silver nanoparticles (AgNPs) was tested using Side-Bi-Side and Franz static diffusion cells through hydrophilic 0.1 and 0.05 µm pore diameter 125 µm thick synthetic cellulose membranes, and 16 and 120 µm thick low-density polyethylene (LDPE) films. Experiments performed with LDPE films discarded permeation of AgNPs or Ag ions over the investigated time-frame in both diffusion systems. But controlled release of AgNPs has been quantified using semipermeable hydrophilic membranes. The permeation followed a quasi-linear time-dependent model during the experimental time-frame, which represents surface reaction-limited permeation. Diffusive flux, diffusion coefficients, and membrane permeability were determined as a function of pore size and diffusion model. Concentration gradient and pore size were key to understand mass transfer phenomena in the diffusion systems.Graphical Abstract

  7. Liposomal buccal mucoadhesive film for improved delivery and permeation of water-soluble vitamins.

    Science.gov (United States)

    Abd El Azim, Heba; Nafee, Noha; Ramadan, Alyaa; Khalafallah, Nawal

    2015-07-05

    This study aims at improving the buccal delivery of vitamin B6 (VB6) as a model highly water-soluble, low permeable vitamin. Two main strategies were combined; first VB6 was entrapped in liposomes, which were then formulated as mucoadhesive film. Both plain and VB6-loaded liposomes (LPs) containing Lipoid S100 and propylene glycol (∼ 200 nm) were then incorporated into mucoadhesive film composed of SCMC and HPMC. Results showed prolonged release of VB6 (72.65%, T50% diss 105 min) after 6h from LP-film compared to control film containing free VB6 (96.37%, T50% diss 30 min). Mucoadhesion was assessed both ex vivo on chicken pouch and in vivo in human. Mucoadhesive force of 0.2N and residence time of 4.4h were recorded. Ex vivo permeation of VB6, across chicken pouch mucosa indicated increased permeation from LP-systems compared to corresponding controls. Interestingly, incorporation of the vesicles in mucoadhesive film reduced the flux by 36.89% relative to LP-dispersion. Meanwhile, both films provided faster initial permeation than the liquid forms. Correlating the cumulative percent permeated ex vivo with the cumulative percent released in vitro indicated that LPs retarded VB6 release but improved permeation. These promising results represent a step forward in the field of buccal delivery of water-soluble vitamins. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Purification Simulation With Vapor Permeation and Distillation-Adsorption In Bioethanol Plant

    Directory of Open Access Journals (Sweden)

    Misri Gozan

    2017-04-01

    Full Text Available High purity of Bioethanol is required in biofuel mixing with gasoline (EXX. In bioethanol production line, the azeotropic property of ethanol-water becomes the barrier for purification process. This study examined two bioethanol separation processes by support of simulation tools, Superpro Designer 9.0 software. Ethanol purity and a low costeconomical process were the major considerations. Purification method of vapor permeation membrane technology was compared with distillation-adsorption method. Data from previous lab experiments and some literatures were used. The results showed that distillation-adsorption method is more economical compared to vapor permeation technology. Payback period of the simulation is 3.9 years and 4.3 years to distillation adsorption and vapor permeation respectively with each IRR value is 20.23% and 17.89%. Initial investment value of vapor permeation is 9.6% higher than distillation method. Significant difference observed in operating costs, since more units involved in vapor permeation require more labors to operate.

  9. Comparative study of silver nanoparticle permeation using Side-Bi-Side and Franz diffusion cells

    Energy Technology Data Exchange (ETDEWEB)

    Trbojevich, Raul A. [U.S. Food and Drug Administration, Division of Biochemical Toxicology, National Center for Toxicological Research (United States); Fernandez, Avelina, E-mail: velifdez@ific.uv.es [Consejo Superior de Investigaciones Científicas-Universitat de València, Parc Científic, Instituto de Física Corpuscular (Spain); Watanabe, Fumiya; Mustafa, Thikra [University Arkansas at Little Rock, Center for Integrative Nanotechnology Sciences (United States); Bryant, Matthew S. [U.S. Food and Drug Administration, Division of Biochemical Toxicology, National Center for Toxicological Research (United States)

    2016-03-15

    Better understanding the mechanisms of nanoparticle permeation through membranes and packaging polymers has important implications for the evaluation of drug transdermal uptake, in food safety and the environmental implications of nanotechnology. In this study, permeation of 21 nm diameter silver nanoparticles (AgNPs) was tested using Side-Bi-Side and Franz static diffusion cells through hydrophilic 0.1 and 0.05 µm pore diameter 125 µm thick synthetic cellulose membranes, and 16 and 120 µm thick low-density polyethylene (LDPE) films. Experiments performed with LDPE films discarded permeation of AgNPs or Ag ions over the investigated time-frame in both diffusion systems. But controlled release of AgNPs has been quantified using semipermeable hydrophilic membranes. The permeation followed a quasi-linear time-dependent model during the experimental time-frame, which represents surface reaction-limited permeation. Diffusive flux, diffusion coefficients, and membrane permeability were determined as a function of pore size and diffusion model. Concentration gradient and pore size were key to understand mass transfer phenomena in the diffusion systems.Graphical Abstract.

  10. Combined use of bile acids and aminoacids to improve permeation properties of acyclovir.

    Science.gov (United States)

    Cirri, M; Maestrelli, F; Mennini, N; Mura, P

    2015-07-25

    The aim of this work was to develop a topical formulation with improved permeation properties of acyclovir. Ursodeoxycholic (UDC) and dehydrocholic (DHC) acids were tested as potential enhancers, alone or in combination with different aminoacids. Equimolar binary and ternary systems of acyclovir with cholic acids and basic, hydrophilic or hydrophobic aminoacids were prepared by co-grinding in a high vibrational micromill. Differential scanning calorimetry (DSC) was used to characterize the solid state of these systems, while their permeation properties were evaluated in vitro through a lipophilic artificial membrane. UDC was more than 2 times more effective than DHC in improving drug AUC and permeation rate. As for the ternary systems drug-UDC-aminoacid, only the combined use of l-lysine with UDC acid produced an evident synergistic effect in enhancing drug permeation properties, enabling an almost 3 and 8 times AUC increase compared to the binary UDC system or the pure drug, respectively. The best systems were selected for the development of topical cream formulations, adequately characterized and tested for in vitro drug permeation properties and stability on storage. The better performance revealed by acyclovir-UDC-l-lysine was mainly attributed to the formation of a more permeable activated system induced by the multicomponent co-grinding process. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Permeation of antigen protein-conjugated nanoparticles and live bacteria through microneedle-treated mouse skin

    Directory of Open Access Journals (Sweden)

    Kumar A

    2011-06-01

    Full Text Available Amit Kumar, Xinran Li, Michael A Sandoval, B Leticia Rodriguez, Brian R Sloat, Zhengrong CuiUniversity of Texas at Austin, College of Pharmacy, Pharmaceutics Division, Austin, TX, USABackground: The present study was designed to evaluate the extent to which pretreatment with microneedles can enhance skin permeation of nanoparticles in vitro and in vivo. Permeation of live bacteria, which are physically nanoparticles or microparticles, through mouse skin pretreated with microneedles was also studied to evaluate the potential risk of microbial infection.Methods and results: It was found that pretreatment of mouse skin with microneedles allowed permeation of solid lipid nanoparticles, size 230 nm, with ovalbumin conjugated on their surface. Transcutaneous immunization in a mouse skin area pretreated with microneedles with ovalbumin nanoparticles induced a stronger antiovalbumin antibody response than using ovalbumin alone. The dose of ovalbumin antigen determined whether microneedle-mediated transcutaneous immunization with ovalbumin nanoparticles induced a stronger immune response than subcutaneous injection of the same ovalbumin nanoparticles. Microneedle treatment permitted skin permeation of live Escherichia coli, but the extent of the permeation was not greater than that enabled by hypodermic injection.Conclusion: Transcutaneous immunization on a microneedle-treated skin area with antigens carried by nanoparticles can potentially induce a strong immune response, and the risk of bacterial infection associated with microneedle treatment is no greater than that with a hypodermic injection.Keywords: antibody responses, safety of microneedles, transepidermal water loss

  12. Permeation of antigen protein-conjugated nanoparticles and live bacteria through microneedle-treated mouse skin

    Science.gov (United States)

    Kumar, Amit; Li, Xinran; Sandoval, Michael A; Rodriguez, B Leticia; Sloat, Brian R; Cui, Zhengrong

    2011-01-01

    Background: The present study was designed to evaluate the extent to which pretreatment with microneedles can enhance skin permeation of nanoparticles in vitro and in vivo. Permeation of live bacteria, which are physically nanoparticles or microparticles, through mouse skin pretreated with microneedles was also studied to evaluate the potential risk of microbial infection. Methods and results: It was found that pretreatment of mouse skin with microneedles allowed permeation of solid lipid nanoparticles, size 230 nm, with ovalbumin conjugated on their surface. Transcutaneous immunization in a mouse skin area pretreated with microneedles with ovalbumin nanoparticles induced a stronger antiovalbumin antibody response than using ovalbumin alone. The dose of ovalbumin antigen determined whether microneedle-mediated transcutaneous immunization with ovalbumin nanoparticles induced a stronger immune response than subcutaneous injection of the same ovalbumin nanoparticles. Microneedle treatment permitted skin permeation of live Escherichia coli, but the extent of the permeation was not greater than that enabled by hypodermic injection. Conclusion: Transcutaneous immunization on a microneedle-treated skin area with antigens carried by nanoparticles can potentially induce a strong immune response, and the risk of bacterial infection associated with microneedle treatment is no greater than that with a hypodermic injection. PMID:21753877

  13. Comparison of implantation-driven permeation characteristics of fusion reactor structural materials

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Anderl, R.A.; Struttmann, D.A.

    1986-01-01

    Implantation-driven permeation experiments have been conducted on samples of the ferritic steel HT-9, the austenitic Primary Candidate Alloy (PCA) and the vanadium alloy V-15Cr-5Ti using D 3 + ions under conditions that simulate charge-exchange neutral loading on a fusion reactor first wall. The steels all exhibited an initially intense permeation ''spike'' followed by an exponential decrease to low steady-state values. That spike was not evident in the V-15Cr-5Ti experiments. Steady-state permeation was highest in the vanadium alloy and lowest in the austenitic steel. Though permeation rates in the HT-9 were lower than those in V-15Cr-5Ti, permeation transients were much faster in HT-9 than in other materials tested. Ion-beam sputtering of the surface in the steel experiments resulted in enhanced remission at the front surface, whereas in the vanadium tests, recombination and diffusivity both appeared to diminish as the deuterium concentration rose. This may be due to a phase change in the material. We conclude that for conditions comparable to those of these experiments, tritium retention and loss in first wall structures made of steels will be less than in structures made of V-15Cr-5Ti

  14. Implications of recent implantation-driven permeation experiments for fusion reactor safety

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Anderl, R.A.; Struttmann, D.A.

    1986-01-01

    Metal structures exposed to the plasma in tritium-burning fusion reactors will be subject to implantation-driven permeation (IDP) of tritium. Permeation rates for IDP in fusion structural materials are usually high because the tritium atoms enter the material without having to go through the dissociation and solution steps required of tritium-bearing gas molecules. These surface processes, which may be rate limiting in PDP, actually enhance permeation in IDP by inhibiting the return of tritium to the plasma side of the structure. Experiments have been conducted at the Idaho National Engineering Laboratory (INEL) to investigate the nature of IDP by simulating conditions experienced by structures exposed to the plasma. These experiments have shown that surface conditions are important to tritium permeation in materials endothermic to hydrogen solution such as austenitic and ferritic steels. In reactive metals such as vanadium, surface processes appear to totally control the permeation. The purpose of this paper is to review the progress of those experiments and to discuss the implications that the results have regarding the tritium-related safety concerns of fusion reactors

  15. Influence of nitrogen ion implantation on hydrogen permeation in an extra mild steel

    International Nuclear Information System (INIS)

    Brass, A.M.; Chene, J.; Pivin, J.C.

    1989-01-01

    This paper presents the first results on the effect of nitrogen implantation on hydrogen permeation in steels. Nitrogen can modify superficially the steel's chemistry and/or microstructure depending on the fluence and thereby affect the processes of hydrogen diffusion and trapping. The implantations were performed on low carbon steel specimens with different nominal doses (1% to 10% and 33% nitrogen in a superficial layer of approximately 100 to 120 nm). The corresponding microstructures were characterized and permeation tests were conducted at room temperature in a double electrolytic cell. The nitrogen implanted layers on iron affects the electrochemical behaviour of the surface and the permeation in the material. This effect depends on the nitrogen concentration in the layer and on the corresponding microstructure. A continuous Fe 2 N layer acts as an efficient barrier to hydrogen entry and permeation when the layer is located on the entry face of the permeation membrane. This effect is stronger when the implanted layer is on the downstream face of the membrane. The low permeability values are mainly attributed to a lower hydrogen solubility in the implanted layer, whereas hydrogen trapping on defects and nitride precipitates delay hydrogen penetration. (author)

  16. RF plasma-driven hydrogen permeation through a biased iron membrane

    International Nuclear Information System (INIS)

    Banno, T.; Waelbroeck, F.; Winter, J.

    1984-01-01

    The steady-state RF plasma-driven hydrogen permeation through an electrically biased iron membrane has been investigated as a function of the bias potential Vsub(M) for membrane temperatures in the range of 150-400 0 C. Vsub(M) has been gradually increased positively from the floating potential of the membrane. The permeation flux decreases when Vsub(M) increases at low voltages: positive hydrogen ions are repelled. The membrane temperature does not influence this effect measurably. The permeation flux starts to increase when Vsub(M) is raised higher, i.e. when energetic electrons strike the surface. This phenomenon shows a pronounced temperature dependence - the enhancement is largest for the lowest temperatures. The effect is interpreted in terms of an electron-induced dissociation of hydrogen molecules on the membrane surface. (orig.)

  17. Characterization and utilization of the permeate and retentate obtained after “dead-end” ultrafiltration

    Directory of Open Access Journals (Sweden)

    Vasić Vesna M.

    2013-01-01

    Full Text Available In the recent years, with the increase in bioethanol production, the increasing amounts of distillery wastewater are generated. Such wastewater (stillage is one of the most polluted waste product of the food and beverage industries. The present study evaluates the treatment of distillery wastewater by ultrafiltration (UF, in order to reduce its pollution and evaluate the composition of the permeate and retentate. Polyethersulfone ultrafiltration membrane with molecular weight cut-off (MWCO 30000 Da, was used for the experiments. The UF was carried out in dead-end mode. The results of the analyses of the permeate and retentate obtained after ultrafiltration were considered as well as different ways for their further utilization. The pollutant level in the permeate was decreased significantly in comparison to the raw stillage, and suspended solids were completely removed from the stillage. [Projekat Ministarstva nauke Republike Srbije, br. TR 31002

  18. Testing of Disposable Protective Garments Against Isocyanate Permeation From Spray Polyurethane Foam Insulation.

    Science.gov (United States)

    Mellette, Michael P; Bello, Dhimiter; Xue, Yalong; Yost, Michael; Bello, Anila; Woskie, Susan

    2018-05-12

    Diisocyanates (isocyanates), including methylene diphenyl diisocyanate (MDI), are the primary reactive components of spray polyurethane foam (SPF) insulation. They are potent immune sensitizers and a leading cause of occupational asthma. Skin exposure to isocyanates may lead to both irritant and allergic contact dermatitis and possibly contribute to systemic sensitization. More than sufficient evidence exists to justify the use of protective garments to minimize skin contact with aerosolized and raw isocyanate containing materials during SPF applications. Studies evaluating the permeation of protective garments following exposure to SPF insulation do not currently exist. To conduct permeation testing under controlled conditions to assess the effectiveness of common protective gloves and coveralls during SPF applications using realistic SPF product formulations. Five common disposable garment materials [disposable latex gloves (0.07 mm thickness), nitrile gloves (0.07 mm), vinyl gloves (0.07 mm), polypropylene coveralls (0.13 mm) and Tyvek coveralls (0.13 mm)] were selected for testing. These materials were cut into small pieces and assembled into a permeation test cell system and coated with a two-part slow-rise spray polyurethane foam insulation. Glass fiber filters (GFF) pretreated with 1-(9-anthracenylmethyl)piperazine) (MAP) were used underneath the garment to collect permeating isocyanates. GFF filters were collected at predetermined test intervals between 0.75 and 20.00 min and subsequently analyzed using liquid chromatography-tandem mass spectrometry. For each garment material, we assessed (i) the cumulative concentration of total isocyanate, including phenyl isocyanate and three MDI isomers, that effectively permeated the material over the test time; (ii) estimated breakthrough detection time, average permeation rate, and standardized breakthrough time; from which (iii) recommendations were developed for the use of similar protective garments following

  19. Investigating the sonophoresis effect on the permeation of diclofenac sodium using 3D skin equivalent.

    Science.gov (United States)

    Aldwaikat, Mai; Alarjah, Mohammed

    2015-01-01

    Ultrasound temporally increases skin permeability by altering stratum corneum SC function (sonophoresis). The objective of this study was to evaluate the effect of variable ultrasound conditions on the permeation of diclofenac sodium DS with range of physicochemical properties through EpiDerm™. Permeation studies were carried out in vitro using Franz diffusion cell. HPLC method was used for the determination of the concentration of diclofenac sodium in receiving compartment. Parameters like ultrasound frequency, application time, amplitude, and mode of sonication and distance of ultrasound horn from skin were investigated, and the conditions where the maximum enhancement rate obtained were determined. Application of ultrasound enhanced permeation of diclofenac sodium across EpiDerm™ by fivefolds. The most effective enhancing parameters were power sonication of 20kHz frequency, 20% amplitude at continuous mode for 5min. Copyright © 2014. Published by Elsevier B.V.

  20. Effect of phonophoresis on skin permeation of commercial anti-inflammatory gels: sodium diclofenac and ketoprofen.

    Science.gov (United States)

    Souza, Jaqueline; Meira, Alianise; Volpato, Nadia Maria; Mayorga, Paulo; Gottfried, Carmem

    2013-09-01

    This study evaluated the use of ultrasound in combination with the commercial anti-inflammatory drugs ketoprofen and sodium diclofenac, according to the parameters used in physiotherapy. Ketoprofen and sodium diclofenac were used in the Franz diffusion cell model adapted to an ultrasound transducer in three conditions: no ultrasound, one application of ultrasound and two applications of ultrasound. High-performance liquid chromatography was used to quantify the total amount of drug permeating skin per unit area, as well as flux and latency. The results showed that for ketoprofen, the amount of drug permeating skin and flux increased with two ultrasound applications. Permeation of sodium diclofenac decreased in the presence of ultrasound. Ultrasound parameters and drug properties must be considered in the use of phonophoresis. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  1. Experimental measurements of the permeation of hydrogen isotopes in lithium filled niobium cells

    International Nuclear Information System (INIS)

    Goodall, D.H.J.; McCracken, G.M.; Austin, G.E.

    1976-01-01

    Lithium filled niobium cells have been heated in vacua at temperatures in the range 300 to 900 0 C. By measuring the flow of deuterium into the cell it has been possible to make estimates of the rate of permeation of deuterium in the niobium wall. After initial fast diffusion into the capsule the rate of permeation becomes very much slower than that determined by diffusion in the bulk niobium indicating that a second, slower, rate process is involved. Measurements of the rate of deuterium permeation out of the cell have been made for a number of different cell geometries and a range of temperatures. The results indicate that the slow rate process, which is dominant at low concentrations, is the desorption step from the metal to the gas phase

  2. Peculiarities of hydrogen permeation through Zr–1%Nb alloy and evaluation of terminal solid solubility

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, E.A.; Kompaniets, M.V.; Kompaniets, T.N., E-mail: tkompaniets@spbu.ru; Bobkova, I.S.

    2016-04-15

    Hydrogen permeation through Zr–1%Nb alloy was studied at the temperature below the temperature of α-β transition. Analysis of the transient permeation curves from a closed volume in a surface limited regime allowed to determine total and mobile hydrogen concentrations. At the mobile hydrogen concentration of 4.3 at% a part of the absorbed hydrogen is cut out of permeation process. Increase of the mobile hydrogen concentration in α-phase of Zr–1%Nb alloy is ceasing at the concentration of (5.5 ± 0.3) at%, which is the maximum possible concentration of the mobile hydrogen in α-phase of the studied alloy. From this moment on all absorbed hydrogen is spent on hydride formation. The obtained results are compared with those obtained by means of traditional techniques for terminal solid solubility determination.

  3. The influence of corneocyte structure on the interpretation of permeation profiles of nanoparticles across skin

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, T. [LFI, Instituto Tecnologico Nuclear, and Centro de Fisica Nuclear, Universidade Lisboa E.N. 10, 2685-953 Sacavem (Portugal)]. E-mail: murmur@itn.pt; Pallon, J. [Lund Institute of Technology, Physics Department, Lund University, Lund (Sweden)]. E-mail: Jan.Pallon@pixe.lth.se; Alves, L.C. [LFI, Instituto Tecnologico Nuclear, and Centro de Fisica Nuclear, Universidade Lisboa E.N. 10, 2685-953 Sacavem (Portugal)]. E-mail: lcalves@itn.pt; Verissimo, A. [LFI, Instituto Tecnologico Nuclear, and Centro de Fisica Nuclear, Universidade Lisboa E.N. 10, 2685-953 Sacavem (Portugal)]. E-mail: averissimo@vims.edu; Filipe, P. [Departamento Dermatologia, Hospital Sta. Maria, Lisbon (Portugal)]. E-mail: pfilipe@fm.ul.pt; Silva, J.N. [Departamento Dermatologia, Hospital Sta. Maria, Lisbon (Portugal)]. E-mail: maiasilva@fm.ul.pt; Silva, R. [Departamento Dermatologia, Hospital Sta. Maria, Lisbon (Portugal)]. E-mail: rpalminhas@netcabo.pt

    2007-07-15

    The permeability of skin to nanoparticles of titanium dioxide (TiO{sub 2}) used in sunscreens as a reflector of the UV wavelengths of sunlight, was examined using nuclear microscopy techniques. Special attention was given to the permeation characteristics of these nanoparticles across the outer layers of skin, the stratum corneum, in healthy and psoriatic skin condition. Aspects that may influence the interpretation of results such as sample preparation difficulties and skin condition were focused. Sample preparation can damage the integrity of the corneocyte layers inducing unwanted artefacts that may bias the evaluation of results. Irradiation conditions may also introduce distortions in the labile structures of human skin. Skin condition, such as loss of corneocyte cohesion occurring in psoriasis also influence the permeation profile of the nanoparticles. Weighing and accounting for these features in the examination of skin by nuclear microscopy is crucial to accurately assess the TiO{sub 2} nanoparticles permeation depth.

  4. In vitro permeation studies of nanoemulsions containing ketoprofen as a model drug.

    Science.gov (United States)

    Kim, Beom Su; Won, Myoung; Lee, Kang Min; Kim, Cheo Sang

    2008-09-01

    We prepared a nanoemulsion system with benzyl alcohol/ ethanol/Solutol/smash(R) HS 15 /water. Ketoprofen was used as a model drug in this study. The nanoemulsions of this system evidenced a high degree of stability. The droplet diameter did not change over a period of at least 3 months. The nanoemulsion containing 4% benzyl alcohol evidenced a permeation rate higher than was observed with the 1% and 2% nanoemulsions. Also the nanoemulsion containing 1% Solutol(R) HS 15 provided a permeation rate higher than was seen with the 2% and 4% nanoemulsions. All ketoprofen-loaded nanoemulsions enhanced the in vitro permeation rate through mouse skins as compared to the control.

  5. Effects of thin films on inventory, permeation and re-emission of energetic hydrogen

    International Nuclear Information System (INIS)

    Ohyabu, N.; Nakamura, Y.; Nakahara, Y.; Livshits, A.; Alimov, V.; Busnyuk, A.; Notkin, M.; Samartsev, A.; Doroshin, A.

    2000-01-01

    A non-metallic coating thicker than the implantation depth may protect a metal against tritium retention and permeation. However, a thinner film has quite the opposite effect: a dramatic increase of permeation and retention, and a corresponding suppression of re-emission. In view of the benefits expected from particle control with a superpermeable membrane placed right inside the divertor, the behavior of a Nb sample was investigated in a plasma-membrane device having a graphite target. Even polyatomic carbide coating was found not to hinder hydrogen absorption and permeation. Polyatomic non-carbide C films effectively inhibits it, but the formation of such films depends on H and C fluxes, H energy and metal temperature. A durable isolation of suprathermal hydrogen with the superpermeable membrane was observed at a high enough ratio between H and C fluxes, and the effects of carbon were found to have a non-monotonic temperature dependence

  6. Deuterium gas-driven permeation and subsequent retention in rolled tungsten foils

    International Nuclear Information System (INIS)

    Liu, Feng; Zhou, Haishan; Li, Xiao-Chun; Xu, Yuping; An, Zhongqing; Mao, Hongmin; Xing, Wenjing; Hou, Qing; Luo, Guang-Nan

    2014-01-01

    Experiments concerning deuterium gas-driven permeation through rolled tungsten foils in the temperature range of 850–950 K and subsequent deuterium retention have been performed. The steady state permeation flux of deuterium is proportional to the square root of the driving pressure. The permeability of deuterium is in an order of 10 −14 mol m −1 s −1 Pa −1/2 in this temperature range and the activation energy for permeation is 1.21 eV. Measurements of diffusivity are significantly affected by the driving pressure, which can be well explained by a saturable-trap model. Thermal desorption spectra of samples feature a single deuterium release peak at about 873 K. TMAP 4 modeling of this peak gives a detrapping energy of 1.70 eV, which fits the dissociation enthalpy of deuterium desorbing from the inner wall of vacancy clusters or pores in tungsten

  7. Deuterium gas-driven permeation and subsequent retention in rolled tungsten foils

    Science.gov (United States)

    Liu, Feng; Zhou, Haishan; Li, Xiao-Chun; Xu, Yuping; An, Zhongqing; Mao, Hongmin; Xing, Wenjing; Hou, Qing; Luo, Guang-Nan

    2014-12-01

    Experiments concerning deuterium gas-driven permeation through rolled tungsten foils in the temperature range of 850-950 K and subsequent deuterium retention have been performed. The steady state permeation flux of deuterium is proportional to the square root of the driving pressure. The permeability of deuterium is in an order of 10-14 mol m-1 s-1 Pa-1/2 in this temperature range and the activation energy for permeation is 1.21 eV. Measurements of diffusivity are significantly affected by the driving pressure, which can be well explained by a saturable-trap model. Thermal desorption spectra of samples feature a single deuterium release peak at about 873 K. TMAP 4 modeling of this peak gives a detrapping energy of 1.70 eV, which fits the dissociation enthalpy of deuterium desorbing from the inner wall of vacancy clusters or pores in tungsten.

  8. Production of citric acid from whey permeate by fermentation using Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, M; Brooks, J D

    1983-08-01

    The use of lactic casein whey permeate as a substrate for citric acid production by fermentation has been investigated. Using a mutant strain of Aspergillus niger IMI 41874 in fermenter culture, a citric acid concentration of 8.3 g/l, representing a yield of 19% (w/w) based on lactose utilized, has been observed. Supplementation of the permeate with lactose (final concentration 140 g/l) increased the production to 14.8 g/l (yield 23%). The natural pH of the permeate (pH 4.5) was the most suitable initial pH for the process, and pH control during the fermentation was unnecessary. The addition of methanol (final concentration 3% v/v) to the fermentation increased the citric acid production to 25 g/l (yield 33%, based on lactose utilized). 13 references.

  9. Preparation and Skin Permeation Study of N, N- Diethyl- meta-Toluamide Semi Solid Formulations

    Directory of Open Access Journals (Sweden)

    Solmaz Ghaffari

    2013-06-01

    Full Text Available N,N-Diethyl meta Toluamide (DEET is an insect repellent agent that contrary to its benefits, if is used in formulations with high skin permeation, will produce side effects of different severity. This study attempted to achieve a semi-solid DEET containing formulation with good appearance, sufficient spreadity, suitable viscosity for tube and jar filling, compatible pH with skin, reasonable stability, longer release time, and the less skin permeation. To obtain such a formulation, three types of DEET containing semi solids including gels (hydrophile, creams (emulsion and ointments (lipophile, and their characteristics were compared with each other and with Off! Brand. Results showed that one of the prepared creams with the proper viscosity, stability, appearance and spreadity, had the least drug release in six hours and less skin permeation of DEET as compared with Off!. Hence the preparation was introduced as the optimal formulation.

  10. Investigation of non-magnetic alloys for the suppression of tritium permeation. Final report

    International Nuclear Information System (INIS)

    1980-07-01

    This report describes a small (300 man hour) literature survey relating to the suppression of tritium loss by permeation through the walls of fusion reactors. The program was based on prior in-house Thermacore work to suppress hydrogen permeation into high temperature (800 0 C) heat pipes. The Thermacore approach involves selection of a steel with a small (.5 to 5%) aluminum content. The aluminum is diffused to the surface and oxidized. The present work was aimed at identification of alloys which might combine low tritium permeation with other properties desired in fusion reactor vessels, heat exchangers, lithium-handling plumbing and other components likely to contain tritium. These properties include low radiation damage, low magnetic permeability, high temperature strength, and compatibility with potential heat transfer and blanket materials. The work consisted of two tasks: Problem Definition and Literature Search and Analysis

  11. Re-evaluation of SiC permeation coefficients at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Yasushi, E-mail: yama3707@kansai-u.ac.jp [Faculty of Engineering Science, Kansai Univ., Yamate-cho, Suita, Osaka 564-8680 (Japan); Murakami, Yuichiro; Yamaguchi, Hirosato; Yamamoto, Takehiro; Yonetsu, Daigo [Faculty of Engineering Science, Kansai Univ., Yamate-cho, Suita, Osaka 564-8680 (Japan); Noborio, Kazuyuki [Hydrogen Isotope Research Center, Univ. of Toyama, Toyama, Toyama 930-8555 (Japan); Konishi, Satoshi [Institute of Advanced Energy, Kyoto Univ., Gokasho, Uji, Kyoto 611-0011 (Japan)

    2016-11-01

    Highlights: • The deuterium permeation coefficients of CVD-SiC at 600–950 °C were evaluated. • The wraparound flow was reduced to less than 1/100th of the permeation flow. • CVD-SiC materials are very effective as hydrogen isotope permeation barriers. - Abstract: Since 2007, our group has studied the deuterium permeation and diffusion coefficients for SiC materials at temperatures above 600 °C as a means of evaluating the tritium inventory and permeation in fusion blankets. During such measurements, control and evaluation of the wraparound flow through the sample holder are important, and so the heated sample holder is enclosed by a glass tube and kept under vacuum during experimental trials. However, detailed studies regarding the required degree of vacuum based on model calculations have shown that the wraparound flow is much larger than expected, and so can affect measurements at high temperatures. We therefore modified the measurement apparatus based on calculations involving reduced pressure in the glass tube, and are now confident that the measurement error is only several percent, even at 950 °C. In this paper, recent experimental results obtained with a chemical vapor deposition (CVD)-SiC sample over the temperature range of 600–950 °C are presented, showing that the permeation coefficient for CVD-SiC is more than three orders of magnitude smaller than that for stainless steel (SS316) at 600 °C, and that at 950 °C, the coefficient for CVD-SiC is almost equal to that for SUS316 at 550 °C.

  12. Systematic review finds that study data not published in full text articles have unclear impact on meta-analyses results in medical research.

    Science.gov (United States)

    Schmucker, Christine M; Blümle, Anette; Schell, Lisa K; Schwarzer, Guido; Oeller, Patrick; Cabrera, Laura; von Elm, Erik; Briel, Matthias; Meerpohl, Joerg J

    2017-01-01

    A meta-analysis as part of a systematic review aims to provide a thorough, comprehensive and unbiased statistical summary of data from the literature. However, relevant study results could be missing from a meta-analysis because of selective publication and inadequate dissemination. If missing outcome data differ systematically from published ones, a meta-analysis will be biased with an inaccurate assessment of the intervention effect. As part of the EU-funded OPEN project (www.open-project.eu) we conducted a systematic review that assessed whether the inclusion of data that were not published at all and/or published only in the grey literature influences pooled effect estimates in meta-analyses and leads to different interpretation. Systematic review of published literature (methodological research projects). Four bibliographic databases were searched up to February 2016 without restriction of publication year or language. Methodological research projects were considered eligible for inclusion if they reviewed a cohort of meta-analyses which (i) compared pooled effect estimates of meta-analyses of health care interventions according to publication status of data or (ii) examined whether the inclusion of unpublished or grey literature data impacts the result of a meta-analysis. Seven methodological research projects including 187 meta-analyses comparing pooled treatment effect estimates according to different publication status were identified. Two research projects showed that published data showed larger pooled treatment effects in favour of the intervention than unpublished or grey literature data (Ratio of ORs 1.15, 95% CI 1.04-1.28 and 1.34, 95% CI 1.09-1.66). In the remaining research projects pooled effect estimates and/or overall findings were not significantly changed by the inclusion of unpublished and/or grey literature data. The precision of the pooled estimate was increased with narrower 95% confidence interval. Although we may anticipate that

  13. Analysis on tritium permeation in tritium storage bed with gas flowing calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hirofumi; Hayashi, Takumi; Suzuki, Takumi; Nishi, Masataka [Japan Atomic Energy Research Inst., Naka Fusion Research Establishment, Department of Fusion Engineering Research, Naka, Ibaraki (Japan); Yoshida, Hiroshi [Japan Atomic Energy Research Inst., Naka Fusion Research Establishment, ITER-Joint Centeral Team, Naka, Ibaraki (Japan)

    2000-10-01

    Tritium permeation amount in a tritium storage bed with gas flowing calorimetric was evaluated under a condition of new operation mode for International Thermonuclear Experimental Reactor (ITER). As a result, tritium permeation under the new operation mode was estimated to be about twice of that under the practical operation mode. This result show that it would be regardless in a view point of material control of tritium, however, it was suggested to be required additional tritium removal or evacuate system in a view points of safety control or performance of accountability or thermal insulating of the tritium storage bed. (author)

  14. Silicon Carbide as a tritium permeation barrier in tungsten plasma-facing components

    Science.gov (United States)

    Wright, G. M.; Durrett, M. G.; Hoover, K. W.; Kesler, L. A.; Whyte, D. G.

    2015-03-01

    The control of tritium inventory is of great importance in future fusion reactors, not only from a safety standpoint but also to maximize a reactor's efficiency. Due to the high mobility of hydrogenic species in tungsten (W) one concern is the loss of tritium from the system via permeation through the tungsten plasma-facing components (PFC). This can lead to loss of tritium through the cooling channels of the wall thereby mandating tritium monitoring and recovery methods for the cooling system of the first wall. The permeated tritium is then out of the fuel cycle and cannot contribute to energy production until it is recovered and recycled into the system.

  15. Deuterium permeation behavior of HTUPS4 steel with thermal oxidation layer

    International Nuclear Information System (INIS)

    Xu, Yu-Ping; Liu, Feng; Zhao, Si-Xiang; Li, Xiao-Chun; Wang, Jing; An, Zhong-Qing; Lu, Tao; Liu, Hao-Dong; Ding, Fang; Zhou, Hai-Shan; Luo, Guang-Nan

    2016-01-01

    The permeation behavior of creep-resistant, Al 2 O 3 -forming HTUPS austenitic stainless steels was studied using a gas driven permeation (GDP) device. The steel samples were first thermal oxidized at air condition, followed by GDP experiments. The permeability and diffusion coefficients of oxidized samples and bare 316L steels were derived and compared. In order to characterize the oxide layer, X-ray photoelectron spectroscopy was performed. An oxide layer with a thickness of 200 nm which mainly consists of Al 2 O 3 was detected.

  16. Concentration gradient driven molecular dynamics: a new method for simulations of membrane permeation and separation.

    Science.gov (United States)

    Ozcan, Aydin; Perego, Claudio; Salvalaglio, Matteo; Parrinello, Michele; Yazaydin, Ozgur

    2017-05-01

    In this study, we introduce a new non-equilibrium molecular dynamics simulation method to perform simulations of concentration driven membrane permeation processes. The methodology is based on the application of a non-conservative bias force controlling the concentration of species at the inlet and outlet of a membrane. We demonstrate our method for pure methane, ethane and ethylene permeation and for ethane/ethylene separation through a flexible ZIF-8 membrane. Results show that a stationary concentration gradient is maintained across the membrane, realistically simulating an out-of-equilibrium diffusive process, and the computed permeabilities and selectivity are in good agreement with experimental results.

  17. Nitride and carbide thin films as hydrogen permeation barrier on Manet steel

    International Nuclear Information System (INIS)

    Benamati, G.; Checchetto, R.; Bonelli, M.; Gratton, L.M.; Guzman, L.; Miotello, A.; Terlain, A.

    1995-01-01

    TiC / TiN bilayers, ∼ 1.2 μm thick, were deposited on Manet II steel by the ion beam assisted deposition technique to investigate the possible use of this ceramic coating as hydrogen barrier. Hydrogen permeation experiments in the temperature range 470-570 K showed indeed that this coating is a very efficient barrier to the hydrogen permeation being able to reduce the hydrogen flux up to two order of magnitude with respect to the uncoated steel. Preliminary compatibility tests between coated Manet II and Pb-17Li showed no attack of Pb-17Li to the steel. (orig.)

  18. Nitride and carbide thin films as hydrogen permeation barrier on MANET steel

    International Nuclear Information System (INIS)

    Benamati, G.

    1994-01-01

    TiC/TiN bilayers, - 1.2 μm thick, were deposited on Manet II steel by the ion beam assisted deposition technique to investigate the possible use of this ceramic coating as hydrogen barrier. Hydrogen permeation experiments in the temperature range 470-570 K showed indeed that this coating is a very efficient barrier to the hydrogen permeation being able to reduce the hydrogen flux up to two order of magnitude with respect to the uncoated steel. Preliminary compatibility tests between coated Manet II and Pb-17Li showed no attack of Pb-17Li to the steel. (author) 8 refs.; 2 figs.; 1 tab

  19. Implantation measurements to determine tritium permeation in first-wall structures

    International Nuclear Information System (INIS)

    Holland, D.F.; Causey, R.A.; Sattler, M.L.

    1983-01-01

    A principal safety concern for a D-T burning fusion reactor is release of tritium during routine operation. Tritium implantation into first-wall structures, and subsequent permeation into coolants, is potentially an important source of tritium loss. This paper reports on an experiment in which an ion accelerator was used to implant deuterium atoms in a stainless steel disk to simulate tritium implantation in first-wall structures. The permeation rate was measured under various operating conditions. These results were used in the TMAP computer code to determine potential tritium loss rates for fusion reactors

  20. Hydrogen and deuterium permeation in copper alloys, copper--gold brazing alloys, gold, and the in situ growth of stable oxide permeation barriers

    International Nuclear Information System (INIS)

    Begeal, D.R.

    1978-01-01

    The deuterium permeation through several copper alloys has been measured over a temperature range of 550 to 830 K using the membrane technique. In some cases, the hydrogen permeability was also measured. The results were divided into three categories: common alloys, gold alloys, and stable oxide forming alloys. Common alloys which showed typical bulk metallic diffusion with litle change in the permeation activation energy as compared to copper (77 kJ/mol for D 2 ) were: (additions are in weight percent) 5% Sn, 2.3% U, 0.15% Zr, 4% Sn+4% Pb+4% Zn, 3% Si, and 7% Al+2% Fe. Compared to copper, the D 2 permeability at 573 K was reduced by factors of 2.0, 2.7, 4.5, 5.3, 5.9, and 7.0, respectively. A series of gold--copper alloys including pure gold, 80% Au, 50% Au, 49% Au, and 35% Au also showed typical bulk metallic diffusion with a trend of decreasing permeability (increasing activation energies for permeation) with increasing gold content. There were also pronounced inflections or shifts in the permeability at approx.370 0 C, or about the order--disorder transition for Cu 3 Au and CuAu, for the 80% and 50% alloys. Two alloys did not exhibit bulk metallic permeation behavior and the permeabiltiy was in fact controlled by surface oxide layers. It was found that a layer of beryllium oxide could be formed on Cu+2% Be and a layer of aluminum oxide could be formed on Cu+7% Al+2% Si. As compared to 0.25 mm-thick copper, the deuterium permeability at 500 0 C was reduced by a factor of approx.250 for Cu--Be and approx.1000 for Cu--Al--Si. The activation energies for deuterium permeation were 98 kJ/mol and 132 kJ/mol, respectively. The mechanism for the oxide growth is the high-temperature hydrogen reduction of nearby less stable oxides, simultaneous with oxidation of the active metal, Be or Al, by trace amounts of water in the hydrogen. Ion microprobe mass analysis identified the oxide layers as containing beryllium or aluminum but not containing copper

  1. Oxygen permeation flux through La1-ySryFeO3 limited by the carbon monoxide oxidation rate

    NARCIS (Netherlands)

    van Hassel, B.A.; van Hassel, B.A.; ten Elshof, Johan E.; Bouwmeester, Henricus J.M.

    1995-01-01

    The oxygen permeation flux through La1-ySryFeO3-δ (y = 0.1, 0.2) in a large oxygen partial pressure gradient (air/CO, CO2 mixture) was found to be limited by the carbon monoxide oxidation rate at the low oxygen partial pressure side of the membrane. The oxygen permeation flux through the membrane

  2. Liquid and Gas Permeation Studies on the Structure and Properties of Polyamide Thin-Film Composite Membranes

    KAUST Repository

    Duan, Jintang

    2014-01-01

    layer by gas adsorption and gas permeation measurements. Gas adsorption isotherms (N2 at 77K, CO2 at 273K) confirmed the microporous nature of PA in comparison with dense CTA and polysulfone materials. Gas permeation through the commercial PA

  3. Efficient ethanol recovery from fermentation broths with integrated distillation-vapor permeation hybrid process

    Science.gov (United States)

    The energy demand of distillation-molecular sieve systems for ethanol recovery/dehydration can be significant, particularly for dilute solutions. An alternative hybrid process integrating vapor stripping (like a beer still) with vapor compression and a vapor permeation membrane s...

  4. Gas-permeation properties of poly(ethylene oxide) poly(butylene terephthalate block copolymers

    NARCIS (Netherlands)

    Metz, S.J.; Mulder, M.H.V.; Wessling, Matthias

    2004-01-01

    This paper reports the gas-permeation properties of poly(ethylene oxide) (PEO) poly(butylene terephthalate) (PBT) segmented multiblock copolymers. These block copolymers allow a precise structural modification by the amount of PBT and the PEO segment length, enabling a systematic study of the

  5. CO2 permeation properties of poly(ethylene oxide)-based segmented block copolymers

    NARCIS (Netherlands)

    Husken, D.; Visser, Tymen; Wessling, Matthias; Gaymans, R.J.

    2010-01-01

    This paper discusses the gas permeation properties of poly(ethylene oxide) (PEO)-based segmented block copolymers containing monodisperse amide segments. These monodisperse segments give rise to a well phase-separated morphology, comprising a continuous PEO phase with dispersed crystallised amide

  6. On the intrinsic moisture permeation rate of remote microwave plasma-deposited silicon nitride layers

    NARCIS (Netherlands)

    van Assche, F. J. H.; Unnikrishnan, S.; Michels, J. J.; van Mol, A. M. B.; van de Weijer, P.; M. C. M. van de Sanden,; Creatore, M.

    2014-01-01

    We report on a low substrate temperature (110 °C) remote microwave plasma-enhanced chemical vapor deposition (PECVD) process of silicon nitride barrier layers against moisture permeation for organic light emitting diodes (OLEDs) and other moisture sensitive devices such as organic

  7. Permeation tubes. Their use in the preparation of controlled gas atmospheres

    International Nuclear Information System (INIS)

    Galianos, J. A.; Palomares, F.

    1981-01-01

    In this paper, the state of the art on the nature, construction and properties of the permeation tubes Is reviewed; after describing the main calibration procedures In use, examples of their application in the area of the atmospheric pollution are given, especially in the case of sulfur dioxides. (Author) 38 refs

  8. Deuterium permeation of amorphous alumina coating on 316L prepared by MOCVD

    International Nuclear Information System (INIS)

    Li Shuai; He Di; Liu Xiaopeng; Wang Shumao; Jiang Lijun

    2012-01-01

    Highlights: ► Deuterium permeation behavior of alumina coating by MOCVD is investigated. ► The as-prepared alumina is amorphous. ► The alumina coating is dense and well adherent to substrate. ► Deuterium permeation rate of alumina coating is 2–3 orders of magnitude lower than martensitic steels. - Abstract: The deuterium permeation behavior of the alumina coating on 316L stainless steel prepared by metal organic chemical vapor deposition (MOCVD) was investigated. The alumina coating was also characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscope (SEM). It was found that the as-prepared coating consisted of amorphous alumina. This alumina coating had a dense, crack-free and homogeneous morphology. Although the alumina coating was amorphous, effective suppression of deuterium permeation was demonstrated. The deuterium permeability of the alumina coating was 51–60 times less than that of the 316L stainless steel and 153–335 times less than that of the referred low activation martensitic steels at 860–960 K.

  9. Measurement of blood-brain barrier permeation in rats during exposure to 2450-MHz microwaves

    International Nuclear Information System (INIS)

    Ward, T.R.; Elder, J.A.; Long, M.D.; Svendsgaard, D.

    1982-01-01

    Adult rats anesthesized with pentobarbital and injected intravenously with a mixture of [ 14 C] sucrose and [ 3 H] inulin were exposed for 30 min to an environment at an ambient temperature of 22, 30, or 40 degrees C, or were exposed at 22 degrees C to 2450-MHz CW microwave radiation at power densities of 0, 10, 20, or 30 mW/cm2. Following exposure, the brain was perfused and sectioned into eight regions, and the radioactivity in each region was counted. The data were analyzed by two methods. First, the data for each of the eight regions and for each of the two radioactive tracers were analyzed by regression analysis for a total of 16 analyses and Bonferroni's Inequality was applied to prevent false positive results from numerous analyses. By this conservative test, no statistically significant increase in permeation was found for either tracer in any brain region of rats exposed to microwaves. Second, a profile analysis was used for a general change in tracer uptake across all brain regions. Using this statistical method, a significant increase in permeation was found for sucrose but not for inulin. A correction factor was then derived from the warm-air experiments to correct for the increase in permeation of the brain associated with change in body temperature. This correction factor was applied to the data for the irradiated animals. After correcting the data for thermal effects of the microwave radiation, no significant increase in permeation was found

  10. Ionic conductivity of perovskite LaCoO3 measured by oxygen permeation technique

    NARCIS (Netherlands)

    Chen, C.H.; Kruidhof, H.; Bouwmeester, Henricus J.M.; Burggraaf, Anthonie; Burggraaf, A.J.

    1997-01-01

    Oxygen permeation measurement is demonstrated, not only for a mixed oxide ionic and electronic conductor, but also as a new alternative to determine ambipolar conductivities, which can be usually reduced to be partial conductivities (either ionic or electronic). As a model system and an end member

  11. Investigating the influence of diffusional coupling on mixture permeation across porous membranes

    NARCIS (Netherlands)

    Krishna, R.; van Baten, J.M.

    2013-01-01

    A careful analysis of published experimental data on permeation of a variety of binary mixtures reveals that there are fundamentally two types of diffusional coupling effects that need to be recognized. The first type of coupling occurs when the less-mobile species slows down its more mobile partner

  12. Hydrogen permeation through sol-gel-coated iron during galvanostatic charging

    International Nuclear Information System (INIS)

    Zakorchemna, I.; Carmona, N.; Zakroczymski, T.

    2008-01-01

    One-layer sol-gel silica-zirconia and two-layer silica-zirconia and zirconia coatings were deposited on one side of iron membranes by spin-coating, densified in air and annealed up to 800 deg. C in vacuum. Hydrogen permeation through the membranes, coated and uncoated, polarised cathodically under galvanostatic control in 0.1 M NaOH solution was studied using the electrochemical permeation technique. During the initial period, the effect of the sol-gel coatings was insignificant. However, the coatings quite efficiently prevented the iron surface become more active to hydrogen entry during a long-lasting cathodic polarisation. In addition, the electrochemical-corrosion behaviour of the coated iron and the effect of the sol-gel coatings on the effective diffusivity of hydrogen in the coated membranes were studied. On the basis of the polarisation curves and the hydrogen permeation data it was proved that the sol-gel coatings blocked the iron surface for the hydrogen evolution reaction and, consequently, for the hydrogen entry into iron. The effective coating coverage was determined by comparison of the hydrogen fluxes permeating the coated and uncoated membranes. Finally the real concentration of hydrogen beneath the uncoated iron sites and the amount of hydrogen stored in a membrane were evaluated

  13. A novel microdialysis-dissolution/permeation system for testing oral dosage forms

    DEFF Research Database (Denmark)

    Fong, Sophia Yui Kau; Poulsen, Jessie; Brandl, Martin

    2016-01-01

    A novel microdialysis-dissolution/permeation (M-D/P) system was developed for the biopharmaceutical assessment of oral drug formulations. This system consists of a side-by-side diffusion chamber, a microdialysis unit fixed within the dissolution chamber for continuous sampling, and a biomimetic P...

  14. Corrosion and hydrogen permeation of A216 Grade WCA steel in hydrothermal magnesium-containing brines

    International Nuclear Information System (INIS)

    Haberman, J.H.; Frydrych, D.J.; Westerman, R.E.

    1988-03-01

    Corrosion rates determined at 1 month in 150/degree/C brine increased with magnesium concentration. The structure of the corrosion product, as determined by x-ray diffraction, depended upon the magnesium concentration. In brines with less than 10,000 ppM magnesium, the primary corrosion product had a spinel structure characteristic of magnetite or magnesioferrite. In brines containing magnesium concentrations greater than 20,000 ppM, the primary corrosion product had the amakinite structure characteristic of a complex iron-magnesium hydroxide. The high corrosion rates observed in brines containing high magnesium concentrations suggest that the corrosion products having the amakinite structure is less protective than corrosion products having the spinel structure. Corrosion rates in high-magnesium (inclusion) brine determined over a 6-month test duration were essentially constant. Hydrogen permeation rates observed in exposing mild steel to high-Mg/sup 2/plus// brine at 150/degree/C could be potentially damaging to a mild steel waste package container. The rate of hydrogen permeation was proportional to the brine flow rate in the autoclave. Thiourea additions to the brine increased the hydrogen permeation rate; sulfate and bromide ion additions did not. The maximum gaseous hydrogen pressure attainable is not known (based on 3Fe /plus/ 4H 2 O /plus/ Fe(sub 3)O /plus/ 4H 2 , would be /approximately/900 atmospheres), and the dependence of permeation rate on temperature is not known. 8 refs., 13 figs., 3 tabs

  15. Preparation, characterization and permeation studies of a nanovesicular system containing diclofenac for transdermal delivery.

    Science.gov (United States)

    Gaur, Praveen Kumar; Purohit, Suresh; Kumar, Yatendra; Mishra, Shikha; Bhandari, Anil

    2014-02-01

    Transdermal formulations contain permeation enhancer which causes skin damage. Ceramide 2 is natural lipid found in stratum corneum (SC). Drug-loaded nanovesicles of ceramide-2, cholesterol, palmitic acid, cholesteryl sulfate were formulated and analyzed for physical and biological properties. Diclofenac was used as a model drug. The vesicles were prepared using the film hydration method and characterized for physical parameters, in vitro drug release, accelerated stability studies and formulated into gel. Respective gels were compared with a commercial formulation (CEG) and plain carbopol gel (CG) containing drug for ex vivo, in vivo drug permeation and anti-inflammatory activity. The vesicles were stable with optimum physical parameters. DCG-1 showed 92.89% in vitro drug release. Ceramide vesicles showed drug release between 18 and 25 μg/cm(2) whereas CG and CEG released 0.33 and 1.35 μg/cm(2) drug, respectively. DCG-1 and CEG showed corresponding Cmax at 6 and 4 h, respectively. DCG-1 showed six times AUC than CEG. DCG-1 inhibited edema by 86.37% by 4th hour of application. The presence of ceramide 2 specifically promotes the drug permeation through SC and dermis and also contribute towards stability and non-irritancy. The composition of the nanovesicle played an important role in physical properties and drug permeation.

  16. Vapor Permeation and Pervaporation of Propan- 1-ol and Propan- 2-ol in Polyethylene Membrane

    Czech Academy of Sciences Publication Activity Database

    Uchytil, Petr; Petričkovič, Roman

    2002-01-01

    Roč. 209, - (2002), s. 67-79 ISSN 0376-7388 R&D Projects: GA ČR GA104/01/0945 Keywords : vapor permeation * pervaporation * sorption Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.965, year: 2002

  17. Deuterium permeation measurements on tungsten using ion-beam-based detection

    Energy Technology Data Exchange (ETDEWEB)

    Kapser, Stefan [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Physik-Department, Technische Universitaet Muenchen, James-Franck-Str. 1, 85748 Garching (Germany); Manhard, Armin; Toussaint, Udo von [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany)

    2016-07-01

    Tungsten (W) is promising for the inner wall of a future fusion reactor, where it will be exposed to high fluxes of hydrogen (H) isotopes. Knowledge of their diffusion in W is important for safety and economic considerations, particularly concerning tritium. A common method to investigate H diffusion in metals are permeation experiments. Typically, gas loading and mass-spectrometric detection are used. Information about the diffusion can be gained from the temporal evolution of the permeation flux, whose magnitude is determined by the permeability (product of diffusivity and solubility). However, for low-permeability metals, the permeation flux can be unmeasurably small. For W this is the case near room temperature. We present a method that circumvents this problem. It is an improved version of experiments on nickel and stainless steel. The W is exposed to deuterium (D) plasma on one side and the permeating D is accumulated in a getter on the other side. A cover prevents D gettering from the gas phase. The amount in the getter is analysed by the nuclear reaction D({sup 3}He,p){sup 4}He.

  18. Fully automatic flow-based device for monitoring of drug permeation across a cell monolayer.

    Science.gov (United States)

    Zelená, Lucie; Marques, Sara S; Segundo, Marcela A; Miró, Manuel; Pávek, Petr; Sklenářová, Hana; Solich, Petr

    2016-01-01

    A novel flow-programming setup based on the sequential injection principle is herein proposed for on-line monitoring of temporal events in cell permeation studies. The permeation unit consists of a Franz cell with its basolateral compartment mixed under mechanical agitation and thermostated at 37 °C. The apical compartment is replaced by commercially available Transwell inserts with a precultivated cell monolayer. The transport of drug substances across epithelial cells genetically modified with the P-glycoprotein membrane transporter (MDCKII-MDR1) is monitored on-line using rhodamine 123 as a fluorescent marker. The permeation kinetics of the marker is obtained in a fully automated mode by sampling minute volumes of solution from the basolateral compartment in short intervals (10 min) up to 4 h. The effect of a P-glycoprotein transporter inhibitor, verapamil as a model drug, on the efficiency of the marker transport across the cell monolayer is thoroughly investigated. The analytical features of the proposed flow method for cell permeation studies in real time are critically compared against conventional batch-wise procedures and microfluidic devices.

  19. Investigation on hydrogen permeation on heat exchanger materials in conditions of steam coal gasification

    International Nuclear Information System (INIS)

    Moellenhoff, H.

    1984-01-01

    The permeation of hydrogen through iron-based alloys of different compositions in the temperature range between 700 and 1000 0 C was examined in a laboratory fluidized bed in the conditions of steam/coal gasification. Apart from tests on bright metal samples, measurement in the gasification atmosphere at a maximum pressure of 1 bar were carried out during oxidation of the metal. Experiments in a steam/hydrogen/argon mixture with the same oxidation potential were used for comparison purposes. The hydrogen permeated through the metal sample was taken to a gas chromatograph with argon flushing gas and analyzed there. The investigations on bright steel samples of various composition showed that their permeabilities for hydrogen at temperatures around 900 0 C only differed by a maximum of ± 30%. Effective prevention of permeation is therefore not possible simply by choosing a suitable alloy. If the steels are oxidized during permeation measurements, there is a reduction of the hydrogen permeability by 2 or 3 orders of magnitude due to the oxidation process, both in the steam/coal gasification fluidized bed and in a pure steam/hydrogen/argon mixture. (orig./GG) [de

  20. Reduction of tritium permeation through Inconel 718 and Incoloy 800 HT by means of natural oxides

    Energy Technology Data Exchange (ETDEWEB)

    Aiello, A., E-mail: antonio.aiello@enea.it [ENEA C.R. Brasimone, I-40032 Camugnano (Italy); Utili, M.; Ciampichetti, A. [ENEA C.R. Brasimone, I-40032 Camugnano (Italy)

    2011-10-01

    Chronical releases of tritium from the helium primary coolant into the water secondary coolant is a fundamental safety issue in the design of a fusion reactor steam generator. It is well known that the steam/water circuit of a fusion reactor would be considered not relevant from a radiological point of view, while if a strong permeation of tritium will be present it will be released together with incondensable gases in the condenser. The permeation of hydrogen isotopes through candidate steam generator materials in different conditions was studied in the past. Further experiments demonstrated that nickel alloys of nuclear interest are always covered by a thin and adherent oxide layer able to reduce permeation of orders of magnitude. The major objective of this work is the evaluation of the permeated flux through nickel alloys, when exposed to pure hydrogen and to an oxidant gas stream, to verify the real permeability of these materials in conditions close to those foreseen in the helium side of the steam generator.

  1. LIBRETTO-3: Performance of tritium permeation barriers under irradiation at the HFR Petten

    International Nuclear Information System (INIS)

    Conrad, R.; Fuetterer, M.A.; Giancarli, L.; May, R.; Perujo, A.; Sample, T.

    1994-01-01

    The LIBRETTO-3 irradiation was performed at the HFR Petten during 77 full power days in three cycles to compare the efficiency of three different tritium permeation barriers in presence of Pb-17Li to uncoated AISI 316L steel. For this purpose four steel capsules (arnothing o =10 mm, arnothing i =8 mm, l=300 mm) were filled with 28 g Pb-17Li. The coatings included CVD TiC (outside), CVD TiC+Al 2 O 3 (inside), and pack cementation aluminisation (inside). The generated tritium was partly extracted by bubbling, partly it permeated through the capsules. Permeated and extracted tritium were measured as a function of temperature (280-450 C), H 2 doping (0-1 vol%) and purge gas flow rate. The driving partial pressure in the coated capsules were from an extraction model calibrated by the uncoated capsule for which tritium partial pressure could be calculated. In LIBRETTO-3 conditons, the best barrier was pack cementation aluminisation. The first interpretation of the experiment could, however, not confirm permeation reduction factors of 100 or more expected from this barrier. ((orig.))

  2. Water Vapor Permeation of Metal Oxide/Polymer Coated Plastic Films

    Science.gov (United States)

    Numata, Yukihiro; Oya, Toshiyuki; Kuwahara, Mitsuru; Ito, Katsuya

    Barrier performance to water vapor permeation of ceramic coated layers deposited on flexible polymer films is of great interest to food packaging, medical device packaging and flat panel display industries. In this study, a new type film in which a ceramic layer is deposited on a polymer coated film was proposed for lower water vapor permeation. It is important how to control interfacial properties between each layer and film for good barrier performance. Several kinds of polymer coated materials were prepared for changing surface free energy of the films before and after depositing the ceramic layer. The ceramic layer, which is composed of mixed material of SiO2 and Al2O3, was adopted under the same conditions. The following results were obtained; 1) Water vapor permeation is not related to the surface energy of polymer coated films, 2) After depositing the ceramic layer, however, a strong correlation is observed between the water vapor permeation and surface free energy. 3) The phenomenon is considered that the polarity of the polymer layers plays a key role in changing the structure of ceramic coated layers.

  3. Multi-response data treatment of dynamic and steady state permeation measurement on composite membrane

    Czech Academy of Sciences Publication Activity Database

    Fíla, V.; Bernauer, B.; Hrabánek, Pavel

    2006-01-01

    Roč. 200, 1-3 (2006), s. 120-121 ISSN 0011-9164 R&D Projects: GA AV ČR(CZ) 1QS401250509 Institutional research plan: CEZ:AV0Z40400503 Keywords : composite membrane * physical chemistry * Wicke-Kalenbach permeation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.917, year: 2006

  4. Long time effects in radiation enhanced permeation of H2 through stainless steel tubes

    International Nuclear Information System (INIS)

    Schwarzinger, G.; Dobrozemsky, R.

    1982-01-01

    The aim of this research is to give the particulars of influences of penetrating radiation on permeation and diffusion processes of hydrogen isotopes in stainless steel. Short time as well as long time effects have been investigated. Such processes are not only of interest for the fuel inventory of fusion reactors, but also for environmental aspects (tritium release). (Author)

  5. Effect of Bile Salt on Permeation Characteristics of the Oral Mucosal ...

    African Journals Online (AJOL)

    An attempt was made to study the effect of bile salt [sodium glycocholate (SG)] as a permeation enhancer on mucoadhesive buccal patches of diltiazem hydrochloride (anti-anginal drug) using various polymers like hydroxypropyl methyl cellulosee (HPMC), Eudragit RL100, ethyl cellulose alone and in combination with PVP.

  6. Novel diffusion cell for in vitro transdermal permeation, compatible with automated dynamic sampling

    NARCIS (Netherlands)

    Bosman, I.J; Lawant, A.L; Avegaart, S.R.; Ensing, K; de Zeeuw, R.A

    The development of a new diffusion cell for in vitro transdermal permeation is described. The so-called Kelder cells were used in combination with the ASPEC system (Automatic Sample Preparation with Extraction Columns), which is designed for the automation of solid-phase extractions (SPE). Instead

  7. Prediction of Permeation Resistance of Protective Gloves, etc. from Solubility Parameters

    DEFF Research Database (Denmark)

    Henriksen, H. Risvig; Madsen, Jørgen Øgaard

    1997-01-01

    ). A starting point was the authoritative conclusion (Coletta et al., 1978), that permeation in protective clothing could not be predicted. As a spin off, the predictive concept indicated that new types of polymers sometimes should be incorporated to reach a reasonable (long) breakthrough time and (low...

  8. Gas Permeation Related to the Moisture Sorption in Films of Glassy Hydrophilic Polymers

    NARCIS (Netherlands)

    Laksmana, F. L.; Kok, P. J. A. Hartman; Frijlink, H. W.; Vromans, H.; Maarschalk, K. Van Der Voort

    2010-01-01

    The purpose of this article is to elucidate the effect of integral sorption of moisture on gas permeation in glassy hydrophilic polymers. The oxygen and the simultaneous moisture sorption into various hydroxypropyl methylcellulose (HPMC) films were measured under a wide range of relative humidities

  9. Dynamic dissolution-/permeation-testing of nano- and microparticle formulations of fenofibrate

    DEFF Research Database (Denmark)

    Sironi, Daniel; Rosenberg, Jörg; Bauer-Brandl, Annette

    2017-01-01

    -/ or nanoparticle-formulation was tested. Nondissolved nano-/microparticles served as a reservoir helping to maintain high levels of molecularly dissolved drug, which in turn caused high and constant permeation rates. The micelle-bound drug may also serve as a drug-reservoir, yet of subordinate importance as long...

  10. Surface oxygen vacancy and oxygen permeation flux limits of perovskite ion transport membranes

    KAUST Repository

    Hunt, Anton

    2015-09-01

    © 2015 Elsevier B.V. The mechanisms and quantitative models for how oxygen is separated from air using ion transport membranes (ITMs) are not well understood, largely due to the experimental complexity for determining surface exchange reactions at extreme temperatures (>800°C). This is especially true when fuels are present at the permeate surface. For both inert and reactive (fuels) operations, solid-state oxygen surface vacancies (δ) are ultimately responsible for driving the oxygen flux, JO2. In the inert case, the value of δ at either surface is a function of the local PO2 and temperature, whilst the magnitude of δ dictates both the JO2 and the inherent stability of the material. In this study values of δ are presented based on experimental measurements under inert (CO2) sweep: using a permeation flux model and local PO2 measurements, collected by means of a local gas-sampling probe in our large-scale reactor, we can determine δ directly. The ITM assessed was La0.9Ca0.1FeO3-δ (LCF); the relative resistances to JO2 were quantified using the pre-defined permeation flux model and local PO2 values. Across a temperature range from 825°C to 1056°C, δ was found to vary from 0.007 to 0.029 (<1%), safely within material stability limits, whilst the permeate surface exchange resistance dominates. An inert JO2 limit was identified owing to a maximum sweep surface δ, δmaxinert. The physical presence of δmaxinert is attributed to a rate limiting step shift from desorption to associative electron transfer steps on the sweep surface as PO2 is reduced. Permeate surface exchange limitations under non-reactive conditions suggest that reactive (fuel) operation is necessary to accelerate surface chemistry for future work, to reduce flux resistance and push δpast δmaxinert in a stable manner.

  11. Pervaporation membrane bioreactor with permeate fractional condensation and mechanical vapor compression for energy efficient ethanol production

    International Nuclear Information System (INIS)

    Fan, Senqing; Xiao, Zeyi; Li, Minghai; Li, Sizhong

    2016-01-01

    Graphical abstract: Pervaporation membrane bioreactor with permeate partial condensation and mechanical vapor compression is developed for an energy efficient ethanol production. - Highlights: • PVMBR-MVC for energy efficient ethanol production. • Process separation factor of 20–44 for ethanol achieved by fractional condensation. • Energy production of 20.25 MJ and hourly energy production of 56.25 kJ/h achieved. • Over 50% of energy saved in PVMBR-MVC compared with PVMBR-LTC. • Integrated heat pump with COP of 7–9 for the energy recovery of the permeate. - Abstract: Improved process separation factor and heat integration are two key issues to increase the energy efficiency of ethanol production in a pervaporation membrane bioreactor (PVMBR). A PVMBR with permeate fractional condensation and mechanical vapor compression was developed for energy efficient ethanol production. A condensation model based on the mass balance and thermodynamic equilibrium in the partial vacuum condenser was developed for predicting the purification performance of the permeate vapor. Three runs of ethanol fermentation-pervaporation experiment were carried out and ethanol concentration of higher than 50 wt% could be achieved in the final condensate, with the separation factor of the process for ethanol increased to 20. Ethanol production could be enhanced in the bioreactor and 17.1 MJ of the energy could be produced in per liter of fermentation broth, owing to 27.0 MJ/kg heating value of the recovered ethanol. Compared with the traditional pervaporation process with low temperature condensation for ethanol production, 50% of the energy would be saved in the process. The energy consumption would be further reduced, if the available energy of the permeate vapor was utilized by integrating the mechanical vapor compression heat pump.

  12. Influence of bulk and surface phenomena on the hydrogen permeation through metals

    International Nuclear Information System (INIS)

    Waelbroeck, F.; Wienhold, P.; Winter, J.; Rota, E.; Bauno, T.

    1984-12-01

    We discuss the permeation of hydrogen through metals and alloys such as iron, nickel, steels and Inconel wherein H dissolves endothermically from an H 2 gas. We assume first that trapping centers, surface contamination layers, the saturation of the H surface coverage and the implantation profile - when energetic ions drive the permeation - can be neglected, that a quasi-equilibrium exists between the H atom concentration ν in the adsorbed layer and c in the near surface layers and that the H solubility and diffusivity are homogeneous in the membrane. We evaluate thereafter separately the influence of these various effects and identify the parameter domains where appreciable corrections result. The permeation phenomenon is complex even when these simplifications are made: the penetration rate is proportional to the flux of thermal molecules, atoms or energetic ions - depending upon the case - which strike the surface; the diffusion in the metal is proportional to the gradient of c; the release rate depends on c 2 ; the time-dependent diffusion equation includes a double spatial derivative of c. Permeation can only be fully described when computer codes such as PERI is used. Simple analytical relations are however obtained in several limiting cases. They are the object of this report. Some of them had already been derived by other authors but they were not shown to be part of a single, self consistent permeation model. A comparison of predicted and experimental results shows that the simplified model describes surprisingly accurately the hydrogen exchange between gas and metal solutions. (orig./GSCH)

  13. Seawater ultrafiltration fouling control: Backwashing with demineralized water/SWRO permeate

    KAUST Repository

    Li, Sheng; Heijman, Sebastiaan G J; Verberk, J. Q J C; Amy, Gary L.; Van Dijk, Johannis C.

    2012-01-01

    In this study, the effect of demineralized water backwashing on fouling control of seawater ultrafiltration was investigated. Seawater from Scheveningen beach in The Hague and a desalination plant of Evides Company at Zeeland in the Netherlands was used as feed water, while demineralized water and UF permeate were used as backwash water for a fouling control efficiency comparison under different fluxes and backwash durations. Furthermore, demineralized waters with 5 or 50 mmol/l NaCl were applied for backwashing as well, to check the influence of monovalent cations on UF fouling control. Additionally, SWRO permeate was used for backwashes in long-term experiments to check the possibility of it replacing demineralized water. Results show that seawater UF fouling control is substantially improved by demineralized water backwashing. However, due to the high salinity of seawater, more water was required to dilute the cation concentration and limit the dispersion effect near the membrane surface than was needed for surface water. A 2-min demineralized water backwash showed better fouling control efficiency than a 1-min backwash. Furthermore, the presence of monovalent cations in the backwash water deteriorated the fouling control efficiency of the backwash, indicating the existence of a charge screening effect. The demineralized water with 5 and 50 mmol/l NaCl both showed a similar fouling control efficiency which is better than the UF permeate backwash. The calcium ions in UF permeate probably deteriorates the fouling control efficiency by maintaining a Ca-bridging effect between the membranes and NOM. SWRO permeate backwashing successfully controls membrane fouling as well. © 2012 Elsevier B.V. All rights reserved.

  14. Permeation of gasoline, diesel, bioethanol (E85), and biodiesel (B20) fuels through six glove materials.

    Science.gov (United States)

    Chin, Jo-Yu; Batterman, Stuart A

    2010-07-01

    Biofuels and conventional fuels differ in terms of their evaporation rates, permeation rates, and exhaust emissions, which can alter exposures of workers, especially those in the fuel refining and distribution industries. This study investigated the permeation of biofuels (bioethanol 85%, biodiesel 20%) and conventional petroleum fuels (gasoline and diesel) through gloves used in occupational settings (neoprene, nitrile, and Viton) and laboratories (latex, nitrile, and vinyl), as well as a standard reference material (neoprene sheet). Permeation rates and breakthrough times were measured using the American Society for Testing and Materials F739-99 protocol, and fuel and permeant compositions were measured by gas chromatography/mass spectrometry. In addition, we estimated exposures for three occupational scenarios and recommend chemical protective clothing suitable for use with motor fuels. Permeation rates and breakthrough times depended on the fuel-glove combination. Gasoline had the highest permeation rate among the four fuels. Bioethanol (85%) had breakthrough times that were two to three times longer than gasoline through neoprene, nitrile Sol-Vex, and the standard reference materials. Breakthrough times for biodiesel (20%) were slightly shorter than for diesel for the latex, vinyl, nitrile examination, and the standard neoprene materials. The composition of permeants differed from neat fuels, e.g., permeants were significantly enriched in the lighter aromatics including benzene. Viton was the best choice among the tested materials for the four fuels tested. Among the scenarios, fuel truck drivers had the highest uptake via inhalation based on the personal measurements available in the literature, and gasoline station attendants had highest uptake via dermal exposure if gloves were not worn. Appropriate selection and use of gloves can protect workers from dermal exposures; however, current recommendations from the National Institute for Occupational Safety and

  15. Permeation mechanisms of pulsed microwave plasma deposited silicon oxide films for food packaging applications

    International Nuclear Information System (INIS)

    Deilmann, Michael; Grabowski, Mirko; Theiss, Sebastian; Bibinov, Nikita; Awakowicz, Peter

    2008-01-01

    Silicon oxide barrier layers are deposited on polyethylene terephthalate as permeation barriers for food packaging applications by means of a low pressure microwave plasma. Hexamethyldisiloxane (HMDSO) and oxygen are used as process gases to deposit SiO x coatings via pulsed low pressure plasmas. The layer composition of the coating is investigated by Fourier transform infrared spectroscopy and energy dispersive x-ray spectroscopy to show correlations with barrier properties of the films. The oxygen permeation barrier is determined by the carrier gas method using an electrochemical detector. The transition from low to high barrier films is mapped by the transition from organic SiO x C y H z layers to quartz-like SiO 1.7 films containing silanol bound hydrogen. A residual permeation as low as J = 1 ± 0.3 cm 3 m -2 day -1 bar -1 is achieved, which is a good value for food packaging applications. Additionally, the activation energy E p of oxygen permeation is analysed and a strong increase from E p = 31.5 kJ mol -1 for SiO x C y H z -like coatings to E p = 53.7 kJ mol -1 for SiO 1.7 films is observed by increasing the oxygen dilution of HMDSO:O 2 plasma. The reason for the residual permeation of high barrier films is discussed and coating defects are visualized by capacitively coupled atomic oxygen plasma etching of coated substrates. A defect density of 3000 mm -2 is revealed

  16. Seawater ultrafiltration fouling control: Backwashing with demineralized water/SWRO permeate

    KAUST Repository

    Li, Sheng

    2012-09-01

    In this study, the effect of demineralized water backwashing on fouling control of seawater ultrafiltration was investigated. Seawater from Scheveningen beach in The Hague and a desalination plant of Evides Company at Zeeland in the Netherlands was used as feed water, while demineralized water and UF permeate were used as backwash water for a fouling control efficiency comparison under different fluxes and backwash durations. Furthermore, demineralized waters with 5 or 50 mmol/l NaCl were applied for backwashing as well, to check the influence of monovalent cations on UF fouling control. Additionally, SWRO permeate was used for backwashes in long-term experiments to check the possibility of it replacing demineralized water. Results show that seawater UF fouling control is substantially improved by demineralized water backwashing. However, due to the high salinity of seawater, more water was required to dilute the cation concentration and limit the dispersion effect near the membrane surface than was needed for surface water. A 2-min demineralized water backwash showed better fouling control efficiency than a 1-min backwash. Furthermore, the presence of monovalent cations in the backwash water deteriorated the fouling control efficiency of the backwash, indicating the existence of a charge screening effect. The demineralized water with 5 and 50 mmol/l NaCl both showed a similar fouling control efficiency which is better than the UF permeate backwash. The calcium ions in UF permeate probably deteriorates the fouling control efficiency by maintaining a Ca-bridging effect between the membranes and NOM. SWRO permeate backwashing successfully controls membrane fouling as well. © 2012 Elsevier B.V. All rights reserved.

  17. Construction and performance test of apparatus for permeation experiments with controlled surfaces

    International Nuclear Information System (INIS)

    Hatano, Yuji; Nomura, Mamoru; Watanabe, Kuniaki; Livshits, Alexander I.; Busnyuk, Andrei O.; Nakamura, Yukio; Ohyabu, Nobuyoshi

    2003-01-01

    A new apparatus was constructed to examine gas-, atom- and plasma-driven permeation of hydrogen isotopes through group VA metal membranes with precisely controlled surface states. Absorption and desorption experiments are also possible. The new apparatus consists of two vacuum chambers, an upstream chamber and a downstream chamber, separated by a specimen membrane. Both chambers are evacuated by turbo-molecular pumps and sputter-ion pumps. The upstream chamber is equipped with Ta filaments serving as atomizers in atom-driven permeation experiments and cathodes in plasma-driven permeation experiments. The specimen membrane is formed into a tubular shape and electrically isolated from the chamber. Hence, ohmic heating of the membrane is possible, and this feature of the membrane is suitable for surface cleaning by high-temperature heating an impurity doping for the control of surface chemical composition through surface segregation. Both chambers were evacuated to 1 x 10 -7 Pa after baking. The main component of residual gas was H 2 , and the partial pressures of impurity gases other than H 2 were ca. 1 x 10 -8 Pa. Gas- and atom-driven permeation experiments were successfully carried out with hydrogen gas for Nb membrane activated by heating in vacuum at 1173 K. Superpermeation was observed in the atom-driven permeation experiments. Absorption experiments with a clean surface were also carried out. The surface was, however, cleaned only partially, because the temperature distribution was not uniform during high-temperature heating. Nevertheless, surface cleanliness was retained during absorption experiments under the present vacuum conditions. A new membrane assembly that will enable a uniform temperature distribution is now under construction. (author)

  18. Permeation of iodide from iodine-enriched yeast through porcine intestine.

    Science.gov (United States)

    Ryszka, Florian; Dolińska, Barbara; Zieliński, Michał; Chyra, Dagmara; Dobrzański, Zbigniew

    2013-01-01

    Iodine deficiency is a common phenomenon, threatening the whole global human population. Recommended daily intake of iodine is 150 μg for adults and 250 μg for pregnant and breastfeeding women. About 50% of human population can be at risk of moderate iodine deficiency. Due to this fact, increased iodine supplementation is recommended, through intake of iodized mineral water and salt iodization. The aim of this study was to investigate permeation and absorption of iodide from iodine bioplex (experimental group) in comparison with potassium iodide (controls). Permeation and absorption processes were investigated in vitro using a porcine intestine. The experimental model was based on a standard Franz diffusion cell (FD-Cell). The iodine bioplex was produced using Saccharomyces cerevisiae yeast and whey powder: iodine content - 388 μg/g, total protein - 28.5%, total fat - 0.9%., glutamic acid - 41.2%, asparaginic acid - 29.4%, lysine - 24.8%; purchased from: F.Z.N.P. Biochefa, Sosnowiec, Poland. Potassium iodide was used as controls, at 388 μg iodine concentration, which was the same as in iodine-enriched yeast bioplex. A statistically significant increase in iodide permeation was observed for iodine-enriched yeast bioplex in comparison with controls - potassium iodide. After 5h the total amount of permeated iodide from iodine-enriched yeast bioplex was 85%, which is ~ 2-fold higher than controls - 37%. Iodide absorption was by contrast statistically significantly higher in controls - 7.3%, in comparison with 4.5% in experimental group with iodine-enriched yeast bioplex. Presented results show that iodide permeation process dominates over absorption in case of iodine-enriched yeast bioplex.

  19. What Is the Mechanism Behind Increased Permeation Rate of a Poorly Soluble Drug from Aqueous Dispersions of an Amorphous Solid Dispersion?

    DEFF Research Database (Denmark)

    Frank, K. J.; Westedt, U.; Rosenblatt, K. M.

    2014-01-01

    of amorphous microparticles present in aqueous dispersions induces lasting supersaturation maintaining enhanced permeation. The hypothesis is supported by a slower drug permeation when the microparticles were removed. (c) 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci...

  20. ISO specifications and unclear energy quality certification

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tae Hun

    2011-12-15

    This book indicates necessity of quality management and change of company environment, basic conception of quality management and thinking way, role of each class for quality management, necessity and purpose of introduction of ISO9000 family, authentication process and construct method of ISO9000 family, authentication effect of ISO9000 family, present condition of ISO9000 family, standard of quality certification and quality management and explanation of 2001 requirement of KSA9000.

  1. Benefits of nuclear reactor still unclear

    International Nuclear Information System (INIS)

    Allen, Barry

    1997-01-01

    The author questions the Australian Government decision to build a new reactor at Lucas Heights and to reject the proposal for a nuclear waste reprocessing and disposal using Australia's Synroc technology. He argued that Australia should have looked to the future(Synroc) instead of investing in dated technology (Reactor) and sees Synroc technology having much more potential to generate foreign currency if the increasing need for waste disposal facilities in the region are considered

  2. ISO specifications and unclear energy quality certification

    International Nuclear Information System (INIS)

    Lee, Tae Hun

    2011-12-01

    This book indicates necessity of quality management and change of company environment, basic conception of quality management and thinking way, role of each class for quality management, necessity and purpose of introduction of ISO9000 family, authentication process and construct method of ISO9000 family, authentication effect of ISO9000 family, present condition of ISO9000 family, standard of quality certification and quality management and explanation of 2001 requirement of KSA9000.

  3. Transcriptome and membrane fatty acid analyses reveal different strategies for responding to permeating and non-permeating solutes in the bacterium Sphingomonas wittichii

    Directory of Open Access Journals (Sweden)

    Johnson David R

    2011-11-01

    Full Text Available Abstract Background Sphingomonas wittichii strain RW1 can completely oxidize dibenzo-p-dioxins and dibenzofurans, which are persistent contaminants of soils and sediments. For successful application in soil bioremediation systems, strain RW1 must cope with fluctuations in water availability, or water potential. Thus far, however, little is known about the adaptive strategies used by Sphingomonas bacteria to respond to changes in water potential. To improve our understanding, strain RW1 was perturbed with either the cell-permeating solute sodium chloride or the non-permeating solute polyethylene glycol with a molecular weight of 8000 (PEG8000. These solutes are assumed to simulate the solute and matric components of the total water potential, respectively. The responses to these perturbations were then assessed and compared using a combination of growth assays, transcriptome profiling, and membrane fatty acid analyses. Results Under conditions producing a similar decrease in water potential but without effect on growth rate, there was only a limited shared response to perturbation with sodium chloride or PEG8000. This shared response included the increased expression of genes involved with trehalose and exopolysaccharide biosynthesis and the reduced expression of genes involved with flagella biosynthesis. Mostly, the responses to perturbation with sodium chloride or PEG8000 were very different. Only sodium chloride triggered the increased expression of two ECF-type RNA polymerase sigma factors and the differential expression of many genes involved with outer membrane and amino acid metabolism. In contrast, only PEG8000 triggered the increased expression of a heat shock-type RNA polymerase sigma factor along with many genes involved with protein turnover and repair. Membrane fatty acid analyses further corroborated these differences. The degree of saturation of membrane fatty acids increased after perturbation with sodium chloride but had the

  4. Transferosomes - A vesicular transdermal delivery system for enhanced drug permeation

    Directory of Open Access Journals (Sweden)

    Reshmy Rajan

    2011-01-01

    Full Text Available Transdermal administration of drugs is generally limited by the barrier function of the skin. Vesicular systems are one of the most controversial methods for transdermal delivery of active substances. The interest in designing transdermal delivery systems was relaunched after the discovery of elastic vesicles like transferosomes, ethosomes, cubosomes, phytosomes, etc. This paper presents the composition, mechanisms of penetration, manufacturing and characterization methods of transferosomes as transdermal delivery systems of active substances. For a drug to be absorbed and distributed into organs and tissues and eliminated from the body, it must pass through one or more biological membranes/barriers at various locations. Such a movement of drug across the membrane is called as drug transport. For the drugs to be delivered to the body, they should cross the membranous barrier. The concept of these delivery systems was designed in an attempt to concentrate the drug in the tissues of interest, while reducing the amount of drug in the remaining tissues. Hence, surrounding tissues are not affected by the drug. In addition, loss of drug does not happen due to localization of drug, leading to get maximum efficacy of the medication. Therefore, the phospholipid based carrier systems are of considerable interest in this era.

  5. Analysis of transient permeation behavior of hydrogen isotope caused by abrupt temperature change of first wall and blanket wall material

    International Nuclear Information System (INIS)

    Yamawaki, Michio; Tanaka, Satoru; Kiyoshi, Tsukasa

    1989-01-01

    To obtain further information on the transient permeation behavior of hydrogen isotopes as caused by an abrupt temperature change, numerical calculations were carried out for two typical metals, nickel and vanadium. Deuterium permeation through nickel is analyzed as a typical case of bulk-diffusion-limited permeation. Its transient behavior changed dramatically according to the specimen thickness. The transient behavior, in general, is separated into two parts, initial and latter period behaviors. Conditions which cause such a separation were evaluated. Evaluation of the hydrogen diffusivity and solubility by an analysis of transient curves of hydrogen permeation was carried out. The transient behavior of simultaneous gas- and ion-driven hydrogen permeation through vanadium was also analyzed. Overshooting of the hydrogen permeation rate appears with an abrupt temperature increase. Increasing the impinging ion flux causes the overshooting peak to become sharper, and also reduces the change of the steady-state permeation rate to be attained after the temperature change compared with the initial value. (orig.)

  6. Rationalizing the permeation of polar antibiotics into Gram-negative bacteria

    International Nuclear Information System (INIS)

    Scorciapino, Mariano Andrea; Acosta-Gutierrez, Silvia; Benkerrou, Dehbia; D’Agostino, Tommaso; Malloci, Giuliano; Samanta, Susruta; Bodrenko, Igor; Ceccarelli, Matteo

    2017-01-01

    The increasing level of antibiotic resistance in Gram-negative bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a global challenge for modern medicine. The main reason that Gram-negative bacteria are particularly challenging is the presence of an outer cell-protecting membrane, which is not present in Gram-positive species. Such an asymmetric bilayer is a highly effective barrier for polar molecules. Several protein systems are expressed in the outer membrane to control the internal concentration of both nutrients and noxious species, in particular: (i) water-filled channels that modulate the permeation of polar molecules and ions according to concentration gradients, and (ii) efflux pumps to actively expel toxic compounds. Thus, besides expressing specific enzymes for drugs degradation, Gram-negative bacteria can also resist by modulating the influx and efflux of antibiotics, keeping the internal concentration low. However, there are no direct and robust experimental methods capable of measuring the permeability of small molecules, thus severely limiting our knowledge of the molecular mechanisms that ultimately control the permeation of antibiotics through the outer membrane. This is the innovation gap to be filled for Gram-negative bacteria. This review is focused on the permeation of small molecules through porins, considered the main path for the entry of polar antibiotics into Gram-negative bacteria. A fundamental understanding of how these proteins are able to filter small molecules is a prerequisite to design/optimize antibacterials with improved permeation. The level of sophistication of modern molecular modeling algorithms and the advances in new computer hardware has made the simulation of such complex processes possible at the molecular level. In this work we aim to share our experience and perspectives in the context of a multidisciplinary extended collaboration within the IMI

  7. Permeation of hair dye ingredients, p-phenylenediamine and aminophenol isomers, through protective gloves.

    Science.gov (United States)

    Lee, Hsiao-Shu; Lin, Yu-Wen

    2009-04-01

    Skin irritation and contact allergies are skin disorders common to hairdressers. The predominant oxidative hair dye components, such as p-phenylenediamine (PPD) and aminophenol isomers, can cause contact dermatitis. Use of protective gloves can prevent dermal contact with skin irritants. This study investigates the permeation behaviors of p-aminophenol (PAP), m-aminophenol (MAP), o-aminophenol (OAP) and PPD in single and mixed challenge solutions with disposable natural rubber latex (NRL) gloves, disposable polyvinylchloride (PVC) gloves and neoprene (NP) gloves. The challenge solutions were 4% PPD (w/v), 3% OAP (w/v), 2% PAP (w/v) and 2% MAP (w/v) in ethanol or 12% hydrogen peroxide solutions. The cocktail solutions of the four chemicals were also tested. An American Society for Testing and Materials type permeation cell, ethanol liquid collection and gas chromatography-flame ionization detection of samples taken from the collection medium every 10 min facilitated determination of breakthrough times (BTs), cumulative permeated masses and steady-state permeation rates (SSPRs). Experiments were 4 h long for the NRL and PVC gloves and 8 h for NP gloves. No chemicals tested broke through the NP gloves when exposed for 8 h. In the ethanol solution, PPD and OAP started breaking through the PVC gloves at 40 min. The SSPRs of PVC gloves were higher than those for NRL gloves in all challenge conditions for both single chemicals and mixtures. No tested chemicals in hydrogen peroxide solutions permeated the gloves during the 4-h tests. The chemical composition of the challenge solution was a main effecter of BTs and SSPRs for the NRL glove. For disposable PVC gloves, the main factors of BTs were molecular size [molar volume (MV)] and polarity (logK(ow)), and the primary factors of SSPRs were concentration, MV and logK(ow). In conclusion, disposable NRL gloves and disposable PVC gloves should not be used repeatedly for handling the hair dye products. Hydrogen peroxide did not

  8. Rationalizing the permeation of polar antibiotics into Gram-negative bacteria

    Science.gov (United States)

    Scorciapino, Mariano Andrea; Acosta-Gutierrez, Silvia; Benkerrou, Dehbia; D'Agostino, Tommaso; Malloci, Giuliano; Samanta, Susruta; Bodrenko, Igor; Ceccarelli, Matteo

    2017-03-01

    The increasing level of antibiotic resistance in Gram-negative bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a global challenge for modern medicine. The main reason that Gram-negative bacteria are particularly challenging is the presence of an outer cell-protecting membrane, which is not present in Gram-positive species. Such an asymmetric bilayer is a highly effective barrier for polar molecules. Several protein systems are expressed in the outer membrane to control the internal concentration of both nutrients and noxious species, in particular: (i) water-filled channels that modulate the permeation of polar molecules and ions according to concentration gradients, and (ii) efflux pumps to actively expel toxic compounds. Thus, besides expressing specific enzymes for drugs degradation, Gram-negative bacteria can also resist by modulating the influx and efflux of antibiotics, keeping the internal concentration low. However, there are no direct and robust experimental methods capable of measuring the permeability of small molecules, thus severely limiting our knowledge of the molecular mechanisms that ultimately control the permeation of antibiotics through the outer membrane. This is the innovation gap to be filled for Gram-negative bacteria. This review is focused on the permeation of small molecules through porins, considered the main path for the entry of polar antibiotics into Gram-negative bacteria. A fundamental understanding of how these proteins are able to filter small molecules is a prerequisite to design/optimize antibacterials with improved permeation. The level of sophistication of modern molecular modeling algorithms and the advances in new computer hardware has made the simulation of such complex processes possible at the molecular level. In this work we aim to share our experience and perspectives in the context of a multidisciplinary extended collaboration within the IMI

  9. Transdermal delivery of carvedilol containing glycyrrhizin and chitosan as permeation enhancers: biochemical, biophysical, microscopic and pharmacodynamic evaluation.

    Science.gov (United States)

    Sapra, Bharti; Jain, Subheet; Tiwary, A K

    2008-09-01

    The present study was aimed at unveiling the influence of glycyrrhizin and chitosan on rat epidermis and to correlate these effects with percutaneous permeation characteristics of carvedilol. The permeation of carvedilol across excised rat epidermis was significantly higher (p vehicle as compared to propylene glycol:ethanol (7:3) mixture. Epidermis obtained after 12 hr treatment of viable rat skin with a glycyrrhizin-chitosan mixture showed significantly higher (p space, disordered lipid structure and corneocyte detachment as observed in SEM and TEM suggests great potential of glycyrrhizin for use as a percutaneous permeation enhancer.

  10. Influence of adsorbed hydrogen molecules on the hydrogen permeation and recycling

    International Nuclear Information System (INIS)

    Banno, T.

    1987-01-01

    Hydrogen permeation through a thin iron membrane has been measured using a molecular hydrogen gas and/or a weakly ionized rf-discharge as particle sources. Transient and steady state values of the permeation flux φ p were obtained in the regime where the surface penetration of H and the recombinative release of H 2 are rate-determining. φ p is then proportional to the flux density ψ of the particles which impinge on the membrane upstream. The proportionality factors depend on the nature (atomic or molecular) of the incident particles, on temperature (in particular for a molecular driving gas) and on the ratio of the surface recombinative release rate constants (2σk r ) u and (2σk r ) d up- and downstream, respectively. (orig.)

  11. Hydrogen permeation through steel coated with erbium oxide by sol-gel method

    International Nuclear Information System (INIS)

    Yao Zhenyu; Suzuki, Akihiro; Levchuk, Denis; Chikada, Takumi; Tanaka, Teruya; Muroga, Takeo; Terai, Takayuki

    2009-01-01

    Er 2 O 3 coating is formed on austenitic stainless steel 316ss by sol-gel method. The results showed good crystallization of coating by baking in high purity flowing-argon at 973 K, and indicated that a little oxygen in baking atmosphere is necessary to crystallization of coating. The best baking temperature could be thought as 973 K, to get good crystallization of coating and avoid strong oxidation of steel substrate. The deuterium permeation test was performed for coated and bare 316ss, to evaluate the property of Er 2 O 3 sol-gel coating as a potential tritium permeation barrier. In this study, the deuterium permeability of coated 316ss is about 1-2 orders of magnitude lower than that of bare 316ss, and is about 2-3 orders of magnitude than the referred data of bare Eurofer97 and F82H martensitic steel.

  12. Electro-Conductive Membranes for Permeation Enhancement and Fouling Mitigation: A Short Review.

    Science.gov (United States)

    Formoso, Patrizia; Pantuso, Elvira; De Filpo, Giovanni; Nicoletta, Fiore Pasquale

    2017-07-28

    The research on electro-conductive membranes has expanded in recent years. These membranes have strong prospective as key components in next generation water treatment plants because they are engineered in order to enhance their performance in terms of separation, flux, fouling potential, and permselectivity. The present review summarizes recent developments in the preparation of electro-conductive membranes and the mechanisms of their response to external electric voltages in order to obtain an improvement in permeation and mitigation in the fouling growth. In particular, this paper deals with the properties of electro-conductive polymers and the preparation of electro-conductive polymer membranes with a focus on responsive membranes based on polyaniline, polypyrrole and carbon nanotubes. Then, some examples of electro-conductive membranes for permeation enhancement and fouling mitigation by electrostatic repulsion, hydrogen peroxide generation and electrochemical oxidation will be presented.

  13. Deuterium permeation of amorphous alumina coating on 316L prepared by MOCVD

    Science.gov (United States)

    Li, Shuai; He, Di; Liu, Xiaopeng; Wang, Shumao; Jiang, Lijun

    2012-01-01

    The deuterium permeation behavior of the alumina coating on 316L stainless steel prepared by metal organic chemical vapor deposition (MOCVD) was investigated. The alumina coating was also characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscope (SEM). It was found that the as-prepared coating consisted of amorphous alumina. This alumina coating had a dense, crack-free and homogeneous morphology. Although the alumina coating was amorphous, effective suppression of deuterium permeation was demonstrated. The deuterium permeability of the alumina coating was 51-60 times less than that of the 316L stainless steel and 153-335 times less than that of the referred low activation martensitic steels at 860-960 K.

  14. Chronological age affects the permeation of fentanyl through human skin in vitro

    DEFF Research Database (Denmark)

    Holmgaard, R; Benfeldt, E; Sorensen, J A

    2013-01-01

    AIM: To study the influence of chronological age on fentanyl permeation through human skin in vitro using static diffusion cells. Elderly individuals are known to be more sensitive to opioids and obtain higher plasma concentrations following dermal application of fentanyl compared to younger...... individuals. The influence of age - as an isolated pharmacokinetic term - on the absorption of fentanyl has not been previously studied. METHOD: Human skin from 30 female donors was mounted in static diffusion cells, and samples were collected during 48 h. Donors were divided into three age groups: ... and old age groups: 5,922 and 4,050 ng, respectively). Furthermore, the lag time and absorption rate were different between the three groups, with a significantly higher rate in the young participants versus the oldest participants. CONCLUSION: We demonstrate that fentanyl permeates the skin of young...

  15. Study on low level radioactive wastewater treatment by inorganic membrane permeation combined with complexation

    International Nuclear Information System (INIS)

    Li Junfeng; Wang Jianlong; Bai Qinzhong

    2007-01-01

    Inorganic membranes exhibit greater mechanical durability in some operations than polymeric membranes. They do not suffer from the performance degradation that was resulted from compaction of the membrane structure under pressure or ageing. Membrane permeation combined with complexation was tested for radioactive wastes processing purpose. Sodium poly-acrylic acid was selected as the complexing agent, the efficiency of inorganic membrane with cut-off 1kD, 3kD, 8kD assisted by sodium poly-acrylic acid of different molecular weight were compared. The removal efficiencies of nuclides such as strontium, cesium and cobalt by were compared. The flux and retention factors of different membrane system were compared. The impacts of complexation agent concentration on permeate flux retention factors were studied. The long term behaviours of the membrane system were also studied. Diatomite filter was selected as the pretreatment method, and the efficiency of diatomite filter for pretreatment was investigated also. (author)

  16. Characterization and In Vitro Skin Permeation of Meloxicam-Loaded Liposomes versus Transfersomes

    Directory of Open Access Journals (Sweden)

    Sureewan Duangjit

    2011-01-01

    Full Text Available The goal of this study was to develop and evaluate the potential use of liposome and transfersome vesicles in the transdermal drug delivery of meloxicam (MX. MX-loaded vesicles were prepared and evaluated for particle size, zeta potential, entrapment efficiency (%EE, loading efficiency, stability, and in vitro skin permeation. The vesicles were spherical in structure, 90 to 140 nm in size, and negatively charged (−23 to −43 mV. The %EE of MX in the vesicles ranged from 40 to 70%. Transfersomes provided a significantly higher skin permeation of MX compared to liposomes. Fourier Transform Infrared Spectroscopy (FT-IR and Differential Scanning Calorimetry (DSC analysis indicated that the application of transfersomes significantly disrupted the stratum corneum lipid. Our research suggests that MX-loaded transfersomes can be potentially used as a transdermal drug delivery system.

  17. Standard practice for evaluation of hydrogen uptake, permeation, and transport in metals by an electrochemical technique

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1997-01-01

    1.1 This practice gives a procedure for the evaluation of hydrogen uptake, permeation, and transport in metals using an electrochemical technique which was developed by Devanathan and Stachurski. While this practice is primarily intended for laboratory use, such measurements have been conducted in field or plant applications. Therefore, with proper adaptations, this practice can also be applied to such situations. 1.2 This practice describes calculation of an effective diffusivity of hydrogen atoms in a metal and for distinguishing reversible and irreversible trapping. 1.3 This practice specifies the method for evaluating hydrogen uptake in metals based on the steady-state hydrogen flux. 1.4 This practice gives guidance on preparation of specimens, control and monitoring of the environmental variables, test procedures, and possible analyses of results. 1.5 This practice can be applied in principle to all metals and alloys which have a high solubility for hydrogen, and for which the hydrogen permeation is ...

  18. Absence of molecular deuterium dissociation during room-temperature permeation into polystyrene ICF target shells

    International Nuclear Information System (INIS)

    Honig, A.; Alexander, N.; Fan, Q.; Gram, R.; Kim, H.

    1991-01-01

    Polystyrene microshells filled with deuterium and tritium gas are important target shells for inertially confined fusion (ICF) and are particularly promising for target containing spin-polarized hydrogens fuels. A currently active approach to the latter uses polarized D in HD, in a method which requires preservation of the high purity of the initially prepared HD (very low specified H 2 and D 2 concentrations). This would not be possible if dissociation should occur during permeation into the target shells. We have thus tested polystyrene shells using a novel method which employs very pure polystyrene shells using a novel method which employs very pure ortho-D 2 as the test gas. An upper limit of 6 x 10 -4 was deduced for the dissociation of D 2 upon room temperature permeation through an approximately 8 um wall of polystyrene, clearing the way for use of polystyrene target shells for ICF fusion experiments with spin-polarized hydrogens fuels. 19 refs., 1 fig

  19. Effect of Different Skin Penetration Promoters in Halobetasol Propionate Permeation and Retention in Human Skin

    Directory of Open Access Journals (Sweden)

    Paulina Carvajal-Vidal

    2017-11-01

    Full Text Available Halobetasol propionate (HB is a potent synthetic corticosteroid used against inflammatory skin diseases, such as dermatitis, eczema, and psoriasis, among others. The aim of this study is to define how the presence of different skin penetration enhancers (nonane, menthone, limonene, azone, carene, decanol, linoleic acid and cetiol affects the penetration and retention in skin of HB. To determine drug penetration through skin, 5% of each promoter was used in an ex vivo system with human skin on Franz cells. The results showed that the highest permeation occurs in the presence of menthone, followed by nonane. Permeation parameters were determined. The in vivo test was assessed, and the formulation containing HB-menthone presented better anti-inflammatory efficacy. These results are useful to generate a specific treatment according to each patient’s needs, and the inflammatory characteristics of the disease.

  20. The permeation of hydrogen in a steel at elevated temperature by an electrochemical method

    International Nuclear Information System (INIS)

    Tsubakino, H.; Ando, A.; Yamakawa, K.

    1984-01-01

    An electrochemical permeation method has been widely used to study the transport characteristics of hydrogen in metals, i.e., the content, diffusivity and permeability. This electrochemical measurement technique has the following remarkable features: a good detection limit for the measurement of hydrogen content, a simpler measuring apparatus, suitability for successive measurement of the transport characteristics, and flexibility in variation of experimental conditions. However this method has been restricted to temperatures below 373 K because an aqueous solution has been used as an electrode. In this study, an electrochemical permeation method using molten salts at elevated temperatures (673-773 K) in the range of practical interest for hydrogen attack in steel is presented. The introduction of hydrogen by use of molten salts has been reported but it has been performed at 423473 K and at 553 K

  1. Electro-Conductive Membranes for Permeation Enhancement and Fouling Mitigation: A Short Review

    Directory of Open Access Journals (Sweden)

    Patrizia Formoso

    2017-07-01

    Full Text Available The research on electro-conductive membranes has expanded in recent years. These membranes have strong prospective as key components in next generation water treatment plants because they are engineered in order to enhance their performance in terms of separation, flux, fouling potential, and permselectivity. The present review summarizes recent developments in the preparation of electro-conductive membranes and the mechanisms of their response to external electric voltages in order to obtain an improvement in permeation and mitigation in the fouling growth. In particular, this paper deals with the properties of electro-conductive polymers and the preparation of electro-conductive polymer membranes with a focus on responsive membranes based on polyaniline, polypyrrole and carbon nanotubes. Then, some examples of electro-conductive membranes for permeation enhancement and fouling mitigation by electrostatic repulsion, hydrogen peroxide generation and electrochemical oxidation will be presented.

  2. Characterization of Thin Film Polymers Through Dynamic Mechanical Analysis and Permeation

    Science.gov (United States)

    Herring, Helen

    2003-01-01

    Thin polymer films are being considered, as candidate materials to augment the permeation resistance of cryogenic hydrogen fuel tanks such as would be required for future reusable launch vehicles. To evaluate performance of candidate films after environmental exposure, an experimental study was performed to measure the thermal/mechanical and permeation performance of six, commercial-grade materials. Dynamic storage modulus, as measured by Dynamic Mechanical Analysis, was found over a range of temperatures. Permeability, as measured by helium gas diffusion, was found at room temperature. Test data was correlated with respect to film type and pre-test exposure to moisture, elevated temperature, and cryogenic temperature. Results indicated that the six films were comparable in performance and their resistance to environmental degradation.

  3. Contaminant Permeation in the Ionomer-Membrane Water Processor (IWP) System

    Science.gov (United States)

    Kelsey, Laura K.; Finger, Barry W.; Pasadilla, Patrick; Perry, Jay

    2016-01-01

    The Ionomer-membrane Water Processor (IWP) is a patented membrane-distillation based urine brine water recovery system. The unique properties of the IWP membrane pair limit contaminant permeation from the brine to the recovered water and purge gas. A paper study was conducted to predict volatile trace contaminant permeation in the IWP system. Testing of a large-scale IWP Engineering Development Unit (EDU) with urine brine pretreated with the International Space Station (ISS) pretreatment formulation was then conducted to collect air and water samples for quality analysis. Distillate water quality and purge air GC-MS results are presented and compared to predictions, along with implications for the IWP brine processing system.

  4. Protein permeation through polymer membranes for hybrid-type artificial pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Burczak, K; Fujisato, Toshiya; Ikada, Yoshito [Kyoto Univ. (Japan); Hatada, Motoyoshi

    1991-05-01

    Hydrogel membranes were prepared by radiation crosslinking of poly (vinyl alcohol) (PVA) in aqueous solutions. Effects of PVA concentration, PVA molecular weight, and radiation dose on the permeation of insulin and immunoglobulin through the membranes were investigated. Glucose permeation was also studied. The crosslinking density affected the size of macromolecular mesh of hydrogel network as well as the water content of membrane responsible for the diffusion of the solutes. The diffusion coefficient linearly increased for all the solutes with the increasing water content in PVA hydrogels, indicating that diffusion occurs primarily through the water hydrating the polymer network. The increase in crosslinking density of hydrogels by changing PVA molecular weight brought about the decrease in mesh size of the hydrogels, which, in turn, had an influence on the diffusion of immunoglobulin, but not of insulin and glucose. (author).

  5. A description of an ultra high vacuum device for permeation measurements

    International Nuclear Information System (INIS)

    Gautsch, O.; Hodapp, G.

    1984-01-01

    The permeability of deuterium through austenitic stainless steel membranes is determined by means of an UHV-apparatus as a function of temperature, membrane thickness, and deuterium upstream driving pressure. The upstream side of the membrane is in contact with the liquid alloy of the eutectic Pb 83 Li 17 in order to represent the situation of a tritium breeding blanket of a fusion reactor. By means of the experimental results the amounts of tritium which permeate across the walls of the cooling tubes into the coolant will be determined. The purpose of this work is to describe the apparatus and the methods used for the determination of permeabilities. Also some preliminary results of permeation flux measurements are given

  6. Quantum Dots for Cancer Research: Current Status, Remaining Issues, and Future Perspectives

    International Nuclear Information System (INIS)

    Fang, Min; Peng, Chun-wei; Pang, Dai-Wen; Li, Yan

    2012-01-01

    Cancer is a major threat to public health in the 21st century because it is one of the leading causes of death worldwide. The mechanisms of carcinogenesis, cancer invasion, and metastasis remain unclear. Thus, the development of a novel approach for cancer detection is urgent, and real-time monitoring is crucial in revealing its underlying biological mechanisms. With the optical and chemical advantages of quantum dots (QDs), QD-based nanotechnology is helpful in constructing a biomedical imaging platform for cancer behavior study. This review mainly focuses on the application of QD-based nanotechnology in cancer cell imaging and tumor microenvironment studies both in vivo and in vitro, as well as the remaining issues and future perspectives

  7. Permeation enhancing polymers in oral delivery of hydrophilic macromolecules: thiomer/GSH systems.

    Science.gov (United States)

    Bernkop-Schnürch, A; Kast, C E; Guggi, D

    2003-12-05

    Thiolated polymers (= thiomers) in combination with reduced glutathione (GSH) were shown to improve the uptake of hydrophilic macromolecules from the GI tract. The mechanism responsible for this permeation enhancing effect seems to be based on the thiol groups of the polymer. These groups inhibit protein tyrosine phosphatase, being involved in the closing process of tight junctions, via a GSH-mediated mechanism. The strong permeation enhancing effect of various thiomer/GSH systems such as poly(acrylic acid)-cysteine/GSH or chitosan-4-thio-butylamidine (chitosan-TBA)/GSH could be shown via permeation studies on freshly excised intestinal mucosa in Ussing-type chambers. Furthermore, the efficacy of the system was also shown in vivo. By utilizing poly(acrylic acid)-cysteine/GSH as carrier matrix, an absolute oral bioavailability for low molecular weight heparin of 19.9 +/- 9.3% and a pharmacological efficacy--calculated on the basis of the areas under the reduction in serum glucose levels of the oral formulation versus subcutaneous (s.c.) injection-for orally given insulin of 7% could be achieved. The incorporation of salmon calcitonin in chitosan-TBA/GSH led on the other hand to a pharmacological efficacy based on the areas under the reduction in plasma calcium levels of the oral thiomer formulation versus intravenous (i.v.) injection of 1.3%. Because of this high efficacy (i), the possibility to combine thiomer/GSH systems with additional low molecular weight permeation enhancers acting in other ways (ii) and minimal toxicological risks as these polymers are not absorbed from the GI tract (iii), thiolated polymers represent a promising novel tool for the oral administration of hydrophilic macromolecules.

  8. Permeation Studies of CW Agents with Fabric Treated with 8-Hydroxyquinoline

    Science.gov (United States)

    2017-12-01

    Jeffery R. Owens AIR FORCE CIVIL ENGINEER CENTER AFCEC/CXAE, Tyndall AFB, FL 32403-5320 December 2017 Approved for public release: distribution...P.O. Box 68, Gunpowder, MD 21010-0068 Universal Technology Corp.; 139 Barnes Drive Suite 2 Tyndall AFB, FL 32404-5325 Air Force Civil Engineer ...moisture transport. The garment prevents exposure to outside chemical weapons agents (CWAs) by reacting or reducing permeation of the CWA. By

  9. Development of Fe-AI CVD coatings as tritium permeation barrier

    International Nuclear Information System (INIS)

    Chabrol, C.; Schuster, F.; Le Marois, G.; Serra, E.

    1998-01-01

    A specific method of pack-cementation has been developed in order to perform a CVD deposition of Fe-Al alloys on a martensitic steel at a temperature which respects its mechanical properties ( 2 Al 5 intermetallic phases thanks to a low pressure deposition and using a special cement containing Fe and Al. These coatings coated with an Al 2 O 3 top layer drastically reduce the permeation rate of deuterium with regards to the uncoated substrate. (authors)

  10. Performance Tests of a Permeation Sensor for Test Blanket Modules Using Liquid Metal

    International Nuclear Information System (INIS)

    Choi, B. G.; Lee, D. W.; Lee, E. H.; Yoon, J. S.; Kim, S. K.; Shin, K. I.; Jin, H. G.

    2013-01-01

    The tritium extraction from a breeder is one of the key technologies and its methods have been investigated. For developing the tritium extraction methods and evaluating the amount of tritium in the system, a reliable and correct sensor is required to measure the hydrogen concentration in liquid metal breeder. There are several researches for developing the sensors in the ITER participants and especially, EU has developed the permeation sensors trying to selecting materials with low Serviette's constant (solubility) and high hydrogen diffusivity coefficient. However, EU's response time is still too long time about tens of minutes to measure the tritium concentration in the online system. We have been performing the preliminary tests with designed and fabricated sensors to solve the late response of sensor. However, we could not continue the tests because of the membrane's oxidation (pure Fe) and the difficulty of welding nonferrous metals. In present study, a permeation sensor made of vacuum flanges with a porous plate inside is proposed not only to eliminate the difficulty of the fabrication but to optimize the performance of sensor. The permeation sensor to measure the hydrogen isotopes in liquid metal breeder has been proposed and evaluated to overcome the limitation of a long response time for various shapes and materials. We found that the previous sensors have limitation; the oxidation problems (pure Fe) and the difficulty in welding (nonferrous metals). Therefore we proposed a permeation sensor with the vacuum flanges filled with porous disks to eliminate the problems. By using the CF flanges, the problem caused by welding is removed. But the permeable response time of sensors took a long time to reach the pressure equivalent

  11. Cascades for natural water enrichment in deuterium and oxygen-18 using membrane permeation

    International Nuclear Information System (INIS)

    Chmielewski, A.G.; Matuszak, A.; Zakrzewska-Trznadel, G.; Van Hook, A.

    1991-01-01

    The enrichment of water in heavy isotopes by permeation through a hydrophobic membrane is described. Simple counter - current cascades are of no practical interest because of their high energy demand. A better solution is to employ a double counter - current cascade re-utilizing part of the heat of condensation. Currently employed methods of natural water enrichment in heavy isotopes are compared to the proposed membrane process. (author). 18 refs, 14 tabs, 21 figs

  12. Resistance of gloves and protective clothing materials to permeation of cytostatic solutions

    OpenAIRE

    Sylwia Krzemińska; Małgorzata Pośniak; Małgorzata Szewczyńska

    2018-01-01

    Objectives The objective of the work was to determine the resistance of selected protective clothing and glove materials to permeation of cytostatics such as docetaxel, fluorouracil, and doxorubicin. Material and Methods The following glove materials were used: natural rubber latex (code A), acrylonitrile-butadiene rubber (code B) and chloroprene rubber (code C). In addition, we tested a layered material composed of a non-woven polyester (PES), a polypropylene (PP) film, ...

  13. Physicochemical Characterization and Skin Permeation of Cationic Transfersomes Containing the Synthetic Peptide PnPP-19.

    Science.gov (United States)

    Almeida, Flavia De Marco; Silva, Carolina Nunes; de Araujo Lopes, Savia Caldeira; Santos, Daniel Moreira; Torres, Fernanda Silva; Cardoso, Felipe Lima; Martinelli, Patricia Massara; da Silva, Elizabeth Ribeiro; de Lima, Maria Elena; Miranda, Lucas Antonio Ferreira; Oliveira, Monica Cristina

    2018-01-08

    PnPP-19 is a 19-amino-acid synthetic peptide previously described as a novel drug for the treatment of erectile dysfunction. The aim of this work was to evaluate the physicochemical properties of cationic transfersomes containing PnPP-19 and the skin permeation of free PnPP-19 and PnPP-19-loaded transfersomes. Three different liposomal preparation methods were evaluated. Cationic transfersomes contained egg phosphatidyl choline: stearylamine (9:1 w/w) and Tween 20 (84.6:15.4 lipid:Tween, w/w). Lipid concentration varied from 20 to 40 mM. We evaluated the entrapment percentage, mean diameter, zeta potential and stability at 4 oC of the formulations. The skin permeation assays were performed with abdominal human skin using Franz diffusion cell with 3 cm2 diffusion area at 32 oC and a fluorescent derivative of the peptide, containing 5-TAMRA, bound to PnPP-19 C-terminal region, where an extra lysine was inserted. Our results showed variable entrapment efficiencies, from 6% to 30%, depending on the preparation method and the lipid concentration used. The reverse phase evaporation method using a total lipid concentration equal to 40 mM led to the best entrapment percentage (30.2 + 4.5%). Free PnPP-19 was able to permeate skin at a rate of 10.8 ng/cm2/h. However, PnPP-19 was specifically hydrolyzed by skin proteases, generating a fragment of 15 amino acid residues. Encapsulated PnPP-19 permeated the skin at a rate of 19.8 ng/cm2/h. The encapsulation of PnPP-19 in cationic transfersomes protected the peptide from degradation, favoring its topical administration. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. Ultrasound in Biomedical Engineering: Ultrasound Microbubble Contrast Agents Promote Transdermal Permeation of Drugs

    OpenAIRE

    Ai-Ho Liao

    2016-01-01

    This report discusses a new development in the use of ultrasound microbubble contrast agents on transdermal drug delivery. The medium surrounding the microbubbles at the optimum concentration from liquid to gel can be modified and it can still achieve the same enhancement for transdermal drug permeation as liquid medium. It was also found that under the same ultrasound power density, microbubbles of larger particle sizes can extend the penetration depths of dye at the phantom surface.

  15. Purification Simulation With Vapor Permeation and Distillation-Adsorption In Bioethanol Plant

    OpenAIRE

    Misri Gozan; Mia Sari Setiawan; Kenny Lischer

    2017-01-01

    High purity of Bioethanol is required in biofuel mixing with gasoline (EXX). In bioethanol production line, the azeotropic property of ethanol-water becomes the barrier for purification process. This study examined two bioethanol separation processes by support of simulation tools, Superpro Designer 9.0 software. Ethanol purity and a low costeconomical process were the major considerations. Purification method of vapor permeation membrane technology was compared with distillation-adsorption m...

  16. Evaluation of the suitability of chromatographic systems to predict human skin permeation of neutral compounds.

    Science.gov (United States)

    Hidalgo-Rodríguez, Marta; Soriano-Meseguer, Sara; Fuguet, Elisabet; Ràfols, Clara; Rosés, Martí

    2013-12-18

    Several chromatographic systems (three systems of high-performance liquid chromatography and two micellar electrokinetic chromatography systems) besides the reference octanol-water partition system are evaluated by a systematic procedure previously proposed in order to know their ability to model human skin permeation. The precision achieved when skin-water permeability coefficients are correlated against chromatographic retention factors is predicted within the framework of the solvation parameter model. It consists in estimating the contribution of error due to the biological and chromatographic data, as well as the error coming from the dissimilarity between the human skin permeation and the chromatographic systems. Both predictions and experimental tests show that all correlations are greatly affected by the considerable uncertainty of the skin permeability data and the error associated to the dissimilarity between the systems. Correlations with much better predictive abilities are achieved when the volume of the solute is used as additional variable, which illustrates the main roles of both lipophilicity and size of the solute to penetrate through the skin. In this way, the considered systems are able to give precise estimations of human skin permeability coefficients. In particular, the HPLC systems with common C18 columns provide the best performances in emulating the permeation of neutral compounds from aqueous solution through the human skin. As a result, a methodology based on easy, fast, and economical HPLC measurements in a common C18 column has been developed. After a validation based on training and test sets, the method has been applied with good results to the estimation of skin permeation of several hormones and pesticides. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Modeling the concentration-dependent permeation modes of the KcsA potassium ion channel.

    Science.gov (United States)

    Nelson, Peter Hugo

    2003-12-01

    The potassium channel from Streptomyces lividans (KcsA) is an integral membrane protein with sequence similarity to all known potassium channels, particularly in the selectivity filter region. A recently proposed model for ion channels containing either n or (n-1) single-file ions in their selectivity filters [P. H. Nelson, J. Chem. Phys. 177, 11396 (2002)] is applied to published KcsA channel K+ permeation data that exhibit a high-affinity process at low concentrations and a low-affinity process at high concentrations [M. LeMasurier et al., J. Gen. Physiol. 118, 303 (2001)]. The kinetic model is shown to provide a reasonable first-order explanation for both the high- and low-concentration permeation modes observed experimentally. The low-concentration mode ([K+]200 mM) has a 200-mV dissociation constant of 1100 mM and a conductance of 500 pS. Based on the permeation model, and x-ray analysis [J. H. Morais-Cabral et al., Nature (London) 414, 37 (2001)], it is suggested that the experimentally observed K+ permeation modes correspond to an n=3 mechanism at high concentrations and an n=2 mechanism at low concentrations. The ratio of the electrical dissociation distances for the high- and low-concentration modes is 3:2, also consistent with the proposed n=3 and n=2 modes. Model predictions for K+ channels that exhibit asymmetric current-voltage (I-V) curves are presented, and further validation of the kinetic model via molecular simulation and experiment is discussed. The qualitatively distinct I-V characteristics exhibited experimentally by Tl+, NH+4, and Rb+ ions at 100 mM concentration can also be explained using the model, but more extensive experimental tests are required for quantitative validation of the model predictions.

  18. Final report for Allied-Signal Aerospace Company, Kansas City Division on protective glove permeation analysis

    International Nuclear Information System (INIS)

    Swearengen, P.M.; Johnson, J.S.; Priante, S.J.

    1990-01-01

    We conducted 25 separate glove fabric permeation studies during this project. The permeations were carried out in the small (1 inch) glass ASTM cell. One other permeation study was carded out with a large (two inch) modified ASTM cell for comparison with the small cell results. We also compared the LLNL procedure from both large and small cells with the standard ASTM test procedure which uses a liquid solution on the breakthrough side of the fabric (the liquid is then sampled on a periodic basis). In all comparisons we observed a close-correlation in breakthrough times between the two procedures and the two cell sizes. In the course of this study, we tested ten different glove materials. These included neoprene (original ASTM round-robin sheet stock, 16 mil thickness), Edmont Sol-Vex (nitrile), Pioneer nitrile, Pioneer Pylox (polyvinyl chloride), North Viton (trademark for fluoroelastomers), North SilverShield (Norfoil, trademark for a flexible metallized laminate), Safety 4 4H (patented plastic laminate), and QRP PolyTuff (polyurethane) 20G-2000 (5 mil), 23G-2300 (1.5 mil), and 25G-2500 (1.5 mil). Three of the glove materials, Viton and Silver Shield (North), and 4H (Safety 4), did not allow any permeation measurable by our system to either 1,2-dichloroethane or 3% diphenylmercury (in 1,2-dichloroethane) for a period greater than six hours. A fourth material, QRP Poly Tuff 2OG-2000, did not allow any measurable penetration of Asilamine (an aromatic diamine) for a time pedod of greater than 4 hours. Breakthrough times and curves were obtained for all other tested materials. Eleven different chemicals were used to challenge the glove materials. These included acetone, Asilamine, 1,2-dichloroethane, dichloromethane, isopropyl alcohol, a mixture of 3% diphenylmercury in 1,2-dichloroethane (w/w), phenol, and lso Verre Stripper, 4,4'-methylenedianil (MDA), 1,3-phenylenediamine (MPDA), and Shell Epon (R) curing agent Z

  19. Tritium permeation evaluation through vertical target of divertor based on recent tritium transport properties

    OpenAIRE

    中村 博文; 西 正孝

    2003-01-01

    Re-evaluation of tritium permeation through vertical target of divertor under the ITER operation condition was carried out using tritium transport properties in the candidate materials such as the diffusion coefficient and the trapping factors in tungsten for armor, and the surface recombination coefficient on copper for the heat sink obtained by authors' recent investigation (authors' data), which simulated the plasma-facing conditions of ITER. Evaluation with the data set of previous evalua...

  20. Effect of chemical permeation enhancers on stratum corneum barrier lipid organizational structure and interferon alpha permeability.

    Science.gov (United States)

    Moghadam, Shadi H; Saliaj, Evi; Wettig, Shawn D; Dong, Chilbert; Ivanova, Marina V; Huzil, J Torin; Foldvari, Marianna

    2013-06-03

    The outermost layer of the skin, known as the stratum corneum (SC), is composed of dead corneocytes embedded in an intercellular lipid matrix consisting of ceramides, free fatty acids, and cholesterol. The high level of organization within this matrix protects the body by limiting the permeation of most compounds through the skin. While essential for its protective functions, the SC poses a significant barrier for the delivery of topically applied pharmaceutical agents. Chemical permeation enhancers (CPEs) can increase delivery of small drug compounds into the skin by interacting with the intercellular lipids through physical processes including extraction, fluidization, increased disorder, and phase separation. However, it is not clear whether these same mechanisms are involved in delivery of biotherapeutic macromolecules, such as proteins. Here we describe the effect of three categories of CPEs {solvents [ethanol, propylene glycol, diethylene glycol monoethyl ether (transcutol), oleic acid], terpenes [menthol, nerol, camphor, methyl salicylate], and surfactants [Tween 80, SDS, benzalkonium chloride, polyoxyl 40 hydrogenated castor oil (Cremophor RH40), didecyldimethylammonium bromide (DDAB), didecyltrimethylammonium bromide (DTAB)]} on the lipid organizational structure of human SC as determined by X-ray scattering studies. Small- and wide-angle X-ray scattering studies were conducted to correlate the degree of structural changes and hydrocarbon chain packing in SC lipids caused by these various classes of CPEs to the extent of permeation of interferon alpha-2b (IFNα), a 19 kDa protein drug, into human skin. With the exception of solvents, propylene glycol and ethanol, all classes of CPEs caused increased disordering of lamellar and lateral packing of lipids. We observed that the highest degree of SC lipid disordering was caused by surfactants (especially SDS, DDAB, and DTAB) followed by terpenes, such as nerol. Interestingly, in vitro skin permeation studies

  1. Synthesis of conjugated chitosan and its effect on drug permeation from transdermal patches.

    Science.gov (United States)

    Satheeshababu, B K; Shivakumar, K L

    2013-03-01

    The aim of this study was to synthesis the conjugated chitosan by covalent attachment of thiol moieties to the cationic polymer, mediated by a carbodiimide to improve permeation properties of chitosan. Thioglycolic acid was covalently attached to chitosan by the formation of amide bonds between the primary amino groups of the polymer and the carboxylic acid groups of thioglycolic acid. Hence, these polymers are called as thiomers or thiolated polymers. Conjugation of chitosan was confirmed by Fourier transform-infrared and differential scanning calorimetric analysis. Matrix type transdermal patches of carvedilol were prepared using the different proportions of chitosan and chitosan-thioglycolic acid conjugates (2:0, 1.7:0.3, 1.4:0.6, 1:1, 0.6:1.4 and 0.3:1.7) by solvent casting technique. Prepared matrix type patches were evaluated for their physicochemical characterization followed by in vitro evaluation. Selected formulations were subjected for their ex vivo studies on Wistar albino rat skin and human cadaver skin using the modified Franz diffusion cell. As the proportion of conjugated chitosan increased, the transdermal patches showed increased drug permeation. The mechanism of drug release was found to be nonFickian profiles. The present study concludes that the transdermal patches of carvedilol using conjugated chitosan with different proportions of chitosan were successfully developed to provide improved drug permeation. The transdermal patches can be a good approach to improve drug bioavailability by bypassing the extensive hepatic first-pass metabolism of the drug.

  2. Determination of factor of hydrogen permeation reduction (PRF) for different protective coatings over vanadium

    International Nuclear Information System (INIS)

    Afanasyev, S.; Kulsartov, T.; Shestakov, V.; Chikhray, Y.; Smith, D.

    2002-01-01

    Selection of structural materials for liquid-metal system as well as for another system and constructions of nuclear energy plants must be carried out and based on specified demands depending on conditions of these materials functioning. Specific demand is its compatibility with liquid metals. Design of reactors with liquid-metal coolant (Li, PbLi 17 ) which reproduces tritium arise additional demand to structural materials. This demand is a creation of structural material or protective barrier with minimum acceptable value of tritium permeation through itself or with maximum permeation reduction factor (PRF). Vanadium and vanadium alloys are supposed to be use as a blanket structural material in such nuclear energy plants. Worked out at first stage of studies vanadium coatings should have stability of its characteristics at temperature 800 deg. C under influence of hydrogen. Given work shows the experimental results on testing of protective coatings over vanadium: glass-ceramic coating and CaO-base coating. PRF for every coating and its changes depending on thermo-capacity of vanadium sample with coating was determined by method of hydrogen permeation. The results of experiments would be used at the development of cooling loops of reactor core protection with liquid-metal coolant

  3. Buccal delivery of thiocolchicoside: in vitro and in vivo permeation studies.

    Science.gov (United States)

    Artusi, M; Santi, P; Colombo, P; Junginger, H E

    2003-01-02

    Thiocolchicoside, a muscle-relaxant agent, is administered by the oral, intra-muscular and topical route. After oral administration the extent of bioavailability compared with intra-muscular administration is low, due to a first pass effect. In this paper, the delivery of thiocolchicoside through oral mucosa is studied to improve the bioavailability. Thiocolchicoside in vitro permeation through porcine oral mucosa and in vivo buccal transport in humans were investigated. Two dosage forms, a bioadhesive disc and a fast dissolving disc for buccal and sublingual administration of thiocolchicoside, respectively, were designed. The in vitro permeation of thiocolchicoside through porcine buccal mucosa from these dosage forms was evaluated and compared with in vivo absorption. Results from in vitro studies demonstrated that thiocolchicoside is quite permeable across porcine buccal mucosa and that permeation enhancers, such as sodium taurocholate and sodium taurodeoxycholate, were not able to increase its flux. The in vivo thiocolchicoside absorption experiments, in which the drug loss from oral cavity was measured, indicated that both formulations could be useful for therapeutic application. The fast dissolving (sublingual) form resulted in a quick uptake of 0.5 mg of thiocolchicoside within 15 min whereas with the adhesive buccal form the same dose can be absorbed over an extended period of time.

  4. A study of hydrogen permeation in aluminum alloy treated by various oxidation processes

    International Nuclear Information System (INIS)

    Song Wenhai; Long Bin

    1997-01-01

    A set of oxide coatings was formed on the surface of an Al alloy (wt%: Fe, 0.24; Si, 1.16; Cu, 0.05-0.2; Zn, 0.1; Al, residual) by means of various oxidation processes. The hydrogen permeability through the aluminum alloy and its coating materials was determined by a vapor phase permeation technique at temperatures ranging from 400 to 500 C using high-purity H 2 (99.9999%) gas with an upstream hydrogen pressure of 10 4 -10 5 Pa. The experimental results show that the hydrogen permeability through aluminum oxide coating is 100-2000 times lower than that through the aluminum alloy substrate. This means that the aluminum oxide is a significant hydrogen permeation barrier. A high hydrogen permeation resistance was observed in an oxide layer prefilmed in 200 C water, while an anodized aluminum oxide film had a less obstructive effect, possibly caused by the porous structure of the anodic oxide. The hydrogen permeability through films of aluminum oxide was not a simple function of the aluminum-oxide phase configuration. (orig.)

  5. d-Tagatose production by permeabilized and immobilized Lactobacillus plantarum using whey permeate.

    Science.gov (United States)

    Jayamuthunagai, J; Srisowmeya, G; Chakravarthy, M; Gautam, P

    2017-07-01

    The aim of the work is to produce d-Tagatose by direct addition of alginate immobilized Lactobacillus plantarum cells to lactose hydrolysed whey permeate. The cells were untreated and immobilized (UIC), permeabilized and immobilized (PIC) and the relative activities were compared with purified l-arabinose isomerase (l-AI) for d-galactose isomerization. Successive lactose hydrolysis by β-galactosidase from Escherichia coli and d-galactose isomerization using l-AI from Lactobacillus plantarum was performed to investigate the in vivo production of d-tagatose in whey permeate. In whey permeate, maximum conversion of 38% and 33% (w/w) d-galactose isomerization by PIC and UIC has been obtained. 162mg/g and 141mg/g of d-tagatose production was recorded in a 48h reaction time at 50°C, pH 7.0 with 5mM Mn 2+ ion concentration in the initial substrate mixture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Vapor permeation-stepwise injection simultaneous determination of methanol and ethanol in biodiesel with voltammetric detection.

    Science.gov (United States)

    Shishov, Andrey; Penkova, Anastasia; Zabrodin, Andrey; Nikolaev, Konstantin; Dmitrenko, Maria; Ermakov, Sergey; Bulatov, Andrey

    2016-02-01

    A novel vapor permeation-stepwise injection (VP-SWI) method for the determination of methanol and ethanol in biodiesel samples is discussed. In the current study, stepwise injection analysis was successfully combined with voltammetric detection and vapor permeation. This method is based on the separation of methanol and ethanol from a sample using a vapor permeation module (VPM) with a selective polymer membrane based on poly(phenylene isophtalamide) (PA) containing high amounts of a residual solvent. After the evaporation into the headspace of the VPM, methanol and ethanol were transported, by gas bubbling, through a PA membrane to a mixing chamber equipped with a voltammetric detector. Ethanol was selectively detected at +0.19 V, and both compounds were detected at +1.20 V. Current subtractions (using a correction factor) were used for the selective determination of methanol. A linear range between 0.05 and 0.5% (m/m) was established for each analyte. The limits of detection were estimated at 0.02% (m/m) for ethanol and methanol. The sample throughput was 5 samples h(-1). The method was successfully applied to the analysis of biodiesel samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Bias-Exchange Metadynamics Simulation of Membrane Permeation of 20 Amino Acids.

    Science.gov (United States)

    Cao, Zanxia; Bian, Yunqiang; Hu, Guodong; Zhao, Liling; Kong, Zhenzhen; Yang, Yuedong; Wang, Jihua; Zhou, Yaoqi

    2018-03-16

    Thermodynamics of the permeation of amino acids from water to lipid bilayers is an important first step for understanding the mechanism of cell-permeating peptides and the thermodynamics of membrane protein structure and stability. In this work, we employed bias-exchange metadynamics simulations to simulate the membrane permeation of all 20 amino acids from water to the center of a dipalmitoylphosphatidylcholine (DPPC) membrane (consists of 256 lipids) by using both directional and torsion angles for conformational sampling. The overall accuracy for the free energy profiles obtained is supported by significant correlation coefficients (correlation coefficient at 0.5-0.6) between our results and previous experimental or computational studies. The free energy profiles indicated that (1) polar amino acids have larger free energy barriers than nonpolar amino acids; (2) negatively charged amino acids are the most difficult to enter into the membrane; and (3) conformational transitions for many amino acids during membrane crossing is the key for reduced free energy barriers. These results represent the first set of simulated free energy profiles of membrane crossing for all 20 amino acids.

  8. Study of the cathodic depolarization theory with hydrogen permeation and the bacteria Desulfovibrio desulfuricans

    International Nuclear Information System (INIS)

    Romero, M. F. de; Duque, Z.; Rinco, O. T. de; Perez, O.; Araujo, I.

    2003-01-01

    A Desulfovibrio desulfuricans ssp. desulfuricans (SRB) was used to study the permeation of hydrogen, using a Devanatan and Stachurski cell and a palladium sheet. The aim was to evaluate cathodic depolarization as a Sulfate-Reducing Bacteria action mechanisms in Microbiologically Induced Corrosion. The permeation tests were run with and without cathodic polarization, using a sterile deaerated culture medium inoculated with 10% SRB concentrated at 10''8 cell/ml. the results indicate bacterial growth in the order of 10''9-10''10 cel/ml after 18 h both in the polarized and non-polarized, tests, indicating that SRB developed regardless of the surface polarized as a source of H''0, generating H 2 S as a product of the anaerobic respiration. It was also determined that, without cathodic polarization, the conditions are not enough to reduce the H* generated by the H 2 S dissociation (pd is not susceptible to corrosion at this condition). On the other hand, cathodic polarization increased the permeation current, which was associated with the maximum enzymatic activity phase of the bacteria. (Author) 8 refs

  9. Deuterium gas-driven permeation and subsequent retention in rolled tungsten foils

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Feng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhou, Haishan [Department of Fusion Science, The Graduate University for Advanced Studies, Toki 509-5292 (Japan); Li, Xiao-Chun [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Xu, Yuping; An, Zhongqing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026 (China); Mao, Hongmin; Xing, Wenjing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Hou, Qing [Key Laboratory for Radiation Physics and Technology, Sichuan University, Chengdu 610061 (China); Luo, Guang-Nan, E-mail: gnluo@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026 (China)

    2014-12-15

    Experiments concerning deuterium gas-driven permeation through rolled tungsten foils in the temperature range of 850–950 K and subsequent deuterium retention have been performed. The steady state permeation flux of deuterium is proportional to the square root of the driving pressure. The permeability of deuterium is in an order of 10{sup −14} mol m{sup −1} s{sup −1} Pa{sup −1/2} in this temperature range and the activation energy for permeation is 1.21 eV. Measurements of diffusivity are significantly affected by the driving pressure, which can be well explained by a saturable-trap model. Thermal desorption spectra of samples feature a single deuterium release peak at about 873 K. TMAP 4 modeling of this peak gives a detrapping energy of 1.70 eV, which fits the dissociation enthalpy of deuterium desorbing from the inner wall of vacancy clusters or pores in tungsten.

  10. Hydrogen permeation in FeCrAl alloys for LWR cladding application

    Science.gov (United States)

    Hu, Xunxiang; Terrani, Kurt A.; Wirth, Brian D.; Snead, Lance L.

    2015-06-01

    FeCrAl, an advanced oxidation-resistant iron-based alloy class, is a highly prevalent candidate as an accident-tolerant fuel cladding material. Compared with traditional zirconium alloy fuel cladding, increased tritium permeation through FeCrAl fuel cladding to the primary coolant is expected, raising potential safety concerns. In this study, the hydrogen permeability of several FeCrAl alloys was obtained using a static permeation test station, which was calibrated and validated using 304 stainless steel. The high hydrogen permeability of FeCrAl alloys leads to concerns with respect to potentially significant tritium release when used for fuel cladding in LWRs. The total tritium inventory inside the primary coolant of a light water reactor was quantified by applying a 1-dimensional steady state tritium diffusion model to demonstrate the dependence of tritium inventory on fuel cladding type. Furthermore, potential mitigation strategies for tritium release from FeCrAl fuel cladding were discussed and indicate the potential for application of an alumina layer on the inner clad surface to serve as a tritium barrier. More effort is required to develop a robust, economical mitigation strategy for tritium permeation in reactors using FeCrAl clad fuel assemblies.

  11. Bias-Exchange Metadynamics Simulation of Membrane Permeation of 20 Amino Acids

    Directory of Open Access Journals (Sweden)

    Zanxia Cao

    2018-03-01

    Full Text Available Thermodynamics of the permeation of amino acids from water to lipid bilayers is an important first step for understanding the mechanism of cell-permeating peptides and the thermodynamics of membrane protein structure and stability. In this work, we employed bias-exchange metadynamics simulations to simulate the membrane permeation of all 20 amino acids from water to the center of a dipalmitoylphosphatidylcholine (DPPC membrane (consists of 256 lipids by using both directional and torsion angles for conformational sampling. The overall accuracy for the free energy profiles obtained is supported by significant correlation coefficients (correlation coefficient at 0.5–0.6 between our results and previous experimental or computational studies. The free energy profiles indicated that (1 polar amino acids have larger free energy barriers than nonpolar amino acids; (2 negatively charged amino acids are the most difficult to enter into the membrane; and (3 conformational transitions for many amino acids during membrane crossing is the key for reduced free energy barriers. These results represent the first set of simulated free energy profiles of membrane crossing for all 20 amino acids.

  12. Effect of emulsification on the skin permeation and UV protection of catechin.

    Science.gov (United States)

    Yoshino, Sachie; Mitoma, Tomoaki; Tsuruta, Keiko; Todo, Hiroaki; Sugibayashi, Kenji

    2014-06-01

    An anti-aging effect may be obtained by skin application of tea catechins (Camellia sinensis) since they have high ultraviolet (UV)-protection activity. In this study, the skin permeation of catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECg) and epigallocatechin gallate (EGCg) was determined and compared, and the effect of emulsification on the skin permeation of C was measured. The UV-protective effect of C was also determined. The in vitro skin permeability of each catechin derivative was determined using side-by-side diffusion of cells. The UV-protective effect of C was determined by applying different concentrations of C to the solution or emulsion on a three-dimensional cultured human skin model or normal human epidermal keratinocytes with UV-irradiation. ECg and EGCg with gallate groups showed lower skin permeability than C, EC and EGC without gallate groups, suggesting that the skin permeability of catechin derivatives may be dependent on the existence of a gallate group. Interestingly, the skin permeation of C was increased by an o/w emulsification. In addition, the C emulsion showed a significantly higher UV-protective effect by C than that with its aqueous solution. These results suggest that the o/w emulsion of catechin derivatives is probably useful as a cosmetic formulation with anti-aging efficacy.

  13. Analysis of skin permeation-enhancing mechanism of iontophoresis using hydrodynamic pore theory.

    Science.gov (United States)

    Manabe, E; Numajiri, S; Sugibayashi, K; Morimoto, Y

    2000-05-15

    The effects of constant DC iontophoresis (0-1.5 mA/0.966 cm(2)) on the permeation of three hydrophilic compounds, antipyrine (ANP, M.W. 188.23), sucrose (SR, M.W. 342.30) and 1-kestose (KT, M.W. 506.73), through excised hairless rat skin were evaluated using hydrodynamic pore theory. The electro-osmotic flow caused by iontophoresis was measured using deuterium oxide (D(2)O). The penetration-enhancing mechanism of iontophoresis was found to increase solvent flow through electro-osmosis and pore enlargement and/or new pore production in the skin barrier, together with enhancement of electrochemical potential difference across the skin. These effects were closely related to the strength of the current applied. The electro-osmotic flow of D(2)O (J(D(2)O)) greatly enhanced the skin permeation clearance of all hydrophilic penetrants (CL(drug)). Pore production was classified into reversible and irreversible processes, which resulted from lower (0-0.5 mA/0.966 cm(2)) and higher (0.5-1. 5 mA/0.966 cm(2)) currents, respectively. Thus, the enhancing effects of iontophoresis on skin permeation of nonionic hydrophilic compounds can be explained by increase in pore size and higher solvent flow.

  14. Water permeation through the internal water pathway in activated GPCR rhodopsin.

    Directory of Open Access Journals (Sweden)

    Katsufumi Tomobe

    Full Text Available Rhodopsin is a light-driven G-protein-coupled receptor that mediates signal transduction in eyes. Internal water molecules mediate activation of the receptor in a rhodopsin cascade reaction and contribute to conformational stability of the receptor. However, it remains unclear how internal water molecules exchange between the bulk and protein inside, in particular through a putative solvent pore on the cytoplasmic. Using all-atom molecular dynamics simulations, we identified the solvent pore on cytoplasmic side in both the Meta II state and the Opsin. On the other hand, the solvent pore does not exist in the dark-adapted rhodopsin. We revealed two characteristic narrow regions located within the solvent pore in the Meta II state. The narrow regions distinguish bulk and the internal hydration sites, one of which is adjacent to the conserved structural motif "NPxxY". Water molecules in the solvent pore diffuse by pushing or sometimes jumping a preceding water molecule due to the geometry of the solvent pore. These findings revealed a total water flux between the bulk and the protein inside in the Meta II state, and suggested that these pathways provide water molecules to the crucial sites of the activated rhodopsin.

  15. Dual-directional regulation of drug permeating amount by combining the technique of ion-pair complexation with chemical enhancers for the synchronous permeation of indapamide and bisoprolol in their compound patch through rabbit skin.

    Science.gov (United States)

    Song, Wenting; Cun, Dongmei; Quan, Peng; Liu, Nannan; Chen, Yang; Cui, Hongxia; Xiang, Rongwu; Fang, Liang

    2015-04-01

    To achieve the synchronous skin permeation of indapamide (IND) and bisoprolol (BSP) in their compound patch, the techniques of ion-pair complexation and chemical enhancers were combined to dual-directionally regulate drug permeating amounts. Ion-pair complexes of BSP and various organic acids were formed by the technique of ion-pair complexation. Among the complexes formed, bisoprolol tartrate (BSP.T) down-regulated the permeating amount of BSP to the same extent as that of IND. Then, to simultaneously up-regulate the amounts of the two drugs, an enhancer combination of 15.8% Span80 (SP), 6.0% Azone (AZ) and 2.2% N-methyl pyrrolidone (NMP) was obtained by central composite design and exhibited an outstanding and simultaneous enhancement on IND and BSP with enhancing ratio (ER) of 4.52 and 3.49, respectively. The effect of the dual-directional regulation was evaluated by in vitro permeation experiments and in vivo pharmacokinetic studies. For IND and BSP, their observed permeation profiles were comparable and their MAT (mean absorption time) showed no significant difference, which both demonstrated these two drugs achieved the synchronous skin permeation in their compound patch by the dual-directional regulation strategy of combining the technique of ion-pair complexation with chemical enhancers. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Physical Aging, Plasticization and Their Effects on Gas Permeation in “Rigid” Polymers of Intrinsic Microporosity

    KAUST Repository

    Swaidan, Raja; Ghanem, Bader; Litwiller, Eric; Pinnau, Ingo

    2015-01-01

    Long-term physical aging and plasticization, two mobility-based phenomena that are counterintuitive in the context of “rigid” polymers of intrinsic microporosity (PIMs), were evaluated using pure- and mixed-gas permeation data for representative

  17. Effect of hygroscopic materials on water vapor permeation and dehumidification performance of poly(vinyl alcohol) membranes

    KAUST Repository

    Bui, T. D.; Wong, Y.; Thu, K.; Oh, S. J.; Kum Ja, M.; Ng, Kim Choon; Raisul, I.; Chua, K. J.

    2017-01-01

    increased with both added hygroscopic material and absorbed water. Water permeation energy varied from positive to negative with higher hygroscopic content. This observation is attributed to a lower diffusion energy and a relatively constant sorption energy

  18. Experimental Evaluation of Hybrid Distillation-Vapor Permeation Process for Efficient Ethanol Recovery from Ethanol-Water Mixtures

    Science.gov (United States)

    The energy demand of distillation-based systems for ethanol recovery and dehydration can be significant, particularly for dilute solutions [1]. An alternative separation process integrating vapor stripping with a vapor compression step and a vapor permeation membrane separation ...

  19. The ‘ideal selectivity’ vs ‘true selectivity’ for permeation of gas mixture in nanoporous membranes

    Science.gov (United States)

    He, Zhou; Wang, Kean

    2018-03-01

    In this study, we proposed and validated a novel and non-destructive experimental technology for measuring the permeation of binary gas mixture in nanoporous membranes. The traditional time lag rig was modified to examine the permeation characteristics of each gas component as well as that of the binary gas mixtures. The difference in boiling points of each species were explored. Binary gas mixtures of CO2/He were permeated through the nanoporous carbon molecular sieve membrane (CMSM). The results showed that, due to the strong interaction among different molecules and with the porous network of the membrane, the measured perm-selectivity or ‘true selectivity’ of a binary mixture can significantly deviate from the ‘ideal selectivity’ calculated form the permeation flux of each pure species, and this deviation is a complicated function of the molecular properties and operation conditions.

  20. Development of a low tritium partial pressure permeation system for mass transport measurement in lead lithium eutectic

    International Nuclear Information System (INIS)

    Pawelko, R.; Shimada, M.; Katayama, K.; Fukada, S.; Terai, T.

    2014-01-01

    A new experimental system designed to investigate tritium mass transfer properties in materials important to fusion technology is operational at the Safety and Tritium Applied Research (STAR) facility located at the Idaho National Laboratory (INL). The tritium permeation measurement system was developed as part of the Japan/US TITAN collaboration to investigate tritium mass transfer properties in liquid lead lithium eutectic (LLE) alloy. The system is similar to a hydrogen/deuterium permeation measurement system developed at Kyushu University and also incorporates lessons learned from previous tritium permeation experiments conducted at the STAR facility. This paper describes the experimental system that is configured specifically to measure tritium mass transfer properties at low tritium partial pressures. We present preliminary tritium permeation results for α-Fe and α-Fe/LLE samples at 600degC and at tritium partial pressures between 1.0E-3 and 2.4 Pain helium. The preliminary results are compared with literature data. (author)

  1. Effect of feed flow pattern on the distribution of permeate fluxes in desalination by direct contact membrane distillation

    KAUST Repository

    Soukane, Sofiane

    2017-05-31

    The current study aims to highlight the effect of flow pattern on the variations of permeate fluxes over the membrane surface during desalination in a direct contact membrane distillation (DCMD) flat module. To do so, a three dimensional (3D) Computational Fluid Dynamics (CFD) model with embedded pore scale calculations is implemented to predict flow, heat and mass transfer in the DCMD module. Model validation is carried out in terms of average permeate fluxes with experimental data of seawater desalination using two commercially available PTFE membranes. Average permeate fluxes agree within 6% and less with experimental values without fitting parameters. Simulation results show that the distribution of permeate fluxes and seawater salinity over the membrane surface are strongly dependent on momentum and heat transport and that temperature and concentration polarization follow closely the flow distribution. The analysis reveals a drastic effect of recirculation loops and dead zones on module performance and recommendations to improve MD flat module design are drawn consequently.

  2. Interactions between oxygen permeation and homogeneous-phase fuel conversion on the sweep side of an ion transport membrane

    KAUST Repository

    Hong, Jongsup; Kirchen, Patrick; Ghoniem, Ahmed F.

    2013-01-01

    concentration enhances oxygen permeation substantially. This is accomplished through promoting oxidation reactions (oxygen consumption) and the transport of the products and reaction heat towards the membrane, which lowers the oxygen concentration and increases

  3. Effect of feed flow pattern on the distribution of permeate fluxes in desalination by direct contact membrane distillation

    KAUST Repository

    Soukane, Sofiane; Naceur, Mohamed W.; Francis, Lijo; Alsaadi, Ahmad Salem; Ghaffour, NorEddine

    2017-01-01

    The current study aims to highlight the effect of flow pattern on the variations of permeate fluxes over the membrane surface during desalination in a direct contact membrane distillation (DCMD) flat module. To do so, a three dimensional (3D

  4. Gas separation process using membranes with permeate sweep to remove CO.sub.2 from gaseous fuel combustion exhaust

    Science.gov (United States)

    Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

    2012-05-15

    A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.

  5. The JET gas baking plant for DT operation and analysis of tritium permeation and baking gas activation in DTE1

    Energy Technology Data Exchange (ETDEWEB)

    Pearce, R.J.H.; Andrew, P.; Bryan, S.; Hemmrich, J.L. [JET Joint Undertaking, Abingdon, Oxon (United Kingdom)

    1998-07-01

    The JET gas baking plant allows the vacuum vessel to be heated for conditioning and plasma operations. The vessel was maintained at 320 deg. C for the JET DT experiments (DTE 1). The design of the plant is outlined with particular reference to the features to provide compatibility with tritium operations. The experience of baking gas activation and tritium permeation into the plant are given, Developmentsto reduce the tritium permeation out of the vessel are considered. (authors)

  6. Preparation of Silica Nanoparticles Loaded with Nootropics and Their In Vivo Permeation through Blood-Brain Barrier

    OpenAIRE

    Jampilek, Josef; Zaruba, Kamil; Oravec, Michal; Kunes, Martin; Babula, Petr; Ulbrich, Pavel; Brezaniova, Ingrid; Opatrilova, Radka; Triska, Jan; Suchy, Pavel

    2015-01-01

    The blood-brain barrier prevents the passage of many drugs that target the central nervous system. This paper presents the preparation and characterization of silica-based nanocarriers loaded with piracetam, pentoxifylline, and pyridoxine (drugs from the class of nootropics), which are designed to enhance the permeation of the drugs from the circulatory system through the blood-brain barrier. Their permeation was compared with non-nanoparticle drug substances (bulk materials) by means of an i...

  7. PermeaLoop™, a novel in vitro tool for small-scale drug-dissolution/permeation studies

    DEFF Research Database (Denmark)

    Sironi, Daniel; Rosenberg, Jörg; Bauer-Brandl, Annette

    2018-01-01

    dissolution and permeation, as it is occurring in vivo. We propose a novel setup with a high area-to-volume ratio and report as a model case the dissolution/permeation behavior of an enabling formulation of the poorly soluble and poorly permeable drug ABT-869. Mini tablets consisting of an amorphous solid......Loop™ is regarded a promising tool for evaluating enabling formulations....

  8. Hydrogen permeation measurement of the reduced activation ferritic steel F82H by the vacuum thermo-balance method

    International Nuclear Information System (INIS)

    Yoshida, Hajime; Enoeda, Mikio; Abe, Tetsuya; Akiba, Masato

    2005-03-01

    Hydrogen permeation fluxes of the reduced activation ferritic steel F82H were quantitatively measured by a newly proposed method, vacuum thermo-balance method, for a precise estimation of tritium leakage in a fusion reactor. We prepared sample capsules made of F82H, which enclosed hydrogen gas. The hydrogen in the capsules permeated through the capsule wall, and subsequently desorbed from the capsule surface during isothermal heating. The vacuum thermo-balance method allows simultaneous measurement of the hydrogen permeation flux by two independent methods, namely, the net weight reduction of the sample capsule and exhaust gas analysis. Thus the simultaneous measurements by two independent methods increase the reliability of the permeability measurement. When the gas pressure of enclosed hydrogen was 0.8 atm at the sample temperature of 673 K, the hydrogen permeation flux of F82H obtained by the net weight reduction and the exhaust gas analysis was 0.75x10 18 (H 2 /m 2 s) and 2.2x10 18 (H 2 /m 2 s), respectively. The ratio of the hydrogen permeation fluxes obtained by the net weight reduction to that measured by the exhaust gas analysis was in the range from 1/4 to 1/1 in this experiment. The temperature dependence of the estimated permeation flux was similar in both methods. Taking the uncertainties of both measurements into consideration, both results are supposed to be consistent. The enhancement of hydrogen permeation flux was observed from the sample of which outer surface was mechanically polished. Through the present experiments, it has been demonstrated that the vacuum thermo-balance method is effective for the measurement of hydrogen permeation rate of F82H. (author)

  9. In vitro permeation of palladium powders through intact and damaged human skin.

    Science.gov (United States)

    Crosera, Matteo; Mauro, Marcella; Bovenzi, Massimo; Adami, Gianpiero; Baracchini, Elena; Maina, Giovanni; Larese Filon, Francesca

    2018-05-01

    The use of palladium (Pd) has grown in the last decades, commonly used in automotive catalytic converters, jewellery and dental restorations sectors. Both general and working population can be exposed to this metal, which may act as skin sensitizer. This study investigated in vitro palladium powders permeation through excised intact and damaged human skin using the Franz diffusion cell method and the effect of rapid skin decontamination using sodium laureth-sulphate. 1 mL of a 10 min sonicated suspension made of 2.5 g of Pd powder in 50 mL synthetic sweat at pH 4.5 and room temperature was applied to the outer surface of the skin membranes for 24 h. Pd permeation, assessed by ICP-MS, was higher when damaged skin was used (p = 0.03). Final flux permeation values and lag times were 0.02 ± 0.01 μg cm -2  h -1 and 6.00 ± 3.95 h for intact, and 0.10 ± 0.02 μg cm -2  h -1 and 2.05 ± 1.49 h for damaged skin samples, respectively. Damaged skin protocol enhances Pd skin penetration inside dermal layer (p = 0.04), thus making the metal available for systemic uptake. Pd penetration (p = 0.02) and permeation (p = 0.012) through intact skin decreased significantly when a cleaning procedure was applied. This study demonstrates that after skin exposure to Pd powders a small permeation of the metal happen both through intact and damaged skin and that an early decontamination with a common cleanser can significantly decrease the final amount of metal available forsystemic uptake. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Lyophilized phytosomal nanocarriers as platforms for enhanced diosmin delivery: optimization and ex vivo permeation

    Directory of Open Access Journals (Sweden)

    Freag MS

    2013-07-01

    Full Text Available May S Freag, Yosra SR Elnaggar, Ossama Y AbdallahDepartment of Pharmaceutics, Faculty of Pharmacy, Alexandria University, Alexandria, EgyptAbstract: Diosmin (DSN is an outstanding phlebotonic flavonoid with a tolerable potential for the treatment of colon and hepatocellular carcinoma. Being highly insoluble, DSN bioavailability suffers from high inter-subject variation due to variable degrees of permeation. This work endeavored to develop novel DSN loaded phytosomes in order to improve drug dissolution and intestinal permeability. Three preparation methods (solvent evaporation, salting out, and lyophilization were compared. Nanocarrier optimization encompassed different soybean phospholipid (SPC types, different solvents, and different DSN:SPC molar ratios (1:1, 1:2, and 1:4. In vitro appraisal encompassed differential scanning calorimetry, infrared spectroscopy, particle size, zeta potential, polydispersity index, transmission electron microscopy, drug content, and in vitro stability. Comparative dissolution studies were performed under sink versus non-sink conditions. Ex vivo intestinal permeation studies were performed on rats utilizing noneverted sac technique and high-performance liquid chromatography analysis. The results revealed lyophilization as the optimum preparation technique using SPC and solvent mixture (Dimethyl sulphoxide:t-butylalchol in a 1:2 ratio. Complex formation was contended by differential scanning calorimetry and infrared data. Optimal lyophilized phytosomal nanocarriers (LPNs exhibited the lowest particle size (316 nm, adequate zeta-potential (−27 mV, and good in vitro stability. Well formed, discrete vesicles were revealed by transmission electron microscopy, drug content, and in vitro stability. Comparative dissolution studies were performed. LPNs demonstrated significant enhancement in DSN dissolution compared to crude drug, physical mixture, and generic and brand DSN products. Permeation studies revealed 80% DSN

  11. Optimisation of cosolvent concentration for topical drug delivery III--influence of lipophilic vehicles on ibuprofen permeation.

    Science.gov (United States)

    Watkinson, R M; Guy, R H; Oliveira, G; Hadgraft, J; Lane, M E

    2011-01-01

    Previously, we have reported the effects of water, ethanol, propylene glycol and various binary and ternary mixtures of these solvents on the permeation of ibuprofen in model membranes and in skin. The present study investigates the influence of lipophilic vehicles on the transport of ibuprofen in silicone membrane and in human skin. The permeation of ibuprofen was measured from mineral oil (MO), Miglyol® 812 (MG) and binary mixtures of MO and MG. The solubility of ibuprofen was 5-fold higher in MG than in MO, however, the permeation of ibuprofen from the pure vehicles and combinations of both was comparable in silicone membrane. Additionally, there were no significant differences in skin permeation for MO and MG vehicles. When the permeation of various hydrophilic and lipophilic vehicles is considered, a trend between flux values for the model membrane and skin is evident (r(2) = 0.71). The findings suggest that silicone membrane may provide information on qualitative trends in skin permeation for vehicles of diverse solubility and partition characteristics. Copyright © 2010 S. Karger AG, Basel.

  12. Transdermal delivery of diclofenac using water-in-oil microemulsion: formulation and mechanistic approach of drug skin permeation.

    Science.gov (United States)

    Thakkar, Priyanka J; Madan, Parshotam; Lin, Senshang

    2014-05-01

    The objective of the present investigation was to enhance skin permeation of diclofenac using water-in-oil microemulsion and to elucidate its skin permeation mechanism. The w/o microemulsion formulations were selected based on constructed pseudoternary phase diagrams depending on water solubilization capacity and thermodynamic stability. These formulations were also subjected to physical characterization based on droplet size, viscosity, pH and conductivity. Permeation of diclofenac across rat skin using side-by-side permeation cells from selected w/o microemulsion formulations were evaluated and compared with control formulations. The selected w/o microemulsion formulations were thermodynamically stable, and incorporation of diclofenac sodium into microemulsion did not affect the phase behavior of system. All microemulsion formulations had very low viscosity (11-17 cps) and droplet size range of 30-160 nm. Microemulsion formulations exhibited statistically significant increase in diclofenac permeation compared to oily solution, aqueous solution and oil-Smix solution. Higher skin permeation of diclofenac was observed with low Smix concentration and smaller droplet size. Increase in diclofenac loading in aqueous phase decreased the partition of diclofenac. Diclofenac from the oil phase of microemulsion could directly partition into skin, while diclofenac from the aqueous droplets was carried through skin by carrier effect.

  13. Importance of the Direct Contact of Amorphous Solid Particles with the Surface of Monolayers for the Transepithelial Permeation of Curcumin.

    Science.gov (United States)

    Kimura, Shunsuke; Kasatani, Sachiha; Tanaka, Megumi; Araki, Kaeko; Enomura, Masakazu; Moriyama, Kei; Inoue, Daisuke; Furubayashi, Tomoyuki; Tanaka, Akiko; Kusamori, Kosuke; Katsumi, Hidemasa; Sakane, Toshiyasu; Yamamoto, Akira

    2016-02-01

    The amorphization has been generally known to improve the absorption and permeation of poorly water-soluble drugs through the enhancement of the solubility. The present study focused on the direct contact of amorphous solid particles with the surface of the membrane using curcumin as a model for water-insoluble drugs. Amorphous nanoparticles of curcumin (ANC) were prepared with antisolvent crystallization method using a microreactor. The solubility of curcumin from ANC was two orders of magnitude higher than that of crystalline curcumin (CC). However, the permeation of curcumin from the saturated solution of ANC was negligible. The transepithelial permeation of curcumin from ANC suspension was significantly increased as compared to CC suspension, while the permeation was unlikely correlated with the solubility, and the increase in the permeation was dependent on the total concentration of curcumin in ANC suspension. The absorptive transport of curcumin (from apical to basal, A to B) from ANC suspension was much higher than the secretory transport (from basal to apical, B to A). In vitro transport of curcumin through air-interface monolayers is large from ANC but negligible from CC particles. These findings suggest that the direct contact of ANC with the absorptive membrane can play an important role in the transport of curcumin from ANC suspension. The results of the study suggest that amorphous particles may be directly involved in the transepithlial permeation of curcumin.

  14. Interactions between oxygen permeation and homogeneous-phase fuel conversion on the sweep side of an ion transport membrane

    KAUST Repository

    Hong, Jongsup

    2013-02-01

    The interactions between oxygen permeation and homogeneous fuel oxidation reactions on the sweep side of an ion transport membrane (ITM) are examined using a comprehensive model, which couples the dependency of the oxygen permeation rate on the membrane surface conditions and detailed chemistry and transport in the vicinity of the membrane. We assume that the membrane surface is not catalytic to hydrocarbon or syngas oxidation. Results show that increasing the sweep gas inlet temperature and fuel concentration enhances oxygen permeation substantially. This is accomplished through promoting oxidation reactions (oxygen consumption) and the transport of the products and reaction heat towards the membrane, which lowers the oxygen concentration and increases the gas temperature near the membrane. Faster reactions at higher fuel concentration and higher inlet gas temperature support substantial fuel conversion and lead to a higher oxygen permeation flux without the contribution of surface catalytic activity. Beyond a certain maximum in the fuel concentration, extensive heat loss to the membrane (and feed side) reduces the oxidation kinetic rates and limits oxygen permeation as the reaction front reaches the membrane. The sweep gas flow rate and channel height have moderate impacts on oxygen permeation and fuel conversion due to the residence time requirements for the chemical reactions and the location of the reaction zone relative to the membrane surface. © 2012 Elsevier B.V.

  15. Comparison of Hexane Vapour Permeation in Two Different Polymeric Membranes via an Innovative In-line FID Detection Method

    Directory of Open Access Journals (Sweden)

    Z. Petrusová

    2017-07-01

    Full Text Available This manuscript presents a novel method for the analysis of vapour permeation through polymeric membranes based on in-line analysis of the permeate with an FID detector. The hexane vapour permeation was studied for two commercially available membranes, namely low-density polyethylene (LDPE and thin-film-composite polyamide (PA membrane. The hexane permeation was studied at temperatures of 25–45 °C, hexane vapour activity in the range of 0.2–0.8 and trans-membrane pressures of 5–50 kPa. Two fundamentally different membranes were chosen to demonstrate the potential and sensitivity of the permeation apparatus. Upon increasing the temperature from 25 to 45 °C, the flux in LDPE was found to increase almost fourfold over the whole activity range. The nonlinear increase of the flux with activity indicates plasticization of the polymer by hexane. Contrarily, the flux in the PA membrane increases almost linearly with activity, with only a minor upward curvature. Since the PA is far away from any phase transition, it is less temperature-dependent than LDPE. The activation energy for permeation demonstrates that the temperature dependence in the LDPE membrane is dominated by changes in diffusion, whereas it is dominated by changes in solubility in the PA membrane.

  16. Development of Acyclovir-Loaded Albumin Nanoparticles and Improvement of Acyclovir Permeation Across Human Corneal Epithelial T Cells.

    Science.gov (United States)

    Suwannoi, Panita; Chomnawang, Mullika; Sarisuta, Narong; Reichl, Stephan; Müller-Goymann, Christel C

    2017-12-01

    The aim of the present study was to develop acyclovir (ACV) ocular drug delivery systems of bovine serum albumin (BSA) nanoparticles as well as to assess their in vitro transcorneal permeation across human corneal epithelial (HCE-T) cell multilayers. The ACV-loaded BSA nanoparticles were prepared by desolvation method along with physicochemical characterization, cytotoxicity, as well as in vitro transcorneal permeation studies across HCE-T cell multilayers. The nanoparticles appeared to be spherical in shape and nearly uniform in size of about 200 nm. The size of nanoparticles became smaller with decreasing BSA concentration, while the ratios of water to ethanol seemed not to affect the size. Increasing the amount of ethanol in desolvation process led to significant reduction of drug entrapment of nanoparticles with smaller size and more uniformity. The ACV-loaded BSA nanoparticles prepared were shown to have no cytotoxic effect on HCE-T cells used in permeation studies. The in vitro transcorneal permeation results revealed that ACV could permeate through the HCE-T cell multilayers significantly higher from BSA nanoparticles than from aqueous ACV solutions. The ACV-loaded BSA nanoparticles could be prepared by desolvation method without glutaraldehyde in the formulation. ACV could increasingly permeate through the multilayers of HCE-T cells from the ACV-loaded BSA nanoparticles. Therefore, the ACV-loaded BSA nanoparticles could be a highly potential ocular drug delivery system.

  17. Hydrogen permeation resistant heat pipe for bi-modal reactors. Final report, October 1, 1994--September 30, 1995

    International Nuclear Information System (INIS)

    North, M.T.; Anderson, W.G.

    1995-01-01

    The principal objective of this program was to demonstrate technology that will make a sodium heat pipe tolerant of hydrogen permeation for a bimodal space reactor application. Special focus was placed on techniques which enhance the permeation of hydrogen out of the heat pipe. Specific objectives include: define the detailed requirements for the bimodal reactor application; design and fabricate a prototype heat pipe tolerant of hydrogen permeation; and test the prototype heat pipe and demonstrate that hydrogen which permeates into the heat pipe is removed or reduced to acceptable levels. The results of the program were fully successful. Analyses were performed on two different heat pipe designs and an experimental heat pipe was fabricated and tested. A model of the experimental heat pipe was developed to predict the enhancement in the hydrogen permeation rate out of the heat pipe. A significant improvement in the rate at which hydrogen permeates out of a heat pipe was predicted for the use of the special condenser geometry developed here. Agreement between the model and the experimental results was qualitatively good. Inclusion of the additional effects of fluid flow in the heat pipe are recommended for future work

  18. Incorporation of whey permeate, a dairy effluent, in ethanol fermentation to provide a zero waste solution for the dairy industry.

    Science.gov (United States)

    Parashar, Archana; Jin, Yiqiong; Mason, Beth; Chae, Michael; Bressler, David C

    2016-03-01

    This study proposes a novel alternative for utilization of whey permeate, a by-product stream from the dairy industry, in wheat fermentation for ethanol production using Saccharomyces cerevisiae. Whey permeates were hydrolyzed using enzymes to release fermentable sugars. Hydrolyzed whey permeates were integrated into wheat fermentation as a co-substrate or to partially replace process water. Cold starch hydrolysis-based simultaneous saccharification and fermentation was done as per the current industrial protocol for commercial wheat-to-ethanol production. Ethanol production was not affected; ethanol yield efficiency did not change when up to 10% of process water was replaced. Lactic acid bacteria in whey permeate did not negatively affect the co-fermentation or reduce ethanol yield. Whey permeate could be effectively stored for up to 4 wk at 4 °C with little change in lactose and lactic acid content. Considering the global abundance and nutrient value of whey permeate, the proposed strategy could improve economics of the dairy and biofuel sectors, and reduce environmental pollution. Furthermore, our research may be applied to fermentation strategies designed to produce value-added products other than ethanol. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  19. Measuring the molecular dimensions of wine tannins: comparison of small-angle X-ray scattering, gel-permeation chromatography and mean degree of polymerization.

    Science.gov (United States)

    McRae, Jacqui M; Kirby, Nigel; Mertens, Haydyn D T; Kassara, Stella; Smith, Paul A

    2014-07-23

    The molecular size of wine tannins can influence astringency, and yet it has been unclear as to whether the standard methods for determining average tannin molecular weight (MW), including gel-permeation chromatography (GPC) and depolymerization reactions, are actually related to the size of the tannin in wine-like conditions. Small-angle X-ray scattering (SAXS) was therefore used to determine the molecular sizes and corresponding MWs of wine tannin samples from 3 and 7 year old Cabernet Sauvignon wine in a variety of wine-like matrixes: 5-15% and 100% ethanol; 0-200 mM NaCl and pH 3.0-4.0, and compared to those measured using the standard methods. The SAXS results indicated that the tannin samples from the older wine were larger than those of the younger wine and that wine composition did not greatly impact on tannin molecular size. The average tannin MWs as determined by GPC correlated strongly with the SAXS results, suggesting that this method does give a good indication of tannin molecular size in wine-like conditions. The MW as determined from the depolymerization reactions did not correlate as strongly with the SAXS results. To our knowledge, SAXS measurements have not previously been attempted for wine tannins.

  20. Selective Permeation and Organic Extraction of Recombinant Green Fluorescent Protein (gfpuv from Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ishii Marina

    2002-04-01

    Full Text Available Abstract Background Transformed cells of Escherichia coli DH5-α with pGFPuv, induced by IPTG (isopropyl-β-d-thiogalactopyranoside, express the green fluorescent protein (gfpuv during growth phases. E. coli subjected to the combination of selective permeation by freezing/thawing/sonication cycles followed by the three-phase partitioning extraction (TPP method were compared to the direct application of TPP to the same culture of E. coli on releasing gfpuv from the over-expressing cells. Material and Methods Cultures (37°C/100 rpm/ 24 h; μ = 0.99 h-1 - 1.10 h-1 of transformed (pGFP Escherichia coli DH5-α, expressing the green fluorescent protein (gfpuv, absorbance at 394 nm and emission at 509 nm were sonicated in successive intervals of sonication (25 vibrations/pulse to determine the maximum amount of gfpuv released from the cells. For selective permeation, the transformed previously frozen (-75°C cells were subjected to three freeze/thaw (-20°C/ 0.83°C/min cycles interlaid by sonication (3 pulses/ 6 seconds/ 25 vibrations. The intracellular permeate with gfpuv in extraction buffer (TE solution (25 mM Tris-HCl, pH 8.0, 1 mM β-mercaptoethanol β-ME, 0.1 mM PMSF was subjected to the three-phase partitioning (TPP method with t-butanol and 1.6 M ammonium sulfate. Sonication efficiency was verified on the application to the cells previously treated by the TPP method. The intra-cell releases were mixed and eluted through methyl HIC column with a buffer solution (10 mM Tris-HCl, 10 mM EDTA, pH 8.0. Results The sonication maximum released amount obtained from the cells was 327.67 μg gfpuv/mL (20.73 μg gfpuv/mg total proteins – BSA, after 9 min of treatment. Through the selective permeation by three repeated freezing/thawing/sonication cycles applied to the cells, a close content of 241.19 μg gfpuv/mL (29.74 μg gfpuv/mg BSA was obtained. The specific mass range of gfpuv released from the same cultures, by the three-phase partitioning (TPP

  1. Enhancement of Skin Permeation and Skin Immunization of Ovalbumin Antigen via Microneedles.

    Science.gov (United States)

    Pamornpathomkul, Boonnada; Rojanarata, Theerasak; Opanasopit, Praneet; Ngawhirunpat, Tanasait

    2017-10-01

    The purpose of this study was to evaluate the use of different types of microneedles and doses of ovalbumin antigen for in vitro skin permeation and in vivo immunization. In vitro skin permeation experiments and confocal laser scanning microscopy revealed that hollow microneedles had a superior enhancing effect on skin permeation compared with a solid microneedle patch and untreated skin by efficiently delivering ovalbumin-fluorescein conjugate into the deep skin layers. The flux and cumulative amount of ovalbumin-fluorescein conjugate at 8 h after administering with various conditions could be ranked as follows: hollow MN; high dose > medium dose > low dose > MN patch; high dose > medium dose > low dose > untreated skin; high dose > medium dose > low dose > without ovalbumin-fluorescein conjugate. As the dose of ovalbumin-fluorescein conjugate was increased to 500 μg, the antigen accumulated in the skin to a greater extent, as evidenced by the increasing green fluorescence intensity. When the hollow microneedle was used for the delivery of ovalbumin into the skin of mice, it was capable of inducing a stronger immunoglobulin G immune response than conventional subcutaneous injection at the same antigen dose. Immunoglobulin G levels in the hollow MN group were 5.7, 11.6, and 13.3 times higher than those of the subcutaneous injection group for low, medium, and high doses, respectively. Furthermore, the mice immunized using the hollow microneedle showed no signs of skin infection or pinpoint bleeding. The results suggest that the hollow MN is an efficient device for delivering the optimal dose of antigen via the skin for successful immunization.

  2. Permeation of platinum and rhodium nanoparticles through intact and damaged human skin

    International Nuclear Information System (INIS)

    Mauro, Marcella; Crosera, Matteo; Bianco, Carlotta; Adami, Gianpiero; Montini, Tiziano; Fornasiero, Paolo; Jaganjac, Morana; Bovenzi, Massimo; Filon, Francesca Larese

    2015-01-01

    The aim of the study was to evaluate percutaneous penetration of platinum and rhodium nanoparticles (PtNPs: 5.8 ± 0.9 nm, RhNPs: 5.3 ± 1.9 nm) through human skin. Salts compounds of these metals are sensitizers and some also carcinogenic agents. In vitro permeation experiments were performed using Franz diffusion cells with intact and damaged skin. PtNPs and RhNPs, stabilized with polyvinylpyrrolidone, were synthesized by reduction of Na 2 PtC l6 and RhCl 3 ·3H 2 O respectively. Suspensions with a concentration of 2.0 g/L of PtNPs and RhNPs were dispersed separately in synthetic sweat at pH 4.5 and applied as donor phases to the outer surface of the skin for 24 h. Measurements of the content of the metals in the receiving solution and in the skin were performed subsequently. Rhodium skin permeation was demonstrated through damaged skin, with a permeation flux of 0.04 ± 0.04 μg cm −2  h −1 and a lag time of 7.9 ± 1.1 h, while no traces of platinum were found in receiving solutions. Platinum and rhodium skin-analysis showed significantly higher concentrations of the metals in damaged skin. Rh and Pt applied as NPs can penetrate the skin barrier and Rh can be found in receiving solutions. These experiments pointed out the need for skin contamination prevention, since even a minor injury to the skin barrier can significantly increase penetration

  3. Collagen-based silver nanoparticles: Study on cell viability, skin permeation, and swelling inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Saura Cardoso, Vinicius, E-mail: vscfisio@ufpi.edu.br [Research Center in Biodiversity and Biotechnology, Biotec, Campus Ministro Reis Velloso, Federal University of Piauí, UFPI, 64202020 Parnaíba, Piauí (Brazil); Physiotherapy Department, Campus Ministro Reis Velloso, Federal University of Piauí, UFPI, 64202020 Parnaíba, Piauí (Brazil); Carvalho Filgueiras, Marcelo de; Medeiros Dutra, Yago; Gomes Teles, Ramon Handerson [Physiotherapy Department, Campus Ministro Reis Velloso, Federal University of Piauí, UFPI, 64202020 Parnaíba, Piauí (Brazil); Morphology and Muscle Physiology Laboratory, LAMFIM, Campus Ministro Reis Velloso, Federal University of Piauí, UFPI, 64202020 Parnaíba, Piauí (Brazil); Rodrigues de Araújo, Alyne [Research Center in Biodiversity and Biotechnology, Biotec, Campus Ministro Reis Velloso, Federal University of Piauí, UFPI, 64202020 Parnaíba, Piauí (Brazil); Primo, Fernando Lucas [Faculdade de Ciências Farmacêuticas, UNESP, Universidade Estadual Paulista, Campus de Araraquara, Departamento de Bioprocessos e Biotecnologia, 14800903 Araraquara, São Paulo (Brazil); Mafud, Ana Carolina; Batista, Larissa Fernandes; Mascarenhas, Yvonne Primerano [Institute of Physics of São Carlos, IFSC, University of São Paulo, USP, 13566590 São Carlos, SP (Brazil); and others

    2017-05-01

    Collagen is considered the most abundant protein in the animal kingdom, comprising 30% of the total amount of proteins and 6% of the human body by weight. Studies that examine the interaction between silver nanoparticles and proteins have been highlighted in the literature in order to understand the stability of the nanoparticle system, the effects observed in biological systems, and the appearance of new chemical pharmaceutical products. The objective of this study was to analyze the behavior of silver nanoparticles stabilized with collagen (AgNPcol) and to check the skin permeation capacity and action in paw edema induced by carrageenan. AgNPcol synthesis was carried out using solutions of reducing agent sodium borohydride (NaBH{sub 4}), silver nitrate (AgNO{sub 3}) and collagen. Characterization was done by using dynamic light scattering (DLS) and X-ray diffraction (XRD) and AFM. Cellular viability testing was performed by using flow cytometry in human melanoma cancer (MV3) and murine fibroblast (L929) cells. The skin permeation study was conducted using a Franz diffusion cell, and the efficiency of AgNPcol against the formation of paw edema in mice was evaluated. The hydrodynamic diameter and zeta potential of AgNPcol were 140.7 ± 7.8 nm and 20.1 ± 0.7 mV, respectively. AgNPcol failed to induce early apoptosis, late apoptosis, and necrosis in L929 cells; however, it exhibited enhanced toxicity in cancer cells (MV3) compared to normal cells (L929). AgNPcol demonstrated increased toxicological effects in cancer MV3 cells, promoting skin permeation, and preventing paw edema. - Highlights: • Silver nanoparticles were synthesized with type I collagen (AgNPcol). • AgNPcol which was characterized by XRD and DLS. • AgNPcol exhibited enhanced toxicity in cancer cells. • The efficiency of the AgNPcol against the paw edema was evaluated.

  4. Collagen-based silver nanoparticles: Study on cell viability, skin permeation, and swelling inhibition

    International Nuclear Information System (INIS)

    Saura Cardoso, Vinicius; Carvalho Filgueiras, Marcelo de; Medeiros Dutra, Yago; Gomes Teles, Ramon Handerson; Rodrigues de Araújo, Alyne; Primo, Fernando Lucas; Mafud, Ana Carolina; Batista, Larissa Fernandes; Mascarenhas, Yvonne Primerano

    2017-01-01

    Collagen is considered the most abundant protein in the animal kingdom, comprising 30% of the total amount of proteins and 6% of the human body by weight. Studies that examine the interaction between silver nanoparticles and proteins have been highlighted in the literature in order to understand the stability of the nanoparticle system, the effects observed in biological systems, and the appearance of new chemical pharmaceutical products. The objective of this study was to analyze the behavior of silver nanoparticles stabilized with collagen (AgNPcol) and to check the skin permeation capacity and action in paw edema induced by carrageenan. AgNPcol synthesis was carried out using solutions of reducing agent sodium borohydride (NaBH 4 ), silver nitrate (AgNO 3 ) and collagen. Characterization was done by using dynamic light scattering (DLS) and X-ray diffraction (XRD) and AFM. Cellular viability testing was performed by using flow cytometry in human melanoma cancer (MV3) and murine fibroblast (L929) cells. The skin permeation study was conducted using a Franz diffusion cell, and the efficiency of AgNPcol against the formation of paw edema in mice was evaluated. The hydrodynamic diameter and zeta potential of AgNPcol were 140.7 ± 7.8 nm and 20.1 ± 0.7 mV, respectively. AgNPcol failed to induce early apoptosis, late apoptosis, and necrosis in L929 cells; however, it exhibited enhanced toxicity in cancer cells (MV3) compared to normal cells (L929). AgNPcol demonstrated increased toxicological effects in cancer MV3 cells, promoting skin permeation, and preventing paw edema. - Highlights: • Silver nanoparticles were synthesized with type I collagen (AgNPcol). • AgNPcol which was characterized by XRD and DLS. • AgNPcol exhibited enhanced toxicity in cancer cells. • The efficiency of the AgNPcol against the paw edema was evaluated.

  5. Fabrication of lipidic nanocarriers of loratadine for facilitated intestinal permeation using multivariate design approach.

    Science.gov (United States)

    Verma, Samridhi; Singh, Sandeep Kumar; Verma, Priya Ranjan Prasad

    2016-01-01

    In this investigation, multivariate design approach was employed to develop self-nanoemulsifying drug delivery system (SNEDDS) of loratadine and to exploit its potential for intestinal permeability. Drug solubility was determined in various vehicles and existence of self-nanoemulsifying region was evaluated by phase diagram studies. The influence of formulation variables X1 (Capmul MCM C8) and X2 (Solutol HS15) on SNEDDS was assessed for mean globule sizes in different media (Y1-Y3), emulsification time (Y4) and drug-release parameters (Y5-Y6), to improve quality attributes of SNEDDS. Significant models were generated, statistically analyzed by analysis of variance and validated using the residual and leverage plots. The interaction, contour and response plots explicitly demonstrated the influence of one factor on the other and displayed trend of factor-effect on responses. The pH-independent optimized formulation was obtained with appreciable global desirability (0.9266). The strenuous act of determining emulsification time is innovatively replaced by the use of oil-soluble dye to produce visibly distinct globules that otherwise may be deceiving. TEM images displayed non-aggregated state of spherical globules (size < 25 nm) and also revealed the structural transitions occurring during emulsification. Optimized formulation exhibited non-Newtonian flow justified by the model-fit and also presented the stability to dilution effects and thermodynamic stress testing. The ex vivo permeation study using confocal laser scanning microscopy indicate strong potential of rhodamine 123-loaded loratadine-SNEDDS to inhibit P-gp efflux and facilitate intestinal permeation. To conclude, the effectiveness of design yields a stable optimized SNEDDS with enhanced permeation potential, which is expected to improve oral bioavailability of loratadine.

  6. Effects of water-channel attractions on single-file water permeation through nanochannels

    International Nuclear Information System (INIS)

    Xu, Yousheng; Zheng, Youqu; Tian, Xingling; Lv, Mei; He, Bing; Deng, Maolin; Xiu, Peng; Tu, Yusong

    2016-01-01

    Single-file transportation of water across narrow nanochannels such as carbon nanotubes has attracted much attention in recent years. Such permeation can be greatly affected by the water-channel interactions; despite some progress, this issue has not been fully explored. Herein we use molecular dynamics simulations to investigate the effects of water-channel attractions on occupancy, translational (transportation) and orientational dynamics of water inside narrow single-walled carbon nanotubes (SWNTs). We use SWNTs as the model nanochannels and change the strength of water-nanotube attractions to mimic the changes in the hydrophobicity/polarity of the nanochannel. We investigate the dependence of water occupancy inside SWNTs on the water-channel attraction and identify the corresponding threshold values for drying states, wetting-drying transition states, and stably wetting states. As the strength of water-channel attractions increases, water flow increases rapidly first, and then decreases gradually; the maximal flow occurs in the case where the nanochannel is predominately filled with the 1D water wire but with a small fraction of ‘empty states’, indicating that appropriate empty-filling (drying-wetting) switching can promote water permeation. This maximal flow is unexpected, since in traditional view, the stable and tight hydrogen-bonding network of the water wire is the prerequisite for high permeability of water. The underlying mechanism is discussed from an energetic perspective. In addition, the effect of water-channel attractions on reorientational dynamics of the water wire is studied, and a negative correlation between the flipping frequency of water wire and the water-channel attraction is observed. The underlying mechanism is interpreted in term of the axial total dipole moment of inner water molecules. This work would help to better understand the effects of water-channel attractions on wetting properties of narrow nanochannels, and on single

  7. Permeation measurement of gestodene for some biodegradable materials using Franz diffusion cells.

    Science.gov (United States)

    Liu, Danhua; Zhang, Chong; Zhang, Xiaowei; Zhen, Zhu; Wang, Ping; Li, Jianxin; Yi, Dongxu; Jin, Ying; Yang, Dan

    2015-09-01

    Biodegradable poly(d,l-lactide) (PDLLA), Poly(trimethylene carbonate) (PTMC), polycaprolactone (PCL), poly(caprolactone-co-d,l-lactide) (PCDLLA) and poly(trimethylene carbonate-co-caprolactone) (PTCL) are recently used for clinical drug delivery system such as subcutaneous contraceptive implant capsule due to their biodegradable properties that they could possess long-term stable performance in vivo without removal, however their permeation rate is unknown. In the work, biodegradable material membranes were prepared by solvent evaporation using chloroform, and commercial silicone rubber membrane served as a control. Gestodene was used as a model drug. Gestodene has high biologic progestational activity which allows for high contraceptive reliability at very low-dose levels. The permeation rate of gestodene for several biodegradable materials was evaluated. In vitro diffusion studies were done using Franz diffusion cells with a diffusion area of 1.33 cm(2). Phosphate buffer solution (PBS, pH 7.4), 10% methanol solution and distilled water were taken in donor and receiver chambers at temperature of 37 °C respectively. The in vitro experiments were conducted over a period of 24 h during which samples were collected at regular intervals. The withdrawn samples were appropriately diluted and measured on UV-vis spectrophotometer at 247 nm. Conclusion data from our study showed that permeation rate of PCDLLA with CL ratio more than 70% could be more excellent than commercial silicone rubber membrane. They may be suitable as a candidate carrier for gestodene subcutaneous contraceptive implants in contraceptive fields.

  8. The permeation of tritium through 316L stainless steel with multiple coatings

    International Nuclear Information System (INIS)

    Yao Zhenyu; Hao Jiakun; Zhou Changshan; Shan Changqi; Yu Jinnan

    2000-01-01

    TiN + TiC + TiN and TiN + TiC + SiO 2 films were deposited on the surface of 316L austenitic stainless steel by means of physical vapor deposition (PVD). The thickness of the films was about 2-3 μm. The film is compact, oxidation-resistant, and has good adherence with the substrate below 500 deg. C. Tritium gas permeation of 316L with multiple films was examined, and it was found that the tritium permeability in 316L with a TiN + TiC + TiN film was 4-5 orders of magnitude lower, and in 316L with a TiN + TiC + SiO 2 film was 4-6 orders of magnitude lower than that in 316L with a Pd film at about 200-500 deg. C. At about 600 deg. C, the permeability of 316L with the multiple coating was 3-4 orders of magnitude lower than that in 316L with a Pd film. The result shows that the tritium permeation barrier is formed by multiple coating above 300 deg. C, and it is stable below 500 deg. C. However, the barrier is partly destroyed at about 600 deg. C because of oxidation; although this results in degradation of the barrier, it still plays a positive role. These films may be useful as coatings for the first wall, tritium blanket, and heat exchanger in fusion reactors for tritium permeation resistance

  9. Erbium-yttrium-aluminum-garnet laser irradiation ameliorates skin permeation and follicular delivery of antialopecia drugs.

    Science.gov (United States)

    Lee, Woan-Ruoh; Shen, Shing-Chuan; Aljuffali, Ibrahim A; Li, Yi-Ching; Fang, Jia-You

    2014-11-01

    Alopecia usually cannot be cured because of the available drug therapy being unsatisfactory. To improve the efficiency of treatment, erbium-yttrium-aluminum-garnet (Er-YAG) laser treatment was conducted to facilitate skin permeation of antialopecia drugs such as minoxidil (MXD), diphencyprone (DPCP), and peptide. In vitro and in vivo percutaneous absorption experiments were carried out by using nude mouse skin and porcine skin as permeation barriers. Fluorescence and confocal microscopies were used to visualize distribution of permeants within the skin. Laser ablation at a depth of 6 and 10 μm enhanced MXD skin accumulation twofold to ninefold depending on the skin barriers selected. DPCP absorption showed less enhancement by laser irradiation as compared with MXD. An ablation depth of 10 μm could increase the peptide flux from zero to 4.99 and 0.33 μg cm(-2) h(-1) for nude mouse skin and porcine skin, respectively. The laser treatment also promoted drug uptake in the hair follicles, with DPCP demonstrating the greatest enhancement (sixfold compared with the control). The imaging of skin examined by microscopies provided evidence of follicular and intercellular delivery assisted by the Er-YAG laser. Besides the ablative effect of removing the stratum corneum, the laser may interact with sebum to break up the barrier function, increasing the skin delivery of antialopecia drugs. The minimally invasive, well-controlled approach of laser-mediated drug permeation offers a potential way to treat alopecia. This study's findings provide the basis for the first report on laser-assisted delivery of antialopecia drugs. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  10. Permeation of platinum and rhodium nanoparticles through intact and damaged human skin

    Energy Technology Data Exchange (ETDEWEB)

    Mauro, Marcella [University of Trieste, Clinical Unit of Occupational Medicine, Department of Medical Sciences (Italy); Crosera, Matteo; Bianco, Carlotta; Adami, Gianpiero; Montini, Tiziano; Fornasiero, Paolo [University of Trieste, Department of Chemical and Pharmaceutical Sciences (Italy); Jaganjac, Morana [Rudjer Boskovic Institute, Laboratory for Oxidative Stress, Department of Molecular Medicine (Croatia); Bovenzi, Massimo; Filon, Francesca Larese, E-mail: larese@units.it [University of Trieste, Clinical Unit of Occupational Medicine, Department of Medical Sciences (Italy)

    2015-06-15

    The aim of the study was to evaluate percutaneous penetration of platinum and rhodium nanoparticles (PtNPs: 5.8 ± 0.9 nm, RhNPs: 5.3 ± 1.9 nm) through human skin. Salts compounds of these metals are sensitizers and some also carcinogenic agents. In vitro permeation experiments were performed using Franz diffusion cells with intact and damaged skin. PtNPs and RhNPs, stabilized with polyvinylpyrrolidone, were synthesized by reduction of Na{sub 2}PtC{sub l6} and RhCl{sub 3}·3H{sub 2}O respectively. Suspensions with a concentration of 2.0 g/L of PtNPs and RhNPs were dispersed separately in synthetic sweat at pH 4.5 and applied as donor phases to the outer surface of the skin for 24 h. Measurements of the content of the metals in the receiving solution and in the skin were performed subsequently. Rhodium skin permeation was demonstrated through damaged skin, with a permeation flux of 0.04 ± 0.04 μg cm{sup −2} h{sup −1} and a lag time of 7.9 ± 1.1 h, while no traces of platinum were found in receiving solutions. Platinum and rhodium skin-analysis showed significantly higher concentrations of the metals in damaged skin. Rh and Pt applied as NPs can penetrate the skin barrier and Rh can be found in receiving solutions. These experiments pointed out the need for skin contamination prevention, since even a minor injury to the skin barrier can significantly increase penetration.

  11. A simplified model for tritium permeation transient predictions when trapping is active

    International Nuclear Information System (INIS)

    Longhurst, G.R.

    1994-01-01

    This report describes a simplified one-dimensional tritium permeation and retention model. The model makes use of the same physical mechanisms as more sophisticated, time-transient codes such as implantation, recombination, diffusion, trapping and thermal gradient effects. It takes advantage of a number of simplifications and approximations to solve the steady-state problem and then provides interpolating functions to make estimates of intermediate states based on the steady-state solution. Comparison calculations with the verified and validated TMAP4 transient code show good agreement. ((orig.))

  12. A simplified model for tritium permeation transient predictions when trapping is active*1

    Science.gov (United States)

    Longhurst, G. R.

    1994-09-01

    This report describes a simplified one-dimensional tritium permeation and retention model. The model makes use of the same physical mechanisms as more sophisticated, time-transient codes such as implantation, recombination, diffusion, trapping and thermal gradient effects. It takes advantage of a number of simplifications and approximations to solve the steady-state problem and then provides interpolating functions to make estimates of intermediate states based on the steady-state solution. Comparison calculations with the verified and validated TMAP4 transient code show good agreement.

  13. A simplified model for tritium permeation transient predictions when trapping is active

    Energy Technology Data Exchange (ETDEWEB)

    Longhurst, G.R. (Fusion Safety Program, Idaho National Engineering Laboratory, P.O. Box 1625, Idaho Falls, ID 83415 (United States))

    1994-09-01

    This report describes a simplified one-dimensional tritium permeation and retention model. The model makes use of the same physical mechanisms as more sophisticated, time-transient codes such as implantation, recombination, diffusion, trapping and thermal gradient effects. It takes advantage of a number of simplifications and approximations to solve the steady-state problem and then provides interpolating functions to make estimates of intermediate states based on the steady-state solution. Comparison calculations with the verified and validated TMAP4 transient code show good agreement. ((orig.))

  14. Reversed phase parallel artificial membrane permeation assay for log P measurement

    Directory of Open Access Journals (Sweden)

    Zihao Song

    2016-03-01

    Full Text Available A reversed phase parallel artificial membrane permeation assay (RP-PAMPA was newly invented for log P measurement. An oil/water/oil sandwich was constructed using a conventional PAMPA instrument. 1 % agarose was used to improve the physical stability of the water phase. A linear correlation between log P and the apparent permeability was observed in the -0.24 < log P < 2.85 region (R2 = 0.98. RP-PAMPA was also applied to pKa measurement.

  15. Study of poli (ethylene tereftalate) thin films submitted to radiations by using permeation and spectroscopic techniques

    International Nuclear Information System (INIS)

    Andrade, L.A.

    1986-06-01

    Properties of poly (ethylene terephthalate P.E.T. thin films submitted to electric discharges, electron, He + ion and proton beams were investigated using permeation technique, electronic paramagnetic resonance resonance (E.P.R.) and visible and infrared spectroscopies. Experimental apparatuses and procedures are described and the results of the analyses are presented and discussed. The existence of structural modifications in irradiated P.E.T. thin films is confirmed. It is shown that the kind of effects occuring in irradiated P.E.T. depends on the nature of the incident radiation. (author) [pt

  16. Electrochemical permeation tests on the kinetics of the hydrogen absorption of palladium and iron

    International Nuclear Information System (INIS)

    Dafft, E.G.

    1977-01-01

    Electrochemical permeation tests were performed to investigate the kinetics of the hydrogen development and hydrogen absorption. The cathode side of the samples was galvanostatically cathodically polarized in different electrolyte solutions with and without additions. THe hydrogen atoms diffusing out of the opposite side for iron and α-palladium were oxidized with potentiostatic, sufficiently anodic polarization. The thus registered stationary current is proportional to the hydrogen activity on the cathode side. Test apparatus and conditions are described. The measurements on iron are discussed. (orig./HPOE) [de

  17. Analysis of Gel Permeation Chromatography From Irradiation Copolymer Grafting of Methylmethacrylate on to Natural Rubber

    International Nuclear Information System (INIS)

    Hendrana, Sunit; Purwanto, Indratmoko Hari; Karyaningsih, Ipit; Utama, MargaHerwinarni

    2004-01-01

    Grafting of methyl methacrylate (MMA) onto natural rubber was carried out by γ-irradiation using 60 Co source at dose rate 1 KGy/h and total dose of 5 KGy. Gel permeation chromatography (GPC) was used to analyse the grafting. The GPC's chromatogram, molecular weight and molecular weight distribution data indicate that grafting of MMA onto natural rubber and homo polymerization of MMA are the reaction mostly occurs. Meanwhile, the presence of natural rubber radical with a chain end natural rubber radical affect the PMMA homopolymer occurred

  18. Electrically-controlled permeation of vapors through carbon nanotube network-based membranes

    Czech Academy of Sciences Publication Activity Database

    Slobodian, P.; Říha, Pavel; Olejník, R.

    2018-01-01

    Roč. 17, č. 2 (2018), s. 332-337 ISSN 1536-125X R&D Projects: GA MŠk ED2.1.00/19.0409 Grant - others:Ministerstvo školství, mládeže a tělovýchovy (MŠMT)(CZ) LO1504 Institutional research plan: CEZ:AV0Z20600510 Keywords : carbon nanotubes * electrically controlled membranes * permeation of chemical vapors Impact factor: 2.485, year: 2016

  19. Intestinal surfactant permeation enhancers and their interaction with enterocyte cell membranes in a mucosal explant system

    DEFF Research Database (Denmark)

    Danielsen, E Michael; Hansen, Gert H

    2017-01-01

    Intestinal permeation enhancers (PEs) are agents aimed to improve oral delivery of therapeutic drugs with poor bioavailability. The main permeability barrier for oral delivery is the intestinal epithelium, and PEs act to increase the paracellular and/or transcellular passage of drugs. Transcellular...... for the fluorescent polar tracer lucifer yellow, but surprisingly, they all also blocked both constitutive -and receptor-mediated pathways of endocytosis from the brush border, indicating a complete arrest of apical membrane trafficking. At the ultrastructural level, the PEs caused longitudinal fusion of brush border...

  20. Gel in core carbosomes as novel ophthalmic vehicles with enhanced corneal permeation and residence.

    Science.gov (United States)

    Moustafa, Mona A; El-Refaie, Wessam M; Elnaggar, Yosra S R; Abdallah, Ossama Y

    2018-05-17

    Carbopol is a good bio-adhesive polymer that increases the residence time in the eye. However, the effect of blinking and lacrimation still reduce the amount of polymer and the incorporated drug available for bioadhesion. Gel-core liposomes are advanced systems offering benefits making it a good tool for improved ocular drug delivery and residence time. Incorporation of carbopol in gel-core liposomes and their potential in ocular delivery have not so far been investigated. Fluconazole (FLZ) was selected as a challenging important ocular antifungal suffering from poor corneal permeation and short residence time. In this study, gel-core carbosomes have been elaborated as novel carbopol-based ophthalmic vehicles to solve ocular delivery obstacles of FLZ and to sustain its effect. Full in vitro appraisal was performed considering gel-core structure, entrapment efficiency, particle size and stability of the vesicles as quality attributes. Structure elucidation of the nanocarrier was performed using optical, polarizing and transmission electron microscopy before and after Triton-X100 addition. Ex-vivo ocular permeation and in vivo performance were investigated on male albino rabbits. Optimized formulation (CBS5) showed gel-core structure, nanosize (339.00 ± 5.50 nm) and not defined before (62.00% ± 1.73) entrapment efficiency. Cumulative amount of CBS5 permeated ex-vivo after 6 h, was 2.43 and 3.43 folds higher than that of conventional liposomes and FLZ suspension, respectively. In-vivo corneal permeation of CBS5 showed significantly higher AUC0-24 h (487.12 ± 74.80) compared to that of FLZ suspension (204.34 ± 7.46) with longer residence time in the eye lasts for more than 18 h. In conclusion, novel gel-core carbosomes could successfully be used as a promising delivery system for chronic ocular diseases. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Ethanol from hydrolyzed whey permeate using Saccharomyces cerevisiae in a membrane recycle bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Mehaia, M A [King Saud Univ., Buriedah (Saudi Arabia). Dairy Technology Lab.; Cheryan, M [Illinois Univ., Urbana, IL (USA). Agricultural Bioprocess Lab.

    1990-02-13

    A diauxic fermentation was observed during batch fermentation of enzyme-hydrolyzed whey permeate to ethanol by Saccharomyces cerevisiae. Glucose was consumed before and much faster than galactose. In the continuous membrane recycle bioreactor (MRB), sugar utilization was a function of dilution rate and concentration of sugars. At a cell concentration of 160 kg/m{sup 3}, optimum productivity was 31 kg/(m{sup 3}.h) at ethanol concentration of 65 kg/m{sup 3}. Low levels of acetate (0.05-0.1 M) reduced cell growth during continuous fermentation, but also reduced galactose utilization. (orig.).

  2. Hydrogen Permeation in Cold-Rolled High-Mn Twinning-Induced Plasticity Steels

    Science.gov (United States)

    Han, Do Kyeong; Hwang, A. In; Byeon, Woo Jun; Noh, Seung Jeong; Suh, Dong-Woo

    2017-11-01

    Hydrogen permeation is investigated in cold-rolled Fe-0.6C-18Mn-(1.5Al) alloys. The hydrogen mobility is lower in cold-rolled alloys compared with annealed alloys. Al-containing alloy shows less deceleration of hydrogen mobility compared with the Al-free alloy. This is attributed to the reduced formation of mechanical twins and dislocations. Mechanical twins trap hydrogen strongly but are vulnerable to crack initiation; suppression of these is thought to be a major favorable influence of Al on hydrogen-induced mechanical degradation.

  3. Skeletal keratan sulfate chain molecular weight calibration by high-performance gel-permeation chromatography

    International Nuclear Information System (INIS)

    Dickenson, J.M.; Morris, H.G.; Nieduszynski, I.A.; Huckerby, T.N.

    1990-01-01

    A method has been developed for the molecular sizing of skeletal keratan sulfate chains using an HPLC gel-permeation chromatography system. Keratan sulfate chains and keratanase-derived oligosaccharides were prepared from the nucleus pulposus of bovine intervertebral disc (6-year-old animals). A Bio-Gel TSK 30 XL column eluted in 0.2 M NaCl and at 30 degrees C was calibrated with keratan sulfate oligosaccharides of known size as well as 3H-end-labeled keratan sulfate chains to yield the relationship

  4. Investigation of non-magnetic alloys for the suppression of tritium permeation

    International Nuclear Information System (INIS)

    1980-07-01

    The present work was aimed at identification of alloys which might combine low tritium permeation with other properties desired in fusion reactor vessels, heat exchangers, lithium-handling plumbing and other components likely to contain tritium. These properties include low radiation damage, low magnetic permeability, high temperature strength, and compatibility with potential heat transfer and blanket materials. The work consisted of two tasks: problem definition, and literature search and analysis. Task I was complicated by the incomplete status of fusion reactor development, particularly with respect to selection of coolant and blanket materials and temperatures. The approach taken was to establish a probable range of requirements

  5. Diffusion and solubility coefficients determined by permeation and immersion experiments for organic solvents in HDPE geomembrane.

    Science.gov (United States)

    Chao, Keh-Ping; Wang, Ping; Wang, Ya-Ting

    2007-04-02

    The chemical resistance of eight organic solvents in high density polyethylene (HDPE) geomembrane has been investigated using the ASTM F739 permeation method and the immersion test at different temperatures. The diffusion of the experimental organic solvents in HDPE geomembrane was non-Fickian kinetic, and the solubility coefficients can be consistent with the solubility parameter theory. The diffusion coefficients and solubility coefficients determined by the ASTM F739 method were significantly correlated to the immersion tests (pHDPE as barriers in the field.

  6. Effect of skim milk treated with high hydrostatic pressure on permeate flux and fouling during ultrafiltration.

    Science.gov (United States)

    Leu, Mathilde; Marciniak, Alice; Chamberland, Julien; Pouliot, Yves; Bazinet, Laurent; Doyen, Alain

    2017-09-01

    Ultrafiltration (UF) is largely used in the dairy industry to generate milk and whey protein concentrate for standardization of milk or production of dairy ingredients. Recently, it was demonstrated that high hydrostatic pressure (HHP) extended the shelf life of milk and improved rennet coagulation and cheese yield. Pressurization also modified casein micelle size distribution and promoted aggregation of whey proteins. These changes are likely to affect UF performance. Consequently, this study determined the effect of skim milk pressurization (300 and 600 MPa, 5 min) on UF performance in terms of permeate flux decline and fouling. The effect of HHP on milk proteins was first studied and UF was performed in total recycle mode at different transmembrane pressures to determine optimal UF operational parameters and to evaluate the effect of pressurization on critical and limiting fluxes. Ultrafiltration was also performed in concentration mode at a transmembrane pressure of 345 kPa for 130 or 140 min to evaluate the decline of permeate flux and to determine fouling resistances. It was observed that average casein micelle size decreased by 32 and 38%, whereas β-lactoglobulin denaturation reached 30 and 70% at 300 and 600 MPa, respectively. These results were directly related to UF performance because initial permeate fluxes in total recycle mode decreased by 25% at 300 and 600 MPa compared with nonpressurized milk, critical flux, and limiting flux, which were lower during UF of milk treated with HHP. During UF in concentration mode, initial permeate fluxes were 30% lower at 300 and 600 MPa compared with the control, but the total flux decline was higher for nonpressurized milk (62%) compared with pressure-treated milk (30%). Fouling resistances were similar, whatever the treatment, except at 600 MPa where irreversible fouling was higher. Characterization of the fouling layer showed that caseins and β-lactoglobulin were mainly involved in membrane fouling after UF of

  7. Recycling, inventory and permeation of hydrogen isotopes and helium in the first wall of a thermonuclear fusion reactor

    International Nuclear Information System (INIS)

    Gervasini, G.; Reiter, F.

    1989-01-01

    The work was divided into three parts. The first part, which is theoretical, examines the behaviour of hydrogen in metals. After an introduction on the presence of hydrogen isotopes in fusion reactors, the main phenomena connected with hydrogen-metal interaction are summarised: solubility, diffusivity and trapping in material defects. The metal temperature is highlighted as the main parameter in the description of the phenomena. The second part of the work, also theoretical, concerns the interaction between helium and metals. We have tried as much as possible to show analogies and differences in the comparisons of the behaviour of hydrogen. The main types of damage caused by helium in metallic structures, which are the most important consequence of helium-metal interaction, were summarised. The characteristics of helium were treated in greater depth than those of hydrogen, because the latter are very well known. Also, there is a vast literature on the hydrogen-metal interaction. In the third and last part of the work a model was identified which allows the simulation of the evolution of a system formed from a metal in which hydrogen and helium isotopes have been introduced. A system of algebraic-differential equations was used to study the temporal evolution of the concentrations, the recycling, the inventory and the permeation of tritium and helium considering that these atoms diffuse in the metallic lattice and remain trapped in the vacancies created inside the metal by the bombardment of the neutrons from the fusion reactions. For the numerical simulation a series of data intended to represent the situation inside a thermonuclear reactor as precisely as possible were used for the numerical simulation. Analysis of the system was preceded by the analytical resolution of the steady state equations so that they could be compared with the simulation results

  8. A Bayesian Framework for Remaining Useful Life Estimation

    Data.gov (United States)

    National Aeronautics and Space Administration — The estimation of remaining useful life (RUL) of a faulty component is at the center of system prognostics and health management. It gives operators a potent tool in...

  9. Effect of Enhancers on in vitro and in vivo Skin Permeation and Deposition of S-Methyl-L-Methionine.

    Science.gov (United States)

    Kim, Ki Taek; Kim, Ji Su; Kim, Min-Hwan; Park, Ju-Hwan; Lee, Jae-Young; Lee, WooIn; Min, Kyung Kuk; Song, Min Gyu; Choi, Choon-Young; Kim, Won-Serk; Oh, Hee Kyung; Kim, Dae-Duk

    2017-07-01

    S-methyl- L -methionine (SMM), also known as vitamin U, is commercially available as skin care cosmetic products for its wound healing and photoprotective effects. However, the low skin permeation expected of SMM due to its hydrophilic nature with a log P value of -3.3, has not been thoroughly addressed. The purpose of this study thus was to evaluate the effect of skin permeation enhancers on the skin permeation/deposition of SMM. Among the enhancers tested for the in vitro skin permeation and deposition of SMM, oleic acid showed the most significant enhancing effect. Moreover, the combination of oleic acid and ethanol further enhanced in vitro permeation and deposition of SMM through hairless mouse skin. Furthermore, the combination of oleic acid and ethanol significantly increased the in vivo deposition of SMM in the epidermis/dermis for 12 hr, which was high enough to exert a therapeutic effect. Therefore, based on the in vitro and in vivo studies, the combination of oleic acid and ethanol was shown to be effective in improving the topical skin delivery of SMM, which may be applied in the cosmetic production process for SMM.

  10. Effect of alcohol on skin permeation and metabolism of an ester-type prodrug in Yucatan micropig skin.

    Science.gov (United States)

    Fujii, Makiko; Ohara, Rieko; Matsumi, Azusa; Ohura, Kayoko; Koizumi, Naoya; Imai, Teruko; Watanabe, Yoshiteru

    2017-11-15

    We studied the effect that three alcohols, ethanol (EA), propanol (PA), and isopropanol (IPA), have on the skin permeation of p-hydroxy benzoic acid methyl ester (HBM), a model ester-type prodrug. HBM was applied to Yucatan micropig skin in a saturated phosphate buffered solution with or without 10% alcohol, and HBM and related materials in receptor fluid and skin were determined with HPLC. In the absence of alcohol, p-hydroxy benzoic acid (HBA), a metabolite of HBM, permeated the skin the most. The three alcohols enhanced the penetration of HBM at almost the same extent. The addition of 10% EA or PA to the HBM solution led to trans-esterification into the ethyl ester or propyl ester of HBA, and these esters permeated skin as well as HBA and HBM did. In contrast, the addition of 10% IPA promoted very little trans-esterification. Both hydrolysis and trans-esterification in the skin S9 fraction were inhibited by BNPP, an inhibitor of carboxylesterase (CES). Western blot and native PAGE showed the abundant expression of CES in micropig skin. Both hydrolysis and trans-esterification was simultaneously catalyzed by CES during skin permeation. Our data indicate that the alcohol used in dermal drug preparations should be selected not only for its ability to enhance the solubility and permeation of the drug, but also for the effect on metabolism of the drug in the skin. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. The coupling effect of gas-phase chemistry and surface reactions on oxygen permeation and fuel conversion in ITM reactors

    KAUST Repository

    Hong, Jongsup

    2015-08-01

    © 2015 Elsevier B.V. The effect of the coupling between heterogeneous catalytic reactions supported by an ion transport membrane (ITM) and gas-phase chemistry on fuel conversion and oxygen permeation in ITM reactors is examined. In ITM reactors, thermochemical reactions take place in the gas-phase and on the membrane surface, both of which interact with oxygen permeation. However, this coupling between gas-phase and surface chemistry has not been examined in detail. In this study, a parametric analysis using numerical simulations is conducted to investigate this coupling and its impact on fuel conversion and oxygen permeation rates. A thermochemical model that incorporates heterogeneous chemistry on the membrane surface and detailed chemical kinetics in the gas-phase is used. Results show that fuel conversion and oxygen permeation are strongly influenced by the simultaneous action of both chemistries. It is shown that the coupling somewhat suppresses the gas-phase kinetics and reduces fuel conversion, both attributed to extensive thermal energy transfer towards the membrane which conducts it to the air side and radiates to the reactor walls. The reaction pathway and products, in the form of syngas and C2 hydrocarbons, are also affected. In addition, the operating regimes of ITM reactors in which heterogeneous- or/and homogeneous-phase reactions predominantly contribute to fuel conversion and oxygen permeation are elucidated.

  12. Fabrication, appraisal, and transdermal permeation of sildenafil citrate-loaded nanostructured lipid carriers versus solid lipid nanoparticles

    Science.gov (United States)

    Elnaggar, Yosra SR; El-Massik, Magda A; Abdallah, Ossama Y

    2011-01-01

    Although sildenafil citrate (SC) is used extensively for erectile dysfunction, oral delivery of SC encounters many obstacles. Furthermore, the physicochemical characteristics of this amphoteric drug are challenging for delivery system formulation and transdermal permeation. This article concerns the assessment of the potential of nanomedicine for improving SC delivery and transdermal permeation. SC-loaded nanostructured lipid carriers (NLCs) and solid lipid nanoparticles (SLNs) were fabricated using a modified high-shear homogenization technique. Nanoparticle optimization steps included particle size analysis, entrapment efficiency (EE) determination, freeze-drying and reconstitution, differential scanning calorimetry, in vitro release, stability study and high-performance liquid chromatography analysis. Transdermal permeation of the nanocarriers compared with SC suspension across human skin was assessed using a modified Franz diffusion cell assembly. Results revealed that SLNs and NLCs could be optimized in the nanometric range (180 and 100 nm, respectively) with excellent EE (96.7% and 97.5%, respectively). Nanoparticles have significantly enhanced in vitro release and transdermal permeation of SC compared with its suspensions. Furthermore, transdermal permeation of SC exhibited higher initial release from both SLN and NLC formulations followed by controlled release, with promising implications for faster onset and longer drug duration. Nanomedicines prepared exhibited excellent physical stability for the study period. Solid nanoparticles optimized in this study successfully improved SC characteristics, paving the way for an efficient topical Viagra® product. PMID:22238508

  13. Permeation of sumatriptan succinate across human skin using multiple types of self-dissolving microneedle arrays fabricated from sodium hyaluronate.

    Science.gov (United States)

    Wu, Dan; Katsumi, Hidemasa; Quan, Ying-Shu; Kamiyama, Fumio; Kusamori, Kosuke; Sakane, Toshiyasu; Yamamoto, Akira

    2016-09-01

    Available formulations of sumatriptan succinate (SS) have low bioavailability or are associated with site reactions. We developed various types of self-dissolving microneedle arrays (MNs) fabricated from sodium hyaluronate as a new delivery system for SS and evaluated their skin permeation and irritation in terms of clinical application. In vitro permeation studies with human skin, physicochemical properties (needle length, thickness and density), and penetration enhancers (glycerin, sodium dodecyl sulfate and lauric acid diethanolamide) were investigated. SS-loaded high-density MNs of 800 µm in length were the optimal formulation and met clinical therapeutic requirements. Penetration enhancers did not significantly affect permeation of SS from MNs. Optical coherence tomography images demonstrated that SS-loaded high-density MNs (800 µm) uniformly created drug permeation pathways for the delivery of SS into the skin. SS-loaded high-density MNs induced moderate primary skin irritations in rats, but the skin recovered within 72 h of removal of the MNs. These findings suggest that high-density MNs of 800 µm in length are an effective and promising formulation for transdermal delivery of SS. To our knowledge, this is the first report of SS permeation across human skin using self-dissolving MNs.

  14. Design of a permeator against vacuum for tritium extraction from eutectic lithium-lead in a DCLL DEMO

    Energy Technology Data Exchange (ETDEWEB)

    Garcinuño, Belit, E-mail: belit.garcinuno@ciemat.es [CIEMAT-LNF (Laboratorio Nacional de Fusión), Madrid (Spain); Rapisarda, David [CIEMAT-LNF (Laboratorio Nacional de Fusión), Madrid (Spain); Fernández, Iván [Fundación & Departamento de Ingeniería Energética, UNED, Madrid (Spain); CIEMAT-LNF (Laboratorio Nacional de Fusión), Madrid (Spain); Moreno, Carlos; Palermo, Iole; Ibarra, Ángel [CIEMAT-LNF (Laboratorio Nacional de Fusión), Madrid (Spain)

    2017-04-15

    Highlights: • A conceptual design of a Permeator Against Vacuum is presented. • The efficiency is dependent on geometry and Tritium transport. • The use of different membrane materials is discussed. • A squared PAV with alternated PbLi flowing and vacuum flat ducts is designed. • 80% efficiency of Tritium extraction is accomplished under DCLL-BB requirements. - Abstract: One of the most important issues in future fusion power plants is the extraction of tritium generated in the breeders in order to achieve self-sufficiency. When the breeder is a liquid metal one of the most promising techniques is the Permeation Against Vacuum, whose principle is based on tritium diffusion through a permeable membrane in contact with the liquid metal carrier and its further extraction by a vacuum pump. A conceptual design of permeator has been developed, taking into account the features of a DEMO reactor with a Dual Coolant Lithium Lead (DCLL) breeder blanket. The study is based on the analysis of different membranes and geometries aiming at the overall efficiency (extraction capability) of the device, as well as its compatibility with the breeder material. The permeator is based on a rectangular section multi-channel distribution where the liquid metal channels and vacuum channels are alternated in order to maximize the contact area and therefore to promote tritium transport from the bulk to the walls. The resulting permeator design has an excellent estimated extraction efficiency, of 80%, in a relatively compact device.

  15. Thermal effect of periodical bakeout on tritium inventory in first wall and permeation to coolant in reactor life

    International Nuclear Information System (INIS)

    Nakahara, Katsuhiko

    1989-01-01

    In view of safety, it is very important to control the tritium inventory in first walls and permeation to the coolant. A time-dependent diffusion and temperature calculation code, TPERM, was developed. Using this code, a numerical study on the long term effects of the bakeout temperature on tritium inventory and tritium permeation to the coolant was made. In this study, an FER type first wall (stainless steel) was considered and a cyclic operation (one cycle includes a plasma burn phase and a bakeout phase) was assumed. The results are as follows: (i) There is almost no difference in the tritium inventory in the first wall between the operation with 150 0 C-bakeout and the continuous burning operation (without bakeout). In both cases there is not tritium permeation to the coolant at 5 years' integrated burn time. The 150 0 C-bakeout is effective to release tritium in the surface (to 0.1 mm depth) region on the plasma side, but it is not effective to decrease the tritium inventory over the reactor life. (ii) To decrease the tritium inventory, a bakeout at a temperature higher than 150 0 C is necessary. But a high temperature bakeout causes earlier tritium permeation to the coolant. (iii) From these results it is suggested that the decrease the tritium inventory over the reactor life by bakeout, some form of protection against tritium permeation or a decontamination device in the cooling (or bakeout) system becomes necessary. (orig.)

  16. Robotics to Enable Older Adults to Remain Living at Home

    OpenAIRE

    Pearce, Alan J.; Adair, Brooke; Miller, Kimberly; Ozanne, Elizabeth; Said, Catherine; Santamaria, Nick; Morris, Meg E.

    2012-01-01

    Given the rapidly ageing population, interest is growing in robots to enable older people to remain living at home. We conducted a systematic review and critical evaluation of the scientific literature, from 1990 to the present, on the use of robots in aged care. The key research questions were as follows: (1) what is the range of robotic devices available to enable older people to remain mobile, independent, and safe? and, (2) what is the evidence demonstrating that robotic devices are effec...

  17. Theoretical description of quantum mechanical permeation of graphene membranes by charged hydrogen isotopes

    Science.gov (United States)

    Mazzuca, James W.; Haut, Nathaniel K.

    2018-06-01

    It has been recently shown that in the presence of an applied voltage, hydrogen and deuterium nuclei can be separated from one another using graphene membranes as a nuclear sieve, resulting in a 10-fold enhancement in the concentration of the lighter isotope. While previous studies, both experimental and theoretical, have attributed this effect mostly to differences in vibrational zero point energy (ZPE) of the various isotopes near the membrane surface, we propose that multi-dimensional quantum mechanical tunneling of nuclei through the graphene membrane influences this proton permeation process in a fundamental way. We perform ring polymer molecular dynamics calculations in which we include both ZPE and tunneling effects of various hydrogen isotopes as they permeate the graphene membrane and compute rate constants across a range of temperatures near 300 K. While capturing the experimentally observed separation factor, our calculations indicate that the transverse motion of the various isotopes across the surface of the graphene membrane is an essential part of this sieving mechanism. An understanding of the multi-dimensional quantum mechanical nature of this process could serve to guide the design of other such isotopic enrichment processes for a variety of atomic and molecular species of interest.

  18. Studies of the permeation and diffusion of tritium and hydrogen in TFTR

    International Nuclear Information System (INIS)

    Garber, H.J.

    1975-10-01

    This report documents the main features of studies conducted on the permeation and diffusion of tritium and hydrogen through the stainless steel sections comprising the vacuum vessel of TFTR. The overall conclusion of these studies is that tritium releases to the environment resulting from TFTR operations under normal conditions will be very small, less than one curie per year. A basis is described for predicting the magnitudes of the applicable transport properties for tritium-austenitic stainless steel systems as derived from a survey of the technical literature on tritium transport. The key characteristics of the TFTR vacuum vessel that are involved in the permeation and diffusion calculations are given. Information is given regarding the contemplated plasma scenarios and associated required gas injection quantities. Various issues involved in the bakeout of the vacuum vessel are discussed; focussing principally on the problems associated with in-situ bakeout and related means to reduce outgassing from the TFTR vessel and vacuum pumping system hardware. The anticipated tritium releases are studied considering the diffusion transients

  19. Theoretical description of quantum mechanical permeation of graphene membranes by charged hydrogen isotopes.

    Science.gov (United States)

    Mazzuca, James W; Haut, Nathaniel K

    2018-06-14

    It has been recently shown that in the presence of an applied voltage, hydrogen and deuterium nuclei can be separated from one another using graphene membranes as a nuclear sieve, resulting in a 10-fold enhancement in the concentration of the lighter isotope. While previous studies, both experimental and theoretical, have attributed this effect mostly to differences in vibrational zero point energy (ZPE) of the various isotopes near the membrane surface, we propose that multi-dimensional quantum mechanical tunneling of nuclei through the graphene membrane influences this proton permeation process in a fundamental way. We perform ring polymer molecular dynamics calculations in which we include both ZPE and tunneling effects of various hydrogen isotopes as they permeate the graphene membrane and compute rate constants across a range of temperatures near 300 K. While capturing the experimentally observed separation factor, our calculations indicate that the transverse motion of the various isotopes across the surface of the graphene membrane is an essential part of this sieving mechanism. An understanding of the multi-dimensional quantum mechanical nature of this process could serve to guide the design of other such isotopic enrichment processes for a variety of atomic and molecular species of interest.

  20. Exocellular extract of Fusarium oxysporum, fungus free, is able to permeate and act selectively in skin.

    Science.gov (United States)

    Sibin Melo, Katia C; Correia, Marcelo H; Svidzinski, Terezinha I E; Hernandes, Luzmarina

    2018-05-01

    The skin is an important gateway for Fusarium infection in humans. Our hypothesis is that metabolites produced by Fusarium oxysporum should change the barrier structure to permeate the skin. Male Wistar rats received a topical application of a solution (0.05 mg/mL) of Fusarium metabolites. The animals were euthanized 3, 6, 12, 24 h after and the skin was processed for immunostaining by laminin and E-cadherin to investigate whether the Fusarium metabolites can break the barrier of healthy skin. Other techniques were employed: H&E to study the morphology; metalloproteinase-9 (MMP-9), TUNEL, and PCNA immunostaining to evaluate the inflammation, cell death, and proliferation, respectively. There was an inflammatory response mainly centered in the dermis. Qualitatively, the skin of the experimental group showed reduced E-cadherin and laminin immunostaining at 3, 12, and 24 h. Higher intensity staining by TUNEL at 3 h, and PCNA at 6, 12, and 24 h. There was intense MMP-9 activity at 6, 12, and 24 h. None of analyses revealed any changes in the epidermis. It was concluded that the fraction was able to permeate the skin and act selectively in dermis, inducing inflammatory response, increasing MMP-9 immunostaining, inducing apoptosis, and reducing E-cadherin and laminin immunostaining. © 2018 APMIS. Published by John Wiley & Sons Ltd.