WorldWideScience

Sample records for internal diffusion resistances

  1. Photosynthesis of cotton leaves under a range of environmental conditions in relation to internal and external diffusive resistances

    Energy Technology Data Exchange (ETDEWEB)

    Bierhuizen, J F; Slatyer, R O

    1964-01-01

    Experiments have been described in which photosynthesis of cotton leaves enclosed in a leaf chamber was measured under various conditions of light intensity (1000-6000 f.c., corresponding to 3 x 8 x 10/sup 4/-22 x 5 10/sup 4/ erg cm/sup -2/ sec/sup -1/), CO/sub 2/ concentration (200-2000 p.p.m.), temperature (30-40/sup 0/C), relative humidity (40-80%), and windspeed (0 x 6-3 x 1) cm sec/sup -1/). The plants were well watered in order to minimize water stress. The experiments conducted so far indicate that, with the conditions employed, CO/sub 2/ and light were the main factors limiting photosynthesis. At all light intensities there was an almost linear response to CO/sub 2/ concentration up to values of 600-800 p.p.m. CO/sub 2/ above which there appeared to be effective CO/sub 2/ saturation. The response to light was of particular interest. It appeared that, under limiting CO/sub 2/ conditions, an increase in light intensity increased photosynthesis not only by decreasing stomatal resistance, hence resulting in increased CO/sub 2/ diffusion through the stomata, but also by increasing the liquid phase permeability of the mesophyll cell walls to CO/sub 2/ transport. Total resistance in the diffusion pathway, the sum of r', averaged 22 sec cm/sup -1/ at 1000 f.c. for a range of windspeed, CO/sub 2/, temperature, and humidity conditions, and declined progressively to about 7 sec cm/sup -1/ at 6000 f.c. The contribution of the gaseous diffusion resistances (r'/sub a/ + r'/sub al/) decreased, at the same time, from about 8 to 4 sec cm/sup -1/. 26 references, 5 figures, 1 table.

  2. The Internal Resistance of Supercapacitors

    Science.gov (United States)

    Costa, G. G. G.; Pietronero, R. C.; Catunda, T.

    2012-01-01

    In this paper we study the transient behaviour of RC circuits with supercapacitors, varying R between 1 and 100 [omega]. We demonstrate that supercapacitors behave as ideal capacitors in series with an internal resistance (r [similar to] 8 [omega] for C = 0.2 F, 5.5 V). This result is important to optimize the demonstration of RC circuits using a…

  3. Forecasting the international diffusion of innovations: An adaptive estimation approach

    NARCIS (Netherlands)

    Y.M. van Everdingen (Yvonne); W.B. Aghina (Wouter)

    2003-01-01

    textabstractWe introduce an international, adaptive diffusion model that can be used to forecast the cross-national diffusion of an innovation at early stages of the diffusion curve. We model the mutual influence between the diffusion processes in the different social systems (countries) by mixing

  4. Statistical models of a gas diffusion electrode: II. Current resistent

    Energy Technology Data Exchange (ETDEWEB)

    Proksch, D B; Winsel, O W

    1965-07-01

    The authors describe an apparatus for measuring the flow resistance of gas diffusion electrodes which is a mechanical analog of the Wheatstone bridge for measuring electric resistance. The flow resistance of a circular DSK electrode sheet, consisting of two covering layers and a working layer between them, was measured as a function of the gas pressure. While the pressure first was increased and then decreased, a hysteresis occurred, which is discussed and explained by a statistical model of a porous electrode.

  5. Modifying glass surfaces via internal diffusion

    DEFF Research Database (Denmark)

    Smedskjaer, M.M.; Yue, Y.Z.; Deubener, J.

    2010-01-01

    leads to outward diffusion (OD) of divalent cations (primarily Mg2+), i.e., diffusion from the interior of the glass to the surface, and thereby, to formation of an oxide surface nano-layer. in contrast, when the glasses are heat-treated in H-2/N-2 gas containing 10 vol.% H-2, reduction of Fe3+ to Fe2...... on some properties such as hardness, chemical durability, and surface wettability....

  6. Diffusivity and electrical resistivity measurements in rock matrix around fractures

    International Nuclear Information System (INIS)

    Kumpulainen, H.; Uusheimo, K.

    1989-12-01

    Microfracturing of rock matrix around permeable fractures was studied experimentally from drill core samples around major fractures. The methods used were diffusion measurements using a 36 Cl-tracer and electrical resistivity measurements. Rock samples were from the Romuvaara investigation site, the granite specimen around a partially filled carbonate fracture (KR4/333 m) and gneiss specimen around a slickenside fracture (KR1/645 m). A consistent difference of one to two orders of magnitude in the levels of the methods with regard to the effective diffusion coefficients for Cl - -ion was found, the electrical resistivity measurement giving higher values. On the basis of the diffusion measurements the diffusion porosities could be calculated but these remained one to two orders of magnitude lower than that expected for granitic rocks using the water saturation method. A possible reason for these differences could have been the low, in some cases 0.004 M NaC1-concentration in the diffusion experiments vs. the 1 M NaCl-concentration used in the electrical resistivity measurements. Due to the small number of specimens and cross sectional areas of only 2 cm 2 , rock inhomogeneity effects were significant making the interpretation of the results somewhat troublesome. Porosities on fracture surfaces seemed to be higher than in the deeper, more intact rock matrix

  7. Internal Diffusion-Controlled Enzyme Reaction: The Acetylcholinesterase Kinetics.

    Science.gov (United States)

    Lee, Sangyun; Kim, Ji-Hyun; Lee, Sangyoub

    2012-02-14

    Acetylcholinesterase is an enzyme with a very high turnover rate; it quenches the neurotransmitter, acetylcholine, at the synapse. We have investigated the kinetics of the enzyme reaction by calculating the diffusion rate of the substrate molecule along an active site channel inside the enzyme from atomic-level molecular dynamics simulations. In contrast to the previous works, we have found that the internal substrate diffusion is the determinant of the acetylcholinesterase kinetics in the low substrate concentration limit. Our estimate of the overall bimolecular reaction rate constant for the enzyme is in good agreement with the experimental data. In addition, the present calculation provides a reasonable explanation for the effects of the ionic strength of solution and the mutation of surface residues of the enzyme. The study suggests that internal diffusion of the substrate could be a key factor in understanding the kinetics of enzymes of similar characteristics.

  8. Investigating international new product diffusion speed: A semiparametric approach

    KAUST Repository

    Hartman, Brian M.

    2012-06-01

    Global marketing managers are interested in understanding the speed of the new product diffusion process and how the speed has changed in our ever more technologically advanced and global marketplace. Understanding the process allows firms to forecast the expected rate of return on their new products and develop effective marketing strategies. The most recent major study on this topic [Marketing Science 21 (2002) 97-114] investigated new product diffusions in the United States.We expand upon that study in three important ways. (1) Van den Bulte notes that a similar study is needed in the international context, especially in developing countries. Our study covers four new product diffusions across 31 developed and developing nations from 1980-2004. Our sample accounts for about 80% of the global economic output and 60% of the global population, allowing us to examine more general phenomena. (2) His model contains the implicit assumption that the diffusion speed parameter is constant throughout the diffusion life cycle of a product. Recognizing the likely effects on the speed parameter of recent changes in the marketplace, we model the parameter as a semiparametric function, allowing it the flexibility to change over time. (3) We perform a variable selection to determine that the number of internet users and the consumer price index are strongly associated with the speed of diffusion. © Institute of Mathematical Statistics, 2012.

  9. Resistive internal helical mode near the instability threshold

    International Nuclear Information System (INIS)

    Gal'vao, R.M.; Sakanaka, P.Kh.

    1979-01-01

    The behaviour of a resistive internal helical mode is examined on condition that its resonance surface is located on a magnetic axis, i.e., at the stability boundary. In this case the mode increment is shown to have the scale (tausub(R)tausub(H))sup(1/2), where: 1) tausub(H)=rsub(o)/Vsub(THETA), Vsub(THETA) = Bsub(THETA)(q'rsub(o)/q)/(4πrho)sup(1/2), rho is a matter density, q'=dq/dr and Vsub(THETA) is calculated at r=rsub(o)) (rsub(o) is a radium on which q(rsub(o)=1), 2)tausub(R)=4πrsub(o)sup(2)/etacsup(2) - time of field diffusion (eta-plasma resistance)

  10. Diffusion barrier coatings for high temperature corrosion resistance of advanced carbon/carbon composites

    International Nuclear Information System (INIS)

    Singh Raman, K.S.

    2000-01-01

    Carbon possesses an excellent combination of mechanical and thermal properties, viz., excellent creep resistance at temperatures up to 2400 deg C in non-oxidizing environment and a low thermal expansion coefficient. These properties make carbon a potential material for very high temperature applications. However, the use of carbon materials at high temperatures is considerably restricted due to their extremely poor oxidation resistance at temperatures above 400 deg C. The obvious choice for improving high temperature oxidation resistance of such materials is a suitable diffusion barrier coating. This paper presents an overview of recent developments in advanced diffusion- and thermal-barrier coatings for ceramic composites, with particular reference to C/C composites. The paper discusses the development of multiphase and multi-component ceramic coatings, and recent investigations on the oxidation resistance of the coated C/C composites. The paper also discusses the cases of innovative engineering solutions for traditional problems with the ceramic coatings, and the scope of intelligent processing in developing coatings for the C/C composites. Copyright (2000) AD-TECH - International Foundation for the Advancement of Technology Ltd

  11. Control strategy on the double-diffusive convection in a nanofluid layer with internal heat generation

    Science.gov (United States)

    Mokhtar, N. F. M.; Khalid, I. K.; Siri, Z.; Ibrahim, Z. B.; Gani, S. S. A.

    2017-10-01

    The influences of feedback control and internal heat source on the onset of Rayleigh-Bénard convection in a horizontal nanofluid layer is studied analytically due to Soret and Dufour parameters. The confining boundaries of the nanofluid layer (bottom boundary-top boundary) are assumed to be free-free, rigid-free, and rigid-rigid, with a source of heat from below. Linear stability theory is applied, and the eigenvalue solution is obtained numerically using the Galerkin technique. Focusing on the stationary convection, it is shown that there is a positive thermal resistance in the presence of feedback control on the onset of double-diffusive convection, while there is a positive thermal efficiency in the existence of internal heat generation. The possibilities of suppress or augment of the Rayleigh-Bénard convection in a nanofluid layer are also discussed in detail.

  12. Development of lithium diffused radiation resistant solar cells, part 2

    Science.gov (United States)

    Payne, P. R.; Somberg, H.

    1971-01-01

    The work performed to investigate the effect of various process parameters on the performance of lithium doped P/N solar cells is described. Effort was concentrated in four main areas: (1) the starting material, (2) the boron diffusion, (3) the lithium diffusion, and (4) the contact system. Investigation of starting material primarily involved comparison of crucible grown silicon (high oxygen content) and Lopex silicon (low oxygen content). In addition, the effect of varying growing parameters of crucible grown silicon on lithium cell output was also examined. The objective of the boron diffusion studies was to obtain a diffusion process which produced high efficiency cells with minimal silicon stressing and could be scaled up to process 100 or more cells per diffusion. Contact studies included investigating sintering of the TiAg contacts and evaluation of the contact integrity.

  13. Reducing of internal resistance lithium ion battery using glucose addition

    Science.gov (United States)

    Salim, Andri Pratama; Hafidlullah, Noor; Purwanto, Agus

    2016-02-01

    There are two indicators of battery performance, i.e : capacity and the internal resistance of battery. In this research, the affect of glucose addition to decrease the internal resistance of lithium battery was investigated. The ratio of glucose addition were varied at weight ratio 1%, 3%, and 5% and one mixtures without glucose addition. Lithium ferri phosphate (LiFePO4), polyvinylidene fluoride (PVDF), acetylene black (AB) and glucose were materials that used in this study. Both of mixtures were mixed in the vacuum mixer until became homogeneous. The slurry was coated on an aluminium foil sheet and the coated thickness was 200 µm. The performance of battery lithium was examined by Eight Channel Battery Analyzer and the Internal resistance was examined by Internal Resistance of Battery Meter. The result from all analyzer were showed that the internal resistance reduced as well as the battery capacity. The best internal resistance value is owned by mixtures with 3wt% ratio glucose addition. It has an internal resistance value about 64 miliohm.

  14. Reducing of internal resistance lithium ion battery using glucose addition

    International Nuclear Information System (INIS)

    Salim, Andri Pratama; Hafidlullah, Noor; Purwanto, Agus

    2016-01-01

    There are two indicators of battery performance, i.e : capacity and the internal resistance of battery. In this research, the affect of glucose addition to decrease the internal resistance of lithium battery was investigated. The ratio of glucose addition were varied at weight ratio 1%, 3%, and 5% and one mixtures without glucose addition. Lithium ferri phosphate (LiFePO 4 ), polyvinylidene fluoride (PVDF), acetylene black (AB) and glucose were materials that used in this study. Both of mixtures were mixed in the vacuum mixer until became homogeneous. The slurry was coated on an aluminium foil sheet and the coated thickness was 200 µm. The performance of battery lithium was examined by Eight Channel Battery Analyzer and the Internal resistance was examined by Internal Resistance of Battery Meter. The result from all analyzer were showed that the internal resistance reduced as well as the battery capacity. The best internal resistance value is owned by mixtures with 3wt% ratio glucose addition. It has an internal resistance value about 64 miliohm

  15. Reducing of internal resistance lithium ion battery using glucose addition

    Energy Technology Data Exchange (ETDEWEB)

    Salim, Andri Pratama; Hafidlullah, Noor; Purwanto, Agus, E-mail: aguspurw@gmail.com [Research Group of Battery & Advanced Material, Department of Chemical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A Kentingan, Surakarta Indonesia 57126 (Indonesia)

    2016-02-08

    There are two indicators of battery performance, i.e : capacity and the internal resistance of battery. In this research, the affect of glucose addition to decrease the internal resistance of lithium battery was investigated. The ratio of glucose addition were varied at weight ratio 1%, 3%, and 5% and one mixtures without glucose addition. Lithium ferri phosphate (LiFePO{sub 4}), polyvinylidene fluoride (PVDF), acetylene black (AB) and glucose were materials that used in this study. Both of mixtures were mixed in the vacuum mixer until became homogeneous. The slurry was coated on an aluminium foil sheet and the coated thickness was 200 µm. The performance of battery lithium was examined by Eight Channel Battery Analyzer and the Internal resistance was examined by Internal Resistance of Battery Meter. The result from all analyzer were showed that the internal resistance reduced as well as the battery capacity. The best internal resistance value is owned by mixtures with 3wt% ratio glucose addition. It has an internal resistance value about 64 miliohm.

  16. More nutritious bananas resist disease | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-10-28

    Oct 28, 2010 ... English · Français ... By inserting resistant varieties (like FHIA-17 and FHIA-23) between traditional, susceptible plants, we 'trap' ... This has a direct impact on food security by restoring the productivity of the traditional varieties.

  17. Investigating international new product diffusion speed: A semiparametric approach

    KAUST Repository

    Hartman, Brian M.; Mallick, Bani K.; Talukdar, Debabrata

    2012-01-01

    Global marketing managers are interested in understanding the speed of the new product diffusion process and how the speed has changed in our ever more technologically advanced and global marketplace. Understanding the process allows firms

  18. Bulk and contact resistances of gas diffusion layers in proton exchange membrane fuel cells

    Science.gov (United States)

    Ye, Donghao; Gauthier, Eric; Benziger, Jay B.; Pan, Mu

    2014-06-01

    A multi-electrode probe is employed to distinguish the bulk and contact resistances of the catalyst layer (CL) and the gas diffusion layer (GDL) with the bipolar plate (BPP). Resistances are compared for Vulcan carbon catalyst layers (CL), carbon paper and carbon cloth GDL materials, and GDLs with microporous layers (MPL). The Vulcan carbon catalyst layer bulk resistance is 100 times greater than the bulk resistance of carbon paper GDL (Toray TG-H-120). Carbon cloth (CCWP) has bulk and contact resistances twice those of carbon paper. Compression of the GDL decreases the GDL contact resistance, but has little effect on the bulk resistance. Treatment of the GDL with polytetrafluoroethylene (PTFE) increases the contact resistance, but has little effect on the bulk resistance. A microporous layer (MPL) added to the GDL decreases the contact resistance, but has little effect on the bulk resistance. An equivalent circuit model shows that for channels less than 1 mm wide the contact resistance is the major source of electronic resistance and is about 10% of the total ohmic resistance associated with the membrane electrode assembly.

  19. Diffusion and perfusion MRI for the localisation of epileptogenic foci in drug-resistant epilepsy

    International Nuclear Information System (INIS)

    Heiniger, P.; El-Koussy, M.; Kiefer, C.; Oswald, H.; Schroth, G.; Schindler, K.; Donati, F.; Loevblad, K.O.; Wissmeyer, M.; Mariani, L.; Weder, B.

    2002-01-01

    Drug-resistant epilepsy is an important clinical challenge, both diagnostically and therapeutically. More and more surgical options are being considered, but precise presurgical assessment is necessary. We prospectively studied eight patients with drug-resistant epilepsy, who underwent clinical examination, single photon emission computed tomography (SPECT) and interictal MRI, including diffusion- and perfusion-weighted echoplanar sequences. Lesions suspected on SPECT of being epileptogenic showed mild hypoperfusion, while the diffusion-weighted MRI (DWI) revealed increased apparent diffusion coefficients relative to the other side. However, these abnormalities were not visible on the corresponding maps. We showed that DWI and perfusion-weighted MRI could be used confirm the characteristics and site of an epileptogenic area in patients with drug-resistant epilepsy. (orig.)

  20. Diffusion

    International Nuclear Information System (INIS)

    Kubaschewski, O.

    1983-01-01

    The diffusion rate values of titanium, its compounds and alloys are summarized and tabulated. The individual chemical diffusion coefficients and self-diffusion coefficients of certain isotopes are given. Experimental methods are listed which were used for the determination of diffusion coefficients. Some values have been taken over from other studies. Also given are graphs showing the temperature dependences of diffusion and changes in the diffusion coefficient with concentration changes

  1. Global energy governance: trade, infrastructure, and the diffusion of international organizations

    OpenAIRE

    Leonardo Baccini; Veronica Lenzi; Paul W. Thurner

    2013-01-01

    Why do states choose to join and form international governmental organizations (IGOs) that regulate energy policy? In this article we make three specific contributions to the literature on international cooperation and diffusion. First, we show that countries form and join energy IGOs in response to memberships previously gained by direct competitors among oil and gas producers and consumers. Moreover, we demonstrate that energy IGOs diffuse among countries that share oil and gas pipelines. F...

  2. Electric fields, weighting fields, signals and charge diffusion in detectors including resistive materials

    CERN Document Server

    Riegler, Werner

    2016-11-07

    In this report we discuss static and time dependent electric fields in detector geometries with an arbitrary number of parallel layers of a given permittivity and weak conductivity. We derive the Green's functions i.e. the field of a point charge, as well as the weighting fields for readout pads and readout strips in these geometries. The effect of 'bulk' resistivity on electric fields and signals is investigated. The spreading of charge on thin resistive layers is also discussed in detail, and the conditions for allowing the effect to be described by the diffusion equation is discussed. We apply the results to derive fields and induced signals in Resistive Plate Chambers, Micromega detectors including resistive layers for charge spreading and discharge protection as well as detectors using resistive charge division readout like the MicroCAT detector. We also discuss in detail how resistive layers affect signal shapes and increase crosstalk between readout electrodes.

  3. Electric fields, weighting fields, signals and charge diffusion in detectors including resistive materials

    International Nuclear Information System (INIS)

    Riegler, W.

    2016-01-01

    In this report we discuss static and time dependent electric fields in detector geometries with an arbitrary number of parallel layers of a given permittivity and weak conductivity. We derive the Green's functions i.e. the field of a point charge, as well as the weighting fields for readout pads and readout strips in these geometries. The effect of 'bulk' resistivity on electric fields and signals is investigated. The spreading of charge on thin resistive layers is also discussed in detail, and the conditions for allowing the effect to be described by the diffusion equation is discussed. We apply the results to derive fields and induced signals in Resistive Plate Chambers, MICROMEGAS detectors including resistive layers for charge spreading and discharge protection as well as detectors using resistive charge division readout like the MicroCAT detector. We also discuss in detail how resistive layers affect signal shapes and increase crosstalk between readout electrodes.

  4. Ion Permeability of Artificial Membranes Evaluated by Diffusion Potential and Electrical Resistance Measurements

    Science.gov (United States)

    Shlyonsky, Vadim

    2013-01-01

    In the present article, a novel model of artificial membranes that provides efficient assistance in teaching the origins of diffusion potentials is proposed. These membranes are made of polycarbonate filters fixed to 12-mm plastic rings and then saturated with a mixture of creosol and "n"-decane. The electrical resistance and potential…

  5. Influence of Drought on Mesophyll Resistance to CO2 Diffusion and its Impact on Water-Use Efficiency in Trees

    Science.gov (United States)

    Guo, J.; Beverly, D.; Cook, C.; Ewers, B. E.; Williams, D. G.

    2015-12-01

    The resistance to CO2 diffusion inside leaves (mesophyll resistance; rm) during photosynthesis is often comparable in magnitude to stomatal diffusion resistance, and varies among species and across environmental conditions. Consequently, photosynthesis is strongly limited by rm at low internal CO2 partial pressures, such that its variation may determine patterns of leaf water-use efficiency (WUE). Reduction in stomatal conductance with drought typically increases WUE, but also decreases photosynthesis. In theory, the decrease in photosynthesis could be countered by reduction in rm while maintaining high WUE. It is still uncertain how drought-related changes in rm affect short- and long-term WUE strategies of different tree species. We conducted field observations of instantaneous WUE and 13C discrimination in two dominant conifer species (Pinus contorta and Picea engelmannii) in SE Wyoming over the seasonal dry-down period in the summer of 2015. rm was examined by on-line 13C discrimination using isotope laser spectroscopy. Controlled environment studies on three conifer species (P. contorta, P. engelmannii, and Abies lasiocarpa) and one angiosperm (Populus tremuloides) are in progress. We hypothesize that the plasticity of rm in response to drought accounts for significant adjustments in photosynthetic capacity and WUE. Needle leaf conifers are known to have relatively high rm, and we expect them to show greater improvements in photosynthesis and WUE when rm is decreased compared to angiosperm tree species.

  6. Improving the Corrosion Resistance of Biodegradable Magnesium Alloys by Diffusion Coating Process

    Science.gov (United States)

    Levy, Galit Katarivas; Aghion, Eli

    Magnesium alloys suffer from accelerated corrosion in physiological environment and hence their use as a structural material for biodegradable implants is limited. The present study focuses on a diffusion coating treatment that amplifies the beneficial effect of Neodymium on the corrosion resistance of magnesium alloys. The diffusion coating layer was obtained by applying 1 µm Nd coating on EW10X04 magnesium alloy using Electron-gun evaporator and PVD process. The coated alloy was heat treated at 350°C for 3 hours in a protective atmosphere of N2+0.2%SF6. The micro structure characteristics were evaluated by SEM, XRD, and XPS; the corrosion resistance was examined by potentiodynamic polarization and EIS analysis. The corrosion resistance of the diffusion coated alloy was significantly improved compared to the uncoated material. This was related to: (i) formation of Nd2O3 in the outer scale, (ii) integration of Nd in the MgO oxide layer, and (iii) formation of secondary phase Mg41Nd5 along the grain boundaries of α-Mg.

  7. Ontario Interns Fight Back: Modes of Resistance Against Unpaid Internships

    Directory of Open Access Journals (Sweden)

    William Webb

    2015-09-01

    Full Text Available In this article I report on three ways that interns and those sympathetic to their plight are opposing unpaid internships, focusing on the Canadian province of Ontario as a case. First, I analyze the ways that interns engage in social activism to raise awareness about problems with unpaid internships. Second, I examine several lawsuits that interns have waged against companies in an attempt to secure back pay. Third, I analyze the Ontario Ministry of Labour’s response to the growing concerns surrounding unpaid internships, and recent proposals that aim to strengthen governmental regulations. Arguing that possibilities for change have arisen largely due to the efforts of interns themselves, I conclude each section by noting some of the strengths and limitations afforded by each type of resistance.

  8. Universal linear-temperature resistivity: possible quantum diffusion transport in strongly correlated superconductors.

    Science.gov (United States)

    Hu, Tao; Liu, Yinshang; Xiao, Hong; Mu, Gang; Yang, Yi-Feng

    2017-08-25

    The strongly correlated electron fluids in high temperature cuprate superconductors demonstrate an anomalous linear temperature (T) dependent resistivity behavior, which persists to a wide temperature range without exhibiting saturation. As cooling down, those electron fluids lose the resistivity and condense into the superfluid. However, the origin of the linear-T resistivity behavior and its relationship to the strongly correlated superconductivity remain a mystery. Here we report a universal relation [Formula: see text], which bridges the slope of the linear-T-dependent resistivity (dρ/dT) to the London penetration depth λ L at zero temperature among cuprate superconductor Bi 2 Sr 2 CaCu 2 O 8+δ and heavy fermion superconductors CeCoIn 5 , where μ 0 is vacuum permeability, k B is the Boltzmann constant and ħ is the reduced Planck constant. We extend this scaling relation to different systems and found that it holds for other cuprate, pnictide and heavy fermion superconductors as well, regardless of the significant differences in the strength of electronic correlations, transport directions, and doping levels. Our analysis suggests that the scaling relation in strongly correlated superconductors could be described as a hydrodynamic diffusive transport, with the diffusion coefficient (D) approaching the quantum limit D ~ ħ/m*, where m* is the quasi-particle effective mass.

  9. On axisymmetric resistive magnetohydrodynamic equilibria with flow free of Pfirsch-Schlueter diffusion

    International Nuclear Information System (INIS)

    Throumoulopoulos, G.N.; Tasso, H.

    2003-01-01

    The equilibrium of an axisymmetric magnetically confined plasma with anisotropic resistivity and incompressible flows parallel to the magnetic field is investigated within the framework of the magnetohydrodynamic (MHD) theory by keeping the convective flow term in the momentum equation. It turns out that the stationary states are determined by a second-order elliptic partial differential equation for the poloidal magnetic flux function ψ along with a decoupled Bernoulli equation for the pressure identical in form with the respective ideal MHD equations; equilibrium consistent expressions for the resistivities η (parallel) and η (perpendicular) parallel and perpendicular to the magnetic field are also derived from Ohm's and Faraday's laws. Unlike in the case of stationary states with isotropic resistivity and parallel flows [G. N. Throumoulopoulos and H. Tasso, J. Plasma Phys. 64, 601 (2000)] the equilibrium is compatible with nonvanishing poloidal current densities. Also, although exactly Spitzer resistivities either η (parallel) (ψ) or η (perpendicular) (ψ) are not allowed, exact solutions with vanishing poloidal electric fields can be constructed with η (parallel) and η (perpendicular) profiles compatible with roughly collisional resistivity profiles, i.e., profiles having a minimum close to the magnetic axis, taking very large values on the boundary and such that η (perpendicular) >η (parallel) . For equilibria with vanishing flows satisfying the relation (dP/dψ)(dI 2 /dψ)>0, where P and I are the pressure and the poloidal current functions, the difference η (perpendicular) -η (parallel) for the reversed-field pinch scaling, B p ≅B t , is nearly two times larger than that for the tokamak scaling, B p ≅0.1B t (B p and B t are the poloidal and toroidal magnetic-field components). The particular resistive equilibrium solutions obtained in the present work, inherently free of - but not inconsistent with - Pfirsch-Schlueter diffusion, indicate that

  10. On axisymmetric resistive magnetohydrodynamic equilibria with flow free of Pfirsch-Schlüter diffusion

    Science.gov (United States)

    Throumoulopoulos, G. N.; Tasso, H.

    2003-06-01

    The equilibrium of an axisymmetric magnetically confined plasma with anisotropic resistivity and incompressible flows parallel to the magnetic field is investigated within the framework of the magnetohydrodynamic (MHD) theory by keeping the convective flow term in the momentum equation. It turns out that the stationary states are determined by a second-order elliptic partial differential equation for the poloidal magnetic flux function ψ along with a decoupled Bernoulli equation for the pressure identical in form with the respective ideal MHD equations; equilibrium consistent expressions for the resistivities η∥ and η⊥ parallel and perpendicular to the magnetic field are also derived from Ohm's and Faraday's laws. Unlike in the case of stationary states with isotropic resistivity and parallel flows [G. N. Throumoulopoulos and H. Tasso, J. Plasma Phys. 64, 601 (2000)] the equilibrium is compatible with nonvanishing poloidal current densities. Also, although exactly Spitzer resistivities either η∥(ψ) or η⊥(ψ) are not allowed, exact solutions with vanishing poloidal electric fields can be constructed with η∥ and η⊥ profiles compatible with roughly collisional resistivity profiles, i.e., profiles having a minimum close to the magnetic axis, taking very large values on the boundary and such that η⊥>η∥. For equilibria with vanishing flows satisfying the relation (dP/dψ)(dI2/dψ)>0, where P and I are the pressure and the poloidal current functions, the difference η⊥-η∥ for the reversed-field pinch scaling, Bp≈Bt, is nearly two times larger than that for the tokamak scaling, Bp≈0.1Bt (Bp and Bt are the poloidal and toroidal magnetic-field components). The particular resistive equilibrium solutions obtained in the present work, inherently free of—but not inconsistent with—Pfirsch-Schlüter diffusion, indicate that parallel flows might result in a reduction of the diffusion observed in magnetically confined plasmas.

  11. Hybrid diffusive/PVD treatments to improve the tribological resistance of Ti-6Al-4V.

    Science.gov (United States)

    Marin, E; Offoiach, R; Lanzutti, A; Regis, M; Fusi, S; Fedrizzi, L

    2014-01-01

    Titanium alloys are nowadays used for a wide range of biomedical applications thanks to their combination of high mechanical resistance, high corrosion resistance and biocompatibility. Nevertheless, the applicability of titanium alloys is sometimes limited due to their low microhardness and tribological resistance. Thus the titanium alloys cannot be successfully applied to prosthetic joint couplings. A wide range of surface treatments, in particular PVD coatings such as CrN and TiN, have been used in order to improve the tribological behaviour of titanium alloys. However, the low microhardness of the titanium substrate often results in coating failure due to cracks and delamination. For this reason, hybrid technologies based on diffusive treatments and subsequent PVD coatings may improve the overall coating resistance. In this work, conventional PVD coatings of CrN or TiCN, deposited on Titanium Grade 5, were characterized and then combined with a standard thermal diffusive nitriding treatment in order to improve the tribological resistance of the titanium alloys and avoid coating delamination. The different treatments were studied by means of scanning electron microscopy both on the sample surface and in cross-section. In-depth composition profiles were obtained using glow discharge optical emission spectrometry (GDOES) and localized energy dispersive X-ray diffraction on linear scan-lines. The microhardness and adhesion properties of the different treatments were evaluated using Vickers microhardness tests at different load conditions. The indentations were observed by means of SEM in order to evaluate delaminated areas and the crack's shape and density. The tribological behaviour of the different treatments was tested in dry conditions and in solution, in alternate pin-on-flat configuration, with a frequency of 0.5 Hz. After testing, the surface was investigated by means of stylus profilometry and SEM both on the surface and in cross-section. The standalone PVD

  12. Circumvention of resistance to photodynamic therapy in doxorubicin-resistant sarcoma by photochemical internalization of gelonin.

    Science.gov (United States)

    Olsen, Cathrine Elisabeth; Berg, Kristian; Selbo, Pål Kristian; Weyergang, Anette

    2013-12-01

    A wide range of anti-cancer therapies have been shown to induce resistance upon repetitive treatment and such adapted resistance may also cause cross-resistance to other treatment modalities. We here show that MES-SA/Dx5 cells with adapted resistance to doxorubicin (DOX) are cross-resistant to photodynamic therapy (PDT). A DOX-induced increased expression of the reactive oxygen species (ROS)-scavenging proteins glutathione peroxidase (GPx) 1 and GPx4 in MES-SA/Dx5 cells was indicated as the mechanism of resistance to PDT in line with the reduction in PDT-generated ROS observed in this cell line. ROS-induced p38 activation was, in addition, shown to be reduced to one-third of the signal of the parental MES-SA cells 2h after PDT, and addition of the p38 inhibitor SB203580 confirmed p38 activation as a death signal after PDT in the MES-SA cells. The MES-SA/Dx5 cells were also cross-resistant to ionizing radiation in agreement with the increased GPx1 and GPx4 expression. Surprisingly, PDT-induced endo/lysosomal release of the ribosome-inactivating protein gelonin (photochemical internalization (PCI)) was more effective in the PDT-resistant MES-SA/Dx5 cells, as measured by synergy calculations in both cell lines. Analysis of death-inducing signaling indicated a low activation of caspase-3 and a strong PARP I cleavage after PDT and PCI in both cell lines. The PARP I activation was, however, stronger after PCI than after PDT in the MES-SA cells, but not in the MES-SA/Dx5 cells, and therefore cannot explain the strong PCI effect in the MES-SA/Dx5 cells. In conclusion PCI of recombinant gelonin circumvents ROS resistance in an apoptosis-independent manner. © 2013 Elsevier Inc. All rights reserved.

  13. Fracture resistance of teeth submitted to several internal bleaching protocols.

    Science.gov (United States)

    Leonardo, Renato de Toledo; Kuga, Milton Carlos; Guiotti, Flávia Angélica; Andolfatto, Carolina; Faria-Júnior, Norberto Batista de; Campos, Edson Alves de; Keine, Kátia Cristina; Dantas, Andrea Abi Rached

    2014-03-01

    The aim of this study was to evaluate the fracture resistance of teeth submitted to several internal bleaching protocols using 35% hydrogen peroxide (35HP), 37% carbamide peroxide (37CP), 15% hydrogen peroxide with titanium dioxide nanoparticles (15HPTiO2) photoactivated by LED-laser or sodium perborate (SP). After endodontic treatment, fifty bovine extracted teeth were divided into five groups (n = 10): G1-unbleached; G2-35HP; G3-37CP; G4-15HPTiO2 photoactivated by LED-laser and G5-SP. In the G2 and G4, the bleaching protocol was applied in 4 sessions, with 7 days intervals between each session. In the G3 and G5, the materials were kept in the pulp teeth for 21 days, but replaced every 7 days. After 21 days, the teeth were subjected to compressive load at a cross head speed of 0.5 mm/min, applied at 135° to the long axis of the root using an eletromechanical testing machine, until teeth fracture. The data were submitted to ANOVA and Tukey tests (α = 5%). The 35HP, 37CP, 15HPTiO2 and SP showed similar fracture resistance teeth reduction (p > 0.05). All bleaching treatments reduced the fracture resistance compared to unbleached teeth (p endodontically-treated teeth, but there were no differences between each other. There are several internal bleaching protocols using hydrogen peroxide in different concentrations and activation methods. This study evaluated its effects on fracture resistance in endodontically-treated teeth.

  14. Towards the improvement of the oxidation resistance of Nb-silicides in situ composites: A solid state diffusion approach

    International Nuclear Information System (INIS)

    Mathieu, S.; Knittel, S.; François, M.; Portebois, L.; Mathieu, S.; Vilasi, M.

    2014-01-01

    Highlights: •Local equilibrium is attained during oxidation at phase boundaries (steady state conditions). •A solid state diffusion model explains the oxidation mechanism of Nb-silicides composites. •The Nb ss fraction is not the only parameters governing the oxidation rate of Nb-silicides. •Aluminium increases the thermodynamic activity of Si in the Nb-silicides composites. •The results indicate the need to develop a Nb–Ti–Hf–Al–Cr–Si thermodynamic database. -- Abstract: The present study focuses on the oxidation mechanism of Nb-silicide composites and on the effect of the composition on the oxidation rate at 1100 °C. A theoretical approach is proposed based on experimental results and used to optimise the oxidation resistance. The growth model based on multiphase diffusion was experimentally tested and confirmed by manufacturing seven composites with different compositions. It was also found that the effect of the composition has to be evaluated at 1100 °C within a short time duration (50 h), where the oxide scale and the internal oxidation zone both grow according to parabolic kinetics

  15. A study on the determination of diffusion coefficient of carbon in 304 austenitic stainless steels by internal friction method

    International Nuclear Information System (INIS)

    Kim, K.S.; Kim, T.H.

    1982-01-01

    Internal friction peaks associated with the presence of carbon in 18-8 type 304 stainless steel have been observed from measurements with a torsion pendulum. The temperature for maximum internal friction lies between 250degC and 300degC with a frequency of vibration. The height of the peak rises and the position of the peak shifts to a lower temperature with an increase of the carbon content. And a comparison of the activation energy and the diffusion coefficient determined by internal friction methods with those measured in conventional macro-diffusion experiments reveals that the diffusion data measured by internal friction method and the diffusion data measured by conventional method exist in the same line. It follows from the above fact that observed internal friction peak is associated with the stress-induced diffusion of carbon in face-centered cubic alloys. (Author)

  16. Power dependence of ion thermal diffusivity at the internal transport barrier in JT-60U

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Yoshiteru; Suzuki, Takahiro; Ide, Shunsuke [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment] [and others

    2002-09-01

    The formation properties of an internal transport barrier (ITB) were investigated in a weak positive magnetic shear plasma by changing the neutral beam heating power. The ion thermal diffusivity in the core region shows L-mode state, weak ITB, and strong ITB, depending upon the heating power. Two features of ITB formation were experimentally confirmed. Weak ITB was formed in spite of the absence of an apparent transition in an ion temperature profile. On the other hand, strong ITB appeared after an apparent transition from the weak ITB. In addition, the ion thermal diffusivity at the ITB is correlated to the radial electric field shear. In the case of the weak ITB, ion thermal diffusivity decreased gradually with increases in the radial electric field shear. There exists a threshold in the radial electric field shear, which allows for a change in state from that of weak to strong ITBs. (author)

  17. Sensitivity enhancement of polysilicon piezo-resistive pressure sensors with phosphorous diffused resistors

    International Nuclear Information System (INIS)

    Sivakumar, K; Dasgupta, N; Bhat, K N; Natarajan, K

    2006-01-01

    It is generally accepted that the piezo-resistive coefficient in single crystal silicon is higher when P-type impurities such as boron are used for doping the resistors. In this paper we demonstrate that the sensitivity of polycrystalline silicon piezo-resistive pressure sensors can be enhanced considerably when phosphorus diffusion source is used instead of boron dopant for realizing the piezo-resistors. Pressure sensors have been designed and fabricated with the polycrystalline piezo-resistors connected in the form of a Wheatstone bridge and laid out on thermal oxide grown on membranes obtained with a Silicon On Insulator (SOI) approach. The SOI wafers required for this purpose have been realized in-house by Silicon Fusion Bonding (SFB) and etch back technique in our laboratory. This approach provides excellent isolation between the resistors and enables zero temperature coefficient of the polysilicon resistor. The results obtained in our laboratory have clearly demonstrated that by optimizing the phosphorus diffusion temperature and duration, it is possible to achieve sensitivities in excess of 20mV /Bar for bridge input voltage of 10V, with linearity within 1% over a differential pressure range up to 10Bar (10 6 Pascal), and burst pressure in excess of 50 Bar as compared to the 10mV /Bar sensitivity obtained with boron doped polysilicon piezo-resistors. This enhancement is attributed to grain boundary passivation by phosphorous atoms

  18. The effect of chromium diffusion redistribution on wear resistance of carburized 3Kh13 steel

    International Nuclear Information System (INIS)

    Shcherbedinskij, G.V.; Shumakov, A.I.; Zemskij, S.V.; Pereverzev, V.M.

    1977-01-01

    The redistribution of chromium in steel 3Kh13 on carburization in a high-activity carburizer and the wear-resistance of the steel have been investigated. Surface layers with an increased chromium concentration show the highest wear-resistance. The chromium content in the surface layer increases due to its diffusion from the interior. The distribution of carbon and chromium in the carburized layers has been studied with the aid of the radioactive isotope 14 C by the method of layer-by-layer spectral analysis on a vacuum quantometer, layer-by-layer chemical and X-ray structure analysis. The composition of the carbides has been determined by physicochemical analysis. It has been established that the carburized layer can be divided into four zones with respect to its phase composition: first zone - hematite and spinal with 0.5-2.0% C; second zone - solid carbides (Fe,Cr) 7 C 3 ; up to 5% C; third zone - globular carbides in a troostite matrix (Cr,Fe) 7 C 3 and Cr 23 C 6 ; up to 3.5% C; fourth, transitional, zone - troostite carbide mixture Cr 23 C 6 ; up to 1% C. The chromium diffusion in the carburized layer is faster than in the initial austenite. The chromium counterdiffusion is due to the development of a zone of solid carbides M 7 C 3

  19. Development of proliferation resistance assessment methodology based on international standard

    International Nuclear Information System (INIS)

    Ko, W. I.; Chang, H. L.; Lee, Y. D.; Lee, J. W.; Park, J. H.; Kim, Y. I.; Ryu, J. S.; Ko, H. S.; Lee, K. W.

    2012-04-01

    Nonproliferation is one of the main requirements to be satisfied by the advanced future nuclear energy systems that have been developed in the Generation IV and INPRO studies. The methodologies to evaluate proliferation resistance has been developed since 1980s, however, the systematic evaluation approach has begun from around 2000. Domestically a study to develop national method to evaluate proliferation resistance (PR) of advanced future nuclear energy systems has started in 2007 as one of the long-term nuclear R and D subjects in order to promote export and international credibility and transparency of national nuclear energy systems and nuclear fuel cycle technology development program. In the first phase (2007-2010) development and improvement of intrinsic evaluation parameters for the evaluation of proliferation resistance, quantification of evaluation parameters, development of evaluation models, and development of permissible ranges of evaluation parameters have been carried out. In the second phase (2010-2012) generic principle of to evaluate PR was established, and techincal guidelines, nuclear material diversion pathway analysis method, and a method to integrate evaluation parameters have been developed. which were applied to 5 alternative nuclear fuel cycles to estimate their appicability and objectivity. In addition, measures to enhance PR of advanced future nuclear energy systems and technical guidelines of PR assessment using intrinsic PR evaluation parameters were developed. Lastly, requlatory requirements to secure nonproliferation requirements of nuclear energy systems from the early design stage, operation and to decommissioning which will support the export of newly developed advanced future nuclear energy system

  20. Accelerating resistance, inadequate antibacterial drug pipelines and international responses.

    Science.gov (United States)

    Theuretzbacher, Ursula

    2012-04-01

    The pandemic of multidrug-resistant (MDR) pathogens and their continuing spread is beyond dispute. In contrast to the past, today's antibacterial research and development (R&D) pipelines are nearly dry, failing to provide the flow of novel antibiotics required to match the clinical challenges of the multidrug resistance (MDR) crisis. Concerned over the rapidly worsening potential global healthcare crisis caused by MDR bacteria and the lack of robust drug pipelines, several multinational campaigns have issued policy recommendations and have initiated broad discussion with a goal of stimulating the development of novel antibacterial drugs and technologies. These activities have resulted in intensified co-operation between the USA and the EU. The recently announced extensive 'Action plan against the rising threats from antimicrobial resistance' substantially ramps up action within the EU. In recognising the potential crisis caused by MDR and the limited treatment options, the European Commission decided on an unprecedented approach to drive the search for novel antibiotics by integrating the pharmaceutical industry, the research capacities of universities and small companies supported by public funding along with pricing/reimbursement and regulatory bodies. The European Commission has shown leadership and put action plans in place. Only the future will tell whether these initiatives will help curb the impact of the MDR pandemic. Copyright © 2012 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  1. Influence of Cu diffusion conditions on the switching of Cu-SiO2-based resistive memory devices

    International Nuclear Information System (INIS)

    Thermadam, S. Puthen; Bhagat, S.K.; Alford, T.L.; Sakaguchi, Y.; Kozicki, M.N.; Mitkova, M.

    2010-01-01

    This paper presents a study of Cu diffusion at various temperatures in thin SiO 2 films and the influence of diffusion conditions on the switching of Programmable Metallization Cell (PMC) devices formed from such Cu-doped films. Film composition and diffusion products were analyzed using secondary ion mass spectroscopy, Rutherford backscattering spectrometry, X-ray diffraction and Raman spectroscopy methods. We found a strong dependence of the diffused Cu concentration, which varied between 0.8 at.% and 10 -3 at.%, on the annealing temperature. X-ray diffraction and Raman studies revealed that Cu does not react with the SiO 2 network and remains in elemental form after diffusion for the annealing conditions used. PMC resistive memory cells were fabricated with such Cu-diffused SiO 2 films and device performance, including the stability of the switching voltage, is discussed in the context of the material characteristics.

  2. Development of Proliferation Resistance Assessment Methodology Based on International Standards

    International Nuclear Information System (INIS)

    Lee, Yong Deok; Lee, Jung Won; Lee, Kwang Seok

    2009-03-01

    Proliferation resistance is one of the requirement to be met in GEN IV and INPRO for next generation nuclear energy system. Internationally, the evaluation methodology on PR had been already initiated from 1980, but the systematic development was started at 2000s. In Korea, for the export of nuclear energy system and the increase of international credibility and transparence of domestic nuclear system and fuel cycle development, the independent development of PR evaluation methodology was started in 2007 as a nuclear long term R and D project and the development is being performed for the model of PR evaluation methodology. In 1st year, comparative study of GEN-IV/INPRO, PR indicator development, quantification of indicator and evaluation model development, analysis of technology system and international technology development trend had been performed. In 2nd year, feasibility study of indicator, allowable limit of indicator, review of technical requirement of indicator were done. The results of PR evaluation must be applied in the beginning of conceptual design of nuclear system. Through the technology development of PR evaluation methodology, the methodology will be applied in the regulatory requirement for authorization and permission to be developed

  3. Oxidation resistant peroxide cross-linked UHMWPE produced by blending and surface diffusion

    International Nuclear Information System (INIS)

    Gul, Rizwan M; Oral, Ebru; Muratoglu, Orhun K

    2014-01-01

    Ultra-high molecular weight polyethylene (UHMWPE) has been widely used as acetabular cup in total hip replacement (THR) and tibial component in total knee replacement (TKR). Crosslinking of UHMWPE has been successful used to improve its wear performance leading to longer life of orthopedic implants. Crosslinking can be performed by radiation or organic peroxides. Peroxide crosslinking is a convenient process as it does not require specialized equipment and the level of crosslinking can be manipulated by changing the amount of peroxide added. However, there is concern about the long-term stability of these materials due to possible presence of by-products. Vitamin E has been successfully used to promote long-term oxidative stability of UHMWPE. In this study, UHMWPE has been crosslinked using organic peroxide in the presence of Vitamin E to produce an oxidation resistant peroxide crosslinked material. Crosslinking was performed both in bulk by mixing peroxide and resin, and only on the surface using diffusion of peroxides.The results show that UHMWPE can be crosslinked using organic peroxides in the presence of vitamin E by both methods. However, the level of crosslinking decreases with the increase in vitamin E content. The wear resistance increases with the increase in crosslink density, and oxidation resistance significantly increases due to the presence of vitamin E

  4. Oxidation resistant peroxide cross-linked UHMWPE produced by blending and surface diffusion

    International Nuclear Information System (INIS)

    Gul, R. M.; Oral, E.; Muratoglu, O. K.

    2013-01-01

    Ultra-high molecular weight polyethylene (UHMWPE) has been widely used as acetabular cup in total hip replacement (THR) and tibial component in total knee replacement (TKR). Crosslinking of UHMWPE has been successful used to improve its wear performance leading to longer life of orthopedic implants. Crosslinking can be performed by radiation or organic peroxides. Peroxide crosslinking is a convenient process as it does not require specialized equipment and the level of crosslinking can be manipulated by changing the amount of peroxide added. However, there is concern about the long-term stability of these materials due to possible presence of by-products. Vitamin E has been successfully used to promote long-term oxidative stability of UHMWPE. In this study, UHMWPE has been crosslinked using organic peroxide in the presence of Vitamin E to produce an oxidation resistant peroxide crosslinked material. Crosslinking was performed both in bulk by mixing peroxide and resin, and only on the surface using diffusion of peroxides.The results show that UHMWPE can be crosslinked using organic peroxides in the presence of vitamin E by both methods. However, the level of crosslinking decreases with the increase in vitamin E content. The wear resistance increases with the increase in crosslink density, and oxidation resistance significantly increases due to the presence of vitamin E. (author)

  5. Investigations on diffusion-controlled transformations in creep resistant steels and graded cemented carbides

    International Nuclear Information System (INIS)

    Prat Borquez, Orlando

    2011-01-01

    The objective of this work was to simulate diffusion-controlled transformations on engineering alloys designed by the author and his colleagues. The main challenge of the work is to adapt the existing DICTRA models to the experimental processing and working conditions investigated, as well as to find the adequate boundary conditions for the description of the diffusion-controlled transformations governing the microstructure formation and evolution, in order to obtain reliable simulation results. The simulations were compared with experimental results of the microstructure evolution by scanning electron microscopy and scanning transmission electron microscopy (STEM). Two groups of materials were investigated. The first group was 9-12% Cr heat resistant alloys. These alloys are particularly interesting because the microstructure evolves during working conditions. Different compositions were designed in order to form different kinds and amounts of precipitates. For the designed 9-12% Cr creep steels the coarsening of MX and M 23 C 6 particles was modeled by applying the coarsening model implemented in DICTRA. The cell method of DICTRA was applied to investigate the kinetics of the Laves phase growth on 9-12% Cr alloys. The particular objectives of these investigations were: a) to determine the coarsening rate of precipitates, b) to investigate the influence of alloying element on the growth rate of the Laves phase, c) to determine the influence of the M 23 C 6 formation on the growth kinetics of the Laves phase, d) to determine the growth mechanism at the interface of the Laves phase (i.e. up-hill diffusion), e) to investigate the effect of the cell size on the simulation kinetics of Laves phase. The second group of materials was cemented carbides. They are used as cutting tools or wear parts in the automotive, aircraft and mining industry among others. The wear performance of cemented carbides (hardmetals and cermets) can be largely improved by applying wear

  6. Enhanced oxygen vacancy diffusion in Ta2O5 resistive memory devices due to infinitely adaptive crystal structure

    Science.gov (United States)

    Jiang, Hao; Stewart, Derek A.

    2016-04-01

    Metal oxide resistive memory devices based on Ta2O5 have demonstrated high switching speed, long endurance, and low set voltage. However, the physical origin of this improved performance is still unclear. Ta2O5 is an important archetype of a class of materials that possess an adaptive crystal structure that can respond easily to the presence of defects. Using first principles nudged elastic band calculations, we show that this adaptive crystal structure leads to low energy barriers for in-plane diffusion of oxygen vacancies in λ phase Ta2O5. Identified diffusion paths are associated with collective motion of neighboring atoms. The overall vacancy diffusion is anisotropic with higher diffusion barriers found for oxygen vacancy movement between Ta-O planes. Coupled with the fact that oxygen vacancy formation energy in Ta2O5 is relatively small, our calculated low diffusion barriers can help explain the low set voltage in Ta2O5 based resistive memory devices. Our work shows that other oxides with adaptive crystal structures could serve as potential candidates for resistive random access memory devices. We also discuss some general characteristics for ideal resistive RAM oxides that could be used in future computational material searches.

  7. Ion permeability of artificial membranes evaluated by diffusion potential and electrical resistance measurements.

    Science.gov (United States)

    Shlyonsky, Vadim

    2013-12-01

    In the present article, a novel model of artificial membranes that provides efficient assistance in teaching the origins of diffusion potentials is proposed. These membranes are made of polycarbonate filters fixed to 12-mm plastic rings and then saturated with a mixture of creosol and n-decane. The electrical resistance and potential difference across these membranes can be easily measured using a low-cost volt-ohm meter and home-made Ag/AgCl electrodes. The advantage of the model is the lack of ionic selectivity of the membrane, which can be modified by the introduction of different ionophores to the organic liquid mixture. A membrane treated with the mixture containing valinomycin generates voltages from -53 to -25 mV in the presence of a 10-fold KCl gradient (in to out) and from -79 to -53 mV in the presence of a bi-ionic KCl/NaCl gradient (in to out). This latter bi-ionic gradient potential reverses to a value from +9 to +20 mV when monensin is present in the organic liquid mixture. Thus, the model can be build stepwise, i.e., all factors leading to the development of diffusion potentials can be introduced sequentially, helping students to understand the quantitative relationships of ionic gradients and differential membrane permeability in the generation of cell electrical signals.

  8. Time-dependent free boundary equilibrium and resistive diffusion in a tokamak plasma

    International Nuclear Information System (INIS)

    Selig, G.

    2012-12-01

    In a Tokamak, in order to create the necessary conditions for nuclear fusion to occur, a plasma is maintained by applying magnetic fields. Under the hypothesis of an axial symmetry of the tokamak, the study of the magnetic configuration at equilibrium is done in two dimensions, and is deduced from the poloidal flux function. This function is solution of a non linear partial differential equation system, known as equilibrium problem. This thesis presents the time dependent free boundary equilibrium problem, where the circuit equations in the tokamak coils and passive conductors are solved together with the Grad-Shafranov equation to produce a dynamic simulation of the plasma. In this framework, the Finite Element equilibrium code CEDRES has been improved in order to solve the aforementioned dynamic problem. Consistency tests and comparisons with the DINA-CH code on an ITER vertical instability case have validated the results. Then, the resistive diffusion of the plasma current density has been simulated using a coupling between CEDRES and the averaged one-dimensional diffusion equation, and it has been successfully compared with the integrated modeling code CRONOS. (author)

  9. Measurement of internal quality of watermelon by Vis/NIR diffuse transmittance technique

    Science.gov (United States)

    Tian, Haiqing; Xu, Huirong; Ying, Yibin; Lu, Huishan; Yu, Haiyan

    2006-10-01

    Watermelon is a popular fruit in the world. Soluble solids content (SSC) is major characteristic used for assessing watermelon internal quality. This study was about a method for nondestructive internal quality detection of watermelons by means of visible/Near Infrared (Vis/NIR) diffuse transmittance technique. Vis/NIR transmittance spectra of intact watermelons were acquired using a low-cost commercially available spectrometer when the watermelon was in motion (1.4m/s) and in static state. Spectra data were analyzed by partial least squares (PLS) method. The influences of different data preprocessing and spectra treatments were also investigated. Performance of different models was assessed in terms of root mean square errors of calibration (RMSEC), root mean square errors of prediction (RMSEP) and correlation coefficient (r) between the predicted and measured parameter values. Results showed that spectra data preprocessing influenced the performance of the calibration models and the PLS method can provide good results. The nondestructive Vis/NIR measurements provided good estimates of SSC index of watermelon both in motion and in static state, and the predicted values were highly correlated with destructively measured values. The results indicated the feasibility of Vis/NIR diffuse transmittance spectral analysis for predicting watermelon internal quality in a nondestructive way.

  10. A Quantitative Property-Property Relationship for the Internal Diffusion Coefficients of Organic Compounds in Solid Materials

    DEFF Research Database (Denmark)

    Huang, Lei; Fantke, Peter; Jolliet, Olivier

    2017-01-01

    of chemical-material combinations. This paper develops and evaluates a quantitative property-property relationship (QPPR) to predict diffusion coefficients for a wide range of organic chemicals and materials. We first compiled a training dataset of 1103 measured diffusion coefficients for 158 chemicals in 32......Indoor releases of organic chemicals encapsulated in solid materials are major contributors to human exposures and are directly related to the internal diffusion coefficient in solid materials. Existing correlations to estimate the diffusion coefficient are only valid for a limited number...... consolidated material types. Following a detailed analysis of the temperature influence, we developed a multiple linear regression model to predict diffusion coefficients as a function of chemical molecular weight (MW), temperature, and material type (adjusted R2 of 0.93). The internal validations showed...

  11. In situ resistance measurements of bronze process Nb-Sn-Cu-Ta multifilamentary composite conductors during reactive diffusion

    International Nuclear Information System (INIS)

    Tan, K S; Hopkins, S C; Glowacki, B A; Majoros, M; Astill, D

    2004-01-01

    The conditions under which the Nb 3 Sn intermetallic layer is formed by solid-state reactive diffusion processes in bronze process multifilamentary conductors greatly influence the performance of the conductors. By convention, isothermal heat treatment is used and often causes non-uniformity of A15 layers formed across the wire. Therefore, characterization and optimization of the conductor during the reactive diffusion processes is crucial in order to improve the overall conductor's performance. In this paper, a different characterization approach and perhaps an optimization technique is presented, namely in situ resistance measurement by an alternating current (AC) method. By treating the components of such multifilamentary wires as a set of parallel resistors, the resistances of the components may be combined using the usual rules for resistors in parallel. The results show that the resistivity of the entire wire changes significantly during the reactive diffusion processes. The development of the Nb 3 Sn layer in bronze process Nb-Sn-Cu-Ta multifilamentary wires at different stages of the reactive diffusion processes has been monitored using measured resistivity changes, and correlated with results from DTA, ACS, SEM and EDS

  12. Etude de la structure interne du nucleon en diffusion profondement inelastique de muons sur cibles fixes.

    CERN Document Server

    Granier, Thierry

    Dans ce mémoire est présentée l'analyse, dans le but de l'extraction des fonctions de structure, d'une partie des données de diffusion profondément inélastique de muons sur cibles fixes d'hydrogène et de detérium obtenues dans l'expérience NMC (New Muon Collaboration) du CERN. Les fonctions de structure, à partir desquelles s'exprime la probabilité de diffusion à un certain angle et une certaine énergie, contiennent de l'information sur la structure interne du nucléon, plus précisément sur la distribution en énergie des quarks à l'intérieur de celui-ci. L'étude de la variation des fonctions de structure avec le degré d'inélasticité de la diffusion permet de tester la validité de la chromodynamique quantique, la théorie de jauge des interactions fortes

  13. Diffusion tensor imaging, intracranial vascular resistance and cognition in middle-aged asymptomatic subjects.

    Science.gov (United States)

    López-Olóriz, Jorge; López-Cancio, Elena; Arenillas, Juan F; Hernández, María; Dorado, Laura; Dacosta-Aguayo, Rosalía; Barrios, Maite; Soriano-Raya, Juan José; Miralbell, Júlia; Bargalló, Núria; Cáceres, Cynthia; Torán, Pere; Alzamora, Maite; Dávalos, Antonio; Mataró, Maria

    2014-01-01

    The contribution of traditional vascular risk factors to cognitive impairment and dementia is well known. However, in order to obtain possible targets for prevention of vascular cognitive impairment (VCI), it may be important to identify other early and noninvasive markers in asymptomatic middle-aged adults. The calculation of middle cerebral artery-pulsatility index (MCA-PI) is an ultrasonologic, noninvasive, validated and easily reproducible technique to assess increased distal resistance to blood flow. This study aims to assess the relationship between MCA-PI, microstructural white matter (WM) integrity and cognition in a middle-aged asymptomatic population. Ninety-five participants from the Barcelona-Asymptomatic Intracranial Atherosclerosis (AsIA) neuropsychology study were included. Subjects were 50-65 years old, free from dementia and without history of vascular disease. Transcranial color-coded duplex ultrasound examination was performed to assess MCA-PI as a measure of vascular resistance. WM integrity was evaluated by fractional anisotropy (FA) measurements of diffusion tensor images (DTI) acquired on a 3T-MRI. The neuropsychological battery was specifically selected to be sensitive to VCI, and included tests that were grouped into six cognitive domains: executive functioning, attention, verbal fluency, memory, visuospatial skills and psychomotor speed. A multivariate linear regression model adjusted for age, gender, years of education, diabetes and hypertension was performed. MCA-PI was significantly associated with WM disintegration in different tracts (fornix, corticospinal and anterior thalamic), all p gender, years of education, and vascular risk factors (all p cognitive domains, except for visuospatial skills. Our data suggest that MCA-PI may be related to WM disintegration and early vascular cognitive impairment in middle-aged subjects. Although further prospective studies are needed to provide evidence for its validity in longitudinal studies, our

  14. Species specificity of resistance to oxygen diffusion in thin cuticular membranes from amphibious plants

    DEFF Research Database (Denmark)

    Frost-Christensen, Henning; Jørgensen, Lise Bolt; Floto, Franz

    2003-01-01

    oxygen, diffusion, cuticula, amphibious plants, Hygrophila, Berula, Lobelia, Mentha, Potamogeton, Veronica, aquatic plants, submerged plants......oxygen, diffusion, cuticula, amphibious plants, Hygrophila, Berula, Lobelia, Mentha, Potamogeton, Veronica, aquatic plants, submerged plants...

  15. A multiscale MD-FE model of diffusion in composite media with internal surface interaction based on numerical homogenization procedure.

    Science.gov (United States)

    Kojic, M; Milosevic, M; Kojic, N; Kim, K; Ferrari, M; Ziemys, A

    2014-02-01

    Mass transport by diffusion within composite materials may depend not only on internal microstructural geometry, but also on the chemical interactions between the transported substance and the material of the microstructure. Retrospectively, there is a gap in methods and theory to connect material microstructure properties with macroscale continuum diffusion characteristics. Here we present a new hierarchical multiscale model for diffusion within composite materials that couples material microstructural geometry and interactions between diffusing particles and the material matrix. This model, which bridges molecular dynamics (MD) and the finite element (FE) method, is employed to construct a continuum diffusion model based on a novel numerical homogenization procedure. The procedure is general and robust for evaluating constitutive material parameters of the continuum model. These parameters include the traditional bulk diffusion coefficients and, additionally, the distances from the solid surface accounting for surface interaction effects. We implemented our models to glucose diffusion through the following two geometrical/material configurations: tightly packed silica nanospheres, and a complex fibrous structure surrounding nanospheres. Then, rhodamine 6G diffusion analysis through an aga-rose gel network was performed, followed by a model validation using our experimental results. The microstructural model, numerical homogenization and continuum model offer a new platform for modeling and predicting mass diffusion through complex biological environment and within composite materials that are used in a wide range of applications, like drug delivery and nanoporous catalysts.

  16. A multiscale MD–FE model of diffusion in composite media with internal surface interaction based on numerical homogenization procedure

    Science.gov (United States)

    Kojic, M.; Milosevic, M.; Kojic, N.; Kim, K.; Ferrari, M.; Ziemys, A.

    2014-01-01

    Mass transport by diffusion within composite materials may depend not only on internal microstructural geometry, but also on the chemical interactions between the transported substance and the material of the microstructure. Retrospectively, there is a gap in methods and theory to connect material microstructure properties with macroscale continuum diffusion characteristics. Here we present a new hierarchical multiscale model for diffusion within composite materials that couples material microstructural geometry and interactions between diffusing particles and the material matrix. This model, which bridges molecular dynamics (MD) and the finite element (FE) method, is employed to construct a continuum diffusion model based on a novel numerical homogenization procedure. The procedure is general and robust for evaluating constitutive material parameters of the continuum model. These parameters include the traditional bulk diffusion coefficients and, additionally, the distances from the solid surface accounting for surface interaction effects. We implemented our models to glucose diffusion through the following two geometrical/material configurations: tightly packed silica nanospheres, and a complex fibrous structure surrounding nanospheres. Then, rhodamine 6G diffusion analysis through an aga-rose gel network was performed, followed by a model validation using our experimental results. The microstructural model, numerical homogenization and continuum model offer a new platform for modeling and predicting mass diffusion through complex biological environment and within composite materials that are used in a wide range of applications, like drug delivery and nanoporous catalysts. PMID:24578582

  17. Investigation of gas-phase decontamination of internally radioactively contaminated gaseous diffusion process equipment and piping

    International Nuclear Information System (INIS)

    Bundy, R.D.; Munday, E.B.

    1991-01-01

    Construction of the gaseous diffusion plants (GDPs) was begun during World War 2 to produce enriched uranium for defense purposes. These plants, which utilized UF 6 gas, were used primarily for this purpose through 1964. From 1959 through 1968, production shifted primarily to uranium enrichment to supply the nuclear power industry. Additional UF 6 -handling facilities were built in feed and fuel-processing plants associated with the uranium enrichment process. Two of the five process buildings at Oak ridge were shut down in 1964. Uranium enrichment activities at Oak Ridge were discontinued altogether in 1985. In 1987, the Department of Energy (DOE) decided to proceed with a permanent shutdown of the Oak Ridge Gaseous Diffusion Plant (ORGDP). DOE intends to begin decommissioning and decontamination (D ampersand D) of ORGDP early in the next century. The remaining two GDPs are expected to be shut down during the next 10 to 40 years and will also require D ampersand D, as will the other UF 6 -handling facilities. This paper presents an investigation of gas- phase decontamination of internally radioactively contaminated gaseous diffusion process equipment and piping using powerful fluorinating reagents that convert nonvolatile uranium compounds to volatile UF 6 . These reagents include ClF 3 , F 2 , and other compounds. The scope of D ampersand D at the GDPs, previous work of gas-phase decontamination, four concepts for using gas-phase decontamination, plans for further study of gas-phase decontamination, and the current status of this work are discussed. 13 refs., 15 figs

  18. The evolution of bacterial cell size: the internal diffusion-constraint hypothesis.

    Science.gov (United States)

    Gallet, Romain; Violle, Cyrille; Fromin, Nathalie; Jabbour-Zahab, Roula; Enquist, Brian J; Lenormand, Thomas

    2017-07-01

    Size is one of the most important biological traits influencing organismal ecology and evolution. However, we know little about the drivers of body size evolution in unicellulars. A long-term evolution experiment (Lenski's LTEE) in which Escherichia coli adapts to a simple glucose medium has shown that not only the growth rate and the fitness of the bacterium increase over time but also its cell size. This increase in size contradicts prominent 'external diffusion' theory (EDC) predicting that cell size should have evolved toward smaller cells. Among several scenarios, we propose and test an alternative 'internal diffusion-constraint' (IDC) hypothesis for cell size evolution. A change in cell volume affects metabolite concentrations in the cytoplasm. The IDC states that a higher metabolism can be achieved by a reduction in the molecular traffic time inside of the cell, by increasing its volume. To test this hypothesis, we studied a population from the LTEE. We show that bigger cells with greater growth and CO 2 production rates and lower mass-to-volume ratio were selected over time in the LTEE. These results are consistent with the IDC hypothesis. This novel hypothesis offers a promising approach for understanding the evolutionary constraints on cell size.

  19. Noninvasive photoacoustic measurement of absorption coefficient using internal light irradiation of cylindrical diffusing fiber

    Science.gov (United States)

    Peng, Dong-qing; Zhu, Li-li; Li, Zhi-fang; Li, Hui

    2017-09-01

    Absorption coefficient of biological tissue is an important parameter in biomedicine, but its determination remains a challenge. In this paper, we propose a method using focusing photoacoustic imaging technique and internal light irradiation of cylindrical diffusing fiber (CDF) to quantify the target optical absorption coefficient. Absorption coefficients for ink absorbers are firstly determined through photoacoustic and spectrophotometric measurements at the same excitation, which demonstrates the feasibility of this method. Also, the optical absorption coefficients of ink absorbers with several concentrations are measured. Finally, the two-dimensional scanning photoacoustic image is obtained. Optical absorption coefficient measurement and simultaneous photoacoustic imaging of absorber non-invasively are the typical characteristics of the method. This method can play a significant role for non-invasive determination of blood oxygen saturation, the absorption-based imaging and therapy.

  20. High density high performance plasma with internal diffusion barrier in Large Helical Device

    International Nuclear Information System (INIS)

    Sakamoto, R.; Kobayashi, M.; Miyazawa, J.

    2008-10-01

    A attractive high density plasma operational regime, namely an internal diffusion barrier (IDB), has been discovered in the intrinsic helical divertor configuration on the Large Helical Device (LHD). The IDB which enables core plasma to access a high density/high pressure regime has been developed. It is revealed that the IDB is reproducibly formed by pellet fueling in the magnetic configurations shifted outward in major radius. Attainable central plasma density exceeds 1x10 21 m -3 . Central pressure reaches 1.5 times atmospheric pressure and the central β value becomes fairly high even at high magnetic field, i.e. β(0)=5.5% at B t =2.57 T. (author)

  1. A measurement method for determination of dc internal resistance of batteries and supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shuhong; Wu, Feng [Department of Materials Science, Beijing Science and Technology University, Beijing 100081 (China); Yang, Liuxiang; Gao, Lijun [Department of Chemistry, NanChang University, JiangXi 330031 (China); Burke, Andrew F. [Institute of Transportation, University of California, Davis, CA 95616 (United States)

    2010-02-15

    Internal resistance is an importance parameter determining the power performance of a battery or supercapacitor. An 8.5 Ah Li-ion battery and a 350 F supercapacitor were tested as examples to validate the measurement method of dc internal resistance. Voltage data were taken at 10 ms, 2 s and 30 s after the current interruption or pulse. The ac resistances at 1 kHz of the battery and supercapacitor were also measured for comparison with the dc values. Based on these tests, it is proposed that the dc internal resistance of the battery and supercapacitor be obtained from {delta}V/{delta}I where the {delta}V is the voltage change after the current interruption, and {delta}I means current change from I to 0. When the voltage change at 10 ms or less is selected, the resistance corresponds to the Ohmic resistance of the device. (author)

  2. Improving cylinder-type LiFePO4 battery performance via control of internal resistance

    Science.gov (United States)

    Purwanto, Agus; Jumari, Arif; Nizam, Muhammad; Widiyandari, Hendri; Sudaryanto; Deswita; Azmin Mohamad, Ahmad

    2018-04-01

    Strategies for controlling the internal resistance to improve battery performance were systematically investigated. Electrode densification of LiFePO4 cathodes significantly reduced the internal resistance of the prepared batteries. Densification by reduction to 31.25% of initial thickness resulted in optimal electrochemical performance of the prepared LiFePO4 batteries. The addition of KS 6 graphite material improved the conductivity of the cathodes, which was indicated by a lowering of the internal resistance. The internal resistance was decreased from 73 to 54 when the KS6/AB ratio was varied from 3 to 1. Another factor in controlling the internal resistance was the location of a welded aluminum tab in the cathode. The welding of an aluminum tab in a small gap in the cathode significantly reduced the internal resistance. Thus, three main factors can be performed during fabrication to reduce the internal resistance of a LiFePO4 battery: cathode densification, KS-6 graphite addition, and the arrangement of an aluminum tab welded to the cathode. By optimizing these factors, high-performance LFP batteries were produced.

  3. A micro-scale model for predicting contact resistance between bipolar plate and gas diffusion layer in PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y.; Lin, G.; Shih, A.J.; Hu, S.J. [Department of Mechanical Engineering, The University of Michigan, Ann Arbor, MI 48109-2125 (United States)

    2007-01-01

    Contact resistance between the bipolar plate (BPP) and the gas diffusion layer (GDL) in a proton exchange membrane (PEM) fuel cell constitutes a significant portion of the overall fuel cell electrical resistance under the normal operation conditions. Most current methods for contact resistance estimation are experimental and there is a lack of well developed theoretical methods. A micro-scale numerical model is developed to predict the electrical contact resistance between BPP and GDL by simulating the BPP surface topology and GDL structure and numerically determining the status for each contact spot. The total resistance and pressure are obtained by considering all contact spots as resistances in parallel and summing the results together. This model shows good agreements with experimental results. Influences of BPP surface roughness parameters on contact resistance are also studied. This model is beneficial in understanding the contact behavior between BPP and GDL and can be integrated with other fuel cell simulations to predict the overall performance of PEM fuel cells. (author)

  4. Spatial Variation of Diapycnal Diffusivity Estimated From Seismic Imaging of Internal Wave Field, Gulf of Mexico

    Science.gov (United States)

    Dickinson, Alex; White, N. J.; Caulfield, C. P.

    2017-12-01

    Bright reflections are observed within the upper 1,000 m of the water column along a seismic reflection profile that traverses the northern margin of the Gulf of Mexico. Independent hydrographic calibration demonstrates that these reflections are primarily caused by temperature changes associated with different water masses that are entrained into the Gulf along the Loop Current. The internal wave field is analyzed by automatically tracking 1,171 reflections, each of which is greater than 2 km in length. Power spectra of the horizontal gradient of isopycnal displacement, ϕξx, are calculated from these tracked reflections. At low horizontal wave numbers (kxcpm), ϕξx∝kx-0.2±0.6, in agreement with hydrographic observations of the internal wave field. The turbulent spectral subrange is rarely observed. Diapycnal diffusivity, K, is estimated from the observed internal wave spectral subrange of each tracked reflection using a fine-scale parametrization of turbulent mixing. Calculated values of K vary between 10-8 and 10-4 m2 s-1 with a mean value of K˜4×10-6 m2 s-1. The spatial distribution of turbulent mixing shows that K˜10-7 m2 s-1 away from the shelf edge in the upper 300 m where stratification is strong. Mixing is enhanced by up to 4 orders of magnitude adjacent to the shoaling bathymetry of the continental slope. This overall pattern matches that determined by analyzing nearby suites of CTD casts. However, the range of values recovered by spectral analysis of the seismic image is greater as a consequence of significantly better horizontal resolution.

  5. The effect of energetic trapped particles on the resistive internal Kink

    International Nuclear Information System (INIS)

    Romanelli, F.; White, R.B.

    1988-01-01

    The effect of energetic trapped particles on the ideal and resistive internal Kink mode is analyzed including diamagnetic effects. The relation between different approaches to the problem is discussed

  6. Resistive toroidal stability of internal kink modes in circular and shaped tokamaks

    International Nuclear Information System (INIS)

    Bondeson, A.; Luetjens, H.; Vlad, G.

    1991-12-01

    The linear resistive magnetohydrodynamical (MHD) stability of the n=1 internal kink mode in tokamaks is studied by toroidal computations. The stabilizing influence of small aspect ratio is confirmed, but it is found that shaping of the cross section influences the internal kink mode significantly. For finite pressure and small resistivity, curvature effects at the q=1 surface make the stability sensitively dependent on shape, and ellipticity (including JET shape) is destabilizing. Only a very restricted set of finite pressure equilibria is completely stable for q 0 <1. A typical result is that the resistive kink mode is slowed down by toroidal effects to a weak tearing/resistive interchange mode. It is suggested that weak resistive instabilities are stabilized during the ramp phase of the sawteeth by effects not included in the linear resistive MHD model. Possible mechanisms for triggering a sawtooth crash are discussed. (author) 18 figs., 34 refs

  7. Fracture resistance of the VNC-2USh steel with different content of diffusion-mobile hydrogen at low temperature

    International Nuclear Information System (INIS)

    Yablonskij, I.S.; Sankho, K.

    1979-01-01

    Presented are the investigation results for the diffusible hydrogen (DH) content effect on cracking resistance and mechanical properties of the VNC-2USh steel in the temperature range from -75-100 deg C. In this range σsub(B), σsub(0.2) and σ are not practically sensitive to the DH content change from 0.27 to 3 cm 3 /100g. At room temperature the increase of DH content in the above concentration range results in 45 % decrease of cracking resistance under static loading. At -75 deg C the cracking resistance does not depend on DH content. Within the temperature range from -40-75 deg C placed is a temperature boundary, separating the regions of predominant effects of hydrogen and low temperature embrittlement on repture strength of the VNC-2 steel at moderated rates of deformation

  8. New International Reference Standards of Voltage and Resistance.

    Science.gov (United States)

    Sirvastava, V. P.

    1991-01-01

    The introduction of the quantum standards of resistance and voltage, based on the Quantum Hall Effect (QHE) and the Josephson Effect, can be used to establish highly reproducible and uniform representations of the ohm and volt worldwide. Discussed are the QHE and the Josephson Effect. (KR)

  9. Characterization of internal wetting in polymer electrolyte membrane gas diffusion layers

    Science.gov (United States)

    Cheung, Perry; Fairweather, Joseph D.; Schwartz, Daniel T.

    Capillary pressure vs. saturation (P C(S L)) curves are fundamental to understanding liquid water transport and flooding in PEM gas diffusion layers (GDLs). P C(S L) curves convolute the influence of GDL pore geometry and internal contact angles at the three-phase liquid/solid/gas boundary. Even simple GDL materials are a spatially non-uniform mixture of carbon fiber and binder, making a Gaussian distribution of contact angles likely, based on the Cassie-Baxter equation. For a given Gaussian contact angle distribution with mean (θ Mean) and standard deviation (σ), a realistic P C(S L) curve can be computed using a bundle of capillaries model and GDL pore size distribution data. As expected, computed P C(S L) curves show that θ Mean sets the overall hydrophilic (θ Mean 90°) character of the GDL (i.e., liquid saturation level at a given capillary pressure), and σ affects the slope of the P C(S L) curve. The capillary bundle model also can be used with (θ Mean, σ) as unknown parameters that are best-fit to experimentally acquired P C(S L) and pore size distribution data to find (θ Mean, σ) values for actual GDL materials. To test this, pore size distribution data was acquired for Toray TGP-H-090 along with hysteretic liquid and gas intrusion capillary pressure curve data. High quality best-fits were found between the model and combined datasets, with GDL liquid intrusion showing fairly neutral internal surface wetting properties (θ Mean = 92° and σ = 10°) whereas gas intrusion displayed a hydrophilic character (θ Mean = 52° and σ = 8°). External liquid advancing and receding contact angles were also measured on this same material and they also showed major hysteresis. The new methods described here open the door for better understanding of the link between GDL material processing and the wetting properties that affect flooding.

  10. Chloride Diffusion and Acid Resistance of Concrete Containing Zeolite and Tuff as Partial Replacements of Cement and Sand.

    Science.gov (United States)

    Mohseni, Ehsan; Tang, Waiching; Cui, Hongzhi

    2017-03-31

    In this paper, the properties of concrete containing zeolite and tuff as partial replacements of cement and sand were studied. The compressive strength, water absorption, chloride ion diffusion and resistance to acid environments of concretes made with zeolite at proportions of 10% and 15% of binder and tuff at ratios of 5%, 10% and 15% of fine aggregate were investigated. The results showed that the compressive strength of samples with zeolite and tuff increased considerably. In general, the concrete strength increased with increasing tuff content, and the strength was further improved when cement was replaced by zeolite. According to the water absorption results, specimens with zeolite showed the lowest water absorption values. With the incorporation of tuff and zeolite, the chloride resistance of specimens was enhanced significantly. In terms of the water absorption and chloride diffusion results, the most favorable replacement of cement and sand was 10% zeolite and 15% tuff, respectively. However, the resistance to acid attack reduced due to the absorbing characteristic and calcareous nature of the tuff.

  11. Resistive internal kink modes in a tokamak with high-pressure plasma

    International Nuclear Information System (INIS)

    Kuvshinov, B.N.; Mikhajlovskij, A.B.; Tatarinov, E.G.

    1988-01-01

    Theory of resistive internal kink modes in a tokamak with high-pressure plasma is developed. Equation for Fourie-image of disturbed displacment in a resistive layer ie derived with regard to effects of the fourth order by plasma pressure within the framework of single-liquid approach. In its structure this equation coincides with a similar equation for resistive balloon modes and has an exact solution expressed by degenerated hypergeometric function. A general dispersion equation for resistive kink modes is derived with regard to the effects indicated. It is shown that plasma pressure finiteness leads to the reduction of reconnection and tyring-mode increments

  12. Spatial Control of Photoacid Diffusion in Chemically Amplified Resist (CAR) via External Electric Field.

    Science.gov (United States)

    Kim, Jinok; Yoo, Gwangwe; Park, Jin; Park, Jin-Hong

    2018-09-01

    We investigated the effect of an electric field-based post exposure bake (EF-PEB) process on photoacid diffusion and pattern formation. To investigate the control of photoacid diffusion experimentally, the EF-PEB processes was performed at various temperatures. Cross sectional images of various EF-PEB processed samples were obtained by scanning electron microscopy (SEM) after ion beam milling. In addition, we conducted a numerical analysis of photoacid distribution and diffusion with following Fick's second law and compared the experimental results with our theoretical model. The drift distance was theoretically predicted by multiplying drift velocity and EF-PEB time, and the experimental values were obtained by finding the difference in pattern depths of PEB/EFPEB samples. Finally, an EF-PEB temperature of 85 °C was confirmed as the optimum condition to maximize photoacid drift distance using the electric field.

  13. International Diffusion of Renewable Energy Innovations: Lessons from the Lead Markets for Wind Power in China, Germany and USA

    Directory of Open Access Journals (Sweden)

    Juliana Subtil Lacerda

    2014-12-01

    Full Text Available The international diffusion of environmental innovations is getting increasing attention as an opportunity to improve competitiveness. Especially in the energy sector, countries use policy support to this end. A recent goal in this context is the formation of “lead markets”, which represents the idea that countries can build up first-mover advantages that will increase their competitiveness. Taking the lead in international diffusion of a particular innovation benefits a country’s industry through creating increasing returns of technological development and stimulating exports to expanding international markets. Interaction between national and international forces affecting renewable energy innovation and its diffusion has received fairly little attention so far. Here, we investigate the formation of lead markets for wind power technologies in China, Germany and the USA to see whether policy support of renewable energy innovation is capable of improving competitiveness. An extension of the current lead market framework is developed to include supply side factors and technology policy issues. The comparative analysis of lead market potential for wind power indicates a high level of internationalization of the industry with countries holding lead positions in specific parts the supply chain. Competitive advantages were built upon policy support but tended to shift among countries.

  14. International Development Partnerships and Diffusion of Renewable Energy Technologies in Developing Countries: Cases in Latin America

    Science.gov (United States)

    Platonova, Inna

    Access to energy is vital for sustainable development and poverty alleviation, yet billions of people in developing countries continue to suffer from constant exposure to open fires and dangerous fuels, such as kerosene. Renewable energy technologies are being acknowledged as suitable solutions for remote rural communities in much of the developing world and international development non-governmental organizations (NGOs) increasingly play important roles in the diffusion of these technologies via development partnerships. While these partnerships are widely promoted, many questions related to their functioning and effectiveness remain open. To advance the theory and practice, this interdisciplinary exploratory research provides in-depth insights into the nature of international NGO-driven development partnerships in rural renewable energy and their effectiveness based on the case studies in Talamanca, Costa Rica and Cajamarca, Peru. The analysis of the nature of development partnerships shows that partnerships in the case studies differ in structure, size and diversity of actors due to differentiation in the implementation strategies, technological complexities, institutional and contextual factors. A multi-theoretical approach is presented to explain the multiple drivers of the studied development partnerships. The research highlights partnership constraints related to the provision of rural renewable energy, the organizational type and institutional environments. Based on the case studies this research puts forward theoretical propositions regarding the factors that affect the effectiveness of the partnerships. In terms of the partnership dynamics dimension, several key factors of success are confirmed from the existing literature, namely shared values and goals, complementary expertise and capacities, confidence and trust, clear roles and responsibilities, effective communication. Additional factors identified are personality match and continuity of staff. In

  15. Determination of internal series resistance of PV devices: repeatability and uncertainty

    International Nuclear Information System (INIS)

    Trentadue, Germana; Pavanello, Diego; Salis, Elena; Field, Mike; Müllejans, Harald

    2016-01-01

    The calibration of photovoltaic devices requires the measurement of their current–voltage characteristics at standard test conditions (STC). As the latter can only be reached approximately, a curve translation is necessary, requiring among others the internal series resistance of the photovoltaic device as an input parameter. Therefore accurate and reliable determination of the series resistance is important in measurement and test laboratories. This work follows standard IEC 60891 ed 2 (2009) for the determination of the internal series resistance and investigates repeatability and uncertainty of the result in three aspects for a number of typical photovoltaic technologies. Firstly the effect of varying device temperature on the determined series resistance is determined experimentally and compared to a theoretical derivation showing agreement. It is found that the series resistance can be determined with an uncertainty of better than 5% if the device temperature is stable within  ±0.1 °C, whereas the temperature range of  ±2 °C allowed by the standard leads to much larger variations. Secondly the repeatability of the series resistance determination with respect to noise in current–voltage measurement is examined yielding typical values of  ±5%. Thirdly the determination of the series resistance using three different experimental set-ups (solar simulators) shows agreement on the level of  ±5% for crystalline Silicon photovoltaic devices and deviations up to 15% for thin-film devices. It is concluded that the internal series resistance of photovoltaic devices could be determined with an uncertainty of better than 10%. The influence of this uncertainty in series resistance on the electrical performance parameters of photovoltaic devices was estimated and showed a contribution of 0.05% for open-circuit voltage and 0.1% for maximum power. Furthermore it is concluded that the range of device temperatures allowed during determination of series

  16. Effects of Sheet Resistance on mc-Si Selective Emitter Solar Cells Using Laser Opening and One-Step Diffusion

    Directory of Open Access Journals (Sweden)

    Sheng-Shih Wang

    2015-01-01

    Full Text Available In order to simplify process procedure and improve conversion efficiency (η, we present new steps of laser opening and one-step POCl3 diffusion to fabricate selective emitter (SE solar cells, in which heavily doped regions (HDR and lightly doped regions (LDR were formed simultaneously. For HDR, we divided six cells into two groups for POCl3 diffusion with sheet resistance (RS of 40 Ω/sq (for group A and 50 Ω/sq (for group B. The dry oxidation duration at a temperature of 850°C was 18, 25, and 35 min for the 3 different cells in each group. This created six SE samples with different RS pairings for the HDR and LDR. The optimal cell (sample SE2 with RS values of 40/81 Ω/Sq in HDR/LDR showed the best η of 16.20%, open circuit voltage (VOC of 612.52 mV, and fill factor (FF of 75.83%. The improvement ratios are 1.57% for η and 14.32% for external quantum efficiency (EQE as compared with those of the two-step diffusion process of our previous study. Moreover, the one-step laser opening process and omitting the step of removing the damage caused by laser ablation especially reduce chemistry pollution, thus showing ecofriendly process for use in industrial-scale production.

  17. Hydrogen diffusion and effect on degradation in welded microstructures of creep-resistant low-alloyed steels

    Energy Technology Data Exchange (ETDEWEB)

    Rhode, Michael

    2016-04-04

    The main challenge for the future is to further increase the power plant thermal efficiency independent of the type of power plant concept, i.e. fossil-fired or nuclear power plant, where the material selection can directly affect reduction of CO{sub 2} emissions. In power plant design, welding is the most applied manufacturing technique in component construction. The necessary weld heat input causes metallurgical changes and phase transitions in the heat affected zone (HAZ) of the base materials and in the deposited weld metal. The weld joint can absorb hydrogen during welding or in later service - This absorption can cause degradation of mechanical properties of the materials, and in certain loading conditions, hydrogen-assisted cold cracks can occur. This cracking phenomenon can appear time delayed due to the temperature dependency of the hydrogen diffusion and the presence of a ''critical'' hydrogen concentration. Additionally, each specific weld microstructure shows a certain hydrogen diffusion and solubility that contribute to susceptibility of the cracking phenomenon. Therefore hydrogen cannot be neglected as possible failure effect, which was identified recently in the case of T24 creep-resistant tube-to-tube weld joints. It is necessary to identify and assess the hydrogen effect in weld joints of low-alloyed steel grades for to improve further early detection of possible failures. For each specific weld joint microstructure, it is necessary to separate the interdependencies between mechanical load and the hydrogen concentration. The diffusivity and solubility must be considered to identify hydrogen quantities in the material at any given time. In this case, the effects of mechanical loading were dealt with independently. For the characterization of the mechanical properties, hydrogen charged tensile specimens were investigated for the base materials and thermally simulated HAZ microstructures. The hydrogen diffusion was characterized

  18. Hydrogen diffusion and effect on degradation in welded microstructures of creep-resistant low-alloyed steels

    International Nuclear Information System (INIS)

    Rhode, Michael

    2016-01-01

    The main challenge for the future is to further increase the power plant thermal efficiency independent of the type of power plant concept, i.e. fossil-fired or nuclear power plant, where the material selection can directly affect reduction of CO 2 emissions. In power plant design, welding is the most applied manufacturing technique in component construction. The necessary weld heat input causes metallurgical changes and phase transitions in the heat affected zone (HAZ) of the base materials and in the deposited weld metal. The weld joint can absorb hydrogen during welding or in later service - This absorption can cause degradation of mechanical properties of the materials, and in certain loading conditions, hydrogen-assisted cold cracks can occur. This cracking phenomenon can appear time delayed due to the temperature dependency of the hydrogen diffusion and the presence of a ''critical'' hydrogen concentration. Additionally, each specific weld microstructure shows a certain hydrogen diffusion and solubility that contribute to susceptibility of the cracking phenomenon. Therefore hydrogen cannot be neglected as possible failure effect, which was identified recently in the case of T24 creep-resistant tube-to-tube weld joints. It is necessary to identify and assess the hydrogen effect in weld joints of low-alloyed steel grades for to improve further early detection of possible failures. For each specific weld joint microstructure, it is necessary to separate the interdependencies between mechanical load and the hydrogen concentration. The diffusivity and solubility must be considered to identify hydrogen quantities in the material at any given time. In this case, the effects of mechanical loading were dealt with independently. For the characterization of the mechanical properties, hydrogen charged tensile specimens were investigated for the base materials and thermally simulated HAZ microstructures. The hydrogen diffusion was characterized with

  19. Comparison of Several Methods for Determining the Internal Resistance of Lithium Ion Cells

    Directory of Open Access Journals (Sweden)

    Hans-Georg Schweiger

    2010-06-01

    Full Text Available The internal resistance is the key parameter for determining power, energy efficiency and lost heat of a lithium ion cell. Precise knowledge of this value is vital for designing battery systems for automotive applications. Internal resistance of a cell was determined by current step methods, AC (alternating current methods, electrochemical impedance spectroscopy and thermal loss methods. The outcomes of these measurements have been compared with each other. If charge or discharge of the cell is limited, current step methods provide the same results as energy loss methods.

  20. Long-term performance of activated carbon air cathodes with different diffusion layer porosities in microbial fuel cells

    KAUST Repository

    Zhang, Fang; Pant, Deepak; Logan, Bruce E.

    2011-01-01

    to examine the reasons for the degraded performance. Diffusion resistance in the cathode was found to be the primary component of the internal resistance, and it increased over time. Replacing the cathode after 1 year completely restored the original power

  1. Photosynthesis of crop plants as influenced by light, carbon dioxide, temperature, and stomatal diffusion resistance

    NARCIS (Netherlands)

    Gaastra, P.

    1959-01-01

    The effect was estimated of light intensity, leaf temperature, and C0 2 concentration on photosynthetic rate in leaves of crop plants. The potential capacities of photochemical and biochemical processes and of C0 2 transport were compared.

    Resistance to C0 2

  2. On the resistances of membrane, diffusion boundary layer and double layer in ion exchange membrane transport

    NARCIS (Netherlands)

    Długołȩcki, P.; Ogonowski, P.; Metz, S.J.; Saakes, M.; Nijmeijer, K.; Wessling, M.

    2010-01-01

    Membrane resistances are often measured under direct current conditions using a standard 0.5 M NaCl characterization solution, although several electro-membrane processes (e.g. reverse electrodialysis, electrodialysis, fuel cells, microbial fuel cells and membrane capacitive deionization) operate in

  3. Heat-resistant materials 2. Conference proceedings of the 2. international conference on heat-resistant materials

    International Nuclear Information System (INIS)

    Natesan, K.; Ganesan, P.; Lai, G.Y.

    1995-01-01

    The Second International Conference on Heat-Resistant Materials was held in Gatlinburg, Tennessee, September 11--14, 1995 and focused on materials performance in cross-cutting technologies where heat resistant materials play a large and sometimes life-and performance-limiting roles in process schemes. The scope of materials for heat-resistant applications included structural iron- and nickel-base alloys, intermetallics, and ceramics. The conference focused on materials development, performance of materials in simulated laboratory and actual service environments on mechanical and structural integrity of components, and state-of-the-art techniques for processing and evaluating materials performance. The three keynote talks described the history of heat-resistant materials, relationship between microstructure and mechanical behavior, and applications of these materials in process schemes. The technical sessions included alloy metallurgy and properties, environmental effects and properties, deformation behavior and properties, relation between corrosion and mechanical properties, coatings, intermetallics, ceramics, and materials for waste incineration. Seventy one papers have been processed separately for inclusion on the data base

  4. Evolution of resistance to a multiple-herbivore community: genetic correlations, diffuse coevolution, and constraints on the plant's response to selection.

    Science.gov (United States)

    Wise, Michael J; Rausher, Mark D

    2013-06-01

    Although plants are generally attacked by a community of several species of herbivores, relatively little is known about the strength of natural selection for resistance in multiple-herbivore communities-particularly how the strength of selection differs among herbivores that feed on different plant organs or how strongly genetic correlations in resistance affect the evolutionary responses of the plant. Here, we report on a field study measuring natural selection for resistance in a diverse community of herbivores of Solanum carolinense. Using linear phenotypic-selection analyses, we found that directional selection acted to increase resistance to seven species. Selection was strongest to increase resistance to fruit feeders, followed by flower feeders, then leaf feeders. Selection favored a decrease in resistance to a stem borer. Bootstrapping analyses showed that the plant population contained significant genetic variation for each of 14 measured resistance traits and significant covariances in one-third of the pairwise combinations of resistance traits. These genetic covariances reduced the plant's overall predicted evolutionary response for resistance against the herbivore community by about 60%. Diffuse (co)evolution was widespread in this community, and the diffuse interactions had an overwhelmingly constraining (rather than facilitative) effect on the plant's evolution of resistance. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  5. Effect of Turbulence Internal Structure on Diffusion of Heavy Inertial Particles

    Directory of Open Access Journals (Sweden)

    I. V. Derevich

    2015-01-01

    Full Text Available Based on the spectral expansion of Euler correlation of the carrier medium the a closed system of functional equations for the Lagrange spectra of heavy inertial particles and the velocity fluctuations of the carrier medium on the particle trajectory have been obtained. To split the fourth moments the approximation of quasinormality and velocity fluctuations of particles is performed by a random Gaussian process. The approximate self-consistent method is proposed for solving the resulting system of functional equations. The influence of the particle inertia, the velocity of the averaged slip and microstructure of velocity fluctuations of the medium on the parameters of the chaotic motion of an impurity has been studied. It is shown that the difference in integral time scales of Eulerian and Lagrangian correlations is associated with the spatial microstructure of velocity fluctuations of the medium. It is established that in the absence of mass forces, the coefficient of the stationary diffusion of inertial particles is always greater than the diffusion coefficient of inertialess impurity. The dependence of the turbulent diffusion coefficient of particles impurity on the structural parameter of turbulence has been illustrated. The spectrum of Euler correlations of medium velocity fluctuations is modeled by Karman distributions. The influence of the particle inertia, the velocity of the averaged slip and microstructure of velocity fluctuations of the medium on the parameters of the chaotic motion of an impurity has been studied. It is shown that the difference in integral time scales of Eulerian and Lagrangian correlations is associated with the spatial microstructure of velocity fluctuations of the medium. It is established that in the absence of mass forces, the coefficient of the stationary diffusion of inertial particles is always larger than the diffusion coefficient of inertialess impurity. The dependence of the turbulent diffusion

  6. A Rather Empty World: The Many Faces of Distance and the Persistent Resistence to International Trade

    NARCIS (Netherlands)

    Linders, G.J.M.

    2008-01-01

    Despite the rapid growth of world trade over the past several decades, international trade patterns remain very much affected by high trade costs. In this paper, we emphasize the importance of distance between countries in a proper explanation of the persistent resistance to trade. We find that both

  7. Comparative Study Between Internal Ohmic Resistance and Capacity for Battery State of Health Estimation

    Directory of Open Access Journals (Sweden)

    M. Nisvo Ramadan

    2015-12-01

    Full Text Available In order to avoid battery failure, a battery management system (BMS is necessary. Battery state of charge (SOC and state of health (SOH are part of information provided by a BMS. This research analyzes methods to estimate SOH based lithium polymer battery on change of its internal resistance and its capacity. Recursive least square (RLS algorithm was used to estimate internal ohmic resistance while coloumb counting was used to predict the change in the battery capacity. For the estimation algorithm, the battery terminal voltage and current are set as the input variables. Some tests including static capacity test, pulse test, pulse variation test and before charge-discharge test have been conducted to obtain the required data. After comparing the two methods, the obtained results show that SOH estimation based on coloumb counting provides better accuracy than SOH estimation based on internal ohmic resistance. However, the SOH estimation based on internal ohmic resistance is faster and more reliable for real application

  8. High temperature diffusion induced liquid phase joining of a heat resistant alloy

    International Nuclear Information System (INIS)

    Wikstrom, N.P.; Egbewande, A.T.; Ojo, O.A.

    2008-01-01

    Transient liquid phase bonding (TLP) of a nickel base superalloy, Waspaloy, was performed to study the influence of holding time and temperature on the joint microstructure. Insufficient holding time for complete isothermal solidification of liquated insert caused formation of eutectic-type microconstituent along the joint centerline region in the alloy. In agreement with prediction by conventional TLP diffusion models, an increase in bonding temperature for a constant gap size, resulted in decrease in the time, t f, required to form a eutectic-free joint by complete isothermal solidification. However, a significant deviation from these models was observed in specimens bonded at and above 1175 deg. C. A reduction in isothermal solidification rate with increased temperature was observed in these specimens, such that a eutectic-free joint could not be achieved by holding for a time period that produced complete isothermal solidification at lower temperatures. Boron-rich particles were observed within the eutectic that formed in the joints prepared at the higher temperatures. An overriding effect of decrease in boron solubility relative to increase in its diffusivity with increase in temperature, is a plausible important factor responsible for the reduction in isothermal solidification rate at the higher bonding temperatures

  9. Thermal resistance of a convectively cooled plate with applied heat flux and variable internal heat generation

    International Nuclear Information System (INIS)

    Venkataraman, N.S.; Cardoso, H.P.; Oliveira Filho, O.B. de

    1981-01-01

    The conductive heat transfer in a rectangular plate with nonuniform internal heat generation, with one end convectively cooled and a part of the opposite end subjected to external heat flux is considered. The remaining part of this end as well as the other two sides are thermally insulated. The governing differential equation is solved by a finite difference scheme. The variation of the thermal resistance with Biot modulus, the plate geometry, the internal heat generation parameter and the type of profile of internal heat generation is discussed. (author) [pt

  10. Conference Report: Environmental Protection in the Global Twentieth Century: International Organizations, Networks and Diffusion of Ideas and Policies

    DEFF Research Database (Denmark)

    Meyer, Jan-Henrik

    the environment. Notably, IOs were central forums for negotiating and placing environmental protection on the international political agenda. It is widely assumed that 1972 – the year of the first UN conference on the human environment in Stockholm and of the publication of the Club of Rome report "Limits...... entrepreneurs, selecting, defining, diffusing and translating ideas about the environment in the course of the twentieth century? Secondly, which structural conditions facilitated – and at times inhibited – the diffusion or transfer of policy ideas? It can safely be assumed that the embedding of IOs in national...... and influential individuals – who transmitted and translated environmental ideas from the OECD Environment Committee in the early 1970s to the Brundtland Commission in the 1980s. The latter sought to overcome the apparent contradictions between developmental and environmental goals, advocating the notion...

  11. Structure evolution of multilayer materials of heat-resistant intermetallic compounds under the influence of temperature in the process of diffusion welding under pressure and their mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Korzhov, Valeriy P.; Karpov, Michael I.; Prokhorov, Dmitriy V. [Institute of Solid State Physics, Russian Academy of Sciences, Chernogolovka (Russian Federation)

    2013-07-01

    Multilayer materials of high-resistant intermetallic compounds of some transition metals with aluminum and silicon were obtained by diffusion welding of packages, collected from a large number of the respective foils, such as niobium and aluminum. Materials of intermetallics with silicon were obtained by the welding of packages built from metal foils with Si-coating. The change in the structure according to the temperature of the welding was studied, and the high-temperature bending strength was determined. Key words: multilayer composite, high-resistant material, intermetallic compound, diffusion welding, package rolling, layered structure, bending strength.

  12. Antibiotic susceptibility of methicillin-resistant staphylococci (MRS) of food origin: A comparison of agar disc diffusion method and a commercially available miniaturized test.

    Science.gov (United States)

    Buzón-Durán, Laura; Capita, Rosa; Alonso-Calleja, Carlos

    2018-06-01

    Methicillin-resistant staphylococci (MRS) are a major concern to public and animal health. Thirty MRS (Staphylococcus aureus, S. cohnii, S. epidermidis, S. haemolyticus, S. hominis, S. lentus, S. lugdunensis, S. sciuri, and S. xylosus) isolates from meat and poultry preparations were tested for antimicrobial susceptibility to 11 antimicrobials (belonging to seven different categories) of clinical significance using both the standard agar disc diffusion method and a commercially available miniaturized system (Sensi Test Gram-positive). It is worth stressing that 16 isolates (53.33%) exhibited an extensively drug-resistant phenotype (XDR). The average number of resistances per strain was 4.67. These results suggest that retail meat and poultry preparations are a likely vehicle for the transmission of multi-drug resistant MRS. Resistance to erythromycin was the commonest finding (76.67% of strains), followed by tobramycin, ceftazidime (66.67%), ciprofloxacin (56.67%) and fosfomycin (53.33%). An agreement (kappa coefficient) of 0.64 was found between the two testing methods. Using the agar disc diffusion as the reference method, the sensitivity, specificity and accuracy of the miniaturized test were 98.44%, 69.44% and 83.33%, respectively. Most discrepancies between the two methods were due to isolates that were susceptible according to the disc diffusion method but resistant according to the miniaturized test (false positives). Copyright © 2017. Published by Elsevier Ltd.

  13. Ideal and resistive MHD stability of internal kink modes in circular and shaped tokamaks

    International Nuclear Information System (INIS)

    Bondeson, A.; Luetjens, H.; Vlad, G.

    1992-01-01

    Recent results for the MHD stability of internal kink modes in tokamaks are reviewed. In general, ideal stability is more restrictive than the conventionally cited limit β p p is the poloidal beta at the q = 1 surface). This holds, in particular, for shaped equilibria, where low shear in combination with elliptic shaping can drastically reduce the pressure limit. Also in resistive MHD, interchange effects are frequently destabilizing, and resistive stability at β p ≥0.05 is achieved, for circular section, only with a very restricted class of current profiles, and not at all for JET-shaped cross section. (author) 9 figs., 24 refs

  14. Online junction temperature measurement via internal gate resistance during turn-on

    DEFF Research Database (Denmark)

    Baker, Nick; Munk-Nielsen, Stig; Liserre, Marco

    2014-01-01

    A new method for junction temperature measurement of power semiconductor switches is presented. The measurement exploits the temperature dependent resistance of the temperature sensitive electrical parameter (TSEP): the internal gate resistance. This dependence can be observed during the normal...... switching transitions of an IGBT or MOSFET, and as a result the presented method uses the integral of the gate voltage during the turn-on delay. A measurement circuit can be integrated into a gate driver with no modification to converter or gate driver operation and holds significant advantages over other...

  15. Investigation of oxidation resistance of Ni-Ti film used as oxygen diffusion barrier layer

    International Nuclear Information System (INIS)

    Liu, B.T.; Yan, X.B.; Zhang, X.; Zhou, Y.; Guo, Y.N.; Bian, F.; Zhang, X.Y.

    2009-01-01

    Ni-Ti films prepared at 10 W and 70 W by rf magnetron sputtering are investigated as the oxygen diffusion barrier layer, it is found that crystallinity of Ni-Ti film does not greatly depend on the deposition power. X-ray photoelectron spectroscopy indicates that Ni is still in the form of metallic state from the binding energies of both Ni 2p 3/2 and Ni 2p 1/2 spectra for the sample with 10 W prepared Ni-Ti, however, Ni is oxidized for 70 W prepared Ni-Ti film. Moreover, the (La 0.5 Sr 0.5 )CoO 3 /Pb(Zr 0.40 Ti 0.60 )O 3 /(La 0.5 Sr 0.5 )CoO 3 capacitor grown on high power prepared Ni-Ti film is leaky, however, the capacitor on low power prepared Ni-Ti film possesses very promising physical properties (i.e. remnant polarization of ∼27 μC/cm 2 at 5 V and maximum dielectric constant of 940). Leakage current density of the capacitor grown on low power prepared Ni-Ti film is further investigated, it meets ohmic behavior ( 1.0 V).

  16. Method for producing components with internal architectures, such as micro-channel reactors, via diffusion bonding sheets

    Science.gov (United States)

    Alman, David E [Corvallis, OR; Wilson, Rick D [Corvallis, OR; Davis, Daniel L [Albany, OR

    2011-03-08

    This invention relates to a method for producing components with internal architectures, and more particularly, this invention relates to a method for producing structures with microchannels via the use of diffusion bonding of stacked laminates. Specifically, the method involves weakly bonding a stack of laminates forming internal voids and channels with a first generally low uniaxial pressure and first temperature such that bonding at least between the asperites of opposing laminates occurs and pores are isolated in interfacial contact areas, followed by a second generally higher isostatic pressure and second temperature for final bonding. The method thereby allows fabrication of micro-channel devices such as heat exchangers, recuperators, heat-pumps, chemical separators, chemical reactors, fuel processing units, and combustors without limitation on the fin aspect ratio.

  17. Experimental Investigation on the Internal Resistance of Lithium Iron Phosphate Battery Cells during Calendar Ageing

    DEFF Research Database (Denmark)

    Stroe, Daniel Ioan; Swierczynski, Maciej Jozef; Stan, Ana-Irina

    2013-01-01

    Lithium-ion batteries are increasingly considered for a wide area of applications because of their superior characteristics in comparisons to other energy storage technologies. However, at present, Lithium-ion batteries are expensive storage devices and consequently their ageing behavior must...... be known in order to estimate their economic viability in different application. The ageing behavior of Lithium-ion batteries is described by the fade of their discharge capacity and by the decrease of their power capability. The capability of a Lithium-ion battery to deliver or to absorb a certain power...... is directly related to its internal resistance. This work aims to investigate the dependency of the internal resistance of lithium-ion batteries on the storage temperature and on the storage time. For this purpose, accelerated ageing calendar lifetime tests were carried out over a period of one year. Based...

  18. Influence of resistivity on energetic trapped particle-induced internal kink modes

    International Nuclear Information System (INIS)

    Biglari, H.; Chen, L.

    1986-01-01

    The influence of resistivity on energetic trapped particle-induced internal kink modes, dubbed ''fishbones'' in the literature, is explored. A general dispersion relation, which recovers the ideal theory in its appropriate limit, is derived and analyzed. An important implication of the theory for present generation fusion devices such as the Joint European Torus [Plasma Physics and Controlled Nuclear Fusion Research (IAEA, London, 1984), Vol I, p.11] is that they will be stable to fishbone activity

  19. Resistance to Internal Damage and Scaling of Concrete Air Entrained By Microspheres

    Science.gov (United States)

    Molendowska, Agnieszka; Wawrzenczyk, Jerzy

    2017-10-01

    This paper report the test results of high strength concrete produced with slag cement and air entrained with polymer microspheres in three diameters. The study focused on determining the effects of the microsphere size and quantity on the air void structure and resistance to internal cracking and scaling of the concrete. The resistance to internal cracking was determined in compliance with the requirements of the modified ASTM C666 A method on beam specimens. The scaling resistance in a 3% NaCl solution was determined using the slab test in accordance with PKN-CEN/TS 12390-9:2007. The air void structure parameters were determined to PN-EN 480-11:1998. The study results indicate that the use of microspheres is an effective air entrainment method providing very good air void structure parameters. The results show high freeze-thaw durability of polymer microsphere-based concrete in exposure class XF3. The scaling resistance test confirms that it is substantially more difficult to protect concrete against scaling in the presence of the 3% NaCl solution (exposure class XF4). Concrete scaling is a complex phenomenon controlled by a number of independent factors.

  20. Insulin receptor internalization defect in an insulin-resistant mouse melanoma cell line

    International Nuclear Information System (INIS)

    Androlewicz, M.J.; Straus, D.S.; Brandenburg, D.F.

    1989-01-01

    Previous studies from this laboratory demonstrated that the PG19 mouse melanoma cell line does not exhibit a biological response to insulin, whereas melanoma x mouse embryo fibroblast hybrids do respond to insulin. To investigate the molecular basis of the insulin resistance of the PG19 melanoma cells, insulin receptors from the insulin-resistant melanoma cells and insulin-sensitive fibroblast x melanoma hybrid cells were analyzed by the technique of photoaffinity labeling using the photoprobe 125 I-NAPA-DP-insulin. Photolabeled insulin receptors from the two cell types have identical molecular weights as determined by SDS gel electrophoresis under reducing and nonreducing conditions, indicating that the receptors on the two cell lines are structurally similar. Insulin receptor internalization studies revealed that the hybrid cells internalize receptors to a high degree at 37 degree C, whereas the melanoma cells internalize receptors to a very low degree or not at all. The correlation between ability to internalize insulin receptors and sensitivity to insulin action in this system suggests that uptake of the insulin-receptor complex may be required for insulin action in these cells. Insulin receptors from the two cell lines autophosphorylate in a similar insulin-dependent manner both in vitro and in intact cells, indicating that insulin receptors on the melanoma and hybrid cells have functional tyrosine protein kinase activity. Therefore, the block in insulin action in the PG19 melanoma cells appears to reside at a step beyond insulin-stimulated receptor autophosphorylation

  1. Ocular Adnexal Diffuse Large B-cell LymphomaA Multicenter International Study

    DEFF Research Database (Denmark)

    Munch-Petersen, Helga D; Rasmussen, Peter K; Coupland, Sarah E

    2015-01-01

    : This retrospective international cooperative study involved 6 eye cancer centers. During 30 years, 106 patients with OA-DLBCL were identified, and 6 were excluded from the study. The median follow-up period was 52 months. MAIN OUTCOMES AND MEASURES: Overall survival, disease-specific survival (DSS), and progression...

  2. The status of proliferation resistance evaluation methodology development in GEN IV international forum

    International Nuclear Information System (INIS)

    Inoue, Naoko; Kawakubo, Yoko; Seya, Michio; Suzuki, Mitsutoshi; Kuno, Yusuke; Senzaki, Masao

    2010-01-01

    The Generation IV Nuclear Energy Systems International Forum (GIF) Proliferation Resistance and Physical Protection Working Group (PR and PP WG) was established in December 2002 in order to develop the PR and PP evaluation methodology for GEN IV nuclear energy systems. The methodology has been studied and established by international consensus. The PR and PP WG activities include development of the measures and metrics; establishment of the framework of PR and PP evaluation, the demonstration study using Example Sodium Fast Reactor (ESFR), which included the development of three evaluation approaches; the Case Study using ESFR and four kinds of threat scenarios; the joint study with GIF System Steering Committees (SSCs) of the six reactor design concepts; and the harmonization study with the IAEA's International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO). This paper reviews the status of GIF PR and PP studies and identifies the challenges and directions for applying the methodology to evaluate future nuclear energy systems in Japan. (author)

  3. Diffuse Reflectance Spectroscopy (DRS) of radiation-induced re-oxygenation in sensitive and resistant head and neck tumor xenografts

    Science.gov (United States)

    Dadgar, Sina; Rodríguez Troncoso, Joel; Rajaram, Narasimhan

    2018-02-01

    Currently, anatomical assessment of tumor volume performed several weeks after completion of treatment is the clinical standard to determine whether a cancer patient has responded to a treatment. However, functional changes within the tumor could potentially provide information regarding treatment resistance or response much earlier than anatomical changes. We have used diffuse reflectance spectroscopy to assess the short and long-term re-oxygenation kinetics of a human head and neck squamous cell carcinoma xenografts in response to radiation therapy. First, we injected UM-SCC-22B cell line into the flank of 50 mice to grow xenografts. Once the tumor volume reached 200 mm3 (designated as Day 1), the mice were distributed into radiation and control groups. Members of radiation group underwent a clinical dose of radiation of 2 Gy/day on Days 1, 4, 7, and 10 for a cumulative dose of 8 Gy. DRS spectra of these tumors were collected for 14 days during and after therapy, and the collected spectra of each tumor were converted to its optical properties using a lookup table-base inverse model. We found statistically significant differences in tumor growth rate between two groups which is in indication of the sensitivity of this cell line to radiation. We further acquired significantly different contents of hemoglobin and scattering magnitude and size in two groups. The scattering has previously been associated with necrosis. We furthermore found significantly different time-dependent changes in vascular oxygenation and tumor hemoglobin concentration in post-radiation days.

  4. Spatial Variation of Diapycnal Diffusivity Estimated From Seismic Imaging of Internal Wave Field, Gulf of Mexico

    OpenAIRE

    Dickinson, Nicholas; White, Nicholas Jeremiah; Caulfield, Colm-cille Patrick

    2017-01-01

    Bright reflections are observed within the upper 1000~m of the water column along a seismic reflection profile that traverses the northern margin of the Gulf of Mexico. Independent hydrographic calibration demonstrates that these reflections are primarily caused by temperature changes associated with different water masses that are entrained into the Gulf along the Loop Current. The internal wave field is analyzed by automatically tracking 1171 reflections, each of which is greater th...

  5. The macrodynamics of international migration as a sociocultural diffusion process. Part A: theory.

    Science.gov (United States)

    Diamantides, N D

    1992-11-01

    "This study formulates a model of the macrodynamics of international migration using a differential equation to capture the push-pull forces that propel it. The model's architecture rests on the functioning of information feedback between settled friends and family at the destination and potential emigrants at the origin." The author tests the model using data on Greek emigration to the United States since 1820 and on total emigration from Cyprus since 1946. excerpt

  6. Evaluation of the Internal and Borehole Resistances during Thermal Response Tests and Impact on Ground Heat Exchanger Design

    Directory of Open Access Journals (Sweden)

    Louis Lamarche

    2017-12-01

    Full Text Available The main parameters evaluated with a conventional thermal response test (TRT are the subsurface thermal conductivity surrounding the borehole and the effective borehole thermal resistance, when averaging the inlet and outlet temperature of a ground heat exchanger with the arithmetic mean. This effective resistance depends on two resistances: the 2D borehole resistance (Rb and the 2D internal resistance (Ra which is associated to the short-circuit effect between pipes in the borehole. This paper presents a field method to evaluate these two components separately. Two approaches are proposed. In the first case, the temperature at the bottom of the borehole is measured at the same time as the inlet and outlet temperatures as done in a conventional TRT. In the second case, different flow rates are used during the experiment to infer the internal resistance. Both approaches assumed a predefined temperature profile inside the borehole. The methods were applied to real experimental tests and compared with numerical simulations. Interesting results were found by comparison with theoretical resistances calculated with the multipole method. The motivation for this work is evidenced by analyzing the impact of the internal resistance on a typical geothermal system design. It is shown to be important to know both resistance components to predict the variation of the effective resistance when the flow rate and the height of the boreholes are changed during the design process.

  7. Proceedings of the international information exchange meeting on diffusion phenomena in bentonite and rock. Aiming at the safety assessment of the geological disposal

    International Nuclear Information System (INIS)

    Sato, Haruo; Hatanaka, Koichiro

    2009-12-01

    The international information exchange meeting on diffusion phenomena in bentonite and rock was held at Horonobe Underground Research Center on 18th July, 2006. This meeting was hosted by Japan Atomic Energy Agency (JAEA) and supported by Hokkaido University and Radioactive Waste Management Funding and Research Center (RWMC). Totally 18 scientists who are specialists of diffusion participated from Finland (VTT) and Japan (7 research organizations) in the meeting. 6 presentations were made on recent research activities and outputs on diffusion phenomena in bentonite and rock. The 6 papers are indexed individually. (J.P.N.)

  8. A mechanical-electrical finite element method model for predicting contact resistance between bipolar plate and gas diffusion layer in PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Xinmin; Liu, Dong' an; Peng, Linfa [State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Ni, Jun [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109-2125 (United States)

    2008-07-15

    Contact resistance between the bipolar plate (BPP) and the gas diffusion layer (GDL) plays a significant role on the power loss in a proton exchange membrane (PEM) fuel cell. There are two types of contact behavior at the interface of the BPP and GDL, which are the mechanical one and the electrical one. Furthermore, the electrical contact behavior is dependent on the mechanical one. Thus, prediction of the contact resistance is a coupled mechanical-electrical problem. The current FEM models for contact resistance estimation can only simulate the mechanical contact behavior and moreover they are based on the assumption that the contact surface is equipotential, which is not the case in a real BPP/GDL assembly due to the round corner and margin of the BPP. In this study, a mechanical-electrical FEM model was developed to predict the contact resistance between the BPP and GDL based on the experimental interfacial contact resistivity. At first, the interfacial contact resistivity was obtained by experimentally measuring the contact resistance between the GDL and a flat graphite plate of the same material and processing conditions as the BPP. Then, with the interfacial contact resistivity, the mechanical and electrical contact behaviors were defined and the potential distribution of the BPP/GDL assembly was analyzed using the mechanical-electrical FEM model. At last, the contact resistance was calculated according to the potential drop and the current of the contact surface. The numerical results were validated by comparing with those of the model reported previously. The influence of the round corner of the BPP on the contact resistance was also studied and it is found that there exists an optimal round corner that can minimize the contact resistance. This model is beneficial in understanding the mechanical and electrical contact behaviors between the BPP and GDL, and can be used to predict the contact resistance in a new BPP/GDL assembly. (author)

  9. International workshop on insecticide resistance in vectors of arboviruses, December 2016, Rio de Janeiro, Brazil.

    Science.gov (United States)

    Corbel, Vincent; Fonseca, Dina M; Weetman, David; Pinto, João; Achee, Nicole L; Chandre, Fabrice; Coulibaly, Mamadou B; Dusfour, Isabelle; Grieco, John; Juntarajumnong, Waraporn; Lenhart, Audrey; Martins, Ademir J; Moyes, Catherine; Ng, Lee Ching; Raghavendra, Kamaraju; Vatandoost, Hassan; Vontas, John; Muller, Pie; Kasai, Shinji; Fouque, Florence; Velayudhan, Raman; Durot, Claire; David, Jean-Philippe

    2017-06-02

    Vector-borne diseases transmitted by insect vectors such as mosquitoes occur in over 100 countries and affect almost half of the world's population. Dengue is currently the most prevalent arboviral disease but chikungunya, Zika and yellow fever show increasing prevalence and severity. Vector control, mainly by the use of insecticides, play a key role in disease prevention but the use of the same chemicals for more than 40 years, together with the dissemination of mosquitoes by trade and environmental changes, resulted in the global spread of insecticide resistance. In this context, innovative tools and strategies for vector control, including the management of resistance, are urgently needed. This report summarizes the main outputs of the first international workshop on Insecticide resistance in vectors of arboviruses held in Rio de Janeiro, Brazil, 5-8 December 2016. The primary aims of this workshop were to identify strategies for the development and implementation of standardized insecticide resistance management, also to allow comparisons across nations and across time, and to define research priorities for control of vectors of arboviruses. The workshop brought together 163 participants from 28 nationalities and was accessible, live, through the web (> 70,000 web-accesses over 3 days).

  10. The macrodynamics of international migration as a socio-cultural diffusion process. Part B: applications.

    Science.gov (United States)

    Diamantides, N D

    1992-12-01

    "This study formulates a model of the macrodynamics of international migration using a differential equation to capture the push-pull forces that propel it. The model's architecture rests on the functioning of information feedback between settled friends and family at the destination and potential emigrants at the origin.... Two specific paradigms of diverse nature serve to demonstrate the model's tenets and pertinence, one being Greek emigration to the United States since 1820, and the other total out-migration from Cyprus since statehood (1946)." excerpt

  11. Degradation Behavior of Lithium-Ion Batteries during Calendar Ageing – The Case of the Internal Resistance Increase

    DEFF Research Database (Denmark)

    Stroe, Daniel-Ioan; Swierczynski, Maciej Jozef; Kær, Søren Knudsen

    2018-01-01

    Lithium-ion batteries are regarded as the key energy storage technology for both e-mobility and stationary renewable energy storage applications. Nevertheless, the Lithium-ion batteries are complex energy storage devices, which are characterized by a complex degradation behavior, which affects both...... their capacity and internal resistance. This paper investigates, based on extended laboratory calendar ageing tests, the degradation of the internal resistance of a Lithium-ion battery. The dependence of the internal resistance increase on the temperature and state-of-charge level have been extensive studied...... and quantified. Based on the obtained laboratory results, an accurate semi-empirical lifetime model, which is able to predict with high accuracy the internal resistance increase of the Lithium-ion battery over a wide temperature range and for all state-of-charge levels was proposed and validated....

  12. Tumor necrosis factor: specific binding and internalization in sensitive and resistant cells

    International Nuclear Information System (INIS)

    Tsujimoto, M.; Yip, Y.K.; Vilcek, J.

    1985-01-01

    Highly purified, Escherichia coli-derived recombinant human tumor necrosis factor (TNF) was labeled with 125 I and employed to determine receptor binding, internalization, and intracellular degradation in murine L929 cells (highly sensitive to the cytotoxic action of TNF) and in diploid human FS-4 cells (resistant to TNF cytotoxicity). 125 I-labeled TNF bound specifically to high-affinity receptors on both L929 and FS-4 cells. Scatchard analysis of the binding data indicated the presence of 2200 binding sites per L929 cell and 7500 binding sites per FS-4 cell. The calculated dissociation constants are 6.1 x 10 -10 M and 3.2 x 10 -10 M for L929 and FS-4 cells, respectively. In both L929 and FS-4 cells, incubation at 37 0 C resulted in a rapid internalization of the bulk of the cell-bound TNF, followed by the appearance of trichloroacetic acid-soluble 125 I radioactivity in the tissue culture medium, due to degradation of TNF. Degradation but not cellular uptake of TNF was inhibited in the presence of chloroquine (an inhibitor of lysosomal proteases) in both L929 and FS-4 cells, suggesting that degradation occurs intracellularly, probably within lysosomes. These results show that resistance of FS-4 cells to TNF cytotoxicity is not due to a lack of receptors or their inability to internalize and degrade TNF

  13. Synergy of β-Lactams with Vancomycin against Methicillin-Resistant Staphylococcus aureus: Correlation of Disk Diffusion and Checkerboard Methods.

    Science.gov (United States)

    Sy, Cheng Len; Huang, Tsi-Shu; Chen, Chii Shiang; Chen, Yao-Shen; Tsai, Hung-Chin; Wann, Shue-Renn; Wu, Kuan-Sheng; Chen, Jui-Kuang; Lee, Susan Shin-Jung; Liu, Yung-Ching

    2016-03-01

    Modified disk diffusion (MDD) and checkerboard tests were employed to assess the synergy of combinations of vancomycin and β-lactam antibiotics for 59 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Mu50 (ATCC 700699). Bacterial inocula equivalent to 0.5 and 2.0 McFarland standard were inoculated on agar plates containing 0, 0.5, 1, and 2 μg/ml of vancomycin. Oxacillin-, cefazolin-, and cefoxitin-impregnated disks were applied to the surface, and the zones of inhibition were measured at 24 h. The CLSI-recommended checkerboard method was used as a reference to detect synergy. The MICs for vancomycin were determined using the Etest method, broth microdilution, and the Vitek 2 automated system. Synergy was observed with the checkerboard method in 51% to 60% of the isolates when vancomycin was combined with any β-lactam. The fractional inhibitory concentration indices were significantly lower in MRSA isolates with higher vancomycin MIC combinations (P synergy in MRSA isolates with bacterial inocula equivalent to McFarland standard 0.5 were 33.0% and 62.5% for oxacillin, 45.1% and 52.4% for cefazolin, and 43.1% and 52.4% for cefoxitin when combined with 0.5 and 2 μg/ml of vancomycin, respectively. Based on our study, the simple MDD method is not recommended as a replacement for the checkerboard method to detect synergy. However, it may serve as an initial screening method for the detection of potential synergy when it is not feasible to perform other labor-intensive synergy tests. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  14. An innovation diffusion model of a local electricity network that is influenced by internal and external factors

    Science.gov (United States)

    Hattam, Laura; Greetham, Danica Vukadinović

    2018-01-01

    Haynes et al. (1977) derived a nonlinear differential equation to determine the spread of innovations within a social network across space and time. This model depends upon the imitators and the innovators within the social system, where the imitators respond to internal influences, whilst the innovators react to external factors. Here, this differential equation is applied to simulate the uptake of a low-carbon technology (LCT) within a real local electricity network that is situated in the UK. This network comprises of many households that are assigned to certain feeders. Firstly, travelling wave solutions of Haynes' model are used to predict adoption times as a function of the imitation and innovation influences. Then, the grid that represents the electricity network is created so that the finite element method (FEM) can be implemented. Next, innovation diffusion is modelled with Haynes' equation and the FEM, where varying magnitudes of the internal and external pressures are imposed. Consequently, the impact of these model parameters is investigated. Moreover, LCT adoption trajectories at fixed feeder locations are calculated, which give a macroscopic understanding of the uptake behaviour at specific network sites. Lastly, the adoption of LCTs at a household level is examined, where microscopic and macroscopic approaches are combined.

  15. SUS 321 HTB boiler tubing with fire grained internal surface resistant to steam-induced oxidation

    International Nuclear Information System (INIS)

    Kanero, Takahiro; Minami, Yuusuke; Kodera, Toshihide

    1981-01-01

    Considerable amount of scale is produced by high temperature steam on the austenitic stainless steel tubes used for the superheaters and reheaters of large boilers for power generation. The scale of outer layer separates off due to the thermal stress at the time of starting-up and stopping, and causes the blocking of pipes and the erosion of turbine blades. Following the increase of nuclear power generation, large boilers are used for medium load, accordingly it is expected that the troubles like these increase. In this paper, the manufacturing method and the properties of SUS 321 HTB with fine grain internal surface are reported, which was developed to reduce the rate of growth of scale and to prevent the separation of scale. In order to prevent the separation of scale from austenitic stainless steel tubes, the reduction of scale thickness, surface treatment such as chrome plating, the use of alloys with excellent oxidation resistance, the formation of chrome-rich film rapidly, the heat treatment of cold-worked tubes and so on were carried out. The nitrification of SUS 321 H steel brought about two-phase structure of the fine grain internal surface with excellent oxidation resistance and the rest of coarse grains with high creep strength. (Kako, I.)

  16. Impact of Air Entraining Method on the Resistance of Concrete to Internal Cracking

    Science.gov (United States)

    Wawrzeńczyk, Jerzy; Molendowska, Agnieszka

    2017-10-01

    This paper presents the test results of air entrained concrete mixtures made at a constant W/C ratio of 0.44. Three different air entraining agents were used: polymer microspheres, glass microspheres and a conventional air entraining admixture. The aim of this study was to compare the effectiveness of the air entraining methods. Concrete mixture tests were performed for consistency (slump test), density and, in the case of AEA series, air content by pressure method. Hardened concrete tests were performed for compressive strength, water absorption, resistance to chloride ingress, and freeze-thaw durability - resistance to internal cracking tests were conducted in accordance with PN-88/B-06250 on cube specimens and with the modified ASTM C666 A test method on beam specimens; porosity characteristics (A, A300, \\bar L) were determined to PN-EN 480-11:1998. No significant mass and length changes were recorded for the concrete air entrained with the conventional methods or with polymer microspheres. The results indicate that polymer microspheres are a very good alternative to traditional air entraining methods for concrete, providing effective air entrainment and protection from freezing and thawing. The glass microsphere-based concretes showed insufficient freeze-thaw resistance. The test results indicate that both the conventional methods (AEA) and the air entrainment by polymer microspheres are effective air entraining methods. It has to be noted that in the case of the use of polymer microspheres, a comparable value of \\bar L and a very good freeze-thaw resistance can be achieved at a noticeably lower air and micropore contents and at lower strength loss.

  17. International Collaboration: the Virtuous Cycle of Low Carbon Innovation and Diffusion. An Analysis of Solar Photovoltaic, Concentrating Solar Power and Carbon Capture and Storage

    International Nuclear Information System (INIS)

    Dominique, Katheen

    2010-01-01

    International collaboration can be leveraged to accelerate the innovation and diffusion of low carbon technologies required to realize the shift to a low carbon trajectory. A collaborative approach to innovation has the potential to capture several benefits, including: pooling risks and achieving scale; knowledge sharing that accommodates competition and cooperation; the creation of a global market; facilitation of policy learning and exchange; and the alignment of technology, finance and policy. International Collaboration: the Virtuous Cycle of Low Carbon Innovation and Diffusion An Analysis of Solar Photovoltaic, Concentrating Solar Power and Carbon Capture and Storage A range of obstacles to the diffusion of low carbon technologies provides ample opportunity for international collaboration in global market creation and capacity building, expanding beyond conventional modes of technology transfer. Current collaborative efforts for carbon capture and storage, solar photovoltaic and concentrating solar power technologies are active in all stages of innovation and diffusion and involve a wide range of actors. Yet, current efforts are not sufficient to achieve the necessary level of emission mitigation at the pace required to avoid catastrophic levels of atmospheric destabilization. This analysis sets forth recommendation to scale up current endeavors and create new ones. The analysis begins by describing the fundamental characteristics of innovation and diffusion processes that create opportunities for international collaboration. It then illustrates a broad array of on-going collaborative activities, depicting how these efforts contribute to innovation and diffusion. Finally, highlighting the gap between the current level of collaborative activities and technology targets deemed critical for emission mitigation, the report sets forth several recommendations to build on current efforts and construct new endeavors

  18. Control of the Resistive Wall Mode with Internal Coils in the DIII-D Tokamak

    International Nuclear Information System (INIS)

    Okabayashi, M.; Bialek, J.; Bondeson, A.

    2005-01-01

    New coils were installed inside the vacuum vessel of the DIII-D device for producing nonaxisymmetric magnetic fields. These 'Internal-Coils' are predicted to stabilize the Resistive Wall Mode (RWM) branch of the long-wavelength external kink mode with plasma beta close to the ideal wall limit. Feedback using these new Internal-Coils was found to be more effective when compared with using the External-Coils located outside the vacuum vessel, because the location inside the vessel allows faster response and their geometry also couples better to the helical mode structure. A proper choice of feedback gain increased the plasma beta above the no-wall limit to C β ≥ 0.9, where C β is a measure of achievable beta above no-wall limit defined as (β-β no-wall.limit )/(β ideal.wall.limit )-)/(β no.wall.limit ). The feedback system with Internal-Coils can suppress the RWM up to the normalized growth rate γτ w > or ∼ 10 (τ w is the resistive flux penetration time of the wall). The feedback-driven dynamic error field correction helps to stabilize the RWM by reducing the rotational drag for Ω rot > Ω crit , where Ω rot is the angular rotation frequency of plasma and Ω crit is the critical value for the rotational stabilization. When Ω rot crit /2, the feedback system must stabilize the RWM mainly through direct magnetic control of the mode. The estimated Ω crit /Ω A is ∼ 2.5% by the MARS-F code analysis with experimentally observed profiles, where /Ω A is the Alfven angular rotational frequency at q 2 surface. The MARS-F code also predicts that for successful RWM magnetic feedback control the power supply characteristic time should be a fraction of the growth time of the targeted RWM. (author)

  19. TOR induced resistance to toxic adenosine analogs in Leishmania brought about by the internalization and degradation of the adenosine permease

    Science.gov (United States)

    Detke, Siegfried

    2007-01-01

    TOR is an atypical multidrug resistance protein present in the human protozoan parasite, Leishmania. Resistance to the toxic adenosine analog tubercidin was brought about by redirecting the adenosine permease from the plasma membrane to the multivesicular tubule lysosome. The cells became resistant to tubercidin because they were unable to take up and accumulate this toxic purine. The domain which was recognized by TOR in this internalization pathway was identified by expressing portions of this transporter in Leishmania and assessing whether they were capable of hindering the multidrug resistance capability of TOR. This approach identified the adenosine permease region spanning Met289 to Trp305. This region was also the epitope recognized by the internalization mechanism. An internal deletion mutant lacking Met289-Trp305 was functionally active but could no longer be internalized in cells with high TOR levels. The internalization and altered trafficking of the adenosine permease by TOR was observed in yeast and human embryonic kidney cells co-expressing these two Leishmania proteins indicating that the internalization process was conserved in evolutionary diverse organisms. The inability of Saccharomyces with a temperature sensitive ubiquitin ligase to internalize adenosine permease suggested that ubiquitination was involved in this altered trafficking. PMID:17428463

  20. Experimental study of the possibility of reducing the resistance and unevenness of output field of velocities in flat diffuser channels with large opening angles

    Science.gov (United States)

    Dmitriev, S. S.; Vasil'ev, K. E.; Mokhamed, S. M. S. O.; Gusev, A. A.; Barbashin, A. V.

    2017-11-01

    In modern combined cycle gas turbines (CCGT), when designing the reducers from the output diffuser of a gas turbine to a boiler-utilizer, wide-angle diffusers are used, in which practically from the input a flow separation and transition to jet stream regime occurs. In such channels, the energy loss in the field of velocities sharply rise and the field of velocities in the output from them is characterized by considerable unevenness that worsens the heat transfer process in the first by motion tube bundles of the boiler-utilizer. The results of experimental research of the method for reducing the energy loss and alignment of the field of velocities at the output from a flat asymmetrical diffuser channel with one deflecting wall with the opening angle of 40° by means of placing inside the channel the flat plate parallel to the deflecting wall are presented in the paper. It is revealed that, at this placement of the plate in the channel, it has a chance to reduce the energy loss by 20%, considerably align the output field of velocities, and decrease the dynamic loads on the walls in the output cross-section. The studied method of resistance reduction and alignment of the fields of velocities in the flat diffuser channels was used for optimization of the reducer from the output diffuser of the gas turbine to the boiler-utilizer of CCGT of PGU-450T type of Kaliningrad Thermal Power Plant-2. The obtained results are evidence that the configuration of the reducer installed in the PGU-450T of Kaliningrad Thermal Power Plant-2 is not optimal. It follows also from the obtained data that working-off the reducer should be necessarily conducted by the test results of the channel consisting of the model of reducer with the model of boiler-utilizer installed behind it. Application of the method of alignment of output field of velocities and reducing the resistance in the wide-angle diffusers investigated in the work made it possible—when using the known model of diffusion

  1. Study of self-compliance behaviors and internal filament characteristics in intrinsic SiOx-based resistive switching memory

    International Nuclear Information System (INIS)

    Chang, Yao-Feng; Zhou, Fei; Chen, Ying-Chen; Lee, Jack C.; Fowler, Burt

    2016-01-01

    Self-compliance characteristics and reliability optimization are investigated in intrinsic unipolar silicon oxide (SiO x )-based resistive switching (RS) memory using TiW/SiO x /TiW device structures. The program window (difference between SET voltage and RESET voltage) is dependent on external series resistance, demonstrating that the SET process is due to a voltage-triggered mechanism. The program window has been optimized for program/erase disturbance immunity and reliability for circuit-level applications. The SET and RESET transitions have also been characterized using a dynamic conductivity method, which distinguishes the self-compliance behavior due to an internal series resistance effect (filament) in SiO x -based RS memory. By using a conceptual “filament/resistive gap (GAP)” model of the conductive filament and a proton exchange model with appropriate assumptions, the internal filament resistance and GAP resistance can be estimated for high- and low-resistance states (HRS and LRS), and are found to be independent of external series resistance. Our experimental results not only provide insights into potential reliability issues but also help to clarify the switching mechanisms and device operating characteristics of SiO x -based RS memory

  2. Diffusion of Acetic Acid Across Oil/Water Interface in Emulsification-Internal Gelation Process for Preparation of Alginate Gel Beads

    Institute of Scientific and Technical Information of China (English)

    LIU Xiu-dong; YU Wei-ting; LIN Jun-zhang; MA Xiao-jun; YUAN Quan

    2007-01-01

    Alginate has been widely used in cell microencapsulation and drug delivery systems in the form of gel beads or microcapsules. Although an alternative novel emulsification-internal gelation technology has been established and both the properties and the potential applications of the beads in drug delivery systems have been studied, the mechanism has not been well understood compared with the traditional droplet method( external gelation technology). On the basis of our previous knowledge that the novel technology is composed of complicatedly consecutive processes with multistep diffusion and re action, and the diffusion of acetic acid across oil/water interface being the prerequisite that determines the occurrence and rate for the reactions and the structures and properties of final produced gel beads, a special emphasis was placed on the diffusion process. With the aid of diffusion modeling and simple experimental design, the diffusion rate constant and diffusion coefficient of acetic acid across oil/water interface were determined to be in the orders of magnitude of 10-6 and 10-16, respectively. This knowledge will be of particular importance in understanding and interpreting the formation, structure of the gel beads and the relationship between the structure and properties and guiding the preparation and quality control of the gel beads.

  3. International comparison of resistance thermometers between NMIs from Spain, Mexico and Andean countries

    Science.gov (United States)

    del Campo, D.; Ruiz, V. C.; Méndez-Lango, E.; Córdova, L.; von Borries, E.; Sánchez, C. A.; Arévalo, A.; Aguilera, B.; Guillén, E.; Cabrera, C.; Quintana, L.

    2013-09-01

    An international comparison on semi-standard Platinum Resistance Thermometers (PRTs) among the National Metrology Institutes (NMIs) of Spain, Mexico and the Andean Countries (Bolivia, Colombia, Ecuador, Peru and Venezuela) began in 2004 and was successfully completed in 2005. Two PRTs were circulated (hand carried) and compared from -40 °C up to 250 °C. The Centro Español de Metrología (Spanish NMI), CEM, was the pilot laboratory and the Centro Nacional de Metrología (Mexican NMI), CENAM, was the co-pilot laboratory. This paper shows the details of the comparison and the final results as they were presented in the approved final report of the comparison in September of 2005.

  4. An improved model for predicting electrical contact resistance between bipolar plate and gas diffusion layer in proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhiliang; Wang, Shuxin [School of Mechanical Engineering, Tianjin University, Tianjin 300072 (China); Zhou, Yuanyuan; Lin, Guosong; Hu, S. Jack [Department of Mechanical Engineering, The University of Michigan, Ann Arbor, MI 48109-2125 (United States)

    2008-07-15

    Electrical contact resistance between bipolar plates (BPPs) and gas diffusion layers (GDLs) in PEM fuel cells has attracted much attention since it is one significant part of the total contact resistance which plays an important role in fuel cell performance. This paper extends a previous model by Zhou et al. [Y. Zhou, G. Lin, A.J. Shih, S.J. Hu, J. Power Sources 163 (2007) 777-783] on the prediction of electrical contact resistance within PEM fuel cells. The original microscale numerical model was based on the Hertz solution for individual elastic contacts, assuming that contact bodies, GDL carbon fibers and BPP asperities are isotropic elastic half-spaces. The new model features a more practical contact by taking into account the bending behavior of carbon fibers as well as their anisotropic properties. The microscale single contact process is solved numerically using the finite element method (FEM). The relationship between the contact pressure and the electrical resistance at the GDL/BPP interface is derived by multiple regression models. Comparisons of the original model by Zhou et al. and the new model with experimental data show that the original model slightly overestimates the electrical contact resistance, whereas a better agreement with experimental data is observed using the new model. (author)

  5. Y-box-binding protein-1 (YB-1) promotes cell proliferation, adhesion and drug resistance in diffuse large B-cell lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Xiaobing; Wu, Yaxun [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); Wang, Yuchan [Department of Pathogen, Medical College, Nantong University, Nantong 226001, Jiangsu (China); Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226001, Jiangsu (China); Zhu, Xinghua; Yin, Haibing [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); He, Yunhua [Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong 226001, Jiangsu (China); Li, Chunsun; Liu, Yushan; Lu, Xiaoyun; Chen, Yali; Shen, Rong [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); Xu, Xiaohong, E-mail: xuxiaohongnantong@126.com [Department of Oncology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China); He, Song, E-mail: hesongnt@126.com [Department of Pathology, Affiliated Cancer Hospital of Nantong University, Nantong 226361, Jiangsu (China)

    2016-08-15

    YB-1 is a multifunctional protein, which has been shown to correlate with resistance to treatment of various tumor types. This study investigated the expression and biologic function of YB-1 in diffuse large B-cell lymphoma (DLBCL). Immunohistochemical analysis showed that the expression statuses of YB-1 and pYB-1{sup S102} were reversely correlated with the clinical outcomes of DLBCL patients. In addition, we found that YB-1 could promote the proliferation of DLBCL cells by accelerating the G1/S transition. Ectopic expression of YB-1 could markedly increase the expression of cell cycle regulators cyclin D1 and cyclin E. Furthermore, we found that adhesion of DLBCL cells to fibronectin (FN) could increase YB-1 phosphorylation at Ser102 and pYB-1{sup S102} nuclear translocation. In addition, overexpression of YB-1 could increase the adhesion of DLBCL cells to FN. Intriguingly, we found that YB-1 overexpression could confer drug resistance through cell-adhesion dependent and independent mechanisms in DLBCL. Silencing of YB-1 could sensitize DLBCL cells to mitoxantrone and overcome cell adhesion-mediated drug resistance (CAM-DR) phenotype in an AKT-dependent manner. - Highlights: • The expression statuses of YB-1 and pYB-1{sup S102} are reversely correlated with outcomes of DLBCL patients. • YB-1 promotes cell proliferation by accelerating G1/S transition in DLBCL. • YB-1 confers drug resistance to mitoxantrone in DLBCL.

  6. Introduction and Diffusion of Electronic Commerce – What is Switzerland’s position in an international comparison? Results of an empirical study

    OpenAIRE

    Harabi, Najib

    2001-01-01

    What is Switzerland’s position today with regard to the acceptance, diffusion and usage of new work forms and business methods in the economy and society? One of the most extensive international surveys of population and businesses done thus far gives well founded answers to these questions: Last year, distinguished research institutes from 10 different countries of the European Union (Denmark, Germany, France, Finland, Ireland, Italy, Netherlands, Spain, Sweden, United Kingdom) and Switzerla...

  7. Local resistance patterns to antimicrobials in internal medicine: a focused report from the REGIMEN (REGistro Infezioni in MEdicina INterna) study.

    Science.gov (United States)

    Cei, Marco; Pardelli, Riccardo; Sani, Spartaco; Mumoli, Nicola

    2014-02-01

    The treatment for infections in hospitalized patients can be summarized in the timely start of empirical therapy, followed by adjustment on the basis of isolates and microbial susceptibilities. Initial therapy may be based on international guidelines. However, to know local frequencies of bacterial and fungal strains together with patterns of drug resistance should be a better approach to therapy. REGIMEN is a retrospective observational study of all consecutive recorded bacterial and fungal isolates, collected between October 2009 and August 2011 from patients admitted in a 53-bedded ward of internal medicine of a non-teaching Italian hospital. We investigated type of samples and of microorganisms, patterns of susceptibility and resistance to antibiotics, and in-hospital mortality. A total of 504 samples were examined (244 from urine, 189 from blood and 71 from skin and various exudates). Participants were old (mean age, 83 years), and so overall mortality was high (20 %). There were high frequencies of drug resistance; only 27.9 % of urinary gram-negatives and 52.6 % of blood gram-negatives were susceptible to levofloxacin. Susceptibility profiles compatible with the presence of extended-spectrum beta-lactamases were present in 64.2 % of gram-negative strains, and 10.1 % were also resistant to carbapenems. ESKAPE organisms account for a third of all bacterial infections. Local patterns of drug resistance should influence empirical antibiotic therapy for patients admitted in internal medicine wards, where mortality is high.

  8. Comparison of real-time PCR with disk diffusion, agar screen and E-test methods for detection of methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Shariati, Laleh; Validi, Majid; Tabatabaiefar, Mohammad Amin; Karimi, Ali; Nafisi, Mohammad Reza

    2010-12-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a nosocomial pathogen. Our main objective was to compare oxacillin disk test, oxacillin E-test, and oxacillin agar screen for detection of methicillin resistance in S. aureus, using real-time PCR for mecA as the "gold standard" comparison assay. 196 S. aureus isolates were identified out of 284 Staphylococcus isolates. These isolates were screened for MRSA with several methods: disk diffusion, agar screen (6.0 μg/ml), oxacillin E-test, and real-time PCR for detection of mecA gene. Of the 196 S. aureus isolates tested, 96 isolates (49%) were mecA-positive and 100 isolates (51%) mecA-negative. All methods tested had a statistically significant agreement with real-time PCR. E-test was 100% sensitive and specific for mecA presence. The sensitivity and specificity of oxacillin agar screen method were 98 and 99%, respectively and sensitivity and specificity of oxacillin disk diffusion method were 95 and 93%, respectively. In the present study, oxacillin E-test is proposed as the best phenotypic method. For economic reasons, the oxacillin agar screen method (6.0 μg/ml), which is suitable for the detection of MRSA, is recommended due to its accuracy and low cost.

  9. Oxygen diffusion in Y sub 1 sub - sub x Pr sub x Ba sub 2 Cu sub 3 O sub 7 sub - subdelta observed by resistivity measurements

    CERN Document Server

    Diosa, J E; Mellander, B E

    1997-01-01

    In situ resistivity measurements have been used to monitor the oxygen uptake and removal for the ceramic system Y sub 1 sub - sub x Pr sub x Ba sub 2 Cu sub 3 O sub 7 sub - subdelta (YPBCO) in the temperature range 300 - 1000 K. The study of the out-diffusion of oxygen was performed by annealing the oxygenated samples in ambient air at constant heating rates. We found that, independently of x, the oxygen concentration O sub 7 sub - subdelta is preserved up to 600 K, and that oxygen diffuses out of the oxides at temperatures higher than 600 K. However, the rate of oxygen removal from PrBa sub 2 Cu sub 3 O sub 7 sub - subdelta (PBCO) is greatly reduced as compared to the rate for pure YBa sub 2 Cu sub 3 O sub 7 sub - subdelta (YBCO), and decreases with increasing x in YPBCO. The study of the in-diffusion of oxygen was performed by annealing the deoxygenated samples in ambient air at constant heating rates. We found that, independently of x, the oxygen uptake takes place in the temperature range 550 - 750 K, whe...

  10. In vivo non-thermal irreversible electroporation impact on rat liver galvanic apparent internal resistance

    International Nuclear Information System (INIS)

    Golberg, A; Laufer, S; Rabinowitch, H D; Rubinsky, B

    2011-01-01

    Non-thermal irreversible electroporation (NTIRE) is a biophysical phenomenon which involves application of electric field pulses to cells or tissues, causing certain rearrangements in the membrane structure leading to cell death. The treated tissue ac impedance changes induced by electroporation were shown to be the indicators for NTIRE efficiency. In a previous study we characterized in vitro tissue galvanic apparent internal resistance (GAIR) changes due to NTIRE. Here we describe an in vivo study in which we monitored the GAIR changes of a rat liver treated by NTIRE. Electrical pulses were delivered through the same Zn/Cu electrodes by which GAIR was measured. GAIR was measured before and for 3 h after the treatment at 15 min intervals. The results were compared to the established ac bioimpedance measurement method. A decrease of 33% was measured immediately after the NTIRE treatment and a 40% decrease was measured after 3 h in GAIR values; in the same time 40% and 47% decrease respectively were measured by ac bioimpedance analyses. The temperature increase due to the NTIRE was only 0.5 deg. C. The results open the way for an inexpensive, self-powered in vivo real-time NTIRE effectiveness measurement.

  11. In vivo non-thermal irreversible electroporation impact on rat liver galvanic apparent internal resistance

    Energy Technology Data Exchange (ETDEWEB)

    Golberg, A; Laufer, S [Center for Bioengineering in the Service of Humanity and Society, School of Computer Science and Engineering, Hebrew University of Jerusalem, Jerusalem 91904 (Israel); Rabinowitch, H D [Robert H Smith Faculty of Agriculture, Food and Environment, Robert H Smith Institute of Plant Science and Genetics in Agriculture, Hebrew University of Jerusalem, Rehovot 76 100 (Israel); Rubinsky, B, E-mail: Rabin@agri.huji.ac.il [Department of Mechanical Engineering, Graduate Program in Biophysics, University of California at Berkeley, Berkeley, CA 84720 (United States)

    2011-02-21

    Non-thermal irreversible electroporation (NTIRE) is a biophysical phenomenon which involves application of electric field pulses to cells or tissues, causing certain rearrangements in the membrane structure leading to cell death. The treated tissue ac impedance changes induced by electroporation were shown to be the indicators for NTIRE efficiency. In a previous study we characterized in vitro tissue galvanic apparent internal resistance (GAIR) changes due to NTIRE. Here we describe an in vivo study in which we monitored the GAIR changes of a rat liver treated by NTIRE. Electrical pulses were delivered through the same Zn/Cu electrodes by which GAIR was measured. GAIR was measured before and for 3 h after the treatment at 15 min intervals. The results were compared to the established ac bioimpedance measurement method. A decrease of 33% was measured immediately after the NTIRE treatment and a 40% decrease was measured after 3 h in GAIR values; in the same time 40% and 47% decrease respectively were measured by ac bioimpedance analyses. The temperature increase due to the NTIRE was only 0.5 deg. C. The results open the way for an inexpensive, self-powered in vivo real-time NTIRE effectiveness measurement.

  12. Determination of diffusion coefficients and diffusion characteristics for chlorferon and diethylthiophosphate in Ca-alginate gel beads.

    Science.gov (United States)

    Ha, Jiyeon; Engler, Cady R; Lee, Seung Jae

    2008-07-01

    Diffusion characteristics of chlorferon and diethylthiophosphate (DETP) in Ca-alginate gel beads were studied to assist in designing and operating bioreactor systems. Diffusion coefficients for chlorferon and DETP in Ca-alginate gel beads determined at conditions suitable for biodegradation studies were 2.70 x 10(-11) m(2)/s and 4.28 x 10(-11) m(2)/s, respectively. Diffusivities of chlorferon and DETP were influenced by several factors, including viscosity of the bulk solution, agitation speed, and the concentrations of diffusing substrate and immobilized cells. Diffusion coefficients increased with increasing agitation speed, probably due to poor mixing at low speed and some attrition of beads at high speeds. Diffusion coefficients also increased with decreasing substrate concentration. Increased cell concentration in the gel beads caused lower diffusivity. Theoretical models to predict diffusivities as a function of cell weight fraction overestimated the effective diffusivities for both chlorferon and DETP, but linear relations between effective diffusivity and cell weight fraction were derived from experimental data. Calcium-alginate gel beads with radii of 1.65-1.70 mm used in this study were not subject to diffusional limitations: external mass transfer resistances were negligible based on Biot number calculations and effectiveness factors indicated that internal mass transfer resistance was negligible. Therefore, the degradation rates of chlorferon and DETP inside Ca-alginate gel beads were reaction-limited. (c) 2007 Wiley Periodicals, Inc.

  13. In vitro drug response and efflux transporters associated with drug resistance in pediatric high grade glioma and diffuse intrinsic pontine glioma.

    Directory of Open Access Journals (Sweden)

    Susanna J E Veringa

    Full Text Available Pediatric high-grade gliomas (pHGG, including diffuse intrinsic pontine gliomas (DIPG, are the leading cause of cancer-related death in children. While it is clear that surgery (if possible, and radiotherapy are beneficial for treatment, the role of chemotherapy for these tumors is still unclear. Therefore, we performed an in vitro drug screen on primary glioma cells, including three DIPG cultures, to determine drug sensitivity of these tumours, without the possible confounding effect of insufficient drug delivery. This screen revealed a high in vitro cytotoxicity for melphalan, doxorubicine, mitoxantrone, and BCNU, and for the novel, targeted agents vandetanib and bortezomib in pHGG and DIPG cells. We subsequently determined the expression of the drug efflux transporters P-gp, BCRP1, and MRP1 in glioma cultures and their corresponding tumor tissues. Results indicate the presence of P-gp, MRP1 and BCRP1 in the tumor vasculature, and expression of MRP1 in the glioma cells themselves. Our results show that pediatric glioma and DIPG tumors per se are not resistant to chemotherapy. Treatment failure observed in clinical trials, may rather be contributed to the presence of drug efflux transporters that constitute a first line of drug resistance located at the blood-brain barrier or other resistance mechanism. As such, we suggest that alternative ways of drug delivery may offer new possibilities for the treatment of pediatric high-grade glioma patients, and DIPG in particular.

  14. Control of the resistive wall mode with internal coils in the DIII-D tokamak

    International Nuclear Information System (INIS)

    Okabayashi, M.; Bialek, J.; Bondeson, A.; Chance, M.S.; Chu, M.S.; Garofalo, A.M.; Hatcher, R.; In, Y.; Jackson, G.L.; Jayakumar, R.J.; Jensen, T.H.; Katsuro-Hopkins, O.; Haye, R.J. La; Liu, Y.Q.; Navratil, G.A.; Reimerdes, H.; Scoville, J.T.; Strait, E.J.; Takechi, M.; Turnbull, A.D.; Gohil, P.; Kim, J.S.; Makowski, M.A.; Manickam, J.; Menard, J.

    2005-01-01

    Internal coils, 'I-Coils', were installed inside the vacuum vessel of the DIII-D device to generate non-axisymmetric magnetic fields to act directly on the plasma. These fields are predicted to stabilize the resistive wall mode (RWM) branch of the long-wavelength external kink mode with plasma beta close to the ideal wall limit. Feedback using these I-Coils was found to be more effective as compared to using external coils located outside the vacuum vessel. Locating the coils inside the vessel allows for a faster response and the coil geometry also allows for better coupling to the helical mode structure. Initial results were reported previously (Strait E.J. et al 2004 Phys. Plasmas 11 2505). This paper reports on results from extended feedback stabilization operations, achieving plasma parameters up to the regime of C β ∼ 1.0 and open loop growth rates of γ open τ w ∼ 25 where the RWM was predicted to be unstable with only the 'rotational viscous stabilization mechanism'. Here C β ∼ (β - β no-wall.limit )/(β ideal.wall.limit - β no-wall.limit ) is a measure of the beta relative to the stability limits without a wall and with a perfectly conducting wall, and τ w is the resistive flux penetration time of the wall. These feedback experimental results clarified the processes of dynamic error field correction and direct RWM stabilization, both of which took place simultaneously during RWM feedback stabilization operation. MARS-F modelling provides a critical rotation velocity in reasonable agreement with the experiment and predicts that the growth rate increases rapidly as rotation decreases below the critical. The MARS-F code also predicted that for successful RWM magnetic feedback, the characteristic time of the power supply should be limited to a fraction of the growth time of the targeted RWM. The possibility of further improvements in the presently achievable range of operation of feedback gain values is also discussed

  15. A Broad G Protein-Coupled Receptor Internalization Assay that Combines SNAP-Tag Labeling, Diffusion-Enhanced Resonance Energy Transfer, and a Highly Emissive Terbium Cryptate.

    Science.gov (United States)

    Levoye, Angélique; Zwier, Jurriaan M; Jaracz-Ros, Agnieszka; Klipfel, Laurence; Cottet, Martin; Maurel, Damien; Bdioui, Sara; Balabanian, Karl; Prézeau, Laurent; Trinquet, Eric; Durroux, Thierry; Bachelerie, Françoise

    2015-01-01

    Although G protein-coupled receptor (GPCR) internalization has long been considered as a major aspect of the desensitization process that tunes ligand responsiveness, internalization is also involved in receptor resensitization and signaling, as well as the ligand scavenging function of some atypical receptors. Internalization thus contributes to the diversity of GPCR-dependent signaling, and its dynamics and quantification in living cells has generated considerable interest. We developed a robust and sensitive assay to follow and quantify ligand-induced and constitutive-induced GPCR internalization but also receptor recycling in living cells. This assay is based on diffusion-enhanced resonance energy transfer (DERET) between cell surface GPCRs labeled with a luminescent terbium cryptate donor and a fluorescein acceptor present in the culture medium. GPCR internalization results in a quantifiable reduction of energy transfer. This method yields a high signal-to-noise ratio due to time-resolved measurements. For various GPCRs belonging to different classes, we demonstrated that constitutive and ligand-induced internalization could be monitored as a function of time and ligand concentration, thus allowing accurate quantitative determination of kinetics of receptor internalization but also half-maximal effective or inhibitory concentrations of compounds. In addition to its selectivity and sensitivity, we provided evidence that DERET-based internalization assay is particularly suitable for characterizing biased ligands. Furthermore, the determination of a Z'-factor value of 0.45 indicates the quality and suitability of DERET-based internalization assay for high-throughput screening (HTS) of compounds that may modulate GPCRs internalization.

  16. A broad G protein-coupled receptor internalization assay that combines SNAP-tag labeling, diffusion-enhanced resonance energy transfer, and a highly emissive terbium cryptate acceptor

    Directory of Open Access Journals (Sweden)

    Angélique eLEVOYE

    2015-11-01

    Full Text Available Although G protein-coupled receptor (GPCR internalization has long been considered a major aspect of the desensitization process that tunes ligand responsiveness, internalization is also involved in receptor resensitization and signaling, as well as the ligand scavenging function of some atypical receptors. Internalization thus contributes to the diversity of GPCR-dependent signaling, and its dynamics and quantification in living cells has generated considerable interest. We developed a robust and sensitive assay to follow and quantify ligand-induced and constitutive GPCR internalization but also receptor recycling in living cells. This assay is based on diffusion-enhanced resonance energy transfer (DERET between cell surface GPCRs labeled with a luminescent terbium cryptate donor and a fluorescein acceptor present in the culture medium. GPCR internalization results in a quantifiable reduction of energy transfer. This method yields a high signal-to-noise ratio due to time-resolved measurements. For various GPCRs belonging to different classes, we demonstrated that constitutive and ligand-induced internalization could be monitored as a function of time and ligand concentration, thus allowing accurate quantitative determination of kinetics of receptor internalization but also half-maximal effective or inhibitory concentrations of compounds. In addition to its selectivity and sensitivity, we provided evidence that DERET-based internalization assay is particularly suitable for characterizing biased ligands. Furthermore, the determination of a Z’-factor value of 0.45 indicates the quality and suitability of DERET-based internalization assay for high-throughput screening (HTS of compounds that may modulate GPCRs internalization.

  17. New definitions of focal and diffuse anaplasia in Wilms tumor: the International Society of Paediatric Oncology (SIOP) experience

    NARCIS (Netherlands)

    Vujanić, G. M.; Harms, D.; Sandstedt, B.; Weirich, A.; de Kraker, J.; Delemarre, J. F.

    1999-01-01

    Unlike the original definitions of focal (FA) and diffuse anaplasia (DA) in Wilms tumor (WT), recently redefined FA and DA proved to be of prognostic significance. The aim of the study was to analyze WT from the SIOP file, the majority of which were treated with preoperative chemotherapy, in order

  18. Internal (m=1, n=1) and (m=2, n=1) resistive modes in the toroidal Tokomak with circular cross sections

    International Nuclear Information System (INIS)

    Bussac, M.N.; Pellat, R.; Edery, D.; Soule, J.L.

    1976-01-01

    A linear analysis is presented of the toroidal coupling between the internal resistive modes (m=1, n=1) and (m=2, n=1) in the Tokomak with circular cross sections. One includes the resistive and diamagnetic effects in the singular layers where the safety factor q takes respectively the values one and two. By expanding the MHD equations in powers of epsilon, the local inverse of the aspect ratio, one obtains a system of two coupled equations for the harmonic amplitudes. When the shear is finite on q=1, the toroidal coupling is negligible. In the opposite limit, one can explain: the experimental behaviour of the (m=1, n=1) mode before the internal disruption; the simultaneous observation of the modes (m=1, n=1) and [de

  19. Brain microstructural abnormalities revealed by diffusion tensor images in patients with treatment-resistant depression compared with major depressive disorder before treatment

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Yan, E-mail: clare1475@hotmail.com [Department of Radiology, Ren-Ji Hospital, Jiao Tong University Medical School, Shanghai 200127 (China); Qin Lingdi, E-mail: flyfool318@hotmail.com [Department of Radiology, Ren-Ji Hospital, Jiao Tong University Medical School, Shanghai 200127 (China); Chen Jun, E-mail: doctor_cj@msn.com [Shanghai Mental Health Center, Jiao Tong University Medical School, Shanghai, 200030 (China); Qian Lijun, E-mail: dearqlj@hotmail.com [Department of Radiology, Ren-Ji Hospital, Jiao Tong University Medical School, Shanghai 200127 (China); Tao Jing, E-mail: jing318@hotmail.com [Department of Radiology, Ren-Ji Hospital, Jiao Tong University Medical School, Shanghai 200127 (China); Fang Yiru, E-mail: fangyr@sina.com [Shanghai Mental Health Center, Jiao Tong University Medical School, Shanghai, 200030 (China); Xu Jianrong, E-mail: xujianr@hotmail.com [Department of Radiology, Ren-Ji Hospital, Jiao Tong University Medical School, Shanghai 200127 (China)

    2011-11-15

    Treatment-resistant depression (TRD) is a therapeutic challenge for clinicians. Despite a growing interest in this area, an understanding of the pathophysiology of depression, particularly TRD, remains lacking. This study aims to detect the white matter abnormalities of whole brain fractional anisotropy (FA) in patients with TRD compared with major depressive disorder (MDD) before treatment by voxel-based analysis using diffusion tensor imaging. A total of 100 patients first diagnosed with untreated MDD underwent diffusion tensor imaging scans. 8 weeks after the first treatment, 54 patients showed response to the medication, whereas 46 did not. Finally, 20 patients were diagnosed with TRD after undergoing another treatment. A total of 20 patients with TRD and another 20 with MDD before treatment matched in gender, age, and education was enrolled in the research. For every subject, an FA map was generated and analyzed using SPM5. Subsequently, t-test was conducted to compare the FA values voxel to voxel between the two groups (p < 0.001 [FDR corrected], t > 7.57, voxel size > 30). Voxel-based morphometric (VBM) analysis was performed using T1W images. Significant reductions in FA were found in the white matter located in the bilateral of the hippocampus (left hippocampus: t = 7.63, voxel size = 50; right hippocampus: t = 7.82, voxel size = 48). VBM analysis revealed no morphological abnormalities between the two groups. Investigation of brain anisotropy revealed significantly decreased FA in both sides of the hippocampus. Although preliminary, our findings suggest that microstructural abnormalities in the hippocampus indicate vulnerability to treatment resistance.

  20. Brain microstructural abnormalities revealed by diffusion tensor images in patients with treatment-resistant depression compared with major depressive disorder before treatment

    International Nuclear Information System (INIS)

    Zhou Yan; Qin Lingdi; Chen Jun; Qian Lijun; Tao Jing; Fang Yiru; Xu Jianrong

    2011-01-01

    Treatment-resistant depression (TRD) is a therapeutic challenge for clinicians. Despite a growing interest in this area, an understanding of the pathophysiology of depression, particularly TRD, remains lacking. This study aims to detect the white matter abnormalities of whole brain fractional anisotropy (FA) in patients with TRD compared with major depressive disorder (MDD) before treatment by voxel-based analysis using diffusion tensor imaging. A total of 100 patients first diagnosed with untreated MDD underwent diffusion tensor imaging scans. 8 weeks after the first treatment, 54 patients showed response to the medication, whereas 46 did not. Finally, 20 patients were diagnosed with TRD after undergoing another treatment. A total of 20 patients with TRD and another 20 with MDD before treatment matched in gender, age, and education was enrolled in the research. For every subject, an FA map was generated and analyzed using SPM5. Subsequently, t-test was conducted to compare the FA values voxel to voxel between the two groups (p 7.57, voxel size > 30). Voxel-based morphometric (VBM) analysis was performed using T1W images. Significant reductions in FA were found in the white matter located in the bilateral of the hippocampus (left hippocampus: t = 7.63, voxel size = 50; right hippocampus: t = 7.82, voxel size = 48). VBM analysis revealed no morphological abnormalities between the two groups. Investigation of brain anisotropy revealed significantly decreased FA in both sides of the hippocampus. Although preliminary, our findings suggest that microstructural abnormalities in the hippocampus indicate vulnerability to treatment resistance.

  1. Internal resistor of multi-functional tunnel barrier for selectivity and switching uniformity in resistive random access memory.

    Science.gov (United States)

    Lee, Sangheon; Woo, Jiyong; Lee, Daeseok; Cha, Euijun; Hwang, Hyunsang

    2014-01-01

    In this research, we analyzed the multi-functional role of a tunnel barrier that can be integrated in devices. This tunnel barrier, acting as an internal resistor, changes its resistance with applied bias. Therefore, the current flow in the devices can be controlled by a tunneling mechanism that modifies the tunnel barrier thickness for non-linearity and switching uniformity of devices. When a device is in a low-resistance state, the tunnel barrier controls the current behavior of the device because most of the bias is applied to the tunnel barrier owing to its higher resistance. Furthermore, the tunnel barrier induces uniform filament formation during set operation with the tunnel barrier controlling the current flow.

  2. Enhancement Corrosion Resistance of (γ-Glycidyloxypropyl-Silsesquioxane-Titanium Dioxide Films and Its Validation by Gas Molecule Diffusion Coefficients Using Molecular Dynamics (MD Simulation

    Directory of Open Access Journals (Sweden)

    Haiyan Wang

    2014-01-01

    Full Text Available Based on silsesquioxanes (SSO derived from the hydrolytic condensation of (γ-glycidyloxypropyltrimethoxysilane (GPMS and titanium tetrabutoxide (TTB, hybrid films on aluminum alloy (AA, film-GPMS-SSO (f-GS and f-GS-TTBi% (f-GSTT5%–25%, i = 5, 10, 15, 20 and 25 wt%, were prepared and tested by electrochemical measurements with typical potentiodynamic polarization curves. The Icorr values of the samples were significantly lower, comparing with the Icorr values of the f-GS, AA and f-GS modified tetraethoxysilane (TEOS in the previous study, which implies that the TTB5%–25% (TiO2 additions in the coatings indeed enhance the electrochemical corrosion resistance. Correlations between the film structures and anticorrosion properties were discussed. To validate the corresponding anticorrosion experiment results, different 3D-amorphous cubic unit cells were employed as models to investigate the self-diffusion coefficient (SDC for SO2, NO2 and H2O molecules by molecular dynamics (MD simulation. All of the SDCs calculated for SO2, NO2 and H2O diffusing in f-GSTT5%–25% cells were less than the SDCs in f-GS. These results validated the corresponding anticorrosion experiment results.

  3. The Limits of International Adjudication: Authority and Resistance of Regional Economic Courts in Times of Crisis

    DEFF Research Database (Denmark)

    Caserta, Salvatore; Cebulak, Pola

    2018-01-01

    Integration System have all faced varied forms of resistance to their involvement and their general authority. By comparing these four case studies from across the globe, the article identifies institutional and contextual factors that explain the uneven resistance. While the regional economic courts...

  4. International Spread of an Epidemic Population of Salmonella enterica Serotype Kentucky ST198 Resistant to Ciprofloxacin

    DEFF Research Database (Denmark)

    Le Hello, Simon; Hendriksen, Rene S.; Doublet, Benoit

    2011-01-01

    National Salmonella surveillance systems from France, England and Wales, Denmark, and the United States identified the recent emergence of multidrug-resistant isolates of Salmonella enterica serotype Kentucky displaying high-level resistance to ciprofloxacin. A total of 489 human cases were ident...

  5. Thermal resistance of rotating closed-loop pulsating heat pipes: Effects of working fluids and internal diameters

    Directory of Open Access Journals (Sweden)

    Kammuang-Lue Niti

    2017-01-01

    Full Text Available The objective of this study was to experimentally investigate the effects of working fluids and internal diameters on the thermal resistance of rotating closed-loop pul¬sating heat pipes (RCLPHP. The RCLPHP were made of a copper tube with internal diameters of 1.50 mm and 1.78 mm, bent into the shape of a flower petal, and arranged into a circle with 11 turns. The evaporator section was located at the outer end of the tube bundle. R123, ethanol, and water were filled as the working fluids. The RCLPHP was rotated at centrifugal accelerations 0.5, 1, 3, 5, 10, and 20 times of the gravitational acceleration considered at the connection between the evaporator and the condenser sections. The heat input was varied from 30 W to 50 W, and then to 100 W, 150 W, and 200 W. It can be concluded that when the latent heat of evaporation increases, the pressure difference between the evaporator and the condenser sections decreases, and the thermal resistance increases. Moreover, when the internal diameter increases, the driving force increases and the frictional force proportionally decreases, or the Karman number increases, and the thermal resistance decreases.

  6. Ultra-low specific on-resistance high-voltage vertical double diffusion metal–oxide–semiconductor field-effect transistor with continuous electron accumulation layer

    International Nuclear Information System (INIS)

    Ma Da; Luo Xiao-Rong; Wei Jie; Tan Qiao; Zhou Kun; Wu Jun-Feng

    2016-01-01

    A new ultra-low specific on-resistance (R on,sp ) vertical double diffusion metal–oxide–semiconductor field-effect transistor (VDMOS) with continuous electron accumulation (CEA) layer, denoted as CEA-VDMOS, is proposed and its new current transport mechanism is investigated. It features a trench gate directly extended to the drain, which includes two PN junctions. In on-state, the electron accumulation layers are formed along the sides of the extended gate and introduce two continuous low-resistance current paths from the source to the drain in a cell pitch. This mechanism not only dramatically reduces the R on,sp but also makes the R on,sp almost independent of the n-pillar doping concentration (N n ). In off-state, the depletion between the n-pillar and p-pillar within the extended trench gate increases the N n , and further reduces the R on,sp . Especially, the two PN junctions within the trench gate support a high gate–drain voltage in the off-state and on-state, respectively. However, the extended gate increases the gate capacitance and thus weakens the dynamic performance to some extent. Therefore, the CEA-VDMOS is more suitable for low and medium frequencies application. Simulation indicates that the CEA-VDMOS reduces the R on,sp by 80% compared with the conventional super-junction VDMOS (CSJ-VDMOS) at the same high breakdown voltage (BV). (paper)

  7. Diffusion of knowledge and urban legends: the case of internments due to sanitation conditions - DOI: 10.3395/reciis.v2i2.152en

    Directory of Open Access Journals (Sweden)

    Christovam Barcellos

    2009-03-01

    Full Text Available The statement that in Brazil “68% of the internments are due to the lack of sanitation” is diffused on the Web pages. The weight of the diseases related with water in the internment is clearly overestimated. If one considers just the hydric transmission diseases, this proportion falls to 4.8%. 204 websites of environment defense organizations and institutions, professional associations, universities and research centers quoting this statement were found upon a search on the Internet. The transmission standards of false information characterize this as one additional urban legend among those that impair the establishment of priorities. As the public policies are established from an accumulation of knowledge, the transmission of information in reports, scientific papers and texts on the Internet may represent the longing of pressure groups to alter priorities of the sanitation area.

  8. International collaboration for development of accident-resistant LWR fuel. International Collaboration for Development of Accident Resistant Light Water Reactor Fuel

    International Nuclear Information System (INIS)

    Sowder, Andrew

    2013-01-01

    Following the March 2011 multi-unit accident at the Fukushima Daiichi plant, there has been increased interest in the development of breakthrough nuclear fuel designs that can reduce or eliminate many of the outcomes of a severe accident at a light water reactor (LWR) due to loss of core cooling following an extended station blackout or other initiating event. With this interest and attention comes a unique opportunity for the nuclear industry to fundamentally change the nature and impact of severe accidents. Clearly, this is no small feat. The challenges are many and the technical barriers are high. Early estimates for moving maturing R and D concepts to the threshold of commercialisation exceed one billion USD. Given the anticipated effort and resources required, no single entity or group can succeed alone. Accordingly, the Electric Power Research Institute (EPRI) sees the need for and promise of cooperation among many stakeholders on an international scale to bring about what could be transformation in LWR fuel performance and robustness. An important initial task in any R and D programme is to define the goals and metrics for measuring success. As starting points for accident-tolerant fuel development, the extension of core coolability under loss of coolant conditions and the elimination or reduction of hydrogen generation are widely recognised R and D endpoints for deployment. Furthermore, any new LWR fuel technology will, at a minimum, need to (1) be compatible with the safe, economic operation of existing plants and (2) maintain acceptable or improve nuclear fuel performance under normal operating conditions. While the primary focus of R and D to date has been on cladding and fuel improvements, there are a number of other potential paths to improve outcomes following a severe accident at an LWR that include modifications to other fuel hardware and core internals to fully address core coolability, criticality, and hydrogen generation concerns. The US

  9. Ten key points for the appropriate use of antibiotics in hospitalised patients: a consensus from the Antimicrobial Stewardship and Resistance Working Groups of the International Society of Chemotherapy

    NARCIS (Netherlands)

    Hara, G. Levy; Kanj, S.S.; Pagani, L.; Abbo, L.; Endimiani, A.; Wertheim, H.F.L.; Amabile-Cuevas, C.; Tattevin, P.; Mehtar, S.; Cardoso, F.; Unal, S.; Gould, I.

    2016-01-01

    The Antibiotic Stewardship and Resistance Working Groups of the International Society for Chemotherapy propose ten key points for the appropriate use of antibiotics in hospital settings. (i) Get appropriate microbiological samples before antibiotic administration and carefully interpret the results:

  10. International spread of multidrug-resistant Salmonella Schwarzengrund in food products

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Hendriksen, Rene S.; Lockett, Jana

    2007-01-01

    We compared 581 Salmonella enterica serotype Schwarzengrund isolates from persons, food, and food animals in Denmark, Thailand, and the United States by antimicrobial drug susceptibility and pulsed-field gel electrophoresis (PFGE) typing. Resistance, including resistance to nalidixic acid......, was frequent among isolates from persons and chickens in Thailand, persons in the United States, and food imported from Thailand to Denmark and the United States. A total of 183 PFGE patterns were observed, and 136 (23.4%) isolates had the 3 most common patterns. Seven of 14 isolates from persons in Denmark...... had patterns found in persons and chicken meat in Thailand; 22 of 390 human isolates from the United States had patterns found in Denmark and Thailand. This study suggests spread of multidrug-resistant S. Schwarzengrund from chickens to persons in Thailand, and from imported Thai food products...

  11. Internal filament modulation in low-dielectric gap design for built-in selector-less resistive switching memory application

    Science.gov (United States)

    Chen, Ying-Chen; Lin, Chih-Yang; Huang, Hui-Chun; Kim, Sungjun; Fowler, Burt; Chang, Yao-Feng; Wu, Xiaohan; Xu, Gaobo; Chang, Ting-Chang; Lee, Jack C.

    2018-02-01

    Sneak path current is a severe hindrance for the application of high-density resistive random-access memory (RRAM) array designs. In this work, we demonstrate nonlinear (NL) resistive switching characteristics of a HfO x /SiO x -based stacking structure as a realization for selector-less RRAM devices. The NL characteristic was obtained and designed by optimizing the internal filament location with a low effective dielectric constant in the HfO x /SiO x structure. The stacking HfO x /SiO x -based RRAM device as the one-resistor-only memory cell is applicable without needing an additional selector device to solve the sneak path issue with a switching voltage of ~1 V, which is desirable for low-power operating in built-in nonlinearity crossbar array configurations.

  12. International cooperation in the field of studying seismic resistance of NPP components

    International Nuclear Information System (INIS)

    Kaznovskij, S.P.; Chechenov, Kh.D.

    1989-01-01

    Main results of the conference of representations from the USSR, Bulgarie, Hungary and Chechoslovakia related to the problems of seismology and seismic resistance of NPPs are briefly formulated. One of the important results of the conference consists in the agrement concerning cooperation and mutual application of seismoexplosive testing ground near Nalchik

  13. Enhanced Oxygen Diffusion Within the Internal Oxidation Zone of Alloy 617 in Controlled Impurity Helium Environments from 1023 K to 1123 K (750 °C to 850 °C)

    Science.gov (United States)

    Gulsoy, Gokce; Was, Gary S.

    2015-04-01

    Alloy 617 was exposed to He-CO-CO2 environments with of either 9 or 1320 at temperatures from 1023 K to 1123 K (750 °C to 850 °C) to determine the oxygen diffusion coefficients within the internal oxidation zone of the alloy. The oxygen diffusion coefficients determined based on both intergranular and transgranular oxidation rates were several orders of magnitude greater than those reported in pure nickel and in nickel-based binary alloys, indicating that the rapid internal aluminum oxidation of Alloy 617 was primarily due to enhanced oxygen diffusion along the incoherent Al2O3-alloy interfaces. The range of activation energy values determined for oxygen diffusion associated with the intergranular aluminum oxidation was from 149.6 to 154.7 kJ/mol, and that associated with the transgranular aluminum oxidation was from 244.7 to 283.5 kJ/mol.

  14. Influences of MCrAlY coatings on oxidation resistance of single crystal superalloy DD98M and their inter-diffusion behaviors

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Long [School of Materials and Metallurgy, Northeastern University, Shenyang 110819 (China); Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Xin, Li, E-mail: xli@imr.ac.cn [Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, Xinyue; Wang, Xiaolan; Wei, Hua; Zhu, Shenglong; Wang, Fuhui [Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2015-11-15

    Oxidation and interdiffusion behaviors of Ni-based single crystal superalloy DD98M with nominal compositions Ni–5.0Co–6.0Cr–6.3Al–6.0W–2.0Mo–6.0Ta–1.0Ti (in wt.%) and two types of MCrAlY coatings at 1000 °C and 1050 °C were investigated. Complex oxides formed on the surface of DD98M alloy when oxidized at 1000 °C and 1050 °C, which stratified, cracked and spalled. The faceted-like AlN and the particle-like and strip-like TiN formed in the alloy. The application of the NiCrAlY and NiCoCrAlYHfSi coatings greatly improved the oxidation resistance of DD98M alloy. After 500 h oxidation, α-Al{sub 2}O{sub 3} was still the dominate phase in the oxide scales formed on the coated specimens. The adhesion of the oxide scale on the NiCoCrAlYHfSi coating was much better than that on the NiCrAlY coating. Interdiffusion occurred between the coatings and the substrate, which led to the formation of the IDZ and SRZ. The IDZ of the NiCrAlY coated specimen was composed of γ phase and Al- and Ta-rich γ′ phase. The γ′ phase in the IDZ accommodated most of the inward diffusing aluminum, so the SRZ formation was suppressed when oxidized at 1050 °C. However the formation of SRZ with μ-TCP still occurred when oxidized at 1000 °C probably due to the low solubility and slow diffusion rate of the alloying elements at lower temperature. The IDZ of the NiCoCrAlYHfSi coated specimen was a single γ phase. A large amount of μ-TCP precipitated in the SRZ of the NiCoCrAlYHfSi coated specimen when oxidized at 1000 °C and 1050 °C. It can be concluded coating composition has a significant effect on the development of the IDZ and SRZ. Thermal exposure temperature also has influences on the formation of the SRZ. The mechanism of SRZ formation and TCP precipitation are discussed. - Graphical abstract: The TEM micrograph of the IDZ and SRZ of the NiCoCrAlYHfSi-coated specimen oxidized at 1050 °C for 100 h and the respective diffraction patterns of the needle-like and the

  15. Diffusion-weighted magnetic resonance imaging predicts survival in patients with liver-predominant metastatic colorectal cancer shortly after selective internal radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Schmeel, Frederic Carsten; Simon, Birgit; Luetkens, Julian Alexander; Traeber, Frank; Schmeel, Leonard Christopher; Schild, Hans Heinz; Hadizadeh, Dariusch Reza [University Hospital Bonn, Rheinische-Friedrich-Wilhelms-Universitaet Bonn, Department of Radiology, Bonn (Germany); Sabet, Amir [University Hospital Bonn, Rheinische-Friedrich-Wilhelms-Universitaet Bonn, Department of Nuclear Medicine, Bonn (Germany); University Hospital Essen, Universitaet Duisburg-Essen, Department of Nuclear Medicine, Essen (Germany); Ezziddin, Samer [University Hospital Bonn, Rheinische-Friedrich-Wilhelms-Universitaet Bonn, Department of Nuclear Medicine, Bonn (Germany); University Hospital Saarland, Universitaet des Saarlandes, Department of Nuclear Medicine, Homburg (Germany)

    2017-03-15

    To investigate whether quantifications of apparent diffusion coefficient (ADC) on diffusion-weighted imaging (DWI) can predict overall survival (OS) in patients with liver-predominant metastatic colorectal cancer (CRC) following selective internal radiation therapy with {sup 90}Yttrium-microspheres (SIRT). Forty-four patients underwent DWI 19 ± 16 days before and 36 ± 10 days after SIRT. Tumour-size and intratumoral minimal ADC (minADC) values were measured for 132 liver metastases on baseline and follow-up DWI. Optimal functional imaging response to treatment was determined by receiver operating characteristics and defined as ≥22 % increase in post-therapeutic minADC. Survival analysis was performed with the Kaplan-Meier method and Cox-regression comparing various variables with potential impact on OS. Median OS was 8 months. The following parameters were significantly associated with median OS: optimal functional imaging response (18 vs. 5 months; p < 0.001), hepatic tumour burden <50 % (8 vs. 5 months; p = 0.018), Eastern Cooperative Oncology Group performance scale <1 (10 vs. 4 months; p = 0.012) and progressive disease according to Response and Evaluation Criteria in Solid Tumours (8 vs. 3 months; p = 0.001). On multivariate analysis, optimal functional imaging response and hepatic tumour burden remained independent predictors of OS. Functional imaging response assessment using minADC changes on DWI may predict survival in CRC shortly after SIRT. (orig.)

  16. Transport Properties of Bulk Thermoelectrics—An International Round-Robin Study, Part I: Seebeck Coefficient and Electrical Resistivity

    Science.gov (United States)

    Wang, Hsin; Porter, Wallace D.; Böttner, Harald; König, Jan; Chen, Lidong; Bai, Shengqiang; Tritt, Terry M.; Mayolet, Alex; Senawiratne, Jayantha; Smith, Charlene; Harris, Fred; Gilbert, Patricia; Sharp, Jeff W.; Lo, Jason; Kleinke, Holger; Kiss, Laszlo

    2013-04-01

    Recent research and development of high-temperature thermoelectric materials has demonstrated great potential for converting automobile exhaust heat directly into electricity. Thermoelectrics based on classic bismuth telluride have also started to impact the automotive industry by enhancing air-conditioning efficiency and integrated cabin climate control. In addition to engineering challenges of making reliable and efficient devices to withstand thermal and mechanical cycling, the remaining issues in thermoelectric power generation and refrigeration are mostly materials related. The dimensionless figure of merit, ZT, still needs to be improved from the current value of 1.0 to 1.5 to above 2.0 to be competitive with other alternative technologies. In the meantime, the thermoelectric community could greatly benefit from the development of international test standards, improved test methods, and better characterization tools. Internationally, thermoelectrics have been recognized by many countries as a key component for improving energy efficiency. The International Energy Agency (IEA) group under the Implementing Agreement for Advanced Materials for Transportation (AMT) identified thermoelectric materials as an important area in 2009. This paper is part I of the international round-robin testing of transport properties of bulk thermoelectrics. The main foci in part I are the measurement of two electronic transport properties: Seebeck coefficient and electrical resistivity.

  17. Three-dimensional internal structure of an entire alpine rockglacier, detected by Electrical Resistivity Imaging

    Science.gov (United States)

    Emmert, Adrian; Kneisel, Christof

    2017-04-01

    Uertsch rockglacier (46.61° N, 9.84°E, ca. 2500m asl.) is a tongue-shaped 300m x 100m landform at the head of a small high mountain valley in the Eastern Swiss Alps. Located at the lower end of possible permafrost existence, the rockglacier shows indications of permafrost decay although borehole temperature measurements exhibit an at least partly occurrence of permanently frozen subsurface conditions. To delimit the extent of the frozen area and to characterize subsurface structures, we performed three adjacent 3-D Electrical Resistivity Imaging (ERI) surveys consisting of data from altogether 138 merged 2-D profiles, covering nearly the entire rockglacier by an investigation area of more than 2.5 ha. More than 47000 data points of Wenner-Schlumberger and Dipol-Dipol electrode arrays grant sufficient data coverage. Ground-truthing was achieved through borehole temperature measurements and multiple comparative ground-penetrating radar (GPR) and seismic refraction tomography (SRT) surveys. Results show that the rockglacier today lacks a consistent permafrost table and only shows a patchy permafrost distribution. Several structures differing in geometry and electric resistivity show a complex pattern of ice-rich, ice-poor and ice-free areas. We could identify glacial influence in the root zone of the rockglacier, where a 3200m2 perennial surface ice field is visible. In a downslope direction, a shallow layer of high resistivity values, which is limited to the shallow subsurface, follows the ice field and indicates a genesis by refreezing meltwater. The central part of the rockglacier also shows traces of glacial interaction by the occurrence of a several meters thick buried ice patch in the shallow subsurface at a marginal position. Next to this position, in an area where longitudinal surface ridges are exposed, modelled resistivity values indicate frozen conditions with relatively low ice content, limited to the shallow subsurface. We assume that these structures

  18. Thermal conductivity of a graphite bipolar plate (BPP) and its thermal contact resistance with fuel cell gas diffusion layers: Effect of compression, PTFE, micro porous layer (MPL), BPP out-of-flatness and cyclic load

    Science.gov (United States)

    Sadeghifar, Hamidreza; Djilali, Ned; Bahrami, Majid

    2015-01-01

    This paper reports on measurements of thermal conductivity of a graphite bipolar plate (BPP) as a function of temperature and its thermal contact resistance (TCR) with treated and untreated gas diffusion layers (GDLs). The thermal conductivity of the BPP decreases with temperature and its thermal contact resistance with GDLs, which has been overlooked in the literature, is found to be dominant over a relatively wide range of compression. The effects of PTFE loading, micro porous layer (MPL), compression, and BPP out-of-flatness are also investigated experimentally. It is found that high PTFE loadings, MPL and even small BPP out-of-flatness increase the BPP-GDL thermal contact resistance dramatically. The paper also presents the effect of cyclic load on the total resistance of a GDL-BPP assembly, which sheds light on the behavior of these materials under operating conditions in polymer electrolyte membrane fuel cells.

  19. New definitions of focal and diffuse anaplasia in Wilms tumor: the International Society of Paediatric Oncology (SIOP) experience.

    Science.gov (United States)

    Vujanić, G M; Harms, D; Sandstedt, B; Weirich, A; de Kraker, J; Delemarre, J F

    1999-05-01

    Unlike the original definitions of focal (FA) and diffuse anaplasia (DA) in Wilms tumor (WT), recently redefined FA and DA proved to be of prognostic significance. The aim of the study was to analyze WT from the SIOP file, the majority of which were treated with preoperative chemotherapy, in order to investigate whether chemotherapy influenced the presence of anaplasia, whether the new definitions were applicable to these tumors, and whether they were of prognostic significance. The unilateral anaplastic WT of children up to 16 years of age from the SIOP 6 and 9 nephroblastoma trials and studies were first classified according to the original definitions and analyzed. Then they were reclassified and analyzed according to the new definitions. Anaplasia was diagnosed in 86 (5.5%) of 1,554 unilateral WT. The age at diagnosis ranged from 9 to 175 months (median, 63) and more than half of children were over 5 years of age. From 15% to 85% of the tumor mass showed chemotherapy-induced changes. Blastemal anaplasia was seen in 74, stromal in 23, and epithelial in 22 cases. According to the original definitions, FA was diagnosed in 55 (64%) and DA in 31 (36%) cases. In total, 48% children were alive and well, including 53% with FA and 39% with DA (P = 0.23). When reclassified, 39 old FA cases were moved to the new DA group, resulting in 70 (81%) DA and 16 (19%) FA cases. The female-to-male ratio for FA changed from 1.9:1 to 1:1 while remained unchanged for DA. The percentage of FA stage I cases increased from 31% to 44%, while it decreased from 25% to 6% for stage III. For other stages it remained virtually unchanged. The overall 4-year actual survival was 75% for FA and 41% for DA (P = 0.03). Preoperative chemotherapy did not obliterate or produce anaplasia. The new definitions were applicable to pretreated cases and they were of prognostic significance.

  20. Effect of Internal Heat Source on the Onset of Double-Diffusive Convection in a Rotating Nanofluid Layer with Feedback Control Strategy

    Directory of Open Access Journals (Sweden)

    I. K. Khalid

    2017-01-01

    Full Text Available A linear stability analysis has been carried out to examine the effect of internal heat source on the onset of Rayleigh–Bénard convection in a rotating nanofluid layer with double diffusive coefficients, namely, Soret and Dufour, in the presence of feedback control. The system is heated from below and the model used for the nanofluid layer incorporates the effects of thermophoresis and Brownian motion. Three types of bounding systems of the model have been considered which are as follows: both the lower and upper bounding surfaces are free, the lower is rigid and the upper is free, and both of them are rigid. The eigenvalue equations of the perturbed state were obtained from a normal mode analysis and solved using the Galerkin method. It is found that the effect of internal heat source and Soret parameter destabilizes the nanofluid layer system while increasing the Coriolis force, feedback control, and Dufour parameter helps to postpone the onset of convection. Elevating the modified density ratio hastens the instability in the system and there is no significant effect of modified particle density in a nanofluid system.

  1. Developing an approach to assessing the political feasibility of global collective action and an international agreement on antimicrobial resistance.

    Science.gov (United States)

    Rogers Van Katwyk, Susan; Danik, Marie Évelyne; Pantis, Ioana; Smith, Rachel; Røttingen, John-Arne; Hoffman, Steven J

    2016-01-01

    Antimicrobial resistance (AMR) is a global issue. International trade, travel, agricultural practices, and environmental contamination all make it possible for resistant microbes to cross national borders. Global collective action is needed in the form of an international agreement or other mechanism that brings states together at the negotiation table and commits them to adopt or implement policies to limit the spread of resistant microorganisms. This article describes an approach to assessing whether political and stakeholder interests can align to commit to tackling AMR. Two dimensions affecting political feasibility were selected and compared across 82 countries: 1) states' global influence and 2) self-interest in addressing AMR. World Bank GDP ranking was used as a proxy for global influence, while human antibiotic consumption (10-year percent change) was used as a proxy for self-interest in addressing AMR. We used these data to outline a typology of four country archetypes, and discuss how these archetypes can be used to understand whether a proposed agreement may have sufficient support to be politically feasible. Four types of countries exist within our proposed typology: 1) wealthy countries who have the expertise and financial resources to push for global collective action on AMR, 2) wealthy countries who need to act on AMR, 3) countries who require external assistance to act on AMR, and 4) neutral countries who may support action where applicable. Any international agreement will require substantial support from countries of the first type to lead global action, and from countries of the second type who have large increasing antimicrobial consumption levels. A large number of barriers exist that could derail efforts towards global collective action on AMR; issues of capacity, infrastructure, regulation, and stakeholder interests will need to be addressed in coordination with other actors to achieve an agreement on AMR. Achieving a global agreement on

  2. Erosion resistance of pipe bends with bio-inspired internal surfaces

    Science.gov (United States)

    Zhang, Chengchun; Matar, Omar

    2013-11-01

    Guided by the structure of a shell surface, a bio-inspired surface is proposed to enhance the erosion resistance of pipe bends carrying crude-oil and sand in the turbulent flow regime. A comparison of the erosion rate between a smooth bend and the bio-inspired one is carried out using numerical simulations: large eddy simulations are used to simulate turbulence, and these are coupled to a discrete element method for the solid particles. The results indicate that the bio-inspired surface can control effectively the liquid-solid flow near the wall, and decrease the particle-wall force. This, then, leads to a reduction in the erosion rate brought about by the sand transported by the crude-oil in the pipe bend. The China Scholarship Council is gratefully acknowledged.

  3. A tracer diffusion model derived from microstructure

    International Nuclear Information System (INIS)

    Lehikoinen, Jarmo; Muurinen, Arto; Olin, Markus

    2012-01-01

    Document available in extended abstract form only. Full text of publication follows: Numerous attempts have been made to explain the tracer diffusion of various solutes in compacted clays. These attempts have commonly suffered from an inability to describe the diffusion of uncharged and charged solutes with a single unified model. Here, an internally consistent approach to describing the diffusion of solutes in a heterogeneous porous medium, such as compacted bentonite, in terms of its microstructure is presented. The microstructure is taken to be represented by a succession of unit cells, which consist of two consecutive regions (Do, 1996). In the first region, the diffusion is viewed to occur in two parallel paths: one through microcrystalline units (micropores) and the other through meso-pores between the microcrystalline units. Solutes exiting these two paths are then joined together to continue diffusing through the second, disordered, region, connecting the two adjacent microcrystalline units. Adsorption (incl. co-ion exclusion) is thought to occur in the micropores, whereas meso-pores and the disordered region accommodate free species alone. Co-ions are also assumed to experience transfer resistance into and out of the micropores, which is characterized in the model by a transmission coefficient. Although the model is not new per se, its application to compacted clays has never been attempted before. It is shown that in the limit of strong adsorption, the effective diffusivity is limited from above only by the microstructural parameters of the model porous medium. As intuitive and logical as this result may appear, it has not been proven before. In the limit of vanishing disordered region, the effective diffusivity is no longer explicitly constrained by any of the model parameters. The tortuosity of the diffusion path, i.e. the quotient of the actual diffusion path length in the porous-medium coordinates and the characteristic length of the laboratory frame

  4. International expert consensus statement: Percutaneous transluminal renal denervation for the treatment of resistant hypertension.

    Science.gov (United States)

    Schlaich, Markus P; Schmieder, Roland E; Bakris, George; Blankestijn, Peter J; Böhm, Michael; Campese, Vito M; Francis, Darrel P; Grassi, Guido; Hering, Dagmara; Katholi, Richard; Kjeldsen, Sverre; Krum, Henry; Mahfoud, Felix; Mancia, Giuseppe; Messerli, Franz H; Narkiewicz, Krzysztof; Parati, Gianfranco; Rocha-Singh, Krishna J; Ruilope, Luis M; Rump, Lars C; Sica, Domenic A; Sobotka, Paul A; Tsioufis, Costas; Vonend, Oliver; Weber, Michael A; Williams, Bryan; Zeller, Thomas; Esler, Murray D

    2013-12-03

    Catheter-based radiofrequency ablation technology to disrupt both efferent and afferent renal nerves has recently been introduced to clinical medicine after the demonstration of significant systolic and diastolic blood pressure reductions. Clinical trial data available thus far have been obtained primarily in patients with resistant hypertension, defined as standardized systolic clinic blood pressure ≥ 160 mm Hg (or ≥ 150 mm Hg in patients with type 2 diabetes) despite appropriate pharmacologic treatment with at least 3 antihypertensive drugs, including a diuretic agent. Accordingly, these criteria and blood pressure thresholds should be borne in mind when selecting patients for renal nerve ablation. Secondary forms of hypertension and pseudoresistance, such as nonadherence to medication, intolerance of medication, and white coat hypertension, should have been ruled out, and 24-h ambulatory blood pressure monitoring is mandatory in this context. Because there are theoretical concerns with regard to renal safety, selected patients should have preserved renal function, with an estimated glomerular filtration rate ≥ 45 ml/min/1.73 m(2). Optimal periprocedural management of volume status and medication regimens at specialized and experienced centers equipped with adequate infrastructure to cope with potential procedural complications will minimize potential patient risks. Long-term safety and efficacy data are limited to 3 years of follow-up in small patient cohorts, so efforts to monitor treated patients are crucial to define the long-term performance of the procedure. Although renal nerve ablation could have beneficial effects in other conditions characterized by elevated renal sympathetic nerve activity, its potential use for such indications should currently be limited to formal research studies of its safety and efficacy. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  5. A validation of the new definition of drug-resistant epilepsy by the International League Against Epilepsy.

    Science.gov (United States)

    Téllez-Zenteno, Jose F; Hernández-Ronquillo, Lizbeth; Buckley, Samantha; Zahagun, Ricardo; Rizvi, Syed

    2014-06-01

    To establish applicability, the recently proposed International League Against Epilepsy (ILAE) consensus on drug-resistant epilepsy (DRE) requires testing in clinical and research settings. This study evaluates the reliability and validity of these criteria in a clinical population. In phase I, two independent evaluators reviewed 97 randomly selected medical records of patients with epilepsy at two separate intervals. Both ILEA consensus and standard diagnostic criteria were employed. Kappa, weighted kappa, and intraclass correlation coefficient (ICC) were used to determine interobserver and intraobserver variability. In phase II, ILAE consensus criteria were applied to 250 patients with epilepsy to determine risk factors associated with development of DRE and to calculate point prevalence. The interobserver agreement of the four definitions was as follows: Berg (0.56), Kwan and Brodie (0.58), Camfield and Camfield (0.69), and ILAE (0.77). The intraobserver agreement of the four definition was as follows: Berg (0.81), Kwan and Brodie (0.82), Camfield and Camfield (0.72), and ILAE (0.82). The prevalence of DRE was the following: with the Berg's definition was 28.4%, Kwan and Brodie 34%, Camfield and Camfield 37%, and with ILAE was 33%. This is first study to establish reliability and validity of ILAE criteria for the diagnosis of DRE. This new definition compares favorably with previously established constructs, which continue to retain clinical significance. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

  6. Joint project of the international network of agencies for health technology assessment--Part 1: Survey results on diffusion, assessment, and clinical use of positron emission tomography.

    Science.gov (United States)

    Hastings, John; Adams, Elizabeth J

    2006-01-01

    The International Network of Agencies for Health Technology Assessment (INAHTA) has been tracking activities associated with the clinical use of positron emission tomography (PET) in its members' healthcare systems since 1997 and published its first Joint Project report on PET in 1999. Part 1 of this Joint Project report presents survey results on diffusion, assessment activities, and policy for clinical use related to PET among INAHTA members since 1999. INAHTA members were surveyed in 2003-2004. Twenty-seven INAHTA agencies (69 percent response rate) from nineteen countries responded to the survey. Dedicated PET systems are the most universally installed systems to date. Mobile scanners and modified gamma cameras are used occasionally as lower cost alternatives, and interest in PET-computed tomography hybrid models is rising despite limited assessment of impact on service planning. PET was used and assessed most commonly for managing patients with cancer. All respondents reported having some form of public funding for clinical PET frequently linked to data collection for the purpose of gathering evidence to refine clinical use and guide resource allocation toward indications that maximize clinical and cost-effectiveness. The use of HTA within a continuous quality improvement framework can help optimize scarce resources for evaluation and use of high cost diagnostic technologies such as PET, particularly where potential clinical or cost-effectiveness is considerable but conclusive evidence is lacking.

  7. Fabrication of seven-core multi-filamentary MgB2 wires with high critical current density by an internal Mg diffusion process

    International Nuclear Information System (INIS)

    Togano, K; Hur, J M; Matsumoto, A; Kumakura, H

    2009-01-01

    We found that the reaction between a Mg core and a B powder layer in an internal Mg diffusion (IMD)-processed multi-filamentary wire can proceed rapidly even at a furnace temperature lower than the melting point of Mg (650 deg. C), resulting in the formation of a reacted layer with a fine composite structure and, hence, excellent in-field critical current properties. The multi-filamentary wire is composed of an outermost Cu-Ni sheath and seven filaments with a Ta sheath, a Mg core, and B+SiC powder filled in the space between the Ta sheath and the Mg core. Heat treatment at 645 deg. C for 1 h produced a reacted layer with dense composite structure along the inner wall of the Ta sheath and a hole at the center of each core. This reaction probably initiated from the heat generation at the B/Mg interface, resulting in a temperature rise of the Mg core and the occurrence of liquid Mg infiltration. The J c value at 4.2 K for the reacted layer exceeds 10 5 cm -2 at 9 T, which is the highest reported so far for MgB 2 wire, including powder-in-tube (PIT)-processed wires. These results indicate that the IMD process can compete in terms of practical wire fabrication with the conventional PIT process.

  8. Reduction in chlorhexidine efficacy against multi-drug-resistant Acinetobacter baumannii international clone II.

    Science.gov (United States)

    Hayashi, M; Kawamura, K; Matsui, M; Suzuki, M; Suzuki, S; Shibayama, K; Arakawa, Y

    2017-03-01

    Nosocomial infections caused by Acinetobacter baumannii international clone II (IC II) can cause severe clinical outcomes. Differential evaluation of bactericidal efficacy of chlorhexidine gluconate (CHX) and benzethonium chloride (BZT) disinfectants against IC II and non-IC II isolates. Minimum inhibitory concentrations (MICs) of CHX and BZT were determined for 137 A. baumannii IC II, 99 non-IC II and 69 non-baumannii isolates, further classified according to MIC values into disinfectant-reduced susceptible (DRS) and disinfectant-susceptible (DS) groups. Time-kill curves and minimum bactericidal concentrations (MBCs) were evaluated for representative isolates in each group. CHX and BZT MIC 90 s for IC II isolates were 100 and 175mg/L, respectively, but those for non-IC II and non-baumannii isolates were <100mg/L. Nevertheless, time-kill curves indicated that CHX and BZT reduced live bacterial cell number by 5 log 10 for IC II and non-IC II isolates within 30s when used at 1000mg/L, comparable to practical use concentrations. CHX MBC at 30s was 1000mg/L for IC II and non-IC II isolates, and was not influenced by addition of 3% bovine serum albumin (BSA); BZT MBC at 30s was 100mg/L without BSA and increased up to 500mg/L upon addition of BSA. No significant differences in BSA were found between DRS and DS isolates. CHX and BZT were effective against Acinetobacter spp. including IC II at a concentration of 1000mg/L and exposure for at least 30s, but their concentrations should be considered carefully to ensure sufficient effects in both clinical and healthcare settings. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  9. PI3Kδ inhibitor idelalisib in combination with BTK inhibitor ONO/GS-4059 in diffuse large B cell lymphoma with acquired resistance to PI3Kδ and BTK inhibitors.

    Directory of Open Access Journals (Sweden)

    Anella Yahiaoui

    Full Text Available Activated B-cell-like diffuse large B-cell lymphoma relies on B-cell receptor signaling to drive proliferation and survival. Downstream of the B-cell receptor, the key signaling kinases Bruton's tyrosine kinase and phosphoinositide 3-kinase δ offer opportunities for therapeutic intervention by agents such as ibrutinib, ONO/GS-4059, and idelalisib. Combination therapy with such targeted agents could provide enhanced efficacy due to complimentary mechanisms of action. In this study, we describe both the additive interaction of and resistance mechanisms to idelalisib and ONO/GS-4059 in a model of activated B-cell-like diffuse large B-cell lymphoma. Significant tumor regression was observed with a combination of PI3Kδ and Bruton's tyrosine kinase inhibitors in the mouse TMD8 xenograft. Acquired resistance to idelalisib in the TMD8 cell line occurred by loss of phosphatase and tensin homolog and phosphoinositide 3-kinase pathway upregulation, but not by mutation of PIK3CD. Sensitivity to idelalisib could be restored by combining idelalisib and ONO/GS-4059. Further evaluation of targeted inhibitors revealed that the combination of idelalisib and the phosphoinositide-dependent kinase-1 inhibitor GSK2334470 or the AKT inhibitor MK-2206 could partially overcome resistance. Characterization of acquired Bruton's tyrosine kinase inhibitor resistance revealed a novel tumor necrosis factor alpha induced protein 3 mutation (TNFAIP3 Q143*, which led to a loss of A20 protein, and increased p-IκBα. The combination of idelalisib and ONO/GS-4059 partially restored sensitivity in this resistant line. Additionally, a mutation in Bruton's tyrosine kinase at C481F was identified as a mechanism of resistance. The combination activity observed with idelalisib and ONO/GS-4059, taken together with the ability to overcome resistance, could lead to a new therapeutic option in activated B-cell-like diffuse large B-cell lymphoma. A clinical trial is currently underway to

  10. Alkali resistant Ni-loaded yolk-shell catalysts for direct internal reforming in molten carbonate fuel cells

    Science.gov (United States)

    Jang, Won-Jun; Hong, Young Jun; Kim, Hak-Min; Shim, Jae-Oh; Roh, Hyun-Seog; Kang, Yun Chan

    2017-06-01

    A facile and scalable spray pyrolysis process is applied to synthesize multi-shelled Ni-loaded yolk-shell catalysts on various supports (Al2O3, CeO2, ZrO2, and La(OH)3). The prepared catalysts are applied to direct internal reforming (DIR) in a molten carbonate fuel cell (MCFC). Even on exposure to alkali hydroxide vapors, the Ni-loaded yolk-shell catalysts remain highly active for DIR-MCFCs. The Ni@Al2O3 microspheres show the highest conversion (92%) of CH4 and the best stability among the prepared Ni-loaded yolk-shell catalysts. Although the initial CH4 conversion of the Ni@ZrO2 microspheres is higher than that of the Ni@CeO2 microspheres, the Ni@CeO2 microspheres are more stable. The catalytic performance is strongly dependent on the surface area and acidity and also partly dependent on the reducibility. The acidic nature of Al2O3 combined with its high surface area and yolk-shell structure enhances the adsorption of CH4 and resistance against alkali poisoning, resulting in efficient DIR-MCFC reactions.

  11. Heat Conductivity Resistance of Concrete Wall Panel by Water Flowing in Different Orientations of Internal PVC pipe

    Science.gov (United States)

    Umi, N. N.; Norazman, M. N.; Daud, N. M.; Yusof, M. A.; Yahya, M. A.; Othman, M.

    2018-04-01

    Green building technology and sustainability development is current focus in the world nowadays. In Malaysia and most tropical countries the maximum temperature recorded typically at 35°C. Air-conditioning system has become a necessity in occupied buildings, thereby increasing the cost of electric consumption. The aim of this study is to find out the solution in minimizing heat transfer from the external environment and intentions towards going green. In this study, the experimental work includes testing three types of concrete wall panels. The main heat intervention material in this research is 2 inch diameter Polyvinyl Chloride (PVC) pipe embedded at the center of the concrete wall panel, while the EPS foam beads were added to the cement content in the concrete mix forming the outer layer of the wall panel. Water from the rainwater harvesting system is regulated in the PVC pipe to intervene with the heat conductivity through the wall panel. Results from the experimental works show that the internal surface temperature of these heat resistance wall panels is to 3□C lower than control wall panel from plain interlocking bricks.

  12. Association between proximal internal carotid artery steno-occlusive disease and diffuse wall thickening in its petrous segment: a magnetic resonance vessel wall imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaoyi; Li, Dongye [Capital Medical University and Beijing Institute for Brain Disorders, Center for Brain Disorders Research, Beijing (China); Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Zhao, Huilin [Shanghai Jiao Tong University, Department of Radiology, Renji Hospital, School of Medicine, Shanghai (China); Chen, Zhensen; Qiao, Huiyu; He, Le; Li, Rui [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Cui, Yuanyuan [PLA General Hospital, Department of Radiology, Beijing (China); Zhou, Zechen [Philips Research China, Healthcare Department, Beijing (China); Yuan, Chun [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); University of Washington, Department of Radiology, Seattle, WA (United States); Zhao, Xihai [Tsinghua University School of Medicine, Center for Biomedical Imaging Research, Department of Biomedical Engineering, Beijing (China); Beijing Institute for Brain Disorders, Center for Stroke, Beijing (China)

    2017-05-15

    Significant stenosis or occlusion in carotid arteries may lead to diffuse wall thickening (DWT) in the arterial wall of downstream. This study aimed to investigate the correlation between proximal internal carotid artery (ICA) steno-occlusive disease and DWT in ipsilateral petrous ICA. Symptomatic patients with atherosclerotic stenosis (>0%) in proximal ICA were recruited and underwent carotid MR vessel wall imaging. The 3D motion sensitized-driven equilibrium prepared rapid gradient-echo (3D-MERGE) was acquired for characterizing the wall thickness and longitudinal extent of the lesions in petrous ICA and the distance from proximal lesion to the petrous ICA. The stenosis degree in proximal ICA was measured on the time-of-flight (TOF) images. In total, 166 carotid arteries from 125 patients (mean age 61.0 ± 10.5 years, 99 males) were eligible for final analysis and 64 showed DWT in petrous ICAs. The prevalence of severe DWT in petrous ICA was 1.4%, 5.3%, 5.9%, and 80.4% in ipsilateral proximal ICAs with stenosis category of 1%-49%, 50%-69%, 70%-99%, and total occlusion, respectively. Proximal ICA stenosis was significantly correlated with the wall thickness in petrous ICA (r = 0.767, P < 0.001). Logistic regression analysis showed that proximal ICA stenosis was independently associated with DWT in ipsilateral petrous ICA (odds ratio (OR) = 2.459, 95% confidence interval (CI) 1.896-3.189, P < 0.001). Proximal ICA steno-occlusive disease is independently associated with DWT in ipsilateral petrous ICA. (orig.)

  13. Association between proximal internal carotid artery steno-occlusive disease and diffuse wall thickening in its petrous segment: a magnetic resonance vessel wall imaging study

    International Nuclear Information System (INIS)

    Chen, Xiaoyi; Li, Dongye; Zhao, Huilin; Chen, Zhensen; Qiao, Huiyu; He, Le; Li, Rui; Cui, Yuanyuan; Zhou, Zechen; Yuan, Chun; Zhao, Xihai

    2017-01-01

    Significant stenosis or occlusion in carotid arteries may lead to diffuse wall thickening (DWT) in the arterial wall of downstream. This study aimed to investigate the correlation between proximal internal carotid artery (ICA) steno-occlusive disease and DWT in ipsilateral petrous ICA. Symptomatic patients with atherosclerotic stenosis (>0%) in proximal ICA were recruited and underwent carotid MR vessel wall imaging. The 3D motion sensitized-driven equilibrium prepared rapid gradient-echo (3D-MERGE) was acquired for characterizing the wall thickness and longitudinal extent of the lesions in petrous ICA and the distance from proximal lesion to the petrous ICA. The stenosis degree in proximal ICA was measured on the time-of-flight (TOF) images. In total, 166 carotid arteries from 125 patients (mean age 61.0 ± 10.5 years, 99 males) were eligible for final analysis and 64 showed DWT in petrous ICAs. The prevalence of severe DWT in petrous ICA was 1.4%, 5.3%, 5.9%, and 80.4% in ipsilateral proximal ICAs with stenosis category of 1%-49%, 50%-69%, 70%-99%, and total occlusion, respectively. Proximal ICA stenosis was significantly correlated with the wall thickness in petrous ICA (r = 0.767, P < 0.001). Logistic regression analysis showed that proximal ICA stenosis was independently associated with DWT in ipsilateral petrous ICA (odds ratio (OR) = 2.459, 95% confidence interval (CI) 1.896-3.189, P < 0.001). Proximal ICA steno-occlusive disease is independently associated with DWT in ipsilateral petrous ICA. (orig.)

  14. Prevalence of resistance to antibiotics according to International Classification of Diseases (ICD-10) in Boo Ali Sina Hospital of Sari, 2011-2012.

    Science.gov (United States)

    Afshar, Parvaneh; Saravi, Benyamin Mohseni; Nehmati, Ebrahim; Farahabbadi, Ebrahim Bagherian; Yazdanian, Azadeh; Siamian, Hasan; Vahedi, Mohammad

    2013-01-01

    One of the issues in health care delivery system is resistance to antibiotics. Many researches were done to show the causes and antibiotics which was resistance. In most researches the methods of classifying and reporting this resistance were made by researcher, so in this research we examined the International Classification of Diseases 10 the edition (ICD-10). This is a descriptive cross section study; data was collected from laboratory of Boo Ali Sina hospital, during 2011-2012. The check list was designed according the aim of study. Variables were age, bacterial agent, specimen, and antibiotics. The bacteria and resistance were classified with ICD-10. The data were analyzed with SPSS (16) soft ware and the descriptive statistics. Results showed that of the 10198 request for culture and antibiogram, there were 1020(10%) resistance. The specimen were 648 (63.5%) urine, blood 127(12.5%), other secretion 125 (12/3%), sputum 102 (10%), lumbar puncture 8 (0/8%), stool 6 (6/0%) and bone marrow 4 (0.4%). The E coli was the most 413 (40.5%) resistance cause to antibiotics which was coded with B96.2 and the most resistance was to multiple antibiotics 885(86.8%) with the U88 code. The results showed that by using the ICD-10 codes, the study of multiple causes and resistance is possible. The routine usage of coding of the ICD-10 would result to an up to date bank of resistance to antibiotics in every hospitals and useful for physicians, other health care, and health administrations.

  15. International

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    This rubric reports on 10 short notes about international economical facts about nuclear power: Electricite de France (EdF) and its assistance and management contracts with Eastern Europe countries (Poland, Hungary, Bulgaria); Transnuclear Inc. company (a 100% Cogema daughter company) acquired the US Vectra Technologies company; the construction of the Khumo nuclear power plant in Northern Korea plays in favour of the reconciliation between Northern and Southern Korea; the delivery of two VVER 1000 Russian reactors to China; the enforcement of the cooperation agreement between Euratom and Argentina; Japan requested for the financing of a Russian fast breeder reactor; Russia has planned to sell a floating barge-type nuclear power plant to Indonesia; the control of the Swedish reactor vessels of Sydkraft AB company committed to Tractebel (Belgium); the renewal of the nuclear cooperation agreement between Swiss and USA; the call for bids from the Turkish TEAS electric power company for the building of the Akkuyu nuclear power plant answered by three candidates: Atomic Energy of Canada Limited (AECL), Westinghouse (US) and the French-German NPI company. (J.S.)

  16. Low cost fuel cell diffusion layer configured for optimized anode water management

    Science.gov (United States)

    Owejan, Jon P; Nicotera, Paul D; Mench, Matthew M; Evans, Robert E

    2013-08-27

    A fuel cell comprises a cathode gas diffusion layer, a cathode catalyst layer, an anode gas diffusion layer, an anode catalyst layer and an electrolyte. The diffusion resistance of the anode gas diffusion layer when operated with anode fuel is higher than the diffusion resistance of the cathode gas diffusion layer. The anode gas diffusion layer may comprise filler particles having in-plane platelet geometries and be made of lower cost materials and manufacturing processes than currently available commercial carbon fiber substrates. The diffusion resistance difference between the anode gas diffusion layer and the cathode gas diffusion layer may allow for passive water balance control.

  17. Now consider diffusion

    International Nuclear Information System (INIS)

    Dungey, J.W.

    1984-01-01

    The authors want to talk about future work, but first he will reply to Stan Cowley's comment on his naivety in believing in the whole story to 99% confidence in '65, when he knew about Fairfield's results. Does it matter whether you make the right judgment about theories? Yes, it does, particularly for experimentalists perhaps, but also for theorists. The work you do later depends on the judgment you've made on previous work. People have wasted a lot of time developing on insecure or even wrong foundations. Now for future work. One mild surprise the authors have had is that they haven't heard more about diffusion, in two contexts. Gordon Rostoker is yet to come and he may talk about particles getting into the magnetosphere by diffusion. Lots of noise is observed and so diffusion must happen. If time had not been short, the authors were planning to discuss in a handwaving way what sort of diffusion mechanisms one might consider. The other aspect of diffusion he was going to talk about is at the other end of things and is velocity diffusion, which is involved in anomalous resistivity

  18. Performance of the EUCAST disk diffusion method, the CLSI agar screen method, and the Vitek 2 automated antimicrobial susceptibility testing system for detection of clinical isolates of Enterococci with low- and medium-level VanB-type vancomycin resistance

    DEFF Research Database (Denmark)

    Hegstad, Kristin; Giske, Christian G; Haldorsen, Bjørg

    2014-01-01

    faecium (n=18) strains with and without nonsusceptibility to vancomycin was examined blindly in Danish (n=5), Norwegian (n=13), and Swedish (n=10) laboratories using the EUCAST disk diffusion method (n=28) and the CLSI agar screen (n=18) or the Vitek 2 system (bioMérieux) (n=5). The EUCAST disk diffusion...... method (very major error [VME] rate, 7.0%; sensitivity, 0.93; major error [ME] rate, 2.4%; specificity, 0.98) and CLSI agar screen (VME rate, 6.6%; sensitivity, 0.93; ME rate, 5.6%; specificity, 0.94) performed significantly better (P=0.02) than the Vitek 2 system (VME rate, 13%; sensitivity, 0.87; ME...... rate, 0%; specificity, 1). The performance of the EUCAST disk diffusion method was challenged by differences in vancomycin inhibition zone sizes as well as the experience of the personnel in interpreting fuzzy zone edges as an indication of vancomycin resistance. Laboratories using Oxoid agar (P

  19. An international multicenter study of antimicrobial consumption and resistance in Staphylococcus aureus isolates from 15 hospitals in 14 countries

    DEFF Research Database (Denmark)

    Westh, Henrik Torkil; Zinn, Christina Scheel; Rosdahl, Vibeke Thamdrup

    2004-01-01

    of therapeutical subgroups of antimicrobials varied significantly between hospitals. A positive correlation was found between S. aureus resistance to methicillin (MRSA) and consumption of beta-lactam combinations, between resistance to quinolones and consumption of beta-lactam combinations and carbapenems....... Consumption of beta-lactamase-sensitive antibiotics (penicillin) was positively correlated to consumption of beta-lactamase-resistant penicillins and negatively correlated to consumption of carbapenems, quinolones, and glycopeptides, whereas consumption of cephalosporins was positively correlated...

  20. Conservative diffusions

    International Nuclear Information System (INIS)

    Carlen, E.A.

    1984-01-01

    In Nelson's stochastic mechanics, quantum phenomena are described in terms of diffusions instead of wave functions. These diffusions are formally given by stochastic differential equations with extremely singular coefficients. Using PDE methods, we prove the existence of solutions. This reult provides a rigorous basis for stochastic mechanics. (orig.)

  1. Internal (m=1, n=1) and (m=2, n=1) resistive modes in the toroidal tokamak with circular cross-section

    International Nuclear Information System (INIS)

    Bussac, M.N.; Pellat, R.; Edery, D.; Soule, J.L.

    1977-01-01

    A linear analysis is presented of the toroidal coupling between the internal resistive modes (m=1, n=1) and (m=2, n=1) in the tokamak with circular cross-section. The resistive and diamagnetic effects are included in the singular layers where the safety factor q takes respectively the values one and two. By expanding the MHD equations in powers of epsilon, the local inverse of the aspect ratio, a system of two coupled equations is obtained for the harmonic amplitudes. When the shear is finite on q=1 the toroidal coupling is negligible. In the opposite limit, one can explain (a) the experimental behaviour of the (m=1, n=1) mode before the internal disruption, and (b) the simultaneous observation of the modes (m=1, n=1) and (m=2, n=1) before the main disruption. (author)

  2. [Adherence to international recommendations in the fight against antimicrobial resistance - Substantial difference between outpatient consumption in Spain and Denmark].

    Science.gov (United States)

    Malo, Sara; Rabanaque, María José; Bjerrum, Lars

    2016-02-01

    Increasing antibiotic resistance represents a major public health threat that jeopardises the future treatment of bacterial infections. This study aims to describe the adherence to recommendations proposed by the World Health Organization (WHO) Advisory Group on Integrated Surveillance of Antimicrobial Resistance (AGISAR), in Spain and Denmark, and to analyse the relation between the outpatient use of Critically Important Antimicrobials (CIA) and the bacterial resistance rates to these agents. The Antimicrobial consumption interactive database (ESAC-Net) and Antimicrobial resistance interactive database (EARS-Net) provided data on outpatient use (2010-2013) of CIA (fluoroquinolones, macrolides, and 3rd and 4th generation cephalosporins) and the percentages of isolates of the main pathogens causing serious infections, resistant to these agents. The use of cephalosporins and fluoroquinolones, as well as the percentage of bacteria resistant, is higher in Spain than in Denmark. Although consumption of macrolides in both countries is similar, the proportion of Streptococcus pneumoniae resistant to macrolides is significantly higher in Spain. The high outpatient consumption of CIA agents in Spain deviates substantially from the WHO recommendations. Moreover, it has the effect of elevated rates of antimicrobial resistance, that are lower in Denmark.

  3. Presentación atípica de piomiositis tropical difusa de psoas por Staphylococcus aureus meticilino resistente Atypical presentation of diffuse tropical pyomiositis of the psoas due to methicillin resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Ray Ticse

    2012-03-01

    Full Text Available La piomiositis tropical difusa primaria es una enfermedad de presentación infrecuente en nuestro medio, con pocos casos asociados a Staphylococcus aureus meticilino resistente, adquirido en la comunidad (MRSA-AC. Se presenta el caso de un paciente de 70 años, con tratamiento irregular para diabetes mellitus tipo 2, que fue hospitalizado por presentar un cuadro de diez días de evolución, con dolor lumbar irradiado a miembro inferior izquierdo, fiebre y flexión forzada de la cadera derecha por dolor a la movilización. El diagnóstico de piomiositis difusa de ambos psoas se realizó con resonancia magnética. Del cultivo de una colección paravertebral posterior se aisló Staphylococcus aureus resistente a oxacilina, penicilina y dicloxacilina.Diffuse tropical primary pyomyositis is an infrequent entity in our country, with few cases associated to communityacquired Methicillin- resistant Staphylococcus aureus. There are no reported cases of Community-Acquired Methicillin- Resistant Staphylococcus aureus (CA- MRSA in Peru. We present the case of a 70 year old male with a previous diagnosis of type 2 diabetes mellitus, receiving irregular treatment, who was admitted to the hospital with a history of 10 days of low back pain radiating to the left leg, fever and forced flexion of the right hip due to pain during movement. The diagnosis of diffuse pyomyositis of both psoas muscles was performed with MRI and culture of a posterior paravertebral collection, from which Staphylococcus aureus resistant to oxacillin, penicillin and dicloxacillin was isolated.

  4. Resist image quality control via acid diffusion constant and/or photodecomposable quencher concentration in the fabrication of 11 nm half-pitch line-and-space patterns using extreme-ultraviolet lithography

    Science.gov (United States)

    Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

    2018-05-01

    Extreme-ultraviolet (EUV) lithography will be applied to the high-volume production of semiconductor devices with 16 nm half-pitch resolution and is expected to be extended to that of devices with 11 nm half-pitch resolution. With the reduction in the feature sizes, the control of acid diffusion becomes a significant concern. In this study, the dependence of resist image quality on T PEB D acid and photodecomposable quencher concentration was investigated by the Monte Carlo method on the basis of the sensitization and reaction mechanisms of chemically amplified EUV resists. Here, T PEB and D acid are the postexposure baking (PEB) time and the acid diffusion constant, respectively. The resist image quality of 11 nm line-and-space patterns is discussed in terms of line edge roughness (LER) and stochastic defect generation. For the minimization of LER, it is necessary to design and control not only the photodecomposable quencher concentration but also T PEB D acid. In this case, D acid should be adjusted to be 0.3–1.5 nm2 s‑1 for a PEB time of 60 s with optimization of the balance among LER and stochastic pinching and bridging. Even if it is difficult to decrease D acid to the range of 0.3–1.5 nm2 s‑1, the image quality can still be controlled via only the photodecomposable quencher concentration, although LER and stochastic pinching and bridging are slightly increased. In this case, accurate control of the photodecomposable quencher concentration and the reduction in the initial standard deviation of the number of protected units are required.

  5. Inner structure of La Fossa di Vulcano (Vulcano Island, southern Tyrrhenian Sea, Italy) revealed by high-resolution electric resistivity tomography coupled with self-potential, temperature, and CO2 diffuse degassing measurements

    OpenAIRE

    Revil , A.; Finizola , Anthony; Piscitelli , A.; Rizzo , E.; Ricci , T.; Crespy , A.; Angeletti , B.; Balasco , M.; Barde-Cabusson , Stéphanie; Bennati , L.; Boleve , A.; Byrdina , S.; Carzaniga , N.; Di Gangi , F.; Morin , Julie

    2008-01-01

    International audience; La Fossa cone is an active stratovolcano located on Vulcano Island in the Aeolian Archipelago (southern Italy). Its activity is characterized by explosive phreatic and phreatomagmatic eruptions producing wet and dry pyroclastic surges, pumice fall deposits, and highly viscous lava flows. Nine 2-D electrical resistivity tomograms (ERTs; electrode spacing 20 m, with a depth of investigation >200 m) were obtained to image the edifice. In addition, we also measured the sel...

  6. Emergence of rifampicin, tigecycline, and colistin-resistant Acinetobacter baumannii in Iran; spreading of MDR strains of novel International Clone variants.

    Science.gov (United States)

    Bahador, Abbas; Taheri, Mohammad; Pourakbari, Babak; Hashemizadeh, Zahra; Rostami, Hossein; Mansoori, Noormohamad; Raoofian, Reza

    2013-10-01

    Multidrug-resistant Acinetobacter baumannii infections are serious challenges for clinicians because of A. baumannii propensity to acquire resistance to a wide spectrum of antimicrobial agents. In this study, 91 A. baumannii isolates from patients in tertiary intensive care units of three university hospitals in the north, central, and south of Iran were selected and tested for susceptibility to 22 antimicrobials; amplified restriction fragment polymorphism and multiplex polymerase chain reaction methods were used to determine genetic relationships and International Clone (IC) of A. baumannii isolates, respectively. Twenty-four genotypes were identified in A. baumannii isolates. About 91.2% of isolates categorized into 4 distinct clusters; one was more heterogeneous and observed across the three locations. A considerable number of the isolates (27.5%) belonged to the novel IC variant, sequence group 7 (SG7), which was geographically widespread in three locations. The drug resistance pattern showed that 14.2%, 20%, and 77% of the A. baumannii isolates were resistant to colistin, tigecycline, and rifampicin, respectively. Nine percent of isolates (8) showed simultaneous resistance to colistin, rifampicin, and tigecycline. Interestingly, all of them were susceptible to ampicillin-sulbactam and/or tobramycin. According to our results, SG7 could be considered as a pan-Iranian clone.

  7. Antimicrobial resistance and the guidelines of the International Cooperation on Harmonisation of Technical Requirements for Registration of Veterinary Medicinal Products (VICH).

    Science.gov (United States)

    Marion, H

    2012-04-01

    The International Cooperation on Harmonisation of Technical Requirements for Registration of Veterinary Medicinal Products (VICH) is an international tripartite cooperation programme that brings together regulatory authorities and industry representatives from the European Union, Japan and the United States, with Australia, New Zealand and Canada as observers. VICH aims to improve international coordination and cooperation to achieve greater harmonisation of the requirements for veterinary product registration in the regions concerned. VICH develops harmonised data requirements, i.e., standards for the scientific studies on quality, safety and efficacy that are required to obtain a marketing authorisation for a veterinary medicinal product. It does this by publishing guidelines that provide uniform and consistent guidance for sponsors to follow in developing data for application dossiers as well as for post-marketing safety monitoring of veterinary medicinal products. Of the 49 VICH guidelines that have been developed so far, two guidelines in particular address issues related to antimicrobial resistance.

  8. [Prevalence and predisposing factors of methicillin-resistant Staphylococcus aureus in long-term care facilities. An international view].

    Science.gov (United States)

    Szabó, Rita

    2016-07-03

    Methicillin-resistant Staphylococcus aureus is one of the most important pathogens of healthcare and long-term care-associated infections over the world, resulting high morbidity, mortality and extra costs in these settings. The authors analyze the prevalence and predisposing factors of methicillin-resistant Staphylococcus aureus in long-term care facilities. Systematic review using PubMed, ScienceDirect and Cochrane Library CENTRAL databases between January 1, 2006 and December 31, 2015 was performed. In the past ten years methicillin-resistant Staphylococcus aureus prevalence in European long-term care facilities (12.6%) was lower than in North America (33.9%). The most frequent predisposing factor was previous antimicrobial therapy, hospital admission and infection/colonisation, chronic wounds, and high care need. Based on the results, the prevention and control of methicillin-resistant Staphylococcus aureus is an important public health priority in the European and Hungarian long-term care facilities.

  9. High-temperature resistant, thermally sprayed diffusion barrier coatings on CFC lightweight materials; Hochtemperaturbestaendige, thermisch gespritzte Diffusionsbarriereschichten auf CFC-Leichtbauchargiergestellen

    Energy Technology Data Exchange (ETDEWEB)

    Drehmann, Rico; Rupprecht, Christian; Wielage, Bernhard; Lampke, Thomas [Technische Univ. Chemnitz (Germany). Inst. fuer Werkstoffwissenschaft und Werkstofftechnik (IWW); Gilbert, Maria; Uhlig, Volker; Trimis, Dimosthenis [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Waermetechnik und Thermodynamik (IWTT); Heuer, Volker [ALD Vacuum Technologies GmbH, Hanau (Germany)

    2013-03-15

    In heat treating processes as well as in high temperature brazing processes, charge carriers enable the positioning and transport of work pieces. Recently, charge carriers consisting of graphite or carbon fibre reinforced carbon (CFC) are used. The main disadvantage of charge carriers based on CFC is the undesirable carburization of the overlying components due to diffusion processes. Under this aspect, thermally sprayed coatings are applied on CFC and tested with respect to their suitability as a high-temperature diffusion barrier. The ceramic powders aluminium oxide, aluminium oxide/chromium oxide, aluminium oxide/titanium oxide and zirconium oxide/yttrium oxide are used as a coating material which is processed by means of the powder flame spraying as well as atmospheric plasma spraying. Molybdenum and silicon carbide are used as an adhesive layer. The coating materials aluminium oxide and aluminium oxide/chromium oxide on siliconized CFC presented excellent results. This supplies a large potential of application for thermally sprayed ceramic coatings on carbon-based lightweight materials.

  10. Une analyse empirique de l'information volontaire sur le contrôle interne diffusée par les entreprises françaises

    OpenAIRE

    Lionel Escaffre

    2007-01-01

    National audience; The recent financial crisis has generated a law about the production of a internal control report writen by management directory. This law is issued from Sarbanes-Oxley act which want develop more transparency in fiancial informations. Internal controle is founded on two items : Protection of the assets and Performance. For ten Years, many companies discloses informations on internal control in the intellectuel capital information. We propose a study on the voluntary inform...

  11. Fractional Diffusion Equations and Anomalous Diffusion

    Science.gov (United States)

    Evangelista, Luiz Roberto; Kaminski Lenzi, Ervin

    2018-01-01

    Preface; 1. Mathematical preliminaries; 2. A survey of the fractional calculus; 3. From normal to anomalous diffusion; 4. Fractional diffusion equations: elementary applications; 5. Fractional diffusion equations: surface effects; 6. Fractional nonlinear diffusion equation; 7. Anomalous diffusion: anisotropic case; 8. Fractional Schrödinger equations; 9. Anomalous diffusion and impedance spectroscopy; 10. The Poisson–Nernst–Planck anomalous (PNPA) models; References; Index.

  12. Effect of internal short fibers, steel reinforcement, and surface layer on impact and penetration resistance of concrete

    Directory of Open Access Journals (Sweden)

    Ali Abd_Elhakam Aliabdo

    2013-09-01

    Full Text Available This paper presents an experimental program to investigate the impact and penetration resistance of concrete. The research work is divided into two approaches. These approaches are effect of concrete constituents and effect of surface layer. Effect of concrete aggregate type, w/c ratio, fiber type, fiber shape, fiber volume fraction, and steel reinforcement is considered in the first approach. The second approach includes using fiber reinforced concrete and glass fiber reinforced polymer as surface layers. The evaluating tests include standard impact test according to ASTM D 1557 and suggested simulated penetration test to measure the impact and penetration resistance of concrete. The test results of plain and fibrous concrete from ASTM D 1557 method indicated that steel fiber with different configurations and using basalt have a great positive effect on impact resistance of concrete. Moreover, the simulated penetration test indicates that steel fibers are more effective than propylene fibers, type of coarse aggregate has negligible effect, and steel fiber volume fraction has a more significant influence than fiber shape for reinforced concrete test panels. Finally, as expectable, surface properties of tested concrete panels have a significant effect on impact and penetration resistance.

  13. Mass transfer resistance in ASFF reactors for waste water treatment.

    Science.gov (United States)

    Ettouney, H M; Al-Haddad, A A; Abu-Irhayem, T M

    1996-01-01

    Analysis of mass transfer resistances was performed for an aerated submerged fixed-film reactor (ASFF) for the treatment of waste water containing a mixture of sucrose and ammonia. Both external and internal mass transfer resistances were considered in the analysis, and characterized as a function of feed flow-rate and concentration. Results show that, over a certain operating regime, external mass transfer resistance in the system was greater for sucrose removal than ammonia. This is because the reaction rates for carbon removal were much larger than those of nitrogen. As a result, existence of any form of mass transfer resistance caused by inadequate mixing or diffusion limitations, strongly affects the overall removal rates of carbon more than nitrogen. Effects of the internal måss transfer resistance were virtually non-existent for ammonia removal. This behaviour was found over two orders of magnitude range for the effective diffusivity for ammonia, and one order of magnitude for the film specific surface area. However, over the same parameters' range, it is found that sucrose removal was strongly affected upon lowering its effective diffusivity and increasing the film specific surface area.

  14. An International Collaborative Study of Outcome and Prognostic Factors in Patients with Secondary CNS Involvement By Diffuse Large B-Cell Lymphoma

    DEFF Research Database (Denmark)

    El-Galaly, Tarec Christoffer; Cheah, Chan Yoon; Bendtsen, Mette Dahl

    2016-01-01

    ) determine prognostic factors after SCNS.Patients and methods: We performed a retrospective study of patients diagnosed with SCNS during or after frontline immunochemotherapy (R-CHOP or equivalently effective regimens). SCNS was defined as new involvement of the CNS (parenchymal, leptomeningeal, and/or eye......Background: Secondary CNS involvement (SCNS) is a detrimental complication seen in ~5% of patients with diffuse large B-cell lymphoma (DLBCL) treated with modern immunochemotherapy. Data from older series report short survival following SCNS, typically lt;6 months. However, data in patients...

  15. MHD diffuser model test program

    Energy Technology Data Exchange (ETDEWEB)

    Idzorek, J J

    1976-07-01

    Experimental results of the aerodynamic performance of seven candidate diffusers are presented to assist in determining their suitability for joining an MHD channel to a steam generator at minimum spacing. The three dimensional diffusers varied in area ratio from 2 to 3.8 and wall half angle from 2 to 5 degrees. The program consisted of five phases: (1) tailoring a diffuser inlet nozzle to a 15 percent blockage; (2) comparison of isolated diffusers at enthalpy ratios 0.5 to 1.0 with respect to separation characteristics and pressure recovery coefficients; (3) recording the optimum diffuser exit flow distribution; (4) recording the internal flow distribution within the steam generator when attached to the diffuser; and (5) observing isolated diffuser exhaust dynamic characteristics. The 2 and 2-1/3 degree half angle rectangular diffusers showed recovery coefficients equal to 0.48 with no evidence of flow separation or instability. Diffusion at angles greater than these produced flow instabilities and with angles greater than 3 degrees random flow separation and reattachment.

  16. MHD diffuser model test program

    International Nuclear Information System (INIS)

    Idzorek, J.J.

    1976-07-01

    Experimental results of the aerodynamic performance of seven candidate diffusers are presented to assist in determining their suitability for joining an MHD channel to a steam generator at minimum spacing. The three dimensional diffusers varied in area ratio from 2 to 3.8 and wall half angle from 2 to 5 degrees. The program consisted of five phases: (1) tailoring a diffuser inlet nozzle to a 15 percent blockage; (2) comparison of isolated diffusers at enthalpy ratios 0.5 to 1.0 with respect to separation characteristics and pressure recovery coefficients; (3) recording the optimum diffuser exit flow distribution; (4) recording the internal flow distribution within the steam generator when attached to the diffuser; and (5) observing isolated diffuser exhaust dynamic characteristics. The 2 and 2-1/3 degree half angle rectangular diffusers showed recovery coefficients equal to 0.48 with no evidence of flow separation or instability. Diffusion at angles greater than these produced flow instabilities and with angles greater than 3 degrees random flow separation and reattachment

  17. Impact of technology diffusion on economic growth and international competitiveness. Empirical evidence for four East Asian countries; Gijutsu hakyu no koka to Asia keizai no seichoryoku, yushutsu kyosoryoku

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, Y.; Sakurai, N.

    1999-06-01

    Asian economies hit by the currency crisis in 1997 are still in struggle to recover their growth and to boost again their exports. Although several short-term policy measures to stimulate the demand- side of the economy is certainly necessary, in a longer-term perspective, the key to real recovery would exist in their ability to absorb foreign technologies through trade and/or FDI, as stressed by recent new theories of growth and trade. This paper examines empirically the role of technology diffusion from advanced countries to total factor productivity (TFP) and export competitiveness in four major East-Asian countries: Korea, Singapore, Malaysia and Indonesia, three of which were seriously damaged by the currency crisis. Our major findings are summarized as follows. First, we found that technology acquisition from abroad is quite important for TFP growth of most industries in Asia, in particular for two ASEAN countries (Malaysia and Indonesia), while such productivity impact from foreign technology was relatively small for Korea and Singapore. Second, the impact of technology diffusion was much larger in that through trade than in that through foreign direct investment. Some FDI practices to preclude technology access for developing countries might explain such weaker role of FDI on TFP. Third, the nexus between TFP and export competitiveness was surely positive, in particular for industries of high export performance. However, the magnitude of impact was relatively small in Korea, in spite of its overwhelming productivity performance. (author)

  18. Ten key points for the appropriate use of antibiotics in hospitalised patients: a consensus from the Antimicrobial Stewardship and Resistance Working Groups of the International Society of Chemotherapy.

    Science.gov (United States)

    Levy Hara, Gabriel; Kanj, Souha S; Pagani, Leonardo; Abbo, Lilian; Endimiani, Andrea; Wertheim, Heiman F L; Amábile-Cuevas, Carlos; Tattevin, Pierre; Mehtar, Shaheen; Lopes Cardoso, Fernando; Unal, Serhat; Gould, Ian

    2016-09-01

    The Antibiotic Stewardship and Resistance Working Groups of the International Society for Chemotherapy propose ten key points for the appropriate use of antibiotics in hospital settings. (i) Get appropriate microbiological samples before antibiotic administration and carefully interpret the results: in the absence of clinical signs of infection, colonisation rarely requires antimicrobial treatment. (ii) Avoid the use of antibiotics to 'treat' fever: use them to treat infections, and investigate the root cause of fever prior to starting treatment. (iii) Start empirical antibiotic treatment after taking cultures, tailoring it to the site of infection, risk factors for multidrug-resistant bacteria, and the local microbiology and susceptibility patterns. (iv) Prescribe drugs at their optimal dosing and for an appropriate duration, adapted to each clinical situation and patient characteristics. (v) Use antibiotic combinations only where the current evidence suggests some benefit. (vi) When possible, avoid antibiotics with a higher likelihood of promoting drug resistance or hospital-acquired infections, or use them only as a last resort. (vii) Drain the infected foci quickly and remove all potentially or proven infected devices: control the infection source. (viii) Always try to de-escalate/streamline antibiotic treatment according to the clinical situation and the microbiological results. (ix) Stop unnecessarily prescribed antibiotics once the absence of infection is likely. And (x) Do not work alone: set up local teams with an infectious diseases specialist, clinical microbiologist, hospital pharmacist, infection control practitioner or hospital epidemiologist, and comply with hospital antibiotic policies and guidelines. Copyright © 2016. Published by Elsevier B.V.

  19. Diffusion bonding

    International Nuclear Information System (INIS)

    Anderson, R.C.

    1976-01-01

    A method is described for joining beryllium to beryllium by diffusion bonding. At least one surface portion of at least two beryllium pieces is coated with nickel. A coated surface portion is positioned in a contiguous relationship with another surface portion and subjected to an environment having an atmosphere at a pressure lower than ambient pressure. A force is applied on the beryllium pieces for causing the contiguous surface portions to abut against each other. The contiguous surface portions are heated to a maximum temperature less than the melting temperature of the beryllium, and the applied force is decreased while increasing the temperature after attaining a temperature substantially above room temperature. A portion of the applied force is maintained at a temperature corresponding to about maximum temperature for a duration sufficient to effect the diffusion bond between the contiguous surface portions

  20. 5-FU resistant EMT-like pancreatic cancer cells are hypersensitive to photochemical internalization of the novel endoglin-targeting immunotoxin CD105-saporin.

    Science.gov (United States)

    Lund, Kaja; Olsen, Cathrine Elisabeth; Wong, Judith Jing Wen; Olsen, Petter Angell; Solberg, Nina Therese; Høgset, Anders; Krauss, Stefan; Selbo, Pål Kristian

    2017-12-19

    Development of resistance to 5-fluorouracil (5-FU) is a major problem in treatment of various cancers including pancreatic cancer. In this study, we reveal important resistance mechanisms and photochemical strategies to overcome 5-FU resistance in pancreatic adenocarcinoma. 5-FU resistant (5-FUR), epithelial-to-mesenchymal-like sub-clones of the wild type pancreatic cancer cell line Panc03.27 were previously generated in our lab. We investigated the cytotoxic effect of the endosomal/lysosomal-localizing photosensitizer TPCS 2a (fimaporfin) combined with light (photochemical treatment, PCT) using MTS viability assay, and used fluorescence microscopy to show localization of TPCS 2a and to investigate the effect of photodamage of lysosomes. Flow cytometric analysis was performed to investigate uptake of photosensitizer and to assess intracellular ROS levels. Expression and localization of LAMP1 was assessed using RT-qPCR, western blotting, and structured illumination microscopy. MTS viability assay was used to assess the effect of combinations of 5-FU, chloroquine (CQ), and photochemical treatment. Expression of CD105 was investigated using RT-qPCR, western blotting, flow cytometry, and fluorescence microscopy, and co-localization of TPCS 2a and anti-CD105-saporin was assessed using microscopy. Lastly, the MTS assay was used to investigate cytotoxic effects of photochemical internalization (PCI) of the anti-CD105-immunotoxin. The 5-FUR cell lines display hypersensitivity to PCT, which was linked to increased uptake of TPCS 2a , altered lysosomal distribution, lysosomal photodamage and increased expression of the lysosomal marker LAMP-1 in the 5-FUR cells. We show that inhibition of autophagy induced by either chloroquine or lysosomal photodamage increases the sensitivity to 5-FU in the resistant cells. The three 5-FUR sub-clones overexpress Endoglin (CD105). Treatment with the immunotoxin anti-CD105-saporin alone significantly reduced the viability of the CD105

  1. Multipassage diffuser

    International Nuclear Information System (INIS)

    Lalis, A.; Rouviere, R.; Simon, G.

    1976-01-01

    A multipassage diffuser having 2p passages comprises a leak-tight cylindrical enclosure closed by a top cover and a bottom end-wall, parallel porous tubes which are rigidly assembled in sectors between tube plates and through which the gas mixture flows, the tube sectors being disposed at uniform intervals on the periphery of the enclosure. The top tube plates are rigidly fixed to an annular header having the shape of a half-torus and adapted to communicate with the tubes of the corresponding sector. Each passage is constituted by a plurality of juxtaposed sectors in which the mixture circulates in the same direction, the header being divided into p portions limited by radial partition-walls and each constituting two adjacent passages. The diffuser is provided beneath the bottom end-wall with p-1 leak-tight chambers each adapted to open into two different portions of the header, and with two collector-chambers each fitted with a nozzle for introducing the gas mixture and discharging the fraction of the undiffused mixture. By means of a central orifice formed in the bottom end-wall the enclosure communicates with a shaft for discharging the diffused fraction of the gas mixture

  2. Resistance to temptation: the interaction of external and internal control on alcohol use during residential treatment for alcohol use disorder.

    Science.gov (United States)

    Soravia, Leila M; Schläfli, Katrin; Stutz, Sonja; Rösner, Susanne; Moggi, Franz

    2015-11-01

    There is evidence that drinking during residential treatment is related to various factors, such as patients' general control beliefs and self-efficacy, as well as to external control of alcohol use by program's staff and situations where there is temptation to drink. As alcohol use during treatment has been shown to be associated with the resumption of alcohol use after discharge from residential treatment, we aimed to investigate how these variables are related to alcohol use during abstinence-oriented residential treatment programs for alcohol use disorders (AUD). In total, 509 patients who entered 1 of 2 residential abstinence-oriented treatment programs for AUD were included in the study. After detoxification, patients completed a standardized diagnostic procedure including interviews and questionnaires. Drinking was assessed by patients' self-report of at least 1 standard drink or by positive breathalyzer testing. The 2 residential programs were categorized as high or low control according to the average number of tests per patient. Regression analysis revealed a significant interaction effect between internal and external control suggesting that patients with high internal locus of control and high frequency of control by staff demonstrated the least alcohol use during treatment (16.7%) while patients with low internal locus of control in programs with low external control were more likely to use alcohol during treatment (45.9%). No effects were found for self-efficacy and temptation. As alcohol use during treatment is most likely associated with poor treatment outcomes, external control may improve treatment outcomes and particularly support patients with low internal locus of control, who show the highest risk for alcohol use during treatment. High external control may complement high internal control to improve alcohol use prevention while in treatment. Copyright © 2015 The Authors. Alcoholism: Clinical and Experimental Research published by Wiley

  3. A method to determine the kink resistance of stents and stent delivery systems according to international standards

    Directory of Open Access Journals (Sweden)

    Brandt-Wunderlich Christoph

    2016-09-01

    Full Text Available The kink behavior of vascular stents is of particular interest for clinicians, stent manufacturers and regulatory as a kinked stent generates a lumen loss in the stented vessel and can lead to in-stent restenosis. In this study methods to determine the kink resistance of stents and stent delivery systems according to the ISO 25539-2 and FDA guidance no. 1545 were presented. The methods are applicable for balloon expandable stents as well as for self-expanding stents and determine the lumen loss and residual diameter change dependent on the specific bending radius.

  4. Development plates for stable internal fixation: Study of mechanical resistance in simulated fractures of the mandibular condyle.

    Science.gov (United States)

    Celegatti Filho, Tóride Sebastião; Rodrigues, Danillo Costa; Lauria, Andrezza; Moreira, Roger William Fernandes; Consani, Simonides

    2015-01-01

    To develop Y-shaped plates with different thicknesses to be used in simulated fractures of the mandibular condyle. Ten plates were developed in Y shape, containing eight holes, and 30 synthetic polyurethane mandible replicas were developed for the study. The load test was performed on an Instron Model 4411 universal testing machine, applying load in the mediolateral and anterior-posterior positions on the head of the condyle. Two-way ANOVA with Tukey testing with a 5% significance level was used. It was observed that when the load was applied in the medial-lateral plate of greater thickness (1.5 mm), it gave the highest strength, while in the anteroposterior direction, the plate with the highest resistance was of the lesser thickness (0.6 mm). A plate with a thickness of 1.5 mm was the one with the highest average value for all displacements. In the anteroposterior direction, the highest values of resistance were seen in the displacement of 15 mm. After comparing the values of the biomechanical testing found in the scientific literature, it is suggested that the use of Y plates are suitable for use in subcondylar fractures within the limitations of the study. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  5. Effect of external and internal factors on the expression of reporter genes driven by the N resistance gene promoter.

    Science.gov (United States)

    Kathiria, Palak; Sidler, Corinne; Woycicki, Rafal; Yao, Youli; Kovalchuk, Igor

    2013-07-01

    The role of resistance (R) genes in plant pathogen interaction has been studied extensively due to its economical impact on agriculture. Interaction between tobacco mosaic virus (TMV) and the N protein from tobacco is one of the most widely used models to understand various aspects of pathogen resistance. The transcription activity governed by N gene promoter is one of the least understood elements of the model. In this study, the N gene promoter was cloned and fused with two different reporter genes, one encoding β-glucuronidase (N::GUS) and another, luciferase (N::LUC). Tobacco plants transformed with the N::GUS or N::LUC reporter constructs were screened for homozygosity and stable expression. Histochemical analysis of N::GUS tobacco plants revealed that the expression is organ specific and developmentally regulated. Whereas two week old plants expressed GUS in midveins only, 6-wk-old plants also expressed GUS in leaf lamella. Roots did not show GUS expression at any time during development. Experiments to address effects of external stress were performed using N::LUC tobacco plants. These experiments showed that N gene promoter expression was suppressed when plants were exposed to high but not low temperatures. Expression was also upregulated in response to TMV, but no changes were observed in plants treated with SA.

  6. Global Banning of a Diffused Controversial Practice

    DEFF Research Database (Denmark)

    Gurses, Kerem; Giones, Ferran; Mehta, Kandarpkumar

    2017-01-01

    We study the deinstitutionalization of a controversial practice that had previously reached a level of international diffusion. We draw on international diffusion and deinstitutionalization theory to study the emergence and diffusion of the third-party ownership practice in the soccer industry. We...... use an inductive case study combining archival and interview data to study the determinants of the international diffusion of a controversial practice at a global scale, the contestation, and finally the deinstitutionalization process that resulted from the ban of the practice. We find...... that the opacity of the practice can be a diffusion driver, locally and at the international level, nevertheless the opacity also may lead to different meaning creation attempts and potential discursive battles between actors, and eventually to deinstitutionalization of the practice. This article advances our...

  7. Quantum diffusion

    International Nuclear Information System (INIS)

    Habib, S.

    1994-01-01

    We consider a simple quantum system subjected to a classical random force. Under certain conditions it is shown that the noise-averaged Wigner function of the system follows an integro-differential stochastic Liouville equation. In the simple case of polynomial noise-couplings this equation reduces to a generalized Fokker-Planck form. With nonlinear noise injection new ''quantum diffusion'' terms rise that have no counterpart in the classical case. Two special examples that are not of a Fokker-Planck form are discussed: the first with a localized noise source and the other with a spatially modulated noise source

  8. Hereditary Diffuse Gastric Cancer

    Science.gov (United States)

    ... Hereditary Diffuse Gastric Cancer Request Permissions Hereditary Diffuse Gastric Cancer Approved by the Cancer.Net Editorial Board , 10/2017 What is hereditary diffuse gastric cancer? Hereditary diffuse gastric cancer (HDGC) is a rare ...

  9. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 41: Technical communication practices of Dutch and US aerospace engineers and scientists: International perspective on aerospace

    Science.gov (United States)

    Barclay, Rebecca O.; Pinelli, Thomas E.; Kennedy, John M.

    1994-01-01

    As part of Phase 4 of the NASA/DOD Aerospace Knowledge Diffusion Research Project, studies were conducted that investigated the technical communications practices of Dutch and U.S. aerospace engineers and scientists. The studies had the following objectives: (1) to solicit the opinions of aerospace engineers and scientists regarding the importance of technical communication to their professions, (2) to determine the use and production of technical communication by aerospace engineers and scientists, (3) to investigate their use of libraries and technical information centers, (4) to investigate their use of and the importance to them of computer and information technology, (5) to examine their use of electronic networks, and (6) to determine their use of foreign and domestically produced technical reports. Self-administered (mail) questionnaires were distributed to Dutch aerospace engineers and scientists at the National Aerospace Laboratory (NLR) in the Netherlands, the NASA Ames Research Center in the U.S., and the NASA Langley Research Center in the U.S. Responses of the Dutch and U.S. participants to selected questions are presented in this paper.

  10. 3D-CFD analysis of diffusion and emission of VOCs in a FLEC cavity.

    Science.gov (United States)

    Zhu, Q; Kato, S; Murakami, S; Ito, K

    2007-06-01

    This study is performed as a part of research that examines the emission and diffusion characteristics of volatile organic compounds (VOCs) from indoor building materials. In this paper, the flow field and the emission field of VOCs from the surface of building materials in a Field and Laboratory Emission Cell (FLEC) cavity are examined by 3D Computational Fluid Dynamics (CFD) analysis. The flow field within the FLEC cavity is laminar. With a total flow of 250 ml/min, the air velocity near the test material surface ranges from 0.1 to 4.5 cm/s. Three types of emission from building materials are studied here: (i) emission phenomena controlled by internal diffusion, (ii) emission phenomena controlled by external diffusion, and (iii) emission phenomena controlled by mixed diffusion (internal + external diffusion). In the case of internal diffusion material, with respect to the concentration distribution in the cavity, the local VOC emission rate becomes uniform and the FLEC works well. However, in the case of evaporation type (external diffusion) material, or mixed type materials (internal + external diffusion) when the resistance to transporting VOCs in the material is small, the FLEC is not suitable for emission testing because of the thin FLEC cavity. In this case, the mean emission rate is restricted to a small value, since the VOC concentration in the cavity rises to the same value as the surface concentration through molecular diffusion within the thin cavity, and the concentration gradient normal to the surface becomes small. The diffusion field and emission rate depend on the cavity concentration and on the Loading Factor. That is, when the testing material surface in the cavity is partially sealed to decrease the Loading Factor, the emission rate become higher with the decrease in the exposed area of the testing material. The flow field and diffusion field within the FLEC cavity are investigated by CFD method. After presenting a summary of the velocity

  11. International cooperation project. Evaluation report on development of new oxidation and environment resistant materials for petroleum excavation; Sekiyu kussakuyo taisankasei taikankyosei shinzairyo no kaihatsu hyoka hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    In order to enhance the environment and wear resisting performance of the bearing mechanism for petroleum excavation bits assuming use at a depth of 6,000 m, discussions were given on a cubic boron nitride based ultra-hard thin film and a Ti{sub x}M{sub 1-x}N based hard thin film as the new materials. This paper describes the evaluation report for the year 2000. It was found that the promising material is the Ti{sub x}M{sub 1-x}N. The practical applicability test would require a considerable amount of expense and insurance fee, while putting the material into practical use would take some more time. However, the achievements in developing this new material will allow the material to be applied to cutting tools used under the same onerous condition, and theoretical development would be possible on the consideration of the film properties, whereas further development may be expected in the future. An international joint study has performed evaluations on the environmental resistance and the characteristics of the film at the University of Toronto. These evaluations are effective in enhancing further the properties of the thin film in the future. Achievements have been accumulated steadily from starting the fundamental studies, and high level objectives have been achieved. Accurate identification has been made on the state of developing the parts for petroleum excavation bits, with the objectives set properly. Putting the bits into practical use will still require public assistance. (NEDO)

  12. Comparison of ex-USSR norms and current international practice in design of seismic resistant nuclear power plants

    International Nuclear Information System (INIS)

    Hauptenbuchner, B.; David, M.

    1995-01-01

    Seismic hazard has been estimated according to ex-USSR norms in the original designs of WWER type Nuclear Power Plants (NPP) in former Soviet Union as well as in all former east European countries. For some steps of the design the national standards has been also taken into account. The original ex-USSR norms and instructions has been several times changed and improved during the time. This contribution is dealing with the development of ex-USSR norms and regulations with the aim to recognise some most important differentiations in comparison with corresponding western or international ones from point of view of civil structures. The understanding of relations of these documents is very important for seismic qualification and upgrading of WWER-type, NPPs. The main Soviet/Russian Standards and Regulations related to the seismic design and qualification of NPP structures as SNiP II-A.12-69, VSN 15-78, SNiP II-7-81, PiNAE G-7-002-86, NTD SEV etc. have been taken into consideration and compared with western or international standards as IAEA 50-SG-S1, IAEA 50-SG-D15, KTA 2201.1-6, ASCE 4-86 etc. The numerical examples of structural seismic qualification has been elaborated according to different standards for better understanding and in order to determine the degree of safety referring to corresponding standards. The authors has tried also to take into account the way of application of ex-USSR norms. The comparison of different norms and regulations has been analysed and corresponding conclusions and recommendations have been derived. These conclusions and recommendations can be helpful by the seismic qualification and upgrading of WWER-type NPPs. (author)

  13. Inverse diffusion theory of photoacoustics

    International Nuclear Information System (INIS)

    Bal, Guillaume; Uhlmann, Gunther

    2010-01-01

    This paper analyzes the reconstruction of diffusion and absorption parameters in an elliptic equation from knowledge of internal data. In the application of photoacoustics, the internal data are the amount of thermal energy deposited by high frequency radiation propagating inside a domain of interest. These data are obtained by solving an inverse wave equation, which is well studied in the literature. We show that knowledge of two internal data based on well-chosen boundary conditions uniquely determines two constitutive parameters in diffusion and Schrödinger equations. Stability of the reconstruction is guaranteed under additional geometric constraints of strict convexity. No geometric constraints are necessary when 2n internal data for well-chosen boundary conditions are available, where n is spatial dimension. The set of well-chosen boundary conditions is characterized in terms of appropriate complex geometrical optics solutions

  14. Implications of insecticide resistance for malaria vector control with long-lasting insecticidal nets: a WHO-coordinated, prospective, international, observational cohort study.

    Science.gov (United States)

    Kleinschmidt, Immo; Bradley, John; Knox, Tessa Bellamy; Mnzava, Abraham Peter; Kafy, Hmooda Toto; Mbogo, Charles; Ismail, Bashir Adam; Bigoga, Jude D; Adechoubou, Alioun; Raghavendra, Kamaraju; Cook, Jackie; Malik, Elfatih M; Nkuni, Zinga José; Macdonald, Michael; Bayoh, Nabie; Ochomo, Eric; Fondjo, Etienne; Awono-Ambene, Herman Parfait; Etang, Josiane; Akogbeto, Martin; Bhatt, Rajendra M; Chourasia, Mehul Kumar; Swain, Dipak K; Kinyari, Teresa; Subramaniam, Krishanthi; Massougbodji, Achille; Okê-Sopoh, Mariam; Ogouyemi-Hounto, Aurore; Kouambeng, Celestin; Abdin, Mujahid Sheikhedin; West, Philippa; Elmardi, Khalid; Cornelie, Sylvie; Corbel, Vincent; Valecha, Neena; Mathenge, Evan; Kamau, Luna; Lines, Jonathan; Donnelly, Martin James

    2018-04-09

    year in Kenya; and an average infection prevalence in net users of 0·8% [0·5-1·3] in India to an average infection prevalence of 50·8% [43·4-58·2] in Benin). Irrespective of resistance, populations in malaria endemic areas should continue to use long-lasting insecticidal nets to reduce their risk of infection. As nets provide only partial protection, the development of additional vector control tools should be prioritised to reduce the unacceptably high malaria burden. Bill & Melinda Gates Foundation, UK Medical Research Council, and UK Department for International Development. Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.

  15. Development of a Ground-Based Analog to the Advanced Resistive Exercise Device Aboard the International Space Station

    Science.gov (United States)

    Newby, Nathaniel J.; Scott-Pandorf, M. M.; Caldwell, E.; DeWitt, J.K.; Fincke, R.; Peters, B.T.

    2010-01-01

    NASA and Wyle engineers constructed a Horizontal Exercise Fixture (HEF) that was patented in 2006. Recently modifications were made to HEF with the goal of creating a device that mimics squat exercise on the Advanced Resistive Exercise Device (ARED) and can be used by bed rest subjects who must remain supine during exercise. This project posed several engineering challenges, such as how best to reproduce the hip motions (we used a sled that allowed hip motion in the sagittal plane), how to counterweight the pelvis against gravity (we used a pulley and free-weight mechanism), and how to apply large loads (body weight plus squat load) to the shoulders while simultaneously supporting the back against gravity (we tested a standard and a safety bar that allowed movement in the subject s z-axis, both of which used a retractable plate for back support). METHODS An evaluation of the HEF was conducted with human subjects (3F, 3M), who performed sets of squat exercises of increasing load from 10-repetition maximum (RM) up to 1-RM. Three pelvic counterweight loads were tested along with each of the two back-support squat bars. Data collection included 3-dimensional ground reaction forces (GRF), muscle activation (EMG), body motion (video-based motion capture), and subjective comments. These data were compared with previous ground-based ARED study data. RESULTS All subjects in the evaluation were able to perform low- to high-loading squats on the HEF. Four of the 6 subjects preferred a pelvic counterweight equivalent to 60 percent of their body weight. Four subjects preferred the standard squat bar, whereas 2 female subjects preferred the safety bar. EMG data showed muscle activation in the legs and low back typical of squat motion. GRF trajectories and eccentric-concentric loading ratios were similar to ARED. CONCLUSION: Squat exercise performed on HEF approximated squat exercise on ARED.

  16. Dynamic characterization of external and internal mass transport in heterotrophic biofilms from microsensors measurements.

    Science.gov (United States)

    Guimerà, Xavier; Dorado, Antonio David; Bonsfills, Anna; Gabriel, Gemma; Gabriel, David; Gamisans, Xavier

    2016-10-01

    Knowledge of mass transport mechanisms in biofilm-based technologies such as biofilters is essential to improve bioreactors performance by preventing mass transport limitation. External and internal mass transport in biofilms was characterized in heterotrophic biofilms grown on a flat plate bioreactor. Mass transport resistance through the liquid-biofilm interphase and diffusion within biofilms were quantified by in situ measurements using microsensors with a high spatial resolution (mass transport coefficients. The sensitivity of external and internal mass transport resistances to flow conditions within the range of typical fluid velocities over biofilms (Reynolds numbers between 0.5 and 7) was assessed. Estimated external mass transfer coefficients at different liquid phase flow velocities showed discrepancies with studies considering laminar conditions in the diffusive boundary layer near the liquid-biofilm interphase. The correlation of effective diffusivity with flow velocities showed that the heterogeneous structure of biofilms defines the transport mechanisms inside biofilms. Internal mass transport was driven by diffusion through cell clusters and aggregates at Re below 2.8. Conversely, mass transport was driven by advection within pores, voids and water channels at Re above 5.6. Between both flow velocities, mass transport occurred by a combination of advection and diffusion. Effective diffusivities estimated at different biofilm densities showed a linear increase of mass transport resistance due to a porosity decrease up to biofilm densities of 50 g VSS·L(-1). Mass transport was strongly limited at higher biofilm densities. Internal mass transport results were used to propose an empirical correlation to assess the effective diffusivity within biofilms considering the influence of hydrodynamics and biofilm density. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Diffusion in crystalline rocks of some sorbing and nonsorbing species

    International Nuclear Information System (INIS)

    Skagius, K.; Neretnieks, I.

    1983-01-01

    Laboratory experiments to determine the sorption and the rate of diffusion of cesium and strontium in pieces of granite have been performed. The effective diffusivity, D sub (p) x E sub (p) was found to be 1 - 2 x 10 - 12 m 2 /s for both cesium and strontium. The diffusion of non-sorbing species in granites and other rock materials have been studied in laboratory scale. The non-sorbing species were iodide, tritiated water, Cr-EDTA and Uranine. In granites the effective diffusivities were determined to be 0.7-1.3 x 10 - 13 m 2 /s for iodide and 1.3 - 1.8 x 10 - 13 m 2 /s for tritiated water. Electrical resistivity measurements in salt water saturated rock cores have been performed. The resistivity is measured in the saturated core and in the salt solution with which the core has been saturated. The ratio between these two resistivities has a direct relation to the ratio of the effective diffusivity for a component in the rock material and the diffusivity in free water for the same component. The results from the electrical resistivity measurements and the experiments with diffusion of non-sorbing species are in fair agreement. The effective diffusivity for cesium and strontium (sorbing species) are, however, more than ten times higher than expected from the results of diffusion of non-sorbing species and the electrical resistivity measurements. This is interpreted as an effect of surface diffusion. (Authors)

  18. Diffusion archeology for diffusion progression history reconstruction.

    Science.gov (United States)

    Sefer, Emre; Kingsford, Carl

    2016-11-01

    Diffusion through graphs can be used to model many real-world processes, such as the spread of diseases, social network memes, computer viruses, or water contaminants. Often, a real-world diffusion cannot be directly observed while it is occurring - perhaps it is not noticed until some time has passed, continuous monitoring is too costly, or privacy concerns limit data access. This leads to the need to reconstruct how the present state of the diffusion came to be from partial diffusion data. Here, we tackle the problem of reconstructing a diffusion history from one or more snapshots of the diffusion state. This ability can be invaluable to learn when certain computer nodes are infected or which people are the initial disease spreaders to control future diffusions. We formulate this problem over discrete-time SEIRS-type diffusion models in terms of maximum likelihood. We design methods that are based on submodularity and a novel prize-collecting dominating-set vertex cover (PCDSVC) relaxation that can identify likely diffusion steps with some provable performance guarantees. Our methods are the first to be able to reconstruct complete diffusion histories accurately in real and simulated situations. As a special case, they can also identify the initial spreaders better than the existing methods for that problem. Our results for both meme and contaminant diffusion show that the partial diffusion data problem can be overcome with proper modeling and methods, and that hidden temporal characteristics of diffusion can be predicted from limited data.

  19. Device-associated infection rates, mortality, length of stay and bacterial resistance in intensive care units in Ecuador: International Nosocomial Infection Control Consortium’s findings

    Science.gov (United States)

    Salgado Yepez, Estuardo; Bovera, Maria M; Rosenthal, Victor D; González Flores, Hugo A; Pazmiño, Leonardo; Valencia, Francisco; Alquinga, Nelly; Ramirez, Vanessa; Jara, Edgar; Lascano, Miguel; Delgado, Veronica; Cevallos, Cristian; Santacruz, Gasdali; Pelaéz, Cristian; Zaruma, Celso; Barahona Pinto, Diego

    2017-01-01

    AIM To report the results of the International Nosocomial Infection Control Consortium (INICC) study conducted in Quito, Ecuador. METHODS A device-associated healthcare-acquired infection (DA-HAI) prospective surveillance study conducted from October 2013 to January 2015 in 2 adult intensive care units (ICUs) from 2 hospitals using the United States Centers for Disease Control/National Healthcare Safety Network (CDC/NHSN) definitions and INICC methods. RESULTS We followed 776 ICU patients for 4818 bed-days. The central line-associated bloodstream infection (CLABSI) rate was 6.5 per 1000 central line (CL)-days, the ventilator-associated pneumonia (VAP) rate was 44.3 per 1000 mechanical ventilator (MV)-days, and the catheter-associated urinary tract infection (CAUTI) rate was 5.7 per 1000 urinary catheter (UC)-days. CLABSI and CAUTI rates in our ICUs were similar to INICC rates [4.9 (CLABSI) and 5.3 (CAUTI)] and higher than NHSN rates [0.8 (CLABSI) and 1.3 (CAUTI)] - although device use ratios for CL and UC were higher than INICC and CDC/NSHN’s ratios. By contrast, despite the VAP rate was higher than INICC (16.5) and NHSN’s rates (1.1), MV DUR was lower in our ICUs. Resistance of A. baumannii to imipenem and meropenem was 75.0%, and of Pseudomonas aeruginosa to ciprofloxacin and piperacillin-tazobactam was higher than 72.7%, all them higher than CDC/NHSN rates. Excess length of stay was 7.4 d for patients with CLABSI, 4.8 for patients with VAP and 9.2 for patients CAUTI. Excess crude mortality in ICUs was 30.9% for CLABSI, 14.5% for VAP and 17.6% for CAUTI. CONCLUSION DA-HAI rates in our ICUs from Ecuador are higher than United States CDC/NSHN rates and similar to INICC international rates. PMID:28289522

  20. Diffusion welding; Soudage par diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Daniault, J; Gillet, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    After a brief recall of the principle, and of the advantages of the method, we give some examples of metallic bonding in a first part where we describe preliminary trials: Ta-Mo, Zr-Zr, Zr-Nb, Nb-stainless steel, Mo-stainless steel, aluminium-aluminium (A5-A5). The second part of the note is devoted to trials on construction elements: on tubular elements for bonding between Mo or Nb on one hand, and stainless steel on the other hand (We indicate in what conditions the bonding are tight and what are their mechanical strength and their resistance to thermic cycles). We indicate, in this chapter, a method to obtain radiation windows in Be welded on an element made of stainless steel. (authors) [French] pres un bref rappel du principe, et des avantages de la methode, on donne quelques exemples de liaisons metalliques dans une premiere partie qui traite d'essais preliminaires: Ta - Mo, Zr - Zr, Zr - Nb, Nb - acier inoxydable, molybdene - acier inoxydable, aluminium - aluminium (A5-A5). La deuxieme partie de la note est consacree a des essais sur elements de construction: sur des elements tabulaires, pour des liaisons entre molybdene ou niobium d'une part, et acier inoxydable d'autre part. On indique dans quelles conditions les liaisons sont etanches et quelles sont leurs resistances mecaniques et aux chocs thermiques. On indique, dans ce meme chapitre, une methode pour l'obtention de fenetres en beryllium soudees sur un support en acier inoxydable. (auteurs)

  1. Excess Entropy and Diffusivity

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Excess Entropy and Diffusivity. Excess entropy scaling of diffusivity (Rosenfeld,1977). Analogous relationships also exist for viscosity and thermal conductivity.

  2. 5-FU resistant EMT-like pancreatic cancer cells are hypersensitive to photochemical internalization of the novel endoglin-targeting immunotoxin CD105-saporin

    OpenAIRE

    Lund, Kaja; Olsen, Cathrine Elisabeth; Wong, Judith Jing Wen; Olsen, Petter Angell; Solberg, Nina Therese; Høgset, Anders; Krauss, Stefan; Selbo, Pål Kristian

    2017-01-01

    Background Development of resistance to 5-fluorouracil (5-FU) is a major problem in treatment of various cancers including pancreatic cancer. In this study, we reveal important resistance mechanisms and photochemical strategies to overcome 5-FU resistance in pancreatic adenocarcinoma. Methods 5-FU resistant (5-FUR), epithelial-to-mesenchymal-like sub-clones of the wild type pancreatic cancer cell line Panc03.27 were previously generated in our lab. We investigated the cytotoxic effect of the ...

  3. Reducing Resistance

    DEFF Research Database (Denmark)

    Lindell, Johanna

    care may influence decisions on antibiotic use. Based on video-and audio recordings of physician-patient consultations it is investigated how treatment recommendations are presented, can be changed, are forecast and explained, and finally, how they seemingly meet resistance and how this resistance......Antibiotic resistance is a growing public health problem both nationally and internationally, and efficient strategies are needed to reduce unnecessary use. This dissertation presents four research studies, which examine how communication between general practitioners and patients in Danish primary...... is responded to.The first study in the dissertation suggests that treatment recommendations on antibiotics are often done in a way that encourages patient acceptance. In extension of this, the second study of the dissertation examines a case, where acceptance of such a recommendation is changed into a shared...

  4. Internal pump

    International Nuclear Information System (INIS)

    Kushima, Jun; Hayashi, Youjiro; Ueda, Masayuki.

    1997-01-01

    The present invention relates to an internal pump. A water hole allowing communication between internal and external circumferences of a stretch tube is provided at the portion of the stretch tube corresponding to a position where an end face of a nozzle portion of a motor case and an end face of a diffuser are joined with each other so that hot filtered water inside a pressure container which has entered from where the end face of the nozzle portion of the motor case and the end face of the diffuser are joined with each other is combined with the purged water so that it can be sent back to the pressure container again. (author) figs

  5. Diffusion and reaction within porous packing media: a phenomenological model.

    Science.gov (United States)

    Jones, W L; Dockery, J D; Vogel, C R; Sturman, P J

    1993-04-25

    A phenomenological model has been developed to describe biomass distribution and substrate depletion in porous diatomaceous earth (DE) pellets colonized by Pseudomonas aeruginosa. The essential features of the model are diffusion, attachment and detachment to/from pore walls of the biomass, diffusion of substrate within the pellet, and external mass transfer of both substrate and biomass in the bulk fluid of a packed bed containing the pellets. A bench-scale reactor filled with DE pellets was inoculated with P. aeruginosa and operated in plug flow without recycle using a feed containing glucose as the limiting nutrient. Steady-state effluent glucose concentrations were measured at various residence times, and biomass distribution within the pellet was measured at the lowest residence time. In the model, microorganism/substrate kinetics and mass transfer characteristics were predicted from the literature. Only the attachment and detachment parameters were treated as unknowns, and were determined by fitting biomass distribution data within the pellets to the mathematical model. The rate-limiting step in substrate conversion was determined to be internal mass transfer resistance; external mass transfer resistance and microbial kinetic limitations were found to be nearly negligible. Only the outer 5% of the pellets contributed to substrate conversion.

  6. Diffuse lung disease: Pneumoconioses

    International Nuclear Information System (INIS)

    McLoud, T.C.

    1987-01-01

    This paper begins with a discussion of the 1980 International Labour Organization classification of the pneumoconioses. Emphasis is on the common pneumoconioses, that is, silicosis, coalworker's pneumoconiosis, and asbestos-related pleural and parenchymal disease. Examples of the five radiographic forms of silicosis-simple and complicated silicosis, Caplan syndrome, silicotuberculosis, and acute silicosis- are presented, and the differential diagnoses are discussed. Discussion of asbestos-related disease included pleural manifestations such as plaques, diffuse pleural thickening, and asbestos pleural effusion as well as asbestosis and malignancies associated with asbestos exposure, such as bronchogenic carcinoma and malignant mesothelioma. Although the standard radiographic findings are stressed, the use of CT in the diagnosis of pneumoconiosis and the staging of dust-related malignancies is also discussed

  7. Current limiting capability of diffused resistors

    International Nuclear Information System (INIS)

    Shedd, W.; Cappelli, J.

    1979-01-01

    An experimental evaluation of the current limiting capability of dielectrically isolated diffused resistors at transient ionizing dose rates up to 6*10 12 rads(Si)/sec is presented. Existing theoretical predictions of the transient response of diffused resistors are summarized and compared to the experimentally measured values. The test resistors used allow the effects of sheet resistance and geometry on the transient response to be determined. The experimental results show that typical dielectrically isolated diffused resistors maintain adequate current limiting capability for use in radiation hardened integrated circuits

  8. Diffusing diffusivity: Rotational diffusion in two and three dimensions

    Science.gov (United States)

    Jain, Rohit; Sebastian, K. L.

    2017-06-01

    We consider the problem of calculating the probability distribution function (pdf) of angular displacement for rotational diffusion in a crowded, rearranging medium. We use the diffusing diffusivity model and following our previous work on translational diffusion [R. Jain and K. L. Sebastian, J. Phys. Chem. B 120, 3988 (2016)], we show that the problem can be reduced to that of calculating the survival probability of a particle undergoing Brownian motion, in the presence of a sink. We use the approach to calculate the pdf for the rotational motion in two and three dimensions. We also propose new dimensionless, time dependent parameters, αr o t ,2 D and αr o t ,3 D, which can be used to analyze the experimental/simulation data to find the extent of deviation from the normal behavior, i.e., constant diffusivity, and obtain explicit analytical expressions for them, within our model.

  9. Diffusion in solids

    International Nuclear Information System (INIS)

    Tiwari, G.P.; Kale, G.B.; Patil, R.V.

    1999-01-01

    The article presents a brief survey of process of diffusion in solids. It is emphasised that the essence of diffusion is the mass transfer through the atomic jumps. To begin with formal equations for diffusion coefficient are presented. This is followed by discussions on mechanisms of diffusion. Except for solutes which form interstitial solid solution, diffusion in majority of cases is mediated through exchange of sites between an atom and its neighbouring vacancy. Various vacancy parameters such as activation volume, correlation factor, mass effect etc are discussed and their role in establishing the mode of diffusion is delineated. The contribution of dislocations and grain boundaries in diffusion process is brought out. The experimental determination of different types of diffusion coefficients are described. Finally, the pervasive nature of diffusion process in number of commercial processes is outlined to show the importance of diffusion studies in materials science and technology. (author)

  10. Diffusion archeology for diffusion progression history reconstruction

    OpenAIRE

    Sefer, Emre; Kingsford, Carl

    2015-01-01

    Diffusion through graphs can be used to model many real-world processes, such as the spread of diseases, social network memes, computer viruses, or water contaminants. Often, a real-world diffusion cannot be directly observed while it is occurring — perhaps it is not noticed until some time has passed, continuous monitoring is too costly, or privacy concerns limit data access. This leads to the need to reconstruct how the present state of the diffusion came to be from partial d...

  11. The effect of resistance level and stability demands on recruitment patterns and internal loading of spine in dynamic flexion and extension using a simple trunk model.

    Science.gov (United States)

    Zeinali-Davarani, Shahrokh; Shirazi-Adl, Aboulfazl; Dariush, Behzad; Hemami, Hooshang; Parnianpour, Mohamad

    2011-07-01

    The effects of external resistance on the recruitment of trunk muscles in sagittal movements and the coactivation mechanism to maintain spinal stability were investigated using a simple computational model of iso-resistive spine sagittal movements. Neural excitation of muscles was attained based on inverse dynamics approach along with a stability-based optimisation. The trunk flexion and extension movements between 60° flexion and the upright posture against various resistance levels were simulated. Incorporation of the stability constraint in the optimisation algorithm required higher antagonistic activities for all resistance levels mostly close to the upright position. Extension movements showed higher coactivation with higher resistance, whereas flexion movements demonstrated lower coactivation indicating a greater stability demand in backward extension movements against higher resistance at the neighbourhood of the upright posture. Optimal extension profiles based on minimum jerk, work and power had distinct kinematics profiles which led to recruitment patterns with different timing and amplitude of activation.

  12. Built-in hyperspectral camera for smartphone in visible, near-infrared and middle-infrared lights region (second report): sensitivity improvement of Fourier-spectroscopic imaging to detect diffuse reflection lights from internal human tissues for healthcare sensors

    Science.gov (United States)

    Kawashima, Natsumi; Hosono, Satsuki; Ishimaru, Ichiro

    2016-05-01

    We proposed the snapshot-type Fourier spectroscopic imaging for smartphone that was mentioned in 1st. report in this conference. For spectroscopic components analysis, such as non-invasive blood glucose sensors, the diffuse reflection lights from internal human skins are very weak for conventional hyperspectral cameras, such as AOTF (Acousto-Optic Tunable Filter) type. Furthermore, it is well known that the spectral absorption of mid-infrared lights or Raman spectroscopy especially in long wavelength region is effective to distinguish specific biomedical components quantitatively, such as glucose concentration. But the main issue was that photon energies of middle infrared lights and light intensities of Raman scattering are extremely weak. For improving sensitivity of our spectroscopic imager, the wide-field-stop & beam-expansion method was proposed. Our line spectroscopic imager introduced a single slit for field stop on the conjugate objective plane. Obviously to increase detected light intensities, the wider slit width of the field stop makes light intensities higher, regardless of deterioration of spatial resolutions. Because our method is based on wavefront-division interferometry, it becomes problems that the wider width of single slit makes the diffraction angle narrower. This means that the narrower diameter of collimated objective beams deteriorates visibilities of interferograms. By installing the relative inclined phaseshifter onto optical Fourier transform plane of infinity corrected optical systems, the collimated half flux of objective beams derived from single-bright points on objective surface penetrate through the wedge prism and the cuboid glass respectively. These two beams interfere each other and form the infererogram as spatial fringe patterns. Thus, we installed concave-cylindrical lens between the wider slit and objective lens as a beam expander. We successfully obtained the spectroscopic characters of hemoglobin from reflected lights from

  13. Standardized uptake value for (18)F-fluorodeoxyglucose is correlated with a high International Prognostic Index and the presence of extranodal involvement in patients with diffuse large B-cell lymphoma.

    Science.gov (United States)

    Akkas, B E; Vural, G U

    2014-01-01

    The aim of this study was to evaluate whether the maximum standardized uptake value (SUVmax) of (18)F-fluorodeoxyglucose (FDG) correlates with the International Prognostic Index (IPI) and the presence of extranodal involvement in patients with Diffuse Large B-Cell Lymphoma (DLBCL). 77 patients (age: 57.2±18.5, 40F, 37M) with DLBCL who underwent FDG PET/CT for initial staging were included. SUVmax of the predominant lesions were compared to Ann Arbor stage, IPI scores, the presence of extranodal involvement and the number extranodal sites. PET/CT detected nodal (n:25) and extranodal involvement (n:52) in all the patients. In 27 patients, extranodal disease could only be detected by PET. SUVmax of the predominant lesion in patients with extranodal disease was significantly higher than that of the patients who had only nodal disease (25±12 vs. 15.3±10 respectively, p=0.001). SUVmax significantly correlated with IPI scores; the average SUVmax was significantly correlated with the IPI: Mean SUVmax of the predominant lesion was 13.9±9.5 in patients with low risk (IPI=0-1), 14.2±8.8 in low-intermediate risk group (IPI=2) whereas 26.6±9.5 in high-intermediate risk group (IPI=3) and 25±13.6 in high risk group patients (IPI=4-5) (p=0.002). SUVmax was not correlated with clinical stage, the number of extranodal sites and serum LDH levels. FDG uptake correlates with IPI and the presence of extranodal involvement in DLBCL. PET is a powerful method to detect extranodal disease in DLBCL. The correlation of SUVmax with these prognostic factors may highlight the importance of pretreatment FDG uptake as a metabolic marker of poor prognosis for patients with DLBCL. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

  14. Can Apparent Diffusion Coefficient Values Assist PI-RADS Version 2 DWI Scoring? A Correlation Study Using the PI-RADSv2 and International Society of Urological Pathology Systems.

    Science.gov (United States)

    Gaur, Sonia; Harmon, Stephanie; Rosenblum, Lauren; Greer, Matthew D; Mehralivand, Sherif; Coskun, Mehmet; Merino, Maria J; Wood, Bradford J; Shih, Joanna H; Pinto, Peter A; Choyke, Peter L; Turkbey, Baris

    2018-05-07

    The purposes of this study were to assess correlation of apparent diffusion coefficient (ADC) and normalized ADC (ratio of tumor to nontumor tissue) with the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) and updated International Society of Urological Pathology (ISUP) categories and to determine how to optimally use ADC metrics for objective assistance in categorizing lesions within PI-RADSv2 guidelines. In this retrospective study, 100 patients (median age, 62 years; range, 44-75 years; prostate-specific antigen level, 7.18 ng/mL; range, 1.70-84.56 ng/mL) underwent 3-T multiparametric MRI of the prostate with an endorectal coil. Mean ADC was extracted from ROIs based on subsequent prostatectomy specimens. Histopathologic analysis revealed 172 lesions (113 peripheral, 59 transition zone). Two radiologists blinded to histopathologic outcome assigned PI-RADSv2 categories. Kendall tau was used to correlate ADC metrics with PI-RADSv2 and ISUP categories. ROC curves were used to assess the utility of ADC metrics in differentiating each reader's PI-RADSv2 DWI category 4 or 5 assessment in the whole prostate and by zone. ADC metrics negatively correlated with ISUP category in the whole prostate (ADC, τ = -0.21, p = 0.0002; normalized ADC, τ = -0.21, p = 0.0001). Moderate negative correlation was found in expert PI-RADSv2 DWI categories (ADC, τ = -0.34; normalized ADC, τ = -0.31; each p correlate with PI-RADSv2 and ISUP categories and can serve as quantitative metrics to assist with assigning PI-RADSv2 DWI category 4 or 5.

  15. Multicomponent diffusion in two-temperature magnetohydrodynamics

    International Nuclear Information System (INIS)

    Ramshaw, J.D.; Chang, C.H.

    1996-01-01

    A recent hydrodynamic theory of multicomponent diffusion in multitemperature gas mixtures [J. D. Ramshaw, J. Non-Equilib. Thermodyn. 18, 121 (1993)] is generalized to include the velocity-dependent Lorentz force on charged species in a magnetic field B. This generalization is used to extend a previous treatment of ambipolar diffusion in two-temperature multicomponent plasmas [J. D. Ramshaw and C. H. Chang, Plasma Chem. Plasma Process. 13, 489 (1993)] to situations in which B and the electrical current density are nonzero. General expressions are thereby derived for the species diffusion fluxes, including thermal diffusion, in both single- and two-temperature multicomponent magnetohydrodynamics (MHD). It is shown that the usual zero-field form of the Stefan-Maxwell equations can be preserved in the presence of B by introducing generalized binary diffusion tensors dependent on B. A self-consistent effective binary diffusion approximation is presented that provides explicit approximate expressions for the diffusion fluxes. Simplifications due to the small electron mass are exploited to obtain an ideal MHD description in which the electron diffusion coefficients drop out, resistive effects vanish, and the electric field reduces to a particularly simple form. This description should be well suited for numerical calculations. copyright 1996 The American Physical Society

  16. Spin-diffusions and diffusive molecular dynamics

    Science.gov (United States)

    Farmer, Brittan; Luskin, Mitchell; Plecháč, Petr; Simpson, Gideon

    2017-12-01

    Metastable configurations in condensed matter typically fluctuate about local energy minima at the femtosecond time scale before transitioning between local minima after nanoseconds or microseconds. This vast scale separation limits the applicability of classical molecular dynamics (MD) methods and has spurned the development of a host of approximate algorithms. One recently proposed method is diffusive MD which aims at integrating a system of ordinary differential equations describing the likelihood of occupancy by one of two species, in the case of a binary alloy, while quasistatically evolving the locations of the atoms. While diffusive MD has shown itself to be efficient and provide agreement with observations, it is fundamentally a model, with unclear connections to classical MD. In this work, we formulate a spin-diffusion stochastic process and show how it can be connected to diffusive MD. The spin-diffusion model couples a classical overdamped Langevin equation to a kinetic Monte Carlo model for exchange amongst the species of a binary alloy. Under suitable assumptions and approximations, spin-diffusion can be shown to lead to diffusive MD type models. The key assumptions and approximations include a well-defined time scale separation, a choice of spin-exchange rates, a low temperature approximation, and a mean field type approximation. We derive several models from different assumptions and show their relationship to diffusive MD. Differences and similarities amongst the models are explored in a simple test problem.

  17. PREVALENCE AND ANTIBIOTIC RESISTANCE OF ...

    African Journals Online (AJOL)

    9 mars 2015 ... strategy to prevent the spread of this resistance. Keywords: Staphylococci; Staphylococcus aureus; Oxacillin; Antibiotic resistance; Disc diffusion. Author Correspondence, e-mail: mn.boukhatem@yahoo.fr. ICID: 1142924. Journal of Fundamental and Applied Sciences. ISSN 1112-9867. Available online at.

  18. Diffusion processes in β-Zr(Al) phase: a thermodynamic approach

    Indian Academy of Sciences (India)

    Unknown

    Keywords. Interdiffusion; diffusion coefficient; activation energy; zirconium; aluminium. 1. Introduction ... red mechanical properties and good corrosion resistance, which make them ..... (14) and imposing the above mentioned conditions, the.

  19. Diffusion in reactor materials

    International Nuclear Information System (INIS)

    Fedorov, G.B.; Smirnov, E.A.

    1984-01-01

    The monograph contains a brief description of the principles underlying the theory of diffusion, as well as modern methods of studying diffusion. Data on self-diffusion and diffusion of impurities in a nuclear fuel and fissionable materials (uranium, plutonium, thorium, zirconium, titanium, hafnium, niobium, molybdenum, tungsten, beryllium, etc.) is presented. Anomalous diffusion, diffusion of components, and interdiffusion in binary and ternary alloys were examined. The monograph presents the most recent reference material on diffusion. It is intended for a wide range of researchers working in the field of diffusion in metals and alloys and attempting to discover new materials for application in nuclear engineering. It will also be useful for teachers, research scholars and students of physical metallurgy

  20. Plasma internal inductance dynamics in a tokamak

    International Nuclear Information System (INIS)

    Romero, J.A.

    2010-01-01

    A lumped parameter model for tokamak plasma current and inductance time evolution as a function of plasma resistance, non-inductive current drive sources and boundary voltage or poloidal field coil current drive is presented. The model includes a novel formulation leading to exact equations for internal inductance and plasma current dynamics. Having in mind its application in a tokamak inductive control system, the model is expressed in state space form, the preferred choice for the design of control systems using modern control systems theory. The choice of system states allows many interesting physical quantities such as plasma current, inductance, magnetic energy, and resistive and inductive fluxes be made available as output equations. The model is derived from energy conservation theorem, and flux balance theorems, together with a first order approximation for flux diffusion dynamics. The validity of this approximation has been checked using experimental data from JET showing an excellent agreement.

  1. Diffusion in flowing gas

    International Nuclear Information System (INIS)

    Reus, K.W.

    1979-01-01

    This thesis is concerned with the back-diffusion method of calculating the mutual diffusion coefficient of two gases. The applicability of this method for measuring diffusion coefficients at temperatures up to 1300 K is considered. A further aim of the work was to make a contribution to the description of the interatomic potential energy of noble gases at higher energies as a function of the internuclear distance. This was achieved with the measured diffusion coefficients, especially with those for high temperatures. (Auth.)

  2. Diffusion Under Geometrical Constraint

    OpenAIRE

    Ogawa, Naohisa

    2014-01-01

    Here we discus the diffusion of particles in a curved tube. This kind of transport phenomenon is observed in biological cells and porous media. To solve such a problem, we discuss the three dimensional diffusion equation with a confining wall forming a thinner tube. We find that the curvature appears in a effective diffusion coefficient for such a quasi-one-dimensional system. As an application to higher dimensional case, we discuss the diffusion in a curved surface with ...

  3. Purulent meningitis with unusual diffusion-weighted MRI findings

    International Nuclear Information System (INIS)

    Abe, M.; Takayama, Y.; Yamashita, H.; Noguchi, M.; Sagoh, T.

    2002-01-01

    We describe unusual findings obtained by diffusion-weighted magnetic resonance imaging (MRI) in a patient with acute purulent meningitis caused by penicillin-resistant Streptococcus pneumoniae. Along cerebral convexities and the Sylvian fissure, multiple small intense lesions showed high signal intensity in these sequences. This may be the first report of diffusion-weighted in purulent meningitis

  4. Diffuse ceiling ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen

    Diffuse ceiling ventilation is an innovative ventilation concept where the suspended ceiling serves as air diffuser to supply fresh air into the room. Compared with conventional ventilation systems, diffuse ceiling ventilation can significantly reduce or even eliminate draught risk due to the low...

  5. Diffused zircaloy 2/stainless steel junctions

    International Nuclear Information System (INIS)

    Jacques, F.

    1964-01-01

    The diffusion permits to realize joints between two different materials, in fact of the formation of a liquid phase at the contact face. The study of the tensile properties allowed the determination of the ideal conditions for the diffusion treatment which are, within 2 and 3 minutes for a temperature within 1020 C and 1030 C. The characteristics of the so obtained joints were, studied: mechanical properties, tightness, resistance to thermal cycling. Analysis of the thermal stress, owing to the differential dilatation of the two materials mode the object of a particular study. The investigation on the diffusion zone, includes specially, an analysis of the constituents distribution formed during the diffusion treatment. (author) [fr

  6. A transient divided-bar method for simultaneous measurements of thermal conductivity and thermal diffusivity

    DEFF Research Database (Denmark)

    Bording, Thue Sylvester; Nielsen, Søren Bom; Balling, Niels

    2016-01-01

    and volumetric heat capacity, and thereby also thermal diffusivity, are measured simultaneously. As the density of samples is easily determined independently, specific heat capacity may also be determined. Finite element formulation provides a flexible forward solution for heat transfer across the bar...... and thermal properties are estimated by inverse Monte Carlo modelling. This methodology enables a proper quantification of experimental uncertainties on measured thermal properties. The developed methodology was applied to laboratory measurements of various materials, including a standard ceramic material......-3 %, and for diffusivity uncertainty may be reduced to about 3-5 %. The main uncertainty originates from the presence of thermal contact resistance associated with the internal interfaces of the bar. They are not resolved during inversion, and it is highly important that they are minimized by careful sample preparation....

  7. Resistance to change

    NARCIS (Netherlands)

    Dow, J.; Perotti, E.

    2009-01-01

    Established firms often fail to maintain leadership following disruptive market shifts. We argue that such firms are more prone to internal resistance. A radical adjustment of assets affects the distribution of employee rents, creating winners and losers. Losers resist large changes when strong

  8. Resistance to change

    NARCIS (Netherlands)

    Dow, J.; Perotti, E.

    2013-01-01

    Established firms often fail to maintain leadership following disrup tive market shifts. We argue that such firms are more prone to internal resistance. A radical adjustment of assets affects the distribution of employee rents, creating winners and losers. Losers resist large changes when strong

  9. Thermal diffusion (1963); Diffusion thermique (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-07-01

    This report brings together the essential principles of thermal diffusion in the liquid and gaseous phases. The macroscopic and molecular aspects of the thermal diffusion constant are reviewed, as well as the various measurement method; the most important developments however concern the operation of the CLUSIUS and DICKEL thermo-gravitational column and its applications. (author) [French] Ce rapport rassemble les principes essentiels de la diffusion thermique en phase liquide et en phase gazeuse. Les aspects macroscopique et moleculaire de la constante de diffusion thermique sont passes en revue ainsi que ses differentes methodes de mesure; mais les developpements les plus importants concernent le fonctionnement de ls colonne thermogravitationnelle de CLUSIUS et DICKEL et ses applications. (auteur)

  10. Fractional diffusion equations and anomalous diffusion

    CERN Document Server

    Evangelista, Luiz Roberto

    2018-01-01

    Anomalous diffusion has been detected in a wide variety of scenarios, from fractal media, systems with memory, transport processes in porous media, to fluctuations of financial markets, tumour growth, and complex fluids. Providing a contemporary treatment of this process, this book examines the recent literature on anomalous diffusion and covers a rich class of problems in which surface effects are important, offering detailed mathematical tools of usual and fractional calculus for a wide audience of scientists and graduate students in physics, mathematics, chemistry and engineering. Including the basic mathematical tools needed to understand the rules for operating with the fractional derivatives and fractional differential equations, this self-contained text presents the possibility of using fractional diffusion equations with anomalous diffusion phenomena to propose powerful mathematical models for a large variety of fundamental and practical problems in a fast-growing field of research.

  11. Diffusion in molybdenum disilicide

    International Nuclear Information System (INIS)

    Salamon, M.; Mehrer, H.

    2005-01-01

    The diffusion behaviour of the high-temperature material molybdenum disilicide (MoSi 2 ) was completely unknown until recently. In this paper we present studies of Mo self-diffusion and compare our present results with our already published studies of Si and Ge diffusion in MoSi 2 . Self-diffusion of molybdenum in monocrystalline MoSi 2 was studied by the radiotracer technique using the radioisotope 99 Mo. Deposition of the radiotracer and serial sectioning after the diffusion anneals to determine the concentration-depth profiles was performed using a sputtering device. Diffusion of Mo is a very slow process. In the entire temperature region investigated (1437 to 2173 K), the 99 Mo diffusivities in both principal directions of the tetragonal MoSi 2 crystals obey Arrhenius laws, where the diffusion perpendicular to the tetragonal axis is faster by two to three orders of magnitude than parallel to it. The activation enthalpies for diffusion perpendicular and parallel to the tetragonal axis are Q perpendicular to = 468 kJ mol -1 (4.85 eV) and Q parallel = 586 kJ mol -1 (6.07 eV), respectively. Diffusion of Si and its homologous element Ge is fast and is mediated by thermal vacancies of the Si sublattice of MoSi 2 . The diffusion of Mo is by several orders of magnitude slower than the diffusion of Si and Ge. This large difference suggests that Si and Mo diffusion are decoupled and that the diffusion of Mo likely takes place via vacancies on the Mo sublattice. (orig.)

  12. A study of the diffusion mechanisms in amorphous metallic alloys: diffusion and diffusion under high pressure in an amorphous NiZr alloy

    International Nuclear Information System (INIS)

    Grandjean, A.

    1996-01-01

    The aim of this work is a better understanding of the diffusion mechanism in amorphous metallic alloys. Then interdiffusion and hafnium diffusion in amorphous NiZr alloy have been studied. Samples used are made by sputtering co-deposition under vacuum and are well relaxed before the diffusion measurements. The time evolution of resistivity during annealing due to the decay of a composition modulated film has been measured and from this change in resistivity interdiffusion coefficients have been determined. Dependence of Hf diffusion on temperature and pressure has been studied using (SIMS). In this two cases, the diffusion process obeys an Arrhenius law and gives an activation energy of 1.33 eV for interdiffusion, and 0.76 eV for Hf diffusion. An effect of pressure on Hf diffusion has been found leading to an activation volume of 8.5 angstrom 3 . Thanks to these results, two approaches of the diffusion mechanisms in these systems have been proposed. The first comes from a comparison with the diffusion mechanisms in crystalline metals, that is to say by point defects. The second is an hypothesis of collective motions in these non crystalline alloys. (author)

  13. Durability predictions from rate of diffusion testing of normal portland cement, fly ash, and slag concrete

    International Nuclear Information System (INIS)

    Philipose, K.E.

    1991-09-01

    A waste repository for the belowground disposal of low-level radioactive waste, labelled IRUS (Intrusion Resistant Underground Structure), is planned at the Chalk River Laboratories. It relies greatly on the durability of concrete for a minimum of 500 years of service life. A research program based on laboratory testing to design a durable concrete and predict its useful engineered service life is in progress. The durability of concrete depends on its resistance to deterioration from both internal and external causes. Since the rate of degradation depends to a major extent on the rate of ingress of aggressive ions into concrete, laboratory testing is in progress to establish the diffusion rates of chlorides and sulphate ions. A total of 1000 concrete specimens and 500 paste specimens are being exposed at 22 degrees and 45 degrees C to twenty-five different combinations of corrosive agents, including CO 2 . Procedures to measure the ionic penetration profile and to determine the factors controlling diffusion of ions in the various concretes have been developed. The paper presents the initial results from the research program and the longevity predictions to qualify concretes for the IRUS waste repository, based on 16 months of diffusion testing on laboratory specimens

  14. Development of Multiple Antibiotic Resistance in Bacillus subtilis Cells Exposed to Microgravity: the BRIC-18 Experiment to the International Space Station

    Science.gov (United States)

    Fajardo-Cavazos, Patricia; Moeller, Ralf; Nicholson, Wayne; Narvel, Raed

    Increased pathogenicity of opportunistic bacteria during long-term spaceflight is considered an astronaut risk. Because only a limited pharmacy can be carried on long-duration missions, the development of resistance to multiple antibiotics is a concern for mission planning. In support of the BRIC-18 experiment to the ISS, we have performed ground-based experiments to address the question whether simulated microgravity affects the frequency of resistance to the model antibiotics rifampicin (RFM) and trimethoprim (TMP). In these experiments, the model bacteria Bacillus subtilis and Staphylococcus epidermidis were cultivated for 6 days at ISS ambient temperature in 10-ml High Aspect Ratio Vessels (HARVs) on two 4-place clinostats (Synthecon) oriented either vertically (V) or horizontally (H). Cells were harvested, enumerated and plated onto medium containing RFM (5 micrograms/ml). The frequency of mutation to RFM resistance was calculated, and RFM-resistant mutants were plated onto medium containing the second antibiotic, TMP (5 micrograms/ml) to determine the frequency of mutation to double (RFM+TMP) resistance. After 6 days of cultivation, V-cultures showed higher cell densities and than H-cultures for both bacteria. However, only in B. subtilis did V-cultures show higher frequencies of mutation to RFM resistance than H-cultures. Launch of BRIC-18 to the ISS is currently scheduled for March 16, 2014 and return 30 days later. Results from both the spaceflight and ground control experiments will be presented. Supported by NASA-SAIP fellowship to R.N. and NASA grant (NNX12AN70G) to P.F.-C., R.M., and W.L.N.

  15. Metric diffusion along foliations

    CERN Document Server

    Walczak, Szymon M

    2017-01-01

    Up-to-date research in metric diffusion along compact foliations is presented in this book. Beginning with fundamentals from the optimal transportation theory and the theory of foliations; this book moves on to cover Wasserstein distance, Kantorovich Duality Theorem, and the metrization of the weak topology by the Wasserstein distance. Metric diffusion is defined, the topology of the metric space is studied and the limits of diffused metrics along compact foliations are discussed. Essentials on foliations, holonomy, heat diffusion, and compact foliations are detailed and vital technical lemmas are proved to aide understanding. Graduate students and researchers in geometry, topology and dynamics of foliations and laminations will find this supplement useful as it presents facts about the metric diffusion along non-compact foliation and provides a full description of the limit for metrics diffused along foliation with at least one compact leaf on the two dimensions.

  16. Measurement of chemical diffusion coefficients in liquid binary alloys

    International Nuclear Information System (INIS)

    Keita, M.; Steinemann, S.; Kuenzi, H.U.

    1976-01-01

    New measurements of the chemical diffusion coefficient in liquid binary alloys are presented. The wellknown geometry of the 'capillary-reservoir' is used and the concentration is obtained from a resistivity measurement. The method allows to follow continuously the diffusion process in the liquid state. A precision of at least 10% in the diffusion coefficient is obtained with a reproductibility better than 5%. The systems Hg-In, Al-Sn, Al-Si have been studied. Diffusion coefficients are obtained as a function of temperature, concentration, and geometrical factors related to the capillary (diameter, relative orientation of density gradient and gravity). (orig.) [de

  17. The passive diffusion of Leptospira interrogans

    International Nuclear Information System (INIS)

    Koens, Lyndon; Lauga, Eric

    2014-01-01

    Motivated by recent experimental measurements, the passive diffusion of the bacterium Leptospira interrogans is investigated theoretically. By approximating the cell shape as a straight helix and using the slender-body-theory approximation of Stokesian hydrodynamics, the resistance matrix of Leptospira is first determined numerically. The passive diffusion of the helical cell is then obtained computationally using a Langevin formulation which is sampled in time in a manner consistent with the experimental procedure. Our results are in excellent quantitative agreement with the experimental results with no adjustable parameters. (paper)

  18. The passive diffusion of Leptospira interrogans

    Science.gov (United States)

    Koens, Lyndon; Lauga, Eric

    2014-12-01

    Motivated by recent experimental measurements, the passive diffusion of the bacterium Leptospira interrogans is investigated theoretically. By approximating the cell shape as a straight helix and using the slender-body-theory approximation of Stokesian hydrodynamics, the resistance matrix of Leptospira is first determined numerically. The passive diffusion of the helical cell is then obtained computationally using a Langevin formulation which is sampled in time in a manner consistent with the experimental procedure. Our results are in excellent quantitative agreement with the experimental results with no adjustable parameters.

  19. Correlated diffusion imaging

    International Nuclear Information System (INIS)

    Wong, Alexander; Glaister, Jeffrey; Cameron, Andrew; Haider, Masoom

    2013-01-01

    Prostate cancer is one of the leading causes of cancer death in the male population. Fortunately, the prognosis is excellent if detected at an early stage. Hence, the detection and localization of prostate cancer is crucial for diagnosis, as well as treatment via targeted focal therapy. New imaging techniques can potentially be invaluable tools for improving prostate cancer detection and localization. In this study, we introduce a new form of diffusion magnetic resonance imaging called correlated diffusion imaging, where the tissue being imaged is characterized by the joint correlation of diffusion signal attenuation across multiple gradient pulse strengths and timings. By taking into account signal attenuation at different water diffusion motion sensitivities, correlated diffusion imaging can provide improved delineation between cancerous tissue and healthy tissue when compared to existing diffusion imaging modalities. Quantitative evaluation using receiver operating characteristic (ROC) curve analysis, tissue class separability analysis, and visual assessment by an expert radiologist were performed to study correlated diffusion imaging for the task of prostate cancer diagnosis. These results are compared with that obtained using T2-weighted imaging and standard diffusion imaging (via the apparent diffusion coefficient (ADC)). Experimental results suggest that correlated diffusion imaging provide improved delineation between healthy and cancerous tissue and may have potential as a diagnostic tool for cancer detection and localization in the prostate gland. A new form of diffusion magnetic resonance imaging called correlated diffusion imaging (CDI) was developed for the purpose of aiding radiologists in cancer detection and localization in the prostate gland. Preliminary results show CDI shows considerable promise as a diagnostic aid for radiologists in the detection and localization of prostate cancer

  20. Gaseous diffusion system

    International Nuclear Information System (INIS)

    Garrett, G.A.; Shacter, J.

    1978-01-01

    A gaseous diffusion system is described comprising a plurality of diffusers connected in cascade to form a series of stages, each of the diffusers having a porous partition dividing it into a high pressure chamber and a low pressure chamber, and means for combining a portion of the enriched gas from a succeeding stage with a portion of the enriched gas from the low pressure chamber of each stage and feeding it into one extremity of the high pressure chamber thereof

  1. Traffic accidents and road surface skidding resistance : paper presented to the Second Internation Skid Prevention Conference, Columbus, Ohio, May 2-6, 1977.

    NARCIS (Netherlands)

    Schlösser, L.H.M.

    1999-01-01

    In this research a statistical relation was sought between the skidding resistance of road surfaces and the relative road risks. In the concept of accident quotient the number of accidents that occurs on a certain section of road within a certain period of time is related to the total number of

  2. Inpainting using airy diffusion

    Science.gov (United States)

    Lorduy Hernandez, Sara

    2015-09-01

    One inpainting procedure based on Airy diffusion is proposed, implemented via Maple and applied to some digital images. Airy diffusion is a partial differential equation with spatial derivatives of third order in contrast with the usual diffusion with spatial derivatives of second order. Airy diffusion generates the Airy semigroup in terms of the Airy functions which can be rewritten in terms of Bessel functions. The Airy diffusion can be used to smooth an image with the corresponding noise elimination via convolution. Also the Airy diffusion can be used to erase objects from an image. We build an algorithm using the Maple package ImageTools and such algorithm is tested using some images. Our results using Airy diffusion are compared with the similar results using standard diffusion. We observe that Airy diffusion generates powerful filters for image processing which could be incorporated in the usual packages for image processing such as ImageJ and Photoshop. Also is interesting to consider the possibility to incorporate the Airy filters as applications for smartphones and smart-glasses.

  3. Diffusion in compacted betonite

    International Nuclear Information System (INIS)

    Muurinen, A.; Rantanen, J.

    1985-01-01

    The objective of this report is to collect the literature bearing on the diffusion in compacted betonite, which has been suggested as possible buffer material for the disposal of spent fuel. Diffusion in a porous, water-saturated material is usually described as diffusion in the pore-water where sorption on the solid matter can delay the migration in the instationary state. There are also models which take into consideration that the sorbed molecules can also move while being sorbed. Diffusion experiments in compacted bentonite have been reported by many authors. Gases, anions, cations and actinides have been used as diffusing molecules. The report collects the results and the information on the measurement methods. On the basis of the results can be concluded that different particles possibly follow different diffusion mechanisms. The parameters which affect the diffusion seem to be for example the size, the electric charge and the sorption properties of the diffusing molecule. The report also suggest the parameters to be used in the diffusion calculation of the safety analyses of spent fuel disposal. (author)

  4. SNAP - a three dimensional neutron diffusion code

    International Nuclear Information System (INIS)

    McCallien, C.W.J.

    1993-02-01

    This report describes a one- two- three-dimensional multi-group diffusion code, SNAP, which is primarily intended for neutron diffusion calculations but can also carry out gamma calculations if the diffusion approximation is accurate enough. It is suitable for fast and thermal reactor core calculations and for shield calculations. SNAP can solve the multi-group neutron diffusion equations using finite difference methods. The one-dimensional slab, cylindrical and spherical geometries and the two-dimensional case are all treated as simple special cases of three-dimensional geometries. Numerous reflective and periodic symmetry options are available and may be used to reduce the number of mesh points necessary to represent the system. Extrapolation lengths can be specified at internal and external boundaries. (Author)

  5. MDM2 phenotypic and genotypic profiling, respective to TP53 genetic status, in diffuse large B-cell lymphoma patients treated with rituximab-CHOP immunochemotherapy: a report from the International DLBCL Rituximab-CHOP Consortium Program

    NARCIS (Netherlands)

    Xu-Monette, Z.Y.; Moller, M.B.; Tzankov, A.; Montes-Moreno, S.; Hu, W.; Manyam, G.C.; Kristensen, L.; Fan, L.; Visco, C.; Dybkaer, K.; Chiu, A.; Tam, W.; Zu, Y.; Bhagat, G.; Richards, K.L.; Hsi, E.D.; Choi, W.W.; Krieken, J.H.J.M. van; Huang, Q.; Huh, J.; Ai, W.; Ponzoni, M.; Ferreri, A.J.; Wu, L.; Zhao, X.; Bueso-Ramos, C.E.; Wang, S.A.; Go, R.S.; Li, Y.; Winter, J.N.; Piris, M.A.; Medeiros, L.J.; Young, K.H.

    2013-01-01

    MDM2 is a key negative regulator of the tumor suppressor p53, however, the prognostic significance of MDM2 overexpression in diffuse large B-cell lymphoma (DLBCL) has not been defined convincingly. In a p53 genetically-defined large cohort of de novo DLBCL patients treated with rituximab,

  6. Patients with diffuse large B-cell lymphoma of germinal center origin with BCL2 translocations have poor outcome, irrespective of MYC status: a report from an International DLBCL rituximab-CHOP Consortium Program Study.

    NARCIS (Netherlands)

    Visco, C.; Tzankov, A.; Xu-Monette, Z.Y.; Miranda, R.N.; Tai, Y.C.; Li, Y.; Liu, W.M.; d'Amore, E.S.; Li, Y.O.; Montes-Moreno, S.; Dybkaer, K.; Chiu, A.; Orazi, A.; Zu, Y.; Bhagat, G.; Wang, H.Y.; Dunphy, C.H.; His, E.D.; Zhao, X.F.; Choi, W.W.; Krieken, J.H.J.M. van; Huang, Q.; Ai, W.; O'Neill, S.; Ponzoni, M.; Ferreri, A.J.; Kahl, B.S.; Winter, J.N.; Go, R.S.; Dirnhofer, S.; Piris, M.A.; Moller, M.B.; Wu, L.; Medeiros, L.J.; Young, K.H.

    2013-01-01

    Diffuse large B-cell lymphoma can be classified by gene expression profiling into germinal center and activated B-cell subtypes with different prognoses after rituximab-CHOP. The importance of previously recognized prognostic markers, such as Bcl-2 protein expression and BCL2 gene abnormalities, has

  7. Uranium enrichment export control guide: Gaseous diffusion

    Energy Technology Data Exchange (ETDEWEB)

    1989-09-01

    This document was prepared to serve as a guide for export control officials in their interpretation, understanding, and implementation of export laws that relate to the Zangger International Trigger List for gaseous diffusion uranium enrichment process components, equipment, and materials. Particular emphasis is focused on items that are especially designed or prepared since export controls are required for these by States that are party to the International Nuclear Nonproliferation Treaty.

  8. Discrimination of thermal diffusivity

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kappers, A.M.L.

    2009-01-01

    Materials such as wood or metal which are at equal temperatures are perceived to be of different ‘coldness’ due to differences in thermal properties, such as the thermal diffusivity. The thermal diffusivity of a material is a parameter that controls the rate with which heat is extracted from the

  9. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Fogh Olsen, Ole; Sporring, Jon

    2007-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  10. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Olsen, Ole Fogh; Sporring, Jon

    2006-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  11. Adaptation and Cultural Diffusion.

    Science.gov (United States)

    Ormrod, Richard K.

    1992-01-01

    Explores the role of adaptation in cultural diffusion. Explains that adaptation theory recognizes the lack of independence between innovations and their environmental settings. Discusses testing and selection, modification, motivation, and cognition. Suggests that adaptation effects are pervasive in cultural diffusion but require a broader, more…

  12. Modelling of Innovation Diffusion

    Directory of Open Access Journals (Sweden)

    Arkadiusz Kijek

    2010-01-01

    Full Text Available Since the publication of the Bass model in 1969, research on the modelling of the diffusion of innovation resulted in a vast body of scientific literature consisting of articles, books, and studies of real-world applications of this model. The main objective of the diffusion model is to describe a pattern of spread of innovation among potential adopters in terms of a mathematical function of time. This paper assesses the state-of-the-art in mathematical models of innovation diffusion and procedures for estimating their parameters. Moreover, theoretical issues related to the models presented are supplemented with empirical research. The purpose of the research is to explore the extent to which the diffusion of broadband Internet users in 29 OECD countries can be adequately described by three diffusion models, i.e. the Bass model, logistic model and dynamic model. The results of this research are ambiguous and do not indicate which model best describes the diffusion pattern of broadband Internet users but in terms of the results presented, in most cases the dynamic model is inappropriate for describing the diffusion pattern. Issues related to the further development of innovation diffusion models are discussed and some recommendations are given. (original abstract

  13. Thermal diffusion (1963)

    International Nuclear Information System (INIS)

    Lemarechal, A.

    1963-01-01

    This report brings together the essential principles of thermal diffusion in the liquid and gaseous phases. The macroscopic and molecular aspects of the thermal diffusion constant are reviewed, as well as the various measurement method; the most important developments however concern the operation of the CLUSIUS and DICKEL thermo-gravitational column and its applications. (author) [fr

  14. Diffusion of Botulinum Toxins

    Directory of Open Access Journals (Sweden)

    Matthew A. Brodsky

    2012-08-01

    Full Text Available Background: It is generally agreed that diffusion of botulinum toxin occurs, but the extent of the spread and its clinical importance are disputed. Many factors have been suggested to play a role but which have the most clinical relevance is a subject of much discussion.Methods: This review discusses the variables affecting diffusion, including protein composition and molecular size as well as injection factors (e.g., volume, dose, injection method. It also discusses data on diffusion from comparative studies in animal models and human clinical trials that illustrate differences between the available botulinum toxin products (onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and rimabotulinumtoxinB.Results: Neither molecular weight nor the presence of complexing proteins appears to affect diffusion; however, injection volume, concentration, and dose all play roles and are modifiable. Both animal and human studies show that botulinum toxin products are not interchangeable, and that some products are associated with greater diffusion and higher rates of diffusion-related adverse events than others.Discussion: Each of the botulinum toxins is a unique pharmacologic entity. A working knowledge of the different serotypes is essential to avoid unwanted diffusion-related adverse events. In addition, clinicians should be aware that the factors influencing diffusion may range from properties intrinsic to the drug to accurate muscle selection as well as dilution, volume, and dose injected.

  15. Diffusion in Coulomb crystals.

    Science.gov (United States)

    Hughto, J; Schneider, A S; Horowitz, C J; Berry, D K

    2011-07-01

    Diffusion in Coulomb crystals can be important for the structure of neutron star crusts. We determine diffusion constants D from molecular dynamics simulations. We find that D for Coulomb crystals with relatively soft-core 1/r interactions may be larger than D for Lennard-Jones or other solids with harder-core interactions. Diffusion, for simulations of nearly perfect body-centered-cubic lattices, involves the exchange of ions in ringlike configurations. Here ions "hop" in unison without the formation of long lived vacancies. Diffusion, for imperfect crystals, involves the motion of defects. Finally, we find that diffusion, for an amorphous system rapidly quenched from Coulomb parameter Γ=175 to Coulomb parameters up to Γ=1750, is fast enough that the system starts to crystalize during long simulation runs. These results strongly suggest that Coulomb solids in cold white dwarf stars, and the crust of neutron stars, will be crystalline and not amorphous.

  16. Atomic diffusion in stars

    CERN Document Server

    Michaud, Georges; Richer, Jacques

    2015-01-01

    This book gives an overview of atomic diffusion, a fundamental physical process, as applied to all types of stars, from the main sequence to neutron stars. The superficial abundances of stars as well as their evolution can be significantly affected. The authors show where atomic diffusion plays an essential role and how it can be implemented in modelling.  In Part I, the authors describe the tools that are required to include atomic diffusion in models of stellar interiors and atmospheres. An important role is played by the gradient of partial radiative pressure, or radiative acceleration, which is usually neglected in stellar evolution. In Part II, the authors systematically review the contribution of atomic diffusion to each evolutionary step. The dominant effects of atomic diffusion are accompanied by more subtle effects on a large number of structural properties throughout evolution. One of the goals of this book is to provide the means for the astrophysicist or graduate student to evaluate the importanc...

  17. Degenerate nonlinear diffusion equations

    CERN Document Server

    Favini, Angelo

    2012-01-01

    The aim of these notes is to include in a uniform presentation style several topics related to the theory of degenerate nonlinear diffusion equations, treated in the mathematical framework of evolution equations with multivalued m-accretive operators in Hilbert spaces. The problems concern nonlinear parabolic equations involving two cases of degeneracy. More precisely, one case is due to the vanishing of the time derivative coefficient and the other is provided by the vanishing of the diffusion coefficient on subsets of positive measure of the domain. From the mathematical point of view the results presented in these notes can be considered as general results in the theory of degenerate nonlinear diffusion equations. However, this work does not seek to present an exhaustive study of degenerate diffusion equations, but rather to emphasize some rigorous and efficient techniques for approaching various problems involving degenerate nonlinear diffusion equations, such as well-posedness, periodic solutions, asympt...

  18. Double diffusivity model under stochastic forcing

    Science.gov (United States)

    Chattopadhyay, Amit K.; Aifantis, Elias C.

    2017-05-01

    The "double diffusivity" model was proposed in the late 1970s, and reworked in the early 1980s, as a continuum counterpart to existing discrete models of diffusion corresponding to high diffusivity paths, such as grain boundaries and dislocation lines. It was later rejuvenated in the 1990s to interpret experimental results on diffusion in polycrystalline and nanocrystalline specimens where grain boundaries and triple grain boundary junctions act as high diffusivity paths. Technically, the model pans out as a system of coupled Fick-type diffusion equations to represent "regular" and "high" diffusivity paths with "source terms" accounting for the mass exchange between the two paths. The model remit was extended by analogy to describe flow in porous media with double porosity, as well as to model heat conduction in media with two nonequilibrium local temperature baths, e.g., ion and electron baths. Uncoupling of the two partial differential equations leads to a higher-ordered diffusion equation, solutions of which could be obtained in terms of classical diffusion equation solutions. Similar equations could also be derived within an "internal length" gradient (ILG) mechanics formulation applied to diffusion problems, i.e., by introducing nonlocal effects, together with inertia and viscosity, in a mechanics based formulation of diffusion theory. While being remarkably successful in studies related to various aspects of transport in inhomogeneous media with deterministic microstructures and nanostructures, its implications in the presence of stochasticity have not yet been considered. This issue becomes particularly important in the case of diffusion in nanopolycrystals whose deterministic ILG-based theoretical calculations predict a relaxation time that is only about one-tenth of the actual experimentally verified time scale. This article provides the "missing link" in this estimation by adding a vital element in the ILG structure, that of stochasticity, that takes into

  19. Oxygen diffusion in monazite

    Science.gov (United States)

    Cherniak, D. J.; Zhang, X. Y.; Nakamura, M.; Watson, E. B.

    2004-09-01

    We report measurements of oxygen diffusion in natural monazites under both dry, 1-atm conditions and hydrothermal conditions. For dry experiments, 18O-enriched CePO4 powder and monazite crystals were sealed in Ag-Pd capsules with a solid buffer (to buffer at NNO) and annealed in 1-atm furnaces. Hydrothermal runs were conducted in cold-seal pressure vessels, where monazite grains were encapsulated with 18O-enriched water. Following the diffusion anneals, oxygen concentration profiles were measured with Nuclear Reaction Analysis (NRA) using the reaction 18O(p,α)15N. Over the temperature range 850-1100 °C, the Arrhenius relation determined for dry diffusion experiments on monazite is given by: Under wet conditions at 100 MPa water pressure, over the temperature range 700-880 °C, oxygen diffusion can be described by the Arrhenius relationship: Oxygen diffusion under hydrothermal conditions has a significantly lower activation energy for diffusion than under dry conditions, as has been found the case for many other minerals, both silicate and nonsilicate. Given these differences in activation energies, the differences between dry and wet diffusion rates increase with lower temperatures; for example, at 600 °C, dry diffusion will be more than 4 orders of magnitude slower than diffusion under hydrothermal conditions. These disparate diffusivities will result in pronounced differences in the degree of retentivity of oxygen isotope signatures. For instance, under dry conditions (presumably rare in the crust) and high lower-crustal temperatures (∼800 °C), monazite cores of 70-μm radii will preserve O isotope ratios for about 500,000 years; by comparison, they would be retained at this temperature under wet conditions for about 15,000 years.

  20. Characterization of resistance mechanisms and genetic relatedness of carbapenem-resistant Acinetobacter baumannii isolated from blood, Italy.

    Science.gov (United States)

    Migliavacca, Roberta; Espinal, Paula; Principe, Luigi; Drago, Monica; Fugazza, Giulia; Roca, Ignasi; Nucleo, Elisabetta; Bracco, Silvia; Vila, Jordi; Pagani, Laura; Luzzaro, Francesco

    2013-02-01

    The aim of this study was to characterize the resistance mechanisms and genetic relatedness of 21 carbapenem-resistant Acinetobacter baumannii blood isolates collected in Italy during a 1-year multicenter prospective surveillance study. Genes coding for carbapenemase production were identified by polymerase chain reaction (PCR) and sequencing. Pulsed-field gel electrophoresis (PFGE), multiplex PCRs for group identification, and multilocus sequence typing (MLST) were used to determine genetic relationships. Carbapenem resistance was consistently related to the production of oxacillinases, mostly the plasmid-mediated OXA-58 enzyme. Strains producing the OXA-23 enzyme (chromosomally mediated) were also detected. Seven PFGE clones were identified, some of which being related to international (ICL- I and ICL-II) or national clonal lineages. Multiplex PCRs identified 4 different groups (group 2 being dominant), further distinguishable in 6 sequence types by MLST. The heterogeneity of profiles highlights the diffusion of international and national clonal lineages in Italy. Continuous surveillance is needed for monitoring the spread of these worrisome strains equipped with multiple drug resistance mechanisms. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Relative Roles of Gap Junction Channels and Cytoplasm in Cell-to-Cell Diffusion of Fluorescent Tracers

    Science.gov (United States)

    Safranyos, Richard G. A.; Caveney, Stanley; Miller, James G.; Petersen, Nils O.

    1987-04-01

    Intercellular (tissue) diffusion of molecules requires cytoplasmic diffusion and diffusion through gap junctional (or cell-to-cell) channels. The rates of tissue and cytoplasmic diffusion of fluorescent tracers, expressed as an effective diffusion coefficient, De, and a cytoplasmic diffusion coefficient, Dcyt, have been measured among the developing epidermal cells of a larval beetle, Tenebrio molitor L., to determine the contribution of the junctional channels to intercellular diffusion. Tracer diffusion was measured by injecting fluorescent tracers into cells and quantitating the rate of subsequent spread into adjacent cells. Cytoplasmic diffusion was determined by fluorescence photobleaching. These experiments show that gap junctional channels constitute approximately 70-80% of the total cell-to-cell resistance to the diffusion of organic tracers at high concentrations in this tissue. At low concentrations, however, the binding of tracer to cytoplasm slows down the cytoplasmic diffusion, which may limit intercellular diffusion.

  2. Internal Entrepreneurship--A Trojan Horse of the Neoliberal Governance of Education? Finnish Pre- and In-Service Teachers' Implementation of and Resistance towards Entrepreneurship Education

    Science.gov (United States)

    Komulainen, Katri; Naskali, Paivi; Korhonen, Maija; Keskitalo-Foley, Seija

    2011-01-01

    This paper explores the effects of neoliberal education policies, by examining how the Finnish pre- and in-service teachers engage with the discourses of "external" and "internal entrepreneurship", create related inclusions and exclusions, and implement or challenge the aim of educating enterprising and entrepreneurial…

  3. 16 Weeks of Training with the International Space Station Advanced Resistive Exercise Device (aRED) Is not Different than Training with Free Weights

    Science.gov (United States)

    Loehr, J. A.; Lee, S. M. C.; English, K. E.; Leach, M.; Bentley, J.; Nash, R.; Hagan, R. D.

    2008-01-01

    The advanced Resistive Exercise Device (aRED) is a resistive exercise system designed to maintain muscle mass and strength in microgravity by simulating free weight (FW) exercise. aRED utilizes vacuum cylinders and inertial flywheels to replicate the constant mass and inertial components, respectively, of FW exercise in normal gravity. PURPOSE: To compare the effectiveness of aRED and FW resistive exercise training in ambulatory subjects. METHODS: Untrained subjects were assigned to two groups, FW (6 males, 3 females) and aRED (8 males, 3 females), and performed squat (SQ), heel raise (HR), and deadlift (DL) exercises 3 d wk-1 for 16 wks. SQ, HR and DL strength (1RM) were measured using FW hardware pre-, mid- and post-training. Subjects participated in a periodized training protocol with the exercise prescription based on a percentage of 1RM. Thigh and lower leg muscle volume were assessed using Magnetic Resonance Imaging (MRI), and leg (LLM) and total body lean mass (BLM) were measured using Dual Energy X-ray Absorptiometry (DXA) pre- and post-training. RESULTS: SQ 1RM increased in both FW (48.9+/-6.1%) and aRED (31.2+/-3.8%) groups, and there was a greater training response in FW compared with aRED (p=0.01). HR and DL 1RM increased in FW (HR: 12.3+/-2.4%, DL: 23.3+/-4.4%) and aRED (HR: 18.0+/-1.6%, DL: 23.2+'-2.8%), but there were no differences between groups. Thigh muscle volume was greater following training in both groups (FW: 9.8+/-0.9%, aRED: 7.1+/-1.2%) but lower leg muscle volume increased only in the FW group (3.0+/-1.1%). Lean tissue mass increased in both FW (LLM: 3.9+/-1.1%, BLM: 2.5+/-0.7%) and aRED (LLM: 4.8+/-0.7%, BLM: 2.6 0.7%). There were no between group differences in muscle volume or lean mass in response to training. CONCLUSIONS: In general, the increase in muscle strength, muscle volume, and lean tissue mass when training with aRED was not different than when using the same training protocol with FW. The smaller increase in SQ 1RM in the a

  4. Combined DC resistivity and induced polarization (DC-IP) for mapping the internal composition of a mine waste rock pile in Nova Scotia, Canada

    Science.gov (United States)

    Power, Christopher; Tsourlos, Panagiotis; Ramasamy, Murugan; Nivorlis, Aristeidis; Mkandawire, Martin

    2018-03-01

    Mine waste rock piles (WRPs) can contain sulfidic minerals whose interaction with oxygen and water can generate acid mine drainage (AMD). Thus, WRPs can be a long-term source of environmental pollution. Since the generation of AMD and its release into the environment is dependent on the net volume and bulk composition of waste rock, effective characterization of WRPs is necessary for successful remedial design and monitoring. In this study, a combined DC resistivity and induced polarization (DC-IP) approach was employed to characterize an AMD-generating WRP in the Sydney Coalfield, Nova Scotia, Canada. Two-dimensional (2D) DC-IP imaging with 6 survey lines was performed to capture the full WRP landform. 2D DC results indicated a highly heterogeneous and moderately conductive waste rock underlain by a resistive bedrock containing numerous fractures. 2D IP (chargeability) results identified several highly-chargeable regions within the waste, with normalized chargeability delineating regions specific to waste mineralogy only. Three-dimensional (3D) DC-IP imaging, using 17 parallel lines on the plateau of the pile, was then used to focus on the composition of the waste rock. The full 3D inverted DC-IP distributions were used to identify coincident and continuous zones (isosurfaces) of low resistivity (0.4 mS/m) that were inferred as generated AMD (leachate) and stored AMD (sulfides), respectively. Integrated geological, hydrogeological and geochemical data increased confidence in the geoelectrical interpretations. Knowledge on the location of potentially more reactive waste material is extremely valuable for improved long-term AMD monitoring at the WRP.

  5. Factors affecting the diffusion of online end user literature searching.

    Science.gov (United States)

    Ash, J S

    1999-01-01

    The aim of this study was to identify factors that affect diffusion of usage of online end user literature searching. Fifteen factors clustered into three attribute sets (innovation attributes, organizational attributes, and marketing attributes) were measured to study their effect on the diffusion of online searching within institutions. A random sample of sixty-seven academic health sciences centers was selected and then 1,335 library and informatics staff members at those institutions were surveyed by mail with electronic mail follow-up. Multiple regression analysis was performed. The survey yielded a 41% response rate with electronic mail follow-up being particularly effective. Two dependent variables, internal diffusion (spread of diffusion) and infusion (depth of diffusion), were measured. There was little correlation between them, indicating they measured different things. Fifteen independent variables clustered into three attribute sets were measured. The innovation attributes set was significant for both internal diffusion and infusion. Significant individual variables were visibility for internal diffusion and image enhancement effects (negative relation) as well as visibility for infusion (depth of diffusion). Organizational attributes were also significant predictors for both dependent variables. No individual variables were significant for internal diffusion. Communication, management support (negative relation), rewards, and existence of champions were significant for infusion. Marketing attributes were not significant predictors. Successful diffusion of online end user literature searching is dependent on the visibility of the systems, communication among, rewards to, and peers of possible users who promote use (champions). Personal image enhancement effects have a negative relation to infusion, possibly because the use of intermediaries is still seen as the more luxurious way to have searches done. Management support also has a negative relation to

  6. Diffuse interstellar clouds

    International Nuclear Information System (INIS)

    Black, J.H.

    1987-01-01

    The author defines and discusses the nature of diffuse interstellar clouds. He discusses how they contribute to the general extinction of starlight. The atomic and molecular species that have been identified in the ultraviolet, visible, and near infrared regions of the spectrum of a diffuse cloud are presented. The author illustrates some of the practical considerations that affect absorption line observations of interstellar atoms and molecules. Various aspects of the theoretical description of diffuse clouds required for a full interpretation of the observations are discussed

  7. Infrared diffuse interstellar bands

    Science.gov (United States)

    Galazutdinov, G. A.; Lee, Jae-Joon; Han, Inwoo; Lee, Byeong-Cheol; Valyavin, G.; Krełowski, J.

    2017-05-01

    We present high-resolution (R ˜ 45 000) profiles of 14 diffuse interstellar bands in the ˜1.45 to ˜2.45 μm range based on spectra obtained with the Immersion Grating INfrared Spectrograph at the McDonald Observatory. The revised list of diffuse bands with accurately estimated rest wavelengths includes six new features. The diffuse band at 15 268.2 Å demonstrates a very symmetric profile shape and thus can serve as a reference for finding the 'interstellar correction' to the rest wavelength frame in the H range, which suffers from a lack of known atomic/molecular lines.

  8. Self diffusion in tungsten

    International Nuclear Information System (INIS)

    Mundy, J.N.; Rothman, S.J.; Lam, N.Q.; Nowicki, L.J.; Hoff, H.A.

    1978-01-01

    The lack of understanding of self-diffusion in Group VI metals together with the wide scatter in the measured values of tungsten self-diffusion has prompted the present measurements to be made over a wide temperature range (1/2Tsub(m) to Tsub(m)). The diffusion coefficients have been measured in the temperature range 1430-2630 0 C. The present measurements show non-linear Arrhenius behavior but a reliable two-exponential fit of the data should await further measurements. (Auth.)

  9. Diffusion of Wilson loops

    International Nuclear Information System (INIS)

    Brzoska, A.M.; Lenz, F.; Thies, M.; Negele, J.W.

    2005-01-01

    A phenomenological analysis of the distribution of Wilson loops in SU(2) Yang-Mills theory is presented in which Wilson loop distributions are described as the result of a diffusion process on the group manifold. It is shown that, in the absence of forces, diffusion implies Casimir scaling and, conversely, exact Casimir scaling implies free diffusion. Screening processes occur if diffusion takes place in a potential. The crucial distinction between screening of fundamental and adjoint loops is formulated as a symmetry property related to the center symmetry of the underlying gauge theory. The results are expressed in terms of an effective Wilson loop action and compared with various limits of SU(2) Yang-Mills theory

  10. Diffusion between evolving interfaces

    International Nuclear Information System (INIS)

    Juntunen, Janne; Merikoski, Juha

    2010-01-01

    Diffusion in an evolving environment is studied by continuous-time Monte Carlo simulations. Diffusion is modeled by continuous-time random walkers on a lattice, in a dynamic environment provided by bubbles between two one-dimensional interfaces driven symmetrically towards each other. For one-dimensional random walkers constrained by the interfaces, the bubble size distribution dominates diffusion. For two-dimensional random walkers, it is also controlled by the topography and dynamics of the interfaces. The results of the one-dimensional case are recovered in the limit where the interfaces are strongly driven. Even with simple hard-core repulsion between the interfaces and the particles, diffusion is found to depend strongly on the details of the dynamical rules of particles close to the interfaces.

  11. 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

  12. Diffusing Best Practices

    DEFF Research Database (Denmark)

    Pries-Heje, Jan; Baskerville, Richard

    2014-01-01

    approach. The study context is a design case in which an organization desires to diffuse its best practices across different groups. The design goal is embodied in organizational mechanisms to achieve this diffusion. The study used Theory of Planned Behavior (TPB) as a kernel theory. The artifacts...... resulting from the design were two-day training workshops conceptually anchored to TBP. The design theory was evaluated through execution of eight diffusion workshops involving three different groups in the same company. The findings indicate that the match between the practice and the context materialized...... that the behavior will be effective). These two factors were especially critical if the source context of the best practice is qualitatively different from the target context into which the organization is seeking to diffuse the best practice....

  13. Detection of diffusible substances

    Energy Technology Data Exchange (ETDEWEB)

    Warembourg, M [Lille-1 Univ., 59 - Villeneuve-d' Ascq (France)

    1976-12-01

    The different steps of a radioautographic technique for the detection of diffusible substances are described. Using this radioautographic method, the topographic distribution of estradiol-concentrating neurons was studied in the nervous system and pituitary of the ovariectomized mouse and guinea-pig. A relatively good morphological preservation of structures can be ascertained on sections from unfixed, unembedded tissues prepared at low temperatures and kept-under relatively low humidity. The translocation or extraction of diffusible substances is avoided by directly mounting of frozen sections on dried photographic emulsion. Since no solvent is used, this technique excludes the major sources of diffusion artifacts and permits to be in favourable conditions for the localization of diffusible substances.

  14. 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.

  15. Drift-Diffusion Equation

    Directory of Open Access Journals (Sweden)

    K. Banoo

    1998-01-01

    equation in the discrete momentum space. This is shown to be similar to the conventional drift-diffusion equation except that it is a more rigorous solution to the Boltzmann equation because the current and carrier densities are resolved into M×1 vectors, where M is the number of modes in the discrete momentum space. The mobility and diffusion coefficient become M×M matrices which connect the M momentum space modes. This approach is demonstrated by simulating electron transport in bulk silicon.

  16. Advanced manufacturing: Technology diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Tesar, A.

    1995-12-01

    In this paper we examine how manufacturing technology diffuses rom the developers of technology across national borders to those who do not have the capability or resources to develop advanced technology on their own. None of the wide variety of technology diffusion mechanisms discussed in this paper are new, yet the opportunities to apply these mechanisms are growing. A dramatic increase in technology diffusion occurred over the last decade. The two major trends which probably drive this increase are a worldwide inclination towards ``freer`` markets and diminishing isolation. Technology is most rapidly diffusing from the US In fact, the US is supplying technology for the rest of the world. The value of the technology supplied by the US more than doubled from 1985 to 1992 (see the Introduction for details). History shows us that technology diffusion is inevitable. It is the rates at which technologies diffuse to other countries which can vary considerably. Manufacturers in these countries are increasingly able to absorb technology. Their manufacturing efficiency is expected to progress as technology becomes increasingly available and utilized.

  17. Diffusive charge transport in graphene

    Science.gov (United States)

    Chen, Jianhao

    The physical mechanisms limiting the mobility of graphene on SiO 2 are studied and printed graphene devices on a flexible substrate are realized. Intentional addition of charged scattering impurities is used to study the effects of charged impurities. Atomic-scale defects are created by noble-gas ions irradiation to study the effect of unitary scatterers. The results show that charged impurities and atomic-scale defects both lead to conductivity linear in density in graphene, with a scattering magnitude that agrees quantitatively with theoretical estimates. While charged impurities cause intravalley scattering and induce a small change in the minimum conductivity, defects in graphene scatter electrons between the valleys and suppress the minimum conductivity below the metallic limit. Temperature-dependent measurements show that longitudinal acoustic phonons in graphene produce a small resistivity which is linear in temperature and independent of carrier density; at higher temperatures, polar optical phonons of the SiO2 substrate give rise to an activated, carrier density-dependent resistivity. Graphene is also made into high mobility transparent and flexible field effect device via the transfer-printing method. Together the results paint a complete picture of charge carrier transport in graphene on SiO2 in the diffusive regime, and show the promise of graphene as a novel electronic material that have potential applications not only on conventional inorganic substrates, but also on flexible substrates.

  18. Statistical model of a gas diffusion electrode. III. Photomicrograph study

    Energy Technology Data Exchange (ETDEWEB)

    Winsel, A W

    1965-12-01

    A linear section through a gas diffusion electrode produces a certain distribution function of sinews with the pores. From this distribution function some qualities of the pore structure are derived, and an automatic device to determine the distribution function is described. With a statistical model of a gas diffusion electrode the behavior of a DSK electrode is discussed and compared with earlier measurements of the flow resistance of this material.

  19. A diffusivity model for predicting VOC diffusion in porous building materials based on fractal theory

    International Nuclear Information System (INIS)

    Liu, Yanfeng; Zhou, Xiaojun; Wang, Dengjia; Song, Cong; Liu, Jiaping

    2015-01-01

    Highlights: • Fractal theory is introduced into the prediction of VOC diffusion coefficient. • MSFC model of the diffusion coefficient is developed for porous building materials. • The MSFC model contains detailed pore structure parameters. • The accuracy of the MSFC model is verified by independent experiments. - Abstract: Most building materials are porous media, and the internal diffusion coefficients of such materials have an important influences on the emission characteristics of volatile organic compounds (VOCs). The pore structure of porous building materials has a significant impact on the diffusion coefficient. However, the complex structural characteristics bring great difficulties to the model development. The existing prediction models of the diffusion coefficient are flawed and need to be improved. Using scanning electron microscope (SEM) observations and mercury intrusion porosimetry (MIP) tests of typical porous building materials, this study developed a new diffusivity model: the multistage series-connection fractal capillary-bundle (MSFC) model. The model considers the variable-diameter capillaries formed by macropores connected in series as the main mass transfer paths, and the diameter distribution of the capillary bundles obeys a fractal power law in the cross section. In addition, the tortuosity of the macrocapillary segments with different diameters is obtained by the fractal theory. Mesopores serve as the connections between the macrocapillary segments rather than as the main mass transfer paths. The theoretical results obtained using the MSFC model yielded a highly accurate prediction of the diffusion coefficients and were in a good agreement with the VOC concentration measurements in the environmental test chamber.

  20. Guidance for the application of an assessment methodology for innovative nuclear energy systems. INPRO manual - Proliferation resistance. Vol. 5 of the final report of phase 1 of the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO)

    International Nuclear Information System (INIS)

    2008-11-01

    The International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) was initiated in the year 2000, based on a resolution of the IAEA General Conference (GC(44)/RES/21). The main objectives of INPRO are (1) to help to ensure that nuclear energy is available to contribute in fulfilling energy needs in the 21st century in a sustainable manner, (2) to bring together both technology holders and technology users to consider jointly the international and national actions required to achieve desired innovations in nuclear reactors and fuel cycles; and (3) to create a forum to involve all relevant stakeholders that will have an impact on, draw from, and complement the activities of existing institutions, as well as ongoing initiatives at the national and international level. The INPRO manual is comprised of an overview volume (No. 1), and eight additional volumes covering the areas of economics (Volume 2), infrastructure (Volume 3), waste management (Volume 4), proliferation resistance (laid out in this report) (Volume 5), physical protection (Volume 6), environment (Volume 7), safety of nuclear reactors (Volume 8), and safety of nuclear fuel cycle facilities (Volume 9). This volume of the INPRO manual is based on the results of an INPRO study on proliferation resistance of the DUPIC fuel cycle performed by the Republic of Korea during 2005 and 2006, recommendations from IAEA consultancy meetings, and on a special service agreement with G. Pshakin (Russian Federation). The INPRO Manual starts with an introduction in Chapter 1. In Chapter 2, the necessary information is described to perform an INPRO assessment in the area of proliferation resistance. Explanatory notes on the INPRO basic principles (BP) and user requirements (UR) in the area of proliferation resistance, are reproduced in Chapter 3 to provide context for the assessor; additionally, background of each criterion (CR) and a corresponding procedure is described how to perform an INPRO assessment. The

  1. Lead diffusion in monazite

    International Nuclear Information System (INIS)

    Gardes, E.

    2006-06-01

    Proper knowledge of the diffusion rates of lead in monazite is necessary to understand the U-Th-Pb age anomalies of this mineral, which is one of the most used in geochronology after zircon. Diffusion experiments were performed in NdPO 4 monocrystals and in Nd 0.66 Ca 0.17 Th 0.17 PO 4 polycrystals from Nd 0.66 Pb 0.17 Th 0.17 PO 4 thin films to investigate Pb 2+ + Th 4+ ↔ 2 Nd 3+ and Pb 2+ ↔ Ca 2+ exchanges. Diffusion annealings were run between 1200 and 1500 Celsius degrees, at room pressure, for durations ranging from one hour to one month. The diffusion profiles were analysed using TEM (transmission electronic microscopy) and RBS (Rutherford backscattering spectroscopy). The diffusivities extracted for Pb 2+ + Th 4+ ↔ 2 Nd 3+ exchange follow an Arrhenius law with parameters E equals 509 ± 24 kJ mol -1 and log(D 0 (m 2 s -1 )) equals -3.41 ± 0.77. Preliminary data for Pb 2+ ↔ Ca 2+ exchange are in agreement with this result. The extrapolation of our data to crustal temperatures yields very slow diffusivities. For instance, the time necessary for a 50 μm grain to lose all of its lead at 800 Celsius degrees is greater than the age of the Earth. From these results and other evidence from the literature, we conclude that most of the perturbations in U-Th-Pb ages of monazite cannot be attributed to lead diffusion, but rather to interactions with fluids. (author)

  2. Hydrogen diffusion at moderate temperatures in p-type Czochralski silicon

    International Nuclear Information System (INIS)

    Huang, Y.L.; Ma, Y.; Job, R.; Ulyashin, A.G.

    2004-01-01

    In plasma-hydrogenated p-type Czochralski silicon, rapid thermal donor (TD) formation is achieved, resulting from the catalytic support of hydrogen. The n-type counter doping by TD leads to a p-n junction formation. A simple method for the indirect determination of the diffusivity of hydrogen via applying the spreading resistance probe measurements is presented. Hydrogen diffusion in silicon during both plasma hydrogenation and post-hydrogenation annealing is investigated. The impact of the hydrogenation duration, annealing temperature, and resistivity of the silicon wafers on the hydrogen diffusion is discussed. Diffusivities of hydrogen are determined in the temperature range 270-450 deg. C. The activation energy for the hydrogen diffusion is deduced to be 1.23 eV. The diffusion of hydrogen is interpreted within the framework of a trap-limited diffusion mechanism. Oxygen and hydrogen are found to be the main traps

  3. The update of resist outgas testing for metal containing resists at EIDEC

    Science.gov (United States)

    Shiobara, Eishi; Mikami, Shinji

    2017-10-01

    The metal containing resist is one of the candidates for high sensitivity resists. EIDEC has prepared the infrastructure for outgas testing in hydrogen environment for metal containing resists at High Power EUV irradiation tool (HPEUV). We have experimentally obtained the preliminary results of the non-cleanable metal contamination on witness sample using model material by HPEUV [1]. The metal contamination was observed at only the condition of hydrogen environment. It suggested the generation of volatile metal hydrides by hydrogen radicals. Additionally, the metal contamination on a witness sample covered with Ru was not removed by hydrogen radical cleaning. The strong interaction between the metal hydride and Ru was confirmed by the absorption simulation. Recently, ASML announced a resist outgassing barrier technology using Dynamic Gas Lock (DGL) membrane located between projection optics and wafer stage [2], [3]. DGL membrane blocks the diffusion of all kinds of resist outgassing to the projection optics and prevents the reflectivity loss of EUV mirrors. The investigation of DGL membrane for high volume manufacturing is just going on. It extends the limitation of material design for EUV resists. However, the DGL membrane has an impact for the productivity of EUV scanners due to the transmission loss of EUV light and the necessity of periodic maintenance. The well understanding and control of the outgassing characteristics of metal containing resists may help to improve the productivity of EUV scanner. We consider the outgas evaluation for the resists still useful. For the improvement of resist outgas testing by HPEUV, there are some issues such as the contamination limited regime, the optimization of exposure dose to obtain the measurable contamination film thickness and the detection of minimum amount of metal related outgas species generated. The investigation and improvement for these issues are ongoing. The updates will be presented in the conference. This

  4. Diffusion of innovative domestic heating systems and multi-storey wood-framed buildings in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Mahapatra, Krushna

    2007-10-15

    influence of a national investment subsidy and a local marketing campaign by the district heating company, Jaemtkraft, on the diffusion of district heating. The surveys revealed that about 80% of the respondents, particularly those with resistance heaters, did not intend to install a new heating system. Economic aspects, functional reliability and indoor air quality were found to be the most important factors influencing respondents' choice of a new heating system. Low priority was given to environmental aspects. Since the diffusion of heating systems is largely cost driven, economic policy instruments, e.g. internalizing the external costs, appears to be an effective means of inducing homeowners to install an IHS. Homeowners with resistance heaters accorded more importance to investment cost, and therefore an investment subsidy was more important for them when deciding to install an IHS. Installers were the most important source of information on heating systems. Survey respondents thought that a bedrock heat pump system had advantages with respect to the annual cost of heating, security of fuel supply, environmental benignity, market value of the home and low greenhouse gas emission, a district heating system had advantages regarding functional reliability, system automation and the time required to obtain information, while a pellet boiler system had the advantage of the relatively low investment cost. Thus, a heat pump has more advantages than a pellet boiler, particularly with regard to the most important factor 'annual cost of heating', and therefore diffuses faster. The expansion of district heating networks in the detached home sector, particularly those homes with resistance heaters, is often considered difficult. However, results showed that, in Oestersund, the government investment subsidy and Jaemtkraft's marketing campaign motivated 78% of the homeowners to adopt district heating. The marketing strategy of Jaemtkraft reflects the results

  5. Diffusion tensor MRI: clinical applications

    International Nuclear Information System (INIS)

    Meli, Francisco; Romero, Carlos; Carpintiero, Silvina; Salvatico, Rosana; Lambre, Hector; Vila, Jose

    2005-01-01

    Purpose: To evaluate the usefulness of diffusion-tensor imaging (DTI) on different neurological diseases, and to know if this technique shows additional information than conventional Magnetic Resonance Imaging (MRI). Materials and method: Eight patients, with neurological diseases (five patients with brain tumors, one with multiple sclerosis (MS), one with variant Creutzfeldt-Jakob disease (vCJD) and the other with delayed CO intoxication were evaluated. A MR scanner of 1.5 T was used and conventional sequences and DTI with twenty-five directions were done. Quantitative maps were gotten, where the fractional anisotropy (FA) through regions of interest (ROIs) in specific anatomic area were quantified (i.e.: internal and external capsules, frontal and temporal bundles, corpus fibers). Results: In the patients with brain tumors, there was a decrease of FA on intra and peritumoral fibers. Some of them had a disruption in their pattern. In patients with MS and CO intoxication, partial interruption along white matter bundles was demonstrated. However, a 'mismatch' between the findings of FLAIR, Diffusion-weighted images (DWI) and DTI, in the case of CO intoxication, was seen. Conclusions: DTI gave more information compared to conventional sequences about ultrastructural brain tissue in almost all the diseases above mentioned. Therefore, there is a work in progress about DTI acquisition, to evaluate a new technique, called tractography. (author)

  6. EXPERIMENTAL RESEARCHES OF ELECTRO-THERMAL RESISTIBILITY OF SEND-OFFS AND CABLES TO ACTION RATIONED ON THE INTERNATIONAL STANDARD OF IEC 62305-1-2010 OF APERIODIC IMPULSE OF CURRENT OF ARTIFICIAL LIGHTNING

    Directory of Open Access Journals (Sweden)

    M.I. Baranov

    2016-03-01

    Full Text Available Purpose. Experimental researches of electro-thermal resistibility of cable-explorer products, applied in the power electric circuits of objects of electric-power industry, to action on its copper and aluminum parts bearings a current rationed on the International Standard of IEC 62305-1-2010 aperiodic impulse 10/350 μs of current of artificial lightning. Methodology. Electrophysics bases of technique of high tensions and high pulsed currents (HPC, and also scientific and technical bases of planning of devices of high-voltage impulsive technique and measuring HPC in them. Results. Experimental a way the quantitative levels of maximal values maximum of possible and critical closenesses of aperiodic impulse 10/350 μs of current of artificial lightning with rationed on the international standard of IEC 62305-1-2010 peak-temporal parameters and admittances on them in copper (aluminum parts bearings a current of send-offs and cables with a polyethylene (PET and polyvinylchloride (PVCH isolation. Originality. First in world practice on the unique powerful high-voltage generator of HPC of artificial lightning experimental researches of resistibility to lightning of pre-production models of send-offs (cables are conducted with copper (aluminum tendons, PET and PVCH by an isolation, in-use in power electric circuits of electric-power industry objects. Practical value. The use in practice of protecting from lightning of the got results will allow substantially to promote functional and fire-prevention safety of engineering communications of objects of industrial electroenergy in the conditions of action on them of short shots of linear lightning.

  7. Polymer diffusion in the interphase between surface and solution.

    Science.gov (United States)

    Weger, Lukas; Weidmann, Monika; Ali, Wael; Hildebrandt, Marcus; Gutmann, Jochen Stefan; Hoffmann-Jacobsen, Kerstin

    2018-05-22

    Total internal reflection fluorescence correlation spectroscopy (TIR-FCS) is applied to study the self-diffusion of polyethylene glycol solutions in the presence of weakly attractive interfaces. Glass coverslips modified with aminopropyl- and propyl-terminated silanes are used to study the influence of solid surfaces on polymer diffusion. A model of three phases of polymer diffusion allows to describe the experimental fluorescence autocorrelation functions. Besides the two-dimensional diffusion of adsorbed polymer on the substrate and three-dimensional free diffusion in bulk solution, a third diffusion time scale is observed with intermediate diffusion times. This retarded three-dimensional diffusion in solution is assigned to long range effects of solid surfaces on diffusional dynamics of polymers. The respective diffusion constants show Rouse scaling (D~N -1 ) indicating a screening of hydrodynamic interactions by the presence of the surface. Hence, the presented TIR-FCS method proves to be a valuable tool to investigate the effect of surfaces on polymer diffusion beyond the first adsorbed polymer layer on the 100 nm length scale.

  8. International perspectives on the profile of highly talented international business professionals

    NARCIS (Netherlands)

    van Heugten, Petronella; Heijne-Penninga, Marjolein; Robbe, Patricia; Jaarsma, Debbie

    2017-01-01

    There is a global demand for talented managers and leaders. To meet this demand, higher education institutions are developing talent programs. However, international perception of talent is diffuse. In this study, our profile of highly talented international business professionals was

  9. Diffusion Influenced Adsorption Kinetics.

    Science.gov (United States)

    Miura, Toshiaki; Seki, Kazuhiko

    2015-08-27

    When the kinetics of adsorption is influenced by the diffusive flow of solutes, the solute concentration at the surface is influenced by the surface coverage of solutes, which is given by the Langmuir-Hinshelwood adsorption equation. The diffusion equation with the boundary condition given by the Langmuir-Hinshelwood adsorption equation leads to the nonlinear integro-differential equation for the surface coverage. In this paper, we solved the nonlinear integro-differential equation using the Grünwald-Letnikov formula developed to solve fractional kinetics. Guided by the numerical results, analytical expressions for the upper and lower bounds of the exact numerical results were obtained. The upper and lower bounds were close to the exact numerical results in the diffusion- and reaction-controlled limits, respectively. We examined the validity of the two simple analytical expressions obtained in the diffusion-controlled limit. The results were generalized to include the effect of dispersive diffusion. We also investigated the effect of molecular rearrangement of anisotropic molecules on surface coverage.

  10. Bicarbonate diffusion through mucus.

    Science.gov (United States)

    Livingston, E H; Miller, J; Engel, E

    1995-09-01

    The mucus layer overlying duodenal epithelium maintains a pH gradient against high luminal acid concentrations. Despite these adverse conditions, epithelial surface pH remains close to neutrality. The exact nature of the gradient-forming barrier remains unknown. The barrier consists of mucus into which HCO3- is secreted. Quantification of the ability of HCO3- to establish and maintain the gradient depends on accurate measurement of this ion's diffusion coefficient through mucus. We describe new experimental and mathematical methods for diffusion measurement and report diffusion coefficients for HCO3- diffusion through saline, 5% mucin solutions, and rat duodenal mucus. The diffusion coefficients were 20.2 +/- 0.10, 3.02 +/- 0.31, and 1.81 +/- 0.12 x 10(-6) cm2/s, respectively. Modeling of the mucobicarbonate layer with this latter value suggests that for conditions of high luminal acid strength the neutralization of acid by HCO3- occurs just above the epithelial surface. Under these conditions the model predicts that fluid convection toward the lumen could be important in maintaining the pH gradient. In support of this hypothesis we were able to demonstrate a net luminal fluid flux of 5 microliters.min-1.cm-2 after perfusion of 0.15 N HCl in the rat duodenum.

  11. International Trade. International Business

    OpenAIRE

    Мохнюк, А. М.; Mokhniuk, A. M.

    2015-01-01

    Work programme of the study course “International Trade. International Business” was prepared in accordance with educational and vocational training program for bachelors of training direction 6.030601 “Management”.

  12. Resistance monitoring of human pathogenic bacteria in Germany, SWOT analysis and examples.

    Science.gov (United States)

    Witte, Wolfgang

    2006-06-01

    Determination of antibiotic resistance has two main goals in clinical-microbiological diagnosis. One aspect is preservation of antibacterial chemotherapy. Furthermore, trends in resistance development should be monitored and should serve as an early warning-system for occurrence and spread of new and clinically important antibiotic resistances. Plenty of data on antibiotic resistance is gathered on a routine basis in medical-microbiological diagnosis and often it is stored in electronic databases that could be interlinked. The main reason that the available data is not being used for resistance monitoring in Germany is the widely used methodology of the agar diffusion test. It is the cheapest and by far the most inaccurate method of determining resistance. The test results are not always comparable with tests for all substance groups from national standards (also limited international comparability). Trend analysis of the resistance situation in Germany can therefore only be determined through individual studies. These studies are discussed according to a SWOT analysis (SWOT = Strengths, Weaknesses, Opportunities, Threats).

  13. Publications | Page 248 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Bureaucratic resistance to regulatory reforms : the contrasting experiences in electricity and telecommunications in Brazil (restricted access). The process of regulatory diffusion has been extensively explored in developed countries, but much less so in developing countries. In an attempt to open the black box of the diffusion ...

  14. Ion-plasma diffusion aluminide coatings for gas turbine blades (structure and properties)

    International Nuclear Information System (INIS)

    Muboyadzhyan, S.A.; Budinovskij, S.A.; Terekhova, V.V.

    2003-01-01

    A consideration is given to the ion-plasma method of heart resisting alloy diffusion coating with alloyed aluminides offering some advantages over routine techniques. Specific features of ion-plasma diffusion coatings production at the surface of heart resisting alloys using one- and multistage techniques are studied. The process of formation of coatings (Al-Si-Y, Al-Si-Ni-B, Al-Si-Cr-Y) along with coating effects on long-term heat resistance of nickel base alloys (ZhS6U, VZhL12U, ZhS26VNK) is investigated. The advantages of the new method of diffusion aluminide coatings are reported [ru

  15. Cesium diffusion in graphite

    International Nuclear Information System (INIS)

    Evans, R.B. III; Davis, W. Jr.; Sutton, A.L. Jr.

    1980-05-01

    Experiments on diffusion of 137 Cs in five types of graphite were performed. The document provides a completion of the report that was started and includes a presentation of all of the diffusion data, previously unpublished. Except for data on mass transfer of 137 Cs in the Hawker-Siddeley graphite, analyses of experimental results were initiated but not completed. The mass transfer process of cesium in HS-1-1 graphite at 600 to 1000 0 C in a helium atmosphere is essentially pure diffusion wherein values of (E/epsilon) and ΔE of the equation D/epsilon = (D/epsilon) 0 exp [-ΔE/RT] are about 4 x 10 -2 cm 2 /s and 30 kcal/mole, respectively

  16. Apparatus for diffusion separation

    International Nuclear Information System (INIS)

    Nierenberg, W.A.; Pontius, R.B.

    1976-01-01

    The method of testing the separation efficiency of porous permeable membranes is described which comprises causing a stream of a gaseous mixture to flow into contact with one face of a finely porous permeable membrane under such conditions that a major fraction of the mixture diffuses through the membrane, maintaining a rectangular cross section of the gaseous stream so flowing past said membrane, continuously recirculating the gas that diffuses through said membrane and continuously withdrawing the gas that does not diffuse through said membrane and maintaining the volume of said recirculating gas constant by continuously introducing into said continuously recirculating gas stream a mass of gas equivalent to that which is continuously withdrawn from said gas stream and comparing the concentrations of the light component in the entering gas, the withdrawn gas and the recirculated gas in order to determine the efficiency of said membrane

  17. Diffusion in flexible pipes

    Energy Technology Data Exchange (ETDEWEB)

    Brogaard Kristensen, S.

    2000-06-01

    This report describes the work done on modelling and simulation of the complex diffusion of gas through the wall of a flexible pipe. The diffusion and thus the pressure in annulus depends strongly on the diffusion and solubility parameters of the gas-polymer system and on the degree of blocking of the outer surface of the inner liner due to pressure reinforcements. The report evaluates the basis modelling required to describe the complex geometries and flow patterns. Qualitatively results of temperature and concentration profiles are shown in the report. For the program to serve any modelling purpose in 'real life' the results need to be validated and possibly the model needs corrections. Hopefully, a full-scale test of a flexible pipe will provide the required temperatures and pressures in annulus to validate the models. (EHS)

  18. Distributed Control Diffusion

    DEFF Research Database (Denmark)

    Schultz, Ulrik Pagh

    2007-01-01

    . Programming a modular, self-reconfigurable robot is however a complicated task: the robot is essentially a real-time, distributed embedded system, where control and communication paths often are tightly coupled to the current physical configuration of the robot. To facilitate the task of programming modular....... This approach allows the programmer to dynamically distribute behaviors throughout a robot and moreover provides a partial abstraction over the concrete physical shape of the robot. We have implemented a prototype of a distributed control diffusion system for the ATRON modular, self-reconfigurable robot......, self-reconfigurable robots, we present the concept of distributed control diffusion: distributed queries are used to identify modules that play a specific role in the robot, and behaviors that implement specific control strategies are diffused throughout the robot based on these role assignments...

  19. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per Kvols

    cooling capacity, energy saving, low investment cost and low noise level; while the limitations include condensation risk and the limit on the room geometry. Furthermore, the crucial design parameters are summarized and their effects on the system performance are discussed. In addition to the stand...... is not well structured with this system. These become the motivations in developing the design guide. This design guide aims to establish a systematic understanding of diffuse ceiling ventilation and provide assistance in designing of such a system. The guide is targeted at design engineers, architects...... and manufacturers and the users of diffuse ceiling technology. The design guide introduces the principle and key characteristics of room air distribution with diffuse ceiling ventilation. It provides an overview of potential benefit and limitations of this technology. The benefits include high thermal comfort, high...

  20. Diffusion and mass transfer

    CERN Document Server

    Vrentas, James S

    2013-01-01

    The book first covers the five elements necessary to formulate and solve mass transfer problems, that is, conservation laws and field equations, boundary conditions, constitutive equations, parameters in constitutive equations, and mathematical methods that can be used to solve the partial differential equations commonly encountered in mass transfer problems. Jump balances, Green’s function solution methods, and the free-volume theory for the prediction of self-diffusion coefficients for polymer–solvent systems are among the topics covered. The authors then use those elements to analyze a wide variety of mass transfer problems, including bubble dissolution, polymer sorption and desorption, dispersion, impurity migration in plastic containers, and utilization of polymers in drug delivery. The text offers detailed solutions, along with some theoretical aspects, for numerous processes including viscoelastic diffusion, moving boundary problems, diffusion and reaction, membrane transport, wave behavior, sedime...

  1. Diffusion in flexible pipes

    Energy Technology Data Exchange (ETDEWEB)

    Brogaard Kristensen, S

    2000-06-01

    This report describes the work done on modelling and simulation of the complex diffusion of gas through the wall of a flexible pipe. The diffusion and thus the pressure in annulus depends strongly on the diffusion and solubility parameters of the gas-polymer system and on the degree of blocking of the outer surface of the inner liner due to pressure reinforcements. The report evaluates the basis modelling required to describe the complex geometries and flow patterns. Qualitatively results of temperature and concentration profiles are shown in the report. For the program to serve any modelling purpose in 'real life' the results need to be validated and possibly the model needs corrections. Hopefully, a full-scale test of a flexible pipe will provide the required temperatures and pressures in annulus to validate the models. (EHS)

  2. The arbitrary order mimetic finite difference method for a diffusion equation with a non-symmetric diffusion tensor

    Science.gov (United States)

    Gyrya, V.; Lipnikov, K.

    2017-11-01

    We present the arbitrary order mimetic finite difference (MFD) discretization for the diffusion equation with non-symmetric tensorial diffusion coefficient in a mixed formulation on general polygonal meshes. The diffusion tensor is assumed to be positive definite. The asymmetry of the diffusion tensor requires changes to the standard MFD construction. We present new approach for the construction that guarantees positive definiteness of the non-symmetric mass matrix in the space of discrete velocities. The numerically observed convergence rate for the scalar quantity matches the predicted one in the case of the lowest order mimetic scheme. For higher orders schemes, we observed super-convergence by one order for the scalar variable which is consistent with the previously published result for a symmetric diffusion tensor. The new scheme was also tested on a time-dependent problem modeling the Hall effect in the resistive magnetohydrodynamics.

  3. Multidrug-Resistant Mycobacterium tuberculosis of the Latin American Mediterranean Lineage, Wrongly Identified as Mycobacterium pinnipedii (Spoligotype International Type 863 [SIT863]), Causing Active Tuberculosis in South Brazil

    KAUST Repository

    Dalla Costa, Elis R.; Vasconcelos, Sidra E. G.; Esteves, Leonardo S.; Gomes, Harrison M.; Gomes, Lia L.; Almeida da Silva, Pedro; Perdigã o, Joã o; Portugal, Isabel; Viveiros, Miguel; McNerney, Ruth; Pain, Arnab; Clark, Taane G.; Rastogi, Nalin; Unis, Gisela; Rossetti, Maria Lucia R.; Suffys, Philip Noel

    2015-01-01

    We recently detected the spoligotype patterns of strains of Mycobacterium pinnipedii, a species of the Mycobacterium tuberculosis complex, in sputum samples from nine cases with pulmonary tuberculosis residing in Porto Alegre, South Brazil. Because this species is rarely encountered in humans, we further characterized these nine isolates by additional genotyping techniques, including 24-locus mycobacterial interspersed repetitive-unit–variable-number tandem-repeat (MIRU-VNTR) typing, verification of the loci TbD1, RD9, pks15/1, RDRio, and fbpC, the insertion of IS6110 at a site specific to the M. tuberculosis Latin American Mediterranean (LAM) lineage, and whole-genome sequencing. The combined analysis of these markers revealed that the isolates are in fact M. tuberculosis and more specifically belong to the LAM genotype. Most of these isolates (n = 8) were shown to be multidrug resistant (MDR), which prompted us to perform partial sequencing of the rpoA, rpoB, rpoC, katG, and inhA genes. Seven isolates (77.8%) carried the S315T mutation in katG, and one of these (11%) also presented the C(−17)T single-nucleotide polymorphism (SNP) in inhA. Interestingly, six of the MDR isolates also presented an undescribed insertion of 12 nucleotides (CCA GAA CAA CCC) in codon 516 of rpoB. No putative compensatory mutation was found in either rpoA or rpoC. This is the first report of an M. tuberculosis LAM family strain with a convergent M. pinnipedii spoligotype. These spoligotypes are observed in genotype databases at a modest frequency, highlighting that care must be taken when identifying isolates in the M. tuberculosis complex on the basis of single genetic markers.

  4. Multidrug-Resistant Mycobacterium tuberculosis of the Latin American Mediterranean Lineage, Wrongly Identified as Mycobacterium pinnipedii (Spoligotype International Type 863 [SIT863]), Causing Active Tuberculosis in South Brazil

    KAUST Repository

    Dalla Costa, Elis R.

    2015-09-23

    We recently detected the spoligotype patterns of strains of Mycobacterium pinnipedii, a species of the Mycobacterium tuberculosis complex, in sputum samples from nine cases with pulmonary tuberculosis residing in Porto Alegre, South Brazil. Because this species is rarely encountered in humans, we further characterized these nine isolates by additional genotyping techniques, including 24-locus mycobacterial interspersed repetitive-unit–variable-number tandem-repeat (MIRU-VNTR) typing, verification of the loci TbD1, RD9, pks15/1, RDRio, and fbpC, the insertion of IS6110 at a site specific to the M. tuberculosis Latin American Mediterranean (LAM) lineage, and whole-genome sequencing. The combined analysis of these markers revealed that the isolates are in fact M. tuberculosis and more specifically belong to the LAM genotype. Most of these isolates (n = 8) were shown to be multidrug resistant (MDR), which prompted us to perform partial sequencing of the rpoA, rpoB, rpoC, katG, and inhA genes. Seven isolates (77.8%) carried the S315T mutation in katG, and one of these (11%) also presented the C(−17)T single-nucleotide polymorphism (SNP) in inhA. Interestingly, six of the MDR isolates also presented an undescribed insertion of 12 nucleotides (CCA GAA CAA CCC) in codon 516 of rpoB. No putative compensatory mutation was found in either rpoA or rpoC. This is the first report of an M. tuberculosis LAM family strain with a convergent M. pinnipedii spoligotype. These spoligotypes are observed in genotype databases at a modest frequency, highlighting that care must be taken when identifying isolates in the M. tuberculosis complex on the basis of single genetic markers.

  5. Measurement of diffusive properties of intact rock

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, K B

    1996-12-01

    In the Postclosure Assessment of a Reference System for the Disposal of Canada`s Nuclear Fuel Waste (Goodwin et al. 1994) the disposal vault is assumed to be surrounded by a zone of intact rock, referred to as the `exclusion zone.` A sensitivity analysis of the relative effectiveness of the several engineered and natural barriers that contribute to the safety of the reference disposal system has shown that this zone of intact rock is the most effective of these barriers to the movement of radionuclides through the reference system. Peer review of the geosphere model used in the case study for the EIS (Environmental Impact Statement) of the Canadian Nuclear Fuel Waste Management Program has identified the need to quantify the properties of the intact rock surrounding the disposal vault that would control the transport of radionuclides by diffusion. The Postclosure Assessment also identified the need for appropriate values of the free water diffusion coefficient (D{sub o}) for {sup 129}1 and {sup 14}C. The measurement of rock resistivity allows the calculation of the Formation Factor for a rock This review describes the Formation Factor, diffusivity, permeability, and porosity, and how these properties might be measured or inferred for insitu rock under the conditions that apply to the intact rock surrounding a potential disposal vault. The importance of measuring the intrinsic diffusion coefficient (D{sup i}) of diffusing species under solution salinities simulating those of groundwaters is emphasised, and a method of measurement is described that is independent of the diffusing medium, and which would be appropriate for measurements made in chemically complex media such as groundwaters. (author). 95 refs., 4 tabs., 39 figs.

  6. Measurement of diffusive properties of intact rock

    International Nuclear Information System (INIS)

    Harvey, K.B.

    1996-12-01

    In the Postclosure Assessment of a Reference System for the Disposal of Canada's Nuclear Fuel Waste (Goodwin et al. 1994) the disposal vault is assumed to be surrounded by a zone of intact rock, referred to as the 'exclusion zone.' A sensitivity analysis of the relative effectiveness of the several engineered and natural barriers that contribute to the safety of the reference disposal system has shown that this zone of intact rock is the most effective of these barriers to the movement of radionuclides through the reference system. Peer review of the geosphere model used in the case study for the EIS (Environmental Impact Statement) of the Canadian Nuclear Fuel Waste Management Program has identified the need to quantify the properties of the intact rock surrounding the disposal vault that would control the transport of radionuclides by diffusion. The Postclosure Assessment also identified the need for appropriate values of the free water diffusion coefficient (D o ) for 129 1 and 14 C. The measurement of rock resistivity allows the calculation of the Formation Factor for a rock This review describes the Formation Factor, diffusivity, permeability, and porosity, and how these properties might be measured or inferred for insitu rock under the conditions that apply to the intact rock surrounding a potential disposal vault. The importance of measuring the intrinsic diffusion coefficient (D i ) of diffusing species under solution salinities simulating those of groundwaters is emphasised, and a method of measurement is described that is independent of the diffusing medium, and which would be appropriate for measurements made in chemically complex media such as groundwaters. (author). 95 refs., 4 tabs., 39 figs

  7. The Trouble with Diffusion

    Directory of Open Access Journals (Sweden)

    R.T. DeHoff

    2002-09-01

    Full Text Available The phenomenological formalism, which yields Fick's Laws for diffusion in single phase multicomponent systems, is widely accepted as the basis for the mathematical description of diffusion. This paper focuses on problems associated with this formalism. This mode of description of the process is cumbersome, defining as it does matrices of interdiffusion coefficients (the central material properties that require a large experimental investment for their evaluation in three component systems, and, indeed cannot be evaluated for systems with more than three components. It is also argued that the physical meaning of the numerical values of these properties with respect to the atom motions in the system remains unknown. The attempt to understand the physical content of the diffusion coefficients in the phenomenological formalism has been the central fundamental problem in the theory of diffusion in crystalline alloys. The observation by Kirkendall that the crystal lattice moves during diffusion led Darken to develop the concept of intrinsic diffusion, i.e., atom motion relative to the crystal lattice. Darken and his successors sought to relate the diffusion coefficients computed for intrinsic fluxes to those obtained from the motion of radioactive tracers in chemically homogeneous samples which directly report the jump frequencies of the atoms as a function of composition and temperature. This theoretical connection between tracer, intrinsic and interdiffusion behavior would provide the basis for understanding the physical content of interdiffusion coefficients. Definitive tests of the resulting theoretical connection have been carried out for a number of binary systems for which all three kinds of observations are available. In a number of systems predictions of intrinsic coefficients from tracer data do not agree with measured values although predictions of interdiffusion coefficients appear to give reasonable agreement. Thus, the complete

  8. Nonlinear diffusion equations

    CERN Document Server

    Wu Zhuo Qun; Li Hui Lai; Zhao Jun Ning

    2001-01-01

    Nonlinear diffusion equations, an important class of parabolic equations, come from a variety of diffusion phenomena which appear widely in nature. They are suggested as mathematical models of physical problems in many fields, such as filtration, phase transition, biochemistry and dynamics of biological groups. In many cases, the equations possess degeneracy or singularity. The appearance of degeneracy or singularity makes the study more involved and challenging. Many new ideas and methods have been developed to overcome the special difficulties caused by the degeneracy and singularity, which

  9. Phase transformation and diffusion

    CERN Document Server

    Kale, G B; Dey, G K

    2008-01-01

    Given that the basic purpose of all research in materials science and technology is to tailor the properties of materials to suit specific applications, phase transformations are the natural key to the fine-tuning of the structural, mechanical and corrosion properties. A basic understanding of the kinetics and mechanisms of phase transformation is therefore of vital importance. Apart from a few cases involving crystallographic martensitic transformations, all phase transformations are mediated by diffusion. Thus, proper control and understanding of the process of diffusion during nucleation, g

  10. Ambipolar diffusion in plasma

    International Nuclear Information System (INIS)

    Silva, T.L. da.

    1987-01-01

    Is this thesis, a numerical method for the solution of the linear diffusion equation for a plasma containing two types of ions, with the possibility of charge exchange, has been developed. It has been shown that the decay time of the electron and ion densities is much smaller than that in a plasma containing only a single type of ion. A non-linear diffusion equation, which includes the effects of an external electric field varying linearly in time, to describe a slightly ionized plasma has also been developed. It has been verified that the decay of the electron density in the presence of such an electric field is very slow. (author)

  11. Diffuse axonal injury: detection of changes in anisotropy of water diffusion by diffusion-weighted imaging

    International Nuclear Information System (INIS)

    Chan, J.H.M.; Tsui, E.Y.K.; Yuen, M.K.; Peh, W.C.G.; Fong, D.; Fok, K.F.; Leung, K.M.; Fung, K.K.L.

    2003-01-01

    Myelinated axons of white matter demonstrate prominent directional differences in water diffusion. We performed diffusion-weighted imaging on ten patients with head injury to explore the feasibility of using water diffusion anisotropy for quantitating diffuse axonal injury. We showed significant decrease in diffusion anisotropy indices in areas with or without signal abnormality on T2 and T2*-weighted images. We conclude that the water diffusion anisotropy index a potentially useful, sensitive and quantitative way of diagnosing and assessing patients with diffuse axonal injury. (orig.)

  12. The Borders of EU Competences with Regard to the International Regulation of Intellectual Property Rights: Constructing a Dam to Resist a River Bursting Its Banks

    Directory of Open Access Journals (Sweden)

    Yole Tanghe

    2016-04-01

    Full Text Available In view of the recent negotiations on the highly anticipated Free Trade Agreements to which the EU shall be party ('e.g.' CETA and TTIP, assessing the extent to which the EU can regulate intellectual property rights in its external relations seems relevant. Two recent cases of the Court of Justice of the EU have reversed its landmark decision in Opinion 1/94, in which intellectual property regulation was almost entirely excluded from the EU’s exclusive competence in trade matters. Firstly, in the 'Daiichi Sankyo' case, the Court elaborated upon the EU’s explicit external competence in the field of intellectual property. This explicit competence is provided for by Article 207 TFEU on the common commercial policy, which allows the EU to conclude agreements concerning the ‘commercial aspects of intellectual property’. In the 'Broadcasting Rights' case, the Court founded its decision on the EU’s implied competence to conclude international agreements, as provided for by Article 3(2 TFEU. Considering the outcome of these two judgments, the Court seems to grant the EU a wide scope of action with regard to intellectual property rights. As a consequence, questions arise with regard to the post-Lisbon era role that is left for the Member States in the field of intellectual property. Therefore, the aim of this article is to outline the scope of the EU’s exclusivity in IP matters and to highlight the borders.

  13. Distribution of antibiotic resistance in urban watershed in Japan

    International Nuclear Information System (INIS)

    Ham, Young-Sik; Kobori, Hiromi; Kang, Joo-Hyon; Matsuzaki, Takayuki; Iino, Michiyo; Nomura, Hayashi

    2012-01-01

    Antibiotic-resistant E. coli concentrations showed large spatial and temporal variations, with greater concentrations observed in tributaries and downstream than in the upstream and midstream. Twenty percent of the geometric mean concentrations of antibiotic-resistant E. coli in the Tama River basin (Japan) exceeded the maximum acceptable concentration of indicator E. coli established by the USEPA. The indicator E. coli concentrations were positively correlated with those of antibiotic-resistant E. coli and multiple-antibiotic-resistant E. coli (resistance to more than two kinds of antibiotics), respectively, but not the detection rate of antibiotic-resistant E. coli, implying that use of antibiotic-resistant E. coli concentration rather than the detection rate can be a better approach for water quality assessment. Multiple-antibiotic-resistant E. coli is a useful indicator for estimating the resistance diffusion, water quality degradation and public health risk potential. This assessment provides beneficial information for setting national regulatory or environmental standards and managing integrated watershed areas. - Highlights: ► We extensively observed antibiotic-resistant E. coli (AREc) in Tama River (Japan). ► AREc count rather than the detection rate is better approach for water quality test. ► Multiple-AREc is resistant to the antibiotic to which single-AREc has no resistance. ► Multiple-AREc increase will accelerate the diffusion of antibiotic resistance. - Multiple-antibiotic-resistant E. coli in the watershed can cause the diffusion of conventionally rare antibiotic resistance.

  14. Anisotropy in "isotropic diffusion" measurements due to nongaussian diffusion

    DEFF Research Database (Denmark)

    Jespersen, Sune Nørhøj; Olesen, Jonas Lynge; Ianuş, Andrada

    2017-01-01

    Designing novel diffusion-weighted NMR and MRI pulse sequences aiming to probe tissue microstructure with techniques extending beyond the conventional Stejskal-Tanner family is currently of broad interest. One such technique, multidimensional diffusion MRI, has been recently proposed to afford...... model-free decomposition of diffusion signal kurtosis into terms originating from either ensemble variance of isotropic diffusivity or microscopic diffusion anisotropy. This ability rests on the assumption that diffusion can be described as a sum of multiple Gaussian compartments, but this is often...

  15. Antimicrobial Resistance

    Science.gov (United States)

    ... least 10 countries (Australia, Austria, Canada, France, Japan, Norway, Slovenia, South Africa, Sweden and the United Kingdom ... plan Global report on surveillance Country situation analysis Policy to combat antimicrobial resistance More on antimicrobial resistance ...

  16. Antimicrobial Resistance

    Science.gov (United States)

    ... can prevent and manage antimicrobial resistance. It is collaborating with partners to strengthen the evidence base and ... on the global action plan. WHO has been leading multiple initiatives to address antimicrobial resistance: World Antibiotic ...

  17. Diffusion in building wakes

    International Nuclear Information System (INIS)

    Ramsdell, J.V.

    1988-03-01

    Straight-line Gaussian models adequately describe atmospheric diffusion for many applications. They have been modified for use in estimating diffusion in building wakes by adding terms that include projected building area and by redefining the diffusion coefficients so that the coefficients have minimum values that are related to building dimensions. In a recent study, Ramsdell reviewed the building-wake dispersion models used by the Nuclear Regulatory Commission (NRC) in its control room habitability assessments. The review included comparison of model estimates of centerline concentrations with concentrations observed in experiments at seven nuclear reactors. In general, the models are conservative in that they tend to predict concentrations that are greater than those actually observed. However, the models show little skill in accounting for variations in the observed concentrations. Subsequently, the experimental data and multiples linear regression techniques have been used to develop a new building wake diffusion model. This paper describes the new building wake model and compares it with other models. 8 refs., 2 figs

  18. Osmosis and Diffusion

    Science.gov (United States)

    Sack, Jeff

    2005-01-01

    OsmoBeaker is a CD-ROM designed to enhance the learning of diffusion and osmosis by presenting interactive experimentation to the student. The software provides several computer simulations that take the student through different scenarios with cells, having different concentrations of solutes in them.

  19. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Sporring, Jon; Fogh Olsen, Ole

    2008-01-01

    . To address this problem, we introduce a photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way, we preserve important illumination features, while...

  20. Bronnen van diffuse bodembelasting

    NARCIS (Netherlands)

    Lijzen JPA; Ekelenkamp A; LBG; DGM/BO

    1995-01-01

    The aim of this study was to support the policy on preventive soil protection with information on the diffuse (non-local) emissions to soil and the influence on future soil quality. This study is related to inventories on (potential) sources of local soil pollution (e.g. industrial areas,

  1. Diffusion in glass

    Energy Technology Data Exchange (ETDEWEB)

    Mubarak, A S

    1991-12-31

    Rutherford backscattering spectromertry technique (RBS) was used to characterize and investigate the depth distribution profiles of Ca-impurities of Ca-doped soda-time glass. The purposely added Ca-impurities were introduced inti the glass matrix by a normal ion exchange diffusion process. The measurements and analysis were performed using 2 MeV {sup 2}He{sup +} ions supplied from the University of Jordan Van de Graff acceierator (JOVAG). The normalized concetration versus depth profile distributions for the Ca-imourities were determined, both theoretically and experimentally. The theoretical treatment was carried out by setting up and soiving the diffusion equation under the conditions of the experiment. The resulting profiles are characterized by a compiementary error function. the theoretical treeatment was extended to include the various methods of enhancing the diffusion process, e.g. using an electric field. The diffusion coefficient, assumed constant, of the Ca-impurities exchanged in the soda-lime glass was determined to be 1.23 x 10{sup 13} cm{sup 2}/s. A comparison between theoretically and experimentally determined profiles is made and commented at, where several conclusions are drawn and suggestions for future work are mentioned. (author). 38 refs., 21 figs., 10 Tabs.

  2. Diffusion or bulk flow

    DEFF Research Database (Denmark)

    Schulz, Alexander

    2015-01-01

    is currently matter of discussion, called passive symplasmic loading. Based on the limited material available, this review compares the different loading modes and suggests that diffusion is the driving force in apoplasmic loaders, while bulk flow plays an increasing role in plants having a continuous...

  3. Multienergy anomalous diffuse scattering

    Czech Academy of Sciences Publication Activity Database

    Kopecký, Miloš; Fábry, Jan; Kub, Jiří; Lausi, A.; Busetto, E.

    2008-01-01

    Roč. 100, č. 19 (2008), 195504/1-195504/4 ISSN 0031-9007 R&D Projects: GA AV ČR IAA100100529 Institutional research plan: CEZ:AV0Z10100523 Keywords : diffuse scattering * x-rays * structure determination Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.180, year: 2008

  4. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Yu, Tao; Heiselberg, Per Kvols

    with conventional ventilation systems (mixing or displacement ventilation), diffuse ceiling ventilation can significantly reduce or even eliminate draught risk in the occupied zone. Moreover, this ventilation system presents a promising opportunity for energy saving, because of the low pressure loss, extended free...

  5. Diffuse Ceiling Ventilation

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per; Nielsen, Peter V.

    2014-01-01

    As a novel air distribution system, diffuse ceiling ventilation combines the suspended acoustic ceiling with ventilation supply. Due to the low-impulse supply from the large ceiling area, the system does not generate draught when supplying cold air. However, heat sources play an important role...

  6. Diffusion in ceramics

    CERN Document Server

    Pelleg, Joshua

    2016-01-01

    This textbook provides an introduction to changes that occur in solids such as ceramics, mainly at high temperatures, which are diffusion controlled, as well as presenting research data. Such changes are related to the kinetics of various reactions such as precipitation, oxidation and phase transformations, but are also related to some mechanical changes, such as creep. The book is composed of two parts, beginning with a look at the basics of diffusion according to Fick's Laws. Solutions of Fick’s second law for constant D, diffusion in grain boundaries and dislocations are presented along with a look at the atomistic approach for the random motion of atoms. In the second part, the author discusses diffusion in several technologically important ceramics. The ceramics selected are monolithic single phase ones, including: A12O3, SiC, MgO, ZrO2 and Si3N4. Of these, three refer to oxide ceramics (alumina, magnesia and zirconia). Carbide based ceramics are represented by the technologically very important Si-ca...

  7. A study of the diffusion mechanisms in amorphous metallic alloys: diffusion and diffusion under high pressure in an amorphous NiZr alloy; Contribution a l`etude des mecanismes de transport dans les materiaux metalliques amorphes: diffusion et diffusion sous pression dans NiZr amorphe

    Energy Technology Data Exchange (ETDEWEB)

    Grandjean, A.

    1996-03-01

    The aim of this work is a better understanding of the diffusion mechanism in amorphous metallic alloys. Then interdiffusion and hafnium diffusion in amorphous NiZr alloy have been studied. Samples used are made by sputtering co-deposition under vacuum and are well relaxed before the diffusion measurements. The time evolution of resistivity during annealing due to the decay of a composition modulated film has been measured and from this change in resistivity interdiffusion coefficients have been determined. Dependence of Hf diffusion on temperature and pressure has been studied using (SIMS). In this two cases, the diffusion process obeys an Arrhenius law and gives an activation energy of 1.33 eV for interdiffusion, and 0.76 eV for Hf diffusion. An effect of pressure on Hf diffusion has been found leading to an activation volume of 8.5 angstrom{sup 3}. Thanks to these results, two approaches of the diffusion mechanisms in these systems have been proposed. The first comes from a comparison with the diffusion mechanisms in crystalline metals, that is to say by point defects. The second is an hypothesis of collective motions in these non crystalline alloys. (author).

  8. Silicide-to-silicon specific contact resistance characterization

    NARCIS (Netherlands)

    Stavitski, N.

    2009-01-01

    The performance of Si integrated circuits depends on the transistor drive current. The drive current of a MOS transistor is determined by the total device resistance, which consists of the channel resistance and the parasitic resistances associated with dopant diffusion areas and contacts. It is

  9. Antibiotic resistant profile of Streptococcus pneumoniae from the ...

    African Journals Online (AJOL)

    The isolates were subjected to antimicrobial susceptibility testing using the disc diffusion method. Results: S. pneumoniae was isolated from 37(42.04%) of the 88 samples. Isolates showed the highest resistance of 12 (32.43%) to erythromycin and lowest resistance of 4(10.81%) to ciprofloxacin. The resistance profiles for ...

  10. Restrictive liquid-phase diffusion and reaction in bidispersed catalysts

    International Nuclear Information System (INIS)

    Lee, S.Y.; Seader, J.D.; Tsai, C.H.; Massoth, F.E.

    1991-01-01

    In this paper, the effect of bidispersed pore-size distribution on liquid-phase diffusion and reaction in NiMo/Al 2 O 3 catalysts is investigated by applying two bidispersed-pore-structure models, the random-pore model and a globular-structure model, to extensive experimental data, which were obtained from sorptive diffusion measurements at ambient conditions and catalytic reaction rate measurements on nitrogen-containing compounds. Transport of the molecules in the catalysts was found to be controlled by micropore diffusion, in accordance with the random-pore model, rather than macropore diffusion as predicted by the globular-structure model. A qualitative criterion for micropore-diffusion control is proposed: relatively small macroporosity and high catalyst pellet density. Since most hydrotreating catalysts have high density, diffusion in these types of catalysts may be controlled by micropore diffusion. Accordingly, it is believed in this case that increasing the size of micropores may be more effective to reduce intraparticle diffusion resistance than incorporating macropores alone

  11. Beta limit of resistive plasma in Torsatron / Heliotron

    International Nuclear Information System (INIS)

    Itoh, K.; Ichiguchi, K.; Itoh, S.I.

    1992-02-01

    Stability against the interchange mode in the Torsatron / Heliotron device is investigated, taking into account the effects of the resistivity, current diffusivity, ion viscosity and thermal diffusivity. Critical beta for the low-mode-number stability is found at the finite beta value. For the range of plasma parameters of the present experiments, the resistive mode and current diffusive mode set comparable critical beta values, which are consistent with experimental observations. In future high temperature plasmas, the current diffusive mode determines the stability limit for the global mode. (author)

  12. Antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Marianne Frieri

    2017-07-01

    Full Text Available Summary: Antimicrobial resistance in bacterial pathogens is a challenge that is associated with high morbidity and mortality. Multidrug resistance patterns in Gram-positive and -negative bacteria are difficult to treat and may even be untreatable with conventional antibiotics. There is currently a shortage of effective therapies, lack of successful prevention measures, and only a few new antibiotics, which require development of novel treatment options and alternative antimicrobial therapies. Biofilms are involved in multidrug resistance and can present challenges for infection control. Virulence, Staphylococcus aureus, Clostridium difficile infection, vancomycin-resistant enterococci, and control in the Emergency Department are also discussed. Keywords: Antibiotic resistance, Biofilms, Infections, Public health, Emergency Department

  13. Effects of Defects on Hydrogen Diffusion in NbC

    Energy Technology Data Exchange (ETDEWEB)

    Salehinia, Iman, E-mail: isalehinia@niu.edu [Department of Mechanical Engineering, Northern Illinois University, DeKalb, IL 60115 (United States); Mastorakos, Ioannis [Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, NY 13699 (United States); Zbib, Hussein M. [School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164 (United States)

    2017-04-15

    Highlights: • MD simulations are used to study the effects of defects on the H diffusion in NbC. • Buckingham potential is more accurate for diffusion of H atoms than LJ potential. • H diffusion coefficient (D) increases with carbon vacancy concentration. • H diffusion coefficient for 6 Å pore (radius = 6 Å) is as high as that for 20 Å pore. • For small pores, H diffusion coefficient drops notably at elevated temperatures. - Abstract: Exceptional mechanical and physical properties of transition metal carbides and nitrides make them good coating-material candidates for extreme corrosive environments such as oil and natural gas wells. However, existence of small pores, pinholes and columnar structures of these ceramics significantly affect their resistance to corrosion, as pore sites would accelerate the diffusion of corrosive media into the substrate. In this research, molecular dynamics atomistic simulations are employed to investigate the effects of the isolated vacancies and the columnar structure on the diffusion rate of H atoms in NbC single crystal at various temperatures. Diffusion coefficient (D) of H atoms in NbC increased with C vacancy concentration. At elevated temperatures, the trapping effect of Nb vacancies is less effective when C vacancies are also present, as H atoms gain enough energy to jump back and forth between the C vacancies. Atomistic simulations also showed a jump in diffusion coefficient for cylindrical pore size of larger than 3 Å radius. Furthermore, D increased monotonically with temperature up to 1000 K in the presence of cylindrical pores. Further increase in temperature resulted in a drop in the diffusion coefficient for small pores while the large pores only showed a lower increasing trend in diffusion coefficient with the temperature.

  14. Electrical resistivity testing for as-built concrete performance assessment of chloride penetration resistance

    NARCIS (Netherlands)

    Polder, R.B.; Peelen, W.H.A.

    2014-01-01

    The electrical resistivity of concrete can provide information about its transport properties, which is relevant for durability performance. For example, resistivity is inversely proportional to chloride diffusion, at least within similar concrete compositions. A methodology is proposed for on-site

  15. Oxygen diffusion in zircon

    Science.gov (United States)

    Watson, E. B.; Cherniak, D. J.

    1997-05-01

    Oxygen diffusion in natural, non-metamict zircon was characterized under both dry and water-present conditions at temperatures ranging from 765°C to 1500°C. Dry experiments were performed at atmospheric pressure by encapsulating polished zircon samples with a fine powder of 18O-enriched quartz and annealing the sealed capsules in air. Hydrothermal runs were conducted in cold-seal pressure vessels (7-70 MPa) or a piston cylinder apparatus (400-1000 MPa) on zircon samples encapsulated with both 18O-enriched quartz and 18O water. Diffusive-uptake profiles of 18O were measured in all samples with a particle accelerator, using the 18O(p, α) 15N reaction. For dry experimental conditions at 1100-1500°C, the resulting oxygen diffusivities (24 in all) are well described by: D dry (m 2/s) = 1.33 × 10 -4exp(-53920/T) There is no suggestion of diffusive anisotropy. Under wet conditions at 925°C, oxygen diffusion shows little or no dependence upon P H 2O in the range 7-1000 MPa, and is insensitive to total pressure as well. The results of 27 wet experiments at 767-1160°C and 7-1000 MPa can be described a single Arrhenius relationship: D wet (m 2/s) = 5.5 × 10 -12exp(-25280/T) The insensitivity of oxygen diffusion to P H 2O means that applications to geologic problems can be pursued knowing only whether the system of interest was 'wet' (i.e., P H 2O > 7MPa ) or 'dry'. Under dry conditions (presumably rare in the crust), zircons are extremely retentive of their oxygen isotopic signatures, to the extent that δ 18O would be perturbed at the center of a 200 μm zircon only during an extraordinarily hot and protracted event (e.g., 65 Ma at 900°C). Under wet conditions, δ 18O may or may not be retained in the central regions of individual crystals, cores or overgrowth rims, depending upon the specific thermal history of the system.

  16. The Pearson diffusions: A class of statistically tractable diffusion processes

    DEFF Research Database (Denmark)

    Forman, Julie Lyng; Sørensen, Michael

    The Pearson diffusions is a flexible class of diffusions defined by having linear drift and quadratic squared diffusion coefficient. It is demonstrated that for this class explicit statistical inference is feasible. Explicit optimal martingale estimating func- tions are found, and the corresponding...

  17. Preparation of a Ni-MgO-Al2O3 catalyst with high activity and resistance to potassium poisoning during direct internal reforming of methane in molten carbonate fuel cells

    Science.gov (United States)

    Jang, Won-Jun; Jung, You-Shick; Shim, Jae-Oh; Roh, Hyun-Seog; Yoon, Wang Lai

    2018-02-01

    Steam reforming of methane (SRM) is conducted using a series of Ni-MgO-Al2O3 catalysts for direct internal reforming (DIR) in molten carbonate fuel cells (MCFCs). Ni-MgO-Al2O3 catalysts are prepared by the homogeneous precipitation method with a variety of MgO loading amounts ranging from 3 to 15 wt%. In addition, each precursor concentrations are systemically changed (Ni: 1.2-4.8 mol L-1; Mg: 0.3-1.2 mol L-1; Al: 0.4-1.6 mol L-1) at the optimized composition (10 wt% MgO). The effects of MgO loading and precursor concentration on the catalytic performance and resistance against poisoning of the catalyst by potassium (K) are investigated. The Ni-MgO-Al2O3 catalyst with 10 wt% MgO and the original precursor concentration (Ni: 1.2 mol L-1; Mg: 0.3 mol L-1; Al: 0.4 mol L-1) exhibits the highest CH4 conversion and resistance against K poisoning even at the extremely high gas space velocity (GHSV) of 1,512,000 h-1. Excellent SRM performance of the Ni-MgO-Al2O3 catalyst is attributed to strong metal (Ni) to alumina support interaction (SMSI) when magnesium oxide (MgO) is co-precipitated with the Ni-Al2O3. The enhanced interaction of the Ni with MgO-Al2O3 support is found to protect the active Ni species against K poisoning.

  18. Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    Alkaline electrolysis cells operated at 250 °C and 40 bar have shown to be able to convert electrical energy into hydrogen at very high efficiencies and power densities. Foam based gas diffusion electrodes and an immobilized electrolyte allow for reversible operation as electrolysis cell or fuel...... cell. In the present work we demonstrate the application of hydrophobic, porous, and electro-catalytically active gas diffusion electrodes. PTFE particles and silver nanowires as electro-catalysts were used in the gas diffusion electrodes. Impedance spectroscopy and cyclic voltammetry were performed...... to determine the cell characteristics. The thickness of the electrolyte matrix was only 200 µm, thereby achieving a serial resistance and area specific resistance of 60 mΩ cm2 and 150 mΩ cm2, respectively, at 200 °C and 20 bar. A new production method was developed to increase the cell size from lab scale (1...

  19. Urban diffusion problems

    International Nuclear Information System (INIS)

    Hanna, S.R.

    1976-01-01

    It is hoped that urban diffusion models of air pollutants can eventually confidently be used to make major decisions, such as in planning the layout of a new industrial park, determining the effects of a new highway on air quality, or estimating the results of a new automobile emissions exhaust system. The urban diffusion model itself should be able to account for point, line, and area sources, and the local aerodynamic effects of street canyons and building wakes. Removal or transformations due to dry or wet deposition and chemical reactions are often important. It would be best if the model included meteorological parameters such as wind speed and temperature as dependent variables, since these parameters vary significantly when air passes from rural surfaces over urban surfaces

  20. Diffused Religion and Prayer

    Directory of Open Access Journals (Sweden)

    Roberto Cipriani

    2011-06-01

    Full Text Available It is quite likely that the origins of prayer are to be found in ancient mourning and bereavement rites. Primeval ritual prayer was codified and handed down socially to become a deep-rooted feature of people’s cultural behavior, so much so, that it may surface again several years later, in the face of death, danger, need, even in the case of relapse from faith and religious practice. Modes of prayer depend on religious experience, on relations between personal prayer and political action, between prayer and forgiveness, and between prayer and approaches to religions. Various forms of prayer exist, from the covert-hidden to the overt-manifest kind. How can they be investigated? How can one, for instance, explore mental prayer? These issues regard the canon of diffused religion and, therefore, of diffused prayer.

  1. Magnetic diffuse scattering

    International Nuclear Information System (INIS)

    Cable, J.W.

    1987-01-01

    The diffuse scattering of neutrons from magnetic materials provides unique and important information regarding the spatial correlations of the atoms and the spins. Such measurements have been extensively applied to magnetically ordered systems, such as the ferromagnetic binary alloys, for which the observed correlations describe the magnetic moment fluctuations associated with local environment effects. With the advent of polarization analysis, these techniques are increasingly being applied to study disordered paramagnetic systems such as the spin-glasses and the diluted magnetic semiconductors. The spin-pair correlations obtained are essential in understanding the exchange interactions of such systems. In this paper, we describe recent neutron diffuse scattering results on the atom-pair and spin-pair correlations in some of these disordered magnetic systems. 56 refs

  2. Diffusion in heterogeneous lattices

    Czech Academy of Sciences Publication Activity Database

    Tarasenko, Alexander; Jastrabík, Lubomír

    2010-01-01

    Roč. 256, č. 17 (2010), s. 5137-5144 ISSN 0169-4332 R&D Projects: GA AV ČR KAN301370701; GA MŠk(CZ) 1M06002 Institutional research plan: CEZ:AV0Z10100522 Keywords : lattice- gas systems * diffusion * Monte Carlo simulations Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.795, year: 2010

  3. Diffusion bonding techniques

    International Nuclear Information System (INIS)

    Peters, R.D.

    1978-01-01

    The applications of diffusion bonding at the General Electric Neutron Devices Department are briefly discussed, with particular emphasis on the gold/gold or gold/indium joints made between metallized alumina ceramic parts in the vacuum switch tube and the crystal resonator programs. Fixtures which use the differential expansion of dissimilar metals are described and compared to one that uses hydraulic pressure to apply the necessary bonding force

  4. Enrichment by diffusion

    International Nuclear Information System (INIS)

    Mezin, M.

    1976-01-01

    The report presents an introduction to general basic principles of the gaseous diffusion process for the separation of uranium isotopes. Dealt with are: a) theoretical background and basic considerations of separation work and production costs, b) construction of a single separation stage and a multistage plant, c) the components of a plant and the optimization factors, d) cost factors. The text is illustrated by instructive diagrammes and flow charts. (RB) [de

  5. Temperature-dependent resistance switching in SrTiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jian-kun [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ma, Chao; Ge, Chen, E-mail: kjjin@iphy.ac.cn, E-mail: gechen@iphy.ac.cn; Gu, Lin; He, Xu; Zhou, Wen-jia; Lu, Hui-bin [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Jin, Kui-juan, E-mail: kjjin@iphy.ac.cn, E-mail: gechen@iphy.ac.cn [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100190 (China); Zhang, Qing-hua [School of Materials Science and Engineering, State Key Lab of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084 (China); Yang, Guo-zhen [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100190 (China)

    2016-06-13

    Resistance switching phenomena were studied by varying temperature in SrTiO{sub 3} single crystal. The resistance hysteresis loops appear at a certain temperature ranging from 340 K to 520 K. With the assistance of 375 nm ultraviolet continuous laser, the sample resistance is greatly reduced, leading to a stable effect than that in dark. These resistance switching phenomena only exist in samples with enough oxygen vacancies, which is confirmed by spherical aberration-corrected scanning transmission electron microscopy measurements, demonstrating an important role played by oxygen vacancies. At temperatures above 340 K, positively charged oxygen vacancies become mobile triggered by external electric field, and the resistance switching effect emerges. Our theoretical results based on drift-diffusion model reveal that the built-in field caused by oxygen vacancies can be altered under external electric field. Therefore, two resistance states are produced under the cooperative effect of built-in field and external field. However, the increasing mobility of oxygen vacancies caused by higher temperature promotes internal electric field to reach equilibrium states quickly, and suppresses the hysteresis loops above 420 K.

  6. Methicillin-resistant Staphylococcus sp. colonizing health care workers of a cancer hospital

    Science.gov (United States)

    Costa, Dayane de Melo; Kipnis, André; Leão-Vasconcelos, Lara Stefânia Netto de Oliveira; Rocha-Vilefort, Larissa Oliveira; Telles, Sheila Araújo; André, Maria Cláudia Dantas Porfírio Borges; Tipple, Anaclara Ferreira Veiga; Lima, Ana Beatriz Mori; Ribeiro, Nádia Ferreira Gonçalves; Pereira, Mayara Regina; Prado-Palos, Marinésia Aparecida

    2014-01-01

    The aim of the study was to analyze epidemiological and microbiological aspects of oral colonization by methicillin-resistant Staphylococcus of health care workers in a cancer hospital. Interview and saliva sampling were performed with 149 health care workers. Antimicrobial resistance was determined by disk diffusion and minimum inhibitory concentration. Polymerase Chain Reaction, Internal Transcribed Spacer-Polymerase Chain Reaction and Pulsed Field Gel Electrophoresis were performed for genotypic characterization of methicillin-resistant Staphylococcus. Risk factors were determined by logistic regression. Methicillin-resistant Staphylococcus colonization prevalence was 19.5%, denture wearing (p = 0.03), habit of nail biting (p = 0.04) and preparation and administration of antimicrobial (p = 0.04) were risk factors identified. All methicillin-resistant Staphylococcus were S. epidermidis, 94.4% of them had mecA gene. Closely related and indistinguishable methicillin-resistant S. epidermidis were detected. These results highlight that HCWs which have contact with patient at high risk for developing infections were identified as colonized by MRSE in the oral cavity, reinforcing this cavity as a reservoir of these bacteria and the risk to themselves and patients safety, because these microorganisms may be spread by coughing and talking. PMID:25477910

  7. Surface diffusion of sorbed radionuclides

    International Nuclear Information System (INIS)

    Berry, J.A.; Bond, K.A.

    1991-01-01

    Surface diffusion has in the past been invoked to explain rates of radionuclide migration which were greater than those predicted. Results were generally open to interpretation but the possible existence of surface diffusion, whereby sorbed radionuclides could potentially migrate at much enhanced rates, necessitated investigation. In this work through-diffusion experiments have shown that although surface diffusion does exist for some nuclides, the magnitude of the phenomenon is not sufficient to affect repository safety assessment modelling. (author)

  8. Effect of fly ash composition on the sulfate resistance of concrete[Includes the CSCE forum on professional practice and career development : 1. international engineering mechanics and materials specialty conference : 1. international/3. coastal, estuarine and offshore engineering specialty conference : 2. international/8. construction specialty conference

    Energy Technology Data Exchange (ETDEWEB)

    Dhole, R.D.; Thomas, M.D.A. [New Brunswick Univ., Fredericton, NB (Canada); Folliard, K.J.; Drimalas, T. [Texas Univ., Austin, TX (United States)

    2009-07-01

    Studies have shown that low-calcium Class F fly ashes obtained from burning coal in power stations can increase the sulfate resistance of Portland cement concrete. In many cases the sulfate resistance of concrete containing high-calcium Class C fly ash can be reduced compared to concrete without fly ash, due to the presence of crystalline C3A in the fly ash and calcium aluminate in the glass. This study investigated the differences in the glass composition and sulfate resistance of fly ashes with a range of calcium contents. The objective was to determine whether the behaviour of high-calcium fly ashes could be improved by blending with low-calcium fly ash. The sulfate resistance of cementitious systems consisting of a Type I Portland cement blended with Class F and Class C fly ashes of varying composition was evaluated by monitoring the length change of mortar bars stored in 5 per cent sodium sulfate solution. Scanning electron microscopy and electron dispersive X-ray analysis were used to characterize the glass phases of the fly ashes. The position occupied by the glass when plotted on a CaO-SiO{sub 2}-Al{sub 2}O{sub 3} ternary was identified as belonging to one of the fields occupied by the mineral phases mullite, anorthosite or gehlenite. The glass showed a transition from alumino-silicate in Class F fly ash to a calcium alumino-silicate or mixed calcium-aluminate/alumino-silicate in Class C fly ashes with higher calcium contents. Fly ashes with high amounts of calcium-aluminate glass had reduced sulfate resistance when tested in mortars. Blends of Class C and Class F fly ashes had better sulfate resistance than mixes made with only Class C fly ash. A relationship was established between the calcium oxide content of the blended fly ash and sulfate resistance of mortar. 8 refs., 5 tabs., 10 figs.

  9. Diffusion in cladding materials

    International Nuclear Information System (INIS)

    Anand, M.S.; Pande, B.M.; Agarwala, R.P.

    1992-01-01

    Aluminium has been used as a cladding material in most research reactors because its low neutron absorption cross section and ease of fabrication. However, it is not suitable for cladding in power reactors and as such zircaloy-2 is normally used as a clad because it can withstand high temperature. It has low neutron absorption cross section, good oxidation, corrosion, creep properties and possesses good mechanical strength. With the passage of time, further development in this branch of science took place and designers started looking for better neutron economy and less hydrogen pickup in PHW reactors. The motion of fission products in the cladding material could pose a problem after long operation. In order to understand their behaviour under reactor environment, it is essential to study first the diffusion under normal conditions. These studies will throw light on the interaction of defects with impurities which would in turn help in understanding the mechanism of diffusion. In this article, it is intended to discuss the diffusion behaviour of impurities in cladding materials.(i.e. aluminium, zircaloy-2, zirconium-niobium alloy etc.). (author). 94 refs., 4 figs., 3 tabs

  10. Diffusion properties of active particles with directional reversal

    International Nuclear Information System (INIS)

    Großmann, R; Bär, M; Peruani, F

    2016-01-01

    The diffusion properties of self-propelled particles which move at constant speed and, in addition, reverse their direction of motion repeatedly are investigated. The internal dynamics of particles triggering these reversal processes is modeled by a stochastic clock. The velocity correlation function as well as the mean squared displacement is investigated and, furthermore, a general expression for the diffusion coefficient for self-propelled particles with directional reversal is derived. Our analysis reveals the existence of an optimal, finite rotational noise amplitude which maximizes the diffusion coefficient. We comment on the relevance of these results with regard to biological systems and suggest further experiments in this context. (paper)

  11. Experimental study of chloride diffusivity in unsaturated ordinary Portland cement mortar

    NARCIS (Netherlands)

    Zhang, Y.; Ye, G.; Santhanam, M.

    2017-01-01

    Experiments are carried out to investigate the chloride diffusivity in partially saturated ordinary Portland cement mortars with water-to-cement (w/c) ratios of 0.4, 0.5 and 0.6. Based on resistivity measurement and Nernst-Einstein equation, the chloride diffusivities of cement mortars at various

  12. Solute diffusivity in undisturbed soil

    DEFF Research Database (Denmark)

    Lægdsmand, Mette; Møldrup, Per; Schjønning, Per

    2012-01-01

    Solute diffusivity in soil plays a major role in many important processes with relation to plant growth and environmental issues. Soil solute diffusivity is affected by the volumetric water content as well as the morphological characteristics of water-filled pores. The solute diffusivity in intact...

  13. Ultrasonic Examination of Jet Pump Diffuser Assemblies

    International Nuclear Information System (INIS)

    Hacker, M.; Levesque, M.; Whitman, G.

    1998-01-01

    In October 1997 the Boiling Water REactor Vessel and Internals Project (BWRVIP) issued the BWR Jet Pump Assembly Inspection and Flaw Evaluation Guidelines (BWRVIP-41). This document identified several welds on the jet pump diffuser assembly that are susceptible to Intergranular Stress Corrosion Cracking (IGSCC) or fatigue, and whose failure could result in jet pump disassembly. Based on the potential for failures, the document recommends inspection of 50% of the high priority welds at the next refueling outage for each BWR, with 100% expansion if flaws are identified. Because each diffuser assembly contains as many as six high priority welds, and access to these welds from the annulus is very restricted, implementing these recommendations can have a significant impact on outage critical path. In an effort to minimize the impact of implementing these recommendations, Framatome Technologies, Inc (FTI) developed a method to perform ultrasonic examinations of the jet pump diffuser assembly welds utilizing remotely operated equipment from the inner diameter (ID) of the diffuser assembly. This paper will discuss the tooling, ultrasonic methods, and delivery techniques used to perform the examinations, as well as the results obtained from a spring 1998 deployment of the system at a U.S. Nuclear Generating Plant. (Author)

  14. Low-level quinolone-resistance in multi-drug resistant typhoid

    Energy Technology Data Exchange (ETDEWEB)

    Mirza, S H; Khan, M A [Armed Forces Inst. of Pathology, Rawalpindi (Pakistan). Dept. of Microbiolgy

    2008-01-15

    To find out the frequency of low-level quinolone-resistance in Multi-Drug Resistant (MDR) typhoid using nalidixic acid screening disc. Blood was obtained from suspected cases of typhoid fever and cultured in to BacT/ALERT. The positive blood cultures bottles were subcultured. The isolates were identified by colony morphology and biochemical tests using API-20E galleries. Susceptibility testing of isolates was done by modified Kirby-Bauer disc diffusion method on Muellar Hinton Agar. For the isolates, which were resistant to nalidixic acid by disc diffusion method, Minimal Inhibitory Concentrations (MICs) of ciprofloxacin and nalidixic acid were determined by using the E-test strips. Disc diffusion susceptibility tests and MICs were interpreted according to the guidelines provided by National Committee for Control Laboratory Standard (NCCLS). A total of 21(65.5%) out of 32 isolates of Salmonellae were nalidixic acid-resistant by disk diffusion method. All the nalidixic acid-resistant isolates by disc diffusion method were confirmed by MICs for both ciprofloxacin and nalidixic acid. All the nalidixic acid-resistant isolates had a ciprofloxacin MIC of 0.25-1 microg/ml (reduced susceptibility) and nalidixic acid MICs > 32 microg (resistant). Out of all Salmonella isolates, 24 (75%) were found to be MDR, and all were S. typbi. Low-level quinolone-resistance in typhoid was high in this small series. Screening for nalidixic acid resistance with a 30 microg nalidixic acid disk is a reliable and cost-effective method to detect low-level fluoroquinolone resistance, especially in the developing countries. (author)

  15. Low-level quinolone-resistance in multi-drug resistant typhoid

    International Nuclear Information System (INIS)

    Mirza, S.H.; Khan, M.A.

    2008-01-01

    To find out the frequency of low-level quinolone-resistance in Multi-Drug Resistant (MDR) typhoid using nalidixic acid screening disc. Blood was obtained from suspected cases of typhoid fever and cultured in to BacT/ALERT. The positive blood cultures bottles were subcultured. The isolates were identified by colony morphology and biochemical tests using API-20E galleries. Susceptibility testing of isolates was done by modified Kirby-Bauer disc diffusion method on Muellar Hinton Agar. For the isolates, which were resistant to nalidixic acid by disc diffusion method, Minimal Inhibitory Concentrations (MICs) of ciprofloxacin and nalidixic acid were determined by using the E-test strips. Disc diffusion susceptibility tests and MICs were interpreted according to the guidelines provided by National Committee for Control Laboratory Standard (NCCLS). A total of 21(65.5%) out of 32 isolates of Salmonellae were nalidixic acid-resistant by disk diffusion method. All the nalidixic acid-resistant isolates by disc diffusion method were confirmed by MICs for both ciprofloxacin and nalidixic acid. All the nalidixic acid-resistant isolates had a ciprofloxacin MIC of 0.25-1 microg/ml (reduced susceptibility) and nalidixic acid MICs > 32 microg (resistant). Out of all Salmonella isolates, 24 (75%) were found to be MDR, and all were S. typbi. Low-level quinolone-resistance in typhoid was high in this small series. Screening for nalidixic acid resistance with a 30 microg nalidixic acid disk is a reliable and cost-effective method to detect low-level fluoroquinolone resistance, especially in the developing countries. (author)

  16. Diffusion of Zonal Variables Using Node-Centered Diffusion Solver

    Energy Technology Data Exchange (ETDEWEB)

    Yang, T B

    2007-08-06

    Tom Kaiser [1] has done some preliminary work to use the node-centered diffusion solver (originally developed by T. Palmer [2]) in Kull for diffusion of zonal variables such as electron temperature. To avoid numerical diffusion, Tom used a scheme developed by Shestakov et al. [3] and found their scheme could, in the vicinity of steep gradients, decouple nearest-neighbor zonal sub-meshes leading to 'alternating-zone' (red-black mode) errors. Tom extended their scheme to couple the sub-meshes with appropriate chosen artificial diffusion and thereby solved the 'alternating-zone' problem. Because the choice of the artificial diffusion coefficient could be very delicate, it is desirable to use a scheme that does not require the artificial diffusion but still able to avoid both numerical diffusion and the 'alternating-zone' problem. In this document we present such a scheme.

  17. Thermal diffusion in dilute nanofluids investigated by photothermal interferometry

    International Nuclear Information System (INIS)

    Philip, J; Nisha, M R

    2010-01-01

    We have carried out a theoretical analysis of the dependence of the particle mass fraction on the thermal diffusivity of dilute suspensions of nanoparticles in liquids (dilute nanofluids). The analysis takes in to account adsorption of an ordered layer of solvent molecules around the nanoparticles. It is found that thermal diffusivity decreases with mass fraction for sufficiently small particle sizes. Beyond a critical particle size thermal diffusivity begins to increase with mass fraction for the same system. The results have been verified experimentally by measuring the thermal diffusivity of dilute suspensions of TiO 2 nanoparticles dispersed in polyvinyl alcohol (PVA) medium. The effect is attributed to Kapitza resistance of thermal waves in the medium.

  18. Toward the existence of ultrafast diffusion paths in Cu with a gradient microstructure: Room temperature diffusion of Ni

    Science.gov (United States)

    Wang, Z. B.; Lu, K.; Wilde, G.; Divinski, S.

    2008-09-01

    Room temperature diffusion of Ni63 in Cu with a gradient microstructure prepared by surface mechanical attrition treatment (SMAT) was investigated by applying the radiotracer technique. The results reveal significant penetration of Ni into the nanostructured layer. The relevant diffusivity is higher than that along the conventional high-angle grain boundaries by about six orders of magnitude. This behavior is associated with a higher energy state of internal interfaces produced via plastic deformation. The diffusivity in the top surface layer is somewhat smaller than that in the subsurface layer. This fact is related to nanotwin formation in the former during SMAT.

  19. A critical overview of definitions and determination techniques of the internal resistance using lithium-ion, lead-acid, nickel metal-hydride batteries and electrochemical double-layer capacitors as examples

    Science.gov (United States)

    Piłatowicz, Grzegorz; Marongiu, Andrea; Drillkens, Julia; Sinhuber, Philipp; Sauer, Dirk Uwe

    2015-11-01

    The internal resistance (Ri) is one of the key parameters that determine the current state of electrochemical storage systems (ESS). It is crucial for estimating cranking capability in conventional cars, available power in modern hybrid and electric vehicles and for determining commonly used factors such as state-of-health (SoH) and state-of-function (SoF). However, ESS are complex and non-linear systems. Their Ri depends on many parameters such as current rate, temperature, SoH and state-of-charge (SoC). It is also a fact that no standardized methodologies exist and many different definitions and ways of Ri determination are being used. Nevertheless, in many cases authors are not aware of the consequences that occur when different Ri definitions are being used, such as possible misinterpretations, doubtful comparisons and false figures of merit. This paper focuses on an application-oriented separation between various Ri definitions and highlights the differences between them. The investigation was based on the following technologies: lead-acid, lithium-ion and nickel metal-hydride batteries as well as electrochemical double-layer capacitors. It is not the target of this paper to provide a standardized definition of Ri but to give researchers, engineers and manufacturers a possibility to understand what the term Ri means in their own work.

  20. DIREPI: Sistema para el cálculo a resistencia de recipientes sometidos a presión interna // DIREPI: System for the resistance calculation of recipients with internal pressure

    Directory of Open Access Journals (Sweden)

    L. S. Flores Bernal

    1999-07-01

    Full Text Available El trabajo muestra la confección de un software para el cálculo a resistencia de recipientes sometidos a presión interna y construidosde acero, aborda también las ventajas que reporta el tener automatizado la metodología de trabajo por la calidad de los resultadosfinales que se obtienen y la fiabilidad de los mismos, el sistema posee una salida gráfica por AutoCAD que permite obtener losplanos de taller de los componentes de los recipientes diseñados.Palabras claves: CADD, CAD, diseño, cálculo de recipientes._________________________________________________________________________________AbstractThe work shows the making of a software for the calculation to resistance of steel recipients with internal pressure, it also approachesthe advantages that reports having automated the work methodology, the system has a graphic result for AutoCAD that allows toobtain the blueprinters of the components of the designed recipients.Key words: CADD, AutoCAD, design, calculation of recipients.

  1. Particle diffusion in a spheromak

    International Nuclear Information System (INIS)

    Meyerhofer, D.D.; Levinton, F.M.; Yamada, M.

    1988-01-01

    The local carbon particle diffusion coefficient was measured in the Proto S-1/C spheromak using a test particle injection scheme. When the plasma was not in a force-free Taylor state, and when there were pressure gradients in the plasma, the particle diffusion was five times that predicted by Bohm and was consistent with collisional drift wave diffusion. The diffusion appears to be driven by correlations of the fluctuating electric field and density. During the decay phase of the discharge when the plasma was in the Taylor state, the diffusion coefficient of the carbon was classical. 23 refs., 4 figs

  2. Advanced diffusion processes and phenomena

    CERN Document Server

    Öchsner, Andreas; Belova, Irina

    2014-01-01

    This topical volume on Advanced Diffusion Processes and Phenomena addresses diffusion in a wider sense of not only mass diffusion but also heat diffusion in fluids and solids. Both diffusion phenomena play an important role in the characterization of engineering materials and corresponding structures. Understanding these different transport phenomena at many levels, from atomistic to macro, has therefore long attracted the attention of many researchers in materials science and engineering and related disciplines. The present topical volume captures a representative cross-section of some of the

  3. Measuring methods of matrix diffusion

    International Nuclear Information System (INIS)

    Muurinen, A.; Valkiainen, M.

    1988-03-01

    In Finland the spent nuclear fuel is planned to be disposed of at large depths in crystalline bedrock. The radionuclides which are dissolved in the groundwater may be able to diffuse into the micropores of the porous rock matrix and thus be withdrawn from the flowing water in the fractures. This phenomenon is called matrix diffusion. A review over matrix diffusion is presented in the study. The main interest is directed to the diffusion of non-sorbing species. The review covers diffusion experiments and measurements of porosity, pore size, specific surface area and water permeability

  4. Theory of resistivity-gradient-driven turbulence

    International Nuclear Information System (INIS)

    Garcia, L.; Carreras, B.A.; Diamond, P.H.; Callen, J.D.

    1984-10-01

    A theory of the nonlinear evolution and saturation of resistivity-driven turbulence, which evolves from linear rippling instabilities, is presented. The nonlinear saturation mechanism is identified both analytically and numerically. Saturation occurs when the turbulent diffusion of the resistivity is large enough so that dissipation due to parallel electron thermal conduction balances the nonlinearly modified resistivity gradient driving term. The levels of potential, resistivity, and density fluctuations at saturation are calculated. A combination of computational modeling and analytic treatment is used in this investigation

  5. An innovation resistance factor model

    Directory of Open Access Journals (Sweden)

    Siti Salwa Mohd Ishak

    2016-09-01

    Full Text Available The process and implementation strategy of information technology in construction is generally considered through the limiting prism of theoretical contexts generated from innovation diffusion and acceptance. This research argues that more attention should be given to understanding the positive effects of resistance. The study develops a theoretical framing for the Integrated Resistance Factor Model (IRFM. The framing uses a combination of diffusion of innovation theory, technology acceptance model and social network perspective. The model is tested to identify the most significant resistance factors using Partial Least Square (PLS technique. All constructs proposed in the model are found to be significant, valid and consistent with the theoretical framework. IRFM is shown to be an effective and appropriate model of user resistance factors. The most critical factors to influence technology resistance in the online project information management system (OPIMS context are: support from leaders and peers, complexity of the technology, compatibility with key work practices; and pre-trial of the technology before it is actually deployed. The study provides a new model for further research in technology innovation specific to the construction industry.

  6. Performances of diffusion kurtosis imaging and diffusion tensor imaging in detecting white matter abnormality in schizophrenia

    Directory of Open Access Journals (Sweden)

    Jiajia Zhu

    2015-01-01

    Full Text Available Diffusion kurtosis imaging (DKI is an extension of diffusion tensor imaging (DTI, exhibiting improved sensitivity and specificity in detecting developmental and pathological changes in neural tissues. However, little attention was paid to the performances of DKI and DTI in detecting white matter abnormality in schizophrenia. In this study, DKI and DTI were performed in 94 schizophrenia patients and 91 sex- and age-matched healthy controls. White matter integrity was assessed by fractional anisotropy (FA, mean diffusivity (MD, axial diffusivity (AD, radial diffusivity (RD, mean kurtosis (MK, axial kurtosis (AK and radial kurtosis (RK of DKI and FA, MD, AD and RD of DTI. Group differences in these parameters were compared using tract-based spatial statistics (TBSS (P  AK (20% > RK (3% and RD (37% > FA (24% > MD (21% for DKI, and RD (43% > FA (30% > MD (21% for DTI. DKI-derived diffusion parameters (RD, FA and MD were sensitive to detect abnormality in white matter regions (the corpus callosum and anterior limb of internal capsule with coherent fiber arrangement; however, the kurtosis parameters (MK and AK were sensitive to reveal abnormality in white matter regions (the juxtacortical white matter and corona radiata with complex fiber arrangement. In schizophrenia, the decreased AK suggests axonal damage; however, the increased RD indicates myelin impairment. These findings suggest that diffusion and kurtosis parameters could provide complementary information and they should be jointly used to reveal pathological changes in schizophrenia.

  7. Diffusion tensor imaging of the human calf: Variation of inter- and intramuscle-specific diffusion parameters.

    Science.gov (United States)

    Schlaffke, Lara; Rehmann, Robert; Froeling, Martijn; Kley, Rudolf; Tegenthoff, Martin; Vorgerd, Matthias; Schmidt-Wilcke, Tobias

    2017-10-01

    To investigate to what extent inter- and intramuscular variations of diffusion parameters of human calf muscles can be explained by age, gender, muscle location, and body mass index (BMI) in a specific age group (20-35 years). Whole calf muscles of 18 healthy volunteers were evaluated. Magnetic resonance imaging (MRI) was performed using a 3T scanner and a 16-channel Torso XL coil. Diffusion-weighted images were acquired to perform fiber tractography and diffusion tensor imaging (DTI) analysis for each muscle of both legs. Fiber tractography was used to separate seven lower leg muscles. Associations between DTI parameters and confounds were evaluated. All muscles were additionally separated in seven identical segments along the z-axis to evaluate intramuscular differences in diffusion parameters. Fractional anisotropy (FA) and mean diffusivity (MD) were obtained for each muscle with low standard deviations (SDs) (SD FA : 0.01-0.02; SD MD : 0.07-0.14(10 -3 )). We found significant differences in FA values of the tibialis anterior muscle (AT) and extensor digitorum longus (EDL) muscles between men and women for whole muscle FA (two-sample t-tests; AT: P = 0.0014; EDL: P = 0.0004). We showed significant intramuscular differences in diffusion parameters between adjacent segments in most calf muscles (P < 0.001). Whereas muscle insertions showed higher (SD 0.03-0.06) than muscle bellies (SD 0.01-0.03), no relationships between FA or MD with age or BMI were found. Inter- and intramuscular variations in diffusion parameters of the calf were shown, which are not related to age or BMI in this age group. Differences between muscle belly and insertion should be considered when interpreting datasets not including whole muscles. 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1137-1148. © 2017 International Society for Magnetic Resonance in Medicine.

  8. A diffusivity model for predicting VOC diffusion in porous building materials based on fractal theory.

    Science.gov (United States)

    Liu, Yanfeng; Zhou, Xiaojun; Wang, Dengjia; Song, Cong; Liu, Jiaping

    2015-12-15

    Most building materials are porous media, and the internal diffusion coefficients of such materials have an important influences on the emission characteristics of volatile organic compounds (VOCs). The pore structure of porous building materials has a significant impact on the diffusion coefficient. However, the complex structural characteristics bring great difficulties to the model development. The existing prediction models of the diffusion coefficient are flawed and need to be improved. Using scanning electron microscope (SEM) observations and mercury intrusion porosimetry (MIP) tests of typical porous building materials, this study developed a new diffusivity model: the multistage series-connection fractal capillary-bundle (MSFC) model. The model considers the variable-diameter capillaries formed by macropores connected in series as the main mass transfer paths, and the diameter distribution of the capillary bundles obeys a fractal power law in the cross section. In addition, the tortuosity of the macrocapillary segments with different diameters is obtained by the fractal theory. Mesopores serve as the connections between the macrocapillary segments rather than as the main mass transfer paths. The theoretical results obtained using the MSFC model yielded a highly accurate prediction of the diffusion coefficients and were in a good agreement with the VOC concentration measurements in the environmental test chamber. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Use and abuse of diffusion

    International Nuclear Information System (INIS)

    Kwiotek, A.; Grzywna, Z.J.

    2005-01-01

    Diffusion in a bounded region (or diffusive mass transport) can be seen from at least three platforms: - chemistry of he Fick's equation; - chemical engineering. To pose a particular problem we have to provide some additional conditions (initial conditions, boundary conditions and further). As we understood it in all cases diffusion is considered in an open region (in other words in one phase). Chemical engineering however brings an idea of 'diffusion' between phases. We claim that there isn't diffusion between phases. One can only consider mass transport between phases. Mass transport (or transfer in chemical engineering jargon) from one phase to another composes of: diffusion in first phase partition at an interface diffusion in second phase. (author)

  10. Multidrug-resistant tuberculosis

    Directory of Open Access Journals (Sweden)

    McNerney Ruth

    2008-01-01

    Full Text Available Abstract Background With almost 9 million new cases each year, tuberculosis remains one of the most feared diseases on the planet. Led by the STOP-TB Partnership and WHO, recent efforts to combat the disease have made considerable progress in a number of countries. However, the emergence of mutated strains of Mycobacterium tuberculosis that are resistant to the major anti-tuberculosis drugs poses a deadly threat to control efforts. Multidrug-resistant tuberculosis (MDR-TB has been reported in all regions of the world. More recently, extensively drug resistant-tuberculosis (XDR-TB that is also resistant to second line drugs has emerged in a number of countries. To ensure that adequate resources are allocated to prevent the emergence and spread of drug resistance it is important to understand the scale of the problem. In this article we propose that current methods of describing the epidemiology of drug resistant tuberculosis are not adequate for this purpose and argue for the inclusion of population based statistics in global surveillance data. Discussion Whereas the prevalence of tuberculosis is presented as the proportion of individuals within a defined population having disease, the prevalence of drug resistant tuberculosis is usually presented as the proportion of tuberculosis cases exhibiting resistance to anti-tuberculosis drugs. Global surveillance activities have identified countries in Eastern Europe, the former Soviet Union and regions of China as having a high proportion of MDR-TB cases and international commentary has focused primarily on the urgent need to improve control in these settings. Other regions, such as sub-Saharan Africa have been observed as having a low proportion of drug resistant cases. However, if one considers the incidence of new tuberculosis cases with drug resistant disease in terms of the population then countries of sub-Saharan Africa have amongst the highest rates of transmitted MDR-TB in the world. We propose

  11. CHANNELS AND DETERMINANTS OF TECHNOLOGY DIFFUSION

    Directory of Open Access Journals (Sweden)

    Jakub M. Kwiatkowski

    2015-09-01

    Full Text Available Potential for development of all countries of modern World is highly dependent on the ability to create and absorb technology. The following paper constitutes review of the literature focused on channels and factors that determine speed of this process between countries. The first part of the paper analyses three basic channels of technology diffu-sion: international trade, Foreign Direct Investments and networking. In the second part methology proposed by UNCTAD is utilized in order to systematize determinants of technology diffusion. Examined factors are divided into four groups: related to the nature of technology, seller of technology, buyer of technology and determinants associated with economic policy and society. The analysis allows to draw a number of conclusions and highlights need for further research.

  12. Diffusion in amorphous media

    Science.gov (United States)

    Iotov, Mihail S.

    The goals of this research are twofold: First, to develop methods and tools for studying problems in chemistry, material science and biology, as well as accurate prediction of the properties of structures and materials of importance to those fields. Second, use those tools to apply the methods to practical problems. In terms of methodology development this thesis focuses on two topics: One: Development of a massively parallel computer program to perform electronic, atomic, molecular levels simulations of problems in chemistry, material science and biology. This computer program uses existing and emerging hardware platforms and parallel tools and is based on decades long research in computer modeling and algorithms. We report on that development in Chapter 3. Two: Development of tools for Molecular Dynamics simulation and methods and tools for course-grained meso-scale modeling of transport properties and especially diffusion of gas penetrants in polymers. We have formulated a new method for extracting coarse-grained information from short (0.2-0.5 nanoseconds [ns]) MD simulations and use this in a meso-scale simulation to calculate diffusion constants in polymer matrices. This is a grid-based method, which calculates the average probability of each grid point of being a void and performs constrained and biased Monte Carlo (MC) dynamics to reach much longer time regimes than possible in MD. The MC method mimics the three regimes of mean square deviation (MSD) behavior seen in MD, thus accounting for the proper mobility of the voids and the compressibility of the polymer matrix. Theoretical discussions and justification for the method is presented in chapter 6. Initial results on He diffusion in a low-density polyethylene (PE) matrix are presented in chapter 7. The behavior at different temperatures follows closely the trend observed from calibrating long term MD for this particular system.

  13. Diffusion in silicon isotope heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Silvestri, Hughes Howland [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    The simultaneous diffusion of Si and the dopants B, P, and As has been studied by the use of a multilayer structure of isotopically enriched Si. This structure, consisting of 5 pairs of 120 nm thick natural Si and 28Si enriched layers, enables the observation of 30Si self-diffusion from the natural layers into the 28Si enriched layers, as well as dopant diffusion from an implanted source in an amorphous Si cap layer, via Secondary Ion Mass Spectrometry (SIMS). The dopant diffusion created regions of the multilayer structure that were extrinsic at the diffusion temperatures. In these regions, the Fermi level shift due to the extrinsic condition altered the concentration and charge state of the native defects involved in the diffusion process, which affected the dopant and self-diffusion. The simultaneously recorded diffusion profiles enabled the modeling of the coupled dopant and self-diffusion. From the modeling of the simultaneous diffusion, the dopant diffusion mechanisms, the native defect charge states, and the self- and dopant diffusion coefficients can be determined. This information is necessary to enhance the physical modeling of dopant diffusion in Si. It is of particular interest to the modeling of future electronic Si devices, where the nanometer-scale features have created the need for precise physical models of atomic diffusion in Si. The modeling of the experimental profiles of simultaneous diffusion of B and Si under p-type extrinsic conditions revealed that both species are mediated by neutral and singly, positively charged Si self-interstitials. The diffusion of As and Si under extrinsic n-type conditions yielded a model consisting of the interstitialcy and vacancy mechanisms of diffusion via singly negatively charged self-interstitials and neutral vacancies. The simultaneous diffusion of P and Si has been modeled on the basis of neutral and singly negatively charged self-interstitials and neutral and singly

  14. Planar Dirac diffusion

    International Nuclear Information System (INIS)

    Leo, Stefano de; Rotelli, Pietro

    2009-01-01

    We present the results of the planar diffusion of a Dirac particle by step and barrier potentials, when the incoming wave impinges at an arbitrary angle with the potential. Except for right-angle incidence this process is characterized by the appearance of spin flip terms. For the step potential, spin flip occurs for both transmitted and reflected waves. However, we find no spin flip in the transmitted barrier result. This is surprising because the barrier result may be derived directly from a two-step calculation. We demonstrate that the spin flip cancellation indeed occurs for each ''particle'' (wave packet) contribution. (orig.)

  15. Radon diffusion chamber

    International Nuclear Information System (INIS)

    Pretzsch, G.; Boerner, E.; Lehmann, R.; Sarenio, O.

    1986-01-01

    The invention relates to the detection of radioactive gases emitting alpha particles like radon, thoron and their alpha-decaying daughters by means of a diffusion chamber with a passive detector, preferably with a solid state track detector. In the chamber above and towards the detector there is a single metallized electret with negative polarity. The distance between electret and detector corresponds to the range of the alpha particles of radon daughters in air at the most. The electret collects the positively charged daughters and functions as surface source. The electret increases the sensitivity by the factor 4

  16. Diffuse esophageal spasm

    International Nuclear Information System (INIS)

    Ott, D.J.; Chen, Y.M.; Hewson, E.G.; Richter, J.E.; Wu, W.C.; Gelfand, D.W.; Castell, D.O.

    1988-01-01

    Radiologic and manometric findings were correlated in 17 patients with diffuse esophageal spasm (DES). All patients initially had chest pain and/or dysphagia and had a manometric diagnosis of DES. Mean percentage of normal peristalsis manometrically was 46% (range, 20%-80%). Based on radiologic examination, an esophageal motor disorder consistent with DES was diagnosed in 12 of 17 patients, and there was one misinterpretation of achalasia. Radiologic detection was not related significantly to the percentage of peristalsis seen on manometric examination. Mean esophageal wall thickness as measured radiographically in patients with DES was 2.6 mm, compared with 2.5 mm in 17 individuals with normal results of manometry

  17. Elemental diffusion in stars

    International Nuclear Information System (INIS)

    Michaud, Georges; Montmerle, Thierry

    1977-01-01

    This paper is dealing with the origin of the elements in the universe. The scheme of nucleosynthesis is kept to explain the stellar generation of helium, carbon, etc... from the initial hydrogen; but a nonlinear theory is then elaborated to account for the anomalous abundances which were observed. The chemical elements would diffuse throughout the outer layers of a star under the action of the opposite forces of gravitation and radiation. This theory, with completing the nucleosynthesis, would contribute to give a consistent scheme of the elemental origin and abundances [fr

  18. Oxygen transport in waterlogged soils, Part II. Diffusion coefficients

    International Nuclear Information System (INIS)

    Obando Moncayo, F.H.

    2004-01-01

    Several equations are available for Oxygen Transport in Waterlogged Soils and have been used for soils and plants. All of them are some form of first Fick's law as given by dQ = - DA(dc/dx)/dt. This equation illustrates some important aspects of aeration in waterlogged soils; first, D is a property of the medium and the gas, and is affected by temperature T. Likewise, the amount of diffusing substance dQ in dt is a direct function of the cross sectional area A and inversely proportional to the distance x. In fact, increasing the water content of air-dry soil, drastically decreases A and creates a further resistance for the flow of oxygen through water films around root plants, soil micro organisms and soil aggregates. The solid phase is also limiting the cross-section of surface of the free gaseous diffusion and the length and tortuosity of diffusion path in soil. In most of cases, soil gas porosity and tortuosity of soil voids are expressed in the equations of diffusion as a broad 'diffusion coefficient' (apparent coefficient diffusion). The process of soil respiration is complicated, involves many parameters, and is difficult to realistically quantify. With regard to the oxygen supply, it is convenient to distinguish macro and micro models, and hence, the flux of oxygen is assumed to have two steps. The first step is related to oxygen diffusion from the atmosphere and the air-filled porosity. The second step is related to the oxygen diffusion through water-films in and around plant roots, soil micro organisms and aggregates. Because of these models we obtain coefficients of macro or micro diffusion, rates of macro or micro diffusion, etc. In the macro diffusion process oxygen is transferred in the soil profile, mainly from the soil surface to a certain depth of the root zone, while micro diffusion deals with the flux over very short distances. Both processes, macro and micro diffusion are highly influenced by soil water content. Of course, if water is added to

  19. Resistant Hypertension.

    Science.gov (United States)

    Doroszko, Adrian; Janus, Agnieszka; Szahidewicz-Krupska, Ewa; Mazur, Grzegorz; Derkacz, Arkadiusz

    2016-01-01

    Resistant hypertension is a severe medical condition which is estimated to appear in 9-18% of hypertensive patients. Due to higher cardiovascular risk, this disorder requires special diagnosis and treatment. The heterogeneous etiology, risk factors and comorbidities of resistant hypertension stand in need of sophisticated evaluation to confirm the diagnosis and select the best therapeutic options, which should consider lifestyle modifications as well as pharmacological and interventional treatment. After having excluded pseudohypertension, inappropriate blood pressure measurement and control as well as the white coat effect, suspicion of resistant hypertension requires an analysis of drugs which the hypertensive patient is treated with. According to one definition - ineffective treatment with 3 or more antihypertensive drugs including diuretics makes it possible to diagnose resistant hypertension. A multidrug therapy including angiotensin - converting enzyme inhibitors, angiotensin II receptor blockers, beta blockers, diuretics, long-acting calcium channel blockers and mineralocorticoid receptor antagonists has been demonstrated to be effective in resistant hypertension treatment. Nevertheless, optional, innovative therapies, e.g. a renal denervation or baroreflex activation, may create a novel pathway of blood pressure lowering procedures. The right diagnosis of this disease needs to eliminate the secondary causes of resistant hypertension e.g. obstructive sleep apnea, atherosclerosis and renal or hormonal disorders. This paper briefly summarizes the identification of the causes of resistant hypertension and therapeutic strategies, which may contribute to the proper diagnosis and an improvement of the long term management of resistant hypertension.

  20. Camptothecin resistance

    DEFF Research Database (Denmark)

    Brangi, M; Litman, Thomas; Ciotti, M

    1999-01-01

    . Glucuronides were found at equal levels in both parental and resistant colon cancer cell lines for epirubicin and to a lesser extent for SN-38 and mitoxantrone. Low levels of glucuronidation could also be detected in the resistant breast cancer cells. These results were confirmed by analysis of the UGT1A...

  1. Evaluation of resistivity meters for concrete quality assurance.

    Science.gov (United States)

    2015-06-01

    This research evaluated a series of MoDOT concrete mixtures to verify existing relationships between surface resistivity (SR), rapid : chloride permeability (RCP), chloride ion diffusion, and the AASHTO penetrability classes. The research also perfor...

  2. Antibiotic Resistance

    DEFF Research Database (Denmark)

    Munck, Christian

    morbidity and mortality as well as an increase in the cost of treatment. Understanding how bacteria respond to antibiotic exposure gives the foundations for a rational approach to counteract antimicrobial resistance. In the work presented in this thesis, I explore the two fundamental sources...... of antimicrobial resistance: (1) adaptive mutations and (2) horizontal acquisition of resistance genes from antibiotic gene reservoirs. By studying the geno- and phenotypic changes of E. coli in response to single and drug-pair exposures, I uncover the evolutionary trajectories leading to adaptive resistance. I...... to rationally design drug combinations that limit the evolution of antibiotic resistance due to counteracting evolutionary trajectories. My results highlight that an in-depth knowledge about the genetic responses to the individual antimicrobial compounds enables the prediction of responses to drug combinations...

  3. The diffusion of H and D in Nb and Ta at low temperatures

    International Nuclear Information System (INIS)

    Engelhard, J.

    1978-01-01

    The mobility of hydrogen and deuterium in niobium and tantalum has been studied by quenching to 4.2 K and annealing between 10 K and 100 K. The concentration of quenched hydrogen has been computed from the resistivity increase after quenching. The decrease of the residual resistivity during annealing is interpreted by the trapping of hydrogen and by the formation of precipitations. By the variation of the hydrogen concentration and the impurity content, the annealing stage corresponding to the intrinsic diffusion of the hydrogen has been identified. Diffusion coefficients and activation energies for H and D diffusion in niobium and tantalum were determined. (orig./GSCH)

  4. Diffusion in Solids Fundamentals, Methods, Materials, Diffusion-Controlled Processes

    CERN Document Server

    Mehrer, Helmut

    2007-01-01

    Diffusion is a vital topic in solid-state physics and chemistry, physical metallurgy and materials science. Diffusion processes are ubiquitous in solids at elevated temperatures. A thorough understanding of diffusion in materials is crucial for materials development and engineering. This book first gives an account of the central aspects of diffusion in solids, for which the necessary background is a course in solid state physics. It then provides easy access to important information about diffuson in metals, alloys, semiconductors, ion-conducting materials, glasses and nanomaterials. Several diffusion-controlled phenomena, including ionic conduction, grain-boundary and dislocation pipe diffusion, are considered as well. Graduate students in solid-state physics, physical metallurgy, materials science, physical and inorganic chemistry or geophysics will benefit from this book as will physicists, chemists, metallurgists, materials engineers in academic and industrial research laboratories.

  5. Polymyxin susceptibility testing, interpretative breakpoints and resistance mechanisms: An update.

    Science.gov (United States)

    Bakthavatchalam, Yamuna Devi; Pragasam, Agila Kumari; Biswas, Indranil; Veeraraghavan, Balaji

    2018-03-01

    Emerging multidrug-resistant (MDR) nosocomial pathogens are a great threat. Polymyxins, an old class of cationic polypeptide antibiotic, are considered as last-resort drugs in treating infections caused by MDR Gram-negative bacteria. Increased use of polymyxins in treating critically ill patients necessitates routine polymyxin susceptibility testing. However, susceptibility testing both of colistin and polymyxin B (PMB) is challenging. In this review, currently available susceptibility testing methods are briefly discussed. The multicomponent composition of colistin and PMB significantly influences susceptibility testing. In addition, poor diffusion in the agar medium, adsorption to microtitre plates and the synergistic effect of the surfactant polysorbate 80 with polymyxins have a great impact on the performance of susceptibility testing methods This review also describes recently identified chromosomal resistance mechanisms, including modification of lipopolysaccharide (LPS) with 4-amino-4-deoxy-l-arabinose (L-Ara4-N) and phosphoethanolamine (pEtN) resulting in alteration of the negative charge, as well as the plasmid-mediated colistin resistance determinants mcr-1, mcr-1.2, mcr-2 and mcr-3. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  6. Apparatus for diffusion separation

    International Nuclear Information System (INIS)

    Nierenberg, W.A.

    1976-01-01

    A diffuser separator apparatus is described which comprises a plurality of flow channels in a single stage. Each of said channels has an inlet port and an outlet port and a constant cross sectional area between said ports. At least a portion of the defining surface of each of said channels is a diffusion separation membrane, and each of said channels is a different cross sectional area. Means are provided for connecting said channels in series so that each successive channel of said series has a smaller cross sectional area than the previous channel of said series. Also provided are a source of gaseous mixture, individual means for flowing said gaseous mixture to the inlet port of each of said channels, gas receiving and analyzing means, individual means for flowing gas passing from each of said outlet ports and means for flowing gas passing through said membranes to said receiving and analyzing means, and individual means for connecting the outlet port of each channel with the inlet port of the channel having the next smaller cross sectional area

  7. The diffusion of microfinance.

    Science.gov (United States)

    Banerjee, Abhijit; Chandrasekhar, Arun G; Duflo, Esther; Jackson, Matthew O

    2013-07-26

    To study the impact of the choice of injection points in the diffusion of a new product in a society, we developed a model of word-of-mouth diffusion and then applied it to data on social networks and participation in a newly available microfinance loan program in 43 Indian villages. Our model allows us to distinguish information passing among neighbors from direct influence of neighbors' participation decisions, as well as information passing by participants versus nonparticipants. The model estimates suggest that participants are seven times as likely to pass information compared to informed nonparticipants, but information passed by nonparticipants still accounts for roughly one-third of eventual participation. An informed household is not more likely to participate if its informed friends participate. We then propose two new measures of how effective a given household would be as an injection point. We show that the centrality of the injection points according to these measures constitutes a strong and significant predictor of eventual village-level participation.

  8. Diffuse infiltrative lung disease

    International Nuclear Information System (INIS)

    Niden, A.H.; Mishkin, F.S.

    1984-01-01

    The authors discuss their approach to the diagnosis and management of patients with DILD. Gallium scans play a central role in this process. Not only do they help them decide whom to biopsy, but also where to biopsy. The scans can be used for the early detection of disease in a high-risk population, for following the progression and regression of disease, for the regulation of medication, and for the evaluation of therapy. Bronchoalveolar lung lavage appears to be equally sensitive. However, patients are less willing to undergo repeated fiberoptic bronchoscopies than lung scans. Both tests may prove useful, one complementing the other. Gallium imaging has also been utilized by the authors in select patients with questionable diffuse lung infiltrates roentgenographically or with a normal chest roentgenogram, chronic respiratory symptoms, and abnormal pulmonary function studies. An abnormal gallium lung scan in these clinical situations helps them select which patients have a diffuse active pulmonary process meriting transbronchial biopsies. This has proven to be of particular value in the management of older patients

  9. Internal Tandem Duplication in FLT3 Attenuates Proliferation and Regulates Resistance to the FLT3 Inhibitor AC220 by Modulating p21Cdkn1a and Pbx1 in Hematopoietic Cells.

    Directory of Open Access Journals (Sweden)

    Mariko Abe

    Full Text Available Internal tandem duplication (ITD mutations in the Fms-related tyrosine kinase 3 (FLT3 gene (FLT3-ITD are associated with poor prognosis in patients with acute myeloid leukemia (AML. Due to the development of drug resistance, few FLT3-ITD inhibitors are effective against FLT3-ITD+ AML. In this study, we show that FLT3-ITD activates a novel pathway involving p21Cdkn1a (p21 and pre-B cell leukemia transcription factor 1 (Pbx1 that attenuates FLT3-ITD cell proliferation and is involved in the development of drug resistance. FLT3-ITD up-regulated p21 expression in both mouse bone marrow c-kit+-Sca-1+-Lin- (KSL cells and Ba/F3 cells. The loss of p21 expression enhanced growth factor-independent proliferation and sensitivity to cytarabine as a consequence of concomitantly enriching the S+G2/M phase population and significantly increasing the expression of Pbx1, but not Evi-1, in FLT3-ITD+ cells. This enhanced cell proliferation following the loss of p21 was partially abrogated when Pbx1 expression was silenced in FLT3-ITD+ primary bone marrow colony-forming cells and Ba/F3 cells. When FLT3-ITD was antagonized with AC220, a selective inhibitor of FLT3-ITD, p21 expression was decreased coincident with Pbx1 mRNA up-regulation and a rapid decline in the number of viable FLT3-ITD+ Ba/F3 cells; however, the cells eventually became refractory to AC220. Overexpressing p21 in FLT3-ITD+ Ba/F3 cells delayed the emergence of cells that were refractory to AC220, whereas p21 silencing accelerated their development. These data indicate that FLT3-ITD is capable of inhibiting FLT3-ITD+ cell proliferation through the p21/Pbx1 axis and that treatments that antagonize FLT3-ITD contribute to the subsequent development of cells that are refractory to a FLT3-ITD inhibitor by disrupting p21 expression.

  10. Long-term performance of activated carbon air cathodes with different diffusion layer porosities in microbial fuel cells

    KAUST Repository

    Zhang, Fang

    2011-08-01

    Activated carbon (AC) air-cathodes are inexpensive and useful alternatives to Pt-catalyzed electrodes in microbial fuel cells (MFCs), but information is needed on their long-term stability for oxygen reduction. AC cathodes were constructed with diffusion layers (DLs) with two different porosities (30% and 70%) to evaluate the effects of increased oxygen transfer on power. The 70% DL cathode initially produced a maximum power density of 1214±123mW/m 2 (cathode projected surface area; 35±4W/m 3 based on liquid volume), but it decreased by 40% after 1 year to 734±18mW/m 2. The 30% DL cathode initially produced less power than the 70% DL cathode, but it only decreased by 22% after 1 year (from 1014±2mW/m 2 to 789±68mW/m 2). Electrochemical tests were used to examine the reasons for the degraded performance. Diffusion resistance in the cathode was found to be the primary component of the internal resistance, and it increased over time. Replacing the cathode after 1 year completely restored the original power densities. These results suggest that the degradation in cathode performance was due to clogging of the AC micropores. These findings show that AC is a cost-effective material for oxygen reduction that can still produce ~750mW/m 2 after 1 year. © 2011 Elsevier B.V.

  11. Corrosion resistant coatings suitable for elevated temperature application

    Science.gov (United States)

    Chan, Kwai S [San Antonio, TX; Cheruvu, Narayana Sastry [San Antonio, TX; Liang, Wuwei [Austin, TX

    2012-07-31

    The present invention relates to corrosion resistance coatings suitable for elevated temperature applications, which employ compositions of iron (Fe), chromium (Cr), nickel (Ni) and/or aluminum (Al). The compositions may be configured to regulate the diffusion of metals between a coating and a substrate, which may then influence coating performance, via the formation of an inter-diffusion barrier layer. The inter-diffusion barrier layer may comprise a face-centered cubic phase.

  12. Hydraulic resistance of biofilms

    KAUST Repository

    Dreszer, C.

    2013-02-01

    Biofilms may interfere with membrane performance in at least three ways: (i) increase of the transmembrane pressure drop, (ii) increase of feed channel (feed-concentrate) pressure drop, and (iii) increase of transmembrane passage. Given the relevance of biofouling, it is surprising how few data exist about the hydraulic resistance of biofilms that may affect the transmembrane pressure drop and membrane passage. In this study, biofilms were generated in a lab scale cross flow microfiltration system at two fluxes (20 and 100Lm-2h-1) and constant cross flow (0.1ms-1). As a nutrient source, acetate was added (1.0mgL-1 acetate C) besides a control without nutrient supply. A microfiltration (MF) membrane was chosen because the MF membrane resistance is very low compared to the expected biofilm resistance and, thus, biofilm resistance can be determined accurately. Transmembrane pressure drop was monitored. As biofilm parameters, thickness, total cell number, TOC, and extracellular polymeric substances (EPS) were determined, it was demonstrated that no internal membrane fouling occurred and that the fouling layer actually consisted of a grown biofilm and was not a filter cake of accumulated bacterial cells. At 20Lm-2h-1 flux with a nutrient dosage of 1mgL-1 acetate C, the resistance after 4 days reached a value of 6×1012m-1. At 100Lm-2h-1 flux under the same conditions, the resistance was 5×1013m-1. No correlation of biofilm resistance to biofilm thickness was found; Biofilms with similar thickness could have different resistance depending on the applied flux. The cell number in biofilms was between 4×107 and 5×108 cellscm-2. At this number, bacterial cells make up less than a half percent of the overall biofilm volume and therefore did not hamper the water flow through the biofilm significantly. A flux of 100Lm-2h-1 with nutrient supply caused higher cell numbers, more biomass, and higher biofilm resistance than a flux of 20Lm-2h-1. However, the biofilm thickness

  13. Effect of Various Inoculum Levels of Multidrug-Resistant Salmonella enterica Serovar Heidelberg (2011 Ground Turkey Outbreak Isolate on Cecal Colonization, Dissemination to Internal Organs, and Deposition in Skeletal Muscles of Commercial Turkeys after Experimental Oral Challenge

    Directory of Open Access Journals (Sweden)

    Divek V. T. Nair

    2018-01-01

    Full Text Available Salmonella enterica serovar Heidelberg (S. Heidelberg is a major foodborne pathogen colonizing poultry. The pathogen is associated with a significant number of foodborne outbreaks through contaminated poultry meat, including turkeys. Recently, multidrug-resistant (MDR strains of S. Heidelberg have emerged as a threat to human public health in the United States. The objective of this study was to determine the cecal colonization, dissemination to internal organs, and the potential for skeletal muscle deposition of an MDR S. Heidelberg isolate from the 2011 ground turkey outbreak in the United States after the experimental oral challenge of poults (young turkeys and adult turkey hens. In the poult study, two separate experiments using day-old, straight-run, commercial hybrid converter poults were randomly assigned to five challenge groups (0, 10∧2, 10∧4, 10∧6, 10∧8 CFU groups; 12 poults/group; N = 60/experiment and a week after, treatment groups were challenged separately with 0-, 2-, 4-, 6-, and 8- log10 CFU of S. Heidelberg orally. After 14 days post-challenge, the poults were euthanized, and samples were collected to determine MDR S. Heidelberg colonization in the cecum, dissemination to liver and spleen, and deposition in the thigh, drumstick, and breast muscles. A similar experimental design was followed for the adult turkey hens. In two separate experiments, 11-week-old commercial Hybrid Converter turkey hens (4 hens/group; N = 20/experiment were challenged with MDR S. Heidelberg and on day 16 post-challenge, birds were euthanized and samples were collected to determine Salmonella populations in the samples. The results indicated that, in turkey poults, the recovery of MDR S. Heidelberg was highest in the cecum followed by spleen, liver, thigh, drumstick, and breast. All tested inoculum levels resulted in more than 3.5 log10 CFU/g colonization in the poult cecum. The cecal colonization, dissemination to internal organs, and tissue

  14. Clinical application of diffusion-weighted magnetic resonance imaging to intracranial disorders

    Energy Technology Data Exchange (ETDEWEB)

    Yanaka, Kiyoyuki; Shirai, Shizuo; Kimura, Hiroshi [Soujinkai Hospital, Ibaraki (Japan); Kamezaki, Takao; Matsumura, Akira; Nose, Tadao

    1995-09-01

    Diffusion-weighted magnetic resonance imaging was performed to determine the changes in water diffusion and to investigate the detectability of diffusion anisotropy in patients with intracranial disorders. Diffusion maps of the apparent diffusion coefficient (ADC) were created of 19 patients with cerebral infarction, five with intracerebral hematoma, four with glioma, four with meningioma, four with hydrocephalus, and five with subdural hematoma. ADC was increased in chronic cerebral infarction and glioma, and decreased in acute cerebral infarction, meningioma, and the marginal area of glioma compared with the ADC of the normal gray matter. There was a significant difference in ADC between the marginal and internal areas of glioma. Increased ADC may be due to increased vasogenic edema in infarction and a lack of significant restriction of diffusion within glioma. Decreased ADC can be attributed to restricted diffusion caused by cytotoxic edema in infarction and the underlying histological pattern of densely packed tumor cells in glioma. Diffusion anisotropy of the internal capsule was less detectable in pathological than normal hemispheres. Diffusion anisotropy was less detectable in patients with hydrocephalus and subdural hematoma. Intracranial lesions were thought to have influenced the compression of the brain structures and cells, resulting in decreased diffusion. The measurement of ADC by diffusion-weighted magnetic resonance imaging has the potential for greater understanding of the biophysical changes in various intracranial disorders, including correct diagnosis of cerebral infarction, and histological diagnosis of brain tumor. (author).

  15. 1/f noise: diffusive systems and music

    Energy Technology Data Exchange (ETDEWEB)

    Voss, R.F.

    1975-11-01

    Measurements of the 1/f voltage noise in continuous metal films are reported. At room temperature, samples of pure metals and bismuth (with a carrier density smaller by 10/sup 5/) of similar volume had comparable noise. The results suggest that the noise arises from equilibrium temperature fluctuations modulating the resistance. Spatial correlation of the noise implied that the fluctuations obey a diffusion equation. The empirical inclusion of an explicit 1/f region and appropriate normalization lead to excellent agreement with the measured noise. If the fluctuations are assumed to be spatially correlated, the diffusion equation can yield an extended 1/f region in the power spectrum. The temperature response of a sample to delta and step function power inputs is shown to have the same shape as the autocorrelation function for uncorrelated and correlated temperature fluctuations, respectively. The spectrum obtained from the cosine transform of the measured step function response is in excellent agreement with the measured 1/f voltage noise spectrum. Spatially correlated equilibrium temperature fluctuations are not the dominant source of 1/f noise in semiconductors and metal films. However, the agreement between the low-frequency spectrum of fluctuations in the mean-square Johnson noise voltage and the resistance fluctuation spectrum measured in the presence of a current demonstrates that in these systems the 1/f noise is also due to equilibrium resistance fluctuations. Loudness fluctuations in music and speech and pitch fluctuations in music also show the 1/f behavior. 1/f noise sources, consequently, are demonstrated to be the natural choice for stochastic composition. 26 figures, 1 table. (auth)

  16. Confinement and diffusion in tokamaks

    International Nuclear Information System (INIS)

    McWilliams, R.

    1988-01-01

    The effect of electric field fluctuations on confinement and diffusion in tokamak is discussed. Based on the experimentally determined cross-field turbolent diffusion coefficient, D∼3.7*cT e /eB(δn i /n i ) rms which is also derived by a simple theory, the cross-field diffusion time, tp=a 2 /D, is calculated and compared to experimental results from 51 tokamak for standard Ohmic operation

  17. Diffuse scattering of neutrons

    International Nuclear Information System (INIS)

    Novion, C.H. de.

    1981-02-01

    The use of neutron scattering to study atomic disorder in metals and alloys is described. The diffuse elastic scattering of neutrons by a perfect crystal lattice leads to a diffraction spectrum with only Bragg spreads. the existence of disorder in the crystal results in intensity and position modifications to these spreads, and above all, to the appearance of a low intensity scatter between Bragg peaks. The elastic scattering of neutrons is treated in this text, i.e. by measuring the number of scattered neutrons having the same energy as the incident neutrons. Such measurements yield information on the static disorder in the crystal and time average fluctuations in composition and atomic displacements [fr

  18. On Diffusive Climatological Models.

    Science.gov (United States)

    Griffel, D. H.; Drazin, P. G.

    1981-11-01

    A simple, zonally and annually averaged, energy-balance climatological model with diffusive heat transport and nonlinear albedo feedback is solved numerically. Some parameters of the model are varied, one by one, to find the resultant effects on the steady solution representing the climate. In particular, the outward radiation flux, the insulation distribution and the albedo parameterization are varied. We have found an accurate yet simple analytic expression for the mean annual insolation as a function of latitude and the obliquity of the Earth's rotation axis; this has enabled us to consider the effects of the oscillation of the obliquity. We have used a continuous albedo function which fits the observed values; it considerably reduces the sensitivity of the model. Climatic cycles, calculated by solving the time-dependent equation when parameters change slowly and periodically, are compared qualitatively with paleoclimatic records.

  19. Diffuse parenchymal lung disease

    Directory of Open Access Journals (Sweden)

    Sara Tomassetti

    2017-04-01

    Full Text Available Between September 2015 and August 2016 there were >1500 publications in the field of diffuse parenchymal lung diseases (DPLDs. For the Clinical Year in Review session at the European Respiratory Society Congress that was held in London, UK, in September 2016, we selected only five articles. This selection, made from the enormous number of published papers, does not include all the relevant studies that will significantly impact our knowledge in the field of DPLDs in the near future. This review article provides our personal view on the following topics: early diagnosis of idiopathic pulmonary fibrosis, current knowledge on the multidisciplinary team diagnosis of DPLDs and the diagnostic role of transbronchial cryobiopsy in this diagnostic setting, insights on the new entity of interstitial pneumonia with autoimmune features, and new therapeutic approaches for scleroderma-related interstitial lung disease.

  20. Convergence of Nelson diffusions

    International Nuclear Information System (INIS)

    Dell'Antonio, G.; Posilicano, A.

    1991-01-01

    Let ψ t , ψ t n , n≥1, be solutions of Schroedinger equations with potentials form-bounded by -1/2 Δ and initial data in H 1 (R d ). Let P, P n , n≥1, be the probability measures on the path space Ω=C(R + , R d ) given by the corresponding Nelson diffusions. We show that if {ψ t n } n≥1 converges to ψ t in H 2 (R d ), uniformly in t over compact intervals, then {P n } n≥1 converges to P in total variation. Moreover, if the potentials are in the Kato class K d , we show that the above result follows from H 1 -convergence of initial data, and K d -convergence of potentials. (orig.)

  1. Hereditary diffuse gastric cancer

    DEFF Research Database (Denmark)

    van der Post, Rachel S; Vogelaar, Ingrid P; Carneiro, Fátima

    2015-01-01

    Germline CDH1 mutations confer a high lifetime risk of developing diffuse gastric (DGC) and lobular breast cancer (LBC). A multidisciplinary workshop was organised to discuss genetic testing, surgery, surveillance strategies, pathology reporting and the patient's perspective on multiple aspects......, including diet post gastrectomy. The updated guidelines include revised CDH1 testing criteria (taking into account first-degree and second-degree relatives): (1) families with two or more patients with gastric cancer at any age, one confirmed DGC; (2) individuals with DGC before the age of 40 and (3...... the high mortality associated with invasive disease, prophylactic total gastrectomy at a centre of expertise is advised for individuals with pathogenic CDH1 mutations. Breast cancer surveillance with annual breast MRI starting at age 30 for women with a CDH1 mutation is recommended. Standardised endoscopic...

  2. The diffuse interstellar medium

    Science.gov (United States)

    Cox, Donald P.

    1990-01-01

    The last 20 years of the efforts to understand the diffuse ISM are reviewed, with recent changes of fundamental aspects being highlighted. Attention is given to the interstellar pressure and its components, the weight of the ISM, the midplane pressure contributions, and pressure contributions at 1 kpc. What velocity dispersions, cosmic ray pressure, and magnetic field pressure that can be expected for a gas in a high magnetic field environment is addressed. The intercloud medium is described, with reference to the work of Cox and Slavin (1989). Various caveats are discussed and a number of areas for future investigation are identified. Steps that could be taken toward a successful phase segregation model are discussed.

  3. Nonlocal diffusion and applications

    CERN Document Server

    Bucur, Claudia

    2016-01-01

    Working in the fractional Laplace framework, this book provides models and theorems related to nonlocal diffusion phenomena. In addition to a simple probabilistic interpretation, some applications to water waves, crystal dislocations, nonlocal phase transitions, nonlocal minimal surfaces and Schrödinger equations are given. Furthermore, an example of an s-harmonic function, its harmonic extension and some insight into a fractional version of a classical conjecture due to De Giorgi are presented. Although the aim is primarily to gather some introductory material concerning applications of the fractional Laplacian, some of the proofs and results are new. The work is entirely self-contained, and readers who wish to pursue related subjects of interest are invited to consult the rich bibliography for guidance.

  4. Diffusion rates for elevated releases

    International Nuclear Information System (INIS)

    Ramsdell, J.V.

    1983-11-01

    A search of the literature related to diffusion from elevated sources has determined that an adequate data base exists for use in developing parameterizations for estimating diffusion rates for material released from free standing stacks at nuclear power plants. A review of published data analyses indicates that a new parameterization of horizontal diffusion rates specifically for elevated releases is not likely to significantly change the magnitudes of horizontal diffusion coefficients on the average. However, the uncertainties associated with horizontal diffusion coefficient estimates under any given set of atmospheric conditions could be reduced by a new parameterization. Similarly, a new parameterization of vertical diffusion rates would be unlikely to significantly alter the magnitudes of diffusion coefficients for unstable atmospheric conditons. However, for neutral and stable atmospheric conditions, a new parameterization of vertical diffusion rates might increase vertical diffusion coefficients significantly. The increase would move ground-level time-integrated concentration maxima closer to the plant and would increase the maxima. 55 references, 2 figures, 4 tables

  5. Diffuse scattering in Ih ice

    International Nuclear Information System (INIS)

    Wehinger, Björn; Krisch, Michael; Bosak, Alexeï; Chernyshov, Dmitry; Bulat, Sergey; Ezhov, Victor

    2014-01-01

    Single crystals of ice Ih, extracted from the subglacial Lake Vostok accretion ice layer (3621 m depth) were investigated by means of diffuse x-ray scattering and inelastic x-ray scattering. The diffuse scattering was identified as mainly inelastic and rationalized in the frame of ab initio calculations for the ordered ice XI approximant. Together with Monte-Carlo modelling, our data allowed reconsidering previously available neutron diffuse scattering data of heavy ice as the sum of thermal diffuse scattering and static disorder contribution. (paper)

  6. Diffusion of condenser water discharge

    International Nuclear Information System (INIS)

    Iwakiri, Toshio

    1977-01-01

    Thermal and nuclear power stations in Japan are mostly located in coastal area, and the cooling water is discharged into sea as warm water. Recently, large interest is taken in this matter, and it is desirable to predict the diffusion of warm discharge accurately and to take effective measures for lowering the temperature. As for the methods of predicting the diffusion of warm discharge, simplified estimation, mathematical analysis and hydrographical model experiment are used corresponding to objects and conditions. As for the measures to lower temperature, the method of discharging warm water into deep sea bottom was confirmed to be very effective. In this paper, the phenomena of diffusion of warm discharge in sea, the methods of predicting the diffusion of warm discharge, and the deep sea discharge as the measure for lowering temperature are outlined. The factors concerning the diffusion of warm discharge in sea are the conditions of discharge, topography and sea state, and the diffusion is roughly divided into mixing diffusion in the vicinity of warm water outlet and eddy diffusion in distant region. It is difficult to change artificially the conditions of diffusion in distant region, and the measures of raising the rate of dilution in near region are effective, therefore the deep sea discharge is adopted. (Kako, I.)

  7. Diffusion effects in undulator radiation

    Directory of Open Access Journals (Sweden)

    Ilya Agapov

    2014-11-01

    Full Text Available Quantum diffusion effects in undulator radiation in semiclassical approximation are considered. Short-term effects on the electron beam motion are discussed and it is shown that approaches based on diffusion approximation with drift-diffusion coefficients derived from undulator or bending magnet radiation spectrum, and on Poisson statistics with radiation spectrum defined by the local beding field, all lead to similar results in terms of electron energy spread for cases of practical interest. An analytical estimate of the influence of quantum diffusion on the undulator radiation spectrum is derived.

  8. Sodium diffusion in boroaluminosilicate glasses

    DEFF Research Database (Denmark)

    Smedskjaer, Morten M.; Zheng, Qiuju; Mauro, John C.

    2011-01-01

    of isothermal sodium diffusion in BAS glasses by ion exchange, inward diffusion, and tracer diffusion experiments. By varying the [SiO2]/[Al2O3] ratio of the glasses, different structural regimes of sodium behavior are accessed. We show that the mobility of the sodium ions decreases with increasing [SiO2]/[Al2O......Understanding the fundamentals of alkali diffusion in boroaluminosilicate (BAS) glasses is of critical importance for advanced glass applications, e.g., the production of chemically strengthened glass covers for personal electronic devices. Here, we investigate the composition dependence...

  9. Antimicrobial Resistance

    Science.gov (United States)

    ... past two decades due to the increase in immunocompromised and elderly patients, increasing use of invasive indwelling ... aureus developing resistance to vancomycin, a very powerful antibiotic prescribed for the most intractable bacterial infections. In ...

  10. Drug Resistance

    Science.gov (United States)

    ... Drug-resistance testing is also recommended for all pregnant women with HIV before starting HIV medicines and also in some pregnant women already taking HIV medicines. Pregnant women will work with their health ...

  11. Diffusion-weighted MRI of maple syrup urine disease encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Cavalleri, F.; Mavilla, L. [Servizio di Neuroradiologia, Azienda Ospedaliera Policlinico, Modena (Italy); Berardi, A.; Ferrari, F. [Servizio di Neonatologia, Azienda Ospedaliera Policlinico, Modena (Italy); Burlina, A.B. [Dipartimento di Pediatria, Azienda Ospedaliera, Universita di Padova, Padua (Italy)

    2002-06-01

    We report the case of a newborn child with maple syrup urine disease (MSUD), diagnosed at 10 days of life. Diffusion-weighted echoplanar MRI showed marked hyperintensity of the cerebellar white matter, the brainstem, the cerebral peduncles, the thalami, the dorsal limb of the internal capsule and the centrum semiovale, while conventional dual-echo sequence evidenced only a weak diffuse T2 hyperintensity in the cerebellar white matter and in the dorsal brainstem. The apparent diffusion coefficient (ADC) of these regions was markedly (>80%) decreased. Therefore, in agreement with current hypotheses on MSUD pathogenesis, MSUD oedema proves to be a cytotoxic oedema. Diffusion-weighted MRI may be a valuable tool, more sensitive than conventional spin-echo techniques, to assess the extent and progression of cytotoxicity in MSUD, as well as the effectiveness of the therapeutic interventions. (orig.)

  12. Diffusion-weighted MRI of maple syrup urine disease encephalopathy

    International Nuclear Information System (INIS)

    Cavalleri, F.; Mavilla, L.; Berardi, A.; Ferrari, F.; Burlina, A.B.

    2002-01-01

    We report the case of a newborn child with maple syrup urine disease (MSUD), diagnosed at 10 days of life. Diffusion-weighted echoplanar MRI showed marked hyperintensity of the cerebellar white matter, the brainstem, the cerebral peduncles, the thalami, the dorsal limb of the internal capsule and the centrum semiovale, while conventional dual-echo sequence evidenced only a weak diffuse T2 hyperintensity in the cerebellar white matter and in the dorsal brainstem. The apparent diffusion coefficient (ADC) of these regions was markedly (>80%) decreased. Therefore, in agreement with current hypotheses on MSUD pathogenesis, MSUD oedema proves to be a cytotoxic oedema. Diffusion-weighted MRI may be a valuable tool, more sensitive than conventional spin-echo techniques, to assess the extent and progression of cytotoxicity in MSUD, as well as the effectiveness of the therapeutic interventions. (orig.)

  13. Antimicrobial resistance

    DEFF Research Database (Denmark)

    Llor, Carl; Bjerrum, Lars

    2014-01-01

    Antimicrobial resistance is a global public health challenge, which has accelerated by the overuse of antibiotics worldwide. Increased antimicrobial resistance is the cause of severe infections, complications, longer hospital stays and increased mortality. Overprescribing of antibiotics......-the-counter sale of antibiotics, the use of antimicrobial stewardship programmes, the active participation of clinicians in audits, the utilization of valid rapid point-of-care tests, the promotion of delayed antibiotic prescribing strategies, the enhancement of communication skills with patients with the aid...

  14. Trimaran Resistance Artificial Neural Network

    Science.gov (United States)

    2011-01-01

    11th International Conference on Fast Sea Transportation FAST 2011, Honolulu, Hawaii, USA, September 2011 Trimaran Resistance Artificial Neural Network Richard...Trimaran Resistance Artificial Neural Network 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e... Artificial Neural Network and is restricted to the center and side-hull configurations tested. The value in the parametric model is that it is able to

  15. Clinical epidemiology and resistance mechanisms of carbapenem-resistant Acinetobacter baumannii, French Guiana, 2008-2014.

    Science.gov (United States)

    Mahamat, Aba; Bertrand, Xavier; Moreau, Brigitte; Hommel, Didier; Couppie, Pierre; Simonnet, Christine; Kallel, Hatem; Demar, Magalie; Djossou, Felix; Nacher, Mathieu

    2016-07-01

    This study investigated the clinical epidemiology and resistance mechanisms of Acinetobacter baumannii and characterised the clonal diversity of carbapenem-resistant A. baumannii (CRAB) during an ICU-associated outbreak at Cayenne Hospital, French Guiana. All non-duplicate A. baumannii isolates from 2008 to 2014 were tested for antibiotic susceptibility by disk diffusion. Multilocus sequence typing, pulsed-field gel electrophoresis (PFGE) and characterisation of carbapenemase-encoding genes were performed on CRAB. Of the 441 A. baumannii isolates, most were from males (54.0%) and were detected mainly from the ICU (30.8%) and medicine wards (21.8%). In the ICU, strains were mainly isolated from the respiratory tract (44.1%) and bloodstream (14.0%), whereas in medicine wards they mainly were from wound/drainage (36.5%) and bloodstream (25.0%). A. baumannii showed the greatest susceptibility to piperacillin/tazobactam (92.7%), imipenem (92.5%), colistin (95.6%) and amikacin (97.2%), being lower in the ICU and medicine wards compared with other wards. An outbreak of OXA-23-producing CRAB occurred in the 13-bed ICU in 2010. CRAB strains were more co-resistant to other antimicrobials compared with non-CRAB. Molecular genetics analysis revealed five sequence types [ST78, ST107 and ST642 and two new STs (ST830 and ST831)]. Analysis of PFGE profiles indicated cross-transmissions of CRAB within the ICU, between the ICU and one medicine ward during transfer of patients, and within that medicine ward. This study provides the first clinical and molecular data of A. baumannii from French Guiana and the Amazon basin. The ICU was the highest risk unit of this nosocomial outbreak of OXA-23-producing CRAB, which could subsequently disseminate within the hospital. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  16. Turing instability in reaction-diffusion systems with nonlinear diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Zemskov, E. P., E-mail: zemskov@ccas.ru [Russian Academy of Sciences, Dorodnicyn Computing Center (Russian Federation)

    2013-10-15

    The Turing instability is studied in two-component reaction-diffusion systems with nonlinear diffusion terms, and the regions in parametric space where Turing patterns can form are determined. The boundaries between super- and subcritical bifurcations are found. Calculations are performed for one-dimensional brusselator and oregonator models.

  17. International Perspectives on the Profile of Highly Talented International Business Professionals

    Science.gov (United States)

    van Heugten, Petra; Heijne-Penninga, Marjolein; Robbe, Patricia; Jaarsma, Debbie; Wolfensberger, Marca

    2017-01-01

    There is a global demand for talented managers and leaders. To meet this demand, higher education institutions are developing talent programs. However, international perception of talent is diffuse. In this study, our profile of highly talented international business professionals was internationally validated by 172 participants, representing…

  18. Diffusion tensor imaging of the nigrostriatal fibers in Parkinson's disease.

    Science.gov (United States)

    Zhang, Yu; Wu, I-Wei; Buckley, Shannon; Coffey, Christopher S; Foster, Eric; Mendick, Susan; Seibyl, John; Schuff, Norbert

    2015-08-01

    Parkinson's disease (PD) is histopathologically characterized by the loss of dopamine neurons in the substantia nigra pars compacta. The depletion of these neurons is thought to reduce the dopaminergic function of the nigrostriatal pathway, as well as the neural fibers that link the substantia nigra to the striatum (putamen and caudate), causing a dysregulation in striatal activity that ultimately leads to lack of movement control. Based on diffusion tensor imaging, visualizing this pathway and measuring alterations of the fiber integrity remain challenging. The objectives were to 1) develop a diffusion tensor tractography protocol for reliably tracking the nigrostriatal fibers on multicenter data; 2) test whether the integrities measured by diffusion tensor imaging of the nigrostriatal fibers are abnormal in PD; and 3) test whether abnormal integrities of the nigrostriatal fibers in PD patients are associated with the severity of motor disability and putaminal dopamine binding ratios. Diffusion tensor tractography was performed on 50 drug-naïve PD patients and 27 healthy control subjects from the international multicenter Parkinson's Progression Marker Initiative. Tractography consistently detected the nigrostriatal fibers, yielding reliable diffusion measures. Fractional anisotropy, along with radial and axial diffusivity of the nigrostriatal tract, showed systematic abnormalities in patients. In addition, variations in fractional anisotropy and radial diffusivity of the nigrostriatal tract were associated with the degree of motor deficits in PD patients. Taken together, the findings imply that the diffusion tensor imaging characteristic of the nigrostriatal tract is potentially an index for detecting and staging of early PD. © 2015 International Parkinson and Movement Disorder Society.

  19. MR imaging of diffuse thyroid disorders

    International Nuclear Information System (INIS)

    Inoue, Masaaki; Fujii, Koichi; Ohnishi, Takuya; Higashikawa, Motoki; Araki, Yutaka; Hamada, Tatsumi; Ishida, Osamu

    1996-01-01

    Magnetic resonance imaging was performed in 38 diffuse goiters, including 30 chronic thyroiditis and 8 Basedow disease. MR findings were analyzed as to degree of swelling, margin, internal structures including homogeneity and low intensity bands. With regard to signal intensity, thyroid-muscle-signal intensity ratios on T1 and T2-weighted images were measured in 19 normal thyroid glands, 30 chronic thyroiditis and 8 Basedow disease. Additionally thyroid-muscle-signal intensity ratios were compared between 19 hypothyroid glands and 11 euthyroid glands in chronic thyroiditis. Chronic thyroiditis tended to show lobulated margins, inhomogeneous intensity, and low intensity bands connecting with vessels or not. Basedow disease tended to display smooth margins, inhomogeneous intensity and low intensity bands connecting with vessels. Thyroid-muscle-signal intensity ratios of Basedow disease and chronic thyroiditis were significantly higher than those of normal thyroid gland at all sequences. In chronic thyroiditis thyroid-muscle-signal intensity ratios of euthyroid glands were significantly higher than those of hypothyroid glands. MR imaging could reflect pathologic features of diffuse goiters. Moreover, MR imaging is potentially contributory to speculate about thyroid function and degree of serious condition in diffuse thyroid disorders. (author)

  20. Diffusion of titanium and nickel in B2 NiTi

    Czech Academy of Sciences Publication Activity Database

    Divinski, S.V.; Stloukal, Ivo; Král, Lubomír; Herzig, Ch.

    289-292, - (2009), s. 377-382 ISSN 1012-0386. [DIMAT 2008, International Conference on Diffusion in Materials /7./. Lanzarote, Canary Islands , 28.10.2008-31.10.2008] Institutional research plan: CEZ:AV0Z20410507 Keywords : intermetallic compound NiTi * nickel nad titanium diffusion * diffusion mechanism Subject RIV: BJ - Thermodynamics http://www.scientific.net/DDF.289-292.377/

  1. A mathematical and numerical analysis of the Maxwell-Stefan diffusion equations

    OpenAIRE

    Boudin , Laurent; Grec , Bérénice; Salvarani , Francesco

    2012-01-01

    International audience; We consider the Maxwell-Stefan model of diffusion in a multicomponent gaseous mixture. After focusing on the main differences with the Fickian diffusion model, we study the equations governing a three-component gas mixture. We provide a qualitative and quantitative mathematical analysis of the model. The main properties of the standard explicit numerical scheme are also analyzed. We eventually include some numerical simulations pointing out the uphill diffusion phenome...

  2. Methods of diffusion of innovation within small seafood enterprises ...

    African Journals Online (AJOL)

    In present essay, technology level enhancement of small seafood enterprises is studied based on technology diffusion. New technologies attraction in small enterprises causes competition especially in small sea food enterprises in internal markets (considering lack of water resources). Therefore, to accomplish such thing, ...

  3. Comparison Of Diffuse Solar Radiation Models Using Data For ...

    African Journals Online (AJOL)

    Measurements of global solar radiation and sunshine duration data during the period from 1984 to 1999 were supplied by IITA (International Institute of Tropical Agriculture) at Onne. The data were used to establish empirical relationships that would connect the daily monthly average diffuse irradiation with both relative ...

  4. Outwitting the series resistance in scanning spreading resistance microscopy

    International Nuclear Information System (INIS)

    Schulze, A.; Cao, R.; Eyben, P.; Hantschel, T.; Vandervorst, W.

    2016-01-01

    The performance of nanoelectronics devices critically depends on the distribution of active dopants inside these structures. For this reason, dopant profiling has been defined as one of the major metrology challenges by the international technology roadmap of semiconductors. Scanning spreading resistance microscopy (SSRM) has evolved as one of the most viable approaches over the last decade due to its excellent spatial resolution, sensitivity and quantification accuracy. However, in case of advanced device architectures like fins and nanowires a proper measurement of the spreading resistance is often hampered by the increasing impact of parasitic series resistances (e.g. bulk series resistance) arising from the confined nature of the aforementioned structures. In order to overcome this limitation we report in this paper the development and implementation of a novel SSRM mode (fast Fourier transform-SSRM: FFT-SSRM) which essentially decouples the spreading resistance from parasitic series resistance components. We show that this can be achieved by a force modulation (leading to a modulated spreading resistance signal) in combination with a lock-in deconvolution concept. In this paper we first introduce the principle of operation of the technique. We discuss in detail the underlying physical mechanisms as well as the technical implementation on a state-of-the-art atomic force microscope (AFM). We demonstrate the performance of FFT-SSRM and its ability to remove substantial series resistance components in practice. Eventually, the possibility of decoupling the spreading resistance from the intrinsic probe resistance will be demonstrated and discussed. - Highlights: • A novel electrical AFM mode for carrier profiling in confined volumes is presented. • Thereby the force and hence the contact area between AFM probe and sample is modulated. • Information on the spreading resistance is derived using a lock-in approach. • Bulk series resistance components are

  5. Study of the background of the neutrinoless double {beta} decay with the detector NEMO 2: contribution arising from the radon diffusion and internal pollution of the source {sup 214}Bi have been estimated; Etude du bruit de fond de la double-desintegration {beta} sans emission de neutrino dans le detecteur NEMO 2: contribution du radon ambiant et mesure de la pollution interne de la source en {sup 214}Bi

    Energy Technology Data Exchange (ETDEWEB)

    Mauger, F.

    1995-02-01

    The NEMO experiment is designed to understand the nature of the neutrino by studying the double beta decay of Mo-100 which is related to the Majorana neutrino effective mass. In this kind of experiment a good understanding of the different sources of background is crucial as only few events are expected per year at the required level of sensitivity. In this thesis we present the main theoretical and experimental aspects of the measurement of the neutrinoless double beta decay of Mo-100 with the prototype detector NEMO2. The goal of this study is to obtain a realistic interpretation of the few events detected at high energy in the two-electron channel as a background to neutrinoless double beta decay. In particular, the contribution arising from Bi-214 has been investigated. These events have been selected and analysed by means of the beta-alpha decays of Bi-214 into Pb-210. The events are characterized by a delayed track in the wire chamber and the corresponding signal is rather clean. The study has demonstrated the diffusion of Rn-222 into the detector and its contribution to Bi-214 pollution has been estimated. A measurement of the Bi-214 internal contamination of the source has been made as well as an estimation of the Bi-214 deposit due to Rn-222. As a result of this study it appears that, under the conditions of the NEMO2 experiment, the Bi and Rn contributions are of the same order of magnitude as the background induced at high energy by two-neutrino double beta decay. In conclusion, the backgrounds of the neutrinoless double beta decay of Mo-100 are well understood in the NEMO2 experiment leading to an extrapolation for the NEMO3 experiment. (authors).

  6. Models of diffuse solar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Boland, John; Ridley, Barbara [Centre for Industrial and Applied Mathematics, University of South Australia, Mawson Lakes Boulevard, Mawson Lakes, SA 5095 (Australia); Brown, Bruce [Department of Statistics and Applied Probability, National University of Singapore, Singapore 117546 (Singapore)

    2008-04-15

    For some locations both global and diffuse solar radiation are measured. However, for many locations, only global is measured, or inferred from satellite data. For modelling solar energy applications, the amount of radiation on a tilted surface is needed. Since only the direct component on a tilted surface can be calculated from trigonometry, we need to have diffuse on the horizontal available. There are regression relationships for estimating the diffuse on a tilted surface from diffuse on the horizontal. Models for estimating the diffuse radiation on the horizontal from horizontal global that have been developed in Europe or North America have proved to be inadequate for Australia [Spencer JW. A comparison of methods for estimating hourly diffuse solar radiation from global solar radiation. Sol Energy 1982; 29(1): 19-32]. Boland et al. [Modelling the diffuse fraction of global solar radiation on a horizontal surface. Environmetrics 2001; 12: 103-16] developed a validated model for Australian conditions. We detail our recent advances in developing the theoretical framework for the approach reported therein, particularly the use of the logistic function instead of piecewise linear or simple nonlinear functions. Additionally, we have also constructed a method, using quadratic programming, for identifying values that are likely to be erroneous. This allows us to eliminate outliers in diffuse radiation values, the data most prone to errors in measurement. (author)

  7. Osmosis and Diffusion Conceptual Assessment

    Science.gov (United States)

    Fisher, Kathleen M.; Williams, Kathy S.; Lineback, Jennifer Evarts

    2011-01-01

    Biology student mastery regarding the mechanisms of diffusion and osmosis is difficult to achieve. To monitor comprehension of these processes among students at a large public university, we developed and validated an 18-item Osmosis and Diffusion Conceptual Assessment (ODCA). This assessment includes two-tiered items, some adopted or modified…

  8. The diffusion of constitutional rights

    NARCIS (Netherlands)

    Goderis, B.V.G.; Versteeg, M.

    Constitutions are commonly regarded as uniquely national products, shaped by domestic ideals and politics. This paper develops and empirically investigates a novel hypothesis, which is that constitutions are also shaped by transnational influence, or “diffusion.” Constitutional rights can diffuse

  9. Diffusion measurements by Raman spectroscopy

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Shapiro, Alexander; Berg, Rolf W.

    Poster "Diffusion measurements by Raman spectroscopy", See poster at http://www.kemi.dtu.dk/~ajo/rolf/petroday2004.ppt......Poster "Diffusion measurements by Raman spectroscopy", See poster at http://www.kemi.dtu.dk/~ajo/rolf/petroday2004.ppt...

  10. Consequences of Diffusion of Innovations.

    Science.gov (United States)

    Goss, Kevin F.

    1979-01-01

    The article traces evolution of diffusion theory; illustrates undesirable consequences in a cross-cultural setting, reviews criticisms of several scholars; considers distributional effects and unanticipated consequences for potential ameliorative impact on diffusion theory; and codifies these factors into a framework for research into consequences…

  11. Enhancement of diffusers BRDF accuracy

    Science.gov (United States)

    Otter, Gerard; Bazalgette Courrèges-Lacoste, Gregory; van Brug, Hedser; Schaarsberg, Jos Groote; Delwart, Steven; del Bello, Umberto

    2017-11-01

    This paper reports the result of an ESA study conducted at TNO to investigate properties of various diffusers. Diffusers are widely used in space instruments as part of the on-board absolute calibration. Knowledge of the behaviour of the diffuser is therefore most important. From measurements of launched instruments in-orbit it has been discovered that when a diffuser is used in the vacuum of space the BRDF can change with respect to the one in ambient conditions. This is called the air/vacuum effect and has been simulated in this study by measuring the BRDF in a laboratory in ambient as well as vacuum conditions. Another studied effect is related to the design parameters of the optical system and the scattering properties of the diffuser. The effect is called Spectral Features and is a noise like structure superimposed on the diffuser BRDF. Modern space spectrometers, which have high spectral resolution and/or a small field of view (high spatial resolution) are suffering from this effect. The choice of diffuser can be very critical with respect to the required absolute radiometric calibration of an instrument. Even if the Spectral Features are small it can influence the error budget of the retrieval algorithms for the level 2 products. in this presentation diffuser trade-off results are presented and the Spectral Features model applied to the optical configuration of the MERIS instrument is compared to in-flight measurements of MERIS.

  12. Resistance patterns of Staphylococcus aureus and Pseudomonas ...

    African Journals Online (AJOL)

    Two hundred (200) strains of S. aureus and P. aeruginosa were isolated from clinical samples collected from patients in Murtala Muhammad Specialist Hospital and Infectious Diseases Hospital, Kano. The confirmed isolates were tested for resistance to quinolones by the agar disk diffusion susceptibility test and the agar ...

  13. Addimer diffusions on Si(100)

    International Nuclear Information System (INIS)

    Lee, Gun Do; Wang, C. Z.; Lu, Z. Y.; Ho, K. M.

    1999-01-01

    The diffusion pathways along the trough and between the trough and the dimer row on the Si(100) surface are investigated by tight-binding molecular dynamics calculations using the environment dependent tight-binding silicon potential and by ab initio calculations using the Car-Parrinello method. The studies discover new diffusion pathways consisting of rotation of addimer. The calculated energy barrier are in excellent agreement with experiment. The rotational diffusion pathway between the trough and the dimer row is much more energetically favorable than other diffusion pathways by parallel and perpendicular addimer. The new pathway along the trough is nearly same as the energy barrier of the diffusion pathway by dissociation of the addimer

  14. Application of polycrystalline diffusion barriers

    International Nuclear Information System (INIS)

    Tsymbal, V.A.; Kolupaev, I.N.

    2010-01-01

    Degradation of contacts of the electronic equipment at the raised temperatures is connected with active diffusion redistribution of components contact - metalized systems (CMS) and phase production on interphase borders. One of systems diffusion barriers (DB) are polycrystalline silicide a film, in particular silicides of the titan. Reception disilicide the titan (TiSi 2 ) which on the parameters is demanded for conditions of microelectronics from known silicides of system Ti-Si, is possible as a result of direct reaction of a film of the titan and a substrate of silicon, and at sedimentation of layer Ti-Si demanded stoichiometric structure. Simultaneously there is specific problem polycrystalline diffusion a barrier (PDB): the polycrystalline provides structural balance and metastability film disilicide, but leaves in it borders of grains - easy local ways of diffusion. In clause the analysis diffusion permeability polycrystalline and polyphase DB is made and recommendations for practical methods of increase of blocking properties PDB are made.

  15. Resistant hypertension.

    Science.gov (United States)

    Wei, Fang-Fei; Zhang, Zhen-Yu; Huang, Qi-Fang; Yang, Wen-Yi; Staessen, Jan A

    2018-06-15

    The publication of the first non-randomised proof-of-concept trial of renal denervation as a treatment modality in treatment-resistant hypertension set the stage for a search for novel devices with the expectation that technology would reduce the burden of hypertension by reducing or eliminating the costly and lifelong use of blood pressure lowering medications. As we demonstrate in this review, this idea so attractive to manufacturers and invasive cardiologists and radiologists overlooked decades of careful pathophysiological research in a disease, which still remains enigmatic but remains the major cause of cardiovascular mortality worldwide. To make our point, we first reviewed the prevalence and risks associated with treatment-resistant hypertension. Next, we highlighted the key points required for the diagnosis of treatment-resistant hypertension, including the recording of the ambulatory blood pressure and the assessment of adherence to medication. Finally, we summarised new insights in the management of treatment-resistant hypertension by medication and devices and in the future research. Throughout our review, we focused on new evidence became available since 2013. Our conclusion is that optimising medical treatment based on simple algorithms remains the state of the art in treatment-resistant hypertension.

  16. Diffusion in membranes: Toward a two-dimensional diffusion map

    Directory of Open Access Journals (Sweden)

    Toppozini Laura

    2015-01-01

    Full Text Available For decades, quasi-elastic neutron scattering has been the prime tool for studying molecular diffusion in membranes over relevant nanometer distances. These experiments are essential to our current understanding of molecular dynamics of lipids, proteins and membrane-active molecules. Recently, we presented experimental evidence from X-ray diffraction and quasi-elastic neutron scattering demonstrating that ethanol enhances the permeability of membranes. At the QENS 2014/WINS 2014 conference we presented a novel technique to measure diffusion across membranes employing 2-dimensional quasi-elastic neutron scattering. We present results from our preliminary analysis of an experiment on the cold neutron multi-chopper spectrometer LET at ISIS, where we studied the self-diffusion of water molecules along lipid membranes and have the possibility of studying the diffusion in membranes. By preparing highly oriented membrane stacks and aligning them horizontally in the spectrometer, our aim is to distinguish between lateral and transmembrane diffusion. Diffusion may also be measured at different locations in the membranes, such as the water layer and the hydrocarbon membrane core. With a complete analysis of the data, 2-dimensional mapping will enable us to determine diffusion channels of water and ethanol molecules to quantitatively determine nanoscale membrane permeability.

  17. The magnetic diffusion of neutrons; La diffusion magnetique des neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, W C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    The purpose of this report is to examine briefly the diffusion of neutrons by substances, particularly by crystals containing permanent atomic or ionic magnetic moments. In other words we shall deal with ferromagnetic, antiferromagnetic, ferrimagnetic or paramagnetic crystals, but first it is necessary to touch on nuclear diffusion of neutrons. We shall start with the interaction of the neutron with a single diffusion centre; the results will then be applied to the magnetic interactions of the neutron with the satellite electrons of the atom; finally we shall discuss the diffusion of neutrons by crystals. (author) [French] Le but de ce rapport est d'examiner, brievement, la diffusion des neutrons par les substances, et surtout, par des cristaux qui contiennent des moments magnetiques atomiques ou ioniques permanents. C'est-a-dire que nous nous interesserons aux cristaux ferromagnetiques, antiferromagnetiques, ferrimagnetiques ou paramagnetiques; il nous faut cependant rappeler d'abord la diffusion nucleaire des neutrons. Nous commencerons par l'interaction du neutron avec un seul centre diffuseur; puis les resultats seront appliques aux interactions magnetiques du neutron avec les electrons satellites de l'atome; enfin nous discuterons la diffusion des neutrons par les cristaux. (auteur)

  18. Multidimensional diffusion processes

    CERN Document Server

    Stroock, Daniel W

    1997-01-01

    From the reviews: "… Both the Markov-process approach and the Itô approach … have been immensely successful in diffusion theory. The Stroock-Varadhan book, developed from the historic 1969 papers by its authors, presents the martingale-problem approach as a more powerful - and, in certain regards, more intrinsic-means of studying the foundations of the subject. […] … the authors make the uncompromising decision not "to proselytise by intimidating the reader with myriad examples demonstrating the full scope of the techniques", but rather to persuade the reader "with a careful treatment of just one problem to which they apply". […] Most of the main tools of stochastic-processes theory are used, ..but it is the formidable combination of probability theory with analysis … which is the core of the work. […] I have emphasized the great importance of the Stroock-Varadhan book. It contains a lot more than I have indicated; in particular, its many exercises conain much interesting material. For immediat...

  19. Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    Alkaline electrolysis cells operated at 250 °C and 40 bar have shown to be able to convert electrical energy into chemical energy in the form of hydrogen at very high efficiencies and power densities. Foam based gas diffusion electrodes and a liquid immobilized electrolyte allow the operation...... of the newly designed electrolysis cell as a fuel cell, but condensation of steam may lead to blocked pores, thereby inhibiting gas diffusion and decreasing the performance of the cell. In the here presented work we present the application of a hydrophobic, porous, and electro-catalytically active layer...... the electrochemical characteristics of the cell. The thickness of the electrolyte matrix was reduced to 200 µm, thereby achieving a serial resistance and area specific resistance as low as 60 mΩ cm2 and 150 mΩ cm2, respectively, at a temperature of 200 °C and 20 bar pressure. A new production method was developed...

  20. Plasmid Conjugation in E. coli and Drug Resistance | Igwe ...

    African Journals Online (AJOL)

    This study aimed at determining the antibiotics susceptibility pattern of E. coli isolates claimed to be multidrug resistance using disc diffusion method. It also determined the presence of transferable resistance plasmids through conjugation and evaluated the medical significance of plasmid encoding E. coli and drug ...

  1. International Technology Diffusion of Joint and Cross-border Patents

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); M.J. McAleer (Michael); J-T. Tang (Ju-Ting)

    2013-01-01

    textabstractWith the advent of globalization, economic and financial interactions among countries have become widespread. Given technological advancements, the factors of production can no longer be considered to be just labor and capital. In the pursuit of economic growth, every country has

  2. International Technology Diffusion of Joint and Cross-border Patents

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); M.J. McAleer (Michael); J-T. Tang (Ju-Ting)

    2015-01-01

    markdownabstract__Abstract__ With the advent of globalization, economic and financial interactions among countries have become widespread. Given technological advancements, the factors of production can no longer be considered to be just labor and capital. In the pursuit of economic growth, every

  3. International Technology Diffusion of Joint and Cross-border Patents

    NARCIS (Netherlands)

    C-L. Chang (Chia-Lin); M.J. McAleer (Michael); J-T. Tang (Ju-Ting)

    2015-01-01

    markdownabstract__Abstract__ With the advent of globalization, economic and financial interactions among countries have become widespread. Given technological advancements, the factors of production can no longer be considered to be just labor and capital. In the pursuit of economic growth,

  4. Anticoagulant Resistance

    DEFF Research Database (Denmark)

    Heiberg, Ann-Charlotte

    Although sewer rat control is carried out in more than 80 % of all Danish municipalities, with usage of large amounts of anticoagulant rodenticides, knowledge on anticoagulant resistance among rats living in the sewers is limited. As rat problems in urban areas are believed to be related to sewer...... problems (70-90 % in UK and DK) unawareness of resistance amongst these populations of Brown rats may constitute a future control problem and knowledge on this issue has become crucial. Rats were captured in sewers from seven different locations in the suburban area of Copenhagen. Locations was chosen...... to represent different sewer rat management strategies i) no anticoagulants for approx. 20 years ii) no anticoagulants for the last 5 years and iii) continuous control for many years. Animals were tested for resistance to bromadiolone by Blood-Clotting Response test, as bromadiolone is the most frequently used...

  5. Trade, Technology Diffusion and Misallocation : Trade Partner Matters (Replaces CentER DP 2011-125)

    NARCIS (Netherlands)

    Curuk, M.

    2012-01-01

    Abstract: This paper suggests that contingent on the productivity level of the trade partner; international trade may create resource misallocation in less productive countries. It theoretically shows how the interaction between technology diffusion induced by trade and cross sectoral heterogeneity

  6. Diffusion libre du droit est-elle acquise... pour de bon? | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Depuis, un mouvement de la diffusion libre du droit, soutenu par les instituts ... des documents juridiques des documents du domaine public, consultables en ligne ... International Water Resources Association, in close collaboration with IDRC, ...

  7. Diffusive instabilities in hyperbolic reaction-diffusion equations

    Science.gov (United States)

    Zemskov, Evgeny P.; Horsthemke, Werner

    2016-03-01

    We investigate two-variable reaction-diffusion systems of the hyperbolic type. A linear stability analysis is performed, and the conditions for diffusion-driven instabilities are derived. Two basic types of eigenvalues, real and complex, are described. Dispersion curves for both types of eigenvalues are plotted and their behavior is analyzed. The real case is related to the Turing instability, and the complex one corresponds to the wave instability. We emphasize the interesting feature that the wave instability in the hyperbolic equations occurs in two-variable systems, whereas in the parabolic case one needs three reaction-diffusion equations.

  8. Antibiotic Resistance and Antibiotic Resistance Genes in Escherichia coli Isolates from Hospital Wastewater in Vietnam.

    Science.gov (United States)

    Lien, La Thi Quynh; Lan, Pham Thi; Chuc, Nguyen Thi Kim; Hoa, Nguyen Quynh; Nhung, Pham Hong; Thoa, Nguyen Thi Minh; Diwan, Vishal; Tamhankar, Ashok J; Stålsby Lundborg, Cecilia

    2017-06-29

    The environmental spread of antibiotic-resistant bacteria has been recognised as a growing public health threat for which hospitals play a significant role. The aims of this study were to investigate the prevalence of antibiotic resistance and antibiotic resistance genes (ARGs) in Escherichia coli isolates from hospital wastewater in Vietnam. Wastewater samples before and after treatment were collected using continuous sampling every month over a year. Standard disk diffusion and E-test were used for antibiotic susceptibility testing. Extended-spectrum beta-lactamase (ESBL) production was tested using combined disk diffusion. ARGs were detected by polymerase chain reactions. Resistance to at least one antibiotic was detected in 83% of isolates; multidrug resistance was found in 32%. The highest resistance prevalence was found for co-trimoxazole (70%) and the lowest for imipenem (1%). Forty-three percent of isolates were ESBL-producing, with the bla TEM gene being more common than bla CTX-M . Co-harbouring of the bla CTX-M , bla TEM and qepA genes was found in 46% of isolates resistant to ciprofloxacin. The large presence of antibiotic-resistant E. coli isolates combined with ARGs in hospital wastewater, even post-treatment, poses a threat to public health. It highlights the need to develop effective processes for hospital wastewater treatment plants to eliminate antibiotic resistant bacteria and ARGs.

  9. Surface electrical resistivity of insulators

    International Nuclear Information System (INIS)

    Senn, B. C.; Liesegang, J.

    1996-01-01

    A method is presented here for measuring surface charge decay, and theory has been developed so as to produce determinations of resistivity in the surface region of insulator films or wafers. This method incorporates the use of a coaxial cylindrical capacitor arrangement and an electrometer interfaced to a PC. The charge transport theory given here is based on Mott-Gurney diffusion, and allows easy interpretation of the experimental data, especially for the initial phase of surface charge decay. Resistivity measurements are presented for glass, mica, perspex and polyethylene, covering a range of 10 9 to 10 18 Ωm, as an illustration of the useful range of the instrument for static and antistatic materials, particularly in film or sheet form. Values for the surface charge diffusion constants of the materials are also presented. The charge transport theory has also been extended to allow the experimental and computational theoretical comparison of surface charge decay not only over the initial phase of charge decay, but also over longer times. The theoretical predictions show excellent agreement with experiment using the values for the diffusion constants referred to above

  10. Diffused zircaloy 2/stainless steel junctions; Jonctions diffusees zircaloy 2 - acier inoxydable

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-07-01

    The diffusion permits to realize joints between two different materials, in fact of the formation of a liquid phase at the contact face. The study of the tensile properties allowed the determination of the ideal conditions for the diffusion treatment which are, within 2 and 3 minutes for a temperature within 1020 C and 1030 C. The characteristics of the so obtained joints were, studied: mechanical properties, tightness, resistance to thermal cycling. Analysis of the thermal stress, owing to the differential dilatation of the two materials mode the object of a particular study. The investigation on the diffusion zone, includes specially, an analysis of the constituents distribution formed during the diffusion treatment. (author) [French] La diffusion permet de realiser des joints entre deux materiaux differents, du fait de la formation d'une phase liquide a l'interface de contact. L'etude de la resistance a la traction a permis de determiner les conditions optimum du traitement de diffusion: une duree de 2 a 3 minutes pour une temperature comprise entre 1020 C et 1030 C. Les caracteristiques des jonctions ainsi obtenues ont ete etudiees: proprietes mecaniques, etancheite, resistance au cyclage thermique. L'analyse des contraintes thermiques dues a la difference de dilatation des deux materiaux, a fait l'objet d'une etude particuliere. L'etude metallurgique de la zone diffusee comporte en particulier une analyse de la repartition des constituants formes lors du traitement de diffusion. (auteur)

  11. Is there ballistic transport in metallic nano-objects? Ballistic versus diffusive contributions

    International Nuclear Information System (INIS)

    Garcia, N; Bai Ming; Lu Yonghua; Munoz, M; Cheng Hao; Levanyuk, A P

    2007-01-01

    When discussing the resistance of an atomic-or nanometre-size contact we should consider both its ballistic and its diffusive contributions. But there is a contribution of the leads to the resistance of the contact as well. In this context, the geometry and the roughness of the surfaces limiting the system will contribute to the resistance, and these contributions should be added to the ideal ballistic resistance of the nanocontact. We have calculated, for metallic materials, the serial resistance of the leads arising from the roughness, and our calculations show that the ohmic resistance is as important as the ballistic resistance of the constriction. The classical resistance is a lower limit to the quantum resistance of the leads. Many examples of earlier experiments show that the mean free path of the transport electrons is of the order of the size of the contacts or the leads. This is not compatible with the idea of ballistic transport. This result may put in serious difficulties the current, existing interpretation of experimental data in metals where only small serial resistances compared with the ballistic component of the total resistance have been taken into account. The two-dimensional electron gas (2DEG) is also discussed and the serial corrections appear to be smaller than for metals. Experiments with these last systems are proposed that may reveal new interesting aspects in the physics of ballistic and diffusive transport

  12. Diffusion tensor optical coherence tomography

    Science.gov (United States)

    Marks, Daniel L.; Blackmon, Richard L.; Oldenburg, Amy L.

    2018-01-01

    In situ measurements of diffusive particle transport provide insight into tissue architecture, drug delivery, and cellular function. Analogous to diffusion-tensor magnetic resonance imaging (DT-MRI), where the anisotropic diffusion of water molecules is mapped on the millimeter scale to elucidate the fibrous structure of tissue, here we propose diffusion-tensor optical coherence tomography (DT-OCT) for measuring directional diffusivity and flow of optically scattering particles within tissue. Because DT-OCT is sensitive to the sub-resolution motion of Brownian particles as they are constrained by tissue macromolecules, it has the potential to quantify nanoporous anisotropic tissue structure at micrometer resolution as relevant to extracellular matrices, neurons, and capillaries. Here we derive the principles of DT-OCT, relating the detected optical signal from a minimum of six probe beams with the six unique diffusion tensor and three flow vector components. The optimal geometry of the probe beams is determined given a finite numerical aperture, and a high-speed hardware implementation is proposed. Finally, Monte Carlo simulations are employed to assess the ability of the proposed DT-OCT system to quantify anisotropic diffusion of nanoparticles in a collagen matrix, an extracellular constituent that is known to become highly aligned during tumor development.

  13. In Vitro Activity of the New Fluoroketolide Solithromycin (CEM-101) against a Large Collection of Clinical Neisseria gonorrhoeae Isolates and International Reference Strains, Including Those with High-Level Antimicrobial Resistance: Potential Treatment Option for Gonorrhea?

    Science.gov (United States)

    Golparian, Daniel; Fernandes, Prabhavathi; Ohnishi, Makoto; Jensen, Jörgen S.

    2012-01-01

    Gonorrhea may become untreatable, and new treatment options are essential. We investigated the in vitro activity of the first fluoroketolide, solithromycin. Clinical Neisseria gonorrhoeae isolates and reference strains (n = 246), including the two extensively drug-resistant strains H041 and F89 and additional isolates with clinical cephalosporin resistance and multidrug resistance, were examined. The activity of solithromycin was mainly superior to that of other antimicrobials (n = 10) currently or previously recommended for gonorrhea treatment. Solithromycin might be an effective treatment option for gonorrhea. PMID:22354296

  14. Macrolides for diffuse panbronchiolitis.

    Science.gov (United States)

    Lin, Xiufang; Lu, Jing; Yang, Ming; Dong, Bi Rong; Wu, Hong Mei

    2015-01-25

    Diffuse panbronchiolitis (DPB) is a chronic airways disease predominantly affecting East Asians. Macrolides, a class of antibiotics, have been used as the main treatment for DPB, based on evidence from retrospective and non-randomised studies. To assess the efficacy and safety of macrolides for DPB. We searched CENTRAL (2014, Issue 6), MEDLINE (1966 to July week 1, 2014), EMBASE (1974 to July 2014), Chinese Biomedical Literature Database (CBM) (1978 to July 2014), China National Knowledge Infrastructure (CNKI) (1974 to July 2014), KoreaMed (1997 to July 2014) and Database of Japana Centra Revuo Medicina (1983 to July 2014). Randomised controlled trials (RCTs) or quasi-RCTs assessing the effect of macrolides for DPB. Two review authors independently assessed study quality and subsequent risk of bias according to The Cochrane Collaboration's tool for assessing risk of bias. The primary outcomes were five-year survival rate, lung function and clinical response. We used risk ratios (RR) for individual trial results in the data analysis and measured all outcomes with 95% confidence intervals (CI). Only one RCT (19 participants) with significant methodological limitations was included in this review. It found that the computerised tomography images of all participants treated with a long-term, low-dose macrolide (erythromycin) improved from baseline, while the images of 71.4% of participants in the control group (with no treatment) worsened and 28.6% remained unchanged. Adverse effects were not reported. This review was previously published in 2010 and 2013. For this 2014 update, we identified no new trials for inclusion or exclusion. There is little evidence for macrolides in the treatment of DPB. We are therefore unable to make any new recommendations. It may be reasonable to use low-dose macrolides soon after diagnosis is made and to continue this treatment for at least six months, according to current guidelines.

  15. Study of the factors affecting radon diffusion through building materials

    International Nuclear Information System (INIS)

    Chauhan, R.P.

    2011-01-01

    Radon appears mainly by diffusion processes from the point of origin following - decay of 226 Ra in underground soil and building materials used, in the construction of floors, walls, and ceilings. The diffusion of radon in dwellings is a process determined by the radon concentration gradient across the building material structure and can be a significant contributor to indoor radon inflow. Radon can originate from the deeply buried deposit beneath homes and can migrate to the surface of earth. Radon diffusion and transport through different media is a complex process and is affected by several factors. It is well known that for building construction materials the porosity, permeability and the diffusion coefficient are the parameters, which can quantify the materials capability to hinder the flow of radon soil gas. An increase in porosity will provide more air space within the material for radon to travel, thus reducing its resistance to radon transport. The permeability of material describes its ability to act as a barrier to gas movement when a pressure gradient exists across it and is closely related to the porosity of material. The radon diffusion coefficient of a material quantifies the ability of radon gas to move through it when a concentration gradient is the driving force. This parameter depends upon the porosity and permeability of the medium. As diffusion process is the major contributor to indoor levels, therefore, the factors affecting the diffusion process need to be kept in consideration. Keeping this in mind the experimental arrangements have been made for control study of radon diffusion through some building materials to observe the effects of different factors viz.; compaction, grain size, temperature, humidity and the mixing of these materials etc. For the present study alpha sensitive LR-115 type II solid-state nuclear track detectors (SSNTDs) have been used for the recording of alpha tracks caused by radon gas after its diffusion through the

  16. Antifungal resistance in mucorales.

    Science.gov (United States)

    Dannaoui, E

    2017-11-01

    The order Mucorales, which includes the agents of mucormycosis, comprises a large number of species. These fungi are characterised by high-level resistance to most currently available antifungal drugs. Standardised antifungal susceptibility testing methods are now available, allowing a better understanding of the in vitro activity of antifungal drugs against members of Mucorales. Such tests have made apparent that antifungal susceptibility within this group may be species-specific. Experimental animal models of mucormycosis have also been developed and are of great importance in bridging the gap between in vitro results and clinical trials. Amphotericin B, posaconazole and isavuconazole are currently the most active agents against Mucorales; however, their activity remains suboptimal and new therapeutic strategies are needed. Combination therapy could be a promising approach to overcome resistance, but further studies are required to confirm its benefits and safety for patients. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  17. Laser enhanced attachment in diffuse discharges

    International Nuclear Information System (INIS)

    Giesselmann, M.; Pashaie, B.; Kristiansen, M.; Schaefer, G.

    1987-01-01

    Measurements of the effect of laser enhanced attachment on externally sustained diffuse discharges are reported. Optical control of diffuse discharges is a promising way of upgrading the performance of e-beam controlled opening switches for repetitive operation. Ideal gases should exhibit a negligible attachment cross section for low E/N values (switch closed) in the ground state and strong attaching properties upon optical excitation in an E/N range between the conducting state and self breakdown of the switch. The ratio of resistivity change in these experiments is much higher than in previous investigations. In this investigation the attachment rate of an electronegative gas component, representing approximately 1% of the gas in the discharge volume, was increased by means of vibrational excitation with a pulsed IR-laser beam. Molecules exhibiting a strongly increased attachment rate upon IR-excitation are vinyl-chloride, vinyl flouride and trifluoroethylene, which has been verified in preliminary experiments. All experiments reported were performed with vinyl chloride and trifluoroethylene

  18. A pile-up phenomenon during arsenic diffusion in silicon-on-insulator structures formed by oxygen implantation

    Science.gov (United States)

    Normand, P.; Tsoukalas, D.; Guillemot, N.; Chenevier, P.

    1989-10-01

    Arsenic diffusion in silicon-on-insulator formed by deep oxygen implantation is studied by secondary ion mass spectroscopy and speading resistance measurements. An enhanced diffusivity as well as a pile-up phenomenon are observed in the thin silicon layer. The McNabb and Foster equations [Trans. TMS-AIME 22, 618 (1963)] for diffusion with trapping are solved in order to simulate this last effect.

  19. The effect of diffusion induced lattice stress on the open-circuit voltage in silicon solar cells

    Science.gov (United States)

    Weizer, V. G.; Godlewski, M. P.

    1984-01-01

    It is demonstrated that diffusion induced stresses in low resistivity silicon solar cells can significantly reduce both the open-circuit voltage and collection efficiency. The degradation mechanism involves stress induced changes in both the minority carrier mobility and the diffusion length. Thermal recovery characteristics indicate that the stresses are relieved at higher temperatures by divacancy flow (silicon self diffusion). The level of residual stress in as-fabricated cells was found to be negligible in the cells tested.

  20. Drug resistance

    NARCIS (Netherlands)

    Gorter, J.A.; Potschka, H.; Noebels, J.L.; Avoli, M.; Rogawski, M.A.; Olsen, R.W.; Delgado-Escueta, A.V.

    2012-01-01

    Drug resistance remains to be one of the major challenges in epilepsy therapy. Identification of factors that contribute to therapeutic failure is crucial for future development of novel therapeutic strategies for difficult-to-treat epilepsies. Several clinical studies have shown that high seizure

  1. Moessbauer effect and vacancy diffusion

    International Nuclear Information System (INIS)

    Gunther, L.

    1976-01-01

    A dynamical theory of vacancy diffusion which was motivated by the need to explain recent experimental results for the Moessbauer spectra of Fe in Cu, Fe in Au and Fe in Al is presented. Diffusion in these systems is dominated by the vacancy mechanism, which involves strong correlations between successive jumps. The theory developed by Singwi and Sjoelander for the Moessbauer spectrum of a diffusing nucleus is therefore not applicable. The inverse of the normalized Moessbauer spectrum evaluated at zero frequency is introduced as a useful means of comparing experimental with theoretical spectral widths

  2. Simulation of multivariate diffusion bridges

    DEFF Research Database (Denmark)

    Bladt, Mogens; Finch, Samuel; Sørensen, Michael

    We propose simple methods for multivariate diffusion bridge simulation, which plays a fundamental role in simulation-based likelihood and Bayesian inference for stochastic differential equations. By a novel application of classical coupling methods, the new approach generalizes a previously...... proposed simulation method for one-dimensional bridges to the mulit-variate setting. First a method of simulating approzimate, but often very accurate, diffusion bridges is proposed. These approximate bridges are used as proposal for easily implementable MCMC algorithms that produce exact diffusion bridges...

  3. Self diffusion in isotopic fluid

    International Nuclear Information System (INIS)

    Tankeshwar, K.

    1991-01-01

    Expressions for the second and fourth frequency sum rules of the velocity auto-correlation function have been obtained for an isotopic fluid. These expressions and Mori memory function formalism have been used to study the influence of the particle mass and mole fraction on the self diffusion coefficient. Our results confirm the weak mass dependence of the self diffusion. The influence of the mole fraction of the light particles on the self diffusion constant has been found to increase for the larger particle mass. (author). 17 refs, 1 fig., 2 tabs

  4. Muon diffusion in noble metals

    International Nuclear Information System (INIS)

    Schillaci, M.E.; Bokema, C.; Heffner, R.H.; Hutson, R.L.; Leon, M.; Olsen, C.E.; Dodds, S.A.; MacLaughlin, D.E.; Richards, P.M.

    1983-01-01

    Diffusion-induced muon depolarization in dilute AgGd and AgEr were measured in the temperature range 200-700 K and have thereby determined the muon diffusion parameters in Ag. The diffusion parameters for μ + in Cu, Ag, and Au are compared with those of hydrogen. For Ag and Au, the μ + parameters are similar to those of hydrogen, whereas for Cu, the μ + parameters are much smaller. Lattice-activated tunneling and over-barrier hopping are investigated with computational models. 15 references, 1 figure, 2 tables

  5. Muon diffusion in noble metals

    International Nuclear Information System (INIS)

    Schillaci, M.E.; Boekema, C.; Heffner, R.H.; Hutson, R.L.; Leon, M.; Olsen, C.E.; Dodds, S.A.; MacLaughlin, D.E.; Richards, P.M.

    1982-01-01

    Diffusion-induced muon depolarization was measured in dilute AgGd and AgEr in the temperature range 200 to 700 0 K and have thereby determined the muon diffusion parameters in Ag. The diffusion parameters for μ + in Cu, Ag, and Au are compared with those of hydrogen. For Ag and Au, the μ + parameters are similar to those of hydrogen, whereas for Cu, the μ + parameters are much smaller. Lattice-activated tunneling and over-barrier hopping are investigated with computational models

  6. SR-Can. Data and uncertainty assessment. Matrix diffusivity and porosity in situ

    Energy Technology Data Exchange (ETDEWEB)

    Jinsong Liu; Loefgren, Martin; Neretnieks, Ivars [Dept. of Chemical Engineering and Technology, Royal Inst. of Technology, Stockholm (Sweden)

    2006-12-15

    The molecular diffusion in microscopically small pores of crystalline rock matrices allows radionuclides to enter the stagnant matrix water. The water volume in the matrix is orders of magnitude larger than the mobile water in the flowing fractures. This effect will retard the nuclide migration. A further retardation effect is due to the sorption of the sorbing nuclides on the interior surfaces of the matrix. The internal surfaces are on the order of 100,000 times larger than the surfaces of the flowing fractures. It is therefore important to ensure that matrix diffusion will take place in intact rock under the stresses which prevail at repository depths. Laboratory experiments on drill cores have shown that the matrix porosity is connected over distances of at least several tens of centimetres for un-stressed samples. Samples that have been re-stressed to repository depth stresses have also been found to have connected porosity. Diffusivities in re-stressed samples were found to be up to three times lower than in un-stressed samples. This was found both using actual through-diffusion experiments as well as electrical conductivity measurements. Diffusion experiments are very time consuming, costly and difficult to make in deeply lying rock under undisturbed conditions. An alternative way of measuring the mobility of charged species in porous rock is by using electric current to carry the ions. For bulk water this has a long-standing theoretical basis and is used to determine ion diffusivities. The method has also long been used in laboratory investigation to measure diffusivities in porous rocks. It has been shown to give electrical conductivities that agree well with that expected from diffusivity measurements. A number of tests have been made with AC (alternating current) and DC (direct current) to measure resistivities as well as using DC current to conduct ions through rock samples. These tests clearly confirm that the different methods give comparable results

  7. SR-Can. Data and uncertainty assessment. Matrix diffusivity and porosity in situ

    International Nuclear Information System (INIS)

    Jinsong Liu; Loefgren, Martin; Neretnieks, Ivars

    2006-12-01

    The molecular diffusion in microscopically small pores of crystalline rock matrices allows radionuclides to enter the stagnant matrix water. The water volume in the matrix is orders of magnitude larger than the mobile water in the flowing fractures. This effect will retard the nuclide migration. A further retardation effect is due to the sorption of the sorbing nuclides on the interior surfaces of the matrix. The internal surfaces are on the order of 100,000 times larger than the surfaces of the flowing fractures. It is therefore important to ensure that matrix diffusion will take place in intact rock under the stresses which prevail at repository depths. Laboratory experiments on drill cores have shown that the matrix porosity is connected over distances of at least several tens of centimetres for un-stressed samples. Samples that have been re-stressed to repository depth stresses have also been found to have connected porosity. Diffusivities in re-stressed samples were found to be up to three times lower than in un-stressed samples. This was found both using actual through-diffusion experiments as well as electrical conductivity measurements. Diffusion experiments are very time consuming, costly and difficult to make in deeply lying rock under undisturbed conditions. An alternative way of measuring the mobility of charged species in porous rock is by using electric current to carry the ions. For bulk water this has a long-standing theoretical basis and is used to determine ion diffusivities. The method has also long been used in laboratory investigation to measure diffusivities in porous rocks. It has been shown to give electrical conductivities that agree well with that expected from diffusivity measurements. A number of tests have been made with AC (alternating current) and DC (direct current) to measure resistivities as well as using DC current to conduct ions through rock samples. These tests clearly confirm that the different methods give comparable results

  8. Genetics Home Reference: hereditary diffuse gastric cancer

    Science.gov (United States)

    ... Health Conditions Hereditary diffuse gastric cancer Hereditary diffuse gastric cancer Printable PDF Open All Close All Enable Javascript ... Diffuse Gastric Cancer MedlinePlus Encyclopedia: Gastric Cancer National Cancer ... Option Overview General Information from MedlinePlus ( ...

  9. Improved diffuser for augmenting a wind turbine

    Science.gov (United States)

    Foreman, K.M.; Gilbert, B.L.

    A diffuser for augmenting a wind turbine having means for energizing the boundary layer at several locations along the diffuser walls is improved by the addition of a short collar extending radially outward from the outlet of the diffuser.

  10. What Can Be Done about Antibiotic Resistance?

    Science.gov (United States)

    ... Us General Background: What can be done about Antibiotic Resistance? What can I do? Are antibacterial agents, such as antibacterial soaps, a solution? Are antibiotics regulated? Is there any international action on the ...

  11. Acinetobacter baumannii Isolated from Lebanese Patients: Phenotypes and Genotypes of Resistance, Clonality, and Determinants of Pathogenicity.

    Science.gov (United States)

    Dahdouh, Elias; Hajjar, Micheline; Suarez, Monica; Daoud, Ziad

    2016-01-01

    Introduction: Acinetobacter baumannii is a nosocomial pathogen that usually affects critically ill patients. High mortality rates have been associated with MDR A. baumannii infections. Carbapenem resistance among these isolates is increasing worldwide and is associated with certain International Clones (ICs) and oxacillinases (OXAs). Moreover, this organism possesses a wide range of virulence factors, whose expression is not yet fully understood. In this study, clinical A. baumannii isolates are characterized in terms of antibiotic resistance, mechanisms of carbapenem resistance, clonality, and virulence. Materials and Methods: A. baumannii clinical isolates ( n = 90) where obtained from a tertiary care center in Beirut, Lebanon. API 20NE strips in addition to the amplification of bla OXA-51-like were used for identification. Antibiotic susceptibility testing by disk diffusion was then performed in addition to PCRs for the detection of the most commonly disseminated carbapenemases. Clonality was determined by tri-locus PCR typing and doubling times were determined for isolates with varying susceptibility profiles. Biofilm formation, hemolysis, siderophore production, proteolytic activity, and surface motility was then determined for all the isolates. Statistical analysis was then performed for the determination of associations. Results and Discussion: 81 (90%) of the isolates were resistant to carbapenems. These high rates are similar to other multi-center studies in the country suggesting the need of intervention on a national level. 74 (91.3%) of the carbapenem resistant isolates harbored bla OXA-23-like including two that also harbored bla OXA-24-like . 88.9% of the A. baumannii isolates pertained to ICII and three other international clones were detected, showing the wide dissemination of clones into geographically distinct locations. Virulence profiles were highly diverse and no specific pattern was observed. Nevertheless, an association between motility

  12. The EU agencies’ role in policy diffusion beyond the EU

    DEFF Research Database (Denmark)

    Chatzopoulou, Sevasti

    and health quality within the risk assessment. This paper shows that the EU agencies develop various entrepreneurial methods and that they actively promote policy diffusion beyond the EU through socialisation and learning within international arrangements and collaborations. However, variations......The extensive literature on the EU agencies has mainly focused on their role in the harmonisation and expansion of regulatory standards within the EU. This paper joins this literature and investigates the role of EU agencies in policy diffusion beyond the EU borders. To operationalise this...

  13. Effects on atmospheric diffusion of meterological processes in coastal zones

    International Nuclear Information System (INIS)

    Raynor, G.S.

    1977-01-01

    Meteorological processes in coastal zones differ from those inland because of the surface discontinuity between land and water. The difference in heating between the two surfaces gives rise to sea or lake breeze circulations which can transport pollutants in nongradient directions and recirculate them over source areas. The step change in surface characteristics at the land-water interface also causes formation of internal boundary layers having different transport velocities and diffusion rates than unmodified air upwind or above the boundary. These features require a more extensive measurement program and more versatile diffusion models than at inland sites

  14. The role of external and internal mass transfer in the process of Cu2+ removal by natural mineral sorbents.

    Science.gov (United States)

    Sljivić, M; Smiciklas, I; Plećas, I; Pejanović, S

    2011-07-01

    The kinetics of Cu2+ sorption on to zeolite, clay and diatomite was investigated as a function of initial metal concentrations. For consideration of the mass transfer phenomena, single resistance models based on both film and intraparticle diffusion were tested and compared. The obtained results suggested that the rate-limiting step in Cu2+ sorption strongly depended on the sorbent type, as well as on initial cation concentration. The decrease in external mass transfer coefficients with the increase in initial metal concentrations was in excellent agreement with expressions based on Sherwood and Schmidt dimensionless numbers. The internal diffusivities through zeolite particles were in the range 1.0 x 10(-11) to 1.0 x 10(-13) m2/min, depending on the Cu2+ concentration and the applied theoretical model.

  15. Atmospheric turbulence and diffusion research

    International Nuclear Information System (INIS)

    Hosker, R.P. Jr.

    1993-01-01

    The Atmospheric Turbulence and Diffusion Division (well known in the atmospheric dispersion community as the Atmospheric Turbulence and Diffusion Laboratory, ATDL) is one of several field facilities of NOAAs Air Resources Laboratory, headquartered in Silver Spring, Maryland. The laboratory conducts research on matters of atmospheric diffusion and turbulent exchange, concerning air quality. ATDD focuses attention on the physics of the lower atmosphere, with special emphasis on the processes contributing to atmospheric transport, dispersion, deposition, and air-surface exchange, and on the development of predictive capabilities using the results of this research. Research is directed toward issues of national and global importance related to the missions of DOE, to DOE's Oak Ridge Field Office, and to NOAA. The program is divided into four major projects: plume transport and diffusion in the planetary boundary layer, complex topography, canopy micrometeorology, and air-surface exchange

  16. Diffusion mechanisms in intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Larikov, L N [ANU, Inst. Metallofiziki, Kiev (Ukraine)

    1992-08-01

    Recent research aimed at the identification of the principal mechanisms of diffusion in intermetallics is reviewed. In particular, attention is given to the effect of the type of interatomic bond on the contribution of different mechanisms to diffusion in ordered metallic compounds. Results of an analysis of experimental determinations of diffusion coefficients D(A) and D(B) in binary intermetallics (CuZn, Cu3Sn, AuCd, AgZn, AgMg, InSb, GaSb, AlSb, Fe3Al, FeAl, FeAl3, Ni3Al, Ni3Nb, FeSn, FeSn2, Ni3Sn2, Ni3Sn4, Co3Sn2, CoSn, CoSn2, and CoGa) are presented, and it is shown that the D(A)/D(B) ratio differs substantially for different diffusion mechanisms. 60 refs.

  17. Diffusion of single oxidation pond

    Directory of Open Access Journals (Sweden)

    Song Ruo-Yuan

    2016-01-01

    Full Text Available The hydraulic characteristic of an oxidation pond was studied by the tracer experiment, and an empirical formula of Peclet number was obtained, which can be well applied to the model of plug flow reactor with longitudinal diffusion.

  18. Computational Diffusion MRI : MICCAI Workshop

    CERN Document Server

    Grussu, Francesco; Ning, Lipeng; Tax, Chantal; Veraart, Jelle

    2018-01-01

    This volume presents the latest developments in the highly active and rapidly growing field of diffusion MRI. The reader will find numerous contributions covering a broad range of topics, from the mathematical foundations of the diffusion process and signal generation, to new computational methods and estimation techniques for the in-vivo recovery of microstructural and connectivity features, as well as frontline applications in neuroscience research and clinical practice. These proceedings contain the papers presented at the 2017 MICCAI Workshop on Computational Diffusion MRI (CDMRI’17) held in Québec, Canada on September 10, 2017, sharing new perspectives on the most recent research challenges for those currently working in the field, but also offering a valuable starting point for anyone interested in learning computational techniques in diffusion MRI. This book includes rigorous mathematical derivations, a large number of rich, full-colour visualisations and clinically relevant results. As such, it wil...

  19. Diffusion from cylindrical waste forms

    International Nuclear Information System (INIS)

    Thomas, G.F.

    1985-05-01

    The diffusion of a single component material from a finite cylindrical waste form, initially containing a uniform concentration of the material, is investigated. Under the condition that the cylinder is maintained in a well-stirred bath, expressions for the fractional inventory leached and the leach rate are derived with allowance for the possible permanent immobilization of the diffusant through its decay to a stable product and/or its irreversible reaction with the waste form matrix. The usefulness of the reported results in nuclear waste disposal applications is emphasized. The results reported herein are related to those previously derived at Oak Ridge National Laboratory by Bell and Nestor. A numerical scheme involving the partial decoupling of nested infinite summations and the use of rapidly converging rational approximants is recommended for the efficient implementation of the expressions derived to obtain reliable estimates of the bulk diffusion constant and the rate constant describing the diffusant-waste form interaction from laboratory data

  20. Diffusion coefficient for anomalous transport

    International Nuclear Information System (INIS)

    1986-01-01

    A report on the progress towards the goal of estimating the diffusion coefficient for anomalous transport is given. The gyrokinetic theory is used to identify different time and length scale inherent to the characteristics of plasmas which exhibit anomalous transport