WorldWideScience

Sample records for air-water interactions

  1. Biogenic amine – surfactant interactions at the air-water interface.

    Science.gov (United States)

    Penfold, J; Thomas, R K; Li, P X

    2015-07-01

    The strong interaction between polyamines and anionic surfactants results in pronounced adsorption at the air-water interface and can lead to the formation of layered surface structures. The transition from monolayer adsorption to more complex surface structures depends upon solution pH, and the structure and molecular weight of the polyamine. The effects of manipulating the polyamine molecular weight and structure on the adsorption of the anionic surfactant sodium dodecyl sulphate at the air-water interface are investigated using neutron reflectivity and surface tension, for the biogenic amines putrescine, spermidine and spermine. The results show how changing the number of amine groups and the spacing between the amine groups impacts upon the surface adsorption. At lower pH, 3-7, and for the higher molecular weight polyamines, spermidine and spermine, ordered multilayer structures are observed. For putrescine at all pH and for spermidine and spermine at high pH, monolayer adsorption with enhanced surfactant adsorption compared to the pure surfactant is observed. The data for the biogenic amines, when compared with similar data for the polyamines ethylenediamine, diethylenetriamine and triethylenetetramine, indicate that the spacing between amines groups is more optimal for the formation of ordered surface multilayer structures.

  2. Interfacial Interactions and Nanostructure Changes in DPPG/HD Monolayer at the Air/Water Interface

    Directory of Open Access Journals (Sweden)

    Huaze Zhu

    2015-01-01

    Full Text Available Lung surfactant (LS plays a crucial role in regulating surface tension during normal respiration cycles by decreasing the work associated with lung expansion and therefore decreases the metabolic energy consumed. Monolayer surfactant films composed of a mixture of phospholipids and spreading additives are of optional utility for applications in lung surfactant-based therapies. A simple, minimal model of such a lung surfactant system, composed of 1,2-dipalmitoyl-sn-glycero-3-[phosphor-rac-(1-gylcerol] (DPPG and hexadecanol (HD, was prepared, and the surface pressure-area (π-A isotherms and nanostructure characteristics of the binary mixture were investigated at the air/water interface using a combination of Langmuir-Blodgett (LB and atomic force microscopy (AFM techniques. Based on the regular solution theory, the miscibility and stability of the two components in the monolayer were analyzed in terms of compression modulus (Cs-1 , excess Gibbs free energy (ΔGexcπ , activity coefficients (γ, and interaction parameter (ξ. The results of this paper provide valuable insight into basic thermodynamics and nanostructure of mixed DPPG/HD monolayers; it is helpful to understand the thermodynamic behavior of HD as spreading additive in LS monolayer with a view toward characterizing potential improvements to LS performance brought about by addition of HD to lung phospholipids.

  3. Verification and Validation of Numerical Models for Air/Water Flow on Coastal and Navigation Fluid-Structure Interaction Applications

    Science.gov (United States)

    Kees, C. E.; Farthing, M.; Dimakopoulos, A.; DeLataillade, T.

    2015-12-01

    Performance analysis and optimization of coastal and navigation structures is becoming feasible due to recent improvements in numerical methods for multiphase flows and the steady increase in capacity and availability of high performance computing resources. Now that the concept of fully three-dimensional air/water flow modelling for real world engineering analysis is achieving acceptance by the wider engineering community, it is critical to expand careful comparative studies on verification,validation, benchmarking, and uncertainty quantification for the variety of competing numerical methods that are continuing to evolve. Furthermore, uncertainty still remains about the relevance of secondary processes such as surface tension, air compressibility, air entrainment, and solid phase (structure) modelling so that questions about continuum mechanical theory and mathematical analysis of multiphase flow are still required. Two of the most popular and practical numerical approaches for large-scale engineering analysis are the Volume-Of-Fluid (VOF) and Level Set (LS) approaches. In this work we will present a publically available verification and validation test set for air-water-structure interaction problems as well as computational and physical model results including a hybrid VOF-LS method, traditional VOF methods, and Smoothed Particle Hydrodynamics (SPH) results. The test set repository and test problem formats will also be presented in order to facilitate future comparative studies and reproduction of scientific results.

  4. Interaction between heterogeneous environmental quality domains (air, water, land, socio-demographic and built environment) on preterm birth.

    Science.gov (United States)

    Environmental exposures are often measured individually, though many occur in tandem. To address aggregate exposures, a county-level Environmental Quality Index (EQI) representing five environmental domains (air, water, land, built and sociodemographic) was constructed. Recent st...

  5. The interaction of eugenol with cell membrane models at the air-water interface is modulated by the lipid monolayer composition.

    Science.gov (United States)

    Gonçalves, Giulia E G; de Souza, Fernanda S; Lago, João Henrique G; Caseli, Luciano

    2015-12-01

    Eugenol, a natural phenylpropanoid derivative with possible action in biological surfaces as microbicide, anesthetic and antioxidant, was incorporated in lipid monolayers of selected lipids at the air-water interface, representing cell membrane models. Interaction of eugenol with the lipids dipalmitoylphosphatidylcholine (DPPC), dioctadecyldimethylammonium bromide (DODAB), and dipalmitoylphosphatidylserine (DPPS) could be inferred by means of surface pressure-area isotherms and Polarization-Modulation Reflection-Absorption Spectroscopy. The interaction showed different effects on the different lipids. A higher monolayer expansion was observed for DPPS and DODAB, while more significant effects on the polar groups of the lipids were observed for DPPS and DPPC. These results pointed to the fact that the interaction of eugenol with lipid monolayers at the air-water interface is modulated by the lipid composition, which may be important to comprehend at the molecular level the interaction of this drug with biological surfaces.

  6. A semi-analytical calculation of the electrostatic pair interaction between nonuniformly charged colloidal spheres at an air-water interface

    Science.gov (United States)

    Lian, Zengju

    2016-07-01

    We study the electrostatic pair interaction between two nonuniformly like-charged colloidal spheres trapped in an air-water interface. Under the linear Poisson-Boltzmann approximation, a general form of the electrostatic potential for the system is shown in terms of multipole expansions. After combining the translation-rotation transform of the coordinates with the numerical multipoint collection, we give a semi-analytical result of the electrostatic pair interaction between the colloids. The pair interaction changes quantitatively or even qualitatively with different distributions of the surface charges on the particles. Because of the anisotropic distribution of the surface charge and the asymmetric dielectric medium, the dipole moment of the ion cloud associating with the particle orients diagonally to the air-water interface with an angle α. When the angle is large, the colloids interact repulsively, while they attract each other when the angle is small. The attractive colloids may be "Janus-like" charged and be arranged with some specific configurations. Whatever the repulsions or the attractions, they all decay asymptotically ∝1/d3 (d is the center-center distance of the particles) which is consistent with our general acknowledge. The calculation results also provide an insight of the effect of the ion concentration, particle size, and the total charge of the particle on the pair interaction between the particles.

  7. Surface interactions, thermodynamics and topography of binary monolayers of Insulin with dipalmitoylphosphatidylcholine and 1-palmitoyl-2-oleoylphosphatidylcholine at the air/water interface.

    Science.gov (United States)

    Grasso, E J; Oliveira, R G; Maggio, B

    2016-02-15

    The molecular packing, thermodynamics and surface topography of binary Langmuir monolayers of Insulin and DPPC (dipalmitoylphosphatidylcholine) or POCP (1-palmitoyl-2-oleoylphosphatidylcholine) at the air/water interface on Zn(2+) containing solutions were studied. Miscibility and interactions were ascertained by the variation of surface pressure-mean molecular area isotherms, surface compressional modulus and surface (dipole) potential with the film composition. Brewster Angle Microscopy was used to visualize the surface topography of the monolayers. Below 20mN/m Insulin forms stable homogenous films with DPPC and POPC at all mole fractions studied (except for films with XINS=0.05 at 10mN/m where domain coexistence was observed). Above 20mN/m, a segregation process between mixed phases occurred in all monolayers without squeezing out of individual components. Under compression the films exhibit formation of a viscoelastic or kinetically trapped organization leading to considerable composition-dependent hysteresis under expansion that occurs with entropic-enthalpic compensation. The spontaneously unfavorable interactions of Insulin with DPPC are driven by favorable enthalpy that is overcome by unfavorable entropic ordering; in films with POPC both the enthalpic and entropic effects are unfavorable. The surface topography reveals domain coexistence at relatively high pressure showing a striped appearance. The interactions of Insulin with two major membrane phospholipids induces composition-dependent and long-range changes of the surface organization that ought to be considered in the context of the information-transducing capabilities of the hormone for cell functioning.

  8. Interaction between a growth-hormone releasing hexapeptide and phospholipids spread as monolayers at the air/water interface.

    Science.gov (United States)

    Issaurat, B; Teissié, J

    1988-10-20

    The interaction between a growth-hormone releasing hexapeptide and phospholipids was studied on mixed monolayers models by means of surface fluorescence. When in a monolayer this hexapeptide which contains two tryptophan molecules was observed to fluoresce. Isothermal compression experiments showed that the complex was destroyed upon compression in the case of phosphatidylethanolamine. With phosphatidylglycerol it was observed to be stable but a dramatic reversible decrease in emission was observed at high surface pressure. This is indicative of a reversible change in the organization of the peptide-phospholipid complex. These observations indicate that, in the complex, hydrophobic interactions were weak but electrostatic ones, when present, were strong enough to maintain the GHRP attached to the monolayer and not to destabilize it. The integrity of the lipid monolayer appeared not to be affected by the peptide. PMID:3179304

  9. Conformational analysis of gramicidin-gramicidin interactions at the air/water interface suggests that gramicidin aggregates into tube-like structures similar as found in the gramicidin-induced hexagonal HII phase

    NARCIS (Netherlands)

    Brasserua, R.; Killian, J.A.; Kruijff, B. de; Ruysschaert, J.M.

    1987-01-01

    The energetics of interaction and the type of aggregate structure in lateral assemblies of up to five gramicidin molecules in the β6.3 helical conformation at the air/water interface was calculated using conformational analysis procedures. It was found that within the aggregate two types of gramicid

  10. Conformational analysis of gramicidin-gramicidin interactions at the air/water interface suggests that gramicidin aggregates into tube-like structures similar as found in the gramicidin-induced hexagonal HII phase

    OpenAIRE

    Brasserua, R.; Killian, J A; Kruijff, B. de; Ruysschaert, J M

    1987-01-01

    The energetics of interaction and the type of aggregate structure in lateral assemblies of up to five gramicidin molecules in the β6.3 helical conformation at the air/water interface was calculated using conformational analysis procedures. It was found that within the aggregate two types of gramicidin interaction occur. One leading to a linear organization with a mean interaction energy between monomers of −6 kcal/mol and one in a perpendicular direction leading to a circularly organization w...

  11. Cleaning verification by air/water impingement

    Science.gov (United States)

    Jones, Lisa L.; Littlefield, Maria D.; Melton, Gregory S.; Caimi, Raoul E. B.; Thaxton, Eric A.

    1995-01-01

    This paper will discuss how the Kennedy Space Center intends to perform precision cleaning verification by Air/Water Impingement in lieu of chlorofluorocarbon-113 gravimetric nonvolatile residue analysis (NVR). Test results will be given that demonstrate the effectiveness of the Air/Water system. A brief discussion of the Total Carbon method via the use of a high temperature combustion analyzer will also be given. The necessary equipment for impingement will be shown along with other possible applications of this technology.

  12. Interfacial structure in an air-water planar bubble jet

    Energy Technology Data Exchange (ETDEWEB)

    Sun, X. [Purdue University, School of Nuclear Engineering, West Lafayette, IN (United States); The Ohio State University, Department of Mechanical Engineering, Columbus, OH (United States); Vasavada, S.; Choi, S.W.; Ishii, M. [Purdue University, School of Nuclear Engineering, West Lafayette, IN (United States); Kim, S. [Purdue University, School of Nuclear Engineering, West Lafayette, IN (United States); University of Missouri-Rolla, Nuclear Engineering, Rolla, MO (United States); Beus, S.G. [Bechtel Bettis Inc., West Mifflin, PA (United States)

    2005-04-01

    The objective of the current study is to better understand the interfacial structure and its development in an air-water planar bubble jet, as well as to provide a unique benchmark data set for a 3D thermal-hydraulic analysis code. Both flow visualization and local measurements were performed in three characteristic flow conditions at four elevations along a test section with a cross section of 200 mm in width and 10 mm in gap. A high-speed digital video camera was applied in the flow visualization study to capture the flow structures and bubble interaction phenomena, while a miniaturized four-sensor conductivity probe was used to acquire the time-averaged local void fraction, interfacial velocity, and bubble number frequency. Also, the interfacial area concentration and the averaged bubble Sauter mean diameter were obtained from the local measurements. The lateral bubble transport and bubble interaction mechanisms were clearly demonstrated in the acquired data. (orig.)

  13. Emulsion droplet spreading at air/water interfaces: mechanisms and relevance to the whipping of cream

    NARCIS (Netherlands)

    Hotrum, N.E.

    2004-01-01

    Keywords:emulsion, spreading coefficient, surface tension, emulsifier, whipped cream, dairy foam, partial coalescence In this thesis, the interaction between emulsion droplets and expanding air/water interfaces was investigated. The

  14. Methylglyoxal at the Air-Water Interface

    Science.gov (United States)

    Wren, S. N.; Gordon, B. P.; McWilliams, L.; Valley, N. A.; Richmond, G.

    2014-12-01

    Recently, it has been suggested that aqueous-phase processing of atmospheric α-dicarbonyl compounds such as methylglyoxal (MG) could constitute an important source of secondary organic aerosol (SOA). The uptake of MG to aqueous particles is higher than expected due to the fact that its carbonyl moieties can hydrate to form diols, as well as the fact that MG can undergo aldol condensation reactions to form larger oligomers in solution. MG is known to be surface active but an improved description of its surface behaviour is crucial to understanding MG-SOA formation, in addition to understanding its gas-to-particle partitioning and cloud forming potential. Here, we employ a combined experimental and theoretical approach involving vibrational sum frequency generation spectroscopy (VSFS), surface tensiometry, molecular dynamics simulations, and density functional theory calculations to study MG's surface adsorption, in both the presence and absence of salts. We are particularly interested in determining MG's hydration state at the surface. Our experimental results indicate that MG slowly adsorbs to the air-water interface and strongly perturbs the water structure there. This perturbation is enhanced in the presence of NaCl. Together our experimental and theoretical results suggest that singly-hydrated MG is the dominant form of MG at the surface.

  15. Hydrodynamics of a self-propelled camphor boat at the air-water interface

    Science.gov (United States)

    Akella, Sathish; Singh, Dhiraj; Singh, Ravi; Bandi, Mahesh

    2015-11-01

    A camphor tablet, when placed at the air-water interface undergoes sublimation and camphor vapour spreads radially outwards across the surface due to Marangoni forces. This steady camphor influx from tablet onto the air-water interface is balanced by the camphor outflux due to evaporation. When spontaneous fluctuations in evaporation break the axial symmetry of Marangoni force acting radially outwards, the camphor tablet is propelled like a boat along the water surface. We report experiments on the hydrodynamics of a self-propelled camphor boat at air-water interfaces. We observe three different modes of motion, namely continuous, harmonic and periodic, due to the volatile nature of camphor. We explain these modes in terms of ratio of two time-scales: the time-scale over which viscous forces are dominant over the Marangoni forces (τη) and the time-scale over which Marangoni forces are dominant over the viscous forces (τσ). The continuous, harmonic and periodic motions are observed when τη /τσ ~ 1 , τη /τσ >= 1 and τη /τσ >> 1 respectively. Experimentally, the ratio of the time scales is varied by changing the interfacial tension of the air-water interface using Sodium Dodecyl Sulfate. This work was supported by the Collective Interactions Unit, OIST Graduate University.

  16. Anisotropic diffusion of volatile pollutants at air-water interface

    Institute of Scientific and Technical Information of China (English)

    Li-ping CHEN; Jing-tao CHENG; Guang-fa DENG

    2013-01-01

    The volatile pollutants that spill into natural waters cause water pollution. Air pollution arises from the water pollution because of volatilization. Mass exchange caused by turbulent fluctuation is stronger in the direction normal to the air-water interface than in other directions due to the large density difference between water and air. In order to explore the characteristics of anisotropic diffusion of the volatile pollutants at the air-water interface, the relationship between velocity gradient and mass transfer rate was established to calculate the turbulent mass diffusivity. A second-order accurate smooth transition differencing scheme (STDS) was proposed to guarantee the boundedness for the flow and mass transfer at the air-water interface. Simulations and experiments were performed to study the trichloroethylene (C2HCl3) release. By comparing the anisotropic coupling diffusion model, isotropic coupling diffusion model, and non-coupling diffusion model, the features of the transport of volatile pollutants at the air-water interface were determined. The results show that the anisotropic coupling diffusion model is more accurate than the isotropic coupling diffusion model and non-coupling diffusion model. Mass transfer significantly increases with the increase of the air-water relative velocity at a low relative velocity. However, at a higher relative velocity, an increase in the relative velocity has no effect on mass transfer.

  17. Numerical simulation of air-water two-phase flow over stepped spillways

    Institute of Scientific and Technical Information of China (English)

    CHENG; Xiangju; CHEN; Yongcan

    2006-01-01

    Stepped spillways for significant energy dissipation along the chute have gained interest and popularity among researchers and dam engineers. Due to the complexity of air-water two-phase flow over stepped spillways, the finite volume computational fluid dynamics module of the FLUENT software was used to simulate the main characteristics of the flow. Adopting the RNG k-ε turbulence model, the mixture flow model for air-water two-phase flow was used to simulate the flow field over stepped spillway with the PISO arithmetic technique. The numerical result successfully reproduced the complex flow over a stepped spillway of an experiment case, including the interaction between entrained air bubbles and cavity recirculation in the skimming flow regime, velocity distribution and the pressure profiles on the step surface as well. The result is helpful for understanding the detailed information about energy dissipation over stepped spillways.

  18. Emission to air, water and ground: legislation in Norway

    International Nuclear Information System (INIS)

    The article discusses Norwegian legislation on emission to air, water and ground. Pollution in the sense of the law is defined as ''the addition of solid matter, gas or liquid to air, water or ground''. The concept of pollution is, however, more far-reaching as even noise, light and radiation may be regarded as pollution although these are not discussed. Any pollution is prohibited. But there are two exceptions: commonly accepted pollutions such as arising from wood burning and agriculture, and emissions allowed by special permission from the National State Pollution Control Authority. The article also discusses liability issues

  19. Physical modelling and scale effects of air-water flows on stepped spillways

    Institute of Scientific and Technical Information of China (English)

    CHANSON Hubert; GONZALEZ Carlos A.

    2005-01-01

    During the last three decades, the introduction of new construction materials (e.g. RCC (Roller Compacted Concrete),strengthened gabions) has increased the interest for stepped channels and spillways. However stepped chute hydraulics is not simple, because of different flow regimes and importantly because of very-strong interactions between entrained air and turbulence. In this study, new air-water flow measurements were conducted in two large-size stepped chute facilities with two step heights in each facility to study experimental distortion caused by scale effects and the soundness of result extrapolation to prototypes. Experimental data included distributions of air concentration, air-water flow velocity, bubble frequency, bubble chord length and air-water flow turbulence intensity. For a Froude similitude, the results implied that scale effects were observed in both facilities, although the geometric scaling ratio was only Lr=2 in each case. The selection of the criterion for scale effects is a critical issue. For example, major differences (i.e. scale effects) were observed in terms of bubble chord sizes and turbulence levels although little scale effects were seen in terms of void fraction and velocity distributions. Overall the findings emphasize that physical modelling of stepped chutes based upon a Froude similitude is more sensitive to scale effects than classical smooth-invert chute studies, and this is consistent with basic dimensional analysis developed herein.

  20. Hydrodynamics of a fixed camphor boat at the air-water interface

    Science.gov (United States)

    Singh, Dhiraj; Akella, Sathish; Singh, Ravi; Mandre, Shreyas; Bandi, Mahesh

    2015-11-01

    A camphor tablet, when introduced at the air-water interface undergoes sublimation and the camphor vapour spreads radially outwards across the surface. This radial spreading of camphor is due to Marangoni forces setup by the camphor concentration gradient. We report experiments on the hydrodynamics of this process for a camphor tablet held fixed at the air-water interface. During the initial transient, the time-dependent spread radius R (t) of camphor scales algebraically with time t (R (t) ~t 1 / 2) in agreement with empirical scalings reported for spreading of volatile oils on water surface. But unlike surfactants, the camphor stops spreading when the influx of camphor from the tablet onto the air-water interface is balanced by the outflux of camphor due to evaporation, and a steady-state condition is reached. The spreading camphor however, shears the underlying fluid and sets up bulk convective flow. We explain the coupled steady-state dynamics between the interfacial camphor spreading and bulk convective flow with a boundary layer approximation, supported by experimental evidence. This work was supported by the Collective Interactions Unit, OIST Graduate University.

  1. Forced convection heat transfer to air/water vapor mixtures

    Science.gov (United States)

    Richards, D. R.; Florschuetz, L. W.

    1986-01-01

    Heat transfer coefficients were measured using both dry air and air/water vapor mixtures in the same forced convection cooling test rig (jet array impingement configurations) with mass ratios of water vapor to air up to 0.23. The primary objective was to verify by direct experiment that selected existing methods for evaluation of viscosity and thermal conductivity of air/water vapor mixtures could be used with confidence to predict heat transfer coefficients for such mixtures using as a basis heat transfer data for dry air only. The property evaluation methods deemed most appropriate require as a basis a measured property value at one mixture composition in addition to the property values for the pure components.

  2. Thermodynamic and transport properties of air/water mixtures

    Science.gov (United States)

    Fessler, T. E.

    1981-01-01

    Subroutine WETAIR calculates properties at nearly 1,500 K and 4,500 atmospheres. Necessary inputs are assigned values of combinations of density, pressure, temperature, and entropy. Interpolation of property tables obtains dry air and water (steam) properties, and simple mixing laws calculate properties of air/water mixture. WETAIR is used to test gas turbine engines and components operating in relatively humid air. Program is written in SFTRAN and FORTRAN.

  3. Formation, disruption and mechanical properties of a rigid hydrophobin film at an air-water interface

    Science.gov (United States)

    Walker, Lynn; Kirby, Stephanie; Anna, Shelley; CMU Team

    Hydrophobins are small, globular proteins with distinct hydrophilic and hydrophobic regions that make them extremely surface active. The behavior of hydrophobins at surfaces has raised interest in their potential industrial applications, including use in surface coatings, food foams and emulsions, and as dispersants. Practical use of hydrophobins requires an improved understanding of the interfacial behavior of these proteins, both individually and in the presence of surfactants. Cerato-ulmin (CU) is a hydrophobin that has been shown to strongly stabilize air bubbles and oil droplets through the formation of a persistent protein film at the interface. In this work, we characterize the adsorption behavior of CU at air/water interfaces by measuring the surface tension and interfacial rheology as a function of adsorption time. CU is found to strongly, irreversibly adsorb at air/water interfaces; the magnitude of the dilatational modulus increases with adsorption time and surface pressure, until the CU eventually forms a rigid film. The persistence of this film is tested through the addition of SDS, a strong surfactant, to the bulk. SDS is found to co-adsorb to interfaces pre-coated with a CU film. At high concentrations, the addition of SDS significantly decreases the dilatational modulus, indicating disruption and displacement of CU. These results lend insight into the complex interfacial interactions between hydrophobins and surfactants. Funding from GoMRI.

  4. Study of interfacial area transport and sensitivity analysis for air-water bubbly flow

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.; Sun, X.; Ishii, M.; Beus, S.G.

    2000-09-01

    The interfacial area transport equation applicable to the bubbly flow is presented. The model is evaluated against the data acquired by the state-of-the-art miniaturized double-sensor conductivity probe in an adiabatic air-water co-current vertical test loop under atmospheric pressure condition. In general, a good agreement, within the measurement error of plus/minus 10%, is observed for a wide range in the bubbly flow regime. The sensitivity analysis on the individual particle interaction mechanisms demonstrates the active interactions between the bubbles and highlights the mechanisms playing the dominant role in interfacial area transport. The analysis employing the drift flux model is also performed for the data acquired. Under the given flow conditions, the distribution parameter of 1.076 yields the best fit to the data.

  5. Microscopic dynamics of nanoparticle monolayers at air-water interface.

    Science.gov (United States)

    Bhattacharya, R; Basu, J K

    2013-04-15

    We present results of surface mechanical and particle tracking measurements of nanoparticles trapped at the air-water interface as a function of their areal density. We monitor both the surface pressure (Π) and isothermal compression modulus (ϵ) as well as the dynamics of nanoparticle clusters, using fluorescence confocal microscopy while they are compressed to very high density near the two dimensional close packing density Φ∼0.82. We observe non-monotonic variation in both ϵ and the dynamic heterogeneity, characterized by the dynamical susceptibility χ4 with Φ, in such high density monolayers. We provide insight into the underlying nature of such transitions in close packed high density nanoparticle monolayers in terms of the morphology and flexibility of these soft colloidal particles. We discuss the significance our results in the context of related studies on two dimensional granular or colloidal systems. PMID:23411354

  6. Interfacial structures of confined air-water two-phase bubbly flow

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.; Ishii, M.; Wu, Q.; McCreary, D.; Beus, S.G.

    2000-08-01

    The interfacial structure of the two-phase flows is of great importance in view of theoretical modeling and practical applications. In the present study, the focus is made on obtaining detailed local two-phase parameters in the air-water bubbly flow in a rectangular vertical duct using the double-sensor conductivity probe. The characteristic wall-peak is observed in the profiles of the interracial area concentration and the void fraction. The development of the interfacial area concentration along the axial direction of the flow is studied in view of the interfacial area transport and bubble interactions. The experimental data is compared with the drift flux model with C{sub 0} = 1.35.

  7. Air-water gas exchange by waving vegetation stems

    Science.gov (United States)

    Foster-Martinez, M. R.; Variano, E. A.

    2016-07-01

    Exchange between wetland surface water and the atmosphere is driven by a variety of motions, ranging from rainfall impact to thermal convection and animal locomotion. Here we examine the effect of wind-driven vegetation movement. Wind causes the stems of emergent vegetation to wave back and forth, stirring the water column and facilitating air-water exchange. To understand the magnitude of this effect, a gas transfer velocity (k600 value) was measured via laboratory experiments. Vegetation waving was studied in isolation by mechanically forcing a model canopy to oscillate at a range of frequencies and amplitudes matching those found in the field. The results show that stirring due to vegetation waving produces k600 values from 0.55 cm/h to 1.60 cm/h. The dependence of k600 on waving amplitude and frequency are evident from the laboratory data. These results indicate that vegetation waving has a nonnegligible effect on gas transport; thus, it can contribute to a mechanistic understanding of the fluxes underpinning biogeochemical processes.

  8. 14 CFR 1274.926 - Clean Air-Water Pollution Control Acts.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Clean Air-Water Pollution Control Acts...-Water Pollution Control Acts. Clean Air-Water Pollution Control Acts July 2002 If this cooperative... Violating Facilities” published pursuant to 40 CFR 15.20. By acceptance of a cooperative agreement in...

  9. Structure and dynamics of egg white ovalbumin adsorbed at the air/water interface

    NARCIS (Netherlands)

    Kudryashova, E.V.; Meinders, M.B.J.; Visser, A.J.W.G.; Hoek, A. van; Jongh, H.H.J. de

    2003-01-01

    The molecular properties of egg white ovalbumin adsorbed at the air/water interface were studied using infrared reflection absorption spectroscopy (IRRAS) and time-resolved fluorescence anisotropy (TRFA) techniques. Ovalbumin adsorbed at the air/ water interface adopts a characteristic partially unf

  10. Air-water oxygen exchange in a large whitewater river

    Science.gov (United States)

    Hall, Robert O.; Kennedy, Theodore A.; Rosi-Marshall, Emma J.

    2012-01-01

    Air-water gas exchange governs fluxes of gas into and out of aquatic ecosystems. Knowing this flux is necessary to calculate gas budgets (i.e., O2) to estimate whole-ecosystem metabolism and basin-scale carbon budgets. Empirical data on rates of gas exchange for streams, estuaries, and oceans are readily available. However, there are few data from large rivers and no data from whitewater rapids. We measured gas transfer velocity in the Colorado River, Grand Canyon, as decline in O2 saturation deficit, 7 times in a 28-km segment spanning 7 rapids. The O2 saturation deficit exists because of hypolimnetic discharge from Glen Canyon Dam, located 25 km upriver from Lees Ferry. Gas transfer velocity (k600) increased with slope of the immediate reach. k600 was -1 in flat reaches, while k600 for the steepest rapid ranged 3600-7700 cm h-1, an extremely high value of k600. Using the rate of gas exchange per unit length of water surface elevation (Kdrop, m-1), segment-integrated k600 varied between 74 and 101 cm h-1. Using Kdrop we scaled k600 to the remainder of the Colorado River in Grand Canyon. At the scale corresponding to the segment length where 80% of the O2 exchanged with the atmosphere (mean length = 26.1 km), k600 varied 4.5-fold between 56 and 272 cm h-1 with a mean of 113 cm h-1. Gas transfer velocity for the Colorado River was higher than those from other aquatic ecosystems because of large rapids. Our approach of scaling k600 based on Kdrop allows comparing gas transfer velocity across rivers with spatially heterogeneous morphology.

  11. Adsorption, Ordering, and Local Environments of Surfactant-Encapsulated Polyoxometalate Ions Probed at the Air-Water Interface.

    Science.gov (United States)

    Doughty, Benjamin; Yin, Panchao; Ma, Ying-Zhong

    2016-08-16

    The continued development and application of surfactant-encapsulated polyoxometalates (SEPs) relies on understanding the ordering and organization of species at their interface and how these are impacted by the various local environments to which they are exposed. Here, we report on the equilibrium properties of two common SEPs adsorbed to the air-water interface and probed with surface-specific vibrational sum-frequency generation (SFG) spectroscopy. These results reveal clear shifts in vibrational band positions, the magnitude of which scales with the charge of the SEP core, which is indicative of a static field effect on the surfactant coating and the associated local chemical environment. This static field also induces ordering in surrounding water molecules that is mediated by charge screening via the surface-bound surfactants. From these SFG measurements, we are able to show that Mo132-based SEPs are more polar than Mo72V30 SEPs. Disorder in the surfactant chain packing at the highly curved SEP surfaces is attributed to large conic volumes that can be sampled without interactions with neighboring chains. Measurements of adsorption isotherms yield free energies of adsorption to the air-water interface of -46.8 ± 0.4 and -44.8 ± 1.2 kJ/mol for the Mo132 and Mo72V30 SEPs, respectively, indicating a strong propensity for the fluid surface. The influence of intermolecular interactions on the surface adsorption energies is discussed. PMID:27452922

  12. A CRITICAL ASSESSMENT OF ELEMENTAL MERCURY AIR/WATER EXCHANGE PARTNERS

    Science.gov (United States)

    Although evasion of elemental mercury from aquatic systems can significantly deplete net mercury accumulation resulting from atmospheric deposition, the current ability to model elemental mercury air/water exchange is limited by uncertainties in our understanding of all gaseous a...

  13. Effect of glycyrrhetinic acid on lipid raft model at the air/water interface.

    Science.gov (United States)

    Sakamoto, Seiichi; Uto, Takuhiro; Shoyama, Yukihiro

    2015-02-01

    To investigate an interfacial behavior of the aglycon of glycyrrhizin (GC), glycyrrhetinic acid (GA), with a lipid raft model consisting of equimolar ternary mixtures of N-palmitoyl sphingomyelin (PSM), dioleoylphosphatidylcholine (DOPC), and cholesterol (CHOL), Langmuir monolayer techniques were systematically conducted. Surface pressure (π)-molecular area (A) and surface potential (ΔV)-A isotherms showed that the adsorbed GA at the air/water interface was desorbed into the bulk upon compression of the lipid monolayer. In situ morphological analysis by Brewster angle microscopy and fluorescence microscopy revealed that the raft domains became smaller as the concentrations of GA in the subphase (CGA) increased, suggesting that GA promotes the formation of fluid networks related to various cellular processes via lipid rafts. In addition, ex situ morphological analysis by atomic force microscopy revealed that GA interacts with lipid raft by lying down at the surface. Interestingly, the distinctive striped regions were formed at CGA=5.0 μM. This phenomenon was observed to be induced by the interaction of CHOL with adsorbed GA and is involved in the membrane-disrupting activity of saponin and its aglycon. A quantitative comparison of GA with GC (Sakamoto et al., 2013) revealed that GA interacts more strongly with the raft model than GC in the monolayer state. Various biological activities of GA are known to be stronger than those of GC. This fact allows us to hypothesize that differences in the interactions of GA/GC with the model monolayer correlate to their degree of exertion for numerous activities.

  14. Investigation of adsorption of surfactant at the air-water interface with quantum chemistry method

    Institute of Scientific and Technical Information of China (English)

    CHEN MeiLing; WANG ZhengWu; WANG HaiJun; ZHANG GeXin; TAO FuMing

    2007-01-01

    Density functional theory (DFT) of quantum chemistry was used to optimize the configuration of the anionic surfactant complexes CH3(CH2)7OSO-3(H2O)n (n=0-6) and calculate their molecular frequencies at the B3LYP/6-311+G* level. The interaction of CH3(CH2)7OSO-3 with 1 to 6 water molecules was investigated at the air-water interface with DFT. The results revealed that the hydration shell was formed in the form of H-bond between the hydrophilic group of CH3(CH2)7OSO-3 and 6 waters. The strength of H-bonds belongs to medium. Binding free energy revealed that the hydration shell was stable. The increase of the number of water molecules will cause increases of the total charge of hydrophilic group and S10-O9-C8 bond angle, but decreases of the alkyl chain length and the bond lengths of S10-O11,S10-O12 as well as S10-O13, respectively.

  15. Formation of a Rigid Hydrophobin Film and Disruption by an Anionic Surfactant at an Air/Water Interface.

    Science.gov (United States)

    Kirby, Stephanie M; Zhang, Xujun; Russo, Paul S; Anna, Shelley L; Walker, Lynn M

    2016-06-01

    Hydrophobins are amphiphilic proteins produced by fungi. Cerato-ulmin (CU) is a hydrophobin that has been associated with Dutch elm disease. Like other hydrophobins, CU stabilizes air bubbles and oil droplets through the formation of a persistent protein film at the interface. The behavior of hydrophobins at surfaces has raised interest in their potential applications, including use in surface coatings, food foams, and emulsions and as dispersants. The practical use of hydrophobins requires an improved understanding of the interfacial behavior of these proteins, alone and in the presence of added surfactants. In this study, the adsorption behavior of CU at air/water interfaces is characterized by measuring the surface tension and interfacial rheology as a function of adsorption time. CU is found to adsorb irreversibly at air/water interfaces. The magnitude of the dilatational modulus increases with adsorption time and surface pressure until CU eventually forms a rigid film. The persistence of this film is tested through the sequential addition of strong surfactant sodium dodecyl sulfate (SDS) to the bulk liquid adjacent to the interface. SDS is found to coadsorb to interfaces precoated with a CU film. At high concentrations, the addition of SDS significantly decreases the dilatational modulus, indicating disruption and displacement of CU by SDS. Sequential adsorption results in mixed layers with properties not observed in interfaces generated from complexes formed in the bulk. These results lend insight to the complex interfacial interactions between hydrophobins and surfactants. PMID:27164189

  16. Estimating pH at the Air/Water Interface with a Confocal Fluorescence Microscope.

    Science.gov (United States)

    Yang, Haiya; Imanishi, Yasushi; Harata, Akira

    2015-01-01

    One way to determine the pH at the air/water interface with a confocal fluorescence microscope has been proposed. The relation between the pH at the air/water interface and that in a bulk solution has been formulated in connection with the adsorption equilibrium and the dissociation equilibrium of the dye adsorbed. Rhodamine B (RhB) is used as a surface-active fluorescent pH probe. The corrected fluorescence spectrum of RhB molecules at the air/water interface with the surface density of 1.0 nmol m(-2) level shows pH-dependent shifts representing an acid-base equilibrium. Two ways to determine the unknown acid-base equilibrium constant of RhB molecules at the air/water interface have been discussed. With surface-tension measurements, the adsorption properties, maximum surface density, and adsorption equilibrium constants were estimated for both cationic and zwitterionic forms of RhB molecules at the air/water interface.

  17. Two-phase air-water stratified flow measurement using ultrasonic techniques

    Science.gov (United States)

    Fan, Shiwei; Yan, Tinghu; Yeung, Hoi

    2014-04-01

    In this paper, a time resolved ultrasound system was developed for investigating two-phase air-water stratified flow. The hardware of the system includes a pulsed wave transducer, a pulser/receiver, and a digital oscilloscope. The time domain cross correlation method is used to calculate the velocity profile along ultrasonic beam. The system is able to provide velocities with spatial resolution of around 1mm and the temporal resolution of 200μs. Experiments were carried out on single phase water flow and two-phase air-water stratified flow. For single phase water flow, the flow rates from ultrasound system were compared with those from electromagnetic flow (EM) meter, which showed good agreement. Then, the experiments were conducted on two-phase air-water stratified flow and the results were given. Compared with liquid height measurement from conductance probe, it indicated that the measured velocities were explainable.

  18. Neutron reflectivity measurement of polymer monolayer and brush at the air/water interface

    International Nuclear Information System (INIS)

    We have been studied on amphiphilic polymer monolayer structure at the air/water interface by X-ray and neutron reflectometry. By complemently use of X-ray and neutron reflectometry, we have found (1) the existence of carpet layer in ionic polymer brush in monolayer system and (2) characteristic structural change in polymer/subphase interface. Furthermore, interesting experiment on small ion distribution was carried out by NR with contrast variation method. With our experimental examples, characteristic points in the neutron reflectivity measurement at the air/water interface and further possibility in this research area are discussed. (author)

  19. Investigations of hydraulic operating conditions of air lift pump with three types of air-water mixers

    OpenAIRE

    Kalenik Marek

    2015-01-01

    Investigations of hydraulic operating conditions of air lift pump with three types of air-water mixers. The paper presents the analysis of results of the investigations concerning the influence of various constructive solutions of the air-water mixers on hydraulic operating conditions of the air lift pump. The scope of the investigations encompassed the determination of characteristics of delivery head and delivery rate for three types of air-water mixers applied in the constructed air lift p...

  20. Supramolecular 1-D polymerization of DNA origami through a dynamic process at the 2-dimensionally confined air-water interface.

    Science.gov (United States)

    Yonamine, Yusuke; Cervantes-Salguero, Keitel; Minami, Kosuke; Kawamata, Ibuki; Nakanishi, Waka; Hill, Jonathan P; Murata, Satoshi; Ariga, Katsuhiko

    2016-05-14

    In this study, a Langmuir-Blodgett (LB) system has been utilized for the regulation of polymerization of a DNA origami structure at the air-water interface as a two-dimensionally confined medium, which enables dynamic condensation of DNA origami units through variation of the film area at the macroscopic level (ca. 10-100 cm(2)). DNA origami sheets were conjugated with a cationic lipid (dioctadecyldimethylammonium bromide, 2C18N(+)) by electrostatic interaction and the corresponding LB-film was prepared. By applying dynamic pressure variation through compression-expansion processes, the lipid-modified DNA origami sheets underwent anisotropic polymerization forming a one-dimensionally assembled belt-shaped structure of a high aspect ratio although the thickness of the polymerized DNA origami was maintained at the unimolecular level. This approach opens up a new field of mechanical induction of the self-assembly of DNA origami structures. PMID:27091668

  1. Protonation, Hydrolysis, and Condensation of Mono- and Trifunctional Silanes at the Air/Water Interface

    OpenAIRE

    Britt, David W; Hlady, Vladimir

    1999-01-01

    The protonation, hydrolysis, and condensation kinetics of octadecyldimethylmethoxysilane (OMMS) and octadecyltrimethoxysilane (OTMS) at the air/water interface were investigated using a monolayer trough. OTMS chemical condensation within physically condensed phases was observed in transferred monolayers using fluorescence microscopy. Molecular area increases and decreases attributed to protonation and hydrolysis, respectively, of silane methoxy groups were measured by a surface balance. These...

  2. Molecular details of ovalbumin-pectin complexes at the air/water interface: A spectroscopic study

    NARCIS (Netherlands)

    Kudryashova, E.V.; Visser, A.J.W.G.; Hoek, A. van; Jongh, H.H.J. de

    2007-01-01

    To stabilize air-water interfaces, as in foams, the adsorption of surface-active components is a prerequisite. An approach to controlling the surface activity of proteins is noncovalent complex formation with a polyelectrolyte in the bulk phase. The molecular properties of egg white ovalbumin in a c

  3. Spreading of partially crystallized oil droplets on an air/water interface

    NARCIS (Netherlands)

    Hotrum, N.E.; Cohen Stuart, M.A.; Vliet, van T.; Aken, van G.A.

    2004-01-01

    The influence of crystalline fat on the amount and rate of oil spreading out of emulsion droplets onto either a clean or a protein-covered air/water interface was measured for ß-lactoglobulin stabilized emulsions prepared with either anhydrous milk fat or a blend of hydrogenated palm fat and sunflow

  4. Reactivity of aldehydes at the air-water interface. Insights from molecular dynamics simulations and ab initio calculations.

    Science.gov (United States)

    Martins-Costa, Marilia T C; García-Prieto, Francisco F; Ruiz-López, Manuel F

    2015-02-14

    Understanding the influence of solute-solvent interactions on chemical reactivity has been a subject of intense research in the last few decades. Theoretical studies have focused on bulk solvation phenomena and a variety of models and methods have been developed that are now widely used by both theoreticians and experimentalists. Much less attention has been paid, however, to processes that occur at liquid interfaces despite the important role such interfaces play in chemistry and biology. In this study, we have carried out sequential molecular dynamics simulations and quantum mechanical calculations to analyse the influence of the air-water interface on the reactivity of formaldehyde, acetaldehyde and benzaldehyde, three simple aldehydes of atmospheric interest. The calculated free-energy profiles exhibit a minimum at the interface, where the average reactivity indices may display large solvation effects. The study emphasizes the role of solvation dynamics, which are responsible for large fluctuations of some molecular properties. We also show that the photolysis rate constant of benzaldehyde in the range 290-308 nm increases by one order of magnitude at the surface of a water droplet, from 2.7 × 10(-5) s(-1) in the gas phase to 2.8 × 10(-4) s(-1) at the air-water interface, and we discuss the potential impact of this result on the chemistry of the troposphere. Experimental data in this domain are still scarce and computer simulations like those presented in this work may provide some insights that can be useful to design new experiments.

  5. WETAIR: A computer code for calculating thermodynamic and transport properties of air-water mixtures

    Science.gov (United States)

    Fessler, T. E.

    1979-01-01

    A computer program subroutine, WETAIR, was developed to calculate the thermodynamic and transport properties of air water mixtures. It determines the thermodynamic state from assigned values of temperature and density, pressure and density, temperature and pressure, pressure and entropy, or pressure and enthalpy. The WETAIR calculates the properties of dry air and water (steam) by interpolating to obtain values from property tables. Then it uses simple mixing laws to calculate the properties of air water mixtures. Properties of mixtures with water contents below 40 percent (by mass) can be calculated at temperatures from 273.2 to 1497 K and pressures to 450 MN/sq m. Dry air properties can be calculated at temperatures as low as 150 K. Water properties can be calculated at temperatures to 1747 K and pressures to 100 MN/sq m. The WETAIR is available in both SFTRAN and FORTRAN.

  6. WEXA: exergy analysis for increasing the efficiency of air/water heat pumps - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gasser, L.; Wellig, B.; Hilfiker, K.

    2008-04-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) presents the results of a study at the made by the Engineering and Architecture department at the Lucerne University of Applied Sciences and Arts. The subject of the WEXA study (Waermepumpen-Exergie-Analyse - heat pump exergy analysis) is the analysis of the operation of air/water heat-pumps using exergy analysis methods. The basic thermodynamics of heating systems using heat-pumps is discussed. The exergy analyses and exergy balances for the various components and processes of an air/water heat-pump are presented and discussed. Comparisons are presented for heat-pumps with on/off and continuous control systems for their compressors and fans. The paper is concluded with a collection of appendices on the subject.

  7. Transition from slug to annular flow in horizontal air-water flow

    International Nuclear Information System (INIS)

    The transition from slug to annular flow in horizontal air-water and steam-water flow was investigated. Test sections of 50; 66.6 and 80 mm ID were used. The system pressure was 0.2 and 0.5 MPa in the air-water experiments and 2.5; 5; 7.5 and 10 MPa in the steam-water experiments. For flow pattern detection local impedance probes were used. This method was compared in a part of the experiments with differential pressure and gamma-beam measurements. The flow regime boundary is shifting strongly to smaller values of the superficial gas velocity with increasing pressure. Correlations from literature fit unsatisfactorily the experimental results. A new correlation is presented. (orig.)

  8. Air-water tests in support of LLTR series II Test A-4

    International Nuclear Information System (INIS)

    A series of tests injecting air into a tank of stagnant water was conducted in June 1980 utilizing the GE Plenum Mixing Test Facility in San Jose, California. The test was concerned with investigating the behavior of air jets at a submerged orifice in water over a wide range of flow rates. The main objective was to improve the basic understanding of gas-liquid phenomena (e.g., leak dynamics, gas bubble agglomeration, etc.) in a simulated tube bundle through visualization. The experimental results from these air-water tests will be used as a guide to help select the leak size for LLTR Series II Test A-4 because air-water system is a good simulation of water-sodium mixture

  9. Separating Octadecyltrimethoxysilane Hydrolysis and Condensation at the Air/Water Interface through Addition of Methyl Stearate

    OpenAIRE

    Britt, David W; Hlady, Vladimir

    1999-01-01

    The hydrolysis and condensation of octadecyltrimethoxysilane (OTMS) at the air/water interface were monitored through molecular area changes at a constant surface pressure of 10 mN/m. The onset of condensation was delayed through the addition of methyl stearate (SME) acting as an inert filler molecule. In the absence of SME, complete gelation of OTMS required 30 h, during which time OTMS condensation occurred concomitantly with hydrolysis. In the presence of SME, the OTMS monolayer gelation r...

  10. Differential Effects of Lysophosphatidylcholine on the Adsorption of Phospholipids to an Air/Water Interface

    OpenAIRE

    Biswas, Samares C.; Rananavare, Shankar B.; Hall, Stephen B.

    2006-01-01

    To determine how the hydrophobic surfactant proteins promote insertion of the surfactant lipids into an air/water interface, we measured the effect of lysophosphatidylcholine (LPC) on adsorption. Existing models contend that the proteins function either by disordering the lipids or by stabilizing a negatively curved structure located between the adsorbing vesicle and the interface. Because LPC produces greater disorder but positive curvature, the models predict opposite effects. With vesicles...

  11. Efficient air-water heat pumps for high temperature lift residential heating, including oil migration aspects

    OpenAIRE

    Zehnder, Michele

    2004-01-01

    This thesis presents a system approach with the aim to develop improved concepts for small capacity, high temperature lift air-water heat pumps. These are intended to replace fuel fired heating systems in the residential sector, which leads to a major reduction of the local greenhouse gas emissions. Unfavorable temperature conditions set by the existing heat distribution systems and by the use of atmospheric air, as the only accessible heat source, have to be overcome. The proposed concepts a...

  12. Efficient air-water heat pumps for high temperature lift residential heating, including oil migration aspects

    OpenAIRE

    Zehnder, Michele; Favrat, Daniel

    2005-01-01

    This thesis presents a system approach with the aim to develop improved concepts for small capacity, high temperature lift air-water heat pumps. These are intended to replace fuel fired heating systems in the residential sector, which leads to a major reduction of the local greenhouse gas emissions. Unfavorable temperature conditions set by the existing heat distribution systems and by the use of atmospheric air, as the only accessible heat source, have to be overcome. The proposed concepts a...

  13. Liquid mean velocity and turbulence in a horizontal air-water bubbly flow

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The liquid phase turbulent structure of an air-water bubbly horizontal flow in a circular pipe has been investigated experimentally. Three-dimensional measurements were implemented with two "X" type probes oriented in different planes, and local liquid-phase velocities and turbulent stresses were simultaneously obtained. Systematic measurements were conducted covering a range of local void fraction from 0 to 11.7%. The important experiment results and parametric trends are summarized and discussed.

  14. EXPERIMENTAL STUDY OF AIR-WATER TWO-PHASE FLOW IN PARALLEL HELICALLY COILED PIPES

    OpenAIRE

    Panella, Bruno

    2012-01-01

    The air-water two-phase flow in a 12 mm inner diameter parallel helically coiled pipes is investigated with three different coils diameters. Void fraction, flow rate distribution and two-phase pressure drops along the pipes in the parallel channels are measured. The test two-phase pressure drops are compared with theoretical ones, in terms of multipliers and friction factors. The instabilities arisen during the experimental tests are investigated and are related to the void fraction and flow ...

  15. Demonstration of adaptive optics for mitigating laser propagation through a random air-water interface

    Science.gov (United States)

    Land, Phillip; Majumdar, Arun K.

    2016-05-01

    This paper describes a new concept of mitigating signal distortions caused by random air-water interface using an adaptive optics (AO) system. This is the first time the concept of using an AO for mitigating the effects of distortions caused mainly by a random air-water interface is presented. We have demonstrated the feasibility of correcting the distortions using AO in a laboratory water tank for investigating the propagation effects of a laser beam through an airwater interface. The AO system consisting of a fast steering mirror, deformable mirror, and a Shack-Hartmann Wavefront Sensor for mitigating surface water distortions has a unique way of stabilizing and aiming a laser onto an object underneath the water. Essentially the AO system mathematically takes the complex conjugate of the random phase caused by air-water interface allowing the laser beam to penetrate through the water by cancelling with the complex conjugates. The results show the improvement of a number of metrics including Strehl ratio, a measure of the quality of optical image formation for diffraction limited optical system. These are the first results demonstrating the feasibility of developing a new sensor system such as Laser Doppler Vibrometer (LDV) utilizing AO for mitigating surface water distortions.

  16. Evaluation of a Design Concept for the Combined Air-water Passive Cooling PAFS+

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sung Won; Kwon, Taesoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The APR+ system provides the Passive Auxiliary Feed-water System (PAFS) for the passive cooling capability. However, the current design requirement for working time for the PAFS is about 8 hours only. Thus, current working time of PAFS can not meet the required 72 hours cooling capability for the long term SBO situation. To meet the 72 hours cooling, the pool capacity should be almost 3∼4 times larger than that of current water cooling tank. In order to continue the PAFS operation for 72 hours, a new passive air-water combined cooling system is proposed. This paper provides the feasibility study on the combined passive air-water cooling system. Figure 1 and 2 show the conceptual difference of the PAFS and combined passive air-water cooling system, respectively. Simple performance evaluation of the passive air cooling heat exchanger has been conducted by the MARS calculation. For the postulated FLB scenario, 4800 heat exchanger tubes and 5 m/s air velocity are not sufficient to sustain the PCCT pool level for 72 hour cooling. Further works on the system design and performance enhancing plan are required to fulfill the 72 hours long term passive cooling.

  17. Impact of biogenic amine molecular weight and structure on surfactant adsorption at the air-water interface.

    Science.gov (United States)

    Penfold, Jeffrey; Thomas, Robert K; Li, Peixun

    2016-02-01

    The oligoamines, such as ethylenediamine to pentaethylenetetramine, and the aliphatic biogenic amines, such as putrescine, spermidine and spermine, strongly interact with anionic surfactants, such as sodium dodecylsulfate, SDS. It has been shown that this results in pronounced surfactant adsorption at the air-water interface and the transition from monolayer to multilayer adsorption which depends upon solution pH and oligoamine structure. In the neutron reflectivity, NR, and surface tension, ST, results presented here the role of the oligoamine structure on the adsorption of SDS is investigated more fully using a range of different biogenic amines. The effect of the extent of the intra-molecular spacing between amine groups on the adsorption has been extended by comparing results for cadavarine with putrescine and ethylenediamine. The impact of more complex biogenic amine structures on the adsorption has been investigated with the aromatic phenethylamine, and the heterocyclic amines histamine and melamine. The results provide an important insight into how surfactant adsorption at interfaces can be manipulated by the addition of biogenic amines, and into the role of solution pH and oligoamine structure in modifying the interaction between the surfactant and oligoamine. The results impact greatly upon potential applications and in understanding some of the important biological functions of biogenic amines. PMID:26524255

  18. Impact of biogenic amine molecular weight and structure on surfactant adsorption at the air-water interface.

    Science.gov (United States)

    Penfold, Jeffrey; Thomas, Robert K; Li, Peixun

    2016-02-01

    The oligoamines, such as ethylenediamine to pentaethylenetetramine, and the aliphatic biogenic amines, such as putrescine, spermidine and spermine, strongly interact with anionic surfactants, such as sodium dodecylsulfate, SDS. It has been shown that this results in pronounced surfactant adsorption at the air-water interface and the transition from monolayer to multilayer adsorption which depends upon solution pH and oligoamine structure. In the neutron reflectivity, NR, and surface tension, ST, results presented here the role of the oligoamine structure on the adsorption of SDS is investigated more fully using a range of different biogenic amines. The effect of the extent of the intra-molecular spacing between amine groups on the adsorption has been extended by comparing results for cadavarine with putrescine and ethylenediamine. The impact of more complex biogenic amine structures on the adsorption has been investigated with the aromatic phenethylamine, and the heterocyclic amines histamine and melamine. The results provide an important insight into how surfactant adsorption at interfaces can be manipulated by the addition of biogenic amines, and into the role of solution pH and oligoamine structure in modifying the interaction between the surfactant and oligoamine. The results impact greatly upon potential applications and in understanding some of the important biological functions of biogenic amines.

  19. Modelling the dynamic air-water-sediment coupled fluxes and occurrence of polychlorinated biphenyls in a high altitude lake

    International Nuclear Information System (INIS)

    The BIODEP model in terms of atmosphere-lake interactions was developed. The model was applied to an oligotrophic, dimictic high altitude lake (Lake Redo, Pyrenees) for a range of polychlorinated biphenyl (PCB) congeners. High altitude lakes, which receive their contaminant inputs uniquely from the atmosphere through long-range atmospheric transport, provide ideal controlled environments for the study of the interactions between atmospheric depositional and water column biogeochemical processes. The BIODEP model was able to predict dissolved water concentrations and PCB accumulation in the lake sediment within a factor of 2. This shows that the BIODEP model captures the essential processes driving the sink of POPs in high altitude lakes and that POP occurrence in the lake is driven by direct atmospheric inputs with limited influence from the watershed. An important seasonal variability in water column concentrations is predicted which should have important implications in sampling strategies. Furthermore, it is shown that diffusive air-water exchange dominated the PCB dynamics in the lake, especially for the less chlorinated biphenyls. - A dynamic flux model was able to accurately predict PCB levels

  20. Dust Control with Use of Air-Water Spraying System / Redukcja Zapylenia Powietrza Z Wykorzystaniem Zraszania Powietrzno-Wodnego

    Science.gov (United States)

    Prostański, Dariusz

    2012-12-01

    Results from testing the dust control efficiency, when using air-water spraying system in comparison to the typical water spraying system are presented in the paper. The tests were carried out in conditions of longwall mining and at the places of run-of-mine transportation. Also the results of stand tests of different types of nozzles both for air-water and for water spaying systems carried out at KOMAG's laboratory and in real conditions are presented. The benefits resulting from air-water spraying system have been determined.

  1. Thin film formation at the air-water interface and on solid substrates of soluble axial substituted cis-bis-decanoate tin phthalocyanine

    Energy Technology Data Exchange (ETDEWEB)

    Campos-Teran, Jose, E-mail: jcampos@correo.cua.uam.mx [Departamento de Procesos y Tecnologia, DCNI, Universidad Autonoma Metropolitana-Cuajimalpa, Artificios 40-sexto piso, Col. Hidalgo, D. F., 001120 (Mexico); Garza, Cristina [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, P. O. Box 20-364, D. F., 01000 (Mexico); Beltran, Hiram I. [Departamento de Ciencias Naturales, DCNI, Universidad Autonoma Metropolitana-Cuajimalpa, Artificios 40-sexto piso, Col. Hidalgo, D. F., 001120 (Mexico); Castillo, Rolando [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, P. O. Box 20-364, D. F., 01000 (Mexico)

    2012-01-01

    Herein we study thin films of a recent kind of soluble axial substituted cis-bis-decanoate-tin{sup IV} phthalocyanine (PcSn10) at the air/water interface, which were compressed isothermally and observed with Brewster Angle Microscopy. The air/water interfacial behavior of the films suggests that there are strong interactions among the PcSn10 molecules, which produces multilayers and 3D self-assemblies that prevent the formation of a Langmuir monolayer. Langmuir-Blodgett deposits of these films on both mica (negatively charged) and mild steel (positively charged) surfaces were developed. Information about the morphology of the film was obtained by using atomic force microscopy. We found structural differences in the PcSn10 thin films deposited on both substrates, suggesting that a combination of {pi}-{pi}, {sigma}-{pi} and Van der Waals interactions are the leading factors for the deposition, and consequently, for the control of supramolecular order. Our findings provide insights in the design of phthalocyanine molecules for the development of highly ordered and reproducible thin films.

  2. Role of mixed boundaries on flow in open capillary channels with curved air-water interfaces.

    Science.gov (United States)

    Zheng, Wenjuan; Wang, Lian-Ping; Or, Dani; Lazouskaya, Volha; Jin, Yan

    2012-09-01

    Flow in unsaturated porous media or in engineered microfluidic systems is dominated by capillary and viscous forces. Consequently, flow regimes may differ markedly from conventional flows, reflecting strong interfacial influences on small bodies of flowing liquids. In this work, we visualized liquid transport patterns in open capillary channels with a range of opening sizes from 0.6 to 5.0 mm using laser scanning confocal microscopy combined with fluorescent latex particles (1.0 μm) as tracers at a mean velocity of ∼0.50 mm s(-1). The observed velocity profiles indicate limited mobility at the air-water interface. The application of the Stokes equation with mixed boundary conditions (i.e., no slip on the channel walls and partial slip or shear stress at the air-water interface) clearly illustrates the increasing importance of interfacial shear stress with decreasing channel size. Interfacial shear stress emerges from the velocity gradient from the adjoining no-slip walls to the center where flow is trapped in a region in which capillary forces dominate. In addition, the increased contribution of capillary forces (relative to viscous forces) to flow on the microscale leads to increased interfacial curvature, which, together with interfacial shear stress, affects the velocity distribution and flow pattern (e.g., reverse flow in the contact line region). We found that partial slip, rather than the commonly used stress-free condition, provided a more accurate description of the boundary condition at the confined air-water interface, reflecting the key role that surface/interface effects play in controlling flow behavior on the nanoscale and microscale.

  3. Dynamic Study of Gemini Surfactant and Single-chain Surfactant at Air/Water Interface

    Institute of Scientific and Technical Information of China (English)

    Yi Jian CHEN; Gui Ying XU; Shi Ling YUAN; Hai Ying SUN

    2005-01-01

    Molecular dynamics (MD) simulation are used to study the properties of gemini surfactant of ethyl-α,ω-bis(dodecyldimethylammonium bromide) (C12C2C12) and dodecyltrimethylammonium bromide (DTAB) at the air/water interface, respectively. In the two systems,the surfactant concentrations are both 28 wt. %, and other conditions are also the same. After reaching the thermodynamic equilibrium, the concentration profiles, the radial distributions functions (RDF) and the mean squared displacement (MSD) are investigated. Theresults reveal that the surface activity of C12C2C12 suffactant is higher than DTAB surfactant.

  4. Formation of H-type liquid crystal dimer at air-water interface

    Energy Technology Data Exchange (ETDEWEB)

    Karthik, C., E-mail: karthik.c@pilani.bits-pilani.ac.in; Gupta, Adbhut, E-mail: karthik.c@pilani.bits-pilani.ac.in; Joshi, Aditya, E-mail: karthik.c@pilani.bits-pilani.ac.in; Manjuladevi, V., E-mail: karthik.c@pilani.bits-pilani.ac.in; Gupta, Raj Kumar, E-mail: karthik.c@pilani.bits-pilani.ac.in [Department of Physics, Birla Institute of Technology and Science, Pilani, Rajasthan -333031 (India); Varia, Mahesh C.; Kumar, Sandeep [Raman Research Institute, Sadashivanagar, Bangalore - 560080 (India)

    2014-04-24

    We have formed the Langmuir monolayer of H-shaped Azo linked liquid crystal dimer molecule at the air-water interface. Isocycles of the molecule showed hysteresis suggesting the ir-reversible nature of the monolayer formed. The thin film deposited on the silicon wafer was characterized using Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscopy (FESEM). The images showed uniform domains of the dimer molecule. We propose that these molecules tend to take book shelf configuration in the liquid phase.

  5. Crystalline self-assembly into monolayers of folded oligomers at the air-water interface

    DEFF Research Database (Denmark)

    Lederer, K.; Godt, A.; Howes, P.B.;

    2000-01-01

    Insertion of the 115-bis(ethynylene)benzene unit as a rigid spacer into a linear alkyl chain, thus separating the two resulting stems by 9 Angstrom, induces chain folding at the air-water interface. These folded molecules self-assemble into crystalline monolayers at this interface, with the plane...... and position of the hydrophilic groups in the molecule. The molecules form ribbons with a higher crystal coherence in the direction of stacking between the molecular ribbons, and a lower coherence along the ribbon direction. A similar molecule, but with a spacer unit that imposes a 5 Angstrom separation...

  6. Tuning the Structure and Rheology of Polystyrene Particles at the Air-Water Interface by Varying the pH.

    Science.gov (United States)

    Truzzolillo, Domenico; Sharaf, Hossameldeen; Jonas, Ulrich; Loppinet, Benoit; Vlassopoulos, Dimitris

    2016-07-12

    We form films of carboxylated polystyrene particles (C-PS) at the air-water interface and investigate the effect of subphase pH on their structure and rheology by using a suite of complementary experimental techniques. Our results suggest that electrostatic interactions drive the stability and the structural order of the films. In particular, we show that by increasing the pH of the subphase from 9 up to 13, the films exhibit a gradual transition from solid to liquidlike, which is accompanied by a loss of the long-range order (that characterizes them at lower values of pH). Direct optical visualization of the layers, scanning electron microscopy, and surface pressure isotherms indicate that the particles deposited at the interface form three-dimensional structures involving clusters, with the latter being suppressed and a quasi-2D particle configuration eventually reached at the highest pH values. Evidently, the properties of colloidal films can be tailored significantly by altering the pH of the subphase.

  7. Superposition-additive approach: thermodynamic parameters of clusterization of monosubstituted alkanes at the air/water interface.

    Science.gov (United States)

    Vysotsky, Yu B; Belyaeva, E A; Fomina, E S; Fainerman, V B; Aksenenko, E V; Vollhardt, D; Miller, R

    2011-12-21

    The applicability of the superposition-additive approach for the calculation of the thermodynamic parameters of formation and atomization of conjugate systems, their dipole electric polarisabilities, molecular diamagnetic susceptibilities, π-electron circular currents, as well as for the estimation of the thermodynamic parameters of substituted alkanes, was demonstrated earlier. Now the applicability of the superposition-additive approach for the description of clusterization of fatty alcohols, thioalcohols, amines, carboxylic acids at the air/water interface is studied. Two superposition-additive schemes are used that ensure the maximum superimposition of the graphs of the considered molecular structures including the intermolecular CH-HC interactions within the clusters. The thermodynamic parameters of clusterization are calculated for dimers, trimers and tetramers. The calculations are based on the values of enthalpy, entropy and Gibbs' energy of clusterization calculated earlier using the semiempirical quantum chemical PM3 method. It is shown that the proposed approach is capable of the reproduction with sufficiently enough accuracy of the values calculated previously. PMID:22042000

  8. Spatial Distribution and Air-Water Exchange of Organic Flame Retardants in the Lower Great Lakes.

    Science.gov (United States)

    McDonough, Carrie A; Puggioni, Gavino; Helm, Paul A; Muir, Derek; Lohmann, Rainer

    2016-09-01

    Organic flame retardants (OFRs) such as polybrominated diphenyl ethers (PBDEs) and novel halogenated flame retardants (NHFRs) are ubiquitous, persistent, and bioaccumulative contaminants that have been used in consumer goods to slow combustion. In this study, polyethylene passive samplers (PEs) were deployed throughout the lower Great Lakes (Lake Erie and Lake Ontario) to measure OFRs in air and water, calculate air-water exchange fluxes, and investigate spatial trends. Dissolved Σ12BDE was greatest in Lake Ontario near Toronto (18 pg/L), whereas gaseous Σ12BDE was greatest on the southern shoreline of Lake Erie (11 pg/m(3)). NHFRs were generally below detection limits. Air-water exchange was dominated by absorption of BDEs 47 and 99, ranging from -964 pg/m(2)/day to -30 pg/m(2)/day. Σ12BDE in air and water was significantly correlated with surrounding population density, suggesting that phased-out PBDEs continued to be emitted from population centers along the Great Lakes shoreline in 2012. Correlation with dissolved Σ12BDE was strongest when considering population within 25 km while correlation with gaseous Σ12BDE was strongest when using population within 3 km to the south of each site. Bayesian kriging was used to predict dissolved Σ12BDE over the lakes, illustrating the utility of relatively highly spatially resolved measurements in identifying potential hot spots for future study.

  9. An investigation of channel flow with a smooth air-water interface

    Science.gov (United States)

    Madad, Reza; Elsnab, John; Chin, Cheng; Klewicki, Joseph; Marusic, Ivan

    2015-06-01

    Experiments and numerical simulation are used to investigate fully developed laminar and turbulent channel flow with an air-water interface as the lower boundary condition. Laser Doppler velocimetry measurements of streamwise and wall-normal velocity components are made over a range of Reynolds number based upon channel height and bulk velocity from 1100 to 4300, which encompasses the laminar, transitional and low Reynolds numbers turbulent regimes. The results show that the airflow statistics near the stationary wall are not significantly altered by the air-water moving interface and reflect those found in channel flows. The mean statistics on the water interface side largely exhibit results similar to simulated Poiseuille-Couette flow (PCF) with a solid moving wall. For second-order statistics, however, the simulation and experimental results show some discrepancies near the moving water surface, suggesting that a full two-phase simulation is required. A momentum and energy transport tubes analysis is investigated for laminar and turbulent PCFs. This analysis builds upon the classical notion of a streamtube and indicates that part of the energy from the pressure gradient is transported towards the stationary wall and is dissipated as heat inside the energy tubes, while the remainder is transmitted to the moving wall. For the experiments, the airflow energy is transmitted towards the water to overcome the drag force and drive the water forward; therefore, the amount of energy transferred to the water is higher than the energy transferred to a solid moving wall.

  10. Photosensitized Formation of Secondary Organic Aerosols above the Air/Water Interface.

    Science.gov (United States)

    Bernard, F; Ciuraru, R; Boréave, A; George, C

    2016-08-16

    In this study, we evaluated photosensitized chemistry at the air-sea interface as a source of secondary organic aerosols (SOA). Our results show that, in addition to biogenic emissions, abiotic processes could also be important in the marine boundary layer. Photosensitized production of marine secondary organic aerosol was studied in a custom-built multiphase atmospheric simulation chamber. The experimental chamber contained water, humic acid (1-10 mg L(-1)) as a proxy for dissolved organic matter, and nonanoic acid (0.1-10 mM), a fatty acid proxy which formed an organic film at the air-water interface. Dark secondary reaction with ozone after illumination resulted in SOA particle concentrations in excess of 1000 cm(-3), illustrating the production of unsaturated compounds by chemical reactions at the air-water interface. SOA numbers via photosensitization alone and in the absence of ozone did not exceed background levels. From these results, we derived a dependence of SOA numbers on nonanoic acid surface coverage and dissolved organic matter concentration. We present a discussion on the potential role of the air-sea interface in the production of atmospheric organic aerosol from photosensitized origins. PMID:27434860

  11. Seismic reflection and transmission coefficients at an air-water interface of saturated porous soil

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xin-min; XIA Tang-dai; XU Ping; ZOU Zhen-xuan

    2006-01-01

    Based on the modified Biot's theory of two-phase porous media, a study was presented on seismic reflection and transmission coefficients at an air-water interface of saturated porous soil media. The major differences between air-saturated soils and water-saturated soils were theoretically discussed, and the theoretical formulas of reflection and transmission coefficients at an air-water interface were derived. The characteristics of propagation and attenuation of elastic waves in air-saturated soils were given and the relations among the frequency, the angle of incidence and the reflection, transmission coefficients were analyzed by using numerical methods. Numerical results show that the propagation characteristic of the wave in air-saturated soils is great different from that in water-saturated soils. The frequency and the angle of incidence can have great influences on the reflection and transmission coefficients at interface. Some new cognition about the wave propagation is obtained and the study suggests that we may carefully pay attention to the influence of air on the dynamic analysis of seismic wave.

  12. Air-water gas exchange and CO2 flux in a mangrove-dominated estuary

    Science.gov (United States)

    Ho, David T.; Ferrón, Sara; Engel, Victor C.; Larsen, Laurel G.; Barr, Jordan G.

    2014-01-01

    forests are highly productive ecosystems, but the fate of mangrove-derived carbon remains uncertain. Part of that uncertainty stems from the fact that gas transfer velocities in mangrove-surrounded waters are not well determined, leading to uncertainty in air-water CO2 fluxes. Two SF6 tracer release experiments were conducted to determine gas transfer velocities (k(600) = 8.3 ± 0.4 and 8.1 ± 0.6 cm h-1), along with simultaneous measurements of pCO2 to determine the air-water CO2 fluxes from Shark River, Florida (232.11 ± 23.69 and 171.13 ± 20.28 mmol C m-2 d-1), an estuary within the largest contiguous mangrove forest in North America. The gas transfer velocity results are consistent with turbulent kinetic energy dissipation measurements, indicating a higher rate of turbulence and gas exchange than predicted by commonly used wind speed/gas exchange parameterizations. The results have important implications for carbon fluxes in mangrove ecosystems.

  13. Two-phase air-water flows:Scale effects in physical modeling

    Institute of Scientific and Technical Information of China (English)

    PFISTER Michael; CHANSON Hubert

    2014-01-01

    Physical modeling represents probably the oldest design tool in hydraulic engineering together with analytical approaches. In free surface flows, the similitude based upon a Froude similarity allows for a correct representation of the dominant forces, namely gravity and inertia. As a result fluid flow properties such as the capillary forces and the viscous forces might be incorrectly reproduced, affecting the air entrainment and transport capacity of a high-speed model flow. Small physical models operating under a Froude similitude systematically underestimate the air entrainment rate and air-water interfacial properties. To limit scale effects, minimal values of Reynolds or Weber number have to be respected. The present article summarizes the physical background of such limitations and their combination in terms of the Morton number. Based upon a literature review, the existing limits are presented and discussed, resulting in a series of more conservative recommendations in terms of air concentration scaling. For other air-water flow parameters, the selection of the criteria to assess scale effects is critical because some parameters (e.g., bubble sizes, turbulent scales) can be affected by scale effects, even in relatively large laboratory models.

  14. Air-water gas exchange and CO2 flux in a mangrove-dominated estuary

    Science.gov (United States)

    Ho, David T.; Ferrón, Sara; Engel, Victor C.; Larsen, Laurel G.; Barr, Jordan G.

    2014-01-01

    Mangrove forests are highly productive ecosystems, but the fate of mangrove-derived carbon remains uncertain. Part of that uncertainty stems from the fact that gas transfer velocities in mangrove-surrounded waters are not well determined, leading to uncertainty in air-water CO2 fluxes. Two SF6 tracer release experiments were conducted to determine gas transfer velocities (k(600) = 8.3 ± 0.4 and 8.1 ± 0.6 cm h−1), along with simultaneous measurements of pCO2 to determine the air-water CO2 fluxes from Shark River, Florida (232.11 ± 23.69 and 171.13 ± 20.28 mmol C m−2 d−1), an estuary within the largest contiguous mangrove forest in North America. The gas transfer velocity results are consistent with turbulent kinetic energy dissipation measurements, indicating a higher rate of turbulence and gas exchange than predicted by commonly used wind speed/gas exchange parameterizations. The results have important implications for carbon fluxes in mangrove ecosystems.

  15. Effect of Particulate Contaminants on the Development of Biofilms at Air/Water Interfaces.

    Science.gov (United States)

    Zhang, Zhenhuan; Christopher, Gordon

    2016-03-22

    The development of biofilms at air/water or oil/water interfaces has important ramifications on several applications, but it has received less attention than biofilm formation on solid surfaces. A key difference between the growth of biofilms on solid surfaces versus liquid interfaces is the range of complicated boundary conditions the liquid interface can create that may affect bacteria, as they adsorb onto and grow on the interface. This situation is exacerbated by the existence of complex interfaces in which interfacially adsorbed components can even more greatly affect interfacial boundary conditions. In this work, we present evidence as to how particle-laden interfaces impact biofilm growth at an air/water interface. We find that particles can enhance the rate of growth and final strength of biofilms at liquid interfaces by providing sites of increased adhesive strength for bacteria. The increased adhesion stems from creating localized areas of hydrophobicity that protrude in the water phase and provide sites where bacteria preferentially adhere. This mechanism is found to be primarily controlled by particle composition, with particle size providing a secondary effect. This increased adhesion through interfacial conditions creates biofilms with properties similar to those observed when adhesion is increased through biological means. Because of the generally understood ubiquity of increased bacteria attachment to hydrophobic surfaces, this result has general applicability to pellicle formation for many pellicle-forming bacteria. PMID:26943272

  16. Heat transfer and pressure drop for air-water mixtures in an isoflux vertical annulus

    Energy Technology Data Exchange (ETDEWEB)

    Khattab, M. [Nuclear Research Center, Cairo (Egypt); El-Sallak, M. [Cairo Univ. (Egypt); Morcos, S.M. [Cairo Univ. (Egypt); Salama, A. [Nuclear Research Center, Cairo (Egypt)

    1996-05-01

    Heat transfer and pressure drop in flows of air-water mixtures have been investigated experimentally in an isoflux vertical annulus. The superficial liquid Reynolds number, as a reference parameter, varied from 4500 to 30 000, at different values of gas-to-liquid superficial velocity ratios up to 20 and surface heat fluxes from 50 to 240 kW/m{sup 2}. Enhancement of the two-phase heat transfer coefficient is pronounced particularly at low liquid superficial velocities. The results are correlated and compared with some models of two-phase, two-component flows for air-water mixtures within their range of validity. Satisfactory agreement is obtained from the trend of the experimental data. (orig.) [Deutsch] Waermeuebertragung und Druckabfall in Stroemungen von Luft-Wasser-Gemischen wurden experimentell in einem vertikalen Ringraum untersucht. Der Referenzparameter, die Reynolds`sche Zahl an der Fluessigkeitsoberflaeche, variierte zwischen 4500 und 30 000, das Verhaeltnis der Oberflaechengeschwindigkeiten von Luft und Wasser erreichte Werte bis zu 20, und die Waermestromdichte an der Oberflaeche lag zwischen 50 und 240 kW/m{sup 2}. Der Zweiphasen-Waermeuebertragungskoeffizient nimmt bei kleinen Oberflaechengeschwindigkeiten besonders ausgepraegt zu. Die experimentellen Ergebnisse werden durch bestehende mathematische Modelle von Zweiphasen-Zweikomponenten-Stroemungen befriedigend vorhergesagt. (orig.)

  17. Assessment of MARS for downcomer multi-dimensional thermal hydraulics during LBLOCA reflood using KAERI air-water direct vessel injection tests

    International Nuclear Information System (INIS)

    The MARS code has been assessed for the downcomer multi-dimensional thermal hydraulics during a large break loss-of-coolant accident (LBLOCA) reflood of Korean Next Generation Reactor (KNGR) that adopted an upper direct vessel injection (DVI) design. Direct DVI bypass and downcomer level sweep-out tests carried out at 1/50-scale air-water DVI test facility are simulated to examine the capability of MARS. Test conditions are selected such that they represent typical reflood conditions of KNGR, that is, DVI injection velocities of 1.0 ∼ 1.6 m/sec and air injection velocities of 18.0 ∼ 35.0 m/sec, for single and double DVI configurations. MARS calculation is first adjusted to the experimental DVI film distribution that largely affects air-water interaction in a scaled-down downcomer, then, the code is assessed for the selected test matrix. With some improvements of MARS thermal-hydraulic (T/H) models, it has been demonstrated that the MARS code is capable of simulating the direct DVI bypass and downcomer level sweep-out as well as the multi-dimensional thermal hydraulics in downcomer, where condensation effect is excluded. (authors)

  18. Biogeochemical cycles: Interactions in global metabolism

    Science.gov (United States)

    Moore, B., III; Morowitz, H.; Dastoor, M. N.

    1984-01-01

    A science that chooses the globe as it fundamental biogeophysical unit forces extraordinary conceptual difficulties. The roles of energy flow, matter cycles, carbon cycle, air pollution, global effects, air water interactions are discussed.

  19. Structural and topographical characteristics of adsorbed WPI and monoglyceride mixed monolayers at the air-water interface.

    Science.gov (United States)

    Patino, Juan M Rodríguez; Fernández, Marta Cejudo

    2004-05-25

    In this work we have analyzed the structural and topographical characteristics of mixed monolayers formed by an adsorbed whey protein isolate (WPI) and a spread monoglyceride monolayer (monopalmitin or monoolein) on the previously adsorbed protein film. Measurements of the surface pressure (pi)-area (A) isotherm were obtained at 20 degrees C and at pH 7 for protein-adsorbed films from water in a Wilhelmy-type film balance. Since the surface concentration (1/A) is actually unknown for the adsorbed monolayer, the values were derived by assuming that the A values for adsorbed and spread monolayers were equal at the collapse point of the mixed film. The pi-A isotherm deduced for adsorbed WPI monolayer in this work is practically the same as that obtained directly by spreading. For WPI-monoglyceride mixed films, the pi-A isotherms for adsorbed and spread monolayers at pi higher than the equilibrium surface pressure of WPI are practically coincident, a phenomenon which may be attributed to the protein displacement by the monoglyceride from the interface. At lower surface pressures, WPI and monoglyceride coexist at the interface and the adsorbed and spread pi-A isotherms (i.e., the monolayer structure of the mixed films) are different. Monopalmitin has a higher capacity than monoolein for the displacement of protein from the air-water interface. However, some degree of interactions exists between proteins and monoglycerides and these interactions are higher for adsorbed than for spread films. The topography of the monolayer corroborates these conclusions.

  20. Atmospheric photochemistry at a fatty acid-coated air-water interface.

    Science.gov (United States)

    Rossignol, Stéphanie; Tinel, Liselotte; Bianco, Angelica; Passananti, Monica; Brigante, Marcello; Donaldson, D James; George, Christian

    2016-08-12

    Although fatty acids are believed to be photochemically inert in the actinic region, complex volatile organic compounds are produced during illumination of an air-water interface coated solely with a monolayer of carboxylic acid. When aqueous solutions containing nonanoic acid (NA) at bulk concentrations that give rise to just over a monolayer of NA coverage are illuminated with actinic radiation, saturated and unsaturated aldehydes are seen in the gas phase, and more highly oxygenated products appear in the aqueous phase. This chemistry is probably initiated by triplet-state NA molecules excited by direct absorption of actinic light at the water surface. Because fatty acids-covered interfaces are ubiquitous in the environment, such photochemical processing will have a substantial impact on local ozone and particle formation. PMID:27516601

  1. Developments in the research of air-water two-phase flows in turbomachinery

    International Nuclear Information System (INIS)

    Recently, engineering problems associated with two-phase flows in turbomachinery have become increasingly important in relation to the safety analysis of nuclear reactors or the usage of low quality energy resources; the research on this subject has been promoted. It is a really knotty problem caused by the multiform flow patterns as well as the variety of its applications. However, the mechanics in two-phase machines may involve similar phenomena. In this paper, developments of the research of air-water mixtures in turbomachinery will be briefly reviewed, and the mechanics of two-phase flows in rotating flow fields and the prediction methods of the performance of turbomachinery based on some analytical models are discussed. (author)

  2. Atmospheric photochemistry at a fatty acid-coated air-water interface

    Science.gov (United States)

    Rossignol, Stéphanie; Tinel, Liselotte; Bianco, Angelica; Passananti, Monica; Brigante, Marcello; Donaldson, D. James; George, Christian

    2016-08-01

    Although fatty acids are believed to be photochemically inert in the actinic region, complex volatile organic compounds are produced during illumination of an air-water interface coated solely with a monolayer of carboxylic acid. When aqueous solutions containing nonanoic acid (NA) at bulk concentrations that give rise to just over a monolayer of NA coverage are illuminated with actinic radiation, saturated and unsaturated aldehydes are seen in the gas phase, and more highly oxygenated products appear in the aqueous phase. This chemistry is probably initiated by triplet-state NA molecules excited by direct absorption of actinic light at the water surface. Because fatty acids-covered interfaces are ubiquitous in the environment, such photochemical processing will have a substantial impact on local ozone and particle formation.

  3. Correlation reflectance spectroscopy of heterogeneous silver nanoparticle films upon compression at the air/water interface

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Gassin, Gaelle [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Harfouch, Yara El [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Benichou, Emmanuel [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Bachelier, Guillaume [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Russier-Antoine, Isabelle [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Jonin, Christian [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Roux, Stephane [Laboratoire de Physico-Chimie des Materiaux Luminescents, UMR CNRS 5260, Universite Claude Bernard Lyon 1, Batiment Claude Louis Berthollet, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Tillement, Olivier [Laboratoire de Physico-Chimie des Materiaux Luminescents, UMR CNRS 5260, Universite Claude Bernard Lyon 1, Batiment Claude Louis Berthollet, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France); Brevet, Pierre-Francois [Laboratoire de Spectrometrie Ionique et Moleculaire, UMR CNRS 5579, Universite Claude Bernard Lyon 1, Batiment Alfred Kastler, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne cedex (France)

    2008-02-06

    Alkanethiol passivated silver nanoparticles were spread at an air/water interface to form a single monolayer film. The surface pressure isotherms and the UV-visible absorbance spectra of the film were recorded as a function of compression, whereas the dynamic behaviour was investigated by reflectance correlation spectroscopy. The film is shown to be inhomogeneous, formed by domains of particles separated by large areas of low particle density. Two distinct motions were observed: Brownian diffusion of the domains and their translational flow due to convection. From the characteristic diffusion time of the domains, and using a Stokes-Einstein analysis, the domain size is determined as a function of surface compression. The domains start to form and grow once a fixed average particle density is reached. Above this density threshold, the attractive van der Waals forces between the particles are dominating compared with the repulsion forces due to the alkanethiol chains.

  4. Mechanical tuning of molecular machines for nucleotide recognition at the air-water interface

    Directory of Open Access Journals (Sweden)

    Shinoda Satoshi

    2011-01-01

    Full Text Available Abstract Molecular machines embedded in a Langmuir monolayer at the air-water interface can be operated by application of lateral pressure. As part of the challenge associated with versatile sensing of biologically important substances, we here demonstrate discrimination of nucleotides by applying a cholesterol-armed-triazacyclononane host molecule. This molecular machine can discriminate ribonucleotides based on a twofold to tenfold difference in binding constants under optimized conditions including accompanying ions in the subphase and lateral surface pressures of its Langmuir monolayer. The concept of mechanical tuning of the host structure for optimization of molecular recognition should become a novel methodology in bio-related nanotechnology as an alternative to traditional strategies based on increasingly complex and inconvenient molecular design strategies.

  5. A Comparative Cycle and Refrigerant Simulation Procedure Applied on Air-Water Heat Pumps

    DEFF Research Database (Denmark)

    Mader, Gunda; Palm, Björn; Elmegaard, Brian

    2012-01-01

    A vapor compression heat pump absorbs heat from the environment at a low temperature level and rejects heat at a high temperature level. The bigger the difference between the two temperature levels the more challenging is it to gain high energy efficiency with a basic cycle layout as found in most...... small capacity heat pump applications today. Many of the applicable refrigerants also reach their technical limits regarding low vapor pressure for very low source temperatures and high discharge temperatures for high sink temperatures. These issues are especially manifest for air-water heat pumps. Many...... alternative cycle setups and refrigerants are known to improve the energy efficiency of a vapor compression cycle and reduce discharge temperatures. However not all of them are feasible for small capacity heat pumps from a cost and complexity point of view. This paper presents a novel numerical approach...

  6. Two-dimensional Insect Flight on an Air-Water Interface is a Chaotic Oscillator

    CERN Document Server

    Mukundarajan, Haripriya; Prakash, Manu

    2014-01-01

    Two-dimensional flapping wing insect flight on an air-water interface provides a successful foraging strategy to explore an ecological niche on the surface of a pond. However, the complex interplay of surface tension, aerodynamic forces, biomechanics and neural control that enables two-dimensional flight is unknown. Here we report the discovery of two-dimensional flight in the waterlily beetle Galerucella nymphaeae, which is the fastest reported propulsion mode for an insect on a fluid interface. Using kinematics derived from high-speed videography coupled with analytical models, we demonstrate that two-dimensional flight is a chaotic interfacial oscillator, thus significantly constraining the possible range of flight parameters. Discovery of this complex dynamics in two-dimensional flight on time scales similar to neural responses indicates the challenge of evolving active flight control on a fluid interface.

  7. Patterns of a slow air-water flow in a semispherical container

    DEFF Research Database (Denmark)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A.;

    2016-01-01

    This numerical study analyzes the development of eddies in a slow steady axisymmetric air-water flow in a sealed semispherical container, driven by a rotating top disk. As the water height, Hw, increases, new flow cells emerge in both water and air. First, an eddy emerges near the axis......-bottom intersection. Then this eddy expands and reaches the interface, inducing a new cell in the air flow. This cell appears as a thin near-axis layer which then expands and occupies the entire air domain. As the disk rotation intensifies at Hw = 0.8, the new air cell shrinks to the axis and disappears. The bulk...... water circulation becomes separated from the interface by a thin layer of water counter-circulation. These changes in the flow topology occur due to (a) competing effects of the air meridional flow and swirl, which drive meridional motions of opposite directions in water, and (b) feedback of water flow...

  8. Thermodynamics of iodide adsorption at the instantaneous air-water interface

    Science.gov (United States)

    Stern, Abraham C.; Baer, Marcel D.; Mundy, Christopher J.; Tobias, Douglas J.

    2013-03-01

    We performed molecular dynamics simulations using both polarizable and non-polarizable force fields to study the adsorption of iodide to the air-water interface. A novel aspect of our analysis is that the progress of ion adsorption is measured as the distance from the instantaneous interface, which is defined by a coarse-graining scheme proposed recently by Willard and Chandler ["Instantaneous liquid interfaces," J. Phys. Chem. B 114, 1954-1958 (2010), 10.1021/jp909219k]. Referring structural and thermodynamic quantities to the instantaneous interface unmasks molecular-scale details that are obscured by thermal fluctuations when the same quantities are referred to an average measure of the position of the interface, such as the Gibbs dividing surface. Our results suggest that an ion adsorbed at the interface resides primarily in the topmost water layer, and the interfacial location of the ion is favored by enthalpy and opposed by entropy.

  9. Corrosion of copper-based materials in gamma-irradiated air/water vapor systems

    International Nuclear Information System (INIS)

    Experiments were performed to investigate the atmospheric corrosion of copper-based materials in an irradiated air/water vapor system. The three materials investigated were oxygen-free copper (CDA-102), 7% aluminum-bronze (CDA-613), and 70-30 cupronickel (CDA-715). To support the corrosion studies, a number of irradiation studies were performed to characterize the gas phase radiation chemistry of the system. Both copper oxide and nitrate phases were identified as corrosion products depending on the dose rate, humidity and temperature. Uniform corrosion rates increased with temperature, humidity, and dose rate. A clear tie between the radiolytic products generated in the gas phase and the corrosion observed was established

  10. Anomalous spreading behaviour of polyethyleneglycoldistearate monolayers at air/water interface

    Indian Academy of Sciences (India)

    S John Collins; Aruna Dhathathreyan; T Ramasami

    2001-04-01

    Spreading behaviour of the dimeric surfactant polyethyleneglycoldistearate (PEGDS) monolayer at air/water interface has been studied using surface pressure-area ( -) isotherms as a function of temperature. The isotherms show a plateau suggesting a transition between a liquid expanded (LE) and a condensed state. The condensed state possibly arises due to nucleation and growth of multilayers from the monolayer. Isobaric measurements of both - and - at constant area show transitions at = 295 K. These plots suggest a melting followed by formation of condensed microcrystallites. Structure optimization carried out using various angles of orientation of the alkyl tails with respect to the backbone in PEGDS reveals tilt transitions of the tails in different states which can be related to the packing behaviour seen in the isotherms. Optical microscopy has been used to confirm the structures in these states.

  11. Mercury Exchange at the Air-Water-Soil Interface: An Overview of Methods

    Directory of Open Access Journals (Sweden)

    Fengman Fang

    2002-01-01

    Full Text Available An attempt is made to assess the present knowledge about the methods of determining mercury (Hg exchange at the air-water-soil interface during the past 20 years. Methods determining processes of wet and dry removal/deposition of atmospheric Hg to aquatic and terrestrial ecosystems, as well as methods determining Hg emission fluxes to the atmosphere from natural surfaces (soil and water are discussed. On the basis of the impressive advances that have been made in the areas relating to Hg exchange among air-soil-water interfaces, we analyzed existing problems and shortcomings in our current knowledge. In addition, some important fields worth further research are discussed and proposed.

  12. A criterion for the onset of slugging in horizontal stratified air-water countercurrent flow

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Moon-Hyun; Lee, Byung-Ryung; Kim, Yang-Seok [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)] [and others

    1995-09-01

    This paper presents an experimental and theoretical investigation of wave height and transition criterion from wavy to slug flow in horizontal air-water countercurrent stratified flow conditions. A theoretical formula for the wave height in a stratified wavy flow regime has been developed using the concept of total energy balance over a wave crest to consider the shear stress acting on the interface of two fluids. From the limiting condition of the formula for the wave height, a necessary criterion for transition from a stratified wavy flow to a slug flow has been derived. A series of experiments have been conducted changing the non-dimensional water depth and the flow rates of air in a horizontal pipe and a duct. Comparisons between the measured data and the predictions of the present theory show that the agreement is within {plus_minus}8%.

  13. Countercurrent air/water and steam/water flow above a perforated plate. Report for October 1978-October 1979

    International Nuclear Information System (INIS)

    The perforated plate weeping phenomena have been studied in both air/water and steam/cold water systems. The air/water experiment is designed to investigate the effect of geometric factors of the perforated plate on the rate of weeping. A new dimensionless flow rate in the form of H star is suggested. The data obtained are successfully correlated by this H star scaling in the conventional flooding equation. The steam/cold water experiment is concentrated on locating the boundary between weeping and no weeping. The effects of water subcooling, water inlet flow rate, and position of water spray are investigated. Depending on the combination of these factors, several types of weeping were observed. The data obtained at high water spray position can be related to the air/water flooding correlation by replacing the stream flow rate to an effective stream flow rate, which is determined by the mixing efficiency above the plate

  14. Simulating Urban Tree Effects on Air, Water, and Heat Pollution Mitigation: iTree-Hydro Model

    Science.gov (United States)

    Yang, Y.; Endreny, T. A.; Nowak, D.

    2011-12-01

    Urban and suburban development changes land surface thermal, radiative, porous, and roughness properties and pollutant loading rates, with the combined effect leading to increased air, water, and heat pollution (e.g., urban heat islands). In this research we present the USDA Forest Service urban forest ecosystem and hydrology model, iTree Eco and Hydro, used to analyze how tree cover can deliver valuable ecosystem services to mitigate air, water, and heat pollution. Air pollution mitigation is simulated by dry deposition processes based on detected pollutant levels for CO, NO2, SO2, O3 and atmospheric stability and leaf area indices. Water quality mitigation is simulated with event mean concentration loading algorithms for N, P, metals, and TSS, and by green infrastructure pollutant filtering algorithms that consider flow path dispersal areas. Urban cooling considers direct shading and indirect evapotranspiration. Spatially distributed estimates of hourly tree evapotranspiration during the growing season are used to estimate human thermal comfort. Two main factors regulating evapotranspiration are soil moisture and canopy radiation. Spatial variation of soil moisture is represented by a modified urban topographic index and radiation for each tree is modified by considering aspect, slope and shade from surrounding buildings or hills. We compare the urban cooling algorithms used in iTree-Hydro with the urban canopy and land surface physics schemes used in the Weather Research and Forecasting model. We conclude by identifying biophysical feedbacks between tree-modulated air and water quality environmental services and how these may respond to urban heating and cooling. Improvements to this iTree model are intended to assist managers identify valuable tree services for urban living.

  15. Precision Cleaning Verification of Fluid Components by Air/Water Impingement and Total Carbon Analysis

    Science.gov (United States)

    Barile, Ronald G.; Fogarty, Chris; Cantrell, Chris; Melton, Gregory S.

    1995-01-01

    NASA personnel at Kennedy Space Center's Material Science Laboratory have developed new environmentally sound precision cleaning and verification techniques for systems and components found at the center. This technology is required to replace existing methods traditionally employing CFC-113. The new patent-pending technique of precision cleaning verification is for large components of cryogenic fluid systems. These are stainless steel, sand cast valve bodies with internal surface areas ranging from 0.2 to 0.9 m(exp 2). Extrapolation of this technique to components of even larger sizes (by orders of magnitude) is planned. Currently, the verification process is completely manual. In the new technique, a high velocity, low volume water stream impacts the part to be verified. This process is referred to as Breathing Air/Water Impingement and forms the basis for the Impingement Verification System (IVS). The system is unique in that a gas stream is used to accelerate the water droplets to high speeds. Water is injected into the gas stream in a small, continuous amount. The air/water mixture is then passed through a converging-diverging nozzle where the gas is accelerated to supersonic velocities. These droplets impart sufficient energy to the precision cleaned surface to place non-volatile residue (NVR) contaminants into suspension in the water. The sample water is collected and its NVR level is determined by total organic carbon (TOC) analysis at 880 C. The TOC, in ppm carbon, is used to establish the NVR level. A correlation between the present gravimetric CFC-113 NVR and the IVS NVR is found from experimental sensitivity factors measured for various contaminants. The sensitivity has the units of ppm of carbon per mg-ft(exp 2) of contaminant. In this paper, the equipment is described and data are presented showing the development of the sensitivity factors from a test set including four NVR's impinged from witness plates of 0.05 to 0.75 m(exp 2).

  16. Catechol oxidation by ozone and hydroxyl radicals at the air-water interface.

    Science.gov (United States)

    Pillar, Elizabeth A; Camm, Robert C; Guzman, Marcelo I

    2014-12-16

    Anthropogenic emissions of aromatic hydrocarbons promptly react with hydroxyl radicals undergoing oxidation to form phenols and polyphenols (e.g., catechol) typically identified in the complex mixture of humic-like substances (HULIS). Because further processing of polyphenols in secondary organic aerosols (SOA) can continue mediated by a mechanism of ozonolysis at interfaces, a better understanding about how these reactions proceed at the air-water interface is needed. This work shows how catechol, a molecular probe of the oxygenated aromatic hydrocarbons present in SOA, can contribute interfacial reactive species that enhance the production of HULIS under atmospheric conditions. Reactive semiquinone radicals are quickly produced upon the encounter of 40 ppbv-6.0 ppmv O3(g) with microdroplets containing [catechol] = 1-150 μM. While the previous pathway results in the instantaneous formation of mono- and polyhydroxylated aromatic rings (PHA) and chromophoric mono- and polyhydroxylated quinones (PHQ), a different channel produces oxo- and dicarboxylic acids of low molecular weight (LMW). The cleavage of catechol occurs at the 1,2 carbon-carbon bond at the air-water interface through the formation of (1) an ozonide intermediate, (2) a hydroperoxide, and (3) cis,cis-muconic acid. However, variable [catechol] and [O3(g)] can affect the ratio of the primary products (cis,cis-muconic acid and trihydroxybenzenes) and higher order products observed (PHA, PHQ, and LMW oxo- and dicarboxylic acids). Secondary processing is confirmed by mass spectrometry, showing the production of crotonic, maleinaldehydic, maleic, glyoxylic, and oxalic acids. The proposed pathway can contribute precursors to aqueous SOA (AqSOA) formation, converting aromatic hydrocarbons into polyfunctional species widely found in tropospheric aerosols with light-absorbing brown carbon. PMID:25423038

  17. Air/water oxidative desulfurization of coal and sulfur-containing compounds

    Science.gov (United States)

    Warzinski, R. P.; Freidman, S.; LaCount, R. B.

    1981-02-01

    Air/water Oxydesulfurization has been demonstrated in autoclave experiments at the Pittsburgh Energy Technology Center for various coals representative of the major U. S. coal basins. The applicability at present of this treatment for producing an environmentally acceptable coal has been restricted by recently proposed SO2 emission standards for utility boilers. The product would, however, be attractive to the many smaller industrial coal users who cannot afford to operate and maintain flue gas desulfurization systems. It is also possible that the utility industry could realize a benefit by using chemically cleaned coal with partial flue gas scrubbing. The higher cost of the cleaned coal would be offset by the reduction in capital and operating costs resulting from decreased FGD requirements. The susceptibility of sulfur in coal to oxidative removal varies with the nature of the sulfur-containing species. The inorganic sulfur compounds, primarily pyrite, marcasite, and iron sulfate, are more amenable to treatment than the organically bound sulfur which exhibits varying degrees of resistance depending on its chemical environment. Air/water Oxydesulfurization consistently removes in excess of 90 percent of the pyritic sulfur; the extent and efficiency of organic sulfur removal however, depends on the type of coal and severity of treatment used. In general, the organic sulfur of the higher rank coals exhibits more resistance to treatment than that of the lower rank coals; however, the accompanying heating value is greater for the latter. Similar treatment of sulfur-containing model compounds further illustrates the relative susceptibilities of different chemical species to oxidation. Application of these data to the understanding of the complex chemistry involved in the treatment of coal is a preliminary step toward improving the efficiency of Oxydesulfurization.

  18. The AirWaterGas Teacher Professional Development Program: Lessons Learned by Pairing Scientists and Teachers to Develop Curriculum on Global Climate Change and Regional Unconventional Oil and Gas Development

    Science.gov (United States)

    Gardiner, L. S.; Hatheway, B.; Rogers, J. D.; Casey, J. G.; Lackey, G.; Birdsell, D.; Brown, K.; Polmear, M.; Capps, S.; Rosenblum, J.; Sitterley, K.; Hafich, K. A.; Hannigan, M.; Knight, D.

    2015-12-01

    The AirWaterGas Teacher Professional Development Program, run by the UCAR Center for Science Education, brought together scientists and secondary science teachers in a yearlong program culminating in the development of curriculum related to the impacts of unconventional oil and gas development. Graduate students and research scientists taught about their research area and its relationship to oil and gas throughout three online courses during the 2015-16 school year, during which teachers and scientists engaged in active online discussions. Topics covered included climate change, oil and gas infrastructure, air quality, water quality, public health, and practices and policies relating to oil and gas development. Building upon their initial online interactions and a face-to-face meeting in March, teachers were paired with appropriate AirWaterGas team members as science advisors during a month-long residency in Boulder, Colorado. During the residency, graduate student scientists provided resources and feedback as teachers developed curriculum projects in collaboration with each other and UCAR science educators. Additionally, teachers and AirWaterGas researchers shared experiences on an oil and gas well site tour, and a short course on drilling methods with a drilling rig simulator. Here, we share lessons learned from both sides of the aisle, including initial results from program assessment conducted with the participating teachers.

  19. Co-current air-water flow in downward sloping pipes: Transport of capacity reducing gas pockets in wastewater mains

    NARCIS (Netherlands)

    Pothof, I.W.M.

    2011-01-01

    Air-water flow is an undesired condition in many systems for the transportation of water or wastewater. Air in storm water tunnels may get trapped and negatively affect the system. Air pockets in hydropower tunnels or sewers may cause blow-back events and inadmissible pressure spikes. Water pipes an

  20. Characterization of predominantly hydrophobic poly(styrene)-poly(ethylene oxide) copolymers at air/water and cyclohexane/water interfaces

    International Nuclear Information System (INIS)

    Interfacial tension measurements are employed to explore the spreading behavior of predominantly hydrophobic poly(styrene)--poly(ethylene oxide), PS-PEO, diblock copolymers at air/water and cyclohexane/water interfaces. Two copolymers with 7%- and 15.5%-PEO are examined in this study. The former is expected to have a PS block limiting area in air roughly equal to the limiting PEO pancake area, whereas the latter is expected to have a limiting PS block area in air approximately 3 times smaller than the limiting PEO pancake area. At the air/water interface, the 7%-PEO copolymer does not spread well, which is attributed to interference from the hydrophobic PS block. In contrast, the 7%-PEO copolymer spreads well at the cyclohexane/water interface, producing an isotherm with a terminating mean molecular area 3 times smaller than that obtained at the air/water interface. The 15.5%-PEO copolymer spreads well at both the air/water ad cyclohexane/water interfaces due to less interference from the smaller hydrophobic PS block. These observations are compared to compression isotherms, and the results are discussed in terms of the solvating nature of the adjacent cyclohexane phase for the PS block

  1. THIN-FILM BEHAVIOR OF POLY(METHYL METHACRYLATES) .1. MONOLAYERS AT THE AIR-WATER-INTERFACE

    NARCIS (Netherlands)

    BRINKHUIS, RHG; SCHOUTEN, AJ

    1991-01-01

    The monolayer behavior of PMMA of varying tacticities at the air-water interface was studied. A difference in lateral cohesive energy is argued to be responsible for the fact that the pressure area isotherms of isotactic PMMA deviate strongly from those of syndiotactic PMMA. At low surface pressures

  2. Thin-Film Behavior of Poly(methyl methacrylates). 1. Monolayers at the Air-Water Interface

    NARCIS (Netherlands)

    Brinkhuis, R.H.G.; Schouten, A.J.

    1991-01-01

    The monolayer behavior of PMMA of varying tacticities at the air-water interface was studied. A difference in lateral cohesive energy is argued to be responsible for the fact that the pressure area isotherms of isotactic PMMA deviate strongly from those of syndiotactic PMMA. At low surface pressures

  3. Protein Exposed Hydrophobicity Reduces the Kinetic Barrier for Adsorption of Ovalbumin to the Air-Water Interface

    NARCIS (Netherlands)

    Wierenga, P.A.; Meinders, M.B.J.; Egmond, M.R.; Voragen, F.A.G.J.; Jongh, H.H.J. de

    2003-01-01

    Using native and caprylated ovalbumin, the role of exposed hydrophobicity on the kinetics of protein adsorption to the air - water interface is studied. First, changes in the chemical properties of the protein upon caprylation were characterized followed by measurement of the changes in adsorption k

  4. Protein exposed hydrophobicity reduces the kinetic barrier for adsoption of ovalbumin to the air-water interface.

    NARCIS (Netherlands)

    Wierenga, P.A.; Meinders, M.B.J.; Egmond, M.R.; Voragen, A.G.J.

    2003-01-01

    Using native and caprylated ovalbumin, the role of exposed hydrophobicity on the kinetics of protein adsorption to the air-water interface is studied. First, changes in the chemical properties of the protein upon caprylation were characterized followed by measurement of the changes in adsorption kin

  5. Pollution: A Selected Bibliography of U.S. Government Publications on Air, Water, and Land Pollution 1965-1970.

    Science.gov (United States)

    Kiraldi, Louis, Comp.; Burk, Janet L., Comp.

    Materials on environmental pollution published by the various offices of the federal government are presented in this select bibliography. Limited in scope to publications on air, water, and land pollution, the document is designed to serve teachers and researchers working in the field of environmental problems who wish reference to public…

  6. Comparison of the dilational behaviour of adsorbed milk proteins at the air-water and oil-water interfaces.

    NARCIS (Netherlands)

    Williams, A.; Prins, A.

    1996-01-01

    The interfacial dilational properties of two milk proteins, β-casein and β-lactoglobulin, have been compared at the air-water and paraffin oil-water interfaces. The measurements were performed as a function of bulk protein concentration using a modified Langmuir trough technique at a frequency of 0.

  7. epi-Fluorescence imaging at the air-water interface of fibrillization of bovine serum albumin and human insulin.

    Science.gov (United States)

    Sessions, Kristen; Sacks, Stuart; Li, Shanghao; Leblanc, Roger M

    2014-08-18

    Protein fibrillization is associated with many devastating neurodegenerative diseases. This process has been studied using spectroscopic and microscopic methods. In this study, epi-fluorescence at the air-water interface was developed as an innovative technique for observing fibrillization of bovine serum albumin and human insulin. PMID:24976597

  8. Ultrasonic methodology measurement of two-phase (air-water) flows in cooling systems of nuclear reactor

    International Nuclear Information System (INIS)

    An ultrasonic methodology is proposed for the measurement for two phase (air-water) flow parameters. Ultrasonic backscattered signals were used to analyze the following parameters: average number of bubbles, interfacial area and void fraction. The results show a strong correlation between the parameters and the ultrasonic power signal obtained. (author)

  9. Chiral Discrimination in N-(O, O-dialkyl)phosphoamino Acid Monolayers at the Air-water Interface

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, chiral discrimination in N-(O,O-dialkyl)phosphoamino acid monolayers at the air/water interface was studied and it was revealed that the D:L=1:1 racemic monolayer of N-(O, O-dihexadecyl)phosphoalanine is packed more densely in solid phase while shows a higher LE to LC transition pressure than the enantiomeric ones.

  10. Experimental investigation on the droplet entrainment from interfacial waves in air-water horizontal stratified flow

    International Nuclear Information System (INIS)

    It was mainly due to the fact that droplet entrainment affects the Peak Cladding Temperature (PCT) of the nuclear fuel rod in the Postulated accident conditions of NPP. Recently, droplet entrainment in the horizontally arranged primary piping system for the NPP is of interest because it affects directly the steam binding phenomena in the steam generators. Pan and Hanratty correlation is the only applicable one for the droplet entrainment rate model for horizontal flow. Moreover, there are no efforts for the model development on the basis of the droplet entrainment principal and physics phenomena. More recently, Korea Atomic Energy Research Institute (KAERI) proposed a new mechanistic droplet generation model applicable in the horizontal pipe for the SPACE code. However, constitutive relations in this new model require three model coefficients which have not yet been decided. The purpose of present work is determining three model coefficients by visualization experiment. For these model coefficients, the major physical parameters regarding the interfacial disturbance wave should be measured in this experiments. There are the wave slope, liquid fraction, wave hypotenuse length, wave velocity, wave frequency, and wavelength in the major physical parameters. The experiment was conducted at an air water horizontal rectangular channel with the PIV system. In this study, the experimental conditions were stratified-way flow during the droplet generation. Three coefficients were determined based on several data related to the interfacial wave. Additionally, we manufactured the parallel wire conductance probe to measure the fluctuating water level over time, and compared the wave height measured by the parallel wire conductance probe and image processing from images taken by high speed camera. Experimental investigation was performed for droplet entrainment from phase interface wave in an air-water stratified flow. In the experiments, we measured major physical parameters

  11. Experimental investigation on the droplet entrainment from interfacial waves in air-water horizontal stratified flow

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Byeong Geon; Yun, Byong Jo [Pusan national Univ., Pusan (Korea, Republic of); Kim, Kyoung Du [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    It was mainly due to the fact that droplet entrainment affects the Peak Cladding Temperature (PCT) of the nuclear fuel rod in the Postulated accident conditions of NPP. Recently, droplet entrainment in the horizontally arranged primary piping system for the NPP is of interest because it affects directly the steam binding phenomena in the steam generators. Pan and Hanratty correlation is the only applicable one for the droplet entrainment rate model for horizontal flow. Moreover, there are no efforts for the model development on the basis of the droplet entrainment principal and physics phenomena. More recently, Korea Atomic Energy Research Institute (KAERI) proposed a new mechanistic droplet generation model applicable in the horizontal pipe for the SPACE code. However, constitutive relations in this new model require three model coefficients which have not yet been decided. The purpose of present work is determining three model coefficients by visualization experiment. For these model coefficients, the major physical parameters regarding the interfacial disturbance wave should be measured in this experiments. There are the wave slope, liquid fraction, wave hypotenuse length, wave velocity, wave frequency, and wavelength in the major physical parameters. The experiment was conducted at an air water horizontal rectangular channel with the PIV system. In this study, the experimental conditions were stratified-way flow during the droplet generation. Three coefficients were determined based on several data related to the interfacial wave. Additionally, we manufactured the parallel wire conductance probe to measure the fluctuating water level over time, and compared the wave height measured by the parallel wire conductance probe and image processing from images taken by high speed camera. Experimental investigation was performed for droplet entrainment from phase interface wave in an air-water stratified flow. In the experiments, we measured major physical parameters

  12. Calibration of Dissolved Noble Gas Mass Spectrometric Measurements by an Air-Water Equilibration System

    Science.gov (United States)

    Hillegonds, Darren; Matsumoto, Takuya; Jaklitsch, Manfred; Han, Liang-Feng; Klaus, Philipp; Wassenaar, Leonard; Aggarwal, Pradeep

    2013-04-01

    Precise measurements by mass spectrometry of dissolved noble gases (He, Ar, Ne, Kr, Xe) in water samples require careful calibration against laboratory standards with known concentrations. Currently, air pipettes are used for day-to-day calibrations, making estimation of overall analytical uncertainties for dissolved noble gas measurements in water difficult. Air equilibrated water (AEW) is often used as a matrix-equivalent laboratory standard for dissolved gases in groundwater, because of the well-known and constant fractions of noble gases in the atmosphere. AEW standards, however, are only useful if the temperature and pressure of the gas-water equilibrium can be controlled and measured precisely (i.e., to better than 0.5%); contamination and partial sample degassing must also be prevented during sampling. Here we present the details of a new custom air-water equilibration system which consists of an insulated 600 liter tank filled with deionized water, held isothermally at a precise target temperature (water in the tank are monitored continually, as are atmospheric pressure and air temperature in the laboratory. Different noble gas concentration standards can be reliably produced by accurately controlling the water temperature of the equilibration system. Equilibration characteristics and reproducibility of this system for production of copper tubes containing known amounts of noble gases will be presented.

  13. Field observations of turbulent dissipation rate profiles immediately below the air-water interface

    Science.gov (United States)

    Wang, Binbin; Liao, Qian

    2016-06-01

    Near surface profiles of turbulence immediately below the air-water interface were measured with a free-floating Particle Image Velocimetry (PIV) system on Lake Michigan. The surface-following configuration allowed the system to measure the statistics of the aqueous-side turbulence in the topmost layer immediately below the water surface (z≈0˜15 cm, z points downward with 0 at the interface). Profiles of turbulent dissipation rate (ɛ) were investigated under a variety of wind and wave conditions. Various methods were applied to estimate the dissipation rate. Results suggest that these methods yield consistent dissipation rate profiles with reasonable scattering. In general, the dissipation rate decreases from the water surface following a power law relation in the top layer, ɛ˜z-0.7, i.e., the slope of the decrease was lower than that predicted by the wall turbulence theory, and the dissipation was considerably higher in the top layer for cases with higher wave ages. The measured dissipation rate profiles collapse when they were normalized with the wave speed, wave height, water-side friction velocity, and the wave age. This scaling suggests that the enhanced turbulence may be attributed to the additional source of turbulent kinetic energy (TKE) at the "skin layer" (likely due to micro-breaking), and its downward transport in the water column.

  14. Ultrafast Reorientational Dynamics of Leucine at the Air-Water Interface.

    Science.gov (United States)

    Donovan, Michael A; Yimer, Yeneneh Y; Pfaendtner, Jim; Backus, Ellen H G; Bonn, Mischa; Weidner, Tobias

    2016-04-27

    Ultrafast dynamics of protein side chains are involved in important biological processes such as ligand binding, protein folding, and hydration. In addition, the dynamics of a side chain can report on local environments within proteins. While protein side chain dynamics have been probed for proteins in solution with nuclear magnetic resonance and infrared methods for decades, information about side chain dynamics at interfaces is lacking. At the same time, the dynamics and motions of side chains can be particularly important for interfacial binding and protein-driven surface manipulation. We here demonstrate that ultrafast reorientation dynamics of leucine amino acids at interfaces can be recorded in situ and in real time using polarization- and time-resolved pump-probe sum frequency generation (SFG). Combined with molecular dynamics simulations, time-resolved SFG was used to probe the reorientation of the isopropyl methyl groups of l-leucine at the air-water interface. The data show that the methyl units reorient diffusively at an in plane rate of Dφ = 0.07 rad(2)/ps and an out of plane rate of Dθ = 0.05 rad(2)/ps. PMID:27057584

  15. Bifurcations of a creeping air-water flow in a conical container

    Science.gov (United States)

    Balci, Adnan; Brøns, Morten; Herrada, Miguel A.; Shtern, Vladimir N.

    2016-10-01

    This numerical study describes the eddy emergence and transformations in a slow steady axisymmetric air-water flow, driven by a rotating top disk in a vertical conical container. As water height Hw and cone half-angle β vary, numerous flow metamorphoses occur. They are investigated for β =30°, 45°, and 60°. For small Hw, the air flow is multi-cellular with clockwise meridional circulation near the disk. The air flow becomes one cellular as Hw exceeds a threshold depending on β . For all β , the water flow has an unbounded number of eddies whose size and strength diminish as the cone apex is approached. As the water level becomes close to the disk, the outmost water eddy with clockwise meridional circulation expands, reaches the interface, and induces a thin layer with anticlockwise circulation in the air. Then this layer expands and occupies the entire air domain. The physical reasons for the flow transformations are provided. The results are of fundamental interest and can be relevant for aerial bioreactors.

  16. Surface shear rheology of WPI-monoglyceride mixed films spread at the air-water interface.

    Science.gov (United States)

    Carrera Sánchez, Cecilio; Rodríguez Patino, Juan M

    2004-07-01

    Surface shear viscosity of food emulsifiers may contribute appreciably to the long-term stability of food dispersions (emulsions and foams). In this work we have analyzed the structural, topographical, and shear characteristics of a whey protein isolate (WPI) and monoglyceride (monopalmitin and monoolein) mixed films spread on the air-water interface at pH 7 and at 20 degrees C. The surface shear viscosity (etas) depend on the surface pressure and on the composition of the mixed film. The surface shear viscosity varies greatly with the surface pressure. In general, the greater the surface pressure, the greater are the values of etas. The values of etas for the mixed WPI-monoolein monolayer were more than one order of magnitude lower than those for a WPI-monopalmitin mixed film, especially at the higher surface pressures. At higher surface pressures, collapsed WPI residues may be displaced from the interface by monoglyceride molecules with important repercussions on the shear characteristics of the mixed films. A shear-induced change in the topography and a segregation between domains of the film forming components were also observed. The displacement of the WPI by the monoglycerides is facilitates under shear conditions, especially for WPI-monoolein mixed films.

  17. Air-water simulation of phenomena of corium dispersion in direct containment heating

    International Nuclear Information System (INIS)

    The present research at Purdue addresses the corium dispersion during the direct containment heating in reactor severe accident. The degree of corium dispersion has not only the strongest parametric effect on the containment pressurization but also has the highest uncertainty in predicting it. In view of this, a separate effect test program on the corium dispersion mechanisms in the reactor cavity and the subcompartment trapping mechanisms was initiated in spring of 1992 at Purdue under the direction of the Nuclear Regulatory Commission. Four major objectives of this corium dispersion study are: (1) to perform a detailed scaling study using the newly proposed step-by-step integral scaling method, then to evaluate existing models for entrainment, particle size and trapping, (2) to perform carefully designed simulation experiments using water-air and woods metal-air in a 1/10 linear scale model, (3) to develop reliable mechanistic models and correlations for corium dispersions, which can be used to predict corium jet disintegration, entrainment, drop size, liquid film carry over, and subcompartment trapping, and (4) to use the models to perform stand along calculations for typical prototypic conditions. The combination of water-air and woods metal-air as working fluid will give a unique data base over broad parametric ranges which can be used together with the integral test results to develop reliable models and correlations. The results of the experiments that were conducted using air-water are presented

  18. Effects of thermodynamics parameters on mass transfer of volatile pollutants at air-water interface

    Directory of Open Access Journals (Sweden)

    Li-ping Chen

    2015-07-01

    Full Text Available A transient three-dimensional coupling model based on the compressible volume of fluid (VOF method was developed to simulate the transport of volatile pollutants at the air-water interface. VOF is a numerical technique for locating and tracking the free surface of water flow. The relationships between Henry’s constant, thermodynamics parameters, and the enlarged topological index were proposed for nonstandard conditions. A series of experiments and numerical simulations were performed to study the transport of benzene and carbinol. The simulation results agreed with the experimental results. Temperature had no effect on mass transfer of pollutants with low transfer free energy and high Henry’s constant. The temporal and spatial distribution of pollutants with high transfer free energy and low Henry’s constant was affected by temperature. The total enthalpy and total transfer free energy increased significantly with temperature, with significant fluctuations at low temperatures. The total enthalpy and total transfer free energy increased steadily without fluctuation at high temperatures.

  19. A comparison of recent methods for modelling mercury fluxes at the air-water interface

    Directory of Open Access Journals (Sweden)

    Fantozzi L.

    2013-04-01

    Full Text Available The atmospheric pathway of the global mercury flux is known to be the primary source of mercury contamination to most threatened aquatic ecosystems. Notwithstanding, the emission of mercury from surface water to the atmosphere is as much as 50% of total annual emissions of this metal into the atmosphere. In recent years, much effort has been made in theoretical and experimental researches to quantify the total mass flux of mercury to the atmosphere. In this study the most recent atmospheric modelling methods and the information obtained from them are presented and compared using experimental data collected during the Oceanographic Campaign Fenice 2011 (25 October – 8 November 2011, performed on board the Research Vessel (RV Urania of the CNR in the framework of the MEDOCEANOR ongoing program. A strategy for future numerical model development is proposed which is intended to gain a better knowledge of the long-term effects of meteo-climatic drivers on mercury evasional processes, and would provide key information on gaseous Hg exchange rates at the air-water interface.

  20. Hydration, Orientation, and Conformation of Methylglyoxal at the Air-Water Interface.

    Science.gov (United States)

    Wren, Sumi N; Gordon, Brittany P; Valley, Nicholas A; McWilliams, Laura E; Richmond, Geraldine L

    2015-06-18

    Aqueous-phase processing of methylglyoxal (MG) has been suggested to constitute an important source of secondary organic aerosol (SOA). The uptake of MG to aqueous particles is higher than expected because its carbonyl moieties can hydrate to form geminal diols, as well as because MG and its hydration products can undergo aldol condensation reactions to form larger oligomers in solution. MG is known to be surface active, but an improved description of its surface behavior is crucial to understanding MG-SOA formation. These studies investigate MG adsorption, focusing on its hydration state at the air-water interface, using a combined experimental and theoretical approach that involves vibrational sum frequency spectroscopy, molecular dynamics simulations, and density functional theory calculations. Together, the experimental and theoretical data show that MG exists predominantly in a singly hydrated state (diol) at the interface, with a diol-tetrol ratio at the surface higher than that for the bulk. In addition to exhibiting a strong surface activity, we find that MG significantly perturbs the water structure at the interface. The results have implications for understanding the atmospheric fate of methylglyoxal. PMID:25989368

  1. Substrateless Welding of Self-Assembled Silver Nanowires at Air/Water Interface.

    Science.gov (United States)

    Hu, Hang; Wang, Zhongyong; Ye, Qinxian; He, Jiaqing; Nie, Xiao; He, Gufeng; Song, Chengyi; Shang, Wen; Wu, Jianbo; Tao, Peng; Deng, Tao

    2016-08-10

    Integrating connected silver nanowire networks with flexible polymers has appeared as a popular way to prepare flexible electronics. To reduce the contact resistance and enhance the connectivity between silver nanowires, various welding techniques have been developed. Herein, rather than welding on solid supporting substrates, which often requires complicated transferring operations and also may pose damage to heat-sensitive substrates, we report an alternative approach to prepare easily transferrable conductive networks through welding of self-assembled silver nanowires at the air/water interface using plasmonic heating. The intriguing welding behavior of partially aligned silver nanowires was analyzed with combined experimental observation and theoretical modeling. The underlying water not only physically supports the assembled silver nanowires but also buffers potential overheating during the welding process, thereby enabling effective welding within a broad range of illumination power density and illumination duration. The welded networks could be directly integrated with PDMS substrates to prepare high-performance stable flexible heaters that are stretchable, bendable, and can be easily patterned to explore selective heating applications. PMID:27437907

  2. Interfacial behaviors of PMMA-PEO block copolymers at the air/water interface

    Institute of Scientific and Technical Information of China (English)

    CHENG Caixia; JIAO Tifeng; TANG Rupei; LIU Minghua; XI Fu

    2005-01-01

    Diblock copolymer of PMMA291-b-PEO114 and triblock copolymer of PMMA120-b- PEO227-b-PMMA120 were synthesized and their interfacial properties at the air-water interface were investigated, where both blocks of polyethylene oxide (PEO) and poly(methyl methacrylate) (PMMA) are surface active but the former is soluble in water while the latter is not. Both the block copolymers could form monolayers with two obvious transition regions. The first transition point is around 10 mN/m, which could be assigned to the pancake-brush change of the PEO chains. The other is around 18 mN/m, which could be ascribed to the condensed packing of PMMA. The surface morphological changes during the compression of the Langmuir monolayers are investigated by using the AFM and SEM methods for the films deposited at different surface pressure or molecular areas. At a lower surface pressure, a typical morphology of PEO-con- taining lipopolymers is observed. Upon compression, sphere-dominant morphologies were observed. While the diblock copolymer is easy to folding, the triblock copolymer is in favor of formation of circular domains through vesiculation.

  3. Time-resolved Fast Neutron Radiography of Air-water Two-phase Flows

    Science.gov (United States)

    Zboray, Robert; Dangendorf, Volker; Mor, Ilan; Tittelmeier, Kai; Bromberger, Benjamin; Prasser, Horst-Michael

    Neutron imaging, in general, is a useful technique for visualizing low-Z materials (such as water or plastics) obscured by high-Z materials. However, when significant amounts of both materials are present and full-bodied samples have to be examined, cold and thermal neutrons rapidly reach their applicability limit as the samples become opaque. In such cases one can benefit from the high penetrating power of fast neutrons. In this work we demonstrate the feasibility of time-resolved, fast neutron radiography of generic air-water two-phase flows in a 1.5 cm thick flow channel with Aluminum walls and rectangular cross section. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany. Exposure times down to 3.33 ms have been achieved at reasonable image quality and acceptable motion artifacts. Different two-phase flow regimes such as bubbly slug and churn flows have been examined. Two-phase flow parameters like the volumetric gas fraction, bubble size and bubble velocities have been measured.

  4. Reliable quantification of phthalates in environmental matrices (air, water, sludge, sediment and soil): a review.

    Science.gov (United States)

    Net, Sopheak; Delmont, Anne; Sempéré, Richard; Paluselli, Andrea; Ouddane, Baghdad

    2015-05-15

    Because of their widespread application, phthalates or phthalic acid esters (PAEs) are ubiquitous in the environment. Their presence has attracted considerable attention due to their potential impacts on ecosystem functioning and on public health, so their quantification has become a necessity. Various extraction procedures as well as gas/liquid chromatography and mass spectrometry detection techniques are found as suitable for reliable detection of such compounds. However, PAEs are ubiquitous in the laboratory environment including ambient air, reagents, sampling equipment, and various analytical devices, that induces difficult analysis of real samples with a low PAE background. Therefore, accurate PAE analysis in environmental matrices is a challenging task. This paper reviews the extensive literature data on the techniques for PAE quantification in natural media. Sampling, sample extraction/pretreatment and detection for quantifying PAEs in different environmental matrices (air, water, sludge, sediment and soil) have been reviewed and compared. The concept of "green analytical chemistry" for PAE determination is also discussed. Moreover useful information about the material preparation and the procedures of quality control and quality assurance are presented to overcome the problem of sample contamination and these encountered due to matrix effects in order to avoid overestimating PAE concentrations in the environment. PMID:25723871

  5. Structure of air-water two-phase flow in helically coiled tubes

    International Nuclear Information System (INIS)

    Air-water two-phase flow in helically coiled tubes is investigated experimentally to elucidate the effects of centrifugal acceleration on the flow regime map and the spatial and the temporal flow structure distribution. Three kinds of test tubes with 20 mm inner diameters including a straight tube are used to compare the turbulent flow structure. Superficial velocities up to 6 m/s are tested so that the centrifugal Froude number covers a range from 0 to 3. The interfacial structure is photographed from two directions by a high-speed video system with synchronized measurement of local pressure fluctuations. The results reveal that the flow transition line alters due to centrifugal force acting on the liquid phase in the tube. In particular, the bubbly flow regime is narrowed significantly. The pressure fluctuation amplitude gets large relatively to the average pressure loss as void fraction increases. The frequency spectra of the pressure fluctuation have plural peaks in the case of strong curvature, implying that the periodicity of slugging two-phase flow is collapsed by an internal secondary flow activated inside the liquid phase. Moreover, under large Froude number conditions, the substantial velocity of the gas phase that biases to the inner side of the helical coil is slower than the total superficial velocity because the liquid flow is allowed to pass through the outer side and so resembles a radial stratified flow

  6. Spread Films of Human Serum Albumin at the Air-Water Interface: Optimization, Morphology, and Durability.

    Science.gov (United States)

    Campbell, Richard A; Ang, Joo Chuan; Sebastiani, Federica; Tummino, Andrea; White, John W

    2015-12-22

    It has been known for almost one hundred years that a lower surface tension can be achieved at the air-water interface by spreading protein from a concentrated solution than by adsorption from an equivalent total bulk concentration. Nevertheless, the factors that control this nonequilibrium process have not been fully understood. In the present work, we apply ellipsometry, neutron reflectometry, X-ray reflectometry, and Brewster angle microscopy to elaborate the surface loading of human serum albumin in terms of both the macroscopic film morphology and the spreading dynamics. We show that the dominant contribution to the surface loading mechanism is the Marangoni spreading of protein from the bulk of the droplets rather than the direct transfer of their surface films. The films can be spread on a dilute subphase if the concentration of the spreading solution is sufficient; if not, dissolution of the protein occurs, and only a textured adsorbed layer slowly forms. The morphology of the spread protein films comprises an extended network with regions of less textured material or gaps. Further, mechanical cycling of the surface area of the spread films anneals the network into a membrane that approach constant compressibility and has increased durability. Our work provides a new perspective on an old problem in colloid and interface science. The scope for optimization of the surface loading mechanism in a range of systems leading to its exploitation in deposition-based technologies in the future is discussed. PMID:26607026

  7. Air - water temperature relationships in the trout streams of southeastern Minnesota’s carbonate - sandstone landscape

    Science.gov (United States)

    Krider, Lori A.; Magner, Joseph A.; Perry, Jim; Vondracek, Bruce C.; Ferrington, Leonard C.

    2013-01-01

    Carbonate-sandstone geology in southeastern Minnesota creates a heterogeneous landscape of springs, seeps, and sinkholes that supply groundwater into streams. Air temperatures are effective predictors of water temperature in surface-water dominated streams. However, no published work investigates the relationship between air and water temperatures in groundwater-fed streams (GWFS) across watersheds. We used simple linear regressions to examine weekly air-water temperature relationships for 40 GWFS in southeastern Minnesota. A 40-stream, composite linear regression model has a slope of 0.38, an intercept of 6.63, and R2 of 0.83. The regression models for GWFS have lower slopes and higher intercepts in comparison to surface-water dominated streams. Regression models for streams with high R2 values offer promise for use as predictive tools for future climate conditions. Climate change is expected to alter the thermal regime of groundwater-fed systems, but will do so at a slower rate than surface-water dominated systems. A regression model of intercept vs. slope can be used to identify streams for which water temperatures are more meteorologically than groundwater controlled, and thus more vulnerable to climate change. Such relationships can be used to guide restoration vs. management strategies to protect trout streams.

  8. Interfacial friction factors for air-water co-current stratified flow in inclined channels

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ki Yong; No, Hee Cheon [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    The interfacial shear stress is experimentally investigated for co-current air-water stratified flow in inclined rectangular channels having a length of 1854mm, width of 120 mm and height of 40mm at almost atmospheric pressure. Experiments are carried out in several inclinations from 0 deg up to 10 deg. The local film thickness and the wave height are measured at three locations, i.e., L/H = 8,23, and 40. According to the inclination angle, the experimental data are categorized into two groups; nearly horizontal data group (0 deg {<=} {theta} {<=} 0.7 deg), and inclined channel data group (0.7 deg {<=} {theta} {<=} 10 deg ). Experimental observations for nearly horizontal data group show that the flow is not fully developed due to the water level gradient and the hydraulic jump within the channel. For the inclined channel data group, a dimensionless wave height, {Delta}h/h, is empirically correlated in terms of Re{sub G} and h/H. A modified root-mean-square wave height is proposed to consider the effects of the interfacial and wave propagation velocities. It is found that an equivalent roughness has a linear relationship with the modified root-mean-square wave height and its relationship is independent of the inclination. 10 refs., 6 figs., 1 tab. (Author)

  9. 20 Years of Air-Water Gas Exchange Observations for Pesticides in the Western Arctic Ocean.

    Science.gov (United States)

    Jantunen, Liisa M; Wong, Fiona; Gawor, Anya; Kylin, Henrik; Helm, Paul A; Stern, Gary A; Strachan, William M J; Burniston, Deborah A; Bidleman, Terry F

    2015-12-01

    The Arctic has been contaminated by legacy organochlorine pesticides (OCPs) and currently used pesticides (CUPs) through atmospheric transport and oceanic currents. Here we report the time trends and air-water exchange of OCPs and CUPs from research expeditions conducted between 1993 and 2013. Compounds determined in both air and water were trans- and cis-chlordanes (TC, CC), trans- and cis-nonachlors (TN, CN), heptachlor exo-epoxide (HEPX), dieldrin (DIEL), chlorobornanes (ΣCHBs and toxaphene), dacthal (DAC), endosulfans and metabolite endosulfan sulfate (ENDO-I, ENDO-II, and ENDO SUL), chlorothalonil (CHT), chlorpyrifos (CPF), and trifluralin (TFN). Pentachloronitrobenzene (PCNB and quintozene) and its soil metabolite pentachlorothianisole (PCTA) were also found in air. Concentrations of most OCPs declined in surface water, whereas some CUPs increased (ENDO-I, CHT, and TFN) or showed no significant change (CPF and DAC), and most compounds declined in air. Chlordane compound fractions TC/(TC + CC) and TC/(TC + CC + TN) decreased in water and air, while CC/(TC + CC + TN) increased. TN/(TC + CC + TN) also increased in air and slightly, but not significantly, in water. These changes suggest selective removal of more labile TC and/or a shift in chlordane sources. Water-air fugacity ratios indicated net volatilization (FR > 1.0) or near equilibrium (FR not significantly different from 1.0) for most OCPs but net deposition (FR < 1.0) for ΣCHBs. Net deposition was shown for ENDO-I on all expeditions, while the net exchange direction of other CUPs varied. Understanding the processes and current state of air-surface exchange helps to interpret environmental exposure and evaluate the effectiveness of international protocols and provides insights for the environmental fate of new and emerging chemicals. PMID:26196214

  10. Application of a laser Doppler vibrometer for air-water to subsurface signature detection

    Science.gov (United States)

    Land, Phillip; Roeder, James; Robinson, Dennis; Majumdar, Arun

    2015-05-01

    There is much interest in detecting a target and optical communications from an airborne platform to a platform submerged under water. Accurate detection and communications between underwater and aerial platforms would increase the capabilities of surface, subsurface, and air, manned and unmanned vehicles engaged in oversea and undersea activities. The technique introduced in this paper involves a Laser Doppler Vibrometer (LDV) for acousto-optic sensing for detecting acoustic information propagated towards the water surface from a submerged platform inside a 12 gallon water tank. The LDV probes and penetrates the water surface from an aerial platform to detect air-water surface interface vibrations caused by an amplifier to a speaker generating a signal generated from underneath the water surface (varied water depth from 1" to 8"), ranging between 50Hz to 5kHz. As a comparison tool, a hydrophone was used simultaneously inside the water tank for recording the acoustic signature of the signal generated between 50Hz to 5kHz. For a signal generated by a submerged platform, the LDV can detect the signal. The LDV detects the signal via surface perturbations caused by the impinging acoustic pressure field; proving a technique of transmitting/sending information/messages from a submerged platform acoustically to the surface of the water and optically receiving the information/message using the LDV, via the Doppler Effect, allowing the LDV to become a high sensitivity optical-acoustic device. The technique developed has much potential usage in commercial oceanography applications. The present work is focused on the reception of acoustic information from an object located underwater.

  11. Gas transfer at the air-water interface in a turbulent flow environment

    Energy Technology Data Exchange (ETDEWEB)

    Herlina

    2005-07-01

    The gas transfer process across the air-water interface in a bottom-shear-induced turbulent environment was investigated to gain improved fundamental understanding of the physical mechanisms that control the process. For this purpose, it is necessary to reveal the hydrodynamics of the flow field as well as the molecular diffusion and the turbulent transport contributions to the total flux. Therefore, detailed laboratory experiments were conducted to obtain this information. The experiments were performed in a grid-stirred tank using a combined Particle Image Velocimetry - Laser Induced Fluorescence (PIV-LIF) technique that has been developed for these near surface gas transfer measurements. The turbulence characteristics of the velocity near the interface were acquired from the PIV measurements and showed generally good agreement with the theoretical profiles from Hunt and Graham (1978). The LIF technique enabled visualization of the planar concentration fields which provided more insight into the gas transfer mechanisms. The high data resolution allowed detailed quantification of the concentration distribution within the thin aqueous boundary layer. The interrelated interpretation of the obtained results suggest that the gas transfer process is controlled by a spectrum of different eddy sizes and the gas transfer at different turbulence levels can be associated to certain eddy sizes. For high turbulence levels the gas transfer should be asymptotic to the small eddy model, whereas for low turbulence level to the large eddy model. The new results of turbulent mass flux should aid as an excellent database in refining numerical models and developing more accurate models for the prediction of the transfer velocity. (orig.)

  12. Pulmonary surfactant proteins SP-B and SP-C in spread monolayers at the air-water interface: II. Monolayers of pulmonary surfactant protein SP-C and phospholipids.

    OpenAIRE

    Taneva, S; Keough, K M

    1994-01-01

    The interaction of the hydrophobic pulmonary surfactant protein SP-C with dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG) and DPPC:DPPG (7:3, mol:mol) in spread monolayers at the air-water interface has been studied. At low concentrations of SP-C (about 0.5 mol% or 3 weight%protein) the protein-lipid films collapsed at surface pressures of about 70 mN.m-1, comparable to those of the lipids alone. At initial protein concentrations higher than 0.8 mol%, or 4 weight...

  13. Co-current air-water flow in downward sloping pipes: Transport of capacity reducing gas pockets in wastewater mains

    OpenAIRE

    Pothof, I.W.M.

    2011-01-01

    Air-water flow is an undesired condition in many systems for the transportation of water or wastewater. Air in storm water tunnels may get trapped and negatively affect the system. Air pockets in hydropower tunnels or sewers may cause blow-back events and inadmissible pressure spikes. Water pipes and wastewater pressure mains in particular are subject to air pocket formation in downward-sloping reaches, such as inverted siphons or terrain slopes. Air pocket accumulation causes energy losses a...

  14. Similarity of coupled heat and mass transfer between air-water and air-liquid desiccant direct-contact systems

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiao-Hua; Jiang, Yi [Department of Building Science, School of Architecture, Tsinghua University, Beijing 100084 (China); Li, Zhen [Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China)

    2009-12-15

    Packed-bed heat and mass transfer devices are widely used in air-conditioning systems, such as cooling tower, evaporative cooler of air-water direct-contact devices, dehumidifier and regenerator of air-liquid desiccant direct-contact devices. Similarities of heat and mass transfer characteristics between air-water and air-liquid desiccant devices are considered and investigated in this paper. Same reachable handling region of outlet air can be obtained for both air-water and air-liquid desiccant devices, which is among three boundary lines, isenthalpic line of inlet air, iso-relative humidity line of inlet fluid (water or desiccant), and the connecting line of inlet statuses of air and fluid. Inlet conditions of air and fluid affect heat and mass transfer characteristics to some extent, so that a zonal method is proposed only according to the relative statuses of inlet air to inlet fluid. Four zones, dehumidification zones A, D and regeneration zones B, C, are divided for air-desiccant direct-contact devices. The first three zones A, B and C are divided for air-water direct-contact devices, with the same zonal properties as those of air-desiccant devices. In order to obtain better humidification performance, fluid should be heated (in zone C) rather than air (in zone B). And fluid should be cooled (in zone A) rather than air (in zone D) to obtain better dehumidification performance. Counter-flow pattern should be applied for best mass transfer performance in the same conditions within the recommended zone A or C, while parallel-flow pattern is the best in zone B or D. (author)

  15. Scanning force microscopy at the air-water interface of an air bubble coated with pulmonary surfactant.

    OpenAIRE

    Knebel, D; Sieber, M; Reichelt, R.; Galla, H-J; Amrein, M

    2002-01-01

    To study the structure-function relationship of pulmonary surfactant under conditions close to nature, molecular films of a model system consisting of dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylglycerol, and surfactant-associated protein C were prepared at the air-water interface of air bubbles about the size of human alveoli (diameter of 100 microm). The high mechanical stability as well as the absence of substantial film flow, inherent to small air bubbles, allowed for scanning ...

  16. Micrometeorological Measurement of Fetch- and Atmospheric Stability-Dependent Air- Water Exchange of Legacy Semivolatile Organic Contaminants in Lake Superior

    Science.gov (United States)

    Perlinger, J. A.; Tobias, D. E.; Rowe, M. D.

    2008-12-01

    Coastal waters including the Laurentian Great Lakes are particularly susceptible to local, regional, and long- range transport and deposition of semivolatile organic contaminants (SOCs) as gases and/or associated with particles. Recently-marketed SOCs can be expected to undergo net deposition in surface waters, whereas legacy SOCs such as polychlorinated biphenyls (PCBs) are likely to be at equilibrium with respect to air-water exchange, or, if atmospheric concentrations decrease through, e.g., policy implementation, to undergo net gas emission. SOC air-water exchange flux is usually estimated using the two-film model. This model describes molecular diffusion through the air and water films adjacent to the air-water interface. Air-water exchange flux is estimated as the product of SOC fugacity, typically based on on-shore gaseous concentration measurements, and a transfer coefficient, the latter which is estimated from SOC properties and environmental conditions. The transfer coefficient formulation commonly applied neglects resistance to exchange in the internal boundary layer under atmospherically stable conditions, and the use of on-shore gaseous concentration neglects fetch-dependent equilibration, both of which will tend to cause overestimation of flux magnitude. Thus, for legacy chemicals or in any highly contaminated surface water, the rate at which the water is cleansed through gas emission tends to be over-predicted using this approach. Micrometeorological measurement of air-water exchange rates of legacy SOCs was carried out on ships during four transect experiments during off-shore flow in Lake Superior using novel multicapillary collection devices and thermal extraction technology to measure parts-per-quadrillion SOC levels. Employing sensible heat in the modified Bowen ratio, fluxes at three over-water stations along the transects were measured, along with up-wind, onshore gaseous concentration and aqueous concentration. The atmosphere was unstable for

  17. Spread mixed monolayers of deoxycholic and dehydrocholic acids at the air-water interface, effect of subphase pH. Characterization by axisymmetric drop shape analysis.

    Science.gov (United States)

    Messina, Paula V; Fernández-Leyes, Marcos D; Prieto, Gerardo; Ruso, Juan M; Sarmiento, Félix; Schulz, Pablo C

    2008-01-01

    Bile acids (deoxycholic and dehydrocholic acids) spread mixed monolayers behavior at the air/water interface were studied as a function of subphase pH using a constant surface pressure penetration Langmuir balance based on the Axisymmetric Drop Shape Analysis (ADSA). We examined the influence of electrostatic, hydrophobic and hydration forces on the interaction between amphiphilic molecules at the interface by the collapse area values, the thermodynamic parameters and equation of state virial coefficients analysis. The obtained results showed that at neutral (pH=6.7) or basic (pH=10) subphase conditions the collapse areas values are similar to that of cholanoic acid and consistent with the cross-sectional area of the steroid nucleus (approximately 40 A(2)). The Gibbs energy of mixing values (DeltaG(mix) or =1). Such behavior indicates that the polar groups of the molecules interacts each other more strongly by repulsive electrostatic forces than with the more hydrophobic part of the molecule.

  18. Air/water heat pumps in older buildings. Energy conservation in a stock; Luft/Wasser-Waermepumpen im Altbau. Energiesparen im Bestand

    Energy Technology Data Exchange (ETDEWEB)

    Bauknecht, Steffen [Mitsubishi Electric, Ratingen (Germany)

    2010-02-15

    Due to the technical development, nowadays it is possible to heat older buildings which are not insulated thermally subsequently with monovalent air/water heat pumps. For example, in Bonn-Oberkassel (Federal Republic of Germany) a nearly one hundred year old art nouveau mansion is supplied with apartment warmth and warm water by means of two air/water heat pumps. The economical heat supply as well as the small structural expenditure decided to use this technology.

  19. Ecosystem Metabolism and Air-Water Fluxes of Greenhouse Gases in High Arctic Wetland Ponds

    Science.gov (United States)

    Lehnherr, I.; Venkiteswaran, J.; St. Louis, V. L.; Emmerton, C.; Schiff, S. L.

    2012-12-01

    Freshwater lakes and wetlands can be very productive systems on the Arctic landscape compared to terrestrial tundra ecosystems and provide valuable resources to many organisms, including waterfowl, fish and humans. Rates of ecosystem productivity dictate how much energy flows through food webs, impacting the abundance of higher-level organisms (e.g., fish), as well as the net carbon balance, which determines whether a particular ecosystem is a source or sink of carbon. Climate change is predicted to result in warmer temperatures, increased precipitation and permafrost melting in the Arctic and is already altering northern ecosystems at unprecedented rates; however, it is not known how freshwater systems are responding to these changes. To predict how freshwater systems will respond to complex environmental changes, it is necessary to understand the key processes, such as primary production and ecosystem respiration, that are driving these systems. We sampled wetland ponds (n=8) and lakes (n=2) on northern Ellesmere Island (81° N, Nunavut, Canada) during the open water season for a suite of biogeochemical parameters, including concentrations of dissolved gases (O2, CO2, CH4, N2O) as well as stable-isotope ratios of dissolved inorganic carbon (δ13C-DIC), dissolved oxygen (δ18O-DO), and water (δ18O-H2O). We will present rates of primary production and ecosystem respiration, modeled from the concentration and stable isotope ratios of DIC and DO, as well as air-water gas exchange of greenhouse gases in these high Arctic ponds and lakes. Preliminary results demonstrate that ecosystem metabolism in these ponds was high enough to result in significant deviations in the isotope ratios of DIC and DO from atmospheric equilibrium conditions. In other words ecosystem rates of primary production and respiration were faster than gas exchange even in these small, shallow, well-mixed ponds. Furthermore, primary production was elevated enough at all sites except Lake Hazen, a

  20. Towards Organized Hybrid Nanomaterials at the Air/Water Interface Based on Liquid-Crystal/ZnO Nanocrystals.

    Science.gov (United States)

    Paczesny, Jan; Wolska-Pietkiewicz, Małgorzata; Binkiewicz, Ilona; Wróbel, Zbigniew; Wadowska, Monika; Matuła, Kinga; Dzięcielewski, Igor; Pociecha, Damian; Smalc-Koziorowska, Julita; Lewiński, Janusz; Hołyst, Robert

    2015-11-16

    The ability to self-assemble nanosized ligand-stabilized metal oxide or semiconductor materials offers an intriguing route to engineer nanomaterials with new tailored properties from the disparate components. We describe a novel one-pot two-step organometallic approach to prepare ZnO nanocrystals (NCs) coated with deprotonated 4-(dodecyloxy)benzoic acid (i.e., an X-type liquid-crystalline ligand) as a model LC system (termed ZnO-LC1 NCs). Langmuir and Langmuir-Blodgett films of the resulting hybrids are investigated. The observed behavior of the ZnO NCs at the air/water interface is rationalized by invoking a ZnO-interdigitation process mediated by the anchored liquid-crystalline shell. The ordered superstructures form according to mechanism based on a ZnO-interdigitation process mediated by liquid crystals (termed ZIP-LC). The external and directed force applied upon compression at the air/water interface and the packing of the ligands that stabilize the ZnO cores drives the formation of nanorods of ordered internal structure. To study the process in detail, we follow a nontraditional protocol of thin-film investigation. We collect the films from the air/water interface in powder form (ZnO-LC1 LB), resuspend the powder in organic solvents and utilize otherwise unavailable experimental techniques. The structural and physical properties of the resulting superlattices were studied by using electron microscopy, atomic force microscopy, X-ray studies, dynamic light scattering, thermogravimetric analysis, UV/Vis absorption, and photoluminescence spectroscopy. PMID:26427916

  1. Characteristics of centrifugal pumps handling air-water mixtures and size of air bubbles in pump impellers

    International Nuclear Information System (INIS)

    Characteristics of centrifugal pumps handling air-water mixtures are analyzed on the basis of a gas-liquid separated flow model, which is generally accepted in the analysis of the data on a two-phase flow in piping systems. And a method for predicting the pump characteristics is presented with use of parameters of friction-loss and shock-loss multipliers. Size of air bubbles flowing through pump impellers was measured. The bubbles in the inlet region of the impellers have an extremely uniform size with fairly small diameters. But in course of flow, the bubble diameter grows gradually due to coalescence of the bubbles. (author)

  2. Polycyclic aromatic hydrocarbon (PAH) and oxygenated PAH (OPAH) air-water exchange during the deepwater horizon oil spill.

    Science.gov (United States)

    Tidwell, Lane G; Allan, Sarah E; O'Connell, Steven G; Hobbie, Kevin A; Smith, Brian W; Anderson, Kim A

    2015-01-01

    Passive sampling devices were used to measure air vapor and water dissolved phase concentrations of 33 polycyclic aromatic hydrocarbons (PAHs) and 22 oxygenated PAHs (OPAHs) at four Gulf of Mexico coastal sites prior to, during, and after shoreline oiling from the Deepwater Horizon oil spill (DWH). Measurements were taken at each site over a 13 month period, and flux across the water-air boundary was determined. This is the first report of vapor phase and flux of both PAHs and OPAHs during the DWH. Vapor phase sum PAH and OPAH concentrations ranged between 1 and 24 ng/m(3) and 0.3 and 27 ng/m(3), respectively. PAH and OPAH concentrations in air exhibited different spatial and temporal trends than in water, and air-water flux of 13 individual PAHs were strongly associated with the DWH incident. The largest PAH volatilizations occurred at the sites in Alabama and Mississippi in the summer, each nominally 10,000 ng/m(2)/day. Acenaphthene was the PAH with the highest observed volatilization rate of 6800 ng/m(2)/day in September 2010. This work represents additional evidence of the DWH incident contributing to air contamination, and provides one of the first quantitative air-water chemical flux determinations with passive sampling technology. PMID:25412353

  3. Multi-scale modeling of mycosubtilin lipopeptides at the air/water interface: structure and optical second harmonic generation.

    Science.gov (United States)

    Loison, Claire; Nasir, Mehmet Nail; Benichou, Emmanuel; Besson, Françoise; Brevet, Pierre-François

    2014-02-01

    Monolayers of the lipopeptide mycosubtilin are studied at the air/water interface. Their structure is investigated using molecular dynamics simulations. All-atom models suggest that the lipopeptide is flexible and aggregates at the interface. To achieve simulation times of several microseconds, a coarse-grained (CG) model based on the MARTINI force field was also used. These CG simulations describe the formation of half-micelles at the interface for surface densities up to 1 lipopeptide per nm(2). In these aggregates, the tyrosine side chain orientation is found to be constrained: on average, its main axis, as defined along the C-OH bond, aligns along the interface normal and points towards the air side. The origin of the optical second harmonic generation (SHG) from mycosubtilin monolayers at the air/water interface is also investigated. The molecular hyperpolarizability of the lipopeptide is obtained from quantum chemistry calculations. The tyrosine side chain contribution to the hyperpolarizability is found to be dominant. The orientation distribution of tyrosine, associated with a dominant hyperpolarizability component along the C-OH bond of the tyrosine, yields a ratio of the susceptibility elements χ((2))(ZZZ)/χ((2))(ZXX) consistent with the experimental measurements recently reported by M. N. Nasir et al. [Phys. Chem. Chem. Phys., 2013, 15, 19919]. PMID:24346061

  4. PREPARATION OF PERFLUOROOCTANOYL-MODIFIEDPOLY(VINYL-ALCOHOL)S AND THEIR ADSORPTION AT AN AIR-WATER INTERFACE

    Institute of Scientific and Technical Information of China (English)

    Pu-xin Zhu; Xiang-dong Luo; Rui-xia Li; Dac-heng Wu

    2002-01-01

    Perfluorooctanoyl modified poly(vinyl alcohol)s (FPVA) were prepared by means of substituting a small amount of hydroxyl groups on the backbone of poly(vinyl alcohol), for which the initial degree of polymerization is equal to 1750. The substitution extent, defined by the number of substituting units in a chain, for the four FPVA samples was in the range of 0.5-5 perfluorooctanoyl groups per chain. The FPVA samples with the highest substitution extent still had good solubility in water. It was shown by experimental measurement at 30.0±0.1 C that the surface tension of the aqueous solution of the highest substituted FPVA decreased to 16.6 mN/m at a higher concentration, e.g. about 0.1 g/mL. Obviously,macromolecules of FPVA exhibit a very strong tendency to adsorb at the air-water interface, because the hydrophobic perfluorooctanoyl groups in FPVA have a very high surface activity as they are in small molecular fluorinated surfactants.The chain conformation of such a model polymer adsorbed on the air-water interface was also discussed.

  5. Palmitate Luciferin: A molecular design for the second harmonic generation study of ion complexation at the air-water interface

    International Nuclear Information System (INIS)

    A molecular organic chromophore, Palmitate-Luciferin, has been synthesized for studying ion complexation at the air-water interface using second harmonic generation (SHG). This molecule was designed through the addition of a long hydrophobic palmitoyl alkyl chain to the aromatic π-electron system of Luciferin. We first demonstrate that this organic chromophore is a potential candidate for SHG studies of ion complexation with the measurement of its first hyper-polarizability in aqueous solutions by hyper Rayleigh scattering (HRS) with and without calcium ions. Then, we characterize the Palmitate-Luciferin surfactant properties at the air-water interface combining surface tension measurements with a surface SHG study and Brewster angle imaging. These results allow us to build a molecular description of the chromophore at the interface and observe its molecular reorganization during the monolayer compression leading to the formation of aggregates. Finally, we show that the initial goal of the designing work is achieved since Palmitate-Luciferin indeed exhibits a higher SHG response in the presence of calcium ions in the aqueous sub-phase as expected. (authors)

  6. Photochemical formation of silver and gold nanostructures at the air-water interface and their electrocatalytic properties

    International Nuclear Information System (INIS)

    In this paper, we report a simple method of fabricating silver and gold nanostructures at the air-water interface, which can be spontaneously assembled through the reduction of AgNO3 and HAuCl4 with ultraviolet (UV) irradiation in the presence of polyacrylic acid (PAA), respectively. It was found that the building blocks in the silver nanostructure are mainly interwoven silver nanofilaments, while those of the gold nanostructure are mainly different sizes of gold nanoparticles and some truncated gold nanoplates, and even coalescence into networks. At the air-water interface, these silver and gold nanostructures can be easily transferred onto the surface of indium tin oxide (ITO) slides and used for electrochemical measurements. After a replacement reaction with H2PdCl4, the silver nanostructure is transformed into a Ag-Pd bimetallic nanostructure, with good electrocatalytic activity for O2 reduction. The gold nanostructure can also show high electrocatalytic activity to the oxidation of nitric oxide (NO) with a detection limit of about 10 μM NaNO2 at S/N = 3

  7. Image processing analysis on the air-water slug two-phase flow in a horizontal pipe

    Science.gov (United States)

    Dinaryanto, Okto; Widyatama, Arif; Majid, Akmal Irfan; Deendarlianto, Indarto

    2016-06-01

    Slug flow is a part of intermittent flow which is avoided in industrial application because of its irregularity and high pressure fluctuation. Those characteristics cause some problems such as internal corrosion and the damage of the pipeline construction. In order to understand the slug characteristics, some of the measurement techniques can be applied such as wire-mesh sensors, CECM, and high speed camera. The present study was aimed to determine slug characteristics by using image processing techniques. Experiment has been carried out in 26 mm i.d. acrylic horizontal pipe with 9 m long. Air-water flow was recorded 5 m from the air-water mixer using high speed video camera. Each of image sequence was processed using MATLAB. There are some steps including image complement, background subtraction, and image filtering that used in this algorithm to produce binary images. Special treatments also were applied to reduce the disturbance effect of dispersed bubble around the bubble. Furthermore, binary images were used to describe bubble contour and calculate slug parameter such as gas slug length, gas slug velocity, and slug frequency. As a result the effect of superficial gas velocity and superficial liquid velocity on the fundamental parameters can be understood. After comparing the results to the previous experimental results, the image processing techniques is a useful and potential technique to explain the slug characteristics.

  8. Dissecting the Molecular Structure of the Air/Water Interface from Quantum Simulations of the Sum-Frequency Generation Spectrum.

    Science.gov (United States)

    Medders, Gregory R; Paesani, Francesco

    2016-03-23

    The molecular characterization of the air/water interface is a key step in understanding fundamental multiphase phenomena ranging from heterogeneous chemical processes in the atmosphere to the hydration of biomolecules. The apparent simplicity of the air/water interface, however, masks an underlying complexity associated with the dynamic nature of the water hydrogen-bond network that has so far hindered an unambiguous characterization of its microscopic properties. Here, we demonstrate that the application of quantum many-body molecular dynamics, which enables spectroscopically accurate simulations of water from the gas to the condensed phase, leads to a definitive molecular-level picture of the interface region. For the first time, excellent agreement is obtained between the simulated vibrational sum-frequency generation spectrum and the most recent state-of-the-art measurements, without requiring any empirical frequency shift or ad hoc scaling of the spectral intensity. A systematic dissection of the spectral features demonstrates that a rigorous representation of nuclear quantum effects as well as of many-body energy and electrostatic contributions is necessary for a quantitative reproduction of the experimental data. The unprecedented accuracy of the simulations presented here indicates that quantum many-body molecular dynamics can enable predictive studies of aqueous interfaces, which by complementing analogous experimental measurements will provide unique molecular insights into multiphase and heterogeneous processes of relevance in chemistry, biology, materials science, and environmental research. PMID:26943730

  9. The Equilibria of Diosgenin-Phosphatidylcholine and Diosgenin-Cholesterol in Monolayers at the Air/Water Interface.

    Science.gov (United States)

    Janicka, Katarzyna; Jastrzebska, Izabella; Petelska, Aneta Dorota

    2016-08-01

    Diosgenin (Dio) has shown many treatment properties, but the most important property is cytotoxic activity in cancer cells. In this study, we investigated monolayers of Dio, cholesterol (Ch), and phosphatidylcholine (PC) at the air/water interface. The measurements were carried with a Langmuir Teflon trough and a Nima 9000 tensiometer program. The surface tension values of pure and mixed monolayers were used to calculate π-A isotherms and determine molecular surface areas. We were able to demonstrate the formation of complexes between Dio and PC and Dio and Ch molecules also. We considered the equilibrium between individual components and the formed complexes. In addition, we established that diosgenin and the lipids formed highly stable 1:1 complexes. PMID:27350149

  10. X-ray CT-Derived Soil Characteristics Explain Varying Air, Water, and Solute Transport Properties across a Loamy Field

    DEFF Research Database (Denmark)

    Paradelo Pérez, Marcos; Katuwal, Sheela; Møldrup, Per;

    2016-01-01

    when the limiting macroporosity (the minimum macroporosity for every 0.6-mm layer along the soil column) was used, suggesting that soil layers with the narrowest macropore section restricted the flow through the whole soil column. Water, air, and solute transport were related with the CT......The characterization of soil pore space geometry is important for explaining fluxes of air, water, and solutes through soil and understanding soil hydrogeochemical functions. X-ray computed tomography (CT) can be applied for this characterization, and in this study CT-derived parameters were used...... to explain water, air, and solute transport through soil. Forty-five soil columns (20 by 20 cm) were collected from an agricultural field in Estrup, Denmark, and subsequently scanned using a medical CT scanner. Nonreactive tracer leaching experiments were performed in the laboratory along with measurements...

  11. Synthesis of a Two-Dimensional Covalent Organic Monolayer through Dynamic Imine Chemistry at the Air/Water Interface.

    Science.gov (United States)

    Dai, Wenyang; Shao, Feng; Szczerbiński, Jacek; McCaffrey, Ryan; Zenobi, Renato; Jin, Yinghua; Schlüter, A Dieter; Zhang, Wei

    2016-01-01

    A two-dimensional covalent organic monolayer was synthesized from simple aromatic triamine and dialdehyde building blocks by dynamic imine chemistry at the air/water interface (Langmuir-Blodgett method). The obtained monolayer was characterized by optical microscopy, scanning electron microscopy, and atomic force microscopy, which unambiguously confirmed the formation of a large (millimeter range), unimolecularly thin aromatic polyimine sheet. The imine-linked chemical structure of the obtained monolayer was characterized by tip-enhanced Raman spectroscopy, and the peak assignment was supported by spectra simulated by density functional theory. Given the modular nature and broad substrate scope of imine formation, the work reported herein opens up many new possibilities for the synthesis of customizable 2D polymers and systematic studies of their structure-property relationships.

  12. Influence of current velocity and wind speed on air-water gas exchange in a mangrove estuary

    Science.gov (United States)

    Ho, David T.; Coffineau, Nathalie; Hickman, Benjamin; Chow, Nicholas; Koffman, Tobias; Schlosser, Peter

    2016-04-01

    Knowledge of air-water gas transfer velocities and water residence times is necessary to study the fate of mangrove derived carbon exported into surrounding estuaries and ultimately to determine carbon balances in mangrove ecosystems. For the first time, the 3He/SF6 dual tracer technique, which has been proven to be a powerful tool to determine gas transfer velocities in the ocean, is applied to Shark River, an estuary situated in the largest contiguous mangrove forest in North America. The mean gas transfer velocity was 3.3 ± 0.2 cm h-1 during the experiment, with a water residence time of 16.5 ± 2.0 days. We propose a gas exchange parameterization that takes into account the major sources of turbulence in the estuary (i.e., bottom generated shear and wind stress).

  13. A Designed A. vinelandii-S. elongatus Coculture for Chemical Photoproduction from Air, Water, Phosphate, and Trace Metals.

    Science.gov (United States)

    Smith, Matthew J; Francis, Matthew B

    2016-09-16

    Microbial mutualisms play critical roles in a diverse number of ecosystems and have the potential to improve the efficiency of bioproduction for desirable chemicals. We investigate the growth of a photosynthetic cyanobacterium, Synechococcus elongatus PCC 7942, and a diazotroph, Azotobacter vinelandii, in coculture. From initial studies of the coculture grown in media with glutamate, we proposed a model of cross-feeding between these organisms. We then engineer a new microbial mutualism between Azotobacter vinelandii AV3 and cscB Synechococcus elongatus that grows in the absence of fixed carbon or nitrogen. The coculture cannot grow in the absence of a sucrose-exporting S. elongatus, and neither organism can grow alone without fixed carbon or nitrogen. This new system has the potential to produce industrially relevant products, such as polyhydroxybutyrate (PHB) and alginate, from air, water, phosphate, trace metals, and sunlight. We demonstrate the ability of the coculture to produce PHB in this work. PMID:27232890

  14. Monolayer behaviour of chiral compounds at the air-water interface: 4-hexadecyloxy-butane-1,2-diol

    DEFF Research Database (Denmark)

    Rietz, R.; Rettig, W.; Brezesinski, G.;

    1996-01-01

    Monolayers of the pure S-enantiomer (x(S) = 1) and of two mixtures x(S) = 0.75 and x(S) = 0.5 (racemate) of 4-hexadecyloxy-butane-1,2-diol (C16H33-O-CH2-CH2-CHOH-CH2OH) (HOBD) have been studied at the air-water interface by thermodynamic measurements, fluorescence microscopy and X-ray diffraction...... clockwise and counterclockwise. The number of the left- and right-handed arms depends on the mixing ratio. At lower lateral pressures S-HOBD and the mixture with x(S) = 0.75 exhibit a chiral structure. At pressures above 25 mN m(-1) a centered rectangular structure with a tilt of the molecules towards...

  15. Interfacial area transport of vertical upward air-water two-phase flow in an annulus channel

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, J.J. [Korea Atomic Energy Research Institute, 150 Deokjin, Yuseong, Daejeon 305-353 (Korea, Republic of)], E-mail: jjjeong@kaeri.re.kr; Ozar, B.; Dixit, A. [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, IN 47907 (United States); Julia, J.E. [Dept. de Ingenieria Mecanica y Construccion, Universitat Jaume I. Castellon (Spain); Hibiki, T.; Ishii, M. [School of Nuclear Engineering, Purdue University, 400 Central Drive, West Lafayette, IN 47907 (United States)

    2008-02-15

    An experimental study on the interfacial area transport (IAT) of vertical, upward, air-water two-phase flows in an annulus channel has been conducted. The inner and outer diameters of the annular channel were 19.1 mm and 38.1 mm, respectively. Nineteen inlet flow conditions were selected, which cover bubbly, cap-slug, and churn-turbulent flows. The local flow parameters, such as void fraction, interfacial area concentration (IAC), and bubble interface velocity, were measured at nine radial positions for the three axial locations (z/D{sub H} = 52, 149 and 230). The radial and axial evolutions of local flow structure were interpreted in terms of bubble coalescence and breakup. The measured data can be used for the development of the bubble coalescence/breakup models for the IAT model and some closure models for computational fluid dynamics.

  16. Gas exchange rates across the sediment-water andd air-water interfaces in south San Francisco Bay

    International Nuclear Information System (INIS)

    Radon 222 concentrations in the water and sedimentary columns and radon exchange rates across the sediment-water and air-water interfaces have been measured in a section of south San Francisco Bay. Two independent methods have been used to determine sediment-water exchange rates, and the annual averages of these methods agree within the uncertainity of the determinations, about 20%. The annual average of bethic fluxes from shoal areas is nearly a factor of 2 greater than fluxes from the channel areas. Fluxes from the shoal and channel areas exceed those expected from simple molecular diffusion by factors of 4 and 2, respectively, apparently due to macrofaunal irrigation. Values of the gas transfer coefficient for radon exchange across the air-water inteface were determined by constructing a radon mass balance for the water column and by direct measurement using floating chambers. The chamber method appears to yield results which are too high. Transfer coefficients computed using the mass balance method range from 0.4 m/day to 1.8 m/day, with a 6-year average of 1.0 m/day. Gas exchange is linearly dependent upon wind speed over a wind speed range of 3.2--6.4 m/s, but shows no dependence upon current velocity. Gas transfer coefficients predicted from an empirical relationship between gas exchange rates and wind speed observed in lakes and the oceans are within 30% of the coefficients determined from the radon mass balance and are considerably more accurate than coefficients predicted from theoretical gas exchange models

  17. Behavior of lysozyme adsorbed onto biological liquid crystal lipid monolayer at the air/water interface

    Science.gov (United States)

    Lu, Xiaolong; Shi, Ruixin; Hao, Changchun; Chen, Huan; Zhang, Lei; Li, Junhua; Xu, Guoqing; Sun, Runguang

    2016-09-01

    The interaction between proteins and lipids is one of the basic problems of modern biochemistry and biophysics. The purpose of this study is to compare the penetration degree of lysozyme into 1,2-diapalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoethano-lamine (DPPE) by analyzing the data of surface pressure-area (π-A) isotherms and surface pressure-time (π-T) curves. Lysozyme can penetrate into both DPPC and DPPE monolayers because of the increase of surface pressure at an initial pressure of 15 mN/m. However, the changes of DPPE are larger than DPPC, indicating stronger interaction of lysozyme with DPPE than DPPC. The reason may be due to the different head groups and phase state of DPPC and DPPE monolayers at the surface pressure of 15 mN/m. Atomic force microscopy reveals that lysozyme was absorbed by DPPC and DPPE monolayers, which leads to self-aggregation and self-assembly, forming irregular multimers and conical multimeric. Through analysis, we think that the process of polymer formation is similar to the aggregation mechanism of amyloid fibers. Project supported by the National Natural Science Foundation of China (Grant Nos. 21402114 and 11544009), the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2016JM2010), the Fundamental Research Funds for the Central Universities of China (Grant No. GK201603026), and the National University Science and Technology Innovation Project of China (Grant No. 201610718013).

  18. INTERACT

    DEFF Research Database (Denmark)

    Jochum, Elizabeth; Borggreen, Gunhild; Murphey, TD

    This paper considers the impact of visual art and performance on robotics and human-computer interaction and outlines a research project that combines puppetry and live performance with robotics. Kinesics—communication through movement—is the foundation of many theatre and performance traditions...... interaction between a human operator and an artificial actor or agent. We can apply insights from puppetry to develop culturally-aware robots. Here we describe the development of a robotic marionette theatre wherein robotic controllers assume the role of human puppeteers. The system has been built, tested......, and demonstrated in public settings. We then describe INTERACT, a proposed research project that stages the robotic marionettes in a live performance. The interdisciplinary project brings humanities research to bear on scientific and technological inquiry, and culminates in the development a live performance which...

  19. Interactions

    DEFF Research Database (Denmark)

    The main theme of this anthology is the unique interaction between mathematics, physics and philosophy during the beginning of the 20th century. Seminal theories of modern physics and new fundamental mathematical structures were discovered or formed in this period. Significant physicists such as ......The main theme of this anthology is the unique interaction between mathematics, physics and philosophy during the beginning of the 20th century. Seminal theories of modern physics and new fundamental mathematical structures were discovered or formed in this period. Significant physicists...... also key figures in the philosophical discussions of nature and science - from philosophical tendencies like logical empiricism via critical rationalism to various neo-Kantian trends....

  20. Water temperature effect on upward air-water flow in a vertical pipe: Local measurements database using four-sensor conductivity probes and LDA

    Science.gov (United States)

    Monrós-Andreu, G.; Chiva, S.; Martínez-Cuenca, R.; Torró, S.; Juliá, J. E.; Hernández, L.; Mondragón, R.

    2013-04-01

    Experimental work was carried out to study the effects of temperature variation in bubbly, bubbly to slug transition. Experiments were carried out in an upward air-water flow configuration. Four sensor conductivity probes and LDA techniques was used together for the measurement of bubble parameters. The aim of this paper is to provide a bubble parameter experimental database using four-sensor conductivity probes and LDA technique for upward air-water flow at different temperatures and also show transition effect in different temperatures under the boiling point.

  1. Water temperature effect on upward air-water flow in a vertical pipe: Local measurements database using four-sensor conductivity probes and LDA

    Directory of Open Access Journals (Sweden)

    Hernández L.

    2013-04-01

    Full Text Available Experimental work was carried out to study the effects of temperature variation in bubbly, bubbly to slug transition. Experiments were carried out in an upward air-water flow configuration. Four sensor conductivity probes and LDA techniques was used together for the measurement of bubble parameters. The aim of this paper is to provide a bubble parameter experimental database using four-sensor conductivity probes and LDA technique for upward air-water flow at different temperatures and also show transition effect in different temperatures under the boiling point.

  2. Measurement of the Surface Dilatational Viscosity of an Insoluble Surfactant Monolayer at the Air/Water Interface Using a Pendant Drop Apparatus

    Science.gov (United States)

    Lorenzo, Jose; Couzis, Alex; Maldarelli, Charles; Singh, Bhim S. (Technical Monitor)

    2000-01-01

    When a fluid interface with surfactants is at rest, the interfacial stress is isotropic (as given by the equilibrium interfacial tension), and is described by the equation of state which relates the surface tension to the surfactant surface concentration. When surfactants are subjected to shear and dilatational flows, flow induced interaction of the surfactants; can create interfacial stresses apart from the equilibrium surface tension. The simplest relationship between surface strain rate and surface stress is the Boussinesq-Scriven constitutive equation completely characterized by three coefficients: equilibrium interfacial tension, surface shear viscosity, and surface dilatational viscosity Equilibrium interfacial tension and surface shear viscosity measurements are very well established. On the other hand, surface dilatational viscosity measurements are difficult because a flow which change the surface area also changes the surfactant surface concentration creating changes in the equilibrium interfacial tension that must be also taken into account. Surface dilatational viscosity measurements of existing techniques differ by five orders of magnitude and use spatially damped surface waves and rapidly expanding bubbles. In this presentation we introduce a new technique for measuring the surface dilatational viscosity by contracting an aqueous pendant drop attached to a needle tip and having and insoluble surfactant monolayer at the air-water interface. The isotropic total tension on the surface consists of the equilibrium surface tension and the tension due to the dilation. Compression rates are undertaken slow enough so that bulk hydrodynamic stresses are small compared to the surface tension force. Under these conditions we show that the total tension is uniform along the surface and that the Young-Laplace equation governs the drop shape with the equilibrium surface tension replaced by the constant surface isotropic stress. We illustrate this technique using

  3. Behavior of lysozyme adsorbed onto biological liquid crystal lipid monolayer at the air/water interface

    Science.gov (United States)

    Lu, Xiaolong; Shi, Ruixin; Hao, Changchun; Chen, Huan; Zhang, Lei; Li, Junhua; Xu, Guoqing; Sun, Runguang

    2016-09-01

    The interaction between proteins and lipids is one of the basic problems of modern biochemistry and biophysics. The purpose of this study is to compare the penetration degree of lysozyme into 1,2-diapalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoethano-lamine (DPPE) by analyzing the data of surface pressure–area (π–A) isotherms and surface pressure–time (π–T) curves. Lysozyme can penetrate into both DPPC and DPPE monolayers because of the increase of surface pressure at an initial pressure of 15 mN/m. However, the changes of DPPE are larger than DPPC, indicating stronger interaction of lysozyme with DPPE than DPPC. The reason may be due to the different head groups and phase state of DPPC and DPPE monolayers at the surface pressure of 15 mN/m. Atomic force microscopy reveals that lysozyme was absorbed by DPPC and DPPE monolayers, which leads to self-aggregation and self-assembly, forming irregular multimers and conical multimeric. Through analysis, we think that the process of polymer formation is similar to the aggregation mechanism of amyloid fibers. Project supported by the National Natural Science Foundation of China (Grant Nos. 21402114 and 11544009), the Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2016JM2010), the Fundamental Research Funds for the Central Universities of China (Grant No. GK201603026), and the National University Science and Technology Innovation Project of China (Grant No. 201610718013).

  4. Effect of cation enrichment on dipalmitoylphosphatidylcholine (DPPC) monolayers at the air-water interface.

    Science.gov (United States)

    Adams, Ellen M; Casper, Clayton B; Allen, Heather C

    2016-09-15

    The effect of highly concentrated salt solutions of marine-relevant cations (Na(+), K(+), Mg(2+), and Ca(2+)) on Langmuir monolayers of dipalmitoylphosphatidylcholine (DPPC) was investigated by means of surface pressure-area isotherms, Brewster angle microscopy (BAM), and infrared reflection-absorption spectroscopy (IRRAS). It was found that monovalent cations and Mg(2+) have similar phase behavior, causing DPPC monolayers to expand, while Ca(2+) induces condensation. All cations disrupted the surface morphology at high cation concentration, resulting in decreased reflectivity from the monolayer. Monolayer refractive index was calculated from BAM image intensity in the liquid condensed phase and decreased with increasing cation concentration, which suggests that orientation of the alkyl chains change. Monovalent ions increase ordering of the alkyl chains, more than divalents, yet have little interaction with the DPPC headgroup. Mg(2+) induces gauche defects in the alkyl chain and increases headgroup hydration at low lipid coverage but increases chain ordering and dehydrates the headgroup at high lipid coverage. Ca(2+) orders alkyl chains and dehydrates the phosphate moiety, independent of lipid phase. At the highest salt concentration investigated, significant narrowing of the asymmetric PO2(-) vibrational mode occurs and is attributed to considerable dehydration of the DPPC headgroup. PMID:27322949

  5. Experimental investigation of droplet separation in a horizontal counter-current air/water stratified flow

    International Nuclear Information System (INIS)

    A stratified counter-current two-phase gas/liquid flow can occur in various technical systems. In the past investigations have mainly been motivated by the possible occurrence of these flows in accident scenarios of nuclear light water-reactors and in numerous applications in process engineering. However, the precise forecast of flow parameters, is still challenging, for instance due to their strong dependency on the geometric boundary conditions. A new approach which uses CFD methods (Computational Fluid Dynamics) promises a better understanding of the flow phenomena and simultaneously a higher scalability of the findings. RANS methods (Reynolds Averaged Navier Stokes) are preferred in order to compute industrial processes and geometries. A very deep understanding of the flow behavior and equation systems based on real physics are necessary preconditions to develop the equation system for a reliable RANS approach with predictive power. Therefore, local highly resolved, experimental data is needed in order to provide and validate the required turbulence and phase interaction models. The central objective of this work is to provide the data needed for the code development for these unsteady, turbulent and three-dimensional flows. Experiments were carried out at the WENKA facility (Water Entrainment Channel Karlsruhe) at the Karlsruhe Institute of Technology (KIT). The work consists of a detailed description of the test-facility including a new bended channel, the measurement techniques and the experimental results. The characterization of the new channel was done by flow maps. A high-speed imaging study gives an impression of the occurring flow regimes, and different flow phenomena like droplet separation. The velocity distributions as well as various turbulence values were investigated by particle image velocimetry (PIV). In the liquid phase fluorescent tracer-particles were used to suppress optical reflections from the phase surface (fluorescent PIV, FPIV

  6. Oxidation of monolayers of partly converted dimethoxy-substituted poly(p-phenylenevinylene) precursor polymers at the air-water interface

    NARCIS (Netherlands)

    Hagting, J.G.; Schouten, A.J.; Hagting, A

    2000-01-01

    We observed that the poly(p-phenylenevinylene) units in Langmuir monolayers of partly converted dimethoxy-substituted poly(p-phenylenevinylene) precursor polymers oxidize at the air-water interface. This reaction even happened in the dark and therefore can not be attributed to a photooxygenation rea

  7. DIFFUSIVE EXCHANGE OF GASEOUS POLYCYCLIC AROMATIC HYDROCARBONS AND POLYCHLORINATED BIPHENYLS ACROSS THE AIR-WATER INTERFACE OF THE CHESAPEAKE BAY. (R825245)

    Science.gov (United States)

    Dissolved and gas-phase concentrations of nine polycyclic aromatic hydrocarbons and 46 polychlorinated biphenyl congeners were measured at eight sites on the Chesapeake Bay at four different times of the year to estimate net diffusive air-water gas exchange rates. Gaseous PAHs ar...

  8. Simulating the Vapour Phase Air/Water Exchange of p,p′-DDE, p,p′-DDT, Lindane, and 2,3,7,8-Tetrachlorodibenzodioxin

    Science.gov (United States)

    Uncertainties in our understanding of gaseous air/water exchange have emerged as major sources of concern in efforts to construct global and regional mass balances of both the green house gas carbon dioxide and semi-volatile persistent, bioaccumulative and toxic chemicals. Hoff e...

  9. Hydrophobic recovery of repeatedly plasma-treated silicone rubber .2. A comparison of the hydrophobic recovery in air, water, or liquid nitrogen

    NARCIS (Netherlands)

    Everaert, EP; VanderMei, HC; Busscher, HJ

    1996-01-01

    Surfaces of medical grade silicone rubber (Q7-4750, Dow Coming) were modified by repeated (six times) RF plasma treatments using various discharge gases: oxygen, argon, carbon dioxide, and ammonia. The treated samples were stored for a period of 3 months in ambient air, water, or liquid nitrogen. Su

  10. Modulation of the adsorption properties at air-water interfaces of complexes of egg white ovalbumin with pectin by the dielectric constant

    NARCIS (Netherlands)

    Kudryashova, E.V.; Jongh, H.H.J.de

    2008-01-01

    The possibility of modulating the mesoscopic properties of food colloidal systems by the dielectric constant is studied by determining the impact of small amounts of ethanol (10%) on the adsorption of egg white ovalbumin onto the air-water interface in the absence and presence of pectin. The adsorpt

  11. The adsorption and unfolding kinetics determines the folding state of proteins at the air-water interface and thereby the equation of state

    NARCIS (Netherlands)

    Wierenga, P.A.; Egmond, M.R.; Voragen, A.G.J.; Jongh, H.H.J.de

    2006-01-01

    Unfolding of proteins has often been mentioned as an important factor during the adsorption process at air-water interfaces and in the increase of surface pressure at later stages of the adsorption process. This work focuses on the question whether the folding state of the adsorbed protein depends o

  12. A numerical scheme to calculate temperature and salinity dependent air-water transfer velocities for any gas

    Directory of Open Access Journals (Sweden)

    M. T. Johnson

    2010-02-01

    Full Text Available The transfer velocity determines the rate of exchange of a gas across the air-water interface for a given deviation from Henry's law equilibrium between the two phases. In the thin film model of gas exchange, which is commonly used for calculating gas exchange rates from measured concentrations of trace gases in the atmosphere and ocean/freshwaters, the overall transfer is controlled by diffusion-mediated films on either side of the air-water interface. Calculating the total transfer velocity (i.e. including the influence from both molecular layers requires the Henry's law constant and the Schmidt number of the gas in question, the latter being the ratio of the viscosity of the medium and the molecular diffusivity of the gas in the medium. All of these properties are both temperature and (on the water side salinity dependent and extensive calculation is required to estimate these properties where not otherwise available. The aim of this work is to standardize the application of the thin film approach to flux calculation from measured and modelled data, to improve comparability, and to provide a numerical framework into which future parameter improvements can be integrated. A detailed numerical scheme is presented for the calculation of the gas and liquid phase transfer velocities (ka and kw respectively and the total transfer velocity, K. The scheme requires only basic physical chemistry data for any gas of interest and calculates K over the full range of temperatures, salinities and wind-speeds observed in and over the ocean. Improved relationships for the wind-speed dependence of ka and for the salinity-dependence of the gas solubility (Henry's law are derived. Comparison with alternative schemes and methods for calculating air-sea flux parameters shows good agreement in general but significant improvements under certain conditions. The scheme is provided as a downloadable

  13. Gaseous and Freely-Dissolved PCBs in the Lower Great Lakes Based on Passive Sampling: Spatial Trends and Air-Water Exchange.

    Science.gov (United States)

    Liu, Ying; Wang, Siyao; McDonough, Carrie A; Khairy, Mohammed; Muir, Derek C G; Helm, Paul A; Lohmann, Rainer

    2016-05-17

    Polyethylene passive sampling was performed to quantify gaseous and freely dissolved polychlorinated biphenyls (PCBs) in the air and water of Lakes Erie and Ontario during 2011-2012. In view of differing physical characteristics and the impacts of historical contamination by PCBs within these lakes, spatial variation of PCB concentrations and air-water exchange across these lakes may be expected. Both lakes displayed statistically similar aqueous and atmospheric PCB concentrations. Total aqueous concentrations of 29 PCBs ranged from 1.5 pg L(-1) in the open lake of Lake Erie (site E02) in 2011 spring to 105 pg L(-1) in Niagara (site On05) in 2012 summer, while total atmospheric concentrations were 7.7-634 pg m(-3) across both lakes. A west-to-east gradient was observed for aqueous PCBs in Lake Erie. River discharge and localized influences (e.g., sediment resuspension and regional alongshore transport) likely dominated spatial trends of aqueous PCBs in both lakes. Air-water exchange fluxes of Σ7PCBs ranged from -2.4 (±1.9) ng m(-2) day(-1) (deposition) in Sheffield (site E03) to 9.0 (±3.1) ng m(-2) day(-1) (volatilization) in Niagara (site On05). Net volatilization of PCBs was the primary trend across most sites and periods. Almost half of variation in air-water exchange fluxes was attributed to the difference in aqueous concentrations of PCBs. Uncertainty analysis in fugacity ratios and mass fluxes in air-water exchange of PCBs indicated that PCBs have reached or approached equilibrium only at the eastern Lake Erie and along the Canadian shore of Lake Ontario sites, where air-water exchange fluxes dominated atmospheric concentrations. PMID:26642083

  14. Characterization of atmospheric pressure plasma treated pure cashmere and wool/cashmere textiles: Treatment in air/water vapor mixture

    Energy Technology Data Exchange (ETDEWEB)

    Zanini, Stefano, E-mail: stefano.zanini@mib.infn.it [Università degli Studi di Milano-Bicocca, Dipartimento di Fisica “G. Occhialini”, p.za della Scienza, 3, I-20126 Milano (Italy); Grimoldi, Elisa [Università degli Studi di Milano-Bicocca, Dipartimento di Fisica “G. Occhialini”, p.za della Scienza, 3, I-20126 Milano (Italy); Citterio, Attilio [Politecnico di Milano, Dipartimento di Chimica, Materiali ed Ingegneria Chimica “G. Natta”, Via Mancinelli 7, I-20131 Milano (Italy); Riccardi, Claudia, E-mail: riccardi@mib.infn.it [Università degli Studi di Milano-Bicocca, Dipartimento di Fisica “G. Occhialini”, p.za della Scienza, 3, I-20126 Milano (Italy)

    2015-09-15

    Highlights: • We treated cashmere and wool/cashmere textiles with atmospheric pressure plasma. • Wettability of the fabrics was increased. • The increment in wettability derived from a surface oxidation of the fibers. • Only minor etching effects were observed with scanning electron microscopy. - Abstract: We performed atmospheric pressure plasma treatments of pure cashmere and wool/cashmere textiles with a dielectric barrier discharge (DBD) in humid air (air/water vapor mixtures). Treatment parameters have been optimized in order to enhance the wettability of the fabrics without changing their bulk properties as well as their touch. A deep characterization has been performed to study the wettability, the surface morphologies, the chemical composition and the mechanical properties of the plasma treated textiles. The chemical properties of the plasma treated samples were investigated with attenuated total reflectance Fourier transform infrared (FTIR/ATR) spectroscopy and X-ray photoelectron microscopy (XPS). The analyses reveal a surface oxidation of the treated fabrics, which enhances their surface wettability. Morphological characterization of the treated fibers with scanning electron microscopy (SEM) reveals minor etching effects, an essential feature for the maintenance of the textile softness.

  15. Effect of flow obstacle on droplet sizes in vertical annular air-water flow in a small diameter pipe

    International Nuclear Information System (INIS)

    Droplet size distributions have been measured for air-water annular-mist flow in a vertical 12.0 mm diameter pipe at atmospheric pressure. A laser diffraction technique has been employed using a Malvern Spraytec instrument. The test section was specially designed for meticulous measurement in the present experiment: any optical windows were not used to avoid problems arose from glass contamination by sucking the liquid film through the wall just below the measurement elevation. Sauter mean diameters measured in this work decreased simply with an increase of air superficial velocity, whereas the dependence on water superficial velocity showed complicated dependency on air velocity. The effect of a flow obstacle on droplet size distribution was also investigated. A small tube was placed in the centerline of the test section as an obstacle. Three obstacles having different blockage ratio were tested. It is found through the present experiments that the obstacle effect is not so significant for the blockage ratio of up to 0.3, and the droplet diameter decreases to approximately 80% in average. Based on the data, an empirical correlation to predict Sauter diameter was developed by modifying the existing correlation. A hydraulic equivalent diameter that takes account of the blockage ratio is applied to the characteristic length in the correlation. (author)

  16. Spatial Distribution, Air-Water Fugacity Ratios and Source Apportionment of Polychlorinated Biphenyls in the Lower Great Lakes Basin.

    Science.gov (United States)

    Khairy, Mohammed; Muir, Derek; Teixeira, Camilla; Lohmann, Rainer

    2015-12-01

    Polychlorinated biphenyls (PCBs) continue to be contaminants of concern across the Great Lakes. It is unclear whether current concentrations are driven by ongoing primary emissions from their original uses, or whether ambient PCBs are dominated by their environmental cycling. Freely dissolved PCBs in air and water were measured using polyethylene passive samplers across Lakes Erie and Ontario during summer and fall, 2011, to investigate their spatial distribution, determine and apportion their sources and to asses their air-water exchange gradients. Average gaseous and freely dissolved ∑29 PCB concentrations ranged from 5.0 to 160 pg/m(3) and 2.0 to 55 pg/L respectively. Gaseous concentrations were significantly correlated (R(2) = 0.80) with the urban area within a 3-20 km radius. Fugacity ratios indicated that the majority of PCBs are volatilizing from the water thus acting as a secondary source for the atmosphere. Dissolved PCBs were probably linked to PCB emissions from contaminated sites and areas of concern. Positive matrix factorization indicated that although volatilized Aroclors (gaseous PCBs) and unaltered Aroclors (dissolved PCBs) dominate in some samples, ongoing non-Aroclor sources such as paints/pigments (PCB 11) and coal/wood combustion showed significant contributions across the lower Great Lakes. Accordingly, control strategies should give further attention to PCBs emitted from current use sources.

  17. Thermal Characteristics of Air-Water Spray Impingement Cooling of Hot Metallic Surface under Controlled Parametric Conditions

    Institute of Scientific and Technical Information of China (English)

    Santosh Kumar Nayak; Purna Chandra Mishra

    2016-01-01

    Experimental results on the thermal characteristics of air-water spray impingement cooling of hot metallic surface are presented and discussed in this paper.The controlling input parameters investigated were the combined air and water pressures,plate thickness,water flow rate,nozzle height from the target surface and initial temperature of the hot surface.The effects of these input parameters on the important thermal characteristics such as heat transfer rate,heat transfer coefficient and wetting front movement were measured and examined.Hot flat plate samples of mild steel with dimension 120 mm in length,120 mm breadth and thickness of 4 mm,6 mm,and 8 mm respectively were tested.The air assisted water spray was found to be an effective cooling media and method to achieve very high heat transfer rate from the surface.Higher heat transfer rate and heat transfer coefficients were obtained for the lesser i.e,4 mm thick plates.Increase in the nozzle height reduced the heat transfer efficiency of spray cooling.At an inlet water pressure of 4 bar and air pressure of 3 bar,maximum cooling rates 670℃/s and average cooling rate of 305.23℃/s were achieved for a temperature of 850℃ of the steel plate.

  18. Thermal characteristics of air-water spray impingement cooling of hot metallic surface under controlled parametric conditions

    Science.gov (United States)

    Nayak, Santosh Kumar; Mishra, Purna Chandra

    2016-06-01

    Experimental results on the thermal characteristics of air-water spray impingement cooling of hot metallic surface are presented and discussed in this paper. The controlling input parameters investigated were the combined air and water pressures, plate thickness, water flow rate, nozzle height from the target surface and initial temperature of the hot surface. The effects of these input parameters on the important thermal characteristics such as heat transfer rate, heat transfer coefficient and wetting front movement were measured and examined. Hot flat plate samples of mild steel with dimension 120 mm in length, 120 mm breadth and thickness of 4 mm, 6 mm, and 8 mm respectively were tested. The air assisted water spray was found to be an effective cooling media and method to achieve very high heat transfer rate from the surface. Higher heat transfer rate and heat transfer coefficients were obtained for the lesser i.e, 4 mm thick plates. Increase in the nozzle height reduced the heat transfer efficiency of spray cooling. At an inlet water pressure of 4 bar and air pressure of 3 bar, maximum cooling rates 670°C/s and average cooling rate of 305.23°C/s were achieved for a temperature of 850°C of the steel plate.

  19. The use of CFD code for numerical simulation study on the air/water countercurrent flow limitation in nuclear reactors

    International Nuclear Information System (INIS)

    For the experimental study on the air/water countercurrent flow limitation in Nuclear Reactors, were built at CDTN an acrylic test sections with the same geometric shape of 'hot leg' of a Pressurized Water Reactor (PWR). The hydraulic circuit is designed to be used with air and water at pressures near to atmospheric and ambient temperature. Due to the complexity of the CCFL experimental, the numerical simulation has been used. The aim of the numerical simulations is the validation of experimental data. It is a global trend, the use of computational fluid dynamics (CFD) modeling and prediction of physical phenomena related to heat transfer in nuclear reactors. The most used CFD codes are: FLUENT®, STAR- CD®, Open Foam® and CFX®. In CFD, closure models are required that must be validated, especially if they are to be applied to nuclear reactor safety. The Thermal- Hydraulics Laboratory of CDTN offers computing infrastructure and license to use commercial code CFX®. This article describes a review about CCFL and the use of CFD for numerical simulation of this phenomenal for Nuclear Rector. (author)

  20. Exchange of polycyclic aromatic hydrocarbons across the air-water interface in the Bohai and Yellow Seas

    Science.gov (United States)

    Chen, Yingjun; Lin, Tian; Tang, Jianhui; Xie, Zhiyong; Tian, Chongguo; Li, Jun; Zhang, Gan

    2016-09-01

    In this study, air and surface seawater samples collected from the Bohai (BS) and Yellow Seas (YS) in May 2012 were determined exchange of PAHs, especially of low-molecular-weight (LMW) PAHs (three- and four-ring PAHs) at the air-water interface. Net volatilization fluxes of LMW PAHs were 266-1454 ng/m2/d and decreased with distance from the coast, indicating that these PAHs transported from coastal runoff were potential contributors to the atmosphere in the BS and YS. Moreover, LMW PAHs were enriched in the dissolved phase compared with those in the particulate phase in the water column, possibly suggesting that the volatilized LMW PAHs were directly derived from wastewater discharge or petroleum pollution rather than released from contaminated sediments. The air-sea exchange fluxes of the three-ring PAHs were 2- to 20-fold higher than their atmospheric deposition fluxes in the BS and YS. The input to and output from the water reached equilibrium for four-ring PAHs. Differently, five- and six-ring PAHs were introduced into the marine environment primarily through dry and wet deposition, indicating that the water column was still a sink of these PAHs from the surrounding atmosphere.

  1. Spatial Distribution, Air-Water Fugacity Ratios and Source Apportionment of Polychlorinated Biphenyls in the Lower Great Lakes Basin.

    Science.gov (United States)

    Khairy, Mohammed; Muir, Derek; Teixeira, Camilla; Lohmann, Rainer

    2015-12-01

    Polychlorinated biphenyls (PCBs) continue to be contaminants of concern across the Great Lakes. It is unclear whether current concentrations are driven by ongoing primary emissions from their original uses, or whether ambient PCBs are dominated by their environmental cycling. Freely dissolved PCBs in air and water were measured using polyethylene passive samplers across Lakes Erie and Ontario during summer and fall, 2011, to investigate their spatial distribution, determine and apportion their sources and to asses their air-water exchange gradients. Average gaseous and freely dissolved ∑29 PCB concentrations ranged from 5.0 to 160 pg/m(3) and 2.0 to 55 pg/L respectively. Gaseous concentrations were significantly correlated (R(2) = 0.80) with the urban area within a 3-20 km radius. Fugacity ratios indicated that the majority of PCBs are volatilizing from the water thus acting as a secondary source for the atmosphere. Dissolved PCBs were probably linked to PCB emissions from contaminated sites and areas of concern. Positive matrix factorization indicated that although volatilized Aroclors (gaseous PCBs) and unaltered Aroclors (dissolved PCBs) dominate in some samples, ongoing non-Aroclor sources such as paints/pigments (PCB 11) and coal/wood combustion showed significant contributions across the lower Great Lakes. Accordingly, control strategies should give further attention to PCBs emitted from current use sources. PMID:25915412

  2. Concentrations, Trends, and Air-Water Exchange of PAHs and PBDEs Derived from Passive Samplers in Lake Superior in 2011.

    Science.gov (United States)

    Ruge, Zoe; Muir, Derek; Helm, Paul; Lohmann, Rainer

    2015-12-01

    Polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenylethers (PBDEs) are both currently released into the environment from anthropogenic activity. Both are hence primarily associated with populated or industrial areas, although wildfires can be an important source of PAHs, as well. Polyethylene passive samplers (PEs) were simultaneously deployed in surface water and near surface atmosphere to determine spatial trends and air-water gaseous exchange of 21 PAHs and 11 PBDEs at 19 sites across Lake Superior in 2011. Surface water and atmospheric PAH concentrations were greatest at urban sites (up to 65 ng L(-1) and 140 ng m(-3), respectively, averaged from June to October). Near populated regions, PAHs displayed net air-to-water deposition, but were near equilibrium off-shore. Retene, probably depositing following major wildfires in the region, dominated dissolved PAH concentrations at most Lake Superior sites. Atmospheric and dissolved PBDEs were greatest near urban and populated sites (up to 6.8 pg L(-1) and 15 pg m(-3), respectively, averaged from June to October), dominated by BDE-47. At most coastal sites, there was net gaseous deposition of BDE-47, with less brominated congeners contributing to Sault Ste. Marie and eastern open lake fluxes. Conversely, the central open lake and Eagle Harbor sites generally displayed volatilization of PBDEs into the atmosphere, mainly BDE-47. PMID:26436513

  3. Voidage Measurement of Air-Water Two-phase Flow Based on ERT Sensor and Data Mining Technology

    Institute of Scientific and Technical Information of China (English)

    王保良; 孟振振; 黄志尧; 冀海峰; 李海青

    2012-01-01

    Based on an electrical resistance tomography(ERT) sensor and the data mining technology,a new voidage measurement method is proposed for air-water two-phase flow.The data mining technology used in this work is a least squares support vector machine(LS-SVM) algorithm together with the feature extraction method,and three feature extraction methods are tested:principal component analysis(PCA),partial least squares(PLS) and independent component analysis(ICA).In the practical voidage measurement process,the flow pattern is firstly identified directly from the conductance values obtained by the ERT sensor.Then,the appropriate voidage measurement model is selected according to the flow pattern identification result.Finally,the voidage is calculated.Experimental results show that the proposed method can measure the voidage effectively,and the measurement accuracy and speed are satisfactory.Compared with the conventional voidage measurement methods based on ERT,the proposed method doesn't need any image reconstruction process,so it has the advantage of good real-time performance.Due to the introduction of flow pattern identification,the influence of flow pattern on the voidage measurement is overcome.Besides,it is demonstrated that the LS-SVM method with PLS feature extraction presents the best measurement performance among the tested methods.

  4. Effect of the spacer group on the behavior of the cationic Gemini surfactant monolayer at the air/water interface

    Energy Technology Data Exchange (ETDEWEB)

    Chen Qibin; Zhang Dazhi; Li Rong [State Key Laboratory of Chemical Engineering and Department of Chemistry, East China University of Science and Technology, Shanghai 200237 (China); Liu Honglai [State Key Laboratory of Chemical Engineering and Department of Chemistry, East China University of Science and Technology, Shanghai 200237 (China)], E-mail: hlliu@ecust.edu.cn; Hu Ying [State Key Laboratory of Chemical Engineering and Department of Chemistry, East China University of Science and Technology, Shanghai 200237 (China)

    2008-10-01

    Surface properties of the insoluble cationic bis-(quaternary ammonium halide) surfactants (Gemini) with polymethylene spacer at the air/water interface were investigated. The monolayers were transferred onto mica by the Langmuir-Blodgett (LB) technique and the corresponding LB films were characterized by the atomic force microscopy (AFM) and the contact angle of water. For the Gemini surfactants with the different spacer length, it was found that the surface pressure-molecular area isotherms resemble to each other. The limiting area increases rapidly and almost linearly with the increase of spacer length for the short spacers, but reaches a maximum at s = 10 and decreases slightly at s > 10. The AFM images show that the surface micelles and the multilayer aggregates gradually appear with the increase of surface pressure. No matter what the surface pressures are, the main structure of the monolayer almost keeps the same, which suggested that the major molecules lie nearly flat on the water surface, while the increase of surface pressure forces the minor alkyl chains to turn only partly or completely vertical to the water surface and even to overturn. This is the cause that the contact angle of water on LB film increases slightly with the surface pressure.

  5. Characterization of atmospheric pressure plasma treated pure cashmere and wool/cashmere textiles: Treatment in air/water vapor mixture

    International Nuclear Information System (INIS)

    Highlights: • We treated cashmere and wool/cashmere textiles with atmospheric pressure plasma. • Wettability of the fabrics was increased. • The increment in wettability derived from a surface oxidation of the fibers. • Only minor etching effects were observed with scanning electron microscopy. - Abstract: We performed atmospheric pressure plasma treatments of pure cashmere and wool/cashmere textiles with a dielectric barrier discharge (DBD) in humid air (air/water vapor mixtures). Treatment parameters have been optimized in order to enhance the wettability of the fabrics without changing their bulk properties as well as their touch. A deep characterization has been performed to study the wettability, the surface morphologies, the chemical composition and the mechanical properties of the plasma treated textiles. The chemical properties of the plasma treated samples were investigated with attenuated total reflectance Fourier transform infrared (FTIR/ATR) spectroscopy and X-ray photoelectron microscopy (XPS). The analyses reveal a surface oxidation of the treated fabrics, which enhances their surface wettability. Morphological characterization of the treated fibers with scanning electron microscopy (SEM) reveals minor etching effects, an essential feature for the maintenance of the textile softness

  6. Assessment of MARS 2.0 for direct DVI bypass during LBLOCA reflood using KAERI air-water DVI tests

    International Nuclear Information System (INIS)

    MARS code has been assessed for the direct ECC (Emergency Core Cooling) bypass that occurs during LBLOCA reflood of KNGR (Korean Next Generation Reactor) using the KAERI air-water DVI (Direct Vessel Injection) tests that are 1/50 scale-down tests simulating the LBLOCA reflood of KNGR. Assessment matrix is selected for the single and double DVI configurations with typical LBLOCA reflood conditions, that is, DVI injection velocity of 1.0 ∼ 1.6 m/sec and air injection velocity of 20 ∼ 35 m/sec. First, the MARS calculation is adjusted to match the DVI film distribution with the 1/50 scale test results, then the code assessments are carried out for the selected direct DVI bypass tests using the adjusted DVI film distribution. From the assessments, it has been found that the MARS is capable of predicting the direct DVI bypass phenomena as well as the multi-dimensional thermal hydraulics in the downcomer

  7. The use of CFD code for numerical simulation study on the air/water countercurrent flow limitation in nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Morghi, Youssef; Mesquita, Amir Zacarias; Santos, Andre Augusto Campagnole dos; Vasconcelos, Victor, E-mail: ymo@cdtn.br, E-mail: amir@cdtn.br, E-mail: aacs@cdtn.br, E-mail: vitors@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    For the experimental study on the air/water countercurrent flow limitation in Nuclear Reactors, were built at CDTN an acrylic test sections with the same geometric shape of 'hot leg' of a Pressurized Water Reactor (PWR). The hydraulic circuit is designed to be used with air and water at pressures near to atmospheric and ambient temperature. Due to the complexity of the CCFL experimental, the numerical simulation has been used. The aim of the numerical simulations is the validation of experimental data. It is a global trend, the use of computational fluid dynamics (CFD) modeling and prediction of physical phenomena related to heat transfer in nuclear reactors. The most used CFD codes are: FLUENT®, STAR- CD®, Open Foam® and CFX®. In CFD, closure models are required that must be validated, especially if they are to be applied to nuclear reactor safety. The Thermal- Hydraulics Laboratory of CDTN offers computing infrastructure and license to use commercial code CFX®. This article describes a review about CCFL and the use of CFD for numerical simulation of this phenomenal for Nuclear Rector. (author)

  8. Experimental study for flow regime of downward air-water two-phase flow in a vertical narrow rectangular channel

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T. H.; Yun, B. J.; Jeong, J. H. [Pusan National University, Geunjeong-gu, Busan (Korea, Republic of)

    2015-05-15

    Studies were mostly about flow in upward flow in medium size circular tube. Although there are great differences between upward and downward flow, studies on vertical upward flow are much more active than those on vertical downward flow in a channel. In addition, due to the increase of surface forces and friction pressure drop, the pattern of gas-liquid two-phase flow bounded to the gap of inside the rectangular channel is different from that in a tube. The downward flow in a rectangular channel is universally applicable to cool the plate type nuclear fuel in research reactor. The sub-channel of the plate type nuclear fuel is designed with a few millimeters. Downward air-water two-phase flow in vertical rectangular channel was experimentally observed. The depth, width, and length of the rectangular channel is 2.35 mm, 66.7 mm, and 780 mm, respectively. The test section consists of transparent acrylic plates confined within a stainless steel frame. The flow patterns of the downward flow in high liquid velocity appeared to be similar to those observed in previous studies with upward flow. In downward flow, the transition lines for bubbly-slug and slug-churn flow shift to left in the flow regime map constructed with abscissa of the superficial gas velocity and ordinate of the superficial liquid velocity. The flow patterns observed with downward flow at low liquid velocity are different from those with upward flow.

  9. DNS and measurements of scalar transfer across an air-water interface during inception and growth of Langmuir circulation

    Science.gov (United States)

    Hafsi, A.; Ma, Y.; Buckley, M.; Tejada-Martinez, A. E.; Veron, F.

    2016-05-01

    Direct numerical simulations (DNS) of an initially quiescent coupled air-water interface driven by an air flow with free stream speed of 5 m/s have been conducted and scalar transfer from the air side to the water side and subsequent vertical transport in the water column have been analysed. Two simulations are compared: one with a freely deforming interface, giving rise to gravity-capillary waves and aqueous Langmuir turbulence (LT) characterized by small-scale (centimeter-scale) Langmuir cells (LC), and the other with the interface intentionally held flat, i.e., without LC. It is concluded that LT serves to enhance vertical transport of the scalar in the water side and in the process increases scalar transfer efficiency from the air side to the water side relative to the shear-dominated turbulence in the flat interface case. Furthermore, transition to LT was observed to be accompanied by a spike in scalar flux characterized by an order of magnitude increase. These episodic flux increases, if linked to gusts and overall unsteadiness in the wind field, are expected to be an important contributor in determining the long-term average of the air-sea gas fluxes.

  10. Preliminary Analysis on Heat Removal Capacity of Passive Air-Water Combined Cooling Heat Exchanger Using MARS

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung-Sin; Jeon, Seong-Su; Hong, Soon-Joon [FNC Tech, Yongin (Korea, Republic of); Bae, Sung-Won; Kwon, Tae-Soon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Current design requirement for working time of PAFS heat exchanger is about 8 hours. Thus, it is not satisfied with the required cooling capability for the long term SBO(Station Black-Out) situation that is required to over 72 hours cooling. Therefore PAFS is needed to change of design for 72 hours cooling. In order to acquirement of long terms cooling using PAFS, heat exchanger tube has to be submerged in water tank for long time. However, water in the tank is evaporated by transferred heat from heat exchanger tubes, so water level is gradually lowered as time goes on. The heat removal capacity of air cooling heat exchanger is core parameter that is used for decision of applicability on passive air-water combined cooling system using PAFS in long term cooling. In this study, the development of MARS input model and plant accident analysis are performed for the prediction of the heat removal capacity of air cooling heat exchanger. From analysis result, it is known that inflow air velocity is the decisive factor of the heat removal capacity and predicted air velocity is lower than required air velocity. But present heat transfer model and predicted air velocity have uncertainty. So, if changed design of PAFS that has over 4.6 kW heat removal capacity in each tube, this type heat exchanger can be applied to long term cooling of the nuclear power plant.

  11. Exchange of polycyclic aromatic hydrocarbons across the air-water interface in the Bohai and Yellow Seas

    Science.gov (United States)

    Chen, Yingjun; Lin, Tian; Tang, Jianhui; Xie, Zhiyong; Tian, Chongguo; Li, Jun; Zhang, Gan

    2016-09-01

    In this study, air and surface seawater samples collected from the Bohai (BS) and Yellow Seas (YS) in May 2012 were determined exchange of PAHs, especially of low-molecular-weight (LMW) PAHs (three- and four-ring PAHs) at the air-water interface. Net volatilization fluxes of LMW PAHs were 266-1454 ng/m2/d and decreased with distance from the coast, indicating that these PAHs transported from coastal runoff were potential contributors to the atmosphere in the BS and YS. Moreover, LMW PAHs were enriched in the dissolved phase compared with those in the particulate phase in the water column, possibly suggesting that the volatilized LMW PAHs were directly derived from wastewater discharge or petroleum pollution rather than released from contaminated sediments. The air-sea exchange fluxes of the three-ring PAHs were 2- to 20-fold higher than their atmospheric deposition fluxes in the BS and YS. The input to and output from the water reached equilibrium for four-ring PAHs. Differently, five- and six-ring PAHs were introduced into the marine environment primarily through dry and wet deposition, indicating that the water column was still a sink of these PAHs from the surrounding atmosphere.

  12. Air-water partition coefficients for a suite of polycyclic aromatic and other C10 through C20 unsaturated hydrocarbons.

    Science.gov (United States)

    Rayne, Sierra; Forest, Kaya

    2016-09-18

    The air-water partition coefficients (Kaw) for 86 large polycyclic aromatic hydrocarbons and their unsaturated relatives were estimated using high-level G4(MP2) gas and aqueous phase calculations with the SMD, IEFPCM-UFF, and CPCM solvation models. An extensive method validation effort was undertaken which involved confirming that, via comparisons to experimental enthalpies of formation, gas-phase energies at the G4(MP2) level for the compounds of interest were at or near thermochemical accuracy. Investigations of the three solvation models using a range of neutral and ionic compounds suggested that while no clear preferential solvation model could be chosen in advance for accurate Kaw estimates of the target compounds, the employment of increasingly higher levels of theory would result in lower Kaw errors. Subsequent calculations on the polycyclic aromatic and unsaturated hydrocarbons at the G4(MP2) level revealed excellent agreement for the IEFPCM-UFF and CPCM models against limited available experimental data. The IEFPCM-UFF-G4(MP2) and CPCM-G4(MP2) solvation energy calculation approaches are anticipated to give Kaw estimates within typical experimental ranges, each having general Kaw errors of less than 0.5 log10 units. When applied to other large organic compounds, the method should allow development of a broad and reliable Kaw database for multimedia environmental modeling efforts on various contaminants. PMID:27336293

  13. Langmuir and Langmuir-Blodgett films of capsules of haemoglobin at air/water and solid/air interfaces

    Indian Academy of Sciences (India)

    J Maheshkumar; A Dhathathreyan

    2013-03-01

    Organized assemblies of capsules of haemoglobin (Hb), in the size range of 0.1 to 0.3 in Langmuir films have been studied at air/water interface below and above the isoelectric point. Spread films of these organizates suggest that there is no expulsion of individual particles or particle assemblies at the interface and the particles are stable. Dynamic surface tension and the associated dilational and shear visco-elasticity in these films suggest that the capsules are highly elastic. Multilayer films of the capsules using Langmuir-Blodgett technique have been fabricated by sequential deposition on solid surfaces. These films have been characterized by circular dichroism spectroscopy (CD), atomic force microscopy (AFM), quartz crystal microbalance (QCM) and Fourier transform infrared with reflection absorption spectroscopy (FTIR-RAS). No appreciable change in the secondary structural features of Hb is seen from CD studies indicating the stability of the protein in these organized assemblies. Sizes of these capsules change near the isoelectric point and large swollen multiwalled capsules are formed. The elastic films of capsules of Hb provide a useful post preparation approach for modification of the surface roughness, porosity, and permeability of pre-assembled polypeptide microcapsules.

  14. Numerical simulation of slug flow regime for an air water two-phase flow in horizontal pipes

    International Nuclear Information System (INIS)

    Slug flow is a quite common multiphase flow regime in horizontal pipelines and channels, which can be potentially hazardous to the structure of the pipe system or to apparatus and processes following the slug flow pipe section due to the strong oscillating pressure levels formed behind liquid slugs. Areas of application are in the chemical and process industry as well as in safety research and thermo-hydraulic engineering for nuclear power plants. The intended paper deals with the feasibility and accuracy of CFD simulations for an air-water slug flow in a horizontal circular pipe of diameter D = 0.054 m and a pipe length of up to 8 m. In the past most investigations of the slug flow regime in horizontal pipelines and channels have been carried out on experimental test rigs. Due to the transient and three-dimensional character of slug flow regime and the resulting numerical effort only a few attempts of numerical simulation have been made. In principal three different computational approaches can be applied for the simulation of horizontal slug flows: - 'frozen slug' in a domain with moving wall boundaries, where the absolute value of the prescribed wall velocity is equal to the slug propagation velocity in the pipe. The slug propagation velocity and the slug length/period has to be known in advance. - Transient 3-D simulation in a short computational domain with periodic boundary conditions. A driving pressure force has to be prescribed to compensate the kinetic energy losses due to wall friction. Furthermore it has to be ensured, that the geometrical dimensions of the computational domain do not affect the computed slug flow length and time scales. - Transient 3. simulation of slug flow in a long pipe segment with inlet/outlet boundary conditions. The later of the three computational approaches provides the highest predictive capability, also it is the most computational intensive approach. The presented paper will discuss the general aspects of feasibility

  15. Carbon budgets for three autotrophic Australian estuaries: Implications for global estimates of the coastal air-water CO2 flux

    Science.gov (United States)

    Maher, D. T.; Eyre, B. D.

    2012-03-01

    Estuaries are `hot spots' in the global carbon cycle, yet data on carbon dynamics, in particular air-sea CO2 fluxes, from autotrophic systems are rare. Estuarine carbon budgets were constructed for three geomorphically distinct warm temperate Australian estuaries over an annual cycle. All three estuaries were net autotrophic, with annual net ecosystem metabolism (NEM) ranging from 8 ± 13.4 molC m-2 yr-1 to 10 ± 14 molC m-2 yr-1. There was a net flux of CO2 from the atmosphere to the estuaries of between 0.4 ± 0.6 molC m-2 yr-1 and 2 ± 0.9 molC m-2 yr-1. Loading of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) to the estuaries varied markedly within and between the estuaries, and was directly related to freshwater inflow. While NEM was similar in all three estuaries, the ratio of benthic versus pelagic contributions to NEM differed, with NEM dominated by pelagic production in the river dominated system, benthic production dominating in the intermediate estuary, and equal contributions of benthic and pelagic production in the marine dominated lagoon. All three estuaries exported more organic carbon than was imported, fueled by additional organic carbon supplied by NEM. The estuaries essentially acted as bioreactors, transforming DIC to organic carbon. Burial of organic carbon ranged from 1.2 ± 0.3 molC m-2 yr-1 to 4.4 ± 1.2 molC m-2 yr-1 and represented up to half of NEM. The annual net uptake of atmospheric CO2 in these systems, along with previous estimates of the global estuarine CO2flux being based predominantly on heterotrophic, large river dominated estuarine systems, indicates that the global estimate of the estuarine air-water CO2flux may be over-estimated due to the lack of studies from autotrophic marine dominated estuaries.

  16. Quantitative measurement of size and three-dimensional position of fast-moving bubbles in air-water mixture flows using digital holography.

    Science.gov (United States)

    Tian, Lei; Loomis, Nick; Domínguez-Caballero, José A; Barbastathis, George

    2010-03-20

    We present a digital in-line holographic imaging system for measuring the size and three-dimensional position of fast-moving bubbles in air-water mixture flows. The captured holograms are numerically processed by performing a two-dimensional projection followed by local depth estimation to quickly and efficiently obtain the size and position information of multiple bubbles simultaneously. Statistical analysis on measured bubble size distributions shows that they follow lognormal or gamma distributions.

  17. Air-water CO2 outgassing in the Lower Lakes (Alexandrina and Albert, Australia) following a millennium drought.

    Science.gov (United States)

    Li, Siyue; Bush, Richard T; Ward, Nicholas J; Sullivan, Leigh A; Dong, Fangyong

    2016-01-15

    Lakes are an important source and sink of atmospheric CO2, and thus are a vital component of the global carbon cycle. However, with scarce data on potentially important subtropical and tropical areas for whole continents such as Australia, the magnitude of large-scale lake CO2 emissions is unclear. This study presents spatiotemporal changes of dissolved inorganic carbon and water - to - air interface CO2 flux in the two of Australia's largest connected, yet geomorphically different freshwater lakes (Lake Alexandrina and Lake Albert, South Australia), during drought (2007 to September-2010) and post-drought (October 2010 to 2013). Lake levels in the extreme drought were on average approximately 1m lower than long-term average (0.71 m AHD). Drought was associated with an increase in the concentrations of dissolved inorganic species, organic carbon, nitrogen, Chl-a and major ions, as well as water acidification as a consequence of acid sulfate soil (ASS) exposure, and hence, had profound effects on lake pCO2 concentrations. Lakes Alexandrina and Albert were a source of CO2 to the atmosphere during the drought period, with efflux ranging from 0.3 to 7.0 mmol/m(2)/d. The lake air-water CO2 flux was negative in the post-drought, ranging between -16.4 and 0.9 mmol/m(2)/d. The average annual CO2 emission was estimated at 615.5×10(6) mol CO2/y during the drought period. These calculated emission rates are in the lower range for lakes, despite the potential for drought conditions that shift the lakes from sink to net source for atmospheric CO2. These observations have significant implications in the context of predicted increasing frequency and intensity of drought as a result of climate change. Further information on the spatial and temporal variability in CO2 flux from Australian lakes is urgently warranted to revise the global carbon budget for lakes. PMID:26520269

  18. Intraday evaporation and heat fluxes variation at air-water interface of extremely shallow lakes in Chilean Andean Plateau

    Science.gov (United States)

    Vergara, Jaime; de la Fuente, Alberto

    2016-04-01

    Salars are landscapes formed by evapo-concentration of salts that usually have extremely shallow terminal lagoons (de la Fuente & Niño, 2010). They are located in the altiplanic region of the Andes Mountains of Chile, Argentina, Bolivia and Peru, and they sustain highly vulnerable and isolated ecosystems in the Andean Desert. These ecosystems are sustained by benthic primary production, which is directly linked to mass, heat and momentum transfer between the water column and the atmosphere (de la Fuente, 2014). Despite the importance of these transport processes across the air-water interface, there are few studies describing their intraday variation and how they are influenced by the stability of the atmospheric boundary layer in the altiplano. The main objective of this work is to analyze the intraday vertical transport variation of water vapor, temperature and momentum between the atmosphere and a shallow water body on Salar del Huasco located in northern Chile (20°19'40"S, 68°51'25"W). To achieve this goal, we measured atmospheric and water variables in a campaign realized on late October 2015, using high frequency meteorological instruments (a sonic anemometer with an incorporated infrared gas analyzer, and a standard meteorological station) and water sensors. From these data, we characterize the intraday variation of water vapor, temperature and momentum fluxes, we quantify the influence of the atmospheric boundary layer stability on them, and we estimate transfer coefficients associated to latent heat, sensible heat, hydrodynamic drag and vertical transport of water vapor. As first results, we found that latent and sensible heat fluxes are highly influenced by wind speed rather buoyancy, and we can identify four intraday intervals with different thermo-hydrodynamic features: (1) cooling under stable condition with wind speed near 0 from midnight until sunrise; (2) free convection with nearly no wind speed under unstable condition from sunrise until midday

  19. Measurement of air distribution and void fraction of an upwards air-water flow using electrical resistance tomography and a wire-mesh sensor

    Science.gov (United States)

    Olerni, Claudio; Jia, Jiabin; Wang, Mi

    2013-03-01

    Measurements on an upwards air-water flow are reported that were obtained simultaneously with a dual-plane electrical resistance tomograph (ERT) and a wire-mesh sensor (WMS). The ultimate measurement target of both ERT and WMS is the same, the electrical conductivity of the medium. The ERT is a non-intrusive device whereas the WMS requires a net of wires that physically crosses the flow. This paper presents comparisons between the results obtained simultaneously from the ERT and the WMS for evaluation and calibration of the ERT. The length of the vertical testing pipeline section is 3 m with an internal diameter of 50 mm. Two distinct sets of air-water flow rate scenarios, bubble and slug regimes, were produced in the experiments. The fast impedance camera ERT recorded the data at an approximate time resolution of 896 frames per second (fps) per plane in contrast with the 1024 fps of the wire-mesh sensor WMS200. The set-up of the experiment was based on well established knowledge of air-water upwards flow, particularly the specific flow regimes and wall peak effects. The local air void fraction profiles and the overall air void fraction were produced from two systems to establish consistency for comparison of the data accuracy. Conventional bulk flow measurements in air mass and electromagnetic flow metering, as well as pressure and temperature, were employed, which brought the necessary calibration to the flow measurements. The results show that the profiles generated from the two systems have a certain level of inconsistency, particularly in a wall peak and a core peak from the ERT and WMS respectively, whereas the two tomography instruments achieve good agreement on the overall air void fraction for bubble flow. For slug flow, when the void fraction is over 30%, the ERT underestimates the void fraction, but a linear relation between ERT and WMS is still observed.

  20. Micrometeorological measurement of hexachlorobenzene and polychlorinated biphenyl compound air-water gas exchange in Lake Superior and comparison to model predictions

    Directory of Open Access Journals (Sweden)

    M. D. Rowe

    2012-01-01

    Full Text Available Air-water exchange fluxes of persistent, bioaccumulative and toxic (PBT substances are frequently estimated using the Whitman two-film (W2F method, but micrometeorological flux measurements of these compounds over water are rarely attempted. We measured air-water exchange fluxes of hexachlorobenzene (HCB and polychlorinated biphenyls (PCBs on 14 July 2006 in Lake Superior using the modified Bowen ratio (MBR method. Measured fluxes were compared to estimates using the W2F method, and to estimates from an Internal Boundary Layer Transport and Exchange (IBLTE model that implements the NOAA COARE bulk flux algorithm and gas transfer model. We reveal an inaccuracy in the estimate of water vapor transfer velocity that is commonly used with the W2F method for PBT flux estimation, and demonstrate the effect of use of an improved estimation method. Flux measurements were conducted at three stations with increasing fetch in offshore flow (15, 30, and 60 km in southeastern Lake Superior. This sampling strategy enabled comparison of measured and predicted flux, as well as modification in near-surface atmospheric concentration with fetch, using the IBLTE model. Fluxes estimated using the W2F model were compared to fluxes measured by MBR. In five of seven cases in which the MBR flux was significantly greater than zero, concentration increased with fetch at 1-m height, which is qualitatively consistent with the measured volatilization flux. As far as we are aware, these are the first reported micrometeorological air-water exchange flux measurements of PCBs.

  1. Micrometeorological measurement of hexachlorobenzene and polychlorinated biphenyl compound air-water gas exchange in Lake Superior and comparison to model predictions

    Directory of Open Access Journals (Sweden)

    M. D. Rowe

    2012-05-01

    Full Text Available Air-water exchange fluxes of persistent, bioaccumulative and toxic (PBT substances are frequently estimated using the Whitman two-film (W2F method, but micrometeorological flux measurements of these compounds over water are rarely attempted. We measured air-water exchange fluxes of hexachlorobenzene (HCB and polychlorinated biphenyls (PCBs on 14 July 2006 in Lake Superior using the modified Bowen ratio (MBR method. Measured fluxes were compared to estimates using the W2F method, and to estimates from an Internal Boundary Layer Transport and Exchange (IBLTE model that implements the NOAA COARE bulk flux algorithm and gas transfer model. We reveal an inaccuracy in the estimate of water vapor transfer velocity that is commonly used with the W2F method for PBT flux estimation, and demonstrate the effect of use of an improved estimation method. Flux measurements were conducted at three stations with increasing fetch in offshore flow (15, 30, and 60 km in southeastern Lake Superior. This sampling strategy enabled comparison of measured and predicted flux, as well as modification in near-surface atmospheric concentration with fetch, using the IBLTE model. Fluxes estimated using the W2F model were compared to fluxes measured by MBR. In five of seven cases in which the MBR flux was significantly greater than zero, concentration increased with fetch at 1-m height, which is qualitatively consistent with the measured volatilization flux. As far as we are aware, these are the first reported ship-based micrometeorological air-water exchange flux measurements of PCBs.

  2. Savinase action on bovine serum albumin (BSA) monolayers demonstrated with measurements at the air-water interface and liquid Atomic Force Microscopy (AFM) imaging

    DEFF Research Database (Denmark)

    Balashev, Konstantin; Callisen, Thomas H; Svendsen, Allan;

    2011-01-01

    We studied the enzymatic action of Savinase on bovine serum albumin (BSA) organized in a monolayer spread at the air/water interface or adsorbed at the mica surface. We carried out two types of experiments. In the first one we followed the degradation of the protein monolayer by measuring...... the surface pressure and surface area decrease versus time. In the second approach we applied AFM imaging of the supported BSA monolayers adsorbed on mica solid supports and extracted information for the enzyme action by analyzing the obtained images of the surface topography in the course of enzyme action...

  3. 气水比对曝气生物滤池SND的影响%Influence of air/water ratio on the performance of SND in BAF

    Institute of Scientific and Technical Information of China (English)

    杨长生

    2011-01-01

    The two-stage BAF process for treating municipal sewage, and the influence of air/water ratio on the treatment effectiveness of the reactors have been investigated. When the hydraulic loading for stage A is 0.81 m/h and air/ water ratio 3:1, the operational state of the reactor is analyzed when the air/water ratio for stage B is 3∶1,2∶1 and 1∶1, respectively. The results show that the reactor in stage A basically has no removal effect on TN, because the partial oxidation of NH/-N makes the mass concentration of NO2--N in the effluent range from 0.45 to 0.70 mg/L and that of NO3--N range from 26.09 mg/L to 41.04 mg/L. When the air/water ratio for stage B is 2∶1 ,the removal efficiency of TN is the best. The average removal rate is 50.02%. The content of nitrate achieves the minimum.%采用两段BAF处理城市污水,探讨了气水比对反应器处理效果的影响.在A段水力负荷为0.81 m/h、气水比为3∶1时,分析了B段气水比分别为3∶1、2∶1和1∶1时反应器的运行情况.结果表明:A段反应器对TN基本上没有去除效果,因NH4+ -N的部分氧化使得出水中NO2--N质量浓度介于0.45~0.70 mg/L之间,NO3- -N质量浓度则介于26.09~41.04 mg/L;B段反应器气水比为2∶1时,TN的去除效果最好,平均去除率为50.02%,出水中硝酸盐含量达到最小值.

  4. Time-resolved fast-neutron radiography of air-water two-phase flows in a rectangular channel by an improved detection system

    OpenAIRE

    Zboray, Robert; Dangendorf, Volker; Mor, Ilan; Bromberger, Benjamin; Tittelmeier, Kai

    2015-01-01

    In a previous work we have demonstrated the feasibility of high-frame-rate, fast-neutron radiography of generic air-water two-phase flows in a 1.5 cm thick, rectangular flow channel. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany, using an multi-frame, time-resolved detector developed for fast neutron resonance radiography. The results were however not fully optimal and therefore we have decided to modify ...

  5. Effects of outlet blade angle of centrifugal pump on the pump performance under air-water two-phase flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Minemura, Kiyoshi; Kinoshita, Katsuhiko [Nagoya Univ. (Japan). School of Informatics and Sciences; Ihara, Masaru; Furukawa, Hironori; Egashira, Kazuyuki [Japan National Oil Corp., Chiba (Japan). Petroleum Engineering Lab.

    1995-12-31

    To establish the optimum design parameters of offshore oil well centrifugal pumps, which should deliver crude oil containing a large amount of gas, various shapes of pump impeller with different outlet blade angles, locations of leading-edge and numbers of impeller blades as the design parameters were tested with various rotating speeds and suction pressures under air-water two-phase flow conditions. The greater the outlet blade angle, the less the degradation of the pump performance becomes, showing the optimum blade angle approximately equals to 90{degree}.

  6. Molecular assemblies of 4-(hexadecyloxy)-n-(pyridinylmethylene)anilines at the air-water interface and Cu(II)-promoted vesicle formation via metal coordination.

    Science.gov (United States)

    Wang, Haibo; Miao, Wangen; Liu, Huijin; Zhang, Xianfeng; Du, Xuezhong

    2010-09-01

    The molecular assemblies of 4-(hexadecyloxy)-N-(pyridinylmethylene)anilines (HPA) at the air-water interface on pure water and aqueous Cu(II) subphases have been investigated using in situ infrared reflection absorption spectroscopy (IRRAS). The Schiff base units were oriented with their long axes almost perpendicular to the water surface, and both imine and pyridinyl nitrogen atoms of the Schiff base units were coordinated to Cu(II) ions together with their geometrical conversions. The alkyl chains in the monolayers were quantitatively determined on the assumption that the HPA monolayers at the air-water interface were composed of sublayers of alkyl chains and Schiff base units, and the chain orientation angle on pure water was 30 +/- 2 degrees and increased to 37 +/- 2 degrees on the aqueous Cu(II) subphase. The HPA amphiphiles could not be dispersed in pure water but could self-organize into vesicles with metal-coordinated headgroups and interdigitated-packed alkyl chains in the presence of Cu(II) ions in aqueous solution. Transmission electron microscopy (TEM), differential scanning calorimetry (DSC), UV-vis spectroscopy, and small-angle X-ray diffraction (XRD) were used to investigate the aggregate structures and specific properties of the coordinated vesicles. PMID:20698514

  7. Toward a unified picture of the water self-ions at the air-water interface: a density functional theory perspective.

    Science.gov (United States)

    Baer, Marcel D; Kuo, I-Feng W; Tobias, Douglas J; Mundy, Christopher J

    2014-07-17

    The propensities of the water self-ions, H3O(+) and OH(-), for the air-water interface have implications for interfacial acid-base chemistry. Despite numerous experimental and computational studies, no consensus has been reached on the question of whether or not H3O(+) and/or OH(-) prefer to be at the water surface or in the bulk. Here we report a molecular dynamics simulation study of the bulk vs interfacial behavior of H3O(+) and OH(-) that employs forces derived from density functional theory with a generalized gradient approximation exchange-correlation functional (specifically, BLYP) and empirical dispersion corrections. We computed the potential of mean force (PMF) for H3O(+) as a function of the position of the ion in the vicinity of an air-water interface. The PMF suggests that H3O(+) has equal propensity for the interface and the bulk. We compare the PMF for H3O(+) to our previously computed PMF for OH(-) adsorption, which contains a shallow minimum at the interface, and we explore how differences in solvation of each ion at the interface vs in the bulk are connected with interfacial propensity. We find that the solvation shell of H3O(+) is only slightly dependent on its position in the water slab, while OH(-) partially desolvates as it approaches the interface, and we examine how this difference in solvation behavior is manifested in the electronic structure and chemistry of the two ions. PMID:24762096

  8. Mechanical properties of protein adsorption layers at the air/water and oil/water interface: a comparison in light of the thermodynamical stability of proteins.

    Science.gov (United States)

    Mitropoulos, Varvara; Mütze, Annekathrin; Fischer, Peter

    2014-04-01

    Over the last decades numerous studies on the interfacial rheological response of protein adsorption layers have been published. The comparison of these studies and the retrieval of a common parameter to compare protein interfacial activity are hampered by the fact that different boundary conditions (e.g. physico-chemical, instrumental, interfacial) were used. In the present work we review previous studies and attempt a unifying approach for the comparison between bulk protein properties and their adsorption films. Among many common food grade proteins we chose bovine serum albumin, β-lactoglobulin and lysozyme for their difference in thermodynamic stability and studied their adsorption at the air/water and limonene/water interface. In order to achieve this we have i) systematically analyzed protein adsorption kinetics in terms of surface pressure rise using a drop profile analysis tensiometer and ii) we addressed the interfacial layer properties under shear stress using an interfacial shear rheometer under the same experimental conditions. We could show that thermodynamically less stable proteins adsorb generally faster and yield films with higher shear rheological properties at air/water interface. The same proteins showed an analog behavior when adsorbing at the limonene/water interface but at slower rates. PMID:24332621

  9. How does spacer length of imidazolium gemini surfactants control the fabrication of 2D-Langmuir films of silver-nanoparticles at the air-water interface?

    Science.gov (United States)

    Datta, Sougata; Biswas, Joydeep; Bhattacharya, Santanu

    2014-09-15

    A series of gemini surfactants based on cationic imidazolium ring as polar headgroup, abbreviated as [Im-n-Im], 2Br(-) (n=2, 5, 6 and 12), was synthesized. Their ability to stabilize silver nanoparticles in aqueous media was investigated. The resulting suspensions were characterized by UV-Vis spectroscopy and transmission electron microscopy (TEM). They exhibit specific morphologies by adopting different supramolecular assemblies in aqueous media depending on the internal packing arrangements and on the number of spacer methylene units [-(CH2)n-]. Individual colloids were extracted from the aqueous to chloroform layer and spread at the air/water interface to allow the formation of well-defined Langmuir films. By analysis of the surface pressure-area isotherms, the details about the packing behavior and orientation of the imidazolium gemini surfactant capped silver nanoparticles were obtained. Morphological features of the dynamic process of monolayer compression at the air-water interface were elucidated using Brewster angle microscopy (BAM). These monolayers were further transferred on mica sheets by the Langmuir-Blodgett technique at their associated collapse pressure and the morphology of these monolayers was investigated by atomic force microscopy (AFM). The number of spacer methylene units [-(CH2)n-] of the gemini surfactants exerted critical influence in modulating the characteristics of the resulting Langmuir films. PMID:24998058

  10. Controlling the assembly of hydrophobized gold nanoparticles at the air-water interface by varying the interfacial tension

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Shweta; Singh, Nahar [Material Characterization Division, National Physical Laboratory, New Delhi-110012 (India); Sastry, Murali [Tata Chemical Innovation Center, Anmol Pride, Baner Road, Pune-45 (India); Kakkar, Rita [Department of Chemistry, Delhi University, Delhi-110007 (India); Pasricha, Renu, E-mail: pasrichar@mail.nplindia.ernet.i [Material Characterization Division, National Physical Laboratory, New Delhi-110012 (India)

    2010-11-30

    Controlled assembly is the key to harness the nanoscale properties of nanoparticles in most technological applications and it has been an important challenge as it leads to the manipulation of interparticle properties. The present work depicts the control of the assembly of nanoparticles in the monolayers by evaporation kinetics and particle interactions at the air-liquid interface. In the presence of attractive particle-particle and particle-monolayers interactions, nanoparticles self assemble into a superlattice structure upon drying from a colloidal suspension on to the preformed lipid monolayers. This self-assembly mechanism produces monolayers with long-range ordering. However, rapid dewetting and high rate of evaporation can significantly undermine the extent of ordering. Using gold nanoparticles as vehicles for experimentation and by changing the monolayers and solvent, we here demonstrate that the extent of ordering of nanoparticles can be controlled.

  11. Three-dimensional calculation of air-water two-phase flow in a centrifugal pump based on a bubbly flow model with fixed cavity

    International Nuclear Information System (INIS)

    To predict the behavior of air-water two-phase flows in centrifugal pumps, we have proposed a three-dimensional numerical method on the basis of an inviscid bubbly flow model with slippage between two phases. The void fractions calculated distribute unevenly and their maximum exceeds an applicability of the model. To extend its applicability, a newly modified model is proposed in this paper by assuming that the bubbles in such high void fraction regions coalesce with each other and adhere to the neighboring impeller walls so as to form a fixed cavity. Using this model, the flows in a radial-flow pump are solved. The cavity obtained increases progressively from the shroud to the hub in the section just after the impeller inlet when the inlet void fraction exceeds a critical value and finally fills the section, showing close relation with the experiments when the pump loses its function due to an air-filled blockade. (author)

  12. An in-situ Observation on Initial Aggregation Process of Colloidal Particles near Three-Phase Contact Line of Air, Water and Vertical Substrate

    Institute of Scientific and Technical Information of China (English)

    YAO Can; WANG Yu-Ren; LAN Ding; DUAN Li; KANG Qi

    2008-01-01

    The self-assembling process near the three-phase contact line of air, water and vertical substrate is widely used to produce various kinds of nanostructured materials and devices. We perform an in-situ observation on the selfassembling process in the vicinity of the three phase contact line. Three kinds of aggregations, i.e. particle-particle aggregation, particle-chain aggregation and chain-chain aggregation, in the initial stage of vertical deposition process are revealed by our experiments. It is found that the particle-particle aggregation and the particle-chain aggregation can be qualitatively explained by the theory of the capillary immersion force and mirror image force,while the chain-chain aggregation leaves an opening question for the further studies. The present study may provide more deep insight into the self-assembling process of colloidal particles.

  13. Project Increase of infrastructure: 'Establishment of a laboratory for studies of pollutants in air, water and soil through atomic and nuclear techniques

    International Nuclear Information System (INIS)

    In this report there are the guidelines of this project as well as the goals, activities and costs. The general objectives were: 1. A laboratory that allows to analyze with efficiency samples of air, water and soil pollutants using atomic and nuclear origin techniques as PIXE (Proton Induced X-ray Emission, NRA (Nuclear Reaction Analysis) and RBS (Rutherford Backscattering) as well as auxiliary and/or complementary techniques. 2. To obtain indicators of the influence of the pollution of the Valley of Mexico about the ecology and the health of the inhabitants of Mexico City with perspectives of carrying out studies in other cities. 3. To develop an appropriate technology for the realization of those studies and to generate human resources in this area. (Author)

  14. Three-dimensional calculation of air-water two-phase flow in centrifugal pump impeller based on a bubbly flow model, 1

    International Nuclear Information System (INIS)

    To predict the behavior of air-water two-phase flows in a centrifugal pump impeller, a three-dimensional numerical method is proposed based on a bubbly flow model. If it is assumed that the mixtures are homogeneous bubbly flow containing fine bubbles compared with the characteristic length of the impeller channel, then the equations of motion of the mixtures are represented by those of liquid phase and its velocity is expressed as a potential for the quasi-harmonic equation. The equations are solved by use of the finite element method to obtain the velocities and pressures, and the equation of motion of an air bubble is integrated numerically on this flow field to obtain the void fraction. These calculations are repeated until the solutions converge. The results obtained show good agreement with experiments within the range of bubbly flow regime. (author)

  15. TOPFLOW-PTS air-water experiments on the phase separation in the ECC nozzle and the ECC water mixing during PTS scenarios

    International Nuclear Information System (INIS)

    In two-phase Pressurized Thermal Shock scenarios several thermal hydraulic phenomena, such as direct contact condensation, entrainment of steam bubbles and multi-scale momentum transfer are involved. The TOPFLOW-PTS experimental assembly represents a 1:2.5 scaled model of a PWR downcomer, cold leg with emergency core cooling injection and a pump simulator. It is build up for the development and validation of CFD models. The setup is highly instrumented - a large number of thermocouples, an infrared and a high-speed camera as well as wire mesh sensors are used to obtain CFD-grade data. As a first step air-water experiments were done with the special aim to investigate the behaviour of the liquid jet from the ECC injection into the cold leg. They indicated that the jet momentum at the impact position is very important for the mixing process and stratification inside the ECC nozzle needs to be considered in CFD calculations. (author)

  16. Two-photon excitation of surface plasmon and the period-increasing effect of low spatial frequency ripples on a GaP crystal in air/water

    Science.gov (United States)

    Liu, Jukun; Jia, Tianqing; Zhao, Hongwei; Huang, Yaoqing

    2016-11-01

    We report the period-increasing effect of low spatial frequency ripples on a GaP crystal irradiated by 1 kHz, 50 fs, 800 nm femtosecond laser pulses. Massive free electrons are excited by a two-photon absorption process and surface plasmon is excited. The Drude model is used to estimate the changing of the dielectric constant of the GaP crystal. The period-increasing effects of low spatial frequency laser-induced ripples are theoretically predicted in air/water, and the experimental results agree well. The experimental and theoretical results indicate that surface plasmon excited by two-photon absorption plays a key role in the formation of low spatial frequency ripples.

  17. Experimental results of UPTF TEST 21-D counter-part air/water test for the validation of modified linear scaling methodology

    International Nuclear Information System (INIS)

    From the two dimensional two-fluid model a new scaling methodology, named the 'modified linear scaling', is suggested for the scientific design of a scaled-down experimental facility and data analysis of the direct ECC bypass under LBLOCA reflood phase. The characteristics of the scaling law are its velocity is scaled by a Wallis-type parameter and the aspect ratio of experimental facility is preserved with that of prototype. For the experimental validation of the proposed scaling law, the air-water tests for direct ECC bypass were performed in the 1/4.0 and 1/7.3 scaled UPTF downcomer test section. The obtained data are compared with those of UPTF Test21-D. It is found that the modified linear scaling methodology is appropriate for the preservation of multi-dimensional flow phenomena in downcomer annulus, such as direct ECC bypass

  18. In situ air-water and particle-water partitioning of perfluorocarboxylic acids, perfluorosulfonic acids and perfluorooctyl sulfonamide at a wastewater treatment plant.

    Science.gov (United States)

    Vierke, Lena; Ahrens, Lutz; Shoeib, Mahiba; Palm, Wolf-Ulrich; Webster, Eva M; Ellis, David A; Ebinghaus, Ralf; Harner, Tom

    2013-08-01

    In situ measurements of air and water phases at a wastewater treatment plant (WWTP) were used to investigate the partitioning behavior of perfluorocarboxylic acids (PFCAs), perfluorosulfonic acids (PFSAs) and perfluorooctyl sulfonamide (HFOSA) and their conjugate bases (PFC(-)s, PFS(-)s, and FOSA(-), respectively). Particle-dissolved (Rd) and air-water (QAW) concentration ratios were determined at different tanks of a WWTP. Sum of concentrations of C4-12,14 PFC(A)s, C4,6,8,10 PFS(A)s and (H)FOSA were as high as 50 pg m(-3) (atmospheric gas phase), 2300 ng L(-1) (aqueous dissolved phase) and 2500 ng L(-1) (aqueous particle phase). Particle-dissolved concentration ratios of total species, log Rd, ranged from -2.9 to 1.3 for PFS(A)s, from -1.9 to 1.1 for PFC(A)s and was 0.71 for (H)FOSA. These field-based values agree well with equilibrium partitioning data reported in the literature, suggesting that any in situ generation from precursors, if they are present in this system, occurs at a slower rate than the rate of approach to equilibrium. Acid QAW were also estimated. Good agreement between the QAW and the air-water equilibrium partition coefficient for C8PFCA suggests that the air above the WWTP tanks is at or near equilibrium with the water. Uncertainties in these QAW values are attributed mainly to variability in pKa values reported in the literature. The WWTP provides a unique environment for investigating environmental fate processes of the PFCAs and PFSAs under 'real' conditions in order to better understand and predict their fate in the environment.

  19. Visualization of an adsorption model for surfactant transport from micelle solutions to a clean air/water interface using fluorescence microscopy.

    Science.gov (United States)

    Song, Qing; Yuan, Mingjun

    2011-05-01

    This work pertains to visualizing a transport model for adsorption of surfactants from micelle solutions onto a clean air/water interface. Under the condition of surfactant adsorption from very dilute solutions, the time scale for diffusion of a surfactant monomer is much slower than the time scale for kinetic breakdown of the aggregates. A theoretical model predicts two regimes for the adsorption dynamics. We visualize these two regimes under the mechanism of solubilization using fluorescence microscopy, in which an insoluble fluorescent probe, NBD-HAD (4-(hexadecylamino)-7-nitrobenz-2-oxa-1,3-diazole), is used to illuminate the micelles. The dye fluoresces in the microenvironment of micelles but is quenched in the aqueous solution on laser excitation. The region containing micelles is illuminated, but the region which does not contain micelles appears dark. For surfactant solution of C(14)E(6) at concentration just above the critical micelle concentration (C(CMC)), C(CMC)=4.4 mg/L, a dark region between the bright image of the air/water interface and the micelle-containing zone is observed. This dark region becomes smaller with time and finally disappears once equilibrium is reached. For a surfactant solution of C(14)E(6) at the concentration of 4.74C(CMC), which is higher than a critical total surfactant concentration (C(T)(c)) of 4.25C(CMC), we observe bright images through surfactant solutions during the adsorption process. Fluorescence images validate the theoretical model. PMID:21349535

  20. Reorientation of the ‘free OH’ group in the top-most layer of air/water interface of sodium fluoride aqueous solution probed with sum-frequency generation vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Ran-Ran; Guo, Yuan; Wang, Hongfei

    2014-09-17

    Many experimental and theoretical studies have established the specific anion, as well as cation effects on the hydrogen-bond structures at the air/water interface of electrolyte solutions. However, the ion effects on the top-most layer of the air/water interface, which is signified by the non-hydrogen-bonded so-called ‘free O-H’ group, has not been discussed or studied. In this report, we present the measurement of changes of the orientational angle of the ‘free O-H’ group at the air/water interface of the sodium fluoride (NaF) solutions at different concentrations using the interface selective sum-frequency generation vibrational spectroscopy (SFG-VS) in the ssp and ppp polarizations. The polarization dependent SFG-VS results show that the average tilt angle of the ‘free O-H’ changes from about 35.3 degrees ± 0.5 degrees to 43.4 degrees ± 2.1degrees as the NaF concentration increase from 0 to 0.94M (nearly saturated). Such tilt angle change is around the axis of the other O-H group of the same water molecule at the top-most layer at the air/water interface that is hydrogen-bonded to the water molecules below the top-most layer. These results provide quantitative molecular details of the ion effects of the NaF salt on the structure of the water molecules at the top-most layer of the air/water interfacial, even though both the Na+ cation and the F- anion are believed to be among the most excluded ions from the air/water interface.

  1. Point-spread function associated with underwater imaging through a wavy air-water interface: theory and laboratory tank experiment.

    Science.gov (United States)

    Brown, W C; Majumdar, A K

    1992-12-20

    The point-spread function needed for imaging underwater objects is theoretically derived and compared with experimental results. The theoretical development is based on the emergent-ray model, in which the Gram-Charlier series for the non-Gaussian probability-density function for emergent angles through a wavy water surface was assumed. To arrive at the point-spread model, we used a finite-element methodology with emergent-ray angular probability distributions as fundamental building functions. The model is in good agreement with the experiment for downwind conditions. A slight deviation between theory and experiment was observed for the crosswind case; this deviation may be caused by the possible interaction of standing waves with the original air-ruffled capillary waves that were not taken into account in the model.

  2. 3种芦丁脂肪酸酯在空气/水界面的成膜性质%Monolayers of Three Amphiphilic Esters of Rutin at the Air-water Interface

    Institute of Scientific and Technical Information of China (English)

    段煜; 杜宗良; 李瑞霞; 吴大诚

    2011-01-01

    The π - A isotherms for monolayers of three amphiphilic rutin esters, rutin - 4''' - 0 - stearate ( RS ), rutin - 4''' - 0 -laurate (RL) and rutin -4''' -0 -caproate (RC), were measured at the air-water interface and air-aqueous aluminum sulfate solution interface.The properties of the monolayers of three rutin esters were related to the carbon number of alkyl, the compression rate and the property of substrate.Although RS and RL showed scant water solubility, they formed monolayers with the liquid-expanded phase when spread on water.While RC could not form insoluble monolayer at the air-water interface, which may be due to the larger water solubility of RC.Appropriately low compression rate was critical to the formation of relatively stable monolayers.When spread on an aqueous aluminum sulfate solution, the formation of a complex between the aluminum ions and the rutin ester resulted in higher values of acoll for RS and RL monolayers compared with their values on water, and RC could spread as liquid-expanded phase monolayer.The present results provided valuable information for investigating the interaction of flavonoids and biomembranes and the anti-oxidant mechanism of flavonoids.%采用LB膜分析仪分别研究了芦丁硬脂酸酯(RS)、芦丁月桂酸酯(RL)和芦丁正己酸酯(RC)在空气/水界面的成膜性质,及亚相中的Al3+对3种芦丁脂肪酸酯成膜性质的影响.结果显示,3种芦丁脂肪酸酯的成膜性质与其疏水基的碳链长度、压膜速度和亚相性质有关.RS和RL能在水面铺展为液态扩张膜,RC则不能成膜.引入芦丁分子中的疏水基碳链越长,成膜越稳定.慢速压膜利于膜稳定性,膜的崩溃压大;较快速压膜能使更多膜分子保留在水表面,膜的平均分子面积大.选择适宜的压膜速度对得到比较稳定的芦丁脂肪酸酯膜很关键.当亚相中含Al3+时,RS、RL和RC均铺展成液态扩张膜,且RS膜和RL膜崩溃时的分子面积(acoll)大于它们在水表

  3. Effects of the conjugation of whey proteins with gellan polysaccharides on surfactant-induced competitive displacement from the air-water interface.

    Science.gov (United States)

    Cai, B; Ikeda, S

    2016-08-01

    Whey proteins can be used to stabilize foams and emulsions against coalescence because of their ability to form viscoelastic films at the interface that resist film rupture on collision between colloidal particles. However, whey proteins are competitively displaced from the interface if small-molecule surfactants are added, leading to destabilization of the entire system. This is because surfactants are more effective in molecular packing at the interface, and they lower interfacial tension to a greater degree than whey proteins do, but their interfacial films are poor in viscoelasticity. We hypothesized that whey proteins would become more resistant to surfactant-induced competitive displacement if they were conjugated with network-forming polysaccharides. The protein moiety of the conjugate would be expected to enable its adsorption to the interface, and the polysaccharide moiety would be expected to form self-assembled networks, strengthening the interfacial film as a whole. In this study, whey proteins were conjugated with gellan polysaccharides using the Maillard reaction. Atomic force microscopy images of interfacial films formed by the whey protein-gellan conjugate at the air-water interface and transferred onto mica sheets using the Langmuir-Blodgett method revealed that gellan did form self-assembled networks at the interface and that interfacial films also contained a large number of unconjugated whey protein molecules. Following the addition of a small-molecule surfactant (Tween 20) to the sub-phase, surface pressure increased, indicating spontaneous adsorption of surfactants to the interface. Atomic force microscopy images showed decreases in interfacial area coverage by whey proteins as surface pressure increased. At a given surface pressure, the interfacial area coverage by whey protein-gellan conjugates was greater than coverage by unconjugated whey proteins, confirming that whey proteins became more resistant to surfactant-induced displacement after

  4. Monolayers of gemini surfactants and their catanionic mixtures with sodium dodecyl sulfate at the air-water interface: Chain length and composition effects

    International Nuclear Information System (INIS)

    Monolayers of cationic gemini surfactants and their catanionic mixtures with sodium dodecyl sulfate (SDS), have been investigated with the Langmuir trough technique, at the air-water interface. The gemini surfactants are of the alkanediyl-α,ω-bis(alkyldimethylammonium) type, here designated as m-2-m, where m and 2 are the alkyl chain and spacer lengths, respectively. For the neat geminis, the stability of the monolayer increases as the chain length increases, starting from soluble films of 12-2-12 to stable films of 18-2-18. For the equicharged m-2-m/SDS mixtures (with m = 12, 14, 16 and 18), stable monolayers are obtained. The effect of the gemini chain length on the phase behavior and molecular organization of the films is discussed on the basis of pressure-area isotherms for compression or compression-expansion cycles. The pressure-temperature plots, at constant trough area, yield the desorption temperature and suggest the desorption mechanism of the film molecules. Furthermore, the effect of the mixing molar ratio between m-2-m and SDS on the isotherms, for m = 12 and 14, has also been investigated. It is concluded from the mean area per molecule that the gemini molecules when in excess with respect to equicharged composition desorb from the film, so that the electroneutral composition is maintained

  5. Miscibility of dl-α-tocopherol β-glucoside in DPPC monolayer at air/water and air/solid interfaces.

    Science.gov (United States)

    Neunert, G; Makowiecki, J; Piosik, E; Hertmanowski, R; Polewski, K; Martynski, T

    2016-10-01

    The role of newly synthesized tocopherol glycosidic derivative in modifying molecular organization and phase transitions of phospholipid monolayer at the air/water interface has been investigated. Two-component Langmuir films of dl-α-tocopheryl β-D-glucopyranoside (BG) mixed with dipalmitoyl phosphatidylcholine (DPPC) in the whole range of mole fractions were formed at the water surface. An analysis of surface pressure versus mean molecular area (π-A) isotherms and Brewster angle microscope images showed that the presence of BG molecules changes the structure and packing of the DPPC monolayer in a BG concentration dependent manner. BG molecules incorporated into DPPC monolayer inhibit its liquid expanded to liquid condensed phase transition proportionally to the BG concentration. The monolayers were also transferred onto solid substrates and visualized using an atomic force microscope. The results obtained indicate almost complete miscibility of BG and DPPC in the monolayers at surface pressures present in the biological cell membrane (30-35·10(-3) N·m(-1)) for a BG mole fraction as high as 0.3. This makes the monolayer less packed and more disordered, leading to an increased permeability. The results support our previous molecular dynamics simulation data. PMID:27287132

  6. Numerical analysis for two-dimensional compressible and two-phase flow fields of air-water in Eulerian grid framework

    International Nuclear Information System (INIS)

    Two-phase compressible flow fields of air-water are investigated numerically in the fixed Eulerian grid framework. The phase interface is captured via volume fractions of ech phase. A way to model two phase compressible flows as a single phase one is found based on an equivalent equation of states of Tait's type for a multiphase cell. The equivalent single phase field is discretized using the Roe's approximate Riemann solver. Two approaches are tried to suppress the pressure oscillation phenomena at the phase interface, a passive advection of volume fraction and a direct pressure relaxation with the compressible form of volume fraction equation. The direct pressure equalizing method suppresses pressure oscillation successfully and generates sharp discontinuities, transmitting and reflecting acoustic waves naturally at the phase interface. In discretizing the compressible form of volume fraction equation, phase interfaces are geometrically reconstructed to minimize the numerical diffusion of volume fraction and relevant variables. The motion of a projectile in a water-filled tube which is fired by the release of highly pressurized air is simulated presuming the flow field as a two dimensional one, and several design factors affecting the projectile movement are investigated

  7. Binding structure and kinetics of surfactin monolayer formed at the air/water interface to counterions: A molecular dynamics simulation study.

    Science.gov (United States)

    Gang, Hongze; Liu, Jinfeng; Mu, Bozhong

    2015-10-01

    The binding structure and kinetics of ionized surfactin monolayer formed at the air/water interface to five counterions, Li+, Na+, K+, Ca2+, and Ba2+ (molar ratios of surfactin to monovalent and divalent counterions are 1:2 and 1:1 respectively), have been studied using molecular dynamics simulation. The results show that surfactin exhibits higher binding affinity to divalent counterions, Ca2+, and Ba2+, and smaller monovalent counterion, Li+, than Na+ and K+. Both carboxyl groups in surfactin are accessible for counterions, but the carboxyl group in Glu1 is easier to access by counterions than Asp5. Salt bridges are widely built between carboxyl groups by counterions, and the probability of the formation of intermolecular salt bridge is markedly larger than that of intramolecular salt bridge. Divalent counterions perform well in forming salt bridges between carboxyl groups. The salt bridges mediated by Ca2+ are so rigid that the lifetimes are about 0.13 ns, and the break rates of these salt bridges are 1-2 orders of magnitude smaller than those mediated by K+ which is about 5 ps in duration. The positions of the hydration layer of carboxyl groups are independent of counterions, but the bound counterions induce the dehydration of carboxyl groups and disturb the hydrogen bonds built between carboxyl group and hydration water.

  8. Combined effect of synthetic protein, Mini-B, and cholesterol on a model lung surfactant mixture at the air-water interface.

    Science.gov (United States)

    Chakraborty, Aishik; Hui, Erica; Waring, Alan J; Dhar, Prajnaparamita

    2016-04-01

    The overall goal of this work is to study the combined effects of Mini-B, a 34 residue synthetic analog of the lung surfactant protein SP-B, and cholesterol, a neutral lipid, on a model binary lipid mixture containing dipalmitolphosphatidylcholine (DPPC) and palmitoyl-oleoyl-phosphatidylglycerol (POPG), that is often used to mimic the primary phospholipid composition of lung surfactants. Using surface pressure vs. mean molecular area isotherms, fluorescence imaging and analysis of lipid domain size distributions; we report on changes in the structure, function and stability of the model lipid-protein films in the presence and absence of varying composition of cholesterol. Our results indicate that at low cholesterol concentrations, Mini-B can prevent cholesterol's tendency to lower the line tension between lipid domain boundaries, while maintaining Mini-B's ability to cause reversible collapse resulting in the formation of surface associated reservoirs. Our results also show that lowering the line tension between domains can adversely impact monolayer folding mechanisms. We propose that small amounts of cholesterol and synthetic protein Mini-B can together achieve the seemingly opposing requirements of efficient LS: fluid enough to flow at the air-water interface, while being rigid enough to oppose irreversible collapse at ultra-low surface tensions. PMID:26775740

  9. Noise abatement in air-water heat pump systems. Basic considerations, guidelines for practice; Laermreduktion bei Luft/Wasser-Waermepumpenanlagen. Grundlagen und Massnahmen

    Energy Technology Data Exchange (ETDEWEB)

    Graf, H.R.

    2002-07-01

    With increasing numbers of installations of air/water heat pumps the issue of noise emissions is becoming more of a concern. In reaction to this situation, the company Sulzer Innotec has developed these guidelines by order of the Swiss Federal Office of Energy. Typically, more than 90% of the noise emitted outdoors is produced by the fan. Due to the strong tonal components, the noise emitted is substantially more annoying than a reference broadband noise of the same intensity. For further noise reduction mainly the fan noise must be addressed. Despite the dominance of fan noise, other noise sources must not be neglected. The most promising countermeasures are: Reduction of fan noise by (i) low blade tip speed (prerequisite is a pressure drop in the air channels including the evaporator as low as possible), (ii) improvement of flow geometry in the vicinity of the fan, (iii) insulation of air ducts with acoustic foam (thickness 50 mm or more), (iv) elbows in the air duct line for sound dissipation. Reduction of compressor noise by (i) a highly effective acoustic enclosure, (ii) vibration insulation of structure-borne noise by elastic mounts, (iii) decoupling of refrigerant pipes. (author)

  10. Spatial trends, sources, and air-water exchange of organochlorine pesticides in the Great Lakes basin using low density polyethylene passive samplers.

    Science.gov (United States)

    Khairy, Mohammed; Muir, Derek; Teixeira, Camilla; Lohmann, Rainer

    2014-08-19

    Polyethylene passive samplers were deployed during summer and fall of 2011 in the lower Great Lakes to assess the spatial distribution and sources of gaseous and freely dissolved organochlorine pesticides (OCPs) and their air-water exchange. Average gaseous OCP concentrations ranged from nondetect to 133 pg/m(3). Gaseous concentrations of hexachlorobenzene, dieldrin, and chlordanes were significantly greater (Mann-Whitney test, p < 0.05) at Lake Erie than Lake Ontario. A multiple linear regression implied that both cropland and urban areas within 50 and 10 km buffer zones, respectively, were critical parameters to explain the total variability in atmospheric concentrations. Freely dissolved OCP concentrations (nondetect to 114 pg/L) were lower than previously reported. Aqueous half-lives generally ranged from 1.7 to 6.7 years. Nonetheless, concentrations of p,p'-DDE and chlordanes were higher than New York State Ambient Water Quality Standards for the protection of human health from the consumption of fish. Spatial distributions of freely dissolved OCPs in both lakes were influenced by loadings from areas of concern and the water circulation patterns. Flux calculations indicated net deposition of γ-hexachlorocyclohexane, heptachlor-epoxide, and α- and β-endosulfan (-0.02 to -33 ng/m(2)/day) and net volatilization of heptachlor, aldrin, trans-chlordane, and trans-nonachlor (0.0 to 9.0 ng/m(2)/day) in most samples. PMID:25019318

  11. Time-resolved fast-neutron radiography of air-water two-phase flows in a rectangular channel by an improved detection system

    International Nuclear Information System (INIS)

    In a previous work, we have demonstrated the feasibility of high-frame-rate, fast-neutron radiography of generic air-water two-phase flows in a 1.5 cm thick, rectangular flow channel. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany, using an multi-frame, time-resolved detector developed for fast neutron resonance radiography. The results were however not fully optimal and therefore we have decided to modify the detector and optimize it for the given application, which is described in the present work. Furthermore, we managed to improve the image post-processing methodology and the noise suppression. Using the tailored detector and the improved post-processing, significant increase in the image quality and an order of magnitude lower exposure times, down to 3.33 ms, have been achieved with minimized motion artifacts. Similar to the previous study, different two-phase flow regimes such as bubbly slug and churn flows have been examined. The enhanced imaging quality enables an improved prediction of two-phase flow parameters like the instantaneous volumetric gas fraction, bubble size, and bubble velocities. Instantaneous velocity fields around the gas enclosures can also be more robustly predicted using optical flow methods as previously

  12. Implications of surfactant-induced flow for miscible-displacement estimation of air-water interfacial areas in unsaturated porous media.

    Science.gov (United States)

    Costanza-Robinson, Molly S; Zheng, Zheng; Henry, Eric J; Estabrook, Benjamin D; Littlefield, Malcolm H

    2012-10-16

    Surfactant miscible-displacement experiments represent a conventional means of estimating air-water interfacial area (A(I)) in unsaturated porous media. However, changes in surface tension during the experiment can potentially induce unsaturated flow, thereby altering interfacial areas and violating several fundamental method assumptions, including that of steady-state flow. In this work, the magnitude of surfactant-induced flow was quantified by monitoring moisture content and perturbations to effluent flow rate during miscible-displacement experiments conducted using a range of surfactant concentrations. For systems initially at 83% moisture saturation (S(W)), decreases of 18-43% S(W) occurred following surfactant introduction, with the magnitude and rate of drainage inversely related to the surface tension of the surfactant solution. Drainage induced by 0.1 mM sodium dodecyl benzene sulfonate, commonly used for A(I) estimation, resulted in effluent flow rate increases of up to 27% above steady-state conditions and is estimated to more than double the interfacial area over the course of the experiment. Depending on the surfactant concentration and the moisture content used to describe the system, A(I) estimates varied more than 3-fold. The magnitude of surfactant-induced flow is considerably larger than previously recognized and casts doubt on the reliability of A(I) estimation by surfactant miscible-displacement.

  13. Time-resolved fast-neutron radiography of air-water two-phase flows in a rectangular channel by an improved detection system

    CERN Document Server

    Zboray, Robert; Mor, Ilan; Bromberger, Benjamin; Tittelmeier, Kai

    2015-01-01

    In a previous work we have demonstrated the feasibility of high-frame-rate, fast-neutron radiography of generic air-water two-phase flows in a 1.5 cm thick, rectangular flow channel. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany, using an multi-frame, time-resolved detector developed for fast neutron resonance radiography. The results were however not fully optimal and therefore we have decided to modify the detector and optimize it for the given application, which is described in the present work. Furthermore, we managed to improve the image post-processing methodology and the noise suppression. Using the tailored detector and the improved post-processing significant increase in the image quality and an order of magnitude lower exposure times, down to 3.33 ms, have been achieved with minimized motion artifacts. Similar to the previous study, different two-phase flow regimes such as bubbly slug and churn flows have been e...

  14. Time-resolved fast-neutron radiography of air-water two-phase flows in a rectangular channel by an improved detection system

    Energy Technology Data Exchange (ETDEWEB)

    Zboray, Robert [Paul Scherrer Institute, PSI Villigen 5232 (Switzerland); Dangendorf, Volker; Bromberger, Benjamin; Tittelmeier, Kai [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig 38116 (Germany); Mor, Ilan [Soreq NRC, Yavne 81800 (Israel)

    2015-07-15

    In a previous work, we have demonstrated the feasibility of high-frame-rate, fast-neutron radiography of generic air-water two-phase flows in a 1.5 cm thick, rectangular flow channel. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany, using an multi-frame, time-resolved detector developed for fast neutron resonance radiography. The results were however not fully optimal and therefore we have decided to modify the detector and optimize it for the given application, which is described in the present work. Furthermore, we managed to improve the image post-processing methodology and the noise suppression. Using the tailored detector and the improved post-processing, significant increase in the image quality and an order of magnitude lower exposure times, down to 3.33 ms, have been achieved with minimized motion artifacts. Similar to the previous study, different two-phase flow regimes such as bubbly slug and churn flows have been examined. The enhanced imaging quality enables an improved prediction of two-phase flow parameters like the instantaneous volumetric gas fraction, bubble size, and bubble velocities. Instantaneous velocity fields around the gas enclosures can also be more robustly predicted using optical flow methods as previously.

  15. Time-resolved fast-neutron radiography of air-water two-phase flows in a rectangular channel by an improved detection system

    Science.gov (United States)

    Zboray, Robert; Dangendorf, Volker; Mor, Ilan; Bromberger, Benjamin; Tittelmeier, Kai

    2015-07-01

    In a previous work, we have demonstrated the feasibility of high-frame-rate, fast-neutron radiography of generic air-water two-phase flows in a 1.5 cm thick, rectangular flow channel. The experiments have been carried out at the high-intensity, white-beam facility of the Physikalisch-Technische Bundesanstalt, Germany, using an multi-frame, time-resolved detector developed for fast neutron resonance radiography. The results were however not fully optimal and therefore we have decided to modify the detector and optimize it for the given application, which is described in the present work. Furthermore, we managed to improve the image post-processing methodology and the noise suppression. Using the tailored detector and the improved post-processing, significant increase in the image quality and an order of magnitude lower exposure times, down to 3.33 ms, have been achieved with minimized motion artifacts. Similar to the previous study, different two-phase flow regimes such as bubbly slug and churn flows have been examined. The enhanced imaging quality enables an improved prediction of two-phase flow parameters like the instantaneous volumetric gas fraction, bubble size, and bubble velocities. Instantaneous velocity fields around the gas enclosures can also be more robustly predicted using optical flow methods as previously.

  16. A Novel Satellite Mission Concept for Upper Air Water Vapour, Aerosol and Cloud Observations Using Integrated Path Differential Absorption LiDAR Limb Sounding

    Directory of Open Access Journals (Sweden)

    Claudia Weitnauer

    2012-03-01

    Full Text Available We propose a new satellite mission to deliver high quality measurements of upper air water vapour. The concept centres around a LiDAR in limb sounding by occultation geometry, designed to operate as a very long path system for differential absorption measurements. We present a preliminary performance analysis with a system sized to send 75 mJ pulses at 25 Hz at four wavelengths close to 935 nm, to up to 5 microsatellites in a counter-rotating orbit, carrying retroreflectors characterized by a reflected beam divergence of roughly twice the emitted laser beam divergence of 15 µrad. This provides water vapour profiles with a vertical sampling of 110 m; preliminary calculations suggest that the system could detect concentrations of less than 5 ppm. A secondary payload of a fairly conventional medium resolution multispectral radiometer allows wide-swath cloud and aerosol imaging. The total weight and power of the system are estimated at 3 tons and 2,700 W respectively. This novel concept presents significant challenges, including the performance of the lasers in space, the tracking between the main spacecraft and the retroreflectors, the refractive effects of turbulence, and the design of the telescopes to achieve a high signal-to-noise ratio for the high precision measurements. The mission concept was conceived at the Alpbach Summer School 2010.

  17. Reliability of environmental fate modeling results for POPs based on various methods of determining the air/water partition coefficient (log KAW)

    Science.gov (United States)

    Odziomek, K.; Gajewicz, A.; Haranczyk, M.; Puzyn, T.

    2013-07-01

    Air-water partition coefficient (KAW) is one of the key parameters determining environmental behavior of Persistent Organic Pollutants (POPs). Experimentally measured values of KAW are still unavailable for majority of POPs, thus alternative methods of supplying data, including Quantitative Structure-Property Relationships (QSPR) modeling, are often in use. In this paper, applicability of two QSPR methods of predicting KAW were compared with each other in the context of further application of the predicted data in environmental transport and fate studies. According to the first (indirect) method, KAW is calculated from previously predicted values of octanol-water (KOW) and octanol-air (KOA) partition coefficients. In the second (direct) approach, KAW is calculated, based on the estimated value of Henry's law constant (KH) and then adjusted to ensure its consistency with the other two partition coefficients (KOW and KOA). Although the indirect method carries theoretically twice as much error as the direct method, when the predicted values of KAW are then utilized as an input to the environmental fate model The OECD POV and LRTP Screening Tool, ver. 2.2, the indirect method elicits much higher and therefore much more restrictive values of overall persistence (POV) and transfer efficiency (TE) than its equivalent (direct method). High uncertainties related to the application of the direct method result mainly from the necessary adjustment procedure.

  18. Stereoselective synthesis of (2S,3S,4Z-4-fluoro-1,3-dihydroxy-2-(octadecanoylaminooctadec-4-ene, [(Z-4-fluoroceramide], and its phase behavior at the air/water interface

    Directory of Open Access Journals (Sweden)

    2008-04-01

    for natural ceramide.ConclusionsAsymmetric aldol reaction proved to be successful for the preparation of enantiopure 4-fluoroceramide. Surface/pressure isotherms and hysteresis curves of ceramide and its 4-fluoro derivative showed that the presence of fluorine leads to stronger intermolecular interactions between the hydrophobic chains of neighboring molecules, and therefore to increasing stability of the monolayer of 4-fluoroceramide at the air water interface.

  19. Regional assessment of anthropogenic impacts on air, water and soil, case: Huasteca Hidalguense, Mexico; Evaluacion regional del impacto antropogenico sobre aire, agua y suelo, caso: Huasteca Hidalguense, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gordillo Martinez, Alberto Jose; Cabrera Cruz, Rene Bernardo Elias; Hernandez Mariano, Marisol; Galindo, Erick; Otazo, Elena; Prieto, Francisco [Centro de Investigaciones Quimicas, Universidad Autonoma del Estado de Hidalgo, Pachuca, Hidalgo (Mexico)]. E-mail: gordillo@uaeh.edu.mx; rcabreracruz@yahoo.com.mx

    2010-08-15

    The state of Hidalgo, Mexico presents an important environmental problem that manifests itself in different ways. To identify the sources, types and the magnitude of pollutants, an inventory of sources of industrial and domestic pollution for air, water and soil in ten municipalities of the Huasteca Region of the state was carried out using the technique of Rapid Assessment of Sources of Environmental Pollution and the results are reported in this paper. A total of combined pollutants emitted was 116 978.95 tons/year. Gasoline vehicles contributed 11 039 tons/year of air pollutants and diesel vehicles 1521 tons/year. For water, industrial sources contributed 22 496 tons/year and domestic effluents 15 776 tons/year. Soil pollution was a result of industrial solid waste, 4025 tons/year, and municipal solid waste, 62 121 tons/year. By municipality, Huejutla de Reyes is the most polluted in air, water and soil, with 53 % of the regional total. These results were evaluated in relation to environmental quality of each medium based on the Mexican regulations; these levels are above permissible limits for water and soil. A database with relevant information was prepared as a support for efficient management of pollutant emissions, provide base mark data for complementary studies, and to promote the future conservation of environmental quality and the biological richness of the area. [Spanish] El estado de Hidalgo, Mexico presenta una importante problematica ambiental que se manifiesta de manera heterogenea a lo largo de su territorio. Existe la necesidad de conocer las fuentes, tipos de agentes contaminantes y su magnitud. En este trabajo se realizo un inventario de la contaminacion emitida por fuentes de origen industrial y domestico en aire, agua y suelo en diez municipios de la region de la Huasteca por medio de la tecnica de Evaluacion Rapida de Fuentes de Contaminacion Ambiental (ERFCA). El total de la contaminacion emitida fue de 116 978.95 ton/ano. Las emisiones al

  20. Nisin Z, mutant nisin Z and lacticin 481 interactions with anionic lipids correlate with antimicrobial activity. A monolayer study

    NARCIS (Netherlands)

    Demel, Rudolf A.; Peelen, Tamara; Siezen, Roland J.; Kruijff, Ben de; Kuipers, Oscar P.

    1996-01-01

    Monomolecular layers of lipids at the air/water interface have been used as a model membrane to study membrane interactions of the lantibiotic nisin. The natural lantibiotics nisin A and nisin Z proved to have a high affinity for the anionic lipids phosphatidylglycerol and bis(phosphatidyl)glycerol

  1. Morphology and thermochromic phase transition of merocyanine J-aggregate monolayers at the air-water and solid-water interfaces

    Science.gov (United States)

    Kato, Noritaka; Saito, Kentaro; Serata, Toshinori; Aida, Hiroaki; Uesu, Yoshiaki

    2001-07-01

    Thermal changes of the merocyanine dye (MD) monolayer at the air-water interface were investigated under various subphase conditions in order to elucidate the formation mechanism and to control morphological and chromatic properties of two-dimensional MD J-aggregate crystallites (JC) formed in the monolayer. The dissociation temperature (Td) of the JC to the monomer MD was measured for different counterions of MD molecules in the subphase. The JC size was found to be dependent on the subphase temperature; it becomes larger when the JC is formed at a temperature closer to Td. This phenomenon is qualitatively reproduced by the numerical simulation of the Cahn-Hilliard equation. In the case of the MD monolayer on the subphase which contains two kinds of counterions, it exhibits a reversible thermochromic transition between two different JC states. The chromatic change is discrete, and is attributed to the structural phase transition of the JC induced by the mutual recombination of two kinds of counterions to MD molecules. The structural difference between the high and low temperature JC states is examined by the point dipole model. The transition temperature and thermal hysteresis width can be varied by the fraction of 2 counterions. In situ observations using a multipurpose nonlinear optical microscope revealed that the transition is of first order and the nucleation and growth process of the low temperature phase in the high temperature matrix was observed. The JC size of the low temperature phase became much larger through the recrystallization process. For future application of this phenomenon, an airtight cell consisting of two monolayers at the solid-water interface and the subphase was developed. In the cell, the same reversible transition occurs, but with a slow relaxation.

  2. Controlled deposition of functionalized silica coated zinc oxide nano-assemblies at the air/water interface for blood cancer detection.

    Science.gov (United States)

    Pandey, Chandra Mouli; Dewan, Srishti; Chawla, Seema; Yadav, Birendra Kumar; Sumana, Gajjala; Malhotra, Bansi Dhar

    2016-09-21

    We report results of the studies relating to controlled deposition of the amino-functionalized silica-coated zinc oxide (Am-Si@ZnO) nano-assemblies onto an indium tin oxide (ITO) coated glass substrate using Langmuir-Blodgett (LB) technique. The monolayers have been deposited by transferring the spread solution of Am-Si@ZnO stearic acid prepared in chloroform at the air-water interface, at optimized pressure (16 mN/m), concentration (10 mg/ml) and temperature (23 °C). The high-resolution transmission electron microscopic studies of the Am-Si@ZnO nanocomposite reveal that the nanoparticles have a microscopic structure comprising of hexagonal assemblies of ZnO with typical dimensions of 30 nm. The surface morphology of the LB multilayer observed by scanning electron microscopy shows uniform surface of the Am-Si@ZnO film in the nanometer range (<80 nm). These electrodes have been utilized for chronic myelogenous leukemia (CML) detection by covalently immobilizing the amino-terminated oligonucleotide probe sequence via glutaraldehyde as a crosslinker. The response studies of these fabricated electrodes carried out using electrochemical impedance spectroscopy show that this Am-Si@ZnO LB film based nucleic acid sensor exhibits a linear response to complementary DNA (10(-6)-10(-16) M) with a detection limit of 1 × 10(-16) M. This fabricated platform is validated with clinical samples of CML positive patients and the results demonstrate its immense potential for clinical diagnosis. PMID:27590542

  3. Structure Parameter Optimization of Air-water Dual-source Compound Heat-exchanger%空气-水双热源复合换热器结构参数优化

    Institute of Scientific and Technical Information of China (English)

    张超; 董家昀; 赵晓丹; 周光辉

    2012-01-01

    空气-水双热源复合换热器是太阳能-空气双热源复合热泵系统的核心部件,空气-水双热源复台换热器的结构参数对空气-水双热源复合换热器的换热性能以及太阳能-空气双热源复合热泵的系统性能具有重要影响.建立了太阳能-空气双热源复合热泵系统的数学模型,利用数学模拟的方法研究了空气-水双热源复合换热器结构参数对热泵系统能效比的影响,并确定了模拟工况下换热器结构参数的优化方案.%The air-water dual-source compound heat-exchanger is the key component of the solar-air dual-source compound heat pump system. The heat-exchanging performance of the air-water dual-source compound heat-exchanger and the system performance of the solar-air dual-source compound heat pump system are largely depended on the structure parameter of the air-water dual-source compound heat-exchanger. The mathematic model of the solar-air dual-source compound heat pump system has been established. The mathematic simulation method has been used to study the effect of the structure parameters of air-water dual-source compound heat-exchanger on the energy-efficiency ratio of the solar-air dual-source compound heat pump system, and the optimization scheme of the structure parameters under the simulating condition have been determined.

  4. Counter-current flow limitation in a model of the hot leg of a PWR—Comparison between air/water and steam/water experiments

    International Nuclear Information System (INIS)

    Highlights: ► Investigation of CCFL in a model of a PWR hot leg with rectangular cross-section. ► Visualisation of steam/water CCFL over large windows at reactor typical boundary conditions. ► Comparison between low pressure air experiments and high pressure steam experiments. ► Confirmation of the Wallis similarity to scale flooding in the hot leg over a wide range of boundary conditions. - Abstract: In order to investigate the two-phase flow behaviour in a complex reactor-typical geometry and to supply suitable data for computational fluid dynamics (CFD) code validation, a model of the hot leg of a pressurised water reactor was built at Helmholtz-Zentrum Dresden Rossendorf (HZDR). The hot leg model is devoted to optical measurement techniques, therefore, a flat test section design was chosen and equipped with large windows. In order to enable the operation at high pressures, the test section is installed in the pressure chamber of the TOPFLOW (Transient twO Phase FLOW) test facility of HZDR, which is used to perform the experiments under pressure equilibrium with the inside atmosphere. Counter-current flow limitation (CCFL) experiments were performed, simulating the reflux-condenser cooling mode appearing in small break loss-of-coolant-accident (LOCA) scenarios. The fluids used were air and water at room temperature and pressures of up to 3.0 bar, as well as steam and water at pressures of up to 50 bar and the corresponding saturation temperature of 264 °C. One selected 50 bar experiment is presented in detail: the observed behaviour is analysed and illustrated by typical high-speed camera images of the flow. Furthermore, the flooding characteristics obtained from the different experimental runs are presented in terms of the Wallis parameter and Kutateladze number, which are commonly used in the literature. However, a discrepancy was first observed between the air/water and steam/water series. Further investigations show that the steam was probably wet

  5. Adsorption of egg phosphatidylcholine to an air/water and triolein/water bubble interface: use of the 2-dimensional phase rule to estimate the surface composition of a phospholipid/triolein/water surface as a function of surface pressure.

    Science.gov (United States)

    Mitsche, Matthew A; Wang, Libo; Small, Donald M

    2010-03-11

    Phospholipid monolayers play a critical role in the structure and stabilization of biological interfaces, including all membranes, the alveoli of the lungs, fat droplets in adipose tissue, and lipoproteins. The behavior of phospholipids in bilayers and at an air-water interface is well understood. However, the study of phospholipids at oil-water interfaces is limited due to technical challenges. In this study, egg phosphatidylcholine (EPC) was deposited from small unilamellar vesicles onto a bubble of either air or triolein (TO) formed in a low-salt buffer. The surface tension (gamma) was measured using a drop tensiometer. We observed that EPC binds irreversibly to both interfaces and at equilibrium exerts approximately 12 and 15 mN/m of pressure (Pi) at an air and TO interface, respectively. After EPC was bound to the interface, the unbound EPC was washed out of the cuvette, and the surface was compressed to study the Pi/area relationship. To determine the surface concentration (Gamma), which cannot be measured directly, compression isotherms from a Langmuir trough and drop tensiometer were compared. The air-water interfaces had identical characteristics using both techniques; thus, Gamma on the bubble can be determined by overlaying the two isotherms. Both TO and EPC are surface-active, so in a mixed TO/EPC monolayer, both molecules will be exposed to water. Since TO is less surface-active than EPC, as Pi increases, the TO is progressively ejected. To understand the Pi/area isotherm of EPC on a TO bubble, a variety of TO-EPC mixtures were spread at the air-water interface. The isotherms show an abrupt break in the curve caused by the ejection of TO from the monolayer into a new bulk phase. By overlaying the compression isotherm above the ejection point with a TO bubble compression isotherm, Gamma can be estimated. This allows determination of Gamma of EPC on a TO bubble as a function of Pi. PMID:20151713

  6. Interaction of L-Phenylalanine with a Phospholipid Monolayer at the Water-Air Interface.

    Science.gov (United States)

    Griffith, Elizabeth C; Perkins, Russell J; Telesford, Dana-Marie; Adams, Ellen M; Cwiklik, Lukasz; Allen, Heather C; Roeselová, Martina; Vaida, Veronica

    2015-07-23

    The interaction of L-phenylalanine with a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayer at the air-water interface was explored using a combination of experimental techniques and molecular dynamics (MD) simulations. By means of Langmuir trough methods and Brewster angle microscopy, L-phenylalanine was shown to significantly alter the interfacial tension and the surface domain morphology of the DPPC film. In addition, confocal microscopy was used to explore the aggregation state of L-phenylalanine in the bulk aqueous phase. Finally, MD simulations were performed to gain molecular-level information on the interactions of L-phenylalanine and DPPC at the interface. Taken together, these results show that L-phenylalanine intercalates into a DPPC film at the air-water interface, thereby affecting the surface tension, phase morphology, and ordering of the DPPC film. The results are discussed in the context of biological systems and the mechanism of diseases such as phenylketonuria.

  7. Miscibility of Two Components in a Binary Mixture of 9-Phenyl Anthracene Mixed with Stearic Acid or Polymethyl Methacrylate at Air-Water Interface

    Institute of Scientific and Technical Information of China (English)

    P. K. Paul; Md. N. Islam; D. Bhattacharjee; S. A. Hussain

    2007-01-01

    We report the miscibility characteristics of two components in a binary mixture of 9-phenyl anthracene (PA) mixed with stearic acid (SA) or polymethyl methacrylate (PMMA). The behaviour of surface pressure versus area per molecule isotherms reveal that the area per molecule decreases systematically with increasing molefractions of PA. The characteristics of areas per molecule versus molefractions and collapse pressure vs molefraction indicate that various interactions involved among the sample and matrix molecules. The interaction scheme is found to change with the change in surface pressure and molefraction of mixing. Scanning electron microscopic study confirms the aggregation of PA molecules in the mixed films.

  8. The RNA core weakly influences the interactions of the bacteriophage MS2 at key environmental interfaces

    KAUST Repository

    Nguyen, Thanh H.

    2011-01-01

    The effect of the RNA core on interfacial interactions of the bacteriophage MS2 was investigated. After removal of the RNA core, empty intact capsids were characterized and compared to untreated MS2. Electron density of untreated MS2 and RNA-free MS2 were characterized by transmission electron microscopy (TEM) and synchrotron-based small angle spectroscopy (SAXS). Suspensions of both particles exhibited similar electrophoretic mobility across a range of pH values. Similar effects were observed at pH 5.9 across a range of NaCl or CaCl2 concentrations. We compared key interfacial interactions (particle-particle and particle/air-water interface) between suspensions of each type of particle using time resolved dynamic light scattering (TR-DLS) to observe and quantify aggregation kinetics and axisymmetric drop shape analysis to measure adsorption at the air-water interface. Both suspensions showed insignificant aggregation over 4 h in 600 mM NaCl solutions. In the presence of Ca2+ ions, aggregation of both types of particles was consistent with earlier aggregation studies and was characterized by both reaction-limited and diffusion-limited regimes occurring at similar [Ca2+]. However, the removal of the RNA from MS2 had no apparent effect on the aggregation kinetics of particles. Despite some differences in the kinetics of adsorption to the air-water interface, the changes in surface tension which result from particle adsorption showed no difference between the untreated MS2 and RNA-free MS2. The interactions and structure of particles at the air-water interface were further probed using interfacial dilational rheology. The surface elasticity (E s) and surface viscosity (ηs) at the interface were low for both the untreated virus and the RNA-free capsid. This observation suggests that the factors that impact the adsorption kinetics are not important for an equilibrated interface. © 2011 The Royal Society of Chemistry.

  9. Analysis of the Asymmetric Synergy in the Adsorption of Zwitterionic-Ionic Surfactant Mixtures at the Air-Water Interface below and above the Critical Micelle Concentration.

    Science.gov (United States)

    Li, Peixun; Ma, Kun; Thomas, Robert K; Penfold, Jeffrey

    2016-04-21

    Surface tension (ST) and neutron reflection (NR) measurements have been made on a series of mixtures of two ionic surfactants, one anionic (SDS) and one cationic (C12TAB), with the two zwitterionic surfactants dodecyldimethylammonium propanesulfonate (C12SB) and dodecyldimethylammonium acetate C12CB. The anionic surfactant SDS interacts equally strongly with both zwitterionics and the C12TAB less strongly. For the SDS-C12SB mixtures simultaneous fitting of ST and NR data made it possible to use the pseudophase approximation with an expansion of the excess free energy, GE, up to and including the quartic term. GE is asymmetric for the adsorbed layer and the minimum occurs at a surface mole fraction, xSDS, of 0.38 with a depth of -2.8RT. NR was also used to follow the adsorption above the CMC, and the changes showed that the intramicellar interaction is more asymmetric, but weaker than the surface interaction with a depth of GE of -2.2RT at the minimum of xSDS = 0.23. A strong synergy in the total surface excess was observed above the mixed CMC with an enhancement over the adsorption of the pure components of about 45%, which appears to result from a sharp variation of the packing with surface composition coupled with the effects of the strongly asymmetric micellization. NR data on SDS-C12CB showed that GE for both surface and micelles was similarly asymmetric to those for SDS-C12SB, but there is no strong synergy in adsorption. This is attributed to the more rigid headgroup. C12TAB-C12SB has an asymmetric GE for both surface and micelle similar to those for SDS-C12SB but the depths are smaller at -0.6RT and -0.5RT, respectively, and there is no synergy in the total adsorption. PMID:27029532

  10. Influence of temperature on the limits for the deflagration-detonation transition in hydrogen-/air-/water vapor mixtures. Final report

    International Nuclear Information System (INIS)

    For assessing the danger potential of a hydrogen burn during a postulated LOCA with core meltdown a detailed knowledge of the combustion behaviour of hydrogen is necessary. The reached flame velocities and thus the pressure loads imposed on the containment structures highly depend on mixture composition, thermodynamic boundary conditions, the interactions between turbulence inherent to the combustion induced gas motion and the flame front. This report involves experiments on 1. Unsteady flame propagation in an explosion tube with flow obstacles (turbulent flame acceleration and DDT-limits); 2. Steady flames above a flow obstacle; 3. Unsteady flame passing a single flow obstacle. (HP)

  11. Experimental investigation of droplet separation in a horizontal counter-current air/water stratified flow; Experimentelle Untersuchung der Tropfenabscheidung einer horizontalen, entgegengerichteten Wasser/Luft-Schichtenstroemung

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Stephan Gerhard

    2015-07-01

    A stratified counter-current two-phase gas/liquid flow can occur in various technical systems. In the past investigations have mainly been motivated by the possible occurrence of these flows in accident scenarios of nuclear light water-reactors and in numerous applications in process engineering. However, the precise forecast of flow parameters, is still challenging, for instance due to their strong dependency on the geometric boundary conditions. A new approach which uses CFD methods (Computational Fluid Dynamics) promises a better understanding of the flow phenomena and simultaneously a higher scalability of the findings. RANS methods (Reynolds Averaged Navier Stokes) are preferred in order to compute industrial processes and geometries. A very deep understanding of the flow behavior and equation systems based on real physics are necessary preconditions to develop the equation system for a reliable RANS approach with predictive power. Therefore, local highly resolved, experimental data is needed in order to provide and validate the required turbulence and phase interaction models. The central objective of this work is to provide the data needed for the code development for these unsteady, turbulent and three-dimensional flows. Experiments were carried out at the WENKA facility (Water Entrainment Channel Karlsruhe) at the Karlsruhe Institute of Technology (KIT). The work consists of a detailed description of the test-facility including a new bended channel, the measurement techniques and the experimental results. The characterization of the new channel was done by flow maps. A high-speed imaging study gives an impression of the occurring flow regimes, and different flow phenomena like droplet separation. The velocity distributions as well as various turbulence values were investigated by particle image velocimetry (PIV). In the liquid phase fluorescent tracer-particles were used to suppress optical reflections from the phase surface (fluorescent PIV, FPIV

  12. Avaliação da intensidade de contaminação de pontas de seringa tríplice Evaluation of the bacterial contamination of air/water syringes tips

    Directory of Open Access Journals (Sweden)

    Eliza Maria Agueda RUSSO

    2000-09-01

    Full Text Available O controle de infecção cruzada em consultórios odontológicos inclui cuidados especiais com as seringas tríplices. Os autores pesquisaram a intensidade de contaminação pela microbiota bucal, de pontas de seringas tríplices usadas no atendimento a pacientes de Dentística Restauradora. Cinqüenta pontas descartáveis (Riskcontrol, Injecta Prod. Odontológicos foram avaliadas: 10, imediatamente após a abertura da embalagem; 30, após o uso em pacientes; e 10, após o uso e a desinfecção com álcool etílico 70% P/V, friccionado por um minuto. Em câmara de fluxo laminar, as pontas foram "roladas" sobre a superfície de Tryptic Soy Agar, suplementado com 5% de sangue desfibrinado de carneiro. Após 96 horas de incubação anaeróbia, foi feita a avaliação da quantidade de unidades formadoras de colônias (ufc desenvolvidas. Confirmando a informação do fabricante, as pontas estavam estéreis quando retiradas da embalagem. Em todas as pontas usadas em pacientes, observou-se um número incontável de ufc (maior que 300, revelando intensa contaminação. Nas pontas usadas e desinfetadas com álcool etílico 70% P/V, verificou-se apreciável redução na contagem de colônias (1 a 100 ufc, mas incompatível com a segurança biológica. Os resultados sugerem, como condição ideal, o uso de pontas descartáveis nas seringas tríplices.Effective infection control procedures to prevent cross-contamination in the dental office include care with air/water syringes. The authors had the purpose to verify the bacterial contamination of air/water syringes used in patients seen at the Restorative Dental Clinic, School of Dentistry, University of São Paulo, Brazil. Fifty disposable tips (Riskcontrol, Injecta Prod. Odontológicos were analysed: 10, immediately after the package was opened; 10, after a single use followed by disinfection with 70% alcohol for one minute; 30, after a single use without any posterior disinfection. The samples were

  13. Statistical characterization of the optical interaction at a supercavitating interface

    Science.gov (United States)

    Walters, Gage; Kane, Tim; Jefferies, Rhett; Antonelli, Lynn

    2016-05-01

    The optical characteristics of an air/water interface have been widely studied for natural interface formations. However, the creation and management of artificial cavities creates a complicated interaction of gas and liquid that makes optical sensing and communication through the interface challenging. A ventilated cavity can reduce friction in underwater vehicles, but the resulting bubble drastically impedes optical and acoustic communication propagation. The complicated interaction at the air/water boundary yields surface waves and turbulence that make modeling and compensating of the optical properties difficult. Our experimental approach uses a narrow laser beam to probe the surface of the interface and measure the beam deflection and lensing effects. Using a vehicle model with a cavitator in a water tunnel, a laser beam is propagated outward from the model through the boundary and projected onto a target grid. The beam projection is captured using a high-speed camera, allowing us to measure and analyze beam shape and deflection. This approach has enabled us to quantify the temporal and spatial periodic variations in the beam propagation through the cavity boundary and fluid.

  14. TPPS和Gemini表面活性剂的复合膜及其手性的研究%Supramolecular Assembly and Chirality of a Complex Film between Achiral TPPS and a Gemini Surfactant at the Air/water Interface

    Institute of Scientific and Technical Information of China (English)

    张莉; 王金本; 刘鸣华

    2004-01-01

    研究了一种新的gemini表面活性剂(C 12H24-α,ω-(C12H25N+(CH3)2Br-)2,(简写为C12-C12-C12)和TPPS在气液界面上形成的复合膜及其手性.实验发现,单独C12-C12-C12不能在纯水表面形成稳定的单分子膜,但当亚相中存在TPPS时,可形成稳定的单分子膜.通过水平提拉法将复合膜转移到固体基板上,发现在适当的pH值条件下,TPPS可在复合膜中形成J-聚集体,并且发现,尽管Gemini表面活性剂和TPPS都是非手性的,TPPS的J-聚集体表现出强烈的Cotton效应.另外,gemini表面活性剂的两个正电荷中心对TPPS的J-聚集体的手性并不能表现出协同效应.%Supramolecular assembly and chirality between a novel gemini surfactant (C12H24-α, ω-(C12H25N + (CH3)2Br-)2,(abbreviated as C12-C12-C12) and TPPS (tetrakis(4-sulfonatophenyl) porphine) at the air/water interface were investigated. It was found that although the gemini surfactant itself could not form a stable monolayer at the air/water interface, when there existed TPPS in the subphase, a stable complex monolayer could be formed. The complex monolayer could be transferred onto solid substrate by a horizontal lifting method. At a certain pH value of the subphase, TPPS could form a J-aggregate. It was further found that the J-aggregate of TPPS showed a strong split Cotton effect in the transferred film although both the gemini surfactant and TPPS are achiral. Further investigation through AFM measurements revealed that the nanothread formed in the transferred film was responsible for the chirality of the multilayer film. In addition, the two positive charge center of the gemini surfactant did not necessarily play the cooperative role in inducing the chirality of TPPS J-aggregate.

  15. 水库水气界面温室气体通量监测方法综述%Review of methods for measuring greenhouse gas flux from the air-water interface of reservoirs

    Institute of Scientific and Technical Information of China (English)

    赵炎; 曾源; 吴炳方; 陈永柏; 王强; 袁超

    2011-01-01

    Carbon dioxide (CO2) and methane ( CH4 ) produced during decomposition of organic matter (OM) in reservoirs are emitted from the air-water interface either by diffusion or ebullition.The static-chamber, gradient descent, invert funnel, TDLAS (Tunable Diode Laser Absorption Spectroscopy) and eddy covariance are commonly used methods for measuring CO2 and CH4 fluxes from the air-water interface of reservoirs in abroad.In this study, we review the principle and application of above mentioned methods, their pros and cons, as well as applicability limitations.Factors affecting the emission of greenhouse gases from reservoirs are analyzed from the perspective of water,terrestrial and climatic environment.Prospects of the application of remote sensing technologies for monitoring greenhouse gas emissions from reservoirs are presented.Using remote sensing technologies and surface measuring methods can be complementary to each other in both time and space.Our study provides a valuable reference for monitoring greenhouse gas emissions from reservoirs in China.%水库水体中的有机碳,经过水中微生物代谢分解,生成甲烷、二氧化碳等温室气体,通过扩散、气泡等方式,经由水气界面排向大气.目前国外对水库水气界面的温室气体通量监测已经发展了静态箱法、梯度法、倒置漏斗法、TDLAS法以及涡度相关法等.综述了以上监测方法的原理、应用、优缺点及适用范围,从水体、陆地和气候环境方面分析了影响水气界面温室气体排放通量的因素,展望了遥感技术在水库温室气体通量监测中的应用前景,通过遥感技术与水面监测相结合,实现两者的时空互补.对国外开展水库温室气体通量监测的方法进行综述,可为国内水库开展相关监测提供参考.

  16. Manipulating perfume delivery to the interface using polymer-surfactant interactions.

    Science.gov (United States)

    Bradbury, Robert; Penfold, Jeffrey; Thomas, Robert K; Tucker, Ian M; Petkov, Jordan T; Jones, Craig

    2016-03-15

    Enhanced delivery of perfumes to interfaces is an important element of their effectiveness in a range of home and personal care products. The role of polyelectrolyte-surfactant mixtures to promote perfume adsorption at interfaces is explored here. Neutron reflectivity, NR, was used to quantify the adsorption of the model perfumes phenylethanol, PE, and linalool, LL, at the air-water interface in the presence of the anionic surfactant sodium dodecylsulfate, SDS, and the cationic polyelectrolytes, poly(dimethyldiallyl ammonium chloride), polydmdaac, and poly(ethyleneimine), PEI. The strong SDS-polydmdaac interaction dominates the surface adsorption in SDS-polymer-perfume (PE, LL) mixtures, such that the PE and LL adsorption is greatly suppressed. For PEI-SDS-perfume mixtures the PEI-LL interaction competes with the SDS-PEI interaction at all pH at the surface and significant LL adsorption occurs, whereas for PE the PEI-SDS interaction dominates and the PE adsorption is greatly reduced. The use of the strong surface polyelectrolyte-ionic surfactant interaction to manipulate perfume adsorption at the air-water interface has been demonstrated. In particular the results show how the competition between polyelectrolyte, surfactant and perfume interactions at the surface and in solution affect the partitioning of perfumes to the surface.

  17. Slug flow transitions in horizontal gas/liquid two-phase flows. Dependence on channel height and system pressure for air/water and steam/water two-phase flows

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hideo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-05-01

    The slug flow transitions and related phenomena for horizontal two-phase flows were studied for a better prediction of two-phase flows that typically appear during the reactor loss-of-coolant accidents (LOCAs). For better representation of the flow conditions experimentally, two large-scaled facility: TPTF for high-pressure steam/water two-phase flows and large duct test facility for air/water two-phase flows, were used. The visual observation of the flow using a video-probe was performed in the TPTF experiments for good understanding of the phenomena. The currently-used models and correlations based mostly on the small-scale low-pressure experiments were reviewed and improved based on these experimental results. The modified Taitel-Dukler model for prediction of transition into slug flow from wavy flow and the modified Steen-Wallis correlation for prediction of onset of liquid entrainment from the interfacial waves were obtained. An empirical correlation for the gas-liquid interfacial friction factor was obtained further for prediction of liquid levels at wavy flow. The region of slug flow regime that is generally under influences of the channel height and system pressure was predicted well when these models and correlations were applied together. (author). 90 refs.

  18. 超临界屏蔽电泵用空-水冷却的热屏结构%Construction of the Air-water Cooled Heat Shield of the Screened Pump Operating Under the Critical Condition

    Institute of Scientific and Technical Information of China (English)

    韩志秋; 邢乃国; 吴兴刚

    2013-01-01

    The heat shield was used to isolate the heat from pump to motor for protection purpose. Construction of the air-water cooled heat shield was design in accordance with the axial dimension and requirement of saving materi-als. The raw materials were decreased while the axial di-mension of pump set was reduced, to improve the reliability of screened pumps operating under high temperature and pressure.%热屏在屏蔽电泵中能够阻隔泵端的热量传递到电机端,起到保护电机的作用。根据机组轴向尺寸及节省材料的要求,设计了空水冷热屏结构,增强了隔热能力,在减少原材料的同时减小机组的轴向尺寸,提高了高温高压屏蔽电泵的可靠性。

  19. Simulated Solvation of Organic Ions II: Study of Linear Alkylated Carboxylate Ions in Water Nanodrops and in Liquid Water. Propensity for Air/Water Interface and Convergence to Bulk Solvation Properties.

    Science.gov (United States)

    Houriez, Céline; Meot-Ner Mautner, Michael; Masella, Michel

    2015-09-10

    We investigated the solvation of carboxylate ions from formate to hexanoate, in droplets of 50 to 1000 water molecules and neat water, by computations using standard molecular dynamics and sophisticated polarizable models. The carboxylate ions from methanoate to hexanoate show strong propensity for the air/water interface in small droplets. Only the ions larger than propanoate retain propensity for the interface in larger droplets, where their enthalpic stabilization by ion/water dispersion is reduced there by 3 kcal mol(-1) per CH2 group. This is compensated by entropy effects over +3.3 cal mol(-1) K(-1) per CH2 group. On the surface, the anionic headgroups are strongly oriented toward the aqueous core, while the hydrophobic alkyl chains are repelled into air and lose their structure-making effects. These results reproduce the structure-making effects of alkyl groups in solution, and suggest that the hydrocarbon chains of ionic headgroups and alkyl substituents solvate independently. Extrapolation to bulk solution using standard extrapolation schemes yields absolute carboxylate solvation energies. The results for formate and acetate yield a proton solvation enthalpy of about 270 kcal mol(-1), close to the experiment-based value. The largest carboxylate ions yield a value smaller by about 10 kcal mol(-1), which requires studies in much larger droplets. PMID:26287943

  20. Influence of impeller blade angles of centrifugal pump on air/water two-phase flow performance. Enshin pump haneguruma no hanekaku ga kieki nisoryu seino ni oyobosu eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Sato, S. (Tsuyama National College of Technology, Okayama (Japan)); Furukawa, A. (Kyushu University, Fukuoka (Japan). Faculty of Engineering); Takamatsu, Y. (Ariake National College of Technology, Fukuoka (Japan))

    1993-11-25

    An air/water two-phase flow experiment was carried out on the impellers of a centrifugal pump to study the lifting performance and the flow aspect of gas phase. In the experiment, pressurized air is fed to the blowing pipe of a vertical-shaft type pump through a compressor. Transparent acryl resin was used to form the side wall, etc. of the casing through which a video picture of the flowing aspect of the gas phase was taken. The results showed the flowing aspect suddenly changes due to the increase of air flow rate in a low flow rate region where the angle of incidence of flow is large, and the negative pressure sides of impellers were covered with gas. At this time, the lift lowers sharply and discontinuously and then gradually with extension of the gas residence region. This effect appeared more clearly as the outlet angle of the impeller increased. The experimental result agrees roughly with that of the air-bubble calculation in the region where the gas-liquid ratio is so low that a fine air-bubble flow is maintained, but not in the region where the lift lowers sharply, approaching the result of separate flow calculation. The lift after the gas residence region occurs decreases gradually with the increase of air flow rate, showing the same tendency as the result of separate-flow calculation. 13 refs., 14 figs., 1 tab.

  1. Experimental analysis of ultrasonic signals in air-water vertical upward for void fraction measurement using neural networks; Analise experimental dos sinais ultra-sonicos em escoamentos verticais bifasicos para medicao da fracao de vazios atraves de redes neurais

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Milton Y.; Massignan, Joao P.D.; Daciuk, Rafael J.; Neves Junior, Flavio; Arruda, Lucia V.R. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2008-07-01

    Rheology of emulsion mixtures and void fraction measurements of multiphase flows requires proper instrumentation. Sometimes it is not possible to install this instrumentation inside the pipe or view the flow. Ultrasound technology has characteristics compatible with the requirements of the oil industry. It can assist the production of heavy oil. This study provides important information for an analysis of the feasibility of developing non-intrusive equipment. These probes can be used for measurement of multiphase void fraction and detect the flow pattern using ultrasound. Experiments using simulated upward air-water vertical two-phase flow show that there is a correlation between the acoustic attenuation and the concentration of the gas phase. Experimental data were obtained through the prototype developed for ultrasonic data acquisition. This information was processed and used as input parameters for a neural network classifier. Void fractions ({proportional_to}) were analyzed between 0% - 16%, in increments of 1%. The maximum error of the neural network for the classification of the flow pattern was 6%. (author)

  2. Air-water transfer of hydrogen sulfide

    DEFF Research Database (Denmark)

    Yongsiri, C.; Vollertsen, J.; Rasmussen, M. R.;

    2004-01-01

    The emissions process of hydrogen sulfide was studied to quantify air–water transfer of hydrogen sulfide in sewer networks. Hydrogen sulfide transfer across the air–water interface was investigated at different turbulence levels (expressed in terms of the Froude number) and pH using batch...... experiments. By means of the overall mass–transfer coefficient (KLa), the transfer coefficient of hydrogen sulfide (KLaH2S), referring to total sulfide, was correlated to that of oxygen (KLaO2) (i.e., the reaeration coefficient). Results demonstrate that both turbulence and pH in the water phase play...... a significant role for KLaH2S. An exponential expression is a suitable representation for the relationship between KLaH2S and the Froude number at all pH values studied (4.5 to 8.0). Because of the dissociation of hydrogen sulfide, KLaH2S increased with decreasing pH at a constant turbulence level. Relative...

  3. Engineering Application Schemes of Air-water Dual-source Compound Heat Pump%空气-水双热源复合热泵工程应用方案探讨

    Institute of Scientific and Technical Information of China (English)

    徐俊芳; 赵会刚; 李楠; 田昕; 王皆腾

    2016-01-01

    采用复合热泵技术将太阳能、空气能、地源热泵等两种或几种可再生能源利用形式结合成联合供能系统应用于建筑中,改善单一形式可再生能源在应用中的条件,既可达到节能减排的目的,又能保证系统能量供应的稳定性,具有很好的推广应用价值。从工程应用角度出发探讨了空气-水双热源复合热泵技术在太阳能热水、太阳能供暖、太阳能光/热一体化、地源热泵、余热/废热回收利用等方面的应用方案,为复合源热泵技术在建筑中的推广应用提供参考。%It has advantages, such as complementary advantage, to combine two or more renewable energy forms including solar energy, air energy and ground source heat pump to establish the compound energy supply system in building, and improve the application condition of the single renewable energy system, achieve energy saving and emission reduction and ensure energy supply stability, which has good popularization using value. Considering engineering application, the paper analyzes and discusses engineering application schemes of air-water dual source heat pump technology with solar hot-water supply, solar heating, solar photovoltaic/solar thermal integration, ground source heat pump and waste heat recovery, which provides the reference for the application of the compound source heat pump technology in construction.

  4. Self-Organization of Polystyrene-b-polyacrylic Acid (PS-b-PAA) Monolayer at the Air/Water Interface: A Process Driven by the Release of the Solvent Spreading.

    Science.gov (United States)

    Guennouni, Zineb; Cousin, Fabrice; Fauré, Marie-Claude; Perrin, Patrick; Limagne, Denis; Konovalov, Oleg; Goldmann, Michel

    2016-03-01

    We present an in situ structural study of the surface behavior of PS-b-PAA monolayers at the air/water interface at pH 2, for which the PAA blocks are neutral and using N,N-dimethyformamide (DMF) as spreading solvent. The surface pressure versus molecular area isotherm shows a perfectly reversible pseudoplateau over several cycles of compression/decompression. The width of such plateau enlarges when increasing temperature, conversely to what is classically observed in the case of an in-plane first order transition. We combined specular neutron reflectivity (SNR) experiments with contrast variation to solve the profile of each block perpendicular to the surface with grazing-incidence small-angle scattering (GISAXS) measurements to determine the in-plane structure of the layer. SNR experiments showed that both PS and PAA blocks remain adsorbed on the surface for all surface pressure probed. A correlation peak at Q(xy)* = 0.021 Å(-1) is evidenced by GISAXS at very low surface pressure which intensity first increases on the plateau. When compressing further, its intensity decays while Q(xy)* is shifted toward low Q(xy). The peak fully disappears at the end of the plateau. These results are interpreted by the formation of surface aggregates induced by DMF molecules at the surface. These DMF molecules remain adsorbed within the PS core of the aggregates. Upon compression, they are progressively expelled from the monolayer, which gives rise to the pseudoplateau on the isotherm. The intensity of the GISAXS correlation peak is set by the amount of DMF within the monolayer as it vanishes when all DMF molecules are expelled. This result emphizes the role of the solvent in Langmuir monolayer formed by amphiphilic copolymers which hydrophobic and hydrophilic parts are composed by long polymer chains.

  5. Estudio Experimental de Patrones de Flujo Bifásico Aire-Agua en Tuberías Horizontales y Ligeramente Inclinadas Experimental Study of Air-Water Two-Phase Flow Patterns in Horizontal and Slightly Inclined Pipelines

    Directory of Open Access Journals (Sweden)

    Francisco García

    2009-01-01

    Full Text Available Se realizó un estudio experimental de patrones de flujo bifásico aire-agua en tuberías horizontales y ligeramente inclinadas. Se realizaron 493 experimentos de flujo bifásico aire-agua de los cuales 191 corresponden a tubería horizontal y 302 corresponden a flujo ascendente. Las distribuciones espaciales de los experimentos incluyen los patrones de flujo estratificado liso y ondulado, tapón, anular y burbuja dispersa. Se desarrollan mapas de patrones de flujo experimentales para cada ángulo de inclinación y se evalúa la capacidad de predicción de cuatro modelos mecanicistas y dos modelos de correlación utilizados comúnmente en la literatura para determinar patrones de flujo. Comparando con los valores experimentales se encuentra que los modelos seleccionados tienen un porcentaje de acierto mayor al 75 %.An experimental study in horizontal and slightly inclined pipelines was performed. A total of 493 air-water two-phase flow experiments were carried out, of which 191 correspond to horizontal pipelines and 302 correspond to upward flow. The space distributions of the experiments include the smooth and wavy stratified, slug, annular and dispersed bubble flow patterns. Experimental maps of the flow patterns for each inclination angle are developed and the prediction capability of four mechanistic models and two correlating models commonly used in the literature for determining flow patterns are evaluated. Comparison between calculated and experimental values indicates that the selected models have a success percentage greater than 75%.

  6. Adsorption of Egg-PC to an Air/Water and Triolein/Water Bubble Interface: Use of the 2-Dimensional Phase Rule to Estimate the Surface Composition of a Phospholipid/Triolein/Water Surface as a Function of Surface Pressure

    OpenAIRE

    Mitsche, Matthew A.; Wang, Libo; Small, Donald M.

    2010-01-01

    Phospholipid monolayers play a critical role in the structure and stabilization of biological interfaces including all membranes, the alveoli of the lung, fat droplets in adipose tissue, and lipoproteins. The behavior of phospholipids in bilayers and at an air-water interface is well understood. However, the study of phospholipids at oil-water interfaces is limited due to technical challenges. In this study, egg-phosphatidylcholine (EPC) was deposited from small unilamellar vesicles onto a bu...

  7. Anionic surfactant - Biogenic amine interactions: The role of surfactant headgroup geometry.

    Science.gov (United States)

    Penfold, Jeffrey; Thomas, Robert K; Li, Peixun

    2016-03-15

    Oligoamines and biogenic amines (naturally occurring oligoamines) are small flexible polycations. They interact strongly with anionic surfactants such as sodium dodecyl sulfate, SDS. This results in enhanced adsorption and the formation of layered structures and the formation of layered structures at the air-water interface which depends on surfactant concentration and solution pH. The effect of changing the surfactant headgroup geometry on that interaction and subsequent adsorption is reported here. Neutron reflectivity, NR, results for the surface adsorption of the anionic surfactant sodium diethylene glycol monododecyl ether sulfate, SLES, with the biogenic amine, spermine, are presented, and contrasted with previous data for SDS/spermine mixtures. The enhancement in the adsorption of the surfactant at the air-water interface where monolayer adsorption occurs is similar for both surfactants. However the regions of surfactant concentration and solution pH where surface multilayer adsorption occurs is less extensive for the SLES/spermine mixtures, and occurs only at low pH. The results show how changing the headgroup geometry by the introduction of the ethylene oxide linker group between the alkyl chain and sulfate headgroup modifies the polyamine - surfactant interaction. The increased steric constraint from the polyethylene oxide group disrupts the conditions for surface multilayer formation at the higher pH values. This has important consequences for applications where the modification or manipulation of the surface properties are required. PMID:26724704

  8. Spontaneous surface self-assembly in protein-surfactant mixtures: interactions between hydrophobin and ethoxylated polysorbate surfactants.

    Science.gov (United States)

    Tucker, Ian M; Petkov, Jordan T; Penfold, Jeffrey; Thomas, Robert K; Li, Peixun; Cox, Andrew R; Hedges, Nick; Webster, John R P

    2014-05-01

    The synergistic interactions between certain ethoxylated polysorbate nonionic surfactants and the protein hydrophobin result in spontaneous self-assembly at the air-water interface to form layered surface structures. The surface structures are characterized using neutron reflectivity. The formation of the layered surface structures is promoted by the hydrophobic interaction between the polysorbate alkyl chain and the hydrophobic patch on the surface of the globular hydrophobin and the interaction between the ethoxylated sorbitan headgroup and hydrophilic regions of the protein. The range of the ethoxylated polysorbate concentrations over which the surface ordering occurs is a maximum for the more hydrophobic surfactant polyoxyethylene(8) sorbitan monostearate. The structures at the air-water interface are accompanied by a profound change in the wetting properties of the solution on hydrophobic substrates. In the absence of the polysorbate surfactant, hydrophobin wets a hydrophobic surface, whereas the hydrophobin/ethoxylated polysorbate mixtures where multilayer formation occurs result in a significant dewetting of hydrophobic surfaces. The spontaneous surface self-assembly for hydrophobin/ethoxylated polysorbate surfactant mixtures and the changes in surface wetting properties provide a different insight into protein-surfactant interactions and potential for manipulating surface and interfacial properties and protein surface behavior.

  9. 表面活性素单分子膜在空气/水界面的迟滞现象%Hysteresis Behavior of Surfactin Monolayer at the Air/Water Interface

    Institute of Scientific and Technical Information of China (English)

    杨莹; 宋昌盛; 叶汝强; 牟伯中

    2011-01-01

    Surfactin,one of the most surface-active microbial lipopeptides,can readily form an insoluble monolayer at the air/water interface.Consecutive compression-expansion cycles of surfactin with a β-hydroxyl fatty acid chain consisting of 14 carbon atoms were studied by a Langmuir film balance.A larger hysteresis loop was observed when the compression isotherm reached a plateau compared with that expanded at a lower surface pressure (20 mN· m-1).The 2nd cycle was shifted towards smaller molecular areas compared with the 1st cycle.We also studied the hysteresis cycles of the surfactin monolayer on subphase of different pH values.With a decrease in the subphase pH the hysteresis loop became smaller and the expansion isotherm curve underwent a longer pseudo plateau.Furthermore,the morphologies of the surfactin monolayers in the plateau region,which were transferred onto a mica surface,were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM).Both AFM and SEM images gave three-dimensional surface aggregates with heights ranging from tens to hundreds of nanometers.The above results suggest that the formation of three-dimensional surface aggregates at the plateau region induces a large hysteresis loop in the surfactin monolayer,which can also be attributed to the submergence of molecules into the subphase when the peptide loop in the surfactin molecule is ionized.%表面活性素是一类具有较强表面活性的微生物脂肽类化合物,能在空气/水界面形成不溶性单分子膜.利用Langmuir膜天平测定了表面活性素单分子膜的压缩-扩张循环曲线,发现单分子膜在经历了“平台区”后出现较大的迟滞环,迟滞环的形状与亚相pH有关.将“平台区”的单分子膜转移到云母表面后,用原子力显微镜(AFM)和扫描电子显微镜(SEM)均观察到高度达几十至数百纳米的表面聚集体,说明表面活性素在单分子膜的“平台区”伴随着自聚集.研究结果

  10. Effect of tube size on flow pattern of air-water two-phase flow in vertical tubes%管径对垂直上升管内气液两相流流型的影响

    Institute of Scientific and Technical Information of China (English)

    刘雪敏; 李舟航; 吴玉新; 吕俊复

    2012-01-01

    The air-water two phase flow pattern in vertical tube was experimentally investigated with different tube inner diameter of 20 mm and 8 mm under atmosphere condition. The bubbly flow, slug flow, annular flow and mist flow are observed for two size tubes. Most of the experimental points agree well with Hewitt and Roberts flow pattern map when putting them on the map. With the experimental results, the range line between the flow patterns is suggested for the tubes of 20 mm inner diameter as well as 8 mm. For the vertical flow up, the air superficial velocity when the annular flow appears is independent of the water superficial velocity. The two phase flow patterns range line is similar in tendency and scope for different tubes. The range line between mist flow and annular flow for different tubes is almost overlapping while that between bubbly flow and slug flow is inconsistent for different tubes. The confusion error between bubbly flow and slug flow is of no great importance for heat transfer because the heat transfer for bubbly flow or for slug flow is same. It is believed that the effect of the tube diameter on the two-phase flow in vertical tubes could be neglected, and the Hewitt and Roberts flow pattern map could be adopted without any consideration of tube diameter.%以空气和水作为介质,在管径分别为20mm与8mm的垂直上升管内进行了常压下气液两相流流型的实验研究,得到了这两种管径下泡状流、弹状流、乳状流和环状流等流型,得到的绝大部分实验点与Hewitt和Roberts流型图相符合,并根据实验结果修正了流型图的转化边界.对于气液两相流垂直上升流动,环状流发生所需的气相折算速度几乎不随液相折算速度的变化而变化.不同管径条件下,各种气液两相流流型发生的范围和转换趋势基本一致,乳状流向环状流的转换界限基本重叠,而泡状流与弹状流的界限变化大一些.由于弹状流的换热与泡状流的换热

  11. Floor interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Krogh, Peter; Ludvigsen, Martin;

    2005-01-01

    Within architecture, there is a long tradition of careful design of floors. The design has been concerned with both decorating floors and designing floors to carry information. Ubiquitous computing technology offers new opportunities for designing interactive floors. This paper presents three...... different interactive floor concepts. Through an urban perspective it draws upon the experiences of floors in architecture, and provides a set of design issues for designing interactive floors....

  12. Playful Interaction

    DEFF Research Database (Denmark)

    2003-01-01

    The video Playful Interaction describes a future architectural office, and envisions ideas and concepts for playful interactions between people, materials and appliances in a pervasive and augmented working environment. The video both describes existing developments, technologies and designs...... as well as ideas not yet implemented such as playful modes of interaction with an augmented ball. Playful Interaction has been used as a hybrid of a vision video and a video prototype (1). Externally the video has been used to visualising our new ideas, and internally the video has also worked to inspire...... and encourage dialogue between the different disciplines involved in the EU funded, ‘Disappearing Computer’ project WorkSPACE....

  13. Interactive benchmarking

    DEFF Research Database (Denmark)

    Lawson, Lartey; Nielsen, Kurt

    2005-01-01

    We discuss individual learning by interactive benchmarking using stochastic frontier models. The interactions allow the user to tailor the performance evaluation to preferences and explore alternative improvement strategies by selecting and searching the different frontiers using directional...... in the suggested benchmarking tool. The study investigates how different characteristics on dairy farms influences the technical efficiency....

  14. Kinesthetic Interaction

    DEFF Research Database (Denmark)

    Fogtmann, Maiken Hillerup; Fritsch, Jonas; Kortbek, Karen Johanne

    2008-01-01

    Within the Human-Computer Interaction community there is a growing interest in designing for the whole body in interaction design. The attempts aimed at addressing the body have very different outcomes spanning from theoretical arguments for understanding the body in the design process, to more...... practical examples of designing for bodily potential. This paper presents Kinesthetic Interaction as a unifying concept for describing the body in motion as a foundation for designing interactive systems. Based on the theoretical foundation for Kinesthetic Interaction, a conceptual framework is introduced...... to reveal bodily potential in relation to three design themes – kinesthetic development, kinesthetic means and kinesthetic disorder; and seven design parameters – engagement, sociality, movability, explicit motivation, implicit motivation, expressive meaning and kinesthetic empathy. The framework is...

  15. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2012-01-01

    Ready to create rich interactive experiences with your artwork, designs, or prototypes? This is the ideal place to start. With this hands-on guide, you'll explore several themes in interactive art and design-including 3D graphics, sound, physical interaction, computer vision, and geolocation-and learn the basic programming and electronics concepts you need to implement them. No previous experience is necessary. You'll get a complete introduction to three free tools created specifically for artists and designers: the Processing programming language, the Arduino microcontroller, and the openFr

  16. Interacting parasites

    Science.gov (United States)

    Lafferty, Kevin D.

    2010-01-01

    Parasitism is the most popular life-style on Earth, and many vertebrates host more than one kind of parasite at a time. A common assumption is that parasite species rarely interact, because they often exploit different tissues in a host, and this use of discrete resources limits competition (1). On page 243 of this issue, however, Telfer et al. (2) provide a convincing case of a highly interactive parasite community in voles, and show how infection with one parasite can affect susceptibility to others. If some human parasites are equally interactive, our current, disease-by-disease approach to modeling and treating infectious diseases is inadequate (3).

  17. Vorticity-based correction for modelling of free-surface wave interacting with turbulent current

    Science.gov (United States)

    Zhang, Wei

    2014-11-01

    This paper describes a new vorticity-based correction model for studying the interaction between free-surface wave and turbulent current. To track free-surface movements, the volume of fluid (VOF) method is employed. The momentum equations are rewritten to avoid the numerically generated vorticity effects along the air-water interface. Simultaneously unsteady RANS equations are used, while standard k-epsilon model is adapted with modification to the production term by introducing the vorticity to limit the production of turbulent kinematic energy at free surface. To validate the numerical model used here, standalone wave and current cases are studied to ensure the accuracy of each component of the numerical model. The model is then used to simulate the interaction between the second-order stokes wave and turbulent current for both wave following and countering in a setting of shallow water wave flume. The results are compared with experimental measurement available in the literature.

  18. Embarrassing Interactions

    DEFF Research Database (Denmark)

    Deterding, Sebastian; Lucero, Andrés; Holopainen, Jussi;

    2015-01-01

    Wherever the rapid evolution of interactive technologies disrupts standing situational norms, creates new, often unclear situational audiences, or crosses cultural boundaries, embarrassment is likely. This makes embarrassment a fundamental adoption and engagement hurdle, but also a creative design...

  19. Interactive governance

    DEFF Research Database (Denmark)

    Sørensen, Eva; Torfing, Jacob; Peters, B. Guy;

    Governance has become one of the most commonly used concepts in contemporary political science. It is, however, often used to mean a variety of different things. This book helps to clarify this conceptual muddle by concentrating on one variety of governance-interactive governance. The authors argue...... that although the state may remain important for many aspects of governing, interactions between state and society represent an important, and perhaps increasingly important, dimension of governance. These interactions may be with social actors such as networks, with market actors or with other...... governments, but all these forms represent means of governing involving mixtures of state action with the actions of other entities.This book explores thoroughly this meaning of governance, and links it to broader questions of governance. In the process of explicating this dimension of governance the authors...

  20. Programming Interactivity

    CERN Document Server

    Noble, Joshua

    2009-01-01

    Make cool stuff. If you're a designer or artist without a lot of programming experience, this book will teach you to work with 2D and 3D graphics, sound, physical interaction, and electronic circuitry to create all sorts of interesting and compelling experiences -- online and off. Programming Interactivity explains programming and electrical engineering basics, and introduces three freely available tools created specifically for artists and designers: Processing, a Java-based programming language and environment for building projects on the desktop, Web, or mobile phonesArduino, a system t

  1. Project Increase of infrastructure: 'Establishment of a laboratory for studies of pollutants in air, water and soil through atomic and nuclear techniques; Proyecto Incremento de infraestructura: 'Establecimiento de un laboratorio para estudios de contaminantes en aire, agua y suelo mediante tecnicas atomicas y nucleares'

    Energy Technology Data Exchange (ETDEWEB)

    Aldape U, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1993-10-15

    In this report there are the guidelines of this project as well as the goals, activities and costs. The general objectives were: 1. A laboratory that allows to analyze with efficiency samples of air, water and soil pollutants using atomic and nuclear origin techniques as PIXE (Proton Induced X-ray Emission, NRA (Nuclear Reaction Analysis) and RBS (Rutherford Backscattering) as well as auxiliary and/or complementary techniques. 2. To obtain indicators of the influence of the pollution of the Valley of Mexico about the ecology and the health of the inhabitants of Mexico City with perspectives of carrying out studies in other cities. 3. To develop an appropriate technology for the realization of those studies and to generate human resources in this area. (Author)

  2. Interactive Storytelling

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik; Reng, Lars

    2015-01-01

    This book constitutes the refereed proceedings of the 8th International Conference on Interactive Digital Storytelling, ICIDS 2015, held in Copenhagen, Denmark, in November/December 2015. The 18 revised full papers and 13 short papers presented together with 9 posters, 9 workshop descriptions...

  3. Interactive Astronomy.

    Science.gov (United States)

    Martin, Jean K.

    1997-01-01

    Presents guiding principles for developing interactive lessons for the World Wide Web. Describes "Amazing Space: Education Online from the Hubble Space Telescope", a program where students study spectacular Hubble Space Telescope images of stars and star-forming regions to learn about the life cycle of stars and the creation of atoms. (JRH)

  4. Hadron interactions

    International Nuclear Information System (INIS)

    The proceedings contain invited lectures and papers presente at the symposium. Attention was devoted to hadron interactions a high energy in QCD, to the structure and decay of hadrons, the production of hadrons and supersymmetric particles in e+e- and ep collisions, to perturbation theory in quantum field theory, and new supersymmetric extensions of relativistic algebra. (Z.J

  5. Surface Mechanical and Rheological Behaviors of Biocompatible Poly((D,L-lactic acid-ran-glycolic acid)-block-ethylene glycol) (PLGA-PEG) and Poly((D,L-lactic acid-ran-glycolic acid-ran-ε-caprolactone)-block-ethylene glycol) (PLGACL-PEG) Block Copolymers at the Air-Water Interface.

    Science.gov (United States)

    Kim, Hyun Chang; Lee, Hoyoung; Khetan, Jawahar; Won, You-Yeon

    2015-12-29

    Air-water interfacial monolayers of poly((D,L-lactic acid-ran-glycolic acid)-block-ethylene glycol) (PLGA-PEG) exhibit an exponential increase in surface pressure under high monolayer compression. In order to understand the molecular origin of this behavior, a combined experimental and theoretical investigation (including surface pressure-area isotherm, X-ray reflectivity (XR) and interfacial rheological measurements, and a self-consistent field (SCF) theoretical analysis) was performed on air-water monolayers formed by a PLGA-PEG diblock copolymer and also by a nonglassy analogue of this diblock copolymer, poly((D,L-lactic acid-ran-glycolic acid-ran-caprolactone)-block-ethylene glycol) (PLGACL-PEG). The combined results of this study show that the two mechanisms, i.e., the glass transition of the collapsed PLGA film and the lateral repulsion of the PEG brush chains that occur simultaneously under lateral compression of the monolayer, are both responsible for the observed PLGA-PEG isotherm behavior. Upon cessation of compression, the high surface pressure of the PLGA-PEG monolayer typically relaxes over time with a stretched exponential decay, suggesting that in this diblock copolymer situation, the hydrophobic domain formed by the PLGA blocks undergoes glass transition in the high lateral compression state, analogously to the PLGA homopolymer monolayer. In the high PEG grafting density regime, the contribution of the PEG brush chains to the high monolayer surface pressure is significantly lower than what is predicted by the SCF model because of the many-body attraction among PEG segments (referred to in the literature as the "n-cluster" effects). The end-grafted PEG chains were found to be protein resistant even under the influence of the "n-cluster" effects.

  6. Binding of the Cationic Peptide (KL)4K to Lipid Monolayers at the Air-Water Interface: Effect of Lipid Headgroup Charge, Acyl Chain Length, and Acyl Chain Saturation.

    Science.gov (United States)

    Hädicke, André; Blume, Alfred

    2016-04-28

    The binding of the cationic peptide (KL)4K to monolayers of different anionic lipids was determined by adsorption experiments. The chemical structure of the anionic phospholipids was changed in different ways. First, the hydrophobic region of phosphatidylglycerols was altered by elongation of the acyl chain length. Second, an unsaturated chain was introduced. Third, lipids with negatively charged headgroups of different chemical structure were compared. (KL)4K itself shows no surface activity and does not bind to monolayers of zwitterionic lipids. Analysis of (KL)4K binding to anionic lipid monolayers reveals a competition between two binding processes: (i) incorporation of the peptide into the acyl chain region (surface pressure increase) and (ii) electrostatic interaction screening the negative charges with reduction of charge repulsion (surface pressure decrease due to monolayer condensation). The lipid acyl chain length and the chemical structure of the headgroup have minor effects on the binding properties. However, a strong dependence on the phase state of the monolayer was observed. In the liquid-expanded (LE) phase, the fluid monolayer provides enough space, so that peptide insertion due to hydrophobic interactions dominates. For monolayers in the liquid-condensed (LC) phase, peptide binding followed by monolayer condensation is the main effect. PMID:27049846

  7. Weak interactions

    International Nuclear Information System (INIS)

    These lectures are an introduction to the standard weak-electromagnetic gauge model and its experimental tests, followed by six-quark phenomenology and some Grand Unification schemes dealt with under the headings; charged-current fermi interaction, gauge theories, tests of the Salam-Weinberg model, natural flavour-conservation neutral current, triangle anomalies, more gauge fields, more quarks and leptons, grand unification, economy of parameters. 54 reference. (UK)

  8. Interactive Television: How Interactive is It?

    Science.gov (United States)

    Barty, Karin

    1998-01-01

    Discusses how interaction occurs with interactive television in the classroom, examining the introduction of interactive television into Victoria, Australia's schools and investigating two types of interaction (overt and covert) between students and teachers. Notes that the types of interaction that occur with interactive television relate to the…

  9. Infrared reflection-absorption spectroscopy: principles and applications to lipid-protein interaction in Langmuir films.

    Science.gov (United States)

    Mendelsohn, Richard; Mao, Guangru; Flach, Carol R

    2010-04-01

    Infrared reflection-absorption spectroscopy (IRRAS) of lipid/protein monolayer films in situ at the air/water interface provides unique molecular structure and orientation information from the film constituents. The technique is thus well suited for studies of lipid/protein interaction in a physiologically relevant environment. Initially, the nature of the IRRAS experiment is described and the molecular structure information that may be obtained is recapitulated. Subsequently, several types of applications, including the determination of lipid chain conformation and tilt as well as elucidation of protein secondary structure are reviewed. The current article attempts to provide the reader with an understanding of the current capabilities of IRRAS instrumentation and the type of results that have been achieved to date from IRRAS studies of lipids, proteins, and lipid/protein films of progressively increasing complexity. Finally, possible extensions of the technology are briefly considered. PMID:20004639

  10. Electroweak interactions

    CERN Document Server

    Maiani, Luciano

    2016-01-01

    Written by one of the world's leading experts on particle physics and the standard model―an award-winning former director general of CERN―this book provides an up-to-date account of electroweak interactions. Part of a series describing the formal, physical, and phenomenological aspects of the standard model of particle physics, the text introduces the mathematical concepts and applications of symmetry principles to particle physics, from the isotopic spin symmetry to the Eightfold Way and the Yang-Mills theories.

  11. Interactive Workspaces

    DEFF Research Database (Denmark)

    Mogensen, Preben Holst

    augmented reality, interactive building elements, and mobile devices to support new ways of working in a diversity of application domains with work situations ranging from individual work, through local collaboration, to distributed collaboration. The work situations may take place in offices/project rooms......Many application domains such as architecture, engineering, industrial design, city planning, environmental supervision, health care etc. share the properties of users working collaboratively with complex mixtures of physical and digital materials. Studies in such domains show that it is hard...

  12. Electromagnetic interactions

    CERN Document Server

    Bosanac, Slobodan Danko

    2016-01-01

    This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.

  13. Designing "Interaction": How Do Interaction Design Students Address Interaction?

    Science.gov (United States)

    Karlgren, Klas; Ramberg, Robert; Artman, Henrik

    2016-01-01

    Interaction design is usually described as being concerned with interactions with and through artifacts but independent of a specific implementation. Design work has been characterized as a conversation between the designer and the situation and this conversation poses a particular challenge for interaction design as interactions can be elusive…

  14. Interactions of Lipidic Cubic Phase Nanoparticles with Lipid Membranes.

    Science.gov (United States)

    Jabłonowska, Elżbieta; Nazaruk, Ewa; Matyszewska, Dorota; Speziale, Chiara; Mezzenga, Raffaele; Landau, Ehud M; Bilewicz, Renata

    2016-09-20

    The interactions of liquid-crystalline monoolein (GMO) cubic phase nanoparticles with various model lipid membranes spread at the air-solution interface by the Langmuir technique were investigated. Cubosomes have attracted attention as potential biocompatible drug delivery systems, and thus understanding their mode of interaction with membranes is of special interest. Cubosomes spreading at the air-water interface as well as interactions with a monolayer of 1, 2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) compressed to different surface pressures were studied by monitoring surface pressure-time dependencies at constant area. Progressive incorporation of the nanoparticles was shown to lead to mixed monolayer formation. The concentration of cubosomes influenced the mechanism of incorporation, as well as the fluidity and permeability of the resulting lipid membranes. Brewster angle microscopy images reflected the dependence of the monolayer structure on the cubosomes presence in the subphase. A parameter Csat was introduced to indicate the point of saturation of the lipid membrane with the cubosomal material. This parameter was found to depend on the surface pressure showing that the cubosomes disintegrate in prolonged contact with the membrane, filling available voids in the lipid membrane. At highest surface pressures when the layer is most compact, the penetration of cubosomal material is not possible and only some exchange with the membrane lipid becomes the route of including GMO into the layer. Finally, comparative studies of the interactions between lipids with various headgroup charges with cubosomes suggest that at high surface pressure an exchange of lipid component between the monolayer and the cubosome in its intact form may occur.

  15. 高寒地区某站房太阳能-空气/水源热泵联合供暖系统研究%The Application of Solar Energy and Air/Water Source Heat Pump Combined Heating System in the Railway Station Plateau Cold Area

    Institute of Scientific and Technical Information of China (English)

    李雨潇; 冯炼; 袁艳平

    2016-01-01

    The simulated calculation model are established for the solar energy and air/water source heat pump combined heating system based on TRNSYS, which use double evaporator heat pump and set up double water tank. Makes studys on operating characteristics of the system based on typical days and single and double tanks two conditions. The results indicate that this system has high solar assurance, and the use of double tanks can be improved the total quantity of heat, especially for the immediate tank heating quantity.%利用TRNSYS软件建立了高寒地区某站房太阳能-空气/水源热泵联合供暖系统仿真模型,该系统设置双蒸发器和双水箱。通过对典型天工况和单双水箱工况下应用性能的研究,其结果表明,该系统具有较高的太阳能保证率,双水箱的使用可增加水箱的总供热量,并且对水箱直接供热量有明显提升。

  16. Environmental Nanoparticles Interactions with Plants: Morphological, Physiological, and Genotoxic Aspects

    Directory of Open Access Journals (Sweden)

    C. Remédios

    2012-01-01

    Full Text Available Nanoparticles (NPs are characterized by their small size (less than 100 nm and large surface area, which confer specific physicochemical properties as strength, electrical, and optical features. NPs can be derived from natural or anthropic sources, such as engineered or unwanted/incidental NPs. The composition, dimension, and morphology of engineered NPs enable their use in a variety of areas, such as electronic, biomedical, pharmaceutical, cosmetic, energy, environmental, catalysis, and materials science. As nanotechnology is an innovative and scientific growth area with an exponential production, more information is needed concerning the impacts of these nanomaterials (NMs in the environment and, particularly, in animals/humans health and in plants performance. So, research on NPs as emerging contaminants is therefore a new field in environmental health. This minireview describes, briefly, the NPs characterization and their occurrence in the environment stating air, water, and soil. Finally, particular emphasis is given to the interaction of NPs with plants at different levels: morphology, physiology, and genotoxicity. By analyzing this compiled information, it is evident that research on NPs phytotoxicity is in the beginning, and more comprehensive studies are needed not only on NPs cytotoxicity and genotoxicity but also on the best and the most reliable methods of assessing NPs toxicity.

  17. Unification of Electromagnetic Interactions and Gravitational Interactions

    Institute of Scientific and Technical Information of China (English)

    WUNing

    2002-01-01

    Unified theory of gravitational interactions and electromagnetic interactions is discussed in this paper.Based on gauge principle,electromagnetic interactions and gravitational interactions are formulated in the same manner and are unified in a semi-direct product group of U(1) Abelian gauge group and gravitational gauge group.

  18. Unification of Electromagnetic Interactions and Gravitational Interactions

    Institute of Scientific and Technical Information of China (English)

    WU Ning

    2002-01-01

    Unified theory of gravitational interactions and electromagnetic interactions is discussed in this paper.Based on gauge principle, electromagnetic interactions and gravitational interactions are formulated in the same mannerand are unified in a semi-direct product group of U(1) Abelian gauge group and gravitational gauge group.

  19. Visible Light Responsive Catalyst for Air Water Purification Project

    Science.gov (United States)

    Wheeler, Raymond M.

    2014-01-01

    Investigate and develop viable approaches to render the normally UV-activated TIO2 catalyst visible light responsive (VLR) and achieve high and sustaining catalytic activity under the visible region of the solar spectrum.

  20. Severe Slugging in Air-Water Hybrid Riser System

    OpenAIRE

    Gong, Jing; Yang, Zhiyuan; Ma, Liang; Ping WANG

    2014-01-01

    In the subsea pipeline gathering system, severe slugging flow is prone to occur. Severe slugging flow brings major threat to production and flow assurance in oil and gas industry due to periodical pressure oscillation and large liquid volume. Currently many researchers pay much more attention on L-shaped riser, catenaries, and S-shaped riser; little research has been made on hybrid riser, which is applied in the Africa West and Gulf of Mexico oil fields. Flow characteristics simulation for hy...

  1. Global climate change will affect air, water in California

    OpenAIRE

    WEARE, BRYAN C.

    2002-01-01

    As we enter the 21st century, it is possible to reach beyond the headlines to describe what is now known about climate change. The Intergovernmental Panel on Climate Change evaluated the scientific aspects of global climate change; the current consensus is described in a recent series of reports. Since the 19th century, concentrations of atmospheric carbon dioxide, methane, nitrous oxide and sulfate aerosol dust have increased significantly. While there is scientific agreement that warming is...

  2. New research on bioregenerative air/water purification systems

    Science.gov (United States)

    Johnson, Anne H.; Ellender, R. D.; Watkins, Paul J.

    1991-01-01

    For the past several years, air and water purification systems have been developed and used. This technology is based on the combined activities of plants and microorganisms as they function in a natural environment. More recently, researchers have begun to address the problems associated with indoor air pollution. Various common houseplants are currently being evaluated for their abilities to reduce concentrations of volatile organic compounds (VOCS) such as formaldehyde and benzene. With development of the Space Exploration Initiative, missions will increase in duration, and problems with resupply necessitates implementation of regenerative technology. Aspects of bioregenerative technology have been included in a habitat known as the BioHome. The ultimate goal is to use this technology in conjunction with physicochemical systems for air and water purification within closed systems. This study continued the risk assessment of bioregenerative technology with emphasis on biological hazards. In an effort to evaluate the risk for human infection, analyses were directed at enumeration of fecal streptococci and enteric viruses with the BioHome waste water treatment system.

  3. Ozonolysis of Uric Acid at the Air/Water Interface

    OpenAIRE

    Enami, Shinichi; Hoffmann, M. R.; Colussi, A. J.

    2008-01-01

    Uric acid (UA) epoxide, peroxide, and ozonide species produced in aqueous UA microdroplets exposed to O3(g) are detected by online mass spectrometry within ∼1 ms. UA conversions are independent of its initial concentration below ∼0.1 mM and are unaffected by addition of excess H2O2 or t-butanol. UA reactivity increases ∼380 times from pH 4 to 7, which is at variance with the pH-independent rates reported for the UA + O3(aq) reaction in bulk water. At pH ∼7, UA and ascorbic acid (AH2) microdro...

  4. Ascorbyl palmitate interaction with phospholipid monolayers: electrostatic and rheological preponderancy.

    Science.gov (United States)

    Mottola, Milagro; Wilke, Natalia; Benedini, Luciano; Oliveira, Rafael Gustavo; Fanani, Maria Laura

    2013-11-01

    Ascorbyl palmitate (ASC16) is an anionic amphiphilic molecule of pharmacological interest due to its antioxidant properties. We found that ASC16 strongly interacted with model membranes. ASC16 penetrated phospholipid monolayers, with a cutoff near the theoretical surface pressure limit. The presence of a lipid film at the interface favored ASC16 insertion compared with a bare air/water surface. The adsorption and penetration time curves showed a biphasic behavior: the first rapid peak evidenced a fast adsorption of charged ASC16 molecules to the interface that promoted a lowering of surface pH, thus partially neutralizing and compacting the film. The second rise represented an approach to the equilibrium between the ASC16 molecules in the subphase and the surface monolayer, whose kinetics depended on the ionization state of the film. Based on the Langmuir dimiristoylphosphatidylcholine+ASC16 monolayer data, we estimated an ASC16 partition coefficient to dimiristoylphosphatidylcholine monolayers of 1.5×10(5) and a ΔGp=-6.7kcal·mol(-1). The rheological properties of the host membrane were determinant for ASC16 penetration kinetics: a fluid membrane, as provided by cholesterol, disrupted the liquid-condensed ASC16-enriched domains and favored ASC16 penetration. Subphase pH conditions affected ASC16 aggregation in bulk: the smaller structures at acidic pHs showed a faster equilibrium with the surface film than large lamellar ones. Our results revealed that the ASC16 interaction with model membranes has a highly complex regulation. The polymorphism in the ASC16 bulk aggregation added complexity to the equilibrium between the surface and subphase form of ASC16, whose understanding may shed light on the pharmacological function of this drug. PMID:23806650

  5. Drug Interaction API

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Interaction API is a web service for accessing drug-drug interactions. No license is needed to use the Interaction API. Currently, the API uses DrugBank for its...

  6. Interaction for visualization

    CERN Document Server

    Tominski, Christian

    2015-01-01

    Visualization has become a valuable means for data exploration and analysis. Interactive visualization combines expressive graphical representations and effective user interaction. Although interaction is an important component of visualization approaches, much of the visualization literature tends to pay more attention to the graphical representation than to interaction.The goal of this work is to strengthen the interaction side of visualization. Based on a brief review of general aspects of interaction, we develop an interaction-oriented view on visualization. This view comprises five key as

  7. Bending of the Flexible Spacer Chain of Gemini Surfactant Induced by Hydrophobic Interaction

    Institute of Scientific and Technical Information of China (English)

    YOU,Yi; JIANG,Rong; LING,Tingting; ZHAO,Jianxi

    2009-01-01

    In order to understand the special role of the flexible alkylene spacer of gemini surfactant in the self-assembly,three gemini surfactants,alkylene-α,ω-bis(didodecylmethylammonium bromide)that is designated as 2C12-s-2C12·2Br (s=3,6,8),were synthesized.When the spread films of 2C12-s-2C12·2Br on the surface of water were con-structed,they form the dense layer of the alkyl tails owing to four dodecyl chains per molecule.This induced the bending of the spacer chain toward the air-side at the s smaller than that of C12-s-C12·2Br adsorbed on the air/water interface owing to the enhanced hydrophobic interaction between the alkyl tails and the spacer chain, where C12-s-C12·2Br has only two alkyl tails per molecule. Conclusively.,the enhanced hydrophobic interaction between the alkyl tails and the spacer chain can effectively induce the bending of the latter toward the air-side.

  8. Interactive pinball business

    DEFF Research Database (Denmark)

    Buur, Jacob; Gudiksen, Sune Klok

    2012-01-01

    Interaction design expands into new fields. Interaction design and business model innovation is a promising meeting of disciplines: Many businesses see the need to rethink their ways of doing business, and, as business models pose highly dynamic and interactive problems, interaction design has much...... to offer. This paper compares 'tangible business models' in the form of pinball-like contraptions, designed by interaction design students with those developed by groups of professionals around concrete business issues. We will show how the interactive models encourage business people to play...... with hypotheses and experiment with scenarios as a way of innovating their business models, and why this is so...

  9. Interactive Pinball Business

    DEFF Research Database (Denmark)

    Buur, Jacob; Gudiksen, Sune

    2012-01-01

    Interaction design expands into new fields. Interaction design and business model innovation is a promising meeting of disciplines: Many businesses see the need to rethink their ways of doing business, and, as business models pose highly dynamic and interactive problems, interaction design has much...... to offer. This paper compares ‘tangible business models’ in the form of pinball-like contraptions, designed by interaction design students with those developed by groups of professionals around concrete business issues. We will show how the interactive models encourage business people to play...... with hypotheses and experiment with scenarios as a way of innovating their business models, and why this is so....

  10. Interacting dark sector with transversal interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chimento, Luis P.; Richarte, Martín G. [Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Pabellón I, Buenos Aires 1428 (Argentina)

    2015-03-26

    We investigate the interacting dark sector composed of dark matter, dark energy, and dark radiation for a spatially flat Friedmann-Robertson-Walker (FRW) background by introducing a three-dimensional internal space spanned by the interaction vector Q and solve the source equation for a linear transversal interaction. Then, we explore a realistic model with dark matter coupled to a scalar field plus a decoupled radiation term, analyze the amount of dark energy in the radiation era and find that our model is consistent with the recent measurements of cosmic microwave background anisotropy coming from Planck along with the future constraints achievable by CMBPol experiment.

  11. Interacting agents in finance

    NARCIS (Netherlands)

    C. Hommes

    2008-01-01

    Interacting agents in finance represent a behavioural, agent-based approach in which financial markets are viewed as complex adaptive systems consisting of many boundedly rational agents interacting through simple heterogeneous investment strategies, constantly adapting their behaviour in response t

  12. Overview of interactive visualization

    NARCIS (Netherlands)

    E.V. Zudilova-Seinstra; T. Adriaansen; R. van Liere

    2009-01-01

    The chapter introduces fundamentals of Interactive Visualization, surveys research in the field, examines existing challenges and provides information about popular frameworks that can be used for the development of interactive data visualizations.

  13. Health Data Interactive (HDI)

    Data.gov (United States)

    U.S. Department of Health & Human Services — Health Data Interactive (HDI) presents a broad range of important public health indicators through an interactive web-based application that provides access to...

  14. Sea Turtle Interaction Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Sea Turtle Interaction Report is a report sent out in pdf format to authorized individuals that summarizes sea turtle interactions in the longline fishery. The...

  15. Gestalt Interactional Groups

    Science.gov (United States)

    Harman, Robert L.; Franklin, Richard W.

    1975-01-01

    Gestalt therapy in groups is not limited to individual work in the presence of an audience. Describes several ways to involve gestalt groups interactionally. Interactions described focus on learning by doing and discovering, and are noninterpretive. (Author/EJT)

  16. Plasma-wall interaction; Interaction plasma paroi

    Energy Technology Data Exchange (ETDEWEB)

    Reichle, R

    2004-07-01

    This document gathers the 43 slides presented in the framework of the week long lecture 'hot plasmas 2004' and dedicated to plasma-wall interaction in a tokamak. This document is divided into 4 parts: 1) thermal load on the wall, power extraction and particle recovery, 2) basic edge plasma physics, 3) processes that drive the plasma-solid interaction, and 4) material conditioning (surface treatment...) for ITER.

  17. Compton effect: interacting particles or interacting waves

    CERN Document Server

    Hernández, O F

    2005-01-01

    Traditional textbook explanations of the Compton effect treat the photon electron interaction as a particle collision. This explanation is a pedagogical disaster, implying that sometimes interactions are particle-like whereas quantum mechanics always demands that they be wave-like; a photon wavefunction evolves according to a wave equation until its collapse at measurement. If this is so why then does the classical radiation wave equation fail to predict the Compton effect? We address these issues and propose a clearer explanation.

  18. Patient - patient interaction

    DEFF Research Database (Denmark)

    Birkelund, Regner; Søndergaard Larsen, Lene

    2013-01-01

    , but occasionally, the opposite was experienced too. Less typically, the patients experienced interaction with fellow patients as a burden and referred to it in negative terms. Conclusions:  Patients’ interaction resembled care as well as self-care. Patient–patient interaction was an important part of the social...

  19. Gaze Interactive Building Instructions

    DEFF Research Database (Denmark)

    Hansen, John Paulin; Ahmed, Zaheer; Mardanbeigi, Diako

    We combine eye tracking technology and mobile tablets to support hands-free interaction with digital building instructions. As a proof-of-concept we have developed a small interactive 3D environment where one can interact with digital blocks by gaze, keystroke and head gestures. Blocks may be moved...

  20. Interaction and Language Acquisition

    Institute of Scientific and Technical Information of China (English)

    孙红叶

    2016-01-01

    Based on Long's Interaction Hypothesis (IH), the paper examines the aspects of interaction that might facilitate natu-ralistic language development and goes further to propose features of interaction that could encourage classroom second lan-guage acquisition, in the hope that improved classroom interation will enhance teaching effectiveness in language classroom.

  1. Quintessence with Yukawa Interaction

    CERN Document Server

    Costa, André A; Abdalla, E

    2014-01-01

    We consider a quintessence model for dark energy interacting with dark matter via a Yukawa interaction. To put constraints on this model we use the CMB measurements from the Planck satellite together with BAO, SNIa and $H_0$ data. We conclude that this is a viable model and an appropriate scalar potential can favor the interacting scenario.

  2. Grasp interaction with tablets

    CERN Document Server

    Wolf, Katrin

    2015-01-01

    This book presents guidelines for a future device type: a tablet that allows ergonomic front- and back-of-device interaction. These guidelines help designers and developers of user interfaces to build ergonomic applications for tablet devices, in particular for devices that enable back-of-device interaction. In addition, manufacturers of tablet devices obtain arguments that back-of-device interaction is a promising extension of the interaction design space and results in increased input capabilities, enriched design possibilities, and proven usability. The guidelines are derived from empirical studies and developed to fit the users’ skills to the way the novel device type is held. Three particular research areas that are relevant to develop design guidelines for tablet interaction are investigated: ergonomic gestures, interaction areas, and pointing techniques.

  3. Multiphase fluid structure interaction in bends and T-joints

    NARCIS (Netherlands)

    Cargnelutti, M.F.; Belfroid, S.P.C.; Schiferli, W.; Osch, M.M.E. van

    2010-01-01

    Air-water experiments were carried out in a horizontal 1" pipe system to measure the magnitude of the forces induced by the multiphase flow. Forces and accelerations were measured on a number of bends and T-joint configurations for a wide range of operating conditions. Five different configurations

  4. Interactions in multispecies biofilms

    DEFF Research Database (Denmark)

    Burmølle, Mette; Ren, Dawei; Bjarnsholt, Thomas;

    2014-01-01

    The recent focus on complex bacterial communities has led to the recognition of interactions across species boundaries. This is particularly pronounced in multispecies biofilms, where synergistic interactions impact the bacterial distribution and overall biomass produced. Importantly, in a number...... of settings, the interactions in a multispecies biofilm affect its overall function, physiology, or surroundings, by resulting in enhanced resistance, virulence, or degradation of pollutants, which is of significant importance to human health and activities. The underlying mechanisms causing these synergistic...

  5. Quantum interaction. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Bruza, Peter [Queensland Univ. of Technology, Brisbane (Australia). Faculty of Science and Technology; Sofge, Donald [Navy Center for Applied Research in Artificial Intelligence, Washington, DC (United States). Naval Research Lab.; Lawless, William [Paine Coll., Augusta, GA (United States); Rijsbergen, Keith van [Glasgow Univ. (United Kingdom). Dept. of Computing Science; Klusch, Matthias (eds.) [German Research Center for Artificial Intelligence, Saarbruecken (Germany)

    2009-07-01

    This book constitutes the refereed proceedings of the Third International Symposium on Quantum Interaction, QI 2009, held in Saarbruecken, Germany, in March 2009. The 21 revised full papers presented together with the 3 position papers were carefully reviewed and selected from numerous submissions. The papers show the cross-disciplinary nature of quantum interaction covering topics such as computation, cognition, decision theory, information retrieval, information systems, social interaction, computational linguistics and finance. (orig.)

  6. Interactive Strategy-Making

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    2015-01-01

    to failed communication and execution of the planned actions. However, effective strategy-making comprises both central reasoning from forward-looking planning considerations and decentralised responses to emerging events as interacting elements in a dynamic adaptive system. The interaction between......This article outlines an interactive strategy-making model that combines central reasoning with ongoing learning from decentralised responses. The management literature often presents strategy as implementing an optimal plan identified through rational analysis and ascribes potential shortcomings...

  7. The Science of Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Pike, William A.; Stasko, John T.; Chang, Remco; O' Connell, Theresa

    2009-09-23

    There is a growing recognition with the visual analytics community that interaction and inquiry are inextricable. It is through the interactive manipulation of a visual interface – the analytic discourse – that knowledge is constructed, tested, refined, and shared. This paper reflects on the interaction challenges raised in the original visual analytics research and development agenda and further explores the relationship between interaction and cognition. It identifies recent exemplars of visual analytics research that have made substantive progress toward the goals of a true science of interaction, which must include theories and testable premises about the most appropriate mechanisms for human-information interaction. Six areas for further work are highlighted as those among the highest priorities for the next five years of visual analytics research: ubiquitous, embodied interaction; capturing user intentionality; knowledge-based interfaces; principles of design and perception; collaboration; and interoperability. Ultimately, the goal of a science of interaction is to support the visual analytics community through the recognition and implementation of best practices in the representation of and interaction with visual displays.

  8. Framing interactive methods

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard

    2011-01-01

    Two paradigms of organization and leadership is outlined and compared. A theoretical model of interactive leadership is developed, combining learning, knowledge flow, leadership and organizational principles....

  9. Vision-based interaction

    CERN Document Server

    Turk, Matthew

    2013-01-01

    In its early years, the field of computer vision was largely motivated by researchers seeking computational models of biological vision and solutions to practical problems in manufacturing, defense, and medicine. For the past two decades or so, there has been an increasing interest in computer vision as an input modality in the context of human-computer interaction. Such vision-based interaction can endow interactive systems with visual capabilities similar to those important to human-human interaction, in order to perceive non-verbal cues and incorporate this information in applications such

  10. Diachronic Perspective and Interaction

    DEFF Research Database (Denmark)

    Marchetti, Emanuela; Valente, Andrea

    . Although this interaction style may appeal to teachers, as it reminds of school teaching, it has several disadvantages: a dialogue never occurs between adults and children, who listen in silence, hence it becomes hard to evaluate what has being learnt and how deeply, and finally it is not very engaging....... Explorations of more interactive representations of the diachronic perspective, through play and tangible interaction, may foster a dialogue with young visitors. Therefore, a new interactive installation is being designed, intended as a tool to enrich learning, allowing children to experience historical...

  11. Interaction of a turbulent channel flow with a compliant tensegrity fabric

    Science.gov (United States)

    Luo, Haoxiang; Bewley, Thomas

    2004-11-01

    A non-trivial influence of the compliant surface on the statistics of near-wall turbulence has been found by direct numerical simulations of a channel flow at Re_τ=150 passing over a ``tensegrity fabric'' surface. Inspired from nature, this compliant surface model is special truss system having tensile members distinguished from the compressive members, as we have presented at previous APS meetings. Validated by a variety of flows, a pseudospectral/finite-difference flow solver with a 3D coordinate transformation is coupled with a C++ code calculating the dynamics of the tensegrity fabric to simulate the flow/structure interaction. Simulation results show that, when the structure has high stiffness and damping, the flow acts as if the interface were a solid flat wall. When the structure's stiffness and damping are reduced, it may resonate under the excitation of the flow disturbances. The resonating flow/structure interface forms a streamwise wave reminiscent of air-water interface but traveling at a much faster phase speed, a few times of the viscous velocity u_τ. Although the wave's amplitude is small, y_w^+≈ 2, it changes the near-wall turbulence significantly. Drag on the compliant surface is increased by about 17% where form drag accounts for only one third of the drag increase due to the small wall deformation. Various domain sizes have been tried in order to make sure that the structure's vibration mode is correct.

  12. Future Interaction Design II

    CERN Document Server

    Isomaki, Heikki M

    2009-01-01

    Argues that it is the human character rather than the technology that should determine the nature of interaction, and that the term 'interaction design' covers a range of issues relevant to enabling quality design. This book discusses a number of topics, such as psychological design processes, gerotechnology, modeling, and e-learning

  13. Media Facades beyond Interaction

    DEFF Research Database (Denmark)

    Fritsch, Jonas

    2008-01-01

    As part of a the research project Digital Urban Living [www.digitalurbanliving.dk], we have taken part in the design of two large-scale installations that employ interactive technologies to facilitate participation and foster social interactions in public, urban settings. We present the two cases...

  14. Visualizing Dispersion Interactions

    Science.gov (United States)

    Gottschalk, Elinor; Venkataraman, Bhawani

    2014-01-01

    An animation and accompanying activity has been developed to help students visualize how dispersion interactions arise. The animation uses the gecko's ability to walk on vertical surfaces to illustrate how dispersion interactions play a role in macroscale outcomes. Assessment of student learning reveals that students were able to develop…

  15. Electroweak interactions in nuclei

    International Nuclear Information System (INIS)

    Topics include: introduction to electroweak theory; the Weinberg-Salam theory for leptons; the Weinberg-Salam theory for hadrons-the GIM mechanism; electron scattering as a probe of the electroweak interaction (observation of PV, the weak interaction for nucleons, and parity violation in atoms); and time reversed invariance and electric dipole moments of nucleons, nuclei, and atoms. 52 references

  16. Sketches in Embodied Interaction

    DEFF Research Database (Denmark)

    Erkut, Cumhur; Dahl, Sofia; Triantafyllidis, Georgios

    2014-01-01

    We present an approach for teaching and designing embodied interaction based on interactive sketches. We have combined the mover perspective and felt experiences of movement with advanced technologies (multi-agents, physical simulations) in a generative design session. We report our activities an...

  17. Moving into an interaction

    DEFF Research Database (Denmark)

    Mortensen, Kristian; Hazel, Spencer

    2014-01-01

    Opening an interaction is a crucial step in establishing and maintaining social relationships. In this paper we describe how participants in an institutional setting, a help desk counter for exchange students at an international university, literally move into interaction. This is accomplished th...

  18. Philosophy of Interaction

    DEFF Research Database (Denmark)

    Svanæs, Dag

    2011-01-01

    This is an encyclopedia entry for the Interaction-Design.org free IxD encyclopedia. The topic of the entry is the application of the philosophy of Heidegger and Merleau-Ponty to a theory of interactivity. Comments by Don Norman and Eva Hornecker....

  19. Magnetic interactions between nanoparticles

    Directory of Open Access Journals (Sweden)

    Steen Mørup

    2010-12-01

    Full Text Available We present a short overview of the influence of inter-particle interactions on the properties of magnetic nanoparticles. Strong magnetic dipole interactions between ferromagnetic or ferrimagnetic particles, that would be superparamagnetic if isolated, can result in a collective state of nanoparticles. This collective state has many similarities to spin-glasses. In samples of aggregated magnetic nanoparticles, exchange interactions are often important and this can also lead to a strong suppression of superparamagnetic relaxation. The temperature dependence of the order parameter in samples of strongly interacting hematite nanoparticles or goethite grains is well described by a simple mean field model. Exchange interactions between nanoparticles with different orientations of the easy axes can also result in a rotation of the sub-lattice magnetization directions.

  20. Legacy Systems Interaction Reengineering

    Science.gov (United States)

    El-Ramly, Mohammad; Stroulia, Eleni; Samir, Hani

    We present a lightweight approach for reengineering the human computer interaction (HCI) and/or interaction with other software systems. While interaction reengineering can be achieved by changing the source code and design (e.g., library replacement, refactoring, etc.) resulting in a different user interface (UI), we limit the discussion to interaction reengineering methods that do not involve changing the source code or internal design of the system. Instead, we focus on methods and techniques for wrapping and packaging the existing interaction layer to reproduce it in a different format, e.g., on a different platform or to integrate the legacy system services in another application possibly under a different architecture paradigm, e.g., service-oriented architectures (SOA).

  1. Extrasolar Planet Interactions

    CERN Document Server

    Barnes, Rory

    2008-01-01

    The dynamical interactions of planetary systems may be a clue to their formation histories. Therefore, the distribution of these interactions provides important constraints on models of planet formation. We focus on each system's apsidal motion and proximity to dynamical instability. Although only ~25 multiple planet systems have been discovered to date, our analyses in these terms have revealed several important features of planetary interactions. 1) Many systems interact such that they are near the boundary between stability and instability. 2) Planets tend to form such that at least one planet's eccentricity periodically drops to near zero. 3) Mean-motion resonant pairs would be unstable if not for the resonance. 4) Scattering of approximately equal mass planets is unlikely to produce the observed distribution of apsidal behavior. 5) Resonant interactions may be identified through calculating a system's proximity to instability, regardless of knowledge of angles such as mean longitude and longitude of peri...

  2. Interaction English Teaching Model

    Institute of Scientific and Technical Information of China (English)

    穆宇娜

    2013-01-01

      Malash—Thomas pointed out“Interaction is a process in which people and things act upon each other through their ac⁃tions.”According to different subjects, interaction can be divided into human-computer interaction, people-people interaction and learner-content interaction. According to different forms, interactions can be divided into one-one interaction, one-more interac⁃tion and more-more interaction.“Interaction Education”means that teachers are leading parts and students are the center of class. During teaching process, teachers must lead students to discover. Demands from students can encourage teachers to inspire con⁃versely.Thus it can form a close communication between teachers and students. Teaching and learning are realized in a happy and harmonious atmosphere. Successful English teaching must take new bilateral teaching as the first part, which should let the func⁃tion of the two most important elements develop fully. Teachers should grasp opportunities to guide. Teaching methods need to be flexible, and contents of teaching need to be vivid;students should be keen to think, to participate actively, and can break the tradi⁃tion to produce fresh ideas, and in that situation the capability of students can develop fully. The educational model refers to the simplified description of detailed teaching activities. Possessing dual functions of theory and practice, the educational model is the manifestation of theoretical teaching method. The combination of interaction and educational model which are mentioned above form the“interactive teaching”model. With the coming of economic globalization and integration of science and technology, now communications are increasing with each passing day. If you want to take part in or to get in touch with others, you must use lan⁃guage. English has been learnt for 10 years in Middle school and in college, but it can’t be spoken very fluently. That is a realistic picture as the result of an

  3. Magnetic interactions between nanoparticles

    DEFF Research Database (Denmark)

    Mørup, Steen; Hansen, Mikkel Fougt; Frandsen, Cathrine

    2010-01-01

    We present a short overview of the influence of inter-particle interactions on the properties of magnetic nanoparticles. Strong magnetic dipole interactions between ferromagnetic or ferrimagnetic particles, that would be superparamagnetic if isolated, can result in a collective state of nanoparti......We present a short overview of the influence of inter-particle interactions on the properties of magnetic nanoparticles. Strong magnetic dipole interactions between ferromagnetic or ferrimagnetic particles, that would be superparamagnetic if isolated, can result in a collective state...... of nanoparticles. This collective state has many similarities to spin-glasses. In samples of aggregated magnetic nanoparticles, exchange interactions are often important and this can also lead to a strong suppression of superparamagnetic relaxation. The temperature dependence of the order parameter in samples...... of strongly interacting hematite nanoparticles or goethite grains is well described by a simple mean field model. Exchange interactions between nanoparticles with different orientations of the easy axes can also result in a rotation of the sub-lattice magnetization directions....

  4. Plasma-wall interactions

    International Nuclear Information System (INIS)

    The plasma wall interactions for two extreme cases, the 'vacuum model' and the 'cold gas blanket' are outlined. As a first step for understanding the plasma wall interactions the elementary interaction processes at the first wall are identified. These are energetic ion and neutral particle trapping and release, ion and neutral backscattering, ion sputtering, desorption by ions, photons and electrons and evaporation. These processes have only recently been started to be investigated in the parameter range of interest for fusion research. The few measured data and their extrapolation into regions not yet investigated are reviewed

  5. Interacting with virtual worlds

    Science.gov (United States)

    Zeltzer, David

    1991-01-01

    What tools should we provide the user for defining and interacting with objects and agents in virtual environments at varying levels of complexity? Understanding the appropriate simplifications to make is critical for modeling nontrivial environments and agents with varying levels of autonomy. I describe a set of abstraction mechanisms appropriate for constructing and interacting with virtual worlds, and I discuss how programming, and direct manipulation of guiding techniques, can be used to afford users interactive access to graphical simulations at appropriate levels of abstraction.

  6. INTERACT Station Catalogue - 2015

    DEFF Research Database (Denmark)

    INTERACT stations are located in all major environmental envelopes of the Arctic providing an ideal platform for studying climate change and its impact on the environment and local communities. Since alpine environments face similar changes and challenges as the Arctic, the INTERACT network also...... and research groups. Therefore, INTERACT has produced a catalogue of research stations including descriptions of the physical setting, facilities and services offered at the stations. It is our hope that this catalogue will help researchers identify research stations that suit their specific needs. The 2015...

  7. Dendrimer-surfactant interactions.

    Science.gov (United States)

    Cheng, Yiyun; Zhao, Libo; Li, Tianfu

    2014-04-28

    In this article, we reviewed the interactions between dendrimers and surfactants with particular focus on the interaction mechanisms and physicochemical properties of the yielding dendrimer-surfactant aggregates. In order to provide insight into the behavior of dendrimers in biological systems, the interactions of dendrimers with bio-surfactants such as phospholipids in bulk solutions, in solid-supported bilayers and at the interface of phases or solid-states were discussed. Applications of the dendrimer-surfactant aggregates as templates to guide the synthesis of nanoparticles and in drug or gene delivery were also mentioned.

  8. Tuning Polyelectrolyte-Surfactant Interactions: Modification of Poly(ethylenimine) with Propylene Oxide and Blocks of Ethylene Oxide.

    Science.gov (United States)

    Penfold, J; Thomas, R K; Li, P; Batchelor, S N; Tucker, I M; Burley, A W

    2016-02-01

    Significantly enhanced adsorption at the air-water interface arises in polyelectrolyte/ionic surfactant mixtures, such as poly(ethylenimine)/sodium dodecyl sulfate (PEI/SDS), down to relatively low surfactant concentrations due to a strong surface interaction between the polyelectrolyte and surfactant. In the region of charge neutralization this can result in precipitation or coacervation and give rise to undesirable properties in many applications. Ethoxylation of the PEI can avoid precipitation, but can also considerably weaken the interaction. Localization of the ethoxylation can overcome these shortcomings. Further manipulation of the polyelectrolyte-surfactant interaction can be achieved by selective ethoxylation and propoxylation of the PEI amine groups. Neutron reflectivity and surface tension data are presented here which show how the polyelectrolyte-surfactant interaction can be manipulated by tuning the PEI structure. Using deuterium labeled surfactant and polymer the neutron reflectivity measurements provide details of the surface composition and structure of the adsorbed layer. The general pattern of behavior is that at low surfactant concentrations there is enhanced surfactant adsorption due to the strong surface interaction; whereas around the region of the SDS critical micellar concentration, cmc, the surface is partially depleted of surfactant in favor bulk aggregate structures. The results presented here show how these characteristic features of the adsorption are affected by the degree of ethoxylation and propoxylation. Increasing the degree of propoxylation enhances the surfactant adsorption, whereas varying the degree of ethoxylation has a less pronounced effect. In the region of surfactant surface depletion increasing both the degree of ethoxylation and propoxylation result in an increased surface depletion. PMID:26757099

  9. Interactive Energy Planning

    DEFF Research Database (Denmark)

    Blarke, Morten Boje

    2006-01-01

    anchoring along the shores of the land of communications and collaboration. Whether or not a particular typology is applicable, theory and praxis are establishing standpoints, which strengthens our understanding of the planning complex, and which should inspire improved energy planning methodologies...... and tools. This paper presents an “Interactive Energy Planning” framework, which is intended to support interactivity in planning, building on important theoretical and experimental advances in planning. In particular, the paper explores the potential significance of allowing a critical perspective...... on context analysis and problem-orientation to define the course of the planning process, and deploying value-rational planning tools primarily as a platform for interactivity. The focus on interactivity in energy planning will allow contemporary government planners, consultants, researchers...

  10. Theory of gravitational interactions

    CERN Document Server

    Gasperini, Maurizio

    2013-01-01

    This reference textbook is an up-to-date and self-contained introduction to the theory of gravitational interactions. The first part of the book follows the traditional presentation of general relativity as a geometric theory of the macroscopic gravitational field. A second, advanced part then discusses the deep analogies (and differences) between a geometric theory of gravity and the gauge theories of the other fundamental interactions. This fills a gap which is present in the context of the traditional approach to general relativity, and which usually makes students puzzled about the role of gravity. The necessary notions of differential geometry are reduced to the minimum, leaving more room for those aspects of gravitational physics of current phenomenological and theoretical interest, such as the properties of gravitational waves, the gravitational interactions of spinors, and the supersymmetric and higher-dimensional generalization of the Einstein equations. Theory of Gravitational Interactions will be o...

  11. Elementary particle interactions

    International Nuclear Information System (INIS)

    Work continues on strange particle production in weak interactions using data from a high-energy neutrino exposure in a freon bubble chamber. Meson photoproduction has also consumed considerable effort. Detector research and development activities have been carried out

  12. ENTREPRENEURSHIP AS SOCIAL INTERACTION

    DEFF Research Database (Denmark)

    Larsen, Henry; Lima, Patricia; Olsen, Bente;

    2013-01-01

    This paper aims to explore how entrepreneurs work with innovation; to explore and develop attention points in understanding entrepreneurship as social processes of interaction between people. Through interviews and engagement with entrepreneurs and key stakeholders, their actual social practices...

  13. Interactive Office user's manual

    Science.gov (United States)

    Montgomery, Edward E.; Lowers, Benjamin; Nabors, Terri L.

    1990-01-01

    Given here is a user's manual for Interactive Office (IO), an executive office tool for organization and planning, written specifically for Macintosh. IO is a paperless management tool to automate a related group of individuals into one productive system.

  14. Atomic and Molecular Interactions

    International Nuclear Information System (INIS)

    The Gordon Research Conference (GRC) on Atomic and Molecular Interactions was held at Roger Williams University, Bristol, RI. Emphasis was placed on current unpublished research and discussion of the future target areas in this field

  15. Unparticle self-interactions

    CERN Document Server

    Georgi, Howard

    2009-01-01

    We develop techniques for studying the effects of self-interactions in the conformal sector of an unparticle model. Their physics is encoded in the higher n-point functions of the conformal theory. We study inclusive processes and argue that the inclusive production of unparticle stuff in standard model processes due to the unparticle self-interactions can be decomposed using the conformal partial wave expansion and its generalizations into a sum over contributions from the production of various kinds of unparticle stuff, corresponding to different primary conformal operators. Such processes typically involve the production of unparticle stuff associated with operators other than those to which the standard model couples directly. Thus just as interactions between particles allow scattering processes to produce new particles in the final state, so unparticle self-interactions cause the production of various kinds of unparticle stuff. We discuss both inclusive and exclusive methods for computing these processe...

  16. Human Work Interaction Design

    DEFF Research Database (Denmark)

    Lopes, Arminda; Ørngreen, Rikke

    This book constitutes the thoroughly refereed post-conference proceedings of the Third IFIP WG 13.6 Working Conference on Human Work Interaction Design, HWID 2012, held in Copenhagen, Denmark, in December 2012. The 16 revised papers presented were carefully selected for inclusion in this volume. ......, and mobile probing. They have been organized in the following topical sections: work analysis: dimensions and methods; interactions, models and approaches; and evaluations, interactions and applications........ The papers reflect many different areas and address many complex and diverse work domains, ranging from medical user interfaces, work and speech interactions at elderly care facilities, greenhouse climate control, navigating through large oil industry engineering models, crisis management, library usability...

  17. Chasing Ecological Interactions

    Science.gov (United States)

    2016-01-01

    Basic research on biodiversity has concentrated on individual species—naming new species, studying distribution patterns, and analyzing their evolutionary relationships. Yet biodiversity is more than a collection of individual species; it is the combination of biological entities and processes that support life on Earth. To understand biodiversity we must catalog it, but we must also assess the ways species interact with other species to provide functional support for the Tree of Life. Ecological interactions may be lost well before the species involved in those interactions go extinct; their ecological functions disappear even though they remain. Here, I address the challenges in studying the functional aspects of species interactions and how basic research is helping us address the fast-paced extinction of species due to human activities. PMID:27631692

  18. Interactive Topology Optimization

    DEFF Research Database (Denmark)

    Nobel-Jørgensen, Morten

    Interactivity is the continuous interaction between the user and the application to solve a task. Topology optimization is the optimization of structures in order to improve stiffness or other objectives. The goal of the thesis is to explore how topology optimization can be used in applications...... in an interactive and intuitive way. By creating such applications with an intuitive and simple user interface we allow non-engineers like designers and architects to easily experiment with boundary conditions, design domains and other optimization settings. This is in contrast to commercial topology optimization...... on theory of from human-computer interaction which is described in Chapter 2. Followed by a description of the foundations of topology optimization in Chapter 3. Our applications for topology optimization in 2D and 3D are described in Chapter 4 and a game which trains the human intuition of topology...

  19. Neutrino Self-Interactions

    CERN Document Server

    Hasenkamp, Jasper

    2016-01-01

    We propose a theory that equips the active neutrinos with interactions among themselves that are at least three orders of magnitude stronger than the weak interaction. We introduce an Abelian gauge group $U(1)_x$ with vacuum expectation value $v_x \\lesssim \\mathcal{O}(100 \\textrm{ MeV})$. An asymmetric mass matrix implements the active neutrinos as massless mass eigenstates carrying "effective" charges. To stabilize $v_x$, supersymmetry breaking is mediated via loops to the additional sector with the only exception of xHiggs terms. No Standard Model interaction eigenstate carries $U(1)_x$ charge. Thus the dark photon's kinetic mixing is two-loop suppressed.With only simple and generic values of dimensionless parameters, our theory might explain the high-energy neutrino spectrum observed by IceCube including the PeV neutrinos. We comment on the imposing opportunity to incorporate a self-interacting dark matter candidate.

  20. Multiactivity in Social Interaction

    DEFF Research Database (Denmark)

    Haddington, Pentti; Keisanen, Tiina; Mondada, Lorenza;

    2014-01-01

    Doing more than one thing at the same time – a phenomenon that is often called ‘multitasking’ – is characteristic to many situations in everyday and professional life. Although we all experience it, its real time features remain understudied. Multiactivity in Social Interaction: Beyond multitasking...... offers a fresh view to the phenomenon by presenting studies that explore how two or more activities can be related and made co-relevant as people interact with one another. The studies build on the basis that multiactivity is a social, verbal and embodied phenomenon. They investigate multiactivity...... by using video recordings of real-life interactions from a range of different contexts, such as medical settings, office workplaces and car driving. With the companion collection Interacting with Objects: Language, materiality, and social activity, the book advances understanding of the complex...

  1. Interacting Agegraphic Dark Energy

    OpenAIRE

    Wei, Hao; Cai, Rong-Gen

    2007-01-01

    A new dark energy model, named "agegraphic dark energy", has been proposed recently, based on the so-called K\\'{a}rolyh\\'{a}zy uncertainty relation, which arises from quantum mechanics together with general relativity. In this note, we extend the original agegraphic dark energy model by including the interaction between agegraphic dark energy and pressureless (dark) matter. In the interacting agegraphic dark energy model, there are many interesting features different from the original agegrap...

  2. Beam-Material Interaction

    CERN Document Server

    Mokhov, N V

    2016-01-01

    Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high- intensity energetic particle beam interactions with accelerator, generic target , and detector components. It reviews the principal physical processes of fast-particle interactions with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and envir onment in challenging current and future application

  3. Soft interactions in Herwig++

    CERN Document Server

    Bahr, Manuel; Gieseke, Stefan; Seymour, Michael H

    2009-01-01

    We describe the recent developments to extend the multi-parton interaction model of underlying events in Herwig++ into the soft, non-perturbative, regime. This allows the program to describe also minimum bias collisions in which there is no hard interaction, for the first time. It is publicly available from versions 2.3 onwards and describes the Tevatron underlying event and minimum bias data. The extrapolations to the LHC nevertheless suffer considerable ambiguity, as we discuss.

  4. Quantum interaction. Selected papers

    Energy Technology Data Exchange (ETDEWEB)

    Atmanspacher, Harald [Eidgenoessische Technische Hochschule, Zurich (Switzerland); Haven, Emmanuel [Leicester Univ. (United Kingdom). School of Management; Kitto, Kirsty [Queensland Univ. of Technology, Brisbane, QLD (Australia); Raine, Derek (ed.) [Leicester Univ. (United Kingdom). Centre for Interdisciplinary Science

    2014-07-01

    This book constitutes the refereed proceedings of the 7th International Conference on Quantum Interaction, QI 2013, held in Leicester, UK, in July 2013. The 31 papers presented in this book were carefully selected from numerous submissions. The papers cover various topics on quantum interaction and revolve around four themes: information processing/retrieval/semantic representation and logic; cognition and decision making; finance/economics and social structures and biological systems.

  5. Interaction with geospatial data

    OpenAIRE

    SCHOENING, Johannes

    2015-01-01

    My research interest lies at the interaction between human-computer interaction (HCI) and geoinformatics. I am interested in developing new methods and novel user interfaces to navigate through spatial information. This article will give a brief overview on my past and current research topics and streams. Generally speaking, geography is playing an increasingly important role in computer science and also in the field of HCI ranging from social computing to natural user interfaces (NUIs). At t...

  6. Beam-Material Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Mokhov, N. V. [Fermilab; Cerutti, F. [CERN

    2016-01-01

    Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high-intensity energetic particle beam interactions with accelerator, generic target, and detector components. It reviews the principal physical processes of fast-particle interactions with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and environment in challenging current and future applications.

  7. CONCEPT OF DRUG INTERACTION

    OpenAIRE

    Singh Nidhi

    2012-01-01

    Drug interaction is an increasingly important cause of adverse reactions (ADR), and is the modification of the effect of one drug (object) by the prior or concomitant administration of another drug (precipitant drug). Drug interaction may either enhance or diminish the intended effect of one or both drugs. For example severe haemorrhage may occur if warfarin and salicylates (asprin) are combined. Precipitant drugs modify the object drug's absorption, distribution, metabolism, excretion or act...

  8. Human-machine interactions

    Science.gov (United States)

    Forsythe, J. Chris; Xavier, Patrick G.; Abbott, Robert G.; Brannon, Nathan G.; Bernard, Michael L.; Speed, Ann E.

    2009-04-28

    Digital technology utilizing a cognitive model based on human naturalistic decision-making processes, including pattern recognition and episodic memory, can reduce the dependency of human-machine interactions on the abilities of a human user and can enable a machine to more closely emulate human-like responses. Such a cognitive model can enable digital technology to use cognitive capacities fundamental to human-like communication and cooperation to interact with humans.

  9. Strongly interacting new physics

    International Nuclear Information System (INIS)

    In this talk. I will describe two aspects of the breaking of electroweak symmetry by new, strong interactions. First I will review the model independent approach to the low energy form of such new interactions emdash the electroweak chiral Lagrangian. Next I will summarize some of the phenomenological challenges facing technicolor theories, in particular those associated with the generation of the top and bottom masses. copyright 1997 American Institute of Physics

  10. Extrasolar planet interactions

    Science.gov (United States)

    Barnes, Rory; Greenberg, Richard

    2008-05-01

    The dynamical interactions of planetary systems may be a clue to their formation histories. Therefore, the distribution of these interactions provides important constraints on models of planet formation. We focus on each system's apsidal motion and proximity to dynamical instability. Although only 25 multiple planet systems have been discovered to date, our analyses in these terms have revealed several important features of planetary interactions. 1) Many systems interact such that they are near the boundary between stability and instability. 2) Planets tend to form such that at least one planet's eccentricity periodically drops to near zero. 3) Mean-motion resonant pairs would be unstable if not for the resonance. 4) Scattering of approximately equal mass planets is unlikely to produce the observed distribution of apsidal behavior. 5) Resonant interactions may be identified through calculating a system's proximity to instability, regardless of knowledge of angles such as mean longitude and longitude of periastron (e.g. GJ 317 b and c are probably in a 4:1 resonance). These properties of planetary systems have been identified through calculation of two parameters that describe the interaction. The apsidal interaction can be quantified by determining how close a planet is to an apsidal separatrix (a boundary between qualitatively different types of apsidal oscillations, e.g. libration or circulation of the major axes). This value can be calculated through short numerical integrations. The proximity to instability can be measured by comparing the observed orbital elements to an analytic boundary that describes a type of stability known as Hill stability. We have set up a website dedicated to presenting the most up-to-date information on dynamical interactions: http://www.lpl.arizona.edu/~rory/research/xsp/dynamics.

  11. Studies of Embodied Interaction

    OpenAIRE

    Stycke, Simon; Castillo Hansen, Frederikke; Debel, Niels; Heebøll, Lauge; Mohr, Markus

    2013-01-01

    The purpose of this project was to perform general studies on the phenomenon Embodied Interaction. Our motivation for doing this was the increasing interest, both creatively and commercially, in new ways to use our computer technologies in the tangible world, as well as in affecting the human perception. Embodied Interaction allows a person to use his body as an instrument in the world, and utilize his bodily presence and motions, to control software and hardware alike. By delv...

  12. Nonadditivity of nanoparticle interactions.

    Science.gov (United States)

    Batista, Carlos A Silvera; Larson, Ronald G; Kotov, Nicholas A

    2015-10-01

    Understanding interactions between inorganic nanoparticles (NPs) is central to comprehension of self-organization processes and a wide spectrum of physical, chemical, and biological phenomena. However, quantitative description of the interparticle forces is complicated by many obstacles that are not present, or not as severe, for microsize particles (μPs). Here we analyze the sources of these difficulties and chart a course for future research. Such difficulties can be traced to the increased importance of discreteness and fluctuations around NPs (relative to μPs) and to multiscale collective effects. Although these problems can be partially overcome by modifying classical theories for colloidal interactions, such an approach fails to manage the nonadditivity of electrostatic, van der Waals, hydrophobic, and other interactions at the nanoscale. Several heuristic rules identified here can be helpful for discriminating between additive and nonadditive nanoscale systems. Further work on NP interactions would benefit from embracing NPs as strongly correlated reconfigurable systems with diverse physical elements and multiscale coupling processes, which will require new experimental and theoretical tools. Meanwhile, the similarity between the size of medium constituents and NPs makes atomic simulations of their interactions increasingly practical. Evolving experimental tools can stimulate improvement of existing force fields. New scientific opportunities for a better understanding of the electronic origin of classical interactions are converging at the scale of NPs. PMID:26450215

  13. Interactions between photodegradation components

    Directory of Open Access Journals (Sweden)

    Abdollahi Yadollah

    2012-09-01

    Full Text Available Abstract Background The interactions of p-cresol photocatalytic degradation components were studied by response surface methodology. The study was designed by central composite design using the irradiation time, pH, the amount of photocatalyst and the p-cresol concentration as variables. The design was performed to obtain photodegradation % as actual responses. The actual responses were fitted with linear, two factor interactions, cubic and quadratic model to select an appropriate model. The selected model was validated by analysis of variance which provided evidences such as high F-value (845.09, very low P-value (2 = 0.999, adjusted R-squared (Radj2 = 0.998, predicted R-squared (Rpred2 = 0.994 and the adequate precision (95.94. Results From the validated model demonstrated that the component had interaction with irradiation time under 180 min of the time while the interaction with pH was above pH 9. Moreover, photocatalyst and p-cresol had interaction at minimal amount of photocatalyst (p-cresol. Conclusion These variables are interdependent and should be simultaneously considered during the photodegradation process, which is one of the advantages of the response surface methodology over the traditional laboratory method.

  14. Strongly interacting Fermi gases

    Directory of Open Access Journals (Sweden)

    Bakr W.

    2013-08-01

    Full Text Available Strongly interacting gases of ultracold fermions have become an amazingly rich test-bed for many-body theories of fermionic matter. Here we present our recent experiments on these systems. Firstly, we discuss high-precision measurements on the thermodynamics of a strongly interacting Fermi gas across the superfluid transition. The onset of superfluidity is directly observed in the compressibility, the chemical potential, the entropy, and the heat capacity. Our measurements provide benchmarks for current many-body theories on strongly interacting fermions. Secondly, we have studied the evolution of fermion pairing from three to two dimensions in these gases, relating to the physics of layered superconductors. In the presence of p-wave interactions, Fermi gases are predicted to display toplogical superfluidity carrying Majorana edge states. Two possible avenues in this direction are discussed, our creation and direct observation of spin-orbit coupling in Fermi gases and the creation of fermionic molecules of 23Na 40K that will feature strong dipolar interactions in their absolute ground state.

  15. Structural elucidation of the interaction between neurodegenerative disease-related tau protein with model lipid membranes

    Science.gov (United States)

    Jones, Emmalee M.

    A protein's sequence of amino acids determines how it folds. That folded structure is linked to protein function, and misfolding to dysfunction. Protein misfolding and aggregation into beta-sheet rich fibrillar aggregates is connected with over 20 neurodegenerative diseases, including Alzheimer's disease (AD). AD is characterized in part by misfolding, aggregation and deposition of the microtubule associated tau protein into neurofibrillary tangles (NFTs). However, two questions remain: What is tau's fibrillization mechanism, and what is tau's cytotoxicity mechanism? Tau is prone to heterogeneous interactions, including with lipid membranes. Lipids have been found in NFTs, anionic lipid vesicles induced aggregation of the microtubule binding domain of tau, and other protein aggregates induced ion permeability in cells. This evidence prompted our investigation of tau's interaction with model lipid membranes to elucidate the structural perturbations those interactions induced in tau protein and in the membrane. We show that although tau is highly charged and soluble, it is highly surface active and preferentially interacts with anionic membranes. To resolve molecular-scale structural details of tau and model membranes, we utilized X-ray and neutron scattering techniques. X-ray reflectivity indicated tau aggregated at air/water and anionic lipid membrane interfaces and penetrated into membranes. More significantly, membrane interfaces induced tau protein to partially adopt a more compact conformation with density similar to folded protein and ordered structure characteristic of beta-sheet formation. This suggests possible membrane-based mechanisms of tau aggregation. Membrane morphological changes were seen using fluorescence microscopy, and X-ray scattering techniques showed tau completely disrupts anionic membranes, suggesting an aggregate-based cytotoxicity mechanism. Further investigation of protein constructs and a "hyperphosphorylation" disease mimic helped

  16. Gene-environment interaction.

    Science.gov (United States)

    Manuck, Stephen B; McCaffery, Jeanne M

    2014-01-01

    With the advent of increasingly accessible technologies for typing genetic variation, studies of gene-environment (G×E) interactions have proliferated in psychological research. Among the aims of such studies are testing developmental hypotheses and models of the etiology of behavioral disorders, defining boundaries of genetic and environmental influences, and identifying individuals most susceptible to risk exposures or most amenable to preventive and therapeutic interventions. This research also coincides with the emergence of unanticipated difficulties in detecting genetic variants of direct association with behavioral traits and disorders, which may be obscured if genetic effects are expressed only in predisposing environments. In this essay we consider these and other rationales for positing G×E interactions, review conceptual models meant to inform G×E interpretations from a psychological perspective, discuss points of common critique to which G×E research is vulnerable, and address the role of the environment in G×E interactions.

  17. Dark Matter Gravitational Interactions

    CERN Document Server

    Tucker, R W

    1998-01-01

    We argue that the conjectured dark mater in the Universe may be endowed with a new kind of gravitational charge that couples to a short range gravitational interaction mediated by a massive vector field. A model is constructed that assimilates this concept into ideas of current inflationary cosmology. The model is also consistent with the observed behaviour of galactic rotation curves according to Newtonian dynamics. The essential idea is that stars composed of ordinary (as opposed to dark matter) experience Newtonian forces due to the presence of an all pervading background of massive gravitationally charged cold dark matter. The novel gravitational interactions are predicted to have a significant influence on pre-inflationary cosmology. The precise details depend on the nature of a gravitational Proca interaction and the description of matter. A gravitational Proca field configuration that gives rise to attractive forces between dark matter charges of like polarity exhibits homogeneous isotropic eternal cos...

  18. Interactive Karyotyping Training

    Directory of Open Access Journals (Sweden)

    Ashwin Kotwaliwale

    2013-01-01

    Full Text Available Despite the wide use of newer techniques in genetic diagnostics, there remains a need for technologists to learn human chromosome morphology, identify abnormal metaphases and report clinical abnormalities. Global short age of cytogenetic trainers and a time consuming training process makes Karyotyping training difficult. We have developed a web based interactive Karyotyping training tool, KaryoTutor©, that allows technologists to learn karyotyping in an interactive environment and aids the trainer in the training process. KaryoTutor©provides visual clues for identifying abnormal chromosomes, provides instant test scores and includes a reference library of ideograms,sample chromosome images and reference materials. Trainees are able to recursively work on a case till a satisfactory result is achieved,with KaryoTutor providing interactive inputs.Additionally, trainers can assign cases and monitor trainee progress using audit trail management and other administrative features.

  19. Star-Planet Interactions

    CERN Document Server

    Shkolnik, Evgenya; Cranmer, Steven; Fares, Rim; Fridlund, Malcolm; Pont, Frederic; Schmitt, Juergen; Smith, Alexis; Suzuki, Takeru

    2008-01-01

    Much effort has been invested in recent years, both observationally and theoretically, to understand the interacting processes taking place in planetary systems consisting of a hot Jupiter orbiting its star within 10 stellar radii. Several independent studies have converged on the same scenario: that a short-period planet can induce activity on the photosphere and upper atmosphere of its host star. The growing body of evidence for such magnetic star-planet interactions includes a diverse array of photometric, spectroscopic and spectropolarimetric studies. The nature of which is modeled to be strongly affected by both the stellar and planetary magnetic fields, possibly influencing the magnetic activity of both bodies, as well as affecting irradiation and non-thermal and dynamical processes. Tidal interactions are responsible for the circularization of the planet orbit, for the synchronization of the planet rotation with the orbital period, and may also synchronize the outer convective envelope of the star with...

  20. Sonic Interaction Design

    DEFF Research Database (Denmark)

    created for such contexts as mobile music, sensorimotor learning, rehabilitation, and gaming. The goal is not only to extend the existing research and pedagogical approaches to SID but also to foster domains of practice for sound designers, architects, interaction designers, media artists, product......) challenges these prevalent approaches by considering sound as an active medium that can enable novel sensory and social experiences through interactive technologies. This book offers an overview of the emerging SID research, discussing theories, methods, and practices, with a focus on the multisensory...... aspects of sonic experience. Sonic Interaction Design gathers contributions from scholars, artists, and designers working at the intersections of fields ranging from electronic music to cognitive science. They offer both theoretical considerations of key themes and case studies of products and systems...

  1. "Interaction-Free" Imaging

    CERN Document Server

    White, A G; Nairz, O; Kwiat, P G; White, Andrew G.; Mitchell, Jay R.; Nairz, Olaf; Kwiat, Paul G.

    1998-01-01

    Using the complementary wave- and particle-like natures of photons, it is possible to make ``interaction-free'' measurements where the presence of an object can be determined with no photons being absorbed. We investigated several ``interaction-free'' imaging systems, i.e. systems that allow optical imaging of photosensitive objects with less than the classically expected amount of light being absorbed or scattered by the object. With the most promising system, we obtained high-resolution (10 \\mu m), one-dimensional profiles of a variety of objects (human hair, glass and metal wires, cloth fibers), by raster scanning each object through the system. We discuss possible applications and the present and future limits for interaction-free imaging.

  2. Dike/Drift Interactions

    Energy Technology Data Exchange (ETDEWEB)

    E. Gaffiney

    2004-11-23

    This report presents and documents the model components and analyses that represent potential processes associated with propagation of a magma-filled crack (dike) migrating upward toward the surface, intersection of the dike with repository drifts, flow of magma in the drifts, and post-magma emplacement effects on repository performance. The processes that describe upward migration of a dike and magma flow down the drift are referred to as the dike intrusion submodel. The post-magma emplacement processes are referred to as the post-intrusion submodel. Collectively, these submodels are referred to as a conceptual model for dike/drift interaction. The model components and analyses of the dike/drift interaction conceptual model provide the technical basis for assessing the potential impacts of an igneous intrusion on repository performance, including those features, events, and processes (FEPs) related to dike/drift interaction (Section 6.1).

  3. History of Weak Interactions

    Science.gov (United States)

    Lee, T. D.

    1970-07-01

    While the phenomenon of beta-decay was discovered near the end of the last century, the notion that the weak interaction forms a separate field of physical forces evolved rather gradually. This became clear only after the experimental discoveries of other weak reactions such as muon-decay, muon-capture, etc., and the theoretical observation that all these reactions can be described by approximately the same coupling constant, thus giving rise to the notion of a universal weak interaction. Only then did one slowly recognize that the weak interaction force forms an independent field, perhaps on the same footing as the gravitational force, the electromagnetic force, and the strong nuclear and sub-nuclear forces.

  4. Dike/Drift Interactions

    International Nuclear Information System (INIS)

    This report presents and documents the model components and analyses that represent potential processes associated with propagation of a magma-filled crack (dike) migrating upward toward the surface, intersection of the dike with repository drifts, flow of magma in the drifts, and post-magma emplacement effects on repository performance. The processes that describe upward migration of a dike and magma flow down the drift are referred to as the dike intrusion submodel. The post-magma emplacement processes are referred to as the post-intrusion submodel. Collectively, these submodels are referred to as a conceptual model for dike/drift interaction. The model components and analyses of the dike/drift interaction conceptual model provide the technical basis for assessing the potential impacts of an igneous intrusion on repository performance, including those features, events, and processes (FEPs) related to dike/drift interaction (Section 6.1)

  5. Neutrino interactions with nuclei

    CERN Document Server

    Leitner, T; Mosel, U; Alvarez-Ruso, L

    2008-01-01

    Current long baseline experiments aim at measuring neutrino oscillation parameters with a high precision. A critical quantity is the neutrino energy which can not be measured directly but has to be reconstructed from the observed hadrons. A good knowledge of neutrino-nucleus interactions is thus necessary to minimize the systematic uncertainties in neutrino fluxes, backgrounds and detector responses. In particular final-state interactions inside the target nucleus modify considerably the particle yields through rescattering, charge-exchange and absorption. Nuclear effects can be described with our coupled channel GiBUU transport model where the neutrino first interacts with a bound nucleon producing secondary particles which are then transported out of the nucleus. In this contribution, we give some examples for the application of our model focusing in particular on the MiniBooNE and K2K experiments.

  6. Honesty through repeated interactions.

    Science.gov (United States)

    Rich, Patricia; Zollman, Kevin J S

    2016-04-21

    In the study of signaling, it is well known that the cost of deception is an essential element for stable honest signaling in nature. In this paper, we show how costs for deception can arise endogenously from repeated interactions between individuals. Utilizing the Sir Philip Sidney game as an illustrative case, we show that repeated interactions can sustain honesty with no observable signal costs, even when deception cannot be directly observed. We provide a number of potential experimental tests for this theory which distinguish it from the available alternatives. PMID:26869213

  7. Interactive Shape Design

    CERN Document Server

    Cani, Marie-Paule; Wyvill, Geoff

    2008-01-01

    Providing an intuitive modeling system, which would enable us to communicate about any free-form shape we have in mind at least as quickly as with real-world tools, is one of the main challenges of digital shape design. The user should ideally be able to create, deform, and progressively add details to a shape, without being aware of the underlying mathematical representation nor being tied by any constraint on the geometrical or topological nature of the model. This book presents the field of interactive shape design from this perspective. Since interactively creating a shape builds on the hu

  8. Interacting binary stars

    CERN Document Server

    Sahade, Jorge; Ter Haar, D

    1978-01-01

    Interacting Binary Stars deals with the development, ideas, and problems in the study of interacting binary stars. The book consolidates the information that is scattered over many publications and papers and gives an account of important discoveries with relevant historical background. Chapters are devoted to the presentation and discussion of the different facets of the field, such as historical account of the development in the field of study of binary stars; the Roche equipotential surfaces; methods and techniques in space astronomy; and enumeration of binary star systems that are studied

  9. Child Computer Interaction SIG

    DEFF Research Database (Denmark)

    Read, Janet; Hourcade, Juan Pablo; Markopoulos, Panos;

    The discipline of Child Computer Interaction (CCI) has been steadily growing and it is now firmly established as a community in its own right, having the annual IDC (Interaction and Design for Children) conference and its own journal and also enjoying its role as a highly recognisable and vibrant...... contributor to the ACM CHI conference. Having recently been given status as an IFIP (International Federation for Information Processing) TC13 working group, the community now needs to make plans around its academic themes and its coherence as a developing academic community. The CCI SIG at CHI aims to use...

  10. Mobile Collocated Interactions

    DEFF Research Database (Denmark)

    Lucero, Andrés; Clawson, James; Lyons, Kent;

    2015-01-01

    Mobile devices such as smartphones and tablets were originally conceived and have traditionally been utilized for individual use. Research on mobile collocated interactions has been looking at situations in which collocated users engage in collaborative activities using their mobile devices, thus......-smaller computers, ones that can be worn on our wrists or other parts of the body. The focus of this workshop is to bring together a community of researchers, designers and practitioners to explore the potential of extending mobile collocated interactions to the use of wearable devices....

  11. Thoughts on Interaction Design

    CERN Document Server

    Kolko, Jon

    2009-01-01

    Interaction Designers-whether practicing as Usability Engineers, Visual Interface Designers, or Information Architects-attempt to understand and shape human behavior in order to design products that are at once usable, useful, and desirable. Although the value of design is now recognized as essential to product development, the field is often misunderstood by managers and other team members, who don't understand a designer's role in a team. This can cause inefficient and ineffective products. Thoughts on Interaction Design gives individuals engaged in this profession the dialogue to justify t

  12. Exploring governmentality as interaction

    DEFF Research Database (Denmark)

    Fahnøe, Kristian

    2010-01-01

    . The aim is to develop an interactionstic framework that may contribute to the understanding of how individuals in institutional settings resist or accept the objectifications and the techniques of power which governmentality rely on. And thereby also contribute to the understanding of how subjectification......Based on my ongoing work in relation my PhD thesis this paper examines how the Foucauldian concept of governmentality as social control can be understood as interaction among individuals in institutional settings. In theoretical terms the paper examines how governmentality can be conceptualized...... in relation to governmentality unfolds interaction among individuals....

  13. Empowered interaction through creativity

    DEFF Research Database (Denmark)

    Hasselblad, Stefan; Petersson, Eva; Brooks, Tony

    2007-01-01

    This paper reflects upon a case study where exploration, play and empowerment in interactive therapy sessions with audio and visual stimuli resulted in achievement, self-esteem and a shared pride between a young adult with profound and multiple learning disabilities (PMLD), his mother and the spe......This paper reflects upon a case study where exploration, play and empowerment in interactive therapy sessions with audio and visual stimuli resulted in achievement, self-esteem and a shared pride between a young adult with profound and multiple learning disabilities (PMLD), his mother...

  14. Cultivating objects in interaction

    DEFF Research Database (Denmark)

    Hazel, Spencer

    2014-01-01

    This paper demonstrates how an initial indexing of objects through gesture and talk provides a residual basis for later indexical development across a stretch of discourse. I show how participants are able to perform an initial mobilization of affordances (Hutchby, 2001) of objects in the immediate...... the interactional resources which mundane everyday objects provide interactants in the multimodal design of their turns-at-talk. Although the objects which feature in the data – for example notepads, tables, computer monitors – have practical functions within the social ecology of these institutional settings...

  15. Interactive Collaborative Books

    OpenAIRE

    Al-Mutawa, Abdullah M.

    2007-01-01

    Books are one of the most important tools to convey knowledge, they survived to be a convenient and portable source of information. On the other side, Electronic books (e-books) are playing a big role in attracting a huge number of readers, but still paper books are preferable by many people due to some drawbacks in e-books. Yet, Interactive books combines all positive features in ordinary books as well as e-books, the author is introducing a new Interactive Collaborative book that might chan...

  16. Interaction and mindreading

    DEFF Research Database (Denmark)

    Michael, John

    2011-01-01

    In recent years, a number of theorists have developed approaches to social cognition that highlight the centrality of social interaction as opposed to mindreading (e.g. Gallagher and Zahavi 2008; Gallagher 2001, 2007, 2008; Hobson 2002; Reddy 2008; Hutto 2004; De Jaegher 2009; De Jaegher and Di...... Paolo 2007; Fuchs and De Jaegher 2009; De Jaegher, Di Paolo and Gallagher 2010). There are important differences among these approaches, as I will discuss, but they are united by their commitment to the claim that various embodied and extended processes sustain social understanding and interaction...

  17. Acting, interacting, enacting

    DEFF Research Database (Denmark)

    Hazel, Spencer

    2015-01-01

    This study followed the rehearsals of a 2014 Copenhagen theatre production of Margaret Edson’s play WIT. The play depicts the palliative care provision of a woman diagnosed with advanced ovarian cancer, with an important theme of the narrative centering around the dehumanizing practices that result...... from professional medical treatment of the body, rather than of the person. I adopt an interaction analytic approach to investigate how theatre practitioners develop representations of interaction in clinical environments. The article introduces one practice from the theatre rehearsal setting – doing...

  18. A tabletop interactive storytelling system: designing for social interaction

    NARCIS (Netherlands)

    Alofs, Thijs; Theune, Mariët; Swartjes, Ivo

    2015-01-01

    This paper presents the Interactive Storyteller, a multi-user interface for AI-based interactive storytelling, where stories emerge from the interaction of human players with intelligent characters in a simulated story world. To support face-to-face contact and social interaction, we position users

  19. Interactive Tabletops in Education

    Science.gov (United States)

    Dillenbourg, Pierre; Evans, Michael

    2011-01-01

    Interactive tabletops are gaining increased attention from CSCL researchers. This paper analyses the relation between this technology and teaching and learning processes. At a global level, one could argue that tabletops convey a socio-constructivist flavor: they support small teams that solve problems by exploring multiple solutions. The…

  20. Electromagnetic interaction of metamaterials

    Science.gov (United States)

    Canales, Peter R.

    The observation of extraordinary transmission through subwavelength apertures has propelled a great interest in understanding its nature. It defies classical theories of electromagnetic interaction by demanding a closer examination of the surface properties. Traditionally, as surface features become much smaller in size than a single wavelength of interest, the structure is essentially continuous. Any periodic subwavelength corrugation or aperture array should not interact strongly with an incident field and therefore not contribute to any significant transmission through the film. We find that this is not always the case and that we may tune the surface geometry at these scales to affect the overall medium behavior. It is possible that a material may transcend its own natural properties and, in essence, become a metamaterial. The following analysis examines the concepts of metamaterials from a fundamental viewpoint. It does not seek to disrupt classical theories but instead demonstrates their validity to describe a new phenomenon. Several theories have been proposed that offer unique surface interactions as evidence of enhanced transmission. It is proposed that a fundamental Maxwell representation is sufficient in predicting the interaction of an electromagnetic wave with a metamaterial. In particular, a formalism has been developed to analyze enhanced transmission through a metallic grating structure. To experimentally validate this model, a fabrication procedure has been developed that allows for the production of quality thick film structures with subwavelength features. Finally, the analysis of metamaterials looks towards the RF spectrum to demonstrate a novel design to achieve conformal waveguides and antennas.

  1. Tritium-surface interactions

    International Nuclear Information System (INIS)

    The report deals broadly with tritium-surface interactions as they relate to a fusion power reactor enterprise, viz., the vacuum chamber, first wall, peripherals, pumping, fuel recycling, isotope separation, repair and maintenance, decontamination and safety. The main emphasis is on plasma-surface interactions and the selection of materials for fusion chamber duty. A comprehensive review of the international (particularly U.S.) research and development is presented based upon a literature review (about 1 000 reports and papers) and upon visits to key laboratories, Sandia, Albuquerque, Sandia, Livermore and EGβG Idaho. An inventory of Canadian expertise and facilities for RβD on tritium-surface interactions is also presented. A number of proposals are made for the direction of an optimal Canadian RβD program, emphasizing the importance of building on strength in both the technological and fundamental areas. A compendium of specific projects and project areas is presented dealing primarily with plasma-wall interactions and permeation, anti-permeation materials and surfaces and health, safety and environmental considerations. Potential areas of industrial spinoff are identified

  2. Interaction Before Agriculture

    DEFF Research Database (Denmark)

    Richter, Tobias; Garrard, Andrew; Allcock, Samantha;

    2011-01-01

    This article discusses social interaction in the Epipalaeolithic of southwest Asia. Discussions of contact, social relationships and social organization have primarily focused on the Pre-Pottery Neolithic and are often considered to represent typical hallmarks of emergent farming societies. The h...

  3. CONCEPT OF DRUG INTERACTION

    Directory of Open Access Journals (Sweden)

    Singh Nidhi

    2012-07-01

    Full Text Available Drug interaction is an increasingly important cause of adverse reactions (ADR, and is the modification of the effect of one drug (object by the prior or concomitant administration of another drug (precipitant drug. Drug interaction may either enhance or diminish the intended effect of one or both drugs. For example severe haemorrhage may occur if warfarin and salicylates (asprin are combined. Precipitant drugs modify the object drug's absorption, distribution, metabolism, excretion or actual clinical effect. Nonsteroidal anti-inflammatory drugs, antibiotics and, in particular, rifampin are common precipitant drugs prescribed in primary care practice. Drugs with a narrow therapeutic range or low therapeutic index are more likely to be the objects for serious drug interactions. Object drugs in common use include warfarin, fluoroquinolones, antiepileptic drugs, oral contraceptives, cisapride and 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors. Many other drugs, act as precipitants or objects, and a number of drugs act as both. The aim of present review is to throw light on the concept of drug interaction.

  4. Towards Directional Colloidal Interactions

    NARCIS (Netherlands)

    Kamp, M.

    2015-01-01

    Colloids are particles with a size on the scale of microns in at least one dimension. The central theme of this thesis is the synthesis of model colloids with anisotropic interactions - often called `patchy' colloids, as well as the search for new ways to assemble such colloids. Methods to build non

  5. Unparticle self-interactions

    Science.gov (United States)

    Georgi, Howard; Kats, Yevgeny

    2010-02-01

    We develop techniques for studying the effects of self-interactions in the conformal sector of an unparticle model. Their physics is encoded in the higher n-point functions of the conformal theory. We study inclusive processes and argue that the inclusive production of unparticle stuff in standard model processes due to the unparticle self-interactions can be decomposed using the conformal partial wave expansion and its generalizations into a sum over contributions from the production of various kinds of unparticle stuff, corresponding to different primary conformal operators. Such processes typically involve the production of unparticle stuff associated with operators other than those to which the standard model couples directly. Thus just as interactions between particles allow scattering processes to produce new particles in the final state, so unparticle self-interactions cause the production of various kinds of unparticle stuff. We discuss both inclusive and exclusive methods for computing these processes. The resulting picture, we believe, is a step towards understanding what unparticle stuff “looks like” because it is quite analogous to way we describe the production and scattering of ordinary particles in quantum field theory, with the primary conformal operators playing the role of particles and the coefficients in the conformal partial wave expansion (and its generalization to include more fields) playing the role of amplitudes. We exemplify our methods in the 2D toy model that we discussed previously in which the Banks-Zaks theory is exactly solvable.

  6. Fibronectin-cell interactions

    DEFF Research Database (Denmark)

    Couchman, J R; Austria, M R; Woods, A

    1990-01-01

    Fibronectins are widespread extracellular matrix and body fluid glycoproteins, capable of multiple interactions with cell surfaces and other matrix components. Their structure at a molecular level has been resolved, yet there are still many unanswered questions regarding their biologic activity i...

  7. Model Checking Feature Interactions

    DEFF Research Database (Denmark)

    Le Guilly, Thibaut; Olsen, Petur; Pedersen, Thomas;

    2015-01-01

    This paper presents an offline approach to analyzing feature interactions in embedded systems. The approach consists of a systematic process to gather the necessary information about system components and their models. The model is first specified in terms of predicates, before being refined to t...

  8. Proxemic Mobile Collocated Interactions

    DEFF Research Database (Denmark)

    Porcheron, Martin; Lucero, Andrés; Quigley, Aaron;

    2016-01-01

    Recent research on mobile collocated interactions has been looking at situations in which collocated users engage in collaborative activities using their mobile devices. However, existing practices fail to fully account for the culturally-dependent spatial relationships between people and their d...

  9. Gaze interaction from bed

    DEFF Research Database (Denmark)

    Hansen, John Paulin; San Agustin, Javier; Jensen, Henrik Tomra Skovsgaard Hegner

    2011-01-01

    This paper presents a low-cost gaze tracking solution for bedbound people composed of free-ware tracking software and commodity hardware. Gaze interaction is done on a large wall-projected image, visible to all people present in the room. The hardware equipment leaves physical space free to assis...

  10. Alkane dimers interaction

    DEFF Research Database (Denmark)

    Ferrighi, Lara; Madsen, Georg Kent Hellerup; Hammer, Bjørk

    2010-01-01

    The interaction energies of a series of n-alkane dimers, from methane to decane, have been investigated with Density Functional Theory (DFT), using the MGGA-M06-L density functional. The results are compared both to the available wavefunction-based values as well as to dispersion corrected DFT...

  11. Interactions within wastewater systems

    NARCIS (Netherlands)

    Langeveld, J.G.

    2004-01-01

    Wastewater systems consist of sewer systems and wastewater treatment works. As the performance of a wastewater treatment plant is affected by the characteristics, i.e. operation and design, of the contributing sewer systems, knowledge of the interactions between sewers and wastewater treatment works

  12. Connectionist Interaction Information Retrieval.

    Science.gov (United States)

    Dominich, Sandor

    2003-01-01

    Discussion of connectionist views for adaptive clustering in information retrieval focuses on a connectionist clustering technique and activation spreading-based information retrieval model using the interaction information retrieval method. Presents theoretical as well as simulation results as regards computational complexity and includes…

  13. Experiencing affective interactive art

    NARCIS (Netherlands)

    Bialoskorski, Leticia S.S.; Westerink, Joyce H.D.M.; Broek, van den Egon L.

    2010-01-01

    The progress in the field of affective computing enables the realization of affective art. This paper describes the affective interactive art system Mood Swings, which interprets and visualizes affect expressed by a person. Mood Swings is founded on the integration of a framework for affective move

  14. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Our theoretical research on dust-plasma interactions has concentrated on three main areas: (a)studies of grain charging and applications; (b) waves and instabilities in weakly correlated dusty plasma with applications to space and laboratory plasmas; (c) waves in strongly coupled dusty plasmas.

  15. Protein–DNA Interactions

    NARCIS (Netherlands)

    Kovacic, L.; Boelens, R.

    2012-01-01

    The recognition of specific DNA sequences by proteins and the coupling to signaling events are fundamental occurrences that lie at the root of many cellular processes. Many examples of tight control by protein–DNA interactions can be found in such dynamic processes as transcription, replication and

  16. Interactions of cosmic superstrings

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Mark G.; /Fermilab

    2007-06-01

    We develop methods by which cosmic superstring interactions can be studied in detail. These include the reconnection probability and emission of radiation such as gravitons or small string loops. Loop corrections to these are discussed, as well as relationships to (p; q)-strings. These tools should allow a phenomenological study of string models in anticipation of upcoming experiments sensitive to cosmic string radiation.

  17. Interactive Foresight Simulation

    DEFF Research Database (Denmark)

    Hansen, Mette Sanne; Rasmussen, Lauge Baungaard; Jacobsen, Peter

    2016-01-01

    The Combined Simulation Approach (CSA) is a way to evaluate risks and address potential unforeseen problems in a more interactive way than what is often observed in practice in companies or sectors. The approach is based on a combination of scenario analysis and discrete-event computer simulation...

  18. Urban Interaction Design

    DEFF Research Database (Denmark)

    Brynskov, Martin; Bermúdez, Juan Carlos Carvajal; Fernández, Manu;

    to the table? What are the key concepts they are addressing in their work? In the second part of the book named 'Trends', we go into current developments in the networked city and how urban interaction design as a field addresses these. Taken together, these sections will not give the definite definition...

  19. Interactive Architecture #2

    NARCIS (Netherlands)

    Oosterhuis, K.; Xia, X.

    2009-01-01

    This is the second issue (of twelve) of iA bookzine. iA brings together interdisciplinary perspectives to the topic of "Interactive Architecture" (IA) - from researchers, students, guest lecturers from Hyperbody), and experts from other organizations. This second issue, like the first, consists of p

  20. Protein–protein interactions

    NARCIS (Netherlands)

    Janin, J.; Bonvin, A.M.J.J.

    2013-01-01

    We are proud to present the first edition of the Protein–protein interactions Section of Current Opinion in Structural Biology. The Section is new, but the topic has been present in the journal from the very start. Volume 1, Issue 1, dated February 1991, had a review by Janin entitled Protein–protei

  1. Relativistic Geometry and Weak Interactions

    CERN Document Server

    González-Martin, G R

    2000-01-01

    Geometric interactions in a new relativistic geometric unified theory include interactions other than gravitation and electromagnetism. In a low energy limit one of these interactions leads essentially to a Fermi type theory of weak interactions including the Hamiltonian and coupling constant.

  2. Interactions of tritium and materials

    Energy Technology Data Exchange (ETDEWEB)

    Yamawaki, Michio; Yamaguchi, Kenji; Tanaka, Satoru; Ono, Futaba (Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.); Yamamoto, Takuya

    1993-11-01

    In D-T burning fusion reactors, problems related to tritium-material interactions are vitally important. From this point of view, plasma-material interactions, blanket breeder material-tritium interactions, safety aspects of tritium-material interactions and tritium storage materials are reviewed with emphasis on the works going on in the authors' laboratories. (author) 83 refs.

  3. Serious drug interactions.

    Science.gov (United States)

    Aronson, J

    1993-10-01

    Of the many varieties of drug interactions, which occur when the disposition or actions of one drug are changed by another, only a few are serious or potentially fatal. A representative outline of some of these illustrates the problem. Precipitant drugs are those which produce the interaction, and object drugs are those whose effects are changed. The interactions which are usually significant are those which alter the metabolism, involve renal excretion, or change the effects of the object drug, especially when the object drug has a low therapeutic index (cardiovascular drugs, anticoagulants, drugs acting on the brain, hypoglycemic drugs, hormones, and cytotoxic drugs). Warfarin toxicity, for example, is produced by aspirin, phenylbutazone, and azapropazone. The dosage requirements of warfarin are reduced by chloramphenicol, ciprofloxacin and other quinolones, erythromycin and some of the other macrolides, metronidazole and other imidazoles, tetracyclines, amiodarone, cimetidine (but not ranitidine), and fibrates. Potassium-depleting drugs can potentiate the action of digoxin, and the elimination of digoxin can be reduced by amiodarone, propafenone, quinidine, and verapamil. Combined oral contraceptives can lose effectiveness through the interaction of carbamazepine, griseofulvin, phenytoin, or rifampicin, which increase estrogen metabolism. In addition, broad-spectrum antibiotics such as ampicillin or tetracyclines also reduce contraceptive effectiveness by altering gut absorption. Even a single drink of an alcoholic beverage may be dangerous to people taking antidepressants, antihistamines, antipsychotic drugs, benzodiazepines, or lithium. Antihistamines suffer inhibited metabolism in the liver if taken in conjunction with the antifungal imidazoles and some of the macrolide antibiotics. Cardiotoxicity of antihistamines is also enhanced by drugs with similar cardiotoxic effects. Lithium potentiation is enhanced by the new serotonin-reuptake inhibitors, and lithium

  4. Interactive White Board

    Directory of Open Access Journals (Sweden)

    Asadullah Khan Praveen Kumar Arun Nair Rishi R Hegde

    2012-02-01

    Full Text Available Visual Screen uses an inexpensive technique to transform an ordinary screen into a touch screen[1] using an ordinary camera[2]. The system can fullfill many tasks such as controlling a remote large display, and simulating a physical keyboard[4]. Users can naturally use their fingers or other tip pointers to issue commands and type texts. In many intelligent environments, instead of using conventional mice[3], keyboards[4] and joysticks[5], people are looking for an intuitive, immersive and cost-efficient interaction device. We describe two vision-based interface systems[10]. The first, Visual Screen, uses an inexpensive technique to transform an ordinary screen into a touch screen[1] using an ordinary camera[2], and a user can use his/her finger to interact with the computer. Touch screens[1] are very convenient because one can directly point to where it is interesting. No conventional mice[3] are needed.

  5. Interactive protein manipulation

    Energy Technology Data Exchange (ETDEWEB)

    SNCrivelli@lbl.gov

    2003-07-01

    We describe an interactive visualization and modeling program for the creation of protein structures ''from scratch''. The input to our program is an amino acid sequence -decoded from a gene- and a sequence of predicted secondary structure types for each amino acid-provided by external structure prediction programs. Our program can be used in the set-up phase of a protein structure prediction process; the structures created with it serve as input for a subsequent global internal energy minimization, or another method of protein structure prediction. Our program supports basic visualization methods for protein structures, interactive manipulation based on inverse kinematics, and visualization guides to aid a user in creating ''good'' initial structures.

  6. Space for Interaction

    DEFF Research Database (Denmark)

    Jørgensen, Mariane Ellen; Folmer, Mette Blicher; Mullins, Michael;

    with chronic pain, the effect and experience of two different rooms for group therapy were compared. Three hypotheses were tested: 1) Room decor affects the interaction and thus the psychotherapeutic group therapy 2) The meaning of space for the interaction could be measured on the effect of treatment 3...... room B as their preferred working tool in the therapies The treatment itself does not affect outcome measured as pain and life quality. Group A and B did not differ from group W (patients on waiting list), though all patient who received treatment was satisfied or very satisfied with treatment...... is there for a reason. Everything is functional and contributes positively to the experience of the space. Design solutions based on research, therapeutic experience and architectural experience OBJECTIVES That space can support group therapy through: - Different needs of rest - Psychic resting place - Ease and order...

  7. Multiparton Interactions and Rescattering

    CERN Document Server

    Corke, Richard

    2009-01-01

    The concept of multiple partonic interactions in hadronic events is vital for the understanding of both minimum-bias and underlying-event physics. The area is rather little studied, however, and current models offer a far from complete coverage, even of the effects we know ought to be there. In this article we address one such topic, namely that of rescattering, where an already scattered parton is allowed to take part in another subsequent scattering. A framework for rescattering is introduced for the Pythia 8 event generator and fully integrated with normal multiparton interactions and initial- and final-state radiation. Using this model, the effects on event structure are studied, and distributions are shown both for minimum-bias and jet events.

  8. Interactive design center.

    Energy Technology Data Exchange (ETDEWEB)

    Pomplun, Alan R. (Sandia National Laboratories, Livermore, CA)

    2005-07-01

    Sandia's advanced computing resources provide researchers, engineers and analysts with the ability to develop and render highly detailed large-scale models and simulations. To take full advantage of these multi-million data point visualizations, display systems with comparable pixel counts are needed. The Interactive Design Center (IDC) is a second generation visualization theater designed to meet this need. The main display integrates twenty-seven projectors in a 9-wide by 3-high array with a total display resolution of more than 35 million pixels. Six individual SmartBoard displays offer interactive capabilities that include on-screen annotation and touch panel control of the facility's display systems. This report details the design, implementation and operation of this innovative facility.

  9. Intelligent Interactive Multimedia

    CERN Document Server

    Watanabe, Toyohide; Takahashi, Naohisa; 5th International Conference on Intelligent Interactive Multimedia Systems and Services

    2012-01-01

    This volume contains the Proceedings of the 5th International Conference on Intelligent Interactive Multimedia Systems and Services (KES-IIMSS-12).  The Conference was jointly organised by Nagoya University in Japan and the KES International organisation, and held in the attractive city of Gifu.   The KES-IIMSS conference series, (series chairs Prof. Maria Virvou and Prof. George Tsihrintzis), presents novel research in various areas of intelligent multimedia system relevant to the development of a new generation of interactive, user-centric devices and systems.  The aim of the conference is to provide an internationally respected forum for scientific research in the technologies and applications of this new and dynamic research area.

  10. Ligand-Receptor Interactions

    CERN Document Server

    Bongrand, Pierre

    2008-01-01

    The formation and dissociation of specific noncovalent interactions between a variety of macromolecules play a crucial role in the function of biological systems. During the last few years, three main lines of research led to a dramatic improvement of our understanding of these important phenomena. First, combination of genetic engineering and X ray cristallography made available a simultaneous knowledg of the precise structure and affinity of series or related ligand-receptor systems differing by a few well-defined atoms. Second, improvement of computer power and simulation techniques allowed extended exploration of the interaction of realistic macromolecules. Third, simultaneous development of a variety of techniques based on atomic force microscopy, hydrodynamic flow, biomembrane probes, optical tweezers, magnetic fields or flexible transducers yielded direct experimental information of the behavior of single ligand receptor bonds. At the same time, investigation of well defined cellular models raised the ...

  11. Ultrahigh energy neutrino interactions

    Science.gov (United States)

    Domokos, G.; Elliot, B.; Kovesi-Domokos, S.; Mrenna, S.

    1990-03-01

    Ultrahigh energy neutrinos are valuable probes of physics beyond the Standard Model. Neutrinos of the highest energies are emitted by point sources in the sky. We review briefly the predictions of the Standard Model concerning neutrino interactions. We further argue that a number of preon models designed to overcome some difficulties of the Standard Model leads to a blurring of the distinction between leptons and quarks. As a consequence, at sufficiently high energies neutrinos acquire ``anomalous'' interactions. While this phenomenon can probably explain the observed muon excess in extensive air showers (EAS), it can be also tested by studying the absorption of the primaries on the cosmic microwave background. We discuss some observations to be performed in the search of such ``new physics'' beyond the Standard Model.

  12. Interactional Expertise and Embodiment

    CERN Document Server

    Collins, Harry

    2016-01-01

    In Part 1 of this paper, I introduce the idea of interactional expertise while in Part 2, I focus on its implications for philosophical theories of the importance of the body in forming our conceptual world. I argue that the way philosophers have dealt with the body turns attention away from the most important questions and that we cannot answer these questions without making the notion of socialisation, and therefore interactional expertise, a central concept in our thinking. This makes language at least as important, and often more important than bodily practice in our understanding of the world. The notion of a disembodied socialised agent leads in the direction of interesting questions while the notion of an embodied but unsocialised human actor is unimaginable.

  13. Dynamics of interacting diseases

    CERN Document Server

    Sanz, Joaquín; Meloni, Sandro; Moreno, Yamir

    2014-01-01

    Current modeling of infectious diseases allows for the study of complex and realistic scenarios that go from the population to the individual level of description. Most epidemic models however assume that the spreading process takes place on a single level (be it a single population, a meta-population system or a network of contacts). The latter is in part a consequence of our still limited knowledge about the interdependency of the many mechanisms and factors involved in disease spreading. In particular, interdependent contagion phenomena can only be addressed if we go beyond the scheme one pathogen-one network. In this paper, we study a model that allows describing the spreading dynamics of two concurrent diseases and apply it to a paradigmatic case of disease-disease interaction: the interaction between AIDS and Tuberculosis. Specifically, we characterize analytically the epidemic thresholds of the two diseases for different scenarios and also compute the temporal evolution characterizing the unfolding dyn...

  14. Wood–water interactions

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2011-01-01

    Predicting the performance of wood for decades ahead is important when using the material for structural purposes. The performance is closely related to the hierarchical material structure of wood and the dependent interaction with water in the structure. Accurately predicting wood performance...... therefore requires an understanding of material structure from molecular to macroscopic level as well as of the impact of water molecules. The objective of this work is to investigate the performance of wood in terms of mechanical response of the material and effect of water. To understand the latter, one...... must first know in which parts of the wood structure, water is located. If parts of the water in wood are held in capillaries in the wood structure, these water molecules interact with the material differently than those held within wood cell walls. In this study, the occurrence of capillary water in...

  15. Interactive Chemical Reactivity Exploration

    CERN Document Server

    Haag, Moritz P; Bosson, Mael; Redon, Stephane; Reiher, Markus

    2014-01-01

    Elucidating chemical reactivity in complex molecular assemblies of a few hundred atoms is, despite the remarkable progress in quantum chemistry, still a major challenge. Black-box search methods to find intermediates and transition-state structures might fail in such situations because of the high-dimensionality of the potential energy surface. Here, we propose the concept of interactive chemical reactivity exploration to effectively introduce the chemist's intuition into the search process. We employ a haptic pointer device with force-feedback to allow the operator the direct manipulation of structures in three dimensions along with simultaneous perception of the quantum mechanical response upon structure modification as forces. We elaborate on the details of how such an interactive exploration should proceed and which technical difficulties need to be overcome. All reactivity-exploration concepts developed for this purpose have been implemented in the Samson programming environment.

  16. Theory of fundamental interactions

    International Nuclear Information System (INIS)

    In the present article the theory of fundamental interactions is derived in a systematic way from the first principles. In the developed theory there is no separation between space-time and internal gauge space. Main equations for basic fields are derived. In is shown that the theory satisfies the correspondence principle and gives rise to new notions in the considered region. In particular, the conclusion is made about the existence of particles which are characterized not only by the mass, spin, charge but also by the moment of inertia. These are rotating particles, the particles which represent the notion of the rigid body on the microscopical level and give the key for understanding strong interactions. The main concepts and dynamical laws for these particles are formulated. The basic principles of the theory may be examined experimentally not in the distant future. 29 refs

  17. Interactive Virtual Cinematography

    DEFF Research Database (Denmark)

    Burelli, Paolo

    A virtual camera represents the point-of-view of the player through which she perceives the game world and gets feedback on her actions. Thus, the virtual camera plays a vital role in 3D computer games and aects player experience and enjoyability in games. Interactive virtual cinematography....... The camera controller should dynamically and eciently translate these rules into camera positions and movements before (or while) the player plays the game. Automatically controlling the camera in virtual 3D dynamic environments is an open research problem and a challenging task. From an optimisation...... is the process of visualising the content of a virtual environment by positioning and animating the virtual camera in the context of interactive applications such as a computer game. Camera placement and animation in games are usually directly controlled by the player or statically predened by designers. Direct...

  18. Interacting Galaxies with MOND

    CERN Document Server

    Tiret, O

    2007-01-01

    We compare N-body simulations performed in MOND with analogs in Newtonian gravity with dark matter (DM). We have developed a code which solves the Poisson equation in both gravity models. It is a grid solver using adaptive mesh refinement techniques, allowing us to study isolated galaxies as well as interacting galaxies. Galaxies in MOND are found to form bars faster and stronger than in the DM model. In Newton dynamics, it is difficult to reproduce the observed high frequency of strong bars, while MOND appears to fit better the observations. Galaxy interactions and mergers, such as the Antennae, are also simulated with Newton and MOND dynamics. In the latter, dynamical friction is much weaker, and merging time-scales are longer. The formation of tidal dwarf galaxies in tidal tails are also compared in MOND and Newton+DM models.

  19. Interactive Information Retrieval

    DEFF Research Database (Denmark)

    Borlund, Pia

    2013-01-01

    The paper introduces the research area of interactive information retrieval (IIR) from a historical point of view. Further, the focus here is on evaluation, because much research in IR deals with IR evaluation methodology due to the core research interest in IR performance, system interaction...... and satisfaction with retrieved information. In order to position IIR evaluation, the Cranfield model and the series of tests that led to the Cranfield model are outlined. Three iconic user-oriented studies and projects that all have contributed to how IIR is perceived and understood today are presented....... As a response to this call the ‘IIR evaluation model’ by Borlund (e.g., 2003a) is introduced. The objective of the IIR evaluation model is to facilitate IIR evaluation as close as possible to actual information searching and IR processes, though still in a relatively controlled evaluation environment, in which...

  20. Plasmonic interaction between nanospheres

    CERN Document Server

    Yu, Sanghyeon

    2016-01-01

    When metallic nanospheres are nearly touching, strong nanofocusing of light can occur due to highly localized surface plasmons. It has potential applications in the design of nanophotonic devices, biosensing, and spectroscopy. Due to the singular behavior of electromagnetic fields in the narrow gap regions, its theoretical investigation is quite challenging in both analytical and numerical aspects. There are two approaches for studying the interaction between metallic spheres: transformation optics and the method of image charges. Here we clarify the connection between them. Based on the connection formula, we reveal the singular nature of plasmonic interaction between nanospheres in a completely analytical way. We also develop a hybrid numerical scheme for accurately and efficiently computing the field distribution produced by an arbitrary number of nearly touching plasmonic spheres.

  1. Magnetic interactions through fluoride

    DEFF Research Database (Denmark)

    Pedersen, Kasper Steen; Sigrist, Marc; Weihe, Høgni;

    2014-01-01

    The nature of the magnetic interaction through fluoride in a simple, dinuclear manganese(III) complex (1), bridged by a single fluoride ion in a perfectly linear fashion, is established by experiment and density functional theory. The magnitude of the antiferromagnetic exchange interaction...... and the manganese(III) zero-field-splitting parameters are unambiguously determined by inelastic neutron scattering to yield J = 33.0(2) cm(-1) (Ĥ = JŜ1·Ŝ2 Hamiltonian definition) and single-ion D = -4.0(1) cm(-1). Additionally, high-field, high-frequency electron paramagnetic resonance and magnetic measurements...... support the parameter values and resolve |E| ≈ 0.04 cm(-1). The exchange coupling constant (J) is 1 order of magnitude smaller than that found in comparable systems with linear oxide bridging but comparable to typical magnitudes through cyanide, thus underlining the potential of fluoride complexes...

  2. Interactive Chemical Reactivity Exploration

    OpenAIRE

    Haag, Moritz P.; Vaucher, Alain C.; Bosson, Mael; Redon, Stephane; Reiher, Markus

    2014-01-01

    Elucidating chemical reactivity in complex molecular assemblies of a few hundred atoms is, despite the remarkable progress in quantum chemistry, still a major challenge. Black-box search methods to find intermediates and transition-state structures might fail in such situations because of the high-dimensionality of the potential energy surface. Here, we propose the concept of interactive chemical reactivity exploration to effectively introduce the chemist's intuition into the search process. ...

  3. Interactive Video Search

    OpenAIRE

    Schoeffmann, Klaus; Hopfgartner, Frank

    2015-01-01

    With an increasing amount of video data in our daily life, the need for content-based search in videos increases as well. Though a lot of research has been spent on video retrieval tools and methods which allow for automatic search in videos through content-based queries, still the performance of automatic video retrieval is far from optimal. In this tutorial we discussed (i) proposed solutions for improved video content navigation, (ii) typical interaction of content-based querying features,...

  4. Identification of social interactions

    OpenAIRE

    Blume, Lawrence E.; William A Brock; Durlauf, Steven N.; Ioannides, Yannis M.

    2010-01-01

    Abstract: While interest in social determinants of individual behavior has led to a rich theoretical literature and many efforts to measure these influences, a mature "social econometrics" has yet to emerge. This chapter provides a critical overviewof the identification of social interactions. We consider linear and discrete choice models as well as social networks structures. We also consider experimental and quasi-experimental methods. In addition to describing the state of the identificati...

  5. Electric hydraulic interaction

    OpenAIRE

    Helle, Ola Høydal

    2011-01-01

    The hydraulic models representing hydro turbines and conduit system found instandard model libraries of power system analysis tools are often simplied mod-els. Subsequently, important information about the dynamics of the hydraulicsystem may not be properly represented by such models, putatively resultingin insucient representation of the interaction between the electric system andhydraulic system.In this master thesis three dierent hydraulic models for hydro power plantsequipped with Francis...

  6. Interactive Mediated Reality

    OpenAIRE

    Grasset, Raphaël; Boissieux, Laurence; Gascuel, Jean-Dominique; Schmalstieg, Dieter

    2005-01-01

    International audience Mediated reality describes the concept of filtering our vision of reality, typically using a head-mounted video mixing display. We can redefine this idea in a more constructive context, applying dynamic changes to the appearance and geometry of objects in a real scene using computer graphics. In this paper, we propose new tools for interactively mediated reality. After describing a new generic framework for achieving this goal, we present a prototype system for paint...

  7. Matrix string interactions

    OpenAIRE

    Periwal, Vipul; Tafjord, Oyvind

    1998-01-01

    String configurations have been identified in compactified Matrix theory at vanishing string coupling. We show how the interactions of these strings are determined by the Yang-Mills gauge field on the worldsheet. At finite string coupling, this suggests the underlying dynamics is not well-approximated as a theory of strings. This may explain why string perturbation theory diverges badly, while Matrix string perturbation theory presumably has a perturbative expansion with properties similar to...

  8. Vehicle-Pavement Interaction

    OpenAIRE

    Khavassefat, Parisa

    2014-01-01

    Several aspects of vehicle-pavement interaction have been studied and discussed in this thesis. Initially the pavement response is studied through a quasi-static and a dynamic computationally efficient framework under moving traffic loads. Subsequently, a non-stationary stochastic solution has been developed in order to account for the effect of pavement surface deterioration on pavement service life.The quasi-static procedure is based on a superposition principle and is computationally favou...

  9. Hydrophobic interaction chromatography

    OpenAIRE

    O'Connor, Brendan; Cummins, Phil

    2011-01-01

    Most proteins and large polypeptides have hydrophobic regions at their surface. These hydrophobic ‘patches’ are due to the presence of the side chains of hydrophobic or non-polar amino acids such as phenylalanine, tryptophan, alanine and methionine. These surface hydrophobic regions are interspersed between more hydrophilic or polar regions and the number, size and distribution of them is a specific characteristic of each protein. Hydrophobic Interaction Chromatography (HIC) is a commonly use...

  10. Interactions within wastewater systems

    OpenAIRE

    Langeveld, J.G.

    2004-01-01

    Wastewater systems consist of sewer systems and wastewater treatment works. As the performance of a wastewater treatment plant is affected by the characteristics, i.e. operation and design, of the contributing sewer systems, knowledge of the interactions between sewers and wastewater treatment works is very important when trying to understand and improve wastewater systems. The thesis comprises three main topics: Firstly, the sensitivity of wastewater treatment plant performance to influent f...

  11. Interactive tabletops in education

    OpenAIRE

    Dillenbourg, Pierre; Evans, Michael

    2011-01-01

    Interactive tabletops are gaining increased attention from CSCL researchers. This paper analyses the relation between this technology and teaching and learning processes. At a global level, one could argue that tabletops convey a socio-constructivist flavor: they support small teams that solve problems by exploring multiple solutions. The development of tabletop applications also witnesses the growing importance of face-to-face collaboration in CSCL and acknowledges the physicality of learnin...

  12. Interaction, Relationships And Networks

    OpenAIRE

    Benson-Rea, M

    1999-01-01

    This paper presents four case studies which have been selected to represent different insights into the strategic evaluation of relationships within one industry. From an analysis of how each of the case study firms has formed its networks of relationships, within its overall approach to industry strategy, we discuss how the interactions are evaluated, with a particular emergent focus on social or actor bonds. The strategy literature models strategy formation processes and content. The networ...

  13. Structural control interaction

    Science.gov (United States)

    Ryan, R. S.; Mowery, D. K.; Winder, S. W.; Worley, H. E.

    1973-01-01

    The basic guidance and control concepts that lead to structural control interaction and structural dynamic loads are identified. Space vehicle ascent flight load sources and the load relieving mechanism are discussed, along with the the characteristics and special problems of both present and future space vehicles including launch vehicles, orbiting vehicles, and the Space Shuttle flyback vehicle. The special dynamics and control analyses and test problems apparent at this time are summarized.

  14. Interactions faibles en harmonie

    CERN Multimedia

    1978-01-01

    Des résultats de haute précision obtenus à Stanford ouvrent la voie vers une unification des interactions faible et électromagnétique ; Présentation à la Conférence neutrino d'Oxford de nouveaux résultats en accord avec la théorie de la synthèse des forces faible et électro- magnétique

  15. Wave-Ice interaction

    Institute of Scientific and Technical Information of China (English)

    沈奚海莉

    2001-01-01

    The growth and movement of sea ice cover are influenced by the presence of wave field. Inturn, the wave field is influenced by the presence of ice cover. Their interaction is not fully understood.In this paper, we discuss some current understanding on wave attenuation when it propagates through frag-mented ice cover, ice drift due to the wave motion, and the growth characteristics of ice cover in wave field.

  16. Model of dynamic interactions

    OpenAIRE

    Klimchik, Alexandr; Pashkevich, Anatol; Caro, Stéphane

    2013-01-01

    In robotic-based machining, an interaction between the workpiece and technological tool causes essential deflections that significantly decrease the manufacturing accuracy. Relevant compliance errors highly depend on the manipulator configuration and essentially differ throughout the workspace. Their influence is especially important for heavy serial robots. To overcome this difficulty this report presents a new technique for compensation of the compliance errors caused by technological proce...

  17. Strangeness in hadronic interactions

    CERN Document Server

    Paul, S

    2000-01-01

    Strangeness has always been an important subject at all PANIC conferences as it probably constitutes the best link between particle and nuclear physics. I will thus use the theme of the conference by considering strangeness as a tourist through the world of strong interaction. During this talk we will accompany strangeness from production, to the royaume of mesons and baryons up to the complex world of nuclei.

  18. ELEMENTARY PARTICLE INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    EFREMENKO, YURI; HANDLER, THOMAS; KAMYSHKOV, YURI; SIOPSIS, GEORGE; SPANIER, STEFAN

    2013-07-30

    The High-Energy Elementary Particle Interactions group at UT during the last three years worked on the following directions and projects: Collider-based Particle Physics; Neutrino Physics, particularly participation in “NOνA”, “Double Chooz”, and “KamLAND” neutrino experiments; and Theory, including Scattering amplitudes, Quark-gluon plasma; Holographic cosmology; Holographic superconductors; Charge density waves; Striped superconductors; and Holographic FFLO states.

  19. Antinucleon-nucleus interactions

    Energy Technology Data Exchange (ETDEWEB)

    Dover, C.B.

    1987-01-01

    Recent experimental and theoretical results on anti p-nucleus interactions are reviewed. We focus on determinations of the anti p optical potential from elastic scattering, the use of (anti p, anti p') inelastic scattering to reveal aspects of the spin-isospin dependence of N anti N amplitudes, and some puzzling features of (anti p, anti n) charge exchange reactions on nuclei. 47 refs., 7 figs.

  20. Pharmacokinetic interactions with thiazolidinediones.

    Science.gov (United States)

    Scheen, André J

    2007-01-01

    Type 2 diabetes mellitus is a complex disease combining defects in insulin secretion and insulin action. New compounds called thiazolidinediones or glitazones have been developed for reducing insulin resistance. After the withdrawal of troglitazone because of liver toxicity, two compounds are currently used in clinical practice, rosiglitazone and pioglitazone. These compounds are generally used in combination with other pharmacological agents. Because they are metabolised via cytochrome P450 (CYP), glitazones are exposed to numerous pharmacokinetic interactions. CYP2C8 and CYP3A4 are the main isoenzymes catalysing biotransformation of pioglitazone (as with troglitazone), whereas rosiglitazone is metabolised by CYP2C9 and CYP2C8. For both rosiglitazone and pioglitazone, the most relevant interactions have been described in healthy volunteers with rifampicin (rifampin), which results in a significant decrease of area under the plasma concentration-time curve [AUC] (54-65% for rosiglitazone, p<0.001; 54% for pioglitazone, p<0.001), and with gemfibrozil, which results in a significant increase of AUC (130% for rosiglitazone, p<0.001; 220-240% for pioglitazone, p<0.001). The relevance of such drug-drug interactions in patients with type 2 diabetes remains to be evaluated. However, in the absence of clinical data, it is prudent to reduce the dosage of each glitazone by half in patients treated with gemfibrozil. Conversely, rosiglitazone and pioglitazone do not seem to significantly affect the pharmacokinetics of other compounds. Although some food components have also been shown to potentially interfere with drugs metabolised with the CYP system, no published study deals specifically with these possible CYP-mediated food-drug interactions with glitazones.

  1. Protein-protein interactions

    DEFF Research Database (Denmark)

    Byron, Olwyn; Vestergaard, Bente

    2015-01-01

    . The biophysical and structural investigations of PPIs consequently demand hybrid approaches, implementing orthogonal methods and strategies for global data analysis. Currently, impressive developments in hardware and software within several methodologies define a new era for the biostructural community. Data can......Responsive formation of protein:protein interaction (PPI) upon diverse stimuli is a fundament of cellular function. As a consequence, PPIs are complex, adaptive entities, and exist in structurally heterogeneous interplays defined by the energetic states of the free and complexed protomers...

  2. Moxifloxacin-warfarin interaction

    Directory of Open Access Journals (Sweden)

    Yan Ji

    2012-01-01

    Full Text Available Two case reports presented here show elevated prothrombin time/international normalized ratios (PT/INR following coadministration of warfarin and moxifloxacin. Although the underlying mechanism of this interaction still remains unclear, health care providers should be careful when prescribing moxifloxacin to patients on warfarin therapy, especially to patients with low albumin levels. More frequent monitoring of INR in these patients may be warranted.

  3. Moxifloxacin-warfarin interaction

    OpenAIRE

    Ji, Yan; Hokayem, Youssef

    2012-01-01

    Two case reports presented here show elevated prothrombin time/international normalized ratios (PT/INR) following coadministration of warfarin and moxifloxacin. Although the underlying mechanism of this interaction still remains unclear, health care providers should be careful when prescribing moxifloxacin to patients on warfarin therapy, especially to patients with low albumin levels. More frequent monitoring of INR in these patients may be warranted.Keywords: warfarin; moxifloxacin; PT/INR;...

  4. Orbital interactions in chemistry

    CERN Document Server

    Albright, Thomas A; Whangbo, Myung-Hwan

    2013-01-01

    Explains the underlying structure that unites all disciplines in chemistry Now in its second edition, this book explores organic, organometallic, inorganic, solid state, and materials chemistry, demonstrating how common molecular orbital situations arise throughout the whole chemical spectrum. The authors explore the relationships that enable readers to grasp the theory that underlies and connects traditional fields of study within chemistry, thereby providing a conceptual framework with which to think about chemical structure and reactivity problems. Orbital Interactions

  5. Interactive Submodular Set Cover

    CERN Document Server

    Guillory, Andrew

    2010-01-01

    We introduce a natural generalization of submodular set cover and exact active learning with a finite hypothesis class (query learning). We call this new problem interactive submodular set cover. Applications include advertising in social networks with hidden information. We give an approximation guarantee for a greedy algorithm and give a hardness of approximation result which matches up to constant factors. We also discuss the adaptivity gap for the problem and present encouraging early experimental results.

  6. Renormalizability and nonrenormalizable interactions

    Institute of Scientific and Technical Information of China (English)

    YAO Hai-Bo; WU Shi-Shu

    2009-01-01

    Arguments are provided which show that extension of renormalizability in quantum field theory is possible. By an appropriate choice of effective Lagrangian, a dressed Feynman propagator is obtained. In this scheme, higher order Feynman diagrams become self-convergent and nonrenormalizable interactions become renormalizable. As an example, the vacuum fluctuation effects on p meson mass for the vector-tensor coupling model is discussed. It is found that the result can agree with the experimental value when coupling constant is adjusted.

  7. Neutrino Interactions with Nuclei

    CERN Document Server

    Leitner, T; Mosel, U; Alvarez-Ruso, L

    2007-01-01

    We investigate neutrino-nucleus collisions at intermediate energies incorporating quasi-elastic scattering and the excitation of 13 resonances as elementary processes, taking into account medium effects such as Fermi motion, Pauli blocking, mean-field potentials and in-medium spectral functions. A coupled-channel treatment of final state interactions is achieved with the GiBUU transport model. Results for inclusive reactions, neutrino- and electron-induced, as well as for pion production and nucleon knockout are presented.

  8. Transactional interactive multimedia banner

    Science.gov (United States)

    Shae, Zon-Yin; Wang, Xiping; von Kaenel, Juerg

    2000-05-01

    Advertising in TV broadcasting has shown that multimedia is a very effective means to present merchandise and attract shoppers. This has been applied to the Web by including animated multimedia banner ads on web pages. However, the issues of coupling interactive browsing, shopping, and secure transactions e.g. from inside a multimedia banner, have only recently started to being explored. Currently there is an explosively growing amount of back-end services available (e.g., business to business commerce (B2B), business to consumer (B2C) commerce, and infomercial services) in the Internet. These services are mostly accessible through static HTML web pages at a few specific web portals. In this paper, we will investigate the feasibility of using interactive multimedia banners as pervasive access point for the B2C, B2B, and infomercial services. We present a system architecture that involves a layer of middleware agents functioning as the bridge between the interactive multimedia banners and back-end services.

  9. Web Interactive Campus Map

    Directory of Open Access Journals (Sweden)

    Marylene S. Eder

    2015-03-01

    Full Text Available Abstract Interactive campus map is a web based application that can be accessed through a web browser. With the Google Map Application Programming Interface availability of the overlay function has been taken advantage to create custom map functionalities. Collection of building points were gathered for routing and to create polygons which serves as a representation of each building. The previous campus map provides a static visual representation of the campus. It uses legends building name and its corresponding building number in providing information. Due to its limited capabilities it became a realization to the researchers to create an interactive campus map.Storing data about the building room and staff information and university events and campus guide are among the primary features that this study has to offer. Interactive Web-based Campus Information System is intended in providing a Campus Information System.It is open to constant updates user-friendly for both trained and untrained users and capable of responding to all needs of users and carrying out analyses. Based on the data gathered through questionnaires researchers analyzed the results of the test survey and proved that the system is user friendly deliver information to users and the important features that the students expect.

  10. Campylobacter-Acanthamoeba interactions.

    Science.gov (United States)

    Vieira, Ana; Seddon, Alan M; Karlyshev, Andrey V

    2015-05-01

    Campylobacter jejuni is a foodborne pathogen recognized as the major cause of human bacterial enteritis. Undercooked poultry products and contaminated water are considered as the most important sources of infection. Some studies suggest transmission and survival of this bacterial pathogen may be assisted by the free-living protozoa Acanthamoeba. The latter is known to play the role of a host for various pathogenic bacteria, protecting them from harsh environmental conditions. Importantly, there is a similarity between the mechanisms of bacterial survival within amoebae and macrophages, making the former a convenient tool for the investigation of the survival of pathogenic bacteria in the environment. However, the molecular mechanisms involved in the interaction between Campylobacter and Acanthamoeba are not well understood. Whilst some studies suggest the ability of C. jejuni to survive within the protozoa, the other reports support an extracellular mode of survival only. In this review, we focus on the studies investigating the interaction between Campylobacter and Acanthamoeba, address some reasons for the contradictory results, and discuss possible implications of these results for epidemiology. Additionally, as the molecular mechanisms involved remain unknown, we also suggest possible factors that may be involved in this process. Deciphering the molecular mechanisms of pathogen-protozoa interaction will assist in a better understanding of Campylobacter lifestyle and in the development of novel antibacterial drugs.

  11. Intercultural Interaction and Handicrafts

    Directory of Open Access Journals (Sweden)

    Mine CAN

    2015-07-01

    Full Text Available Technological developments in the world since the mid - 20th century, has increased intercultural communication and the whole world today has been informed of the existence of societies even in the most remote corners of the world. With increase in globaliza tion in cultural context, the importance of local differences has emerged more today. As a result, a process has initiated in which the similarities with differences, localization with the universalization and modernization with the tradition experienced s imutaneously and intercultural interaction has become inevitable and a natural phenomenon. However, handicrafts has been affected by cultural interactions negatively and the mistakes done caused the national culture and identities to weaken. For this reaso n, the necessity of experience of changing and developing in the frame of development with identity, transformation and cultural heritage today is emphasized. To be protected from the negative effects of the global interaction, many government produce prot ection and sustenance contracts, laws and projects by engaging in various initiatives. In the study, subjects is discussed with the examples of successful countries that aim to promote their local cultures globally and provide income.

  12. Interacting Multiview Tracker.

    Science.gov (United States)

    Yoon, Ju Hong; Yang, Ming-Hsuan; Yoon, Kuk-Jin

    2016-05-01

    A robust algorithm is proposed for tracking a target object in dynamic conditions including motion blurs, illumination changes, pose variations, and occlusions. To cope with these challenging factors, multiple trackers based on different feature representations are integrated within a probabilistic framework. Each view of the proposed multiview (multi-channel) feature learning algorithm is concerned with one particular feature representation of a target object from which a tracker is developed with different levels of reliability. With the multiple trackers, the proposed algorithm exploits tracker interaction and selection for robust tracking performance. In the tracker interaction, a transition probability matrix is used to estimate dependencies between trackers. Multiple trackers communicate with each other by sharing information of sample distributions. The tracker selection process determines the most reliable tracker with the highest probability. To account for object appearance changes, the transition probability matrix and tracker probability are updated in a recursive Bayesian framework by reflecting the tracker reliability measured by a robust tracker likelihood function that learns to account for both transient and stable appearance changes. Experimental results on benchmark datasets demonstrate that the proposed interacting multiview algorithm performs robustly and favorably against state-of-the-art methods in terms of several quantitative metrics. PMID:26336117

  13. Effect of the β-propiolactone treatment on the adsorption and fusion of influenza A/Brisbane/59/2007 and A/New Caledonia/20/1999 virus H1N1 on a dimyristoylphosphatidylcholine/ganglioside GM3 mixed phospholipids monolayer at the air-water interface.

    Science.gov (United States)

    Desbat, Bernard; Lancelot, Eloïse; Krell, Tino; Nicolaï, Marie-Claire; Vogel, Fred; Chevalier, Michel; Ronzon, Frédéric

    2011-11-15

    The production protocol of many whole cell/virion vaccines involves an inactivation step with β-propiolactone (BPL). Despite the widespread use of BPL, its mechanism of action is poorly understood. Earlier work demonstrated that BPL alkylates nucleotide bases, but its interaction with proteins has not been studied in depth. In the present study we use ellipsometry to analyze the influence of BPL treatment of two H1N1 influenza strains, A/Brisbane/59/2007 and A/New Caledonia/20/1999, which are used for vaccine production on an industrial scale. Analyses were conducted using a mixed lipid monolayer containing ganglioside GM3, which functions as the viral receptor. Our results show that BPL treatment of both strains reduces viral affinity for the mixed monolayer and also diminishes the capacity of viral domains to self-assemble. In another series of experiments, the pH of the subphase was reduced from 7.4 to 5 to provoke the pH-induced conformational change of hemagglutinin, which occurs following endocytosis into the endosome. In the presence of the native virus the pH decrease caused a reduction in domain size, whereas lipid layer thickness and surface pressure were increased. These observations are consistent with a fusion of the viral membrane with the lipid monolayer. Importantly, this fusion was not observed with adsorbed inactivated virus, which indicates that BPL treatment inhibits the first step of virus-membrane fusion. Our data also indicate that BPL chemically modifies hemagglutinin, which mediates the interaction with GM3.

  14. Trapped Three Interacting Bosons with a Short-Ranged Interaction

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2006-01-01

    A system of three bosons trapped by a parabolic confinement and interacting with a short-ranged interaction has been investigated by the exact diagonalization of the Hamiltonian matrix. We report a calculation for the energy spectrum of the low-lying states of a system of three interacting bosons. The important feature of the low-lying states of three interacting bosons trapped by a parabolic confinement is obtained via an analysis of the energy spectrum.

  15. Embodying multilingual interaction

    DEFF Research Database (Denmark)

    Hazel, Spencer; Mortensen, Janus

    program at a Danish university. Due to the peripheral institutional status of this site, institutionally implemented regulations and norms of conduct, including norms related to language choice, are less formalized here than in classroom, library or office settings. One of the consequences of this status...... features contribute to the situated meaning potential of language choice and language alternation. Only in the combined analysis of these diverse interactional resources are we able to build grounded interpretations of how practices of language choice and alternation are brought about and understood...

  16. Interaction, transference, and subjectivity

    DEFF Research Database (Denmark)

    Lundgaard Andersen, Linda

    2012-01-01

    is also subjected to psychodynamic processes. In this article, I draw upon a number of research inquiries to illustrate how psychodynamic processes influence research processes: data production, research questions and methodology, relations to informants, as well as interpretation and analysis. I further...... are important filters for fieldwork. In general, fieldwork can be understood as processes where field reports and field analysis are determined by how the researcher interacts with and experiences the field, the events and informants in it, and how she subsequently develops an ethnography. However, fieldwork...

  17. Human Work Interaction Design

    DEFF Research Database (Denmark)

    Gonçalves, Frederica; Campos, Pedro; Clemmensen, Torkil

    2015-01-01

    In this paper, we review research in the emerging practice and research field of Human Work Interaction Design (HWID). We present a HWID framework, and a sample of 54 HWID related papers from workshops, conferences and journals from the period 2009–2014. We group the papers into six topical groups......, and then attempt to map these groups to the framework to find research gaps for future research. We find that the groups of papers cover all areas of the framework well for a variety of work and leisure domains. The area in strongest need for more research papers is the development of the holistic framework itself...

  18. Human Work Interaction Design

    DEFF Research Database (Denmark)

    Gonçalves, Frederica; Campos, Pedro; Clemmensen, Torkil

    2015-01-01

    In this paper, we review research in the emerging practice and research field of Human Work Interaction Design (HWID). We present a HWID frame-work, and a sample of 54 papers from workshops, conferences and journals from the period 2009-2014. We group the papers into six topical groups, and then at......-tempt to map these groups to the framework to find research gaps for future re-search. We find that the groups of papers cover all areas of the framework well for a variety of work and leisure domains. The area in strongest need for more research papers is the development of the holistic framework itself...

  19. Drugging Membrane Protein Interactions.

    Science.gov (United States)

    Yin, Hang; Flynn, Aaron D

    2016-07-11

    The majority of therapeutics target membrane proteins, accessible on the surface of cells, to alter cellular signaling. Cells use membrane proteins to transduce signals into cells, transport ions and molecules, bind cells to a surface or substrate, and catalyze reactions. Newly devised technologies allow us to drug conventionally "undruggable" regions of membrane proteins, enabling modulation of protein-protein, protein-lipid, and protein-nucleic acid interactions. In this review, we survey the state of the art of high-throughput screening and rational design in drug discovery, and we evaluate the advances in biological understanding and technological capacity that will drive pharmacotherapy forward against unorthodox membrane protein targets. PMID:26863923

  20. Interacting Galaxies with MOND

    OpenAIRE

    Tiret, O; Combes, F

    2007-01-01

    We compare N-body simulations performed in MOND with analogs in Newtonian gravity with dark matter (DM). We have developed a code which solves the Poisson equation in both gravity models. It is a grid solver using adaptive mesh refinement techniques, allowing us to study isolated galaxies as well as interacting galaxies. Galaxies in MOND are found to form bars faster and stronger than in the DM model. In Newton dynamics, it is difficult to reproduce the observed high frequency of strong bars,...

  1. Scattering with absorptive interaction

    Science.gov (United States)

    Cassing, W.; Stingl, M.; Weiguny, A.

    1982-07-01

    The S matrix for a wide class of complex and nonlocal potentials is studied, with special attention given to the motion of singularities in the complex k plane as a function of the imaginary coupling strength. Modifications of Levinson's theorem are obtained and discussed. Analytic approximations to the S matrix in the vicinity of narrow resonances are exhibited and compared to numerical results of resonating-group calculations. The problem of defining resonances in the case of complex interactions is discussed, making contact with the usual analysis of scattering in terms of Argand diagrams. NUCLEAR REACTIONS Scattering theory, S matrix for absorptive potentials.

  2. Virtual Interactive Space (VIS)

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2015-01-01

    This paper shares code that enables the making of a Virtual Interactive Space (VIS) where the skin of the invisible active sensor area is dynamically responsive to the velocity of a limb e.g. hand. Used in proprioception training of movement the patch is at the core of the author’s Reafferentation...... concept, which takes advantage of human natural and unconscious capacity. The mapping of the patch to a sound (e.g. drum, thus realizing an ‘air-drum’) resulted in increased client engagement in physiotherapist-led movement training sessions. The paper also reflects on how a cable-less physical...

  3. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    The objective of our theoretical research under this grant over the past 3 years was to develop new understanding in a range of topics in the physics of dust-plasma interactions, with application to space and the laboratory. We conducted studies related to the physical properties of dust, waves and instabilities in both weakly coupled and strongly coupled dusty plasmas, and innovative possible applications. A major consideration in our choice of topics was to compare theory with experiments or observations, and to motivate new experiments, which we believe is important for developing this relatively new field. Our research is summarized, with reference to our list of journal publications.

  4. Flavivirus-Mosquito Interactions

    Directory of Open Access Journals (Sweden)

    Yan-Jang S. Huang

    2014-11-01

    Full Text Available The Flavivirus genus is in the family Flaviviridae and is comprised of more than 70 viruses. These viruses have a broad geographic range, circulating on every continent except Antarctica. Mosquito-borne flaviviruses, such as yellow fever virus, dengue virus serotypes 1–4, Japanese encephalitis virus, and West Nile virus are responsible for significant human morbidity and mortality in affected regions. This review focuses on what is known about flavivirus-mosquito interactions and presents key data collected from the field and laboratory-based molecular and ultrastructural evaluations.

  5. Interactive Architecture #1

    OpenAIRE

    Oosterhuis, K.; X. Xia

    2007-01-01

    The iA bookzine series will consist of twelve issues, bi-annually published over a period of six years under the supervision of Prof. ir. Kas Oosterhuis, director of the Hperbody at the Delft University of Technology. Interactive Architecture - from here on abbreviated as iA - is NOT simply architecture that is responsive or adaptive to changing circumstances. On the contrary, iA is based on the concept of bi-directional communication, which requires two active parties. Naturally, communicati...

  6. Student interaction in workshops

    DEFF Research Database (Denmark)

    Evers, Winie

    2014-01-01

    to experiment with novel workshop methods and techniques, where objects are used to illustrate and model business issues (Heinemann et al, 2011, Buur et al, 2013). The idea was to see how students could be engaged in a different and more interactive way to learn about these topics, by assigning the students...... a task of modeling the dynamics of a firm’s supply chain. Following Gardner’s theory of multiple intelligences (1983), it is argued that each learner possesses a unique blend of diverse intelligences, and should therefore empower learners, rather than restrict them to a single modality. Consequently...

  7. Visuo-Vestibular Interactions

    Science.gov (United States)

    1997-01-01

    Session TA3 includes short reports covering: (1) Vestibulo-Oculomotor Interaction in Long-Term Microgravity; (2) Effects of Weightlessness on the Spatial Orientation of Visually Induced Eye Movements; (3) Adaptive Modification of the Three-Dimensional Vestibulo-Ocular Reflex during Prolonged Microgravity; (4) The Dynamic Change of Brain Potential Related to Selective Attention to Visual Signals from Left and Right Visual Fields; (5) Locomotor Errors Caused by Vestibular Suppression; and (6) A Novel, Image-Based Technique for Three-Dimensional Eye Measurement.

  8. The Interactive Zoooz Guide

    Directory of Open Access Journals (Sweden)

    Thang Nguyen

    2010-12-01

    Full Text Available GPS (Global Positioning System technology is widely known for its ability to track down devices in real time. Combined with mobile phones, it has become a very powerful tool with a great potential for future development of mobile GPS applications. The Interactive ZooOz Guide was a final year industry project carried out by seven students from three separate courses to tackle a project that involves upgrading the Melbourne Zoo’s mapping system through the use of GPS technology. The aim of the project is to explorethe potential capability of using GPS in the Zoo environment. The proposed system uses a PDA device with a GPS receiver that tracks users’ location in real time as they are touring around the Zoo. In this paper, an insight into GPS technology is briefly reviewed and the design and implementation of “Interactive ZooOZ Guide” is described. Then GUI (Graphical User Interface is presented in detail. Finally conclusion is drawn from the “proof of concept” prototype.

  9. Interactive fundamental physics

    International Nuclear Information System (INIS)

    THE REAL STUFF is an Expanded Media Physics Course aimed at students still in the formative early years of secondary school. Its consists of a working script for an interactive multimedia study unit in basic concepts of physics. The unit begins with a prologue on the Big Bang that sets the stage, and concludes with a lesson on Newton's first law of motion. The format is interactive, placing the individual student in control of a layered ''hypermedia'' structure that enables him or her to find a level of detail and difficulty that is comfortable and meaningful. The intent is to make physics relevant, intellectually accessible and fun. On-screen presenters and demonstrators will be females and males of various ages, ethnicities and backgrounds, and will include celebrities and physicists of note. A lean, layered design encourages repeated, cumulative study and makes the material useful for self-directed Teaming even by college students. THE REAL STUFF introduces a new science teaching paradigm, a way to teach science that will engage even students who have ''declined'' to be interested in science in the past. Increased participation in science by women, African-Americans and Spanish-speaking students is a particular goal

  10. JSPAM: Interacting galaxies modeller

    Science.gov (United States)

    Wallin, John F.; Holincheck, Anthony; Harvey, Allen

    2015-11-01

    JSPAM models galaxy collisions using a restricted n-body approach to speed up computation. Instead of using a softened point-mass potential, the software supports a modified version of the three component potential created by Hernquist (1994, ApJS 86, 389). Although spherically symmetric gravitationally potentials and a Gaussian model for the bulge are used to increase computational efficiency, the potential mimics that of a fully consistent n-body model of a galaxy. Dynamical friction has been implemented in the code to improve the accuracy of close approaches between galaxies. Simulations using this code using thousands of particles over the typical interaction times of a galaxy interaction take a few seconds on modern desktop workstations, making it ideal for rapidly prototyping the dynamics of colliding galaxies. Extensive testing of the code has shown that it produces nearly identical tidal features to those from hierarchical tree codes such as Gadget but using a fraction of the computational resources. This code was used in the Galaxy Zoo: Mergers project and is very well suited for automated fitting of galaxy mergers with automated pattern fitting approaches such as genetic algorithms. Java and Fortran versions of the code are available.

  11. XEphem: Interactive Astronomical Ephemeris

    Science.gov (United States)

    Downey, Elwood Charles

    2011-12-01

    XEphem is a scientific-grade interactive astronomical ephemeris package for UNIX-like systems. Written in C, X11 and Motif, it is easily ported to systems. Among other things, XEphem: computes heliocentric, geocentric and topocentric information for all objects; has built-in support for all planets; the moons of Mars, Jupiter, Saturn, Uranus and Earth; central meridian longitude of Mars and Jupiter; Saturn's rings; and Jupiter's Great Red Spot; allows user-defined objects including stars, deepsky objects, asteroids, comets and Earth satellites; provides special efficient handling of large catalogs including Tycho, Hipparcos, GSC; displays data in configurable tabular formats in conjunction with several interactive graphical views; displays a night-at-a-glance 24 hour graphic showing when any selected objects are up; displays 3-D stereo Solar System views that are particularly well suited for visualizing comet trajectories; quickly finds all close pairs of objects in the sky; and sorts and prints all catalogs with very flexible criteria for creating custom observing lists. Its capabilities are listed more fully in the user manual introduction.

  12. Cardiolipin Interactions with Proteins.

    Science.gov (United States)

    Planas-Iglesias, Joan; Dwarakanath, Himal; Mohammadyani, Dariush; Yanamala, Naveena; Kagan, Valerian E; Klein-Seetharaman, Judith

    2015-09-15

    Cardiolipins (CL) represent unique phospholipids of bacteria and eukaryotic mitochondria with four acyl chains and two phosphate groups that have been implicated in numerous functions from energy metabolism to apoptosis. Many proteins are known to interact with CL, and several cocrystal structures of protein-CL complexes exist. In this work, we describe the collection of the first systematic and, to the best of our knowledge, the comprehensive gold standard data set of all known CL-binding proteins. There are 62 proteins in this data set, 21 of which have nonredundant crystal structures with bound CL molecules available. Using binding patch analysis of amino acid frequencies, secondary structures and loop supersecondary structures considering phosphate and acyl chain binding regions together and separately, we gained a detailed understanding of the general structural and dynamic features involved in CL binding to proteins. Exhaustive docking of CL to all known structures of proteins experimentally shown to interact with CL demonstrated the validity of the docking approach, and provides a rich source of information for experimentalists who may wish to validate predictions.

  13. Microbiome and immunological interactions.

    Science.gov (United States)

    Kelly, Denise; Mulder, Imke E

    2012-08-01

    The healthy human gut supports a complex and diverse microbiota, dominated by bacterial phylotypes belonging to Bacteroidetes and Firmicutes. In the inflamed gut, overall diversity decreases, coincident with a greater representation of Proteobacteria. There is growing evidence supporting an important role for human gut bacteria in mucosal immunity; interactions at the level of both intestinal and colonic epithelial cells, dendritic cells, and T and B immune cells have been documented. These interactions influence gut barrier and defense mechanisms that include antimicrobial peptide and secretory IgA synthesis. The functional effects of commensal bacteria on T helper cell differentiation have led to the emerging concept that microbiota composition determines T effector- and T regulatory-cell balance, immune responsiveness, and homeostasis. The importance of this biology in relation to immune homeostasis, inflammatory bowel disease, and the rising incidence of autoimmune diseases will be discussed. The detailed description of the human gut microbiota, integrated with evidence-based mechanisms of immune modulation, provides an exciting platform for the identification of next-generation probiotics and related pharmaceutical products. PMID:22861803

  14. Interaction in English Classroom Teaching

    Institute of Scientific and Technical Information of China (English)

    金晶

    2009-01-01

    This essay mainly elaborates on the interaction in English classroom teaching.It highlights the indispensable role interaction should play in teaching process.and give out a series of methods on how to promote the application of this strategy.

  15. Interaction of open graphic dynamics

    OpenAIRE

    Dugowson, Stéphane

    2015-01-01

    The aim of this paper is to define what we shall call open graphic dynamics, their interactions and the dynamics produced by those interactions. It prepares the study of "open sub-categorical dynamics" and "open categorical dynamics".

  16. User producer interaction in context

    NARCIS (Netherlands)

    Nahuis, R.; Moors, E.H.M.; Smits, R.E.H.M.

    2012-01-01

    User producer interaction (UPI) increases chances for successful innovations. It is not always clear, however, what type of interaction is necessary in a particular context. This article identifies seven different types of UPI: constructing linkages, broadening, characterizing users, upstream involv

  17. Hydrophobic interactions and chemical reactivity

    NARCIS (Netherlands)

    Otto, Sijbren; Engberts, Jan B.F.N.

    2003-01-01

    This perspective describes how kinetic studies of organic reactions can be used to increase our understanding of hydrophobic interactions. In turn, our understanding of hydrophobic interactions can be used as a tool to influence chemical reactions.

  18. Interactive Parallel and Distributed Processing

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Pagliarini, Luigi

    2010-01-01

    We present the concept of interactive parallel and distributed processing, and the challenges that programmers face in designing interactive parallel and distributed systems. Specifically, we introduce the challenges that are met and the decisions that need to be taken with respect...... to implement interactive parallel and distributed processing with different software behavioural models such as open loop, randomness based, rule based, user interaction based, AI and ALife based software....

  19. The Discipline of Interactive Sonification

    OpenAIRE

    Hermann, Thomas; Hunt, Andy

    2004-01-01

    This paper argues for a special focus on the use of dynamic human interaction to explore datasets while they are being transformed into sound. We describe why this is a special case of both human computer interaction (HCI) techniques and sonification methods. Humans are adapted for interacting with their physical environment and making continuous use of all their senses. When this exploratory interaction is applied to a dataset (by continuously controlling its transformation into sound) new i...

  20. MINT: the Molecular INTeraction database

    OpenAIRE

    Chatr-aryamontri, Andrew; Ceol, Arnaud; Palazzi, Luisa Montecchi; Nardelli, Giuliano; Schneider, Maria Victoria; Castagnoli, Luisa; Cesareni, Gianni

    2006-01-01

    The Molecular INTeraction database (MINT, ) aims at storing, in a structured format, information about molecular interactions (MIs) by extracting experimental details from work published in peer-reviewed journals. At present the MINT team focuses the curation work on physical interactions between proteins. Genetic or computationally inferred interactions are not included in the database. Over the past four years MINT has undergone extensive revision. The new version of MINT is based on a comp...