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1

Application aux modles multi-chelle de turbulence  

E-print Network

231 Chapitre 4 Application aux modèles multi-échelle de turbulence compressible homogène isotrope L'objectif des rappels sur les écoulements compressibles tur- bulents, l'objectif étant de situer les modèles forte dépendance par rap- port à la condition initiale et aux conditions aux limites. Par ailleurs, la

Chalons, Christophe

2

Engineering evaluation of solids/liquids separation processes applicable to sludge treatment project  

SciTech Connect

This engineering study looks at the solids/liquids separation unit operations after the acid dissolution of the K Basin sludge treatment. Unit operations considered were centrifugation, filtration (cartridge, cross flow, and high shear filtration) and gravity settling. The recommended unit operations for the solids/liquids separations are based upon the efficiency, complexity, and off-the-shelf availability and adaptability. The unit operations recommended were a Robatel DPC 900 centrifuge followed by a nuclearized 31WM cartridge filter. The Robatel DPC 900 has been successfully employed in the nuclear industry on a world wide scale. The 31WM cartridge filter has been employed for filtration campaigns in both the government and civilian nuclear arenas.

Duncan, J.B.

1998-08-25

3

Solids, Liquids, and Gases  

NSDL National Science Digital Library

In this project you will research solids, liquids, and gases. By the end of this project you will be able to answer the question: Can you tell what is alike and different between solids, liquids, and gases? Read the song about matter. song with music about matter Record your observations on the organizer provided by the teacher. On the diagram write the word solid in one of the circles. Write liquid in one of the circles and write gas in the last circle. As you collect your information write your information under ...

Sibley, Ms.

2009-10-22

4

Solid, Liquid or Gas?  

NSDL National Science Digital Library

Students are given a variety of materials and asked to identify if each material as a solid, liquid or gas. They use their five senses sight, sound, smell, texture and taste to identify the other characteristics of each item.

Integrated Teaching And Learning Program

5

APPLICATION DES PALIERS A GAZ AUX GYROSCOPES Par G. GOBERT,  

E-print Network

43 APPLICATION DES PALIERS A GAZ AUX GYROSCOPES Par G. GOBERT, Centre d'?tudes Nucléaires de Saclay gyroscope dont le rotor de 4 cm de diamètre pesant plusieurs centaines de grammes tourne à une vitesse to the construction of a gyroscope. The rotor is 4 cm in diameter and runs at 180 000 r. p. m. Its weight is 500 g. LE

Paris-Sud XI, Université de

6

Advances in solid-liquid separation  

SciTech Connect

New developments are discussed in the areas of flocculation and coagulation, on-line flocculant control systems, membranes for solid-liquid separation, cake deliquoring, and filtration theory and models. The book shows how the application of ultrasonic, magnetic, and electric field forces to the solid or liquid or the interface can result in greater product recovery, decreased energy costs, higher solids product, and lower transportation costs.

Muralidhara, H.S.

1986-01-01

7

Granular solids, liquids, and gases  

Microsoft Academic Search

Granular materials are ubiquitous in the world around us. They have properties that are different from those commonly associated with either solids, liquids, or gases. In this review the authors select some of the special properties of granular materials and describe recent research developments. {copyright} {ital 1996 The American Physical Society.}

Heinrich M. Jaeger; Sidney R. Nagel; Robert P. Behringer

1996-01-01

8

Calculation of multicomponent chemical equilibria in gas-solid-liquid systems: Calculation methods, thermochemical data, and applications to studies of high-temperature volcanic gases with examples from Mt. St. Helens  

Microsoft Academic Search

This paper documents the numerical formulations, thermochemical data base, and possible applications of computer programs, SOLVGAS and GASWORKS, for calculating multicomponent chemical equilibria in gas-solid-liquid systems. SOLVGAS and GASWORKS compute simultaneous equilibria by solving simultaneously a set of mass balance and mass action equations written for all gas species and for all gas-solid or gas-liquid equilibria. The programs interface with

R. B. Symonds; M. H. Reed

1993-01-01

9

Manipulation et fonctionnalisation de nanotubes. Application aux nanotubes de nitrure de bore.  

E-print Network

Manipulation et fonctionnalisation de nanotubes. Application aux nanotubes de nitrure de bore. Aude´esum´e Ce travail de th`ese se divise en deux grandes parties concernant les nanotubes de ni- trure de bore la fonctionnalisation chi- mique des nanotubes de nitrure de bore. Les nanotubes de nitrure de bore

Paris-Sud XI, Université de

10

Calculation of multicomponent chemical equilibria in gas-solid- liquid systems: calculation methods, thermochemical data, and applications to studies of high-temperature volcanic gases with examples from Mount St. Helens  

USGS Publications Warehouse

This paper documents the numerical formulations, thermochemical data base, and possible applications of computer programs, SOLVGAS and GASWORKS, for calculating multicomponent chemical equilibria in gas-solid-liquid systems. SOLVGAS and GASWORKS compute simultaneous equilibria by solving simultaneously a set of mass balance and mass action equations written for all gas species and for all gas-solid or gas-liquid equilibria. Examples of gas-evaporation-from-magma and precipitation-with-cooling calculations for volcanic gases collected from Mount St. Helens are shown. -from Authors

Symonds, R.B.; Reed, M.H.

1993-01-01

11

GENERAL RESEARCH A Generalized Method for the Solid-Liquid Equilibrium Stage and  

E-print Network

GENERAL RESEARCH A Generalized Method for the Solid-Liquid Equilibrium Stage and Its Application solutions, a generalized method is proposed in this paper for predicting the solid-liquid equilibrium stage by identifying the number of phases and their identities automatically. The proposed method is also used

Zhang, Luzheng

12

Journe de perfectionnement aux applications de l'acupuncture en obsttrique  

E-print Network

Journée de perfectionnement aux applications de l'acupuncture en obstétrique 1er décembre 2011 omnipraticiens acupuncteurs Objectifs : Préciser les bases essentielles des techniques d'acupuncture adaptées à l'obstétrique Préciser les meilleures indications de l'acupuncture en obstétrique Apporter une base rationnelle à l

Brest, Université de

13

Initiation aux applications de l'acupuncture en obsttrique 24 -25 novembre 2011  

E-print Network

Initiation aux applications de l'acupuncture en obstétrique 24 - 25 novembre 2011 Public concerné acupuncteurs Objectifs · Comprendre les principes essentiels de l'acupuncture appliquée à l'obstétrique · Connaître les effets antalgiques de l'acupuncture lors de l'accouchement mais aussi ses effets sur le col

Brest, Université de

14

Systmes de raction-diffusion et HPC: application aux Thierry Dumont1, Violaine Louvet1  

E-print Network

Systèmes de réaction-diffusion et HPC: application aux AVC Thierry Dumont1, Violaine Louvet1. Louvet Systèmes de RD et HPC Séminaire Rouen 1 / 45 #12;1 Contexte et enjeux sociétaux 2 Modélisation de Conclusions et perspectives V. Louvet Systèmes de RD et HPC Séminaire Rouen 2 / 45 #12;Contexte et enjeux

Louvet, Violaine

15

Perturbation theory of solid-liquid interfacial free energies of bcc metals.  

PubMed

A perturbation theory is used to calculate bcc solid-liquid interfacial free energies of metallic systems with embedded-atom model potentials. As a reference system for bcc crystals we used a single-occupancy cell, hard-sphere bcc system. Good agreements between the perturbation theory results and the corresponding results from simulations are found. The strategy to extract hard-sphere bcc solid-liquid interfacial free energies may have broader applications for other crystal lattices. PMID:23030924

Warshavsky, Vadim B; Song, Xueyu

2012-09-01

16

Binary Solid-Liquid Phase Equilibria  

ERIC Educational Resources Information Center

Indicates some of the information that may be obtained from a binary solid-liquid phase equilibria experiment and a method to write a computer program that will plot an ideal phase diagram to which the experimental results may be compared. (Author/CP)

Ellison, Herbert R.

1978-01-01

17

Systems and methods for monitoring a solid-liquid interface  

DOEpatents

Systems and methods are provided for monitoring a solid-liquid interface during a casting process. The systems and methods enable determination of the location of a solid-liquid interface during the casting process.

Stoddard, Nathan G; Lewis, Monte A.; Clark, Roger F

2013-06-11

18

Photoinduced Crystal-to-Liquid Phase Transitions of Azobenzene Derivatives and Their Application in Photolithography Processes through a Solid-Liquid Patterning.  

PubMed

The direct and reversible transformation of matter between the solid and liquid phases by light at constant temperature is of great interest because of its potential applications in various manufacturing settings. We report a simple molecular design strategy for the phase transitions: azobenzenes having para-dialkoxy groups with a methyl group at the meta-position. The photolithography processes were demonstrated using the azobenzene as a photoresist in a single process combining development and etching of a copper substrate. PMID:25216186

Norikane, Yasuo; Uchida, Emi; Tanaka, Satoko; Fujiwara, Kyoko; Koyama, Emiko; Azumi, Reiko; Akiyama, Haruhisa; Kihara, Hideyuki; Yoshida, Masaru

2014-10-01

19

Modlisation plastique bi-linaire de l'usure de matriaux abradables : application aux turbo-machines  

E-print Network

Modélisation plastique bi-linéaire de l'usure de matériaux abradables : application aux turbo'usure des matériaux abradables dans les mo- teurs d'avion est proposée. Ces revêtements sont positionnés sur à une loi de comportement plastique de l'abradable. Afin de maintenir des temps de calcul adaptés à

Paris-Sud XI, Université de

20

Calculation of multicomponent chemical equilibria in gas-solid-liquid systems: Calculation methods, thermochemical data, and applications to studies of high-temperature volcanic gases with examples from Mt. St. Helens  

SciTech Connect

This paper documents the numerical formulations, thermochemical data base, and possible applications of computer programs, SOLVGAS and GASWORKS, for calculating multicomponent chemical equilibria in gas-solid-liquid systems. SOLVGAS and GASWORKS compute simultaneous equilibria by solving simultaneously a set of mass balance and mass action equations written for all gas species and for all gas-solid or gas-liquid equilibria. The programs interface with a thermo-chemical data base, GASTHERM, which contains coefficients for retrieval of the equilibrium constants from 25[degrees] to 1200[degrees]C. The programs and data base model dynamic chemical processes in 30- to 40-component volcanic-gas systems. The authors can model gas evaporation from magma, mixing of magmatic and hydrothermal gases, precipitation of minerals during pressure and temperature decrease, mixing of volcanic gas with air, and reaction of gases with wall rock. Examples are given of the gas-evaporation-from-magma and precipitation-with-cooling calculations for volcanic gases collected from Mt. St. Helens in September 1981. The authors predict: (1) the amounts of trace elements volatilized from shallow magma, deep magma, and wall rock, and (2) the solids that precipitate from the gas upon cooling. The predictions are tested by comparing them with the measured trace-element concentrations in gases and the observed sublimate sequence. This leads to the following conclusions: (1) most of the trace elements in the Mt. St. Helens gases are volatilized from shallow magma as simple chlorides; (2) some elements (for example, Al, Ca) exist dominantly in rock aerosols, not gases, in the gas stream; (3) near-surface cooling of the gases triggers precipitation of oxides, sulfides, halides, tungstates, and native elements; and (4) equilibrium cooling of the gases to 100[degrees]C causes most trace elements, except for Hg, Sb, and Se, to precipitate from the gas. 94 refs., 30 figs., 7 tabs.

Symonds, R.B. (Michigan Technology Univ., Houghton, MI (United States)); Reed, M.H. (Univ. of Oregon, Eugene, OR (United States))

1993-10-01

21

Solid-Liquid Separation of Animal Manure and Wastewater  

E-print Network

Solid-liquid separation is an alternative treatment for animal manure and process-generated wastewater. This publication explains the techniques, equipment, performance and economics of separators....

Mukhtar, Saqib; Sweeten, John M.; Auvermann, Brent W.

1999-10-19

22

An immersed boundary-thermal lattice Boltzmann method for solid-liquid phase change  

NASA Astrophysics Data System (ADS)

In this work, an immersed boundary-thermal lattice Boltzmann method (IB-TLBM) is proposed to simulate solid-liquid phase change problems. To treat the velocity and temperature boundary conditions on the solid-liquid interface, immersed boundary method (IBM) is adopted, in which the solid-liquid interface is represented as a sharp interface rather than a diffusive interface and is tracked explicitly by Lagrangian grid. The surface forces along the immersed boundary, including the momentum force for velocity boundary condition and the energy force for temperature boundary condition, are calculated by the direct-forcing scheme. The moving velocity of solid-liquid interface induced by phase change is calculated by the amount of latent heat absorbed or released in a time step directly, with no need to compute temperature gradients in solid and liquid phases separately. The temperature on the solid-liquid interface is specified as the melting temperature, which means phase change happens at a constant temperature. As the solid-liquid interface evolves with time, the identification of phase of Eulerian points and the rearrangement of Lagrangian points are also considered. With regard to the velocity and temperature fields, passive scalar thermal lattice Boltzmann method (TLBM) with multiple-relaxation-time (MRT) collision schemes is adopted. Numerical examples, including conduction-induced melting in a semi-infinite space and melting in a square cavity, are carried out to verify the present method and good results are obtained. As a further application, melting in a circular cylinder with considering the motion of solid phase is simulated successfully by the present method; numerical results show that the motion of solid phase accelerates the melting process obviously.

Huang, Rongzong; Wu, Huiying

2014-11-01

23

Modlisation plastique bi-linaire de l'usure de matriaux abradables: application aux turbo-machines  

E-print Network

Modélisation plastique bi-linéaire de l'usure de matériaux abradables: application aux turbo.legrand,ronan.ung,christophe.pierre}@mcgill.ca Résumé -- Une prise en compte de l'usure des matériaux abradables dans les turbo-machines est présentée plastique de l'abradable. Il est montré que le comportement de ce matériau est à l'origine de zones d

Paris-Sud XI, Université de

24

Computational Investigations of Solid-Liquid Interfaces  

SciTech Connect

In a variety of materials synthesis and processing contexts, atomistic processes at heterophase interfaces play a critical role governing defect formation, growth morphologies, and microstructure evolution. Accurate knowledge of interfacial structure, free energies, mobilities and segregation coefficients are critical for predictive modeling of microstructure evolution, yet direct experimental measurement of these fundamental interfacial properties remains elusive in many cases. In this project first-principles calculations were combined with molecular-dynamics (MD) and Monte-Carlo (MC) simulations, to investigate the atomic-scale structural and dynamical properties of heterophase interfaces, and the relationship between these properties and the calculated thermodynamic and kinetic parameters that influence the evolution of phase transformation structures at nanometer to micron length scales. The topics investigated in this project were motivated primarily by phenomena associated with solidification processing of metals and alloys, and the main focus of the work was thus on solid-liquid interfaces and high-temperature grain boundaries. Additional efforts involved first-principles calculations of coherent solid-solid heterophase interfaces, where a close collaboration with researchers at the National Center for Electron Microscopy was undertaken to understand the evolution of novel core-shell precipitate microstructures in aluminum alloys.

Mark Asta

2011-08-31

25

Graphene oxide hydrogel at solid/liquid interface.  

PubMed

A strong solid/liquid interfacial interaction is found between porous alumina and graphene oxide (GO) aqueous dispersion, which promotes a fast enrichment of GO on the alumina surface and results in the formation of a GO hydrogel. PMID:21499621

Shao, Jiao-Jing; Wu, Si-Da; Zhang, Shao-Bo; Lv, Wei; Su, Fang-Yuan; Yang, Quan-Hong

2011-05-28

26

An improved technique for modeling initial reservoir hydrocarbon saturation distributions: Applications in Illinois (USA) aux vases oil reservoirs  

USGS Publications Warehouse

An improved technique for modeling the initial reservoir hydrocarbon saturation distributions is presented. In contrast to the Leverett J-function approach, this methodology (hereby termed flow-unit-derived initial oil saturation or FUSOI) determines the distributions of the initial oil saturations from a measure of the mean hydraulic radius, referred to as the flow zone indicator (FZI). FZI is derived from porosity and permeability data. In the FUSOI approach, capillary pressure parameters, S(wir), P(d), and ??, derived from the Brooks and Corey (1966) model [Brooks, R.H., Corey, A.T., 1966. Hydraulic properties of porous media, Hydrology Papers, Colorado State Univ., Ft. Collins, No. 3, March.], are correlated to the FZI. Subsequent applications of these parameters then permit the computation of improved hydrocarbon saturations as functions of FZI and height above the free water level (FWL). This technique has been successfully applied in the Mississippian Aux Vases Sandstone reservoirs of the Illinois Basin (USA). The Aux Vases Zeigler field (Franklin County, IL, USA) was selected for a field-wide validation of this FUSOI approach because of the availability of published studies. With the initial oil saturations determined on a depth-by-depth basis in cored wells, it was possible to geostatistically determine the three-dimensional (3-D) distributions of initial oil saturations in the Zeigler field. The original oil-in-place (OOIP), computed from the detailed initialization of the 3-D reservoir simulation model of the Zeigler field, was found to be within 5.6% of the result from a rigorous material balance method.An improved technique for modeling the initial reservoir hydrocarbon saturation distributions is presented. In contrast to the Leverett J-function approach, this methodology (hereby termed flow-unit-derived initial oil saturation or FUSOI) determines the distributions of the initial oil saturations from a measure of the mean hydraulic radius, referred to as the flow zone indicator (FZI). FZI is derived from porosity and permeability data. In the FUSOI approach, capillary pressure parameters, Swir, Pd, and ??, derived from the Brooks and Corey (1966) model, are correlated to the FZI. Subsequent applications of these parameters then permit the computation of improved hydrocarbon saturations as functions of FZI and height above the free water level (FWL). This technique has been successfully applied in the Mississippian Aux Vases Sandstone reservoirs of the Illinois Basin (USA). The Aux Vases Zeigler field (Franklin County, IL, USA) was selected for a field-wide validation of this FUSOI approach because of the availability of published studies. With the initial oil saturations determined on a depth-by-depth basis in cored wells, it was possible to geostatistically determine the three-dimensional (3-D) distributions of initial oil saturations in the Zeigler field. The original oil-in-place (OOIP), computed from the detailed initialization of the 3-D reservoir simulation model of the Zeigler field, was found to be within 5.6% of the result from a rigorous material balance method.

Udegbunam, E.; Amaefule, J. O.

1998-01-01

27

Solid\\/liquid phase-transfer catalysis. Some models and solvent influence  

Microsoft Academic Search

The applicability of the models developed earlier for the topochemical reactions in the solid\\/liquid phase-transfer catalysis is discussed. Depending on the solvent and the catalyst the reaction may be inhibited by the crust of the solid inorganic product. Solvents like MeCN and THF, and catalysts such as polyethylene glycols loosen this crust, thus preventing the inhibition. The solvent influence using

Felix Sirovski; Christian Reichardt; Marina Gorokhova; Sergei Ruban; Elena Stoikova

1999-01-01

28

In situ transmission electron microscopy of solid-liquid phase transition of silica encapsulated bismuth nanoparticles.  

PubMed

The solid-liquid phase transition of silica encapsulated bismuth nanoparticles was studied by in situ transmission electron microscopy (TEM). The nanoparticles were prepared by a two-step chemical synthesis process involving thermal decomposition of organometallic precursors for nucleating bismuth and a sol-gel process for growing silica. The microstructural and chemical analyses of the nanoparticles were performed using high-resolution TEM, Z-contrast imaging, focused ion beam milling, and X-ray energy dispersive spectroscopy. Solid-liquid-solid phase transitions of the nanoparticles were directly recorded by electron diffractions and TEM images. The silica encapsulation of the nanoparticles prevented agglomeration and allowed particles to preserve their original volume upon melting, which is desirable for applications of phase change nanoparticles with consistently repeatable thermal properties. PMID:21796304

Hu, Jianjun; Hong, Yan; Muratore, Chris; Su, Ming; Voevodin, Andrey A

2011-09-01

29

laboration de couches minces de carbone par ablation laser femtoseconde pour application aux biomatriaux implantables  

NASA Astrophysics Data System (ADS)

Des films de tetrahedral amorphous-Carbon (ta-C) ont t dposs, sous vide pouss, par ablation d'une cible de graphite avec un laser Ti : saphir (dure d'impulsion 170 fs, frquence de rptition 1 kHz, nergie maximale par impulsion 1,5 mJ, longueur d'onde 800 nm) sur substrats standard et sur biomatriaux (acier AISI 316L, polythylne trs haut poids molculaire). Les proprits de ces couches (structure, proprits nanomcaniques et tribologiques) ont t caractrises, en fonction des conditions d'laboration, en examinant l'intrt de l'utilisation d'un laser femtoseconde et leur capacit satisfaire aux exigences spcifiques du domaine biomdical. Les proprits d'adhrence des films ont t considrablement amliores lors du dpt sur des substrats en acier inoxydable pralablement prpars par dcapage ionique in situ sous atmosphre d'argon. La surface hmisphrique d'une tte fmorale, en acier inoxydable, de prothse de hanche de diamtre 22,2 mm a t revtue d'un film de DLC adhrent et homogne en paisseur. La rsistance l'usure de ce revtement sera quantifie l'aide d'un simulateur de marche durant un million de cycles (correspondant une anne d'activit physique d'un tre humain).

Loir, A.-S.; Garrelie, F.; Donnet, C.; Subtil, J.-L.; Belin, M.; Forest, B.; Rogemond, F.; Laporte, P.

2005-06-01

30

Prim-Allaz I., Perrien J & Pras B., (2001) Les apports de la thorie du contrat social l'explication des ruptures de relations de long terme entre organisations : une application aux  

E-print Network

Prim-Allaz I., Perrien J & Pras B., (2001) Les apports de la théorie du contrat social à l RELATIONS DE LONG TERME ENTRE ORGANISATIONS : UNE APPLICATION AUX RELATIONS BANQUES/PME Isabelle PRIM-ALLAZ

Paris-Sud XI, Université de

31

Mathematical modeling of solid-liquid phase-transfer catalysis  

Microsoft Academic Search

Use of phase-transfer catalysis (PTC) has been quite common in organic synthesis in the last two decades. However, there are very few publications on the modeling of PTC systems, particularly solid-liquid systems. The present research suggests a systematic procedure for modeling these reactions, which includes reaction both in the liquid and solid phases. The equations describing these models provide a

Sanjeev D. Naik; L. K. Doraiswamy

1997-01-01

32

Solid-liquid Flow System Simulation and Validation  

Microsoft Academic Search

Computer simulations based on different theories for solid-liquid two-phase flow system were performed for a 126-mile slurry pipeline. A systematic field test program was conducted on the pipeline to verify the simulation results. Acoustic wave speed in slurry with different solids' concentrations was measured. Maximum transient pressure at different locations was recorded. The test data and the simulation results are

George Shou

33

Methods and systems for monitoring a solid-liquid interface  

DOEpatents

Methods and systems are provided for monitoring a solid-liquid interface, including providing a vessel configured to contain an at least partially melted material; detecting radiation reflected from a surface of a liquid portion of the at least partially melted material that is parallel with the liquid surface; measuring a disturbance on the surface; calculating at least one frequency associated with the disturbance; and determining a thickness of the liquid portion based on the at least one frequency, wherein the thickness is calculated based on.times. ##EQU00001## where g is the gravitational constant, w is the horizontal width of the liquid, and f is the at least one frequency.

Stoddard, Nathan G. (Gettysburg, PA); Clark, Roger F. (Frederick, MD); Kary, Tim (Union Bridge, MD)

2010-07-20

34

Etude de films minces de CuInS2, CuIn1-xGaxS2, et Cu2ZnSnS4, labors par voie sol-gel, destins aux applications photovoltaques.  

E-print Network

??Ce travail de recherche porte sur llaboration et la caractrisation de films minces photo-absorbants de CuInS2, CuIn1-xGaxS2, et de Cu2ZnSnS4 destins aux applications photovoltaques. Les (more)

Bourlier, Yoan

2013-01-01

35

Solid-liquid coexistence of polydisperse fluids via simulation  

NASA Astrophysics Data System (ADS)

We describe a simulation method for the accurate study of the equilibrium freezing properties of polydisperse fluids under the experimentally relevant condition of fixed polydispersity. The approach is based on the phase switch Monte Carlo method of Wilding and Bruce [Phys. Rev. Lett. 85, 5138 (2000)]. This we have generalized to deal with particle size polydispersity by incorporating updates which alter the diameter ? of a particle, under the control of a distribution of chemical potential differences ?~(?). Within the resulting isobaric semi-grand-canonical ensemble, we detail how to adapt ?~(?) and the applied pressure such as to study coexistence, while ensuring that the ensemble averaged density distribution ?(?) matches a fixed functional form. Results are presented for the effects of small degrees of polydispersity on the solid-liquid transition of soft spheres.

Wilding, Nigel B.

2009-03-01

36

Methods and systems for monitoring a solid-liquid interface  

DOEpatents

Methods and systems are provided for monitoring a solid-liquid interface, including providing a vessel configured to contain an at least partially melted material; detecting radiation reflected from a surface of a liquid portion of the at least partially melted material; providing sound energy to the surface; measuring a disturbance on the surface; calculating at least one frequency associated with the disturbance; and determining a thickness of the liquid portion based on the at least one frequency, wherein the thickness is calculated based on L=(2m-1)v.sub.s/4f, where f is the frequency where the disturbance has an amplitude maximum, v.sub.s is the speed of sound in the material, and m is a positive integer (1, 2, 3, . . . ).

Stoddard, Nathan G. (Gettysburg, PA); Clark, Roger F. (Frederick, MD)

2011-10-04

37

Solid/liquid interfacial free energies in binary systems  

NASA Technical Reports Server (NTRS)

Description of a semiquantitative technique for predicting the segregation characteristics of smooth interfaces between binary solid and liquid solutions in terms of readily available thermodynamic parameters of the bulk solutions. A lattice-liquid interfacial model and a pair-bonded regular solution model are employed in the treatment with an accommodation for liquid interfacial entropy. The method is used to calculate the interfacial segregation and the free energy of segregation for solid-liquid interfaces between binary solutions for the (111) boundary of fcc crystals. The zone of compositional transition across the interface is shown to be on the order of a few atomic layers in width, being moderately narrower for ideal solutions. The free energy of the segregated interface depends primarily upon the solid composition and the heats of fusion of the component atoms, the composition difference of the solutions, and the difference of the heats of mixing of the solutions.

Nason, D.; Tiller, W. A.

1973-01-01

38

Membrane separations for solid-liquid clarification within lignocellulosic biorefining processes.  

PubMed

Membrane separations can be integrated into a biorefinery to reduce water and energy consumption. Unfortunately, current membrane materials suffer from severe fouling, which limits their applicability. Here, using analytical characterizations along with fouling models, we correlate membrane properties with performance metrics to provide a framework for optimal membrane selection during solid-liquid clarification of a biomass hydrolysate. Five membranes were evaluated: polyether sulfone, mixed cellulose esters, and three surface modified membranes with weak acid, strong acid, and weak base functionalities. Lignin was the primary component responsible for flux decline, due to physical entrapment and chemical adsorption. The best membrane performance (high and sustained flux, low fouling, and high separation factor) was correlated with higher surface roughness, lower hydrophobicity, neutral or positively charged zeta potential, and a larger number of smaller surface pores. These analyses provide valuable information for designing new materials for biorefining processes to reduce fouling and increase stability. PMID:23813787

Leberknight, Jennifer; Menkhaus, Todd J

2013-01-01

39

Dynamic covalent chemistry of bisimines at the solid/liquid interface monitored by scanning tunnelling microscopy  

NASA Astrophysics Data System (ADS)

Dynamic covalent chemistry relies on the formation of reversible covalent bonds under thermodynamic control to generate dynamic combinatorial libraries. It provides access to numerous types of complex functional architectures, and thereby targets several technologically relevant applications, such as in drug discovery, (bio)sensing and dynamic materials. In liquid media it was proved that by taking advantage of the reversible nature of the bond formation it is possible to combine the error-correction capacity of supramolecular chemistry with the robustness of covalent bonding to generate adaptive systems. Here we show that double imine formation between 4-(hexadecyloxy)benzaldehyde and different ?,?-diamines as well as reversible bistransimination reactions can be achieved at the solid/liquid interface, as monitored on the submolecular scale by in situ scanning tunnelling microscopy imaging. Our modular approach enables the structurally controlled reversible incorporation of various molecular components to form sophisticated covalent architectures, which opens up perspectives towards responsive multicomponent two-dimensional materials and devices.

Ciesielski, Artur; El Garah, Mohamed; Haar, Sbastien; Kova??ek, Petr; Lehn, Jean-Marie; Samor, Paolo

2014-11-01

40

Direct Observation of the Atomic Structure in a Solid-Liquid Interface.  

PubMed

An experimental high-resolution image of a solid-liquid interface of solid Si and liquid Al-Si alloy has been compared with theoretical images obtained by computer simulation. It has been concluded that the solid-liquid interface has a transition layer, the structure of which is compatible with the 1 x 1 Si-{111} surface. PMID:10898820

Arai; Tsukimoto; Muto; Saka

2000-07-01

41

A mean field approach for computing solid-liquid surface tension for nanoscale interfaces  

Microsoft Academic Search

The physical properties of a liquid in contact with a solid are largely determined by the solid-liquid surface tension. This is especially true for nanoscale systems with high surface area to volume ratios. While experimental techniques can only measure surface tension indirectly for nanoscale systems, computer simulations offer the possibility of a direct evaluation of solid-liquid surface tension although reliable

Chi-Cheng Chiu; R. J. K. Udayana Ranatunga; David Torres Flores; D. Vladimir Prez; Preston B. Moore; Wataru Shinoda; Steven O. Nielsen

2010-01-01

42

Probing Hydrophilic Interface of Solid/Liquid-Water by Nanoultrasonics  

NASA Astrophysics Data System (ADS)

Despite the numerous devoted studies, water at solid interfaces remains puzzling. An ongoing debate concerns the nature of interfacial water at a hydrophilic surface, whether it is more solid-like, ice-like, or liquid-like. To answer this question, a complete picture of the distribution of the water molecule structure and molecular interactions has to be obtained in a non-invasive way and on an ultrafast time scale. We developed a new experimental technique that extends the classical acoustic technique to the molecular level. Using nanoacoustic waves with a femtosecond pulsewidth and an ngstrm resolution to noninvasively diagnose the hydration structure distribution at ambient solid/water interface, we performed a complete mapping of the viscoelastic properties and of the density in the whole interfacial water region at hydrophilic surfaces. Our results suggest that water in the interfacial region possesses mixed properties and that the different pictures obtained up to now can be unified. Moreover, we discuss the effect of the interfacial water structure on the abnormal thermal transport properties of solid/liquid interfaces.

Mante, Pierre-Adrien; Chen, Chien-Cheng; Wen, Yu-Chieh; Chen, Hui-Yuan; Yang, Szu-Chi; Huang, Yu-Ru; -Ju Chen, I.; Chen, Yun-Wen; Gusev, Vitalyi; Chen, Miin-Jang; Kuo, Jer-Lai; Sheu, Jinn-Kong; Sun, Chi-Kuang

2014-09-01

43

Interaction of Porosity with a Planar Solid/Liquid Interface  

NASA Technical Reports Server (NTRS)

In this paper, an investigation of the interaction between gas porosity and a planar solid/liquid (SL) interface is reported. A two-dimensional numerical model able to accurately track sharp SL interfaces during solidification of pure metals and alloys is proposed. The finite difference method and a rectangular undeformed grid are used for computation. The SL interface is described through the points of intersection with the grid lines. Its motion is determined by the thermal and solute gradients at each particular point. Changes of the interface temperature because of capillarity or solute redistribution as well as any perturbation of the thermal and solute field produced by the presence of non-metallic inclusions can be computed. To validate the model, the dynamics of the interaction between a gas pore and a solidification front in metal alloys was observed using a state of the art X-ray Transmission Microscope. The experiments included observation of the distortion of the SL interface near a pore, real-time measurements of the growth rate and the change in shape of the porosity during interaction with an advancing SL interface in pure Al and Al-0.25 wt% Au alloy. In addition, porosity induced solute segregation patterns surrounding a pore were also quantified.

Catalina, Adrian V.; Stefanescu, Doru M.; Sen, Subhayu; Kaukler, William K.; Curreri, Peter A. (Technical Monitor)

2002-01-01

44

Solid-liquid transition in polydisperse Lennard-Jones systems  

NASA Astrophysics Data System (ADS)

We study melting of a face-centered crystalline solid consisting of polydisperse Lennard-Jones spheres with Gaussian polydispersity in size. The phase diagram reproduces the existence of a nearly temperature invariant terminal polydispersity (?t ? 0.11), with no signature of reentrant melting. The absence of reentrant melting can be attributed to the influence of the attractive part of the potential upon melting. We find that at terminal polydispersity the fractional density change approaches zero, which seems to arise from vanishingly small compressibility of the disordered phase. At constant temperature and volume fraction the system undergoes a sharp transition from crystalline solid to the disordered amorphous or fluid state with increasing polydispersity. This has been quantified by second- and third-order rotational invariant bond orientational order, as well as by the average inherent structure energy. The translational order parameter also indicates a similar sharp structural change at ? ? 0.09 in case of T* = 1.0, ? = 0.58. The free energy calculation further supports the sharp nature of the transition. The third-order rotationally invariant bond order shows that with increasing polydispersity, the local cluster favors a more icosahedral arrangement and the system loses its local crystalline symmetry. Interestingly, the value of structure factor S(k) of the amorphous phase at ? ? 0.10 (just beyond the solid-liquid transition density at T* = 1) becomes 2.75, which is below the value of 2.85 required for freezing given by the empirical Hansen-Verlet rule of crystallization, well known in the theory of freezing.

Sarkar, Sarmistha; Biswas, Rajib; Santra, Mantu; Bagchi, Biman

2013-08-01

45

Wastewater Triad Project: Solid-Liquid Separator FY 2000 Deployment  

SciTech Connect

The Wastewater Triad Project (WTP) consists of three operational units: the cesium removal (CsR) system, the out-of-tank evaporator (OTE) system, and the solid/liquid separation (SLS) system. These systems were designed to reduce the volume and radioactivity of low-level liquid waste (LLLW) stored in the Melton Valley Storage Tanks (MVSTs) and are operated independently or in series in order to accomplish the treatment goals. Each is a modular, skid-mounted system that is self-contained, individually shielded, and designed to be decontaminated and removed once the project has been completed. The CsR and OTE systems are installed inside Building 7877; the SLS system is installed adjacent to the east side of the MVST 7830 vault cover. The CsR, which consists of ion-exchange equipment for removing {sup 137}Cs from LLLW, was demonstrated in 1997. During the Cesium Removal Demonstration, 30,853 gal of radioactive supernate was processed and 1142 Ci of {sup 137}Cs was removed from the supernate and loaded onto 70 gal of a crystalline silicotitanate sorbent manufactured by UOP, Inc. The OTE system is a subatmospheric single-stage evaporator system designed to concentrate LLLW to smaller volumes. It was previously demonstrated in 1996 and was operated in 1998 to process about 80,000 gal of LLLW. The SLS system was designed to filter and remove suspended solids from LLLW in order to minimize further accumulation of sludge in new storage tanks or to prevent fouling of CsR and OTE systems. The SLS was installed and demonstrated in 1999; {approximately}45,000 gal of radioactive supernate was processed during the demonstration.

Walker, J.F.

2001-01-11

46

valuation du POCIS (Polar Organic Chemical Integrative Sampler) : domaine de validit et performances pour 56 micropolluants organiques : application aux hormones, pharmaceutiques, alkyphnols, filtre UV et pesticides.  

E-print Network

??Le POCIS (Polar Organic Chemical Integrative Sampler) est un outil d'chantillonnage intgratif alternatif aux techniques d'chantillonnages classiques (ponctuelle ou automatise) ddi la mesure de (more)

Morin, Nicolas

2013-01-01

47

An experimental measurement of the thermal conductivity and diffusivity of a porous solid-liquid system  

E-print Network

AN EXPERIMENTAL MEASUREMENT QF THE THERMAL CONDUCTIVITY AND DIFFUSIVITY OF A POROUS SOLID LIQUID SYSTEM By James Elliott Dunn A Thesis Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial... fulfillment of the reQuirements for the degree of MASTER OF SCIENCE August 1959 Major Sub)ect: Mechanical Engineering AN EXPERIMENTAL MEASURFJ1ENT OF THE THERMAL CONDUCTIVITY AND DIFFUSIVITY OF A POROUS SOLID LIQUID SYSTEM A Thesis James Elliott Dunn...

Dunn, James Elliott

2012-06-07

48

Experimental (solid + liquid) or (liquid + liquid) phase equilibria of (amine + nitrile) binary mixtures  

Microsoft Academic Search

(Solid+liquid) phase diagrams have been determined for (hexylamine, or octylamine, or 1,3-diaminopropane+acetonitrile) mixtures. Simple eutectic systems have been observed in these mixtures. (Liquid+liquid) phase diagrams have been determined for (octylamine, or decylamine+propanenitrile, or +butanenitrile) mixtures. Mixtures with propanenitrile and butanenitrile show immiscibility in the liquid phase with an upper critical solution temperature, UCST. (Solid+liquid) phase diagrams have been correlated using

Urszula Doma?ska; Ma?gorzata Marciniak

2007-01-01

49

Direct mapping of the solid-liquid adhesion energy with subnanometre resolution  

Microsoft Academic Search

Solid-liquid interfaces play a fundamental role in surface electrochemistry, catalysis, wetting, self-assembly and biomolecular functions. The interfacial energy determines many of the properties of such interfaces, including the arrangement of the liquid molecules at the surface of the solid. Diffraction techniques are often used to investigate the structure of solid-liquid interfaces, but measurements of irregular or inhomogeneous interfaces remain challenging.

Kislon Votchovsky; Jeffrey J. Kuna; Sonia Antoranz Contera; Erio Tosatti; Francesco Stellacci

2010-01-01

50

The solid-liquid surface tension at a helium\\/cesium interface  

Microsoft Academic Search

The existence of a wetting transition for helium adsorbed on cesium provides an experimental opportunity to investigate the solid-liquid surface tension. We have extracted the temperature dependence of the solid-liquid surface tension at the4He\\/Cs interface from our earlier measurements of the wetting temperature of pure4He on thin layers of cesium overlaying gold. More recently we have measured the wetting temperature

J. E. Rutledge; D. Ross; P. Taborek

1995-01-01

51

Comparison of SFI, DSC and NMR methods for determining solid-liquid ratios in fats  

Microsoft Academic Search

Dilatometry (SFI) has gained wide acceptance for the characterization of solid-liquid contents of fats over approximately\\u000a the past 15 years. In more recent times, wide-line nuclear magnetic resonance (NMR) has been used for this purpose. Still\\u000a more recently the differential scanning calorimetry (DSC) technique has been used to determine solid-liquid contents. These\\u000a three techniques were used to determine the properties

R. C. Walker; W. A. Bosin

1971-01-01

52

Solid/liquid lubrication of ceramics at elevated temperatures  

SciTech Connect

This study investigates the effect of solid and liquid lubrication on friction and wear performance of silicon nitride (Si{sub 3}N{sub 4}) and cast iron. The solid lubricant was a thin silver film ({approx}2 {mu}m thick) produced on Si{sub 3}N{sub 4} by ion-beam-assisted deposition. A high-temperature polyol-ester-base synthetic oil served as the liquid lubricant. Friction and wear tests were performed with pin-on-disk and oscillating-slider wear test machines at temperatures up to 300{degrees}C. Without the silver films, the friction coefficients of Si{sub 3}N{sub 4}/Si{sub 3}N{sub 4} test pairs were 0.05 to 0.14, and the average wear rates of Si{sub 3}N{sub 4} pins were {approx}5 x 10{sup -8} mm{sup 3} N{sup -1}. The friction coefficients of Si{sub 3}N{sub 4}/cast iron test pairs ranged from 0.08 to 0.11, depending on test temperature. The average specific wear rates of cast iron pins were {approx}3 x 10{sup -7} mm{sup 3} N{sup -1} m{sup -1}. However, simultaneous use of the solid-lubricant silver and synthetic oil on the sliding surfaces reduced friction coefficients to 0.02 to 0.08. Moreover, the wear of Si{sub 3}N{sub 4} pins and silver-coated Si{sub 3}N{sub 4} disks was so low that it was difficult to assess by a surface profilometer. The wear rates of cast iron pins were {approx}7 x 10{sup -9} mm{sup 3} N{sup -1} m{sup -1} up to 250{degrees}C, but showed a tendency to increase slightly at much higher temperatures. In general, the test results demonstrated that the solid/liquid lubrication of ceramic and/or metallic components is both feasible and effective in controlling friction and wear.

Erdemir, A.; Erck, R.A.; Fenske, G.R. [Argonne National Lab., IL (United States); Hong, H. [Lubrizol Corp., Wickliffe, OH (United States)

1996-04-01

53

Modeling the solid-liquid phase transition in saturated triglycerides  

NASA Astrophysics Data System (ADS)

We investigated theoretically two competing published scenarios for the melting transition of the triglyceride trilaurin (TL): those of (1) Corkery et al. [Langmuir 23, 7241 (2007)], in which the average state of each TL molecule in the liquid phase is a discotic ``Y'' conformer whose three chains are dynamically twisted, with an average angle of ~120 between them, and those of (2) Cebula et al. [J. Am. Oil Chem. Soc. 69, 130 (1992)], in which the liquid-state conformation of the TL molecule in the liquid phase is a nematic h*-conformer whose three chains are in a modified ``chair'' conformation. We developed two competing models for the two scenarios, in which TL molecules are in a nematic compact-chair (or ``h'') conformation, with extended, possibly all-trans, chains at low-temperatures, and in either a Y conformation or an h* conformation in the liquid state at temperatures higher than the phase-transition temperature, T*=319 K. We defined an h-Y model as a realization of the proposal of Corkery et al. [Langmuir 23, 7241 (2007)], and explored its predictions by mapping it onto an Ising model in a temperature-dependent field, performing a mean-field approximation, and calculating the transition enthalpy ?H. We found that the most plausible realization of the h-Y model, as applied to the solid-liquid phase transition in TL, and likely to all saturated triglycerides, gave a value of ?H in reasonable agreement with the experiment. We then defined an alternative h-h* model as a realization of the proposal of Cebula et al. [J. Am. Oil Chem. Soc. 69, 130 (1992)], in which the liquid phase exhibits an average symmetry breaking similar to an h conformation, but with twisted chains, to see whether it could describe the TL phase transition. The h-h* model gave a value of ?H that was too small by a factor of ~3-4. We also predicted the temperature dependence of the 1132 cm-1 Raman band for both models, and performed measurements of the ratios of three TL Raman bands in the temperature range of -20 C<=T<=90 C. The experimental results were in accord with the predictions of the h-Y model and support the proposal of Corkery et al. [Langmuir 23, 7241 (2007)] that the liquid state is made up of molecules that are each, on average, in a Y conformation. Finally, we carried out computer simulations of minimal-model TLs in the liquid phase, and concluded that although the individual TL molecules are, on average, Y conformers, long-range discotic order is unlikely to exist.

Pink, David A.; Hanna, Charles B.; Sandt, Christophe; MacDonald, Adam J.; MacEachern, Ronald; Corkery, Robert; Rousseau, Drick

2010-02-01

54

TOPICAL REVIEW: Sensors and actuators based on surface acoustic waves propagating along solid liquid interfaces  

NASA Astrophysics Data System (ADS)

The propagation of surface acoustic waves (SAWs) along solid-liquid interfaces depends sensitively on the properties of the liquid covering the solid surface and may result in a momentum transfer into the liquid and thus a propulsion effect via acoustic streaming. This review gives an overview of the design of different SAW devices used for the sensing of liquids and the basic mechanisms of the interaction of SAWs with overlaying liquids. In addition, applications of devices based on these phenomena with respect to touch sensing and the measurement of liquid properties such as density, viscosity or the composition of mixed liquids are described, including microfabricated as well as macroscopic devices made from non-piezoelectric materials. With respect to the rapidly growing field of acoustic streaming applications, recent developments in the movement of nanolitre droplets on a single piezoelectric chip, the rather macroscopic approaches to the acoustic pumping of liquids in channels and recent attempts at numerical simulations of acoustic streaming are reported.

Lindner, Gerhard

2008-06-01

55

Characterization of Solid Liquid Suspensions Utilizing Non-Invasive Ultrasonic Measurements  

SciTech Connect

Rapid, on-line characterization of the particle size and concentration of moderate to highly concentrated slurries is required for efficient waste remediation at the DOE complexes. This paper discusses the advancements achieved under the Environmental Management Science Program to accurately characterize high-level waste at the high concentrations expected at the DOE complexes. In addition, the results are applicable to efficient process measurement and control in many chemical and pharmaceutical manufacturing processes. Existing methods for determining the particle size and concentration of non-dilute slurries based on ultrasonic attenuation can become inaccurate due to the complex interactions of ultrasonic waves with the constituents of the slurries and the necessity for very careful transducer alignment. Two measurements that help to overcome these difficulties are the ultrasonic backscattering and diffuse field. The backscattering measurement is attractive because viscous, thermal and inertial effects have small contributions to the backscattering. In addition, the backscattering theories are simpler than attenuation theories and lend themselves to more stable inversion processes. Furthermore, the measurements of backscattering measurement do not require long travel distances and can be made with a single transducer thus eliminating alignment problems. We will present ultrasonic measurements and theoretical comparisons on solid liquid suspensions designed to elucidate the particle size and concentration at high concentration relevant to the high level waste at the DOE complexes.

Panetta, P.D.; Tucker, B.; Ahmed, S.; Pappas, R.A.

2004-03-31

56

Dynamic covalent chemistry of bisimines at the solid/liquid interface monitored by scanning tunnelling microscopy.  

PubMed

Dynamic covalent chemistry relies on the formation of reversible covalent bonds under thermodynamic control to generate dynamic combinatorial libraries. It provides access to numerous types of complex functional architectures, and thereby targets several technologically relevant applications, such as in drug discovery, (bio)sensing and dynamic materials. In liquid media it was proved that by taking advantage of the reversible nature of the bond formation it is possible to combine the error-correction capacity of supramolecular chemistry with the robustness of covalent bonding to generate adaptive systems. Here we show that double imine formation between 4-(hexadecyloxy)benzaldehyde and different ?,?-diamines as well as reversible bistransimination reactions can be achieved at the solid/liquid interface, as monitored on the submolecular scale by in situ scanning tunnelling microscopy imaging. Our modular approach enables the structurally controlled reversible incorporation of various molecular components to form sophisticated covalent architectures, which opens up perspectives towards responsive multicomponent two-dimensional materials and devices. PMID:25343608

Ciesielski, Artur; El Garah, Mohamed; Haar, Sbastien; Kova??ek, Petr; Lehn, Jean-Marie; Samor, Paolo

2014-11-01

57

Indicateurs lis la qualit de l'eau et comportements ; application aux lacs d'Annecy et du Bourget  

Microsoft Academic Search

[eng] The investigation of environment indicators is a descriptive approach but it has the advantage of leading fairly rapidly to practical conclusions. We present the results of an application to two Alpine lakes - Annecy and Le Bourget. It is based on a comparison of hydrobiological parameters and socio-economic data. . The comparative study of the two lakes leads to

Franois Bonnieux; Grard Miclet; Pierre Rainelli

1977-01-01

58

Chers collgues, Nous sommes heureux de vous annoncer un appel aux applications pour le Jonathan Campbell Meakins and Family  

E-print Network

promouvoir l'excellence en éducation médicale. La valeur de la bourse est de $7000. DATE LIMITE D MEMORIAL FELLOWSHIP Un bourse ayant pour but de reconnaître et de faire la promotion de l'excellence en éducation médicale APPLICATIONS BUT Cette bourse a été créée afin de récompenser l'excellence en

Barthelat, Francois

59

Indicateurs lis la qualit de l'eau et comportements. Application aux lacs d'Annecy et du Bourget  

Microsoft Academic Search

[fre] La recherche d'indicateurs d'environnement correspond une approche certes descriptive, mais qui a le mrite de dboucher assez rapidement sur le plan pratique. Nous prsentons les rsultats d'une application au cas de deux lacs alpins : Annecy et le Bourget. Elle repose sur une mise en relation de paramtres de nature hydrobiologique et de donnes socio-conomiques. . L'tude compare

Franois Bonnieux; Grard Miclet; Pierre Rainelli

1978-01-01

60

Phase-field Models for Solidification and Solid/Liquid Interactions  

E-print Network

PHASE-FIELD MODELS FOR SOLIDIFICATION AND SOLID/LIQUID INTERACTIONS A Dissertation by MIN SOO PARK Submitted to the O?ce of Graduate Studies of Texas A&M University in partial ful?llment of the requirements for the degree of DOCTOR OF PHILOSOPHY... December 2009 Major Subject: Mechanical Engineering PHASE-FIELD MODELS FOR SOLIDIFICATION AND SOLID/LIQUID INTERACTIONS A Dissertation by MIN SOO PARK Submitted to the O?ce of Graduate Studies of Texas A&M University in partial ful...

Park, Min Soo

2011-02-22

61

DCLARATION RELATIVE AUX ACCIDENTS JOINDRE AUX PICES ADMINISTRATIVES DEMANDES  

E-print Network

D?CLARATION RELATIVE AUX ACCIDENTS ? JOINDRE AUX PI?CES ADMINISTRATIVES DEMAND?ES POUR LA « responsabilité civile » me couvrant en cas d'accident scolaire (1) - m'engage à m'affilier à compter de la dégage l'université de toute responsabilité en cas d'accident scolaire dont je serais la cause ou la

Sart, Remi

62

Evaluation of target efficiencies for solid-liquid separation steps in biofuels production.  

PubMed

Development of liquid biofuels has entered a new phase of large scale pilot demonstration. A number of plants that are in operation or under construction face the task of addressing the engineering challenges of creating a viable plant design, scaling up and optimizing various unit operations. It is well-known that separation technologies account for 50-70% of both capital and operating cost. Additionally, reduction of environmental impact creates technological challenges that increase project cost without adding to the bottom line. Different technologies vary in terms of selection of unit operations; however, solid-liquid separations are likely to be a major contributor to the overall project cost. Despite the differences in pretreatment approaches, similar challenges arise for solid-liquid separation unit operations. A typical process for ethanol production from biomass includes several solid-liquid separation steps, depending on which particular stream is targeted for downstream processing. The nature of biomass-derived materials makes it either difficult or uneconomical to accomplish complete separation in a single step. Therefore, setting realistic efficiency targets for solid-liquid separations is an important task that influences overall process recovery and economics. Experimental data will be presented showing typical characteristics for pretreated cane bagasse at various stages of processing into cellulosic ethanol. Results of generic material balance calculations will be presented to illustrate the influence of separation target efficiencies on overall process recoveries and characteristics of waste streams. PMID:20607445

Kochergin, Vadim; Miller, Keith

2011-01-01

63

From colloidal dispersions to colloidal pastes through solid/liquid separation processes  

E-print Network

1 From colloidal dispersions to colloidal pastes through solid/liquid separation processes J with a dispersion of solid particles in a liquid, and removes some of the liquid from the particles, producing;3 Introduction Dispersions of fine solid particles in a liquid are commonly used to manufacture coatings

Paris-Sud XI, Université de

64

Reflective Probing of the Electrical Conductivity of Hot Aluminum in the Solid, Liquid, and Plasma Phases  

Microsoft Academic Search

The physics of dense aluminum in transition between metallic and insulating states of the solid, liquid, and plasma phases is probed in thermally equilibrated, inertially confined, laser heated targets. Time resolved laser probes measure the reflectivity of thin aluminum layers embedded inside the target. The electrical conductivity is inferred from the reflectivity with a free-electron Drude conduction model. It is

Andrew N. Mostovych; Yung Chan

1997-01-01

65

Capillarylike fluctuations of a solid-liquid interface in a noncohesive granular system  

NASA Astrophysics Data System (ADS)

One of the most noticeable collective motion of noncohesive granular matter is clustering under certain conditions. In particular, when a quasi-two-dimensional monolayer of monodispersed noncohesive particles is vertically vibrated, a solid-liquid-like transition occurs when the driving amplitude exceeds a critical value. Here the physical mechanism underlying particle clustering relies on the strong interactions mediated by grain collisions, rather than on grain-grain cohesive forces. In average, the solid cluster resembles a drop, with a striking circular shape. We experimentally investigate the coarse-grained solid-liquid interface fluctuations, which are characterized through the static and dynamic correlation functions in the Fourier space. These fluctuations turn out to be well described by the capillary wave theory, which allows us to measure the solid-liquid interface surface tension and mobility once the granular thermal kinetic energy is determined. Despite that the system is strongly out of equilibrium and that the granular temperature is not uniform, there is energy equipartition at the solid-liquid interface, for a relatively large range of angular wave numbers. Furthermore, both surface tension and mobility are consistent with a simple order of magnitude estimation considering the characteristic energy, length, and time scales, which is very similar to what can be done for atomic systems.

Luu, Li-Hua; Castillo, Gustavo; Mujica, Nicols; Soto, Rodrigo

2013-04-01

66

Synthesis of Jasminaldehyde by Solid-Liquid Phase Transfer Catalysis Without Solvent, Under Microwave Irradiation  

Microsoft Academic Search

?-n-amylcinnamaldehyde (jasminaldehyde) was obtained with 82 % yield by solid-liquid phase transfer catalysis without solvent within 3 days at room temperature. By use of domestic microwave irradiation, the same yield was obtained within 1 minute at a power of 600 W.

David Abenham; Chu Pham Ngoc Son; Andr Loupy; Nguyen Ba Hiep

1994-01-01

67

Gemini Surfactants at Solid-Liquid Interfaces: Control of Interfacial Aggregate Geometry  

E-print Network

Gemini Surfactants at Solid-Liquid Interfaces: Control of Interfacial Aggregate Geometry S. Manne of surfactant geometry by using gemini surfactants with varying tail and spacer lengths. On the anionic cleavage of orientations. Gemini or dimeric surfactants13 have been generating increasing interest owing to their superior

Aksay, Ilhan A.

68

All about Solids, Liquids & Gases. Physical Science for Children[TM]. Schlessinger Science Library. [Videotape].  

ERIC Educational Resources Information Center

In All About Solids, Liquids and Gases, young students will be introduced to the three common forms of matter. They'll learn that all things are made up of tiny particles called atoms and that the movement of these particles determines the form that matter takes. In solids, the particles are packed tightly together and move very little. The

2000

69

Rapid advancing of the solidliquid interface in undercooled alloys  

Microsoft Academic Search

Rapid solidification of a binary alloy is considered for conditions of strongly nonequilibrium transformation from the liquid phase to the solid phase. Following the assumption of absence of local equilibrium both at the solidliquid interface and in the solute diffusion field around the interface, an analysis for the response functions (temperature, chemical composition, and solidification velocity) is given. A discussion

P. K. Galenko

2004-01-01

70

Determination of UV filters in packaging by focused ultrasonic solidliquid extraction and liquid chromatography  

Microsoft Academic Search

A focused ultrasonic solidliquid extraction (FUSLE) and high performance liquid chromatography (HPLC) with a diode array detector (DAD) is proposed for the determination of ten fat-soluble UV filters in packaging. FUSLE technique is relatively new and has been used for the extraction of a few analytes; such as polycyclic aromatic hydrocarbons and other organic pollutants. In this work, it has

Cristina Moreta; Mara Teresa Tena

2011-01-01

71

Solid-Liquid Transition and Hydrodynamic Surface Waves in Vibrated Granular Layers  

Microsoft Academic Search

Experiments on thin layers of granular material subjected to vertical vibration have revealed a series of subharmonic bifurcations from flat surface to standing wave patterns. From pressure and surface dilation measurements we show that a solid-liquid-type transition precedes surface wave bifurcation, indicating that these waves are associated with the fluidlike behavior of the layer. Also, we show that depending on

Nicols Mujica; Francisco Melo

1998-01-01

72

Solidliquid extraction of protopine from Fumaria officinalis L.Experimental study and process optimization  

Microsoft Academic Search

Optimization of the protopine batch extraction from Fumaria officinalis was studied by experimental design. Several parameters were first studied in order to measure their influence on batch extraction thus enabling to choose the most accurate model. A response surface method design that allows investigating the simultaneous variations of the three main parameters (percentage of ethanol in solvent, temperature, solidliquid weight

Lovasoa Rakotondramasy-Rabesiaka; Jean-Louis Havet; Catherine Porte; Henri Fauduet

2008-01-01

73

PHYSICAL REVIEW E 86, 031602 (2012) Perturbation theory of solid-liquid interfacial free energies of bcc metals  

E-print Network

-atom model potentials. As a reference system for bcc crystals we used a single-occupancy cell, hard-sphere simulations are found. The strategy to extract hard-sphere bcc solid-liquid interfacial free energies may have to calculate solid-liquid interfacial (SLI) free energies and applied it to model systems with inverse power

Song, Xueyu

74

Binary Solid-Liquid Phase Diagram of Phenol and t-Butanol: An Undergraduate Physical Chemistry Experiment  

ERIC Educational Resources Information Center

The determination of the solid-liquid phase diagram of a binary system is always used as an experiment in the undergraduate physical chemistry laboratory courses. However, most phase diagrams investigated in the lab are simple eutectic ones, despite the fact that complex binary solid-liquid phase diagrams are more common. In this article, the

Xu, Xinhua; Wang, Xiaogang; Wu, Meifen

2014-01-01

75

Electric current effects on solid-solid and solid-liquid metallic reactions  

NASA Astrophysics Data System (ADS)

The interactions at high temperatures between contacting dissimilar metals and the nature of the phases formed from such interactions are of importance in a variety of applications. Solid-solid interactions are important in such considerations as fiber-matrix reactions, diffusion bonding, and electromigration in interconnects in electronic devices, while solid-liquid interactions have practical significance in liquid metal infiltration, soldering and brazing, liquid-metal coating, and liquid metal corrosion. Related to the latter are investigations on solidification and the effect of various parameters on the resulting microstructure. One parameter of interest to the present investigation relates to the effect of electric fields. It was found that the electric field played a dominant role in the dynamics of these reactions and in the concomitant phase formation and microstructure evolution. Due to the difficulty in decoupling the large effect of Joule heating from other current effects, the role of the current is not fully understood. Electromigration is perhaps the best-known electric current effect on conductors. However, the nature of the role of the field in these processes could not be unambiguously determined. In this research, the electric field effect on two simple systems: solid Ni/liquid Al and solid Cu/Ni, was investigated. In solid Ni/liquid Al case, the current effects on the dissolution kinetics of solid Ni into liquid Al, and on the microstructure of solidified samples were investigated. The current had a marked effect on the dissolution rate constant. Correspondingly, the application of the current decreased the activation energy of dissolution significantly. The direction of the DC current was shown to have an effect on dissolution. The influence of a DC current on the microstructural evolution of phases resulting from the dissolution of solid nickel in pure and Ni-saturated liquid aluminum was investigated. In solid Cu/Ni case, the effect of a DC current on the interdiffusivity, D, was investigated. Interdiffusivities were calculated using the Sauer-Freise-den Broeder (SFB) method and the values calculated in the absence of a current were in agreement with previously published results. The influence of the current on D depended on its direction relative to the two interfaces in the tri-layered Cu-Ni-Cu samples.

Zhao, Jinfeng

76

Thermodynamic and rheological properties of solid-liquid systems in coal processing  

SciTech Connect

In this report we present two data sets that have been compiled to assist in the model developments for solid-liquid equilibria and viscosities of coal derived systems. The first one is on vapor pressures of solid aromatics and the second one consists of viscosities of pure model compounds and some mixtures. These databanks are ready for usage in model development and are summarized in Tables 1 and 2. Literature is being searched to compile similar data for high pressure liquid compressibilities, liquid and solid heat capacities and solid-liquid equilibria for model compound systems. Literature search is also containing to investigate available viscosity models. Once this is completed a few models will be selected for evaluation and consideration as candidates for extension to coal liquids.

Kabadi, V.N.; Ilias, S.

1992-01-01

77

Ultrasound-assisted solid liquid extraction (USLE) of olive fruit ( Olea europaea) phenolic compounds  

Microsoft Academic Search

A new method of ultrasound-assisted solid liquid extraction (USLE) of olive fruit phenols is described. Phenolics were extracted using high intensity probe ultrasonication and analysed by HPLC-DAD-FLD-MS\\/MS. Four USLE parameters sonication time (4, 15, 20, 30min), temperature (25, 45C), solvent composition (80%, 100% methanol) and extraction steps (15) were studied and optimised on the basis of nine major olive

T. Jerman; P. Trebe; B. Mozeti? Vodopivec

2010-01-01

78

Solidliquidsolid growth mechanism of single-wall carbon nanotubes  

Microsoft Academic Search

Reasons are presented which suggest that the liquefaction of the catalytic particles is a decisive condition for formation of single wall carbon nanotubes (SWNTs) by physical synthesis techniques. It is argued that the SWNT growth mechanism is a kind of solidliquidsolid graphitization of amorphous carbon or other imperfect carbon forms catalyzed by molten supersaturated carbonmetal nanoparticles. The assumption of low

A Gorbunov; O Jost; W Pompe; A Graff

2002-01-01

79

Controlled growth of oriented amorphous silicon nanowires via a solidliquidsolid (SLS) mechanism  

Microsoft Academic Search

Highly oriented amorphous silicon nanowires (a-SiNWs ) were grown on Si (111). The length and diameter of oriented SiNWs are almost uniform, which are 1?m and 25nm, respectively. Different from the well-known vaporliquidsolid (VLS) for conventional whisker growth, it was found that growth of the a-SiNWs was controlled by a solidliquidsolid mechanism (SLS). This synthesis method is simple and controllable.

D. P Yu; Y. J Xing; Q. L Hang; H. F Yan; J Xu; Z. H Xi; S. Q Feng

2001-01-01

80

Ultrasonic measurement of solid\\/liquid interface position during solidification and melting of metals  

Microsoft Academic Search

The use of pulse-echo ultrasonic flaw detectors to detect the presence and location of cracks, voids, and other discontinuities in metals and non-metal is well known. The solid-liquid interface in a melting or freezing metal can also be considered as a discontinuity, in that there is a measurable difference in both sound velocity and density across the interface. For normal

R. L. Parker

1982-01-01

81

Evaluation of solid-liquid interface profile during continuous casting by a spline based formalism  

Microsoft Academic Search

A numerical framework has been applied which comprises of a cubic spline based collocation method to determine the solid-liquid\\u000a interface profile (solidification front) during continuous casting process. The basis function chosen for the collocation\\u000a algorithm to be employed in this formalism, is a cubic spline interpolation function. An iterative solution methodology has\\u000a been developed to track the interface profile for

S. K. Das

2001-01-01

82

Solidliquid equilibrium in the acetic acidacetophenone and acetic acidformamide systems  

Microsoft Academic Search

Solidliquid equilibrium in the binary systems acetic acidacetophenone and acetic acidformamide was determined from timetemperature cooling and warming curves. The first system shows a sagged curve with a eutectic point at x1?0.6 and T=267.18 K. In the second system a solid compound (2:1) was found and an equilibrium constant of the compound dissociation was calculated.

I. Malijevsk; Z. Sedlkov

2006-01-01

83

Solidliquid extraction of protopine from Fumaria officinalis L.Kinetic modelling of influential parameters  

Microsoft Academic Search

The influences of such parameters as percentage of ethanol in solvent, solidliquid weight ratio and pH of medium on the protopine extraction from Fumaria officinalis particles with mean radius of 0.40.5mm was studied. A mathematical model, describing the importance of each parameter on the extraction of protopine with pseudo-second-order kinetics was proposed and the results were discussed. A numerical solution

L. Rakotondramasy-Rabesiaka; J.-L. Havet; C. Porte; H. Fauduet

2009-01-01

84

InGaAs zone growth single crystal with convex solid liquid interface toward the melt  

NASA Astrophysics Data System (ADS)

We have developed a zone growth method of producing an In xGa 1- xAs single crystal with uniform InAs composition in the direction of the growth. The seed used for this method of zone growth is an InGaAs single crystal grown on a GaAs seed using the vertical gradient freeze (VGF) method. The source for the zone growth method is an InGaAs ternary alloy produced by quenching an InGaAs melt with an InAs composition of 0.3. The convex solid-liquid interface toward the melt is necessary for growing a long InGaAs zone single crystal. We examined ways to control the shape of the solid-liquid interface for the InGaAs zone crystal. We found that: (1) growing an InGaAs crystal in the furnace region, where the temperature gradient in the growth direction changes abruptly, is effective in forming the convex solid-liquid interface toward the melt and (2) lengthening the heat sink attached to a seed increases the efficiency of heat discharge through the crystal and the solid-liquid interface becomes convex. The InGaAs zone crystal having a uniform InAs composition region of 0.3 was a perfect single crystal and was 17 mm long, which is more than twice the length of zone single crystals grown previously. The orientation of the crystal growth was (0 0 1), and the crystal diameter was 15 mm.

Nishijima, Yoshito; Otsubo, Koji; Tezuka, Hiroshige; Nakajima, Kazuo; Ishikawa, Hiroshi

2002-11-01

85

Effect of confinement on the solid-liquid coexistence of Lennard-Jones Fluid  

SciTech Connect

The solid-liquid coexistence of a Lennard-Jones fluid confined in slit pores of variable pore size, H, is studied using molecular dynamics simulations. Three-stage pseudo-supercritical transformation path of Grochola [J. Chem. Phys. 120(5), 2122 (2004)] and multiple histogram reweighting are employed for the confined system, for various pore sizes ranging from 20 to 5 molecular diameters, to compute the solid-liquid coexistence. The Gibbs free energy difference is evaluated using thermodynamic integration method by connecting solid-liquid phases under confinement via one or more intermediate states without any first order phase transition among them. Thermodynamic melting temperature is found to oscillate with wall separation, which is in agreement with the behavior seen for kinetic melting temperature evaluated in an earlier study. However, thermodynamic melting temperature for almost all wall separations is higher than the bulk case, which is contrary to the behavior seen for the kinetic melting temperature. The oscillation founds to decay at around H = 12, and beyond that pore size dependency of the shift in melting point is well represented by the Gibbs-Thompson equation.

Das, Chandan K.; Singh, Jayant K., E-mail: jayantks@iitk.ac.in [Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India)

2013-11-07

86

Abrasion characteristic analyses of solid-liquid two-phase centrifugal pump  

NASA Astrophysics Data System (ADS)

Based on the solid-liquid two-phase mixture transportation test, the renormalization group (RNG) k-e turbulent model was utilized to simulate the solid-liquid two-phase turbulent flow in a centrifugal pump. By comparing the simulated and experimental results, inner flow features were revealed to improve the abrasion characteristic of the solid-liquid two-phase centrifugal pump. The influence of the solid phase on centrifugal pump abrasive performance is small when the particle volume fraction is less than 2.5%. The aggregation degree of the solid particles is enhanced as the particle diameter increases from 0.1 to 1 mm; however, the mixture density on the pressure side is reduced when the particle diameter increases to 1 mm for the impact of inertia. The wear on the hub is most severe for the shear stress on this position; it is also the largest. The wear characteristic is affected greatly by the parameters of the solid phase. The wear chracteristic can be optimized by decreasing the blade outlet angle. In the modified design, the blade angle is different, whereas the other geometric dimensions remain the same. The improved pump is simulated to contrast with the original pump. The results show that the values of mixture density and shear stress both decrease. The wear condition of the blade is improved to a certain extent.

Li, Yi; Zhu, Zuchao; He, Zhaohui; He, Weiqiang

2011-09-01

87

Anisotropic solid-liquid interfacial energy measurement by grain boundary groove method  

NASA Astrophysics Data System (ADS)

Solid-liquid interfacial energy and its anisotropy play an important role in microstructure formation during solidification, which is responsible for the final performance of materials. Grain boundary groove (GBG) method has been developed as a common measurement method for the absolute solid-liquid interfacial energy over the past several decades, but it still can't resolve the anisotropy. In this paper, an improved GBG method for measuring not only the absolute interfacial energy but also the anisotropy was presented and examined in a typical metal analog-pivalic acid (PVA). The equilibrated GBG's in a quasi-2D sample cell under a constant temperature gradient with different orientation angles were observed in PVA. The GBG shapes, the temperature gradient and the crystal orientation were measured and combined to determine the absolute interfacial energy and the anisotropy of PVA. For comparison, the anisotropy of PVA was also measured independently by equilibrium shape method. The results given by the improved GBG method and equilibrium shape method were consistent. It suggests that the improved GBG method can be used to measure the anisotropic solid-liquid interfacial energy accurately.

Wang, Lilin; Lin, Xin; Wang, Meng; Huang, Weidong

2014-11-01

88

Conception, elaboration et mise a l'essai d'un simulateur interactif permettant une approche modelisante: Application aux lois de la genetique mendelienne  

NASA Astrophysics Data System (ADS)

Dans cette recherche-developpement, nous avons concu, developpe et mis a l'essai un simulateur interactif pour favoriser l'apprentissage des lois probabilistes impliqees dans la genetique mendelienne. Cet environnement informatise devra permettre aux etudiants de mener des experiences simulees, utilisant les statistiques et les probebilites comme outils mathematiques pour modeliser le phenomene de la transmission des caracteres hereditaires. L'approche didactique est essentiellement orientee vers l'utilisation des methodes quantitatives impliquees dans l'experimentation des facteurs hereditaires. En incorporant au simulateur le principe de la "Lunette cognitive" de Nonnon (1986), l'etudiant fut place dans une situation ou il a pu synchroniser la perception de la representation iconique (concrete) et symbolique (abstraite) des lois probabilistes de Mendel. A l'aide de cet environnement, nous avons amene l'etudiant a identifier le(s) caractere(s) hereditaire(s) des parents a croiser, a predire les frequences phenotypiques probables de la descendance issue du croisement, a observer les resultats statistiques et leur fluctuation au niveau de l'histogramme des frequences, a comparer ces resultats aux predictions anticipees, a interpreter les donnees et a selectionner en consequence d'autres experiences a realiser. Les etapes de l'approche inductive sont privilegiees du debut a la fin des activites proposees. L'elaboration, du simulateur et des documents d'accompagnement, a ete concue a partir d'une vingtaine de principes directeurs et d'un modele d'action. Ces principes directeurs et le modele d'action decoulent de considerations theoriques psychologiques, didactiques et technologiques. La recherche decrit la structure des differentes parties composant le simulateur. L'architecture de celui-ci est construite autour d'une unite centrale, la "Principale", dont les liens et les ramifications avec les autres unites confere a l'ensemble du simulateur sa souplesse et sa facilite d'utilisation. Le simulateur "Genetique", a l'etat de prototype, et la documentation qui lui est afferente ont ete soumis a deux mises a l'essai: l'une fonctionnelle, l'autre empirique. La mise a l'essai fonctionnelle, menee aupres d'un groupe d'enseignants experts, a permis d'identifier les lacunes du materiel elabore afin de lui apporter les reajustements qui s'imposaient. La mise a l'essai empirique, conduite par un groupe de onze (11) etudiants de niveau secondaire, avait pour but, d'une part, de tester la facilite d'utilisation du simulateur "Genetique" ainsi que les documents d'accompagnement et, d'autre part, de verifier si les participants retiraient des avantages pedagogiques de cet environnement. Trois techniques furent exploitees pour recolter les donnees de la mise a l'essai empirique. L'analyse des resultats a permis de faire un retour critique sur les productions concretes de cette recherche et d'apporter les modifications necessaires tant au simulateur qu'aux documents d'accompagnement. Cette analyse a permis egalement de conclure que notre simulateur interactif favorise une approche inductive permettant aux etudiants de s'approprier les lois probabilistes de Mendel. Enfin, la conclusion degage des pistes de recherches destinees aux etudes ulterieures, plus particulierement celles qui s'interessent a developper des simulateurs, afin d'integrer a ceux-ci des representations concretes et abstraites presentees en temps reel. Les disquettes du simulateur "Genetique" et les documents d'accompagnement sont annexes a la presente recherche.

Lasri, Abdel-Halim

89

Direct numerical simulation of solid-liquid flow of Newtonian and viscoelastic fluids  

NASA Astrophysics Data System (ADS)

The main theme of this work is to enhance the understanding on the behavior of solid particles in flows of Newtonian or viscoelastic fluids by using both two-dimensional and three-dimensional direct numerical simulations (DNS). A large-scale state-of-the-art software package PARTMOVER3D is developed based on an Arbitrary Lagrangian-Eulerian (ALE) technique and an Elastic-Viscous-Stress-Split (EVSS) scheme. Our numerical results are extensively compared with analytical, experimental and numerical ones in the literature. We studied the motion of spheres sedimenting in a cylindrical tube filled with a Newtonian fluid. The hydrodynamic drag and lift on the particle are investigated under various conditions. The effects of the tube wall, in terms of the blockage ratio and the eccentricity ratio, on the particle terminal velocity, migration and rotation are studied. We also investigated the interaction between pair particles released in tandem or side by side at different Reynolds numbers. The migration of particles in a pressure driven flow is the heart of vast number of industrial applications. Using 3-D direct numerical simulations, we systematically investigated the independent parameters controlling the particle migration, which are the blockage ratio, the flow Reynolds number, and the solid-liquid density ratio. During the particle migration, the mechanisms of the fluid inertia, the wall confinement, the local flow shear rate, the particle slip velocity, the particle size, and the particle rotation were extensively examined through the stress distribution on the particle surface under different flow conditions. In the presence of a shear flow, an initially deposited bed of heavy particles will be entrained into the bulk fluid and convected away with the flow. We investigated the mechanism of this particle resuspension by using 2-D direct numerical simulations. Various effects on the lift force on the particle was analyzed by examining the distribution of the stress on the particle surface. We also studied the orientation of an elliptic particle during its resuspension, analyzed the interaction between a pair of particles, and presented the results of the resuspension of a layer of particles. There are striking differences of particle motions in viscoelastic and Newtonian fluids. We explained the mechanism of the anomalous particle behavior due to the elasticity of the viscoelastic fluid. The effects of the Deborah number, the Reynolds number, the retardation-relaxation time ratio, the blockage ratio, and the eccentricity rate on the behavior of the particles were also systemically investigated.

Zhu, Mingyu

90

Flow Strength of Shocked Aluminum in the Solid-Liquid Mixed Phase Region  

NASA Astrophysics Data System (ADS)

Shock waves have been used to determine material properties under high shock stresses and very-high loading rates. The determination of mechanical properties such as compressive strength under shock compression has proven to be difficult and estimates of strength have been limited to approximately 100 GPa or less in aluminum. The term ``strength'' has been used in different ways. For a Von-Mises solid, the yield strength is equal to twice the shear strength of the material and represents the maximum shear stress that can be supported before yield. Many of these concepts have been applied to materials that undergo high strain-rate dynamic deformation, as in uni-axial strain shock experiments. In shock experiments, it has been observed that the shear stress in the shocked state is not equal to the shear strength, as evidenced by elastic recompressions in reshock experiments. This has led to an assumption that there is a yield surface with maximum (loading)and minimum (unloading), shear strength yet the actual shear stress lies somewhere between these values. This work provides the first simultaneous measurements of unloading velocity and flow strength for transition of solid aluminum to the liquid phase. The investigation describes the flow strength observed in 1100 (pure), 6061-T6, and 2024 aluminum in the solid-liquid mixed phase region. Reloading and unloading techniques were utilized to provide independent data on the two unknowns (?c and ?o), so that the actual critical shear strength and the shear stress at the shock state could be estimated. Three different observations indicate a change in material response for stresses of 100 to 160 GPa; 1) release wave speed (reloading where applicable) measurements, 2) yield strength measurements, and 3) estimates of Poisson's ratio, all of which provide information on the melt process including internal consistency and/or non-equilibrium and rate-dependent melt behavior. The study investigates the strength properties in the solid region and as the material transverses the solid-mixed- liquid regime. Differences observed appear to be the product of alloying and/or microstructural composition of the aluminum.

Reinhart, William

2011-06-01

91

Practical aspects of Kelvin-probe force microscopy at solid/liquid interfaces in various liquid media  

NASA Astrophysics Data System (ADS)

The distributions of surface charges or surface potentials on biological molecules and electrodes are directly related to various biological functions and ionic adsorptions, respectively. Electrostatic force microscopy and Kelvin-probe force microscopy (KFM) are useful scanning probe techniques that can map local surface charges and potentials. Here, we report the measurement and analysis of the electrostatic and capacitive forces on the cantilever tip induced by application of an alternating voltage in order to discuss the feasibility of measuring the surface charge or potential distribution at solid/liquid interfaces in various liquid media. The results presented here suggest that a nanometer-scale surface charge or potential measurement by the conventional voltage modulation techniques is only possible under ambient conditions and in a non-polar medium and is difficult in an aqueous solution. Practically, the electrostatic force versus dc voltage curve in water does not include the minimum, which is used for the surface potential compensation. This is because the cantilever oscillation induced by the electrostatic force acting on the tip apex is overwhelmed by the parasitic oscillation induced by the electrostatic force acting on the entire cantilever as well as the surface stress effect. We both experimentally and theoretically discuss the factors which cause difficulties in application of the voltage modulation techniques in the aqueous solutions and present some criteria for local surface charge and potential measurements by circumventing these problems.

Umeda, Ken-ichi; Kobayashi, Kei; Oyabu, Noriaki; Hirata, Yoshiki; Matsushige, Kazumi; Yamada, Hirofumi

2014-10-01

92

Numerical simulation and analysis of solid-liquid two-phase flow in centrifugal pump  

NASA Astrophysics Data System (ADS)

The flow with solid-liquid two-phase media inside centrifugal pumps is very complicated and the relevant method for the hydraulic design is still immature so far. There exist two main problems in the operation of the two-phase flow pumps, i.e., low overall efficiency and severe abrasion. In this study, the three-dimensional, steady, incompressible, and turbulent solid-liquid two-phase flows in a low-specific-speed centrifugal pump are numerically simulated and analyzed by using a computational fluid dynamics (CFD) code based on the mixture model of the two-phase flow and the RNG k- ? two-equation turbulence model, in which the influences of rotation and curvature are fully taken into account. The coupling between impeller and volute is implemented by means of the frozen rotor method. The simulation results predicted indicate that the solid phase properties in two-phase flow, especially the concentration, the particle diameter and the density, have strong effects on the hydraulic performance of the pump. Both the pump head and the efficiency are reduced with increasing particle diameter or concentration. However, the effect of particle density on the performance is relatively minor. An obvious jet-wake flow structure is presented near the volute tongue and becomes more remarkable with increasing solid phase concentration. The suction side of the blade is subject to much more severe abrasion than the pressure side. The obtained results preliminarily reveal the characteristics of solid-liquid two-phase flow in the centrifugal pump, and are helpful for improvement and empirical correction in the hydraulic design of centrifugal pumps.

Zhang, Yuliang; Li, Yi; Cui, Baoling; Zhu, Zuchao; Dou, Huashu

2013-01-01

93

Determination of the mean solid-liquid interface energy of pivalic acid  

NASA Technical Reports Server (NTRS)

A high-confidence solid-liquid interfacial energy is determined for an anisotropic material. A coaxial composite having a cylindrical specimen chamber geometry provides a thermal gradient with an axial heating wire. The surface energy is derived from measurements of grain boundary groove shapes. Applying this method to pivalic acid, a surface energy of 2.84 erg/sq cm was determined with a total systematic and random error less than 10 percent. The value of interfacial energy corresponds to 24 percent of the latent heat of fusion per molecule.

Singh, N. B.; Gliksman, M. E.

1989-01-01

94

Solid/liquid interface shape and Marangoni convection on a germanium float zone  

NASA Astrophysics Data System (ADS)

The usefulness of low gravity for growing homogeneous, exceptionally pure crystals has been demonstrated several times in the past. Crystals of both organic and inorganic substances have been successfully grown in space, obtaining a purity and homogeneity unachievable in 1- g conditions. In this paper, a numerical modelling was performed to simulate the free surface behaviour and the solid/liquid interface shape for a germanium float zone. In order to verify the accuracy of the programme, a comparison between numerical and experimental results for a sodium nitrate liquid column was made.

Saghir, M. Z.

95

Nanocrystallization of CaCO 3 at solid/liquid interfaces in magnetic field: A quantum approach  

NASA Astrophysics Data System (ADS)

With the application of 1.2 T external magnetic field, 90% of CaCO 3 soluble molecules in water flow precipitate on stainless steel 316 solid/liquid interface in the form of aragonite/vaterite. The magnetic field increases locally the thermodynamic potentials at interface, favoring the formation of aragonite than calcite, despite the fact that the field-free ground electronic state of aragonite is situated higher than of calcite. A quantum mechanical model predicts that magnetic fluctuations inside the liquid can be amplified by exchanging energy with an external magnetic field through the angular momentum of the water molecular rotors and with the macroscopic angular momentum of the turbulent flow. The theoretical model predicts that the gain is higher when the magnetic field is in resonance with the rotational frequencies of the molecular rotors or/and the low frequencies of the turbulent flow and that aragonite concentration is increasing at 0.4 T in agreement with the experimental results. Contrary to calcite, aragonite binds weakly on flow surfaces; and hence the process has significant industrial, environmental and biological impact.

Cefalas, A. C.; Kobe, S.; Draic, G.; Sarantopoulou, E.; Kollia, Z.; Straiar, J.; Meden, A.

2008-08-01

96

On-farm treatment of swine manure based on solid-liquid separation and biological nitrification-denitrification of the liquid fraction.  

PubMed

In some regions, intensive pig farming has led to soil and water pollution due to the over-application of manure as an organic fertilizer, thereby necessitating alternative treatment technologies to help manage the large amounts of manure generated. The present study seeks to determine the effectiveness of an on-farm swine manure treatment plant consisting of a solid-liquid separation phase using screw pressing followed by a coagulation-flocculation process, and nitrification-denitrification of the liquid fraction. Each treatment unit was evaluated for its contribution towards reducing the raw manure concentration of solids, organic matter, nutrients (nitrogen and phosphorous), metals, and pathogens. The overall system presented high removal efficiencies of up to 71% of TS (total solids) and 97% of TCOD (total chemical oxygen demand). Approximately 97% TKN (total Kjeldahl nitrogen) and 89% TP (total phosphorous) removal was achieved. Metals (copper and zinc) diminished in the liquid fraction to non-detectable concentrations (<1.0mgL(-1)). As regards microbial removal, total concentration reductions of 3.6 log10 for Escherichia coli and 1.8 log10 for Salmonella were achieved. Finally, the system was evaluated from a financial standpoint. Results indicate that screw pressing and coagulation-flocculation for solid-liquid separation and nitrification-denitrification of the liquid fraction is a technological alternative for reducing the environmental impact of intensive pig farming in a given area. PMID:24291581

Riao, B; Garca-Gonzlez, M C

2014-01-01

97

Nanoelectrical analysis of single molecules and atomic-scale materials at the solid/liquid interface  

NASA Astrophysics Data System (ADS)

Evaluating the built-in functionality of nanomaterials under practical conditions is central for their proposed integration as active components in next-generation electronics. Low-dimensional materials from single atoms to molecules have been consistently resolved and manipulated under ultrahigh vacuum at low temperatures. At room temperature, atomic-scale imaging has also been performed by probing materials at the solid/liquid interface. We exploit this electrical interface to develop a robust electronic decoupling platform that provides precise information on molecular energy levels recorded using in situ scanning tunnelling microscopy/spectroscopy with high spatial and energy resolution in a high-density liquid environment. Our experimental findings, supported by ab initio electronic structure calculations and atomic-scale molecular dynamics simulations, reveal direct mapping of single-molecule structure and resonance states at the solid/liquid interface. We further extend this approach to resolve the electronic structure of graphene monolayers at atomic length scales under standard room-temperature operating conditions.

Nirmalraj, Peter; Thompson, Damien; Molina-Ontoria, Agustn; Sousa, Marilyne; Martn, Nazario; Gotsmann, Bernd; Riel, Heike

2014-10-01

98

Atomistic simulation of CdTe solid-liquid coexistence equilibria  

SciTech Connect

Atomistic simulations of CdTe using a Stillinger-Weber (S-W) interatomic potential were undertaken to model the solid-liquid phase equilibria of this important compound semiconductor. Although this potential has been used by others to study liquid CdTe and vapor-liquid interface, it is based on fitting parameters optimized only for the zincblende solid. It has not been fully explored as a potential for solid-liquid phase equilibria until this work. This research reports an accurate determination of the melting temperature, TM=1305K near P=0, the heat of fusion at melting and as a function of temperature up to 1700K, and on the relative phase densities with a particular emphasis on the melting line. The S-W potential for CdTe predicts a liquid with a density slightly less than that of the solid and, hence, the pressure-temperature melting line has a positive slope. The pair correlation structure of the liquid is determined and favorably compared to neutron scattering data. The liquid-solid interface is discussed using density profiles and a short-range order parameter for models having principal orientations along <100>, <110>, and <111> crystallographic directions.

Henager, Charles H.; Morris, James R.

2009-12-07

99

Anharmonicity, solvation forces, and resolution in atomic force microscopy at the solid-liquid interface  

NASA Astrophysics Data System (ADS)

Solid-liquid interfaces are central to nanoscale science and technology and control processes as diverse as self-assembly, heterogeneous catalysis, wetting, electrochemistry, or protein function. Experimentally, measuring the structure and dynamics of solid-liquid interfaces with molecular resolution remains a challenge. This task can, in principle, be achieved with atomic force microscopy (AFM), which functions locally, and with nanometer precision. When operated dynamically and at small amplitudes, AFM can provide molecular-level images of the liquid solvation layers at the interfaces. At larger amplitudes, results in the field of multifrequency AFM have shown that anharmonicities in the tip motion can provide quantitative information about the solid's mechanical properties. The two approaches probe opposite aspects of the interface and are generally seen as distinct. Here it is shown that, for amplitudes Ad, the tip trajectory becomes rapidly anharmonic due to the tip tapping the solid, and the resolution decreases. A nonlinear transition between the two regimes occurs for Ad and can be quantified with the second harmonic of the tip oscillation. These results, confirmed by computer simulations, remain valid in most experimental conditions. Significantly, they provide an objective criterion to enhance resolution and to decide whether the results are dominated by the properties of the solid or of the liquid.

Votchovsky, Kislon

2013-08-01

100

Investigating the solid-liquid phase transition of water nanofilms using the generalized replica exchange method.  

PubMed

The generalized Replica Exchange Method (gREM) was applied to study a solid-liquid phase transition in a nanoconfined bilayer water system using the monatomic water (mW) model. Exploiting optimally designed non-Boltzmann sampling weights with replica exchanges, gREM enables an effective sampling of configurations that are metastable or unstable in the canonical ensemble via successive unimodal energy distributions across phase transition regions, often characterized by S-loop or backbending in the statistical temperature. Extensive gREM simulations combined with Statistical Temperature Weighted Histogram Analysis Method (ST-WHAM) for nanoconfined mW water at various densities provide a comprehensive characterization of diverse thermodynamic and structural properties intrinsic to phase transitions. Graph representation of minimized structures of bilayer water systems determined by the basin-hopping global optimization revealed heterogeneous ice structures composed of pentagons, hexagons, and heptagons, consistent with an increasingly ordered solid phase with decreasing density. Apparent crossover from a first-order solid-liquid transition to a continuous one in nanoconfined mW water with increasing density of the system was observed in terms of a diminishing S-loop in the statistical temperature, smooth variation of internal energies and heat capacities, and a characteristic variation of lateral radial distribution functions, and transverse density profiles across transition regions. PMID:25399190

Lu, Qing; Kim, Jaegil; Farrell, James D; Wales, David J; Straub, John E

2014-11-14

101

Investigating the solid-liquid phase transition of water nanofilms using the generalized replica exchange method  

NASA Astrophysics Data System (ADS)

The generalized Replica Exchange Method (gREM) was applied to study a solid-liquid phase transition in a nanoconfined bilayer water system using the monatomic water (mW) model. Exploiting optimally designed non-Boltzmann sampling weights with replica exchanges, gREM enables an effective sampling of configurations that are metastable or unstable in the canonical ensemble via successive unimodal energy distributions across phase transition regions, often characterized by S-loop or backbending in the statistical temperature. Extensive gREM simulations combined with Statistical Temperature Weighted Histogram Analysis Method (ST-WHAM) for nanoconfined mW water at various densities provide a comprehensive characterization of diverse thermodynamic and structural properties intrinsic to phase transitions. Graph representation of minimized structures of bilayer water systems determined by the basin-hopping global optimization revealed heterogeneous ice structures composed of pentagons, hexagons, and heptagons, consistent with an increasingly ordered solid phase with decreasing density. Apparent crossover from a first-order solid-liquid transition to a continuous one in nanoconfined mW water with increasing density of the system was observed in terms of a diminishing S-loop in the statistical temperature, smooth variation of internal energies and heat capacities, and a characteristic variation of lateral radial distribution functions, and transverse density profiles across transition regions.

Lu, Qing; Kim, Jaegil; Farrell, James D.; Wales, David J.; Straub, John E.

2014-11-01

102

Monitoring the solid-liquid interface in tanks using profiling sonar and 3D visualization techniques  

NASA Astrophysics Data System (ADS)

Visualization of the interface between settled solids and the optically opaque liquid above is necessary to facilitate efficient retrieval of the high-level radioactive waste (HLW) from underground storage tanks. A profiling sonar was used to generate 2-D slices across the settled solids at the bottom of the tank. By incrementally rotating the sonar about its centerline, slices of the solid-liquid interface can be imaged and a 3-D image of the settled solids interface generated. To demonstrate the efficacy of the sonar in real-time solid-liquid interface monitoring systems inside HLW tanks, two sets of experiments were performed. First, various solid objects and kaolin clay (10 ?m dia) were successfully imaged while agitating with 30% solids (by weight) entrained in the liquid. Second, a solid with a density similar to that of the immersed fluid density was successfully imaged. Two dimensional (2-D) sonar images and the accuracy and limitations of the in-tank imaging will be presented for these two experiments. In addition, a brief review of how to utilize a 2-D sonar image to generate a 3-D surface of the settled layer within a tank will be discussed.

Sood, Nitin; Zhang, Jinsong; Roelant, David; Srivastava, Rajiv

2005-03-01

103

Nanoelectrical analysis of single molecules and atomic-scale materials at the solid/liquid interface.  

PubMed

Evaluating the built-in functionality of nanomaterials under practical conditions is central for their proposed integration as active components in next-generation electronics. Low-dimensional materials from single atoms to molecules have been consistently resolved and manipulated under ultrahigh vacuum at low temperatures. At room temperature, atomic-scale imaging has also been performed by probing materials at the solid/liquid interface. We exploit this electrical interface to develop a robust electronic decoupling platform that provides precise information on molecular energy levels recorded using in situ scanning tunnelling microscopy/spectroscopy with high spatial and energy resolution in a high-density liquid environment. Our experimental findings, supported by ab initio electronic structure calculations and atomic-scale molecular dynamics simulations, reveal direct mapping of single-molecule structure and resonance states at the solid/liquid interface. We further extend this approach to resolve the electronic structure of graphene monolayers at atomic length scales under standard room-temperature operating conditions. PMID:25129620

Nirmalraj, Peter; Thompson, Damien; Molina-Ontoria, Agustn; Sousa, Marilyne; Martn, Nazario; Gotsmann, Bernd; Riel, Heike

2014-10-01

104

III -INTRODUCTION AUX TESTS STATISTIQUES  

E-print Network

III - INTRODUCTION AUX TESTS STATISTIQUES J-P. Croisille Universit´e de Lorraine UEL - Ann´ee 2012/2013 Jean-Pierre CROISILLE - Laboratoire LMAM UEL: L'influence des math´ematiques sur la soci´et´e #12 LMAM UEL: L'influence des math´ematiques sur la soci´et´e #12;CHOIX DE L'HYPOTHESE NEUTRE ET DE L

Croisille, Jean-Pierre

105

New Composite Membranes for High Throughput Solid-Liquid Separations at the Savannah River Site  

SciTech Connect

New Composite Membranes for High Throughput Solid-Liquid Separations at the Savannah River Site R. Bhave (Oak Ridge National Laboratory. Oak Ridge, TN) and M. R. Poirier* (Savannah River National Laboratory, Aiken SC) Solid-liquid separation is the limiting step for many waste treatment processes at the Savannah River Site. SRNL researchers have identified the rotary microfilter as a technology to improve the rate of solid-liquid separation processes. SRNL is currently developing the rotary microfilter for radioactive service and plans to deploy the technology as part of the small column ion exchange process. The rotary microfilter can utilize any filter media that is available as a flat sheet. The current baseline membrane is a 0.5 micron (nominal) porous metal filter (Pall PMM050). Previous testing with tubular filters showed that filters composed of a ceramic membrane on top of a stainless steel support produce higher flux than filters composed only of porous metal. The authors are working to develop flat sheet filter media composed of a ceramic membrane and/or ceramic-metal composite on top of a porous stainless steel support that can be used with the rotary microfilter to substantially increase filter flux resulting in a more compact, energy efficient and cost-effective high level radioactive waste treatment system. Composite membranes with precisely controlled pore size distribution were fabricated on porous metal supports. High quality uniform porous metal (316SS) supports were fabricated to achieve high water permeability. Separative layers of several different materials such as ultrafine metal particles and ceramic oxides were used to fabricate composite membranes. The fabrication process involved several high temperature heat treatments followed by characterization of gas and liquid permeability measurements and membrane integrity analysis. The fabricated composite membrane samples were evaluated in a static test cell manufactured by SpinTek. The composite membranes were evaluated on several feed slurries: 1 wt. % strontium carbonate in deionized water, 1 wt. % monosodium titanate in simulated salt solution, and 1 wt. % simulated sludge in simulated salt solution and deionized water. Flux as a function of feed flow rate and transmembrane pressure was measured for each of the above described feed slurries. The authors will discuss the new membrane development efforts, waste slurry filtration performance evaluations and scale-up considerations.

Bhave, Ramesh R [ORNL

2012-01-01

106

Modeling of ultrasound transmission through a solid-liquid interface comprising a network of gas pockets  

NASA Astrophysics Data System (ADS)

Ultrasonic inspection of sodium-cooled fast reactor requires a good acoustic coupling between the transducer and the liquid sodium. Ultrasonic transmission through a solid surface in contact with liquid sodium can be complex due to the presence of microscopic gas pockets entrapped by the surface roughness. Experiments are run using substrates with controlled roughness consisting of a network of holes and a modeling approach is then developed. In this model, a gas pocket stiffness at a partially solid-liquid interface is defined. This stiffness is then used to calculate the transmission coefficient of ultrasound at the entire interface. The gas pocket stiffness has a static, as well as an inertial component, which depends on the ultrasonic frequency and the radiative mass.

Paumel, K.; Moysan, J.; Chatain, D.; Corneloup, G.; Baqu, F.

2011-08-01

107

Crystal growth from a supersaturated melt: relaxation of the solid-liquid dynamic stiffness  

E-print Network

We discuss the growth process of a crystalline phase out of a metastable over-compressed liquid that is brought into contact with a crystalline substrate. The process is modeled by means of molecular dynamics. The particles interact via the Lennard-Jones potential and their motion is locally thermalized by Langevin dynamics. We characterize the relaxation process of the solid-liquid interface, showing that the growth speed is maximal for liquid densities above the solid coexistence density, and that the structural properties of the interface rapidly converge to equilibrium-like properties. In particular, we show that the off-equilibrium dynamic stiffness can be extracted using capillary wave theory arguments, even if the growth front moves fast compared to the typical diffusion time of the compressed liquid, and that the dynamic stiffness converges to the equilibrium stiffness in times much shorter than the diffusion time.

Francesco Turci; Tanja Schilling

2014-05-20

108

Surface Specularity as an Indicator of Shock-induced Solid-liquid Phase Transitions in Tin  

SciTech Connect

When highly polished metal surfaces melt upon release after shock loading, they exhibit features that suggest significant surface changes accompany the phase transition. The reflection of light from such surfaces changes from specular (pre-shock) to diffuse upon melting. Typical of this phenomenon is the loss of signal light in velocity interferometer system for any reflector (VISAR) measurements, which usually occurs at pressures high enough to melt the free surface. Unlike many other potential material phase-sensitive diagnostics (e.g., reflectometry, conductivity), that show relatively small (1%-10%) changes, the specularity of reflection provides a more sensitive and definitive (>10x) indication of the solid-liquid phase transition. Data will be presented that support the hypothesis that specularity changes indicate melt in a way that can be measured easily and unambiguously.

G. D. Stevens, S. S. Lutz, B. R. Marshall, W.D. Turley, et al.

2007-12-01

109

In situ determination of the nanoscale chemistry and behavior of solid-liquid systems.  

PubMed

Many fundamental questions in crystal-growth behavior remain unanswered because of the difficulties encountered in simultaneously observing phases and determining elemental concentrations and redistributions while crystals nucleate and grow at the nanoscale. We show that these obstacles can be overcome by performing energy-dispersive x-ray spectroscopy on partially molten Al-Si-Cu-Mg alloy particles during in situ heating in a transmission electron microscope. Using this technique, we were able to (i) determine that the aluminum and silicon concentrations change in a complementary and symmetric manner about the solid-liquid interface as a function of temperature; (ii) directly measure the solid- and liquid-phase compositions at equilibrium and in highly undercooled conditions for quantitative comparison with thermodynamic calculations of the liquidus and solidus phase boundaries; and (iii) provide direct evidence for homogeneous nucleation of the aluminum-rich solid. PMID:18048685

Eswaramoorthy, Santhana K; Howe, James M; Muralidharan, Govindarajan

2007-11-30

110

Dependence of solid-liquid interface free energy on liquid structure  

NASA Astrophysics Data System (ADS)

The Turnbull relation is widely believed to enable prediction of solid-liquid interface (SLI) free energies from measurements of the latent heat and the solid density. Ewing proposed an additional contribution to the SLI free energy to account for variations in liquid structure near the interface. In the present study, molecular dynamics (MD) simulations were performed to investigate whether SLI free energy depends on liquid structure. Analysis of the MD simulation data for 11 fcc metals demonstrated that the Turnbull relation is only a rough approximation for highly ordered liquids, whereas much better agreement is observed with Ewing's theory. A modification to Ewing's relation is proposed in this study that was found to provide excellent agreement with MD simulation data.

Wilson, S. R.; Mendelev, M. I.

2014-09-01

111

Anaerobic digestion of acidified slurry fractions derived from different solid-liquid separation methods.  

PubMed

Batch assays investigating the ultimate methane yields (B(0)) of acidified slurry fractions produced with different solid-liquid slurry separation techniques were done. The result showed that the anaerobic digestion (AD) process was inhibited when raw and liquid fractions of sow, pig and dairy cow acidified slurry are digested, but AD treating solid fractions (SF) acidified slurry showed no sulphide inhibition. The B(0) of SF acidified sow slurry increased significantly with increasing screen size in the screw press. No significant effect of acidification processes on B(0) of SF dairy cow slurry (DCS) was observed. The ultimate methane yields of SF acidified DCS and SF non acidified DCS were 27813 and 2891LkgVS(-1), while in term of fresh weigh substrate were 592.8 and 590.3Lkgsubstrate(-1), respectively. PMID:23313767

Sutaryo, Sutaryo; Ward, Alastair James; Mller, Henrik Bjarne

2013-02-01

112

SOLIEX: A Novel Solid-Liquid Method of Radionuclides Extraction from Radioactive Waste Solutions - 13486  

SciTech Connect

This paper describes recent developments in new solid-liquid extraction method, called SOLIEX, to remove cesium from alkaline solutions. SOLIEX relies on the use of a reversible complexing system comprising a carbon felt bearing molecular traps (calixarenes). This complexing system exhibits a high selectivity for Cs, and is thus expected to be helpful for the treatment of highly diluted cesium wastes even with a high concentration of competing alkali metal cations. As additional advantage, this complexing system can be adapted by molecular engineering to capture other radionuclides, such as Sr, Eu, Am. Finally, this complexing system can be easily and efficiently regenerated by using a cost effective stripping procedure, which limits further generation of waste to meet 'zero liquid' discharge requirements for nuclear facilities. (authors)

Shilova, E.; Viel, P. [CEA Saclay, DSM/IRAMIS/SPCSI, 91191Gif sur Yvette (France)] [CEA Saclay, DSM/IRAMIS/SPCSI, 91191Gif sur Yvette (France); Fournel, B.; Barre, Y. [CEA Marcoule, DTCD, BP17171, 30207 Bagnols sur Ceze (France)] [CEA Marcoule, DTCD, BP17171, 30207 Bagnols sur Ceze (France); Huc, V. [ICMMO - UMR CNRS 8182 - Bat. 420 Universite Paris-Sud (France)] [ICMMO - UMR CNRS 8182 - Bat. 420 Universite Paris-Sud (France)

2013-07-01

113

Bilayer molecular assembly at a solid/liquid interface as triggered by a mild electric field.  

PubMed

The construction of a spatially defined assembly of molecular building blocks, especially in the vertical direction, presents a great challenge for surface molecular engineering. Herein, we demonstrate that an electric field applied between an STM tip and a substrate triggered the formation of a bilayer structure at the solid-liquid interface. In contrast to the typical high electric-field strength (10(9) ?V?m(-1) ) used to induce structural transitions in supramolecular assemblies, a mild electric field (10(5) ?V?m(-1) ) triggered the formation of a bilayer structure of a polar molecule on top of a nanoporous network of trimesic acid on graphite. The bilayer structure was transformed into a monolayer kagome structure by changing the polarity of the electric field. This tailored formation and large-scale phase transformation of a molecular assembly in the perpendicular dimension by a mild electric field opens perspectives for the manipulation of surface molecular nanoarchitectures. PMID:25376428

Zheng, Qing-Na; Liu, Xuan-He; Liu, Xing-Rui; Chen, Ting; Yan, Hui-Juan; Zhong, Yu-Wu; Wang, Dong; Wan, Li-Jun

2014-12-01

114

A spectroscopic ruler to measure chain conformations at the solid-liquid interface  

NASA Astrophysics Data System (ADS)

There do not appear to exist prior measurements of the conformations of polymers adsorbed to dilute coverage at the solid-liquid interface, in spite of abundant theoretical predictions. Here direct information is obtained by monitoring the fluorescence energy transfer between dyes located at the two ends of adsorbed polymer chains. The basic idea is that the farther the chain ends are spaced, the less efficient, and slower, is energy migration between these dyes. It occurs on the nanosecond time scale and is measured here by time-correlated single photon counting. From corresponding experiments performed with the same polymer chains labeled at one sole end, the contribution of rate of energy transfer to rotational anisotropy is decoupled from intrinsic rotational motion of the dyes themselves.

Kumar, Subhalakshmi; Wong, Janet; Bae, Sung Chul; Granick, Steve

2009-03-01

115

Determining the Nanoscale Chemistry and Behavior of Solid-Liquid Systems  

SciTech Connect

Many fundamental questions in crystal-growth behavior remain unanswered because of the difficulties encountered in simultaneously observing phases and determining elemental concentrations and redistributions while crystals nucleate and grow at the nanoscale. We show that these obstacles can be overcome by performing energy-dispersive x-ray spectroscopy on partially molten Al-Si-Cu-Mg alloy particles during in situ heating in a transmission electron microscope. Using this technique, we were able to (i) determine that the aluminum and silicon concentrations change in a complementary and symmetric manner about the solid-liquid interface as a function of temperature; (ii) directly measure the solid- and liquid-phase compositions at equilibrium and in highly undercooled conditions for quantitative comparison with thermodynamic calculations of the liquidus and solidus phase boundaries; and (iii) provide direct evidence for homogeneous nucleation of the aluminum-rich solid.

Eswaramoorthy, Santhana [University of Virginia; Howe, Prof. James M [University of Virginia; Muralidharan, Govindarajan [ORNL

2007-01-01

116

Nanoscale aggregate structures of trisiloxane surfactants at the solid-liquid interface.  

PubMed

The self-associating structures at the solid-liquid interface of three nonionic trisiloxane surfactants ((CH3)3SiO)2Si(CH3)(CH2)3(OCH2CH2)n OH (n = 6, 8, and 12), or BEn, are studied as a function of substrate properties by atomic force microscopy (AFM) imaging and force measurement. These trisiloxane surfactants are known as superwetters, which promote rapid spreading of dilute aqueous solutions on low-energy surfaces. This study also attempts to relate the BEn surface aggregate structures at the solid-liquid interface to their superwetting behavior. Four substrates are used in the study: muscovite mica, highly oriented pyrolytic graphite, and oxidized silicon wafer with and without a full monolayer of self-assembled n-octadecyltrichlorosilane (OTS). The concentration of BEn is fixed at 2 times the critical aggregation concentration (CAC). The BEn surfactants are only weakly attracted to hydrophilic surfaces, more on oxidized silicon than on mica. All three form ordinary planar monolayers on HOPG and OTS-covered oxidized silicon. The significance of surfactant adsorption on the AFM tip is investigated by comparing the force curves obtained by tips with and without thiol modification. The surface aggregate structures of the BEn surfactants correlate with their bulk structures and do not exhibit anomalous adsorption behavior. The adsorption behavior of the BEn superwetters is similar to that of the CmEn surfactants. Thus, our results confirm previous work showing that superwetting shares its main features with other classes of surfactants. PMID:15835139

Dong, Jinping; Mao, Guangzhao; Hill, Randal M

2004-03-30

117

Maladies relies aux loisirs aquatiques  

PubMed Central

Rsum Objectif Passer en revue les facteurs de risque, la prise en charge et la prvention des maladies relies aux loisirs aquatiques en pratique familiale. Sources des donnes Des articles originaux et de synthse entre janvier 1998 et fvrier 2012 ont t identifis laide de PubMed et des expressions de recherche en anglais water-related illness, recreational water illness et swimmer illness. Message principal Il y a un risque de 3 % 8 % de maladies gastrointestinales (MGI) aprs la baignade. Les groupes risque lev de MGI sont les enfants de moins de 5 ans, surtout sils nont pas t vaccins contre le rotavirus, les personnes ges et les patients immunodficients. Les enfants sont plus grand risque parce quils avalent plus deau quand ils nagent, restent dans leau plus longtemps et jouent dans leau peu profonde et le sable qui sont plus contamins. Les adeptes des sports dans lesquels le contact avec leau est abondant comme le triathlon et le surf cerf-volant sont aussi risque lev et mme ceux qui sadonnent des activits impliquant un contact partiel avec leau comme la navigation de plaisance et la pche ont un risque de 40 % 50 % fois plus grand de MGI par rapport ceux qui ne pratiquent pas de sports aquatiques. Il y a lieu de faire une culture des selles quand on souponne une maladie relie aux loisirs aquatiques et lchelle clinique de la dshydratation est utile pour lvaluation des besoins de traitement chez les enfants affects. Conclusion Les maladies relies aux loisirs aquatiques est la principale cause de MGI durant la saison des baignades. La reconnaissance que la baignade est une source importante de maladies peut aider prvenir les cas rcurrents et secondaires. On recommande fortement le vaccin contre le rotavirus chez les enfants qui se baignent souvent.

Sanborn, Margaret; Takaro, Tim

2013-01-01

118

Novelties of microwave irradiated solidliquid phase transfer catalysis (MISL-PTC) in synthesis of 2?-benzyloxyacetophenone  

Microsoft Academic Search

2?-Benzyloxyacetophenone is an important pharmaceutical intermediate for the manufacture of drugs used as diuretics, antihypertensive, platelet, antiaggregant, lipoxygenase, analgesics and prostaglandin, and for treatment of metabolic disorders. Microwave irradiation has been widely used for the rapid synthesis of a variety of compounds. In the current work, for the first time, novelties of low power microwave irradiated solidliquid phase transfer catalysis,

Ganapati D. Yadav; Priyal M. Bisht

2004-01-01

119

Investigations of Water Structure at the Solid/Liquid Interface in the Presence of Supported Lipid Bilayers by  

E-print Network

slower than that of positively charged and neutral SLBs. Introduction Solid supported lipid bilayersInvestigations of Water Structure at the Solid/Liquid Interface in the Presence of Supported Lipid-dimensionally confined waterlayer,whichhasbeenestimatedtobeapproximately 0.5-1.5 nm in thickness, acts as a lubricant

120

Solidliquid extraction of protopine from Fumaria officinalis L.Analysis determination, kinetic reaction and model building  

Microsoft Academic Search

Solidliquid extraction was performed in a batch extractor, from aerial parts of Fumaria officinalis, in order to obtain an extract containing protopine. This study relates the influences of the temperature and nature of the solvent on the kinetics and rates of extraction. A method to quantify the protopine contents by Reverse Phase-High Pressure Liquid Chromatography was initially perfected. Then, a

Lovasoa Rakotondramasy-Rabesiaka; Jean-Louis Havet; Catherine Porte; Henri Fauduet

2007-01-01

121

Solid-liquid equilibrium for mixtures containing cresols, piperazine, and dibutyl ether  

SciTech Connect

The solid-liquid phase diagrams have been determined for six binary and one ternary system composed of m-cresol, p-cresol, piperazine, and dibutyl ether. The results indicate the existence of 1-2 complexes in the p-cresol + m-cresol, piperazine + m-cresol, and piperazine + p-cresol systems. The observed melting points were correlated with composition by an empirical equation. Dissociation extractive crystallization is one of the potential methods for separating a compound from close boiling point mixtures such as p-cresol + 2,6-xylenol (1) and m-cresol + p-cresol systems. Gaikar et al. reported that using piperazine as a neutralizing agent and dibutyl ether as a solvent enables the recovery of 91% of p-cresol from a m-cresol + p-cresol mixture. This attractive method is of interest for further investigations. This attractive method is of interest for further investigations. To obtain better insight into this separation process, the authors measured the melting points of the mixtures composed of m-cresol, p-cresol, piperazine, and dibutyl ether by the solid-disappearance method over a temperature range from 246 and 382 K and atmospheric pressure.

Mingjer Lee; Peichi Chi (National Taiwan Inst. of Tech., Taipei (Taiwan, Province of China))

1993-04-01

122

DETERMINATION OF SOLID-LIQUID EQUILIBRIA DATA FOR MIXTURES OF HEAVY HYDROCARBONS IN A LIGHT SOLVENT  

SciTech Connect

A methodology was developed using an FT-IR spectroscopic technique to obtain solid-liquid equilibria (SLE) data for mixtures of heavy hydrocarbons in significantly lighter hydrocarbon diluents. SLE was examined in multiple Model Oils that were assembled to simulate waxes. The various Model oils were comprised of C-30 to C-44 hydrocarbons in decane. The FT-IR technique was used to identify the wax precipitation temperature (WPT). The DSC technique was also used in the identification of the onset of the two-phase equilibrium in this work. An additional Model oil made up of C-20 to C-30 hydrocarbons in decane was studied using the DSC experiment. The weight percent solid below the WPT was calculated using the FT-IR experimental results. The WPT and the weight percent solid below the WPT were predicted using an activity coefficient based thermodynamic model. The FT-IR spectroscopy method is found to successfully provide SLE data and also has several advantages over other laboratory-based methods.

F.V. Hanson; J.V. Fletcher; Karthik R.

2003-06-01

123

Gold catalyzed nickel disilicide formation: a new solid-liquid-solid phase growth mechanism.  

PubMed

The vapor-liquid-solid (VLS) mechanism is the predominate growth mechanism for semiconductor nanowires (NWs). We report here a new solid-liquid-solid (SLS) growth mechanism of a silicide phase in Si NWs using in situ transmission electron microcopy (TEM). The new SLS mechanism is analogous to the VLS one in relying on a liquid-mediating growth seed, but it is fundamentally different in terms of nucleation and mass transport. In SLS growth of Ni disilicide, the Ni atoms are supplied from remote Ni particles by interstitial diffusion through a Si NW to the pre-existing Au-Si liquid alloy drop at the tip of the NW. Upon supersaturation of both Ni and Si in Au, an octahedral nucleus of Ni disilicide (NiSi2) forms at the center of the Au liquid alloy, which thereafter sweeps through the Si NW and transforms Si into NiSi2. The dissolution of Si by the Au alloy liquid mediating layer proceeds with contact angle oscillation at the triple point where Si, oxide of Si, and the Au alloy meet, whereas NiSi2 is grown from the liquid mediating layer in an atomic stepwise manner. By using in situ quenching experiments, we are able to measure the solubility of Ni and Si in the Au-Ni-Si ternary alloy. The Au-catalyzed mechanism can lower the formation temperature of NiSi2 by 100 C compared with an all solid state reaction. PMID:24274698

Tang, Wei; Picraux, S Tom; Huang, Jian Yu; Liu, Xiaohua; Tu, K N; Dayeh, Shadi A

2013-01-01

124

Enhanced degradation of phenanthrene in a solid-liquid two-phase partitioning bioreactor via sonication.  

PubMed

The current article examined the feasibility of inducing improved delivery and degradation of phenanthrene in a solid-liquid partitioning bioreactor system at bench scale by means of ultrasonic energy input. Initial degradation rates of phenanthrene by a microbial consortium, delivered from Desmopan, were improved 2.7-fold in the presence of sonication relative to unsonicated controls. Results demonstrated that an operating window involving on/off sonication cycling improved substrate delivery and rational selection of ultrasound cycling profiles could lead to even further enhancements. Additionally, all results were obtained in a conventional bioreactor with commercial ultrasonic equipment and a commercially available polymer. Subsequent DGGE analysis demonstrated that the sonication cycles selected maintained consortium compositions, relative to control cases, and suggest that exposure would not reduce degradative capabilities under the periods of irradiation examined. Finally, consortium members were identified as belonging to the Pandoraea, Sphingobium, and Pseudoxanthomonas genera. Comparison of genetic sequences in the Ribosomal Database Project revealed that some of the bacterial members, identified at the strain level, had been previously observed in PAH degradations, while others have been reported only in the degradation of other aromatics, such as pesticides. PMID:19998286

Isaza, Pedro A; Daugulis, Andrew J

2010-04-01

125

Kinetics of Dissolution and Isothermal Solidification for Gold-Enriched Solid-Liquid Interdiffusion (SLID) Bonding  

NASA Astrophysics Data System (ADS)

This paper presents the development and characterization of a fluxless die-attach soldering process based on gold-enriched solid-liquid interdiffusion (SLID). Eutectic Au-Sn and pure Au were deposited by jet vapor deposition (JVD) onto two substrates, assembled in a sandwiched structure, and processed in a vacuum furnace using different temperatures and times. Microstructural characterization, based on scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS) analysis, revealed the formation of sound joints governed by the interdiffusion of the main constituents. Kinetic studies for the dissolution and the isothermal solidification stages were conducted. Differential scanning calorimetry (DSC) revealed a solder joint that is thermally stable up to 498C, thus demonstrating the effectiveness of using the SLID process for the production of joints which require a lower processing temperature compared with their remelting point. Based on these findings, the recommended final bonding parameters are processing temperature and time of 340C (310C < T P < 340C) and 5 min, respectively.

Rodriguez, Rogie I.; Ibitayo, Dimeji; Quintero, Pedro O.

2013-08-01

126

Determination of UV filters in packaging by focused ultrasonic solid-liquid extraction and liquid chromatography.  

PubMed

A focused ultrasonic solid-liquid extraction (FUSLE) and high performance liquid chromatography (HPLC) with a diode array detector (DAD) is proposed for the determination of ten fat-soluble UV filters in packaging. FUSLE technique is relatively new and has been used for the extraction of a few analytes; such as polycyclic aromatic hydrocarbons and other organic pollutants. In this work, it has been demonstrated that FUSLE is a useful, fast and simple extraction methodology for UV filters because the complete extraction was carried out with just 6ml of tetrahydrofuran and in only one cycle of 30s. The developed method has been validated and applied to the analysis of polyethylene-based multilayer packaging samples. The FUSLE-based method allows the sensitive detection of most of the UV-filters in polyethylene, with limits of detection between 0.4 and 8.5ngmg(-1) (except for BDM). Intra and inter-day relative standard deviation values were below 5 and 14%, respectively, except for MBP. In addition, the proposed method was more efficient than tetrahydrofuran extraction under reflux for 2.5h for all the analytes except for EMT and BDM. Therefore, the developed method can be used to establish the absorption capability of different types of packaging and this information will be very useful in packaging selection. PMID:21185027

Moreta, Cristina; Tena, Mara Teresa

2011-05-27

127

Inhomogeneous molecular distribution in self-spreading lipid bilayers at the solid/liquid interface.  

PubMed

Self-spreading lipid bilayers at the solid/liquid interface can be used as a molecular transport medium in targeting nano-devices such as drug delivery and micro-total analytical systems. To gain physico-chemical insight in the self-spreading lipid bilayer, we have characterized the distribution of dye-labeled lipids in the upper and lower monolayers of a self-spreading lipid bilayer on a hydrophobic substrate by fluorescence quenching experiments using KI as a quencher. TR-DHPE, a molecule with a dye moiety at the head group, was found to be distributed primarily in the upper layer and accumulated especially at the spreading edge because of high steric repulsion. This resulted in an asymmetric distribution of TR-DHPE in the self-spreading bilayer in both the vertical and lateral directions. By contrast, NBD-PC, bearing a dye moiety at the alkyl chain, was distributed almost symmetrically both vertically and laterally. The observed difference is attributed to the difference in interactions between these molecules in the lower layer and the substrate surface. We have also found that the self-spreading velocity was decreased by the addition of KI. Since the spreading dynamics are determined by the interaction energy between the bilayer and solid substrate, a part of the observed velocity decrease could be explained by the change in the lipid density resulting from the adsorption of the I- anion on the lipid head group, thereby reducing the van der Waals interaction energy. PMID:21711242

Nabika, Hideki; Sumida, Tomoki; Murakoshi, Kei

2011-12-01

128

Atomic layering and misfit-induced densification at the Si(111)/In solid-liquid interface  

NASA Astrophysics Data System (ADS)

We report on the solid-liquid interface structure between Si(111) substrates and indium at temperatures just above its melting point. At similar metal-semiconductor interfaces, liquid density enhancements have been observed by Reichert et al. [1]. Our surface x-ray diffraction study reveals that there is pronounced layering of the liquid near the interface. The data allow for identifying both layering length scales: the interlayer distance of 2.2 ? and the decay length of approximately 15 ?. Furthermore do we find the very first layer of indium adjacent to the Si(111) to be partially laterally ordered at the substrate's hollow sites. We introduce a hard sphere packing model that can explain the experimentally observed layering distance and anisotropic order. This packing also reveals that due to the misfit between the size of the indium atoms and the periodicity of the substrate, the indium atoms can pack together closer than in the bulk liquid. These results show that the lateral interaction between the substrate and the liquid directly influences the layering distance and that the resulting packing can account for part of the previously observed enhanced densities.

Vonk, Vedran; Cremers, Melissa; de Jong, Aryan; Pintea, Stelian; Vlieg, Elias

2014-03-01

129

Complex Inclusions at Solid-Liquid Interface of Low-Oxygen Special Steel  

NASA Astrophysics Data System (ADS)

The movements of CaO-MgO-Al2O3-SiO2 inclusions at solid-liquid (S-L) interface during the solidification of low-oxygen special steel were observed in real time by the confocal laser scanning microscope, in an attempt to explore the possible formation mechanism of the D-type and DS-type inclusions. It was found that S-L interfaces showed strong interaction with the inclusions, especially when the inclusions were captured. Collision and agglomeration between inclusion in liquid steel and inclusion captured by the S-L interface were reproducibly observed, followed by an obvious size growth. During this process, inclusions in liquid steel acted as the guest particles, while the S-L interface capture inclusions acted as the host particles. There were also inclusions first moved toward and then later away from the S-L interfaces. To explain the behaviors of inclusion pairs, the forces acted on inclusions were estimated and discussed. Based on the obtained result, it can be cautiously pointed out that collision and agglomeration of inclusions at S-L interface during the casting of steel are probably important reasons for the frequent existence of D-type and DS-type inclusions during the production of low-oxygen special steel despite the high cleanliness. Therefore, minimization of inclusion size is significant except for the reduction of the inclusion numbers.

Jiang, Min; Wang, Xin-Hua; Pak, Jong-Jin; Yuan, Peng

2014-10-01

130

Numerical formulation for the prediction of solid/liquid change of a binary alloy  

NASA Technical Reports Server (NTRS)

A computational model is presented for the prediction of solid/liquid phase change energy transport including the influence of free convection fluid flow in the liquid phase region. The computational model considers the velocity components of all non-liquid phase change material control volumes to be zero but fully solves the coupled mass-momentum problem within the liquid region. The thermal energy model includes the entire domain and uses an enthalpy like model and a recently developed method for handling the phase change interface nonlinearity. Convergence studies are performed and comparisons made with experimental data for two different problem specifications. The convergence studies indicate that grid independence was achieved and the comparison with experimental data indicates excellent quantitative prediction of the melt fraction evolution. Qualitative data is also provided in the form of velocity vector diagrams and isotherm plots for selected times in the evolution of both problems. The computational costs incurred are quite low by comparison with previous efforts on solving these problems.

Schneider, G. E.; Tiwari, S. N.

1990-01-01

131

Solid-Liquid Interdiffusion Bonding of Silicon Carbide to Steel for High Temperature MEMS Sensor Packaging and Bonding  

NASA Astrophysics Data System (ADS)

Complex engineering systems ranging from automobile engines to geothermal wells require specialized sensors to monitor conditions such as pressure, acceleration and temperature in order to improve efficiency and monitor component lifetime in what may be high temperature, corrosive, harsh environments. Microelectromechanical systems (MEMS) have demonstrated their ability to precisely and accurately take measurements under such conditions. The systems being monitored are typically made from metals, such as steel, while the MEMS sensors used for monitoring are commonly fabricated from silicon, silicon carbide and aluminum nitride, and so there is a sizable thermal expansion mismatch between the two. For these engineering applications the direct bonding of MEMS sensors to the components being monitored is often required. This introduces several challenges, namely the development of a bond that is capable of surviving high temperature harsh environments while mitigating the thermally induced strains produced during bonding. This project investigates the development of a robust packaging and bonding process, using the gold-tin metal system and the solid-liquid interdiffusion (SLID) bonding process, to join silicon carbide substrates directly to type-316 stainless steel. The SLID process enables bonding at lower temperatures while producing a bond capable of surviving higher temperatures. Finite element analysis was performed to model the thermally induced strains generated in the bond and to understand the optimal way to design the bond. The cross-sectional composition of the bonds has been analyzed and the bond strength has been investigated using die shear testing. The effects of high temperature aging on the bond's strength and the metallurgy of the bond were studied. Additionally, loading of the bond was performed at temperatures over 415 C, more than 100 C, above the temperature used for bonding, with full survival of the bond, thus demonstrating the benefit of SLID bonding for high temperature applications. Lastly, this dissertation provides recommendations for improving the strength and durability of the bond at temperatures of 400 C and provides the framework for future work in the area of high temperature harsh environment MEMS packaging that would take directly bonded MEMS to temperatures of 600 C and beyond.

Chan, Matthew Wei-Jen

132

Commissariat l'nergie atomique et aux nergies alternatives Chocs Avances 2010, Avances scientifiques et techniques de la Direction des applications militaires.  

E-print Network

I Cible d'ignition et instabilités laser-plasma S. LAFITTE, P. LoISEAu Amplification paramétrique d, Avancées scientifiques et techniques de la Direction des applications militaires. Image de couverture. LASSALLE, J. GrunEnwALD, F. zuCChInI INTERACTIoN lASER-MATIèRE Phénomènes d'accrétion magnétique en

Skupin, Stefan

133

Preparation, structure and crystallinity of chitosan nano-fibers by a solidliquid phase separation technique  

Microsoft Academic Search

Chitosan acetate nano-fibers were fabricated via a solidliquid phase separation technique. The chitosan acetate structure was influenced by phase separation temperature, chitosan concentration and acetic acid concentration. Uniform nano-fibrous chitosan acetate of 50500nm in diameter was engineered at 0.05% (w\\/v) chitosan and 0.025% (v\\/v) acetic acid in liquid nitrogen, as opposed to film-shape and micro-fibrous structure at ?18C and ?80C

Jianhao Zhao; Wanqing Han; Haodong Chen; Mei Tu; Rong Zeng; Yunfeng Shi; Zhengang Cha; Changren Zhou

2011-01-01

134

Solidliquid equilibrium in the acetic acidcyclohexane and acetic acidtrichloroacetic acid systems  

Microsoft Academic Search

Solidliquid equilibrium in the binary systems acetic acidcyclohexane and acetic acidtrichloroacetic acid was determined from timetemperature cooling and heating curves. The first system shows an eutectic point at x1?0.08 and T=271.9K. In the second system, a solid compound (1:1) was found and an equilibrium constant of the compound dissociation was calculated.

I Malijevsk

2003-01-01

135

Phase-transfer catalysis: kinetics and mechanism of dichlorocyclopropane formation in liquid\\/liquid and solid\\/liquid systems  

Microsoft Academic Search

The kinetics and mechanism of dichlorocarbene addition to C?C bond under liquid\\/liquid (l\\/l) and solid\\/liquid (s\\/l) phase-transfer catalysis conditions are discussed. In the s\\/l system reaction kinetics is strongly influenced by the formation of a crust of solid NaCl on the NaOH surface. In the l\\/l system the reaction is significantly slower and occurs in a liquid border film. The

Felix Sirovski; Marina Gorokhova; Sergei Ruban

2003-01-01

136

ZnO nanoneedle/H2O solid-liquid heterojunction-based self-powered ultraviolet detector  

PubMed Central

ZnO nanoneedle arrays were grown vertically on a fluorine-doped tin oxide-coated glass by hydrothermal method at a relatively low temperature. A self-powered photoelectrochemical cell-type UV detector was fabricated using the ZnO nanoneedles as the active photoanode and H2O as the electrolyte. This solid-liquid heterojunction offers an enlarged ZnO/water contact area and a direct pathway for electron transport simultaneously. By connecting this UV photodetector to an ammeter, the intensity of UV light can be quantified using the output short-circuit photocurrent without a power source. High photosensitivity, excellent spectral selectivity, and fast photoresponse at zero bias are observed in this UV detector. The self-powered behavior can be well explained by the formation of a space charge layer near the interface of the solid-liquid heterojunction, which results in a built-in potential and makes the solid-liquid heterojunction work in photovoltaic mode. PMID:24103153

2013-01-01

137

ZnO nanoneedle/H2O solid-liquid heterojunction-based self-powered ultraviolet detector  

NASA Astrophysics Data System (ADS)

ZnO nanoneedle arrays were grown vertically on a fluorine-doped tin oxide-coated glass by hydrothermal method at a relatively low temperature. A self-powered photoelectrochemical cell-type UV detector was fabricated using the ZnO nanoneedles as the active photoanode and H2O as the electrolyte. This solid-liquid heterojunction offers an enlarged ZnO/water contact area and a direct pathway for electron transport simultaneously. By connecting this UV photodetector to an ammeter, the intensity of UV light can be quantified using the output short-circuit photocurrent without a power source. High photosensitivity, excellent spectral selectivity, and fast photoresponse at zero bias are observed in this UV detector. The self-powered behavior can be well explained by the formation of a space charge layer near the interface of the solid-liquid heterojunction, which results in a built-in potential and makes the solid-liquid heterojunction work in photovoltaic mode.

Li, Qinghao; Wei, Lin; Xie, Yanru; Zhang, Kai; Liu, Lei; Zhu, Dapeng; Jiao, Jun; Chen, Yanxue; Yan, Shishen; Liu, Guolei; Mei, Liangmo

2013-10-01

138

i:\\staff\\auxs\\auxs_uho\\common\\forms_current\\correspondence\\pet agreement.doc University Housing  

E-print Network

i:\\staff\\auxs\\auxs_uho\\common\\forms_current\\correspondence\\pet agreement.doc University Housing Cat in their rooms based upon the following conditions: A. The student must register his/her pet prior to the animal Signature Date There is a non-refundable $50 pet fee for cats. Upon registration, staff will place a marker

Bertini, Robert L.

139

KNOWLEDGE MANAGEMENT ET INTELLIGENCE ECONOMIQUE : DEUX NOTIONS AUX PASSES PROCHES ET AUX FUTURS COMPLEMENTAIRES  

E-print Network

KNOWLEDGE MANAGEMENT ET INTELLIGENCE ECONOMIQUE : DEUX NOTIONS AUX PASSES PROCHES ET AUX FUTURS-Nancy Résumé : Les notions de Knowledge Management (KM) et d'Intelligence Economique (IE) partagent un grand futurs probables du KM et de l'IE à l'horizon 2012. Summary : Knowledge Management (KM) and Economic

Paris-Sud XI, Université de

140

Aide aux utilisateurs Nouveaux marchs Voyages et hbergement 2012 AIDE AUX UTILISATEURS  

E-print Network

1 Aide aux utilisateurs Nouveaux marchés Voyages et hébergement 2012 14/11/2012 AIDE AUX UTILISATEURS DANS LE CADRE DES NOVEAUX MARCHES « VOYAGES ET HEBERGEMENT » 2012 Ce document vous permettra de. Comment valider un voyage ? ........................................................................ 9 9

van Tiggelen, Bart

141

Digestion of frozen/thawed food waste in the hybrid anaerobic solid-liquid system  

SciTech Connect

The hybrid anaerobic solid-liquid (HASL) system, which is a modified two-phase anaerobic digester, is to be used in an industrial scale operation to minimize disposal of food waste at incineration plants in Singapore. The aim of the present research was to evaluate freezing/thawing of food waste as a pre-treatment for its anaerobic digestion in the HASL system. The hydrolytic and fermentation processes in the acidogenic reactor were enhanced when food waste was frozen for 24 h at -20 deg. C and then thawed for 12 h at 25 deg. C (experiment) in comparison with fresh food waste (control). The highest dissolved COD concentrations in the leachate from the acidogenic reactors were 16.9 g/l on day 3 in the control and 18.9 g/l on day 1 in the experiment. The highest VFA concentrations in the leachate from the acidogenic reactors were 11.7 g/l on day 3 in the control and 17.0 g/l on day 1 in the experiment. The same volume of methane was produced during 12 days in the control and 7 days in the experiment. It gave the opportunity to diminish operational time of batch process by 42%. The effect of freezing/thawing of food waste as pre-treatment for its anaerobic digestion in the HASL system was comparable with that of thermal pre-treatment of food waste at 150 deg. C for 1 h. However, estimation of energy required either to heat the suspended food waste to 150 deg. C or to freeze the same quantity of food waste to -20 deg. C showed that freezing pre-treatment consumes about 3 times less energy than thermal pre-treatment.

Stabnikova, O. [School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)], E-mail: costab@ntu.edu.sg; Liu, X.Y.; Wang, J.Y. [School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

2008-07-01

142

Performance Validation and Scaling of a Capillary Membrane Solid-Liquid Separation System  

SciTech Connect

Algaeventure Systems (AVS) has previously demonstrated an innovative technology for dewatering algae slurries that dramatically reduces energy consumption by utilizing surface physics and capillary action. Funded by a $6M ARPA-E award, transforming the original Harvesting, Dewatering and Drying (HDD) prototype machine into a commercially viable technology has required significant attention to material performance, integration of sensors and control systems, and especially addressing scaling issues that would allow processing extreme volumes of algal cultivation media/slurry. Decoupling the harvesting, dewatering and drying processes, and addressing the rate limiting steps for each of the individual steps has allowed for the development individual technologies that may be tailored to the specific needs of various cultivation systems. The primary performance metric used by AVS to assess the economic viability of its Solid-Liquid Separation (SLS) dewatering technology is algae mass production rate as a function of power consumption (cost), cake solids/moisture content, and solids capture efficiency. An associated secondary performance metric is algae mass loading rate which is dependent on hydraulic loading rate, area-specific hydraulic processing capacity (gpm/in2), filter:capillary belt contact area, and influent algae concentration. The system is capable of dewatering 4 g/L (0.4%) algae streams to solids concentrations up to 30% with capture efficiencies of 80+%, however mass production is highly dependent on average cell size (which determines filter mesh size and percent open area). This paper will present data detailing the scaling efforts to date. Characterization and performance data for novel membranes, as well as optimization of off-the-shelf filter materials will be examined. Third party validation from Ohio University on performance and operating cost, as well as design modification suggestions will be discussed. Extrapolation of current productivities will be used to suggest a design for integration into commercial-scale production.

Rogers, S.; Cook, J.; Juratovac, J.; Goodwillie, J.; Burke, T.; Stuart, B., ed.

2011-10-25

143

The Interaction Between an Insoluble Particle and an Advancing Solid/Liquid Interface: Micro-Gravity Experiments and Theoretical Developments  

NASA Technical Reports Server (NTRS)

The interaction of an insoluble particle with an advancing solid/liquid interface (SLI) has been a subject of investigation for the past four decades. While the original interest stemmed from geology applications (e.g., frost heaving in soil), researchers soon realized that the complex science associated with such an interaction is relevant to many other scientific fields encompassing metal matrix composites (MMCs), high temperature superconductors, inclusion management in steel, growth of monotectics, and preservation of biological cells. During solidification of a liquid containing an insoluble particle, three distinct interaction phenomena have been experimentally observed: instantaneous engulfment of the particle, continuous pushing, and particle pushing followed by engulfment. It was also observed that for given experimental conditions and particle size there is a critical solidification velocity, V(sub cr), above which a particle is engulfed. During solidification of MMCs pushing leads to particle agglomeration at the grain boundaries and this has detrimental effects on mechanical properties of the casting. Consequently, the process must be designed for instantaneous engulfment to occur. This implies the development of accurate theoretical models to predict V(sub cr), and perform benchmark experiments to test the validity of such models. Although considerable progress has been made in understanding the pushing/engulfment phenomenon (PEP), its quantification in terms of the material and processing parameters remains a focus of research. Since natural convection currents occurring during terrestrial solidification experiments complicate the study of PEP, execution of experiments on the International Space Station (ISS) has been approved and funded by NASA. Extensive terrestrial (1g) experiments and preliminary micro-gravity (mu g) experiments on two space shuttle missions have been conducted in preparation for future experiments on the ISS. The investigated systems included metal-ceramic particles (pure aluminum - zirconia particles) and transparent organic - non-reactive particles (succinonitrile - polystyrene and biphenyl - glass). This paper will discuss the experimental results obtained in both lg and pg conditions and the influence of the natural convection on V(sub cr). A summary of past mathematical models and our recent theoretical developments will also be presented to explain the experimentally observed particle/SLI interaction.

Catalina, Adrian V.; Ssen, Subhayu; Stefanescu, Doru M.

2003-01-01

144

Investigations at the Solid-Liquid Interface by Scanning Tunneling Microscopy.  

NASA Astrophysics Data System (ADS)

Scanning tunneling microscopy (STM) has been used to investigate electrochemical processes at the solid-liquid interface. These investigations have been conducted in two specific areas, namely bioelectrochemistry and semiconductor electrochemistry. In the area of bioelectrochemistry, the STM was used to examine the morphology of the surface and determine the conditions necessary to electrochemically deposit a monolayer of nucleic acids. Parameters that were varied included: substrate material (graphite and gold), nucleic acid concentration (1.0-150 mug/ml), applied potential (between +2 and -2 V vs. Ag/AgCl) and potentiostatic pulse duration (10-180 s), and Tris buffer solution concentration (0.1-10 mM) and pH (7.3-8). Under most of the conditions studied, the deposited material was heterogeneously distributed over the surface as aggregates with small patches of isolated or loosely packed molecules. Conditions for repeatable homogeneous coverage were obtained by applying +1 V vs. Ag/AgCl to a gold substrate for one minute in a solution of 3 mM Tris buffer (pH 7.3) and a DNA concentration of 10 mug/ml. However, the homogeneous deposits consisted of a buffer salt complex with the nucleic acid. This salt complex prevented high resolution STM imaging of the nucleic acid. In the area of semiconductor electrochemistry, the STM was used to locally modify semiconducting surfaces on the nanometer scale. This was achieved by using the STM tip to either etch into the semiconductor surface or deposit gold onto the surface, while under solution. In the case of etching, the applied electric field existing between the tip and sample probably causes local oxidation of the surface. Subsequently, an etching solution removes the oxidized portion and leaves a depression in the sample. The oxide growth depended upon the length of time that the STM tip spent over a region. In the case of deposition, photoelectrochemical techniques were used to generate additional electrons in p-type GaAs(100). The STM tip bias was then used to bend the semiconductor bands to allow the photo -generated electrons to move toward the surface. This band bending occurred only beneath the STM tip and thus localized the gold deposition to this region. The size of the gold deposit depended upon the magnitude and duration of the potential applied to the STM tip.

Nagahara, Larry Akio

145

Application de l'cologie comportementale aux  

E-print Network

· Continuité humain-animal · Psychologie et anthropologie évolutionniste L'approche darwinienne 3 · Clairement 16 "Chaque guenille... a son torchon" Buston & Emlen 2003 PNAS 100: 8805-8810 17 Importance de l'intelligence

Blouin-Demers, Gabriel

146

Solid-Liquid Equilibria for the CO2 + R23 and N2O + R23 Systems  

NASA Astrophysics Data System (ADS)

A recently built experimental setup was employed for the estimation of the solid-liquid equilibria of alternative refrigerant systems. In this paper two binaries, i.e., carbon dioxide + trifluoromethane (CO2 + R23) and nitrous oxide + trifluoromethane (N2O + R23), were studied down to temperatures of 117 K. In order to check the reliability of the apparatus, the triple points of the pure fluids contained in the mixture were measured, revealing good consistency with the literature. The results obtained for the mixtures were interpreted by means of the Schrder equation.

Nicola, Giovanni Di; Giuliani, Giuliano; Polonara, Fabio; Santori, Giulio; Stryjek, Roman

2010-10-01

147

Bourses aux cycles suprieurs Manolo Dulva Hina  

E-print Network

Bourses aux cycles supérieurs Banque Nationale 2007 2008 10 000 $ 10 000 $ 10 000 $ 10 000 $ Manolo 1 500 $ Magdalena Stanescu Doctorat génie FIMQ ­ Bourse Hervé Aubin 2006 5 000 $ Claude Bruxelle

Québec, Université du

148

Pathologie vgtale (synthse) Rsistances aux herbicides  

E-print Network

Pathologie v�g�tale (synth�se) R�sistances aux herbicides chez les mauvaises herbes H Darmency J; accept� le 27 mai 1990) R�sum� L'usage inconsid�r� des herbicides pour un d�sherbage syst�matique des grandes cultures a conduit � l'apparition de mauvaises herbes r�sistantes. Huit familles d'herbicides

Boyer, Edmond

149

Extended thermodynamical analysis of a motion of the solid-liquid interface in a rapidly solidifying alloy  

NASA Astrophysics Data System (ADS)

On the basis of extended irreversible thermodynamics [D. Jou, J. Casas-Vazquez, and G. Lebon, Rep. Prog. Phys. 51, 1005 (1988); 62, 1035 (1999)] an analysis of the solid-liquid interface motion is presented. In addition to the formalism of the classic irreversible thermodynamics of Onsager and Prigogine, a space of independent thermodynamic variables is extended by introducing the solute diffusion flux in consistency with the extended thermodynamic approach to local nonequilibrium processes. Considering the rapid solidification front motion, when the crystal growth velocity is of the order or even greater than the speed for solute diffusion, a local nonequilibrium at the solid-liquid interface and inside bulk liquid is adopted by the model. Taking into account the solute diffusive speed at the phase interface and the finite speed of solute diffusive propagation in bulk system, the equations for thermodynamical fluxes, conjugated driving forces, the Gibbs free energy change on solidification, and liquidus line slope are derived. A discussion of the outcomes predicted by the present model and a comparative analysis of the model predictions with experimental data are made.

Galenko, Peter

2002-04-01

150

Probing charge screening dynamics and electrochemical processes at the solid-liquid interface with electrochemical force microscopy.  

PubMed

The presence of mobile ions complicates the implementation of voltage-modulated scanning probe microscopy techniques such as Kelvin probe force microscopy (KPFM). Overcoming this technical hurdle, however, provides a unique opportunity to probe ion dynamics and electrochemical processes in liquid environments and the possibility to unravel the underlying mechanisms behind important processes at the solid-liquid interface, including adsorption, electron transfer and electrocatalysis. Here we describe the development and implementation of electrochemical force microscopy (EcFM) to probe local bias- and time-resolved ion dynamics and electrochemical processes at the solid-liquid interface. Using EcFM, we demonstrate contact potential difference measurements, consistent with the principles of open-loop KPFM operation. We also demonstrate that EcFM can be used to investigate charge screening mechanisms and electrochemical reactions in the probe-sample junction. We further establish EcFM as a force-based imaging mode, allowing visualization of the spatial variability of sample-dependent local electrochemical properties. PMID:24846328

Collins, Liam; Jesse, Stephen; Kilpatrick, Jason I; Tselev, Alexander; Varenyk, Oleksandr; Okatan, M Baris; Weber, Stefan A L; Kumar, Amit; Balke, Nina; Kalinin, Sergei V; Rodriguez, Brian J

2014-01-01

151

Fluoroponytailed crown ethers and quaternary ammonium salts as solid-liquid phase transfer catalysts in organic synthesis.  

PubMed

Fluorous derivatives of dibenzo-18-crown-6 ether were prepared, and then successfully applied in representative solid-liquid phase transfer catalysis reactions, which were performed in standard organic solvents, such as chlorobenzene and toluene, as well as in fluorous solvents, such as perfluoro-1,3-dimethylcyclohexane. It was clearly shown that properly designed fluoroponytailed crown ethers could promote the disintegration of the crystal lattice of alkali salts, and transfer anions from the solid surface into an apolar, non-coordinating perfluorocarbon phase, for phase transfer catalysis reactions in organic synthesis. Furthermore, 3,5-bis(perfluorooctyl)benzyl bromide and triethylamine were reacted under mild conditions to provide an analogue of the versatile phase transfer catalyst, benzyltriethylammonium chloride, containing two fluoroponytails. This fluoroponytailed quaternary ammonium salt was also successfully employed as a catalyst in a variety of organic reactions conducted under solid-liquid phase transfer catalysis conditions, without a perfluorocarbon phase. Thus, being both hydrophobic and lipophobic, fluorous crown ethers and ammonium salts, could be rapidly recovered in quantitative yields, and reused without loss of activity, over several reaction cycles. PMID:21928010

Pozzi, Gianluca; Fish, Richard H

2012-01-01

152

Molecular dynamics study of melting curve, entropy of fusion and solid-liquid interfacial energy of cobalt under pressure  

NASA Astrophysics Data System (ADS)

We performed molecular dynamics (MD) simulations with the two embedded atom method (EAM) potentials to calculate the melting curves of cobalt over a wide range of pressure. Zhou's EAM potential can produce satisfying results, in better agreement with the experiment compared with Pun's. Based on Zhou's potential, we simulated the melting of Co with two approaches, i.e., the one-phase (hysteresis) method and two-phase (solid-liquid coexistence) method. Both approaches can effectively reduce the superheating, and their results are in the close proximity at the applied pressures. With the one-phase method, during the investigation of the entropy of fusion of Co, we found that with the pressure increasing, the entropy of fusion decreases rapidly first and then oscillates with pressure; when the pressure is beyond 100 GPa, the entropy of fusion shows less pressure effect. When taking account of the solid-liquid interfacial energy at different pressures, we found that it increases monotonically with pressure, and can be well described as a fifth-order polynomial relation. Moreover, the thermal equation of state (EOS) and the temperature dependence of atomic structures of Co have been obtained successfully.

Zhang, Wen-jin; Peng, Yu-feng; Liu, Zhong-li

2014-05-01

153

Effect of graphene layer thickness and mechanical compliance on interfacial heat flow and thermal conduction in solid-liquid phase change materials.  

PubMed

Solid-liquid phase change materials (PCMs) are attractive candidates for thermal energy storage and electronics cooling applications but have limited applicability in state-of-the-art technologies due to their low intrinsic thermal conductivities. Recent efforts to incorporate graphene and multilayer graphene into PCMs have led to the development of thermal energy storage materials with remarkable values of bulk thermal conductivity. However, the full potential of graphene as a filler material for the thermal enhancement of PCMs remains unrealized, largely due to an incomplete understanding of the physical mechanisms that govern thermal transport within graphene-based nanocomposites. In this work, we show that the number of graphene layers (n) within an individual graphene nanoparticle has a significant effect on the bulk thermal conductivity of an organic PCM. Results indicate that the bulk thermal conductivity of PCMs can be tuned by over an order of magnitude simply by adjusting the number of graphene layers (n) from n = 3 to 44. Using scanning electron microscopy in tandem with nanoscale analytical techniques, the physical mechanisms that govern heat flow within a graphene nanocomposite PCM are found to be nearly independent of the intrinsic thermal conductivity of the graphene nanoparticle itself and are instead found to be dependent on the mechanical compliance of the graphene nanoparticles. These findings are critical for the design and development of PCMs that are capable of cooling next-generation electronics and storing heat effectively in medium-to-large-scale energy systems, including solar-thermal power plants and building heating and cooling systems. PMID:24983698

Warzoha, Ronald J; Fleischer, Amy S

2014-08-13

154

Nanostructuring of Self-Assembled Porphyrin Networks at a Solid/Liquid Interface: Local Manipulation under Global Control.  

PubMed

Molecules of (5,10,15,20-tetraundecylporphyrinato)-copper(II) [(TUP)Cu] can self-assemble into four different polymorphs at the interface between highly oriented pyrolytic graphite and 1-octanoic acid. Scanning tunneling microscopy (STM) reveals that it is possible to combine the global control over monolayer structure, provided by the composition and concentration of the supernatant solution, with local control, from nanomanipulation by the STM tip. In the initially formed monolayer, with a polymorph composition governed by the concentration of (TUP)Cu in the supernatant solution, the exchange of molecules physisorbed at the solid/liquid interface with those in the liquid is very limited. By using a nanoshaving procedure at the tip, defects are created in the monolayer, and these serve as local manipulation sites to create domains of higher or lower molecular density, and to incorporate a second molecular species, (TUP)Co into the monolayer of (TUP)Cu. PMID:25146424

Coenen, Michiel J J; Khoury, Tony; Crossley, Maxwell J; Hendriksen, Bas L M; Elemans, Johannes A A W; Speller, Sylvia

2014-11-10

155

Free-Surface Optical Scattering as an Indicator of the Shock-Induced Solid-Liquid Phase Transition in Tin  

SciTech Connect

When highly polished metal surfaces melt upon release after shock loading, they exhibit features that suggest significant surface changes accompany the phase transition. The reflection of light from such surfaces changes from specular (pre-shock) to diffuse upon melting. A familiar manifestation of this phenomenon is the loss of signal light in VISAR measurements, which occurs at pressures high enough to melt the free surface. Unlike many other potential material phase-sensitive diagnostics (e.g., reflectometry, conductivity) that show relatively small (1%10%) changes, the specularity of reflection provides a more sensitive and definitive indication of the solid-liquid phase transition. Data will be presented that support the hypothesis that specularity changes indicate melt in a way that can be measured easily and unambiguously.

Stevens, G. D.; Lutz, S. S.; Marshall, B. R.; Turley, W. D.; Veeser, L. R.; Furlanetto, M. R.; Hixson, R. S.; Holtkamp, D. B.; Jensen, B. J.; Rigg, P. A.; Wilke, M. D.

2008-07-01

156

Inferences about radionuclide mobility in soils based on the solid/liquid partition coefficients and soil properties.  

PubMed

To assist transport modeling in assessments of the radiological impact of a geological repository for radioactive wastes, the mobility of various elements was studied in arable and wetland soils in the Forsmark region, Sweden. Pore water and total element contents were determined for five types of unconsolidated deposits (regolith), spanning a wide range of soil properties with respect to pH and organic matter content. Two soil depths were sampled to capture element mobility in regolith layers affected and unaffected by soil-forming processes. The solid/liquid partition coefficients (K d values) for most elements varied significantly among regolith types. For most elements, the observed variations in K d values could be explained by variations in soil properties. For many elements, mobility increased with decreasing soil pH. The results provide a significant addition of data on radionuclide retention in soils, taking account of soil properties and processes. PMID:23619799

Sohlenius, Gustav; Saetre, Peter; Nordn, Sara; Grolander, Sara; Sheppard, Steve

2013-05-01

157

Real-time observation of the solid-liquid-vapor dissolution of individual tin(IV) oxide nanowires.  

PubMed

The well-known vapor-liquid-solid (VLS) mechanism results in high-purity, single-crystalline wires with few defects and controllable diameters, and is the method of choice for the growth of nanowires for a vast array of nanoelectronic devices. It is of utmost importance, therefore, to understand how such wires interact with metallic interconnects-an understanding which relies on comprehensive knowledge of the initial growth process, in which a crystalline wire is ejected from a metallic particle. Though ubiquitous, even in the case of single elemental nanowires the VLS mechanism is complicated by competing processes at multiple heterogeneous interfaces, and despite decades of study, there are still aspects of the mechanism which are not well understood. Recent breakthroughs in studying the mechanism and kinetics of VLS growth have been strongly aided by the use of in situ techniques, and would have been impossible through other means. As well as several systematic studies of nanowire growth, reports which focus on the role and the nature of the catalyst tip reveal that the stability of the droplet is a crucial factor in determining nanowire morphology and crystallinity. Additionally, a reverse of the VLS process dubbed solid-liquid-vapor (SLV) has been found to result in the formation of cavities, or "negative nanowires". Here, we present a series of heating studies conducted in situ in the transmission electron microscope (TEM), in which we observe the complete dissolution of metal oxide nanowires into the metal catalyst particles at their tips. We are able to consistently explain our observations using a solid-liquid-vapor (SLV) type mechanism in which both evaporation at the liquid-vapor interface and adhesion of the catalyst droplet to the substrate surface contribute to the overall rate. PMID:24818706

Hudak, Bethany M; Chang, Yao-Jen; Yu, Lei; Li, Guohua; Edwards, Danielle N; Guiton, Beth S

2014-06-24

158

Monte Carlo simulations of the solid-liquid transition in hard spheres and colloid-polymer mixtures  

E-print Network

Monte Carlo simulations at constant pressure are performed to study coexistence and interfacial properties of the liquid-solid transition in hard spheres and in colloid-polymer mixtures. The latter system is described as a one-component Asakura-Oosawa (AO) model where the polymer's degrees of freedom are incorporated via an attractive part in the effective potential for the colloid-colloid interactions. For the considered AO model, the polymer reservoir packing fraction is eta_p^r=0.1 and the colloid-polymer size ratio is q=sigma_p/\\sigma=0.15 (with sigma_p and sigma the diameter of polymers and colloids, respectively). Inhomogeneous solid-liquid systems are prepared by placing the solid fcc phase in the middle of a rectangular simulation box creating two interfaces with the adjoined bulk liquid. By analyzing the growth of the crystalline region at various pressures and for different system sizes, the coexistence pressure p_co is obtained, yielding p_co=11.576 k_BT/sigma^3 for the hard sphere system and p_co=8.0 k_BT/sigma^3 for the AO model (with k_B the Boltzmann constant and T the temperature). Several order parameters are introduced to distinguish between solid and liquid phases and to describe the interfacial properties. From the capillary-wave broadening of the solid-liquid interface, the interfacial stiffness is obtained for the (100) crystalline plane, giving the values gamma=0.49 k_BT/sigma^2 for the hard-sphere system and gamma=0.95 k_BT/sigma^2 for the AO model.

T. Zykova-Timan; J. Horbach; K. Binder

2010-03-05

159

SOLID-LIQUID PHASE TRANSFER CATALYZED SYNTHESIS OF CINNAMYL ACETATE-KINETICS AND ANALYSIS OF FACTORS AFFECTING THE REACTION IN A BATCH REACTOR  

EPA Science Inventory

The use of solid-liquid phase transfer catalysis has an advantage of carrying out reaction between two immiscible substrates, one in solid phase and the other in liquid phase, with high selectivity and at relatively low temperatures. In this study we investigated the synthesis ci...

160

Study of the Fate of Lipophilic Wood Extractives During Acid Sulphite Pulping Process by Ultrasonic Solid-Liquid Extraction and Gas Chromatography Mass Spectrometry  

Microsoft Academic Search

Lipophilic extractives in dissolving pulp are still a big concern for pulp industries due to their detrimental effect on the quality of pulp. Since lipophilic extractives remaining in pulp are trapped in low-accessible fiber structures, effective extraction methods need to be established for studying their fate in the process. A simple, ultrasonic, solid liquid extraction established in this study was

Kessy F. Kilulya; Titus A. M. Msagati; Bhekie B. Mamba; J. Catherine Ngila; Tamara Bush

2012-01-01

161

Highly diastereoselective monoalkylation and Michael addition of N-(diphenylmethylene)glycinesultam under solidliquid phase-transfer catalysis conditions using potassium carbonate as base  

Microsoft Academic Search

Treatment of a sultam-derived N-(diphenylmethylene)glycinate equivalent 1 with activated (allylic and propargylic) organic bromides and with Michael acceptors under solidliquid phase-transfer catalysis conditions, using potassium carbonate as base, affords the monoalkylated compounds with high diastereoselectivity (>97% d.e.).

Anna Lpez; Roser Pleixats

1998-01-01

162

Molecular simulation of biomaterials and biomolecules at the solid-liquid interface  

E-print Network

Biomaterials and biomineralization have been successfully utilized in a broad variety of technical applications. Properties of natural biopolymers, such as the ability to control the nucleation, growth, and organization ...

Kottmann, Stephen Thomas

2008-01-01

163

Hydrodynamic-induced enantiomeric enrichment of self-assemblies: Role of the solid-liquid interface in chiral nucleation and seeding  

NASA Astrophysics Data System (ADS)

A simple hydrodynamic model has been developed to explain the experimentally observed chirality selection in stirred solutions of self-assembling achiral dyes. Selection depends on the stirring direction: the dichroic signal reverses its shape in clockwise or anti-clockwise rotations. Our model investigates the possible role of the liquid-solid interface in nucleating, growing, and transferring to the bulk of chiral seeds. The nucleation step requires a double modulation of the hydrodynamic field exhibiting different velocity along two orthogonal axes. Under a series of restrictions, such a condition is easily met at the solid-liquid interface and it is dictated by the boundary conditions and geometry of stirring. In stagnant conditions, growing helices made-up of self-assembled achiral dyes have no chiral preference forming a racemic mixture that contains identical amount of right-handed (R) and left-handed (L) configurations. The application of a hydrodynamic torque (related to the velocity gradient and width of the helix) breaks down the original symmetry, a further velocity gradient perpendicular to the first one ensures, after averaging, a slightly different population of R and L conformations. The yields of the hydrodynamic-induced chirality excess are extremely tiny, hence the suggested mechanism is significant only if next chirality amplification processes are efficient. Again, hydrodynamics provides a tool for the detachment of weakly bound aggregates once they have reached a critical length. Aggregates are transported in the bulk where the ripening process goes to completion. The efficiency of the surface catalytic effect strongly depends on the aggregate-surface sticking energy, reaching a maximum at intermediate sticking energies (of order of 10 kT). Numerical estimates show that the proposed mechanism is rather efficient, giving rise to entatiomeric excesses near (but smaller than) those experimentally found.

Raudino, Antonio; Pannuzzo, Martina

2012-10-01

164

Multiscale Engineering of solid-liquid interfaces Wednesday October 27, 2010, Babbio 122, 10am  

E-print Network

enhancements of critical heat flux are typically found for hydrophilic networks featuring hydrophobic islands, with applications in coating technologies and heat transport. The first part of the talk is focused on the formation hydrophilic surface, the measured critical heat flux and heat transfer coefficients of the enhanced surfaces

Fisher, Frank

165

Solid-Liquid Equilibrium Modelling and Stability Tests for Triacylglycerols Mixtures  

Microsoft Academic Search

Computer-Aided Mixture Design for product development can take advantage from equilibrium modelling. Systems composed by triacylglycerols (TAG) mixtures are widely used for many applications (foods, cosmetics, pharmaceutical and lubricants) and their end-use properties are very close related to phase behaviour (melting and crystallization). Such molecules can have different polymorphisms in solid state, leading to a lack of intersolubility and consequently

Moises T. dos Santos; Galo A. C. Le Roux; Xavier Joulia; Vincent Gerbaud

2009-01-01

166

Pascale Bonnemre Considrations relatives aux reprsentations des substances  

E-print Network

Pascale Bonnemère Considérations relatives aux représentations des substances corporelles en : Bonnemère Pascale. Considérations relatives aux représentations des substances corporelles en Nouvelle Substances in New Guinea. -- Beliefs about bodily substances in some twenty New Guinea societies seem to form

Boyer, Edmond

167

Solid-liquid phase coexistence of alkali nitrates from molecular dynamics simulations.  

SciTech Connect

Alkali nitrate eutectic mixtures are finding application as industrial heat transfer fluids in concentrated solar power generation systems. An important property for such applications is the melting point, or phase coexistence temperature. We have computed melting points for lithium, sodium and potassium nitrate from molecular dynamics simulations using a recently developed method, which uses thermodynamic integration to compute the free energy difference between the solid and liquid phases. The computed melting point for NaNO3 was within 15K of its experimental value, while for LiNO3 and KNO3, the computed melting points were within 100K of the experimental values [4]. We are currently extending the approach to calculate melting temperatures for binary mixtures of lithium and sodium nitrate.

Jayaraman, Saivenkataraman

2010-03-01

168

Modelling of a thin mushy layer evolution during binary solid-liquid interactions  

Microsoft Academic Search

Further development of the Brody-Flemings approximation in application to a thin mushy zone at the interface between binary\\u000a liquid and solid phases, typical in the context of corium evolution in the reactor pressure vessel during severe accidents\\u000a at nuclear power plants, is presented. The main assumption of the Brody-Flemings approximation concerning local equilibrium\\u000a between the solid and liquid phases in

M. S. Veshchunov

2009-01-01

169

Study on solid-liquid two-phase unsteady flow characteristics with different flow rates in screw centrifugal pump  

NASA Astrophysics Data System (ADS)

The screw centrifugal pump is used as an object, and the unsteady numerical simulation of solid-liquid two-phase flow is carried out under different flow rate conditions in one circle by choosing the two-phase flow of sand and water as medium, using the software FLUENT based on the URANS equations, combining with sliding mesh method, and choosing the Mixture multiphase flow model and the SIMPLE algorithm. The results show that, with the flow rate increasing, the change trends for the pressure on volute outlet are almost constant, the fluctuation trends of the impeller axial force have a little change, the pressure and the axial force turn to decrease on the whole, the radial force gradually increases when the impeller maximum radius passes by half a cycle near the volute outlet, and the radial force gradually decreases when the maximum radius passes by the other half a cycle in a rotation cycle. The distributions of the solid particles are very uneven under a small flow rate condition on the face. The solid particles under a big flow rate condition are distributed more evenly than the ones under a small flow rate condition on the back. The theoretical basis and reference are provided for improving its working performance.

Li, R. N.; Y Wang, H.; Han, W.; Ma, W.; Shen, Z. J.

2013-12-01

170

Electrochemical determination of the glass transition temperature of thin polyelectrolyte brushes at solid-liquid interfaces by impedance spectroscopy.  

PubMed

Devising strategies to assess the glass transition temperature (Tg) of polyelectrolyte assemblies at solid-electrolyte interfaces is very important to understand and rationalize the temperature-dependent behavior of polyelectrolyte films in a wide range of settings. Despite the evolving perception of the importance of measuring Tg under aqueous conditions in thin film configurations, its straightforward measurement poses a challenging situation that still remains elusive in polymer and materials science. Here, we describe a new method based on electrochemical impedance spectroscopy (EIS) to estimate the glass transition temperature of planar polyelectrolyte brushes at solid-liquid interfaces. To measure Tg, the charge transfer resistance (Rct) of a redox probe diffusing through the polyelectrolyte brush was measured, and the temperature corresponding to the discontinuous change in Rct was identified as Tg. Furthermore, we demonstrate that impedance measurements not only facilitate the estimation of Tg but also enable a reliable evaluation of the transport properties of the polymeric interface, i.e., determination of diffusion coefficients, close to the thermal transition. We consider that this approach bridges the gap between electrochemistry and the traditional tools used in polymer science and offers new opportunities to characterize the thermal behavior of complex polymeric interfaces and macromolecular assemblies. PMID:23808656

Alonso-Garca, Teodoro; Rodrguez-Presa, Mara Jos; Gervasi, Claudio; Moya, Sergio; Azzaroni, Omar

2013-07-16

171

Interactions of PAMAM dendrimers with SDS at the solid-liquid interface.  

PubMed

This work addresses structural and nonequilibrium effects of the interactions between well-defined cationic poly(amidoamine) PAMAM dendrimers of generations 4 and 8 and the anionic surfactant sodium dodecyl sulfate (SDS) at the hydrophilic silica-water interface. Neutron reflectometry and quartz crystal microbalance with dissipation monitoring were used to reveal the adsorption from premixed dendrimer/surfactant solutions as well as sequential addition of the surfactant to preadsorbed layers of dendrimers. PAMAM dendrimers of both generations adsorb to hydrophilic silica as a compact monolayer, and the adsorption is irreversible upon rinsing with salt solution. SDS adsorbs on the dendrimer layer and at low bulk concentrations causes the expansion of the dendrimer layers on the surface. When the bulk concentration of SDS is increased, the surfactant layer consists of aggregates or bilayer-like structures. The adsorption of surfactant is reversible upon rinsing, but slight changes of the structure of the preadsorbed PAMAM monolayer were observed. The adsorption from premixed solutions close to charge neutrality results in thick multilayers, but the surface excess is lower when the bulk complexes have a net negative charge. A critical examination of the pathway of adsorption for the interactions of SDS with preadsorbed PAMAM monolayers and premixed PAMAM/SDS solutions with hydrophilic silica revealed that nonequilibrium effects are important only in the latter case, and the application of a thermodynamic model to such experimental data would be inappropriate. PMID:23556998

Arteta, Marianna Yanez; Eltes, Felix; Campbell, Richard A; Nylander, Tommy

2013-05-14

172

Thermodynamic and rheological properties of solid-liquid systems in coal processing. Final technical report  

SciTech Connect

The work on this project was initiated on September 1, 1991. The project consisted of two different tasks: (1) Development of a model to compute viscosities of coal derived liquids, and (2) Investigate new models for estimation of thermodynamic properties of solid and liquid compounds of the type that exist in coal, or are encountered during coal processing. As for task 1, a model for viscosity computation of coal model compound liquids and coal derived liquids has been developed. The detailed model is presented in this report. Two papers, the first describing the pure liquid model and the second one discussing the application to coal derived liquids, are expected to be published in Energy & Fuels shortly. Marginal progress is reported on task 2. Literature review for this work included compilation of a number of data sets, critical investigation of data measurement techniques available in the literature, investigation of models for liquid and solid phase thermodynamic computations. During the preliminary stages it was discovered that for development of a liquid or solid state equation of state, accurate predictive models for a number of saturation properties, such as, liquid and solid vapor pressures, saturated liquid and solid volumes, heat capacities of liquids and solids at saturation, etc. Most the remaining time on this task was spent in developing predictive correlations for vapor pressures and saturated liquid volumes of organic liquids in general and coal model liquids in particular. All these developments are discussed in this report. Some recommendations for future direction of research in this area are also listed.

Kabadi, V.N.

1995-06-30

173

Discussion of parameters associated with the ultrasonic solid-liquid extraction for elemental analysis (total content) by electrothermal atomic absorption spectrometry. An overview.  

PubMed

Ultrasonic solid-liquid extraction (USLE) of trace metals from biological and environmental samples and its subsequent quantification by electrothermal atomic absorption spectrometry (ET-AAS) is nowadays an emerging methodology in the analytical laboratory. However, this methodology is far from maturity as can be readily demonstrated from the controversial data reported by different workers. In the light of our own experience and a survey of published data, a general approach for USLE-ET-AAS is discussed, taking into account the different variables which affect ultrasonic solid-liquid extraction, namely, the ultrasonic device chosen for ultrasonic extraction (e.g. ultrasonic bath or ultrasonic probe), particle size, acid concentration, sonication time and sonication amplitude, sample mass and analyte-matrix binding. PMID:15491886

Capelo, J L; Maduro, C; Vilhena, C

2005-02-01

174

Thermodynamic and rheological properties of solid-liquid systems in coal processing. Quarterly technical report, March 1, 1992--May 31, 1992  

SciTech Connect

In this report we present two data sets that have been compiled to assist in the model developments for solid-liquid equilibria and viscosities of coal derived systems. The first one is on vapor pressures of solid aromatics and the second one consists of viscosities of pure model compounds and some mixtures. These databanks are ready for usage in model development and are summarized in Tables 1 and 2. Literature is being searched to compile similar data for high pressure liquid compressibilities, liquid and solid heat capacities and solid-liquid equilibria for model compound systems. Literature search is also containing to investigate available viscosity models. Once this is completed a few models will be selected for evaluation and consideration as candidates for extension to coal liquids.

Kabadi, V.N.; Ilias, S.

1992-12-31

175

Temperature-Controlled Catalyst Recycling: New Protocols Based upon Temperature-Dependent Solubilities of Fluorous Compounds and Solid\\/Liquid Phase Separations  

Microsoft Academic Search

The absolute solubilities of fluorous compounds can be tailored by varying the lengths of the (CF2)\\u000a n?1CF3 (Rfn\\u000a )\\u000a segments. Many such compounds exhibit immense solubility increases in organic solvents or neat liquid reactants\\u000a upon heating. Suitably designed fluorous catalysts can therefore be employed under homogeneous conditions\\u000a at elevated temperatures, and recovered by solid\\/liquid phase separation at lower temperatures. Expensive

John A. Gladysz; Verona Tesevic

176

Effects of tilting mirrors on the solidliquid interface during floating zone growth using tilting-mirror-type infrared-heating image furnace  

Microsoft Academic Search

The effects of tilting the mirrors of a tilting-mirror-type image furnace were examined for the crystal growth of rutile by the infrared-heating floating zone (FZ) method. The mirrors were tilted from horizontal to 20 in 5 steps to examine the change of the solidliquid interface during crystal growth. The molten zone was quenched during the FZ growth. A small amount

Satoshi Watauchi; Masanori Nagao; Takashi Watanabe; Isamu Shindo; Isao Tanaka

2010-01-01

177

Phase-field model of solid-liquid phase transition with density difference and latent heat in velocity and elastic fields.  

PubMed

We present a phase-field model of solid-liquid transitions with inhomogeneous temperature in one-component systems, including hydrodynamics and elasticity. Our model can describe plastic deformations at large elastic strains. We use it to investigate the melting of a solid domain, accounting for the latent heat effect, where there appears a velocity field in liquid and an elastic field in solid. We present simulation results in two dimensions for three cases of melting. First, a solid domain is placed on a heated wall, which melts mostly near the solid-liquid-wall contact region. Second, a solid domain is suspended in a warmer liquid under shear flow, which rotates as a whole because of elasticity and melts gradually. Cooling of the surrounding liquid is accelerated by convection. Third, a solid rod is under high compression in liquid, where slips appear from the solid-liquid interface, leading to a plastic deformation. Subsequently, melting starts in the plastically deformed areas, eventually resulting in the fracture of the rod into pieces. In these phase-transition processes, the interface temperature is kept nearly equal to the coexisting temperature T(cs)(p) away from the heated wall, but this local equilibrium is not attained near the the contact region. We also examine a first-order liquid-liquid phase transition under heating from a boundary in one-component liquids. PMID:21599166

Takae, Kyohei; Onuki, Akira

2011-04-01

178

Solid-liquid phase diagrams for the determination of the solid state nature of both polymorphs of (RS)-2-(2-oxo-pyrrolidin-1-yl)-butyramide.  

PubMed

This work focuses on the determination of the solid state nature of (RS)-2-(2-oxo-pyrrolidin-1-yl)-butyramide (Etiracetam), the racemic intermediate of (S)-2-(2-oxo-pyrrolidin-1-yl)-butyramide, an Active Pharmaceutical Ingredient, marketed under the name Levetiracetam(). It is show how this information can easily be extracted from solid-liquid phase diagrams of the racemic system. As two polymorphs of Etiracetam are known (Forms I and II), the analyses have been performed considering both polymorphs. The solid-liquid phase diagrams are determined experimentally, using Differential Scanning Calorimetry, and theoretically, using the Prigogine-Defay and Schroeder-Van Laar equations. Only the phase diagram involving the polymorph stable at higher temperatures (Form II) can be constructed experimentally. The theoretical phase diagram involving this polymorph compares well with the experimental one, thus allowing the use of theoretical equations for the prediction of the solid-liquid phase diagram involving Form I, which is meta-stable above 30.5 C. Our findings confirm that both polymorphs are racemic compounds, which is also confirmed by XRPD analysis. PMID:22846407

Herman, Christelle; Haut, Benot; Aerts, Luc; Leyssens, Tom

2012-11-01

179

Spectrofluorimetric determination of melatonin in kernels of four different Pistacia varieties after ultrasound-assisted solid-liquid extraction  

NASA Astrophysics Data System (ADS)

Melatonin is normally consumed to regulate the body's biological cycle. However it also has therapeutic properties, such as anti-tumor, anti-aging and protects the immune system. There are some reports on the presence of melatonin in edible kernels such as walnuts, but the extraction of melatonin from pistachio kernels is reported here for the first time. For this, the methanolic extract of pistachio kernels was exposed to gas chromatography/mass spectrometry analysis which confirmed the presence of melatonin. A fluorescence-based method was applied for the determination of melatonin in different extracts. When excited at ? = 275 nm, the fluorescence emission intensity of melatonin was measured at ? = 366 nm. Ultrasound-assisted solid-liquid extraction was used for the extraction of melatonin from pistachio kernels prior to fluorimetric determination. To achieve the highest extraction recovery, the main parameters affecting the extraction efficiency such as extracting solvent type and volume, temperature, sonication time and pH were evaluated. Under the optimized conditions, a linear dependence of fluorescence intensity on melatonin concentration was observed in the range of 0.0040-0.160 ?g mL-1, with a detection limit of 0.0036 ?g mL-1. This method was applied successfully for measuring and comparing the melatonin content in the kernels of four different varieties of Pistacia including Ahmad Aghaei, Akbari, Kalle Qouchi and Fandoghi. In addition, the results obtained were compared with those obtained using GC/MS. A good agreement was observed indicating the reliability of the proposed method.

Oladi, Elham; Mohamadi, Maryam; Shamspur, Tayebeh; Mostafavi, Ali

2014-11-01

180

a Scanning Probe Microscopy Study of Single and Double Stranded DNA at the Solid-Liquid Interface  

NASA Astrophysics Data System (ADS)

Scanning Probe Microscopy (SPM), which includes Scanning Tunneling Microscopy (STM) and Atomic Force Microscopy (AFM), has been used to image biomolecules at the solid -liquid interface with an electrochemical technique. Generally, the imaging surface (the working electrode) is held at a potential of 245-295 mV with respect to solution (SCE) via an emf between the surface and a Pt wire (the counter electrode). The potential facilitates adsorption of the molecules from solution onto the imaging surface and adherence. In order to study soft, biologically interesting molecules with the SPM, a flat, clean, imaging surface is needed. A technique has been developed which allows one to produce a reasonably flat, very clean substrate by physical vapor deposition (PVD) of Au onto muscovite mica. These Au films, which grow in the (111) orientation, typically, have a R.M.S. surface roughness value of less than 2 nm over an area of a few micrometers squared and average grain sizes of approximately 1/2 mu m to 1 mum. STM images of single stranded DNA (11 and 20 bases long) have shown that, at the Au(111)-aqueous solution interface, it tends to be linear and helical, lying along the symmetry directions of the Au(111) surface, with a base spacing of 0.35 +/- 0.04 nm. STM images of double stranded DNA show a groove periodicity consistent with a 36^circ twist angle. Complexes of both double and single stranded DNA with the drug cisplatin, have been studied and it has been learned that for the single stranded adduct 3 distinct forms occur: two are kinked with a 89 +/- 9^circ and 146 +/- 5^circ bending angle and 1 is linear and 1 nm longer than for non-complexed single stranded DNA. The double stranded cisplatin adduct is marked by an anisotropy not seen in normal DNA. Microcircular DNA of various radii of curvature has been imaged offering more proof for its existence.

Derose, James Anthony

181

Order-parameter-aided temperature-accelerated sampling for the exploration of crystal polymorphism and solid-liquid phase transitions.  

PubMed

The problem of predicting polymorphism in atomic and molecular crystals constitutes a significant challenge both experimentally and theoretically. From the theoretical viewpoint, polymorphism prediction falls into the general class of problems characterized by an underlying rough energy landscape, and consequently, free energy based enhanced sampling approaches can be brought to bear on the problem. In this paper, we build on a scheme previously introduced by two of the authors in which the lengths and angles of the supercell are targeted for enhanced sampling via temperature accelerated adiabatic free energy dynamics [T. Q. Yu and M. E. Tuckerman, Phys. Rev. Lett. 107, 015701 (2011)]. Here, that framework is expanded to include general order parameters that distinguish different crystalline arrangements as target collective variables for enhanced sampling. The resulting free energy surface, being of quite high dimension, is nontrivial to reconstruct, and we discuss one particular strategy for performing the free energy analysis. The method is applied to the study of polymorphism in xenon crystals at high pressure and temperature using the Steinhardt order parameters without and with the supercell included in the set of collective variables. The expected fcc and bcc structures are obtained, and when the supercell parameters are included as collective variables, we also find several new structures, including fcc states with hcp stacking faults. We also apply the new method to the solid-liquid phase transition in copper at 1300 K using the same Steinhardt order parameters. Our method is able to melt and refreeze the system repeatedly, and the free energy profile can be obtained with high efficiency. PMID:24907992

Yu, Tang-Qing; Chen, Pei-Yang; Chen, Ming; Samanta, Amit; Vanden-Eijnden, Eric; Tuckerman, Mark

2014-06-01

182

Imaging the molecular dimensions and oligomerization of protein molecules at the solid-liquid interface by surface oriented molecular sizing (SOMS) microscopy  

NASA Astrophysics Data System (ADS)

The structure and behavior of proteins at the solid/liquid interface is of great scientific interest. It has application both to fundamental biochemical understanding, as well as to biotechnological purposes. Interfaces play a critical role in many physiological processes. The mechanism of protein adsorption to surfaces is not very well understood. The current model put forth in much of the literature assumes a two step model. In the first step of this model the protein collides with the surface and adsorbs if its energy is sufficient to overcome the free energy of desorption of surface adsorbed solvent. The second step is often assumed to involve significant conformational change of the secondary and tertiary structure of the protein or enzyme, akin to denaturation. This unfolding of the protein would tend to indicate that loss of function would occur concomitantly, but studies have found very little loss in activity upon adsorption for a number of different protein systems. The recent development of the atomic force microscope (AFM) offers another tool for the examination of protein structure at liquid/solid interfaces. For atomically flat crystals the AFM has been used to determine atomic positions to <1 A resolution. In the case of samples with topographic features larger than atoms, the probe tip of the AFM 'convolutes' with the size and shape of surface features. This has hindered the use of AFM for molecular level structural determination of proteins at the liquid/solid interface. The work presented in this dissertation covers the development of the surface oriented molecular sizing (SOMS) technique which makes use of the angstrom height resolution of the AFM and a physically based mathematical framework for the analysis of the height distribution of adsorbed protein molecules. The surface adsorption and orientation (SAO) model is developed using statistical thermodynamics to model the expected height distributions for molecules adsorbed on a surface. The SOMS technique will be shown to be viable through studies of ferritin and concanavalin A (Con A) at the water/mica interface. Using this technique we are able to determine both the three-dimensional size and the oligomerization state of the adsorbed molecules. This technique will then be utilized for the examination of denaturation of Con A at the interface, by a number of mechanisms. Further, the structural and orientational changes in Con A as a function of pH will also be presented. The final chapter of this dissertation will present an extension of these studies to the deposition and structure of Con A thin films on mica.

Waner, Mark Joseph

183

FAS1005 : Introduction aux sciences humaines Automne 2013  

E-print Network

ses fictions. Freud et L'« humiliation » psychanalytique. Sigmund Freud, L'homme aux loups Recueil (l'humain et ses fictions) 7- 17 octobre : Freud et la Psychanalyse L'homme moderne comme la somme de

Parrott, Lael

184

RSISTIVIT LECTRIQUE DU BISMUTH IRRADI AUX NEUTRONS RAPIDES  

E-print Network

L-247 R?SISTIVIT? ?LECTRIQUE DU BISMUTH IRRADI? AUX NEUTRONS RAPIDES G. QUELARD Section d'Etude des Solides Irradiés, C.E.N., 92260 Fontenay-aux-Roses, France Résumé. 2014 Nous avons irradié du bismuth, à damage in bismuth, at 20 K has been studied by means of electrical resistivity. Results are independent

Paris-Sud XI, Université de

185

Situations de prcarit aux Antilles et en Guyane  

Microsoft Academic Search

[fre] Situations de prcarit aux Antilles et en Guyane . Le dsquilibre entre une croissance trs rapide de la population active, et des crations d'emploi insuffisantes explique la progression du chmage aux Antilles au cours des dix dernires annes. Ce dernier s'accompagne de l'apparition d'une frange de situations intermdiaires enre ch- mage et activit temps plein : emplois irrguliers

Alain Tranap

1992-01-01

186

FALLAIT-IL APPLIQUER LA TAXE CARBONE AUX CARBURANTS ROUTIERS ?  

E-print Network

FALLAIT-IL APPLIQUER LA TAXE CARBONE AUX CARBURANTS ROUTIERS ? Richard Darbéra Latts - CNRS Darbera frappe les carburant routiers en France et dans plusieurs pays d'Europe justifierait que ceux-ci soient appliquée aux carburants consommés par les ménages a un coût économique supérieur au bénéfice attendu en

Paris-Sud XI, Université de

187

Ultra-fast liquid chromatography with tandem mass spectrometry determination of ochratoxin A in traditional Chinese medicines based on vortex-assisted solid-liquid microextraction and aptamer-affinity column clean-up.  

PubMed

A rapid, selective, and sensitive ultra-fast liquid chromatography with tandem mass spectrometry method was developed for the determination of ochratoxin A in traditional Chinese medicines based on vortex-assisted solid-liquid microextraction and aptamer-affinity column clean-up. Through optimizing the sample pretreatment procedures and chromatographic conditions, good linearity (r(2) ? 0.9993), low limit of detection (0.5-0.8?g/kg), and satisfactory recovery (83.54-94.44%) expressed the good reliability and applicability of the established method in various traditional Chinese medicines. Moreover, the aptamer-affinity column, prepared in-house, showed an excellent feasibility owing to its specific identification of ochratoxin A in various kinds of selected traditional Chinese medicines. The maximum adsorption amount and applicability value were 188.96 10.56 ng and 72.3%, respectively. The matrix effects were effectively eliminated, especially for m/z 404.2?358.0 of ochratoxin A. The application of the developed method for screening the natural contamination levels of ochratoxin A in 25 random traditional Chinese medicines on the market in China indicated that only eight samples were contaminated with low levels below the legal limit (5.0?g/kg) set by the European Union. This study provided a preferred choice for the rapid and accurate monitoring of ochratoxin A in complex matrices. PMID:25195673

Yang, Xihui; Hu, Yichen; Kong, Weijun; Chu, Xianfeng; Yang, Meihua; Zhao, Ming; Ouyang, Zhen

2014-11-01

188

Comportement de fritts et de films d'oxyde de titane en prsence d'atmosphres gazeuses, hors quilibre thermodynamique, en rgime stationnaire; application aux capteurs rsistifs d'oxygne  

NASA Astrophysics Data System (ADS)

Oxygen resistive titanium dioxide sensors are useful to control combustion but their studies raise fundamental problems. The non-stoichiometry of titanium dioxide is studied in the 870-1 100 K temperature range by using, out of equilibrium, gas mixture flow of CO, CO2, O2 and Ar. The electrical resistance of sintered samples (dense or porous) or films is measured in steady-state conditions as a function of th gaz flow rate. The deviation to equilibrium increases with the flow rate. The sample resistance is a function of the flow rate, oxygen partial pressure, temperature and microstructure of the specimen. The sensitivity to oxygen is increased by fast oxygen diffusion through the bulk creating a potential barrier at the surface of the grains. Under oxidizing conditions at 870 K, a bulk mechanism determines the resistance variation which is proportional to P_{O_2}^{1/4}/P_{CO}^{1/2}. If reducing conditions are applied, in the same conditions of temperature, the oxide develops a bulk non-stoichiometry which is controlled by the redox couple CO/CO2 assuming thermodynamical equilibrium. However the large number of conducting electrons favors an oxygen chemisorption, creating potential barriers at the surface of the grains. Accordingly the film resistance is a P_{O_2}^{1/2} function. The surface potential and coverage rate are calculated through several theoretical models ; their comparison allows to conclude in a relatively slow diffusion of oxygen vacancies at 870 K. At 1 100 K, the gaz mixture is rather close to thermodynamical equilibrium : in oxidizing medium the sample is equilibrated with oxygen, under CO/CO2 reducing conditions film sensors are only sensitive to oxygen traces. La non-stchiomtrie de l'oxyde de titane est tudie, dans le domaine de temprature 870-1 100 K, en prsence d'atmosphres hors quilibre thermodynamique, composes de CO, CO2, O2, Ar. La rsistance lectrique de diffrentes structures massives, poreuses ou en couches est mesure, en rgime stationnaire, en fonction du dbit des gaz ; ces atmosphres sont d'autant plus loignes de l'quilibre que le dbit est lev. On montre que les variations de rsistance des chantillons, en fonction du dbit, dpendent du domaine de pression partielle d'oxygne, de la temprature et de la structure des chantillons. La sensibilit l'oxygne est accrue par un morphologie qui, l'chelle macroscopique, favorise la diffusion de l'oxygne et qui, l'chelle microscopique, permet la cration de barrire de potentiel aux joints de grains. En milieu oxydant, 870 K, un mcanisme de volume qui met en jeu la cintique des changes avec la phase gazeuse, dtermine une variation de rsistance en P_{O_2}^{1/4}/P_{CO}^{1/2}. En milieu rducteur, la mme temprature, la non-stchiomtrie en volume de l'oxyde est fixe par le couple redox CO/CO2 comme si l'atmosphre tait en quilibre thermodynamique. Mais l'abondance des lectrons de conduction, favorise la chimisorption de l'oxygne qui contrle la rsistance des couches selon une loi en P_{O_2}^{1/2} en crant des barrires de potentiel la surface des grains. Des modles, permettant le calcul du potentiel de surface ainsi que du taux de recouvrement, sont dvelopps ; la comparaison des modles indique une diffusion relativement lente des lacunes d'oxygne 870 K. A 1 100 K, l'atmosphre tend tre l'quilibre thermodynamique : i) en atmosphre oxydante, tous les capteurs sont en quilibre avec la pression partielle d'oxygne ; ii) en atmosphre rductrice, domine par le couple redox CO/CO2, seules les couches sont sensibles la prsence de traces d'oxygne.

Jerisian, R.; Gautron, J.; Loup, J. P.

1992-04-01

189

Focused ultrasound solid-liquid extraction for the determination of perfluorinated compounds in fish, vegetables and amended soil.  

PubMed

In the present work a method was developed for the determination of different perfluorinated compounds (PFCs), including three perfluorinated sulfonic acids (PFSAs), seven perfluorocarboxylic acids (PFCAs), three perfluorophosphonic acids (PFPAs) and perfluorooctanesulfonamide (PFOSA) in fish, vegetables and amended soil samples based on focused ultrasound solid-liquid extraction (FUSLE) followed by solid-phase extraction (SPE) clean-up and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Different variables affecting the chromatographic separation (column type and pH of the mobile phase), the electrospray ionization (capillary voltage, nebulizer pressure and drying gas flow) and mass spectrometric detection (fragmentor voltage and collision energy) were optimized in order to improve the sensitivity of the separation and detection steps. In the case of FUSLE variables such as the solvent type, the solvent volume, the extraction temperature, the sonication and extraction time and the percentage of applied irradiation power were studied. Under optimized conditions, sonication of 2.5min with pulse times on of 0.8s and pulse times off of 0.2s in 7mL of (9:1) acetonitrile (ACN): water mixture in duplicate guaranteed exhaustive extraction of the matrices analyzed. Due to the non-selective extraction using FUSLE, different SPE cartridges (200-mg Waters Oasis-HLB, 150-mg Waters Oasis-WAX and 150-mg Waters Oasis-MAX) were tested in terms of extraction efficiency and matrix effect both in the extraction and detection steps. Mix mode SPE using Waters Oasis-WAX provided the best extraction efficiencies with the lowest matrix effect. The final method was validated in terms of recovery at two fortification levels (in the 80-120% for most of the analytes and matrices), precision (relative standard deviation in the 2-15% range) and method detection limits (MDLs, 0.3-12.4ng/g for vegetables, 0.2-12.5ng/g for fish and 1-22ng/g for amended soil). Finally the method was applied for the determination of the 14 PFCs in different vegetables and fish samples from a local supermarket and in a soil amended with a compost from a local wastewater treatment plant (WWTP). PMID:24495790

Zabaleta, Itsaso; Bizkarguenaga, Ekhie; Iparragirre, Arantza; Navarro, Patricia; Prieto, Ailette; Fernndez, Luis ngel; Zuloaga, Olatz

2014-02-28

190

Soins Aux Brules Apres Un Accident Nucleaire  

PubMed Central

Summary Les lsions radiques sont dues le plus souvent des radio-isotopes utiliss dans lindustrie. Lexplosion dun racteur nuclaire, les armes nuclaires ou une attaque terroriste constituent un risque dafflux massif de victimes brles. Les radiations ionisantes occasionnent des brlures thermiques, des syndromes dirradiation aigu avec pancytopnie et des signes cutans retards. Aprs une priode de latence, des symptmes cutans apparaissent et leur profondeur est proportionnelle la dose reue. Les protocoles habituels de ranimation des brls sappliquent ici. Les soins aux irradis ncessitent aussi une mesure de lirradiation et une dcontamination par des personnels entrans. En cas de catastrophe nuclaire, la priorit est doptimiser les structures existantes et de prserver les moyens pour les patients ayant la plus forte probabilit de survie. Aprs un accident nuclaire isol, les difficults dans les centres de brls sont lvaluation de la profondeur et les techniques chirurgicales de couverture cutane. La prparation des moyens mdicaux et des centres de brls est ncessaire pour faire face la prise en charge de ces brlures diffrentes et complexes. PMID:21991218

Bargues, L.; Donat, N.; Jault, P.; Leclerc, T.

2010-01-01

191

Order of Three-Phase (Solid-Liquid-Gas) Contact Line Tension Probed by Simulation of Three-Phase Contact Line Expansion on Small Hydrophobic Spheres  

PubMed

Expansion of the three-phase (solid-liquid-gas) contact line on the surface of silanated glass spheres was experimentally studied by means of a CCD high-speed video technique. The dependence of the central angle (measured at the particle center) of the contact line on time was determined. This dependence was theoretically simulated. Results of this simulation show a strong effect of line tension on the kinetics of the three-phase contact expansion. Order of the line tension (&mgr;J/m) is the same as that determined by A. W. Neumann and co-workers for similar hydrophobic surfaces by means of different techniques. PMID:9073434

Nguyen; Stechemesser; Zobel; Schulze

1997-03-15

192

Investigating the influence of production conditions on the energy distribution between the solid, liquid and gaseous products of slow pyrolysis  

NASA Astrophysics Data System (ADS)

Slow pyrolysis is a well established technology for converting biomass into a more stable form of carbon (biochar) while also producing energy rich by-products of bio-oil and syngas. Biochar is the porous, carbonaceous material produced by thermo-chemical treatment of organic materials in an oxygen-limited environment. Biochar can be incorporated into soils to improve soil fertility, reduce greenhouse gas emissions as well as provide long term storage of carbon or alternatively it can also provide additional energy to a pyrolysis system through combustion. Biochar production conditions have a significant influence on the yield as well as physiochemical and functional properties of the final pyrolysis products, resulting in a selection process aimed towards either agricultural benefits and carbon mitigation or heat/energy generation. This work aimed to investigate the effect of temperature, residence time and gas flow rate on the product energy distribution as well as the physical, chemical and soil functional properties of biochar, in order to optimise conditions best suited to maximise both energy value and agronomic benefit. Biochar samples were produced from wood pellets (WP) and straw pellets (SP) at two temperatures (350 and 650oC), with three residence times (10, 20 and 40 minutes) and three carrier gas flow rates (0, 0.3 and 0.6 L min-1). The energy balance of the system was determined through the calorimetric analysis of biochar and bio-oil, while the higher heating value for the syngas was calculated from the gas composition measured via mass spectroscopy. Biochar was also analysed for the physiochemical properties of proximate analysis and ultimate analysis as well as the functional property of environmentally stable carbon (C) content. As expected the yield of biochar decreased with increasing temperature resulting in elevated yields of liquid and gas fractions. Increased temperature also resulted in higher values of fixed C, total C, stable C and calorific value due to the increased emission of volatiles. The higher heating value for the syngas was also shown to increase with temperature due to greater release of combustible gas species at higher temperatures. The impact of residence time and gas flow rate were not as clear as for temperature but still demonstrated decreasing biochar yields as the respective parameters were increased. However the greatest impact occurred at 350oC and diminished when temperature was increased to 650oC. An understanding of the influence that production conditions have on the long term stability of biochar as well as the energy content of the solid, liquid and gas fractions obtained from pyrolysis is critical towards the development of specifically engineered biochar to deliver a specific function be it for agricultural use, carbon storage, energy generation or combinations of the three.

Crombie, Kyle; Masek, Ondrej

2013-04-01

193

Hommage aux morts de la France combattante Pierre Brossolette Albert Hall, Londres, 18 juin 1943  

E-print Network

� Hommage aux morts de la France combattante � Pierre Brossolette Albert Hall, Londres, 18 juin Analyse En rendant un hommage passionn� aux morts de la France Combattante, le 18 juin 1943 � l juin, le fondateur de la France Libre d�pose une gerbe au monument aux morts de la Grande Guerre et

Paris-Sud XI, Université de

194

Finite element analysis of the effect of a non-planar solid-liquid interface on the lateral solute segregation during unidirectional solidification  

NASA Technical Reports Server (NTRS)

The effect of solid-liquid interface shape on lateral solute segregation during steady-state unidirectional solidification of a binary mixture is calculated under the assumption of no convection in the liquid. A finite element technique is employed to compute the concentration field in the liquid and the lateral segregation in the solid with a curved boundary between the liquid and solid phases. The computational model is constructed assuming knowledge of the solid-liquid interface shape; no attempt is made to relate this shape to the thermal field. The influence of interface curvature on the lateral compositional variation is investigated over a range of system parameters including diffusivity, growth speed, distribution coefficient, and geometric factors of the system. In the limiting case of a slightly nonplanar interface, numerical results from the finite element technique are in good agreement with the analytical solutions of Coriell and Sekerka obtained by using linear theory. For the general case of highly non-planar interface shapes, the linear theory fails and the concentration field in the liquid as well as the lateral solute segregation in the solid can be calculated by using the finite element method.

Carlson, F. M.; Chin, L.-Y.; Fripp, A. L.; Crouch, R. K.

1982-01-01

195

Esterification of sodium 4-hydroxybenzoate by ultrasound-assisted solid-liquid phase-transfer catalysis using dual-site phase-transfer catalyst.  

PubMed

The catalytic esterification of sodium 4-hydroxybenzoate with benzyl bromide by ultrasound-assisted solid-liquid phase-transfer catalysis (U-SLPTC) was investigated using the novel dual-site phase-transfer catalyst 4,4'-bis(tributylammoniomethyl)-1,1'-biphenyl dichloride (BTBAMBC), which was synthesized from the reaction of 4,4'-bis(chloromethyl)-1,1'-biphenyl and tributylamine. Without catalyst and in the absence of water, the product yield at 60 C was only 0.36% in 30 min of reaction even under ultrasound irradiation (28 kHz/300 W) and 250 rpm of stirring speed. When 1cm(3) of water and 0.5 mmol of BTBAMBC were added, the yield increased to 84.3%. The catalytic intermediate 4,4'-bis(tributylammoniomethyl)-1,1'-biphenyl di-4-hydroxybenzoate was also synthesized to verify the intrinsic reaction which was mainly conducted in the quasi-aqueous phase locating between solid and organic phases. Pseudo-first-order kinetic equation was used to correlate the overall reaction, and the apparent rate coefficient with ultrasound (28 kHz/300 W) was 0.1057 min(-1), with 88% higher than that (0.0563 min(-1)) without ultrasound. The esterification under ultrasonic irradiation using BTBAMBC by solid-liquid phase-transfer catalysis was developed. PMID:23972326

Yang, Hung-Ming; Chu, Wei-Ming

2014-01-01

196

Effects of tilting mirrors on the solid-liquid interface during floating zone growth using tilting-mirror-type infrared-heating image furnace  

NASA Astrophysics Data System (ADS)

The effects of tilting the mirrors of a tilting-mirror-type image furnace were examined for the crystal growth of rutile by the infrared-heating floating zone (FZ) method. The mirrors were tilted from horizontal to 20 in 5 steps to examine the change of the solid-liquid interface during crystal growth. The molten zone was quenched during the FZ growth. A small amount of yttrium with an extremely small segregation coefficient was added to the molten zone so that the shape of the solid-liquid interface could be evaluated through the yttrium distribution. At zero degrees, the grown crystal side of the interface was highly convex with a convexity ( h/ r) of 0.55. The interface became less convex as the tilting angle increased. At the tilting angle of 20, it was still slightly convex with h/ r=0.20. On the other hand, the convexity of the interface on the feed side significantly decreased with increase in tilting angle; h/ r changed from 0.50 at 0 to 0.00 at 20, at which the interface was rather concave. A larger tilting angle stabilized the molten zone. Large rutile crystals of 18 mm diameter were successfully grown at a tilting angle of 10.

Abdur Razzaque Sarker, Md.; Watauchi, Satoshi; Nagao, Masanori; Watanabe, Takashi; Shindo, Isamu; Tanaka, Isao

2010-06-01

197

Determination of the Solid/Liquid Interface Shape and Resultant Radial Homogeneity in Directionally Solidified Hg(0.89)Mn(0.11)Te  

NASA Technical Reports Server (NTRS)

Directional solidification and interrupted directional solidification experiments were used to determine tile shape of the solid/liquid interface and the resultant radial homogeneity in Hg(0.89)Mg(0.11)Te. For directionally solidified samples solidified at a rate of 0.09 microns/sec in a thermal gradient of 83 C/cm, a maximum of 0.006 molar percent MnTe radial variation across the Hg0.89)Mn(0.11)Te boules at specific locations was determined using an FTIR technique. This FTIR evaluation of the radial homogeneity also indicated an asymmetrical, convex interface shape during solidification. The asymmetrical, convex shape of the growth interface was confirmed by interrupted directional solidification experiments. These were performed under the same growth conditions as the normally completed directional solidification experiments except that the samples were quenched before the final growth transient was reached. In these experiments, etching and scanning X-ray fluorescence were used to reveal the shape of the solid/liquid interface. Microprobe analysis of composition gradients across the interface was used to confirm the authors' previous work in evaluating the segregation coefficient of Hg(0.89)Mn(0.11)Te alloy. Microprobe analysis of the interface region of the interrupted growth sample revealed a dendritic structure containing secondary and tertiary dendritic arms.

Price, M. W.; Scripa, R. N.; Lehoczky, S. L.; Szofran, F. R.; Hanson, B.

1999-01-01

198

Solid-liquid hybrid assembly for ultrasonic elasticity measurements under hydrostatic conditions of up to 8 GPa in a Kawai-type multianvil apparatus  

NASA Astrophysics Data System (ADS)

A solid-liquid hybrid assembly has been designed for ultrasonic elasticity measurements of materials under hydrostatic conditions in a Kawai-type multianvil apparatus. In the assembly, a tungsten-carbide cubic anvil served as the buffer rod for the acoustic signals. The transducer and sample were mounted on two diagonally opposite truncated corners of the buffer-rod anvil. The sample was immersed in a liquid cell filled with a liquid pressure medium, a methanol-ethanol mixture (4:1 in volume), which produced hydrostatic conditions for the sample. The pressure was monitored with a bismuth pressure calibrant inside the liquid cell. Preliminary experiments using single-crystal MgO, polycrystal alumina, and silicate glass samples were successfully conducted up to 8GPa. This assembly is especially useful for precise elasticity measurements of single-crystal samples under hydrostatic compression.

Song, M.; Yoneda, A.; Ito, E.

2005-03-01

199

Determination of spinosad at trace levels in bee pollen and beeswax with solid-liquid extraction and LC-ESI-MS.  

PubMed

This paper reports the use of a new LC method with a fused-core analytical column coupled to ESI-MS to determine residues of the biopesticide spinosad in bee pollen and beeswax. The method analyzes the active ingredients, spinosyns A and D, with a simple and efficient sample treatment (recovery between 90 and 105%) consisting of a solid-liquid extraction with acetone (bee pollen) or acetonitrile (beeswax). The method was validated in terms of selectivity, LOD, LOQ, linearity, and precision. The LOD and LOQ values ranged between 0.1-0.2 and 0.4-0.7 ?g/kg, respectively. Moreover, the precision obtained within the linear concentration range (LOQ 500 ?g/kg) was satisfactory (RSD lower than 5%). Finally, the proposed method was applied to analyze bee pollen and beeswax samples collected from apiaries located close to fruit orchards in two Spanish regions. PMID:24243865

Yez, Karen P; Martn, Mara T; Bernal, Jos L; Nozal, Mara J; Bernal, Jos

2014-02-01

200

A multivalent hexapod: conformational dynamics of six-legged molecules in self-assembled monolayers at a solid-liquid interface.  

PubMed

A molecular hexapod having a benzene core and six oligo(p-phenylene vinylene) (OPV) legs is an ideal system to probe various types of (intramolecular) dynamics of individual molecules in physisorbed self-assembled monolayers at a solid-liquid interface. Scanning tunneling microscopy reveals that molecules adsorb in 2D crystalline as well as disordered domains. Strikingly, not all molecules have the six OPV units in contact with the graphite substrate: 4% of the molecules in the 2D crystalline domains and up to 80% of the molecules in the disordered domains have one or two OPV units desorbed. In addition, the presence of such a defect promotes the coexistence of another defect adjacent to it. Time-dependent STM experiments and molecular dynamics simulations reveal in detail the different dynamics involved and the multivalent nature of the interactions between hexapod and surface. PMID:19361208

Xu, Hong; Minoia, Andrea; Tomovi?, Zeljko; Lazzaroni, Roberto; Meijer, E W; Schenning, Albertus P H J; De Feyter, Steven

2009-04-28

201

Comparison Between 2 Methods of Solid-Liquid Extraction for the Production of Cinchona calisaya Elixir: An Experimental Kinetics and Numerical Modeling Approach.  

PubMed

The purpose of this study is to compare the extraction process for the production of China elixir starting from the same vegetable mixture, as performed by conventional maceration or a cyclically pressurized extraction process (rapid solid-liquid dynamic extraction) using the Naviglio Extractor. Dry residue was used as a marker for the kinetics of the extraction process because it was proportional to the amount of active principles extracted and, therefore, to their total concentration in the solution. UV spectra of the hydroalcoholic extracts allowed for the identification of the predominant chemical species in the extracts, while the organoleptic tests carried out on the final product provided an indication of the acceptance of the beverage and highlighted features that were not detectable by instrumental analytical techniques. In addition, a numerical simulation of the process has been performed, obtaining useful information about the timing of the process (time history) as well as its mathematical description. PMID:25154593

Naviglio, Daniele; Formato, Andrea; Gallo, Monica

2014-09-01

202

Latent Heat storage characteristics of solid-liquid phase change Heat Storage Microcapsule Slurry by Boiling Heat Transfer under a Vacuum Condition  

NASA Astrophysics Data System (ADS)

Recently, the new heat transfer medium, which fulfills both functions of heat storage and heat transportation, has been developed in ah eat storage field. Solid-liquid latent heat microcapsule slurry would correspond to the topical medium, so-called functionally thermal fluid. The preset study has clarified the latent heat storage characteristics of microcapsule slurry by making heat transfer enlargement with the help of slurry water pool boiling phenomenon. The paraffin wax at a melting point of 62C was used as a phase change material which was packed into the microcapsule. The heating surface temperature and concentration of paraffin in the microcapsule slurry was selected as experimental parameters. As a result, the non-dimensional correlation equations of heat storage completion time and heat transfer were derived in terms of non-dimensional parameters.

Inaba, Hideo; Horibe, Akihiko; Haruki, Naoto; Katayama, Masatoshi; Manabe, Ken

203

ANDR KASPI La peine de mort aux tats-Unis  

E-print Network

Lectures ANDR� KASPI La peine de mort aux �tats-Unis Paris, Plon, 2003, 250 pages. par Daniel aujourd'hui le maintien de la peine de mort, du moins au sein de l'ensemble des pays d�mocratiques. � son�ment contribuant � la fois � une d�responsabilisation g�n�ralis�e � l'�gard de la peine de mort et au renforcement

Boyer, Edmond

204

Bourses d'tudes aux 5 000 $ US par semestre  

E-print Network

Bourses d'études aux ?tats-Unis 5 000 $ US par semestre Allocation pour l'assurance médicale de 1er cycle à temps plein Le programme de bourses Killam www.killamfellowships.com Geneviève Boutin-Maison Boursier Killam 2013-2014 Université d'Ottawa #12;Un coup d'oeil sur la bourse LE PROGRAMME DE BOURSES

Petriu, Emil M.

205

Financer les bourses des tudiants Encourager la persvrance aux tudes  

E-print Network

Financer les bourses des étudiants Encourager la persévérance aux études Souligner l'?cole Portail de l'enseignement coopératif Portail du Fonds de développement Programme de bourses auprès des étudiants Remises de bourses du Fonds de développement de l'?cole ?crans en circuit fermé de l'?cole au

Québec, Université du

206

I -INTRODUCTION AUX STATISTIQUES J-P. Croisille  

E-print Network

I - INTRODUCTION AUX STATISTIQUES J-P. Croisille Universit´e de Lorraine UEL - Ann´ee 2012/2013 Jean-Pierre CROISILLE - Laboratoire LMAM UEL: L'influence des math´ematiques sur la soci´et´e #12´ees/multivari´ees Jean-Pierre CROISILLE - Laboratoire LMAM UEL: L'influence des math´ematiques sur la soci´et´e #12;Donn

Croisille, Jean-Pierre

207

Le concept de chmage involontaire : de Keynes aux nouveaux keynsiens  

Microsoft Academic Search

[fre] Le concept de chmage involontaire, de Keynes aux nouveaux keynsiens. . L' objectif de la prsente tude est de rflchir sur l'volution des ides quant l'acceptabilit du concept de chmage involontaire l'intrieur de la thorie noclassique. Dans une premire partie, je propose ma propre reconstruction du projet global mis en uvre par Keynes dans la Thorie gnrale.

Michel De Vroey

1997-01-01

208

valuation de la performance prquatrice des concours financiers de l'tat aux communes  

Microsoft Academic Search

[fre] valuation de la performance prquatrice des concours financiers de ltat aux communes . . Les 36 600 communes franaises sont loin de pouvoir offrir aux rsidents ou aux entreprises quelles accueillent le mme niveau de services collectifs de proximit pour un effort fiscal donn. Leurs pouvoirs dachat en termes de consommations collectives varient dans des proportions considrables. Dune part,

Guy Gilbert; Alain Guengant

2004-01-01

209

Low energy electron diffraction (LEED) and sum frequency generation (SFG) vibrational spectroscopy studies of solid-vacuum, solid-air and solid-liquid interfaces  

SciTech Connect

Electron based surface probing techniques can provide detailed information about surface structure or chemical composition in vacuum environments. The development of new surface techniques has made possible in situ molecular level studies of solid-gas interfaces and more recently, solid-liquid interfaces. The aim of this dissertation is two-fold. First, by using novel sample preparation, Low Energy Electron Diffraction (LEED) and other traditional ultra high vacuum (UHV) techniques are shown to provide new information on the insulator/vacuum interface. The surface structure of the classic insulator NaCl has been determined using these methods. Second, using sum frequency generation (SFG) surface specific vibrational spectroscopy studies were performed on both the biopolymer/air and electrode/electrolyte interfaces. The surface structure and composition of polyetherurethane-silicone copolymers were determined in air using SFG, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). SFG studies of the electrode (platinum, gold and copper)/electrolyte interface were performed as a function of applied potential in an electrochemical cell.

Hoffer, Saskia

2002-08-19

210

Phase relations in the system NaCl-KCl-H2O: V. Thermodynamic-PTX analysis of solid-liquid equilibria at high temperatures and pressures  

USGS Publications Warehouse

The Gibbs energies of mixing for NaCl-KCl binary solids and liquids and solid-saturated NaCl-KCl-H2O ternary liquids were modeled using asymmetric Margules treatments. The coefficients of the expressions were calibrated using an extensive array of binary solvus and solidus data, and both binary and ternary liquidus data. Over the PTX range considered, the system exhibits complete liquid miscibility among all three components and extensive solid solution along the anhydrous binary. Solid-liquid and solid-solid phase equilibria were calculated by using the resulting equations and invoking the equality of chemical potentials of NaCl and KCl between appropriate phases at equilibrium. The equations reproduce the ternary liquidus and predict activity coefficients for NaCl and KCl components in the aqueous liquid under solid-saturation conditions between 673 and 1200 K from vapor saturation up to 5 kbar. In the NaCl-KCl anhydrous binary system, the equations describe phase equilibria and predict activity coefficients of the salt components for all stable compositions of solid and liquid phases between room temperature and 1200 K and from 1 bar to 5 kbar. ?? 1992.

Sterner, S.M.; Chou, I.-M.; Downs, R.T.; Pitzer, K.S.

1992-01-01

211

Numerical research on the effects of impeller pump-out vanes on axial force in a solid-liquid screw centrifugal pump  

NASA Astrophysics Data System (ADS)

A commercial CFD code has been used to predict the performance of a screw centrifugal pump with pump-out vanes, especially when changing regularity of impeller axial force based on the solid-liquid two-phase flow. The Unsteady Reynolds Averaged Navier-Stokes (URANS) approach has been applied to solve the unsteady, incompressible, three-dimensional turbulent. The SIMPLEC algorithm, standard wall functions and mix two-phase flow model were applied. The RNG k ?-model was used to account the turbulence effects. By changing the number of impeller pump-out vanes and width, six different screw centrifugal pump numerical simulation projects were given, and each scheme in the different solid volume fraction were calculated respectively. The change rules of axial force, velocity and pressure distribution of flow field were obtained on the different condition and different volume fraction. The results showed that the axial forces values based solid-fluid two-phase greater than based single-phase clear water, but both changing regularity of the axial force were consistent; as same condition, the same solid-phase volume concentration, with the increase of pump-out vanes number or width, the impeller axial force increased as well. Meanwhile the number of the pump-out vanes and the width of pump-out vanes in balancing the impeller axial force, there are the most optimal value.

Cheng, X. R.; Li, R. N.; Gao, Y.; Guo, W. L.

2013-12-01

212

Comparing the Catalytic Oxidation of Ethanol at the Solid-Gas and Solid-Liquid Interfaces over Size-Controlled Pt Nanoparticles: Striking Differences in Kinetics and Mechanism.  

PubMed

Pt nanoparticles with controlled size (2, 4, and 6 nm) are synthesized and tested in ethanol oxidation by molecular oxygen at 60 C to acetaldehyde and carbon dioxide both in the gas and liquid phases. The turnover frequency of the reaction is ?80 times faster, and the activation energy is ?5 times higher at the gas-solid interface compared to the liquid-solid interface. The catalytic activity is highly dependent on the size of the Pt nanoparticles; however, the selectivity is not size sensitive. Acetaldehyde is the main product in both media, while twice as much carbon dioxide was observed in the gas phase compared to the liquid phase. Added water boosts the reaction in the liquid phase; however, it acts as an inhibitor in the gas phase. The more water vapor was added, the more carbon dioxide was formed in the gas phase, while the selectivity was not affected by the concentration of the water in the liquid phase. The differences in the reaction kinetics of the solid-gas and solid-liquid interfaces can be attributed to the molecular orientation deviation of the ethanol molecules on the Pt surface in the gas and liquid phases as evidenced by sum frequency generation vibrational spectroscopy. PMID:25337984

Sapi, Andras; Liu, Fudong; Cai, Xiaojun; Thompson, Christopher M; Wang, Hailiang; An, Kwangjin; Krier, James M; Somorjai, Gabor A

2014-11-12

213

Controlled self-assembly and photovoltaic characteristics of porphyrin derivatives on a silicon surface at solid-liquid interfaces.  

PubMed

Two meso-tetraphenylporphyrin (H2TPP) derivatives with different central metal ions, namely ZnTPP, CuTPP, were synthesized, and characterized by a series of spectroscopic methods. Their self-assembly behaviors in mixed solvents without surfactant were systematically investigated. The morphology of the thus produced nanoarchitectures could be efficiently controlled. Nanoslices can be manufactured when a volume of cyclohexane is involved, octahedrons can be produced when a mixed solvent of chloroform and isopropanol is employed, while four-leaf clover-shaped structures can be produced with a large volume of methanol injected. The nanostructures have been characterized by electronic absorption, scanning electron microscopy (SEM) and photoelectric conversion techniques. The internal structures of the nanostructures are well described by XRD. The nanostructures exhibit a power conversion under illumination intensity of 2.3 mW cm(-2). The present result appears to represent an effort toward controlling the morphology of self-assembled nanostructures of porphyrin derivatives via synthesis through introduction of metal-ligand and solvent interaction. Nevertheless, the fundamental study will be helpful to understand photoinduced energy/charge transport in an organic interface and this might also serve as promising building blocks for nanoscale power sources for potential application in solar energy technologies and organic electronics and optoelectronics. PMID:24647426

Cai, Jinhua; Chen, Haihui; Huang, Jiangen; Wang, Jingxia; Tian, Dongliang; Dong, Huanli; Jiang, Lei

2014-04-21

214

Electrical resistance tomography for real-time mapping of the solid-liquid interface in tanks containing optically opaque fluids  

NASA Astrophysics Data System (ADS)

The visualization of settled solid layers in vessels have many applications, of interest here is for facilitating the efficient retrieval of high-level radioactive waste (HLW) from underground storage tanks at Department of Energy sites. Visualization of the solids interface with opaque liquid above can"t be accomplished by regular optical imaging methods and hence our interest in using Electrical Resistance Tomography (ERT). The ideal arrangement for 3-D ERT imaging inside tanks is to use a multiple ring electrode system, which is complex and expensive. This research describes ERT imaging done with a single linear array as a benchmark study to ascertain the viability of its imaging of the interface. Experiments focused upon systematic analysis of many ERT tomograms of two simple settled solids layers (horizontal, 30o) using pulverized kaolin clay (10?dia) and water. Visualization was done using commercial ERT software. Injection current and electrode orientation were the two system parameters varied and analyzed. Reproducibility, accuracy and reliability of this ERT system will be presented.

Madupu, Amar; Mazumdar, Anindra; Zhang, Jinsong; Roelant, David; Srivastava, Rajiv

2005-03-01

215

ASSIMILATION DES EXPRIENCES DE HALL ET FARADAY AUX EFFETS DU GYROSCOPE;  

E-print Network

269 ASSIMILATION DES EXP?RIENCES DE HALL ET FARADAY AUX EFFETS DU GYROSCOPE; PAR 31. B. ?LIE. L élémentaires suivant O.x, c'est-à-dire perpendiculaires aux deux premières. Or le gyroscope présente le fait

Paris-Sud XI, Université de

216

VULNERABILITE TERRITORIALE ET RESILIENCES: RESISTANCES ET CAPACITES ADAPTATIVES FACE AUX ALEAS CLIMATIQUES  

E-print Network

1 VULNERABILITE TERRITORIALE ET RESILIENCES: RESISTANCES ET CAPACITES ADAPTATIVES FACE AUX ALEAS to formalize a paradigmatic change of natural risk treatment, namely applied to urban development strategies capacités adaptatives face aux aléas climatiques 1. INTRODUCTION Après la catastrophe provoquée par l

Boyer, Edmond

217

BEHAVIOR OF SURFACTANT MIXTURE AT SOLID/LIQUID AND OIL/LIQUID INTERFACE IN CHEMICAL FLOODING SYSTEMS  

SciTech Connect

The aim of the project is to develop and evaluate efficient novel surfactant mixtures for enhanced oil recovery. Preliminary ultra-filtration tests suggest that two kinds of micelles may exist in binary surfactant mixtures at different concentrations. Due to the important role played in interfacial processes by micelles as determined by their structures, focus of the current work is on the delineation of the relationship between such aggregate structures and chemical compositions of the surfactants. A novel analytical centrifuge application is explored to generate information on structures of different surfactants aggregates. In this report, optical systems, typical output of the analytical ultracentrifuge results and four basic experiments are discussed. Initial sedimentation velocity investigations were conducted using nonyl phenol ethoxylated decyl ether (NP-10) to choose the best analytical protocol, calculate the partial specific volume and obtain information on sedimentation coefficient, aggregation mass of micelles. The partial specific volume was calculated to be 0.920. Four softwares: Optima{trademark} XL-A/XL-I data analysis software, DCDT+, Svedberg and SEDFIT, were compared for the analysis of sedimentation velocity experimental data. The sedimentation coefficient and aggregation number of NP-10 micelles obtained using the first three softwares at 25 C are 209, 127, and 111, respectively. The last one is closest to the result from Light Scattering. The reason for the differences in numbers obtained using the three softwares is discussed. Based on these tests, Svedberg and SEDFIT analysis are chosen for further studies. This approach using the analytical ultracentrifugation offers an unprecedented opportunity now to obtain important information on mixed micelles and their role in interfacial processes.

Prof. P. Somasundaran

2002-03-01

218

BEHAVIOR OF SURFACTANT MIXTURES AT SOLID/LIQUID AND OIL/LIQUID INTERFACES IN CHEMICAL FLOODING SYSTEMS  

SciTech Connect

The aim of the project is to develop and evaluate efficient novel surfactant mixtures for enhanced oil recovery. Surfactant loss by adsorption or precipitation depends to a great extent on the type of surfactant complexes and aggregates formed. Such information as well as techniques to generate the information is lacking currently particularly for surfactant mixtures and surfactant/polymer systems. A novel analytical centrifuge application is explored during the last period to generate information on structures-performance relationship for different surfactant aggregates in solution and, in turn, at interfaces. To use analytical untracentrifuge for surfactant mixtures, information on partial specific volumes of single surfactants and their mixtures is required. Towards this purpose, surface tension and density measurements were performed to determine critical micellar concentrations (cmc), partial specific volumes of n-dodecyl-{beta}-Dmaltoside (DM), nonyl phenol ethoxylated decyl ether (NP-10) and their 1:1 mixtures at 25 C. Durchschlag's theoretical calculation method was adopted to calculate the partial specific volumes. Effects of temperature and mixing, as well as methods used for estimation on micellization and partial specific volumes were studied during the current period. Surface tension results revealed no interaction between the two surfactants in mixed micelles. Partial specific volume measurements also indicated no interaction in mixed micelles. Maximum adsorption density, area per molecule and free energy of micellization were also calculated. Partial specific volumes were estimated by two experimental methods: d{sub {rho}}/dc and V{sub {sigma}}. The difference between the results of using the two methods is within 0.5% deviation. It was found that the partial specific volume is concentration dependent and sensitive to changes in temperature. The information generated in this study will be used for the study of surfactant aggregate mass distribution in mixed systems. Such information will in future be used to identify optimum surfactant.

Prof. P. Somasundaran

2002-09-30

219

Cons?quences comportementales de la violence faite aux enfants  

PubMed Central

Rsum Objectif Discuter des rpercussions de la violence sur le dveloppement comportemental durant lenfance, mettre en vidence certains signes comportementaux susceptibles dalerter les mdecins la prsence dune maltraitance continue dun enfant et explorer le rle prcis du mdecin de famille dans une telle situation clinique. Sources des donnes Une recension systmatique a servi examiner la recherche pertinente, les articles de rvision clinique et les sites web des organismes de protection de la jeunesse. Message principal Le comportement dun enfant est une manifestation extriorise de sa stabilit et de sa scurit intrieures. Cest une lentille au travers de laquelle le mdecin de famille peut observer le dveloppement de lenfant pendant toute sa vie. Tous les genres de violence sont dommageables pour les enfants, quelle soit physique, affective ou psychologique, et peuvent causer des problmes long terme dans le dveloppement du comportement et de la sant mentale. Les mdecins de famille doivent connatre les indices de maltraitance et de ngligence envers les enfants et tre aux aguets de ces derniers afin dentreprendre les interventions appropries et amliorer les rsultats pour ces enfants. Conclusion La violence faite aux enfants peut causer un dveloppement psychologique dsordonn et des problmes de comportement. Les mdecins de famille exercent un rle important dans la reconnaissance des signes comportementaux laissant prsager une maltraitance, ainsi que pour offrir de laide afin de protger les enfants.

Al Odhayani, Abdulaziz; Watson, William J.; Watson, Lindsay

2013-01-01

220

Exposition prcoce aux aliments et allergies alimentaires chez les enfants  

PubMed Central

Rsum Question Jtais sous limpression quon devrait viter de donner aux nourrissons des aliments potentiellement allergnes comme des noix, du lait de vache et des ufs pour prvenir le dveloppement de ractions allergiques. Quels conseils devrait-on donner aux parents concernant lintroduction des aliments durant la petite enfance et le dveloppement des allergies alimentaires? Rponse Il ny a pas de donnes probantes indiquant que retarder lintroduction daliments particuliers aprs lge de 6 mois aide prvenir les allergies. Une rcente dclaration de la Socit canadienne de pdiatrie ne recommande aucun dlai quant lintroduction daliments durant la petite enfance. De rcentes tudes de recherche semblent aussi faire valoir que lintroduction prcoce (entre 4 et 6 mois) daliments possiblement allergnes procure une forme de protection et contribue prvenir les allergies, mais il faudrait plus de recherche ce sujet.

Chin, Benetta; Chan, Edmond S.; Goldman, Ran D.

2014-01-01

221

Multi-component analysis of bile acids in natural Calculus bovis and its substitutes by ultrasound-assisted solid-liquid extraction and UPLC-ELSD.  

PubMed

An ultrasound-assisted solid-liquid extraction (USLE) coupled to ultra-performance liquid chromatography-evaporative light scattering detection (UPLC-ELSD) method has been developed for the simultaneous extraction and determination of six bile acids (BAs) in natural Calculus bovis and its substitutes, collected from different origins. The USLE conditions, UPLC chromatographic and ELSD conditions for BAs were optimized. Under optimum conditions, the six target analytes were efficiently extracted and baseline separated within 10 min. The limits of detection (LODs) and quantification (LOQs) for six BAs were less than 7 ng and 22 ng, respectively. Average recoveries were within the range of 98.8-100.7% with relative standard deviations (RSDs) <2% for the six analytes. This method, due to its convenience, high selectivity, fast analysis efficiency and good reproducibility can be employed for analyzing the content differences of six BAs in 40 batches of natural C. bovis and its existing substitutes. The differences of the content of each BA in natural C. bovis and its substitutes were significant, and the total contents of six BAs in 13 batches of natural C. bovis were in the range of 7.96-160.17 mg g(-1), in 20 natural C. bovis of 0-245.89 mg g(-1), in 2 artificial cultivated C. bovis of 178.48-194.22 mg g(-1), in 3 cultured C. bovis of 41.01-107.3 mg g(-1), and in 2 counterfeit C. bovis of 144.9-340.25 mg g(-1). The significant differences of multi-component contents reflected the various inherent qualities of these samples, so, the use of these substitutes as the replacers of natural source in clinic should be paid more attention. Some substitutes could not be used as the replacers. PMID:23099565

Kong, Wei-Jun; Xing, Xiao-Yan; Xiao, Xiao-He; Wang, Jia-Bo; Zhao, Yan-Ling; Yang, Mei-Hua

2012-12-21

222

Structural characterization of the phospholipid stabilizer layer at the solid-liquid interface of dispersed triglyceride nanocrystals with small-angle x-ray and neutron scattering  

NASA Astrophysics Data System (ADS)

Dispersions of crystalline nanoparticles with at least one sufficiently large unit cell dimension can give rise to Bragg reflections in the small-angle scattering range. If the nanocrystals possess only a small number of unit cells along these particular crystallographic directions, the corresponding Bragg reflections will be broadened. In a previous study of phospholipid stabilized dispersions of ?-tripalmitin platelets [Unruh, J. Appl. Crystallogr.JACGAR0021-889810.1107/S0021889807044378 40, 1008 (2007)], the x-ray powder pattern simulation analysis (XPPSA) was developed. The XPPSA method facilitates the interpretation of the rather complicated small-angle x-ray scattering (SAXS) curves of such dispersions of nanocrystals. The XPPSA method yields the distribution function of the platelet thicknesses and facilitates a structural characterization of the phospholipid stabilizer layer at the solid-liquid interface between the nanocrystals and the dispersion medium from the shape of the broadened 001 Bragg reflection. In this contribution an improved and extended version of the XPPSA method is presented. The SAXS and small-angle neutron scattering patterns of dilute phospholipid stabilized tripalmitin dispersions can be reproduced on the basis of a consistent simulation model for the particles and their phospholipid stabilizer layer on an absolute scale. The results indicate a surprisingly flat arrangement of the phospholipid molecules in the stabilizer layer with a total thickness of only 12 . The stabilizer layer can be modeled by an inner shell for the fatty acid chains and an outer shell including the head groups and additional water. The experiments support a dense packing of the phospholipid molecules on the nanocrystal surfaces rather than isolated phospholipid domains.

Schmiele, Martin; Schindler, Torben; Unruh, Tobias; Busch, Sebastian; Morhenn, Humphrey; Westermann, Martin; Steiniger, Frank; Radulescu, Aurel; Lindner, Peter; Schweins, Ralf; Boesecke, Peter

2013-06-01

223

Simultaneous multi-mycotoxin determination in nutmeg by ultrasound-assisted solid-liquid extraction and immunoaffinity column clean-up coupled with liquid chromatography and on-line post-column photochemical derivatization-fluorescence detection.  

PubMed

A simple and sensitive analytical method based on ultrasound-assisted solid-liquid extraction and immunoaffinity column clean-up coupled with high performance liquid chromatography and on-line post-column photochemical derivatization-fluorescence detection (USLE-IAC-HPLC-PCD-FLD) has been developed for simultaneous multi-mycotoxin determination of aflatoxins B1, B2, G1, G2 (AFB1, AFB2, AFG1, AFG2) and ochratoxin A (OTA) in 13 edible and medicinal nutmeg samples marketed in China. AFs and OTA were extracted from nutmeg samples by ultrasonication using a methanol?:?water (80?:?20, v/v) solution, followed by an IAC clean-up step. Different USL extraction conditions, pre-processing ways for nutmeg sample and clean-up columns for mycotoxins, as well as HPLC-PCD-FLD parameters (mobile phase, column temperature, elution procedure, excitation and emission wavelengths) were optimized. This method, which was appraised for analyzing nutmeg samples, showed satisfactory results with reference to limits of detection (LODs) (from 0.02 to 0.25 ?g kg(-1)), limits of quantification (LOQs) (from 0.06 to 0.8 ?g kg(-1)), linear ranges (up to 30 ng mL(-1) for AFB1, AFG1 and OTA and 9 ng mL(-1) for AFB2 and AFG2), intra- and inter-day variability (all <2%) and average recoveries (from 79.6 to 90.8% for AFs and from 93.6 to 97.3% for OTA, respectively). The results of the application of developed method in nutmeg samples have elucidated that four samples were detected with contamination of AFs and one with OTA. AFB1 was the most frequently found mycotoxin in 30.8% of nutmeg samples at contamination levels of 0.73-16.31 ?g kg(-1). At least two different mycotoxins were co-occurred in three samples, and three AFs were simultaneously detected in one sample. PMID:23486692

Kong, Wei-Jun; Liu, Shu-Yu; Qiu, Feng; Xiao, Xiao-He; Yang, Mei-Hua

2013-05-01

224

Preliminary paleogeographic reconstruction of the Illinois basin during deposition of the Mississippian Aux Vases Formation: Implications for hydrocarbon recovery  

SciTech Connect

Extensive outcrop investigation and selective subsurface study allow definition of Illinois basin paleogeography during deposition of the Mississippian (Valmeyeran-Meramecian) Aux Vases Formation. The results incorporate an integrated approach utilizing field observations and petrographic analysis, wireline logs, subsurface maps, and cores. The Aux Vases Formation depositional system has been determined to be composed of subtidal to intertidal facies. Depositional facies in outcrop are based on rock body geometries, sedimentary structure assemblages, paleocurrent analysis, paleontology of body and trace fossils, facies relationships, and petrography. Depositional facies determined from subsurface data are based on correlation of lithologic interpretations from wireline logs, sand body geometries form isopach maps, and petrography. Specific depositional facies observed in outcrop and core and inferred from wireline logs and isopach maps are offshore bars and tidal channel complexes, extensive subtidal to lower intertidal, ripple-laminated, fine-grained quartzose sandstone. Carbonate facies occur as subtidal grainstones at or near the base of a sequence, or as high energy deposits which have been tidally reworked. This depositional system produces reservoir heterogeneities that complicate efficient hydrocarbon recovery. This diverse facies architecture is modified by tectonic and diagenetic overprinting, further segregating potential producing zones. To significantly improve recovery efficiency, predictions regarding compartmentalization can be used prior to designing a drilling program, an infill drilling program, or an application of enhanced recovery techniques.

Cole, R.D. (Illinois State Geological Survey, Champaign (United States))

1991-03-01

225

Hormone de croissance placentaire. Signification par rapport aux hormones de croissance et  

E-print Network

Hormone de croissance placentaire. Signification par rapport aux hormones de croissance et. Placentalgrowth hormone. Significance relative to pituitary growth hormo- nes and placental lactogen hormone growth hormone (PGH). This entity, agonist of pituitary GH, appears responsible for the elevated IGFI

Boyer, Edmond

226

FICHE DE RESULTATS Elections aux Commissions de Gestion de la Recherche  

E-print Network

-Luc LANGLOIS Michel HERNANDEZ Fabrice MORAND Pierre BRICQUET Jean-Pierre #12;FICHE DE RESULTATS Elections aux VIALA Anne Lise DARGOUGE Olivier GUILLAUME-SIGNORET Marie JEANNY Brigitte MUTHER Nadine ARCHAMBEAU Anne

227

Genome-wide analysis of Aux\\/IAA and ARF gene families in Populus trichocarpa  

Microsoft Academic Search

BACKGROUND: Auxin\\/Indole-3-Acetic Acid (Aux\\/IAA) and Auxin Response Factor (ARF) transcription factors are key regulators of auxin responses in plants. We identified the suites of genes in the two gene families in Populus and performed comparative genomic analysis with Arabidopsis and rice. RESULTS: A total of 35 Aux\\/IAA and 39 ARF genes were identified in the Populus genome. Comparative phylogenetic analysis

Udaya C Kalluri; Stephen P DiFazio; Amy M Brunner; Gerald A Tuskan

2007-01-01

228

Arabidopsis AUX1 Gene: A Permease-Like Regulator of Root Gravitropism  

Microsoft Academic Search

The plant hormone auxin regulates various developmental processes including root formation, vascular development, and gravitropism. Mutations within the AUX1 gene confer an auxin-resistant root growth phenotype and abolish root gravitropic curvature. Polypeptide sequence similarity to amino acid permeases suggests that AUX1 mediates the transport of an amino acid-like signaling molecule. Indole-3-acetic acid, the major form of auxin in higher plants,

Malcolm J. Bennett; Alan Marchant; Haydn G. Green; Sean T. May; Sally P. Ward; Paul A. Millner; Amanda R. Walker; Burkhard Schulz; Kenneth A. Feldmann

1996-01-01

229

Arabidopsis aux1rcr1 mutation alters AUXIN RESISTANT1 targeting and prevents expression of the auxin reporter DR5:GUS in the root apex.  

PubMed

Multilevel interactions of the plant hormones ethylene and auxin coordinately and synergistically regulate many aspects of plant growth and development. This study isolated the AUXIN RESISTANT1 (AUX1) allele aux1(rcr1) (RCR1 for REVERSING CTR1-10 ROOT1) that suppressed the root growth inhibition conferred by the constitutive ethylene-response constitutive triple response1-10 (ctr1-10) allele. The aux1(rcr1) mutation resulted from an L126F substitution at loop 2 of the plasma membrane-associated auxin influx carrier protein AUX1. aux1(rcr1) and the T-DNA insertion mutant aux1-T were both defective in auxin transport and many aspects of the auxin response. Unexpectedly, expression of the auxin-response reporter DR5:GUS in the root apex was substantially prevented by the aux1(rcr1) but not the aux1-T mutation, even in the presence of the wild-type AUX1 allele. Following treatment with the synthetic auxin 1-naphthaleneacetic acid (NAA), DR5:GUS expression in aux1(rcr1) and aux1-T occurred mainly in the root apex and mature zone. NAA-induced DR5:GUS expression in the root apex was markedly prevented by ethylene in genotypes with aux1(rcr1) but not in aux1-T genotypes and the wild type. The effect of aux1(rcr1) on DR5:GUS expression seemed to be associated with AUX1-expressing domains. Green fluorescence protein-fused aux1(rcr1) was localized in the cytoplasm and probably not to the plasma membrane, indicating important roles of the Lys(126) residue at loop 2 in AUX1 targeting. The possible effects of aux1(rcr1) on DR5:GUS expression are discussed. PMID:23293348

Yu, Jing; Wen, Chi-Kuang

2013-02-01

230

Application of a new Raman microprobe spectrometer to nondestructive analysis of sulfate and other ions in individual phases in fluid inclusions in minerals  

Microsoft Academic Search

et al . (1975), reported the first successful application of laser-excited Raman spectroscopy for the identification and nondestructive partial analysis of individual solid, liquid, and gaseous phases in selected fluid inclusions. We report here the results of the application of a new instrument, based on back-scattering, that eliminates many of the previous stringent sample limitations and hence greatly expands the

Gregory J. Rosasco; Edwin Roedder

1979-01-01

231

CIEAEM 57 Italie Italy Foire aux ides, Session de Poster Piazza Armerina, Forum of Ideas, Poster Session  

E-print Network

CIEAEM 57 ­ Italie ­ Italy Foire aux idées, Session de Poster Piazza Armerina, Forum of Ideas and in higher grades in the mathematical language of functions). #12;CIEAEM 57 ­ Italie ­ Italy Foire aux idées

Spagnolo, Filippo

232

Evidence supporting an intentional Neandertal burial at La Chapelle-aux-Saints  

PubMed Central

The bouffia Bonneval at La Chapelle-aux-Saints is well known for the discovery of the first secure Neandertal burial in the early 20th century. However, the intentionality of the burial remains an issue of some debate. Here, we present the results of a 12-y fieldwork project, along with a taphonomic analysis of the human remains, designed to assess the funerary context of the La Chapelle-aux-Saints Neandertal. We have established the anthropogenic nature of the burial pit and underlined the taphonomic evidence of a rapid burial of the body. These multiple lines of evidence support the hypothesis of an intentional burial. Finally, the discovery of skeletal elements belonging to the original La Chapelle aux Saints 1 individual, two additional young individuals, and a second adult in the bouffia Bonneval highlights a more complex site-formation history than previously proposed. PMID:24344286

Rendu, William; Beauval, Cedric; Crevecoeur, Isabelle; Bayle, Priscilla; Balzeau, Antoine; Bismuth, Thierry; Bourguignon, Laurence; Delfour, Geraldine; Faivre, Jean-Philippe; Lacrampe-Cuyaubere, Francois; Tavormina, Carlotta; Todisco, Dominique; Turq, Alain; Maureille, Bruno

2014-01-01

233

Evidence supporting an intentional Neandertal burial at La Chapelle-aux-Saints.  

PubMed

The bouffia Bonneval at La Chapelle-aux-Saints is well known for the discovery of the first secure Neandertal burial in the early 20th century. However, the intentionality of the burial remains an issue of some debate. Here, we present the results of a 12-y fieldwork project, along with a taphonomic analysis of the human remains, designed to assess the funerary context of the La Chapelle-aux-Saints Neandertal. We have established the anthropogenic nature of the burial pit and underlined the taphonomic evidence of a rapid burial of the body. These multiple lines of evidence support the hypothesis of an intentional burial. Finally, the discovery of skeletal elements belonging to the original La Chapelle aux Saints 1 individual, two additional young individuals, and a second adult in the bouffia Bonneval highlights a more complex site-formation history than previously proposed. PMID:24344286

Rendu, William; Beauval, Cdric; Crevecoeur, Isabelle; Bayle, Priscilla; Balzeau, Antoine; Bismuth, Thierry; Bourguignon, Laurence; Delfour, Graldine; Faivre, Jean-Philippe; Lacrampe-Cuyaubre, Franois; Tavormina, Carlotta; Todisco, Dominique; Turq, Alain; Maureille, Bruno

2014-01-01

234

Structural characterization of the voltage sensor domain and voltage-gated K+- channel proteins vectorially-oriented within a single bilayer membrane at the solid/vapor and solid/liquid interfaces via neutron interferometry  

PubMed Central

The voltage-sensor domain (VSD) is a modular 4-helix bundle component that confers voltage sensitivity to voltage-gated cation channels in biological membranes. Despite extensive biophysical studies and the recent availability of x-ray crystal structures for a few voltage-gated potassium (Kv-) channels and a voltage-gate sodium (Nav-) channel, a complete understanding of the cooperative mechanism of electromechanical coupling, interconverting the closed-to-open states (i.e. non-conducting to cation conducting) remains undetermined. Moreover, the function of these domains is highly dependent on the physical-chemical properties of the surrounding lipid membrane environment. The basis for this work was provided by a recent structural study of the VSD from a prokaryotic Kv-channel vectorially-oriented within a single phospholipid (POPC; 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) membrane investigated by x-ray interferometry at the solid/moist He (or solid/vapor) and solid/liquid interfaces thus achieving partial to full hydration, respectively (Gupta et. al. Phys. Rev E. 2011, 84). Here, we utilize neutron interferometry to characterize this system in substantially greater structural detail at the sub-molecular level, due to its inherent advantages arising from solvent contrast variation coupled with the deuteration of selected sub-molecular membrane components, especially important for the membrane at the solid/liquid interface. We demonstrate the unique vectorial orientation of the VSD and the retention of its molecular conformation manifest in the asymmetric profile structure of the protein within the profile structure of this single bilayer membrane system. We definitively characterize the asymmetric phospholipid bilayer solvating the lateral surfaces of the VSD protein within the membrane. The profile structures of both the VSD protein and phospholipid bilayer depend upon the hydration state of the membrane. We also determine the distribution of water and exchangeable hydrogen throughout the profile structure of both the VSD itself and the VSD:POPC membrane. These two experimentally-determined water and exchangeable hydrogen distribution profiles are in good agreement with molecular dynamics simulations of the VSD protein vectorially-oriented within a fully hydrated POPC bilayer membrane, supporting the existence of the VSDs water pore. This approach was extended to the full-length Kv-channel (KvAP) at solid/liquid interface, providing the separate profile structures of the KvAP protein and the POPC bilayer within the reconstituted KvAP:POPC membrane. PMID:22686684

Gupta, S.; Dura, J.A.; Freites, J.A.; Tobias, D.J.; Blasie, J. K.

2012-01-01

235

Mecanismos de Acci³n de las Auxinas y los Herbicidas Aux­nicos  

NSDL National Science Digital Library

Se muestra como las auxinas y los herbicidas aux­nicos pueden inducir respuestas celulares y se describe el transporte bas­peto de las auxinas. Tambi©n se muestra como los receptores de auxinas reconocen las auxinas y los herbicidas aux­nicos, los cuales inducen entonces la transmisi³n y traducci³n de se±ales para activar varios genes; el papel de los productos de esos genes en las respuestas de las plantas es tambi©n mostrado.

236

Coring Performance to Characterise the Geology in the ``Cran aux Iguanodons'' of Bernissart (Belgium)  

Microsoft Academic Search

The Cran aux iguanodons of Bernissart is a sinkhole (or chimney caving) with a valuable paleontological deposit due to the exceptional quantity and diversity of fossils found during the excavation conducted from 1878 to 1881. In fact, bones have been discovered in a clayey geological formation when digging mine gallery at the -322 m level. A subsequent extraction gave

Jean-Pierre Tshibangu; Fabrice Dagrain; Hughes Legrain; Benot Deschamps

2004-01-01

237

Attachement des Cilis du caecum de Cheval aux fragments vgtaux. Dgradation des chloroplastes.  

E-print Network

chloroplastes. Attachement des bactéries aux Ciliés du caecum. Annie BONHOMME-FLORENTIN LA G!40138, CNRS tissues, chloroplast degradation, and attachment of bacteria to the cecum. Cecum microfauna association. The morphology of ingested envacuolized chloroplasts changed rapidly, showing different stages of digestion

Boyer, Edmond

238

Observation de chloroplastes rsistants aux triazines chez une panicode, Setaria viridis L.  

E-print Network

Observation de chloroplastes résistants aux triazines chez une panicoïdée, Setaria viridis L individus d'une population jamais traitée mais possèdent des chloroplastes résistants : cette résistance est'autres types de résistance. SUMMARY Weeds, Setaria viridis L., Chloroplastic resistance, Triazines resistance

Paris-Sud XI, Université de

239

Financiarisation, Evaluation et Information Comptable : De la cration de valeur aux IFRS  

E-print Network

1 Financiarisation, Evaluation et Information Comptable : De la création de valeur aux IFRS Journée Concurrence marty@gredeg.cnrs.fr Mots clés : Financiarisation, création de valeur actionnariale, EVA, normes comptables et cours de bourse). Watts et Zimmerman développèrent, dans deux articles respectivement publiés

Paris-Sud XI, Université de

240

D'UNE AFFAIRE AUX AUTRES1 Josquin DEBAZ et Sophie ROUX2  

E-print Network

D'UNE AFFAIRE AUX AUTRES1 Josquin DEBAZ et Sophie ROUX2 QUELLE AFFAIRE ? Une introduction. Mais ce qui tint lieu d'introduction dans bien des articles, ce fut le récit en trois temps que les Jeanneret, La Querelle, chap. 1. 4 Sokal, « Entrevista com Alan Sokal ». Epstein, « Postmodernism

Paris-Sud XI, Université de

241

Liaison spcifique du cortisol aux protines plasmatiques chez le Cobaye, de la naissance au sevrage  

E-print Network

Liaison spécifique du cortisol aux protéines plasmatiques chez le Cobaye, de la naissance au Aubière, France. Summary. Specific binding of cortisol to plasma protein in the guinea-pig from birth : - the concentration of plasma cortisol by competitive binding to protein ; - the association constant, Ka, and total

Boyer, Edmond

242

Comment amliorer l'accs des populations pastorales aux services sociaux de base et  

E-print Network

production animale. L'analphabétisme touche 100% des Regional edition West Africa No. 3 October 2012 Les'Est du Tchad. Photo: Mahamat Bechir West Africa Message aux décideurs · Au sahel, la malnutrition sévit

Richner, Heinz

243

Le Knowledge Management appliqu aux problmatiques de dveloppement Durable dans la Supply Chain  

E-print Network

Le Knowledge Management appliqué aux problématiques de développement Durable dans la Supply Chain, Knowledge Management, Supply Chain, Nonaka, Modèle SECI halshs-00534785,version1-10Nov2010 #12;2 The Knowledge Management applied to Sustainable Development Problems in the Supply Chain Abstract The concept

Paris-Sud XI, Université de

244

De la pornographie illgale aux sex-shops English : From illegal pornography to sex stores  

E-print Network

De la pornographie illégale aux sex-shops English : From illegal pornography to sex stores Baptiste://dx.doi.org/10.1016/j.annder.2012.09.004 Mots-clefs : pornographie, commerce, droit, histoire, sociologie Keywords : pornography, commerce, law, history, sociology Quel était l'état du commerce pornographique

Boyer, Edmond

245

L'ethnologue face aux racismes : l'exemple tsigane** Patrick Williams*  

E-print Network

L'ethnologue face aux racismes : l'exemple tsigane** Patrick Williams* Ayant fait depuis des restitution d'une totalité. Celle-ci interdit en effet l'anonymat qui, dans les sociétés modernes, sert de majoritaire. The ethnologist and racisms : the example of gipsies Victims of exclusion for centuries, gipsy

Paris-Sud XI, Université de

246

The Arabidopsis AUX1 gene: a model system to study mRNA processing in plants  

Microsoft Academic Search

It is advantageous for an organism to be able to remove aberrant mRNAs that have either been incorrectly transcribed or processed in order to prevent the accumulation of potentially harmful proteins. The selective degradation of nonsense containing transcripts has been described in yeast, Caenorhabiditis elegans and plants. The ease of identification of new mutant alleles in the AUX1 gene of

Alan Marchant; Malcolm J. Bennett

1998-01-01

247

LE VOYAGE AUX AMRIQUES ET LES REVUES SAVANTES FRANAISES AU XIXE  

E-print Network

LE VOYAGE AUX AM?RIQUES ET LES REVUES SAVANTES FRAN?AISES AU XIXE SI?CLE Mona HUERTA* Pouvait Nouveau Monde, mais c'est aussi s'attarder sur la question de la médiatisation de ces voyages au cours du scientifiques à travailler sur les terres américaines ; rappelons en particulier le voyage de Pierre Bourguer

Paris-Sud XI, Université de

248

The carrier AUXIN RESISTANT (AUX1) dominates auxin flux into Arabidopsis protoplasts.  

PubMed

The ability of the plant hormone auxin to enter a cell is critical to auxin transport and signaling. Auxin can cross the cell membrane by diffusion or via auxin-specific influx carriers. There is little knowledge of the magnitudes of these fluxes in plants. Radiolabeled auxin uptake was measured in protoplasts isolated from roots of Arabidopsis thaliana. This was done for the wild-type, under treatments with additional unlabeled auxin to saturate the influx carriers, and for the influx carrier mutant auxin resistant 1 (aux1). We also used flow cytometry to quantify the relative abundance of cells expressing AUX1-YFP in the assayed population. At pH 5.7, the majority of auxin influx into protoplasts - 75% - was mediated by the influx carrier AUX1. An additional 20% was mediated by other saturable carriers. The diffusive influx of auxin was essentially negligible at pH 5.7. The influx of auxin mediated by AUX1, expressed as a membrane permeability, was 1.50.3?ms(-1) . This value is comparable in magnitude to estimates of efflux permeability. Thus, auxin-transporting tissues can sustain relatively high auxin efflux and yet not become depleted of auxin. PMID:25039492

Rutschow, Heidi L; Baskin, Tobias I; Kramer, Eric M

2014-11-01

249

Etude comparative de rcepteurs aux strognes : Aspects molculaire et cellulaire de la rponse aux strognes et anti-strognes impliqus dans les causes et thrapies du cancer du sein.  

E-print Network

??Les strognes (E2), via le rcepteur aux strognes (ER), contrlent l'expression de nombreux gnes impliqus dans la croissance, la diffrenciation cellulaire et les fonctions reproductrices. (more)

Le Grand, Adlade

2009-01-01

250

Profile structures of the voltage-sensor domain and the voltage-gated K+-channel vectorially oriented in a single phospholipid bilayer membrane at the solid-vapor and solid-liquid interfaces determined by x-ray interferometry  

PubMed Central

One subunit of the prokaryotic voltage-gated potassium ion channel from Aeropyrum pernix (KvAP) is comprised of six transmembrane ? helices, of which S1S4 form the voltage-sensor domain (VSD) and S5 and S6 contribute to the pore domain (PD) of the functional homotetramer. However, the mechanism of electromechanical coupling interconverting the closed-to-open (i.e., nonconducting-to-K+-conducting) states remains undetermined. Here, we have vectorially oriented the detergent (OG)-solubilized VSD in single monolayers by two independent approaches, namely directed-assembly and self-assembly, to achieve a high in-plane density. Both utilize Ni coordination chemistry to tether the protein to an alkylated inorganic surface via its C-terminal His6 tag. Subsequently, the detergent is replaced by phospholipid (POPC) via exchange, intended to reconstitute a phospholipid bilayer environment for the protein. X-ray interferometry, in which interference with a multilayer reference structure is used to both enhance and phase the specular x-ray reflectivity from the tethered single membrane, was used to determine directly the electron density profile structures of the VSD protein solvated by detergent versus phospholipid, and with either a moist He (moderate hydration) or bulk aqueous buffer (high hydration) environment to preserve a native structure conformation. Difference electron density profiles, with respect to the multilayer substrate itself, for the VSD-OG monolayer and VSD-POPC membranes at both the solid-vapor and solid-liquid interfaces, reveal the profile structures of the VSD protein dominating these profiles and further indicate a successful reconstitution of a lipid bilayer environment. The self-assembly approach was similarly extended to the intact full-length KvAP channel for comparison. The spatial extent and asymmetry in the profile structures of both proteins confirm their unidirectional vectorial orientation within the reconstituted membrane and indicate retention of the proteins folded three-dimensional tertiary structure upon completion of membrane bilayer reconstitution. Moreover, the resulting high in-plane density of vectorially oriented protein within a fully hydrated single phospholipid bilayer membrane at the solid-liquid interface will enable investigation of their conformational states as a function of the transmembrane electric potential. PMID:22060407

Gupta, S.; Liu, J.; Strzalka, J.; Blasie, J. K.

2011-01-01

251

Christian Hottin Monuments aux morts dans l'enseignement suprieur -2006 Le flambeau du savoir et la flamme du souvenir  

E-print Network

1 Christian Hottin ­ Monuments aux morts dans l'enseignement supérieur - 2006 Le flambeau du savoir et la flamme du souvenir Monuments aux morts et culte des morts dans les établissements d morts, comme en témoigne le cénotaphe érigé en haut de l'avenue et évoqué par Jules Romains dans Les

Paris-Sud XI, Université de

252

Localization of the auxin permease AUX1 suggests two functionally distinct hormone transport pathways operate in the Arabidopsis root apex  

PubMed Central

Auxins represent an important class of plant hormone that regulate plant development. Plants use specialized carrier proteins to transport the auxin indole-3-acetic acid (IAA) to target tissues. To date, efflux carrier-mediated polar auxin transport has been assumed to represent the sole mode of long distance IAA movement. Localization of the auxin permease AUX1 in the Arabidopsis root apex has revealed a novel phloem-based IAA transport pathway. AUX1, asymmetrically localized to the plasma membrane of root protophloem cells, is proposed to promote the acropetal, post-phloem movement of auxin to the root apex. MS analysis shows that IAA accumulation in aux1 mutant root apices is impaired, consistent with an AUX1 phloem unloading function. AUX1 localization to columella and lateral root cap tissues of the Arabidopsis root apex reveals that the auxin permease regulates a second IAA transport pathway. Expression studies using an auxin-regulated reporter suggest that AUX1 is necessary for root gravitropism by facilitating basipetal auxin transport to distal elongation zone tissues. PMID:11641271

Swarup, Ranjan; Friml, Jiri; Marchant, Alan; Ljung, Karin; Sandberg, Goran; Palme, Klaus; Bennett, Malcolm

2001-01-01

253

A combinatorial TIR1/AFB-Aux/IAA co-receptor system for differential sensing of auxin  

PubMed Central

The plant hormone auxin regulates virtually every aspect of plant growth and development. Auxin acts by binding to the F-box protein TIR1 and promotes the degradation of the Aux/IAA transcriptional repressors. Here, we show that efficient auxin binding requires assembly of an auxin co-receptor complex consisting of TIR1 and an Aux/IAA protein. Heterologous experiments in yeast and quantitative IAA binding assays using purified proteins showed that different combinations of TIR1 and Aux/IAA proteins form co-receptor complexes with a wide range of auxin-binding affinities. Auxin affinity appears to be largely determined by the Aux/IAA. As there are 6 TIR1/AFBs and 29 Aux/IAA proteins in Arabidopsis thaliana, combinatorial interactions may result in many co-receptors with distinct auxin sensing properties. We also demonstrate that the AFB5-Aux/IAA co-receptor selectively binds the auxinic herbicide picloram. This co-receptor system broadens the effective concentration range of the hormone and may contribute to the complexity of auxin response. PMID:22466420

Villalobos, Luz Irina A. Calderon; Lee, Sarah; De Oliveira, Cesar; Ivetac, Anthony; Brandt, Wolfgang; Armitage, Lynne; Sheard, Laura B.; Tan, Xu; Parry, Geraint; Mao, Haibin; Zheng, Ning; Napier, Richard; Kepinski, Stefan; Estelle, Mark

2012-01-01

254

Separation-preconcentration of nickel and lead in food samples by a combination of solid-liquid-solid dispersive extraction using SiO2 nanoparticles, ionic liquid-based dispersive liquid-liquid micro-extraction.  

PubMed

A microextraction method for the determination of nickel and lead using solid-liquid-solid dispersive extraction followed by ionic liquid-based dispersive liquid-liquid microextraction (SLSDE-ILDLLME) was presented. It was applied to the extraction of nickel and lead from food samples. Ammonium pyrrolidine dithiocarbamate (APDC) as complexing agent, [C4MIM][PF6] as ionic liquid, SiO2 as nanoparticles and 2molL(-1) HNO3 as eluent were used. Several important parameters such as amount of IL, extraction time, pH and volume of the complexing agent were investigated. The quantitative recoveries were obtained at pH 7.0 for analytes. Under the optimum conditions, the limits of detection (LODs) calculated using 3(Sd)blank/m were 0.17 for Ni(II) and 0.79gL(-1) for Pb(II) for aqueous solutions with 125 enrichment factor (EF). The limit of detections of the analyte ions (3(Sd)blank/m) for solid samples were 0.09gg(-1) (Ni) and 0.40gg(-1) (Pb). The accuracy of the proposed method was confirmed by the analysis of standard reference material (1577c bovine liver) and spiked recovery test. The proposed method was applied to determine nickel and lead levels in chicken, fish and meat samples. PMID:25281115

Jalbani, Nusrat; Soylak, Mustafa

2015-01-01

255

Determination of perfluorinated alkyl acids in corn, popcorn and popcorn bags before and after cooking by focused ultrasound solid-liquid extraction, liquid chromatography and quadrupole-time of flight mass spectrometry.  

PubMed

An analytical method is proposed to determine ten perfluorinated alkyl acids (PFAAs) [nine perfluorocarboxylic acids (PFCAs) and perfluorooctane sulfonate (PFOS)] in corn, popcorn and microwave popcorn packaging by focused ultrasound solid-liquid extraction (FUSLE) and ultra high performance liquid chromatography (UHPLC) coupled to quadrupole-time of flight mass spectrometry (QTOF-MS/MS). Selected PFAAs were extracted efficiently in only one 10-s cycle by FUSLE, a simple, safe and inexpensive technique. The developed method was validated for microwave popcorn bags matrix as well as corn and popcorn matrices in terms of linearity, matrix effect error, detection and quantification limits, repeatability and recovery values. The method showed good accuracy with recovery values around 100% except for the lowest chain length PFAAs, satisfactory reproducibility with RSDs under 16%, and sensitivity with limits of detection in the order of hundreds picograms per gram of sample (between 0.2 and 0.7ng/g). This method was also applied to the analysis of six microwave popcorn bags and the popcorn inside before and after cooking. PFCAs contents between 3.50ng/g and 750ng/g were found in bags, being PFHxA (perfluorohexanoic acid) the most abundant of them. However, no PFAAs were detected either corn or popcorn, therefore no migration was assumed. PMID:24986069

Moreta, Cristina; Tena, Mara Teresa

2014-08-15

256

Solid-liquid two-phase partitioning bioreactors (TPPBs) operated with waste polymers. Case study: 2,4-dichlorophenol biodegradation with used automobile tires as the partitioning phase.  

PubMed

Used automobile tire pieces were tested for their suitability as the sequestering phase in a two-phase partitioning bioreactor to treat 2,4-dichlorophenol (DCP). Abiotic sorption tests and equilibrium partitioning tests confirmed that tire "crumble" possesses very favourable properties for this application with DCP diffusivity (4.8נ10(-8)cm(2)/s) and partition coefficient (31) values comparable to those of commercially available polymers. Biodegradation tests further validated the effectiveness of using waste tires to detoxify a DCP solution, and allow for enhanced biodegradation compared to conventional single-phase operation. These results establish the potential of using a low-cost waste material to assist in the bioremediation of a toxic aqueous contaminant. PMID:22829285

Tomei, M Concetta; Annesini, M Cristina; Daugulis, Andrew J

2012-11-01

257

Etude par microanalyse aux rayons X des migrations d'argent dans Ag2 Te  

E-print Network

551 Etude par microanalyse aux rayons X des migrations d'argent dans Ag2 Te J. C. Bernède et Y résultats confirment l'hypothèse d'une migration ionique introduite pour rendre compte de l'allure des carac. 2014 We apply high enough electric field in M-Ag2Te-M structures to obtain a definitive memorization

Boyer, Edmond

258

De La Violence Dans La Rage Aux Tripes De Mustapha Tlili  

Microsoft Academic Search

Cette thse prsente une analyse du thme de la violence dans le livre du Mustapha Tlili intitul La Rage aux tripes.\\u000aLes personnages de ce livre nous conduisent dans un univers de violence de la colonisation et de la dcolonisation, ainsi que les consquences douloureuses, rsultats d'une humiliation refoule.\\u000aNotre but est donc de relever les formes et les reprsentations

Callixte Kayiranga

2006-01-01

259

"A Better Sharing of Knowledge" Mission de la DIST aux Etats-unis  

E-print Network

mars au 4 avril 2014 #12;2 Ce rapport retrace successivement les objectifs de la Mission de la DIST, la#12;1 "A Better Sharing of Knowledge" Mission de la DIST aux Etats-unis New-York, Washington du 24 et accompagnés par le Bureau du CNRS pour l'Amérique du Nord: la Mission adresse ses vifs

Canet, Léonie

260

Near-death experiences (NDE) Expriences aux frontires de la mort  

E-print Network

Near-death experiences (NDE) Expériences aux frontières de la mort Expériences de mort imminente = Expériences de l'au-delà ? = Expériences de l'en-deçà ? #12;Sources d'informations sur l'au-delà 1. La mort 2 de l'au-delà #12;Mythologie égyptienne : Livre des morts Mythologie grecque : Platon (428

Halazonetis, Thanos

261

Charte pdagogique de l'ulB DPARTEMENT ENSEIGNEMENT -DEPARTEMENT DE SUPPORT AUX ACTIVITS ACADMIQUES  

E-print Network

Charte pédagogique de l'ulB D?PARTEMENT ENSEIGNEMENT - DEPARTEMENT DE SUPPORT AUX ACTIVIT?S ACAD?MIQUES Conseil d'administration du 18 juin 2012 #12;Charte pédagogique de l'ULB 2 Charte pédagogique de l'université (articles 1 à 3); 2. les 10 axes stratégiques pour l'ULB adoptés par le CA du 21 avril 2008 ; 3. la Charte

Cerf, Nicolas

262

Mesure de la digestibilit des fourrages destins aux chevaux par la technique des sacs de nylon  

E-print Network

Mesure de la digestibilité des fourrages destinés aux chevaux par la technique des sacs de nylon selle adultes et par la technique des sacs de nylon sur 2 poneys mâles, adultes, munis d'une canule heures selon la méthode de TILLEY et TERRY (1963), puis le sac est introduit dans le caecum pour une

Boyer, Edmond

263

Guide de l'tudiant pour effectuer une demande de bourse aux tudes suprieures Introduction  

E-print Network

Guide de l'étudiant pour effectuer une demande de bourse aux études supérieures Introduction Une demande de bourse gagnante requiert une bonne préparation et du temps*. La Faculté des études supérieures série de consultations auprès de membres des comités de sélection de bourses des grands organismes

Parrott, Lael

264

INVESTISSEMENTS FRANAIS AUX ETATS-UNIS, STRATGIES DE CROISSANCE EXTERNE ET RACTIONS DU MARCH BOURSIER  

Microsoft Academic Search

Rsum : l'objectif de cet article est d'valuer la raction des marchs boursiers suite l'annonce d'investissements directs par des entreprises franaises aux Etats-Unis. L'tude empirique se fonde sur une mthodologie d'tude d'vnements, destine mesurer les rendements anormaux moyens et les rendements anormaux moyens cumuls, sur les cotations la Bourse de Paris, associs l'annonce d'acquisitions de firmes

Pierre-Xavier MESCHI; Emmanuel METAIS

265

Bruno JUDIC Les origines du culte de saint Martin aux V et VI sicles  

E-print Network

1 Bruno JUDIC Les origines du culte de saint Martin aux Vè et VIè siècles "Foedula qui par la anciens témoignages d'un culte de saint Martin. Il faut comprendre que Foedula, une femme de la haute époque le culte des saints Gervais et Protais fut d'ailleurs diffusé en Gaule. Mais quand Foedula est

Paris-Sud XI, Université de

266

Questionnements gographiques sur les monuments aux morts : symboliques et territoires de la commmoration  

E-print Network

historique, pour la première fois un chancelier allemand, Mme Angela Merkel, s'est tenu aux côtés du Lumières, premiers penseurs de l'idée européenne. L'événement est de taille puisqu'il s'agit pour Angela Merkel, représentante de la Nation allemande (le symbole est fort pour un pays qui fut notre principal

Paris-Sud XI, Université de

267

Pourquoi trouver un marqueur atmosphrique d'exposition aux particules diesel ?  

E-print Network

Pourquoi trouver un marqueur atmosphérique d'exposition aux particules diesel ? Dominique LAFON rôle cancérigène possible des émissions diesel a suscité de nombreuses études depuis 20 ans. Nous avons sérieux ne nous permet d'incriminer plus les émissions des véhicules à moteur diesel que ceux à moteur

Boyer, Edmond

268

Aux sources de la civilisation : Les jeunes lites brsiliennes et le voyage en Europe dans la  

E-print Network

1 Aux sources de la civilisation : Les jeunes élites brésiliennes et le voyage en Europe dans la...) fait que le voyage de formation en Europe devient le passage obligé de tout jeune membre de l séjour que ces élites trouvent leur légitimité ; mais pour accéder à ce voyage, il faut être à même de

Paris-Sud XI, Université de

269

Gopolitiques de Brest 2010 Migrations forces et vulnrabilits diffrencies face aux  

E-print Network

ravagea Londres en 1666 ou du tremblement de terre de Lisbonne en 1755 ou encore du Dust 1 Cet article est Sellin et Linda Gardelle (Ed.) (2012) 137-156" #12;Géopolitiques de Brest 2010 2 bowl aux Etats Unis souligne François Gemenne « jusqu'à l'exode provoqué par l'ouragan Katrina en 2005, la migration du Dust

Paris-Sud XI, Université de

270

Developmental specificity of auxin response by pairs of ARF and Aux/IAA transcriptional regulators.  

PubMed

The plant hormone auxin elicits many specific context-dependent developmental responses. Auxin promotes degradation of Aux/IAA proteins that prevent transcription factors of the auxin response factor (ARF) family from regulating auxin-responsive target genes. Aux/IAAs and ARFs are represented by large gene families in Arabidopsis. Here we show that stabilization of BDL/IAA12 or its sister protein IAA13 prevents MP/ARF5-dependent embryonic root formation whereas stabilized SHY2/IAA3 interferes with seedling growth. Although both bdl and shy2-2 proteins inhibited MP/ARF5-dependent reporter gene activation, shy2-2 was much less efficient than bdl to interfere with embryonic root initiation when expressed from the BDL promoter. Similarly, MP was much more efficient than ARF16 in this process. When expressed from the SHY2 promoter, both shy2-2 and bdl inhibited cell elongation and auxin-induced gene expression in the seedling hypocotyl. By contrast, gravitropism and auxin-induced gene expression in the root, which were promoted by functionally redundant NPH4/ARF7 and ARF19 proteins, were inhibited by shy2-2, but not by bdl protein. Our results suggest that auxin signals are converted into specific responses by matching pairs of coexpressed ARF and Aux/IAA proteins. PMID:15889151

Weijers, Dolf; Benkova, Eva; Jger, Katja E; Schlereth, Alexandra; Hamann, Thorsten; Kientz, Marika; Wilmoth, Jill C; Reed, Jason W; Jrgens, Gerd

2005-05-18

271

Electronic and geometric structure of AuxCuy clusters studied by density functional theory  

NASA Astrophysics Data System (ADS)

We have determined the stable structures of AuCun, Au2Cun, Au3Cun and AuxCu8-x clusters. It has been observed that AuCun, Au2Cun and Au3Cun systems have two-dimensional (2D) structures up to six atoms and they become three-dimensional (3D) afterwards. AuxCu8-x clusters favor 3D structures till the Au7Cu1 cluster. We have found a lowest energy isomer of Au6Cu2 from the literature. Bond lengths, binding energies, density of states (DOS), highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps, ionization potential (IP) and electron affinity (EA) have been calculated for these structures using the first principles density functional theory (DFT) within the generalized gradient approximation (GGA) and the local density approximation (LDA). Generally, we have observed the overlap between s electrons of Cu and p electrons of Au near the Fermi level. Charge transfers are calculated by using the Lwdin analysis. It is observed that one Cu atom does not significantly modify the clusters which have more gold atoms. It is also seen that these clusters generally have nonmagnetic properties and results are consistent with the hybridization between s and d orbitals of Au in AuxCu8-x clusters.

Kadioglu, Y.; zengi Aktrk, O.; Tomak, M.

2014-01-01

272

Aux1p/Swa2p is required for cortical endoplasmic reticulum inheritance in Saccharomyces cerevisiae.  

PubMed

In the yeast Saccharomyces cerevisiae, the endoplasmic reticulum (ER) is found at the periphery of the cell and around the nucleus. The segregation of ER through the mother-bud neck may occur by more than one mechanism because perinuclear, but not peripheral ER, requires microtubules for this event. To identify genes whose products are required for cortical ER inheritance, we have used a Tn3-based transposon library to mutagenize cells expressing a green fluorescent protein-tagged ER marker protein (Hmg1p). This approach has revealed that AUX1/SWA2 plays a role in ER inheritance. The COOH terminus of Aux1p/Swa2p contains a J-domain that is highly related to the J-domain of auxilin, which stimulates the uncoating of clathrin-coated vesicles. Deletion of the J-domain of Aux1p/Swa2p leads to vacuole fragmentation and membrane accumulation but does not affect the migration of peripheral ER into daughter cells. These findings suggest that Aux1p/Swa2p may be a bifunctional protein with roles in membrane traffic and cortical ER inheritance. In support of this hypothesis, we find that Aux1p/Swa2p localizes to ER membranes. PMID:11553703

Du, Y; Pypaert, M; Novick, P; Ferro-Novick, S

2001-09-01

273

Aux1p/Swa2p Is Required for Cortical Endoplasmic Reticulum Inheritance in Saccharomyces cerevisiae  

PubMed Central

In the yeast Saccharomyces cerevisiae, the endoplasmic reticulum (ER) is found at the periphery of the cell and around the nucleus. The segregation of ER through the mother-bud neck may occur by more than one mechanism because perinuclear, but not peripheral ER, requires microtubules for this event. To identify genes whose products are required for cortical ER inheritance, we have used a Tn3-based transposon library to mutagenize cells expressing a green fluorescent protein-tagged ER marker protein (Hmg1p). This approach has revealed that AUX1/SWA2 plays a role in ER inheritance. The COOH terminus of Aux1p/Swa2p contains a J-domain that is highly related to the J-domain of auxilin, which stimulates the uncoating of clathrin-coated vesicles. Deletion of the J-domain of Aux1p/Swa2p leads to vacuole fragmentation and membrane accumulation but does not affect the migration of peripheral ER into daughter cells. These findings suggest that Aux1p/Swa2p may be a bifunctional protein with roles in membrane traffic and cortical ER inheritance. In support of this hypothesis, we find that Aux1p/Swa2p localizes to ER membranes. PMID:11553703

Du, Yunrui; Pypaert, Marc; Novick, Peter; Ferro-Novick, Susan

2001-01-01

274

Water as a solid, liquid, and gas  

NSDL National Science Digital Library

The representation is a set of 3 diagrams, with accompanying text explanations, showing the arrangement of water molecules in each of its three states of matter and an activity that uses BB's and petri dishes to create models of ice, liquid water, and water vapor.

275

Enzyme adsorption at solid-liquid interfaces  

Microsoft Academic Search

Enzymes are proteins with the capacity of catalysing various reactions. Nowadays two types of enzymes, proteases and lipases, are available for use in detergent formulations for household and industrial laundry washing. Proteases are capable of catalysing the hydrolysis of proteins while lipases enable the hydrolysis of glycerol esters, the main component in fats and non-mineral oils. In this study, two

S. Duinhoven

1992-01-01

276

Penny Perfect Properties (Solid-Liquid Interactions)  

NSDL National Science Digital Library

Students investigate the property dependence between liquid and solid interfaces and determine observable differences in how liquids react to different solid surfaces. They compare copper pennies and plastic "coins" as the two test surfaces. Using an eye dropper to deliver various fluids onto the surfaces, students determine the volume and mass of a liquid that can sit on the surface. They use rulers, scales, equations of volume and area, and other methods of approximation and observation, to make their own graphical interpretations of trends. They apply what they learned to design two super-surfaces (from provided surface treatment materials) that arecapable of holding the most liquid by volume and by mass. Cost of materials is a parameter in their design decisions.

CREAM GK-12 Program, Engineering Education Research Center, College of Engineering and Architecture,

277

Chemical composition and geologic history of saline waters in Aux Vases and Cypress Formations, Illinois Basin  

USGS Publications Warehouse

Seventy-six samples of formation waters were collected from oil wells producing from the Aux Vases or Cypress Formations in the Illinois Basin. Forty core samples of the reservoir rocks were also collected from the two formations. Analyses of the samples indicated that the total dissolved solids content (TDS) of the waters ranged from 43,300 to 151,400 mg/L, far exceeding the 35,400 mg/mL of TDS found in typical seawater. Cl-Br relations suggested that high salinities in the Aux Vases and Cypress formation waters resulted from the evaporation of original seawater and subsequent mixing of the evaporated seawater with concentrated halite solutions. Mixing with the halite solutions increased Na and Cl concentrations and diluted the concentration of other ions in the formation waters. The elemental concentrations were influenced further by diagenetic reactions with silicate and carbonate minerals. Diagenetic signatures revealed by fluid chemistry and rock mineralogy delineated the water-rock interactions that took place in the Aux Vases and Cypress sandstones. Dissolution of K-feldspar released K into the solution, leading to the formation of authigenic illite and mixed-layered illite/smectite. Some Mg was removed from the solution by the formation of authigenic chlorite and dolomite. Dolomitization, calcite recrystallization, and contribution from clay minerals raised Sr levels significantly in the formation waters. The trend of increasing TDS of the saline formation waters with depth can be explained with density stratification. But, it is difficult to explain the combination of the increasing TDS and increasing Ca/Na ratio with depth without invoking the controversial 'ion filtration' mechanism.

Demir, I.; Seyler, B.

1999-01-01

278

Auxin-nonresponsive grape Aux\\/IAA19 is a positive regulator of plant growth  

Microsoft Academic Search

We report the characterization of VvIAA19, an auxin\\/indole-3-acetic acid (Aux\\/IAA) protein, in grapevine (Vitis vinifera L.). VvIAA19 was expressed abundantly in berries. VvIAA19 transcription was rapidly increased at pre-anthesis and then decreased during fruit set. Before vraison, however, VvIAA19 gene expression was upregulated again and maximum expression was maintained until the end of ripening. Exogenous IAA did\\u000a not induce VvIAA19

Minako Kohno; Haruka Takato; Haruka Horiuchi; Keiko Fujita; Shunji Suzuki

279

Information destine aux tudiants des cycles suprieurs Page 1 sur 5  

E-print Network

'ouverture. #12;Information destinée aux étudiants des cycles supérieurs Page 3 sur 5 COURRIER Il est possible de recevoir du courrier au département. Un casier, qu'il vous faudra partager avec 2 ou 3 étudiants, est mis à-ville 2500, ch. de Polytechnique Campus de l'Université de Montréal Montréal (Québec) H3C 3A7 COURRIER

Meunier, Michel

280

Soins primaires aux adultes ayant une d?ficience d?veloppementale  

PubMed Central

Rsum Objectif Mettre jour les lignes directrices canadiennes de 2006 sur les soins primaires aux adultes ayant une dficience dveloppementale (DD) et prsenter des recommandations pratiques fondes sur les connaissances actuelles pour traiter des problmes de sant particuliers chez des adultes ayant une DD. Qualit des preuves Des professionnels de la sant expriments participant un colloque et un groupe de travail subsquent ont discut et convenu des rvisions aux lignes directrices de 2006 en se fondant sur une recherche documentaire exhaustive, la rtroaction obtenue des utilisateurs du guide de pratique et les expriences cliniques personnelles. La plupart des preuves disponibles dans ce domaine viennent de lopinion dexperts ou de dclarations consensuelles publies (niveau III). Message principal Les adultes ayant une DD ont des problmes de sant complexes, dont plusieurs diffrent de ceux de la population en gnral. De bons soins primaires permettent didentifier les problmes de sant particuliers dont souffrent les adultes ayant une DD pour amliorer leur qualit de vie et leur accs aux soins de sant et prvenir la morbidit et le dcs prmatur. Ces lignes directrices rsument les problmes de sant gnrale, physique, comportementale et mentale des adultes ayant une DD que devraient connatre les professionnels des soins primaires et prsentent des recommandations pour le dpistage et la prise en charge en se basant sur les connaissances actuelles que les cliniciens peuvent mettre en pratique. En raison de linteraction des facteurs biologiques, psychoaffectifs et sociaux qui contribuent la sant et au bien-tre des adultes ayant une DD, ces lignes directrices insistent sur la participation des aidants, ladaptation des interventions, au besoin, et la consultation auprs de divers professionnels de la sant quand ils sont accessibles. Elles mettent aussi en vidence la nature thique des soins. Les lignes directrices sont formules dans le contexte dun cadre thique qui tient compte des questions comme le consentement clair et lvaluation des bienfaits pour la sant par rapport aux risques de prjudice. Conclusion La mise en uvre des lignes directrices proposes ici amliorerait la sant des adultes ayant une DD et minimiserait les disparits sur les plans de la sant et des soins de sant entre les adultes ayant une DD et la population en gnral.

Sullivan, William F.; Berg, Joseph M.; Bradley, Elspeth; Cheetham, Tom; Denton, Richard; Heng, John; Hennen, Brian; Joyce, David; Kelly, Maureen; Korossy, Marika; Lunsky, Yona; McMillan, Shirley

2011-01-01

281

Bourses pour stagiaires trangers aux cycles suprieurs (sjours de 4 6 mois l'Universit Laval)  

E-print Network

Bourses pour stagiaires étrangers aux cycles supérieurs (séjours de 4 à 6 mois à l'Université Laval quatre à six mois à l'aide d'un programme de bourses du Ministère des affaires étrangères et du commerce de plus de 400,000$ en bourses versées. De ce nombre, plusieurs ont décidé de poursuivre des études à

Laval, Université

282

Aperu phytosociologique sur les pturages naturels aux environs de castelo de vide  

Microsoft Academic Search

Rsum頠Etudiant les jachres ptures de la zone de culture du seigle, aux environs de Castelo de Vide, l'auteur dfinit une association\\u000a nouvelle le Lupineto-Astrocarpetum purpurascentis appartenant l'Helianthemion guttati Br.-Bl. (1931) 1940 em.\\u000a \\u000a Cette association occupe les sols siliceux, nettement acides, frais pendant l'hiver et une partie du printemps. Elle prsente\\u000a un caractre floristique mditerranen trs net, tout

J. Malato-Beliz

1954-01-01

283

PROPRITS DILECTRIQUES DE L'OXYDE CUIVREUX AUX AUDIOFRQUENCES ENTRE 150 K ET 320 K  

E-print Network

393 PROPRI?T?S DI?LECTRIQUES DE L'OXYDE CUIVREUX AUX AUDIOFR?QUENCES ENTRE 150 °K ET 320 °K par C échantillons ont été obtenus par oxydation du cuivre à 1 O50 °C et recuit à 1 100 °C en présence d'air sous pression atmosphérique. Le montage utilisé est semblable à celui décrit par Grun [5]. Les durées d'oxydation

Boyer, Edmond

284

Contr^ole des equations aux derivees partielles aspects theorique et  

E-print Network

Contr^ole des ´equations aux d´eriv´ees partielles ­ aspects th´eorique et num´erique J´er^ome LE ROUSSEAU F´ed´eration Denis-Poisson, MAPMO, Universit´e d'Orl´eans Journ´ee contr^ole du Pole 3 ­ Universit´e d'Orl´eans 1/ 24 J. Le Rousseau Contr^ole des EDP #12;Contr^ole en dimension finie Syst`eme contr

d'Orléans, Université

285

dition interactive d'noncs en langue des signes franaise ddie aux avatars signeurs  

E-print Network

?dition interactive d'énoncés en langue des signes française dédiée aux avatars signeurs Ludovic a été publié dans les actes de la Conférence TALN-RECITAL 2013 R?SUM? Les avatars signeurs en Langue des de la communauté sourde. L'un des critères d'acceptation de ces avatars est l'aspect naturel et

Paris-Sud XI, Université de

286

The AUX1 LAX family of auxin influx carriers is required for the establishment of embryonic root cell organization in Arabidopsis thaliana  

PubMed Central

Background and Aims The root meristem of the Arabidopsis thaliana mature embryo is a highly organized structure in which individual cell shape and size must be regulated in co-ordination with the surrounding cells. The objective of this study was to determine the role of the AUX1 LAX family of auxin import carriers during the establishment of the embryonic root cell pattern. Methods The radicle apex of single and multiple aux1 lax mutant mature embryos was used to evaluate the effect of this gene family upon embryonic root organization and root cap size, cell number and cell size. Key Results It was demonstrated here that mutations within the AUX1 LAX family are associated with changes in cell pattern establishment in the embryonic quiescent centre and columella. aux1 lax mutants have a larger radicle root cap than the wild type and this is associated with a significant increase in the root-cap cell number, average cell size, or both. Extreme disorganization of the radicle apex was observed among quadruple aux1 lax1 lax2 lax3 mutant embryos, but not in single aux1 null or in lax1, lax2 and lax3 single mutants, indicating redundancy within the AUX1 LAX family. Conclusions It was determined that the AUX1 LAX family of auxin influx facilitators participates in the establishment of cell pattern within the apex of the embryonic root in a gene-redundant fashion. It was demonstrated that aux1 lax mutants are affected in cell proliferation and cell growth within the radicle tip. Thus AUX1 LAX auxin importers emerge as new players in morphogenetic processes involved in patterning during embryonic root formation. PMID:19952011

Ugartechea-Chirino, Yamel; Swarup, Ranjan; Swarup, Kamal; Peret, Benjamin; Whitworth, Morag; Bennett, Malcolm; Bougourd, Sue

2010-01-01

287

Microdosage Rapide et Sensible de Proteines Immobilisees sur Support Insoluble: Applications aux Anticorps Immobilises sur Polystyrene  

Microsoft Academic Search

A rapid and sensitive method for the quantitation of microgram antibodies immobilized on polystyrene is proposed. A procedure of protein staining on polystyrene with coomassie, brilliant blue G 250 follows Beer's law after release of the coloured complex. The lower limits of detection are determined.

R. Couturier; B. Perrin; G. Favre-bonvin; A. Ville

1985-01-01

288

Comportement dynamique d'alliages a memoire de forme et application aux composites-AMF  

NASA Astrophysics Data System (ADS)

Meeting current industrial, governmental and international standards regarding vibration and noise levels is a challenging task facing many engineers. These specifications are present in just about all fields of engineering, from aerospace to marine transportation, from automotive to railway transportation, from computer equipment to industrial working environments. An appropriate use of the remarkable properties of high damping metals (HIDAMETS) and shape memory alloy (SMA) reinforced composites emerges as a possible solution to these problems. Among many obstacles to overcome in developing such a technology, the implementation of reliable and adequate characterization techniques to determine dynamic properties of these materials appears to be of prime importance. The research efforts presented in this thesis are aimed at developing advanced techniques to characterize the dynamic behavior of HIDAMETS and SMA reinforced composites. These characterization results lead to the enhancement of numerical (finite element) and/or analytical methods for the simulation of dynamic responses of structures made of these materials. In particular, the research work has focused on three themes: the numerical and experimental validation of applying a characterization procedure developed for traditional composites to SMA reinforced composites; the development of a test bench for uniaxial hysteresis characterization of HIDAMETS in the medium frequency range; the hysteresis characterization and modeling of manganese copper (MnCu) and nickel titanium samples. The results obtained in the course of these efforts show that the characterization technique developed for traditional composites at the University of Brussels is sufficiently precise to successfully predict natural frequencies of complex SMA reinforced composite structures. Using the characterization to predict structural damping ratios, we observe a bias error in the prediction with respect to experimental results although the relative values between modes are consistent. Regarding the development of the test bench for uniaxial hysteresis characterization of HIDAMETS, results suggest that with the introduction of a few minor enhancements and with particular experimental precautions, the test bench can play an important role in characterizing HIDAMETS dynamic properties at various frequencies and strain amplitudes and in understanding micro mechanical mechanisms responsible for energy dissipation. Finally, uniaxial hysteresis loops and related parameters have been obtained with MnCu and NiTi samples. A material model based on dual kriging interpolation that expresses the tangent stiffness along these hysteresis loops as a function of strain and strain amplitude has also been developed.

de Santis, Silvio

289

Access to Health Care and Social Protection L'accs aux soins de sant et la protection sociale  

E-print Network

Access to Health Care and Social Protection L'accès aux soins de santé et la protection sociale sécurité sociale et les pourvoyeurs de soins. Introduction In France, the access to health care is founded, the access to healthcare has been conceived as a social right and is mainly managed through the coverage

Boyer, Edmond

290

Le systme opiode endogne et laddiction aux drogues1  

PubMed Central

Rsum Laddiction aux drogues est une maladie psychiatrique chronique qui conduit dimportantes altrations adaptatives dans les circuits de rcompense du cerveau. Plusieurs systmes de neurotransmission sont impliqus dans ces modifications. Cependant, un des systmes neurochimiques qui joue un rle essentiel dans laddiction est le systme opiode endogne. Les rcepteurs opiodes et les peptides opiodes endognes sont trs largement prsents dans les structures crbrales qui contrlent les phnomnes de rcompense, en particulier le systme msolimbique. Ces rcepteurs et peptides opiodes participent dune manire slective plusieurs aspects des processus addictifs induits par les opiacs, les cannabinodes, les psychostimulants, lalcool et la nicotine. Cette revue rend compte de ltat actuel des connaissances sur la participation de chaque composante du systme opiode endogne dans les proprits addictives des diffrentes drogues. PMID:20176158

Maldonado, Rafael

2010-01-01

291

An early auxin-responsive Aux\\/IAA gene from wheat (Triticum aestivum) is induced by epibrassinolide and differentially regulated by light and calcium  

Microsoft Academic Search

The plant hormone auxin plays a central role in regulating many aspects of plant growth and develop- ment. This largely occurs as a consequence of changes in gene expression. The Aux\\/IAA genes are best characterized among the early auxin-responsive genes, which encode short-lived transcriptional repressors. In most plants examined, including Arabidopsis, soybean, and rice, the Aux\\/IAA genes constitute a large

Bhumica Singla; Archana Chugh; Jitendra P. Khurana; P. Khurana

2006-01-01

292

Guide l'intention des tudiants Bourses CRSNG, FQRNT, VANIER et autres Prparer une demande de bourse aux  

E-print Network

Guide à l'intention des étudiants Bourses CRSNG, FQRNT, VANIER et autres 2011 Préparer une demande de bourse aux études supérieures avec succès En tant qu'étudiant à Polytechnique, vous pouvez poser votre candidature pour plusieurs bourses qui pourront vous aider à assumer le coût de vos études. Ces

Skorobogatiy, Maksim

293

Les politiques alimentaires sont-elles adaptes aux changements d'habitudes alimentaires en Afrique au sud du Sahara ?  

Microsoft Academic Search

[fre] Le recours de plus en plus massif aux importations alimentaires en Afrique au sud du Sahara ne signifie pas ncessairement une dgradation gnrale de la production vivrire ou l'adoption d'un modle alimentaire extrieur, en ville notamment. Les habitudes alimentaires sont encore largement indpendantes des conditions d'approvisionnement, mais les prix relatifs des divers aliments commencent peser sur l'volution de

Georges Courade

1989-01-01

294

La distribution d'automobiles neuves en Europe est rgie par un rglement d'exemption aux rgles de la  

E-print Network

La distribution d'automobiles neuves en Europe est régie par un règlement d'exemption aux règles de contexte, les concessionnaires doivent repenser leur métier de distributeurs automobiles pour transformer les menaces en opportunités. Les spéculations sur l'avenir du système de la distribution automobile en

Paris-Sud XI, Université de

295

PROJET DE THESE COSTA RICA Evaluation des pertes de rcolte lies aux bioagresseurs dans une gamme de technicit de  

E-print Network

PROJET DE THESE COSTA RICA Evaluation des pertes de récolte liées aux bioagresseurs dans une gamme des systèmes de culture à base de café En Amérique centrale, le café est principalement cultivé en'intensification des systèmes de production. La conception de système de culture durable doit répondre à un

296

Du suicide de Mme Follin en 1828 aux suicides du dbut du XXe sicle: pour une tude  

E-print Network

Du suicide de Mme Follin en 1828 aux suicides du début du XXe siècle: pour une étude des violences'extinction du suicide, Revue de Rouen, 1844). Introduction Le 16 décembre 1828 le préfet de la Seine « suicide » chez les aliénés « fous moraux » ou suicidaires. L'ouverture des cerveaux permettrait de définir

Paris-Sud XI, Université de

297

Phloem-specific expression of a melon Aux/IAA in tomato plants alters auxin sensitivity and plant development.  

PubMed

Phloem sap contains a large repertoire of macromolecules in addition to sugars, amino acids, growth substances and ions. The transcription profile of melon phloem sap contains over 1000 mRNA molecules, most of them associated with signal transduction, transcriptional control, and stress and defense responses. Heterografting experiments have established the long-distance trafficking of numerous mRNA molecules. Interestingly, several trafficking transcripts are involved in the auxin response, including two molecules coding for auxin/indole acetic acid (Aux/IAA). To further explore the biological role of the melon Aux/IAA transcript CmF-308 in the vascular tissue, a cassette containing the coding sequence of this gene under a phloem-specific promoter was introduced into tomato plants. The number of lateral roots was significantly higher in transgenic plants expressing CmF-308 under the AtSUC2 promoter than in controls. A similar effect on root development was obtained after transient expression of CmF-308 in source leaves of N. benthamiana plants. An auxin-response assay showed that CmF-308-transgenic roots are more sensitive to auxin than control roots. In addition to the altered root development, phloem-specific expression of CmF-308 resulted in shorter plants, a higher number of lateral shoots and delayed flowering, a phenotype resembling reduced apical dominance. In contrast to the root response, cotyledons of the transgenic plants were less sensitive to auxin than control cotyledons. The reduced auxin sensitivity in the shoot tissue was confirmed by lower relative expression of several Aux/IAA genes in leaves and an increase in the relative expression of a cytokinin-response regulator, TRR8/9b. The accumulated data suggest that expression of Aux/IAA in the phloem modifies auxin sensitivity in a tissue-specific manner, thereby altering plant development. PMID:23986770

Golan, Guy; Betzer, Rotem; Wolf, Shmuel

2013-01-01

298

Que cache l'volution des prts bancaires aux Etats-Unis depuis la reprise 1992-1993 ?  

Microsoft Academic Search

[fre] Que cache l'volution des prts bancaires aux tats-Unis depuis la reprise 1992-1993 ?. . Les intermdiaires financiers amricains ont t accuss d'avoir contribu la persistance des difficults conomiques en se dtournant de leurs activits traditionnelles au cours de la dernire rcession. Cependant, plusieurs auteurs ont montr que la baisse de l'encours de crdit n'est pas seulement due au

Nada Matta

1995-01-01

299

Depositional facies and hydrocarbon reservoir compartmentalization of the Mississippian Aux Vases Formation at King Field, Jefferson County, Illinois  

SciTech Connect

King field has produced over 4 million bbl of oil from the Mississippian Aux Vases Formation along a north-south-trending anticlinal structure 3 mi long and 1.5 mi wide. The porous and permeable quartz sandstone, which comprises the principal hydrocarbon reservoir, can grade laterally into nonporous calcareous sandstone, siltstone, shale, or limestone within one well location (660 ft). The Aux Vases Formation at King field was deposited in an intertidal to subtidal, mixed siliciclastic-carbonate environment, and the resulting mosaic of depositional facies significantly affects reservoirs continuity. Impermeable to only slightly permeable siltstones, shales, and limestones of the various offshore facies, and shales and siltstones of the tidal-flat facies separate the producing sandstones of a tidal channel-offshore bar facies into distinct reservoir compartments. This reservoir heterogeneity results in an oil-water contact at various depths across the field. Lateral compartmentalization of the reservoir has allowed large sections of the Aux Vases reservoir to remain unswept by waterflooding. Volumetric analyses suggest that untapped reservoir compartments may contain an additional 1-2 million bbl of oil recoverable by primary and waterflood methods.

Leetaru, H.E. (Illinois State Geological Survey, Champaign (United States))

1991-08-01

300

Alkoxy-auxins are selective inhibitors of auxin transport mediated by PIN, ABCB, and AUX1 transporters.  

PubMed

Polar auxin movement is a primary regulator of programmed and plastic plant development. Auxin transport is highly regulated at the cellular level and is mediated by coordinated transport activity of plasma membrane-localized PIN, ABCB, and AUX1/LAX transporters. The activity of these transporters has been extensively analyzed using a combination of pharmacological inhibitors, synthetic auxins, and knock-out mutants in Arabidopsis. However, efforts to analyze auxin-dependent growth in other species that are less tractable to genetic manipulation require more selective inhibitors than are currently available. In this report, we characterize the inhibitory activity of 5-alkoxy derivatives of indole 3-acetic acid and 7-alkoxy derivatives of naphthalene 1-acetic acid, finding that the hexyloxy and benzyloxy derivatives act as potent inhibitors of auxin action in plants. These alkoxy-auxin analogs inhibit polar auxin transport and tropic responses associated with asymmetric auxin distribution in Arabidopsis and maize. The alkoxy-auxin analogs inhibit auxin transport mediated by AUX1, PIN, and ABCB proteins expressed in yeast. However, these analogs did not inhibit or activate SCF(TIR1) auxin signaling and had no effect on the subcellular trafficking of PIN proteins. Together these results indicate that alkoxy-auxins are inactive auxin analogs for auxin signaling, but are recognized by PIN, ABCB, and AUX1 auxin transport proteins. Alkoxy-auxins are powerful new tools for analyses of auxin-dependent development. PMID:21084292

Tsuda, Etsuko; Yang, Haibing; Nishimura, Takeshi; Uehara, Yukiko; Sakai, Tatsuya; Furutani, Masahiko; Koshiba, Tomokazu; Hirose, Masakazu; Nozaki, Hiroshi; Murphy, Angus S; Hayashi, Ken-ichiro

2011-01-21

301

Mecanismo(s) de Acci³n de los Herbicidas Aux­nicos - Parte 2 - Nivel Avanzado  

NSDL National Science Digital Library

Descripci³n:El control selectivo de malezas de hoja ancha en cultivos de cereales por los herbicidas aux­nicos ha hecho de ©stos una de las familias de herbicidas actualmente en uso mas ampliamente distribuidas e importantes. Se cree que estos herbicidas actºan como simuladores hormonales. En esta lecci³n se detallar¡ la relaci³n estructural y fisiol³gica entre los herbicidas aux­nicos y la fitohormona natural auxina (¡cido indol-3-ac©tico; IAA por sus siglas en ingl©s) y se explicar¡n los mecanismos bioqu­micos que pueden estar involucrados en su modo de acci³n. Se revisar¡ el mecanismo de transporte de c©lula a c©lula y la absorci³n de las auxinas por las c©lulas, as­ como tambi©n la forma en que estas mol©culas causan elongaci³n celular e inducen la s­ntesis de etileno. De igual forma, se describir¡n los receptores, las rutas de transferencia de se±ales y los cambios en expresi³n gen©tica inducidos por la fitohormona natural IAA y su relaci³n con la actividad de los herbicidas aux­nicos.

302

Protocoles d'applications Le courrier lectronique  

E-print Network

1 1 Protocoles d'applications Le courrier électronique IUT d'Orsay réseauxIUT Bordeaux 1 2 Divers, gestion de courrier ou des news dans des dossiers 3 SMTP Simple Mail Transfer Protocol [RFC 821 : 1982] 4, supprimer du courrier sur une machine distante Boîte aux lettres POP3 ou IMAP MX.d2.xx MUA sur B.d2.yy #12

Johnen, Colette

303

Tectonic conditions of hydrothermal polymetallic vein-type mineralization, Sainte Marie-aux-Mines, France  

NASA Astrophysics Data System (ADS)

The Sainte-Marie-aux-Mines (SMM) mines host one of the most famous and oldest silver deposits in Europe. The SMM district is located in the central part of the Vosges mountains, France, within gneiss and granites of the Moldanubian zone. The SMM district includes the Neuenberg E-W vein-type Cu-Ag-As/Pb-Zn deposit and the Altenberg N-S vein-type Pb-Zn-Ag deposit. Deposition of the SMM hydrothermal mineralization occurred under a brittle tectonic regime that might be connected to neo-Variscan and/or post-Variscan tectonics, in a similar way as the polymetallic vein deposits of the Black Forest, Germany. A structural study was done in the Neuenberg area, in the vicinity of the Saint-Jacques vein, and within the Gabe Gottes mine, considering the orientation, extent, chronology and density of faults as well as the nature of the infilling minerals. In the Gabe-Gottes mine, the Saint-Jacques vein comprises multiple successive, sub-parallel subvertical veinlets with gangue minerals, mostly carbonates and quartz, and metal-bearing phases, sulfides and sulfosalts. The veinlets are 2 to 50 cm thick and strike N80 to N110, the earlier veins slightly dipping towards the north, and the latest one, to the south. Seven systems of faults were identified, which may be classified into three major groups formed respectively before, during and after the main stage of ore deposition: a) Pre-mineralization faults - These consist of sinistral NE-SW strike-slip faults, and NW-SE and NE-SW steeply dipping normal faults. These could be related to Carboniferous events considering their relationships with the granitoid intrusives present in the mine area (Brzouard leucogranite ~329 Ma), and the extensional tectonics developed during exhumation processes. b) Faults associated with the main ore-deposition - These faults could be related to late-Hercynian processes from compressional to extensional tectonic regimes. Mineralization controlling faults consist of dextral and sinistral E-W strike-slip faults. Early strike-slip movements are assessed by the presence of striated iron oxides, the crystallization of which is considered to be early during the ore deposition process. Mineralizing fluids were probably fluorine-rich as F-bearing minerals, sericite, chlorite and apatite are present in the chlorite zone associated with early sulphide-rich ores. The E-W mineralized faults are only easily compatible with the tectonics known in Permian times. c) Late-stage faults - These could be related to the numerous changes in plate configuration which occur during the Mesozoic and Cenozoic times, in accordance with the creation of the Paris basin, the opening of Atlantic ocean and Rhine Graben, as well as with the Tethys closure. For example, the vertical lineation superposed on an horizontal lineation observed on mineralized rocks indicate reactivation of the former E-W mineralized veins under a normal movement. The latter may correspond to an extensive regime known during Oligocene times. On the other hand, one of the major late-stage faults strikes N-S and is related to a dextral strike-slip system, which could be considered as Miocene. It is expected that fluid remobilization occurred during fault reactivation, a process which could have led to successive ore deposition following the emplacement of the major E-W mineralized veins. A fluid inclusion study in the gangue minerals of the Gabe Gottes is now under investigation. This together with isotopic studies will help to determine the source of the mineralizing fluids, as well as the conditions of ore deposition. Keywords: Faults, polymetallic mineralization, variscan orogeny, Gabe-Gottes, Sainte-Marie-aux-Mines, Vosges, F-rich fluids.

Hafeznia, Y.; Bourlange, S.; Ohnenstetter, M.

2012-04-01

304

Ectopic Overexpression of an AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) Gene OsIAA4 in Rice Induces Morphological Changes and Reduces Responsiveness to Auxin  

PubMed Central

Auxin has pleiotropic effects on plant growth and development. AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins are short-lived transcriptional regulators that mediate auxin responses through interaction with an auxin receptor, the F-box protein transport inhibitor response 1 (TIR1). Most functions of Aux/IAA proteins have been identified in Arabidopsis by studying the gain-of-function mutants in domain II. In this study, we isolated and identified an Aux/IAA protein gene from rice, OsIAA4, whose protein contains a dominant mutation-type domain II. OsIAA4 has very low expression in the entire life cycle of rice. OsIAA4-overexpressing rice plants show dwarfism, increased tiller angles, reduced gravity response, and are less sensitive to synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D). PMID:23812082

Song, Yaling; Xu, Zeng-Fu

2013-01-01

305

Intro Architectures HTML/xHTML CSS Formulaires PHP MVC JavaScript Securite Applications interactives  

E-print Network

Intro Architectures HTML/xHTML CSS Formulaires PHP MVC JavaScript S´ecurit´e Applications cours de Mireille Jouve 1 / 125 #12;Intro Architectures HTML/xHTML CSS Formulaires PHP MVC JavaScript S Formulaires PHP MVC JavaScript S´ecurit´e Objectifs Pourquoi ce cours ? Objectifs th´eoriques introduction aux

Ligozat, Anne-Laure

306

Strotypes et motivation autodtermine 1 Relation entre les strotypes sexus associs aux pratiques sportives et la motivation  

E-print Network

Stéréotypes et motivation autodéterminée 1 Relation entre les stéréotypes sexués associés aux pratiques sportives et la motivation autodéterminée des élèves en éducation physique et sportive Aïna et Motricité 66 (2009) 61-70" #12;Stéréotypes et motivation autodéterminée 2 Résumé Cette étude

Paris-Sud XI, Université de

307

Programme de bourses aux tudes suprieures Page 1 Procdures et rglements (adopts par le Comit de direction le 18 juin 2012, rviss le 26 octobre 2012)  

E-print Network

Programme de bourses aux études supérieures Page 1 Procédures et règlements (adoptés par le Comité de direction le 18 juin 2012, révisés le 26 octobre 2012) PROGRAMME DE BOURSES AUX ?TUDES SUP?RIEURES Procédures et règlements Les bourses de maîtrise et de doctorat de la Faculté de médecine et des sciences de

Spino, Claude

308

Light-dependent gravitropism and negative phototropism of inflorescence stems in a dominant Aux/IAA mutant of Arabidopsis thaliana, axr2.  

PubMed

Gravitropism and phototropism of the primary inflorescence stems were examined in a dominant Aux/IAA mutant of Arabidopsis, axr2/iaa7, which did not display either tropism in hypocotyls. axr2-1 stems completely lacked gravitropism in the dark but slowly regained it in light condition. Though wild-type stems showed positive phototropism, axr2 stems displayed negative phototropism with essentially the same light fluence-response curve as the wild type (WT). Application of 1-naphthaleneacetic acid-containing lanolin to the stem tips enhanced the positive phototropism of WT, and reduced the negative phototropism of axr2. Decapitation of stems caused a small negative phototropism in WT, but did not affect the negative phototropism of axr2. p-glycoprotein 1 (pgp1) pgp19 double mutants showed no phototropism, while decapitated double mutants exhibited negative phototropism. Expression of auxin-responsive IAA14/SLR, IAA19/MSG2 and SAUR50 genes was reduced in axr2 and pgp1 pgp19 stems relative to that of WT. These suggest that the phototropic response of stem is proportional to the auxin supply from the shoot apex, and that negative phototropism may be a basal response to unilateral blue-light irradiation when the levels of auxin or auxin signaling are reduced to the minimal level in the primary stems. In contrast, all of these treatments reduced or did not affect gravitropism in wild-type or axr2 stems. Tropic responses of the transgenic lines that expressed axr2-1 protein by the endodermis-specific promoter suggest that AXR2-dependent auxin response in the endodermis plays a more crucial role in gravitropism than in phototropism in stems but no significant roles in either tropism in hypocotyls. PMID:24938853

Sato, Atsuko; Sasaki, Shu; Matsuzaki, Jun; Yamamoto, Kotaro T

2014-09-01

309

Applications  

NASA Astrophysics Data System (ADS)

Economic incentives have spurred numerous applications of genetically engineered organisms in manufacture of pharmaceuticals and industrial chemicals. These successes, involving a variety of methods of genetic manipulation, have dispelled early fears that genetic engineering could not be handled safely, even in the laboratory. Consequently, the potential for applications in the wider environment without physical containment is being considered for agriculture, mining, pollution control, and pest control. These proposed applications range from modest extensions of current plant breeding techniques for new disease-resistant species to radical combinations of organisms (for example, nitrogen-fixing corn plants). These applications raise concerns about potential ecological impacts (see chapter 5), largely because of adverse experiences with both deliberate and inadvertent introductions of nonindigenous species.

Stern, Arthur M.

1986-07-01

310

ERADICATION OF CROWN OF THORNS STARFISH (ACANTHASTER PLANCI) INFESTATION IN A PATCH REEF IN THE LAGOON OFF ILE AUX CERFS, MAURITIUS  

Microsoft Academic Search

The Crown of Thorns (COTs) starfish is a natural predator of live corals. It was observed in unusually high numbers in the patch reef between Ile aux Cerfs and the fringing reef. This paper describes how Crown of Thorns infestation was effectively controlled by injection of dry acid in situ through diving without any adverse effect on the marine environment

V Mangar

311

17 `eme Congr`es Francais de Mecanique Troyes, septembre 2005 Generateur de conditions aux limites amont pour les simulations de type  

E-print Network

17 `eme Congr`es Franc¸ais de M´ecanique Troyes, ­ septembre 2005 G´en´erateur de conditions aux´ecomposition a ´et´e choisie car elle permet d'extraire les 1 #12;17 `eme Congr`es Franc¸ais de M´ecanique Troyes

312

Quelques conseils pratiques pour la prparation et la slection des dossiers de bourses Le concours annuel des bourses Vanier est arrim aux organismes subventionnaires  

E-print Network

Quelques conseils pratiques pour la préparation et la sélection des dossiers de bourses Vanier Le concours annuel des bourses Vanier est arrimé aux organismes subventionnaires fédéraux suivent présentent quelques conseils utiles pour la préparation des dossiers de bourses Vanier

Parrott, Lael

313

Manuscrit auteur publi dans Urbanisme, dossier villes indiennes, n355, juillet-aot 2007, Dynamiques d'urbanisation : des megacities aux villages urbains  

E-print Network

-50 1 Dynamiques d'urbanisation : des megacities aux villages urbains Kamala Marius-Gnanou1 et François. Moriconi-Ebrard (http://ifpindia.org/Built-Up-Areas-in-India-e- GEOPOLIS.html ) 4 Dans les frontières

Paris-Sud XI, Université de

314

Agostinelli, S. (2008). Six questions aux approches franaises des didactiques scientifiques appliques au e-learning. In, S. Agostinelli & M. Ranieri, (Eds.) The scientific didactical approaches  

E-print Network

appliquées au e-learning. In, S. Agostinelli & M. Ranieri, (Eds.) The scientific didactical approaches of e-learning - the French experience. Journal of e-Learning and Knowledge Society, 4(2), 147- 162. Six questions aux approches francophones des didactiques scientifiques appliquées au e-learning Professeur Serge Agostinelli

Paris-Sud XI, Université de

315

Anisotropy of the magnetic susceptibility of CeCu6-xAux near the quantum phase transition  

NASA Astrophysics Data System (ADS)

We report on the low-temperature dc magnetic susceptibility of CeCu6-xAux(x=0.1) in very small fields B=100 ?T and 1 mT. For x=0.1, i.e. for the quantum critical concentration, we confirm the anomalous exponent ? of the susceptibility along the easy c-direction, ?c-1??+T? with ?=0.8 observed previously in moderate fields B=100 mT (see, A. Schrder, et al., Nature 407 (2000) 351). However, below 240 mK we see a clear additional contribution to ?c. At the lowest measuring temperature T=40 mK, the ratio ?c:?a:?b=4:1.5:1 of the susceptibility anisotropy is weaker than at higher T where the ratio is 10:2:1. This is caused by a steeper increase of ?a and ?b as compared to ?c.

Tomanic, T.; Hamann, A.; Lhneysen, H. v.

2008-04-01

316

Spectroscopie d'emission VUV-visible provenant de plasmas basse pression: Applications aux traitements de surfaces polymeriques  

NASA Astrophysics Data System (ADS)

The main objective of this thesis is to make a contribution to the spectroscopic study of low pressure glow discharges in the vacuum ultraviolet and to reveal the effect of this radiation on polymeric materials. This research considers the following important aspects relevant to low pressure glow discharges: (i)characterization of vacuum ultraviolet (VUV) emission of several plasmas in the wavelength range available through crystalline fluoride windows, (ii)analysis of the emission dependence on several external parameters, and (iii)study of the VUV effect, in the accessible range, on polymeric materials of interest with respect to plasma treatments. The plasmas investigated, namely, hydrogen, oxygen and their mixtures with argon, were chosen by taking into consideration the composition of the gases used in technological plasmas, and the conditions needed for polymeric material irradiation. Two separate spectrophotometric instruments, a VUV monochromator (ARC VM-502) and an optical multichannel analyzer (OMA), were used. For the chosen plasmas, we measured the variation of the intensity of the atomic lines for different gas pressures and absorbed power levels. In the case of pure gas plasmas, the pressure dependence of the atomic line intensities was attributed to changes in the electron energy distribution function (EEDF). The argon emission spectra are very sensitive to the presence of impurities. The mixture plasmas we have studied (Ar-H2 and Ar-O2) show a strong emission of atomic fines in the VUV region, stronger than those resulting from the pure molecular gases. The above mixtures show promise as photon sources for the treatment of polymer surfaces. An important external parameter for the characterization of glow discharges is the excitation frequency. The goal of the specific experiments was to directly investigate the frequency-dependence effect. The frequency-related effects on plasma emission were investigated for two plasmas: pure hydrogen and 7% H2 in Ar mixture. In the case of pure hydrogen, we observed a change from a non-stationary to a stationary electron energy distribution function. For the Ar-H2 mixture, we have shown that the EEDF is stationary and that the dissociation rate for hydrogen molecules does not depend on frequency. A difference between the excitation mechanisms of different atomic lines was proven. Among the most sensitive materials with respect to plasma generated UV radiation are polymers. We have optimized the gaseous composition for various types of VUV radiation fluxes for the photochemical treatments of polymers. We have developed a system containing a thermo-stabilized quartz crystal microbalance (QCM) and chambers for sample irradiation and gas absorption measurements. In this way we have separately measured the effects of both the active oxygen species (AO) and the VUV, as well as their synergistic actions. (Abstract shortened by UMI.)

Fozza, Alexandru C.

317

Apport des mthodes de dure de vie au domaine de l'assurance. Application aux contrats d'assurances automobiles  

E-print Network

'assurances automobiles K. Boukhetala *, J.M. Marion**, A. Oulidi** * USTHB - Département de Probabilités et Statistiques-paramétriques. On étudiera plus particulièrement le phénomène de résiliation de contrats d'assurances automobiles d vie de contrats d'assurance automobile afin de mieux gérer le phénomène de résiliation de contrats. En

Paris-Sud XI, Université de

318

Ecologie des transferts de contaminants dans les rseaux trophiques: application Echinococcus multilocularis et aux lments trace mtalliques.  

E-print Network

??Il est maintenant tabli que les changements anthropiques d'utilisation des terres (dforestation, irrigation, agriculture ...), les modifications de la biodiversit et les changements climatiques sont (more)

Raoul, Francis

2013-01-01

319

AN EXPERIMENT IN AGRICULTURAL CREDIT: THE SMALL FARMER GROUP LENDING PROGRAMME IN GHANA (1969-1980) \\/ UN EXPERIMENT DE CREDIT AGRICOLE: LE PROGRAMME DE CREDIT AUX GROUPES DE PETITS EXPLOITANTS AGRICOLES AU GHANA (1969-1980)  

Microsoft Academic Search

Cet article analyse en dtail le programme de crdit aux regroupements de petits exploitants mis en place par la Agricultural Development Bank (ADB) au Ghana dans la priode 1969-1980. Avant 1969, la Banque n'avait pas russi actroyer du crdit aux millions de petits exploitants qui produisent la plus grande partie de l'Output agricole du pays. l'poque, le crdit

Kwame Opoku Owusu; William Tetteh

1982-01-01

320

La gopolitique locale-globale aux marges de la City de Londres : conflits autour des projets de renouvellement urbain de Bishopsgate  

E-print Network

1 La géopolitique locale-globale aux marges de la City de Londres : conflits autour des projets de renouvellement urbain de Bishopsgate Publiés dans Hérodote n°137, p. 119-134, sour le titre Conflits d convoité par les promoteurs, peine à faire consensus, comme l'attestent différents conflits médiatisés. S

Paris-Sud XI, Université de

321

Analyse des effets boursiers suite aux changements de dirigeants : le cas des entreprises du NASDAQ et de l'OTC depuis mars 2000  

Microsoft Academic Search

Jusqu'en dcembre 2001, le thme de la gouvernance, bien qu'important, ne reprsentait pas ncessairement un dfi d'ampleur pour les entreprises. Puis, survinrent Enron et les autres cas de fraude qui s'ajoutaient aux problmes rencontrs par les entreprises de la nouvelle conomie. Ces bouleversements ont fait raliser quel point les entreprises (mme les plus grandes) peuvent tre dans certains cas

Alain Finet; Ral Labelle

2003-01-01

322

Synth`ese de l'enquete destin'ee aux b'en'eficiaires de bourses de formation ` a et par  

E-print Network

Synth`ese de l'enqu??ete destin'ee aux b'en'eficiaires de bourses de formation ` a et par la'enqu??ete porte sur la perception qu'ont les boursiers des bourses parfois improprement nomm'ees ``bourses sur crit`eres sociaux''. Le questionnaire a 'et'e envoy'e `a tous les b'en'eficiaires de ce type de bourses

Bertrand, Benoît

323

Interaction of the Tobacco Mosaic Virus Replicase Protein with the Aux\\/IAA Protein PAP1\\/IAA26 Is Associated with Disease Development  

Microsoft Academic Search

Virus-infected plants often display developmental abnormalities that include stunting, leaf curling, and the loss of apical dominance. In this study, the helicase domain of the Tobacco mosaic virus (TMV) 126- and\\/or 183-kDa replicase protein(s) was found to interact with the Arabidopsis Aux\\/IAA protein PAP1 (also named IAA26), a putative regulator of auxin response genes involved in plant development. To investigate

Meenu S. Padmanabhan; Sameer P. Goregaoker; Sheetal Golem; Haiymanot Shiferaw; James N. Culver

2005-01-01

324

Rflexions sur le transfert mthodologique de l'analyse qualitative d'accidents de la circulation routire issue de l'tude dtaille des accidents (EDA) franaise aux  

E-print Network

1 Réflexions sur le transfert méthodologique de l'analyse qualitative d'accidents de la circulation routière issue de l'étude détaillée des accidents (EDA) française aux procédures d'accidents colombiennes Mécanismes d'accidents (MA) - Institut Français des Sciences et Technologies des Transports, de l

Paris-Sud XI, Université de

325

Analyse XPS des surfaces de Si et SiO2 exposes aux plasmas de CHF3 et CHF32014C2F6. Polymrisation et gravure  

E-print Network

309 Analyse XPS des surfaces de Si et SiO2 exposées aux plasmas de CHF3 et CHF32014C2F6 exposées à des plasmas de CHF3 et CHF32014C2F6 sont caractérisées par spectroscopie de photoélectrons (XPS and CHF32014C2F6 RF plasmas (RIE mode) are characterized by X-ray Photoelectron Spectroscopy (XPS

Boyer, Edmond

326

Niveau socio?conomique et processus du recours aux soins par les familles de patients souffrant de troubles psychiques au Burkina Faso  

PubMed Central

Introduction Le Burkina Faso a connu une amlioration constante depuis deux dcennies de l'offre de soins en psychiatrie. De mme, le taux d'alphabtisation sans cesse croissant s'accompagne d'une profonde modification des conceptions et des comportements. La prsente tude visait dterminer l?impact des dterminants socioconomiques sur le processus du recours aux soins par les familles. Mthodes Il s'est agi d'une enqute transversale portant sur 200 familles, mene dans le service de psychiatrie du Centre Hospitalier Universitaire Yalgado Oudraogo de Ouagadougou. Variable expliquer: premier recours aux soins par les familles (gurisseur traditionnel ou prires religieuses vs. consultations psychiatrique ou mdicale). Variable explicative: catgorie socioprofessionnelle classe en suivant la nomenclature des professions et catgories socioprofessionnelles; niveau dtudes. L'analyse statistique a t effectue l'aide du logiciel SAS version 9.2. Le test du Khi deux a t utilis. Rsultats Il existait une association entre le choix du premier recours et la Profession et la catgorie socioprofessionnelledu dcideur (p = 0.0006) ainsi que leniveau dtudes du dcideur (p = 0.0001). Conclusion La Profession et Catgorie Sociale et le niveau d'instruction scolaire pourraient tre un marqueur important dans les politiques visant optimiser les processus de recours aux soins des patients dans le circuit de soins. PMID:25161751

Yaogo, Ahmed; Sommer, Alain; Moulai, Pierre; Chebili, Said; Abaoub-Germain, Agnes

2014-01-01

327

Expression Pattern of Aux/IAA Genes in the iaa3/shy2?1D Mutant of Arabidopsis thaliana (L.)  

PubMed Central

A semi?dominant mutant suppressor of hy2 (shy2?1D) of Arabidopsis thaliana, originally isolated as a photomorphogenesis mutant, shows altered auxin responses. Recent molecular cloning revealed that the SHY2 gene is identical to the IAA3 gene, a member of the primary auxin?response genes designated the Aux/IAA gene family. Because Aux/IAA proteins are reported to interact with auxin response factors, we investigated the pattern of expression of early auxin genes in the iaa3/shy2?1D mutant. RNA hybridization analysis showed that levels of mRNA accumulation of the early genes were reduced dramatically in the iaa3/shy2?1D mutants, although auxin still enhanced gene expression in the iaa3/shy2?1D mutant. Histochemical analysis using a fusion gene of the auxin responsive domain (AuxRD) and the GUS gene showed no IAA?inducible GUS expression in the root elongation zone of the iaa3/shy2?1D mutant. On the other hand, ectopic GUS expression occurred in the hypocotyl, cotyledon, petiole and root vascular tissues in the absence of auxin. These results suggest that IAA3/SHY2 functions both negatively and positively on early auxin gene expression. PMID:12096821

OONO, YUTAKA; OOURA, CHIHARU; UCHIMIYA, HIROFUMI

2002-01-01

328

Electrofiltration: An Energy Efficient Alternative in Solid-Liquid Separations  

E-print Network

The field is generated by placing twp electrodes in the slurry and applying 'a D.C. voltage across the electrodesL Electrons flow from the voltage sourc~ into the cathode and are consumed by the reduction half-reaction: 2e + 2H 2 0+H 2 t + 20M (4...). BUt it is the electric! field between the anode and cathode that drives electrophoresis, and the electro filtration process. The three regions of interest in electrofiltration are shown in Figure 8. The two opposing electrodes are SUbmerged in the feed slurry. A...

Bollinger, J. M.; Adams, R. A.

1984-01-01

329

Intermediate couplings: NMR at the solids-liquids interface  

NASA Astrophysics Data System (ADS)

Anisotropic interactions like dipolar couplings and chemical shift anisotropy have long offered solid-state NMR spectroscopists valuable structural information. Recently, solution-state NMR structural studies have begun to exploit residual dipolar couplings of biological molecules in weakly anisotropic solutions. These residual couplings are about 0.1% of the coupling magnitudes observed in the solid state, allowing simple, high-resolution NMR spectra to be retained. In this work, we examine the membrane-associated opioid, leucine enkephalin (lenk), in which the ordering is ten times larger than that for residual dipolar coupling experiments, requiring a combination of solution-state and solid-state NMR techniques. We adapted conventional solid-state NMR techniques like adiabatic cross- polarization and REDOR for use with such a system, and measured small amide bond dipolar couplings in order to determine the orientation of the amide bonds (and therefore the peptide) with respect to the membrane surface. However, the couplings measured indicate large structural rearrangements on the surface and contradict the published structures obtained by NOESY constraints, a reminder that such methods are of limited use in the presence of large-scale dynamics.

Spence, Megan

2006-03-01

330

Intermetallic phase formation in thin solid-liquid diffusion couples  

SciTech Connect

Conducting joints with low fabrication temperatures and high thermal stability are useful in modern electronics. This paper discusses the potential use of intermetallic phases in making such joints. Thin interconnection layers that consist entirely of intermetallic phases have been produced by joining planar Cu substrates that are coated with thin films of Sn. Thin layers (1-5 {mu}m) of intermetallic phases are produced at temperatures slightly above the melting temperature of Sn in a process similar to reflow soldering. Metallography and x-ray analysis are used to characterize the formation mechanism of the intermetallic. Cu dissolves into the liquid Sn by diffusion along narrow channels between grains of the growing {eta}-Cu{sub 6}Sn{sub 5} intermetallic phase. tensile tests were used to measure mechanical properties. The joint strength increased with reaction time. The joint fails in a ductile mode as long as unreacted Sn is present, but fractures along interphase boundaries when the joint is completely intermetallic. 6 refs., 5 figs.

Bartels, F.; Morris, J.W. Jr. [Lawrence Berkeley Lab., CA (United States); Dalke, G.; Gust, W. [Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany)

1994-08-01

331

Solid-Liquid Lithium Divertor Experiment: SLiDE  

NASA Astrophysics Data System (ADS)

Liquid lithium has been proposed as a material for the first wall and divertor/limiter of a fusion device. One objection raised against the use of liquid lithium is the high vapor pressure at modest temperature increases. Recent experiments on the CDX-U device show however, that lithium absorbs a surface heat flux of greater than 40 MW/m^2 with negligible evaporation. Observation of a focused electron beam hitting solid lithium in the CDX-U lithium tray saw melting of a large section of the tray. Macroscopic liquid flows were observed which redistributed the incident power. Surface tension effects caused by temperature gradients have been proposed as a mechanism for this convection. These flows were insensitive to MHD effects in fields up to 600G [1]. This paper presents a design of an experiment which will diagnose the flows induced by an intense heat flux onto a lithium pool and measure the maximum heat flux lithium can absorb in an incident magnetic field. A number of diagnostics are considered and evaluated with the goal of being minimally invasive to the induced flows. These results are the first step in the creation of an experimental facility to study the heat transfer capabilities of free-surface liquid lithium at the University of Illinois. [1] Majeski, et al., Final results from the CDX-U lithium program, Presentation at APS-DPP05, Denver, Colorado. 2005.

Jaworski, Michael; Ruzic, David

2006-10-01

332

Manifold to uniformly distribute a solid-liquid slurry  

DOEpatents

This invention features a manifold that divides a stream of coal particles and liquid into several smaller streams maintaining equal or nearly equal mass compositions. The manifold consists of a horizontal, variable area header having sharp-edged, right-angled take-offs which are oriented on the bottom of the header.

Kern, Kenneth C. (Lake Hiawatha, NJ)

1983-01-01

333

Gestion des ressources hydriques adaptee aux changements climatiques pour la production optimale d'hydroelectricite. Etude de cas: Bassin versant de la riviere Manicouagan  

NASA Astrophysics Data System (ADS)

Il est dorenavant etabli que les changements climatiques auront des repercussions sur les ressources en eau. La situation est preoccupante pour le secteur de production d'energie hydroelectrique, car l'eau constitue le moteur pour generer cette forme d'energie. Il sera important d'adapter les regles de gestion et/ou les installations des systemes hydriques, afin de minimiser les impacts negatifs et/ou pour capitaliser sur les retombees positives que les changements climatiques pourront apporter. Les travaux de la presente recherche s'interessent au developpement d'une methode de gestion des systemes hydriques qui tient compte des projections climatiques pour mieux anticiper les impacts de l'evolution du climat sur la production d'hydroelectricite et d'etablir des strategies d'adaptation aux changements climatiques. Le domaine d'etude est le bassin versant de la riviere Manicouagan situe dans la partie centrale du Quebec. Une nouvelle approche d'optimisation des ressources hydriques dans le contexte des changements climatiques est proposee. L'approche traite le probleme de la saisonnalite et de la non-stationnarite du climat d'une maniere explicite pour representer l'incertitude rattachee a un ensemble des projections climatiques. Cette approche permet d'integrer les projections climatiques dans le probleme d'optimisation des ressources en eau pour une gestion a long terme des systemes hydriques et de developper des strategies d'adaptation de ces systemes aux changements climatiques. Les resultats montrent que les impacts des changements climatiques sur le regime hydrologique du bassin de la riviere Manicouagan seraient le devancement et l'attenuation de la crue printaniere et l'augmentation du volume annuel d'apports. L'adaptation des regles de gestion du systeme hydrique engendrerait une hausse de la production hydroelectrique. Neanmoins, une perte de la performance des installations existantes du systeme hydrique serait observee a cause de l'augmentation des deversements non productibles dans le climat futur. Des strategies d'adaptation structurale ont ete analysees pour augmenter la capacite de production et la capacite d'ecoulement de certaines centrales hydroelectriques afin d'ameliorer la performance du systeme. Une analyse economique a permis de choisir les meilleures mesures d'adaptation et de determiner le moment opportun pour la mise en oeuvre de ces mesures. Les resultats de la recherche offrent aux gestionnaires des systemes hydriques un outil qui permet de mieux anticiper les consequences des changements climatiques sur la production hydroelectrique, incluant le rendement de centrales, les deversements non productibles et le moment le plus opportun pour inclure des modifications aux systemes hydriques. Mots-cles : systemes hydriques, adaptation aux changements climatiques, riviere Manicouagan

Haguma, Didier

334

Foam flotation of zeolites: Application for zinc ion removal  

SciTech Connect

In this paper the solid/liquid separation of a NaY zeolite, a known cation exchanger, was investigated in the laboratory by foam flotation from aqueous suspensions. The main parameters affecting the process in batch experiments, such as the pH of the suspension, the type of collector, the cationic collector concentration, the zeolite concentration, and the ionic strength were examined. The optimum conditions for removal (flotation) of more than 95% of the zeolite were determined. Following flotation of the zeolite in the Na form, zinc ions were chosen to serve as an application for ion exchange by the zeolite (for metal recovery), followed by foam flotation of the exchanged form of the zeolite from solution.

Zouboulis, A.I.; Zamboulis, D.; Matis, K.A. (Aristotle Univ., Thessaloniki (Greece))

1991-01-01

335

Chapter 5 Laser Ablation at the Solid/Liquid Interface 138 Chapter 5 Laser Ablation at the Solid/Liquid  

E-print Network

of both white and red phosphorus under various carbon containing liquids will be presented. From ablation of graphite under water was clear in appearance, containing a visible suspended black solid. After

Bristol, University of

336

Waste Heat Boilers for Incineration Applications  

E-print Network

Incineration is a widely used process for disposing of solid, liquid and gaseous wastes generated in various types of industries. In addition to destroying pollutants, energy may also be recovered from the waste gas streams in the form of steam...

Ganapathy, V.

337

Electrochemical dealloying of Al2(Au,X) (X = Pt, Pd, PtPd, Ni, Co and NiCo) alloys in NaCl aqueous solution.  

PubMed

The electrochemical dealloying of rapidly solidified Al2(Au,X) (X = Pt, Pd, PtPd, Ni, Co and NiCo) precursors in a 1.0 M NaCl aqueous solution has been systematically investigated using electrochemical measurements including open-circuit measurement, potentiodynamic polarization and potentiostatic polarization, and microstructural analysis. The results show that the kind of alloying element(s) has a significant influence on the open-circuit and corrosion potentials of the rapidly solidified Al2(Au,X) precursors. The bulk dealloying of the Al2(Au,X) precursors is affected by the kind of alloying element(s) and also sensitive to the applied potential (or overpotential). The addition of Ni or/and Co easily leads to passivation on the surface of precursors during potentiostatic dealloying. The potentiostatic dealloying of Al2(Au,Pt), Al2(Au,Pd) and Al2(Au,Pt,Pd) results in the formation of ultrafine nanoporous AuPt, AuPd and AuPtPd alloys, owing to the pinning effect of Pt or/and Pd on surface diffusion of Au adatoms. In comparison, the potentiostatic dealloying of Al2(Au,Ni), Al2(Au,Co) and Al2(Au,Ni,Co) leads to the formation of nanoporous Au with a ligament/channel size of ~40 nm due to the simultaneous dissolution of Al and Ni/Co. Moreover, the addition of Pt, Pd or PtPd not only inhibits surface diffusion of Au adatoms (lower diffusivities), but also improves the activation energy for the diffusion process during potentiostatic dealloying. Based upon the present results, nanoporous metals or alloys can be greenly fabricated through electrochemical dealloying in NaCl solutions. PMID:23455475

Wang, Yan; Xu, Junling; Wu, Bo

2013-04-21

338

Multiple AUX/IAA-ARF modules regulate lateral root formation: the role of Arabidopsis SHY2/IAA3-mediated auxin signalling.  

PubMed

In Arabidopsis thaliana, lateral root (LR) formation is regulated by multiple auxin/indole-3-acetic acid (Aux/IAA)-AUXIN RESPONSE FACTOR (ARF) modules: (i) the IAA28-ARFs module regulates LR founder cell specification; (ii) the SOLITARY-ROOT (SLR)/IAA14-ARF7-ARF19 module regulates nuclear migration and asymmetric cell divisions of the LR founder cells for LR initiation; and (iii) the BODENLOS/IAA12-MONOPTEROS/ARF5 module also regulates LR initiation and organogenesis. The number of Aux/IAA-ARF modules involved in LR formation remains unknown. In this study, we isolated the shy2-101 mutant, a gain-of-function allele of short hypocotyl2/suppressor of hy2 (shy2)/iaa3 in the Columbia accession. We demonstrated that the shy2-101 mutation not only strongly inhibits LR primordium development and emergence but also significantly increases the number of LR initiation sites with the activation of LATERAL ORGAN BOUNDARIES-DOMAIN16/ASYMMETRIC LEAVES2-LIKE18, a target gene of the SLR/IAA14-ARF7-ARF19 module. Genetic analysis revealed that enhanced LR initiation in shy2-101 depended on the SLR/IAA14-ARF7-ARF19 module. We also showed that the shy2 roots contain higher levels of endogenous IAA. These observations indicate that the SHY2/IAA3-ARF-signalling module regulates not only LR primordium development and emergence after SLR/IAA14-ARF7-ARF19 module-dependent LR initiation but also inhibits LR initiation by affecting auxin homeostasis, suggesting that multiple Aux/IAA-ARF modules cooperatively regulate the developmental steps during LR formation. PMID:22527388

Goh, Tatsuaki; Kasahara, Hiroyuki; Mimura, Tetsuro; Kamiya, Yuji; Fukaki, Hidehiro

2012-06-01

339

Orienter des fragments molculaires et des molcules grce aux couplages dipolaires rsiduels  

NASA Astrophysics Data System (ADS)

Many proteins and nucleic acids, as well as their complexes, consist of structural units with a known internal structure. However, relative position of these units within the entity is often a subject of uncertainty. This problem can be effectively addressed with the help of residual dipolar couplings (RDCs) measured by solution-state NMR in weakly oriented samples. Using a rigid-body approach, the relative orientation of the structural units can be adjusted to match the experimental RDC data. This paper explains why the rigid-body approach is well suited for application with the RDC data and discusses the general algorithm suitable for such studies. The examples of RDC-based rigid-body treatment involving protein backbone fragments, RNA helices, multidomain proteins, protein-ligand systems, and protein complexes are described in detail. The discussion includes systems where multiple structures co-exist in a dynamic equilibrium. Various degeneracies associated with the RDC data are considered and the methods that can assist in resolving the ambiguities are described. To cite this article: N.R. Skrynnikov, C. R. Physique 5 (2004).

Skrynnikov, Nikolai R.

2004-04-01

340

PHENOMENES LIES AUX NOYAUX COMPOSES S e r v i c e de Physique Theorique, CEN Saclay, BP n02 -91, Gif-sur-Yvette  

E-print Network

PHENOMENES LIES AUX NOYAUX COMPOSES C. Bloch S e r v i c e de Physique Theorique, CEN Saclay, BP n r e n c e s consid6rables s u i v a n t l e s d i f f e r e n t s N. Bohr e n 1936 e s t pratiquement a u s s i v i e i l l e Q t a t s n u c l e a i r e s e n t r e le-s i n t e g r a l e s d e

Boyer, Edmond

341

QCM sur le programme des TD7 et TD8 Vous devez pouvoir rpondre aux questions avec les tables distribues et une calculatrice.  

E-print Network

Correction QCM sur le programme des TD7 et TD8 Vous devez pouvoir répondre aux questions avec les, B, C et D, avec probabilité pA, pB, pC, pD. On a récolté un échantillon de telles variables, les eectuer le test suivant, en utilisant un test du 2 : H0 : pA = 0.4; pB = 0.4; pC = 0.1; pD = 0.1. Ha : (p

Barré, Julien

342

Mecanismo(s) de Acci³n de las Auxinas y los Herbicidas Aux­nicos - Parte 1- Introducci³n  

NSDL National Science Digital Library

Descripci³n:El control selectivo de malezas de hoja ancha en cultivos de cereales utilizando herbicidas aux­nicos ha hecho de ©stos una de las familias de herbicidas actualmente en uso m¡s ampliamente distribuidas e importantes. Estos herbicidas fueron los primeros herbicidas org¡nicos desarrollados que presentaron selectividad; es decir, capaces de matar un cierto grupo de plantas sin afectar a otros grupos (por ejemplo: matar plantas de hoja ancha pero no las de hoja angosta; en este documento se utilizar¡ el t©rmino "gram­neas" para referirse a las plantas de hoja angosta o cereales). En esta lecci³n se presentar¡n las principales caracter­sticas de los herbicidas aux­nicos, se discutir¡n sus principales usos y se describir¡n los s­ntomas de da±o que causan. De igual forma, se indicar¡ la forma en que estos herbicidas matan a las plantas sensibles.

343

Phase relations in the system NaCl-KCl-H2O: IV. Differential thermal analysis of the sylvite liquidus in the KCl-H2O binary, the liquidus in the NaCl-KCl-H2O ternary, and the solidus in the NaCl-KCl binary to 2 kb pressure, and a summary of experimental data for thermodynamic-PTX analysis of solid-liquid equilibria at elevated P-T conditions  

USGS Publications Warehouse

The sylvite liquidus in the binary system KCl-H2O and the liquidus in the ternary system NaCl-KCl-H2O were determined by using isobaric differential thermal analysis (DTA) cooling scans at pressures up to 2 kbars. Sylvite solubilities along the three-phase curve in the binary system KCl-H2O were obtained by the intersection of sylvite-liquidus isopleths with the three-phase curve in a P-T plot. These solubility data can be represented by the equation Wt.% KCl (??0.2) = 12.19 + 0.1557T - 5.4071 ?? 10-5 T2, where 400 ??? T ??? 770??C. These data are consistent with previous experimental observations. The solidus in the binary system NaCl-KCl was determined by using isobaric DTA heating scans at pressures up to 2 kbars. Using these liquidus and solidus data and other published information, a thermodynamic-PTX analysis of solid-liquid equilibria at high pressures and temperatures for the ternary system has been performed and is presented in an accompanying paper (Part V of this series). However, all experimental liquidus, solidus, and solvus data used in this analysis are summarized in this report (Part IV) and they are compared with the calculated values based on the analysis. ?? 1992.

Chou, I.-M.; Sterner, S.M.; Pitzer, K.S.

1992-01-01

344

Phase relations in the system NaCl-KCl-H sub 2 O: IV. Differential thermal analysis of the sylvite liquidus in the KCl-H sub 2 O binary, the liquidus in the NaCl-KCl-H sub 2 O ternary, and the solidus in the NaCl-KCl binary to 2 kb pressure, and a summary of experimental data for thermodynamic-PTX analysis of solid-liquid equilibria at elevated P-T conditions  

SciTech Connect

The sylvite liquidus in the binary system KCl-H{sub 2}O and the liquidus in the ternary system NaCl-KCl-H{sub 2}O were determined by using isobaric differential thermal analysis (DTA) cooling scans at pressures up to 2 kbars. Sylvite solubilities along the three-phase curve in the binary system KCl-H{sub 2}O were obtained by the intersection of sylvite-liquidus isopleths with the three-phase curve in a P-T plot. These solubility data can be represented by the equation Wt.% KCl ({plus minus}0.2) = 12.19 + 0.1557T {minus} 5.4071 {times} 10{sup {minus}5}T{sup 2}, where 400 {le} T {le} 770C. These data are consistent with previous experimental observations. The solidus in the binary system NaCl-KCl was determined by using isobaric DTA heating scans at pressures up to 2 kbars. Using these liquidus and solidus data and other published information, a thermodynamic-PTX analysis of solid-liquid equilibria at high pressures and temperatures for the ternary system has been performed and is presented in an accompanying paper (Part 5 of this series). However, all experimental liquidus, solidus, and solvus data used in this analysis are summarized in this report (Part 4) and they are compared with the calculated values based on the analysis.

Iming Chou (Geological Survey, Reston, VA (United States)); Sterner, S.M.; Pitzer, K.S. (Univ. of California, Berkeley, CA (United States))

1992-06-01

345

Des Artefacts aux Programmes  

Microsoft Academic Search

For some years, ontology research has investigated the field of computer programs, the main objective being to have at one's disposal formal descriptions of the programs so as to master their design and use. In line with these efforts, we currently develop a \\

Gilles Kassel; Pascal Lando; Anne Lapujade

346

Transposition des gros vaisseaux associ?e aux communications interventriculaire et interauriculaire: ? propos d'un cas et revue de la litt?rature  

PubMed Central

Nous rapportons une observation d'un nourrisson de 5 mois prsentant une transposition des gros vaisseaux associe aux communications interventriculaire et interauriculaire. Il est n terme sans aucun facteur de risque retrouv dans les antcdents maternels. Le diagnostic est pos, grce une chocardiographie, 5 mois aprs sa naissance lors de la survenue d'une cyanose et d'un malaise anoxique. Une prise en charge symptomatique a permis de stabiliser ltat du patient mais suite l'absence d'un traitement chirurgical, il est dcd domicile 3 semaines aprs sa sortie de l'hpital. Dans les pays en dveloppement, le diagnostic de la transposition des gros vaisseaux est souvent fait en priode postnatale et son pronostic reste fatal par manque des centres mdico-chirurgicaux spcialiss. PMID:24009800

Mutombo, Augustin Mulangu; Mukuku, Olivier; Lubala, Toni Kasole; Kabuya, Maguy Sangaji; Ilunga, Paul Makinko; Bugeme, Marcellin; Luboya, Oscar Numbi

2013-01-01

347

Application of electro acoustics for dewatering pharmaceutical sludge  

SciTech Connect

Application of electro acoustic principles for dewatering has been developed by Battelle Institute. The Department of Energy, Battelle Institute, and Ashbrook-Simon-Hartley, have jointly developed an Electro Acoustic Dewatering press (EAD press). The EAD press applies a combination of mechanical pressure, electrical current and ultrasonics. This press is utilized after conventional dewatering devices and can remove up to 50% water from filtered sludge cake at a fraction of the cost incurred in existing thermal drying devices. The dominant mechanism of sludge dewatering by EAD press is electro-osmosis due to the application of a direct current field. Electro-osmosis is caused by an electrical double layer of oppositely charged ions formed at the solid liquid interface, which is characterized by zeta potential. The ultrasonic fields help electro-osmosis by consolidation of the filter cake and by release of inaccessible liquid. The EAD press has been tested successfully on a variety of materials including apple pomace, corn gluten, sewage sludge, and coal fines. A three week long full scale trial was conducted successfully at a pharmaceutical industry to determine the application of this technology for dewatering waste activated sludge.

Golla, P.S.; Johnson, H.W. (Ashbrook-Simon-Hartley, Houston, TX (United States)) Senthilnathan, P.R. (Zenon Environmental Inc., Burlington, Ontario (Canada))

1992-02-01

348

L'evolution des obstacles aux echanges et les entreprises canadiennes : survie et disparition apres l'Accord de libre-echange entre le Canada et les Etats-Unis  

Microsoft Academic Search

Ce document permet d'examiner les consequences de l'evolution des obstacles aux echanges sur la survie des entreprises manufacturieres au Canada. Nous avons elabore un modele de Cournot a marches segmentes pour decrire les effets de la liberalisation des echanges sur des entreprises heterogenes exploitees dans diverses branches d'activite. Nous testons les previsions de ce modele empiriquement a l'aide de donnees

Jennifer Baggs

2004-01-01

349

Cdric Audebert & Andr Calmont (2007) Immigration antillaise et diversit sociale de la population noire aux Etats-Unis , in Andr Calmont et Cdric Audebert (dir.) Dynamiques migratoires de la Carabe,  

E-print Network

Cédric Audebert & André Calmont (2007) « Immigration antillaise et diversité sociale de la Caraïbe, Paris : Géode /Karthala, pp. 77-92. (Terres d'Amérique) 1 Immigration antillaise et diversité croissante de l'immigration contemporaine aux ?tats-Unis constitue un défi pour une société organisée sur la

Boyer, Edmond

350

LES APPORTS DE LA THEORIE DU CONTRAT SOCIAL A L'EXPLICATION DES RUPTURES DE RELATIONS DE LONG TERME ENTRE ORGANISATIONS : UNE APPLICATION AUX RELATIONS BANQUES\\/PME  

Microsoft Academic Search

Cet article vise montrer la pertinence du cadre d'analyse des normes contractuelles de Macneil pour expliquer les ruptures de relations de long terme entre organisations. Pour ce faire des entretiens ont t conduits sur 13 dyades chargs d'affaires\\/reprsentants de PME. Une analyse quantitative a ensuite t conduite sur 300 PME.

Isabelle Prim-Allaz; Jean Perrien; Bernard Pras

2001-01-01

351

Tilt and strain deformation induced by hydrologically-active natural fractures. Application to the tiltmeters installed in Sainte-Croix-aux-Mines observatory (France).  

E-print Network

Florsch 2 4 5 , Fr´ed´eric Boudin 6 , Ludovic Oudin 2 , Christian Camerlynck 2 Review III, submitted is that they are also sensitive to environmental influences, especially hydrological influences that may have amplitudes methods have been developed in order to model hydrological influences, using linear or non- linear models

352

Etude analytique et numrique de la rponse en vibration hautes frquences d'prouvettes de fatigue vibratoire des mtaux. Application aux aciers  

NASA Astrophysics Data System (ADS)

In the present paper, the so-called " ultrasonic fatigue " or fatigue at very high frequency has been studied in the materials elastic behaviour case while neglecting the thermal effects that influence the mechanical fields. The determination of mechanical fields and specimen resonance length has been done both analytically and numerically. The numerical method used for this calculation is the finite element method (FEM). Martensitic steel " Soleil A2 " and austenitic steel " ICL 472 BC " have been considered in order to compare the two methods (analytical and numerical). It is shown that a perfect convergence is obtained between the two solutions. Dans le prsent travail, la fatigue vibratoire a t tudie dans le cas du comportement lastique des matriaux en ngligeant les effets thermiques pouvant influencer les champs mcaniques. La dtermination de ces champs et de la longueur de rsonance des prouvettes de fatigue a t faite analytiquement et numriquement. Le calcul numrique effectu se base sur la mthode des lments finis. Dans le but d'une comparaison des solutions analytiques et numriques, deux aciers ont t considrs : un acier martensitique (Soleil A2) et un acier austnitique de type 18-10 (ICL 472 BC). Une parfaite convergence est obtenue entre les deux solutions.

Ben Aich, A.; El Kihel, B.; Kifani, A.; Sahban, F.

1994-07-01

353

Interaction of the Tobacco Mosaic Virus Replicase Protein with the Aux/IAA Protein PAP1/IAA26 Is Associated with Disease Development  

PubMed Central

Virus-infected plants often display developmental abnormalities that include stunting, leaf curling, and the loss of apical dominance. In this study, the helicase domain of the Tobacco mosaic virus (TMV) 126- and/or 183-kDa replicase protein(s) was found to interact with the Arabidopsis Aux/IAA protein PAP1 (also named IAA26), a putative regulator of auxin response genes involved in plant development. To investigate the role of this interaction in the display of symptoms, a TMV mutant defective in the PAP1 interaction was identified. This mutant replicated and moved normally in Arabidopsis but induced attenuated developmental symptoms. Additionally, transgenic plants in which the accumulation of PAP1 mRNA was silenced exhibit symptoms like those of virus-infected plants. In uninfected tissues, ectopically expressed PAP1 accumulated and localized to the nucleus. However, in TMV-infected tissues, PAP1 failed to accumulate to significant levels and did not localize to the nucleus, suggesting that interaction with the TMV replicase protein disrupts PAP1 localization. The consequences of this interaction would affect PAP1's putative function as a transcriptional regulator of auxin response genes. This is supported by gene expression data indicating that ?30% of the Arabidopsis genes displaying transcriptional alterations in response to TMV contain multiple auxin response promoter elements. Combined, these data indicate that the TMV replicase protein interferes with the plant's auxin response system to induce specific disease symptoms. PMID:15681455

Padmanabhan, Meenu S.; Goregaoker, Sameer P.; Golem, Sheetal; Shiferaw, Haiymanot; Culver, James N.

2005-01-01

354

Pronounced matrix effect in YbMo2Al4-type Ca(AuxZn2-x)Au4 (x=0.09-0.89)  

NASA Astrophysics Data System (ADS)

Electron-poor polar intermetallics Ca(AuxZn2-x)Au4 have been synthesized through fusion of stoichiometric metals in sealed tantalum tubes at 800 C and annealing at 400 C for one week. Single crystal X-ray diffraction analyses reveal that this phase belongs to the YbMo2Al4-type structure (I4/mmm, Pearson symbol tI14), a?6.943-7.017 , c?5.278-5.286 , Z=2, with homogeneous composition range of x=0.09(1)-0.89(1). The structure exhibits a three-dimensional framework of (Au8)1/2 featuring square and octagonal channels extending in c, in which Ca and the infinite linear chains of [(Au,Zn)2]1/2 are located, respectively. Mulliken population analyses demonstrate that Zn prefers to form the linear chains in the whole homogeneous composition range, consistent with experimental observations. Crystal orbital Hamilton population (COHP) analyses reveal that the channel-to-chain Au-Zn contact has strong bonding interactions regardless of its large interatomic distance (~2.85 ), a signature of pronounced matrix effect. The last mentioned effect in YbMo2Al4-type structures is expected in case the linear chains are defined by small size atoms.

Mishra, Trinath; Lin, Qisheng; Corbett, John D.

2014-10-01

355

Rapport soumis aux rapporteurs, dans le but de sanctionner le dossier pour l'obtention du grade de  

E-print Network

Docteur en Math´ematiques Appliqu´ees et Informatique de l'INPG Segmentation des tissus et structures sur segmentation : un maillon crucial dans de nombreuses applications . . . 24 2.4.3 Evaluation de la segmentation . . . . . . . . . . . . . . . . . . . . . . . . . 26 3 Segmentation des IRM c´er´ebrales 27 3.1 Diff´erentes familles d'approches de la segmentation

Dojat, Michel

356

A study of the applicability of nucleation theory to quasi-thermodynamic transitions of second and higher Ehrenfest-order, supplement 3  

NASA Technical Reports Server (NTRS)

The work includes an investigation of the applicability of the nucleation theory to second and higher order thermodynamic transitions in the Ehrenfest sense, and a number of significant conclusions relevant to first order transitions, as well. The underlying theoretical method consisted of expanding the Gibbs' free energy in a Maclarin or Taylor series and then using fundamental thermodynamic determinable quantities, and interpreting the results. Work was performed on the existence and interpretation of an interfacial energy between phases in a second order transition in addition to an investigation of the solid-liquid interfacial energy for various polymers. Extensive considerations were devoted to various aspects of a particular polymer, polyvinylidene fluoride (PVDF or PVF2), including an experimetal investigation of the effects of an applied electric field on the morphology of melt crystallization and on the nucleation and growth of polarized domains.

Barker, R. E., Jr.

1986-01-01

357

UBC13, an E2 enzyme for Lys63-linked ubiquitination, functions in root development by affecting auxin signaling and Aux/IAA protein stability.  

PubMed

Unlike conventional lysine (K) 48-linked polyubiquitination, K63-linked polyubiquitination plays signaling roles in yeast and animals. Thus far, UBC13 is the only known ubiquitin-conjugating enzyme (E2) specialized in K63-linked polyubiquitination. Previous identification of Arabidopsis genes encoding UBC13 as well as its interacting partner UEV1 indicates that the UBC13-mediated ubiquitination pathway is conserved in plants; however, little is known about functions and signaling mediated through K63-linked polyubiquitination in plants. To address the functions of UBC13-mediated ubiquitination in plants, we created Arabidopsis ubc13 null mutant lines in which the two UBC13 genes were disrupted. The double mutant displayed altered root development, including shorter primary root, fewer lateral roots and only a few short root hairs in comparison with the wild type and single mutant plants, indicating that UBC13 activity is critical for all major aspects of root development. The double mutant plants were insensitive to auxin treatments, suggesting that the strong root phenotypes do not simply result from a reduced level of auxin. Instead, the ubc13 mutant had a reduced auxin response, as indicated by the expression of an auxin-responsive DR5 promoter-GFP. Furthermore, both the enzymatic activity and protein level of an AXR3/IAA17-GUS reporter were greatly increased in the ubc13 mutant, whereas the induction of many auxin-responsive genes was suppressed. Collectively, these results suggest that Aux/IAA proteins accumulate in the ubc13 mutant, resulting in a reduced auxin response and defective root development. Hence, this study provides possible mechanistic links between UBC13-mediated protein ubiquitination, root development and auxin signaling. PMID:25142088

Wen, Rui; Wang, Sheng; Xiang, Daoquan; Venglat, Prakash; Shi, Xianzong; Zang, Yuepeng; Datla, Raju; Xiao, Wei; Wang, Hong

2014-11-01

358

Full dimensional Franck-Condon factors for the acetylene A? (1)Au-X? ?g+1 transition. II. Vibrational overlap factors for levels involving excitation in ungerade modes.  

PubMed

A full-dimensional Franck-Condon calculation has been applied to the A? (1)Au-X? ?g+1 transition in acetylene in the harmonic normal mode basis. Details of the calculation are discussed in Part I of this series. To our knowledge, this is the first full-dimensional Franck-Condon calculation on a tetra-atomic molecule undergoing a linear-to-bent geometry change. In the current work, the vibrational intensity factors for levels involving excitation in ungerade vibrational modes are evaluated. Because the Franck-Condon integral accumulates away from the linear geometry, we have been able to treat the out-of-plane component of trans bend (?4 ('')) in the linear X? state in the rotational part of the problem, restoring the ? Euler angle and the a-axis Eckart conditions. A consequence of the Eckart conditions is that the out-of-plane component of ?4 ('') does not participate in the vibrational overlap integral. This affects the structure of the coordinate transformation and the symmetry of the vibrational wavefunctions used in the overlap integral, and results in propensity rules involving the bending modes of the X? state that were not previously understood. We explain the origin of some of the unexpected propensities observed in IR-UV laser-induced fluorescence spectra, and we calculate emission intensities from bending levels of the A? state into bending levels of the X? state, using normal bending mode and local bending mode basis sets. Our calculations also reveal Franck-Condon propensities for the Cartesian components of the cis bend (?5 ('')), and we predict that the best A?-state vibrational levels for populating X?-state levels with large amplitude bending motion localized in a single C-H bond (the acetylene?vinylidene isomerization coordinate) involve a high degree of excitation in ?6 (') (cis-bend). Mode ?4 (') (torsion) populates levels with large amplitude counter-rotational motion of the two hydrogen atoms. PMID:25296804

Park, G Barratt; Baraban, Joshua H; Field, Robert W

2014-10-01

359

The Aux/IAA gene rum1 involved in seminal and lateral root formation controls vascular patterning in maize (Zea mays L.) primary roots.  

PubMed

The maize (Zea mays L.) Aux/IAA protein RUM1 (ROOTLESS WITH UNDETECTABLE MERISTEMS 1) controls seminal and lateral root initiation. To identify RUM1-dependent gene expression patterns, RNA-Seq of the differentiation zone of primary roots of rum1 mutants and the wild type was performed in four biological replicates. In total, 2 801 high-confidence maize genes displayed differential gene expression with Fc ?2 and FDR ?1%. The auxin signalling-related genes rum1, like-auxin1 (lax1), lax2, (nam ataf cuc 1 nac1), the plethora genes plt1 (plethora 1), bbm1 (baby boom 1), and hscf1 (heat shock complementing factor 1) and the auxin response factors arf8 and arf37 were down-regulated in the mutant rum1. All of these genes except nac1 were auxin-inducible. The maize arf8 and arf37 genes are orthologues of Arabidopsis MP/ARF5 (MONOPTEROS/ARF5), which controls the differentiation of vascular cells. Histological analyses of mutant rum1 roots revealed defects in xylem organization and the differentiation of pith cells around the xylem. Moreover, histochemical staining of enlarged pith cells surrounding late metaxylem elements demonstrated that their thickened cell walls displayed excessive lignin deposition. In line with this phenotype, rum1-dependent mis-expression of several lignin biosynthesis genes was observed. In summary, RNA-Seq of RUM1-dependent gene expression in maize primary roots, in combination with histological and histochemical analyses, revealed the specific regulation of auxin signal transduction components by RUM1 and novel functions of RUM1 in vascular development. PMID:24928984

Zhang, Yanxiang; Paschold, Anja; Marcon, Caroline; Liu, Sanzhen; Tai, Huanhuan; Nestler, Josefine; Yeh, Cheng-Ting; Opitz, Nina; Lanz, Christa; Schnable, Patrick S; Hochholdinger, Frank

2014-09-01

360

Advanced in situ Spectroscopic Techniques And Their Applications In Environmental Biogeochemistry: Introduction To The Special Section  

EPA Science Inventory

Understanding the molecular-scale complexities and interplay of chemical and biological processes of contaminants at solid, liquid, and gas interfaces is a fundamental and crucial element to enhance our understanding of anthropogenic environmental impacts. The ability to describ...

361

Privilges offerts aux entreprises et aux fondations donatrices  

E-print Network

activités annuelles exclusives. · La mention du nom de l'entreprise ou de la fondation dona- trice dans la dona- trice dans le site Web du Bureau du développement et des relations avec les diplômés, sous la

Charette, André

362

Services aux tudiants Maison internationale  

E-print Network

versements de bourse de mobilité du ministère de l'?ducation, du Loisir et du Sport du Québec (MELS), voici réception de cette preuve, la Maison internationale procédera à la commande du chèque de bourse de mobilité valeur ajoutée à votre formation; · Commentaires ou suggestions à faire; IMPORTANT Il faut que votre

Montréal, Université de

363

Services aux tudiants Maison internationale  

E-print Network

remettre la bourse de mobilité en vertu du Programme de bourses pour de courts séjours universitaires à l recherche au terme de la période pour laquelle vous avez obtenu la bourse de mobilité. Le rapport d'accueil a représenté une valeur ajoutée à votre formation; · Commentaires ou suggestions à faire. IMPORTANT Il faut que

Charette, André

364

Services aux tudiants Maison internationale  

E-print Network

avons le plaisir de vous remettre la bourse de mobilité en vertu du Programme de bourses pour de courts'accueil a représenté une valeur ajoutée à votre formation; · Commentaires ou suggestions à faire. IMPORTANT Il faut que internationale au plus tard UN MOIS après la fin de la période pour laquelle vous avez obtenu la bourse de

Montréal, Université de

365

Services aux tudiants Maison internationale  

E-print Network

plaisir de vous remettre la bourse de mobilité en vertu du Programme de bourses pour de courts séjours; · Expliquer en quoi l'expérience à l'étranger au sein de l'institution d'accueil a représenté une valeur MOIS après la fin de la période pour laquelle vous avez obtenu la bourse de mobilité. Nous vous

Charette, André

366

Differential Effects of NAA and 2,4-D in Reducing Floret Abscission in Cestrum (Cestrum elegans) Cut Flowers are Associated with their Differential Activation of Aux/IAA Homologous Genes  

PubMed Central

Background and Aims A previous study showed that the relative effectiveness of 2,4-dichlorophenoxyacetic acid (2,4-D) compared with that of 1-naphthaleneacetic acid (NAA) in reducing floret bud abscission in cestrum (Cestrum elegans) cut flowers was due to its acropetal transport. The aim of the present study was to examine if the differential effect of these auxins on floret abscission is reflected in the expression of Aux/IAA genes in the floret abscission zone (AZ). Methods cDNAs were isolated by PCR-based cloning from the floret AZ of auxin-treated cut flowers. The expression patterns of the cDNAs in various tissues and the effect of indole-3-acetic acid (IAA), applied with or without cycloheximide, on their expression in the floret AZ were examined by northern blot analysis. The regulation of transcript accumulation in the floret AZ in response to NAA or 2,4-D was measured by real-time PCR during auxin pulsing of cut flowers and vase life, concomitantly with floret abscission. Key Results Six isolated cDNAs were identified to represent Aux/IAA homologous genes, designated as Cestrum elegans (Ce)-IAA1 to Ce-IAA6. Four Ce-IAA genes were characterized as early auxin-responsive genes (ARGs), and two (Ce-IAA1 and Ce-IAA5) as late ARGs. Only Ce-IAA5 was AZ-specific in floret buds. A temporal regulation of Ce-IAA transcript levels in the floret AZ was found, with 2,4-D inducing higher expression levels than NAA in floret buds. These Ce-IAA expression levels were negatively correlated with floret abscission. Conclusions The differential transport characteristics of NAA and 2,4-D in cestrum cut flowers were reflected in differential activation of the Ce-IAA genes identified in the floret AZ. Therefore, Aux/IAA genes can be used as molecular markers to measure auxin activity, which reflects free auxin level in the AZ. Two of the identified genes, Ce-IAA1 and Ce-IAA5, may also have a regulatory role in abscission. PMID:17591611

Abebie, Bekele; Lers, Amnon; Philosoph-Hadas, Sonia; Goren, Raphael; Riov, Joseph; Meir, Shimon

2008-01-01

367

Coarsening in Solid-Liquid Mixtures-2: A Materials Science Experiment for the ISS.  

National Technical Information Service (NTIS)

A materials science experiment has been developed and readied for operation abroad the International Space Station (ISS). Components of this experiment are onboard ISS and are awaiting the flight of science samples. The goal of the experiment is to unders...

J. M. Hickman

2005-01-01

368

Elucidating the solid, liquid and gaseous products from batch pyrolysis of cotton-gin trash.  

E-print Network

CO 2 increase as compared to fossil fuels (Boateng et al., 2006). Biomass resources such as forest residues, agricultural residues, and municipal solid wastes are composed of organic raw materials that can be converted to energy (Caglar...?20 s 50 20 30 Slow Low temperature, around 400?C, very long residence times 30 35 35 Source: EIA (2007). Flash pyrolysis of agricultural residue using plasma-heated, laminar-entrained flow reactor is described by Shuangning et al. (2005...

Aquino, Froilan Ludana

2009-05-15

369

The influence of the solid/liquid interface on the dewetting of ultra thin polymer films  

NASA Astrophysics Data System (ADS)

In recent years, many studies showed that a thin liquid film on a solid surface in air bears more complexity than expected from a simple three-layer-system: e.g. a highly mobile surface layer in case the liquid is an unentangled polystyrene (PS) melt (Yang et al., Science 2010; Seemann et al., J. of Polym. Sci. 2006) or the PS melt can slip over the solid substrate (Baeumchen et al., PRL 2009). Our study focuses on such phenomena and explores their influence on dewetting (speed, morphology, etc.). We use hydrophilic and -phobic Si wafer (either covered by a highly ordered silane layer or by a thin layer of an amorphous fluoropolymer, AF 1600). On each of the substrates, one expects for a certain set of parameters spinodal dewetting for the PS melt. Yet experimentally, a much higher hole density is observed for both types of hydrophobic wafers than is theoretically expected. Moreover, the two hydrophobic coatings induce different dewetting speeds: the PS melt dewets faster on the silane covered Si wafer. The difference is attributed to slip (silane) or to no slip (AF 1600) conditions at the PS/substrate interface, which is also observable in the type of liquid front profile, which in turn changes the dewetting morphology.

Lessel, Matthias; Klos, Mischa; Baeumchen, Oliver; Jacobs, Karin

2012-02-01

370

Growth of amorphous silicon nanowires via a solidliquidsolid mechanism  

Microsoft Academic Search

Amorphous silicon nanowires (a-SiNW) with an average diameter of ca. 20 nm were synthesized at about 950C under an Ar\\/H2 atmosphere on a large area of a (111) Si substrate without supplying any gaseous or liquid Si sources. The Si substrate, deposited with a layer of Ni (ca. 40 nm thick), served itself as a silicon source for the growth

H. F Yan; Y. J Xing; Q. L Hang; D. P Yu; Y. P Wang; J Xu; Z. H Xi; S. Q Feng

2000-01-01

371

ELECTRON TRANSFER MECHANISM AT THE SOLID-LIQUID INTERFACE OF PHYLLOSILICATES  

EPA Science Inventory

Interfacial electron transfer processes on clay minerals have significant impact in natural environments and geochemical systems. Nitrobenzene was used as molecular probes to study the electron transfer mechanism at the solid-water interfaces of Fe-containing phyllosicates. For...

372

Efficient molecular recognition based on nonspecific van der Waals interaction at the solid/liquid interface.  

PubMed

A highly efficient recognition phenomenon was observed between alkoxylated arylene-ethynylene macrocycles bearing identical side chains but different core size, which is based on van der Waals interactions between alkoxy chains. The ratio of both molecules and the environment of each molecule have been statistically analyzed to quantify the recognition efficiency. PMID:25162067

Cao, Lili; Xu, Lirong; Zhao, Dahui; Tahara, Kazukuni; Tobe, Yoshito; De Feyter, Steven; Lei, Shengbin

2014-10-14

373

Studies of Intermetallic Growth in Cu-Solder Systems and Wettability at Solid-Liquid Interfaces.  

National Technical Information Service (NTIS)

The metallurgical bond formed between tin-lead solder and the copper substrate is characterized by the formation of an intermetallic layer. The growth of the intermetallic layer is the result of competing mechanisms, growth of the intermetallic at the int...

R. W. Martin

1991-01-01

374

Solid-Liquid Phase Transition As a Mechanism of Volcano Eruption  

E-print Network

This paper considers the formation of the magma volcano chamber and its eruption due to melting of the matter within the earth crust because of heating caused by plastic deformation occurring during tectonic movement. The expansion of matter in the magma chamber which takes place during its heating, leads to elastic stresses in the solid shell surrounding the magma chamber. The elastic energy of such stresses can be as high as 10^17 J per 1 km3 of the melt. The magma flow rate has been assessed according to available data, which agrees well with the observation data. The mechanism of low-frequency vibrations produced by the magma chamber is discussed. The vibrations result from the excess elastic energy formed during melting at the eruption steady stage. The suggested radiation theory allows evaluating the size of the magma chamber according to parameters that can be measured. The obtained theoretical evaluation of the magma chamber size is supported by the available observation data.

Alexander Ivanchin; Alexander Vikulin

2012-06-25

375

Solid-Liquid Phase Transition As a Mechanism of Volcano Eruption  

E-print Network

This paper considers the formation of the magma volcano chamber and its eruption due to melting of the matter within the earth crust because of heating caused by plastic deformation occurring during tectonic movement. The expansion of matter in the magma chamber which takes place during its heating, leads to elastic stresses in the solid shell surrounding the magma chamber. The elastic energy of such stresses can be as high as 10^17 J per 1 km3 of the melt. The magma flow rate has been assessed according to available data, which agrees well with the observation data. The mechanism of low-frequency vibrations produced by the magma chamber is discussed. The vibrations result from the excess elastic energy formed during melting at the eruption steady stage. The suggested radiation theory allows evaluating the size of the magma chamber according to parameters that can be measured. The obtained theoretical evaluation of the magma chamber size is supported by the available observation data.

Ivanchin, Alexander

2012-01-01

376

A unified correlation for estimating HHV of solid, liquid and gaseous fuels  

Microsoft Academic Search

A unified correlation for computation of higher heating value (HHV) from elemental analysis of fuels is proposed in this paper. This correlation has been derived using 225 data points and validated for additional 50 data points. The entire spectrum of fuels ranging from gaseous, liquid, coals, biomass material, char to residue-derived fuels has been considered in derivation of present correlation.

S. A. Channiwala; P. P. Parikh

2002-01-01

377

SESAME 96170, a solid-liquid equation of state for CeO2  

Microsoft Academic Search

I describe an equation of state (EOS) for the low-pressure solid phase and liquid phase of cerium (IV) oxide, CeO. The models and parameters used to calculate the EOS are presented in detail, and I compare with data for the full-density crystal. Hugoniot data are available only for high-porosity powders, and I discuss difficulties in comparing with such data. I

Chisolm; Eric D

2012-01-01

378

Thermodynamic and rheological properties of solid-liquid systems in coal processing  

SciTech Connect

None of the models available in the literature are known to work very well for aromatic compounds such as the ones that occur in coal derived materials. Two models - one by Van Velzen et al. (Ind Eng. Chem. Fundam. Vol 11, 1972, pp. 20-25) using a group contribution method and the other by Hwang et al (Ind. Eng. Chem. Process Des. Dev., Vol. 21, 1982, pp. 127-134) using a corresponding states method - were tested for some typical compounds that occur in coal liquids. These methods give errors ranging from 10 to 50% for viscosities of such compounds. These errors are too high and considering further errors in extension of these models to coal liquids, these models were considered unacceptable in our work. We have therefore set out to develop a new model for viscosities of aromatic compounds. We plan to base the model on the procedure similar to that of Van Velzen, however developed for just aromatic compounds. Our model, once developed will therefore be a group contribution method centered around the benzene ring structure.

Kabadi, V.N.; Ilias, S.

1992-01-01

379

Response of a solidliquid two-phase partitioning bioreactor to transient BTEX loadings  

Microsoft Academic Search

A two-phase partitioning bioreactor (TPPB) consisting of an aqueous phase containing a bacterial consortium and a polymeric phase of silicone rubber pellets (solid volume fraction 0.1) was used to treat a gaseous waste stream containing benzene, toluene, ethylbenzene and o-xylene (BTEX). The function of the solid polymer phase was to absorb\\/desorb the gaseous volatile organic compounds providing a buffering effect

Jennifer V. Littlejohns; Andrew J. Daugulis

2008-01-01

380

Teaching Sustainable Development Concepts in the Laboratory: A Solid-Liquid Extraction Experiment  

ERIC Educational Resources Information Center

One of the principles of sustainable development is to replace chemicals traditionally derived from oil with alternative, renewable materials. For example, phenol and phenol derivatives currently used in the manufacture of wood adhesives can be replaced (at least in part) by biopolymers extracted from biomass. In this work, pine bark (a renewable

Parajo, Juan Carlos; Dominguez, Herminia; Santos, Valentin; Alonso, Jose Luis; Garrote, Gil

2008-01-01

381

Thermal conductance of solid-liquid interfaces Scott Huxtable, Zhenbin Ge, David G. Cahill  

E-print Network

composites and suspensions · Localization of thermal effects: medical therapy/biotechnology #12;Interface of the conductance? "heat capacity G" vs. "heat conduction G" #12;Comparisons between experiment and simulation

Braun, Paul

382

Optical luminescence studies of the xanthate adsorption layer at the solid-liquid interface  

NASA Astrophysics Data System (ADS)

In this paper, we propose optical luminescence as a method for the evaluation of the kinetics of adsorption processes to calculate the time required to achieve the dynamic balance of the thin layers formed at the mineral-xanthate solution interface. The method is based on the measurement of the intensity for the integral optical radiation obtained from the mineral-xanthate thin layer, which is stimulated with a monochromatic pulsating optical signal, as a function of time. The luminescence was studied for the galena, sphalerite and chalcopyrite minerals with sodium amyl and sodium isobutyl xanthates, for different concentrations of the solutions and different pH values under constant temperature. Using the said method, information was gained on the kinetics of the adsorption of xanthates. Good correlation with the sequential (radiometric) investigation methods was noticed. A better measurement of the time to achieve equilibrium in the formation of the adsorption layer was also obtained.

Todoran, R.; Todoran, D.; Szakcs, Zs

2013-11-01

383

Arsenic from Groundwater to Paddy Fields in Bangladesh: SolidLiquid Partition, Sorption and Mobility  

Microsoft Academic Search

The arsenic contamination of Bangladesh groundwater involves heavy arsenic inputs to irrigated rice fields. Beside adsorption\\u000a on soil colloids, ironarsenic co-precipitation phenomena can affect arsenic retention in soils. In paddy fields of Satkhira\\u000a District, Bangladesh, the study of the arsenic and iron forms in the irrigation waters and in soils at different times and\\u000a distances from the irrigation well evidenced

Maria Martin; Rakiba Ferdousi; K. M. Jakeer Hossain; Elisabetta Barberis

2010-01-01

384

Alkylation of Imidazole by Solid-Liquid Phase Transfer Catalysis in the Absence of Solvent  

Microsoft Academic Search

Phase Transfer Catalysis in the absence of solvent is described as a useful and general method for the selective N-alkylation of imidazole. In all cases high yields are obtained while quaternization is avoided.

E. Dez-Barra; A. de la Hoz; A. Snchez-Migalln; J. Tejeda

1993-01-01

385

Noise influence on solid-liquid transition of ultrathin lubricant film  

NASA Astrophysics Data System (ADS)

The melting of ultrathin lubricant film by friction between atomically flat surfaces is studied. The additive noises of the elastic shear stress and strain, and the temperature are introduced for building the phase diagrams with the domains of sliding, stick-slip, and dry friction. It is shown that increase of the strain noise intensity causes the lubricant film melting even at low temperatures of the friction surfaces.

Khomenko, Alexei V.

2004-08-01

386

Direct calculation of the solid-liquid Gibbs free energy difference in a single equilibrium simulation  

NASA Astrophysics Data System (ADS)

Computing phase diagrams of model systems is an essential part of computational condensed matter physics. In this paper, we discuss in detail the interface pinning (IP) method for calculation of the Gibbs free energy difference between a solid and a liquid. This is done in a single equilibrium simulation by applying a harmonic field that biases the system towards two-phase configurations. The Gibbs free energy difference between the phases is determined from the average force that the applied field exerts on the system. As a test system, we study the Lennard-Jones model. It is shown that the coexistence line can be computed efficiently to a high precision when the IP method is combined with the Newton-Raphson method for finding roots. Statistical and systematic errors are investigated. Advantages and drawbacks of the IP method are discussed. The high pressure part of the temperature-density coexistence region is outlined by isomorphs.

Pedersen, Ulf R.

2013-09-01

387

Direct calculation of the solid-liquid Gibbs free energy difference in a single equilibrium simulation.  

PubMed

Computing phase diagrams of model systems is an essential part of computational condensed matter physics. In this paper, we discuss in detail the interface pinning (IP) method for calculation of the Gibbs free energy difference between a solid and a liquid. This is done in a single equilibrium simulation by applying a harmonic field that biases the system towards two-phase configurations. The Gibbs free energy difference between the phases is determined from the average force that the applied field exerts on the system. As a test system, we study the Lennard-Jones model. It is shown that the coexistence line can be computed efficiently to a high precision when the IP method is combined with the Newton-Raphson method for finding roots. Statistical and systematic errors are investigated. Advantages and drawbacks of the IP method are discussed. The high pressure part of the temperature-density coexistence region is outlined by isomorphs. PMID:24050323

Pedersen, Ulf R

2013-09-14

388

Investigating the Solid-Liquid Phase Transition of Water Nanofilms Using the Generalized Replica Exchange Method  

E-print Network

be calculated as in Eq. (7) and (8). As shown in Fig. 3 (a), the internal energy increases with temperature mono- tonically across the phase transition region, as a result of reweighting gREM derived caloric curve into the canonical ensemble. The heat capacity...

Lu, Qing; Kim, Jaegil; Farrell, James D.; Wales, David J.; Straub, John E.

2014-01-01

389

Solid-liquid equilibria for binary mixtures composed of acenaphthene, dibenzofuran, fluorene, phenanthrene, and diphenylmethane  

Microsoft Academic Search

The liquidus lines were determined with a solid-disappearance method for binary mixtures composed of acenaphthene, dibenzofuran, fluorene, phenanthrene, and diphenylmethane. While the first four substances are model compounds of wash oil, which has widely been used as a solvent to remove aromatics from coal oven gas, diphenylmethane is a high-boiling and low-melting compound that is a potential additive to modify

Ming-Jer Lee; Chang-Hsin Chen; Ho-mu Lin

1999-01-01

390

Perturbation theory of solid-liquid interfacial free energies of bcc metals  

SciTech Connect

We present an experimental and numerical study of the transmission of a photonic crystal perforated by two subwavelength slits, separated by two wavelengths.The experimental near-field image of the double-slit design of the photonic crystal shows an interference pattern, which is analogous to Youngs experiment. This interference arises as a consequence of the excitation of surface states of the photonic crystals and agrees very well with the simulations.

Zhang, Lei; Koschny, Thomas; Soukoulis, Costas M.

2012-01-18

391

Use of sol-gel systems for solid/liquid separation.  

SciTech Connect

A unique approach using sol-gel technology is presented for separating and recovering particulates and colloids from caustic waste slurries. The approach involves the addition of an alkali silicate and an organic gelling agent directly to the waste stream to immobilize particulates that range from macro sizes to submicron colloids. The particulates and colloids become trapped within a silica network that remains porous during the early stages of the sol-gel process. The freshly gelled monolith undergoes a process of syneresis, whereby the water and soluble salts are ejected from the monolith as it contracts. The approach has been illustrated by removal of ultrafine particulates from a Hanford Tank Waste simulant. Initial laboratory tests have shown that it is possible to produce silica monoliths in the presence of 4 M hydroxide. Analysis of the mother liquor produced during syneresis indicated quantitative recovery of the particulates within the monolith. The partitioning of ions between the silica gel and the mother liquor during syneresis correlates directly with the lyotropic series. Salt recoveries from the mother liquor in excess of 90% can be achieved. With a capability of recovering >99.999% of all particulates, including colloids, the process is more efficient than membrane filtration. This approach produces a rock-hard silica monolith that can be used directly as a feedstock to a glass melter or can be consolidated to near theoretical density by sintering.

Chaiko, D. J.; Kopasz, J. P.; Elison, A. J. G.; Chemical Engineering

1998-01-01

392

Microstructural Changes in Brazing Sheet due to Solid-Liquid Interaction  

Microsoft Academic Search

Aluminium brazing sheet is the material of choice to produce automotive heat exchangers.\\u000aAlthough in Dutch the official translation of aluminium brazing sheet is aluminium hardsoldeerplaat the English name is used in the industry. Aluminium brazing sheet is basically a sandwich material and consists of an aluminium core alloy, typically an AA3XXX alloy (containing Mn) or an AA6XXX alloy (containing

A. J. Wittebrood

2009-01-01

393

Effect of thermosolutal convection on the solid-liquid interface in Pb-Au alloy  

NASA Technical Reports Server (NTRS)

Liquid-solid interface distortion in the region of primary dendrite tips has been investigated in directionally solidified Pb-8 wt pct Au alloy. The distortions are caused by thermosolutal convection despite choice of growth conditions which should have been thermally and solutally stabilizing. The convection produces clustering of primary dendrites on a plane perpendicular to the growth direction. It produces a mushy zone, where the primary dendrites do not protrude with a uniform length, across the specimen cross section, resulting in large macrosegregation in the transverse direction. However, little macrosegregation is observed along the growth direction. The mushy zone, with uneven dendrite lengths, forms in the beginning of directional solidification. Its shape and dendrite distribution do not show much change during subsequent solidification. Tip morphologies of primary dendrites, within the dendrite clusters, appear to follow the morphological stability relationship.

Tewari, S. N.; Chopra, M. A.

1990-01-01

394

Thermal modeling with solid/liquid phase change of the thermal energy storage experiment  

NASA Technical Reports Server (NTRS)

A thermal model which simulates combined conduction and phase change characteristics of thermal energy storage (TES) materials is presented. Both the model and results are presented for the purpose of benchmarking the conduction and phase change capabilities of recently developed and unvalidated microgravity TES computer programs. Specifically, operation of TES-1 is simulated. A two-dimensional SINDA85 model of the TES experiment in cylindrical coordinates was constructed. The phase change model accounts for latent heat stored in, or released from, a node undergoing melting and freezing.

Skarda, J. Raymond Lee

1991-01-01

395

Self-similar microstructural evolution of dendritic solid?liquid mixtures during coarsening  

SciTech Connect

The microstructural evolution of equiaxed dendritic Al-Cu microstructures of two different solid volume fractions (46% and 72%) during isothermal coarsening was studied. We found that the microstructures evolved self-similarly, both morphologically and topologically, while the inverse specific surface area increased as the cube root of time. The differences in scaled morphologies and topologies could be attributed to the difference in solid volume fraction, with the higher volume fraction sample exhibiting a more compact interface shape distribution and a smaller scaled genus.

Fife, J.L.; Voorhees, P.W.; (NWU)

2009-06-12

396

ADSORPTION OF SURFACTANTS AND POLYMERS AT THE SOLID-LIQUID INTERFACE. (R823301)  

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

397

Determination of diffusion controlled reaction rates at a solid/liquid interface using scanning electron microscopy.  

PubMed

A high-resolution method has been developed for the determination of localized values of interfacial reaction rate and mass transfer coefficient in aqueous solution. Scanning electron microscopy has been successfully applied to this problem through the measurement of electroplated film thickness formed under limiting current conditions. The method involves the calculation of local values of reaction rate via Faraday's laws and subsequent conversion of the data to absolute values of mass transfer coefficient. The technique has been verified in an undisturbed, turbulent flow regime (rotating cylinder electrode) through the use of Sherwood group dimensionless analysis. The resulting relationship shows comparable accuracy relative to electrochemical measurements. Favourable comparison has also been made with the generally accepted rotating cylinder correlation of Eisenberg, Tobias and Wilke. Differential rates of mass transfer to a single surface under conditions of disturbed flow have also been examined at a high spatial resolution using the stepped rotating cylinder electrode geometry. In this case, reaction rates have been measured as a function of circumferential distance within a recirculation zone situated immediately downstream of a backward-facing step. PMID:17535261

Kear, Gareth; Huang, Sheng-Huei; Bremhorst, Klaus; Purchase, Andrew

2007-06-01

398

Using Peltier Cells to Study Solid-Liquid-Vapour Transitions and Supercooling  

ERIC Educational Resources Information Center

We propose an apparatus for teaching experimental thermodynamics in undergraduate introductory courses, using thermoelectric modules and a real-time data acquisition system. The device may be made at low cost, still providing an easy approach to the investigation of liquid-solid and liquid-vapour phase transitions and of metastable states

Torzo, Giacomo; Soletta, Isabella; Branca, Mario

2007-01-01

399

Developments to a landfill processes model following its application to two landfill modelling challenges.  

PubMed

The landfill model LDAT simulates the transport and bio-chemical behaviour of the solid, liquid and gas phases of waste contained in a landfill. LDAT was applied to the LMC1 and LMC2 landfill modelling challenges held in 2009 and 2011. These were blind modelling challenges with the model acting in a predictive mode based on limited early time sections of full datasets. The LMC1 challenge dataset was from a 0.34m deep 0.48m diameter laboratory test cell, and the LMC2 dataset was from a 55m80m 8m deep landfill test cell which formed part of the Dutch sustainable landfill research programme at Landgraaf in the Netherlands. The paper describes developments in LDAT arising directly from the experience of responding to the two challenges, and discusses the model input and output data obtained from a calibration using the full datasets. The developments include the modularisation of the model into a set of linked sub-models, the strategy for converting conventional waste characteristics into model input parameters, the identification of flexible degradation pathways to control the CO2:CH4 ratio, and the application of a chemical equilibrium model that includes a stage in which the solid waste components dissolve into the leachate. PMID:23318154

White, J K; Beaven, R P

2013-10-01

400

Advanced in situ spectroscopic techniques and their applications in environmental biogeochemistry: introduction to the special section.  

PubMed

Understanding the molecular-scale complexities and interplay of chemical and biological processes of contaminants at solid, liquid, and gas interfaces is a fundamental and crucial element to enhance our understanding of anthropogenic environmental impacts. The ability to describe the complexity of environmental biogeochemical reaction mechanisms relies on our analytical ability through the application and developmemnt of advanced spectroscopic techniques. Accompanying this introductory article are nine papers that either review advanced in situ spectroscopic methods or present original research utilizing these techniques. This collection of articles summarizes the challenges facing environmental biogeochemistry, highlights the recent advances and scientific gaps, and provides an outlook into future research that may benefit from the use of in situ spectroscopic approaches. The use of synchrotron-based techniques and other methods are discussed in detail, as is the importance to integrate multiple analytical approaches to confirm results of complementary procedures or to fill data gaps. We also argue that future direction in research will be driven, in addition to recent analytical developments, by emerging factors such as the need for risk assessment of new materials (i.e., nanotechnologies) and the realization that biogeochemical processes need to be investigated in situ under environmentally relevant conditions. PMID:21546653

Lombi, Enzo; Hettiarachchi, Ganga M; Scheckel, Kirk G

2011-01-01

401

Extension of the broadband single-mode integrated optical waveguide technique to the ultraviolet spectral region and its applications.  

PubMed

We report here the fabrication, characterization, and application of a single-mode integrated optical waveguide (IOW) spectrometer capable of acquiring optical absorbance spectra of surface-immobilized molecules in the visible and ultraviolet spectral region down to 315 nm. The UV-extension of the single-mode IOW technique to shorter wavelengths was made possible by our development of a low-loss single-mode dielectric waveguide in the UV region based on an alumina film grown by atomic layer deposition (ALD) over a high quality fused silica substrate, and by our design/fabrication of a broadband waveguide coupler formed by an integrated diffraction grating combined with a highly anamorphic optical beam of large numerical aperture. As an application of the developed technology, we report here the surface adsorption process of bacteriochlorophyll a on different interfaces using its Soret absorption band centred at 370 nm. The effects of different chemical compositions at the solid-liquid interface on the adsorption and spectral properties of bacteriochlorophyll a were determined from the polarized UV-Vis IOW spectra acquired with the developed instrumentation. The spectral extension of the single-mode IOW technique into the ultraviolet region is an important advance as it enables extremely sensitive studies in key characteristics of surface molecular processes (e.g., protein unfolding and solvation of aromatic amino-acid groups under surface binding) whose spectral features are mainly located at wavelengths below the visible spectrum. PMID:24466569

Wiederkehr, Rodrigo S; Mendes, Sergio B

2014-03-21

402

Lecture multi-thorique de la priode de transition aux normes IAS\\/IFRS : une analyse lexicale de la communication financire  

Microsoft Academic Search

La premire application des normes comptables internationales IAS\\/IFRS a suscit une communication financire particulirement abondante. Conscients de l'exceptionnalit de cette situation, nous avons recens tous les communiqus de presse relatifs la premire application des nouvelles normes comptables pour les groupes du SBF 120. Nous nous sommes interrogs sur l'existence de notions issues de la thorie positive de la comptabilit,

Samira Demaria

2007-01-01

403

Application of a new Raman microprobe spectrometer to nondestructive analysis of sulfate and other ions in individual phases in fluid inclusions in minerals  

USGS Publications Warehouse

Rosasco et al. (1975), reported the first successful application of laser-excited Raman spectroscopy for the identification and nondestructive partial analysis of individual solid, liquid, and gaseous phases in selected fluid inclusions. We report here the results of the application of a new instrument, based on back-scattering, that eliminates many of the previous stringent sample limitations and hence greatly expands the range of applicability of Raman spectroscopy to fluid inclusions. Fluid inclusions in many porphyry copper deposits contain 5-10 ??m 'daughter' crystals thought to be anhydrite but too small for identification by the previous Raman technique. Using the new instrument, we have verified that such daughter crystals in quartz from Bingham, Utah, are anhydrite. They may form by leakage of hydrogen causing internal autooxidation of sulfide ion. Daughter crystals were also examined in apatite (Durango, Mexico) and emerald (Muzo, Colombia). Valid analyses of sulfur species in solution in small fluid inclusions from ore deposits would be valuable, but are generally impossible by conventional methods. We present a calibration procedure for analyses for SO42- in such inclusions from Bingham, Utah (12,000 ?? 4000 ppm) and Creede, Colo. (probably < 500 ppm). A fetid Brazilian quartz, originally thought to contain liquid H2S, is shown to contain only HS- in major amounts. ?? 1979.

Rosasco, G.J.; Roedder, E.

1979-01-01

404

Applicability of alkali activated slag-seeded Egyptian Sinai kaolin for the immobilization of 60Co radionuclide  

NASA Astrophysics Data System (ADS)

The present work was established to determine the applicability of local Egyptian kaolinite and blast furnace slag (BFS) as raw materials toward the synthesis of geopolymers and subsequent immobilization of cobalt-60, which is one of the most abundant radionuclides generated in radioactive waste streams in Egypt. XRF, XRD, FT-IR, and SEM techniques were used to characterize the local raw materials and their corresponding alkali activated products. Metakaolin (MK) was obtained by thermal treatment of Egyptian Sinai kaolin 750 C/4 h. MK and five different BFS content (5, 10, 30, 50 and 80%) were used to synthesize geopolymeric matrices using an alkaline activator of Si-modulus = 1.35 at solid/liquid ratios of 0.8. Compressive strength tests were performed indicating that 50% BFS addition gave the highest values of compressive strength. The IAEA standard leaching tests of cobalt-60 from the solidified waste matrices were carried out. The effective diffusion coefficients of cobalt-60 radionuclides from the solidified waste matrices were calculated to be in the order of 10-14 cm2/s. Leaching of radionuclides was examined to be controlled by the wash-off mechanism with very acceptable values. These results gave encouragement that the tested Egyptian raw materials can be conveniently applied for the synthesis of geopolymers that can be used as a low-cost and high-efficiency materials for the immobilization of radioactive waste.

El-Naggar, M. R.

2014-04-01

405

In situ SHINERS at electrochemical single-crystal electrode/electrolyte interfaces: tuning preparation strategies and selected applications.  

PubMed

We have studied Au(55 nm)@SiO2 nanoparticles (NPs) on two low-index phases of gold and platinum single crystal electrodes in ClO4(-) and SO4(2-) ion-containing electrolytes by both electrochemical methods and in-situ shell-isolated nanoparticle enhanced Raman spectroscopy (SHINERS). We showed the blocking of the electrode with surfactants originating from the synthesis of as-prepared SHINERS NPs. We introduce an efficient procedure to overcome this problem, which provides a fundamental platform for the application of SHINERS in surface electrochemistry and beyond. Our method is based on a hydrogen evolution treatment of the SHINERS-NP-modified single-crystal surfaces. The reliability of our preparation strategy is demonstrated in electrochemical SHINERS experiments on the potential-controlled adsorption and phase formation of pyridine on Au(hkl) and Pt(hkl). We obtained high-quality Raman spectra on these well-defined and structurally carefully characterized single-crystal surfaces. The analysis of the characteristic A1 vibrational modes revealed perfect agreement with the interpretation of single-crystal voltammetric and chronoamperometric experiments. Our study demonstrates that the SHINERS protocol developed in this work qualifies this Raman method as a pioneering approach with unique opportunities for in situ structure and reactivity studies at well-defined electrochemical solid/liquid interfaces. PMID:24007327

Li, Jian-Feng; Rudnev, Alexander; Fu, Yongchun; Bodappa, Nataraju; Wandlowski, Thomas

2013-10-22

406

Remote sensing in environmental police investigations: aerial platforms and an innovative application of thermography to detect several illegal activities.  

PubMed

Being able to identify the environmental crimes and the guilty parties is central to police investigations, and new technologies enable the authorities to do this faster and more accurately than ever before. In recent years, our research team has introduced the use of a range of aerial platforms and an innovative application of thermography to detect several illegal activities; for example, illegal sanitary sewer and storm-drain connections, illicit wastewater discharges, and other "anomalies" on surface waters can be easily identified using their thermal infrared signatures. It can also be used to detect illegal solid/liquid waste dumps or illicit air discharges. This paper introduces first results of a Thermal Pattern and Thermal Tracking approach that can be used to identify different phenomena and several pollutants. The aims of this paper were to introduce a fingerprint paradigm for environmental police investigations, defining several specific signatures (patterns) that permit the identification of an illicit/anomalous activity, and establish a procedure to use this information to find the correlation (tracking) between the crime and the culprit or the source and the target. PMID:25154683

Lega, M; Ferrara, C; Persechino, G; Bishop, P

2014-12-01

407

Applicant # _____________ NEW APPLICANT  

E-print Network

in the record, b) the release of such information in response to a court order, health or safety emergency leadership, academic, and/or personal achievements. Explain how they are applicable to the TSC Governing # _____________ California State University, Fullerton Voluntary Authorization for Educational Record Disclosure University

de Lijser, Peter

408

Fluorescence cross-correlation analyses of the molecular interaction between an Aux/IAA protein, MSG2/IAA19, and protein-protein interaction domains of auxin response factors of arabidopsis expressed in HeLa cells.  

PubMed

Since auxin may elicit numerous developmental responses by the use of a combination of auxin response factors (ARFs) and their Aux/IAA repressors, it is important to determine the interaction between the two protein families in a quantitative manner. We transiently expressed the C-terminal protein-protein interaction domains (CTDs) of Arabidopsis ARFs, MP/ARF5 and NPH4/ARF7, and MSG2/IAA19, fused to fluorescent proteins in HeLa cells, and determined their molecular interactions with fluorescence cross-correlation spectroscopy (FCCS). Almost complete association was found between MSG2 and MP-CTD and between MSG2 and NPH4-CTD. Approximately 20% association was found for MSG2 homodimers, NPH4-CTD homodimers and MP-CTD/NPH4-CTD heterodimers. Homotypic binding of MP-CTD may be weaker than that of MSG2. MSG2 was localized in cytoplasmic compartments in HeLa cells, whereas it was localized in the nuclei in plant cells. The fact that the heterotypic interaction between MSG2 and ARF-CTDs is stronger than each of the homotypic interactions appears to be the molecular basis for tight control of the transcriptional activity of ARFs by auxin. These results also show that FCCS is useful to examine protein-protein interactions especially for transcriptional regulators. PMID:16854942

Muto, Hideki; Nagao, Issei; Demura, Taku; Fukuda, Hiroo; Kinjo, Masataka; Yamamoto, Kotaro T

2006-08-01

409

Teeth and bones: applications of surface science to dental materials and related biomaterials  

NASA Astrophysics Data System (ADS)

Recent years have seen a considerable upsurge in publications concerning the surface structure and chemistry of materials with biological or biomedical applications. Within the body, gas-solid interactions become relatively less significant and solid-liquid or solid-solid interfaces dominate, providing new challenges for the surface scientist. The current paper aims to provide a timely review of the use of surface analysis and modification techniques within the biomaterials field. A broad overview of applications in a number of related areas is given with particular attention focusing on those materials commonly encountered in dentistry and oral or maxillofacial implantology. Several specific issues of current interest are discussed. The interaction between synthetic and natural solids, both in the oral environment and elsewhere in the body is important in terms of adhesion, related stresses and strains and ultimately the longevity of a dental restoration, biomedical implant, or indeed the surrounding tissue. Exposure to body fluids, of course, can also affect stability, leading to the degradation or corrosion of materials within the body. Whilst this could potentially be harmful, e.g., if cytotoxic elements are released, it may alternatively provide a route to the preferential release of beneficial substances. Furthermore, in some cases, the controlled disintegration of a biomaterial is desirable, allowing the removal of an implant, e.g., without the need for further surgery. The presence of cells in the immediate bioenvironment additionally complicates the situation. A considerable amount of current research activity is targeted at the development of coatings or surface treatments to encourage tissue growth. If this is to be achieved by stimulating enhanced cell productivity, determination of the relationship between cell function and surface composition is essential.

Jones, F. H.

2001-05-01

410

Applications and Properties of Ionic Liquid- Based Gels and Soft Solid Composites  

NASA Astrophysics Data System (ADS)

Solid-liquid composites (gels) have a combination of properties that afford new material applications in which high solute diffusion is desirable. These composites have a soft-solid mechanical integrity and will not flow under gravity, but entrain a liquid matrix (i.e. 60-98 mass %) which allows for high diffusion and high reactivity. Room temperature ionic liquid (RTILs) are molten organic salts with a melting point below room temperature and negligible vapor pressure. If the RTILs are used as the liquid component of a gel, then the gel matrix will not evaporate (unlike other organic solvents) and may be used for long term applications. This thesis research applies RTIL gels for two new applications; carbon dioxide/nitrogen separation and chemical warfare agent (CWA) barrier and decontamination. Separating CO2 from the flue gas of coal and gas fired power-plants is an increasingly economically and environmentally important gas separation. In this first study, RTIL gels are cast in a supported membrane and gas permeability and ideal selectivity are measured. The RTIL matrix has an inherent affinity for CO2 and provides a high diffusion, hence high permeability (i.e. 500-700 barrer). The solidifying component is a low molecular-weight organic gelator (LMOG) which through physical bonding interactions (i.e. hydrogen bonding, pi-pi stacking and van der Walls forces) forms an entangled network which provides mechanical stability (i.e. increase trans-membrane pressure required to expel selective material from the support). In these studies two LMOGs and five RTILs are used to make supported gel membranes and determine gas permeability and temperature dependent trends. The second application for RTIL gels is a decontaminating barrier for CWAs and toxic industrial compounds (TICs). In these studies a layer of RTIL gel is applied on top of a substrate contaminated with a CWA simulant (i.e. chloroethylethylsulfide, CEES). The gel performs well as a barrier, preventing CEES vapor from penetrating the gel. Simultaneously, the RTIL gel actively decontaminated the substrate by reacting CEES with a sacrificial amine. The RTIL gel barrier was able to decontaminate up to 98% of the CEES applied to a painted steel substrate. Two gel barriers are tested: (1) RTIL gel with a LMOG solidifying agent, and (2) RTIL gel with a polymeric cross-linked network solidifying agent. The polymer gel provided a more mechanically robust barrier, however, the LMOG gel decontaminated at a faster rate. These new applications are but two of many possible applications for RTIL gels. Their negligible vapor pressure affords long term application in ambient conditions and their unique chemistry allows them to be tailored for specific applications.

Voss, Bret Alan McGinness

411

Les recommandations de prise en charge des complications m?taboliques associ?es aux antipsychotiques de deuxi?me g?n?ration chez les enfants et les adolescents  

PubMed Central

HISTORIQUE : Les antipsychotiques de deuxime gnration sassocient souvent des complications mtaboliques. Ces mdicaments sont utiliss plus souvent pour le traitement des troubles de sant mentale chez les enfants, ce qui a requis llaboration de lignes directrices officielles sur la surveillance de leur innocuit et de leur efficacit. Des lignes directrices ont dj t labores pour surveiller les complications mtaboliques et neurologiques. Afin daider les praticiens qui effectuent ces interventions de surveillance, une srie de recommandations thrapeutiques complmentaires a t labore pour les cas o lon observe des mesures ou des rsultats anormaux. OBJECTIF : Crer des recommandations probantes afin de contribuer la prise en charge des complications mtaboliques chez les enfants traits au moyen dantipsychotiques de deuxime gnration. MTHODOLOGIE : Les auteurs ont procd une analyse systmatique des publications sur les complications mtaboliques des antipsychotiques de deuxime gnration chez les enfants. Les membres du groupe consensuel ont valu linformation recueillie grce lanalyse bibliographique systmatique et ont fait appel un processus de groupe nominal pour parvenir un consensus lgard de recommandations thrapeutiques. Dans la mesure du possible, ils se sont reports aux lignes directrices existantes sur lvaluation et le traitement des anomalies mtaboliques chez les enfants. RSULTATS : Des recommandations probantes sont prsentes pour contribuer la prise en charge des complications mtaboliques, y compris la prise de poids, laugmentation du tour de taille, llvation des taux de prolactine, de cholestrol, de triglycrides et de glucose, les preuves de fonction hpatique anormales et les tudes thyrodiennes anormales. CONCLUSION : Il faut recourir des mesures de surveillance convenables lorsquon prescrit des antipsychotiques de deuxime gnration. Les prsentes lignes directrices thrapeutiques orientent les cliniciens quant la prise en charge clinique des complications mtaboliques lorsquelles se produisent. PMID:24082815

Ho, Josephine; Panagiotopoulos, Constadina; McCrindle, Brian; Grisaru, Silviu; Pringsheim, Tamara

2012-01-01

412

Thermoelectric Properties of Au- Containing Type-I Clathrates Ba8AuxGa16-3xGe30+2x  

SciTech Connect

Type I clathrates, with compositions based on Ba8Ga16Ge30, are a class of promising thermoelectric materials due to their intrinsically low thermal conductivity. It has been demonstrated previously that the thermoelectric performance can be improved by transition metal substitution of the framework atoms. In this study, the effects of Au substitution for Ga/Ge on thermal and electrical transport properties of type I clathrate compounds have been investigated. Polycrystalline samples with a large range of Au content have been synthesized using conventional solid state techniques with the actual compositions of resulting materials approximately following Zintl-Klemm rules. The charge carrier type changes from electrons (n) to holes (p) as the Au content increases. The Seebeck coefficient (S) and power factor (S2/ where is the electrical resistivity) were improved by Au substitution and the resulting overall thermoelectric properties were enhanced by Au substitution with a thermoelectric figure of merit ZT ~ 0.63 at temperature T = 740 K for the composition Ba8Au5.47Ge39.96. The results presented herein show that Au-containing type I clathrates are promising p-type thermoelectric materials for high temperature applications.

Ye, Zuxin [Optimal Inc., Plymouth, Michigan 48170, USA] [Optimal Inc., Plymouth, Michigan 48170, USA; Cho, Jung Young [Optimal Inc., Plymouth, Michigan 48170, USA] [Optimal Inc., Plymouth, Michigan 48170, USA; Tessema, Misle M. [Optimal Inc., Plymouth, Michigan 48170, USA] [Optimal Inc., Plymouth, Michigan 48170, USA; Salvador, James R. [General Motors, Global Research and Development] [General Motors, Global Research and Development; Waldo, Richard A. [General Motors, Global Research and Development] [General Motors, Global Research and Development; Yang, Jihui [University of Washington] [University of Washington; Wang, Hsin [ORNL] [ORNL; Cai, Wei [ORNL] [ORNL; Kirkham, Melanie J [ORNL] [ORNL; Yang, Jiong [Chinese Academy of Sciences (CAS)] [Chinese Academy of Sciences (CAS); Zhang, Wenqing [Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS)] [Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS)

2014-01-01

413

Cationic surfactant-based polyfluorate salts: phase separation and analytical applications in the extraction and preconcentration of ionic species prior to liquid chromatography.  

PubMed

The liquid-solid phase separation originating from the formation of cationic surfactant-based polyfluorate salts (CSBPS) has been explored for extracting and preconcentrating ionic species. Two cationic surfactants were tested; one with aliphatic hydrocarbon tail [Cetyltrimethylammonium bromide (CTAB)]and the other containing a heterocyclic ring [Hexadecylpyridinium bromide (HPyBr)]. Phase separation possibility was investigated with the use of hexafluorophosphates (PF6-) and tetrafluoroborates (BF4-). The effect of added acid, base and salt on the phase separation and analyte extraction was also investigated. In all cases the obtained phase diagrams consisted of two regions: a homogeneous liquid region and a solid-liquid region. Analytes of hydrophilic and hydrophobic nature such as amines, amino acids and organic chromophores were used as test compounds in both their anionic and cationic forms. The respective recoveries ranged from over 90% for anionic species and in the proximity of 50% for cationic species, remaining below 20% for neutral species. Extracts from alkaline aqueous and plasma samples spiked with tyrosine and phenylalanine were also subjected to HPLC separation with UV detection with satisfactory results. On line application was also enabled using a flow through-solid phase extraction-HPLC hyphenated apparatus, thus adding the element of automatization and increased reproducibility. PMID:15794550

Paleologos, Evangelos K

2005-02-25

414

Influence of hydro-climatic conditions, soil type, and application matrix on potential vadose zone export of PPCPs  

NASA Astrophysics Data System (ADS)

The land-application of biosolids and animal manure to agricultural fields has the potential to negatively impact the quality of nearby surface and subsurface water due to the presence of emerging contaminants in these residuals. We investigated the extent to which the vadose zone acts as a hydrologic and biogeochemical filter of two emerging contaminants, Triclosan (TCS) and estrone (E1) using a coupled source zone and vadose zone modeling approach. Monte Carlo simulations were run for a year following residual applications to explore the following research questions: (1) how does the application matrix (e.g., de-watered solids, liquid lagoon effluent, etc.) affect PPCP mass fluxes?; (2) how do hydro-climatic conditions and soil type affect PPCP mass fluxes?; (3) what role does the presence of macropore pathways play in PPCP export from the vadose zone; and (4) does the long-term, repeated application of residuals affect the ability of the vadose zone to act as an effective biogeochemical filter? The simulations were conducted for a sub-tropical climate with sand (e.g., Florida) and a humid climate with a silty clay loam (e.g., Midwestern United States). Simulation results suggest that the potential mobility of emerging contaminants increases linearly with increasing fraction applied to the mobile phase of the source zone (i.e., higher PPCP mass fraction in the dissolved phase during application). Following a single application, the total amount of PPCP mass exported from the source zone over the course of a year can be as high as 70% in a sub-tropical climate with sand soil. However, these types of soils do not have macropore flow pathways and the annual PPCP mass exported from the vadose zone is less than 1% of the mass applied. The higher organic carbon content in a silty clay loam reduces the amount of PPCP mass released from the source zone to less than 5% of the mass applied. In the presence of macropore pathways, the silty clay loam's vadose zone acts as a less effective biogeochemical filter than the sand's vadose zone. However, following a single application, Monte Carlo simulations suggest that the annual mass exported from the silty clay loam's vadose zone is less than 0.2% of the applied mass. Additionally, simulation results suggest that the mass exported from the vadose zone of the silty clay loam increases with time when fields receive long-term, repeated residual applications. Thus, field studies conducted with single applications likely underestimate mass fluxes exported from fields with a history of applications.

Gall, H. E.; Rao, P.; O'Connor, G.

2013-12-01

415

Phase transfer catalysis: some recent applications in organic synthesis  

Microsoft Academic Search

A survey dealing with the use of anhydrous potassium carbonate as an efficient base for promoting organic reactions under solidliquid phase transfer catalysis (SL-PTC) conditions is reported. In particular, the generation in situ of trifluoro- and trichloroacetamidide, and reactions of these azaanions with 2-bromocarboxylic esters and epoxides, affording protected ?-amino acids and ?-amido alcohols, respectively, are described. The reduction of

Domenico Albanese; Dario Landini; Angelamaria Maia; Michele Penso

1999-01-01

416

SIPAD-NG: a generic system for accessing scientific data - Application to oceanography products  

NASA Astrophysics Data System (ADS)

SIPAD-NG ("Systme d'Information, de Prservation et d'Accs aux Donnes - Nouvelle Gnration" - "Information System for Data Preservation and Access - New Generation") is a generic software system allowing web consultation of scientific data catalogs and access to these data. SIPAD-NG is an "on the shelf" software that can be used by Data Centres from any scientific domain. Currently, SIPAD-NG is operational for accessing data from CNES/CNRS Plasma Physics Data Centre, Mercator-Ocean and soon for CNES altimetry products and CNES/IFREMER SMOS products. The SIPAD-NG kernel is composed of "basic services" that offer the standard functions of a data management system: mechanisms for searching for relevant data, data selection and ordering, long-term archiving, etc These "basic services" provide interfaces that allow various types of "client applications" to use them: web servers, science processing software, remote applications, etc This architecture provides Data Centres with a software system that can be adapted to their needs and enhanced over time by: metadata catalog parameterization, customisation of the web server, adding of client applications and specific software. We describe SIPAD-NG characteristics in terms of functionalities, architectural design and technological choices. An example of instantiation for Oceanography applications (Mercator-Ocean and altimetry) is detailed.

Pottier, C.; Heulet, D.

2009-04-01

417

A new class of room temperature molten salts for battery applications  

Microsoft Academic Search

Salts that are liquid at room temperature would provide a completely ionic electrolyte for rechargeable batteries without the penalty of high operating temperatures. We have discovered and characterized a new class of molten salts that are liquids considerably below room temperature. The new materials are mixtures of dialkyimidazolium chlorides and aluminum chloride. The solid-liquid phase diagram of one member of

J. S. Wilkes; J. A. Levisky; J. S. Landers; R. L. Vaughn; C. L. Hussey; D. A. Floreani; D. J. Stech

1981-01-01

418

The application of Cold Atmospheric Plasma (CAP) for the sterilisation of spacecraft materials  

NASA Astrophysics Data System (ADS)

Plasma, oft called the fourth state of matter after solid, liquid and gas, is defined by its ionized state. Ionization can be induced by different means, such as a strong electromagnetic field applied with a microwave generator. The concentration and composition of reactive atoms and molecules produced in Cold Atmospheric Plasma (CAP) depends on the gases used, the gas flow, the power applied, the humidity level etc.. In medicine, low-temperature plasma is already used for the sterilization of surgical instruments, implants and packaging materials as plasma works at the atomic level and is able to reach all surfaces, even the interior of small hollow items like needles. Its ability to sterilise is due to the generation of biologically active bactericidal agents, such as free radicals and UV radiation. In the project PLASMA-DECON (DLR/BMWi support code 50JR1005) a prototype of a device for sterilising spacecraft material and components was built based on the surface micro-discharge (SMD) plasma technology. The produced plasma species are directed into a closed chamber which contains the parts that need to be sterilised. To test the inactivation efficiency of this new device bacterial spores were used as model organisms because in the COSPAR Planetary Protection Policy all bioburden constraints are defined with respect to the number of spores (and other heat-tolerant aerobic microorganisms). Spores from different Bacillus species and strains, i.e. wildtype strains from culture collections and isolates from spacecraft assembly cleanrooms, were dried on three different spacecraft relevant materials and exposed to CAP. The specificity, linearity, precision, and effective range of the device was investigated. From the results obtained it can be concluded that the application of CAP proved to be a suitable method for bioburden reduction / sterilisation in the frame of planetary protection measures and the design of a larger plasma device is planned in the future.

Rettberg, Petra; Barczyk, Simon; Morfill, Gregor; Thomas, Hubertus; Satoshi Shimizu, .; Shimizu, Tetsuji; Klaempfl, Tobias

2012-07-01

419

TESTING OF A ROTARY MICROFILTER TO SUPPORT HANFORD APPLICATIONS  

SciTech Connect

Savannah River National Laboratory (SRNL) researchers are investigating and developing a rotary microfilter for solid-liquid separation applications at the Savannah River Site (SRS). Because of the success of that work, the Hanford Site is evaluating the use of the rotary microfilter for its Supplemental Pretreatment process. The authors performed rotary filter testing with a full-scale, 25-disk unit with 0.5 {micro} filter media manufactured by Pall Corporation using a Hanford AN-105 simulant at solids loadings of 0.06, 0.29, and 1.29 wt%. The conclusions from this testing are: (1) The filter flux at 0.06 wt% solids reached a near constant value at an average of 0.26 gpm/ft{sup 2} (6.25 gpm total). (2) The filter flux at 0.29 wt% solids reached a near constant value at an average of 0.17 gpm/ft{sup 2} (4 gpm total). (3) The filter flux at 1.29 wt% solids reached a near constant value at an average of 0.10 gpm/ft{sup 2} (2.4 gpm total). (4) Because of differences in solids loadings, a direct comparison between crossflow filter flux and rotary filter flux is not possible. The data show the rotary filter produces a higher flux than the crossflow filter, but the improvement is not as large as seen in previous testing. (5) Filtrate turbidity measured < 4 NTU in all samples collected. (6) During production, the filter should be rinsed with filtrate or dilute caustic and drained prior to an extended shutdown to prevent the formation of a layer of settled solids on top of the filter disks. (7) Inspection of the seal faces after {approx} 140 hours of operation showed an expected amount of initial wear, no passing of process fluid through the seal faces, and very little change in the air channeling grooves on the stationary face. (8) Some polishing was observed at the bottom of the shaft bushing. The authors recommend improving the shaft bushing by holding it in place with a locking ring and incorporated grooves to provide additional cooling. (9) The authors recommend that CH2MHill Hanford test other pore size media to determine the optimum pore size for Hanford waste.

Poirier, M; David Herman, D; David Stefanko, D; Samuel Fink, S

2008-06-26

420

Les recommandations th?rapeutiques relatives aux effets secondaires extrapyramidaux associ?s ? l'utilisation d'antipsychotiques de deuxi?me g?n?ration chez les enfants et les adolescents  

PubMed Central

HISTORIQUE ET OBJECTIF : Lutilisation dantipsychotiques augmente chez les enfants. Le prsent article visait orienter les cliniciens quant la prise en charge clinique des effets secondaires extrapyramidaux des antipsychotiques de deuxime gnration. MTHODOLOGIE : Les publications, les entrevues avec des informateurs cls et des changes avec les membres dun groupe de discussion et les partenaires ont permis de dterminer les principaux secteurs cliniques dorientation et les prfrences quant la structure des prsentes recommandations. Les membres responsables des lignes directrices ont reu le projet de recommandations, ont valu linformation recueillie grce une analyse bibliographique systmatique et ont utilis un processus de groupe nominal pour parvenir un consensus quant aux recommandations thrapeutiques. Les lignes directrices contiennent une description des anomalies neurologiques souvent observes avec lutilisation dantipsychotiques ainsi que les recommandations sur le moyen dexaminer et de quantifier ces anomalies. Une dmarche squentielle sur la prise en charge des anomalies neurologiques est prsente. RSULTATS : On peut observer plusieurs types de symptmes extrapyramidaux attribuables lutilisation dantipsychotiques chez les enfants, y compris la dystonie aigu, lakathisie, le parkinsonisme et la dyskinsie tardive, toutes induites par les neuroleptiques, de mme que la dystonie tardive, lakathisie tardive et les dyskinsies de sevrage. La forte majorit des donnes probantes sur le traitement des troubles du mouvement induits par les antipsychotiques proviennent de patients adultes atteints de schizophrnie. tant donn le peu de donnes pdiatriques, les recommandations dcoulent de publications portant tant sur des adultes que sur des enfants. Compte tenu des limites de gnralisation des donnes provenant de sujets adultes pour des enfants, il faudrait valuer ces recommandations daprs les avis dexperts plutt que daprs les donnes probantes. CONCLUSION : Les cliniciens doivent savoir que les antipsychotiques de deuxime gnration ont le potentiel dinduire des effets secondaires neurologiques et devraient faire preuve dune extrme vigilance lorsquils en prescrivent. PMID:24082814

Pringsheim, Tamara; Doja, Asif; Belanger, Stacey; Patten, Scott

2012-01-01

421

Microgravity Science and Applications: Program Tasks and Bibliography for Fiscal Year 1996  

NASA Technical Reports Server (NTRS)

NASA's Microgravity Science and Applications Division (MSAD) sponsors a program that expands the use of space as a laboratory for the study of important physical, chemical, and biochemical processes. The primary objective of the program is to broaden the value and capabilities of human presence in space by exploiting the unique characteristics of the space environment for research. However, since flight opportunities are rare and flight research development is expensive, a vigorous ground-based research program, from which only the best experiments evolve, is critical to the continuing strength of the program. The microgravity environment affords unique characteristics that allow the investigation of phenomena and processes that are difficult or impossible to study an Earth. The ability to control gravitational effects such as buoyancy driven convection, sedimentation, and hydrostatic pressures make it possible to isolate phenomena and make measurements that have significantly greater accuracy than can be achieved in normal gravity. Space flight gives scientists the opportunity to study the fundamental states of physical matter-solids, liquids and gasses-and the forces that affect those states. Because the orbital environment allows the treatment of gravity as a variable, research in microgravity leads to a greater fundamental understanding of the influence of gravity on the world around us. With appropriate emphasis, the results of space experiments lead to both knowledge and technological advances that have direct applications on Earth. Microgravity research also provides the practical knowledge essential to the development of future space systems. The Office of Life and Microgravity Sciences and Applications (OLMSA) is responsible for planning and executing research stimulated by the Agency's broad scientific goals. OLMSA's Microgravity Science and Applications Division (MSAD) is responsible for guiding and focusing a comprehensive program, and currently manages its research and development tasks through five major scientific areas: biotechnology, combustion science, fluid physics, fundamental physics, and materials science. FY 1996 was an important year for MSAD. NASA continued to build a solid research community for the coming space station era. During FY 1996, the NASA Microgravity Research Program continued investigations selected from the 1994 combustion science, fluid physics, and materials science NRAS. MSAD also released a NASA Research Announcement in microgravity biotechnology, with more than 130 proposals received in response. Selection of research for funding is expected in early 1997. The principal investigators chosen from these NRAs will form the core of the MSAD research program at the beginning of the space station era. The third United States Microgravity Payload (USMP-3) and the Life and Microgravity Spacelab (LMS) missions yielded a wealth of microgravity data in FY 1996. The USMP-3 mission included a fluids facility and three solidification furnaces, each designed to examine a different type of crystal growth.

1997-01-01

422

TESTING SOLIDS SETTING APPARATUSES FOR DESIGN AND OPERATION OF WET-WEATHER FLOW SOLIDS-LIQUID SEPARATION PROCESSES  

EPA Science Inventory

This study was a side-by-side comparison of two settling evaluation methods: one traditional and one new. The project investigated whether these column tests were capable of capturing or representing the rapidly settling particles present in wet-weather flows (WWF). The report r...

423

BEHAVIOR OF SURFACTANT MIXTURES AT SOLID/LIQUID AND OIL/LIQUID INTERFACES IN CHEMICAL FLOODING SYSTEMS  

SciTech Connect

The aim of the project is to develop a knowledge base to help the design of enhanced processes for mobilizing and extracting untrapped oil. We emphasize evaluation of novel surfactant mixtures and obtaining optimum combinations of the surfactants for efficient chemical flooding EOR processes. In this regard, an understanding of the aggregate shape, size and structure is crucial since these properties govern the crude oil removal efficiency. During the three-year period, the adsorption and aggregation behavior of sugar-based surfactants and their mixtures with other types of surfactants have been studied. Sugar-based surfactants are made from renewable resources, nontoxic and biodegradable. They are miscible with water and oil. These environmentally benign surfactants feature high surface activity, good salinity, calcium and temperature tolerance, and unique adsorption behavior. They possess the characteristics required for oil flooding surfactants and have the potential for replacing currently used surfactants in oil recovery. A novel analytical ultracentrifugation technique has been successfully employed for the first time, to characterize the aggregate species present in mixed micellar solution due to its powerful ability to separate particles based on their size and shape and monitor them simultaneously. Analytical ultracentrifugation offers an unprecedented opportunity to obtain important information on mixed micelles, structure-performance relationship for different surfactant aggregates in solution and their role in interfacial processes. Initial sedimentation velocity investigations were conducted using nonyl phenol ethoxylated decyl ether (NP-10) to choose the best analytical protocol, calculate the partial specific volume and obtain information on sedimentation coefficient, aggregation mass of micelles. Four softwares: OptimaTM XL-A/XL-I data analysis software, DCDT+, Svedberg and SEDFIT, were compared for the analysis of sedimentation velocity experimental data. The results have been compared to that from Light Scattering. Based on the tests, Svedberg and SEDFIT analysis were chosen for further studies.

P. Somasundaran

2004-11-20

424

BEHAVIOR OF SURFACTANT MIXTURES AT SOLID/LIQUID AND OIL/LIQUID INTERFACES IN CHEMICAL FLOODING SYSTEMS  

SciTech Connect

The aim of the project is to develop a knowledge base to help with the design of enhanced process for mobilizing and extracting untrapped oil. We emphasize on evaluating novel surfactant mixtures and on obtaining optimum combinations of the surfactants in chemical flooding EOR process. An understanding of the micellar shape and size is crucial since these physical properties directly determine the crude oil removal efficiency. Analytical ultracentrifugation experiments were used to test the multi-micelle model proposed earlier and formulate the relationships between mixed micelle formation and the surfactant structure. Information on partial specific volume of surfactants and their mixtures is required to treat analytical ultracentrifuge data. In the last report, it was noted that the partial specific volumes of the sugar-based surfactants obtained experimentally did not agree with those from theoretical calculations. A scrutiny of partial specific volumes of the four sugar-based surfactants revealed that conformational changes upon micelle formation are responsible for the large deviation. From sedimentation equilibrium experiments, two types of micelles were identified for the nonionic polyethylene surfactant and its mixtures with the sugar-based surfactant, dodecyl maltoside. The average aggregation numbers of n-dodecyl-{beta}-D-maltoside and nonyl phenol ethoxylated decyl ether agreed with those reported in literature using other techniques. Our study displayed, for the first time, that small micelles might coexist with large micelles at high concentrations due to unique structures of the surfactant although classical thermodynamic theory supports only one type of micelle. Initial dynamic light scattering results support the results for the same mixed surfactant system from analytical ultracentrifuge equilibrium technique. The implication of this finding lies in the fact that efficiency of oil recovery will be improved due to the large micellar size, its polymer-like fluidity and possible reduced adsorption on solids.

Prof. P. Somasundaran

2003-03-31

425

Modeling and measurements of solid-liquid and vapor-liquid equilibria of polyols and carbohydrates in aqueous solution.  

PubMed

The solubilities of five saccharides in water have been measured at various temperatures. This includes the monosaccharides xylose and galactose, and the disaccharides maltose monohydrate, cellobiose and trehalose dihydrate. A method that uses interaction energies and interaction parameters calculated with molecular mechanics methods has shown to give good predictions of the phase behavior of a variety of mixtures, including glycols and small saccharides in aqueous solution. The method is completely predictive, as the strength of the molecular interactions is determined with a theoretical method in the absence of any phase equilibrium data. For calculating solubilities, experimental values for the melting points and the heats of fusion of the compounds under study are, however, necessary. The solubilities of the five saccharides listed above, raffinose and meso-erythritol in water were calculated with this method. The calculated solubilities are in reasonably good agreement with experiment, and in the case of meso-erythritol, which is a polyalcohol (polyol), and galactose, the agreement between prediction and experiment is excellent. Also the vapor pressures of water over several polyols and saccharides in aqueous solution have been predicted with this method, giving results in excellent agreement with the experimental values. PMID:12350326

Jnsdttir, Svava Osk; Cooke, Stephen A; Macedo, Eugnia A

2002-09-27

426

Morphological instability of the solid-liquid interface in crystal growth under supercooled liquid film flow and natural convection airflow  

E-print Network

Ring-like ripples on the surface of icicles are an example of morphological instability of the ice-water interface during ice growth under supercooled water film flow. The surface of icicles is typically covered with ripples of about 1 cm in wavelength, and the wavelength appears to be almost independent of external temperature, icicle radius, and volumetric water flow rate. One side of the water layer consists of the water-air surface and growing ice is the other. This is one of the more complicated moving phase boundary problems with two interfaces. A recent theoretical work [K. Ueno, Phys. Rev. E 68, (2003) 021603] to address the underlying instability that produces ripples is based on the assumption of the absence of airflow around icicles. In this paper, we extend the previous theoretical framework to include a natural convection airflow ahead of the water-air surface and consider whether the effect of natural convection airflow on the wavelength of ripples produced on an ice surface is essential or not.

Ueno, K

2011-01-01

427

Solid-Liquid and Solid-Solid Transformations in the Rare-Earth Metals at High Pressures  

Microsoft Academic Search

The fusion behavior and solid-solid transformations in the rare-earth metals have been investigated at pressures in the range 6-65 kbar. The phase diagrams are presented for La, Pr, Nd, Sm, Gd, and Tb. The initial melting slopes of Dy to Lu have been obtained. Since most of the rare-earth (R.E.) metals melt from a bcc structure, they offer a series

A. Jayaraman

1965-01-01

428

A methodology for quantifying streaming electrification based on the charging tendency of solid/liquid insulation combinations  

SciTech Connect

Traditional methods for measuring the charging tendency of transformer oils do not adequately address the role of the solid material which must be present for streaming electrification to occur. A novel test cell has been designed to facilitate static charging measurements with different oil/cellulose combinations subject to realistic flow conditions. Different solid insulation materials can readily be tested over a range of thickness without modifying the test geometry. A data acquisition system is incorporated to monitor the system parameters and provides the capability for transient or steady-state measurements. The objective of the present work is to characterize the various oils currently used in industry against the different cellulose products available. Results to date clearly demonstrate the importance of the solid material in defining the charging tendency of transformer insulation materials.

Brubaker, M.A.; Walden, J.M.

1995-05-01

429

Trapped Melt in IIIAB Irons: Solid/Liquid Elemental Partitioning During the Fractionation of the IIIAB Magma  

NASA Technical Reports Server (NTRS)

Group IIIAB, the largest iron-meteorite group, shows compositional trends (including a three-order-of-magnitude It concentration range) indicating that it formed by fractional crystallization of a metallic magma. Because about 200 irons are available, and all degrees of crystallization are well represented, IIIAB offers an excellent set of samples for the study of crystallization at all depths of the asteroidal core. On log-log Ir-Au, and Ir-As diagrams IIIAB forms a broad band; the breadth represents real meteorite-to-meteorite variations, far outside experimental or sampling uncertainties. A successful model must explain the width of this band; I suggest that it mainly resulted from the trapping of parental magma within the crystallizing solid. Because S is essentially insoluble in metal, the abundance of FeS is a measure of the fraction of trapped liquid. The trapped-melt model is supported by the observation that irons having higher S contents plot closer to the inferred composition of the magmatic parental liquid. The lowest S values are found in the irons occupying the left envelope of the IIIAB Ir-Au or Ir-As compositional fields, thus it is this set of irons that should be interpreted as the solid products of a fractionating magma. This simplifies the modeling of the crystallization process and allows inferences regarding the distribution ratios for other elements in the evolved IIIAB system. The large (multiton) Cape York irons show wide variations in their trapped-melt fractions; their compositions seem best understood in terms of a low initial S content of the IIIAB magma, about 20 mg/g. The inferred initial IIIAB distribution coefficient for Ir, 4.6, is much higher than published values based on laboratory studies of low-S systems; I suggest that low-S (and low-P) partition-ratio measurements tend to err in the direction of unity. In IIIAB distribution coefficients for Au, As, and Ni were still < 1 when the most evolved IIIAB irons formed, another indication of a low initial S content.

Wasson, John T.

1999-01-01

430

Chemical Engineering Science 55 (2000) 4993}5001 A further study of solid}liquid equilibrium for the  

E-print Network

.8%, Beijing Chemical Plant, Beijing) was dried in a vacuum dryer until a constant mass was reached. Ammonium chloride (Guaranteed grade, purity '99.8%, YuLing Chemical Plant, Shanghai) was dried in a vacuum desic- cator at 0.01 kPa and 333.15 K for 4 h. The deionized water was prepared by re-distillation

Zhang, Luzheng

431

Investigating Solids, Liquids, and Gases with TOYS: States of Matter and Changes of State. Activities for Middle School Grades.  

ERIC Educational Resources Information Center

The project Teaching Science with TOYS promotes toys as an ideal mechanism for science instruction, because they are an everyday part of the students' world and carry a user-friendly message. TOYS Teacher Resource Modules are collections of "TOYS" activities grouped around a topic or theme with supporting science content and pedagogical materials.

Sarquis, Jerry; Hogue, Lynn; Sarquis, Mickey; Woodward, Linda

432

Functionalized surface-confined pores: guest binding directed by lateral noncovalent interactions at the solid-liquid interface.  

PubMed

We present here the construction of self-assembled two-dimensional (2D) molecular networks that contain pores equipped with functional groups that promote guest-specific binding at the liquid/solid interface. For this purpose, a dehydrobenzo[12]annulene (DBA) derivative, DBA-F, having perfluoroalkyl groups at the end of the three alternating alkoxy chains connected by para-phenylene linkers was synthesized. For comparison DBA-H, having the same carbon backbone without fluorine substituents, was also prepared. STM observations revealed that these molecules formed porous 2D networks whose pores were decorated with either fluoroalkane or simple alkane perimeters. Hexakis(phenylethynyl)benzene, HPEB, and its octadecafluoro derivative, HPEB-F surrounded by 18 fluorine atoms, were employed as planar guest molecules of suitable size. The fluoroalkane-lined pores present in the network of DBA-F exhibited good binding ability toward both guest molecules via fluorophilicity and electrostatic interaction, respectively. In contrast the binding ability of the alkane-lined pore of the network of DBA-H for the fluorinated guest HPEB-F was poor as a result of weaker electrostatic interaction. Interestingly, with HPEB as a guest, this network underwent a periodical structural deformation through an induced-fit mechanism to form a superlattice structure consisting of free and occupied pores. These observations are discussed based on modeling experiments using molecular mechanics and quantum chemical methods to elucidate the roles of lateral noncovalent interactions and size matching between the pore and the guest molecules used for 2D guest binding. PMID:25089732

Tahara, Kazukuni; Katayama, Keisuke; Blunt, Matthew Oliver; Iritani, Kohei; De Feyter, Steven; Tobe, Yoshito

2014-08-26

433

Surface-induced changes in the structure and activity of enzymes physically immobilized at solid/liquid interfaces.  

PubMed

A proteolytic enzyme, alpha-chymotrypsin, and a lipolytic enzyme, cutinase, were adsorbed from aqueous solutions on solid surfaces with different hydrophobicities and morphologies. With both enzymes the affinity of adsorption is larger for the more hydrophobic surface. Water-soluble, flexible oligomers grafted on the sorbent surface cause a decrease in enzyme adsorption. CD spectroscopy and differential scanning calorimetry (DSC) indicate severe structural perturbations in the enzymes resulting from adsorption. The CD spectra reflect an average of the structure of the whole protein population. The DSC data allow additional conclusions to be drawn on the heterogeneity in the conformational states of the adsorbed enzymes. The degree of structural perturbation, that is the fraction of the adsorbed molecules of which the structure is perturbed, is lower at a surface that (1) is less hydrophobic, (2) contains water-soluble flexible oligomers and (3) is more covered by the protein. The specific activities of the enzymes are decreased on adsorption, more or less following the extent of structural perturbation. Unlike in solution, in the adsorbed state the heat-induced inactivation process is not identical with the heat-induced unfolding process. Furthermore, when the enzymes are adsorbed their specific activities are much less sensitive to temperature variation. PMID:9756464

Norde, W; Zoungrana, T

1998-10-01

434

Superhydrophobic photosensitizers. Mechanistic studies of (1)O2 generation in the plastron and solid/liquid droplet interface.  

PubMed

We describe here a physical-organic study of the first triphasic superhydrophobic sensitizer for photooxidations in water droplets. Control of synthetic parameters enables the mechanistic study of "borderline" two- and three-phase superhydrophobic sensitizer surfaces where (1)O2 is generated in compartments that are wetted, partially wetted, or remain dry in the plastron (i.e., air layer beneath the droplet). The superhydrophobic surface is synthesized by partially embedding silicon phthalocyanine (Pc) sensitizing particles to specific locations on polydimethylsiloxane (PDMS) posts printed in a square array (1 mm tall posts on 0.5 mm pitch). In the presence of red light and oxygen, singlet oxygen is formed on the superhydrophobic surface and reacts with 9,10-anthracene dipropionate dianion (1) within a freestanding water droplet to produce an endoperoxide in 54-72% yields. Control of the (1)O2 chemistry was achieved by the synthesis of superhydrophobic surfaces enriched with Pc particles either at the PDMS end-tips or at PDMS post bases. Much of the (1)O2 that reacts with anthracene 1 in the droplets was generated by the sensitizer "wetted" at the Pc particle/water droplet interface and gave the highest endoperoxide yields. About 20% of the (1)O2 can be introduced into the droplet from the plastron. The results indicate that the superhydrophobic sensitizer surface offers a unique system to study (1)O2 transfer routes where a balance of gas and liquid contributions of (1)O2 is tunable within the same superhydrophobic surface. PMID:24295210

Aebisher, David; Bartusik, Dorota; Liu, Yang; Zhao, Yuanyuan; Barahman, Mark; Xu, QianFeng; Lyons, Alan M; Greer, Alexander

2013-12-18

435

Enzyme-assisted physicochemical enantioseparation processesPart II: Solidliquid equilibria, preferential crystallization, chromatography and racemization reaction  

Microsoft Academic Search

This contribution addresses the design and investigation of two hybrid enantioseparation processes including an enzymatic racemization step in order to enhance the overall performance. Complementary to part I where the manufacturing and the characterization of an amino acid racemase (EC 5.1.1.10) was emphasized [Wrges, K., Petrusevska, K., Serci, S., Wilhelm, S., Wandrey, C., Seidel-Morgenstern, A., Elsner, M.P., Ltz, S., 2009.

Katerina Petruevska-Seebach; Kerstin Wrges; Andreas Seidel-Morgenstern; Stephan Ltz; Martin P. Elsner

2009-01-01

436

Ab initio calculations of quasiparticle energies of solids, liquids and molecules using a spectral decomposition of the dielectric matrix  

NASA Astrophysics Data System (ADS)

We recently developed a method for the calculation of quasiparticle energies within many body perturbation theory, at the GW level, which avoids costly summations over empty electronic states and does not require the use of plasmon-pole models [1]. We present a comprehensive validation of this method, encompassing calculations of i) the vertical ionization energies of a set of over 80 molecules (containing from 14 to 424 valence electrons); ii) the relative position of energy levels of anions and water in hydrated sulfate and chloride clusters; iii) the band structure of a variety of semiconductors and (iv) the electronic properties of amorphous and liquid systems. The efficiency of our approach allowed us to compute quasiparticle energies of multiple configurations of liquid water, using samples with 64 molecules, selected over trajectories generated by ab initio molecular dynamics simulations. [4pt] [1] H. Viet Nguyen, T. Anh Pham, D. Rocca and G. Galli, Phys. Rev. B 85, 081101(R) (2012); T. Anh Pham, H. Viet Nguyen, D. Rocca and G. Galli (submitted)

Pham, Tuan Anh; Nguyen, Huy-Viet; Rocca, Dario; Galli, Giulia

2013-03-01

437

Second Harmonic Generation as a Probe of Multisite Adsorption at Solid-Liquid Interfaces of Aqueous Colloid Suspensions  

E-print Network

and the creation of better paints and cosmetics. Particles in these systems are often characterized by molecular for particle size measurements.7 Conventional (i.e. linear) spectro- scopic measurements of adsorbed species; In Final Form: August 9, 2006 Chemistry at the surface of solid particles in colloidal dispersions

Borguet, Eric

438

Experimental Determination of the Ammonium Sulfate/Maleic Acid/Water Solid/Liquid Ternary Phase Diagram  

NASA Astrophysics Data System (ADS)

The formation of cirrus clouds can be directly affected by aerosols present in the atmosphere. While many systems consisting of inorganic aerosols have been widely studied, work has only recently been undertaken to study systems consisting of organic and mixed inorganic/organic aerosols. Our research group has extensively studied the ice region of the mixed inorganic/organic Ammonium Sulfate/Maleic Acid/Water ternary system using differential scanning calorimetry and IR spectroscopy of thin films. Our data was primarily collected at temperatures below 298 K, maleic acid concentrations below 0.30 total mass fraction, and ammonium sulfate concentrations below 0.40 total mass fraction. Using this data, we have generated a ternary liquid/solid phase diagram which can be used to determine which phases of matter will be present in the system at different compositions and temperatures, and we report a ternary eutectic temperature of 252.14 K. We have directly compared our experimental data to data generated using the Aerosol Inorganics Model (AIM). This thermodynamic model can be used to predict aerosol composition at varying atmospheric conditions. It was found that the AIM predicted final melt temperature deviated most from our experimentally determined final melt temperature at high maleic acid concentrations. Since there is very little existing data for the the ammonium sulfate/maleic acid/water ternary system, our experimental data can be directly used to make corrections and improve the accuracy of this model. This research will prove to be of increasing value as we look to understand the role clouds play on climate systems.

Schroeder, J. R.; Beyer, K.

2009-05-01

439

Physical Characterization of Solid-Liquid Slurries at High Weight Fractions Using Optical and Ultrasonic Methods, Final Report  

SciTech Connect

Remediation of highly radioactive waste is a major technical and programmatic challenge for the DOE. Rapid, on-line physical characterization of highly concentrated slurries is required for the safe and efficient remediation of 90 million gallons of high level radioactive waste (HLW), sodium bearing waste, and mixed waste. The research presented here, describes a collaborative effort between Pacific Northwest National Laboratory (PNNL) and the University of Washington to directly address the need for rapid on-line characterization of the physical properties of HLW slurries during all phases of the remediation process, from in-tank characterization of sediments to monitoring of the concentration, particle size, and degree of agglomeration and gelation of slurries during transport. Near-surface characterization of the slurry flow in the particle size range from nanometer to micrometer is examined using optical low coherence reflectometry. Volumetric characterization at depths in the slurry flow, up to several centimeters in the particle size range from the micrometer to millimeter, is realized by utilizing ultrasonic backscatter and diffuses fields. One of the strengths, the teaming up of significant talents in both experimental and theoretical optics (University of Washington) and in ultrasonics [Pacific Northwest National Laboratory (PNNL)] provides a synergistic approach to integrate these complimentary techniques. One of the benefits of this combined approach is the physical characterization of HLW over a concentration and particle size range that is broader than can be achieved with todays technology. This will avoid a costly increase in waste stream volume due to excess dilution, and will lessen chance of plugging pipes that could shut down expensive processing lines.

Burgess, Lloyd W.

2009-09-17

440

Surface-induced solid-liquid phase transitions in ultra-thin water films at T > 0 ^oC  

Microsoft Academic Search

We report here the measurements of both the adsorption isotherms and the dissipation in ultra-thin films of water adsorbed on the surfaces of SiO2 . The measurements were made in a small high vacuum chamber in which we have mounted a QCM. The chamber was evacuated to 10-8 Torr and then filled with water vapor at pressures ranging from 10-3

Animesh Chakraborty; Andrew Gellman; Layton Baker; Estebahn Broitman

2008-01-01

441

Direct observation of ionic structure at solid-liquid interfaces: a deep look into the Stern Layer  

PubMed Central

The distribution of ions and charge at solid-water interfaces plays an essential role in a wide range of processes in biology, geology and technology. While theoretical models of the solid-electrolyte interface date back to the early 20th century, a detailed picture of the structure of the electric double layer has remained elusive, largely because of experimental techniques have not allowed direct observation of the behaviour of ions, i.e. with subnanometer resolution. We have made use of recent advances in high-resolution Atomic Force Microscopy to reveal, with atomic level precision, the ordered adsorption of the mono- and divalent ions that are common in natural environments to heterogeneous gibbsite/silica surfaces in contact with aqueous electrolytes. Complemented by density functional theory, our experiments produce a detailed picture of the formation of surface phases by templated adsorption of cations, anions and water, stabilized by hydrogen bonding. PMID:24850566

Siretanu, Igor; Ebeling, Daniel; Andersson, Martin P.; Stipp, S. L. Svane; Philipse, Albert; Stuart, Martien Cohen; van den Ende, Dirk; Mugele, Frieder

2014-01-01

442

Organically modified silica with pyrazole-3-carbaldehyde as a new sorbent for solid-liquid extraction of heavy metals.  

PubMed

A new chelating matrix, SiNP, has been prepared by immobilizing 1.5-dimethyl-1H-pyrazole-3-carbaldehyde on silica gel modified with 3-aminopropyl-trimethoxysilane. This new chelating material was well characterized by elemental analysis, FT-IR spectroscopy, cross polarization magic angle spinning solid state 13C-NMR, nitrogen adsorption-desorption isotherm, BET surface area, BJH pore size, and scanning electron microscopy (SEM). The new product exhibits good chemical and thermal stability as determined by thermogravimetry curves (TGA). The new prepared material was used as an adsorbent for the solid-phase extraction (SPE) of Pb(II), Cd(II), Cu(II) and Zn(II) from aqueous solutions using a batch method, prior to their determination by flame atomic adsorption spectrometry. The adsorption capacity was investigated using kinetics and pH effects. Common coexisting ions did not interfere with separation and determination. PMID:24368604

Radi, Smaail; Tighadouini, Said; Bacquet, Maryse; Degoutin, Stphanie; Cazier, Francine; Zaghrioui, Mustapha; Mabkhot, Yahia N

2013-01-01

443

Direct observation of ionic structure at solid-liquid interfaces: a deep look into the Stern Layer  

NASA Astrophysics Data System (ADS)

The distribution of ions and charge at solid-water interfaces plays an essential role in a wide range of processes in biology, geology and technology. While theoretical models of the solid-electrolyte interface date back to the early 20th century, a detailed picture of the structure of the electric double layer has remained elusive, largely because of experimental techniques have not allowed direct observation of the behaviour of ions, i.e. with subnanometer resolution. We have made use of recent advances in high-resolution Atomic Force Microscopy to reveal, with atomic level precision, the ordered adsorption of the mono- and divalent ions that are common in natural environments to heterogeneous gibbsite/silica surfaces in contact with aqueous electrolytes. Complemented by density functional theory, our experiments produce a detailed picture of the formation of surface phases by templated adsorption of cations, anions and water, stabilized by hydrogen bonding.

Siretanu, Igor; Ebeling, Daniel; Andersson, Martin P.; Stipp, S. L. Svane; Philipse, Albert; Stuart, Martien Cohen; van den Ende, Dirk; Mugele, Frieder

2014-05-01

444

State Application Identifier Applicant Identifier  

E-print Network

to criminal, civil, or administrative penalties. (U.S. Code, Title 18, Section 1001) 19. Authorized? TITLE: 11. * DESCRIPTIVE TITLE OF APPLICANT'S PROJECT: 12. * AREAS AFFECTED BY PROJECT (cities, counties. DATE RECEIVED BY STATE APPLICATION FOR FEDERAL ASSISTANCE SF 424 (R&R) County: * State: County: OMB

Kaminsky, Werner

445

Changements importants pour vos accommodements aux examens  

E-print Network

� par le professeur. Il doit le faire parvenir � Alain Constantine Constantine � l'adresse suivante : alain.constantine@umontreal.ca dans les d�lais de 3 semaines. Pour les �tudiants de la Facult� de l

Leclercq, Remi

446

Services aux tudiants Bureau des tudiants internationaux  

E-print Network

plaisir de vous remettre la bourse de mobilité en vertu du Programme de bourses pour de courts séjours; · Expliquer en quoi l'expérience à l'étranger au sein de l'institution d'accueil a représenté une valeur MOIS après la fin de la période pour laquelle vous avez obtenu la bourse de mobilité. Nous vous

Montréal, Université de

447

Services aux tudiants Bureau des tudiants internationaux  

E-print Network

le plaisir de vous remettre la bourse de mobilité en vertu du Programme de bourses pour de courts bourse de mobilité. Le rapport d'une longueur d'environ 3 pages doit inclure les éléments suivants: · Un sein de l'institution d'accueil a représenté une valeur ajoutée à votre formation · Commentaires ou

Montréal, Université de