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1

Solids Liquids and Gases  

NSDL National Science Digital Library

Compare and contrast the three states of matter: solids, liquids and gases. First you will begin by looking at characteristics of each solids, liquids and gasesGases, Liquids and Solids Facts. Then you will look at examples of each stateSolids, Liquids and Gases Video. Demonstrate an understanding of solids, liquids and gases by playing interactive gameSolids, Liquids and Gases Game. Graphic Organizer is here to be filled out as you learn during this lesson. Use the red ...

Ms. Salter

2009-10-22

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

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

4

A sessile drop setup for the time-resolved synchrotron study of solid-liquid interactions: Application to intermetallic formation in 55%Al-Zn alloys  

NASA Astrophysics Data System (ADS)

We introduce a dedicated setup for measuring by synchrotron diffraction in-situ crystallographic and chemical information at the solid-liquid interface. This setup mostly consists of a double-heating furnace composed of a resistive heating for the solid surface and an inductive heating to produce a liquid droplet. The available high energy and high flux beams allow the rapid reaction kinetics to be investigated with very good time resolution down to 1 ms. An application of this setup is illustrated for the growth mechanisms of intermetallic phases during the hot-dipping of steel in a 55%Al-Zn bath. Results show that the three ?-Al5Fe2, ?-Al13Fe4, and ?-Al8Fe2Si phases grow at different times and rates during the dipping process, whereas the face-centered cubic AlFe3 phase is not formed.

Bernier, N.; Vaughan, G. B. M.; De Bruyn, D.; Vitoux, H.; De Craene, M.; Gleyzolle, H.; Gorges, B.; Scheers, J.; Claessens, S.

2014-04-01

5

A sessile drop setup for the time-resolved synchrotron study of solid-liquid interactions: Application to intermetallic formation in 55%Al-Zn alloys  

SciTech Connect

We introduce a dedicated setup for measuring by synchrotron diffraction in-situ crystallographic and chemical information at the solid–liquid interface. This setup mostly consists of a double-heating furnace composed of a resistive heating for the solid surface and an inductive heating to produce a liquid droplet. The available high energy and high flux beams allow the rapid reaction kinetics to be investigated with very good time resolution down to 1 ms. An application of this setup is illustrated for the growth mechanisms of intermetallic phases during the hot-dipping of steel in a 55%Al-Zn bath. Results show that the three ?-Al{sub 5}Fe{sub 2}, ?-Al{sub 13}Fe{sub 4}, and ?-Al{sub 8}Fe{sub 2}Si phases grow at different times and rates during the dipping process, whereas the face-centered cubic AlFe{sub 3} phase is not formed.

Bernier, N., E-mail: n.bernier@yahoo.fr; De Bruyn, D.; De Craene, M.; Scheers, J.; Claessens, S. [OCAS N.V., ArcelorMittal Global R and D Gent, Pres. J.F. Kennedylaan 3, 9060 Zelzate (Belgium); Vaughan, G. B. M.; Vitoux, H.; Gleyzolle, H.; Gorges, B. [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble Cedex (France)

2014-04-28

6

Design and Application of a Freestanding Sensor Based on 3 ? Technique for Thermal-Conductivity Measurement of Solids, Liquids, and Nanopowders  

NASA Astrophysics Data System (ADS)

A practical and reusable freestanding sensor based on the 3 ? technique is fabricated by encapsulating a nano-thick nickel detector between two pieces of Kapton film. Because of the protection of the Kapton layer, the mechanical strength and applicability of the sensor are greatly improved compared with the traditional 3 ? sensor. Furthermore, the nondestructive thermal-conductivity characterization for solids, liquids, and nanopowder specimens based on the 3 ? technique is first realized. However, the introduction of the additional protective film also induces an undesirable decrease in accuracy for the thermal-conductivity measurement. This article discusses the underlying reason for this decreased accuracy and accordingly proposes an error correction scheme for accurate determination of the thermal conductivity.

Qiu, L.; Zheng, X. H.; Su, G. P.; Tang, D. W.

2013-12-01

7

Solid-Liquid Interfacial Premelting  

E-print Network

We report the observation of a premelting transition at chemically sharp solid-liquid interfaces using molecular-dynamics simulations. The transition is observed in the solid-Al—liquid-Pb system and involves the formation of a liquid interfacial...

Yang, Yang; Asta, Mark; Laird, Brian Bostian

2013-02-28

8

Solid-liquid interfacial premelting.  

PubMed

We report the observation of a premelting transition at chemically sharp solid-liquid interfaces using molecular-dynamics simulations. The transition is observed in the solid-Al-liquid-Pb system and involves the formation of a liquid interfacial film of Al with a width that grows logarithmically as the bulk melting temperature is approached from below, consistent with current theories of premelting. The premelting behavior leads to a sharp change in the temperature dependence of the diffusion coefficient in the interfacial region and could have important consequences for phenomena such as particle coalescence and shape equilibration, which are governed by interfacial kinetic processes. PMID:23496728

Yang, Yang; Asta, Mark; Laird, Brian B

2013-03-01

9

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

10

Intermittent molecular hopping at the solid-liquid interface.  

PubMed

The mobility of molecules on a solid surface plays a key role in diverse phenomena such as friction and self-assembly and in surface-based technologies like heterogeneous catalysis and molecular targeting. To understand and control these surface processes, a universally applicable model of surface transport at solid-liquid interfaces is needed. However, unlike diffusion at a solid-gas interface, little is known about the mechanisms of diffusion at a solid-liquid interface. Using single-molecule tracking at a solid-liquid interface, we found that a diverse set of molecules underwent intermittent random walks with non-Gaussian displacements. This contrasts with the normal random walk and Gaussian statistics that are commonly assumed for molecular surface diffusion. The molecules became temporarily immobilized for random waiting times between surface displacements produced by excursions through the bulk fluid. A common power-law distribution of waiting times indicated a spectrum of binding energies. We propose that intermittent hopping is universal to molecular surface diffusion at a solid-liquid interface. PMID:23829747

Skaug, Michael J; Mabry, Joshua; Schwartz, Daniel K

2013-06-21

11

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

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

PROBLMES POSS POUR L'APPLICATION DES ALLIAGES DE NIOBIUM AUX AUBES DE TURBINE  

E-print Network

513 PROBL�MES POS�S POUR L'APPLICATION DES ALLIAGES DE NIOBIUM AUX AUBES DE TURBINE par G. GAUJE et R. BRUNETAUD Direction Technique de la SNECMA Résumé. 2014 L'emploi d'alliages de niobium à la place of niobium alloys instead of the current alloys with nickel or cobalt as parent metal for manufacturing

Boyer, Edmond

14

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

SciTech Connect

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.

Warshavsky, Vadim B.; Song, Xueyu

2012-09-18

15

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

NASA Astrophysics Data System (ADS)

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.

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

A Review of Quantitative Phase-Field Crystal Modeling of Solid-Liquid Structures  

NASA Astrophysics Data System (ADS)

Phase-field crystal (PFC) is a model with atomistic-scale details acting on diffusive time scales. PFC uses the density field as its order parameter, which takes a constant value in the liquid phase and a periodic function in the solid phase. PFC naturally takes into account elasticity, solid-liquid interface free energy, surface anisotropy, and grain boundary free energy by using this single-order parameter in modeling of coexisting solid-liquid structures. In this article, the recent advancements in PFC modeling of materials nanostructures are reviewed, which includes an overview of different PFC models and their applications, and the numerical algorithms developed for solving the PFC governing equations. A special focus is given to PFC models that simulate coexisting solid-liquid structures. The quantitative PFC models for solid-liquid structures are reviewed, and the methods for determining PFC model parameters for specific materials are described in detail. The accuracy of different PFC models in calculating the solid-liquid interface properties is discussed.

Asadi, Ebrahim; Asle Zaeem, Mohsen

2015-01-01

19

L'acceptabilit du placement de marques dans les jeux vido : une application aux joueurs de 15-35 ans  

E-print Network

managerial implications. Key-words: Advergaming, acceptability, brand placement, product placement, video1 L'acceptabilité du placement de marques dans les jeux vidéo : une application aux joueurs de 15 placement de marques dans les jeux vidéo souffre du peu de recherches sur l'attitude des joueurs à son égard

Paris-Sud XI, Université de

20

Ultrasonic characterization of solid liquid suspensions  

DOEpatents

Using an ultrasonic field, properties of a solid liquid suspension such as through-transmission attenuation, backscattering, and diffuse field are measured. These properties are converted to quantities indicating the strength of different loss mechanisms (such as absorption, single scattering and multiple scattering) among particles in the suspension. Such separation of the loss mechanisms can allow for direct comparison of the attenuating effects of the mechanisms. These comparisons can also indicate a model most likely to accurately characterize the suspension and can aid in determination of properties such as particle size, concentration, and density of the suspension.

Panetta, Paul D.

2010-06-22

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

Solid–liquid transport in a modified co-rotating twin-screw extruder—dynamic simulator and experimental validations  

Microsoft Academic Search

This work presents a dynamic transport model of a solid–liquid media through a twin-screw extruder (TSE). The application under consideration is the solid–liquid extraction of solute from raw plant substrate. Dynamic experiments are performed and compared with the simulated results for step functions on the solid feed rate and on the screw rotating speed. Despite some imperfections, results allow to

L. Prat; S. N’Diaye; L. Rigal; C. Gourdon

2004-01-01

23

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

24

CdS spray : laboration. Proprits physiques applications aux cellules solaires Cu2S-CdS  

E-print Network

have realized an apparatus to fabricate CdS thin films by spray. The different studies on physical585 CdS « spray » : élaboration. Propriétés physiques applications aux cellules solaires Cu2S-CdS M au point un appareillage de fabrication de lames de CdS par la méthode de pulvérisa- tion chimique

Paris-Sud XI, Université de

25

Etude sur les tendons en materiaux composites et leur application aux ancrages postcontraints  

NASA Astrophysics Data System (ADS)

L'objectif general de la presente these est d'evaluer le comportement a l'arrachement et au fluage d'ancrages injectes constitues de tendons en materiaux composites afin d'etablir des recommandations plus appropriees et realistes pour le dimensionnement et la conception. Quatre types de tendons en materiaux composites, deux a base de fibres d'aramide et deux a base de fibres de carbone, ont ete utilises dans l'etude. Les travaux de recherche de cette these ont porte notamment sur: (I) Une caracterisation physique et mecanique des tendons en materiaux composites utilises dans l'etude. (II) Une etude en laboratoire sur les coulis de scellement. La premiere etape de cette etude a concerne le developpement d'un coulis de scellement performant adapte aux tendons en materiaux composites et a differentes situations d'injection. La seconde etape a traite des essais de caracterisations physique et mecanique du coulis de scellement developpe comparativement a trois coulis de scellement usuels d'un meme rapport E/L de 0,4. (III) Une etude sur des modeles reduits d'ancrages injectes. (IV) Une etude sur des modeles d'ancrages a grande echelle. La synthese de ces etudes a permis d'enoncer les principales conclusions suivantes: (1) Les valeurs moyennes des charges de rupture des tendons en materiaux composites ont ete de 1% a 29% superieures a celles specifiees par les manufacturiers. (2) L'etude sur les coulis de scellement a permis le developpement de coulis de ciment repondant aux criteres fixes, soient une grande stabilite, une bonne fluidite, une legere expansion et de bonnes caracteristiques mecaniques. (3) Les tendons en materiaux composites ont montre des contraintes d'adherence maximum superieures a celles des tendons en acier. (4) Le type de fibre, la configuration et le fini de surface des tendons en materiaux composites gouvernent leur resistance a l'adherence. (5) L'introduction de sable et d'autres ajouts comme les fines de silice et la poudre d'aluminium au coulis de ciment a permis d'ameliorer la resistance a l'adherence. (6) Il existe une relation lineaire entre la charge maximum et la longueur ancree des tendons. Des equations sont proposees. (7) La capacite a l'arrachement des ancrages injectes augmente avec l'augmentation du module d'elasticite du milieu encaissant. (8) Les mono-tendons et multi-tendons en materiaux composites injectes sur 1000 mm ont montre des comportements a l'arrachement acceptables conformement aux codes. (9) Les rigidites apparentes des tendons a base de fibres d'aramide sont de trois a cinq fois inferieures a celles des tendons a base de fibres de carbone. (10) L'amorce de la decohesion en haut de la zone ancree ne semble se produire qu'au-dela d'une charge de 0,35 fpu pour les tendons a base de fibres de carbone alors qu'elle prend naissance des l'application de la charge pour les tendons a base de fibres d'aramide. (11) Le taux de fluage depend du niveau de chargement ainsi que des caracteristiques geometriques et mecaniques de l'ancrage (type de fibres, fini de surface, nombre de tendons, etc.). (12) Des equations regissant le comportement au fluage des tendons en materiaux composites ont ete etablies pour une periode d'essai de 60 mn. (Abstract shortened by UMI.)

Chennouf, Adil

26

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

27

In situ real-time monitoring of geometric, electronic, and molecular structures at solid/liquid interfaces  

NASA Astrophysics Data System (ADS)

Many important processes take place at solid/liquid interfaces. To understand these processes, in situ real-time evaluation of the geometric, electronic, and molecular structures at solid/liquid interfaces at the atomic and molecular levels is essential. Owing to the presence of the liquid, however, techniques such as electron microscopy and low-energy electron diffraction, which are powerful tools for surface structural analysis in vacuum, cannot be used for solid/liquid interfaces. In this review, various techniques applicable to solid/liquid interfaces, including scanning probe microscopy, synchrotron-radiation-based X-ray techniques, and nonlinear spectroscopy, are briefly described. The characterization of the electrodeposition process of Pd layers on Au single-crystal electrode surfaces is presented as an example to demonstrate the importance of using multiple techniques in an integrated manner to understand the processes at solid/liquid interfaces. This is a translated version of the original paper which appeared in Oyo Buturi 82, 106 (2013) [in Japanese] with some modifications.

Uosaki, Kohei

2015-03-01

28

A theory of cavity formation at solid-liquid interfaces  

Microsoft Academic Search

A theory of cavity formation at solid-liquid interfaces has been derived which describes cavitational behaviour in terms of the dispersion forces and of the surface tension of the liquid. The resulting relationships are easily applied to experimental data. The equations have been successfully tested with existing experimental data.

Donald J. Cotton

1972-01-01

29

Quantitative modeling of the equilibration of two-phase solid-liquid Fe by atomistic simulations on diffusive time scales  

NASA Astrophysics Data System (ADS)

In this paper, molecular dynamics (MD) simulations based on the modified-embedded atom method (MEAM) and a phase-field crystal (PFC) model are utilized to quantitatively investigate the solid-liquid properties of Fe. A set of second nearest-neighbor MEAM parameters for high-temperature applications are developed for Fe, and the solid-liquid coexisting approach is utilized in MD simulations to accurately calculate the melting point, expansion in melting, latent heat, and solid-liquid interface free energy, and surface anisotropy. The required input properties to determine the PFC model parameters, such as liquid structure factor and fluctuations of atoms in the solid, are also calculated from MD simulations. The PFC parameters are calculated utilizing an iterative procedure from the inputs of MD simulations. The solid-liquid interface free energy and surface anisotropy are calculated using the PFC simulations. Very good agreement is observed between the results of our calculations from MEAM-MD and PFC simulations and the available modeling and experimental results in the literature. As an application of the developed model, the grain boundary free energy of Fe is calculated using the PFC model and the results are compared against experiments.

Asadi, Ebrahim; Asle Zaeem, Mohsen; Nouranian, Sasan; Baskes, Michael I.

2015-01-01

30

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

31

Experimental observation of the interaction of inert particles at a solid-liquid interface  

SciTech Connect

The influence of operating parameters on the interaction of inert particles at a solid-liquid interface is studied in a low temperature directional solidification apparatus. Experiments have been carried out in a transparent model system of succinonitrile so that the interactions at the interface can be monitored in situ. Different experimental conditions which give rise to initial steady-state, planar, cellular, and dendritic interfaces are investigated. The results are examined in the context of the application to the processing of cast composite materials. A model is developed towards numerical simulations of the phenomena observed experimentally.

Sidbury, C.K.; Meyers, C.; Desai, P. [Georgia Inst. of Tech., Atlanta, GA (United States). George W. Woodruff School of Mechanical Engineering

1995-12-31

32

Nanoscale thermal transport at solid-liquid interfaces  

Microsoft Academic Search

This thesis focuses on the experimental study of nanoscale thermal transport across solidliquid interfaces in both nanoparticle system and planar thin film system. Thermal conductance of solid-liquid interfaces, G, will be measured using time-domain thermo-reflectance and pump-probe transient absorption. Interface thermal conductance, G, relates the temperature drop DeltaT at an interface to the flux of heat F that crosses the

Zhenbin Ge

2006-01-01

33

Solid–Liquid Phase Change Driven by Internal Heat Generation  

SciTech Connect

This article presents results of solid-liquid phase change, the Stefan Problem, where melting is driven internal heat generation, in a cylindrical geometry. The comparison between a quasi-static analytical solution for Stefan numbers less than one and numerical solutions shows good agreement. The computational results of phase change with internal heat generation show how convection cells form in the liquid region. A scale analysis of the same problem shows four distinct regions of the melting process.

John Crepeau; Ali s. Siahpush

2012-07-01

34

Electrofiltration: An Energy Efficient Alternative in Solid-Liquid Separations  

E-print Network

of the anode. The specif ic selection of an anolyte is often a strong function of the material being dewatered. The membrane permits the passage of ionic current between the slurry and anolyte, while preventing the intermixing of the two fluids. The judi...ELECTROFILTRATION: AN ENERGY EFFICIENT ALTERNATIVE IN SOLID-LIQUID SEPARATIONS James M. Bollinger Robert A. Adams Dorr-Oliver, Incorporated Stamford, Connecticut ABSTRACT Electrofiltration has established itself as an energy efficient...

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

1984-01-01

35

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

36

Comparison study of solid-liquid separation techniques for oilfield pit closures  

SciTech Connect

Extensive bench-scale and full-scale experiments were conducted at the LSU Solids Control Environmental Laboratory in order to evaluate application of the solids-liquid separation technology to oilfield waste pit volume reduction. The experiments addressed chemical conditioning of various pit slurries such as water-base and oil-base mud reserve pit slurries, mixed sludge from offshore operations, and oil production pit slurry. Effective treatment was found for the majority of the waste samples with pH adjustment and with nonionic and low-charge anionic, high molecular weight polymers. Ultimate dewaterability of various samples was determined by use of the belt press bench simulator. Bench simulators of belt press filtration, vacuum filtration and centrifuge sedimentation were used for design and optimization of the full-scale tests. Alternative solid-liquid separation techniques such as vacuum filtration, belt press filtration, screw press filtration and centrifuging were pilot-tested using field-size equipment and 200 bbls samples of water-base mud, reserve pit slurry and production pit sludge. The test data were analyzed at various operating conditions using a new graphical technique. Also, four typical oilfield solid-bowl centrifuges and a modern solid-bowl dewatering decanter were compared in a series of full-scale tests. Finally a preliminary process study on the mechanism of centrifuge separation of flocculated sludges was performed.

Wojtanowicz, A.C.; Field, S.D.; Osterman, M.C.

1986-01-01

37

Manifestations de la transition solide-liquide dans les agrégats  

NASA Astrophysics Data System (ADS)

The thermodynamics of clusters is a subject of increasing interest, both from the theoretical and experimental points of view. We present a set of theoretical and numerical methods for studying phase transitions, especially the solid-liquid transition, in atomic or molecular clusters. Several means of characterization (thermodynamical, geometrical and dynamical) are introduced, and the differences between the finite-size behaviour and the bulk behaviour are described. The phenomenon of "dynamical coexistence", which can be seen as the cluster spontaneously going back and forth between the solid and liquid states across the time, is illustrated. Its thermodynamical consequences are also emphasized. Finally, we present some typical thermodynamical phenomena due to the finite-size character, and strongly dependent on the physical chemistry of the matter at the microscopic level. We study these phenomena with Monte Carlo and molecular dynamics simulations: surface melting observed on rare gas clusters, multistage melting observed on ionic clusters, the special behaviours of molecular clusters, and the more intricate problem of free or solvated metallic clusters. La thermodynamique des agrégats est un sujet en développement croissant, tant sur le plan théorique qu'expérimental. Nous présentons un ensemble de méthodes théoriques et numériques destinées à l'étude des transitions de phase, en particulier de la transition solide-liquide, dans les agrégats atomiques et moléculaires. Divers moyens de caractérisation (thermodynamiques, géométriques et dynamiques) sont introduits, et les différences entre les comportements à taille finie et à taille macroscopique sont précisées. Le phénomène de "coexistence dynamique", qui voit l'agrégat passer spontanément de l'état solide à l'état liquide (et réciproquement) au cours du temps, est illustré, et ses conséquences thermodynamiques sont soulignées. Enfin, nous présentons un certain nombre de phénomènes thermodynamiques liés à la taille finie, et dépendant fortement de la nature physico-chimique de la matière à ces échelles. Ces phénomènes sont étudiés à l'aide de simulations Monte Carlo ou de dynamique moléculaire, et sont, successivement: la fusion de surface observée sur des agrégats de gaz rares, la transition solide-liquide par étapes successives observée sur des agrégats ioniques, les spécificités de cette transition pour des agrégats moléculaires, et enfin le problème plus complexe des agrégats métalliques libres ou solvatés.

Calvo, F.

38

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

39

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

40

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, Sébastien; Kova?í?ek, Petr; Lehn, Jean-Marie; Samorì, Paolo

2014-11-01

41

Intermetallic Compound Formation Mechanisms for Cu-Sn Solid-Liquid Interdiffusion Bonding  

NASA Astrophysics Data System (ADS)

Cu-Sn solid-liquid interdiffusion (SLID) bonding is an evolving technique for wafer-level packaging which features robust, fine pitch and high temperature tolerance. The mechanisms of Cu-Sn SLID bonding for wafer-level bonding and three-dimensional (3-D) packaging applications have been studied by analyzing the microstructure evolution of Cu-Sn intermetallic compounds (IMCs) at elevated temperature up to 400°C. The bonding time required to achieve a single IMC phase (Cu3Sn) in the final interconnects was estimated according to the parabolic growth law with consideration of defect-induced deviation. The effect of predominantly Cu metal grain size on the Cu-Sn interdiffusion rate is discussed. The temperature versus time profile (ramp rate) is critical to control the morphology of scallops in the IMC. A low temperature ramp rate before reaching the bonding temperature is believed to be favorable in a SLID wafer-level bonding process.

Liu, H.; Wang, K.; Aasmundtveit, K. E.; Hoivik, N.

2012-09-01

42

A microfluidic setup for studies of solid-liquid interfaces using x-ray reflectivity and fluorescence microscopy  

NASA Astrophysics Data System (ADS)

In this paper we present a concept for a microfluidic chamber optimized for x-ray reflectivity studies at solid-liquid interfaces. Experiments of this kind are usually considerably limited by strong beam attenuation due to interactions with the aqueous environment. First experiments at synchrotron sources using supported model membranes showed that the microfluidic setup yields a very effective solution for minimizing background scattering and beam absorption, which are often accompanied by radiation damage of biological samples. Additionally, the setup is also well suited for the application of fluorescence microscopy. The application of these two different techniques on the same sample offers unique possibilities for complementary studies.

Reich, Christian; Hochrein, Marion B.; Krause, Bärbel; Nickel, Bert

2005-09-01

43

Probing Hydrophilic Interface of Solid/Liquid-Water by Nanoultrasonics  

PubMed Central

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 ångström 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. PMID:25176017

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

2014-01-01

44

Probing hydrophilic interface of solid/liquid-water by nanoultrasonics.  

PubMed

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 ångström 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. PMID:25176017

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

2014-01-01

45

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 ångström 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

46

Advanced Technology Development: Solid-Liquid Interface Characterization Hardware  

NASA Technical Reports Server (NTRS)

Characterizing the solid-liquid interface during directional solidification is key to understanding and improving material properties. The goal of this Advanced Technology Development (ATD) has been to develop hardware, which will enable real-time characterization of practical materials, such as aluminum (Al) alloys, to unprecedented levels. Required measurements include furnace and sample temperature gradients, undercooling at the growing interface, interface shape, or morphology, and furnace translation and sample growth rates (related). These and other parameters are correlated with each other and time. A major challenge was to design and develop all of the necessary hardware to measure the characteristics, nearly simultaneously, in a smaller integral furnace compatible with existing X-ray Transmission Microscopes, XTMs. Most of the desired goals have been accomplished through three generations of Seebeck furnace brassboards, several varieties of film thermocouple arrays, heaters, thermal modeling of the furnaces, and data acquisition and control (DAC) software. Presentations and publications have resulted from these activities, and proposals to use this hardware for further materials studies have been submitted as sequels to this last year of the ATD.

2003-01-01

47

Toward a detailed characterization of oil adsorbates as "solid liquids".  

PubMed

Solid lipid formulation systems are used to overcome oral bioavailability problems of poorly water-soluble drugs. One promising process is the conversion of a liquid lipid system in a free flowing powder by use of adsorbing excipients. The aim of this study was the detailed characterization of solid-liquid interactions in oil adsorbed to Fujicalin and Neusilin which were manufactured by means of dual asymmetric centrifugation or conventional mortar/pestle blending. The adsorption strength of the excipients was investigated by Benchtop-NMR and ESR spectroscopy revealing the highest adsorption power for the Neusilin products. The adsorbate production methods as well as the storage of the excipients impact their adsorption properties. Environmental scanning electron microscopy (ESEM) and confocal laser scanning microscopy (CLSM) show that dual asymmetric centrifugation leads to a smoothing of the particle surface, whereas the mortar/pestle blending results in an uneven surface and particle destruction. The oil distribution at the particles is inhomogeneous for both production methods. The micropolarity of the adsorbed oil was investigated by ESR spectroscopy and multispectral fluorescence imaging. The adsorbing process on Neusilin leads to an increased micropolarity of the oil component. The release of the oil component in aqueous media could be verified by Benchtop-NMR and multispectral fluorescence imaging. PMID:23275113

Kutza, Claudia; Metz, Hendrik; Kutza, Johannes; Syrowatka, Frank; Mäder, Karsten

2013-05-01

48

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

49

Recovery of phenolic compounds from grape seeds: effect of extraction time and solid–liquid ratio  

Microsoft Academic Search

The aim of this research was to study the recovery of phenolic compounds from grape seeds, by-products from winemaking industries, using ethanolic solid–liquid extraction. For such a purpose, the combined effects of the extraction time (9, 19 and 29?h) and the solid–liquid ratio (0.10, 0.20 and 0.30?gdw?mL), were investigated (where dw?=?dry waste). Results demonstrated that Pinot Noir seeds had high

Alessandro A. Casazza; Bahar Aliakbarian; Patrizia Perego

2011-01-01

50

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, Dérick

2010-02-01

51

Nanoscale thermal transport at solid-liquid interfaces  

NASA Astrophysics Data System (ADS)

This thesis focuses on the experimental study of nanoscale thermal transport across solidliquid interfaces in both nanoparticle system and planar thin film system. Thermal conductance of solid-liquid interfaces, G, will be measured using time-domain thermo-reflectance and pump-probe transient absorption. Interface thermal conductance, G, relates the temperature drop DeltaT at an interface to the flux of heat F that crosses the interface, F = GDeltaT. In nanoparticle systems, using pump-probe transient absorption measurement, we find that nanoparticles, ranging in size from 3-24 rim. with widely varying hydrophilic surface chemistry, give thermal conductances G ˜ 100-300 MW m-2 K-1 for the particle-water interfaces, approximately an order of magnitude larger than the conductance of the interfaces between alkanethiol-terminated AuPd nanoparticles and toluene. The relatively large thermal conductances between particle-water interfaces indicate that the thermal coupling between hydrophilic nanoparticles and water is strong regardless of the self-assembled stabilizing group. In planar systems, using time-domain thermoreflectance, we find that the thermal conductance between water and planar hydrophilic surfaces ranges between 100 and 180 MW m-2 K-1, which is in good agreement with the nanoparticles systems. While in hydrophobic-water interfaces, interface thermal conductance is smaller, ranging between 45 and 65 MW m-2 K-1 indicating that the thermal coupling between hydrophobic surfaces and water is weaker than with hydrophilic surfaces. The Kapitza length---the thermal conductivity of water divided by the thermal conductance per unit area of the interface---at hydrophobic interfaces (10-12 nm) is a factor of 2-3 larger than the Kapitza length at hydrophilic interfaces (3-6 nm). We also utilized the pump-probe transient absorption measurement to probe thermal transport in Au-core polymer-shell nanoparticles. The addition of an organic co-solvent to the suspension causes the polystyrene component of the polymer shell to swell and this change in the microstructure of the shell increases the effective thermal conductivity of the shell by a factor of approximately 2. The corresponding time-scale for the cooling of the nanoparticle decreases from 200 ps to approximately 100 ps.

Ge, Zhenbin

52

Determination of pesticides in lettuce using solid-liquid extraction with low temperature partitioning.  

PubMed

This work describes the optimization and validation of a method employing solid-liquid extraction with low temperature partitioning (SLE/LTP) together with analysis by gas chromatography with electron capture detection (GC/ECD) for the determination of nine pesticides (chlorothalonil, methyl parathion, procymidone, endosulfan, iprodione, ?-cyhalothrin, permethrin, cypermethrin, and deltamethrin) in lettuce. The method was found to be selective, accurate, and precise, with means recovery values in the range of 72.3-103.2%, coefficients of variation ?12%, and detection limits in the range 0.4-37?gkg(-1). The matrix components significantly influence the chromatographic response of the analytes (above 10%). The optimized and validated method was applied to determine the residual concentrations of the fungicides iprodione and procymidone that had been applied to field crops of lettuce. The maximum residual concentrations of the pesticides in the lettuce samples were 13.6±0.4mgkg(-1) (iprodione) and 1.00±0.01mgkg(-1) (procymidone), on the day after application of the products. PMID:25794722

Costa, Anna I G; Queiroz, Maria E L R; Neves, Antônio A; de Sousa, Flaviane A; Zambolim, Laércio

2015-08-15

53

Poly(phenylene Sulfide) (pps) Membrane Formation via Solid-Liquid Thermally Induced Phase Separation.  

NASA Astrophysics Data System (ADS)

Microporous polymeric membranes of improved thermal stability and chemical resistance were formed via Thermally Induced Phase Separation (TIPS) process. Specifically, poly(phenylene sulfide) (PPS) membranes were formed using 4-benzoylbiphenyl (BBP) as the diluent. The overall objective of the proposed research was to produce porous PPS membranes by the solid-liquid TIPS process. Specifically, the objective was to investigate the feasibility of controlling membrane structure by controlling the nucleation density ( eta). Control over eta (hence the morphology) was achieved by choosing proper combinations of process parameters, such as polymer concentration, dissolution temperature, crystallization temperature, dissolution time, and crystallization time. Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM) and optical microscopy (OM) were used to obtain the required data. A new mathematical model was developed to predict the eta for a polymer-diluent system. The new model overcomes the limitations imposed by the simplified Avrami equation. The new model differs from the classical Avrami theory in its treatment of the dependence of growth probabilities on the change in polymer concentration as crystallization develops. The theory includes treatment of both homogeneous and heterogeneous nucleation, arbitrary growth shapes (e.g., axialites), and secondary crystallization. With the developments presented in this dissertation, process engineers can easily select the correct process parameters to fulfill the specifications of microporous membranes for specific applications.

Chiang, Chung-Yuan

1995-01-01

54

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

55

Modélisation du cycle de vie d'un polluant en atmosphère : application aux oxydes d'azote (NO{X})  

NASA Astrophysics Data System (ADS)

Les problèmes de l'environnement nécessitent des modélisations particulièrement difficiles, mais d'une grande importance sociale. C'est un domaine récent, où les données sont encore peu nombreuses, mais où les attentes sont considérables, tant auprès du public que des politiques et des industriels. En effet, la modélisation consiste à définir un modèle qui permettra de représenter efficacement le processus étudié. Dans cette optique le comportement modélisé n'est que la manifestation extérieure d'une structure plus profonde. La complexité du système et du problème posé détermine celle du modèle, qui va de la simple représentation qualitative d'un comportement aux formules mathématiques les plus élaborées. Lorsque la modélisation est exprimée mathématiquement, on recourt généralement à un programme de simulation pour calculer le comportement prévisionnel du modèle. La compréhension du cycle de vie d'un polluant en atmosphère, dans notre cas les oxydes d'azote (NOX), nécessite la modélisation de l'évolution des réactifs et des produits en fonction du temps exprimée par des équations différentielles. La réalisation de la simulation à partir de ces modèles, nous permet de connaître l'ensemble des processus ayant lieu lors de l'émission du polluant en atmosphère jusqu'à sa consommation.

Hamzi, R.; Bourmada, N.; Benamrane, B. T.; Londiche, H.

2005-05-01

56

Influence of Melt Convection on Solid-Liquid Interface Under Terrestrial and Reduced Gravity Environments  

NASA Technical Reports Server (NTRS)

Solidification and crystal growth processes involve thermal and solutal gradients within a molten phase. In the presence of gravity, such gradients result in convective flows which interact with diffusion fields at the solid-liquid interface. Dendritic growth kinetics was studied in transparent model systems which freeze similarily to most metals. Succinonitrile shows a strong influence of convection at supercoolings below about 1K. Fluid flows adjacent to solid-liquid interfaces and the behavior of shear flows in vertical annular geometries are studied. Novel low-frequency eigenstates were discovered and classified as coupled modes, for their involvement with interfacial deformation coupled to the fluid flow, and are unknown in systems without deformable interfaces. The dependence of coupled convection modes on interfacial geometry, gravity, fluid properties, and transformation characteristics studied for several annual flow arrangements with nominally pure solid-liquid systems.

Glicksman, M. E.

1985-01-01

57

Phase and solute fields across the solid-liquid interface of a binary alloy.  

PubMed

Solidification of binary alloys is characterized by a sharp structural transition across the solid-liquid interface. It is a typical situation which suggests a nonlocal dependence of the appropriate thermodynamic potential on its associate fields. Phase-field models with a gradient contribution for the order parameter have proved to account for nonequilibrium effects, as solute trapping and kinetic undercooling of the solid-liquid interface. The inclusion of a gradient term for the concentration field has also been theoretically investigated, but in this case the correspondence between predicted phenomena and experimental results is still rather unexplored. In the present study we analyze numerical solutions of a phase-field model in both steady and transient conditions. We focus on effects which are critically dependent on the composition field across the solid-liquid interface; the extent of the concentration gradient correction is related to measurable quantities to suggest methods for a comparison between the model predictions and experimental data. PMID:11969981

Conti, M

1999-08-01

58

A Numerical Method for Multiphase Incompressible Thermal Flows with Solid-Liquid and Liquid-Vapor Phase Transformations  

Microsoft Academic Search

A numerical method for multiphase incompressible thermal flows with solid–liquid and liquid–vapor phase transformations is presented. The flow is mainly driven by thermocapillary force and vaporization. Based on the level set method and mixture continuum model, a set of governing equations valid for solid, liquid, and vapor phases is derived, considering phase boundary conditions as source terms in the transport

Hyungson Ki; Pravansu S. Mohanty; Jyoti Mazumder

2005-01-01

59

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

60

On the Maximal Deviation from the Mirror Image Approximation due to Solid Liquid Phase Transition  

NASA Astrophysics Data System (ADS)

We extend the Walsh and Christian (1955) analysis in a manner which allows a reasonable estimation of the expected deviation from the mirror image approximation due to solid liquid phase transition. This estimate is limited to a phase transition that occurs at shock unloading. This analysis provides a good estimate to metals with low melting pressure such as Tin and Lead.

Pistinner, S. L.; Pecker, S.; Werdiger, M.; Eliezer, S.

2007-12-01

61

Solid-Liquid and Liquid-Liquid Mixing Laboratory for Chemical Engineering Undergraduates  

ERIC Educational Resources Information Center

Solid-liquid and liquid-liquid mixing experiments have been developed to provide students with a practical experience on suspension and emulsification processes. The laboratory focuses on the characterization of the process efficiency, specifically the influence of the main operating parameters and the effect of the impeller type. (Contains 2…

Pour, Sanaz Barar; Norca, Gregory Benoit; Fradette, Louis; Legros, Robert; Tanguy, Philippe A.

2007-01-01

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

Mathematics and Mechanics of Solids (to appear) Mathematical Modelling of a SolidLiquid  

E-print Network

soil mechanics, soil consolidation under loading, ground water hydrology, petroleum engineeringMathematics and Mechanics of Solids (to appear) Mathematical Modelling of a Solid­Liquid Mixture, Dipartimento di Matematica, Corso Duca degli Abruzzi 24, 10129 Torino, Italy Abstract The mechanical behavior

Ambrosi, Davide

65

New materials for solar thermal storage—solid\\/liquid transitions in fatty acid esters  

Microsoft Academic Search

Solid\\/liquid transitions were studied by DSC measurements in the following fatty acid esters: methyl stearate, methyl palmitate, cetyl stearate, cetyl palmitate and their binary mixtures. Four systems, with phase transition temperature close to room temperature and with high enthalpy of transition and low hysteresis, were selected for further studies relevant to passive solar thermal storage. The selected systems were: methyl

R Nikoli?; M Marinovi?-Cincovi?; S Gadžuri?; I. J Zsigrai

2003-01-01

66

Investigations of Polyelectrolyte Adsorption at the Solid/ Liquid Interface by Sum Frequency Spectroscopy: Evidence  

E-print Network

of monolayer and multilayer films have focused on the preparation of well-ordered structures. The goalsInvestigations of Polyelectrolyte Adsorption at the Solid/ Liquid Interface by Sum Frequency of the positively charged polyelectrolyte, polydiallyldimethylammonium chloride (PDDA), at the quartz

67

Dynamics of polarization relaxation in a dipolar mixture at a solid-liquid interface  

Microsoft Academic Search

Dynamics of polarization relaxation in a dipolar mixture at solid-liquid interface is investigated theoretically by using time dependent density functional theory. The time dependence of the building up of polarization of different dipolar species next to a newly charged solid surface is calculated by solving both Markovian and non-Markovian equations of motion for density and momentum variables. The inhomogeneity of

Sanjib Senapati; Amalendu Chandra

2000-01-01

68

Enhanced solid-liquid separation of dairy manure with natural flocculants  

Technology Transfer Automated Retrieval System (TEKTRAN)

Natural flocculants have potential to replace the use of synthetic flocculants used for enhanced solid-liquid separation of livestock effluents, especially with increased cost of energy and renewed interest on organic farming systems. We conducted a study to determine the effectiveness of natural fl...

69

Molecular Dynamics Simulations of Surfactant Self-Organization at a Solid-Liquid Interface  

E-print Network

Molecular Dynamics Simulations of Surfactant Self-Organization at a Solid-Liquid Interface Goundla: Self-organization of aqueous surfactants at a planar graphite-like surface is studied by means of coarse-grain molecular dynamics simulations. The nonionic surfactant, n-alkyl poly(ethylene oxide

Nielsen, Steven O.

70

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

71

Lift correlations from direct numerical simulation of solid liquid flow  

NASA Astrophysics Data System (ADS)

We studied the levitation of 300 particles in a Poiseuille flow and created a data bank which when plotted on a log-log plot give rise to straight lines. This is to say that lift results for fluidized slurries are power laws in appropriate dimensionless parameters. This shows that fluidization of slurries by lift also fall into enabling correlations of the Richardson-Zaki type. The method of correlations is a link between direct simulation and engineering application.

Joseph, Daniel D.; Patankar, Neelesh; Ko, T.; Choi, H.

2000-11-01

72

Numerical formulation of composition segregation at curved solid-liquid interface during steady state solidification process  

NASA Technical Reports Server (NTRS)

The lateral solute segregation that results from a curved solid-liquid interface shape during steady state unidirectional solidification of a binary alloy system has been studied both analytically and numerically by Coriell, Bosivert, Rehm, and Sekerka. The system under their study is a two dimensional rectangular system. However, most real growth systems are cylindrical systems. Thus, in a previous study, we have followed Coriell etc. formalism and obtained analytical results for lateral solute segregation for an azimuthal symmetric cylindrical binary melt system during steady state solidification process. The solid-liquid interface shape is expressed as a series combination of Bessel functions. In this study a computer program has been developed to simulate the lateral solute segregation.

Wang, Jai-Ching

1994-01-01

73

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

74

Numerical simulation of solid liquid interface behavior during continuous strip casting process.  

PubMed

A new metal-strip-casting process called continuous strip-casting (CSC) has been developed for making thin metal strips. A numerical simulation model to help understand solid-liquid interface behavior during CSC has been developed and used to identify the solidification morphologies of the strips and to determine the optimum processing conditions. In this study, we used a modified level contour reconstruction method (LCRM) and the sharp interface method to modify interface tracking, and performed a simulation analysis of the CSC process. The effects of process parameters such as heat-transfer coefficient and extrusion velocity on the behavior of the solid-liquid interface were estimated and used to improve the apparatus. A Sn (Tin) plate of dimensions 200 x 50 x 1 mm3 was successfully produced by CSC for a heat-transfer coefficient of 104 W/m2 K and an extrusion velocity of 0.2 m/s. PMID:23858856

Lee, Changbum; Yoon, Wooyoung; Shin, Seungwon; Lee, Jaewoo; Jang, Bo-Yun; Kim, Joonsoo; Ahn, Youngsoo; Lee, Jinseok

2013-05-01

75

Comparative study of turbulent solid–liquid extraction methods for the determination of organochlorine pesticides  

Microsoft Academic Search

The aim of any extraction method in analytical chemistry is to effectively separate the analytes from the matrix with minimal solvent and time required. In this study, a comparison of the classical Soxhlet extraction and some new turbulent solid–liquid extraction techniques, such as fluidized-bed extraction (FBE), modified dive-in fluidized-bed extraction (dive-in FBE), modified dive-in Soxhlet extraction (dive-in SE) and dive-in

Donata Bandoniene; Marion Gfrerer; Ernst P. Lankmayr

2004-01-01

76

Study of solid–liquid mixing in agitated tanks through electrical resistance tomography  

Microsoft Academic Search

Electrical resistance tomography (ERT), which is a non-intrusive flow visualization technique, was used to investigate the solid–liquid mixing in an agitated tank equipped with a top-entering axial-flow impeller. The signals obtained from eight ERT planes were utilized to reconstruct the tomograms by using the linear back projection algorithm. The ERT measurements were correlated to solid concentration profiles by which the

Seyed Hosseini; Dineshkumar Patel; Farhad Ein-Mozaffari; Mehrab Mehrvar

2010-01-01

77

Behavior of ceramic particles at the solid- liquid metal interface in metal matrix composites  

Microsoft Academic Search

Directional solidification experiments have been conducted to document SiC particle behavior at the solid-liquid interface\\u000a in Al-2 pct Mg (cellular interface) and Al-6.1 pct Ni (eutectic interface) alloys. Particle size ranged from 20 to 150 ?m\\u000a diameter. Although predictions based on the thermodynamic approach suggest that no engulfment is possible, it was demonstrated\\u000a that particles can be entrapped in the

D. M. Stefanescu; B. K. Dhindaw; S. A. Kacar; A. Moitra

1988-01-01

78

A three-phase ternary model for CO 2-Solid-Liquid equilibrium at moderate pressures  

Microsoft Academic Search

In this work, we present a simple, totally predictive, three-phase modeling for systems containing CO2-solid-liquid for evaluation of cosolvents in the supercritical-fluid extraction (SCFE) of volatile matter of Brazilian mineral coals. The liquid phase is modeled by the traditional regular solution theory while the gas phase is represented by the Peng-Robinson\\/Stryjek-Vera equation of state and the heavy component is taken

Sandro R. P. da Rocha; José V. de Oliveira; Saul G. d' Ávila

1996-01-01

79

Experimental study of solid–liquid phase change in a spiral thermal energy storage unit  

Microsoft Academic Search

A new idea on the use of a vertical spiral heat exchanger in a latent heat thermal energy storage system is analyzed experimentally. In this context, two important subjects are addressed. The first one is the temporal behavior of a phase change medium undergoing a non-isothermal solid–liquid phase change transition during its two-side heating or cooling by a working fluid

J Banaszek; R Domañski; M Rebow; F El-Sagier

1999-01-01

80

Biodegradation of a phenolic mixture in a solid–liquid two-phase partitioning bioreactor  

Microsoft Academic Search

A solid–liquid two-phase partitioning bioreactor (TPPB) in which the non-aqueous phase consisted of polymer (HYTREL) beads was used to degrade a model mixture of phenols [phenol, o-cresol, and 4-chlorophenol (4CP)] by a microbial consortium. In one set of experiments, high concentrations (850 mg l?1 of each of the three substrates) were reduced to sub-inhibitory levels within 45 min by the addition of

George P. Prpich; Andrew J. Daugulis

2006-01-01

81

Solid-liquid phase equilibria at 727 °C in the ternary system Fe-Mg-Si  

Microsoft Academic Search

The solid-liquid phase equilibria in the Fe-Mg-Si ternary system were experimentally investigated at 727 °C by two complementary\\u000a approaches: reaction to equilibrium of Fe-Mg-Si powder mixtures and growth of reaction zones at the interface of diffusion\\u000a couples. X-ray powder diffraction, optical metallography (OM), scanning electron microscopy (SEM), and electron probe microanalysis\\u000a (EPMA) were used to characterize the phases formed in

D. Pierre; M. Peronnet; F. Bosselet; J. C. Viala; J. Bouix

2000-01-01

82

Equilibrium at stationary solid-liquid interface during phase-field modeling of alloy solidification  

Microsoft Academic Search

The phase-field parameters (coefficient of gradient energy and double-well potential height) were obtained for a binary solid-liquid (SL) interface with a finite thickness (thin interface). The parameters were compared with those obtained at a sharp interface condition in order to test the maintenance of equilibrium condition at a stationary SL interface. The phase-field parameters determined at the thin interface condition

Won Tae Kim; Seong Gyoon Kim; Jai Sang Lee; Toshio Suzuki

2001-01-01

83

Equilibrium at stationary solid-liquid interface during phase-field modeling of alloy solidification  

Microsoft Academic Search

The phase-field parameters (coefficient of gradient energy and double-well potential height) were obtained for a binary solid-liquid\\u000a (SL) interface with a finite thickness (thin interface). The parameters were compared with those obtained at a sharp interface\\u000a condition in order to test the maintenance of equilibrium condition at a stationary SL interface. The phase-field parameters\\u000a determined at the thin interface condition

Won Tae Kim; Seong Gyoon Kim; Jai Sang Lee; Toshio Suzuki

2001-01-01

84

Electrical impedance tomography spectroscopy method for characterising particles in solid-liquid phase  

SciTech Connect

Electrical impedance tomography (EIT) is one of the process tomography techniques to provide an on-line non-invasive imaging for multiphase flow measurement. With EIT measurements, the images of impedance real part, impedance imaginary part, phase angle, and magnitude can be obtained. However, most of the applications of EIT in the process industries rely on the conductivity difference between two phases in fluids to obtain the concentration profiles. It is not common to use the imaginary part or phase angle due to the dominant change in conductivity or complication in the use of other impedance information. In a solid-liquid two phases system involving nano- or submicro-particles, characterisation of particles (e.g. particle size and concentration) have to rely on the measurement of impedance phase angle or imaginary part. Particles in a solution usually have an electrical double layer associated with their surfaces and can form an induced electrical dipole moment due to the polarization of the electrical double layer under the influence of an alternating electric field. Similar to EIT, electrical impedance spectroscopy (EIS) measurement can record the electrical impedance data, including impedance real part, imaginary part and phase angle (?), which are caused by the polarization of the electrical double layer. These impedance data are related to the particle characteristics e.g. particle size, particle and ionic concentrations in the aqueous medium, therefore EIS method provides a capability for characterising the particles in suspensions. Electrical impedance tomography based on EIS measurement or namely, electrical impedance tomography spectroscopy (EITS) could image the spatial distribution of particle characteristics. In this paper, a new method, including test set-up and data analysis, for characterisation of particles in suspensions are developed through the experimental approach. The experimental results on tomographic imaging of colloidal particles based on EIS measurement using a sensor of 8 electrodes are reported. Results have demonstrated the potential as well as revealed the challenge in the use of EIS and EITS for characterisation of particle in suspension.

Zhao, Yanlin [Department of Thermal Energy Engineering, College of Mechanical and Transportation Engineering, China University of Petroleum, Beijing, 102249 (China); Wang, Mi [Institute of Particle Science and Engineering, School of Process, Environmental and Materials Engineering, University of Leeds, Leeds LS2 9JT (China); Yao, Jun [School of Energy Research, Xiamen University, Xiamen 361005 (China)

2014-04-11

85

Electrical impedance tomography spectroscopy method for characterising particles in solid-liquid phase  

NASA Astrophysics Data System (ADS)

Electrical impedance tomography (EIT) is one of the process tomography techniques to provide an on-line non-invasive imaging for multiphase flow measurement. With EIT measurements, the images of impedance real part, impedance imaginary part, phase angle, and magnitude can be obtained. However, most of the applications of EIT in the process industries rely on the conductivity difference between two phases in fluids to obtain the concentration profiles. It is not common to use the imaginary part or phase angle due to the dominant change in conductivity or complication in the use of other impedance information. In a solid-liquid two phases system involving nano- or submicro-particles, characterisation of particles (e.g. particle size and concentration) have to rely on the measurement of impedance phase angle or imaginary part. Particles in a solution usually have an electrical double layer associated with their surfaces and can form an induced electrical dipole moment due to the polarization of the electrical double layer under the influence of an alternating electric field. Similar to EIT, electrical impedance spectroscopy (EIS) measurement can record the electrical impedance data, including impedance real part, imaginary part and phase angle (?), which are caused by the polarization of the electrical double layer. These impedance data are related to the particle characteristics e.g. particle size, particle and ionic concentrations in the aqueous medium, therefore EIS method provides a capability for characterising the particles in suspensions. Electrical impedance tomography based on EIS measurement or namely, electrical impedance tomography spectroscopy (EITS) could image the spatial distribution of particle characteristics. In this paper, a new method, including test set-up and data analysis, for characterisation of particles in suspensions are developed through the experimental approach. The experimental results on tomographic imaging of colloidal particles based on EIS measurement using a sensor of 8 electrodes are reported. Results have demonstrated the potential as well as revealed the challenge in the use of EIS and EITS for characterisation of particle in suspension.

Zhao, Yanlin; Wang, Mi; Yao, Jun

2014-04-01

86

Sonochemical reactions: Mass transfer and kinetic studies of a solid-liquid system  

NASA Astrophysics Data System (ADS)

Ultrasound has been shown to have desirable effects on both homogeneous and heterogeneous reactions, such as increasing the conversion, enhancing the selectivity, and improving the yield. Enhancements due to ultrasound may be attributed to chemical effects or mechanical effects, or to both simultaneously. The chemical effects of ultrasound are attributed to the implosion of microbubbles, generating free-radicals with a great propensity for reaction. Mechanical effects are caused by shock waves formed during symmetric cavitation, or by microjets formed when the bubble implodes asymmetrically. Research emphasis in this area attempts to discern the mechanisms behind ultrasound's mechanical effects by selecting a model solid-liquid noncatalytic reacting system in which the chemical effects of ultrasound are negligible. A rigorous kinetic modeling approach is used which allows for reaction in both the liquid and solid phases. After an extensive analysis of the experimental data obtained from the system, it is concluded that the reaction occurs on the solid phase, and that the liquid phase reaction is negligible. Using several investigative techniques, the expected effects of ultrasound were observed, such as the degradative effects on particle size leading to increased surface area. More importantly, some novel findings of the effects of ultrasound on mass transfer parameters are reported. Results clearly show that ultrasound enhances the intrinsic mass transfer coefficient as well as the effective diffusivity of an organic reactant through the ionic lattice of the product layer. In addition, ultrasound also induces supersaturation of solid sodium sulfide in the solvent acetonitrile, increasing the solubility by a factor of 1.4 over the equilibrium saturation concentration. This enhanced solubility is attributed to cavitation which creates localized hot spots containing solvent in a supercritical state. The normally sparingly soluble solid is highly soluble in the solvent when it exists as a supercritical fluid. The increased solubility in these localized area has 'memory' and is retained, even after the hot-spot dissipates into the bulk liquid. The use of ultrasound to induce supersaturation has significant applications in the areas of chemical kinetics when the reaction occurs in the liquid film or the bulk liquid phase.

Hagenson, Leigh Christine

1997-12-01

87

Linear morphological stability analysis of the solid-liquid interface in rapid solidification of a binary system.  

PubMed

The interface stability against small perturbations of the planar solid-liquid interface is considered analytically in linear approximation. Following the analytical procedure of Trivedi and Kurz [Acta Metall. 34, 1663 (1986)

Galenko, P K; Danilov, D A

2004-05-01

88

A model of blind zone for in situ monitoring the solid/liquid interface using ultrasonic wave.  

PubMed

To in situ monitor a solid/liquid interface to control metal qualities, the paper analysis blind models of the ultrasonic propagation in the solidifying molten metal with a solid/liquid interface in the Bridgman type furnace, and a mathematical calculation model of blind zone with different source locations and surface concavities is built. The study points out that the blind zone I is caused by ray bending in the interface edge, and the blind zone II is caused by totally reflection which is related with initial ray angle, critical refraction angle of solid/liquid media. A serial of simulation experiments are operated on the base of the model, and numerical computation results coincide with model calculated results very well. Therefore, receiver should locate beyond these blind zones in the right boundary to obtain time of flight data which is used to reconstruct the solid/liquid interface. PMID:25783779

Peng, Song; Ouyang, Qi; Zhu, Z Z; Zhang, X L

2015-07-01

89

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

90

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

91

Distribution of solute at solid-liquid interface during solidification of melt  

NASA Astrophysics Data System (ADS)

A model for predicting a distribution coefficient (ki) of solute at the solid-liquid (S-L) interface, when the solid layer is growing, is proposed. The interfacial distribution coefficient is expressed as a function of two gradients of the liquid concentration and equilibrium concentration at the S-L interface. The model is applied to the solidification of a simple eutectic binary liquid of lauric acid and myristic acid in an enclosed rectangular box in which a vertical wall is cooled. The impurity-concentration profile in solid is predicted from the direct numerical computations.

Fukui, Keisuke; Maeda, Kouji

1998-11-01

92

Surface-induced selection during in?situ photoswitching at the solid/liquid interface.  

PubMed

Here we report for the first time a submolecularly resolved scanning tunneling microscopy (STM) study at the solid/liquid interface of the in?situ reversible interconversion between two isomers of a diarylethene photoswitch, that is, open and closed form, self-assembled on a graphite surface. Prolonged irradiation with UV light led to the in?situ irreversible formation of another isomer as by-product of the reaction, which due to its preferential physisorption accumulates at the surface. By making use of a simple yet powerful thermodynamic model we provide a quantitative description for the observed surface-induced selection of one isomeric form. PMID:25728405

Bonacchi, Sara; El Garah, Mohamed; Ciesielski, Artur; Herder, Martin; Conti, Simone; Cecchini, Marco; Hecht, Stefan; Samorì, Paolo

2015-04-13

93

An enthalpy-based lattice Boltzmann model for diffusion dominated solid liquid phase transformation  

NASA Astrophysics Data System (ADS)

An extended lattice Boltzmann (LB) formulation is developed for simulation of three-dimensional heat diffusion, coupled with solid liquid phase transition aspects. Thermodynamic variables are obtained through the evolution equation of a single particle distribution function. Phase change aspects are tackled by an enthalpy-based approach. The proposed model is subsequently utilized to simulate a generic laser surface melting process and compared with the continuum model results obtained by solving the governing equation for energy transport. The comparison shows a potentiality of the developed LB method to solve phase change problems in a computationally effective and convenient manner.

Chatterjee, Dipankar; Chakraborty, Suman

2005-06-01

94

Solid-liquid composite structures: elastic beams with embedded liquid-filled parallel-channel networks  

E-print Network

Deformation due to embedded fluidic networks is currently studied in the context of soft-actuators and soft-robotics. Expanding on this concept, beams can be designed so that the pressure in the channel-network is created directly from external forces acting on the beam, and thus can be viewed as passive solid-liquid composite structure. We obtain a continuous function relating the network geometry to the deformation. This enables design of networks creating arbitrary steady and time varying deformation-fields as well as to eliminate deformation created by external forces.

Yoav Matia; Amir Gat

2014-09-07

95

Its Just a Phase: Water as a Solid, Liquid, and Gas  

NSDL National Science Digital Library

In this lesson, students will construct models of the way water molecules arrange themselves in the three physical states. They will come to understand that matter can be found in three forms or phases (solid, liquid, and gas). Using physical models, students will be able to explain the molecular behavior of ice, water, and water vapor. The instructor guide contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.

96

Stir-membrane solid-liquid-liquid microextraction for the determination of parabens in human breast milk samples by ultra high performance liquid chromatography-tandem mass spectrometry.  

PubMed

In this article, stir-membrane solid-liquid-liquid microextraction (SM-SLLME) is tailored for the analysis of solid matrices and it has been evaluated for the determination of parabens in l breast milk samples. A three-phase microextraction mode was used for the extraction of the target compounds taking advantage of their acid-base properties. The unit allows the simultaneous extraction of the target compounds from the solid sample to an organic media and the subsequent transference of the analytes to an aqueous acceptor phase. The method includes the identification and quantification of the analytes by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). All the variables involved in the extraction procedure have been accurately studied and optimized. The analytes were detected and quantified using a triple quadrupole mass spectrometer (QqQ). The selection of two specific fragmentation transitions for each compound allowed simultaneous quantification and identification. The method has been analytically characterized on the basis of its linearity, sensitivity and precision. Limits of detection ranged from 0.1 to 0.2ngmL(-1) with precision better than 8%, (expressed as relative standard deviation). Relative recoveries were in the range from 91 to 106% which demonstrated the applicability of the stir-membrane solid-liquid-liquid microextraction for the proposed analytical problem. Moreover, the method has been satisfactorily applied for the determination of parabens in lyophilized breast milk samples from 10 randomly selected individuals. PMID:24935266

Rodríguez-Gómez, Rocío; Roldán-Pijuán, Mercedes; Lucena, Rafael; Cárdenas, Soledad; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Valcárcel, Miguel

2014-08-01

97

Comparison of the different responses of surface plasmon resonance and quartz crystal microbalance techniques at solid-liquid interfaces under various experimental conditions.  

PubMed

A molecular level understanding of the phenomena taking place at solid-liquid interfaces, ranging from changes in mass to conformation changes, is the key to developing and improving many chemical and biological systems and their scientific and medical applications. Surface plasmon resonance (SPR) and quartz crystal microbalance (QCM) techniques are often coupled to achieve this understanding. We divided various experimentally relevant scenarios into the following six categories: boundary solutions; surface modifications; conformation; viscoelastic properties; molecular ruler; and mass sensitivity. For each case, based on theoretical analyses, we discuss the following four points with respect to discrete adsorbates at solid-liquid interfaces: (1) the different types of information that can be obtained, why it can be obtained and how to obtain it; (2) the origins of many current approaches and why they are imperfect; (3) guidelines for experimental design; and (4) possible studies, such as the effect of dimensional confinement and adsorption forces on the ability of conformational changes to occur on the receipt of external stimuli and the hysteresis in these changes. PMID:25575354

Fang, Jiajie; Ren, Chunlai; Zhu, Tao; Wang, Kaiyu; Jiang, Zhongying; Ma, Yuqiang

2015-02-21

98

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

99

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, Agustín; Sousa, Marilyne; Martín, Nazario; Gotsmann, Bernd; Riel, Heike

2014-10-01

100

Evaluation and ranking of the tank focus area solid liquid separation needs  

SciTech Connect

The Tank Focus Area (TFA) of the Department of Energy (DOE) Office of Environmental Restoration and Waste Management (EM) addresses remediation of liquid waste currently stored in underground tanks. Several baseline technologies for treatment of tank waste can be categorized into three types of solid liquid separation: (a) removal of radioactive species that have been absorbed or precipitated, (b) pretreatment for ion exchange, and (c) volume reduction of sludge and wash water. The solids formed from precipitation or absorption of radioactive ions require separation from the liquid phase to permit treatment of the liquid as Low Level Waste. Prior to ion exchange of radioactive ions, removal of insoluble solids is needed to prevent bed fouling and downstream contamination. Volume reduction of washed sludge solids would reduce the tank space required for interim storage. The scope of this document is to evaluate the solid/liquid separations needed to permit treatment of tank wastes to accomplish these goals. The document summarizes previous alkaline waste testing, with an emphasis on crossflow filtration, to-obtain a general understanding of the behavior of radioactive wastes on available equipment. The document also provides general information about filtration and a path forward for testing.

McCabe, D.J.

1995-08-17

101

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

SciTech Connect

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 [Division of Materials Science and Engineering, Boston University, Brookline, Massachusetts 02446 (United States); Kim, Jaegil; Straub, John E., E-mail: straub@bu.edu [Department of Chemistry, Boston University, Boston, Massachusetts 02215 (United States); Farrell, James D.; Wales, David J. [University Chemical Laboratories, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

2014-11-14

102

Double multiple-relaxation-time lattice Boltzmann model for solid-liquid phase change with natural convection in porous media  

E-print Network

In this paper, a double multiple-relaxation-time lattice Boltzmann model is developed for simulating transient solid-liquid phase change problems in porous media at the representative elementary volume scale. The model uses two different multiple-relaxation-time lattice Boltzmann equations, one for the flow field and the other for the temperature field with nonlinear latent heat source term. The model is based on the generalized non-Darcy formulation, and the solid-liquid phase change interface is traced through the liquid fraction which is determined by the enthalpy method. The model is validated by numerical simulations of conduction melting in a semi-infinite space, solidification in a semi-infinite corner, and convection melting in a square cavity filled with porous media. The numerical results demonstrate the efficiency and accuracy of the present model for simulating transient solid-liquid phase change problems in porous media.

Liu, Qing

2015-01-01

103

Dependence of solid-liquid interface free energy on liquid structure  

SciTech Connect

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 [Ames Laboratory; Mendelev, M I [Ames Laboratory

2014-09-01

104

Molecular Dynamics Simulation of Argon in Solid-Liquid Phase Transition Region  

NASA Astrophysics Data System (ADS)

The microstructure of 256 argon atoms located on ideal fcc lattice sites on which periodic boundary conditions have been applied at the vicinity of transition temperature has been investigated. The forces among atoms have been derived from Lennard-Jones potential energy function and the equations of motion of the system have been solved by using the Verlet algorithm. The variations in microstructure have been investigated by means of radial distribution function and real-space atomic trajectories. It has been found from the results of simulation at zero pressure that solid-liquid transition temperature is 86K, the change of enthalpy is 1202 J/mol and relative volume change is 0.14.

Özgen, Soner; Kuzucu, Veysel; Adigüzel, Osman

1997-10-01

105

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

106

Effects of Solid-Liquid Mixing on Microstructure of Semi-Solid A356 Aluminum Alloy  

NASA Astrophysics Data System (ADS)

The desired starting material for semi-solid processing is the semi-solid slurry in which the solid phase is present as fine and globular particles. A modified solid-liquid mixing (SLM) is reported wherein semi-solid slurry can be produced by mixing a solid alloy block into a liquid alloy, and mechanical vibration is utilized to enhance the mixing. Effects such as liquid alloy temperature, mass ratio, and mixing intensity on the microstructure and the cooling curves during SLM were evaluated. 2D and 3D microstructure analysis of treated A356 aluminum alloy shows that microstructure can be refined significantly with a considerable morphology change in primary Al phase. It is critical that the temperature of mixture after mixing is lower than its liquidus temperature to obtain a valid SLM process. Specially, mixing intensity is identified as a primary factor for a favorable microstructure of semi-solid slurry.

Guo, H. M.; Wang, L. J.; Wang, Q.; Yang, X. J.

2014-08-01

107

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 278±13 and 289±1LkgVS(-1), while in term of fresh weigh substrate were 59±2.8 and 59±0.3Lkgsubstrate(-1), respectively. PMID:23313767

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

2013-02-01

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

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

SciTech Connect

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.; Baque, F. [CEA, DEN, Nuclear Technology Department, F-13108 Saint-Paul-lez-Durance (France); Moysan, J.; Corneloup, G. [Laboratoire de Caracterisation Non Destructive, Universite de la Mediterranee, IUT Aix-en-Provence, Avenue Gaston Berger, 13625 Aix-en-Provence (France); Chatain, D. [CNRS, Aix-Marseille Universite, CINAM-UPR3118, Campus de Luminy, Case 913, 13288 Marseille cedex 09 (France)

2011-08-15

110

Design and Testing of a Solid-Liquid Interface Monitor for High-Level Waste Tanks  

SciTech Connect

A high-level waste (HLW) monitor has been designed, fabricated and tested at full-scale for deployment inside a Hanford tank. The Solid-Liquid Interface Monitor (SLIM) integrates a commercial sonar system with a mechanical deployment system for deploying into an underground waste tank. The system has undergone several design modifications based upon changing requirements at Hanford. We will present the various designs of the monitor from first to last and will present performance data from the various prototype systems. We will also present modeling of stresses in the enclosure under 85 mph wind loading. The system must be able to function at winds up to 15 mph and must withstand a maximum loading of 85 mph. There will be several examples presented of engineering tradeoffs made as FIU analyzed new requirements and modified the design to accommodate. We will present our current plans for installing into the Cold Test Facility at Hanford and into a double-shelled tank at Hanford. Finally, we will present our vision for how this technology can be used at Hanford and Savannah River Site to improve the filling and emptying of high-level waste tanks. In conclusion: 1. The manually operated first-generation SLIM is a viable option on tanks where personnel are allowed to work on top of the tank. 2. The remote controlled second-generation SLIM can be utilized on tanks where personnel access is limited. 3. The totally enclosed fourth-generation SLIM, when the design is finalized, can be used when the possibility exists for wind dispersion of any HLW that maybe on the system. 4. The profiling sonar can be used effectively for real-time monitoring of the solid-liquid interface over a large area. (authors)

McDaniel, D.; Awwad, A.; Roelant, D.; Srivastava, R. [Applied Research Center, Florida International University, Miami, FL (United States)

2008-07-01

111

Catalytic growth of nanowires: Vapor–liquid–solid, vapor–solid–solid, solution–liquid–solid and solid–liquid–solid growth  

Microsoft Academic Search

Catalytic growth is a powerful tool to form a variety of wire (whisker) like structures with diameters ranging from just a few nanometres to the millimetre range. A range of phases (gas, solid, liquid, solution and supercritical fluid) have been used for the feeder phase, i.e. the source of material to be incorporated into the nanowire. Solid, liquid, eutectic, alloy

Kurt W. Kolasinski

2006-01-01

112

Chemical Spills, Releases, Explosions, Exposures, or Injuries (includes corrosive, reactive, flammable, and toxic chemicals in solid, liquid or gas form)  

E-print Network

Chemical Spills, Releases, Explosions, Exposures, or Injuries (includes corrosive, reactive, flammable, and toxic chemicals in solid, liquid or gas form) EHS Contact: Kate Lumley-Sapanski (kxl3@psu be immediately reported to EHS after emergency procedures have been implemented. · All spills

Maroncelli, Mark

113

Polymer Development for Enhanced Delivery of Phenol in a Solid-Liquid Two-Phase Partitioning Bioreactor  

E-print Network

Polymer Development for Enhanced Delivery of Phenol in a Solid-Liquid Two-Phase Partitioning liquid TPPBs to the use of pure strains of microbes. Solid polymer beads have recently been introduced to be used with mixed microbial populations. The present work was aimed at identifying a polymer

Daugulis, Andrew J.

114

Chemical Engineering Science 55 (2000) 4993}5001 A further study of solid}liquid equilibrium for the  

E-print Network

Chemical Engineering Science 55 (2000) 4993}5001 A further study of solid}liquid equilibrium Shi , Benjamin C. -Y. Lu Department of Chemical Engineering, Nanjing University of Chemical Technology, Nanjing 210009, People's Republic of China Department of Chemical Engineering, University of Ottawa

Zhang, Luzheng

2000-01-01

115

Auxin modulates the degradation rate of Aux/IAA proteins.  

PubMed

Aux/IAA gene family members were first identified by their rapid transcriptional increase in response to auxin. Auxin/indole-3-acetic acid protein (Aux/IAA) luciferase (LUC) fusions expressed in Arabidopsis under control of a non-auxin-responsive promoter were used to monitor the effect of auxin on protein abundance independent of transcriptional regulation by auxin. After 2 hr in the presence of 1 microM exogenous dichlorophenoxyacetic acid (2,4D), a synthetic auxin, the levels of pea IAA6 (PSIAA6) and Arabidopsis IAA1 LUC activity were 35% and 67%, respectively, of mock-treated genetically identical seedlings, whereas the activity of LUC alone from equivalently treated seedlings remained unaltered. The steady-state level of an Aux/IAA fusion protein lacking domain II, one of the conserved domains found in all Aux/IAA proteins, was not reduced in the presence of auxin. Higher levels of exogenous auxin were required to affect the steady-state level of the PSIAA6LUC fusion with a point mutation in domain II. A 13-aa consensus sequence from domain II fused to LUC created an auxin-responsive fusion protein. The change in steady-state levels in response to auxin is extremely rapid, with a decrease in LUC activity detectable by 2 min after auxin application. Direct half-life measurements show that the decrease caused by exogenous auxin is due to the decrease in fusion protein half-life. These results suggest that auxin rapidly modulates the degradation rate of Aux/IAA proteins, with higher levels of auxin increasing the proteolytic rate of Aux/IAA family members. PMID:11573012

Zenser, N; Ellsmore, A; Leasure, C; Callis, J

2001-09-25

116

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

117

Solid-liquid separation of oxidized americium from fission product lanthanides  

NASA Astrophysics Data System (ADS)

The separation of americium from the lanthanides and curium is a requirement if transmutation of americium is to be performed in advanced nuclear fuel cycles. Oxidation of Am3+ to AmO2+ or AmO22+ may allow separation of Am from Ln and Cm in one step, since the lanthanides and curium do not have higher oxidation states as accessible. Two possible solid-liquid separation methods have been developed to address this difficult separation. Under acidic conditions using oxone or persulfate, the oxidation and retention of tracer Am in the aqueous phase has been observed with a separation factor of 11 ± 1. Most of these studies have been conducted using 237NpO2(NO3), 233UO2(NO3)2, 238Pu(NO3)4 and 241Am(NO3)3 at radiotracer concentrations. Lanthanides precipitate as the sodium or potassium europium double sulfate salt. Under basic conditions, ozone oxidation of Am(CO3)OH(s) solubilizes Am from a lanthanide carbonate hydroxide solid phase to the aqueous phase as the AmO2(CO3)34-or AmO2(CO3)35- species. For the ozone oxidation of the americium tracer a separation factor of 1.6 ± 0.8 and 47 ± 2 for the oxidation/separation in Na2CO3 and NaHCO3 respectively.

Shehee, T. C.; Martin, L. R.; Nash, K. L.

2010-03-01

118

Fluctuations and Criticality of a Granular Solid-Liquid-Like Phase Transition  

NASA Astrophysics Data System (ADS)

We present an experimental study of density and order fluctuations in the vicinity of the solid-liquid-like transition that occurs in a vibrated quasi-two-dimensional granular system. The two-dimensional projected static and dynamic correlation functions are studied. We show that density fluctuations, characterized through the structure factor, increase in size and intensity as the transition is approached, but they do not change significantly at the transition itself. The dense, metastable clusters, which present square symmetry, also increase their local order in the vicinity of the transition. This is characterized through the bond-orientational order parameter Q4, which in Fourier space shows an Ornstein-Zernike-like behavior. Depending on the filling density and vertical height, the transition can be of first- or second-order type. In the latter case, the associated correlation length ?4, the relaxation time ?4, the zero k limit of Q4 fluctuations (static susceptibility), the pair correlation function of Q4, and the amplitude of the order parameter obey critical power laws, with saturations due to finite size effects. Their respective critical exponents are ??=1, ??=2, ?=1, ?=0.67, and ?=1/2, whereas the dynamical critical exponent z=??/??=2. These results are consistent with model C of dynamical critical phenomena, valid for a nonconserved critical order parameter (bond-orientation order) coupled to a conserved field (density).

Castillo, Gustavo; Mujica, Nicolás; Soto, Rodrigo

2012-08-01

119

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

120

Coarsening in Solid-Liquid Mixtures-2: A Materials Science Experiment for the ISS  

NASA Technical Reports Server (NTRS)

A materials science experiment has been developed and readied for operation aboard the International Space Station (ISS). Components of this experiment are onboard ISS and area awaiting the flight of science samples. The goal of the experiment is to understand the dynamics of Ostwald ripening, also known as coarsening, a process that occurs in nearly any two-phase mixture found in nature. Attempts to obtain experimental data in ground-based laboratories are hindered due to the presence of gravity, which introduces material transport modes other than that of the coarsening phenomenon. This introduces adjustable parameters in the formulation of theory. The original Coarsening in Solid-Liquid Mixtures (CSLM) mission, which flew on the Space Shuttle in 1997, produced data from a coarsened eutectic alloy. Unfortunately, both the science matrix and the hardware, while nominally functional, did not account adequately for operations in microgravity. A significantly redesigned follow-on experiment, CSLM-2 has been developed to redress the inadequacies of the original experiment. This paper reviews the CSLM-2 project: its history, science goals, flight hardware implementation, and planned operations and analysis

Hickman, J. Mark; Voorhees, Peter W.; Kwon, Yongwoo; Lorik, Tibor

2004-01-01

121

Anisotropy and roughness of the solid-liquid interface of BCC Fe.  

PubMed

Melting point T m and kinetic coefficient ? (a proportional constant between the interfacial velocity ? and undercooling ?T), along with the structural roughness of the solid-liquid interface for body centered cubic (BCC) Fe were calculated by molecular dynamics (MD) simulation. All simulations applied the Sutton-Chen potential, and adopted average bond orientational order (ABOO) parameters together with Voronoi polyhedron method to characterize atomic structure and calculate atomic volume. Anisotropy of T m was found through about 20~40 K decreasing from [100] to [110] and continuously to [111]. Anisotropy of ? with three low index orientations was found as: ? s,[100] >?>?? s,[110]?>?? s,[111] for solidifying process and ? m,[100] >?>?? m,[111]?>?? m,[110] for melting process. Slight asymmetry between melting and solidifying was discovered from that the ratios of ? m/? s are all slightly larger than 1. To explain these, interfacial roughness R int and area ratio S/S 0 (ratio of realistic interfacial area S and the ideal flat cross-sectional area S 0) were defined to verify the anisotropy of interfacial roughness under different supercoolings/superheatings. The results indicated interfacial roughness anisotropies were approximately [100]?>?[111]?>?[110]; the interface in melting process is rougher than that in solidifying process; asymmetry of interfacial roughness was larger when temperature deviation ?T was larger. Anisotropy and asymmetry of interfacial roughness fitted the case of kinetic coefficient ? very well, which could give some explanations to the anisotropies of T m and ?. PMID:25636268

Sun, Yongli; Wu, Yongquan; Lu, Xiuming; Li, Rong; Xiao, Junjiang

2015-02-01

122

Comparative study of turbulent solid-liquid extraction methods for the determination of organochlorine pesticides.  

PubMed

The aim of any extraction method in analytical chemistry is to effectively separate the analytes from the matrix with minimal solvent and time required. In this study, a comparison of the classical Soxhlet extraction and some new turbulent solid-liquid extraction techniques, such as fluidized-bed extraction (FBE), modified dive-in fluidized-bed extraction (dive-in FBE), modified dive-in Soxhlet extraction (dive-in SE) and dive-in thimble extraction (dive-in TE) for the determination of organochlorine pesticides (OCPs) was carried out. The turbulent extraction methods were performed by using the fexIKA vario control series extractor and by modification of the extraction system to dive-in technique, respectively. In addition, FBE and dive-in FBE were operated under the same, only for the FBE system established, optimum conditions. For the determination of the analytes a selective clean-up of the extracts followed by a gas chromatography (GC) method with mass spectrometric detection was used. All advanced extraction methods with reduced time and solvent consumption exhibited higher extraction efficiency than the standard procedure, Soxhlet extraction. PMID:15560930

Bandoniene, Donata; Gfrerer, Marion; Lankmayr, Ernst P

2004-10-29

123

Universality and criticality of a second-order granular solid-liquid-like phase transition  

NASA Astrophysics Data System (ADS)

We experimentally study the critical properties of the nonequilibrium solid-liquid-like transition that takes place in vibrated granular matter. The critical dynamics is characterized by the coupling of the density field with the bond-orientational order parameter Q4, which measures the degree of local crystallization. Two setups are compared, which present the transition at different critical accelerations as a result of modifying the energy dissipation parameters. In both setups five independent critical exponents are measured, associated to different properties of Q4: the correlation length, relaxation time, vanishing wavenumber limit (static susceptibility), the hydrodynamic regime of the pair correlation function, and the amplitude of the order parameter. The respective critical exponents agree in both setups and are given by ??=1 ,??=2 ,? =1 ,? ?0.6 -0.67 , and ? =1 /2 , whereas the dynamical critical exponent is z =??/??=2 . The agreement on five exponents is an exigent test for the universality of the transition. Thus, while dissipation is strictly necessary to form the crystal, the path the system undergoes toward the phase separation is part of a well-defined universality class. In fact, the local order shows critical properties while density does not. Being the later conserved, the appropriate model that couples both is model C in the Hohenberg and Halperin classification. The measured exponents are in accord with the nonequilibrium extension to model C if we assume that ? , the exponent associated in equilibrium to the specific heat divergence but with no counterpart in this nonequilibrium experiment, vanishes.

Castillo, Gustavo; Mujica, Nicolás; Soto, Rodrigo

2015-01-01

124

Molecular Dynamics Study of Freezing Point and Solid-Liquid Interfacial Free Energy of Stockmayer Fluids  

SciTech Connect

Freezing temperatures of Stockmayer fluids with different dipolar strength at zero pressure are estimated and computed using three independent molecular-dynamics (MD) simulation methods, namely, the superheating-undercooling method, the constant-pressure and constant-temperature (NPT) two phase coexistence method, and the constant-pressure and constant-enthalpy (NPH) coexistence method. The best estimate of the freezing temperature (in reduced unit) for the Stockmayer (SM) fluid with a reduced dipole moment is 0.656 0.001, 0.726 0.002 and 0.835 0.005, respectively. The freezing temperature increases with the dipolar strength. The solid-liquid interfacial free energies of the (111), (110) and (100) interface are calculated for the first time using two independent methods, namely, the cleaving-wall method and the interfacial fluctuation method. Both methods predict that the interfacial free energy increases with the dipole moment. Although the interfacial fluctuation method suggests a weaker interfacial anisotropy, particularly for strongly dipolar SM fluids, both methods predicted the same trend of interfacial anisotropy, that is, .

Wang, J. [University of Nebraska, Lincoln; Apte, Pankaj [Indian Institute of Technology, Kanpur; Morris, James R [ORNL; Zeng, X.C. [University of Nebraska, Lincoln

2013-01-01

125

Metastable nanobubbles at the solid-liquid interface due to contact angle hysteresis.  

PubMed

Nanobubbles exist at solid-liquid interfaces between pure water and hydrophobic surfaces with very high stability, lasting in certain cases up to several days. Not only semispherical but also other shapes, such as micropancakes, are known to exist at such interfaces. However, doubt has been raised as to whether or not the nanobubbles are gas-phase entities. In this study, surface nanobubbles at a pure water-highly ordered pyrolytic graphite (HOPG) interface were investigated by peak force quantitative nanomechanics (PF-QNM). Multiple isolated nanobubbles generated by the solvent-exchange method were present on the terraced areas, avoiding the steps of the HOPG surface. Adjacent nanobubbles coalesced and formed metastable nanobubbles. Coalescence was enhanced by the PF-QNM measurement. We determined that nanobubbles can exist for a long time because of nanoscale contact angle hysteresis at the water-HOPG interface. Moreover, the hydrophilic steps of HOPG were avoided during coalescence, providing evidence that the nanobubbles are truly gas phase. PMID:25540821

Nishiyama, Takashi; Yamada, Yutaka; Ikuta, Tatsuya; Takahashi, Koji; Takata, Yasuyuki

2015-01-27

126

Influence of solid-liquid interactions on dynamic wetting: a molecular dynamics study.  

PubMed

Large-scale molecular dynamics (MD) simulations of liquid drops spreading on a solid substrate have been carried out for a very wide range of solid-liquid interactions and equilibrium contact angles. The results for these systems are shown to be consistent with the molecular-kinetic theory (MKT) of dynamic wetting, which emphasizes the role of contact-line friction as the principal channel of energy dissipation. Several predictions have been confirmed. These include a quantitative link between the dynamics of wetting and the work of adhesion and the existence of an optimum equilibrium contact angle that maximizes the speed of wetting. A feature of the new work is that key parameters (?(0) and ?), normally accessible only by fitting the MKT to dynamic contact angle data, are also obtained directly from the simulations, with good agreement between the two sources. This validates the MKT at some fundamental level. Further verification is provided by contact angle relaxation studies, which also lend support to the interfacial tension relaxation process invoked in Shikhmurzaev's hydrodynamic model of dynamic wetting. PMID:21715888

Bertrand, Emilie; Blake, Terence D; Coninck, Joël De

2009-11-18

127

Biodegradation of Endocrine Disruptors in Solid-Liquid Two-Phase Partitioning Systems by Enrichment Cultures  

PubMed Central

Naturally occurring and synthetic estrogens and other molecules from industrial sources strongly contribute to the endocrine disruption of urban wastewater. Because of the presence of these molecules in low but effective concentrations in wastewaters, these endocrine disruptors (EDs) are only partially removed after most wastewater treatments, reflecting the presence of these molecules in rivers in urban areas. The development of a two-phase partitioning bioreactor (TPPB) might be an effective strategy for the removal of EDs from wastewater plant effluents. Here, we describe the establishment of three ED-degrading microbial enrichment cultures adapted to a solid-liquid two-phase partitioning system using Hytrel as the immiscible water phase and loaded with estrone, estradiol, estriol, ethynylestradiol, nonylphenol, and bisphenol A. All molecules except ethynylestradiol were degraded in the enrichment cultures. The bacterial composition of the three enrichment cultures was determined using 16S rRNA gene sequencing and showed sequences affiliated with bacteria associated with the degradation of these compounds, such as Sphingomonadales. One Rhodococcus isolate capable of degrading estrone, estradiol, and estriol was isolated from one enrichment culture. These results highlight the great potential for the development of TPPB for the degradation of highly diluted EDs in water effluents. PMID:23728808

dos Santos, Silvia Cristina Cunha; Ouellette, Julianne; Juteau, Pierre; Lépine, François; Déziel, Eric

2013-01-01

128

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

129

Molecular order and thermodynamics of the solid-liquid transition in triglycerides via Raman spectroscopy.  

PubMed

The conformational and thermodynamic behavior of five monoacid saturated triglycerides (TGs) before, during, and above the beta polymorph --> liquid phase transition was studied using Raman spectroscopy. The Raman ratio I[upsilon(s)(CH(2))]/I[upsilon(as)(CH(2))], used to identify intramolecular order about TG hydrocarbon chains, demonstrated that a single conformation, geometry and symmetry existed in liquid-state TGs. The Raman ratio I(1080)/I(1130), used to determine the intermolecular order/disorder about the hydrocarbon chains and relative trans/gauche content, remained constant for TGs in the crystalline state, but steadily increased as a function of temperature in the liquid state. Use of the van't Hoff relation and the spectroscopically-determined trans/gauche content indicated the presence of distinctive pre- and post-transition enthalpies/entropies indicating that the beta --> liquid phase transition is "soft", with possible intermediate conformations. The liquid-state ester carbonyl stretching region, which gave rise to a broad peak between 1780-1700 cm(-1), was decomposed into multiple components. It demonstrated solid-like character 2-3 degrees C above the TG beta-polymorph melting point, above which no further change in spectral character was observed. These results indicate that the solid-liquid transition in TGs is of the "soft" type with non-lamellar conformations likely present in the melt. PMID:18665310

Da Silva, Eric; Rousseau, Dérick

2008-08-21

130

Improved subgrid scale model for dense turbulent solid-liquid two-phase flows  

NASA Astrophysics Data System (ADS)

The dense solid-phase governing equations for two-phase flows are obtained by using the kinetic theory of gas molecules. Assuming that the solid-phase velocity distributions obey the Maxwell equations, the collision term for particles under dense two-phase flow conditions is also derived. In comparison with the governing equations of a dilute two-phase flow, the solid-particle's governing equations are developed for a dense turbulent solid-liquid flow by adopting some relevant terms from the dilute two-phase governing equations. Based on Cauchy-Helmholtz theorem and Smagorinsky model, a second-order dynamic sub-grid-scale (SGS) model, in which the sub-grid-scale stress is a function of both the strain-rate tensor and the rotation-rate tensor, is proposed to model the two-phase governing equations by applying dimension analyses. Applying the SIMPLEC algorithm and staggering grid system to the two-phase discretized governing equations and employing the slip boundary conditions on the walls, the velocity and pressure fields, and the volumetric concentration are calculated. The simulation results are in a fairly good agreement with experimental data in two operating cases in a conduit with a rectangular cross-section and these comparisons imply that these models are practical.

Xuelin, Tang; Zhongdong, Qian; Yulin, Wu

2004-08-01

131

Solid/liquid phase diagram of the ammonium sulfate/glutaric acid/water system.  

PubMed

We have studied the low temperature phase diagram and water activities of the ammonium sulfate/glutaric acid/water system using differential scanning calorimetry, infrared spectroscopy of thin films, and a new technique: differential scanning calorimetry-video microscopy. Using these techniques, we have determined that there is a temperature-dependent kinetic effect to the dissolution of glutaric acid in aqueous solution. We have mapped the solid/liquid ternary phase diagram, determined the water activities based on the freezing point depression, and determined the ice/glutaric acid phase boundary as well as the ternary eutectic composition and temperature. We have also modified our glutaric acid/water binary phase diagram previously published based on these new results. We compare our results for the ternary system to the predictions of the Extended AIM Aerosol Thermodynamics Model (E-AIM), and find good agreement for the ice melting points in the ice primary phase field of this system; however, significant differences were found with respect to phase boundaries, concentration and temperature of the ternary eutectic, and glutaric acid dissolution. PMID:23544733

Beyer, Keith D; Pearson, Christian S; Henningfield, Drew S

2013-05-01

132

Kinetics of the exchanges at the solid liquid interface during the dissolution process of gallium orthophosphate  

NASA Astrophysics Data System (ADS)

Gallium orthophosphate is a piezoelectric material with an ?-quartz structure. In order to manufacture bulk acoustic wave devices (BAW), controlled chemical dissolution is often used to reduce the thickness of the piezoelectric membranes. This paper presents the kinetics of the chemical exchanges, which occur at the solid-liquid interface during the chemical dissolution of GaPO 4 in phosphoric acid. Based on chemical composition of phosphoric acid solvent, the pure dissolution rate is determined. A strong anisotropy of chemical reactivity is formed. The dissolution rate is the lowest for the crystallographic z-plane (0 0 0 1) but this orientation is the most sensitive with respect to the proton concentration and the temperature. In accordance with the crystal growth rates, the nucleation at the interface for the (1 0 2 0) plane, named X-plane, is also the most rapidly dissolved. Assuming the activation energies corresponding to dissolution and to nucleation are like standard activation energies, the different values of the standard enthalpy variation are calculated. The most important variation is obtained for the z-plane (? rH =-14.3 kJ/mol) and the lowest for the X-plane (? rH =-5.4 kJ/mol).

Prud'homme, N.; Cachau-Herreillat, D.; Papet, P.; Cambon, O.

2006-01-01

133

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

134

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

135

Modelling of the pre-arcing period in HBC fuses including solid - liquid - vapour phase changes of the fuse element  

Microsoft Academic Search

In this paper, we present a model and a numerical method of the fuse element heating including solid-liquid-vapour phase transitions in order to evaluate the pre-arcing time in HBC fuses. The mathematical model is based on the enthalpy formulation of the heat equation with a source term representing the Joule effect coupled with the Laplace equation for the potential and

D. Rochette; W. Bussiere; R. Touzani; S. Memiaghe; G. Velleaud; P. Andre

2007-01-01

136

Detecting filter-cake pathologies in solid–liquid filtration: semi-tech scale demonstrations using electrical resistance tomography (ERT)  

Microsoft Academic Search

Solid–liquid filtration monitoring by means of a single inexpensive 16-element ring sensor array for electrical resistance tomography (ERT) is described. The high sensitivity of the UMIST Mark 1b-E data acquisition system led to the unexpected finding that this tomography array can detect movement of the liquid level during filtration. This degree of sensitivity was also capable of detecting any tilt

D. Vlaev; M. Wang; T. Dyakowski; R. Mann; B. D. Grieve

2000-01-01

137

Preparation, structure and crystallinity of chitosan nano-fibers by a solid–liquid phase separation technique  

Microsoft Academic Search

Chitosan acetate nano-fibers were fabricated via a solid–liquid 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 50–500nm 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 ?18°C and ?80°C

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

2011-01-01

138

Aide aux doctorants pour la participation des Aide aux doctorants pour la participation des colloques  

E-print Network

Aide aux doctorants pour la participation à des colloques Aide aux doctorants pour la participation à des colloques retour Formation doctorale Aide aux doctorants pour la participation à des colloques aide vient compléter les financements déjà prévus par les laboratoires et les �coles doctorales pour

Di Girolami, Cristina

139

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

140

A comparison of BNR activated sludge systems with membrane and settling tank solid-liquid separation.  

PubMed

Installing membranes for solid-liquid separation into biological nutrient removal (BNR) activated sludge (AS) systems makes a profound difference not only to the design of the membrane bio-reactor (MBR) BNR system itself, but also to the design approach for the whole wastewater treatment plant (WWTP). In multi-zone BNR systems with membranes in the aerobic reactor and fixed volumes for the anaerobic, anoxic and aerobic zones (i.e. fixed volume fractions), the mass fractions can be controlled (within a range) with the inter-reactor recycle ratios. This zone mass fraction flexibility is a significant advantage of MBR BNR systems over BNR systems with secondary settling tanks (SSTs), because it allows changing the mass fractions to optimise biological N and P removal in conformity with influent wastewater characteristics and the effluent N and P concentrations required. For PWWF/ADWF ratios (fq) in the upper range (fq approximately 2.0), aerobic mass fractions in the lower range (f(maer) < 0.60) and high (usually raw) wastewater strengths, the indicated mode of operation of MBR BNR systems is as extended aeration WWTPs (no primary settling and long sludge age). However, the volume reduction compared with equivalent BNR systems with SSTs will not be large (40-60%), but the cost of the membranes can be offset against sludge thickening and stabilisation costs. Moving from a flow unbalanced raw wastewater system to a flow balanced (fq = 1) low (usually settled) wastewater strength system can double the ADWF capacity of the biological reactor, but the design approach of the WWTP changes away from extended aeration to include primary sludge stabilisation. The cost of primary sludge treatment then has to be offset against the savings of the increased WWTP capacity. PMID:16889266

Ramphao, M C; Wentzel, M C; Ekama, G A; Alexander, W V

2006-01-01

141

Impact of membrane solid-liquid separation on design of biological nutrient removal activated sludge systems.  

PubMed

Installing membranes for solid-liquid separation into biological nutrient removal (BNR) activated sludge (AS) systems makes a profound difference not only in the design of the BNR system itself, but also in the design approach for the whole wastewater treatment plant (WWTP). In multizone BNR systems with membranes in the aerobic reactor and fixed volumes for the anaerobic, anoxic, and aerobic zones (i.e., fixed volume fractions), the mass fractions can be controlled (within a range) with the interreactor recycle ratios. This zone mass fraction flexibility is a significant advantage in membrane BNR systems over conventional BNR systems with SSTs, because it allows for changing of the mass fractions to optimize biological N and P removal in conformity with influent wastewater characteristics and the effluent N and P concentrations required. For PWWF/ADWF ratios in the upper range (f(q) approximately 2.0), aerobic mass fractions in the lower range (f(maer) < 0.60), and high (usually raw) wastewater strengths, the indicated mode of operation of MBR BNR systems is as extended aeration WWTPs. Although the volume reduction compared with equivalent conventional BNR systems with secondary settling tanks is not as large (40% to 60%), the cost of the membranes can be offset against sludge thickening and stabilization costs. Moving from a flow-unbalanced raw wastewater system to a flow-balanced (f(q) = 1), low (usually settled) wastewater strength system can double the ADWF capacity of the biological reactor, but the design approach of the WWTP changes from extended aeration to include primary sludge stabilization. The cost of primary sludge treatment then has to be paid from the savings from the increased WWTP capacity. PMID:15696540

Ramphao, M; Wentzel, M C; Merritt, R; Ekama, G A; Young, T; Buckley, C A

2005-03-20

142

Nanobubbles do not sit alone at the solid-liquid interface.  

PubMed

The unexpected stability and anomalous contact angle of gaseous nanobubbles at the hydrophobic solid-liquid interface has been an issue of debate for almost two decades. In this work silicon-nitride tipped AFM cantilevers are used to probe the highly ordered pyrolytic graphite (HOPG)-water interface with and without solvent-exchange (a common nanobubble production method). Without solvent-exchange the force obtained by the single force and force mapping techniques is consistent over the HOPG atomic layers and described by DLVO theory (strong EDL repulsion). With solvent-exchange the force is non-DLVO (no EDL repulsion) and the range of the attractive jump-in (>10 nm) over the surface is grouped into circular areas of longer range, consistent with nanobubbles, and the area of shorter range. The non-DLVO nature of the area between nanobubbles suggests that the interaction is no longer between a silicon-nitride tip and HOPG. Interfacial gas enrichment (IGE) covering the entire area between nanobubbles is suggested to be responsible for the non-DLVO forces. The absence of EDL repulsion suggests that both IGE and nanobubbles are not charged. The coexistence of nanobubbles and IGE provides further evidence of nanobubble stability by dynamic equilibrium. The IGE cannot be removed by contact mode scanning of a cantilever tip in pure water, but in a surfactant (SDS) solution the mechanical action of the tip and the chemical action of the surfactant molecules can successfully remove the enrichment. Strong EDL repulsion between the tip and nanobubbles/IGE in surfactant solutions is due to the polar heads of the adsorbed surfactant molecules. PMID:23597206

Peng, Hong; Hampton, Marc A; Nguyen, Anh V

2013-05-21

143

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

144

Studies Of The Solid-Liquid Interface Via Laser Excited Surface Plasmon Spectroscopy  

NASA Astrophysics Data System (ADS)

The chemistry of the solid-liquid interface is of intense practical and theoretical interest, since a vast majority of heterogeneous reaction, adsorption, and epitaxy processes occur there. It is also among the most difficult of systems to study. One must have a probe which is extraordinarily sensitive, in order to observe the first few atomic layers, and very selective, in order to separate the effects of the surface associated species from those of the solvent or neat liquid in close proximity. To fulfill these requirements and to retain the advantages of optical spectroscopic techniques requires that the electric fields employed for excitation of interfacial molecules be spatially localized. When the solid component of the interface is one of the non-lossy metals, the above constraints can be satisfied by exciting a surface plasma resonance of a thin metallic film. Both theoretical and experimental work has shown that enhancement of Raman signals at Ag-liquid interfaces can be as high as 4 x 104. In addition the excitation of surface plasma resonances at metallic interfaces in the Kretschmann configuration has been shown to be extremely sensitive to adsorption of components from the ambient.4-7 In general the position of the plasmon resonance along the wavevector axis shifts and broadens upon adsorption or overcoating. Thus the exci-tation of surface plasma resonances at metal-liquid interfaces offers the possibility of simultaneously studying both adsorption-desorption kinetics, via observation of the reflectivity, and interfacial geometries, via enhanced signal vibrational spectroscopy of the adsorbates themselves.

Bohn, P. W.

1986-06-01

145

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

146

Solid-liquid separation by sonochemistry: a new approach for the separation of mineral suspensions.  

PubMed

The effect of sonochemistry to acidify solutions was applied for the solid-liquid separation of three kinds of mineral suspensions. At first, the relationship was measured between zeta-potential and pH in these suspensions to find pH levels correspondent to the isoelectric points. Then sonication (200 kHz or 28 kHz) was applied to adjust pH to the isoelectric points and separated particles from solutions by still-standing and spontaneous precipitation. Compared to the conventional methods using filters and chemical agents, the advantage of this sonochemical separation is two-fold. First, it does not require the maintenance of filters. Second, separated particles are easy to use since they are not mixed with pH adjusters and chemical flocculants. Isoelectric zone (ion strength 0.01, concentration 0.001 wt.%) of green tuff, andesite and titanium dioxide suspensions tested in this study were pH 1.1-3.7, 0.8-3.4, 2.7-5.7, respectively. The sonication of green tuff and andesite suspensions at 200 kHz changed the pH to the isoelectric zone despite the pH buffering effect of eluted alkali earth metals, and successfully precipitated the particles. On the contrary, the sonication of these suspensions at 28 kHz failed to adjust pH to the isoelectric zone, and the particles did not precipitate. In addition, the degradation of particles was observed in the SEM photographs of particles sonicated at 28 kHz, whereas no significant change was detected in particles sonicated at 200 kHz. Thus, it is concluded that the optimal frequency is about 200 kHz because its strong chemical effect can easily adjust the pH while its relatively weak physical effect prevents the degradation of particles. PMID:20643570

Nakamura, Takashi; Okawa, Hirokazu; Kawamura, Youhei; Sugawara, Katsuyasu

2011-01-01

147

Real Time Characterization of Solid/Liquid Interfaces During Directional Solidification  

NASA Technical Reports Server (NTRS)

A X-Ray Transmission Microscope (XTM) has been developed to observe in real time and in-situ solidification phenomenon at the solid/liquid interface. Recent improvements in the horizontal Bridgman furnace design provides real-time magnification (during solidification) up to 12OX. The increased magnification has enabled for the first time the XTM imaging of real-time growth of fibers and particles with diameters of 3-6 micrometers. Further, morphological transitions from planar to cellular interfaces have also been imaged. Results from recent XTM studies on Al-Bi monotectic system, Al-Au eutectic system and interaction of insoluble particles with s/I interfaces in composite materials will be presented. An important parameter during directional solidification of molten metal is the interfacial undercooling. This parameter controls the morphology and composition at the s/I interface. Conventional probes such as thermocouples, due to their large bead size, do not have sufficient resolution for measuring undercooling at the s/I interface. Further, the intrusive nature of the thermocouples also distorts the thermal field at the s/I interface. To overcome these inherent problems we have recently developed a compact furnace which utilizes a non-intrusive technique (Seebeck) to measure undercooling at the S/I interface. Recent interfacial undercooling measurements obtained for the Pb-Sn system will be presented. The Seebeck measurement furnace in the future will be integrated with the XTM to provide the most comprehensive tool for real time characterization of s/I interfaces during solidification.

Sen, S.; Kaukler, W. K.; Curreri, P. A.; Peters, P.

1997-01-01

148

Article original Rsistance aux antiseptiques et antibiotiques  

E-print Network

'espèce Staphylococcus epidermidis comme réservoirs possibles de plasmides de résistance aux antibiotiques mais aussi aux are resistant to many antibiotics and especially the Enterococcus and the species Staphylococcus epidermidis for the bacterial species studied (Staphylococcus, Streptococcus and Bacillus), the scattering of the minimum

Paris-Sud XI, Université de

149

An Estimate for the Deviation from the Mirros Image Due to Solid Liquid Phase Transition of Metals at Shock Unloading.  

NASA Astrophysics Data System (ADS)

We extend the underlying physical reasoning of Walsh and Christian (1955) in a manner which allows a reasonable estimation for the excepted deviation from the mirror image approximation due to solid liquid phase transition. This estimated is limited to a phase transition that occurs at the unloading phase in metals such as Tin and Lead. The idea underlying this estimate is the accumulation of various contributions to the entropy and an estimation of the expected expansion at atmospheric pressure. These estimates combined with the Lindmann melting law and the Clausius Clyperon equation are used to estimate the expansion at the phase transition and the resulting change in free surface velocity.

Pistinner, Shlomi; Peker, Sharon; Werdiger, Meir; Eliezer, Shalom

2007-06-01

150

1-(2-pyridylazo)-2-naphthol (PAN) as extractant in solid-liquid extraction of some trivalent rare earth elements.  

PubMed

In the present paper, solid-liquid extraction behaviour of RE(III) (RE La, Ce, Pr, Nd, Sm, Gd, Dy and Yb) by the use of 1-(2-pyridylazo)-2-naphthol (PAN, HL) as an extractant in paraffin (m.p. 48 approximately 50 degrees) has been investigated at 80 +/- 0.07 degrees. The effect of equilibrium time, pH of aqueous phase, concentration of extractant in paraffin and solid diluent as well as buffer solution used on the extraction efficiency of RE(III) have been discussed. The extraction reaction is RE(3+) + 2HL(o) + Cl(-) <==> REL(2)Cl(o) + 2H(+). PMID:18965615

Gao, J; Hu, G; Kang, J; Bai, G

1993-02-01

151

A solid-liquid diffusion model for growth and dissolution of ternary alloys by liquid phase epitaxy  

NASA Astrophysics Data System (ADS)

This paper presents a solid-liquid diffusion model for ternary alloys formed by liquid phase epitaxy (LPE). A fully numerical procedure is developed to simulate the growth and dissolution processes. The simulation results for the Al?Ga?As system show that the growth rate and the solid composition are functions of the growth temperature and the cooling rate. The computed solid composition and growth thickness are compared with available experimental data. The numerical and experimental results are in good agreement. The computational model developed in this study is suitable for simulations of solution growth of ternary alloys.

Kimura, M.; Qin, Z.; Dost, S.

1996-01-01

152

A computational model for the analysis of diffusive binary alloy solid/liquid phase change energy transport  

NASA Technical Reports Server (NTRS)

A model is presented for the prediction of solid/liquid, binary alloy, phase change energy transport. The model incorporates only one-dimensional, diffusive transport of both energy and species but is not inherently limited in any way to such a restriction. The model incorporates a previously developed algorithm for single constituent phase change energy transport and is applied to the energy transport as well as the species transport aspects of the problem. The model is applied to four example cooling problems and is shown to perform exceedingly well from an algorithmic point of view.

Schneider, G. E.

1991-01-01

153

S-wave velocity as an indicator of solid-liquid transition in clay  

NASA Astrophysics Data System (ADS)

Clayey landslides, which are widely spread all over the world, pose specific problems to territorial planners, owing to dramatic variations in kinematics. Indeed, the analysis of landslide movements in a clay-rich area like the Trièves plateau (French Western Alps) indicates that slow slope movements can suddenly accelerate or fluidize as a result of heavy and/or long-lasting rainfalls or loading. Previous rheometric tests performed on the Trièves clay revealed a thixotropic behavior of the clay with a highly pronounced viscosity bifurcation at a yield stress ?c. Below that stress, the material behaves like a solid, while it abruptly starts flowing when this yield stress is reached. This solid-liquid transition was investigated by measuring the variations of the shear wave velocity (Vs) in the Trièves clay during rheometric tests and flume tests. First, rheometric parallel-plate tests were performed at 3 different clay water contents (52%, 66% and 78%). Oscillatory stress tests were conducted during the experiments, allowing the shear modulus and Vs to be measured as a function of the shear stress level. Results revealed a dramatic Vs change at the same yield stress as for the viscosity bifurcation. When the stress is lower than the yield stress, Vs regularly increases with time up to a limit value. As soon as the yield stress is reached, Vs abruptly decreases to reach values of a few m/s in the fluidized clay. In order to investigate at a larger scale (approximately 1 m) the evolution of the shear wave velocity during the clay fluidization, flume tests were performed for two clay water contents (57 % and 68%). These experiments consist in progressively tilting a flume filled with a saturated clay layer (35cm wide, 60cm long and 10cm deep) until reaching the fluidization at a given slope. The Rayleigh wave velocity (VR), which is related to Vs, was continuously monitored using a piezometric source and 4 vertical component accelerometers placed at the surface of the clay layer. The Rayleigh wave propagation was reconstructed by cross correlating the source signal (50-700 Hz sweep) and the 4 recorded signals. The clay mass motion was measured, using 3 height sensors (vertical displacement) and a digital camera to follow the displacement of three superficial markers (colored pins). The tilt angle, which increased by 1 degree per minute, was given by an inclinometer placed on the flume. Signals were generated every 30 seconds. Results showed no variation of VR during the flume tilting. Just before that the mass moved at a critical angle, a rapid decrease in VR (between 4 and 7%) was observed on all the signals, evidencing a change in Vs at the base of the layer. Both experiments showed that Vs could be a valuable good indicator for rheological changes in clay. The seismic measurements during flume tests are in agreement with passive seismic monitoring results at the Pont Bourquin landslide (Switzerland), where a drop of 7% in VR was measured 4 days before a earth-slide earth-flow in 2010, which mobilized about 4,500 m3 of clay material.

Mainsant, Guénolé; Jongmans, Denis; Chambon, Guillaume; Larose, Eric; Baillet, Laurent

2013-04-01

154

Transformation of ferulic acid to vanillin using a fed-batch solid-liquid two-phase partitioning bioreactor.  

PubMed

Amycolatopsis sp. ATCC 39116 (formerly Streptomyces setonii) has shown promising results in converting ferulic acid (trans-4-hydroxy-3-methoxycinnamic acid; substrate), which can be derived from natural plant wastes, to vanillin (4-hydroxy-3-methoxybenzaldehyde). After exploring the influence of adding vanillin at different times during the growth cycle on cell growth and transformation performance of this strain and demonstrating the inhibitory effect of vanillin, a solid-liquid two-phase partitioning bioreactor (TPPB) system was used as an in situ product removal technique to enhance transformation productivity by this strain. The thermoplastic polymer Hytrel(®) G4078W was found to have superior partitioning capacity for vanillin with a partition coefficient of 12 and a low affinity for the substrate. A 3-L working volume solid-liquid fed-batch TPPB mode, using 300 g Hytrel G4078W as the sequestering phase, produced a final vanillin concentration of 19.5 g/L. The overall productivity of this reactor system was 450 mg/L. h, among the highest reported in literature. Vanillin was easily and quantitatively recovered from the polymers mostly by single stage extraction into methanol or other organic solvents used in food industry, simultaneously regenerating polymer beads for reuse. A polymer-liquid two phase bioreactor was again confirmed to easily outperform single phase systems that feature inhibitory or easily further degraded substrates/products. This enhancement strategy might reasonably be expected in the production of other flavor and fragrance compounds obtained by biotransformations. PMID:24167066

Ma, Xiao-kui; Daugulis, Andrew J

2014-01-01

155

In Situ Monitoring of Solid-Liquid Interface of Aluminum Alloy Using High-Temperature Ultrasonic Sensor  

NASA Astrophysics Data System (ADS)

A high temperature ultrasonic sensor with a titanium buffer rod has been applied to the in situ monitoring of the solid-liquid interface of an aluminum alloy (Al-12.6%Si) during unidirectional solidification at 700°C. The ultrasonic sensor consists of a conventional piezoelectric transducer, a titanium buffer rod as an acoustic waveguide and a cooling system. Its length is approximately 300 mm. This ultrasonic sensor, because of the unique characteristics of titanium, provides not only good acoustic coupling to molten aluminum but also high-corrosion resistance. Pulse echo measurements in the molten aluminum alloy are performed using the sensor at 2.25 MHz. A clear reflected echo from a stable solid-liquid interface of the aluminum alloy has been successfully monitored. In addition, the reflected echo from the growing interface during unidirectional solidification has also been monitored. The growth rate of the interface was determined to be 0.12 mm/s from the monitored echo.

Ihara, Ikuo; Burhan, Dikky; Seda, Yoshihisa

2005-06-01

156

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

157

Experimental study of the solid-liquid interface in a yield-stress fluid flow upstream of a step  

NASA Astrophysics Data System (ADS)

We present an experimental study investigating the transition zone between a liquid-like unyielded region and a solid-like yielded region in a yield-stress fluid. The configuration consists of a rectangular closed-channel flow disturbed by the presence of a step. Upstream of the step, a solid-liquid interface between a dead zone and a flow zone appears. In this study, we use a model fluid, namely polymer micro-gel Carbopol, which exhibits Herschel-Bulkley viscoplastic rheology. Exploiting the fluid transparency, the flow is monitored by particle image velocimetry using an internal visualization technique. The main outcome of this study is to show that, except in a thin transition layer close to the solid-liquid interface, the flow behaves as an apparent Poiseuille flow with an apparent slip condition at the base. The slip frontier is found to be almost independent of the flow rate while the corresponding slip velocity increases with the flow rate.

Luu, Li-Hua; Philippe, Pierre; Chambon, Guillaume

2015-01-01

158

Experimental study of the solid-liquid interface in a yield-stress fluid flow upstream of a step.  

PubMed

We present an experimental study investigating the transition zone between a liquid-like unyielded region and a solid-like yielded region in a yield-stress fluid. The configuration consists of a rectangular closed-channel flow disturbed by the presence of a step. Upstream of the step, a solid-liquid interface between a dead zone and a flow zone appears. In this study, we use a model fluid, namely polymer micro-gel Carbopol, which exhibits Herschel-Bulkley viscoplastic rheology. Exploiting the fluid transparency, the flow is monitored by particle image velocimetry using an internal visualization technique. The main outcome of this study is to show that, except in a thin transition layer close to the solid-liquid interface, the flow behaves as an apparent Poiseuille flow with an apparent slip condition at the base. The slip frontier is found to be almost independent of the flow rate while the corresponding slip velocity increases with the flow rate. PMID:25679714

Luu, Li-Hua; Philippe, Pierre; Chambon, Guillaume

2015-01-01

159

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

E-print Network

cat litter down the toilets. Housing staff reserves the right to conduct periodic animal welfarei:\\staff\\auxs\\auxs_uho\\common\\forms_current\\correspondence\\pet agreement.doc University Housing Cat arriving on-campus. B. Service animals must be pre-approved by the Disability Resource Center. C. Cats

Bertini, Robert L.

160

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

161

Direct insight into the three-dimensional internal morphology of solid-liquid-vapor interfaces at microscale.  

PubMed

Solid-liquid-vapor interfaces dominated by the three-phase contact line, usually performing as the active center in reactions, are important in biological and industrial processes. In this contribution, we provide direct three-dimensional (3D) experimental evidence for the inside morphology of interfaces with either Cassie or Wenzel states at micron level using X-ray micro-computed tomography, which allows us to accurately "see inside" the morphological structures and quantitatively visualize their internal 3D fine structures and phases in intact samples. Furthermore, the in-depth measurements revealed that the liquid randomly and partly located on the top of protrusions on the natural and artificial superhydrophobic surfaces in Cassie regime, resulting from thermodynamically optimal minimization of the surface energy. These new findings are useful for the optimization of classical wetting theories and models, which should promote the surface scientific and technological developments. PMID:25683025

Yang, Shuai; Du, Jiexing; Cao, Moyuan; Yao, Xi; Ju, Jie; Jin, Xu; Su, Bin; Liu, Kesong; Jiang, Lei

2015-04-13

162

New best estimates for radionuclide solid-liquid distribution coefficients in soils. Part 2: naturally occurring radionuclides.  

PubMed

Predicting the transfer of radionuclides in the environment for normal release, accidental, disposal or remediation scenarios in order to assess exposure requires the availability of an important number of generic parameter values. One of the key parameters in environmental assessment is the solid liquid distribution coefficient, K(d), which is used to predict radionuclide-soil interaction and subsequent radionuclide transport in the soil column. This article presents a review of K(d) values for uranium, radium, lead, polonium and thorium based on an extensive literature survey, including recent publications. The K(d) estimates were presented per soil groups defined by their texture and organic matter content (Sand, Loam, Clay and Organic), although the texture class seemed not to significantly affect K(d). Where relevant, other K(d) classification systems are proposed and correlations with soil parameters are highlighted. The K(d) values obtained in this compilation are compared with earlier review data. PMID:19375832

Vandenhove, H; Gil-García, C; Rigol, A; Vidal, M

2009-09-01

163

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; Nordén, Sara; Grolander, Sara; Sheppard, Steve

2013-05-01

164

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

165

Detection of different oxidation states of individual manganese porphyrins during their reaction with oxygen at a solid/liquid interface  

NASA Astrophysics Data System (ADS)

Manganese porphyrins have been extensively investigated as model systems for the natural enzyme cytochrome P450 and as synthetic oxidation catalysts. Here, we report single-molecule studies of the multistep reaction of manganese porphyrins with molecular oxygen at a solid/liquid interface, using a scanning tunnelling microscope (STM) under environmental control. The high lateral resolution of the STM, in combination with its sensitivity to subtle differences in the electronic properties of molecules, allowed the detection of at least four distinct reaction species. Real-space and real-time imaging of reaction dynamics enabled the observation of active sites, immobile on the experimental timescale. Conversions between the different species could be tuned by the composition of the atmosphere (argon, air or oxygen) and the surface bias voltage. By means of extensive comparison of the results to those obtained by analogous solution-based chemistry, we assigned the observed species to the starting compound, reaction intermediates and products.

den Boer, Duncan; Li, Min; Habets, Thomas; Iavicoli, Patrizia; Rowan, Alan E.; Nolte, Roeland J. M.; Speller, Sylvia; Amabilino, David B.; de Feyter, Steven; Elemans, Johannes A. A. W.

2013-07-01

166

A Dynamic Model for the Interaction Between an Insoluble Particle and an Advancing Solid/Liquid Interface  

NASA Technical Reports Server (NTRS)

Most models that describe the interaction of an insoluble particle with an advancing solid-liquid interface are based on the assumption of steady state. However, as demonstrated by experimental work, the process does not reach steady state until the particle is pushed for a while by the interface. In this work, a dynamic mathematical model was developed. The dynamic model demonstrates that this interaction is essentially non-steady state and that steady state eventually occurs only when solidification is conducted at sub-critical velocities. The model was tested for three systems: aluminum-zirconia particles, succinonitrilepolystyrene particles, and biphenyl-glass particles. The calculated values for critical velocity of the pushing/engulfment transition were in same range with the experimental ones.

Catalina, A. V.; Mukherjee, S.; Stefanescu, D. M.

2000-01-01

167

Rapid Carbonation for Calcite from a Solid-Liquid-Gas System with an Imidazolium-Based Ionic Liquid  

PubMed Central

Aqueous carbonation of Ca(OH)2 is a complex process that produces calcite with scalenohedral calcite phases and characterized by inadequate carbonate species for effective carbonation due to the poor dissolution of CO2 in water. Consequently, we report a solid-liquid-gas carbonation system with an ionic liquid (IL), 1-butyl-3-methylimidazolium bromide, in view of enhancing the reaction of CO2 with Ca(OH)2. The use of the IL increased the solubility of CO2 in the aqueous environment and enhanced the transport of the reactive species (Ca2+ and CO32?) and products. The presence of the IL also avoided the formation of the CaCO3 protective and passivation layer and ensured high carbonation yields, as well as the production of stoichiometric rhombohedral calcite phases in a short time. PMID:24968273

Ibrahim, Abdul-Rauf; Vuningoma, Jean Bosco; Huang, Yan; Wang, Hongtao; Li, Jun

2014-01-01

168

Use of complementary neutron techniques in studying the effect of a solid/liquid interface on bulk solution structures  

SciTech Connect

By appropriate combination of neutron scattering techniques, it is possible to obtain structural information at various distances from a solid/liquid interface and thus probe in some detail how the surface structures evolve into bulk structures. We have used neutron reflectometry (NR) with a newly developed shear cell, near surface small angle neutron scattering (NSSANS) again in combination with the new shear cell, and regular small angle neutron scattering (SANS) with a standard Couette shear cell to probe the structures formed in our aqueous surfactant systems and how they react to a flow field, particularly in the near surface region of a solid/liquid interface. We present data for a 20mM aqueous solutions of 70% cetyltrimethylammonium 3,5-dichlorobenzoate (abbreviated CTA3,5ClBz) and 30% CTAB. This system forms a very viscoelastic solution containing long threadlike micelles. NR only probes to a depth of about 0.5 {mu}m from the surface in these systems and clearly indicates that adsorbed onto the surface is, surfactant layer which is insensitive to shear. The depth probed by the NSSANS is on the order of 20-30 {mu}m and is determined by the transmission of the sample, the angle of incidence, and the wavelength. In this region, the rods align under shear into a remarkably well ordered hexagonal crystal. The SANS from the Couette cell averages over the entire sample, so that the signal is dominated by scattering from the bulk. While the near surface hexagonal structure is clearly visible, these data are not consistent with the crystal structure persisting throughout the bulk, leading to the postulate that the bulk structure is a two dimensional (2D) liquid where the rods align with the flow, but do not order in the other two dimensions.

Butler, P.D.; Hamilton, W.A.; Magid, L.J. [and others

1996-12-31

169

Analyse syntaxique application aux langues naturelles  

E-print Network

· Computers and the Humanities · Computer, Speech & Language · Computer Assisted Language Learning Systran) · Bons traducteurs dans un domaine spécialisé pour préparer le terrain à une traduction par un

Schmitz, Sylvain

170

Surfactant Aggregates at Rough Solid-Liquid Interfaces Hannes C. Schniepp, Ho C. Shum, Dudley A. Saville, and Ilhan A. Aksay*  

E-print Network

Surfactant Aggregates at Rough Solid-Liquid Interfaces Hannes C. Schniepp, Ho C. Shum, Dudley A force microscopic imaging of surfactant surface aggregates, featuring an increase in the topography contrast by several hundred percent with respect to all previous studies. Surfactant aggregates on rough

Aksay, Ilhan A.

171

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...

172

Roles and activities of Aux\\/IAA proteins in Arabidopsis  

Microsoft Academic Search

Auxin induces various distinct developmental responses, partly by regulating gene expression. The Aux\\/IAA genes are a large gene family, many of which are induced by auxin. Work on ArabidopsisAux\\/IAA genes has begun to reveal that they can regulate development and auxin-induced gene expression. Furthermore, auxin responses require Aux\\/IAA protein turnover. Finally, recent evidence suggests that Aux\\/IAA proteins can mediate light

Jason W Reed

2001-01-01

173

Aux\\/IAA Proteins Contain a Potent Transcriptional Repression Domain  

Microsoft Academic Search

Aux\\/IAA proteins are short-lived nuclear proteins that repress expression of primary\\/early auxin response genes in protoplast transfection assays. Repression is thought to result from Aux\\/IAA proteins dimerizing with auxin response factor (ARF) transcriptional activators that reside on auxin-responsive promoter elements, referred to as AuxREs. Most Aux\\/IAA proteins contain four conserved domains, designated domains I, II, III, and IV. Domain II

Shiv B. Tiwari; Gretchen Hagen; Tom J. Guilfoyle

2004-01-01

174

Cinétique de photodéposition aux temps longs et réalisation de réseaux permanents modulables  

NASA Astrophysics Data System (ADS)

La cinétique de photodéposition aux temps longs est étudiée expérimentalement dans une solution à base de chromate et théoriquement en utilisant un modèle thermodynamique de croissance de goutte. Un comportement universel de la croissance aux temps longs est alors trouvé. L'application de la photodéposition à la réalisation de réseaux holographiques est montrée et l'ajustement du modèle à partir de la figure de diffraction expérimentale permet de remonter à l'évolution temporelle de la morphologie induite par le champ laser.

Hugonnot, E.; Delville, J. P.

2002-06-01

175

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

176

Comparison study of solid/liquid separation techniques for oilfield pit closures  

SciTech Connect

Vacuum filtration, belt-press filtration, screw-press filtration, and centrifuging techniques were evaluated in full-scale experiments for use in oilfield waste volume reduction. Centrifuging and belt-press filtration proved applicable to oilfield pit cleanups. Also, an effective chemical conditioning (coagulation and flocculation) was found for deliquoring seven types of oilfield waste slurries before separation.

Wojtanowicz, A.K.; Field, S.D.; Osterman, M.C.

1987-07-01

177

The Little Heat Engine: Heat Transfer in Solids, Liquids and Gases  

Microsoft Academic Search

In this work, an introductory exposition of the laws of thermodynamics and radiative heat transfer is presented while exploring the concepts of the ideal solid, the lattice, and the vibrational, translational, and rotational degrees of freedom. Analysis of heat transfer in this manner helps scientists to recognize that the laws of thermal radiation are strictly applicable only to the ideal

Pierre-Marie Robitaille

2007-01-01

178

Pathologie vgtale (synthse) Rsistances aux herbicides  

E-print Network

Pathologie végétale (synthèse) Résistances aux herbicides chez les mauvaises herbes H Darmency J; accepté le 27 mai 1990) Résumé — L'usage inconsidéré des herbicides pour un désherbage systématique des grandes cultures a conduit à l'apparition de mauvaises herbes résistantes. Huit familles d'herbicides

Boyer, Edmond

179

Synthesis of new phosphorus-containing (co)polyesters using solid-liquid phase transfer catalysis and product characterization.  

PubMed

This paper is directed towards the development of safe, and thermally stable solid polymer electrolytes. Linear phosphorus-containing (co)polyesters are described, including their synthesis, thermal analysis, conductivity, and non-flammability. Polycondensation of phenylphosphonic dichloride (PPD) with poly(ethylene glycol) (PEG 12000) with and without bisphenol A (BA) was carried out using solid-liquid phase transfer catalysis. Potassium phosphate is used as base. Yields in the range of 85.0-88.0%, and inherent viscosities in the range of 0.32-0.58 dL/g were obtained. The polymers were characterized by gel permeation chromatography, FT-IR, (1)H- and (31)P-NMR spectroscopy and thermal analysis. Their flammability was investigated by measuring limiting oxygen index values. The polymers are flame retardants and begin to lose weight in the 190 °C-231 °C range. Solid phosphorus- containing (co)polyesters were complexed with lithium triflate and the resulting ionic conductivity was determined. Conductivities in the range of 10(-7)-10(-8) S cm(-1) were obtained. PMID:22850325

Iliescu, Smaranda; Augusti, Maite-Gyl; Fagadar-Cosma, Eugenia; Plesu, Nicoleta; Fagadar-Cosma, Gheorghe; Macarie, Lavinia; Popa, Adriana; Ilia, Gheorghe

2012-01-01

180

Toluene biodegradation in a solid/liquid system involving immobilized activated sludge and silicone oil as pollutant reservoir.  

PubMed

A solid/liquid system involving activated sludge immobilized in an agar medium and a non-aqueous phase liquid containing the target pollutant has been considered to treat a model hydrophobic volatile organic compound, toluene. The positive impact of the use of a multiphase bioreactor is that the organic phase constitutes a pollutant reservoir and also helps to overcome possible pollutant toxicity. In addition and to overcome the drawbacks of the use of a solid organic phase (high pressure drop and low mass transfer) instead of a liquid organic phase, the considered solid phase was the aqueous. Consequently, silicone oil (polydimethylsiloxane) which showed its relevance for implementation in multiphase bioreactors was used. Promising results were observed from the analysis of toluene in the gaseous phase; for an initial amount of 2?g?L(-1) related to the organic phase, a v/v ratio of 0.5 of the organic phase to the aqueous agar phase, total toluene consumption was observed in about 9 days, leading to a global biodegradation rate of approximately 3.1?mg?L(-1)?h(-1), namely in the range of values previously observed in liquid/liquid systems. PMID:25187471

Diz Castro, Manuel; Gómez-Díaz, Diego; Amrane, Abdeltif; Couvert, Annabelle

2015-02-01

181

New best estimates for radionuclide solid-liquid distribution coefficients in soils. Part 1: radiostrontium and radiocaesium.  

PubMed

Best estimates for the solid-liquid distribution coefficients (K(d)) of radiostrontium and radiocaesium for various soil types, were derived from geometric means (GM) calculated from grouping soils by texture and organic matter content, and also using soil cofactors governing soil-radionuclide interaction. The K(d) (Sr) GM for Sand, Loam, Clay and Organic groups were similar, although the value for the Sand group was significantly lower. The Sr cofactor approach, based on the ratios of cation exchange capacity (CEC) to Ca and Mg concentrations in the soil solution, leads to K(d) (Sr) GM with a lower variability, from which best estimates could be proposed. The K(d) (Cs) GM for Sand and Organic groups differed, although similar values were obtained for Loam and Clay groups. Grouping the K(d) (Cs) according to the Radiocaesium Interception Potential (RIP) and the RIP divided by the K concentration in the soil solution also allows to suggest K(d) (Cs) best estimates with a lower variability. PMID:19036483

Gil-García, C; Rigol, A; Vidal, M

2009-09-01

182

An in situ attenuated total reflection infrared study of a chiral catalytic solid-liquid interface: cinchonidine adsorption on pt.  

PubMed

An in situ attenuated total reflection study of the chiral solid-liquid interface created by cinchonidine adsorption on a Pt/Al(2)O(3) model catalyst is presented. Experiments were performed in the presence of dissolved hydrogen, that is under conditions used for the heterogeneous enantioselective hydrogenation of alpha-functionalized ketones. Cinchonidine adsorbs via the quinoline moiety. The adsorption mode is coverage dependent and several species coexist on the surface. At low concentration (10(-6)M) a predominantly flat adsorption mode prevails. At increasing coverage two different tilted species, alpha-H abstracted and N lone pair bonded cinchonidine, are observed. The latter is only weakly bound and in a fast dynamic equilibrium with dissolved cinchonidine. At high concentration (10(-4)-10(-3) M) all three species coexist on the Pt surface. A slow transition from an adsorbate layer with a high fraction of alpha-H abstracted cinchonidine to one with a high fraction of N lone pair bonded cinchonidine is observed with the cinchonidine concentration being the driving force for the process. The reverse transition in the absence of dissolved cinchonidine is fast. Cinchonidine competes with solvent decomposition products for adsorption sites on the Pt, which may contribute to the observed solvent dependence of the heterogeneous enantioselective hydrogenation of ketones by cinchonidine-modified Pt. PMID:11724616

Ferri, D; Bürgi, T

2001-12-01

183

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-García, Teodoro; Rodríguez-Presa, María José; Gervasi, Claudio; Moya, Sergio; Azzaroni, Omar

2013-07-16

184

Solid-liquid interfacial energy of neopentylglycol solid solution in equilibrium with neopentylglycol-(D) camphor eutectic liquid  

NASA Astrophysics Data System (ADS)

The grain boundary groove shapes for equilibrated solid neopentylglycol (NPG) solution (NPG-3 mol% D-camphor) in equilibrium with the NPG-DC eutectic liquid (NPG-36.1 mol% D-camphor) have been directly observed using a horizontal linear temperature gradient apparatus. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficient ( ?), solid-liquid interfacial energy ( ?SL) of NPG solid solution have been determined to be (7.5±0.7)×10 -8 K m and (8.1±1.2)×10 -3 J m -2, respectively. The Gibbs-Thomson coefficient versus Tm?1/3, where ? is the volume per atom was also plotted by linear regression for some organic transparent materials and the average value of coefficient ( ?) for nonmetallic materials was obtained to be 0.32 from graph of the Gibbs-Thomson coefficient versus Tm?1/3. The grain boundary energy of solid NPG solution phase has been determined to be (14.6±2.3)×10 -3 J m -2 from the observed grain boundary groove shapes. The ratio of thermal conductivity of equilibrated eutectic liquid to thermal conductivity of solid NPG solution was also measured to be 0.80.

Bayram, Ü.; Aksöz, S.; Mara?l?, N.

2012-01-01

185

Arrhenian and Non-Arrhenian Temperature Dependent Relaxation Time Development in the Solid-Liquid Transition Area of Amorphous Bodies  

NASA Astrophysics Data System (ADS)

The temperature-dependent changes of molecular and sub-molecular motions are studied in amorphous substances. The solid and liquid phases of amorphous bodies are characterized at the micro-level by two types of oscillators, linear and non-linear. It is accepted that an amorphous liquid is formed by domains that group the linear oscillators into the form of icebergs. The serial connection of the viscoelastic elements are arranged inside of these icebergs. The size of the linear connection within the domains is characterized by the number "n", which increases during the cooling process. The linear viscoelastic behavior of the individual serial connections is connected to the individual relaxation processes ?, ?, and ?. Only the "alpha" process exhibits growth of "n" to infinity on cooling. Therefore, the corresponding relaxation time, ??, for the infinite chain of "n" elements (Voigt or Maxwell elements) can also reach infinity as the material transforms to a glassy state. In contrast to the "alpha" process, the ? and ? processes are limited in growth for serial connections in a chain structure. Therefore, the relaxation times for the ? and ? processes, ?? and ??, will only follow the temperature dependence of the sample viscosity on cooling, which is, of course, Arrhenian. We discuss the role of non-linear oscillators in the solid-liquid transition in relation to Brownian motion.

Hlavá?ek, Bo?ivoj; Drašar, ?estmír; Kalendová, Andréa; Menc, Pavel; Veselý, David

186

Batch and semi-continuous anaerobic digestion of food waste in a dual solid-liquid system.  

PubMed

To avoid the inhibition from both of waste oil and high concentrations of cationic elements, anaerobic digestion of food waste in a dual solid-liquid (ADSL) system was examined in this present paper. Results from batch test indicated that a higher methane yield could be obtained in the ADSL system. The methane yield of food solid waste (FSW), food liquid waste (FLW) and raw food waste (RFW) were 643, 659 and 581 mL/g-VS, respectively. In semi-continuous anaerobic digestion, the optimum organic loading rates (OLR) for FSW, FLW and RFW were 9, 4 and 7 g-VS/L/d, respectively. The total methane production of RFW and ADSL systems, based on 1 kg-VS(RFW), were 405 and 460 L, respectively, indicating that the methane production increased by 13.6% in the ADSL system. The optimum C/N ratio, redistribution of metal element and lower content of waste oil in FSW explain the higher methane production. PMID:23561948

Zhang, Cunsheng; Su, Haijia; Tan, Tianwei

2013-10-01

187

Communication: Thermal rectification in liquids by manipulating the solid-liquid interface  

NASA Astrophysics Data System (ADS)

Thermal rectification, the origin of which lies in modifying the thermal resistance in a nonlinear manner, could significantly improve the thermal management of a wide range of nano-devices (both electronic and thermoelectric), thereby improving their efficiencies. Since rectification requires a material to be inhomogeneous, it has been typically associated with solids. However, the structure of solids is relatively difficult to manipulate, which makes the tuning of thermal rectification devices challenging. Since liquids are more amenable to tuning, this could open up new applications for thermal rectification. We use molecular dynamics simulations to demonstrate thermal rectification using liquid water. This is accomplished by creating an inhomogeneous water phase, either by changing the morphology of the surface in contact with the liquid or by imposing an arbitrary external force, which in practice could be through an electric or magnetic field. Our system consists of a bulk fluid that is confined in a reservoir that is bounded by two walls, one hot and the other cold. The interfacial (Kapitza) thermal resistance at the solid-fluid interface and the density gradient of the bulk fluid both influence the magnitude of the thermal rectification. However, we find that the role of the interfacial resistance is more prominent than the application of an external force on the bulk fluid.

Murad, Sohail; Puri, Ishwar K.

2012-08-01

188

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

189

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

190

Solid-liquid extraction of alkali metals and organic compounds by leaching of food industry residues.  

PubMed

Leaching was studied for its application in extracting inorganic and organic constituents from fresh fermented grape pomace, air-dried fermented grape pomace and air-dried sugar beet pulp. Samples of each feedstock were leached in water at ambient temperature for 30 or 120 min at dry solid-to-liquid ratios of 1/20 and 1/50 kg/L. Leaching removed 82% of sodium, 86% of potassium, and 76% of chlorine from sugar beet pulp, and reduced total ash concentration in air-dry fermented grape pomace from 8.2% to 2.9% of dry matter, 8.2% to 4.4% in fresh fermented grape pomace, and 12.5% to 5.4% in sugar beet pulp. Glycerol (7-11 mg/dry g), ethanol (131-158 mg/dry g), and acetic acid (24-31 mg/dry g) were also extracted from fermented grape pomace. These results indicate that leaching is a beneficial pretreatment step for improving the quality of food processing residues for thermochemical and biochemical conversion. PMID:20153641

Yu, Chaowei; Zheng, Yi; Cheng, Yu-Shen; Jenkins, Bryan M; Zhang, Ruihong; VanderGheynst, Jean S

2010-06-01

191

The effects of surface curvature on the adsorption of surfactants at the solid-liquid interface.  

PubMed

The adsorption of surfactants from dilute oil solutions on to solid surfaces is studied as a function of surface curvature and surface coverage. Coarse-grained molecular models, computer simulations, and umbrella sampling are used to compute the dependence of the free energy of adsorption on to a spherical colloid surface with radius R. It is shown that for fixed surface coverage, and with all other things being equal, the free energy of adsorption decreases with decreasing R. For fixed surface curvature, the free energy of adsorption increases with increasing surface coverage. These trends arise from the excluded-volume interactions between the surfactant tails. The dependence on surface curvature is due to the geometrical effect of there being more free volume for the surfactant tails with a smaller colloid radius. The consequences of these effects on equilibrium partitioning are examined. It is shown that for surfactants adsorbed on small-colloid and large-colloid surfaces in mutual equilibrium with a dilute solution, the surface coverage of the small particles is significantly greater. The implications for industrial applications are discussed and could be significant. PMID:23588901

Farrow, Matthew R; Camp, Philip J; Dowding, Peter J; Lewtas, Ken

2013-07-28

192

PRECONCENTRATION AND DETERMINATION OF ?;-BLOCKERS USING CARBON NANOTUBE ASSISTED PSEUDO-STIRBAR HOLLOW FIBER SOLID\\/LIQUID PHASE MICROEXTRACTION AND HIGH PERFORMANCE LIQUID CHROMATOGRAPHY WITH FLUORESCENCE DETECTION  

Microsoft Academic Search

A method termed pseudo-stir bar hollow fiber solid\\/liquid phase microextraction (HF-SLPME) was utilized to extract three ?-blockers; atenolol, metoprolol and propranolol in environmental waters. The extracted ?-blockers were then separated, identified, and quantified by high performance liquid chromatography with fluorescence detection. In HF-SLPME a porous polypropylene hollow fiber filled with MWCNTs reinforced organic solvent that acts as an analyte trap

Ali Sarafraz-Yazdi; Mohamad Reza Abedi; Zarrin Eshaghi

2012-01-01

193

Solid–liquid extraction and cation-exchange solid-phase extraction using a mixed-mode polymeric sorbent of Datura and related alkaloids  

Microsoft Academic Search

Tropane alkaloids solid–liquid extraction methods were developed and comprised ambient pressure ones: extraction with hot solvent, extraction at room temperature, on ultrasonic bath as well as pressurised liquid extraction (PLE) techniques. The highest yields of l-hyoscyamine in methanol PLE method (3×5min, 110°C) and scopolamine extracted with 1% tartaric acid in methanol (15min, 90°C) were determined. A mixed-mode reversed-phase cation-exchange solid-phase

Tomasz Mroczek; Kazimierz G?owniak; Joanna Kowalska

2006-01-01

194

Liquid-vapor and solid-liquid-vapor phase equilibria in natural gas systems. Annual report 1 Jan 83-1 Jan 84  

SciTech Connect

Solid-liquid-vapor phase equilibria were measured for the binary systems carbon dioxide plus methane, carbon dioxide plus ethane, and carbon dioxide plus propane over the temperature region 204 to 216 K. Vapor-liquid phase equilibria were measured for carbon dioxide plus methane at 212 K, carbon dioxide plus ethane at 204, 209, and 212 K, and carbon dioxide plus propane at 216 K.

Kidney, A.J.; Sloan, E.D.

1984-01-01

195

Form-stable paraffin\\/high density polyethylene composites as solid–liquid phase change material for thermal energy storage: preparation and thermal properties  

Microsoft Academic Search

This paper deals with the preparation of paraffin\\/high density polyethylene (HDPE) composites as form-stable, solid–liquid phase change material (PCM) for thermal energy storage and with determination of their thermal properties. In such a composite, the paraffin (P) serves as a latent heat storage material and the HDPE acts as a supporting material, which prevents leakage of the melted paraffin because

Ahmet Sar?

2004-01-01

196

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

Microsoft Academic Search

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

M. Song; A. Yoneda; E. Ito

2005-01-01

197

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

198

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, Benoît; Aerts, Luc; Leyssens, Tom

2012-11-01

199

Collaborateurs aux lignes directrices en soins primaires  

PubMed Central

Résumé Objectif Déterminer la profession des collaborateurs scientifiques aux lignes directrices, les variables associées aux différences de participation des collaborateurs et si oui ou non les lignes directrices en soins primaires fournissent un énoncé sur les conflits d’intérêts. Type d’étude Analyse rétrospective des lignes directrices en soins primaires affichées sur le site web de l’Association médicale canadienne. Deux extracteurs de données indépendants ont examiné les lignes directrices et ont extrait les données pertinentes. Contexte Canada Principaux paramètres à l’étude Commanditaires des lignes directrices, territoire (national ou provincial) visé par les lignes directrices, profession des collaborateurs scientifiques aux lignes directrices et énoncés de conflits d’intérêts rapportés dans les lignes directrices. Résultats Sur les 296 lignes directrices de pratique clinique trouvées dans la section de la médecine familiale de l’Infobanque AMC, 65 apparaissaient en double et 35 se rapportaient de façon limitée à la médecine familiale. Vingt ne fournissaient aucune information sur les collaborateurs scientifiques, ce qui laissait 176 lignes directrices propices à l’analyse. Au total, il y avait 2495 collaborateurs (auteurs et membres de comité) : 1343 (53,8 %) spécialistes autres que des médecins de famille, 423 (17,0 %) médecins de famille, 141 (5,7 %) infirmières, 75 (3,0 %) pharmaciens, 269 (10,8 %) autres cliniciens, 203 (8,1 %) scientifiques non cliniciens et 41 (1,6 %) collaborateurs de profession inconnue. La proportion des collaborateurs de ces professions différait significativement entre les lignes directrices nationales et provinciales, de même qu’entre les lignes directrices financées par l’industrie et celles qui ne l’étaient pas (p < 0,001 dans les 2 cas). Dans le cas des lignes directrices de pratique clinique provinciales, 30,8 % des collaborateurs étaient des médecins de famille et 37,3 % étaient d’autres spécialistes, comparativement à 13,9 % et à 57,4 %, respectivement, dans le cas des lignes directrices nationales. Parmi les lignes directrices financées par l’industrie, 7,8 % des collaborateurs étaient des médecins de famille et 68,6 % étaient d’autres spécialistes, comparativement à 19,4 % et à 49,9 %, respectivement, parmi les lignes directrices qui n’étaient pas financées par l’industrie. Les conflits d’intérêts n’étaient pas rapportés dans 68,9 % des cas. Lorsqu’ils l’étaient, les énoncés sur les conflits d’intérêts se rapportaient à 48,6 % aux spécialistes autres que les médecins de famille, à 30,0 % aux pharmaciens, à 27,7 % aux médecins de famille et à 10,0 % ou moins aux autres groupes; les différences étaient statistiquement significatives (p < 0,001). Conclusion Les spécialistes autres que les médecins de famille sont plus nombreux que tous les autres fournisseurs de soins de santé et sont plus de 3 fois plus enclins à collaborer aux lignes directrices en soins primaires que ne le sont les médecins de famille. Les énoncés sur les conflits d’intérêts n’apparaissaient que dans une minorité de lignes directrices, et lorsqu’ils apparaissaient, les spécialistes autres que les médecins de famille étaient plus enclins à les rapporter. Les lignes directrices ciblant les médecins de famille devraient compter plus de médecins de famille et de soins primaires et moins de collaborateurs en conflit d’intérêts.

Allan, G. Michael; Kraut, Roni; Crawshay, Aven; Korownyk, Christina; Vandermeer, Ben; Kolber, Michael R.

2015-01-01

200

Huiles essentielles et bactéries résistantes aux antibiotiques  

Microsoft Academic Search

Résumé  L’objectif de ce travail est de faire un screening de l’activité antimicrobienne de 40 huiles essentielles sur deux souches\\u000a bactériennes résistantes aux antibiotiques (Staphylococcus aureus et Pseudomonas aeruginosa), souvent responsables de maladies nosocomiales, dans le dessein de créer des formulations d’huiles essentielles pour l’assainissement\\u000a de l’air en milieu hospitalier. S. aureus est une bactérie à Gram positif responsable d’infections des

V.-G. de Billerbeck

2007-01-01

201

L'Anse Aux Meadows, Newfoundland  

NASA Technical Reports Server (NTRS)

L'Anse aux Meadows is a site on the northernmost tip of the island of Newfoundland, located in the Province of Newfoundland and Labrador, Canada, where the remains of a Viking village were discovered in 1960 by the Norwegians Helge and Anne Ingstad. The only authenticated Viking settlement in North America outside Greenland, it was the site of a multi-year archaeological dig that found dwellings, tools and implements that verified its time frame. The settlement, dating more than five hundred years before Christopher Columbus, contains the earliest European structures in North America. Named a World Heritage site by UNESCO, it is thought by many to be the semi-legendary 'Vinland' settlement of explorer Leif Ericson around AD 1000. The settlement at L'Anse aux Meadows consisted of at least eight buildings, including a forge and smelter, and a lumber yard that supported a shipyard. The largest house measured 28.8 by 15.6 m and consisted of several rooms. Sewing and knitting tools found at the site indicate women were present at L'Anse aux Meadows

The image was acquired on September 14, 2007, covers an area of 14.2 x 14.6 km, and is located at 51.5 degrees north latitude, 55.6 degrees west longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

2008-01-01

202

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

SciTech Connect

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.

Yu, Tang-Qing, E-mail: tangqing.yu@nyu.edu; Vanden-Eijnden, Eric, E-mail: eve2@cims.nyu.edu [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States); Chen, Pei-Yang; Chen, Ming [Department of Chemistry, New York University, New York, New York 10003 (United States); Samanta, Amit [Program in Applied and Computational Mathematics, Princeton University, Princeton, New Jersey 08544, USA and Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Tuckerman, Mark, E-mail: mark.tuckerman@nyu.edu [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States); Department of Chemistry, New York University, New York, New York 10003 (United States); NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062 (China)

2014-06-07

203

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

204

Design and performance of BNR activated sludge systems with flat sheet membranes for solid-liquid separation.  

PubMed

The use of immersed membranes for solid-liquid separation in biological nutrient removal activated sludge (BNRAS) systems was investigated at lab scale. Two laboratory-scale BNR activated sludge systems were run in parallel, one a MBR system and the other a conventional system with secondary settling tanks. Both systems were in 3 reactor anaerobic, anoxic, aerobic UCT configurations. The systems were set up to have, as far as possible, identical design parameters such as reactor mass fractions, recycles and sludge age. Differences were the influent flow and total reactor volumes, and the higher reactor concentrations in the MBR system. The performances of the two systems were extensively monitored and compared to identify and quantify the influence of the membranes on system response. The MBR UCT system exhibited COD, FSA, TKN, TP and TSS removals that were consistently equivalent or superior to the conventional system. Better P removal in the MBR was attributed to lower observed P uptake in the anoxic zone. High nitrate loads to the anoxic reactor appeared to be the determining factor in stimulating P uptake. The MBR UCT system had a greater sludge production than the conventional system. This was partly attributable to the retention of all solids in the MBR reactor. For steady state design this increase is accommodated by increasing the influent unbiodegradable particulate COD fraction. Additionally an attempt was made to determine the Alpha values in the oxygen transfer rate. This paper briefly summarises and compares the results from both systems, and the conclusions that can be drawn from these results. PMID:17898449

du Toit, G J G; Ramphao, M C; Parco, V; Wentzel, M C; Ekama, G A

2007-01-01

205

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

NASA Astrophysics Data System (ADS)

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.

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

2014-06-01

206

Protein allostery at the solid-liquid interface: endoglucanase attachment to cellulose affects glucan clenching in the binding cleft.  

PubMed

At phase boundaries, physical activities of enzymes such as substrate complexation play critical roles in driving biocatalysis. A prominent example is the cellulase cocktails secreted by fungi and bacteria for deconstructing crystalline cellulose in biomass into soluble sugars. At interfaces, molecular mechanisms of the physical steps in biocatalysis remain elusive due to the difficulties of characterizing protein action with high temporal and spatial resolution. Here, we focus on endoglucanase I (Cel7B) from the fungus Trichoderma reesei that hydrolyzes glycosidic bonds on cellulose randomly. We employ all-atom molecular dynamics (MD) simulations to elucidate the interactions of the catalytic domain (CD) of Cel7B with a cellulose microfibril before and after complexing a glucan chain in the binding cleft. The calculated mechanical coupling networks in Cel7B-glucan and Cel7B-microfibril complexes reveal a previously unresolved allosteric coupling at the solid-liquid interface: attachment of the Cel7B CD to the cellulose surface affects glucan chain clenching in the binding cleft. Alternative loop segments of the Cel7B CD were found to affix to intact or defective surface structures on the microfibril, depending on the complexation state. From a multiple sequence alignment, residues in surface-affixing segments show strong conservation, highlighting the functional importance of the physical activities that they facilitate. Surface-affixing residues also demonstrate significant sequence correlation with active-site residues, revealing the functional connection between complexation and hydrolysis. Analysis of the Cel7B CD exemplifies that the mechanical coupling networks calculated from atomistic MD simulations can be used to capture the conservation and correlation in sequence alignment. PMID:21877736

Lin, Yuchun; Silvestre-Ryan, Jordi; Himmel, Michael E; Crowley, Michael F; Beckham, Gregg T; Chu, Jhih-Wei

2011-10-19

207

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, Ekhiñe; Iparragirre, Arantza; Navarro, Patricia; Prieto, Ailette; Fernández, Luis Ángel; Zuloaga, Olatz

2014-02-28

208

Solid-liquid equilibria of neptunium(V) in carbonate solutions of different ionic strengths: II. Stability of the solid phases  

Microsoft Academic Search

The solid-liquid equilibria of Np(V) have been studied at 25 °C in 0.1–5 M NaClO4 under 0.03% CO2 in argon and in 5 M NaCl under 1.0% CO2 in argon. The solid phases formed under given experimental conditions ([CO32?] = 10?8.0?10?0.3 mol 1?1, pH = 6.8?10.5) have been characterized by X-ray diffraction analysis. At carbonate concentrations less than 10?3 mol

V. Neck; W. Runde; J. I. Kim

1995-01-01

209

Solid–liquid and liquid–liquid equilibria for 1,3,5-trioxane, or 1,4,7,10,13,16-hexaoxacyclooctadecane + selected n-alkane mixtures  

Microsoft Academic Search

Solid–liquid and liquid–liquid equilibrium temperatures for mixtures of 1,3,5-trioxane, or 1,4,7,10,13,16-hexaoxacyclooctadecane with n-heptane, or with n-tridecane, or with n-hexadecane are reported. The equilibrium temperatures were measured by a dynamic method. Mixtures with n-tridecane, or n-hexadecane show a eutectic point. 1,4,7,10,13,16-Hexaoxacyclooctadecane present a transition point in solid phase, which depends on the solvent. Dipole–dipole interactions are stronger in solutions with 1,3,5-trioxane.Mixtures

U. Domanska; J. A. González

2003-01-01

210

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

211

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

212

Inverse method for the determination of a mathematical expression for the anisotropy of the solid-liquid interfacial energy in Al-Zn-Si alloys.  

PubMed

An expression for the anisotropy of the solid-liquid interfacial energy has been determined experimentally by an inverse method for the Al-43.4 wt%Zn-1.6 wt%Si system. Assuming that dendrite growth directions correspond to the minima of the surface stiffness, the anisotropy of the solid-liquid interfacial energy could be described by minimizing the errors between the calculated minima of a parametric interface stiffness function and experimentally measured growth directions of dendrites in thin coatings. In order to adequately describe the interfacial energy, it is found that a cubic harmonic expansion up to the third order is necessary to obtain the minima of interface stiffness along directions that depart from <100> or <110>. Best agreement with observed growth directions is obtained for first, second, and third harmonic coefficients (epsilon1, epsilon2, and epsilon3, respectively) satisfying the following relationships: epsilon2/epsilon1 = -0.188; epsilon3/epsilon1 = -0.00776. The corresponding interface stiffness function shows 24 minima lying along directions between <100> and <110>. The minima are located at 28.5 degrees from <100> and only 5.1 degrees from <320>, which was the growth direction suggested by Sémoroz for this alloy [A. Sémoroz, Y. Durandet, and M. Rappaz, Acta Mater. 49, 529 (2001).]. It was also found that the strength of the effective in-plane anisotropy is directly reflected by the morphology of the dendritic microstructure. PMID:17025443

Niederberger, C; Michler, J; Jacot, A

2006-08-01

213

Ultrasound assisted arylation of benzyl alcohol with 4-nitrochlorobenzene under a new multi-site phase-transfer catalyst in solid-liquid condition.  

PubMed

The ultrasound assisted preparation of 1-(benzyloxy)-4-nitrobenzene from the reaction of 4-chloronitrobenzene (CNB) and benzyl alcohol was carried out successfully using potassium hydroxide and catalyzed by a new multi-site phase-transfer catalyst (MPTC) viz., 1,3,5-triethyl-1,3,5-trihexyl-1,3,5-triazinane-1,3,5-triium trichloride in a solid-liquid reaction condition (SL-MPTC). The advantage of using SL-MPTC is to avoid a serious hydration of potassium salt of benzyl alcohol in the reaction between 4-chloronitrobenzene (CNB) and benzyl alcohol. The reaction is greatly enhanced in the solid-liquid system, catalyzed by multi-site quaternary ammonium salt (MPTC) and ultrasound irradiation (40 kHz, 300 W) in a batch reactor, it shows that the overall reaction greatly enhanced with ultrasound irradiation than without ultrasound. The reaction mechanism is proposed and verified by examining the experimental evidence. A kinetic model is proposed in which a pseudo first-order rate law is sufficient to describe the results, such as the effects of agitation speed, ultrasound, different phase transfer catalysts and the effect of organic solvents, the amount of newly prepared MPTC, the effect of temperature, the amount of water, the concentration of 4-chloronitrobenzene (CNB) and potassium hydroxide concentrations. The apparent rate constant (kapp) were investigated in detail. Rational explanations to account for the phenomena on the results were made. PMID:24830817

Selvaraj, Varathan; Abimannan, Pachaiyappan; Rajendran, Venugopal

2014-09-01

214

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

215

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

216

Auxin modulates the degradation rate of Aux\\/IAA proteins  

Microsoft Academic Search

Aux\\/IAA gene family members were first identified by their rapid transcriptional increase in response to auxin. Auxin\\/indole-3-acetic acid protein (Aux\\/IAA) luciferase (LUC) fusions expressed in Arabidopsis under control of a non-auxin-responsive promoter were used to monitor the effect of auxin on protein abundance independent of transcriptional regulation by auxin. After 2 hr in the presence of 1 muM exogenous dichlorophenoxyacetic

Nathan Zenser; Amanda Ellsmore; Colin Leasure; Judy Callis

2001-01-01

217

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

218

Comportement de frittés et de films d'oxyde de titane en présence d'atmosphères gazeuses, hors équilibre thermodynamique, en régime stationnaire; application aux capteurs résistifs d'oxygène  

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-stœchiométrie de l'oxyde de titane est étudiée, dans le domaine de température 870-1 100 K, en présence d'atmosphères hors équilibre thermodynamique, composées de CO, CO2, O2, Ar. La résistance électrique de différentes structures massives, poreuses ou en couches est mesurée, en régime stationnaire, en fonction du débit des gaz ; ces atmosphères sont d'autant plus éloignées de l'équilibre que le débit est élevé. On montre que les variations de résistance des échantillons, en fonction du débit, dépendent du domaine de pression partielle d'oxygène, de la température et de la structure des échantillons. La sensibilité à l'oxygène est accrue par un morphologie qui, à l'échelle macroscopique, favorise la diffusion de l'oxygène et qui, à l'échelle microscopique, permet la création de barrière de potentiel aux joints de grains. En milieu oxydant, à 870 K, un mécanisme de volume qui met en jeu la cinétique des échanges avec la phase gazeuse, détermine une variation de résistance en P_{O_2}^{1/4}/P_{CO}^{1/2}. En milieu réducteur, à la même température, la non-stœchiométrie en volume de l'oxyde est fixée par le couple redox CO/CO2 comme si l'atmosphère était en équilibre thermodynamique. Mais l'abondance des électrons de conduction, favorise la chimisorption de l'oxygène qui contrôle la résistance des couches selon une loi en P_{O_2}^{1/2} en créant des barrières de potentiel à la surface des grains. Des modèles, permettant le calcul du potentiel de surface ainsi que du taux de recouvrement, sont développés ; la comparaison des modèles indique une diffusion relativement lente des lacunes d'oxygène à 870 K. A 1 100 K, l'atmosphère tend à être à l'équilibre thermodynamique : i) en atmosphère oxydante, tous les capteurs sont en équilibre avec la pression partielle d'oxygène ; ii) en atmosphère réductrice, dominée par le couple redox CO/CO2, seules les couches sont sensibles à la présence de traces d'oxygène.

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

1992-04-01

219

Extending atomistic simulation timescale in solid/liquid systems: Crystal growth from solution by a parallel-replica dynamics and continuum hybrid method  

SciTech Connect

Deposition of solid material from solution is ubiquitous in nature. However, due to the inherent complexity of such systems, this process is comparatively much less understood than deposition from a gas or vacuum. Further, the accurate atomistic modeling of such systems is computationally expensive, therefore leaving many intriguing long-timescale phenomena out of reach. We present an atomistic/continuum hybrid method for extending the simulation timescales of dynamics at solid/liquid interfaces. We demonstrate the method by simulating the deposition of Ag on Ag (001) from solution with a significant speedup over standard MD. The results reveal specific features of diffusive deposition dynamics, such as a dramatic increase in the roughness of the film.

Lu, Chun-Yaung; Voter, Arthur F.; Perez, Danny, E-mail: danny-perez@lanl.gov [Theoretical Division T-1, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division T-1, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2014-01-28

220

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

Yáñez, Karen P; Martín, María T; Bernal, José L; Nozal, María J; Bernal, José

2014-02-01

221

New best estimates for radionuclide solid-liquid distribution coefficients in soils. Part 3: miscellany of radionuclides (Cd, Co, Ni, Zn, I, Se, Sb, Pu, Am, and others).  

PubMed

New best estimates for the solid-liquid distribution coefficient (K(d)) for a set of radionuclides are proposed, based on a selective data search and subsequent calculation of geometric means. The K(d) best estimates are calculated for soils grouped according to the texture and organic matter content. For a limited number of radionuclides this is extended to consider soil cofactors affecting soil-radionuclide interaction, such as pH, organic matter content, and radionuclide chemical speciation. Correlations between main soil properties and radionuclide K(d) are examined to complete the information derived from the best estimates with a rough prediction of K(d) based on soil parameters. Although there are still gaps for many radionuclides, new data from recent studies improve the calculation of K(d) best estimates for a number of radionuclides, such as selenium, antimony, and iodine. PMID:19111373

Gil-García, C; Tagami, K; Uchida, S; Rigol, A; Vidal, M

2009-09-01

222

Performance and techno-economic assessment of several solid-liquid separation technologies for processing dilute-acid pretreated corn stover.  

PubMed

Solid-liquid separation of pretreated lignocellulosic biomass slurries is a critical unit operation employed in several different processes for production of fuels and chemicals. An effective separation process achieves good recovery of solute (sugars) and efficient dewatering of the biomass slurry. Dilute acid pretreated corn stover slurries were subjected to pressure and vacuum filtration and basket centrifugation to evaluate the technical and economic merits of these technologies. Experimental performance results were used to perform detailed process simulations and economic analysis using a 2000 tonne/day biorefinery model to determine differences between the various filtration methods and their process settings. The filtration processes were able to successfully separate pretreated slurries into liquor and solid fractions with estimated sugar recoveries of at least 95% using a cake washing process. A continuous vacuum belt filter produced the most favorable process economics. PMID:24995879

Sievers, David A; Tao, Ling; Schell, Daniel J

2014-09-01

223

In situ infrared monitoring of the solid/liquid catalyst interface during the three-phase hydrogenation of nitrobenzene over nanosized Au on TiO2.  

PubMed

The three-phase hydrogenation of nitrobenzene catalysed by nanosized gold over titania was investigated in a slurry. Simultaneous in situ ATR-FTIR monitoring of the liquid phase and at the solid/liquid catalyst interface identified the species adsorbed on the catalyst and those in the liquid phase during the reaction. Nitrosobenzene was not detected analytically while the spectroscopic measurements strongly indicated phenylhydroxylamine as an intermediate reacting before desorbing from the catalyst surface. Under the same reaction conditions, azobenzene and hydrazobenzene were identified as intermediates during the hydrogenation of azoxybenzene to aniline. When nitrosobenzene or phenylhydroxylamine was alternately fed as reactant, azoxybenzene was produced via a disproportionation route. With the former, azoxybenzene was not further reduced by hydrogen because nitrosobenzene deactivated the catalyst. Combined with H(2) uptake, the spectroscopic measurements provided new insights into the reaction mechanism of the gold catalysed hydrogenation of nitrobenzene and an update of the corresponding kinetics. PMID:21660327

Richner, Gilles; van Bokhoven, Jeroen A; Neuhold, Yorck-Michael; Makosch, Martin; Hungerbühler, Konrad

2011-07-21

224

The movement of particles in liquid metals under gravity forces and the interaction of particles with advancing solid-liquid interface  

NASA Technical Reports Server (NTRS)

The problems of shrinkage and gas porosity are discussed. Gravity forces enhance the removal of gas bubbles from a metal melt and contribute to the feeding of shrinkage porosity in castings. Experiments are reviewed which determine how large a density difference is required for metal particles to float or sink in a metal melt and to what extent do factors not considered in Stokes Law influence particle movement in a real system. As to the interaction of particles with an advancing solid-liquid interface, the results indicate that the metal particles are not rejected in a metal melt, and that concentrations of particles in a metal following solidification are due to other factors.

Weinberg, F.

1984-01-01

225

Soins Aux Brules Apres Un Accident Nucleaire  

PubMed Central

Summary Les lésions radiques sont dues le plus souvent à des radio-isotopes utilisés dans l’industrie. L’explosion d’un réacteur nucléaire, les armes nucléaires ou une attaque terroriste constituent un risque d’afflux massif de victimes brûlées. Les radiations ionisantes occasionnent des brûlures thermiques, des syndromes d’irradiation aiguë avec pancytopénie et des signes cutanés retardés. Après une période de latence, des symptômes cutanés apparaissent et leur profondeur est proportionnelle à la dose reçue. Les protocoles habituels de réanimation des brûlés s’appliquent ici. Les soins aux irradiés nécessitent aussi une mesure de l’irradiation et une décontamination par des personnels entraînés. En cas de catastrophe nucléaire, la priorité est d’optimiser les structures existantes et de préserver les moyens pour les patients ayant la plus forte probabilité de survie. Après un accident nucléaire isolé, les difficultés dans les centres de brûlés sont l’évaluation de la profondeur et les techniques chirurgicales de couverture cutanée. La préparation des moyens médicaux et des centres de brûlés est nécessaire pour faire face à la prise en charge de ces brûlures différentes et complexes. PMID:21991218

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

2010-01-01

226

Contrasting Modes of Diversification in the Aux/IAA and ARF Gene Families1[w  

E-print Network

Contrasting Modes of Diversification in the Aux/IAA and ARF Gene Families1[w] David L. Remington families in plants. The Aux/IAA and ARF gene families, consisting of 29 and 23 loci in Arabidopsis morphological development. We developed scenarios for the genomic proliferation of the Aux/IAA and ARF families

Remington, David

227

Christian HOTTIN Les monuments commmoratifs ddis aux savants -1999 LES MONUMENTS COMMEMORATIFS  

E-print Network

Christian HOTTIN ­ Les monuments commémoratifs dédiés aux savants - 1999 1 LES MONUMENTS COMMEMORATIFS DEDIES AUX UNIVERSITAIRES ET AUX SAVANTS : ENTRE ESPACE COMMUNAUTAIRE ET ESPACE PUBLIC Christian.hottin@culture.gouv.fr INTRODUCTION Tout autant que les hommes politiques ou les gens de lettres, les universitaires et les savants

Paris-Sud XI, Université de

228

High pressure in situ x-ray absorption spectroscopy cell for studying simultaneously the liquid phase and the solid-liquid interface  

SciTech Connect

A high pressure in situ x-ray absorption spectroscopy cell with two different path lengths and path positions is presented for studying element-specifically both the liquid phase and the solid-liquid interface at pressures up to 250 bar and temperatures up to 220 deg. C. For this purpose, one x-ray path probes the bottom, while the other x-ray path penetrates through the middle of the in situ cell. The basic design of the cell resembles a 10 ml volume batch reactor, which is equipped with in- and outlet lines to dose compressed gases and liquids as well as a stirrer for good mixing. Due to the use of a polyetheretherketone inset it is also suitable for measurements under corrosive conditions. The characteristic features of the cell are illustrated using case studies from catalysis and solid state chemistry: (a) the ruthenium-catalyzed formylation of an amine in 'supercritical' carbon dioxide in the presence of hydrogen; (b) the cycloaddition of carbon dioxide to propylene oxide in the presence of a solid Zn-based catalyst, and (c) the solvothermal synthesis of MoO{sub 3} nanorods from MoO{sub 3}-2H{sub 2}O.

Grunwaldt, Jan-Dierk; Ramin, Michael; Rohr, Markus; Michailovski, Alexej; Patzke, Greta R.; Baiker, Alfons [Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology, ETH Hoenggerberg HCI, CH-8093 Zurich (Switzerland)

2005-05-15

229

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

230

Simultaneous analysis of carotenoids and tocopherols in botanical species using one step solid-liquid extraction followed by high performance liquid chromatography.  

PubMed

Carotenoids and tocopherols from botanical species abundant in Atlantic mountain grasslands were simultaneously extracted using one-step solid-liquid phase. A single n-hexane/2-propanol extract containing both types of compounds was injected twice under two different sets of HPLC conditions to separate the tocopherols by normal-phase chromatography and carotenoids by reverse-phase mode. The method allowed reproducible quantification in plant samples of very low amounts of ?-, ?-, ?- and ?-tocopherols (LOD from 0.0379 to 0.0720 ?g g(-1) DM) and over 15 different xanthophylls and carotene isomers. The simplified one-step extraction without saponification significantly increased the recovery of tocopherols and carotenoids, thereby enabling the determination of ?-tocopherol acetate in plant samples. The two different sets of chromatographic analysis provided near baseline separation of individual compounds without interference from other lipid compounds extracted from plants, and a very sensitive and accurate detection of tocopherols and carotenoids. The detection of minor individual components in botanical species from grasslands is nowadays of high interest in searching for biomarkers for foods derived from grazing animals. PMID:25466080

Valdivielso, Izaskun; Bustamante, María Ángeles; Ruiz de Gordoa, Juan Carlos; Nájera, Ana Isabel; de Renobales, Mertxe; Barron, Luis Javier R

2015-04-15

231

Proposal for new best estimates for the soil solid-liquid distribution coefficient and soil-to-plant transfer of nickel.  

PubMed

The objective of this study was to compile data, based on an extensive literature survey, for the soil solid-liquid distribution coefficient (K(d)) and soil-to-plant transfer factor (TF) for nickel. The K(d) best estimates were calculated for soils grouped according to texture and organic matter content (sand, loam, clay and organic) and soil cofactors affecting soil-nickel interaction, such as pH, organic matter, and clay content. Variability in K(d) was better explained by pH than by soil texture. Nickel TF estimates were presented for major crop groups (cereals, leafy vegetables, non-leafy vegetables, root crops, tubers, fruits, herbs, pastures/grasses and fodder), and also for plant compartments within crop groups. Transfer factors were also calculated per soil group, as defined by their texture and organic matter content. Furthermore an evaluation of transfer factor dependency on specific soil characteristics was performed following regression analysis. The derived estimates were compared with parameter estimates currently in use. PMID:19223096

Vandenhove, Hildegarde; Van Hees, May; Olyslaegers, Geert; Vidal, Miquel

2009-04-01

232

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

233

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.-Ming; Downs, R.T.; Pitzer, K.S.

1992-01-01

234

2D analogues of the inverted hexagonal phase self-assembled from 4,6-dialkoxylated isophthalic acids at solid-liquid interfaces  

NASA Astrophysics Data System (ADS)

Self-assembly of organic molecules at solid-liquid interfaces is a route for developing novel functional materials on surfaces and modeling assembly phenomena in 3D. 5-Alkoxylated isophthalic acids (ISA) are known to self-assemble into two-dimensional (2D) lamellae at the interface between a surface of Au(111) or HOPG (highly oriented pyrolytic graphite) and a solvent. Presently, the self-assembly of 4,6-dialkoxylated isophthalic acid derivatives with variable alkyl chain length is investigated at Au(111)-water, Au(111)-tetradecane and HOPG-tetradecane interfaces with a particular focus on the first one. The main aspect of this study is to evaluate the role of the molecular geometry and different interactions in the 2D assembly of amphiphilic molecules. In contrast to 5-alkoxylated ISA, 4,6-dialkoxylated ISA derivatives self-assemble preferentially into arrays of cyclic pentameric/hexameric structures, which appear as 2D analogues of the inverted hexagonal phase of lipids. As a general trend, the derivatives bearing shorter alkyl chains show a higher level of ordering at Au(111)-liquid interfaces. In particular, at the Au(111)-water interface, the 4,6-diheptyloxy ISA derivative forms exclusively pentamers, which are arranged in a quasi-hexagonal lattice. Moreover, the cyclic pentameric features are not empty but host a single isophthalic acid residue which is found to be dynamic. Finally, the packing of the diheptyloxy derivative shows a distinct potential dependence: while at more negative potentials the pentameric arrangement is converted into lamellae, at more positive potentials a loosely packed zig-zag pattern is formed. The present results show that at different solid-liquid interfaces 4,6-dialkoxylated ISA derivatives tend to form cyclic structures that are 2D analogues of an inverted hexagonal phase, akin to lipids having two hydrophobic alkyl chains and a small polar head group. Moreover, the substrate potential at the Au(111)-water interface can tune the 2D molecular arrangement.Self-assembly of organic molecules at solid-liquid interfaces is a route for developing novel functional materials on surfaces and modeling assembly phenomena in 3D. 5-Alkoxylated isophthalic acids (ISA) are known to self-assemble into two-dimensional (2D) lamellae at the interface between a surface of Au(111) or HOPG (highly oriented pyrolytic graphite) and a solvent. Presently, the self-assembly of 4,6-dialkoxylated isophthalic acid derivatives with variable alkyl chain length is investigated at Au(111)-water, Au(111)-tetradecane and HOPG-tetradecane interfaces with a particular focus on the first one. The main aspect of this study is to evaluate the role of the molecular geometry and different interactions in the 2D assembly of amphiphilic molecules. In contrast to 5-alkoxylated ISA, 4,6-dialkoxylated ISA derivatives self-assemble preferentially into arrays of cyclic pentameric/hexameric structures, which appear as 2D analogues of the inverted hexagonal phase of lipids. As a general trend, the derivatives bearing shorter alkyl chains show a higher level of ordering at Au(111)-liquid interfaces. In particular, at the Au(111)-water interface, the 4,6-diheptyloxy ISA derivative forms exclusively pentamers, which are arranged in a quasi-hexagonal lattice. Moreover, the cyclic pentameric features are not empty but host a single isophthalic acid residue which is found to be dynamic. Finally, the packing of the diheptyloxy derivative shows a distinct potential dependence: while at more negative potentials the pentameric arrangement is converted into lamellae, at more positive potentials a loosely packed zig-zag pattern is formed. The present results show that at different solid-liquid interfaces 4,6-dialkoxylated ISA derivatives tend to form cyclic structures that are 2D analogues of an inverted hexagonal phase, akin to lipids having two hydrophobic alkyl chains and a small polar head group. Moreover, the substrate potential at the Au(111)-water interface can tune the 2D molecular arrangement. Electronic supplementary information (ESI) avai

Klymchenko, Andrey S.; Furukawa, Shuhei; Balandina, Tanya; Müllen, Klaus; van der Auweraer, Mark; de Feyter, Steven

2010-09-01

235

Understanding the relationship between biotherapeutic protein stability and solid-liquid interfacial shear in constant region mutants of IgG1 and IgG4.  

PubMed

Relative stability of therapeutic antibody candidates is currently evaluated primarily through their response to thermal degradation, yet this technique is not always predictive of stability in manufacture, shipping, and storage. A rotating disk shear device is proposed that produces defined shear conditions at a known solid-liquid interface to measure stability in this environment. Five variants of IgG1 and IgG4 antibodies were created using combinations of two discrete triple amino acid sequence mutations denoted TM and YTE. Antibodies were ranked for stability based on shear device output (protein decay coefficient, PDC), and compared with accelerated thermal stability data and the melting temperature of the CH2 domain (Tm 1) from differential scanning calorimetry to investigate technique complimentarity. Results suggest that the techniques are orthogonal, with thermal methods based on intramolecular interaction and shear device stability based on localized unfolding revealing less stable regions that drive aggregation. Molecular modeling shows the modifications' effects on the antibody structures and indicates a possible role for Fc conformation and Fab-Fc docking in determining suspended protein stability. The data introduce the PDC value as an orthogonal stability indicator, complementary to traditional thermal methods, allowing lead antibody selection based on a more full understanding of process stability. PMID:24357426

Tavakoli-Keshe, Roumteen; Phillips, Jonathan J; Turner, Richard; Bracewell, Daniel G

2014-02-01

236

Nanofluidics of thin polymer films: linking the slip boundary condition at solid-liquid interfaces to macroscopic pattern formation and microscopic interfacial properties.  

PubMed

If a thin liquid film is not stable, different rupture mechanisms can be observed causing characteristic film morphologies: spinodal dewetting and dewetting by nucleation of holes. This rupturing entails liquid flow and opens new possibilities to study microscopic phenomena. Here we use this process of dewetting to gain insight on the slip boundary condition at the solid-liquid interface. Having established hydrodynamic models that allow for the determination of the slip length in a dewetting experiment based on nucleation, we move on to the quantification and molecular description of slip effects in various systems. For the late stage of the dewetting process involving the Rayleigh-Plateau instability, several distinct droplet patterns can be observed. We describe the importance of slip in determining what pattern may be found. In order to control the slip length, we use polymeric liquids on different hydrophobic coatings of silicon wafers. We find that subtle changes in the coating can lead to large changes in the slip length. Thus, we gain insight into the question of how the structure of the substrate affects the slip length. PMID:24780402

McGraw, Joshua D; Bäumchen, Oliver; Klos, Mischa; Haefner, Sabrina; Lessel, Matthias; Backes, Sebastian; Jacobs, Karin

2014-08-01

237

Pseudo-stir bar hollow fiber solid/liquid phase microextraction combined with anodic stripping voltammetry for determination of lead and cadmium in water samples  

PubMed Central

A new procedure is presented for the determination of low concentrations of lead and cadmium in water samples. Ligand assisted pseudo-stir bar hollow fiber solid/liquid phase microextraction using sol–gel sorbent reinforced with carbon nanotubes was combined with differential pulse anodic stripping voltammetry for simultaneous determination of cadmium and lead in tap water, and Darongar river water samples. In the present work, differential pulse anodic stripping voltammetry (DPASV) using a hanging mercury drop electrode (HMDE) was used in order to determine the ultra trace level of lead and cadmium ions in real samples. This method is based on accumulation of lead and cadmium ions on the electrode using different ligands; Quinolin-8-ol, 5,7-diiodo quinoline-8-ol, 4,5-diphenyl-1H-imidazole-2(3H)-one and 2-{[2-(2-Hydroxy-ethylamino)-ethylamino]-methyl}-phenol as the complexing agent. The optimized conditions were obtained. The relationship between the peak current versus concentration was linear over the range of 0.05–500 ng mL?1 for Cd (II) and Pb (II). The limits of detection for lead and cadmium were 0.015 ng mL?1 and 0.012 ng mL?1, respectively. Under the optimized conditions, the pre-concentration factors are 2440 and 3710 for Cd (II) and Pb (II) in 5 mL of water sample, respectively. PMID:25685537

Es’haghi, Zarrin; Hoseini, Hasan Ali; Mohammadi-Nokhandani, Saeed; Ebrahimi, Javad

2013-01-01

238

Understanding the Relationship Between Biotherapeutic Protein Stability and Solid–Liquid Interfacial Shear in Constant Region Mutants of IgG1 and IgG4  

PubMed Central

Relative stability of therapeutic antibody candidates is currently evaluated primarily through their response to thermal degradation, yet this technique is not always predictive of stability in manufacture, shipping, and storage. A rotating disk shear device is proposed that produces defined shear conditions at a known solid–liquid interface to measure stability in this environment. Five variants of IgG1 and IgG4 antibodies were created using combinations of two discrete triple amino acid sequence mutations denoted TM and YTE. Antibodies were ranked for stability based on shear device output (protein decay coefficient, PDC), and compared with accelerated thermal stability data and the melting temperature of the CH2 domain (Tm1) from differential scanning calorimetry to investigate technique complimentarity. Results suggest that the techniques are orthogonal, with thermal methods based on intramolecular interaction and shear device stability based on localized unfolding revealing less stable regions that drive aggregation. Molecular modeling shows the modifications’ effects on the antibody structures and indicates a possible role for Fc conformation and Fab-Fc docking in determining suspended protein stability. The data introduce the PDC value as an orthogonal stability indicator, complementary to traditional thermal methods, allowing lead antibody selection based on a more full understanding of process stability. © 2013 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:437–444, 2014 PMID:24357426

Tavakoli-Keshe, Roumteen; Phillips, Jonathan J; Turner, Richard; Bracewell, Daniel G

2014-01-01

239

Pathologie vgtale Sensibilit aux Pythium et mauvaise germination  

E-print Network

Pathologie végétale Sensibilité aux Pythium et mauvaise germination en sol froid chez le haricot et de composés azotés en cours de germination, leurs téguments sont moins riches en leuco qualités de la variété Vernandon. haricot = Phaseolus vulgaris / germination / sol froid / Pythium Summary

Paris-Sud XI, Université de

240

, INRAAdaptation des Herbivores aux Theix 63122 Saint-Gens-Champanelle  

E-print Network

B. DUMONT , INRAAdaptation des Herbivores aux Milieux Theix 63122 Saint-Genès-Champanelle Déterminisme des choix alimentaires des herbivores au pâturage : principales théories Comment mieux gérer les zones agricoles en déprise ? Comment les herbivores peuvent-ils contribuer à entretenir ces espaces

Paris-Sud XI, Université de

241

Bienvenue aux gays du monde entier . Tourisme gay et mondialisation  

E-print Network

- 1 - « Bienvenue aux gays du monde entier ». Tourisme gay et mondialisation Emmanuel JAURAND-94010 CRETEIL Résumé Le tourisme gay est le tourisme identitaire et communautaire des homosexuels rapport à la globalisation, le tourisme gay peut apparaître paradoxal. Il repose en partie sur des

Paris-Sud XI, Université de

242

Plant embryogenesis requires AUX/LAX-mediated auxin influx.  

PubMed

The plant hormone auxin and its directional transport are known to play a crucial role in defining the embryonic axis and subsequent development of the body plan. Although the role of PIN auxin efflux transporters has been clearly assigned during embryonic shoot and root specification, the role of the auxin influx carriers AUX1 and LIKE-AUX1 (LAX) proteins is not well established. Here, we used chemical and genetic tools on Brassica napus microspore-derived embryos and Arabidopsis thaliana zygotic embryos, and demonstrate that AUX1, LAX1 and LAX2 are required for both shoot and root pole formation, in concert with PIN efflux carriers. Furthermore, we uncovered a positive-feedback loop between MONOPTEROS (ARF5)-dependent auxin signalling and auxin transport. This MONOPTEROS-dependent transcriptional regulation of auxin influx (AUX1, LAX1 and LAX2) and auxin efflux (PIN1 and PIN4) carriers by MONOPTEROS helps to maintain proper auxin transport to the root tip. These results indicate that auxin-dependent cell specification during embryo development requires balanced auxin transport involving both influx and efflux mechanisms, and that this transport is maintained by a positive transcriptional feedback on auxin signalling. PMID:25617434

Robert, Hélène S; Grunewald, Wim; Sauer, Michael; Cannoot, Bernard; Soriano, Mercedes; Swarup, Ranjan; Weijers, Dolf; Bennett, Malcolm; Boutilier, Kim; Friml, Ji?í

2015-02-15

243

Analyse des donnes fonctionnelles Une petite introduction aux SVM  

E-print Network

Analyse des données fonctionnelles Une petite introduction aux SVM SVM pour données fonctionnelles References Analyse de données fonctionnelles par Machines à Vecteurs de Support (SVM) Nathalie Villa Nathalie Villa SVM fonctionnels, Séminaire CANSO, Limoges #12;Analyse des données fonctionnelles Une petite

Villa-vialaneix, Nathalie

244

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

245

Étude des équilibres solide-liquide du système quaternaire réciproque H 2O?UO 2(NO 3) 2, H 2 O 2 ( HNO 3) 2 , UO 4. Partie 1. Méthodes et techniques d'étude  

Microsoft Academic Search

Hydrated uranium peroxide (UO4 · nH2O with n = 2, 4 or 92) can be obtained by the reaction between hydrogen peroxide and uranyl nitrate. The optimal conditions for obtaining these compounds in a nitric medium require knowledge of the solid-liquid equilibrium of the reciprocal quaternary system H2O?UO2(NO3)2, H2O2(HNO3)2, UO4. The spontaneous decomposition of hydrogen peroxide into water and oxygen

J. J Counioux; S Gentil; R Tenu

1995-01-01

246

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

247

Overview of applications of Laser-Induced Breakdown Spectroscopy (LIBS)  

SciTech Connect

Laser-induced breakdown spectroscopy (LIBS) is a method of performing elemental analyses of solids, liquids, and gases using the microplasma produced by a focused laser pulse. Because the microplasma is formed by optical radiation, LIBS has some important advantages compared to conventional laboratory based analytical methods. Three applications are discussed which use the LIBS method. 6 refs., 8 figs., 2 tabs.

Cremers, D.A.

1987-01-01

248

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

249

Report on some thermodynamic data for desulfurization processes. [Includes properties of aqueous ions and certain solid, liquid, aqueous and gaseous compounds  

SciTech Connect

Tables are presented here of values of thermochemical properties and processes at 298.15/sup 0/K for some substances of interest to DOE for flue gas desulfurization. The substances covered are (1) the aqueous ions: OH/sup -/, SO/sub 3//sup -2/, HSO/sub 3//sup -/, SO/sub 4//sup -2/, HSO/sub 4//sup -/, CO/sub 3//sup -2/, HCO/sub 3//sup -/, H/sup +/, Mn/sup +2/, Fe/sup +2/, Mg/sup +2/, Ca/sup +2/, Na/sup +/, and K/sup +/, and (2) solid, liquid, aqueous, and gaseous compounds or species formed from these ions. The tables contain the following: (1) the thermochemical property values, enthalpy of formation, ..delta../sub f/H/sup 0/, Gibbs energy of formation, ..delta../sub f/G/sup 0/, entropy, S/sup 0/, and heat capacity, C/sub p//sup 0/, all at 298.15/sup 0/K, as well as the enthalpy difference between 298.15/sup 0/K and 0/sup 0/K, H/sup 0/-H/sub o//sup 0/, for the basic species cited above; (2) the predicted values for ..delta..H/sup 0/, ..delta..G/sup 0/, ..delta..S/sup 0/, and ..delta..C/sub p//sup 0/ as well as log K (equilibrium constant) for the processes, or reactions, of importance to DOE, calculated from (1); (3) the property values, phi/sub L/, the relative apparent molar enthalpy, ..gamma../sub +-/, the mean ionic activity coefficient, and phi, the osmotic coefficient, for the binary aqueous systems at 298.15/sup 0/K, all as a function of concentration. Some documentation for (2) and (3) is provided. All of the values given are consistent with the NBS TN 270 Series.

Parker, V.B.; Staples, B.R.; Jobe, T.L. Jr.; Neumann, D.B.

1981-09-01

250

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 Å. 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

251

Infrared spectra of zinc guaiacolate and zinc oxide-guiacol cement systems: role of carboxylic acid in solid-liquid hardening reaction  

NASA Astrophysics Data System (ADS)

To elucidate the microscopic structure formation in the ZnO-guaiacol ( o-methoxyphenol, o-C 6H 4(OCH 3)OH) cement system and the role of carboxylic acid of a solid-liquid hardening reaction, IR spectra of guaiacol, zinc guaiacolate and the ZnO-guaiacol-CH 3COOH and CD 3COOD cement systems with various amounts of acid were recorded from 4000 to 200 cm -l. The spectra of Zn(CH 3COO) 2·2H 2O-guaiacol and ZnO-guaiacol-C 2H 5COOH systems were also examined. The IR bands due to the two types of metal-guaiacol complexes ? and ? were observed in the spectra of zinc guiacolate and the cement systems with various amounts of acid. The IR spectrum of the ? type zinc guaiacolate was found to be the same as that already reported in the literature to be a 1:2 complex. It was shown that the ? type complex was not an isolated compound but one produced in the system containing acid or zinc acetate by alteration of the ? type complex to the ? type one. In the spectra of the system containing acid or zinc acetate, extra bands due to a zinc acetato complex were observed in addition to those due to the ? type complex. This compound is insoluble in water unlike the usual zinc acetate. It has been suggested that this zinc acetato complex combines selectively with the ? type complex to form a ternary complex of the Zn(II) and acetate ions and guaiacol rather than simply mixing with the ? and ? type complexes in the cement system. In other words, 'the ? type complex' comes from the one part of this ternary complex and 'the zinc acetato complex' from the other part. Similar spectral features were also observed in the case of the ZnO-guaiacol-C 2H 5COOH system.

Omura, Yoko

1998-03-01

252

Protein-Protein Interactions among the Aux\\/IAA Proteins  

Microsoft Academic Search

The plant hormone indoleacetic acid (IAA) transcriptionally activates early genes in plants. The Aux\\/IAA family of early genes encodes proteins that are short-lived and nuclear-localized. They also contain a putative prokaryotic beta alpha alpha DNA binding motif whose formation requires protein dimerization. Here, we show that the pea PS-IAA4 and Arabidopsis IAA1 and IAA2 proteins perform homo- and heterotypic interactions

Jungmook Kim; Klaus Harter; Athanasios Theologis

1997-01-01

253

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

254

AUX\\/IAA Proteins Are Active Repressors, and Their Stability and Activity Are Modulated by Auxin  

Microsoft Academic Search

Aux\\/IAA genes are early auxin response genes that encode short-lived nuclear proteins with four conserved domains, referred to as I, II, III, and IV. Arabidopsis Aux\\/IAA proteins repressed transcription on auxin-responsive reporter genes in protoplast transfection assays. Mutations in domain II resulted in increased repression, whereas mutations in do- mains I and III partially relieved repression. Aux\\/IAA proteins fused to

Shiv B. Tiwari; Xiao-Jun Wang; Gretchen Hagen; Tom J. Guilfoyle

2001-01-01

255

Auxin regulates SCFTIR1-dependent degradation of AUX\\/IAA proteins  

Microsoft Academic Search

The plant hormone auxin is central in many aspects of plant development. Previous studies have implicated the ubiquitin-ligase SCFTIR1 and the AUX\\/IAA proteins in auxin response. Dominant mutations in several AUX\\/IAA genes confer pleiotropic auxin-related phenotypes, whereas recessive mutations affecting the function of SCFTIR1 decrease auxin response. Here we show that SCFTIR1 is required for AUX\\/IAA degradation. We demonstrate that

William M. Gray; Stefan Kepinski; Dean Rouse; Ottoline Leyser; Mark Estelle

2001-01-01

256

Solid-liquid extraction and cation-exchange solid-phase extraction using a mixed-mode polymeric sorbent of Datura and related alkaloids.  

PubMed

Tropane alkaloids solid-liquid extraction methods were developed and comprised ambient pressure ones: extraction with hot solvent, extraction at room temperature, on ultrasonic bath as well as pressurised liquid extraction (PLE) techniques. The highest yields of l-hyoscyamine in methanol PLE method (3 x 5 min, 110 degrees C) and scopolamine extracted with 1% tartaric acid in methanol (15 min, 90 degrees C) were determined. A mixed-mode reversed-phase cation-exchange solid-phase extraction (SPE) procedure was optimised for simultaneous recoveries of L-hyoscyamine, scopolamine, scopolamine-N-oxide from plant extracts as well as quaternary alkaloid representative: scopolamine-N-methyl bromide. First three alkaloids were efficiently eluted (recoveries 80-100%) from an Oasis MCX cartridge with methanol-10% ammonia (3:1, v/v) solution, whereas for the quaternary salt tetrahydrofuran-methanol-25% ammonia (6:1:3, v/v) was used with recoveries 52-6%. HPTLC-densitometric assay on silica gel plates was elaborated at 205 nm without derivatization and included: single development (over a distance 9.5 cm) with acetone-methanol-water-25% ammonia (85:5:5:8, v/v) mobile phase for L-hyoscyamine and scopolamine separation, whereas for scopolamine-N-oxide and scopolamine-N-methyl bromide a second development (to a distance 5.5 cm) with acetonitrile-methanol-85% formic acid (120:5:5, v/v) was applied. Newly elaborated RP-HPLC-diode array detection method was performed on Waters XTerra RP-18 column with gradient of acetonitrile in 15 mM ammonia solution and alkaloids were baseline separated within 20 min. Both chromatographic methods were validated and their quantitative results were compared. Good correlation between HPLC and HPTLC quantitative results was measured (correlation coefficients of mean values were 0.92086 and 0.99995 for L-hyoscyamine and scopolamine, respectively). In the RP-HPLC method, which was from 1.5- up to 7-fold more sensitive than HPTLC, limits of detection (LOD) and limits of quantitation (LOQ, in bracket) were (in ng/microl) as follows: 0.25 (0.82) for L-hyoscyamine, 0.29 (0.97) for scopolamine, 0.13 (0.45) for scopolamine-N-oxide and 0.58 (1.91) for scopolamine-N-methyl bromide. By the use of the optimised chromatographic methods, 14 various samples from the leaves and fruits of Datura sp. were screened for L-hyoscyamine and scopolamine contents and the most promising samples were established. PMID:16388811

Mroczek, Tomasz; G?owniak, Kazimierz; Kowalska, Joanna

2006-02-24

257

Expression and regulation of the early auxin-responsive Aux/IAA genes during strawberry fruit development.  

PubMed

The plant hormone auxin transcriptionally activates Aux/IAA genes. Auxin plays an important role in regulating fruit growth and ripening of strawberry and Aux/IAA genes have been extensively studied in Arabidopsis, rice and tomato, but little information is available on strawberry fruit. In the present work, two full-length of early auxin-responsive Aux/IAA genes, termed FaAux/IAA1 and FaAux/IAA2 respectively, were isolated and characterized from strawberry fruit. Moreover, the expression profiles of two FaAux/IAA genes during fruit development, and the effect of naphthalene acetic acid (NAA) on their expressions of fruits at two different developmental stages were also investigated. The results showed that the levels of FaAux/IAA1 and FaAux/IAA2 transcripts were very high at early stage of fruit development, and decreased sharply at ripening stage (after white stage). In addition, NAA applied at the stage of large green and white fruit obviously increased the accumulations of FaAux/IAA1 and FaAux/IAA2 transcripts. These data suggested that the expressions of both FaAux/IAA1 and FaAux/IAA2 genes were likely to be involved in early fruit development, and the enhancement of FaAux/IAAs transcripts might be attributed at least or partially to auxin-induced fruit growth and delayed fruit ripening of strawberry. PMID:20563652

Liu, Du-juan; Chen, Jian-ye; Lu, Wang-jin

2011-02-01

258

Thermodynamic Modeling of Aqueous Aluminum Chemistry and Solid-Liquid Equilibria to High Solution Concentration and Temperature. I. The Acidic H-Al-Na-K-Cl-H 2 O System from 0 to 100?°C  

Microsoft Academic Search

In this paper, we describe the development of a thermodynamic model that calculates solute\\/solvent activities and solid-liquid\\u000a equilibria in the acidic aluminum system, H-Al3+-Na-K-Cl-H2O, to high molality from 0?° to ?100?°C. The model incorporates the concentration-dependent, specific interaction equations\\u000a for aqueous solutions of Pitzer (Activity Coefficients in Electrolyte Solutions, 2nd edn., pp. 75–153, CRC Press, Boca Raton, 1991). Parameterization of this model

Christomir Christov; Andrew G. Dickson; Nancy Moller

2007-01-01

259

Study of melting and freezing processes of water for application to ice thermal energy storage system  

Microsoft Academic Search

This thesis presents the results of a study of the solid-liquid phase change process of water in a rectangular enclosure for application to thermal energy storage systems. The work performed combined experimental results with analytical and numerical methods to develop computer models of the system. Experiments were performed to obtain data to verify the models under various melting and freezing

Liang Yong

1993-01-01

260

Des furoncles résistants aux antibiotiques: penser à la myiase !!  

PubMed Central

Les myiases sont des infections parasitaires par des larves de mouches. La localisation cutanée doit être évoquée de retour d'un pays tropical devant une évolution inhabituelle de lésions cutanées. Nous rapportons une observation d'un militaire tunisien, ayant séjourné en République Démocratique du Congo. Il était atteint de myiase cutanée simulatrice d'une furonculose résistante aux antibiotiques. L'intérêt de cette observation est de souligner l'importance d’évoquer la myiase dont le traitement est simple et rapide chez un patient de retour de zone d'endémie. PMID:24106569

Ajili, Faida; Abid, Rim; Bousseta, Najeh; Mrabet, Ali; Karoui, Ghazi; Louzir, Bassem; Battikh, Riadh; Othmani, Salah

2013-01-01

261

Structure-Function Analysis of the Presumptive Arabidopsis Auxin Permease AUX1  

Microsoft Academic Search

We have investigated the subcellular localization, the domain topology, and the amino acid residues that are critical for the function of the presumptive Arabidopsis thaliana auxin influx carrier AUX1. Biochemical fractionation experiments and confocal studies using an N-terminal yellow fluorescent protein (YFP) fusion observed that AUX1 colocalized with plasma membrane (PM) markers. Because of its PM localization, we were able

Ranjan Swarup; Joanna Kargul; Alan Marchant; Daniel Zadik; Abidur Rahman; Rebecca Mills; Anthony Yemm; Lorraine Williams; Paul Millner; Seiji Tsurumi; Ian Moore; Richard Napier; Ian D. Kerr; Malcolm J. Bennetta

2004-01-01

262

Structure-Function Analysis of the Presumptive Arabidopsis Auxin Permease AUX1W?  

PubMed Central

We have investigated the subcellular localization, the domain topology, and the amino acid residues that are critical for the function of the presumptive Arabidopsis thaliana auxin influx carrier AUX1. Biochemical fractionation experiments and confocal studies using an N-terminal yellow fluorescent protein (YFP) fusion observed that AUX1 colocalized with plasma membrane (PM) markers. Because of its PM localization, we were able to take advantage of the steep pH gradient that exists across the plant cell PM to investigate AUX1 topology using YFP as a pH-sensitive probe. The YFP-coding sequence was inserted in selected AUX1 hydrophilic loops to orient surface domains on either apoplastic or cytoplasmic faces of the PM based on the absence or presence of YFP fluorescence, respectively. We were able to demonstrate in conjunction with helix prediction programs that AUX1 represents a polytopic membrane protein composed of 11 transmembrane spanning domains. In parallel, a large aux1 allelic series containing null, partial-loss-of-function, and conditional mutations was characterized to identify the functionally important domains and amino acid residues within the AUX1 polypeptide. Whereas almost all partial-loss-of-function and null alleles cluster in the core permease region, the sole conditional allele aux1-7 modifies the function of the external C-terminal domain. PMID:15486104

Swarup, Ranjan; Kargul, Joanna; Marchant, Alan; Zadik, Daniel; Rahman, Abidur; Mills, Rebecca; Yemm, Anthony; May, Sean; Williams, Lorraine; Millner, Paul; Tsurumi, Seiji; Moore, Ian; Napier, Richard; Kerr, Ian D.; Bennett, Malcolm J.

2004-01-01

263

L'apport d'internet aux Petites Entreprises (PE) touristiques dans la construction de leur  

E-print Network

RIPME L'apport d'internet aux Petites Entreprises (PE) touristiques dans la construction de leur auteur, publié dans "Revue Internationale PME 26, 1 (2013) xx-xx" #12;L'apport d'internet aux Petites les PE demeure faible (Eurostat 2010) et pourtant parmi les ap- plications IT, internet est pour les

Paris-Sud XI, Université de

264

Mesures de correlation robustes aux occultations Correlation measures that are robust near occlusions  

E-print Network

Mesures de corr´elation robustes aux occultations Correlation measures that are robust near`eme des occultations. Un protocole d'´evaluation est propos´e (huit crit`eres, trois paires d'images synth`eme famille), dont les seize mesures propos´ees, sont les plus robustes aux occultations. Mots Cl´es Corr

Paris-Sud XI, Université de

265

WORKING PAPER N 2009 -29 Mise aux normes des filires agro-alimentaires  

E-print Network

WORKING PAPER N° 2009 - 29 Mise aux normes des filières agro-alimentaires : Leçons de l'expérience internationale Mélise Jaud Codes JEL : F13, O13, Q17, Q18 Mots-clés : Filières agro-alimentaires, normes SPS, PED ­ ÉCOLE NORMALE SUPÉRIEURE halshs-00574965,version1-9Mar2011 #12;Mise aux normes des filières agro

Paris-Sud XI, Université de

266

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

267

Aux\\/IAA Proteins Repress Expression of Reporter Genes Containing Natural and Highly Active Synthetic Auxin Response Elements  

Microsoft Academic Search

A highly active synthetic auxin response element (AuxRE), referred to as DR5, was created by petforming site-directed mutations in a natural composite AuxRE found in the soybean GH3 promoter. DR5 consisted of tandem direct repeats of 11 bp that included the auxin-responsive TGTCTC element. The DR5 AuxRE showed greater auxin responsiveness than a natural composite AuxRE and the GH3 promoter

Tim Ulmasov; Jane Murfett; Gretchen Hagen; Tom J. Guilfoyle

1997-01-01

268

Phenotypes Associated with Down-Regulation of Sl-IAA27 Support Functional Diversity Among Aux/IAA Family  

E-print Network

Phenotypes Associated with Down-Regulation of Sl-IAA27 Support Functional Diversity Among Aux/IAA auxin is known to regulate several as- pects of plant development, and Aux/IAA transcription fac- tors play a pivotal role in auxin signaling. To extend our understanding of the multiple functions of Aux/IAAs

Paris-Sud XI, Université de

269

Conséquences comportementales de la violence faite aux enfants  

PubMed Central

Résumé Objectif Discuter des répercussions de la violence sur le développement comportemental durant l’enfance, mettre en évidence certains signes comportementaux susceptibles d’alerter les médecins à la présence d’une maltraitance continue d’un enfant et explorer le rôle précis du médecin de famille dans une telle situation clinique. Sources des données Une recension systématique a servi à examiner la recherche pertinente, les articles de révision clinique et les sites web des organismes de protection de la jeunesse. Message principal Le comportement d’un enfant est une manifestation extériorisée de sa stabilité et de sa sécurité intérieures. C’est une lentille au travers de laquelle le médecin de famille peut observer le développement de l’enfant pendant toute sa vie. Tous les genres de violence sont dommageables pour les enfants, qu’elle soit physique, affective ou psychologique, et peuvent causer des problèmes à long terme dans le développement du comportement et de la santé mentale. Les médecins de famille doivent connaître les indices de maltraitance et de négligence envers les enfants et être aux aguets de ces derniers afin d’entreprendre les interventions appropriées et améliorer les résultats pour ces enfants. Conclusion La violence faite aux enfants peut causer un développement psychologique désordonné et des problèmes de comportement. Les médecins de famille exercent un rôle important dans la reconnaissance des signes comportementaux laissant présager une maltraitance, ainsi que pour offrir de l’aide afin de protéger les enfants.

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

2013-01-01

270

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 VSD’s 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

271

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

The voltage-sensor domain (VSD) is a modular four-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., nonconducting 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 (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)) 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. E2011, 84, 031911-1-15). Here, we utilize neutron interferometry to characterize this system in substantially greater structural detail at the submolecular level, due to its inherent advantages arising from solvent contrast variation coupled with the deuteration of selected submolecular 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 VSD's water pore. This approach was extended to the full-length Kv-channel (KvAP) at a 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

2012-07-17

272

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

273

Protein-protein interaction and gene co-expression maps of ARFs and Aux/IAAs in Arabidopsis.  

PubMed

The phytohormone auxin regulates nearly all aspects of plant growth and development. Based on the current model in Arabidopsis thaliana, Auxin/indole-3-acetic acid (Aux/IAA) proteins repress auxin-inducible genes by inhibiting auxin response transcription factors (ARFs). Experimental evidence suggests that heterodimerization between Aux/IAA and ARF proteins are related to their unique biological functions. The objective of this study was to generate the Aux/IAA-ARF protein-protein interaction map using full length sequences and locate the interacting protein pairs to specific gene co-expression networks in order to define tissue-specific responses of the Aux/IAA-ARF interactome. Pairwise interactions between 19 ARFs and 29 Aux/IAAs resulted in the identification of 213 specific interactions of which 79 interactions were previously unknown. The incorporation of co-expression profiles with protein-protein interaction data revealed a strong correlation of gene co-expression for 70% of the ARF-Aux/IAA interacting pairs in at least one tissue/organ, indicative of the biological significance of these interactions. Importantly, ARF4-8 and 19, which were found to interact with almost all Aux-Aux/IAA showed broad co-expression relationships with Aux/IAA genes, thus, formed the central hubs of the co-expression network. Our analyses provide new insights into the biological significance of ARF-Aux/IAA associations in the morphogenesis and development of various plant tissues and organs. PMID:25566309

Piya, Sarbottam; Shrestha, Sandesh K; Binder, Brad; Stewart, C Neal; Hewezi, Tarek

2014-01-01

274

Auxin sensitivities of all Arabidopsis Aux/IAAs for degradation in the presence of every TIR1/AFB.  

PubMed

Auxin plays a key role in regulation of almost all processes of plant growth and development. Different physiological processes are regulated by different ranges of auxin concentrations; however, the underlying mechanisms creating these differences are largely unknown. The first step of auxin signaling is auxin-dependent interaction of an auxin receptor with transcriptional co-repressors (Aux/IAA), which leads to Aux/IAA degradation. Arabidopsis has six homologous auxin receptors (TIR1 and five AFBs), 29 Aux/IAA proteins and two types of active auxins, IAA and phenylacetic acid (PAA). Therefore, a large number of possible combinations between these three factors may contribute to the creation of complex auxin responses. Using a yeast heterologous reconstitution system, we investigated auxin-dependent degradation of all Arabidopsis Aux/IAAs in combination with every TIR or AFB receptor component. We found that TIR1 and AFB2 were effective in mediating Aux/IAA degradation. We confirmed that the Aux/IAA domain II, which binds TIR1, is essential for degradation. IAA and other natural auxins, 4-chloroindole-3-acetic acid (4-Cl-IAA) and PAA, induced Aux/IAA degradation; and IAA and 4-Cl-IAA had higher activity than PAA. Effective auxin concentrations for Aux/IAA degradation depended on both Aux/IAAs and TIR1 or AFB2 receptors, which is consistent with the Aux/IAA-TIR1/AFB co-receptor concept. PMID:24880779

Shimizu-Mitao, Yasushi; Kakimoto, Tatsuo

2014-08-01

275

Protein-protein interaction and gene co-expression maps of ARFs and Aux/IAAs in Arabidopsis  

PubMed Central

The phytohormone auxin regulates nearly all aspects of plant growth and development. Based on the current model in Arabidopsis thaliana, Auxin/indole-3-acetic acid (Aux/IAA) proteins repress auxin-inducible genes by inhibiting auxin response transcription factors (ARFs). Experimental evidence suggests that heterodimerization between Aux/IAA and ARF proteins are related to their unique biological functions. The objective of this study was to generate the Aux/IAA-ARF protein-protein interaction map using full length sequences and locate the interacting protein pairs to specific gene co-expression networks in order to define tissue-specific responses of the Aux/IAA-ARF interactome. Pairwise interactions between 19 ARFs and 29 Aux/IAAs resulted in the identification of 213 specific interactions of which 79 interactions were previously unknown. The incorporation of co-expression profiles with protein-protein interaction data revealed a strong correlation of gene co-expression for 70% of the ARF-Aux/IAA interacting pairs in at least one tissue/organ, indicative of the biological significance of these interactions. Importantly, ARF4-8 and 19, which were found to interact with almost all Aux-Aux/IAA showed broad co-expression relationships with Aux/IAA genes, thus, formed the central hubs of the co-expression network. Our analyses provide new insights into the biological significance of ARF-Aux/IAA associations in the morphogenesis and development of various plant tissues and organs. PMID:25566309

Piya, Sarbottam; Shrestha, Sandesh K.; Binder, Brad; Stewart, C. Neal; Hewezi, Tarek

2014-01-01

276

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. R�SUM� Mauvaise herbe, Setaria viridis L., Résistance chloroplasti- que, Résistance aux triazines, Détoxication des triazi- nes. Chez une espèce de la tribu des Panicoïdées (Setaria viridis L.) qui métabolise

Paris-Sud XI, Université de

277

Yokonolide B, a Novel Inhibitor of Auxin Action, Blocks Degradation of AUX/IAA Factors*S  

E-print Network

Yokonolide B, a Novel Inhibitor of Auxin Action, Blocks Degradation of AUX/IAA Factors*S ReceivedB is to block AUX/IAA protein degradation; how- ever, YkB is not a general proteasome inhibitor. YkB blocks 1. Gain of function mutants such as shy2-2, slr1, and axr2-1 encoding AUX/IAA transcriptional

Jones, Alan M.

278

Auxin-induced SCFTIR1Aux\\/IAA interaction involves stable modification of the SCFTIR1 complex  

Microsoft Academic Search

The plant hormone auxin can regulate gene expression by destabilizing members of the Aux\\/IAA family of transcriptional repressors. Auxin-induced Aux\\/IAA degradation requires the protein-ubiquitin ligase SCFTIR1, with auxin acting to enhance the interaction between the Aux\\/IAAs and SCFTIR1. SKP1, Cullin, and an F-box-containing protein (SCF)-mediated degradation is an important component of many eukaryotic signaling pathways. In all known cases to

Stefan Kepinski; Ottoline Leyser

2004-01-01

279

Réactions aux interfaces de bicristaux compatibles et incompatibles  

NASA Astrophysics Data System (ADS)

La rupture intergranulaire peut apparaître suite à la non accommodation des contraintes au voisinage de l'interface. La transmission du glissement au travers d'une interface est un des modes de relaxation possible qui dépend des paramètres suivants : facteurs géométriques (caractéristiques de l'interface et systèmes de glissement activés), constantes élastiques de chacune des phases. Dans cette étude, la microscopie électronique à transmission (MET) est utilisée pour analyser les configurations de dislocations résultant d'une déformation par fatigue de bicristaux d'acier austénoferritique de désorientations contrôlées. Deux types de bicristaux sont étudiés, compatible et incompatible plastiquement. Pour chacun d'eux, la déformation est initiée soit dans la phase ferritique ? soit dans la phase austénitique ? selon la localisation d'une entaille préalable à l'essai mécanique. Les résultats permettent de remonter aux mécanismes élémentaires qui régissent le transfert “direct” ou “indirect” des dislocations à travers l'interface. Une corrélation avec le comportement des bicristaux à l'échelle macroscopique est également tentée.

Taisne, A.; Décamps, B.; Priester, L.

2003-03-01

280

Floating-Point (Applications  

E-print Network

Number Theory and Floating-Point Numbers (Applications de la th#19; eorie des nombres aux An Interview with the Old Man of Floating-Point, interview from William Kahan (Turing Award 1989) by Charles on Floating-Point Invertible Numbers, 2001, to appear in Theoretical Computer Science. Theorem 1. For r = 0; 1

Zimmermann, Paul

281

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  

NASA Astrophysics Data System (ADS)

One subunit of the prokaryotic voltage-gated potassium ion channel from Aeropyrum pernix (KvAP) is comprised of six transmembrane ? helices, of which S1-S4 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 protein's 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.

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

2011-09-01

282

Ultrasound/microwave-assisted solid-liquid-solid dispersive extraction with high-performance liquid chromatography coupled to tandem mass spectrometry for the determination of neonicotinoid insecticides in Dendrobium officinale.  

PubMed

A one-step ultrasound/microwave-assisted solid-liquid-solid dispersive extraction procedure was used for the simultaneous determination of eight neonicotinoids (dinotefuran, nitenpyram, thiamethoxam, clothianidin, imidacloprid, acetamiprid, thiacloprid, imidaclothiz) in dried Dendrobium officinale by liquid chromatography combined with electrospray ionization triple quadrupole tandem mass spectrometry in multiple reaction monitoring mode. The samples were quickly extracted by acetonitrile and cleaned up by the mixed dispersing sorbents including primary secondary amine, C18 , and carbon-GCB. Parameters that could influence the ultrasound/microwave-assisted extraction efficiency such as microwave irradiation power, ultrasound irradiation power, temperature, and solvent were investigated. Recovery studies were performing well (70.4-113.7%) at three examined spiking levels (10, 50, and 100 ?g/kg). Meanwhile, the limits of quantification for the neonicotinoids ranged from 0.87 to 1.92 ?g/kg. The method showed good linearity in the concentration range of 1-100 ?g/L with correlation coefficients >0.99. This quick and useful analytical method could provide a basis for monitoring neonicotinoid insecticide residues in herbs. PMID:25348589

Zheng, Shuilian; Wu, Huizhen; Li, Zuguang; Wang, Jianmei; Zhang, Hu; Qian, Mingrong

2015-01-01

283

[PMIM]Br@TiO2 nanocomposite reinforced hollow fiber solid/liquid phase microextraction: an effective extraction technique for measurement of benzodiazepines in hair, urine and wastewater samples combined with high-performance liquid chromatography.  

PubMed

A new design of hollow fiber solid-liquid phase microextraction (HF-SLPME) was developed for the determination of benzodiazepines (BZPs) in hair, urine and wastewater. The membrane extraction with 1-pentyl-3-methylimidazolium bromide coated titanium dioxide ([PMIM]Br@TiO2) sorbent used in this research is a two-phase supported membrane extraction consisting of an aqueous (donor phase), and n-octanol/nano [PMIM]Br@TiO2 (acceptor phase) system operated in direct immersion sampling mode. The 1-pentyl-3-methylimidazolium bromide (ionic liquid) coated nano TiO2 dispersed in the organic solvent (n-octanol) is held into a porous membrane supported by capillary forces and sonification. It is in contact with the feed phase, which is the aqueous sample. The experimental setup is very simple and highly affordable. The hollow fiber is disposable, so single use of the fiber reduces the risk of cross-contamination and carry-over problems. The proposed method allows the very effective and enriched recuperation of BZPs into one single extract. In order to obtain high extraction efficiency of the analytes using this novel sorbent, the main parameters were optimized. Under the optimized extraction conditions, the method showed good linearity (0.05-6000ngmL(-1)), low limits of detection (0.08-0.5ngmL(-1)) and good enrichment (533-1190). PMID:25589255

Es'haghi, Zarrin; Nezhadali, Azizollah; Bahar, Shahriyar; Bohlooli, Shahab; Banaei, Alireza

2015-02-01

284

Micro-focused ultrasonic solid-liquid extraction (muFUSLE) combined with HPLC and fluorescence detection for PAHs determination in sediments: optimization and linking with the analytical minimalism concept.  

PubMed

Analytical minimalism is a concept that deals with the optimization of all stages of an analytical procedure so that it becomes less time, cost, sample, reagent and energy consuming. The guide-lines provided in the USEPA extraction method 3550B recommend the use of focused ultrasound (FU), i.e., probe sonication, for the solid-liquid extraction of Polycyclic Aromatic Hydrocarbons, PAHs, but ignore the principle of analytical minimalism. The problems related with the dead sonication zones, often present when high volumes are sonicated with probe, are also not addressed. In this work, we demonstrate that successful extraction and quantification of PAHs from sediments can be done with low sample mass (0.125g), low reagent volume (4ml), short sonication time (3min) and low sonication amplitude (40%). Two variables are here particularly taken into account for total extraction: (i) the design of the extraction vessel and (ii) the solvent used to carry out the extraction. Results showed PAHs recoveries (EPA priority list) ranged between 77 and 101%, accounting for more than 95% for most of the PAHs here studied, as compared with the values obtained after soxhlet extraction. Taking into account the results reported in this work we recommend a revision of the EPA guidelines for PAHs extraction from solid matrices with focused ultrasound, so that these match the analytical minimalism concept. PMID:18970118

Capelo, J L; Galesio, M M; Felisberto, G M; Vaz, C; Pessoa, J Costa

2005-06-15

285

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, Cédric; Crevecoeur, Isabelle; Bayle, Priscilla; Balzeau, Antoine; Bismuth, Thierry; Bourguignon, Laurence; Delfour, Géraldine; Faivre, Jean-Philippe; Lacrampe-Cuyaubère, François; Tavormina, Carlotta; Todisco, Dominique; Turq, Alain; Maureille, Bruno

2014-01-01

286

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, Cédric; Crevecoeur, Isabelle; Bayle, Priscilla; Balzeau, Antoine; Bismuth, Thierry; Bourguignon, Laurence; Delfour, Géraldine; Faivre, Jean-Philippe; Lacrampe-Cuyaubère, François; Tavormina, Carlotta; Todisco, Dominique; Turq, Alain; Maureille, Bruno

2014-01-01

287

Saint-Louis-Eisenthr (Sainte-Marie-aux-Mines, France de l'Est) : sans doute la plus belle mine  

E-print Network

Saint-Louis-Eisenthür (Sainte-Marie-aux-Mines, France de l'Est) : sans doute la plus belle mine d Sainte-Marie-aux-Mines (Alsace, France), Saint-Louis-Eisenthür, opened to the Public since 1988 : perhaps the finest renaissance Silvermine in Europe The mine Saint-Louis-Eisenthür is located in the Pb

Paris-Sud XI, Université de

288

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

289

Subcellular Trafficking of the Arabidopsis Auxin Influx Carrier AUX1 Uses a Novel Pathway Distinct from PIN1[W  

PubMed Central

The directional flow of the plant hormone auxin mediates multiple developmental processes, including patterning and tropisms. Apical and basal plasma membrane localization of AUXIN-RESISTANT1 (AUX1) and PIN-FORMED1 (PIN1) auxin transport components underpins the directionality of intercellular auxin flow in Arabidopsis thaliana roots. Here, we examined the mechanism of polar trafficking of AUX1. Real-time live cell analysis along with subcellular markers revealed that AUX1 resides at the apical plasma membrane of protophloem cells and at highly dynamic subpopulations of Golgi apparatus and endosomes in all cell types. Plasma membrane and intracellular pools of AUX1 are interconnected by actin-dependent constitutive trafficking, which is not sensitive to the vesicle trafficking inhibitor brefeldin A. AUX1 subcellular dynamics are not influenced by the auxin influx inhibitor NOA but are blocked by the auxin efflux inhibitors TIBA and PBA. Furthermore, auxin transport inhibitors and interference with the sterol composition of membranes disrupt polar AUX1 distribution at the plasma membrane. Compared with PIN1 trafficking, AUX1 dynamics display different sensitivities to trafficking inhibitors and are independent of the endosomal trafficking regulator ARF GEF GNOM. Hence, AUX1 uses a novel trafficking pathway in plants that is distinct from PIN trafficking, providing an additional mechanism for the fine regulation of auxin transport. PMID:17114355

Kleine-Vehn, Jürgen; Dhonukshe, Pankaj; Swarup, Ranjan; Bennett, Malcolm; Friml, Ji?í

2006-01-01

290

ETUDE DE LA COURBE DE BRAGG RELATIVE AUX RAYONS DU RADIUM C' par Mlle IRNE CURIE et M. FRANOIS BEHOUNEK  

E-print Network

ETUDE DE LA COURBE DE BRAGG RELATIVE AUX RAYONS DU RADIUM C' par Mlle IRÈNE CURIE et M. FRANÇOIS BEHOUNEK Sommaire. 2014 On a construit la courbe de Bragg relative aux rayons du RaC' dans l'air avec un'ionisation le long d'un faisceau de rayons x canalisés, dite « courbe de Bragg », a été étudiée par un grand

Boyer, Edmond

291

Aux\\/IAA Proteins Are Phosphorylated by Phytochrome in Vitro1  

Microsoft Academic Search

Auxin\\/indole-3-acetic acid (Aux\\/IAA) genes encode short-lived transcription factors that are induced as a primary response to the plant growth hormone IAA or auxin. Gain-of-function mutations in Arabidopsis genes, SHY2\\/IAA3, AXR3\\/IAA17, and AXR2\\/IAA7 cause pleiotropic phenotypes consistent with enhanced auxin responses, possibly by increasing Aux\\/IAA protein stability. Semidominant mutations shy2-1D, shy2-2, axr3-1, and axr2-1 induce ectopic light responses in dark-grown seedlings.

Adan Colon-Carmona; Donna L. Chen; Kuo-Chen Yeh; Steffen Abel

2000-01-01

292

Diagenesis and reservoir quality of the Upper Mississippian Aux Vases Sandstone, Illinois Basin  

USGS Publications Warehouse

Conventional reservoir quality data for more than 300 wells provided by the Illinois and Indiana state geological surveys were analyzed to determine the factors governing porosity and permeability in the Upper Mississippian Aux Vases Sandstone, an important hydrocarbon-producing unit in the Illinois Basin. In addition, approximately 150 samples of the Aux Vases Sandstone were collected for mineralogical and geochemical analysis to reconstruct the burial and diagenetic history and to establish the timing of diagenesis relative to the entrapment of hydrocarbons. One aspect of the study involved linking inorganic and organic diagenesis to late Paleozoic tectonism and hydrothermal fluid-flow events in the region.

Pitman, Janet K.; Henry, Mitchell E.; Leetaru, Hannes E.

1999-01-01

293

The influence of solid/liquid separation techniques on the sugar yield in two-step dilute acid hydrolysis of softwood followed by enzymatic hydrolysis  

PubMed Central

Background Two-step dilute acid hydrolysis of softwood, either as a stand-alone process or as pretreatment before enzymatic hydrolysis, is considered to result in higher sugar yields than one-step acid hydrolysis. However, this requires removal of the liquid between the two steps. In an industrial process, filtration and washing of the material between the two steps is difficult, as it should be performed at high pressure to reduce energy demand. Moreover, the application of pressure leads to more compact solids, which may affect subsequent processing steps. This study was carried out to investigate the influence of pressing the biomass, in combination with the effects of not washing the material, on the sugar yield obtained from two-step dilute acid hydrolysis, with and without subsequent enzymatic digestion of the solids. Results Washing the material between the two acid hydrolysis steps, followed by enzymatic digestion, resulted in recovery of 96% of the mannose and 81% of the glucose (% of the theoretical) in the liquid fraction, regardless of the choice of dewatering method (pressing or vacuum filtration). Not washing the solids between the two acid hydrolysis steps led to elevated acidity of the remaining solids during the second hydrolysis step, which resulted in lower yields of mannose, 85% and 74% of the theoretical, for the pressed and vacuum-filtered slurry, respectively, due to sugar degradation. However, this increase in acidity resulted in a higher glucose yield (94.2%) from pressed slurry than from filtered slurry (77.6%). Conclusion Pressing the washed material between the two acid hydrolysis steps had no significant negative effect on the sugar yields of the second acid hydrolysis step or on enzymatic hydrolysis. Not washing the material resulted in a harsher second acid hydrolysis step, which caused greater degradation of the sugars during subsequent acid hydrolysis of the solids, particularly in case of the vacuum-filtered solids. However, pressing in combination with not washing the material between the two steps enhanced the sugar yield of the enzymatic digestion step. Hence, it is suggested that the unwashed slurry be pressed to as high a dry matter content as possible between the two acid hydrolysis stages in order to achieve high final sugar yields. PMID:19291286

Monavari, Sanam; Galbe, Mats; Zacchi, Guido

2009-01-01

294

Potential food applications of high-pressure effects on ice-water transitions  

Microsoft Academic Search

Pressure depresses the freezing point of water and the melting point of ice, as well as enabling various high-density forms of ice to be obtained. These effects of pressure on the solid-liquid phase diagram of water have several potential applications in food technology, including pressure-assisted freezing, pressure-assisted thawing and non-frozen storage at low temperature (under pressure). Studies that have been

M. T. Kalichevsky; D. Knorr; P. J. Lillford

1995-01-01

295

Prospects for laser-induced breakdown spectroscopy for biomedical applications: a review  

Microsoft Academic Search

We review the different spectroscopic techniques including the most recent laser-induced breakdown spectroscopy (LIBS) for\\u000a the characterization of materials in any phase (solid, liquid or gas) including biological materials. A brief history of the\\u000a laser and its application in bioscience is presented. The development of LIBS, its working principle and its instrumentation\\u000a (different parts of the experimental set up) are

Vivek Kumar Singh; Awadhesh Kumar Rai

2011-01-01

296

CHANGEMENT ORGANISATIONNEL ET IMPLEMENTATION DES TIC : POURQUOI FAIRE ATTENTION AUX DIMENSIONS ECONOMIQUES DE LA  

E-print Network

1 CHANGEMENT ORGANISATIONNEL ET IMPLEMENTATION DES TIC : POURQUOI FAIRE ATTENTION AUX DIMENSIONS réinterprétation d'études de cas traitant du couplage entre implémentation des ERP et changements organisationnels changements organisationnels, et faisons appel pour cela à des outils de l'économie cognitive, jamais

Paris-Sud XI, Université de

297

Modelisation des Co-Expositions aux Pesticides : une Approche Bayesienne Nonparametrique  

E-print Network

Modelisation des Co-Expositions aux Pesticides : une Approche Bay´esienne Nonparam´etrique Am analysis framework. The goal is to determine mixture of pesticides residues which are simultaneously of pesticides is assessed from the available consumption data and contamination analyses. We propose to model

Paris-Sud XI, Université de

298

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 majoritaire. The ethnologist and racisms : the example of gipsies Victims of exclusion for centuries, gipsy française, 1988/2 (Ethnologie et racismes, ss la dir. Jacques Gutwirth et Jean-Claude Schmitt), pp. 173

Paris-Sud XI, Université de

299

L'adaptation des pratiques de communication orale aux missions des contrleurs de gestion  

E-print Network

1 L'adaptation des pratiques de communication orale aux missions des contrôleurs de gestion logique du contrôle de gestion, plus la pratique de techniques spécifiques de communication orale devrait of reality. This research aims at precising the required oral communication competencies through the study

Paris-Sud XI, Université de

300

Des lois de l'induction aux thormes de Thvenin et de Norton Maria Timofeeva1  

E-print Network

Des lois de l'induction aux théorèmes de Thévenin et de Norton Maria Timofeeva1 , Gilles Allègre2 circuit permettent au final d'obtenir les schémas équivalents de Thévenin et de Norton de la spire sous. Mots clés : loi de Lenz, loi de l'auto-induction, théorème de Thévenin, théorème de Norton. 1

Paris-Sud XI, Université de

301

Rseaux migratoires et structures de pouvoir : la Church of Pentecost du Ghana face aux  

E-print Network

4 Réseaux migratoires et structures de pouvoir : la Church of Pentecost du Ghana face aux communautés francophones Sandra FANCELLO L'Église de Pentecôte, originaire du Ghana et aujourd'hui implantée le Togo ont progressivement adopté la langue française comme langue liturgique, au Ghana, le débat

Paris-Sud XI, Université de

302

Diet preferences of herbivores at pasture Laboratoire adaptation des herbivores aux milieux, Inra, Theix,  

E-print Network

Review Diet preferences of herbivores at pasture B Dumont Laboratoire adaptation des herbivores aux selection / foraging abilities / herbivores Résumé - Préférences alimentaires des herbivores au pâturage. L alimentaires des herbivores devrait aider à mieux comprendre les choix que ceux-ci réalisent dans la situation

Paris-Sud XI, Université de

303

Cloning and expression analysis of novel Aux/IAA family genes in Gossypium hirsutum  

Technology Transfer Automated Retrieval System (TEKTRAN)

Members of the auxin/indole-3-acetic acid (Aux/IAA) gene family encode proteins to mediate the responses of auxin gene expression and to regulate various aspects of plant morphological development. In this paper, we report the identification of nine cDNAs that contain complete open reading frame (OR...

304

Rencontres halieutiques -Rsum Session 1 -La pche et l'aquaculture face aux enjeux  

E-print Network

Rencontres halieutiques - Résumé Session 1 - La pêche et l'aquaculture face aux enjeux du écosystèmes (ESE), AGROCAMPUS OUEST Pêche et aquaculture : les enjeux environnementaux Le secteur des pêches et de l'aquaculture est aujourd'hui un secteur en pleine mutation. L'enjeu est de placer ces

Paris-Sud XI, Université de

305

Distribution et extension de la rsistance chloroplastique aux triazines chez les adventices annuelles en France  

E-print Network

Mauvaise herbe, grande dispersion sont Amaranthus retrojlexus L., Chenopodium album L. et Solanum nigrum L Chenopodium album L., l'existence d'individus dont les chloroplastes sont insensibles aux triazines. Ces. The 3 most widen distributed species are Amaranthus retroflexus L.,Triazine resistance, Chenopodium

Paris-Sud XI, Université de

306

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 " touristes " avant la lettre [...] mais aussi des savants : naturalistes, ingénieurs, médecins, géologues : LA PRESSE DE GRANDE DIFFUSION ET LES SOCI�T�S SAVANTES La presse de grande diffusion et les revues

Paris-Sud XI, Université de

307

In Situ Adsorption Studies at the Solid/Liquid Interface:Characterization of Biological Surfaces and Interfaces Using SumFrequency Generation Vibrational Spectroscopy, Atomic Force Microscopy,and Quartz Crystal Microbalance  

SciTech Connect

Sum frequency generation (SFG) vibrational spectroscopy, atomic force microscopy (AFM), and quartz crystal microbalance (QCM) have been used to study the molecular surface structure, surface topography and mechanical properties, and quantitative adsorbed amount of biological molecules at the solid-liquid interface. The molecular-level behavior of designed peptides adsorbed on hydrophobic polystyrene and hydrophilic silica substrates has been examined as a model of protein adsorption on polymeric biomaterial surfaces. Proteins are such large and complex molecules that it is difficult to identify the features in their structure that lead to adsorption and interaction with solid surfaces. Designed peptides which possess secondary structure provide simple model systems for understanding protein adsorption. Depending on the amino acid sequence of a peptide, different secondary structures ({alpha}-helix and {beta}-sheet) can be induced at apolar (air/liquid or air/solid) interfaces. Having a well-defined secondary structure allows experiments to be carried out under controlled conditions, where it is possible to investigate the affects of peptide amino acid sequence and chain length, concentration, buffering effects, etc. on adsorbed peptide structure. The experiments presented in this dissertation demonstrate that SFG vibrational spectroscopy can be used to directly probe the interaction of adsorbing biomolecules with a surface or interface. The use of well designed model systems aided in isolation of the SFG signal of the adsorbing species, and showed that surface functional groups of the substrate are sensitive to surface adsorbates. The complementary techniques of AFM and QCM allowed for deconvolution of the effects of surface topography and coverage from the observed SFG spectra. Initial studies of biologically relevant surfaces are also presented: SFG spectroscopy was used to study the surface composition of common soil bacteria for use in bioremediation of nuclear waste.

Phillips, D.C.

2006-05-16

308

Determination of bisphenol-type endocrine disrupting compounds in food-contact recycled-paper materials by focused ultrasonic solid-liquid extraction and ultra performance liquid chromatography-high resolution mass spectrometry.  

PubMed

Focused ultrasonic solid-liquid extraction (FUSLE) and reverse-phase ultra performance liquid chromatography (UPLC) coupled to a quadrupole-time of flight mass spectrometer (Q-TOF-MS) was applied to the determination of bisphenol-type endocrine disrupting compounds (EDCs) in food-contact recycled-paper materials. Recycled paper is a potential source of EDCs. Bisphenol A (BPA), bisphenol F (BPF) and their derivatives bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) are used for the production of epoxy resins employed in the formulation of printing inks. The FUSLE of bisphenol-type EDCs from packaging is reported for the first time. First, different extraction solvents were studied and methanol was selected. Then, the main FUSLE factors affecting the extraction efficiency (solvent volume, extraction time and ultrasonic irradiation power) were studied by means of a central composite design. The FUSLE conditions selected for further experiments were 20 ml of methanol at ultrasonic amplitude of 100% for 5s. Finally, the number of extraction cycles necessary for complete extraction was established in two. The analysis of the FUSLE extracts was carried out by UPLC-Q-TOF-MS with electrospray ionization and the determination of the four analytes took place in only 4 min. The FUSLE and UPLC-ESI-QTOF-MS method was validated and applied to the analysis of different food-contact recycled-paper-based materials and packaging. The proposed method provided recoveries from 72% to 97%, repeatability and intermediate precision under 9% and 14%, respectively, and detection limits of 0.33, 0.16, 0.65 and 0.40 ?g/g for BPA, BPF, BADGE and BFDGE, respectively. The analysis of paper and cardboard samples confirmed the presence of EDCs in these packaging. PMID:22967537

Pérez-Palacios, David; Fernández-Recio, Miguel Ángel; Moreta, Cristina; Tena, María Teresa

2012-09-15

309

ARF-Aux/IAA interactions through domain III/IV are not strictly required for auxin-responsive gene expression.  

PubMed

Auxin response factors (ARFs), together with auxin/indole acetic acid proteins (Aux/IAAs), are transcription factors that play key roles in regulating auxin-responsive transcription in plants. Current models for auxin signaling predict that auxin response is dependent on ARF-Aux/IAA interactions mediated by the related protein-protein interaction domain (i.e., referred to as the CTD) found in the ARF and Aux/IAA C-terminal regions. When auxin concentrations in a cell are low, ARF activators residing on the promoters of auxin response genes are thought to be inactive because of the association with dominant Aux/IAA repressors. When auxin concentrations are elevated, the Aux/IAA repressors are recruited to auxin receptors and degraded via the ubiquitin-proteasome pathway. Destruction of the Aux/IAA repressors allows the ARF activators to function in derepressing/activating auxin response genes. While this auxin signaling pathway is simple and attractive, it is unclear whether auxin-regulated gene expression is solely dependent on ARF-Aux/IAA interactions. Here we show that auxin can affect the expression of auxin response genes in a manner that is independent of the ARF activator CTD. PMID:23603958

Wang, Shucai; Hagen, Gretchen; Guilfoyle, Tom J

2013-06-01

310

Identification and Analyses of AUX-IAA target genes controlling multiple pathways in developing fiber cells of Gossypium hirsutum L  

PubMed Central

Technological development led to an increased interest in systems biological approaches in plants to characterize developmental mechanism and candidate genes relevant to specific tissue or cell morphology. AUX-IAA proteins are important plant-specific putative transcription factors. There are several reports on physiological response of this family in Arabidopsis but in cotton fiber the transcriptional network through which AUX-IAA regulated its target genes is still unknown. in-silico modelling of cotton fiber development specific gene expression data (108 microarrays and 22,737 genes) using Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNe) reveals 3690 putative AUX-IAA target genes of which 139 genes were known to be AUX-IAA co-regulated within Arabidopsis. Further AUX-IAA targeted gene regulatory network (GRN) had substantial impact on the transcriptional dynamics of cotton fiber, as showed by, altered TF networks, and Gene Ontology (GO) biological processes and metabolic pathway associated with its target genes. Analysis of the AUX-IAA-correlated gene network reveals multiple functions for AUX-IAA target genes such as unidimensional cell growth, cellular nitrogen compound metabolic process, nucleosome organization, DNA-protein complex and process related to cell wall. These candidate networks/pathways have a variety of profound impacts on such cellular functions as stress response, cell proliferation, and cell differentiation. While these functions are fairly broad, their underlying TF networks may provide a global view of AUX-IAA regulated gene expression and a GRN that guides future studies in understanding role of AUX-IAA box protein and its targets regulating fiber development. PMID:24497725

Nigam, Deepti; Sawant, Samir V

2013-01-01

311

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,

312

Solid liquid phase changes with different densities  

E-print Network

In this paper we present a new thermodynamically consistent phase transition model describing the evolution of a liquid substance, e.g., water, in a rigid container $\\Omega$ when we freeze the container. Since the density $\\varrho_{2}$ of ice with volume fraction $\\beta_{2}$, is lower than the density $\\varrho_{1}$ of water with volume fraction $\\beta_{1}$, experiments - for instance the freezing of a glass bottle filled with water - show that the water pressure increases up to the rupture of the bottle. When the container is not impermeable, freezing may produce a non-homogeneous material, for instance water ice or sorbet. Here we describe a general class of phase transition processes including this example as particular case. Moreover, we study the resulting nonlinear and singular PDE system from the analytical viewpoint recovering existence of a global (in time) weak solution and also uniqueness for some particular choices of the nonlinear functions involved.

Fremond, Michel

2008-01-01

313

Solid liquid phase changes with different densities  

E-print Network

In this paper we present a new thermodynamically consistent phase transition model describing the evolution of a liquid substance, e.g., water, in a rigid container $\\Omega$ when we freeze the container. Since the density $\\varrho_{2}$ of ice with volume fraction $\\beta_{2}$, is lower than the density $\\varrho_{1}$ of water with volume fraction $\\beta_{1}$, experiments - for instance the freezing of a glass bottle filled with water - show that the water pressure increases up to the rupture of the bottle. When the container is not impermeable, freezing may produce a non-homogeneous material, for instance water ice or sorbet. Here we describe a general class of phase transition processes including this example as particular case. Moreover, we study the resulting nonlinear and singular PDE system from the analytical viewpoint recovering existence of a global (in time) weak solution and also uniqueness for some particular choices of the nonlinear functions involved.

Michel Fremond; Elisabetta Rocca

2008-06-18

314

Structure and expression analysis of early auxin-responsive Aux\\/IAA gene family in rice ( Oryza sativa )  

Microsoft Academic Search

Auxin exerts pleiotropic effects on plant growth and development by regulating the expression of early auxin-responsive genes\\u000a of auxin\\/indoleacetic acid (Aux\\/IAA), small auxin-up RNA, and GH3 classes. These genes have been studied extensively in dicots like soybean and Arabidopsis. We had earlier characterized a cDNA of the first monocot member of Aux\\/IAA family from rice. The achievement of the large

Mukesh Jain; Navneet Kaur; Rohini Garg; Jitendra K. Thakur; Akhilesh K. Tyagi; Jitendra P. Khurana

2006-01-01

315

The Tomato Aux\\/IAA Transcription Factor IAA9 Is Involved in Fruit Development and Leaf Morphogenesis  

Microsoft Academic Search

Auxin\\/indole-3-acetic acid (Aux\\/IAA) proteins are transcriptional regulators that mediate many aspects of plant responses to auxin. While functions of most Aux\\/IAAs have been defined mainly by gain-of-function mutant alleles in Arabidopsis thaliana, phenotypes associated with loss-of-function mutations have been scarce and subtle. We report here that the downregulation of IAA9, a tomato (Solanum lycopersicum) gene from a distinct subfamily of

Hua Wang; Brian Jones; Zhengguo Li; Pierre Frasse; Corinne Delalande; Farid Regad; Salma Chaabouni; Alain Latche; Jean-Claude Pech; Mondher Bouzayena; Nationale Superieure

2005-01-01

316

Simultaneous determination of a variety of endocrine disrupting compounds in carrot, lettuce and amended soil by means of focused ultrasonic solid-liquid extraction and dispersive solid-phase extraction as simplified clean-up strategy.  

PubMed

The present study is focused on the development of an analytical method based on focused ultrasonic solid-liquid extraction (FUSLE) followed by dispersive solid-phase extraction (dSPE) clean-up and liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS) optimised for the simultaneous analysis of certain endocrine disrupting compounds (EDCs), including alkylphenols (APs), bisphenol A (BPA), triclosan (TCS) and several hormones and sterols in vegetables (lettuce and carrot) and amended soil samples. Different variables affecting the chromatographic separation, the electrospray ionisation and mass spectrometric detection were optimised in order to improve the sensitivity of the separation and detection steps. Under the optimised extraction conditions (sonication of 5min at 33% of power with pulse times on of 0.8s and pulse times off of 0.2s in 10mL of n-hexane:acetone (30:70, v:v) mixture using an ice bath), different dSPE clean-up sorbents, such as Florisil, Envi-Carb, primary-secondary amine bonded silica (PSA) and C18, or combinations of them were evaluated for FUSLE extracts before LC-MS/MS. Apparent recoveries and precision in terms of relative standard deviation (RSDs %) of the method were determined at two different fortification levels (according to the matrix and the analyte) and values in the 70-130% and 2-27% ranges, respectively, were obtained for most of the target analytes and matrices. Matrix-matched calibration approach and the use of labelled standards as surrogates were needed for the properly quantification of most analytes and matrices. Method detection limits (MDLs), estimated with fortified samples, in the ranges of 0.1-100ng/g for carrot, 0.2-152ng/g for lettuce and 0.9-31ng/g for amended soil were obtained. The developed methodology was applied to the analysis of 11 EDCs in both real vegetable bought in a local market and in compost (from a local wastewater treatment plant, WWTP) amended soil samples. PMID:25746759

Mijangos, L; Bizkarguenaga, E; Prieto, A; Fernández, L A; Zuloaga, O

2015-04-10

317

Genome-wide identification, functional analysis and expression profiling of the Aux/IAA gene family in tomato.  

PubMed

Auxin is a central hormone that exerts pleiotropic effects on plant growth including the development of roots, shoots, flowers and fruit. The perception and signaling of the plant hormone auxin rely on the cooperative action of several components, among which auxin/indole-3-acetic acid (Aux/IAA) proteins play a pivotal role. In this study, we identified and comprehensively analyzed the entire Aux/IAA gene family in tomato (Solanum lycopersicum), a reference species for Solanaceae plants, and the model plant for fleshy fruit development. Functional characterization using a dedicated single cell system revealed that tomato Aux/IAA proteins function as active repressors of auxin-dependent gene transcription, with, however, different Aux/IAA members displaying varying levels of repression. Phylogenetic analysis indicated that the Aux/IAA gene family is slightly contracted in tomato compared with Arabidopsis, with a lower representation of non-canonical proteins. Sl-IAA genes display distinctive expression pattern in different tomato organs and tissues, and some of them display differential responses to auxin and ethylene, suggesting that Aux/IAAs may play a role in linking both hormone signaling pathways. The data presented here shed more light on Sl-IAA genes and provides new leads towards the elucidation of their function during plant development and in mediating hormone cross-talk. PMID:22368074

Audran-Delalande, Corinne; Bassa, Carole; Mila, Isabelle; Regad, Farid; Zouine, Mohamed; Bouzayen, Mondher

2012-04-01

318

Dodo remains from an in situ context from Mare aux Songes, Mauritius  

NASA Astrophysics Data System (ADS)

Since 2005, excavations at Mare aux Songes, Mauritius, have revealed the presence of a very rich, ˜4,200-year-old fossil bone bed including dodo ( Raphus cucullatus) bones and bone fragments. The recently excavated dodo assemblage comprises at least 17 individuals and is characterised by the presence of small and fragile skeletal elements, a dominance of leg elements and an absence of juveniles. The hydrology of the area suggests that dodos, like many other species, were probably lured to Mare aux Songes by the presence of freshwater during times of drought. The most likely scenario for the origin of the fossil deposit is that animals became trapped in the sediment in repeated miring events, which would favour the conservation of hindlimbs. Such a scenario is fully in accordance with the taphonomic characteristics of the bone assemblage.

Meijer, Hanneke J. M.; Gill, Arike; de Louw, Perry G. B.; van den Hoek Ostende, Lars W.; Hume, Julian P.; Rijsdijk, Kenneth F.

2012-03-01

319

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

SciTech Connect

Auxin/Indole-3-Acetic Acid (Aux/IAA) and Auxin Response Factor (ARF) transcription factors are key regulators of auxin responses in plants. A total of 35 Aux/IAA and 39 ARF genes were identified in the Populus genome. Comparative phylogenetic analysis revealed that the subgroups PoptrARF2, 6, 9 and 16 and PoptrIAA3, 16, 27 and 29 have differentially expanded in Populus relative to Arabidopsis. Activator ARFs were found to be two fold-overrepresented in the Populus genome. PoptrIAA and PoptrARF gene families appear to have expanded due to high segmental and low tandem duplication events. Furthermore, expression studies showed that genes in the expanded PoptrIAA3 subgroup display differential expression. The gene-family analysis reported here will be useful in conducting future functional genomics studies to understand how the molecular roles of these large gene families translate into a diversity of biologically meaningful auxin effects.

Kalluri, Udaya C [ORNL; DiFazio, Stephen P [West Virginia University; Brunner, A. [Virginia Polytechnic Institute and State University (Virginia Tech); Tuskan, Gerald A [ORNL

2007-01-01

320

Optimiser le processus d'innovation grce aux traces informatiques d'usages  

E-print Network

'analyse de traces informatiques d'interaction. La méthode proposée s'inscrit en complément des méthodes ethnométhodologique. Nous souhaitons savoir s'il est envisageable de fournir aux concepteurs un tableau de bord'objectif pourrait consister à rendre ce tableau de bord des usages interactif, et à tirer profit de la plasticité

Turner, William

321

L'intervenant face aux objectifs de mission: entre tensions vécues et régulations tentées  

Microsoft Academic Search

Lorsqu’on s’intéresse aux récits de missions de conseil, on constate que les objectifs de mission qui sont proposés à l’intervenant suscitent souvent chez lui des questions délicates :faut-il poursuivre ce travail avec lequel je ne me sens pas en accord ?dans quelle voie faut-il s'engager face à une incompatibilité entre les souhaits du commanditaire et les objectifs contractualisés ?faut-il aller

Michel Verstraeten

2006-01-01

322

L’hostilité aux OGM survit-elle à des produits attractifs ?  

Microsoft Academic Search

Nous testons ici les dispositions à payer des consommateurs pour des aliments transgéniques de seconde génération, c’est-à-dire ayant des caractéristiques innovantes attractives pour le consommateur par rapport au produit conventionnel. Nous testons également les dispositions à payer de tels produits lorsqu’ils sont obtenus avec des technologies alternatives aux biotechnologies transgéniques. Les résultats indiquent que la disposition à payer positive pour

Elsa Kassardjian; Stéphane Robin; Bernard Ruffieux

2008-01-01

323

L'hostilité aux OGM survit-elle à des produits attractifs ?  

Microsoft Academic Search

Nous testons ici les dispositions à payer des consommateurs pour des aliments transgéniques de seconde génération, c'est-à-dire ayant des caractéristiques innovantes attractives pour le consommateur par rapport au produit conventionnel. Nous testons également les dispositions à payer de tels produits lorsqu'ils sont obtenus avec des technologies alternatives aux biotechnologies transgéniques. Les résultats indiquent que la disposition à payer positive pour

Elsa Kassardjian; Stéphane Robin; Bernard Ruffieux

2008-01-01

324

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

325

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 Löwdin 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.; Üzengi Aktürk, O.; Tomak, M.

2014-01-01

326

DE LA CAO AUX CALCULS PAR LMENTS FINIS  

E-print Network

. . . . . . . . . . . . . . . . . . . . . . . 6 3 Applications au projet européen HIPPI 8 3.1 Passage de la CAO au CAST3M pour les cavités TRIPLE.4 Simulations mécaniques des cavités HIPPI sous pression . . . . . . . . . . . . . 13 3.4.1 Fixation d'accélérateurs internatio- naux, notamment, des projets européens comme HIPPI (High Intensity Pulsed Proton Injector

Paris-Sud XI, Université de

327

Approche aux soins en milieu communautaire à des adultes ayant une déficience développementale  

PubMed Central

Résumé Objectif Passer en revue les obligations d’ordre médical, éthique et juridique dans les soins aux adultes ayant une déficience développementale (DD) qui vivent dans la communauté. Sources des données Des recherches ont été faites dans Google et MEDLINE à l’aide des mots disabled, disability, vulnerable et community. Les lois pertinentes ont fait l’objet d’un examen. Message principal Le traitement d’un patient ayant une DD varie en fonction de facteurs comme la pathogenèse du problème actuel du patient, ses affections concomitantes, la gravité de ses déficiences et ses soutiens sociaux habituels. Bien que l’on s’entende sur les bienfaits du transfert des soins institutionnels vers des soins communautaires pour les patients ayant une DD, il s’est révélé difficile de leur dispenser des soins de grande qualité en milieu communautaire. Par ailleurs, il existe peu de travaux de recherche sur les façons d’offrir efficacement des soins aux adultes ayant une DD. En tant que professionnels des soins primaires, les médecins de famille sont souvent le premier point de contact pour les patients et sont à la fois responsables de la coordination et de la continuité des soins. Compte tenu de l’importance accrue accordée aux soins préventifs et à la détection précoce des maladies, la participation active du patient revêt aussi une grande importance. Les valeurs et les objectifs du patient sont des éléments essentiels à prendre en compte, même s’ils vont à l’encontre de la bonne santé du patient ou des propres valeurs du clinicien. Les lois s’appliquant aux personnes vulnérables varient d’une province à l’autre. Par conséquent, l’obligation de signaler des mauvais traitements suspectés pourrait différer selon que la personne vulnérable habite dans un centre de soins ou la communauté, que la personne qui soupçonne le comportement abusif est un fournisseur de services ou un professionnel de la santé ou encore que les circonstances spécifiques répondent à la définition légale de mauvais traitement ou de négligence. Conclusion Les professionnels des soins primaires doivent dispenser aux adultes ayant une DD des soins empreints de compassion qui respectent les souhaits du patient.

Osmun, W.E.; Chan, Nelson; Solomon, Robert

2015-01-01

328

Overexpression of the non-canonical Aux/IAA genes causes auxin-related aberrant phenotypes in Arabidopsis.  

PubMed

Degradation of Aux/IAA proteins which are triggered by the ubiquitin ligase complex containing the auxin F-box receptors (AFBs), is thought to be the primary reaction of auxin signaling. Upon auxin perception, AFBs bind domain II of Aux/IAA proteins that is conserved in most of the 29 family members in Arabidopsis. However, IAA20 and IAA30 lack domain II. Furthermore, IAA31, which forms a single clade with IAA20 and IAA30 in Aux/IAA protein family, has a partially conserved domain II, which contains an amino acid substitution that would cause a dominant mutation of Aux/IAA genes. It has been shown that the half-lives of these proteins are much longer than those of the canonical Aux/IAA proteins. We generated overexpression lines (OXs) of IAA20, IAA30 and IAA31 by the use of cauliflower mosaic virus 35S promoter to better understand the molecular function of atypical Aux/IAA proteins in Arabidopsis. OXs of the three genes exhibited similar auxin-related aberrant phenotypes, with IAA20 OX showing the most severe defects: Some of them showed a semi-dwarf phenotype; gravitropic growth orientation was often affected in hypocotyl and root; vasculature of cotyledons was malformed; the primary root stopped growing soon after germination because of collapse of root apical meristem. IAA 20 and IAA30 were early auxin inducible, but IAA31 was not. These results showed that the wild-type genes of the three Aux/IAAs could disturb auxin physiology when ectopically overexpressed. PMID:18298415

Sato, Atsuko; Yamamoto, Kotaro T

2008-06-01

329

THEORY OF MOTTTRANSITION : APPLICATION S TO TRANSITION METAL OXIDES  

E-print Network

125 THEORY OF MOTTTRANSITION : APPLICATION S TO TRANSITION METAL OXIDES M. CYROT Institut Laue discutons l'application de la théorie aux oxydes de métaux de transition. Abstract. 2014 We study the metal of the metal insulator transition is band splitting. For large values of the ratio U/W, the material remains

Paris-Sud XI, Université de

330

What Makes each Aux/IAA Gene Unique in its Gene Family, Expression Pattern or Properties of the Gene Product?  

PubMed

In the auxin signal transduction, two protein families, Aux/IAAs and auxin response factors, play a crucial role just downstream of auxin F-box receptors. Distinct and overlapping phenotypes of the dominant Aux/IAA mutants suggest some functional differentiation of the Aux/IAA genes in auxin signaling. Taking advantage of unique phenotypes of the msg2/iaa19 mutants, we carried out promoter-exchange experiments, where cDNA of the msg2, axr2/iaa7 or slr/iaa14 gene was driven by the MSG2 or AXR2 promoter. The cDNAs were translationally fused to the green fluorescent protein gene to measure levels of expressed protein. Results showed that many abnormal phenotypes of the dominant Aux/IAA mutants were governed by their promoter activity, but some were dependent on their gene products. The latter result highlights the possible importance of Aux/IAA protein level controled by auxin F-box receptors. PMID:19704610

Muto, Hideki; Watahiki, Masaaki K; Yamamoto, Kotaro T

2007-09-01

331

Backward-wave oscillator spectrometry and applications of composite structures  

NASA Astrophysics Data System (ADS)

Tunable backward-wave oscillators (BWO) covering the frequency range of 180- 370 GHz with an output power below 100 mW are used for the study of wave transmission and reflection in composite layered structures. Techniques for transparent and lossy liquid absorption and refraction measurements (blood plasma, ethanol, water solutions etc.) are presented. Besides of the solid- liquid structures which are applicable in phase shifters and attenuators, semiconductor-metal structures with p-i-n junctions are examined as high-speed modulators.

Brazis, R.; Gaidelis, V.; Namajunas, A.; Safonova, L.; Bumeliene, S.; Mironas, A.; Asadauskas, L.

1994-08-01

332

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

333

Loi constitutive chimioplastique pour le beton expose aux hautes temperatures  

NASA Astrophysics Data System (ADS)

Concrete is the most widely used construction material in the world. Even though it has been used for several centuries, its behavior to high temperature remains to be understood. In the light of recent extreme events, including accidents, and arson, special attention has been focused on the performance of concrete in the fire safety assessment of buildings and tunnels. Fire represents one of the most severe conditions encountered during the life-time of a structure. Concrete exposed to high temperature can significantly jeopardize the structural integrity and load bearing capacity of the structure. Spalling of concrete remains one of the main issues to be addressed in the case of fire in buildings and tunnels. Successful modeling of this phenomenon depends not only on the accurate prediction of the temperature distribution through structural concrete but also on its mechanical response to the heating and boundaries restrains conditions and the migration of moisture and associated pore pressures. Therefore, it is necessary to develop a reliable formulation of concrete with all required information to understand its behavior during and after exposure to elevated temperature. It is also necessary to properly assess the effects of thermal degradation in order to develop predictive tools and validate design codes. Many structural problems can be adequately worthy by an elastoplastic model. The ultimate goal of this study is the development of a new constitutive model under a chemoplastic framework. To do this, an experimental program is carried out. The purpose of this program is twofold. First, it is essential to calibrate the proposed constitutive law that will be developed, and, second, for defining an inverse a problem. Usually, uniaxial and triaxial tests, conducted with confining pressure varied between 1.3 and 24 MPa and a temperature up to 700°C, allow us to identify the constitutive law parameters. This law reproduces the reduced field strength due to degradation of exothermic origin. This experimental program puts emphasis on the fragile nature of the preheated concrete and demonstrates the non-applicability of two failure criteria often used in engineering calculation. An alternative is proposed and well-tested. Indeed, exposing the concrete to high temperature results in irreversible loss of stiffness as well as a loss of decohesion strength. These losses are, typically, expressed through semi-empirical relationships of the mechanical properties with temperature. Unfortunately, these relationships are inadequate because the direct impact of this degradation, on the macroscopic scale, can result in a dependency relationship between the elastic properties and the hydrates mass. Therefore, unlike traditional methods using conventional elasto-plastic models and adjusting certain parameters with local temperature, the proposed constitutive law that incorporates a function of dehydration similar to the softening index in chemo-plastics gives good results. An Etse and Willam similar criterion is used and modified for the occasion. Hardening and softening mechanisms are then needed to expand and contract the loading surface for defining the strength of the concrete on a wide range of dehydration processes. The direction and magnitude of a permanent deformation, core of the inelastic domain, are defined through the development of non-associated chemoplastic potential and new curve of ductility. The influence of hydrostatic pressure (dilatancy) and dehydration on the concrete behavior are taken into account in our model. The model is implemented in the Matlab(c) code. Strains and stresses generated in the concrete are now accurately predicted. To illustrate the capabilities of the developed model to predict the complex behavior of concrete exposed to high temperature, simulations are performed through numerical loading paths scenarios. The model is able to accurately reproduce all the experimental data.

Hammoud, Rabah

334

Genome-Wide Identification and Expression Profiling Analysis of the Aux/IAA Gene Family in Medicago truncatula during the Early Phase of Sinorhizobium meliloti Infection  

PubMed Central

Background Auxin/indoleacetic acid (Aux/IAA) genes, coding a family of short-lived nuclear proteins, play key roles in wide variety of plant developmental processes, including root system regulation and responses to environmental stimulus. However, how they function in auxin signaling pathway and symbiosis with rhizobial in Medicago truncatula are largely unknown. The present study aims at gaining deeper insight on distinctive expression and function features of Aux/IAA family genes in Medicago truncatula during nodule formation. Principal Findings Using the latest updated draft of the full Medicago truncatula genome, a comprehensive identification and analysis of IAA genes were performed. The data indicated that MtIAA family genes are distributed in all the M. truncatula chromosomes except chromosome 6. Most of MtIAA genes are responsive to exogenous auxin and express in tissues-specific manner. To understand the biological functions of MtIAA genes involved in nodule formation, quantitative real-time polymerase chain reaction (qRT-PCR) was used to test the expression profiling of MtIAA genes during the early phase of Sinorhizobium meliloti (S. meliloti) infection. The expression patterns of most MtIAA genes were down-regulated in roots and up-regulated in shoots by S. meliloti infection. The differences in expression responses between roots and shoots caused by S. meliloti infection were alleviated by 1-NOA application. Conclusion The genome-wide identification, evolution and expression pattern analysis of MtIAA genes were performed in this study. The data helps us to understand the roles of MtIAA-mediated auxin signaling in nodule formation during the early phase of S. meliloti infection. PMID:25226164

Zhang, Lei; Sun, Tao; Xu, Luqin; Tie, Shuanggui; Wang, Huizhong

2014-01-01

335

Diversity of stability, localization, interaction and control of downstream gene activity in the Maize Aux/IAA protein family.  

PubMed

AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins are central regulators of auxin signal transduction. They control many aspects of plant development, share a conserved domain structure and are localized in the nucleus. In the present study, five maize Aux/IAA proteins (ZmIAA2, ZmIAA11, ZmIAA15, ZmIAA20 and ZmIAA33) representing the evolutionary, phylogenetic and expression diversity of this gene family were characterized. Subcellular localization studies revealed that ZmIAA2, ZmIAA11 and ZmIAA15 are confined to the nucleus while ZmIAA20 and ZmIAA33 are localized in both the nucleus and the cytoplasm. Introduction of specific point mutations in the degron sequence (VGWPPV) of domain II by substituting the first proline by serine or the second proline by leucine stabilized the Aux/IAA proteins. While protein half-life times between ?11 min (ZmIAA2) to ?120 min (ZmIAA15) were observed in wild-type proteins, the mutated forms of all five proteins were almost as stable as GFP control proteins. Moreover, all five maize Aux/IAA proteins repressed downstream gene expression in luciferase assays to different degrees. In addition, bimolecular fluorescence complementation (BiFC) analyses demonstrated interaction of all five Aux/IAA proteins with RUM1 (ROOTLESS WITH UNDETECTABLE MERISTEM 1, ZmIAA10) while only ZmIAA15 and ZmIAA33 interacted with the RUM1 paralog RUL1 (RUM-LIKE 1, ZmIAA29). Moreover, ZmIAA11, ZmIAA15 ZmIAA33 displayed homotypic interaction. Hence, despite their conserved domain structure, maize Aux/IAA proteins display a significant variability in their molecular characteristics which is likely associated with the wide spectrum of their developmental functions. PMID:25203637

Ludwig, Yvonne; Berendzen, Kenneth W; Xu, Changzheng; Piepho, Hans-Peter; Hochholdinger, Frank

2014-01-01

336

Application du data mining à la segmentation du marché des meubles aux États-Unis  

Microsoft Academic Search

Determining the potential markets is a successful key for the development of any company in changing and globalization economy contexts. Several data analysis techniques are applied for segmenting a market, especially based on the typical social- economic factors in different geographical areas, and then crossed with historical sales data. In this article, we will apply clustering techniques to identify groups

CANADEL FURNITURE

2009-01-01

337

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

338

Auxin-induced, SCF(TIR1)-mediated poly-ubiquitination marks AUX/IAA proteins for degradation.  

PubMed

The plant hormone auxin (indole-3-acetic acid or IAA) regulates plant development by inducing rapid cellular responses and changes in gene expression. Auxin promotes the degradation of Aux/IAA transcriptional repressors, thereby allowing auxin response factors (ARFs) to activate the transcription of auxin-responsive genes. Auxin enhances the binding of Aux/IAA proteins to the receptor TIR1, which is an F-box protein that is part of the E3 ubiquitin ligase complex SCF(TIR1). Binding of Aux/IAA proteins leads to degradation via the 26S proteasome, but evidence for SCF(TIR1)-mediated poly-ubiquitination of Aux/IAA proteins is lacking. Here we used an Arabidopsis cell suspension-based protoplast system to find evidence for SCF(TIR1)-mediated ubiquitination of the Aux/IAA proteins SHY2/IAA3 and BDL/IAA12. Each of these proteins showed a distinct abundance and repressor activity when expressed in this cell system. Moreover, the amount of endogenous TIR1 protein appeared to be rate-limiting for a proper auxin response measured by the co-transfected DR5::GUS reporter construct. Co-transfection with 35S::TIR1 led to auxin-dependent degradation, and excess of 35S::TIR1 even led to degradation of Aux/IAAs in the absence of auxin treatment. Expression of the mutant tir1-1 protein or the related F-box protein COI1, which is involved in jasmonate signaling, had no effect on Aux/IAA degradation. Our results show that SHY2/IAA3 and BDL/IAA12 are poly-ubiquitinated and degraded in response to increased auxin or TIR1 levels. In conclusion, our data provide experimental support for the model that SCF(TIR1)-dependent poly-ubiquitination of Aux/IAA proteins marks these proteins for degradation by the 26S proteasome, leading to activation of auxin-responsive gene expression. PMID:19309453

Maraschin, Felipe dos Santos; Memelink, Johan; Offringa, Remko

2009-07-01

339

Morphological variations in AuxSiy nanostructures under variable pressure and annealing conditions  

NASA Astrophysics Data System (ADS)

Well-ordered, substrate symmetry-driven, AuxSiy structures of average size ~25 nm were formed under ultra-high vacuum (UHV) conditions using molecular beam epitaxy method. Post-annealing was done at 500 °C in three different vacuum conditions: (1) low vacuum (LV) (10-2 mbar), (2) high vacuum (HV) (10-5 mbar) and (3) UHV (10-10 mbar) (MBE chamber). For both HV and LV cases, the AuxSiy nanostructures were found to have their corners rounded unlike in UHV case where the structures have sharp edges. In all the above three cases, samples were exposed to air before annealing. In situ annealing inside UHV chamber without exposing to air resulted in well-aligned rectangles with sharp corners, while sharp but irregular island structures were found for air exposed and UHV annealing system. The role of residual gases present in LV and HV annealing environment and inhibition of lateral surface diffusion due to the presence of surface oxide (through air exposure) would be discussed. Annealing at various conditions yielded variation in the coverage and correspondingly, the average area of nanostructures varied from a ~329 nm2 (as deposited) to ~2,578 nm2 (at high temperature). High-resolution transmission electron microscopy (planar and cross section) has been utilized to study the morphological variations.

Rath, A.; Dash, J. K.; Juluri, R. R.; Satyam, P. V.

2015-03-01

340

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

341

Identification de ligands des enzymes de rsistance aux aminoglycosides par RMN. NMR identification of ligands of aminoglycoside resistance enzymes.  

E-print Network

- 1 - Identification de ligands des enzymes de résistance aux aminoglycosides par RMN. NMR identification of ligands of aminoglycoside resistance enzymes. Frédérique Maurice1 , Guillaume Bégis2 , Laurent principalement la conséquence de l'action d'enzymes qui modifient chimiquement ces antibiotiques et les empêchent

Paris-Sud XI, Université de

342

Evolution des missions de CO2 lies aux mobilits quotidiennes : une stabilit en trompe l'oeil  

E-print Network

1 Evolution des émissions de CO2 liées aux mobilités quotidiennes : une stabilité en trompe l : une stabilité en trompe l'oeil », Recherche ­ Transport - Sécurité, vol. 27, n°2, pp.128-139. halshs

Paris-Sud XI, Université de

343

238 C. WOLF. -L'IRRADIATION DU LAIT L'IRRADIATION DU LAIT AUX ETATS-UNIS  

E-print Network

Depuis 1931, les laits contenant de la vitamine D font, aux Etats- Unis, l'objet d'un commerce Impor-tanb. C'est, en effet, à cette date que le premier lait liquide à vitamine D fut mis sur le marché époque. Le lait, à vitamine D le plus-c

Paris-Sud XI, Université de

344

Shoot-supplied ammonium targets the root auxin influx carrier AUX1 and inhibits lateral root emergence  

E-print Network

Shoot-supplied ammonium targets the root auxin influx carrier AUX1 and inhibits lateral root in shoots but relates to the auxin response in roots. Expression analyses of an auxin-responsive reporter, DR5:GUS, and direct assays of auxin transport demonstrated that SSA inhibits root acro- petal

Kronzucker, Herbert J.

345

Negative phototropism is seen in Arabidopsis inflorescences when auxin signaling is reduced to a minimal level by an Aux/IAA dominant mutation, axr2.  

PubMed

Inflorescences of a dominant mutant of Arabidopsis Aux/IAA7, axr2, showed negative phototropism with a similar fluence response curve to the positive phototropism of wild-type stems. Application of a synthetic auxin, NAA, and an inhibitor of polar auxin transport, NPA, increased and decreased respectively the magnitude of the phototropic response in the wild type, while in axr2 application of NAA reduced the negative phototropic response and NPA had no effect. Decapitation of the apex induced a small negative phototropism in wild-type stems, and had no effect in axr2 plants. Inflorescences of the double mutants of auxin transporters, pgp1 pgp19, showed no phototropic response, while decapitation resulted in a negative phototropic response. These results suggest that negative phototropism can occur when the level of auxin or of auxin signaling is reduced to a minimal level, and that in plant axial organs the default phototropic response to unilateral blue light may be negative. Expression of axr2 protein by an endodermis-specific promoter resulted in agravitropism of inflorescences in a similar way to that of axr2, but phototropism was normal, confirming that the endodermis does not play a critical role in phototropism. PMID:25738325

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

2015-03-01

346

Numerical Simulation of Liquid-Solid, Solid-Liquid Phase Change Using Finite Element Method in h,p,k Framework with Space-Time Variationally Consistent Integral Forms  

E-print Network

specific heat, thermal conductivity, and latent heat of fusion are a function of temperature. The width of the interface region can be as small or as large as desired in specific applications. The mathematical models presented in the thesis assume...

Truex, Michael

2010-07-21

347

Isolation of PsPIN2 and PsAUX1 from etiolated pea epicotyls and their expression on a three-dimensional clinostat  

NASA Astrophysics Data System (ADS)

We isolated novel cDNAs containing the complete open reading frames of a putative auxin influx carrier, PsAUX1, and a putative auxin efflux carrier, PsPIN2, from etiolated pea epicotyls. High levels of homology were found on nucleotide and deduced amino acid sequences among PsPIN2, PsPIN1 (Accession No. AY222857) and AtPINs. Phylogenetic analyses based on deduced amino acid sequences revealed that PsPIN2 belonged to a subclade including AtPIN3, AtPIN4 and AtPIN7, while PsPIN1 belonged to the same clade as AtPIN1. The results were similar for PsAUX1 and AtAUX1, where PsAUX1 belongs to the same subclade as AtAUX1 and CS-AUX1. Expression of PsPIN1, PsPIN2 and PsAUX1 in pea epicotyl segments was promoted upon incubation of the segments with auxin (indole-3-acetic acid). In 3.5-d-old etiolated pea seedlings, relatively high expression of PsPIN1 and PsAUX1 was observed in the hook region, growing epicotyls and root tips as compared with those in mature regions of epicotyls and roots. Expression of PsPIN2 in roots was less than that in shoots. Simulated microgravity conditions on a three-dimensional clinostat remarkably increased gene expression of PsPIN1 and PsAUX1 in the hook and the internodes of pea epicotyls, but the increase in PsPIN2 was less. In contrast, polar auxin transport of pea epicotyls was substantially suppressed under simulated microgravity conditions on a 3D clinostat, similar to data from a space experiment on STS-95. These results suggest that PsPINs and PsAUX1 are auxin-inducible genes, and that the expression of PsPINs and PsAUX1 genes is sensitive to gravistimulation.

Hoshino, Tomoki; Hitotsubashi, Reiko; Miyamoto, Kensuke; Tanimoto, Eiichi; Ueda, Junichi

348

Étude de l’activité virucide in vitro des Gouttes aux Essences® sur le virus para-influenzae de type 3  

Microsoft Academic Search

Résumé  Le traitement par les huiles essentielles des infections respiratoires limite le recours systématique aux antibiotiques (Phytothérapie\\u000a 6 (2004) 175–9). Plusieurs virus sont responsables de ces infections virales respiratoires: virus influenza, virus respiratoire\\u000a syncytial, virus para-influenzae, adénovirus, rhinovirus... Cette étude a consisté à mettre en évidence l’activité virucide\\u000a in vitro du produit Gouttes aux Essences®, complexe de cinq huiles essentielles vis-à-vis

L. Haddioui; B. Fabre; P. Bruel

2009-01-01

349

CONTRIBUTION A L'TUDE DU DURCISSEMENT DU NIOBIUM ET DE CERTAINS DE SES ALLIAGES LIS AUX INTERSTITIELS,  

E-print Network

387 CONTRIBUTION A L'�TUDE DU DURCISSEMENT DU NIOBIUM ET DE CERTAINS DE SES ALLIAGES LI�S AUX traction effectués sous vide entre 20 et 1 200 °C sur divers alliages de Niobium ont permis de distinguer. Abstract. 2014 Tensile tests were run on different Niobium alloys from 20 to 1 200 °C in high vacuum

Paris-Sud XI, Université de

350

AXR2 Encodes a Member of the Aux/IAA Protein Family1 Punita Nagpal, Loni M. Walker2  

E-print Network

AXR2 Encodes a Member of the Aux/IAA Protein Family1 Punita Nagpal, Loni M. Walker2 , Jeff C. Young, and find that it is the same as IAA7, a member of the IAA (indole-3-acetic acid) family of auxin-inducible genes. The axr2-1 mutation changes a single amino acid in conserved domain II of AXR2/IAA7. We isolated

Estelle, Mark

351

Projet de Note aux Comptes Rendus (17 ao^ut 2012) A Cramer-Rao inequality for non differentiable  

E-print Network

Projet de Note aux Comptes Rendus (17 ao^ut 2012) A Cram´er-Rao inequality for non differentiable of the bound is related to the original Cram´er-Rao bound, although it does not require the differentiability of the model. Moreover, we show our efficiency bound to be always greater than the Cram´er-Rao bound in smooth

Coudière, Yves

352

Golfe Persique et mer Rouge : notes sur les routes de la cramique aux IX-XIIe sicles  

E-print Network

1 Golfe Persique et mer Rouge : notes sur les routes de la céramique aux IX-XIIe siècles Axelle : Société Française d'Etude de la Céramique Orientale, Musée Cernuschi. Le golfe Persique et la mer Rouge'Iran à partir du Golfe, ont successivement mis en place leurs propres réseaux avec la péninsule arabique

Paris-Sud XI, Université de

353

Niveau socioéconomique 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 amélioration constante depuis deux décennies de l'offre de soins en psychiatrie. De même, le taux d'alphabétisation sans cesse croissant s'accompagne d'une profonde modification des conceptions et des comportements. La présente étude visait à déterminer l?impact des déterminants socioéconomiques sur le processus du recours aux soins par les familles. Méthodes Il s'est agi d'une enquête transversale portant sur 200 familles, menée dans le service de psychiatrie du Centre Hospitalier Universitaire Yalgado Ouédraogo de Ouagadougou. Variable à expliquer: premier recours aux soins par les familles (guérisseur traditionnel ou prières religieuses vs. consultations psychiatrique ou médicale). Variable explicative: catégorie socioprofessionnelle classée en suivant la nomenclature des professions et catégories socioprofessionnelles; niveau d’études. L'analyse statistique a été effectuée à l'aide du logiciel SAS version 9.2. Le test du Khi deux a été utilisé. Résultats Il existait une association entre le choix du premier recours et la Profession et la catégorie socioprofessionnelledu « décideur » (p = 0.0006) ainsi que leniveau d’études du « décideur » (p = 0.0001). Conclusion La Profession et Catégorie Sociale et le niveau d'instruction scolaire pourraient être un marqueur important dans les politiques visant à optimiser les processus de recours aux soins des patients dans le circuit de soins. PMID:25161751

Yaogo, Ahmed; Sommer, Alain; Moulaï, Pierre; Chebili, Saïd; Abaoub-Germain, Agnès

2014-01-01

354

Synthesis and thermoelectric properties of p-type Ba8AuxSi46-x clathrate  

NASA Astrophysics Data System (ADS)

Poly-crystalline Ba8AuxSi46-x clathrates were synthesized by the arc melting method and a subsequent annealing treatment. The as-synthesized sample contained some precipitates rich in Au at the grain boundaries, and the precipitates were reduced by annealing at 1000 °C. The Au content of the clathrate phase for the as-synthesized sample, Ba7.4Au4.7Si41.3, was slightly lower than that for the stoichiometric composition, Ba8Au6Si40. In the annealed samples, the Au content of the clathrate phase increased with annealing time. These results indicated that Au can diffuse from Au-rich precipitates to the clathrate phase by annealing. The Seebeck coefficient of the as-synthesized and 1 hour annealed sample, Ba7.5Au5.7Si40.3, were -80 and +100 ?V/K at 500 °C, respectively. This suggested that the carrier type was changed by the Au content in the clathrate. In the samples annealed for longer than 1 hour, the Seebeck coefficient decreased with annealing time. This indicated that the hole carrier concentration increased in excess because of overdoping due to the diffusion of Au.

Saisho, Makoto; Bin, Liu; Nagatomo, Yuya; Nakakohara, Yusuke; Teranishi, Ryo; Munetoh, Shinji

2012-08-01

355

Application  

Cancer.gov

Application To apply, either email, fax, or mail the following information postmarked by December 31, 2008 to the address below: Curriculum Vitae (that includes complete address, street address, telephone, fax and e-mail) or resume; Two (2) letters

356

Irrepressible, truncated auxin response factors: natural roles and applications in dissecting auxin gene regulation pathways.  

PubMed

The molecularly well-characterized auxin signal transduction pathway involves two evolutionarily conserved families interacting through their C-terminal domains III and IV: the Auxin Response Factors (ARFs) and their repressors the Aux/IAAs, to control auxin-responsive genes, among them genes involved in auxin transport. ( 1) (,) ( 2) We have developed a new genetic tool to study ARF function. Using MONOPTEROS (MP)/ARF5, we have generated a truncated version of MP (MP?), ( 3) which has lost the target domains for repression by Aux/IAA proteins. Besides exploring genetic interactions between MP and Aux/IAAs, we used this construct to trace MP's role in vascular patterning, a previously characterized auxin dependent process. ( 4) (,) ( 5) Here we summarize examples of naturally occurring truncated ARFs and summarize potential applications of truncated ARFs as analytical tools. PMID:22827953

Ckurshumova, Wenzislava; Krogan, Naden T; Marcos, Danielle; Caragea, Adriana E; Berleth, Thomas

2012-08-01

357

Statut phospho-calcique en hémodialyse chronique dans l’Oriental Marocain: évaluation de l’adhésion aux recommandations K/DOQI et KDIGO  

PubMed Central

Les troubles phosphocalciques sont fréquents en hémodialyse chronique. Leurs conséquences justifient une prévention et un traitement adaptés aux recommandations des sociétés savantes. L’objectif de notre étude était de déterminer le statut phosphocalcique de nos patients hémodialysés chroniques (HDC) et l’évaluation des taux de conformité des indicateurs aux recommandations K/DOQI et KDIGO. Ainsi, nous avons réalisé une étude transversale incluant les 83 patients HDC du centre d’hémodialyse de l’hôpital Al Farabi d’Oujda. L’âge moyen de nos patients était de 49.8± 15.6 ans. Une prédominance masculine a été notée. La conformité des indicateurs du bilan phosphocalcique chez nos patients hémodialysés chroniques par rapport aux recommandations KDIGO était de l’ordre de 21.6%. Le pourcentage des patients ayant des données phosphocalciques conformes aux cibles recommandées par les K/DOQI était Les patients répondants simultanément aux quatres critères recommandés par les K/DOQI n’étaient que 8.4%. PMID:24570784

Benabdellah, Nawal; Karimi, Ilham; Bentata, Yassamine; Yacoubi, Hicham; Haddiya, Intissar

2013-01-01

358

Auxin represses stomatal development in dark-grown seedlings via Aux/IAA proteins.  

PubMed

Stomatal development is tightly regulated through internal and external factors that are integrated by a complex signalling network. Light represents an external factor that strongly promotes stomata formation. Here, we show that auxin-resistant aux/iaa mutants, e.g. axr3-1, exhibit a de-repression of stomata differentiation in dark-grown seedlings. The higher stomatal index in dark-grown axr3-1 mutants when compared with the wild type is due to increased cell division in the stomatal lineage. Excessive stomata in dark-grown seedlings were also observed in mutants defective in auxin biosynthesis or auxin perception and in seedlings treated with the polar auxin transport inhibitor NPA. Consistent with these findings, exogenous auxin repressed stomata formation in light-grown seedlings. Taken together, these results indicate that auxin is a negative regulator of stomatal development in dark-grown seedlings. Epistasis analysis revealed that axr3-1 acts genetically upstream of the bHLH transcription factors SPCH, MUTE and FAMA, as well as the YDA MAP kinase cascade, but in parallel with the repressor of photomorphogenesis COP1 and the receptor-like protein TMM. The effect of exogenous auxin required the ER family of leucine-rich repeat receptor-like kinases, suggesting that auxin acts at least in part through the ER family. Expression of axr3-1 in the stomatal lineage was insufficient to alter the stomatal index, implying that cell-cell communication is necessary to mediate the effect of auxin. In summary, our results show that auxin signalling contributes to the suppression of stomatal differentiation observed in dark-grown seedlings. PMID:25063454

Balcerowicz, Martin; Ranjan, Aashish; Rupprecht, Laura; Fiene, Gabriele; Hoecker, Ute

2014-08-01

359

Methodological Issues Surrounding the Application of Cognitive Psychology in Survey Research  

Microsoft Academic Search

Considérations méthodologiques sur l'application de la psychologie cognitive dans la recherche par questionnaire. Dans l'empressement à appliquer la psychologie cognitive et ses méthodes dans la recherche sociale par questionnaire pendant la dernière décennie, une attention insuffisante a été donnée aux principes scientifiques. Cet article fournit un cadre pour corriger ce problème en se concentrant sur des méthodes qui peuvent améliorer

Clyde Tucker

1997-01-01

360

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

361

Croissance Par Epitaxie EN Phase Vapeur aux Organo - et Caracterisation des Heterostructures Contraintes a Base de Phosphur de Indium  

Microsoft Academic Search

Trois systemes heteroepitaxiaux a base de InP:InP\\/Si, InAs\\/InP et InAsP\\/InP ont ete fabriques par epitaxie en phase vapeur aux organo-metalliques (EPVOM)conventionelle. En plus l'epitaxie par couches atomiques (ECA) a ete utilisee pour fabriquer des puits quantiques ultra-minces et des superreseaux a courte periode InAs\\/InP. L'epitaxie de InP sur le silicium pose des problemes lies a un desaccord de maille de

Chuong Anh Tran

1994-01-01

362

Genome-wide analysis of Aux/IAA gene family in Solanaceae species using tomato as a model.  

PubMed

Auxin plays key roles in a wide variety of plant activities, including embryo development, leaf formation, phototropism, fruit development and root initiation and development. Auxin/indoleacetic acid (Aux/IAA) genes, encoding short-lived nuclear proteins, are key regulators in the auxin transduction pathway. But how they work is still unknown. In order to conduct a systematic analysis of this gene family in Solanaceae species, a genome-wide search for the homologues of auxin response genes was carried out. Here, 26 and 27 non redundant AUX/IAAs were identified in tomato and potato, respectively. Using tomato as a model, a comprehensive overview of SlIAA gene family is presented, including the gene structures, phylogeny, chromosome locations, conserved motifs and cis-elements in promoter sequences. A phylogenetic tree generated from alignments of the predicted protein sequences of 31 OsIAAs, 29 AtIAAs, 31 ZmIAAs, and 26 SlIAAs revealed that these IAAs were clustered into three major groups and ten subgroups. Among them, seven subgroups were present in both monocot and dicot species, which indicated that the major functional diversification within the IAA family predated the monocot/dicot divergence. In contrast, group C and some other subgroups seemed to be species-specific. Quantitative real-time PCR (qRT-PCR) analysis showed that 19 of the 26 SlIAA genes could be detected in all tomato organs/tissues, however, seven of them were specifically expressed in some of tomato tissues. The transcript abundance of 17 SlIAA genes were increased within a few hours when the seedlings were treated with exogenous IAA. However, those of other six SlIAAs were decreased. The results of stress treatments showed that most SIIAA family genes responded to at least one of the three stress treatments, however, they exhibited diverse expression levels under different abiotic stress conditions in tomato seedlings. SlIAA20, SlIAA21 and SlIAA22 were not significantly influenced by stress treatments even though at least one stress-related cis-element was identified in their promoter regions. In conclusion, our comparative analysis provides an insight into the evolution and expression patterns in various tissues and in response to auxin or stresses of the Aux/IAA family members in tomato, which will provide a very useful reference for cloning and functional analysis of each member of AUX/IAA gene family in Solanaceae crops. PMID:22314799

Wu, Jian; Peng, Zhen; Liu, Songyu; He, Yanjun; Cheng, Lin; Kong, Fuling; Wang, Jie; Lu, Gang

2012-04-01

363

Paternité des articles et intérêts concurrents : une analyse des recommandations aux auteurs des journaux traitant de pratique pharmaceutique  

PubMed Central

RÉSUMÉ Contexte : La présence d’auteurs honorifiques et fantômes ainsi que les intérêts concurrents représentent des difficultés bien documentées, liées à la publication d’articles scientifiques. Il existe des lignes directrices encadrant la rédaction et la publication de manuscrits scientifiques, notamment celles de l’International Committee of Medical Journal Editors (ICMJE). Objectifs : L’objectif principal de cette étude descriptive et transversale visait à recenser les instructions portant sur la paternité des articles et les intérêts concurrents provenant des recommandations aux auteurs des journaux traitant de pratique pharmaceutique. L’objectif secondaire visait à déterminer des mesures correctrices pour une paternité des articles plus transparente. Méthode : La recherche a débuté par l’identification des journaux traitant de pratique pharmaceutique. La consultation des instructions aux auteurs des journaux a permis ensuite de recenser les recommandations destinées à éviter les problèmes de paternité des articles et d’intérêts concurrents. Finalement, les membres de l’équipe de recherche se sont consultés afin de définir des mesures correctrices possibles à l’intention des chercheurs. Résultats : Des 232 journaux traitant de pharmacie, 33 ont été définis comme traitant de pratique pharmaceutique. Un total de 24 (73 %) journaux mentionnaient suivre la politique de l’ICMJE, 14 (42 %) demandaient aux auteurs de remplir un formulaire de déclaration d’intérêts concurrents au moment de la soumission de l’article, 17 (52 %) présentaient une définition de la qualité d’auteur et 5 (15 %) demandaient de détailler les contributions de chaque auteur. Une grille de 40 critères a été élaborée pour définir l’attribution du statut d’auteur. Conclusion : Moins de la moitié des journaux demandait aux auteurs de transmettre un formulaire de déclaration des intérêts concurrents au moment de la soumission d’un article et seulement la moitié des journaux avait donné une définition de la qualité d’auteur. La publication scientifique de travaux sur les pratiques pharmaceutiques n’est pas à l’abri des manques de transparence liés à la publication. L’utilisation d’une grille décrivant la contribution de chaque auteur et la publication en ligne des travaux peuvent contribuer à limiter ces risques. PMID:24970938

Courbon, Ève; Tanguay, Cynthia; Lebel, Denis; Bussières, Jean-François

2014-01-01

364

COURBES D'IONISATION DANS LE KRYPTON ET LE XNON PURS RELATIVES AUX RAYONS 03B1 DU POLONIUM  

E-print Network

COURBES D'IONISATION DANS LE KRYPTON ET LE X�NON PURS RELATIVES AUX RAYONS 03B1 DU POLONIUM Par R polonium dans le krypton et le xénon purs. Les parcours trouvés sont : RKr = 3,03 ± 0,01 cm; RXe = 2,17 ± 0 sont d'environ 30 pour 100 dans le krypton et de 40 pour 100 dans le xénon. Dans l'air la perte par

Paris-Sud XI, Université de

365

Echo of the quantum phase transition of CeCu6-xAux in XPS: Breakdown of Kondo screening  

NASA Astrophysics Data System (ADS)

We present an x-ray photoemission study of the heavy fermion system CeCu6-xAux across the magnetic quantum phase transition of this compound at temperatures above the single-ion Kondo temperature TK . In dependence of the Au concentration x we observe a sudden change in the f -occupation number nf and the core-hole potential Udf at the critical concentration xc=0.1 . We interpret these findings in the framework of the single-impurity Anderson model. Our results are in excellent agreement with findings from earlier ultraviolet photoemission spectroscopy measurements and provide further information about the precursors of quantum criticality at elevated temperatures.

Klein, M.; Kroha, J.; v. Löhneysen, H.; Stockert, O.; Reinert, F.

2009-02-01

366

Librer et cologiser les sciences sociales (Foyer Jean, ISCC) Version longue de l'article publi dans Hemes n60, Edgar Morin aux risques d'une pense libre.  

E-print Network

dans Hemes n°60, Edgar Morin aux risques d'une pensée libre. Introduction : Edgar Morin est en passe d j'ai fait référence aux écrits d'Edgar Morin comme l'une des inspirations fondamentales de mon : en quoi la pensée d'Edgar Morin peut-elle être utile à un (jeune) chercheur en science sociale ? En

Paris-Sud XI, Université de

367

Application  

Microsoft Academic Search

\\u000a This chapter serves two major purposes. First of all it outlines general usage domains for the enMedia framework that has\\u000a been presented in this book. The second purpose is to demonstrate in detail the application of the enMedia framework and its\\u000a prototype implementation, SilkRoad, through a sequence of electronic negotiation scenario cases. In these cases, specific emphasis is set on

Michael Ströbel

368

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

369

Atomic Resolution Images of Solid-Liquid Interfaces  

NASA Astrophysics Data System (ADS)

A scanning tunneling microscope (STM) can provide atomic-resolution images of solids covered with a variety of liquids, including cryogenic fluids, both polar and nonpolar solvents, conductive aqueous solutions, oils, and even greases. This short overview includes images of solids covered with liquid nitrogen, liquid helium, paraffin oil, silicone oil, microscope immersion oil, silicone vacuum grease, fluorocarbon grease, glycerol, and salt water. These images show atoms, charge-density waves, grains in an evaporated metal film, and even corrosion processes as they occur in real time. The future includes not only basic research in surface science but also applied research in lithography, lubrication, catalysis, corrosion, electrochemistry, and perhaps even biology.

Giambattista, Brian; McNairy, W. W.; Slough, C. G.; Johnson, A.; Bell, L. D.; Coleman, R. V.; Schneir, J.; Sonnenfeld, R.; Drake, B.; Hansma, P. K.

1987-07-01

370

Intermetallic phase formation in thin solid-liquid diffusion couples  

NASA Astrophysics Data System (ADS)

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 µm) of intermetallic phase 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 ?-Cu6Sn6 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.

Bartels, F.; Morris, J. W.; Dalke, G.; Gust, W.

1994-08-01

371

Solid-liquid iron partitioning in Earth's deep mantle.  

PubMed

Melting processes in the deep mantle have important implications for the origin of the deep-derived plumes believed to feed hotspot volcanoes such as those in Hawaii. They also provide insight into how the mantle has evolved, geochemically and dynamically, since the formation of Earth. Melt production in the shallow mantle is quite well understood, but deeper melting near the core-mantle boundary remains controversial. Modelling the dynamic behaviour of deep, partially molten mantle requires knowledge of the density contrast between solid and melt fractions. Although both positive and negative melt buoyancies can produce major chemical segregation between different geochemical reservoirs, each type of buoyancy yields drastically different geodynamical models. Ascent or descent of liquids in a partially molten deep mantle should contribute to surface volcanism or production of a deep magma ocean, respectively. We investigated phase relations in a partially molten chondritic-type material under deep-mantle conditions. Here we show that the iron partition coefficient between aluminium-bearing (Mg,Fe)SiO(3) perovskite and liquid is between 0.45 and 0.6, so iron is not as incompatible with deep-mantle minerals as has been reported previously. Calculated solid and melt density contrasts suggest that melt generated at the core-mantle boundary should be buoyant, and hence should segregate upwards. In the framework of the magma oceans induced by large meteoritic impacts on early Earth, our results imply that the magma crystallization should push the liquids towards the surface and form a deep solid residue depleted in incompatible elements. PMID:22810700

Andrault, Denis; Petitgirard, Sylvain; Lo Nigro, Giacomo; Devidal, Jean-Luc; Veronesi, Giulia; Garbarino, Gaston; Mezouar, Mohamed

2012-07-19

372

Solid-Liquid Lithium Divertor Experiment: SLiDE  

Microsoft Academic Search

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

Michael Jaworski; David Ruzic

2006-01-01

373

Intermetallic phase formation in thin solid-liquid diffusion couples  

Microsoft Academic Search

Conducting joints with low fabrication temperatures and high thermal stability are useful in modern electronics. This paper\\u000a discusses the potential use of intermetallic phases in making such joints. Thin interconnection layers that consist entirely\\u000a of intermetallic phases have been produced by joining planar Cu substrates that are coated with thin films of Sn. Thin layers\\u000a (1-5 m) of intermetallic phase

F. Bartels; J. W. Jr. Morris; G. Dalke; W. Gust

1994-01-01

374

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

375

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

376

Adsorption of nanoparticles at the solid-liquid interface.  

PubMed

The adsorption of differently charged nanoparticles at liquid-solid interfaces was investigated by in situ X-ray reflectivity measurements. The layer formation of positively charged maghemite (?-Fe(2)O(3)) nanoparticles at the aqueous solution-SiO(2) interface was observed while negatively charged gold nanoparticles show no adsorption at this interface. Thus, the electrostatic interaction between the particles and the charged surface was determined as the driving force for the adsorption process. The data analysis shows that a logarithmic particle size distribution describes the density profile of the thin adsorbed maghemite layer. The size distribution in the nanoparticle solution determined by small angle X-ray scattering shows an average particle size which is similar to that found for the adsorbed film. The formed magehemite film exhibits a rather high stability. PMID:22386203

Brenner, Thorsten; Paulus, Michael; Schroer, Martin A; Tiemeyer, Sebastian; Sternemann, Christian; Möller, Johannes; Tolan, Metin; Degen, Patrick; Rehage, Heinz

2012-05-15

377

Les managers de proximité et les changements : quels sont les difficultés, les rôles et les comportements des Chefs de groupe face aux changements organisationnels ?  

Microsoft Academic Search

Alors que les organisations sont de plus en plus souvent confrontées à des problématiques de changements, le taux de réussite de leur mise en oeuvre reste relativement faible. De par leur positionnement particulier dans l'organisation, les managers de proximité ont une incidence forte sur la réussite ou l'échec des changements. Or, la littérature consacrée aux changements ne traite que très

Jérémy Vignal

2011-01-01

378

0.1 Contenus des cours proposes en M1 dans BIM En premi`ere annee, il existe quatre modules obligatoires (2 assures aux pre-  

E-print Network

0.1 Contenus des cours propos´es en M1 dans BIM En premi`ere ann´ee, il existe quatre modules- tidisciplinarit´e de BIM. Ces cours allient toujours de la Biologie aux concepts d'Informatique ou de Math´ecialit´e : BIM 6 ECTS Niveau : 400 Semestre : 1 Responsable : Alessandra Carbone et Martine Boccara R

Arleo, Angelo

379

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

380

Enseigner la France en gographie aux jeunes coliers (1788-2008) Teaching geography at school to teach France to the young pupils (1788-  

E-print Network

Enseigner la France en géographie aux jeunes écoliers (1788-2008) Teaching geography at school to teach France to the young pupils (1788- 2008) Summary For the last two centuries, the ways of teaching geography of France to the young French pupils from 9 to 11 years old have known many transformations

Boyer, Edmond

381

La micro-finance est-elle une solution efficace aux causes du rationnement bancaire ? Une analyse conomtrique travers les modles probit et binomial ngatif : Le cas du  

E-print Network

business) social capital (same sex, same ethnic group), informal sources of credit (itinerant bankers1 La micro-finance est-elle une solution efficace aux causes du rationnement bancaire ? Une analyse des pairs, activités similaires), le capital social (même sexe, même ethnie), les sources informelles

Paris-Sud XI, Université de

382

Segr (Gabriel). Au nom du King. Elvis, les fans et l'ethnologue. Montreuil. Aux lieux d'tre (enqutes), 2007, 139 p., 12 .  

E-print Network

1 Segré (Gabriel). ­ Au nom du King. Elvis, les fans et l'ethnologue. Montreuil. Aux lieux d'ethnologue Gabriel Segré livre un nouvel ouvrage sur le « phénomène Presley » et les groupes de fans. Sous le titre Au nom du king. Elvis, les fans et l'ethnologue, ce livre regroupe en dix-huit chapitres des notes d

Paris-Sud XI, Université de

383

Présentation d’une technique 3D d’accélération de la recherche de rayons application aux télécommunications microcellulaires  

Microsoft Academic Search

Résumé  Le développement des télécommunications avec les mobiles requiert l’implantation de nombreuses stations de base (BTS) afin\\u000a de couvrir les multiples cellules constituant un réseau. Les fréquences porteuses utilisées dans les réseaux actuels (GSM,\\u000a DCS), se situent dans la gamme des hyperfréquences. Afin d’optimiser le déploiement d’un ensemble de BTS, les opérateurs souhaitent\\u000a disposer d’outils informatiques rapides et performants permettant de

Mustapha Agunaou; Michel Stanislawiak; Phillipe Mariage; Pierre Degauque

1999-01-01

384

Developpement d'une methode des caracteristiques tridimensionnelle et application aux calculs de supercellules d'un reacteur CANDU  

NASA Astrophysics Data System (ADS)

The primary purpose of this study was to construct a new method for determining the cross section increments associated with the reactivity mechanisms in CANDU reactors. Based on the characteristics method, the module MCI is successfully developed and is ready to be integrated in the lattice code DRAGON. The module MCI utilizes non cyclic tracks in a three dimensional transport calculation. The characteristics method allows to resolve the same problems as the collision probabilities method but its main advantage relies on a substantial memory economy. The results of MCI module are similar to those of an EXCELL module in the CANDU-6 calculation scheme. The characteristics method is shown to be equivalent to the collision probability method for the finite domain. A new acceleration technique, the SCR (Self-Collision Rebalancing) technique, was developed using the equivalence of these two methods. When SCR is used with the one parameter variational acceleration method, the resolution converge faster than either of the two. The Tracks Merging Technique (TMT) is a new technique developed within this research to reduce the total number of tracks needed to cover the geometry of the problem studied. The TMT can be used on two levels: TMT-1 and TMT-2. We have observed a factor of four on the reduction of tracks when the TMT was used on the first level and a factor of forty when used on the second level. The TMT could be used without difficulty in the collision probability method. The MCI module was parallelized using the PVM (Parallel Virtual Machine) library for distributed-memory environment. One of four options can be used in the parallel calculation: SPLT, ANGL, STRD and MCRB. Each of the four options is associated with a special load balancing strategy. In the first three options, the load is measured in number of tracks, in the fourth option, the load is dispatched in units of macroband.

Wu, Guang Jun

385

Segmentation multimodale optimale par coupe de graphe multispectral : applications aux lsions de sclrose en plaques en IRM  

E-print Network

using multi-modalities MRIs. To that purpose, the algo- rithm learns the optimized parameters Optimization, Multiple sclerosis, Segmentation, Graph Cut, Multispectral gradient, MRI, multimodal imaging 1

Paris-Sud XI, Université de

386

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

387

Arabidopsis SHR and SCR transcription factors and AUX1 auxin influx carrier control the switch between adventitious rooting and xylogenesis in planta and in in vitro cultured thin cell layers  

PubMed Central

Background and Aims Adventitious roots (ARs) are essential for vegetative propagation. The Arabidopsis thaliana transcription factors SHORT ROOT (SHR) and SCARECROW (SCR) affect primary/lateral root development, but their involvement in AR formation is uncertain. LAX3 and AUX1 auxin influx carriers contribute to primary/lateral root development. LAX3 expression is regulated by SHR, and LAX3 contributes to AR tip auxin maximum. In contrast, AUX1 involvement in AR development is unknown. Xylogenesis is induced by auxin plus cytokinin as is AR formation, but the genes involved are largely unknown. Stem thin cell layers (TCLs) form ARs and undergo xylogenesis under the same auxin plus cytokinin input. The aim of this research was to investigate SHR, SCR, AUX1 and LAX3 involvement in AR formation and xylogenesis in intact hypocotyls and stem TCLs in arabidopsis. Methods Hypocotyls of scr-1, shr-1, lax3, aux1-21 and lax3/aux1-21 Arabidopsis thaliana null mutant seedlings grown with or without auxin plus cytokinin were examined histologically, as were stem TCLs cultured with auxin plus cytokinin. SCR and AUX1 expression was monitored using pSCR::GFP and AUX1::GUS lines, and LAX3 expression and auxin localization during xylogenesis were monitored by using LAX3::GUS and DR5::GUS lines. Key Results AR formation was inhibited in all mutants, except lax3. SCR was expressed in pericycle anticlinally derived AR-forming cells of intact hypocotyls, and in cell clumps forming AR meristemoids of TCLs. The apex was anomalous in shr and scr ARs. In all mutant hypocotyls, the pericycle divided periclinally to produce xylogenesis. Xylary element maturation was favoured by auxin plus cytokinin in shr and aux1-21. Xylogenesis was enhanced in TCLs, and in aux1-21 and shr in particular. AUX1 was expressed before LAX3, i.e. in the early derivatives leading to either ARs or xylogenesis. Conclusions AR formation and xylogenesis are developmental programmes that are inversely related, but they involve fine-tuning by the same proteins, namely SHR, SCR and AUX1. Pericycle activity is central for the equilibrium between xylary development and AR formation in the hypocotyl, with a role for AUX1 in switching between, and balancing of, the two developmental programmes. PMID:25617411

Della Rovere, F.; Fattorini, L.; D’Angeli, S.; Veloccia, A.; Del Duca, S.; Cai, G.; Falasca, G.; Altamura, M. M.

2015-01-01

388

Un profil d'application de LOM pour les Serious Games Iza Marfisi-Schottman*, Sbastien George*, Franck Tarpin-Bernard**  

E-print Network

81 Un profil d'application de LOM pour les Serious Games Iza Marfisi-Schottman*, Sébastien George. Les Serious Games (SG), que l'on peut traduire par « jeux éducatifs », sont des environnements nouveaux champs spécifiques aux SG. MOTS-CL�S : Learning Object Metadata, Serious Games, jeux éducatif

Paris-Sud XI, Université de

389

Phenotypes associated with down-regulation of Sl-IAA27 support functional diversity among Aux/IAA family members in tomato.  

PubMed

The phytohormone auxin is known to regulate several aspects of plant development, and Aux/IAA transcription factors play a pivotal role in auxin signaling. To extend our understanding of the multiple functions of Aux/IAAs further, the present study describes the functional characterization of Sl-IAA27, a member of the tomato Aux/IAA gene family. Sl-IAA27 displays a distinct behavior compared with most Aux/IAA genes regarding the regulation of its expression by auxin, and the Sl-IAA27-encoded protein harbors a unique motif of unknown function also present in Sl-IAA9 and remarkably conserved in monocot and dicot species. Tomato transgenic plants underexpressing the Sl-IAA27 gene revealed multiple phenotypes related to vegetative and reproductive growth. Silencing of Sl-IAA27 results in higher auxin sensitivity, altered root development and reduced Chl content in leaves. Both ovule and pollen display a dramatic loss of fertility in Sl-IAA27 down-regulated lines, and the internal anatomy of the flower and the fruit are modified, with an enlarged placenta in smaller fruits. In line with the reduced Chl content in Sl-IAA27 RNA interference (RNAi) leaves, genes involved in Chl synthesis display lower expression at the level of transcript accumulation. Even though Sl-IAA27 is closely related to Sl-IAA9 in terms of sequence homology and the encoded proteins share common structural features, the data indicate that the two genes regulate tomato fruit initiation and development in a distinct manner. PMID:22764281

Bassa, Carole; Mila, Isabelle; Bouzayen, Mondher; Audran-Delalande, Corinne

2012-09-01

390

COMMUNIQU DE PRESSE I PARIS -MARSEILLE I 25 AOUT 2014 Les glaciers tropicaux ont ragi aux coups de froid de l'Antarctique et du Groenland au  

E-print Network

+ COMMUNIQU� DE PRESSE I PARIS - MARSEILLE I 25 AOUT 2014 Les glaciers tropicaux ont réagi aux-Unis, de Colombie et du Royaume-Uni. Leur étude, menée sur 21 glaciers andins, est publiée le 24 août 2014 sur le site de la revue Nature. Comme ailleurs sur la planète, les glaciers des tropiques (situés de

van Tiggelen, Bart

391

COMMUNIQU DE PRESSE NATIONAL I PARIS I 24 AOUT 2014 Les glaciers tropicaux ont ragi aux coups de froid de l'Antarctique et du Groenland au  

E-print Network

PARIS I 24 AOUT 2014 Les glaciers tropicaux ont réagi aux coups de froid de l'Antarctique et du-Uni. Leur étude, menée sur 21 glaciers andins, est publiée le 24 août 2014 sur le site de la revue Nature. Comme ailleurs sur la planète, les glaciers des tropiques (situés de part et d'autre de l

392

Bienvenue aux quipes fminines et masculines U9, U10 (7 contre 7), U11 (9 contre 9) et U12 (11 contre 11).  

E-print Network

e édition Bienvenue aux équipes féminines et masculines U9, U10 (7 contre 7), U11 (9 contre 9) et U soccer des Carabins. Dates U9, U10 et U11 : 11 mai U12 : 12 mai Lieu CEPSUM 2100, boul. Édouard à la saison 9 #12;Tarifs U9 et U10 : 250$ par équipe / 225$ avant le 1er mars 2013 U11 et U12 : 300

Charette, André

393

L'Universit d'Ottawa s'est associe Western Union Solutions d'affaires pour offrir aux tudiants trangers un  

E-print Network

L'Université d'Ottawa s'est associée àWestern Union Solutions d'affaires pour offrir aux étudiants sera ensuite convertie en dollars canadiens. · Western Union Solutions d'affaires et l'Université d les fonds à Western Union Solutions d'affaires. �tape 4 : Attendez la confirmation du paiement · L

Petriu, Emil M.

394

Sl-IAA3, a tomato Aux/IAA at the crossroads of auxin and ethylene signalling involved in differential growth.  

PubMed

Whereas the interplay of multiple hormones is essential for most plant developmental processes, the key integrating molecular players remain largely undiscovered or uncharacterized. It is shown here that a member of the tomato auxin/indole-3-acetic acid (Aux/IAA) gene family, Sl-IAA3, intersects the auxin and ethylene signal transduction pathways. Aux/IAA genes encode short-lived transcriptional regulators central to the control of auxin responses. Their functions have been defined primarily by dominant, gain-of-function mutant alleles in Arabidopsis. The Sl-IAA3 gene encodes a nuclear-targeted protein that can repress transcription from auxin-responsive promoters. Sl-IAA3 expression is auxin and ethylene dependent, is regulated on a tight tissue-specific basis, and is associated with tissues undergoing differential growth such as in epinastic petioles and apical hook. Antisense down-regulation of Sl-IAA3 results in auxin and ethylene-related phenotypes, including altered apical dominance, lower auxin sensitivity, exaggerated apical hook curvature in the dark and reduced petiole epinasty in the light. The results provide novel insights into the roles of Aux/IAAs and position the Sl-IAA3 protein at the crossroads of auxin and ethylene signalling in tomato. PMID:19213814

Chaabouni, Salma; Jones, Brian; Delalande, Corinne; Wang, Hua; Li, Zhengguo; Mila, Isabelle; Frasse, Pierre; Latché, Alain; Pech, Jean-Claude; Bouzayen, Mondher

2009-01-01

395

The PB1 Domain in Auxin Response Factor and Aux/IAA Proteins: A Versatile Protein Interaction Module in the Auxin Response[OPEN  

PubMed Central

An integral part of auxin-regulated gene expression involves the interplay of two types of transcription factors, the DNA binding auxin response factor (ARF) activators and the interacting auxin/indole acetic acid (Aux/IAA) repressors. Insight into the mechanism of how these transcription factors interact with one another has recently been revealed from crystallographic information on ARF5 and ARF7 C-terminal domains (i.e., a protein-protein interaction domain referred to as domain III/IV that is related to domain III/IV in Aux/IAA proteins). Three-dimensional structures showed that this domain in ARF5 and ARF7 conforms to a well-known PB1 (Phox and Bem1) domain that confers protein-protein interactions with other PB1 domain proteins through electrostatic contacts. Experiments verifying the importance of charged amino acids in conferring ARF and Aux/IAA interactions have confirmed the PB1 domain structure. Some in planta experiments designed to test the validity of PB1 interactions in the auxin response have led to updated models for auxin-regulated gene expression and raised many questions that will require further investigation. In addition to the PB1 domain, a second protein interaction module that functions in ARF-ARF dimerization and facilitates DNA binding has recently been revealed from crystallography studies on the ARF1 and ARF5 DNA binding domains. PMID:25604444

2015-01-01

396

Growth of Na0.3WO3 nanorods for the field emission application  

NASA Astrophysics Data System (ADS)

Na0.3WO3 1D nanostructure forms (nanorods and nanobelts) were grown by a solid-liquid-solid mechanism from a 40 nm sputtered tungsten film deposited on a soda-lime substrate and annealed at 700 °C in a tubular furnace in N2 ambient. The morphology, structure, composition and chemical state of the prepared nanostructures were characterized by SEM, XRD, TEM, SAED and XPS measurements. The Na0.3WO3 1D nanostructures were found to have a cubic crystalline structure and grown along the [0 0 1] direction. The nanorods are a few micrometres in length and about 50 nm in diameter. The field-emission application of the prepared samples at different distances between the cathode and the anode was characterized in a UHV chamber at room temperature and a field enhancement factor of 1736 at a distance of 350 µm was found.

Azimirad, Rouhollah; Khademi, Ali; Akhavan, Omid; Moshfegh, Alireza Z.

2009-10-01

397

Developpement d'une plateforme de calcul d'equilibres chimiques complexes et adaptation aux problemes electrochimiques et d'equilibres contraints  

NASA Astrophysics Data System (ADS)

Avec l'arrivée de l'environnement comme enjeu mondial, le secteur de l'efficacité énergétique prend une place de plus en plus importante pour les entreprises autant au niveau économique que pour l'image de la compagnie. Par le fait même, le domaine des technologies de l'énergie est un créneau de recherche dont les projets en cours se multiplient. D'ailleurs, un des problèmes qui peut survenir fréquemment dans certaines entreprises est d'aller mesurer la composition des matériaux dans des conditions difficiles d'accès. C'est le cas par exemple de l'électrolyse de l'aluminium qui se réalise à des températures très élevées. Pour pallier à ce problème, il faut créer et valider des modèles mathématiques qui vont calculer la composition et les propriétés à l'équilibre du système chimique. Ainsi, l'objectif global du projet de recherche est de développer un outil de calcul d'équilibres chimiques complexes (plusieurs réactions et plusieurs phases) et l'adapter aux problèmes électrochimiques et d'équilibres contraints. Plus spécifiquement, la plateforme de calcul doit tenir compte de la variation de température due à un gain ou une perte en énergie du système. Elle doit aussi considérer la limitation de l'équilibre due à un taux de réaction et enfin, résoudre les problèmes d'équilibres électrochimiques. Pour y parvenir, les propriétés thermodynamiques telles que l'énergie libre de Gibbs, la fugacité et l'activité sont tout d'abord étudiées pour mieux comprendre les interactions moléculaires qui régissent les équilibres chimiques. Ensuite, un bilan énergétique est inséré à la plateforme de calcul, ce qui permet de calculer la température à laquelle le système est le plus stable en fonction d'une température initiale et d'une quantité d'énergie échangée. Puis, une contrainte cinétique est ajoutée au système afin de calculer les équilibres pseudo-stationnaires en évolution dans le temps. De plus, la contrainte d'un champ de potentiel électrique est considérée pour l'évaluation des équilibres électrochimiques par des techniques classiques de résolution et fera l'objet de travaux futurs via une technique d'optimisation. Enfin, les résultats obtenus sont comparés avec ceux présents dans la littérature scientifique pour valider le modèle. À terme, le modèle développé devient tin bon moyen de prédire des résultats en éliminant beaucoup de coût en recherche et développement. Les résultats ainsi obtenus sont applicables dans une grande variété de domaines tels que la chimie et l'électrochimie industrielle ainsi que la métallurgie et les matériaux. Ces applications permettraient de réduire la production de gaz à effet de serre en optimisant les procédés et en ayant une meilleure efficacité énergétique. Mots-clés : Systèmes énergétiques avancés, Équilibre thermodynamique, Équilibre contraint, Optimisation, Minimisation de l'énergie libre de Gibbs.

Neron, Alex

398

Développement d’un mécanisme de contrôle d’accès aux données  

E-print Network

The LHCb experiment delivers proton-proton collisions at a rate up to 40 Mhz. The data collected are managed by a software call the Buffer Manager. The Buffer Manager is subdivided into two groups: the client part which is itself severed : the producers are to put the data into the memory and the consumers are to collect them for analysis, and the server part in charge of organising delivered by the producer and to deliver them to the client. This software contains a bug. If a problem occurs in one of the applications there is no way to wipe it off from the memory but to do it manually. The issue of the internship was to automate the clean-up task by setting-up a communication using named pipes.

Rouvière, Nicolas; Mesnard, Emmanuel

399

Application of PTR-MS for Measuring Odorant Emissions from Soil Application of Manure Slurry  

PubMed Central

Odorous volatile organic compounds (VOC) and hydrogen sulfide (H2S) are emitted together with ammonia (NH3) from manure slurry applied as a fertilizer, but little is known about the composition and temporal variation of the emissions. In this work, a laboratory method based on dynamic flux chambers packed with soil has been used to measure emissions from untreated pig slurry and slurry treated by solid-liquid separation and ozonation. Proton-transfer-reaction mass spectrometry (PTR-MS) was used to provide time resolved data for a range of VOC, NH3 and H2S. VOC included organic sulfur compounds, carboxylic acids, phenols, indoles, alcohols, ketones and aldehydes. H2S emission was remarkably observed to take place only in the initial minutes after slurry application, which is explained by its high partitioning into the air phase. Long-term odor effects are therefore assessed to be mainly due to other volatile compounds with low odor threshold values, such as 4-methylphenol. PTR-MS signal assignment was verified by comparison to a photo-acoustic analyzer (NH3) and to thermal desorption GC/MS (VOC). Due to initial rapid changes in odorant emissions and low concentrations of odorants, PTR-MS is assessed to be a very useful method for assessing odor following field application of slurry. The effects of treatments on odorant emissions are discussed. PMID:25585103

Feilberg, Anders; Bildsoe, Pernille; Nyord, Tavs

2015-01-01

400

Application of PTR-MS for measuring odorant emissions from soil application of manure slurry.  

PubMed

Odorous volatile organic compounds (VOC) and hydrogen sulfide (H2S) are emitted together with ammonia (NH3) from manure slurry applied as a fertilizer, but little is known about the composition and temporal variation of the emissions. In this work, a laboratory method based on dynamic flux chambers packed with soil has been used to measure emissions from untreated pig slurry and slurry treated by solid-liquid separation and ozonation. Proton-transfer-reaction mass spectrometry (PTR-MS) was used to provide time resolved data for a range of VOC, NH3 and H2S. VOC included organic sulfur compounds, carboxylic acids, phenols, indoles, alcohols, ketones and aldehydes. H2S emission was remarkably observed to take place only in the initial minutes after slurry application, which is explained by its high partitioning into the air phase. Long-term odor effects are therefore assessed to be mainly due to other volatile compounds with low odor threshold values, such as 4-methylphenol. PTR-MS signal assignment was verified by comparison to a photo-acoustic analyzer (NH3) and to thermal desorption GC/MS (VOC). Due to initial rapid changes in odorant emissions and low concentrations of odorants, PTR-MS is assessed to be a very useful method for assessing odor following field application of slurry. The effects of treatments on odorant emissions are discussed. PMID:25585103

Feilberg, Anders; Bildsoe, Pernille; Nyord, Tavs

2015-01-01

401

Prediction de l'ornierage lie aux deformations permanentes des enrobes bitumineux  

NASA Astrophysics Data System (ADS)

The objective of this thesis is to develop a tool to predict the behavior of flexible pavements vis-a-vis the rutting phenomenon. Through a literature review, we have come to modify the model according to the validation of the time-temperature superposition principle. The application of this principle leads to a simplification of the methodology for characterizing asphalt mixtures by reducing the minimum number of test from 9 to 6. Work methodology centered around the ESSO model allow the development of a predictive tool, the OPECC© tool (Outil de Prédiction de l'Évolution du Comportement de la Chaussée). This tool allows the user to predict the behavior of a pavement structure vis-a-vis rutting and fatigue cracking while integrating different modules that change the mix properties depending on temperature and stress frequency, and as a function of traffic patterns and road structure. This tool, through various simulations and fine-tuned according to measured results on existing roadways, proves its potential to highlight the differences attributed to various stress and design conditions which are part of roadway dimensioning.

Meunier, Mathieu

402

Recent advances in vacuum sciences and applications  

NASA Astrophysics Data System (ADS)

Recent advances in vacuum sciences and applications are reviewed. Novel optical interferometer cavity devices enable pressure measurements with ppm accuracy. The innovative dynamic vacuum standard allows for pressure measurements with temporal resolution of 2 ms. Vacuum issues in the construction of huge ultra-high vacuum devices worldwide are reviewed. Recent advances in surface science and thin films include new phenomena observed in electron transport near solid surfaces as well as novel results on the properties of carbon nanomaterials. Precise techniques for surface and thin-film characterization have been applied in the conservation technology of cultural heritage objects and recent advances in the characterization of biointerfaces are presented. The combination of various vacuum and atmospheric-pressure techniques enables an insight into the complex phenomena of protein and other biomolecule conformations on solid surfaces. Studying these phenomena at solid-liquid interfaces is regarded as the main issue in the development of alternative techniques for drug delivery, tissue engineering and thus the development of innovative techniques for curing cancer and cardiovascular diseases. A review on recent advances in plasma medicine is presented as well as novel hypotheses on cell apoptosis upon treatment with gaseous plasma. Finally, recent advances in plasma nanoscience are illustrated with several examples and a roadmap for future activities is presented.

Mozeti?, M.; Ostrikov, K.; Ruzic, D. N.; Curreli, D.; Cvelbar, U.; Vesel, A.; Primc, G.; Leisch, M.; Jousten, K.; Malyshev, O. B.; Hendricks, J. H.; Kövér, L.; Tagliaferro, A.; Conde, O.; Silvestre, A. J.; Giapintzakis, J.; Buljan, M.; Radi?, N.; Draži?, G.; Bernstorff, S.; Biederman, H.; Kylián, O.; Hanuš, J.; Miloševi?, S.; Galtayries, A.; Dietrich, P.; Unger, W.; Lehocky, M.; Sedlarik, V.; Stana-Kleinschek, K.; Drmota-Petri?, A.; Pireaux, J. J.; Rogers, J. W.; Anderle, M.

2014-04-01

403

Comprehensive Genome-Wide Analysis of the Aux/IAA Gene Family in Eucalyptus: Evidence for the Role of EgrIAA4 in Wood Formation.  

PubMed

Auxin plays a pivotal role in various plant growth and development processes, including vascular differentiation. The modulation of auxin responsiveness through the auxin perception and signaling machinery is believed to be a major regulatory mechanism controlling cambium activity and wood formation. To gain more insights into the roles of key Aux/IAA gene regulators of the auxin response in these processes, we identified and characterized members of the Aux/IAA family in the genome of Eucalyptus grandis, a tree of worldwide economic importance. We found that the gene family in Eucalyptus is slightly smaller than that in Populus and Arabidopsis, but all phylogenetic groups are represented. High-throughput expression profiling of different organs and tissues highlighted several Aux/IAA genes expressed in vascular cambium and/or developing xylem, some showing differential expression in response to developmental (juvenile vs. mature) and/or to environmental (tension stress) cues. Based on the expression profiles, we selected a promising candidate gene, EgrIAA4, for functional characterization. We showed that EgrIAA4 protein is localized in the nucleus and functions as an auxin-responsive repressor. Overexpressing a stabilized version of EgrIAA4 in Arabidopsis dramatically impeded plant growth and fertility and induced auxin-insensitive phenotypes such as inhibition of primary root elongation, lateral root emergence and agravitropism. Interestingly, the lignified secondary walls of the interfascicular fibers appeared very late, whereas those of the xylary fibers were virtually undetectable, suggesting that EgrIAA4 may play crucial roles in fiber development and secondary cell wall deposition. PMID:25577568

Yu, Hong; Soler, Marçal; San Clemente, Hélène; Mila, Isabelle; Paiva, Jorge A P; Myburg, Alexander A; Bouzayen, Mondher; Grima-Pettenati, Jacqueline; Cassan-Wang, Hua

2015-04-01

404

Algorithme d'adaptation du filtre de Kalman aux variations soudaines de bruit  

NASA Astrophysics Data System (ADS)

This research targets the case of Kalman filtering as applied to linear time-invariant systems having unknown process noise covariance and measurement noise covariance matrices and addresses the problem represented by the incomplete a priori knowledge of these two filter initialization parameters. The goal of this research is to determine in realtime both the process covariance matrix and the noise covariance matrix in the context of adaptive Kalman filtering. The resultant filter, called evolutionary adaptive Kalman filter, is able to adapt to sudden noise variations and constitutes a hybrid solution for adaptive Kalman filtering based on metaheuristic algorithms. MATLAB/Simulink simulation using several processes and covariance matrices plus comparison with other filters was selected as validation method. The Cramer-Rae Lower Bound (CRLB) was used as performance criterion. The thesis begins with a description of the problem under consideration (the design of a Kalman filter that is able to adapt to sudden noise variations) followed by a typical application (INS-GPS integrated navigation system) and by a statistical analysis of publications related to adaptive Kalman filtering. Next, the thesis presents the current architectures of the adaptive Kalman filtering: the innovation adaptive estimator (IAE) and the multiple model adaptive estimator (MMAE). It briefly presents their formulation, their behavior, and the limit of their performances. The thesis continues with the architectural synthesis of the evolutionary adaptive Kalman filter. The steps involved in the solution of the problem under consideration is also presented: an analysis of Kalman filtering and sub-optimal filtering methods, a comparison of current adaptive Kalman and sub-optimal filtering methods, the emergence of evolutionary adaptive Kalman filter as an enrichment of sub-optimal filtering with the help of biological-inspired computational intelligence methods, and the step-by-step architectural synthesis of the evolutionary adaptive Kalman filter. Next, the thesis describes all the aspects related to MATLAB/Simulink modeling and simulation: the performance criterion represented by the Cramer-Rae Lower Bound, the step-by-step modeling of the evolutionary adaptive Kalman filter, and the simulation results that confirm the viability of this approach. The thesis ends with the conclusion and the references. The appendices (the mathematical model of a 6DoF Inertial Measurement Unit, the experimental setup, the Simulink diagrams/MATLAB programs that constitute the evolutionary adaptive Kalman filter, plus the simulation results) are regrouped in a separate document.

Canciu, Vintila

405

Imaginaire et développement des réseaux techniques. Les apports de l'histoire de l'électrification rurale en France et aux Etats-Unis  

Microsoft Academic Search

Résumé L'historiographie accumulée depuis une quinzaine d'années sur le développement des réseaux techniques conduit à redonner une place véritable à l'imaginaire, au-delà de la phase d'appropriation initiale de ces techniques. C'est ce que l'on se propose d'illustrer dans cet article à partir de l'histoire de l'électrification rurale en France et aux Etats-Unis, qui atteste d'un volontarisme fort de l'Etat en

Olivier Coutard

406

Methode des elements finis hybride appliquee aux vibrations des coques spheriques  

NASA Astrophysics Data System (ADS)

The analysis of spherical shells filled with fluid and subjected to supersonic flow has been the subject of few research. Most of these studies treat the dynamic behaviour of empty shells. Few works have investigated spherical shells filled with fluid or subjected to supersonic flutter. In this thesis, we propose to develop a model to analyse the vibratory behaviour of both empty spherical shells and partially filled with fluid. This model is also applicable to study of the dynamic stability of spherical shells subjected to supersonic flow. The model developed is a combination of finite element method, thin shell theory, potential fluid theory and aerodynamic fluid theory. Different parameters are considered here in this study. In the first part of this study, free vibration analysis of spherical shell is carried out. The structural model is based on a combination of thin shell theory and the classical finite element method. Free vibration equations using the hybrid finite element formulation are derived and solved numerically. The results are validated using numerical and theoretical data available in the literature. The analysis is accomplished for spherical shells of different geometries, boundary conditions and radius to thickness ratios. This proposed hybrid finite element method can be used efficiently for design and analysis of spherical shells employed in high speed aircraft structures. In the second part of the present study, a hybrid finite element method is applied to investigate the free vibration of spherical shell filled with fluid. The structural model is based on a combination of thin shell theory and the classical finite element method. It is assumed that the fluid is incompressible and has no free-surface effect. Fluid is considered as a velocity potential variable at each node of the shell element where its motion is expressed in terms of nodal elastic displacement at the fluid-structure interface. Numerical simulation is done and vibration frequencies for different filling ratios are obtained and compared with existing experimental and theoretical results. The dynamic behavior for different shell geometries, filling ratios and boundary conditions with different radius to thickness ratios is summarized. This proposed hybrid finite element method can be used efficiently for analyzing the dynamic behavior of aerospace structures at less computational cost than other commercial FEM software. In this study, aeroelastic analysis of a spherical shell subjected to the external supersonic airflow is carried out. The structural model is based on a combination of linear spherical shell theory and the classic finite element method. In this hybrid method, the nodal displacements are found from the exact solution of shell governing equations rather than approximated by polynomial functions. Linearized first-order potential (piston) theory with the curvature correction term is coupled with the structural model to account for pressure loading. Linear mass, stiffness and damping matrices are found using the hybrid finite element formulation. Aeroelastic equations are derived and solved numerically. The results are validated using numerical and theoretical data available in the literature. The analysis is accomplished for spherical shells of different boundary conditions, geometries, flow parameters and radius to thickness ratios. Results show that the spherical shell loses its stability through coupled-mode flutter. This proposed hybrid finite element method can be used efficiently for design and analysis of spherical shells employed in high speed aircraft structures.

Menaa, Mohamed

407

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

408

Résistance aux antituberculeux  

Microsoft Academic Search

Mycobacteria responsible for tuberculosis (M. tuberculosis, M. bovis, M. africanum) are susceptible to a very small number of antibiotics. As soon as these drugs were used in humans all gave rise to the selection of resistant mycobacteria. Study of the mechanisms of acquired resistance, with the help of the genetics of mycobacteria, led to a more accurate understanding of the

N. Veziris; E. Cambau; W. Sougakoff; J. Robert; V. Jarlier

2005-01-01

409

Contrairement aux apparences, le piano est un systme acoustique et mcanique sophistiqu dont la facture demeure ce jour trs largement empirique. Les connaissances, trs prcises, des concepteurs et fabricants  

E-print Network

Contrairement aux apparences, le piano est un système acoustique et mécanique sophistiqué dont la fabricants de pianos sont issues de siècles d'expérimentations, d'échecs, de succès... Et intriguent beaucoup fonctionnement d'un piano et de ses différents éléments, il est possible de confirmer ou non ces connaissances et

Boyer, Edmond

410

Distinguishing possible mechanisms for auxin-mediated developmental control in Arabidopsis: models with two Aux/IAA and ARF proteins, and two target gene-sets.  

PubMed

New models of gene transcriptional responses to auxin signalling in Arabidopsis are presented. This work extends a previous model of auxin signalling to include networks of gene-sets which may control developmental responses along auxin gradients. Key elements of this new study include models of signalling pathways and networks involving two Aux-IAA proteins (IAAs), auxin response factors (ARFs) and gene targets. Hypotheses for the gene network topologies which may be involved in developmental responses have been tested against experimental observations for root hair growth in particular. In studying these models, we provide a framework for the analysis of auxin signalling with multiple IAAs and ARFs, and discuss the implications of bistability in such systems. PMID:22067512

Bridge, L J; Mirams, G R; Kieffer, M L; King, J R; Kepinski, S

2012-01-01

411

Ordered BaAl4- Type Variants in the BaAuxSn4-x System: A Unified View on Their Phase Stabilities versus Valence Electron Counts  

SciTech Connect

Three ordered structures of the tetragonal BaAl4 type were identified in the Ba–Au–Sn system, from which a unified view of the interplay between the valence electron counts (VECs) and phase stabilities of these three types of derivatives can be developed. The BaNiSn3 (I4mm), ThCr2Si2 (I4/mmm), and CaBe2Ge2 (P4/nmm) type BaAuxSn4–x phases occurred respectively at x = 0.78(1)–1, 1.38(1)–1.47(1), and 1.52(1)–2.17(1), consistent with theoretical atomic “coloring” analyses that reveal an optimal VEC of 14 for the ThCr2Si2 type but larger and smaller values respectively for the BaNiSn3- and CaBe2Ge2-type structures.

Lin, Qisheng [Ames Laboratory; Miller, Gordon J. [Ames Laboratory; Corbett, John D. [Ames Laboratory

2014-05-28

412

Elevated Seismic Activity Beneath the Slumbering Morne aux Diables Volcano, Northern Dominica and the Monitoring Role of the Seismic Research Centre  

NASA Astrophysics Data System (ADS)

Since June 2009, periods of elevated seismic activity have been experienced around the flanks of Morne Aux Diables Volcano in northern Dominica. This long-dormant volcano is a complex of 7 andesitic lava domes with a central depression where a cold soufrière is evident. Prior to this activity, seismicity was very quiet except for a short period in 2000 and an intense short-lived swarm in April 2003. The most recent earthquake activity has been regularly felt by residents in villages on all flanks of the complex. In Dec 09/Jan10, scientists from the Seismic Research Centre (SRC), based in Trinidad & Tobago, in collaboration with staff of the Office of Disaster Management (ODM) and Dominica Public Seismic Network (DPSN) improved the monitoring capacity around this volcano from 1 to 7 seismic stations. Earthquakes are determined to be volcano-tectonic in nature and located at shallow depths (<4 km) beneath the central depression. Additionally, in Jan/Feb 10 geothermal sampling was undertaken and 2 permanent GPS sites were deployed. Public information leaflets prepared by SRC scientists using a "Question & Answer" format have been distributed to concerned citizens whilst many public meetings were carried out by ODM staff. Field investigations indicate that the previous Late Pleistocene activity of Morne Aux Diables switched from Pelèan dome growth and gravitational collapse to more explosive pumice-falls and associated ignimbrites, both styles forming extensive pyroclastic fans around the central complex. The town of Portsmouth is located on one of these fans ~5 km southwest of the central depression. Sporadic, short bursts of seismic activity continue at the time of writing.

Watts, R. B.; Robertson, R. E.; Abraham, W.; Cole, P.; de Roche, T.; Edwards, S.; Higgins, M.; Johnson, M.; Joseph, E. P.; Latchman, J.; Lynch, L.; Nath, N.; Ramsingh, C.; Stewart, R. C.

2012-12-01

413

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...

414

Spatially controlled electro-stimulated DNA adsorption and desorption for biochip applications.  

PubMed

The manipulation of biomolecules at solid/liquid interfaces is important for the enhanced performance of a number of biomedical devices, including biochips. This study focuses on the spatial control of surface interactions of DNA as well as the electro-stimulated adsorption and desorption of DNA by appropriate surface modification of highly doped p-type silicon. Surface modification by plasma polymerisation of allylamine resulted in a surface that supported DNA adsorption and sustained cell attachment. Subsequent high-density grafting of poly(ethylene oxide) formed a low fouling layer resistant to biomolecule adsorption and cell attachment. Spatially controlled excimer laser ablation of the surface produced patterns of re-exposed plasma polymer with high-resolution. On patterned surfaces, preferential electro-stimulated adsorption of DNA to the allylamine plasma polymer surface and subsequent desorption by the application of a negative bias was observed. Furthermore, the concept presented here was investigated for use in transfection chips. Cell culture experiments with human embryonic kidney cells, using the expression of green fluorescent protein as a reporter, demonstrated efficient and controlled transfection of cells. Electro-stimulated desorption of DNA was shown to yield significantly enhanced solid phase transfection efficiencies to values of up to 30%. The ability to spatially control DNA adsorption combined with the ability to control the binding and release of DNA by application of a controlled voltage enables an advanced level of control over DNA bioactivity on solid substrates and lends itself to biochip applications. PMID:16303297

Hook, Andrew L; Thissen, Helmut; Hayes, Jason P; Voelcker, Nicolas H

2006-05-15

415

Alliance de marques et création de valeur : une approche interorganisationnelle - Application aux marchés du commerce équitable et de l’alimentation santé  

Microsoft Academic Search

Brands, frequently being perceived as quality signals, reach today their limits on the market. Then to be differentiated and to reinforce their position, many companies launched out in brand alliances defined as the combination of two brands in a same product or a service. The previous studies on brand alliances are mainly focused on marketing aspects centered on the consumer.

Mantiaba Coulibaly

2009-01-01

416

Thme 3.8 : Application de techniques inverses aux lments face au plasma : mthode flash, estimation du flux, estimation des rsistances de contact  

E-print Network

ou interne sont obtenues à partir de la thermographie IR ou de thermocouples, pour en déduire le flux données infrarouges du JET, appliqué sur un cas sans dépôt. Cette action a été menée principalement par'un détecteur infrarouge (Cf. Figure 1). Après une brusque augmentation de température, la structure se

417

Cartographie de parametres forestiers par fusion evidentielle de donnees geospatiales multi-sources: Application aux peuplements forestiers en regeneration et feuillus matures du Sud du Quebec  

Microsoft Academic Search

Foresters are faced with difficulties to obtain sub-polygon information with the mapping methods available nowadays. The main objective of this work consisted in the development of new methods able to improve the map accuracy of regenerating forest stands and mature forest stands in the South of Quebec, Canada. The Dempster-Shafer Theory (DST) and the Dezert-Smarandache Theory (DSmT) showed their ability

Brice Mora

2009-01-01

418

IEEE Canadian Conference on Electrical and Computer Engineering, Montreal, Quebec, September 5-8, 1995. ATREF: Application des Technologies Robotiques aux Equipements  

E-print Network

for wood harvesting are diesel-powered hydraulic construction equipment retro#12;tted with special end and pose dierent operator-system interface problems, since the operator doesn't rotate with the manipulator arm as in an ex- cavator. To increase the exibility and eectiveness of these machines, electro-hydraulic

Papadopoulos, Evangelos

419

Etude analytique et numérique de la réponse en vibration à hautes fréquences d'éprouvettes de fatigue vibratoire des métaux. 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 présent travail, la fatigue vibratoire a été étudiée dans le cas du comportement élastique des matériaux en négligeant les effets thermiques pouvant influencer les champs mécaniques. La détermination de ces champs et de la longueur de résonance des éprouvettes de fatigue a été faite analytiquement et numériquement. Le calcul numérique effectué se base sur la méthode des éléments finis. Dans le but d'une comparaison des solutions analytiques et numériques, deux aciers ont été considérés : un acier martensitique (Soleil A2) et un acier austénitique 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

420

Travailleurs âgés, nouvelles technologies et changements organisationnels : un réexamen à partir de l'enquête « Reponse ». Suivi d'un commentaire de Luc Behaghel : emploi des seniors - Des effets du changement technologique aux recommandations  

Microsoft Academic Search

[fre] L'adoption par les entreprises d'innovations technologiques (micro-ordinateur, internet), de changements organisationnels ou leur ouverture au marché international posent la question de l'adaptation des travailleurs âgés (seniors) : les entreprises concernées évincent-elles plus souvent ou non les seniors de leur main-d'oeuvre ? L'analyse du stock d'emploi en 1998 confirme l'hypothèse d'un biais de ces changements défavorable aux seniors. Dans l'industrie

Patrick Aubert; Luc Behaghel; Sévane Ananian

2006-01-01

421

Le dpartement d'Etudes Slaves de l'Universit Blaise Pascal propose aux tudiants un parcours complet en tudes russes depuis la premire anne de Licence. Le cursus de russe  

E-print Network

· Le département d'Etudes Slaves de l'Université Blaise Pascal propose aux étudiants un parcours étudiantes ont toutes deux préparé un Master 1 d'études Russophones toujours à l'Université Blaise Pascal. L toujours à l'Université Blaise Pascal et occupe conjointement un emploi à mi-temps tandis que l

Sart, Remi

422

DET/MPS - THE GSFC ENERGY BALANCE PROGRAM, DIRECT ENERGY TRANSFER/MULTIMISSION SPACECRAFT MODULAR POWER SYSTEM (MACINTOSH A/UX VERSION)  

NASA Technical Reports Server (NTRS)

The DET/MPS programs model and simulate the Direct Energy Transfer and Multimission Spacecraft Modular Power System in order to aid both in design and in analysis of orbital energy balance. Typically, the DET power system has the solar array directly to the spacecraft bus, and the central building block of MPS is the Standard Power Regulator Unit. DET/MPS allows a minute-by-minute simulation of the power system's performance as it responds to various orbital parameters, focusing its output on solar array output and battery characteristics. While this package is limited in terms of orbital mechanics, it is sufficient to calculate eclipse and solar array data for circular or non-circular orbits. DET/MPS can be adjusted to run one or sequential orbits up to about one week, simulated time. These programs have been used on a variety of Goddard Space Flight Center spacecraft projects. DET/MPS is written in FORTRAN 77 with some VAX-type extensions. Any FORTRAN 77 compiler that includes VAX extensions should be able to compile and run the program with little or no modifications. The compiler must at least support free-form (or tab-delineated) source format and 'do do-while end-do' control structures. DET/MPS is available for three platforms: GSC-13374, for DEC VAX series computers running VMS, is available in DEC VAX Backup format on a 9-track 1600 BPI tape (standard distribution) or TK50 tape cartridge; GSC-13443, for UNIX-based computers, is available on a .25 inch streaming magnetic tape cartridge in UNIX tar format; and GSC-13444, for Macintosh computers running AU/X with either the NKR FORTRAN or AbSoft MacFORTRAN II compilers, is available on a 3.5 inch 800K Macintosh format diskette. Source code and test data are supplied. The UNIX version of DET requires 90K of main memory for execution. DET/MPS was developed in 1990. A/UX and Macintosh are registered trademarks of Apple Computer, Inc. VMS, DEC VAX and TK50 are trademarks of Digital Equipment Corporation. UNIX is a registered trademark of AT&T Bell Laboratories.

Jagielski, J. M.

1994-01-01

423

Dpartement R & T Giulio.Manzonetto@lipn.univ-paris13.fr Module M1105 -Introduction aux systmes informatiques  

E-print Network

premier plan. 4. Suspendre à nouveau l'application puis reprendre son exécution en tâche de fond. Peut affichages obtenus : >X1=3 >Y1=10 >Z1=4 >export Y1 >env | grep X1= >echo $X1 >echo $x1 >env | grep Y1= >unset Y1 >export X1 >bash >env | grep X1= >echo $Z1 >exit >echo $Z1 Réseaux -- Partie 1 17 IUT R

Giulio, Manzonetto

424

LA TECHNOLOGIE GAN ET SES APPLICATIONS POUR L'ELECTRONIQUE ROBUSTE, HAUTE FREQUENCE ET DE  

E-print Network

technologies carbure de silicium (SiC) et nitrure de gallium (GaN) possèdent des qualités intrinsèques réalisation de dispositifs optiques (GaN et alliages InP, Al, P), ce qui autorise un spectre d'applications du visible aux ultraviolets, en émission et en détection : le matériau GaN est le seul qui puisse prétendre à

Boyer, Edmond

425

Ampleur et impact des évènements indésirables graves liés aux soins: étude d'incidence dans un hôpital du Centre-Est tunisien  

PubMed Central

Introduction La prévention des événements indésirables représente une priorité de santé du fait de leur fréquence et de leur gravité potentielle. Ce travail a été mené afin d'avoir un diagnostic de la situation épidémiologique relative aux événements indésirables survenant dans notre hôpital. Méthodes Une étude prospective a été menée auprès de tous les patients qui ont été hospitalisés au CHU Farhat Hached - Sousse (Tunisie) sur une période d'un mois dans quatorze services de l'hôpital. La détection d'évènement indésirable grave (EIG) était basée sur les critères adoptés dans différentes études. Les tests T et Chi 2 ont été utilisés pour identifier les facteurs contribuant à l'apparition d'évènements indésirables. Résultats Au total, 162 EIG ont été identifiés pendant la période. 45% de ces évènements étaient des infections nosocomiales. Ces EIG ont eu comme conséquences un décès chez 9,2% des patients, la mise en jeu du pronostic vital de 26% des patients et la prolongation de la durée de séjour chez 61,7% d'entre eux. L'admission dans des circonstances particulières et l'exposition à des soins invasifs étaient identifiés comme des facteurs de risque potentiels EIG. Conclusion Le renforcement de la stratégie de gestion des risques sanitaires en ciblant préférentiellement le risque infectieux constitue une étape fondamentale dans l'amélioration de la sécurité des patients au sein de notre établissement de santé. PMID:24711868

Bouafia, Nabiha; Bougmiza, Iheb; Bahri, Fathi; Letaief, Mondher; Astagneau, Pascal; Njah, Mansour

2013-01-01

426

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 Å, c?5.278-5.286 Å, 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 Å), 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

427

Application of the polynomial chaos expansion to multiphase CFD : a study of rising bubbles and slug flow  

E-print Network

Part I of this thesis considers subcooled nucleate boiling on the microscale, focusing on the analysis of heat transfer near the Three-Phase (solid, liquid, and vapor) contact Line (TPL) region. A detailed derivation of ...

Langewisch, Dustin R

2014-01-01

428

Application Application Notes  

E-print Network

Application Notes #12;Application Notes Intelligent Alphanumeric Purdy Electronics Corporation Terminals RS, R/W I/O Terminals DB0 to DB7 #12;Application Notes Intelligent Alphanumeric Purdy Electronics

Grantner, Janos L.

429

Full dimensional Franck-Condon factors for the acetylene A? (1)Au-X? (1)?(g)(+) 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? 1?g+ 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

430

Les recommandations de prise en charge des complications métaboliques associées aux antipsychotiques de deuxième génération chez les enfants et les adolescents  

PubMed Central

HISTORIQUE : Les antipsychotiques de deuxième génération s’associent souvent à des complications métaboliques. Ces médicaments sont utilisés plus souvent pour le traitement des troubles de santé mentale chez les enfants, ce qui a requis l’élaboration de lignes directrices officielles sur la surveillance de leur innocuité et de leur efficacité. Des lignes directrices ont déjà été élaborées pour surveiller les complications métaboliques et neurologiques. Afin d’aider les praticiens qui effectuent ces interventions de surveillance, une série de recommandations thérapeutiques complémentaires a été élaborée pour les cas où l’on observe des mesures ou des résultats anormaux. OBJECTIF : Créer des recommandations probantes afin de contribuer à la prise en charge des complications métaboliques chez les enfants traités au moyen d’antipsychotiques de deuxième génération. MÉTHODOLOGIE : Les auteurs ont procédé à une analyse systématique des publications sur les complications métaboliques des antipsychotiques de deuxième génération chez les enfants. Les membres du groupe consensuel ont évalué l’information recueillie grâce à l’analyse bibliographique systématique et ont fait appel à un processus de groupe nominal pour parvenir à un consensus à l’égard de recommandations thérapeutiques. Dans la mesure du possible, ils se sont reportés aux lignes directrices existantes sur l’évaluation et le traitement des anomalies métaboliques chez les enfants. RÉSULTATS : Des recommandations probantes sont présentées pour contribuer à la prise en charge des complications métaboliques, y compris la prise de poids, l’augmentation du tour de taille, l’élévation des taux de prolactine, de cholestérol, de triglycérides et de glucose, les épreuves de fonction hépatique anormales et les études thyroïdiennes anormales. CONCLUSION : Il faut recourir à des mesures de surveillance convenables lorsqu’on prescrit des antipsychotiques de deuxième génération. Les présentes lignes directrices thérapeutiques orientent les cliniciens quant à la prise en charge clinique des complications métaboliques lorsqu’elles se produisent. PMID:24082815

Ho, Josephine; Panagiotopoulos, Constadina; McCrindle, Brian; Grisaru, Silviu; Pringsheim, Tamara

2012-01-01

431

Transposition des processus membranaires biologiques aux traitements des effluents métallifères peu chargés. Conception et étude chimique d'une pompe ionique uranifère. Transport, contre-transport, couplage positif  

NASA Astrophysics Data System (ADS)

An ionic pump has been devided thanks to au “liquid-liquid" extraction-reextration where the extraction compartment and the reextraction compartment are put in contact with one another through the membrane composed of an mediator diluted in the kerosene. We have applied this process to the system: uranyle nitrate, nitric acid-phosphate tributyle, kerosene-sodium carbonate. Interesting performances have been realised for diluted solutions (100 ppm). The chemicals parameters has allowed to obtain the variables giving the extraction and reextraction efficiency optimum. A chemical modelisation has allowed to identify the extraction mechanism. The classical behaviour obtained in agitated surroundings has been found again. The membrane can work thanks to the “activation" by the solute of the carrier at one interface and to the “deactivation" at the other interface, both of these mechanisms of the active transport creating a real “ionic pumping". Une pompe ionique est mise au point grâce à une ensemble “extraction-réextraction" “liquide-liquide" où le compartiment extraction et le compartiment réextraction sont mis en contact par l'intermédiaire d'une membrane contenant un transporteur dilué dans le kérosène. Ce procédé est appliqué aux ions uranyles. Des rendements intéressants sont obtenus pour des solutions diluées (100 ppm). L'étude des variables a permis de déterminer des paramètres chimiques donnant des rendements d'extraction et de réextration optimum. Le comportement symétrique des deux compartiments montre que nous avons un transport, contre-transport, couplage positif. Une modélisation chimique a permis d'identifier les mécanismes d'extraction. Le comportement classique obtenu en milieu agité est retrouvé. La pompe peut fonctionner grâce à l'activation du transporteur par le cosoluté contenu dans le compartiment d'extraction et à la désactivation à la sortie de la membrane par le cosoluté contenu dans le compartiment réextraction créant un pompage ionique.

Hasaine-Sadi, F.; Benhassaine, A.; Ait-Amar, H.

1999-09-01

432

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

PubMed Central

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

2014-01-01

433

Solid-liquid separation of dairy manure with PAM and chitosan polymers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Organic polymers are useful to increase separation of suspended solids and carbon compounds from liquid swine manure, but experiences with dairy manure are limited. In this experiment, two polymers, a synthetic polyacrylamide (PAM) and a natural chitosan were used to increase separation of suspended...

434

Solid–liquid–gas equilibrium by cubic equations of state and association  

Microsoft Academic Search

In a method presented by Lang and Wenzel [E. Lang, H. Wenzel, Extension of a cubic equation of state to solids, Fluid Phase Equil. 51 (1989) 101] an associated species is used to account for a solid phase in phase equilibrium calculation by an equation of state. In binary systems, the method was also shown to allow for solid solutions.

D. Geanã; H. Wenzel

1999-01-01

435

Pressure effect on the solid liquid equilibrium forms of odd normal alkanes  

NASA Astrophysics Data System (ADS)

This paper describes the changes in equilibrium forms of small odd-numbered normal alkane crystals (carbon number: 9, 11 and 13) as functions of temperature, pressure and the carbon number. The crystals were grown by increasing pressure of the liquids using a diamond anvil cell (DAC). After single crystals were prepared in the DAC under high pressure, the crystals were maintained for a long period under constant pressure and temperature. During the changes in the shape of the single crystal, both orthorhombic (high-pressure phase) and hexagonal (low-pressure phase) shapes appeared. These crystal shape variations, depending on pressure and temperature, were consistent for the anisotropies of the orthorhombic and hexagonal unit cells predicted from the molecular arrangements in the unit cells. Hexagonal thin films of n-tridecane could thus grow from the edges of the c-planes of orthorhombic thick plate of parallelogram.

Shigematsu, Koji; Saito, Yutaka; Saito, Kana; Takahashi, Yoshinori

2008-11-01

436

Molecular Dynamics Simulation of Argon in Solid-Liquid Phase Transition Region  

Microsoft Academic Search

The microstructure of 256 argon atoms located on ideal fcc lattice sites on which periodic boundary conditions have been applied at the vicinity of transition temperature has been investigated. The forces among atoms have been derived from Lennard-Jones potential energy function and the equations of motion of the system have been solved by using the Verlet algorithm. The variations in

Soner Özgen; Veysel Kuzucu; Osman Adigüzel

1997-01-01

437

Preferential adsorption of solid monolayers of hydrocarbons over fluorocarbons at the solid/liquid interface  

NASA Astrophysics Data System (ADS)

A novel combination of sensitive calorimetry, neutron diffraction and NMR have been used to investigate the preferential adsorption and phase behaviour of the solid monolayers absorbed onto graphite from binary n-alkane/ n-perfluoroalkane mixtures. The results indicate that the alkane preferentially adsorbs for essentially all mixture compositions to the complete exclusion of the fluoroalkane. The fluoroalkane monolayer is completely displaced from the graphite surface on addition of the equivalent of just 1 ML of alkane to the mixture. The hydrocarbon is preferentially adsorbed both as solid monolayer and as a liquid.

Parker, J. E.; Clarke, S. M.; Perdigón, A. C.

2007-09-01

438

Manipulation of powder characteristics by interactions at the solid-liquid interface: 1-sulphadiazine.  

PubMed

A solvent-treatment technique aiming at manipulating the properties of powdered materials is reported. Potentials of the technique were assessed using sulphadiazine (SD). A suspension of the drug in a preselected solvent (5% aqueous ammonia solution) was stirred under controlled conditions. The solvent was subsequently removed and the material dried. The effect of experimental variables such as stirring speed and time, powder/solvent ratio and inclusion of additives (Tween 80, sodium chloride and PVP) on the properties of solvent treated SD was assessed. Data obtained were compared with those for SD recrystallized under identical conditions. Solvent treatment of SD in the absence of additives resulted in a limited change in crystal morphology as indicated by SEM. This was associated with improved flowability and a limited reduction in dissolution rate relative to untreated SD. On the other hand, recrystallized SD exhibited superior flowability but a considerably low dissolution rate. Solvent treatment of SD in the presence of 2% PVP produced a microgranular directly compressible material. PMID:10425378

Hammouda, Y E; El-Khordagui, L K; Darwish, I A; El-Kamel, A H

1999-08-01

439

Storage of thermal energy by solid-liquid phase change - Temperature drop and heat flux  

Microsoft Academic Search

A circular tube filled with a phase change material (pcm) and situated in a fluid environment is analyzed. During energy storage, heat flows from the environment into the pcm, causing the pcm to melt. In heat extraction, heat flows from the pcm into the environment and the pcm solidifies. Results are found for two cases: heat extraction as a uniform

N. Shamsundar; E. M. Sparrow

1974-01-01

440

Nuclear magnetic resonance measurement of ammonia diffusion in dense solid-liquid slurries  

SciTech Connect

The diffusion of ammonium ions in aqueous solutions was measured by nuclear magnetic resonance (NMR) using the pulsed field gradient (PFG) method. The ammonium ions were obtained from aqueous solutions of ammonium chloride, ammonium sulfate, ammonium bicarbonate, and ammonium hydroxide. The translation diffusion of the ammonium ions was determined by measuring the diffusion of nitrogen nuclei ({sup 14}N and {sup 15}N) in solution. Our results showed that the ammonium diffusion coefficient can be measured in aqueous solutions with concentrations as low as 20 x 10{sup -3} M. Typical values measured for the diffusion coefficient of the ammonium ion are 2 x 10{sup -5} cm{sup 2/s} ({+-}10%), similar to the values found for pure water. Due to the effect of the solution pH upon the NMR relaxation parameters for {sup 14}N, measurements are constrained to pH values below 8.5. However, {sup 15}N labeled ammonium is less sensitive to the solution pH, extending the measurement range to pH of 9.5. Diffusion measurements were conducted with solutions of varying viscosity and porosity. The results show that the solution viscosity has a measureable impact on the diffusion coefficient. The diffusion coefficient is almost inversely proportional to the relative viscosity of the solution, irrespective of how the viscosity is increased. Further, a randomly-packed porous bed of 200 mm PMMA resulted in a reduction of {approximately}30% in the diffusion coefficient as a result of hindered diffusion.

Bobroff, S.; Phillips, R.J. [Univ. of California, Davis, CA (United States). Dept. of Chemical Engineering; Shekarriz, A. [Pacific Northwest National Lab., Richland, WA (United States)

1997-09-01

441

Parallel gastric emptying of nonhydrolyzable fat and water after a solid-liquid meal in humans.  

PubMed

Our aim was to examine the control of gastric emptying of the oil phase of a mixed solid and liquid meal. Previous studies had shown that liquid dietary fats normally leave the stomach at a slower rate than does water. We wished to determine whether the slower emptying of fats was due to the physical characteristics of food (lower density and greater viscosity than water), to retardation by duodenal feedback mechanisms, or whether both factors contributed. Thus, we quantified the emptying rates of water and sucrose polyester (a nonabsorbable analog of dietary fat) ingested by healthy volunteers as a mixed solid and liquid meal. Gastric emptying was quantified by an intubation-perfusion method incorporating an occlusive jejunal balloon to facilitate recovery. Four phase-specific, nonabsorbable markers were used. [14C[Sucrose octaoleate and polyethylene glycol were incorporated in the meal and traced the lipid and water phases, respectively; [3H]glycerol triether and phenolsulfonphthalein were used as duodenal recovery markers. Sucrose polyester (substituting for dietary fat) was emptied very rapidly, and at about the same rate as was water, in contrast to natural fat, which empties very slowly. Emptying of water was rapid and comparable to that observed after mixed meals containing natural fat. These results imply that gastric emptying of the oil phase is controlled by receptors sensitive to the hydrolytic products of fat digestion and that the slow emptying of dietary fat is not simply due to its lower density. PMID:7060909

Cortot, A; Phillips, S F; Malagelada, J R

1982-05-01

442

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...

443

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

444

Dynamic electrowetting and dewetting of ionic liquids at a hydrophobic solid-liquid interface.  

PubMed

The dynamic electrowetting and dewetting of ionic liquids are investigated with high-speed video microscopy. Five imidazolium-based ionic liquids ([BMIM]BF(4), [BMIM]PF(6), [BMIM]NTf(2), [HMIM]NTf(2), and [OMIM]BF(4)) are used as probe liquids. Droplets of ionic liquids are first spread on an insulated electrode by applying an external voltage (electrowetting) and then allowed to retract (dewetting) when the voltage is switched off. The base area of the droplet varies exponentially during both the electrowetting and retraction processes. The characteristic time increases with the viscosity of the ionic liquid. The electrowetting and retraction kinetics (dynamic contact angle vs contact line speed) can be described by the hydrodynamic or the molecular-kinetic model. Energy dissipation occurs by viscous and molecular routes with a larger proportion of energy dissipated at the three-phase contact line when the liquid meniscus retracts from the solid surface. The outcomes from this research have implications for the design and control of electro-optical imaging systems, microfluidics, and fuel cells. PMID:23362860

Li, Hua; Paneru, Mani; Sedev, Rossen; Ralston, John

2013-02-26

445

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

446

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

447

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 Young’s 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

448