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1

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

National Technical Information Service (NTIS)

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 gra...

J. B. Duncan

1998-01-01

2

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 ...

Salter, Ms.

2009-10-22

3

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

4

Solids, Liquids, and Gases  

NSDL National Science Digital Library

Objective: Students will be introduced to solids, liquids, and gases. Students will identify key characteristics of the three states of matter. Everything is made of matter. Matter is made of atoms. Matter makes up solids, liquids, and gases. What are some similarities and differences between solids, liquids, and gases? Follow the link below to find out. Characteristics of the States of Matter The previous website gave some general characteristics for solids, liquids, and gases. Now ...

Rohlfing, Mrs.

2010-10-22

5

Atomistic simulation of solid-liquid coexistence for molecular systems: Application to triazole and benzene  

NASA Astrophysics Data System (ADS)

A method recently developed to rigorously determine solid-liquid equilibrium using a free-energy-based analysis has been extended to analyze multiatom molecular systems. This method is based on using a pseudosupercritical transformation path to reversibly transform between solid and liquid phases. Integration along this path yields the free energy difference at a single state point, which can then be used to determine the free energy difference as a function of temperature and therefore locate the coexistence temperature at a fixed pressure. The primary extension reported here is the introduction of an external potential field capable of inducing center of mass order along with secondary orientational order for molecules. The method is used to calculate the melting point of 1-H-1,2,4-triazole and benzene. Despite the fact that the triazole model gives accurate bulk densities for the liquid and crystal phases, it is found to do a poor job of reproducing the experimental crystal structure and heat of fusion. Consequently, it yields a melting point that is 100 K lower than the experimental value. On the other hand, the benzene model has been parametrized extensively to match a wide range of properties and yields a melting point that is only 20 K lower than the experimental value. Previous work in which a simple ``direct heating'' method was used actually found that the melting point of the benzene model was 50 K higher than the experimental value. This demonstrates the importance of using proper free energy methods to compute phase behavior. It also shows that the melting point is a very sensitive measure of force field quality that should be considered in parametrization efforts. The method described here provides a relatively simple approach for computing melting points of molecular systems.

Eike, David M.; Maginn, Edward J.

2006-04-01

6

Les ADAF : Application aux binaires X  

NASA Astrophysics Data System (ADS)

Based on the fundamental review by Narayan et al. (1998), this lecture for the ``23ieme Ecole du CNRS de Goutelas'' on binary systems describes the properties of advection-dominated accretion flows (ADAFs) and their applications to black hole X-ray binaries. The possibility of using ADAFs to explore the event horizons of black holes is highlighted.

Olive, Jean-Francois

2001-01-01

7

Solids, Liquids, and Gases  

NSDL National Science Digital Library

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

Sibley, Ms.

2009-10-22

8

Application de la combustion catalytique aux turbines à gaz  

NASA Astrophysics Data System (ADS)

La réduction des émissions d'oxydes d'azote sur turbines à gaz est obtenue par diminution de la température au sein de la chambre de combustion. Les techniques possibles comprennent l'injection d'eau ou de vapeur, la combustion pauvre et l'oxydation catalytique. Parmi celles-ci, la dernière est la plus prometteuse en terme de coûts et de performances, avec des émissions de NOx ramenées à un seul chiffre (typiquement inférieures à 3 ppm). L'IFP travaille depuis maintenant 10 ans sur l'adaptation de la combustion catalytique aux turbines à gaz. Les études ont été conduites au travers de projets européen tels que AGATA (Advance Gas Turbine for Automotive Application) et ULECAT (Ultra Low CATalytic combustor for dual fuel gas turbine). Le premier projet était destiné au développement de véhicules hybrides et le second à la combustion stationnaire de biogaz et de combustible Diesel. Les études en cours dans ce domaine portent sur le développement d'une unité de cogénération intégrant une microturbine à combustion catalytique. Les travaux menés à l'IFP concernent la mise au point de catalyseurs répondant aux exigences de la combustion catalytique en turbine à gaz et le développement de chambres de combustion permettant la mise en oeuvre de ces catalyseurs.

Lebas, E.; Martin, G. H.

2002-04-01

9

Solids, Liquids, and Gases  

NSDL National Science Digital Library

What do you know about the 3 states of matter? Good Morning 2nd graders! Today we will be learning about the different states of matter : solids, liquids, and gases . Have fun working with your partner and follow directions carefully! First, make sure you get a 3 column graphic organizer and fill ...

Swaim, Mrs.

2012-12-01

10

Application de Conducteurs Optiques Aux Measures en Mécanique des Fluides  

Microsoft Academic Search

Dans cette note on donne des indications sur les possibilités d'une nouvelle méthode de mesure que les auteurs ont commencé d'appliquer. On présente l'utilisation de fibres optiques dans un cas d'étude microscopique en hydrodynamique des milieux poreux. D'autres applications sont évoquées. Une amorce est faite dans la perspective d'un traitement numérique des informations que cette méthode permet d'acquérir.

R. Brodt; O. Scrivener; L. Zilliox

1974-01-01

11

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

2013-06-20

12

Solid–liquid expression of cellular materials enhanced by pulsed electric field  

Microsoft Academic Search

The mechanism of solid–liquid expression enhanced by pulsed electric field (PEF) is studied for agrofood cellular materials. The application of PEF induces the permeabilization of cellular membranes and facilitates the subsequent cells rupture by mechanical compression. The solid–liquid expression was preceded by mechanical pre-compaction of sugar beet slices under a constant pressure, application of PEF treatment under the same pressure,

Hazem Bouzrara; Eugene Vorobiev

2003-01-01

13

Application of the New Decommissioning Regulation to the Nuclear Licensed Facilities (NLF) at Fontenay-aux-Roses's Nuclear Center (CEA)  

Microsoft Academic Search

This abstract describes the application of the new decommissioning regulation on all Nuclear Licensed Facilities (NLF is to say INB in French) at Fontenay-aux-Roses's Center (CEA\\/FAR). The decommissioning process has been applied in six buildings which are out of the new nuclear perimeter proposed (buildings no 7, no 40, no 94, no 39, no 52\\/1 and no 32) and three

Josiane Sauret; Laurence Piketty; Michel Jeanjacques

2008-01-01

14

Application potential of advanced instrumental methods for on-line automated composition analysis of solid\\/liquid fossil energy process materials. Volume I. Nuclear methods. [684 references  

Microsoft Academic Search

A study has been conducted to identify and examine potential novel on-line techniques for analysis of condensed phase material in coal process streams and vessels for fossil energy applications. This portion of the study (Volume 1) deals with the potential of techniques based on nuclear principles for sensor development for analytic applications. The study has encompassed methods in use in

Herzenberg

1983-01-01

15

Diffusion de neutrons aux petits angles : application à l'étude des macromolécules biologiques en solution  

NASA Astrophysics Data System (ADS)

La diffusion de neutrons aux petits angles (DNPA) permet de sonder les propriétés statiques de la matière sur une échelle spatiale allant de quelques dixièmes à quelques dizaines de nanomètres. Cette technique est ainsi particulièrement bien adaptée à l'étude des macromolécules en solution. Il est possible d'accéder à des grandeurs moyennes qui caractérisent la conformation qu'adoptent les macromolécules ou leurs interactions thermodynamiques. Le cours expose à des non spécialistes les différentes grandeurs mesurables et les méthodes à utiliser pour y accéder. En particulier sont abordées: 1) les mesures effectuées dans la limite du vecteur de diffusion nul qui sont liées aux fluctuations de concentration; 2) les notions de facteur de forme, de facteur de structure dots 3) les différentes façon de jouer avec le contraste. Les notions introduites sont illustrées par des exemples didactiques empruntés à la littérature et concernant des macromolécules biologiques en solution.

Lairez, D.; Pelta, J.

2005-11-01

16

Application of the New Decommissioning Regulation to the Nuclear Licensed Facilities (NLF) at Fontenay-aux-Roses's Nuclear Center (CEA)  

SciTech Connect

This abstract describes the application of the new decommissioning regulation on all Nuclear Licensed Facilities (NLF is to say INB in French) at Fontenay-aux-Roses's Center (CEA/FAR). The decommissioning process has been applied in six buildings which are out of the new nuclear perimeter proposed (buildings no 7, no 40, no 94, no 39, no 52/1 and no 32) and three buildings have been reorganized (no 54, no 91 and no 53 instead of no 40 and no 94) in order to increase the space for temporary nuclear waste disposal and to reduce the internal transports of nuclear waste on the site. The advantages are the safety and radioprotection improvements and a lower operating cost. A global safety file was written in 2002 and 2003 and was sent to the French Nuclear Authority on November 2003. The list of documents required is given in the paragraph I of this paper. The main goals were two ministerial decrees (one decree for each NLF) getting the authorization to modify the NLF perimeter and to carry out cleaning and dismantling activities leading to the whole decommissioning of all NLF. Some specific authorizations were necessary to carry out the dismantling program during the decommissioning procedure. They were delivered by the French Nuclear Safety Authority (FNSA) or with limited delegation by the General Executive Director (GED) on the CEA Fontenay-aux-Roses's Center, called internal authorization. Some partial dismantling or decontamination examples are given below: - evaporator for the radioactive liquid waste treatment station (building no 53): FNSA authorization: phase realised in 2002/2003. - disposal tanks for the radioactive liquid waste treatment station (building no 53) FNSA authorization: phase realised in 2004, - incinerator for the radioactive solid waste treatment station (building no 07): FNSA authorization: operation realised in 2004, - research equipments in the building no. 54 and building no. 91: internal authorization ; realised in 2005, - sample-taking to characterize solvent contained in one tank of Petrus installation (NLF 57, building 18) for radiological and chemical analysis needed to prepare the treatment and the evacuation of these wastes : internal authorization ; realised in june 2005. It was possible to plan the whole decommissioning process on the Nuclear Licensed Facilities of Fontenay-aux-Roses's Center (CEA/FAR) taking into account the French new regulation and to plan a coherent and continue program activity for the dismantling process. For the program not to be interrupted during the administrative process (2003-2006), specific authorisations have been delivered by the French Nuclear Safety Authority or by the General Executive Director (GED) on the CEA Fontenay-aux- Roses's Center (internal authorization). The time schedule to complete the entire program is until 2017 for NLF 'Procede' (NLF no 165) and until 2018 for NLF 'Support' (NLF no 166). Since 1999, an annual press meeting has been organised by the Fontenay-aux-Roses's Center Head Executive Manager.

Sauret, Josiane [Commissariat a l'Energie Atomique, Direction du Centre de Fontenay-aux-Roses, Cellule de Surete nucleaire, de controle des Matieres, de controle des Transports et de la Qualite, 18 route du Panorama BP 6 - 92265 Fontenay-aux-Roses Cedex (France); Piketty, Laurence; Jeanjacques, Michel [Commissariat a l'Energie Atomique, Direction de l'Energie Nucleaire, Direction deleguee des Activites Nucleaires de Saclay, Departement des Reacteurs et des Services Nucleaires, service d'Assainissement de Fontenay-aux-Roses, 18 route du Panorama BP 6 - 92265 Fontenay-aux-Roses Cedex (France)

2008-01-15

17

Solid liquid interfacial energy of aminomethylpropanediol  

NASA Astrophysics Data System (ADS)

The grain boundary groove shapes for equilibrated solid aminomethylpropanediol, 2-amino-2 methyl-1.3 propanediol (AMPD) with its melt were directly observed by using a horizontal temperature gradient stage. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficient (?), solid-liquid interfacial energy (?SL) and grain boundary energy (?gb) of AMPD have been determined to be (5.4 ± 0.5) × 10-8 K m, (8.5 ± 1.3) × 10-3 J m-2 and (16.5 ± 2.8) × 10-3 J m-2, respectively. The ratio of thermal conductivity of equilibrated liquid phase to solid phase for the AMPD has also been measured to be 1.12 at the melting temperature.

Ocak, Yavuz; Akbulut, Sezen; Ke?lio?lu, Kaz?m; Mara?l?, Necmettin

2008-03-01

18

Application du groupe de renormalisation aux conducteurs organiques quasi-unidimensionnels soumis a un champ magnetique  

NASA Astrophysics Data System (ADS)

Des conducteurs organiques fortement anisotropes presentent, sous l'effet d'un champ magnetique, une etonnante variete de proprietes physiques tel que: l'effet Shubnikov-de Haas, l'effet de Haas-van-Alphen, l'existence de cascades d'ondes de densite de spin apparentees a l'effet Hall quantique, reentrance vers la phase metallique pouvant provenir d'un 'breakdown' magnetique, et tout recemment la possibilite d'un confinement charge induit par le champ magnetique. A cela s'ajoute les nombreuses caracteristiques deja apparues en variant la pression hydrostatique ou la substitution chimique: separation spin-charge, localisation de la charge, transition spin-Peierls, antiferromagnetisme itinerant ou non, supraconductivite, et l'existence d'une frontiere commune entre les phases supraconductrice et antiferromagnetique. En vue de completer la description theorique du diagramme de phase generalise des conducteurs organiques, nous adaptons et elargissons la methode du groupe de renormalisation quantique (GRQ) au cas ou le champ magnetique est non nul. On sait deja que cette methode permet de resoudre le dilemme tout particulier des composes Q-1D, soit leur capacite de produire des transitions de phase malgre leur forte anisotropie et consequemment de leur faible dimensionalite. Cette methode est deja utilisee pour decrire le diagramme de phase temperature versus pression des sels de Bechgaard, de leurs analogues souffres et mixtes. Le GRQ permet aussi de comprendre comment des systemes anisotropes comme les conducteurs organiques peuvent se comporter comme des liquides de Luttinger a haute temperature et comme des liquides de Fermi ou condenses a basse temperature. Nous montrons que l'introduction d'un champ magnetique dans un regime de saut coherent interchai ne a deux particules n'apporte que de simples corrections aux lois d'echelles dans le canal zero son, alors qu'il introduit un mecanisme de brisure de paire dans le canal Cooper. Dans le regime de saut coherent a une particule, la situation est plus complexe puisque la structure de bande et la forme de la surface de Fermi deviennent pertinentes. Sous bon nesting, un champ magnetique le champ magnetique defavorise les phases magnetiques du type habituellement observe en champ nul. Nous obtenons en effet que leur temperature de transition diminue avec le champ magnetique. Sous deviations au nesting suffisant pour detruire l'ordre magnetique a champ nul, nous montrons que le nesting quantifie est compatible avec l'analyse du GRQ pour des champ faibles et intermediaires. Ainsi, le nesting quantifie fournit toujours une excellente base de description des cascades de phases d'onde de densite de spin induite en champ magnetique. D'autre part, l'utilisation du GRQ permet de mettre en evidence l'existence d'un regime de champ fort. Dans ce regime le mouvement coherent des electrons dans la direction transverse aux chai ne est fortement reduit. De cette reduction de la coherence transverse les regles de renormalisation 1D qui persistent a une temperature plus basse que dans les autres regimes. Ceci donne la possibilite d'atteindre grace au champ magnetique des etats de type localisation de charge et spin-Peierls qui sont habituellement observes, en champ nul, dans des composes ayant un caractere unidimensionnel beaucoup plus prononce.

Hubert, Laurent

19

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

20

A Theory of Cavity Formation at Solid-Liquid Interfaces.  

National Technical Information Service (NTIS)

A theory of cavity formation at solid-liquid interfaces was derived which describes cavitational behavior in terms of the dispersion forces and of the surface tension of the liquid. The resulting relationships are easily applied to experimental data with ...

D. J. Cotton

1969-01-01

21

Investigation in solid–liquid extraction: influence of ultrasound  

Microsoft Academic Search

The extraction of active principles or oils from vegetable products by means of an appropriate solvent is a classical unit operation in chemical engineering. The aim of the present work is to improve the yield or the selectivity of the extraction using ultrasound. Two solid–liquid extractions have been investigated: pyrethrines from pyrethrum flowers (Chrysanthemum cineraria) and oil from woad seeds

M. Romdhane; C. Gourdon

2002-01-01

22

Investigation of Solid/Liquid Interface Temperatures Via Isenthalpic Solidification.  

National Technical Information Service (NTIS)

Isenthalpic solidification of a pure supercooled liquid is shown to result in either a two-phase solid/liquid mixture in invariant equilibrium or a single-phase, totally solid material in univariant equilibrium, depending on the level of supercooling prio...

M. E. Glicksman R. J. Schaefer

1967-01-01

23

SOLID\\/LIQUID EXTRACTION OF ZINC FROM EAF-DUST  

Microsoft Academic Search

The solid\\/liquid extraction of nonferrous heavy metals was investigated. This process may be of technical importance in the upgrading of dust from steel mills and from electrical arc furnaces (EAF-dust). Extraction was carried out with aqueous acetic acid. Objectives of the project were the evaluation of partition data and the investigation of extraction kinetics. The extraction efficiency of the substances

T. Hilber; R. Marr; M. Siebenhofer; W. Zapfel

2001-01-01

24

Etude de l'Application des Systemes Experts aux Projets Spatiaux (Study of Expert System Applications to Space Projects).  

National Technical Information Service (NTIS)

The applicability of artificial intelligence and expert systems to space projects is discussed and the potential utilization areas are identified, including thermal analysis, electric systems, optical systems, planning, design data bases, image processing...

M. Guerin

1986-01-01

25

Applications industrielles du code aux elements finis N3S. (Industrial applications of N3S finite element code).  

National Technical Information Service (NTIS)

The Research and Development Division of EDF (French utilities) has been working since 1982 on N3S, a 3D finite element code for simulating turbulent incompressible flows (Chabard et al., 1992) which has many applications nowadays dealing with internal fl...

J. P. Chabard G. Pot A. Martin

1993-01-01

26

Dissolving Solids, Liquids, and Gases | Inquiry in Action  

NSDL National Science Digital Library

In this series of six investigations, students will participate in activities that help them better understand the different factors that affect the solubility of solids, liquids, and gases. First, students will add sugar and food coloring to different liquids to discover that substances donât necessarily dissolve in all liquids. Students will then add cocoa mix to hot and cold water, and see that this solute dissolves better in hot water. However, the following teacher demonstration shows that increasing the temperature of water has very little effect on the solubility of salt. Students also experiment with the effect of temperature on carbon dioxide gas dissolved in water. Students should conclude that temperature affects the solubility of substances in different ways. As a culminating challenge, students use their knowledge of dissolving solids, liquids, and gases in water to create a fizzy lemon soda.

Society, American C.

2010-07-02

27

Nonlinearity of acoustic waves at solid-liquid interfaces  

Microsoft Academic Search

The small-amplitude and finite-amplitude propagation characteristics of laser line source excited and laser detected Scholte waves are investigated. Acoustic waves with Mach numbers up to 0.054 are observed at the interface between water and glass. In our case of a hard solid-liquid interface, the Scholte wave propagates very much like a bulk wave, for which the simple-wave equation holds. The

Christ Glorieux; Kris van de Rostyne; Vitalyi Gusev; Weimin Gao; Walter Lauriks; Jan Thoen

2002-01-01

28

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

29

Application potential of advanced instrumental methods for on-line automated composition analysis of solid\\/liquid fossil energy process materials. Volume 2. Non-nuclear methods. [583 references cited  

Microsoft Academic Search

A study has been conducted to identify and examine potential novel on-line techniques for analysis of condensed phase material in coal process streams and vessels for fossil energy applications. This portion of the study (Volume II) deals with the potential of techniques based on non-nuclear principles for sensor development for analytic applications. A companion volume deals with nuclear methods. The

Herzenberg

1984-01-01

30

Solid-liquid phase equilibria from free-energy perturbation calculations  

NASA Astrophysics Data System (ADS)

A method for calculating free-energy differences based on a free-energy perturbation (FEP) formalism in an alloy system described by two different Hamiltonians is reported. The intended application is the calculation of solid-liquid phase equilibria in alloys with the accuracy of first-principles electronic density-functional theory (DFT). For this purpose free energies are derived with a classical interatomic potential, and FEP calculations are used to compute corrections to these reference values. For practical applications of this approach, due to the relatively high computational cost of DFT calculations, it is critical that the FEP calculations converge rapidly in terms of the number of samples used to estimate relevant ensemble averages. This issue is investigated in the current study employing two classical interatomic-potential models for Ni-Cu. These models yield differences in predicted phase-boundary temperatures of approximately 100 K, comparable to those that might be expected between a DFT Hamiltonian and a well-fit classical potential. We show that for pure elements the FEP calculations converge rapidly with the number of samples, yielding free-energy differences converged to within a fraction of a meV/atom in a few dozen energy calculations. For a concentrated equiatomic alloy similar precision requires roughly a hundred samples. The results suggest that the proposed methodology could provide a computationally tractable framework for calculating solid-liquid phase equilibria in concentrated alloys with DFT accuracy.

Angioletti-Uberti, Stefano; Asta, Mark; Finnis, Mike W.; Lee, P. D.

2008-10-01

31

Methods and systems for monitoring a solid-liquid interface  

SciTech Connect

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

32

A hybrid solid-liquid polymer photodiode for the bioenvironment  

NASA Astrophysics Data System (ADS)

We demonstrate that a prototypical semiconducting polymer, poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV) maintains unaltered its optoelectronic properties throughout the various steps for neural preparation. Films of MEH-PPV, after prolonged immersion in water or buffer solution, are characterized by linear and nonlinear optical spectroscopy. Based on this result, we introduce a hybrid solid-liquid photodiode based on MEH-PPV, in which we use culturing media as liquid, ionic cathodes. The hybrid device is proposed as an active interface between living tissue and conducting polymers for cell diagnostic and neural implants.

Antognazza, M. R.; Ghezzi, D.; Musitelli, D.; Garbugli, M.; Lanzani, G.

2009-06-01

33

Vibrational Coupling and Kapitza Resistance at a Solid-Liquid Interface  

NASA Astrophysics Data System (ADS)

The rapid development and application of nanotechnologies have promoted an increasing interest in research on heat transfer across the solid/liquid interface. In this study, molecular dynamics simulations are carried out to elucidate the effect of vibrational coupling between the solid and the liquid phases on the Kapitza thermal resistance. This is accomplished by altering the atomic mass and interatomic interaction strength in the solid phase (thus, the vibrational properties), while keeping the solid-liquid interfacial interaction unchanged. In this way, the Kapitza resistance can be altered with a constant work of adhesion between the solid and the liquid phases. The simulation results show that the overlap degree between the vibrational density of states profiles of the interfacial liquid layer and the outermost solid layer, which measures the degree of interfacial vibrational coupling, increases with larger atomic mass and weaker inter-atomic interaction in the solid phase. An inverse relation exists between the Kapitza resistance and the overlap degree of the vibrational density of states profiles. It means that the Kapitza resistance decreases with better interfacial vibrational coupling. The simulations show that the Kapitza resistance is not only affected by the interfacial bonding strength but also the vibrational coupling between the solid and the liquid atoms. The interfaces with better thermal transport efficiency should be the ones with stronger interfacial interaction and preferable vibrational coupling between solid and liquid phases.

Ge, Song; Chen, Min

2013-01-01

34

Three-dimensional simulation of a solid-liquid flow by the DEM-SPH method  

NASA Astrophysics Data System (ADS)

We develop a new Lagrangian model for solid-liquid flows involving free surfaces.The present model employs conservative forms and a compatible boundary model.We analyze the dynamic wave propagation in a solid-liquid dam-break flow.We simulate the quasi-steady solid-liquid flow in a rotating tank.Simulation results are in good agreement with experimental data for validation.

Sun, Xiaosong; Sakai, Mikio; Yamada, Yoshinori

2013-09-01

35

Reversible Phase Transformation at the Solid-Liquid Interface: STM Reveals.  

PubMed

Reversible supramolecular self-assemblies have attracted increasing attention in nanoscience and technology during the past few years due to their potential application in the extreme miniaturization of switches and other devices. The building blocks concerned can respond structurally, electronically, optically, and mechanically to external stimuli. Herein, we focus on the recent progress of the supramolecular self-assembly reversibly triggered by temperature, light, electric current, metal ions and protons at the solid-liquid interface. Following this general roadmap, supramolecular systems based on H-bonds, azobenzene derivatives, triple-decker complexes, and the guanine motif are successively discussed in this review. Notably, these reversible phase transformations can be probed by the scanning tunneling microscopy (STM) technique, which has been proven as an effective tool in surface science. PMID:23825034

Zhang, Xue-Mei; Zeng, Qing-Dao; Wang, Chen

2013-07-03

36

Mechanisms of reduced solute diffusivity at nanoconfined solid-liquid interface  

NASA Astrophysics Data System (ADS)

We report results from molecular simulations that reveal the causes of reduced diffusivity at solid-liquid interfaces in the presence of nanoscale confinement. The diffusion of a 2 M glucose solution was simulated inside a 10 nm silica channel together with the calculated thermodynamic properties of diffusion. A strong energy-entropy compensation mechanism was found at the interface with a free energy minimum of -0.6 kcal/mol. Using the Eyring equation the average jump length was reduced by 15% at interface. The complete loss of solute diffusivity at silica surface was explained by the substantial loss of the probability of productive displacements. The results suggested that glucose molecule diffusivity close to the surface might be related to a stiffer cage of the hydration shell, which affects the probability of cage breaking. These results help in understanding of diffusion mechanisms at interface and predicting mass transport in nanoconfinement for engineering and biomedical applications.

Mahadevan, T.; Kojic, M.; Ferrari, M.; Ziemys, A.

2013-06-01

37

Studying dissolution with a model integrating solid-liquid interface kinetics and diffusion kinetics.  

PubMed

A dissolution model that integrates the solid-liquid interface kinetics and the mass transport kinetics is introduced. Such a model reduces to the Noyes-Whitney equation under special conditions, but offers expanded range of applicability and flexibility fitting dissolution profiles when interfacial kinetics and interfacial concentration deviate from the assumptions implied in the Noyes-Whitney equation. General solutions to the integrated dissolution model derived for noninteractive solutes as well as for solutes participating in ionization equilibrium are discussed. Parameters defining the integrated dissolution model are explained conceptually along with practical ways for their determinations. Conditions under which the model exhibits supersaturation features are elaborated. Simulated dissolution profiles using the integrated dissolution model for published experimental data exhibiting supersaturation features are illustrated. PMID:23106346

Gao, Jeff Y

2012-11-26

38

Mass transfer in cellular material at solid–liquid contacting interface  

Microsoft Academic Search

The effective mass transfer (water and solute) and volume shrinkage were measured during solid–liquid contacting process for red beet material tissue under a wide range of process parameters. The mass transfer process of each component in the solid–liquid system is affected not only by operating parameters, but also by the matrix properties of cellular material. The main driving force for

John Shi; Marc Le Maguer

2003-01-01

39

Naviglio's Principle and Presentation of an Innovative Solid–Liquid Extraction Technology: Extractor Naviglio®  

Microsoft Academic Search

In this article, starting from a new solid–liquid extractive principle an innovative solid–liquid extractor is showed. Extractor Naviglio® works at room temperature and it does not need to heat the extractive system; this fact is important in the field of officinal plants and in many other cases when the objective of the extraction are the active principles or compounds sensible

Daniele Naviglio

2003-01-01

40

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

PubMed

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

Arai; Tsukimoto; Muto; Saka

2000-07-01

41

Influence of initial solid-liquid interface morphology on further microstructure evolution during directional solidification  

NASA Astrophysics Data System (ADS)

Preparation of the initial solid-liquid interface on which growth is started is a very critical step in directional solidification experiments. Dedicated experiments concerning preparation of the initial solid-liquid interface morphology and its influence on further directionally solidified microstructure were performed on Cu-20 wt% Sn peritectic alloy in a Bridgman-type furnace. To verify the morphology of the initial solid-liquid interface, steady-state directional dendritic growth was interrupted by thermal stabilization ranging from 0 to 1 h prior to quenching. With thermal stabilization duration increase, the solid-liquid interface morphology degenerated from dendritic to cellular and finally to planar. To verify the influence of the initial state on further solidification microstructure, directional solidification experiments were performed at a low pulling rate of 1 ?m/s with different initial solid-liquid interface morphologies. The initial state affects solute redistribution and formation of peritectic coupled growth structure in the subsequent directional solidification process.

Liu, Dongmei; Li, Xinzhong; Su, Yanqing; Guo, Jingjie; Luo, Liangshun; Fu, Hengzhi

2013-02-01

42

Indicateurs liés à la qualité de l'eau et comportements ; application aux lacs d'Annecy et du Bourget  

Microsoft Academic Search

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

François Bonnieux; Gérard Miclet; Pierre Rainelli

1977-01-01

43

Indicateurs liés à la qualité de l'eau et comportements. Application aux lacs d'Annecy et du Bourget  

Microsoft Academic Search

[fre] La recherche d'indicateurs d'environnement correspond à une approche certes descriptive, mais qui a le mérite de déboucher assez rapidement sur le plan pratique. Nous présentons les résultats d'une application au cas de deux lacs alpins : Annecy et le Bourget. Elle repose sur une mise en relation de paramètres de nature hydrobiologique et de données socio-économiques. . L'étude comparée

François Bonnieux; Gérard Miclet; Pierre Rainelli

1978-01-01

44

Final Report: Thermal Conductance of Solid-Liquid Interfaces  

SciTech Connect

Research supported by this grant has significantly advanced fundamental understanding of the thermal conductance of solid-liquid interfaces, and the thermal conductivity of nanofluids and nanoscale composite materials. • The thermal conductance of interfaces between carbon nanotubes and a surrounding matrix of organic molecules is exceptionally small and this small value of the interface conductance limits the enhancement in thermal conductivity that can be achieved by loading a fluid or a polymer with nanotubes. • The thermal conductance of interfaces between metal nanoparticles coated with hydrophilic surfactants and water is relatively high and surprisingly independent of the details of the chemical structure of the surfactant. • We extended our experimental methods to enable studies of planar interfaces between surfactant-coated metals and water where the chemical functionalization can be varied between strongly hydrophobic and strongly hydrophilic. The thermal conductance of hydrophobic interfaces establishes an upper-limit of 0.25 nm on the thickness of the vapor-layer that is often proposed to exist at hydrophobic interfaces. • Our high-precision measurements of fluid suspensions show that the thermal conductivity of fluids is not significantly enhanced by loading with a small volume fraction of spherical nanoparticles. These experimental results directly contradict some of the anomalous results in the recent literature and also rule-out proposed mechanisms for the enhanced thermal conductivity of nanofluids that are based on modification of the fluid thermal conductivity by the coupling of fluid motion and the Brownian motion of the nanoparticles.

Cahil, David, G.; Braun, Paul, V.

2006-05-31

45

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

2012-12-27

46

Determination of Solid-Liquid Equilibria Data for Mixtures of Heavy Hydrocarbons in a Light Solvent.  

National Technical Information Service (NTIS)

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 t...

F. V. Hanson J. V. Fletcher

2003-01-01

47

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

Microsoft Academic Search

The objective of this project is to develop a model for solid-liquid equilibria and a model for viscosities of the products of coal liquefaction processes. The same characterization procedure and representation by continuous distributions as used in previous work on vapor-liquid equilibria and excess enthalpies of coal liquids will be used. Models when fully developed win give the solid-liquid phase

Kabadi

1995-01-01

48

Tunable synergism/antagonism in a mixed nonionic/anionic surfactant layer at the solid/liquid interface.  

PubMed

The use of mixed surfactants for modification of solid surfaces is important for many applications, since beneficial synergism often occurs depending on the surfactant type and mixing conditions. Systematical information on the properties of surfactant mixtures at the solid/liquid interface can be helpful for optimizing the interactions between the surfactants and then their corresponding performance. In this work, a nonionic/anionic surfactant combination, n-dodecyl beta-d-maltoside (DM) and sodium dodecyl sulfonate (SDS), was selected for the study of adsorption on an oxide solid, alumina. Interestingly, the mixture of the two surfactants with opposite pH-dependence of adsorption on alumina exhibits some unique synergistic or antagonistic features that were found to be tunable in the region of pH 4-10. In addition, the DM/SDS molar ratio in the adsorbed layer was found to decrease with concentration in the saturated region at all the pH and mixing ratios tested. The decrease is attributed to the monomer concentration changes in solution due to the difference in surface activities of the two surfactants. The tunable features of this mixture at the solid/liquid interface provide a way to optimize the properties by changing the mixing conditions. This can be valuable in many applications, such as enhanced oil recovery, flotation, and solubilization. PMID:18324849

Lu, Shaohua; Somasundaran, Ponisseril

2008-03-07

49

Solid/liquid lubrication of ceramics at elevated temperatures  

SciTech Connect

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

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

1996-04-01

50

Combining molecular dynamics simulation and transition state theory to evaluate solid-liquid interfacial friction in carbon nanotube membranes  

NASA Astrophysics Data System (ADS)

A molecular dynamics (MD) methodology based on Eyring theory of reaction rates is proposed for investigating solid-liquid interfacial properties crucial to the development of many nanotechnology applications. The method involves the calculation of activation energy required for the flow process directly from the MD trajectory information. We have applied this methodology to study the behavior of water in hydrophobic confinement in carbon nanotubes (CNTs) and also between graphene sheets. In the case of confined water molecules in CNTs and between graphene sheets the degree of confinement and curvature effects were found to have more influence on the solid-liquid interfacial friction, with almost negligible friction below a certain characteristic dimension in both the cases. This behavior of confined and unconfined water molecules is explained on the basis of molecular interactions and subsequent changes in the activation energy. Analysis based on this method also revealed that a finite amount of friction does exist at the channel entry and exit region. This could limit the flow of liquid molecules through the nanochannels and hence needs to be taken into account in the design of nanofluidic devices.

Babu, Jeetu S.; Sathian, Sarith P.

2012-05-01

51

Step free energies at faceted solid-liquid interfaces from equilibrium molecular dynamics simulations  

NASA Astrophysics Data System (ADS)

In this work a method is proposed for computing step free energies for faceted solid-liquid interfaces based on atomistic simulations. The method is demonstrated in an application to (111) interfaces in elemental Si, modeled with the classical Stillinger-Weber potential. The approach makes use of an adiabatic trapping procedure, and involves simulations of systems with coexisting solid and liquid phases separated by faceted interfaces containing islands with different sizes, for which the corresponding equilibrium temperatures are computed. We demonstrate that the calculated coexistence temperature is strongly affected by the geometry of the interface. We find that island radius is inversely proportional to superheating, allowing us to compute the step free energy by fitting simulation data within the formalism of classical nucleation theory. The step free energy value is computed to be ?st = 0.103 +/- 0.005 × 10-10 J/m. The approach outlined in this work paves the way to the calculation of step free energies relevant to the solidification of faceted crystals from liquid mixtures, as encountered in nanowire growth by the vapor-liquid-solid mechanism and in alloy casting. The present work also shows that at low undercoolings the Stillinger-Weber interatomic potential for Si tends to crystallize in the wurtzite, rather than the diamond-cubic structure.

Frolov, T.; Asta, M.

2012-12-01

52

Step free energies at faceted solid-liquid interfaces from equilibrium molecular dynamics simulations.  

PubMed

In this work a method is proposed for computing step free energies for faceted solid-liquid interfaces based on atomistic simulations. The method is demonstrated in an application to (111) interfaces in elemental Si, modeled with the classical Stillinger-Weber potential. The approach makes use of an adiabatic trapping procedure, and involves simulations of systems with coexisting solid and liquid phases separated by faceted interfaces containing islands with different sizes, for which the corresponding equilibrium temperatures are computed. We demonstrate that the calculated coexistence temperature is strongly affected by the geometry of the interface. We find that island radius is inversely proportional to superheating, allowing us to compute the step free energy by fitting simulation data within the formalism of classical nucleation theory. The step free energy value is computed to be ?(st) = 0.103 ± 0.005 × 10(-10) J/m. The approach outlined in this work paves the way to the calculation of step free energies relevant to the solidification of faceted crystals from liquid mixtures, as encountered in nanowire growth by the vapor-liquid-solid mechanism and in alloy casting. The present work also shows that at low undercoolings the Stillinger-Weber interatomic potential for Si tends to crystallize in the wurtzite, rather than the diamond-cubic structure. PMID:23231218

Frolov, T; Asta, M

2012-12-01

53

Analysis of capacitive force acting on a cantilever tip at solid/liquid interfaces  

NASA Astrophysics Data System (ADS)

Dielectric properties of biomolecules or biomembranes are directly related to their structures and biological activities. Capacitance force microscopy based on the cantilever deflection detection is a useful scanning probe technique that can map local dielectric constant. Here we report measurements and analysis of the capacitive force acting on a cantilever tip at solid/liquid interfaces induced by application of an alternating voltage to explore the feasibility of the measurements of local dielectric constant by the voltage modulation technique in aqueous solutions. The results presented here suggest that the local dielectric constant measurements by the conventional voltage modulation technique are basically possible even in polar liquid media. However, the cantilever deflection is not only induced by the electrostatic force, but also by the surface stress, which does not include the local dielectric information. Moreover, since the voltage applied between the tip and sample are divided by the electric double layer and the bulk polar liquid, the capacitive force acting on the apex of the tip are strongly attenuated. For these reasons, the lateral resolution in the local dielectric constant measurements is expected to be deteriorated in polar liquid media depending on the magnitude of dielectric response. Finally, we present the criteria for local dielectric constant measurements with a high lateral resolution in polar liquid media.

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

2013-04-01

54

Modeling the solid-liquid phase transition in saturated triglycerides.  

PubMed

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 approximately 120 degrees 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 DeltaH. 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 DeltaH 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 DeltaH that was too small by a factor of approximately 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 degrees C < or = T < or = 90 degrees 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. PMID:20136317

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

2010-02-01

55

Measurement of Solid-Liquid Interfacial Energy and Its Anisotropy of Succinonitrile  

NASA Astrophysics Data System (ADS)

The two-dimensional equilibrated grain boundary grooves (GBG) of succinonitrile (SCN) was directly observed by using a temperature gradient stage with high temperature stability to measure the solid-liquid interfacial free energy and its anisotropic factor. Based on the numerical solution of Gibbs-Thomson equation and parameter optimization method, the liquid-solid interfacial free energy and its anisotropy of SCN were extracted from the digitised GBG shapes respectively. The results show that the average solid-liquid interfacial free energy is ?0 = 9.66×10-3J·m-2, and the average anisotropic factor is epsilon4 = 0.85%.

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

2012-01-01

56

Adsorption of Gold Nanoparticles from a Crowded Solution on Solid/Liquid Interface  

NASA Astrophysics Data System (ADS)

Adsorption of nanoparticles at solid-liquid interface is of great importance in the field of colloidal science and biophysics. Protein adsorption is one of the most significant processes and can be mimicked by colloidal systems. We will present results of our studies of the kinetics of adsorption of gold nanoparticles from a crowded polyvinyl alcohol (PVA) polymer solution on a solid/liquid interface using phase-modulated ellipsometry and Fluctuation Correlation Spectroscopy (FCS). The experimental system mimics many biological processes, where the adsorption of particles or proteins takes place in the presence of many other components.

Alam, Sharmine; Kohli, Indermeet; Patel, Bhavdeep; Mukhopadhyay, Ashis

2012-10-01

57

Nanoparticle adsorption from a crowded solution at a solid/liquid interface  

NASA Astrophysics Data System (ADS)

Adsorption of nanoparticles at solid-liquid interface is of great importance in the field of colloidal science and biophysics. Protein adsorption is one of the most significant processes and can be mimicked by colloidal systems. We will present results of our studies of the kinetics of adsorption of gold nanoparticles from a crowded polyvinyl alcohol (PVA) polymer solution on a solid/liquid interface using phase-modulated ellipsometry. The experimental system mimics many biological processes, where the adsorption of particles or proteins takes place in the presence of many other components.

Kohli, Indermeet; Alam, Sharmine; Mukhopadhyay, Ashis

2012-02-01

58

Solid-liquid phase diagrams of binary aromatic hydrocarbon mixtures from calorimetric studies  

SciTech Connect

The authors describe solid-liquid phase diagrams of binary mixtures of aromatic hydrocarbons obtained from calorimetric studies. The sample of the binary solid mixture is heated at a constant rate until the solid is completely melted. During that process, the heat flux needed is monitored. By examination of the curves of the heat flux versus temperature, the solid-liquid phase diagrams can be constructed. Three binary systems (fluorene-dibenzofuran, dibenzothiophene-dibenzofuran, fluorene-dibenzothiophene) have been studied. It turns out that the fluorene-dibenzofuran system forms a solid solution at any composition, while dibenzothiphene-dibenzofuran and fluorene-dibenzothiophene systems have immiscibility gaps in the solid phases.

Sediawan, W.B.; Gupta, S.; McLaughlin, E. (Louisiana State Univ., Baton Rouge, LA (USA). Dept. of Chemical Engineering)

1989-04-01

59

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

NASA Astrophysics Data System (ADS)

We investigate the deformation induced by water pressure variations in hydrologically active natural fractures, and recorded by tiltmeters and strainmeters. The deformation associated with a single fracture is derived using finite-element modelling (FEM). A range in fracture geometries is explored, first to highlight the sensitivity of each geometrical parameter to the deformation, and secondly to allow transfer to observation sites. Water level variations in the fracture are then derived from a hydrological model, driven by observed rainfall, and calibrated on fracture water flow measurements. The modelling results are explicitly applied to constrain the local hydrological contribution to observations with the 100-m-long hydrostatic tiltmeter installed at Sainte-Croix-aux-Mines (France). Our study shows that well-founded physical modelling of local hydrological effect allows a substantial correction of records in observatories.

Longuevergne, Laurent; Florsch, Nicolas; Boudin, Frédéric; Oudin, Ludovic; Camerlynck, Christian

2009-08-01

60

Middle School Chemistry Unit | Chapter 1 | MatterâSolids, Liquids, and Gases  

NSDL National Science Digital Library

Students are introduced to the idea that matter is composed of atoms and molecules that are attracted to each other and in constant motion. Students explore the attractions and motion of atoms and molecules as they experiment with and observe the heating and cooling of a solid, liquid, and gas.

Society, Adam B.

2011-03-24

61

On the Numerical Solution of Continuum Mixture Model Equations Describing Binary Solid-Liquid Phase Change  

Microsoft Academic Search

This paper deals with some numerical aspects of the solution of continuum mixture model equations for analyzing solid-liquid phase change problems involving binary materials. It is found that the procedure used for iteratively updating the solid fraction with temperature has an important bearing on the convergence behavior of the overall method; here, based on our previous work, we present one

C. Prakash; V. Voller

1989-01-01

62

Enhanced mass transfer during solid–liquid extraction of gamma-irradiated red beetroot  

Microsoft Academic Search

The exposure to gamma-irradiation pretreatment increases cell wall permeabilization, resulting in loss of turgor pressure, which led to the increase of extractability of betanin from red beetroot. The degree of extraction of betanin was investigated using gamma irradiation as a pretreatment prior to the solid–liquid extraction process and compared with control beetroot samples. The beetroot subjected to different doses of

Chetan A. Nayak; S. Chethana; N. K. Rastogi; K. S. M. S. Raghavarao

2006-01-01

63

A Study on Optimal Sizing of Pipeline Transporting Equi-sized Particulate Solid-Liquid Mixture  

Microsoft Academic Search

Pipelines transporting solid-liquid mixtures are of practical interest to the oil and pipe industry throughout the world. Such pipelines are known as slurry pipelines where the solid medium of the flow is commonly known as slurry. The optimal designing of such pipelines is of commercial interests for their widespread acceptance. A methodology has been evolved for the optimal sizing of

Taimoor Asim; Rakesh Mishra; Suman Pradhan; Kuldip Ubbi

2012-01-01

64

The impact of algal properties and pre-oxidation on solid–liquid separation of algae  

Microsoft Academic Search

Algae are traditionally classified according to biological descriptors which do not give information on surface characteristics that are important with respect to removal by water treatment processes. This review examines the character of freshwater algal populations from a water treatment perspective and evaluates the impact of their varying properties and the use of pre-oxidation on their removal by solid–liquid separation

Rita Henderson; Simon A. Parsons; Bruce Jefferson

2008-01-01

65

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...

66

Different gastric, pancreatic, and biliary responses to solid-liquid or homogenized meals  

Microsoft Academic Search

We have compared responses to an ordinary solid-liquid (S) meal and to a homogenized (H) meal of identical composition (sirloin steak, bread, butter, ice cream with chocolate syrup, and water) by measuring simultaneously postprandial gastric, pancreatic, and biliary functions by marker-perfusion techniques. Responses to each (S or H) meals differed strikingly both in magnitude and pattern. S meals elicited a

Juan-R. Malagelada; Vay L. W. Go; W. H. J. Summerskill

1979-01-01

67

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

68

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

69

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

70

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

71

Morphological evolution of the solid-liquid interface near grain boundaries during directional solidification  

NASA Astrophysics Data System (ADS)

Morphological evolution of the solid-liquid interface near grain boundaries has been studied during directional solidification of succinonitrile-based transparent alloys (SCN-0.9wt%DCB). Experimental results show that the grain boundary provides the starting point of morphological instability of the solid-liquid interface. The initial perturbation near the grain boundary is significantly larger than other perturbations on the interface. The initial shape of the interface and the competition between the thermal direction and preferred crystalline orientations determine the subsequent growth pattern selections. The temporal variations of the curvature radius of cell/ridge tips near the grain boundary have also been studied when the instability occurs. This process is divided into three parts. As the pulling velocity increases, dendrites at the grain boundary grow in two different directions to form a bicrystal microstructure. Side branches on either side of the dendrite exhibit different growth patterns.

Xing, Hui; Wang, Caifang; Wang, Jianyuan; Chen, Changle

2011-12-01

72

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

SciTech Connect

The existence of a wetting transition for helium adsorbed on cesium provides an experimental opportunity to investigate the solid-liquid surface tension. We have extracted the temperature dependence of the solid-liquid surface tension at the {sup 4}He/Cs interface from our earlier measurements of the wetting temperature of pure {sup 4}He on thin layers of cesium overlaying gold. More recently we have measured the wetting temperature as a function of the {sup 3}He concentration for {sup 3}He-{sup 4}He mixtures. An analysis of these experiments paralleling Andreev`s investigation of the free surface reveals {sup 3}He bound states at the helium/cesium interface.

Rutledge, J.E.; Ross, D.; Taborek, P. [Univ. of California, Irvine, CA (United States)

1995-10-01

73

A hybrid anaerobic solid-liquid bioreactor for food waste digestion  

Microsoft Academic Search

A hybrid anaerobic solid-liquid (HASL) bioreactor is an enhanced two-phase anaerobic system, that consists of a solid waste reactor as the acidification reactor and a wastewater reactor, i.e. an upflow anaerobic sludge blanket (UASB) reactor as the methanogenic reactor. Food waste digestion in HASL bioreactors with pre-acidification and HASL operation stages was investigated in two separate runs. After 8 days

Xu Hai-Lou; Wang Jing-Yuan; Tay Joo-Hwa

2002-01-01

74

Solid-liquid separation of oxidized americium from fission product lanthanides  

Microsoft Academic Search

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

T C Shehee; L R Martin; K L Nash

2010-01-01

75

MODELING THE EXTRACTION OF VALUABLE SUBSTANCES FROM NATURAL PLANTS USING SOLID–LIQUID EXTRACTION  

Microsoft Academic Search

A mathematical model for modeling solid–liquid extraction from plants was developed. Two extraction systems were investigated: tamarind seed coat-ethanol and green tea-ethanol. All models were fitted to experimental data and the results were compared. It was found that the model neglecting diffusion transport gave a better prediction than the theoretical model, however, the kinetic coefficient of the process cannot be

Anurak Winitsorn; Peter L. Douglas; Supaporn Douglas; Suwassa Pongampai; Witaya Teppaitoon

2008-01-01

76

Electron Beam Design and Calibration for the Solid\\/Liquid Lithium Divertor Experiment  

Microsoft Academic Search

An electron beam has been developed as part of the Solid\\/Liquid Lithium Divertor Experiment (SLiDE) at the University of Illinois at Urbana-Champaign. The purpose of the SLiDE apparatus is to examine the motion of liquid lithium under fusion relevant heat loads and magnetic fields. To mimic the heat fluxes present in the divertor of a fusion machine, a linear sheet

Michael Jaworski; R. Flauta; T. K. Gray; J. Kim; C. Y. Lau; M. B. Lee; M. J. Neumann; V. Surla; D. N. Ruzic

2008-01-01

77

Adsorption of 1-alkyl-4-methylpyridinium salts at solid-liquid and water-air interfaces  

Microsoft Academic Search

Determinations of the adsorption at both solid-liquid and water-air interfaces of 1-alkyl-4-methylpyridinium salts have been performed.At the water-air interface, measurements of the surface tension as a function of the bulk concentration of 1-dodecyl-4-methylpyridinium chloride were performed. Mathematical treatment of the resulting isotherm allowed the size of the adsorbed molecule and the CMC to be obtained.The solid adsorbent was a titanium

S. Ardizzone; C. L. Bianchi; P. Drago; D. Mozzanica; P. Quagliotto; P. Savarino; G. Viscardi

1996-01-01

78

Controlled growth of silicon nanowires synthesized via solid–liquid–solid mechanism  

Microsoft Academic Search

The growth of silicon nanowires using solid–liquid–solid method is described. In this method, silicon substrates coated with a thin layer of gold were heat treated in nitrogen ambient. Gold particles started to diffuse into the silicon substrate and Au–Si alloy formed at the interface. The alloy would have molten to form liquid droplets on the substrate when temperature increases above

Y. Y. Wong; M. Yahaya; M. Mat Salleh; B. Yeop Majlis

2005-01-01

79

Measurement of solid liquid interfacial energy in the pyrene succinonitrile monotectic system  

Microsoft Academic Search

The equilibrated grain boundary groove shapes for solid pyrene (PY) in equilibrium with the PY succinonitrile (SCN) monotectic liquid were directly observed. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficient and solid-liquid interfacial energy for solid PY in equilibrium with the PY SCN monotectic liquid have been determined to be (8.72 ± 0.87) × 10-8 K m and

S. Akbulut; Y. Ocak; U. Böyük; M. Erol; K. Keslioglu; N. Marasli

2006-01-01

80

Solid–liquid interfacial energy for solid succinonitrile in equilibrium with succinonitrile dichlorobenzene eutectic liquid  

Microsoft Academic Search

The equilibrated grain boundary groove shapes for solid succinonitrile (SCN) in equilibrium with the succinonitrile (SCN) dichlorobenzene (DCB) eutectic liquid were directly observed. From the observed grain boundary groove shapes, the Gibbs–Thomson coefficient and solid–liquid interfacial energy for solid SCN in equilibrium with the SCN DCB eutectic liquid have been determined to be (5.43±0.27)×10?8Km and (7.95±0.80)×10?3Jm?2 with present numerical method

Y. Ocak; S. Akbulut; U. Böyük; M. Erol; K. Ke?lio?lu; N. Mara?l?

2006-01-01

81

Solid suspension and gas dispersion in gas-solid-liquid agitated systems  

Microsoft Academic Search

The aim of the research work was to investigate the effect of superficial gas velocity and solids concentration on the critical\\u000a agitator speed, gas hold-up and averaged residence time of gas bubbles in an agitated gas-solid-liquid system. Experimental\\u000a studies were conducted in a vessel of the inner diameter of 0.634 m. Different high-speed impellers: Rushton and Smith turbines,\\u000a A 315

Anna Kie?bus-R?pa?a; Joanna Karcz

2010-01-01

82

A new continuous device to perform S-L-G photocatalytic studies. [Solid-Liquid-Gas  

SciTech Connect

A new experimental device to carry out solid-liquid-gas photocatalytic studies is presented. It can operate as a continuous system with respect to both the gas and the liquid phase. The solid photocatalyst is held inside the system and is continuously recycled through it to enable the separation of the spent liquid. Steady values of liquid and gas composition as well as temperature and fluidodynamic variables can be set and controlled.

Aguado, M.A.; Gimenez, J.; Simarro, R.; Cervera-March, S. (Univ. de Barcelona (Spain))

1992-07-01

83

Prediction and correlation of triglyceride–solvent solid–liquid equilibria with activity coefficient models  

Microsoft Academic Search

Solid–liquid equilibria (SLE) for solvent–triacylglyceride (TAG) systems are studied with activity coefficient models. Systems consisted of 29 data sets of C10:0 to C18:0 saturated triglycerides in nine solvents, benzene, acetone, carbon disulfide, carbon tetrachloride, chloroform, diethyl ether, ethanol, ethyl acetate, and n-hexane making up 562 data points. Eighteen activity coefficient models containing 0–2 fitting parameters were evaluated including a number

R. L. Smith; G. M. Acosta; K. Arai

1998-01-01

84

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

85

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

86

HEAT TRANSFER OF SOLID–LIQUID PHASECHANGE MATERIAL SUSPENSIONS IN CIRCULAR PIPES: EFFECTS OF WALL CONDUCTION  

Microsoft Academic Search

This article considers the problem of conjugate heat transfer in circular pipes with finite heated length to examine the effects of wall conduction on the heat transfer characteristics of solid–liquid phase-change material suspension flow. A mixture continuum approach is adopted in the formulation of the energy equation, with an approximate enthalpy model describing the phase-change process in the phase-change material

C. J. Ho; J. F. Lin; S. Y. Chiu

2004-01-01

87

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

Microsoft Academic Search

The solid-liquid phase diagrams have been determined for six binary and one ternary system composed of m-cresol, p-cresol, piperazine, and dibutyl ether. The results indicate the existence of 1-2 complexes in the p-cresol + m-cresol, piperazine + m-cresol, and piperazine + p-cresol systems. The observed melting points were correlated with composition by an empirical equation. Dissociation extractive crystallization is one

Mingjer Lee; Peichi Chi

1993-01-01

88

Effect of carbonitride precipitates on the solid/liquid erosion behaviour of hardfacing alloy  

NASA Astrophysics Data System (ADS)

The present work reports the effect of carbonitride precipitates on the solid/liquid erosion behaviour of hardfacing alloy. Two kinds of Fe-Cr13-C hardfacing alloy (with and without nitrogen) were deposited on a carbon steel substrate. The microstructure of the hardfacing alloy was studied. Solid/liquid erosion tests were carried out with quartz sand particles under impact angles of 30°, impact velocity of 25 m/s for 45 min to explore the erosion behaviour of the hardfacing alloy. It is found that the erosion damages of hardfacing alloy were microcutting and impinging caused by the erosion of sand particles. Fine carbonitride precipitates can obviously refine the microstructure and make a dispersion strengthening effect on the matrix, leading to the enhancement of hardness of hardfacing alloy. In addition, lots of carbonitride precipitates can effectively protect the surface of hardfacing alloy against wearing of erosion sand particles. So the erosion resistance of hardfacing alloy could be improved significantly owing to the strengthening and protecting effect of carbonitride precipitates, and solid/liquid erosion mechanisms were found to be microcutting and impinging with shallow grooves, fine pits and tiny lips.

Yang, Ke; Yang, Qin; Bao, Yefeng

2013-11-01

89

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

NASA Astrophysics Data System (ADS)

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

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

2011-09-01

90

Density, viscosity, refractive index and electrical conductivity of saturated solutions of the lithium hydroxide + ethanol + water system at 298.15 K, and thermodynamic description of the solid–liquid equilibrium  

Microsoft Academic Search

The water+ethanol+lithium hydroxide system has a great potential for implementing drowning-out crystallization processes in industrial lithium hydroxide production. For this reason, a knowledge of both the most relevant physical properties as well as the thermodynamic description of the solid–liquid equilibrium of this system is of great interest for designing industrial applications. In this paper, the density, viscosity, refractive index and

Maria Elisa Taboada; Héctor R. Galleguillos; Teófilo A. Graber; Javier Álvarez-Benedí

2005-01-01

91

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

92

Structural Evolution of Silicon Oxide Nanowires via Head-Growth Solid-Liquid-Solid Process  

NASA Astrophysics Data System (ADS)

In this paper, we propose a growth mechanism for silicon oxide nanowires (SiONWs) as a unique solid-liquid-solid process. SiONWs were synthesized in a furnace at 1000 °C and cooled at a high rate. Nickel and gold were introduced as catalysts to dissolve and precipitate the silicon oxide originally prepared by wet oxidation. The ratio of nickel to gold determined the precipitation rate and different “octopus-like” structures were formed. At a specific cooling rate, composition and amount of a catalyst, aligned silicon oxide nanowires with unattached ends were obtained.

Hsu, Cheng-Hang; Chan, Shih-Yu; Chen, Chia-Fu

2007-11-01

93

Solid–liquid interface energies in the succinonitrile and succinonitrile–carbon tetrabromide eutectic system  

Microsoft Academic Search

The equilibrated grain boundary groove shapes for the commercial purity succinonitrile (SCN) and succinonitrile–carbon tetrabromide (CTB) eutectic system were directly observed. From the observed grain boundary groove shapes, the Gibbs–Thomson coefficients for the solid SCN–liquid SCN and solid SCN–liquid SCN CTB have been determined to be (5.43±0.27)×10?8Km and (5.56±0.28)×10?8Km, respectively, with numerical method. The solid–liquid interface energies for the solid

N. Marasli; K. Ke?l?o?lu; B. Arslan

2003-01-01

94

Crystalline order of polymer nanoparticles over large areas at solid/liquid interfaces  

NASA Astrophysics Data System (ADS)

We report on the formation of large two-dimensional domains (about 20 cm2) of oriented and ordered structures of polystyrene particles dispersed in water at a solid/liquid interface. Gentle flow of the dispersed sample into the holder at a shear strain rate of about 0.1 s-1 caused particles at the air/latex meniscus to self-assemble in a regular structure on both solid silica or alumina surfaces. Scattering experiments show that the particle separation at the surface was the same as in the bulk and determined by repulsion arising from the charges on the particles. Close-packed planes formed parallel to the interface.

Hellsing, M. S.; Kapaklis, V.; Rennie, A. R.; Hughes, A. V.; Porcar, L.

2012-05-01

95

A flexible, highly stable electrochemical scanning probe microscope for nanoscale studies at the solid-liquid interface  

NASA Astrophysics Data System (ADS)

This work describes the design, fabrication, and application of an ultrastable scanning probe microscope for nanoscale studies at the solid-liquid interface, specifically in electrolyte environments. Quantification of system noise limits in the tunneling mode, mechanical drift rates, and lowest mechanical resonance provided values of <=10 pA/Hz1/2, 2 nm/min (XY) and 0.15 nm/min (Z), and 7.9 kHz, respectively. Measurement of the closed-loop transfer function in the tunneling condition demonstrated linear feedback responses up to 4.2 and 2.5 kHz in ambient and electrochemical conditions. Atomic and molecular resolution imagings have been achieved in ambient, in situ, and electrochemical imaging environments at scan rates up to 80 lines/s. A modular design approach has produced a highly flexible microscope capable of imaging and spectroscopy in tunneling, tapping force [amplitude modulation atomic force microscopy (AFM)], and noncontact force (frequency modulation-AFM) modes.

Stieg, A. Z.; Rasool, H. I.; Gimzewski, J. K.

2008-10-01

96

Usure induite par vibrations sous écoulement : le cas des grappes de commande des réacteurs a eau pressurisée. Des études théoriques aux applications industrielles  

Microsoft Academic Search

Wear under flow induced vibrations: rod cluster control assemblies in pressurized water reactors. From theoretical studies to industrial applications. Several internal components in pressurized water reactors (PWR), especially the rod cluster control assemblies, are damaged by wear under flow induced vibrations. In order to solve this problem, an important R&D program has been launched by EDF and its partners. To

Marc Zbinden; Marta Dragon-Louiset

2000-01-01

97

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

98

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

NASA Astrophysics Data System (ADS)

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

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

2005-03-01

99

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

NASA Astrophysics Data System (ADS)

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

Voïtchovsky, Kislon

2013-08-01

100

Different gastric, pancreatic, and biliary responses to solid-liquid or homogenized meals.  

PubMed

We have compared responses to an ordinary solid-liquid (S) meal and to a homogenized (H) meal of identical composition (sirloin steak, bread, butter, ice cream with chocolate syrup, and water) by measuring simultaneously postprandial gastric, pancreatic, and biliary functions by marker-perfusion techniques. Responses to each (S or H) meals differed strikingly both in magnitude and pattern. S meals elicited a stronger early gastric secretory response (acid, pepsin, and volume) which compensated for faster initial emptying and resulted in higher gastric acidity and volume than after H meals. Further, nutrients ingested with S meals were emptied at a slower rate than H (as evidenced by a more gradual decline in intragastric buffer and osmolality, as well as time required for complete emptying of the meal). This, in turn, prolonged pancreatic and biliary responses since stimulation of these organs continued for as long as meal was delivered into the duodenum. However, early biliary outputs (gallbladder response) were less after S than H, probably because nutrients entered the duodenum more slowly and were initially diluted by rapidly emptying water. The physical characteristics of each meal (encompassing appearance, taste, and form of ingestion) probably accounted for early differences in digestive responses. Later, interactions between gastric (motor and secretory), pancreatic, and biliary functions played a major role. Our findings suggest that gastric, pancreatic, and biliary responses to liquid test meals introduced into the stomach may differ substantially from the presumably more physiological response to ordinary solid-liquid meals. PMID:371939

Malagelada, J R; Go, V L; Summerskill, W H

1979-02-01

101

Convective influence on the stability of a cylindrical solid-liquid interface  

NASA Astrophysics Data System (ADS)

Experiments in which a long vertical, heated wire is surrounded by concentric annuli of a melt and its crystalline solid show that the convection state changes from a stable unicell surrounded by a stationary cylindrical solid-liquid interface, to a complex time-dependent flow surrounded by a rotating, helical solid-liquid interface. This transition occurs at a Grashof number of approximately 150, which is an order of magnitude less than the critical Grashof number calculated for a liquid annulus surrounded by rigid walls. A linear stability analysis has been carried out for an infinitely tall vertical annulus. When the deformable nature of the crystal-melt interface is taken into account in the boundary conditions, two new modes of instability arise. The most dangerous mode is asymmetrical and corresponds to helical waves travelling vertically upwards. The critical Grashof number and the scaling properties of the eigenstate agree with experiments. The results clearly demonstrate the coupling of convection with crystal-melt interfacial instabilities.

Fang, Q. T.; Glicksman, M. E.; Coriell, S. R.; McFadden, G. B.; Boisvert, R. F.

1985-02-01

102

Atomistic simulation of CdTe solid-liquid coexistence equilibria  

SciTech Connect

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

Henager, Charles H.; Morris, James R.

2009-12-07

103

Solid-liquid phase equilibria of binary and ternary mixtures of benzene and polynuclear aromatic compounds  

SciTech Connect

Separation of organic close-boiling or close-melting components from a mixture is a challenging task in some chemical engineering processes, such as crystallization and extraction. With the present trend in the petroleum industry toward heavier feedstocks and coal-derived liquids, there is a strong need for expansion of the small database of thermodynamic data on heavier compounds that presently exists. Solid-liquid equilibrium phase diagrams for three binary mixtures of benzene with polynuclear aromatic compounds (fluorene, dibenzofuran, and dibenzothiophene) have been measured by a dynamic method in the temperature range from 0 to 80C. These binary data plus previously published data derived from calorimetric studies were used to determine experimental activity coefficients and interaction parameters using the Wilson and UNIQUAC models. The resulting set of interaction parameters gave a good representation of the experimental binary data and ternary data at 50C, but were not generally satisfactory for predicting solid-liquid equilibrium in ternary systems at lower temperatures.

Domanska, U.; Groves, F.R. Jr.; McLaughlin, E. (Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Chemical Engineering)

1993-01-01

104

Solid-liquid surface free energy of Lennard-Jones liquid on smooth and rough surfaces computed by molecular dynamics using the phantom-wall method  

Microsoft Academic Search

Different model Lennard-Jones solid-liquid interfaces have been considered. In the systems, either the interaction strength between solid and liquid was varied, or the topography of the solid surface was modified. In all situations, the solid-liquid interfacial free energy variations with respect to a reference solid-liquid interface were quantified by means of a thermodynamic integration method [F. Leroy et al., Macromol.

Fre´de´ric Leroy; Florian Müller-Plathe

2010-01-01

105

Solid-liquid-vapor metal-catalyzed etching of lateral and vertical nanopores  

NASA Astrophysics Data System (ADS)

Etching is an essential tool for the creation of nanostructures, where patterned metal structures can be used as masks. Here, we investigate HCl gas etching of InP substrates decorated with Au nanoparticles, and find that the etch rate is strongly increased at the Au-InP interfaces. The {111}A facets of the InP are preferentially etched. The metal nanoparticles follow in the etch direction, thereby creating nanopores. The size and position of the pores is controlled by the Au nanoparticles, and we measure nanopores as thin as 20 nm with an aspect ratio of 25:1. The direction of the nanopores is influenced by the temperature and the substrate orientation, which we use to demonstrate lateral, vertical and inclined nanopores. We explain the process by a solid-liquid-vapor model, in which the liquid metal particle catalyzes the dissolution of the solid InP.

Wallentin, Jesper; Deppert, Knut; Borgström, Magnus T.

2013-10-01

106

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

107

Calculation of solid-liquid interfacial free energy: a classical nucleation theory based approach.  

PubMed

We present a simple approach to calculate the solid-liquid interfacial free energy. This new method is based on the classical nucleation theory. Using the molecular dynamics simulation, we employ spherical crystal nuclei embedded in the supercooled liquids to create an ideal model of a homogeneous nucleation. The interfacial free energy is extracted by fitting the relation between the critical nucleus size and the reciprocal of the critical undercooling temperature. The orientationally averaged interfacial free energy is found to be 0.302+/-0.002 (in standard LJ unit). The temperature dependence of the interfacial free energy is also obtained in this work. We find that the interfacial free energy increases slightly with increasing temperature. The positive temperature coefficient of the interfacial free energy is in qualitative agreement with Spaepen's analysis [Solid State Phys. 47, FS181 (1994)] and Turnbull's empirical estimation [J. Appl. Phys. 21, 1022 (1950)]. PMID:16599718

Bai, Xian-Ming; Li, Mo

2006-03-28

108

Solid-liquid-vapor metal-catalyzed etching of lateral and vertical nanopores.  

PubMed

Etching is an essential tool for the creation of nanostructures, where patterned metal structures can be used as masks. Here, we investigate HCl gas etching of InP substrates decorated with Au nanoparticles, and find that the etch rate is strongly increased at the Au-InP interfaces. The {111}A facets of the InP are preferentially etched. The metal nanoparticles follow in the etch direction, thereby creating nanopores. The size and position of the pores is controlled by the Au nanoparticles, and we measure nanopores as thin as 20 nm with an aspect ratio of 25:1. The direction of the nanopores is influenced by the temperature and the substrate orientation, which we use to demonstrate lateral, vertical and inclined nanopores. We explain the process by a solid-liquid-vapor model, in which the liquid metal particle catalyzes the dissolution of the solid InP. PMID:24060650

Wallentin, Jesper; Deppert, Knut; Borgström, Magnus T

2013-09-24

109

Measurement of solid liquid interfacial energy in the pyrene succinonitrile monotectic system  

NASA Astrophysics Data System (ADS)

The equilibrated grain boundary groove shapes for solid pyrene (PY) in equilibrium with the PY succinonitrile (SCN) monotectic liquid were directly observed. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficient and solid-liquid interfacial energy for solid PY in equilibrium with the PY SCN monotectic liquid have been determined to be (8.72 ± 0.87) × 10-8 K m and (21.9 ± 3.28) × 10-3 J m-2 with the present numerical method and Gibbs-Thomson equation, respectively. The grain boundary energy of the solid PY phase has been determined to be (42.84 ± 7.28) × 10-3 J m-2 from the observed grain boundary groove shapes. Thermal conductivities of solid and liquid phases for PY-2.5 mol% SCN alloy and pure PY have also been measured.

Akbulut, S.; Ocak, Y.; Böyük, U.; Erol, M.; Keslioglu, K.; Marasli, N.

2006-09-01

110

Measurement of solid-liquid interfacial energy in the pyrene succinonitrile monotectic system.  

PubMed

The equilibrated grain boundary groove shapes for solid pyrene (PY) in equilibrium with the PY succinonitrile (SCN) monotectic liquid were directly observed. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficient and solid-liquid interfacial energy for solid PY in equilibrium with the PY SCN monotectic liquid have been determined to be (8.72 ± 0.87) × 10(-8) K m and (21.9 ± 3.28) × 10(-3) J m(-2) with the present numerical method and Gibbs-Thomson equation, respectively. The grain boundary energy of the solid PY phase has been determined to be (42.84 ± 7.28) × 10(-3) J m(-2) from the observed grain boundary groove shapes. Thermal conductivities of solid and liquid phases for PY-2.5 mol% SCN alloy and pure PY have also been measured. PMID:21690896

Akbulut, S; Ocak, Y; Böyük, U; Erol, M; Ke?lio?lu, K; Mara?li, N

2006-08-24

111

Surface Specularity as AN Indicator of Shock-Induced Solid-Liquid Phase Transitions in Tin  

NASA Astrophysics Data System (ADS)

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 usually occurs at pressures high enough to melt the free surface. Unlike many other potential material phase-sensitive diagnostics (e.g., reflectometery, 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.

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

2007-12-01

112

Surface Specularity as an Indicator of Shock-Induced Solid-Liquid Phase Transitions  

NASA Astrophysics Data System (ADS)

When highly polished metal surfaces melt upon release after shock loading, they exhibit a number of features that suggest that 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 velocimetric measurements typically observed above pressures high enough to melt the free-surface. Unlike many other potential material phase-sensitive diagnostics (e.g., reflectometery, conductivity), changes in the specularity of reflection provide a dramatic, sensitive indicator of the solid-liquid phase transition. Data will be presented from multiple diagnostics that support the hypothesis that specularity changes indicate melt. These diagnostics include shadowgraphy, infrared imagery, high-magnification surface images, interferometric velocimetry, and most recently scattering angle measurements.

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

2007-06-01

113

Microstructural effects on distortion and solid-liquid segregation during liquid phase sintering under microgravity conditions  

NASA Astrophysics Data System (ADS)

Tungsten heavy alloys with compositions ranging from 78 to 98 wt pct tungsten were liquid phase sintered at 1507 °C under microgravity conditions for 120 minutes. The sintered microstructures were quantitatively measured for solid volume fraction, grain size, connectivity, and contiguity. Links between these microstructural parameters were analyzed and compared to previously derived empirical equations. The macrostructures of the samples were also quantified and correlated to the underlying microstructures. Critical values of solid volume fraction, contiguity, and connectivity required for free-standing structural rigidity were defined for various degrees of bond rigidity as represented by the dihedral angle. The results are used to predict the degree of solid-liquid segregation due to density differences between the solid and the liquid.

Johnson, John L.; Upadhyaya, A.; German, Randall M.

1998-08-01

114

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

115

Surface Specularity as an Indicator of Shock-Induced Solid-Liquid Phase Transitions  

SciTech Connect

When highly polished metal surfaces melt upon release after shock loading, they exhibit a number of features that suggest that 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 velocimetric measurements typically observed above pressures high enough to melt the free-surface. Unlike many other potential material phase-sensitive diagnostics (e.g., reflectometery, conductivity), changes in the specularity of reflection provide a dramatic, sensitive indicator of the solid-liquid phase transition. Data will be presented from multiple diagnostics that support the hypothesis that specularity changes indicate melt. These diagnostics include shadowgraphy, infrared imagery, high-magnification surface images, interferometric velocimetry, and most recently scattering angle measurements.

Gerald Stevens, Stephen Lutz, William Turley, Lynn Veeser

2007-06-29

116

Dynamic analysis of piezoelectric-solid-liquid coupled system of micro nebulizer  

NASA Astrophysics Data System (ADS)

Piezoelectric micro nebulizer is a typical piezoelectric-solid-liquid coupling problem. A 2D FEM model was presented for this system. Numerical results show that when the piezoelectric actuator is vibrated, nozzle film also is generated vibration, and the phase relationship occurs to them, and the operation at the second resonance frequency is more desirable than others. A good agreement between experimental results and theoretical results confirmed the validity of the theoretical model we developed. Therefore, the design of micro nebulizer to consider only the amplitude of piezoelectric vibration is not comprehensive, we must also consider the nozzle film vibration, as well as the phase between the back film and the nozzle film, and this can provide guidance for the optimal design of micro nebulizer.

Yang, Ming-Wei; Zhou, Zhao-Ying

2008-12-01

117

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

NASA Astrophysics Data System (ADS)

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

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

2011-08-01

118

Solid-liquid equilibria for binary mixtures composed of acenaphthene, dibenzofuran, fluorene, phenanthrene, and diphenylmethane  

SciTech Connect

The liquidus lines were determined with a solid-disappearance method for binary mixtures composed of acenaphthene, dibenzofuran, fluorene, phenanthrene, and diphenylmethane. While the first four substances are model compounds of wash oil, which has widely been used as a solvent to remove aromatics from coal oven gas, diphenylmethane is a high-boiling and low-melting compound that is a potential additive to modify the performance of wash oil. Each of the seven binaries appears to be a simple eutectic system, as evidenced by the experimental results. The Wilson and the NRTL models were employed to correlate the solid-liquid equilibrium data. Both activity coefficient models were found to represent accurately the nonideality of the liquid-phase for the investigated systems.

Lee, M.J.; Chen, C.H.; Lin, H. [National Taiwan Univ. of Science and Technology, Taipei (Taiwan, Province of China). Dept. of Chemical Engineering

1999-09-01

119

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

120

Using scanning electrochemical microscopy to probe chemistry at the solid-liquid interface in chemically amplified immersion lithography  

Microsoft Academic Search

Three modes of scanning electrochemical microscopy (SECM) - voltammetry, pH, and conductivity - have been used to better understand the chemistry at, and diffusion through, the solid\\/liquid interface formed between a resist film and water in 193 nm immersion lithography. Emphasis has been placed on investigating the photoacid generator (PAG), triphenylsulfonium perfluorobutanesulfonate, and the corresponding photoacid. The reduction of triphenylsulfonium

Robert J. LeSuer; Fu-Ren F. Fan; Allen J. Bard; J. Christopher Taylor; Pavlos Tsiartas; Grant Willson; Willard E. Conley; Gene Feit; Roderick R. Kunz

2004-01-01

121

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

Microsoft Academic Search

The use of membranes for solid-liquid separation in BNRAS systems is investigated on a lab scale. The initial phase of investigation suggested that they are i) entirely feasible technically, ii) influence the design of the BNR system and WWTP design greatly, and iii) offer several advantages over BNR systems using secondary settling tanks such as improved effluent quality, which is

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

2007-01-01

122

Research on the pattern of solid-liquid two-phase distribution in chemical process pump  

NASA Astrophysics Data System (ADS)

In order to explore the pattern of solid-liquid two-phase flow distribution in first stage of double-suction impeller and the double volute channel of the HD type petrol-chemical process pump, the flow field in double-suction impeller and double volute is simulated with the CFD software, by taking the Reynolds Averaged Navier Stokes equations as its governing equations, and the standard k-? model for turbulence, derives the pattern of solid particle concentration distribution in the impeller and double volute channel under different initial particle concentrations and different particle diameters. The results show that in the double-suction impeller, solid phase distribution changes a lot along with the increase of initial particle concentration; the concentration near the back side is higher than the face side. Solid particles have the motion trend to the back side of blade in double-suction impeller along with the increase of particle diameters. In double volute channel, solid phase concentration distribution is uneven and solid particle concentration is relatively higher from section 1 to section 8. In the diffusion section, concentration is high in lateral side and low in medial side, the solid particles have the motion trend to the lateral side and the solid particle concentration is relatively higher.

Liu, Y.; Jiang, Y.; Han, Z. J.

2012-11-01

123

Vapor-Induced Solid-Liquid-Solid Process for Silicon-based Nanowire Growth  

SciTech Connect

Silicon based nanowires have been grown from commercial silicon powders under conditions of differing oxygen and carbon activities. Nanowires grown in the presence of carbon sources consisted of a crystalline SiC core with an amorphous SiOx shell. The thickness of SiOx shell decreased as the oxygen concentration in the precursor gases was lowered. Nanowires grown in a carbon-free environment consisted of amorphous silicon oxide with a typical composition of SiO1.8. The growth rate of nanowires decreased with decreasing oxygen content in the precursor gases. SiO1.8 nanowires exhibited an initial discharge capacity of ~ 1,300 mAh/g and better stability than those of silicon powders. A Vapor Induced Solid-Liquid-Solid (VI-SLS) mechanism is proposed to explain the nanowire growth (including silicon and other metal based nanowires) from powder sources. In this approach, both a gas source and a solid powder source are required for nanowire growth. This mechanism is consistent with experimental observations and can also be used to guide the design and growth of other nanowires.

Zhang, Jiguang; Liu, Jun; Wang, Donghai; Choi, Daiwon; Fifield, Leonard S.; Wang, Chong M.; Xia, Guanguang; Nie, Zimin; Yang, Zhenguo; Pederson, Larry R.; Graff, Gordon L.

2010-03-10

124

The contact line behaviour of solid-liquid-gas diffuse-interface models  

NASA Astrophysics Data System (ADS)

A solid-liquid-gas moving contact line is considered through a diffuse-interface model with the classical boundary condition of no-slip at the solid surface. Examination of the asymptotic behaviour as the contact line is approached shows that the relaxation of the classical model of a sharp liquid-gas interface, whilst retaining the no-slip condition, resolves the stress, and pressure singularities associated with the moving contact line problem while the fluid velocity is well defined (not multi-valued). The moving contact line behaviour is analysed for a general problem relevant for any density dependent dynamic viscosity and volume viscosity, and for general microscopic contact angle and double well free-energy forms. Away from the contact line, analysis of the diffuse-interface model shows that the Navier-Stokes equations and classical interfacial boundary conditions are obtained at leading order in the sharp-interface limit, justifying the creeping flow problem imposed in an intermediate region in the seminal work of Seppecher [Int. J. Eng. Sci. 34, 977-992 (1996)]. Corrections to Seppecher's work are given, as an incorrect solution form was originally used.

Sibley, David N.; Nold, Andreas; Savva, Nikos; Kalliadasis, Serafim

2013-09-01

125

Migration of cadmium through a natural porous medium : Influence of the solid-liquid interface processes  

NASA Astrophysics Data System (ADS)

Contaminated groundwater typically contains different metal contaminants which may compete with each other for the same adsorption sites. Understanding the fate of these micro-pollutants is of primary importance for the assessment of the risk associated to their dispersion in the environment and for the evaluation of the most appropriate remediation technology. By this regard, column techniques can be considered as a useful tool both to perform transport experiments and to obtain equilibrium adsorption data without any perturbation of the solid-liquid interface. Cd and Pb mono-component step column experiments were performed to obtain adsorption isotherms with a natural aquifer material. General Composite approach was used to define the equilibrium adsorption model characterised by two types of sites (ion-exchange and surface complexation sites). Coupling the adsorption model to the Advection-Dispersion equation (by IMPACT code) allowed to well represent the mono-component step experiments. The model was successfully used to predict the competitive Cd and Pb transport behaviour.

Petrangeli Papini, M.; Bianchi, A.; Behra, P.; Majone, M.; Beccari, M.

2003-05-01

126

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 GaPO4 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

127

Measurements of Solid-Liquid Interfacial Energies in the Organic Monotectic Alloys  

NASA Astrophysics Data System (ADS)

The commercial purity dibromobenzene (DBB) and succinonitrile (SCN) were purified using a columnar distillation system. Thin walled rectangular specimen cells (60-80 ?m thick) were fabricated and filled with the purified materials under the vacuum. The specimen cell was placed in a horizontal temperature gradient stage. A thin liquid layer was melted and the specimen was annealed in a constant temperature gradient for an enough time to observe the equilibrated grain boundary groove shapes. The thermal conductivities of solid and liquid phases for the purified DBB and DBB-5.7 mol% SCN alloy were determined with the radial heat flow and the Bridgman-type growth apparatuses. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficients, solid-liquid interfacial energies, and the grain boundary energies for solid DBB in equilibrium with its melts and solid DBB in equilibrium with DBB-SCN monotectic liquid have been determined. The temperature coefficients of the purified DBB and DBB-5.7 mol% SCN alloy were also determined from thermal conductivity curve vs temperature.

Böyük, U.; Yüceer, K.; Ke?lio?lu, K.; Ulgen, A.; Mara?li, N.

128

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

129

A theoretical study of the pipe-flow of turbulent solid-liquid suspensions  

SciTech Connect

The aim of this investigation was to establish a theoretical approach to estimate the relevant design variables for hydraulic transport of solids using pipelines. In the first phase of the study a mathematical theory was proposed from first principles to evaluate the total pressure drop in a pipe carrying a solid-liquid suspension under fully turbulent flow. An expression was developed for the excess pressure loss function which for the first time identified the interactions of the various hydrodynamics parameters. This zeroth-order model correlates the experimental data quite well with the help of one adjustable parameter. In the second phase of the study, the equation of motion was solved numerically to yield a realistic velocity profile and pressure drop. This velocity profile reflects the settling tendency of the solids. The prediction of the design parameters using this model is good at higher velocities. Finally, the feasibility of using the transitional flow theory to improve the zeroth-order model was evaluated. This investigation has established a basic methodology for developing a comprehensive simulation technique and identified the areas of future research to adapt similar methods for hydrotransport of industrial slurries.

Sen, S.

1988-01-01

130

Rapid heating of a strongly coupled plasma at the solid-liquid phase transition  

NASA Astrophysics Data System (ADS)

Between 10^4 and 10^6 ^9Be^+ ions are trapped in a 4.5 Tesla Penning trap and laser-cooled to ˜1 mK, where the ions form a crystalline plasma with an interparticle spacing of ˜20 ?m. This system is a realization of a strongly coupled one-component plasma. Using Doppler laser spectroscopy on a single-photon transition, we measured the temperature and heating rate of this plasma when not being laser-cooled. We measured a slow heating rate of ? 100 mK/s due to residual gas collisions for the first 100-200 ms after turning off the cooling laser. This slow heating is followed by a rapid heating to 1-2 K in 100 ms as the plasma undergoes the solid-liquid phase transition at T=10 mK (? ˜ 170). We will present evidence that this rapid heating is due to a sudden release of energy from weakly cooled degrees of freedom involving the cyclotron motion of trapped impurity ions. We will also discuss the prospects for observing the latent heat associated with the phase transition.

Jensen, M. J.; Hasegawa, T.; Bollinger, J. J.; Dubin, D. H. E.

2004-11-01

131

Fluctuations and criticality of a granular solid-liquid-like phase transition.  

PubMed

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 ?(perpendicular))=1, ?(parallel)=2, ?=1, ?=0.67, and ?=1/2, whereas the dynamical critical exponent z=?(parallel)/?(perpendicular)=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). PMID:23002853

Castillo, Gustavo; Mujica, Nicolás; Soto, Rodrigo

2012-08-27

132

Acoustic Monitor for Solid-Liquid Slurries Measurements at Low Weight Fractions  

SciTech Connect

We have developed an acoustic monitor for accurate, real-time measurement of solids concentration in solid-liquid (S-L) and solid-gas-liquid (S-G-L) slurries at low solids weight percent (0.5 to 10 wt. %). The Syracuse Acoustic Monitor (SAM) has potential for slurry transport monitoring, processing stream monitoring, and process control capabilities for nuclear wastes treatment throughout the DOE complex. The SAM is based on theory that predicts attenuation of small-amplitude acoustic waves propagating through S-L and S-L-G suspensions. We developed a prototype in-line system with robust data acquisition capabilities to continually acquire attenuation data (response time of 0.5 sec) for a 0.6-12 MHz frequency range with an array of transducers. Test results on an integrated flow loop indicate high accuracy between 0.5 and 8.0 weight percent solids for ceramic microspheres (80 {micro}m average diameter) and kaolin-bentonite slurries. Results of removal of the interference caused by gas bubbles, thus providing the solids weight percent, will also be discussed.

Tavlarides, Lawrence L.; Shcherbakov, Oleksandr; Dievendorf, Eric; Sangini, Ashok

2003-09-10

133

Factors influencing antibody stability at solid-liquid interfaces in a high shear environment.  

PubMed

A rotating disk shear device was used to study the effect of interfacial shear on the structural integrity of human monoclonal antibodies of IgG4 isotype. Factors associated with the solution conditions (pH, ionic strength, surfactant concentration, temperature) and the interface (surface roughness) were studied for their effect on the rate of IgG4 monomer loss under high shear conditions. The structural integrity of the IgG4 was probed after exposure to interfacial shear effects by SDS-PAGE, IEF, dynamic light scattering, and peptide mapping by LC-MS. This analysis revealed that the main denaturation pathway of IgG4 exposed to these effects was the formation of large insoluble aggregates. Soluble aggregation, breakdown in primary structure, and chemical modifications were not detected. The dominant factors found to affect the rate of IgG4 monomer loss under interfacial shear conditions were found to be pH and the nanometer-scale surface roughness associated with the solid-liquid interface. Interestingly, temperature was not found to be a significant factor in the range tested (15-45 degrees C). The addition of surfactant was found to have a significant stabilizing effect at concentrations up to 0.02% (w/v). Implications of these findings for the bioprocessing of this class of therapeutic protein are briefly discussed. PMID:19585551

Biddlecombe, James G; Smith, Graeme; Uddin, Shahid; Mulot, Sandrine; Spencer, David; Gee, Chris; Fish, Brendan C; Bracewell, Daniel G

134

Solid-Liquid Equilibria for the CO2 + R143a and N2O + R143a Systems  

NASA Astrophysics Data System (ADS)

A recently built experimental setup for determination of solid-liquid equilibria was slightly modified. The action taken on the existing system focused on correcting the drawbacks of the cooling system. In this version of the setup, a direct liquid nitrogen supply was preferred. By means of the modified apparatus, solid-liquid equilibria of the CO2 + R143a and N2O + R143a binary systems were studied. The triple point of R143a was measured to check the reliability of the modified apparatus, revealing good consistency with the literature. The system’s behavior was measured down to temperatures of 148 K. The results obtained for the mixtures were interpreted by means of the Schröder equation.

di Nicola, Giovanni; Moglie, Matteo; Santori, Giulio; Stryjek, Roman

2009-07-01

135

A New Thermodynamic Method for Solid-Liquid-Vapor Equilibrium in Ternary Antisolvent Crystallization Systems Using Binary Data  

Microsoft Academic Search

Prediction of the solid-liquid-vapor (S-L-V) equilibrium data for the ternary (CO2 -solvent- solid) systems is needed in the design and analysis of Supercritical Antisolvent (SAS) or Gas Antisolvent (GAS) crystallization processes using CO2 as the antisolvent. A new model is presented in this paper for the prediction of the ternary (S-L-V) equilibrium compositions from the binary interaction constants of (CO

Mamata Mukhopadhyay; Sameer V. Dalvi

136

Partitioning of Mercury Among Solid, Liquid and Gas Phases Following Anaerobic Decomposition of a Simulated Solid Waste  

Microsoft Academic Search

The purpose of this study was to determine the partitioning of Hg among solid, liquid, and gas phases following anaerobicdecomposition of a simulated solid waste. A simulated solid waste was spiked with Hg(NO3)2, placed in anaerobic, leachbed reactors, and allowed to undergo anaerobicdecomposition. Methane yields, volatile fatty acidproduction, and pH indicated that the reactors wereperforming as expected for anaerobic decompositionin

Celia D. A. Earle; R. D. Rhue; D. P. Chynoweth

2000-01-01

137

Active ultrasonic cross-correlation flowmeters for mixed-phase pipe flows. [Solid\\/liquid and solid\\/gas flows  

Microsoft Academic Search

This paper describes two ultrasonic flowmeters which employ the active cross-correlation technique and uses a simple clamp-on transducer arrangement. The flowmeter for solid\\/liquid flows was tested over a wide range of coal concentration in water and oil. The measured velocity based on the peak position of the cross-correlation function is consistently higher by about 15% than the average velocity measured

S. H. Sheen; A. C. Raptis

1984-01-01

138

Investigation of Complexation and Solid–liquid Extraction of Ironfrom Paper by UV\\/VIS and Atomic Absorption Spectrometry  

Microsoft Academic Search

.  ?The aim of this study was to evaluate the strategy for the investigation the possibility of diminishing the iron-gall ink corrosion process occurring often in ancient manuscripts. In order to understand the respective processes, the efficiency of iron complex\\u000a formation as well as solid–liquid extraction of iron compounds from the paper was investigated by UV\\/VIS spectrometry and\\u000a by graphite furnace

Ewa Bulska; Barbara Wagner; Marek G. Sawicki

2001-01-01

139

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

140

Study of the solid-liquid-vapour phase equilibria of flexible chain molecules using Wertheim's thermodynamic perturbation theory  

Microsoft Academic Search

The phase diagram of flexible molecules formed by freely-jointed tangent spheres is studied using the first-order thermodynamic perturbation theory of Wertheim for both fluid and solid phases. A mean-field term is added to the free energy of the fluid and solid phase in order to account for attractive dispersion forces. The approach is used to determine the global (solid-liquid-vapour) phase

Felipe J. Blas; Amparo Galindo; Carlos Vega

2003-01-01

141

A dynamic model for the interaction between a solid particle and an advancing solid\\/liquid interface  

Microsoft Academic Search

Most models that describe the interaction of an insoluble particle with an advancing solid-liquid interface are based on the\\u000a assumption of steady state. However, as demonstrated by experimental work, the process does not reach steady state until the\\u000a particle is pushed for a while by the interface. In this work, a dynamic mathematical model was developed. The dynamic model\\u000a demonstrates

Adrian V. Catalina; Sundeep Mukherjee; DORU M. STEFANESCU

2000-01-01

142

A molecular dynamics study to determine the solid-liquid interfacial tension using test area simulation method (TASM).  

PubMed

Molecular dynamics (MD) studies on heat transfer from a heated nanoparticle into the surrounding fluid have indicated that the fluid next to a spherical nanoparticle can get heated well above its boiling point without observing a phase change, while a contradicting behavior was observed for a flat surface-fluid interface. Another interesting observation is that the critical heat flux was found to increase with increase in the wetting characteristics of solid. Thus, the interfacial tension or free energy of solid-liquid interface could play a pivotal role in the mechanism of heat transfer. A recent study by Gloor et al. [J. Chem. Phys. 123, 134703 (2005)] has proposed test area simulation method (TASM) for the determination of interfacial tension. The present study involves the determination and the comparison of solid-liquid interfacial tension for planar and spherical interfaces using MD based on TASM and analyze the results. A higher interfacial tension value is observed for spherical nanoparticle fluid interface compared to flat surface fluid interface. The results also indicate that the solid-liquid interfacial tension is a size and temperature dependent property. The results from this study are also expected to give better insights into the possible reasons for the observed differences in the thermal transport for spherical nanoparticle-liquid interface compared to planar-liquid interface. PMID:22938254

Nair, Anjan R; Sathian, Sarith P

2012-08-28

143

A molecular dynamics study to determine the solid-liquid interfacial tension using test area simulation method (TASM)  

NASA Astrophysics Data System (ADS)

Molecular dynamics (MD) studies on heat transfer from a heated nanoparticle into the surrounding fluid have indicated that the fluid next to a spherical nanoparticle can get heated well above its boiling point without observing a phase change, while a contradicting behavior was observed for a flat surface-fluid interface. Another interesting observation is that the critical heat flux was found to increase with increase in the wetting characteristics of solid. Thus, the interfacial tension or free energy of solid-liquid interface could play a pivotal role in the mechanism of heat transfer. A recent study by Gloor et al. [J. Chem. Phys. 123, 134703 (2005)] has proposed test area simulation method (TASM) for the determination of interfacial tension. The present study involves the determination and the comparison of solid-liquid interfacial tension for planar and spherical interfaces using MD based on TASM and analyze the results. A higher interfacial tension value is observed for spherical nanoparticle fluid interface compared to flat surface fluid interface. The results also indicate that the solid-liquid interfacial tension is a size and temperature dependent property. The results from this study are also expected to give better insights into the possible reasons for the observed differences in the thermal transport for spherical nanoparticle-liquid interface compared to planar-liquid interface.

Nair, Anjan R.; Sathian, Sarith P.

2012-08-01

144

Properties of the solid-liquid interface of growing salol crystals: A dynamic light scattering investigation  

NASA Astrophysics Data System (ADS)

The freezing process has been studied by means of quasielastic light scattering at the solid-liquid interface of growing salol crystals. In the range of the investigated growth velocities, 0.2 ?ms<=vk<=0.8 ?ms, we observe two different dynamical processes at the interface, which can be distinguished by the scattered light. In a first process intense Rayleigh scattering sets in if a critical growth velocity is exceeded, which for growth along the [010] axis is in the range of 0.2 ?ms<=vcrit<=0.8 ?ms. Intensity measurements suggest that the scattering arises from fluctuations in an interface layer of a thickness of the order of 1?m. The spectrum of the scattered light can be fitted by a single Lorenzian with a linewidth ?=Diq2 (q--> is the scattering vector). The thus obtained value of the diffusion constant, Di=(1.0+/-0.25)×10-9 cm2 s-1, is by 6 orders of magnitude smaller than the thermal diffusivity of liquid salol. In a second process the light is scattered by a propagating line-grating-like structure, which we interpret in terms of almost equidistant steps of growth spirals originating at screw dislocations. The step spacing d was determined from the angular distribution of the scattered intensity, and the step velocity vs from the Doppler shift. For a growth velocity vk=0.5 ?m/s perpendicular to the (001) facet typical values are d=0.4 ?m and vs=40 ?m/s. For the step height h=vkdvs we obtain values of the order of 2.5 lattice constants. The product vsd is independent of vk and has a value of (1.8+/-0.4)×10-7 cm2 s-1, whereas vs is proportional to the square root of vk. An interpretation of the data is presented.

Dürig, U.; Bilgram, J. H.; Känzig, W.

1984-08-01

145

Assessment of Fluxless Solid Liquid Interdiffusion Bonding by Compressive Force of Au-PbSn and Au-SAC for Flip Chip Packaging  

Microsoft Academic Search

Flip chip packaging faces two primary bonding-process obstacles: flux use and geometry mismatch between die and substrate pad pitch. These obstacles motivated the development of a fluxless bonding method called solid-liquid interdiffusion bonding by compressive force (SLICF). SLICF utilizes a mechanical force to form the bond through solid-liquid interdiffusion with a joint-in-via (JIV) architecture for flip chip packaging. SLICF bonding

Teck Kheng Lee; Sam Zhang; Chee C. Wong; A. C. Tan

2009-01-01

146

A numerical analysis of solid-liquid phase change heat transfer around a single and two horizontal, vertically spaced cylinders in a rectangular cavity  

Microsoft Academic Search

In the present study, a new numerical model is proposed to analyze solid-liquid phase change heat transfer in a complicated geometry. The present model can treat the solid\\/liquid phase change heat transfer with\\/without porous media, as well as conventional transient natural convection with\\/without porous media. Solidification calculations of pure water (without porous media) around a single cylinder and two cylinders

R. Viskanta

1997-01-01

147

Adaptation de la separation cryomagnetique aux technologies de l'environnement: application a l'epuration d'effluents liquides industriels. (Cryo magnetic separation adaptation to environment technologies: application to industrial effluents).  

National Technical Information Service (NTIS)

Cryomagnetic separation adaptation to environment technologies application to industrial liquid effluents. The performance, obtained by superconducting high filed - high gradient magnetic separation, permitted to foresee the magnetic treatment of heavy me...

V. Bureau

1993-01-01

148

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

NASA Astrophysics Data System (ADS)

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

Nagahara, Larry Akio

149

Real time, high resolution studies of protein adsorption and structure at the solid liquid interface using dual polarization interferometry  

NASA Astrophysics Data System (ADS)

A novel method for the analysis of thin biological films, called dual polarization interferometry (DPI), is described. This high resolution (<1 Å), laboratory-based technique allows the thickness and refractive index (density) of biological molecules adsorbing or reacting at the solid-liquid interface to be measured in real time (up to 10 measurements per second). Results from the adsorption of bovine serum albumin (BSA) on to a silicon oxynitride chip surface are presented to demonstrate how time dependent molecular behaviour can be examined using DPI. Mechanistic and structural information relating to the adsorption process is obtained as a function of the solution pH.

Freeman, Neville J.; Peel, Louise L.; Swann, Marcus J.; Cross, Graham H.; Reeves, Andrew; Brand, Stuart; Lu, Jian R.

2004-07-01

150

Dynamics of solid\\/liquid interface shape evolution near an insoluble particle—An X-ray transmission microscopy investigation  

Microsoft Academic Search

In this article, for the first time, in situ and real-time experimental observations of changes in solid\\/liquid (s\\/l) interface shape during interactions with a particle\\u000a or void are reported for metallic systems. Real-time interface shape evolution for both stationary and growing interfaces\\u000a was observed by use of a state-of-the-art X-ray transmission microscope. Localized interfacial perturbations were studied\\u000a as a function

S. Sen; P. Curreri; W. F. Kaukler; D. M. Stefanescu

1997-01-01

151

Maladies reli?es aux loisirs aquatiques  

PubMed Central

Résumé Objectif Passer en revue les facteurs de risque, la prise en charge et la prévention des maladies reliées aux loisirs aquatiques en pratique familiale. Sources des données Des articles originaux et de synthèse entre janvier 1998 et février 2012 ont été identifiés à l’aide de PubMed et des expressions de recherche en anglais water-related illness, recreational water illness et swimmer illness. Message principal Il y a un risque de 3 % à 8 % de maladies gastrointestinales (MGI) après la baignade. Les groupes à risque élevé de MGI sont les enfants de moins de 5 ans, surtout s’ils n’ont pas été vaccinés contre le rotavirus, les personnes âgées et les patients immunodéficients. Les enfants sont à plus grand risque parce qu’ils avalent plus d’eau quand ils nagent, restent dans l’eau plus longtemps et jouent dans l’eau peu profonde et le sable qui sont plus contaminés. Les adeptes des sports dans lesquels le contact avec l’eau est abondant comme le triathlon et le surf cerf-volant sont aussi à risque élevé et même ceux qui s’adonnent à des activités impliquant un contact partiel avec l’eau comme la navigation de plaisance et la pêche ont un risque de 40 % à 50 % fois plus grand de MGI par rapport à ceux qui ne pratiquent pas de sports aquatiques. Il y a lieu de faire une culture des selles quand on soupçonne une maladie reliée aux loisirs aquatiques et l’échelle clinique de la déshydratation est utile pour l’évaluation des besoins de traitement chez les enfants affectés. Conclusion Les maladies reliées aux loisirs aquatiques est la principale cause de MGI durant la saison des baignades. La reconnaissance que la baignade est une source importante de maladies peut aider à prévenir les cas récurrents et secondaires. On recommande fortement le vaccin contre le rotavirus chez les enfants qui se baignent souvent.

Sanborn, Margaret; Takaro, Tim

2013-01-01

152

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

153

Les disparités de recours aux soins en 1991  

Microsoft Academic Search

[fre] Les disparités de recours aux soins en 1991 . En termes quantitatifs, les disparités sociales de recours aux médecins sont limitées. En revanche, les écarts de comportements liés à la catégorie de praticiens auxquels s'adressent les patients sont plus importants : un quart des séances de soins des ouvriers et des paysans ont lieu chez un spécialiste alors que

Pierre Mormiche

1993-01-01

154

Grazing-incidence neutron-induced fluorescence probes density profiles of labeled molecules at solid/liquid interfaces.  

PubMed

We report on the use of characteristic prompt ?-fluorescence after neutron capture induced by an evanescent neutron wave to probe densities and depth profiles of labeled molecules at solid/liquid interfaces. In contrast to classical scattering techniques and X-ray fluorescence, this method of "grazing-incidence neutron-induced fluorescence" combines direct chemical specificity, provided by the label, with sensitivity to the interface, inherent to the evanescent wave. We demonstrate that the formation of a supported lipid membrane can be quantitatively monitored from the characteristic fluorescence of (157)Gd(3+) ions bound to the headgroup of chelator lipids. Moreover, we were able to localize the (157)Gd(3+) ions along the surface normal with nanometer precision. This first proof of principle with a well-defined model system suggests that the method has a great potential for biology and soft matter studies where spatial resolution and chemical sensitivity are required. PMID:23461763

Schneck, Emanuel; Jentschel, Michael; Gege, Christian; Tanaka, Motomu; Demé, Bruno

2013-03-14

155

Localized electrochemical impedance spectroscopy: visualization of spatial distributions of the key parameters describing solid/liquid interfaces.  

PubMed

Acquisition of localized electrochemical impedance spectra as a function of spatial coordinates combined with novel approaches of data analysis brings a key for visualization of two-dimensional distributions of important parameters describing solid/liquid interfaces. They include the capacitance of the electric double layer, the resistance of the interfacial charge transfer, capacitances of adsorption, or other parameters depending on the properties of the system. Additionally, the proposed approach eliminates many common methodological problems of localized electrochemical impedance microscopies related to the frequency dependence of the actual pictures and difficulties with raw data interpretation. Thus, it offers a unique insight into the localized processes at the interface which is not possible to achieve using classical techniques. PMID:23331057

Bandarenka, Aliaksandr S; Eckhard, Kathrin; Maljusch, Artjom; Schuhmann, Wolfgang

2013-02-04

156

A Diffuse Interface Model for solid-liquid-air dissolution problems based on a porous medium theory  

NASA Astrophysics Data System (ADS)

The underground cavities may be dissolved by the flows of groundwater where the dissolution mainly happens at the liquid-solid interface. In many real cases, the cavities are not occupied only by the water, but also the gas phase, e.g., air, or other gases. In this case, there are solid-liquid-gas three phases. Normally, the air does not participate the dissolution. However, it may influence the dissolution as the position of the solid-liquid interface may gradually lower down with the dissolution process. Simulating the dissolution problems with multi- moving interfaces is a difficult task but rather interesting to study the evolution of the underground cavities. In this paper, we propose a diffuse interface model (DIM) to simulate the three-phase dissolution problem, based on a porous medium theory and a volume averaging theory te{Whitaker1999,Golfier2002,Quintard1994}. The interface is regarded as a continuous layer where the phase indicator (mainly for solid-liquid interface) and phase saturation (mainly for liquid-gas interface) vary rapidly but smoothly. The DIM equations enable us to simulate the moving interface under a fixed mesh system, instead of a deformed or moving mesh. Suppose we have three phases, solid, liquid and gas. The solid phase contains only species A. The gas phase contains only the air. The volume averaging theory is used to upscale the balance equations. The final DIM equations are presented below. The balance equation of solid phase can be written as {partialrho_{s}(1-\\varepsilon_{f})}/{partial t}=-K_{sl} where \\varepsilonf represents the volume fraction of the fluids (liquid+gas) and Ksl refers to the mass exchange between the solid phase and the liquid phase. Ksl cam be expressed as K_{sl}=rho_{l}alpha(omega_{eq}-Omega_{Al}). The balance equations of liquid phase can be written as {partialrho_{l}\\varepsilon_{f}S_{l}}/{partial t}+nabla\\cdot(rho_{l}{V}_{l})= K_{sl}. The balance equation of liquid phase can be written as {partialrho_{g}\\varepsilon_{f}(1-S_{l})}/{partial t}+nabla\\cdot(rho_{g}{V}_{g}) =0. The balance equations of species A can be written as rho_{l}\\varepsilon_{f}S_{l} {partialOmega_{Al}}/{partial t} +rho_{l}{V}_{l}\\cdotnablaOmega_{Al} =nabla\\cdot(rho_{l}{D}_{Al}^{*}nablaOmega_{Al})+K_{sl}. We introduce the multi-phase Darcy's Law to {V}l and {V}g, {V}_{l}=-{{K}k_{rl}}/{mu_{l}}(nabla P_{l}-rho_{l}{g}) {V}_{g}=-{K}k_{rg}}/{mu_{g}}(nabla P_{g}-rho_{g}{g}) Kozeny-Carman equation is introduced to calculate {K}, Capillary pressure theory can be used to calculate krl, krg, and the capillary pressure Pc, as a function of Sl.

Luo, H.; Quintard, M.; Debenest, G.; Laouafa, F.

2011-12-01

157

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

158

Solid-liquid interfacial energy of neopentylglycol solid solution in equilibrium with succinonitrile-neopentylglycol-aminomethylpropanediol liquid  

NASA Astrophysics Data System (ADS)

The grain boundary groove shapes for equilibrated solid neopentylglycol (NPG) solution (NPG-26 mol% AMPD-4 mol% SCN) in equilibrium with the succinonitrile (SCN)-neopentylglycol (NPG)-aminomethylpropanediol (AMPD) liquid (NPG-45 mol% SCN-2 .9 mol% AMPD) have been directly observed by using a horizontal linear temperature gradient apparatus. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficient (?) and solid-liquid interfacial energy (?SL) of solid NPG solution have been determined to be (7.8±0.8)×10-8 K m and (8.1±1.2)×10-3 J m-2, respectively. The grain boundary energy of solid NPG solution has been determined to be (15.8±2.5)×10-3 J m-2 from the observed grain boundary groove shapes. The ratio of thermal conductivity of equilibrated liquid to thermal conductivity of solid NPG solution has also been determined to be 0.42.

Özer, A.; Bayram, Ü.; Aksöz, S.; Mara?l?, N.

2013-02-01

159

Fourier transform infrared measurement of solid-, liquid-, and gas-phase samples with a single photoacoustic cell.  

PubMed

A photoacoustic detector based on the optical cantilever microphone has been built. The detector is capable of measuring solid-, liquid-, and gas-phase samples. Photoacoustic Fourier transform infrared (FT-IR) measurement with three samples in different phases was demonstrated. Example samples were polyethene, sunflower oil, and methane. The sensitivity of the cell was compared to a commercial photoacoustic FT-IR detector. With the standard carbon black sample the cantilever detector gave approximately five times higher signal-to-noise ratio than the reference detector. The sensitivity with methane was also compared to the DTGS detector of the FT-IR instrument corresponding to an absorption path of 6.3 cm. Simulation of the photoacoustic signal showed that a compromise has to be made in the cell design between sensitivity for solid- and gas-phase samples but it is possible to highly enhance the sensitivity for all types of samples by reducing cantilever dimensions. PMID:18559153

Uotila, Juho; Kauppinen, Jyrki

2008-06-01

160

Free-surface optical scattering as an indicator of the shock-induced solid-liquid phase transition in tin  

NASA Astrophysics Data System (ADS)

When highly polished metal surfaces melt upon release after shock loading, they exhibit features that suggest that significant surface changes accompany the phase transition. The reflection of light from such surfaces changes from specular (preshock) to diffuse upon melting. A familiar manifestation of this phenomenon is the loss of signal light observed with a velocity interferometer system for any reflector, which occurs at pressures high enough to melt the free surface. Unlike many other potential material phase-sensitive diagnostics (e.g., reflectometry and conductivity) that show relatively small changes, the specularity of reflection provides a more sensitive and definitive indication of the solid-liquid phase transition. Data are 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

161

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

162

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

PubMed

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. PMID:23787754

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

2013-06-02

163

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

164

Environmental assessment of the HYGAS process. Volume III. Interim report on HYGAS environmental characterization: manual of methods for characterization of HYGAS pilot plant solids, liquids, and gases  

Microsoft Academic Search

The US Department of Energy (DOE) has commissioned the HYGAS environmental assessment program to characterize various solid, liquid, and gaseous streams in the HYGAS pilot plant. The purpose of this manual is to describe the various analytical techniques that have been used to analyze pilot plant streams for environmental species. Many of the techniques have been recommended by the US

R. H. Karst; J. L. Passaniti; T. C. Metcalf; E. V. Salazar; J. C. Pau

1980-01-01

165

Pre-Service Primary Science Teachers' Understandings of the Effect of Temperature and Pressure on Solid-Liquid Phase Transition of Water  

ERIC Educational Resources Information Center

|The aim of this study was to explore pre-service primary teachers' understandings of the effect of temperature and pressure on the solid-liquid phase transition of water. In the study a survey approach was used, and the sample consisted of one-hundred and three, third year pre-service primary science teachers. As a tool for data collection, a…

Yalcin, Fatma Aggul

2012-01-01

166

The theoretical simulation of the effect of solid–liquid contact angle on the critical heat flux of saturated water jet boiling on stagnation zone  

Microsoft Academic Search

A theoretical simulation was carried out for predicting the critical heat flux (CHF) of convective boiling for a round saturated water jet impingement on the stagnation zone of a hot surface. The study was focused on the effect of the solid–liquid contact angle on the CHF. A theoretical model based on the Long wave instability was applied to calculate the

Yu-hao Qiu; Zhen-hua Liu

2010-01-01

167

Surface composition variation and high-vacuum performance of DLC/ILs solid-liquid lubricating coatings: Influence of space irradiation  

NASA Astrophysics Data System (ADS)

In this paper, we fabricated a DLC/ionic liquid (DLC/ILs) solid-liquid lubricating coating and investigated the effect of atomic oxygen (AO), ultraviolet (UV), proton and electron irradiations on composition, structure, morphology and tribological properties of the DLC/ILs solid-liquid lubricating coatings. A ground-based simulation facility was employed to carry out the irradiation experiments. X-ray photoelectron spectroscope (XPS), Raman spectra, and Fourier Transform Infrared Spectroscopy (FTIR) were used to analyzed the structure and composition changes of DLC film and IL lubricant before and after irradiations. The tribological behavior of the DLC/ILs solid-liquid lubricating coating before and after irradiations was investigated by a vacuum tribometer with the pressure of 10-5 Pa. The experimental results revealed that irradiations induced the structural changes, including oxidation, bond break and crosslinking reactions of DLC film and IL lubricant. The damage of proton and AO irradiations to lubricating materials were the most serious, and UV irradiation was the slightest. After irradiations, the friction coefficient of the solid-liquid lubricating coatings decreased (except for AO irradiation), but the disc wear rate increased compared with non-irradiation coatings.

Liu, Xiufang; Wang, Liping; Pu, Jibin; Xue, Qunji

2012-08-01

168

Pre-Service Primary Science Teachers' Understandings of the Effect of Temperature and Pressure on Solid-Liquid Phase Transition of Water  

ERIC Educational Resources Information Center

The aim of this study was to explore pre-service primary teachers' understandings of the effect of temperature and pressure on the solid-liquid phase transition of water. In the study a survey approach was used, and the sample consisted of one-hundred and three, third year pre-service primary science teachers. As a tool for data collection, a test…

Yalcin, Fatma Aggul

2012-01-01

169

Comparison of Medium Pressure Solid–Liquid Extraction and Rotation Planar Extraction of Ficus Leaves with Reference to Optimum Operating Parameters  

Microsoft Academic Search

The effect of three operating variables on the extraction efficiency of medium pressure solid–liquid extraction (MPSLE) was studied using a factorial experimental design with three levels. The operating variables tested were medium particle size of the plant material, volume of extractant, and the equilibrium time between consecutive extractions of the same material. The possibility of scaling up the MPSLE extraction

Teijo Yrjönen; Irena Vovk; Breda Simonovska; Ola Mousa; Raimo Hiltunen; Heikki Vuorela; Pia Vuorela

2003-01-01

170

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

171

Study of the surfactant nanostructures at the solid\\/liquid interface  

Microsoft Academic Search

Surfactant adsorption is widely studied because it is related to many technological applications, such as wetting, adhesion, emulsion, foam, separation science, polymer blends and composites and stabilization of colloidal dispersions. ^ Silicone surfactant, one of the most important members in nonionic surfactants family, exhibits superior performance in anti-foaming, corrosion protection, bactericidal, skin, hair, and fabric conditions. A group of trisiloxanes,

Jinping Dong

2003-01-01

172

Atomic Force Microscopy of Physical and Chemical Processes at the Solid-Liquid Interface  

Microsoft Academic Search

This thesis describes research using atomic force microscopy (AFM) to study dynamics of solid surfaces in contact with liquids. Specifically, three applications are described: electrochemistry (Chapters 1-3), crystal growth (Chapters 4 and 5), and biomineralization (Chapter 6). Chapter 1 shows the feasibility of using AFM to image metal atoms in liquid, which sets the stage for high -resolution electrochemistry. Chapter

Srinivas Manne

1994-01-01

173

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

SciTech Connect

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

Jayaraman, Saivenkataraman

2010-03-01

174

A Distributed Computing Infrastructure for Computational Thermodynamic Calculations of Solid-Liquid Phase Equilibria  

NASA Astrophysics Data System (ADS)

Software tools like MELTS (Ghiorso and Sack, 1995, CMP 119:197) and its derivatives (Ghiorso et al., 2002, G3 3:10.1029/2001GC000217) are sophisticated calculators used by geoscientists to quantify the chemistry of melt production, transport and storage. These tools utilize computational thermodynamics to evaluate the equilibrium state of the system under specified external conditions by minimizing a suitably constructed thermodynamic potential. Like any thermodynamically based tool, the principal advantage in employing these techniques to model igneous processes is the intrinsic ability to couple the chemistry and energetics of the evolution of the system in a self consistent and rigorous formalism. Access to MELTS is normally accomplished via a standalone X11-based executable or as a Java-based web applet. The latter is a dedicated client-server application rooted at the University of Chicago. Our on-going objective is the development of a distributed computing infrastructure to provide "MELTS-like" computations on demand to remote network users by utilizing a language independent client-server protocol based on CORBA. The advantages of this model are numerous. First, the burden of implementing and executing MELTS computations is centralized with a software implementation optimized to a compute cluster dedicated for that purpose. Improvements and updates to MELTS software are handled locally on the server side without intervention of the user and the server-model lessens the burden of supporting the computational code on a variety of hardware and OS platforms. Second, the client hardware platform does not incur the computational cost of performing a MELTS simulation and the remote user can focus on the task of incorporating results into their model. Third, the client user can write software in a computer language of their choosing and procedural calls to the MELTS library can be executed transparently over the network as if a local language-compatible library of routines is being accessed. Fourth, the flexibility of calling library functions means that the client has more control over the configuration and output of the MELTS calculation. Fifth, if the client computer is a multi-processor compute cluster capable of issuing parallel requests to the MELTS "remote" library, then these requests may be in turn parallelized to the server compute cluster to enhance throughput and performance. Application of this computational model to fluid dynamical simulations of melting and transport in the Earth's mantle is envisioned. Further information and example clients for utilizing the current prototype library for distributed computing applications can be found at http://melts.uchicago.edu.

Ghiorso, M. S.; Kress, V. C.

2004-12-01

175

Competitive transport of cadmium and lead through a natural porous medium: influence of the solid/liquid interface processes.  

PubMed

Contaminated groundwater typically contains different metal contaminants which may compete with each other for the same adsorption sites. Understanding the fate of these micro-pollutants is of primary importance for the assessment of the risk associated with their dispersion in the environment and for the evaluation of the most appropriate remediation technology. In this regard, column techniques can be considered as useful tools both to perform transport experiments and to obtain equilibrium adsorption data without any perturbation of the actual solid/liquid interface. Cd and Pb monocomponent step column experiments were used to obtain adsorption isotherms on a natural aquifer material. A General Composite approach was used to define the equilibrium adsorption model characterized by two types of sites (ion-exchange and surface complexation sites). Coupling the adsorption model with the Advection-Dispersion equation (by IMPACT code) allowed us to well represent the monocomponent step experiments. The model was successfully used to predict the competitive Cd and Pb transport behaviour. Cd peaks of concentration due to Pb competition were experimentally observed and simulated by the model. This behaviour can be described only by an accurate modelling of the interaction and cannot be predicted by simple isotherms (such as Langmuir or Freundlich type). PMID:14518849

Bianchi, A; Papini, M Petrangeli; Corsi, A; Behra, P; Beccari, M

2003-01-01

176

Freezing point and solid-liquid interfacial free energy of Stockmayer dipolar fluids: A molecular dynamics simulation study  

NASA Astrophysics Data System (ADS)

Stockmayer fluids are a prototype model system for dipolar fluids. We have computed the freezing temperatures of Stockmayer fluids at zero pressure using three different molecular-dynamics simulation methods, namely, the superheating-undercooling method, the constant-pressure and constant-temperature two-phase coexistence method, and the constant-pressure and constant-enthalpy two-phase coexistence method. The best estimate of the freezing temperature (in reduced unit) for the Stockmayer (SM) fluid with the dimensionless dipole moment ?*=1, 2, 3 is 0.656 +/- 0.001, 0.726 +/- 0.002, and 0.835 +/- 0.005, respectively. The freezing temperature increases with the dipolar strength. Moreover, for the first time, the solid-liquid interfacial free energies ? of the fcc (111), (110), and (100) interfaces are computed 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, i.e., ?100 > ?110 > ?111.

Wang, Jun; Apte, Pankaj A.; Morris, James R.; Zeng, Xiao Cheng

2013-09-01

177

Interaction mechanism of in-situ nano-TiN-AlN particles and solid/liquid interface during solidification.  

PubMed

This paper deals with the interaction mechanism between in situ nanometer-grade TiN-AlN particles and the solid/liquid (S/L) interface during the solidification of an in situ TiN-AlN/Al composite. According to the setting of a force balance for the particles in front of the S/L interface during solidification, F = F(buoyant) + F(repulsive) + F(viscous). We obtained the relationship between the critical cooling velocity of the liquid composite, Vr, and the size of the ceramic particle, rp. By this relationship formula, we can know that the S/L interface engulfs particles or pushes them to the crystal grain boundary during the solidification of a TiN-AlN/Al composite. It is found that Vr is proportional to the radius of ceramic particles by transmission electron microscope (TEM) observation. The TEM test indicates that the smaller the particle is, the more easily the S/L interface engulfs particles. PMID:14733152

Cui, Chunxiang; Li, Yanchun; Shen, Yutian; Sun, Jibing; Wang, Ru

2003-10-01

178

Temperature responsive flocculation and solid-liquid separations with charged random copolymers of poly(N-isopropyl acrylamide).  

PubMed

Temperature-responsive random copolymers based on poly(N-isopropyl acrylamide) (PNIPAM) with 15 mol% of either acrylic acid or dimethylaminoethyl acrylate quaternary chloride were prepared. The effect of the charge and its sign were investigated in the solid-liquid separation of silica and alumina mineral suspensions. The results were compared to PNIPAM homopolymer of similar molecular weight. PNIPAM copolymers of the same charge as the particles (co-ionic PNIPAM) act as dispersants at both 25°C and 50°C. Flocculation occurs when counter-ionic PNIPAM facilitates selective aggregation and rapid sedimentation of minerals at both 25°C and 50°C. Adsorption and desorption studies showed that, unlike non-ionic PNIPAM, little desorption of the counter-ionic copolymers from the oxides occurred after cooling a suspension from 50°C to below the lower critical solution temperature. Thus, incorporation of counter-ionic charge into the temperature sensitive polymer PNIPAM was found to reduce the sediment bed consolidation upon cooling when compared to PNIPAM homopolymers. The lack of secondary consolidation upon cooling is attributed to attractive inter-particle forces, such as conventional polyelectrolyte flocculation mechanisms (bridging, charge neutralization or charge patch) which persist at both 25°C and 50°C when counter-ionic PNIPAM is used. On the other hand, it was possible to obtain rapid sedimentation with the counter-ionic PNIAPMs even when they were added to the suspension already at 50°C, a process which has not been possible with neutral PNIPAM homopolymers. PMID:21565355

O'Shea, John-Paul; Qiao, Greg G; Franks, George V

2011-04-16

179

Freezing point and solid-liquid interfacial free energy of Stockmayer dipolar fluids: A molecular dynamics simulation study.  

PubMed

Stockmayer fluids are a prototype model system for dipolar fluids. We have computed the freezing temperatures of Stockmayer fluids at zero pressure using three different molecular-dynamics simulation methods, namely, the superheating-undercooling method, the constant-pressure and constant-temperature two-phase coexistence method, and the constant-pressure and constant-enthalpy two-phase coexistence method. The best estimate of the freezing temperature (in reduced unit) for the Stockmayer (SM) fluid with the dimensionless dipole moment ?(*)=1,?2,?3 is 0.656 ± 0.001, 0.726 ± 0.002, and 0.835 ± 0.005, respectively. The freezing temperature increases with the dipolar strength. Moreover, for the first time, the solid-liquid interfacial free energies ? of the fcc (111), (110), and (100) interfaces are computed 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, i.e., ?100 > ?110 > ?111. PMID:24070303

Wang, Jun; Apte, Pankaj A; Morris, James R; Zeng, Xiao Cheng

2013-09-21

180

Solid–liquid interfacial energy of solid succinonitrile solution in equilibrium with succinonitrile–neopentylglycol eutectic liquid  

NASA Astrophysics Data System (ADS)

The grain boundary groove shapes for solid succinonitrile solution (SCN–5 mole% NPG) in equilibrium with the succinonitrile (SCN)–neopentylglycol (NPG) eutectic liquid (SCN–9.55 mole% NPG) have been directly observed by using a horizontal linear temperature gradient apparatus at 317.1 K equilibrium temperature. From the observed grain boundary groove shapes, the Gibbs–Thomson coefficient (?) and solid-liquid interfacial energy (?SL) of solid SCN solution have been determined to be (5.43±0.50)×10?8 K m and (8.09±1.21)×10?3 J m?2, respectively. The grain boundary energy of solid SCN solution has been determined to be (14.22±2.28)×10?3 J m?2 from the observed grain boundary groove shapes. The thermal conductivity for SCN–9.55 mole% NPG eutectic solid phase and the thermal conductivity ratio of eutectic liquid phase to eutectic solid phase at the melting temperature have also been measured with a radial heat flow apparatus and Bridgman type growth apparatus, respectively.

Karada?, Saadet B.; Alt?ntas, Yemliha; Öztürk, Esra; Aksöz, Sezen; Ke?lio?lu, Kâz?m; Mara?l?, Necmettin

2013-10-01

181

Direct imaging of complex nano- to microscale interfaces involving solid, liquid, and gas phases.  

PubMed

Surfaces with special wetting properties not only can efficiently repel or attract liquids such as water and oils but also can prevent formation of biofilms, ice, and clathrate hydrates. Predicting the wetting properties of these special surfaces requires detailed knowledge of the composition and geometry of the interfacial region between the droplet and the underlying substrate. In this work we introduce a 3D quantitative method for direct nanoscale visualization of such interfaces. Specifically, we demonstrate direct nano- to microscale imaging of complex fluidic interfaces using cryostabilization in combination with cryogenic focused ion beam milling and SEM imaging. We show that application of this method yields quantitative information about the interfacial geometry of water condensate on superhydrophilic, superhydrophobic, and lubricant-impregnated surfaces with previously unattainable nanoscale resolution. This type of information is crucial to a fundamental understanding as well as the design of surfaces with special wetting properties. PMID:23020195

Rykaczewski, Konrad; Landin, Trevan; Walker, Marlon L; Scott, John Henry J; Varanasi, Kripa K

2012-10-03

182

Supramolecular Assembly of Organic-Inorganic Hybrid Polyoxometalate Nanoclusters at Solid-liquid Interface  

NASA Astrophysics Data System (ADS)

Polyoxometalate (POM) inorganic nanoclusters have recently emerged as building blocks for the design and synthesis of novel functional materials for broad applications ranging from catalysis to nanomedicines. Rather than taking the slow self-assembly of POMs in aqueous solutions, we have investigated the assembly of hybrid Anderson-type Mo-based POMs with organic ligands at a solid surface by Langmuir-Blodgett (LB) deposition and characterized the films by AFM, TEM, and X-ray diffraction. We have observed the formation of well-ordered monolayer or bilayer consisting of periodic arrangement of hybrid POM nanoclusters, showing a strong dependence on substrate chemistry and LB compression pressure. The controlled assembly of hybrid POM nanocluster films by LB deposition could be used as a template with stoichiometric crystalline nanostructure to the programmed assembly of novel multi-functional supramolecular complexes.

Qi, Na; Jing, Benxin; Zhu, Yingxi

2013-03-01

183

Friction and slip at the solid/liquid interface in vibrational systems.  

PubMed

Molecular dynamics simulations have been performed to study frictional slip and its influence on energy dissipation and momentum transfer at atomically smooth solid/water interfaces. By modifying the surface chemistry, we investigate the relationship between slip and the mechanical response of a vibrating solid for both hydrophilic and hydrophobic surfaces. We discover physical phenomena that emerge at high frequencies and that have significant contributions to energy dissipation. A new analytical model is developed to describe the mechanical response of the resonators in this high-frequency regime, which is relevant in such applications as microelectromechanical-system-based biosensors. We find a linear relationship between the slip length and the ratio of the damping rate shift to the resonant frequency shift, which provides a new way to obtain information about the slip length from experiments. PMID:23157613

Huang, Kai; Szlufarska, Izabela

2012-12-04

184

Modeling convective Marangoni flows with void movement in the presence of solid-liquid phase change  

NASA Astrophysics Data System (ADS)

This report describes a numerical method for solving heat conduction and fluid flow problems that involve phase changes. The complications arising from materials with different liquid and solid densities are discussed, and approximations are developed for Marangoni stress, curvature dependent pressure jumps and void movement. Applications to both 0-g and 1-g environments are discussed. The fluid flow algorithm is a variant of the projection method for incompressible liquids. A control volume method of discretization along with an appropriate formulation of the conservation laws for mass and momentum yield a weak form which applies throughout the computational region. In this form no fronts between liquid and solid or between liquid and void are explicitly tracked, though the position of the fronts is readily determined from the solution field variables. The discrete equations use an implicit Crank-Nicolson method. The non-linear implicit equations are solved using a Newton method with an Approximate Factorization method for the iterative solution of the Jacobian system.

Drake, John B.

1990-01-01

185

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

186

Thermodynamic study of binary system Propafenone Hydrocloride with Metoprolol Tartrate: solid-liquid equilibrium and compatibility with ?-lactose monohydrate and corn starch.  

PubMed

Solid-liquid equilibrium (SLE) for binary mixture of Propafenone Hydrocloride (PP) with Metoprolol Tartrate (MT) was investigated using differential scanning calorimetry (DSC) and corresponding activity coefficients were calculated. Simple eutectic behavior for this system was observed. The excess thermodynamic functions: G(E) and S(E) for the pre-, post-, and eutectic composition have been obtained using the computed activity coefficients data of the eutectic phase with their excess chemical potentials ?i(E) (i=1, 2). The experimental solid-liquid phase temperatures were compared with predictions obtained from available eutectic equilibrium models. The results indicate non-ideality in this mixture. Also, the compatibility of each component and their eutectic mixture with usual excipients was investigated, and the DSC experiments indicate possible weak interactions with ?-lactose monohydrate and compatibility with corn starch. The results obtained were confirmed by FT-IR measurements. PMID:23545398

Marinescu, Daniela-Crina; Pincu, Elena; Meltzer, Viorica

2013-03-29

187

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

SciTech Connect

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

Kabadi, V.N.

1995-06-30

188

Liquid-liquid and solid-liquid extraction of gold by trioctylmethylammonium chloride (TOMAC1) dissolved in toluene and impregnated on amberlite XAD-2 resin  

Microsoft Academic Search

The extraction of Au(III) with the extractant trioctylmethylammonium chloride (TOMAC1) dissolved in toluene and the same extractant impregnated in a polymeric resin XAD-2 has been studied. The results of gold extraction with both systems were compared. They showed similar gold extraction behaviour (extracted species), although greater amounts of extractant were needed when impregnated resins were used. Liquid-liquid and solid-liquid procedures

I. Villaescusa; V. Salvadó; J. de Pablo

1996-01-01

189

Measurement of the solids volume fraction and velocity distributions in solids–liquid flows using dual-plane electrical resistance tomography  

Microsoft Academic Search

This paper describes a dual-plane Electrical Resistance Tomography (ERT) system for measuring the local solids volume fraction distribution and the local solids axial velocity distribution in solids–liquid flows. The paper also describes a local, intrusive conductivity probe system for providing reference measurements of the distributions obtained using the dual-plane ERT system. Experiments were performed using both the ERT system and

G. P. Lucas; J. Cory; R. C. Waterfall; W. W. Loh; F. J. Dickin

1999-01-01

190

Processing of diamond particle dispersed aluminum matrix composites in continuous solid–liquid co-existent state by SPS and their thermal properties  

Microsoft Academic Search

Diamond-particle-dispersed-aluminum (Al) matrix composites were fabricated in a unique fabrication method where continuous solid–liquid co-existent state of the powder mixture of diamond, pure Al and Al–5mass%Si alloy was designed during spark plasma sintering (SPS) process. Microstructures and thermal properties of the composites fabricated in such a way were investigated. The composites can be well consolidated in the temperature range between

Kiyoshi Mizuuchi; Kanryu Inoue; Yasuyuki Agari; Yoshiaki Morisada; Masami Sugioka; Motohiro Tanaka; Takashi Takeuchi; Jun-ichi Tani; Masakazu Kawahara; Yukio Makino

2011-01-01

191

Solid\\/liquid phase-change heat transfer around two horizontal, vertically spaced cylinders -- An experimental study on the effect of density inversion of water  

Microsoft Academic Search

Solid\\/liquid phase-change heat transfer around cylinders occurs in many systems including latent-heat thermal-energy storage systems. In such systems, interactions of the heat transfer around the cylinders is often observed. Although several studies have reported on the heat transfer around a single cylinder and two or more cylinders, there have been no systematic studies to examine the effect of initial water

Kengo Sasaguchi; Koji Kusano; Hideaki Kitagawa

1995-01-01

192

Atomic Force Microscopy of Physical and Chemical Processes at the Solid-Liquid Interface  

NASA Astrophysics Data System (ADS)

This thesis describes research using atomic force microscopy (AFM) to study dynamics of solid surfaces in contact with liquids. Specifically, three applications are described: electrochemistry (Chapters 1-3), crystal growth (Chapters 4 and 5), and biomineralization (Chapter 6). Chapter 1 shows the feasibility of using AFM to image metal atoms in liquid, which sets the stage for high -resolution electrochemistry. Chapter 2 describes methods to convert the standard AFM liquid cell into an electrochemical cell and shows images of a gold electrode during oxidation/reduction cycling. Chapter 3 follows an electroplating cycle, wherein copper is deposited from electrolyte onto a gold electrode and then stripped off. The surface lattice is shown to change from that of bulk gold to bulk copper during plating, and back to bulk gold after stripping. Moreover, the first monolayer of copper--which deposits at an "underpotential", before the bulk deposition--is shown to have a lattice which differs from the bulk and is electrolyte dependent. Like electrochemistry, the study of crystal growth is also perfectly suited to a surface technique such as AFM. AFM makes it possible to image "elemental steps" (i.e., steps one unit cell thick) on a single crystal and quantify their motion during growth and dissolution. This is illustrated for the inorganic crystal calcite (Chapter 4) and the more fragile organic crystal L-leucine (Chapter 5). In both cases it is shown that step speed is independent of spacing between steps, indicating that motion occurs by direct interaction of the step-site molecules with the solvent. Chapter 5 also describes techniques for growing and imaging organic crystals. Living organisms also use crystal growth, modified by inorganic and organic additives, to grow mineralized structures such as bones, teeth and seashells. In Chapter 6, AFM reveals the three-dimensional structure of the nacreous or pearly layer of mollusc shells by slowly etching away successive mineral layers (in weak acid) while imaging. Etch figures on the mineral (aragonite) are correlated with crystallographic directions, revealing overall crystalline order on large scans. In bivalves, this order is observed both laterally across the layer and vertically between layers, whereas gastropod nacre is observed to be ordered only vertically.

Manne, Srinivas

193

Detailed monitoring of two biogas plants and mechanical solid-liquid separation of fermentation residues.  

PubMed

The Austrian "green electricity act" (Okostromgesetz) has led to an increase in biogas power plant size and consequently to an increased use of biomass. A biogas power plant with a generating capacity of 500 kW(el) consumes up to 38,000 kg of biomass per day. 260 ha of cropland is required to produce this mass. The high water content of biomass necessitates a high transport volume for energy crops and fermentation residues. The transport and application of fermentation residues to farmland is the last step in this logistic chain. The use of fermentation residues as fertilizer closes the nutrient cycle and is a central element in the efficient use of biomass for power production. Treatment of fermentation residues by separation into liquid and solid phases may be a solution to the transport problem. This paper presents detailed results from the monitoring of two biogas plants and from the analysis of the separation of fermentation residues. Furthermore, two different separator technologies for the separation of fermentation residues of biogas plants were analyzed. The examined biogas plants correspond to the current technological state of the art and have designs developed specifically for the utilization of energy crops. The hydraulic retention time ranged between 45.0 and 83.7 days. The specific methane yields were 0.40-0.43 m(3)N CH(4) per kg VS. The volume loads ranged between 3.69 and 4.00 kg VS/m(3). The degree of degradation was between 77.3% and 82.14%. The screw extractor separator was better suited for biogas slurry separation than the rotary screen separator. The screw extractor separator exhibited a high throughput and good separation efficiency. The efficiency of slurry separation depended on the dry matter content of the fermentation residue. The higher the dry matter content, the higher the proportion of solid phase after separation. In this project, we found that the fermentation residues could be divided into 79.2% fluid phase with a dry matter content of 4.5% and 20.8% solid phase with a dry matter content of 19.3%. Dry matter, volatile solids and carbon, raw ash and phosphate--in relation to the mass--accumulated strongly in the solid phase. Nitrogen and ammonia nitrogen were slightly enriched in the solid phase. Only the potassium content decreased slightly in the solid phase. PMID:19480948

Bauer, Alexander; Mayr, Herwig; Hopfner-Sixt, Katharina; Amon, Thomas

2009-02-06

194

A comparative study of anaerobic digestion of food waste in a single pass, a leachate recycle and coupled solid/liquid reactors.  

PubMed

A single pass reactor (R1), a leachate recycle reactor (R2) and a coupled solid/liquid bioreactor (R3-Rm) for anaerobic digestion of food waste were comparatively investigated in terms of digestion process and treatment efficiency. The coupled solid/liquid bioreactor is an enhanced two-phase system and distinctive from a traditional two-phase process with an upflow anaerobic sludge blanket (UASB) reactor as the methanogenic phase and a circulation of treated leachate between the acidification and methanogenic phases. In comparison with R1 and R2, R3-Rm enhanced the digestion process and increased the methane content of biogas. 100% of the R3-Rm methane yield was from the methanogenic phase with average methane content of 71%. The significant enhancement was also confirmed by the removal of 79% of total organic carbon (TOC), 60% of volatile solids (VS) and 80% of total COD in 12 days running of R3-Rm. However, no active methane fermentation was detected in R1 and R2 during 60 days operation. The results in this laboratory-scale study show that the rapid accumulation of volatile fatty acids (VFAs) due to the rapid acidification of food waste inhibits the development of effective methane fermentation in single pass and leachate recycle reactors. The coupled solid/liquid bioreactor is more efficient in converting food waste into methane and carbon dioxide. PMID:12578212

Xu, H L; Wang, J Y; Zhang, H; Tay, J H

2003-01-01

195

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

2011-04-25

196

Des orphelins de la JAC aux enfants perdus des parcours individuels  

Microsoft Academic Search

[fre] En France, en 1966, la politique de la formation professionnelle a été organisée en fonction d'un public bien précis : les jeunes exploitants familiaux. Elle a été ensuite étendue aux femmes, aux salariés, aux jeunes chômeurs. A l'heure actuelle, la décentralisation des décisions pose des problèmes de cohérence au niveau national et de priorité en fonction de la CEE.

Jean-François Chosson

1987-01-01

197

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

NASA Astrophysics Data System (ADS)

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

Waner, Mark Joseph

198

Protein oligomerization induced by oleic acid at the solid-liquid interface--equine lysozyme cytotoxic complexes.  

PubMed

Protein oligomeric complexes have emerged as a major target of current research because of their key role in aggregation processes in living systems and in vitro. Hydrophobic and charged surfaces may favour the self-assembly process by recruiting proteins and modifying their interactions. We found that equine lysozyme assembles into multimeric complexes with oleic acid (ELOA) at the solid-liquid interface within an ion-exchange chromatography column preconditioned with oleic acid. The properties of ELOA were characterized using NMR, spectroscopic methods and atomic force microscopy, and showed similarity with both amyloid oligomers and the complexes with oleic acid and its structural homologous protein alpha-lactalbumin, known as human alpha-lactalbumin made lethal for tumour cells (HAMLET). As determined by NMR diffusion measurements, ELOA may consist of 4-30 lysozyme molecules. Each lysozyme molecule is able to bind 11-48 oleic acids in various preparations. Equine lysozyme acquired a partially unfolded conformation in ELOA, as evident from its ability to bind hydrophobic dye 8-anilinonaphthalene-1-sulfonate. CD and NMR spectra. Similar to amyloid oligomers, ELOA also interacts with thioflavin-T dye, shows a spherical morphology, assembles into ring-shaped structures, as monitored by atomic force microscopy, and exerts a toxic effect in cells. Studies of well-populated ELOA shed light on the nature of the amyloid oligomers and HAMLET complexes, suggesting that they constitute one large family of cytotoxic proteinaceous species. The hydrophobic surfaces can be used profitably to produce complexes with very distinct properties compared to their precursor proteins. PMID:19594832

Wilhelm, Kristina; Darinskas, Adas; Noppe, Wim; Duchardt, Elke; Mok, K Hun; Vukojevi?, Vladana; Schleucher, Jürgen; Morozova-Roche, Ludmilla A

2009-07-07

199

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

NASA Astrophysics Data System (ADS)

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

Derose, James Anthony

200

Optimization of solid-liquid extraction of resveratrol and other phenolic compounds from milled grape canes (Vitis vinifera).  

PubMed

Optimization of the solid-liquid extraction conditions for trans-resveratrol, trans--viniferin, ferulic acid, and total phenolics from milled grape canes has been investigated. The temperature and ethanol concentration were found to be major process variables for all responses, whereas the solvent to solid ratio was found not to be significant for any of the responses studied. The yields of trans-resveratrol, trans--viniferin, and total phenolics increased with increasing temperature. Maximum yields of trans-resveratrol (4.25 mg/g dw), trans--viniferin (2.03 mg/g), and total phenolics (9.28 mg/g dw) were predicted from the combination of a moderate ethanol concentration (50-70%) and the highest temperature (83.6 degrees C), whereas an ethanol concentration of 35% at the lowest temperature studied (16.4 degrees C) was optimal for the extraction of ferulic acid (1.05 mg/g dw). Effective diffusivity values of resveratrol in the solid phase, D eff for different extraction conditions, were calculated by fitting the experimental results to a model derived from the Fick's second law. Effective diffusivity of resveratrol in the solid phase varied from 3.1 x 10 (-13) to 26.6 x 10 (-13) m (2) s (-1) with changing extraction conditions. The increase in effective diffusivity of resveratrol was observed with increasing temperature, and the highest predicted level was obtained when using 54% ethanol/water mixture at 83.6 degrees C. The increase in ethanol concentration exhibited the favorable effect up to 50-55%, thereafter effective diffusivity decreased with a further increase in concentration. PMID:18636680

Karacabey, Erkan; Mazza, Giuseppe

2008-07-16

201

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

Microsoft Academic Search

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\\u000a auxin-responsive Aux\\/IAA genes, termed FaAux\\/IAA1 and FaAux\\/IAA2 respectively, were isolated and

Du-juan LiuJian-ye; Jian-ye Chen; Wang-jin Lu

2011-01-01

202

Comparison of lab-scale and pilot-scale hybrid anaerobic solid–liquid systems operated in batch and semi-continuous modes  

Microsoft Academic Search

The hybrid anaerobic solid–liquid (HASL) system was developed for food waste bioconversion. Lab-scale and pilot-scale HASL systems were operated in batch and semi-continuous modes. High efficiencies for conversion of food waste into biogas were shown for both the lab-scale and pilot-scale HASL systems. Semi-continuous mode of HASL system was more effective than batch process. Methane production was 0.49ll?1day?1 and 0.71ll?1day?1

J. Y. Wang; H. Zhang; O. Stabnikova; J. H. Tay

2005-01-01

203

Etude Experimentale et Modelisation des Equilibres Solide—Liquide du Systeme Binaire H 2 O—UO 2 (NO 3 ) 2  

Microsoft Academic Search

The binary system H2O—UO2(NO3)2 was studied by solubility measurements and constant heat flow thermal analysis. Temperature and composition of the eutectic transformation between ice and uranyl nitrate hexahydrate were accurately defined. A new hydrate with 24 molecules of water decomposes at –21°C according to the peritectoid reaction2(NO3)2·24H2O> 2(NO3)2·6H2O> + 182O>The quasi-ideal model was applied to the solid—liquid equilibria, using the

R. Tenu; S. Gentil; S. Baudu; J. J. Counioux

1999-01-01

204

Tourisme et développement local : une application aux clusters de tourisme  

Microsoft Academic Search

<\\/titre> In this paper we consider the tourism cluster as an option of territorial development. Firstly, we point out the genesis of the concept of cluster and its alternative forms. Secondly, we present the specificities of the tourism cluster. Finally, we propose a conceptual framework of the tourism cluster in which the governance appears to be a key component of

Nathalie Fabry; Sylvain Zeghni

2012-01-01

205

Application de la technique du SCIDAR généralisé aux étoiles simples  

NASA Astrophysics Data System (ADS)

Nous exposons ici une nouvelle technique de caractérisation de la turbulence optique à partir de la scintillation des étoiles simples dans un plan conjugué de l'atmosphère. Cette technique permet de retrouver, pour chaque couche turbulente, la vitesse horizontale, l'écart-type des fluctuations de cette vitesse, l'altitude et enfin l'intégrale de la constante de structure de l'indice de réfraction Cn2(h)?h sur l'épaisseur de la couche. Les résultats obtenus sur étoile simple sont tangibles et au moins d'aussi bonne qualité que ceux obtenus par les autres méthodes. Pour citer cet article : A. Habib et al., C. R. Physique 6 (2005).

Habib, Abdelfettah; Vernin, Jean; Benkhaldoun, Zouhair

2005-04-01

206

Hémorrhéologie et cardiologie. Concept, physiopathologie, applications aux affections cardiologiques  

Microsoft Academic Search

The discovery that the blood and the vessel wall constitute a single organ, i.e., that the content definitely influences the container - which is the main object of the haemorrheology - is attributable to A.L. Copley (1910-1992). Due to driving forces, blood flow organizes itself as concentric layers (laminar flow) shearing over each other. Such a shear stress is stronger

M.-R. Boisseau

2005-01-01

207

Hémorhéologie clinique. Concept, physiopathologie et applications aux maladies vasculaires  

Microsoft Academic Search

The discovery that the blood and the vessel wall constitute a single organ, i.e, that the content definitely influences the container - which is the main object of the hoemorheology - is attributable to A.L. Copley (1910-1992). Due to driving forces, blood flow organizes itself as concentric layers (laminar flow) shearing over each other. Such a shear stress is stronger

M.-R. Boisseau

2004-01-01

208

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

209

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

210

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

PubMed

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

Yang, Hung-Ming; Chu, Wei-Ming

2013-08-13

211

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

212

Évaluation de la performance péréquatrice des concours financiers de l'État aux communes  

Microsoft Academic Search

[fre] Évaluation de la performance péréquatrice des concours financiers de l’État aux communes . . Les 36 600 communes françaises sont loin de pouvoir offrir aux résidents ou aux entreprises qu’elles accueillent le même niveau de services collectifs de proximité pour un effort fiscal donné. Leurs «pouvoirs d’achat en termes de consommations collectives» varient dans des proportions considérables. D’une part,

Guy Gilbert; Alain Guengant

2004-01-01

213

Des furoncles r?sistants aux antibiotiques: penser ? 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.

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

2013-01-01

214

Accès aux services de santé parmi les immigrants au Canada  

Microsoft Academic Search

RésuméRésumé Il est important de répondre aux besoins en soins de santé des populations immigrantes du fait de leur nombre élevé, soit, présentement, environ 20 % de la population canadienne née à l’étranger, et dont on prévoit que les taux augmenteront avec le temps, si cette tendance persiste, ce qui rend la situation de plus en plus difficile. L’accessibilité des

Lydie A. Lebrun

2010-01-01

215

Local Atomic Order in the Melt and Solid-Liquid Interface Effect on the Growth Kinetics in a Metallic Alloy Model  

NASA Astrophysics Data System (ADS)

We illustrate for a solid-liquid interface how local atomic order in a metallic melt (NiZr) transforms into a massive in-plane ordering at the surface of a crystal (bcc Zr) when commensurability is given between the solute-centered clusters of the melt and the periodic potential of the crystalline surface for a given orientation. Linking molecular dynamics simulation to phase-field modeling allows us to estimate quantitatively the influence of the surface effect on the growth kinetics. This study sheds new light on the relation between the undercooling ability (e.g., in the case of glass-forming alloys) and the pronounced local order in the melt.

Guerdane, M.; Teichler, H.; Nestler, B.

2013-02-01

216

Performance characteristics of a capacitive mass flowmeter in a coal-oil slurry at the ANL Solid/Liquid Test Facility  

SciTech Connect

This paper describes the performance of the Argonne National Laboratory (ANL) capacitive flowmeter, a nonintrusive flow instrument with no moving parts, in measuring particle velocity and particle concentration during a series of coal-oil slurry tests at the ANL Solid-Liquid Test Facility (SLTF). The experiment measured mass flow by the capacitive flowmeter in a coal-oil slurry for particle velocities and coal concentrations ranging respectively from 0.4 to 3.7 m/s and 0 to 60 wt % under controlled and reproducible conditions. Measured results, with the capacitive flowmeter located in a vertical pipe run, are compared with the SLTF flow calibration facilities. It is demonstrated that the capacitive flowmeter successfully measured the average slurry density and provided a measure of the slurry velocity, by using the cross-correlation method, for all coal concentrations with several electrode configurations.

Bobis, J.P.; Brewer, W.E.; Raptis, A.C.

1984-01-01

217

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

PubMed

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

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

2009-04-28

218

Numerical investigation of solid-liquid two phase flow in a non-clogging centrifugal pump at off-design conditions  

NASA Astrophysics Data System (ADS)

The solid-liquid two-phase flow fields in the non-clogging centrifugal pump with a double-channel impeller have been investigated numerically for the design condition and also off-design conditions, in order to study the solid-liquid two-phase flow pattern and non-clogging mechanism in non-clogging centrifugal pumps. The main conclusions include: The sand volume fraction distribution is extremely inhomogeneous in the whole flow channel of the pump at off-design conditions. In the impeller, particles mainly flow along the pressure surface and hub; In the volute, particles mainly accumulate in the region near to the exit of volute, the largest sand volume fraction is observed at the tongue, and a large number of particles collide with volute wall and exit the volute after circling around the volute for several times. When the particle diameter increases, particles tend to accumulate on the pressure side of the impeller, and more particles crash with the pressure side of the blade. And larger sand volume fraction gratitude is also observed in the whole flow channel of the pump. With the decrease of the inlet sand volume fraction, particles tend to accumulate on the suction side of the blade. Compared with the particle diameter, the inlet sand volume fraction has less influence on the sand volume fraction gratitude in the whole channel of the pump. At the large flow rate, the minimum and maximum sand volume fraction in the whole flow channel of the model pump tends to be smaller than that at the small flow rate. Thus, it is concluded that the water transportation capacity increases with the flow rate. This research will strengthen people's understanding of the multiphase flow pattern in non-clogging centrifugal pumps, thus provides a theoretical basis for the optimal design of non-clogging centrifugal pumps.

Zhao, B. J.; Huang, Z. F.; Chen, H. L.; Hou, D. H.

2012-11-01

219

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

220

Interferometric probing of rapid vaporization at a solid–liquid interface induced by pulsed-laser irradiation  

Microsoft Academic Search

In situ monitoring of rapid vaporization process on a submicron length scale is essential for understanding the phenomena induced by pulsed-laser heating of solid surfaces in contact with liquids. A number of laser-processing applications including steam laser cleaning and liquid-assisted material ablation take advantage of enhanced acoustic excitation in the explosive vaporization process. In this paper, a novel technique based

Dongsik Kim; Hee K. Park; Costas P. Grigoropoulos

2001-01-01

221

Kinetics of swelling\\/shrinking rearrangement of a self-aggregated nanohydrogel at solid\\/liquid interfaces  

Microsoft Academic Search

The hydrogel nanoparticles (nanohydrogels) have great potentials in numerous biomedical applications. Biomembrane-mimetic self-assemble nanohydrogel MCn (n repeated 2-methacryloyloyloxyethyl phosphoryl choline grafted cholesteryl group-bearing pullulan) was designed. In order to mimic the interfacial responses of fibrinogen at the hydrophobic\\/hydrophilic surfaces, MCn molecules were controlled by the chain length of the decorated MPC in term(s) of n?=?0, 6.2, 14.3 and 180, respectively.

Ge Qiang; Imshik Lee

2011-01-01

222

A test of the substitution hypothesis: An analysis of urban and rural trends in solid/liquid poisoning suicides in Taiwan.  

PubMed

Taiwan experienced both a significant decrease and a significant increase in the suicide rate during the period 1986-1999, which provides a unique opportunity to examine the substitution hypothesis in suicide research: that is, whether a reduction in the use of a certain method of suicide would be offset by a parallel increase in the use of other methods. We also explored whether such method substitution, if it existed, differed across urban and rural settings. Data on age-, sex-, method-, and urban-/rural-specific suicide rates for the period 1986-1999 in Taiwan were obtained and the year of 1993 is found to be the inflection point. We analyzed using Poisson regression to estimate the average annual percentage change (AAPC) for periods of decline (1986-1993) and increase (1993-1999) in suicides. The rapid decline in suicide by solid/liquid poisoning (mostly using pesticides) during a period of accelerated economic development (1986-1999) in Taiwan was found to be associated with the increased use of alternative methods. An interaction model found a marked decrease in solid/liquid poisoning suicide in both urban and rural Taiwan over the period of decline (1986-1993). The extent of the decrease was greater in rural areas but was accompanied by a rise in the use of several other suicide methods. However, the net effect was still a marked reduction in the suicide rate. A general increase in suicide among all age groups, for all methods, in both rural and urban settings, and for both sexes was found during the period when the suicide rate increased (1993-1999). We conclude that restricting access to the means of pesticide suicides reduces not only the method-specific suicide rate but also the overall suicide rate; nonetheless, suicide method substitution is not an all-or-nothing phenomenon. Stratified analyses by geographical (i.e. urban/rural) area can help to disentangle the patterns in each subgroup, which will improve our understanding of the phenomenon and make suicide prevention efforts more focused and effective. PMID:24034950

Chen, Ying-Yeh; Kwok, Chi-Leung; Yip, Paul S F; Wu, Kevin Chien-Chang

2013-07-13

223

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

SciTech Connect

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

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

1991-03-01

224

Facile synthesis of PbSe hollow nanostructure assemblies via a solid/liquid-phase chemical route and their electrogenerated chemiluminescence properties.  

PubMed

Spherical PbSe hollow nanostructure assemblies (HNSAs) were synthesized by a simple one-pot solid/liquid-phase reaction in which solid KPbI(3)?2?H(2)O and SeO(2) are heated in oleic acid/dodecylamine/1-octadecene at 250?°C for 30?min. XRD analysis shows that the obtained product is cubic-phase PbSe and well crystallized. FESEM and TEM images reveal that the obtained spherical PbSe assemblies are made up of small, irregular, and fused hollow nanostructure building blocks. On the basis of temperature- and time-dependent investigations as well as control experiments, molten-salt corrosion of solid PbSe nanocrystal aggregates formed in situ during the high-temperature ripening stage is suggested to explain the formation of such novel assemblies. Moreover, when the reaction temperature is further increased to 280 or 320?°C with other conditions unchanged, cubic and orthorhombic mixed-phase PbSe HNSAs is generated. The obtained PbSe HNSAs exhibit excellent electrogenerated chemiluminescence (ECL) performance. Two strong and stable emission peaks at about -1.4 and +1.5?V (vs. Ag/AgCl) are observed. In particular, the ECL intensity is influenced by the crystal phase of PbSe. PMID:21351177

Han, Min; Li, Yanrong; Niu, Hongyan; Liu, Lili; Chen, Kunji; Bao, Jianchun; Dai, Zhihui; Zhu, Jianming

2011-02-23

225

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

226

Enhancement of anaerobic treatability of olive oil mill effluents by addition of Ca(OH)2 and bentonite without intermediate solid/liquid separation.  

PubMed

Previous work on the anaerobic treatment of olive oil mill effluents (OME) have shown: (a) lipids, even if more easily degraded than phenols, were potentially capable of inhibiting methanogenesis more strongly; (b) a pretreatment based on addition of Ca(OH)2 and bentonite removed lipids almost quantitatively; (c) preliminary biotreatability tests performed on the pretreated OME showed high bioconversion into methane at very low dilutions ratios, especially when the mixture (OME, Ca(OH)2 and bentonite) was fed to the biological treatment without providing an intermediate phase separation. This paper was directed towards two main aims: (a) to optimize pretreatment: the best results in terms of methane production were obtained by addition of Ca(OH)2 up to pH 6.5 and of 10 g L-1 of bentonite; (b) to evaluate the enhancement of anaerobic treatability of OME pretreated under optimized conditions in a lab-scale continuous methanogenic reactor fed with the substrate without intermediate solid/liquid separation: very satisfactory performances were obtained (at an organic load of 8.2 kg COD m-3 d-1 and at a dilution ratio of 1:1.5 total COD removal was 91%, biogas production was 0.80 g CH4 (as COD)/g tot. COD, lipids removal was 98%, phenols removal was 63%). The results confirm the double role played by bentonite (adsorption of the inhibiting substances and release of the adsorbed biodegradable matter in the methanogenic reactor). PMID:11443973

Beccari, M; Majone, M; Papini, M P; Torrisi, L

2001-01-01

227

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

228

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

229

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

USGS Publications Warehouse

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

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

1992-01-01

230

Prediction of conjugate heat transfer in a solid-liquid system: Inclusion of buoyancy and surface tension forces in the liquid phase  

SciTech Connect

Numerical predictions have been obtained for steady-state conjugate heat transfer in an open rectangular cavity. For the geometry considered, fluid motion is driven by augmenting buoyancy and surface tension forces. Predictions of the steady-state solid volume fraction and various solid thicknesses were obtained for a high Prandtl number fluid characterized by various Rayleigh and Marangoni (Ma) numbers. Due to numerical difficulties associated with large surface tension effects, a limited range of Ma was investigated (Ma {le} 250). The predictions show that surface tension induced flow can affect the solid geometry and, ultimately, freezing or melting rates. Specifically, the solid-liquid interface shape is altered, the steady-state solid volume fraction is decreased, and the solid thickness at the top surface is smaller, compared to the pure buoyancy-driven case. The dimensionless solid volume fraction and solid thicknesses are related to the governing dimensionless parameters of the problem. Finally, predictions are made for high Marangoni number flows (Ma > > 250) to demonstrate the potential governing influence of surface tension effects in phase-change systems.

Keller, J.R.; Bergman, T.L. (Univ. of Texas, Austin (United States))

1989-08-01

231

Solid partitioning and solid-liquid distribution of 210Po and 210Pb in marine anoxic sediments: roads of Cherbourg at the northwestern France.  

PubMed

A sequential extraction protocol has been used to determine the solid-phase partition of (210)Po and (210)Pb in anoxic marine sediment from the roads of Cherbourg (France) in the central English Channel. Measurements were also obtained in pore waters, in which (210)Po activities range between 1 and 20 mBq L(-1) and (210)Pb activities between 2.4 and 3.8 mBq L(-1), with highest activities in the topmost layer. These activities are higher than in seawater, suggesting that sediment act as a source of both (210)Po and (210)Pb for overlying water. The (210)Po profile in the pore waters is apparently correlated with those obtained for Fe, Mn and SO(4)(2)(-), suggesting an influence of early diagenetic processes on the (210)Po solid-liquid distribution. In the sediment, (210)Po is predominantly bound to organic matter or chromium reducible sulphides, and residuals (clay minerals and refractory oxides). Our results indicate that (210)Po is not significantly bound to AVS, i.e. acid volatile sulphides: bioturbation could play a role by the early redistribution of (210)Po bound to acid volatile sulphides in the sediment. (210)Po, (210)Pb and Pb exhibit differences in terms of distribution, probably due to a different mode of penetration in the sediment. This work provides information on solid and liquid distribution of (210)Po and (210)Pb in marine sediment. These data are very scarce in the literature. PMID:19631425

Connan, O; Boust, D; Billon, G; Solier, L; Rozet, M; Bouderbala, S

2009-07-23

232

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

Microsoft Academic Search

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

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

2007-01-01

233

Molecular Orientation of Enzymes Attached to Surfaces through Defined Chemical Linkages at the Solid-Liquid Interface.  

PubMed

The immobilization of enzymes on solid supports is widely used in many applications, including biosensors, antifouling coatings, food packaging materials, and biofuel cells. Enzymes tend to lose their activity when in contact with a support surface, a phenomenon that has been attributed to unfavorable orientation and (partial) unfolding. In this work, specific immobilization of 6-phospho-?-galactosidase (?-Gal) on a self-assembled monolayer (SAM) containing maleimide end groups and oligo(ethylene glycol) spacer segments was achieved through a unique cysteinyl residue. A systematic means to characterize the interfacial orientation of immobilized enzymes has been developed using a combination of sum frequency generation vibrational spectroscopy and attenuated total reflectance FTIR-spectroscopy. The possible orientations of the immobilized ?-Gal were determined and found to be well-correlated with the tested activity of ?-Gal. This study will impact the development of an increasingly wide range of devices that use surface-immobilized enzymes as integral components with improved functions, better sensitivity, enhanced stability, and longer shelf life. PMID:23883344

Liu, Yuwei; Ogorzalek, Tadeusz L; Yang, Pei; Schroeder, McKenna M; Marsh, E Neil G; Chen, Zhan

2013-08-15

234

Symetries et integrabilite des equations aux differences finies  

NASA Astrophysics Data System (ADS)

La présente thèse porte sur l'étude des symétries et des propriétés d'intégrabilité des équations aux différences finies. Dans le chapitre 1, le groupe de symétrie ponctuelle d'un système couplé à deux équations différentielles aux différences est étudié. On montre que dans certains cas, la dimension du groupe peut être infinie. Les équations peuvent décrire l'interaction de deux longues chaînes moléculaires, chacune étant composée d'atomes d'un même type. Dans le chapitre 2, une classe de théories de champs avec interaction exponentielle est introduite. L'interaction dépend de deux matrices de ``couplage'' et est suffisamment générale pour inclure toutes les théories de champs de Toda existant dans la littérature. Les symétries de Lie ponctuelles sont obtenues pour les cas où l'on a un nombre fini, infini ou semi-infini de champs. Une attention spéciale est accordée à la présence de l'invariance conforme. Dans le chapitre 3, nous procédons à la classification et à l'étude d'équations linéarisables. Nous examinons tout d'abord l'équation de Gambier continue qui contient, comme réductions, toutes les équations de deuxième ordre intégrables par linéarisation. Nous introduisons par la suite la forme discrète de cette équation et obtenons les conditions d'intégrabilité à l'aide du confinement des singularités. Nous étudions aussi les différentes réductions du cas discret. De plus, nous obtenons des transformations de Schlesinger pour les équations de Gambier discrète et continue. Dans la dernière partie du chapitre, nous étudions une famille d'équations discrètes du deuxième ordre incluant des équations résolubles par linéarisation. Plusieurs cas intégrables sont obtenus. Dans le cas discret, l'étude de l'intégrabilité est faite à l'aide du confinement des singularités. Dans le chapitre 4, nous étudions un autre critère d'intégrabilité: l'entropie algébrique. Nous montrons que les résultats obtenus avec ce critère pour les équations linéarisables sont les mêmes que ceux obtenus avec le confinement des singularités. Nous obtenons de plus une méthode algorithmique pour la détection de la linéarisabilité. Le chapitre 5 est consacré à l'étude d'équations du troisième ordre. Nous obtenons des équations intégrables par des couplages d'équations du premier et du deuxième ordre. Les équations continues sont étudiées à l'aide de l'analyse de Painlevé et le confinement des singularités est utilisé dans le cas discret.

Lafortune, Stephane

2000-09-01

235

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

SciTech Connect

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

Prof. P. Somasundaran

2002-09-30

236

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

PubMed Central

Multilevel interactions of the plant hormones ethylene and auxin coordinately and synergistically regulate many aspects of plant growth and development. This study isolated the AUXIN RESISTANT1 (AUX1) allele aux1rcr1 (RCR1 for REVERSING CTR1-10 ROOT1) that suppressed the root growth inhibition conferred by the constitutive ethylene-response constitutive triple response1-10 (ctr1-10) allele. The aux1rcr1 mutation resulted from an L126F substitution at loop 2 of the plasma membrane-associated auxin influx carrier protein AUX1. aux1rcr1 and the T-DNA insertion mutant aux1-T were both defective in auxin transport and many aspects of the auxin response. Unexpectedly, expression of the auxin-response reporter DR5:GUS in the root apex was substantially prevented by the aux1rcr1 but not the aux1-T mutation, even in the presence of the wild-type AUX1 allele. Following treatment with the synthetic auxin 1-naphthaleneacetic acid (NAA), DR5:GUS expression in aux1rcr1 and aux1-T occurred mainly in the root apex and mature zone. NAA-induced DR5:GUS expression in the root apex was markedly prevented by ethylene in genotypes with aux1rcr1 but not in aux1-T genotypes and the wild type. The effect of aux1rcr1 on DR5:GUS expression seemed to be associated with AUX1-expressing domains. Green fluorescence protein-fused aux1rcr1 was localized in the cytoplasm and probably not to the plasma membrane, indicating important roles of the Lys126 residue at loop 2 in AUX1 targeting. The possible effects of aux1rcr1 on DR5:GUS expression are discussed.

Wen, Chi-Kuang

2013-01-01

237

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

PubMed

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

Yu, Jing; Wen, Chi-Kuang

2013-01-04

238

Membrane filtration of the liquid fraction from a solid-liquid separator for swine manure using a cationic polymer as flocculating agent.  

PubMed

The liquid fraction from a solid-liquid separator for swine manure, which used a cationic polymer to promote particle flocculation, was processed by one nanofiltration and two reverse osmosis spiral-wound membranes. Eight different liquid fraction batches (750 to 1750 L) were concentrated at volumetric concentration ratios (VCRs, initial to final volumes) ranging from 2.3 to 4.2. Membrane fouling intensity was highly variable, as water flux recovery after concentration cycles ranged from 13% to 88%. The most severe fouling was caused by a liquid fraction that had relatively low suspended solids (SS) (774 mg/L) and was concentrated at a low VCR of 2.6. Raw manure collected the same day also contained low SS, suggesting that fewer sites were available for polymer adsorption and thus more polymer remained in the liquid. However, because of the high opacity of the samples, residual polymer could not be detected in any feed or concentrate samples. Fouling was not totally irreversible as over 97% of membrane flux could be recovered by cleaning with acidic and alkaline solutions. Further tests with spiked liquid fractions indicated that fouling due to residual polymer in solution started to occur at a polymer concentration of 3 and 11 mg/L in initial and concentrated effluents, respectively. If a cationic polymer is used to pretreat manure, the amount of added polymer would have to be closely related to SS content as opposed to manure volume, in order to leave very little residual polymer in solution. PMID:23837317

Masse, L; Mondor, M; Dubreuil, J

239

A novel extraction technique based on carbon nanotubes reinforced hollow fiber solid/liquid microextraction for the measurement of piroxicam and diclofenac combined with high performance liquid chromatography.  

PubMed

A novel design of carbon nanotubes reinforced hollow fiber solid/liquid phase microextraction (CNTs-HF-SLPME) was developed to determine piroxicam and diclofenac in different real water samples. Functionalized multi-walled carbon nanotubes (MWCNTs) were held in the pores of hollow fiber with sol-gel technology. The pores and lumen of carbon nanotubes reinforced hollow fiber were subsequently filled with a ?L volume of organic solvent (1-octanol), and then the whole assembly was used for the extraction of the target analytes in direct immersion sampling mode. The target analytes were extracted from the sample by two extractants, one of which is organic solvent placed inside the pores and lumen of hollow fiber and the other one is CNTs held in the pores of hollow fiber. After extraction, the analytes were desorbed in acetonitrile and analyzed using high performance liquid chromatography. This novel extraction mode showed more excellent extraction performance in comparison with conventional hollow fiber liquid microextraction (without adding CNTs) and carbon nanotubes reinforced hollow fiber solid microextraction (CNTs held in the pores of hollow fiber, but no organic solvents placed inside the lumen of hollow fiber) under the respective optimum conditions. This method provided 47- and 184-fold enrichment factors for piroxicam and diclofenac, respectively, good inter-fiber repeatability and batch-to-batch reproducibility. Linearity was observed in the range of 20-960 ?g L(-1) for piroxicam, and 10-2560 ?g L(-1) for diclofenac, with correlation coefficients of 0.9985 and 0.9989, respectively. The limits of detection were 4.58 ?g L(-1) for piroxicam and 0.40 ?g L(-1) for diclofenac. PMID:23141323

Song, Xin-Yue; Shi, Yan-Ping; Chen, Juan

2012-09-03

240

Strong magnetic field effects on solid-liquid and particle-particle interactions during the processing of a conducting liquid containing non-conducting particles.  

PubMed

The behavior of micrometer-sized weak magnetic insulating particles migrating in a conductive liquid metal is of broad interest during strong magnetic field processing of materials. In the present paper, we develop a numerical method to investigate the solid-liquid and particle-particle interactions by using a computational fluid dynamics (CFDs) modeling. By applying a strong magnetic field, for example, 10 Tesla, the drag forces of a single spherical particle can be increased up to around 15% at a creeping flow limit. However, magnetic field effects are reduced when the Reynolds number becomes higher. For two identical particles migrating along their centerline in a conductive liquid, both the drag forces and the magnetic interaction will be influenced. Factors such as interparticle distance, Reynolds number and magnetic flux density are investigated. Shielding effects are found from the leading particle, which will subsequently induce a hydrodynamic interaction between two particles. Strong magnetic fields however do not appear to have a significant influence on the shielding effects. In addition, the magnetic interaction forces of magnetic dipole-dipole interaction and induced magneto-hydrodynamic interaction are considered. It can be found that the induced magneto-hydrodynamic interaction force highly depends on the flow field and magnetic flux density. Therefore, the interaction between insulating particles can be controlled by applying a strong magnetic field and modifying the flow field. The present research provides a better understanding of the magnetic field induced interaction during liquid metal processing, and a method of non-metallic particles manipulation for metal/ceramic based materials preparation may be proposed. PMID:22443967

Sun, Z H I; Zhang, X; Guo, M; Pandelaers, L; Vleugels, J; Van der Biest, O; Van Reusel, K; Blanpain, B

2012-03-06

241

Preparation of ethylenediamine-anchored cellulose and determination of thermochemical data for the interaction between cations and basic centers at the solid/liquid interface.  

PubMed

Cellulose was first modified with thionyl chloride, giving 99% substitution at C6, and then reacted with ethylene-1,2-diamine to produce 6-(2'-aminoethylamino)-6-deoxy-cellulose. From the 8.5% of nitrogen incorporated in the polysaccharide backbone, the amount of ethylene-1,2-diamine anchored per gram of modified cellulose was determined to be 3.03+/-0.01mmol. This chemically immobilized surface was characterized by FTIR, TG, (13)C NMR, and SEM techniques. The available basic nitrogen centers covalently bonded to the biopolymer skeleton were studied for copper, cobalt, nickel, and zinc adsorption from aqueous solutions and the respective thermal adsorption effects were determined by calorimetric titration. The ability to adsorb cations gave a capacity order of Co(2+)>Cu(2+)>Zn(2+)>Ni(2+) with affinities of 1.91+/-0.07, 1.32+/-0.07, 1.31+/-0.02, and 1.08+/-0.04mmol/g, respectively. The net thermal effects obtained from calorimetric titration measurements were adjusted to a modified Langmuir equation and the enthalpy of the interaction was calculated to give the following exothermic values: -20.8+/-0.05, -11.72+/-0.03, -7.32+/-0.01, and -6.27+/-0.02kJ/mol for Co(2+), Cu(2+), Zn(2+), and Ni(2+), respectively. With the exception of the entropic value for copper, the other thermodynamic data for these systems are favorable for cation adsorption from aqueous solutions at the solid/liquid interface, suggesting the use of this anchored biopolymer for cation removal from the environment. PMID:17022956

da Silva Filho, Edson C; de Melo, Júlio C P; Airoldi, Claudio

2006-10-04

242

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

243

Study of solid/liquid and solid/gas interfaces in Cu-isoleucine complex by surface X-ray diffraction  

NASA Astrophysics Data System (ADS)

The enzymes could be understood like structures formed by amino acids bonded with metals, which act as active sites. The research on the coordination of metal-amino acid complexes will bring light on the behavior of metal enzymes, due to the close relation existing between the atomic structure and the functionality. The Cu-isoleucine bond is considered as a good model system to attain a better insight into the characteristics of naturally occurring copper metalloproteins. The surface structure of metal-amino acid complex could be considered as a more realistic model for real systems under biologic working conditions, since the molecular packing is decreased. In the surface, the structural constrains are reduced, keeping the structural capability of surface complex to change as a function of the surrounding environment. In this work, we present a surface X-ray diffraction study on Cu-isoleucine complex under different ambient conditions. Cu(Ile)2 crystals of about 5 mm × 5 mm × 1 mm have been growth, by seeding method in a supersaturated solution, presenting a surface of high quality. The sample for the surface diffraction study was mounted on a cell specially designed for solid/liquid or solid/gas interface analysis. The Cu-isoleucine crystal was measured under a protective dry N2 gas flow and in contact with a saturated metal amino acid solution. The bulk and the surface signals were compared, showing different atomic structures. In both cases, from surface diffraction data, it is observed that the atomic structure of the top layer undergoes a clear structural deformation. A non-uniform surface relaxation is observed producing an inhomogeneous displacement of the surface atoms towards the surface normal.

Ferrer, Pilar; Rubio-Zuazo, Juan; Castro, German R.

2013-02-01

244

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

PubMed

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. 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. PMID:23848684

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

2013-06-20

245

Yokonolide B, a novel inhibitor of auxin action, blocks degradation of AUX/IAA factors.  

PubMed

Yokonolide B (YkB; also known as A82548A), a spiroketal-macrolide, was isolated from Streptomyces diastatochromogenes B59 in a screen for inhibitors of beta-glucoronidase expression under the control of an auxin-responsive promoter in Arabidopsis. YkB inhibits the expression of auxin-inducible genes as shown using native and synthetic auxin promoters as well as using expression profiling of 8300 Arabidopsis gene probes but does not affect expression of an abscisic acid- and a gibberellin A3-inducible gene. The mechanism of action of YkB is to block AUX/IAA protein degradation; however, YkB is not a general proteasome inhibitor. YkB blocks auxin-dependent cell division and auxin-regulated epinastic growth mediated by auxin-binding protein 1. Gain of function mutants such as shy2-2, slr1, and axr2-1 encoding AUX/IAA transcriptional repressors and loss of function mutants encoding components of the ubiquitin-proteolytic pathway such as axr1-3 and tir1-1, which display increased AUX/IAAs protein stability, are less sensitive to YkB, although axr1 and tir1 mutants were sensitive to MG132, a general proteasome inhibitor, consistent with a site of action downstream of AXR1 and TIR. YkB-treated seedlings displayed similar phenotypes as dominant AUX/IAA mutants. Taken together, these results indicate that YkB acts to block AUX/IAA protein degradation upstream of AXR and TIR, links a shared element upstream of AUX/IAA protein stability to auxin-induced cell division/elongation and to auxin-binding protein 1, and provides a new tool to dissect auxin signal transduction. PMID:12690101

Hayashi, Ken-ichiro; Jones, Alan M; Ogino, Kentaro; Yamazoe, Atsushi; Oono, Yutaka; Inoguchi, Masahiko; Kondo, Hirokiyo; Nozaki, Hiroshi

2003-04-09

246

La chirurgie des cancers de l’ovaire aux stades avancés: techniques et stratégies  

Microsoft Academic Search

\\u000a Résumé:\\u000a   La fréquence relative des cancers de l’ovaire aux stades avancés explique leur mauvais pronostic. Celui-ci ne peut être amélioré\\u000a que par une bonne sensibilité aux chimiothérapies actuelles (Carboplatine + Paclitaxel) et une réduction chirurgicale macroscopiquement\\u000a complète du volume tumoral. L’extension tumorale intra-abdominale étant très hétérogène, la complexité des interventions pour\\u000a parvenir à une exérèse complète est très variable. On

J. Dauplat; G. Le Bouedec; P. Gimbergues; T. Michy

2006-01-01

247

Mecanismos de Acción de las Auxinas y los Herbicidas Auxínicos  

NSDL National Science Digital Library

Se muestra como las auxinas y los herbicidas auxínicos pueden inducir respuestas celulares y se describe el transporte basípeto de las auxinas. También se muestra como los receptores de auxinas reconocen las auxinas y los herbicidas auxínicos, los cuales inducen entonces la transmisión y traducción de señales para activar varios genes; el papel de los productos de esos genes en las respuestas de las plantas es también mostrado.

248

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

249

A simple and rapid technique for recovery of 99mTc from low specific activity (n,gamma)99Mo based on solid-liquid extraction and column chromatography methodologies.  

PubMed

A simple and inexpensive method has been developed for the separation of (99m)Tc from (99)Mo produced from the neutron activation of (98)Mo by (98)Mo(n,gamma)(99)Mo nuclear reaction. The recovery of (99m)Tc was performed by solid-liquid extraction based on alumina column chromatography. The overall radiochemical yield for the complete separation of (99m)Tc was 85-97% (n=5). The separated Na[(99m)Tc]TcO(4) was of high radionuclidic, radiochemical and chemical purities. The method can be adopted for routine processing and use of (99m)Tc in radiopharmacy operations. PMID:20122663

Chattopadhyay, Sankha; Das, Sujata Saha; Barua, Luna

2009-10-03

250

Simultaneous C- and N-Alkylation of 2Oxo4,6-diaryl-1,2,3,4-tetrahydropyridine-3-carbonitrile Under Solid–Liquid Phase-Transfer Conditions  

Microsoft Academic Search

The alkylation of 2-oxo-4,6-diaryl-1,2,3,4-tetrahydropyridine-3-carbonitrile 1 has been carried out using different alkyl\\/arylating agents in solid–liquid phase-transfer catalysis conditions. The aim was to study the effect of steric hindrance offered by the aryl group in the sixth position of the pyridine ring on the ambient N- vs. O-alkylation ratio. Simultaneous C- and N-alkylation was encountered and confirmed by x-ray crystallography. Our

Hetal C. Shah; Vaishali H. Shah; Nirmal D. Desai

2010-01-01

251

Decommissioning of the nuclear licensed facilities at the Fontenay aux Roses CEA center  

Microsoft Academic Search

Available in abstract form only. Full text of publication follows: The French Atomic Energy Commission (CEA) center at Fontenay aux Roses (CEN-FAR) is the Commission's oldest center is located in the southern suburbs of Paris. It was opened on 26 March 1946 to host the first French nuclear reactor ZOE that went critical on 12 December 1946. The first laboratories

Michel Jeanjacques; Laurence Piketty; Nathalie Letuhaire; Lionel Mandard; Igor Meden; David Estivie; Jean Francois Boissonneau; Alain Fouquereau; Eric Pichereau; Cedric Binet

2007-01-01

252

Une évaluation de la qualité du cannabis à usage thérapeutique aux Pays-Bas  

Microsoft Academic Search

Depuis 2003, du cannabis à usage thérapeutique est délivré sur ordonnance dans les pharmacies aux Pays-Bas. La culture, la transformation et le conditionnement de la matière végétale sont réal- isés selon les normes pharmaceutiques et sont supervisés par le Bureau du Cannabis Médical (OMC). La qualité est garantie par des tests réguliers effectués par des laboratoires certifiés. Ce- pendant, un

Arno Hazekamp

2006-01-01

253

Point de référence et aversion aux pertes : quel intérêt pour les gestionnaires ?  

Microsoft Academic Search

Les notions de point de référence et d’aversion aux pertes sont deux éléments essentiels de la prospect theory, qui constitue à ce jour la théorie la plus reconnue concernant la représentation de la prise de décision individuelle dans le risque. L’objectif de cet article est de montrer comment ces notions peuvent être utilisées par les gestionnaires pour améliorer leur compréhension

Corina Paraschiv; Olivier L’Haridon

2009-01-01

254

Comprendre les representations du personnel soignant face aux infections nosocomiales au Clostridium difficile au Quebec pour mieux en promouvoir la sante.  

PubMed

Au cours des dernières années, la transmission des infections nosocomiales, notamment des infections à Clostridium difficile, est devenue une importante préoccupation au Québec. Pour éviter leur transmission, les experts recommandent notamment la formation du personnel. Dans cet article, nous décrivons la représentation que se font certaines catégories de personnel de la santé à propos des risques reliés à la transmission du Clostridium difficile et leur perception des messages de prévention, afin d'identifier des avenues permettant de contribuer à cette formation. Nous avons effectué 27 entrevues et 186 heures d'observation auprès d'infirmières, infirmières auxiliaires, préposés aux bénéficiaires et préposés à l'entretien sanitaire expérimentés, dans deux unités de soins de courte durée et deux de longue durée d'un hôpital à Montréal. Résultats : le personnel se préoccupe de la transmission du C difficile envers les patients et envers leurs propres familles davantage que des conséquences immédiates sur leur propre santé. Les pratiques pour éviter de transporter le microorganisme à leur maison sont décrites. Malgré l'application de mesures de prévention, certains participants pensent s'être contaminés et être porteurs sains du C difficile, qui persisterait dans leur organisme et pourrait s'activer s'ils sont affaiblis ou sous antibiotiques. Cette contamination surviendrait à cause de situations mettant en échec la prévention : les patients non diagnostiqués et les délais de diagnostic, un manque de formation sur les mesures de prévention et sur les mesures pratiques pour les appliquer et un manque d'information sur les produits désinfectants, ces deux dernières mesures affectant surtout les préposées aux bénéficiaires. Nous concluons sur la nécessité de prendre en compte les préoccupations du personnel dans les interventions éducatives ; de formations pratiques, adaptées au travail et sur le besoin d'information quant aux raisons de changements de produits. PMID:23986384

Seifert, Ana María; O'Neill, Michel

2013-09-01

255

A DFT study of the structures of Au(x) clusters on a CeO2(111) surface.  

PubMed

Studying the structures of metal clusters on oxide supports is challenging due to their various structural possibilities. In the present work, a simple rule in which the number of Au atoms in different layers of Au(x) clusters is changed successively is used to systematically investigate the structures of Au(x) (x=1-10) clusters on stoichiometric and partially reduced CeO(2)(111) surface by DFT calculations. The calculations indicate that the adsorption energy of a single Au atom on the surface, the surface structure, as well as the Au-Au bond strength and arrangement play the key roles in determining Au(x) structures on CeO(2)(111). The most stable Au(2) and Au(3) clusters on CeO(2)(111) are 2D vertical structures, while the most stable structures of Au(x) clusters (x>3) are generally 3D structures, except for Au(7). The 3D structures of large Au(x) clusters in which the Au number in the bottom layer does not exceed that in the top layer are not stable. The differences between Au(x) on CeO(2)(111) and Mg(100) were also studied. The stabilizing effect of surface oxygen vacancies on Au(x) cluster structures depends on the size of Au(x) cluster and the relative positions of Au(x) cluster and oxygen vacancy. The present work will be helpful in improving the understanding of metal cluster structures on oxide supports. PMID:22323361

Teng, Bo-Tao; Wu, Feng-Min; Huang, Wei-Xin; Wen, Xiao-Dong; Zhao, Lei-Hong; Luo, Meng-Fei

2012-02-09

256

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.

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

2012-01-01

257

The diageotropica mutation alters auxin induction of a subset of the Aux\\/IAA gene family in tomato  

Microsoft Academic Search

The diageotropica (dgt) mutation has been proposed to affect either auxin perception or responsiveness in tomato plants. It has previously been demonstrated that the expression of one member of the Aux\\/IAA family of auxin-regulated genes is reduced in dgt plants. Here, we report the cloning of ten new members of the tomato Aux\\/IAA family by PCR amplification based on conserved

Andreas Nebenführ; TJ White; Terri L. Lomax

2000-01-01

258

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

259

Alterations des fonctions de reproduction chez les souris males deficientes en recepteur aux estrogenes  

Microsoft Academic Search

Resume  La délétion du récepteur aux estrogènes (estrogen receptor knock out i.e ERKO) chez la souris mâle conduit à la stérilité\\u000a suite à une déficience de la gamétogenèse associée à des altérations du comportement sexuel. En fonction de l’âge, le développement\\u000a testiculaire est de plus en plus anormal et les cellules germinales dégénèrent. Les taux circulants de gonadotropines et de\\u000a testostérone

K. S. Korach; J. Lindzey

1998-01-01

260

Introduction générale aux Œuvres morales et politiques de Jean-Baptiste Say  

Microsoft Academic Search

Les textes présentés dans ce volume couvrent une période qui va de 1789 à 1832. De 22 ans à 65 ans, âge auquel il est mort, Jean-Baptiste Say n'a pas cessé de s'intéresser passionnément aux questions politiques de son temps. Il en a été un des acteurs, modeste à ses débuts, puis de plus en plus important, côtoyant les plus

André Tiran; Emmanuel Blanc

2003-01-01

261

DE L'ACCOMMODATION DES ENSEIGNANTS AUX EFFETS DES NOUVELLES POLITIQUES EDUCATIVES. UNE ETUDE DE CAS  

Microsoft Academic Search

Systèmes scolaires et identité professionnelle : un contexte mouvant Suite aux évolutions récentes des politiques éducat ives, les enseignants subissent un certain nombre de pressions. Si le métier n'en a jamais été exempt, loin de là, celles que l'on peut constater aujourd'hui sont notamment issues de l'éd ition régulière de nouvelles directives et prescriptions. Dans le cadre qui est le

Danièle Périsset

262

Chemical Composition and Geologic History of Saline Waters in Aux Vases and Cypress Formations, Illinois Basin  

Microsoft Academic Search

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

Ilham Demir; Beverly Seyler

1999-01-01

263

INVESTISSEMENTS FRANÇAIS AUX ETATS-UNIS, STRATÉGIES DE CROISSANCE EXTERNE ET RÉACTIONS DU MARCHÉ BOURSIER  

Microsoft Academic Search

Résumé : l'objectif de cet article est d'évaluer la réaction des marchés boursiers suite à l'annonce d'investissements directs par des entreprises françaises aux Etats-Unis. L'étude empirique se fonde sur une méthodologie d'étude d'événements, destinée à mesurer les rendements anormaux moyens et les rendements anormaux moyens cumulés, sur les cotations à la Bourse de Paris, associés à l'annonce d'acquisitions de firmes

Pierre-Xavier MESCHI; Emmanuel METAIS

264

The formation of orbital moments on iron impurities in Ag1 - xAux alloys  

Microsoft Academic Search

Using the high specificity and sensitivity of the in-beam perturbed gamma-ray angular distribution method, we have investigated the magnetic behavior of very dilute 54Fe probes in Ag1 - xAux alloys. The nuclear damping time and local susceptibility of Fe are found to depend strongly on its local environment, showing inhomogeneous line broadening as well as discrete magnetic responses due to

R. Kirsch; M. J. Prandolini; O. Beutler; W. D. Brewer; M. Gruyters; J. Kapoor; D. Riegel; H. Ebert; S. Frota-Pessôa

2002-01-01

265

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

266

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

267

The Morne Aux Diables volcano, Dominica, Lesser Antilles: A stratigraphic and petrologic study.  

NASA Astrophysics Data System (ADS)

Morne Aux Diables is a topographically distinct stratovolcano located at the northernmost end of the island of Dominica, Lesser Antilles. In 2007, observations were conducted, and over 3,000 digital photographs were taken, of the well-exposed sea cliffs around Dominica. These observations, together with photogeological analysis of approximately 500 of these digital photographs of sea cliffs around the northern part of Dominica, have significantly improved our understanding of the geology of Morne aux Diables volcano, which previously had been based on scattered land exposures. The photographs were used to identify genetic packages of strata related to volcanogenic events and trace them around large sectors of the volcano's flanks. Based on these new studies, together with previous data, Morne aux Diables appears to have undergone two periods of activity, an older period dated between 2.1-1.5 Ma and a younger period dated at around 50,000 years B.P. Deposits associated with the older cone-forming activity are primarily composed of block and ash flows and surges associated with Pelean-style activity. These can be subdivided into a number of sequences based on the presence of paleosols. Domes associated with these eruptions are found both in the central vent area as well as around the flanks of the volcano. The upper deposits in the sea cliffs on the eastern, northern and western flanks are a thick sequence of surges that have been provisionally correlated with a well-exposed sequence of semi-vesicular block and ash flows and surge deposits at Morne a Louis on the west coast. The presence of these surge deposits at the top of the sea cliffs suggests that the older period of activity ended with open-crater Asama-style eruptions. Following an extensive quiescent period, renewed Pelean-style activity produced valley-fill block and ash flow and surge deposits, exposed on both the eastern and western sides of the volcano, together with associated domes (both central and parasitic). Petrographic studies show that Morne Aux Diables volcano is composed of andesites and dacites with a mineral assemblage of plagioclase+augite±hypersthene with minor hornblende and quartz. Geochemically both the older and younger volcanic rocks show trends, especially in terms of alkalis, that are slightly lower and cross- cut from those shown by the other centers on Dominica. These stratigraphic and petrologic studies will help further elucidate the volcanic history of Morne aux Diables and allow a petrologic-stratigraphic model of its formation.

Daly, G. L.; Smith, A. L.; Rheubottom, A. N.; Fryxell, J. E.

2008-12-01

268

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

PubMed Central

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

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

2001-01-01

269

Scanning Tunnelling Microscopy and Molecular Modelling of Xanthine Monolayers Self-assembled at the Solid-Liquid Interface: Relevance to the Origin of Life  

Microsoft Academic Search

The development of scanning tunnelling microscopy (STM) has allowed examination of inorganic crystalline surfaces and their interactions with organic adsorbates with unparalleled resolution. As a novel technique in origin of life studies, the application of STM is detailed with particular attention paid to the methods employed in the analysis of organic monolayer structures. STM imaging and molecular modelling of self-assembled

Stephen J. Sowerby; George B. Petersen

1999-01-01

270

Relationships between Existence of Negative Group Velocity and Physical Parameters of Materials for Lamb-Type Waves in Solid\\/Liquid\\/Solid Structure  

Microsoft Academic Search

We considered the negative group velocity of plate-mode waves. Lamb waves are a typical example of existence of negative group velocity. However, if we try to apply the negative group velocity of Lamb waves to some applications such as acoustical flat lenses, there is a problem about the existence of negative group velocity of Lamb waves. Its existence depends only

Kojiro Nishimiya; Koichi Mizutani; Naoto Wakatsuki; Ken Yamamoto

2008-01-01

271

Morne aux Diables. a potentially active volcano in northern Dominica, Lesser Antilles  

NASA Astrophysics Data System (ADS)

The island of Dominica, which is located near the center of the Lesser Antilles island arc, comprises at least 8 potentially active volcanoes. One of these is Morne aux Diables, an isolated composite cone situated at the extreme northern end of the island. Age dating suggests that the main cone building activity occurred between 1.5 and 1.0 million years ago. Exposed on the volcano's flanks however are a number of unconsolidated valley-fill block and ash flow deposits suggesting more recent activity. One of these deposits, on the north-east flank of the volcano, has been recently dated at > 46,000 years B.P. Other evidence of potential activity from this center includes the presence of warm (27°C), acidic (pH 1.6), sulfate-rich springs on the summit of the volcano, hot springs on the coast, and the occurrence in 2002 and 2003 of shallow earthquake swarms partially located beneath the volcano. Morne aux Diables is dominantly composed of deposits of block and ash flows and associated domes from Pelean-style activity, however, semi-vesicular andesite block and ash flows and surges (Asama-style activity) and pumiceous lapilli falls (Plinian-style activity) are locally abundant. The Pelean domes are located both in the summit region and along the southern flanks of the volcano. Petrologically, the volcano is composed of a monotonous series of porphyritic andesites and dacites containing phenocrysts of plagioclase+augite-hypersthene with very sparse crystals of hornblende and quartz. Petrological models suggest the Morne aux Diables andesites and dacites can be produced by fractional crystallization of basaltic magma (such as those erupted from centers such as Morne Anglais and Morne Plat Pays in the south). Minor variations within this suite of andesites and dacites can be related to upper crustal fractionation of phenocryst phases.

Rheubottom, A. N.; Smith, A. L.; Roobol, M. J.

2005-12-01

272

Twinkling Fractal Theory of the Glass Transition: Applications and Insights  

NASA Astrophysics Data System (ADS)

The new perspective on the Glass Transition of amorphous materials offered by theTwinkling Fractal Theory (TFT). [R. P. Wool, J. Polym. Sci, Part B: Polym Phys. 46, 2765 (2008)] is examined in several applications. The TFT describes Tg in terms of the autocorrelation relaxation function for the spatio-temporal solid-liquid fluctuations which are related to the vibrational frequencies (``twinkles'') described by the Orbach vibrational density of states for a fractal. The twinkling frequencies for solid-liquid interchange are due to Boltzmann energy populations of interatomic oscillators interacting through anharmonic potentials U(x) with energy Do of order 1-5 kcal/mol. Tg occurs when the activation energy for the solid-liquid transition goes to zero at the inflection point of U(x) and is given by Tg = 2Do/9k. The applications include: (a) group contributions to Do, (b) the rate and temperature dependence of yielding and fracture, (c) shear thickening fluids, (d) rate dependence of dynamical mechanical properties, particularly the tan delta damping peak used to measure Tg, (e) derivation of the empirical WLF time-temperature superposition empirical relation, (f) thermal expansion and (g) physical aging.

Wool, Richard

2009-03-01

273

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

PubMed Central

Résumé Objectif Mettre à jour les lignes directrices canadiennes de 2006 sur les soins primaires aux adultes ayant une déficience développementale (DD) et présenter des recommandations pratiques fondées sur les connaissances actuelles pour traiter des problèmes de santé particuliers chez des adultes ayant une DD. Qualité des preuves Des professionnels de la santé expérimentés participant à un colloque et un groupe de travail subséquent ont discuté et convenu des révisions aux lignes directrices de 2006 en se fondant sur une recherche documentaire exhaustive, la rétroaction obtenue des utilisateurs du guide de pratique et les expériences cliniques personnelles. La plupart des preuves disponibles dans ce domaine viennent de l’opinion d’experts ou de déclarations consensuelles publiées (niveau III). Message principal Les adultes ayant une DD ont des problèmes de santé complexes, dont plusieurs diffèrent de ceux de la population en général. De bons soins primaires permettent d’identifier les problèmes de santé particuliers dont souffrent les adultes ayant une DD pour améliorer leur qualité de vie et leur accès aux soins de santé et prévenir la morbidité et le décès prématuré. Ces lignes directrices résument les problèmes de santé générale, physique, comportementale et mentale des adultes ayant une DD que devraient connaître les professionnels des soins primaires et présentent des recommandations pour le dépistage et la prise en charge en se basant sur les connaissances actuelles que les cliniciens peuvent mettre en pratique. En raison de l’interaction des facteurs biologiques, psychoaffectifs et sociaux qui contribuent à la santé et au bien-être des adultes ayant une DD, ces lignes directrices insistent sur la participation des aidants, l’adaptation des interventions, au besoin, et la consultation auprès de divers professionnels de la santé quand ils sont accessibles. Elles mettent aussi en évidence la nature éthique des soins. Les lignes directrices sont formulées dans le contexte d’un cadre éthique qui tient compte des questions comme le consentement éclairé et l’évaluation des bienfaits pour la santé par rapport aux risques de préjudice. Conclusion La mise en œuvre des lignes directrices proposées ici améliorerait la santé des adultes ayant une DD et minimiserait les disparités sur les plans de la santé et des soins de santé entre les adultes ayant une DD et la population en général.

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

2011-01-01

274

Aperçu phytosociologique sur les pâturages naturels aux environs de castelo de vide  

Microsoft Academic Search

Résumé  Etudiant les jachères pâturées de la zone de culture du seigle, aux environs de Castelo de Vide, l'auteur définit une association\\u000a nouvelle — le Lupineto-Astrocarpetum purpurascentis — appartenant à l'Helianthemion guttati Br.-Bl. (1931) 1940 em.\\u000a \\u000a Cette association occupe les sols siliceux, nettement acides, frais pendant l'hiver et une partie du printemps. Elle présente\\u000a un caractère floristique méditerranéen très net, tout

J. Malato-Beliz

1954-01-01

275

Aspects électrochimiques de l'essai accéléré de perméabilité aux ions chlorures  

Microsoft Academic Search

Résumé  Cet article décrit les aspects électrochimiques de l'essai accéléré de perméabilité aux chlorures; il souligne le rôle de\\u000a la tension appliquée à la cellule et celui de la résistance électrique du béton. Ces deux paramètres déterminent les potentiels\\u000a d'électrodes et conditionnent les réactions électrochimiques qui sont susceptibles de s'y développer. Dans les conditions\\u000a opératoires classiques de l'essai, l'électrolyse de l'eau

W. Prince; J.-P. Ollivier; O. Truc

1999-01-01

276

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

Microsoft Academic Search

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

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

1985-01-01

277

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

Microsoft Academic Search

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

Silvio de Santis

1999-01-01

278

Optimisation de dispositifs en guide d'onde avec coupleur a réseau : application aux commutateurs optiques  

Microsoft Academic Search

Numerous devices used in the field of photonics and optronics are made of semiconductor multilayered structures including a nonlinear waveguide and a grating coupler. Optimization of such devices depends on the optical thicknesses of the various layers and on the grating characteristics. For a given sample, the layer parameters are usually known as a first approximation, but a good accuracy

F. Bertrand; N. Paraire; P. Dansas; N. Moresmau

1994-01-01

279

Le silicium nanoporeux: microstructuration diélectrique et application aux structures photoniques avancées  

NASA Astrophysics Data System (ADS)

The aim of this work is to elaborate and study photonic bandgap microstructures using nanoporous silicon. Planar microstructures like microcavities are first considered, and their influence on both angular and spectral distributions of photoluminescence are investigated. The primary conclusion derived from these studies is that it is essential to control the propagation of light in the plane, too. Thus, the lateral propagation of light, enhanced by a vertical structuring of the optical index (step-index waveguide as well as Bragg reflection waveguide) is studied. Furthermore, a numerical model based on the standard transfer-matrix method is suggested to calculate guiding losses. Finally, a holographic process is utilized to obtain a lateral structuring of the optical index, thereby allowing the investigation of its effects on the guided light. The transmittance, measured on a multimode waveguide using white light, shows several stopbands, which are attributed to diagonal and off-diagonal couplings. The comparison of these measurements to the coupled-mode theory allows a map of the optical index to be plotted. A strong birefringence in regions that were illuminated during the holographic process was illustrated. This suggests a stronger decrease of the extraordinary index (? n = -0.4) than the ordinary index (? n = -0.22). With a period of 450 nm, these values of index contrast are promising, even if the effective depth on which the index is modulated is only 0.5 ?m. Ce travail est consacré à la réalisation et à l'étude de microstructures photoniques à base de silicium nanoporeux. Nous commençons notre étude par des structures planaires de type microcavité, dont nous caractérisons l'influence sur la photoluminescence du matériau, en termes de redistribution spectrale et angulaire. Il apparaît très vite la nécessité de contrôler la propagation de la lumière dans le plan de la structure. Aussi, nous cherchons d'abord à favoriser la propagation latérale au moyen d'une structuration verticale de l'indice, et nous étudions le guidage au moyen de deux types de structures, exploitant soit à un guidage conventionnel par réflexion totale interne, soit à un guidage par réflexion de Bragg. À cette occasion nous proposons une méthode numérique, basée sur le formalisme des matrices de transfert, permettant de calculer l'atténuation de la puissance transportée dans le plan. Par la suite, nous mettons à profit le procédé holographique de structuration d'indice démontré par des travaux antérieurs et étudions son influence sur la lumière guidée. La transmission, mesurée en lumière blanche sur un guide multimode révèle de multiples bandes interdites que nous interprétons en termes de couplages diagonaux et non diagonaux. La confrontation des mesures avec une modélisation par la méthode des modes couplés nous permet d'établir une carte d'indice de notre structure. Il apparaît une biréfringence marquée dans les régions insolées par le procédé holographique, caractérisées par une diminution deux fois plus importante de l'indice extraordinaire (? n =-0{,}4) que de l'indice ordinaire (? n =-0{,}22). Avec une période de 450 nm, ces valeurs de contraste sont encourageantes, bien que la modulation d'indice ne soit présente que sur une profondeur effective de l'ordre de 0,5 ?m.

Ferrand, P.

2002-03-01

280

Le coussinet adipeux de Charpy. Anatomie descriptive et fonctionnelle. Applications aux nouveaux liftings  

Microsoft Academic Search

The eyebrow fat pad, or retro-orbicularis oculus fat (ROOF) is a syssarcosis, described as an anatomic and functional unity by M. Charpy in 1909. Our anatomic study on 12 (24 half-head) fresh cadaver specimens confirm anatomic variations, mainly according to age and sex. Synthesis of recent literature shows the renewed interest for this fat pad and its involvement in the eye's

F. Aghai; P. Caix

2004-01-01

281

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

282

Application of high hydrostatic pressure processing of food to extracting lycopene from tomato paste waste  

Microsoft Academic Search

The application of high hydrostatic pressure (HHP) processing of food to extracting lycopene from tomato paste waste was studied. Various experimental conditions of HHP processing process, such as solvents (chloroform, 95% ethanol and distilled water), ethanol concentration (45–95%, v\\/v), pressure (100–600 MPa), duration (1–10 min) and solid\\/liquid ratio (1:1 to 1:8 g\\/ml), were investigated to optimize the extraction process. The experimental results of

X. Jun

2006-01-01

283

The Tomato Aux/IAA Transcription Factor IAA9 Is Involved in Fruit Development and Leaf MorphogenesisW?  

PubMed Central

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 Aux/IAA genes, results in a pleiotropic phenotype, consistent with its ubiquitous expression pattern. IAA9-inhibited lines have simple leaves instead of wild-type compound leaves, and fruit development is triggered before fertilization, giving rise to parthenocarpy. This indicates that IAA9 is a key mediator of leaf morphogenesis and fruit set. In addition, antisense plants displayed auxin-related growth alterations, including enhanced hypocotyl/stem elongation, increased leaf vascularization, and reduced apical dominance. Auxin dose–response assays revealed that IAA9 downregulated lines were hypersensitive to auxin, although the only early auxin-responsive gene that was found to be upregulated in the antisense lines was IAA3. The activity of the IAA3 promoter was stimulated in the IAA9 antisense genetic background, indicating that IAA9 acts in planta as a transcriptional repressor of auxin signaling. While no mutation in any member of subfamily IV has been reported to date, the phenotypes associated with the downregulation of IAA9 reveal distinct and novel roles for members of the Aux/IAA gene family.

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

2005-01-01

284

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.

Monavari, Sanam; Galbe, Mats; Zacchi, Guido

2009-01-01

285

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

286

Enzyme adsorption at solid-liquid interfaces  

Microsoft Academic Search

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

S. Duinhoven

1992-01-01

287

Applications des Procedes Sol-Gel aux Composites Ceramiques (Application of Sol-Gel Procedures to Ceramic Composites).  

National Technical Information Service (NTIS)

Colloidal solutions were synthesized and characterized in order to contribute to the development of ceramics based on aluminum phosphate, lithium silico-aluminate, and magnesium silico-aluminate. The surface deposits on carbon-carbon and carbon-SiC compos...

L. Coury

1987-01-01

288

Modelisation de la diffusion sur les surfaces metalliques: De l'adatome aux processus de croissance  

NASA Astrophysics Data System (ADS)

Cette these est consacree a l'etude des processus de diffusion en surface dans le but ultime de comprendre, et de modeliser, la croissance d'une couche mince. L'importance de bien mai triser la croissance est primordiale compte tenu de son role dans la miniaturisation des circuits electroniques. Nous etudions ici les surface des metaux nobles et de ceux de la fin de la serie de transition. Dans un premier temps, nous nous interessons a la diffusion d'un simple adatome sur une surface metallique. Nous avons, entre autres, mis en evidence l'apparition d'une correlation entre evenements successifs lorsque la temperature est comparable a la barriere de diffusion, i.e., la diffusion ne peut pas etre associee a une marche aleatoire. Nous proposons un modele phenomenologique simple qui reproduit bien les resultats des simulations. Ces calculs nous ont aussi permis de montrer que la diffusion obeit a la loi de Meyer-Neldel. Cette loi stipule que, pour un processus active, le prefacteur augmente exponentiellement avec la barriere. En plus, ce travail permet de clarifier l'origine physique de cette loi. En comparant les resultats dynamiques aux resultats statiques, on se rend compte que la barriere extraite des calculs dynamiques est essentiellement la meme que celle obtenue par une approche statique, beaucoup plus simple. On peut donc obtenir cette barriere a l'aide de methodes plus precises, i.e., ab initio, comme la theorie de la fonctionnelle de la densite, qui sont aussi malheureusement beaucoup plus lourdes. C'est ce que nous avons fait pour plusieurs systemes metalliques. Nos resultats avec cette derniere approche se comparent tres bien aux resultats experimentaux. Nous nous sommes attardes plus longuement a la surface (111) du platine. Cette surface regorge de particularites interessantes, comme la forme d'equilibre non-hexagonale des i lots et deux sites d'adsorption differents pour l'adatome. De plus, des calculs ab initio precedents n'ont pas reussi a confirmer la forme d'equilibre et surestiment grandement la barriere. Nos calculs, plus complets et dans un formalisme mieux adapte a ce genre de probleme, predisent correctement la forme d'equilibre, qui est en fait due a un relachement different du stress de surface aux deux types de marches qui forment les cotes des i lots. Notre valeur pour la barriere est aussi fortement diminuee lorsqu'on relaxe les forces sur les atomes de la surface, amenant le resultat theorique beaucoup plus pres de la valeur experimentale. Nos calculs pour le cuivre demontre en effet que la diffusion de petits i lots pendant la croissance ne peut pas etre negligee dans ce cas, mettant en doute la valeur des interpretations des mesures experimentales. (Abstract shortened by UMI.)

Boisvert, Ghyslain

289

EXTERNAL ASSISTANCE FOR FOOD PRODUCTION TO LDCs \\/ L'AIDE EXTERIEURE A LA PRODUCTION ALIMENTAIRE AUX PVD  

Microsoft Academic Search

Un examen rapide de l'aide à la production alimentaire durant la période 1975-1980 paraît intéressant en raison de la perspective d'une réduction de l'aide extérieure aux pays en voie de développement (PVD). L'aide à la production alimentaire est passée de 3,3 milliards de dollars en 1975 à 8,0-8,5 milliards en 1980, soit une augmentation en termes réels de près de

Martha Aida Eid

1981-01-01

290

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

PubMed

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

Golan, Guy; Betzer, Rotem; Wolf, Shmuel

2013-08-23

291

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

PubMed Central

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

Golan, Guy; Betzer, Rotem; Wolf, Shmuel

2013-01-01

292

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

PubMed

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

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

2010-11-17

293

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

SciTech Connect

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

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

1991-08-01

294

Mesures en temps réel par diffusion de neutrons aux petits angles (DNPA) avec un appareil à ``flux stoppé'' (stopped-flow)  

NASA Astrophysics Data System (ADS)

La nouvelle génération de diffractomètres à haut flux pour la diffusion de neutrons aux petits angles, comme D22 à l'ILL, ouvre de nouvelles perspectives avec les expériences “temps réel” et les “cinétiques rapides”. “Temps réel” signifie un film de l'échantillon après une perturbation, par exemple un saut en température, une variation de pH, une dilution, un mélange ou encore l'application d'un champ magnétique. Par “rapide” on entend des temps d'acquisition courts, de l'ordre de quelques centaines de millisecondes pour suivre les toutes premières étapes de formation et d'organisation de l'échantillon. La connaissance d'éventuelles phases intermédiaires peut être cruciale pour comprendre les propriétés de l'échantillon dans son état d'équilibre. Pour ces expériences, un appareil à flux stoppé (Bio-Logic^TM) a été spécialement adapté pour la DNPA. Il permet de mélanger rapidement deux à trois solutions en contrôlant précisement les volumes et les temps de mélanges puis de démarrer l'observation en connaissant le délai après le début de la réaction. Cette nouvelle technique a été utilisée pour suivre la croissance de vésicules formées après dilution de micelles d'AOT par une solution saline. Le moteur de la croissance est l'écrantage des répulsions électrostatiques entre les têtes polaires tensioactives, ce qui favorise la formation d'une bicouche localement plane.

Grillo, I.

2005-11-01

295

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

NASA Astrophysics Data System (ADS)

The Cran aux iguanodons of Bernissart is a sinkhole (or chimney caving) with a valuable paleontological deposit due to the exceptional quantity and diversity of fossils found during the excavation conducted from 1878 to 1881. In fact, bones have been discovered in a clayey geological formation when digging à mine gallery at the -322 m level. A subsequent extraction gave an overall production of 29 iguanodons skeletons. Referring to the available data at the Natural Sciences Museum of Brussels where the found skeletons are exhibited, one does not know the degree of depletion of the deposit after the extraction. A feasibility study (Tshibangu and Dagrain 1998) showed then the need to drill 4 exploration wells of 400 m depth with different objectives: to evaluate the chance of finding more fossils, understanding how and when the geological formations moved down, and testing a seismic geophysical technique for ground imaging. The typical geological formations concerned are: chalk, limestone, conglomerate, clays, and layers of silex nodules. In October 2002 the workings started with a completely cored well (the Number 3) using the PQ wireline technique. During operations, different parameters have been recorded: rate of penetration, core recovery and a brief core description. Some problems have been encountered when crossing silex stones contained in a clayey matrix; and this paper gives some interpretations in terms of the relationship between the lithology and the drilling performances.

Tshibangu, Jean-Pierre; Dagrain, Fabrice; Legrain, Hughes; Deschamps, Benoît

296

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

PubMed Central

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

Song, Yaling; Xu, Zeng-Fu

2013-01-01

297

Applications  

NASA Astrophysics Data System (ADS)

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

Stern, Arthur M.

1986-07-01

298

Satellite remote sensing in monitoring change of seabirds: use of Spot Image in king penguin population increase at Ile aux Cochons, Crozet Archipelago  

Microsoft Academic Search

The king penguin colony at Ile aux Cochons, Crozet Archipelago (southern Indian Ocean) is the largest in the world. The change in its surface area was investigated by means of satellite remote sensing using spot scene. The satellite picture enabled us to locate the colony and to determine that the surface area occupied by the colony has increased by 56%

Christophe Guinet; Pierre Jouventin; Jean Malacamp

1995-01-01

299

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

Microsoft Academic Search

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

V Mangar

300

Observation par topographie aux rayons X des configurations de dislocations developpees a l'extremite d'une fissure dans le silicium  

Microsoft Academic Search

Des monocristaux de silicium, préfissurés à température ambiante, sont chargés en mode 1, à 800°C, la charge appliquée correspondant à un facteur d'intensité de constrainte KI < KIC. Les configurations de dislocations développées à l'extrémité de la fissure sont étudiées par topographie aux rayons X. Les dislocations sont contenues dans les plans {111} qui coupent le front de fissure. Dans

Par G. Michot; K. Badawi; A. R. Ab Del Halim; A. George

1980-01-01

301

An improved technique for modeling initial reservoir hydrocarbon saturation distributions: applications in Illinois (USA) Aux Vases oil reservoirs  

Microsoft Academic Search

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

Emmanuel Udegbunam; Jude O. Amaefule

1998-01-01

302

Modèle multi-échelle du transport de fluide dans un milieu poreux chargé avec échanges cationiques : application aux tissus osseux  

NASA Astrophysics Data System (ADS)

To better understand the bone diseases, many models of porous cortical bone have been developed to simulate its in vivo behaviour. Thus we proposed multiscale models including multiphysical phenomena governing the hydraulic response of bone. However, all these models neglected the possible ionic exchanges at the cellular level. Since such chemical reactions directly change the physico-chemical properties of the tissue, the interstitial flow is also modified. The aim of this study is so to include these ionic exchanges in the bone fluid transport description by deriving their consequences at the macroscale. To cite this article: J. Kaiser et al., C. R. Mecanique 337 (2009).

Kaiser, Joanna; Lemaire, Thibault; Naili, Salah; Sansalone, Vittorio

2009-11-01

303

Residus de 2-formes differentielles sur les surfaces algebriques et applications aux codes correcteurs d'erreurs  

NASA Astrophysics Data System (ADS)

The theory of algebraic-geometric codes has been developed in the beginning of the 80's after a paper of V.D. Goppa. Given a smooth projective algebraic curve X over a finite field, there are two different constructions of error-correcting codes. The first one, called "functional", uses some rational functions on X and the second one, called "differential", involves some rational 1-forms on this curve. Hundreds of papers are devoted to the study of such codes. In addition, a generalization of the functional construction for algebraic varieties of arbitrary dimension is given by Y. Manin in an article of 1984. A few papers about such codes has been published, but nothing has been done concerning a generalization of the differential construction to the higher-dimensional case. In this thesis, we propose a differential construction of codes on algebraic surfaces. Afterwards, we study the properties of these codes and particularly their relations with functional codes. A pretty surprising fact is that a main difference with the case of curves appears. Indeed, if in the case of curves, a differential code is always the orthogonal of a functional one, this assertion generally fails for surfaces. Last observation motivates the study of codes which are the orthogonal of some functional code on a surface. Therefore, we prove that, under some condition on the surface, these codes can be realized as sums of differential codes. Moreover, we show that some answers to some open problems "a la Bertini" could give very interesting informations on the parameters of these codes.

Couvreur, A.

2009-05-01

304

Diversification and Expression of the PIN, AUX/LAX, and ABCB Families of Putative Auxin Transporters in Populus  

PubMed Central

Intercellular transport of the plant hormone auxin is mediated by three families of membrane-bound protein carriers, with the PIN and ABCB families coding primarily for efflux proteins and the AUX/LAX family coding for influx proteins. In the last decade our understanding of gene and protein function for these transporters in Arabidopsis has expanded rapidly but very little is known about their role in woody plant development. Here we present a comprehensive account of all three families in the model woody species Populus, including chromosome distribution, protein structure, quantitative gene expression, and evolutionary relationships. The PIN and AUX/LAX gene families in Populus comprise 16 and 8 members respectively and show evidence for the retention of paralogs following a relatively recent whole genome duplication. There is also differential expression across tissues within many gene pairs. The ABCB family is previously undescribed in Populus and includes 20 members, showing a much deeper evolutionary history, including both tandem and whole genome duplication as well as probable gene loss. A striking number of these transporters are expressed in developing Populus stems and we suggest that evolutionary and structural relationships with known auxin transporters in Arabidopsis can point toward candidate genes for further study in Populus. This is especially important for the ABCBs, which is a large family and includes members in Arabidopsis that are able to transport other substrates in addition to auxin. Protein modeling, sequence alignment and expression data all point to ABCB1.1 as a likely auxin transport protein in Populus. Given that basipetal auxin flow through the cambial zone shapes the development of woody stems, it is important that we identify the full complement of genes involved in this process. This work should lay the foundation for studies targeting specific proteins for functional characterization and in situ localization.

Carraro, Nicola; Tisdale-Orr, Tracy Eizabeth; Clouse, Ronald Matthew; Knoller, Anne Sophie; Spicer, Rachel

2012-01-01

305

Immunité des stimulateurs cardiaques aux interférences électromagnétiques de basses fréquences: cas des perturbations conduites  

Microsoft Academic Search

The goal of this work is to characterize the immunity of cardiac pacemakers to low frequency electromagnetic disruptions. The frequencies studied are 50 Hz and 60 Hz, which simulate electrical energy distribution, and 10 kHz and 25 kHz, which are in the frequency band corresponding to domestic and industrial applications of induction. The assessment methodology which is applied is in

C Goeury; A Hedjiedj; P Schmitt; M Nadi

2001-01-01

306

Les immigrants tres scolarises obtiennent-ils des resultats differents sur le marche du travail au Canada et aux Etats-Unis?  

Microsoft Academic Search

On compare dans le present document les changements dans les salaires des nouveaux travailleurs immigrants titulaires d'un diplome universitaire au Canada et aux Etats-Unis au cours de la periode allant de 1980 a 2005 a ceux de leurs homologues nes au pays et a ceux des diplomes d'etudes secondaires (avantage salarial du diplome universitaire). Les salaires des nouveaux immigrants de

Aneta Hou Feng Picot Garnett Bonikowska

2011-01-01

307

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

2012-07-03

308

Isoelectronically substituted heavy-fermion compounds CeCu6-xAux , studied by local probe and electronic band structure calculation  

Microsoft Academic Search

For CeCu6-xAux (x=0,0.1,1) , we measured the temperature dependence of Cu63,65 nuclear magnetic resonance spectra of oriented single-crystal powder at 7T in the 5-100K range. Ce3+ crystal field and molecular field parameters are derived from single-crystal magnetic susceptibility data. Calculated electric field gradients are used to correctly assign nuclear quadrupole resonance frequencies to lattice sites (n) . Bare Knight shifts

M. Winkelmann; G. Fischer; B. Pilawa; M. S. S. Brooks; E. Dormann

2006-01-01

309

Observation of linear to planar structural transition in sulfur-doped gold clusters: Au(x)S- (x = 2-5).  

PubMed

We report a joint experimental and theoretical study on the structures of a series of gold clusters doped with a sulfur atom, Au(x)S(-) (x = 2-5). Well-resolved photoelectron spectra are obtained and compared with theoretical results calculated using several density functional methods to elucidate the structures and bonding of Au(x)S(-) (x = 2-5). Au2S(-) is found to have an asymmetric linear global minimum structure with C(?v) symmetry, while the most stable structure of neutral Au2S is bent with C(2v) symmetry, reminiscent of H2S. Au3S(-) is found to have an asymmetric bent structure with an Au-S-Au-Au connectivity. Two isomers are observed experimentally to co-exist for Au4S(-): a symmetric bent 1D structure (C(2v)) and a 2D planar low-lying isomer (C(s)). The global minimum of Au5S(-) is found to be a highly stable planar triangular structure (C(2v)). Thus, a 1D-to-2D structural transition is observed in the Au(x)S(-) clusters as a function of x at x = 4. Molecular orbital analyses are carried out to obtain insight into the nature of the chemical bonding in the S-doped gold clusters. Strong covalent bonding between S and Au is found to be responsible for the 1D structures of Au(x)S(-) (x = 2-4), whereas delocalized Au-Au interactions favor the 2D planar structure for the larger Au5S(-) cluster. PMID:23656130

Wen, Hui; Liu, Yi-Rong; Huang, Teng; Xu, Kang-Ming; Zhang, Wei-Jun; Huang, Wei; Wang, Lai-Sheng

2013-05-01

310

Environmental and auxin regulation of wood formation involves members of the Aux/IAA gene family in hybrid aspen.  

PubMed

Indole acetic acid (IAA/auxin) profoundly affects wood formation but the molecular mechanism of auxin action in this process remains poorly understood. We have cloned cDNAs for eight members of the Aux/IAA gene family from hybrid aspen (Populus tremula L. x Populus tremuloides Michx.) that encode potential mediators of the auxin signal transduction pathway. These genes designated as PttIAA1-PttIAA8 are auxin inducible but differ in their requirement of de novo protein synthesis for auxin induction. The auxin induction of the PttIAA genes is also developmentally controlled as evidenced by the loss of their auxin inducibility during leaf maturation. The PttIAA genes are differentially expressed in the cell types of a developmental gradient comprising the wood-forming tissues. Interestingly, the expression of the PttIAA genes is downregulated during transition of the active cambium into dormancy, a process in which meristematic cells of the cambium lose their sensitivity to auxin. Auxin-regulated developmental reprogramming of wood formation during the induction of tension wood is accompanied by changes in the expression of PttIAA genes. The distinct tissue-specific expression patterns of the auxin inducible PttIAA genes in the cambial region together with the change in expression during dormancy transition and tension wood formation suggest a role for these genes in mediating cambial responses to auxin and xylem development. PMID:12220260

Moyle, Richard; Schrader, Jarmo; Stenberg, Anneli; Olsson, Olof; Saxena, Sangeeta; Sandberg, Göran; Bhalerao, Rishikesh P

2002-09-01

311

Comparative Performance of the RapID Yeast Plus System and the API 20C AUX Clinical Yeast System  

PubMed Central

The performance of the RapID Yeast Plus System (Innovative Diagnostic Systems, Norcross, Ga.), a 4-h micropanel using single-substrate enzymatic test reactions, was compared with that of the API 20C AUX Clinical Yeast System (bioMerieux Vitek, Hazelwood, Mo.), a 48- to 72-h carbohydrate assimilation panel. Two hundred twenty-five yeasts, yeast-like fungi, and algae, comprising 28 species and including 30 isolates of Cryptococcus neoformans, an important pathogen not tested in appreciable numbers in other comparisons, were tested by both methods. On initial testing, 196 (87.1%) and 215 (95.6%) isolates were correctly identified by the RapID and API systems, respectively. Upon repeat testing, the number of correctly identified isolates increased to 220 (97.8%) for the RapID system and 223 (99.1%) for the API system. Reducing the turbidity of the test inoculum to that of a no. 3 McFarland turbidity standard, which is below that recommended by the manufacturer, resulted in the correct identification of most of the isolates initially misidentified by the RapID system, including 10 of 30 C. neoformans isolates. Concordance between the RapID and API results after repeat testing was 97.3%.

Smith, Michael B.; Dunklee, Daisy; Vu, Hangna; Woods, Gail L.

1999-01-01

312

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

313

Red blood cell adhesion on a solid/liquid interface  

PubMed Central

Red blood cells (RBCs), previously fixed with glutaraldehyde, adhere to glass slides coated with fibrinogen. The RBC deposition process on the horizontal glass surface is investigated by analyzing the relative surface covered by the RBCs, as well as the variance of this surface coverage, as a function of the concentration of particles. This study is performed by optical microscopy and image analysis. A model, derived from the classical random sequential adsorption model, has been developed to account for the experimental results. This model highlights the strong influence of the hydrodynamic interactions during the deposition process.

Lavalle, Ph.; Stoltz, J.-F.; Senger, B.; Voegel, J.-C.; Schaaf, P.

1996-01-01

314

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

2012-07-18

315

-hexabenzocoronene derivative in solution and at a solid liquid interface  

NASA Astrophysics Data System (ADS)

An azobenzene moiety rigidly linked to a hexa-peri-hexabenzocoronene (HBC) derivative has been switched optically between its trans- and cis-conformations in solution. Crystalline monolayers of the flat lying trans-conformer have been obtained at the interface between the basal plane of graphite and an organic solution. However, from the illuminated solution no cis-conformer was observed adsorbed to the interface, indicating that the resulting cis- conformer is not thermodynamically stable at this interface, possibly due to the competition with the coexisting trans-conformers. Therefore, two-dimensional honeycombs self-assembled from derivatives of three-fold symmetric polycyclic aromatic hydrocarbons were investigated, which may be employed as templates, providing the necessary space for conformational switching of an azobenzene moiety, and tune the current voltage characteristics through the aromatic cores. As a first step towards this goal, the capability of the template to host single molecular guests was studied by filling the voids with individual coronene molecules.

Ai, Min; Groeper, Susie; Zhuang, Wei; Dou, Xi; Feng, Xinliang; Müllen, Klaus; Rabe, Jürgen P.

2008-09-01

316

Decaffeination of coffee bean waste by solid-liquid extraction  

Microsoft Academic Search

Many residues of plants are hydrolyzed to prepare polysaccharides and monosaccharide by bio-methods. Coffee bean waste is\\u000a emerging as a new feed for producing these carbohydrates, but the appearance of caffeine in coffee bean waste prevents the\\u000a enzymatic or bacterial hydrolysis. In this case, several solvents were used to remove the caffeine from the coffee waste as\\u000a well as optimizing

Wentao Bi; Jun Zhou; Kyung Ho Row

2011-01-01

317

Supersonic Air Flow due to Solid-Liquid Impact  

NASA Astrophysics Data System (ADS)

A solid object impacting on liquid creates a liquid jet due to the collapse of the impact cavity. Using visualization experiments with smoke particles and multiscale simulations, we show that in addition, a high-speed air jet is pushed out of the cavity. Despite an impact velocity of only 1m/s, this air jet attains supersonic speeds already when the cavity is slightly larger than 1 mm in diameter. The structure of the air flow closely resembles that of compressible flow through a nozzle—with the key difference that here the “nozzle” is a liquid cavity shrinking rapidly in time.

Gekle, Stephan; Peters, Ivo R.; Gordillo, José Manuel; van der Meer, Devaraj; Lohse, Detlef

2010-01-01

318

Mechanics of soft-solid-liquid-crystal interfaces  

Microsoft Academic Search

The interfacial mechanics of soft elastic solids and nematic liquid crystals is presented. The theory can be applied to interfaces involving gels, elastomers, biomaterials, and thermotropic nematic liquid crystals. A model of anisotropic elastic interfaces is formulated and used to derive two fundamental capillary quantities: (i) interfacial torques on the nematic orientation, and (ii) capillary pressure. The couplings between soft-solid

Alejandro D. Rey

2005-01-01

319

Mechanics of soft-solid-liquid-crystal interfaces  

NASA Astrophysics Data System (ADS)

The interfacial mechanics of soft elastic solids and nematic liquid crystals is presented. The theory can be applied to interfaces involving gels, elastomers, biomaterials, and thermotropic nematic liquid crystals. A model of anisotropic elastic interfaces is formulated and used to derive two fundamental capillary quantities: (i) interfacial torques on the nematic orientation, and (ii) capillary pressure. The couplings between soft-solid deformation and liquid-crystal anisotropic interfacial tension is shown to lead to strain-induced anchoring transitions, and strain-induced morphological instabilities.

Rey, Alejandro D.

2005-07-01

320

Supersonic Air Flow due to Solid-Liquid Impact  

Microsoft Academic Search

A solid object impacting on liquid creates a liquid jet due to the collapse of the impact cavity. Using visualization experiments with smoke particles and multiscale simulations, we show that in addition, a high-speed air jet is pushed out of the cavity. Despite an impact velocity of only 1m\\/s, this air jet attains supersonic speeds already when the cavity is

Stephan Gekle; Ivo R. Peters; José Manuel Gordillo; Devaraj van der Meer; Detlef Lohse

2010-01-01

321

Supersonic Air Flow due to Solid-Liquid Impact  

Microsoft Academic Search

A solid object impacting on liquid creates a liquid jet due to the collapse of the impact cavity. Using visualization experiments with smoke particles and multiscale simulations, we show that in addition, a high-speed air jet is pushed out of the cavity. Despite an impact velocity of only 1??m\\/s, this air jet attains supersonic speeds already when the cavity is

Stephan Gekle; Ivo R. Peters; Jose Manuel Gordillo; Meer van der Devaraj; Detlef Lohse

2010-01-01

322

Rayleigh-Taylor stability boundary at solid-liquid interfaces.  

PubMed

A previous model for the Rayleigh-Taylor instability [A. R. Piriz, J. J. López Cela, and N. A. Tahir, Phys. Rev. E 80, 046305 (2009)] has been extended in order to study an interface between an elastic-plastic solid and a Newtonian liquid and determine the stability region given by the initial perturbation amplitude ?(0) and wavelength ?. The stability region is found to be enhanced by the effect of the liquid viscosity, but it reaches an asymptote for a sufficiently high viscosity. In addition, it is also found that the boundary for the transition from the elastic to the plastic regime get closer to the stability boundary up to both boundaries coincide for a high enough liquid viscosity, thus making the onset of plastic flow a sufficient condition for instability. PMID:24032942

Piriz, A R; Sun, Y B; Tahir, N A

2013-08-29

323

Direct simulation of flows of solid-liquid mixtures  

Microsoft Academic Search

A finite element technique based on moving unstructured grids is developed to simulate the motion of a large number of solid particles in a flowing liquid. A generalized Galerkin finite element formulation which incorporates both the fluid and particle equations of motion into a single variational equation is developed for Newtonian fluids. The hydrodynamic forces and moments acting on the

H. H. Hu

1996-01-01

324

Solid–liquid phase diagrams of binary mixtures  

Microsoft Academic Search

This study reports the investigation of three binary mixtures represented by acetylsalicylic acid (ASA) with its most important\\u000a degradation product, salicylic acid (SA), and two of the most commonly used excipients (polyethylene glycol 4000 (PEG-4000)\\u000a and d-mannitol (MA)). The liquidus and solidus equilibrium temperatures determined by DSC for pure components and solid binary\\u000a mixtures at a fixed composition (mass fraction

Luigi Campanella; Valentina Micieli; Mauro Tomassetti; Stefano Vecchio

2010-01-01

325

Solid–liquid separation of livestock slurry: efficiency and cost  

Microsoft Academic Search

Environmental problems may arise on specialized livestock farms, which produce a surplus of nutrients in relation to crop requirements. Separation of this slurry into a liquid fraction and a dry-matter and nutrient-rich fraction, followed by transporting the nutrient-rich fraction to farms with fewer animals, may alleviate the problem. This study showed that the most informative index of separation is the

H. B Møller; I Lund; S. G Sommer

2000-01-01

326

Alternatives aux prothèses mammaires  

Microsoft Academic Search

The use of implants is a basic technique in breast reconstruction after mastectomy, for the correction of breast abnormalities or even more in aesthetic breast augmentation. However, especially in difficult cases, implants can have inconveniences and insufficiencies (poor natural aspect, necessity of replacement, capsular contracture). To mitigate these, numerous alternatives were developed. These autologous techniques use mainly the pedicled or

E. Delay; T. Delaporte; R. Sinna

2005-01-01

327

Communication presentee aux \\  

Microsoft Academic Search

This paper will present salient findings of a 5 year doctoral research on criminal career development among Maltese male youth. Although the original work addressed various aspects of criminal career development, this paper will highlight those aspects of the research findings that throw light on social exclusionary processes in Maltese society that contribute to criminality. The paper explores the criminal

Marilyn Clark

328

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

2011-10-31

329

Mixed cryogen cooling systems for HTS power applications: A status report of progress in Korea University  

NASA Astrophysics Data System (ADS)

A cooling system employing a solid cryogen (SC), such as solid nitrogen (SN2), was recently reported for high-temperature superconducting (HTS) applications. However, thermal contact between the SC and the HTS can be degraded by repeated overcurrent runs, resulting in 'thermal dry-out'. Novel cryogens, SC with small amounts of liquid cryogen, have been suggested to overcome this problem. Such cooling systems rely on the small amount of liquid cryogen to facilitate heat exchange so as to fully exploit the heat capacity of the solid cryogen. This paper presents a description and summary of recent activities at Korea University related to cooling systems employing mixed cryogens of solid-liquid nitrogen, solid argon-liquid nitrogen, and solid nitrogen-liquid neon.

Song, Jung-Bin; Lee, Haigun

2012-12-01

330

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

USGS Publications Warehouse

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

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

1992-01-01

331

Détermination expérimentale du comportement mécanique et de critère de rupture d'assemblages sous chargements mixtes. Application aux rivets et points soudés  

Microsoft Academic Search

The paper deals with a new experimental procedure for joint characterisation. New experimental set-ups are based on the Arcan protocol which was first developed for composite delamination studies. This specific test enables one to mix and control the distribution of tensile and shear loads in the specimen. In the first part of the paper, a specific set-up is developed and

Bertrand Langrand; Jacky Fabis; Alain Deudon; Jean-Michel Mortier

2003-01-01

332

Intérêt d'un score de gravité des pneumonies communautaires : application du score de Fine aux pneumonies admises au centre hospitalier d'Annecy  

Microsoft Academic Search

Community-acquired pneumonia (CAP) is a common cause for hospitalization. The mean death rate (10%) varies according to the severity of the pneumonia as shown by Fine's score: less than 3% for class I to III, 8.5% for class IV, and 31% for class IV.Objective – The authors had for aim to assess the use of Fine's sore in CAP patients

J. Gaillat; C. Gros; J. B. Driencourt; P. Nicolini; A. Picard; X. Courtois; G. Genin

2002-01-01

333

Formalisme rationnel le la méthode de détermination des contraintes résiduelles par diffraction des rayons X: application aux couches minces et multicouches  

NASA Astrophysics Data System (ADS)

The use of the rational formalism in the residual stress determination method by X-ray diffraction improves the precision and the mathematical elegance of this method. It eliminates the approximations made in the conventional formalism, and corrects the results by more than 15% in certain case of thin films and multilayers. L'utilisation du formalisme rationnel dans la méthode de détermination des contraintes résiduelles par diffraction des rayons X améliore la rigueur, la précision et l'élégance mathématique de la méthode. Elle permet d'éviter les approximations faites dans le formalisme conventionnel, et apporte des corrections qui dépassent 15?% dans certains cas de couches minces et de multicouches.

Badawi, K. F.; Kahloun, C.; Grilhé, J.

1993-06-01

334

Efficacité spatiale des réseaux de transport dans une perspective de réduction drastique de l'usage de la voiture – Applications aux zones denses parisienne et lyonnaise  

Microsoft Academic Search

Durant les vingt dernières années, les politiques de déplacements urbains ont développé les réseaux de routes – autoroutes - radiales ou périphériques, ainsi que de nouveaux services de transports publics (métro, TER, tramway...). Cette amélioration constante des infrastructures de transport est au cœur des politiques puisqu'elle permet de maintenir et plus fréquemment d'augmenter la vitesse des déplacements. Or, aujourd'hui, il

Patrick Bonnel; Marie-Hélène Massot; David Caubel

2003-01-01

335

Méthode des réseaux de neurones pour le calcul des coefficients de vitesse. Application aux écoulements de l'air dans les bâtiments  

Microsoft Academic Search

In the first part of this paper, the authors present shortly the main tools used to predict airflow inside buildings. This description of the available tools allows to define the context in which they frame their works, the theoretical approach being unusual. The article deals with the exploitation of the so-called behavioural models, for the velocity coefficients calculation inside buildings.

Gérard Krauss; Patrick Depecker; Jeffrey Ignatus Kindagen

1997-01-01

336

Cartographie de l'elevation de l'interface eau douce-eau salee aux iles-de-la-madeleine par la methode electromagnetique transitoire (TEM)  

NASA Astrophysics Data System (ADS)

This research project is dedicated to mapping the elevation of the freshwater-saltwater interface in Magdalen Islands using the transient electromagnetic method (TEM) in order to monitor time-varying quality of groundwater tables. Seventy-three TEM soundings were conducted between May 2010 and June 2011 close to Well regions in Fatima, Étang-du-Nord, Havre-Aux-Maisons, Grande-Entrée and Grosse-Île. TEM soundings were carried out with loops of 50 m x 50 m and 60 m x 40 m x 2 turns except some surveys of 100 m x 100 m. To control water quality and help constrain the interpretation of TEM soundings, conductivity logs were made in four previous exploration wells and fifteen wells drilled in 2009. Results show that saline water is associated with a low resistivity level between 2 and 4 ?.m and its elevation ranges from -40 m at Grand-Entrée and more than -250 m at Havre-Aubert. In Étang-du-Nord east, Fatima east and Grande-Entrée, saline water is shallow near shore and plunges inward as expected by the Ghyben Herzberg relation. These three areas have been identified to achieve the time-lapse monitoring of groundwater because of the risk associated with the proximity of wells in operation and the low elevation of saline water. Fatima center area close to FAT03 and FAT07 soundings and Havre-Aux-Maisons showed inconsistent results with the hydrogeological model, further work is recommended to verify the origin of the conductive areas highlighted. However, the results of the interpretation of areas at Havre-Aubert and Grosse-Île did not show a risk of contamination due to the depth of saline water. Modeling of the transition zone between the freshwater aquifer and the saline groundwater has demonstrated that it was difficult to solve it for thicknesses below 10 m and 30 m to depths of 40 and 130 m respectively. If the resistivity of the transition zone is known, the resolution is improved (5 and 10 m respectively). TEM soundings showed negative responses at late time associated with induced polarization (IP) effects. The inversion results of TEM soundings affected by this effect have shown that this dispersion most likely originates from near-surface layers. Chargeabilities ranging from 0.8 to 0.9 were obtained on the TEM soundings processed. The origin of this chargeability is currently unknown but could be related to the presence of fine material (clay). IP effect has not prevented determination of the saline water to a maximum depth of 250 m. The laboratory tests on core samples were unfortunately not able to determine the relationship between resistivity and water resistivity of saturated red sandstone. Immersion of cores in deionized water failed to eliminate the salt present in it. For time-varying monitoring of groundwater, we recommend performing drilling through the interface between freshwater and saltwater on selected areas, to conduct conductivity logs to fully characterize the level of this interface, to install multiparameter probes (conductivity, temperature, pressure) in monitoring wells located at different levels and to locate sites of TEM soundings in the vicinity that will be used to monitor the groundwater.

Madani, Abdelhamid

337

Pulsed laser-induced evaporation of liquids and its applications  

NASA Astrophysics Data System (ADS)

The interaction of laser irradiation with materials is very important in a variety of laser-based manufacturing processes and scientific studies. Particularly, the interaction of a short laser pulse with absorbing liquids or solid materials in contact with liquid is central to a number of applications, including laser cleaning of microcontaminants, pulsed laser deposition of thin film materials, laser tissue removal, and laser surface texturing. In this dissertation, experimental and theoretical works on the following topics are summarized: (1) physical mechanisms of pulsed laser induced ablation of absorbing liquids at laser fluence below the plasma ignition threshold, (2) analysis of rapid vaporization at the absorbing solid/transparent liquid interface, (3) laser cleaning of surface contaminates. Concerning the first topic, the near-threshold ablation process at low laser fluences and the high power explosive vaporization process accompanying subsequent ablation plume dynamics are elucidated. Acoustic-wave detection by a piezoelectric pressure transducer, visualization by laser flash photography, and optical reflection/transmission measurements are carried out for the in-situ diagnosis of the process. Quantification of the acoustic-field generation and detection of the bubble-nucleation dynamics in the rapid vaporization at the solid liquid interface are performed by photoacoustic beam deflection technique and optical interferometry, respectively. Finally, experiments are carried out for the development of a practical laser cleaning tool and the analysis of the contaminant-removal mechanism. The results show that the near-threshold ablation by a short laser pulse is initiated by the tensile component of the thermoelastic stress without significant increase of liquid temperature at low laser fluences. On the other hand, if the heating rate is rapid enough to achieve high degree of superheating of the liquid, explosive vaporization takes place due to the abrupt increase of homogeneous-bubble-nucleation rate. This mechanism then plays the major role in the ablation dynamics. In the case of low-power gradual heating, ablation is largely an isobaric thermal vaporization process, initiated at the saturation temperature. Pulsed laser induced vaporization of liquid at the solid/liquid interface occurs with a high degree of superheating of liquid. Enhancement in the acoustic energy conversion efficiency is observed due to the rapid bubble growth in the initial stage. The pressure measurements reveal that a compressive pressure wave packet is radiated from the water-solid interface with the peak intensity of the order of 1 MPa in the far field. Comparison of the results from interferomety with those from the optical reflectance and forward scattering measurements suggests that separate bubbles begin to grow in the early stage right after the laser-pulse irradiation and that they tend to coalesce in a later stage. The laser cleaning tests confirm that the acoustic field augmentation by explosive vaporization at the solid/liquid interface can be utilized to remove submicron-sized particles from solid surfaces. The result demonstrates the feasibility of successful implementation of laser cleaning technology in the industrial cleaning process for microcontaminant removal.

Kim, Dongsik

338

Mineral Mapping and Applications of Imaging Spectroscopy  

Microsoft Academic Search

Spectroscopy is a tool that has been used for decades to identify, understand, and quantify solid, liquid, or gaseous materials, especially in the laboratory. In disciplines ranging from astronomy to chemistry, spectroscopic measurements are used to detect absorption and emission features due to specific chemical bonds, and detailed analyses are used to determine the abundance and physical state of the

Roger N. Clark; Joe Boardman; J. Mustard; F. Kruse; Cindy Ong; Carle Pieters; Gregg A. Swayze

2006-01-01

339

Allergie aux pollens de Cyprès  

Microsoft Academic Search

Cupressaceae pollen allergy has increased in the Mediterranean region in recent decades. This allergy constitutes one of the few causes of respiratory allergy of winter. With regards to its clinical manifestations, rhinitis and conjunctivitis are more frequent than asthma. There has been a progressive increase in the total and annual concentration of Cupressaceae pollen, the reasons for which are the

R. Ariano

2008-01-01

340

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

2005-11-21

341

Modele aux Tensions de Reynolds sur Maillages Structures Non-Orthogonaux: Application a UN Ecoulement Dens UN Faisceau de Tubes en Quinconce (Model of Reynolds Stress on Nonorthogonal Grid Structures: Application to a Staggered Tube Bundle).  

National Technical Information Service (NTIS)

The state of the art of models are reviewed. Developments in second order closing models are traced, highlighting their constraints, and an insight into new models whose complexity does not yet enable the generalization of wall flow is given. The adaptati...

S. Sebag

1991-01-01

342

Application du concept d'integrale J dans l'outil Aramis aux effets de mismatch sur des eprouvettes CCP. (Application of the simplified J-estimation scheme Aramis to mismatching welds in CCP).  

National Technical Information Service (NTIS)

The J-based criteria give reasonable predictions of the failure behaviour of ductile cracked metallic structures, even if the material characterization may be sensitive to the size of the specimens. However in cracked welds, this phenomenon due to stress ...

C. Eripret C. Franco P. Gilles

1995-01-01

343

Advanced in situ spectroscopic techniques and their applications in environmental biogeochemistry: introduction to the special section.  

PubMed

Understanding the molecular-scale complexities and interplay of chemical and biological processes of contaminants at solid, liquid, and gas interfaces is a fundamental and crucial element to enhance our understanding of anthropogenic environmental impacts. The ability to describe the complexity of environmental biogeochemical reaction mechanisms relies on our analytical ability through the application and developmemnt of advanced spectroscopic techniques. Accompanying this introductory article are nine papers that either review advanced in situ spectroscopic methods or present original research utilizing these techniques. This collection of articles summarizes the challenges facing environmental biogeochemistry, highlights the recent advances and scientific gaps, and provides an outlook into future research that may benefit from the use of in situ spectroscopic approaches. The use of synchrotron-based techniques and other methods are discussed in detail, as is the importance to integrate multiple analytical approaches to confirm results of complementary procedures or to fill data gaps. We also argue that future direction in research will be driven, in addition to recent analytical developments, by emerging factors such as the need for risk assessment of new materials (i.e., nanotechnologies) and the realization that biogeochemical processes need to be investigated in situ under environmentally relevant conditions. PMID:21546653

Lombi, Enzo; Hettiarachchi, Ganga M; Scheckel, Kirk G

344

Sarar technology for the application of Copper-64 in biology and materials science.  

PubMed

This review provides an overview of the synthesis and metal complexation chemistry of the nitrogen and sulphur donor bicyclic ligands or cages, and the key criteria that led to the design of sarar for the application for (64)Cu(II). Aspects of the high yielding synthesis of sarar and strategies for its conjugation to a range of antibodies for targeting colorectal cancer, neuroblastoma and melanoma are described. Free and conjugated to proteins sarar can complex (64)Cu(II) rapidly at room temperature and quantitatively; the latter leading to products of high specific activity and purity. The full occupation of the (64)Cu(II) ions 6 coordination sites by the sarar cage prevents the ready exchange of the (64)Cu(II) from the cage and is the rational for the extraordinary thermodynamic and kinetic stability of (64)Cu(II) labelled sarar and its conjugates. It's in vivo stability is further highlighted by the low uptake and retention of (64)Cu-sarar-conjugated antibodies in the liver. Finally, the prospects for the use of the sarar technology in the materials science arena for probing solid liquid interfaces, in particular, the quantification of functional groups on microspheres and in the engineering of novel materials are discussed. PMID:18174877

Smith, S V

2008-01-05

345

2.6 Quartz Crystal Microbalance for Bioanalytical Applications  

Microsoft Academic Search

The quartz crystal microbalance (QCM) was first introduced as a mass sensor in gas phase and in vacuum. Since oscillator circuits capable of exciting shear vibrations of quartz resonators under liquid load have been developed, the QCM became accepted as a new powerful tech- nique to monitor adsorption processes at solid\\/liquid interfaces in chem- ical and biological research rendering the

Physikalische Chemie

346

ADSORPTION OF SURFACTANTS AND POLYMERS AT THE SOLID-LIQUID INTERFACE. (R823301)  

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

347

Heat transfer dynamics associated with the simultaneous growth of solid–liquid melt layers  

Microsoft Academic Search

A computational model is developed to study the effects of alumina layer formation on an ablative surface, when exposed to high temperature particle laden gas flow. The one-dimensional model is developed taking into consideration the thermal loading, particle loading and the temperature dependence of the thermo-physical properties of alumina. A fully implicit finite volume method is used to solve the

Thirunavukarasu Bala; Deborah V. Pence; James A. Liburdy

2004-01-01

348

The semi-ideal solution theory for mixed ionic solutions at solid-liquid-vapor equilibrium.  

PubMed

The semi-ideal solution theory has been presented to describe the changes in thermodynamic properties accompanying the process of mixing the nonideal electrolyte solutions M(i)X(i)-(NY)sat-H2O (i = 1 and 2) at constant activities of NY and H2O, including concentration, chemical potential, activities of all M(i)X(i), Gibbs free energy, enthalpy, entropy, thermal properties, and volumetric properties. The theory states that, under the conditions of equal activities of NY and H2O, the average hydration numbers characterizing the ion-solvent interactions have the same values in the mixture as in the subsystems and the process of mixing these nonideal electrolyte solutions is as simple as that of mixing the ideal solutions if the contributions from the ion-ion interactions to the solvent activity are assumed to be the same in the mixture as in its subsystems, which has been justified by the calculations of the Pitzer equation. Therefore, a series of novel linear equations are established for the thermodynamic properties accompanying the process of mixing these nonideal solutions as well as mixing the ideal solutions M(i)X(i)-(NY)sat-H2O (i = 1 and 2) of equal mole fractions of NY and H2O. From these equations, the widely applied empirical Zdanovskii's rule is derived theoretically, and the important constant in the McKay-Perring equation under isopiestic equilibrium is determined theoretically, which has been substantiated by comparisons with the experimental results for 18 mixtures reported in the literature. Isopiestic measurements have been made for the systems BaCl2-LaCl3-H2O, NaCl-BaCl2-LaCl3-H2O, and NaCl-LaCl3-BaCl2.2H2O(sat)-H2O at 298.15 K. The results are used to test the novel linear concentration relations, and the agreement is excellent. The novel predictive equation for the activity coefficient of M(i)X(i) in M1X1-M2X2-(NY)sat-H2O has been compared with the calculations of the Pitzer equation, and the agreement is good. PMID:16553381

Hu, Yu-Feng; Fan, Shuan-Shi; Liang, De-Qing

2006-03-30

349

Solid-liquid contacting in industrial crystallizers and its influence on product size distribution  

NASA Astrophysics Data System (ADS)

The population balance concept, nucleation kinetics, growth and dissolution of sodium chloride crystals, a pilot plant crystallizer with double radial inlet are discussed, and the effect of crystallizer geometry on crystallizer performance.

Grootscholten, P. A. M.

1982-08-01

350

Phase transformation studies at the solid\\/liquid interface by directional solidification of Alloy 718  

Microsoft Academic Search

The phase transformation temperatures are especially important in alloy 718 because it requires careful heattreatment cycles.\\u000a The DTA method is generally used to estimate the characteristic temperatures of phase transformations. However, DTA is an\\u000a indirect method to confirm phase transformations, and there are always discrepancies in analyzing the DTA thermograms. In\\u000a this study, the directional solidification and quenching technique has

Dong-Kyu Oh; Chang-Yong Jo; Hyun-Choul Kim; Je-Hyun Lee; Sang-Lae Lee

2000-01-01

351

How Zr/Hf and gd Anomaly Signatures can Depict Solid-Liquid Interactions in Seawater  

NASA Astrophysics Data System (ADS)

Natural positive La, Gd e Lu anomalies in seawater have been explained by larger stability of these elements in dissolved phase with respect to the neighbor Lanthanides, when these elements are not related to anthropogenic input (Kulaksiz and Bau, 2011 and references therein). Here we report original measurements based on the systematic investigation of Earth Rare Elements, Zr and Hf concentrations in the water column of Mediterranean Sea indicating the occurrence of positive Gd anomalies in open marine conditions. Obtained results indicate that amplitudes of positive Gd anomaly are strongly linearly related to Zr/Hf ratio values in shallowest water layers from (0-200 m depth) and at the oxic seawater-anoxic brine interface (3200-3400 m depth), whereas this relationship disappears along the oxic seawater column (200-3200 m depth). Several papers investigated implications of occurrence of suspended Mn oxides and Fe-oxyhydroxides in particulates of seawater column on the dissolved REE distribution mainly according to laboratory experiments (Bau and Koschinsky, 2009 and references therein), whereas the aqueous behaviour of tetravalent Zr and Hf was essentially related to processes occurring onto hydrous Fe oxides surfaces (Bau and Koschinsky, 2006). Therefore the recognition of the above mentioned relationship between Gd/Gd* and Zr/Hf in seawater indicates that REE, Zr and Hf fates are driven by the same phenomenon, namely the scavenging onto Fe-oxyhydroxides. These materials certainly play an important role both in shallow waters because they are main components of Fe-rich coating of atmospheric dust that dissolves therein inducing the early formation of authigenic Fe-oxyhydroxides. Moreover Fe rich antigenic materials sinking along the water column dissolve at seawater-brine interface where redox Fe cycling occurs and poorly soluble Fe(II)-bearing phases can crystallize in brines under reductive conditions. On the contrary the Zr/Hf vs. Gd/Gd* linear relationship is not statistically significant along the oxic water column from 200 to 3200 m depth suggesting that further processes, probably related to migrations of water masses, took place under these conditions. These results represent an interesting goal because indicate that dissolved REE, Zr and Hf behaviour under true natural conditions in marine systems is driven by scavenging processes onto Fe-oxyhydroxides.

Censi, P.; Raso, M.; Saiano, F.; Zuddas, P.

2012-04-01

352

Theory for Relative Strengths of Trapping of He + Ions in Solid, Liquid and Gaseous Hydrogen  

Microsoft Academic Search

The study of trapping of He+ ion in solid hydrogen is important both as a problem in solid state physics and also as an applied physics problem in the\\u000a field of muon catalyzed fusion (?CF). In ?CF, He+ ion acts as a trap for ??, interrupting the chain reaction aspect of the catalytic role of ?? in producing fusion of

R. H. Scheicher; A. N. U. Roy; T. P. Das; K. Ishida; T. Matsuzaki; S. N. Nakamura; N. Kawamura; K. Nagamine

2001-01-01

353

Comparison of the effects of ultrasound and mechanical agitation on a reacting solid-liquid system  

Microsoft Academic Search

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 its chemical or mechanical effects, or to both simultaneously. The chemical effects of ultrasound are due to the implosion of microbubbles, generating free-radicals with a great

Leigh C. Hagenson; L. K. Doraiswamy

1998-01-01

354

Using Peltier Cells to Study Solid-Liquid-Vapour Transitions and Supercooling  

ERIC Educational Resources Information Center

|We propose an apparatus for teaching experimental thermodynamics in undergraduate introductory courses, using thermoelectric modules and a real-time data acquisition system. The device may be made at low cost, still providing an easy approach to the investigation of liquid-solid and liquid-vapour phase transitions and of metastable states…

Torzo, Giacomo; Soletta, Isabella; Branca, Mario

2007-01-01

355

Common potholes in modeling solid–liquid reactions—methods for avoiding them  

Microsoft Academic Search

The reaction rate of a solid in fluids depends on the reactive surface area rather than its concentration. Even though, analytical techniques have been developed enormously during the past decades, the reliable quantification of solid surface areas during a reaction still remains a challenge. Due to this, still today indirect methods such as test plots play a key role in

Henrik Grénman; Malin Ingves; Johan Wärnå; Jukka Corander; Dmitry Yu. Murzin; Tapio Salmi

2011-01-01

356

Surface induced changes in coumarin solvation and photochemistry at polar solid/liquid interfaces.  

PubMed

Steady state and time-resolved fluorescence measurements compare the photophysical properties of Coumarin 152 (C152) and Coumarin 461 (C461) in bulk methanol solution and adsorbed to silica/vapor and silica/methanol interfaces. C152 and C461 share the same structure except for a -CF(3) (C152) or -CH(3) (C461) group at the molecule's 4-position. This modest structural difference leads to markedly different emission behavior in bulk solution and different organization when adsorbed to silica surfaces. Steady state emission spectra of C152 and C461 adsorbed to silica surfaces from bulk methanol solutions show that the two solutes have similar surface activities (?G(ads) of -29.0 kJ/mol and -30.8 kJ/mol for C152 and C461, respectively) and that the interface itself has a polarity similar to that of short chain alcohols. Both solutes appear to form multilayers at higher bulk concentrations given observed linear growth in fluorescence emission intensities. At higher C152 surface concentrations a second emissive state appears at longer wavelengths, whereas the emission of C461 remains dominated by a single feature. Time dependent emission of C152 and C461 adsorbed to the silica/methanol interface shows that the silica surface inhibits C152's fast, nonradiative pathway inferred from bulk solution measurements but the fluorescence lifetime of adsorbed C461 remains unchanged from bulk solution limits. These findings are discussed in terms of the interface's ability to restrict C152 isomerization into a nonradiative, twisted intramolecular charge-transfer (TICT) state, despite the fact that this conformation represents an energetic minimum in polar solvation environments. PMID:21750805

Roy, Debjani; Piontek, Stefan; Walker, Robert A

2011-07-13

357

Generation of Equally Sized Particle Plaques Using Solid-Liquid Suspensions  

Microsoft Academic Search

A device is presented for the generation of equally sized plaques of sensitive particles in a 96-well format. The resulting particle plaques can be used for the measurement of adsorption isotherms and uptake kinetics in protein chromatography or for immobilization reactions. The particle plaques are formed from suspensions with a vacuum device that is designed as a reusable sandwich module.

Tim Herrmann; M. Schroder; J. Hubbuch

2006-01-01

358

Using Peltier Cells to Study Solid-Liquid-Vapour Transitions and Supercooling  

ERIC Educational Resources Information Center

We propose an apparatus for teaching experimental thermodynamics in undergraduate introductory courses, using thermoelectric modules and a real-time data acquisition system. The device may be made at low cost, still providing an easy approach to the investigation of liquid-solid and liquid-vapour phase transitions and of metastable states…

Torzo, Giacomo; Soletta, Isabella; Branca, Mario

2007-01-01

359

Direct quantification of ordering at a solid-liquid interface using aberration corrected transmission electron microscopy.  

PubMed

We have used aberration corrected in situ transmission electron microscopy to study the interface between liquid Al and different sapphire facet planes, including quantitative analysis of the degree of residual contrast delocalization, ensuring that the experimental contrast perturbations can be associated with density perturbations in the liquid. The results confirm that the liquid is ordered at the interface, and the degree of ordering varies as a function of the sapphire facet planes, with a decreasing degree of order according to (0006) >(1210) >(1012) ? (1014). PMID:23473172

Gandman, Maria; Kauffmann, Yaron; Koch, Christoph T; Kaplan, Wayne D

2013-02-20

360

Direct calculation of the solid-liquid Gibbs free energy difference in a single equilibrium simulation.  

PubMed

Computing phase diagrams of model systems is an essential part of computational condensed matter physics. In this paper, we discuss in detail the interface pinning (IP) method for calculation of the Gibbs free energy difference between a solid and a liquid. This is done in a single equilibrium simulation by applying a harmonic field that biases the system towards two-phase configurations. The Gibbs free energy difference between the phases is determined from the average force that the applied field exerts on the system. As a test system, we study the Lennard-Jones model. It is shown that the coexistence line can be computed efficiently to a high precision when the IP method is combined with the Newton-Raphson method for finding roots. Statistical and systematic errors are investigated. Advantages and drawbacks of the IP method are discussed. The high pressure part of the temperature-density coexistence region is outlined by isomorphs. PMID:24050323

Pedersen, Ulf R

2013-09-14

361

Simulation of microsegregation and the solid\\/liquid interface progression in the concentric solidification technique  

Microsoft Academic Search

A concentric solidification technique was employed to simulate experimentally the segregation of alloying elements during solidification at the centerline of continuously cast steel. Microstructural development of low carbon steel upon solidification has been observed in situ in a laser-scanning confocal microscope. Microscopic analyses following in situ observations, demonstrate that segregation occurring at steel slabs can reasonably be simulated by the

Sima Aminorroaya; Mark Reid; Rian Dippenaar

2011-01-01

362

Influence of the Fractal Character of Model Substances on their Reactivity at Solid–Liquid Interfaces  

Microsoft Academic Search

The fractal theory has been applied to study surface complexity where surface aspects influence physical properties and play a role in controlling heterogeneous reactions at interfaces. In this work, the influence of the fractal character of some selected antacids was investigated in regard to their neutralizing activity. The materials used were magnesium trisilicate, magnesium hydroxide, and heavy and light magnesium

Névine Rizkalla; Patrice Hildgen; Roch Thibert

1999-01-01

363

Measurement of solid-liquid interface temperature during pulsed excimer laser melting of polycrystalline silicon films  

Microsoft Academic Search

Surface melting of semiconductor materials by pulsed excimer lasers has been studied extensively in the literature. In most cases, rapid melting and resolidification induced by the pulsed excimer laser irradiation is understood as a one- dimensional process. The excimer laser irradiation offers a well controlled experimental technique for the study of the interface response when the local equilibrium conditions are

Xianfan Xu; Costas P. Grigoropoulos; Richard E. Russo

364

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...

365

Simulation of microsegregation and the solid/liquid interface progression in the concentric solidification technique  

NASA Astrophysics Data System (ADS)

A concentric solidification technique was employed to simulate experimentally the segregation of alloying elements during solidification at the centerline of continuously cast steel. Microstructural development of low carbon steel upon solidification has been observed in situ in a laser-scanning confocal microscope. Microscopic analyses following in situ observations, demonstrate that segregation occurring at steel slabs can reasonably be simulated by the use of the concentric solidification technique. The validity of these experimental simulations has been correlated with mathematical analyses using the Thermo-Calc and DICTRA (Diffusion Controlled Transformation) modeling tools. The effect of cooling rate on the sequence of events during solidification of Fe-0.18%C and Fe-4.2 wt%Ni peritectic alloys was studied and compared with the experimental observations.

Aminorroaya, Sima; Reid, Mark; Dippenaar, Rian

2011-03-01

366

Analysis of Alternative Solid/Liquid Separation Techniques in Non-Beverage Fermentation Ethanol Production.  

National Technical Information Service (NTIS)

The biochemical and process design implications of separation alternatives were analyzed. Standard batches of corn mash were prepared and the solids and liquids were separated according to three alternative sequences: (1) prior to fermentation; (2) after ...

1982-01-01

367

Analysis of alternative solid/liquid separation techniques in non-beverage fermentation ethanol production  

SciTech Connect

The biochemical and process design implications of separation alternatives were analyzed. Standard batches of corn mash were prepared and the solids and liquids were separated according to three alternative sequences: (1) prior to fermentation; (2) after fermentation; and (3) after distillation. Separation methods, such as screening, filtration, and centrifugation were also examined. Biochemical tests on the supernatants and precipitates identified the effects on total precipitate, carbohydrate, protein, reducing sugars, digestible nutrients, fiber, fat, ash, nitrogen free extract, Kjeldehl nitrogen, calcium, phosphorus, potassium, pH, BOD, specific gravity, viscosity, yeast cell number, starch, dissolved oxygen, percent alcohol, percent moisture and ethanol yield. The biochemical tests demonstrate that, depending on the effectiveness of additional product recovery steps, significant variances in ethanol yields may occur as a result of separation sequence and methodology. Highest ethanol yields without additional product recovery steps were obtained using the after distillation separation sequence.

Not Available

1982-06-01

368

SOLID-LIQUID SEPARATION OF SWINE MANURE WITH POLYMER TREATMENT AND SAND FILTRATION  

Microsoft Academic Search

Small particles typical of liquid swine manure often clog sand filter beds and fine filters. We evaluated the effec- tiveness of polymer flocculants to improve drainage and filtration performance of sand filter beds by increasing the particle size of manure. A pilot separation unit was evaluated at the Swine Unit of the NCSU Lake Wheeler Road Laboratory in Ra- leigh,

M. B. Vanotti; J. M. Rice; A. Q. Ellison; P. G. Hunt; F. J. Humenik; C. L. Baird

369

Potential of solid-liquid separation of swine wastes for methane production  

SciTech Connect

The feasibility of using a vibrating screen separator to concentrate flushed swine waste for use in an anaerobic digestor system is evaluated on the basis of the properties of the solid separator Four flowrates (37.5, 75, 112.5, and 150 L/min) and five screen mesh sizes (8,18, 30, 60, and 150) were combined for trial runs on a 45.7 cum diameter Sweco vibrating separator. The waste was obtained from a finishing house flushing waste disposal system. Analysis of the flushed waste, and the liquid and solid separate included total solids (TS), volatile solids (VS), fixed solids (FS), total carbon (TC), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN-N), ammonia (NH3-N), total (TP-P) and orthophosphate (OP-P). Mass balances calculated from the results of the different combinations of flowrate and screen size in the continuous flow system showed that the total amount of organic material (measured as volatile solids) retained on the screens varied from 17 to 70%, TKN-N varied from 2.5 to 50%, NH3-N from 3 to 47%, and ortho-phosphate from 9 to 57% with increasing screen mesh and flowrate. (Refs. 11).

Holmberg, R.D.; Hill, D.T.; Prince, T.J.; Van Dyke, N.J.

1983-01-01

370

Direct calculation of the solid-liquid Gibbs free energy difference in a single equilibrium simulation  

NASA Astrophysics Data System (ADS)

Computing phase diagrams of model systems is an essential part of computational condensed matter physics. In this paper, we discuss in detail the interface pinning (IP) method for calculation of the Gibbs free energy difference between a solid and a liquid. This is done in a single equilibrium simulation by applying a harmonic field that biases the system towards two-phase configurations. The Gibbs free energy difference between the phases is determined from the average force that the applied field exerts on the system. As a test system, we study the Lennard-Jones model. It is shown that the coexistence line can be computed efficiently to a high precision when the IP method is combined with the Newton-Raphson method for finding roots. Statistical and systematic errors are investigated. Advantages and drawbacks of the IP method are discussed. The high pressure part of the temperature-density coexistence region is outlined by isomorphs.

Pedersen, Ulf R.

2013-09-01

371

The Study of Sonar for Imaging of the Solid-Liquid Interface Inside Large Tanks  

Microsoft Academic Search

Retrieval, treatment, and disposal of high-level radioactive waste (HLW) is expected to cost between 100 and 300 billion dollars. The risk to workers, public health, and the environment are also a major area of concern for HLW. Visualization of the interface between settled solids and the optically opaque liquid is needed for retrieval of the waste from underground storage tanks.

Nitin Sood

2005-01-01

372

Solid-liquid adsorption of calcium phosphate on TiO{sub 2}  

SciTech Connect

Calcium phosphate (CP) in aqueous solution was exposed to thin-film TiO{sub 2} surfaces at predetermined times ranging from 10 min to 20 h using a liquid reaction apparatus (LRA). Surface analysis was then performed using X-ray photoelectron (XPS) and Auger electron (AES) spectroscopies and time-of-flight secondary ion mass spectromemtry (ToF-SIMS) with polyatomic primary ions. XPS revealed that CP nucleated and grew on the TiO{sub 2} surface, with phosphate groups growing on top of an initial 2-dimensional (2D) Ca-rich layer. AES depth profiling of a 4-h solution exposure complemented this finding and gave additional evidence for 3-dimensional (3D) phosphate islands forming on top of the calcium. ToF-SIMS analysis of CP adsorbed on the surface indicated that the predominant phase on the surface was brushite, CaHPO{sub 4}{sm{underscore}bullet}2H{sub 2}O. A model for Ca{sup 2+} cation bridging at the oxide interface is proposed.

Chusuei, C.C.; Goodman, D.W.; Stipdonk, M.J. van; Justes, D.R.; Loh, K.H.; Schweikert, E.A.

1999-10-12

373

Band gaps of acoustic waves propagating in a solid/liquid phononic Fibonacci structure  

NASA Astrophysics Data System (ADS)

We study the acoustic-phonon transmission spectra in quasiperiodic (Fibonacci type) superlattices made up from the solid crystal quartz and the liquid mercury (Hg). The phonon dynamics is described by a coupled elastic equations within the static field approximation model. We use a transfer-matrix treatment to simplify the algebra, which would be otherwise quite complicated, allowing a neat analytical expression for the phonon transmission coefficients. Numerical results is presented and discussed for both the transmittance spectra as well as the localization factor derived from the Lyapunov exponent, showing that the Fibonacci quasiperiodic structure acts as a filter for the phonon's transmission spectra.

Albuquerque, E. L.; Sesion, P. D.

2010-09-01

374

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

SciTech Connect

None of the models available in the literature are known to work very well for aromatic compounds such as the ones that occur in coal derived materials. Two models - one by Van Velzen et al. (Ind Eng. Chem. Fundam. Vol 11, 1972, pp. 20-25) using a group contribution method and the other by Hwang et al (Ind. Eng. Chem. Process Des. Dev., Vol. 21, 1982, pp. 127-134) using a corresponding states method - were tested for some typical compounds that occur in coal liquids. These methods give errors ranging from 10 to 50% for viscosities of such compounds. These errors are too high and considering further errors in extension of these models to coal liquids, these models were considered unacceptable in our work. We have therefore set out to develop a new model for viscosities of aromatic compounds. We plan to base the model on the procedure similar to that of Van Velzen, however developed for just aromatic compounds. Our model, once developed will therefore be a group contribution method centered around the benzene ring structure.

Kabadi, V.N.; Ilias, S.

1992-01-01

375

Emergence of the collective-response of granular solid - liquid mixtures to wave- pulse excitations  

NASA Astrophysics Data System (ADS)

The phenomenon of emergence of new properties observed in the collection of solid particles in liquid, due to pulse-wave excitations, can be found in many macroscopic systems. In this paper the uniform mixtures of solid spherical grains in water were subjected to high intensity, 60-Volts amplitude, pulsed -Ultrasonic waves of 45 kHz peak frequency. The observed response of the mixture was imbedded in the modified transmitted pulse, and could be extracted and compared to that of a reference pulse. Analysis of the results, in the frequency and time domains, includes; Fast Fourier Transform, amplitude and phase changes, and frequency dependent attenuation. The experimental findings and numerical results show that, the response of the mixture can be made independent of the scale, up to relatively small scale. The findings also show that, several collective- response to elastic wave propagation in the crystalline solids at the atomic scale, such as; cut-off frequency, tunneling effect, and absorption and conduction bands, can also have analogous ones in intermediary, and equivalences in these relatively simple mixtures.

Tavossi, Hasson M.

2013-03-01

376

Evaluating Centrifuges for Solid-Liquid Separation in the SRS Salt Processing Program  

Microsoft Academic Search

As a pretreatment step for the caustic side solvent extraction (CSSX) flowsheet, the incoming salt solution that contains entrained sludge is contacted with monosodium titanate (MST) to adsorb strontium and actinides. The resulting slurry is filtered to remove the sludge and MST. Testing performed by the Savannah River Technology Center (SRTC) and the University of South Carolina showed cross-flow filtration

2002-01-01

377

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

378

SESAME 96170, a solid-liquid equation of state for CeO2  

SciTech Connect

I describe an equation of state (EOS) for the low-pressure solid phase and liquid phase of cerium (IV) oxide, CeO{sub 2}. The models and parameters used to calculate the EOS are presented in detail, and I compare with data for the full-density crystal. Hugoniot data are available only for high-porosity powders, and I discuss difficulties in comparing with such data. I have constructed SESAME 96170, an EOS for cerium (IV) oxide that includes the ambient solid and liquid phases. The EOS extends over the full standard SESAME range, but should not be used at low temperatures and high densities because of the lack of a high-pressure solid phase. I have described the models used to compute the three terms of the EOS (cold curve, nuclear, and thermal electronic), and I have given the parameters used in the models. They were determined by comparison with experimental data at P = 1 atm, including the constant-pressure specific heat, coefficient of thermal expansion, and melting and boiling points. The EOS compares well with data in its intended range of validity, but the presence of high-frequency optical modes in its phonon spectrum limits the agreement of our models with thermal data. The next step is to construct a multiphase EOS that includes the low- and high-pressure solid phases and the liquid. The DAC data from Duclos will most strongly constrain the parameters of the high-pressure solid. A remaining issue is the comparison of the crystal-density EOS with experimental Hugoniot data, which are taken at much lower initial data because the samples are porous powders. A satisfactory means of modeling porosity, allowing comparison of theory and experiment, has not yet been produced.

Chisolm, Eric D. [Los Alamos National Laboratory

2012-05-02

379

Using Peltier cells to study solid liquid vapour transitions and supercooling  

Microsoft Academic Search

We propose an apparatus for teaching experimental thermodynamics in undergraduate introductory courses, using thermoelectric modules and a real-time data acquisition system. The device may be made at low cost, still providing an easy approach to the investigation of liquid solid and liquid vapour phase transitions and of metastable states (supercooling). The thermoelectric module (a technological evolution of the thermocouple) is

Giacomo Torzo; Isabella Soletta; Mario Branca

2007-01-01

380

Using Peltier cells to study solid liquid vapour transitions and supercooling  

NASA Astrophysics Data System (ADS)

We propose an apparatus for teaching experimental thermodynamics in undergraduate introductory courses, using thermoelectric modules and a real-time data acquisition system. The device may be made at low cost, still providing an easy approach to the investigation of liquid solid and liquid vapour phase transitions and of metastable states (supercooling). The thermoelectric module (a technological evolution of the thermocouple) is by itself an interesting subject that offers a clear example of both thermo-electric (Seebeck effect) and electro-thermal (Peltier effect) energy transformation. We report here some cooling/heating measurements for several liquids and mixtures, including water, salt/water, ethanol/water and sodium acetate, showing how to evaluate the phenomena of freezing point depression and elevation, and how to evaluate the water latent heat.

Torzo, Giacomo; Soletta, Isabella; Branca, Mario

2007-05-01

381

Depletion at Solid-Liquid Interfaces under Shear: Flowing Hexadecane on Functionalized Surfaces  

SciTech Connect

We present a neutron reflectivity study on the interface of flowing hexadecane, which is known to exhibit surface slip on functionalized solid surfaces. The single crystalline silicon substrates are either chemically cleaned or covered by octadecyl-trichlorosilane (OTS) which result in different interfacial energies in respect to hexadecane. The liquid is in situ sheared and the reflectivities are compared to the static case. Moreover, the temperature dependence is recorded. For both types of interface, density depleted layers are observed, but shear affects them differently. Whereas at the attractive surface the depletion is enhanced by shear, the low interfacial energy leads to a diminishment of the depleted layer when applying shear. This systematic change of the depletion layer indicates different structural rearrangements under shear load. Finally, the possible link of the depletion layer with surface slip is discussed.

Guttfreund, Philipp [Ruhr University, Bochum, Germany; Wolff, Max [Uppsala University, Uppsala, Sweden; Maccarini, Marco [Institut Laue-Langevin (ILL); Gerth, Stefan [Universitat Erlangen, Germany; Ankner, John Francis [ORNL; Browning, Jim [ORNL; Halbert, Candice E [ORNL; Wacklin, Hanna [Institut Laue-Langevin (ILL); Zabel, Hartmut [Ruhr University, Bochum, Germany

2011-01-01

382

Feature of solid-liquid metals reaction revealed by conversion electron Mössbauer spectrometry  

NASA Astrophysics Data System (ADS)

Selective electrolytic dissolution of the ?-zinc layer of continuous galvanized steel sheet has been utilized to uncover the Fe-Al intermetallic layer which inhibits the formation of other binary Fe-Zn intermetallic compounds. The characterization of the Fe-Al-Zn compounds by scanning electron microscopy, Mössbauer spectrometry and semi-grazing X-ray diffraction brings new enlightment about the conditions which control nucleation and growth as well as collapse of the inhibition layer and the resulting morphology of the coating.

Avettand-Fenoel, Marie-Noëlle; Cordier-Robert, Catherine; Guillemot, Gildas; Goodwin, Frank; Foct, Jacques

2009-04-01

383

Melting Temperature of Ice Ih calculated from coexisting solid-liquid phases  

SciTech Connect

In a previous paper we report the calculated melting temperature of the proton-disordered hexagonal ice I{sub h} using a four-site water model, the TIP4P (Ref. 2) and a five-site model, the TIP5P. In that work, we used a free-energy method. For the TIP4P model, the calculated melting temperature at 1 bar is T{sub m} = 229 {+-} 9 K, whereas for the TIP5P model, T{sub m} = 268 {+-} 6 K. For both models, the long-ranged interactions were truncated at 17 {angstrom}. Interestingly, these values of Tm are very close to T{sub m} = 232 {+-} 5 K and T{sub m} = 273.9 K reported by Sanz et al. and Vega et al. who used a slightly different free-energy method along with Ewald summation technique, although both the TIP4P and TIP5P models were originally developed for use with a truncated Coulomb interaction. The purpose of this paper is twofold: (1) to compute the melting temperature (T{sub m}) of ice I{sub h} with both TIP4P and TIP5P models by using the two-phase coexistence method and to compare with previously obtained T{sub m}; (2) to compute the T{sub m} using recently improved TIP4P and TIP5P models, namely, the TIP4P-Ew (Ref. 6) and TIP5P-Ew (Ref. 7) models. Both models are developed specifically for use with Ewald techniques. The TIP4P-Ew model, in particular, has shown substantial improvement over the original TIP4P model as it can reproduce the density maximum at about 274 K, very close to 277 K of the real water. The original TIP5P model can reproduce the measured T{sub m}. It will be of interest to see whether the improved TIP5P-Ew model can still hold the same level of prediction as far as the T{sub m} is concerned.

Wang, J. [University of Nebraska, Lincoln; Yoo, S. [University of Nebraska, Lincoln; Bai, J. [University of Nebraska, Lincoln; Morris, James R [ORNL; Zeng, X.C. [University of Nebraska, Lincoln

2005-01-01

384

Characterization of the brush regime for grafted polymer layers at the solid-liquid interface  

Microsoft Academic Search

Using small-angle neutron-scattering techniques, the scaling laws between the thickness of a grafted polymer layer h, its graft density sigma, and the molecular weight of the grafted chains M have been determined for polydimethylsiloxane chains end grafted on porous silica. The observed laws h~=Msigma in bad solvent and h~=Msigma1\\/3 in good solvent provide the first experimental evidence of the ``brush''

P. Auroy; L. Auvray; L. Léger

1991-01-01

385

Solid-liquid distribution of selected concrete admixtures in hardened cement pastes  

SciTech Connect

The distribution between hardened cement paste and cement pore water of selected concrete admixtures (BZMs), i.e., sulfonated naphthalene-formaldehyde condensate (NS), lignosulfonate (LS) and a gluconate-containing plasticiser used at the Paul Scherrer Institute for waste conditioning, was measured. Sorption data were fitted to a single-site Langmuir isotherm with affinity constants K = (19 {+-} 4) dm{sup 3} g{sup -1} for NS, K = (2.1 {+-} 0.6) dm{sup 3} g{sup -1} for LS and sorption capacities q = (81 {+-} 16) g kg{sup -1} for NS, q = (43 {+-} 8) g kg{sup -1} for LS. In the case of gluconate, a two-site Langmuir sorption model was necessary to fit the data satisfactorily. Sorption parameters for gluconate were K {sub 1} = (2 {+-} 1) x 10{sup 6} dm{sup 3} mol{sup -1} and q {sub 1} = (0.04 {+-} 0.02) mol kg{sup -1} for the stronger binding site and K {sub 2} = (2.6 {+-} 1.1) x 10{sup 3} dm{sup 3} mol{sup -1} and q {sub 2} = (0.7 {+-} 0.3) mol kg{sup -1} for the weaker binding site. Desorption of these BZMs from cement pastes and pore water in cement specimens prepared in the presence of the BZMs were then used to test the model. It was found that only minor parts of NS and LS could be mobilised as long as the cement composition was intact, whereas the sorption of gluconate was found to be reversible. The Langmuir model makes valuable predictions in the qualitative sense in that the pore water concentration of the BZMs is reduced by several orders of magnitude as compared to the initial concentrations. In view of the necessity for conservative predictions used in the safety analysis for disposal of radioactive waste, however, the predictions are unsatisfactory in that the measured pore water concentrations of NS and LS were considerably larger than the predicted values. This conclusion does not apply for gluconate, because its concentration in cement pore water was below the detection limit of {approx}50 nM.

Glaus, Martin A. [Laboratory for Waste Management, OHLD/002, Paul Scherrer Institut, CH-5232 Villigen (Switzerland)]. E-mail: martin.glaus@psi.ch; Laube, A. [Laboratory for Waste Management, OHLD/002, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Van Loon, Luc R. [Laboratory for Waste Management, OHLD/002, Paul Scherrer Institut, CH-5232 Villigen (Switzerland)

2006-07-01

386

Numerical analysis of binary solid-liquid phase change with buoyancy and surface tension driven convection  

SciTech Connect

The effects of thermo/diffusocapillary convection on the solidification of aqueous NH{sub 4}Cl in a rectangular cavity have been simulated numerically using a newly developed continuum model. Diffusocapillary convection is negligible relative to thermocapillary convection, and for a 20 {times} 20 mm cavity in a one-gravity environment, thermocapillary effects are most pronounced during the early stages of solidification, when flow conditions are characterized by three major cells. One cell, driven by solutal buoyancy forces, extends from the mush region to the melt and separates top and bottom melt region cells driven primarily by surface tension and buoyancy forces, respectively. With increasing time, however, the top cell strengthens and eventually envelops the entire melt. In terms of the strength of the flow, the liquidus front morphology, and the amount of solid formed, final conditions differ only slightly from those predicted for pure thermal/solutal convection.

Incropera, F.P.; Engel, A.H.H. (Purdue Univ., Lafayette, IN (USA). Heat Transfer Lab.); Bennon, W.D. (Alcoa Technical Center, Alcoa Center, PA (US))

1989-01-01

387

Nuclear magnetic resonance measurement of ammonia diffusion in dense solid-liquid slurries. Revision 1  

SciTech Connect

The flammability and toxicity of ammonia released from the nuclear waste tanks at Hanford have been the subject of several recent studies. These releases may occur episodically, such as the buoyant plume releases occurring in various double-shell tanks (DSTs); gradually through the surface of the waste; or from the partially saturated saltcakes in the single-shell tanks during salt-well pumping. 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 translational diffusion of the ammonium ions was determined by measuring the diffusion of nitrogen nuclei in solution. Results showed that the ammonium diffusion coefficient can be measured in aqueous solutions with concentrations as low as 20 {times} 10{sup {minus}3} {und M}. Typical values measured for the diffusion coefficient of the ammonium ion are 2 {times} 10{sup {minus}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 ammonia is less sensitive to the solution pH, extending the measurement range to pH of 9.5. The results show that the solution viscosity has a measurable 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 {micro}m 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)

1998-01-01

388

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

389

Apports du cryomicroscope électronique à balayage à émission de champ à l'étude des matières organiques et des relations organo-minérales naturelles. Application aux croûtes microbiotiques des sols  

Microsoft Academic Search

The cryo-SEM (SEM equipped with a freeze-drying sample preparation system) allows the micromorphological transformations occurring during desiccation-rewetting cycles of microbiotic crusts from Sahelian soils to be visualised, like the swelling up of mucilaginous envelopes of the constituent micro-organisms through water absorption. When the cryo-SEM is equipped with a field emission gun, which permits observations at low voltage operation (1 kV)

Christian Défarge; Oumarou Malam Issa; Jean Trichet

1999-01-01

390

BioRef: A versatile time-of-flight reflectometer for soft matter applications at Helmholtz-Zentrum Berlin  

NASA Astrophysics Data System (ADS)

BioRef is a versatile novel time-of-flight reflectometer featuring a sample environment for in situ infrared spectroscopy at the reactor neutron source BER II of the Helmholtz Zentrum Berlin für Materialien und Energie (HZB). After two years of design and construction phase the instrument has recently undergone commissioning and is now available for specular and off-specular neutron reflectivity measurements. BioRef is especially dedicated to the investigation of soft matter systems and studies at the solid-liquid interface. Due to flexible resolution modes and variable addressable wavelength bands that allow for focusing onto a selected scattering vector range, BioRef enables a broad range of surface and interface investigations and even kinetic studies with subsecond time resolution. The instrumental settings can be tailored to the specific requirements of a wide range of applications. The performance is demonstrated by several reference measurements, and the unique option of in situ on-board infrared spectroscopy is illustrated by the example of a phase transition study in a lipid multilayer film.

Strobl, M.; Steitz, R.; Kreuzer, M.; Rose, M.; Herrlich, H.; Mezei, F.; Grunze, M.; Dahint, R.

2011-05-01

391

BioRef: A versatile time-of-flight reflectometer for soft matter applications at Helmholtz-Zentrum Berlin  

SciTech Connect

BioRef is a versatile novel time-of-flight reflectometer featuring a sample environment for in situ infrared spectroscopy at the reactor neutron source BER II of the Helmholtz Zentrum Berlin fuer Materialien und Energie (HZB). After two years of design and construction phase the instrument has recently undergone commissioning and is now available for specular and off-specular neutron reflectivity measurements. BioRef is especially dedicated to the investigation of soft matter systems and studies at the solid-liquid interface. Due to flexible resolution modes and variable addressable wavelength bands that allow for focusing onto a selected scattering vector range, BioRef enables a broad range of surface and interface investigations and even kinetic studies with subsecond time resolution. The instrumental settings can be tailored to the specific requirements of a wide range of applications. The performance is demonstrated by several reference measurements, and the unique option of in situ on-board infrared spectroscopy is illustrated by the example of a phase transition study in a lipid multilayer film.

Strobl, M.; Kreuzer, M. [University of Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg (Germany); Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Steitz, R.; Rose, M.; Herrlich, H. [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Mezei, F. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Grunze, M.; Dahint, R. [University of Heidelberg, Im Neuenheimer Feld 253, 69120 Heidelberg (Germany)

2011-05-15

392

In Situ SHINERS at Electrochemical Single-Crystal Electrode/Electrolyte Interfaces: Tuning Preparation Strategies and Selected Applications.  

PubMed

We have studied Au(55 nm)@SiO2 nanoparticles (NPs) on two low-index phases of gold and platinum single crystal electrodes in ClO4(-) and SO4(2-) ion-containing electrolytes by both electrochemical methods and in-situ shell-isolated nanoparticle enhanced Raman spectroscopy (SHINERS). We showed the blocking of the electrode with surfactants originating from the synthesis of as-prepared SHINERS NPs. We introduce an efficient procedure to overcome this problem, which provides a fundamental platform for the application of SHINERS in surface electrochemistry and beyond. Our method is based on a hydrogen evolution treatment of the SHINERS-NP-modified single-crystal surfaces. The reliability of our preparation strategy is demonstrated in electrochemical SHINERS experiments on the potential-controlled adsorption and phase formation of pyridine on Au(hkl) and Pt(hkl). We obtained high-quality Raman spectra on these well-defined and structurally carefully characterized single-crystal surfaces. The analysis of the characteristic A1 vibrational modes revealed perfect agreement with the interpretation of single-crystal voltammetric and chronoamperometric experiments. Our study demonstrates that the SHINERS protocol developed in this work qualifies this Raman method as a pioneering approach with unique opportunities for in situ structure and reactivity studies at well-defined electrochemical solid/liquid interfaces. PMID:24007327

Li, Jian-Feng; Rudnev, Alexander; Fu, Yongchun; Bodappa, Nataraju; Wandlowski, Thomas

2013-09-10

393

Application Switching  

Microsoft Academic Search

\\u000a Application switching is a powerful feature that can extend your image creation and manipulation options. Aviary’s applications\\u000a are designed to be quick and simple to use; thus, many advanced features have been omitted to keep the applications nimble.\\u000a To offset this smaller feature set compared to the more expensive desktop applications, Aviary has added easy application\\u000a switching. For instance, if

Mike Peutz

394

Les recommandations de prise en charge des complications m?taboliques associ?es aux antipsychotiques de deuxi?me g?n?ration chez les enfants et les adolescents  

PubMed Central

HISTORIQUE : Les antipsychotiques de 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.

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

2012-01-01

395

[The clinical views of the humanist doctor F.P. Haas (the first quarter of the XIXth century). On the occasion of the 200th anniversary of the publication of F.P. Haas' book "Ma visite aux Eaux d'Alexandre en 1809 et 1810" (M., 1811)].  

PubMed

This paper is devoted to the analysis of clinical principles of physician humanist F.P. Haas expounded in his book "Ma visite aux Eaux d'Alexandre en 1809 at 1810" by F.P. Haas (M., 1811). The translation of this book into the Russian language gave an idea of the clinical views of the medical profession in this country in the beginning of the XIXth century (before the Patriotic War of 1812) including relationship between doctors and their patients and medical ethics. Haas proposed a well-substantiated therapeutic strategy with the use of mineral waters taking into consideration residual assimilative capacity of the patient's organism. PMID:24137939

396

Les recommandations th?rapeutiques relatives aux effets secondaires extrapyramidaux associ?s ? l'utilisation d'antipsychotiques de deuxi?me g?n?ration chez les enfants et les adolescents  

PubMed Central

HISTORIQUE ET OBJECTIF : L’utilisation d’antipsychotiques augmente chez les enfants. Le présent article visait à orienter les cliniciens quant à la prise en charge clinique des effets secondaires extrapyramidaux des antipsychotiques de deuxième génération. MÉTHODOLOGIE : Les publications, les entrevues avec des informateurs clés et des échanges avec les membres d’un groupe de discussion et les partenaires ont permis de déterminer les principaux secteurs cliniques d’orientation et les préférences quant à la structure des présentes recommandations. Les membres responsables des lignes directrices ont reçu le projet de recommandations, ont évalué l’information recueillie grâce à une analyse bibliographique systématique et ont utilisé un processus de groupe nominal pour parvenir à un consensus quant aux recommandations thérapeutiques. Les lignes directrices contiennent une description des anomalies neurologiques souvent observées avec l’utilisation d’antipsychotiques ainsi que les recommandations sur le moyen d’examiner et de quantifier ces anomalies. Une démarche séquentielle sur la prise en charge des anomalies neurologiques est présentée. RÉSULTATS : On peut observer plusieurs types de symptômes extrapyramidaux attribuables à l’utilisation d’antipsychotiques chez les enfants, y compris la dystonie aiguë, l’akathisie, le parkinsonisme et la dyskinésie tardive, toutes induites par les neuroleptiques, de même que la dystonie tardive, l’akathisie tardive et les dyskinésies de sevrage. La forte majorité des données probantes sur le traitement des troubles du mouvement induits par les antipsychotiques proviennent de patients adultes atteints de schizophrénie. Étant donné le peu de données pédiatriques, les recommandations découlent de publications portant tant sur des adultes que sur des enfants. Compte tenu des limites de généralisation des données provenant de sujets adultes pour des enfants, il faudrait évaluer ces recommandations d’après les avis d’experts plutôt que d’après les données probantes. CONCLUSION : Les cliniciens doivent savoir que les antipsychotiques de deuxième génération ont le potentiel d’induire des effets secondaires neurologiques et devraient faire preuve d’une extrême vigilance lorsqu’ils en prescrivent.

Pringsheim, Tamara; Doja, Asif; Belanger, Stacey; Patten, Scott

2012-01-01

397

Bioreactor application on adventitious root culture of Astragalus membranaceus  

Microsoft Academic Search

Astragalus membranaceus is one of the most widely used traditional medicinal herbs in China, but the time required to generate a useful product in\\u000a the field production is long. The growth of adventitious root cultures was compared between cultures grown in solid, liquid,\\u000a or a 5-L balloon-type bubble bioreactor. The maximum growth ratio (final dry weight\\/initial dry weight) was determined

Song Quan Wu; Mei Lan Lian; Ri Gao; So Young Park; Xuan Chun Piao

398

Solubility equilibria: From chemical potentiometry to industrial applications  

Microsoft Academic Search

Solubility equilibria are related to thertnodynainic properties in general and chemical po- tentials in particular of ionic compounds, nonelectrolytes and metals in aqueous solutions or melts. Solubility phenomena are most efficiently dealt with by the theoretical and graphical methods of phase theory. Master variables for the depiction of the pertinent solid-solid or solid-liquid phase diagram are deduced from generalized Gibbs-Duhem

Heinz Gamsjager

1995-01-01

399

Development of a Rotary Microfilter for SRS HLW Applications  

Microsoft Academic Search

The processing rate of Savannah River Site (SRS) high-level waste decontamination processes are limited by the flow rate of the solid-liquid separation. The baseline process, using a 0.1 micron cross-flow filter, produces approximately 0.02 gpm\\/sq. ft. of filtrate under expected operating conditions. Savannah River National Laboratory (SRNL) personnel identified the rotary microfilter as a technology that could significantly increase filter

2005-01-01

400

Development of a Rotary Microfilter for SRS HLW Applications  

Microsoft Academic Search

The processing rate of Savannah River Site high level waste decontamination processes are limited by the flow rate of the solid-liquid separation. The baseline process, using a 0.1 micron cross flow filter, produces 0.02 gpm\\/ft2 of filtrate under expected operating conditions. Savannah River National Laboratory personnel identified the rotary microfilter as a technology that could significantly increase filter flux, with

2004-01-01

401

Nanofluids: A New Field of Scientific Research and Innovative Applications  

Microsoft Academic Search

In the early 1990s, as I began exploring ways to apply nanotechnology to heat transfer engineering, I saw the possibility of breaking down the century-old technical barriers of conventional solid-liquid suspensions by stably suspending nanoparticles. During the past decade, a series of pioneering experiments have discovered that nanofluids exhibit a number of novel thermal transport phenomena. Nanofluids are of great

2008-01-01

402

Surface-immobilized PAMAM-dendrimers modified with cationic or anionic terminal functions: physicochemical surface properties and conformational changes after application of liquid interface stress.  

PubMed

Functionalization of surfaces with highly branched dendrimer molecules has gained attractiveness for various applications because the number of functional groups exceeds those of surfaces functionalized with self-assembled monolayers. So far, little is known about the physicochemical properties of dendrimer functionalized surfaces, especially if the flexibility of dendrimer structure remains after covalent immobilization. Therefore, the purpose of this study was to covalently immobilize polyamidoamine (PAMAM) dendrimer molecules exhibiting terminal amine and carboxyl groups to silicon model surfaces and to explore their properties and structure at the solid-air and solid-liquid interface. Our results show that the surface free energy is higher for PAMAM coatings than for analogously terminated SAMs and also higher for carboxyl than amine functionalized coatings. Furthermore, several findings suggest that conformational freedom of the dendrimers was preserved after surface immobilization. Wet compared to dry PAMAMNH(2) surfaces show reduced hydrophilicity and increased contact angle hysteresis, whereas PAMAMCOOH surfaces become more hydrophilic and showed decreased hysteresis. Streaming current measurements showed an unexpected behavior for PAMAMCOOH surfaces in that they reveal a net positive surface charge over a wide pH range in spite of the carboxylated periphery. All of these results indicate a certain degree of masking, burrowing, back-folding and unfolding of functional groups upon environmental changes. PMID:21999956

Katzur, Verena; Eichler, Mirjam; Deigele, Erika; Stage, Christiane; Karageorgiev, Peter; Geis-Gerstorfer, Jürgen; Schmalz, Gottfried; Ruhl, Stefan; Rupp, Frank; Müller, Rainer

2011-09-19

403

CHTN Application  

Cancer.gov

The Principal Investigator (PI) responsible for overseeing the project and controlling the laboratory and personnel who will receive, use and process the requested specimens should complete this application.

404

Latent heat storage modules for preheating internal combustion engines: application to a bus petrol engine  

Microsoft Academic Search

The heat storage (HS) system for pre-heating a bus petrol engine before its ignition was mathematically modelled and experimentally investigated. The development of such devices is an extremely urgent problem especially for regions with a cold climate. HS system working on the effect of absorption and rejection of heat during the solid-liquid phase change of HS material is realised, tested

L. L. Vasiliev; V. S. Burak; A. G. Kulakov; D. A. Mishkinis; P. V. Bohan

2000-01-01

405

A gravity independent biological grey water treatment system for space applications  

Microsoft Academic Search

Biological treatment of grey water in space presents serious challenges, stemming mainly from microgravity conditions. The major concerns are phase separation and mass transfer limitations. To overcome solid-liquid phase separation, novel immobilized cell packed bed (ICPB) bioreactors have been developed to treat synthetic grey water. Packed bed bioreactors provide a unique environment for attached microbial growth resulting in high biomass

Majda'midhat Nashashibi

2002-01-01

406

Recent Applications of Laser-Induced Breakdown Spectrometry: A Review of Material Approaches  

Microsoft Academic Search

The use of laser?induced breakdown spectrometry (LIBS) has grown steadily, and it has proven to be a relatively dynamic research activity for performing direct spectrochemical elemental or metal analysis of a variety of materials, solids, liquids, and gases, with none or little sample pretreatment procedures. Significant progress has been made during the last several years on the diverse and versatile

Jianyong Wu; Joseph Sneddon

2004-01-01

407

Application of high temperature superconductors to high-gradient magnetic separation  

Microsoft Academic Search

High Gradient Magnetic Separation (HGMS) is a powerful technique which can be used to separate widely dispersed contaminants from a host material, This technology can separate magnetic solids from other solids, liquids, or gases. As the name implies, HGMS uses large magnetic field gradients to separate ferromagnetic and paramagnetic particles. HGMS separators usually consist of a high-field solenoid magnet, the

M. A. Daugherty; F. C. Prenger; D. D. Hill; D. E. Daney; L. W. Worl; A. R. Schake; D. D. Padilla

1994-01-01

408

The application of Cold Atmospheric Plasma (CAP) for the sterilisation of spacecraft materials  

NASA Astrophysics Data System (ADS)

Plasma, oft called the fourth state of matter after solid, liquid and gas, is defined by its ionized state. Ionization can be induced by different means, such as a strong electromagnetic field applied with a microwave generator. The concentration and composition of reactive atoms and molecules produced in Cold Atmospheric Plasma (CAP) depends on the gases used, the gas flow, the power applied, the humidity level etc.. In medicine, low-temperature plasma is already used for the sterilization of surgical instruments, implants and packaging materials as plasma works at the atomic level and is able to reach all surfaces, even the interior of small hollow items like needles. Its ability to sterilise is due to the generation of biologically active bactericidal agents, such as free radicals and UV radiation. In the project PLASMA-DECON (DLR/BMWi support code 50JR1005) a prototype of a device for sterilising spacecraft material and components was built based on the surface micro-discharge (SMD) plasma technology. The produced plasma species are directed into a closed chamber which contains the parts that need to be sterilised. To test the inactivation efficiency of this new device bacterial spores were used as model organisms because in the COSPAR Planetary Protection Policy all bioburden constraints are defined with respect to the number of spores (and other heat-tolerant aerobic microorganisms). Spores from different Bacillus species and strains, i.e. wildtype strains from culture collections and isolates from spacecraft assembly cleanrooms, were dried on three different spacecraft relevant materials and exposed to CAP. The specificity, linearity, precision, and effective range of the device was investigated. From the results obtained it can be concluded that the application of CAP proved to be a suitable method for bioburden reduction / sterilisation in the frame of planetary protection measures and the design of a larger plasma device is planned in the future.

Rettberg, Petra; Barczyk, Simon; Morfill, Gregor; Thomas, Hubertus; Satoshi Shimizu, .; Shimizu, Tetsuji; Klaempfl, Tobias

2012-07-01

409

Les concomitants psychologiques aux affections cardiovasculaires  

Microsoft Academic Search

The first of these studies sampled the symptoms observed by psychiatrists in an urban population (N = 283). The second gathered information obtained from the treating doctors of inhabitants of a rural area (N = 318). All subjects, in both inquiries, were randomly selected. We considered the former data as subjective and the latter as objective. Each of these two

C. Mertens de Wilmars

1973-01-01

410

Aux origines de la science historique albanaise  

Microsoft Academic Search

Nous commençons, ce semestre, une série d'entretiens avec des historiens qui représentent dans leurs pays des références intellectuelles incontestables mais qui sont encore peu connus des jeunes historiens étrangers. Nous voudrions réfléchir avec eux sur les méthodes qu'ils utilisent ou, comme ici avec M. Aleks Buda, sur leurs parcours parce qu'ils sont représentatifs d'un milieu scientifique national, d'un type de

Marin Haxhimihali

1994-01-01

411

Les résistances aux médicaments antipaludiques  

Microsoft Academic Search

Drug resistant malaria is mostly due to Plasmodium falciparum, the highly prevalent species in tropical Africa, Amazon, and Southeast Asia. P. falciparum is responsible for severe involvement of fever or anemia causing more than a million deaths per year. Rationale for treatment is becoming weak as multiple drug resistance against well-tolerated drugs develops. P. falciparum drug resistant malaria originates from chromosomal mutations. Analyses

J. Le Bras; L. Musset; J. Clain

2006-01-01

412

Geotechnical applications  

NASA Astrophysics Data System (ADS)

Committee D18 on Soil a n d Rock of the American Society for Testing and Materials held the symposium Geotechnical Applications of Geophysics June 29 in St. Louis, Mo.Cochaired by Wayne Saunders, ICF, Inc., Fairfax, Va., and Fred Paillet, U.S. Geological Survey, Denver, Colo., 15 papers were presented from authors from Canada, Japan, and the United States.

Paillet, F. L.

413

An interface-tracking numerical method for rapid planar solidification of binary alloys with application to microsegregation  

Microsoft Academic Search

Many rapid solidification processes, such as splat cooling, melt-spinning, thermal spray deposition and laser surface melting, can result in a planar solid\\/liquid interface with a large melt undercooling at the interface. On the other hand, when cellular or dendritic solidification takes place, the solute redistribution between cells or dendrite arms can also be assumed in first approximation to be a

G.-X. Wang; V. Prasad; E. F. Matthys

1997-01-01

414

Application of response surface methodology to optimize microwave-assisted extraction of silymarin from milk thistle seeds  

Microsoft Academic Search

Milk thistle (Silybum marianum L.) is an excellent source of silymarin used as an antioxidant. Microwave-assisted extraction (MAE) was employed to extract silymarin from milk thistle seeds. The effects of four independents variables in terms of extraction time, temperature, ethanol concentration, and solid–liquid ratio on the silymarin yield were determined and the optimal conditions for silymarin were evaluated by means

Xianzhe Zheng; Xin Wang; Yubin Lan; John Shi; Sophia Jun Xue; Chenghai Liu

2009-01-01

415

Application of a Coupled Thermo-Hydro-Mechanical Model to Simulate the Drying of Nonsaturated Porous Media  

Microsoft Academic Search

This study deals with drying modeling of a partially saturated deformable porous media (solid, liquid, and gas phases). In fact, during their drying, the deformable porous media undergo stresses due to volume shrinkage. The objectives of the model are to foresee the mechanical stresses in order to control the deformations of the product. Modeling of drying has been worked out

Saber Chemkhi; Wahbi Jomaa; Féthi Zagrouba

2009-01-01

416

Gastrointestinal Applications  

Microsoft Academic Search

The origin, subtypes, physiology and pharmacology of botulinum toxin type A (BTX-A) have been discussed in other chapters.\\u000a In this chapter, some of the current applications of BTX in gastroenterology are discussed. BTX has been used for a large\\u000a number of gastrointestinal disorders, however, this chapter is confined to those conditions for which the best data are available\\u000a (achalasia, gastroparesis,

Shayan Irani; Frank K. Friedenberg

417

Les allergies aux piercings et aux tatouages : enquête du réseau d’allergo-vigilance  

Microsoft Academic Search

Piercing and tattooing are the most commonly encountered body modifications. Besides risks of infection and scarring, allergic reactions can also occur. The present multicentric study was the first carried out to evaluate the frequency of allergy consultation for such problems. Of the 138 allergists who responded to two questionnaires, 7.9% had observed allergies to piercing and 18.9% had identified an

P. Dron; M. P. Lafourcade; F. Leprince; C. Nonotte-Varly; X. Van Der Brempt; L. Banoun; I. Sullerot; C. This-Vaissette; L. Parisot; D. A. Moneret-Vautrin

2007-01-01

418

La déqualification des OGM aux yeux des consommateurs: des attitudes aux conceptions  

Microsoft Academic Search

[eng] GMO and consumers: from the attitudes to the conceptions - In the current framework of food industry, recent crisis show that agriculture is less and less «qualified» in the eyes of consumers. In the meanwhile, high quality supply chains (as red label, organic farming or designations of origin) resist quite well. An hypothetic «ogm less» supply chain seems not

Bertil Sylvander; Marc Leusie

2001-01-01

419

Essential Science for Teachers: Physical Science: Session 2. The Particle Nature of Matter: Solids, Liquids, and Gases  

NSDL National Science Digital Library

In this segment the interviewer probes the student's ideas about the arrangement and motion of particles in the 3 states of matter. When asked if atoms move, the student says in air they do but in aluminum they don't. When asked to draw, the student uses "dots" with gases spread far out, liquids closer together, and in solids he shades the picture to show that it is contiguous.

Astrophysics, Harvard-Smithsonian C.

420

Development of a concentration measurement technique for steady state solid-liquid mixing using a neural network  

NASA Astrophysics Data System (ADS)

A measurement technique that can measure the concentration of the solid particles in liquid flow was developed. The measurement system consists of a color camera and three LCD displays. The solid particles were put at the bottom of a cylindrical mixing tank in which JetA1 oil was filled. Transient mixing of the solid particles was performed by rotating a propeller type agitator with three different rotation speed (500, 600, 700 r/min). Mixing state was visualized by the LCD displays and a color camcorder. The color intensity of the glass particles changes with their concentration. The color information was decoded into three principle colors R, G, and B so that, the calibration curve of color-to-concentration was performed using these information. A neural network was used for this calibration. The transient concentration field of the solid particles was quantitatively visualized.

Doh, Deog Hee; Yum, Joo Ho; Cho, Gyeong Rae; Kim, Myung Ho; Ryu, Gyong Won; Takei, Masahiro

2013-10-01

421

Essential Science for Teachers: Physical Science: Session 2. The Particle Nature of Matter: Solids, Liquids, and Gases  

NSDL National Science Digital Library

The segment shows the interviewer asking the student whether everything is made up of atoms and to give examples of things made up of atoms. The student says that everything is made up of atoms and further clarifies that by saying that anything natural is made up of atoms. When asked for examples, the student describes several correct ones as well as an incorrect example- "fire in a light-bulb" -as being made of atoms and the interviewer tries to probe further to find out if the student thinks that a flame is made up of atoms.

Astrophysics, Harvard-Smithsonian C.

422

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

SciTech Connect

The aim of the project is to develop a knowledge base to help with the design of enhanced process for mobilizing and extracting untrapped oil. We emphasize on evaluating novel surfactant mixtures and on obtaining optimum combinations of the surfactants in chemical flooding EOR process. An understanding of the micellar shape and size is crucial since these physical properties directly determine the crude oil removal efficiency. Analytical ultracentrifugation experiments were used to test the multi-micelle model proposed earlier and formulate the relationships between mixed micelle formation and the surfactant structure. Information on partial specific volume of surfactants and their mixtures is required to treat analytical ultracentrifuge data. In the last report, it was noted that the partial specific volumes of the sugar-based surfactants obtained experimentally did not agree with those from theoretical calculations. A scrutiny of partial specific volumes of the four sugar-based surfactants revealed that conformational changes upon micelle formation are responsible for the large deviation. From sedimentation equilibrium experiments, two types of micelles were identified for the nonionic polyethylene surfactant and its mixtures with the sugar-based surfactant, dodecyl maltoside. The average aggregation numbers of n-dodecyl-{beta}-D-maltoside and nonyl phenol ethoxylated decyl ether agreed with those reported in literature using other techniques. Our study displayed, for the first time, that small micelles might coexist with large micelles at high concentrations due to unique structures of the surfactant although classical thermodynamic theory supports only one type of micelle. Initial dynamic light scattering results support the results for the same mixed surfactant system from analytical ultracentrifuge equilibrium technique. The implication of this finding lies in the fact that efficiency of oil recovery will be improved due to the large micellar size, its polymer-like fluidity and possible reduced adsorption on solids.

Prof. P. Somasundaran

2003-03-31

423

Physical Characterization of Solid-Liquid Slurries at High Weight Fractions Using Optical and Ultrasonic Methods, Final Report  

SciTech Connect

Remediation of highly radioactive waste is a major technical and programmatic challenge for the DOE. Rapid, on-line physical characterization of highly concentrated slurries is required for the safe and efficient remediation of 90 million gallons of high level radioactive waste (HLW), sodium bearing waste, and mixed waste. The research presented here, describes a collaborative effort between Pacific Northwest National Laboratory (PNNL) and the University of Washington to directly address the need for rapid on-line characterization of the physical properties of HLW slurries during all phases of the remediation process, from in-tank characterization of sediments to monitoring of the concentration, particle size, and degree of agglomeration and gelation of slurries during transport. Near-surface characterization of the slurry flow in the particle size range from nanometer to micrometer is examined using optical low coherence reflectometry. Volumetric characterization at depths in the slurry flow, up to several centimeters in the particle size range from the micrometer to millimeter, is realized by utilizing ultrasonic backscatter and diffuses fields. One of the strengths, the teaming up of significant talents in both experimental and theoretical optics (University of Washington) and in ultrasonics [Pacific Northwest National Laboratory (PNNL)] provides a synergistic approach to integrate these complimentary techniques. One of the benefits of this combined approach is the physical characterization of HLW over a concentration and particle size range that is broader than can be achieved with today’s technology. This will avoid a costly increase in waste stream volume due to excess dilution, and will lessen chance of plugging pipes that could shut down expensive processing lines.

Burgess, Lloyd W.

2009-09-17

424

Physical and Chemical Characterization and Comparison of Solids, Liquids, and Oils Derived from Estonian and Green River Formation Shales.  

National Technical Information Service (NTIS)

Although only a single Estonian raw shale sample with an unknown history has been examined, physical and chemical characterization of this material has been accomplished. A comparison with a representative Green River formation raw shale has been made. So...

E. J. Peterson W. D. Spall

1981-01-01

425

Second Harmonic Generation as a Probe of Multisite Adsorption at Solid-Liquid Interfaces of Aqueous Colloid Suspensions  

Microsoft Academic Search

Chemistry at the surface of solid particles in colloidal dispersions is important in the description of such diverse topics as nutrient and contaminant flow in the environment and the creation of better paints and cosmetics. Particles in these systems are often characterized by molecular-level, surface heterogeneity. This molecular heterogeneity influences many aspects of the chemical processes of interest, among the

R. Kramer Campen; De-sheng Zheng; Hong-fei Wang; Eric Borguet

2007-01-01

426

Inertial-microfluidic radial migration in solid\\/liquid two-phase flow through a microcapillary: Particle equilibrium position  

Microsoft Academic Search

Although equilibrium of spherical particles under radial migration has been extensively investigated, mostly in macroscale\\u000a flows with characteristic lengths on the order of centimeters, it is not fully characterized at relatively small Reynolds\\u000a numbers, 1 ? Re ? 100. This paper experimentally studies “inertial microfluidic” radial migration of spherical particles in circular Poiseuille\\u000a flow through a microcapillary. Microparticle tracking experiments are performed to obtain

Young Won Kim; Hikui Noh; Songwan Jin; Jung Yul Yoo

427

A study of the solid-liquid interface in cobalt base alloy (Stellite) coatings deposited by fusion welding (TIG)  

SciTech Connect

Microstructural features present at the interface between a weld deposited Stellite 6 hard facing and an austenitic stainless steel substrate are described. Elemental X-ray maps indicate that diffusion of carbon from the liquid Stellite to the austenitic stainless steel takes place along grain boundaries resulting in the formation of chromium carbide 'arms' that penetrate along the austenite grain boundaries in the interfacial region.

Molleda, F. [Escuela Tecnica Superior de Ingenieros Navales de Madrid (Spain)]. E-mail: fmolleda@etsin.upm.es; Mora, J. [Escuela Tecnica Superior de Ingenieros Navales de Madrid (Spain); Molleda, F.J. [ESAB Iberica (Spain); Mora, E. [Escuela Tecnica Superior de Ingenieros Navales de Madrid (Spain); Carrillo, E. [Escuela Tecnica Superior de Ingenieros Navales de Madrid (Spain); Mellor, B.G. [University of Southampton (United Kingdom)

2006-12-15

428

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

SciTech Connect

The aim of the project is to develop a knowledge base to help the design of enhanced processes for mobilizing and extracting untrapped oil. We emphasize evaluation of novel surfactant mixtures and obtaining optimum combinations of the surfactants for efficient chemical flooding EOR processes. In this regard, an understanding of the aggregate shape, size and structure is crucial since these properties govern the crude oil removal efficiency. During the three-year period, the adsorption and aggregation behavior of sugar-based surfactants and their mixtures with other types of surfactants have been studied. Sugar-based surfactants are made from renewable resources, nontoxic and biodegradable. They are miscible with water and oil. These environmentally benign surfactants feature high surface activity, good salinity, calcium and temperature tolerance, and unique adsorption behavior. They possess the characteristics required for oil flooding surfactants and have the potential for replacing currently used surfactants in oil recovery. A novel analytical ultracentrifugation technique has been successfully employed for the first time, to characterize the aggregate species present in mixed micellar solution due to its powerful ability to separate particles based on their size and shape and monitor them simultaneously. Analytical ultracentrifugation offers an unprecedented opportunity to obtain important information on mixed micelles, structure-performance relationship for different surfactant aggregates in solution and their role in interfacial processes. Initial sedimentation velocity investigations were conducted using nonyl phenol ethoxylated decyl ether (NP-10) to choose the best analytical protocol, calculate the partial specific volume and obtain information on sedimentation coefficient, aggregation mass of micelles. Four softwares: OptimaTM XL-A/XL-I data analysis software, DCDT+, Svedberg and SEDFIT, were compared for the analysis of sedimentation velocity experimental data. The results have been compared to that from Light Scattering. Based on the tests, Svedberg and SEDFIT analysis were chosen for further studies.

P. Somasundaran

2004-11-20

429

Laser ablation at the solid-liquid interface: transient absorption of continuous spectral emission by ablated aluminium atoms  

NASA Astrophysics Data System (ADS)

A light emission from aluminium atoms produced by a pulsed laser irradiation to the aluminium metal-water interface was studied by emission spectra and analysed on the basis of a rate model. The time dependence of the emission spectra was obtained from the 20-80 ns time range. Early in this time range the Al (2P°-2S) transition appears as an absorption line in a continuous spectrum, suggesting that the optical thickness of the light-emitting region is considerably high and that aluminium atoms present in the light-emitting region are cold enough to absorb the continuous spectral emission. Later the emission surmounts the absorption, i.e. a positive emission peak over the continuous spectrum is observed. The time of the transition from the absorption regime to the emission regime depends on the irradiation laser fluence. These behaviours can be well described by the model calculation based on the kinetics of the two energy levels. By comparison between the model calculation and the experimental results, the time behaviour of the species in the light-emitting region is discussed.

Sakka, Tetsuo; Takatani, Kazuhiro; Ogata, Yukio H.; Mabuchi, Mahito

2002-01-01

430

Solid–liquid equilibrium and thermochemical studies of organic analogue of metal–nonmetal system: Succinonitrile–pentachloronitrobenzene  

Microsoft Academic Search

The phase diagram of an organic analogue of a metal–nonmetal system, involving succinonitrile–pentachloronitrobenzene, shows the formation of a eutectic and a monotectic. The two immiscible liquid phases are in equilibrium with a single liquid phase and the consolute temperature being 53.5°C above the monotectic horizontal. The phase equilibrium study confirms the alloy composition of monotectic and eutectic at 0.150 and

Shiva Kant; R. N. Rai

2011-01-01

431

Spectrophotometric determination of palladium after solid-liquid extraction with 1-(2-Pyridylazo)-2-naphthol at 90°C  

Microsoft Academic Search

An effective spectrophotometric determination of palladium with 1-(2-pyridylazo)-2-naphthol (PAN) using molten naphthalene as a diluent has been studied. A green complex of palladium with PAN is formed at 90°C. In the range of pH 1.5–7.5, the complex is quantitatively extracted into molten naphthalene. The organic phase is anhydrously dissolved in CHCl3 to be determined spectrophotometrically at 678 nm against the

Jinzhang Gao; Bo Peng; Haiyan Fan; Jingwan Kang; Xudong Wang

1997-01-01

432

Non-destructive monitoring of microbial biofilms at solid-liquid interfaces using on-line devices  

SciTech Connect

Corrosion, biofouling, and related problems have been an impetus for investigating interactions between microorganisms and solid surfaces. In recent years, a number of studies have been performed to assess the damages caused by microbial influenced corrosion (MIC). In a number of these studies, electrochemical techniques have monitored the performance of metal surfaces exposed to bacteria. However, most of these methods can only indirectly detect the presence of biofilms. In this paper, two non-destructive on-line monitoring devices, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FT/IR) and the quartz crystal microbalance (QCM) were used to directly monitor biofilm formation. These devices have been developed to study the initial fouling process and subsequent biofilm development and not merely the effects of the living film on the host material. The ATR-FT/IR technique provides information about biomass, exopolymer production, and the nutritional status of microbial biofilms. The QCM provides a direct measure of biomass. ATR-FT/IR and QCM detect 10{sup 6} and 10{sup 4} Caulobacter crescentus cells/cm{sup 2}, respectively. Both techniques can be coupled with electrochemical methods for deeper insight into mechanisms of MIC. 20 refs., 2 figs.

Nivens, D.E. (Tennessee Univ., Knoxville, TN (USA). Dept. of Chemistry Tennessee Univ., Knoxville, TN (USA). Inst. for Applied Microbiology); Chambers, J.Q. (Tennessee Univ., Knoxville, TN (USA). Dept. of Chemistry); White, D.C. (Tennessee Univ., Knoxville, TN (USA). Inst. for Applied Microbiology Tennessee Univ., Knoxville, TN (USA). Dept. of Microbiology Oak Ridge National Lab., TN (USA))

1990-01-01

433

EFFECTS OF DIFFERENTIAL SOLID-LIQUID REMOVAL RATES ON PROTOZOA NUMBERS IN CONTINUOUS CULTURES OF RUMEN CONTENTS  

Microsoft Academic Search

SUMMARY An apparatus for the continuous culture of rumen microorganisms is described, which has a dual effluent removal system designed to simu- late the differential flows for liquids and solids found in the rumen. In this apparatus a portion of the fermentation media is removed through a filter (primarily fluid), while mixed fluid and solid media flow out an overflow

W. H. Hoover; B. A. Crooker; C. J. Sniffen

434

Effect of oil droplets and their solid/liquid composition on the phase separation of protein-polysaccharide mixtures.  

PubMed

The phase separation of a model system consisting of sodium caseinate + xanthan ± a low fraction (up to 3 wt %) of an oil-in-water emulsion was studied at room temperature (20-25 °C). The composition of the oil phase was either 100 wt % n-tetradecane (TD); 50% TD + 50% eicosane (EC) or 100% EC. The droplets in these three "emulsions" were therefore totally liquid, partially solid, and totally solid, respectively. In the presence of 22 mM CaCl2, the mixed TD+EC droplets were most effective at inhibiting phase separation, while the EC emulsions could not prevent phase separation at all. At 32 mM CaCl2 the emulsions tended to promote phase separation, possibly due to enhanced calcium ion-induced droplet aggregation. The apparent interfacial viscosity (?i) between two macroscopically separated phases was also measured. In the presence of the semisolid mixed droplets ?i = 25 mN s m(-1), significantly higher than ?i with the pure (liquid) TD droplets (15 mN s m(-1)) or with the pure solid EC droplets (12 mN s m(-1)) or in the absence of droplets (<3 mN s m(-1)). Confocal microscopy showed that the microstructure of the phase separating regions also depended upon the composition of the oil droplets, and it is tentatively suggested that the more marked effects of the mixed emulsion droplets were due to them forming a stronger network at the interface via partial coalescence. Control of the extent of interfacial aggregation of droplets is therefore possibly one way to influence the course of phase separation in biopolymer mixtures. PMID:23805874

Hanazawa, Tomohito; Murray, Brent S

2013-07-24

435

Physical and chemical characterization and comparison of solids, liquids, and oils derived from Estonian and Green River formation shales  

SciTech Connect

Although only a single Estonian raw shale sample with an unknown history has been examined, physical and chemical characterization of this material has been accomplished. A comparison with a representative Green River formation raw shale has been made. Some of the findings are: (1) Elemental analysis indicates that the major elements, aluminum, magnesium, and sodium are deficient in Estonian shale compared to the Green River shale. The minor elements, barium and strontium, and the trace elements, arsenic, cobalt, rare earths, uranium, vanadium, and zinc are also deficient in the Estonian shale compared to the Green River shale. (2) Green River shales contain greater quantities of clay minerals (mainly illite) compared to the Estonian shale. (3) X-ray diffraction data suggests that ..cap alpha..-quartz concentration in the Estonian material is two to three times less than in typical Green River shales. (4) The suite of minerals in the Estonian spent shale suggests extreme processing conditions. (5) Scanning electron microscopy-electron microprobe analysis results indicate the intimate contact of the minerals on the micron level in the Green River shales. Mineral grains in the Estonian shale are dispersed throughout the organic material. (6) Aqueous leaching experiments indicate lead mobility from the Estonian spent materials result in concentrations that are undesirably high. (7) Phenolic compoundsare the most concentrated organic species present in the aqueous Estonian leachates. By comparison, carboxylic acids are the most concentrated species in the Green River leachates. (8) The Estonian raw shale sample has a Fischer assay of 93 barrels per ton, and the Green River an assay of 26 barrels per ton. (9) Organic solvent extraction of the raw shales with 15 different solvents show that approximately 60% of the kerogen in the Green River shale is extractable and only 3.8% of the Estonian shale is extracted under the same conditions.

Peterson, E.J.; Spall, W.D.

1981-01-01

436

Development of High-Resolution Imaging of Solid-Liquid Interface by Frequency Modulation Atomic Force Microscopy  

NASA Astrophysics Data System (ADS)

The high-resolution imaging technique used in liquid environments involving dynamic mode atomic force microscopy (AFM) with a frequency modulation (FM) detection technique has been newly developed on the basis of a commercial atomic force microscopy (AFM) apparatus, which is, generally, extremely difficult because of the large decrease in Q-factor caused by hydrodynamic damping in liquids. Through various improvements and optimization, the noise density of the improved deflection sensor was 29 fm/\\sqrt{Hz} (f0 = 141 kHz) in liquid. In addition, the noise level and bandwidth of the FM detector were improved to 6 mHz/\\sqrt{Hz} and 6 kHz, respectively. Thermal drift was successfully regulated at less than 1 nm/min in air for a sufficiently long time without any special air conditioning treatments. As a result, we succeeded in obtaining high-resolution images of polypropylene sheet, Au thin film, and DNA structures in a buffer solution. Therefore, liquid environments are proved to be suitable for high-resolution imaging by FM-AFM under ultrahigh vacuum (UHV) condition.

Suzuki, Katsuyuki; Kitamura, Shin-ichi; Tanaka, Shukichi; Kobayashi, Kei; Yamada, Hirofumi

2010-08-01

437

SOLID-LIQUID AND LIQUID-LIQUID EQUILIBRIA OF THE TERNARY SYSTEM URANIUM HEXAFLUORIDE-CHLORINE TRIFLUORIDE-HYDROGEN FLUORIDE  

Microsoft Academic Search

S>The complete condensed phase diagram of the ternary system UFâ --; ClFâ --HF has been determined. The measurements cover all possible ; compositions and temperature ranging from about --100 to + 100 . The ternary ; eutectic temperature is --90 at a composition of 0.0 to 0.2 formula % UF\\/sub ; 6\\/, 19.5 formula % ClFâ, and 80.5 formula %

G. P. Rutledge; W. Jr. Davis

1959-01-01

438

Resonant frequency and dissipation factor isotherms of adsorbed molecules on solid-liquid interfaces probed by quartz crystal microbalance  

NASA Astrophysics Data System (ADS)

Changes in the resonant frequency ?f and the dissipation factor ?D of a quartz crystal microbalance due to adsorption of molecules onto the electrode surface in solutions at different concentrations have been numerically analyzed. It has been found that the contribution from the solution due to the variation of the concentration can mask the overall behaviors of the ?f and ?D isotherms. However, if the solution is sufficiently dilute or the contribution of the solution can be characterized accurately, the corrected ?f and ?D , as a function of the solution concentration, will reveal characteristic features of the adsorption processes for the adsorbed films. Specifically, steplike behaviors will be displayed in ?f isotherms, which correspond to layer formation and layer-by-layer growth of the films, but the onsets of the steps usually do not coincide with the layer completion. Oscillatory behaviors will be revealed in ?D isotherms if the adsorbed molecular layer is soft at low concentration and becomes rigid near layer completion.

Fang, Jiajie; Zhu, Da-Ming

2008-09-01

439

Solid-Liquid and Solid-Solid Transformations in the Rare-Earth Metals at High Pressures  

Microsoft Academic Search

The fusion behavior and solid-solid transformations in the rare-earth metals have been investigated at pressures in the range 6-65 kbar. The phase diagrams are presented for La, Pr, Nd, Sm, Gd, and Tb. The initial melting slopes of Dy to Lu have been obtained. Since most of the rare-earth (R.E.) metals melt from a bcc structure, they offer a series

A. Jayaraman

1965-01-01

440

Effects of solid–liquid separation on recovering residual methane and nitrogen from digested dairy cow manure  

Microsoft Academic Search

The feasibility of optimizing methane and nitrogen recovery of samples obtained from farm biogas digester (35°C) and post-storage tank (where digested material is stored for 9–12months) was studied by separating the materials into different fractions using 2, 1, 0.5 and 0.25mm sieves. Mass-balances revealed that digested material mainly consists of <0.25mm (60–69%) and >2mm (18–27%) fractions, while fractions between 2

P. L. N. Kaparaju; J. A. Rintala

2008-01-01

441

Multiscale Phenomena in the Solid-Liquid Transition State of a Granular Material: Analysis and Modelling of Dense Granular Materials.  

National Technical Information Service (NTIS)

We have recently established, in close collaboration with experimentalists (from geology, physics, geotechnical and agricultural engineering), a comprehensive first-of-a-kind knowledge base for state-of-the- art data, characterization and modelling of the...

A. Tordesillas

2011-01-01

442

Essential Science for Teachers: Physical Science: Session 2. The Particle Nature of Matter: Solids, Liquids, and Gases  

NSDL National Science Digital Library

The segment provides examples of questions used to probe the student's ideas about particles, particularly, that substances such as air are made up of invisible tiny particles called atoms that are far too small to be seen through a regular microscope. When asked if he could draw air, the student responds that air cannot be drawn because it is just a bunch of invisible particles called atoms, but when probed further, the student replies that you could draw it as a bunch of dots.

Astrophysics, Harvard-Smithsonian C.