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1

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

2

Solid-liquid silicate equilibrium at HP/HT: Application to a crystallizing magma ocean  

NASA Astrophysics Data System (ADS)

The nature of mantle phases both at solidus and at liquidus represents a key part in the understanding of the dynamics of the deep mantle. At the end of Earth's accretion and after the core-mantle segregation, the possibility of a basal magma ocean at the top of the CMB depends on the physical properties of materials at relevant pressure and temperature. Seismic observations such as ultralow-velocity zones (ULVZs) and large low-shear velocity provinces (LLSVPs) raise the question of the existence of partially molten regions in the present mantle. We built a solid-liquid thermodynamic data base of silicates in the MgO-FeO-SiO2 system from the available experimental and computational data. We compute self-consistent phase equilibria in this system and show that our model is in good agreement with melting experiments and partionning coefficient measurements. We predicts both the inversion of the solid phase at incipient crystallization (ferro-periclase below 28 GPa, perovskite after) and the inversion of the liquid/solid density contrast with depth. Based on this thermodynamic approach, we discuss our preliminary results on the geodynamical evolution of the Earth magma ocean by computing the sequence of crystallization of this magma and the associated segregation dynamics.

Boukaré, Charles-Edouard; Ricard, Yanick; Matas, Jan

2014-05-01

3

Magnetically Enhanced Solid-Liquid Separation  

NASA Astrophysics Data System (ADS)

DuPont is developing an entirely new method of solid-liquid filtration involving the use of magnetic fields and magnetic field gradients. The new hybrid process, entitled Magnetically Enhanced Solid-Liquid Separation (MESLS), is designed to improve the de-watering kinetics and reduce the residual moisture content of solid particulates mechanically separated from liquid slurries. Gravitation, pressure, temperature, centrifugation, and fluid dynamics have dictated traditional solid-liquid separation for the past 50 years. The introduction of an external field (i.e. the magnetic field) offers the promise to manipulate particle behavior in an entirely new manner, which leads to increased process efficiency. Traditional solid-liquid separation typically consists of two primary steps. The first is a mechanical step in which the solid particulate is separated from the liquid using e.g. gas pressure through a filter membrane, centrifugation, etc. The second step is a thermal drying process, which is required due to imperfect mechanical separation. The thermal drying process is over 100-200 times less energy efficient than the mechanical step. Since enormous volumes of materials are processed each year, more efficient mechanical solid-liquid separations can be leveraged into dramatic reductions in overall energy consumption by reducing downstream drying requirements have a tremendous impact on energy consumption. Using DuPont's MESLS process, initial test results showed four very important effects of the magnetic field on the solid-liquid filtration process: 1) reduction of the time to reach gas breakthrough, 2) less loss of solid into the filtrate, 3) reduction of the (solids) residual moisture content, and 4) acceleration of the de-watering kinetics. These test results and their potential impact on future commercial solid-liquid filtration is discussed. New applications can be found in mining, chemical and bioprocesses.

Rey, C. M.; Keller, K.; Fuchs, B.

2005-07-01

4

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

SciTech Connect

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

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

2014-04-28

5

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

6

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

E-print Network

GENERAL RESEARCH A Generalized Method for the Solid-Liquid Equilibrium Stage and Its Application solutions, a generalized method is proposed in this paper for predicting the solid-liquid equilibrium stage these phases (named the solid-liquid equilibrium stage). Moreover, the applied method should be generalized

Zhang, Luzheng

7

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

E-print Network

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

Paris-Sud XI, Université de

8

Solid-Liquid Interfacial Premelting  

E-print Network

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

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

2013-02-28

9

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

USGS Publications Warehouse

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

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

1993-01-01

10

Magnetically Enhanced Solid-Liquid Separation  

Microsoft Academic Search

DuPont is developing an entirely new method of solid-liquid filtration involving the use of magnetic fields and magnetic field gradients. The new hybrid process, entitled Magnetically Enhanced Solid-Liquid Separation (MESLS), is designed to improve the de-watering kinetics and reduce the residual moisture content of solid particulates mechanically separated from liquid slurries. Gravitation, pressure, temperature, centrifugation, and fluid dynamics have dictated

C. M. Rey; K. Keller; B. Fuchs

2005-01-01

11

Novel optical PVC probes for on-site detection/determination of fluoroquinolones in a solid/liquid interface: application to the determination of Norfloxacin in aquaculture water.  

PubMed

A novel optical disposable probe for screening fluoroquinolones in fish farming waters is presented, having Norfloxacin (NFX) as target compound. The colorimetric reaction takes place in the solid/liquid interface consisting of a plasticized PVC layer carrying the colorimetric reagent and the sample solution. NFX solutions dropped on top of this solid-sensory surface provided a colour change from light yellow to dark orange. Several metals were tested as colorimetric reagents and Fe(III) was selected. The main parameters affecting the obtained colour were assessed and optimised in both liquid and solid phases. The corresponding studies were conducted by visible spectrophotometry and digital image acquisition. The three coordinates of the HSL model system of the collected image (Hue, Saturation and Lightness) were obtained by simple image management (enabled in any computer). The analytical response of the optimised solid-state optical probe against concentration was tested for several mathematical transformations of the colour coordinates. Linear behaviour was observed for logarithm NFX concentration against Hue+Lightness. Under this condition, the sensor exhibited a limit of detection below 50 ?M (corresponding to about 16 mg/mL). Visual inspection also enabled semi-quantitative information. The selectivity was ensured against drugs from other chemical groups than fluoroquinolones. Finally, similar procedure was used to prepare an array of sensors for NFX, consisting on different metal species. Cu(II), Mn(II) and aluminon were selected for this purpose. The sensor array was used to detect NFX in aquaculture water, without any prior sample manipulation. PMID:22560163

Silva, Tâmara I B; Moreira, Felismina T C; Truta, Liliana A A N A; Sales, M Goreti F

2012-01-01

12

Ultrasonic Spectroscopy of Solid-Liquid Suspensions.  

NASA Astrophysics Data System (ADS)

There is a great deal of interest in techniques which characterize solid-liquid suspensions through measurements of ultrasonic properties such as phase velocity and attenuation. In this study, a reliable ultrasonic spectroscopy methodology has been developed that is capable of handling commonly encountered solid-liquid suspensions at high particle concentrations, over a wide frequency range. Performance of the system has been validated using laboratory measurements of attenuation spectra of a reference liquid (Dow Corning 710 silicone fluid). Ultrasonic spectroscopy measurements of colloidal dispersions are obtained over a wide frequency range of 1-100 MHz using linear regression, with loss data for many pathlengths, and solids concentration varying from 3 to 43 volume percent. The current sensor provides reliable values of attenuation coefficients ranging from 0.1 to 2500 dB/cm. Quantitative comparison of experimental data on attenuation coefficients with corresponding predictions based on theoretical modeling that accounts for attenuation dependence on particle size distribution and particle volume fraction, over the wide range of operating frequencies is presented. The theoretical model is able to predict the experimentally observed complex functionality of frequency and concentration dependence of attenuation coefficients fairly well. Some new features of the data were observed when both, the sound speed and the attenuation coefficient spectra, were presented together on a complex plane through the complex wave number. An equivalent acoustophoretic diameter has been proposed which provides a convenient way of representing particle size distribution by means of a single parameter, which is associated with the two parameters (mass geometric mean and geometric standard deviation) of the log-normal distribution. Also, interpretation of sound speed has been made in terms of solids concentration estimation. During field tests at a manufacturing plant, the on-line sensor prototype has provided attenuation spectra, and corresponding particle size distribution estimates under processing conditions showing excellent reproducibility and robust operation. The tests of predictive model and on-line sensor prototype operation show that ultrasonic spectroscopy of concentrated colloids is a promising tool for on-line characterization of industrial slurries, and offers the possibility of its use in quality control and process control applications.

Sharma, Arvind

13

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

PubMed

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

Warshavsky, Vadim B; Song, Xueyu

2012-09-01

14

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

NASA Astrophysics Data System (ADS)

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

Warshavsky, Vadim B.; Song, Xueyu

2012-09-01

15

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

SciTech Connect

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

Warshavsky, Vadim B.; Song, Xueyu

2012-09-18

16

Journe de perfectionnement aux applications de l'acupuncture en obsttrique  

E-print Network

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

Brest, Université de

17

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

E-print Network

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

Brest, Université de

18

Systems and methods for monitoring a solid-liquid interface  

DOEpatents

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

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

2013-06-11

19

Photoinduced crystal-to-liquid phase transitions of azobenzene derivatives and their application in photolithography processes through a solid-liquid patterning.  

PubMed

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

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

2014-10-01

20

Ginzburg-Landau theory for the solid-liquid interface of bcc elements. II - Application to the classical one-component plasma, the Wigner crystal, and He-4  

NASA Technical Reports Server (NTRS)

The previously developed Ginzburg-Landau theory for calculating the crystal-melt interfacial tension of bcc elements to treat the classical one-component plasma (OCP), the charged fermion system, and the Bose crystal. For the OCP, a direct application of the theory of Shih et al. (1987) yields for the surface tension 0.0012(Z-squared e-squared/a-cubed), where Ze is the ionic charge and a is the radius of the ionic sphere. Bose crystal-melt interface is treated by a quantum extension of the classical density-functional theory, using the Feynman formalism to estimate the relevant correlation functions. The theory is applied to the metastable He-4 solid-superfluid interface at T = 0, with a resulting surface tension of 0.085 erg/sq cm, in reasonable agreement with the value extrapolated from the measured surface tension of the bcc solid in the range 1.46-1.76 K. These results suggest that the density-functional approach is a satisfactory mean-field theory for estimating the equilibrium properties of liquid-solid interfaces, given knowledge of the uniform phases.

Zeng, X. C.; Stroud, D.

1989-01-01

21

COMPLEMENTS SUR LES SOUS-TORES D'UN PRESCHEMA EN GROUPES. APPLICATION AUX  

E-print Network

sous-sch´ema ferm´e de S d´efini par un id´eal de carr´e nul, G un S-pr´esch´ema en groupes, H0 un sous´ema de S d´efini par un faisceau d'id´eaux localement nilpotent, G un S-pr´esch´ema en groupes, plat etEXPOS´E XV COMPL´EMENTS SUR LES SOUS-TORES D'UN PR´ESCH´EMA EN GROUPES. APPLICATION AUX GROUPES

Stein, William

22

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

NASA Astrophysics Data System (ADS)

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

Asadi, Ebrahim; Asle Zaeem, Mohsen

2015-01-01

23

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

NASA Astrophysics Data System (ADS)

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

Huang, Rongzong; Wu, Huiying

2014-11-01

24

Solid liquid interfacial energy of dichlorobenzene  

NASA Astrophysics Data System (ADS)

Commercial-purity dichlorobenzene was purified using a columnar distillation system. The equilibrated grain boundary groove shapes for purified dichlorobenzene (DCB) were directly observed by using a temperature gradient stage. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficient and solid-liquid interfacial energy of purified DCB were determined to be (6.2 ± 0.6) × 10-8 K m and (29.3 ± 4.4) × 10-3 J m-2 with the present numerical model and the Gibbs-Thomson equation, respectively. The grain boundary energy of the DCB phase was determined to be (54.1 ± 9.2) × 10-3 J m-2 from the observed grain boundary grooves. The thermal conductivity ratio of the liquid phase to the solid phase was measured to be 0.94.

Böyük, U.; Keslioglu, K.; Marasli, N.

2007-03-01

25

X-rays at Solid-Liquid Surfaces  

SciTech Connect

Solid-liquid interfaces play an important role in many areas of current and future technologies, and in our biosphere. They play a key role in the development of nanofluidics and nanotribology, which sensitively depend on our knowledge of the microscopic structures and phenomena at the solid-liquid interface. The detailed understanding of how a fluid meets a wall is also a theoretical challenge. In particular, the phenomena at repulsive walls are of interest, since they affect many different phenomena, such as water-repellent surfaces or the role of the hydrophobic interaction in protein folding. Recent x-ray reflectivity studies of various solid-liquid interfaces have disclosed rather intriguiing phenomena, which will be discussed in this lecture: premelting of ice in contact with silica; liquid Pb in contact with Si; water in contact with hydrophobic surfaces. These experiments, carried out with high-energy x-ray microbeams, reveal detailed insight into the liquid density profile closest to the wall. A detailed insight into atomistic phenomena at solid-liquid interfaces is also a prerequisite in the microscopic control of electrochemical reactions at interfaces. Recent x-ray studies show the enormous future potential of such non-destructive analytical tools for the in situ observation of (electro-)chemical surface reactions. This lecture will review recent x-ray experiments on solid-liquid interfaces.

Dosch, Helmut (Max Planck Institute for Metals Research) [Max Planck Institute for Metals Research

2007-05-02

26

Théorie du producteur en présence de rationnements : application aux quotas laitiers en Europe  

Microsoft Academic Search

[eng] This paper develops a model to analyze the producer behavior under rationing from the behavior without constraint. This model is applied to milk quotas in EEC. [fre] Le comportement d'offre en présence de rationnements est décrit sur la base du comportement sans contrainte. Ce modèle est appliqué aux quotas laitiers en Europe.

Louis P. Mahe; Hervé Guyomard

1990-01-01

27

Trends in solids/liquids poisoning suicide rates in Taiwan: a test of the substitution hypothesis  

PubMed Central

Background Several previous studies have illustrated that restricting access to lethal methods can reduce suicide rates. The most often cited example was Kreitman's study, showing a reduction not only in gas-specific suicide rates, but also in the overall suicide rates because of the lack of increase of other methods. However, method substitution is still a major concern in the application of the means restriction strategy to prevent suicide. The aim of the study was to investigate whether the reduction in the solids/liquids poisoning suicide rate in 1983-1993 after the launching of pesticide restriction interventions in Taiwan was accompanied with an increase in the suicide rate using other methods (method substitution). Methods Data on age-, sex- and method-specific suicide rates for 1971-1993 in Taiwan were obtained. Changes in solids/liquids poisoning suicide rates were compared with suicide rates by hanging and other methods between 1983 and 1993. Results No concomitant increase in suicide rates by hanging or other methods was noted from 1983 to 1993, during which the suicide rates by poisoning with solids/liquids (mainly pesticides) decreased markedly and steadily. The phenomenon of method substitution was also not found by sex and age groups. Conclusion In general, no method substitution was found along with the reduction in solids/liquids suicide rates in Taiwan. Our study results have also added the evidence that restricting access to methods maybe a promising strategy in preventing suicide, particularly in those countries where the "target method" has been found to contribute greatly to the suicide rates. PMID:21933432

2011-01-01

28

Perturbation theory for solid-liquid interfacial free energies.  

PubMed

A perturbation theory is developed to calculate solid-liquid interfacial free energies, including anisotropy. The method is applied to systems with inverse-power and Lennard-Jones pair potentials as well as to metal systems with embedded-atom model potentials. The results are in reasonable agreement with the corresponding ones obtained from molecular dynamics simulations. PMID:21386528

Warshavsky, Vadim B; Song, Xueyu

2010-09-15

29

Solid - liquid phase diagram for ethylene glycol + water  

Microsoft Academic Search

Freezing point data for the system (ethylene glycol + water) were measured independently by two different laboratories. Measurements were made over the entire composition range with particular emphasis on mixtures containing from 55 to 85 weight percent ethylene glycol. Using time vs. temperature cooling and warming curves, the solid-liquid phase diagram of ethylene glycol and water mixtures was determined. The

Dennis R. Cordray; Lisa R. Kaplan; Peter M. Woyciesjes; Theodore F. Kozak

1996-01-01

30

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

31

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

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

32

Calculation of solid-liquid interfacial free energy of Cu by two different methods  

NASA Astrophysics Data System (ADS)

Both the solid-liquid interfacial free energy and Turnbull coefficient calculated by the capillary fluctuation method (CFM) are consistent with those by the critical nucleus method (CNM). The calculated solid-liquid interfacial free energy by CNM is more accurate than that by CFM, but CFM can give the anisotropy parameter of solid-liquid interfacial free energy while CNM can not. Thus, these two methods can be combined to calculate the solid-liquid interfacial free energy and its anisotropy.

Zhou, Huaguang; Lin, Xin; Wang, Meng; Huang, Weidong

2013-08-01

33

Final Report: Thermal Conductance of Solid-Liquid Interfaces  

Microsoft Academic Search

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. ;\\u000a;\\u000a 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

David Cahil; Paul Braun

2006-01-01

34

Solid-Liquid Separation of Animal Manure and Wastewater  

E-print Network

high initial costs, maintenance and energy requirements. ? Coagulation Flocculation. A relatively new tech- nique for solid-liquid separation uses chemicals to aggregate suspended solids (coagulation) to form settleable particles and to convert... of mechanical separators include screen separators, centrifuges, hydrocyclones and presses (screw or belt type). Screen separators The separators are further classified as stationary, rotating and vibrating screens. Stationary inclined screen: These so...

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

1999-10-19

35

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

36

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

37

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

USGS Publications Warehouse

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

Udegbunam, E.; Amaefule, J.O.

1998-01-01

38

Élaboration de couches minces de carbone par ablation laser femtoseconde pour application aux biomatériaux implantables  

NASA Astrophysics Data System (ADS)

Des films de tetrahedral amorphous-Carbon (ta-C) ont été déposés, sous vide poussé, par ablation d'une cible de graphite avec un laser Ti : saphir (durée d'impulsion 170 fs, fréquence de répétition 1 kHz, énergie maximale par impulsion 1,5 mJ, longueur d'onde 800 nm) sur substrats standard et sur biomatériaux (acier AISI 316L, polyéthylène à très haut poids moléculaire). Les propriétés de ces couches (structure, propriétés nanomécaniques et tribologiques) ont été caractérisées, en fonction des conditions d'élaboration, en examinant l'intérêt de l'utilisation d'un laser femtoseconde et leur capacité à satisfaire aux exigences spécifiques du domaine biomédical. Les propriétés d'adhérence des films ont été considérablement améliorées lors du dépôt sur des substrats en acier inoxydable préalablement préparés par décapage ionique in situ sous atmosphère d'argon. La surface hémisphérique d'une tête fémorale, en acier inoxydable, de prothèse de hanche de diamètre 22,2 mm a été revêtue d'un film de DLC adhérent et homogène en épaisseur. La résistance à l'usure de ce revêtement sera quantifiée à l'aide d'un simulateur de marche durant un million de cycles (correspondant à une année d'activité physique d'un être humain).

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

2005-06-01

39

Solid/liquid interfacial free energies in binary systems  

NASA Technical Reports Server (NTRS)

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

Nason, D.; Tiller, W. A.

1973-01-01

40

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

NASA Astrophysics Data System (ADS)

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

Ciesielski, Artur; El Garah, Mohamed; Haar, Sébastien; Kova?í?ek, Petr; Lehn, Jean-Marie; Samorì, Paolo

2014-11-01

41

Interaction of Porosity with a Planar Solid/Liquid Interface  

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

42

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

43

Interaction of Porosity with a Planar Solid/Liquid Interface  

NASA Technical Reports Server (NTRS)

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

Catalina, Adrian V.; Stefanescu, Doru M.; Sen, Subhayu; Kaukler, William F.

2004-01-01

44

Solubility measurement apparatus for rapid determination of solid-liquid equilibrium behavior.  

E-print Network

??The synthesis of crystallization-based separation processes requires experimental solid-liquid equilibrium (SLE) behavior of the system under consideration, effective representation of such SLE data, selection of… (more)

Chan, Yik Chung

2008-01-01

45

Quasi-two-dimensional equilibrium solid/liquid interface of colloids at low osmotic pressure  

NASA Astrophysics Data System (ADS)

Solid/liquid interface is very essential for nucleation and the crystal growth process. In the present paper, we present a new method to prepare the crystal-fluid interface of colloidal hard spheres by evaporation in microchannel, which is a good candidate as a model system for the investigation of solid/liquid interface. In the system, the quasi-equilibrium colloidal solid/liquid interface is obtained at low osmotic pressure controllable by evaporation. The results show a dynamical broadening amorphous region near the solid/liquid interface. The crystal growth process in the dynamical broadening region depends on the competition between the attaching kinetics and the supersaturation related to the volume fraction. The results agree with previous investigations.

Wang, Zhijun; Wang, Jincheng; Wang, Lilin; Li, Junjie; Zhou, Yaohe

2014-01-01

46

Solid\\/liquid separation performance of hydrocyclones with different cone combinations  

Microsoft Academic Search

Hydrocyclones used for solid–liquid separation are usually composed of a single cone. In this paper, we designed hydrocyclones with two cone combinations for solid–liquid separation and studied the flow field and separation performance. Simulation and experimental results showed that when the second cone remained unchanged, the angle change of the first cone had significant effect on the value of three-dimensional

Qiang Yang; Hua-lin Wang; Yi Liu; Zhi-ming Li

2010-01-01

47

Modeling the solid-liquid phase transition in saturated triglycerides  

NASA Astrophysics Data System (ADS)

We investigated theoretically two competing published scenarios for the melting transition of the triglyceride trilaurin (TL): those of (1) Corkery et al. [Langmuir 23, 7241 (2007)], in which the average state of each TL molecule in the liquid phase is a discotic "Y" conformer whose three chains are dynamically twisted, with an average angle of ˜120° between them, and those of (2) Cebula et al. [J. Am. Oil Chem. Soc. 69, 130 (1992)], in which the liquid-state conformation of the TL molecule in the liquid phase is a nematic h?-conformer whose three chains are in a modified "chair" conformation. We developed two competing models for the two scenarios, in which TL molecules are in a nematic compact-chair (or "h") conformation, with extended, possibly all-trans, chains at low-temperatures, and in either a Y conformation or an h? conformation in the liquid state at temperatures higher than the phase-transition temperature, T?=319 K. We defined an h-Y model as a realization of the proposal of Corkery et al. [Langmuir 23, 7241 (2007)], and explored its predictions by mapping it onto an Ising model in a temperature-dependent field, performing a mean-field approximation, and calculating the transition enthalpy ?H. We found that the most plausible realization of the h-Y model, as applied to the solid-liquid phase transition in TL, and likely to all saturated triglycerides, gave a value of ?H in reasonable agreement with the experiment. We then defined an alternative h-h? model as a realization of the proposal of Cebula et al. [J. Am. Oil Chem. Soc. 69, 130 (1992)], in which the liquid phase exhibits an average symmetry breaking similar to an h conformation, but with twisted chains, to see whether it could describe the TL phase transition. The h-h? model gave a value of ?H that was too small by a factor of ˜3-4. We also predicted the temperature dependence of the 1132 cm-1 Raman band for both models, and performed measurements of the ratios of three TL Raman bands in the temperature range of -20 °C?T ?90 °C. The experimental results were in accord with the predictions of the h-Y model and support the proposal of Corkery et al. [Langmuir 23, 7241 (2007)] that the liquid state is made up of molecules that are each, on average, in a Y conformation. Finally, we carried out computer simulations of minimal-model TLs in the liquid phase, and concluded that although the individual TL molecules are, on average, Y conformers, long-range discotic order is unlikely to exist.

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

2010-02-01

48

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

49

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

PubMed

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

Ciesielski, Artur; El Garah, Mohamed; Haar, Sébastien; Kova?í?ek, Petr; Lehn, Jean-Marie; Samorì, Paolo

2014-11-01

50

Characterization of Solid Liquid Suspensions Utilizing Non-Invasive Ultrasonic Measurements  

SciTech Connect

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

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

2004-03-31

51

Effects of Ultrasound on Behavior of Fine Solid Particles in a Solid-Liquid Mixture  

Microsoft Academic Search

In a solid-liquid two-phase flow, the separation of particles or a reduction of particle concentration is often desired. Utilization of ultrasound has been considered as one technique for the separation of particles. Particles are known to aggregate due to the radiation pressure of ultrasound. However, the effect of ultrasound including cavitation on particle behavior is not well understood. Thus, we

Junichi Ohta; Takashi Makara; Seisuke Hirobe

2007-01-01

52

On a phase field model for solid-liquid phase transitions  

E-print Network

solidification) or for liquid-vapor mix- tures (e.g. boiling water), but also for elastic materials subject distinct phases. This is the case for solid-liquid mix- tures (e.g. ice-water or alloys during telling how much the interface temperature differs from the equilibrium temperature when the interface

53

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

54

Finite difference computation of solid\\/liquid phase change energy transport - Comparison with experimental data  

Microsoft Academic Search

A computational model is presented for the prediction of solid\\/liquid phase change energy transport including the influence of free convection and comparisons made with experimental data for which the phase change material is heated from the side and from below. The computational model considers the velocity components of all nonliquid PCM control volumes to be zero but fully solves the

G. E. Schneider

1986-01-01

55

ABATEMENT OF AMMONIA EMISSIONS FROM SWINE LAGOONS USING POLYMER-ENHANCED SOLID-LIQUID SEPARATION  

Microsoft Academic Search

A study was conducted to determine the effects of solid-liquid separation of liquid swine manure on ammonia emissions from lagoons. This determination was done at full-scale in two contiguous swine production units that had similar animal production management. One of these units was maintained as a control using the anaerobic lagoon treatment method. In the second production unit, solids were

A. A. Szögi; M. B. Vanotti

56

Gleeble Testing to Assess Solid\\/Liquid Metal Embrittlement of Gun Steels by Copper  

Microsoft Academic Search

Gleeble testing was performed to assess the solid\\/liquid metal embrittlement of gun steels by copper. An interior ballistics and finite element model provided the maximum bore temperatures in a 155 mm gun after aggressive firing. Specimens were manufactured out of three different steels. Testing was performed on bare steel as well as copper plated specimens at temperatures ranging from 868°C to

G. N. Vigilante; S. Bartolucci; J. Izzo; M. Witherell; S. B. Smith

2012-01-01

57

Solid-liquid phase coexistence and structural transitions in palladium clusters  

Microsoft Academic Search

We use molecular dynamics with an embedded atom potential to study the behavior of palladium nanoclusters near the melting point in the microcanonical ensemble. We see transitions from both fcc and decahedral ground-state structures to icosahedral structures prior to melting over a range of cluster sizes. In all cases this transition occurs during solid-liquid phase coexistence and the mechanism for

D. Schebarchov; S. C. Hendy

2006-01-01

58

Selective Solid-Liquid Extraction of Lithium Halide Salts Using a Ditopic Macrobicyclic Receptor  

E-print Network

Selective Solid-Liquid Extraction of Lithium Halide Salts Using a Ditopic Macrobicyclic Receptor industrial topic.1 Of particular interest is the selective extraction of lithium salts, with potential receptors that have a high and selective affinity for lithium cations.3 In terms of liquid extraction

Smith, Bradley D.

59

The roots of the Stoneley wave equation for solid-liquid interfaces  

Microsoft Academic Search

The Stoneley wave equation arises in the study of waves on interfaces between either two solid media or solid and liquid media. The roots of the equation are related, through the appropriate analysis, to the nature and velocity of the interface waves. In this paper, the eight roots of the Stoneley wave equation for solid-liquid interfaces are investigated analytically for

James H. Ansell

1972-01-01

60

Thermal conductance of solid-liquid interfaces Scott Huxtable, Zhenbin Ge, David G. Cahill  

E-print Network

Thermal conductance of solid-liquid interfaces Scott Huxtable, Zhenbin Ge, David G. Cahill thermal conductivity in nanostructured materials ­ improved thermoelectric energy conversion improved thermal barriers­ improved thermal barriers · High thermal conductivity 50 nm · High thermal conductivity

Braun, Paul

61

Occurrence and solid-liquid partition of sulfonated naphthalene-formaldehyde condensates in the aquatic environment.  

PubMed

Sulfonated naphthalene-formaldehyde condensates (SNFC) are high production volume chemicals used in a variety of applications, for example, as concrete plasticizers, tanning agents, or dye dispersants. They enter the aquatic environment primarily by the wastewater path. The occurrence and fate of the monomers, which are different isomers of mono- and disulfonated naphthalene, was intensively investigated in previous studies. However, the environmental fate of the persistent higher molecular SNFC is so far widely unknown. This paper describes an ultrasonic extraction under alkaline conditions, followed by ion-pair HPLC with fluorescence detection for the analysis of SNFC oligomers from solid environmental matrixes such as sewage sludge, suspended solids, and river sediments. Limits of quantification of about 0.1 mg kg-1 d.m. were well below the measured concentrations in environmental samples. SNFC were adsorbed to suspended solids and river sediments in three major German rivers (Rhine, Neckar, and Danube) in concentrations typically up to several mg kg(-1) d.m. A total content of about 4 g kg(-1) d.m. was measured in a sewage sludge of a municipal wastewater treatment plant, which receives wastewater from a textile dyeing plant. Furthermore, the first quantitative field data on the partition of SNFC and their monomers between the aqueous phase and solid environmental compartments are presented. Solid-liquid partition coefficients (Kd) of oligomers with a chain-length ranging from three to six naphthalenesulfonate units were derived from the analysis of corresponding wastewater and sewage sludge samples and from suspended solids and river water samples, respectively. Determined Kd values were in the range from 10(2) to 10(4) L kg(-1). PMID:15819205

Lange, Frank T; Merklinger, Michael; Wenz, Michael; Brauch, Heinz-J; Lehmann, Markus; Pinter, Istvan

2005-03-15

62

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

NASA Technical Reports Server (NTRS)

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

Wang, Jai-Ching

1994-01-01

63

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

64

Flowing Foam: T1 events and solid-liquid transitions.  

NASA Astrophysics Data System (ADS)

Flowing aqueous foam is found in many applications ranging from oil recovery, to fire fighting, to spreading shaving cream. Aqueous foam consists of gas bubbles with liquid walls. One of the striking features of foam is that despite being composed entirely of fluids, its mechanical properties are either those of a solid (elastic response) or fluid (viscous flow), depending on the nature of the applied stress and strains. We study the transition between these two regimes using a model foam system: bubble rafts. Bubble rafts are a single layer of bubbles floating on the air-water surface. This allows us to track the motion of all the bubbles during flow. In this talk, we will present two main results. First, we will discuss the observation of the coexistence between a solid-like and fluid-like state during flow. Second, we will discuss the role played by nonlinear, topological rearrangements, known as T1 events, in determining the mechanical response of the system.

Dennin, Michael

2005-11-01

65

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

66

Computation of heat transfer with solid\\/liquid phase change including free convection  

Microsoft Academic Search

A computational model is presented for the prediction of solid\\/liquid phase change energy transport including the influence of free convection. The computational model considers the velocity components of all nonliquid PCM control volumes to be zero but fully solves the coupled mass-momentum problem within the liquid. The thermal energy model includes the entire domain and employs an enthalpy-like model in

G. E. Schneider

1985-01-01

67

Interaction of Porosity with an Advancing Solid/Liquid Interface: a Real-Time Investigation  

NASA Technical Reports Server (NTRS)

Problems associated with formation of porosity during solidification continue to have a daily impact on the metal forming industry. Several past investigations have dealt with the nucleation and growth aspects of porosity. However, investigations related to the interaction of porosity with that of a solidification front has been limited mostly to organic analogues. In this paper we report on real time experimental observations of such interactions in metal alloys. Using a state of the art X-Ray Transmission Microscope (XTM) we have been able to observe and record the dynamics of the interaction. This includes distortion of the solid/liquid interface near a poro.sity, solute segr,egation patterns surrounding a porosity and the change in shape of the porosity during interaction with an advancing solid/liquid interface. Results will be presented for different Al alloys and growth conditions. The experimental data will be compared to theory using a recently developed 2D numerical model. The model employs a finite difference approach where the solid/liquid interface is defined through the points at which the interface intersects the grid lines. The transport variables are calculated at these points and the motion of the solidification front is determined by the magnitude of the transport variables. The model accounts for the interplay of the thermal and solutal field and the influence of capilarity to predict the shape of the solid/liquid interface with time in the vicinity of porosity. One can further calculate the perturbation of the solutal field by the presence of porosity in the melt.

Sen, S.; Kaukler, W.; Catalina, A.; Stefanescu, D.; Curreri, P.

1999-01-01

68

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

69

Spin-polarized scanning tunneling microscopy at the solid/liquid interface  

NASA Astrophysics Data System (ADS)

We show strong indications for spin-polarized tunneling between a magnetic tip of a scanning tunneling microscope and a magnetic substrate at a solid/liquid interface under electrochemical conditions at room temperature. As a model system Co islands of several 100 nm in diameter were electrochemically grown on Au(111). They show a perpendicular easy axis of the magnetization for two and three atomic layers of Co.

Majer, C.; Schindler, W.

2015-01-01

70

Controlled growth of oriented amorphous silicon nanowires via a solid–liquid–solid (SLS) mechanism  

Microsoft Academic Search

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

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

2001-01-01

71

Solid–liquid–solid growth mechanism of single-wall carbon nanotubes  

Microsoft Academic Search

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

A Gorbunov; O Jost; W Pompe; A Graff

2002-01-01

72

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

73

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

SciTech Connect

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

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

2014-04-11

74

Computation of heat transfer with solid/liquid phase change including free convection  

NASA Astrophysics Data System (ADS)

A computational model is presented for the prediction of solid/liquid phase change energy transport including the influence of free convection. The computational model considers the velocity components of all nonliquid PCM control volumes to be zero but fully solves the coupled mass-momentum problem within the liquid. The thermal energy model includes the entire domain and employs an enthalpy-like model in addition to recent developments for handling the phase change interface nonlinearity. The predictions are compared with experimental data and with previous predictions for the test problem examined. The present procedure demonstrates both excellent agreement with the experimental data and a significant computational cost reduction from previous procedures.

Schneider, G. E.

1985-01-01

75

Measuring the Au(1 1 1) surface state at the solid liquid interface  

NASA Astrophysics Data System (ADS)

We present the first direct observation of an occupied noble metal surface state at the metal/liquid interface. The Au(1 1 1) Shockley-like surface state was measured by scanning tunneling spectroscopy (STS) at the Au(1 1 1)/ n-tetradecane interface. These results show that the surface state of gold survives in a liquid environment, and can be probed by STS. More generally it indicates that STS can be used to study electronic properties of surfaces at the solid/liquid interface, and that spectra can be directly compared to measurements and calculations of a surface's electronic structure in ultra-high vacuum.

Hulsken, B.; Gerritsen, J. W.; Speller, S.

2005-04-01

76

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

77

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

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

78

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

PubMed

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

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

2015-02-01

79

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

NASA Astrophysics Data System (ADS)

The use of pulse-echo ultrasonic flaw detectors to detect the presence and location of cracks, voids, and other discontinuities in metals and non-metal is well known. The solid-liquid interface in a melting or freezing metal can also be considered as a discontinuity, in that there is a measurable difference in both sound velocity and density across the interface. For normal incidence of longitudinal waves in a typical case, about 10% of the pressure amplitude of the incident wave would be expected to be reflected. Thus such a technique, if it worked, could be considered as a method for measurement, feedback, and closed-loop process control in such applications as continuous casting of metals. To examine the feasibility of this technique, the melting and freezing of 99.9 Sn has been studied at NBS using pulse-echo equipment at a nominal frequency of 5MHz. The transducer contacts the cold end of a 5/16? × 8? specimen in a graphite mold in a Bridgman gradient furnace (unidirectional melting/solidification). Sharp echoes easily locate the interface position, in both freezing and melting, to ±1 mm, over the range of interface velocities tested (up to˜4mm/min). A literature search showed that similar or related tests have been made by at least 5 other groups in the U. S. and abroad, in a number of materials and geometries. Most of them were also successful in locating the interface. In the relatively difficult case of steel, while interfaces could be located under certain conditions, there were also found some substantial problems involving signal attenuation and poor signal/noise ratios. Some possible causes for this could be poor reflection of the incident beam from the dendritic ?mushy zone? in the case of alloys, as well as bulk attenuation effects due to grain size or other scattering centers. In the case of continuous castings, the coupling of the acoustic energy into hot, rough and scaly surfaces presents additional problems. However, much progress has been made in recent years on the problems of getting acoustic energy into hot steel surfaces, including the use of noncontact Lorentz-force transducers (EMATS). NBS work is focussed o the study of the measurement factors inherent in possible use of the method for process control, as well as possible use for interface characterization. In those cases, such as steel continuous casting,where signal/noise problems may be limiting, appropriate signal processing techniques should make it possible to improve signal/noise ratios. The techniques include corrections for transducer response as well as signal averaging and correlation techniques. To do this, a sampling oscilloscope is used to provide a slowed but shape-preserving output of the received echo, which is then fed to a digitizer and then to a small computer (64 k memory, Z-80 CPU, 8? floppy discs).

Parker, R. L.

1982-05-01

80

Solid-liquid equilibria and triple points of n-6 Lennard-Jones fluids  

NASA Astrophysics Data System (ADS)

Molecular dynamics simulations are reported for the solid-liquid coexistence properties of n-6 Lennard-Jones fluids, where n =12, 11, 10, 9, 8, and 7. The complete phase behavior for these systems has been obtained by combining these data with vapor-liquid simulations. The influence of n on the solid-liquid coexistence region is compared using relative density difference and miscibility gap calculations. Analytical expressions for the coexistence pressure, liquid, and solid densities as a function of temperature have been determined, which accurately reproduce the molecular simulation data. The triple point temperature, pressure, and liquid and solid densities are estimated. The triple point temperature and pressure scale with respect to 1/n, resulting in simple linear relationships that can be used to determine the pressure and temperature for the limiting ?-6 Lennard-Jones potential. The simulation data are used to obtain parameters for the Raveché, Mountain, and Streett and Lindemann melting rules, which indicate that they are obeyed by the n-6 Lennard Jones potentials. In contrast, it is demonstrated that the Hansen-Verlet freezing rule is not valid for n-6 Lennard-Jones potentials.

Ahmed, Alauddin; Sadus, Richard J.

2009-11-01

81

The adsorption of polymerized rodlike micelles at the solid-liquid interface.  

PubMed

Solutions of rodlike polymeric micellar aggregates, formed from the polymerization of cetyltrimethyl-ammonium 4-vinylbenzoate (CTVB), adsorb at the solid-liquid interface. The poly-CTVB aggregates are imaged in situ using soft contact atomic force microscopy. The aggregates form self-organized two-dimensional films that show a high degree of order on nanometer to micrometer length scales. Unlike their simple surfactant analogues, the adsorbed layer structures are permanently adsorbed and the structure is resilient to washing with pure solvent. In the case of poly-CTVB, the adsorbed aggregates appear to be rigid cylindrical structures of between 30 and 60 nm in length. At the interface, the center to center spacing of the aligned aggregates is 8+/-1 nm. Images of a second series ofpolymerized aggregates formed by the copolymerization of CTVB with sodium vinyltosylate revealed a change in the aggregate structure to a set of linked spherical aggregates. These polymerized aggregates also spontaneously form a permanent adsorbed layer at the solid-liquid interface. PMID:15803681

Biggs, Simon; Kline, Steven R; Walker, Lynn M

2004-02-17

82

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

PubMed

The aim of this research was to study the recovery of phenolic compounds from grape seeds, by-products from winemaking industries, using ethanolic solid-liquid extraction. For such a purpose, the combined effects of the extraction time (9, 19 and 29?h) and the solid-liquid ratio (0.10, 0.20 and 0.30?gdw?mL(-1)), were investigated (where dw?=?dry waste). Results demonstrated that Pinot Noir seeds had high levels of both total polyphenols (73.66?mg(Gallic Acid Equivalent)?gdw(-1)) and flavonoids (30.90?mg(Catechin Equivalent)?gdw(-1)), being the optimum extraction time 19?h approximately. The main phenolic compounds analysed with high performance liquid chromatography were catechin and quercetin with a maximum extraction yield obtained at 29?h (362.23 and 339.35?mg/100?gdw, respectively). Concentration of the polyphenols and their antiradical powers are demonstrated to have a significant linear correlation. PMID:21707256

Casazza, Alessandro A; Aliakbarian, Bahar; Perego, Patrizia

2011-10-01

83

Probability analysis of contact forces in quasi-solid-liquid phase transition of granular shear flow  

NASA Astrophysics Data System (ADS)

The quasi-solid-liquid phase transition exists widely in different fields, and attracts more attention due to its instinctive mechanism. The structure of force chains is an important factor to describe the phase transition properties. In this study, the discrete element model (DEM) is adopted to simulate a simple granular shear flow with period boundary condition on micro scale. The quasi-solid-liquid phase transition is obtained under various volume fractions and shear rates. Based on the DEM results, the probability distribution functions of the inter-particle contact force are obtained in different shear flow phases. The normal, tangential and total contact forces have the same distributions. The distribution can be fitted as the exponential function for the liquid-like phase, and as the Weibull function for the solid-like phase. To describe the progressive evolution of the force distribution in phase transition, we use the Weibull function and Corwin-Ngan function, respectively. Both of them can determine the probability distributions in different phases and the Weibull function shows more reasonable results. Finally, the force distributions are discussed to explain the characteristics of the force chain in the phase transition of granular shear flow. The distribution of the contact force is an indicator to determine the flow phase of granular materials. With the discussions on the statistical properties of the force chain, the phase transition of granular matter can be well understood.

Ji, ShunYing

2013-02-01

84

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

PubMed

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

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

2014-11-14

85

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

86

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

87

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

SciTech Connect

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

Bhave, Ramesh R [ORNL

2012-01-01

88

DCLARATION RELATIVE AUX ACCIDENTS JOINDRE AUX PICES ADMINISTRATIVES DEMANDES  

E-print Network

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

Sart, Remi

89

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

90

Hard spheres revisited: Accurate calculation of the solid-liquid interfacial free energy  

NASA Astrophysics Data System (ADS)

We revise the earlier [R. L. Davidchack and B. B. Laird, Phys. Rev. Lett. 85, 4751 (2000)] direct calculation of the hard sphere solid-liquid interfacial free energy by the cleaving walls method. The revisions of the method include modified interactions with the cleaving walls and the use of a nonequilibrium work measurements approach, which allows for a more robust control of the accuracy of the obtained results. We find that the new values are lower compared to the original ones, which is consistent with the more recent indirect estimates based on extrapolation from the soft-sphere results [R. L. Davidchack and B. B. Laird, Phys. Rev. Lett. 94, 086102 (2005)], as well as those obtained using the capillary fluctuations method [R. L. Davidchack, J. R. Morris, and B. B. Laird, J. Chem. Phys. 125, 094710 (2006)].

Davidchack, Ruslan L.

2010-12-01

91

Measurement of solid liquid interfacial energy in the In Bi eutectic alloy at low melting temperature  

NASA Astrophysics Data System (ADS)

The Gibbs-Thomson coefficient and solid-liquid interfacial energy of the solid In solution in equilibrium with In Bi eutectic liquid have been determined to be (1.46 ± 0.07) × 10-7 K m and (40.4 ± 4.0) × 10-3 J m-2 by observing the equilibrated grain boundary groove shapes. The grain boundary energy of the solid In solution phase has been calculated to be (79.0 ± 8.7) × 10-3 J m-2 by considering force balance at the grain boundary grooves. The thermal conductivities of the In-12.4 at.% Bi eutectic liquid phase and the solid In solution phase and their ratio at the eutectic melting temperature (72 °C) have also been measured with radial heat flow apparatus and Bridgman-type growth apparatus.

Mara?li, N.; Akbulut, S.; Ocak, Y.; Ke?lio?lu, K.; Böyük, U.; Kaya, H.; Çadirli, E.

2007-12-01

92

Solid-liquid phase equilibria of the Gaussian core model fluid  

NASA Astrophysics Data System (ADS)

The solid-liquid phase equilibria of the Gaussian core model are determined using the GWTS [J. Ge, G.-W. Wu, B. D. Todd, and R. J. Sadus, J. Chem. Phys. 119, 11017 (2003)] algorithm, which combines equilibrium and nonequilibrium molecular dynamics simulations. This is the first reported use of the GWTS algorithm for a fluid system displaying a reentrant melting scenario. Using the GWTS algorithm, the phase envelope of the Gaussian core model can be calculated more precisely than previously possible. The results for the low-density and the high-density (reentrant melting) sides of the solid state are in good agreement with those obtained by Monte Carlo simulations in conjunction with calculations of the solid free energies. The common point on the Gaussian core envelope, where equal-density solid and liquid phases are in coexistence, could be determined with high precision.

Mausbach, Peter; Ahmed, Alauddin; Sadus, Richard J.

2009-11-01

93

Solid-liquid phase equilibria of the Gaussian core model fluid.  

PubMed

The solid-liquid phase equilibria of the Gaussian core model are determined using the GWTS [J. Ge, G.-W. Wu, B. D. Todd, and R. J. Sadus, J. Chem. Phys. 119, 11017 (2003)] algorithm, which combines equilibrium and nonequilibrium molecular dynamics simulations. This is the first reported use of the GWTS algorithm for a fluid system displaying a reentrant melting scenario. Using the GWTS algorithm, the phase envelope of the Gaussian core model can be calculated more precisely than previously possible. The results for the low-density and the high-density (reentrant melting) sides of the solid state are in good agreement with those obtained by Monte Carlo simulations in conjunction with calculations of the solid free energies. The common point on the Gaussian core envelope, where equal-density solid and liquid phases are in coexistence, could be determined with high precision. PMID:19916612

Mausbach, Peter; Ahmed, Alauddin; Sadus, Richard J

2009-11-14

94

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

PubMed

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

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

2007-11-30

95

In Situ Determination of the Nanoscale Chemistry and Behavior of Solid-Liquid Systems  

NASA Astrophysics Data System (ADS)

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

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

2007-11-01

96

Finite difference computation of solid/liquid phase change energy transport - Comparison with experimental data  

NASA Astrophysics Data System (ADS)

A computational model is presented for the prediction of solid/liquid phase change energy transport including the influence of free convection and comparisons made with experimental data for which the phase change material is heated from the side and from below. The computational model considers the velocity components of all nonliquid PCM control volumes to be zero but fully solves the coupled mass-momentum problem within the liquid. The thermal energy model includes the entire domain and employs an enthalpy-like model in addition to recent development for handling the phase change interface non-linearily. The predictions are compared with experimental data for the test problem examined. The present procedure demonstrates both excellent agreement with the experimental data and a significant computational advance for this class of problem.

Schneider, G. E.

1986-01-01

97

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

NASA Astrophysics Data System (ADS)

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

Turci, Francesco; Schilling, Tanja

2014-08-01

98

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

99

Numerical Calculation of the Morphology of a Solid/Liquid Interface near an Insoluble Particle  

NASA Technical Reports Server (NTRS)

A numerical mathematical model capable of accurately describing the evolution of the shape of the solid/liquid interface in the proximity of a foreign particle is presented in this paper. The model accounts for the influence of the temperature gradient and the Gibbs-Thomson and disjoining pressure effects. It shows that for the systems characterized by k(sub P) < k(sub L) the disjoining pressure causes the interface curvature to change its sign in the close-contact particle/interface region. It also shows that the increase of the temperature gradient diminishes the effect of the disjoining pressure. Calculated critical solidification velocities for the pushing/engulfment transition are compared with experimental measurements performed in microgravity conditions.

Catalina, Adrian; Stefanescu, Doru M.; Sen, Subhayu

2003-01-01

100

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

101

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

102

Dependence of solid-liquid interface free energy on liquid structure  

SciTech Connect

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

Wilson, S R [Ames Laboratory; Mendelev, M I [Ames Laboratory

2014-09-01

103

Fluorescence line narrowing spectroscopy of polycyclic aromatic hydrocarbons on solid-liquid extraction membranes.  

PubMed

The potential of solid-liquid extraction fluorescence line narrowing spectroscopy is evaluated for screening polycyclic aromatic hydrocarbons in aqueous samples. Octadecyl silica membranes are used with the dual purpose of sample preconcentration and solid substrate for spectroscopic measurements. 4.2 K fluorescence line narrowed spectra are directly recorded from the membrane with the aid of a fiber-optic probe. The experimental procedure is free from organic solvents and takes less than 5 min per sample. With 10 mL of water sample, the limits of detection are at the parts-per-billion level. Qualitative analysis is based on wavelength time matrices, which provide a unique format for compound identification based on spectral and lifetime data. The selectivity of this approach is demonstrated with the unambiguous determination of naphthalene in a heavily contaminated water sample. PMID:14658704

Bystol, Adam J; Campiglia, Andres D

2003-06-01

104

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

105

First-principles molecular dynamics simulations at solid-liquid interfaces with a continuum solvent  

NASA Astrophysics Data System (ADS)

Continuum solvent models have become a standard technique in the context of electronic structure calculations, yet no implementations have been reported capable to perform molecular dynamics at solid-liquid interfaces. We propose here such a continuum approach in a density functional theory framework using plane-wave basis sets and periodic boundary conditions. Our work stems from a recent model designed for Car-Parrinello simulations of quantum solutes in a dielectric medium [D. A. Scherlis et al., J. Chem. Phys. 124, 074103 (2006)], for which the permittivity of the solvent is defined as a function of the electronic density of the solute. This strategy turns out to be inadequate for systems extended in two dimensions: the dependence of the dielectric function on the electronic density introduces a new term in the Kohn-Sham potential, which becomes unphysically large at the interfacial region, seriously affecting the convergence of the self-consistent calculations. If the dielectric medium is properly redefined as a function of the atomic coordinates, a good convergence is obtained and the constant of motion is conserved during the molecular dynamics simulations. The Poisson problem is solved using a multigrid method, and in this way Car-Parrinello molecular dynamics simulations of solid-liquid interfaces can be performed at a very moderate computational cost. This scheme is employed to investigate the acid-base equilibrium at the TiO2-water interface. The aqueous behavior of titania surfaces has stimulated a large amount of experimental research, but many open questions remain concerning the molecular mechanisms determining the chemistry of the interface. Here we make an attempt to answer some of them, putting to the test our continuum model.

Sánchez, Verónica M.; Sued, Mariela; Scherlis, Damián A.

2009-11-01

106

First-principles molecular dynamics simulations at solid-liquid interfaces with a continuum solvent.  

PubMed

Continuum solvent models have become a standard technique in the context of electronic structure calculations, yet no implementations have been reported capable to perform molecular dynamics at solid-liquid interfaces. We propose here such a continuum approach in a density functional theory framework using plane-wave basis sets and periodic boundary conditions. Our work stems from a recent model designed for Car-Parrinello simulations of quantum solutes in a dielectric medium [D. A. Scherlis et al., J. Chem. Phys. 124, 074103 (2006)], for which the permittivity of the solvent is defined as a function of the electronic density of the solute. This strategy turns out to be inadequate for systems extended in two dimensions: the dependence of the dielectric function on the electronic density introduces a new term in the Kohn-Sham potential, which becomes unphysically large at the interfacial region, seriously affecting the convergence of the self-consistent calculations. If the dielectric medium is properly redefined as a function of the atomic coordinates, a good convergence is obtained and the constant of motion is conserved during the molecular dynamics simulations. The Poisson problem is solved using a multigrid method, and in this way Car-Parrinello molecular dynamics simulations of solid-liquid interfaces can be performed at a very moderate computational cost. This scheme is employed to investigate the acid-base equilibrium at the TiO(2)-water interface. The aqueous behavior of titania surfaces has stimulated a large amount of experimental research, but many open questions remain concerning the molecular mechanisms determining the chemistry of the interface. Here we make an attempt to answer some of them, putting to the test our continuum model. PMID:19894999

Sánchez, Verónica M; Sued, Mariela; Scherlis, Damián A

2009-11-01

107

Static and dynamic electrowetting of an ionic liquid in a solid/liquid/liquid system.  

PubMed

A droplet of an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, bmim.BF(4)) is immersed in an immiscible liquid (n-hexadecane) and electrowetted on a flat Teflon AF1600-coated ITO electrode. The static contact angle decreases significantly when voltage is applied between the droplet and the electrode: from 145 degrees down to 50 degrees (with DC voltage) and 15 degrees (with AC voltage). The electrowetting curves (contact angle versus voltage) are similar to the ones obtained in other solid/liquid/vapor and solid/liquid/liquid systems: symmetric with respect to zero voltage and correctly described by Young-Lippmann equation below saturation. The reversibility is excellent and contact angle hysteresis is minimal (approximately 2 degrees). The step size used in applying the DC voltage and the polarity of the voltage are unimportant. The saturation contact angle cannot be predicted with the simple zero-interfacial tension theory. Spreading (after applying a DC voltage) and retraction (after switching off the voltage) of the droplet is monitored. The base area of the droplet varies exponentially during wetting (exponential saturation) and dewetting (exponential decay). The characteristic time is 20 ms for spreading and 35 ms for retraction (such asymmetry is not observed with water-glycerol mixtures of a similar viscosity). The spreading kinetics (dynamic contact angle versus contact line speed) can be described by the hydrodynamic model (Voinov's equation) for small contact angles and by the molecular-kinetic model (Blake's equation) for large contact angles. The role of viscous and molecular dissipation follows the scheme outlined by Brochard-Wyart and de Gennes. PMID:20507151

Paneru, Mani; Priest, Craig; Sedev, Rossen; Ralston, John

2010-06-23

108

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

E-print Network

Chemical Spills, Releases, Explosions, Exposures, or Injuries (includes corrosive, reactive, flammable, and toxic chemicals in solid, liquid or gas form) EHS Contact: Kate Lumley-Sapanski (kxl3@psu apply: When to Report: · All chemical exposures or explosions requiring medical attention must

Maroncelli, Mark

109

Temperature-reversible ultrathin films of N-isopropylacrylamide terpolymer adsorbed at the solid-liquid interface.  

PubMed

This article describes the stability and reversibility of ultrathin films of N-isopropylacrylamide (NIPA)-vinylimidazole (VI)-poly(ethylene glycol) (PEG) graft terpolymer adsorbed at the solid-liquid interface upon temperature cycling from below to above its phase transition temperature. The coil-to-globule and globule-to-coil phase transitions were captured by in situ fluid tapping atomic force microscopy (AFM). The film thickness of 1 nm was determined by AFM, X-ray photoelectron spectroscopy, and X-ray reflectivity. The concentration required to reach full coverage was found to be higher when adsorption occurred below the phase transition temperature. From 23 to 42 degrees C, the adsorbed NIPA terpolymer film was observed to be molecularly smooth, corresponding to the close-packed structure of flexible polymer coils. Particles containing between one and a few globules appeared abruptly at the interface at 42-43 degrees C, the same temperature as the solution phase transition temperature, which was determined by dynamic light scattering. The size of the particles did not change with temperature, whereas the number of particles increased with increasing temperature up to 60 degrees C. The particles correspond to the collapsed and associated state of the globules. The film morphological changes were found to be reversible upon temperature cycling. Subtle differences were observed between dip-coated and spin-coated films that are consistent with a higher degree of molecular freedom for spin-coated films. The study contributes to the fundamental understanding and applications of smart ultrathin films and coatings. PMID:17963410

Wan, Lei; Bisht, Harender S; You, Ye-Zi; Oupicky, David; Mao, Guangzhao

2007-11-20

110

Fundamental measure density functional theory study of hard spheres solid-liquid interface  

NASA Astrophysics Data System (ADS)

Interfacial free energy is an important characteristic of solid-liquid interface as it is one of the crucial parameters in many formula of interface thermodynamics such the nucleation theory. Previously different aspects of crystal-melt interfaces were intensively studied with simulations [1,2,3], but theoretical studies with Density Functional Theories (DFT) are inconclusive [4,5]. In this report the structure of hard spheres fcc crystal-melt interfaces and the anisotropy of the interfacial free energies are studied using the Rosenfeld's Fundamental Measure DFT as such a functional leads to reliable coexistence results not only for the hard sphere system but also for the Lennard-Jones systems [6]. The parameters of interfacial density profile were calculated by a proper minimization procedure. For the equilibrium density profile the interfacial free energies were compared with simulation results. 1. R.L.Davidchak and B.B.Laird, Phys.Rev.Lett., 85, 4751(2000). 2. J.J. Hoyt, M. Asta and A. Karma, Phys.Rev.Lett., 86, 5530 (2001). 3. J.R.Morris and X.Song, J.Chem.Phys., 119, 3920 (2003). 4. W.A.Curtin, Phys.Rev.B, 39, 6775(1989). 5. R.Ohnesorge, H.Lowen, and H.Wagner, Phys.Rev.E, 50, 4801 (1994). 6. V.Warshavsky and X.Song, Phys.Rev.E, 69, 061113 (2004).

Warshavsky, Vadim

2005-03-01

111

Calculation of excess interfacial entropy, stress and energy for solid-liquid interfaces  

NASA Astrophysics Data System (ADS)

The solid-liquid interfacial free energy, ?sl, governs a number of important phenomena, e.g., crystal nucleation and growth, and wetting. For an equilibrium crystal-melt interface, ?sl can be calculated via simulation using thermodynamic integration or capillary fluctuations [Phys. Chem. B 109, 17802 (2005)]. The calculation of ?sl away from coexistence requires the temperature and strain dependence of ?sl, which can be determined from the excess interfacial entropy, ?sl, and stress tensor, ?sl. We determine ?sl and ?sl for a system of Lennard-Jones particles and for particles with an inverse-power interaction [?(r) = ?(?/r)^n] for n = 6, 8 (fcc and bcc) and 12, 20 (fcc). We determine ?sl and ?sl for the (100), (110) and (111) orientations. We calculate ?sl using two methods, both using the Gibbs dividing surface defined so that the excess interfacial particle number is zero. In the first, we calculate ?sl from the temperature dependence of ?sl, ?sl and the number density, ?, along the coexistence curve. In the second, we calculate the excess interfacial energy, esl, and use the equation ?sl= esl- T ?sl. The results agree within estimated errors. One surprising observation is that ?sl, esl and ?sl are significantly more anisotropic than ?sl.

Laird, Brian B.; Davidchack, Ruslan L.; Asta, Mark; Yang, Yang

2009-03-01

112

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

NASA Astrophysics Data System (ADS)

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

Castillo, Gustavo; Mujica, Nicolás; Soto, Rodrigo

2015-01-01

113

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

PubMed

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

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

2015-02-01

114

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

PubMed

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

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

2015-01-27

115

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.

116

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

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

117

Coarsening in Solid-liquid Mixtures: Overview of Experiments on Shuttle and ISS  

NASA Technical Reports Server (NTRS)

The microgravity environment on the Shuttle and the International Space Station (ISS) provides the ideal condition to perform experiments on Coarsening in Solid-Liquid Mixtures (CSLM) as deleterious effects such as particle sedimentation and buoyancy-induced convection are suppressed. For an ideal system such as Lead-Tin in which all the thermophysical properties are known, the initial condition in microgravity of randomly dispersed particles with local clustering of solid Tin in eutectic liquid Lead-Tin matrix, permitted kinetic studies of competitive particle growth for a range of volume fractions. Verification that the quenching phase of the experiment had negligible effect of the spatial distribution of particles is shown through the computational solution of the dynamical equations of motion, thus insuring quench-free effects from the coarsened microstructure measurements. The low volume fraction experiments conducted on the Shuttle showed agreement with transient Ostwald ripening theory, and the steady-state requirement of LSW theory was not achieved. More recent experiments conducted on ISS with higher volume fractions have achieved steady-state condition and show that the kinetics follows the classical diffusion limited particle coarsening prediction and the measured 3D particle size distribution becomes broader as predicted from theory.

Duval, Walter M. B.; Hawersaat, Robert W.; Lorik, T.; Thompson, J.; Gulsoy, B.; Voorhees, P. W.

2013-01-01

118

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

NASA Astrophysics Data System (ADS)

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

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

2006-01-01

119

How solid-liquid adhesive property regulates liquid slippage on solid surfaces?  

PubMed

The influence of solid-liquid adhesive property on liquid slippage at solid surfaces has been investigated using experiment approach on well-defined model surfaces as well as theoretical analysis. Based on a classical molecular-kinetic description for molecular and hydrodynamic slip, we propose a simple theoretical model that directly relates the liquid slip length to the liquid adhesive force on solid surfaces, which yields an exponential decay function. Well-defined smooth surfaces with varied surface wettability/adhesion are fabricated by forming self-assembled monolayers on gold with different mole ratios of hydrophobic and hydrophilic thiols. The adhesive force of a water droplet and the molecular slippage on these surfaces are probed by surface force apparatus and quartz crystal microbalance measurements, respectively. The experiment results are well consistent with our theoretical prediction. Our finding benefits the understanding of the underlying mechanism of liquid slippage on solid surfaces at molecular level and the rational design of microfluidics with an aim to be frictionless or highly controllable. PMID:25511171

Xue, Yahui; Wu, Yang; Pei, Xiaowei; Duan, Huiling; Xue, Qunji; Zhou, Feng

2015-01-13

120

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

SciTech Connect

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

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

2003-06-01

121

Solid-liquid separation of oxidized americium from fission product lanthanides  

NASA Astrophysics Data System (ADS)

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

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

2010-03-01

122

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

123

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

124

Design selection of lubricant application methods for tribological elements -- Solid, liquid, gas and multiphase  

SciTech Connect

Selecting a lubrication system for tribological machine elements can be a serious task when one has the choice of gas, liquid, solid and multiphase lubricants. This paper compares these systems showing present limits of operation and research goals for future machines. Relative costs, reliability and expected life are presented for several specific systems.

Rylander, H.G. [Univ. of Texas, Austin, TX (United States). Dept. of Mechanical Engineering

1997-07-01

125

Cationic flocculants carrying hydrophobic functionalities: applications for solid/liquid separation.  

PubMed

The flocculation behaviors of three series of polycations with narrow molecular weight distributions carrying hydrophobic substituents on their backbones [poly(N-vinylbenzyl-N,N,N-trimethylammonium chloride), poly(N-vinylbenzyl-N,N-dimethyl-N-butylammonium chloride), and poly(N-vinylbenzylpyridinium chloride)] were investigated in dispersions of monodisperse polystyrene latexes and kaolin. Apparently, the charge density of the polycations decreases with increasing substituent hydrophobicity and increasing molecular weight of the polyelectrolytes. The necessary amount of flocculant for phase separation in dispersions with high substrate surface charge densities increases with increasing hydrophobicity of the polyelectrolyte. Nevertheless, the introduction of hydrophobic functionalities is beneficial, resulting in a substantial broadening of the range between the minimum and maximum amounts of flocculant necessary for efficient flocculation (flocculation window). An increase in ionic strength supports this effect. When the substrate has a low charge density, the hydrophobic interactions play a much more significant role in the flocculation process. Here, the minimum efficient doses remained the same for all three polyelectrolytes investigated, but the width of the flocculation window increased as the polycation hydrophobicity and the molecular weight increased. The necessary amount of flocculant increased with an increase in particle size at constant solid content of the dispersion, as well as with a decreasing number of particles at a constant particle size. PMID:17608514

Schwarz, S; Jaeger, W; Paulke, B-R; Bratskaya, S; Smolka, N; Bohrisch, J

2007-07-26

126

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

NASA Astrophysics Data System (ADS)

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

Chan, Matthew Wei-Jen

127

Adsorption and conformation of carboxymethyl cellulose at solid-liquid interfaces using spectroscopic, AFM and allied techniques.  

PubMed

Carboxymethyl cellulose (CMC) is a polysaccharide which is widely used in many industrial sectors including food, textiles, paper, adhesives, paints, pharmaceutics, cosmetics and mineral processing. It is a natural organic polymer that is non-toxic and biodegradable. These properties make it ideal for industrial applications. However, a general lack of understanding of the interaction mechanism between the polysaccharides and solid surfaces has hindered the application of this polymer. In this work, adsorption of CMC at the solid-liquid interface is investigated using adsorption and electrophoretic mobility measurements, FTIR, fluorescence spectroscopy, AFM and molecular modeling. CMC adsorption on talc was found to be affected significantly by changes in solution conditions such as pH and ionic strength, which indicates the important role of electrostatic force in adsorption. The pH effect on adsorption was further proven by AFM imaging. Electrokinetic studies showed that the adsorption of CMC on talc changed its isoelectric point. Further, molecular modeling suggests a helical structure of CMC in solution while it is found to adsorb flat on the solid surface to allow its OH groups to be in contact with the surface. Fluorescence spectroscopy studies conducted to investigate the role of hydrophobic bonding using pyrene probe showed no evidence of the formation of hydrophobic domains at talc-aqueous interface. Urea, a hydrogen bond breaker, markedly reduced the adsorption of CMC on talc, supports hydrogen bonding as an important factor. In FTIR study, the changes to the infrared bands, associated with the CO stretch coupled to the CC stretch and OH deformation, were significant and this further supports the strong hydrogen bonding of CMC to the solid surface. In addition, Langmuir modeling of the adsorption isotherm suggests hydrogen bonding to be a dominant force for polysaccharide adsorption since the adsorption free energy of this polymer was close to that for hydrogen bond formation. All of the above results suggest that the main driving forces for CMC adsorption on talc are a combination of electrostatic interaction and hydrogen bonding rather than hydrophobic force. PMID:15907862

Wang, Jing; Somasundaran, P

2005-11-01

128

The influence of spatial and temporal averaging on interpretation of HRTEM images of solid-liquid interfaces.  

PubMed

The effects of spatial and temporal averaging on high-resolution transmission electron microscope (HRTEM) images and associated intensity profiles of a solid-liquid Al interface were investigated using atomic coordinates obtained from molecular dynamics simulations. It was found that intensity profiles obtained by spatial averaging across the solid-liquid interface capture the variation in structural features nearly as well as time-averaged intensity profiles. This suggests that adequate spatial averaging of a single HRTEM image can be used to study the contrast from interfaces, and thereby, the structural details, without the need for more time-consuming, computer-intensive time averaged analyses. The limitations of this method are also discussed. PMID:23142743

Eswara Moorthy, Santhana K; Mendelev, Mikhail I; Howe, James M

2013-01-01

129

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

130

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

Microsoft Academic Search

Chitosan acetate nano-fibers were fabricated via a solid–liquid phase separation technique. The chitosan acetate structure was influenced by phase separation temperature, chitosan concentration and acetic acid concentration. Uniform nano-fibrous chitosan acetate of 50–500nm in diameter was engineered at 0.05% (w\\/v) chitosan and 0.025% (v\\/v) acetic acid in liquid nitrogen, as opposed to film-shape and micro-fibrous structure at ?18°C and ?80°C

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

2011-01-01

131

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

132

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

PubMed Central

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

2013-01-01

133

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

PubMed

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

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

2013-01-01

134

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

135

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

PubMed

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

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

2011-01-01

136

Solid-liquid coexistence in ionic systems and the properties of the interface  

NASA Astrophysics Data System (ADS)

The crystal-melt interfaces of pure KCl and LiCl crystals with (Li,K)Cl melts of various compositions have been investigated by direct simulation of coexisting crystalline and molten regions. This system forms no solid compounds involving both lithium and potassium and exhibits a eutectic close to the equimolar composition. Simulations at various melt compositions allow the liquidus to be determined and compared with experiment. In order to test the precision achievable by a direct simulation of coexisting liquid and solid phases for the thermodynamic properties, we make preliminary calculations on the melting of a model of NaCl, which has recently been studied by Anwar et al. [2003, J. chem. Phys., 118, 728] using thermodynamic integration. Including anionic polarization, effects in the interionic interaction model lower the melting temperature, despite the fact that there is no discernible effect on the liquid or solid structure in these simple monovalent melts. The method of direct simulation of coexistence also allows for the study of the interfacial structure and dynamics. These can be compared with previous studies [Davidchack, R. L., and Laird, B. B., 1998, J. chem. Phys., 108, 9452; Sibug-Aga, R., and Laird, B. B., 2002, J. chem. Phys., 116, 3410] of the solid-liquid interfaces in binary mixtures of hard spheres of sufficiently different size ratio to prevent solid compound formation. Despite the additional Coulombic interactions the ionic interfaces resemble the hard spheres in many regards, but there are differences. For example, when traversing the interface the perpendicular diffusion rises more rapidly than the parallel diffusion, most likely due to charge ordering.

Lanning, Oliver J.; Shellswell, Stephen; Madden, Paul A.

2004-01-01

137

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

PubMed

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

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

2013-05-21

138

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

SciTech Connect

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

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

2011-10-25

139

A bottom-up approach to understanding protein layer formation at solid-liquid interfaces.  

PubMed

A common goal across different fields (e.g. separations, biosensors, biomaterials, pharmaceuticals) is to understand how protein behavior at solid-liquid interfaces is affected by environmental conditions. Temperature, pH, ionic strength, and the chemical and physical properties of the solid surface, among many factors, can control microscopic protein dynamics (e.g. adsorption, desorption, diffusion, aggregation) that contribute to macroscopic properties like time-dependent total protein surface coverage and protein structure. These relationships are typically studied through a top-down approach in which macroscopic observations are explained using analytical models that are based upon reasonable, but not universally true, simplifying assumptions about microscopic protein dynamics. Conclusions connecting microscopic dynamics to environmental factors can be heavily biased by potentially incorrect assumptions. In contrast, more complicated models avoid several of the common assumptions but require many parameters that have overlapping effects on predictions of macroscopic, average protein properties. Consequently, these models are poorly suited for the top-down approach. Because the sophistication incorporated into these models may ultimately prove essential to understanding interfacial protein behavior, this article proposes a bottom-up approach in which direct observations of microscopic protein dynamics specify parameters in complicated models, which then generate macroscopic predictions to compare with experiment. In this framework, single-molecule tracking has proven capable of making direct measurements of microscopic protein dynamics, but must be complemented by modeling to combine and extrapolate many independent microscopic observations to the macro-scale. The bottom-up approach is expected to better connect environmental factors to macroscopic protein behavior, thereby guiding rational choices that promote desirable protein behaviors. PMID:24484895

Kastantin, Mark; Langdon, Blake B; Schwartz, Daniel K

2014-05-01

140

Bubble Induced Disruption of a Planar Solid-Liquid Interface During Controlled Directional Solidification in a Microgravity Environment  

NASA Technical Reports Server (NTRS)

Pore Formation and Mobility Investigation (PFMI) experiments were conducted in the microgravity environment aboard the International Space Station with the intent of better understanding the role entrained porosity/bubbles play during controlled directional solidification. The planar interface in a slowing growing succinonitrile - 0.24 wt% water alloy was being observed when a nitrogen bubble traversed the mushy zone and remained at the solid-liquid interface. Breakdown of the interface to shallow cells subsequently occurred, and was later evaluated using down-linked data from a nearby thermocouple. These results and other detrimental effects due to the presence of bubbles during solidification processing in a microgravity environment are presented and discussed.

Grugel, Richard N.; Brush, Lucien N.; Anilkumar, Amrutur V.

2013-01-01

141

In-Situ Observations of Interaction Between Particulate Agglomerates and an Advancing Planar Solid/Liquid Interface: Microgravity Experiments  

NASA Technical Reports Server (NTRS)

Results are reported of directional solidification experiments on particulate agglomerate pushing and engulfment by a planar solid/liquid (s/1) interface. These experiments were conducted on the Space Shuttle Columbia during the United States Microgravity Payload 4 (USMP-4) Mission. It was found that the pushing to engulfment transition velocity, V(sub ct),, for agglomerates depends not only on their effective size but also their orientation with respect to the s/l interface. The analytical model for predicting V(sub cr) of a single particle was subsequently enhanced to predict V(sub cr) of the agglomerates by considering their shape factor and orientation.

Sen, S.; Juretzko, F.; Stefanescu, D. M.; Dhindaw, B. K.; Curreri, P. A.

1999-01-01

142

In Situ Observations of Interaction Between Particulate Agglomerates and an Advancing Planar Solid/Liquid Interface: Microgravity Experiments  

NASA Technical Reports Server (NTRS)

Results are reported of directional solidification experiments on particulate agglomerate pushing and engulfment by a planar solid/liquid (s/l) interface. These experiments were conducted on the Space Shuttle Columbia during the United States Microgravity Payload 4 (USMP-4) Mission. It was found that the pushing to engulfment transition velocity, V(sub cr) for agglomerates depends not only on their effective size but also their orientation with respect to the s,1 interface. The analytical model for predicting V(sub cr) of a single particle was subsequently enhanced to predict V(sub cr) of the agglomerates by considering their shape factor and orientation.

Sen, S.; Juretzko, F.; Stafanescu, D. M.; Dhindaw, B. K.; Curreri, P. A.

1999-01-01

143

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

NASA Technical Reports Server (NTRS)

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

Schneider, G. E.

1991-01-01

144

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

E-print Network

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

Di Girolami, Cristina

145

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

PubMed

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

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

2014-01-01

146

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

147

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

148

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

PubMed

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

Ma, Xiao-kui; Daugulis, Andrew J

2014-01-01

149

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

PubMed

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

Warzoha, Ronald J; Fleischer, Amy S

2014-08-13

150

Télédétection des algues macrophytes de I'Archipel de Molene (France) Radiometrie de terrain et application aux donnees du satellite SPOT  

Microsoft Academic Search

Resumé. A partir de I' étude des données radiométriques de terrain un algorithme de traitement d'images satellitaires a été développé pour la cartographie des végétaux marins. Son application a l'imagerie SPOT a permis de distinguer, en zone immergée, jusqu' á une profondeur de 12m la nature du fond, recouvert ou non par la végétation. En zone intertidale exondee la couverture

H. BEN MOUSSA; M. VIOLLIER; et T. BELSHER

1989-01-01

151

Solid liquid interfacial energy of the solid Mg2Zn11 phase in equilibrium with Zn Mg eutectic liquid  

NASA Astrophysics Data System (ADS)

The Gibbs-Thomson coefficient and solid-liquid interfacial energy of the solid Mg2Zn11 phase in equilibrium with Zn-Mg eutectic liquid have been determined to be (3.3 ± 0.2) × 10-8 K m and (20.8 ± 2.1) × 10-3 J m-2 from the equilibrated grain boundary groove shapes with a numerical model. The grain boundary energy of the solid Mg2Zn11 phase has been calculated to be (40.9 ± 4.5) × 10-3 J m-2 by considering a force balance at the grain boundary grooves. The thermal conductivity ratio of the eutectic Zn-Mg liquid phase to the solid Mg2Zn11 phase has also been found to be 0.81.

Erol, M.; Keslioglu, K.; Marasli, N.

2007-04-01

152

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

PubMed

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

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

2013-05-01

153

Exploring the solid-liquid phase change of an adapted Dzugutov model using generalized replica exchange method.  

PubMed

The generalized replica exchange method (gREM) is applied to simulate a solid-liquid phase change in an adapted Dzugutov model system. The idea of gREM is to incorporate the merit of sampling from a generalized ensemble into the replica exchange paradigm. The generalized ensemble weights are determined from effective temperatures tailored for this system, through an inverse mapping strategy. The ordered and disordered phases are smoothly joined together through a succession of unimodal energy distributions, providing a continuous transformation from an isotropic liquid into an amorphous solid phase under the given condition. The phase change temperature is determined by evaluation of various thermodynamic and structural order parameters. The increasing tendency for icosahedral local order under cooling is quantified using bond order parameters. The ergodic measure is used to demonstrate the advantage of gREM over the traditional temperature-based REM in sampling the phase change region. PMID:22452532

Lu, Qing; Kim, Jaegil; Straub, John E

2012-07-26

154

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

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

155

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

PubMed Central

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

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

2014-01-01

156

Thermal transport behavior of van der waals solids and liquids in the neighborhood of the solid-liquid phase transition  

SciTech Connect

The thermal conductivity, lambda, is one of the few transport coefficients which shows a relatively small change at the solid-liquid phase transition, and hence it is a property that can be used in comparing dynamic properties of both ordered and disordered systems. Although the discontinuity in lambda can be accounted for largely by the difference in density, /rho/, of solid and liquid at the phase transition, its volume dependence is examined more closely. The thermal diffusivity, which is known to dominate the dynamic structure factor of liquid argon, has been determined around the phase transition also; the sound velocity has been considered in addition. The results are discussed and a comparison is made with these properties in solid and liquid benzene and cyclohexane.

Van Loef, J.J.; Hauley, H.J.M.; Cezairliyan, A.

1986-01-01

157

Resonant anomalous x-ray reflectivity as a probe of ion adsorption at solid-liquid interfaces.  

SciTech Connect

We discuss new opportunities to understand processes at the solid-liquid interface using resonant anomalous X-ray reflectivity (RAXR). This approach is illustrated by determination of element-specific density profiles at mica surfaces in aqueous electrolyte solutions containing Rb{sup +} and Sr{sup 2+}. The total interfacial electron density profile is determined by specular reflectivity (i.e., reflected intensity vs. momentum transfer, q, at an energy, E, far from any characteristic absorption edge). RAXR spectra (i.e., intensity vs. E at fixed q) reveal element-specific ion distributions. Key differences in the interaction of Rb{sup +} and Sr{sup 2+} with mica are observed using resonant anomalous X-ray reflectivity: Rb{sup +} adsorbs in a partially hydrated state, but Sr{sup 2+} adsorbs in both fully and partially hydrated states.

Fenter, P.; Park, C.; Nagy, K. L.; Sturchio, N. C.; Chemistry; Univ. of Illinois at Chicago

2007-05-23

158

Surface density of cellobiohydrolase on crystalline celluloses. A critical parameter to evaluate enzymatic kinetics at a solid-liquid interface.  

PubMed

The enzymatic kinetics of glycoside hydrolase family 7 cellobiohydrolase (Cel7A) towards highly crystalline celluloses at the solid-liquid interface was evaluated by applying the novel concept of surface density (rho) of the enzyme, which is defined as the amount of adsorbed enzyme divided by the maximum amount of adsorbed enzyme. When the adsorption levels of Trichoderma viride Cel7A on cellulose I(alpha) from Cladophora and cellulose I(beta) from Halocynthia were compared, the maximum adsorption of the enzyme on cellulose I(beta) was approximately 1.5 times higher than that on cellulose I(alpha), although the rate of cellobiose production from cellulose I(beta) was lower than that from cellulose I(alpha). This indicates that the specific activity (k) of Cel7A adsorbed on cellulose I(alpha) is higher than that of Cel7A adsorbed on cellulose I(beta). When k was plotted versus rho, a dramatic decrease of the specific activity was observed with the increase of surface density (rho-value), suggesting that overcrowding of enzyme molecules on a cellulose surface lowers their activity. An apparent difference of the specific activity was observed between crystalline polymorphs, i.e. the specific activity for cellulose I(alpha) was almost twice that for cellulose I(beta). When cellulose I(alpha) was converted to cellulose I(beta) by hydrothermal treatment, the specific activity of Cel7A decreased and became similar to that of native cellulose I(beta) at the same rho-value. These results indicate that the hydrolytic activity (rate) of bound Cel7A depends on the nature of the crystalline cellulose polymorph, and an analysis that takes surface density into account is an effective means to evaluate cellulase kinetics at a solid-liquid interface. PMID:16759230

Igarashi, Kiyohiko; Wada, Masahisa; Hori, Ritsuko; Samejima, Masahiro

2006-07-01

159

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

160

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

161

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

E-print Network

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

Kottmann, Stephen Thomas

2008-01-01

162

In-situ surface x-ray scattering of metal monolayers adsorbed at solid-liquid interfaces  

NASA Astrophysics Data System (ADS)

The structure of the solid-liquid interface is of fundamental importance in chemistry, but progress in understanding this interface has been slow, due to the lack of in-situ probes that provide information at atomic scales. Recently, in-situ surface x-ray scattering measurements have provided insight into the microscopic nature of solid-liquid interfaces and this paper discusses experiments on electrochemically deposited monolayers of Pb, Tl, and Bi on Ag and Au (111) electrodes. Tl and Pb form 2-D, incommensurate hexagonal solids that are compressed relative to bulk and rotated by 4 - 5 degree(s) with respect to the substrate. As the applied electrode potential decreases, the in-plane atomic spacing also decreases, since the chemical potential of the monolayer increases. From these data, the 2-D compressibility of the monolayer can be calculated. We find that the compressibility is only slightly dependent on substrate, being smaller on Ag(111) than on Au(111). For Tl/Ag(111), the intensity of the Ag surface diffraction changes when the monolayer is adsorbed. This results from a substrate- induced modulation of the atomic positions in the incommensurate monolayer and we have quantified this modulation. Bi/Ag(111) forms an unusual structure: a rectangular lattice that is uniaxially commensurate with the hexagonal surface. There are two Bi adatoms per rectangular unit cell and one adatom is displaced from the centered position by 0.35 angstrom. The commensurate Bi rows lie along the rows of threefold hollow sites on the Ag(111) surface. This unusual structure reflects the tendency toward covalent bonding found in Bi and a fortuitous match between the atomic spacings of the Ag substrate and the close packed planes of bulk Bi. In contrast to Tl and Pb where the compressibility is isotropic, Bi/Ag(111) compresses anisotropically and this maintains the uniaxially commensurate structure. Our results show that for these metal monolayer systems the adatom-adatom interactions determine the atomic structure of the monolayer and the adatom-substrate interactions only weakly affect this structure. Furthermore, the structure is not influenced by the presence of the large concentration of adsorbed water molecules or anions.

Toney, Michael F.; Gordon, Joseph G., II; Melroy, Owen R.

1991-11-01

163

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

164

Application de l'cologie comportementale aux  

E-print Network

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

Blouin-Demers, Gabriel

165

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

PubMed

Thermal rectification, the origin of which lies in modifying the thermal resistance in a nonlinear manner, could significantly improve the thermal management of a wide range of nano-devices (both electronic and thermoelectric), thereby improving their efficiencies. Since rectification requires a material to be inhomogeneous, it has been typically associated with solids. However, the structure of solids is relatively difficult to manipulate, which makes the tuning of thermal rectification devices challenging. Since liquids are more amenable to tuning, this could open up new applications for thermal rectification. We use molecular dynamics simulations to demonstrate thermal rectification using liquid water. This is accomplished by creating an inhomogeneous water phase, either by changing the morphology of the surface in contact with the liquid or by imposing an arbitrary external force, which in practice could be through an electric or magnetic field. Our system consists of a bulk fluid that is confined in a reservoir that is bounded by two walls, one hot and the other cold. The interfacial (Kapitza) thermal resistance at the solid-fluid interface and the density gradient of the bulk fluid both influence the magnitude of the thermal rectification. However, we find that the role of the interfacial resistance is more prominent than the application of an external force on the bulk fluid. PMID:22938211

Murad, Sohail; Puri, Ishwar K

2012-08-28

166

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

PubMed

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

Zhang, Cunsheng; Su, Haijia; Tan, Tianwei

2013-10-01

167

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

PubMed

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

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

2015-02-01

168

Model for a solid-liquid stirred tank two-phase partitioning bioscrubber for the treatment of BTEX.  

PubMed

A dynamic mathematical model has been developed to predict the performance of a stirred tank, solid-liquid two-phase partitioning bioreactor (SL-TPPB) for the treatment of benzene, toluene, ethylbenzene and o-xylene (BTEX) contaminated gases. The SL-TPPB system consists of an aqueous phase containing a bacterial consortium and a solid phase of silicone rubber beads (10%; v/v) with a high affinity for BTEX compounds. The silicone rubber beads serve to sequester and release BTEX according to thermodynamic equilibrium, which increases mass transfer from the gas phase and reduces aqueous phase concentrations of these toxic compounds during fluctuating inlet loadings. The model was developed from mass balances on BTEX components in the gas, aqueous and polymer phases, and biomass in the aqueous phase. Dynamic experimental data from this system were used to fit model parameters and to assess the accuracy of the model. A detailed estimability analysis of model parameters and initial conditions was completed to identify uncertain parameters that are most influential for the model predictions and to determine the parameters and initial conditions that should be targeted for estimation using the dynamic data. It was found that the developed model, with estimated parameters and initial conditions, has the ability to predict experimental off-gas BTEX concentrations with reasonable accuracy, which are the outputs of greatest importance. PMID:19959280

Littlejohns, Jennifer V; McAuley, Kim B; Daugulis, Andrew J

2010-03-15

169

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

NASA Astrophysics Data System (ADS)

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

Bayram, Ü.; Aksöz, S.; Mara?l?, N.

2012-01-01

170

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

171

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

2012-10-23

172

Selective solid-liquid extraction of lithium halide salts using a ditopic macrobicyclic receptor.  

PubMed

A ditopic salt receptor that is known to bind and extract solid NaCl, KCl, NaBr, and KBr into organic solution as their contact ion pairs is now shown by NMR and X-ray crystallography to bind and extract solid LiCl and LiBr as water-separated ion pairs. The receptor can transport these salts from an aqueous phase through a liquid organic membrane with a cation selectivity of K+ > Na+ > Li+. However, the selectivity order is strongly reversed when the receptor extracts solid alkali metal chlorides and bromides into organic solution. For a three-component mixture of solid LiCl, NaCl, and KCl, the ratio of salts extracted and complexed to the receptor in CDCl3 was 94:4:2, respectively. The same strong lithium selectivity was also observed in the case of a three-component mixture of solid LiBr, NaBr, and KBr where the ratio of extracted salts was 92:5:3. This observation is attributed to the unusually high solubility of lithium salts in organic solvents. The study suggests that ditopic receptors with an ability to extract solid salts as associated ion pairs may have application in separation processes. PMID:15554626

Mahoney, Joseph M; Beatty, Alicia M; Smith, Bradley D

2004-11-29

173

Fabrication and characterization of porous poly(L-lactide) scaffolds using solid-liquid phase separation.  

PubMed

Freeze-extraction, which involves phase separation principle, gave highly porous scaffolds without the time and energy consuming freeze-drying process. The presented method eliminates the problem of formation of surface skin observed in freeze-drying methods. The effects of different freezing temperature (-80 and -24 degrees C), medium (dry ice/ethanol bath and freezer) and polymer concentrations (1, 3, and 5 wt.%) on the scaffold properties were investigated in connection with the porous morphology and physicomechanical characteristics of the final scaffolds. The FESEM micrographs showed porous PLLA scaffolds with ladder-like architecture. The size of the longitudinal pores was in the range of 20-40 microm and the scaffolds had high porosity values ranging from 90% to 98%. Variation in porosity, mechanical resistance, and degree of regularity in the spatial organization of pores were observed when polymer concentration was changed. More open scaffold architecture with enhanced pore interconnectivity was achieved when a dry ice/ethanol bath of -80 degrees C was used. Polymer concentration played an important role in fabricating highly porous scaffolds, with ladder-like architecture only appearing at polymer concentrations of above 3 wt.%. With the freeze-extraction method used here, highly porous and interconnected poly(L-lactide) scaffolds were successfully fabricated, holding great potential for tissue engineering applications. PMID:18219558

Goh, Yan Qi; Ooi, Chui Ping

2008-06-01

174

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

Microsoft Academic Search

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

Ahmet Sar?

2004-01-01

175

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

Microsoft Academic Search

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

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

2010-01-01

176

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

177

Electrochemical impedance and surface plasmon resonance studies of reactions at solid-liquid interfaces  

NASA Astrophysics Data System (ADS)

The interface created by the presence of a solid material placed in a liquid environment can be studied using electrochemical impedance spectroscopy (EIS) and surface plasmon resonance (SPR). A selected set of systems are studied using these techniques and explored as is relevant to their applications in chemical mechanical planarization (CMP) and for the development of chemical and biological sensors. Studies of Cu in the presence of KI was performed as a means of exploring the capabilities of EIS for determining the differential capacitance (C diff) under potentiodynamic conditions, and examine the constraints and experimental variables present for such measurements. The use of Cu in the presence of KI was a sample system for these measurements and also provided us with the opportunity to examine the specific adsorption of I- on Cu which is relevant to CMP of Cu. EIS was also applied to study of Ta in the presence of KIO3. This system used EIS measurements to examine the specific surface reactions that occur during the CMP of Ta, due to the presence of KIO3, in order to explore other means of chemically or electrochemically removing excess material after it is deposited on nano-scale structures. We propose that the presence of KIO3 supports similar reactions to those reported by us for peroxide based alkaline solutions and will therefore result in the same soluble hexatantalate complex. The formation of a self-assembled molecule (SAM) of 11-mercaptoundecanoic acid (MUA) on thin film gold was studied using SPR. The kinetics of the formation of the MUA layer on the Au surface in ethanol and the kinetics associated with the conformational changes in MUA due to changes in the pH of the ambient aqueous solution were explored by examining the changes in the structural and optical characteristics of the MUA layer. The formation of MUA exhibited simple Langmuir kinetics during early and late stages in the formation and reorientation during the intermediate stages. The ionization/neutralization of the MUA tail groups occurs rapidly with slower changes in the alkaline solution resulting from cation-binding to the ionized tail groups. Simultaneous nonfaradaic adsorption and faradaic reactions were studied using a combination of time resolved EIS and cyclic voltammetry (CV) techniques to examine the role of DC reactions in the measured AC response of such systems. These reactions were studied under potentiodynamic conditions in 0.1 M NaF on a thin film Au electrode with and without 1 mM Cl-. Time-resolved impedance spectra were recorded under transient conditions of CV, and electrode-equivalent circuit (EEC) models are obtained as functions of the CV scans. These results demonstrate how the relative roles of DC and AC effects in potentiodynamically acquired EECs can be analyzed to study detailed kinetics of surface reactions.

Pettit, Christopher

178

Numerical Calculation of the Drag Force Acting on a Solid Particle Pushed by a Solid/Liquid Interface  

NASA Technical Reports Server (NTRS)

The distribution of insoluble particles in a metal casting depends primarily on the interaction of the particles with the solid/liquid interface (SLI) during the solidification process. The balance of the forces acting on the particle essentially determines whether a particle will be engulfed or pushed by the SLI. An important component of this force balance is the drag force generated by the particle motion in front of the SLI. Previously developed mathematical models for particle/SLI interaction made use of steady-state solutions of this force provided by the lubrication theory. However, our numerical model based on the SLI tracking approach shows that the steady-state approach is inappropriate to model the interaction process and that at steady-state the theoretical solution underestimates the drag force. It was found that regression analysis of steady-state numerical solutions for cylindrical particles moving normal to a flat SLI gives a relationship of the form: Abstract The distribution of insoluble particles in a metal casting depends primarily on the interaction of the particles with the solid/liquid interface (SLI) during the solidification process. The balance of the forces acting on the particle essentially determines whether a particle will be engulfed or pushed by the SLI. An important component of this force balance is the drag force generated by the particle motion in front of the SLI. Previously developed mathematical models for particle/SLI interaction made use of steady-state solutions of this force provided by the lubrication theory. However, our numerical model based on the SLI tracking approach shows that the steady-state approach is inappropriate to model the interaction process and that at steady-state the theoretical solution underestimates the drag force. It was found that regression analysis of steady-state numerical solutions for cylindrical particles moving normal to a flat SLI gives a relationship of the form: F(sub D, sup num) =sqoare root of 3(pi)(eta)V(sub p)(R(sub p)/d)(sup 10(gamma)/3). This is to compared to the solution provided by the lubrication theory: F(sub D), sup theor) = 3 square root of 2(pi)(eta)V(sub p)(R(sub p)/d)(sub 3/2), where F(sub D) is the drag force, eta is the dynamic viscosity of the fluid, V(sub p) is the particle velocity, R(sub p) is the particle radius, gamma is Euler's constant (gamma approx. = 0.577), and d is the width of the gap between the particle and the SLI. The domain on which the equations proposed by the lubrication theory are relevant is clearly identified in the paper. The numerical model was then validated against the classical lubrication theory within the domain of its validity.

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

2000-01-01

179

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

PubMed

Melatonin is normally consumed to regulate the body's biological cycle. However it also has therapeutic properties, such as anti-tumor, anti-aging and protects the immune system. There are some reports on the presence of melatonin in edible kernels such as walnuts, but the extraction of melatonin from pistachio kernels is reported here for the first time. For this, the methanolic extract of pistachio kernels was exposed to gas chromatography/mass spectrometry analysis which confirmed the presence of melatonin. A fluorescence-based method was applied for the determination of melatonin in different extracts. When excited at ?=275 nm, the fluorescence emission intensity of melatonin was measured at ?=366 nm. Ultrasound-assisted solid-liquid extraction was used for the extraction of melatonin from pistachio kernels prior to fluorimetric determination. To achieve the highest extraction recovery, the main parameters affecting the extraction efficiency such as extracting solvent type and volume, temperature, sonication time and pH were evaluated. Under the optimized conditions, a linear dependence of fluorescence intensity on melatonin concentration was observed in the range of 0.0040-0.160 ?g mL(-1), with a detection limit of 0.0036 ?g mL(-1). This method was applied successfully for measuring and comparing the melatonin content in the kernels of four different varieties of Pistacia including Ahmad Aghaei, Akbari, Kalle Qouchi and Fandoghi. In addition, the results obtained were compared with those obtained using GC/MS. A good agreement was observed indicating the reliability of the proposed method. PMID:24878439

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

2014-11-11

180

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

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

181

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

PubMed

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

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

2007-01-01

182

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

SciTech Connect

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

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

2014-06-07

183

Solid-liquid nuclear magnetic resonance relaxation and signal amplitude relationships with ranking of seasoned softwoods and hardwoods  

NASA Astrophysics Data System (ADS)

In H1 NMR (nuclear magnetic resonance) relaxation measurements for a set of eight hardwood and softwood samples, each free induction decay (FID) is fitted by the sum of a "solid" signal of the form Aexp[-c(t /TS)2][1-g(t/TS)2+h(t/TS)4] plus a "liquid" signal Bexp(-t /T2-FID). Distributions of longitudinal (T1) relaxation times were computed separately for the solid and liquid components, giving also the solid/liquid H1 ratio ?. From measurements on the samples dried, seasoned, and hydrated, the moisture content (liquid/solid weight ratio) was found to be approximately 0.50/?. For each of the "seasoned" samples (10%-13% moisture content) a single T1 peak was found for the solid and two for the liquid, with the longer liquid T1 close to that of the solid, but with some differences exceeding perceived experimental uncertainties. None of the solid or liquid-long T1's is much less than 20ms, even though liquid-short times go as low as 0.35ms, appearing to negate simple solid-to-liquid exchange on a millisecond time scale. Data for six of the samples (all except for two resin-containing pine species) can be formally fitted by a two-site exchange model, in which cases the solid-to-liquid exchange times are a few tens of milliseconds. For our set of wood samples, each of the above three T1 values, and also the overall liquid geometric-mean and rate-average T1's, as well as the liquid long-T1 fraction, for a seasoned hardwood is longer than the corresponding value for any softwood, suggesting that relaxation parameters may provide a useful ranking of seasoned woods.

Fantazzini, P.; Maccotta, A.; Gombia, M.; Garavaglia, C.; Brown, R. J. S.; Brai, M.

2006-10-01

184

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

185

Former aux comptences TIC et aux comptences informationnelles : des objectifs intimement lis en formation  

E-print Network

Former aux compétences TIC et aux compétences informationnelles : des objectifs intimement liés en.dumouchel@umontreal.ca Université de Montréal Résumé: Pour mieux comprendre la forte relation qui existe entre les compétences TIC enchaînons avec une vue d'ensemble des études empiriques sur le niveau des compétences TIC et

Paris-Sud XI, Université de

186

Collaborateurs aux lignes directrices en soins primaires  

PubMed Central

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

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

2015-01-01

187

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

188

Electrical impedance tomography combined with FEM calculations for fast measurements of the concentration and velocity distributions in horizontal pipes for solid-liquid mixtures  

SciTech Connect

The contribution will present the results of a number of tests the author ran during the last years with respect to the behavior of solid-liquid mixtures in test rigs. Two main subjects will be dealt with: the evaluation of the concentration distribution in a horizontal pipeline and the velocity of the solid matter transported. The objective is to overcome the great uncertainties recognized in commercial systems using inductive flowmeters and {gamma}-ray density meters. The results of th is theoretical and experimental work will be presented and discussed.

Wiedenroth, W.

1996-12-31

189

Pathologie vgtale (synthse) Rsistances aux herbicides  

E-print Network

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

Boyer, Edmond

190

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

191

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

NASA Astrophysics Data System (ADS)

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

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

2010-06-01

192

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

NASA Astrophysics Data System (ADS)

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

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

2005-03-01

193

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

NASA Astrophysics Data System (ADS)

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

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

194

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

NASA Astrophysics Data System (ADS)

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

Lu, Chun-Yaung; Voter, Arthur F.; Perez, Danny

2014-01-01

195

Methane production from cattle waste in laboratory reactors at 40/sup 0/ and 60/sup 0/C after solid-liquid separation  

SciTech Connect

Whole dairy waste and liquid effluent separated from the same waste with a solid-liquid separator were fermented at mesophilic and thermophilic temperatures. Chemical analyses of the two materials were similar. Methane production was superior in thermophilic reactors. With substrates adjusted to 4.1% volatile solids, average methane production at 60/sup 0/C (166 ml/g volatile solids fed to reactors at 3- and 6-day retention time) was as efficient as at 40/sup 0/C (162 ml/g at 5- and 10-day retention times). Thermophilic reactors produced 1.67 liter methane/liter reactor per day as compared to .93 liter for mesophilic reactors. Efficiency of methanogenesis was no greater for whole waste than for separated effluent. Production of methane for the two substrates averaged over retention times and temperatures was 156 ml/g volatile solids fed to reactor for whole waste and 173 ml/g for separated effluent.

Rorick, M.B.; Spahr, S.L.; Bryant, M.P.

1980-11-01

196

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

PubMed

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

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

2014-09-01

197

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

PubMed

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

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

2014-02-01

198

FAS1005 : Introduction aux sciences humaines Automne 2013  

E-print Network

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

Parrott, Lael

199

RSISTIVIT LECTRIQUE DU BISMUTH IRRADI AUX NEUTRONS RAPIDES  

E-print Network

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

Paris-Sud XI, Université de

200

A new white light photosedimentometer for solid-liquid dispersion study: device description, stability and settling behaviour  

Microsoft Academic Search

This paper describes a new photosedimentation device that monitors and measures the settling rate, hindered settling, constant, flocculation factor, sediment volume and rate of coagulation of monodisperse samples of solid particulates in dispersant liquids. First we examine the well-known theoretical aspects of sedimentation as well as some sedimentation and turbidity applications. Then we introduce the K200 photosedimentometer and most of

P. Caron; B. Faucompré; F. Membrey; A. Foissy

1996-01-01

201

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

2013-11-01

202

Transferts aux petites chelles : application au rayonnement thermique, aux forces de Casimir et la  

E-print Network

states close to an interface 55 Coupled surface polaritons and the Casimir force 67 Coherent spontaneous. Surprisingly similar failure of common sense was put forward by the recent progress of near-field optical subwavelength spatial information do not propa- gate far away from the object. However, a great deal of work

Paris-Sud XI, Université de

203

Design and optimization of ultrasound assisted extraction of curcumin as an effective alternative for conventional solid liquid extraction of natural products.  

PubMed

The first step in the qualitative and quantitative analysis of medicinal plant constituents is the extraction step. Ideally, an extraction procedure should be exhaustive with respect to the constituents to be analyzed, rapid, simple, and for routine analysis amenable to automation. Usually, the traditional techniques require long extraction times, with more consumption of energy resources and organic solvent, have low efficiency and are often unsafe for thermolabile botanicals. The Taguchi based optimization technique was adapted for the process optimization of ultrasound assisted extraction (UAE) of Curcuma longa to identify the effect of four major factors namely, extraction time, solvent viscosity, grinding degree and solvent volume on the percentage extraction of curcumin. The reproducibility and recovery of the method was also investigated. The efficiency of the new extraction method was then compared with conventional solid liquid extraction procedures. Using this novel method, long hours of conventional Soxhlet extraction were cut down to 70 minutes of UAE with greater reproducibility and recovery. The study clearly shows that this method can be effectively utilized for cutting down long extraction time of botanicals to just a few minutes without the aid of heat. PMID:19370883

Mandal, Vivekananda; Dewanjee, Saikat; Sahu, Ranabir; Mandal, Subhash C

2009-01-01

204

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

205

Solid Liquid Interdiffusion Bonding of (Pb, Sn)Te Thermoelectric Modules with Cu Electrodes Using a Thin-Film Sn Interlayer  

NASA Astrophysics Data System (ADS)

A (Pb, Sn)Te thermoelectric element plated with a Ni barrier layer and a Ag reaction layer has been joined with a Cu electrode coated with Ag and Sn thin films using a solid-liquid interdiffusion bonding method. This method allows the interfacial reaction between Ag and Sn such that Ag3Sn intermetallic compounds form at low temperature and are stable at high temperature. In this study, the bonding strength was about 6.6 MPa, and the specimens fractured along the interface between the (Pb, Sn)Te thermoelectric element and the Ni barrier layer. Pre-electroplating a film of Sn with a thickness of about 1 ?m on the thermoelectric element and pre-heating at 250°C for 3 min ensures the adhesion between the thermoelectric material and the Ni barrier layer. The bonding strength is thus increased to a maximal value of 12.2 MPa, and most of the fractures occur inside the thermoelectric material. During the bonding process, not only the Ag3Sn intermetallics but also Cu6Sn5 forms at the Ag3Sn/Cu interface, which transforms into Cu3Sn with increases in the bonding temperature or bonding time.

Chuang, T. H.; Lin, H. J.; Chuang, C. H.; Yeh, W. T.; Hwang, J. D.; Chu, H. S.

2014-12-01

206

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

207

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

208

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

PubMed Central

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

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

2013-01-01

209

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

PubMed

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

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

2014-11-01

210

L’influence du degré d’aversion à l’inégalité du décideur sur sa perception des inégalités intragroupes et intergroupes : une application de l’alpha décomposition aux salaires de la France entre 1995 et 2005  

Microsoft Academic Search

Nous proposons dans cette recherche de mettre en avant le rôle capital joué par les préférences du décideur sur sa perception des inégalités intragroupes et intergroupes. Une application réalisée à partir des salaires observés en France entre 1995 et 2005 révèle notamment de grands écarts de valeurs entre les différents indicateurs choisis pour évaluer l’évolution des disparités salariales sur la

Pauline MORNET; Françoise SEYTE; Michel TERRAZA

2012-01-01

211

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

212

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

SciTech Connect

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

Prof. P. Somasundaran

2002-03-01

213

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

NASA Astrophysics Data System (ADS)

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

Omura, Yoko

1998-03-01

214

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

215

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

E-print Network

« Hommage aux morts de la France combattante » Pierre Brossolette Albert Hall, Londres, 18 juin Analyse En rendant un hommage passionné aux morts de la France Combattante, le 18 juin 1943 à l 18 juin, le fondateur de la France Libre dépose une gerbe au monument aux morts de la Grande Guerre

Paris-Sud XI, Université de

216

Plant embryogenesis requires AUX/LAX-mediated auxin influx.  

PubMed

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

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

2015-02-15

217

HOMMES ET FEMMES FACE AUX INGALITS ET LA PAUVRET  

E-print Network

HOMMES ET FEMMES FACE AUX IN�GALIT�S ET � LA PAUVRET� AU TRAVAIL Pascale ABSI, Pascale PH�LINAS, publié dans "La mondialisation au risque des travailleurs (2007) 53-73" #12;ABSI P., PHELINAS P., SELIM M

Boyer, Edmond

218

Bienvenue aux gays du monde entier . Tourisme gay et mondialisation  

E-print Network

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

Paris-Sud XI, Université de

219

Une lecture enrichie des réponses aux enquêtes de conjoncture  

Microsoft Academic Search

[fre] Une lecture enrichie des réponses aux enquêtes de conjoncture . . Les enquêtes de conjoncture ont pour objectif d’appréhender, le plus rapidement et le plus simplement possible, les évolutions récentes et probables de l'activité économique. La plupart des questions posées amènent des réponses qualitatives à trois modalités (qualification d’une évolution: en hausse \\/ stable \\/ en baisse). Les indicateurs

François Hild

2002-01-01

220

Article 45 de la loi n° 2005-102 du 11 février 2005 pour l'égalité des droits et des chances, la participation et la citoyenneté des personnes handicapées. Propositions pour l'application aux transports collectifs du Département de la Nièvre  

Microsoft Academic Search

La loi n° 2005-102 du 11 février 2005 vise à donner une nouvelle impulsion à la lutte contre les discriminations vis à vis des personnes handicapées ou à mobilité réduite. Pour cela, le législateur impose la mise en accessibilité de toute la chaîne de déplacement à l'horizon 2015. Cette loi s'adresse en priorité aux Autorités Organisatrices des Transports chargée de

Xavier Badia

2006-01-01

221

Phenomena associated with melting and supercooling in aluminum and the solid-liquid interface in an aluminum-silicon base alloy investigated by in-situ analytical transmission electron microscopy  

NASA Astrophysics Data System (ADS)

Crystal growth is an important technique for controlling the microstructure of materials, and hence, studies pertaining to crystal growth are crucial for developing new materials with novel properties. The present research explores the behavior of the core and valence electrons, and the nearest-neighbor atomic distance during heating and cooling of pure Al through the melting temperature, as well as the properties associated with the solid-liquid interface in a commercially important Al-Si-Cu-Mg alloy, using in-situ analytical transmission electron microscopy (TEM). Electron energy-loss spectroscopy (EELS) in a TEM was used to follow changes in the valence electron density through the melting temperature and during supercooling in pure Al particles. A non-linear plasmon energy change observed during heating solid Al is due to a phonon anharmonicity that is not present in liquid Al during heating. Similarly, a non-linear plasmon behavior observed during supercooling liquid Al could due to local ordering in the liquid. Comparing the full-width at half-maximum of the plasmon peaks show that damping of plasmons is faster in liquid than in solid Al due to electron-phonon interactions and/or Anderson localization. The extended energy-loss fine structure (EXEFLS) in the EELS spectrum is sensitive to the nearest-neighbor atomic distance and coordination in a material. A comparison of the nearest-neighbor distance and the inverse volume plasmon energy change through the melting temperature shows good agreement in the solid Al, whereas the correlation is less good in liquid Al because thermal vibrations (Debye-Waller factor) dampen the EXELFS oscillation at high temperatures. A qualitative comparison of the energy-loss near edge spectra (ELNES) of solid and liquid Al in both superheated and supercooled states shows that their partial electron density of states are quantitatively different and that the presence or absence of crystallinity is the most important factor contributing to the ELNES. The partitioning of solute elements was investigated by measuring the Cu concentrations in solid Si, liquid Al and at the solid-liquid interface at 585 °C, where the particle is partially molten, and subsequently undercooling to 565 and 470 °C. The Cu concentration after fluorescence correction was compared with thermodynamic calculations. The results shows that Cu segregation during undercooling assists in nucleating Al2Cu prior to Mg 2Si phase at a high-index Si facet-liquid Al interface under non-equilibrium conditions. The heterogeneous segregation of Cu at the interface was determined to be a thermodynamically driven process by measuring the Cu concentration in liquid Al and at the solid-liquid interface for prolonged times at temperature. The plasmon at a solid-liquid interface in an Al-Si alloy particle was investigated by stepping a 0.6 nm diameter electron beam at 0.8 nm increments across a singular Si{111}-liquid Al interface in sub-eV, sub-A microscope (SESAM). Low energy-loss spectra acquired across solid-liquid interface were compared with calculations using dielectric theory. The result shows that a unique plasmon resonance is present at the interface between the crystalline Si and liquid Al, thereby giving rise to a plasmon peak at 15.5 eV between the Si (16.3 eV) and liquid Al (14.2 eV) plasmons in the experimental EEL spectra. This result was corroborated with energy-filtered TEM. The intensity profile across the solid-liquid interface in the energy-filtered image shows that the interface plasmon signal is delocalized to within ˜5.5 nm of the interface.

Palanisamy, Prakash

222

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

Microsoft Academic Search

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

Christomir Christov; Andrew G. Dickson; Nancy Moller

2007-01-01

223

ANDR KASPI La peine de mort aux tats-Unis  

E-print Network

Lectures ANDR� KASPI La peine de mort aux �tats-Unis Paris, Plon, 2003, 250 pages. par Daniel'hui le maintien de la peine de mort, du moins au sein de l'ensemble des pays démocratiques. � son actif contribuant à la fois à une déresponsabilisation généralisée à l'égard de la peine de mort et au renforcement

Boyer, Edmond

224

Extraction and preconcentration of tylosin from milk samples through functionalized TiO? nanoparticles reinforced with a hollow fiber membrane as a novel solid/liquid-phase microextraction technique.  

PubMed

The aim of this study was to introduce a novel, simple, and highly sensitive preparation method for determination of tylosin in different milk samples. In the so-called functionalized TiO2 hollow fiber solid/liquid-phase microextraction method, the acceptor phase is functionalized TiO2 nanoparticles that are dispersed in the organic solvent and held in the pores and lumen of a porous polypropylene hollow fiber membrane. An effective functionalization of TiO2 nanoparticles has been done in the presence of aqueous H2 O2 and a mild acidic ambient under UV irradiation. This novel extraction method showed excellent extraction efficiency and a high enrichment factor (540.2) in comparison with conventional hollow fiber liquid-phase microextraction. All the experiments were monitored at ?max = 284 nm using a simple double beam UV-visible spectrophotometer. A Taguchi orthogonal array experimental design with an OA16 (4(5) ) matrix was employed to optimize the factors affecting the efficiency of hollow fiber solid/liquid-phase microextraction such as pH, stirring rate, salt addition, extraction time, and the volume of donor phase. This developed method was successfully applied for the separation and determination of tylosin in milk samples with a linear concentration range of 0.51-7000 ?g/L (r(2) = 0.991) and 0.21 ?g/L as the limit of detection. PMID:24890459

Sehati, Negar; Dalali, Nasser; Soltanpour, Shahla; Dorraji, Mir Saeed Seyed

2014-08-01

225

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

E-print Network

Questionnements géographiques sur les monuments aux morts : symboliques et territoires de la'armistice mettant fin à la Grande guerre ont réuni différentes générations autour des monuments aux morts. Fait des monuments aux morts de leur commune en ce jour du 11 novembre. Un rituel qui s'ancre dans des

Paris-Sud XI, Université de

226

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

PubMed

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

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

2011-02-01

227

Vaincre la réticence à l’instauration d’un nouveau schéma à base d’enfuvirtide grâce aux soins aux patients et aux mesures de soutien  

PubMed Central

Les patients peuvent être réticents à l’idée de commencer un traitement par l’enfuvirtide en raison de préoccupations relatives à l’auto-injection et à d’autres questions connexes. Étant donné que l’introduction d’une nouvelle classe de médicaments peut améliorer considérablement l’efficacité d’un schéma antirétroviral, appuyer le patient dans l’instauration de l’enfuvirtide, un agent sûr et efficace appartenant à une nouvelle classe, offre des bienfaits thérapeutiques. Dans le cas du présent patient, qui affichait une résistance aux trois grandes classes d’antirétroviraux, l’enfuvirtide a été ajouté avec succès au traitement grâce à un groupe d’aide par les pairs et à une assistance clinique. L’acceptation du patient a augmenté grâce à l’utilisation d’un système d’injection sans aiguilles (Biojector), avec des effets secondaires minimes et une amélioration significative du contrôle virologique et immunologique.

Trottier, Benoît

2007-01-01

228

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

E-print Network

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

Paris-Sud XI, Université de

229

Determination of brilliant green from fish pond water using carbon nanotube assisted pseudo-stir bar solid/liquid microextraction combined with UV-vis spectroscopy-diode array detection  

NASA Astrophysics Data System (ADS)

This paper describes the development of a new design of hollow fiber solid/liquid phase microextraction (HF-SLPME) for determination of brilliant green (BG) residues in water fish ponds. This method consists of an aqueous donor phase and carbon nanotube reinforced organic solvent (acceptor phase) operated in direct immersion sampling mode. The multi-walled carbon nanotube dispersed in the organic solvent is held in the pores and lumen of a porous polypropylene hollow fiber. It is in contact directly with the aqueous donor phase. In this method the solid/liquid extractor phase is supported using a polypropylene hollow fiber membrane. Both ends of the hollow fiber segment are sealed with magnetic stoppers. This device is placed inside the donor solution and plays the rule of a pseudo-stir bar. It is disposable, so single use of the fiber reduces the risk of carry-over problems. Brilliant green (BG) after extraction from the aqueous samples with mentioned HF-SLPME device was determined by ultraviolet-visible spectroscopy with diode array detection (UV-vis/DAD). The absorption wavelength was set to 625 nm ( ?max). The effect of different variables on the extraction was evaluated and optimized to enhance the sensitivity and extraction efficiency of the proposed method. The calibration curve was linear in the range of 1.00-10,000 ?g L -1 of BG in the initial solution with R2 = 0.979. Detection limit, based on three times the standard deviation of the blank, was 0.55 ?g L -1. All experiments were carried out at room temperature (25 ± 0.5 °C).

Es'haghi, Zarrin; Khooni, Maliheh Ahmadi-Kalateh; Heidari, Tahereh

2011-08-01

230

Exposition précoce aux aliments et allergies alimentaires chez les enfants  

PubMed Central

Résumé Question J’étais sous l’impression qu’on devrait éviter de donner aux nourrissons des aliments potentiellement allergènes comme des noix, du lait de vache et des œufs pour prévenir le développement de réactions allergiques. Quels conseils devrait-on donner aux parents concernant l’introduction des aliments durant la petite enfance et le développement des allergies alimentaires? Réponse Il n’y a pas de données probantes indiquant que retarder l’introduction d’aliments particuliers après l’âge de 6 mois aide à prévenir les allergies. Une récente déclaration de la Société canadienne de pédiatrie ne recommande aucun délai quant à l’introduction d’aliments durant la petite enfance. De récentes études de recherche semblent aussi faire valoir que l’introduction précoce (entre 4 et 6 mois) d’aliments possiblement allergènes procure une forme de protection et contribue à prévenir les allergies, mais il faudrait plus de recherche à ce sujet.

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

2014-01-01

231

AUX/LAX family of auxin influx carriers—an overview  

PubMed Central

Auxin regulates several aspects of plant growth and development. Auxin is unique among plant hormones for exhibiting polar transport. Indole-3-acetic acid (IAA), the major form of auxin in higher plants, is a weak acid and its intercellular movement is facilitated by auxin influx and efflux carriers. Polarity of auxin movement is provided by asymmetric localization of auxin carriers (mainly PIN efflux carriers). PIN-FORMED (PIN) and P-GLYCOPROTEIN (PGP) family of proteins are major auxin efflux carriers whereas AUXIN1/LIKE-AUX1 (AUX/LAX) are major auxin influx carriers. Genetic and biochemical evidence show that each member of the AUX/LAX family is a functional auxin influx carrier and mediate auxin related developmental programmes in different organs and tissues. Of the four AUX/LAX genes, AUX1 regulates root gravitropism, root hair development and leaf phyllotaxy whereas LAX2 regulates vascular development in cotyledons. Both AUX1 and LAX3 have been implicated in lateral root (LR) development as well as apical hook formation whereas both AUX1 and LAX1 and possibly LAX2 are required for leaf phyllotactic patterning. PMID:23087694

Swarup, Ranjan; Péret, Benjamin

2012-01-01

232

AUX/LAX family of auxin influx carriers-an overview.  

PubMed

Auxin regulates several aspects of plant growth and development. Auxin is unique among plant hormones for exhibiting polar transport. Indole-3-acetic acid (IAA), the major form of auxin in higher plants, is a weak acid and its intercellular movement is facilitated by auxin influx and efflux carriers. Polarity of auxin movement is provided by asymmetric localization of auxin carriers (mainly PIN efflux carriers). PIN-FORMED (PIN) and P-GLYCOPROTEIN (PGP) family of proteins are major auxin efflux carriers whereas AUXIN1/LIKE-AUX1 (AUX/LAX) are major auxin influx carriers. Genetic and biochemical evidence show that each member of the AUX/LAX family is a functional auxin influx carrier and mediate auxin related developmental programmes in different organs and tissues. Of the four AUX/LAX genes, AUX1 regulates root gravitropism, root hair development and leaf phyllotaxy whereas LAX2 regulates vascular development in cotyledons. Both AUX1 and LAX3 have been implicated in lateral root (LR) development as well as apical hook formation whereas both AUX1 and LAX1 and possibly LAX2 are required for leaf phyllotactic patterning. PMID:23087694

Swarup, Ranjan; Péret, Benjamin

2012-01-01

233

OsAUX1 controls lateral root initiation in rice (Oryza sativa L.).  

PubMed

Polar auxin transport, mediated by influx and efflux transporters, controls many aspects of plant growth and development. The auxin influx carriers in Arabidopsis have been shown to control lateral root development and gravitropism, but little is known about these proteins in rice. This paper reports on the functional characterization of OsAUX1. Three OsAUX1 T-DNA insertion mutants and RNAi knockdown transgenic plants reduced lateral root initiation compared to WT plants. OsAUX1 overexpression plants exhibited increased lateral root initiation and OsAUX1 was highly expressed in lateral roots and lateral root primordia. Similarly, the auxin reporter, DR5-GUS, was expressed at lower levels in osaux1 than in the WT plants, which indicated that the auxin levels in the mutant roots had decreased. Exogenous NAA treatment rescued the defective phenotype in osaux1-1 plants, whereas IAA and 2,4-D could not, which suggested that OsAUX1 was a putative auxin influx carrier. The transcript levels of several auxin-signaling genes and cell cycle genes significantly declined in osaux1, hinting that the regulatory role of OsAUX1 may be mediated by auxin-signaling and cell cycle genes. Overall, our results indicated that OsAUX1 was involved in polar auxin transport and functioned to control auxin-mediated lateral root initiation in rice. PMID:25311360

Zhao, Heming; Ma, Tengfei; Wang, Xin; Deng, Yingtian; Ma, Haoli; Zhang, Rongsheng; Zhao, Jie

2014-10-13

234

Diverse Applications of Pinch Technology Within the Process Industries  

E-print Network

the use of pinch technology in a wider range of industries including food, pulp and paper, cement brewing and dairy product processes. These processes have featured; batch and continuous operations; solids, liquids and gas processing; use... by Linnhoff March. The projects listed include examples from the food, paper, dairy, brewing, cement and speciality chemical industries, and the results illustrate features common to many advanced pinch technology application. Batch Processes Pinch...

Spriggs, H. D.; Ashton, G.

235

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

236

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

NASA Astrophysics Data System (ADS)

One subunit of the prokaryotic voltage-gated potassium ion channel from Aeropyrum pernix (KvAP) is comprised of six transmembrane ? helices, of which S1-S4 form the voltage-sensor domain (VSD) and S5 and S6 contribute to the pore domain (PD) of the functional homotetramer. However, the mechanism of electromechanical coupling interconverting the closed-to-open (i.e., nonconducting-to-K+-conducting) states remains undetermined. Here, we have vectorially oriented the detergent (OG)-solubilized VSD in single monolayers by two independent approaches, namely “directed-assembly” and “self-assembly,” to achieve a high in-plane density. Both utilize Ni coordination chemistry to tether the protein to an alkylated inorganic surface via its C-terminal His6 tag. Subsequently, the detergent is replaced by phospholipid (POPC) via exchange, intended to reconstitute a phospholipid bilayer environment for the protein. X-ray interferometry, in which interference with a multilayer reference structure is used to both enhance and phase the specular x-ray reflectivity from the tethered single membrane, was used to determine directly the electron density profile structures of the VSD protein solvated by detergent versus phospholipid, and with either a moist He (moderate hydration) or bulk aqueous buffer (high hydration) environment to preserve a native structure conformation. Difference electron density profiles, with respect to the multilayer substrate itself, for the VSD-OG monolayer and VSD-POPC membranes at both the solid-vapor and solid-liquid interfaces, reveal the profile structures of the VSD protein dominating these profiles and further indicate a successful reconstitution of a lipid bilayer environment. The self-assembly approach was similarly extended to the intact full-length KvAP channel for comparison. The spatial extent and asymmetry in the profile structures of both proteins confirm their unidirectional vectorial orientation within the reconstituted membrane and indicate retention of the protein's folded three-dimensional tertiary structure upon completion of membrane bilayer reconstitution. Moreover, the resulting high in-plane density of vectorially oriented protein within a fully hydrated single phospholipid bilayer membrane at the solid-liquid interface will enable investigation of their conformational states as a function of the transmembrane electric potential.

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

2011-09-01

237

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

PubMed Central

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

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

2014-01-01

238

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

E-print Network

Le Knowledge Management appliqué aux problématiques de développement Durable dans la Supply Chain Management appliqué aux problématiques de Développement Durable dans la Supply Chain Résumé Le concept de, Knowledge Management, Supply Chain, Nonaka, Modèle SECI halshs-00534785,version1-10Nov2010 #12

Paris-Sud XI, Université de

239

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

Microsoft Academic Search

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

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

1996-01-01

240

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

PubMed

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

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

2015-02-01

241

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

PubMed

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

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

2015-01-01

242

Canalization of auxin flow by Aux/IAA-ARF-dependent feedback regulation of PIN polarity  

PubMed Central

Plant development is characterized by a profound ability to regenerate and form tissues with new axes of polarity. An unsolved question concerns how the position within a tissue and cues from neighboring cells are integrated to specify the polarity of individual cells. The canalization hypothesis proposes a feedback effect of the phytohormone auxin on the directionality of intercellular auxin flow as a means to polarize tissues. Here we identify a cellular and molecular mechanism for canalization. Local auxin application, wounding, or auxin accumulation during de novo organ formation lead to rearrangements in the subcellular polar localization of PIN auxin transport components. This auxin effect on PIN polarity is cell-specific, does not depend on PIN transcription, and involves the Aux/IAA-ARF (indole-3-acetic acid-auxin response factor) signaling pathway. Our data suggest that auxin acts as polarizing cue, which links individual cell polarity with tissue and organ polarity through control of PIN polar targeting. This feedback regulation provides a conceptual framework for polarization during multiple regenerative and patterning processes in plants. PMID:17043314

Sauer, Michael; Balla, Jozef; Luschnig, Christian; Wi?niewska, Justyna; Reinöhl, Vilém; Friml, Ji?í; Benková, Eva

2006-01-01

243

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

PubMed Central

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

Monavari, Sanam; Galbe, Mats; Zacchi, Guido

2009-01-01

244

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

Microsoft Academic Search

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

Vivek Kumar Singh; Awadhesh Kumar Rai

2011-01-01

245

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

246

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

PubMed

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

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

2012-09-15

247

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

PubMed

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

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

2014-01-01

248

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.

249

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

USGS Publications Warehouse

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

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

1999-01-01

250

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

E-print Network

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

Paris-Sud XI, Université de

251

La privatisation en Pologne : d'une approche plurielle aux difficultés de la privatisation de masse  

Microsoft Academic Search

[fre] La privatisation en Pologne : d'une approche plurielle aux difficultés de la privatisation de masse . La part du secteur privé dans le PIB polonais a franchi depuis 1 993 le seuil des 50 %. Cette progression provient en premier lieu du dynamisme de l'initiative privée qui s'est manifestée par la création ex nihilo de nouvelles entreprises. Le succès

Jean-François Nivet

1994-01-01

252

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

E-print Network

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

Boyer, Edmond

253

Recherche d'effets quantitatifs associs aux gnotypes AA et Aa un locus  

E-print Network

Recherche d'effets quantitatifs associés aux génotypes AA et Aa à un locus marqueur avec dominance - Lorsqu'on identifie par épreuve de descendance les individus de génotype AA et Aa à un locus marqueur associated with the AA and Aa genotypes at a marker locus with complete dominance : optimization of progeny

Paris-Sud XI, Université de

254

URRAQUE, BON AMOUR ET AUTRES PETITS NOMS CHARMANTS (observations littraires et historiques aux strophes 910 949  

E-print Network

1 URRAQUE, BON AMOUR ET AUTRES PETITS NOMS CHARMANTS (observations littéraires et historiques aux). Les langues néo-latines (Déc. 2005). « Urraque, bon amour et autres petits noms charmants ». P. 5 Amour et le replace dans l'architecture narrative du Livre : le narrateur protagoniste continue d

Paris-Sud XI, Université de

255

Des amnagements pitons pour un accs plus attractif aux transports publics ?  

E-print Network

­ tramway ­ urbanisme ­ aménagement ­ marche à pied Cette communication s'inscrit dans le champ des'arrêt, des conditions permettant aux transports collectifs d'offrir une alternative crédible à la voiture des modes actifs,... - autant de dispositifs, parmi d'autres, susceptibles d'augmenter la part modale

Paris-Sud XI, Université de

256

La transposition du concept de trahison interpersonnelle aux relations entre marques et clients  

E-print Network

1 La transposition du concept de trahison interpersonnelle aux relations entre marques et clients Cette communication constitue le premier résultat d'un programme de recherche sur la trahison relations entre marques et clients : réflexions conceptuelles et étude exploratoire Résumé Cette recherche

Paris-Sud XI, Université de

257

L'INDEPENDANCE DU COMMISSAIRE AUX COMPTES : UNE ANALYSE EMPIRIQUE BASEE  

E-print Network

de contrôle ­ Niveau de croyance dans un monde juste. Abstract Three psychological components of auditor behaviour confronted with an audit conflict situation have been studied. The most independent'indépendance correspond à la capacité de résistance de l'auditeur aux pressions des dirigeants de l'entreprise (Watts et

Boyer, Edmond

258

DE L'ANALYSE CONOMIQUE DU CRIME AUX NOUVELLES CRIMINOLOGIES ANGLO-SAXONNES?  

E-print Network

DE L'ANALYSE �CONOMIQUE DU CRIME AUX NOUVELLES CRIMINOLOGIES ANGLO-SAXONNES? Les origines sécurité partout dans le monde. L'article pose la question de l'origine des nouvelles criminologies qui ins conception du criminel comme acteur rationnel. Aujourd'hui, les criminologies influentes dans le monde anglo

Paris-Sud XI, Université de

259

Vers un modle d'indexation smantique adapt aux dossiers mdicaux de patients  

E-print Network

Vers un modèle d'indexation sémantique adapté aux dossiers médicaux de patients Duy Dinh, Lynda (2010) 325-336" #12;Duy Dinh, Lynda Tamine 1. Introduction Les systèmes d'information médicaux ont connu

Boyer, Edmond

260

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

261

AUX/LAX Genes Encode a Family of Auxin Influx Transporters That Perform Distinct Functions during Arabidopsis Development[C][W  

PubMed Central

Auxin transport, which is mediated by specialized influx and efflux carriers, plays a major role in many aspects of plant growth and development. AUXIN1 (AUX1) has been demonstrated to encode a high-affinity auxin influx carrier. In Arabidopsis thaliana, AUX1 belongs to a small multigene family comprising four highly conserved genes (i.e., AUX1 and LIKE AUX1 [LAX] genes LAX1, LAX2, and LAX3). We report that all four members of this AUX/LAX family display auxin uptake functions. Despite the conservation of their biochemical function, AUX1, LAX1, and LAX3 have been described to regulate distinct auxin-dependent developmental processes. Here, we report that LAX2 regulates vascular patterning in cotyledons. We also describe how regulatory and coding sequences of AUX/LAX genes have undergone subfunctionalization based on their distinct patterns of spatial expression and the inability of LAX sequences to rescue aux1 mutant phenotypes, respectively. Despite their high sequence similarity at the protein level, transgenic studies reveal that LAX proteins are not correctly targeted in the AUX1 expression domain. Domain swapping studies suggest that the N-terminal half of AUX1 is essential for correct LAX localization. We conclude that Arabidopsis AUX/LAX genes encode a family of auxin influx transporters that perform distinct developmental functions and have evolved distinct regulatory mechanisms. PMID:22773749

Péret, Benjamin; Swarup, Kamal; Ferguson, Alison; Seth, Malvika; Yang, Yaodong; Dhondt, Stijn; James, Nicholas; Casimiro, Ilda; Perry, Paula; Syed, Adnan; Yang, Haibing; Reemmer, Jesica; Venison, Edward; Howells, Caroline; Perez-Amador, Miguel A.; Yun, Jeonga; Alonso, Jose; Beemster, Gerrit T.S.; Laplaze, Laurent; Murphy, Angus; Bennett, Malcolm J.; Nielsen, Erik; Swarup, Ranjan

2012-01-01

262

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

PubMed Central

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

Nigam, Deepti; Sawant, Samir V

2013-01-01

263

LE CHOIX DES ANTISEPTIQUES POUR LES PDILUVES DESTINS AUX BOVINS  

E-print Network

applications. On the other hand, weak organic matter resistance which seems to characterize Javel water des utilisateurs, on a donc réalisé, dans des conditions réelles d'uti- lisation, la comparaison de

Paris-Sud XI, Université de

264

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

E-print Network

COURBES D'IONISATION DANS LE KRYPTON ET LE X�NON PURS RELATIVES AUX RAYONS 03B1 DU POLONIUM Par R polonium dans le krypton et le xénon purs. Les parcours trouvés sont : RKr = 3,03 ± 0,01 cm; RXe = 2,17 ± 0 xénon purs relatives aux rayons a du p'olonium. - En utilisant un appareil spécialement construit pour

Paris-Sud XI, Université de

265

Sections efficaces absolues de l'ozone 298 K aux longueurs d'onde de la lampe au mercure  

E-print Network

L-105 Sections efficaces absolues de l'ozone à 298 K aux longueurs d'onde de la lampe au mercure aofit 1984, revise le 3 decembre, accepte le 13 decembre 1984) Résumé. 2014 En raison de l'importance que présente la connaissance des sections efficaces de l'ozone aux longueurs d'onde de la lampe au

Boyer, Edmond

266

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

E-print Network

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

Paris-Sud XI, Université de

267

The aux1 gene of the Ri plasmid is sufficient to confer auxin autotrophy in tobacco BY-2 cells.  

PubMed

Tobacco (Nicotiana tabacum) Bright Yellow-2 (BY-2) cells are rapidly proliferating meristematic cells that require auxin for culture in vitro. We have established several transgenic BY-2 cell lines that carry the T-DNA of Agrobacterium rhizogenes 15834, which harbors an agropine-type root-inducing (Ri) plasmid. Two of these lines, BYHR-3 and BYHR-7, were used to test the role of auxin in the proliferation of plant cells. The lines grew rapidly in Linsmaier-Skoog (LS) medium lacking auxin and other phytohormones. The TR-DNA, containing the aux1 (tryptophan monooxygenase) and aux2 (indoleacetamide hydrolase) genes, was present in the genomes of both transgenic lines, whereas the TL-DNA, containing the rolA, B, C and D genes, was present in the genome of BYHR-7 but not BYHR-3. Since the introduction of the rolABCD genes alone did not affect the auxin requirement of BY-2 cells, the aux1 and aux2 genes, but not the rolABCD genes, appear to be relevant to the auxin autotrophy of these transgenic lines. Furthermore, the overexpression of aux1 allowed BY-2 cells to grow rapidly in the absence of auxin, suggesting the existence in plant cells of an unidentified gene whose product is functionally equivalent or similar to that of aux2 of the Ri plasmid. PMID:18986729

Nemoto, Keiichirou; Hara, Masamitsu; Goto, Shingo; Kasai, Kouji; Seki, Hikaru; Suzuki, Masashi; Oka, Atsuhiro; Muranaka, Toshiya; Mano, Yoshihiro

2009-05-01

268

Aide aux dplacements l'tranger des enseignants-chercheurs de l'Universit du Maine  

E-print Network

Aide aux déplacements à l'étranger des enseignants-chercheurs de l'Université du Maine retour'Université du Maine Le Service Recherche et le Service des Relations Internationales ont mis en place un-chercheurs, chercheurs et doctorants des laboratoires de l'Université du Maine. Il s'agit d'une aide strictement soumise

Di Girolami, Cristina

269

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

E-print Network

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

Canet, Léonie

270

COURBE D'IONISATION DANS L'HYDROGNE PUR RELATIVE AUX RAYONS ALPHA DU POLONIUM  

E-print Network

COURBE D'IONISATION DANS L'HYDROG�NE PUR RELATIVE AUX RAYONS ALPHA DU POLONIUM Par MM. FR�D�RIC rayons 03B1 du polonium dans l'hydrogène pur. On donne17,30 ± 0,03 cm pour le parcours extrapolé dans l utilisé un support de source permettant de couvrir le polonium avec un écran d'aluminium très mince et

Paris-Sud XI, Université de

271

Actualit scientifiqueActualit scientifique L'ADN : de la biologie aux  

E-print Network

Actualité scientifiqueActualité scientifique L'ADN : de la biologie aux technologies, un nouveau efforts pour séquencer l'ADN à travers un nanopore ou, plus récemment, par manipulation mécanique. Si l ont permis de mettre au point une filière industrielle de synthèse d'ADN,des méthodes de modifi

Ingrand, François

272

CONDUCTIBILIT THERMIQUE DE GRAPHITE QUASI MONOCRISTALLIN ET EFFETS D'IRRADIATION AUX NEUTRONS  

E-print Network

951. CONDUCTIBILIT� THERMIQUE DE GRAPHITE QUASI MONOCRISTALLIN ET EFFETS D'IRRADIATION AUX NEUTRONS. Résumé. 2014 On a mesuré entre 6 et 300 °K la conductibilité thermique K d'un graphite pyrolytique recuit graphite est très bien organisé et très voisin du monocristal. Les résultats obtenus pour K montrent un

Paris-Sud XI, Université de

273

Gopolitiques de Brest 2010 Migrations forces et vulnrabilits diffrencies face aux  

E-print Network

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

Paris-Sud XI, Université de

274

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

E-print Network

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

Halazonetis, Thanos

275

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

NASA Astrophysics Data System (ADS)

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

Kadioglu, Y.; Üzengi Aktürk, O.; Tomak, M.

2014-01-01

276

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

PubMed Central

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

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

2015-01-01

277

Vers une méthode de réglage expérimentale des commandes PID floues : application aux systèmes électromécaniques  

NASA Astrophysics Data System (ADS)

Electrical and electromechanical systems have to satisfy to more and more constrained specifications. Therefore, non-linear control structures must be spread out. Among them, fuzzy logic control can be one interessant and performant alternative. The main handicap of this kind of stucture resides in the fact that the tuning parameters are very numerous. In this paper, we first propose an on-site tuning strategy of this set of parameters in the case of a fuzzy proportionnal-integrative controller based on the experimental designs methodology and on a limited number of pre-defined closed-loop experiments. Then, a complete set of predetermined parameters for a fuzzy proportionnal-integrative-derivative controller will be given. These parameters have been optimized on a specified benchmark according to an IAE criterion. They are calculated like the Ziegler-Nichols or Broïda methodology on conventional controllers; that is, using a single open-loop step response to obtain a model of a first-order plus delay transfert function. Validity limits for this method are provided. Les systèmes électriques ou électromécaniques doivent satisfaire à des spécifications de plus en plus contraignantes qui nécessitent la mise au point de structures de commande non linéaires. Parmi celles-ci, la commande par logique floue constitue une alternative intéressante et performante. Son principal handicap réside dans le nombre très important de paramètres à régler. Dans cet article, nous nous proposons de systématiser ces réglages dans deux cas de figure. Tout d'abord nous utiliserons la méthodologie des plans d'expérimentations pour effectuer un réglage sur site d'un contrôleur flou de type proportionnel-intégral. Ce réglage sera obtenu en ne réalisant qu'un nombre limité d'essais expérimentaux en boucle fermée avec des combinaisons prédéfinies des paramètres à régler. La combinaison optimale de ces paramètres au sens d'un critère de type IAE (Intégrale de la valeur Absolue de l'Erreur) sera déduite de l'exploitation des résultats des essais. Dans un deuxième temps, nous proposerons des réglages prédéfinis et optimisés (au sens du même critère) d'un contrôleur flou de type proportionnel-intégral-dérivé. Ces réglages préétablis ne nécessiteront qu'un seul essai d'identification du système à contrôler en boucle ouverte et peuvent donc se rapprocher des méthodologies classiques et éprouvées de réglage sur site que constituent les réglages de Ziegler-Nichols ou de Broïda pour des contrôleurs conventionnels. Dans cet article, les jeux de paramètres préétablis que nous fournirons seront valables pour des systèmes dont la réponse indicielle en boucle ouverte est modélisable sous la forme d'une fonction de transfert du premier ordre plus un retard pur. Les limites de validité de cette méthode seront précisées.

Maussion, P.; Hissel, D.

1998-08-01

278

Couches minces d'oxynitrure de phosphore. Application aux structures MIS sur InP  

E-print Network

We present a technique for the preparation of stable, homogeneous and moisture insensitive oxynitride phosphorus films. They were fabricated directly from PON solid sample ; this technique allows for deposition- istics of MIS structures show an hysteresis at high frequency of only 0.20 V for 33 nm thick oxynitride

Paris-Sud XI, Université de

279

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

E-print Network

the hottest sections of gas turbine engines features an interesting answer to problems introduced achieved. This research empha- sizes clearly that the critical point is the development of a coating which the trial phase on engines. REVUE DE PHYSIQUE APPLIQUÃ?E TOME 5, JUIN 1970, PAGE 1. Introduction. - La

Boyer, Edmond

280

Groupes quantiques associes aux courbes rationnelles et elliptiques et leurs applications  

NASA Astrophysics Data System (ADS)

The thesis was defended by the author in University of Angers (France). It consists of four parts. The fist part (in French) is introductory and is devoted to relation between quantum groups, integrable systems and statistical models. In the second part (in English) the transition function of the periodic Toda chain is interpreted in terms of the formalism of rational Lax operators. In the third part (in French) one compares two elliptic quantum groups and one conclude that they belong to two different bialgebra categories. The fourth part (in English) contains a construction of the partition function of the SOS model in terms of the projections of an elliptic quantum group.

Silantyev, A.

2009-01-01

281

Contr^ole des equations aux derivees partielles aspects theorique et  

E-print Network

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

d'Orléans, Université

282

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

PubMed Central

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

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

2014-01-01

283

Loi constitutive chimioplastique pour le beton expose aux hautes temperatures  

NASA Astrophysics Data System (ADS)

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

Hammoud, Rabah

284

Morphological variations in AuxSiy nanostructures under variable pressure and annealing conditions  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

285

Subnanometer-Resolution Frequency Modulation Atomic Force Microscopy in Liquid for Biological Applications  

NASA Astrophysics Data System (ADS)

The spatial resolution and force sensitivity of frequency modulation atomic force microscopy (FM-AFM) in liquid have been dramatically improved in the last a few years. It is now possible to image individual atoms and molecules at a solid/liquid interface with a subnanometer-scale resolution and a piconewton-order loading force. This capability enabled the direct visualization of hydration layers and mobile ions on a lipid bilayer and ?-strands constituting an amyloid fibril. These striking results highlighted the significant potential of FM-AFM in biological research. Here, I summarize the technological innovation that brought about this progress and review biological applications of FM-AFM in liquid.

Fukuma, Takeshi

2009-08-01

286

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

E-print Network

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

Paris-Sud XI, Université de

287

Une Application Industrielle d'Extraction de l'Information pour l'Intelligence Economique  

E-print Network

Une Application Industrielle d'Extraction de l'Information pour l'Intelligence Economique Buschbeck corpus. Le but est de fournir aux PMI locales des informations marketing sur les produits, les the results with examples taken from real-life competitive intelligence applications. MOTS-CLÃ?S : fouille de

Paris-Sud XI, Université de

288

Metalophilic interaction in gold halide: quantum chemical study of AuX (X?=?F-At).  

PubMed

Quantum chemical calculations of the structures, stabilities, and metalophilic interactions of AuX halides (X?=?F-At) at the CCSD(T) theoretical level with extended basis sets were performed. Natural bond orbital analysis showed that the present gold-halide metalophilic interactions mainly resulted from the overlap of an sp hybrid on halogen and a 6s6p5d hybrid on the Au atom. Analysis of electron density deformation showed a pronounced charge accumulation in the middle of the region between heavier X and Au, and clearly suggested the formation of covalent bond. Topological analysis of the Laplacian and total electronic energy densities at bond critical points showed the "intermediate type" character of gold-halide metalophilic interactions. Electron localization function showed the increased covalency from X?=?F to X?=?At. PMID:24590459

Li, Xinying

2014-05-01

289

Functional expression and characterization of Arabidopsis ABCB, AUX 1 and PIN auxin transporters in Schizosaccharomyces pombe.  

PubMed

Heterologous expression systems based on tobacco BY-2 cells, Arabidopsis cell cultures, Xenopus oocytes, Saccharomyces cerevisiae, and human HeLa cells have been used to express and characterize PIN, ABCB (PGP), and AUX/LAX auxin transporters from Arabidopsis. However, no single system has been identified that can be used for effective comparative analyses of these proteins. We have developed an accessible Schizosaccharomyces pombe system for comparative studies of plant transport proteins. The system includes knockout mutants in all ABC and putative auxin transport genes and Gateway((R))-compatible expression vectors for functional analysis and subcellular localization of recombinant proteins. We expressed Arabidopsis ABCB1 and ABCB19 in mam1pdr1 host lines under the inducible nmt41 promoter. ABCB19 showed a higher (3)H-IAA export activity than ABCB1. Arabidopsis PIN proteins were expressed in a mutant lacking the auxin effluxer like 1 (AEL1) gene. PIN1 showed higher activity than PIN2 with similar protein expression levels. Expression of AUX1 in a permease-deficient vat3 mutant resulted in increased net auxin uptake activity. Finally, ABCB4 expressed in mam1pdr1 displayed a concentration-dependent reversal of (3)H-IAA transport that is consistent with its observed activity in planta. Structural modelling suggests that ABCB4 has three substrate interaction sites rather than the two found in ABCB19, thus providing a rationale for the observed substrate activation. Taken together, these results suggest that the S. pombe system described here can be employed for comparative analyses and subsequent structural characterizations of plant transport proteins. PMID:19309458

Yang, Haibing; Murphy, Angus S

2009-07-01

290

Application  

Cancer.gov

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

291

Rsultats des lections aux C.A.P. de l'IRD -Scrutin du 23 octobre 2008 C.A.P. N 1 : Directeurs de recherche  

E-print Network

Résultats des élections aux C.A.P. de l'IRD - Scrutin du 23 octobre 2008 C.A.P. N° 1 : Directeurs-François AGNESE (FSU) Odile HOFFMANN 45 #12;Résultats des élections aux C.A.P. de l'IRD - Scrutin du 23 octobre 2008 C.A.P. N° 1 : Directeurs de recherche Nombre de Sièges à pourvoir (NS) : DR0 = 1 (pas de

292

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

293

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

E-print Network

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

Paris-Sud XI, Université de

294

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. PMID:23986770

Golan, Guy; Betzer, Rotem; Wolf, Shmuel

2013-01-01

295

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

E-print Network

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

Paris-Sud XI, Université de

296

Second International Conference on Late Roman Coarse Wares; Aix-en-Provence, 2005 (Actes paratre aux British Archaeological Reports)  

E-print Network

paraître aux British Archaeological Reports) Les céramiques communes de l'Antiquité tardive en Gaule désormais bien connues et régulièrement attestées sur de nombreux sites, c'est aussi du Nord que provient début du VIIIe s. sur quelques sites portuaires, essentiellement à Marseille, l'équipement domestique

Paris-Sud XI, Université de

297

Le Lay Y.-F.1 2008. "Le Mississippi d'Elise Reclus : donner du sens aux eaux  

E-print Network

1 Le Lay Y.-F.1 2008. "Le Mississippi d'Elisée Reclus : donner du sens aux eaux courantes". Cahiers Louisiane approximativement deux ans et est fasciné par le Mississippi. En 1854, celui-ci est en cours d-clés : Elisée Reclus, Mississippi, fleuve, eau, histoire, aménagement, imaginaire Abstract Reclus resided

Paris-Sud XI, Université de

298

Etude du dopage de l'arsniure de gallium par la technique d'pitaxie en phase vapeur aux organomtalliques  

E-print Network

405 Etude du dopage de l'arséniure de gallium par la technique d'épitaxie en phase vapeur aux 14 avril 1982) Résumé. 2014 Des couches d'arséniure de gallium épitaxiées par la technique de. Abstract. 2014 The doping of gallium arsenide layers grown by the trimethylgallium/arsine method has been

Paris-Sud XI, Université de

299

Mecanismo(s) de Acción de los Herbicidas Auxínicos - Parte 2 - Nivel Avanzado  

NSDL National Science Digital Library

Descripción:El control selectivo de malezas de hoja ancha en cultivos de cereales por los herbicidas auxínicos ha hecho de éstos una de las familias de herbicidas actualmente en uso mas ampliamente distribuidas e importantes. Se cree que estos herbicidas actúan como simuladores hormonales. En esta lección se detallará la relación estructural y fisiológica entre los herbicidas auxínicos y la fitohormona natural auxina (ácido indol-3-acético; IAA por sus siglas en inglés) y se explicarán los mecanismos bioquímicos que pueden estar involucrados en su modo de acción. Se revisará el mecanismo de transporte de célula a célula y la absorción de las auxinas por las células, así como también la forma en que estas moléculas causan elongación celular e inducen la síntesis de etileno. De igual forma, se describirán los receptores, las rutas de transferencia de señales y los cambios en expresión genética inducidos por la fitohormona natural IAA y su relación con la actividad de los herbicidas auxínicos.

300

Application  

Microsoft Academic Search

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

Michael Ströbel

301

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

302

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

E-print Network

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

Ligozat, Anne-Laure

303

Pour une cartographie des parties prenantes fonde sur leur engagement : une application  

E-print Network

157 Pour une cartographie des parties prenantes fondée sur leur engagement : une application aux'entreprise. Appliqué au sociétariat d'une banque mutualiste française nouvelle cartographie peut aider ses dirigeants l'intérêt d'établir une cartographie des parties prenantes en fonction de leur engagement à l

Paris-Sud XI, Université de

304

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

PubMed Central

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

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

2013-01-01

305

Electrofiltration: An Energy Efficient Alternative in Solid-Liquid Separations  

E-print Network

Electrofiltration has established itself as an energy efficient unit operation in ultrafine particle dewatering. The Dorr-Oliver Electrofilter combines vacuum cake filtration with electrophoresis and electroosmosis. This results in an order...

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

1984-01-01

306

-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

307

Continuous or catastrophic solid-liquid transition in jammed systems  

NASA Astrophysics Data System (ADS)

Pasty materials encountered in industry and in earth science are intermediate between solids and liquids either in terms of their internal structure (disordered but jammed) or from a mechanical point of view. Our results indicate that the apparent behavior of a particulate system (soils, suspensions, clays, etc.) can range from liquid-like to soil or solid-like depending on the relative importance of the energy supplied to it and its "state of jamming" which evolves in time, and the transition from one state to another may appear either continuous or catastrophic.

Coussot, P.; Roussel, N.; Jarny, S.; Chanson, H.

2005-01-01

308

Supersonic air flow due to solid-liquid impact.  

PubMed

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 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. PMID:20366598

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

2010-01-15

309

Removal of trace heavy metals by solid?liquid separation  

Microsoft Academic Search

Highly sensitive and economical methods have been developed for the removal of trace heavy metal ions such as Cr(III), Fe(III), Co(II), Ni(II), Cu(II), Ru(III), Rh(III), Pd(II), Os(VIII), Ir(III) and Pt(IV), present in a large aqueous volume by absorption of their Phenanthrenequinone Monoximes (PQM) chelates on microcrystalline naphthalene in different pH ranges in a fluidized bed reactor. The above metal?PQM chelates

S. A. Wasay; B. K. Puri

1993-01-01

310

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

PubMed

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

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

2012-07-19

311

Manifold to uniformly distribute a solid-liquid slurry  

DOEpatents

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

Kern, Kenneth C. (Lake Hiawatha, NJ)

1983-01-01

312

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

PubMed

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

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

2014-08-01

313

Contribution aux Methodes Analytiques des Substances a L'aide de Faisceaux de Particules Chargees  

NASA Astrophysics Data System (ADS)

Nous avons vu les possibilites d'analyse par particules chargees des aerosols recueillis sur des filtres de type MILLIPORE. La meme technique a ete utilisee pour des filtres ayant servi a la filtration de l'eau du fleuve Saint-laurent. Deux techniques ont ete utilisees: (1) FAST (Forward Alpha Scattering Technique): pour analyser l'hydrogene, le carbone, l'oxygene et puis l'azote. Des alpha de 12 MeV ont ete utilises. (2) PIXE (Particle Induced X-ray Emission): pour analyser les elements moyens et lourds, dans ce cas des protons de 3 MeV ainsi que des ions d'argon de 1 et 1.6 MeV ont ete utilises. Les etudes ont montre que sous vide, la majorite des problemes proviennent des dommages causes par l'echauffement du a l'impact du faisceau sur le filtre. L'analyse quantitative par l'intermediaire du faisceau extrait peut presenter des difficultes en ce qui concerne les elements legers pour lesquels l'absorption des rayonnements caracteristiques dans l'atmosphere externe est importante. Les ions lourds se pretent mal aux analyses des aerosols du fait de leur limite de sensibilite. L'analyse directe de liquides par des protons est particulierement interessante puisqu'elle ne necessite aucune preparation prealable des echantillons. A cet effet, un programme de calcul de concentration des elements dans la solution a analyser a ete mis au point. Nous avons determine la limite de sensibilite de la methode PIXE pour les cibles minces (filtre) et pour le cas ou la matrice est de l'eau. Enfin, la technique FAST peut etre un complement de la technique PIXE.

Saidi, Abdelmajid

314

Evaluating auxin distribution in tomato (Solanum lycopersicum) through an analysis of the PIN and AUX/LAX gene families.  

PubMed

The temporal and spatial control of auxin distribution has a key role in the regulation of plant growth and development, and much has been learnt about the mechanisms that influence auxin pools and gradients in vegetative tissues, particularly in Arabidopsis. For example polar auxin transport, mediated by PIN and AUX/LAX proteins, is central to the control of auxin distribution. In contrast, very little information is known about the dynamics of auxin distribution and the molecular basis of its transport within and between fruit tissues, despite the fact that auxin regulates many aspects of fruit development, which include fruit formation, expansion, ripening and abscission. In addition, functional information regarding the key regulators of auxin fluxes during both vegetative and reproductive development in species other than Arabidopsis is scarce. To address these issues, we have investigated the spatiotemporal distribution of auxin during tomato (Solanum lycopersicum) fruit development and the function of the PIN and AUX/LAX gene families. Differential concentrations of auxin become apparent during early fruit growth, with auxin levels being higher in internal tissues than in the fruit pericarp and the pattern of auxin accumulation depended on polar transport. Ten tomato PIN (SlPIN1 to 10) and five AUX/LAX (SlLAX1 to 5) genes were identified and found to display heterogeneous expression patterns, with tissue and developmental-stage specificity. RNAi-mediated co-silencing of SlPIN4 and SlPIN3 did not affect fruit development, which suggested functional redundancy of PIN proteins, but did lead to a vegetative phenotype, and revealed a role for these genes in the regulation of tomato shoot architecture. PMID:22211518

Pattison, Richard J; Catalá, Carmen

2012-05-01

315

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

PubMed Central

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

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

2014-01-01

316

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

NASA Astrophysics Data System (ADS)

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

Wu, Guang Jun

317

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

E-print Network

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

Paris-Sud XI, Université de

318

Ecologie des transferts de contaminants dans les réseaux trophiques: application à Echinococcus multilocularis et aux éléments trace métalliques.  

E-print Network

??Il est maintenant établi que les changements anthropiques d'utilisation des terres (déforestation, irrigation, agriculture ...), les modifications de la biodiversité et les changements climatiques sont… (more)

Raoul, Francis

2013-01-01

319

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

320

Etude de l'endommagement de structures composites matrice thermoplastique : application aux rservoirs de stockage hyperbare de  

E-print Network

réservoirs de stockage hyperbare de l'hydrogène Study of damages on thermoplastic composite structures - 91003 EVRY CEDEX e-mail : jacques.renard@ensmp.fr Résumé Le stockage de l'hydrogène est un verrou développement de réservoirs de stockage haute pression de type IV (liner polymère renforcé d'une structuration

Paris-Sud XI, Université de

321

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

322

Diffusion acceleree apres irradiation aux neutrons A 20K dans les alliages Fe-Co et Fe-Co-X (X = Mn, V, Ti)  

Microsoft Academic Search

Plusieurs alliages de type B2: Fe 50 at %—Co 50 at %, Fe 49 at %—Co 49 at %—X 2 at % (X = Mn, V, Ti) ont été irradiés aux neutrons de fission (E > 1 MeV) à la temperature de l'hydrogène liquide. Les recuits isochrones de l'excès de résistivité produit montrent que dans tous les alliages étudiés, la

J. P. Riviere; J. F. Dinhut; J. C. Desoyer

1981-01-01

323

Voies molculaires dans le cancer du rein : de la biologie aux traitements de demain Signalling pathways in renal cell carcinoma: from the molecular biology to the futur  

E-print Network

1 Voies moléculaires dans le cancer du rein : de la biologie aux traitements de demain Signalling pathways in renal cell carcinoma: from the molecular biology to the futur therapy Julien Edeline (1 Manuscrit auteur, publié dans "Bulletin du cancer 2010;97:5-15" DOI : 10.1684/bdc.2010.1066 #12;2 Résumé

Paris-Sud XI, Université de

324

The French Tsunami warning center for the Mediterranean and North-East Atlantic (CENtre d'ALerte aux Tsunamis, CENALT)  

NASA Astrophysics Data System (ADS)

The CENALT (CENtre d'Alerte aux Tsunamis) is responsible for the French NTWC (National Tsunami Warning Center). This center was established through a project that was requested by the French Ministry of Interior and the Ministry of Sustainable Development. It is implemented by the Commissariat à l'énergie atomique et aux énergies alternatives (CEA), the French Hydrographic and Oceanographic Service (SHOM) and the Centre National de la Recherche Scientifique (CNRS), and is based in Bruyères-le-Châtel (30 km from Paris). This center is based on three main components: seismic network data, sea level network data, dissemination system and processing and analyzing softwares and is operating on a 24/7 basis. The CENALT has established scientific cooperation with 8 institutions and implemented and funded private leased lines to exchange data with institutions from 5 different European countries (Germany, Italy, Portugal, Spain, Tunisia). The seismic data are processed with the Seiscomp 3 software. SHOM is working on making all French tide-gauge stations operated and available in real-time in 2012, and they installed 5 new tide gage stations. The tide gage data will be processed with a customized version of the Guitar (Gempa) software allowing the detection of tsunami signals, complemented by other softwares developed by the CEA. Historical tsunami databases (sources and observations) and earthquake databases, mostly based on available international databases, have been synthetized by CEA to produce information maps in real time, used to guide operators of permanence. Precomputed tsunami scenarios are implemented to build in real time maps of the highest tsunami impact expected in deep water. Along with an optimized tsunami modeling tool, these softwares help to define the areas where the tsunami may be observed and cause damage. The CENALT has been operating since early January 2012 as a pre-operational service and will be fully operational in July 2012. It is also ready to act as Candidate Watch Provider covering Western Mediterranean by July 2012.

Schindelé, F.; Bossu, R.; Alabrune, N.; Arnoul, P.; Duperray, P.; Gailler, A.; Guilbert, J.; Hébert, H.; Hernandez, B.; Loevenbruck, A.; Roudil, P.

2012-04-01

325

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. PMID:22645571

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

2012-01-01

326

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

327

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

PubMed

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

Feilberg, Anders; Bildsoe, Pernille; Nyord, Tavs

2015-01-01

328

http://u-sports.univ-fcomte.fr Jeudi 15 Election du Directeur de l'Upfr Sports -Conformment aux statuts de l'Upfr  

E-print Network

«promotion des sports» jeudi 29 nuit du handball à partir de 18 h - salle 1 et grande halle Sports Cohttp://u-sports.univ-fcomte.fr M A R S l'Act' Jeudi 15 Election du Directeur de l'Upfr Sports - Conformément aux statuts de l'Upfr Sports, seuls les enseignants-chercheurs, les enseignants ou les chercheurs

Jeanjean, Louis

329

Les cycles de l'interaction pour l'accs aux connaissances en sciences de l'information et de la communication :l'exemple du dispositif FORSIC.  

E-print Network

Les cycles de l'interaction pour l'accès aux connaissances en sciences de l'information et de la communication :l'exemple du dispositif FORSIC. Auteurs : Ertzscheid Olivier : doctorant en Sciences de l'Information Sciences Sociales de Toulouse 1. Link-Pezet Jo : Maître de Conférence en Sciences de l'Information et de la

Paris-Sud XI, Université de

330

Proposition de stage M2 thorique Sujet : Les phonons de cisaillement et leur couplage aux lectrons dans une bi-couche  

E-print Network

Proposition de stage M2 théorique Sujet : Les phonons de cisaillement et leur couplage aux électrons dans une bi-couche de graphène Lieu de stage : LPMMC, Grenoble Encadrant : Denis BASKO Contact déplacement. Le premier but du stage est donc de déterminer l'Hamiltonien effectif du couplage électron

van Tiggelen, Bart

331

Faites des sciences et Dcouvrez les technologies... aux activits parallles ! Institut Zoologique, quai Van Beneden, 22 -4020 Lige -un seul lieu, une exposition interactive  

E-print Network

Faites des sciences et Découvrez les technologies... aux activités parallèles ! Institut Zoologique consommées actuellement :le pavot (Papaver somniferum L.), le chanvre (Cannabis sativa L.), le CocaLundi 28 mars Activités sur réservation. Inscrivez-vous via le formulaire sur notre site web : www.ulg.ac.be/sciences

Liège, Université de

332

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

E-print Network

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

Paris-Sud XI, Université de

333

Recent advances in vacuum sciences and applications  

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

334

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

PubMed Central

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

2015-01-01

335

Extremely high density of magnetic excitations at T =0 in YbCu5 -xAux  

NASA Astrophysics Data System (ADS)

Structural, magnetic, transport, and thermal properties of YbCu5 -xAux alloys with Au concentration between x =0.4 (at the stability limit of AuBe5-type structure) and x =0.7 are reported. The outstanding features of this system are (i) the constant and record high value of Cm/T ?6.7 J/mol K2 below a characteristic temperature T* (ranging between 150 mK and 350 mK), (ii) a power law of temperature dependence Cm/T (T >T*) =g /Tq , with q ranging between 1.3 and 0.95 for decreasing x from 0.7 to 0.5, and (iii) an observation of incoherent electronic scattering in the resistivity at T <1 K for x ?0.6 despite the fact that Yb magnetic atoms are placed in an ordered lattice. Geometric frustration, originating from the tetrahedral distribution of Yb atoms, appears to be responsible for the lack of magnetic order and the exotic behavior of this system.

?urlík, I.; Giovannini, M.; Sereni, J. G.; Zapotoková, M.; Gabáni, S.; Reiffers, M.

2014-12-01

336

Application of electro acoustics for dewatering pharmaceutical sludge  

SciTech Connect

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

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

1992-02-01

337

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

338

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

NASA Astrophysics Data System (ADS)

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

Meunier, Mathieu

339

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

NASA Astrophysics Data System (ADS)

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

Canciu, Vintila

340

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

NASA Technical Reports Server (NTRS)

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

Barker, R. E., Jr.

1986-01-01

341

Mecanismo(s) de Acción de las Auxinas y los Herbicidas Auxínicos - Parte 1- Introducción  

NSDL National Science Digital Library

Descripción:El control selectivo de malezas de hoja ancha en cultivos de cereales utilizando herbicidas auxínicos ha hecho de éstos una de las familias de herbicidas actualmente en uso más ampliamente distribuidas e importantes. Estos herbicidas fueron los primeros herbicidas orgánicos desarrollados que presentaron selectividad; es decir, capaces de matar un cierto grupo de plantas sin afectar a otros grupos (por ejemplo: matar plantas de hoja ancha pero no las de hoja angosta; en este documento se utilizará el término "gramíneas" para referirse a las plantas de hoja angosta o cereales). En esta lección se presentarán las principales características de los herbicidas auxínicos, se discutirán sus principales usos y se describirán los síntomas de daño que causan. De igual forma, se indicará la forma en que estos herbicidas matan a las plantas sensibles.

342

Coordination polymer gels with important environmental and biological applications.  

PubMed

Coordination Polymer Gels (CPGs) constitute a subset of solid-like metal ion and bridging organic ligand structures (similar to metal-organic frameworks) that form multi-dimensional networks through a trapped solvent as a result of non-covalent interactions. While physical properties of these gels are similar to conventional high molecular weight organic polymer gels, coordination polymer gel systems are often fully reversible and can be assembled and disassembled in the presence of additional energy (heat, sonication, shaking) to give a solution of solvated gelators. Compared to gels resulting from purely organic self-assembled low molecular weight gelators, metal ions incorporated into the fibrilar networks spanning the bulk solvent can impart CPGs with added functionalities. The solid/liquid nature of the gels allows for species to migrate through the gel system and interact with metals, ligands, and the solvent. Chemosensing, catalysis, fluorescence, and drug-delivery applications are some of the many potential uses for these dynamic systems, taking advantage of the metal ion's coordination, the organic polydentate ligand's orientation and functionality, or a combination of these properties. By fine tuning these systems through metal ion and ligand selection and by directing self-assembly with external stimuli the rational synthesis of practical systems can be envisaged. PMID:23192282

Jung, Jong Hwa; Lee, Ji Ha; Silverman, Julian R; John, George

2013-02-01

343

Résistance aux antituberculeux  

Microsoft Academic Search

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

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

2005-01-01

344

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

EPA Science Inventory

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

345

Application of digital image analysis for size distribution measurements of microbubbles  

Microsoft Academic Search

This work employs digital image analysis to measure the size distribution of microbubbles generated by the process of electroflotation for use in solid\\/liquid separation processes. Microbubbles are used for separations in the mineral processing industry and also in the treatment of potable water and wastewater.As the bubbles move upward in a solid\\/liquid column due to buoyancy, particles collide with and

S. E. Burns; S. Yiacoumi; D. Frost; C. Tsouris

1997-01-01

346

High-power laser applications in Nippon Steel Corporation  

NASA Astrophysics Data System (ADS)

The laser, which was invented in 1960, has been developed using various substances of solids, liquids, gases and semiconductors as laser active media. Applications of laser utilizing the coherent properties of laser light and the high power density light abound in many industries and in heavy industries respectively. The full-scale use of lasers in the steel industry began nearly 23 years ago with their applications as controllable light sources. Its contribution to the increase in efficiency and quality of the steel making process has been important and brought us the saving of the energy, the resource and the labor. Laser applications in the steel making process generally require high input energy, so it is essential to consider the interaction between the laser beam and the irradiated material. In particular, the reflectivity of the laser beam on the surface of material and the quantity of the laser-induced plasma are critical parameters for high efficient processes with low energy losses. We have developed plenty of new laser systems for the steel making process with their considerations in mind. A review of the following high-power-laser applications is given in the present paper: (1) Use of plasma as a secondary heat source in CO2 laser welding for connecting steel sheets of various grades. (2) Laser-assisted electric resistance welding of pipes. (3) New type all-laser-welded honeycomb panels for high-speed transport. (4) Laser flying welder for continuous hot rolling mill using two 45 kW CO2 lasers.

Minamida, Katsuhiro

2000-02-01

347

Bioinformatic cis-element analyses performed in Arabidopsis and rice disclose bZIP- and MYB-related binding sites as potential AuxRE-coupling elements in auxin-mediated transcription  

PubMed Central

Background In higher plants, a diverse array of developmental and growth-related processes is regulated by the plant hormone auxin. Recent publications have proposed that besides the well-characterized Auxin Response Factors (ARFs) that bind Auxin Response Elements (AuxREs), also members of the bZIP- and MYB-transcription factor (TF) families participate in transcriptional control of auxin-regulated genes via bZIP Response Elements (ZREs) or Myb Response Elements (MREs), respectively. Results Applying a novel bioinformatic algorithm, we demonstrate on a genome-wide scale that singular motifs or composite modules of AuxREs, ZREs, MREs but also of MYC2 related elements are significantly enriched in promoters of auxin-inducible genes. Despite considerable, species-specific differences in the genome structure in terms of the GC content, this enrichment is generally conserved in dicot (Arabidopsis thaliana) and monocot (Oryza sativa) model plants. Moreover, an enrichment of defined composite modules has been observed in selected auxin-related gene families. Consistently, a bipartite module, which encompasses a bZIP-associated G-box Related Element (GRE) and an AuxRE motif, has been found to be highly enriched. Making use of transient reporter studies in protoplasts, these findings were experimentally confirmed, demonstrating that GREs functionally interact with AuxREs in regulating auxin-mediated transcription. Conclusions Using genome-wide bioinformatic analyses, evolutionary conserved motifs have been defined which potentially function as AuxRE-dependent coupling elements to establish auxin-specific expression patterns. Based on these findings, experimental approaches can be designed to broaden our understanding of combinatorial, auxin-controlled gene regulation. PMID:22852874

2012-01-01

348

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

349

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

E-print Network

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

Langewisch, Dustin R

2014-01-01

350

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

E-print Network

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

Papadopoulos, Evangelos

351

Apport de la modélisation pharmacocinétique à l'étude de la variabilité de réponse aux anticorps monoclonaux antitumoraux : application au cetuximab.  

E-print Network

??Les anticorps monoclonaux ont révolutionné le traitement de nombreuses pathologies. Cependant, leur pharmacocinétique (PK) et l’influence de leur concentration sur la réponse clinique restent mal… (more)

Azzopardi, Nicolas

2011-01-01

352

Etude de la forme des impulsions par la methode des moments: Application a la propagation dispersive non-lineaire et aux equations maitresses des lasers tout-fibre  

NASA Astrophysics Data System (ADS)

This thesis is about the propagation of optical pulses in waveguides, such as optical fibers, as the study of the steady-state optical pulses of all-fiber lasers. Pulse propagation in a nonlinear dispersive medium is analyzed in this thesis by the moment method. A clear representation of the moments is developed which enables a better understanding of the underlying physics of the propagation. Assuming that the pulse has a quadratic time-dependent phase, three invariants were found which lead to an analytical solution based on the second order moments. This solution describes both the asymptotic behavior in the normal dispersion regime as well as the periodic behavior in the anomalous dispersion regime. In both cases, the analytical solution is compared to numerous numerical simulations and shows an excellent agreement in the normal dispersion regime. In the anomalous dispersion regime, the analytical solution describes well the qualitative features of the propagation. Linear expressions are then derived from the analytical solution to approximate the nonlinear propagation over short and long distances. The analytical solution assumes that the pulse shape remains invariant along propagation. Two different approaches are then considered to study the evolution of the pulse shape. The first approach looks at the propagation of a gaussian pulse in the normal dispersion regime. Using the linear expressions derived from the analytical solution and the analytical solution of the purely dispersive and nonlinear propagation, the evolution of the pulse envelope is described analytically. Comparison to numerical simulations shows a very good agreement. To go beyond the propagation of a gaussian pulse in the normal dispersion regime, an other approach is needed. The other approach makes use of higher order moments; either the fourth order moments or the nonlinear second order moments (the third order moments being all zero since the pulse is assumed symmetric). In order to solve the moments equations, a model of the phase that goes beyond the quadratic phase approximation is required. Three such different approximate models are studied as well as an approximate representation of the field amplitude based on the Pearson distribution, which can represent several pulse shapes. These different models are compared, on the one hand, to numerical simulations through different moments and, on the other hand, by direct integration ot the approximated system of equations describing the evolution of the moments. A fixed point analysis is also carried out on the equations describing the evolution of the pulse shape. It arises from these analyses that a proper modeling of the phase must consider a dispersive term and a nonlinear term in order to describe the pulse shape evolution. These models are then applied to the more complex problem of the master equations in all-fiber lasers. In these equations, the effects of the different optical elements in the laser cavity are linearized and represented in their differential form. Then, depending on which optical element is present, particular analytical solutions on the complex envelope must be found, if they exist. By using the moments method, a general approach that transforms the master equation into a set of algebraic equations is obtained and studied. The properties of the steady-state pulses obtained from this method are then compared to the analytical solutions on the complex envelope of the master equation in three cases: the actively mode-locked laser, the passively mode-locked laser and the solitonic laser. The comparison shows that the general approach based on the moments yield the same relations between the pulse parameters and cavity parameters and describes the pulse shape within 5%. This approach is then successfully applied to three other master equations where no analytical solution exists. The analytical method developed in this thesis thus enables us to describe the propagation of pulses in a nonlinear dispersive medium in both dispersion regime. It also allows us to study the evol

Burgoyne, Bryan

353

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

E-print Network

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

Boyer, Edmond

354

Douvinet J., Delahaye D., Langlois P., 2010, Cartographies prventives du risque li aux crues rapides dans le nord de la France, in : Foltte J.-C. (dir.), Actes des Neuvimes Rencontres de Tho Quant, Besanon.  

E-print Network

Douvinet J., Delahaye D., Langlois P., 2010, Cartographies préventives du risque lié aux « crues T hé o Q ua nt Besa nç o n, 4 - 6 ma rs 2 0 09 http : //the ma. u niv- fc o mte .f r/ Cartographies M O T S - C L � S R � S U M � Crues rapides Risque Bassin parisien Morphologie Cartographies

Paris-Sud XI, Université de

355

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

356

Quartz Crystal Microbalance Studies of Multilayer Glucagon Fibrillation at the Solid-Liquid Interface  

PubMed Central

We have used a quartz crystal microbalance with dissipation (QCM-D) to monitor the changes in layer thickness and viscoelastic properties accompanying multilayer amyloid deposition in situ for the first time. By means of atomic force microscope imaging, an unequivocal correlation is established between the interfacial nucleation and growth of glucagon fibrils and the QCM-D response. The combination of the two techniques allows us to study the temporal evolution of the interfacial fibrillation process. We have modeled the QCM-D data using an extension to the Kelvin-Voigt viscoelastic model. Three phases were observed in the fibrillation process: 1), a rigid multilayer of glucagon monomers forms and slowly rearranges; 2), this multilayer subsequently evolves into a dramatically more viscoelastic layer, containing a polymorphic network of micrometer-long fibrils growing from multiple nucleation sites; and 3), the fibrillar formation effectively stops as a result of the depletion of bulk-phase monomers, although the process can be continued without a lag phase by subsequent addition of fresh monomers. The robustness of the QCM-D technique, consolidated by complementary atomic force microscope studies, should make it possible to combine different components thought to be involved in the plaque formation process and thus build up realistic models of amyloid plaque formation in vitro. PMID:17513349

Hovgaard, Mads Bruun; Dong, Mingdong; Otzen, Daniel Erik; Besenbacher, Flemming

2007-01-01

357

Thermal modeling with solid/liquid phase change of the thermal energy storage experiment  

NASA Technical Reports Server (NTRS)

A thermal model which simulates combined conduction and phase change characteristics of thermal energy storage (TES) materials is presented. Both the model and results are presented for the purpose of benchmarking the conduction and phase change capabilities of recently developed and unvalidated microgravity TES computer programs. Specifically, operation of TES-1 is simulated. A two-dimensional SINDA85 model of the TES experiment in cylindrical coordinates was constructed. The phase change model accounts for latent heat stored in, or released from, a node undergoing melting and freezing.

Skarda, J. Raymond Lee

1991-01-01

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

On a phase field model for solid-liquid phase transitions  

E-print Network

during solidification) or for liquid-vapor mix- tures (e.g. boiling water), but also for elastic temperature differs from the equilib- rium temperature when the interface is moving or/and is curved des martyrs, F-38054 Grenoble cedex 9, didier.jamet@cea.fr 1 #12;tures (e.g. ice-water or alloys

Sart, Remi

360

Equilibrium calculations of viscosity and thermal conductivity across a solid-liquid interface using boundary fluctuations.  

PubMed

We calculate viscosity and thermal conductivity in systems of Lennard-Jones particles consisting of coexisting solid and liquid with different interface wetting properties using the recently developed equilibrium boundary fluctuation theory. We compare the slip length and equivalent liquid length obtained from these calculations with those obtained from nonequilibrium molecular dynamics. The equilibrium and nonequilibrium calculations of the slip length and the sum of the thermal equivalent lengths are in good agreement. We conclude that for both interfacial properties, the nonequilibrium simulations were probing the linear response. The significant dependence of the intrinsic equivalence length on the interfacial temperature difference used to generate the thermal gradient is explained as a consequence of the different thermodynamic states of the two interfaces. PMID:18500889

Petravic, Janka; Harrowell, Peter

2008-05-21

361

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

362

Optical luminescence studies of the xanthate adsorption layer at the solid-liquid interface  

NASA Astrophysics Data System (ADS)

In this paper, we propose optical luminescence as a method for the evaluation of the kinetics of adsorption processes to calculate the time required to achieve the dynamic balance of the thin layers formed at the mineral-xanthate solution interface. The method is based on the measurement of the intensity for the integral optical radiation obtained from the mineral-xanthate thin layer, which is stimulated with a monochromatic pulsating optical signal, as a function of time. The luminescence was studied for the galena, sphalerite and chalcopyrite minerals with sodium amyl and sodium isobutyl xanthates, for different concentrations of the solutions and different pH values under constant temperature. Using the said method, information was gained on the kinetics of the adsorption of xanthates. Good correlation with the sequential (radiometric) investigation methods was noticed. A better measurement of the time to achieve equilibrium in the formation of the adsorption layer was also obtained.

Todoran, R.; Todoran, D.; Szakács, Zs

2013-11-01

363

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

E-print Network

saturated sand. He concluded from his work that conduction was the predominate beat transfer mechanism for the condition of no net fluid flow through his test samples and that an empirical equation could be devised with which the conductivity of a fluid... and for making available the facilities oi' the Heat Power Group for this investigation. A part of this work was conducted under the American Petroleum Institute Grant In-Aid 43 to B. J. Fluker of the Texas Engineering Experiment Station. Table of Contents...

Dunn, James Elliott

1959-01-01

364

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

365

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

366

ELECTRON TRANSFER MECHANISM AT THE SOLID-LIQUID INTERFACE OF PHYLLOSILICATES  

EPA Science Inventory

Interfacial electron transfer processes on clay minerals have significant impact in natural environments and geochemical systems. Nitrobenzene was used as molecular probes to study the electron transfer mechanism at the solid-water interfaces of Fe-containing phyllosicates. For...

367

A novel method for measuring zeta potentials of solid-liquid interfaces.  

PubMed

A novel method for measuring the zeta potential of PDMS-electrolyte solution interface is presented in this paper. When an electrolyte solution passes the electrode coated with PDMS film, an electrical current will be induced due to the electrostatic potential difference between the PDMS-air interface and the PDMS-electrolyte solution interface. Based on this principle, the relationship between the measured electrical signal and the zeta potential of PDMS-electrolyte solution interface is experimentally investigated. The results show that the magnitude of the measured signal is linearly proportional to this potential difference. An empirical correlation between the zeta potential and the measured voltage signal was obtained. Good agreement was found when comparing the zeta potential calculated by this empirical equation with that reported in the published journal papers. The zeta potential measurement method presented in this paper is simple and accurate and can be used for measuring zeta potentials of other dielectric-electrolyte interfaces. PMID:25467519

Song, Yongxin; Zhao, Kai; Li, Mengqi; Pan, Xinxiang; Li, Dongqing

2015-01-01

368

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

369

Biofilm formation at the solid-liquid and air-liquid interfaces by Acinetobacter species  

Microsoft Academic Search

BACKGROUND: The members of the genus Acinetobacter are Gram-negative cocobacilli that are frequently found in the environment but also in the hospital setting where they have been associated with outbreaks of nosocomial infections. Among them, Acinetobacter baumannii has emerged as the most common pathogenic species involved in hospital-acquired infections. One reason for this emergence may be its persistence in the

Sara Martí; Jesús Rodríguez-Baño; Manuella Catel-Ferreira; Thierry Jouenne; Jordi Vila; Harald Seifert; Emmanuelle Dé

2011-01-01

370

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

SciTech Connect

We present an experimental and numerical study of the transmission of a photonic crystal perforated by two subwavelength slits, separated by two wavelengths.The experimental near-field image of the double-slit design of the photonic crystal shows an interference pattern, which is analogous to Young’s experiment. This interference arises as a consequence of the excitation of surface states of the photonic crystals and agrees very well with the simulations.

Zhang, Lei; Koschny, Thomas; Soukoulis, Costas M.

2012-01-18

371

Diffusion of adsorbed theta-solvent polymers at a solid-liquid interface  

NASA Astrophysics Data System (ADS)

We study how surface diffusion depends on temperature when this is varied below the theta temperature. In the polystyrene-cyclohexane system, we use FRAP (fluorescence recovery after photobleaching) to measure over times over 4 orders of magnitude, from 10 sec to 10^5 seconds. A fast component of motion is attributed to chains loosely bound to the surface. A slower component of motion is retained after rinsing; it is subdiffusive. At temperatures below the bulk coexistence temperature, the surface layer is thicker than a monolayer. We show that bulk phase separation of polymers in dilute solution produces a dense surface layer of emulsion and foamy near-surface structure.

Yu, Changqian; Bae, Sung Chul; Granick, Steve

2012-02-01

372

Time reversal through a solid-liquid interface and super-resolution Chrysoula Tsogka  

E-print Network

-reversal invariance of wave equations can be used to refocus optimally a signal back onto the source that emitted it located in the solid is used to emit the initial wave ¢¤£ . The initial pulse can be either a pressure experiments of Draeger, Cassereau and Fink (Draeger et al., 1998), where ultrasound elastic waves are time

Tsogka, Chrysoula

373

Time reversal through a solid-liquid interface and super-resolution Chrysoula Tsogka  

E-print Network

-reversal invariance of wave equations can be used to refocus optimally a signal back onto the source that emitted it in the solid is used to emit the initial wave UI. The initial pulse can be either a pressure (longitudinal experiments of Draeger, Cassereau and Fink (Draeger et al., 1998), where ultrasound elastic waves are time

Papanicolaou, George C.

374

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

375

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

376

Self-similar microstructural evolution of dendritic solid?liquid mixtures during coarsening  

SciTech Connect

The microstructural evolution of equiaxed dendritic Al-Cu microstructures of two different solid volume fractions (46% and 72%) during isothermal coarsening was studied. We found that the microstructures evolved self-similarly, both morphologically and topologically, while the inverse specific surface area increased as the cube root of time. The differences in scaled morphologies and topologies could be attributed to the difference in solid volume fraction, with the higher volume fraction sample exhibiting a more compact interface shape distribution and a smaller scaled genus.

Fife, J.L.; Voorhees, P.W.; (NWU)

2009-06-12

377

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

Microsoft Academic Search

Tungsten heavy alloys with compositions ranging from 78 to 98 wt pct tungsten were liquid phase sintered at 1507 C under\\u000a microgravity conditions for 120 minutes. The sintered microstructures were quantitatively measured for solid volume fraction,\\u000a grain size, connectivity, and contiguity. Links between these microstructural parameters were analyzed and compared to previously\\u000a derived empirical equations. The macrostructures of the samples

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

1998-01-01

378

Self-aggregation of the SDS surfactant at a solid-liquid interface.  

PubMed

Molecular dynamics simulations of sodium dodecyl sulfate (SDS) molecules on a graphite surface are presented. The simulations were conducted at low and high surface coverage to study aggregation at the water/graphite interface. Results showed that at low surface coverage, the SDS molecules form hemicylindrical aggregates, in agreement with AFM experiments, whereas at high surface coverage, the surfactants form full cylinders. The latter aggregates have not been reported in systems of SDS on hydrophobic substrates, such as graphite. The unexpected results are explained in terms of a water layer adsorbed at the solid surface which was the responsible for the formation of these aggregates. Moreover, the SDS tails in the full cylindrical configuration became straighter than those of the hemicylindrical aggregate. Hydrogen bond formation between water and surfactant head groups was also studied, and it was found that they did not depend on the surfactant concentration. PMID:17394307

Domínguez, Hector

2007-04-26

379

The influence of the solid/liquid interface on the dewetting of ultra thin polymer films  

NASA Astrophysics Data System (ADS)

In recent years, many studies showed that a thin liquid film on a solid surface in air bears more complexity than expected from a simple three-layer-system: e.g. a highly mobile surface layer in case the liquid is an unentangled polystyrene (PS) melt (Yang et al., Science 2010; Seemann et al., J. of Polym. Sci. 2006) or the PS melt can slip over the solid substrate (Baeumchen et al., PRL 2009). Our study focuses on such phenomena and explores their influence on dewetting (speed, morphology, etc.). We use hydrophilic and -phobic Si wafer (either covered by a highly ordered silane layer or by a thin layer of an amorphous fluoropolymer, AF 1600). On each of the substrates, one expects for a certain set of parameters spinodal dewetting for the PS melt. Yet experimentally, a much higher hole density is observed for both types of hydrophobic wafers than is theoretically expected. Moreover, the two hydrophobic coatings induce different dewetting speeds: the PS melt dewets faster on the silane covered Si wafer. The difference is attributed to slip (silane) or to no slip (AF 1600) conditions at the PS/substrate interface, which is also observable in the type of liquid front profile, which in turn changes the dewetting morphology.

Lessel, Matthias; Klos, Mischa; Baeumchen, Oliver; Jacobs, Karin

2012-02-01

380

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

381

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

382

Mathematical Modeling and Numerical Simulation of Liquid-Solid and Solid-Liquid Phase Change  

E-print Network

region) between the solid and liquid phases in which the specific heat, density, thermal conductivity, and latent heat of fusion are continuous and differentiable functions of temperature. In the derivations of the mathematical models we assume the matter...

Joy, Aaron

2013-08-31

383

Equilibrium calculations of viscosity and thermal conductivity across a solid-liquid interface using boundary fluctuations  

NASA Astrophysics Data System (ADS)

We calculate viscosity and thermal conductivity in systems of Lennard-Jones particles consisting of coexisting solid and liquid with different interface wetting properties using the recently developed equilibrium boundary fluctuation theory. We compare the slip length and equivalent liquid length obtained from these calculations with those obtained from nonequilibrium molecular dynamics. The equilibrium and nonequilibrium calculations of the slip length and the sum of the thermal equivalent lengths are in good agreement. We conclude that for both interfacial properties, the nonequilibrium simulations were probing the linear response. The significant dependence of the intrinsic equivalence length on the interfacial temperature difference used to generate the thermal gradient is explained as a consequence of the different thermodynamic states of the two interfaces.

Petravic, Janka; Harrowell, Peter

2008-05-01

384

The equilibrium state of solid-liquid interfaces of aliphatic compounds  

NASA Astrophysics Data System (ADS)

The ordering and orientation of fluid units at interfaces of the aliphatic crystal solution system are the theme of this paper. Based on the idea that the bulk phase and the interfacial phase are two different phases, appropriate relations between the interfacial bond energies and the bulk bond energies are developed by introducing a surface scaling factor Cl. As a description of the interfacial structure of aliphatic compounds, it is assumed that a high degree of ordering is stored in the interfacial fluid phase. Then the so-called ? molecule approach is used to estimate the values of bond energies in the interfacial phase. This leads to the result of Cl?1, meaning that the the interfaces of n-paraffin crystals and the solutions will be extra wetting. This is consistent with the experimental data obtained from the roughening transitions occurring in several n-paraffin-n-hexane solution systems. Finally, a roughening phase transition diagram of the n-C23H48-n-hexane system is presented, which indicates that the roughening temperature of a surface on a crystal is concentration dependent.

Liu, Xiang-Yang; Bennema, P.

1992-09-01

385

Solid–Liquid Separation of Animal Slurry in Theory and Practice  

Microsoft Academic Search

\\u000a Animal slurry contains plant nutrients that are essential for crop production. However, intensive livestock production may\\u000a lead to a surplus of plant nutrients on farms and, as a consequence, discharge or emission to the environment. In order to\\u000a ensure that the slurry applied to fields matches the nutrient requirements of the crops, techniques have been developed to\\u000a reduce the nutrient

Maibritt Hjorth; K. V. Christensen; M. L. Christensen; Sven G. Sommer

386

Solid—liquid separation of animal slurry in theory and practice. A review  

Microsoft Academic Search

Animal slurry contains plant nutrients that are essential for crop production. However, intensive livestock production may\\u000a lead to a surplus of plant nutrients on farms and, as a consequence, discharge or emission to the environment. In order to\\u000a ensure that the slurry applied to fields matches the nutrient requirements of the crops, techniques have been developed to\\u000a reduce the nutrient

M. Hjorth; K. V. Christensen; M. L. Christensen; S. G. Sommer

2010-01-01

387

Elucidating the solid, liquid and gaseous products from batch pyrolysis of cotton-gin trash.  

E-print Network

was considered energy intensive due to the high amount of energy input (6100 kJ) while generating a maximum energy output of only 10%. After disregarding the energy used for preparation and pyrolysis, the energy losses ranged from 30-46% while the energy...

Aquino, Froilan Ludana

2009-05-15

388

Response of a solid-liquid two-phase partitioning bioreactor to transient BTEX loadings.  

PubMed

A two-phase partitioning bioreactor (TPPB) consisting of an aqueous phase containing a bacterial consortium and a polymeric phase of silicone rubber pellets (solid volume fraction 0.1) was used to treat a gaseous waste stream containing benzene, toluene, ethylbenzene and o-xylene (BTEX). The function of the solid polymer phase was to absorb/desorb the gaseous volatile organic compounds providing a buffering effect to protect the cells from high transient loadings and to sequester the BTEX for subsequent degradation. The TPPB was subjected to high and fluctuating inlet loadings of BTEX in the form of 4h step changes of 2, 4, 6 and 10 times the nominal inlet loading of 60 gm(-3) h(-1) total BTEX in approximately equal amounts, and removal efficiencies and elimination capacities were determined. It was found that overall removal efficiencies of greater than 95% can be achieved while obtaining overall elimination capacities of up to 282 gm(-3) h(-1) during transient operation and TPPB operation succumbs to toxic substrate levels between step changes of 6 and 10 times the nominal loading value (360-600 gm(-3) h(-1)). BTEX concentrations in the aqueous phase and the polymer phase of the TPPB were monitored throughout the imposed step changes to determine the extent to which the sequestering phase can buffer the aqueous phase from BTEX. With the polymer phase comprising only 10% of the total working volume of the reactor, the polymer beads accounted for up to 93%, 91% and 70% of the total BTEX present in the working volume for step changes of 2, 4 and 6 times the nominal loading, respectively. PMID:18789478

Littlejohns, Jennifer V; Daugulis, Andrew J

2008-11-01

389

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...

390

Phase-field Models for Solidification and Solid/Liquid Interactions  

E-print Network

of the numerical interfaces used in phase-?eld simulations. To resolve this issue, Kim et al. [5] proposed a new concept for a phase ?eld model that has a di?erent de?ni- tion of solid and liquid composition at a interface. They justi?ed the new approach... proved to be a quite e?ective tool for the simulation of solidi?cation processes. In phase-?eld models, one or more phase ?elds ? (conserved and/or non-conserved) are introduced to describe the microstructure of a complex system. The behavior of a given...

Park, Min Soo

2011-02-22

391

Controlled Crystal Growth and Solid-Liquid Interface in temperature-sensitive colloidal systems  

NASA Astrophysics Data System (ADS)

We use temperature-sensitive colloidal NIPA systems to study crystal growth at the ``atomic scale''. By applying a temperature gradient we are able to control the growth of large colloidal single crystals. We visualize the nucleation of these crystals and solidification at the crystal-liquid interface in three dimensions by using confocal microscopy. Trajectories of particles on both the crystal and liquid side of an advancing interface are determined. These elucidate the mechanism of particle assembly at the interface of a growing crystal. At later stages of crystal growth, the interface becomes stationary, and we use the fluctuations of the stationary interface to determine the interface stiffness. Our data suggests a strong anisotropy of the interface tension. These microscopic observations provide unique insight into the mechanism of solidification.

Nguyen, Duc; Hu, Zhibing; Schall, Peter

2009-03-01

392

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] [Los Alamos National Laboratory

2014-05-02

393

Growth of amorphous silicon nanowires via a solid–liquid–solid mechanism  

Microsoft Academic Search

Amorphous silicon nanowires (a-SiNW) with an average diameter of ca. 20 nm were synthesized at about 950°C under an Ar\\/H2 atmosphere on a large area of a (111) Si substrate without supplying any gaseous or liquid Si sources. The Si substrate, deposited with a layer of Ni (ca. 40 nm thick), served itself as a silicon source for the growth

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

2000-01-01

394

Ultrasonically assisted rapid solid-liquid separation of fine clean coal particles  

Microsoft Academic Search

An investigation on the effects of sonic waves to improve the efficiency of fine coal dewatering in vacuum filtration has been carried out. The objective was to study the synergistic effect of vacuum filtration and sonication in the presence of surface active agents and to understand the importance of the various process parameters to devise scale up criteria for industrial

B. P. Singh

1999-01-01

395

Extension of the broadband single-mode integrated optical waveguide technique to the ultraviolet spectral region and its applications  

PubMed Central

We report here the fabrication, characterization, and application of a single-mode integrated optical waveguide (IOW) spectrometer capable of acquiring optical absorbance spectra of surface-immobilized molecules in the visible and ultraviolet spectral region down to 315 nm. The UV-extension of the single-mode IOW technique to shorter wavelengths was made possible by our development of a low-loss single-mode dielectric waveguide in the UV region based on an alumina film grown by atomic layer deposition (ALD) over a high quality fused silica substrate, and by our design/fabrication of a broadband waveguide coupler formed by an integrated diffraction grating combined with a highly anamorphic optical beam of large numerical aperture. As an application of the developed technology, we report here the surface adsorption process of bacteriochlorophyll a on different interfaces using its Soret absorption band centred at 370 nm. The effects of different chemical compositions at the solid/liquid interface on the adsorption and spectral properties of bacteriochlorophyll a were determined from the polarized UV-Vis IOW spectra acquired with the developed instrumentation. The spectral extension of the single-mode IOW technique into the ultraviolet region is an important advance as it enables extremely sensitive studies in key characteristics of surface molecular processes (e.g., protein unfolding and solvation of aromatic amino-acid groups under surface binding) whose spectral features are mainly located at wavelengths below the visible spectrum. PMID:24466569

Wiederkehr, Rodrigo S.; Mendes, Sergio B.

2014-01-01

396

Extension of the broadband single-mode integrated optical waveguide technique to the ultraviolet spectral region and its applications.  

PubMed

We report here the fabrication, characterization, and application of a single-mode integrated optical waveguide (IOW) spectrometer capable of acquiring optical absorbance spectra of surface-immobilized molecules in the visible and ultraviolet spectral region down to 315 nm. The UV-extension of the single-mode IOW technique to shorter wavelengths was made possible by our development of a low-loss single-mode dielectric waveguide in the UV region based on an alumina film grown by atomic layer deposition (ALD) over a high quality fused silica substrate, and by our design/fabrication of a broadband waveguide coupler formed by an integrated diffraction grating combined with a highly anamorphic optical beam of large numerical aperture. As an application of the developed technology, we report here the surface adsorption process of bacteriochlorophyll a on different interfaces using its Soret absorption band centred at 370 nm. The effects of different chemical compositions at the solid-liquid interface on the adsorption and spectral properties of bacteriochlorophyll a were determined from the polarized UV-Vis IOW spectra acquired with the developed instrumentation. The spectral extension of the single-mode IOW technique into the ultraviolet region is an important advance as it enables extremely sensitive studies in key characteristics of surface molecular processes (e.g., protein unfolding and solvation of aromatic amino-acid groups under surface binding) whose spectral features are mainly located at wavelengths below the visible spectrum. PMID:24466569

Wiederkehr, Rodrigo S; Mendes, Sergio B

2014-03-21

397

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

USGS Publications Warehouse

Rosasco et al. (1975), reported the first successful application of laser-excited Raman spectroscopy for the identification and nondestructive partial analysis of individual solid, liquid, and gaseous phases in selected fluid inclusions. We report here the results of the application of a new instrument, based on back-scattering, that eliminates many of the previous stringent sample limitations and hence greatly expands the range of applicability of Raman spectroscopy to fluid inclusions. Fluid inclusions in many porphyry copper deposits contain 5-10 ??m 'daughter' crystals thought to be anhydrite but too small for identification by the previous Raman technique. Using the new instrument, we have verified that such daughter crystals in quartz from Bingham, Utah, are anhydrite. They may form by leakage of hydrogen causing internal autooxidation of sulfide ion. Daughter crystals were also examined in apatite (Durango, Mexico) and emerald (Muzo, Colombia). Valid analyses of sulfur species in solution in small fluid inclusions from ore deposits would be valuable, but are generally impossible by conventional methods. We present a calibration procedure for analyses for SO42- in such inclusions from Bingham, Utah (12,000 ?? 4000 ppm) and Creede, Colo. (probably < 500 ppm). A fetid Brazilian quartz, originally thought to contain liquid H2S, is shown to contain only HS- in major amounts. ?? 1979.

Rosasco, G.J.; Roedder, E.

1979-01-01

398

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

PubMed Central

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

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

2012-01-01

399

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

PubMed

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

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

2014-10-01

400

Radiation applications research and facilities in AECL research company  

NASA Astrophysics Data System (ADS)

In the 60's and 70's Atomic Energy of Canada had a very active R&D program to discover and develop applications of ionizing radiation. Out of this grew the technology underlying the company's current product line of industrial irradiators. With the commercial success of that product line the company turned its R&D attention to other activities. Presently, widespread interest in the use of radiation for food processing and the possibility of developing reliable and competitive machine sources of radiation hold out the promise of a major increase in industrial use of radiation. While many of the applications being considered are straightforward applications of existing knowledge, others depend on more subtle effects including combined effects of two or more agents. Further research is required in these areas. In March 1985 a new branch, Radiation Applications Research, began operations with the objective of working closely with industry to develop and assist the introduction of new uses of ionizing radiation. The Branch is equipped with appropriate analytical equipment including HPLC (high performance liquid chromatograph) and GC/MS (gas chromatograph/mass spectrometer) as well as a Gammacell 220 and an I-10/1, one kilowatt 10 MeV electron accelerator. The accelerator is located in a specially designed facility equipped for experimental irradiation of test quantities of packaged products as well as solids, liquids and gases in various configurations. A conveyor system moves the packaged products from the receiving area, through a maze, past the electron beam at a controlled rate and finally to the shipping area. Other necessary capabilities, such as gamma and electron dosimetry and a microbiology laboratory, have also been developed. Initial projects in areas ranging from food through environmental and industrial applications have been assessed and the most promising have been selected for further work. As an example, the use of charcoal adsorbent beds to concentrate the components of gas or liquid waste streams requiring treatment is showing promise as a method of significantly reducing the cost of radiation treatment for some effluents. A number of other projects are described.

Iverson, S. L.

401

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

402

Applicability of alkali activated slag-seeded Egyptian Sinai kaolin for the immobilization of 60Co radionuclide  

NASA Astrophysics Data System (ADS)

The present work was established to determine the applicability of local Egyptian kaolinite and blast furnace slag (BFS) as raw materials toward the synthesis of geopolymers and subsequent immobilization of cobalt-60, which is one of the most abundant radionuclides generated in radioactive waste streams in Egypt. XRF, XRD, FT-IR, and SEM techniques were used to characterize the local raw materials and their corresponding alkali activated products. Metakaolin (MK) was obtained by thermal treatment of Egyptian Sinai kaolin 750 °C/4 h. MK and five different BFS content (5, 10, 30, 50 and 80%) were used to synthesize geopolymeric matrices using an alkaline activator of Si-modulus = 1.35 at solid/liquid ratios of 0.8. Compressive strength tests were performed indicating that 50% BFS addition gave the highest values of compressive strength. The IAEA standard leaching tests of cobalt-60 from the solidified waste matrices were carried out. The effective diffusion coefficients of cobalt-60 radionuclides from the solidified waste matrices were calculated to be in the order of 10-14 cm2/s. Leaching of radionuclides was examined to be controlled by the wash-off mechanism with very acceptable values. These results gave encouragement that the tested Egyptian raw materials can be conveniently applied for the synthesis of geopolymers that can be used as a low-cost and high-efficiency materials for the immobilization of radioactive waste.

El-Naggar, M. R.

2014-04-01

403

Remote sensing in environmental police investigations: aerial platforms and an innovative application of thermography to detect several illegal activities.  

PubMed

Being able to identify the environmental crimes and the guilty parties is central to police investigations, and new technologies enable the authorities to do this faster and more accurately than ever before. In recent years, our research team has introduced the use of a range of aerial platforms and an innovative application of thermography to detect several illegal activities; for example, illegal sanitary sewer and storm-drain connections, illicit wastewater discharges, and other "anomalies" on surface waters can be easily identified using their thermal infrared signatures. It can also be used to detect illegal solid/liquid waste dumps or illicit air discharges. This paper introduces first results of a Thermal Pattern and Thermal Tracking approach that can be used to identify different phenomena and several pollutants. The aims of this paper were to introduce a fingerprint paradigm for environmental police investigations, defining several specific signatures (patterns) that permit the identification of an illicit/anomalous activity, and establish a procedure to use this information to find the correlation (tracking) between the crime and the culprit or the source and the target. PMID:25154683

Lega, M; Ferrara, C; Persechino, G; Bishop, P

2014-12-01

404

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

PubMed

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 fu?r 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. PMID:21639532

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

2011-05-01

405

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

406

RE(AuAl2)nAl2(AuxSi1-x)2: a new homologous series of quaternary intermetallics grown from aluminum flux.  

PubMed

The combination of early rare earth metals (La- to Gd and Yb), gold, and silicon in molten aluminum results in the formation of intermetallic compounds with four related structures, forming a new homologous series: RE[AuAl2]nAl2(AuxSi(1-x))2, with x approximately 0.5 for most of the compound and n = 0, 1, 2, and 3. Because of the highly reducing nature of the Al flux, rare earth oxides instead of metals can also be used in these reactions. These compounds grow as large plate-like crystals and have tetragonal structure types that can be viewed as intergrowths of the BaAl4 structure and antifluorite-type AuAl2 layers. REAuAl2Si materials form with the BaAl4 structure type in space group I4/mmm (cell parameters for the La analogue are a = 4.322(2) A, c = 10.750(4) A, and Z = 2). REAu2Al4Si forms in a new ordered superstructure of the KCu4S3 structure type, with space group P4/nmm and cell parameters of the La analogue of a = 6.0973(6) A, c = 8.206(1) A, and Z = 2. REAu3Al6Si forms in a new I4/mmm symmetry structure type with cell parameters of a = 4.2733(7) A, c = 22.582(5) A, and Z = 2 for RE = Eu. The end member of the series, REAu4Al8Si, forms in space group P4/mmm with cell parameters for the Yb analogue of a = 4.2294(4) A, c = 14.422(2) A, and Z = 1. New intergrowth structures containing two different kinds of AuAl2 layers were also observed. The magnetic behavior of all these compounds is derived from the RE ions. Comparison of the susceptibility data for the europium compounds indicates a switch from 3-D magnetic interactions to 2-D interactions as the size of the AuAl2 layer increases. The Yb ions in YbAu(2.91)Al(6)Si(1.09) and YbAu(3.86)Al(8)Si(1.14) are divalent at high temperatures. PMID:18198865

Latturner, Susan E; Kanatzidis, Mercouri G

2008-03-17

407

A novel application of an anaerobic membrane process in wastewater treatment.  

PubMed

The applications of membrane processes in anaerobic biological wastewater treatment still have some limitations due to severe membrane scaling and fouling, although they have been proven to achieve superior COD removal and biomass retention. An innovative anaerobic membrane process for wastewater treatment was conducted to control the membrane scaling problems. The process comprises an anaerobic reactor, an aerobic reactor, and a membrane separation tank. Anaerobic sludge from a full-scale UASB reactor treating food wastewater was inoculated to anaerobic and aerobic reactor to purify synthetic wastewater consisting of glucose and sodium acetate. The anaerobic reactor was operated in a sludge bed type without three-phase separator. The aerobic reactor can eliminate residual organics from the anaerobic reactor effluent using facultative microorganisms. To provide solid-liquid separation, hollow fiber ultrafiltration module was submerged in the separation tank. The results clearly show that the anaerobic membrane process combined methanogenic and aerobic COD reduction is a stable system. No fatal scaling was found after two months of operation even without chemical cleaning for the membrane. It was also found that inorganic precipitates formed in the aerobic reactor were reduced due to CO2 stripping in aerobic reactor. Another important finding was that the inorganic precipitates were entrapped into facultative aerobes floc. The ash/SS ratio of aerobes floc increased from 0.17 to 0.55 after 50 days of operation, which confirms this phenomenon. Based on our investigation, the new process can control scaling effectively to extend the membrane application in anaerobic treatment. PMID:16003960

You, H S; Tseng, C C; Peng, M J; Chang, S H; Chen, Y C; Peng, S H

2005-01-01

408

Aux limites Mardi 15 avril  

E-print Network

conférences, Aix-Marseille Université « Le règne des hommes ou la corruption comme limite du droit dans la, Directeur honoraire des services actifs de la Police Nationale « Les policiers dans la Résistance face au

Chamroukhi, Faicel

409

HYDRODYNAMIQUE ET FLUCTUATIONS AUX INTERFACES  

E-print Network

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.3.1 D´epl´etion de collo¨ides et de polym`eres . . . . . . . . . . . . . . . . . . . 11 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 4.3 Fluctuations d'une interface soumise `a un ´ecoulement de Couette . . . . . . . . 40 4.3.1 Mod

Paris-Sud XI, Université de

410

Applications and Properties of Ionic Liquid- Based Gels and Soft Solid Composites  

NASA Astrophysics Data System (ADS)

Solid-liquid composites (gels) have a combination of properties that afford new material applications in which high solute diffusion is desirable. These composites have a soft-solid mechanical integrity and will not flow under gravity, but entrain a liquid matrix (i.e. 60-98 mass %) which allows for high diffusion and high reactivity. Room temperature ionic liquid (RTILs) are molten organic salts with a melting point below room temperature and negligible vapor pressure. If the RTILs are used as the liquid component of a gel, then the gel matrix will not evaporate (unlike other organic solvents) and may be used for long term applications. This thesis research applies RTIL gels for two new applications; carbon dioxide/nitrogen separation and chemical warfare agent (CWA) barrier and decontamination. Separating CO2 from the flue gas of coal and gas fired power-plants is an increasingly economically and environmentally important gas separation. In this first study, RTIL gels are cast in a supported membrane and gas permeability and ideal selectivity are measured. The RTIL matrix has an inherent affinity for CO2 and provides a high diffusion, hence high permeability (i.e. 500-700 barrer). The solidifying component is a low molecular-weight organic gelator (LMOG) which through physical bonding interactions (i.e. hydrogen bonding, pi-pi stacking and van der Walls forces) forms an entangled network which provides mechanical stability (i.e. increase trans-membrane pressure required to expel selective material from the support). In these studies two LMOGs and five RTILs are used to make supported gel membranes and determine gas permeability and temperature dependent trends. The second application for RTIL gels is a decontaminating barrier for CWAs and toxic industrial compounds (TICs). In these studies a layer of RTIL gel is applied on top of a substrate contaminated with a CWA simulant (i.e. chloroethylethylsulfide, CEES). The gel performs well as a barrier, preventing CEES vapor from penetrating the gel. Simultaneously, the RTIL gel actively decontaminated the substrate by reacting CEES with a sacrificial amine. The RTIL gel barrier was able to decontaminate up to 98% of the CEES applied to a painted steel substrate. Two gel barriers are tested: (1) RTIL gel with a LMOG solidifying agent, and (2) RTIL gel with a polymeric cross-linked network solidifying agent. The polymer gel provided a more mechanically robust barrier, however, the LMOG gel decontaminated at a faster rate. These new applications are but two of many possible applications for RTIL gels. Their negligible vapor pressure affords long term application in ambient conditions and their unique chemistry allows them to be tailored for specific applications.

Voss, Bret Alan McGinness

2011-12-01

411

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

PubMed Central

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

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

2008-01-01

412

Carbon-Based Wear Coatings: Properties and Applications  

NASA Technical Reports Server (NTRS)

The technical function of numerous engineering systems - such as vehicles, machines, and instruments - depends on the processes of motion and on the surface systems. Many processes in nature and technology depend on the motion and dynamic behavior of solids, liquids, and gases. Smart surface systems are essential because of the recent technological push toward higher speeds, loads, and operating temperatures; longer life; lighter weight and smaller size (including nanotechnology); and harsh environments in mechanical, mechatronic, and biomechanical systems. If proper attention is not given to surface systems, then vehicles, machines, instruments, and other technical systems could have short lives, consume excessive energy, experience breakdowns, result in liabilities, and fail to accomplish their missions. Surface systems strongly affect our national economy and our lifestyles. At the NASA Glenn Research Center, we believe that proper attention to surface systems, especially in education, research, and application, could lead to economic savings of between 1.3 and 1.6 percent of the gross domestic product. Wear coatings and surface systems continue to experience rapid growth as new coating and surface engineering technologies are discovered, more cost-effective coating and surface engineering solutions are developed, and marketers aggressively pursue, uncover, and exploit new applications for engineered surface systems in cutting tools and wear components. Wear coatings and smart surface systems have been used widely in industrial, consumer, automotive, aerospace, and biomedical applications. This presentation expresses the author's views of and insights into smart surface systems in wear coatings. A revolution is taking place in carbon science and technology. Diamond, an allotrope of carbon, joins graphite, fullerenes, and nanotubes as its major pure carbon structures. It has a unique combination of extreme properties: hardness and abrasion resistance; adhesion and friction; thermal conductivity; chemical and thermal inertness; corrosion and wear resistance; radiation resistance and biocompatibility; electronic, acoustic, and electrochemical characteristics; and environmental compatibility. These properties make diamond attractive for a wide range of diverse applications. In particular, chemical-vapor-deposited (CVD) diamond coatings offer a broad potential, since size and cost are not as limiting. The production of large, superhard diamond films or sheets at low cost make designer materials possible. This presentation is divided into two sections: properties and applications of hard coatings. The first section is concerned with the fundamental properties of the surfaces of CVD diamonds and related materials. The surface properties of hard coatings with favorable coefficients of friction (less than or equal to 0.1) and dimensional wear coefficients (less than or equal to 10(exp -6) cubic millimeters/N.m) in specific environments are discussed. The second section is devoted to applications. Examples of actual, successful applications and of potential challenging applications of the coatings.such as CVD diamond, diamondlike carbon, and cubic boron nitride-are described. Cutting tools coated with CVD diamond are of immediate commercial interest. Other applications, such as microelectromechanical systems (MEMS), valves, and bearings of CVD diamond, are being developed, but at a slow pace. There is a continually growing interest in commercializing diamondlike carbon for wear parts applications, such as biomedical parts and implants, forming dies, transport guides, magnetic tapes and disks, valves, and gears. Cubic boron nitride films are receiving attention because they can be used on tools to machine ferrous materials or on wear parts in sliding contact with ferrous materials.

Miyoshi, Kazuhisa

2003-01-01

413

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

414

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

415

A new class of room temperature molten salts for battery applications  

Microsoft Academic Search

Salts that are liquid at room temperature would provide a completely ionic electrolyte for rechargeable batteries without the penalty of high operating temperatures. We have discovered and characterized a new class of molten salts that are liquids considerably below room temperature. The new materials are mixtures of dialkyimidazolium chlorides and aluminum chloride. The solid-liquid phase diagram of one member of

J. S. Wilkes; J. A. Levisky; J. S. Landers; R. L. Vaughn; C. L. Hussey; D. A. Floreani; D. J. Stech

1981-01-01

416

Glow Discharge Enhanced Chemical Reaction: Application in Ammonia Synthesis and Hydrocarbon Gas Cleanup  

E-print Network

reforming ........................................................................................ 12 2.1.5 Water gas shift reaction .............................................................................. 13 2.2 Plasma physics... and thus lower the required reaction temperatures and avoid unwanted by-product formation.[9] 2.2 Plasma physics Plasma is described as the fourth state of matter. Unlike solid, liquid and gas, plasma usually character with high energy, chemical...

Ming, Pingjia

2014-06-05

417

Application Bar  

Microsoft Academic Search

\\u000a When you’re ready to program your Windows Phone 7 application in Visual Studio, you’ll know what general features your application\\u000a will provide. Each of the major application features will need to be accessible via a shortcut or some form of a navigation\\u000a menu. For Windows Phone 7 applications, Microsoft recommends that you use a standard Windows Phone 7 Application Bar

Henry Lee; Eugene Chuvyrov

418

L'hélium polarisé : méthodes et applications  

NASA Astrophysics Data System (ADS)

Optical pumping is a method for creating large polarizations of electronic and nuclear spins in a gas of helium 4 and of helium 3. Recently some progress was made in this field with tunable infrared lasers. Nuclear polarizations over 50 % were thus obtained in helium 3 at room temperature. These techniques, combined with low temperature ones, allow polarizing to 50 % a relatively dense gas of helium 3 (n ˜ 10^18 cm-3) at 4 K. These results give a renewed interest to the applications of polarized helium, several of which are discussed in this article : helium magnetometers, NMR gyroscopes, beams of polarized particles extracted from the helium discharges (ions, electrons, metastable atoms, etc...), targets of polarized helium 3 for nuclear physics, helium 3 fuel for controlled fusion reactors and at last potential use of solid metastable helium for energy storage. Le pompage optique est une méthode qui permet d'atteindre de fortes polarisations de spin électronique et nucléaire dans un gaz d'hxA9lium 4 ou d'hélium 3. Récemment des progrès ont été réalisés dans ce domaine grâce aux lasers infrarouges accordables. Des polarisations nucléaires de 50 % et plus ont ainsi été observées dans l'hélium 3 à température ambiante. Ces techniques, combinées avec celle des basses températures, permettent d'obtenir des polarisations d'environ 50 % dans un gaz d'hélium 3 relativement dense (n ˜ 10^18 cm-3) à 4 K. Ces résultats ouvrent des perspectives en ce qui concerne les applications de l'hélium polarisé, dont plusieurs sont discutées dans cet article : magnétomètres à hélium, gyroscopes à RMN, faisceaux de particules polarisées extraits de l'hélium pompé (ions, électrons, métastables, etc...), cibles d'hélium 3 polarisé pour la physique nucléaire, combustible d'hélium 3 pour les réacteurs de fusion contrôlée et enfin utilisation éventuelle de l'hélium solide métastable pour le stockage de l'énergie.

Betts, D. S.; Leduc, M.

419

TESTING OF A ROTARY MICROFILTER TO SUPPORT HANFORD APPLICATIONS  

SciTech Connect

Savannah River National Laboratory (SRNL) researchers are investigating and developing a rotary microfilter for solid-liquid separation applications at the Savannah River Site (SRS). Because of the success of that work, the Hanford Site is evaluating the use of the rotary microfilter for its Supplemental Pretreatment process. The authors performed rotary filter testing with a full-scale, 25-disk unit with 0.5 {micro} filter media manufactured by Pall Corporation using a Hanford AN-105 simulant at solids loadings of 0.06, 0.29, and 1.29 wt%. The conclusions from this testing are: (1) The filter flux at 0.06 wt% solids reached a near constant value at an average of 0.26 gpm/ft{sup 2} (6.25 gpm total). (2) The filter flux at 0.29 wt% solids reached a near constant value at an average of 0.17 gpm/ft{sup 2} (4 gpm total). (3) The filter flux at 1.29 wt% solids reached a near constant value at an average of 0.10 gpm/ft{sup 2} (2.4 gpm total). (4) Because of differences in solids loadings, a direct comparison between crossflow filter flux and rotary filter flux is not possible. The data show the rotary filter produces a higher flux than the crossflow filter, but the improvement is not as large as seen in previous testing. (5) Filtrate turbidity measured < 4 NTU in all samples collected. (6) During production, the filter should be rinsed with filtrate or dilute caustic and drained prior to an extended shutdown to prevent the formation of a layer of settled solids on top of the filter disks. (7) Inspection of the seal faces after {approx} 140 hours of operation showed an expected amount of initial wear, no passing of process fluid through the seal faces, and very little change in the air channeling grooves on the stationary face. (8) Some polishing was observed at the bottom of the shaft bushing. The authors recommend improving the shaft bushing by holding it in place with a locking ring and incorporated grooves to provide additional cooling. (9) The authors recommend that CH2MHill Hanford test other pore size media to determine the optimum pore size for Hanford waste.

Poirier, M; David Herman, D; David Stefanko, D; Samuel Fink, S

2008-06-26

420

Application Bar  

Microsoft Academic Search

\\u000a When you are ready to program your Windows Phone 7 application in Visual Studio, in most cases you will be aware of the general\\u000a features that your application will provide. Each of the major application features will need to be accessible via a shortcut\\u000a or some form of a navigation menu. For Windows Phone 7 applications, Microsoft recommends that you

Henry Lee; Eugene Chuvyrov

421

Introduction Applications  

E-print Network

Introduction Applications Group covers of schemes S3-covers of Schemes Rob Easton May 14, 2007 Rob Easton S3-covers of Schemes #12;Introduction Applications Group covers of schemes Group actions to understand: Rob Easton S3-covers of Schemes #12;Introduction Applications Group covers of schemes Group

Easton, Robert W.

422

Mathmatiques Applications  

E-print Network

Mathématiques et Applications Directeurs de la collection : J. Garnier et V. Perrier 73 For further.zuazua@uam.es MATH�MATIQUES & APPLICATIONS Comité de Lecture 2012­2015/Editorial Board 2012­2015 Directeurs de la collection: J. GARNIER et V. PERRIER #12;Serge Cohen · Jacques Istas Fractional Fields and Applications 123 #12

Istas, Jacques

423

Aminophenyl double decker silsesquioxanes: Spectroscopic elucidation, physical and thermal characterization, and their applications  

NASA Astrophysics Data System (ADS)

The incorporation of cage-like silsesquioxanes (SQ) to form polymers has demonstrated property enhancements in areas such as: thermal and mechanical characteristics, flame retardance, dielectric properties, and oxidative resistance. However, with most hybrid polymers investigated, the attached SQs are pendant with respect to the polymer backbone. A recently developed class of these nano-structured, cage-like silsesquioxanes, formally known as double decker silsesquioxanes (DDSQ), offers the opportunity to form hybrid polymers with SQ cages as a part of the polymer backbone. However, during the capping reaction, these functionalized DDSQs generate cis and trans isomers with respect to the 3D Si-O core. Therefore, it is logical to characterize properties, which will allow for optimization of capping reaction parameters, particularly if one isomer is favored over the other. Moreover, these characteristics are also relevant when reacting or incorporating these isomers, or mixtures thereof, with other molecules to form novel materials. In this dissertation, three aminophenyl DDSQs were synthesized. More specifically, two meta- aminophenyl DDSQs, which were differentiated according to the moiety attached to the D-Si (methyl or cyclohexyl), and one para-aminophenyl DDSQ with a methyl moiety were used. Chemical, physical, and thermal characteristics were evaluated for individual isomers as well as binary mixtures of different cis/trans ratios. The 1H NMR spectra of the cis and trans isomers of these DDSQ had not previously been assigned to a degree that allowed for quantification, which was necessary for these studies. Thus, 1H-29Si HMBC correlations were applied to facilitate 1H spectral assignments and also to confirm previous 29Si assignments. Using 1H NMR not only saves time and material over 29Si NMR, but also provides a more accurate quantification, thus allowing for the ratio of cis and trans isomers present in each compound to be determined. Solubility behavior was investigated for the individual isomers, such that separation techniques could be developed. It was found that cis isomers were 33 times more soluble than trans isomers for para-aminophenyl (R = methyl), and 22 times more soluble for the analogous meta-aminophenyl in a solution of THF and hexanes. For a more sterically hindered meta-aminophenyl (R = cyclohexyl), cis isomers were only 3.5 times more soluble, and the overall solubility was also the lowest. Phase diagrams representing solid-liquid melt equilibria of the binary cis/trans mixtures were developed. Single crystal x-ray diffraction data of isolated isomers helped to interpret the phase behavior. Both compounds with a methyl moiety exhibited eutectic phase diagrams. Their trans isomers were higher melting and exhibited larger packing density. Changing from para- to meta-aminophenyl shifted the solid-liquid equilibrium further from ideal, with decreased activity coefficients. Cyclohexyl DDSQ exhibited an isomorphic phase diagram (a complete solid-solution), attributed to cyclohexyl being more similar in size to the phenyl moieties. A specific application that was chosen for these DDSQ was high performance thermosetting oligoimides. They displayed advantages over their organic counterparts in areas such as the liquid to solid transition and viscosity, which improves the processing window. Additionally, they increased the overall degree of cross-linking leading to improved oxidative stability at elevated temperatures.

Schoen, Beth Whitney

424

Microgravity Science and Applications: Program Tasks and Bibliography for Fiscal Year 1996  

NASA Technical Reports Server (NTRS)

NASA's Microgravity Science and Applications Division (MSAD) sponsors a program that expands the use of space as a laboratory for the study of important physical, chemical, and biochemical processes. The primary objective of the program is to broaden the value and capabilities of human presence in space by exploiting the unique characteristics of the space environment for research. However, since flight opportunities are rare and flight research development is expensive, a vigorous ground-based research program, from which only the best experiments evolve, is critical to the continuing strength of the program. The microgravity environment affords unique characteristics that allow the investigation of phenomena and processes that are difficult or impossible to study an Earth. The ability to control gravitational effects such as buoyancy driven convection, sedimentation, and hydrostatic pressures make it possible to isolate phenomena and make measurements that have significantly greater accuracy than can be achieved in normal gravity. Space flight gives scientists the opportunity to study the fundamental states of physical matter-solids, liquids and gasses-and the forces that affect those states. Because the orbital environment allows the treatment of gravity as a variable, research in microgravity leads to a greater fundamental understanding of the influence of gravity on the world around us. With appropriate emphasis, the results of space experiments lead to both knowledge and technological advances that have direct applications on Earth. Microgravity research also provides the practical knowledge essential to the development of future space systems. The Office of Life and Microgravity Sciences and Applications (OLMSA) is responsible for planning and executing research stimulated by the Agency's broad scientific goals. OLMSA's Microgravity Science and Applications Division (MSAD) is responsible for guiding and focusing a comprehensive program, and currently manages its research and development tasks through five major scientific areas: biotechnology, combustion science, fluid physics, fundamental physics, and materials science. FY 1996 was an important year for MSAD. NASA continued to build a solid research community for the coming space station era. During FY 1996, the NASA Microgravity Research Program continued investigations selected from the 1994 combustion science, fluid physics, and materials science NRAS. MSAD also released a NASA Research Announcement in microgravity biotechnology, with more than 130 proposals received in response. Selection of research for funding is expected in early 1997. The principal investigators chosen from these NRAs will form the core of the MSAD research program at the beginning of the space station era. The third United States Microgravity Payload (USMP-3) and the Life and Microgravity Spacelab (LMS) missions yielded a wealth of microgravity data in FY 1996. The USMP-3 mission included a fluids facility and three solidification furnaces, each designed to examine a different type of crystal growth.

1997-01-01

425

Application of response surface methodology to optimize microwave-assisted extraction of silymarin from milk thistle seeds  

Technology Transfer Automated Retrieval System (TEKTRAN)

Several parameters of Microwave-assisted extraction (MAE) including extraction time, extraction temperature, ethanol concentration and solid-liquid ratio were selected to describe the MAE processing. The silybin content, measured by an UV-Vis spectrophotometry, was considered as the silymarin yield....

426

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

427

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

428

Computer simulation studies of finite-size broadening of solid-liquid interfaces: from hard spheres to nickel  

Microsoft Academic Search

Using molecular dynamics (MD) and Monte Carlo (MC) simulations interfacial properties of crystal-fluid interfaces are investigated for the hard sphere system and the one-component metallic system Ni (the latter modeled by a potential of the embedded atom type). Different local order parameters are considered to obtain order parameter profiles for systems where the crystal phase is in coexistence with the

T. Zykova-Timan; R. E. Rozas; J. Horbach; K. Binder

2009-01-01

429

Correlations between electrical and elastic properties of solid-liquid composites with interfacial energy-controlled equilibrium microstructures  

NASA Astrophysics Data System (ADS)

Electrical conductivity and seismic velocity are studied for plausible pore geometries in the Earth's interior for reliable quantitative analysis of experimental data such as seismic tomography and magnetotelluric explorations. Electrical conductivity of a two-phase system with equilibrium, interfacial energy-controlled phase geometry is calculated for the dihedral angles ? = 40°-100° that are typical for rock-aqueous fluid and ? = 20°-60° for rock-melt systems of lower crust and upper mantle for the case of tetrakaidecahedral grains. Electrical conductivity vs. seismic velocity correlations are acquired by combining of the simulated electrical conductivities with the seismic velocity calculated with the help of equilibrium geometry model Takei [Takei, Y., Effect of pore geometry on VP/ VS: From equilibrium geometry to crack. J. Geophys. Res. 107 (2002): 10.1029/2001JB000522.] for the same pore geometries. The results show that electrical conductivity gradually decreases reaching zero when seismic velocities reach seismic velocities of intact rock for rock-melt systems, while for rock-aqueous fluid systems with ? ? 60° conductivity drops to zero at velocities up to 10% smaller. This can explain the seeming discrepancy of the low seismic velocity region, attributed to the high fluid fraction, and the low electrical conductivity of the same region, which is sometimes faced at collocated electromagnetic and seismic experiments.

Pervukhina, Marina; Kuwahara, Yasuto

2008-01-01

430

Heat transfer enhancement at solid-liquid and solid-gas interfaces by near-surface coolant agitation  

Microsoft Academic Search

Heat transfer enhancement from glass ceramic plate to water or air by agitation of the coolant near the heated surface was investigated. The experimental arrangement consisted of a ceramic plate of dimensions of 47×35×0.26 mm3, attached to a brass vessel with inner dimensions of 34×30×4 mm3. The ceramic plate was provided with a 5×5 mm2 size printed heater on the

Arvi Kruusing; Torsten Thelemann; Heiko Thust; Seppo Leppävuori; Karl-Heinz Drüe

2000-01-01

431

Correlations between electrical and elastic properties of solid-liquid composites with interfacial energy-controlled equilibrium microstructures  

NASA Astrophysics Data System (ADS)

Electrical conductivity and seismic velocity are studied for plausible pore geometries in the Earth's interior for reliable quantitative analysis of experimental data such as seismic tomography and magnetotelluric explorations. Electrical conductivity of a two-phase system with equilibrium, interfacial energy-controlled phase geometry is calculated for the dihedral angles Î&=cedil;40o-100o that are typical for rock-aqueous fluid and Î&=cedil;20o-60o for rock-melt systems of lower crust and upper mantle for the case of tetrakaidecahedral grains. The obtained conductivity is demonstrated to be in agreement with the experimentally measured electrical conductivities of a simple analog material, namely, of open cell metallic foam. Electrical conductivity vs. seismic velocity correlations are acquired by combining of the simulated electrical conductivities with the seismic velocity calculated with the help of equilibrium geometry model Takei (2002) for the same pore geometries. The results show that electrical conductivity gradually decreases reaching zero when seismic velocities reach seismic velocities of intact rock for rock-melt systems, while for rock-aqueous fluid systems with Î&¸acirc;?¥60Ë? conductivity drops to zero at velocities up to 10% smaller. This can explain the seeming discrepancy of the low seismic velocity region, attributed to the high fluid fraction, and the low electrical conductivity of the same region, which is sometimes faced at collocated electromagnetic and seismic experiments. The obtained electrical conductivity - seismic velocity correlations are shown to be practically important for the distinction between melt and aqueous fluid, for the precise definition of liquid fraction, and for the discrimination between regions in hydrostatic equilibrium and those which are subject to strong shear stress or slip process. The analysis on the basis of the calculated conductivity-velocity correlations of experimental electrical conductivity and seismic velocity tomography data allowed clarification the stress state in the region of the deep extension of an active fault. We investigated the area of the deep extension of the Nagamachi-Rifu by analysis of the data of collocated magnetotelluric and seismic velocity tomography results in comparison with the theoretical -V correlations calculated for the equilibrium pore geometry. We suggested equilibrium stress state with the dihedral angles of 60-80Ë? or weakly non-equilibrium stress state in the region located 0-20km to the northwest of M5.0 earthquake at the depth of 10-17 km and in the region extending 0-40km to the northwest of M5.0 at the depth of 18-30km on the basis of the analysis. Present study confirmed the non-equilibrium stress state suggested in the region located 20-40 km to the northwest from the hypocenter of M5.0 earthquake at the depth of 10-17 km. The electrical conductivity and seismic velocities data are shown to be complementary and be useful to clarify the stress state and specify the liquid fraction in the regions. The suggested analysis is demonstrated to be practically important for understanding of stress state in the mid and lower crust and might be applied to all the high resolution data of collocated electromagnetic and seismic experiments. Y. Takei, Effect of pore geometry on Vp/Vs: From equilibrium geometry to crack. J. Geophys. Res. 107 (2002): 10.1029/2001JB000522.

Pervukhina, M.; Kuwahara, Y.

2009-04-01

432

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

433

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

2013-08-01

434

Solid-liquid phase equilibria in the fullerenol-d-CuCl2-H2O system at 25°C  

NASA Astrophysics Data System (ADS)

Solubility in the ternary fullerenol-d-CuCl2-H2O system at 25°C is studied by means of isothermal saturation in ampoules. It is established that the diagram consists of two branches corresponding to the crystallization of fullerenol-d crystallohydrate and copper(II) chloride dihydrate and contains a single non-variant eutonic point corresponding to the reciprocal saturation with both solid phases. The salting-in effect on the crystallization branch of CuCl2 · 2H2O and the salting-out effect on the crystallization branch of fullerenol-d is revealed.

Semenov, K. N.; Kanterman, I. G.; Charykov, N. A.; Murin, I. V.; Kritchenkov, A. S.

2014-06-01

435

Superhydrophobic Photosensitizers. Mechanistic Studies of 1O2 Generation in the Plastron and Solid/Liquid Droplet Interface  

PubMed Central

We describe here a physical-organic study of the first triphasic superhydrophobic sensitizer for photooxidations in water droplets. Control of synthetic parameters enables the mechanistic study of “borderline” two- and three-phase superhydrophobic sensitizer surfaces where 1O2 is generated in compartments that are wetted, partially wetted, or remain dry in the plastron (i.e., air layer beneath the droplet). The superhydrophobic surface is synthesized by partially embedding silicon phthalocyanine (Pc) sensitizing particles to specific locations on polydimethylsiloxane (PDMS) posts printed in a square array (1 mm tall posts on 0.5 mm pitch). In the presence of red light and oxygen, singlet oxygen is formed on the superhydrophobic surface and reacts with 9,10-anthracene dipropionate dianion (1) within a freestanding water droplet to produce an endoperoxide in 54–72% yields. Control of the 1O2 chemistry was achieved by the synthesis of superhydrophobic surfaces enriched with Pc particles either at the PDMS end-tips or at PDMS post bases. Much of the 1O2 that reacts with anthracene 1 in the droplets was generated by the sensitizer “wetted” at the Pc particle/water droplet interface and gave the highest endoperoxide yields. About 20% of the 1O2 can be introduced into the droplet from the plastron. The results indicate that the superhydrophobic sensitizer surface offers a unique system to study 1O2 transfer routes where a balance of gas and liquid contributions of 1O2 is tunable within the same superhydrophobic surface. PMID:24295210

Aebisher, David; Bartusik, Dorota; Liu, Yang; Zhao, Yuanyuan; Barahman, Mark; Xu, QianFeng; Lyons, Alan M.; Greer, Alexander

2014-01-01

436

An MCBJ case study: The influence of ?-conjugation on the single-molecule conductance at a solid/liquid interface  

PubMed Central

Summary ?-Conjugation plays an important role in charge transport through single molecular junctions. We describe in this paper the construction of a mechanically controlled break-junction setup (MCBJ) equipped with a highly sensitive log I–V converter in order to measure ultralow conductances of molecular rods trapped between two gold leads. The current resolution of the setup reaches down to 10 fA. We report single-molecule conductance measurements of an anthracene-based linearly conjugated molecule (AC), of an anthraquinone-based cross-conjugated molecule (AQ), and of a dihydroanthracene-based molecule (AH) with a broken conjugation. The quantitative analysis of complementary current–distance and current–voltage measurements revealed details of the influence of ?-conjugation on the single-molecule conductance. PMID:22043460

Hong, Wenjing; Valkenier, Hennie; Mészáros, Gábor; Manrique, David Zsolt; Mishchenko, Artem; Putz, Alexander; García, Pavel Moreno; Lambert, Colin J; Hummelen, Jan C

2011-01-01

437

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

438

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

439

Solid–liquid separation of faecal sludge using drying beds in Ghana: Implications for nutrient recycling in urban agriculture  

Microsoft Academic Search

This study investigated the possibility of recycling nutrients in human excreta and municipal solid waste for use in agriculture. It reports on the use of drying beds in separating solid and liquid fractions of faecal sludge (FS) so that the solids can be co-composted and the organic matter and part of the nutrients captured for urban agriculture. Sludge influent onto

O. O. Cofie; S. Agbottah; M. Strauss; H. Esseku; A. Montangero; E. Awuah; D. Kone

2006-01-01

440

Solid-Liquid Adsorption of Calcium Phosphate on TiO2 C. C. Chusuei and D. W. Goodman*  

E-print Network

. Justes, K. H. Loh, and E. A. Schweikert Center for Chemical Characterization and Analysis, Department 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 secondaryionmassspectrometry

Goodman, Wayne