Science.gov

Sample records for a-site ionic radius

  1. The Origin of the Ionic-Radius Ratio Rules

    ERIC Educational Resources Information Center

    Jensen, William B.

    2010-01-01

    In response to a reader query, this article traces the origins of the ionic-radius ratio rules and their incorrect attribution to Linus Pauling in the chemical literature and to Victor Goldschmidt in the geochemical literature. In actual fact, the ionic-radius ratio rules were first proposed within the context of the coordination chemistry…

  2. The Origin of the Ionic-Radius Ratio Rules

    ERIC Educational Resources Information Center

    Jensen, William B.

    2010-01-01

    In response to a reader query, this article traces the origins of the ionic-radius ratio rules and their incorrect attribution to Linus Pauling in the chemical literature and to Victor Goldschmidt in the geochemical literature. In actual fact, the ionic-radius ratio rules were first proposed within the context of the coordination chemistry…

  3. Defect association mediated ionic conductivity of rare earth doped nanoceria: Dependency on ionic radius

    NASA Astrophysics Data System (ADS)

    Anirban, Sk.; Sinha, A.; Bandyopadhyay, S.; Dutta, A.

    2016-05-01

    Rare earth doped nanoceria Ce0.9RE0.1O1.95 (RE = Pr, Nd, Eu and Gd) were prepared through citrate auto-ignition method. The single phase cubic fluorite structure with space group Fm3 ¯m of the compositions were confirmed from Rietveld analysis of XRD data. The particle size of the compositions were in the range 49.77 nm to 66.20 nm. An ionic radius dependent lattice parameter variation was found. The DC conductivity of each composition was evaluated using Random Barrier Model. The conductivity decreased and activation energy increased with increasing ionic radius from Gd to Pr doping due to the size mismatch with host ions and formation of stable defect associate. The formation of different defect associates and their correlation with ionic conductivity has been discussed.

  4. Ionic charge, radius, and potential control root/soil concentration ratios of fifty cationic elements in the organic horizon of a beech (Fagus sylvatica) forest podzol.

    PubMed

    Tyler, Germund

    2004-08-15

    The root/organic soil concentration ratio; R/S) of 50 cationic mineral elements was related to their ionic properties, including ionic radius (r), ionic charge (z), and ionic potential (z/r or z2/r). The materials studied were ectomycorrhizal beech (Fagus sylvatica L.) roots and their almost purely organic soil substrate, the O-horizon (mor; raw humus) of a Podzol in South Sweden, developed in a site which has been untouched by forestry or other mechanical disturbance since at least 50 years and located in an area with no local sources of pollution. Elements determined by ICP-AES were aluminium, barium, calcium, iron, potassium, magnesium, manganese, sodium and strontium. Determined by ICP-MS were silver, beryllium, bismuth, cadmium, cerium, cobalt, chromium, caesium, copper, dysprosium, erbium, europium, gallium, gadolinium, hafnium, mercury, holmium, indium, lanthanum, lithium, lutetium, niobium, neodymium, nickel, lead, praseodymium, rubidium, scandium, samarium, tin, terbium, thorium, titanium, thallium, thulium, uranium, vanadium, yttrium, ytterbium, zinc and zirconium. The R/S ratios were most clearly related to the ionic potential of the cationic elements studied, which accounted for approximately 60% of the variability in R/S among elements. The ionic charge of an element was more important than the ionic radius. Elements with high ionic charge had low R/S ratios and vice versa. No clear differences in R/S between essential and non-essential plant nutrients were observed, especially when ions of similar charge were compared.

  5. Effects of Dopant Ionic Radius on Cerium Reduction in Epitaxial Cerium Oxide Thin Films

    DOE PAGES

    Yang, Nan; Orgiani, Pasquale; Di Bartolomeo, Elisabetta; ...

    2017-04-17

    The role of trivalent rare-earth dopants in ceria epitaxial films on surface ion exchange reactivity and ion conductivity has been systematically studied. Single-crystal epitaxial films with unique crystal orientation and micro-structure nature have allowed us to rule out the influence of structural defects on both transport and surface ion exchange properties. The films conductivities were larger than those reported in literature for both polycrystalline ceramic pellets and crystalline films. An increase in oxygen vacancies and Ce3+ concentration while decreasing the dopant ionic radius from La3+ to Yb3+ was observed, thus explaining the measured increased activation energy and enhanced surface reactivity.more » The more significant ability of smaller dopant ionic radius in releasing the stress strength induced by the larger Ce3+ ionic radius allows promoting the formation of oxygen vacancies and Ce3+, which are two precious species in determining the efficiency of ion transport and surface ion exchange processes. This can open new perspectives in designing ceria-based materials in tailoring functional properties, either ion migration or surface reactivity, by rational cation substitutions.« less

  6. Electronic Polarisability of NaNO2-NaNO3 and NaOH-NaNO3 Ionic Melts and Effective Ionic Radius of OH-

    NASA Astrophysics Data System (ADS)

    Iwadate, Yasuhiko; Ohnishi, Ryosuke; Ohkubo, Takahiro

    2017-01-01

    Molar volumes and refractive indexes of molten NaNO2-NaNO3 and NaOH-NaNO3 systems were measured by dilatometry and goniometry, respectively. The molar volumes of both systems increased with increasing temperature. Refractive indexes decreased with a rise of temperature or with increasing wavelength of the incident visible light. Assuming that the electronic polarisability is inherent in an ion, the electronic polarisability of a OH- ion in the melt was estimated from the Lorentz-Lorenz equation to be 1.26×10-30 m3, being comparable with that in the crystal. The effective ionic radius of a OH- ion was evaluated from the obtained electronic polarisability to be 1.34×10-10 m, using the correlation between the third power of the ionic radius and the electronic polarisability of an ion so far reported. The effective ionic radius obtained in this work was in good agreement with that assigned by Shannon.

  7. Trace Element Partitioning under Crustal and Uppermost Mantle Conditions: The Influences of Ionic Radius, Cation Charge, Pressure, and Temperature

    NASA Astrophysics Data System (ADS)

    Wood, B. J.; Blundy, J. D.

    2003-12-01

    The controls on partitioning of trace elements between crystals and silicate melts were initially the subject of crystal-chemical, rather than petrogenetic interest. Goldschmidt (1937) systematized his observations of elemental concentrations in minerals as a means of understanding and predicting element behavior during crystallization from liquids or gases. Thus, he proposed his three "rules" of element partitioning, which may be summarized as follows: (i) Any two ions of the same charge and very similar ionic radius have essentially the same crystal-liquid partition coefficient (D=[i]xtl/[i]liq, where [i] refers to the concentration of element i). (ii) If there is a small difference of ionic radius, the smaller ion enters the crystal preferentially, e.g., DMg2+>DFe2+, DK+>DRb+>DCs+. (iii) For ions of similar radius but different charges, the ion with the higher charge enters the crystal preferentially, i.e., DSc3+>DMg2+>DLi+, DCa2+>DNa+, and DBa2+>DK+. These principles were taught to generations of students and, as we will show below, under certain circumstances, retain a degree of validity. They are neither, however, universally correct nor do they have any quantitative applicability. The aim of this chapter is to summarize the ways in which Goldschmidt's work has been amplified through a combination of theory and experimental measurement in order to quantify crystal-liquid partitioning behavior.Since the development of accurate methods of determining element concentration at the ppm level, the trace-element contents of igneous rocks have frequently been used to model their chemical evolution. These studies use estimated crystal-liquid partition coefficients together with solutions for the differential equations describing, e.g., fractional crystallization or fractional melting (Schilling and Winchester, 1967; Gast, 1968; Shaw, 1970) to model evolution of the melt during precipitation or dissolution of the crystalline phases. Generally, because of lack of data

  8. Relation between the diffusivity, viscosity, and ionic radius of LiCl in water, methanol, and ethylene glycol: a molecular dynamics simulation.

    PubMed

    Kumar, Parveen; Varanasi, Srinivasa R; Yashonath, S

    2013-07-11

    A molecular dynamics (MD) investigation of LiCl in water, methanol, and ethylene glycol (EG) at 298 K is reported. Several structural and dynamical properties of the ions as well as the solvent such as self-diffusivity, radial distribution functions, void and neck distributions, velocity autocorrelation functions, and mean residence times of solvent in the first solvation shell have been computed. The results show that the reciprocal relationship between the self-diffusivity of the ions and the viscosity is valid in almost all solvents with the exception of water. From an analysis of radial distribution functions and coordination numbers the nature of hydrogen bonding within the solvent and its influence on the void and neck distribution becomes evident. It is seen that the solvent−solvent interaction is important in EG while solute−solvent interactions dominate in water and methanol. From Voronoi tessellation, it is seen that the voids and necks within methanol are larger as compared to those within water or EG. On the basis of the void and neck distributions obtained from MD simulations and literature experimental data of limiting ion conductivity for various ions of different sizes, we show that there is a relation between the void and neck radius on the one hand and dependence of conductivity on the ionic radius on the other. It is shown that the presence of large diameter voids and necks in methanol is responsible for maximum in limiting ion conductivity (λ0) of TMA+, while in water and EG, the maximum is seen for Rb+. In the case of monovalent anions, maximum in λ0 as a function ionic radius is seen for Br− in water and EG but for the larger ClO4 − ion in methanol. The relation between the void and neck distribution and the variation in λ0 with ionic radius arises via the Levitation effect which is discussed. These studies show the importance of the solvent structure and the associated void structure.

  9. Large mode radius resonators

    NASA Technical Reports Server (NTRS)

    Harris, Michael R.

    1987-01-01

    Resonator configurations permitting operation with large mode radius while maintaining good transverse mode discrimination are considered. Stable resonators incorporating an intracavity telescope and unstable resonator geometries utilizing an output coupler with a Gaussian reflectivity profile are shown to enable large radius single mode laser operation. Results of heterodyne studies of pulsed CO2 lasers with large (11mm e sup-2 radius) fundamental mode sizes are presented demonstrating minimal frequency sweeping in accordance with the theory of laser-induced medium perturbations.

  10. Effective Cleaning Radius Studies

    SciTech Connect

    Churnetski, B.V.

    2001-10-15

    This report discusses results of testing done in the Savannah River Laboratory half tank and full tank mockup facilities using kaolin clay slurries and the relationship between cleaning radius and pump and slurry characteristics.

  11. The Proton Radius Puzzle

    NASA Astrophysics Data System (ADS)

    Downie, E. J.

    2016-03-01

    The proton radius puzzle is the difference between the proton radius as measured with electron scattering and in the excitation spectrum of atomic hydrogen, and that measured with muonic hydrogen spectroscopy. Since the inception of the proton radius puzzle in 2010 by the measurement of Pohl et al.[1], many possible resolutions to the puzzle have been postulated, but, to date, none has been generally accepted. New data are therefore necessary to resolve the issue. We briefly review the puzzle, the proposed solutions, and the new electron scattering and spectroscopy experiments planned and underway. We then introduce the MUSE experiment, which seeks to resolve the puzzle by simultaneously measuring elastic electron and muon scattering on the proton, in both charge states, thereby providing new information to the puzzle. MUSE addresses issues of two-photon effects, lepton universality and, possibly, new physics, while providing simultaneous form factor, and therefore radius, measurements with both muons and electrons.

  12. Crystal chemistry and the role of ionic radius in rare earth tetrasilicates: Ba2RE2Si4O12F2 (RE = Er(3+)-Lu(3+)) and Ba2RE2Si4O13 (RE = La(3+)-Ho(3+)).

    PubMed

    Fulle, Kyle; Sanjeewa, Liurukara D; McMillen, Colin D; Kolis, Joseph W

    2017-10-01

    Structural variations across a series of barium rare earth (RE) tetrasilicates are studied. Two different formulas are observed, namely those of a new cyclo-silicate fluoride, BaRE2Si4O12F2 (RE = Er(3+)-Lu(3+)) and new compounds in the Ba2RE2Si4O13 (RE = La(3+)-Ho(3+)) family, covering the whole range of ionic radii for the rare earth ions. The Ba2RE2Si4O13 series is further subdivided into two polymorphs, also showing a dependence on rare earth ionic radius (space group P{\\overline 1} for La(3+)-Nd(3+), and space group C2/c for Sm(3+)-Ho(3+)). Two of the structure types identified are based on dinuclear rare earth units that differ in their crystal chemistries, particularly with respect to the role of fluorine as a structural director. The broad study of rare earth ions provides greater insight into understanding structural variations within silicate frameworks and the nature of f-block incorporation in oxyanion frameworks. The single crystals are grown from high-temperature (ca 953 K) hydrothermal fluids, demonstrating the versatility of the technique to access new phases containing recalcitrant rare earth oxides, enabling the study of structural trends.

  13. Variable Radius Nacelle Studies

    NASA Technical Reports Server (NTRS)

    McGowan, David M.

    2001-01-01

    An overview of the active shape control for a variable radius nacelle leading edge program is presented. The current technical plan and schedule will be discussed. Results from the structural shape change of curved plates demonstration will be presented, as well as the NASA LaRC concept for a variable radius nacelle leading edge. Results of a Boeing systems integration study of this concept will be discussed briefly. The status of the sensors, actuators, and computational design tools tasks will also be presented.

  14. Detonation Shock Radius Experiments.

    NASA Astrophysics Data System (ADS)

    Lambert, David; Debes, Joshua; Stewart, Scott; Yoo, Sunhee

    2007-06-01

    A previous passover experiment [1] was designed to create a complex detonation transient used in validating a reduced, asymptotically derived description of detonation shock dynamics (DSD). An underlying question remained on determining the location of the initial detonation shock radius to start the DSD simulation with respect to the dynamical response of the initiation system coupling's to the main charge. This paper concentrates on determining the initial shock radius required of such DSD governed problems. `Cut-back' experiments of PBX-9501 were conducted using an initiation system that sought to optimize the transferred detonation to the desired constant radius, hemispherical shape. Streak camera techniques captured the breakout on three of the prism's surfaces for time-of-arrival data. The paper includes comparisons to simulations using constant volume explosion and high pressure hot spots. The results of the experiments and simulation efforts provide fundamental design considerations for actual explosive systems and verify necessary conditions from which the asymptotic theory of DSD may apply. [1] Lambert, D., Stewart, D. Scott and Yoo, S. and Wescott, B., ``Experimental Validation of Detonation Shock Dynamics in Condensed Explosives. J. of Fluid Mechs., Vol. 546, pp.227-253 (2006).

  15. Antiproton charge radius

    NASA Astrophysics Data System (ADS)

    Crivelli, P.; Cooke, D.; Heiss, M. W.

    2016-09-01

    The upcoming operation of the extra low energy antiprotons ring at CERN, the upgrade of the antiproton decelerator (AD), and the installation in the AD hall of an intense slow positron beam with an expected flux of 1 08 e+ /s will open the possibility for new experiments with antihydrogen (H ¯). Here we propose a scheme to measure the Lamb shift of H ¯. For four months of data taking, we anticipate an uncertainty of 100 ppm. This will provide a test of C P T and the first determination of the antiproton charge radius at the level of 10%.

  16. RADIUS: the government viewpoint

    NASA Astrophysics Data System (ADS)

    Gerson, Donald J.

    1992-04-01

    The Office of Research and Development, with major involvement and support from the Defense Advanced Research Projects Agency (DARPA), has begun a highly applications- oriented project intended to provide image understanding (IU) technology in a fully and semi- automated support system of human-machine interface interactive tools to the photo interpreter and imagery analyst (IA). The central concept of Research and Development for Image Understanding Systems (RADIUS) is that of model supported exploitation. Two- and/or three dimensional site models are developed and/or maintained by analysts using imagery source data, imagery-derived information, and appropriate non-imagery sourced information (often called collateral). IU technology and necessary non-IU technology are used where feasible to integrate this base of information which can be accessed spatially via the now-developed site model and displayed or rendered in support of the IA during the imagery exploitation and reporting process. As new imagery is obtained, it may be registered to the site model, or through the site model to other images, to support the specific exploitation tasks and applications which will be developed. The current effort is the concept definition phase. This phase will determine the viability of current technology to perform these tasks and will define future activities.

  17. Ionic-radius-driven selection of the main-group-metal cage for intermetalloid clusters [Ln@Pbx Bi14-x](q-) and [Ln@Pby Bi13-y](q-) (x/q=7/4, 6/3; y/q=4/4, 3/3).

    PubMed

    Ababei, Rodica; Massa, Werner; Weinert, Bastian; Pollak, Patrik; Xie, Xiulan; Clérac, Rodolphe; Weigend, Florian; Dehnen, Stefanie

    2015-01-02

    Reactions of the binary, pseudo-homoatomic Zintl anion (Pb2 Bi2 )(2-) with Ln(C5 Me4 H)3 (Ln=La, Ce, Nd, Gd, Sm, Tb) in the presence of [2.2.2]crypt in ethane-1,2-diamine/toluene yielded ten [K([2.2.2]crypt)](+) salts of lanthanide-doped semimetal clusters with 13 or 14 surface atoms. Single-crystal X-ray diffraction and energy-dispersive X-ray spectroscopy indicated the presence of the anions [Ln@Pb6 Bi8 ](3-), [Ln@Pb3 Bi10 ](3-), [Ln@Pb7 Bi7 ](4-), or [Ln@Pb4 Bi9 ](4-) in single or double salts; the latter showed various ratios of the components in the solid state. The anions are the first ternary intermetalloid clusters comprising only elements of the sixth period of the periodic table, namely, Pb, Bi and lanthanides. This study, which was complemented by ESI mass spectrometry and (139) La NMR spectroscopy in solution, rationalizes a continuous development of the ratio of 13:14-atom cages with the ionic radius of the embedded Ln(3+) ion, which seems to select the most suitable cage type. Quantum chemical investigations helped to analyze this situation in more detail and to explain the observed subtle influence of the atomic radii. Magnetic measurements confirmed that the embedded Ln(3+) ions keep their expected paramagnetic or diamagnetic nature. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Ionic Blocks

    ERIC Educational Resources Information Center

    Sevcik, Richard S.; Gamble, Rex; Martinez, Elizabet; Schultz, Linda D.; Alexander, Susan V.

    2008-01-01

    "Ionic Blocks" is a teaching tool designed to help middle school students visualize the concepts of ions, ionic compounds, and stoichiometry. It can also assist high school students in reviewing their subject mastery. Three dimensional blocks are used to represent cations and anions, with color indicating charge (positive or negative) and size…

  19. Ionic Blocks

    ERIC Educational Resources Information Center

    Sevcik, Richard S.; Gamble, Rex; Martinez, Elizabet; Schultz, Linda D.; Alexander, Susan V.

    2008-01-01

    "Ionic Blocks" is a teaching tool designed to help middle school students visualize the concepts of ions, ionic compounds, and stoichiometry. It can also assist high school students in reviewing their subject mastery. Three dimensional blocks are used to represent cations and anions, with color indicating charge (positive or negative) and size…

  20. [Fractures of the distal radius].

    PubMed

    Rueger, J M; Hartel, M J; Ruecker, A H; Hoffmann, M

    2014-11-01

    The most prevalent fractures managed by trauma surgeons are those involving the distal radius. The injury occurs in two peaks of prevalence: the first peak around the age of 10 years and the second peak around the age of 60 years. Distal radius fracture management requires sensitive diagnostics and classification. The objectives of treatment are the reconstruction of a pain-free unlimited durable functioning of the wrist and avoidance of typical fracture complications. Non-operative conservative management is generally employed for stable non-displaced fractures of the distal radius with the expectation of a good functional outcome. Unstable comminuted fractures with intra-articular and extra-articular fragment zones are initially set in a closed operation and finally by osteosynthesis. An armament of surgical implants is available for instable fractures requiring fixation. Palmar locked plate osteosynthesis has been established in recent years as the gold standard for operative management of distal radius fractures. Complex Working Group on Osteosynthesis (AO) classification type 3 fractures require extensive preoperative diagnostics to identify and treat typical associated injuries around the wrist.

  1. Radius of gyration and intrinsic viscosity of polyelectrolyte solutions

    SciTech Connect

    Milas, M.; Borsali, R.; Rinaudo, M.

    1993-12-31

    Relatively low molecular weights polyelectrolytes (10{sup 4}-10{sup 6}) behave as worm-like chain when electrostatic repulsions are assumed to govern the excluded volume parameter. Under such conditions, predictions of chain expansion and effect of polyelectrolyte concentrations are made assuming that unperturbed dimensions could be obtained at infinite salt content. Experimental studies of an ionic polysaccharide, namely the Na-hyaluronate, were done and the values obtained for the radius of gyration as well as the intrinsic viscosity at different charge densities are in good agreement with the predictions.

  2. Measurement of solar radius changes

    NASA Technical Reports Server (NTRS)

    Labonte, B. J.; Howard, R.

    1981-01-01

    Results of daily photometric measurements of the solar radius from Mt. Wilson over the past seven years are reported. Reduction of the full disk magnetograms yields a formal error of 0.1 arcsec in the boustrophedonic scans in the 5250.2 A FeI line. 150 scan lines comprise each observation; 1,412 observations were made from 1974-1981. Measurement procedures, determination of the scattered light of the optics and the atmosphere, and error calculations are described, noting that days of poor atmospheric visibility are omitted from the data. The horizontal diameter of the sun remains visually fixed while the vertical component changes due to atmospheric diffraction; error accounting for thermal effects, telescope aberrations, and instrument calibration are discussed, and results, within instrument accuracy, indicate no change in the solar radius over the last seven years.

  3. [Distal radius fractures in children].

    PubMed

    Otayek, S; Ramanoudjame, M; Fitoussi, F

    2016-12-01

    Metaphyseal and physeal fractures of the distal radius are common in children. Most cases are best treated with closed reduction and cast immobilization. Long-term outcomes of these injuries are excellent when specific treatment principles of reduction and casting are followed. Surgical indications are limited and include open fractures, intra-articular fractures, non-reducible fractures, unstable fractures, and the presence of associated nerve injury. Closed reduction and percutaneous pin fixation is the most commonly used surgical option. The clinician should be aware of delayed complications such as growth disturbance of the distal radius, and understand how to manage these problems to ensure successful long-term outcomes. Epiphysiodesis is uncommon but growth plate injuries need to be followed for one year.

  4. Charge radius of the neutrino

    NASA Astrophysics Data System (ADS)

    Bernabéu, J.; Cabral-Rosetti, L. G.; Papavassiliou, J.; Vidal, J.

    2000-12-01

    Using the pinch technique we construct at one-loop order a neutrino charge radius, which is finite, depends neither on the gauge-fixing parameter nor on the gauge-fixing scheme employed, and is process independent. This definition stems solely from an effective proper photon-neutrino one-loop vertex, with no reference to box or self-energy contributions. The role of the WW box in this construction is critically examined. In particular it is shown that the exclusion of the effective WW box from the definition of the neutrino charge radius is not a matter of convention but is in fact dynamically realized when the target fermions are right-handedly polarized. In this way we obtain a unique decomposition of effective self-energies, vertices, and boxes, which separately respect electroweak gauge invariance. We elaborate on the tree-level origin of the mechanism which enforces at the one-loop level massive cancellations among the longitudinal momenta appearing in the Feynman diagrams, and in particular those associated with the non-Abelian character of the theory. Various issues related to the known connection between the pinch technique and the background field method are further clarified. Explicit closed expressions for the neutrino charge radius are reported.

  5. Predictions of Crystal Structure Based on Radius Ratio: How Reliable Are They?

    ERIC Educational Resources Information Center

    Nathan, Lawrence C.

    1985-01-01

    Discussion of crystalline solids in undergraduate curricula often includes the use of radius ratio rules as a method for predicting which type of crystal structure is likely to be adopted by a given ionic compound. Examines this topic, establishing more definitive guidelines for the use and reliability of the rules. (JN)

  6. Predictions of Crystal Structure Based on Radius Ratio: How Reliable Are They?

    ERIC Educational Resources Information Center

    Nathan, Lawrence C.

    1985-01-01

    Discussion of crystalline solids in undergraduate curricula often includes the use of radius ratio rules as a method for predicting which type of crystal structure is likely to be adopted by a given ionic compound. Examines this topic, establishing more definitive guidelines for the use and reliability of the rules. (JN)

  7. Ionic crystals

    SciTech Connect

    Mahan, G.D.

    1985-03-01

    The theme of the second Petra School of Physics was the optical properties of solids. The author's lectures will discuss the theory of ionic crystals such as the alkali halides. The general topics will include a discussion of: the local electric fields, multipole polarizability, core level spectra, and electron energy levels. The subject of alkali halides is today regarded as unfashionable. They were quite popular years ago, but fashions and fancies in science have moved elsewhere. One should not think they are well understood. The author's impression of this field is that activity stopped, not because the problems were solved, but rather because the workers got tired of not being able to solve them. For example, we still do not have a good theory of crystal structure, since microscopic forces are not well characterized. One concludes that other quantities which depend upon forces, such as the elastic constants, are also not well understood, although theories of them are published all of the time. As another example, we still do not have a good theory of bonding. Here there are two camps: one which regards the bonding as ionic, while the other advocates significant amounts of covalency. Recently we have shown that both the elastic constants, and the amount of covalent bonding, depend significantly upon the higher multipole polarizabilities. In summary, the subject of ionic crystals is a field where there are still many unresolved issues awaiting good research. 21 refs., 5 figs., 4 tabs.

  8. Quantized ionic conductance in nanopores

    SciTech Connect

    Zwolak, Michael; Lagerqvist, Johan; Di Ventra, Massimilliano

    2009-01-01

    Ionic transport in nanopores is a fundamentally and technologically important problem in view of its ubiquitous occurrence in biological processes and its impact on DNA sequencing applications. Using microscopic calculations, we show that ion transport may exhibit strong non-liDearities as a function of the pore radius reminiscent of the conductance quantization steps as a function of the transverse cross section of quantum point contacts. In the present case, however, conductance steps originate from the break up of the hydration layers that form around ions in aqueous solution. Once in the pore, the water molecules form wavelike structures due to multiple scattering at the surface of the pore walls and interference with the radial waves around the ion. We discuss these effects as well as the conditions under which the step-like features in the ionic conductance should be experimentally observable.

  9. Radius of curvature controlled mirror

    DOEpatents

    Neil, George R.; Rathke, John Wickham; Schultheiss, Thomas John; Shinn, Michelle D.; Dillon-Townes, Lawrence A.

    2006-01-17

    A controlled radius of curvature mirror assembly comprising: a distortable mirror having a reflective surface and a rear surface; and in descending order from the rear surface; a counter-distortion plate; a flow diverter having a flow diverter aperture at the center thereof; a flow return plate having a flow return aperture at the center thereof; a thermal isolation plate having a thermal isolation plate aperture at the center thereof and a flexible heater having a rear surface and a flexible heater aperture at the center thereof; a double walled tube defining a coolant feed chamber and a coolant return chamber; said coolant feed chamber extending to and through the flow diverter aperture and terminating at the counter-distortion plate and the coolant return chamber extending to and through the thermal isolation backplate and terminating at the flow diverter; and a coolant feed and a coolant return exit at the rear of said flexible heater.

  10. Mirror with thermally controlled radius of curvature

    DOEpatents

    Neil, George R.; Shinn, Michelle D.

    2010-06-22

    A radius of curvature controlled mirror for controlling precisely the focal point of a laser beam or other light beam. The radius of curvature controlled mirror provides nearly spherical distortion of the mirror in response to differential expansion between the front and rear surfaces of the mirror. The radius of curvature controlled mirror compensates for changes in other optical components due to heating or other physical changes. The radius of curvature controlled mirror includes an arrangement for adjusting the temperature of the front surface and separately adjusting the temperature of the rear surface to control the radius of curvature. The temperature adjustment arrangements can include cooling channels within the mirror body or convection of a gas upon the surface of the mirror. A control system controls the differential expansion between the front and rear surfaces to achieve the desired radius of curvature.

  11. Trace element partitioning between ionic crystal and liquid

    NASA Technical Reports Server (NTRS)

    Tsang, T.; Philpotts, J. A.; Yin, L.

    1978-01-01

    The partitioning of trace elements between ionic crystals and the melt has been correlated with lattice energy of the host. The solid-liquid partition coefficient has been expressed in terms of the difference in relative ionic radius of the trace element and the homogeneous and heterogeneous strain of the host lattice. Predictions based on this model appear to be in general agreement with data for alkali nitrates and for rare-earth elements in natural garnet phenocrysts.

  12. Ionic Liquids Database- (ILThermo)

    National Institute of Standards and Technology Data Gateway

    SRD 147 Ionic Liquids Database- (ILThermo) (Web, free access)   IUPAC Ionic Liquids Database, ILThermo, is a free web research tool that allows users worldwide to access an up-to-date data collection from the publications on experimental investigations of thermodynamic, and transport properties of ionic liquids as well as binary and ternary mixtures containing ionic liquids.

  13. Thermotropic Ionic Liquid Crystals

    PubMed Central

    Axenov, Kirill V.; Laschat, Sabine

    2011-01-01

    The last five years’ achievements in the synthesis and investigation of thermotropic ionic liquid crystals are reviewed. The present review describes the mesomorphic properties displayed by organic, as well as metal-containing ionic mesogens. In addition, a short overview on the ionic polymer and self-assembled liquid crystals is given. Potential and actual applications of ionic mesogens are also discussed. PMID:28879986

  14. Puzzling out the proton radius puzzle

    NASA Astrophysics Data System (ADS)

    Mihovilovič, M.; Merkel, H.; Weber, A.

    2016-01-01

    The discrepancy between the proton charge radius extracted from the muonic hydrogen Lamb shift measurement and the best present value obtained from the elastic scattering experiments, remains unexplained and represents a burning problem of today's nuclear physics: after more than 50 years of research the radius of a basic constituent of matter is still not understood. This paper presents a summary of the best existing proton radius measurements, followed by an overview of the possible explanations for the observed inconsistency between the hydrogen and the muonic-hydrogen data. In the last part the upcoming experiments, dedicated to remeasuring the proton radius, are described.

  15. Short radius drilling system improves directional control

    SciTech Connect

    Leazer, C.

    1995-08-01

    Horizontal drilling capabilities and applications have been dramatically increased with development of Becfield Drilling Services` Short Radius Horizontal Drilling System utilizing the Articulated Downhole Drilling Motor (ADM). The system gives precise directional control, predictability , and reliability not previously available in short-radius operations. Because of the unique, patented design of the ADM, the short-radius system can be rotated during lateral drilling operations. This is a significant development in short-radius horizontal drilling technology. This paper reviews the design and operation of this equipment.

  16. Puzzling out the proton radius puzzle

    SciTech Connect

    Mihovilovič, M.; Merkel, H.; Weber, A.

    2016-01-22

    The discrepancy between the proton charge radius extracted from the muonic hydrogen Lamb shift measurement and the best present value obtained from the elastic scattering experiments, remains unexplained and represents a burning problem of today’s nuclear physics: after more than 50 years of research the radius of a basic constituent of matter is still not understood. This paper presents a summary of the best existing proton radius measurements, followed by an overview of the possible explanations for the observed inconsistency between the hydrogen and the muonic-hydrogen data. In the last part the upcoming experiments, dedicated to remeasuring the proton radius, are described.

  17. Structure, ionic conductivity and mobile carrier density in fast ionic conducting chalcogenide glasses

    SciTech Connect

    Yao, Wenlong

    2006-01-01

    This thesis consists of six sections. The first section gives the basic research background on the ionic conduction mechanism in glass, polarization in the glass, and the method of determining the mobile carrier density in glass. The proposed work is also included in this section. The second section is a paper that characterizes the structure of MI + M2S + (0.1 Ga2S3 + 0.9 GeS2) (M = Li, Na, K and Cs) glasses using Raman and IR spectroscopy. Since the ionic radius plays an important role in determining the ionic conductivity in glasses, the glass forming range for the addition of different alkalis into the basic glass forming system 0.1 Ga2S3 + 0.9 GeS2 was studied. The study found that the change of the alkali radius for the same nominal composition causes significant structure change to the glasses. The third section is a paper that investigates the ionic conductivity of MI + M2S + (0.1Ga2S3 + 0.9 GeS2) (M = Li, Na, K and Cs) glasses system. Corresponding to the compositional changes in these fast ionic conducting glasses, the ionic conductivity shows changes due to the induced structural changes. The ionic radius effect on the ionic conductivity in these glasses was investigated. The fourth section is a paper that examines the mobile carrier density based upon the measurements of space charge polarization. For the first time, the charge carrier number density in fast ionic conducting chalcogenide glasses was determined. The experimental impedance data were fitted using equivalent circuits and the obtained parameters were used to determine the mobile carrier density. The influence of mobile carrier density and mobility on the ionic conductivity was separated. The fifth section is a paper that studies the structures of low-alkali-content Na2S + B2S3 (x ≤ 0.2) glasses by neutron and synchrotron x-ray diffraction

  18. Elbow dislocation with ipsilateral distal radius fracture

    PubMed Central

    Meena, Sanjay; Trikha, Vivek; Kumar, Rakesh; Saini, Pramod; Sambharia, Abhishek Kumar

    2013-01-01

    Elbow dislocation associated with ipsilateral distal radius fracture is a rare pattern of injury, although it is common for elbow dislocation and forearm fractures to occur separately. We report a rare case of a 20-year-old male who had a posterior elbow dislocation and ipsilateral distal radius fracture. Elbow dislocation was first reduced in extension and distal radius fracture was then reduced in flexion. Both the injuries were conservatively managed. At 6 months follow-up, the patient had no pain in his elbow and minimal pain in his wrist on heavy lifting and had resumed his work as a laborer. PMID:24082758

  19. Elbow dislocation with ipsilateral distal radius fracture.

    PubMed

    Meena, Sanjay; Trikha, Vivek; Kumar, Rakesh; Saini, Pramod; Sambharia, Abhishek Kumar

    2013-07-01

    Elbow dislocation associated with ipsilateral distal radius fracture is a rare pattern of injury, although it is common for elbow dislocation and forearm fractures to occur separately. We report a rare case of a 20-year-old male who had a posterior elbow dislocation and ipsilateral distal radius fracture. Elbow dislocation was first reduced in extension and distal radius fracture was then reduced in flexion. Both the injuries were conservatively managed. At 6 months follow-up, the patient had no pain in his elbow and minimal pain in his wrist on heavy lifting and had resumed his work as a laborer.

  20. The Thermochemical Stability of Ionic Noble Gas Compounds.

    ERIC Educational Resources Information Center

    Purser, Gordon H.

    1988-01-01

    Presents calculations that suggest stoichiometric, ionic, and noble gas-metal compounds may be stable. Bases calculations on estimated values of electron affinity, anionic radius for the noble gases and for the Born exponents of resulting crystals. Suggests the desirability of experiments designed to prepare compounds containing anionic,…

  1. The Thermochemical Stability of Ionic Noble Gas Compounds.

    ERIC Educational Resources Information Center

    Purser, Gordon H.

    1988-01-01

    Presents calculations that suggest stoichiometric, ionic, and noble gas-metal compounds may be stable. Bases calculations on estimated values of electron affinity, anionic radius for the noble gases and for the Born exponents of resulting crystals. Suggests the desirability of experiments designed to prepare compounds containing anionic,…

  2. Acidic Ionic Liquids.

    PubMed

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition.

  3. Distal radius fractures in the athlete.

    PubMed

    Beleckas, Casey; Calfee, Ryan

    2017-03-01

    Distal radius fractures are one of the most common upper extremity fractures. Athletes with distal radius fractures are treated according to the same principles as non-athletes but present several unique considerations. At all levels of sport, injured athletes desire to return to play as rapidly as possible. Earlier operative fixation may allow an athlete to return to play more quickly. Volar locking plates are most commonly used for operative treatment of distal radius fractures due to their stability and low incidence of complications. Although the majority of distal radius fractures in athletes are treated non-operatively, operative intervention is offered when required to restore and maintain acceptable skeletal alignment. Return to sport is individualized guided by fracture stability, athlete age, and wrist-specific demands for competition.

  4. Mass-radius relationships in icy satellites

    NASA Technical Reports Server (NTRS)

    Lupo, M. J.; Lewis, J. S.

    1979-01-01

    Using published laboratory data for H2O ice, a modeling technique was developed by which the bulk density, density and temperature profile, rotational moment of inertia, central pressure, and location of the rock-ice interface can all be obtained as a function of the radius, the heliocentric distance, and the silicate composition. Models of the interiors of Callisto, Ganymede, Europa, Rhea, and Titan are given, consistent with present mass and radius data. The radius and mass of spheres of ice under self-gravitation for two different temperature classes are given (103 and 77 deg K). Measurements of mass, radius and I/MR2 by spacecraft can be interpreted by this model to yield substantial information about the internal structure and the ice/rock ratio of the icy satellites of Jupiter and Saturn.

  5. Perturbed Radius of Geosynchronous-Satellite Orbit

    NASA Astrophysics Data System (ADS)

    Kawase, Sei-Ichiro

    We analyze theoretically how the radius of geosynchronous orbits would vary owing to the perturbations due to the sun/moon gravity, solar radiation pressure, and the oblate earth. The analysis is simple, as it uses a diagrammatic method to solve near-circular orbital motions. Results are obtained in seven terms of corrections to the radius of non-perturbed ideal orbits. Each correction term is derived, with clear physical meaning, from each component of the perturbing forces.

  6. How to resolve the proton radius puzzle?

    NASA Astrophysics Data System (ADS)

    Paz, Gil

    2016-09-01

    In 2010 the first measurement of the proton charge radius from spectroscopy of muonic hydrogen was found to be five standard deviations away from the regular hydrogen value. Six years later, this ``proton radius puzzle'' is still unresolved. One of the most promising avenues to test the muonic hydrogen result is a new muon-proton scattering experiment called MUSE. We describe how effective field theory methods will allow to directly connect muonic hydrogen spectroscopy to muon-proton scattering.

  7. Solar Radius at Sub-Terahertz Frequencies

    NASA Astrophysics Data System (ADS)

    Menezes, Fabian; Valio, Adriana

    2017-10-01

    The visible surface of the Sun, or photosphere, is defined as the solar radius in the optical spectrum range located at 696,000 km (Cox et al. (Ed. 2015)). However, as the altitude increases, the dominant electromagnetic radiation is emitted at other frequencies. Our aim is to measure the solar radius at frequencies of 212 GHz and 405 GHz through out a solar cycle and, therefore, the altitude where these emissions are generated and that variation along the years. Also we tried to verify the the radius dependence on the solar activity cycle, which can be a good indicator of the changes that occur in the atmosphere structure. For this, we used data obtained by the Submillimetric Solar Telescope (SST) created from daily scans made by SST from 1990 to 2015. From these scans a 2D map of the solar disk was constructed. The solar radius is then determined by adjusting a circumference to the points where the brightness is half of the quiet Sun level, which is set as the most common temperature value in the solar map, i.e., the mode of the temperature distribution. Thus, we determined the solar radius at 212 and 405 GHz and the altitude of the emissions respectively. For 212 GHz, we obtained a radius of 976.5''+/-8'' (707+/-4 Mm), whereas for 405 GHz, we obtained 975.0''+/-8'' (707+/-5 Mm). optical spectrum range

  8. Ionic liquid tunes microemulsion curvature.

    PubMed

    Liu, Liping; Bauduin, Pierre; Zemb, Thomas; Eastoe, Julian; Hao, Jingcheng

    2009-02-17

    Middle-phase microemulsions formed from cationic dioctadecyldimethylammonium chloride (DODMAC), anionic sodium dodecylsulfate (SDS), n-butanol, and n-heptane were studied. An ionic liquid (IL), 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), was employed as the electrolyte in the aqueous media instead of inorganic salts usually used in microemulsion formulation. Studies have been carried out as a function of the concentrations of [bmim][BF4], n-butanol, total surfactant (cDODMAC+SDS), and temperature on the phase behavior and the ultralow interfacial tensions in which the anionic component is present in excess in the catanionic film. Ultralow interfacial tension measurements confirmed the formation of middle-phase microemulsions and the necessary conditions for stabilizing middle-phase microemulsions. Electrical conductivity, small-angle X-ray scattering (SAXS), and small-angle neutron scattering (SANS) experiments were also performed, indicating that the typical heptane domain size has an average radius of 360 A and the ionic liquid induces softening of the charged catanionic film. Most interestingly, the IL concentration (cIL) is shown to act as an effective interfacial curvature-control parameter, representing a new approach to tuning the formulation of microemulsions and emulsions. The results expand the potential uses of ILs but also point to the design of new ILs that may achieve superefficient control over interfacial and self-assembly systems.

  9. Operative treatment of distal radius fractures.

    PubMed

    Vasenius, J

    2008-01-01

    The incidence of distal radius fractures is increasing together with the average age of population. Intra-articular incongruity is the most probable cause of unsatisfactory outcome of distal radius fractures in younger and more active patients. Thus, the main goal in the treatment of distal radius fractures should be restoration of articular congruence. A computed tomography (CT) is recommended to help surgeon in preoperative planning in the treatment of comminuted intra-articular fractures. New implants have been designed to provide stable enough fixation for early mobilisation after surgery and to lower rather high complication rates related to conventional fixation methods such as external fixation and dorsal plating. The most common complications related to volar fixed angle plating such as flexor and extensor tendon problems, median nerve neuropathy, and screw diplacement into the radiocarpal joint are surgeon related and are avoidable with proper education. More randomized prospective studies are needed to prove superiority of any fixation method to another.

  10. Mass and radius of cosmic balloons

    NASA Technical Reports Server (NTRS)

    Wang, Yun

    1994-01-01

    Cosmic balloons are spherical domain walls with relativistic particles trapped inside. We derive the exact mass and radius relations for a static cosmic balloon using Gauss-Codazzi equations. The cosmic balloon mass as a function of its radius, M(R), is found to have a functional form similar to that of fermion soliton stars, with a fixed point at 2GM(R)/R approximately or equal to 0.486 which corresponds to the limit of infinite central density. We derive a simple analytical approximation for the mass density of a spherically symmetric relativistic gas star. When applied to the computation of the mass and radius of a cosmic balloon, the analytical approximation yields fairly good agreement with the exact numerical solutions.

  11. A Maximum Radius for Habitable Planets.

    PubMed

    Alibert, Yann

    2015-09-01

    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.

  12. Precision in stitches: Radius Surgical System.

    PubMed

    Waseda, M; Inaki, N; Torres Bermudez, J R; Manukyan, G; Gacek, I A; Schurr, M O; Braun, M; Buess, G F

    2007-11-01

    The Radius Surgical System is a manual manipulator with two additional degrees of freedom compared with conventional laparoscopic instruments (CLIs). This study aimed to compare the performance of laparoscopic suturing tasks with the use of the Radius Surgical System and CLIs, respectively. Five experienced laparoscopic surgeons performed laparoscopic surgical tasks in a training box. The tasks consisted of knot-tying, suturing, and needle control tasks. The needle control task was performed to evaluate the precision of the needle drive by analysis of the needle exit point on a suture pad. In the knot-tying and suturing tasks, required time and accuracy value were measured. Needle control tasks were performed on three different angulations of plane. The angles between the instrument plane and the target plane (AIT) were 30 degrees, 60 degrees, and 90 degrees. The distance of the exit point to the center of the target field, the number of actions needed to fulfill a single task, and the required time were recorded and analyzed. In the knot-tying and frontal suturing tasks, there were no significant differences between the two groups. In the sagittal suturing task, the required time in the Radius group was significantly shorter than in the CLI group. In the needle control tasks on 30 degree and 60 degree AIT, the distance was significantly shorter in the Radius group than in the CLI group. There were no significant differences in the number of actions or the required time. In the frontal and sagittal needle control task on 90 degree AIT, the distance was significantly shorter in the Radius group than in the CLI group. The number of actions and the required time were significantly less in the Radius group than in the CLI group. The two additional degrees of freedom contributed to accurate and controlled needle guidance, especially in difficult spatial situations.

  13. Thermal and structural properties of ionic fluids.

    PubMed

    Bartsch, Hendrik; Dannenmann, Oliver; Bier, Markus

    2015-04-01

    The electrostatic interaction in ionic fluids is well known to give rise to a characteristic phase behavior and structure. Sometimes its long range is proposed to single out the electrostatic potential over other interactions with shorter ranges. Here the importance of the range for the phase behavior and the structure of ionic fluids is investigated by means of grandcanonical Monte Carlo simulations of the lattice restricted primitive model (LRPM). The long-ranged electrostatic interaction is compared to various types of short-ranged potentials obtained by sharp and/or smooth cutoff schemes. Sharply cutoff electrostatic potentials are found to lead to a strong dependence of the phase behavior and the structure on the cutoff radius. However, when combined with a suitable additional smooth cutoff, the short-ranged LRPM is found to exhibit quantitatively the same phase behavior and structure as the conventional long-ranged LRPM. Moreover, the Stillinger-Lovett perfect screening property, which is well known to be generated by the long-ranged electrostatic potential, is also fulfilled by short-ranged LRPMs with smooth cutoffs. By showing that the characteristic phase behavior and structure of ionic fluids can also be found in systems with short-ranged potentials, one can conclude that the decisive property of the electrostatic potential in ionic fluids is not the long range but rather the valency dependence.

  14. Topographic matching of distal radius and proximal fibula articular surface for distal radius osteoarticular reconstruction.

    PubMed

    Zhang, H; Chen, S; Wang, Z; Guo, Y; Liu, B; Tong, D

    2016-07-01

    During osteoarticular reconstruction of the distal radius with the proximal fibula, congruity between the two articular surfaces is an important factor in determining the quality of the outcome. In this study, a three-dimensional model and a coordinate transformation algorithm were developed on computed tomography scanning. Articular surface matching was performed and parameters for the optimal position were determined quantitatively. The mean radii of best-fit spheres of the articular surfaces of the distal radius and proximal fibula were compared quantitatively. The radial inclination and volar tilt following reconstruction by an ipsilateral fibula graft, rather than the contralateral, best resembles the values of the native distal radius. Additionally, the ipsilateral fibula graft reconstructed a larger proportion of the distal radius articular surface than did the contralateral. The ipsilateral proximal fibula graft provides a better match for the reconstruction of the distal radius articular surface than the contralateral, and the optimal position for graft placement is quantitatively determined.

  15. Mass and Radius of Neutron Stars Constrained by Photospheric Radius Expansion X-ray Bursts

    NASA Astrophysics Data System (ADS)

    Kwak, Kyujin; Kim, Myungkuk; Kim, Young-Min; Lee, Chang-Hwan

    Simultaneous measurement of mass and radius of a neutron star is important because it provides strong constraint on the equation of state for nuclear matter inside a neutron star. Type I X-ray Bursts (XRBs) that have been observed in low-mass X-ray binaries sometimes show photospheric radius expansion (PRE). By combining observed fluxes, X-ray spectra, and distances of PRE XRBs and using a statistical analysis, it is possible to simultaneously constrain the mass and radius of a neutron star. However, the mass and radius of a neutron star estimated in this method depends on the opacity of accreted material. We investigate the effect of the opacity on the mass and radius estimation by taking into account the cases that the hydrogen mass fraction of accreted material has narrowly-distributed values. We present preliminary results that are investigated with three different values of hydrogen mass fraction and compare our results with previous studies.

  16. Proton radius from electron scattering data

    NASA Astrophysics Data System (ADS)

    Higinbotham, Douglas W.; Kabir, Al Amin; Lin, Vincent; Meekins, David; Norum, Blaine; Sawatzky, Brad

    2016-05-01

    Background: The proton charge radius extracted from recent muonic hydrogen Lamb shift measurements is significantly smaller than that extracted from atomic hydrogen and electron scattering measurements. The discrepancy has become known as the proton radius puzzle. Purpose: In an attempt to understand the discrepancy, we review high-precision electron scattering results from Mainz, Jefferson Lab, Saskatoon, and Stanford. Methods: We make use of stepwise regression techniques using the F test as well as the Akaike information criterion to systematically determine the predictive variables to use for a given set and range of electron scattering data as well as to provide multivariate error estimates. Results: Starting with the precision, low four-momentum transfer (Q2) data from Mainz (1980) and Saskatoon (1974), we find that a stepwise regression of the Maclaurin series using the F test as well as the Akaike information criterion justify using a linear extrapolation which yields a value for the proton radius that is consistent with the result obtained from muonic hydrogen measurements. Applying the same Maclaurin series and statistical criteria to the 2014 Rosenbluth results on GE from Mainz, we again find that the stepwise regression tends to favor a radius consistent with the muonic hydrogen radius but produces results that are extremely sensitive to the range of data included in the fit. Making use of the high-Q2 data on GE to select functions which extrapolate to high Q2, we find that a Padé (N =M =1 ) statistical model works remarkably well, as does a dipole function with a 0.84 fm radius, GE(Q2) =(1+Q2/0.66 GeV2) -2 . Conclusions: Rigorous applications of stepwise regression techniques and multivariate error estimates result in the extraction of a proton charge radius that is consistent with the muonic hydrogen result of 0.84 fm; either from linear extrapolation of the extremely-low-Q2 data or by use of the Padé approximant for extrapolation using a larger

  17. Proton radius from electron scattering data

    SciTech Connect

    Higinbotham, Douglas W.; Kabir, Al Amin; Lin, Vincent; Meekins, David; Norum, Blaine; Sawatzky, Brad

    2016-05-01

    Background: The proton charge radius extracted from recent muonic hydrogen Lamb shift measurements is significantly smaller than that extracted from atomic hydrogen and electron scattering measurements. The discrepancy has become known as the proton radius puzzle. Purpose: In an attempt to understand the discrepancy, we review high-precision electron scattering results from Mainz, Jefferson Lab, Saskatoon, and Stanford. Methods: We make use of stepwise regression techniques using the F test as well as the Akaike information criterion to systematically determine the predictive variables to use for a given set and range of electron scattering data as well as to provide multivariate error estimates. Results: Starting with the precision, low four-momentum transfer (Q2) data from Mainz (1980) and Saskatoon (1974), we find that a stepwise regression of the Maclaurin series using the F test as well as the Akaike information criterion justify using a linear extrapolation which yields a value for the proton radius that is consistent with the result obtained from muonic hydrogen measurements. Applying the same Maclaurin series and statistical criteria to the 2014 Rosenbluth results on GE from Mainz, we again find that the stepwise regression tends to favor a radius consistent with the muonic hydrogen radius but produces results that are extremely sensitive to the range of data included in the fit. Making use of the high-Q2 data on GE to select functions which extrapolate to high Q2, we find that a Padé (N=M=1) statistical model works remarkably well, as does a dipole function with a 0.84 fm radius, GE(Q2)=(1+Q2/0.66GeV2)−2. Conclusions: Rigorous applications of stepwise regression techniques and multivariate error estimates result in the extraction of a proton charge radius that is consistent with the muonic hydrogen result of 0.84 fm; either from linear extrapolation of the extremely-low-Q2 data or by use of the Padé approximant for extrapolation using a larger range of

  18. MASS-RADIUS RELATIONSHIPS FOR EXOPLANETS

    SciTech Connect

    Swift, D. C.; Eggert, J. H.; Hicks, D. G.; Hamel, S.; Caspersen, K.; Schwegler, E.; Collins, G. W.; Nettelmann, N.; Ackland, G. J.

    2012-01-01

    For planets other than Earth, particularly exoplanets, interpretation of the composition and structure depends largely on comparing the mass and radius with the composition expected given their distance from the parent star. The composition implies a mass-radius relation which relies heavily on equations of state calculated from electronic structure theory and measured experimentally on Earth. We lay out a method for deriving and testing equations of state, and deduce mass-radius and mass-pressure relations for key, relevant materials whose equation of state (EOS) is reasonably well established, and for differentiated Fe/rock. We find that variations in the EOS, such as may arise when extrapolating from low-pressure data, can have significant effects on predicted mass-radius relations and on planetary pressure profiles. The relations are compared with the observed masses and radii of planets and exoplanets, broadly supporting recent inferences about exoplanet structures. Kepler-10b is apparently 'Earth-like', likely with a proportionately larger core than Earth's, nominally 2/3 of the mass of the planet. CoRoT-7b is consistent with a rocky mantle over an Fe-based core which is likely to be proportionately smaller than Earth's. GJ 1214b lies between the mass-radius curves for H{sub 2}O and CH{sub 4}, suggesting an 'icy' composition with a relatively large core or a relatively large proportion of H{sub 2}O. CoRoT-2b is less dense than the hydrogen relation, which could be explained by an anomalously high degree of heating or by higher than assumed atmospheric opacity. HAT-P-2b is slightly denser than the mass-radius relation for hydrogen, suggesting the presence of a significant amount of matter of higher atomic number. CoRoT-3b lies close to the hydrogen relation. The pressure at the center of Kepler-10b is 1.5{sup +1.2}{sub -1.0} TPa. The central pressure in CoRoT-7b is probably close to 0.8 TPa, though may be up to 2 TPa. These pressures are accessible by planar

  19. Modeling of ionic liquids

    NASA Astrophysics Data System (ADS)

    Tatlipinar, Hasan

    2017-02-01

    Ionic liquids are very important entry to industry and technology. Because of their unique properties they may classified as a new class of materials. IL usually classified as a high temperature ionic liquids (HTIL) and room temperature ionic liquids (RTIL). HTIL are molten salts. There are many research studies on molten salts such as recycling, new energy sources, rare elements mining. RTIL recently become very important in daily life industry because of their "green chemistry" properties. As a simple view ionic liquids consist of one positively charged and one negatively charged components. Because of their Coulombic or dispersive interactions the local structure of ionic liquids emerges. In this presentation the local structural properties of the HTIL are discussed via correlation functions and integral equation theories. RTIL are much more difficult to do modeling, but still general consideration for the modeling of the HTIL is valid also for the RTIL.

  20. Thermal Stress of Supported Lipid Bilayer Induces Formation and Collapse of Uniform Radius Tubules

    NASA Astrophysics Data System (ADS)

    Weirich, Kimberly; Fygenson, Deborah

    2011-03-01

    Supported lipid bilayer (SLB) provides a model system in which to quantitatively investigate fluid bilayer transitions from planar to tubular and tubular to spherical morphologies. Following a small increase in temperature, flexible filaments extrude from a fluid SLB. Individual filaments can reach hundreds of microns in length before spontaneously collapsing into discs. We demonstrate that the filaments are tubular and report the effects of lipid composition and flow-induced tension on their properties. At high ionic strength, the sub-resolution tubules are adsorbed to the SLB, enabling the measurement of their radius to within +/- 5 nm using fluorescence microscopy.

  1. The radius and albedo of Hyperion

    NASA Technical Reports Server (NTRS)

    Cruikshank, D. P.

    1979-01-01

    A measurement of the 20-micron thermal flux from Hyperion is reported, and the radius and surface geometric albedo of this outer satellite of Saturn are computed by the photometric/radiometric method. A corrected and normalized 20-micron thermal flux of 0.033 + or - 0.012 Jy is determined. A radius of 112 + or - 15 km and a surface geometric albedo of 0.47 + or - 0.11 are obtained by assuming values of unity for the phase integral, emissivity, and bolometric/visual geometric-albedo ratio. The sensitivity of the photometric/radiometric method to the assumed values of the parameters involved is discussed, and the results are compared with similar studies of Triton. It is concluded that neither Hyperion nor Triton appears to have a geometric albedo in the lower end of the distribution of small bodies in the solar system.

  2. Fractures of Distal Radius: An Overview

    PubMed Central

    Meena, Sanjay; Sharma, Pankaj; Sambharia, Abhishek Kumar; Dawar, Ashok

    2014-01-01

    Fractures of distal radius account for up to 20% of all fractures treated in emergency department. Initial assessment includes a history of mechanism of injury, associated injury and appropriate radiological evaluation. Treatment options include conservative management, internal fixation with pins, bridging and non-bridging external fixation, dorsal or volar plating with/without arthroscopy assistance. However, many questions regarding these fractures remain unanswered and good prospective randomized trials are needed. PMID:25657938

  3. Radicals in ionic liquids.

    PubMed

    Strehmel, Veronika

    2012-05-14

    Stable radicals and recombination of photogenerated lophyl radicals are investigated in ionic liquids. The 2,2,6,6-tetramethylpiperidine-1-yloxyl derivatives contain various substituents at the 4-position to the nitroxyl group, including hydrogen-bond-forming or ionic substituents that undergo additional interactions with the individual ions of the ionic liquids. Some of these spin probes contain similar ions to ionic liquids to avoid counter-ion exchange with the ionic liquid. Depending on the ionic liquid anion, the Stokes-Einstein theory or the Spernol-Gierer-Wirtz theory can be applied to describe the temperature dependence of the average rotational correlation time of the spin probe in the ionic liquids. Furthermore, the spin probes give information about the micropolarity of the ionic liquids. In this context the substituent at the 4-position to the nitroxyl group plays a significant role. Covalent bonding of a spin probe to the imidazolium ion results in bulky spin probes that are strongly immobilized in the ionic liquid. Furthermore, lophyl radical recombination in the dark, which is chosen to understand the dynamics of bimolecular reactions in ionic liquids, shows a slow process at longer timescale and a rise time at a shorter timescale. Although various reactions may contribute to the slower process during lophyl radical recombination, it follows a second-order kinetics that does not clearly show solvent viscosity dependence. However, the rise time, which may be attributed to radical pair formation, increases with increasing solvent viscosity. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. On The Variability Of The Solar Radius

    NASA Astrophysics Data System (ADS)

    Chapman, Gary A.; Dobias, J.

    2007-05-01

    We have examined approximately 18 years of full-disk photometric images of the Sun (1986 through 2004) obtained at the San Fernando Observatory (SFO) looking for variations in the solar radius. The data are from the Cartesian Full Disk Telescope number 1 (CFDT1). This telescope produces images having 512 x 512 pixels with a pixel size of 5.12 arc-sec. We have only used red images obtained at a wavelength of 672.3 nm. Except for infrequent repairs or upgrades, the telescope is seldom modified. Operating at F/40, the focus of the telescope is not routinely adjusted. We have corrected for focal changes due to telescope modifications, differential atmospheric refraction, and temperature changes. We have compared observed image radii with those calculated from the ephemeris. The residuals are then fit by least squares to sinusoids of 10 and 11 year periods to look for a solar cycle signal. For the 11 year period we find that the apparent solar radius is greatest at cycle maximum for solar cycles 22 and 23. The peak-to-peak amplitude is 0.136 +/- 0.010 arc-sec with a multiple regression coefficient, squared, of 0.0404 which is significant at better than p = 0.02 level. The cause of the apparent radius change is under investigation. This work was partially supported by grants from NASA ( NAG5-12905) and NSF (ATM-0533511). Many CSUN students have contributed to this work.

  5. The effective pore radius of screen wicks

    SciTech Connect

    Imura, Hideaki; Kozai, Hiroaki; Ikeda, Yuji

    1994-10-01

    The effective pore radius in screen-wick heat pipes was investigated, which is very important for the prediction of maximum heat transfer rates due to capillary limitation. An equation for the effective pore radius of the screen wicks was derived based on the model of the screen geometry. The capillary height for stainless steel and phosphor bronze screens was measured using water, ethyl alcohol, and Freon 113 as the test liquids. The effect of surface treatment (acid cleaning and oxidation) on the capillary height was also examined. From the comparison of the experimental data for water and ethyl alcohol with those for Freon 113, it was indicated that the contact angle was 24.2{degree} for water and 16.9{degree} for ethyl alcohol. Consequently, it was found that the effective pore radius of the screen wicks could be predicted fairly well from the expression presented in this study, and that the contact angle should be taken into consideration to evaluate the maximum capillary pressure accurately.

  6. Solar radius change between 1925 and 1979

    NASA Technical Reports Server (NTRS)

    Sofia, S.; Dunham, D. W.; Dunham, J. B.; Fiala, A. D.

    1983-01-01

    From an analysis of numerous reports from different locations on the duration of totality of the solar eclipses on January 24, 1925, and February 26, 1979, it is found that the solar radius at the earlier date was 0.5 arcsec (or 375 km) larger than at the later date. The correction to the standard solar radius found for each eclipse is different when different subsets of the observations are used (for example, edge of path of totality timings compared with central timings). This is seen as suggesting the existence of systematic inaccuracies in our knowledge of the lunar figure. The differences between the corrections for both eclipses, however, are very similar for all subsets considered, indicating that changes of the solar size may be reliably inferred despite the existence of the lunar figure errors so long as there is proper consideration of the distribution of the observations. These results are regarded as strong evidence in support of the occurrence of solar radius changes on shorter than evolutionary time scales.

  7. Electrode radius predicts lesion radius during radiofrequency energy heating. Validation of a proposed thermodynamic model

    SciTech Connect

    Haines, D.E.; Watson, D.D.; Verow, A.F. )

    1990-07-01

    Myocardial heating by transcatheter delivery of radiofrequency (RF) energy has been proposed as an effective means of arrhythmia ablation. A thermodynamic model describing the radial temperature gradient at steady state during RF-induced heating is proposed. If one assumes that RF power output is adjusted to maintain a constant electrode-tissue interface temperature at all times, then this thermodynamic model predicts that the radius of the RF-induced lesion will be directly proportional to the electrode radius. A total of 76 RF-induced lesions were created in a model of isolated canine right ventricular free wall perfused and superfused with oxygenated Krebs-Henseleit buffer. Electrode radius was varied between 0.75 and 2.25 mm. RF energy (500 kHz) was delivered for 90 seconds, and the power output was adjusted to maintain a constant electrode-tissue interface temperature of 60 degrees C. A strong linear correlation was observed between electrode radius and lesion radius in two dimensions: transverse (p = 0.0001, r = 0.85) and transmural (p = 0.0001, r = 0.89). With these data, the temperature correlation with irreversible myocardial injury in this model was calculated at 46.6-48.8 degrees C. Therefore, the proposed thermodynamic model closely predicts the observed relation between electrode radius and lesion size during RF myocardial heating.

  8. Magnetoelectric and magnetoelastic properties of easy-plane ferroborates with a small ionic radius

    SciTech Connect

    Kadomtseva, A. M.; Vorob'ev, G. P.; Popov, Yu. F.; Pyatakov, A. P.; Mukhin, A. A.; Ivanov, V. Yu.; Zvezdin, A. K.; Gudim, I. A.; Temerov, V. L.; Bezmaternykh, L. N.

    2012-05-15

    The magnetic, magnetoelectric, and magnetoelastic properties of RFe{sub 3}(BO{sub 3}){sub 4} ferroborates are studied. The measurement of the field dependences of the magnetoelectric polarization along the a axis in holmium ferroborate and in the mixed composition Ho{sub 0.5}Sm{sub 0.5}Fe{sub 3}(BO{sub 3}){sub 4} revealed the following dependences for easy-plane ferroborates: (a) the longitudinal and transverse magnetoelectric effects have the opposite signs and (b) magnetically induced polarization changes its sign in a field close to the field of exchange between rare-earth and iron ions. These dependences agree well with theoretical predictions based on the symmetry of the compounds. The relatively low f-d exchange field in holmium ferroborate (about 20 kOe), which magnetizes the rare-earth subsystem, causes smaller polarization jumps (about 30 {mu}C/m{sup 2}) in fields lower than 10 kOe as compared to the jumps in other easy-plane ferroborates (R = Sm, Nd). The increase in the electric polarization induced in HoFe{sub 3}(BO{sub 3}){sub 4} in magnetic fields higher than 100 kOe (200-300 {mu}C/m{sup 2}) is found to be significantly smaller than in neodymium ferroborate, which indicates a substantial dependence of the magnetoelectric effects on the electronic structure of a rare-earth ion.

  9. Taking Exomoons to the (Radius) Limit

    NASA Astrophysics Data System (ADS)

    Hinkel, Natalie R.; Kane, S. R.

    2014-01-01

    Moons around extrasolar planets are the next up-and-coming objects to be not only observed, but characterized for possible habitability. As with planets orbiting stars, exomoons have a limiting radius at which they are gravitationally bound, or the Hill radius. At a particular distance, they may also become tidally locked and therefore be in a synchronous rotation with the host-planet. We have examined the flux phase profile of a simulated, hypothetical moon orbiting at a distant radius around the confirmed exoplanets μ Ara b, HD 28185 b, BD +14 4559 b, and HD 73534 b. The irradiated flux on an exomoon at it's furthest, stable distance from the planet achieves its largest flux gradient, which places a limit on the flux ranges expected for subsequent (observed) moons closer in distance. We have also analyzed the effect of planetary eccentricity and time spent within the habitable zone on the flux on the moon. From stellar contributions alone, we find moons with host-planets fully within the habitable zone experience thermal equilibrium temperatures above the runaway greenhouse limit, requiring a small heat redistribution efficiency. In contrast, exomoons orbiting planets that only spend a fraction of their time within the habitable zone require a heat redistribution efficiency near 100% in order to achieve temperatures suitable for habitability. In other words, a planet might not need to spend its entire orbit within the habitable zone in order for the exomoon to be potentially habitable. In this way our findings separate exomoons and exoplanets, but it broadens the scope of worlds that may occupy a habitable zone.

  10. [Vascularized iliac crest and distal radius reconstruction].

    PubMed

    Pic Gomis, L; Gomis, R

    2010-12-01

    The authors relate their experience concerning the vascularized iliac crest flap. In the first chapter, they detail the anatomic vascularized osteocutaneous iliac crest. Blood supply arises from the deep and superficial circonflexe iliac artery. Many anastomoses connect the two systems. In the second chapter, they detail the operative technique of free and pedicule hone iliac crest flap. Composite cutaneous bone flaps are also detailed. In the third chapter, they detail informations about treatment of distal radius bone defects with associated skeen flap if necessary.

  11. Ionic liquids in tribology.

    PubMed

    Minami, Ichiro

    2009-06-24

    Current research on room-temperature ionic liquids as lubricants is described. Ionic liquids possess excellent properties such as non-volatility, non-flammability, and thermo-oxidative stability. The potential use of ionic liquids as lubricants was first proposed in 2001 and approximately 70 articles pertaining to fundamental research on ionic liquids have been published through May 2009. A large majority of the cations examined in this area are derived from 1,3-dialkylimidazolium, with a higher alkyl group on the imidazolium cation being beneficial for good lubrication, while it reduces the thermo-oxidative stability. Hydrophobic anions provide both good lubricity and significant thermo-oxidative stability. The anions decompose through a tribochemical reaction to generate metal fluoride on the rubbed surface. Additive technology to improve lubricity is also explained. An introduction to tribology as an interdisciplinary field of lubrication is also provided.

  12. Applications of ionic liquids.

    PubMed

    Patel, Divia Dinesh; Lee, Jong-Min

    2012-06-01

    Ionic liquids have recently gained popularity in the scientific community owing to their special properties and characteristics. One of the reasons why ionic liquids have been termed "green solvents" is due to their negligible vapour pressure. Their use in electrochemical, biological and metal extraction applications is discussed. Wide research has been carried out for their use in batteries, solar panels, fuel cells, drug deliveries and biomass pretreatments. This work aims to consolidate the various findings from previous works in these areas.

  13. Distal radius fracture after proximal row carpectomy

    PubMed Central

    Igeta, Yuka; Naito, Kiyohito; Sugiyama, Yoichi; Obata, Hiroyuki; Aritomi, Kentaro; Kaneko, Kazuo; Obayashi, Osamu

    2015-01-01

    Introduction We encountered a patient with distal radius fracture (DRF) after proximal row carpectomy (PRC). The mechanism of the DRF after PRC is discussed in this report. Presentation of case The patient was a 73-year-old female who had undergone PRC due to Kienböck disease before. The wrist range of motion was: 45° on dorsiflexion and 20° on flexion. DRF has occurred at 3 years after PRC. The fracture type was extra-articular fracture. Osteosynthesis was performed using a volar locking plate. No postoperative complication developed, the Mayo score was excellent at 6 months after surgery, and the daily living activity level recovered to that before injury. Discussion Since the wrist range of motion decreased and the lunate fitted into the joint surface after PRC, making the forearm join with the hand like a single structure, pressure may have been loaded on the weak distal end of the radius from the dorsal side, causing volar displacement and fracture. Conclusion The pressure distribution and range of motion of the radiocarpal joint after PRC are different from those of a normal joint, and the mechanism of fracture also changes due to PRC. PMID:25623755

  14. An Exoplanet Radius and Transit Timing Survey

    NASA Astrophysics Data System (ADS)

    Deming, Drake; Jennings, Jonald; Sada, Pedro

    2009-08-01

    Many exoplanet systems contain Jupiter-mass planets on close-in orbits. Theories of planetary system formation account for these hot Jupiters as being end states of inward migration. Variants of those theories also predict terrestrial planets to be captured in mean motion resonance with the hot Jupiters. A recent explosion of discoveries by transit surveys have given us a sample of 37 hot Jupiters transiting planets brighter than V=13. A transit timing survey of these systems could detect hot Earths in resonance, via the large (~ 180 second) perturbations they induce on the giant planet transits. Moreover, the discovery photometry for these systems usually provides only relatively coarse photometric precision, but larger-aperture follow-up can determine the giant planet radius to a precision limited only by knowledge of the stellar mass, and thereby reveal the diversity of giant exoplanet structure, such as the presence of heavy element cores. The relatively large sample now available means that a radius- and transit timing-survey is well matched to classical observing and telescope scheduling. We propose continued observations to perform transit photometry using FLAMINGOS on the 2.1-meter in the J-band, where stellar limb darkening is minimal and transit photometry has excellent sensitivity to planetary radii and shifts in transit time.

  15. An Exoplanet Radius and Transit Timing Survey

    NASA Astrophysics Data System (ADS)

    Deming, Drake; Jennings, Jonald; Sada, Pedro

    2010-02-01

    Many exoplanet systems contain Jupiter-mass planets on close-in orbits. Theories of planetary system formation account for these hot Jupiters as being end states of inward migration. Variants of those theories also predict terrestrial planets to be captured in mean motion resonance with the hot Jupiters. A continuing explosion of discoveries by transit surveys have given us a sample of 45 hot Jupiters transiting planets brighter than V=13. A transit timing survey of these systems could detect hot Earths in resonance, via the large (~ 180 second) perturbations they induce on the giant planet transits. Moreover, the discovery photometry for these systems usually provides only relatively coarse photometric precision, but larger-aperture follow-up can determine the giant planet radius to a precision limited only by knowledge of the stellar mass, and thereby reveal the diversity of giant exoplanet structure, such as the presence of heavy element cores. The relatively large sample now available means that a radius- and transit timing-survey is well matched to classical observing and telescope scheduling. We propose continued observations to perform transit photometry using FLAMINGOS on the 2.1-meter in the J-band, where stellar limb darkening is minimal and transit photometry has excellent sensitivity to planetary radii and shifts in transit time.

  16. Triplane fracture of the distal radius.

    PubMed

    García-Mata, Serafín; Hidalgo-Ovejero, Angel

    2006-07-01

    A case of triplane fracture of the distal radius is reported in a 13-year-old boy. This exceptional fracture showed displacement, and was healed by closed reduction and 6 weeks of external immobilization. Eighteen months later, the patient showed complete physeal arrest of the distal radius, with radio-ulnar length discrepancy but without any repercussion on wrist mobility. The patient was declared asymptomatic 3 years after the injury. Prompt, physiological physeal arrest reduces the potential of growth deformity. These fractures must be treated conservatively by closed reduction (if displacement exists) and external immobilization, just like a normal one-plane fracture. We may suppose that final radio-ulnar discrepancy could lead to a painful and symptomatic ulno-carpal conflict in adult life. The following characteristics can be associated with this rare fracture: (1) occurrence close to the end of the growth period, as in other types of triplane fractures; (2) evolution towards partial or complete growth arrest of the physis, not requiring treatment and (3) stability of the fracture after closed reduction. In the present case, as in the other reported cases, it may also be added that orthopaedic treatment has been the rule, in contrast with triplane fractures occurring in the distal tibia, in which surgical treatment is indicated.

  17. On the radius of convergence for multipole expansion

    SciTech Connect

    Lee, S. Y.

    1989-10-01

    Analytic evaluation of multipole expansion coefficients gives us a tool to study the validity and the radius of convergence for the multipole expansion of the magnetic field. We found that the multipoles (up to 18th terms) can accurately describe the magnetic field within 80% of the coil radius. Outside the radius of convergence, the multipole expansion deviates appreciably from the exact magnetic field.

  18. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to measure...

  19. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to measure...

  20. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to measure...

  1. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to measure...

  2. Ultrasound-Assisted Distal Radius Fracture Reduction

    PubMed Central

    Socransky, Steve; Skinner, Andrew; Bromley, Mark; Smith, Andrew; Anawati, Alexandre; Middaugh, Jeff; Ross, Peter

    2016-01-01

    Introduction Closed reduction of distal radius fractures (CRDRF) is a commonly performed emergency department (ED) procedure. The use of point-of-care ultrasound (PoCUS) to diagnose fractures and guide reduction has previously been described. The primary objective of this study was to determine if the addition of PoCUS to CRDRF changed the perception of successful initial reduction. This was measured by the rate of further reduction attempts based on PoCUS following the initial clinical determination of achievement of best possible reduction. Methods  We performed a multicenter prospective cohort study, using a convenience sample of adult ED patients presenting with a distal radius fracture to five Canadian EDs. All study physicians underwent standardized PoCUS training for fractures. Standard clinically-guided best possible fracture reduction was initially performed. PoCUS was then used to assess the reduction adequacy. Repeat reduction was performed if deemed indicated. A post-reduction radiograph was then performed. Clinician impression of reduction adequacy was scored on a 5 point Likert scale following the initial clinically-guided reduction and following each PoCUS scan and the post-reduction radiograph. Results  There were 131 patients with 132 distal radius fractures. Twelve cases were excluded prior to analysis. There was no significant difference in the assessment of the initial reduction status by PoCUS as compared to the clinical exam (mean score: 3.8 vs. 3.9; p = 0.370; OR 0.89; 95% CI 0.46 to 1.72; p = 0.87). Significantly fewer cases fell into the uncertain category with PoCUS than with clinical assessment (2 vs 12; p = 0.008). Repeat reduction was performed in 49 patients (41.2%). Repeat reduction led to a significant improvement (p < 0.001) in the PoCUS determined adequacy of reduction (mean score: 4.3 vs 3.1; p < 0.001). In this group, the odds ratio for adequate vs. uncertain or inadequate reduction assessment using PoCUS was 12.5 (95% CI 3

  3. Are Ionic Liquids Chemically Stable?

    PubMed

    Wang, Binshen; Qin, Li; Mu, Tiancheng; Xue, Zhimin; Gao, Guohua

    2017-02-27

    Ionic liquids have attracted a great deal of interest in recent years, illustrated by their applications in a variety of areas involved with chemistry, physics, biology, and engineering. Usually, the stabilities of ionic liquids are highlighted as one of their outstanding advantages. However, are ionic liquids really stable in all cases? This review covers the chemical stabilities of ionic liquids. It focuses on the reactivity of the most popular imidazolium ionic liquids at structural positions, including C2 position, N1 and N3 positions, and C4 and C5 positions, and decomposition on the imidazolium ring. Additionally, we discuss decomposition of quaternary ammonium and phosphonium ionic liquids and hydrolysis and nucleophilic reactions of anions of ionic liquids. The review aims to arouse caution on potential decomposition of ionic liquids and provides a guide for better utilization of ionic liquids.

  4. Understanding the mass-radius relation for sub-Neptunes: radius as a proxy for composition

    SciTech Connect

    Lopez, Eric D.; Fortney, Jonathan J.

    2014-09-01

    Transiting planet surveys like Kepler have provided a wealth of information on the distribution of planetary radii, particularly for the new populations of super-Earth- and sub-Neptune-sized planets. In order to aid in the physical interpretation of these radii, we compute model radii for low-mass rocky planets with hydrogen-helium envelopes. We provide model radii for planets 1-20 M {sub ⊕}, with envelope fractions 0.01%-20%, levels of irradiation 0.1-1000 times Earth's, and ages from 100 Myr to 10 Gyr. In addition we provide simple analytic fits that summarize how radius depends on each of these parameters. Most importantly, we show that at fixed H/He envelope fraction, radii show little dependence on mass for planets with more than ∼1% of their mass in their envelope. Consequently, planetary radius is to a first order a proxy for planetary composition, i.e., H/He envelope fraction, for Neptune- and sub-Neptune-sized planets. We recast the observed mass-radius relationship as a mass-composition relationship and discuss it in light of traditional core accretion theory. We discuss the transition from rocky super-Earths to sub-Neptune planets with large volatile envelopes. We suggest ∼1.75 R {sub ⊕} as a physically motivated dividing line between these two populations of planets. Finally, we discuss these results in light of the observed radius occurrence distribution found by Kepler.

  5. Physeal arrest of the distal radius.

    PubMed

    Abzug, Joshua M; Little, Kevin; Kozin, Scott H

    2014-06-01

    Fractures of the distal radius are among the most common pediatric fractures. Although most of these fractures heal without complication, some result in partial or complete physeal arrest. The risk of physeal arrest can be reduced by avoiding known risk factors during fracture management, including multiple attempts at fracture reduction. Athletes may place substantial compressive and shear forces across the distal radial physes, making them prone to growth arrest. Timely recognition of physeal arrest can allow for more predictable procedures to be performed, such as distal ulnar epiphysiodesis. In cases of partial arrest, physeal bar excision with interposition grafting can be performed. Once ulnar abutment is present, more invasive procedures may be required, including ulnar shortening osteotomy or radial lengthening.

  6. Effect of A-site ionic size variation on TCR and electrical transport properties of (Nd0.7-xLax)0.7Sr0.3MnO3 with x = 0, 0.1 and 0.2

    NASA Astrophysics Data System (ADS)

    Vadnala, Sudarshan; Asthana, Saket; Pal, Prem; Srinath, S.

    2015-02-01

    In this work, the structural and transport properties of (Nd0.7-xLax)0.7Sr0.3MnO3 manganites with x = 0, 0.1 and 0.2 prepared by solid state reaction route are studied. These compounds are found to be crystallized in orthorhombic structural form. Experimental results showing a shift in the metal to semiconductor/insulator transition temperature (TMI) towards room temperature (289 K) with the substitution of Nd by La, as the value of x is varied in the sequence (0,0.1,0.2), have been provided. The shift in the TMI, from 239 K (for x=0) to near the room temperature 289 K (for x=0.2), is attributed to the fact that the average radius of site-A increases with the percentage of La. The maximum temperature coefficients of resistance (TCR) of (Nd0.7-xLax)0.7Sr0.3MnO3 (x= 0.1 and 0.2) are found to be higher compared to its parent compound Nd0.7Sr0.3MnO3. The electrical transport mechanisms for (Nd0.7-xLax)0.7Sr0.3MnO3 (x= 0 to 0.2) are explored by using different theoretical models, for temperatures below and above TMI. An appropriate enlightenment for the observed behavior is discussed in detail.

  7. Stretchable, transparent, ionic conductors.

    PubMed

    Keplinger, Christoph; Sun, Jeong-Yun; Foo, Choon Chiang; Rothemund, Philipp; Whitesides, George M; Suo, Zhigang

    2013-08-30

    Existing stretchable, transparent conductors are mostly electronic conductors. They limit the performance of interconnects, sensors, and actuators as components of stretchable electronics and soft machines. We describe a class of devices enabled by ionic conductors that are highly stretchable, fully transparent to light of all colors, and capable of operation at frequencies beyond 10 kilohertz and voltages above 10 kilovolts. We demonstrate a transparent actuator that can generate large strains and a transparent loudspeaker that produces sound over the entire audible range. The electromechanical transduction is achieved without electrochemical reaction. The ionic conductors have higher resistivity than many electronic conductors; however, when large stretchability and high transmittance are required, the ionic conductors have lower sheet resistance than all existing electronic conductors.

  8. Lewis Acidic Ionic Liquids.

    PubMed

    Brown, Lucy C; Hogg, James M; Swadźba-Kwaśny, Małgorzata

    2017-08-21

    Until very recently, the term Lewis acidic ionic liquids (ILs) was nearly synonymous with halometallate ILs, with a strong focus on chloroaluminate(III) systems. The first part of this review covers the historical context in which these were developed, speciation of a range of halometallate ionic liquids, attempts to quantify their Lewis acidity, and selected recent applications: in industrial alkylation processes, in supported systems (SILPs/SCILLs) and in inorganic synthesis. In the last decade, interesting alternatives to halometallate ILs have emerged, which can be divided into two sub-sections: (1) liquid coordination complexes (LCCs), still based on halometallate species, but less expensive and more diverse than halometallate ionic liquids, and (2) ILs with main-group Lewis acidic cations. The two following sections cover these new liquid Lewis acids, also highlighting speciation studies, Lewis acidity measurements, and applications.

  9. Effect of ionic radii on the Curie temperature in Ba1-x-ySrxCayTiO3 compounds.

    PubMed

    Berenov, A; Le Goupil, F; Alford, N

    2016-06-21

    A series of Ba1-x-ySrxCayTiO3 compounds were prepared with varying average ionic radii and cation disorder on A-site. All samples showed typical ferroelectric behavior. A simple empirical equation correlated Curie temperature, TC, with the values of ionic radii of A-site cations. This correlation was related to the distortion of TiO6 octahedra observed during neutron diffraction studies. The equation was used for the selection of compounds with predetermined values of TC. The effects of A-site ionic radii on the temperatures of phase transitions in Ba1-x-ySrxCayTiO3 were discussed.

  10. Effect of ionic radii on the Curie temperature in Ba1-x-ySrxCayTiO3 compounds

    NASA Astrophysics Data System (ADS)

    Berenov, A.; Le Goupil, F.; Alford, N.

    2016-06-01

    A series of Ba1-x-ySrxCayTiO3 compounds were prepared with varying average ionic radii and cation disorder on A-site. All samples showed typical ferroelectric behavior. A simple empirical equation correlated Curie temperature, TC, with the values of ionic radii of A-site cations. This correlation was related to the distortion of TiO6 octahedra observed during neutron diffraction studies. The equation was used for the selection of compounds with predetermined values of TC. The effects of A-site ionic radii on the temperatures of phase transitions in Ba1-x-ySrxCayTiO3 were discussed.

  11. Polymerizable ionic liquid crystals.

    PubMed

    Jazkewitsch, Olga; Ritter, Helmut

    2009-09-17

    Polymerizable vinylimidazolium ionic liquids (ILs) that contain mesogenic coumarin and biphenyl units, respectively, have been synthesized. The N-alkylation of N-vinylimidazole with bromoalkylated mesogenic units 7-(6-bromohexyloxy)coumarin (1) and 4,4'-bis(6-bromohexyloxy)biphenyl (2) was then carried out. The thermal behavior of the obtained ILs 3 and 4 was investigated by differential scanning calorimetry and polarizing optical microscopy. These measurements showed that the attached mesogenic units induce the self-assembly of ILs and, therefore, the occurrence of liquid crystalline phases. Subsequently, the ionic liquid crystals (ILCs) 3 and 4 were polymerized by a free-radical mechanism.

  12. Ionic liquids in chemical engineering.

    PubMed

    Werner, Sebastian; Haumann, Marco; Wasserscheid, Peter

    2010-01-01

    The development of engineering applications with ionic liquids stretches back to the mid-1990s when the first examples of continuous catalytic processes using ionic liquids and the first studies of ionic liquid-based extractions were published. Ever since, the use of ionic liquids has seen tremendous progress in many fields of chemistry and engineering, and the first commercial applications have been reported. The main driver for ionic liquid engineering applications is to make practical use of their unique property profiles, which are the result of a complex interplay of coulombic, hydrogen bonding and van der Waals interactions. Remarkably, many ionic liquid properties can be tuned in a wide range by structural modifications at their cation and anion. This review highlights specific examples of ionic liquid applications in catalysis and in separation technologies. Additionally, the application of ionic liquids as working fluids in process machines is introduced.

  13. Fragmentation of a jet with small radius

    NASA Astrophysics Data System (ADS)

    Dai, Lin; Kim, Chul; Leibovich, Adam K.

    2016-12-01

    In this paper, we consider the fragmentation of a parton into a jet with small jet radius R . Perturbatively, logarithms of R can appear, which for narrow jets can lead to large corrections. Using soft-collinear effective theory, we introduce the fragmentation function to a jet (FFJ), which describes the fragmentation of a parton into a jet. We discuss how these objects are related to the standard jet functions. Calculating the FFJ to next-to-leading order, we show that these objects satisfy the standard Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations, with a natural scale that depends upon R . By using the standard renormalization group evolution, we can therefore resum logarithms of R . We further use the soft-collinear effective theory to prove a factorization theorem where the FFJs naturally appear, for the fragmentation of a hadron within a jet with small R . Finally, we also show how this formalism can be used to resum the ratio of jet radii for a subjet to be emitted from within a fat jet.

  14. Experimental study of finite Larmor radius effects

    SciTech Connect

    Struve, K.W.

    1980-08-01

    Linear Z-pinches in Ar, Kr, Xe, N/sub 2/, and He are experimentally studied in regimes where strong finite Larmor radius effects could provide a significant stabilizing effect. Scaling arguments show that for deuterium such a pinch has an electron line density of order 2 x 10/sup 15//cm. For higher Z plasmas a higher line density is allowed, the exact value of which depends on the average ion charge. The pinch is formed by puffing gas axially through the cathode towards the anode of an evacuated pinch chamber. When the gas reaches the anode, the pinch bank is fired. The pinch current rises in 2 to 3 ..mu..sec to a maximum of 100 to 200 kA. The pinch bank capacitance is 900 ..mu..F, and the external inductance is 100 nH. Additionally, the bank is fused to increase dI/dt. The primary diagnostics are a framing camera, a spatially resolved Mach-Zehnder interferometer, and X-ray absorption.

  15. [Loco typico radius fractures--personal experience].

    PubMed

    Darabos, Nikica; Cesarec, Marijan

    2003-01-01

    Fractura radii loco typico (FRLT) is the fracture of the distal radius. That is the one of the most frequent fractures of locomotor system with the widest range of treatment in traumatology. Therapy depends on the stability of the fracture: nonoperative or operative. We analysed the five-year experience of our Department of Traumatology where more than 1500 patients with FRLT have been treated in the urgent surgery clinic and 126 of them were hospitalized. In our study we evaluated the results of the operative treatment and postoperative functional status of a treated wrist. According to the A-O classification, we hospitalized 36 patients with A type, 28 patients with B type, and 62 patients with C type of FRLT. We operated 80 patients. The postoperative functional status of a treated wrist was excellent or good in 64 patients and good in 16 patients. The treatment of FRLT depends on the type and the complications of the fracture and the age of the patients. Operative therapy is indicated in the unstable FRLT or after an inadequate nonoperative treatment.

  16. On Galaxy Mass-Radius Relationship

    NASA Astrophysics Data System (ADS)

    Bindoni, D.; Secco, L.; Contini, E.; Caimmi, R.

    In the Clausius' virial maximum theory (TCV) [Secco and Bindoni, NewA 14, 567 (2009)] to explain the galaxy Fundamental Plane (FP) a natural explanation follows about the observed relationship between stellar mass and effective radius, M ∗ - r e , for early type galaxies (ETGs). The key of this correlation lies in the deep link which has to exist between cosmology and the existence of the FP. The general strategy consists in using the two-component tensor virial theorem to describe the virial configuration of the baryonic component of mass M B ≃ M ∗ embedded in a dark matter (DM) halo of mass M D at the end of relaxation phase. In a ΛCDM flat cosmology, starting from variance at equivalence epoch, we derive some preliminary theoretical relationships, M ∗ - r e , which are functions of mass ratio m = M D / M B . They appear to be in agreement with the trends extracted from the data of galaxy sample used by [Tortora et al., MNRAS 396, 1132 (2009)].

  17. New Physics and the Proton Radius Problem

    SciTech Connect

    Carl E. Carlson, Benjamin C. Rislow

    2012-08-01

    Background: The recent disagreement between the proton charge radius extracted from Lamb shift measurements of muonic and electronic hydrogen invites speculation that new physics may be to blame. Several proposals have been made for new particles that account for both the Lamb shift and the muon anomalous moment discrepancies. Purpose: We explore the possibility that new particles' couplings to the muon can be fine-tuned to account for all experimental constraints. Method: We consider two fine-tuned models, the first involving new particles with scalar and pseudoscalar couplings, and the second involving new particles with vector and axial couplings. The couplings are constrained by the Lamb shift and muon magnetic moments measurements while mass constraints are obtained by kaon decay rate data. Results: For the scalar-pseudoscalar model, masses between 100 to 200 MeV are not allowed. For the vector model, masses below about 200 MeV are not allowed. The strength of the couplings for both models approach that of electrodynamics for particle masses of about 2 GeV. Conclusions: New physics with fine tuned couplings may be entertained as a possible explanation for the Lamb shift discrepancy.

  18. Fun with Ionic Compounds

    ERIC Educational Resources Information Center

    Logerwell, Mollianne G.; Sterling, Donna R.

    2007-01-01

    Ionic bonding is a fundamental topic in high school chemistry, yet it continues to be a concept that students struggle to understand. Even if they understand atomic structure and ion formation, it can be difficult for students to visualize how ions fit together to form compounds. This article describes several engaging activities that help…

  19. Fun with Ionic Compounds

    ERIC Educational Resources Information Center

    Logerwell, Mollianne G.; Sterling, Donna R.

    2007-01-01

    Ionic bonding is a fundamental topic in high school chemistry, yet it continues to be a concept that students struggle to understand. Even if they understand atomic structure and ion formation, it can be difficult for students to visualize how ions fit together to form compounds. This article describes several engaging activities that help…

  20. Synthesis of ionic liquids

    DOEpatents

    Dai, Sheng; Luo, Huimin

    2011-11-01

    Ionic compounds which are liquids at room temperature are formed by the method of mixing a neutral organic ligand with the salt of a metal cation and its conjugate anion. The liquids are hydrophobic, conductive and stable and have uses as solvents and in electrochemical devices.

  1. Synthesis of ionic liquids

    DOEpatents

    Dai, Sheng [Knoxville, TN; Luo, Huimin [Knoxville, TN

    2008-09-09

    Ionic compounds which are liquids at room temperature are formed by the method of mixing a neutral organic liqand with the salt of a metal cation and its conjugate anion. The liquids are hydrophobic, conductive and stable and have uses as solvents and in electrochemical devices.

  2. Ionic Channels in Thunderclouds

    NASA Astrophysics Data System (ADS)

    Losseva, T. V.; Fomenko, A. S.; Nemtchinov, I. V.

    2007-12-01

    We proceed to study the formation and propagation of ionic channels in thunderclouds in the framework of the model of the corona discharge wave propagation (Fomenko A.S., Losseva T.V., Nemtchinov I.V. The corona discharge waves in thunderclouds and formation of ionic channels // 2004 Fall Meeting. EOS Trans. AGU. 2004. V. 85. ¹ 47. Suppl. Abstract AE23A-0835.). In this model we proposed a hypothesis that the structure of a thundercloud becomes nonuniform due to corona discharge on the drops and ice particles and formation of ionic channels with higher conductivity than the surrounding air. When the onset strength of corona discharge becomes smaller than the electric field strength the corona discharge increases concentrations of ions in a small part of the cloud (a hot spot). An additional charge at opposite ends of the hot spot forms due to polarization process. The increased electric field initiates corona discharge in other parts of the cloud on ice particles and water drops with smaller sizes. The corona discharge front moves as a wave with the velocity of the order of ion drift and formes a highly conductive channel. We model this non-stationary problem with Poisson equation which is solved simultaneously with a simplified set of kinetic equations for ions, small charged particles and electrons (at high electric fields), including ionization due to electronic impact, attachment and formation of positive ions. By applying 3D numerical simulations we obtain the parameters of formed ionic channels with respect to onset electric fields both from large particles (in hot spot) and from small particles (surrounding hot spot), microscopic currents from particles with different sizes and the external electric field in the cloud. The interaction of ionic channels is also investigated. This work was supported by Russian Foundation of Basic Research (Project No 07-05-00998-à).

  3. Tidal radius estimates for three open clusters

    NASA Astrophysics Data System (ADS)

    Danilov, V. M.; Loktin, A. V.

    2015-10-01

    A new method is developed for estimating tidal radii and masses of open star clusters (OCL) based on the sky-plane coordinates and proper motions and/or radial velocities of cluster member stars. To this end, we perform the correlation and spectral analysis of oscillations of absolute values of stellar velocity components relative to the cluster mass center along three coordinate planes and along each coordinate axis in five OCL models. Mutual correlation functions for fluctuations of absolute values of velocity field components are computed. The spatial Fourier transform of the mutual correlation functions in the case of zero time offset is used to compute wavenumber spectra of oscillations of absolute values of stellar velocity components. The oscillation spectra of these quantities contain series of local maxima at equidistant wavenumber k values. The ratio of the tidal radius of the cluster to the wavenumber difference Δ k of adjacent local maxima in the oscillation spectra of absolute values of velocity field components is found to be the same for all five OCL models. This ratio is used to estimate the tidal radii and masses of the Pleiades, Praesepe, and M67 based on the proper motions and sky-plane coordinates of the member stars of these clusters. The radial dependences of the absolute values of the tangential and radial projections of cluster star velocities computed using the proper motions relative to the cluster center are determined, along with the corresponding autocorrelation functions and wavenumber spectra of oscillations of absolute values of velocity field components. The Pleiades virial mass is estimated assuming that the cluster is either isolated or non-isolated. Also derived are the estimates of the Pleiades dynamical mass assuming that it is non-stationary and non-isolated. The inferred Pleiades tidal radii corresponding to these masses are reported.

  4. New concepts in the treatment of distal radius fractures.

    PubMed

    Taras, John S; Ladd, Amy L; Kalainov, David M; Ruch, David S; Ring, David C

    2010-01-01

    Fracture of the distal radius is the type of fracture most commonly seen in emergency departments. The understanding of nonsurgical and surgical care of distal radius fractures is evolving with recently developed methods of fixation. It is worthwhile to review some new methods of treatment, the role of bone grafting and synthetic substitutes, the principles of complex fracture management, and the treatment of common complications of distal radius fractures.

  5. Pattern formation of stationary transcellular ionic currents in Fucus

    PubMed Central

    Léonetti, M.; Dubois-Violette, E.; Homblé, F.

    2004-01-01

    Stationary and nonstationary spatiotemporal pattern formations emerging from the cellular electric activity are a common feature of biological cells and tissues. The nonstationary ones are well explained in the framework of the cable model. Inversely, the formation of the widespread self-organized stationary patterns of transcellular ionic currents remains elusive, despite their importance in cell polarization, apical growth, and morphogenesis. For example, the nature of the breaking symmetry in the Fucus zygote, a model organism for the experimental investigation of embryonic pattern formation, is still an open question. Using an electrodiffusive model, we report here an unexpected property of the cellular electric activity: a phase-space domain that gives rise to stationary patterns of transcellular ionic currents at finite wavelength. The cable model cannot predict this instability. In agreement with experiments, the characteristic time is an ionic diffusive one (<2 min). The critical radius is of the same order of magnitude as the cell radius (30 μm). The generic salient features are a global positive differential conductance, a negative differential conductance for one ion, and a difference between the diffusive coefficients. Although different, this mechanism is reminiscent of Turing instability. PMID:15232004

  6. An Investigation of Ionic Wind Propulsion

    NASA Technical Reports Server (NTRS)

    Wilson, Jack; Perkins, Hugh D.; Thompson, William K.

    2009-01-01

    A corona discharge device generates an ionic wind and thrust, when a high voltage corona discharge is struck between sharply pointed electrodes and larger radius ground electrodes. The objective of this study was to examine whether this thrust could be scaled to values of interest for aircraft propulsion. An initial experiment showed that the thrust observed did equal the thrust of the ionic wind. Different types of high voltage electrodes were tried, including wires, knife-edges, and arrays of pins. A pin array was found to be optimum. Parametric experiments, and theory, showed that the thrust per unit power could be raised from early values of 5 N/kW to values approaching 50 N/kW, but only by lowering the thrust produced, and raising the voltage applied. In addition to using DC voltage, pulsed excitation, with and without a DC bias, was examined. The results were inconclusive as to whether this was advantageous. It was concluded that the use of a corona discharge for aircraft propulsion did not seem very practical.

  7. Improving optical bench radius measurements using stage error motion data.

    PubMed

    Schmitz, Tony L; Gardner, Neil; Vaughn, Matthew; Medicus, Kate; Davies, Angela

    2008-12-20

    We describe the application of a vector-based radius approach to optical bench radius measurements in the presence of imperfect stage motions. In this approach, the radius is defined using a vector equation and homogeneous transformation matrix formulism. This is in contrast to the typical technique, where the displacement between the confocal and cat's eye null positions alone is used to determine the test optic radius. An important aspect of the vector-based radius definition is the intrinsic correction for measurement biases, such as straightness errors in the stage motion and cosine misalignment between the stage and displacement gauge axis, which lead to an artificially small radius value if the traditional approach is employed. Measurement techniques and results are provided for the stage error motions, which are then combined with the setup geometry through the analysis to determine the radius of curvature for a spherical artifact. Comparisons are shown between the new vector-based radius calculation, traditional radius computation, and a low uncertainty mechanical measurement. Additionally, the measurement uncertainty for the vector-based approach is determined using Monte Carlo simulation and compared to experimental results.

  8. Ionic electroactive hybrid transducers

    NASA Astrophysics Data System (ADS)

    Akle, Barbar J.; Bennett, Matthew D.; Leo, Donald J.

    2005-05-01

    Ionic electroactive actuators have received considerable attention in the past ten years. Ionic electroactive polymers, sometimes referred to as artificial muscles, have the ability to generate large bending strain and moderate stress at low applied voltages. Typical types of ionic electroactive polymer transducers include ionic polymers, conducting polymers, and carbon nanotubes. Preliminary research combining multiple types of materials proved to enhance certain transduction properties such as speed of response, maximum strain, or quasi-static actuation. Recently it was demonstrated that ionomer-ionic liquid transducers can operate in air for long periods of time (>250,000 cycles) and showed potential to reduce or eliminate the back-relaxation issue associated with ionomeric polymers. In addition, ionic liquids have higher electrical stability window than those operated with water as the solvent thereby increasing the maximum strain that the actuator can produce. In this work, a new technique developed for plating metal particulates on the surface of ionomeric materials is applied to the development of hybrid transducers that incorporate carbon nanotubes and conducting polymers as electrode materials. The new plating technique, named the direct assembly process, consists of mixing a conducting powder with an ionomer solution. This technique has demonstrated improved response time and strain output as compared to previous methods. Furthermore, the direct assembly process is less costly to implement than traditional impregnation-reduction methods due to less dependence on reducing agents, it requires less time, and is easier to implement than other processes. Electrodes applied using this new technique of mixing RuO2 (surface area 45~65m2/g) particles and Nafion dispersion provided 5x the displacement and 10x the force compared to a transducer made with conventional methods. Furthermore, the study illustrated that the response speed of the transducer is optimized

  9. First experimentally determined thermodynamic values of francium: hydration energy, energy of partitioning, and thermodynamic radius.

    PubMed

    Delmau, Lætitia H; Moine, Jérôme; Mirzadeh, Saed; Moyer, Bruce A

    2013-08-08

    The Gibbs energy of partitioning of Fr(+) ion between water and nitrobenzene has been determined to be 14.5 ± 0.6 kJ/mol at 25 °C, the first ever Gibbs energy of partitioning for francium in particular and the first ever solution thermodynamic quantity for francium in general. This value enabled the ionic radius and standard Gibbs energy of hydration for Fr(+) to be estimated as 173 pm and -251 kJ/mol, respectively, the former value being significantly smaller than previously thought. A new experimental method was established using a cesium dicarbollide as a cation-exchange agent, overcoming problems inherent to the trace-level concentrations of francium. The methodology opens the door to the study of the partitioning behavior of francium to other water-immiscible solvents and the determination of complexation constants for francium binding by receptor molecules.

  10. Super ionic conductive glass

    DOEpatents

    Susman, S.; Volin, K.J.

    Described is an ionically conducting glass for use as a solid electrolyte in a power or secondary cell containing an alkali metal-containing anode and a cathode separated by an alkali metal ion conducting glass having an ionic transference number of unity and the general formula: A/sub 1 + x/D/sub 2-x/3/Si/sub x/P/sub 3 - x/O/sub 12 - 2x/3/, wherein A is a network modifier for the glass and is an alkali metal of the anode, D is an intermediate for the glass and is selected from the class consisting of Zr, Ti, Ge, Al, Sb, Be, and Zn and X is in the range of from 2.25 to 3.0. Of the alkali metals, Na and Li are preferred and of the intermediate, Zr, Ti and Ge are preferred.

  11. Super ionic conductive glass

    DOEpatents

    Susman, Sherman; Volin, Kenneth J.

    1984-01-01

    An ionically conducting glass for use as a solid electrolyte in a power or secondary cell containing an alkali metal-containing anode and a cathode separated by an alkali metal ion conducting glass having an ionic transference number of unity and the general formula: A.sub.1+x D.sub.2-x/3 Si.sub.x P.sub.3-x O.sub.12-2x/3, wherein A is a network modifier for the glass and is an alkali metal of the anode, D is an intermediate for the glass and is selected from the class consisting of Zr, Ti, Ge, Al, Sb, Be, and Zn and X is in the range of from 2.25 to 3.0. Of the alkali metals, Na and Li are preferred and of the intermediate, Zr, Ti and Ge are preferred.

  12. Multi-Enhanced-Phonon Scattering Modes in Ln-Me-A Sites co-substituted LnMeA11O19 Ceramics

    PubMed Central

    Lu, Haoran; Wang, Chang-An; Huang, Yong; Xie, Huimin

    2014-01-01

    Authors reported an effective path to decrease the thermal conductivity while to increase the coefficient of thermal expansion, thus enhancing the thermo-physical properties of the LnMeA11O19-type magnetoplumbite LaMgAl11O19 by simultaneously substituting La3+, Mg2+ and Al3+ ions with large ionic radius Ba2+, Zn2+ and Ti4+, respectively. The mechanism behind the lowered thermal conductivity was mainly due to the multi-enhanced-phonon scattering modes in Ln-Me-A sites co-substituted LnMeA11O19 ceramics. These modes involve the following four aspects, namely, point defect mechanism, the intrinsic scattering in the complex crystal cell and materials with stepped surface to localize phonon vibrational modes, as well as nano-platelet-like structure to incorporate additional grain boundary scattering. This study provides novel thoughts for promising candidate materials of even lower thermal conductivity for the next generation thermal barrier coatings. PMID:25351166

  13. Multi-enhanced-phonon scattering modes in Ln-Me-A sites co-substituted LnMeA11O19 ceramics.

    PubMed

    Lu, Haoran; Wang, Chang-An; Huang, Yong; Xie, Huimin

    2014-10-29

    Authors reported an effective path to decrease the thermal conductivity while to increase the coefficient of thermal expansion, thus enhancing the thermo-physical properties of the LnMeA11O19-type magnetoplumbite LaMgAl11O19 by simultaneously substituting La(3+), Mg(2+) and Al(3+) ions with large ionic radius Ba(2+), Zn(2+) and Ti(4+), respectively. The mechanism behind the lowered thermal conductivity was mainly due to the multi-enhanced-phonon scattering modes in Ln-Me-A sites co-substituted LnMeA11O19 ceramics. These modes involve the following four aspects, namely, point defect mechanism, the intrinsic scattering in the complex crystal cell and materials with stepped surface to localize phonon vibrational modes, as well as nano-platelet-like structure to incorporate additional grain boundary scattering. This study provides novel thoughts for promising candidate materials of even lower thermal conductivity for the next generation thermal barrier coatings.

  14. Magneto-orbital ordering in the divalent A -site quadruple perovskite manganites A Mn7O12 (A =Sr , Cd, and Pb)

    NASA Astrophysics Data System (ADS)

    Johnson, R. D.; Khalyavin, D. D.; Manuel, P.; Radaelli, P. G.; Glazkova, I. S.; Terada, N.; Belik, A. A.

    2017-08-01

    Through analysis of variable-temperature neutron powder-diffraction data, we present solutions for the magnetic structures of SrMn7O12 , CdMn7O12 , and PbMn7O12 in all long-range ordered phases. The three compounds were found to have magnetic structures analogous to that reported for CaMn7O12 . They all feature a higher-temperature lock-in phase with commensurate magneto-orbital coupling and a delocked multi-k magnetic ground state where incommensurate magneto-orbital coupling gives rise to a constant-moment magnetic helix with modulated spin helicity. CdMn7O12 represents a special case in which the orbital modulation is commensurate with the crystal lattice and involves stacking of fully and partially polarized orbital states. Our results provide a robust confirmation of the phenomenological model for magneto-orbital coupling previously presented for CaMn7O12 . Furthermore, we show that the model is universal to the A2 + quadruple perovskite manganites synthesized to date and that it is tunable by selection of the A -site ionic radius.

  15. Thermodynamic estimation: Ionic materials

    SciTech Connect

    Glasser, Leslie

    2013-10-15

    Thermodynamics establishes equilibrium relations among thermodynamic parameters (“properties”) and delineates the effects of variation of the thermodynamic functions (typically temperature and pressure) on those parameters. However, classical thermodynamics does not provide values for the necessary thermodynamic properties, which must be established by extra-thermodynamic means such as experiment, theoretical calculation, or empirical estimation. While many values may be found in the numerous collected tables in the literature, these are necessarily incomplete because either the experimental measurements have not been made or the materials may be hypothetical. The current paper presents a number of simple and relible estimation methods for thermodynamic properties, principally for ionic materials. The results may also be used as a check for obvious errors in published values. The estimation methods described are typically based on addition of properties of individual ions, or sums of properties of neutral ion groups (such as “double” salts, in the Simple Salt Approximation), or based upon correlations such as with formula unit volumes (Volume-Based Thermodynamics). - Graphical abstract: Thermodynamic properties of ionic materials may be readily estimated by summation of the properties of individual ions, by summation of the properties of ‘double salts’, and by correlation with formula volume. Such estimates may fill gaps in the literature, and may also be used as checks of published values. This simplicity arises from exploitation of the fact that repulsive energy terms are of short range and very similar across materials, while coulombic interactions provide a very large component of the attractive energy in ionic systems. Display Omitted - Highlights: • Estimation methods for thermodynamic properties of ionic materials are introduced. • Methods are based on summation of single ions, multiple salts, and correlations. • Heat capacity, entropy

  16. Vibrational Spectroscopy of Ionic Liquids.

    PubMed

    Paschoal, Vitor H; Faria, Luiz F O; Ribeiro, Mauro C C

    2017-01-04

    Vibrational spectroscopy has continued use as a powerful tool to characterize ionic liquids since the literature on room temperature molten salts experienced the rapid increase in number of publications in the 1990's. In the past years, infrared (IR) and Raman spectroscopies have provided insights on ionic interactions and the resulting liquid structure in ionic liquids. A large body of information is now available concerning vibrational spectra of ionic liquids made of many different combinations of anions and cations, but reviews on this literature are scarce. This review is an attempt at filling this gap. Some basic care needed while recording IR or Raman spectra of ionic liquids is explained. We have reviewed the conceptual basis of theoretical frameworks which have been used to interpret vibrational spectra of ionic liquids, helping the reader to distinguish the scope of application of different methods of calculation. Vibrational frequencies observed in IR and Raman spectra of ionic liquids based on different anions and cations are discussed and eventual disagreements between different sources are critically reviewed. The aim is that the reader can use this information while assigning vibrational spectra of an ionic liquid containing another particular combination of anions and cations. Different applications of IR and Raman spectroscopies are given for both pure ionic liquids and solutions. Further issues addressed in this review are the intermolecular vibrations that are more directly probed by the low-frequency range of IR and Raman spectra and the applications of vibrational spectroscopy in studying phase transitions of ionic liquids.

  17. Modeling the interferometric radius measurement using Gaussian beam propagation

    SciTech Connect

    Medicus, Katherine M.; Snyder, James J.; Davies, Angela

    2006-12-01

    We model the interferometric radius measurement using Gaussian beam propagation to identify biases in the measurement due to using a simple geometric ray-trace model instead of the more complex Gaussian model. The radius measurement is based on using an interferometer to identify the test part's position when it is at two null locations, and the distance between the positions is an estimate of the part's radius. The null condition is observed when there is no difference in curvature between the reflected reference and the test wavefronts, and a Gaussian model will provide a first-order estimate of curvature changes due to wave propagation and therefore changes to the radius measurement. We show that the geometric ray assumption leads to radius biases (errors) that are a strong function of the test part radius and increase as the radius of the part decreases. We tested for a bias for both microscaled(<1 mm) and macroscaled parts. The bias is of the order of parts in 105 for micro-optics with radii a small fraction of a millimeter and much smaller for macroscaled optics. The amount of bias depends on the interferometer configuration (numerical aperture, etc.), the nominal radius of the test part, and the distances in the interferometer.

  18. On the critical radius in generalized Ostwald ripening*

    PubMed Central

    Wang, Qin-bo; Robert, Finsy; Xu, Hai-bo; Li, Xi

    2005-01-01

    The relation between the critical radius and the particle size distribution for generalized Ostwald type ripening processes whereby the mass transfer coefficient is modelled by a power law was derived. The critical radius is determined by the growth rate, the mass transfer coefficient and the mass balance, and is independent of whether the limiting stationary growth regime has been obtained. PMID:16052700

  19. bamr: Bayesian analysis of mass and radius observations

    NASA Astrophysics Data System (ADS)

    Steiner, Andrew W.

    2014-08-01

    bamr is an MPI implementation of a Bayesian analysis of neutron star mass and radius data that determines the mass versus radius curve and the equation of state of dense matter. Written in C++, bamr provides some EOS models. This code requires O2scl (ascl:1408.019) be installed before compilation.

  20. Quadriceps force after TKA with femoral single radius.

    PubMed

    Ostermeier, Sven; Stukenborg-Colsman, Christina

    2011-06-01

    New implant designs have incorporated a single radius instead of a multiple radius to the femoral component in order to improve the mechanical function after TKA. We investigated the amount of quadriceps force required to extend the knee during an isokinetic extension cycle of different total knee designs, focusing on the radius of the femoral component (single vs. multiple). Human knee specimens (n = 12, median patient age 68 (63-70) years) were tested in a kinematic knee-simulating machine untreated and after implantation of 2 types of knee prosthesis systems, one with a single femoral radius design and one with a multiple femoral radius design. During the test cycle, a hydraulic cylinder, which simulated the quadriceps muscle, applied sufficient force to the quadriceps tendon to produce a constant extension moment of 31 Nm. The quadriceps extension force was measured from 120° to full knee extension. The shape of the quadriceps force curve was typically sinusoidal before and after TKA, reaching a maximum value of 1,493 N at 110°. With the single femoral radius design, quadriceps force was similar to that of the normal knee: 1,509 N at 110° flexion (p = 0.4). In contrast, the multiple femoral radius design showed an increase in quadriceps extension force relative to the normal knee, with a maximum of 1,721 N at 90° flexion (p = 0.03). The single femoral radius design showed lower maximum extension forces than the multiple femoral radius design. In addition, with the single femoral radius design maximum quadriceps force needed to extend a constant extension force shifted to higher degrees of knee flexion, representing a more physiological quadriceps force pattern, which could have a positive effect on knee function after TKA.

  1. The line tension of two-dimensional ionic fluids

    NASA Astrophysics Data System (ADS)

    Eustaquio-Armenta, María del Rosario; Méndez-Maldonado, Gloria Arlette; González-Melchor, Minerva

    2016-04-01

    Pressure tensor components are very useful in the calculation of the tension associated with a liquid-vapor interface. In this work, we present expressions for the pressure tensor components of two-dimensional ionic fluids, modeled at the level of the primitive model. As an application, we carried out molecular dynamics simulations of liquid-vapor interfaces to calculate the line tension of the 1:1 two-dimensional ionic fluid, whose liquid-vapor coexistence curve had already been obtained in a previous work. The pressure tensor components were validated by simulating states of one phase and reproducing the scalar pressure, previously obtained from bulk simulations and reported in the literature. The effects on the line tension and the coexisting densities, originated by the choice of the Ewald parameters, the cutoff radius, and the interfacial length were also evaluated.

  2. Graphene-ionic liquid composites

    DOEpatents

    Aksay, Ilhan A.; Korkut, Sibel; Pope, Michael; Punckt, Christian

    2016-11-01

    Method of making a graphene-ionic liquid composite. The composite can be used to make elec-trodes for energy storage devices, such as batteries and supercapacitors. Dis-closed and claimed herein is method of making a graphene-ionic liquid com-posite, comprising combining a graphene source with at least one ionic liquid and heating the combination at a temperature of at least about 130 .degree. C.

  3. Design of Energetic Ionic Liquids

    DTIC Science & Technology

    2009-05-12

    effectiveness of the FMO method in both providing accurate results and reducing computational requirements, timings were performed for the ionic liquid ...Technical Paper 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Design of Energetic Ionic Liquids 5b. GRANT NUMBER 5c...Design of Energetic Ionic Liquids challenge project is to address several key technical issues and challenges associated with the characterization

  4. ON THE VARIATION OF SOLAR RADIUS IN ROTATION CYCLES

    SciTech Connect

    Qu, Z. N.; Kong, D. F.; Xiang, N. B.; Feng, W.

    2015-01-10

    The Date Compensated Discrete Fourier Transform and CLEANest algorithm are used to study the temporal variations of the solar radius observed at Rio de Janeiro Observatory from 1998 March 2 to 2009 November 6. The CLEANest spectra show several significant periodicities around 400, 312, 93.5, 86.2, 79.4, 70.9, 53.2, and 26.3 days. Then, combining the data on the daily solar radius measured at Calern Observatory and Rio de Janeiro Observatory and the corresponding daily sunspot areas, we study the short-term periodicity of the solar radius and the role of magnetic field in the variation of the solar radius. The rotation period of the daily solar radius is determined to be statistically significant. Moreover, its temporal evolution is anti-phase with that of sunspot activity, and it is found anti-phase with solar activity. Generally, the stronger solar activity is, the more obvious is the anti-phase relation of radius with solar activity. This indicates that strong magnetic fields have a greater inhibitive effect than weak magnetic fields on the variation of the radius.

  5. Thermoconvective vortices in a cylindrical annulus with varying inner radius

    NASA Astrophysics Data System (ADS)

    Castaño, D.; Navarro, M. C.; Herrero, H.

    2014-12-01

    This paper shows the influence of the inner radius on the stability and intensity of vertical vortices, qualitatively similar to dust devils and cyclones, generated in a cylindrical annulus non-homogeneously heated from below. Little relation is found between the intensity of the vortex and the magnitude of the inner radius. Strong stable vortices can be found for both small and large values of the inner radius. The Rankine combined vortex structure, that characterizes the tangential velocity in dust devils, is clearly observed when small values of the inner radius and large values of the ratio between the horizontal and vertical temperature differences are considered. A contraction on the radius of maximum azimuthal velocity is observed when the vortex is intensified by thermal mechanisms. This radius becomes then nearly stationary when frictional force balances the radial inflow generated by the pressure drop in the center, despite the vortex keeps intensifying. These results connect with the behavior of the radius of the maximum tangential wind associated with a hurricane.

  6. Thermoconvective vortices in a cylindrical annulus with varying inner radius.

    PubMed

    Castaño, D; Navarro, M C; Herrero, H

    2014-12-01

    This paper shows the influence of the inner radius on the stability and intensity of vertical vortices, qualitatively similar to dust devils and cyclones, generated in a cylindrical annulus non-homogeneously heated from below. Little relation is found between the intensity of the vortex and the magnitude of the inner radius. Strong stable vortices can be found for both small and large values of the inner radius. The Rankine combined vortex structure, that characterizes the tangential velocity in dust devils, is clearly observed when small values of the inner radius and large values of the ratio between the horizontal and vertical temperature differences are considered. A contraction on the radius of maximum azimuthal velocity is observed when the vortex is intensified by thermal mechanisms. This radius becomes then nearly stationary when frictional force balances the radial inflow generated by the pressure drop in the center, despite the vortex keeps intensifying. These results connect with the behavior of the radius of the maximum tangential wind associated with a hurricane.

  7. Ionic liquids in bioanalysis.

    PubMed

    Kailasa, Suresh Kumar; Rawat, Karuna A; Wu, Hui-Fen

    2015-01-01

    Ionic liquids (ILs) are entirely composed of ions and they possess fascinating properties, including low volatility, tunable viscosity, miscibility and electrolytic conductivity, which make them promising alternatives to traditional organic solvents used in sample preparation. The recent surge in the number of publications clearly indicates an increasing interest of the analytical and bioanalytical community toward these exciting and unique solvents. This article highlights the recent advances in the use of ILs as extraction solvents, as materials for separation and preconcentration in chromatographic techniques, and as matrices in mass spectrometric techniques for bioassays in biocomplex samples. We also briefly discuss the potential applications of ILs in biocatalysis.

  8. Fracture of the distal radius: epidemiology and premanagement radiographic characterization.

    PubMed

    Porrino, Jack A; Maloney, Ezekiel; Scherer, Kurt; Mulcahy, Hyojeong; Ha, Alice S; Allan, Christopher

    2014-09-01

    Fractures of the distal radius are common and frequently encountered by the radiologist. We review the epidemiology, classification, as well as the concept of instability. Salient qualitative and quantitative features of the distal radius fracture identifiable on the routine radiography series are highlighted. We conclude with a synopsis of descriptors that are of greatest utility to the clinician for treatment planning and that should be addressed in the radiology report. A detailed understanding of the intricacies of the distal radius fracture is necessary for the radiologist to provide a clinically relevant description.

  9. An Asian Perspective on the Management of Distal Radius Fractures

    PubMed Central

    Sebastin, Sandeep J.; Chung, Kevin C.

    2012-01-01

    Synopsis There is little data with regards to the epidemiology, pathology, or management of distal radius fractures from centers in Asia. Asia includes five advanced economies, namely Hong Kong SAR, Japan, Korea, Singapore, and Taiwan and a number of emerging economies prominent among which are China, India, Malaysia, Philippines, and Thailand. This article examines the available epidemiological data from Asia, and compares the management of distal radius fractures in the advanced and emerging Asian economies and how they match up to the current management in the west. It concludes by offering solutions for improving outcomes of distal radius fractures in both the advanced and emerging economies of Asia. PMID:22554658

  10. Ionic liquids, electrolyte solutions including the ionic liquids, and energy storage devices including the ionic liquids

    DOEpatents

    Gering, Kevin L.; Harrup, Mason K.; Rollins, Harry W.

    2015-12-08

    An ionic liquid including a phosphazene compound that has a plurality of phosphorus-nitrogen units and at least one pendant group bonded to each phosphorus atom of the plurality of phosphorus-nitrogen units. One pendant group of the at least one pendant group comprises a positively charged pendant group. Additional embodiments of ionic liquids are disclosed, as are electrolyte solutions and energy storage devices including the embodiments of the ionic liquid.

  11. Small angle neutron scattering studies of the structure of nucleosome cores at low ionic strength

    NASA Astrophysics Data System (ADS)

    Mita, Kazuei; Zama, Mitsuo; Ichimura, Sachiko; Niimura, Nobuo; Kaji, Keisuke; Hirai, Mitsuhiro; Ishikawa, Yoshikazu

    1983-05-01

    The structure of the nucleosome core particle at low ionic strenth (10-0.04 mM Na +) has been studied by small angle neutron scattering in various H 2O/D 2O mixtures. At 0.04 mM Na +,the radius of gyration obtained at 39% D 2O where scattering from the DNA dominates was 32 Å, and at 65% D 2O where scattering from the histones dominates, 40 Å. An abrupt increase in the radius of gyration from 35 to 40 Å was observed at about 1 mM ionic strength at 65% D 2O, with decreasing the ionic strength from 10 mM. No loss of the histone secondary structure was detected by circular dichroism over the range of the ionic strength examined. These results suggest that at low ionic strength (⪅1 mM) the histones are located outside of the nucleosome core particle accompanied by an alteration of the tertiary and/or quaternary structure of the histone octamer, with the DNA in a folded conformation.

  12. Pyrrolidinium ionic liquid crystals.

    PubMed

    Goossens, Karel; Lava, Kathleen; Nockemann, Peter; Van Hecke, Kristof; Van Meervelt, Luc; Driesen, Kris; Görller-Walrand, Christiane; Binnemans, Koen; Cardinaels, Thomas

    2009-01-01

    N-alkyl-N-methylpyrrolidinium cations have been used for the design of ionic liquid crystals, including a new type of uranium-containing metallomesogen. Pyrrolidinium salts with bromide, bis(trifluoromethylsulfonyl)imide, tetrafluoroborate, hexafluorophosphate, thiocyanate, tetrakis(2- thenoyltrifluoroacetonato)europate(III) and tetrabromouranyl counteranions were prepared. For the bromide salts and tetrabromouranyl compounds, the chain length of the alkyl group C(n)H(2n+1) was varied from eight to twenty carbon atoms (n = 8, 10-20). The compounds show rich mesomorphic behaviour: highly ordered smectic phases (the crystal smectic E phase and the uncommon crystal smectic T phase), smectic A phases, and hexagonal columnar phases were observed, depending on chain length and anion. This work gives better insight into the nature and formation of the crystal smectic T phase, and the molecular requirements for the appearance of this highly ordered phase. This uncommon tetragonal mesophase is thoroughly discussed on the basis of detailed powder X-ray diffraction experiments and in relation to the existing literature. Structural models are proposed for self-assembly of the molecules within the smectic layers. In addition, the photophysical properties of the compounds containing a metal complex anion were investigated. For the uranium-containing mesogens, luminescence can be induced by dissolving them in an ionic liquid matrix. The europium-containing compound shows intense red photoluminescence with high colour purity.

  13. Applying Occam's Razor To The Proton Radius Puzzle

    NASA Astrophysics Data System (ADS)

    Higinbotham, Douglas

    2016-09-01

    Over the past five decades, ever more complex mathematical functions have been used to extract the radius of the proton from electron scattering data. For example, in 1963 the proton radius was extracted with linear and quadratic fits of low Q2 data (< 3 fm-2) and by 2014 a non-linear regression of two tenth order power series functions with thirty-one normalization parameters and data out to 25 fm-2 was used. But for electron scattering, the radius of the proton is determined by extracting the slope of the charge form factor at a Q2 of zero. By using higher precision data than was available in 1963 and focusing on the low Q2 data from 1974 to today, we find extrapolating functions consistently produce a proton radius of around 0.84 fm. A result that is in agreement with modern Lamb shift measurements.

  14. Correlation between quarter-point angle and nuclear radius

    NASA Astrophysics Data System (ADS)

    Ma, Wei-Hu; Wang, Jian-Song; Mukherjee, S.; Wang, Qi; Patel, D.; Yang, Yan-Yun; Ma, Jun-Bing; Ma, Peng; Jin, Shi-Lun; Bai, Zhen; Liu, Xing-Quan

    2017-04-01

    The correlation between quarter-point angle of elastic scattering and nuclear matter radius is studied systematically. Various phenomenological formulae with parameters for nuclear radius are adopted and compared by fitting the experimental data of quarter point angle extracted from nuclear elastic scattering reaction systems. A parameterized formula related to binding energy is recommended, which gives a good reproduction of nuclear matter radii of halo nuclei. It indicates that the quarter-point angle of elastic scattering is quite sensitive to the nuclear matter radius and can be used to extract the nuclear matter radius. Supported by National Natural Science Foundation of China (U1432247, 11575256), National Basic Research Program of China (973 Program)(2014CB845405 and 2013CB83440x) and (SM) Chinese Academy of Sciences President’s International Fellowship Initiative (2015-FX-04)

  15. Split radius-form blocks for tube benders

    NASA Technical Reports Server (NTRS)

    Lange, D. R.; Seiple, C. W.

    1970-01-01

    Two-piece, radius-form block permits accurate forming and removing of parts with more than a 180 degree bend. Tube bender can shape flexible metal tubing in applications dealing with plumbing, heating, and pressure transmission lines.

  16. Radius of Curvature of Off-Axis Paraboloids

    NASA Technical Reports Server (NTRS)

    Robinson, Brian; Reardon, Patrick; Hadaway, James; Geary, Joseph; Russell, Kevin (Technical Monitor)

    2002-01-01

    We present several methods for measuring the vertex radius of curvature of off-axis paraboloidal mirrors. One is based on least-squares fitting of interferometer output, one on comparison of sagittal and tangential radii of curvature, and another on measurement of displacement of the nulled test article from the ideal reference wave. Each method defines radius of curvature differently and, as a consequence, produces its own sort of errors.

  17. Isolated Diaphyseal Fractures of the Radius in Skeletally Immature Patients

    PubMed Central

    Guitton, Thierry G.; Van Dijk, Niek C.; Raaymakers, Ernst L.

    2009-01-01

    Diaphyseal radius fractures without associated ulna fracture or radioulnar dislocation (isolated fracture of the radius) are recognized in adults but are rarely described in skeletally immature patients. A search of our database (1974–2002) identified 17 pediatric patients that had an isolated fracture of the radius. Among the 13 patients with at least 1 year follow-up, ten were treated with manipulative reduction and immobilization in an above elbow cast and three had initial operative treatment with plate and screw fixation. These 13 patients were evaluated for an average of 18 months (range, 12 to 45 months) after injury using the system of Price and colleagues. The incidence of isolated diaphyseal radius fractures in skeletally immature patients was 0.56 per year in our database and represented 27% of the 63 patients with a diaphyseal forearm fracture. All 13 patients, with at least 1 year follow-up, regained full elbow flexion and extension and full forearm rotation. According to the classification system of Price, all 13 patients (100%) had an excellent result. As in adults, isolated radius fractures seem to occur in children more frequently than previously appreciated. Treatment of isolated radius fractures in skeletally immature patients has a low complication rate, and excellent functional outcomes are the rule. PMID:19859772

  18. The seismic radius of the Sun, and structure inversions

    NASA Astrophysics Data System (ADS)

    Takata, M.; Gough, D. O.

    2003-02-01

    It is known (Schou et al., 1997; Antia, 1998) that the effective radius of the Sun determined by f-mode frequencies is different by a few hundredths per cent from the photospheric radius determined by direct photometric measurement (Brown and Christensen-Dalsgaard 1998). It is fair to say that we still do not fully comprehend the implications of the difference, save that the two radii are rather different quantities: the radius inferred from f-mode frequencies is determined by the location of the maximum in the f-mode energy (Gough, 1993), whereas the photospheric radius is determined by extrapolation to some prescribed optical depth from a fiducial point in the limb-darkening function using a theoretical solar model. Both depend in particular on the structure of the upper superadiabatic convective boundary layer, the physics of which is not well understood. In this report we attempt to shed some light on the difference by determining a seismic radius from p-mode frequencies; the outcome depends predominantly on the variation of sound speed, and it is consistent with the f-mode value (Takata and Gough 2001). By considering the mathematical structure of an inversion process that does not explicitly distinguish f modes from p modes, we offer an interpretation of the seismic radius. This interpretation has led us to revise the method by which we carry out structure inversions.

  19. CADDIS Volume 2. Sources, Stressors and Responses: Ionic Strength

    EPA Pesticide Factsheets

    Introduction to the ionic strength module, when to list ionic strength as a candidate cause, ways to measure ionic strength, simple and detailed conceptual diagrams for ionic strength, ionic strength module references and literature reviews.

  20. Electrodeposition in Ionic Liquids.

    PubMed

    Zhang, Qinqin; Wang, Qian; Zhang, Suojiang; Lu, Xingmei; Zhang, Xiangping

    2016-02-03

    Due to their attractive physico-chemical properties, ionic liquids (ILs) are increasingly used as deposition electrolytes. This review summarizes recent advances in electrodeposition in ILs and focuses on its similarities and differences with that in aqueous solutions. The electrodeposition in ILs is divided into direct and template-assisted deposition. We detail the direct deposition of metals, alloys and semiconductors in five types of ILs, including halometallate ILs, air- and water-stable ILs, deep eutectic solvents (DESs), ILs with metal-containing cations, and protic ILs. Template-assisted deposition of nanostructures and macroporous structures in ILs is also presented. The effects of modulating factors such as deposition conditions (current density, current density mode, deposition time, temperature) and electrolyte components (cation, anion, metal salts, additives, water content) on the morphology, compositions, microstructures and properties of the prepared materials are highlighted.

  1. Ionic liquids as surfactants

    NASA Astrophysics Data System (ADS)

    Smirnova, N. A.; Safonova, E. A.

    2010-10-01

    Problems of self-assembling in systems containing ionic liquids (ILs) are discussed. Main attention is paid to micellization in aqueous solutions of dialkylimidazolium ILs and their mixtures with classical surfactants. Literature data are reviewed, the results obtained by the authors and co-workers are presented. Thermodynamic aspects of the studies and problems of molecular-thermodynamic modeling receive special emphasis. It is shown that the aggregation behavior of dialkylimidazolium ILs is close to that of alkyltrimethylammonium salts (cationic surfactants) though ILs have a higher ability to self-organize, especially as it concerns long-range ordering. Some aspects of ILs applications are outlined where their common features with classical surfactants and definite specificity are of value.

  2. Intramedullary nailing of adult isolated diaphyseal radius fractures.

    PubMed

    Köse, Ahmet; Aydın, Ali; Ezirmik, Naci; Topal, Murat; Can, Cahit Emre; Yılar, Sinan

    2016-03-01

    The aim of the present study was to evaluate functional and cosmetic outcomes of adult patients who underwent intramedullary nailing with newly designed intramedullary radius nails for isolated radius diaphyseal fractures. Seventeen adult patients who had undergone intramedullary nailing for radius diaphyseal fractures were retrospectively evaluated. Patients with isolated radius diaphyseal closed fractures were included. Closed reduction was achieved in all patients. Wrist and elbow ranges of movement were calculated at final follow-up. Grip strength was calculated using a hydraulic hand dynamometer. Maximum radial bowing (MRB) and maximum radial bowing localization (MRBL) were calculated for treated and uninjured arms. Functional evaluation was performed using Grace-Eversman evaluation criteria and Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire score. Of the 17 patients with isolated radius diaphyseal fractures evaluated, 11 (64.7%) were male and 6 (35.3%) were female, with a mean age of 35.76 years (range: 23-61 years). Fractures were right-sided in 11 (64.7%) and left-sided in 6 (35.3%) patients. Mean time to bone union was 10.2 weeks (range: 8-20 weeks). Mean supination was 75.35º (range: 67º-80º), pronation was 85.18º (range: 74º-90º). According to Grace-Eversman evaluation criteria, results were excellent in 16 (94%) and good in 1 (6%) patient. Mean DASH score was 12.58 (3.3-32.5). The gold-standard treatment of adult isolated radius diaphyseal fractures is plate and screw osteosynthesis. However, intramedullary nailing of isolated radius fractures is a good alternative treatment method, with excellent functional results and union rates similar to those of plate and screw osteosynthesis.

  3. Predicting the failure load of the distal radius.

    PubMed

    Muller, Monique E; Webber, Colin E; Bouxsein, Mary L

    2003-06-01

    The distal radius is an important site for the early detection of patients at risk for fracture. Since measuring bone strength in vivo is not possible, we evaluated which bone assessment method of the forearm would best predict failure load of the distal radius and computed a factor of risk for wrist fracture (Phi wrist). Thirty-eight cadaveric forearm specimens were measured by five different techniques to assess bone density, bone mineral content, geometry and trabecular structure at the distal forearm. The bone assessment techniques included dual-energy X-ray absorptiometry (DXA) of the radius, peripheral quantitative computed tomography (pQCT) of the 4% and 20% distal sites of the radius, DXA of the phalanges, digital X-ray radiogrammetry of the forearm (DXR-BMD), and quantitative ultrasound of the radius. The failure load of each excised radius was determined by simulating a fall on an outstretched hand. The pQCT measurements of polar stress-strain index and cortical content explained the greatest portion of variance in failure load (r2=0.82-0.85). Bone mineral content measures were generally better predictors of failure load (r2=0.53-0.85) than the corresponding volumetric or areal bone mineral density values (r2=0.22-0.69) measured by either pQCT or DXA. Multiple regression analysis showed that the addition of a bone geometry measure improved the ability of a bone density measure alone to predict failure load. There was high variability in the ability of different techniques and different variables within a given technique to predict failure load. Estimates of the factor of risk for wrist fracture (Phi wrist) revealed that the women in this study would have been likely to fracture their distal radius upon falling from a standing height (Phi wrist= 1.04), whereas the men would have likely withstood the impact without fracturing their wrist (Phi wrist= 0.79).

  4. The evolution of discharge current and channel radius in cloud-to-ground lightning return stroke process

    NASA Astrophysics Data System (ADS)

    Fan, Tingting; Yuan, Ping; Wang, Xuejuan; Cen, Jianyong; Chang, Xuan; Zhao, Yanyan

    2017-09-01

    The spectra of two negative cloud-to-ground lightning discharge processes with multi-return strokes are obtained by a slit-less high-speed spectrograph, which the temporal resolution is 110 μs. Combined with the synchronous electrical observation data and theoretical calculation, the physical characteristics during return strokes process are analysed. A positive correlation between discharge current and intensity of ionic lines in the spectra is verified, and based on this feature, the current evolution characteristics during four return strokes are investigated. The results show that the time from peak current to the half-peak value estimated by multi point-fitting is about 101 μs-139 μs. The Joule heat in per unit length of four return strokes channel is in the order of 105J/m-106 J/m. The radius of arc discharge channel is positively related to the discharge current, and the more intense the current is, the greater the radius of channel is. Furthermore, the evolution for radius of arc core channel in the process of return stroke is consistent with the change trend of discharge current after the peak value. Compared with the decay of the current, the temperature decreases more slowly.

  5. Hydrogen bonding in ionic liquids.

    PubMed

    Hunt, Patricia A; Ashworth, Claire R; Matthews, Richard P

    2015-03-07

    Ionic liquids (IL) and hydrogen bonding (H-bonding) are two diverse fields for which there is a developing recognition of significant overlap. Doubly ionic H-bonds occur when a H-bond forms between a cation and anion, and are a key feature of ILs. Doubly ionic H-bonds represent a wide area of H-bonding which has yet to be fully recognised, characterised or explored. H-bonds in ILs (both protic and aprotic) are bifurcated and chelating, and unlike many molecular liquids a significant variety of distinct H-bonds are formed between different types and numbers of donor and acceptor sites within a given IL. Traditional more neutral H-bonds can also be formed in functionalised ILs, adding a further level of complexity. Ab initio computed parameters; association energies, partial charges, density descriptors as encompassed by the QTAIM methodology (ρBCP), qualitative molecular orbital theory and NBO analysis provide established and robust mechanisms for understanding and interpreting traditional neutral and ionic H-bonds. In this review the applicability and extension of these parameters to describe and quantify the doubly ionic H-bond has been explored. Estimating the H-bonding energy is difficult because at a fundamental level the H-bond and ionic interaction are coupled. The NBO and QTAIM methodologies, unlike the total energy, are local descriptors and therefore can be used to directly compare neutral, ionic and doubly ionic H-bonds. The charged nature of the ions influences the ionic characteristics of the H-bond and vice versa, in addition the close association of the ions leads to enhanced orbital overlap and covalent contributions. The charge on the ions raises the energy of the Ylp and lowers the energy of the X-H σ* NBOs resulting in greater charge transfer, strengthening the H-bond. Using this range of parameters and comparing doubly ionic H-bonds to more traditional neutral and ionic H-bonds it is clear that doubly ionic H-bonds cover the full range of weak

  6. Correlation between obesity and severity of distal radius fractures.

    PubMed

    Acosta-Olivo, C; Gonzalez-Saldivar, J C; Villarreal-Villarreal, G; Torres-Botello, A; Gomez-Garcia, E; Tamez-Mata, Y; Peña-Martinez, V

    2017-04-01

    The incidence of obesity has increased significantly worldwide. Our hypothesis was that patients with obesity have a more severe distal radius fracture and we realized a study to evaluate this correlation between obesity and severity of distal radius fractures caused by low-energy injuries. A total of 114 patients with distal radius fracture were examined in a cross-sectional, observational study. Fractures were classified according to the international AO-Müller/Orthopedic Trauma Association (AO/OTA) classification in order to determine the severity. The patient's Body Mass Index (BMI) was calculated and a Pearson correlation was performed. The patients were predominantly female, and left side was more frequently affected. Most of the fractures were AO/OTA type A (71 patients). The majority of the involved patients in our study were overweighed or obese. We do not observe a direct correlation between grade of obesity and distal radius fracture severity. Based on the results of this study obesity and severity of distal radius fractures do not correlate. Prognostic. Level IV. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. The radius distribution of planets around cool stars

    SciTech Connect

    Morton, Timothy D.; Swift, Jonathan

    2014-08-10

    We calculate an empirical, non-parametric estimate of the shape of the period-marginalized radius distribution of planets with periods less than 150 days using the small yet well-characterized sample of cool (T{sub eff} < 4000 K) dwarf stars in the Kepler catalog. In particular, we present and validate a new procedure, based on weighted kernel density estimation, to reconstruct the shape of the planet radius function down to radii smaller than the completeness limit of the survey at the longest periods. Under the assumption that the period distribution of planets does not change dramatically with planet radius, we show that the occurrence of planets around these stars continues to increase to below 1 R{sub ⊕}, and that there is no strong evidence for a turnover in the planet radius function. In fact, we demonstrate using many iterations of simulated data that a spurious turnover may be inferred from data even when the true distribution continues to rise toward smaller radii. Finally, the sharp rise in the radius distribution below ∼3 R{sub ⊕} implies that a large number of planets await discovery around cool dwarfs as the sensitivities of ground-based transit surveys increase.

  8. Distal Radius Radiographic Indices and Perilunate Fracture Dislocation

    PubMed Central

    Bagherifard, Abolfazl; Jafari, Davod; Keihan Shokouh, Hassan; Motavallian, Ebrahim; Najd Mazhar, Farid

    2016-01-01

    Background Distal radius radiographic indices may play a role as risk factors in pathogenesis of Kienbock’s disease, scaphoid fracture and nonunion. Perilunate fracture dislocations are devastating wrist injuries, and their relationship and distal radius indices have not been addressed in the literature. Objectives The aim of this study was to evaluate the possible role of distal radius radiographic indices including radial height, radial inclination, ulnar variance and volar tilt as risk factors in the perilunate fracture dislocation injury of the wrist. Patients and Methods We studied distal radius radiographic indices including radial height, radial inclination, ulnar variance and volar tilt in 43 patients with perilunate fracture dislocations and compared them with 44 wrists in the control group. Results The mean values of the radial height, radial inclination, ulnar variance and volar tilt were 12.74 (5 - 18), 24.20 (7 - 35), -0.73 (-5 - 4) and 12.28 (2 - 20) in the patient group. These values were 12.68 (9 - 22), 23.22 (17 - 30), -0.11 (-4 - 3) and 11.05 (-3 - 20), respectively in the control group. There was no statistically significant difference between the two groups. Conclusions This study did not show that distal radius anatomical indices including the radial height, radial inclination, ulnar variance and volar tilt influence perilunate fracture dislocation as risk factors. PMID:27626004

  9. Accuracy of distal radius positioning using an anatomical plate.

    PubMed

    Vroemen, Joy C; Dobbe, Johannes G G; Sierevelt, Inger N; Strackee, Simon D; Streekstra, Geert J

    2013-04-01

    Over the past decade, several anatomical plates have been introduced to improve the result of open reduction and internal fixation of the distal radius. Using 3-dimensional imaging techniques, the authors studied the accuracy and reproducibility of distal radius positioning using anatomical plates.Distal radius fractures and the correction of these fractures were simulated with plastic bone models of radii. The authors simulated a defect by removing an arbitrary wedge shape from the artificial radii. Two surgeons corrected these fractures by placing 2 anatomical plate types according to the plate manufacturers' instructions. The residual positioning errors of the distal segment in relation to the unaffected radii were determined using 3-dimensional imaging and were compared with naturally occurring bilateral radius differences in healthy individuals. In many cases, positioning does not agree with differences based on bilateral asymmetry in healthy patients.This study indicated the accuracy of anatomical plates. Positioning an anatomical plate may lead to considerable residual errors in individual patients. Volar distal radius plate shapes differ among plate manufacturers. Therefore, one plate may perform better than another in an individual.

  10. Evidence for a large radius of the 11Be projectile

    NASA Astrophysics Data System (ADS)

    So, W. Y.; Choi, K. S.; Cheoun, Myung-Ki; Kim, K. S.

    2016-05-01

    We investigate ratios of the elastic scattering cross section to Rutherford cross section, PE, and angular distributions of breakup cross section by using an optical model which exploits various long-range dynamic polarization potentials as well as short-range nuclear bare potentials for the 11Be projectile. From these simultaneous analyses, we extract a large radius of a halo projectile from the experimental data for PE and the angular distribution of the breakup cross section of the 11Be + 64Zn and 11 + 120Sn systems. It results from the fact that a large radius for the long-range nuclear potential is more reasonable for properly explaining these data simultaneously. The extracted reduced interaction radius turns out to be r0=3.18 ˜3.61 fm for 11Be nucleus, which is larger than the conventional value of r0=1.1 ˜1.5 fm used in the standard radius form R =r0A1 /3 . Furthermore, the larger radius as well as the normalization constant N is shown to be important for understanding Coulomb dipole strength distribution.

  11. Optimal network modification for spectral radius dependent phase transitions

    NASA Astrophysics Data System (ADS)

    Rosen, Yonatan; Kirsch, Lior; Louzoun, Yoram

    2016-09-01

    The dynamics of contact processes on networks is often determined by the spectral radius of the networks adjacency matrices. A decrease of the spectral radius can prevent the outbreak of an epidemic, or impact the synchronization among systems of coupled oscillators. The spectral radius is thus tightly linked to network dynamics and function. As such, finding the minimal change in network structure necessary to reach the intended spectral radius is important theoretically and practically. Given contemporary big data resources such as large scale communication or social networks, this problem should be solved with a low runtime complexity. We introduce a novel method for the minimal decrease in weights of edges required to reach a given spectral radius. The problem is formulated as a convex optimization problem, where a global optimum is guaranteed. The method can be easily adjusted to an efficient discrete removal of edges. We introduce a variant of the method which finds optimal decrease with a focus on weights of vertices. The proposed algorithm is exceptionally scalable, solving the problem for real networks of tens of millions of edges in a short time.

  12. Catalytic Ignition of Ionic Liquid Fuels by Ionic Liquids

    DTIC Science & Technology

    2014-07-01

    Francisco, CA, 10-14 Aug 2014. PA#14360 14. ABSTRACT The majority of current hypergolic ionic liquids (ILs) are hypergolic (spontaneous ignition upon...Ignites ( Hypergolic )  Ignites Fast (᝺ms)  Ignites Fast & Green(er) Objectives for Ionic Liquids as Bipropellant Fuels Image: NASA Distribution...oxidizers Established storable fuel/catalyst IL mixtures First demonstration of ignition of non - hypergolic ILs utilizing IL catalysts in H2O2

  13. Ionic Conductivity of Nanostructured Block Copolymer and Ionic Liquid Membranes

    NASA Astrophysics Data System (ADS)

    Hoarfrost, Megan L.; Virgili, Justin M.; Segalman, Rachel A.

    2010-03-01

    Block copolymer and ionic liquid mixtures are of interest for creating ionically conductive, thermally stable, and nanostructured membranes. For mixtures of poly(styrene-b-2-vinylpyridine) (S2VP) and the ionic liquid bis(trifluoromethanesulfonyl)imide ([Im][TFSI]), nanostructured ion-conducting domains are formed due to [Im][TFSI] selectively residing in the P2VP domains of the block copolymer. The dependence of ionic conductivity on temperature, ionic liquid loading, and volume fraction of PS in the neat block copolymer was investigated for membranes with the matrix phase being P2VP/[Im][TFSI]. It was determined that the temperature dependence of conductivity follows the Vogel-Tamman-Fulcher equation, with the activation energy determined by the ratio of [Im][TFSI] to 2VP monomers. The overall weight fraction of [Im][TFSI] in the mixtures, however, is the dominating factor determining conductivity, regardless of PS volume fraction. The insight gained from this work will be important for further investigation into the effect on the ion transport properties of ionic liquids when confined to minority nanostructured domains.

  14. Chiral discrimination by ionic liquids: impact of ionic solutes.

    PubMed

    Brown, Christopher J; Hopkins, Todd A

    2015-04-01

    Chiral ionic liquids hold promise in many asymmetric applications. This study explores the impact of ionic solutes on the chiral discrimination of five amino acid methyl ester-based ionic liquids, including L- and D-alanine methyl ester, L-proline methyl ester, L-leucine methyl ester, and L-valine methyl ester cations combined with bis(trifluoromethanesulfonimide) anion. Circularly polarized luminescence spectroscopy was used to study the chiral discrimination by measuring the racemization equilibrium of a dissymmetric europium complex, Eu(dpa)3(3-) (where dpa = 2,6-pyridinedicarboxylate). The chiral discrimination measured was dependent on the concentration of Eu(dpa)3(3-) and this concentration-dependence was different in each of the ionic liquids. Ionic liquids with L-leucine methyl ester and L-valine methyl ester even switched enantiomeric preference based on the solute concentration. Changing the cation of the Eu(dpa)3(3-) salt from tetrabutylammonium to tetramethylammonium ion also affected the chiral discrimination demonstrated by the ionic liquids.

  15. Effective Potential Theory for Diffusion in Binary Ionic Mixtures

    NASA Astrophysics Data System (ADS)

    Shaffer, Nathaniel R.; Baalrud, Scott D.; Daligault, Jerome

    2016-10-01

    We present theoretical predictions of diffusion coefficients for classical binary ionic mixtures spanning weak to strong coupling. Strongly coupled, classical ionic mixtures are realized in non-neutral plasmas, and they serve as a useful reference system for ultracold plasmas and warm dense matter. We model many-body correlation effects on transport by treating binary interactions via the potential of mean force and by treating the Coulomb hole around each ion with an effective exclusion radius. This approach is known to agree closely with molecular dynamics results for the transport properties of single-component plasmas - including warm dense matter - up to the onset of liquid-like correlations, and we find a comparable range of agreement for the interdiffusion coefficient of binary ionic mixtures. We also present the self-diffusion coefficients of the two ion species in a mixture, in light of recent measurements in ultracold neutral plasmas. An outlook for applying the theory to electron-ion transport in the strong coupling regime is also considered. The authors gratefully acknowledge support from NSF Grant PHY-1453736.

  16. Transport of ferrihydrite nanoparticles in saturated porous media: role of ionic strength and flow rate.

    PubMed

    Tosco, Tiziana; Bosch, Julian; Meckenstock, Rainer U; Sethi, Rajandrea

    2012-04-03

    The use of nanoscale ferrihydrite particles, which are known to effectively enhance microbial degradation of a wide range of contaminants, represents a promising technology for in situ remediation of contaminated aquifers. Thanks to their small size, ferrihydrite nanoparticles can be dispersed in water and directly injected into the subsurface to create reactive zones where contaminant biodegradation is promoted. Field applications would require a detailed knowledge of ferrihydrite transport mechanisms in the subsurface, but such studies are lacking in the literature. The present study is intended to fill this gap, focusing in particular on the influence of flow rate and ionic strength on particle mobility. Column tests were performed under constant or transient ionic strength, including injection of ferrihydrite colloidal dispersions, followed by flushing with particle-free electrolyte solutions. Particle mobility was greatly affected by the salt concentration, and particle retention was almost irreversible under typical salt content in groundwater. Experimental results indicate that, for usual ionic strength in European aquifers (2 to 5 mM), under natural flow condition ferrihydrite nanoparticles are likely to be transported for 5 to 30 m. For higher ionic strength, corresponding to contaminated aquifers, (e.g., 10 mM) the travel distance decreases to few meters. A simple relationship is proposed for the estimation of travel distance with changing flow rate and ionic strength. For future applications to aquifer remediation, ionic strength and injection rate can be used as tuning parameters to control ferrihydrite mobility in the subsurface and therefore the radius of influence during field injections.

  17. Optimizing hydraulic radius and acoustic field of the thermoacoustic engine

    NASA Astrophysics Data System (ADS)

    Kang, Huifang; Li, Qing; Zhou, Gang

    2009-03-01

    It is well known that the acoustic field and the hydraulic radius of the regenerator play key roles in thermoacoustic processes. The optimization of hydraulic radius strongly depends on the acoustic field in the regenerator. This paper investigates the synthetical optimization of the hydraulic radius and the acoustic field which is characterized by the ratio of the traveling wave component over the standing wave component. In this paper, the normalized expressions of acoustic power gain and second law efficiency are derived and calculated, and then some useful calculated results are discussed. Some conclusions have been obtained, which are of significance to explain the optimum work conditions of existing engines and to guide the designs of new thermoacoustic devices. Finally, the operation factor of regenerator is discussed, which is a dimensionless parameter defined in this paper and highly relates to the working condition of the regenerator.

  18. Closed reduction of radius refracture: A case report

    PubMed Central

    Shahid, Mohammad; Yeo, Mildrid; Smibert, John Graham

    2011-01-01

    INTRODUCTION Refractures of the radius and ulna in the paediatric patient with flexible intramedullary nails in situ are known to occur. There are no formal guidelines currently in the literature to guide the management of such fractures. PRESENTATION OF CASE A 10-year-old Caucasian girl, sustained a closed refracture of the radius at the same level, with the flexible intramedullary nails in situ to treat her recent ulna and radius fractures. DISCUSSION We proposed a new non-invasive way of reducing and maintaining such fractures without removal of the bent nail completely. CONCLUSION This method does not significantly reduce the mechanical strength of the nail, as we do not advocate applying an external lateral force, which would compromise nail mechanical strength and eventually lead to breakage of the nail in situ. PMID:22096752

  19. SATELLITE FORMATION :spreading of rings beyond the Roche radius

    NASA Astrophysics Data System (ADS)

    Crida, A.; Charnoz, S.

    2013-11-01

    When a disk of solid particles (like Saturn's rings) spreads beyond the Roche radius (inside which planetary tides prevent aggregation), satellites form and migrate away. After a quick derivation of the Roche radius, here we describe analytically this process. When the spreading is fast, only one large satellite forms, as was the case for Pluto and Earth. When the spreading is slow, a retinue of satellites appear with masses increasing with distance to the Roche radius, in excellent agreement with Saturn's, Uranus', and Neptune's satellite systems. This suggests that Uranus and Neptune used to have massive rings that disappeared to give birth to their regular satellites. Thus, we argue in Crida & Charnoz (2012) that most regular satellites in the Solar System probably formed in this way.

  20. Attractor radius, a new determination criterion of predictability limit

    NASA Astrophysics Data System (ADS)

    Liu, Deqiang; Ding, Ruiqiang; Li, Jianping; Feng, Jie

    2014-05-01

    Firstly, the definition of the attractor radius was given and then the property of that the attractor radius (AR) in a given n-dimensional attractor A is a constant was proved in theory. Secondly, the SV of the square of the RMS difference was separated into two components - the systematic error and the attractor radius, and it was proved that the observed global climatological RMS (OCR) difference is not equal to 71% of the SV of the RMS difference when the systematic error is existed, however, it is always equal to 71% of the AR. Then the physical understanding of the AR and also the predictability limit determinated by it were discussed. Finally, the spatial distributions of the predictability limit calculated from CFSv2 data by different criterions were compared.

  1. Correlation between radius and asphericity in surfaces fitted by conics.

    PubMed

    Pérez-Escudero, Alfonso; Dorronsoro, Carlos; Marcos, Susana

    2010-07-01

    The optical surfaces of the eye are often described in terms of their radius and asphericity. The variations caused by experimental noise in repeated measurements of radius and asphericity of the same surface are strongly correlated. We show this correlation in experimental corneal elevation data from videokeratoscopy and Scheimpflug topography, in non-contact profilometry data of artificial lenses, and in simulations. The effect is a characteristic of the fits to conic curves, and not restricted to any experimental device or fitting procedure. A separate analysis of radius and asphericity may estimate incorrectly the statistical significance of the changes in the ocular surfaces. We propose a MANOVA-based statistical analysis that increases sensitivity by a factor of 4.

  2. Cam radius of curvature modification for improved manufacturability

    SciTech Connect

    Doughty, S.

    1995-12-31

    The design of IC engine cams using the popular polynomial design techniques often results in very high accelerations (and associated high contact forces) as the follower approaches the base circle. In those same parts of the cam action, the cam radius of curvature is likely to change signs, going from convex to concave, and this leads to manufacturing difficulties. When the cam is concave, the radius of the grinding wheel that can be used in manufacture is controlled by the minimum concave radius of curvature of the cam, and this is often much smaller than the wheel size that would result in most economic production. Further, the arc of contact is extended, resulting in loss of coolant flow and rapid loss of wheel dress. A solution is presented, based on substituting a convex circular arc to replace a segment of the cam profile including the concavity. The ramifications of such a modification with regard to the follower motion is also presented.

  3. Novel approaches to ionic chromatography

    SciTech Connect

    Dasgupta, P.K.

    1990-11-01

    Research during this reporting period, continued on ionic chromatography. Major progress has been made towards on-line on-demand generation of ultrapure chemicals by electrochemical means. The concentration of the generated material is governed electrochemically.

  4. Ionic thermoelectric gating organic transistors

    NASA Astrophysics Data System (ADS)

    Zhao, Dan; Fabiano, Simone; Berggren, Magnus; Crispin, Xavier

    2017-01-01

    Temperature is one of the most important environmental stimuli to record and amplify. While traditional thermoelectric materials are attractive for temperature/heat flow sensing applications, their sensitivity is limited by their low Seebeck coefficient (~100 μV K-1). Here we take advantage of the large ionic thermoelectric Seebeck coefficient found in polymer electrolytes (~10,000 μV K-1) to introduce the concept of ionic thermoelectric gating a low-voltage organic transistor. The temperature sensing amplification of such ionic thermoelectric-gated devices is thousands of times superior to that of a single thermoelectric leg in traditional thermopiles. This suggests that ionic thermoelectric sensors offer a way to go beyond the limitations of traditional thermopiles and pyroelectric detectors. These findings pave the way for new infrared-gated electronic circuits with potential applications in photonics, thermography and electronic-skins.

  5. Modeling electrokinetics in ionic liquids.

    PubMed

    Wang, Chao; Bao, Jie; Pan, Wenxiao; Sun, Xin

    2017-03-17

    Using direct numerical simulations, we provide a thorough study regarding the electrokinetics of ionic liquids. In particular, modified Poisson-Nernst-Planck (MPNP) equations are solved to capture the crowding and overscreening effects characteristic of an ionic liquid. For modeling electrokinetic flows in an ionic liquid, the MPNP equations are coupled with Navier-Stokes equations to study the coupling of ion transport, hydrodynamics, and electrostatic forces. Specifically, we consider the ion transport between two parallel charged surfaces, charging dynamics in a nanopore, capacitance of electric double-layer capacitors, electro-osmotic flow in a nanochannel, electroconvective instability on a plane ion-selective surface, and electroconvective flow on a curved ion-selective surface. We also discuss how crowding and overscreening and their interplay affect the electrokinetic behaviors of ionic liquids in these application problems. This article is protected by copyright. All rights reserved.

  6. Ionic Liquid Crystals: Versatile Materials.

    PubMed

    Goossens, Karel; Lava, Kathleen; Bielawski, Christopher W; Binnemans, Koen

    2016-04-27

    This Review covers the recent developments (2005-2015) in the design, synthesis, characterization, and application of thermotropic ionic liquid crystals. It was designed to give a comprehensive overview of the "state-of-the-art" in the field. The discussion is focused on low molar mass and dendrimeric thermotropic ionic mesogens, as well as selected metal-containing compounds (metallomesogens), but some references to polymeric and/or lyotropic ionic liquid crystals and particularly to ionic liquids will also be provided. Although zwitterionic and mesoionic mesogens are also treated to some extent, emphasis will be directed toward liquid-crystalline materials consisting of organic cations and organic/inorganic anions that are not covalently bound but interact via electrostatic and other noncovalent interactions.

  7. Additive polarizabilities in ionic liquids.

    PubMed

    Bernardes, Carlos E S; Shimizu, Karina; Lopes, José Nuno Canongia; Marquetand, Philipp; Heid, Esther; Steinhauser, Othmar; Schröder, Christian

    2016-01-21

    An extended designed regression analysis of experimental data on density and refractive indices of several classes of ionic liquids yielded statistically averaged atomic volumes and polarizabilities of the constituting atoms. These values can be used to predict the molecular volume and polarizability of an unknown ionic liquid as well as its mass density and refractive index. Our approach does not need information on the molecular structure of the ionic liquid, but it turned out that the discrimination of the hybridization state of the carbons improved the overall result. Our results are not only compared to experimental data but also to quantum-chemical calculations. Furthermore, fractional charges of ionic liquid ions and their relation to polarizability are discussed.

  8. Special Report: Solid Ionic Conductors.

    ERIC Educational Resources Information Center

    Shriver, Duward F.; Farrington, Gregory C.

    1985-01-01

    Solid ionic conductors are unusual materials that may find valuable applications in devices ranging from high-energy density batteries to lasers. The nature of these materials and their potential uses are discussed. (JN)

  9. Ionic thermoelectric gating organic transistors

    PubMed Central

    Zhao, Dan; Fabiano, Simone; Berggren, Magnus; Crispin, Xavier

    2017-01-01

    Temperature is one of the most important environmental stimuli to record and amplify. While traditional thermoelectric materials are attractive for temperature/heat flow sensing applications, their sensitivity is limited by their low Seebeck coefficient (∼100 μV K−1). Here we take advantage of the large ionic thermoelectric Seebeck coefficient found in polymer electrolytes (∼10,000 μV K−1) to introduce the concept of ionic thermoelectric gating a low-voltage organic transistor. The temperature sensing amplification of such ionic thermoelectric-gated devices is thousands of times superior to that of a single thermoelectric leg in traditional thermopiles. This suggests that ionic thermoelectric sensors offer a way to go beyond the limitations of traditional thermopiles and pyroelectric detectors. These findings pave the way for new infrared-gated electronic circuits with potential applications in photonics, thermography and electronic-skins. PMID:28139738

  10. Ionic Liquid Epoxy Resin Monomers

    NASA Technical Reports Server (NTRS)

    Paley, Mark S. (Inventor)

    2013-01-01

    Ionic liquid epoxide monomers capable of reacting with cross-linking agents to form polymers with high tensile and adhesive strengths. Ionic liquid epoxide monomers comprising at least one bis(glycidyl) N-substituted nitrogen heterocyclic cation are made from nitrogen heterocycles corresponding to the bis(glycidyl) N-substituted nitrogen heterocyclic cations by a method involving a non-nucleophilic anion, an alkali metal cation, epichlorohydrin, and a strong base.

  11. Ionic emission from Taylor cones

    NASA Astrophysics Data System (ADS)

    Castro Reina, Sergio

    Electrified Taylor cones have been seen as an efficient way to generate thrust for space propulsion. Especially the pure ionic regime (PIR) combines a very high specific impulse (thrust per unit mass) and efficiency, which is very important to reduce fuel transportation costs. The PIR has been primarily based on electrosprays of liquid metals [Swatik and Hendricks 1968, Swatik 1969]. However, emissions dominated by or containing exclusively ions have also been observed from nonmetallic purely ionic substances, initially sulfuric acid [Perel et al. 1969], and more recently room temperature molten salts referred to as ionic liquids (ILs) [Romero-Sanz et al. 2003]. The recent use of the liquid metal ion source (LMIS) with ILs, becoming this "new" source to be known as ionic liquid ion source (ILIS) [Lozano and Martinez-Sanchez 2005], has shown important differences on the emission from Taylor cones with the traditional hollow capillary. This new source seems to be more flexible than the capillary [Paulo, Sergio, carlos], although its low emission level (low thrust) is an important drawback from the space propulsion point of view. Throughout the thesis I have studied some aspects of the ionic emission from ionic liquid Taylor cones and the influence of the properties of the liquids and the characteristic of source on the emission. I have unraveled the reason why ILIS emits such low currents (˜200 nA) and found a way to solve this problem increasing the current up to capillary levels (˜1000 nA) [Castro and Fernandez de la Mora 2009]. I have also tried to reduce ion evaporation while reducing the emitted droplet size in order to increase the thrust generated while keeping the efficiency relatively high and I have measured the energy of evaporation of several cations composing ionic liquids, mandatory step to understand ionic evaporation.

  12. Biopolymer Processing Using Ionic Liquids

    DTIC Science & Technology

    2014-08-07

    AFRL-OSR-VA-TR-2014-0181 (YIP-11) BIOPOLYMER PROCESSING USING IONIC LIQUIDS William Reichert UNIVERSITY OF SOUTH ALABAMA 08/07/2014 Final Report...3. DATES COVERED (From - To) May 2011-May 2014 4. TITLE AND SUBTITLE iopolymer Processing using Ionic Liquids for Feedstock Chemicals 5a...reaction and degradation products of the conversion of chitin and chitosan, and 3) investigate the effects of various reaction conditions, such as

  13. Future treatment and research directions in distal radius fracture.

    PubMed

    Jupiter, Jesse

    2012-05-01

    Whether or not they will have their lives dramatically extended in the next few decades, it is clear that people are living longer, healthier, and more active lives. The two peak incidences of distal radius fractures will remain within the pediatric and geriatric age groups, with the latter experiencing a substantial increase in the coming years. This article attempts to project future developments with regard to epidemiology, risk and prevention, fracture assessment, and treatment of distal radius fractures, and the ever increasing concern for the economic impact of this prevalent injury. Copyright © 2012. Published by Elsevier Inc.

  14. Defining the air sparging radius of influence for groundwater remediation

    NASA Astrophysics Data System (ADS)

    McCray, John E.; Falta, Ronald W.

    1996-10-01

    A theoretical study of air sparging for the removal of volatile organic compounds (VOCs) from groundwater is presented. A simple relationship is developed between the observed subsurface pressure increase due to sparging and the gas saturation at that location, thus providing a quantitative measure of the sparging radius of influence. Multiphase numerical simulations using a radially symmetric cylindrical geometry are used to confirm this relation, and to relate the injected gas radius of influence to the zone of VOC cleanup during sparging. These simulations also illustrate the transient and steady-state behavior of air sparging systems in both homogeneous and heterogeneous systems.

  15. Proton Charge Radius (PRad) Experiment at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Peng, C.; Gao, H.

    2016-03-01

    The puzzle of proton charge radius was recently raised by the measurement of muonic hydrogen Lamb shift at Paul Scherrer Institute (PSI), whose results were seven standard deviations smaller than the CODATA recommended value. To investigate this discrepancy, the PRad experiment was proposed and approved at Thomas Jefferson National Accelerator Facility (JLab). The experiment will extract the proton charge radius with a sub-percent accuracy by measuring the cross-sections of unpolarized electronproton elastic scattering in an unprecedented low Q2 region (2×10-4 GeV2/c2).

  16. Radius Constants for Analytic Functions with Fixed Second Coefficient

    PubMed Central

    Nargesi, Mahnaz M.; Ali, Rosihan M.; Ravichandran, V.

    2014-01-01

    Let f(z) = z + ∑n=2∞anzn be analytic in the unit disk with the second coefficient a2 satisfying |a2 | = 2b, 0 ≤ b ≤ 1. Sharp radius of Janowski starlikeness is obtained for functions f whose nth coefficient satisfies |an | ≤ cn + d  (c, d ≥ 0) or |an | ≤ c/n  (c > 0  and  n ≥ 3). Other radius constants are also obtained for these functions, and connections with earlier results are made. PMID:25101327

  17. Calorimetric and Neutron Scattering Studies on Glass Transitions and Ionic Diffusions in Imidazolium-based Ionic Liquids

    NASA Astrophysics Data System (ADS)

    Yamamuro, O.; Kofu, M.

    2017-05-01

    Glass transition is one of the central research issues of ionic liquids (ILs). In particular, the most typical ILs, imidazolium-basedones (ImILs) are readily supercooled and exhibit glass transitions below room temperature. We have measured the heat capacities of several ImILs, encoded as CnmimX (n: alkyl carbon number, n = 2-8, X: anion, X = Cl, I, FeCl4, TFSI) using an adiabatic calorimeter. We found that most of ImILs exhibit glass transitions with large Cp jumps in a temperature range between 170 K and 230 K. The large Cp jumps reflect that these ILs are fragile liquids that exhibit large structural change depending on temperature near the glass transition temperature T g. It is also revealed that T g does not depend much on n but on the anion radius. We have investigated the dynamics of CnmimX (n = 2-8, X = Cl, NO3, PF6, TF, FSI, TFSI) by means of a quasielastic neutron scattering (QENS) technique. It was clarified that the ionic diffusion is directly associated with the viscosity and glass transition. The activation energy ΔE a of the ionic diffusion increases with decreasing anion size but remains almost unchanged with n as found for T g. These systematic change of T g and ΔE a can be explained well by taking account the nano-domain structure which is the most characteristic feature of ImILs.

  18. Nanoconfined Ionic Liquids.

    PubMed

    Zhang, Shiguo; Zhang, Jiaheng; Zhang, Yan; Deng, Youquan

    2016-12-29

    Ionic liquids (ILs) have been widely investigated as novel solvents, electrolytes, and soft functional materials. Nevertheless, the widespread applications of ILs in most cases have been hampered by their liquid state. The confinement of ILs into nanoporous hosts is a simple but versatile strategy to overcome this problem. Nanoconfined ILs constitute a new class of composites with the intrinsic chemistries of ILs and the original functions of solid matrices. The interplay between these two components, particularly the confinement effect and the interactions between ILs and pore walls, further endows ILs with significantly distinct physicochemical properties in the restricted space compared to the corresponding bulk systems. The aim of this article is to provide a comprehensive review of nanoconfined ILs. After a brief introduction of bulk ILs, the synthetic strategies and investigation methods for nanoconfined ILs are documented. The local structure and physicochemical properties of ILs in diverse porous hosts are summarized in the next sections. The final section highlights the potential applications of nanoconfined ILs in diverse fields, including catalysis, gas capture and separation, ionogels, supercapacitors, carbonization, and lubrication. Further research directions and perspectives on this topic are also provided in the conclusion.

  19. Sonofragmentation of Ionic Crystals.

    PubMed

    Kim, Hyo Na; Suslick, Kenneth S

    2017-02-24

    Mechanochemistry deals with the interface between the chemical and the mechanical worlds and explores the physical and chemical changes in materials caused by an input of mechanical energy. As such, the chemical and physical effects of ultrasound, i.e., sonochemistry, are forms of mechanochemistry. In this paper, the fragmentation of ionic crystals during ultrasonic irradiation of slurries has been quantitatively investigated: the rate of fragmentation depends strongly on the strength of the materials (as measured by Vickers hardness or by Young's modulus). This is a mechanochemical extension of the Bell-Evans-Polanyi Principle or Hammond's Postulate: activation energies for solid fracture correlate with binding energies of solids. Sonofragmentation is unaffected by slurry loading or liquid vapor pressure, but is suppressed by increasing liquid viscosity. The mechanism of the particle breakage is consistent with a direct interaction between the shockwaves created by the ultrasound (through acoustic cavitation) and the solid particles in the slurry. Fragmentation is proposed to occur from defects in the solids induced by compression-expansion, bending, or torsional distortions of the crystals.

  20. Hydrophobic ionic liquids

    DOEpatents

    Koch, V.R.; Nanjundiah, C.; Carlin, R.T.

    1998-10-27

    Ionic liquids having improved properties for application in non-aqueous batteries, electrochemical capacitors, electroplating, catalysis and chemical separations are disclosed. Exemplary compounds have one of the following formulas shown in a diagram wherein R{sub 1}, R{sub 2}, R{sub 3}, R{sub 4}, R{sub 5}, and R{sub 6} are either H; F; separate alkyl groups of from 1 to 4 carbon atoms, respectively, or joined together to constitute a unitary alkylene radical of from 2 to 4 carbon atoms forming a ring structure converging on N; or separate phenyl groups; and wherein the alkyl groups, alkylene radicals or phenyl groups may be substituted with electron withdrawing groups, preferably F-, Cl-, CF{sub 3}-, SF{sub 5}-, CF{sub 3}S-, (CF{sub 3}){sub 2}CHS- or (CF{sub 3}){sub 3}CS-; and X{sup {minus}} is a non-Lewis acid-containing polyatomic anion having a van der Waals volume exceeding 100 {angstrom}{sup 3}. 4 figs.

  1. Hydrophobic ionic liquids

    DOEpatents

    Koch, Victor R.; Nanjundiah, Chenniah; Carlin, Richard T.

    1998-01-01

    Ionic liquids having improved properties for application in non-aqueous batteries, electrochemical capacitors, electroplating, catalysis and chemical separations are disclosed. Exemplary compounds have one of the following formulas: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are either H; F; separate alkyl groups of from 1 to 4 carbon atoms, respectively, or joined together to constitute a unitary alkylene radical of from 2 to 4 carbon atoms forming a ring structure converging on N; or separate phenyl groups; and wherein the alkyl groups, alkylene radicals or phenyl groups may be substituted with electron withdrawing groups, preferably F--, Cl--, CF.sub.3 --, SF.sub.5 --, CF.sub.3 S--, (CF.sub.3).sub.2 CHS-- or (CF.sub.3).sub.3 CS--; and X.sup.- is a non-Lewis acid-containing polyatomic anion having a van der Waals volume exceeding 100 .ANG..sup.3.

  2. Hydrophobic ionic liquids

    SciTech Connect

    Koch, V.R.; Nanjundiah, C.; Carlin, R.T.

    1998-10-27

    Ionic liquids having improved properties for application in non-aqueous batteries, electrochemical capacitors, electroplating, catalysis and chemical separations are disclosed. Exemplary compounds have one of the following formulas shown in a diagram wherein R{sub 1}, R{sub 2}, R{sub 3}, R{sub 4}, R{sub 5}, and R{sub 6} are either H; F; separate alkyl groups of from 1 to 4 carbon atoms, respectively, or joined together to constitute a unitary alkylene radical of from 2 to 4 carbon atoms forming a ring structure converging on N; or separate phenyl groups; and wherein the alkyl groups, alkylene radicals or phenyl groups may be substituted with electron withdrawing groups, preferably F-, Cl-, CF{sub 3}-, SF{sub 5}-, CF{sub 3}S-, (CF{sub 3}){sub 2}CHS- or (CF{sub 3}){sub 3}CS-; and X{sup {minus}} is a non-Lewis acid-containing polyatomic anion having a van der Waals volume exceeding 100 {angstrom}{sup 3}. 4 figs.

  3. About the horizontal variability of effective radius in stratocumulus clouds

    NASA Astrophysics Data System (ADS)

    Magaritz-Ronen, L.; Khain, A.; Pinsky, M.

    2016-08-01

    The role of turbulent mixing in formation of low horizontal variability of effective radius near the top of nondrizzling stratocumulus clouds is investigated in simulations of clouds observed during the Second Dynamics and Chemistry of Marine Stratocumulus field experiment. The clouds are simulated using a spectral bin microphysics Lagrangian-Eulerian model consisting of ~2000 adjacent parcels moving in a turbulence-like field with observed correlation properties. The parcels interact through drop sedimentation and turbulent mixing. It was found that the effective radius variability in the horizontal direction near cloud top does not exceed ~10% of the averaged value. Three different types of cloud parcels are revealed to be differently influenced by mixing: ascending slightly diluted parcels, cloudy parcels experiencing intense mixing with parcels from inversion, and initially dry parcels. The evolution of droplet size distributions in parcels belonging to these types is investigated. It is shown that in parcels of the first two types the values of effective radii do not change or change only slightly remaining close to the adiabatic value. In initially droplet-free parcels effective radius rapidly reaches a value close to the adiabatic value, while liquid water content remains low. Therefore, turbulent mixing leads to establishing vertical profiles of effective radius, which are close to the adiabatic profile.

  4. Computational Analysis of Dual Radius Circulation Control Airfoils

    NASA Technical Reports Server (NTRS)

    Lee-Rausch, E. M.; Vatsa, V. N.; Rumsey, C. L.

    2006-01-01

    The goal of the work is to use multiple codes and multiple configurations to provide an assessment of the capability of RANS solvers to predict circulation control dual radius airfoil performance and also to identify key issues associated with the computational predictions of these configurations that can result in discrepancies in the predicted solutions. Solutions were obtained for the Georgia Tech Research Institute (GTRI) dual radius circulation control airfoil and the General Aviation Circulation Control (GACC) dual radius airfoil. For the GTRI-DR airfoil, two-dimensional structured and unstructured grid computations predicted the experimental trend in sectional lift variation with blowing coefficient very well. Good code to code comparisons between the chordwise surface pressure coefficients and the solution streamtraces also indicated that the detailed flow characteristics were matched between the computations. For the GACC-DR airfoil, two-dimensional structured and unstructured grid computations predicted the sectional lift and chordwise pressure distributions accurately at the no blowing condition. However at a moderate blowing coefficient, although the code to code variation was small, the differences between the computations and experiment were significant. Computations were made to investigate the sensitivity of the sectional lift and pressure distributions to some of the experimental and computational parameters, but none of these could entirely account for the differences in the experimental and computational results. Thus, CFD may indeed be adequate as a prediction tool for dual radius CC flows, but limited and difficult to obtain two-dimensional experimental data prevents a confident assessment at this time.

  5. Finite Larmor radius flute mode theory with end loss

    SciTech Connect

    Kotelnikov, I.A.; Berk, H.L.

    1993-08-01

    The theory of flute mode stability is developed for a two-energy- component plasma partially terminated by a conducting limiter. The formalism is developed as a preliminary study of the effect of end-loss in open-ended mirror machines where large Larmor radius effects are important.

  6. Ultrasound-Guided Reduction of Distal Radius Fractures

    PubMed Central

    Sabzghabaei, Anita; Shojaee, Majid; Arhami Dolatabadi, Ali; Manouchehrifar, Mohammad; Asadi, Mahdi

    2016-01-01

    Introduction: Distal radius fractures are a common traumatic injury, particularly in the elderly population. In the present study we examined the effectiveness of ultrasound guidance in the reduction of distal radius fractures in adult patients presenting to emergency department (ED). Methods: In this prospective case control study, eligible patients were adults older than 18 years who presented to the ED with distal radius fractures. 130 consecutive patient consisted of two group of Sixty-Five patients were prospectively enrolled for around 1 years. The first group underwent ultrasound-guided reduction and the second (control group) underwent blind reduction. All procedures were performed by two trained emergency residents under supervision of senior emergency physicians. Results: Baseline characteristics between two groups were similar. The rate of repeat reduction was reduced in the ultrasound group (9.2% vs 24.6%; P = .019). The post reduction radiographic indices were similar between the two groups, although the ultrasound group had improved volar tilt (mean, 7.6° vs 3.7°; P = .000). The operative rate was reduced in the ultrasound groups (10.8% vs 27.7%; P = .014). Conclusion: Ultrasound guidance is effective and recommended for routine use in the reduction of distal radius fractures. PMID:27299141

  7. Intrafocal pinning for distal radius metaphyseal fractures in children.

    PubMed

    Parikh, Shital N; Jain, Viral V; Youngquist, Jeffrey

    2013-06-01

    The purpose of this retrospective case control study was to evaluate the results of intrafocal pinning for distal radius metaphyseal fractures in children and to compare these results with conventional pinning. Data were collected from medical records and radiographs from patients who underwent closed reduction and percutaneous pinning for distal radius fracture in a Level I trauma center at the authors' institution between 2008 and 2010. Inclusion criteria included a dorsally angulated metaphyseal fracture without physeal involvement, an open distal radius physis, and a follow-up to radiographic union. A total of 10 patients with intrafocal pinning were compared to 26 patients with conventional pinning. Preoperatively, angulation was greater in patients who received intrafocal pinning than conventional pinning based on anteroposterior radiographs. Postoperatively, the 2 groups did not differ in angulation on either anteroposterior or lateral radiographs. One malunion and 2 pin-related complications occurred in the conventional pinning group, and 1 pin-related complication occurred in the intrafocal pinning group. The 2 groups did not differ by age, sex, side of injury, days to surgery, or initial shortening. This study affirms that the intrafocal pinning technique is an alternative to the conventional pinning technique for the stabilization of displaced metaphyseal distal radius fractures in children. Intrafocal pinning can also be used as a reduction tool for fractures that cannot be reduced by closed manipulation. The complications are comparable between the 2 techniques.

  8. Nonlinear buckling analyses of a small-radius carbon nanotube

    NASA Astrophysics Data System (ADS)

    Liu, Ning; Wang, Yong-Gang; Li, Min; Jia, Jiao

    2014-04-01

    Carbon nanotube (CNT) was first discovered by Sumio Iijima. It has aroused extensive attentions of scholars from all over the world. Over the past two decades, we have acquired a lot of methods to synthesize carbon nanotubes and learn their many incredible mechanical properties such as experimental methods, theoretical analyses, and computer simulations. However, the studies of experiments need lots of financial, material, and labor resources. The calculations will become difficult and time-consuming, and the calculations may be even beyond the realm of possibility when the scale of simulations is large, as for computer simulations. Therefore, it is necessary for us to explore a reasonable continuum model, which can be applied into nano-scale. This paper attempts to develop a mathematical model of a small-radius carbon nanotube based on continuum theory. An Isotropic circular cross-section, Timoshenko beam model is used as a simplified mechanical model for the small-radius carbon nanotube. Theoretical part is mainly based on modified couple stress theory to obtain the numerical solutions of buckling deformation. Meanwhile, the buckling behavior of the small radius carbon nanotube is simulated by Molecular Dynamics method. By comparing with the numerical results based on modified couple stress theory, the dependence of the small-radius carbon nanotube mechanical behaviors on its elasticity constants, small-size effect, geometric nonlinearity, and shear effect is further studied, and an estimation of the small-scale parameter of a CNT (5, 5) is obtained.

  9. Effects of rare earth ionic doping on microstructures and electrical properties of CaCu{sub 3}Ti{sub 4}O{sub 12} ceramics

    SciTech Connect

    Xue, Renzhong; Chen, Zhenping; Dai, Haiyang; Liu, Dewei; Li, Tao; Zhao, Gaoyang

    2015-06-15

    Graphical abstract: The dielectric constant decreases monotonically with reduced RE doping ion radius and is more frequency independent compared with that of pure CCTO sample. - Highlights: • The mean grain sizes decrease monotonically with reduced RE doping ionic radius. • Doping gives rise to the monotonic decrease of ϵ{sub r} with reduced RE ionic radius. • The nonlinear coefficient and breakdown field increase with RE ionic doping. • α of all the samples is associated with the potential barrier width rather than Φ{sub b}. - Abstract: Ca{sub 1–x}R{sub x}Cu{sub 3}Ti{sub 4}O{sub 12}(R = La, Nd, Eu, Gd, Er; x = 0 and 0.005) ceramics were prepared by the conventional solid-state method. The influences of rare earth (RE) ion doping on the microstructure, dielectric and electrical properties of CaCu{sub 3}Ti{sub 4}O{sub 12} (CCTO) ceramics were investigated systematically. Single-phase formation is confirmed by XRD analyses. The mean grain size decreases monotonically with reduced RE ion radius. The EDS results reveal that RE ionic doping reduces Cu-rich phase segregation at the grain boundaries (GBs). Doping gives rise to the monotonic decrease of dielectric constant with reduced RE ionic radius but significantly improves stability with frequency. The lower dielectric loss of doped samples is obtained due to the increase of GB resistance. In addition, the nonlinear coefficient and breakdown field increase with RE ionic doping. Both the fine grains and the enhancement of potential barrier at GBs are responsible for the improvement of the nonlinear current–voltage properties in doped CCTO samples.

  10. OBSERVATIONAL CONSTRAINTS ON THE DEGENERATE MASS-RADIUS RELATION

    SciTech Connect

    Holberg, J. B.; Oswalt, T. D.; Barstow, M. A. E-mail: toswalt@fit.edu

    2012-03-15

    The white dwarf mass-radius relationship is fundamental to modern astrophysics. It is central to routine estimation of DA white dwarf masses derived from spectroscopic temperatures and gravities. It is also the basis for observational determinations of the white dwarf initial-final-mass relation. Nevertheless, definitive and detailed observational confirmations of the mass-radius relation (MRR) remain elusive owing to a lack of sufficiently accurate white dwarf masses and radii. Current best estimates of masses and radii allow only broad conclusions about the expected inverse relation between masses and radii in degenerate stars. In this paper, we examine a restricted set of 12 DA white dwarf binary systems for which accurate (1) trigonometric parallaxes, (2) spectroscopic effective temperatures and gravities, and (3) gravitational redshifts are available. We consider these three independent constraints on mass and radius in comparison with an appropriate evolved MRR for each star. For the best-determined systems it is found that the DA white dwarfs conform to evolve theoretical MRRs at the 1{sigma} to 2{sigma} level. For the white dwarf 40 Eri B (WD 0413-077) we find strong evidence for the existence of a 'thin' hydrogen envelope. For other stars improved parallaxes will be necessary before meaningful comparisons are possible. For several systems current parallaxes approach the precision required for the state-of-the-art mass and radius determinations that will be obtained routinely from the Gaia mission. It is demonstrated here how these anticipated results can be used to firmly constrain details of theoretical mass-radius determinations.

  11. Unstable Distal Radius Fractures Treated by Volar Locking Anatomical Plates

    PubMed Central

    Jose, Anto; Deniese, Pascal Noel; Babu, Abey Thomas; Rengasamy, Kanagasabai; Najimudeen, Syed

    2017-01-01

    Introduction Fracture of the distal end of radius represents the most common fracture of the upper extremity accounting for 16-20% of all fractures. Plating is now emerging as the gold standard for management of distal radius fractures due to increased rate of complications such as malunion, subluxation/dislocation of distal radio-ulnar joint or late collapse of fracture. Procedures such as closed reduction and cast immobilization, ligamentotaxis with external fixator and percutaneous pin fixation are no longer acceptable. Aim The purpose of the study was to evaluate the functional and radiological outcome of unstable distal radius fractures treated with the volar locking plate. Materials and Methods We reviewed 53 patients from January 2011 to December 2015, treated for unstable distal radius fractures using a volar locking compression plate. Standard radiographic and clinical assessment after 12 months (range 12-16 months) were measured and final functional and radiological outcome were assessed using the Modified Mayo wrist scoring system and Sarmiento’s modification of Lindstorm criteria respectively. Results There were 42 males and 11 females with an average age of 39.12±31.78 years (18-71 years). At the end of 12 months, 36 patients had an excellent radiological outcome and 10 patients had good radiological outcome as per Sarmiento’s modification of Lindstorm criteria. Eleven patients had an excellent functional outcome and 26 patients had a good functional outcome as per modified Mayo wrist scoring system. There was one case of superficial wound infection which subsided with intravenous antibiotics. Conclusion The volar locking plate fixation helps in early mobilization of the wrist, restores anatomy, allows early return to function, prevents secondary loss of reduction and hence is an effective treatment for unstable fractures of the distal radius. PMID:28274009

  12. Multilayer ionic polymer transducer

    NASA Astrophysics Data System (ADS)

    Akle, Barbar J.; Leo, Donald J.

    2003-07-01

    A transducer consisting of multiple layers of ionic polymer material is developed for applications in sensing, actuation, and control. The transducer consists of two to four individual layers each approximately 200 microns thick. The transducers are connected in parallel to minimize the electric field requirements for actuation. The tradeoff in deflection and force can be controlled by controlling the mechanical constraint at the interface. Packaging the transducer in an outer coating produces a hard constraint between layers and reduces the deflection with a force that increases linearly with the number of layers. This configuration also increases the bandwidth of the transducer. Removing the outer packaging produces an actuator that maintains the deflection of a single layer but has an increased force output. This is obtained by allowing the layers to slide relative to one another during bending. Experiments on transducers with one to three layers are performed and the results are compared to Newbury"s equivalent circuit model, which was modified to accommodate the multilayer polymers. The modification was performed on four different boundary conditions, two electrical the series and the parallel connection, and two mechanical the zero interfacial friction and the zero slip on the interface. Results demonstrate that the largest obstacle to obtaining good performance is water transport between the individual layers. Water crossover produces a near short circuit electrical condition and produces feedthrough between actuation layers and sensing layers. Electrical feedthrough due to water crossover eliminates the ability to produce a transducer that has combined sensing and actuation properties. Eliminating water crossover through good insulation enables the development of a small (5 mm x 30 mm) transducer that has sensing and actuation bandwidth on the order of 100 Hz.

  13. Dual Ionic and Organic Nature of Ionic Liquids

    PubMed Central

    Shi, Rui; Wang, Yanting

    2016-01-01

    Inherited the advantages of inorganic salts and organic solvents, ionic liquids (ILs) exhibit many superior properties allowing them promising green solvents for the future. Although it has been widely acknowledged that the unique features of ILs originate from their dual ionic and organic nature, its microscopic physical origin still remains blurry. In this work, by comparing the ion/molecule cage structures obtained from molecular dynamics simulations for seven prototypic liquids—a molten inorganic salt, four ILs, a strongly polar organic solvent, and a weakly polar organic solvent, we have revealed that the depth of the cage energy landscape characterizes the ionic nature of ILs, whereas the slope and curvature of its mimimum determine the organic nature of ILs. This finding advances our understanding of ILs and thus will help their efficient utilization as well as the systematic design of novel functionalized ILs. PMID:26782660

  14. Dual Ionic and Organic Nature of Ionic Liquids.

    PubMed

    Shi, Rui; Wang, Yanting

    2016-01-19

    Inherited the advantages of inorganic salts and organic solvents, ionic liquids (ILs) exhibit many superior properties allowing them promising green solvents for the future. Although it has been widely acknowledged that the unique features of ILs originate from their dual ionic and organic nature, its microscopic physical origin still remains blurry. In this work, by comparing the ion/molecule cage structures obtained from molecular dynamics simulations for seven prototypic liquids--a molten inorganic salt, four ILs, a strongly polar organic solvent, and a weakly polar organic solvent, we have revealed that the depth of the cage energy landscape characterizes the ionic nature of ILs, whereas the slope and curvature of its mimimum determine the organic nature of ILs. This finding advances our understanding of ILs and thus will help their efficient utilization as well as the systematic design of novel functionalized ILs.

  15. Coordination chemistry of several radius-sensitive complexones and applications to lanthanide-actinide separations

    SciTech Connect

    Potter, M.W.

    1981-10-01

    The relationships between the lanthanide complex formation equilibria and the lanthanide-actinide separation application of three radius sensitive ligands have been studied. The consecutive stepwise formation constants of the 1:1, 2:1, and 3:1 chelate species formed by the interaction of DHDMB and the tripositive lanthanides and yttrium were determined potentiometrically at 0.1 M ionic strength and 25/sup 0/C. Results indicate that three different coordination modes, one tridentate and two bidentate are in evidence. Tracer level /sup 241/Am - /sup 155/Eu cation-exchange experiments utilizing DHDMB eluents indicate that this dihydroxycarboxylate does not form a sufficiently strong americium complex to elute that actinide ahead of europium. The overall stability of the americium 3:1 complex appears intermediate between samarium and europium. Cation-exchange elutions of /sup 241/Am, /sup 155/Eu, and /sup 160/Tb mixtures with EEDTA solutions prove that the EEDTA ligand is capable of eluting americium ahead of all of the tripositive lanthanide cations. The minimum separation occurs with terbium, where the Am-Tb separation factor is 1.71. 1,5-diaminopentane-N,N,N',N'-tetraacetic acid (PMDTA) was synthesized using cation exchange. A mathematical method was developed for the formation constants of the protonated and unprotonated lanthanide-PMDTA complexes from potentiometry. Cation-exchange elutions of tracer quantities of Am, Eu, and Tb revealed that terbium is eluted ahead of both americium and europium.

  16. Recrystallized quinolinium ionic liquids for electrochemical analysis

    NASA Astrophysics Data System (ADS)

    Selvaraj, Gowri; Wilfred, Cecilia Devi; Eang, Neo Kian

    2016-11-01

    Ionic liquids have received a lot of attention due to their unique properties. In this work the prospect of quinolinium based ionic liquids as electrolyte for dye sensitised solar cell were tested using cyclic voltammetry. The results have shown electron transfer in the ionic liquid without undergoing any permanent chemical changes. Prior to testing, the ionic liquids were purified through recrystallization as electrochemical properties of ionic liquids are highly dependent on the purity of the ionic liquids. This results have shone new light for this work.

  17. Variable radius cartography - History and perspectives of a new discipline

    NASA Astrophysics Data System (ADS)

    Scalera, Giancarlo

    2014-05-01

    The map that Toscanelli sent to Columbus was an unconscious application of cartography at a smaller radius than the real. The first really conscious attempts to represent the geography of Earth on globes of radius less than the current one occurred after the formulation of the concept of expanding Earth through geological time. The American chemist and geologist Richard Owen (1810-1890) in his book Key to the geology of the globe (1857) described the principles of what he himself called Anatomical Geology, with the Earth growing as a biological organism. The book contained a global paleogeographic map of the Earth that would have had a radius of about 4000 kilometers. In 1928 J.A.H. Kerkhoff (under the pseudonym Aero-dilettant) published a series of paleogeographic globes on which the modern oceans disappeared. With the same artisan methods of transfer continental outlines from a sphere to a smaller one, in 1933 O.C. Hilgenberg represented three different geological epochs, and, later, for the first time mapped paleopoles with their site-pole segments of meridian. Even today the traditional method of Hilgenberg is followed by senior researchers (Klaus Vogel, 2003) and younger geologists (James Maxlow). In England Hugh Owen applied the methods of traditional cartography to the variable radius one. His Atlas of Continental Displacement was in the 70s and 80s, for this discipline, a real milestone. While in the field of constant radius paleogeography the adherents to plate tectonics created many computer codes of automatic mapping (Bullard et al., 1965; Smith & Hallam, 1970; Scotese et al., 1979; and many others), in the variable radius field few tried to reach the same task. In 1972 in United States a first very simple attempt (but was not further developed) came from a private, R.B. Perry, followed by the still not-computerized Atlas of Owen, and both them constituted inspiration for the construction of a FORTRAN variable radius mapping code at INGV, with which it

  18. Ulnar Shortening Versus Distal Radius Corrective Osteotomy in the Management of Ulnar Impaction After Distal Radius Malunion.

    PubMed

    Aibinder, William R; Izadpanah, Ali; Elhassan, Bassem T

    2017-01-01

    Distal radius malunions lead to functional deficits. This study compares isolated ulnar shortening osteotomy (USO) to distal radius osteotomy (DRO) for the treatment of ulnar impaction syndrome following distal radius malunion. We retrospectively reviewed 11 patients with extra-articular distal radius malunions treated for ulnar impaction with isolated USO. This group was compared to a 1:1 age- and sex-matched cohort treated with isolated DRO for the same indication. Pain visual analog scale (VAS), wrist motion, grip strength, radiographic parameters, and perioperative complications were analyzed. Mean follow-up was 14.8 months. VAS scores improved. Wrist range of motion improved in both cohorts with the exception of radial deviation, pronation, and supination in the USO cohort, which decreased from a mean of 17°-16°, 67°-57°, and 54°-52°, respectively. There was no significant difference between groups in regard to change in pain or range of motion, with the exception of pronation and ulnar deviation. The mean tourniquet time was shorter in the USO group. The final ulnar variance was 1.8 mm negative in the USO group and 1.1 mm positive in the DRO group. There was 1 reoperation following USO for painful nonunion, while there were 2 reoperations following DRO for persistent ulnar impaction. An improvement in range of motion, grip strength, and VAS with restoration of the radioulnar length relationship was observed in both cohorts. USO is a simpler procedure with a shorter tourniquet time that can be an attractive alternative to DRO for ulnar impaction syndrome after distal radius malunions.

  19. Link between diurnal stem radius changes and tree water relations.

    PubMed

    Zweifel, R; Item, H; Häsler, R

    2001-08-01

    Internal water reserves are depleted and replenished daily, not only in succulent plants, but also in trees. The significance of these changes in tissue water storage for tree water relations was investigated by monitoring diurnal fluctuations in stem radius. In 6-year-old potted Norway spruce (Picea abies (L.) Karst.) trees, whole-tree transpiration rate (T), sap flow at the stem base and fluctuations in stem radius were measured at 10-min intervals over eight successive weeks. The dynamics of diurnal water storage in relation to the daily course of water movement was simulated and the contribution of stored water to T quantified. The finding that, in P. abies, the course of bark water content is linearly coupled to stem radius fluctuations provided the basis for linking stem radius changes to a functional flow and storage model for tree water relations. This model, which consists of physical functions only and is driven by a single input variable (T), accurately simulates the diurnal course of changes in stem radius and water storage of the tree crown and stem. It was concluded that fluctuations were mainly determined by the course of transpiration. The availability of soil water and the degree to which storage tissues were saturated were also factors affecting the diurnal course of stem radius changes. Internally stored water contributed to daily transpiration even in well-watered trees, indicating that stored water plays an important role not only during periods of drought, but whenever water transport occurs within the tree. Needle and bark water reserves were most heavily depleted during transpiration. Together they supplied approximately 10% of daily T on sunny days, and up to 65% on cloudy days. On a daily basis, the crown (mainly needles) contributed approximately eight times more water to T than the stem (mainly bark). The depletion of the two storage pools and the water movements observed in the trees always occurred in the same sequence. In the morning

  20. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic contact lens radius measuring device... lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device is an AC-powered device that is a microscope and dial gauge intended to measure the radius of a...

  1. Effect of ionic radii on the Curie temperature in Ba1-x-ySrxCayTiO3 compounds

    PubMed Central

    Berenov, A.; Le Goupil, F.; Alford, N.

    2016-01-01

    A series of Ba1-x-ySrxCayTiO3 compounds were prepared with varying average ionic radii and cation disorder on A-site. All samples showed typical ferroelectric behavior. A simple empirical equation correlated Curie temperature, TC, with the values of ionic radii of A-site cations. This correlation was related to the distortion of TiO6 octahedra observed during neutron diffraction studies. The equation was used for the selection of compounds with predetermined values of TC. The effects of A-site ionic radii on the temperatures of phase transitions in Ba1-x-ySrxCayTiO3 were discussed. PMID:27324841

  2. Flute waves at the ion Larmor radius scales

    SciTech Connect

    Onishchenko, O. G.

    2010-12-14

    The theory of the magnetic Rayleigh-Taylor instability (RTI) is discussed. Modified linear kinetic theory allows us to investigate RTI and flute waves with arbitrary perpendicular spatial scales compared to the ion Larmor radius. It is shown that in the linear limit a Fourier transform of these equations yields the dispersion relation which in the so-called Pade approximation corresponds to results of the kinetic theory. This analysis represents an extension of the previous study of the magnetic RTI obtained in the large wave scale approximation. It is shown that incorporation of the effects associated with wave scales of the order of the ion Larmor radius leads to a broader wave number range of the magnetic RTI.

  3. Core Deuterium Fusion and Radius Inflation in Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Jaikumar, Prashanth; Rachid Ouyed

    2016-06-01

    Several laboratory-based studies have shown that the Deuterium fusion cross-section is enhanced in a solid deuterated target as compared to a gas target, attributable to enhanced mobility of deuterons in a metal lattice. As an application, we propose that, for core temperatures and compositions characterizing hot Jupiters, screened Deuterium fusion can occur deep in the interior, and show that the amount of radius inflation from this effect can be important if there is sufficient rock-ice in the core. The mechanism of screened Deuterium fusion, operating in the above temperature range, is generally consistent with the trend in radius anomaly with planetary equilibrium temperature. We also explore the trend with planetary mass using a simple analytic model.

  4. Equatorial radius of the earth: A dynamical determination

    NASA Technical Reports Server (NTRS)

    Khan, M. A.

    1972-01-01

    An interesting variation on the familiar method of determining the earth's equatorial radius a sub e, from a knowledge of the earth's equatorial gravity is suggested. The value of equatorial radius thus found is 6378,142 + or - 5 meters. The associated parameters are GM = 3,986008 + or - 4 X 1014 cu cm/sec/sec which includes the relative mass of atmosphere approximately 0.000001 x GM, the equatorial gravity gamma sub e = 978,030.9 milligals (constrained in this solution by the Potsdam Correction of 13.67 milligals as the Potsdam Correction is more directly, or less indirectly, measurable than the equatorial gravity) and an ellipsoidal flattening of f = 1/298.255.

  5. Predicting jet radius in electrospinning by superpositioning exponential functions

    NASA Astrophysics Data System (ADS)

    Widartiningsih, P. M.; Iskandar, F.; Munir, M. M.; Viridi, S.

    2016-08-01

    This paper presents an analytical study of the correlation between viscosity and fiber diameter in electrospinning. Control over fiber diameter in electrospinning process was important since it will determine the performance of resulting nanofiber. Theoretically, fiber diameter was determined by surface tension, solution concentration, flow rate, and electric current. But experimentally it had been proven that significantly viscosity had an influence to fiber diameter. Jet radius equation in electrospinning process was divided into three areas: near the nozzle, far from the nozzle, and at jet terminal. There was no correlation between these equations. Superposition of exponential series model provides the equations combined into one, thus the entire of working parameters on electrospinning take a contribution to fiber diameter. This method yields the value of solution viscosity has a linear relation to jet radius. However, this method works only for low viscosity.

  6. [Distal radius fractures: new concepts as basis for surgical treatment].

    PubMed

    Rikli, D A; Babst, R; Jupiter, J B

    2007-02-01

    New advances in the biomechanics and pathomechanics of distal radius fractures as well as new generations of plates and improved surgical approaches now make possible the stable management and early functional rehabilitation not only of simple but also of complicated distal radius fractures according to the principles for articular and juxta-articular fractures. Especially for complex articular fractures, the fracture patterns are so heterogeneous that an individual surgical treatment strategy must be developed for each case. The preoperative clarification of articular fractures with computed tomography is particularly useful for planning surgery. Mental exposition with the three-column model and pathomechanics is an important prerequisite for understanding this type of injury and the appropriate choice of operative technique. A decisive factor for success is the subtle surgical procedure in approaching and handling the fine plates.

  7. Error analysis for a laser differential confocal radius measurement system.

    PubMed

    Wang, Xu; Qiu, Lirong; Zhao, Weiqian; Xiao, Yang; Wang, Zhongyu

    2015-02-10

    In order to further improve the measurement accuracy of the laser differential confocal radius measurement system (DCRMS) developed previously, a DCRMS error compensation model is established for the error sources, including laser source offset, test sphere position adjustment offset, test sphere figure, and motion error, based on analyzing the influences of these errors on the measurement accuracy of radius of curvature. Theoretical analyses and experiments indicate that the expanded uncertainty of the DCRMS is reduced to U=0.13  μm+0.9  ppm·R (k=2) through the error compensation model. The error analysis and compensation model established in this study can provide the theoretical foundation for improving the measurement accuracy of the DCRMS.

  8. Mass action in ionic solutions

    NASA Astrophysics Data System (ADS)

    Eisenberg, Bob

    2011-07-01

    The law of mass action describes reactants as simple ideal fluids of concentrations of uncharged noninteracting particles. Ionic solutions contain interacting charged particles and are not ideal. Interactions of reactants can then be mistaken for complexities in chemical reactions or enzymatic catalysts. The variational theory of complex fluids describes flowing mixtures like biological solutions. When a component is added, the theory derives-by mathematics alone-a new set of differential equations that automatically captures all interactions. A variational theory of ionic solutions (as complex fluids) provides computable description of ions in solutions and proteins. Numerical inefficiencies have delayed experimental verification.

  9. Lithium ion conducting ionic electrolytes

    DOEpatents

    Angell, C.A.; Xu, K.; Liu, C.

    1996-01-16

    A liquid, predominantly lithium-conducting, ionic electrolyte is described which has exceptionally high conductivity at temperatures of 100 C or lower, including room temperature. It comprises molten lithium salts or salt mixtures in which a small amount of an anionic polymer lithium salt is dissolved to stabilize the liquid against recrystallization. Further, a liquid ionic electrolyte which has been rubberized by addition of an extra proportion of anionic polymer, and which has good chemical and electrochemical stability, is described. This presents an attractive alternative to conventional salt-in-polymer electrolytes which are not cationic conductors. 4 figs.

  10. Lithium ion conducting ionic electrolytes

    DOEpatents

    Angell, C. Austen; Xu, Kang; Liu, Changle

    1996-01-01

    A liquid, predominantly lithium-conducting, ionic electrolyte is described which has exceptionally high conductivity at temperatures of 100.degree. C. or lower, including room temperature. It comprises molten lithium salts or salt mixtures in which a small amount of an anionic polymer lithium salt is dissolved to stabilize the liquid against recrystallization. Further, a liquid ionic electrolyte which has been rubberized by addition of an extra proportion of anionic polymer, and which has good chemical and electrochemical stability, is described. This presents an attractive alternative to conventional salt-in-polymer electrolytes which are not cationic conductors.

  11. Medical management of fragility fractures of the distal radius.

    PubMed

    Morgan, Emily N; Crawford, David A; Scully, William F; Noce, Nicholas J

    2014-12-01

    Fragility fractures of the distal radius represent an opportunity to diagnose and treat osteoporosis before further fractures occur. The goal of this study was to determine the prevalence of prescriptions for calcium/vitamin D supplementation and the prevalence of dual-energy x-ray absorptiometry (DEXA) scans in patients who sustained fragility fractures of the distal radius. A further goal was to determine the prevalence of patients who received prescriptions for the treatment of osteoporosis after DEXA scans. The authors performed a retrospective review of all patients 50 years and older who sustained a fragility fracture of the distal radius and were treated by the orthopedic surgery service at the authors' institution from 2004 to 2010. After a fragility fracture of the distal radius, fewer than 25% of previously unidentified at-risk patients received a prescription for vitamin supplementation and underwent a DEXA scan. Women were 7 times more likely than men to receive calcium/vitamin D supplementation, 14 times more likely to undergo a DEXA scan for the evaluation of osteoporosis, and 25 times more likely to receive a prescription for bisphosphonates. Patients who underwent a DEXA scan were 9 times more likely to receive pharmacologic treatment than those who did not undergo this scan. More than half of patients did not receive a prescription for calcium/vitamin D supplementation and did not undergo DEXA scanning as recommended by current National Osteoporosis Foundation guidelines. Most patients who received prescriptions or underwent DEXA scans did so before rather than after fracture, indicating poor compliance with National Osteoporosis Foundation guidelines. Copyright 2014, SLACK Incorporated.

  12. Radius fracture from an electrical injury involving an electric guitar.

    PubMed

    Pappano, Dante

    2010-03-01

    Electrical injury ranges widely from simple shock and mild burns to more extensive superficial injury, internal injury, and mortality. Bony fracture from electrically-induced tetanic muscle contraction is a rare but recognized injury. We report the case of a 14-year-old boy who suffered a minor burn and radius fracture related to an electrical injury involving his electric guitar. An interesting pattern is emerging from available case reports of similar injuries.

  13. Surface tension of ionic liquids and ionic liquid solutions.

    PubMed

    Tariq, Mohammad; Freire, Mara G; Saramago, Benilde; Coutinho, João A P; Lopes, José N Canongia; Rebelo, Luís Paulo N

    2012-01-21

    Some of the most active scientific research fronts of the past decade are centered on ionic liquids. These fluids present characteristic surface behavior and distinctive trends of their surface tension versus temperature. One way to explore and understand their unique nature is to study their surface properties. This critical review analyses most of the surface tension data reported between 2001 and 2010 (187 references).

  14. Scaling Relations of Mass, Velocity, and Radius for Disk Galaxies

    NASA Astrophysics Data System (ADS)

    Schulz, Earl

    2017-02-01

    I demonstrate four tight correlations of total baryonic mass, velocity, and radius for a set of nearby disk galaxies: the mass–velocity relation {M}{{t}}\\propto {V}4; the mass–radius relation {M}{{t}}\\propto {R}2; the radius–velocity relation R\\propto {V}2; and the mass–radius–velocity relation {M}{{t}}\\propto {{RV}}2. The mass–velocity relation is the familiar Baryonic Tully–Fisher relation, and versions of the other three relations, using magnitude rather than baryonic mass, are also well known. These four observed correlations follow from a pair of more fundamental relations. First, the centripetal acceleration at the edge of the stellar disk is proportional to the acceleration predicted by Newtonian physics, and second, this acceleration is a constant that is related to Milgrom’s constant. The two primary relations can be manipulated algebraically to generate the four observed correlations and allow little room for dark matter inside the radius of the stellar disk. The primary relations do not explain the velocity of the outer gaseous disks of spiral galaxies, which do not trace the Newtonian gravitational field of the observed matter.

  15. Is the proton radius puzzle evidence of extra dimensions?

    NASA Astrophysics Data System (ADS)

    Dahia, F.; Lemos, A. S.

    2016-08-01

    The proton charge radius inferred from muonic hydrogen spectroscopy is not compatible with the previous value given by CODATA-2010, which, on its turn, essentially relies on measurements of the electron-proton interaction. The proton's new size was extracted from the 2S-2P Lamb shift in the muonic hydrogen, which showed an energy excess of 0.3 meV in comparison to the theoretical prediction, evaluated with the CODATA radius. Higher-dimensional gravity is a candidate to explain this discrepancy, since the muon-proton gravitational interaction is stronger than the electron-proton interaction and, in the context of braneworld models, the gravitational potential can be hugely amplified in short distances when compared to the Newtonian potential. Motivated by these ideas, we study a muonic hydrogen confined in a thick brane. We show that the muon-proton gravitational interaction modified by extra dimensions can provide the additional separation of 0.3 meV between the 2S and 2P states. In this scenario, the gravitational energy depends on the higher-dimensional Planck mass and indirectly on the brane thickness. Studying the behavior of the gravitational energy with respect to the brane thickness in a realistic range, we find constraints for the fundamental Planck mass that solve the proton radius puzzle and are consistent with previous experimental bounds.

  16. Stokes radius determination of radioiodinated polypeptide hormones by gel filtration

    SciTech Connect

    Ribela, M.T.; Bartolini, P.

    1988-11-01

    A simple technique for determination of the molecular (Stokes) radius of radioiodinated proteins was developed using the same column and chromatographic conditions employed in routine radioimmunoassay tracer purification. The calibration curve for five radioiodinated standard proteins presented a highly significant correlation (r = -0.996; P less than 0.001) and allowed precise molecular radius determination for labeled human growth hormone (hGH), luteotropin (hLH), follicle-stimulating hormone (hFSH), thyrotropin (hTSH), prolactin (hPRL), and corticotropin (hACTH), enabling detection of differences of the order of +/- 3%. The validity of the method was verified by determining the molecular radius of hGH in both ''cold'' (unlabeled standards and unknowns) and ''hot'' (radioiodinated standards and unknowns) systems. The technique can be applied in a very simple manner, requiring just one simple additional calibration run before Sephadex G-100 tracer purification. Furthermore, it can be applied to any protein, even when only extremely limited amounts are available. Since the standards and unknowns are labeled and chromatographed under identical conditions, potential common alterations of the molecule due to oxidation, iodine incorporation, tracer-carrier interactions, etc., are automatically corrected for.

  17. Conversion of radius of curvature to power (and vice versa)

    NASA Astrophysics Data System (ADS)

    Wickenhagen, Sven; Endo, Kazumasa; Fuchs, Ulrike; Youngworth, Richard N.; Kiontke, Sven R.

    2015-09-01

    Manufacturing optical components relies on good measurements and specifications. One of the most precise measurements routinely required is the form accuracy. In practice, form deviation from the ideal surface is effectively low frequency errors, where the form error most often accounts for no more than a few undulations across a surface. These types of errors are measured in a variety of ways including interferometry and tactile methods like profilometry, with the latter often being employed for aspheres and general surface shapes such as freeforms. This paper provides a basis for a correct description of power and radius of curvature tolerances, including best practices and calculating the power value with respect to the radius deviation (and vice versa) of the surface form. A consistent definition of the sagitta is presented, along with different cases in manufacturing that are of interest to fabricators and designers. The results make clear how the definitions and results should be documented, for all measurement setups. Relationships between power and radius of curvature are shown that allow specifying the preferred metric based on final accuracy and measurement method. Results shown include all necessary equations for conversion to give optical designers and manufacturers a consistent and robust basis for decision-making. The paper also gives guidance on preferred methods for different scenarios for surface types, accuracy required, and metrology methods employed.

  18. Optimizing interconnections to maximize the spectral radius of interdependent networks

    NASA Astrophysics Data System (ADS)

    Chen, Huashan; Zhao, Xiuyan; Liu, Feng; Xu, Shouhuai; Lu, Wenlian

    2017-03-01

    The spectral radius (i.e., the largest eigenvalue) of the adjacency matrices of complex networks is an important quantity that governs the behavior of many dynamic processes on the networks, such as synchronization and epidemics. Studies in the literature focused on bounding this quantity. In this paper, we investigate how to maximize the spectral radius of interdependent networks by optimally linking k internetwork connections (or interconnections for short). We derive formulas for the estimation of the spectral radius of interdependent networks and employ these results to develop a suite of algorithms that are applicable to different parameter regimes. In particular, a simple algorithm is to link the k nodes with the largest k eigenvector centralities in one network to the node in the other network with a certain property related to both networks. We demonstrate the applicability of our algorithms via extensive simulations. We discuss the physical implications of the results, including how the optimal interconnections can more effectively decrease the threshold of epidemic spreading in the susceptible-infected-susceptible model and the threshold of synchronization of coupled Kuramoto oscillators.

  19. Simulation for Proton Charge Radius (PRad) Experiment at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Ye, Li; PRad Collaboration Collaboration

    2016-09-01

    The ``Proton Charge Radius Puzzle'' refers to 7 σ discrepancy between the proton charge radius extracted from muonic hydrogen Lamb shift measurements and that from the atomic hydrogen Lamb shift and e-p elastic scattering measurements. In order to get a better understanding of this puzzle, the PRad experiment (E12-11-106) was proposed and recently performed with 1.1 and 2.2 GeV unpolarized electron beam in Hall B at Jefferson Lab. The experiment aims to extract the electric form factor and the charge radius of proton by simultaneously measuring the e - p elastic scattering cross section and the Møller cross section at very low Q2(2 × 10-4 10-1(GeV / c) 2) region, with sub-percent precision. A windowless hydrogen gas flow target was used to better control the background. A high-efficiency and high-resolution calorimeter (HyCal) and a pair of Gas Electron Multiplier (GEM) chambers were used in the experiment. This talk will focus on comparing the detailed simulation of PRad experiment and its background with preliminary spectra from the data. This work is supported in part by NSF MRI Award PHY-1229153, the U.S. Department of Energy under Contacts No. DE-FG02-07ER41528, Thomas Jefferson National Laboratory, Mississippi State University and PRad collaboration.

  20. Complications of pediatric distal radius and forearm fractures.

    PubMed

    Chia, Benjamin; Kozin, Scott H; Herman, Martin J; Safier, Shannon; Abzug, Joshua M

    2015-01-01

    Distal radius and forearm fractures represent a large percentage of pediatric fractures. The most common mechanism of injury is a fall onto an outstretched arm, which can lead to substantial rotational displacement. If this rotational displacement is not adequately addressed, there will be resultant loss of forearm motion and subsequent limitations in performing the activities of daily living. Good initial reductions and proper casting techniques are necessary when treating distal radius and forearm fractures nonsurgically; however, maintaining an acceptable reduction is not always possible. Atraumatic reduction of a displaced physeal fracture should occur within 7 days of the injury. If an impending malunion presents at 2 weeks or later after injury, observation is warranted because of concerns about physeal arrest with repeated attempts at manipulation, and it should be followed by a later assessment of functional limitations. Pediatric patients and their parents have higher expectations for recovery, which has contributed to an increase in the surgical management of pediatric distal radius and forearm fractures. In addition, surgical interventions, such as intramedullary nailing, have their own associated complications.

  1. Neutron charge radius and the neutron electric form factor

    SciTech Connect

    Gentile, T. R.; Crawford, C. B.

    2011-05-15

    For nearly forty years, the Galster parametrization has been employed to fit existing data for the neutron electric form factor, G{sub E}{sup n}, vs the square of the four-momentum transfer, Q{sup 2}. Typically this parametrization is constrained to be consistent with experimental data for the neutron charge radius. However, we find that the Galster form does not have sufficient freedom to accommodate reasonable values of the radius without constraining or compromising the fit. In addition, the G{sub E}{sup n} data are now at sufficient precision to motivate a two-parameter fit (or three parameters if we include thermal neutron data). Here we present a modified form of a two-dipole parametrization that allows this freedom and fits both G{sub E}{sup n} (including recent data at both low and high four-momentum transfer) and the charge radius well with simple, well-defined parameters. Analysis reveals that the Galster form is essentially a two-parameter approximation to the two-dipole form but becomes degenerate if we try to extend it naturally to three parameters.

  2. Nanoparticle enhanced ionic liquid heat transfer fluids

    DOEpatents

    Fox, Elise B.; Visser, Ann E.; Bridges, Nicholas J.; Gray, Joshua R.; Garcia-Diaz, Brenda L.

    2014-08-12

    A heat transfer fluid created from nanoparticles that are dispersed into an ionic liquid is provided. Small volumes of nanoparticles are created from e.g., metals or metal oxides and/or alloys of such materials are dispersed into ionic liquids to create a heat transfer fluid. The nanoparticles can be dispersed directly into the ionic liquid during nanoparticle formation or the nanoparticles can be formed and then, in a subsequent step, dispersed into the ionic liquid using e.g., agitation.

  3. "Practical" Electrospinning of Biopolymers in Ionic Liquids.

    PubMed

    Shamshina, Julia L; Zavgorodnya, Oleksandra; Bonner, Jonathan R; Gurau, Gabriela; Di Nardo, Thomas; Rogers, Robin D

    2017-01-10

    To address the need to scale up technologies for electrospinning of biopolymers from ionic liquids to practical volumes, a setup for the multi-needle electrospinning of chitin using the ionic liquid 1-ethyl-3-methylimidazolium acetate, [C2 mim]-[OAc], was designed, built, and demonstrated. Materials with controllable and high surface area were prepared at the nanoscale using ionic-liquid solutions of high-molecular-weight chitin extracted with the same ionic liquid directly from shrimp shells.

  4. High-flux ionic diodes, ionic transistors and ionic amplifiers based on external ion concentration polarization by an ion exchange membrane: a new scalable ionic circuit platform.

    PubMed

    Sun, Gongchen; Senapati, Satyajyoti; Chang, Hsueh-Chia

    2016-04-07

    A microfluidic ion exchange membrane hybrid chip is fabricated using polymer-based, lithography-free methods to achieve ionic diode, transistor and amplifier functionalities with the same four-terminal design. The high ionic flux (>100 μA) feature of the chip can enable a scalable integrated ionic circuit platform for micro-total-analytical systems.

  5. High-flux ionic diodes, ionic transistors and ionic amplifiers based on external ion concentration polarization by an ion exchange membrane: a new scalable ionic circuit platform†

    PubMed Central

    Sun, Gongchen; Senapati, Satyajyoti

    2016-01-01

    A microfluidic-ion exchange membrane hybrid chip is fabricated by polymer-based, lithography-free methods to achieve ionic diode, transistor and amplifier functionalities with the same four-terminal design. The high ionic flux (> 100 μA) feature of the chip can enable a scalable integrated ionic circuit platform for micro-total-analytical systems. PMID:26960551

  6. Ionic Strength Sensing in Living Cells.

    PubMed

    Liu, Boqun; Poolman, Bert; Boersma, Arnold J

    2017-09-06

    Knowledge of the ionic strength in cells is required to understand the in vivo biochemistry of the charged biomacromolecules. Here, we present the first sensors to determine the ionic strength in living cells, by designing protein probes based on Förster resonance energy transfer (FRET). These probes allow observation of spatiotemporal changes in the ionic strength on the single-cell level.

  7. Predicting initial treatment failure of fiberglass casts in pediatric distal radius fractures: utility of the second metacarpal-radius angle.

    PubMed

    Edmonds, Eric W; Capelo, Roderick M; Stearns, Philip; Bastrom, Tracey P; Wallace, C Douglas; Newton, Peter O

    2009-10-01

    Recent literature comparing the effectiveness of above-elbow and below-elbow plaster casts appears to suggest that either cast type offers adequate immobilization for distal radius and ulna fractures. The idea that an appropriate mold placed on the cast is the most significant determinant of successful immobilization and, thereby, patient outcome has also been elucidated. The purpose of this study was to compare the effectiveness of above-elbow versus below-elbow fiberglass casts in maintaining distal radius/ulna fracture reduction and to identify factors associated with treatment failures. We reviewed the radiographs and clinical data of 253 children with distal third forearm fractures requiring reduction under conscious sedation or a hematoma block. Outcome measures included rates of re-manipulation, loss of reduction, and cast complications. One hundred and nineteen children were treated with below-elbow fiberglass casts and 134 were treated with above-elbow fiberglass casts based on a clinical pathway created before the study period. There were no differences between the two groups in age, weight, fracture pattern, percentage of both-bone fractures, and initial fracture angulation. Of the 253 fractures in the study, 38 (15%) were considered to have less than ideal outcomes. There were no differences between the 'ideal' and 'non-ideal' groups in age, fracture pattern, presence of ulna fracture, cast index, or cast type. All immediate post-reduction measures (anterior-posterior [AP] and lateral displacement/angulation) were significantly correlated with treatment outcome, except angulation on AP films. The magnitude of reduction as measured by a newly described variable, the angle between the second metacarpal and long axis of the radius in the AP projection, was significantly correlated with treatment failure (r = -0.139, P = 0.027). Binary logistic regression was performed and demonstrated that the success of the reduction, as determined by the AP radiograph

  8. Fluctuating hydrodynamics for ionic liquids

    NASA Astrophysics Data System (ADS)

    Lazaridis, Konstantinos; Wickham, Logan; Voulgarakis, Nikolaos

    2017-04-01

    We present a mean-field fluctuating hydrodynamics (FHD) method for studying the structural and transport properties of ionic liquids in bulk and near electrified surfaces. The free energy of the system consists of two competing terms: (1) a Landau-Lifshitz functional that models the spontaneous separation of the ionic groups, and (2) the standard mean-field electrostatic interaction between the ions in the liquid. The numerical approach used to solve the resulting FHD-Poisson equations is very efficient and models thermal fluctuations with remarkable accuracy. Such density fluctuations are sufficiently strong to excite the experimentally observed spontaneous formation of liquid nano-domains. Statistical analysis of our simulations provides quantitative information about the properties of ionic liquids, such as the mixing quality, stability, and the size of the nano-domains. Our model, thus, can be adequately parameterized by directly comparing our prediction with experimental measurements and all-atom simulations. Conclusively, this work can serve as a practical mathematical tool for testing various theories and designing more efficient mixtures of ionic liquids.

  9. Electrode screening by ionic liquids.

    PubMed

    Lynden-Bell, R M; Frolov, A I; Fedorov, M V

    2012-02-28

    In this work we are concerned with the short-range screening provided by the ionic liquid dimethylimidazolium chloride near a charged wall. We study the free energy profiles (or potentials of mean force) for charged and neutral solutes as a function of distance from a charged wall. Four different wall charge densities are used in addition to a wall with zero charge. The highest magnitude of the charge densities is ±1 e nm(-2) which is close to the maximum limit of charge densities accessible in experiments, while the intermediate charges ±0.5 e nm(-2) are in the range of densities typically used in most of the experimental studies. Positively and negatively charged solutes of approximately the size of a BF ion and a Cl(-) ion are used as probes. We find that the ionic liquid provides excellent electrostatic screening at a distance of 1-2 nm. The free energy profiles show minima which are due to layering in the ionic liquid near the electrodes. This indicates that the solute ions tend to displace ionic liquid ions in the layers when approaching the electrode. The important role of non-electrostatic forces is demonstrated by the oscillations in the free energy profiles of uncharged solutes as a function of distance from the wall.

  10. Design of Energetic Ionic Liquids

    DTIC Science & Technology

    2010-04-15

    dynamics and structure in imidazolium -based ionic liquids/water mixtures. [15] The results of density and molar volume profile from MD simulations are...depending upon their respective attachment to boron or oxygen). The large blue sphere represents imidazolium ring. (b) The average sizes of cation

  11. Plan a Site Visit with Your Legislator

    ERIC Educational Resources Information Center

    Ochs, Mike

    2005-01-01

    When members of Congress head home for a recess, participants in the grassroots network have an opportunity to use one of their effective education tools: the site visit. A site visit occurs when a legislator actually visits one's business, school, or organization to see one's work firsthand. A local site visit is effective because grassroots…

  12. Dialogue as a Site of Transformative Possibility

    ERIC Educational Resources Information Center

    Sinha, Shilpi

    2010-01-01

    This article examines how affect allows us to view the relational form of dialogue, as built upon the work of Derrida and Levinas, to be a site of transformative possibility for students as they encounter and address issues of social justice and difference in the classroom. The understanding of affect that attends this form of dialogue demands…

  13. Maximum wind radius estimated by the 50 kt radius: improvement of storm surge forecasting over the Western North Pacific

    NASA Astrophysics Data System (ADS)

    Takagi, H.; Wu, W.

    2015-10-01

    Even though the maximum wind radius (Rmax) is an important parameter in determining the intensity and size of tropical cyclones, it has been overlooked in previous storm surge studies. This research reviewed the existing estimation methods of Rmax based on the central pressure or maximum wind speed. These over or underestimated Rmax because of the substantial variety of the data, though an average radius could be moderately estimated. Alternatively, we proposed an Rmax estimation method based on the radius of the 50 knot wind (R50). The data obtained during the passage of strong typhoons by a meteorological station network in the Japanese archipelago enabled us to derive the following formula, Rmax = 0.23R50. Although this new method substantially improved the estimation of Rmax compared to the existing models, an estimation error was unavoidable because of fundamental uncertainties regarding the typhoon's structure or insufficient number of available typhoon data. In fact, a numerical simulation from 2013 Typhoon Haiyan demonstrated a substantial difference in the storm surge height for different Rmax. Therefore, the variability of Rmax should be taken into account in storm surge simulations, independently of the model used, to minimize the risk of over or underestimation of storm surges. The proposed method is expected to increase the reliability of storm surge prediction and contribute to disaster risk management, particularly in the Western North Pacific, including countries such as Japan, China, Taiwan, Philippines, and Vietnam.

  14. Application of ionic liquids in hydrometallurgy.

    PubMed

    Park, Jesik; Jung, Yeojin; Kusumah, Priyandi; Lee, Jinyoung; Kwon, Kyungjung; Lee, Churl Kyoung

    2014-08-29

    Ionic liquids, low temperature molten salts, have various advantages manifesting themselves as durable and environmentally friendly solvents. Their application is expanding into various fields including hydrometallurgy due to their unique properties such as non-volatility, inflammability, low toxicity, good ionic conductivity, and wide electrochemical potential window. This paper reviews previous literatures and our recent results adopting ionic liquids in extraction, synthesis and processing of metals with an emphasis on the electrolysis of active/light, rare earth, and platinum group metals. Because the research and development of ionic liquids in this area are still emerging, various, more fundamental approaches are expected to popularize ionic liquids in the metal manufacturing industry.

  15. Application of Ionic Liquids in Hydrometallurgy

    PubMed Central

    Park, Jesik; Jung, Yeojin; Kusumah, Priyandi; Lee, Jinyoung; Kwon, Kyungjung; Lee, Churl Kyoung

    2014-01-01

    Ionic liquids, low temperature molten salts, have various advantages manifesting themselves as durable and environmentally friendly solvents. Their application is expanding into various fields including hydrometallurgy due to their unique properties such as non-volatility, inflammability, low toxicity, good ionic conductivity, and wide electrochemical potential window. This paper reviews previous literatures and our recent results adopting ionic liquids in extraction, synthesis and processing of metals with an emphasis on the electrolysis of active/light, rare earth, and platinum group metals. Because the research and development of ionic liquids in this area are still emerging, various, more fundamental approaches are expected to popularize ionic liquids in the metal manufacturing industry. PMID:25177864

  16. Ionic resistance measurements of battery separators

    SciTech Connect

    Danko, T.; Sybeldon, A.

    1997-12-01

    The performance of a battery is affected by the ionic resistance of the separator used to separate the anode from the cathode. If the ionic resistance is too high, the power output from the battery is diminished because the flow of ions is hindered. This paper examines issues that affect the ionic resistance of regenerated cellulose membranes. In particular, changes in the pore size, or molecular weight cut off, of the membranes are correlated with ionic resistance to show that changes in molecular weight cut off do effect ionic resistance.

  17. Observation of ionic Coulomb blockade in nanopores

    NASA Astrophysics Data System (ADS)

    Feng, Jiandong; Liu, Ke; Graf, Michael; Dumcenco, Dumitru; Kis, Andras; di Ventra, Massimiliano; Radenovic, Aleksandra

    2016-08-01

    Emergent behaviour from electron-transport properties is routinely observed in systems with dimensions approaching the nanoscale. However, analogous mesoscopic behaviour resulting from ionic transport has so far not been observed, most probably because of bottlenecks in the controlled fabrication of subnanometre nanopores for use in nanofluidics. Here, we report measurements of ionic transport through a single subnanometre pore junction, and the observation of ionic Coulomb blockade: the ionic counterpart of the electronic Coulomb blockade observed for quantum dots. Our findings demonstrate that nanoscopic, atomically thin pores allow for the exploration of phenomena in ionic transport, and suggest that nanopores may also further our understanding of transport through biological ion channels.

  18. HABITABILITY OF EXOMOONS AT THE HILL OR TIDAL LOCKING RADIUS

    SciTech Connect

    Hinkel, Natalie R.; Kane, Stephen R.

    2013-09-01

    Moons orbiting extrasolar planets are the next class of object to be observed and characterized for possible habitability. Like the host-planets to their host-star, exomoons have a limiting radius at which they may be gravitationally bound, or the Hill radius. In addition, they also have a distance at which they will become tidally locked and therefore in synchronous rotation with the planet. We have examined the flux phase profile of a simulated, hypothetical moon orbiting at a distant radius around the confirmed exoplanets {mu} Ara b, HD 28185 b, BD +14 4559 b, and HD 73534 b. The irradiated flux on a moon at its furthest, stable distance from the planet achieves its largest flux gradient, which places a limit on the flux ranges expected for subsequent (observed) moons closer in orbit to the planet. We have also analyzed the effect of planetary eccentricity on the flux on the moon, examining planets that traverse the habitable zone either fully or partially during their orbit. Looking solely at the stellar contributions, we find that moons around planets that are totally within the habitable zone experience thermal equilibrium temperatures above the runaway greenhouse limit, requiring a small heat redistribution efficiency. In contrast, exomoons orbiting planets that only spend a fraction of their time within the habitable zone require a heat redistribution efficiency near 100% in order to achieve temperatures suitable for habitability. This means that a planet does not need to spend its entire orbit within the habitable zone in order for the exomoon to be habitable. Because the applied systems comprise giant planets around bright stars, we believe that the transit detection method is most likely to yield an exomoon discovery.

  19. Habitability of Exomoons at the Hill or Tidal Locking Radius

    NASA Astrophysics Data System (ADS)

    Hinkel, Natalie R.; Kane, Stephen R.

    2013-09-01

    Moons orbiting extrasolar planets are the next class of object to be observed and characterized for possible habitability. Like the host-planets to their host-star, exomoons have a limiting radius at which they may be gravitationally bound, or the Hill radius. In addition, they also have a distance at which they will become tidally locked and therefore in synchronous rotation with the planet. We have examined the flux phase profile of a simulated, hypothetical moon orbiting at a distant radius around the confirmed exoplanets μ Ara b, HD 28185 b, BD +14 4559 b, and HD 73534 b. The irradiated flux on a moon at its furthest, stable distance from the planet achieves its largest flux gradient, which places a limit on the flux ranges expected for subsequent (observed) moons closer in orbit to the planet. We have also analyzed the effect of planetary eccentricity on the flux on the moon, examining planets that traverse the habitable zone either fully or partially during their orbit. Looking solely at the stellar contributions, we find that moons around planets that are totally within the habitable zone experience thermal equilibrium temperatures above the runaway greenhouse limit, requiring a small heat redistribution efficiency. In contrast, exomoons orbiting planets that only spend a fraction of their time within the habitable zone require a heat redistribution efficiency near 100% in order to achieve temperatures suitable for habitability. This means that a planet does not need to spend its entire orbit within the habitable zone in order for the exomoon to be habitable. Because the applied systems comprise giant planets around bright stars, we believe that the transit detection method is most likely to yield an exomoon discovery.

  20. Radiographic Outcomes of Volar Locked Plating for Distal Radius Fractures

    PubMed Central

    Mignemi, Megan E.; Byram, Ian R.; Wolfe, Carmen C.; Fan, Kang-Hsien; Koehler, Elizabeth A.; Block, John J.; Jordanov, Martin I.; Watson, Jeffry T.; Weikert, Douglas R.; Lee, Donald H.

    2013-01-01

    Purpose To assess the ability of volar locked plating to achieve and maintain normal radiographic parameters for articular stepoff, volar tilt, radial inclination, ulnar variance, and radial height in distal radius fractures. Methods We performed a retrospective review of 185 distal radius fractures that underwent volar locked plating with a single plate design over a 5-year period. We reviewed radiographs and recorded measurements for volar tilt, radial inclination, ulnar variance, radial height, and articular stepoff. We used logistic regression to determine the association between return to radiographic standard norms and fracture type. Results At the first and final postoperative follow-up visits, we observed articular congruence less than 2 mm in 92% of fractures at both times. Normal volar tilt (11°) was restored in 46% at the first follow-up and 48% at the final one. Radial inclination (22°) was achieved in 44% at the first follow-up and 43% at the final one, and ulnar variance (01 ± 2 mm) was achieved in 53% at the first follow-up and 53% at the final one. In addition, radial height (14 ± 1mm) was restored in 14% at the first follow-up and 12% at the final one. More complex, intra-articular fractures (AO class B and C and Frykman types 3, 4, 7, and 8) were less likely to be restored to normal radiographic parameters. However, because of the small sample size for some fracture types, it was difficult to discover significant associations between fracture type and radiographic outcome. Conclusions Volar locked plating for distal radius fractures achieved articular stepoff less than 2 mm in most fractures but only restored and maintained normal radiographic measurements for volar tilt, radial inclination, and ulnar variance in 50% of fractures. The ability of volar locked plating to restore and maintain ulnar variance and volar tilt decreased with more complex intra-articular fracture types. PMID:23218558

  1. [Radius fractures in children--causes and mechanisms of injury].

    PubMed

    Antabak, Anko; Stanić, Lana; Matković, Nikša; Papeš, Dino; Romić, Ivan; Fuchs, Nino; Luetić, Tomislav

    2015-01-01

    Radius fractures are the most common fractures in childhood. The main mechanism of injury is fall onto an outstretched hand. This retrospective study analyzed the data on 201 children admitted for radius fractures at KBC-Zagreb in the period 2011-2013. The study included 85 girls (42.3%) and 116 boys (57.7%) . The average age of the children was 9.6 years. Radius was injured in the distal segment in 79.1% of children. The sites of injuries were: park, campi and beach (24.9% of all children), playground, skate park and swimming pool (23.9%), kindergarten or school (20.9%), at home and around the house (17.9%), in the street (11.4%) and in the store or at a hotel (0.9%). The boys were mostly injured at playgrounds, during skating and at swimming pools (37.1% of all boys), while girls were mostly injured in parks, camps and at beach (42.4% girls). Fall was the major cause of the injury (49.3%), and children usually fell during ice skating and skating (32.3% of all falls). In 20.4% the injury was caused by pushing and hitting. The smallest percentage (9.5%) of children were injured in traffic accidents while riding a bike (only one child was hit by a car). Sport related activities caused injuries in 53.7% of the cases. Sport activities are the most important cause of the radial fractures in the pediatric population and falls during sports are the main mechanism of injury. The peak incidence is at 12 years for boys and at 10 years for girls, so intervention and/or prevention should be aimed at the age groups. Preventive actions should be focused on injuries that tend to occur in parks, schools and during sport activities.

  2. Measurement of Capillary Radius and Contact Angle within Porous Media.

    PubMed

    Ravi, Saitej; Dharmarajan, Ramanathan; Moghaddam, Saeed

    2015-12-01

    The pore radius (i.e., capillary radius) and contact angle determine the capillary pressure generated in a porous medium. The most common method to determine these two parameters is through measurement of the capillary pressure generated by a reference liquid (i.e., a liquid with near-zero contact angle) and a test liquid. The rate of rise technique, commonly used to determine the capillary pressure, results in significant uncertainties. In this study, we utilize a recently developed technique for independently measuring the capillary pressure and permeability to determine the equivalent minimum capillary radii and contact angle of water within micropillar wick structures. In this method, the experimentally measured dryout threshold of a wick structure at different wicking lengths is fit to Darcy's law to extract the maximum capillary pressure generated by the test liquid. The equivalent minimum capillary radii of different wick geometries are determined by measuring the maximum capillary pressures generated using n-hexane as the working fluid. It is found that the equivalent minimum capillary radius is dependent on the diameter of pillars and the spacing between pillars. The equivalent capillary radii of micropillar wicks determined using the new method are found to be up to 7 times greater than the current geometry-based first-order estimates. The contact angle subtended by water at the walls of the micropillars is determined by measuring the capillary pressure generated by water within the arrays and the measured capillary radii for the different geometries. This mean contact angle of water is determined to be 54.7°.

  3. Fractal analysis of bone architecture at distal radius.

    PubMed

    Tomomitsu, Tatsushi; Mimura, Hiroaki; Murase, Kenya; Sone, Teruki; Fukunaga, Masao

    2005-12-20

    Bone strength depends on bone quality (architecture, turnover, damage accumulation, and mineralization) as well as bone mass. In this study, human bone architecture was analyzed using fractal image analysis, and the clinical relevance of this method was evaluated. The subjects were 12 healthy female controls and 16 female patients suspected of having osteoporosis (age range, 22-70 years; mean age, 49.1 years). High-resolution CT images of the distal radius were acquired and analyzed using a peripheral quantitative computed tomography (pQCT) system. On the same day, bone mineral densities of the lumbar spine (L-BMD), proximal femur (F-BMD), and distal radius (R-BMD) were measured by dual-energy X-ray absorptiometry (DXA). We examined the correlation between the fractal dimension and six bone mass indices. Subjects diagnosed with osteopenia or osteoporosis were divided into two groups (with and without vertebral fracture), and we compared measured values between these two groups. The fractal dimension correlated most closely with L-BMD (r=0.744). The coefficient of correlation between the fractal dimension and L-BMD was very similar to the coefficient of correlation between L-BMD and F-BMD (r=0.783) and the coefficient of correlation between L-BMD and R-BMD (r=0.742). The fractal dimension was the only measured value that differed significantly between both the osteopenic and the osteoporotic subjects with and without vertebral fracture. The present results suggest that the fractal dimension of the distal radius can be reliably used as a bone strength index that reflects bone architecture as well as bone mass.

  4. Neutron Star Mass-Radius Constraints Using Evolutionary Optimization

    NASA Astrophysics Data System (ADS)

    Stevens, A. L.; Fiege, J. D.; Leahy, D. A.; Morsink, S. M.

    2016-12-01

    The equation of state of cold supra-nuclear-density matter, such as in neutron stars, is an open question in astrophysics. A promising method for constraining the neutron star equation of state is modeling pulse profiles of thermonuclear X-ray burst oscillations from hot spots on accreting neutron stars. The pulse profiles, constructed using spherical and oblate neutron star models, are comparable to what would be observed by a next-generation X-ray timing instrument like ASTROSAT, NICER, or a mission similar to LOFT. In this paper, we showcase the use of an evolutionary optimization algorithm to fit pulse profiles to determine the best-fit masses and radii. By fitting synthetic data, we assess how well the optimization algorithm can recover the input parameters. Multiple Poisson realizations of the synthetic pulse profiles, constructed with 1.6 million counts and no background, were fitted with the Ferret algorithm to analyze both statistical and degeneracy-related uncertainty and to explore how the goodness of fit depends on the input parameters. For the regions of parameter space sampled by our tests, the best-determined parameter is the projected velocity of the spot along the observer’s line of sight, with an accuracy of ≤3% compared to the true value and with ≤5% statistical uncertainty. The next best determined are the mass and radius; for a neutron star with a spin frequency of 600 Hz, the best-fit mass and radius are accurate to ≤5%, with respective uncertainties of ≤7% and ≤10%. The accuracy and precision depend on the observer inclination and spot colatitude, with values of ˜1% achievable in mass and radius if both the inclination and colatitude are ≳60°.

  5. Nanoparticles in ionic liquids: interactions and organization.

    PubMed

    He, Zhiqi; Alexandridis, Paschalis

    2015-07-28

    Ionic liquids (ILs), defined as low-melting organic salts, are a novel class of compounds with unique properties and a combinatorially great chemical diversity. Ionic liquids are utilized as synthesis and dispersion media for nanoparticles as well as for surface functionalization. Ionic liquid and nanoparticle hybrid systems are governed by a combined effect of several intermolecular interactions between their constituents. For each interaction, including van der Waals, electrostatic, structural, solvophobic, steric, and hydrogen bonding, the characterization and quantitative calculation methods together with factors affecting these interactions are reviewed here. Various self-organized structures based on nanoparticles in ionic liquids are generated as a result of a balance of these intermolecular interactions. These structures, including colloidal glasses and gels, lyotropic liquid crystals, nanoparticle-stabilized ionic liquid-containing emulsions, ionic liquid surface-functionalized nanoparticles, and nanoscale ionic materials, possess properties of both ionic liquids and nanoparticles, which render them useful as novel materials especially in electrochemical and catalysis applications. This review of the interactions within nanoparticle dispersions in ionic liquids and of the structure of nanoparticle and ionic liquid hybrids provides guidance on the rational design of novel ionic liquid-based materials, enabling applications in broad areas.

  6. Augmentation of hemagglutination by low ionic conditions.

    PubMed

    Rosenfield, R E; Shaikh, S H; Innella, F; Kaczera, Z; Kochwa, S

    1979-01-01

    Short incubation at 37 C, 80 per cent reduction in ionic concentration and removal of liquid phases after each reaction step, provided the basis for the construction of four new serologic tests for alloantibodies to human erythrocytes. In the first, the incubation fluid was replaced with protamine sulfate to aggregate intensely the evaluated red blood cells. After dispersal by phosphate buffer, residual antibody mediated agglutination could be discerned. As a second method, this low ionic polycation (LIP) test was followed by a normal ionic IgG antiglobulin test (LIP-AGT). A third method employed low ionic washing of erythrocytes and low ionic antiglobulin serum (LIAGT). Finally, a modified LIP test was conducted entirely under low ionic conditions and followed by a low ionic antiglobulin test (modified LIP-AGT). LIP, LIP-AGT and LIAGT were successfully employed for all routine blood bank serology tests. Their sensitivity and impact on blood bank performance are described.

  7. Trajectory Calculator for Finite-Radius Cutter on a Lathe

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy; Strekalov, Dmitry; Yu, Nan

    2009-01-01

    A computer program calculates the two-dimensional trajectory (radial vs. axial position) of a finite-radius-of-curvature cutting tool on a lathe so as to cut a workpiece to a piecewise-continuous, analytically defined surface of revolution. (In the original intended application, the tool is a diamond cutter, and the workpiece is made of a crystalline material and is to be formed into an optical resonator disk.) The program also calculates an optimum cutting speed as F/L, where F is a material-dependent empirical factor and L is the effective instantaneous length of the cutting edge.

  8. Stabilisation of distal radius fractures: Lessons learned and future directions.

    PubMed

    Horst, Taylor A; Jupiter, Jesse B

    2016-02-01

    Our understanding of the diagnosis and management of distal radius fractures has been a long developed over centuries. There has been a shift in treatment of these very common injuries from closed reduction and casting to internal fixation. The answer to the best method of treatment has yet to be found. Today, we have a multitude of treatment options available with varying degrees of evidence to support their use. This review helps to illustrate the lessons we have learned and future directions for treatment.

  9. Method and apparatus for logging short radius horizontal drainholes

    SciTech Connect

    Taylor, D.E.

    1991-04-30

    This patent describes an apparatus for use in logging a short radius horizontal drainhole. It comprises: a tubing string having a low portion; the lower portion of the tubing string including sensor support means therein; the lower portion of the tubing string containing openings communicating with the interior thereof in the vicinity of the sensor support means to thereby exposed the interior to the pressure and temperature conditions of the horizontal drainhole; and the lower portion of the tubing string including an end portion extending transversely of the tubing sting.

  10. Experimental Method for Microbubbles Dynamics Monitoring and Radius Sizing

    NASA Astrophysics Data System (ADS)

    Fouan, Damien; Achaoui, Younes; Payan, Cedric; Mensah, Serge

    Rationale and aim: Within the context of divers' decompression illness prevention, ultrasonic detection and sizing of circulating microbubbles in blood is of great interest. In order to be representative of the divers gas tension level (supersaturation) and thus, to optimize decompression stages, the measurements (made in the right ventricle region) should be performed during a short period of time (ventricle filling <20 ms), efficient to detect a broad range of bubbles' radii population (radius from 20 to 200 _m) and harmless (Mechanical Index MI<0.3).

  11. Primary Combined Replacements for Treatment of Distal Radius Physeal Arrest

    PubMed Central

    Schmidt, Ingo

    2014-01-01

    This is a case report of a 59-year-old female patient with a posttraumatic growth arrest of the distal radius, leading to radioscaphoid osteoarthritis, carpal instability, and a symptomatic ulnocarpal impaction syndrome that was successfully treated with combined total wrist arthroplasty and ulnar head implant. One year postoperatively, there was no change in position without any signs of loosening of both implants. Both subjectively and functionally, all clinical parameters—Disabilities of the Arm, Shoulder, and Hand (DASH), visual analog scale (VAS), grip strength—had improved. Level of Evidence: IV PMID:25097815

  12. [Skeletal tuberculosis of the distal radius during pregnancy].

    PubMed

    Sander, A L; Laurer, H; Sommer, K; Jakob, H; Lehnert, M; Marzi, I

    2012-02-01

    We present a case of a pregnant woman (32nd gestational week) that suffered from a chronic non-healing wound at the distal radius. Skeletal tuberculosis was finally diagnosed and treated successfully with staged surgical therapy combined with appropriate medication. One year after surgical treatment, the outcome of the mother was excellent and the baby did not suffer from any disease related to operative procedures or pharmacotherapy. Operative treatment of skeletal tuberculosis (especially osteoarticular and vertebral tuberculosis) in combination with tuberculostatic therapy during pregnancy and lactation seem to be the appropriate treatment with minimal risk for the child and excellent outcome for the mother.

  13. Protein sieving characteristics of sub-20-nm pore size filters at varying ionic strength during nanofiltration of Coagulation Factor IX.

    PubMed

    Winkler, Clint J; Jorba, Nuria; Shitanishi, Kenneth T; Herring, Steven W

    2013-05-01

    Nanofiltration assures that protein therapeutics are free of adventitious agents such as viruses. Nanofilter pores must allow passage of protein drugs but be small enough to retain viruses. Five nanofilters have been evaluated to identify those that can be used interchangeably to yield a high purity Coagulation Factor IX product. When product preparations prior to nanofiltration were analyzed using electrophoresis, Western blot, liquid chromatography - tandem mass spectrometry and size exclusion HPLC, factor IX, inter - α - trypsin inhibitor and C4b binding protein (C4BP) were observed. C4BP was removed from product by all five nanofilters when nanofiltration was performed at physiological ionic strength. However, at high ionic strength, C4BP was removed by only two nanofilters. HPLC indicated that the Stokes radius of C4BP was larger at low ionic strength than at high ionic strength. The results suggest that C4BP exists in an open conformation at physiological ionic strength and is removed by nanofiltration whereas, at high ionic strength, the protein collapses to an extent that allows passage through some nanofilters. Manufacturers should be aware that protein contaminants in other nanofiltered protein drugs could behave similarly and conditions of nanofiltration must be evaluated to ensure consistent product purity.

  14. Double-stimuli-responsive spherical polymer brushes with a poly(ionic liquid) core and a thermoresponsive shell.

    PubMed

    Men, Yongjun; Drechsler, Markus; Yuan, Jiayin

    2013-11-01

    The synthesis of poly(ionic liquid) (PIL) nanoparticles grafted with a poly(N-isopropyl acrylamide) (PNIPAM) brush shell is reported, which shows responsiveness to temperature and ionic strength in an aqueous solution. The PIL nanoparticles are first prepared via aqueous dispersion polymerization of a vinyl imidazolium-based ionic liquid monomer, which is purposely designed to bear a distal atom transfer radical polymerization (ATRP) initiating group attached to the long alkyl chain via esterification reaction. The size of the PIL nanoparticles can be readily tuned from 25 to 120 nm by polymerization at different monomer concentrations. PNIPAM brushes are successfully grafted from the surface of the poly(ionic liquid) nanoparticles via ATRP. The stimuli-responsive behavior of the poly(ionic liquid) nanoparticles grafted with PNIPAM brushes (NP-g-PNIPAM) in aqueous phase is studied in detail. Enhanced colloidal stability of the NP-g-PNIPAM brush particles at high ionic strength compared to pure PIL nanoparticles at room temperature is achieved. Above the lower critical solution temperature (LCST) of PNIPAM, the brush particles remain stable, but a decrease in hydrodynamic radius due to the collapse of the PNIPAM brush onto the PIL nanoparticle surface is observed.

  15. Biomechanical stability of four fixation constructs for distal radius fractures.

    PubMed

    Capo, John T; Kinchelow, Tosca; Brooks, Kenneth; Tan, Virak; Manigrasso, Michaele; Francisco, Kristin

    2009-09-01

    Implants available for distal radius fracture fixation include dorsal nonlocked plating (DNLP), volar locked plating (VLP), radial-ulnar dual-column locked plating (DCPs), and locked intramedullary fixation (IMN). This study examines the biomechanical properties of these four different fixation constructs. In 28 fresh-frozen radii, a wedge osteotomy was performed, creating an unstable fracture model and the four fixation constructs employed (DNLP, VLP, DCPs, and IMN). Dorsal bending loads were applied and bending stiffness, load to yield 5 mm displacement, and ultimate failure were measured. Bending stiffness for VLP (16.7 N/mm) was significantly higher than for DNLP (6.8 N/mm), while IMN (12.6 N/mm) and DCPs (11.8 N/mm) were similar. Ultimate load to failure occurred at 278.2 N for the VLP, 245.7 N for the IMN, and 52.0 N for the DNLP. The VLP was significantly stronger than the DNLP and DCPs, and the IMN and DCPs were stronger than the DNLP. The VLP has higher average bending stiffness, ultimate bending strength, and resistance to 5 mm displacement than the other constructs and significantly higher ultimate bending strength than the DCPs and DNLP. There was no statistically significant difference between the VLP and IMN. VLP and IMN fixation of distal radius fractures can achieve comparable stability.

  16. Stellar Initial Mass Function: Trends With Galaxy Mass And Radius

    NASA Astrophysics Data System (ADS)

    Parikh, Taniya

    2017-06-01

    There is currently no consensus about the exact shape and, in particular, the universality of the stellar initial mass function (IMF). For massive galaxies, it has been found that near-infrared (NIR) absorption features, which are sensitive to the ratio of dwarf to giant stars, deviate from a Milky Way-like IMF; their modelling seems to require a larger fraction of low mass stars. There are now increasing results looking at whether the IMF varies not only with galaxy mass, but also radially within galaxies. The SDSS-IV/MaNGA integral-field survey will provide spatially resolved spectroscopy for 10,000 galaxies at R 2000 from 360-1000nm. Spectra of early-type galaxies were stacked to achieve high S/N which is particularly important for features in the NIR. Trends with galaxy radius and mass were compared to stellar population models for a range of absorption features in order to separate degeneracies due to changes in stellar population parameters, such as age, metallicity and element abundances, with potential changes in the IMF. Results for 611 galaxies show that we do not require an IMF steeper than Kroupa as a function of galaxy mass or radius based on the NaI index. The Wing-Ford band hints towards a steeper IMF at large radii however we do not have reliable measurements for the most massive galaxies.

  17. Complications of volar plating of distal radius fractures.

    PubMed

    Rampoldi, Michele; Marsico, Salvatore

    2007-12-01

    Open reduction and internal fixation has been shown to be effective in the treatment of unstable distal radius fractures. When a dorsal approach is used, extensor tendons rupture or irritation are frequent and well known complications. Complications associated with volar plate fixation have not been studied to the same extent. In this study a homogenous series of 90 patients treated by volar plate fixation were retrospectively evaluated, focusing on the complications observed. The overall rate of complications was 8% (7 cases). Tendon rupture or irritation of extensor (3 cases) and flexor tendons (2 cases) were the complications most frequently seen. All but one were clearly related to direct attritional damage of the tendon caused by the prominent edge of the plate or by protruding screw tips. Loss of reduction requiring repeat internal fixation was observed in one marginal shear fracture involving the lunate facet fragment. One patient had a carpal tunnel release owing to median nerve irritation. In this study, volar plate fixation appeared as a safe procedure in the management of unstable distal radius fractures, with a low rate of complications. Accurate placement of the plate and exact measurement of the screws may further minimize the incidence of complications. When radiographs reveal conditions that may predispose to tendon attritional lesions (prominent edge of the plate, dorsal protrusion of the screw tips) we strongly recommend early removal of the fixation device.

  18. Automated bone age assessment of older children using the radius

    NASA Astrophysics Data System (ADS)

    Tsao, Sinchai; Gertych, Arkadiusz; Zhang, Aifeng; Liu, Brent J.; Huang, Han K.

    2008-03-01

    The Digital Hand Atlas in Assessment of Skeletal Development is a large-scale Computer Aided Diagnosis (CAD) project for automating the process of grading Skeletal Development of children from 0-18 years of age. It includes a complete collection of 1,400 normal hand X-rays of children between the ages of 0-18 years of age. Bone Age Assessment is used as an index of skeletal development for detection of growth pathologies that can be related to endocrine, malnutrition and other disease types. Previous work at the Image Processing and Informatics Lab (IPILab) allowed the bone age CAD algorithm to accurately assess bone age of children from 1 to 16 (male) or 14 (female) years of age using the Phalanges as well as the Carpal Bones. At the older ages (16(male) or 14(female) -19 years of age) the Phalanges as well as the Carpal Bones are fully developed and do not provide well-defined features for accurate bone age assessment. Therefore integration of the Radius Bone as a region of interest (ROI) is greatly needed and will significantly improve the ability to accurately assess the bone age of older children. Preliminary studies show that an integrated Bone Age CAD that utilizes the Phalanges, Carpal Bones and Radius forms a robust method for automatic bone age assessment throughout the entire age range (1-19 years of age).

  19. Pion loop contribution to the electromagnetic pion charge radius

    SciTech Connect

    Roberts, C.D.; Bender, A.; Alkofer, R.

    1995-08-01

    There is a widely held misconception, based on a misrepresentation of the application of chiral perturbation theory, that the electromagnetic structure of the pion is dominated by the pion`s own pion-cloud. To clarify this the Global Color-symmetry Model (GCM), was used to calculate the electromagnetic charge radius of the pion. In this calculation the contributions from the quark core and pion loop were identified and compared. It was shown explicitly that the divergence of the charge radius in the chiral limit is due solely to the pion loop and that, at the physical value of the pion mass, this loop contributes less than 15% {l_angle}r{sub {pi}}{sup 2}{r_angle}; i.e. the quark core is the dominant determining characteristic for the pion. This suggests that quark-based models that fail to reproduce the m{sub {pi}} divergence of {l_angle}{sub {pi}}{sup 2}{r_angle} nevertheless incorporate the dominant characteristic of the pion: its quark core. The result`s studylend further support to the contention that, away from resonances, the dominant determining characteristic of kinematic and dynamical properties of hadrons is their quark core. A paper describing this work was submitted for publication.

  20. The New Proton Radius Experiment at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Gasparian, Ashot H.

    The proton charge radius (rp) is one of the most fundamental quantities in physics. Precise knowledge of its value is critically important for both nuclear and atomic physics-especially for the spectroscopy of atomic hydrogen. Recent high precision measurements of (rp) using the muonic hydrogen atom demonstrated up to eight standard deviations smaller value than the accepted average from all previous experiments performed with different methods. This fact triggered the well-known "proton charge radius puzzle" in hadronic physics. The PRad collaboration at Jefferson Lab for the last five years developed a novel magnetic-spectrometer-free e-p scattering experiment to address this "puzzle". The PRad experiment was successfully performed in May and June of 2016 at Jefferson Lab in which a large statistical and high quality experimental data set was collected. The specifics of the method, the experimental characteristics of the setup together with the first preliminary results from the current initial data analysis process are presented in this talk.

  1. The New Proton Radius Experiment (PRad) at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Gasparian, Ashot; PRad Collaboration at JLab Collaboration

    2017-01-01

    The proton charge radius (Rp) is one of the most fundamental quantities in physics. Precise knowledge of its value is critically important for both nuclear and atomic physics - especially for the spectroscopy of atomic hydrogen. Recent high precision measurements of Rp using the muonic hydrogen atom demonstrated up to eight standard deviations smaller value than the accepted average from all previous experiments performed with different methods. This fact triggered the well known ``proton charge radius puzzle'' in hadronic physics. The PRad collaboration at Jefferson Lab for the last four years developed a novel magnetic-spectrometer-free electron-proton scattering experiment to address this puzzle. The PRad experiment successfully performed in May and June of this year at Jefferson Lab collecting a large statistical and high quality experimental data set. The specifics of the method, the experimental characteristics of the setup together with the first preliminary results from the current data analysis process will be presented in this talk. This project is supported in part by the US NSF MRI award PHY-1229153, and US DOE awards: DE-FG02-03ER41240, DE-FG0203ER41231.

  2. Finite Larmor radius magnetohydrodynamics of the Rayleigh-Taylor instability

    NASA Astrophysics Data System (ADS)

    Huba, J. D.

    1996-07-01

    The evolution of the Rayleigh-Taylor instability is studied using finite Larmor radius (FLR) magnetohydrodynamic (MHD) theory. Finite Larmor radius effects are introduced in the momentum equation through an anisotropic ion stress tensor. Roberts and Taylor [Phys. Rev. Lett. 3, 197 (1962)], using fluid theory, demonstrated that FLR effects can stabilize the Rayleigh-Taylor instability in the short-wavelength limit (kLn≫1, where k is the wave number and Ln is the density gradient scale length). In this paper a linear mode equation is derived that is valid for arbitrary kLn. Analytic solutions are presented in both the short-wavelength (kLn≫1) and long-wavelength (kLn≪1) regimes, and numerical solutions are presented for the intermediate regime (kLn˜1). The long-wavelength modes are shown to be the most difficult to stabilize. More important, the nonlinear evolution of the Rayleigh-Taylor instability is studied using a newly developed two-dimensional (2-D) FLR MHD code. The FLR effects are shown to be a stabilizing influence on the Rayleigh-Taylor instability; the short-wavelength modes are the easiest to stabilize, consistent with linear theory. In the nonlinear regime, the FLR effects cause the ``bubbles and spikes'' that develop because of the Rayleigh-Taylor instability to convect along the density gradient and to tilt. Applications of this model to space and laboratory plasma phenomena are discussed.

  3. Two empirical regimes of the planetary mass-radius relation

    NASA Astrophysics Data System (ADS)

    Bashi, Dolev; Helled, Ravit; Zucker, Shay; Mordasini, Christoph

    2017-08-01

    Today, with the large number of detected exoplanets and improved measurements, we can reach the next step of planetary characterization. Classifying different populations of planets is not only important for our understanding of the demographics of various planetary types in the galaxy, but also for our understanding of planet formation. We explore the nature of two regimes in the planetary mass-radius (M-R) relation. We suggest that the transition between the two regimes of "small" and "large" planets occurs at a mass of 124 ± 7M⊕ and a radius of 12.1 ± 0.5R⊕. Furthermore, the M-R relation is R ∝ M0.55 ± 0.02 and R ∝ M0.01 ± 0.02 for small and large planets, respectively. We suggest that the location of the breakpoint is linked to the onset of electron degeneracy in hydrogen, and therefore to the planetary bulk composition. Specifically, it is the characteristic minimal mass of a planet that consists of mostly hydrogen and helium, and therefore its M-R relation is determined by the equation of state of these materials. We compare the M-R relation from observational data with the relation derived by population synthesis calculations and show that there is a good qualitative agreement between the two samples.

  4. GEM Detectors of Proton Charge Radius (PRad) Experiment

    NASA Astrophysics Data System (ADS)

    Bai, Xinzhan; PRad Collaboration

    2017-01-01

    The PRad experiment (E12-11-106) was recently performed at Jefferson Lab in Hall B. It was designed to measure the proton charge radius with high precision, through the elastic electron proton scattering process, using a non-magnetic-spectrometer method. PRad experiment reached very small ep scattering angles and thus it can see an unprecedented small four-momentum transfer squared region, Q2 from 2 ×10-4 to 0 . 1(GeV / c) 2 . This experiment measures the proton charge radius by extracting the electric form factor of proton with a sub-percent precision. A pair of world's largest GEM detectors, and a high resolution calorimeter(HyCal) were utilized in the experiment. In this talk, we will present the performance of GEM detectors achieved in the experiment, such as efficiency and other characteristics, and preliminary analysis results of the experimental data. This work is supported in part by NSF MRI award PHY-1229153, the U.S. Department of Energy under Contract No. DE-FG02-07ER41528, University of Virginia under Contract No. DE-FG02-03ER41240 and Thomas Jefferson National Laboratory.

  5. Artificial gravity: head movements during short-radius centrifugation

    NASA Technical Reports Server (NTRS)

    Young, L. R.; Hecht, H.; Lyne, L. E.; Sienko, K. H.; Cheung, C. C.; Kavelaars, J.

    2001-01-01

    Short-radius centrifugation is a potential countermeasure to long-term weightlessness. Unfortunately, head movements in a rotating environment induce serious discomfort, non-compensatory vestibulo-ocular reflexes, and subjective illusions of body tilt. In two experiments we investigated the effects of pitch and yaw head movements in participants placed supine on a rotating bed with their head at the center of rotation, feet at the rim. The vast majority of participants experienced motion sickness, inappropriate vertical nystagmus and illusory tilt and roll as predicted by a semicircular canal model. However, a small but significant number of the 28 participants experienced tilt in the predicted plane but in the opposite direction. Heart rate was elevated following one-second duration head turns. Significant adaptation occurred following a series of head turns in the light. Vertical nystagmus, motion sickness and illusory tilt all decreased with adaptation. Consequences for artificial gravity produced by short-radius centrifuges as a countermeasure are discussed. Grant numbers: NCC 9-58. c 2001. Elsevier Science Ltd. All rights reserved.

  6. Drift-Alfven vortices at the ion Larmor radius scale

    SciTech Connect

    Onishchenko, O. G.; Krasnoselskikh, V. V.

    2008-02-15

    The theory of nonlinear drift-Alfven waves with the spatial scales comparable to the ion Larmor radius is developed. It is shown that the set of equations describing the nonlinear dynamics of drift-Alfven waves in a quasistationary regime admits a solution in the form of a solitary dipole vortex. The vortex structures propagating perpendicular to the ambient magnetic field faster than the diamagnetic ion drift velocity possess spatial scales larger than the ion Larmor radius, and vice versa. The variation of the vortex impedance and spatial scale as the function of the vortex velocity is analyzed. It is shown that incorporation of the finite electron temperature effects results in the appearance of a minimum in the dependence of the vortex impedance on the vortex velocity. This leads to the existence of the vortex structures with the smallest impedance. These structures are probably the most favorable energetically and can easily be excited in space plasmas. The relevance of theoretical results obtained to the Cluster observations in the magnetospheric cusp and magnetosheath is stressed.

  7. Artificial gravity: head movements during short-radius centrifugation

    NASA Technical Reports Server (NTRS)

    Young, L. R.; Hecht, H.; Lyne, L. E.; Sienko, K. H.; Cheung, C. C.; Kavelaars, J.

    2001-01-01

    Short-radius centrifugation is a potential countermeasure to long-term weightlessness. Unfortunately, head movements in a rotating environment induce serious discomfort, non-compensatory vestibulo-ocular reflexes, and subjective illusions of body tilt. In two experiments we investigated the effects of pitch and yaw head movements in participants placed supine on a rotating bed with their head at the center of rotation, feet at the rim. The vast majority of participants experienced motion sickness, inappropriate vertical nystagmus and illusory tilt and roll as predicted by a semicircular canal model. However, a small but significant number of the 28 participants experienced tilt in the predicted plane but in the opposite direction. Heart rate was elevated following one-second duration head turns. Significant adaptation occurred following a series of head turns in the light. Vertical nystagmus, motion sickness and illusory tilt all decreased with adaptation. Consequences for artificial gravity produced by short-radius centrifuges as a countermeasure are discussed. Grant numbers: NCC 9-58. c 2001. Elsevier Science Ltd. All rights reserved.

  8. Corrective osteotomies of the radius: Grafting or not?

    PubMed Central

    Mugnai, Raffaele; Tarallo, Luigi; Lancellotti, Enrico; Zambianchi, Francesco; Di Giovine, Ettore; Catani, Fabio; Adani, Roberto

    2016-01-01

    AIM: To review the current literature regarding corrective osteotomies to provide the best evidence of the rule of bone grafting. METHODS: Our MEDLINE literature search included 280 studies using the following key words “Malunited distal radius fracture” and 150 studies using key words “Corrective osteotomy of the distal radius”. Inclusion criteria were: Malunited distal radial, extra articular fracture, volar locking plate, use of iliac bone graft (cancellous or corticocancellous), non-use of bone graft. Twelve studies met the inclusion criteria. RESULTS: Seven of the 12 studies considered, described the use of a graft; the remaining five studies didn’t use any graft. Type of malunion was dorsal in most of the studies. The healing time was comparable using the graft or not (mean 12.5 wk), ranging from 7.5 to 16 wk. The mean disabilities of the arm, shoulder and hand score improvement was 23 points both in the studies that used the graft and in those not using the graft. CONCLUSION: This review demonstrated that corrective osteotomy of extra-articular malunited fractures of the distal radius treated by volar locking plate does not necessarily require bone graft. PMID:26925385

  9. Ionic contamination detection. Final report

    SciTech Connect

    Benkovich, M.G.

    1994-04-01

    The effectiveness of Meter A and B for detecting ionic contamination was evaluated and compared on the following types of samples: (1) copper panels, (2) printed wiring boards with through-hold components (lCs), (3) printed wiring boards with surface-mounted components, and (4) mixed-technology printed wiring boards (both through-hole and surface-mount components). The extraction efficiency of the two meters was calculated

  10. Ionic Liquids for Advanced Materials

    DTIC Science & Technology

    2008-12-01

    electromechanical transducers and electrochromic devices to selective membranes for chemical and biological protection and fuel cells. ILs have moved from... glass transition temperature (Tg) with an increase in dielectric constant and ion content. ILs uniquely combine high dielectric constant, low...from 230-440%. Dissociation of ionic aggregates was observed at 85-88 °C in DMA experiments, and the glass transition temperatures increased with

  11. Mesoscopic organization in ionic liquids.

    PubMed

    Russina, Olga; Lo Celso, Fabrizio; Plechkova, Natalia; Jafta, Charl J; Appetecchi, Giovanni Battista; Triolo, Alessandro

    2017-06-01

    We discuss some published results and provide new observations concerning the high level of structural complexity that lies behind the nanoscale correlations in ionic liquids (ILs) and their mixtures with molecular liquids. It turns out that this organization is a consequence of the hierarchical construction on both spatial (from ångström to several nanometer) and temporal (from fraction of picosecond to hundreds of nanosecond) scales, which requires joint use of experimental and computational tools.

  12. Ionic Conduction in Nanocrystalline Materials

    DTIC Science & Technology

    2000-02-10

    photo- largely due to oxygen desorption from particle voltaic cells and as the photocatalyst in water surfaces. The latter interpretation...and Tuller [22] prepared dense (-95%) temperature, where bulk reduction was observed. At compacts of TiO2 with the anatase phase. The lower... TiO2 , evidence preparation. is mixed. Nanocrystalline rutile appears to exhibit higher ionic conductivity than single crystal rutile while

  13. Phase Behavior of Ionic Microgels

    NASA Astrophysics Data System (ADS)

    Gottwald, D.; Likos, C. N.; Kahl, G.; Löwen, H.

    2004-02-01

    We employ effective interaction potentials between spherical polyelectrolyte microgels in order to investigate theoretically the structure, thermodynamics, and phase behavior of ionic microgel solutions. Combining a genetic algorithm with accurate free energy calculations we are able to perform an unrestricted search of candidate crystal structures. Hexagonal, body-centered orthogonal, and trigonal crystals are found to be stable at high concentrations and charges of the microgels, accompanied by reentrant melting behavior and fluid-fcc-bcc transitions below the overlap concentration.

  14. Phase behavior of ionic microgels.

    PubMed

    Gottwald, D; Likos, C N; Kahl, G; Löwen, H

    2004-02-13

    We employ effective interaction potentials between spherical polyelectrolyte microgels in order to investigate theoretically the structure, thermodynamics, and phase behavior of ionic microgel solutions. Combining a genetic algorithm with accurate free energy calculations we are able to perform an unrestricted search of candidate crystal structures. Hexagonal, body-centered orthogonal, and trigonal crystals are found to be stable at high concentrations and charges of the microgels, accompanied by reentrant melting behavior and fluid-fcc-bcc transitions below the overlap concentration.

  15. Effect of A-site Non-stoichiometry on LSCF Cathodes

    SciTech Connect

    Templeton, Jared W.; Lu, Zigui; Stevenson, Jeffry W.; Hardy, John S.

    2011-09-01

    LSCF Cathodes were explored when effected with A-site non-stoichiometry. At 700-800 C, the operating temperatures of intermediate temperature (IT-) SOFCs have enabled the use of stainless steels in the SOFC framework and current collectors, allowing significant reductions in cost. However, the lower operating temperatures of IT-SOFC's also result in significant decreases in power densities of cells with LSM cathodes due to their high activation energies. LSCF is a mixed ionic electronic conducting perovskite that exhibits higher performance than LSM/YSZ composites and shows potential as a replacement cathode. This study investigates the effect of A-site stoichiometry on the performance of LSCF cathodes. Cell tests showed that A-site and Sr-deficient LSCF cathodes consistently outperformed stoichiometric LSCF cathodes, exhibiting up to 10% higher cell power densities. It was also observed that all stoichiometric, A-site, and Sr-deficient LSCF cathodes degraded over time at similar rates. Contributions of ohmic and electrode polarization losses to cell degradation rates were similar regardless of cathode composition.

  16. Ionic Liquids to Replace Hydrazine

    NASA Technical Reports Server (NTRS)

    Koelfgen, Syri; Sims, Joe; Forton, Melissa; Allan, Barry; Rogers, Robin; Shamshina, Julia

    2011-01-01

    A method for developing safe, easy-to-handle propellants has been developed based upon ionic liquids (ILs) or their eutectic mixtures. An IL is a binary combination of a typically organic cation and anion, which generally produces an ionic salt with a melting point below 100 deg C. Many ILs have melting points near, or even below, room temperature (room temperature ionic liquids, RTILs). More importantly, a number of ILs have a positive enthalpy of formation. This means the thermal energy released during decomposition reactions makes energetic ILs ideal for use as propellants. In this specific work, to date, a baseline set of energetic ILs has been identified, synthesized, and characterized. Many of the ILs in this set have excellent performance potential in their own right. In all, ten ILs were characterized for their enthalpy of formation, density, melting point, glass transition point (if applicable), and decomposition temperature. Enthalpy of formation was measured using a microcalorimeter designed specifically to test milligram amounts of energetic materials. Of the ten ILs characterized, five offer higher Isp performance than hydrazine, ranging between 10 and 113 seconds higher than the state-of-the-art propellant. To achieve this level of performance, the energetic cations 4- amino-l,2,4-triazolium and 3-amino-1,2,4-triazolium were paired with various anions in the nitrate, dicyanamide, chloride, and 3-nitro-l,2,4-triazole families. Protonation, alkylation, and butylation synthesis routes were used for creation of the different salts.

  17. Long range electrostatic forces in ionic liquids.

    PubMed

    Gebbie, Matthew A; Smith, Alexander M; Dobbs, Howard A; Lee, Alpha A; Warr, Gregory G; Banquy, Xavier; Valtiner, Markus; Rutland, Mark W; Israelachvili, Jacob N; Perkin, Susan; Atkin, Rob

    2017-01-19

    Ionic liquids are pure salts that are liquid under ambient conditions. As liquids composed solely of ions, the scientific consensus has been that ionic liquids have exceedingly high ionic strengths and thus very short Debye screening lengths. However, several recent experiments from laboratories around the world have reported data for the approach of two surfaces separated by ionic liquids which revealed remarkable long range forces that appear to be electrostatic in origin. Evidence has accumulated demonstrating long range surface forces for several different combinations of ionic liquids and electrically charged surfaces, as well as for concentrated mixtures of inorganic salts in solvent. The original interpretation of these forces, that ionic liquids could be envisioned as "dilute electrolytes," was controversial, and the origin of long range forces in ionic liquids remains the subject of discussion. Here we seek to collate and examine the evidence for long range surface forces in ionic liquids, identify key outstanding questions, and explore possible mechanisms underlying the origin of these long range forces. Long range surface forces in ionic liquids and other highly concentrated electrolytes hold diverse implications from designing ionic liquids for energy storage applications to rationalizing electrostatic correlations in biological self-assembly.

  18. Radiation Chemistry and Photochemistry of Ionic Liquids

    SciTech Connect

    Wishart, J.F.; Takahaski, K.

    2010-12-01

    As our understanding of ionic liquids and their tunable properties has grown, it is possible to see many opportunities for ionic liquids to contribute to the sustainable use of energy. The potential safety and environmental benefits of ionic liquids, as compared to conventional solvents, have attracted interest in their use as processing media for the nuclear fuel cycle. Therefore, an understanding of the interactions of ionizing radiation and photons with ionic liquids is strongly needed. However, the radiation chemistry of ionic liquids is still a relatively unexplored topic although there has been a significant increase in the number of researchers in the field recently. This article provides a brief introduction to ionic liquids and their interesting properties, and recent advances in the radiation chemistry and photochemistry of ionic liquids. In this article, we will mainly focus on excess electron dynamics and radical reaction dynamics. Because solvation dynamics processes in ionic liquids are much slower than in molecular solvents, one of the distinguishing characteristics is that pre-solvated electrons play an important role in ionic liquid radiolysis. It will be also shown that the reaction dynamics of radical ions is significantly different from that observed in molecular solvents because of the Coulombic screening effects and electrostatic interactions in ionic liquids.

  19. Radius of Curvature Measurements: An Independent Look at Accuracy Using Novel Optical Metrology

    NASA Technical Reports Server (NTRS)

    Taylor, Bryon; Kahan, Mark; Russell, Kevin (Technical Monitor)

    2002-01-01

    The AMSD (Advanced Mirror System Demonstrator) program mirror specifications include the ability to manufacture the mirror to a radius of curvature of 10 m +/- 1 mm and to control its radius at 30K to the same specification. Therefore, it is necessary for the Government Team to be able to measure mirror radius of curvature to an accuracy of better than 0.5 mm. This presentation discusses a novel optical metrology system for measuring radius of curvature.

  20. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic contact lens radius measuring device... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1430 Ophthalmic contact lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device...

  1. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic contact lens radius measuring device... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1430 Ophthalmic contact lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device...

  2. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic contact lens radius measuring device... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1430 Ophthalmic contact lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device...

  3. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic contact lens radius measuring device... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1430 Ophthalmic contact lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device...

  4. Post-traumatic osteonecrosis of the lunate after fracture of the distal radius.

    PubMed

    Nakanishi, Akito; Yajima, Hiroshi; Kisanuki, Osamu

    2014-12-01

    We present a case of post-traumatic osteonecrosis of the lunate after fracture of the distal radius. Post-traumatic osteonecrosis of the carpal lunate after a fracture of the distal radius has, to our knowledge, not been reported previously. We treated the patient with vascularised bone graft from the distal radius, with a satisfactory result.

  5. Ionic strength effect on molecular structure of hyaluronic acid investigated by flow field-flow fractionation and multiangle light scattering.

    PubMed

    Kim, Bitnara; Woo, Sohee; Park, Young-Soo; Hwang, Euijin; Moon, Myeong Hee

    2015-02-01

    This study describes the effect of ionic strength on the molecular structure of hyaluronic acid (HA) in an aqueous solution using flow field-flow fractionation and multiangle light scattering (FlFFF-MALS). Sodium salts of HA (NaHA) raw materials (∼2 × 10(6) Da) dispersed in different concentrations of NaCl prepared by repeated dilution/ultrafiltration procedures were examined in order to study conformational changes in terms of the relationship between the radius of gyration and molecular weight (MW) and molecular weight distribution (MWD) of NaHA in solution. This was achieved by varying the ionic strength of the carrier solution used in a frit-inlet asymmetrical FlFFF (FIAF4) channel. Experiments showed that the average MW of NaHA increased as the ionic strength of the NaHA solution decreased due to enhanced entanglement or aggregation of HA molecules. Relatively large molecules (greater than ∼5 MDa) did not show a large increase in RMS radius value as the NaCl concentration decreased. Conversely, smaller species showed larger changes, suggesting molecular expansion at lower ionic strengths. When the ionic strength of the FlFFF carrier solution was decreased, the HA species in a salt-rich solution (0.2 M NaCl) underwent rapid molecular aggregation during FlFFF separation. However, when salt-depleted HA samples (I = 4.66∼0.38 mM) were analyzed with FFF carrier solutions of a high ionic strength, the changes in both molecular structure and size were somewhat reversible, although there was a delay in correction of the molecular structure.

  6. Enhancement and Mitigation Mechanisms of Protein Fouling of Ultrafiltration Membranes under Different Ionic Strengths.

    PubMed

    Miao, Rui; Wang, Lei; Mi, Na; Gao, Zhe; Liu, Tingting; Lv, Yongtao; Wang, Xudong; Meng, Xiaorong; Yang, Yongzhe

    2015-06-02

    To determine further the enhancement and mitigation mechanisms of protein fouling, filtration experiments were carried out with polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes and bovine serum albumin (BSA) over a range of ionic strengths. The interaction forces, the adsorption behavior of BSA on the membrane surface, and the structure of the BSA adsorbed layers at corresponding ionic strengths were investigated. Results indicate that when the ionic strength increased from 0 to 1 mM, there was a decrease in the PVDF-BSA and BSA-BSA electrostatic repulsion forces, resulting in a higher deposition rate of BSA onto the membrane surface, and the formation of a denser BSA layer; consequently, membrane fouling was enhanced. However, at ionic strengths of 10 and 100 mM, membrane fouling and the BSA removal rate decreased significantly. This was mainly due to the increased hydration repulsion forces, which caused a decrease in the PVDF-BSA and BSA-BSA interaction forces accompanied by a decreased hydrodynamic radius and increased diffusion coefficient of BSA. Consequently, BSA passed more easily through the membrane and into permeate. There was less accumulation of BSA on the membrane surface. A more nonrigid and open structure BSA layer was formed on the membrane surface.

  7. Effects of chloride and ionic strength on physical morphology, dissolution, and bacterial toxicity of silver nanoparticles.

    PubMed

    Chambers, Bryant A; Afrooz, A R M Nabiul; Bae, Sungwoo; Aich, Nirupam; Katz, Lynn; Saleh, Navid B; Kirisits, Mary Jo

    2014-01-01

    In this study, we comprehensively evaluate chloride- and ionic-strength-mediated changes in the physical morphology, dissolution, and bacterial toxicity of silver nanoparticles (AgNPs), which are one of the most-used nanomaterials. The findings isolate the impact of ionic strength from that of chloride concentration. As ionic strength increases, AgNP aggregation likewise increases (such that the hydrodynamic radius [HR] increases), fractal dimension (Df) strongly decreases (providing increased available surface relative to suspensions with higher Df), and the release of Ag(aq) increases. With increased Ag(+) in solution, Escherichia coli demonstrates reduced tolerance to AgNP exposure (i.e., toxicity increases) under higher ionic strength conditions. As chloride concentration increases, aggregates are formed (HR increases) but are dominated by AgCl(0)(s) bridging of AgNPs; relatedly, Df increases. Furthermore, AgNP dissolution strongly increases under increased chloride conditions, but the dominant, theoretical, equilibrium aqueous silver species shift to negatively charged AgClx((x-1)-) species, which appear to be less toxic to E. coli. Thus, E. coli demonstrates increased tolerance to AgNP exposure under higher chloride conditions (i.e., toxicity decreases). Expression measurements of katE, a gene involved in catalase production to alleviate oxidative stress, support oxidative stress in E. coli as a result of Ag(+) exposure. Overall, our work indicates that the environmental impacts of AgNPs must be evaluated under relevant water chemistry conditions.

  8. Inductive voltage adder (IVA) for submillimeter radius electron beam

    SciTech Connect

    Mazarakis, M.G.; Poukey, J.W.; Maenchen, J.E.

    1996-12-31

    The authors have already demonstrated the utility of inductive voltage adder accelerators for production of small-size electron beams. In this approach, the inductive voltage adder drives a magnetically immersed foilless diode to produce high-energy (10--20 MeV), high-brightness pencil electron beams. This concept was first demonstrated with the successful experiments which converted the linear induction accelerator RADLAC II into an IVA fitted with a small 1-cm radius cathode magnetically immersed foilless diode (RADLAC II/SMILE). They present here first validations of extending this idea to mm-scale electron beams using the SABRE and HERMES-III inductive voltage adders as test beds. The SABRE experiments are already completed and have produced 30-kA, 9-MeV electron beams with envelope diameter of 1.5-mm FWHM. The HERMES-III experiments are currently underway.

  9. EFFECTIVE INNER RADIUS OF TILTED BLACK HOLE ACCRETION DISKS

    SciTech Connect

    Fragile, P. Chris

    2009-12-01

    One of the primary means of determining the spin a of an astrophysical black hole is by actually measuring the inner radius r {sub in} of a surrounding accretion disk and using that to infer a. By comparing a number of different estimates of r {sub in} from simulations of tilted accretion disks with differing black hole spins, we show that such a procedure can give quite wrong answers. Over the range 0 <= a/M <= 0.9, we find that, for moderately thick disks (H/r approx 0.2) with modest tilt (15 deg.), r {sub in} is nearly independent of spin. This result is likely dependent on tilt, such that for larger tilts, it may even be that r {sub in} would increase with increasing spin. In the opposite limit, we confirm through numerical simulations of untilted disks that, in the limit of zero tilt, r {sub in} recovers approximately the expected dependence on a.

  10. Measuring the Radius and Mass of Planet Nine

    NASA Astrophysics Data System (ADS)

    Schneider, J.

    2017-10-01

    Batygin & Brown (2016) suggested the existence of a new planet in our solar system that is supposed to be responsible for the perturbation of eccentric orbits of small outer bodies. The main challenge now is to detect and characterize this putative body. Here, we investigate the principles of the determination of its physical parameters, mainly its mass and radius. For that purpose, we concentrate on two methods: stellar occultations and gravitational microlensing effects (amplification, deflection, and time delay). We estimate the main characteristics of a possible occultation or gravitational effects: flux variation of a background star, duration, and probability of occurrence. We also investigate the additional benefits of direct imaging and of an occultation.

  11. Evolution of neck radius and relaxation of coalescing nanoparticles

    NASA Astrophysics Data System (ADS)

    McCarthy, David N.; Brown, Simon A.

    2009-08-01

    We use kinetic Monte Carlo simulations to investigate the coalescence of fcc nanoparticles via lattice-based diffusion of surface atoms. The radius of the neck region connecting the two nanoparticles is found to develop with characteristic power laws rtilde ta with atilde (1)/(3) and atilde (1)/(6) for the early and intermediate stages of coalescence, respectively. For late coalescence stages, when the nucleation of new atomic layers on nanoparticle facets is required for further coalescence, the nanoparticle size, temperature, and nanoparticle orientation all influence the development of the neck. In contrast, classical theory predicts an approximately constant value of a(˜(1)/(6)) . We also examine the temperature dependence of the equilibration times for relaxing nanoparticles and distinguish the limiting processes to be nucleation of new germs on a facet and/or the detachment of atoms from atomic layers.

  12. Severely comminuted radius fracture presenting as a signature patterned injury

    PubMed Central

    Jain, Saurabh; Rajan, Sunil; Srivastava, Abhishek

    2016-01-01

    Dilemma still prevails, regarding the exact management of mangled extremity injuries between limb salvage versus amputation, each having there own set of complications. We here present a case of severely comminuted fractures of radius (bag of bones) along with the multiple criss-cross shaped lacerated wounds on the forearm and wrist presenting as a “signature pattern injury” caused by entrapment of the limb in the concrete mixer. MESS score of patient was 8, a score valid for amputation, but contrary, we successfully salvaged the patient's limb with use of radio-carpal distracter. Management of mangled injuries should be individualized, with due consideration to the mechanism and force of injury, associated injuries, and the patient profile. PMID:27053813

  13. Radius and limb darkening of Titan from speckle imaging

    NASA Astrophysics Data System (ADS)

    Nisenson, P.; Apt, J.; Horowitz, P.; Goody, R.

    1981-11-01

    The radius R of Titan is determined from ground-based, visible light observations using a two-dimensional speckle imaging technique. The value of R is found to depend on the limb-darkening exponent alpha, which is used in modeling the observed disk, and it is determined that the probable range extends from R values of 2680 + or - 100 km for alpha of 0.6 to 2900 + or - 100 km for alpha of 1.3. This range is in agreement with Voyager 1 and Pioneer Saturn observations. It is suggested that spatial resolution may be doubled by using a grid of 256 x 256 pixels at the time the image is digitized, and that further improvements are possible with speckle-reduction techniques under development.

  14. Radius of the ρ meson determined from its decay constant

    NASA Astrophysics Data System (ADS)

    Krutov, A. F.; Polezhaev, R. G.; Troitsky, V. E.

    2016-02-01

    We present a unified model describing electroweak properties of the π and ρ mesons. Using a general method of the relativistic parametrization of matrix elements of local operators, adjusted for the nondiagonal in the total angular momentum case, we calculate the ρ -meson lepton-decay constant fρ using the same parameters of free constituent quarks that have ensured exclusively good results for the π meson previously. The only free parameter, characterizing quark interactions, which include an additional spin-spin contribution and hence differ from the π -meson case, is fixed by matching the decay constant to its experimental value. The mean square charge radius is calculated, ⟨rρ2⟩=(0.56 ±0.04 ) fm2 . This result confirms, for the ρ -meson case, the conjecture of equality between electromagnetic and strong radii of hadrons. This conjecture was tested previously for proton, π and K mesons.

  15. Biomechanics and biology of plate fixation of distal radius fractures.

    PubMed

    Freeland, Alan E; Luber, Kurre T

    2005-08-01

    The fracture management principles of anatomic or near anatomic reduction, fracture stabilization, minimal operative trauma, and early joint motion are paramount in man-aging unstable distal radial fractures. The operative approach and plate selection should correlate with the fracture configuration. Plates have the advantages of providing secure fixation throughout the entire healing process without protruding wires or pins and allowing early and intensive forearm, wrist, and digital exercises. Disadvantages include additional operative trauma, including fragment devascularization; some additional risk of wrist stiffness; occasional tendon rupture; and at times, the need for plate removal. New developments in plate and screw design and operative strategies, fragment specific fixation, and plate strength have improved results with plate fixation. Fixed angle blades and locking screws and pegs enhance overall plate stability, support the articular surface of the distal radius, and are effective in fractures occurring in osteopenic bone.

  16. Severely comminuted radius fracture presenting as a signature patterned injury.

    PubMed

    Jain, Saurabh; Rajan, Sunil; Srivastava, Abhishek

    2016-01-01

    Dilemma still prevails, regarding the exact management of mangled extremity injuries between limb salvage versus amputation, each having there own set of complications. We here present a case of severely comminuted fractures of radius (bag of bones) along with the multiple criss-cross shaped lacerated wounds on the forearm and wrist presenting as a "signature pattern injury" caused by entrapment of the limb in the concrete mixer. MESS score of patient was 8, a score valid for amputation, but contrary, we successfully salvaged the patient's limb with use of radio-carpal distracter. Management of mangled injuries should be individualized, with due consideration to the mechanism and force of injury, associated injuries, and the patient profile.

  17. Massive radius-dependent flow slippage in carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Siria, Alessandro; Secchi, Eleonora; Marbach, Sophie; Niguès, Antoine; Stein, Derek; Bocquet, Lydéric

    2016-11-01

    Nanofluidics is the frontier where the continuum picture of fluid mechanics confronts the atomic nature of matter. Recent reports indicate that carbon nanotubes exhibit exceptional water transport properties due to nearly frictionless interfaces and this has stimulated interest in nanotube-based membranes for desalination, nano-filtration, and energy harvesting. However, the fundamental mechanisms of water transport inside nanotubes and at water-carbon interfaces remain controversial, as existing theories fail to provide a satisfying explanation for the limited experimental results. We report a study of water jets emerging from single nanotubes made of carbon and boron-nitride materials. Our experiments reveal extensive and radius-dependent surface slippage in carbon nanotubes (CNT). In stark contrast, boron-nitride nanotubes (BNNT), which are crystallographically similar to CNTs but electronically different, exhibit no slippage. This shows that slippage originates in subtle atomic-scale details of the solid-liquid interface. ERC StG - NanoSOFT.

  18. First principles approach to ionicity of fragments

    NASA Astrophysics Data System (ADS)

    Pilania, Ghanshyam; Liu, Xiang-Yang; Valone, Steven M.

    2015-02-01

    We develop a first principles approach towards the ionicity of fragments. In contrast to the bond ionicity, the fragment ionicity refers to an electronic property of the constituents of a larger system, which may vary from a single atom to a functional group or a unit cell to a crystal. The fragment ionicity is quantitatively defined in terms of the coefficients of contributing charge states in a superposition of valence configurations of the system. Utilizing the constrained density functional theory-based computations, a practical method to compute the fragment ionicity from valence electron charge densities, suitably decomposed according to the Fragment Hamiltonian (FH) model prescription for those electron densities, is presented for the first time. The adopted approach is illustrated using BeO, MgO and CaO diatomic molecules as simple examples. The results are compared and discussed with respect to the bond ionicity scales of Phillips and Pauling.

  19. Titanium elastic nailing radius and ulna fractures in adolescents.

    PubMed

    Wall, Lindley; O'Donnell, June C; Schoenecker, Perry L; Keeler, Kathryn A; Dobbs, Matthew B; Luhmann, Scott J; Gordon, J Eric

    2012-09-01

    Over the last 40 years, anatomic reduction with plate stabilization has become the standard in adult patients with diaphyseal fractures of the radius and ulna. When operative fixation has been indicated in skeletally immature patients with these fractures, a variety of techniques have been reported, with intramedullary fixation becoming increasingly accepted. There is currently significant variability in the treatment of adolescents with forearm fractures. The purpose of this study was to investigate the clinical and radiographic outcomes in the adolescent population after intramedullary fixation of both bone forearm fractures. A retrospective review identified 32 patients 12-18 years of age who had undergone intramedullary fixation of both forearm bones in the past 20 years at our institution. Galeazzi, Monteggia, radial head, and distal metaphyseal fractures were excluded. Radiographic evaluation was performed to determine union and postoperative radial bow. Clinical follow-up was carried out for postoperative complications and range of motion of the wrist, forearm, and elbow. The mean age of the patients was 14.1 years. A total of 19 fractures were closed injuries, nine were grade 1, three were grade 2, and one fracture was a grade 3b. Of the patients, 15.6% had limited postoperative range of motion. All patients in the older age group, 15-18 years of age, had a normal range of motion. A decrease in radial bow was not associated with limitation in motion. There was a 98% union rate, and all unions occurred by 7.5 months. Only three major complications occurred, two refractures and one ulnar hardware migration, and subsequent radius nonunion occurred in the one grade 3b injury. Flexible intramedullary nailing of both bone forearm fractures provides reliable bony union and excellent postoperative clinical results in adolescents. Level of evidence, IV.

  20. [Manifestation of Dupuytren nodules following fracture of the distal radius].

    PubMed

    Wichelhaus, Alice; Wendt, M; Mielsch, N; Gradl, G; Mittlmeier, T

    2015-02-01

    The aim of this study is to evaluate the incidence of post-traumatic development of Dupuytren nodules in distal radius fractures treated operatively. In 2 prospective randomised studies for operative treatment of distal radius fractures, the formation of Dupuytren nodules was registered. One of the exclusion criteria was a pre-existing Dupuytren's disease at the date of trauma. In addition to the notification of the development of Dupuytren nodules, signs of a complex regional pain syndrome were registered as well as the wrist function, level of pain and grip strength. The Castaing and the Gartland and Werley scores were assessed. The clinical outcomes of patients with and without Dupuytren nodules were compared. 239 of 275 (87%) of the patients could be examined 1 year after the operation, consisting of 32 men and 207 women with a median age of 64.2 years. The patients with Dupuytren nodules were re-evaluated after 16-60 months (median 41.8) for progression of the disease. 21 patients (8.7%) developed changes of the palmar aponeurosis. In 20 patients nodules were stated, one patient showed a cord at the fourth ray of the injured hand. 19 out of 21 patients were female (90.5%). At re-evaluation after 41.8 months (16-60) progression could not be noted nor could similar changes be seen on the contralateral side. Patients with Dupuytren nodules were not handicapped in their hand function. 3 patients (14.3%) revealed a positive family history for Dupuytren's disease. Abuse of alcohol or diabetes was not present in any of the patients with Dupuytren nodules, 7 (33%) were smokers. The occurrence of Dupyutren nodules can be triggered by a trauma or operation. It may be speculated that these nodules are an entity of their own as no progression of the contracture could be seen during the follow-up period. © Georg Thieme Verlag KG Stuttgart · New York.

  1. Binding of Alpha-Bungarotoxin to Single Identified Neurons of ’Aplysia’ which have Different Ionic Responses to Acetylcholine,

    DTIC Science & Technology

    1976-09-01

    Identifiable Aplysia neurons have one or more of three different ionic responses to acetylcholine, due to Na, Cl, and K conductance increases... Aplysia acetylcholine receptors. Thus the inhibition of the Na response by hexamethonium may be a result of the binding to a site which prevent the conductance change rather than preventing acetylcholine from binding to its receptor.

  2. Facilitated Ion Transport in Smectic Ordered Ionic Liquid Crystals.

    PubMed

    Lee, Jin Hong; Han, Kee Sung; Lee, Je Seung; Lee, Albert S; Park, Seo Kyung; Hong, Sung Yun; Lee, Jong-Chan; Mueller, Karl T; Hong, Soon Man; Koo, Chong Min

    2016-11-01

    A novel ionic mixture of an imidazolium-based room-temperature ionic liquid containing ethylene-oxide-functionalized phosphite anions is fabricated, which, when doped with lithium salt, self-assembles into a smectic-ordered ionic liquid crystal through Coulombic interactions between the ion species. Interestingly, the smectic order in the ionic-liquid-crystal ionogel facilitates ionic transport.

  3. Highly Selective Ionic Block Copolymer Membranes

    DTIC Science & Technology

    2010-11-10

    commonly used ionic polymer membrane in fuel cells ) as a function of methanol solution concentration using time-resolved FTIR-ATR spectroscopy. This...this field of study. These results suggest that methanol fuel cell performance and efficiency can be improved by developing new ionic polymers that...methanol sorption in the membrane and not diffusion. The typical assumption in ionic polymer development for the methanol fuel cell is that the diffusion

  4. Early Events in Ionic Liquid Radiation Chemistry

    SciTech Connect

    Wishart, J.F.; Cook, A.; Rimmer, R.D.; Gohdo, M.

    2010-09-14

    Ionic liquids are interesting and useful materials whose solvation time scales are up to thousands of times longer than in conventional solvents. The extended lifetimes of pre-solvated electrons and other energetic species in ionic liquids has profound consequences for the radiolytic product distributions and reactivity patterns. We use a newly developed, multiplexed variation of pulse-probe spectroscopy to measure the kinetics of the early dynamical and reactive events in ionic liquids.

  5. Microemulsions with an ionic liquid surfactant and room temperature ionic liquids as polar pseudo-phase.

    PubMed

    Zech, Oliver; Thomaier, Stefan; Bauduin, Pierre; Rück, Thomas; Touraud, Didier; Kunz, Werner

    2009-01-15

    In this investigation we present for the first time microemulsions comprising an ionic liquid as surfactant and a room-temperature ionic liquid as polar pseudo-phase. Microemulsions containing the long- chain ionic liquid1-hexadecyl-3-methyl-imidazolium chloride ([C16mim][Cl]) as surfactant, decanol as cosurfactant, dodecaneas continuous phase and room temperature ionic liquids (ethylammonium nitrate (EAN) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim

  6. Maximum wind radius estimated by the 50 kt radius: improvement of storm surge forecasting over the western North Pacific

    NASA Astrophysics Data System (ADS)

    Takagi, Hiroshi; Wu, Wenjie

    2016-03-01

    Even though the maximum wind radius (Rmax) is an important parameter in determining the intensity and size of tropical cyclones, it has been overlooked in previous storm surge studies. This study reviews the existing estimation methods for Rmax based on central pressure or maximum wind speed. These over- or underestimate Rmax because of substantial variations in the data, although an average radius can be estimated with moderate accuracy. As an alternative, we propose an Rmax estimation method based on the radius of the 50 kt wind (R50). Data obtained by a meteorological station network in the Japanese archipelago during the passage of strong typhoons, together with the JMA typhoon best track data for 1990-2013, enabled us to derive the following simple equation, Rmax = 0.23 R50. Application to a recent strong typhoon, the 2015 Typhoon Goni, confirms that the equation provides a good estimation of Rmax, particularly when the central pressure became considerably low. Although this new method substantially improves the estimation of Rmax compared to the existing models, estimation errors are unavoidable because of fundamental uncertainties regarding the typhoon's structure or insufficient number of available typhoon data. In fact, a numerical simulation for the 2013 Typhoon Haiyan as well as 2015 Typhoon Goni demonstrates a substantial difference in the storm surge height for different Rmax. Therefore, the variability of Rmax should be taken into account in storm surge simulations (e.g., Rmax = 0.15 R50-0.35 R50), independently of the model used, to minimize the risk of over- or underestimating storm surges. The proposed method is expected to increase the predictability of major storm surges and to contribute to disaster risk management, particularly in the western North Pacific, including countries such as Japan, China, Taiwan, the Philippines, and Vietnam.

  7. Evidence of enhanced radius of Hoyle rotational state in12C inelastic scattering

    NASA Astrophysics Data System (ADS)

    Ito, M.

    2017-06-01

    Nuclear radius of three α rotational state in12C with a life time of 10-21 second, which has been expected to have much more extended radius than the ground12C nucleus, is speculated from systematic analysis of the differential cross section of the α +12C inelastic scattering. Present analysis predicts about 0.6 ∼ 1.0 fm enhancement in the matter radius of the three α rotational state in comparison to the normal radius of the ground state. The spatial extension of the three α rotational state is comparable to the extended radius observed in the neutron halo phenomena.

  8. Membrane separation of ionic liquid solutions

    DOEpatents

    Campos, Daniel; Feiring, Andrew Edward; Majumdar, Sudipto; Nemser, Stuart

    2015-09-01

    A membrane separation process using a highly fluorinated polymer membrane that selectively permeates water of an aqueous ionic liquid solution to provide dry ionic liquid. Preferably the polymer is a polymer that includes polymerized perfluoro-2,2-dimethyl-1,3-dioxole (PDD). The process is also capable of removing small molecular compounds such as organic solvents that can be present in the solution. This membrane separation process is suitable for drying the aqueous ionic liquid byproduct from precipitating solutions of biomass dissolved in ionic liquid, and is thus instrumental to providing usable lignocellulosic products for energy consumption and other industrial uses in an environmentally benign manner.

  9. Thermodynamics and micro heterogeneity of ionic liquids.

    PubMed

    Gomes, Margarida F Costa; Lopes, J N Canongia; Padua, A A H

    2010-01-01

    The high degree of organisation in the fluid phase of room-temperature ionic liquids has major consequences on their macroscopic properties, namely on their behaviour as solvents. This nanoscale self-organisation is the result of an interplay between two types of interaction in the liquid phase - Coulomb and van der Waals - that eventually leads to the formation of medium-range structures and the recognition of some ionic liquids as composed of a high-charge density, cohesive network permeated by low-charge density regions.In this chapter, the structure of the ionic liquids will be explored and some of their consequences to the properties of ionic liquids analyzed.

  10. Measurement of ulnar variance and radial inclination on X-rays of healed distal radius fractures. With the axis of the distal radius or ulna?

    PubMed

    Thuysbaert, Gilles; Ringburg, Akkie; Petronilia, Steven; Vanden Berghe, Alex; Hollevoet, Nadine

    2015-06-01

    Ulnar variance and radial inclination are radiological parameters frequently used to evaluate displacement of distal radius fractures. In most studies measurements are based on the long central axis of the distal radius, although the axis of the distal ulna can also be used. The purpose of this study was to determine which axis is more reliable. Four observers performed measurements on standard anteroposterior digital wrist X-rays of 20 patients taken 1 and 2 months after sustaining an extra-articular distal radius fracture. Intraobserver reliability was similar with both methods. No difference was found in interobserver reliability between both methods for ulnar variance, but for radial inclination it was better with the axis through the radius. Measurements on two X-rays of the same wrist taken at a different moment were similar with both methods. It can be concluded that the central axis of the distal radius can remain the basis to determine ulnar variance and radial inclination.

  11. On catalysis by ionic liquids.

    PubMed

    Chakraborti, Asit K; Roy, Sudipta Raha

    2009-05-27

    A molecular level mechanism of catalysis by an ionic liquid (IL) is proposed as an "electrophile nucleophile dual activation" through a "relay of cooperative hydrogen bonds and charge-charge interactions". Spectroscopic ((1)H NMR and IR) studies were used to probe the involvement of the C-2 hydrogen and the AcO(-) anion of [bmim][OAc] in the catalysis for O-t-Boc formation. Ion fishing by MALDI-TOF-TOF MS and MS-MS established the hydrogen bonded clusters.

  12. Actinide chemistry in ionic liquids.

    PubMed

    Takao, Koichiro; Bell, Thomas James; Ikeda, Yasuhisa

    2013-04-01

    This Forum Article provides an overview of the reported studies on the actinide chemistry in ionic liquids (ILs) with a particular focus on several fundamental chemical aspects: (i) complex formation, (ii) electrochemistry, and (iii) extraction behavior. The majority of investigations have been dedicated to uranium, especially for the 6+ oxidation state (UO2(2+)), because the chemistry of uranium in ordinary solvents has been well investigated and uranium is the most abundant element in the actual nuclear fuel cycles. Other actinides such as thorium, neptunium, plutonium, americium, and curiumm, although less studied, are also of importance in fully understanding the nuclear fuel engineering process and the safe geological disposal of radioactive wastes.

  13. Ionic Reactions of Atmospheric Importance.

    DTIC Science & Technology

    1984-08-31

    been made by Dr. Erich Alge. (v) I INTRODUCTIN Our major commitment under the terms of the grant is to study a range of ionic processes which can occur...HCO+ , N2 H+ AND CH5+ AT 95 AND 300 K USING THE FALP APPARATUS Nigel G. Adams, David Smith and Erich Alg’ Department of Space Researcn, University of...H.M. Rosenstock, K. Draxl, B.W. Steiner and J.T. Herron, 3. Phys. and Chem. Ref. Data, 6, 1977 Supplement No. 1. 5. D. K. Bohme, A.B. Rakshit and A

  14. Ionic Structure at Dielectric Interfaces

    NASA Astrophysics Data System (ADS)

    Jing, Yufei

    The behavior of ions in liquids confined between macromolecules determines the outcome of many nanoscale assembly processes in synthetic and biological materials such as colloidal dispersions, emulsions, hydrogels, DNA, cell membranes, and proteins. Theoretically, the macromolecule-liquid boundary is often modeled as a dielectric interface and an important quantity of interest is the ionic structure in a liquid confined between two such interfaces. The knowledge gleaned from the study of ionic structure in such models can be useful in several industrial applications, such as biosensors, lithium-ion batteries double-layer supercapacitors for energy storage and seawater desalination. Electrostatics plays a critical role in the development of such functional materials. Many of the functions of these materials, result from charge and composition heterogeneities. There are great challenges in solving electrostatics problems in heterogeneous media with arbitrary shapes because electrostatic interactions remains unknown but depend on the particular density of charge distributions. Charged molecules in heterogeneous media affect the media's dielectric response and hence the interaction between the charges is unknown since it depends on the media and on the geometrical properties of the interfaces. To determine the properties of heterogeneous systems including crucial effects neglected in classical mean field models such as the hard core of the ions, the dielectric mismatch and interfaces with arbitrary shapes. The effect of hard core interactions accounts properly for short range interactions and the effect of local dielectric heterogeneities in the presence of ions and/or charged molecules for long-range interactions are both analyzed via an energy variational principle that enables to update charges and the medium's response in the same simulation time step. In particular, we compute the ionic structure in a model system of electrolyte confined by two planar dielectric

  15. Radius of lunar core estimated by GRAIL results

    NASA Astrophysics Data System (ADS)

    Matsumoto, K.; Yamada, R.; Kikuchi, F.; Iwata, T.; Hanada, H.; Ishihara, Y.; Kamata, S.; Sasaki, S.

    2013-12-01

    Internal structure and composition of the Moon provide important clue and constraints on theories for how the Moon formed and evolved. The Apollo seismic network has contributed to the internal structure modeling. Efforts have been made to detect the lunar core from the noisy Apollo data (e.g., [1], [2]), but there is scant information about the structure below the deepest moonquakes at about 1000 km depth. On the other hand, there have been geodetic studies to infer the deep structure of the Moon. For example, LLR (Lunar Laser Ranging) data analyses detected a displacement of the lunar pole of rotation, indicating that dissipation is acting on the rotation arising from a fluid core [3]. Bayesian inversion using geodetic data (such as mass, moments of inertia, tidal Love numbers k2 and h2, and quality factor Q) also suggests a fluid core and partial melt in the lower mantle region [4]. Recent analyses of GRAIL data have achieved the improved k2 accuracy; JPL solution is 0.02405 × 0.00018 [5], and GSFC solution is 0.02427 × 0.00026 [6]. The two solutions are consistent with each other within their error bounds, and the accuracy of k2 is now about 1 %. Such an accurately-determined Love number will contribute to constrain the structure of the lunar deep interior, such as the radius of the possible liquid core. We used geodetic data of the mass, the mean moment of inertia, the Love numbers h2 and k2 to infer the size of liquid core. It is difficult to tightly constrain the internal structure from the geodetic data only because there are trade-offs among the structures of crust, mantle, and core. In our preliminary analysis we used a 5-layer model and the mantle structure was constrained by VPREMOON [2] with 5 % error for density and 10 % error for shear and bulk moduli being assumed. An inversion using Markov chain Monte Carlo method indicates that the core radius is 480 × 50 km, but the density values were sampled around the assumed lower limit of 3600 kg/m3. When

  16. [Py-Desmanet pinning in distal radius fractures].

    PubMed

    Alexa, O; Popia, I

    2009-01-01

    Internal fixation by pinning is one of the most used methods of surgical treatment in fractures of the distal extremity of the radius. As in stable fractures a styloid pinning is satisfactory, in unstable fractures however we must resort to different patterns of pin insertion, in order to effectively prevent the secondary displacement of the fractured fragments. The elastic pinning described by Py and Desmanet is one of the possibilities of inserting the pins. The principle of this method is to use the bending-induced tension in the pins to counteract the postero-lateral displacing forces. The authors have treated by this technique five patients with distal radius fractures (3 women and 2 men) about 56 years of average age, all with good-quality bone, all with Colles' fracture pattern (2-4 cm above the radio-carpal articulation, no articular involvement, posterior displacement of the distal fragment). The reduction of the fractures was achieved by closed manipulation and controlled intraoperatively with the C-arm. We preferred to reduce the fractures before inserting the pins, although this is not compulsory, according to the authors of the technique. The approach was minimally-invasive, through two 1-cm long incisions. The pins, previously blunted and curved along the last centimeters, were introduced using a "T"-shaped handle. The potential complications, consisting of injuries of the many elements which cross the region, were avoided by sufficiently long incisions and identification and retraction of these elements (tendons, nervous branches) in order not to penetrate them with the pins. The aftertreatment consisted of immediate mobilization of the wrist in one patient, 21-day splinting in other two and 30-day splinting in the last two, depending on the intraoperative assessment of the stability of the fixation. The pins were removed at 45 days postoperatively in all cases. There were no complications such as loss of reduction or pin migration. In all cases

  17. What Is the Largest Einstein Radius in the Universe?

    SciTech Connect

    Oguri, Masamune; Blandford, Roger D.

    2008-08-05

    The Einstein radius plays a central role in lens studies as it characterizes the strength of gravitational lensing. In particular, the distribution of Einstein radii near the upper cutoff should probe the probability distribution of the largest mass concentrations in the universe. Adopting a triaxial halo model, we compute expected distributions of large Einstein radii. To assess the cosmic variance, we generate a number of Monte-Carlo realizations of all-sky catalogues of massive clusters. We find that the expected largest Einstein radius in the universe is sensitive to parameters characterizing the cosmological model, especially {sigma}{sub s}: for a source redshift of unity, they are 42{sub -7}{sup +9}, 35{sub -6}{sup +8}, and 54{sub -7}{sup +12} arcseconds (errors denote 1{sigma} cosmic variance), assuming best-fit cosmological parameters of the Wilkinson Microwave Anisotropy Probe five-year (WMAP5), three-year (WMAP3) and one-year (WMAP1) data, respectively. These values are broadly consistent with current observations given their incompleteness. The mass of the largest lens cluster can be as small as {approx} 10{sup 15} M{sub {circle_dot}}. For the same source redshift, we expect in all-sky {approx} 35 (WMAP5), {approx} 15 (WMAP3), and {approx} 150 (WMAP1) clusters that have Einstein radii larger than 2000. For a larger source redshift of 7, the largest Einstein radii grow approximately twice as large. While the values of the largest Einstein radii are almost unaffected by the level of the primordial non-Gaussianity currently of interest, the measurement of the abundance of moderately large lens clusters should probe non-Gaussianity competitively with cosmic microwave background experiments, but only if other cosmological parameters are well-measured. These semi-analytic predictions are based on a rather simple representation of clusters, and hence calibrating them with N-body simulations will help to improve the accuracy. We also find that these 'superlens

  18. Failure of dual radius hydroxyapatite-coated acetabular cups

    PubMed Central

    D'Angelo, Fabio; Molina, Mauro; Riva, Giacomo; Zatti, Giovanni; Cherubino, Paolo

    2008-01-01

    Introduction Many kind of hydroxyapatite-coated cups were used, with favorable results in short term studies; it was supposed that its use could improve osteointegration of the cup, enhancing thus stability and survivorship. The purpose of this study is to analyze the long term behavior of the hemispheric HA coated, Dual Radius Osteonics cup and to discuss the way of failure through the exam of the revised components and of both periacetabular and osteolysis tissue. Materials and Methods Between 1994 and 1997, at the Department of Orthopedic Sciences of the Insubria University, using the posterolateral approach, were implanted 276 Dual Radius Osteonics® in 256 patients, with mean age of 63 years. Results At a mean follow-up of 10 years (range 8–12 years), 183 cups in 165 patients, were available for clinical and radiographical evaluation. 22 Cups among the 183 were revised (11%). The cause of revision was aseptic loosening in 17 cases, septic loosening in one case, periprosthetic fracture in another case, osteolysis and polyethylene wear in two cases and, finally, recurrent dislocations in the last one. In the remaining patients, mean HHS increased from a preoperative value of 50,15 to a postoperative value of 92,69. The mean polyethylene wear was 1,25 mm (min. 0,08, max. 3,9 mm), with a mean annual wear of 0,17 mm. The mean acetabular migration on the two axis was 1,6 mm and 1,8 mm. Peri-acetabular osteolysis were recorded in 89% of the implants (163 cases). The cumulative survivorship (revision as endpoint) at the time was 88,9%. Conclusion Our study confirms the bad behavior of this type of cup probably related to the design, to the method of HA fixation. The observations carried out on the revised cup confirm these hypotheses but did not clarify if the third body wear could be a further problem. Another interesting aspect is the high incidence of osteolysis, which are often asymptomatic becoming a problem for the surgeon as the patient refuses the

  19. The Relation Between Radius, Mass, and Incident Flux of Exoplanets

    NASA Astrophysics Data System (ADS)

    Weiss, Lauren M.; Marcy, G. W.; Rowe, J.; Isaacson, H. T.; Howard, A.; Fortney, J. J.; Miller, N.; Demory, B.; Fischer, D.; Adams, E. A.; Dupree, A. K.; Howell, S. B.; Horch, E.; Everett, M. E.; Seager, S.; Fabrycky, D. C.

    2013-01-01

    We measure the mass of a modestly irradiated giant or "warm Jupiter," KOI-94d, in order to calculate its density. We wish to determine whether this planet, which is in a 22 day orbit and receives 107 times as much incident flux as the Earth, is bloated like "hot Jupiters" or as dense as our own Jupiter. In addition to its warm Jupiter, KOI-94 hosts at least 3 smaller planets, all of which were detected through transits by the Kepler Mission. This presents the opportunity to characterize a multi-planet system and to test dynamic stability and formation theory through observations of the masses and orbital elements of these planets. With 26 radial velocity measurements of KOI-94 from the W. M. Keck Observatory/HIRES, we measure the mass of the giant planet and upper limits to the masses of the three smaller planets. Transit timing variations will allow us to hone the mass measurements of the three smaller planets. Using the KOI-94 system and all other planets with published values for both mass and radius, we establish two fundamental planes for exoplanets that relate their mass, incident flux, and radius from a few Earth masses up to ten Jupiter masses: log(Rp/RE) = 0.007 + 0.53 log(M/ME) - 0.001 log(F/[erg/s/cm^2]) for Mp < 150ME; log(Rp/RE) = 0.67 - 0.036 log(M/ME) + 0.06 log(F/[erg/s/cm^2]) for Mp > 150ME. We also solve these planes in density-mass-flux space: log(ρp/[g/cm^3]) = 0.69 - 0.57 log(M/ME) + 0.02 log(F/[erg/s/cm^2]) for Mp < 150ME; log(ρp/[g/cm^3]) = -1.23 + 1.10 log(M/ME) - 0.18 log(F/[erg/s/cm^2]) for Mp > 150ME.

  20. Failure of dual radius hydroxyapatite-coated acetabular cups.

    PubMed

    D'Angelo, Fabio; Molina, Mauro; Riva, Giacomo; Zatti, Giovanni; Cherubino, Paolo

    2008-08-07

    Many kind of hydroxyapatite-coated cups were used, with favorable results in short term studies; it was supposed that its use could improve osteointegration of the cup, enhancing thus stability and survivorship. The purpose of this study is to analyze the long term behavior of the hemispheric HA coated, Dual Radius Osteonics cup and to discuss the way of failure through the exam of the revised components and of both periacetabular and osteolysis tissue. Between 1994 and 1997, at the Department of Orthopedic Sciences of the Insubria University, using the posterolateral approach, were implanted 276 Dual Radius Osteonics in 256 patients, with mean age of 63 years. At a mean follow-up of 10 years (range 8-12 years), 183 cups in 165 patients, were available for clinical and radiographical evaluation. 22 Cups among the 183 were revised (11%). The cause of revision was aseptic loosening in 17 cases, septic loosening in one case, periprosthetic fracture in another case, osteolysis and polyethylene wear in two cases and, finally, recurrent dislocations in the last one. In the remaining patients, mean HHS increased from a preoperative value of 50.15 to a postoperative value of 92.69. The mean polyethylene wear was 1.25 mm (min. 0.08, max 3.9 mm), with a mean annual wear of 0.17 mm. The mean acetabular migration on the two axis was 1.6 mm and 1.8 mm. Peri-acetabular osteolysis were recorded in 89% of the implants (163 cases). The cumulative survivorship (revision as endpoint) at the time was 88,9%. Our study confirms the bad behavior of this type of cup probably related to the design, to the method of HA fixation. The observations carried out on the revised cup confirm these hypotheses but did not clarify if the third body wear could be a further problem. Another interesting aspect is the high incidence of osteolysis, which are often asymptomatic becoming a problem for the surgeon as the patient refuses the possibility of a revision.

  1. Synthesis and properties of polymerized ionic liquids

    DOE PAGES

    Eftekhari, Ali; Saito, Tomonori

    2017-03-14

    Polymerization of ionic liquids results in the formation of ionic polymers, which are called poly (ionic liquid)s or polymerized ionic liquids (PIL). This is a brand new form of ionicity in polymer chains with a broad range of applications, though ionic polymers have a long history with the sub-families of polyelectrolytes and ionomers. Although mobility of ions in ionic liquids has named them as the promising candidates for various applications, their applicability is limited in many practical systems because of not having the advantages of neither liquids nor solids, suffering from both leakage issue and high viscosity. PILs perfectly fitmore » with the practical requirements while having almost all features of ionic liquids. This review summarizes some potential applications of PILs. The architecture of PILs can be easily re-designed by both the polymer backbone and outer ion. Not only by post-polymerization but also by in situ ion exchange, the chemical and mechanical properties of PILs can be tuned. Lastly, owing to the high chemical activity and flexible architecture, PILs are the promising candidates for sensors and actuators, electroactive binders, solid and gel electrolytes, non-blocking matrix of nanocomposites, etc.« less

  2. An Alternative to the Ionic Model

    ERIC Educational Resources Information Center

    Sanderson, R. T.

    1975-01-01

    Describes the "coordinated polymeric model," which yields more accurate energy calculations than the "ionic model" for compounds which exhibit considerable covalency. The dichotomy between ionic and covalent bonding is thus largely broken down for solids which are nonmolecular in the crystalline state. (MLH)

  3. Hierarchical cooperative binary ionic porphyrin nanocomposites.

    PubMed

    Tian, Yongming; Busani, Tito; Uyeda, Gregory H; Martin, Kathleen E; van Swol, Frank; Medforth, Craig J; Montaño, Gabriel A; Shelnutt, John A

    2012-05-18

    Cooperative binary ionic (CBI) solids comprise a versatile new class of opto-electronic and catalytic materials consisting of ionically self-assembled pairs of organic anions and cations. Herein, we report CBI nanocomposites formed by growing nanoparticles of one type of porphyrin CBI solid onto a second porphyrin CBI substructure with complementary functionality.

  4. Chemical and Electrochemical Studies in Ionic Liquids

    DTIC Science & Technology

    1990-01-12

    Electrochemistry and Witchcraft ", Gordon Research Conference on Electrochemistry", Santa Barbara, CA, January, 1985. OR. A. Osteryoung, ’An Introduction to...Temperature Chloroaluminate Ionic Liquids: Chemistry, Electrochemistry and Witchcraft ", Chemistry Department Colloquium, University of Alabama...Tuscaloosa, Alabama, December 1, 1988. OR. A. Osteryoung, "Ambient Temperature Chloroaluminate Ionic Liquids: Chemistry, Electrochemistry and Witchcraft

  5. Ionic liquid-in-oil microemulsions.

    PubMed

    Eastoe, Julian; Gold, Sarah; Rogers, Sarah E; Paul, Alison; Welton, Tom; Heenan, Richard K; Grillo, Isabelle

    2005-05-25

    Phase stability and small-angle neutron scattering (SANS) data show that surfactant-stabilized nanodomains of a typical ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4]) may be dispersed by the nonionic surfactant Triton-X100 in cyclohexane. Analyses of these SANS data are consistent with the formation of ionic liquid-in-oil microemulsion droplets.

  6. Triazolium-based Energetic Ionic Liquids

    DTIC Science & Technology

    2005-03-01

    for public release; distribution unlimited. 18 References 1. Ionic Liquids, Industrial Applications to Green Chemistry ACS Symposium Series 818...Chem. Soc. 126, 11788-11789(2004). 11. Wilkes, J. S. in Ionic Liquids, Industrial Applications to Green Chemistry , ACS Symposium Series 818, R

  7. Engineered microorganisms having resistance to ionic liquids

    SciTech Connect

    Ruegg, Thomas Lawrence; Thelen, Michael P.

    2016-03-22

    The present invention provides for a method of genetically modifying microorganisms to enhance resistance to ionic liquids, host cells genetically modified in accordance with the methods, and methods of using the host cells in a reaction comprising biomass that has been pretreated with ionic liquids.

  8. Dielectric study on mixtures of ionic liquids.

    PubMed

    Thoms, E; Sippel, P; Reuter, D; Weiß, M; Loidl, A; Krohns, S

    2017-08-07

    Ionic liquids are promising candidates for electrolytes in energy-storage systems. We demonstrate that mixing two ionic liquids allows to precisely tune their physical properties, like the dc conductivity. Moreover, these mixtures enable the gradual modification of the fragility parameter, which is believed to be a measure of the complexity of the energy landscape in supercooled liquids. The physical origin of this index is still under debate; therefore, mixing ionic liquids can provide further insights. From the chemical point of view, tuning ionic liquids via mixing is an easy and thus an economic way. For this study, we performed detailed investigations by broadband dielectric spectroscopy and differential scanning calorimetry on two mixing series of ionic liquids. One series combines an imidazole based with a pyridine based ionic liquid and the other two different anions in an imidazole based ionic liquid. The analysis of the glass-transition temperatures and the thorough evaluations of the measured dielectric permittivity and conductivity spectra reveal that the dynamics in mixtures of ionic liquids are well defined by the fractions of their parent compounds.

  9. An Alternative to the Ionic Model

    ERIC Educational Resources Information Center

    Sanderson, R. T.

    1975-01-01

    Describes the "coordinated polymeric model," which yields more accurate energy calculations than the "ionic model" for compounds which exhibit considerable covalency. The dichotomy between ionic and covalent bonding is thus largely broken down for solids which are nonmolecular in the crystalline state. (MLH)

  10. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe

    SciTech Connect

    Nakashima, Kenichi; Stoller, Roger E.; Xu, Haixuan

    2015-01-01

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in neutron irradiated nuclear materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1:0a₀ to 3:3a₀ have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomic level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a₀ by taking the average of the recombination distances from 80 simulation cases. This value agrees well with the experimental estimate. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster.

  11. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe

    DOE PAGES

    Nakashima, Kenichi; Stoller, Roger E.; Xu, Haixuan

    2015-01-01

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in neutron irradiated nuclear materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1:0a₀ to 3:3a₀ have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomicmore » level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a₀ by taking the average of the recombination distances from 80 simulation cases. This value agrees well with the experimental estimate. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster.« less

  12. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe.

    PubMed

    Nakashima, Kenichi; Stoller, Roger E; Xu, Haixuan

    2015-08-26

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in irradiated materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1.0a0 to 3.3a0 have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomic level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a0 by taking the average of the recombination distances from 80 simulation cases. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster.

  13. Mass-radius relation of strongly magnetized white dwarfs

    NASA Astrophysics Data System (ADS)

    Bera, Prasanta; Bhattacharya, Dipankar

    2016-07-01

    We study the strongly magnetized white dwarf configurations in a self-consistent manner as a progenitor of the over-luminous type-Ia supernovae. We compute static equilibria of white dwarf stars containing a strong magnetic field and present the modification of white dwarf mass-radius relation caused by the magnetic field. From a static equilibrium study, we find that a maximum white dwarf mass of about 1.9 M_{⊙} may be supported if the interior poloidal field is as strong as approximately 10^{10} T. On the other hand, if the field is purely toroidal the maximum mass can be more than 5 M_⊙. All these modifications are mainly from the presence of Lorenz force. The effects of i) modification of equation of state due to Landau quantization ii) electrostatic interaction due to ions, ii) general relativistic calculation on the stellar structure and, iii) field geometry are also considered. These strongly magnetised configurations are sensitive to magnetic instabilities where the perturbations grow at the corresponding Alfven time scales.

  14. AO Distal Radius Fracture Classification: Global Perspective on Observer Agreement.

    PubMed

    Jayakumar, Prakash; Teunis, Teun; Giménez, Beatriz Bravo; Verstreken, Frederik; Di Mascio, Livio; Jupiter, Jesse B

    2017-02-01

    Background The primary objective of this study was to test interobserver reliability when classifying fractures by consensus by AO types and groups among a large international group of surgeons. Secondarily, we assessed the difference in inter- and intraobserver agreement of the AO classification in relation to geographical location, level of training, and subspecialty. Methods A randomized set of radiographic and computed tomographic images from a consecutive series of 96 distal radius fractures (DRFs), treated between October 2010 and April 2013, was classified using an electronic web-based portal by an invited group of participants on two occasions. Results Interobserver reliability was substantial when classifying AO type A fractures but fair and moderate for type B and C fractures, respectively. No difference was observed by location, except for an apparent difference between participants from India and Australia classifying type B fractures. No statistically significant associations were observed comparing interobserver agreement by level of training and no differences were shown comparing subspecialties. Intra-rater reproducibility was "substantial" for fracture types and "fair" for fracture groups with no difference accounting for location, training level, or specialty. Conclusion Improved definition of reliability and reproducibility of this classification may be achieved using large international groups of raters, empowering decision making on which system to utilize. Level of Evidence Level III.

  15. Optimum Cavity Radius Within a Bottle-Shaped Thermoacoustic Engine

    NASA Astrophysics Data System (ADS)

    Bridge, Justin; Andersen, Bonnie

    2009-10-01

    Heat energy can be used to generate acoustic energy due to thermoacoustic interactions. These engines can be used to create sound waves without any moving parts, like pistons, and could be used in space to convert solar energy into electricity. This research focused on the optimization of the geometry of bottle-shaped resonators used for thermoacoustic prime movers. These resonators have the advantage of non-harmonic overtones compared with half-wave resonators. The resonators for this research were constructed of concentric cylinders consisting of a neck piece and a cavity. The dimensions were approximately 5 cm with an ID of 2 cm for the neck and 10 cm long with IDs varying from about 2 cm to 12 cm for the cavity, producing operating frequencies ranging from approximately 1.2 to 1.5 kHz, following a theoretical model. Twelve different cavity radii were tested. The optimal cavity radius of 2.06 cm had an onset time that was 27 s faster and an onset temperature difference that was lower by 12 C than the smallest cavity (a half-wave resonator). Future research will explore the quality factor and optimum stack to surface area ratio of the engines.

  16. MASS-RADIUS RELATIONSHIPS FOR VERY LOW MASS GASEOUS PLANETS

    SciTech Connect

    Batygin, Konstantin; Stevenson, David J.

    2013-05-20

    Recently, the Kepler spacecraft has detected a sizable aggregate of objects, characterized by giant-planet-like radii and modest levels of stellar irradiation. With the exception of a handful of objects, the physical nature, and specifically the average densities, of these bodies remain unknown. Here, we propose that the detected giant planet radii may partially belong to planets somewhat less massive than Uranus and Neptune. Accordingly, in this work, we seek to identify a physically sound upper limit to planetary radii at low masses and moderate equilibrium temperatures. As a guiding example, we analyze the interior structure of the Neptune-mass planet Kepler-30d and show that it is acutely deficient in heavy elements, especially compared with its solar system counterparts. Subsequently, we perform numerical simulations of planetary thermal evolution and in agreement with previous studies, show that generally, 10-20 M{sub Circled-Plus }, multi-billion year old planets, composed of high density cores and extended H/He envelopes can have radii that firmly reside in the giant planet range. We subject our results to stability criteria based on extreme ultraviolet radiation, as well as Roche-lobe overflow driven mass-loss and construct mass-radius relationships for the considered objects. We conclude by discussing observational avenues that may be used to confirm or repudiate the existence of putative low mass, gas-dominated planets.

  17. Placing molecules with Bohr radius resolution using DNA origami

    NASA Astrophysics Data System (ADS)

    Funke, Jonas J.; Dietz, Hendrik

    2016-01-01

    Molecular self-assembly with nucleic acids can be used to fabricate discrete objects with defined sizes and arbitrary shapes. It relies on building blocks that are commensurate to those of biological macromolecular machines and should therefore be capable of delivering the atomic-scale placement accuracy known today only from natural and designed proteins. However, research in the field has predominantly focused on producing increasingly large and complex, but more coarsely defined, objects and placing them in an orderly manner on solid substrates. So far, few objects afford a design accuracy better than 5 nm, and the subnanometre scale has been reached only within the unit cells of designed DNA crystals. Here, we report a molecular positioning device made from a hinged DNA origami object in which the angle between the two structural units can be controlled with adjuster helices. To test the positioning capabilities of the device, we used photophysical and crosslinking assays that report the coordinate of interest directly with atomic resolution. Using this combination of placement and analysis, we rationally adjusted the average distance between fluorescent molecules and reactive groups from 1.5 to 9 nm in 123 discrete displacement steps. The smallest displacement step possible was 0.04 nm, which is slightly less than the Bohr radius. The fluctuation amplitudes in the distance coordinate were also small (±0.5 nm), and within a factor of two to three of the amplitudes found in protein structures.

  18. Massive radius-dependent flow slippage in carbon nanotubes.

    PubMed

    Secchi, Eleonora; Marbach, Sophie; Niguès, Antoine; Stein, Derek; Siria, Alessandro; Bocquet, Lydéric

    2016-09-08

    Measurements and simulations have found that water moves through carbon nanotubes at exceptionally high rates owing to nearly frictionless interfaces. These observations have stimulated interest in nanotube-based membranes for applications including desalination, nano-filtration and energy harvesting, yet the exact mechanisms of water transport inside the nanotubes and at the water-carbon interface continue to be debated because existing theories do not provide a satisfactory explanation for the limited number of experimental results available so far. This lack of experimental results arises because, even though controlled and systematic studies have explored transport through individual nanotubes, none has met the considerable technical challenge of unambiguously measuring the permeability of a single nanotube. Here we show that the pressure-driven flow rate through individual nanotubes can be determined with unprecedented sensitivity and without dyes from the hydrodynamics of water jets as they emerge from single nanotubes into a surrounding fluid. Our measurements reveal unexpectedly large and radius-dependent surface slippage in carbon nanotubes, and no slippage in boron nitride nanotubes that are crystallographically similar to carbon nanotubes, but electronically different. This pronounced contrast between the two systems must originate from subtle differences in the atomic-scale details of their solid-liquid interfaces, illustrating that nanofluidics is the frontier at which the continuum picture of fluid mechanics meets the atomic nature of matter.

  19. Mass-Radius Relation for Rocky Planets Based on PREM

    NASA Astrophysics Data System (ADS)

    Zeng, Li; Sasselov, Dimitar D.; Jacobsen, Stein B.

    2016-03-01

    Several small dense exoplanets are now known, inviting comparisons to Earth and Venus. Such comparisons require translating their masses and sizes to composition models of evolved multi-layer interior planets. Such theoretical models rely on our understanding of the Earth’s interior, as well as independently derived equations of state, but so far have not involved direct extrapolations from Earth’s seismic model: the Preliminary Reference Earth Model (PREM). To facilitate more detailed compositional comparisons between small exoplanets and the Earth, we derive here a semi-empirical mass-radius relation for two-layer rocky planets based on PREM, \\frac{R}{{R}\\oplus }=(1.07-0.21\\cdot {CMF})\\cdot {≤ft(\\frac{M}{{M}\\oplus }\\right)}1/3.7, where CMF stands for core mass fraction. It is applicable to 1 ˜ 8 M⊕ and a CMF of 0.0 ˜ 0.4. Applying this formula to Earth and Venus and several known small exoplanets with radii and masses measured to better than ˜30% precision gives a CMF fit of 0.26 ± 0.07.

  20. PHOTOSPHERIC RADIUS EXPANSION IN SUPERBURST PRECURSORS FROM NEUTRON STARS

    SciTech Connect

    Keek, L.

    2012-09-10

    Thermonuclear runaway burning of carbon is in rare cases observed from accreting neutron stars as day-long X-ray flares called superbursts. In the few cases where the onset is observed, superbursts exhibit a short precursor burst at the start. In each instance, however, the data are of insufficient quality for spectral analysis of the precursor. Using data from the propane anti-coincidence detector of the Proportional Counter Array instrument on the Rossi X-ray Timing Explorer, we perform the first detailed time-resolved spectroscopy of precursors. For a superburst from 4U 1820-30 we demonstrate the presence of photospheric radius expansion. We find the precursor to be 1.4-2 times more energetic than other short bursts from this source, indicating that the burning of accreted helium is insufficient to explain the full precursor. Shock heating would be able to account for the shortfall in energy. We argue that this precursor is a strong indication that the superburst starts as a detonation, and that a shock induces the precursor. Furthermore, we employ our technique to study the superexpansion phase of the same superburst in greater detail.

  1. Complex radius shaft malunion: osteotomy with computer-assisted planning.

    PubMed

    Schweizer, Andreas; Fürnstahl, Philipp; Harders, Matthias; Székely, Gábor; Nagy, Ladislav

    2010-06-01

    We report about two cases with a combined axial and angular malunion of the radius shaft with functional loss of pro-supination. For the preoperative planning, a computer simulation was developed that allows the quantification of the malunion by comparing the 3-d surface model of the impaired bone with the contralateral anatomy. The proximal parts of the left and right radii are superimposed, while the different positions of the distal parts are used to quantify the malunion. This task is performed fully automatically which reduces the overall planning time. The osteotomies were performed according to the results of the computer-aided planning. The first case showed 1 year postoperatively an increase of pronation from 40° to 70° at expense of supination from 95° to 90°. The patient was practically pain-free and reported functional improvement. The second case showed 6 months postoperatively an improvement of supination from 15° to 40° and of pronation from 50° to 60°. The computer-assisted operation planning facilitated the quantification of combined axial and angular malunions which were difficult to detect on plain radiographs.

  2. Determination of Optimal Blank Shape by Radius Vector Method

    NASA Astrophysics Data System (ADS)

    Shim, Hyun Bo; Park, Jong Kyu; Kim, Yang Soo

    2004-06-01

    A new method of optimal blank shape design for stampings of arbitrary shapes has been proposed. Similar to the sensitivity method, a past work of the present author, the basic nature of this method is iterative modification of an undeformed blank shape by adjusting the nodal positions at the boundary of the blank, until the final shape satisfies a target shape. The main difference from the sensitivity method is that both shape error measure and blank shape modification is done along the normal to a boundary direction in the current method instead of nodal moving direction as in the sensitivity method. Even though the sensitivity method has been proven to be excellent through experiment, huge computational effort is still a problem since the method requires a couple of deformation process analyses per each design stage. Differently from the sensitivity method, the present radius vector method requires only a single deformation analysis per each design step and it can handle an extraordinary motion due to a rigid-body rotation during forming. Drawings of L-shaped cup and wheel housing have been chosen as the examples to verify the present method. In every cases the optimal blank shapes have been obtained after a few times of modification. Through the investigation, the present method, which incorporates normal to boundary is found to be an excellent, or better than the sensitivity method, which incorporates moving direction, for the optimal blank design.

  3. Thrombocytopenia-absent radius syndrome: a clinical genetic study

    PubMed Central

    Greenhalgh, K; Howell, R; Bottani, A; Ancliff, P; Brunner, H; Verschuuren-Bemel..., C; Vernon, E; Brown, K; Newbury-Ecob, R

    2002-01-01

    The thrombocytopenia-absent radius (TAR) syndrome is a congenital malformation syndrome characterised by bilateral absence of the radii and a thrombocytopenia. The lower limbs, gastrointestinal, cardiovascular, and other systems may also be involved. Shaw and Oliver in 1959 were the first to describe this condition, but it was Hall et al in 1969 who reported the first major series of patients. Since then most reports have been based on single or small numbers of cases. We report the results of a clinical study looking at the phenotype of 34 patients with TAR syndrome. All cases had a documented thrombocytopenia and bilateral radial aplasia, 47% had lower limb anomalies, 47% cow's milk intolerance, 23% renal anomalies, and 15% cardiac anomalies. Congenital anomalies not previously described in association with TAR syndrome included facial capillary haemangiomata, intracranial vascular malformation, sensorineural hearing loss, and scoliosis. Karyotype analysis, chromosome breakage studies including premature centromeric separation and fluorescence in situ hybridisation studies looking for a deletion of chromosome 22q11 were undertaken. Two abnormal karyotypes were identified. PMID:12471199

  4. System Estimates Radius of Curvature of a Segmented Mirror

    NASA Technical Reports Server (NTRS)

    Rakoczy, John

    2008-01-01

    A system that estimates the global radius of curvature (GRoC) of a segmented telescope mirror has been developed for use as one of the subsystems of a larger system that exerts precise control over the displacements of the mirror segments. This GRoC-estimating system, when integrated into the overall control system along with a mirror-segment- actuation subsystem and edge sensors (sensors that measure displacements at selected points on the edges of the segments), makes it possible to control the GROC mirror-deformation mode, to which mode contemporary edge sensors are insufficiently sensitive. This system thus makes it possible to control the GRoC of the mirror with sufficient precision to obtain the best possible image quality and/or to impose a required wavefront correction on incoming or outgoing light. In its mathematical aspect, the system utilizes all the information available from the edge-sensor subsystem in a unique manner that yields estimates of all the states of the segmented mirror. The system does this by exploiting a special set of mirror boundary conditions and mirror influence functions in such a way as to sense displacements in degrees of freedom that would otherwise be unobservable by means of an edge-sensor subsystem, all without need to augment the edge-sensor system with additional metrological hardware. Moreover, the accuracy of the estimates increases with the number of mirror segments.

  5. Closing capacity of segmental radius defects in rabbits.

    PubMed

    Bodde, Esther W H; Spauwen, Paul H M; Mikos, Antonios G; Jansen, John A

    2008-04-01

    In the research of synthetic bone graft substitutes, the relevance for bone regeneration can be confirmed in a critical-sized model. In this study the rabbit radial defect was investigated as an ingenious model of critical size, due to its defect immobilizing intact ulna. In addition, the influence of poly(DL-lactic-co-glycolic acid) (PLGA) on bone regeneration was determined. Sixteen, 4-month-old rabbits received bilateral segmental radial defects of 15 or 20 mm. The osteotomy ends were marked with small titanium pins. Half of the group received injected PLGA microparticle/carboxymethylcellulose implants. Implantation time was 12 weeks. Evaluation consisted of radiographs after surgery and sacrifice, microcomputed tomography and histology. The radiographs revealed that the created defects were significantly smaller after sacrifice. Further a number of radii showed fibrocartilaginous interposition. Both findings indicated instability of the created defect. All evaluation techniques revealed that 15 and 20 mm were not of critical size, as most defects were more or less regenerated. PLGA microparticles did not influence bone regeneration significantly. In conclusion, 15- and 20-mm radius defects in 4-month-old rabbits were not a suitable model for bone regeneration as these defects were neither critical size nor stable. PLGA-microparticle degradation did not influence bone regeneration.

  6. Photogrammetric analysis of the articular surface of the distal radius.

    PubMed

    Ege, A; Seker, D Z; Tuncay, I; Duran, Z

    2004-01-01

    Three-dimensional measurements made using photogrammetry have recently gained popularity with the development of real-time detection facilities and up-to-date equipment. The modelling of human bones presents a particular challenge as the measurements required are difficult to obtain, especially from uneven surfaces. In this study, the articular surfaces of 12 radius bones were evaluated using photogrammetry to obtain three-dimensional coordinates of certain points. Morphometric characteristics of the digital topography of the articular surface were analysed using three-dimensional data from more than 200 points for each specimen. The coronal plane curve, from the tip of the styloid process to the centre of the distal radioulnar articular notch, was found to be similar to the fourth degree polynomial function. A mathematical expression representing the sagittal curve passing through scapholunate border could not be found. Close-range photogrammetry is a safe and precise technique that can provide reliable, reproducible and accurate data for evaluating complex morphological surfaces.

  7. Mass-Radius Relation of Strongly Magnetized White Dwarfs

    NASA Astrophysics Data System (ADS)

    Bera, P.; Bhattacharya, D.

    2017-03-01

    We study the strongly magnetized white dwarf configurations in a self-consistent manner as a progenitor of the over-luminous type-Ia supernovae. We compute static equilibria of white dwarf stars containing a strong magnetic field and present the modification of the white dwarf mass-radius relation caused by the magnetic field. From a static equilibrium study, we find that a maximum white dwarf mass of about 1.9 M⊙ may be supported if the interior poloidal field is as strong as approximately 1010 T. On the other hand if the field is purely toroidal the maximum mass can be more than 5 M⊙. All these modifications are mainly from the presence of the Lorenz force. The effects of i) modification of the equation of state due to Landau quantization, ii) electrostatic interaction due to ions, iii) general relativistic calculation on the stellar structure and, iv) field geometry are also considered. These strongly magnetised configurations are sensitive to magnetic instabilities where the perturbations grow at the corresponding Alfven time scales.

  8. Massive radius-dependent flow slippage in carbon nanotubes

    PubMed Central

    Secchi, Eleonora; Marbach, Sophie; Niguès, Antoine; Stein, Derek; Siria, Alessandro; Bocquet, Lydéric

    2016-01-01

    Simulations and measurements have established that water moves through carbon nanotubes with exceptionally high rates due to nearly frictionless interfaces1–4. These observations have stimulated interest in nanotube-based membranes for applications that range from desalination to nano-filtration and energy harvesting5–10, yet the exact water transport mechanisms inside the nanotubes and at the water-carbon interface continue to be controversially discussed11,12 because existing theories fail to provide a satisfying explanation for the limited number of experimental results available to date13. This is because even though controlled and systematic studies have explored transport through individual nanotubes8,9,14–7, none has met the considerable technical challenge of unambiguously measuring the permeability of a single nanotube11. Here we show that the pressure-driven flow rate across individual nanotubes can be determined with unprecedented sensitivity and without dyes from the hydrodynamics of water jets as they emerge from single nanotubes into a surrounding fluid. Our measurements reveal unexpectedly large and radius-dependent surface slippage in carbon nanotubes (CNT), and no slippage in boron-nitride nanotubes (BNNT) that are crystallographically similar to CNTs but differ electronically. This pronounced contrast between the two systems must originate from subtle differences in atomic-scale details of their solid-liquid interfaces, strikingly illustrating that nanofluidics is the frontier where the continuum picture of fluid mechanics confronts the atomic nature of matter. PMID:27604947

  9. Complex Radius Shaft Malunion: Osteotomy with Computer-Assisted Planning

    PubMed Central

    Fürnstahl, Philipp; Harders, Matthias; Székely, Gábor; Nagy, Ladislav

    2009-01-01

    We report about two cases with a combined axial and angular malunion of the radius shaft with functional loss of pro-supination. For the preoperative planning, a computer simulation was developed that allows the quantification of the malunion by comparing the 3-d surface model of the impaired bone with the contralateral anatomy. The proximal parts of the left and right radii are superimposed, while the different positions of the distal parts are used to quantify the malunion. This task is performed fully automatically which reduces the overall planning time. The osteotomies were performed according to the results of the computer-aided planning. The first case showed 1 year postoperatively an increase of pronation from 40° to 70° at expense of supination from 95° to 90°. The patient was practically pain-free and reported functional improvement. The second case showed 6 months postoperatively an improvement of supination from 15° to 40° and of pronation from 50° to 60°. The computer-assisted operation planning facilitated the quantification of combined axial and angular malunions which were difficult to detect on plain radiographs. PMID:19826878

  10. Mass and Radius Constraints Using Magnetar Giant Flare Oscillations

    NASA Astrophysics Data System (ADS)

    Deibel, Alex T.; Steiner, A. W.; Brown, E. F.

    2013-04-01

    We extend the study of oscillating neutron stars to include observed magnetic field strengths. The strong magnetic field will alter the equilibrium composition of the outer neutron star crust. We construct a new neutron star crust model which predicts nuclear masses with an accuracy very close to that of the Finite Range Droplet Model. The mass model for equilibrium nuclei also includes recent developments in the nuclear physics, in particular, shell corrections and an updated neutron-drip line. We perturb our crust model to predict axial crust modes and assign them to observed giant flare quasi-periodic oscillation (QPO) frequencies from SGR 1806-20. The QPOs associated with the fundamental and harmonic crust modes can be used to constrain magnetar masses and radii. We use these modes and the phenomenological equations of state from Steiner et al. to find a magnetar crust which reproduces observations of SGR 1806-20. We find magnetar crusts which match observations for various magnetic field strengths and values of entrainment of the free neutron gas in the inner crust. For a crust without a magnetic field we obtain the approximate values of M = 1.35 Msun and R = 11.85 km. For a magnetized crust with the surface dipole field of SGR 1806-20 we obtain the approximate values of M = 1.25 Msun and R = 12.41 km. If there is less entrainment of the free neutron gas the magnetar requires a larger mass and radius to reproduce observations.

  11. Biomechanical analysis of distal radius fractures using intramedullary Kirschner wires.

    PubMed

    Tsai, Wen-Chi; Lin, Shang-Chih; Hsiao, Chun-Ching; Lu, Tung-Wu; Chao, Ching-Kong; Liu, Hwa-Chang

    2009-03-01

    Colles's fracture is the most common type of distal radius fracture. Surgically, it remains a challenge to restore radial height and volar tilt in order to regain optimal wrist function. Ulson's procedure provides a dynamic effect on fixing fractured fragments and restoring joint function using two wires. However, the biomechanical influences of bone and wire remain critical issues for fracture reduction and bone union in Ulson's procedure. Based on elastic beam and foundation theory, this study formulated a closed-form mathematical model to investigate the effects of bone and wire parameters on wire deflection and bony reaction. The wire deflection and bony reaction were chosen as the indices of wrist stability and reduction within the post-operative period. The predicted results showed that greater bone strength, higher wire stiffness, and longer wire contact length provide a more stable wire-bone construct, thus facilitating fracture reduction and bone union. The wire stiffness had a much more significant effect on the construct stability compared with bone quality and contact length. In terms of entry point and insertion angle, surgical planning for the contact length was more important than bony quality for stabilizing the whole wire-bone construct.

  12. Pediatric distal radius fractures and triangular fibrocartilage complex injuries.

    PubMed

    Bae, Donald S; Waters, Peter M

    2006-02-01

    Management of distal radius fractures is guided by the pattern and location of injury, degree of deformity, and expectations of bony remodeling based on the amount of remaining skeletal growth.Indications for surgical treatment include unstable or irreducible fractures, open fractures, floating elbow injuries, and neurovascular or soft-tissue compromise precluding cast immobilization. Patients and families should be counseled regarding the potential for post-traumatic distal radial growth arrest following physeal fractures. In these cases, epiphysiodeses, ulnar shortening osteotomies, or corrective radial osteotomies may be performed, depending on the pattern of arrest,degree of deformity, and remaining skeletal growth.TFCC tears may be the source of ulnar-sided wrist pain in children and adolescents, though symptoms and physical examination findings maybe subtle. Patients who have persistent pain and functional limitations despite activity modification and therapy are candidates for surgical treatment. Appropriate repair of peripheral TFCC tears with correction of concomitant wrist pathology restores normal wrist anatomy, alleviates pain, and allows for return to functional activities.

  13. Massive radius-dependent flow slippage in carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Secchi, Eleonora; Marbach, Sophie; Niguès, Antoine; Stein, Derek; Siria, Alessandro; Bocquet, Lydéric

    2016-09-01

    Measurements and simulations have found that water moves through carbon nanotubes at exceptionally high rates owing to nearly frictionless interfaces. These observations have stimulated interest in nanotube-based membranes for applications including desalination, nano-filtration and energy harvesting, yet the exact mechanisms of water transport inside the nanotubes and at the water-carbon interface continue to be debated because existing theories do not provide a satisfactory explanation for the limited number of experimental results available so far. This lack of experimental results arises because, even though controlled and systematic studies have explored transport through individual nanotubes, none has met the considerable technical challenge of unambiguously measuring the permeability of a single nanotube. Here we show that the pressure-driven flow rate through individual nanotubes can be determined with unprecedented sensitivity and without dyes from the hydrodynamics of water jets as they emerge from single nanotubes into a surrounding fluid. Our measurements reveal unexpectedly large and radius-dependent surface slippage in carbon nanotubes, and no slippage in boron nitride nanotubes that are crystallographically similar to carbon nanotubes, but electronically different. This pronounced contrast between the two systems must originate from subtle differences in the atomic-scale details of their solid-liquid interfaces, illustrating that nanofluidics is the frontier at which the continuum picture of fluid mechanics meets the atomic nature of matter.

  14. The mass-radius relationship of massive compact stars

    SciTech Connect

    Chowdhury, Partha Roy

    2015-02-24

    The properties of pure hadronic and hybrid compact stars are reviewed using nuclear equation of state (EoS) for β-equilibrated neutron star (NS) matter obtained using a density-dependent M3Y (DDM3Y) effective nucleon-nucleon interaction. Depending on the model, the energy density of quark matter can be lower than that of this nuclear EoS at higher densities, implying the possibility of transition to quark matter inside the core and the transition density depends on the particular quark matter model used. The recent observations of the binary millisecond pulsar J1614–2230 by P.B. Demorest et al. [1] and PSR J0348+0432 by J. Antoniadis et al. [2] suggest that the masses lie within 1.97 ± 0.04 M{sub ⊙} and 2.01 ± 0.04 M{sub ⊙}, respectively, where M{sub ⊙} is the solar mass. In conformity with recent observations, a pure nucleonic EoS determines that the maximum mass of NS rotating with frequency ν∼ 667 Hz below r-mode instability is ∼ 1.95 M{sub ⊙} with radius ∼ 10 km. Compact stars with quark cores rotating with same frequency have the maximum mass of ∼ 1.72 M{sub ⊙} turns out to be lower than the observed masses.

  15. Collective Behavior of Interacting Particles: Radius-Dependent Phase Transition

    NASA Astrophysics Data System (ADS)

    Tarras, I.; Moussa, N.; Mazroui, M.; Boughaleb, Y.; Hajjaji, A.

    2013-02-01

    The aim of this paper is to study and discuss the effect of three zones (repulsion zone, orientation zone and attraction zone) on the phase transition in 2D-collective moving particles. Our main motivation is to better understand the complex behavior of non-equilibrium multi-agent system by extending the earlier and original model proposed by Viscek et al. [T. Viscek et al., Phys. Rev. Lett.75 (1995) 1226] for one zone. The analysis is performed over different situations by using a numerical simulation method. It is found that the radius R2 of orientation zone plays an important role in the system. In effect, by varying the parameter R2 a phase transition can be achieved from disordered moving of individuals to a group to highly aligned collective motion. The results also show that, the critical value of R2 at which the transition emerges depends strongly on the size of the repulsion zone but not on the size of attraction one.

  16. Volar morphology of the distal radius in axial planes: a quantitative analysis.

    PubMed

    Oura, Keiichiro; Oka, Kunihiro; Kawanishi, Yohei; Sugamoto, Kazuomi; Yoshikawa, Hideki; Murase, Tsuyoshi

    2015-04-01

    To investigate the cause of rupture of the flexor pollicis longus (FPL) after volar plate fixation of distal radius fractures, previous studies have examined the shape of the distal radius in the sagittal plane or in the lateral view. However, there are no reports on the anatomical shape of the volar surface concavity of the distal radius in the axial plane. We hypothesized that this concavity might contribute to the mismatch between the plate and the surface of the radius. To test this hypothesis, we constructed three-dimensional models of the radius and FPL based on computed tomography scans of 70 normal forearms. We analyzed axial cross-sectional views with 2 mm intervals. In all cases, the volar surface of the distal radius was concave in the axial plane. The concavity depth was maximum at 6 mm proximal to the palmar edge of the lunate fossa and progressively decreased toward the proximal radius. FPL was closest to the radius at 2 mm proximal to the palmar edge of the lunate fossa. The volar surface of the distal radius was externally rotated from proximal to distal. These results may help to develop new implants which fit better to the radius and decrease tendon irritation.

  17. Lithium-Air and ionic Liquids

    SciTech Connect

    Kellar, Michael

    2015-09-01

    The final portion of this project was accomplished at Sandia National Labs, Livermore, with the overall goal being to optimize lithium-air cells with an ionic liquid electrolyte. Both of these are potential future routes for lithium-ion technology. Lithiumair presents the advantage of higher gravimetric energy density, and ionic liquids present the advantage of greater hydrophobicity and much lower volatility, along with a larger window of electrochemical stability. Ionic liquids however have several drawbacks for the battery industry. Currently they are not as cost effective as many organic solvents. Additionally, because of the added viscosity of ionic interactions compared to the typical dipole interactions of a solvent, the ionic conductivity is lower than for common organic solvents.

  18. Depolarization of water in protic ionic liquids.

    PubMed

    Zahn, Stefan; Wendler, Katharina; Delle Site, Luigi; Kirchner, Barbara

    2011-09-07

    A mixture of the protic ionic liquid mono-methylammonium nitrate with 1.6 wt% water was investigated from Car-Parrinello molecular dynamics simulations. In contrast to imidazolium-based ionic liquids, the cation possesses strong directional hydrogen bonds to water and all hydrogen bonds in the mixture have a comparable strength. This results in a good incorporation of water into the hydrogen bond network of mono-methylammonium nitrate and a tetrahedral hydrogen bond coordination of water. Hence, one might expect a larger dipole moment of water in the investigated mixture compared to neat water due to the good hydrogen bond network incorporation and the charged vicinity of water in the protic ionic liquid. However, the opposite is observed pointing to strong electrostatic screening in protic ionic liquids. Additionally, the influence of water on the properties of the protic ionic liquid is discussed.

  19. Nonlocal optical nonlinearity of ionic liquids

    NASA Astrophysics Data System (ADS)

    Souza, R. F.; Alencar, M. A. R. C.; Meneghetti, M. R.; Dupont, J.; Hickmann, J. M.

    2008-04-01

    The nonlinear optical properties of two ionic liquids, 1-n-butyl-3-methylimidazolium tetrafluoroborate ([BMI]BF4) and 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMI]PF6), have been investigated using the Z-scan technique. These compounds are liquid at room temperature and present a strong ionic nature. Nonlinear refraction and absorption, and thermo-optical measurements for both ionic liquids were performed using two different laser wavelengths, 514 nm and 810 nm, in the continuous wave and femtosecond regimes, respectively. It was observed that those specimens have large negative nonlinear refractive indexes and thermo-optical coefficients, but nonlinear absorption was not observed. Different dispersion relations were observed depending on the ionic liquid anion, which may be related to the distinct structures of these compounds. This result indicates that ionic liquids are suitable media for the investigation of nonlocal nonlinear phenomena.

  20. A-site ordered quadruple perovskite oxides

    NASA Astrophysics Data System (ADS)

    Youwen, Long

    2016-07-01

    The A-site ordered perovskite oxides with chemical formula display many intriguing physical properties due to the introduction of transition metals at both A‧ and B sites. Here, research on the recently discovered intermetallic charge transfer occurring between A‧-site Cu and B-site Fe ions in LaCu3Fe4O12 and its analogues is reviewed, along with work on the magnetoelectric multiferroicity observed in LaMn3Cr4O12 with cubic perovskite structure. The Cu-Fe intermetallic charge transfer leads to a first-order isostructural phase transition accompanied by drastic variations in magnetism and electrical transport properties. The LaMn3Cr4O12 is a novel spin-driven multiferroic system with strong magnetoelectric coupling effects. The compound is the first example of cubic perovskite multiferroics to be found. It opens up a new arena for studying unexpected multiferroic mechanisms. Project supported by the National Basic Research Program of China (Grant No. 2014CB921500), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB07030300), and the National Natural Science Foundation of China (Grant No. 11574378).

  1. Ionic Moduli: A New Semi-Empirical Model for the Compression of Crystalline Matierals

    NASA Astrophysics Data System (ADS)

    Hummer, D. R.

    2016-12-01

    The bulk modulus is arguably the most important elastic property governing material behavior under pressure, but we currently lack comprehensive models explaining bulk modulus in terms of simpler parameters. Lacking a theoretical framework for understanding bulk modulus at an atomic scale makes it difficult to know whether measured equations of state are realistic for actual mantle minerals. Here, a new semi-empirical model is presented which quantitatively predicts the bulk modulus of crystalline ionic compounds in terms of the compression of their constituent ions. The model assumes that ions are elastic spheres compressing independently of their environment according to a first order equation of state. Each ion has a unique "ionic modulus", defined analogously to bulk modulus, governing its reduction in size as a function of pressure. Testing against experimental compression data for 20 alkali halides reveals that the ionic modulus model correctly predicts 13 out of 20 bulk moduli within 10% error, far better than expected by chance. The resulting moduli of most alkali metal and halide ions are a linear function of the zero-pressure ionic radius, revealing that the compression of individual ions in a crystal structure follows a simple scaling law. The ionic modulus model provides a new and powerful way to predict compression behavior and pressure-induced phase transitions in a variety of materials, including minerals important to Earth's upper and lower mantle. Further development of this model could potentially lead to a priori prediction of phase diagrams in real geochemical systems, and a unified framework for modeling planetary interiors.

  2. Ionic homeostasis in brain conditioning

    PubMed Central

    Cuomo, Ornella; Vinciguerra, Antonio; Cerullo, Pierpaolo; Anzilotti, Serenella; Brancaccio, Paola; Bilo, Leonilda; Scorziello, Antonella; Molinaro, Pasquale; Di Renzo, Gianfranco; Pignataro, Giuseppe

    2015-01-01

    Most of the current focus on developing neuroprotective therapies is aimed at preventing neuronal death. However, these approaches have not been successful despite many years of clinical trials mainly because the numerous side effects observed in humans and absent in animals used at preclinical level. Recently, the research in this field aims to overcome this problem by developing strategies which induce, mimic, or boost endogenous protective responses and thus do not interfere with physiological neurotransmission. Preconditioning is a protective strategy in which a subliminal stimulus is applied before a subsequent harmful stimulus, thus inducing a state of tolerance in which the injury inflicted by the challenge is mitigated. Tolerance may be observed in ischemia, seizure, and infection. Since it requires protein synthesis, it confers delayed and temporary neuroprotection, taking hours to develop, with a pick at 1–3 days. A new promising approach for neuroprotection derives from post-conditioning, in which neuroprotection is achieved by a modified reperfusion subsequent to a prolonged ischemic episode. Many pathways have been proposed as plausible mechanisms to explain the neuroprotection offered by preconditioning and post-conditioning. Although the mechanisms through which these two endogenous protective strategies exert their effects are not yet fully understood, recent evidence highlights that the maintenance of ionic homeostasis plays a key role in propagating these neuroprotective phenomena. The present article will review the role of protein transporters and ionic channels involved in the control of ionic homeostasis in the neuroprotective effect of ischemic preconditioning and post-conditioning in adult brain, with particular regards to the Na+/Ca2+ exchangers (NCX), the plasma membrane Ca2+-ATPase (PMCA), the Na+/H+ exchange (NHE), the Na+/K+/2Cl− cotransport (NKCC) and the acid-sensing cation channels (ASIC). Ischemic stroke is the third leading

  3. A biomechanical approach to distal radius fractures for the emergency radiologist.

    PubMed

    Bunch, Paul M; Sheehan, Scott E; Dyer, George S; Sodickson, Aaron; Khurana, Bharti

    2016-04-01

    Distal radius fractures are the most common upper extremity fracture and account for approximately one sixth of all fractures treated in US emergency departments. These fractures are associated with significant morbidity and have a major economic impact. Radiographic evaluation of distal radius fractures is frequently performed in the emergency department setting, has a profound impact on initial management, and is essential to assessing the quality and relative success of the initial reduction. While the most appropriate definitive management of distal radius fractures remains controversial, overarching treatment principles reflect distal radius injury mechanisms and biomechanics. An intuitive understanding of the biomechanics of the distal radius and of common mechanisms of injury informs and improves the emergency radiologist's ability to identify key imaging findings with important management implications and to communicate the critical information that emergency physicians and orthopedic surgeons need to best manage distal radius fractures.

  4. Contact Radius and the Insulator-Metal Transition in Films Comprised of Touching Semiconductor Nanocrystals.

    PubMed

    Lanigan, Deanna; Thimsen, Elijah

    2016-07-26

    Nanocrystal assemblies are being explored for a number of optoelectronic applications such as transparent conductors, photovoltaic solar cells, and electrochromic windows. Majority carrier transport is important for these applications, yet it remains relatively poorly understood in films comprised of touching nanocrystals. Specifically, the underlying structural parameters expected to determine the transport mechanism have not been fully elucidated. In this report, we demonstrate experimentally that the contact radius, between touching heavily doped ZnO nanocrystals, controls the electron transport mechanism. Spherical nanocrystals are considered, which are connected by a circular area. The radius of this circular area is the contact radius. For nanocrystals that have local majority carrier concentration above the Mott transition, there is a critical contact radius. If the contact radius between nanocrystals is less than the critical value, then the transport mechanism is variable range hopping. If the contact radius is greater than the critical value, the films display behavior consistent with metallic electron transport.

  5. CADDIS Volume 2. Sources, Stressors and Responses: Ionic Strength - Detailed Conceptual Diagram

    EPA Pesticide Factsheets

    Introduction to the ionic strength module, when to list ionic strength as a candidate cause, ways to measure ionic strength, simple and detailed conceptual diagrams for ionic strength, ionic strength module references and literature reviews.

  6. CADDIS Volume 2. Sources, Stressors and Responses: Ionic Strength - Simple Conceptual Diagram

    EPA Pesticide Factsheets

    Introduction to the ionic strength module, when to list ionic strength as a candidate cause, ways to measure ionic strength, simple and detailed conceptual diagrams for ionic strength, ionic strength module references and literature reviews.

  7. Ab initio investigations of A-site doping on the structure and electric polarization of HoMnO3

    NASA Astrophysics Data System (ADS)

    S, Sathya Sheela; C, Kanagaraj; Natesan, Baskaran

    2015-06-01

    We have investigated the effect of A-site doping on the structure and electric polarization of orthorhombic HoMnO3 using ab initio density functional theory calculations. We find that the substitution of rare earth ions, such as Lu, Y and La in place of Ho in orthorhombic HoMnO3 modifies the local structure around Mn ions drastically, and leads to the formation of two distinct Mn sites Mn(0) and Mn(1). As a result, large variance between Mn(0)O6 and Mn(1)O6 octahedral distortions arises. This variance in the octahedral distortions drives the disparate hopping of electrons between the eg orbitals enhancing the electronic polarization with increasing rare earth ion radius. The largest polarization of 7 µC/cm2 is obtained for La doped HoMnO3. This increase in polarization has been explained on the basis of radius mismatch induced local structural effects.

  8. The strength of polyaxial locking interfaces of distal radius plates.

    PubMed

    Hoffmeier, Konrad L; Hofmann, Gunther O; Mückley, Thomas

    2009-10-01

    Currently available polyaxial locking plates represent the consequent enhancement of fixed-angle, first-generation locking plates. In contrast to fixed-angle locking plates which are sufficiently investigated, the strength of the new polyaxial locking options has not yet been evaluated biomechanically. This study investigates the mechanical strength of single polyaxial interfaces of different volar radius plates. Single screw-plate interfaces of the implants Palmar 2.7 (Königsee Implantate und Instrumente zur Osteosynthese GmbH, Allendorf, Germany), VariAx (Stryker Leibinger GmbH & Co. KG, Freiburg, Germany) und Viper (Integra LifeSciences Corporation, Plainsboro, NJ, USA) were tested by cantilever bending. The strength of 0 degrees, 10 degrees and 20 degrees screw locking angle was obtained during static and dynamic loading. The Palmar 2.7 interfaces showed greater ultimate strength and fatigue strength than the interfaces of the other implants. The strength of the VariAx interfaces was about 60% of Palmar 2.7 in both, static and dynamic loading. No dynamic testing was applied to the Viper plate because of its low ultimate strength. By static loading, an increase in screw locking angle caused a reduction of strength for the Palmar 2.7 and Viper locking interfaces. No influence was observed for the VariAx locking interfaces. During dynamic loading; angulation had no influence on the locking strength of Palmar 2.7. However, reduction of locking strength with increasing screw angulation was observed for VariAx. The strength of the polyaxial locking interfaces differs remarkably between the examined implants. Depending on the implant an increase of the screw locking angle causes a reduction of ultimate or fatigue strength, but not in all cases a significant impact was observed.

  9. VARIATION OF INNER RADIUS OF DUST TORUS IN NGC4151

    SciTech Connect

    Koshida, Shintaro; Sakata, Yu; Sugawara, Shota; Yoshii, Yuzuru; Minezaki, Takeo; Tomita, Hiroyuki; Kobayashi, Yukiyasu; Suganuma, Masahiro; Enya, Keigo; Aoki, Tsutomu; Peterson, Bruce A.

    2009-08-01

    Long-term optical and near-infrared monitoring observations for a type 1 active galactic nucleus (AGN) NGC 4151 were carried out for six years from 2001 to 2006 by using the MAGNUM telescope, and delayed response of flux variations in the K(2.2 {mu}m) band to those in the V(0.55 {mu}m) band was clearly detected. Based on cross-correlation analysis, we precisely measured a lag time {delta}t for eight separate periods and we found that {delta}t is not constant, changing between 30 and 70 d during the monitoring period. Since {delta}t is the light travel time from the central energy source out to the surrounding dust torus, this is the first convincing evidence that the inner radius of the dust torus did change in an individual AGN. In order to relate such a change of {delta}t with a change of AGN luminosity L, we present a method of taking an average of the observed V-band fluxes that corresponds to the measured value of {delta}t, and we find that the time-changing track of NGC 4151 in the {delta}t versus L diagram during the monitoring period deviates from the relation {delta}t {proportional_to} L {sup 0.5} expected from dust reverberation. This result, combined with the elapsed time from period to period for which {delta}t was measured, indicates that the timescale of dust formation is about one year, which should be taken into account as a new constraint in future studies of dust evolution in AGNs.

  10. Updated Variable-Radius Measures of Hospital Competition

    PubMed Central

    Gresenz, Carole Roan; Rogowski, Jeannette; Escarce, José J

    2004-01-01

    Objective To calculate variable-radius measures of hospital market size and create measures of competition for hospitals' markets. Data Sources Discharge abstracts from the 1997 State Inpatient Databases of the Healthcare Cost and Utilization Project (HCUP) linked with the American Hospital Association (AHA) Annual Survey, Area Resource File (ARF), InterStudy Regional Market Analysis database, and Medicare's Prospective Payment System Impact Files. Study Design Hospital radii capturing 75 and 90 percent of hospital admissions regressed against hospital and health care market characteristics and other local area characteristics, where the specification was designed to maximize predictive ability. The number of competing hospitals and the Herfindahl-Hirschman index (HHI) of competition were calculated for each hospital's market. Data Collection Methods Discharge abstracts were used to create actual radii for hospitals in nine states. These data were linked with other data describing hospital, health care market, and other characteristics. Principal Findings We explained 44.7 and 9.6 percent of the variation among urban and rural hospitals, respectively, in radii that capture 90 percent of patients, and slightly less of the variation in radii that capture 75 percent of patients. Population density; number of other hospitals in the local area; and hospital characteristics such as medical school affiliation, percentage of admissions that are Medicaid, case mix, and service offerings are important correlates of a hospital's market size. Conclusions Predicted radii and associated competition measures were created (matched to AHA hospital identifiers) for all nonfederal, short-term, general medical/surgical hospitals in the continental United States for which complete data were available in 1997 (N = 4,806) and are available from the authors. PMID:15032962

  11. A Large Radius Human Centrifuge: The Human Hypergravity Havitat

    NASA Astrophysics Data System (ADS)

    van Loon, J. J. W. A.

    2008-06-01

    Life on Earth has developed at unit gravity, 9.81 m/s2, but how would plants and animals have evolved on a larger planet, i.e. larger than Earth? We are able to address this question simply by studies using centrifuges. In the past decades numerous experiments have been performed on cells, plants and animals grown for longer durations, even multi generations, under hypergravity conditions. Based on these studies we have gained interesting insights in the physiological process of these systems when exposed to artificial gravity. Animals and plants adapt themselves to this new high-g environment. Information of adaptation to hyper-g in mammals is interesting, or maybe even proof vital, for future human space flight programs especially in light of long duration missions to Moon and Mars. We know from long duration animal studies that numerous physiological processes and structures like muscles, bones, neuro-vestibular, or the cardiovascular system are affected. However, humans have never been exposed to a hyper-g environment for long durations. Human studies are mostly in the order of hours at most. Current work on human centrifuges is all focused on short arm systems to apply artificial gravity in long duration space missions. In this paper we want to address the possible usefulness of a large radius human centrifuge on Earth, or even on Moon or Mars, for both basic research and possible applications. In such a centrifuge a group of humans may be exposed to hypergravity for, in principle, an unlimited period of time.

  12. Proton Charge Radius (PRad) Experiment at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Xiong, Weizhi; Peng, Chao; Prad Collaboration

    2016-09-01

    The PRad experiment (E12-11-106) was recently performed with 1.1 and 2.2 GeV unpolarized electron beam on a windowless H2 gas flow target in Hall B at Jefferson Lab. The experiment aims to investigate the proton radius puzzle by extracting the electric form factor of proton in an unprecedented low four-momentum transfer squared region, Q2 = 2 ×10-4 - 0 . 1(GeV / c) 2 , with a sub-percent precision. The PRad experiment utilizes a non-magnetic and calorimetric method with a high efficiency and high resolution calorimeter (HyCal) and two Gas Electron Multiplier (GEM) chambers. Its systematics are well controlled by two main advantages of this experiment: (1) The scattered electrons from M øller and e - p elastic scattering are measured simultaneously, and the e - p cross section will be normalized to the well-known M øller process; (2) The windowless gas flow target has no cell windows at both up- and downstream, which was one of the primary background sources in the previous e - p elastic scattering experiments. Thus the PRad experiment has systematic uncertainties totally different from the previous magnetic spectrometric e - p elastic scattering experiments. In this talk, we will present the details of the experimental method and preliminary analysis of the data. This work is supported in part by the U.S. Department of Energy under Contract No. DE-FG02-03ER41231, NSF MRI Award PHY-1229153, Thomas Jefferson National Laboratory and Duke University.

  13. Locking versus nonlocking palmar plate fixation of distal radius fractures.

    PubMed

    Osti, Michael; Mittler, Christoph; Zinnecker, Richard; Westreicher, Christoph; Allhoff, Clemens; Benedetto, Karl Peter

    2012-11-01

    This study compared functional and radiological outcomes after treatment of extension-type distal radius fractures with conventional titanium nonlocking T-plates or titanium 1.5-mm locking plates. A total of 60 patients were included and followed for 4 to 7 years after receiving nonlocking T-plates (group A; n=30) or locking plates (group B; n=30) with and without dorsal bone grafting. Bone grafting was significantly more often performed in the nonlocking group to increase dorsal fracture fixation and stability (P<.003). Pre- and postoperative and follow-up values for palmar tilt, radial inclination, radial shortening, and ulnar variance were recorded. Age, sex, and fracture type were similarly distributed between the 2 groups. Postoperative and follow-up evaluation revealed equal allocation of intra-articular step formation and osteoarthritic changes to both groups. The overall complication rate was 25%. Compared with the nonlocking system, patients undergoing locking plate fixation presented with statistically significantly better values for postoperative palmar tilt (5.53° vs 8.15°; P<.02) and radial inclination (22.13° vs 25.03°; P<.02). However, forearm pronation was significantly better in group A (P<.005). At follow-up, radial inclination tended to approach a statistically significant difference in favor of group B. All clinical assessment, including Mayo wrist score, Disabilities of the Arm, Shoulder, and Hand score, Green and O'Brien score, Gartland and Werley score, visual analog scale score, and grip strength, yielded no statistically significant difference between the 2 groups. Locking plates seem to provide benefits regarding surgical technique and comfort, improvement in implant anchorage (especially in osteoporotic bone), and reduce the necessity of additional bone grafting. Copyright 2012, SLACK Incorporated.

  14. Conservative Treatment of Distal Radius Fractures: A Prospective Descriptive Study.

    PubMed

    Aparicio, Pilar; Izquierdo, Óscar; Castellanos, Juan

    2017-06-01

    Disability of the upper limb is one of the consequences of distal radius fracture (DRF). The outcome of DRF treatment is based on objective clinical variables, as strength or range of movement (ROM); sometimes these variables do not correlate with the functional level of the patient. The principal objective of our study was to assess the repercussion of conservative treatment of DRF on upper limb disability. This is a retrospective review of prospectively collected data. We collected data of 61 nonconsecutive DRFs treated conservatively from July 2007 to August 2008. Average Disabilities of the Arm, Shoulder and Hand (DASH) score before fracture was 20.8 points; average DASH score after the fracture was 42.6. There was a significant increase in the upper limb disability after 1 year of follow-up in the patients treated conservatively ( P < .001; size effect, 1.06). Average radial inclination, radial tilt, and radial length were 18.18°, 3.35°, and 5.76 mm, respectively. Average ROM for flexion-extension was 100.6° and for pronation-supination 144.0°. ROM for flexion-extension of the unaffected wrist was 128.2° and for pronation-supination 172.4°. We did not find any significant statistical correlation between the increase in disability and the decrease in the ROM ( P > .05). We did not find any significant statistical correlation between the increase in the disability and the worsening in the radiological parameters ( P > .05). Our results confirm the hypothesis that the conservative treatment of DRF produced an increase in the upper limb disability after 1 year of follow-up. Our study does not show a correlation between the increase in upper limb disability and the decrease in wrist ROM. Our study did not find a correlation between radiological measures and DASH scores.

  15. Improved automatic optic nerve radius estimation from high resolution MRI

    NASA Astrophysics Data System (ADS)

    Harrigan, Robert L.; Smith, Alex K.; Mawn, Louise A.; Smith, Seth A.; Landman, Bennett A.

    2017-02-01

    The optic nerve (ON) is a vital structure in the human visual system and transports all visual information from the retina to the cortex for higher order processing. Due to the lack of redundancy in the visual pathway, measures of ON damage have been shown to correlate well with visual deficits. These measures are typically taken at an arbitrary anatomically defined point along the nerve and do not characterize changes along the length of the ON. We propose a fully automated, three-dimensionally consistent technique building upon a previous independent slice-wise technique to estimate the radius of the ON and surrounding cerebrospinal fluid (CSF) on high-resolution heavily T2-weighted isotropic MRI. We show that by constraining results to be three-dimensionally consistent this technique produces more anatomically viable results. We compare this technique with the previously published slice-wise technique using a short-term reproducibility data set, 10 subjects, follow-up <1 month, and show that the new method is more reproducible in the center of the ON. The center of the ON contains the most accurate imaging because it lacks confounders such as motion and frontal lobe interference. Long-term reproducibility, 5 subjects, follow-up of approximately 11 months, is also investigated with this new technique and shown to be similar to short-term reproducibility, indicating that the ON does not change substantially within 11 months. The increased accuracy of this new technique provides increased power when searching for anatomical changes in ON size amongst patient populations.

  16. Rights and wrongs of the temporal solar radius variability

    NASA Astrophysics Data System (ADS)

    Rozelot, J. P.; Damiani, C.

    2012-10-01

    From time immemorial men have strived to measure the size of celestial bodies. Among them, the diameter of the Sun was a source of curiosity and study. Tackled by Greek astronomers from a geometric point of view, an estimate, although incorrect, has been first determined, not truly called into question for several centuries. One must wait up to the XVIIth century to get the first precise determinations made by the French school of astronomy. Gradually, as the techniques were more and more sophisticated, many other solar diameter measurements were carried out, notably in England, Germany, Italy and US. However, even with instruments at the cutting edge of progress, no absolute value of the solar diameter has been provided yet, even if the community has adopted a canonical radius of 959''&dotbelow;63, given in all ephemeris since the end of the XIXth century. One of the major difficulties is to define a correct solar diameter. Another issue is the possible temporal variability of the size of the Sun, as first advocated at the end of the XIXth century by the Italian school. Today, this question is just on the way to being solved in spite of considerable efforts developed on ground-based facilities or on board space experiments. We will here give a review of some of the most remarkable techniques used in the past, emphasising how incorrect measurements have driven new ideas, leading to develop new statements for the underlying physics. On such new grounds, it can be speculated that the roundness of the Sun is not perfect, but developing a thin "cantaloupe skin" in periods of higher activity, with departures from sphericity being inevitably bounded by a few kilometers (around 80 km or 10 to 15 mas).

  17. Comparative biokinetics of trivalent radionuclides with similar ionic dimensions: promethium-147, curium-242 and americium-241.

    PubMed

    Priest, N D

    2007-09-01

    Data on the distribution and redistribution patterns in the laboratory rat of three trivalent elements with a similar ionic radius have been compared. This showed that these distributions for the two ions with the same ionic radius (111 pm), i.e., those of promethium (a lanthanoid) and curium (an actinoid), were indistinguishable and that americium, with a slightly larger ion size (111.5 pm), behaved similarly. The results are consistent with the suggestion that ion size is the only important factor controlling the deposition and redistribution patterns of trivalent lanthanoids and actinoids in rats. The result is important because it suggests that the same radiological protection dosimetry models should be used for trivalent actinoids and lanthanoids, that human volunteer data generated for lanthanoid isotopes can be used to predict the behavior of actinoids with the same ion size, and that appropriate pairs of beta-particle-emitting lanthanoid and alpha-particle-emitting actinoids could be used to study the relative toxicity of alpha and beta particles in experimental animals.

  18. Inelastic neutron scattering study on boson peaks of imidazolium-based ionic liquids

    SciTech Connect

    Kofu, Maiko; Inamura, Yasuhiro; Podlesnyak, Andrey A.; Ehlers, Georg; Yamamuro, Osamu; Moriya, Yosuke

    2015-07-26

    Low energy excitations of 1-alkyl-3-methylimidazolium ionic liquids (ILs) have been investigated by means of neutron spectroscopy. In the spectra of inelastic scattering, a broad excitation peak referred to as a “boson peak” appeared at 1–3 meV in all of the ILs measured. The intensity of the boson peak was enhanced at the Q positions corresponding to the diffraction peaks, reflecting the in-phase vibrational nature of the boson peak. Furthermore the boson peak energy (EBP) was insensitive to the length of the alkyl-chain but changed depending on the radius of the anion. From the correlation among EBP, the anion radius, and the glass transition temperature Tg, we conclude that both EBP and Tg in ILs are predominantly governed by the inter-ionic Coulomb interaction which is less influenced by the alkyl-chain length. Furthermore, we also found that the EBP is proportional to the inverse square root of the molecular weight as observed in molecular glasses.

  19. Inelastic neutron scattering study on boson peaks of imidazolium-based ionic liquids

    DOE PAGES

    Kofu, Maiko; Inamura, Yasuhiro; Podlesnyak, Andrey A.; ...

    2015-07-26

    Low energy excitations of 1-alkyl-3-methylimidazolium ionic liquids (ILs) have been investigated by means of neutron spectroscopy. In the spectra of inelastic scattering, a broad excitation peak referred to as a “boson peak” appeared at 1–3 meV in all of the ILs measured. The intensity of the boson peak was enhanced at the Q positions corresponding to the diffraction peaks, reflecting the in-phase vibrational nature of the boson peak. Furthermore the boson peak energy (EBP) was insensitive to the length of the alkyl-chain but changed depending on the radius of the anion. From the correlation among EBP, the anion radius, andmore » the glass transition temperature Tg, we conclude that both EBP and Tg in ILs are predominantly governed by the inter-ionic Coulomb interaction which is less influenced by the alkyl-chain length. Furthermore, we also found that the EBP is proportional to the inverse square root of the molecular weight as observed in molecular glasses.« less

  20. Minimum required capture radius in a coplanar model of the aerial combat problem

    NASA Technical Reports Server (NTRS)

    Breakwell, J. V.; Merz, A. W.

    1977-01-01

    Coplanar aerial combat is modeled with constant speeds and specified turn rates. The minimum capture radius which will always permit capture, regardless of the initial conditions, is calculated. This 'critical' capture radius is also the maximum range which the evader can guarantee indefinitely if the initial range, for example, is large. A composite barrier is constructed which gives the boundary, at any heading, of relative positions for which the capture radius is less than critical.

  1. Minimum required capture radius in a coplanar model of the aerial combat problem

    NASA Technical Reports Server (NTRS)

    Breakwell, J. V.; Merz, A. W.

    1977-01-01

    Coplanar aerial combat is modeled with constant speeds and specified turn rates. The minimum capture radius which will always permit capture, regardless of the initial conditions, is calculated. This 'critical' capture radius is also the maximum range which the evader can guarantee indefinitely if the initial range, for example, is large. A composite barrier is constructed which gives the boundary, at any heading, of relative positions for which the capture radius is less than critical.

  2. A comparison of stability and clinical outcomes in single-radius versus multi-radius femoral design for total knee arthroplasty.

    PubMed

    Jo, Ah-Reum; Song, Eun-Kyoo; Lee, Keun-Bae; Seo, Hyoung-Yeon; Kim, Sung-Kyu; Seon, Jong-Keun

    2014-12-01

    We compared the intraoperative varus-valgus stability from 0° to 90° of flexion and postoperative clinical outcomes in patients receiving TKA via either a single-radius femoral design (50 TKA, SR group) or multi-radius femoral design (50 TKA, MR group). We measured stabilities at 0°, 30°, 60° and 90° of flexion using a navigation system. The clinical outcomes including HSS scores, WOMAC scores and VAS score during stair climbing were compared after a minimum of 2-year follow-up. The single-radius femoral designs in TKA showed better intra-operative stability at 30° of flexion (7.6 vs. 8.3) compared with the multi-radius femoral design, but not at other angles. However, the clinical outcomes revealed no other significant differences in terms of HSS scores, WOMAC scores and VAS score between two groups.

  3. Infrared spectroscopy of ionic clusters

    SciTech Connect

    Price, J.M. . Dept. of Chemistry Lawrence Berkeley Lab., CA )

    1990-11-01

    This thesis describes new experiments wherein the infrared vibrational predissociation spectra of a number of mass-selected ionic cluster systems have been obtained and analyzed in the 2600 to 4000 cm{sup {minus}1} region. The species studied include: the hydrated hydronium ions, H{sub 3}O{sup +} (H{sub 2}O){sub 3 {minus}10}, ammoniated ammonium ions, NH{sub 4}{sup +}(NH{sub 3}){sub 1 {minus}10} and cluster ions involving both water and ammonia around an ammonium ion core, (mixed clusters) NH{sub 4}{sup +}(NH{sub 3}){sub n}(H{sub 2}O){sub m} (n+m=4). In each case, the spectra reveal well resolved structures that can be assigned to transitions arising from the vibrational motions of both the ion core of the clusters and the surrounding neutral solvent molecules. 154 refs., 19 figs., 8 tabs.

  4. Lattice models of ionic systems

    NASA Astrophysics Data System (ADS)

    Kobelev, Vladimir; Kolomeisky, Anatoly B.; Fisher, Michael E.

    2002-05-01

    A theoretical analysis of Coulomb systems on lattices in general dimensions is presented. The thermodynamics is developed using Debye-Hückel theory with ion-pairing and dipole-ion solvation, specific calculations being performed for three-dimensional lattices. As for continuum electrolytes, low-density results for simple cubic (sc), body-centered cubic (bcc), and face-centered cubic (fcc) lattices indicate the existence of gas-liquid phase separation. The predicted critical densities have values comparable to those of continuum ionic systems, while the critical temperatures are 60%-70% higher. However, when the possibility of sublattice ordering as well as Debye screening is taken into account systematically, order-disorder transitions and a tricritical point are found on sc and bcc lattices, and gas-liquid coexistence is suppressed. Our results agree with recent Monte Carlo simulations of lattice electrolytes.

  5. Ionic Liquids in Analytical Chemistry

    NASA Astrophysics Data System (ADS)

    Soukup-Hein, Renee J.; Warnke, Molly M.; Armstrong, Daniel W.

    2009-07-01

    The role of ionic liquids (ILs) in analytical chemistry is increasing substantially every year. A decade ago there were but a handful of papers in this area of research that were considered curiosities at best. Today, those publications are recognized as seminal articles that gave rise to one of the most rapidly expanding areas of research in chemical analysis. In this review, we briefly highlight early work involving ILs and discuss the most recent advances in separations, mass spectrometry, spectroscopy, and electroanalytical chemistry. Many of the most important advances in these fields depend on the development of new, often unique ILs and multifunctional ILs. A better understanding of the chemical and physical properties of ILs is also essential.

  6. Lipid Biomembrane in Ionic Liquids

    NASA Astrophysics Data System (ADS)

    Yoo, Brian; Jing, Benxin; Shah, Jindal; Maginn, Ed; Zhu, Y. Elaine; Department of Chemical and Biomolecular Engineering Team

    2014-03-01

    Ionic liquids (ILs) have been recently explored as new ``green'' chemicals in several chemical and biomedical processes. In our pursuit of understanding their toxicities towards aquatic and terrestrial organisms, we have examined the IL interaction with lipid bilayers as model cell membranes. Experimentally by fluorescence microscopy, we have directly observed the disruption of lipid bilayer by added ILs. Depending on the concentration, alkyl chain length, and anion hydrophobicity of ILs, the interaction of ILs with lipid bilayers leads to the formation of micelles, fibrils, and multi-lamellar vesicles for IL-lipid complexes. By MD computer simulations, we have confirmed the insertion of ILs into lipid bilayers to modify the spatial organization of lipids in the membrane. The combined experimental and simulation results correlate well with the bioassay results of IL-induced suppression in bacteria growth, thereby suggesting a possible mechanism behind the IL toxicity. National Science Foundation, Center for Research Computing at Notre Dame.

  7. Interdiffusion in binary ionic mixtures

    SciTech Connect

    Boercker, D.B.; Pollock, E.L.

    1987-08-15

    In this paper we present molecular-dynamics and kinetic-theory calculations of the interdiffusion coefficients in dense binary ionic mixtures for conditions appropriate to both astrophysical and inertial-confinement fusion (ICF) plasmas. The diffusion coefficient is the product of a Green-Kubo integral and a thermodynamic prefactor. The molecular-dynamics and kinetic-theory estimates of the Green-Kubo portion agree very well, and it is found that this integral may also be well represented by the usual concentration-weighted sum of self-diffusion coefficients. In addition, the low-density limit of the thermodynamic prefactor is shown to represent an enhancement of the diffusion by the ''ambipolar'' electric field.

  8. Influence of the ionic liquid/gas surface on ionic liquid chemistry.

    PubMed

    Lovelock, Kevin R J

    2012-04-21

    Applications such as gas storage, gas separation, NP synthesis and supported ionic liquid phase catalysis depend upon the interaction of different species with the ionic liquid/gas surface. Consequently, these applications cannot proceed to the full extent of their potential without a profound understanding of the surface structure and properties. As a whole, this perspective contains more questions than answers, which demonstrates the current state of the field. Throughout this perspective, crucial questions are posed and a roadmap is proposed to answer these questions. A critical analysis is made of the field of ionic liquid/gas surface structure and properties, and a number of design rules are mined. The effects of ionic additives on the ionic liquid/gas surface structure are presented. A possible driving force for surface formation is discussed that has, to the best of my knowledge, not been postulated in the literature to date. This driving force suggests that for systems composed solely of ions, the rules for surface formation of dilute electrolytes do not apply. The interaction of neutral additives with the ionic liquid/gas surface is discussed. Particular attention is focussed upon H(2)O and CO(2), vital additives for many applications of ionic liquids. Correlations between ionic liquid/gas surface structure and properties, ionic liquid surfaces plus additives, and ionic liquid applications are given.

  9. Effect of isospin dependence of radius on transverse flow and fragmentation in isobaric pairs

    NASA Astrophysics Data System (ADS)

    Gautam, Sakshi

    2013-11-01

    We study the role of nuclear structure effects through radius in reaction dynamics via transverse flow and multifragmentation of isobaric colliding pairs. Our study reveals that isospin-dependent radius [proposed by Royer and Rousseau [Eur. Phys. J. A10.1140/epja/i2008-10745-8 42, 541 (2009)] has significant effect towards isospin effects. The collective flow behavior and fragmentation pattern of neutron-rich system with respect to neutron-deficient system is found to get reversed with isospin-dependent radius compared to that with liquid drop radius.

  10. Evaluation of the Proton Charge Radius from Electron–Proton Scattering

    SciTech Connect

    Arrington, John; Sick, Ingo

    2015-09-15

    In light of the proton radius puzzle, the discrepancy between measurements of the proton charge radius from muonic hydrogen and those from electronic hydrogen and electron–proton (e–p) scattering measurements, we re-examine the charge radius extractions from electron scattering measurements. We provide a recommended value for the proton root-mean-square charge radius, r{sub E} = 0.879 ± 0.011 fm, based on a global examination of elastic e–p scattering data. The uncertainties include contributions to account for tension between different data sets and inconsistencies between radii using different extraction procedures.

  11. Estimation of weapon-radius versus maneuverability trade-off for air-to-air combat

    NASA Technical Reports Server (NTRS)

    Kelley, H. J.; Lefton, L.

    1977-01-01

    A chase in a horizontal plane between a pursuer with a large capture radius and a more maneuverable evading vehicle is examined with constant-speed vehicle models. An approximation to the 'sidestepping' maneuver of the Homicidal Chauffeur Game is modified to account for the effect of evader turning rate, and an estimate of capture radius required is so obtained which agrees remarkably well with Cockayne's point-capture result. The maneuver assumes central importance for barrier surfaces appearing in the Game of Two Cars. Results are given for required weapon capture-radius in terms of the maneuverability of the two vehicles. Some calculations of capture radius are presented.

  12. On the critical flame radius and minimum ignition energy for spherical flame initiation

    SciTech Connect

    Chen, Zheng; Burke, M. P.; Ju, Yiguang

    2011-01-01

    Spherical flame initiation from an ignition kernel is studied theoretically and numerically using different fuel/oxygen/helium/argon mixtures (fuel: hydrogen, methane, and propane). The emphasis is placed on investigating the critical flame radius controlling spherical flame initiation and its correlation with the minimum ignition energy. It is found that the critical flame radius is different from the flame thickness and the flame ball radius and that their relationship depends strongly on the Lewis number. Three different flame regimes in terms of the Lewis number are observed and a new criterion for the critical flame radius is introduced. For mixtures with Lewis number larger than a critical Lewis number above unity, the critical flame radius is smaller than the flame ball radius but larger than the flame thickness. As a result, the minimum ignition energy can be substantially over-predicted (under-predicted) based on the flame ball radius (the flame thickness). The results also show that the minimum ignition energy for successful spherical flame initiation is proportional to the cube of the critical flame radius. Furthermore, preferential diffusion of heat and mass (i.e. the Lewis number effect) is found to play an important role in both spherical flame initiation and flame kernel evolution after ignition. It is shown that the critical flame radius and the minimum ignition energy increase significantly with the Lewis number. Therefore, for transportation fuels with large Lewis numbers, blending of small molecule fuels or thermal and catalytic cracking will significantly reduce the minimum ignition energy.

  13. Estimation of weapon-radius versus maneuverability trade-off for air-to-air combat

    NASA Technical Reports Server (NTRS)

    Kelley, H. J.; Lefton, L.

    1977-01-01

    A chase in a horizontal plane between a pursuer with a large capture radius and a more maneuverable evading vehicle is examined with constant-speed vehicle models. An approximation to the 'sidestepping' maneuver of the Homicidal Chauffeur Game is modified to account for the effect of evader turning rate, and an estimate of capture radius required is so obtained which agrees remarkably well with Cockayne's point-capture result. The maneuver assumes central importance for barrier surfaces appearing in the Game of Two Cars. Results are given for required weapon capture-radius in terms of the maneuverability of the two vehicles. Some calculations of capture radius are presented.

  14. Ionic liquids for rechargeable lithium batteries

    SciTech Connect

    Salminen, Justin; Papaiconomou, Nicolas; Kerr, John; Prausnitz,John; Newman, John

    2005-09-29

    We have investigated possible anticipated advantages of ionic-liquid electrolytes for use in lithium-ion batteries. Thermal stabilities and phase behavior were studied by thermal gravimetric analysis and differential scanning calorimetry. The ionic liquids studied include various imidazoliumTFSI systems, pyrrolidiniumTFSI, BMIMPF{sub 6}, BMIMBF{sub 4}, and BMIMTf. Thermal stabilities were measured for neat ionic liquids and for BMIMBF{sub 4}-LiBF{sub 4}, BMIMTf-LiTf, BMIMTFSI-LiTFSI mixtures. Conductivities have been measured for various ionic-liquid lithium-salt systems. We show the development of interfacial impedance in a Li|BMIMBF{sub 4} + LiBF{sub 4}|Li cell and we report results from cycling experiments for a Li|BMIMBF{sub 4} + 1 mol/kg LIBF{sub 4}|C cell. The interfacial resistance increases with time and the ionic liquid reacts with the lithium electrode. As expected, imidazolium-based ionic liquids react with lithium electrodes. We seek new ionic liquids that have better chemical stabilities.

  15. Transverse ultrasound assessment of the flexor pollicis longus tendon movement on the distal radius during wrist and finger motion in distal radius fracture with volar plating.

    PubMed

    Nanno, Mitsuhiko; Kodera, Norie; Tomori, Yuji; Takai, Shinro

    2016-01-01

    We investigated the movement of the flexor pollicis longus (FPL) tendon on the distal radius during wrist and finger motions using transverse ultrasound in patients with distal radius fractures who underwent volar locking plating. Both wrists of 39 distal radius fracture patients with volar locking plate fixation were evaluated by transverse ultrasound to examine the location of the FPL tendon on the distal radius at varied wrist positions in full finger extension and flexion. At all wrist positions during finger motion, the FPL tendon shifted significantly more dorsally on the affected side than on the unaffected side. Additionally, at the wrist dorsal flexion position with finger flexion, the FPL tendon moved significantly the most dorsally, and the distance between the FPL tendon and the plate or the radius was the smallest among all wrist positions during finger motion. This study showed that the wrist dorsal flexion position with finger flexion could be the appropriate position to examine FPL tendon irritation after plating. Moreover, it would be effective for preventing FPL rupture to cover the FPL transverse gliding area approximately 10 mm radial to the vertex of the palmar bony prominence of the distal radius with the pronator quadratus and the intermediate fibrous zone.

  16. Influence of the ionic liquid [C4mpy][Tf2N] on the structure of the miniprotein Trp-cage.

    PubMed

    Baker, Joseph L; Furbish, Jeffrey; Lindberg, Gerrick E

    2015-11-01

    We examine the effect of the ionic liquid [C4mpy][Tf2N] on the structure of the miniprotein Trp-cage and contrast these results with the behavior of Trp-cage in water. We find the ionic liquid has a dramatic effect on Trp-cage, though many similarities with aqueous Trp-cage are observed. We assess Trp-cage folding by monitoring root mean square deviation from the crystallographic structure, radius of gyration, proline cis/trans isomerization state, protein secondary structure, amino acid contact formation and distance, and native and non-native contact formation. Starting from an unfolded configuration, Trp-cage folds in water at 298 K in less than 500 ns of simulation, but has very little mobility in the ionic liquid at the same temperature, which can be ascribed to the higher ionic liquid viscosity. At 365 K, the mobility of the ionic liquid is increased and initial stages of Trp-cage folding are observed, however Trp-cage does not reach the native folded state in 2 μs of simulation in the ionic liquid. Therefore, in addition to conventional molecular dynamics, we also employ scaled molecular dynamics to expedite sampling, and we demonstrate that Trp-cage in the ionic liquid does closely approach the aqueous folded state. Interestingly, while the reduced mobility of the ionic liquid is found to restrict Trp-cage motion, the ionic liquid does facilitate proline cis/trans isomerization events that are not seen in our aqueous simulations.

  17. Vaporisation of a dicationic ionic liquid revisited.

    PubMed

    Vitorino, Joana; Leal, João P; Licence, Peter; Lovelock, Kevin R J; Gooden, Peter N; Minas da Piedade, Manuel E; Shimizu, Karina; Rebelo, Luís P N; Canongia Lopes, José N

    2010-12-03

    The vaporization of a dicationic ionic liquid at moderate temperatures and under reduced pressures--recently studied by line-of-sight mass spectrometry--was further analyzed using an ion-cyclotron resonance mass spectroscopy technique that allows the monitoring of the different species present in the gas phase through the implementation of controlled ion-molecule reactions. The results support the view that the vapour phase of an aprotic dicationic ionic liquid is composed of neutral ion triplets (one dication attached to two anions). Molecular dynamics simulations were also performed in order to explain the magnitude of the vaporization enthalpies of dicationic ionic liquids vis-à-vis their monocationic counterparts.

  18. Quantized friction across ionic liquid thin films

    NASA Astrophysics Data System (ADS)

    Smith, Alexander M.; Lovelock, Kevin R. J.; Gosvami, Nitya Nand; Welton, Tom; Perkin, Susan

    Ionic liquids, salts in the liquid state under ambient conditions, are of great interest as precision lubricants. Ionic liquids form layered structures at surfaces, yet it is not clear how this nano-structure relates to their lubrication properties. We measured the friction force between atomically smooth solid surfaces across ionic liquid films of controlled thickness in terms of the number of ion layers. Multiple friction-load regimes emerge, each corresponding to a different number of ion layers in the film. In contrast to molecular liquids, the friction coefficients differ for each layer due to their varying composition.

  19. Modeling and experimentally characterizing ionic buoyancy engines

    NASA Astrophysics Data System (ADS)

    Akle, Barbar J.; Nasser, Jalal; Hijazi, Ahmad

    2017-04-01

    There is a need for buoyancy engines to modulate sensor depth for optimal positioning and station-keeping. Compared to current technologies, Ionic Buoyancy Engines does not have any moving parts. They are energy efficient and miniaturization ready. Ionic Buoyancy Engines change their density by locally varying ionic concentrations in a closed chamber with a wall made of a semi-permeable membrane. The local change in concentration pumps water in and out of the chamber leading to buoyancy change. This study presents a model that is used to simulate the steady state controlled depth of the buoyancy engine, along with experimental results.

  20. Quantized friction across ionic liquid thin films.

    PubMed

    Smith, Alexander M; Lovelock, Kevin R J; Gosvami, Nitya Nand; Welton, Tom; Perkin, Susan

    2013-10-07

    Ionic liquids - salts in the liquid state under ambient conditions - are of great interest as precision lubricants. Ionic liquids form layered structures at surfaces, yet it is not clear how this nano-structure relates to their lubrication properties. We measured the friction force between atomically smooth solid surfaces across ionic liquid films of controlled thickness in terms of the number of ion layers. Multiple friction-load regimes emerge, each corresponding to a different number of ion layers in the film. In contrast to molecular liquids, the friction coefficients differ for each layer due to their varying composition.

  1. Alkaline ionic liquids applied in supported ionic liquid catalyst for selective hydrogenation of citral to citronellal

    NASA Astrophysics Data System (ADS)

    Salminen, Eero; Virtanen, Pasi; Mikkola, Jyri-Pekka

    2014-02-01

    The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat) benzalkonium [ADBA] (alkyldimethylbenzylammonium) was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths and is commonly used in the formulation of various antiseptic products. The prepared ionic liquids were utilized as Supported Ionic Liquid Catalysts (SILCAs). Typically, a SILCA contains metal nanoparticles, enzymes or metal complexes in an ionic liquid layer which is immobilized on a solid carrier material such as an active carbon cloth (ACC). The catalysts were applied in the selective hydrogenation of citral to citronellal which is an important perfumery chemical. Interestingly, 70 % molar yield towards citronellal was achieved over a catalyst containing the alkaline ionic liquid benzalkonium methoxide.

  2. Alkaline ionic liquids applied in supported ionic liquid catalyst for selective hydrogenation of citral to citronellal

    PubMed Central

    Salminen, Eero; Virtanen, Pasi; Mikkola, Jyri-Pekka

    2014-01-01

    The challenge in preparation of ionic liquids containing a strong alkaline anion is to identify a suitable cation which can tolerate the harsh conditions induced by the anion. In this study, a commercial quaternary ammonium compound (quat) benzalkonium [ADBA] (alkyldimethylbenzylammonium) was used as a cation in the synthesis of different alkaline ionic liquids. In fact, the precursor, benzalkonium chloride, is a mixture of alkyldimethylbenzylammonium chlorides of various alkyl chain lengths and is commonly used in the formulation of various antiseptic products. The prepared ionic liquids were utilized as Supported Ionic Liquid Catalysts (SILCAs). Typically, a SILCA contains metal nanoparticles, enzymes, or metal complexes in an ionic liquid layer which is immobilized on a solid carrier material such as an active carbon cloth (ACC). The catalysts were applied in the selective hydrogenation of citral to citronellal which is an important perfumery chemical. Interestingly, 70% molar yield toward citronellal was achieved over a catalyst containing the alkaline ionic liquid benzalkonium methoxide. PMID:24790972

  3. The Unstable Distal Radius Fracture—How Do We Define It? A Systematic Review

    PubMed Central

    Walenkamp, Monique M. J.; Vos, Lara M.; Strackee, Simon D.; Goslings, J. Carel; Schep, Niels W. L.

    2015-01-01

    Background Unstable distal radius fractures are a popular research subject. However, to appreciate the findings of studies that enrolled patients with unstable distal radius fractures, it should be clear how the authors defined an unstable distal radius fracture. Questions In what percentage of studies involving patients with unstable distal radius fractures did the authors define unstable distal radius fracture? What are the most common descriptions of an unstable distal radius fracture? And is there one preferred evidence-based definition for future authors? Methods A systematic search of literature was performed to identify any type of study with the term unstable distal radius fracture. We assessed whether a definition was provided and determined the level of evidence for the most common definitions. Results The search yielded 2,489 citations, of which 479 were included. In 149 studies, it was explicitly stated that patients with unstable distal radius fractures were enrolled. In 54% (81/149) of these studies, the authors defined an unstable distal radius fracture. Overall, we found 143 different definitions. The seven most common definitions were: displacement following adequate reduction; Lafontaine's definition; irreducibility; an AO type C2 fracture; a volarly displaced fracture; Poigenfürst's criteria; and Cooney's criteria. Only Lafontaine's definition originated from a clinical study (level IIIb). Conclusion In only half of the studies involving patients with an unstable distal radius fracture did the authors defined what they considered an unstable distal radius fracture. None of the definitions stood out as the preferred choice. A general consensus definition could help to standardize future research. PMID:26649263

  4. Synthesis of hetero ionic compounds using dialkylcarbonate quaternization

    DOEpatents

    Friesen, Cody A.; Wolfe, Derek; Johnson, Paul Bryan

    2017-09-19

    Methods of preparing hetero ionic complexes, and ionic liquids from bisulfate salts of heteroatomic compounds using dialkylcarbonates as a primary quaternizing reactant are disclosed. Also disclosed are methods of making electrochemical cells comprising the ionic liquids, and an electrochemical cell comprising an alkaline electrolyte and a hetero ionic complex additive.

  5. Morphology and Ionic Conductivity of Block Copolymer--Ionic Liquid Systems

    NASA Astrophysics Data System (ADS)

    Hoarfrost, M. L.; Virgili, J. M.; Kerr, J. B.; Segalman, R. A.

    2009-03-01

    Block copolymer--ionic liquid systems are of interest for ion exchange membranes due to the ionic conductivity and thermal stability of the ionic liquid combined with the thermal stability and morphological control arising from a structural component in a block copolymer. It is anticipated that the morphology and connectivity of the resulting structural and ionic liquid-containing nanodomains will affect conduction properties. This relationship was investigated for poly(styrene-b-2-vinylpyridine) (S2VP) in ionic liquids composed of varying molar ratios of imidazole and bis(trifluoromethanesulfonyl)imide (Im:TFSI). A stoichiometrically balanced ionic liquid (1:1 Im:TFSI) swells the 2VP lamellar domains for copolymer concentrations as low as 60wt%. With 9:1 Im:TFSI the lamellar structure tolerates more swelling, forming lamellar structures with as little as 30wt% copolymer. Ionic conductivities were derived from AC impedance measurements. The S2VP-Im:TFSI systems, characterized by microphase separated domains, demonstrate ionic conductivities comparable to those of P2VP--ionic liquid systems when normalized by 2VP (monomer) to Im:TFSI ratio.

  6. Ionic liquid polyoxometalates as light emitting materials

    SciTech Connect

    Ortiz-acosta, Denisse; Del Sesto, Rico E; Scott, Brian; Bennett, Bryan L; Purdy, Geraldine M; Muenchausen, Ross E; Mc Kigney, Edward; Gilbertson, Robert

    2008-01-01

    The low melting point, negligible vapor pressure, good solubility, and thermal and chemical stability make ionic liquids useful materials for a wide variety of applications. Polyoxometalates are early transition metal oxygen clusters that can be synthesized in many different sizes and with a variety of heterometals. The most attractive feature of POMs is that their physical properties, in particular electrical, magnetic, and optical properties, can be easily modified following known procedures. It has been shown that POMs can exhibit cooperative properties, as superconductivity and energy transfer. POM ionic liquids can be obtained by selecting the appropliate cation. Different alkyl ammonium and alkyl phosphonium salts are being used to produce new POM ionic liquids together with organic or inorganic luminescent centers to design light emitting materials. Ammonium and phosphonium cations with activated, polymerizable groups are being used to further polymerize the ionic liquid into transparent, solid materials with high metal density.

  7. Aqueous ionic liquid pretreatment of straw.

    PubMed

    Fu, Dongbao; Mazza, Giuseppe

    2011-07-01

    Pretreatment is the key to unlock the recalcitrance of lignocellulose for cellulosic biofuels production. Increasing attention has been drawn to ionic liquids (ILs) for pretreatment of lignocellulosic biomass, because this approach has several advantages over conventional methods. However, cost and energy-intensive recycling of the solvents are major constraints preventing ILs from commercial viability. In this work, a mixture of ionic liquid 1-ethyl-3-methylimidazolium acetate and water was demonstrated to be effective for pretreatment of lignocellulosic biomass, evidenced by the removal of lignin and a reduction in cellulose crystallinity. A higher fermentable sugar yield (81%) was obtained than for pure ionic liquid pretreatment under the same conditions (67%). Aqueous ionic liquid pretreatment has the advantages of less usage and easier recycling of ILs, and reduced viscosity. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  8. Modeling electrokinetics in ionic liquids: General

    DOE PAGES

    Wang, Chao; Bao, Jie; Pan, Wenxiao; ...

    2017-04-01

    Using direct numerical simulations, we provide a thorough study regarding the electrokinetics of ionic liquids. In particular, modified Poisson–Nernst–Planck equations are solved to capture the crowding and overscreening effects characteristic of an ionic liquid. For modeling electrokinetic flows in an ionic liquid, the modified Poisson-Nernst-Planck equations are coupled with Navier–Stokes equations to study the coupling of ion transport, hydrodynamics, and electrostatic forces. Specifically, we consider the ion transport between two parallel charged surfaces, charging dynamics in a nanopore, capacitance of electric double-layer capacitors, electroosmotic flow in a nanochannel, electroconvective instability on a plane ion-selective surface, and electroconvective flow on amore » curved ionselective surface. Lastly, we also discuss how crowding and overscreening and their interplay affect the electrokinetic behaviors of ionic liquids in these application problems.« less

  9. Nanoscale Ionic Aggregate Morphology in Zwitterionic Copolymers

    NASA Astrophysics Data System (ADS)

    Choi, Jae-Hong; Huyck, Rebecca; Salas-de La Cruz, David; Long, Timothy E.; Winey, Karen I.

    2009-03-01

    The morphology of two different zwitterionic copolymers, poly(sulfobetaine methacrylate-ran-butyl acrylate), and poly(sulfobetaine methacrylamide-ran-butyl acrylate) are investigated as a function of the mol % content of SBMA (7 and 9 mol %) and SBMAm (6, 10 and 13 mol %), respectively. In both copolymers, X-ray scattering results show a new structure in the material arising from ionic aggregates. The sizes of the ionic aggregates are obtained through the scattering model. The sizes of the ionic aggregates increase as the ion content increases. The application of scanning transmission electron microscopy to the study of ionomer morphology has enabled direct, model-independent visualization of the ionic aggregates. The correlation between X-ray scattering results and the real space imaging for morphology of these zwitterionic copolymers will be presented.

  10. Ionic Liquid-Based Microemulsions in Catalysis.

    PubMed

    Hejazifar, Mahtab; Earle, Martyn; Seddon, Kenneth R; Weber, Stefan; Zirbs, Ronald; Bica, Katharina

    2016-12-16

    The design and properties of surface-active ionic liquids that are able to form stable microemulsions with heptane and water are presented, and their promise as reaction media for thermomorphic palladium-catalyzed cross-coupling reactions is demonstrated.

  11. Thermodynamic Analysis of Ionic Compounds: Synthetic Applications.

    ERIC Educational Resources Information Center

    Yoder, Claude H.

    1986-01-01

    Shows how thermodynamic cycles can be used to understand trends in heats of formation and aqueous solubilities and, most importantly, how they may be used to choose synthetic routes to new ionic compounds. (JN)

  12. IMPROVED SYNTHESIS OF ROOM TEMPERATURE IONIC LIQUIDS

    EPA Science Inventory

    Room temperature ionic liquids (RTILs), molten salts comprised of N-alkylimidazolium cations and various anions, have received significant attention due to their commercial potential in a variety of chemical applications especially as substitutes for conventional volatile organic...

  13. Thermodynamic Analysis of Ionic Compounds: Synthetic Applications.

    ERIC Educational Resources Information Center

    Yoder, Claude H.

    1986-01-01

    Shows how thermodynamic cycles can be used to understand trends in heats of formation and aqueous solubilities and, most importantly, how they may be used to choose synthetic routes to new ionic compounds. (JN)

  14. IMPROVED SYNTHESIS OF ROOM TEMPERATURE IONIC LIQUIDS

    EPA Science Inventory

    Room temperature ionic liquids (RTILs), molten salts comprised of N-alkylimidazolium cations and various anions, have received significant attention due to their commercial potential in a variety of chemical applications especially as substitutes for conventional volatile organic...

  15. Phosphonium-based ionic liquids and uses

    SciTech Connect

    Del Sesto, Rico E; Koppisch, Andrew T; Lovejoy, Katherine S; Purdy, Geraldine M

    2014-12-30

    Phosphonium-based room temperature ionic liquids ("RTILs") were prepared. They were used as matrices for Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry and also for preparing samples of dyes for analysis.

  16. Molecular dynamics study of the vaporization of an ionic drop

    NASA Astrophysics Data System (ADS)

    Galamba, N.

    2010-09-01

    The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (NanCln)n=2-4. The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

  17. Crown radius and diameter at breast height relationships for six bottomland hardwood species

    Treesearch

    Brian Roy Lockhart; Robert C. Weih; Keith M. Smith

    2005-01-01

    The relationship between a tree's crown radius and diameter at breast height (DBH) has a variety of uses including forest competition studies, tree crown densities, spacing and stocking relationships, wildlife habitat suitability models, and tree volume estimations. Estimating DBH from mean crown radius (MCR) is of interest to natural resource managers because MCR...

  18. Active space of pheromone plume and its relationship to effective attraction radius in applied models

    USDA-ARS?s Scientific Manuscript database

    Any lure’s semiochemical release rate that is attractive to flying insects has a specific effective attraction radius (EAR) that corresponds to the lure’s orientation response strength. The EAR was defined as the radius of a passive sphere that would intercept the same number of insects as a semioch...

  19. Fast Ignition and Sustained Combustion of Ionic Liquids

    NASA Technical Reports Server (NTRS)

    Joshi, Prakash B. (Inventor); Piper, Lawrence G. (Inventor); Oakes, David B. (Inventor); Sabourin, Justin L. (Inventor); Hicks, Adam J. (Inventor); Green, B. David (Inventor); Tsinberg, Anait (Inventor); Dokhan, Allan (Inventor)

    2016-01-01

    A catalyst free method of igniting an ionic liquid is provided. The method can include mixing a liquid hypergol with a HAN (Hydroxylammonium nitrate)-based ionic liquid to ignite the HAN-based ionic liquid in the absence of a catalyst. The HAN-based ionic liquid and the liquid hypergol can be injected into a combustion chamber. The HAN-based ionic liquid and the liquid hypergol can impinge upon a stagnation plate positioned at top portion of the combustion chamber.

  20. Superbase-derived protic ionic liquids

    DOEpatents

    Dai, Sheng; Luo, Huimin; Baker, Gary A.

    2013-09-03

    Protic ionic liquids having a composition of formula (A.sup.-)(BH.sup.+) wherein A.sup.- is a conjugate base of an acid HA, and BH.sup.+ is a conjugate acid of a superbase B. In particular embodiments, BH.sup.+ is selected from phosphazenium species and guanidinium species encompassed, respectively, by the general formulas: ##STR00001## The invention is also directed to films and membranes containing these protic ionic liquids, with particular application as proton exchange membranes for fuel cells.

  1. Ionic conductors for solid oxide fuel cells

    DOEpatents

    Krumpelt, Michael; Bloom, Ira D.; Pullockaran, Jose D.; Myles, Kevin M.

    1993-01-01

    An electrolyte that operates at temperatures ranging from 600.degree. C. to 800.degree. C. is provided. The electrolyte conducts charge ionically as well as electronically. The ionic conductors include molecular framework structures having planes or channels large enough to transport oxides or hydrated protons and having net-positive or net-negative charges. Representative molecular framework structures include substituted aluminum phosphates, orthosilicates, silicoaluminates, cordierites, apatites, sodalites, and hollandites.

  2. Ionic liquids in the synthesis of nanoobjects

    NASA Astrophysics Data System (ADS)

    Tarasova, Natalia P.; Smetannikov, Yurii V.; Zanin, A. A.

    2010-08-01

    Data on the usage of the novel green solvents, ionic liquids, in the synthesis of nanoobjects and their stabilization are considered. The information is structured according to the resulting products of the synthetic processes: nanoparticles of noble metals, nanoparticles of non-metals, nanoparticles of metal oxides and chalcogenides, nanocomposites, and highly dispersed polymers. The conclusion is made that the ionic liquids might determine the structure and the properties of the nanoobjects, thus opening new fundamental and technological horizons in nanochemistry.

  3. The Solubility Parameters of Ionic Liquids

    PubMed Central

    Marciniak, Andrzej

    2010-01-01

    The Hildebrand’s solubility parameters have been calculated for 18 ionic liquids from the inverse gas chromatography measurements of the activity coefficients at infinite dilution. Retention data were used for the calculation. The solubility parameters are helpful for the prediction of the solubility in the binary solvent mixtures. From the solubility parameters, the standard enthalpies of vaporization of ionic liquids were estimated. PMID:20559495

  4. Ionic conductors for solid oxide fuel cells

    SciTech Connect

    Krumpelt, M.; Bloom, I.D.; Pullockaran, J.D.; Myles, K.M.

    1991-12-31

    An electrolyte that operates at temperatures ranging from 600{degree}C to 800{degree}C is discussed. The electrolyte conducts charge ionically as well as electronically. The ionic conductors include molecular framework structures having planes or channels large enough to transport oxides or hydrated protons and having net-positive or net-negative charges. Representative molecular framework structures include substituted aluminum phosphates, orthosilicates, silicoaluminates, cordierites, apatites, sodalites, and hollandites.

  5. The Muon Scattering Experiment (MUSE) at PSI and the proton radius puzzle

    NASA Astrophysics Data System (ADS)

    Kohl, Michael

    2014-11-01

    The unexplained large discrepancy of the proton charge radius measurements with muonic hydrogen Lamb shift and determinations from elastic electron scattering and Lamb shift in regular hydrogen of seven standard deviations is known as the proton radius puzzle. Suggested solutions of the puzzle range from possible errors in the experiments through unexpectedly large hadronic physics effects to new physics beyond the Standard Model. A new approach to verify the radius discrepancy in a systematic manner will be pursued with the Muon Scattering Experiment (MUSE) at PSI. The experiment aims to compare elastic cross sections, the proton elastic form factors, and the extracted proton charge radius with scattering of electrons and muons of either charge and under identical conditions. The difference in the observed radius will be probed with a high precision to verify the discrepancy. An overview of the experiment and the current status will be presented.

  6. The weighted average test method for the maximum radius of a laser-induced bubble

    NASA Astrophysics Data System (ADS)

    Beibei, Li; Ruirui, Li; Bingyang, Wang; Jie, He; Zheng, Ding; Xiumei, Liu

    2017-05-01

    The weighted average test method for the laser-induced bubble’s maximum radius was investigated in the paper. In order to reduce the random error of the measurement results, the weighted factor and weighted average formula of the bubble’s maximum radius and its standard deviation were proposed based on the theory of unequal precision measurement. The results indicated that the probability of the characteristic signals obtained by experiment agree well with the theoretical predictions, and the standard deviation for the weighted average maximum radius is smaller than the spatial resolution of the 2D platform. This shows that the weighted average test method can increase the accuracy of the measurement of the maximum radius. These results are useful for measuring the maximum radius and the laser process under water.

  7. Determining the waist radius of a focused Gaussian laser beam using a millimeter-scale ruler

    NASA Astrophysics Data System (ADS)

    Yang, Pao-Keng; Liu, Jian-You

    2017-03-01

    We present a simple and inexpensive method for determining the waist radius of a focused Gaussian laser beam. This method is motivated by the fact that if you focus the laser beam using a lens, the distance from the lens to the waist will vary slightly as the lens is moved along the beam-propagating direction. We show how the waist radius can be calculated from four large longitudinal lengths, measurable using a conventional millimeter-scale ruler. Analyzing the dependence of the calculated waist radius on these four measured lengths numerically shows that the accuracy of the calculated waist radius is mainly affected by the error in the relative shift in the distance from the lens to the waist position. The calculated waist radius for a real HeNe laser is close to the one measured directly using a commercial beam profiler with an error within 7%.

  8. The distillation and volatility of ionic liquids.

    PubMed

    Earle, Martyn J; Esperança, José M S S; Gilea, Manuela A; Lopes, José N Canongia; Rebelo, Luís P N; Magee, Joseph W; Seddon, Kenneth R; Widegren, Jason A

    2006-02-16

    It is widely believed that a defining characteristic of ionic liquids (or low-temperature molten salts) is that they exert no measurable vapour pressure, and hence cannot be distilled. Here we demonstrate that this is unfounded, and that many ionic liquids can be distilled at low pressure without decomposition. Ionic liquids represent matter solely composed of ions, and so are perceived as non-volatile substances. During the last decade, interest in the field of ionic liquids has burgeoned, producing a wealth of intellectual and technological challenges and opportunities for the production of new chemical and extractive processes, fuel cells and batteries, and new composite materials. Much of this potential is underpinned by their presumed involatility. This characteristic, however, can severely restrict the attainability of high purity levels for ionic liquids (when they contain poorly volatile components) in recycling schemes, as well as excluding their use in gas-phase processes. We anticipate that our demonstration that some selected families of commonly used aprotic ionic liquids can be distilled at 200-300 degrees C and low pressure, with concomitant recovery of significant amounts of pure substance, will permit these currently excluded applications to be realized.

  9. Supported ionic liquid membrane in membrane reactor

    NASA Astrophysics Data System (ADS)

    Makertihartha, I. G. B. N.; Zunita, M.; Dharmawijaya, P. T.; Wenten, I. G.

    2017-01-01

    Membrane reactor is a device that integrates membrane based separation and (catalytic) chemical reaction vessel in a single device. Ionic liquids, considered to be a relatively recent magical chemical due to their unique properties, have a large variety of applications in all areas of chemical industries. Moreover, the ionic liquid can be used as membrane separation layer and/or catalytically active site. This paper will review utilization of ionic liquid in membrane reactor related applications especially Fischer-Tropsch, hydrogenation, and dehydrogenation reaction. This paper also reviews about the capability of ionic liquid in equilibrium reaction that produces CO2 product so that the reaction will move towards the product. Water gas shift reaction in ammonia production also direct Dimethyl Ether (DME) synthesis that produces CO2 product will be discussed. Based on a review of numerous articles on supported ionic liquid membrane (SILM) indicate that ionic liquids have the potential to support the process of chemical reaction and separation in a membrane reactor.

  10. The distillation and volatility of ionic liquids

    NASA Astrophysics Data System (ADS)

    Earle, Martyn J.; Esperança, José M. S. S.; Gilea, Manuela A.; Canongia Lopes, José N.; Rebelo, Luís P. N.; Magee, Joseph W.; Seddon, Kenneth R.; Widegren, Jason A.

    2006-02-01

    It is widely believed that a defining characteristic of ionic liquids (or low-temperature molten salts) is that they exert no measurable vapour pressure, and hence cannot be distilled. Here we demonstrate that this is unfounded, and that many ionic liquids can be distilled at low pressure without decomposition. Ionic liquids represent matter solely composed of ions, and so are perceived as non-volatile substances. During the last decade, interest in the field of ionic liquids has burgeoned, producing a wealth of intellectual and technological challenges and opportunities for the production of new chemical and extractive processes, fuel cells and batteries, and new composite materials. Much of this potential is underpinned by their presumed involatility. This characteristic, however, can severely restrict the attainability of high purity levels for ionic liquids (when they contain poorly volatile components) in recycling schemes, as well as excluding their use in gas-phase processes. We anticipate that our demonstration that some selected families of commonly used aprotic ionic liquids can be distilled at 200-300°C and low pressure, with concomitant recovery of significant amounts of pure substance, will permit these currently excluded applications to be realized.

  11. Aqueous Solutions of Ionic Liquids: Microscopic Assembly.

    PubMed

    Vicent-Luna, Jose Manuel; Dubbeldam, David; Gómez-Álvarez, Paula; Calero, Sofia

    2016-02-03

    Aqueous solutions of ionic liquids are of special interest, due to the distinctive properties of ionic liquids, in particular, their amphiphilic character. A better understanding of the structure-property relationships of such systems is hence desirable. One of the crucial molecular-level interactions that influences the macroscopic behavior is hydrogen bonding. In this work, we conduct molecular dynamics simulations to investigate the effects of ionic liquids on the hydrogen-bond network of water in dilute aqueous solutions of ionic liquids with various combinations of cations and anions. Calculations are performed for imidazolium-based cations with alkyl chains of different lengths and for a variety of anions, namely, [Br](-), [NO3](-), [SCN](-) [BF4](-), [PF6](-), and [Tf2N](-). The structure of water and the water-ionic liquid interactions involved in the formation of a heterogeneous network are analyzed by using radial distribution functions and hydrogen-bond statistics. To this end, we employ the geometric criterion of the hydrogen-bond definition and it is shown that the structure of water is sensitive to the amount of ionic liquid and to the anion type. In particular, [SCN](-) and [Tf2N](-) were found to be the most hydrophilic and hydrophobic anions, respectively. Conversely, the cation chain length did not influence the results.

  12. Counterion condensation and ionic conductivity

    NASA Astrophysics Data System (ADS)

    Penafiel, L. Miguel; Litovitz, Theodore A.

    1992-02-01

    The occurrence of counterion condensation is demonstrated through measurements of the incremental ionic conductivity of pH buffered Na polyacrylate solutions. pH values were selected to allow variation of the charge density parameter ξ in the range between 0.4 and 2.8, that is, across ξ=1, the theoretical critical level for counterion condensation. The results show two regions where the incremental conductivity, ΔσP, varies differently with ξ. For ξ<1.3, ΔσP remains relatively constant. A sharp drop in ΔσP is observed between ξ=1.3 and ξ=1.7 corresponding to the onset of counterion condensation. It is suggested that this discontinuity reflects a drastic change in the polyion mobility caused by a structural rearrangement of the macromolecule. For ξ≳1.7, ΔσP decreases with approximately constant slope. This latter behavior agrees qualitatively but not quantitatively with the prediction of the counterion condensation model.

  13. Ionic waves in animal tissues

    NASA Astrophysics Data System (ADS)

    Nobili, Renato

    1987-02-01

    A proof is given that self-sustaining ionic-wave propagations-heuristically inferred by the author in a previous paper [Phys. Rev. A 32, 3618 (1985)] concerning a new holographic theory of animal memory-are possible in animal tissues at normal physiological conditions. The proof is obtained by standard electrochemical methods purely on the basis of well-known properties of cell membranes and of molecular devices found in them. It is shown that interstitial pockets filled with extracellular fluid, when viewed as functional units dispersed all over the cell tissue, promote ion currents proportionally to linear combinations of macroscopic sodium and potassium concentration gradients. Oscillations of sodium and potassium macroscopic concentrations prove to be possible thanks to the voltage-driven amplification function for ion fluxes exerted by Na+-K+-ATPase (adenosinetriphosphatase) pumps and to the feedback control role exerted by the (Na+ antiports Ca2+)-->(Ca2+ activates K+) channel system. All steps in deriving the wave equations are coarse-graining invariant; this ensures the correctness of the macroscopic view in treating the problem. Theoretical wave patterns and their general features are in excellent agreement with EEG (electroencephalogram) patterns detected on brain cortices and on scalps. Epileptic foci artificially generated by injection of Na+ ions into glial tissue and inhibition of EEG by K+ superfusion of brain cortex, are correctly accounted for by the theory.

  14. Ionic liquids in separation techniques.

    PubMed

    Berthod, A; Ruiz-Angel, M J; Carda-Broch, S

    2008-03-14

    The growing interest in ionic liquids (ILs) has resulted in an exponentially increasing production of analytical applications. The potential of ILs in chemistry is related to their unique properties as non-molecular solvents: a negligible vapor pressure associated to a high thermal stability. ILs found uses in different sub-disciplines of analytical chemistry. After drawing a rapid picture of the physicochemical properties of selected ILs, this review focuses on their use in separation techniques: gas chromatography (GC), liquid chromatography (LC) and electrophoretic methods (CE). In LC and CE, ILs are not used as pure solvents, but rather diluted in aqueous solutions. In this situation ILs are just salts. They are dual in nature. Too often the properties of the cations are taken as the properties of the IL itself. The lyotropic theory is recalled and the effects of a chaotropic anion are pointed out. Many results can be explained considering all ions present in the solution. Ion-pairing and ion-exchange mechanisms are always present, associated with hydrophobic interactions, when dealing with IL in diluted solutions. Chromatographic and electrophoretic methods are also mainly employed for the control and monitoring of ILs. These methods are also considered. ILs will soon be produced on an industrial scale and it will be necessary to develop reliable analytical procedures for their analysis and control.

  15. Characterisation of cationic potato starch by asymmetrical flow field-flow fractionation. Influence of ionic strength and degree of substitution.

    PubMed

    Santacruz, Stalin

    2014-06-15

    The properties of a paper sheet depend on the absorption together with the physico-chemical properties of additives used in the paper processing. The effect of ionic strength and degree of substitution of cationic potato starch on the elution pattern of asymmetrical flow field-flow fractionation was analysed. The effect of starch derivatisation, in either dry or wet phase, was also investigated. Average molar mass showed no difference between the starches obtained from the two derivatisation processes. Apparent densities showed that dry cationic starch had higher density than wet cationic starch for a hydrodynamic radius between 50 and 100 nm. Elution times of native and three cationic starches increased when the ionic strength increased from 50 to 100mM. No differences in the molar mass among cationic starches with different degree of substitution suggested no degradation due to a derivatisation process. Large sample loads can be used at 100mM without overloading.

  16. The Amphiphilic Character of Cellulose Molecules in True Solution in Solvent Mixtures Containing Ionic Liquid and its Utilization in Emulsification

    NASA Astrophysics Data System (ADS)

    Napso, Sofia; Cohen, Yachin; Rein, Dmitry; Khalfin, Rafail; Szekely, Noemi

    2015-03-01

    Cellulose is the most abundant renewable material in nature that is utilized as a raw material for fabrication of synthetic products. Although it is not soluble in common solvents, there is significant interest in the use of solvent mixtures containing ionic liquids (IL) and polar organic solvents for cellulose dissolution. We present evidence for true molecular dissolution of cellulose in binary mixtures of common polar organic solvents with an ionic liquid, using cryogenic transmission electron microscopy, small-angle neutron-, x-ray- and static light scattering. In particular, the measured low values of the molecular, gyration radius and persistence length indicate the absence of significant aggregation of the dissolved chains. We conjecture that the dissolved cellulose chains are amphiphilic. This can be inferred from the facile fabrication of cellulose-encapsulated colloidal oil-in-water or water-in-oil dispersions. This may be done by mixing water, oil and cellulose solution in an ionic liquid. A more practical alternative is to form first a hydrogel from the cellulose/ionic liquid solution by coagulation with water and applying it to sonicated water/oil or oil/water mixtures. Apparently the dissolution/ regeneration process affords higher mobility to the cellulose molecules so an encapsulation coating can be formed at the water-oil interface.

  17. Local A-Site Layering in Rare-Earth Orthochromite Perovskites by Solution Synthesis.

    PubMed

    Daniels, Luke M; Kashtiban, Reza J; Kepaptsoglou, Demie; Ramasse, Quentin M; Sloan, Jeremy; Walton, Richard I

    2016-12-19

    Cation size effects were examined in the mixed A-site perovskites La0.5 Sm0.5 CrO3 and La0.5 Tb0.5 CrO3 prepared through both hydrothermal and solid-state methods. Atomically resolved electron energy loss spectroscopy (EELS) in the transmission electron microscope shows that while the La and Sm cations are randomly distributed, increased cation-radius variance in La0.5 Tb0.5 CrO3 results in regions of localised La and Tb layers, an atomic arrangement exclusive to the hydrothermally prepared material. Solid-state preparation gives lower homogeneity resulting in separate nanoscale regions rich in La(3+) and Tb(3+) . The A-site layering in hydrothermal La0.5 Tb0.5 CrO3 is randomised upon annealing at high temperature, resulting in magnetic behaviour that is dependent on synthesis route. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  18. Acidic precipitation at a site within the northeastern conurbation

    Treesearch

    Jay S. Jacobson; Laurence I. Heller; Paul Van Leuken

    1976-01-01

    Rain and snow were collected in plastic beakers either manually or with a Wong sampler during 58 precipitation events in 1974 at Yonkers, New York approximately 24 km north of the center of New York City. Determinations were made of total dissolved ionic species, free hydrogen ions, total hydrogen ions, sulfate, nitrate, chloride, and fluoride. Conductivity...

  19. Size Control and Fractionation of Ionic Liquid Filled Polymersomes with Glassy and Rubbery Bilayer Membranes.

    PubMed

    So, Soonyong; Lodge, Timothy P

    2016-05-17

    We demonstrate control over the size of ionic liquid (IL) filled polymeric vesicles (polymersomes) by three distinct methods: mechanical extrusion, cosolvent-based processing in an IL, and fractionation of polymersomes in a biphasic system of IL and water. For the representative ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([EMIM][TFSI])), the size and dispersity of polymersomes formed from 1,2-polybutadiene-b-poly(ethylene oxide) (PB-PEO) and polystyrene-b-poly(ethylene oxide) (PS-PEO) diblock copolymers were shown to be sensitive to assembly conditions. During mechanical extrusion through a polycarbonate membrane, the relatively larger polymersomes were broken up and reorganized into vesicles with mean size comparable to the membrane pore (100 nm radius); the distribution width also decreased significantly after only a few passes. Other routes were studied using the solvent-switch or cosolvent (CS) method, whereby the initial content of the cosolvent and the PEO block length of PS-PEO were systemically changed. The nonvolatility of the ionic liquid directly led to the desired concentration of polymersomes in the ionic liquid using a single step, without the dialysis conventionally used in aqueous systems, and the mean vesicle size depended on the amount of cosolvent employed. Finally, selective phase transfer of PS-PEO polymersomes based on size was used to extract larger polymersomes from the IL to the aqueous phase via interfacial tension controlled phase transfer. The interfacial tension between the PS membrane and the aqueous phase was varied with the concentration of sodium chloride (NaCl) in the aqueous phase; then the larger polymersomes were selectively separated to the aqueous phase due to differences in shielding of the hydrophobic core (PS) coverage by the hydrophilic corona brush (PEO). This novel fractionation is a simple separation process without any special apparatus and can help to prepare monodisperse polymersomes

  20. Role of Ionic Clusters in Dynamics of Ionomer Melts: From Atomistic to Coarse Grained Simulations

    NASA Astrophysics Data System (ADS)

    Agrawal, Anupriya

    Ionomers, polymers decorated with ionizable groups, have found application in numerous technologies where ionic transport is required. The ionic groups associate into random clusters resulting in substantial effect on structure, dynamics and transport of these materials. The effects of topology, size and dynamics of these aggregates however remain an open question. Here we probe cluster formation correlated with polymer dynamics through a model system of randomly sulfonated polystyrene (SPS) melts with molecular dynamics (MD) simulations over a broad time and length scales ranging from that within the ionic clusters through polymer segmental dynamics to the motion of the entire molecules. The cluster evolution was probed by fully atomistic studies. We find ladder-like aggregates that transform to globule-like with increasing the dielectric constant of media for sodium neutralized SPS. With increasing dielectric constant, the size of the aggregates decrease and their number increases. Concurrently, the mobility of the polymer increases. The counterion radius and valency affect both morphology and dynamics as is evident in the calculated static and dynamic structure factors. It is further manifested in the results of viscosity obtained through non-equilibrium molecular dynamics technique. Finally, to access larger length scales a three bead coarse-grained model to describe sulfonated styrene that we have developed will be discussed in view of the outstanding challenges in ionic polymers. Supported in part by DOE Grant No. DE-SC007908. This work was carried out in collaboration with Dvora Perahia and Gary Grest while I was a postdoc at Clemson University. I gratefully acknowledge both of them for their support and encouragement.

  1. Hand Surgeon Reporting of Tendon Rupture Following Distal Radius Volar Plating

    PubMed Central

    Monaco, Nathan A.; Dwyer, C. Liam; Ferikes, Alex J.; Lubahn, John D.

    2016-01-01

    Background: Volar plate fixation with locked screws has become the preferred treatment of displaced distal radius fractures that cannot be managed nonoperatively. This treatment, however, is not without complication. The purpose of this study was to determine what percentage of hand surgeons, over a 12-month period, have experienced a tendon complication when using volar plates for the treatment of distal radius fractures. Methods: A total of 3022 hand surgeons were e-mailed a link to an online questionnaire regarding their observation and treatment of tendon injuries associated with volar plating of distal radius fractures. Responses were reported using descriptive statistics. Results: Of the 596 (20%) respondents, 199 (33%) surgeons reported encountering at least one flexor tendon injury after distal radius volar plating over the past year of practice. The flexor pollicis longus was the most commonly reported tendon injury (254, 75%). Palmaris longus grafting (118, 37%) and tendon transfer (114, 36%) were the most often reported treatments following this complication. A total of 216 respondents (36%) also encountered 324 cases of extensor tendon rupture after volar plating of distal radius fractures, with tendon transfer (88%) being the preferred treatment option. Conclusions: Both flexor and extensor tendon ruptures can be seen after volar plating of distal radius fractures. Surgeons should be aware of these complications. Critical assessment of hardware position at the time of index procedure is recommended to avoid complications. Long-term studies are needed to standardize approaches to managing tendon rupture following volar plating of distal radius fractures. PMID:27698628

  2. The value of radius bone in prediction of sex and height in the Iranian population.

    PubMed

    Akhlaghi, Mitra; Sheikhazadi, Ardeshir; Ebrahimnia, Atusa; Hedayati, Mahrang; Nazparvar, Bashir; Saberi Anary, Seyed Hosein

    2012-05-01

    Measurement of anthropometric parameters of long bones can be applied in sex determination and height prediction. The aim of this study was to investigate the value of length of the radius in forensic identification. Cross-sectional analysis of anthropometric parameters of the radius was done by Legal Medicine Organization of Tehran, Iran studying fresh cadavers of Iranian population during 2009 and 2010. This study surveyed length of radius of 106 fresh Iranian cadavers, 61 men and 45 women, in the age range of 10-85 years old. The study showed that genders can be distinguished using the length of radius with a sensitivity of 83% and specificity of 96%. Using the regression test, there was significant relation between the height of persons and the length of radius bone. The equations were obtained to estimate the height of the individuals on the basis of radius bone length in different age groups, with an exception in females of 40-64 Years old. In the cases of fresh cadavers, by using the length of radius, we could be able to determine the length of height and gender with high confidence. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  3. COUPLED EVOLUTION WITH TIDES OF THE RADIUS AND ORBIT OF TRANSITING GIANT PLANETS: GENERAL RESULTS

    SciTech Connect

    Ibgui, Laurent; Burrows, Adam E-mail: burrows@astro.princeton.edu

    2009-08-01

    Some transiting extrasolar giant planets (EGPs) have measured radii larger than predicted by the standard theory. In this paper, we explore the possibility that an earlier episode of tidal heating can explain such radius anomalies and apply the formalism we develop to HD 209458b as an example. We find that for strong enough tides the planet's radius can undergo a transient phase of inflation that temporarily interrupts canonical, monotonic shrinking due to radiative losses. Importantly, an earlier episode of tidal heating can result in a planet with an inflated radius, even though its orbit has nearly circularized. Moreover, we confirm that at late times, and under some circumstances, by raising tides on the star itself a planet can spiral into its host. We note that a 3x to 10x solar planet atmospheric opacity with no tidal heating is sufficient to explain the observed radius of HD 209458b. However, our model demonstrates that with an earlier phase of episodic tidal heating, we can fit the observed radius of HD 209458b even with lower (solar) atmospheric opacities. This work demonstrates that, if a planet is left with an appreciable eccentricity after early inward migration and/or dynamical interaction, coupling radius and orbit evolution in a consistent fashion that includes tidal heating, stellar irradiation, and detailed model atmospheres might offer a generic solution to the inflated radius puzzle for transiting EGPs such as WASP-12b, TrES-4, and WASP-6b.

  4. Ionic liquids behave as dilute electrolyte solutions

    PubMed Central

    Gebbie, Matthew A.; Valtiner, Markus; Banquy, Xavier; Fox, Eric T.; Henderson, Wesley A.; Israelachvili, Jacob N.

    2013-01-01

    We combine direct surface force measurements with thermodynamic arguments to demonstrate that pure ionic liquids are expected to behave as dilute weak electrolyte solutions, with typical effective dissociated ion concentrations of less than 0.1% at room temperature. We performed equilibrium force–distance measurements across the common ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) using a surface forces apparatus with in situ electrochemical control and quantitatively modeled these measurements using the van der Waals and electrostatic double-layer forces of the Derjaguin–Landau–Verwey–Overbeek theory with an additive repulsive steric (entropic) ion–surface binding force. Our results indicate that ionic liquids screen charged surfaces through the formation of both bound (Stern) and diffuse electric double layers, where the diffuse double layer is comprised of effectively dissociated ionic liquid ions. Additionally, we used the energetics of thermally dissociating ions in a dielectric medium to quantitatively predict the equilibrium for the effective dissociation reaction of [C4mim][NTf2] ions, in excellent agreement with the measured Debye length. Our results clearly demonstrate that, outside of the bound double layer, most of the ions in [C4mim][NTf2] are not effectively dissociated and thus do not contribute to electrostatic screening. We also provide a general, molecular-scale framework for designing ionic liquids with significantly increased dissociated charge densities via judiciously balancing ion pair interactions with bulk dielectric properties. Our results clear up several inconsistencies that have hampered scientific progress in this important area and guide the rational design of unique, high–free-ion density ionic liquids and ionic liquid blends. PMID:23716690

  5. Ionic liquids behave as dilute electrolyte solutions.

    PubMed

    Gebbie, Matthew A; Valtiner, Markus; Banquy, Xavier; Fox, Eric T; Henderson, Wesley A; Israelachvili, Jacob N

    2013-06-11

    We combine direct surface force measurements with thermodynamic arguments to demonstrate that pure ionic liquids are expected to behave as dilute weak electrolyte solutions, with typical effective dissociated ion concentrations of less than 0.1% at room temperature. We performed equilibrium force-distance measurements across the common ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) using a surface forces apparatus with in situ electrochemical control and quantitatively modeled these measurements using the van der Waals and electrostatic double-layer forces of the Derjaguin-Landau-Verwey-Overbeek theory with an additive repulsive steric (entropic) ion-surface binding force. Our results indicate that ionic liquids screen charged surfaces through the formation of both bound (Stern) and diffuse electric double layers, where the diffuse double layer is comprised of effectively dissociated ionic liquid ions. Additionally, we used the energetics of thermally dissociating ions in a dielectric medium to quantitatively predict the equilibrium for the effective dissociation reaction of [C4mim][NTf2] ions, in excellent agreement with the measured Debye length. Our results clearly demonstrate that, outside of the bound double layer, most of the ions in [C4mim][NTf2] are not effectively dissociated and thus do not contribute to electrostatic screening. We also provide a general, molecular-scale framework for designing ionic liquids with significantly increased dissociated charge densities via judiciously balancing ion pair interactions with bulk dielectric properties. Our results clear up several inconsistencies that have hampered scientific progress in this important area and guide the rational design of unique, high-free-ion density ionic liquids and ionic liquid blends.

  6. Ionic liquid processing of cellulose.

    PubMed

    Wang, Hui; Gurau, Gabriela; Rogers, Robin D

    2012-02-21

    Utilization of natural polymers has attracted increasing attention because of the consumption and over-exploitation of non-renewable resources, such as coal and oil. The development of green processing of cellulose, the most abundant biorenewable material on Earth, is urgent from the viewpoints of both sustainability and environmental protection. The discovery of the dissolution of cellulose in ionic liquids (ILs, salts which melt below 100 °C) provides new opportunities for the processing of this biopolymer, however, many fundamental and practical questions need to be answered in order to determine if this will ultimately be a green or sustainable strategy. In this critical review, the open fundamental questions regarding the interactions of cellulose with both the IL cations and anions in the dissolution process are discussed. Investigations have shown that the interactions between the anion and cellulose play an important role in the solvation of cellulose, however, opinions on the role of the cation are conflicting. Some researchers have concluded that the cations are hydrogen bonding to this biopolymer, while others suggest they are not. Our review of the available data has led us to urge the use of more chemical units of solubility, such as 'g cellulose per mole of IL' or 'mol IL per mol hydroxyl in cellulose' to provide more consistency in data reporting and more insight into the dissolution mechanism. This review will also assess the greenness and sustainability of IL processing of biomass, where it would seem that the choices of cation and anion are critical not only to the science of the dissolution, but to the ultimate 'greenness' of any process (142 references).

  7. Ionic liquids--an overview.

    PubMed

    Jenkins, Harry Donald Brooke

    2011-01-01

    A virtually unprecedented exponential burst of activity resulted following the publication, in 1998, of an article by Michael Freeman (Freemantle, M. Chemical & Engineering News, 1998, March 30, 32), which speculated on the role and contribution that ionic liquids (ILs) might make in the future on the development of clean technology. Up until that time only a handful of researchers were routinely engaged in the study of ILs but frenzied activity followed that continues until the present day. Scientists from all disciplines related to Chemistry have now embarked on studies, including theoreticians who are immersed in the aim of improving the "designer role" so that they can tailor ILs to deliver specified properties. This article, whilst not in any sense attempting to be exhaustive, highlights the main features which characterise ILs, presenting these in a form readily assimilated by newcomers to this area of research. An extensive glossary is featured in this article as well as a chronological list which charts the major areas of development. What follows consists of a number of sections briefly describing the role of lLs as solvents, hypergolic fuels, their use in some electrochemical devices such as solar cells and lithium batteries and their use in polymerisation reactions, followed by a concise summary of some of the other roles that they are capable of playing. The role of empirical, volume-based thermodynamics procedures, as well as large scale computational studies on ILs is also highlighted. These developments which are described are remarkable in that they have been achieved in less than a decade and a half although knowledge of these materials has existed for much longer.

  8. Green Imidazolium Ionics-From Truly Sustainable Reagents to Highly Functional Ionic Liquids.

    PubMed

    Tröger-Müller, Steffen; Brandt, Jessica; Antonietti, Markus; Liedel, Clemens

    2017-09-04

    We report the synthesis of task-specific imidazolium ionic compounds and ionic liquids with key functionalities of organic molecules from electro-, polymer-, and coordination chemistry. Such products are highly functional and potentially suitable for technology applications even though they are formed without elaborate reactions and from cheap and potentially green reagents. We further demonstrate the versatility of the used synthetic approach by introducing different functional and green counterions to the formed ionic liquids directly during the synthesis or after metathesis reactions. The influence of different cation structures and different anions on the thermal and electrochemical properties of the resulting ionic liquids is discussed. Our goal is to make progress towards economically competitive and sustainable task-specific ionic liquids. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Anatomical variations of the proximal radius and their effects on osteosynthesis.

    PubMed

    Giannicola, Giuseppe; Manauzzi, Erica; Sacchetti, Federico M; Greco, Alessandro; Bullitta, Gianluca; Vestri, Annarita; Cinotti, Gianluca

    2012-05-01

    In fractures of the radial head and neck requiring open reduction and internal fixation, osteosynthesis may be safely applied in a limited zone. We conducted a morphometric study of the proximal radius at the level of the safe zone to identify different morphologic types of this anatomical region. We analyzed 44 dried cadaveric radii. We measured the whole length of the radius, the length of the neck and head, and the minimum and maximum diameter of the radial head. The morphologic aspect of the neck-head curvature of the safe zone was evaluated qualitatively and quantitatively. The proximal radius at the level of the safe zone exhibited different radii of bending. In particular, we identified a morphologic type A, which showed a flat profile (25% of cases), morphologic types B and C, which showed a low concave curvature (64%), and a marked concave curvature (11%), respectively, of the safe zone. The profile of the proximal radius in the safe zone shows substantial morphologic variations that should be taken into account when operating on fractures of the proximal radius, to avoid malunions, pain, and stiffness of the elbow joint. A preoperative radiograph of the contralateral uninjured radius may be helpful in selecting the most appropriate internal fixation device to reconstruct the proximal radius after comminuted fractures. Knowledge of the proper bending radius of the safe zone allows the surgeon to select the most appropriate plate, and to achieve good fracture reduction and anatomical restoration of the proximal radius. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  10. Replicating a Colles fracture in an excised radius: revisiting testing protocols.

    PubMed

    Wagner, David W; Lindsey, Derek P; Beaupre, Gary S

    2012-04-05

    A distal radius fracture in middle-age and older adults is often considered a sentinel indicator of osteoporosis. Mechanical testing of cadaveric specimens is often used to quantify bone strength and develop insight for relating in-vivo measures to fracture force. Mechanical testing protocols using an intact forearm have been successful at replicating a Colles fracture, however, excised isolated radius protocols based on the intact forearm testing protocol have not been as successful. One protocol originally designed to replicate the physiological condition of a fall on an outstretched hand was reproduced in our laboratory, yet surprisingly the produced distal radius fracture patterns were not consistent among specimens nor was dorsal angulation of the distal fragment that is characteristic of a Colles fracture observed. The purpose of this study was to perform a mechanics-based analysis of the excised radius loading protocol in order to quantify the imposed and internal forces on the radius. An idealized beam model of the excised radius revealed that in the area of the distal radius where Colles fractures occur, 99.99% of the maximum strain on the bone outer surface was the result of pure compressive loading. This loading condition is in direct contrast to the accepted mechanics of a Colles fracture, which is characterized as a metaphyseal bending fracture with the volar cortex failing due to tensile stresses and the dorsal cortex exhibiting compression and comminution. The results suggest that additional research, particularly related to overcoming the difficulties of reliably supporting and applying a force to the distal end of the radius, is necessary for clinical fracture patterns to be reliably reproduced with an excised radius mechanical testing protocol.

  11. Mass-Radius Relationships for Low-Mass Planets: From Iron Planets to Water Planets

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2007-01-01

    Transit observations, and radial velocity measurements, have begun to populate the mass radius diagram for extrasolar planets; fubture astrometric measurements and direct images promise more mass and radius information. Clearly, the bulk density of a planet indicates something about a planet s composition--but what? I will attempt to answer this question in general for low-mass planets (radius relationship: an expansion whose first term is M approx. R(sup 3).

  12. Effect of microstructure and notch root radius on fracture toughness of an aluminum metal matrix composite

    NASA Technical Reports Server (NTRS)

    Manoharan, M.; Lewandowski, J. J.

    1989-01-01

    Recent results on the effects of matrix aging condition (matrix temper) and notch root radius on the measured fracture toughness of a SiC particulate reinforced aluminum alloy are reviewed. Stress intensity factors at catastrophic fracture were obtained for both underaged and overaged composites reveal. The linear relation found between apparent fracture toughness and the square root of the notch root radius implies a linear dependence of the crack opening displacement on the notch root radius. The results suggest a strain controlled fracture process, and indicate that there are differences in the fracture micromechanisms of the two aging conditions.

  13. The Effect of Osteoporosis on Healing of Distal Radius Fragility Fractures.

    PubMed

    Tulipan, Jacob; Jones, Christopher M; Ilyas, Asif M

    2015-10-01

    Although the decision for operative versus nonoperative treatment of distal radius fractures remains subjective and is performed on a case-by-case basis, evaluation and treatment of patients with concomitant osteoporosis requires understanding of the behavior of this injury as a distinct subset of distal radius fractures. Age, infirmity, and osteoporosis affect every aspect of the fracture. Understanding what makes these fractures unique assists surgeons in more effective and efficient treatment. The authors present the current understanding of osteoporotic fragility fractures of the distal radius, focusing on epidemiology, biomechanics of bone healing, and its implication on strategies for management.

  14. Posterior interosseous nerve palsy caused by parosteal lipoma of proximal radius.

    PubMed

    Nishida, J; Shimamura, T; Ehara, S; Shiraishi, H; Sato, T; Abe, M

    1998-07-01

    Lipomas are common benign soft tissue tumors which tend to be indolent, and symptoms caused by nerve compression are unusual. However, a parosteal lipoma, occurring adjacent to the proximal radius may easily cause paralysis of the posterior interosseous nerve because of a specific anatomical relationship of these structures in that area. Two cases of parosteal lipoma of the proximal radius causing paralysis of the posterior interosseous nerve are reported. CT and MR imaging demonstrate the characteristic fatty mass around the radius and are specific in making the diagnosis. Surgical excision should be promptly performed to ensure optimal recovery from the nerve paralysis.

  15. The Evolution of Distal Radius Fracture Management – A Historical Treatise

    PubMed Central

    Diaz-Garcia, Rafael J.; Chung, Kevin C.

    2012-01-01

    Distal radius fractures have been a common affliction for millennia, but their treatment is a more recent development as a result of human erudition. While immobilization has served as the only available treatment for most of our history, many advances have been made in the management of distal radius fractures over the last century as the field of orthopedics has grown. Yet, the topic remains hotly contested in the literature, and research continues to focus upon it given the frequency of the injury. In this article, we chronicle the evolution of distal radius fracture treatment in hopes of providing context for the future that lies ahead. PMID:22554653

  16. Mass-Radius Relationships for Low-Mass Planets: From Iron Planets to Water Planets

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2007-01-01

    Transit observations, and radial velocity measurements, have begun to populate the mass radius diagram for extrasolar planets; fubture astrometric measurements and direct images promise more mass and radius information. Clearly, the bulk density of a planet indicates something about a planet s composition--but what? I will attempt to answer this question in general for low-mass planets (radius relationship: an expansion whose first term is M approx. R(sup 3).

  17. Use of High-Speed X ray and Video to Analyze Distal Radius Fracture Pathomechanics.

    PubMed

    Gutowski, Christina; Darvish, Kurosh; Liss, Frederic E; Ilyas, Asif M; Jones, Christopher M

    2015-10-01

    The purpose of this study is to investigate the failure sequence of the distal radius during a simulated fall onto an outstretched hand using cadaver forearms and high-speed X ray and video systems. This apparatus records the beginning and propagation of bony failure, ultimately resulting in distal radius or forearm fracture. The effects of 3 different wrist guard designs are investigated using this system. Serving as a proof-of-concept analysis, this study supports this imaging technique to be used in larger studies of orthopedic trauma and protective devices and specifically for distal radius fractures.

  18. Radius of the sun from observations of the total solar eclipse of July 31, 1981

    NASA Astrophysics Data System (ADS)

    Akimov, L. A.; Belkina, I. L.; Dyatel, N. P.; Marchenko, G. P.

    1993-06-01

    Moments of the local contacts at 24 points on E and W solar limbs are determined from the July 31, 1981 solar eclipse cinematographic observations in the continuum. The r.m.s. value of the solar radius, averaged over limb regions with different activity, is rs = 959.97 +/- 0.04 arcsec. The solar radius estimates made separately for limb active regions and for undisturbed ones demonstrated the significance of the active region effects on the measured solar radius (up to 0.14 arcsec).

  19. Radius of the Sun from observations of the total solar eclipse of 31 July 1981.

    NASA Astrophysics Data System (ADS)

    Akimov, L. A.; Belkina, I. L.; Dyatel, N. P.; Marchenko, G. P.

    The moments of local contacts of 24 points on the east and west solar limbs are determined from the cinematographic solar continuum observations during the 31 July 1981 eclipse. The value of the solar radius averaged over limb regions with different activity was found by the least-squares method - rs = 959.97±0.04″ The solar radius estimates made separately for active and quiet limb regions reveal that the effect of active regions on the measured radius value is significant and may be as much as 0.14″

  20. Effect of microstructure and notch root radius on fracture toughness of an aluminum metal matrix composite

    NASA Technical Reports Server (NTRS)

    Manoharan, M.; Lewandowski, J. J.

    1989-01-01

    Recent results on the effects of matrix aging condition (matrix temper) and notch root radius on the measured fracture toughness of a SiC particulate reinforced aluminum alloy are reviewed. Stress intensity factors at catastrophic fracture were obtained for both underaged and overaged composites reveal. The linear relation found between apparent fracture toughness and the square root of the notch root radius implies a linear dependence of the crack opening displacement on the notch root radius. The results suggest a strain controlled fracture process, and indicate that there are differences in the fracture micromechanisms of the two aging conditions.

  1. Direct deflection radius measurement of flexible PET substrates by using an optical interferometry.

    PubMed

    Hsu, Jiong-Shiun; Li, Po-Wei

    2015-06-10

    The deflection radius is essential in determining residual stress estimations in flexible electronics. However, the literature provides only indirect methods for obtaining a deflection radius. In this study, we present a measurement methodology for directly measuring the deflection radius of a polyethylene terephthalate (PET) substrate (a popular substrate of flexible electronics) by using an optical interferometer. A Twyman-Green optical interferometer was established and phase-shifting technology was used to increase the measurement resolution. Five PET substrates with known deflection radii were prepared to verify the measurement precision of the proposed measurement methodology. The results revealed that the error variance of our proposed measurement methodology is smaller than 3.5%.

  2. Finite Larmor radius stabilization of diffuse profile high-beta stellarators

    NASA Astrophysics Data System (ADS)

    Schmidt, Michael J.; Miller, Guthrie

    1981-12-01

    Finite Larmor radius effects are incorporated into near theta pinch magnetohydrodynamic theory following the method of Pearlstein and Freidberg. By a straightforward solution of the eigenvalue problem with finite Larmor radius effects included, the stability of various diffuse profile configurations has been investigated. The results differ qualitatively, as well as quantitatively, from sharp boundary theory, and it is not true, in general, that the stabilizing effect is absent for m = 1. It is found that fat plasmas can be completely stabilized by finite Larmor radius effects.

  3. Water Contaminant Mitigation in Ionic Liquid Propellant

    NASA Technical Reports Server (NTRS)

    Conroy, David; Ziemer, John

    2009-01-01

    Appropriate system and operational requirements are needed in order to ensure mission success without unnecessary cost. Purity requirements applied to thruster propellants may flow down to materials and operations as well as the propellant preparation itself. Colloid electrospray thrusters function by applying a large potential to a room temperature liquid propellant (such as an ionic liquid), inducing formation of a Taylor cone. Ions and droplets are ejected from the Taylor cone and accelerated through a strong electric field. Electrospray thrusters are highly efficient, precise, scaleable, and demonstrate low thrust noise. Ionic liquid propellants have excellent properties for use as electrospray propellants, but can be hampered by impurities, owing to their solvent capabilities. Of foremost concern is the water content, which can result from exposure to atmosphere. Even hydrophobic ionic liquids have been shown to absorb water from the air. In order to mitigate the risks of bubble formation in feed systems caused by water content of the ionic liquid propellant, physical properties of the ionic liquid EMI-Im are analyzed. The effects of surface tension, material wetting, physisorption, and geometric details of the flow manifold and electrospray emitters are explored. Results are compared to laboratory test data.

  4. Water Contaminant Mitigation in Ionic Liquid Propellant

    NASA Technical Reports Server (NTRS)

    Conroy, David; Ziemer, John

    2009-01-01

    Appropriate system and operational requirements are needed in order to ensure mission success without unnecessary cost. Purity requirements applied to thruster propellants may flow down to materials and operations as well as the propellant preparation itself. Colloid electrospray thrusters function by applying a large potential to a room temperature liquid propellant (such as an ionic liquid), inducing formation of a Taylor cone. Ions and droplets are ejected from the Taylor cone and accelerated through a strong electric field. Electrospray thrusters are highly efficient, precise, scaleable, and demonstrate low thrust noise. Ionic liquid propellants have excellent properties for use as electrospray propellants, but can be hampered by impurities, owing to their solvent capabilities. Of foremost concern is the water content, which can result from exposure to atmosphere. Even hydrophobic ionic liquids have been shown to absorb water from the air. In order to mitigate the risks of bubble formation in feed systems caused by water content of the ionic liquid propellant, physical properties of the ionic liquid EMI-Im are analyzed. The effects of surface tension, material wetting, physisorption, and geometric details of the flow manifold and electrospray emitters are explored. Results are compared to laboratory test data.

  5. Electroosmotic flow hysteresis for dissimilar ionic solutions

    PubMed Central

    Lim, An Eng; Lam, Yee Cheong

    2015-01-01

    Electroosmotic flow (EOF) with two or more fluids is commonly encountered in various microfluidics applications. However, no investigation has hitherto been conducted to investigate the hysteretic or flow direction-dependent behavior during the displacement flow of solutions with dissimilar ionic species. In this investigation, electroosmotic displacement flow involving dissimilar ionic solutions was studied experimentally through a current monitoring method and numerically through finite element simulations. The flow hysteresis can be characterized by the turning and displacement times; turning time refers to the abrupt gradient change of current-time curve while displacement time is the time for one solution to completely displace the other solution. Both experimental and simulation results illustrate that the turning and displacement times for a particular solution pair can be directional-dependent, indicating that the flow conditions in the microchannel are not the same in the two different flow directions. The mechanics of EOF hysteresis was elucidated through the theoretical model which includes the ionic mobility of each species, a major governing parameter. Two distinct mechanics have been identified as the causes for the EOF hysteresis involving dissimilar ionic solutions: the widening/sharpening effect of interfacial region between the two solutions and the difference in ion concentration distributions (and thus average zeta potentials) in different flow directions. The outcome of this investigation contributes to the fundamental understanding of flow behavior in microfluidic systems involving solution pair with dissimilar ionic species. PMID:25945139

  6. Counterion-induced swelling of ionic microgels

    NASA Astrophysics Data System (ADS)

    Denton, Alan R.; Tang, Qiyun

    2016-10-01

    Ionic microgel particles, when dispersed in a solvent, swell to equilibrium sizes that are governed by a balance between electrostatic and elastic forces. Tuning of particle size by varying external stimuli, such as pH, salt concentration, and temperature, has relevance for drug delivery, microfluidics, and filtration. To model swelling of ionic microgels, we derive a statistical mechanical theorem, which proves exact within the cell model, for the electrostatic contribution to the osmotic pressure inside a permeable colloidal macroion. Applying the theorem, we demonstrate how the distribution of counterions within an ionic microgel determines the internal osmotic pressure. By combining the electrostatic pressure, which we compute via both Poisson-Boltzmann theory and molecular dynamics simulation, with the elastic pressure, modeled via the Flory-Rehner theory of swollen polymer networks, we show how deswelling of ionic microgels with increasing concentration of particles can result from a redistribution of counterions that reduces electrostatic pressure. A linearized approximation for the electrostatic pressure, which proves remarkably accurate, provides physical insight and greatly eases numerical calculations for practical applications. Comparing with experiments, we explain why soft particles in deionized suspensions deswell upon increasing concentration and why this effect may be suppressed at higher ionic strength. The failure of the uniform ideal-gas approximation to adequately account for counterion-induced deswelling below close packing of microgels is attributed to neglect of spatial variation of the counterion density profile and the electrostatic pressure of incompletely neutralized macroions.

  7. Ionic liquids as active pharmaceutical ingredients.

    PubMed

    Ferraz, Ricardo; Branco, Luís C; Prudêncio, Cristina; Noronha, João Paulo; Petrovski, Zeljko

    2011-06-06

    Ionic liquids (ILs) are ionic compounds that possess a melting temperature below 100 °C. Their physical and chemical properties are attractive for various applications. Several organic materials that are now classified as ionic liquids were described as far back as the mid-19th century. The search for new and different ILs has led to the progressive development and application of three generations of ILs: 1) The focus of the first generation was mainly on their unique intrinsic physical and chemical properties, such as density, viscosity, conductivity, solubility, and high thermal and chemical stability. 2) The second generation of ILs offered the potential to tune some of these physical and chemical properties, allowing the formation of "task-specific ionic liquids" which can have application as lubricants, energetic materials (in the case of selective separation and extraction processes), and as more environmentally friendly (greener) reaction solvents, among others. 3) The third and most recent generation of ILs involve active pharmaceutical ingredients (API), which are being used to produce ILs with biological activity. Herein we summarize recent developments in the area of third-generation ionic liquids that are being used as APIs, with a particular focus on efforts to overcome current hurdles encountered by APIs. We also offer some innovative solutions in new medical treatment and delivery options.

  8. Optimization research of sextant fan baffle curvature radius in shell and tube heat exchanger

    NASA Astrophysics Data System (ADS)

    Jin, M.; Liu, H. J.; Wang, X. Y.

    2017-09-01

    For a high shell side pressure drop of the conventional segmental baffles in shell and tube heat exchanger, a novel sextant fan baffle was put forward. To research the influence of baffle curvature radius of the sextant fan baffled shell and tube heat exchanger (SFTHX) on the shell side pressure drop, the heat transfer coefficient and the comprehensive heat transfer performance, six different curvature radius baffles were numerically simulated and experimental studied in this paper. Based on the numerically simulation results, under the same inlet flow conditions, a better comprehensive heat transfer performance can be found in SFTHX with the baffle curvature radius of 1 D, which is higher by 0.84-6.85% more than that of the others. Moreover, the experimental investigation data of SFTHX with baffle curvature radius of 1 D indicates that the numerically simulation can well predict the flow and heat transfer characteristics with the experiment.

  9. Volar Locking Plate Breakage after Nonunion of a Distal Radius Osteotomy

    PubMed Central

    Rodríguez-Alabau, Sergi; Soldado, Francisco; Mir, Xavier

    2016-01-01

    We report a 38-year-old male with a nonunion followed by plate breakage after volar plating of a distal radius osteotomy. Volar locking plates have added a new approach to the treatment of distal radius malunions, due to a lower morbidity of the surgical approach and the strength of the final construction, allowing early mobilization and return to function. Conclusion. Plate breakage is an uncommon complication of volar locking plate fixation. To our knowledge, few cases have been described after a distal radius fracture and no case has been described after a distal radius corrective osteotomy. In the present case, plate breakage appears to have occurred as a result of a combination of multiple factors as the large corrective lengthening osteotomy, the use of demineralized bone matrix instead of bone graft, and the inappropriate fixation technique as an unfilled screw on the osteotomy site, rather than the choice of plate. PMID:28003828

  10. Reynolds Number Effects on Leading Edge Radius Variations of a Supersonic Transport at Transonic Conditions

    NASA Technical Reports Server (NTRS)

    Rivers, S. M. B.; Wahls, R. A.; Owens, L. R.

    2001-01-01

    A computational study focused on leading-edge radius effects and associated Reynolds number sensitivity for a High Speed Civil Transport configuration at transonic conditions was conducted as part of NASA's High Speed Research Program. The primary purposes were to assess the capabilities of computational fluid dynamics to predict Reynolds number effects for a range of leading-edge radius distributions on a second-generation supersonic transport configuration, and to evaluate the potential performance benefits of each at the transonic cruise condition. Five leading-edge radius distributions are described, and the potential performance benefit including the Reynolds number sensitivity for each is presented. Computational results for two leading-edge radius distributions are compared with experimental results acquired in the National Transonic Facility over a broad Reynolds number range.

  11. Method for Determining the Radius Vector for a Planet from Two Observations of Position

    ERIC Educational Resources Information Center

    Gainer, Michael Kizinski

    1977-01-01

    Presents a method for determining the approximate radius vector of a planet or asteroid from two closely separated observation positions, using mathematics suitable for lower division college students. (MLH)

  12. Open-grown crown radius of eleven bottomland hardwood species: Prediction and use in assessing stocking

    SciTech Connect

    Goelz, J.C.G.

    1996-08-01

    Equations were prepared to predict crown radius for eleven species of open-grown bottomland hardwood trees. Crown radius was predicted as a function of diameter at breast height (dbh) and as a function of dbh, total height, and crown ratio. Equations were prepared for individual species and species groups. Pecan has the largest crowns over a broad range of dbh. Eastern cottonwood has the smallest crowns for most levels of dbh. Sweetgum has relatively small crowns for trees of small dbh, but crown radius is comparable to most species at the largest dbh. The crown radius predictions may be used to calculate crown competition factor. B-lines of stocking may be calculated that represent a stand of one species as well as a mixed-species stand of any particular species proportion.

  13. Radius of Curvature of the Cornea--An Experiment for the Life-Science Physics Lab

    ERIC Educational Resources Information Center

    MacLatchy, C. S.

    1978-01-01

    Presents a quantitative laboratory experiment in geometrical optics. It involves the student in the measurement of the radius of curvature of the cornea and is based on an old method devised by Kohlrausch in 1839. (Author/GA)

  14. Radiation Power Affected by Current and Wall Radius in Water Cooled Vortex Wall-stabilized Arc

    NASA Astrophysics Data System (ADS)

    Iwao, Toru; Nakamura, Takaya; Yanagi, Kentaro; Yamamoto, Shinji

    2015-11-01

    The arc lighting to obtain the environment to evacuate, save the life, keep the safety and be comfortable are focus on. The lack of radiation intensity and color rendering is problem because of inappropriate energy balance. Some researchers have researched the arc lamp mixed with metal vapor for improvement of color rendering spectrum. The metal vapor can emit the high intense radiation. In addition, the radiation is derived from the high temperature medium. Because the arc temperature can be controlled by current and arc radius, the radiation can be controlled by the current and arc radius. This research elucidates the radiation power affected by the current and wall radius in wall-stabilized arc of water-cooled vortex type. As a result, the radiation power increases with increasing the square of current / square of wall radius because of the temperature distribution which is derived from the current density at the simulation.

  15. Radius construction and structure in the orb-web of Zilla diodia (Araneidae).

    PubMed

    Zschokke, S

    2000-10-01

    In orb-webs, the tension of the sticky spiral produces a centripetal force on the radii, resulting in an increase in tension along each radius from the centre of the web to the periphery. Zilla diodia (Walckenaer, 1802) atypical of araneids, was found to adapt the structure of its radii to this tension gradient by building radii that are double stranded at the periphery of the web and single stranded near the centre. Furthermore, the proportion of each radius that is doubled was found to be larger in the upper part of the web - where the overall tensions in the radii are known to be higher than in the lower part of the web. suggesting that the spider adjusts the proportion of each radius that is doubled to the overall tension in the radius.

  16. Method for Determining the Radius Vector for a Planet from Two Observations of Position

    ERIC Educational Resources Information Center

    Gainer, Michael Kizinski

    1977-01-01

    Presents a method for determining the approximate radius vector of a planet or asteroid from two closely separated observation positions, using mathematics suitable for lower division college students. (MLH)

  17. [Early corrective osteotomy after secondary displaced distal radius fractures in children].

    PubMed

    Boeckers, P; Gehrmann, S V; Wild, M; Schädel-Höpfner, M; Windolf, J

    2014-02-01

    Secondary fracture displacement before osseous consolidation of distal radius fractures in children occasionally leads to restricted forearm rotation. So far, there is no consistent treatment recommendation to correct this complication. We report on 5 children with an age of 8-13 years (mean age 12.3 years, 4 boys, 1 girl) with secondary displaced distal radius fractures and high functional deficits in forearm rotation (mean ROM for pro-/supination 70-0-30°) after osseous consolidation. We performed corrective osteotomies of the distal radius using a palmar approach after a mean of 38 days. Stabilisation was achieved with a fixed-angle plate system. At the final follow-up examination (mean 9 months) the forearm rotation was normal. No complications were observed. We consider corrective osteotomies of the distal radius in children with deficits of forearm rotation to be a possible strategy. Early corrective osteotomies can lead to a predictable increase of function through reestablishing normal articulation.

  18. Secondary displacement of distal radius fractures treated by bridging external fixation.

    PubMed

    Farah, N; Nassar, L; Farah, Z; Schuind, F

    2014-05-01

    Loss of reduction remains an important problem after treatment of distal radius fractures, whatever the type of bone fixation. We assessed retrospectively the rate of secondary displacement after external fixation of distal radius fractures in order to identify possible risk factors for instability. We reviewed the pre-operative and serial post-operative radiographs of a retrospective series of 35 distal radius fractures treated by bridging external fixation. When classified according to the Société Française d'Orthopédie et Traumatologie (SOFCOT) criteria, the rate of secondary displacement was 48.5%. At final follow up, the reduction was anatomical in 12% and acceptable in 83%. There was malunion in 5%. The loss of reduction concerned primarily the distal radius palmar tilt and was moderate. No correlation was found with age, gender, type of fracture, degree of initial displacement, associated ulnar fracture, or seniority of the treating surgeon.

  19. Vertex radius measurement of an off-axis parabola with a three-ball spherometer

    NASA Astrophysics Data System (ADS)

    Dominguez, Margaret Z.; Li, Jianxin; Zhou, Ping; Burge, James H.

    2016-12-01

    A spherometer is often used to precisely measure the radius of curvature of a spherical surface. It can also measure the vertex radius of a more complex surface such as an off-axis parabola (OAP). This paper provides a reliable algorithm to find the vertex radius of an OAP by solving a few equations based on the test geometry. This algorithm can also be easily expanded to any conic surface with high-order aspheric coefficients. The algorithm was verified by measuring an 8-inch diameter OAP and comparing the results with its known prescription. Results show good agreement. An example of measuring the vertex radius of a 4-m diameter OAP is also presented. In addition to this, a calculation was done to show that the coma and astigmatism are independent of the clocking of the spherometer on the optic.

  20. The optimum cut-off radius in Monte Carlo simulation of Yukawa potential point particles

    NASA Astrophysics Data System (ADS)

    Suwan, I.; Hussein, H.; Hussein, A.; Daragmeh, M.

    2017-06-01

    In this paper, infinite systems of point particles with Yukawa potential and periodic boundary conditions are simulated using Monte Carlo technique in three dimensions. Because of the short range nature of the Yukawa potential, cut-off radius rcut is considered in calculations (i.e, for each particle i, the effect of the other particles on it inside a sphere of radius rcut is taken into account). The cut-off radius used in Monte Carlo simulation affects the physical behavior of the system being simulated. A sequence of rcut values are used. When the change in the total potential energy becomes negligible, the optimum value of the cut-off radius is determined. This value is found to be independent of density and temperature in the NVT-ensemble case.

  1. Physeal growth arrest of the distal radius treated by the Ilizarov technique. Report of a case.

    PubMed

    Aston, J W; Henley, M B

    1989-07-01

    Growth arrest of the distal radius may follow a severe injury to the growth plate. When the growth of the distal radius ceases in the child, continuing ulnar growth results in radial deviation of the hand and dislocation of the distal radioulnar joint. Treatment options in such a limb-length discrepancy are resection of the physeal bony bridge, lengthening of the shaft of the radius with bone graft using the principle of the Wagner technique, resection or epiphysiodesis of the distal ulna, and lengthening through a metaphyseal corticotomy without the use of bone graft. We report a case of metaphyseal lengthening of the radius employing the Ilizarov external fixator for controlled distraction osteogenesis.

  2. Infrequent physeal wrist injury of the ulna and radius: a case report

    PubMed Central

    Rey, Eloisa Felíu; Vicente-Franqueira, Javier Roca; Trigueros, Antonio Perez

    2008-01-01

    We describe the case of a 13-year-old patient with a left wrist physeal fracture of the ulna and radius. X-Ray showed a Salter–Harris type II injury of the radius, and CT and MRI identified the following: type II epiphysiolysis of the radius with a metaphyseal wedge and type IV fracture of the ulna, with interposition in the focus of the fracture of the extensor carpi ulnaris tendon, as well as a tear in the central area of the triangular fibrocartilage complex. All these injuries were checked intraoperatively during open reduction. We believe that this clinical case illustrates the importance of carefully assessing physeal wrist injuries when they occur, especially in those cases involving the ulna and the radius. Diagnostic methods such as CT and MRI scans are indispensable for through evaluation and treatment of the injury. PMID:19034390

  3. Reverberation measurements of the inner radius of the dust torus in 17 Seyfert galaxies

    SciTech Connect

    Koshida, Shintaro; Minezaki, Takeo; Yoshii, Yuzuru; Sakata, Yu; Sugawara, Shota; Kobayashi, Yukiyasu; Suganuma, Masahiro; Enya, Keigo; Tomita, Hiroyuki; Aoki, Tsutomu; Peterson, Bruce A. E-mail: minezaki@ioa.s.u-tokyo.ac.jp

    2014-06-20

    We present the results of a dust reverberation survey for 17 nearby Seyfert 1 galaxies, which provides the largest homogeneous data collection for the radius of the innermost dust torus. A delayed response of the K-band light curve after the V-band light curve was found for all targets, and 49 measurements of lag times between the flux variation of the dust emission in the K band and that of the optical continuum emission in the V band were obtained by the cross-correlation function analysis and also by an alternative method for estimating the maximum likelihood lag. The lag times strongly correlated with the optical luminosity in the luminosity range of M{sub V} = –16 to –22 mag, and the regression analysis was performed to obtain the correlation log Δt (days) = –2.11 – 0.2 M{sub V} assuming Δt∝L {sup 0.5}, which was theoretically expected. We discuss the possible origins of the intrinsic scatter of the dust lag-luminosity correlation, which was estimated to be approximately 0.13 dex, and we find that the difference of internal extinction and delayed response of changes in lag times to the flux variations could have partly contributed to intrinsic scatter. However, we could not detect any systematic change of the correlation with the subclass of the Seyfert type or the Eddington ratio. Finally, we compare the dust reverberation radius with the near-infrared interferometric radius of the dust torus and the reverberation radius of broad Balmer emission lines. The interferometric radius in the K band was found to be systematically larger than the dust reverberation radius in the same band by the about a factor of two, which could be interpreted by the difference between the flux-weighted radius and response-weighted radius of the innermost dust torus. The reverberation radius of the broad Balmer emission lines was found to be systematically smaller than the dust reverberation radius by about a factor of four to five, which strongly supports the unified

  4. Key Developments in Ionic Liquid Crystals.

    PubMed

    Alvarez Fernandez, Alexandra; Kouwer, Paul H J

    2016-05-16

    Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a molecular perspective. What are the important molecular parameters that determine the phase behavior? How should they be introduced into the molecules? Finally, which other tools does one have to realize specific properties in the material?

  5. Key Developments in Ionic Liquid Crystals

    PubMed Central

    Alvarez Fernandez, Alexandra; Kouwer, Paul H. J.

    2016-01-01

    Ionic liquid crystals are materials that combine the classes of liquid crystals and ionic liquids. The first one is based on the multi-billion-dollar flat panel display industry, whilst the latter quickly developed in the past decades into a family of highly-tunable non-volatile solvents. The combination yields materials with a unique set of properties, but also with many challenges ahead. In this review, we provide an overview of the key concepts in ionic liquid crystals, particularly from a molecular perspective. What are the important molecular parameters that determine the phase behavior? How should they be introduced into the molecules? Finally, which other tools does one have to realize specific properties in the material? PMID:27196890

  6. Enzyme activity in dialkyl phosphate ionic liquids

    SciTech Connect

    Thomas, M.F.; Dunn, J.; Li, L.-L.; Handley-Pendleton, J. M.; van der lelie, D.; Wishart, J. F.

    2011-12-01

    The activity of four metagenomic enzymes and an enzyme cloned from the straw mushroom, Volvariellavolvacea were studied in the following ionic liquids, 1,3-dimethylimidazolium dimethyl phosphate, [mmim][dmp], 1-ethyl-3-methylimidazolium dimethyl phosphate, [emim][dmp], 1-ethyl-3-methylimidazolium diethyl phosphate, [emim][dep] and 1-ethyl-3-methylimidazolium acetate, [emim][OAc]. Activity was determined by analyzing the hydrolysis of para-nitrobenzene carbohydrate derivatives. In general, the enzymes were most active in the dimethyl phosphate ionic liquids, followed by acetate. Generally speaking, activity decreased sharply for concentrations of [emim][dep] above 10% v/v, while the other ionic liquids showed less impact on activity up to 20% v/v.

  7. Individual SWCNT based ionic field effect transistor

    NASA Astrophysics Data System (ADS)

    Pang, Pei; He, Jin; Park, Jae Hyun; Krstic, Predrag; Lindsay, Stuart

    2011-03-01

    Here we report that the ionic current through a single-walled carbon nanotube (SWCNT) can be effectively gated by a perpendicular electrical field from a top gate electrode, working as ionic field effect transistor. Both our experiment and simulation confirms that the electroosmotic current (EOF) is the main component in the ionic current through the SWCNT and is responsible for the gating effect. We also studied the gating efficiency as a function of solution concentration and pH and demonstrated that the device can work effectively in the physiological relevant condition. This work opens the door to use CNT based nanofluidics for ion and molecule manipulation. This work was supported by the DNA Sequencing Technology Program of the National Human Genome Research Institute (1RC2HG005625-01, 1R21HG004770-01), Arizona Technology Enterprises and the Biodesign Institute.

  8. Static dielectric properties of dense ionic fluids.

    PubMed

    Zarubin, Grigory; Bier, Markus

    2015-05-14

    The static dielectric properties of dense ionic fluids, e.g., room temperature ionic liquids (RTILs) and inorganic fused salts, are investigated on different length scales by means of grandcanonical Monte Carlo simulations. A generally applicable scheme is developed which allows one to approximately decompose the electric susceptibility of dense ionic fluids into the orientation and the distortion polarization contribution. It is shown that at long range, the well-known plasma-like perfect screening behavior occurs, which corresponds to a diverging distortion susceptibility, whereas at short range, orientation polarization dominates, which coincides with that of a dipolar fluid of attached cation-anion pairs. This observation suggests that the recently debated interpretation of RTILs as dilute electrolyte solutions might not be simply a yes-no-question but it might depend on the considered length scale.

  9. Understanding the polarity of ionic liquids.

    PubMed

    Ab Rani, M A; Brant, A; Crowhurst, L; Dolan, A; Lui, M; Hassan, N H; Hallett, J P; Hunt, P A; Niedermeyer, H; Perez-Arlandis, J M; Schrems, M; Welton, T; Wilding, R

    2011-10-06

    The polarities of a wide range of ionic liquids have been determined using the Kamlet-Taft empirical polarity scales α, β and π*, with the dye set Reichardt's Dye, N,N-diethyl-4-nitroaniline and 4-nitroaniline. These have been compared to measurements of these parameters with different dye sets and to different polarity scales. The results emphasise the importance of recognising the role that the nature of the solute plays in determining these scales. It is particularly noted that polarity scales based upon charged solutes can give very different values for the polarity of ionic liquids compared to those based upon neutral probes. Finally, the effects of commonplace impurities in ionic liquids are reported.

  10. Short range effective potentials for ionic fluids

    NASA Astrophysics Data System (ADS)

    Clarke, J. H. R.; Smith, W.; Woodcock, L. V.

    1986-02-01

    It is shown that the structure of a simple ionic liquid, potassium chloride, can be reproduced in computer simulations using short range effective pair (SHREP) potentials of a simple form. Aside from the balance between like and unlike particle interactions, the important parameters determining the structure are the depth ɛ and the position r0 of the unlike particle pair energy minimum. The results demonstrate that the long range ordering characteristic of ionic liquids is not a consequence of the long range of Coulomb interactions. It is further shown that first order perturbation theory can be used accurately to calculate the thermodynamic properties of an ionic liquid from a corresponding reference liquid generated using a SHREP potential. These results can be generalized to explain deviations from the Reiss-Mayer-Katz corresponding states law for alkali halides and suggest an alternative scheme, effective depth reduction (EDR), based on values of ɛ for the gas phase ion pairs.

  11. Low severity coal conversion by ionic hydrogenation

    SciTech Connect

    Larsen, J.W.; Maioriello, J.; Cheng, J.C.

    1990-08-17

    The work accomplished in this project will be reported in two parts. Part one will focus on the development of catalytic ionic hydrogenation reactions utilizing a transition metal-H{sub 2} complex as the hydride donor and BF{sub 3}:H{sub 2}O as proton donor. This part reports the results of prelimiary work leading to the development of a new catalytic ionic hydrogenation system (MeCN){sub 2}PtCl{sub 2}/H{sub 2}/BF{sub 3}: H{sub 2}O. The results from some of this work have been published and the paper is included as the appendix. The second part focuses on the newly developed catalytic and other well characterized ionic hydrogenation reactions applied to lignites (Beulah-Zap), sub-bitumiuous (Wyodak), and bituminous coals (Pittsburgh {number sign}8). 19 refs., 10 tabs.

  12. INDICATIONS OF R-MODE OSCILLATIONS IN SOHO/MDI SOLAR RADIUS MEASUREMENTS

    SciTech Connect

    Sturrock, P. A.; Bush, R.; Gough, D. O.; Scargle, J. D.

    2015-05-01

    Analysis of solar radius measurements acquired by the Michelson Doppler Imager on the Solar and Heliospheric Observatory spacecraft supports previously reported evidence of solar internal r-mode oscillations in Mt Wilson radius data and in {sup 90}Sr beta-decay data. The frequencies of these oscillations are compatible with oscillations in a putative inner tachocline that separates a slowly rotating core from the radiative envelope.

  13. Indications of R-mode Oscillations in SOHO/MDI Solar Radius Measurements

    NASA Astrophysics Data System (ADS)

    Sturrock, P. A.; Bush, R.; Gough, D. O.; Scargle, J. D.

    2015-05-01

    Analysis of solar radius measurements acquired by the Michelson Doppler Imager on the Solar and Heliospheric Observatory spacecraft supports previously reported evidence of solar internal r-mode oscillations in Mt Wilson radius data and in 90Sr beta-decay data. The frequencies of these oscillations are compatible with oscillations in a putative inner tachocline that separates a slowly rotating core from the radiative envelope.

  14. Radius surgical system and conventional laparoscopic instruments in abdominal surgery: application, learning curve and ergonomy.

    PubMed

    Di Lorenzo, N; Camperchioli, I; Gaspari, A L

    2007-12-01

    We illustrate our experience with a new class of instruments, the mechanical manipulators (MM), whose main features are an improved mobility, and ergonomy and a modular structure. A specific MM, the Radius Surgical System (RADIUS), has been used both for educational purposes as well as in clinical studies, demonstrating that it can represent an efficient tool to support surgeons performing surgical complex procedures, with a short learning curve for the postural attitude.

  15. A high speed capacitance based system for gauging turbomachinery blading radius during the tip grind process

    NASA Astrophysics Data System (ADS)

    Sheard, A. G.; Westerman, G. C.; Killeen, B.; Fitzpatrick, M.

    1992-06-01

    A new method for measuring the rotor radius over individual blades is presented. This measurement method employs a capacitance based clearance measurement system that enables rotor radius to be measured over each blade while spinning fast enough to ensure that the blades are centrifugally loaded into their true working position. The results of an experimental program, employing a fully bladed compressor disk undertaken to ascertain system performance, are presented.

  16. Distal radius fracture after Sauvé-Kapandji procedure in a rheumatoid arthritis patient.

    PubMed

    Ochi, Kensuke; Horiuchi, Yukio; Matsumura, Takashi; Nakamura, Mitsukazu; Takei, Terue; Yabe, Hiroki

    2012-04-01

    We report a case of distal radius fracture after a Sauvé-Kapandji procedure combined with synovectomy and tendon transfer in a rheumatoid arthritis patient. This case shared several unusual features that were also seen in a previously reported case. Based on these features, we discuss favorable surgical treatment for the rheumatoid wrist with extensor tendon rupture, and also the optimal treatment for distal radius fracture after such procedures.

  17. Influence of absorbed energy distribution along beam radius on ignition threshold of condensed explosives

    NASA Astrophysics Data System (ADS)

    Khaneft, A. V.; Ivanov, G. A.; Duginov, E. V.

    2015-04-01

    The criterion of the condensed explosive ignition by the electron beam, which takes into account Gaussian distribution of electron density along the beam radius, has been obtained. It has been shown that radial heat removal of the absorbed energy leads to the increase in critical ignition energy if the effective track length of electrons in a solid is commensurate with the beam radius. The critical energy of PETN initiation by the electron beam has been calculated.

  18. Experimental determination of the radius of curvature of an isotropic Gaussian Schell-model beam.

    PubMed

    Zhu, Shijun; Chen, Yahong; Cai, Yangjian

    2013-02-01

    We propose a method to determine the radius of curvature of an isotropic Gaussian Schell-model (GSM) beam by measuring the transverse beam widths and the transverse coherence widths at two different planes. Furthermore, we carry out experimental determination of the radius of curvature of a GSM beam. Using the measured beam parameters, we carry out a comparative study of the propagation properties of a GSM beam both theoretically and experimentally. Our experimental results agree well with theoretical predictions.

  19. "Osteoporosis and orthopods" incidences of osteoporosis in distal radius fracture from low energy trauma.

    PubMed

    Bahari, Syah; Morris, Seamus; Lenehan, Brian; McElwain, John P

    2007-07-01

    Fracture of the distal radius from low energy trauma is a common presentation to orthopaedic trauma services. This fragility type fracture is associated with underlying osteoporosis. Osteoporosis is a 'silent disease' where fragility fracture is a common presentation. Orthopaedic surgeons may be the only physician that these patients encounter. We found a high percentage of female patients who sustained a fragility fracture of the distal radius have an underlying osteoporosis. Further management of osteoporosis is important to prevent future fragility fractures.

  20. Carpal tunnel syndrome: A rare manifestation of distal radius osteoid osteoma.

    PubMed

    Basran, Sukhvinder Singh; Kumar, Sandeep; Jameel, Javed; Sajid, Imran

    2015-09-01

    Osteoid Osteoma is a benign bone tumor that normally affects long bones and rarely affects distal radius. Because of its nonspecific presentation in the wrist, it remains a diagnostic challenge. We report an unusual case of Osteoid Osteoma at distal radius having symptoms resembling that of carpal tunnel syndrome. The diagnosis was confirmed preoperatively with X-rays; bone scintigraphy, CT, and MRI, later histological examination confirmed the diagnoses. Surgical excision lead to a dramatic improvement in the condition of the patient.