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Sample records for le calorimetre electromagnetique

  1. Quantification du champ electromagnetique et description quantique de la generation du second harmonique a l'interieur d'une microcavite

    NASA Astrophysics Data System (ADS)

    Collette, Marc

    L'existence de particules virtuelles qui surgissent spontanement du vide pour disparaitre tres peu de temps apres leur apparition (les fluctuations du vide) trouve son origine dans le principe d'incertitude de Heisenberg. Par ailleurs, on sait que le phenomene de resonance par confinement explique l'amplification de l'intensite lumineuse a l'interieur d'une cavite ouverte aux frequences de resonances de celle-ci. C'est pourquoi le taux d'apparition des photons virtuels au sein des modes propres d'une cavite est lui aussi amplifie par le resonateur. Mathematiquement, cet effet quantique est decrit par l'existence d'un commutateur " anomal " entre les operateurs d'annihilation et de creation des photons. Nous decrivons les consequences de ce commutateur sur la generation du second harmonique optique (GSH), un processus photonique ou, dans un materiau optiquement non lineaire, deux photons de meme energie fusionnent pour n'en former qu'un seul. On commence ce travail avec un traitement complet et original sur la quantification du champ electromagnetique. On montre ensuite que les fluctuations du vide stimulent le signal de la GSH a l'interieur du milieu confine. Cependant, on constate aussi que les fluctuations du vide jouent le role d'un inhibiteur au declenchement du processus, c'est-a-dire que le seuil de la GSH augmente (il est superieur au seuil minimal de deux photons seulement). En conclusion, les mecanismes intimes de certains processus optiques non lineaires doivent etre reconsideres lorsqu'ils surviennent en presence d'un confinement electromagnetique.

  2. Device for calorimetric measurement

    DOEpatents

    King, William P; Lee, Jungchul

    2015-01-13

    In one aspect, provided herein is a single crystal silicon microcalorimeter, for example useful for high temperature operation and long-term stability of calorimetric measurements. Microcalorimeters described herein include microcalorimeter embodiments having a suspended structure and comprising single crystal silicon. Also provided herein are methods for making calorimetric measurements, for example, on small quantities of materials or for determining the energy content of combustible material having an unknown composition.

  3. Electronic calorimetric computer

    NASA Technical Reports Server (NTRS)

    Heckelman, J. D.

    1968-01-01

    Electronic calorimetric computer calculates nuclear reactor thermal power output to a nominal accuracy of 1 percent. Heat balance is determined by an electronic approach. The thermal power is calculated using the inlet and outlet temperatures and the volume of cooling water and is displayed by a digital readout system.

  4. Calorimetric gas sensor

    DOEpatents

    Ricco, A.J.; Hughes, R.C.; Smith, J.H.; Moreno, D.J.; Manginell, R.P.; Senturia, S.D.; Huber, R.J.

    1998-11-10

    A combustible gas sensor is described that uses a resistively heated, noble metal-coated, micromachined polycrystalline Si filament to calorimetrically detect the presence and concentration of combustible gases. The filaments tested to date are 2 {micro}m thick {times} 10{micro}m wide {times} 100, 250, 500, or 1000 {micro}m-long polycrystalline Si; some are overcoated with a 0.25 {micro}m-thick protective CVD Si{sub 3}N{sub 4} layer. A thin catalytic Pt film was deposited by CVD from the precursor Pt(acac){sub 2} onto microfilaments resistively heated to approximately 500 C; Pt deposits only on the hot filament. Using a constant-resistance-mode feedback circuit, Pt-coated filaments operating at ca. 300 C (35 mW input power) respond linearly, in terms of the change in supply current required to maintain constant resistance (temperature), to H{sub 2} concentrations between 100 ppm and 1% in an 80/20 N{sub 2}/O{sub 2} mixture. Other catalytic materials can also be used. 11 figs.

  5. Calorimetric gas sensor

    DOEpatents

    Ricco, Antonio J.; Hughes, Robert C.; Smith, James H.; Moreno, Daniel J.; Manginell, Ronald P.; Senturia, Stephen D.; Huber, Robert J.

    1998-01-01

    A combustible gas sensor that uses a resistively heated, noble metal-coated, micromachined polycrystalline Si filament to calorimetrically detect the presence and concentration of combustible gases. The filaments tested to date are 2 .mu.m thick.times.10 .mu.m wide.times.100, 250, 500, or 1000 .mu.m-long polycrystalline Si; some are overcoated with a 0.25 .mu.m-thick protective CVD Si.sub.3 N.sub.4 layer. A thin catalytic Pt film was deposited by CVD from the precursor Pt(acac).sub.2 onto microfilaments resistively heated to approximately 500.degree. C.; Pt deposits only on the hot filament. Using a constant-resistance-mode feedback circuit, Pt-coated filaments operating at ca. 300.degree. C. (35 mW input power) respond linearly, in terms of the change in supply current required to maintain constant resistance (temperature), to H.sub.2 concentrations between 100 ppm and 1% in an 80/20 N.sub.2 /O.sub.2 mixture. Other catalytic materials can also be used.

  6. Thermal Analysis of Calorimetric Systems

    NASA Astrophysics Data System (ADS)

    D'Aulerio, L.; Violante, V.; Castagna, E.; Fiore, R.; Capobianco, L.; Del Prete, Pr.; Tanzella, F.; McKubre, M.

    Calorimetric analysis has been carried out for both electrochemical and gas loading experiment. A finite element modeling for steady state and transient gave a satisfactory agreement with the experimental results. For electrochemical cells modeling was applied for isoperibolic and flow calorimeters with the main goal to optimize the system. For high-temperature gas loading experiments the modeling was applied to translate the temperature field (steady state and transient three-dimensional analysis), then, in such a case calculations allowed to perform the calorimetry. This experiment was a replication of the MATRIX experiment performed at SRI by some of the authors.1,2 A correlation between 4He production and excess of power during gas loading of deuterium in palladium was observed. Excess of power was estimated by means of the temperature measurements and by comparing experimental data with both the calibration data and the modeling results. Also the effect of the room temperature evolution was considered in the mathematical model of the experiment. 4He tights stainless steel cell have been filled first with a Pd-based catalyst then loaded with deuterium or hydrogen (blank). After filling cells with gas we observed a different thermal behavior of the cells C1 and C2 containing deuterium, compared to the cell C4 containing hydrogen. The temperature increasing in cells C1 and C2 was estimated to be produced by an additional power source of 0.1 W. The measured excess of helium was consistent with expected value obtained by assuming that the excess of energy was produced by a D+D reaction giving 4He+heat (24 MeV). The slope of the temperature increasing was larger in cells C1 and C2, and after achieving a stationary condition for the system the temperature of cells C1 and C2 increased again. During the thermal effect an analysis of the gas was done for the cells C1 and C2. An increasing of the helium content was revealed for both the cells. The He concentration

  7. Calorimetric thermobarometry of experimentally shocked quartz

    NASA Technical Reports Server (NTRS)

    Ocker, Katherine D.; Gooding, James L.; Hoerz, Friedrich

    1994-01-01

    Structural damage in experimentally shock-metamorphosed, granular quartz is quantitatively measurable by differential scanning calorimetry (DSC). Shock-induced loss of crystallinity is witnessed by disappearance of the alpha/beta phase transformation and evolution of a broad endoenthalpic strain peak at 650-900 K. The strain-energy peak grows rapidly at less than 10 GPa but declines with increasing shock pressure; it approaches zero at 32 GPa where vitrification is extensive. Effects of grain size and post-shock thermal history must be better understood before calorimetric thermobarometry of naturally shocked samples becomes possible.

  8. Comparison and qualification of FFTF calorimetric methods

    SciTech Connect

    McCall, T.B.; Nutt, W.T.; Zimmerman, B.D.

    1981-01-01

    The Fast Flux Test Facility achieved full power operation on December 21, 1981. During the power ascent, the reactor thermal power (calorimetric) was computed by three methods as follows: the plant main data handling computer, Plant Data System (PDS); a second computer, the Experimenter's Data System (EDS); and a manual method requiring human operator activities and a programmable calculator. It is the purpose of this paper to explain the rationale for employing the three methods, describe how each works in a schematic fashion, compare the results, and demonstrate that all methods have met stringent goals based on a statistical analysis of the results.

  9. Radiation beam calorimetric power measurement system

    DOEpatents

    Baker, John; Collins, Leland F.; Kuklo, Thomas C.; Micali, James V.

    1992-01-01

    A radiation beam calorimetric power measurement system for measuring the average power of a beam such as a laser beam, including a calorimeter configured to operate over a wide range of coolant flow rates and being cooled by continuously flowing coolant for absorbing light from a laser beam to convert the laser beam energy into heat. The system further includes a flow meter for measuring the coolant flow in the calorimeter and a pair of thermistors for measuring the temperature difference between the coolant inputs and outputs to the calorimeter. The system also includes a microprocessor for processing the measured coolant flow rate and the measured temperature difference to determine the average power of the laser beam.

  10. Calorimetric sensors for energy deposition measurements

    SciTech Connect

    Langenbrunner, J.; Cooper, R.; Morgan, G.

    1998-12-31

    A calorimetric sensor with several novel design features has been developed. These sensors will provide an accurate sampling of thermal power density and energy deposition from proton beams incident on target components of accelerator-based systems, such as the Accelerator Production of Tritium Project (APT) and the Spallation Neutron Source (SNS). A small, solid slug (volume = 0.347 cc) of target material is suspended by kevlar fibers and surrounded by an adiabatic enclosure in an insulating vacuum canister of stainless steel construction. The slug is in thermal contact with a low-mass, calibrated, 100-k{Omega} thermistor. Power deposition caused by the passage of radiation through the slug is calculated from the rate of temperature rise of the slug. The authors have chosen slugs composed of Pb, Al, and LiAl.

  11. Adaptive measurement control for calorimetric assay

    SciTech Connect

    Glosup, J.G.; Axelrod, M.C.

    1994-10-01

    The performance of a calorimeter is usually evaluated by constructing a Shewhart control chart of its measurement errors for a collection of reference standards. However, Shewhart control charts were developed in a manufacturing setting where observations occur in batches. Additionally, the Shewhart control chart expects the variance of the charted variable to be known or at least well estimated from previous experimentation. For calorimetric assay, observations are collected singly in a time sequence with a (possibly) changing mean, and extensive experimentation to calculate the variance of the measurement errors is seldom feasible. These facts pose problems in constructing a control chart. In this paper, the authors propose using the mean squared successive difference to estimate the variance of measurement errors based solely on prior observations. This procedure reduces or eliminates estimation bias due to a changing mean. However, the use of this estimator requires an adjustment to the definition of the alarm and warning limits for the Shewhart control chart. The authors propose adjusted limits based on an approximate Student`s t-distribution for the measurement errors and discuss the limitations of this approximation. Suggestions for the practical implementation of this method are provided also.

  12. A calorimetric method to determine water activity

    NASA Astrophysics Data System (ADS)

    Björklund, Sebastian; Wadsö, Lars

    2011-11-01

    A calorimetric method to determine water activity covering the full range of the water activity scale is presented. A dry stream of nitrogen gas is passed either over the solution whose activity should be determined or left dry before it is saturated by bubbling through water in an isothermal calorimeter. The unknown activity is in principle determined by comparing the thermal power of vaporization related to the gas stream with unknown activity to that with zero activity. Except for three minor corrections (for pressure drop, non-perfect humidification, and evaporative cooling) the unknown water activity is calculated solely based on the water activity end-points zero and unity. Thus, there is no need for calibration with references with known water activities. The method has been evaluated at 30 °C by measuring the water activity of seven aqueous sodium chloride solutions ranging from 0.1 mol kg-1 to 3 mol kg-1 and seven saturated aqueous salt solutions (LiCl, MgCl2, NaBr, NaCl, KCl, KNO3, and K2SO4) with known water activities. The performance of the method was adequate over the complete water activity scale. At high water activities the performance was excellent, which is encouraging as many other methods used for water activity determination have limited performance at high water activities.

  13. Calorimetric study of peroxycarboxylic ester synthesis.

    PubMed

    Fritzsche, L; Knorr, A

    2009-04-30

    Exothermic reactions involving organic peroxides carry a high potential hazard and must be considered with care. A safe handling requires, among others, the assessment of thermal process safety, for which safety characteristics like overall heat production and the resulting adiabatic temperature rise are essential. The article presents the results of the calorimetric investigation of the synthesis of four peroxycarboxylic esters, three tert-Butyl and one tert-Amyl peroxycarboxylic ester. In the two-step synthesis the second one clearly shows the higher exothermic potential. The overall heat production lies in the range of 126-135 kJ/mol and is nearly independent of the carboxylic acid residual in the tert-Butyl peroxycarboxylic ester. The calculated adiabatic temperature rise is 70-80K. Influence of temperature and feed rate on the heat generation is discussed for one species. A grading of the synthesis with respect to temperature levels according to the criticality classes by Stoessel leads to the most critical for an exothermic reaction.

  14. Polymer principles of protein calorimetric two-state cooperativity.

    PubMed

    Kaya, H; Chan, H S

    2000-09-01

    The experimental calorimetric two-state criterion requires the van't Hoff enthalpy DeltaH(vH) around the folding/unfolding transition midpoint to be equal or very close to the calorimetric enthalpy DeltaH(cal) of the entire transition. We use an analytical model with experimental parameters from chymotrypsin inhibitor 2 to elucidate the relationship among several different van't Hoff enthalpies used in calorimetric analyses. Under reasonable assumptions, the implications of these DeltaH(vH)'s being approximately equal to DeltaH(cal) are equivalent: Enthalpic variations among denatured conformations in real proteins are much narrower than some previous lattice-model estimates, suggesting that the energy landscape theory "folding to glass transition temperature ratio" T(f) /T(g) may exceed 6.0 for real calorimetrically two-state proteins. Several popular three-dimensional lattice protein models, with different numbers of residue types in their alphabets, are found to fall short of the high experimental standard for being calorimetrically two-state. Some models postulate a multiple-conformation native state with substantial pre-denaturational energetic fluctuations well below the unfolding transition temperature, or predict a significant post-denaturational continuous conformational expansion of the denatured ensemble at temperatures well above the transition point, or both. These scenarios either disagree with experiments on protein size and dynamics, or are inconsistent with conventional interpretation of calorimetric data. However, when empirical linear baseline subtractions are employed, the resulting DeltaH(vH)/DeltaH(cal)'s for some models can be increased to values closer to unity, and baseline subtractions are found to correspond roughly to an operational definition of native-state conformational diversity. These results necessitate a re-assessment of theoretical models and experimental interpretations.

  15. Calorimetric method for determination of 51Cr neutrino source activity

    NASA Astrophysics Data System (ADS)

    Veretenkin, E. P.; Gavrin, V. N.; Danshin, S. N.; Ibragimova, T. V.; Kozlova, Yu. P.; Mirmov, I. N.

    2015-12-01

    Experimental study of nonstandard neutrino properties using high-intensity artificial neutrino sources requires the activity of the sources to be determined with high accuracy. In the BEST project, a calorimetric system for measurement of the activity of high-intensity (a few MCi) neutrino sources based on 51Cr with an accuracy of 0.5-1% is created. In the paper, the main factors affecting the accuracy of determining the neutrino source activity are discussed. The calorimetric system design and the calibration results using a thermal simulator of the source are presented.

  16. Calorimetric Studies at the New Hydrogen Energy Laboratory in Japan

    NASA Astrophysics Data System (ADS)

    Miles, Melvin H.

    2000-03-01

    Experiments using China Lake type calorimetric cells produced excess power in three out of three experiments and no excess power in three control studies. A detailed analysis is presented for two experiments using the China Lake cells. Anomalous thermistor signals in Cell A suggest the emission of electromagnetic radiation from the active palladium cathode. Experiments in Fleischmann-Pons type calorimetric cells produced excess power in six out of eight experiments. These studies involved palladium alloy cathodes, co-deposition of palladium and deuterium from the solution, and electromigration using thin palladium wires.

  17. Calorimetric Thermometry of Meteoritic Troilite: Early Reconnaissance

    NASA Astrophysics Data System (ADS)

    Allton, J. H.; Wentworth, S. J.; Gooding, J. L.

    1993-07-01

    are the consequence of different thermal histories. Multiple samples of Del Norte troilite were used to determine the influence of laboratory-scale thermal histories on DSC signatures by heating and cooling each sample under different programmed conditions. In reconnaissance experiments, maximum temperature achieved during heat treatment appears to be more influential than does either the time maintained at temperature or the heating/cooling rate. The experimentally measured alpha/beta onset temperature shows a systematic decline with maximum temperature achieved during prior heating, suggesting that high onset temperatures are indicative of low maximum temperatures in the natural histories of the troilite samples. That trend is at least qualitatively consistent with the petrologic rankings of the meteorites in which troilite from the relatively unmetamorphosed L3 chondrite shows a higher onset temperature than does troilite from either the highly metamorphosed L7 chondrite or the octahedrite. Additional work should define the limits of a quantitative calibration that might ultimately permit derivation of meteorite thermal histories by calorimetric thermometry of troilite. Samples were kindly provided by E. R. D. Scott (Mundrabilla), C. B. Moore (Del Norte), and the Meteorite Working Group (PAT91501; EET83213 powder from E. Jarosewich). References: [1] Chase M. W. Jr. et al. (1985) JANAF Thermochemical Tables, 3rd ed., 1194. [2] Robie R. A. et al. (1979) Geol. Surv. Bull. 1452, 125. [3] Allton J. H. and Gooding J. L. (1993) LPS XXIV, 21-22. Fig. 1, which appears here in the hard copy, shows the thermodynamics of troilite alpha/beta phase transformations measured by DSC during first-heat cycles.

  18. Calorimetric Measurements of Laser Energy and Power- 1975 Supplement

    DTIC Science & Technology

    1975-07-30

    Bolometer Volume Absorption Partial Reflectance Absorptance Measurement Test Comparison Pages: 00021 Cataloged Date: Dec 07,1992 Document Type: HC...Hollow-Sphere Calorimeters 4 Bolometer Calorimeters 5 Volume- Absorption Calorimeters 5 Partial- Absorption Calorimeters 7 Reflectance and... Absorptance Measurements 7 Test and Comparison Procedures 7 Miscellany 7 References 14 -in- CALORIMETRIC MEASUREMENTS OF LASER ENERGY AND

  19. New calorimetric AC loss measurement technique involving superfluid helium

    SciTech Connect

    Baudouy, B.J.P.; Bartholomew, K.; Van Sciver, S.W.

    1996-12-31

    The authors have developed a new calorimetric AC loss measurement facility involving superfluid helium (He II). At present, the Test of AC Loss (TACL) facility performs AC loss measurements on Cable-in-Conduit Conductors (CICC) under development for the NHMFL 45 Tesla hybrid superconducting outsert magnet. TACL can handle large scale conductors up to one meter in length. Measurements utilize the exceptional high heat conductivity of He II, which provides an isothermal environment and is the dominant enthalpy in the system. The test conductors are placed in an independent cryostat containing He II which is inserted in a superconducting dipole magnet producing a transverse magnetic field up to 7 T. For a change of the magnetic field and associated AC loss, the temperature variation of the He II surrounding the conductor is measured and directly converted to enthalpy variation of the He II. This paper describes the measurement technique and compares its resolution to that of more conventional calorimetric AC loss measurements.

  20. Calorimetric Measurements of Liquid Al-Zn Alloys

    NASA Astrophysics Data System (ADS)

    Dębski, Adam; Gąsior, Władysław; Szmit, Katarzyna

    2016-10-01

    The integral molar enthalpies of mixing were determined by the drop calorimetric method for binary AL-Zn liquid solutions and compared with the Miedema model as well as the earlier experimental data. The measurements were conducted at two temperatures: 957 K and 1001 K (684 °C and 728 °C), in the entire concentration range. Based on the experimental calorimetric data of this study as well as those available in the literature and the results of the activity studies, the interaction parameters of the Redlich-Kister equation for the liquid Al-Zn phase were worked out with the use of the least square method. The partial and integral Gibbs energies, entropies and enthalpies were calculated and presented in tables and figures. Additionally, the concentration-concentration partial structure factors for the ideal and real Al-Zn solutions were calculated and graphically presented.

  1. A Possible Calorimetric Error in Heavy Water Electrolysis on Platinum

    SciTech Connect

    Shanahan, K.L.

    2001-03-16

    A systematic error in mass flow calorimetry calibration procedures potentially capable of explaining most positive excess power measurements is described. Data recently interpreted as providing evidence of the Pons-Fleischmann effect with a platinum cathode are reinterpreted with the opposite conclusion. This indicates it is premature to conclude platinum displays a Pons and Fleischmann effect, and places the requirement to evaluate the error's magnitude on all mass flow calorimetric experiments.

  2. Measurement of the calorimetric energy scale in MINOS

    SciTech Connect

    Hartnell, Jeffrey J.

    2005-01-01

    MINOS is a long-baseline neutrino oscillation experiment. A neutrino beam is created at the Fermi National Accelerator Laboratory in Illinois and fired down through the Earth. Measurements of the energy spectra and composition of the neutrino beam are made both at the source using the Near detector and 735 km away at the Soudan Underground Laboratory in Minnesota using the Far detector. By comparing the spectrum and flavour composition of the neutrino beam between the two detectors neutrino oscillations can be observed. Such a comparison depends on the accuracy of the relative calorimetric energy scale. This thesis details a precise measurement of the calorimetric energy scale of the MINOS Far detector and Calibration detector using stopping muons with a new ''track window'' technique. These measurements are used to perform the relative calibration between the two detectors. This calibration has been accomplished to 1.7% in data and to significantly better than 2% in the Monte Carlo simulation, thus achieving the MINOS relative calibration target of 2%. A number of cross-checks have been performed to ensure the robustness of the calorimetric energy scale measurements. At the Calibration detector the test-beam energy between run periods is found to be consistent with the detector response to better than 2% after the relative calibration is applied. The muon energy loss in the MINOS detectors determined from Bethe-Bloch predictions, data and Monte Carlo are compared and understood. To estimate the systematic error on the measurement of the neutrino oscillation parameters caused by a relative miscalibration a study is performed. A 2% relative miscalibration is shown to cause a 0.6% bias in the values of Δm2 and sin2(2θ).

  3. Calorimetric power measurements in the EAST ECRH system

    NASA Astrophysics Data System (ADS)

    Xu, Weiye; Xu, Handong; Liu, Fukun; Wang, Jian; Wang, Xiaojie; Hou, Yongzhong

    2017-10-01

    In this paper, the measurement method of calorimetric power for an electron cyclotron resonance heating (ECRH) system for EAST is presented. This method requires measurements of the water flow through the cooling circuits and the input and output water temperatures in each cooling circuit. Usually, the inlet water temperature stability is controlled to obtain more accurate results. The influence of the inlet water temperature change on the measurement results is analyzed for the first time in this paper. Also, a novel temperature calibration method is proposed. This kind of calibration method is accurate and effective, and can be easily implemented.

  4. ASIC for calorimetric measurements in the astrophysical experiment NUCLEON

    NASA Astrophysics Data System (ADS)

    Atkin, E.; Voronin, A.; Karmanov, D.; Kudryashov, I.; Kovalev, I.; Shumikhin, V.

    2016-02-01

    A satellite with the NUCLEON apparatus was launched in Dec. 2014. The space NUCLEON project of ROSCOSMOS is designed to investigate cosmic ray nuclei energy spectra from 100 GeV to 1000 TeV as well as cosmic ray electron spectra from 20 GeV to 3 TeV. The method of energy determination by means of a silicon instrument for measuring the particle charge of cosmic rays and the calorimetric system were developed. The main parameters, that determine the quality of calorimetric systems are linearity of transfer characteristic and the dynamic range of input signals, which should reach 30 000 MIPs (minimum ionizing particles). The ASIC, satisfying these requirements, consisting of 32 channels with a unique dynamic range from 1 to 40000 MIPs, signal to noise ratio not less than 2.5 at a shaper peaking time of 2 μs and a low power consumption of 1.5 mW/channel has been designed. The first results of the ASIC functionality in space are presented.

  5. Calorimetric measurement of work for a driven harmonic oscillator.

    PubMed

    Sampaio, Rui; Suomela, Samu; Ala-Nissila, Tapio

    2016-12-01

    A calorimetric measurement has recently been proposed as a promising technique to measure thermodynamic quantities in a dissipative superconducting qubit. These measurements rely on the fact that the system is projected into energy eigenstates whenever energy is exchanged with the environment. This requirement imposes a restriction on the class of systems that can be measured in this way. Here we extend the calorimetric protocol to the measurement of work in a driven quantum harmonic oscillator. We employ a scheme based on a two-level approximation that makes use of an experimentally accessible quantity and show how it relates to the work obtained through the standard two-measurement protocol. We find that the average work is well approximated in the underdamped regime for short driving times and, in the overdamped regime, for any driving time. However, this approximation fails for the variance and higher moments of work at finite temperatures. Furthermore, we show how to relate the work statistics obtained through this scheme to the work statistics given by the two-measurement protocol.

  6. Novel micro-calorimetric spectroscopy for mine detection

    SciTech Connect

    Datskos, P.G. |; Rajic, S.; Egert, C.M.; Datskou, I.

    1998-03-01

    The authors have developed a novel micro-calorimetric spectroscopy technique that can be used in mine detection applications. In this technique target molecules are allowed to adsorb on the surface of sub-femtojoule sensitive micromechanical thermal detectors. The adsorption of molecules on the thermal detector surface causes a differential surface stress resulting in an initial trigger. By exposing each element in an array of thermal detectors to different photon wavelengths, an extremely sensitive and unique photothermal signature response can be obtained. The authors present their results on target chemicals adsorbed on the detector surface at sub-monolayer coverage levels. They will present infrared photothermal spectra for trace concentrations of diisopropyl methylphosphonate (DIMP), and trinitrotoluene (TNT) over the wavelength region 2.5 to 14.5 microns. They found that in the wavelength region 2.5 to 14.5 microns the photothermal spectra of DIMP and TNT exhibit a number of peaks and are in excellent agreement with infrared absorption spectra found in the literature. Chemical detectors based on micro-calorimetric spectroscopy can be used to sensitively sense small number of molecules adsorbed on a thermal detector surface. The photothermal signature resulting from photon irradiation can be used for improved chemical characterization.

  7. Adiabatic calorimetric decomposition studies of 50 wt.% hydroxylamine/water.

    PubMed

    Cisneros, L O; Rogers, W J; Mannan, M S

    2001-03-19

    Calorimetric data can provide a basis for determining potential hazards in reactions, storage, and transportation of process chemicals. This work provides calorimetric data for the thermal decomposition behavior in air of 50wt.% hydroxylamine/water (HA), both with and without added stabilizers, which was measured in closed cells with an automatic pressure tracking adiabatic calorimeter (APTAC). Among the data provided are onset temperatures, reaction order, activation energies, pressures of noncondensable products, thermal stability at 100 degrees C, and the effect of HA storage time. Discussed also are the catalytic effects of carbon steel, stainless steel, stainless steel with silica coating, inconel, titanium, and titanium with silica coating on the reaction self-heat rates and onset temperatures. In borosilicate glass cells, HA was relatively stable at temperatures up to 133 degrees C, where the HA decomposition self-heat rate reached 0.05 degrees C/min. The added stabilizers appeared to reduce HA decomposition rates in glass cells and at ambient temperatures. The tested metals and metal surfaces coated with silica acted as catalysts to lower the onset temperatures and increase the self-heat rates.

  8. Metal carbon bond energies for adsorbed hydrocarbons from calorimetric data

    NASA Astrophysics Data System (ADS)

    Gross, Heike; Campbell, Charles T.; King, David A.

    2004-11-01

    Single crystal adsorption calorimetry (SCAC) is a powerful new method for measuring adsorption and reaction energies. Particularly for hydrocarbons, where little or no information is available from either experiment or theory on well-defined surfaces, this method can provide crucially needed information. Assignment of the measured calorimetric heats to the appropriate surface reaction yields directly reaction heats and heats of formation of surface species. An important extension using these results is to derive values for metal-carbon bond energies in adsorbed hydrocarbon species. In this paper we review the definition of the bond dissociation energy for a surface species and discuss methodologies and limitations for calculating accurate values of this quantity from measured calorimetric data. As a step in establishing benchmark data for adsorbed hydrocarbons, we calculate a Pt-C σ bond strength, < D(Pt-C)>, of about 245 kJ/mol from data for ethylidyne on Pt{1 1 1}. Two independent methods, the quasiempirical valence bond (QVB) method and an average bond energy (ABE) method, were used to obtain this value, and the two values derived from these two approaches agree quite well. We also discuss the implications and applicability of this value of D(Pt-C) for other adsorbed hydrocarbons and on other Pt surfaces, and estimates of how this bond energy should differ when the C atom's ligands are different.

  9. Calorimetric measurement of work for a driven harmonic oscillator

    NASA Astrophysics Data System (ADS)

    Sampaio, Rui; Suomela, Samu; Ala-Nissila, Tapio

    2016-12-01

    A calorimetric measurement has recently been proposed as a promising technique to measure thermodynamic quantities in a dissipative superconducting qubit. These measurements rely on the fact that the system is projected into energy eigenstates whenever energy is exchanged with the environment. This requirement imposes a restriction on the class of systems that can be measured in this way. Here we extend the calorimetric protocol to the measurement of work in a driven quantum harmonic oscillator. We employ a scheme based on a two-level approximation that makes use of an experimentally accessible quantity and show how it relates to the work obtained through the standard two-measurement protocol. We find that the average work is well approximated in the underdamped regime for short driving times and, in the overdamped regime, for any driving time. However, this approximation fails for the variance and higher moments of work at finite temperatures. Furthermore, we show how to relate the work statistics obtained through this scheme to the work statistics given by the two-measurement protocol.

  10. Calorimetric Aerogel Collectors/Detectors of Hypervelocity Dust Grains

    NASA Astrophysics Data System (ADS)

    Dominguez, G.; Westphal, A. J.; Phillips, M. L. F.; Jones, S. M.

    Distinguishing between lower velocity (<8 km/s) orbital debris impacts and higher velocity extraterrestrial particles collected in aerogels was the primary driver behind our development of calorimetric aerogels. While low-density aerogels have been shown to be superior at maximizing the survival of captured hypervelocity projectiles, reconstructing the impact velocity has not been possible. We have previously demonstrated that the shock heating experienced by Gd:Tb doped alumina aerogels results in the production of permanently fluorescent impact cavities. In addition, we have shown that the amount of induced (with UV illumination) fluorescence correlates with the kinetic energy of the captured projectile. Improvements in our production capabilities have recently allowed us to measure, using a Ti-doped Si/Al aerogel, the intrinsic resolution of using this technique to reconstruct the velocity of captured hypervelocity projectiles. We are currently exploring composition space in order to optimize the sensitivity and mechanical properties of these collector/detectors. We report on the results from our latest round of hypervelocity tests as well as the expected collection statistics of deploying a 3 square meter array of calorimetric aerogels in low-Earth-orbit (LEO).

  11. Determination of Nuclear Charge Distributions of Fission Fragments from ^{235}U (n_th, f) with Calorimetric Low Temperature Detectors

    NASA Astrophysics Data System (ADS)

    Grabitz, P.; Andrianov, V.; Bishop, S.; Blanc, A.; Dubey, S.; Echler, A.; Egelhof, P.; Faust, H.; Gönnenwein, F.; Gomez-Guzman, J. M.; Köster, U.; Kraft-Bermuth, S.; Mutterer, M.; Scholz, P.; Stolte, S.

    2016-08-01

    Calorimetric low temperature detectors (CLTD's) for heavy-ion detection have been combined with the LOHENGRIN recoil separator at the ILL Grenoble for the determination of nuclear charge distributions of fission fragments produced by thermal neutron-induced fission of ^{235}U. The LOHENGRIN spectrometer separates fission fragments according to their mass-to-ionic-charge ratio and their kinetic energy, but has no selectivity with respect to nuclear charges Z. For the separation of the nuclear charges, one can exploit the nuclear charge-dependent energy loss of the fragments passing through an energy degrader foil (absorber method). This separation requires detector systems with high energy resolution and negligible pulse height defect, as well as degrader foils which are optimized with respect to thickness, homogeneity, and energy loss straggling. In the present, contribution results of test measurements at the Maier Leibnitz tandem accelerator facility in Munich with ^{109}Ag and ^{127}I beams with the aim to determine the most suitable degrader material, as well as measurements at the Institut Laue-Langevin will be presented. These include a systematic study of the quality of Z-separation of fission fragments in the mass range 82le A le 132 and a systematic measurement of ^{92}Rb fission yields, as well as investigations of fission yields toward the symmetry region.

  12. Preparation, structural, and calorimetric characterization of bicomponent metallic photonic crystals

    NASA Astrophysics Data System (ADS)

    Kozlov, M. E.; Murthy, N. S.; Udod, I.; Khayrullin, I. I.; Baughman, R. H.; Zakhidov, A. A.

    2007-03-01

    We report preparation and characterization of novel bicomponent metal-based photonic crystals having submicron three-dimensional (3D) periodicity. Fabricated photonic crystals include SiO2 sphere lattices infiltrated interstitially with metals, carbon inverse lattices filled with metal or metal alloy spheres, Sb inverse lattices, and Sb inverse lattices filled with Bi spheres. Starting from a face centered SiO2 lattice template, these materials were obtained by sequences of either templating and template extraction or templating, template extraction, and retemplating. Surprising high fidelity was obtained for all templating and template extraction steps. Scanning electron microscopy (SEM), small angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC) were used to characterize the structure and the effects of the structure on calorimetric properties. To the best of our knowledge, SAXS data on metallic photonic crystals were collected for first time.

  13. Synthesis of nitrate sodalite: An in situ scanning calorimetric study

    NASA Astrophysics Data System (ADS)

    Liu, Qingyuan; Navrotsky, Alexandra

    2007-04-01

    The formation of nitrate sodalite, an important constituent of the resilient heels at DOE nuclear waste storage sites, was closely followed by oven synthesis, in situ calorimetry as a function of heating rate from 0.01 to 0.1 °C/min and X-ray diffraction. A transition sequence of amorphous-zeolite A-sodalite-cancrinite was confirmed. For in situ synthesis calorimetry, the heat flow peaks related to zeolite A formation are shifted to higher temperatures as heating rate increases. Although the end products are mostly nitrate sodalite, no calorimetric signals associated with zeolite A to sodalite conversion are detected. This suggests that the enthalpy of formation of zeolite A and sodalite are very similar and the zeolite A to sodalite conversion enthalpy is small. This conclusion is in accord with previous measurements by oxide melt solution calorimetry.

  14. Calorimetric study of tellurium rich Se-Te-Sn glasses

    NASA Astrophysics Data System (ADS)

    Heera, Pawan; Kumar, Anup; Jharwal, Manish; Sharma, Raman

    2016-05-01

    We report the calorimetric study of amorphous Se30Te70-x Snx alloys for x= 0, 1.5, 2.5, 4.5 in terms of kinetic parameters. The DSC curves recorded at four different heating rates are analyzed to determine the transition temperatures, activation energy, thermal stability, glass forming ability. The crystallization process has been investigated using Kissinger, Matusita, Augis and Bennett, and Gao and Wang models. Various kinetic parameters have been calculated for a better understanding of the growth mechanism. The glass transition temperatures Tg, onset crystallization Tc, peak crystallization Tp, and melting temperature Tm are found to increase with the increase in Sn content. The system under investigation is found to be thermally stable for at lower at% of Sn. The values of parameters HR, Hw, and S indicate that Glass forming ability (GFA) decays with an increase in Sn content.

  15. Calorimetric measurement and modelling of the equivalent series of capacitors

    NASA Astrophysics Data System (ADS)

    Seguin, B.; Gosse, J. P.; Ferrieux, J. P.

    1999-12-01

    The equivalent series resistance of polypropylene capacitors has been determined under rated voltage, in the range 1 kHz 1 MHz, between 220 K and 370 K by a calorimetric technique. The original feature of this determination of capacitor losses lies in the use of the isothermal calorimetry and in the measurement of an electrical power and not of a temperature increase. The frequency dependence of the equivalent series resistance, at various temperatures, enables to separate the losses in the conducting material from those in the dielectric and to get their respective variations as a function of frequency and temperature. These variations of the equivalent series resistance with frequency at a given temperature have been reproduced by using an equivalent circuit composed of resistors, inductors and capacitors. This model has been verified for non-sinusoidal waveforms such as those met with in a filtering circuit and is used to evaluate by simulation the losses of the capacitor.

  16. The calorimetric measurement of low energy brachytherapy sources

    NASA Astrophysics Data System (ADS)

    Aus, Robert John

    Historically, the dose rate to tissue from 125I and 103Pd sources was based on a source's apparent activity in free space. The American Association of Physicists in Medicine Task Group 43 (TG43) established a protocol that clarified this formalism for the dose rate determination that was universally accepted in the Medical Physics community. The TG43 protocol is based on air kerma strength and a different set of conversion factors for determining the dose rate. However, there are still many uncertainties associated with this methodology. These uncertainties are predominantly the result of the unknown effects of variations in the source encapsulation and internal source structure on the dose distribution surrounding a source. Currently, there is no method of nondestructively determining the contained radioactivity of brachytherapy sources. Without the knowledge of the contained activity, the effects of source construction variations cannot be evaluated accurately. The goal of this work was to develop a calorimeter that measures the total power generated by a source. This information could then be used to nondestructively determine the contained radioactivity activity of a source. The power generated by three different, well characterized source designs of 125I brachytherapy seeds was measured with the calorimeter. A theoretical model of the calorimeter was also developed to demonstrate that the calorimeter operated as expected. The measured and theoretical temperature results for the three different source models were consistent within the uncertainty of the measurements. The consistency between the calorimetric measurements and the theoretical expected results demonstrates proof of principle of the calorimeter. The information determined from the model can also be useful for future calorimetric research by identifying required calorimeter design features, potential design improvements and potential difficulties.

  17. Remote calorimetric detection of urea via flow injection analysis

    PubMed Central

    Gaddes, David E.; Demirel, Melik C.; Reeves, W. Brian; Tadigadapa, Srinivas

    2017-01-01

    The design and development of a calorimetric biosensing system enabling relatively high throughput sample analysis are reported. The calorimetric biosensor system consists of a thin (~20 μm) micromachined Y-cut quartz crystal resonator (QCR) as a temperature sensor placed in close proximity to a fluidic chamber packed with an immobilized enzyme. Layer by layer enzyme immobilization of urease is demonstrated and its activity as a function of the number of layers, pH, and time has been evaluated. This configuration enables a sensing system where a transducer element is physically separated from the analyte solution of interest and is thereby free from fouling effects typically associated with biochemical reactions occuring on the sensor surface. The performance of this biosensing system is demonstrated by detection of 1–200 mM urea in phosphate buffer via a flow injection analysis (FIA) technique. Miniaturized fluidic systems were used to provide continuous flow through a reaction column. Under this configuration the biosensor has an ultimate resolution of less than 1 mM urea and showed a linear response between 0–50 mM. This work demonstrates a sensing modality in which the sensor itself is not fouled or contaminated by the solution of interest and the enzyme immobilized Kapton® fluidic reaction column can be used as a disposable cartridge. Such a system enables reuse and reliability for long term sampling measurements. Based on this concept a biosensing system is envisioned which can perform rapid measurements to detect biomarkers such as glucose, creatinine, cholesterol, urea and lactate in urine and blood continuously over extended periods of time. PMID:26479269

  18. Remote calorimetric detection of urea via flow injection analysis.

    PubMed

    Gaddes, David E; Demirel, Melik C; Reeves, W Brian; Tadigadapa, Srinivas

    2015-12-07

    The design and development of a calorimetric biosensing system enabling relatively high throughput sample analysis are reported. The calorimetric biosensor system consists of a thin (∼20 μm) micromachined Y-cut quartz crystal resonator (QCR) as a temperature sensor placed in close proximity to a fluidic chamber packed with an immobilized enzyme. Layer by layer enzyme immobilization of urease is demonstrated and its activity as a function of the number of layers, pH, and time has been evaluated. This configuration enables a sensing system where a transducer element is physically separated from the analyte solution of interest and is thereby free from fouling effects typically associated with biochemical reactions occuring on the sensor surface. The performance of this biosensing system is demonstrated by detection of 1-200 mM urea in phosphate buffer via a flow injection analysis (FIA) technique. Miniaturized fluidic systems were used to provide continuous flow through a reaction column. Under this configuration the biosensor has an ultimate resolution of less than 1 mM urea and showed a linear response between 0-50 mM. This work demonstrates a sensing modality in which the sensor itself is not fouled or contaminated by the solution of interest and the enzyme immobilized Kapton® fluidic reaction column can be used as a disposable cartridge. Such a system enables reuse and reliability for long term sampling measurements. Based on this concept a biosensing system is envisioned which can perform rapid measurements to detect biomarkers such as glucose, creatinine, cholesterol, urea and lactate in urine and blood continuously over extended periods of time.

  19. High-resolution differential scanning calorimetric analysis of the subunits of Escherichia coli aspartate transcarbamoylase.

    PubMed

    Edge, V; Allewell, N M; Sturtevant, J M

    1985-10-08

    The thermal denaturation of the catalytic (c3) and regulatory (r2) subunits of Escherichia coli aspartate transcarbamoylase (c6r6) in the absence and presence of various ligands has been studied by means of highly sensitive differential scanning calorimetry. The denaturation of both types of subunit is irreversible as judged by the facts that the proteins coagulate when heated and that no endotherm is observed when previously scanned protein is rescanned. Despite this apparent irreversibility, there is empirical justification for analyzing the calorimetric data in terms of equilibrium thermodynamics as embodied in the van't Hoff equation. The observed curves of excess apparent specific heat vs. temperature are asymmetric and can be expressed within experimental uncertainty as the sums of sequential two-state steps, a minimum of two steps being required for r2 and three for c3. As previously reported [Vickers, K. P., Donovan, J. W., & Schachman, H. K. (1978) J. Biol. Chem. 253, 8493-8498], the addition of the effectors ATP and CTP raises the denaturation temperature of r2 and lowers that of c3 while the addition of the bisubstrate analogue N-(phosphonoacetyl)-L-aspartate raises the denaturation temperature of c3 and lowers that of r2. These effects vary with ligand concentration in the manner expected from the van't Hoff equation, indicating that they are simply manifestations of Le Chatelier's principle rather than being due to "stabilization" or "destabilization" of the proteins. The denaturational enthalpy is increased in those cases of ligand binding in which the denaturation temperature is increased, because of the contribution from the enthalpy of dissociation of the ligand.

  20. Calorimetric and relaxation properties of xylitol-water mixtures

    NASA Astrophysics Data System (ADS)

    Elamin, Khalid; Sjöström, Johan; Jansson, Helén; Swenson, Jan

    2012-03-01

    We present the first broadband dielectric spectroscopy (BDS) and differential scanning calorimetry study of supercooled xylitol-water mixtures in the whole concentration range and in wide frequency (10-2-106 Hz) and temperature (120-365 K) ranges. The calorimetric glass transition, Tg, decreases from 247 K for pure xylitol to about 181 K at a water concentration of approximately 37 wt. %. At water concentrations in the range 29-35 wt. % a plentiful calorimetric behaviour is observed. In addition to the glass transition, almost simultaneous crystallization and melting events occurring around 230-240 K. At higher water concentrations ice is formed during cooling and the glass transition temperature increases to a steady value of about 200 K for all higher water concentrations. This Tg corresponds to an unfrozen xylitol-water solution containing 20 wt. % water. In addition to the true glass transition we also observed a glass transition-like feature at 220 K for all the ice containing samples. However, this feature is more likely due to ice dissolution [A. Inaba and O. Andersson, Thermochim. Acta, 461, 44 (2007)]. In the case of the BDS measurements the presence of water clearly has an effect on both the cooperative α-relaxation and the secondary β-relaxation. The α-relaxation shows a non-Arrhenius temperature dependence and becomes faster with increasing concentration of water. The fragility of the solutions, determined by the temperature dependence of the α-relaxation close to the dynamic glass transition, decreases with increasing water content up to about 26 wt. % water, where ice starts to form. This decrease in fragility with increasing water content is most likely caused by the increasing density of hydrogen bonds, forming a network-like structure in the deeply supercooled regime. The intensity of the secondary β-relaxation of xylitol decreases noticeably already at a water content of 2 wt. %, and at a water content above 5 wt. % it has been replaced by a

  1. Adiabatic Heat of Hydration Calorimetric Measurements for Reference Saltstone Waste

    SciTech Connect

    Bollinger, James

    2006-01-12

    The production of nuclear materials for weapons, medical, and space applications from the mid-1950's through the late-1980's at the Savannah River Site (SRS) generated approximately 35 million gallons of liquid high-level radioactive waste, which is currently being processed into vitrified glass for long-term storage. Upstream of the vitrification process, the waste is separated into three components: high activity insoluble sludge, high activity insoluble salt, and very low activity soluble salts. The soluble salt represents 90% of the 35 million gallons of overall waste and is processed at the SRS Saltstone Facility, where it mixed with cement, blast furnace slag, and flyash, creating a grout-like mixture. The resulting grout is pumped into aboveground storage vaults, where it hydrates into concrete monoliths, called saltstone, thus immobilizing the low-level radioactive salt waste. As the saltstone hydrates, it generates heat that slowly diffuses out of the poured material. To ensure acceptable grout properties for disposal and immobilization of the salt waste, the grout temperature must not exceed 95 C during hydration. Adiabatic calorimetric measurements of the heat generated for a representative sample of saltstone were made to determine the time-dependent heat source term. These measurements subsequently were utilized as input to a numerical conjugate heat transfer model to determine the expected peak temperatures for the saltstone vaults.

  2. Calorimetric study of tellurium rich Se-Te-Sn glasses

    SciTech Connect

    Heera, Pawan; Kumar, Anup; Jharwal, Manish; Sharma, Raman

    2016-05-23

    We report the calorimetric study of amorphous Se{sub 30}Te{sub 70-x} Sn{sub x} alloys for x= 0, 1.5, 2.5, 4.5 in terms of kinetic parameters. The DSC curves recorded at four different heating rates are analyzed to determine the transition temperatures, activation energy, thermal stability, glass forming ability. The crystallization process has been investigated using Kissinger, Matusita, Augis and Bennett, and Gao and Wang models. Various kinetic parameters have been calculated for a better understanding of the growth mechanism. The glass transition temperatures T{sub g}, onset crystallization T{sub c}, peak crystallization T{sub p}, and melting temperature T{sub m} are found to increase with the increase in Sn content. The system under investigation is found to be thermally stable for at lower at% of Sn. The values of parameters H{sub R}, H{sub w}, and S indicate that Glass forming ability (GFA) decays with an increase in Sn content.

  3. Calorimetric measurements of energetics of defect interactions in fluorite oxides.

    PubMed

    Navrotsky, Alexandra; Simoncic, Petra; Yokokawa, Harumi; Chen, Weiqun; Lee, Theresa

    2007-01-01

    Direct measurement by oxide melt solution calorimetry of energetics of mixing in rare earth and yttrium doped zirconia, hafnia, and ceria systems provides support for spectroscopic and computational studies of the location and clustering of vacancies in these systems. Strongly negative heats of mixing are seen when the vacancy is transferred from being nearest neighbor to Y or RE in the sesquioxide to being nearest neighbor to Zr or Hf in the cubic solid solution. In the absence of such redistribution, small positive enthalpies of mixing are seen in CeO2-YO1.5 and CeO2-REO.15 systems. Strongly positive enthalpies of mixing are seen in CeO2-ZrO2, which has a large difference in cation sizes and no vacancy formation. The system Ce0.8Y0.2O1.9-Zr0.8Y0.2O1.9 shows small positive heats of formation with less destabilization in the Ce-rich region, suggestive of "scavenging" of oxygen vacancies by Zr. The calorimetric data obtained in these studies offer direct comparison with the results of computations on defect clusters and their binding energies.

  4. Calorimetric studies on the phenolic glycoside D(-)-salicin.

    PubMed

    Pinto, Susana S; Diogo, Hermínio P

    2008-12-01

    A pure orthorhombic phase sample of D(-)-salicin was purified and characterized for calorimetric measurements. From differential scanning calorimetry (DSC) measurements it was found that the onset and maximum temperatures of the fusion peak were T(on) = (473.30 +/- 0.05) K and T(max) = (474.74 +/- 0.05) K, respectively, and that the corresponding standard enthalpy of fusion was Delta(cr)(l) H(m)(o) = (55.5 +/- 0.4) kJ mol(-1). From the last two values the standard entropy of fusion is calculated as Delta(cr)(l) S(m)(o) = (116.9 +/- 0.4) J mol(-1) K(-1). The standard molar enthalpy of formation of orthorhombic D(-)-salicin at T = 298.15 K, was determined as Delta(f) H(m)(o) (C(13)H(18)O(7), cr, orthorhombic) = -(1366.9 +/- 3.2) kJ mol(-1), by combustion calorimetry. From the results of solution calorimetry obtained in this work and some auxiliary values taken from the literature the enthalpy of reaction of hydrolysis of D(-)-salicin to produce beta-glucose and o-hydroxybenzyl alcohol was found marginally thermoneutral, if the uncertainty interval was considered. Additionally, specific heat capacity measurements on the orthorhombic phase, glass and liquid-quenched glass obtained by DSC was reported.

  5. Calorimetric determination of surfactant/polyelectrolyte binding isotherms.

    PubMed

    Lapitsky, Yakov; Parikh, Maider; Kaler, Eric W

    2007-07-26

    Mixing of oppositely charged surfactants and polyelectrolytes in aqueous solutions leads to cooperative surfactant adsorption onto the polyelectrolyte chains. Experimental determination of surfactant/polyelectrolyte binding isotherms is usually done using custom-built surfactant-ion-specific electrodes. As an alternative, we present an indirect isotherm approximation method that uses conventional isothermal titration calorimetry (ITC). The calorimetric data is fitted to the two-binding-state Satake-Yang adsorption model, which quantifies the extent of binding in terms of the binding constant (Ku) and the cooperativity parameter (u). This approach is investigated using two surfactant/polyelectrolyte mixtures: sodium perfluorooctanoate (FC7) and N,N,N-trimethylammonium derivatized hydroxyethyl cellulose (UCARE Polymer JR-400), whose binding behavior follows the Satake-Yang model, and dodecyltrimethylammonium bromide (DTAB) and poly(styrenesulfonate) (NaPSS), whose behavior deviates dramatically from the Satake-Yang model. These studies demonstrate that, in order to apply the indirect ITC method of binding isotherm determination, the surfactant/polyelectrolyte adsorption process must have no more than two dominant binding states. Thus, the technique works well for the FC7/JR-400 mixture. It fails in the case of the DTAB/NaPSS adsorption, but its mode of failure offers insight into the multiple-binding-state adsorption mechanism.

  6. F-actin has a very high calorimetric unfolding enthalpy.

    PubMed

    Gicquaud, C R; Aubin, P H; Heppell, B; St-Gelais, F

    2005-08-19

    The thermal unfolding of F-actin was studied using differential scanning calorimetry. Heat denatures F-actin in two steps. The first is endothermic and corresponds to the unfolding of the peptide chain, while the second is exothermic and is due to the aggregation of the unfolded molecules. The aspect of the thermogram is influenced by the concentration of the protein. For concentrations around 1mg/ml, the steps are superimposed, while the two steps are separated at very low concentrations. It thus becomes possible to estimate the calorimetric enthalpy for the unfolding step. The enthalpy of unfolding is 64 MJ/mol, or 1400 J/g. This value is considerably higher than those mentioned in the literature for the denaturation of actin and other proteins, which are in the range of 25-30 J/g. The large amount of energy required to unfold the molecule of F-actin could be an adaptation of its role as a protein that transmits forces, and consequently must be very resistant to mechanical constraints.

  7. Neutron induced capture and fission discrimination using calorimetric shape decomposition

    NASA Astrophysics Data System (ADS)

    Carrapiço, C.; Berthoumieux, E.; Dridi, W.; Gonçalves, I. F.; Gunsing, F.; Lampoudis, C.; Vaz, P.; n TOF Collaboration

    2013-03-01

    The neutron capture and fission cross-sections of 233U have been measured at the neutron time-of-flight facility n_TOF at CERN in the energy range from 1 eV to 1 keV using a high performance 4π BaF2 Total Absorption Calorimeter (TAC) as a detection device. In order to separate the contributions of neutron capture and neutron induced fission in the TAC, a methodology called Calorimetric Shape Decomposition (CSD) was developed. The CSD methodology is based on the study of the TAC's energy response for all competing reactions, allowing to discriminate between γ s originating from neutron induced fission and those from neutron capture reactions without the need for fission tagging or any additional detection system. In this article, the concept behind the CSD is explained in detail together with the necessary analysis to obtain the TAC's response to neutron capture and neutron induced fission. The discrimination between capture and fission contributions is shown for several neutron energies. A comparison between the 233U neutron capture and fission yield extraction with ENDF/B-VII v1. library data is also provided.

  8. Absolute calorimetric calibration of low energy brachytherapy sources

    NASA Astrophysics Data System (ADS)

    Stump, Kurt E.

    In the past decade there has been a dramatic increase in the use of permanent radioactive source implants in the treatment of prostate cancer. A small radioactive source encapsulated in a titanium shell is used in this type of treatment. The radioisotopes used are generally 125I or 103Pd. Both of these isotopes have relatively short half-lives, 59.4 days and 16.99 days, respectively, and have low-energy emissions and a low dose rate. These factors make these sources well suited for this application, but the calibration of these sources poses significant metrological challenges. The current standard calibration technique involves the measurement of ionization in air to determine the source air-kerma strength. While this has proved to be an improvement over previous techniques, the method has been shown to be metrologically impure and may not be the ideal means of calbrating these sources. Calorimetric methods have long been viewed to be the most fundamental means of determining source strength for a radiation source. This is because calorimetry provides a direct measurement of source energy. However, due to the low energy and low power of the sources described above, current calorimetric methods are inadequate. This thesis presents work oriented toward developing novel methods to provide direct and absolute measurements of source power for low-energy low dose rate brachytherapy sources. The method is the first use of an actively temperature-controlled radiation absorber using the electrical substitution method to determine total contained source power of these sources. The instrument described operates at cryogenic temperatures. The method employed provides a direct measurement of source power. The work presented here is focused upon building a metrological foundation upon which to establish power-based calibrations of clinical-strength sources. To that end instrument performance has been assessed for these source strengths. The intent is to establish the limits of

  9. Neutron detection by measuring capture gammas in a calorimetric approach

    NASA Astrophysics Data System (ADS)

    Pausch, Guntram; Herbach, Claus-Michael; Kong, Yong; Lentering, Ralf; Plettner, Cristina; Roemer, Katja; Scherwinski, Falko; Stein, Juergen; Schotanus, Paul; Wilpert, Thomas

    2011-10-01

    The neutron capture detector (NCD) is introduced as a novel detection scheme for thermal and epithermal neutrons that could provide large-area neutron counters by using common detector materials and proven technologies. The NCD is based on the fact that neutron captures are usually followed by prompt gamma cascades, where the sum energy of the gammas equals to the total excitation energy of typically 6-9 MeV. This large sum energy is measured in a calorimetric approach and taken as the signature of a neutron capture event. An NCD consists of a neutron converter, comprising of constituents with large elemental neutron capture cross-section like cadmium or gadolinium, which is embedded in common scintillator material. The scintillator must be large and dense enough to absorb with reasonable probability a portion of the sum energy that exceeds the energy of gammas emitted by common (natural, medical, industrial) radiation sources. An energy window, advantageously complemented with a multiplicity filter, then discriminates neutron capture signals against background. The paper presents experimental results obtained at the cold-neutron beam of the BER II research reactor, Helmholtz-Zentrum Berlin, and at other neutron sources with a prototype NCD, consisting of four BGO crystals with embedded cadmium sheets, and with a benchmark configuration consisting of two separate NaI(Tl) detectors. The detector responses are in excellent agreement with predictions of a simulation model developed for optimizing NCD configurations. NCDs could be deployed as neutron detectors in radiation portal monitors (RPMs). Advanced modular scintillation detector systems could even combine neutron and gamma sensitivity with excellent background suppression at minimum overall expense.

  10. Finite size effects on calorimetric cooperativity of two-state proteins

    NASA Astrophysics Data System (ADS)

    Li, Mai Suan; Klimov, D. K.; Thirumalai, D.

    2005-05-01

    Finite size effects on the calorimetric cooperatity of the folding-unfolding transition in two-state proteins are considered using the Go lattice models with and without side chains. We show that for models without side chains a dimensionless measure of calorimetric cooperativity κ2 defined as the ratio of the van’t Hoff to calorimetric enthalpy does not depend on the number of amino acids N. The average value κ2bar≈{3}/{4} is lower than the experimental value κ2≈1. For models with side chains κ2 approaches unity as κ2∼Nμ, where μ≈0.17. Above the critical chain length Nc≈135 these models can mimic the truly all-or-non folding-unfolding transition.

  11. Calorimetric method for determination of {sup 51}Cr neutrino source activity

    SciTech Connect

    Veretenkin, E. P. Gavrin, V. N.; Danshin, S. N.; Ibragimova, T. V.; Kozlova, Yu. P.; Mirmov, I. N.

    2015-12-15

    Experimental study of nonstandard neutrino properties using high-intensity artificial neutrino sources requires the activity of the sources to be determined with high accuracy. In the BEST project, a calorimetric system for measurement of the activity of high-intensity (a few MCi) neutrino sources based on {sup 51}Cr with an accuracy of 0.5–1% is created. In the paper, the main factors affecting the accuracy of determining the neutrino source activity are discussed. The calorimetric system design and the calibration results using a thermal simulator of the source are presented.

  12. Heat capacty, relative enthalpy, and calorimetric entropy of silicate minerals: an empirical method of prediction.

    USGS Publications Warehouse

    Robinson, G.R.; Haas, J.L.

    1983-01-01

    Through the evaluation of experimental calorimetric data and estimates of the molar isobaric heat capacities, relative enthalpies and entropies of constituent oxides, a procedure for predicting the thermodynamic properties of silicates is developed. Estimates of the accuracy and precision of the technique and examples of its application are also presented. -J.A.Z.

  13. Steady state calorimetric measurement of total hemispherical emittance of cylindrical absorber samples at operating temperature

    NASA Astrophysics Data System (ADS)

    Effertz, Timo; Pernpeintner, Johannes; Schiricke, Björn

    2017-06-01

    At DLR's QUARZ Center a test bench has been established to measure, using steady state calorimetric method, the total hemispherical emittance of cylindrical solar thermal absorber samples at temperatures up to 450 °C. Emittance measurement of solar absorber surfaces is commonly performed by direct-hemispherical reflectance measurements with spectrophotometers. However, the measurement of cylindrical samples with spectrophotometers can be considered still a challenge as integrating spheres, reference samples and calibration services by national metrology institutions are optimized for flat sample measurement. Additionally samples are typically measured at room temperature. The steady state calorimetric method does not rely on reference samples and the measurement is performed at operating temperature. In the steady state calorimetric method electrical power input used to heat the sample is equated to the radiative heat loss from a heated sample to the environment. The total emittance can be calculated using the Stefan-Boltzmann equation from radiative heat loss power, the defined sample surface area and measured surface temperature. The expanded uncertainty (k=2) of the total hemispherical emittance has been determined to ±13 % for a typical parabolic trough absorber sample at a temperature of 300 °C and a heating power of 100 W. The test bench was validated by the measurement of three samples with the spectrophotometer and the steady state calorimetric method.

  14. Systematic uncertainties on Delta m2 from neutrino physics, using calorimetric energy reconstruction

    SciTech Connect

    Deborah A. Harris

    2003-08-13

    This report describes how uncertainties in neutrino interactions, particularly at neutrino energies of a few GeV, can contribute to uncertainties in measurements of neutrino oscillation parameters for experiments using calorimetric devices. Uncertainties studied include those on final state multiplicities, cross sections, electron-hadron calorimeter differences, and nuclear rescattering.

  15. A calorimetric system based on the LKB 10700-1 flow microcalorimeter

    NASA Astrophysics Data System (ADS)

    Leskiv, Miroslav; Bernardes, Carlos E. S.; Minas da Piedade, Manuel E.

    2009-07-01

    An electrically calibrated and computer-controlled apparatus based on the LKB 10700-1 flow microcalorimeter was set up and tested by determining the enthalpies of dilution of aqueous solutions of sucrose and HCl at 298.15 K. The obtained results are in good agreement with the corresponding reference values recommended in the literature. The quality of the calorimetric signal in terms of noise, linearity and baseline drift, and the instrument time constant were analyzed. Also investigated were the influences of the flow rate and of the viscosity of the calorimetric liquid on the position of the baseline. The new calibration system enables powers ~25 times smaller than those possible with the original one to be released inside the calorimetric cells. Electrical calibrations carried out with water as the sole calorimetric liquid indicated that the precision of the calibration constant, ɛ, quickly improved from ~9% to ~0.4% with the increase of the input power, P, from ~2 µW to ~50 µW, and stabilized at ~0.1% for P >= 100 µW. The calibration constant was also found to linearly increase with the flow rate of the calorimetric liquid and to vary by less than 1% over a period of eight months under similar experimental conditions. Finally a new experimental procedure for heat of dilution measurements, which combines calibration and experiment in a single run, was evaluated. This method allows a significant economy in experiment time with apparently no accuracy loss relative to the conventional procedure recommended in the literature.

  16. Le ciment brûle toujours

    PubMed Central

    Lebreton, T.; Fontaine, M.; Le Floch, R.

    2017-01-01

    Summary Les brûlures chimiques par ciment représentent une cause fréquente de corrosion cutanée en France. Elles nécessitent fréquemment un traitement chirurgical. Notre étude rétrospective concerne tous les patients admis pour une brûlure par ciment dans le service entre 2004 et 2016. Quarante-neuf patients âgés de 21 à 71 ans ont été pris en charge dans le centre des brûlés du Centre Hospitalier Saint Joseph Saint Luc à Lyon entre 2004 et 2016. La population concernée était majoritairement masculine, relativement jeune (44 ans en moyenne) et professionnellement active. Les brûlures survenaient principalement dans le cadre d’accidents domestiques (78%). Elles étaient profondes et atteignaient majoritairement les membres inférieurs, de façon bilatérale. La surface brûlée représentait 3% de la surface cutanée totale. Presque tous les patients (98%) ont nécessité une prise en charge chirurgicale pour excision et autogreffe de peau mince. Un seul patient a bénéficié d’une cicatrisation dirigée. Le délai moyen entre la brûlure et la chirurgie était de 13 jours et la durée moyenne d’hospitalisation de 8 jours. Sept patients ont nécessité une prise en charge en centre de rééducation à leur sortie du service. Cette étude confirme la sévérité des brûlures chimiques par ciment. Elle met également en avant l’impact que peut avoir ce type de brûlure en terme de retentissement socio-économique dans une population de patients majoritairement jeune et active. Elle insiste sur le fait que des mesures doivent être prises afin d’informer cette population rarement professionnelle sur les risques encourus lors du mésusage du ciment. La réglementation actuelle, classant le ciment comme irritant, ne prend pas en compte son caractère corrosif et devrait être amendée. PMID:28592929

  17. Calorimetric thermal-vacuum performance characterization of the BAe 80 K space cryocooler

    NASA Astrophysics Data System (ADS)

    Kotsubo, V. Y.; Johnson, D. L.; Ross, R. G., Jr.

    A comprehensive characterization program is underway at JPL to generate test data on long-life, miniature Stirling-cycle cryocoolers for space application. The key focus of this paper is on the thermal performance of the British Aerospace (BAe) 80 K split-Stirling-cycle cryocooler as measured in a unique calorimetric thermal-vacuum test chamber that accurately simulates the heat-transfer interfaces of space. Two separate cooling fluid loops provide precise individual control of the compressor and displacer heatsink temperatures. In addition, heatflow transducers enable calorimetric measurements of the heat rejected separately by the compressor and displacer. Cooler thermal performance has been mapped for coldtip temperatures ranging from below 45 K to above 150 K, for heatsink temperatures ranging from 280 K to 320 K, and for a wide variety of operational variables including compressor-displacer phase, compressor-displacer stroke, drive frequency, and piston-displacer dc offset.

  18. Monitoring Precipitation during Rapid Quenching of Aluminium Alloys by Calorimetric Reheating Experiments

    NASA Astrophysics Data System (ADS)

    Kessler, Olaf; Zohrabyan, Davit; Milkereit, Benjamin; Schick, Christoph

    Several age hardening aluminium alloys, like high alloyed 2XXX, 6XXX and 7XXX alloys require high critical quenching rates of some 100 K/s from solution annealing to suppress premature precipitation and achieve maximum strength after aging. Knowledge of the precipitation behaviour during quenching is crucial for the design of quenching processes of aluminium alloys. For monitoring the precipitation behaviour during moderate quenching, a calorimetric method (0.01 to 5 K/s) has already been successfully developed. New Differential Fast Scanning Calorimeters (DFSC, up to some 106 K/s) allow rapid quenching of aluminium alloys, but due to weak precipitation reactions the quenching results can hardly be evaluated. Hence, a new method has been developed, to monitor precipitation during rapid quenching of aluminium alloys by calorimetric reheating experiments. Quenching and reheating experiments of high alloyed, quench sensitive aluminium alloys, like 7049A will be presented.

  19. Calorimetric thermal-vacuum performance characterization of the BAe 80 K space cryocooler

    NASA Technical Reports Server (NTRS)

    Kotsubo, V. Y.; Johnson, D. L.; Ross, R. G., Jr.

    1992-01-01

    A comprehensive characterization program is underway at JPL to generate test data on long-life, miniature Stirling-cycle cryocoolers for space application. The key focus of this paper is on the thermal performance of the British Aerospace (BAe) 80 K split-Stirling-cycle cryocooler as measured in a unique calorimetric thermal-vacuum test chamber that accurately simulates the heat-transfer interfaces of space. Two separate cooling fluid loops provide precise individual control of the compressor and displacer heatsink temperatures. In addition, heatflow transducers enable calorimetric measurements of the heat rejected separately by the compressor and displacer. Cooler thermal performance has been mapped for coldtip temperatures ranging from below 45 K to above 150 K, for heatsink temperatures ranging from 280 K to 320 K, and for a wide variety of operational variables including compressor-displacer phase, compressor-displacer stroke, drive frequency, and piston-displacer dc offset.

  20. Comparing calorimetric and dielectric polarization modes in viscous 2-ethyl-1-hexanol.

    PubMed

    Huth, Heiko; Wang, Li-Min; Schick, Christoph; Richert, Ranko

    2007-03-14

    Dielectric relaxation and dynamic heat capacity measurements are compared for 2-ethyl-1-hexanol near its glass transition temperature Tg in order to further clarify the origin of the prominent Debye-type loss peak observed in many monohydroxy alcohols and other hydrogen-bonding liquids. While the dielectric spectrum epsilon" displays two distinct polarization processes that are separated by a factor of 2000 in terms of the peak frequency, the heat capacity cp" shows only a single peak. The dielectric process with lower amplitude and higher peak frequency coincides with the calorimetric signal, whereas the large dielectric Debye signal is not associated with calorimetric modes. The authors conclude that the Debye process corresponds to a transition among states which differ in energy only in the case of an external electric field.

  1. Constrained Methods in the Understanding of the Calorimetric Glass Transition in Simple Liquids.

    NASA Astrophysics Data System (ADS)

    Gonzalez Padilla, Francisco; Harrowell, Peter R.

    2001-03-01

    In spite of the intensive work and the important improvements in understanding the glass transition, the detailed microcopical behaviour and its thermodynamical implications are not understood yet. We will focus in the calorimetric glass transition, namely the non-monotonic variation of the specific heat with temperature. We will also be interested in recent suggestions that try to deal with the definition of an ideal glassy phase. We use different types of constrains to understand which degrees of freedom are important in understanding the calorimetric glass transition. We deal with geometrical constrain and with constrains obtain from the study of the hessian matrix. Indication on the importance of the anharmonicities to obtain a non-monotonic behaviour of the specific heat are obtained.

  2. Calorimetric thermal-vacuum performance characterization of the BAe 80 K space cryocooler

    NASA Technical Reports Server (NTRS)

    Kotsubo, V. Y.; Johnson, D. L.; Ross, R. G., Jr.

    1992-01-01

    A comprehensive characterization program is underway at JPL to generate test data on long-life, miniature Stirling-cycle cryocoolers for space application. The key focus of this paper is on the thermal performance of the British Aerospace (BAe) 80 K split-Stirling-cycle cryocooler as measured in a unique calorimetric thermal-vacuum test chamber that accurately simulates the heat-transfer interfaces of space. Two separate cooling fluid loops provide precise individual control of the compressor and displacer heatsink temperatures. In addition, heatflow transducers enable calorimetric measurements of the heat rejected separately by the compressor and displacer. Cooler thermal performance has been mapped for coldtip temperatures ranging from below 45 K to above 150 K, for heatsink temperatures ranging from 280 K to 320 K, and for a wide variety of operational variables including compressor-displacer phase, compressor-displacer stroke, drive frequency, and piston-displacer dc offset.

  3. An Improved Formulation for Calorimetric Emittance Testing of Spacecraft Thermal Control Coatings

    NASA Technical Reports Server (NTRS)

    Kauder, Lonny R.

    2008-01-01

    Spacecraft often really heavily on passive thermal control to maintain operating temperature. An important parameter in the spacecraft heat balance equation is the emittance of thermal control coatings as a function of coating temperature. One method for determining the emittance of spacecraft thermal control from elevated temperature to cryogenic temperatures relies on a calorimetric technique. The fundamental equation governing this test method can be found in numerous places in the literature and although it generally provides reasonable results, its formulation is based on a conceptual flaw that only becomes apparent when the sample temperature approaches the wall temperature during testing. This paper investigates the cause for this error and develops the correct formulation for calorimetric emittance testing. Experimental data will also be presented that illustrates the difference between the two formulations and the resulting difference in the calculated emittance.

  4. On the Stressing of Annealed NITINOL: The Electrical Resistance and Calorimetric Effects

    DTIC Science & Technology

    1987-04-01

    Security Classification) On the Stressing of Annealed NITINOL : The Electrical Resistance and Calorimetric Effects 12 PERSONAL AUTHOR(S) Goldstein, David...COSATI CODES 18 SUBJECT TERMS (Continue on reverse if necessary and identify by blck numbher) FIELD GROUP SUB-GROUP NITINOL 06 Shape Memory Alloy 13 o i...calorimetry curves of NITINOL during its phase transformation are substantial. The generation of a peak occurs in the resistance curve, and an additional

  5. Cathode cooling by expansion of hydrogen in calorimetric tests for cold fusion

    SciTech Connect

    Gammon, B.E. )

    1993-05-01

    Expansion of hydrogen and its isotopes from hydrogen-absorbing cathodes can transfer significant amounts of energy to the surrounding aqueous media. In calorimetric efforts to confirm cold fusion, allowance must be made for thermal conduction along electrical leads. In conjunction with consideration of the extent of cathode cooling by expansion of hydrogen, the rupturing of the cavities within the cathodes and limitations to charging of the electrode by hydrogen flowing from fresh cracks are briefly addressed. 11 refs., 1 tab.

  6. Ultra-Responsive Thermal Sensors for the Detection of Explosives Using Calorimetric Spectroscopy (CalSpec)

    SciTech Connect

    Datskos, P.G.; Datskou, I.; Marlar, T.A.; Rajic, S.

    1999-04-05

    We have developed a novel chemical detection technique based on infrared micro-calorimetric spectroscopy that can be used to identify the presence of trace amounts of very low vapor pressure target compounds. Unlike numerous recently developed low-cost sensor approaches, the selectivity is derived from the unique differential temperature spectrum and does not require the questionable reliability of highly selective coatings to achieve the required specificity. This is accomplished by obtaining the infrared micro-calorimetric absorption spectrum of a small number of molecules absorbed on the surface of a thermal detector after illumination through a scanning monochromator. We have obtained infrared micro-calorimetric spectra for explosives such as TNT over the wavelength region 2.5 to 14.5 Mu-m. Thus both sophisticated and relatively crude explosive compounds and components are detectable with these ultra-sensitive thermal-mechanical micro-structures. In addition to the above mentioned spectroscopy technique and associated data, the development of these advanced thermal detectors is also presented in detail.

  7. Calorimetric Measurements of Magnetic-Field-Induced Inhomogeneous Superconductivity Above the Paramagnetic Limit

    NASA Astrophysics Data System (ADS)

    Agosta, Charles C.; Fortune, Nathanael A.; Hannahs, Scott T.; Gu, Shuyao; Liang, Lucy; Park, Ju-Hyun; Schleuter, John A.

    2017-06-01

    We report the first magnetocaloric and calorimetric observations of a magnetic-field-induced phase transition within a superconducting state to the long-sought exotic Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superconducting state, first predicted over 50 years ago. Through the combination of bulk thermodynamic calorimetric and magnetocaloric measurements in the organic superconductor κ -(BEDT -TTF )2Cu (NCS )2 as a function of temperature, magnetic field strength, and magnetic field orientation, we establish for the first time that this field-induced first-order phase transition at the paramagnetic limit Hp is a transition to a higher-entropy superconducting phase, uniquely characteristic of the FFLO state. We also establish that this high-field superconducting state displays the bulk paramagnetic ordering of spin domains required of the FFLO state. These results rule out the alternate possibility of spin-density wave ordering in the high-field superconducting phase. The phase diagram determined from our measurements—including the observation of a phase transition into the FFLO phase at Hp—is in good agreement with recent NMR results and our own earlier tunnel-diode magnetic penetration depth experiments but is in disagreement with the only previous calorimetric report.

  8. Calorimetric Measurements of Magnetic-Field-Induced Inhomogeneous Superconductivity Above the Paramagnetic Limit.

    PubMed

    Agosta, Charles C; Fortune, Nathanael A; Hannahs, Scott T; Gu, Shuyao; Liang, Lucy; Park, Ju-Hyun; Schleuter, John A

    2017-06-30

    We report the first magnetocaloric and calorimetric observations of a magnetic-field-induced phase transition within a superconducting state to the long-sought exotic Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superconducting state, first predicted over 50 years ago. Through the combination of bulk thermodynamic calorimetric and magnetocaloric measurements in the organic superconductor κ-(BEDT-TTF)_{2}Cu(NCS)_{2} as a function of temperature, magnetic field strength, and magnetic field orientation, we establish for the first time that this field-induced first-order phase transition at the paramagnetic limit H_{p} is a transition to a higher-entropy superconducting phase, uniquely characteristic of the FFLO state. We also establish that this high-field superconducting state displays the bulk paramagnetic ordering of spin domains required of the FFLO state. These results rule out the alternate possibility of spin-density wave ordering in the high-field superconducting phase. The phase diagram determined from our measurements-including the observation of a phase transition into the FFLO phase at H_{p}-is in good agreement with recent NMR results and our own earlier tunnel-diode magnetic penetration depth experiments but is in disagreement with the only previous calorimetric report.

  9. Use of calorimetric assay for operational and accountability measurements of pure plutonium metal

    SciTech Connect

    Cremers, Teresa L; Sampson, Thomas E

    2010-01-01

    Plutonium pure metal products (PMP) are high purity plutonium metal items produced by electrorefining. The plutonium metal is produced as an approximately 3-kg ring. Accountability measurements for the electro-refining runs are typically balance/weight factor (incoming impure metal), chemistry (pure metal rings), and calorimetric assay or neutron counting of the crucibles and other wastes. The PMP items are qualified for their end use by extensive chemical assay. After PMP materials are made they are often sent to the vault for storage before being sent to the casting process, the next step in the production chain. The chemical assay of PMP items often takes a few weeks; however, before the metal items are allowed into the vault they must be measured. Non-destructive assay personnel measure the metals either by multiplicity neutron counting or calorimetric assay, depending on which instrument is available, thus generating comparisons between non-destructive assay and chemical assay. The suite of measurements, calorimetric assay, chemical assay, and neutron mUltiplicity counting is compared for a large group of PMP items.

  10. Calorimetric markers of Bence Jones and nonsecretory multiple myeloma serum proteome.

    PubMed

    Todinova, Svetla; Krumova, Sashka; Radoeva, Ralitsa; Gartcheva, Lidia; Taneva, Stefka G

    2014-12-16

    The present work provides a thermodynamic description of blood serum from patients diagnosed with Bence Jones myeloma (BJMM) and nonsecretory myeloma (NSMM) by means of differential scanning calorimetry (DSC), serum protein electrophoresis, and free light chain assay. Specific alterations in the thermodynamic behavior of both BJMM and NSMM proteome have been revealed. On the basis of the transition temperature of the main transition in the calorimetric profiles and the shape similarity criterion, we defined BJMM and NSMM sets/subsets of thermograms with very similar thermodynamic features. We show that some of the BJMM and NSMM subsets correlate with previously defined secretory myeloma subsets (Todinova et al. Anal. Chem. 2011, 83, 7992). The established analogies strongly suggest that common molecular markers contribute to the calorimetric profiles of the different, secretory and nonsecretory, myeloma types; our data show robust evidence that these are ligands stabilizing the major serum proteins. We demonstrate that the DSC approach might be highly beneficial, especially for NSMM patients, since the characteristic modifications in the DSC profiles might serve as calorimetric markers when no monoclonal proteins can be detected in the bloodstream and the diagnosis heavily relies on invasive methods.

  11. A calorimetric study of fatigue induced microstructural changes in aluminum alloy 7050

    NASA Astrophysics Data System (ADS)

    Papazian, J. M.; Deiasi, R. J.; Adler, P. N.

    1980-12-01

    Differential scanning calorimetry (DSC) was used to detect microstructural changes resulting from strain-controlled fatigue of aluminum alloy 7050. Two starting conditions were investigated: a GP zone T6X temper and an overaged T73651. The calorimetric signature of the microstructure was determined for samples that had been cycled either to failure or to preselected percentages of their expected lifetime at various strain amplitudes. Thermodynamic and kinetic analyses of the calorimetric results revealed a pronounced effect of plastic strain during fatigue on the reaction enthalpy and reaction kinetics of the GP zone dissolution peak of T6X, and a lesser effect on the η' dissolution peak of T73651. No microstructural changes after fatigue to failure in the nominally elastic strain regime were detected by DSC. The calorimetric results were uniform throughout the cross-section of the fatigue specimens. Based upon these results, it is concluded that approximately 75 pct of the GP zones initially present can be affected during low cycle fatigue, and that overaging of the GP zone microstructure does not occur. The results from the T73651 temper show that low cycle fatigue affects this overaged microstructure in a different manner. Reversion or disordering of η' does not occur, but some overaging was detected. It is suggested that the η' precipitate in this alloy is not shearable.

  12. Ultraresponsive thermal sensors for the detection of explosives using calorimetric spectroscopy (CalSpec)

    NASA Astrophysics Data System (ADS)

    Rajic, Slobodan; Datskos, Panos G.; Datskou, Irene; Marlar, Troy A.

    1999-08-01

    We have developed a novel chemical detection technique based on IR micro-calorimetric spectroscopy that can be used to identify the presence of trace amounts of very low vapor pressure target compounds. Unlike numerous recently developed low-cost sensor approaches, the selectivity is derived from the unique differential temperature spectrum and does not require the questionable reliability of highly selective coatings to achieve the required specificity. This is accomplished by obtaining the IR micro-calorimetric absorption spectrum of a small number of molecules absorbed on the surface of a thermal detector after illumination through a scanning monochromator. We have obtained IR micro- calorimetric spectra for explosives such as TNT over the wavelength region 2.5 to 14.5 micrometers . Thus both sophisticated and relatively crude explosives compounds and components are detectable with this technique due to the recent development of ultra sensitive thermal-mechanical micro-structures. In addition to the above mentioned spectroscopy technique and associated data, the development of these advanced thermal detectors is also presented in detail.

  13. Le Figaro. Revised.

    ERIC Educational Resources Information Center

    Crawford, Linda

    These instructional materials are designed for students with some French reading skills and vocabulary in late beginning or early intermediate senior high school French. The objectives are to introduce students to a French newspaper, "Le Figaro," and develop reading skills for skimming, gathering specific information, and relying on cognates. The…

  14. Le Indeterminacy in Spanish.

    ERIC Educational Resources Information Center

    Foster, David William

    The standard treatment of object pronouns in Latin American Spanish assigns a direct-object function to "lo" and "la" and an indirect-object function to "le." This study challenges this descriptive attribution in light of the contradictory and refractory evidence in Spanish morphosyntax. It is suggested that more…

  15. Calorimetric measurements of energy transfer efficiency and melting efficiency in CO sub 2 laser beam welding

    SciTech Connect

    Fuerschbach, P.W.

    1990-01-01

    Our previous calorimetric studies of weld melting efficiency and arc efficiency in the GTAW and PAW processes have naturally led us to speculate as to the magnitude of the efficiencies in the LBW process which to data have also not been adequately investigated. Most welding engineers that have had experience with the LBW process are acutely aware that the metals' absorptivity, the surface finish, and the laser wavelength, all play an important role in affecting the energy transfer efficiency, but the extent of their influence and our understanding of the influence of other process variables is not well understood. In addition, it is widely thought that only the LBW or EBW processes can be selected for applications where thermal damage and distortion from the welding process must be kept to a minimum. For these reasons, we have looked forward to performing these calorimetric experiments since they potentially can answer such important questions as: whether or not the melting efficiency of the LBW process is superior to that obtainable with conventional GTAW and PAW welding processes This study was prompted by poor production yields on switching device due to cracking of the ceramic header after final closure welding with the CO{sub 2} LBW process. This calorimetric study was begun in hopes of determining if allowed variations in production process control variables were responsible for increases in heat input and the resulting thermal stresses. By measuring the net heat input to the workpiece with the calorimeter and by measuring the laser output energy and the weld fusion zone size it was possible to determine the magnitudes of both the energy transfer efficiency and the melting efficiency as well as observe their dependence on the process variables. 3 refs.

  16. A reaction calorimetric investigation of the hydrogenation of a substituted pyrazine

    SciTech Connect

    Landau, R.N.; Singh, U.; Gortsema, F.

    1995-11-01

    Reaction calorimetry was the primary tool in investigations of the liquid-phase hydrogenation of a substituted pyrazine compound carried out over supported Pd catalysts. In addition to providing information about gas-liquid mass transfer limitations, calorimetric measurements provided a kinetic analysis of how product selectivity in this consecutive reaction network may be tuned by changing reaction conditions. Concentration profiles developed from fitting the heat flow data to a first-order model were compared with analytical measurements of concentration, demonstrating the utility of combining independent measurements of reaction progress as a means of assessing the validity of a kinetic model. 15 refs., 5 figs., 3 tabs.

  17. Calorimetric Measurement of the Plastic Vtork of Fatigue Crack Propagation in 4140 Steel

    NASA Astrophysics Data System (ADS)

    Gross, Todd S.; Weertman, Johannes

    1982-12-01

    A calorimetric technique has been developed for measurement of the effective surface energy of fatigue crack propagation, U, and the cyclic plastic work in the plastic zone, Q. The technique has several distinct advantages over existing methods. Measurements on 4140 steel (650 °C temper) show that U and Q are direct functions of the stress intensity factor, hK, and indirect functions of crack growth rate, daldN. Measurement of the change of U and Q after the application of a tensile overload supports this conclusion and provides strong evidence supporting crack closure theories.

  18. Relativistic electron precipitation at International Space Station: Space weather monitoring by Calorimetric Electron Telescope

    NASA Astrophysics Data System (ADS)

    Kataoka, Ryuho; Asaoka, Yoichi; Torii, Shoji; Terasawa, Toshio; Ozawa, Shunsuke; Tamura, Tadahisa; Shimizu, Yuki; Akaike, Yosui; Mori, Masaki

    2016-05-01

    The charge detector (CHD) of the Calorimetric Electron Telescope (CALET) on board the International Space Station (ISS) has a huge geometric factor for detecting MeV electrons and is sensitive to relativistic electron precipitation (REP) events. During the first 4 months, CALET CHD observed REP events mainly at the dusk to midnight sector near the plasmapause, where the trapped radiation belt electrons can be efficiently scattered by electromagnetic ion cyclotron (EMIC) waves. Here we show that interesting 5-20 s periodicity regularly exists during the REP events at ISS, which is useful to diagnose the wave-particle interactions associated with the nonlinear wave growth of EMIC-triggered emissions.

  19. Calorimetric measurement of the interaction of propylene, acetylene, and methane with dysprosium films at room temperature

    SciTech Connect

    Cerny, S.; Smutek, M. )

    1990-05-01

    Rare earth metals and their intermetallics have found applications in heterogeneous catalysis, including cracking, hydrogenation, and other reactions of hydrocarbons, yet little has been published on chemisorption of hydrocarbons by rare earths. In the present communication the authors report on exploratory calorimetric experiments with the adsorption of initial doses of C{sub 3}H{sub 6}, C{sub 2}H{sub 2}, and CH{sub 4} admitted to polycrystalline dysprosium films at room temperature. The obtained data are interpreted in terms of thermochemical cycles utilizing data of their previous thermochemical and XPS measurements of the interaction of hydrogen, carbon monoxide, and oxygen with films of rare earths.

  20. Method for measurement of diffusivity: Calorimetric studies of Fe/Ni multilayer thin films

    SciTech Connect

    Liu, JX; Barmak, K

    2015-07-15

    A calorimetric method for the measurement of diffusivity in thin film multilayers is introduced and applied to the Fe Ni system. Using this method, the diffusivity in [Fe (25 nm)/Ni (25 nm)](20) multilayer thin films is measured as 4 x 10(-3)exp(-1.6 +/- 0.1 eV/ k(B)T) cm(2)/s, respectively. The diffusion mechanism in the multilayers and its relevance to laboratory synthesis of L1(0) ordered FeNi are discussed. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. Le mouvement du pôle

    NASA Astrophysics Data System (ADS)

    Bizouard, Christian

    2012-03-01

    Les variations de la rotation terrestre. En conditionnant à la fois notre vie quotidienne, notre perception du ciel, et bon nombre de phénomènes géophysiques comme la formation des cyclones, la rotation de la Terre se trouve au croisement de plusieurs disciplines. Si le phenomena se faisait uniformément, le sujet serait vite discuté, mais c'est parce que la rotation terrestre varie, même imperceptiblement pour nos sens, dans sa vitesse angulaire comme dans la direction de son axe, qu'elle suscite un grand intérêt. D'abord pour des raisons pratiques : non seulement les aléas de la rotation terrestre modi_ent à la longue les pointés astrométriques à un instant donné de la journée mais in_uencent aussi les mesures opérées par les techniques spatiales ; en consequence l'exploitation de ces mesures, par exemple pour déterminer les orbites des satellites impliqués ou pratiquer le positionnement au sol, nécessite une connaissance précise de ces variations. Plus fondamentalement, elles traduisent les propriétés globales de la Terre comme les processus physiques qui s'y déroulent, si bien qu'en analysant les causes des fluctuations observées, on dispose d'un moyen de mieux connaître notre globe. La découverte progressive des fluctuations de la rotation de la Terre a une longue histoire. Sous l'angle des techniques d'observation, trois époques se pro-celle du pointé astrométrique à l'oeil nu, à l'aide d'instruments en bois ou métalliques (quart de cercle muraux par exemple). À partir du XVIIe siècle débute l'astrométrie télescopique dont les pointés sont complétés par des datations de plus en plus précises grâce à l'invention d'horloges régulées par balancier. Cette deuxième époque se termine vers 1960, avec l'avènement des techniques spatiales : les pointés astrométriques sont délaissés au profit de la mesure ultra-précise de durées ou de fréquences de signaux électromagnétiques, grâce à l'invention des horloges

  2. Calorimetric Thermoelectric Gas Sensor for the Detection of Hydrogen, Methane and Mixed Gases

    PubMed Central

    Park, Nam-Hee; Akamatsu, Takafumi; Itoh, Toshio; Izu, Noriya; Shin, Woosuck

    2014-01-01

    A novel miniaturized calorimeter-type sensor device with a dual-catalyst structure was fabricated by integrating different catalysts on the hot (Pd/θ-Al2O3) and cold (Pt/α-Al2O3) ends of the device. The device comprises a calorimeter with a thermoelectric gas sensor (calorimetric-TGS), combining catalytic combustion and thermoelectric technologies. Its response for a model fuel gas of hydrogen and methane was investigated with various combustor catalyst compositions. The calorimetric-TGS devices detected H2, CH4, and a mixture of the two with concentrations ranging between 200 and 2000 ppm at temperatures of 100–400 °C, in terms of the calorie content of the gases. It was necessary to reduce the much higher response voltage of the TGS to H2 compared to CH4. We enhanced the H2 combustion on the cold side so that the temperature differences and response voltages to H2 were reduced. The device response to H2 combustion was reduced by 50% by controlling the Pt concentration in the Pt/α-Al2O3 catalyst on the cold side to 3 wt%. PMID:24818660

  3. Determining the Neutrino Mass with a Calorimetric Low-Temperature Detector - The Experiment MARE

    NASA Astrophysics Data System (ADS)

    Kraft-Bermuth, S.

    2008-06-01

    In the light of the recent cosmological discussion, the direct measurement of the lightest neutrino mass from single β-decay has become an important issue. Calorimetric low-temperature detectors measure the temperature rise induced by the energy deposition of the β-electron in an absorber of low heat capacity. It has been demonstrated in the past that observing the β-decay spectrum of 187Re provides a suitable method to determine the mass of the electron anti-neutrino from β-endpoint measurements. In a first step, with the experiments MANU and MIBETA a sensitivity of mve ≤20 eV/c2 was achieved. To compete with the sensitivity of mve ≤ 0.2 eV/c2 aimed at with the KATRIN experiment, a new experiment MARE has been initiated. As a first stage, MARE-I will reach a sensitivity of mve ≤ 2 eV/c2. With 300 detectors mounted, systematic effects of the calorimetric approach will be studied in detail. The second stage MARE-II will consist of several 10000 detectors and aim at a sensitivity of mve ≤ 0.2 eV/c2.

  4. A Multichannel Calorimetric Simultaneous Assay Platform Using a Microampere Constant-Current Looped Enthalpy Sensor Array

    PubMed Central

    Wei, Hsien-Chin; Huang, Su-Hua; Jiang, Joe-Air; Lee, Yeun-Chung

    2017-01-01

    Calorimetric biochemical measurements offer various advantages such as low waste, low cost, low sample consumption, short operating time, and labor-savings. Multichannel calorimeters can enhance the possibility of performing higher-throughput biochemical measurements. An enthalpy sensor (ES) array is a key device in multichannel calorimeters. Most ES arrays use Wheatstone bridge amplifiers to condition the sensor signals, but such an approach is only suitable for null detection and low resistance sensors. To overcome these limitations, we have developed a multichannel calorimetric simultaneous assay (MCSA) platform. An adjustable microampere constant-current (AMCC) source was designed for exciting the ES array using a microampere current loop measurement circuit topology. The MCSA platform comprises a measurement unit, which contains a multichannel calorimeter and an automatic simultaneous injector, and a signal processing unit, which contains multiple ES signal conditioners and a data processor. This study focused on the construction of the MCSA platform; in particular, construction of the measurement circuit and calorimeter array in a single block. The performance of the platform, including current stability, temperature sensitivity and heat sensitivity, was evaluated. The sensor response time and calorimeter constants were given. The capability of the platform to detect relative enzyme activity was also demonstrated. The experimental results show that the proposed MCSA is a flexible and powerful biochemical measurement device with higher throughput than existing alternatives. PMID:28165412

  5. Comparison of the calorimetric and kinematic methods of neutrino energy reconstruction in disappearance experiments

    DOE PAGES

    Ankowski, Artur M.; Benhar, Omar; Coloma, Pilar; ...

    2015-10-22

    To be able to achieve their physics goals, future neutrino-oscillation experiments will need to reconstruct the neutrino energy with very high accuracy. In this work, we analyze how the energy reconstruction may be affected by realistic detection capabilities, such as energy resolutions, efficiencies, and thresholds. This allows us to estimate how well the detector performance needs to be determined a priori in order to avoid a sizable bias in the measurement of the relevant oscillation parameters. We compare the kinematic and calorimetric methods of energy reconstruction in the context of two νμ → νμ disappearance experiments operating in different energymore » regimes. For the calorimetric reconstruction method, we find that the detector performance has to be estimated with an O(10%) accuracy to avoid a significant bias in the extracted oscillation parameters. Thus, in the case of kinematic energy reconstruction, we observe that the results exhibit less sensitivity to an overestimation of the detector capabilities.« less

  6. Comparison of the calorimetric and kinematic methods of neutrino energy reconstruction in disappearance experiments

    SciTech Connect

    Ankowski, Artur M.; Benhar, Omar; Coloma, Pilar; Huber, Patrick; Jen, Chun -Min; Mariani, Camillo; Meloni, Davide; Vagnoni, Erica

    2015-10-22

    To be able to achieve their physics goals, future neutrino-oscillation experiments will need to reconstruct the neutrino energy with very high accuracy. In this work, we analyze how the energy reconstruction may be affected by realistic detection capabilities, such as energy resolutions, efficiencies, and thresholds. This allows us to estimate how well the detector performance needs to be determined a priori in order to avoid a sizable bias in the measurement of the relevant oscillation parameters. We compare the kinematic and calorimetric methods of energy reconstruction in the context of two νμ → νμ disappearance experiments operating in different energy regimes. For the calorimetric reconstruction method, we find that the detector performance has to be estimated with an O(10%) accuracy to avoid a significant bias in the extracted oscillation parameters. Thus, in the case of kinematic energy reconstruction, we observe that the results exhibit less sensitivity to an overestimation of the detector capabilities.

  7. Magnetic fluid hyperthermia probed by both calorimetric and dynamic hysteresis measurements

    NASA Astrophysics Data System (ADS)

    Guibert, Clément; Fresnais, Jérôme; Peyre, Véronique; Dupuis, Vincent

    2017-01-01

    In this paper, we report an investigation of magnetic fluid hyperthermia (MFH) using combined calorimetric and newly implemented dynamic hysteresis measurements for two sets of well characterized size-sorted maghemite nanoparticles (with diameters of about 10 nm and 20 nm) dispersed in water and in glycerol. Our primary goal was to assess the influence of viscosity on the heating efficiency of magnetic nanoparticles described in terms of specific loss power (SLP or specific absorption rate, SAR) and dynamic hysteresis. In particular, we aimed to investigate how this SLP depends on the transition from Néelian to Brownian behavior of nanoparticles expected to occur between 10 nm and 20 nm (for maghemite) and dependent on the viscosity. While we observed a good agreement between calorimetric and dynamic hysteresis measurements, we found that the SLP measured for the different systems do not depend noticeably on the viscosity of solvent. Calculations performed according to Rosensweig's linear model [1] allow us to quantitatively reproduce our results at low field intensities, provided we use a value for the magnetic anisotropy constant much smaller than the one commonly used in the literature. This raises the question of the temperature dependance of the magnetic anisotropy constant and its relevance for a quantitative description of MFH.

  8. Stabilization of Cu(I) for binding and calorimetric measurements in aqueous solution†

    PubMed Central

    Johnson, Destinee K.; Stevenson, Michael J.; Almadidy, Zayed A.; Jenkins, Sharon E.; Wilcox, Dean. E.; Grossoehme, Nicholas E.

    2015-01-01

    Conditions have been developed for the comproportionation reaction of Cu2+ and copper metal to prepare aqueous solutions of Cu+ that are stabilized from disproportionation by MeCN and other Cu+-stabilizing ligands. These solutions were then used in ITC measurements to quantify the thermodynamics of formation of a set of Cu+ complexes (CuI(MeCN)3+, CuIMe6Trien+, CuI(BCA)23−, CuI(BCS)23−), which have stabilities ranging over 15 orders of magnitude, for their use in binding and calorimetric measurements of Cu+ interaction with proteins and other biological macromolecules. These complexes were then used to determine the stability and thermodynamics of formation of a 1 : 1 complex of Cu+ with the biologically important tri-peptide glutathione, GSH. These results identify Me6Trien as an attractive Cu+-stabilizing ligand for calorimetric experiments, and suggest that caution should be used with MeCN to stabilize Cu+ due to its potential for participating in unquantifiable ternary interactions. PMID:26327397

  9. A Multichannel Calorimetric Simultaneous Assay Platform Using a Microampere Constant-Current Looped Enthalpy Sensor Array.

    PubMed

    Wei, Hsien-Chin; Huang, Su-Hua; Jiang, Joe-Air; Lee, Yeun-Chung

    2017-02-04

    Calorimetric biochemical measurements offer various advantages such as low waste, low cost, low sample consumption, short operating time, and labor-savings. Multichannel calorimeters can enhance the possibility of performing higher-throughput biochemical measurements. An enthalpy sensor (ES) array is a key device in multichannel calorimeters. Most ES arrays use Wheatstone bridge amplifiers to condition the sensor signals, but such an approach is only suitable for null detection and low resistance sensors. To overcome these limitations, we have developed a multichannel calorimetric simultaneous assay (MCSA) platform. An adjustable microampere constant-current (AMCC) source was designed for exciting the ES array using a microampere current loop measurement circuit topology. The MCSA platform comprises a measurement unit, which contains a multichannel calorimeter and an automatic simultaneous injector, and a signal processing unit, which contains multiple ES signal conditioners and a data processor. This study focused on the construction of the MCSA platform; in particular, construction of the measurement circuit and calorimeter array in a single block. The performance of the platform, including current stability, temperature sensitivity and heat sensitivity, was evaluated. The sensor response time and calorimeter constants were given. The capability of the platform to detect relative enzyme activity was also demonstrated. The experimental results show that the proposed MCSA is a flexible and powerful biochemical measurement device with higher throughput than existing alternatives.

  10. Calorimetric probe measurements for a high voltage pulsed substrate (PBII) in a HiPIMS process

    NASA Astrophysics Data System (ADS)

    Gauter, Sven; Fröhlich, Maik; Garkas, Wagdi; Polak, Martin; Kersten, Holger

    2017-06-01

    The combination of high-power impulse magentron sputtering (HiPIMS) and plasma based ion implantation (PBII) gives a versatile system which allows successive and simultaneous coating, doping or cleaning of a substrate surface in a single process. The delay between HiPIMS and PBII pulse is a critical parameter for the synchronization of the pulses as it defines at what time during the HiPIMS period the high voltage is applied to the substrate. To investigate the effect of this parameter on the energy flux towards the PBII substrate, VI-probe and calorimetric probe measurements were performed illustrating the effect of the delay for different PBII pulse durations and PBII voltages. The calorimetric measurements were performed utilizing a grid setup which allowed us to derive conclusions even when using a detector that is not at the PBII voltage. A maximum of electrical power and energy flux was observed for delay times significantly longer than the duration of the HiPIMS pulse. The investigation of different PBII pulse durations and PBII voltages confirmed that these parameters affect the absolute values of the energy flux and electrical power but do not significantly affect the transport of the ions as the PBII potential is shielded by a sheath.

  11. Calorimetric method of ac loss measurement in a rotating magnetic field.

    PubMed

    Ghoshal, P K; Coombs, T A; Campbell, A M

    2010-07-01

    A method is described for calorimetric ac-loss measurements of high-T(c) superconductors (HTS) at 80 K. It is based on a technique used at 4.2 K for conventional superconducting wires that allows an easy loss measurement in parallel or perpendicular external field orientation. This paper focuses on ac loss measurement setup and calibration in a rotating magnetic field. This experimental setup is to demonstrate measuring loss using a temperature rise method under the influence of a rotating magnetic field. The slight temperature increase of the sample in an ac-field is used as a measure of losses. The aim is to simulate the loss in rotating machines using HTS. This is a unique technique to measure total ac loss in HTS at power frequencies. The sample is mounted on to a cold finger extended from a liquid nitrogen heat exchanger (HEX). The thermal insulation between the HEX and sample is provided by a material of low thermal conductivity, and low eddy current heating sample holder in vacuum vessel. A temperature sensor and noninductive heater have been incorporated in the sample holder allowing a rapid sample change. The main part of the data is obtained in the calorimetric measurement is used for calibration. The focus is on the accuracy and calibrations required to predict the actual ac losses in HTS. This setup has the advantage of being able to measure the total ac loss under the influence of a continuous moving field as experienced by any rotating machines.

  12. Calorimetric method of ac loss measurement in a rotating magnetic field

    SciTech Connect

    Ghoshal, P. K.; Coombs, T. A.; Campbell, A. M.

    2010-07-15

    A method is described for calorimetric ac-loss measurements of high-T{sub c} superconductors (HTS) at 80 K. It is based on a technique used at 4.2 K for conventional superconducting wires that allows an easy loss measurement in parallel or perpendicular external field orientation. This paper focuses on ac loss measurement setup and calibration in a rotating magnetic field. This experimental setup is to demonstrate measuring loss using a temperature rise method under the influence of a rotating magnetic field. The slight temperature increase of the sample in an ac-field is used as a measure of losses. The aim is to simulate the loss in rotating machines using HTS. This is a unique technique to measure total ac loss in HTS at power frequencies. The sample is mounted on to a cold finger extended from a liquid nitrogen heat exchanger (HEX). The thermal insulation between the HEX and sample is provided by a material of low thermal conductivity, and low eddy current heating sample holder in vacuum vessel. A temperature sensor and noninductive heater have been incorporated in the sample holder allowing a rapid sample change. The main part of the data is obtained in the calorimetric measurement is used for calibration. The focus is on the accuracy and calibrations required to predict the actual ac losses in HTS. This setup has the advantage of being able to measure the total ac loss under the influence of a continuous moving field as experienced by any rotating machines.

  13. Calorimetric method of ac loss measurement in a rotating magnetic field

    NASA Astrophysics Data System (ADS)

    Ghoshal, P. K.; Coombs, T. A.; Campbell, A. M.

    2010-07-01

    A method is described for calorimetric ac-loss measurements of high-Tc superconductors (HTS) at 80 K. It is based on a technique used at 4.2 K for conventional superconducting wires that allows an easy loss measurement in parallel or perpendicular external field orientation. This paper focuses on ac loss measurement setup and calibration in a rotating magnetic field. This experimental setup is to demonstrate measuring loss using a temperature rise method under the influence of a rotating magnetic field. The slight temperature increase of the sample in an ac-field is used as a measure of losses. The aim is to simulate the loss in rotating machines using HTS. This is a unique technique to measure total ac loss in HTS at power frequencies. The sample is mounted on to a cold finger extended from a liquid nitrogen heat exchanger (HEX). The thermal insulation between the HEX and sample is provided by a material of low thermal conductivity, and low eddy current heating sample holder in vacuum vessel. A temperature sensor and noninductive heater have been incorporated in the sample holder allowing a rapid sample change. The main part of the data is obtained in the calorimetric measurement is used for calibration. The focus is on the accuracy and calibrations required to predict the actual ac losses in HTS. This setup has the advantage of being able to measure the total ac loss under the influence of a continuous moving field as experienced by any rotating machines.

  14. Calorimetric thermoelectric gas sensor for the detection of hydrogen, methane and mixed gases.

    PubMed

    Park, Nam-Hee; Akamatsu, Takafumi; Itoh, Toshio; Izu, Noriya; Shin, Woosuck

    2014-05-09

    A novel miniaturized calorimeter-type sensor device with a dual-catalyst structure was fabricated by integrating different catalysts on the hot (Pd/θ-Al2O3) and cold (Pt/α-Al2O3) ends of the device. The device comprises a calorimeter with a thermoelectric gas sensor (calorimetric-TGS), combining catalytic combustion and thermoelectric technologies. Its response for a model fuel gas of hydrogen and methane was investigated with various combustor catalyst compositions. The calorimetric-TGS devices detected H2, CH4, and a mixture of the two with concentrations ranging between 200 and 2000 ppm at temperatures of 100-400 °C, in terms of the calorie content of the gases. It was necessary to reduce the much higher response voltage of the TGS to H2 compared to CH4. We enhanced the H2 combustion on the cold side so that the temperature differences and response voltages to H2 were reduced. The device response to H2 combustion was reduced by 50% by controlling the Pt concentration in the Pt/α-Al2O3 catalyst on the cold side to 3 wt%.

  15. Thermodynamic Properties of Liquid Silver-Antimony-Tin Alloys Determined from Electrochemical and Calorimetric Measurements

    NASA Astrophysics Data System (ADS)

    Łapsa, Joanna; Onderka, Bogusław

    2016-08-01

    The thermodynamic properties of liquid Ag-Sb-Sn alloys were obtained through use of the drop solution calorimetric method and electromotive force (emf) measurements of galvanic cells with a yttria stabilized zirconia (YSZ) solid electrolyte. The experiments were carried out along Ag0.25Sb0.75, Ag0.5Sb0.5 and Ag0.75Sb0.25 sections of the ternary system in the temperature range from 973 K to 1223 K. From the measured emf, the tin activity in liquid solutions of Ag-Sb-Sn was determined for the first time. The partial and integral enthalpy of mixing were determined from calorimetric measurements at two temperatures. These measurements were performed along two cross-sections: Sb0.5Sn0.5 at 912 K and 1075 K, and Ag0.75Sb0.25 at 1075 K. Both experimental data sets were used to find ternary interaction parameters by applying the Redlich-Kister-Muggianu model of the substitutional solution. Consequently, the set of parameters describing the thermodynamic properties of the liquid phase was derived.

  16. Streptococcus pneumoniae, le transformiste.

    PubMed

    Johnston, Calum; Campo, Nathalie; Bergé, Matthieu J; Polard, Patrice; Claverys, Jean-Pierre

    2014-03-01

    Streptococcus pneumoniae (the pneumococcus) is an important human pathogen. Natural genetic transformation, which was discovered in this species, involves internalization of exogenous single-stranded DNA and its incorporation into the chromosome. It allows acquisition of pathogenicity islands and antibiotic resistance and promotes vaccine escape via capsule switching. This opinion article discusses how recent advances regarding several facets of pneumococcal transformation support the view that the process has evolved to maximize plasticity potential in this species, making the pneumococcus le transformiste of the bacterial kingdom and providing an advantage in the constant struggle between this pathogen and its host.

  17. Emittance characterization of thermal control paints, coatings and surfaces using a calorimetric technique

    NASA Astrophysics Data System (ADS)

    Jaworske, Donald A.

    1994-12-01

    Thermal control surfaces are used in every spacecraft thermal management system to dissipate heat through radiant heat transfer. This paper describes the thermal performance of several thermal control paints, coatings, and surfaces, as characterized by a calorimetric vacuum emissometer. The emissometer is designed to measure the functional emittance of a surface based on heat transfer from an underlying substrate to the surface and from the surface or near surface to a surrounding cold wall. Emittance measurements were made between 200 and 350 K. Polished aluminum, used here as a standard, was found to have a total hemispherical emittance of 0.06, as expected. A velvet black paint, also used here as a standard, was found to have an emittance of 0.94 at room temperature. Other surfaces of interest included a polyurethane-based black paint designated Z-306, a highly polished 316L stainless steel, and an atomic oxygen beam-textured carbon-carbon composite.

  18. Direct calorimetric verification of thermodynamic instability of lead halide hybrid perovskites.

    PubMed

    Nagabhushana, G P; Shivaramaiah, Radha; Navrotsky, Alexandra

    2016-07-12

    Hybrid perovskites, especially methylammonium lead iodide (MAPbI3), exhibit excellent solar power conversion efficiencies. However, their application is plagued by poor chemical and structural stability. Using direct calorimetric measurement of heats of formation, MAPbI3 is shown to be thermodynamically unstable with respect to decomposition to lead iodide and methylammonium iodide, even in the absence of ambient air or light or heat-induced defects, thus limiting its long-term use in devices. The formation enthalpy from binary halide components becomes less favorable in the order MAPbCl3, MAPbBr3, MAPbI3, with only the chloride having a negative heat of formation. Optimizing the geometric match of constituents as measured by the Goldschmidt tolerance factor provides a potentially quantifiable thermodynamic guide for seeking chemical substitutions to enhance stability.

  19. Calorimetric study on the effect of 60Co γ-rays on the growth of microorganisms

    NASA Astrophysics Data System (ADS)

    Wirkner, Sandra; Takahashi, Katsutada; Furuta, Masakazu; Hayashi, Toshio

    2002-03-01

    Using a calorimeter equipped with 24 sample units, the heat evolution from growing Saccharomyces cerevisiae, Escherichia coli and spores of Bacillus pumilus and Bacillus stearothermophilus was detected in the form of growth thermograms. Irradiation with 60Co γ-rays affected the growth pattern, which was used for a quantitative analysis of the effect on microorganisms. Irradiation of B. pumilus and B. stearothermophilus spores led to dose-dependent delays in growth, indicating a bactericidal effect. In case of 60Co γ-irradiated S. cerevisiae, a dose-dependent reduction of the growth rate constant was observed together with the retardation in growth, indicating a combination of bactericidal and bacteriostatic effects. An equation to determine the number of survivors on the basis of the retardation in growth tα and the growth rate constant μ was developed, which proved the opportunity to use the calorimetric technique in predictive microbiology.

  20. Direct calorimetric verification of thermodynamic instability of lead halide hybrid perovskites

    PubMed Central

    Nagabhushana, G. P.; Shivaramaiah, Radha; Navrotsky, Alexandra

    2016-01-01

    Hybrid perovskites, especially methylammonium lead iodide (MAPbI3), exhibit excellent solar power conversion efficiencies. However, their application is plagued by poor chemical and structural stability. Using direct calorimetric measurement of heats of formation, MAPbI3 is shown to be thermodynamically unstable with respect to decomposition to lead iodide and methylammonium iodide, even in the absence of ambient air or light or heat-induced defects, thus limiting its long-term use in devices. The formation enthalpy from binary halide components becomes less favorable in the order MAPbCl3, MAPbBr3, MAPbI3, with only the chloride having a negative heat of formation. Optimizing the geometric match of constituents as measured by the Goldschmidt tolerance factor provides a potentially quantifiable thermodynamic guide for seeking chemical substitutions to enhance stability. PMID:27357677

  1. Emittance characterization of thermal control paints, coatings and surfaces using a calorimetric technique

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.

    1994-01-01

    Thermal control surfaces are used in every spacecraft thermal management system to dissipate heat through radiant heat transfer. This paper describes the thermal performance of several thermal control paints, coatings, and surfaces, as characterized by a calorimetric vacuum emissometer. The emissometer is designed to measure the functional emittance of a surface based on heat transfer from an underlying substrate to the surface and from the surface or near surface to a surrounding cold wall. Emittance measurements were made between 200 and 350 K. Polished aluminum, used here as a standard, was found to have a total hemispherical emittance of 0.06, as expected. A velvet black paint, also used here as a standard, was found to have an emittance of 0.94 at room temperature. Other surfaces of interest included a polyurethane-based black paint designated Z-306, a highly polished 316L stainless steel, and an atomic oxygen beam-textured carbon-carbon composite.

  2. Comment on "Binding of alkaloid harmalol to DNA: photophysical and calorimetric approach".

    PubMed

    Alomar, Maria L; Gonzalez, M Micaela; Erra-Balsells, Rosa; Cabrerizo, Franco M

    2014-07-05

    The present manuscript is a comment on the article entitled "Binding of alkaloid harmalol to DNA: Photophysical and calorimetric approach" by Sarita Sarkar and Kakali Bhadra (2014) [1]. In their article, the authors reported the chemical structure as well as the absorption spectra of harmalol at different pH. On the bases of the previous publications and our own present results, the assignment of the number of the acid-base species and the corresponding pKa values, as well as the chemical structure for each species are erroneous. These facts have strong effect on the conclusions reached by the authors, in terms of the interaction with DNA. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Rapid discrimination of DNA strands using an opto-calorimetric microcantilever sensor.

    PubMed

    Lee, Dongkyu; Hwang, Kyo Seon; Kim, Seonghwan; Thundat, Thomas

    2014-12-21

    A rapid technique for quantitative detection and discrimination of DNA strands without using immobilized probe molecules is demonstrated using an opto-calorimetric, self-powered sensor based on a Pb(Zr(0.52)Ti(0.48))O3 (PZT) microcantilever. Microcalorimetric infrared (IR) spectroscopy provides excellent chemical selectivity based on the unique molecular vibrational characteristics of each nucleotide in the mid IR region. The piezoelectric and pyroelectric properties of the PZT microcantilever were exploited in the quantitative detection and discrimination of adsorbed DNA strands with their spectral characteristics. We report the unique spectral characteristics of different DNA nucleotides that are monitored by wavelength-dependent temperature variations for different relative molar ratio of each nucleotide. This approach offers a fast, label-free technique which is highly sensitive and selective for the detection of single nucleotide differences in DNA strands and has the potential to be used as a rapid prescreening biosensor for various biomolecules.

  4. Evidence of secondary electron emission during PIII pulses as measured by calorimetric probe

    NASA Astrophysics Data System (ADS)

    Haase, Fabian; Manova, Darina; Mändl, Stephan; Kersten, Holger

    2016-09-01

    Secondary electrons are an ubiquitous nuisance during plasma immersion ion implantation (PIII) necessitating excessive current supplies and shielding for X-rays generated by them. However, additional effects - especially at low pulse voltages - can include interactions with the plasma and transient increases in the plasma density. Here, it is shown that the transient thermal flux associated with secondary electrons emitted from the pulsed substrate can be directly measured using a passive calorimetric probe mounted near the chamber wall away from the pulsed substrate holder. A small increase of a directed energy flux from the substrate towards the probe is consistently observed on top of the isotropic flux from the plasma surrounding the probe, scaling with pulse frequency, pulse voltage, pulse length - as well as depending on gas and substrate material. A strong correlation between voltage and substrate-probe distance is observed, which should allow further investigation of low energy electrons with the plasma itself.

  5. Calorimetric Observation of Single {He}_2^* Excimers in a 100-mK He Bath

    NASA Astrophysics Data System (ADS)

    Carter, F. W.; Hertel, S. A.; Rooks, M. J.; McClintock, P. V. E.; McKinsey, D. N.; Prober, D. E.

    2017-02-01

    We report the first calorimetric detection of individual {He}_2^* excimers within a bath of superfluid ^4{He}. The detector used in this work is a single superconducting titanium transition edge sensor (TES) with an energy resolution of {˜ }1 {eV}, immersed directly in the helium bath. {He}_2^* excimers are produced in the surrounding bath using an external gamma-ray source. These excimers exist either as short-lived singlet or long-lived triplet states. We demonstrate detection (and discrimination) of both states: In the singlet case the calorimeter records the absorption of a prompt {≈ }15 {eV} photon, and in the triplet case the calorimeter records a direct interaction of the molecule with the TES surface, which deposits a distinct fraction of the {≈ }15 {eV}, released upon decay, into the surface. We also briefly discuss the detector fabrication and characterization.

  6. Total hemispherical emittance measured at high temperatures by the calorimetric method

    SciTech Connect

    DiFilippo, F.; Mirtich, M.J.; Banks, B.A.; Stidham, C.; Kussmaul, M.

    1994-09-01

    A calorimetric vacuum emissometer (CVE) capable of measuring total hemispherical emittance of surfaces at elevated temperatures was designed, built, and tested. Several materials with a wide range of emittances were measured in the CVE between 773 to 923 K. These results were compared to values calculated from spectral emittance curves measured in a room temperature Hohlraum reflectometer and in an open-air elevated temperature emissometer. The results differed by as much as 0.2 for some materials but were in closer agreement for the more highly-emitting, diffuse-reflecting samples. The differences were attributed to temperature, atmospheric, and directional effects, and errors in the Hohlraum and emissometer measurements ({+-} 5 percent). The probable error of the CVE measurements was typically less than 1 percent.

  7. Total hemispherical emittance measured at high temperatures by the calorimetric method

    NASA Technical Reports Server (NTRS)

    Difilippo, Frank; Mirtich, Michael J.; Banks, Bruce A.; Stidham, Curtis; Kussmaul, Michael

    1989-01-01

    A calorimetric vacuum emissometer (CVE) capable of measuring total hemispherical emittance of surfaces at elevated temperatures was designed, built, and tested. Several materials with a wide range of emittances were measured in the CVE between 773 to 923 K. These results were compared to values calculated from spectral emittance curves measured in a room temperature Hohlraum reflectometer and in an open-air elevated temperature emissometer. The results differed by as much as 0.2 for some materials but were in closer agreement for the more highly-emitting, diffuse-reflecting samples. The differences were attributed to temperature, atmospheric, and directional effects, and errors in the Hohlraum and emissometer measurements (plus or minus 5 percent). The probable error of the CVE measurements was typically less than 1 percent.

  8. Transport and calorimetric studies on CeNi2Al3

    NASA Astrophysics Data System (ADS)

    Y, Sankararao; Shanmukharao Samatham, S.; D, Venkateshwarlu; Gangrade, Mohan; Ganesan, V.

    2014-09-01

    Transport and calorimetric properties of Kondo lattice system CeNi2Al3 are reported. CeNi2Al3 shows good agreement with Grand Kadowaki-Woods relation with degeneracy of the quasi-particle N=6. The nonmagnetic nature of CeNi2Al3 is evident from resistivity measurement even though magnetic elements Ce and Ni are present. Three signatures, deviation from the normal metallic behaviour in resistivity above 140 K, relatively low charge carrier concentration (1021 cm-3) and energy gap Eg~11.6 meV obtained from two band model shed light on the most basic notions related to the semimetal nature of CeNi2Al3.

  9. Interaction of vasicine with calf thymus DNA: Molecular docking, spectroscopic and differential scanning calorimetric insights

    NASA Astrophysics Data System (ADS)

    R. S., Sai Murali; R. S., Sai Siddhardha; Rajesh Babu, D.; Venketesh, S.; Basavaraju, R.; Nageswara Rao, G.

    2017-06-01

    The present study brings out the interaction between vasicine, an alkaloid and Adhatoda vasica Nees with double stranded DNA. The physico-chemical interaction between small molecules and nucleic acids is a major area of focus in screening drugs against various cancers. Molecular probing in our study using Molecular Operating Environment (MOE) has revealed interaction of vasicine with DNA double helix. Here we report the interaction of vasicine with Calf thymus DNA. We present for the first time the results obtained from UV-visible, fluorescence spectroscopic and differential scanning calorimetric techniques that suggest a moderate to strong electrostatic, hydrophobic and van der Waals interactions mediating the DNA binding properties of vasicine, leading to disruption of DNA secondary structure.

  10. Biodegradable composites filled with halloysite nanonotubes: Calorimetric investigations and structural issues

    NASA Astrophysics Data System (ADS)

    Russo, Pietro; Vetrano, Barbara; Acierno, Domenico

    2012-07-01

    Halloysite nanotubes were dispersed in a commercially biodegradable blends by melt compounding. Bionanocomposites based on a film-grade commercial blend of poly(hydroxybutirate)-co-valerate PHBV and poly(butylene adipate-co-therephthalate) PBAT and containg up to 10% by weigth of tubular clays (HNTs) were prepared by using a twin-screw lab extruder and filmed by a film-blowing equipment. Film samples were subjected to thermal and structural investigations. Calorimetric analysis showed that signals shape is clearly affected by the heating and cooling rate, respectively. Structural investigations performed by X-Ray diffraction tests satisfactorily allowed to interpret thermal behavior highlighting the occurrence of different crystalline modifications, depending on the scanning thermal rate, the inclusion of filler and its chemical functionalization.

  11. Calorimetric Determinations of the Heat and Products of Detonation for Explosives: October 1961 to April 1982

    NASA Astrophysics Data System (ADS)

    Ornellas, D. L.

    1982-04-01

    This report is a compilation of heat-of-detonation and product-composition data obtained at Lawrence Livermore National Laboratory during the last 21 years. In each determination, a 25-g high-explosive charge was detonated in a bomb calorimeter; a complete calorimetric measurement was made in 1 to 2 h with a precision of 0.3%. Data were interpreted using thermodynamic and hydrodynamic computer calculations. For unconfined or lightly confined charges, the released energy is largely retained in the products, which are subsequently shocked considerably off the Chapman-Jouguet isentrope by reflections from the bomb wall. For heavily confined charges, the detonation energy is largely converted to kinetic and internal energy of the confining case, and the products expand with minimal reshock along the Chapman-Jouguet isentrope.

  12. Calorimetric quantification of linked equilibria in cyclodextrin/lipid/detergent mixtures for membrane-protein reconstitution.

    PubMed

    Textor, Martin; Vargas, Carolyn; Keller, Sandro

    2015-04-01

    Reconstitution from detergent micelles into lipid bilayer membranes is a prerequisite for many in vitro studies on purified membrane proteins. Complexation by cyclodextrins offers an efficient and tightly controllable way of removing detergents for membrane-protein reconstitution, since cyclodextrins sequester detergents at defined stoichiometries and with tuneable affinities. To fully exploit the potential advantages of cyclodextrin for membrane-protein reconstitution, we establish a quantitative model for predicting the supramolecular transition from mixed micelles to vesicles during cyclodextrin-mediated detergent extraction. The model is based on a set of linked equilibria among all pseudophases present in the course of the reconstitution process. Various isothermal titration-calorimetric protocols are used for quantifying a detergent's self-association as well as its colloidal and stoichiometric interactions with lipid and cyclodextrin, respectively. The detergent's critical micellar concentration, the phase boundaries in the lipid/detergent phase diagram, and the dissociation constant of the cyclodextrin/detergent complex thus obtained provide all thermodynamic parameters necessary for a quantitative prediction of the transition from micelles to bilayer membranes during cyclodextrin-driven reconstitution. This is exemplified and validated by stepwise complexation of the detergent lauryldimethylamine N-oxide in mixtures with the phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine upon titration with 2-hydroxypropyl-β-cyclodextrin, both in the presence and in the absence of the membrane protein Mistic. The calorimetric approach presented herein quantitatively predicts the onset and completion of the reconstitution process, thus obviating cumbersome trial-and-error efforts and facilitating the rational optimisation of reconstitution protocols, and can be adapted to different cyclodextrin/lipid/detergent combinations. Copyright © 2015 Elsevier Inc

  13. Calorimetric calibration of head coil SAR estimates displayed on a clinical MR scanner.

    PubMed

    Gorny, Krzysztof R; Bernstein, Matt A; Felmlee, Joel P; Ward, Heidi A; McGee, Kiaran P; Lanners, Diana M; Lee, Kendall H

    2008-05-21

    Calorimetric measurements were performed to determine the average specific absorption rates (SAR) resulting from MRI head examinations. The data were compared with average head coil SAR estimates displayed by the MR scanner in order to refine the imaging protocols used in imaging patients with implanted deep brain stimulators (DBS). The experiments were performed using transmit-receive (TR) head coil on clinical 1.5 T General Electric MR scanners running 11.0 M4 revision software. The average applied SAR was derived from temperature increases measured inside a head phantom, due to deposition of RF energy during MRI scanning with a spin echo imaging sequence. The measurements were repeated for varied levels of RF transmit gain (TG) and analyzed with a range of entered patient weights. The measurements demonstrate that the ratio of the actual average head SAR to the scanner-displayed value (coil correction factor) decreases for decreasing TG or for increasing patient weight and may vary between 0.3 and 2.1. An additional retrospective patient study, however, shows that not all combinations of TG and patient weight are encountered clinically and, instead, TG generally increases with the patient weight. As a result, a much narrower range of coil correction factors (e.g., typically 0.5-1.0) will be encountered in practice. The calorimetric method described in this work could aid the physicians and technologists in refinement of the model-dependent SAR estimates displayed by the MR scanner, and in selection of imaging parameters for MR head examinations within allowable SAR safety levels.

  14. Calorimetric studies of ligands binding to glutathione S-transferase from the malarial parasite Plasmodium falciparum.

    PubMed

    Quesada-Soriano, Indalecio; Barón, Carmen; García-Maroto, Federico; Aguilera, Ana M; García-Fuentes, Luís

    2013-03-19

    Glutathione S-transferase, from the malarial parasite Plasmodium falciparum (PfGST), exerts a protective role in the organism and is thus considered an interesting target for antimalarial drug development. In contrast to other GSTs, it is present in solution as a tetramer and a dimer in equilibrium, which is induced by glutathione (GSH). These properties prevent a calorimetric titration from being conducted upon binding of ligands to this protein's G-site. Thermodynamic characterization can be an optimal strategy for antimalarial drug development, and isothermal titration calorimetry (ITC) is the only technique that allows the separation of the binding energy into both enthalpic and entropic contributions. This information facilitates an understanding of the changes in the drugs' substituents, improving their affinity and specificity. In this study, we have applied a nontypical ITC procedure, based on the dissociation of the ligand-protein complex, to calorimetrically study the binding of the GSH substrate, and the glutathione sulfonate competitive inhibitor, to dimeric PfGST over a temperature range of 15-37 °C. The optimal experimental conditions for applying this procedure have been optimized by studying the dimer to tetramer conversion using size exclusion chromatography. The binding of these ligands to dimeric PfGST is noncooperative, the affinity of glutathione sulfonate being approximately 2 orders of magnitude higher than that of its natural substrate GSH. The binding of both ligands is enthalpically favorable and entropically unfavorable at all the studied temperatures. These results demonstrate that, although PfGST presents differences when compared to other known GSTs, these ligands bind to its dimeric form with a similar affinity and energetic balance. However, in contrast to that of other GSTs, the binding of GSH to protein, in the absence of the ligand, is slow.

  15. NEP facilities (LeRC)

    NASA Technical Reports Server (NTRS)

    Vetrone, Robert H.

    1993-01-01

    The topics are presented in viewgraph form and include the following: the Electric Propulsion Research Building (no. 16) the Electric Power Laboratory (BLDG. 301); the Tank 6 Vacuum Facility; and test facilities for electric propulsion and LeRC.

  16. Le bégaiement

    PubMed Central

    Perez, Hector R.; Stoeckle, James H.

    2016-01-01

    Résumé Objectif Fournir une mise à jour sur l’épidémiologie, l’hérédité, la physiopathologie, le diagnostic et le traitement du bégaiement développemental. Qualité des données Une recherche d’études récentes ou non portant sur l’épidémiologie, l’hérédité, la physiopathologie, le diagnostic et le traitement du bégaiement développemental a été effectuée dans les bases de données MEDLINE et Cochrane. La plupart des recommandations s’appuient sur des études de petite envergure, des données probantes de qualité limitée ou des consensus. Message principal Le bégaiement est un trouble d’élocution fréquent chez les personnes de tous âges, il altère la fluidité verbale normale et l’enchaînement du discours. Le bégaiement a été lié à des différences de l’anatomie, du fonctionnement et de la régulation dopaminergique du cerveau qui seraient de source génétique. Il importe de poser le diagnostic avec attention et de faire les recommandations qui conviennent chez les enfants, car de plus en plus, le consensus veut que l’intervention précoce par un traitement d’orthophonie soit cruciale chez les enfants bègues. Chez les adultes, le bégaiement est lié à une morbidité psychosociale substantielle, dont l’anxiété sociale et une piètre qualité de vie. Les traitements pharmacologiques ont soulevé l’intérêt depuis quelques années, mais les données cliniques sont limitées. Le traitement des enfants et des adultes repose sur l’orthophonie. Conclusion De plus en plus de recherches ont tenté de lever le voile sur la physiopathologie du bégaiement. La meilleure solution pour les enfants et les adultes bègues demeure la recommandation à un traitement d’orthophonie.

  17. Effect of Temperature on Xylanase II from Trichoderma reesei QM 9414: A Calorimetric, Catalytic, and Conformational Study

    PubMed Central

    López, Gloria

    2014-01-01

    The secondary structure of xylanase II from Trichoderma reesei is lost in an apparent irreversible cooperative process as temperature is increased with a midpoint transition of 58.8 ± 0.1°C. The shift of the spectral centre of mass above 50°C is also apparently cooperative with midpoint transition of 56.3 ± 0.2°C, but the existence of two isofluorescent points in the fluorescence emission spectra suggests a non-two-state process. Further corroboration comes from differential scanning calorimetry experiments. At protein concentrations ≤0.56 mg·mL−1 the calorimetric transition is reversible and the data were fitted to a non-two-state model and deconvoluted into six transitions, whereas at concentrations greater than 0.56 mg·mL−1 the calorimetric transition is irreversible with an exothermic contribution to the thermogram. The apparent Tm increased linearly with the scan rate according to first order inactivation kinetics. The effect of additives on the calorimetric transition of xylanase is dependent on their nature. The addition of sorbitol transforms reversible transitions into irreversible transitions while stabilizing the protein as the apparent Tm increases linearly with sorbitol concentration. d-Glucono-1,5-lactone, a noncompetitive inhibitor in xylanase kinetics, and soluble xylan change irreversible processes into reversible processes at high protein concentration. PMID:25276420

  18. Calorimetric low temperature detectors for low-energetic heavy ions and their application in accelerator mass spectrometry.

    PubMed

    Kraft-Bermuth, S; Andrianov, V A; Bleile, A; Echler, A; Egelhof, P; Kiseleva, A; Kiselev, O; Meier, H J; Meier, J P; Shrivastava, A; Weber, M; Golser, R; Kutschera, W; Priller, A; Steier, P; Vockenhuber, C

    2009-10-01

    The energy-sensitive detection of heavy ions with calorimetric low temperature detectors was investigated in the energy range of E=0.1-1 MeV/amu, commonly used for accelerator mass spectrometry (AMS). The detectors used consist of sapphire absorbers and superconducting aluminum transition edge thermometers operated at T approximately 1.5 K. They were irradiated with various ion beams (13C, 197Au, 238U) provided by the VERA tandem accelerator in Vienna, Austria. The relative energy resolution obtained was DeltaE/E=(5-9) x 10(-3), even for the heaviest ions such as 238U. In addition, no evidence for a pulse height defect was observed. This performance allowed for the first time to apply a calorimetric low temperature detector in an AMS experiment. The aim was to precisely determine the isotope ratio of 236U/238U for several samples of natural uranium, 236U being known as a sensitive monitor for neutron fluxes. Replacing a conventionally used detection system at VERA by the calorimetric detector enabled to substantially reduce background from neighboring isotopes and to increase the detection efficiency. Due to the high sensitivity achieved, a value of 236U/238U=6.1 x 10(-12) could be obtained, representing the smallest 236U/238U ratio measured at the time. In addition, we contributed to establishing an improved material standard of 236U/238U, which can be used as a reference for future AMS measurements.

  19. Differential scanning calorimetric evaluation of human meibomian gland secretions and model lipid mixtures: transition temperatures and cooperativity of melting

    PubMed Central

    Lu, Hua; Wojtowicz, Jadwiga C.; Butovich, Igor A.

    2013-01-01

    Meibomian gland secretions (or meibum) are produced by holocrine meibomian glands and are secreted in melted form onto the ocular surface of humans and animals to form a protective tear film lipid layer (TFLL). Its protective effect strongly depends on the composition and, hence, thermotropic behavior of meibum. The goal of our study was to quantitatively evaluate the melting characteristics of human meibum and model lipid mixtures using differential scanning microcalorimetry. Standard calorimetric parameters, e.g. changes in calorimetric enthalpy, transition temperatures T(m), cooperativity of melting etc. were assessed. We found that thermotropic behavior of meibum resembled that of relatively simple mixtures of unsaturated wax esters, but showed a lower change in calorimetric enthalpy, which can be indicative of a looser packing of lipids in meibum compared with pure standards and their simple mixtures. The cooperativity of melting of meibomian lipids was comparable to that of an equimolar mixture of four oleic-acid based wax esters. We demonstrated that the phase transitions in meibum start at about 10 to 15 °C and end at 35-36 °C, with T(m) being about 30 °C. The highly asymmetrical shape of the thermotropic peak of meibum is important for the physiology and biophysics of TFLL. PMID:23578711

  20. Calorimetric studies on the thermal hazard of methyl ethyl ketone peroxide with incompatible substances.

    PubMed

    Chang, Ron-Hsin; Shu, Chi-Min; Duh, Yih-Shing; Jehng, Jih-Mirn

    2007-03-22

    In Taiwan, Japan, and China, methyl ethyl ketone peroxide (MEKPO) has caused many severe thermal explosions owing to its thermal instability and reactivity originating from the complexity of its structure. This study focused on the incompatible features of MEKPO as detected by calorimetry. The thermal decomposition and runaway behaviors of MEKPO with about 10wt.% incompatibilities, such as H(2)SO(4), HCl, NaOH, KOH, FeCl(3), and FeSO(4), were analyzed by dynamic calorimeter, differential scanning calorimetry (DSC) and adiabatic calorimeter, vent sizing package 2 (VSP2). Thermokinetic data, such as onset temperature, heat of decomposition, adiabatic temperature rise, and self-heat rate, were obtained and assessed. Experimental data were used for determining the incompatibility rating on hazards. From the thermal curves of MEKPO with assumed incompatible substances detected by DSC, all the onset temperatures in the other tests occurring earlier advanced, especially with alkaline or ferric materials. In some tests, significant incompatible reactions were found. Adiabatic runaway behaviors for simulating the worst case scenario were performed by using VSP2. These calorimetric data led to the same results that the alkaline or ferric solution was the most incompatible with MEKPO.

  1. Thermal explosion analysis of methyl ethyl ketone peroxide by non-isothermal and isothermal calorimetric applications.

    PubMed

    Chi, Jen-Hao; Wu, Sheng-Hung; Shu, Chi-Min

    2009-11-15

    In the past, process incidents attributed to organic peroxides (OPs) that involved near misses, over-pressures, runaway reactions, and thermal explosions occurred because of poor training, human error, incorrect kinetic assumptions, insufficient change management, and inadequate chemical knowledge in the manufacturing process. Calorimetric applications were employed broadly to test organic peroxides on a small-scale because of their thermal hazards, such as exothermic behavior and self-accelerating decomposition in the laboratory. In essence, methyl ethyl ketone peroxide (MEKPO) is highly reactive and exothermically unstable. In recent years, it has undergone many thermal explosions and runaway reaction incidents in the manufacturing process. Differential scanning calorimetry (DSC), vent sizing package 2 (VSP2), and thermal activity monitor (TAM) were employed to analyze thermokinetic parameters and safety index. The intent of the analyses was to facilitate the use of various auto-alarm equipments to detect over-pressure, over-temperature, and hazardous materials leaks for a wide spectrum of operations. Results indicated that MEKPO decomposition is detected at low temperatures (30-40 degrees C), and the rate of decomposition was shown to exponentially increase with temperature and pressure. Determining time to maximum rate (TMR), self-accelerating decomposition temperature (SADT), maximum temperature (T(max)), exothermic onset temperature (T(0)), and heat of decomposition (DeltaH(d)) was essential for identifying early-stage runaway reactions effectively for industries.

  2. Short-pulse Calorimetric Load for High Power Millimeter-wave Beams

    NASA Astrophysics Data System (ADS)

    Gandini, F.; Bruschi, A.; Cirant, S.; Gittini, G.; Granucci, G.; Muzzini, V.; Sozzi, C.; Spinicchia, N.

    2007-02-01

    A spherical compact matched load, for high vacuum operation suited for short pulses (2 MW, 0.1 s) precise measurement has been designed to test high power gyrotrons Bruschi, Gandini, Muzzini, Spinicchia, Cirant, Gittini, Granucci, Mellera, Nardone, Simonetto, and Sozzi (Fusion Eng. Des. 56 57:649 654, 2001); Bruschi, Cirant, Gandini, Granucci, Mellera, Muzzini, Nardone, Simonetto, Sozzi, and Spinicchia (Nucl. Fusion 43:1513 1519, 2003); Bruschi, Cirant, Gandini, Gittini, Granucci, Mellera, Muzzini, Nardone, Simonetto, Sozzi, Spinicchia, Angella, and Signorelli (Development of CW and short-pulse calorimetric loads for high power millimeter-wave Beams, 23rd Symposium on Fusion Technology, September 20 24, 2004, Venice, Italy). In order to enhance the power handling capability of the load and to reduce the operation problems that may arise from an excessive reflection from the load, a ray tracing code has been written to model the power distribution on the inner surface and the pattern of the reflected radiation. The outcome of this code has been used to select a more convenient profile for the spreading mirror of the load and to optimize a pre-load specially conceived to minimize the power reflected fraction.

  3. Systematic study of packaging designs on the performance of CMOS thermoresistive micro calorimetric flow sensors

    NASA Astrophysics Data System (ADS)

    Xu, Wei; Pan, Liang; Gao, Bo; Chiu, Yi; Xu, Kun; Lee, Yi-Kuen

    2017-08-01

    We systematically study the effect of two packaging configurations for the CMOS thermoresistive micro calorimetric flow (TMCF) sensors: S-type with the sensor chip protrusion-mounted on the flow channel wall and E-type with the sensor chip flush-mounted on the flow channel wall. Although the experimental results indicated that the sensitivity of the S-type was increased by more than 30%; the corresponding flow range as compared to the E-type was dramatically reduced by 60% from 0-11 m s-1 to 0-4.5 m s-1. Comprehensive 2D CFD simulation and in-house developed 3D numerical simulations based on the gas-kinetic scheme were applied to study the flow separation of these two packaging designs with the major parameters. Indeed, the S-type design with the large protrusion would change the local convective heat transfer of the TMCF sensor and dramatically decrease the sensors’ performance. In addition, parametric CFD simulations of the packaging designs provide inspiration to propose a novel general flow regime map (FRM), i.e. normalized protrusion d * versus reduced chip Reynolds number Re*, where the critical boundary curve for the flow separation of TMCF sensors was determined at different channel aspect ratios. The proposed FRM can be a useful guideline for the packaging design and manufacturing of different micro thermal flow sensors.

  4. Electron energy and charge albedos - calorimetric measurement vs Monte Carlo theory

    SciTech Connect

    Lockwood, G.J.; Ruggles, L.E.; Miller, G.H.; Halbleib, J.A.

    1981-11-01

    A new calorimetric method has been employed to obtain saturated electron energy albedos for Be, C, Al, Ti, Mo, Ta, U, and UO/sub 2/ over the range of incident energies from 0.1 to 1.0 MeV. The technique was so designed to permit the simultaneous measurement of saturated charge albedos. In the cases of C, Al, Ta, and U the measurements were extended down to about 0.025 MeV. The angle of incidence was varied from 0/sup 0/ (normal) to 75/sup 0/ in steps of 15/sup 0/, with selected measurements at 82.5/sup 0/ in Be and C. In each case, state-of-the-art predictions were obtained from a Monte Carlo model. The generally good agreement between theory and experiment over this extensive parameter space represents a strong validation of both the theoretical model and the new experimental method. Nevertheless, certain discrepancies at low incident energies, especially in high-atomic-number materials, and at all energies in the case of the U energy albedos are not completely understood.

  5. A calorimetric investigation of the growth of the luminescent bacteria Beneckea harveyi and Photobacterium leiognathi.

    PubMed

    McIlvaine, P; Langerman, N

    1977-01-01

    Direct calorimetric determinations of the rate of heat production along with simultaneous determinations of the rate of photon emission and the number of viable cells have provided insight into the growth of Beneckea harveyi and Photobacterium leiognathi. These experiments were performed with a Tronac isothermal microcalorimeter modified with a fiber optic light guide to allow in situ detection of light. Escherichia coli and a dark variant of P. leiognathi were also examined to provide points of reference. It is demonstrated that B. harveyi seems to pause in the rate of metabolic heat production at the same point in time that the enzyme luciferase begins to be synthesized. This effect is not removed if B. harveyi is grown in conditioned medium. The thermograms for all species are correlated with cell generation time. The heat production per cell indicates that uncrowded cultures produce more heat than older, more crowded cultures, supporting the original observation of Bayne-Jones and Rhees (1929). These observations reopen for examination the suggestion that living systems tend toward a state of minimum metabolism per unit mass.

  6. Minor groove binding of the food colorant carmoisine to DNA: spectroscopic and calorimetric characterization studies.

    PubMed

    Basu, Anirban; Kumar, Gopinatha Suresh

    2014-01-08

    The interaction of the food additive carmoisine with herring testes DNA was studied by multifaceted biophysical techniques. Carmoisine exhibited hypochromic effects in absorbance, whereas in fluorescence the intensity enhanced upon complexation with DNA. Energy transfer from the DNA base pairs to carmoisine molecules occurred upon complexation. A groove binding model of interaction was envisaged for carmoisine-DNA complexation from 4',6-diamidino-2-phenylindole (DAPI) and Hoechst displacement studies. The binding of carmoisine stabilized the DNA structure against thermal denaturation. The binding induced moderate conformational perturbations in the B-form structure of DNA. The binding affinity (10(4) M(-1)) values, calculated from absorbance and fluorescence data, and calorimetry titrations were in close agreement with each other. The binding was characterized to be exothermic and favored by small negative enthalpic and large positive entropic contributions. Salt-dependent calorimetric studies revealed that the binding reaction was dominated by nonpolyelectrolytic forces. The negative heat capacity value suggested the role of hydrophobic effect in the interaction.

  7. Optical and Calorimetric Studies of Cholesterol-Rich Filamentous, Helical Ribbon and Crystal Microstructures (abstract)

    NASA Astrophysics Data System (ADS)

    Miroshnikova, Y. A.; Elsenbeck, M.; Kashuri, K.; Iannacchione, G. S.; Zastavker, Y. V.

    2009-04-01

    Formation of biological self-assemblies at all scales is a focus of studies in fields ranging from biology to physics to biomimetics. Understanding the physico-chemical properties of these self-assemblies may lead to the design of bio-inspired structures and technological applications. Here we examine self-assembled filamentous, helical ribbon, and crystal microstructures formed in chemically defined lipid concentrate (CDLC), a model system for cholesterol crystallization in gallbladder bile. CDLC consists of cholesterol, bilayer-forming amphiphiles, micelle-forming amphiphiles, and water. Phase contrast and differential interference contrast (DIC) microscopy indicate the presence of three microstructure types in all samples studied, and allow for an investigation of the structures' unique geometries. Additionally, confocal microscopy is used for qualitative assessment of surface and internal composition. To complement optical observations, calorimetric (differential-scanning and modulation) experiments, provide the basis for an in-depth understanding of collective and individual thermal behavior. Observed ``transition'' features indicate clustering and ``straightening'' of helical ribbons into short, increasingly thickening, filaments that dissolve with increasing temperature. These results suggest that all microstructures formed in CDLC may coexist in a metastable chemical equilibrium. Further investigation of the CDLC thermal profile should uncover the process of cholesterol crystallization as well as the unique design and function of microstructures formed in this system.

  8. 3D modeling and characterization of a calorimetric flow rate sensor for sweat rate sensing applications

    NASA Astrophysics Data System (ADS)

    Iftekhar, Ahmed Tashfin; Ho, Jenny Che-Ting; Mellinger, Axel; Kaya, Tolga

    2017-03-01

    Sweat-based physiological monitoring has been intensively explored in the last decade with the hopes of developing real-time hydration monitoring devices. Although the content of sweat (electrolytes, lactate, urea, etc.) provides significant information about the physiology, it is also very important to know the rate of sweat at the time of sweat content measurements because the sweat rate is known to alter the concentrations of sweat compounds. We developed a calorimetric based flow rate sensor using PolydimethylSiloxane that is suitable for sweat rate applications. Our simple approach on using temperature-based flow rate detection can easily be adapted to multiple sweat collection and analysis devices. Moreover, we have developed a 3D finite element analysis model of the device using COMSOL Multiphysics™ and verified the flow rate measurements. The experiment investigated flow rate values from 0.3 μl/min up to 2.1 ml/min, which covers the human sweat rate range (0.5 μl/min-10 μl/min). The 3D model simulations and analytical model calculations covered an even wider range in order to understand the main physical mechanisms of the device. With a verified 3D model, different environmental heat conditions could be further studied to shed light on the physiology of the sweat rate.

  9. Calorimetric studies of the ammonia-water system with application to the outer solar system

    NASA Technical Reports Server (NTRS)

    Yarger, Jeffery; Lunine, Jonathan I.; Burke, Michael

    1993-01-01

    A series of heating experiments was performed on the condensed ammonia-water system using a differential scanning calorimeter (DSC). The water-rich samples were cooled quickly to below 130 K, then heated at a variety of rates. Rather than a single peritectic melt at 176 K, expected for the equilibrium system of water ice and ammonia dihydrate, four enthalpic transitions were repeatedly seen in the temperature range 150-176 K. These transitions are generally consistent with the earlier calorimetric results of Van Kasteren (1973), who interpreted the lowest temperature exotherm as crystallization of an amorphous ammonia-water compound formed during cooling. We propose that both sets of experiments are seeing the crystallization of ammonia monohydrate, which is metastable relative to the dihydrate, followed by partial remelting and crystallization of dihydrate upon further heating. The apparent stability of the monohydrate in the dihydrate equilibrium field implies a potentially complex behavior of ammonia-water ices in satellites. Possible self-heating of the mixture by several tens of degrees up to the 170 K eutectic could make mobilization of ammonia-water liquids in icy satellite interiors energetically easier than previously thought.

  10. Calorimetric studies and lessons on fires and explosions of a chemical plant producing CHP and DCPO.

    PubMed

    Hsu, Jing-Ming; Su, Mao-Sheng; Huang, Chiao-Ying; Duh, Yih-Shing

    2012-05-30

    Cumene hydroperoxide (CHP) has been used in producing phenol, dicumyl peroxide (DCPO) and as an initiator for synthesizing acrylonitrile-butadiene-styrene (ABS) resin by copolymerization in Taiwan. Four incidents of fire and explosion induced by thermal runaway reactions were occurred in a same plant producing CHP, DCPO and bis-(tert-butylperoxy isopropyl) benzene peroxide (BIBP). The fourth fire and explosion occurred in the CHP reactor that resulted in a catastrophic damage in reaction region and even spread throughout storage area. Descriptions on the occurrences of these incidents were assessed by the features of processes, reaction schemes and unexpected side reactions. Calorimetric data on thermokinetics and pressure were used for explaining the practical consequences or which the worst cases encountered in this kind of plant. Acceptable risk associated with emergency relief system design is vital for a plant producing organic peroxide. These basic data for designing an inherently safer plant can be conducted from adiabatic calorimetry. An encouraging deduction has been drawn here, these incidents may be avoided by the implementation of API RP 520, API RP 521, DIERS technology, OSHA 1910.119 and AIChE's CCPS recommended PSM elements.

  11. A calorimetric-based comparison of gas tungsten and plasma arc welding processes

    SciTech Connect

    Knorovsky, G.A.; Fuerschbach, P.W.

    1988-01-01

    Measurements of arc and melting efficiencies have been made for pulsed and continuous mode Gas Tungsten Arc Welding (GTAW) and Plasma Arc Welding (PAW) processes. Welds were made on 2.5 mm total thickness pure Ni and 304 Stainless Steel in a standing edge weld geometry at constant nominal machine output settings which varied average current with travel speed. Under continuous current conditions, the measured heat input remained approximately constant for the conditions examined (250-1250 mm/min), while melting efficiency increased dramatically (0-/approximately/0.4). Arc efficiencies were relatively constant, remaining in the range of /approximately/0.75-0.85 for GTAW and somewhat less for PAW. Values of melting efficiency for Ni were slightly less than those for 304 when compared at similar travel speeds, though both tended toward the same limit (/approximately/0.4). The PAW results were not appreciably higher than the GTAW. In addition to melting efficiency the centerline depth of penetration was also measured. In contrast to the GTAW results, which increased with speed at lower travel speeds and then plateaued at 0.8 mm, the PAW results increased monotonically with speed to a maximum of 1.0 mm. In conclusion, calorimetric measurements of nonconsumable arc welding processes have been found helpful in understanding conditions under which efficient arc welds with minimal heat inputs for a desired weld penetration can be made. 10 figs.

  12. Optical and Calorimetric Studies of Cholesterol-Rich Filamentous, Helical Ribbon and Crystal Microstructures

    SciTech Connect

    Miroshnikova, Y. A.; Elsenbeck, M.; Zastavker, Y. V.; Kashuri, K; Iannacchione, G. S.

    2009-04-19

    Formation of biological self-assemblies at all scales is a focus of studies in fields ranging from biology to physics to biomimetics. Understanding the physico-chemical properties of these self-assemblies may lead to the design of bio-inspired structures and technological applications. Here we examine self-assembled filamentous, helical ribbon, and crystal microstructures formed in chemically defined lipid concentrate (CDLC), a model system for cholesterol crystallization in gallbladder bile. CDLC consists of cholesterol, bilayer-forming amphiphiles, micelle-forming amphiphiles, and water. Phase contrast and differential interference contrast (DIC) microscopy indicate the presence of three microstructure types in all samples studied, and allow for an investigation of the structures' unique geometries. Additionally, confocal microscopy is used for qualitative assessment of surface and internal composition. To complement optical observations, calorimetric (differential-scanning and modulation) experiments, provide the basis for an in-depth understanding of collective and individual thermal behavior. Observed ''transition'' features indicate clustering and ''straightening'' of helical ribbons into short, increasingly thickening, filaments that dissolve with increasing temperature. These results suggest that all microstructures formed in CDLC may coexist in a metastable chemical equilibrium. Further investigation of the CDLC thermal profile should uncover the process of cholesterol crystallization as well as the unique design and function of microstructures formed in this system.

  13. Calorimetric studies of the role of magnesium ions in yeast enolase catalysis.

    PubMed

    Faller, L D; Johnson, A M

    1974-04-01

    The binding of magnesium ions and of the competitive inhibitor 3-phospho-D-glyceric acid to yeast enolase (2-phospho-D-glycerate hydrolyase, EC 4.2.1.11) has been studied calorimetrically. Thermal titration of the apoprotein with magnesium ions provides evidence that two magnesium ions bind immeasurably tightly to the dimeric enzyme, either anticooperatively to interacting sites or to two independent, nonidentical sites. Measurements of the saturation heat in buffers with different enthalpies of protonation are consistent with the release of two protons when the metal-binding sites are filled at pH 7.5. The enthalpy of binding of the two magnesium ions, corrected for the release of two protons, is +11.7 kcal (+49.0 kJ) per mole of dimeric protein. Thermal titration of the magnesium-saturated enzyme with 3-phosphoglyceric acid corroborates the conclusion of Spring and Wold [Biochemistry (1971) 10, 4655-4660] that the enolase dimer possesses two equivalent and independent substrate-binding sites. The dissociation constant for the enzyme-inhibitor complex calculated from the thermal data is 2 mM. The thermal studies of 3-phosphoglyceric acid binding also confirm that metal ions are required for substrate binding and that substrate binds at the two specific metal-binding sites on the apoprotein. Experiments in buffers with different enthalpies of ionization provide evidence for proton uptake when 3-phosphoglyceric acid is bound.

  14. Status and performance of the CALorimetric Electron Telescope (CALET) on the International Space Station

    NASA Astrophysics Data System (ADS)

    Adriani, O.; Akaike, Y.; Asaoka, Y.; Asano, K.; Bagliesi, M. G.; Bigongiari, G.; Binns, W. R.; Bongi, M.; Buckley, J. H.; Cassese, A.; Castellini, G.; Cherry, M. L.; Collazuol, G.; Ebisawa, K.; Di Felice, V.; Fuke, H.; Guzik, T. G.; Hams, T.; Hasebe, N.; Hareyama, M.; Hibino, K.; Ichimura, M.; Ioka, K.; Israel, M. H.; Javaid, A.; Kamioka, E.; Kasahara, K.; Katayose, Y.; Kataoka, J.; Kataoka, R.; Kawanaka, N.; Kitamura, H.; Kotani, T.; Krawczynski, H. S.; Krizmanic, J. F.; Kubota, A.; Kuramata, S.; Lomtadze, T.; Maestro, P.; Marcelli, L.; Marrocchesi, P. S.; Mitchell, J. W.; Miyake, S.; Mizutani, K.; Motz, H. M.; Moiseev, A. A.; Mori, K.; Mori, M.; Mori, N.; Munakata, K.; Murakami, H.; Nakagawa, Y. E.; Nakahira, S.; Nishimura, J.; Okuno, S.; Ormes, J. F.; Ozawa, S.; Palma, F.; Papini, P.; Rauch, B. F.; Ricciarini, S.; Sakamoto, T.; Sasaki, M.; Shibata, M.; Shimizu, Y.; Shiomi, A.; Sparvoli, R.; Spillantini, P.; Takahashi, I.; Takayanagi, M.; Takita, M.; Tamura, T.; Tateyama, N.; Terasawa, T.; Tomida, H.; Torii, S.; Tunesada, Y.; Uchihori, Y.; Ueno, S.; Vannuccini, E.; Wefel, J. P.; Yamaoka, K.; Yanagita, S.; Yoshida, A.; Yoshida, K.; Yuda, T.

    2014-11-01

    The CALorimetric Electron Telescope (CALET) space experiment, currently under development by Japan in collaboration with Italy and the United States, will measure the flux of cosmic-ray electrons (including positrons) to 20 TeV, gamma rays to 10 TeV and nuclei with Z=1 to 40 up to 1,000 TeV during a two-year mission on the International Space Station (ISS), extendable to five years. These measurements are essential to search for dark matter signatures, investigate the mechanism of cosmic-ray acceleration and propagation in the Galaxy and discover possible astrophysical sources of high-energy electrons nearby the Earth. The instrument consists of two layers of segmented plastic scintillators for the cosmic-ray charge identification (CHD), a 3 radiation length thick tungsten-scintillating fiber imaging calorimeter (IMC) and a 27 radiation length thick lead-tungstate calorimeter (TASC). CALET has sufficient depth, imaging capabilities and excellent energy resolution to allow for a clear separation between hadrons and electrons and between charged particles and gamma rays. The instrument will be launched to the ISS within 2014 Japanese Fiscal Year (by the end of March 2015) and installed on the Japanese Experiment Module-Exposed Facility (JEM-EF). In this paper, we will review the status and main science goals of the mission and describe the instrument configuration and performance.

  15. The Calorimetric Electron Telescope (CALET) for High Energy Astroparticle Physics on the International Space Station

    NASA Astrophysics Data System (ADS)

    Torii, Shoji

    The Calorimetric Electron Telescope, CALET, space experiment, currently under development by Japan in collaboration with Italy and the United States, will measure the flux of Cosmic Ray electrons (and positrons) t o 20 TeV, gamma rays to 10 TeV , nuclei with Z=1 to 40 up to 1,000 TeV, and Gamma-ray bursts in the 7 keV- 10 MeV energy range during a five year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of Calet, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fiber planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch, during the Japan Fiscal Year (April, 2014- March, 2015) time frame, to the International Space Station (ISS) for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF).

  16. A combined calorimetric and computational study of the energetics of rare earth substituted UO 2 systems

    SciTech Connect

    Zhang, Lei; Solomon, Jonathan M.; Asta, Mark; Navrotsky, Alexandra

    2015-09-01

    The energetics of rare earth substituted UO2 solid solutions (U1-xLnxO2-0.5x+y, where Ln = La, Y, and Nd) are investigated employing a combination of calorimetric measurements and density functional theory based computations. Calculated and measured formation enthalpies agree within 10 kJ/mol for stoichiometric oxygen/metal compositions. To better understand the factors governing the stability and defect binding in rare earth substituted urania solid solutions, systematic trends in the energetics are investigated based on the present results and previous computational and experimental thermochemical studies of rare earth substituted fluorite oxides (A1-xLnxO2-0.5x, where A = Hf, Zr, Ce, and Th). A consistent trend towards increased energetic stability with larger size mismatch between the smaller host tetravalent cation and the larger rare earth trivalent cation is found for both actinide and non-actinide fluorite oxide systems where aliovalent substitution of Ln cations is compensated by oxygen vacancies. However, the large exothermic oxidation enthalpy in the UO2 based systems favors oxygen rich compositions where charge compensation occurs through the formation of uranium cations with higher oxidation states.

  17. Calorimetric measurement of heat load in full non-inductive LHCD plasmas on TRIAM-1M

    NASA Astrophysics Data System (ADS)

    Hanada, K.; Shinoda, N.; Sugata, T.; Sasaki, K.; Zushi, H.; Nakamura, K.; Sato, K. N.; Sakamoto, M.; Idei, H.; Hasegawa, M.; Kawasaki, S.; Nakashima, H.; Higashijima, A.; Triam Group

    2007-06-01

    Calorimetric measurements using the temperature increment of cooling-water were carried out to estimate the heat load distribution on the plasma facing components (PFCs) in the limiter discharges on TRIAM-1M. Line averaged electron density, ne, and LH power, PLH, dependences of the heat load on PFCs were measured. The heat load on the limiters was proportional to ne1.5 in the range of ne = 0.2-1.0 × 1019 m-3 and PLH1 in the range of PLH = 0.005-0.09 MW. For PLH > 0.1 MW, the plasma transition to an enhanced current drive (ECD) mode appeared and the ne dependences on the heat load on the limiter moderated. This indicates that the heat flux to scrape-off layer (SOL) region was reduced due to the improvement of the plasma confinement. The up-down asymmetry of the heat load on the vacuum vessel was enhanced in the ECD mode, which may be caused by the increasing of the direct loss of energetic electrons.

  18. Calorimetric measurement of electron energy deposition in extended media. Theory vs experiment

    SciTech Connect

    Lockwood, G.J.; Ruggles, L.E.; Miller, G.H.; Halbleib, J.A.

    1980-01-01

    A new calorimetric technique has been developed for measuring electron energy deposition profiles in one dimension. The experimental procedures and theoretical analyses required in the application of the new method are reviewed. Extensive results are presented for electron energy deposition profiles in semi-infinite homogeneous and multilayer configurations. These data cover a range of elements from beryllium through uranium at source energies from 0.3 to 1.0 MeV (selected data at 0.5 and 0.1 MeV) and at incident angles from 0/sup 0/ to 60/sup 0/. In every case, the experimental profiles are compared with the predictions of a coupled electron/photon Monte Carlo transport code. Overall agreement between theory and experiment is very good. However, there appears to be a tendency for the theoretical profiles to be higher near the peaks and lower near the tails, especially in high-Z materials. There is also a discrepancy between theory and experiment in low-Z materials near high-Z/low-Z interfaces.

  19. First calorimetric determination of heat of extraction of 248Cm in a bi-phasic system

    SciTech Connect

    Leigh R. Martin; Peter R. Zalupski

    2011-06-01

    This report presents a summary of the work performed to meet FCR&D level 2 milestone M21SW050201, 'Complete the first calorimetric determination of heat of extraction of 248Cm in a bi-phasic system'. This work was carried out under the auspices of the Thermodynamics and Kinetics FCR&D work package. To complement previous work undertaken under this work package we have extended out heat of extraction studies by di-2-ethyl-hexyl-phosphoric acid to curium. This report also details the heat of extraction of samarium in the same system. This work was performed to not only test the methodology but also to check for consistency with the heats of extraction obtained with those in the prior literature. The heat of extraction for samarium that was obtained in this study was -9.6 kJ mol-1, which is in reasonable agreement with the previously obtained value of -10.9 kJ mol-1. The curium heat of extraction was performed under two sets of conditions and the obtained heats of extraction were in reasonable agreement with each other at -16.0 {+-} 1.1 and -16.8 {+-} 1.5 kJ mol-1.

  20. Calorimetric Analysis to Infer Primary Circuit Flow in Integral and Pool-Type Reactors

    NASA Astrophysics Data System (ADS)

    Coble, Jamie; Tarver, Ryan; Hines, J. Wesley

    2017-02-01

    Primary system flow rate is a key parameter for monitoring and controlling thermal power in a nuclear power plant. The existing fleet of large light water reactors uses direct measurements of primary flow rate with the application of venturi meters, orifice plates, and magnetic flowmeters in primary loop piping. Integral light water reactors and pool-type advanced reactor designs, however, have largely eliminated primary loop piping to improve the inherent safety characteristics of these reactors. Furthermore, longer operating cycles between maintenance opportunities (typically 4 to 40 years) limit the applicability of these direct measurement methods over the operating period. Methods to infer the primary flow rate based on other, easily measured parameters are needed to ensure the operability of integral and pool-type reactors. Calorimetric analysis across the intermediate heat exchanger was investigated for real-time inference of primary flow rate. Heat balance equations were applied to an experimental forced flow loop to evaluate the efficacy of this approach. When appropriate time delays and heat losses are accounted for, the primary flow rate was inferred with accuracy and 95% prediction variance of 1.57 and 4.80 % mean value, respectively.

  1. The CALorimetric Electron Telescope (CALET) for high-energy astroparticle physics on the International Space Station

    NASA Astrophysics Data System (ADS)

    Adriani, O.; Akaike, Y.; Asano, K.; Asaoka, Y.; Bagliesi, M. G.; Bigongiari, G.; Binns, W. R.; Bonechi, S.; Bongi, M.; Buckley, J. H.; Castellini, G.; Cherry, M. L.; Collazuol, G.; Ebisawa, K.; Di Felice, V.; Fuke, H.; Guzik, T. G.; Hams, T.; Hareyama, M.; Hasebe, N.; Hibino, K.; Ichimura, M.; Ioka, K.; Israel, M. H.; Javaid, A.; Kamioka, E.; Kasahara, K.; Kataoka, J.; Kataoka, R.; Katayose, Y.; Kawanaka, N.; Kitamura, H.; Kotani, T.; Krawczynski, H. S.; Krizmanic, J. F.; Kubota, A.; Kuramata, S.; Lomtadze, T.; Maestro, P.; Marcelli, L.; Marrocchesi, P. S.; Mitchell, J. W.; Miyake, S.; Mizutani, K.; Moiseev, A. A.; Mori, K.; Mori, M.; Mori, N.; Motz, H. M.; Munakata, K.; Murakami, H.; Nakagawa, Y. E.; Nakahira, S.; Nishimura, J.; Okuno, S.; Ormes, J. F.; Ozawa, S.; Palma, F.; Papini, P.; Rauch, B. F.; Ricciarini, S. B.; Sakamoto, T.; Sasaki, M.; Shibata, M.; Shimizu, Y.; Shiomi, A.; Sparvoli, R.; Spillantini, P.; Takahashi, I.; Takayanagi, M.; Takita, M.; Tamura, T.; Tateyama, N.; Terasawa, T.; Tomida, H.; Torii, S.; Tunesada, Y.; Uchihori, Y.; Ueno, S.; Vannuccini, E.; Wefel, J. P.; Yamaoka, K.; Yanagita, S.; Yoshida, A.; Yoshida, K.; Yuda, T.

    2015-08-01

    The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF).

  2. The CALorimetric Electron Telescope (CALET) for high-energy astroparticle physics on the International Space Station

    NASA Astrophysics Data System (ADS)

    Adriani, O.; Akaike, Y.; Asano, K.; Asaoka, Y.; Bagliesi, M. G.; Bigongiari, G.; Binns, W. R.; Bonechi, S.; Bongi, M.; Buckley, J. H.; Castellini, G.; Cherry, M. L.; Collazuol, G.; Ebisawa, K.; Di Felice, V.; Fuke, H.; Guzik, T. G.; Hams, T.; Hareyama, M.; Hasebe, N.; Hibino, K.; Ichimura, M.; Ioka, K.; Israel, M. H.; Javaid, A.; Kamioka, E.; Kasahara, K.; Kataoka, J.; Kataoka, R.; Katayose, Y.; Kawanaka, N.; Kitamura, H.; Kotani, T.; Krawczynski, H. S.; Krizmanic, J. F.; Kubota, A.; Kuramata, S.; Lomtadze, T.; Maestro, P.; Marcelli, L.; Marrocchesi, P. S.; Mitchell, J. W.; Miyake, S.; Mizutani, K.; Moiseev, A. A.; Mori, K.; Mori, M.; Mori, N.; Motz, H. M.; Munakata, K.; Murakami, H.; Nakagawa, Y. E.; Nakahira, S.; Nishimura, J.; Okuno, S.; Ormes, J. F.; Ozawa, S.; Palma, F.; Papini, P.; Rauch, B. F.; Ricciarini, S. B.; Sakamoto, T.; Sasaki, M.; Shibata, M.; Shimizu, Y.; Shiomi, A.; Sparvoli, R.; Spillantini, P.; Takahashi, I.; Takayanagi, M.; Takita, M.; Tamura, T.; Tateyama, N.; Terasawa, T.; Tomida, H.; Torii, S.; Tunesada, Y.; Uchihori, Y.; Ueno, S.; Vannuccini, E.; Wefel, J. P.; Yamaoka, K.; Yanagita, S.; Yoshida, A.; Yoshida, K.; Yuda, T.

    2015-05-01

    The CALorimetric Electron Telescope (CALET) is a space experiment, currently under development by Japan in collaboration with Italy and the United States, which will measure the flux of cosmic-ray electrons (and positrons) up to 20 TeV energy, of gamma rays up to 10 TeV, of nuclei with Z from 1 to 40 up to 1 PeV energy, and will detect gamma-ray bursts in the 7 keV to 20 MeV energy range during a 5 year mission. These measurements are essential to investigate possible nearby astrophysical sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. The main detector of CALET, the Calorimeter, consists of a module to identify the particle charge, followed by a thin imaging calorimeter (3 radiation lengths) with tungsten plates interleaving scintillating fibre planes, and a thick energy measuring calorimeter (27 radiation lengths) composed of lead tungstate logs. The Calorimeter has the depth, imaging capabilities and energy resolution necessary for excellent separation between hadrons, electrons and gamma rays. The instrument is currently being prepared for launch (expected in 2015) to the International Space Station ISS, for installation on the Japanese Experiment Module - Exposure Facility (JEM-EF).

  3. Calorimetrically obtained information about the efficiency of ectoine synthesis from glucose in Halomonas elongata.

    PubMed

    Maskow, T; Babel, W

    2001-07-02

    Compatible solutes are becoming more and more attractive commercially. Thus, knowledge of the efficiency of synthesis of compatible solutes from different carbon substrates is very important. As the growth rate and rates of formation of compatible solutes correspond to the heat flux, calorimetric measurements are particularly suitable for providing this information. By growing microorganisms continuously in a calorimeter, and generating a feeding stream with gradually increasing salinity without changing any other growth conditions, we were able to determine the efficiency of growth-associated synthesis of compatible solutes. This was shown for Halomonas elongata DMSZ 2581(T) growing on glucose, which synthesizes (at 25 degrees C) 1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) as its main osmotic counterweight. The requirement of biologically usable energy for its growth-associated synthesis was found to be very low: a 100% efficiency of the conversion of the substrate-carbon into ectoine is both theoretically possible and was reached approximately in practice. The growth rate and yield coefficient were essentially independent of the ectoine formation rate, and the rate of substrate-carbon assimilation was far greater than the rate of dissimilation. The specific maximum growth rate was limited by the rate of formation of ectoine.

  4. Calorimetric studies of the ammonia-water system with application to the outer solar system

    NASA Astrophysics Data System (ADS)

    Yarger, J.; Lunine, J. I.; Burke, M.

    1993-07-01

    A series of heating experiments was performed on the condensed ammonia-water system using a differential scanning calorimeter (DSC). The water-rich samples were cooled quickly to below 130 K, then heated at a variety of rates. Rather than a single peritectic melt at 176 K, expected for the equilibrium system of water ice and ammonia dihydrate, four enthalpic transitions were repeatedly seen in the temperature range 150-176 K. These transitions are generally consistent with the earlier calorimetric results of Van Kasteren (1973), who interpreted the lowest temperature exotherm as crystallization of an amorphous ammonia-water compound formed during cooling. We propose that both sets of experiments are seeing the crystallization of ammonia monohydrate, which is metastable relative to the dihydrate, followed by partial remelting and crystallization of dihydrate upon further heating. The apparent stability of the monohydrate in the dihydrate equilibrium field implies a potentially complex behavior of ammonia-water ices in satellites. Possible self-heating of the mixture by several tens of degrees up to the 170 K eutectic could make mobilization of ammonia-water liquids in icy satellite interiors energetically easier than previously thought.

  5. Le pompage optique naturel dans le milieu astrophysique

    NASA Astrophysics Data System (ADS)

    Pecker, J.-C.

    The title of this lecture abstracts only a part of it : the importance in astrophysics of the study of non-LTE situations has become considerable, as well in the stellar atmospheres as, still more, in the study of fortuitous coincidences as a mechanism of formation of emission line nebular spectra, or of molecular interstellar « masers ». Another part of this talk underlines the role of Kastler in his time, and describes his warm personality through his public reactions in front of the nuclear armement, of the Viet-Nam and Algerian wars, of the problems of political refugees... Kastler was a great scientist ; he was also a courageous humanist. 1976 : Les accords nucléaires du Brésil : allocution d'ouverture (19 mars). Colloque sur le sujet ci-dessus. 1976 : La promotion de la culture dans le nouvel ordre économique international, allocution à l'occasion d'une table ronde sur ce thème par l'UNESCO (23-27 juin 1976) ; « Sciences et Techniques », octobre 1976. 1979 : La bête immonde (avec J.-C. Pecker), « Le Matin », 20 mars. 1979 : Appel à nos ministres (avec J.-C. Pecker), « Le Monde », 13 décembre. 1979 : Le flou, le ténébreux, l'irrationnel (avec J.-C. Pecker), « Le Monde », 14 septembre. 1980 : Education à la paix, Préface, in : Publ. UNESCO. 1981 : Le vrai danger, « Le Monde », 6 août 1981. 1982 : Nucléaire civil et militaire, « Le Monde », 1er juin 1982. 1982 : Les scientifiques face à la perspective d'holocauste nucléaire (texte inédit). Le titre de cette communication en résume seulement une partie : l'importance prise en astrophysique par l'analyse des situations hors ETL est devenue considérable, qu'il s'agisse des atmosphères stellaires, ou plus encore, des coïncidences fortuites de la formation des spectres d'émission nébulaires, ou des « masers » moléculaires interstellaires. Une autre partie de cet exposé souligne lele de Kastler dans son époque, et décrit sa personnalité généreuse à travers ses r

  6. Prendre le virage des partenariats.

    PubMed

    Sebestyen, Norma; Sulatycky, Ron; Rondos, Spyro; Davis, Sheila

    2015-11-01

    Deux projets démontrent que la mise en œuvre de données colligées sur le terrain peut contribuer à régler des problèmes dans le milieu de la santé pour favoriser de meilleurs résultats et de plus grandes efficiences. Dans le premier exemple, une vaste coalition de partenaires publics et privés de l'Alberta recourt aux techniques de mesures améliorées et à la méthodologie du Triple objectif pour améliorer les résultats cliniques de populations de cas complexes et lourds du quartier Eastwood d'Edmonton. On espère que les conclusions novatrices qui en sont tirées seront adaptées à d'autres régions de la province. Dans le deuxième exemple, la Childhood Obesity Foundation s'associe à Merck au Canada et à Ayogo (une société de thérapies numériques située à Vancouver) et utilise le concept novateur de la « ludification » pour mobiliser les jeunes de plus en plus sédentaires du Canada et modifier leurs comportements. © 2015 Collège canadien des leaders en santé

  7. An IR and Calorimetric Investigation of the Structural, Crystal-Chemical and Thermodynamic Properties of Hydrogrossular

    NASA Astrophysics Data System (ADS)

    Geiger, C. A.; Dachs, E.

    2012-04-01

    their collective interactions measurably affect the lattice dynamic (i.e. thermodynamic) behavior. The low temperature heat capacity behavior was investigated with a commercially designed relaxation calorimeter between 5 and 300 K on a mg-sized sample. The heat capacity data are well behaved at T < 300 K and show a monotonic decrease in magnitude with decreasing temperature. A standard third-law entropy value of So = 421.7 ± 1.6 J/mol·K was calculated. Using this new calorimetric-based So value and published standard enthalpy of formation data for katoite, a calorimetric-based Gibbs free energy of formation at 298 K can be obtained as ΔG°f = -5021.2 kJ/mol. The Cp data show no evidence for any phase transition as possibly expected by the change in OH-mode behavior with decreasing temperature. We have no explanation for the appearance of the additional modes. It is worth noting that the katoite crystal structure in terms of lattice dynamic or thermodynamic behavior should be thought of having OH groups and not O4H4 clusters or polyhedral units as is often written in the literature. The single crystallographic OH group in katoite shows very weak, if any, hydrogen bonding and the H atoms have large amplitudes of vibration. The weak H bonding controls the nature of low energy OH-related vibrations and this leads to its large So value.

  8. Combined online spectroscopic, calorimetric, and chemometric analysis: reaction enthalpy determinations in single and parallel reactions.

    PubMed

    Tjahjono, Martin; Widjaja, Effendi; Garland, Marc

    2009-06-02

    Calorimetry and signal processing: Vibrational spectroscopies, heat-flow microcalorimetry, and multivariate analysis are combined to decouple the reaction enthalpies of parallel reactions [picture: see text]. This methodology allows the evaluation of reaction enthalpy from complex systems without recourse to conventional kinetic modeling. Simultaneous in situ/online spectroscopy and heat-flow measurements as well as multivariate analyses are performed, apparently for the first time, to determine heats of reaction for single and parallel reactions. Two different vibrational spectroscopy techniques, namely Raman and FTIR spectroscopy, are used in conjunction with flow-through TAM III microcalorimetry. With respect to the spectroscopic analysis, the reaction spectra are first analyzed to determine the pure-component spectra and the corresponding concentrations without recourse to external calibration. With respect to the calorimetric analysis, a soft modeling approach is employed to determine the heats of reaction without recourse to any conventional kinetic models. This combined approach is implemented to determine the extents of reaction as well as the corresponding heats of reaction at 298.15 K and 0.1 MPa for a) the hydrolysis of acetic anhydride (single reaction) and b) the hydrolysis of methyl paraben and ethyl paraben in alkaline solution (both single and parallel reactions). In the latter case, the heat-flow contributions from the two simultaneous reactions are successfully decoupled. Taken together, these results demonstrate proof of concept for the present approach. The newly developed methodology appears to be quite general and particularly useful for investigating complex reaction systems. This is particularly true for multiple simultaneous reactions and reactions where the detailed kinetic expressions are not available, or cannot be easily determined. The use of extents of reaction is also very helpful where there is high variability in reaction rates

  9. Thermodynamic model for calorimetric and phase coexistence properties of coal derived fluids. Final technical report

    SciTech Connect

    Kabadi, V.N.

    1992-10-01

    The work on this project was initiated on September 1, 1989. The project consisted of three different tasks. 1. A thermodynamic model to predict VLE and calorimetric properties of coal liquids. 2. VLE measurements at high temperature and high pressure for coal model compounds and 3. Chromatographic characterization of coal liquids for distribution of heteroatoms. The thermodynamic model developed is an extension of the previous model developed for VLE of coal derived fluids (DOE Grant no. FG22-86PC90541). The model uses the modified UNIFAC correlation for the liquid phase. Some unavailable UNIFAC interactions parameters have been regressed from experimental VLE and excess enthalpy data. The model is successful in predicting binary VLE and excess enthalpy data. Further refinements of the model are suggested. An apparatus for the high pressure high temperature VLE data measurements has been built and tested. Tetralin-Quinoline is the first binary system selected for data measurements. The equipment was tested by measuring 325{degree}C isotherm for this system and comparing it with literature data. Additional isotherms at 350{degree}C and 370{degree}C have been measured. The framework for a characterization procedure for coal derived liquids has been developed. A coal liquid is defined by a true molecular weight distribution and distribution of heteroatoms as a function of molecular weights. Size exclusions liquid chromatography, elemental analysis and FTIR spectroscopy methods are used to obtain the molecular weight and hetroatom distributions. Further work in this area should include refinements of the characterization procedure, high temperature high pressure VLE data measurements for selective model compound binary systems, and improvement of the thermodynamic model using the new measured data and consistent with the developments in the characterization procedure.

  10. Seasonal Variability in Calorimetric Energy Content of Two Caribbean Mesophotic Corals

    PubMed Central

    Brandtneris, Viktor W.; Brandt, Marilyn E.; Glynn, Peter W.; Gyory, Joanna; Smith, Tyler B.

    2016-01-01

    Energetic responses of zooxanthellate reef corals along depth gradients have relevance to the refugia potential of mesophotic coral ecosystems (MCEs). Previous observations suggested that MCEs in the Caribbean are thermally buffered during the warmest parts of the year and occur within or just below the chlorophyll maximum, suggesting abundant trophic resources. However, it is not known if mesophotic corals can maintain constant energy needs throughout the year with changing environmental and biological conditions. The energetic content of tissues from the stony coral species Orbicella faveolata and Agaricia lamarcki was measured on the southern insular shelf of St. Thomas, US Virgin Islands (USVI), using micro-bomb calorimetry. Three sites for each species, at depths of 6m, 25m, 38m and 63m, were selected to capture energetic differences across the major vertical range extent of both species in the USVI—and sampled over five periods from April 2013 to April 2014. Mesophotic colonies of O. faveolata exhibited a significant reduction in energetic content during the month of September 2013 compared to mid-depth and shallow colonies (p = 0.032), whereas A. lamarcki experienced similar energetic variability, but with a significant reduction in energy content that occurred in July 2013 for colonies at sites deeper than 25m (p = 0.014). The results of calorimetric analyses indicate that O. faveolata may be at risk during late summer stress events, possibly due to the timing of reproductive activities. The low-point of A. lamarcki energy content, which may also coincide with reproduction, occurs prior to seasonal stress events, indicating contrasting, species-specific responses to environmental variability on MCEs. PMID:27050430

  11. Calorimetric evidence for phase transitions in spin-label lipid bilayers.

    PubMed

    Chen, S C; Sturtevant, J M; Conklin, K; Gaffney, B J

    1982-09-28

    Dispersions of pure, spin-label phosphatidylcholines in aqueous buffer have been investigated with the Privalov high-sensitivity differential scanning calorimeter. The lipids studied are mixed-chain ones in which C-2 of glycerol bears a spin-label derivative of stearic acid and the fatty acid group at C-1 is palmitate. A well-defined phase transition is observed at 30.3-30.7 degrees C for the phosphatidylcholine labeled near the polar end of the stearate chain (label at C-5). A sharp transition (32-34 degrees C) is also observed for the lipid spin-labeled near the terminal methyl of stearate (label at C-16), but the thermodynamic parameters for this lipid depend strongly on the history of the sample. Calorimetric evidence for hysteresis in the phase transition of the C-16-labeled lipid is presented. In contrast to the above spin-label lipids, the lipid labeled at C-12 does not show a sharp transition in the region 5-35 degrees C. In general, therefore, the thermal behavior of the spin-label phosphatidylcholines resembles that of phosphatidylcholines bearing double bonds or branched methyl groups at similar locations on acyl chains. During synthesis of mixed-chain lipids, migration of acyl chains occurs. Methyl esterification procedures which are compatible with the acid-labile spin-label group are described. Gas chromatographic analysis of methyl esters shows that chain migration during synthesis gives 15-20% of the spin-label fatty acid at the glycerol C-1 position.

  12. Calorimetric studies of the kinetic unfreezing of molecular motions in hydrated lysozyme, hemoglobin, and myoglobin.

    PubMed Central

    Sartor, G; Mayer, E; Johari, G P

    1994-01-01

    Differential scanning calorimetric (DSC) studies of the glassy states of as-received and hydrated lysozyme, hemoglobin, and myoglobin powders, with water contents of < or = 0.25, < or = 0.30, and < or = 0.29 g/g of protein, show that their heat capacity slowly increases with increasing temperature, without showing an abrupt increase characteristic of glass-->liquid transition. Annealing (also referred to as physical aging) of the hydrated proteins causes their DSC scans to show an endothermic region, similar to an overshoot, immediately above the annealing temperature. This annealing effect appears at all temperatures between approximately 150 and 300 K. The area under these peaks increases with increasing annealing time at a fixed temperature. The effects are attributed to the presence of a large number of local structures in which macromolecular segments diffuse at different time scales over a broad range. The lowest time scale corresponds to the > N-H and -O-H group motions which become kinetically unfrozen at approximately 150-170 K on heating at a rate of 30 K min-1 and which have a relaxation time of 5-10 s in this temperature range. The annealing effects confirm that the individual glass transition of the relaxing local regions is spread over a temperature range up to the denaturation temperature region of the proteins. The interpretation is supported by simulation of DSC scans in which the distribution of relaxation times is assumed to be exceptionally broad and in which annealing done at several temperatures over a wide range produces endothermic effects (or regions of DSC scans) qualitatively similar to those observed for the hydrated proteins. PMID:8130342

  13. Competitive binding of anticancer drugs 5-fluorouracil and cyclophosphamide with serum albumin: Calorimetric insights.

    PubMed

    Thoppil, Anu A; Choudhary, Sinjan; Kishore, Nand

    2016-05-01

    Isothermal titration calorimetry (ITC) has emerged as an excellent method to characterize drug-protein interactions. 5-Fluorouracil and cyclophosphamide have been used in combination for the treatment of breast carcinoma, though individually these drugs have also been useful in treating other types of cancer. A quantitative understanding of binding of these drugs with the transport protein under different conditions is essential for optimizing recognition by the protein and delivery at the target. The values of binding constant, enthalpy, and entropy of binding have been determined by using ITC. Fluorescence and circular dichroism spectroscopies have been used to obtain further support to calorimetric observations, monitor conformational changes in the protein and establishing stoichiometry of association. The thermodynamic parameters have enabled a quantitative understanding of the affinity of 5-fluorouracil and cyclophosphamide with bovine serum albumin. The nature of binding has been unraveled based on effect of ionic strength, tetrabutyl-ammonium bromide, and sucrose which interfere in ionic, hydrophobic, and hydrogen bonding interactions. The binding site has been identified by using site marker warfarin in combination with 5-fluorouracil and cyclophosphamide. Further, the experiments have been done to establish whether both the drugs share the same binding site, and the effect of antibiotic drug carbenecillin and anti-inflammatory drug naproxen on their association. Tuning optimum association of drugs with the transport vehicles for effective drug delivery requires identification of the nature of interacting groups in terms of energetics of interactions. Such studies employing ITC have direct significance in rational drug design. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Energetics of carbohydrate binding to Momordica charantia (bitter gourd) lectin: an isothermal titration calorimetric study.

    PubMed

    Sultan, Nabil Ali Mohammed; Swamy, Musti J

    2005-05-01

    Physico-chemical and carbohydrate binding studies have been carried out on the Momordica charantia (bitter gourd) seed lectin (MCL). The lectin activity is maximal in the pH range 7.4-11.0, but decreases steeply below pH 7.0. The lectin activity is mostly unaffected in the temperature range 4-50 degrees C, but a sharp decrease is seen between 50 and 60 degrees C, which could be correlated to changes in the structure of the protein as seen by circular dichroism and fluorescence spectroscopy. Isothermal titration calorimetric studies show that the tetrameric MCL binds two sugar molecules and the binding constants (Kb), determined at 288.15 K, for various saccharides were found to vary between 7.3 x 10(3) and 1.52 x 10(4)M(-1). The binding reactions for all the saccharides investigated were essentially enthalpy driven, with the binding enthalpies (DeltaHb) at 288.15 K being in the range of -50.99 and -43.39 kJ mol(-1), whereas the contribution to the binding reaction from the entropy of binding was negative, with values of binding entropy (DeltaSb) ranging between -99.2 and -72.0 J mol(-1)K(-1) at 288.15 K. Changes in heat capacity (DeltaCp) for the binding of disaccharides, lactose and lactulose, were significantly larger in magnitude than those obtained for the monosaccharides, methyl-beta-D-galactopyranoside, and methyl-alpha-D-galactopyranoside, and could be correlated reasonably well with the surface areas of these ligands. Enthalpy-entropy compensation was observed for all the sugars studied, suggesting that water structure plays an important role in the overall binding reaction. CD spectroscopy indicates that carbohydrate binding does not lead to significant changes in the secondary and tertiary structures of MCL, suggesting that the carbohydrate binding sites on this lectin are mostly preformed.

  15. Calorimetric and spectroscopic studies on solvation energetics for H₂ storage in the CO₂/HCOOH system.

    PubMed

    Fink, Cornel; Katsyuba, Sergey; Laurenczy, Gabor

    2016-04-28

    Solvents playing a crucial role in many chemical reactions and additives can be used to shift the reaction equilibrium. Herein we study the enthalpy of mixing for selected solvents (aqueous, organic) and basic additives (amines, aqueous KOH) when mixed with formic acid with the aim to optimize hydrogen storage/delivery in the CO2/HCOOH system. Formic acid, resulting from carbon dioxide hydrogenation, reaches highest yields when effectively "removed" from the reaction equilibrium. In terms of energy efficiency, any heat released during CO2 hydrogenation has to be reused in the reverse reaction, during the production of hydrogen. In any scenario, the usage of basic chemicals, non-innocent solvents, causes higher energy release in CO2 hydrogenation, which has to be reused in the hydrogen delivery process. Therefore, the enthalpy of mixing is a valuable parameter for designing hydrogen storage devices since it allows the estimation of energy balance for the CO2 hydrogenation/H2 liberation cycle. The highest formic acid concentrations in direct catalytic CO2 hydrogenation under acidic conditions were reached in DMSO. DMSO exhibits considerably stronger interactions with formic acid compared to water as was observed in calorimetric measurements. This difference can be ascribed, at least partly, to stronger hydrogen bonding of FA to DMSO than to water in the corresponding solutions, examined by a combination of IR spectroscopic and quantum chemical studies. Furthermore, the investigation of DMSO/FA- and water/FA systems by (1)H- and (13)C-NMR spectroscopy revealed that only 1 : 1 aggregates are formed in the DMSO solutions of FA in a broad concentration range, while the stoichiometry and the number of the FA-water aggregates essentially depend on the concentration of aqueous solutions.

  16. Les hommes regardent le ciel.

    NASA Astrophysics Data System (ADS)

    Jaschek, C.

    Contents: 1. Le ciel nocturne. 2. Le mouvement du soleil. 3. La lune et ses mouvements. 4. L'orientation des bâtiments. 5. Les étoiles et les constellations. 6. Les planètes. 7. Les comètes, météores et météorites. 8. Les phénomènes météorologico-astronomiques. 9. Les éclipses. 10. Le temps et les calendriers. 11. Astres et destinée humaine - l'astrologie. 12. Les mythes de la création du monde. 13. Les mythes de la fin du monde. 14. Astronomie et société.

  17. Investigation of ferroelectric phase transitions of water in nanoporous silicates in simultaneous electrical noise and calorimetric measurements

    NASA Astrophysics Data System (ADS)

    Bordonskiy, G. S.; Orlov, A. O.

    2014-08-01

    The phase transitions of water in the nanoporous silicate materials SBA-15 and MCM-41 with an ordered system of cylindrical pores have been investigated. Measurements of low-frequency electrical noises (Barkhausen noises) in the frequency range of 1-100 Hz have been performed simultaneously with relative calorimetric measurements. It has been found that the voltage of electrical fluctuations increases approximately 100 times in the temperature range from -30 to -50°C, which is associated with the first-order and second-order ferroelectric phase transitions. It has been assumed that the ferroelectric ice XI can be formed in capillary pores of the materials under investigations.

  18. Calorimetric system for high-precision determination of activity of the 51Cr neutrino source in the BEST experiment

    NASA Astrophysics Data System (ADS)

    Veretenkin, E. P.; Gavrin, V. N.; Danshin, S. N.; Ibragimova, T. V.; Kalashnikova, A. A.; Kozlova, J. P.; Martynov, A. A.

    2017-01-01

    The calorimetric system based on mass-flow calorimeter for high-precision determination of neutrino flux from 51Cr source with activity 3MCi and higher is created for experiment BEST. The achieved heat release uncertainties are less than 0.25% in the whole range of the heat power and less than 0.1% in the range of 250-500 W. Total value the uncertainty considering the uncertainty of the energy release in the 51Cr decay (0.23%) shows that the activity of 3MCi 51Cr neutrino source can be determined with accuracy better than 0.5%.

  19. Calorimetric and spectroscopic studies of aminoglycoside binding to AT-rich DNA triple helices

    PubMed Central

    Xi, Hongjuan; Kumar, Sunil; Dosen-Micovic, Ljiljana; Arya, Dev P.

    2013-01-01

    Calorimetric and fluorescence techniques were used to characterize the binding of aminoglycosides-neomycin, paromomycin, and ribostamycin, with 5′-dA12-x-dT12-x-dT12-3′ intramolecular DNA triplex (x = hexaethylene glycol) and poly(dA).2poly(dT) triplex. Our results demonstrate the following features: (1) UV thermal analysis reveals that the Tm for triplex decreases with increasing pH value in the presence of neomycin, while the Tm for the duplex remains unchanged. (2) The binding affinity of neomycin decreases with increased pH, although there is an increase in observed binding enthalpy. (3) ITC studies conducted in two buffers (sodium cacodylate and MOPS) yield the number of protonated drug amino groups (Δn) as 0.29 and 0.40 for neomycin and paromomycin interaction with 5′-dA12-x-dT12-x-dT12-3′, respectively. (4) The specific heat capacity change (ΔCp) determined by ITC studies is negative, with more negative values at lower salt concentrations. From 100 mM to 250 mM KCl, the ΔCp ranges from −402 to −60 cal/(mol K) for neomycin. At pH 5.5, a more positive ΔCp is observed, with a value of −98 cal/(mol K) at 100 mM KCl. ΔCp is not significantly affected by ionic strength. (5) Salt dependence studies reveal that there are at least three amino groups of neomycin participating in the electrostatic interactions with the triplex. (6) FID studies using thiazole orange were used to derive the AC50 (aminoglycoside concentration needed to displace 50% of the dye from the triplex) values. Neomycin shows a seven fold higher affinity than paromomycin and eleven fold higher affinity than ribostamycin at pH 6.8. (7) Modeling studies, consistent with UV and ITC results, show the importance of an additional positive charge in triplex recognition by neomycin. The modeling and thermodynamic studies indicate that neomycin binding to the DNA triplex depends upon significant contributions from charge as well as shape complementarity of the drug to the DNA triplex

  20. Le verifiche della relatività generale

    NASA Astrophysics Data System (ADS)

    Tempesti, Piero

    2005-10-01

    La relatività di Einstein. La relatività generale messa alla prova. Le tre verifiche classiche: L'avanzamento del perielio di Mercurio - La deflessione della luce - Il redshift gravitazionale. Le verifiche di seconda generazione: Il rallentamento della luce - L'effetto Nordtvedt - Le onde gravitazionali e la "pulsar binaria".

  1. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2002-12-01

    XMM à la recherche de la matière exotique; Ancienne étoile; Le Trou noir volant; Magnétar; Stardust et Annefrank; Le centre de la galaxie; Deux trous noirs dans la même galaxie; Eruption géante sur Io; Le Soleil;

  2. Le LHC, un tunnel cosmique

    ScienceCinema

    None

    2016-07-12

    Et si la lumière au bout du tunnel du LHC était cosmique ? En d’autres termes, qu’est-ce que le LHC peut nous apporter dans la connaissance de l’Univers ? Car la montée en énergie des accélérateurs de particules nous permet de mieux appréhender l’univers primordial, chaud et dense. Mais dans quel sens dit-on que le LHC reproduit des conditions proches du Big bang ? Quelles informations nous apporte-t-il sur le contenu de l’Univers ? La matière noire est-elle détectable au LHC ? L’énergie noire ? Pourquoi l’antimatière accumulée au CERN est-elle si rare dans l’Univers ? Et si le CERN a bâti sa réputation sur l’exploration des forces faibles et fortes qui opèrent au sein des atomes et de leurs noyaux, est-ce que le LHC peut nous apporter des informations sur la force gravitationnelle qui gouverne l’évolution cosmique ? Depuis une trentaine d’années, notre compréhension de l’univers dans ses plus grandes dimensions et l’appréhension de son comportement aux plus petites distances sont intimement liées : en quoi le LHC va-t-il tester expérimentalement cette vision unifiée ? Tout public, entrée libre / Réservations au +41 (0)22 767 76 76

  3. Calorimetric determination of the enthalpy of 1-butyl-3-methylimidazolium bromide synthesis: a key quantity in thermodynamics of ionic liquids.

    PubMed

    Paulechka, Yauheni U; Kabo, Andrey G; Blokhin, Andrey V

    2009-11-05

    The enthalpy of the 1-butyl-3-methylimidazolium bromide [C(4)mim]Br ionic liquid synthesis reaction 1-methylimidazole (liq) + 1-bromobutane (liq) --> [C(4)mim]Br (liq) was determined in a homemade small-volume isoperibol calorimeter to be Delta(r)H degrees (298) = -87.7 +/- 1.6 kJ x mol(-1). The activation energy for this reaction in a homogeneous system E(A) = 73 +/- 4 kJ x mol(-1) was found from the results of calorimetric measurements. The formation enthalpies for the crystalline and liquid [C(4)mim]Br were determined from the calorimetric data: Delta(f)H degrees (298)(cr) = -178 +/- 5 kJ x mol(-1) and Delta(f)H degrees (298)(liq) = -158 +/- 5 kJ x mol(-1). The ideal-gas formation enthalpy of this compound Delta(f)H degrees (298)(g) = 16 +/- 7 kJ x mol(-1) was calculated using the methods of quantum chemistry and statistical thermodynamics. The vaporization enthalpy of [C(4)mim]Br, Delta(vap)H degrees (298) = 174 +/- 9 kJ x mol(-1), was estimated from the experimental and calculated formation enthalpies. It was demonstrated that vapor pressure of this ionic liquid cannot be experimentally determined.

  4. Development of Metallic Magnetic Calorimeters for High Precision Measurements of Calorimetric Re-187 and Ho-163 Spectra

    NASA Technical Reports Server (NTRS)

    Ranitzsch, P. C.-O.; Porst, J.-P.; Kempf, S.; Pies, C.; Schafer, S.; Hengstler, D.; Fleischmann, A.; Enss, C.; Gastaldo, L.

    2012-01-01

    The measurement of calorimetric spectra following atomic weak decays, beta (b) and electron capture (EC), of nuclides having a very low Q-value, can provide an impressively high sensitivity to a non-vanishing neutrino mass. The achievable sensitivity in this kind of experiments is directly connected to the performance of the used detectors. In particular an energy resolution of a few eV and a pulse formation time well below 1 microsecond are required. Low temperature Metallic Magnetic Calorimeters (MMCs) for soft X-rays have already shown an energy resolution of 2.0 eV FWHM and a pulse rise-time of about 90 ns for fully micro-fabricated detectors. We present the use of MMCs for high precision measurements of calorimetric spectra following the beta-decay of Re-187 and the EC of Ho-163. We show results obtained with detectors optimized for Re-187 and for Ho-163 experiments respectively. While the detectors equipped with superconducting Re absorbers have not yet reached the aimed performance, a first detector prototype with a Au absorber having implanted Ho-163 ions already shows excellent results. An energy resolution of 12 eV FWHM and a rise time of 90 ns were measured.

  5. Disruption of Hydrogen-Bonding Network Eliminates Water Anomalies Normally Observed on Cooling to Its Calorimetric Glass Transition

    DOE PAGES

    Borreguero, Jose M.; Mamontov, Eugene

    2017-04-11

    Here, the calorimetric glass-transition temperature of water is 136 K, but extrapolation of thermodynamic and relaxation properties of water from ambient temperature to below its homogeneous nucleation temperature TH = 235 K predicts divergence at TS = 228 K. The “no-man’s land” between the TH and glassy water crystallization temperature of 150 K, which is encountered on warming up from the vitrified state, precludes a straightforward reconciliation of the two incompatible temperature dependences of water properties, above 235 K and below 150 K. The addition of lithium chloride to water allows bypassing both TH and TS on cooling, resulting inmore » the dynamics with no features except the calorimetric glass transition, still at 136 K. We show that lithium chloride prevents hydrogen-bonding network completion in water on cooling, as manifested, in particular, in changing microscopic diffusion mechanism of the water molecules. Thus thermodynamic and relaxation peculiarities exhibited by pure water on cooling to its glass transition, such as the existence of the TH and TS, must be associated specifically with the hydrogen-bonding network.« less

  6. Host-guest interaction of 3-hydroxyflavone and 7-hydroxyflavone with cucurbit [7]uril: A spectroscopic and calorimetric approach.

    PubMed

    Ahmed, Sayeed Ashique; Maity, Banibrata; Duley, Soma Seth; Seth, Debabrata

    2017-03-01

    The modulation of photophysical behaviour of small organic molecules in the presence of macrocycles is one of the most interesting areas of research. In this work we reported the interaction of two biologically active molecules 3-hydroxyflavone and 7-hydroxyflavone with macrocyclic host cucurbit [7]uril in aqueous medium. To investigate the change of photophysical properties of these two flavones, we have used steady state absorption, fluorescence, time resolved fluorescence emission spectroscopy and isothermal titration calorimetric technique. It is observed that on complexation with cucurbit [7]uril, the excited state proton transfer processes in both flavones have been facilitated. Isothermal titration calorimetric method was used in order to investigate the involvement of thermodynamic parameters in complexation between flavone with cucurbit [7]uril. The changes in thermodynamic properties due to the complexation of the flavones molecules with cucurbit [7]urils help to understand about the governing parameters involved in this complexation. The inclusion of flavone molecules inside the cavity of cucurbit [7]uril molecules was studied theoretically to decipher the molecular orientation of flavones in the presence of cucurbit [7]uril. The structure of HOMO and LUMO of the complexes between cucurbit [7]uril with flavones was reported. This study will be helpful to get the knowledge about the modulation of photophysical properties of the flavones molecules on addition of macrocyclic host cucurbit [7]uril. This study will be helpful for the use of cucurbit [7]uril as a potential drug delivery system.

  7. Development of Metallic Magnetic Calorimeters for High Precision Measurements of Calorimetric Re-187 and Ho-163 Spectra

    NASA Technical Reports Server (NTRS)

    Ranitzsch, P. C.-O.; Porst, J.-P.; Kempf, S.; Pies, C.; Schafer, S.; Hengstler, D.; Fleischmann, A.; Enss, C.; Gastaldo, L.

    2012-01-01

    The measurement of calorimetric spectra following atomic weak decays, beta (b) and electron capture (EC), of nuclides having a very low Q-value, can provide an impressively high sensitivity to a non-vanishing neutrino mass. The achievable sensitivity in this kind of experiments is directly connected to the performance of the used detectors. In particular an energy resolution of a few eV and a pulse formation time well below 1 microsecond are required. Low temperature Metallic Magnetic Calorimeters (MMCs) for soft X-rays have already shown an energy resolution of 2.0 eV FWHM and a pulse rise-time of about 90 ns for fully micro-fabricated detectors. We present the use of MMCs for high precision measurements of calorimetric spectra following the beta-decay of Re-187 and the EC of Ho-163. We show results obtained with detectors optimized for Re-187 and for Ho-163 experiments respectively. While the detectors equipped with superconducting Re absorbers have not yet reached the aimed performance, a first detector prototype with a Au absorber having implanted Ho-163 ions already shows excellent results. An energy resolution of 12 eV FWHM and a rise time of 90 ns were measured.

  8. Thermogravimetric and calorimetric characteristics during co-pyrolysis of municipal solid waste components.

    PubMed

    Ansah, Emmanuel; Wang, Lijun; Shahbazi, Abolghasem

    2016-10-01

    The thermogravimetric and calorimetric characteristics during pyrolysis of wood, paper, textile and polyethylene terephthalate (PET) plastic in municipal solid wastes (MSW), and co-pyrolysis of biomass-derived and plastic components with and without torrefaction were investigated. The active pyrolysis of the PET plastic occurred at a much higher temperature range between 360°C and 480°C than 220-380°C for the biomass derived components. The plastic pyrolyzed at a heating rate of 10°C/min had the highest maximum weight loss rate of 18.5wt%/min occurred at 420°C, followed by 10.8wt%/min at 340°C for both paper and textile, and 9.9wt%/min at 360°C for wood. At the end of the active pyrolysis stage, the final mass of paper, wood, textile and PET was 28.77%, 26.78%, 21.62% and 18.31%, respectively. During pyrolysis of individual MSW components at 500°C, the wood required the least amount of heat at 665.2J/g, compared to 2483.2J/g for textile, 2059.4J/g for paper and 2256.1J/g for PET plastic. The PET plastic had much higher activation energy of 181.86kJ/mol, compared to 41.47kJ/mol for wood, 50.01kJ/mol for paper and 36.65kJ/mol for textile during pyrolysis at a heating rate of 10°C/min. H2O and H2 peaks were observed on the MS curves for the pyrolysis of three biomass-derived materials but there was no obvious H2O and H2 peaks on the MS curves of PET plastic. There was a significant interaction between biomass and PET plastic during co-pyrolysis if the biomass fraction was dominant. The amount of heat required for the co-pyrolysis of the biomass and plastic mixture increased with the increase of plastic mass fraction in the mixture. Torrefaction at a proper temperature and time could improve the grindability of PET plastic. The increase of torrefaction temperature and time did not affect the temperature where the maximum pyrolytic rates occurred for both biomass and plastic but decreased the maximum pyrolysis rate of biomass and increased the maximum pyrolysis

  9. Microscopic and calorimetric assessment of freezing processes in uterine fibroid tumor tissue.

    PubMed

    Devireddy, R V; Coad, J E; Bischof, J C

    2001-06-01

    The use of cryosurgery in the treatment of uterine fibroids is emerging as a possible treatment modality. The two known mechanisms of direct cell injury during the tissue freezing process are linked to intracellular ice formation and cellular dehydration. These processes have not been quantified within uterine fibroid tumor tissue. This study reports the use of a combination of freeze-substitution microscopy and differential scanning calorimetry (DSC) to quantify freeze-induced dehydration within uterine fibroid tumor tissue. Stereological analysis of histological tumor sections was used to obtain the initial cellular volume (V(o)) or the Krogh model dimensions (deltaX, the distance between the microvascular channels = 15.5 microm, r(vo), the initial radius of the extracellular space = 4.8 micro m, and L, the axial length of the Krogh cylinder = 19.1 microm), the interstitial volume ( approximately 23%), and the vascular volume ( approximately 7%) of the fibroid tumor tissue. A Boyle-van't Hoff plot was then constructed by examining freeze-substituted micrographs of "equilibrium"-cooled tissue slices to obtain the osmotically inactive cell volume, V(b) = 0.47V(o). The high interstitial volume precludes the use of freeze-substitution microscopy data to quantify freeze-induced dehydration. Therefore, a DSC technique, which does not suffer from this artifact, was used to obtain the water transport data. A model of water transport was fit to the calorimetric data at 5 and 20 degrees C/min to obtain the "combined best fit" membrane permeability parameters of the embedded fibroid tumor cells, assuming either a Krogh cylinder geometry, L(pg) = 0.92 x 10(-13) m(3)/Ns (0.55 microm/min atm) and E(Lp) = 129.3 kJ/mol (30.9 kcal/mol), or a spherical cell geometry (cell diameter = 18.3 microm), L(pg) = 0.45 x 10(-13) m(3)/Ns (0.27 microm/min atm) and E(Lp) = 110.5 kJ/mol (26.4 kcal/mol). In addition, numerical simulations were performed to generate conservative estimates, in the

  10. Spectroscopic and calorimetric studies on the interaction between PAMAM G4-OH and 5-fluorouracil in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Buczkowski, Adam; Urbaniak, Pawel; Piekarski, Henryk; Palecz, Bartlomiej

    2017-01-01

    The results of spectroscopic measurements (an increase in solubility, equilibrium dialysis, 1H NMR titration) and calorimetric measurements (isothermal titration ITC) indicate spontaneous (ΔG < 0) binding of 5-fluorouracil molecules by PAMAM G4-OH dendrimer with terminal hydroxyl groups in an aqueous solution. PAMAM G4-OH dendrimer bonds about n = 8 ± 1 molecules of the drug with an equilibrium constant of K = 70 ± 10. The process of saturating the dendrimer active sites by the drug molecules is exothermal (ΔH < 0) and is accompanied by an advantageous change in entropy (ΔS > 0). The parameters of binding 5-fluorouracil by PAMAM G4-OH dendrimer were compared with those of binding this drug by the macromolecules of PAMAM G3-OH and G5-OH.

  11. SEM observations and differential scanning calorimetric studies of new and sterilized nickel-titanium rotary endodontic instruments.

    PubMed

    Alexandrou, Georgia B; Chrissafis, Konstantinos; Vasiliadis, Leonidas P; Pavlidou, Eleni; Polychroniadis, E K

    2006-07-01

    Scanning electron microscopy (SEM) and differential scanning calorimetric (DSC) studies were utilized to investigate surface and microstructure of two brands of rotary nickel-titanium (NiTi) endodontic instruments, in the as-received condition and after subjection to 1, 6, and 11 sterilization cycles. A total of 66 ProFile (n = 33) and Flexmaster (n = 33) files were examined. SEM observations indicated the presence of surface imperfections and adherent material in all new and sterilized instruments and an increase in surface roughness of the instruments that underwent multiple sterilizations. DSC measurements showed that the specimens of both brands, in the as-received condition and after 11 sterilizations, were completely austenite in the oral environment temperature, suggesting that they are capable of superelastic behavior in appropriate clinical conditions.

  12. Calorimetric analysis of the two way memory effect in a NiTi alloy -- Experiments and calculations

    SciTech Connect

    Silva, E.P. da

    1999-04-23

    In addition to the well known one-way memory effect in heating, some shape memory alloys may also exhibit a shape recovery upon cooling, i.e. they show the two-way memory effect (TWME). This is not an inherent property of such alloys, and to obtain it, the alloy must be trained. Besides the two-way memory effect, the training processes can also cause changes such as a shift of the transformation temperatures. In this work a calorimetric investigation of a one-way and two-way NiTi memory alloy is presented. The heat flow was measured by use of a Differential Scanning Calorimeter. The differences in the temperatures and enthalpy of transformations between one-way and two-way memory samples are presented, compared and discussed. A mathematical prediction of the heat and temperatures of transformation is presented.

  13. A structural and calorimetric study of the transformations in sputtered Al-Mn and Al-Mn-Si films

    SciTech Connect

    Chen, L.C.; Spaepen, F. ); Robertson, J.L.; Moss, S.C. ); Hiraga, K. )

    1990-09-01

    Scanning and isothermal calorimetry, together with x-ray diffraction and high resolution transmission electron microscopy (TEM), have been used to characterize Al-Mn and Al-Mn-Si films sputtered onto substrates at 60 {degree}C, 45 {degree}C, and {minus}100 {degree}C. In the case of Al{sub 0.83}Mn{sub 0.17}, the monotonically decreasing isothermal calorimetric signal, characteristic of a grain growth process, has proved decisive in identifying the as-sputtered amorphous'' state as microquasicrystalline, with an average grain size of {similar to}20 A in agreement with an estimate of correlation range from the x-ray pattern. The TEM at 400 keV reveals well-defined atomic or lattice images in annealed films but only barely resolved grains (ordered clusters) in the as-sputtered films. The relation between the metallic glass and the microquasicrystalline state in these alloys is discussed.

  14. Thermodynamic study of rhodamine 123-calf thymus DNA interaction: determination of calorimetric enthalpy by optical melting study.

    PubMed

    Masum, Abdulla Al; Chakraborty, Maharudra; Pandya, Prateek; Halder, Umesh Chandra; Islam, Md Maidul; Mukhopadhyay, Subrata

    2014-11-20

    In this paper, the interaction of rhodamine123 (R123) with calf thymus DNA has been studied using molecular modeling and other biophysical methods like UV-vis spectroscopy, fluoremetry, optical melting, isothermal titration calorimetry, and circular dichroic studies. Results showed that the binding energy is about -6 to -8 kcal/mol, and the binding process is favored by both negative enthalpy change and positive entropy change. A new method to determine different thermodynamic properties like calorimetric enthalpy and heat capacity change has been introduced in this paper. The obtained data has been crossed-checked by other methods. After dissecting the free-energy contribution, it was observed that the binding was favored by both negative hydrophobic free energy and negative molecular free energy which compensated for the positive free energies due to the conformational change loss of rotational and transitional freedom of the DNA helix.

  15. A micromachined calorimetric gas sensor: an application of electrodeposited nanostructured palladium for the detection of combustible gases.

    PubMed

    Bartlett, Philip N; Guerin, Samuel

    2003-01-01

    Palladium films with regular nanoarchitectures were electrochemically deposited from the hexagonal (H1) lyotropic liquid crystalline phase of the nonionic surfactant octaethyleneglycol monohexadecyl ether (C16EO8) onto micromachined silicon hotplate structures. The H1-e Pd films were shown to have high surface areas (approximately 28 m2 g(-1)) and to act as effective and stable catalysts for the detection of methane in air on heating to 500 degrees C. The response of the H1-e Pd-coated planar pellistors was found to be linearly proportional to the concentration of methane between 0 and 2.5% in air with a detection limit below 0.125%. Our results show that the electrochemical deposition of nanostructured metal films offers a promising approach to the fabrication of micromachined calorimetric gas sensors for combustible gases.

  16. Adsorption of methylene blue on raw and MTZ/imogolite hybrid surfaces: effect of concentration and calorimetric investigation.

    PubMed

    Guerra, Denis L; Batista, Adriano C; Viana, Rúbia R; Airoldi, Claudio

    2010-11-15

    The synthetic imogolite sample was used for organofunctionalization process with 2-mercaptothiazoline (MTZ). The compound 2-mercaptothiazoline was anchored onto imogolite surface by heterogeneous route. Due to the increment of basic centers attached to the pendant chains the dye adsorption capability of the final chelating material, was found to be higher than is precursor. The ability of these materials to remove methylene blue from aqueous solution was followed by a series of adsorption isotherms at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 40.32×10(-2) and 65.13×10(-2) mmol g(-1) for IMO and IMO(MTZ), respectively. The energetic effects caused by dye cations adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such methylene blue-nitrogen and sulfur interactions.

  17. Molecular Determinants of Antibiotic Recognition and Resistance by Aminoglycoside Phosphotransferase (3′)-IIIa: A Calorimetric and Mutational Analysis

    PubMed Central

    Kaul, Malvika; Barbieri, Christopher M.; Srinivasan, Annankoil R.; Pilch, Daniel S.

    2007-01-01

    Summary The growing threat from the emergence of multidrug resistant pathogens highlight a critical need to expand our currently available arsenal of broad-spectrum antibiotics. In this connection, new antibiotics must be developed that exhibit the abilities to circumvent known resistance pathways. An important step toward achieving this goal is to define the key molecular interactions that govern antibiotic resistance. Here, we use site-specific mutagenesis, coupled with calorimetric, NMR, and enzymological techniques, to define the key interactions that govern the binding of the aminoglycoside antibiotics neomycin and kanamycin B to APH(3′)-IIIa (an antibiotic phosphorylating enzyme that produces resistance). Our mutational analyses identify the D261, E262, and C-terminal F264 residues of the enzyme as being critical for recognition of the two drugs as well as the manifestation of the resistance phenotype. In addition, the E160 residue is more important for recognition of kanamycin B than neomycin, with mutation of this residue partially restoring sensitivity to kanamycin B but not to neomycin. By contrast, the D193 residue partially restores sensitivity to neomycin but not to kanamycin B, with the origins of this differential effect being due to the importance of D193 for catalyzing the phosphorylation of neomycin. These collective mutational results, coupled with 15N NMR-derived pKa and calorimetrically-derived binding-linked drug protonation data, identify the 1-, 3-, and 2′-amino groups of both neomycin and kanamycin B as being critical functionalities for binding to APH(3′)-IIIa. These drug amino functionalities represent potential sites of modification in the design of next-generation compounds that can overcome APH(3′)-IIIa-induced resistance. PMID:17418235

  18. Molecular determinants of antibiotic recognition and resistance by aminoglycoside phosphotransferase (3')-IIIa: a calorimetric and mutational analysis.

    PubMed

    Kaul, Malvika; Barbieri, Christopher M; Srinivasan, Annankoil R; Pilch, Daniel S

    2007-05-25

    The growing threat from the emergence of multidrug resistant pathogens highlights a critical need to expand our currently available arsenal of broad-spectrum antibiotics. In this connection, new antibiotics must be developed that exhibit the abilities to circumvent known resistance pathways. An important step toward achieving this goal is to define the key molecular interactions that govern antibiotic resistance. Here, we use site-specific mutagenesis, coupled with calorimetric, NMR, and enzymological techniques, to define the key interactions that govern the binding of the aminoglycoside antibiotics neomycin and kanamycin B to APH(3')-IIIa (an antibiotic phosphorylating enzyme that confers resistance). Our mutational analyses identify the D261, E262, and C-terminal F264 residues of the enzyme as being critical for recognition of the two drugs as well as for the manifestation of the resistance phenotype. In addition, the E160 residue is more important for recognition of kanamycin B than neomycin, with mutation of this residue partially restoring sensitivity to kanamycin B but not to neomycin. By contrast, the D193 residue partially restores sensitivity to neomycin but not to kanamycin B, with the origins of this differential effect being due to the importance of D193 for catalyzing the phosphorylation of neomycin. These collective mutational results, coupled with (15)N NMR-derived pK(a) and calorimetrically derived binding-linked drug protonation data, identify the 1-, 3-, and 2'-amino groups of both neomycin and kanamycin B as being critical functionalities for binding to APH(3')-IIIa. These drug amino functionalities represent potential sites of modification in the design of next-generation compounds that can overcome APH(3')-IIIa-induced resistance.

  19. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2008-09-01

    Fragmentation et astéroïdes binaires; Astéroïde géocroiseur triple; Rosetta sort de son hibernation; Messenger; Transit lunaire vu par Deep Impact; Titan; Phobos; Phoenix; Einstein avait raison; Le ballet des taches rouges; Le poids des lentilles;

  20. Le syndrome d'apert

    PubMed Central

    Benmiloud, Sarra; Chaouki, Sana; Atmani, Samir; Hida, Moustapha

    2013-01-01

    Le syndrome d'Apert est une affection congénitale rare, caractérisée par une sténose cranio-faciale associée à une syndactylie des mains et des pieds. Sa prise en charge doit être précoce et multidisciplinaire. Sa gravité réside dans la coexistence de plusieurs malformations avec un risque d'hypertension intracrânienne chronique responsable d'une cécité et d'une débilité mentale. Les auteurs rapportent une nouvelle observation à travers laquelle ils illustrent les aspects cliniques et évolutifs ainsi que les difficultés thérapeutiques de cette affection. PMID:23565313

  1. Intraday LeBaron effects

    PubMed Central

    Bianco, Simone; Corsi, Fulvio; Renò, Roberto

    2009-01-01

    We study the relation at intraday level between serial correlation and volatility of the Standard and Poor (S&P) 500 stock index futures returns. At daily and weekly levels, serial correlation and volatility forecasts have been found to be negatively correlated (LeBaron effect). After finding a significant attenuation of the original effect over time, we show that a similar but more pronounced effect holds by using intraday measures, by such as realized volatility and variance ratio. We also test the impact of unexpected volatility, defined as the part of volatility which cannot be forecasted, on the presence of intraday serial correlation in the time series by employing a model for realized volatility based on the heterogeneous market hypothesis. We find that intraday serial correlation is negatively correlated to volatility forecasts, whereas it is positively correlated to unexpected volatility.

  2. Le Point sur... Astronomie IV

    NASA Astrophysics Data System (ADS)

    Pecker, J.-C.

    Cet ouvrage regroupe des articles de mise au point sollicités par le rédacteur en chef de la rubrique Astronomie des Comptes rendus de l'Académie des sciences. Les textes se proposent de faire découvrir aux lecteurs, dans les principales disciplines de l'astronomie, les résultats les plus remarquables des dernières années.Leurs auteurs sont des spécialistes participant activement à l'accroissement des connaissances dans des domaines faisant l'objet de recherches intensives. Ces mises au point sur des questions particulièrement importantes de l'astronomie sont rédigées soit en français, soit en anglais et accompagnées d'une bibliographie détaillée.

  3. A Calorimetric Study of Almandine: Are the Thermodynamic Properties of the End-Member Aluminosilicate Garnets Finally Known Quantitatively?

    NASA Astrophysics Data System (ADS)

    Dachs, E.; Geiger, C. A.; Benisek, A.

    2012-12-01

    The aluminosilicate garnets (E3Al2Si3O12 with E = Fe2+, Mn2+, Ca, Mg) form an important rock-forming mineral group. Much study has been directed toward determining their thermodynamic properties. The iron end-member almandine (Fe3Al2Si3O12) is a key phase in many petrologic investigations. As part of an ongoing calorimetric and thermodynamic study of the aluminosilicate garnets, the heat capacity of three synthetic well-characterized polycrystalline almandine garnets and one natural almandine-rich single crystal was measured. The various garnets were characterized by optical microscopy, electron-microprobe analysis, X-ray powder diffraction and 57Fe Mössbauer spectroscopy. Heat capacity measurements were performed in the temperature range 3 to 300 K using relaxation calorimetry and between 282 and 764 K using DSC methods. From the former, So values between 336.7 ± 0.8 and 337.8 ± 0.8 J/molK are calculated for the different samples. The smaller value is considered the best So for end-member stoichiometric almandine, because it derives from the "best" Fe3+-free synthetic sample. The Cp behavior for almandine at T > 298 K is given by the polynomial (in J/molK): Cp = 649.06(±4) - 3837.57(±122)T-0.5 - 1.44682(±0.06)107T-2 + 1.94834(±0.09)109T-3, which is calculated using DSC data together with one published heat-content datum determined by transposed-drop calorimetry along with a new determination that gives H1181K - H302K = 415.0 ± 3.2 kJ/mole. Almandine shows a λ-type heat-capacity anomaly at low temperatures resulting from a paramagnetic-antiferromagnetic phase transition at about 9 K. The lattice heat capacity was calculated using the single-parameter phonon dispersion model of Komada and Westrum (1997), which allows the non-lattice heat capacity (Cex) behavior to be modelled. An analysis shows the presence of an electronic heat-capacity contribution (Cel - Schottky anomaly) around 17 K that is superimposed on a larger magnetic heat-capacity effect (Cmag

  4. New methodology for simultaneous volumetric and calorimetric measurements: Direct determination of {alpha}{sub p} and C{sub p} for liquids under pressure

    SciTech Connect

    Casas, L. M.

    2009-12-15

    A new batch cell has been developed to measure simultaneously both isobaric thermal expansion and isobaric heat capacity from calorimetric measurements. The isobaric thermal expansion is directly proportional to the linear displacement of an inner flexible below and the heat capacity is calculated from the calorimetric signal. The apparatus used was a commercial Setaram C-80 calorimeter and together with this type of vessels can be operated up to 20 MPa and in the temperature range of 303.15-523.15 K, In this work, calibration was carried out using 1-hexanol and subsequently both thermophysical properties were determined for 3-pentanol, 3-ethyl-3-pentanol, and 1-octanol at atmospheric pressure, 5 and 10 MPa, and from 303.15 to 423.15 K in temperature. Finally experimental values were compared with the literature in order to validate this new methodology, which allows a very accurate determination of isobaric thermal expansion and isobaric heat capacity.

  5. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2013-12-01

    ISON; (3200) Phaéton; Titan, lacs et hydrocarbures; Titan et le Soleil; Jets; z8_GND_5296; La nébuleuse de la Crevette; Planète isolée; Nébuleuse Toby Jug; Le pulsar du Crabe; Le bulbe de la Voie lactée; ALMA au grand complet; APEX, ArTéMiS; Sgr A*; Première détection de l’acétate de méthyle dans l’espace

  6. Calorimetric and thermomechanical properties of titanium-based orthodontic wires: DSC-DMA relationship to predict the elastic modulus.

    PubMed

    Laino, Giuliana; De Santis, Roberto; Gloria, Antonio; Russo, Teresa; Quintanilla, David Suárez; Laino, Alberto; Martina, Roberto; Nicolais, Luigi; Ambrosio, Luigi

    2012-03-01

    Orthodontic treatment is strongly dependent on the loads developed by metal wires, and the choice of an orthodontic archwire should be based on its mechanical performance. The desire of both orthodontists and engineers would be to predict the mechanical behavior of archwires. To this aim, Gum Metal (Toyota Central R&L Labs., Inc.), TMA (ORMCO), 35°C Copper NiTi (SDS ORMCO), Thermalloy Plus (Rocky Mountain), Nitinol SE (3M Unitek), and NiTi (SDS ORMCO) were tested according to dynamic mechanical analysis and differential scanning calorimetry. A model was also developed to predict the elastic modulus of superelastic wires. Results from experimental tests have highlighted that superelastic wires are very sensitive to temperature variations occurring in the oral environment, while the proposed model seems to be reliable to predict the Young's modulus allowing to correlate calorimetric and mechanical data. Furthermore, Gum Metal wire behaves as an elastic material with a very low Young's modulus, and it can be particularly useful for the initial stage of orthodontic treatments.

  7. Examination of the calorimetric spectrum to determine the neutrino mass in low-energy electron capture decay

    NASA Astrophysics Data System (ADS)

    Robertson, R. G. H.

    2015-03-01

    Background: The standard kinematic method for determining neutrino mass from the β decay of tritium or other isotope is to measure the shape of the electron spectrum near the endpoint. A similar distortion of the "visible energy" remaining after electron capture is caused by neutrino mass. There has been a resurgence of interest in using this method with 163Ho, driven by technological advances in microcalorimetry. Recent theoretical analyses offer reassurance that there are no significant theoretical uncertainties. Purpose: The theoretical analyses consider only single vacancy states in the daughter 163Dy atom. It is necessary to consider configurations with more than one vacancy that can be populated owing to the change in nuclear charge. Method: The shakeup and shake-off theory of Carlson and Nestor is used as a basis for estimating the population of double-vacancy states. Results: A spectrum of satellites associated with each primary vacancy created by electron capture is presented. Conclusions: The theory of the calorimetric spectrum is more complicated than has been described heretofore. There are numerous shakeup and shake-off satellites present across the spectrum, and some may be very near the endpoint. The spectrum shape is presently not understood well enough to permit a sensitive determination of the neutrino mass in this way.

  8. Calorimetric Low-Temperature Detectors for X-Ray Spectroscopy on Trapped Highly-Charged Heavy Ions

    NASA Technical Reports Server (NTRS)

    Kilbourne, Caroline; Kraft-Bermuth, S.; Andrianov, V.; Bleile, A.; Echler, A.; Egelhof, P.; Ilieva, S.; Kilbourne, C.; McCammon, D.

    2012-01-01

    The application of Calorimetric Low-Temperature Detectors (CLTDs) has been proposed at the Heavy-Ion TRAP facility HITRAP which is currently being installed at the Helmholtz Research Center for Heavy Ion Research GSI. This cold ion trap setup will allow the investigation of X-rays from ions practically at rest, for which the excellent energy resolution of CLTDs can be used to its full advantage. However, the relatively low intensities at HITRAP demand larger solid angles and an optimized cryogenic setup. The influence of external magnetic fields has to be taken into account. CLTDs will also be a substantial part of the instrumental equipment at the future Facility for Antiproton and Heavy Ion Research (FAIR), for which a wide variety of high-precision X-ray spectroscopy experiments has been proposed. This contribution will give an overview on the chances and challenges for the application of CLTDs at HITRAP as well as perspectives for future experiments at the FAIR facility.

  9. Inverse Temperature Dependence in Static Quenching versus Calorimetric Exploration: Binding Interaction of Chloramphenicol to β-Lactoglobulin.

    PubMed

    Ghosh, Narayani; Mondal, Ramakanta; Mukherjee, Saptarshi

    2015-07-28

    The binding interaction between the whey protein bovine β-lactoglobulin (βLG) with the well-known antibiotic chloramphenicol (Clp) is explored by monitoring the intrinsic fluorescence of βLG. Steady-state and time-resolved fluorescence spectral data reveal that quenching of βLG fluorescence proceeds through ground state complex formation, i.e., static quenching mechanism. However, the drug-protein binding constant is found to vary proportionately with temperature. This anomalous result is explained on the basis of the Arrhenius theory which states that the rate constant varies proportionally with temperature. Thermodynamic parameters like ΔH, ΔS, ΔG, and the stoichiometry for the binding interaction have been estimated by isothermal titration calorimetric (ITC) study. Thermodynamic data show that the binding phenomenon is mainly an entropy driven process suggesting the major role of hydrophobic interaction forces in the Clp-βLG binding. Constant pressure heat capacity change (ΔCp) has been calculated from enthalpy of binding at different temperatures which reveals that hydrophobic interaction is the major operating force. The inverse temperature dependence in static quenching is however resolved from ITC data which show that the binding constant regularly decreases with increase in temperature. The modification of native protein conformation due to binding of drug has been monitored by circular dichroism (CD) spectroscopy. The probable binding location of Clp inside βLG is explored from AutoDock based blind docking simulation.

  10. Calorimetric AC loss measurement of MgB2 superconducting tape in an alternating transport current and direct magnetic field

    NASA Astrophysics Data System (ADS)

    See, K. W.; Xu, X.; Horvat, J.; Cook, C. D.; Dou, S. X.

    2012-11-01

    Applications of MgB2 superconductors in electrical engineering have been widely reported, and various studies have been made to define their alternating current (AC) losses. However, studies on the transport losses with an applied transverse DC magnetic field have not been conducted, even though this is one of the favored conditions in applications of practical MgB2 tapes. Methods and techniques used to characterize and measure these losses have so far been grouped into ‘electrical’ and ‘calorimetric’ approaches with external conditions set to resemble the application conditions. In this paper, we present a new approach to mounting the sample and employ the calorimetric method to accurately determine the losses in the concurrent application of AC transport current and DC magnetic fields that are likely to be experienced in practical devices such as generators and motors. This technique provides great simplification compared to the pickup coil and lock-in amplifier methods and is applied to a long length (˜10 cm) superconducting tape. The AC loss data at 20 and 30 K will be presented in an applied transport current of 50 Hz under external DC magnetic fields. The results are found to be higher than the theoretical predictions because of the metallic fraction of the tape that contributes quite significantly to the total losses. The data, however, will allow minimization of losses in practical MgB2 coils and will be used in the verification of numerical coil models.

  11. Adsorption of arsenic ions on Brazilian sepiolite: effect of contact time, pH, concentration, and calorimetric investigation.

    PubMed

    Guerra, Denis L; Batista, Adriano C; da Costa, Paulo C Corrêa; Viana, Rúbia R; Airoldi, Claudio

    2010-06-01

    The original sepiolite clay mineral has been collected from Amazon region, Brazil. The compound 2-aminomethylpyridine (AMP) was anchored onto Amazon sepiolite surface by heterogeneous route. The natural (SPT) and modified (SPT(AMP)) sepiolite samples were characterized by elemental analysis, SEM, N(2) adsorption, and nuclear magnetic nuclei of (29)Si and (13)C. The well-defined peaks obtained in the (13)C NMR spectrum in the 0-160 ppm region confirmed the attachment of organic functional groups as pendant chains bonded into the porous clay. The ability of these materials to remove As(V) from aqueous solution was followed by a series of adsorption isotherms at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 7.26×10(-2) and 11.70×10(-2) mmol g(-1) for SPT and SPT(AMP), respectively. In order to evaluate the clay samples as adsorbents in dynamic system, a glass column was fulfilled with clay samples (1.0 g) and it was fed with 2.0×10(-2) mmol dm(-3) As(V) at pH 4.0. The energetic effects caused by metal cations adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such As(V)-nitrogen interactions.

  12. Calorimetric study of alkali and alkaline-earth cation adsorption and exchange at the quartz-solution interface.

    PubMed

    Allen, Nicholas; Machesky, Michael L; Wesolowski, David J; Kabengi, Nadine

    2017-10-15

    Cations in natural solutions significantly impact interfacial processes, particularly dissolution and surface charge measurements for quartz and silica, which are amongst the most naturally abundant and technologically important solids. Thermodynamic parameters for cation-specific interfacial reactions have heretofore been mostly derived instead of directly measured experimentally. This work investigates the energetics of adsorption and exchange reactions of alkali metal (M(+)) and alkaline earth (M(2+)) cations with the quartz surface by flow adsorption microcalorimetry, in tandem with in-situ pH measurements. The magnitudes of the heats of adsorption and exchange were found to increase along the Hofmeister series i.e., Li(+)calorimetric signals, pH data revealed kinetic differences between the adsorption and desorption reactions of M(+) and M(2+), and individual cations within each group. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Thermodynamics of H in disordered Pd-Ag alloys from calorimetric and equilibrium pressure-composition-temperature measurements.

    PubMed

    Flanagan, Ted B; Wang, Da; Luo, S

    2007-09-13

    In this research, the thermodynamics of H2 solution and hydride formation in a series of disordered Pd-Ag alloys has been determined using both reaction calorimetry and equilibrium PH2-composition-T data. Trends of DeltaHH and DeltaSH with both H and Ag concentration have been determined. For the Pd0.76Ag0.24 alloy, which does not form a hydride phase, DeltaHH and DeltaSH both exhibit minima with H/(Pd0.76Ag0.24) followed by a linear increase of the former. A linear increase of DeltaHH is found for all of the alloys in the high H content region beyond the two-phase region or, if, there is no two-phase region, in the high H content region. DeltaHH degrees at infinite dilution of H decreases with atom fraction Ag, XAg, up to about 0.40 and then increases. Enthalpies for hydride formation/decomposition, 1/2H2(g) + dilute <--> hydride, have been determined calorimetrically for alloys which form two phases (303 K). The enthalpies for hydride formation become more exothermic with XAg while the corresponding entropy magnitudes are nearly constant, 46 +/- 2 J/K mol H.

  14. Calorimetric Low-Temperature Detectors for X-Ray Spectroscopy on Trapped Highly-Charged Heavy Ions

    NASA Technical Reports Server (NTRS)

    Kilbourne, Caroline; Kraft-Bermuth, S.; Andrianov, V.; Bleile, A.; Echler, A.; Egelhof, P.; Ilieva, S.; Kilbourne, C.; McCammon, D.

    2012-01-01

    The application of Calorimetric Low-Temperature Detectors (CLTDs) has been proposed at the Heavy-Ion TRAP facility HITRAP which is currently being installed at the Helmholtz Research Center for Heavy Ion Research GSI. This cold ion trap setup will allow the investigation of X-rays from ions practically at rest, for which the excellent energy resolution of CLTDs can be used to its full advantage. However, the relatively low intensities at HITRAP demand larger solid angles and an optimized cryogenic setup. The influence of external magnetic fields has to be taken into account. CLTDs will also be a substantial part of the instrumental equipment at the future Facility for Antiproton and Heavy Ion Research (FAIR), for which a wide variety of high-precision X-ray spectroscopy experiments has been proposed. This contribution will give an overview on the chances and challenges for the application of CLTDs at HITRAP as well as perspectives for future experiments at the FAIR facility.

  15. pH-tuneable binding of 2′-phospho-ADP-ribose to ketopantoate reductase: a structural and calorimetric study

    SciTech Connect

    Ciulli, Alessio; Lobley, Carina M. C.; Tuck, Kellie L.; Smith, Alison G.; Blundell, Tom L.; Abell, Chris

    2007-02-01

    A combined crystallographic, calorimetric and mutagenic study has been used to show how changes in pH give rise to two distinct binding modes of 2′-phospho-ADP-ribose to ketopantoate reductase. The crystal structure of Escherichia coli ketopantoate reductase in complex with 2′-monophosphoadenosine 5′-diphosphoribose, a fragment of NADP{sup +} that lacks the nicotinamide ring, is reported. The ligand is bound at the enzyme active site in the opposite orientation to that observed for NADP{sup +}, with the adenine ring occupying the lipophilic nicotinamide pocket. Isothermal titration calorimetry with R31A and N98A mutants of the enzyme is used to show that the unusual ‘reversed binding mode’ observed in the crystal is triggered by changes in the protonation of binding groups at low pH. This research has important implications for fragment-based approaches to drug design, namely that the crystallization conditions and the chemical modification of ligands can have unexpected effects on the binding modes.

  16. Photophysical and calorimetric investigation on the structural reorganization of poly(A) by phenothiazinium dyes azure A and azure B.

    PubMed

    Paul, Puja; Kumar, Gopinatha Suresh

    2014-08-01

    Poly(A) has significant relevance to mRNA stability, protein synthesis and cancer biology. The ability of two phenothiazinium dyes azure A (AA) and azure B (AB) to bind single-stranded poly(A) was studied by spectroscopic and calorimetric techniques. Strong binding of the dyes and the higher affinity of AA over AB were ascertained from absorbance and fluorescence experiments. Significant perturbation of the circular dichroism spectrum of poly(A) in the presence of these molecules with formation of induced CD bands in the 300-700 nm region was observed. Strong emission polarization of the bound dyes and strong energy transfer from the adenine base pairs of poly(A) suggested intercalative binding to poly(A). Intercalative binding was confirmed from fluorescence quenching experiments and was predominantly entropy driven as evidenced from isothermal titration calorimetry data. The negative values of heat capacity indicated involvement of hydrophobic forces and enthalpy-entropy compensation suggested noncovalent interactions in the complexation for both the dyes. Poly(A) formed a self-assembled structure on the binding of both the dyes that was more favored under higher salt conditions. New insights in terms of spectroscopic and thermodynamic aspects into the self-structure formation of poly(A) by two new phenothiazinium dyes that may lead to structural and functional damage of mRNA are revealed from these studies.

  17. Surfactants induced release of a red emitting dye from the nanocavity of a molecular container: A spectroscopic and calorimetric study.

    PubMed

    Ahmed, Sayeed Ashique; Chatterjee, Aninda; Maity, Banibrata; Seth, Debabrata

    2016-08-01

    Supramolecular interaction of a red emitting dye Nile blue A (NBA) with Cucurbit[7]uril (CB7) in aqueous solution was studied and the release of the dye from the hydrophobic cavity of CB7 was reported. To investigate the supramolecular host-guest complex formation and release of dye, we have used the steady state absorption, fluorescence and time resolved fluorescence emission spectroscopy, (1)H NMR spectroscopy and isothermal titration calorimetry (ITC). The spectral properties of NBA were changed in the presence of CB7. The change in spectral features of NBA in presence of CB7 indicates the formation of supramolecular host-guest complexes. By using the SED equation the diameter of the complex was estimated. The complex formation further affirmed by the (1)H NMR study. Upfield and downfield shifts of the protons of NBA was observed in both the aliphatic and aromatic region. From the ITC measurement, we have drawn up the forces involved for the complexation of NBA with CB7. We have studied the release of NBA from the hydrophobic cavity of CB7 by using ionic, neutral surfactants and ionic liquid with the help of spectroscopic and calorimetric techniques. It is observed that on addition of SDS and ionic liquid (

  18. Refractive-index-based calorimetric studies of RNAse T1 unfolding in small volumes using microinterferometric backscatter

    NASA Astrophysics Data System (ADS)

    Houlne, Michael P.; Hubbard, Darren S.; Makhatadze, George I.; Bornhop, Darryl J.

    1997-05-01

    Micro-interferometry, a novel technique developed by the authors, employs a linearly polarized laser, a fused silica capillary tube housing for the sample and a charged coupled device as a detector. A back scattered interference pattern, observed as a high contrast fringes, is produced when the laser is directed onto the capillary containing the sample. The positional change of the fringe pattern is a function of the refractive index of the media in the capillary. In the present work, the RNA enzyme RNase T1 is heated in the sample cell over a temperature range of 30 degrees C to 60 degrees C. Over this temperature range the molecule unfolds form the quaternary to the tertiary structure. This structure change is manifested as a refractive index change and is observed by monitoring the fringe position while ramping the cell temperature in a controlled fashion. From the refractive index response over the temperature range, the Gibbs free energy associated with unfolding is calculated. The authors show milli-degree temperature stability with a 0.1 micro-liter probe volume, thus demonstrating the application of this device in micro- calorimetric investigations.

  19. Jan Potocki et le "Gothic Novel"

    ERIC Educational Resources Information Center

    Finne, Jacques

    1970-01-01

    Establishes a parallel between the supernatural and fantastic qualities of Le Comte Jan Potocki's literary works, and the English gothic novels by comparing the elements of terror, mysterious atmosphere, and the supernatural beings involved. (DS)

  20. Jan Potocki et le "Gothic Novel"

    ERIC Educational Resources Information Center

    Finne, Jacques

    1970-01-01

    Establishes a parallel between the supernatural and fantastic qualities of Le Comte Jan Potocki's literary works, and the English gothic novels by comparing the elements of terror, mysterious atmosphere, and the supernatural beings involved. (DS)

  1. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2006-06-01

    Deep Impact; Comète 73P/Schwassmann-Wachmann 3; L'anneau bleu d'Uranus; Triplet de neptunes; Triton; Dunes de Titan; Aréologie; Tache Rouge Junior; Obliquité des grosses planètes; Le jour de Saturne; Xéna; Un compagnon pour le Soleil; Galaxies satellites; Séisme sur une étoile à neutrons; Trou noir double; Hydrogène lointain

  2. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2006-02-01

    le errant; Pluton et Charon; Du côté d'Uranus !; Stardust; G29-38; La chasse aux planètes; Étoile polaire; Véga; Vers un interféromètre infrarouge à base kilométrique; Des pulsars extraordinaires; Trous noirs intermédiaires; Le trou noir central de la Galaxie; N44; Tornade spatiale

  3. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2005-03-01

    Trou noir glouton, Matière noire, Integral et le centre de notre Galaxie, Essaim de trous noirs, Carrousel autour de trous noirs, Érosion de trous noirs, Un quasar dans NGC 7319?, Distance de T Tauri, Chai non manquant, Des planètes autour d'une naine brune?, Titan, Une quatrième planète pour le pulsar PSR B1257+12, Smart 1, Aurores de Saturne

  4. La Vie Politique sous la Restauration a Travers ’Le Rouge et le Noir’ de Stendahl (The Political Life during the Restauration as Depicted in Le Rouge et le Noir by Stendahl)

    DTIC Science & Technology

    1989-01-01

    Valenod et Moirod, qul hissent le drapeau lib6ral uniquenient pour aznoIiorer leurs propres 20 conditions. Ils n’ont ni souci pour les paysans ni... propre benefice. Le lecteur est introduit a M. Valenod tres t~t dans le livre. 11 est le directeur du depot de mendicit6 A Verrlieres qui craint la visite... propres desse ins. Le groupe de vrais lib~t-aux stendhal lens comprend Fouqu6 qui est le bon ami de Julilen Sorel , le phi losophe Saint- Giraud. et

  5. Evaluation of carbon and nitrogen pools in different soil types amended with different organic inputs by thermogravimetric/calorimetric analysis

    NASA Astrophysics Data System (ADS)

    Yanardaǧ, Ibrahim H.; Zornoza, Raúl; Büyükkiliç-Yanardaǧ, Asuman; Acosta, Jose A.; Faz, Ángel; Mermut, Ahmet R.

    2017-04-01

    The objective of this study was to assess the short-term changes in soil organic C (SOC) and N pools after incubation of three different soil types (Regosol, Luvisol and Kastanozem) treated with three amendments differing in organic matter stability (raw pig slurry (PS), manure, and biochar (BC), and to establish relationships between different chemical, spectral and thermal/calorimetric data to assess if thermal/calorimetric analysis could replace conventional analyses to monitor changes in SOC and N poos. Thermogravimetry-Differential Scanning Calorimetry (TG-DSC) analysis showed that amendments had little effect on volatile SOC and inorganic matter, compared to unamended samples in all soils. All amendments significantly increased the labile SOC in Regosol. Manure and BC increased recalcitrant SOC in Regosol and Luvisol. BC significantly increased recalcitrant SOC in all soils. Refractory SOC slightly increased with amendments in the Luvisol compared to the control. These results support the findings obtained with chemical analyses. Selected evolved ions (m/z 30 and 44) detected by quadrupole mass spectrometry (QMS) confirmed findings from TG-DSC. Emissions of C and N containing gases from the Regosol significantly increased with the amendments because this soil contains low SOC content, and the application of these amendments provided additional C. An increase in the CO2 containing gas species (m/z 44) from volatile SOC was observed with PS application only in the Regosol. Carbon dioxide increments (m/z 44) from recalcitrant (380-475°C) and refractory (475-550/600°C) SOC pools were observed with all amendments in all soils especially with BC application. The evolved ions at m/z 44 were higher in the initial soil samples from Kastanozem than after incubation, suggesting a loss of organic compounds, mainly volatile and labile upon incubation. NO peaks (m/z 30) showed similar trends to the C containing gas species in all soils. We carried out linear regressions

  6. Entrevue avec le Dr Charley Zeanah

    PubMed Central

    2013-01-01

    Le Dr Charles Zeanah est titulaire de la chaire de psychiatrie Mary K. Sellars-Polchow, professeur de pédiatrie clinique et vice-président de la pédopsychiatrie au département de psychiatrie et des sciences du comportement de la faculté de médecine de l’Université Tulane, à la Nouvelle-Orléans. Il est également directeur général de l’institut de la santé mentale des nourrissons et des jeunes enfants de Tulane. Il est récipiendaire de nombreux prix, notamment le prix de prévention Irving Phillips (AACAP), la mention élogieuse présidentielle pour sa recherche et son leadership exceptionnels en santé mentale des nourrissons (American Orthopsychiatric Association), le prix d’excellence clinique Sarah Haley Memorial (International Society for Traumatic Stress Studies), le prix de recherche en pédopsychiatrie Blanche F. Ittelson (APA), et le prix Serge Lebovici Award soulignant les contributions internationales à la santé mentale des nourrissons (World Association for Infant Mental Health). Le Dr Zeanah est fellow distingué de l’AACAP, fellow distingué de l’APA et membre du conseil d’administration de Zero to Three. Il est l’éditeur scientifique de Handbook of Infant Mental Health (3e édition) qui est considéré comme étant le manuel de pointe et la référence de base du domaine de la santé mentale des nourrissons.

  7. Energetics of the binding of phototoxic and cytotoxic plant alkaloid sanguinarine to DNA: Isothermal titration calorimetric studies

    NASA Astrophysics Data System (ADS)

    Adhikari, Anupam; Hossain, Maidul; Maiti, Motilal; Suresh Kumar, Gopinatha

    2008-10-01

    Sanguinarine is a medically important plant alkaloid with remarkable pharmacological and biological activities. DNA binding is considered to be an important aspect in its mode of action. Isothermal titration calorimetric technique was used for the first time to derive the thermodynamic aspects of the interaction of the phototoxic and cytotoxic plant alkaloid sanguinarine with natural calf thymus DNA and four synthetic DNAs of differing base pair sequences under various environmental conditions The affinity of binding of sanguinarine (iminium form) was found to be in the order of 10 5 M -1 to calf thymus DNA. The binding affinity to calf thymus DNA decreased with increase of ionic strength and temperature. The salt dependence of the binding data showed that release of 0.55 U of the cations per bound alkaloid. The binding of the iminium form was exothermic under all conditions, but the uncharged alkanolamine form showed no binding to DNA. The heat capacity changes obtained from the temperature dependence of enthalpy indicated a value of -140 cal/mol K. Sanguinarine showed high specificity to alternating purine-pyrimidine sequences with affinity of the order 10 6 M -1 and the affinity to the polynucleotides varied in the order poly(dG-dC)·poly(dG-dC) > poly(dA-dT)·poly(dA-dT) > poly(dA)·poly(dT) > poly(dG)·poly(dC). The binding to alternating GC polymer was exothermic and enthalpy driven, to the homo GC polymer was exothermic and favoured by both negative enthalpy and positive entropy changes, to the alternating AT polymer was exothermic and enthalpy driven while to the homo AT polymer was endothermic and entropy driven.

  8. Calorimetric investigation of triazole-bridged Fe(II) spin-crossover one-dimensional materials: measuring the cooperativity.

    PubMed

    Roubeau, Olivier; Castro, Miguel; Burriel, Ramón; Haasnoot, Jaap G; Reedijk, Jan

    2011-03-31

    The relevance of abrupt magnetic and optical transitions exhibiting bistability in spin-crossover solids has been pointed out for their potential applications in optical or memory devices. In this respect, triazole-based one-dimensional coordination polymers are widely recognized as one of the most interesting systems. The measure of the interaction among spin-crossover centers at the origin of such cooperative behavior is of paramount importance and has so far been realized through modeling of spin-crossover curves derived mostly from magnetic measurements. Here, a new series of triazole-based one-dimensional coordination polymers of formula [Fe(Rtrz)(3)](A)(2)·xH(2)O with R = methoxyethyl and A = monovalent anion has been prepared that show complete and abrupt spin-crossover phenomenon as shown by magnetic measurements. The spin-crossover transition in these and related compounds is studied by differential scanning calorimetry, and the thermodynamic excess enthalpies and entropies associated with the phenomenon are derived systematically. Then the cooperative character of the spin-crossover in these materials is quantified by use of two widely used models, so-called Slichter and Drickamer and domain models. The same procedure is applied to spin-crossover curves of similar compounds available in the literature and for which calorimetric studies have been reported. The experimental thermodynamic figures, in particular the excess enthalpies, are shown to be clearly correlated to the output parameters of both models, thus providing a direct, experimental, quantitative measure of the cooperative character of the spin-crossover phenomenon.

  9. Localized Recrystallization in Cast Al-Si-Mg Alloy during Solution Heat Treatment: Dilatometric and Calorimetric Studies

    NASA Astrophysics Data System (ADS)

    Chaudhury, S. K.; Warke, V.; Shankar, S.; Apelian, D.

    2011-10-01

    During heat treatment, the work piece experiences a range of heating rates depending upon the sizes and types of furnace. When the Al-Si-Mg cast alloy is heated to the solutionizing temperature, recrystallization takes place during the ramp-up stage. The effect of heating rate on recrystallization in the A356 (Al-Si-Mg) alloy was studied using dilatometric and calorimetric methods. Recrystallization in as-cast Al-Si alloys is a localized event and is confined to the elasto-plastic zone surrounding the eutectic Si phase; there is no evidence of recrystallization in the center of the primary Al dendritic region. The size of the elasto-plastic zone is of the same order of magnitude as the Si particles, and recrystallized grains are observed in the elasto-plastic region near the Si particles. The coefficient of thermal expansion of Al is an order of magnitude greater than Si, and thermal stresses are generated due to the thermal mismatch between the Al phase and Si particles providing the driving force for recrystallization. In contrast, recrystallization in Al wrought alloy (7075) occurs uniformly throughout the matrix, stored energy due to cold work being the driving force for recrystallization in wrought alloys. The activation energy for recrystallization in as-cast A356 alloy is 127 KJ/mole. At a slow heating rate of 4.3 K/min, creep occurs during the heating stage of solution heat treatment. However, creep does not occur in samples heated at higher heating rates, namely, 520, 130, and 17.3 K/min.

  10. Preliminary study on heat load using calorimetric measurement during long-pulse high-performance discharges on EAST

    NASA Astrophysics Data System (ADS)

    Liu, Y. K.; Hamada, N.; Hanada, K.; Gao, X.; Liu, H. Q.; Yu, Y. W.; Qian, J. P.; Yang, L.; Xu, T. J.; Jie, Y. X.; Yao, Y.; Wang, S. S.; Xu, J. C.; Yang, Z. D.; Li, G. S.; EAST Team

    2017-04-01

    Experimental Advanced Superconducting Tokamak (EAST) aims to demonstrate steady-state advanced high-performance H-mode plasmas with an ITER-like configuration, plasma control and heating schemes. The plasma-facing components in EAST are actively cooled, providing good conditions for researching long-pulse and high-energy discharges. A long-pulse high-performance plasma discharge (#59892 discharge) of up to 103 s with a core electron temperature of up to 4.5 keV was sustained with an injected energy exceeding 0.22 GJ in the 2015–2016 experimental campaign. A calorimetric measurement utilizing the temperature increment of cooling water is carried out to calculate the heat load on the strike point region of the lower divertor during long-pulse discharges in EAST. For the long-pulse and high-energy discharges, the comparison of the measurement results for the heat load measured by divertor Langmuir probes and the calorimetry diagnostic indicates that most of the heat load is delivered to the divertor panels as plasma, not radiation, and charge exchange neutrals. The ratio of the heat load on the strike point region of the lower divertor to the total injected energy is on average 42.5% per discharge with the lower single null divertor configuration. If the radiated energy loss measured by the fast bolometer diagnostic is taken into consideration, the ratio is found to be 61.6%. The experimental results and the analysis of the physics involved in these discharges are reported and discussed.

  11. Exploring the comparative binding aspects of benzophenanthridine plant alkaloid chelerythrine with RNA triple and double helices: a spectroscopic and calorimetric approach.

    PubMed

    Haque, Lucy; Pradhan, Ankur Bikash; Bhuiya, Sutanwi; Das, Suman

    2015-07-14

    A comparative study on the interaction of a benzophenanthridine alkaloid chelerythrine (CHL) with RNA triplex poly(U).poly(A)*poly(U) (hereafter U.A*U, .(dot) and *(asterisk) represent Watson-Crick and Hoogsteen base pairing respectively) and its parent duplex poly(A).poly(U) (A.U) was carried out by using a combination of various spectroscopic, viscometric and calorimetric techniques. The interaction was characterized by hypochromic and bathochromic effects in the absorption spectrum, the increase of thermal melting temperature, enhancement in solution viscosity, and perturbation in the circular dichroic spectrum. The binding constant calculated by using spectrophotometric data was in the order of 10(5) for both forms of RNA, but it was greater for triplex RNA (30.2 × 10(5) M(-1)) than duplex RNA (3.6 × 10(5) M(-1)). Isothermal titration calorimetric data are in good agreement with the spectrophotometric data. The data indicated stronger binding of CHL to the triplex structure of RNA compared to the native duplex structure. Thermal melting studies indicated greater stabilization of the Hoogsteen base paired third strand of the RNA triplex compared to its Watson-Crick strands. The mode of binding of CHL to both U.A*U and A.U was intercalation as revealed from fluorescence quenching, viscosity measurements and sensitization of the fluorescence experiment. Thermodynamic data obtained from isothermal calorimetric measurements revealed that association was favoured by both a negative enthalpy change and a positive entropy change. Taken together, our results suggest that chelerythrine binds and stabilizes the RNA triplex more strongly than its respective parent duplex. The results presented here may be useful for formulating effective antigene strategies involving benzophenanthridine alkaloids and the RNA triplex.

  12. Biomoleküle in Bewegung: Proteindynamik

    NASA Astrophysics Data System (ADS)

    Parak, Fritz G.

    2004-11-01

    Viele Proteinmoleküle sind kleine Maschinen. Im Stillstand ist ihr Aufbau wohlbekannt. Doch wie sie arbeiten, ist meistens unklar. Die Grundlagen dieser Proteindynamik werden am Beispiel des Sauerstoffspeicher-Proteins Myoglobin physikalisch untersucht. Dabei ist die Mößbauer-Spektroskopie am Hämeisen besonders hilfreich. Während sich das Myoglobin bei sehr tiefen Temperaturen in einem festkörperähnlichen Standby-Modus befindet, werden oberhalb einer charakteristischen Temperatur im Molekül proteinspezifische Bewegungsmoden aktiviert. Sie lassen sich als langsame, diffusionsartige Fluktuationen von Molekülsegmenten um die mittlere Struktur beschreiben. Diese Moden öffnen Kanäle in das Proteininnere, durch die Sauerstoffmoleküle zur Hämgruppe gelangen können. So ermöglichen sie Strukturänderungen, die für die biologische Funktion entscheidend sind.

  13. Les Brulures Chimiques Par Le Laurier Rose

    PubMed Central

    Bakkali, H.; Ababou, M.; Nassim Sabah, T.; Moussaoui, A.; Ennouhi, A.; Fouadi, F.Z.; Siah, S.; Ihrai, H.

    2010-01-01

    Summary Le laurier rose ou Nerium oleander est un arbuste qui pousse naturellement dans les régions méditerranéennes. Au Maroc on le trouve dans les lieux humides. Il est réputé par ses risques de toxicité systémique en cas d'empoisonnement à cause de la présence de deux alcaloïdes, surtout l'oléandrine. La littérature illustre des cas d'utilisation locale des feuilles de cette plante contre la gale, les hémorroïdes et les furoncles. Nous rapportons deux cas de brûlures chimiques par le laurier rose de gravité différente. Cela doit aboutir à une information élargie de la population, ainsi qu'une réglementation stricte de sa commercialisation. PMID:21991211

  14. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2002-09-01

    Jeunes étoiles et vieilles galaxies; Chiens de Chasse; Des images en partie belges; Détection chimique de planètes?; Amas cannibale; Le pulsar œil de bœuf; Supernova 2002 DJ; Centaurus A; Et de cent; Près du trou noir; Un cratère sous la Merdu Nord; Des astéroï des frôlent la Terre; Photons fatigués; Taches solaires; Un grand lac martien; Les naines brunes en infrarouge; Bourrelet équatorial; Fusion de trous noirs; Le hamburger de Gomez; Matière sombre; Non aux étoiles à quarks

  15. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2005-06-01

    Rosetta, Deep Impact, Titan Cratère sur Titan, Point chaud sur Titan, Phoebé, Treize nouvelles lunes pour Saturne, Épiméthée, Le mystère d'Amalthée, L'anomalie Pioneer, 2M1207, Oui, c'est une planète, Mini cratères martiens, On a retrouvé le Mars Polar Lander, Au Soleil toute l'année, Amplification cosmique, Hubble a quinze ans, Collision de vents dans WR 140, Création d'un trou noir, Un anneau d'Einstein presque parfait, Super flares, Mira en X

  16. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2014-06-01

    Future lune ? - L'âge de la Lune - Des volcans actifs sur Vénus - Un lac dans le cratère Gusev ? - Météorites et atmosphère martiennes - L’hexagone de Saturne - Pluton - Exo-Terre - Bêta Pictoris b - Cérès et Vesta depuis Mars - Naine froide - Parallaxes par Hubble - L2 Puppis et le sort du Soleil - Supernova et lentille gravitationnelle - Champ magnétique galactique - L’objet de Sakurai - Fermi et la matière noire - Lentille naine

  17. Le continu contre l'espace

    NASA Astrophysics Data System (ADS)

    Salanskis, Jean-Michel

    Disons pour conclure que, en tout état de cause, la façon de concevoir philosophiquement le conflit du continu et de l'espace que nous avons trouvée chez Hegel n'est pas homogène avec le style et les modalités de la pensée mathématique: 1) d'une part, le lien classique, le lien de référence entre continu et espace en mathématiques n'est pas que l'espace serait premier et privé de pensée, et le continu second, venant dissoudre l'espace en apportant la qualité, l'infini et la pensée, mais tout au contraire, il consiste en ce que l'espace est fondé sur l'abîme infinitaire du continu ; 2) d'autre part, l'éventuel divorce entre l'espace et le continu dans l'aire mathématique n'est pas celui d'une réflexivité purement conceptuelle du continu avec un positivisme géométrique, n'équivaut pas à une rupture disciplinaire ; il est plutôt le symptôme de la dérive d'une herméneutique à l'égard d'une autre, au sein d'un continent juridique commun définissant la discipline (la mathématique ensembliste), cette dérive pouvant, à la limite, induire une refonte de ce sol juridique, sans que jamais il soit question pour autant de nier l'unité des mathématiques, à comprendre ici comme l'unité ultime de responsabilité de la communauté mathématique à l'égard des trois questions Qu'est-ce que l'espace?”, “Qu'est-ce que le continu?” et “Qu'est-ce que l'infini?”.

  18. Thermodynamics of aggregate formation between a non-ionic polymer and ionic surfactants: An isothermal titration calorimetric study.

    PubMed

    Patel, Salin Gupta; Bummer, Paul M

    2017-01-10

    This report examines the energetics of aggregate formation between hydroxypropyl methylcellulose (HPMC) and model ionic surfactants including sodium dodecyl sulfate (SDS) at pharmaceutically relevant concentrations using the isothermal titration calorimetry (ITC) technique and a novel treatment of calorimetric data that accounts for the various species formed. The influence of molecular weight of HPMC, temperature and ionic strength of solution on the aggregate formation process was explored. The interaction between SDS and HPMC was determined to be an endothermic process and initiated at a critical aggregation concentration (CAC). The SDS-HPMC interactions were observed to be cooperative in nature and dependent on temperature and ionic strength of the solution. Molecular weight of HPMC significantly shifted the interaction parameters between HPMC and SDS such that at the highest molecular weight (HPMC K-100M;>240kDa), although the general shape of the titration curve (enthalpogram) was observed to remain similar, the critical concentration parameters (CAC, polymer saturation concentration (Csat) and critical micelle concentration (CMC)) were significantly altered and shifted to lower concentrations of SDS. Ionic strength was also observed to influence the critical concentration parameters for the SDS-HPMC aggregation and decreased to lower SDS concentrations with increasing ionic strength for both anionic and cationic surfactant-HPMC systems. From these data, other thermodynamic parameters of aggregation such as ΔHagg(°), ΔGagg(°), Hagg(°), ΔSagg(°), and ΔCp were calculated and utilized to postulate the hydrophobic nature of SDS-HPMC aggregate formation. The type of ionic surfactant head group (anionic vs. cationic i.e., dodecyltrimethylammonium bromide (DTAB)) was found to influence the strength of HPMC-surfactant interactions wherein a distinct CAC signifying the strength of HPMC-DTAB interactions was not observed. The interpretation of the

  19. Calorimetric and acoustic emission study of martensitic transformation in single-crystalline Ni2MnGa alloys

    NASA Astrophysics Data System (ADS)

    Tóth, László Z.; Szabó, Sándor; Daróczi, Lajos; Beke, Dezső L.

    2014-12-01

    The jerky character of austenite-martensite phase transformation in Ni2MnGa single crystals (with 10M martensite structure) has been investigated by thermal cycling using a differential scanning calorimeter (DSC) and by detection of acoustic emissions (AEs) at low cooling and heating rates (0.1 K/min and below). It is illustrated that, besides the low cooling and heating rate, mass and surface roughness are also important parameters in optimizing the best signal/noise ratio in order to obtain individual peaks suitable for statistical analysis. Three types of samples, differing in the twin structure and twin boundary behavior, were investigated with and without surface roughening made by electro-erosion. The statistical analysis, carried out for both (thermal and acoustic) types of signals, provided power-law behavior. In calorimetric measurements the energy exponents, obtained in cooling, were the same within the experimental errors (ɛ =1.7 ±0.2 ) for the three samples investigated. In acoustic emission experiments the energy and amplitude, α , exponents were determined both for cooling and heating. The exponents for cooling and heating runs are slightly different. They are larger for heating for both α and ɛ , in accordance with the asymmetric acoustic activity: we observed higher acoustic activity (higher number of hits) during cooling. The effect of the surface roughness is negligible in the exponents (but higher acoustic activity corresponds to higher roughness) and the following values were obtained: ɛ =1.5 ±0.1 and α =2.1 ±0.1 for cooling as well as ɛ =1.8 ±0.1 and α =2.6 ±0.1 for heating. Our results are in accordance with the results of Gallardo et al. [Phys. Rev. B 81, 174102 (2010), 10.1103/PhysRevB.81.174102] obtained in Cu based alloys: the exponents of the energy distributions, for both DSC and AE signals, were the same within the experimental errors. Furthermore, our exponents obtained from the AE measurements are close to the values

  20. Trophic relay and prey switching - A stomach contents and calorimetric investigation of an ambassid fish and their saltmarsh prey

    NASA Astrophysics Data System (ADS)

    McPhee, Jack J.; Platell, Margaret E.; Schreider, Maria J.

    2015-12-01

    Trophic relay is an ecological model that involves the movement of biomass and energy from vegetation, such as saltmarshes, within estuaries to the open sea via a series of predator-prey relationships. Any potential for trophic relay is therefore affected by water movements within an estuary and by the ability of a predator to "switch" prey in response to fluctuating abundances of those prey. Saltmarsh-dwelling grapsid crabs, which feed on saltmarsh-derived detritus and microphytobenthos, release zoeae into ebbing tides that inundate saltmarshes during spring-tide cycles within tidally-dominated estuaries, such as Brisbane Water Estuary, therefore providing an opportunity to examine whether prey-switching and/or trophic relay may occur in fish that feed on those zoeae (such as the highly abundant estuarine ambassid, Ambassis jacksoniensis). This model was examined by sampling A. jacksoniensis near saltmarshes in a large, temperate south-eastern Australian estuary during flood and ebb tides on days of saltmarsh inundation and non-inundation over four spring-tide events in 2012. Stomach fullnesses of A. jacksoniensis were generally highest during ebb tides on days of saltmarsh inundation, implying that feeding was most marked at these times. Caridean decapods dominated diets during flood tides and on days of no saltmarsh inundation, while crab zoeae dominated diets during ebb tides and on days of inundation, suggesting that, when saltmarsh-derived zoeae became abundant, A. jacksoniensis switched to feeding on those prey. Three potential zooplankton prey (calanoid copepods, caridean decapods and crab zoeae) did not differ calorimetrically, indicating that switching of prey by A. jacksoniensis is not directly related to their preying on energetically greater prey, but reflects opportunistic feeding on more abundant and/or less elusive prey. As A. jacksoniensis is able to switch prey from estuarine caridean decapods to saltmarsh-derived crab zoeae, this very abundant

  1. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2008-04-01

    Jets stellaires; Structure géante et matière noire; Un mini-système solaire; Arcs gravitationnels et images multiples; Choc frontal dans notre Galaxie; Avalanches martiennes; Du sable autour de KH 15D; Le cratère de Carancas; Smart-1;

  2. Le Chatelier's principle in replicator dynamics

    NASA Astrophysics Data System (ADS)

    Allahverdyan, Armen E.; Galstyan, Aram

    2011-10-01

    The Le Chatelier principle states that physical equilibria are not only stable, but they also resist external perturbations via short-time negative-feedback mechanisms: a perturbation induces processes tending to diminish its results. The principle has deep roots, e.g., in thermodynamics it is closely related to the second law and the positivity of the entropy production. Here we study the applicability of the Le Chatelier principle to evolutionary game theory, i.e., to perturbations of a Nash equilibrium within the replicator dynamics. We show that the principle can be reformulated as a majorization relation. This defines a stability notion that generalizes the concept of evolutionary stability. We determine criteria for a Nash equilibrium to satisfy the Le Chatelier principle and relate them to mutualistic interactions (game-theoretical anticoordination) showing in which sense mutualistic replicators can be more stable than (say) competing ones. There are globally stable Nash equilibria, where the Le Chatelier principle is violated even locally: in contrast to the thermodynamic equilibrium a Nash equilibrium can amplify small perturbations, though both types of equilibria satisfy the detailed balance condition.

  3. Le Chatelier's principle in replicator dynamics.

    PubMed

    Allahverdyan, Armen E; Galstyan, Aram

    2011-10-01

    The Le Chatelier principle states that physical equilibria are not only stable, but they also resist external perturbations via short-time negative-feedback mechanisms: a perturbation induces processes tending to diminish its results. The principle has deep roots, e.g., in thermodynamics it is closely related to the second law and the positivity of the entropy production. Here we study the applicability of the Le Chatelier principle to evolutionary game theory, i.e., to perturbations of a Nash equilibrium within the replicator dynamics. We show that the principle can be reformulated as a majorization relation. This defines a stability notion that generalizes the concept of evolutionary stability. We determine criteria for a Nash equilibrium to satisfy the Le Chatelier principle and relate them to mutualistic interactions (game-theoretical anticoordination) showing in which sense mutualistic replicators can be more stable than (say) competing ones. There are globally stable Nash equilibria, where the Le Chatelier principle is violated even locally: in contrast to the thermodynamic equilibrium a Nash equilibrium can amplify small perturbations, though both types of equilibria satisfy the detailed balance condition.

  4. Le Chatelier--Right or Wrong?

    ERIC Educational Resources Information Center

    Helfferich, Friedrich G.

    1985-01-01

    Presents a class exercise designed to find out how well students understand the nature and consequences of the mass action law and Le Chatelier's principle as applied to chemical equilibria. The exercise relates to a practical situation and provides simple relations for maximizing equilibrium quantities not found in standard textbooks. (JN)

  5. Microscopic Description of Le Chatelier's Principle

    ERIC Educational Resources Information Center

    Novak, Igor

    2005-01-01

    A simple approach that "demystifies" Le Chatelier's principle (LCP) and simulates students to think about fundamental physical background behind the well-known principles is presented. The approach uses microscopic descriptors of matter like energy levels and populations and does not require any assumption about the fixed amount of substance being…

  6. Le Chatelier's Principle, Temperature Effects, and Entropy.

    ERIC Educational Resources Information Center

    Campbell, J. Arthur

    1985-01-01

    One of the most useful methods of understanding chemical equilibria is provided by Le Chatelier's principle. The relationships between this principle, temperature, and entropy are discussed. Tables with thermodynamic data for some net reactions commonly used to illustrate the principle and for reactions involving gases are included. (JN)

  7. Le Francais Courant: Part V, French.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    Instructional objectives of the Dade County Public Schools Quinmester Program in French for use with "Le Francais Courant: Part 5" focus on the development of mastery of the basic numbering system and other grammatical structures. Structures include the formation of the present tense of the irregular verbs…

  8. A Compositional Analysis of "-GUO" and "-LE."

    ERIC Educational Resources Information Center

    Mangione, L.; Li, Dingxuan

    1993-01-01

    Paper examines interaction of semantic contributions of aspect markers "-guo" and "-le"; negative adverbs "bu" and "mei"; and two classes of verbs. Proposed analysis systematically accounts for temporal orientation of members of several classes of sentences in terms of aspectual contributions made by two aspect markers, negative adverbs, verbs,…

  9. Technical Programme 1993 (Le Programme Technique, 1993)

    DTIC Science & Technology

    1992-09-01

    Symposium sur "Les Effets de la Propagation Atmospherique a travers des Obscurcissants Naturels et Artificiels sur le Rayonnement des Ondes Millimetriques...for Small Gas Turbines" Reunion du Panel et Symposium sur "Les Technologies pour les Petites Turbines a Gaz " 4-8 CANADA TIP Panel Meeting/Specialists

  10. The Great Spanish "Le-Lo" Controversy

    ERIC Educational Resources Information Center

    Roldan, Mercedes

    1975-01-01

    The distinction between the clitics "le" and "lo" is different for Peninsular Spanish than for Latin American Spanish but is in both cases systematic. The division in Castilian Spanish is along the line of animate-inanimate. The Latin American division is between accusative and dative case. (TL)

  11. A Compositional Analysis of "-GUO" and "-LE."

    ERIC Educational Resources Information Center

    Mangione, L.; Li, Dingxuan

    1993-01-01

    Paper examines interaction of semantic contributions of aspect markers "-guo" and "-le"; negative adverbs "bu" and "mei"; and two classes of verbs. Proposed analysis systematically accounts for temporal orientation of members of several classes of sentences in terms of aspectual contributions made by two aspect markers, negative adverbs, verbs,…

  12. 30. INTERIOR VIEW OF MISSISSIPPI RIVER RECREATION OFFICE, LE CLAIRE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. INTERIOR VIEW OF MISSISSIPPI RIVER RECREATION OFFICE, LE CLAIRE BASE COMPOUND, LOOKING EAST - Mississippi River 9-Foot Channel, Lock & Dam No. 14, Upper Mississippi River, Le Claire, Scott County, IA

  13. 29. INTERIOR VIEW OF MISSISSIPPI RIVER RECREATION OFFICE BUILDING, LE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. INTERIOR VIEW OF MISSISSIPPI RIVER RECREATION OFFICE BUILDING, LE CLAIRE BASE COMPOUND, LOOKING WEST - Mississippi River 9-Foot Channel, Lock & Dam No. 14, Upper Mississippi River, Le Claire, Scott County, IA

  14. Direct calorimetric measurement of enthalpy of adsorption of carbon dioxide on CD-MOF-2, a green metal-organic framework.

    PubMed

    Wu, Di; Gassensmith, Jeremiah J; Gouvêa, Douglas; Ushakov, Sergey; Stoddart, J Fraser; Navrotsky, Alexandra

    2013-05-08

    The enthalpy of adsorption of CO2 on an environmentally friendly metal-organic framework, CD-MOF-2, has been determined directly for the first time using adsorption calorimetry at 25 °C. This calorimetric methodology provides a much more accurate and model-independent measurement of adsorption enthalpy than that obtained by calculation from the adsorption isotherms, especially for systems showing complex and strongly exothermic adsorption behavior. The differential enthalpy of CO2 adsorption shows enthalpy values in line with chemisorption behavior. At near-zero coverage, an irreversible binding event with an enthalpy of -113.5 kJ/mol CO2 is observed, which is followed by a reversible -65.4 kJ/mol binding event. These enthalpies are assigned to adsorption on more and less reactive hydroxyl groups, respectively. Further, a second plateau shows an enthalpy of -40.1 kJ/mol and is indicative of physisorbed CO2. The calorimetric data confirm the presence of at least two energetically distinct binding sites for chemisorbed CO2 on CD-MOF-2.

  15. Identifying the critical point of the weakly first-order itinerant magnet DyCo2 with complementary magnetization and calorimetric measurements

    NASA Astrophysics Data System (ADS)

    Morrison, K.; Dupas, A.; Mudryk, Y.; Pecharsky, V. K.; Gschneidner, K. A.; Caplin, A. D.; Cohen, L. F.

    2013-04-01

    We examine the character of the itinerant magnetic transition of DyCo2 by different calorimetric methods, thereby separating the heat capacity and latent heat contributions to the entropy—allowing direct comparison to other itinerant electron metamagnetic systems. The heat capacity exhibits a large λ-like peak at the ferrimagnetic ordering phase transition, a signature that is remarkably similar to La(Fe,Si)13, where it is attributed to giant spin fluctuations. Using calorimetric measurements, we also determine the point at which the phase transition ceases to be first order: the critical magnetic field, μ0Hcrit = 0.4 ± 0.1 T and temperature Tcrit = 138.5 ± 0.5 K, and we compare these values to those obtained from analysis of magnetization by application of the Shimizu inequality for itinerant electron metamagnetism. Good agreement is found between these independent measurements, thus establishing the phase diagram and critical point with some confidence. In addition, we find that the often-used Banerjee criterion may not be suitable for determination of first order behavior in itinerant magnet systems.

  16. Calorimetric system and method

    DOEpatents

    Gschneidner, Jr., Karl A.; Pecharsky, Vitalij K.; Moorman, Jack O.

    1998-09-15

    Apparatus for measuring heat capacity of a sample where a series of measurements are taken in succession comprises a sample holder in which a sample to be measured is disposed, a temperature sensor and sample heater for providing a heat pulse thermally connected to the sample, and an adiabatic heat shield in which the sample holder is positioned and including an electrical heater. An electrical power supply device provides an electrical power output to the sample heater to generate a heat pulse. The electrical power from a power source to the heat shield heater is adjusted by a control device, if necessary, from one measurement to the next in response to a sample temperature-versus-time change determined before and after a previous heat pulse to provide a subsequent sample temperature-versus-time change that is substantially linear before and after the subsequent heat pulse. A temperature sensor is used and operable over a range of temperatures ranging from approximately 3K to 350K depending upon the refrigerant used. The sample optionally can be subjected to dc magnetic fields such as from 0 to 12 Tesla (0 to 120 kOe).

  17. Calorimetric system and method

    DOEpatents

    Gschneidner, K.A. Jr.; Pecharsky, V.K.; Moorman, J.O.

    1998-09-15

    Apparatus is described for measuring heat capacity of a sample where a series of measurements are taken in succession comprises a sample holder in which a sample to be measured is disposed, a temperature sensor and sample heater for providing a heat pulse thermally connected to the sample, and an adiabatic heat shield in which the sample holder is positioned and including an electrical heater. An electrical power supply device provides an electrical power output to the sample heater to generate a heat pulse. The electrical power from a power source to the heat shield heater is adjusted by a control device, if necessary, from one measurement to the next in response to a sample temperature-versus-time change determined before and after a previous heat pulse to provide a subsequent sample temperature-versus-time change that is substantially linear before and after the subsequent heat pulse. A temperature sensor is used and operable over a range of temperatures ranging from approximately 3K to 350K depending upon the refrigerant used. The sample optionally can be subjected to dc magnetic fields such as from 0 to 12 Tesla (0 to 120 kOe). 18 figs.

  18. Micromechanical calorimetric sensor

    DOEpatents

    Thundat, Thomas G.; Doktycz, Mitchel J.

    2000-01-01

    A calorimeter sensor apparatus is developed utilizing microcantilevered spring elements for detecting thermal changes within a sample containing biomolecules which undergo chemical and biochemical reactions. The spring element includes a bimaterial layer of chemicals on a coated region on at least one surface of the microcantilever. The chemicals generate a differential thermal stress across the surface upon reaction of the chemicals with an analyte or biomolecules within the sample due to the heat of chemical reactions in the sample placed on the coated region. The thermal stress across the spring element surface creates mechanical bending of the microcantilever. The spring element has a low thermal mass to allow detection and measuring of heat transfers associated with chemical and biochemical reactions within a sample placed on or near the coated region. A second surface may have a different material, or the second surface and body of microcantilever may be of an inert composition. The differential thermal stress between the surfaces of the microcantilever create bending of the cantilever. Deflections of the cantilever are detected by a variety of detection techniques. The microcantilever may be approximately 1 to 200 .mu.m long, approximately 1 to 50 .mu.m wide, and approximately 0.3 to 3.0 .mu.m thick. A sensitivity for detection of deflections is in the range of 0.01 nanometers. The microcantilever is extremely sensitive to thermal changes in samples as small as 30 microliters.

  19. How to simplify the CT diagnosis of Le Fort fractures.

    PubMed

    Rhea, James T; Novelline, Robert A

    2005-05-01

    The numerous components seen in the Le Fort fractures make classification difficult. Our objective is to simplify the task of classifying Le Fort fractures. Each of the Le Fort fractures has at least one unique component that is easily recognizable: I, the anterolateral margin of the nasal fossa; II, the inferior orbital rim; and III, the zygomatic arch. Classification of the Le Fort fractures is simplified by using these unique components to establish a tentative classification that is then confirmed.

  20. Le syndrome d’alcoolisme foetal

    PubMed Central

    2002-01-01

    L’alcool est un tératogène physique et comportemental. Le syndrome d’alcoolisme foetal (SAF) est un trouble courant mais encore sous-diagnostiqué découlant de la consommation d’alcool par la mère pendant la grossesse. Bien qu’il puisse être prévenu, le SAF est également invalidant. Même si le SAF est présent dans tous les groupes socioéconomiques du Canada, sa prévalence est élevée dans certaines communautés inuites et des Premières nations du Canada. Le présent énoncé porte sur la prévention, le diagnostic, le dépistage précoce et la prise en charge du SAF par les professionnels de la santé. La prévention du SAF doit s’effectuer à deux échelons. La prévention primaire consiste à éliminer le SAF par une formation en classe ou dans la collectivité et à inciter les femmes à éviter de consommer de l’alcool avant la conception et pendant la grossesse. La prévention secondaire consiste à repérer les femmes qui boivent pendant leur grossesse et à réduire leur consommation. Le présent énoncé décrit plusieurs stratégies de dépistage, dont la stratégie T-ACE (tolérance-agacement, réduction, éveil). Les dispensateurs de soins devraient recommander l’abstinence dès la première visite prénatale. Un envoi rapide en consultation en vue de traiter l’alcoolisme est recommandé pour les femmes enceintes incapables d’arrêter de boire. Le présent énoncé décrit le diagnostic de SAF, de SAF partiel ou atypique, d’anomalies congénitales et de troubles neurodéveloppementaux reliés à l’alcool. En cas d’exposition à l’alcool in utero, un diagnostic de SAF devrait être envisagé en présence d’un retard de croissance courant ou antérieur, de certaines anomalies faciales touchant la lèvre supérieure et les yeux et d’anomalies neurodéveloppementales. Ces caractéristiques sont mieux quantifiées au moyen d’une méthode diagnostique à quatre chiffres. Des stratégies de dépistage précoce des

  1. Le matérialisme scientifique

    NASA Astrophysics Data System (ADS)

    Meunier, Jean-François

    2004-03-01

    De nos jours, il arrive quotidiennement aux grands hommes d'avoir à fréquenter d'ignorants mortels épris d'une conviction maladive que la science est la grande responsable de tous les maux du monde. Évidemment sans physique atomique, il n'y aurait pas eu d'Hiroshima et sans révolution industrielle, pas de pollution et etc. Cependant, ces accusations envers le progrès technique sont tout à fait injustes, irréfléchies et, j'irai même jusqu'à dire, irresponsables, puisque le calcul, i.e. la planification, même la plus élémentaire, est ce qui caractérise le mieux, pragmatiquement, la société humaine. À mon avis, les problèmes sociaux tireraient plutôt leur origine de sciences sociales irréalistes, qui, concrètment, inspireraient ou serviraient d'alibis à ceux qui détiennent véritablement le pouvoir. Dans cet article, je tenterai donc de démontrer la meilleure véracité et efficacité du matérialisme scientifique. Cette doctrine, dont Mario Bunge est le plus illustre représentant, s'appuy sur les résultats théoriques et expérimentaux des sciences factuelles ainsi que sur l'exactitude logique des mathématiques, utilisées ici comme langage universel de l'expression des idées. Cette conception philosophique qui s'inspire principalement du modèle des théories physiques, stipule que les réalités sociales sont, comme tout autre réalité, matérielles, mathématisables et représentables comme des systèmes en interaction. En fait, le modèle des physiciens ayant historiquement fait ses preuves en matière de testabilité et de cohérence interne est proposé d'être appliquer aux sciences sociales, aujourd'hui scindées des sciences dites pures sous l'inspiration des pseudo penseurs néo-kantiens, phénoménologiques et post-moderne. Cette nouvelle approche permettrait ainsi d'évoluer plus exactement vers une compréhension des bases sociales et biologiques du comportement humain afin de développer une éthique sans cesse plus r

  2. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2003-09-01

    Système solaire poussiéreux; Combien d'étoiles dans le ciel?; Distance d'un pulsar; Planètes poussières et métaux; Un amateur belge bat les professionnels; Matière sombre; Supernova asymétrique; Anneau liégeois; Amas globulaires; Amas globulaires vagabonds; Baptême de satellites; Champ de gravité terrestre; Début de l'univers; XMM et Geminga; Carte neutrinos du ciel; Galaxies et trous noirs; Univers X; SMART-1: signal de départ pour l'aventure lunaire; Les saisons de Pluton; Planète dans M4; Rotation des pulsars; Un jumeau de Jupiter?; Le satellite ISO; Mars Express~:dernier clin d'oeil à la Terre; Waterworld: une réalité?

  3. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2013-06-01

    Une binaire remarquable; Collision de galaxies; La nébuleuse planétaire C1295; ALMA (suite); Couple massif; Astéroïdes lointains; L’eau de Jupiter; Occultation par Pluton; Super-Terres; Première image d’une planète massive autour d’une étoile double; Tempête au pôle de Saturne

  4. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2002-06-01

    Loi tchèque sur la pollution lumineuse; XTE J0929-314; Futurs amas de galaxies; Palomar 5; La météo des naines brunes; Trous noirs et galaxies elliptiques; Europe; 2MASS; Mars; Io; Matière sombre; Un objet très froid; Les oscillations stellaires; Un système lanétaire en formation; Binaire serrée; Satellites de Jupiter; Mars sous la loupe; Le Hubble nouveau

  5. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2003-01-01

    Premier plongeon d'Integral dans l'univers du rayonnement gamma; Collisions et cannibalisme galactique; Proplydes dans la Carène; Quasar record; Eta Carinae étoile double; Géantes rouges; La vitesse de la gravité; Sursaut gamma; Une planète lointaine; Un Troyen neptunien; L'univers lointain; Bébé galaxie; Le centre de notre Galaxie version X; Un HERO astronomique; Disque X géant; Electrons mystérieux dans RCW 38; Environnement martien; Interférométrie infrarouge; Méthane titanien; Micro-organismes atmosphériques; Réchauffement planétaire; La meilleure observation infrarouge de l'univers; Planètes en grand nombre?; Pôle sud et Big Bang; SS 433; Volcans et astéroïdes; Amalthée; De l'eau sur Mars; DEM L 106; Gliese 876; La taille des étoiles; Le danger des supernovas; Vieux cailloux

  6. Les Troubles Respiratoires Chez Le Brule

    PubMed Central

    Fassi Fihri, J.; Ezzoubi, M.; Boukind, E.H.

    2010-01-01

    Summary A travers une revue de la littérature, cet article se propose d'exposer les particularités des troubles respiratoires chez le brûlé. Ces troubles sont liés à un mécanisme direct, lorsque l'arbre respiratoire est lésé par le transfert d'énergie thermique du à la brûlure et/ou par un mécanisme indirect, lorsque la fonction respiratoire et ventilatoire du poumon est perturbée par les phénomènes loco-régionaux ou généraux du brûlé. Ces troubles respiratoires sont aggravés par l'inhalation des gaz contenus dans la fumée d'incendie. Le diagnostic de ces troubles est clinique et paraclinique. Il doit être précoce et continu. Les patients nécessitent de différents moyens thérapeutiques tels que l'oxygénothérapie, la libération des voies respiratoires, l'amélioration de la mécanique ventilatoire et de la fonction respiratoire, l'antibiothérapie ou la chirurgie des séquelles. Cette prise en charge doit nécessairement être multidisciplinaire. PMID:21991224

  7. Search for low-mass weakly interacting massive particles using voltage-assisted calorimetric ionization detection in the SuperCDMS experiment.

    PubMed

    Agnese, R; Anderson, A J; Asai, M; Balakishiyeva, D; Basu Thakur, R; Bauer, D A; Billard, J; Borgland, A; Bowles, M A; Brandt, D; Brink, P L; Bunker, R; Cabrera, B; Caldwell, D O; Cerdeno, D G; Chagani, H; Cooley, J; Cornell, B; Crewdson, C H; Cushman, P; Daal, M; Di Stefano, P C F; Doughty, T; Esteban, L; Fallows, S; Figueroa-Feliciano, E; Godfrey, G L; Golwala, S R; Hall, J; Harris, H R; Hertel, S A; Hofer, T; Holmgren, D; Hsu, L; Huber, M E; Jastram, A; Kamaev, O; Kara, B; Kelsey, M H; Kennedy, A; Kiveni, M; Koch, K; Loer, B; Lopez Asamar, E; Mahapatra, R; Mandic, V; Martinez, C; McCarthy, K A; Mirabolfathi, N; Moffatt, R A; Moore, D C; Nadeau, P; Nelson, R H; Page, K; Partridge, R; Pepin, M; Phipps, A; Prasad, K; Pyle, M; Qiu, H; Rau, W; Redl, P; Reisetter, A; Ricci, Y; Saab, T; Sadoulet, B; Sander, J; Schneck, K; Schnee, R W; Scorza, S; Serfass, B; Shank, B; Speller, D; Villano, A N; Welliver, B; Wright, D H; Yellin, S; Yen, J J; Young, B A; Zhang, J

    2014-01-31

    SuperCDMS is an experiment designed to directly detect weakly interacting massive particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this Letter, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage-assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for ten live days at the Soudan Underground Laboratory. A low energy threshold of 170  eVee (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6  GeV/c2.

  8. Development of a new type of high pressure calorimetric cell, mechanically agitated and equipped with a dynamic pressure control system: application to the characterization of gas hydrates.

    PubMed

    Plantier, F; Marlin, L; Missima, D; Torré, J-P

    2013-12-01

    A novel prototype of calorimetric cell has been developed allowing experiments under pressure with an in situ agitation system and a dynamic control of the pressure inside the cell. The use of such a system opens a wide range of potential practical applications for determining properties of complex fluids in both pressurized and agitated conditions. The technical details of this prototype and its calibration procedure are described, and an application devoted to the determination of phase equilibrium and phase change enthalpy of gas hydrates is presented. Our results, obtained with a good precision and reproducibility, were found in fairly good agreement with those found in literature, illustrate the various interests to use this novel apparatus.

  9. Calorimetric measurements of the light-induced metastable high-spin state on the [Fe(PM-BiA) 2(NCS) 2] complex

    NASA Astrophysics Data System (ADS)

    Rodríguez-Velamazán, J. A.; Castro, M.; Palacios, E.; Burriel, R.; Sánchez Costa, J.; Létard, J. F.

    2007-02-01

    Heat capacity measurements have been obtained on a pellet sample of [Fe(PM-BiA) 2(NCS) 2] formed by applying uniaxial pressure on the powder compound. They show a broad heat capacity peak near 170 K corresponding to a thermal spin crossover transition with enthalpy and entropy values around 4 kJ mol -1 and 24 J mol -1 K -1, respectively, and a hysteresis of a few kelvins. Magnetic data of the pellet sample show a gradual and incomplete thermal transition. Light irradiation ( λ = 750-850 nm) at 5 K promotes the high-spin (HS) state and photomagnetic measurements give T(LIESST) = 68 ± 1 K. The heat capacity of this excited state has been measured and the relaxation from the HS to the LS state has been followed with AC calorimetry. An extended anomaly is observed centred at 66.5 K. This is the first calorimetric report of a sample on a LIESST state.

  10. Search for Low-Mass Weakly Interacting Massive Particles Using Voltage-Assisted Calorimetric Ionization Detection in the SuperCDMS Experiment

    SciTech Connect

    Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Bowles, M. A.; Brandt, D.; Brink, P. L.; Bunker, R.; Cabrera, B.; Caldwell, D. O.; Cerdeno, D. G.; Chagani, H.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, P.; Daal, M.; Di Stefano, P. C. F.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, J.; Harris, H. R.; Hertel, S. A.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Kiveni, M.; Koch, K.; Loer, B.; Lopez Asamar, E.; Mahapatra, R.; Mandic, V.; Martinez, C.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Moore, D. C.; Nadeau, P.; Nelson, R. H.; Page, K.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redl, P.; Reisetter, A.; Ricci, Y.; Saab, T.; Sadoulet, B.; Sander, J.; Schneck, K.; Schnee, R. W.; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Villano, A. N.; Welliver, B.; Wright, D. H.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.

    2014-01-01

    SuperCDMS is an experiment designed to directly detect Weakly Interacting Massive Particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this paper, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage- assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for 10 live days at the Soudan Underground Laboratory. A low energy threshold of 170 eVee (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6 GeV/c2.

  11. Determination of the Temperature Change by Means of an Outcoming Signal of Electric Resistance in an Isoperibolic Calorimetric Cell. Obtainment of Heat Solution

    PubMed Central

    Giraldo-Gutierréz, Liliana; Moreno-Piraján, Juan Carlos

    2005-01-01

    An isoperibolic calorimetric cell is built with glass surrounded by plastic insulation. The cell has a lid on which a thermistor thermometer, an electric resistance to provide the cell with definite quantities of electric work and a container for a glass ampoule, are placed. For measuring the thermal changes, an NTC thermistor, which provides an electric resistance signal that varies with temperature, is used. Calibration curves of the thermistor and of the stabilization of the system signal in thermal equilibrium are shown, which enable the observation of a good insulation. The calorific capacity of the system with water, with a value of 206.7 ±0.7 J °C-1 is determined; the solution enthalpy for propanol-water and KCl-water systems is obtained, which shows the behavior of the cell before exothermic and endothermic effects, respectively.

  12. A Search for Low-Mass Weakly Interacting Massive Particles Using Voltage-Assisted Calorimetric Ionization Detection in the SuperCDMS Experiment

    SciTech Connect

    Agnese, R.; Anderson, A. J.; Asai, M.; Balakishiyeva, D.; Basu Thakur, R.; Bauer, D. A.; Billard, J.; Borgland, A.; Bowles, M. A.; Brandt, D.; Brink, P. L.; Bunker, R.; Cabrera, B.; Caldwell, D. O.; Cerdeno, D. G.; Chagani, H.; Cooley, J.; Cornell, B.; Crewdson, C. H.; Cushman, Priscilla B.; Daal, M.; Di Stefano, P. C.; Doughty, T.; Esteban, L.; Fallows, S.; Figueroa-Feliciano, E.; Godfrey, G. L.; Golwala, S. R.; Hall, Jeter C.; Harris, H. R.; Hertel, S. A.; Hofer, T.; Holmgren, D.; Hsu, L.; Huber, M. E.; Jastram, A.; Kamaev, O.; Kara, B.; Kelsey, M. H.; Kennedy, A.; Kiveni, M.; Koch, K.; Loer, B.; Lopez Asamar, E.; Mahapatra, R.; Mandic, V.; Martinez, C.; McCarthy, K. A.; Mirabolfathi, N.; Moffatt, R. A.; Moore, D. C.; Nadeau, P.; Nelson, R. H.; Page, K.; Partridge, R.; Pepin, M.; Phipps, A.; Prasad, K.; Pyle, M.; Qiu, H.; Rau, W.; Redi, P.; Reisetter, A.; Ricci, Y.; Saab, T.; Sadoulet, B.; Sander, J.; Schneck, K.; Schnee, Richard; Scorza, S.; Serfass, B.; Shank, B.; Speller, D.; Villano, A. N.; Welliver, B.; Wright, D. H.; Yellin, S.; Yen, J. J.; Young, B. A.; Zhang, J.

    2014-01-27

    SuperCDMS is an experiment designed to directly detect weakly interacting massive particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this Letter, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage-assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for ten live days at the Soudan Underground Laboratory. A low energy threshold of (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6 GeV/c2.

  13. Magnetic and calorimetric investigations of inverse magnetocaloric effect in Pr0.46Sr0.54MnO3

    NASA Astrophysics Data System (ADS)

    Naik, V. B.; Barik, S. K.; Mahendiran, R.; Raveau, B.

    2011-03-01

    We investigated magnetic entropy change (ΔSm) in the A-type antiferromagnet Pr0.46Sr0.54MnO3 by magnetic and differential scanning calorimetry (DSC) methods. The field-induced antiferromagnetic to ferromagnetic transition is first-order in nature and is accompanied by a large change in the latent heat as evidenced by the DSC data. The ΔSm shows an inverse magnetocaloric effect (ΔSm=+9 J kg-1 K-1 for ΔH =7 T) around the Neel temperature (TN=210±2 K) by magnetic measurement, which closely agrees with the calorimetric results. It is suggested that the large positive ΔSm results from a field-induced structural transition that accompanies the destruction of antiferromagnetism.

  14. Calorimetric determination of the magnetic phase diagram of underdoped ortho II YBa2Cu3O6.54 single crystals

    PubMed Central

    Marcenat, C.; Demuer, A.; Beauvois, K.; Michon, B.; Grockowiak, A.; Liang, R.; Hardy, W.; Bonn, D. A.; Klein, T.

    2015-01-01

    The recent discovery of a charge order in underdoped YBa2Cu3Oy raised the question of the interplay between superconductivity and this competing phase. Understanding the normal state of high-temperature superconductors is now an essential step towards the description of the pairing mechanism in those materials and determining the upper critical field is therefore of fundamental importance. We present here a calorimetric determination of the field–temperature phase diagram in underdoped YBa2Cu3Oy single crystals. We show that the specific heat saturates in high magnetic fields. This saturation is consistent with a normal state without any significant superconducting contribution and a total Sommerfeld coefficient γN∼6.5±1.5 mJ mol−1 K−2 putting strong constraints on the theoretical models for the Fermi surface reconstruction. PMID:26294047

  15. Development of a new type of high pressure calorimetric cell, mechanically agitated and equipped with a dynamic pressure control system: Application to the characterization of gas hydrates

    SciTech Connect

    Plantier, F. Missima, D.; Torré, J.-P.; Marlin, L.

    2013-12-15

    A novel prototype of calorimetric cell has been developed allowing experiments under pressure with an in situ agitation system and a dynamic control of the pressure inside the cell. The use of such a system opens a wide range of potential practical applications for determining properties of complex fluids in both pressurized and agitated conditions. The technical details of this prototype and its calibration procedure are described, and an application devoted to the determination of phase equilibrium and phase change enthalpy of gas hydrates is presented. Our results, obtained with a good precision and reproducibility, were found in fairly good agreement with those found in literature, illustrate the various interests to use this novel apparatus.

  16. Spectroscopic and calorimetric studies of formation of the supramolecular complexes of PAMAM G5-NH₂ and G5-OH dendrimers with 5-fluorouracil in aqueous solution.

    PubMed

    Buczkowski, Adam; Olesinski, Tomasz; Zbicinska, Elzbieta; Urbaniak, Pawel; Palecz, Bartlomiej

    2015-07-25

    The results of spectroscopic measurements (increase in solubility, equilibrium dialysis, (1)H NMR titration) and calorimetric measurements (isothermal titration ITC) indicate exothermic (ΔH<0) and spontaneous (ΔG < 0) combination of an antitumor drug, 5-fluorouracil, by both cationic PAMAM G5-NH2 dendrimer and its hydroxyl analog PAMAM G5-OH in aqueous solutions at room temperature. PAMAM G5-NH2 dendrimer combines about 70 molecules of the drug with equilibrium constant K ≅ 300, which is accompanied by an increase in the system order (ΔS < 0). Hydroxyl dendrimer, PAMAM G5-OH, combines about 14 molecules of 5-fluorouracil with equilibrium constant K ≅ 100. This process is accompanied by an increase in the system disorder (ΔS > 0). Copyright © 2015 Elsevier B.V. All rights reserved.

  17. The calorimetric-respirometric ratio is an on-line marker of enthalpy efficiency of yeast cells growing on a non-fermentable carbon source.

    PubMed

    Dejean, L; Beauvoit, B; Bunoust, O; Fleury, C; Guérin, B; Rigoulet, M

    2001-01-19

    Although on-line calorimetry has been widely used to detect transitions in global metabolic activity during the growth of microorganisms, the relationships between oxygen consumption flux and heat production are poorly documented. In this work, we developed a respirometric and calorimetric approach to determine the enthalpy efficiency of respiration-linked energy transformation of isolated yeast mitochondria and yeast cells under growing and resting conditions. On isolated mitochondria, the analysis of different phosphorylating and non-phosphorylating steady states clearly showed that the simultaneous measurements of heat production and oxygen consumption rates can lead to the determination of both the enthalpy efficiency and the ATP/O yield of oxidative phosphorylation. However, these determinations were made possible only when the net enthalpy change associated with the phosphorylating system was different from zero. On whole yeast cells, it is shown that the simultaneous steady state measurements of the heat production and oxygen consumption rates allow the enthalpy growth efficiency (i.e. the amount of energy conserved as biomass compared to the energy utilised for complete catabolism plus anabolism) to be assessed. This method is based on the comparison between the calorimetric-respirometric ratio (CR ratio) determined under growth versus resting conditions during a purely aerobic metabolism. Therefore, in contrast to the enthalpy balance approach, this method does not rely on the exhaustive and tedious determinations of the metabolites and elemental composition of biomass. Thus, experiments can be performed in the presence of non-limiting amounts of carbon substrate, an approach which has been successfully applied to slow growing cells such as yeast cells expressing wild-type or a mutant rat uncoupling protein-1.

  18. 1,1,1,3,3,3-hexafluoroisopropanol induced thermal unfolding and molten globule state of bovine alpha-lactalbumin: calorimetric and spectroscopic studies.

    PubMed

    Kundu, Agnita; Kishore, Nand

    2004-03-01

    The thermal denaturation of alpha-lactalbumin was studied at pH 7.0 and 9.0 in aqueous 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) by high-sensitivity differential scanning calorimetry. The conformation of the protein was analyzed by a combination of fluorescence and circular dichroism measurements. The most obvious effect of HFIP was lowering of the transition temperature with an increase in the concentration of the alcohol up to 0.30M, beyond which no calorimetric transition was observed. Up to 0.30M HFIP the calorimetric and van't Hoff enthalpy remained the same, indicating the validity of the two-state approximation for the thermal unfolding of alpha-lactalbumin. The quantitative thermodynamic parameters accompanying the thermal transitions have been evaluated. Spectroscopic observations confirm that alpha-lactalbumin is in the molten globule state in the presence of 0.50M HFIP at pH 7.0 and 0.75M HFIP at pH 9.0. The results also demonstrate that alpha-lactalbumin in the molten globule state undergoes a noncooperative thermal transition to the denatured state. It is observed that two of four tryptophans are exposed to the solvent in the HFIP induced molten globule state of alpha-lactalbumin compared to four in the 8.5M urea induced denatured state of the protein. It is also observed that the HFIP induced molten globule states at the two pH values are different from the acid induced molten globule state (A state) of alpha-lactalbumin. Copyright 2004 Wiley Periodicals, Inc.

  19. Le déficit immunitaire humoral: mieux le connaître pour mieux le prendre en charge

    PubMed Central

    El Bakkouri, Jalila; Aadam, Zahra; Ailal, Fatima; Alj, Hanane Salih; Bousfiha, Ahmed Aziz

    2014-01-01

    Les déficits immunitaires humoraux (DIH) sont des maladies hétérogènes allant des formes asymptomatiques rencontrés lors des déficits sélectifs en immunoglobulines A (IgA) et en sous-classes d'IgG aux formes graves des agammaglobulinémies congénitales. Les patients atteints de DIH présentent souvent des infections ORL ou des voies respiratoires récidivantes ou sévères. Ces patients peuvent présenter un certain nombre de complications non infectieuses, telles que des manifestations auto-immunes et des entéropathies, qui pourraient être le seul symptôme clinique révélateur. Les formes sévères des DIH sont facilement diagnostiquées grâce au dosage des IgG totaux, des IgA et des IgM. La thérapie substitutive par les immunoglobulines reste le traitement de choix chez ces patients. PMID:25489366

  20. Le Chatelier's principle with multiple relaxation channels

    NASA Astrophysics Data System (ADS)

    Gilmore, R.; Levine, R. D.

    1986-05-01

    Le Chatelier's principle is discussed within the constrained variational approach to thermodynamics. The formulation is general enough to encompass systems not in thermal (or chemical) equilibrium. Particular attention is given to systems with multiple constraints which can be relaxed. The moderation of the initial perturbation increases as additional constraints are removed. This result is studied in particular when the (coupled) relaxation channels have widely different time scales. A series of inequalities is derived which describes the successive moderation as each successive relaxation channel opens up. These inequalities are interpreted within the metric-geometry representation of thermodynamics.

  1. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2014-04-01

    Cartographie d’une naine brune; 2006DP14; Anatomie d’un astéroïde; L’astéroïde P/2013 R3; Formation des planètes; Planètes Kepler; Bêta Pictoris; Cratère Mojave; Les astéroïdes de la ceinture principale; Planète X; Mercure et la gravitation; Gloire sur Vénus; Galaxies elliptiques massives; Cas A; SN 2014J et les supernovae Ia; Le Grand Nuage de Magellan; Nébuleuse d’Andromède; ESO 137-001

  2. Books reconsidered: Emile Durkheim, Le Suicide.

    PubMed

    Robertson, Michael

    2006-12-01

    To reappraise Emile Durkheim's taxonomy of suicide in Le Suicide in the light of recent experience. While Durkheim's scientific method and argument are fundamentally flawed, some of his concepts have instrumental value in attempting to understand the complex origins of suicidal behaviour. Durkheim's baseless dismissal of mental illness as a key determinant of suicidal behaviour weakens his thesis significantly. However, his conceptualization of anomic, egoistic and altruistic suicide provides a means of comprehending recent trends in suicidal behaviour in the former Soviet states and a possible window into the psyche of the suicides of religious and political extremists.

  3. Le synovialosarcome primitif de la verge

    PubMed Central

    Saadi, Ahmed; Bouzouita, Abderrazak; Kerkeni, Walid; Ayed, Haroun; Znaidi, Nadia Sabbegh; Ben Miled, Aicha; Messai, Taha; Cherif, Mohamed; Ben Slama, Riadh; Rammeh, Soumaya; Mnif, Najla; Maalej, Mongi; Derouiche, Amine; Chebil, Mohamed

    2017-01-01

    Résumé Le synovialosarcome représente un sous-type rare des sarcomes des tissus mous. Son apparition au niveau de la verge est exceptionnelle et seulement deux cas ont été rapportés dans la littérature auparavant. Nous rapportons un nouveau cas de synovialosarcome de la verge chez un jeune patient de 27 ans, en essayant par l’entremise d’une revue de la littérature de discuter des aspects radiologiques, histologiques, immunohistochimiques, thérapeutiques et pronostiques de cette tumeur exceptionnelle. PMID:28163814

  4. Lele de l’omalizumab dans le traitement de l’asthme allergique grave

    PubMed Central

    Chapman, Kenneth R; Cartier, André; Hébert, Jacques; McIvor, R Andrew; Schellenberg, R Robert

    2006-01-01

    CONTEXTE : Un nouveau traitement anti-immunoglobuline E (anti-IgE) contre l’asthme, l’omalizumab, a été approuvé au Canada. OBJECTIF : Passer en revue les données fondamentales et cliniques sur l’omalizumab et examiner lele possible de ce médicament dans la prise en charge de l’asthme au Canada. MÉTHODOLOGIE : Une recherche documentaire a été effectuée dans MEDLINE afin de repérer les études menées de 1960 à 2006 sur l’omalizumab. La recherche a également porté sur les résumés de réunions scientifiques récentes dans le domaine des maladies respiratoires et des allergies; par ailleurs, toute donnée non publiée a été demandée au fabricant. Après avoir revu et résumé les données, un comité mixte constitué de spécialistes des maladies respiratoires et des allergies a rédigé un ensemble de recommandations relatives à l’utilisation de l’omalizumab. RÉSULTATS : L’omalizumab est un anticorps monoclonal humanisé qui se lie au domaine C epsilon 3 de la molécule d’IgE pour former des complexes immuns solubles qui sont éliminés par le système réticulo-endothélial. L’administration d’injections sous-cutanées espacées de deux ou de quatre semaines à la dose recommandée entraîne une diminution rapide des taux d’IgE circulantes libres. Lors de deux essais cliniques de phase III menés auprès de 1 405 adultes et adolescents atteints d’asthme modéré à grave qui recevaient des doses moyennes stables de corticostéroïdes en inhalation (CSI), l’omalizumab a diminué les taux d’exacerbation par rapport au placebo et a été associé à une amélioration des symptômes ainsi qu’à une épargne plus importante des corticostéroïdes. Dans un essai mené auprès de 419 patients atteints d’asthme grave non maîtrisé malgré l’utilisation de doses élevées de CSI et de la prise concomitante d’agonistes bêta-2 à action prolongée, les exacerbations graves étaient de 50 % moins fréquentes chez

  5. Insights: Simple Models for Teaching Equilibrium and Le Chatelier's Principle.

    ERIC Educational Resources Information Center

    Russell, Joan M.

    1988-01-01

    Presents three models that have been effective for teaching chemical equilibrium and Le Chatelier's principle: (1) the liquid transfer model, (2) the fish model, and (3) the teeter-totter model. Explains each model and its relation to Le Chatelier's principle. (MVL)

  6. Insights: Simple Models for Teaching Equilibrium and Le Chatelier's Principle.

    ERIC Educational Resources Information Center

    Russell, Joan M.

    1988-01-01

    Presents three models that have been effective for teaching chemical equilibrium and Le Chatelier's principle: (1) the liquid transfer model, (2) the fish model, and (3) the teeter-totter model. Explains each model and its relation to Le Chatelier's principle. (MVL)

  7. Effects of LeY glycan expression on embryo implantation.

    PubMed

    Gu, J; Sui, L-L; Cui, D; Ma, Y-N; Zhu, C-Y; Kong, Y

    2016-08-01

    To investigate the correlation between LeY glycan expression and embryo implantation. Uterine epithelial cells before implantation were transfected with FUT1siRNA to inhibit FUT1 (the gene encoding the key enzyme of LeY synthesis) expression and treated with 10 ng/ml leukemia inhibitory factor (LIF). Murine embryo implantation model in vitro was prepared by late blastocysts with identical morphology and treated uterine epithelial cells co-culture. Using RT-PCR, dot blot and observation of embryo attachment to analyze FUT1 gene expression and LeY synthesis of uterine epithelial cells and studied further the correlation of LeY expression level and embryo implantation. FUT1 gene expression and LeY synthesis declined after cells were transfected with FUT1siRNA, and LIF promoted FUT1 expression and LeY synthesis. After expression of FUT1 gene was inhibited, attachment rate of embryos lowered, but LIF up-regulated FUT1 expression and increased the attachment rate of embryos. These results indicated regulating FUT1 expression affected LeY synthesis, and then LeY regulated the recognition and attachment of uterus-embryo and participates in embryo implantation further.

  8. Second Language Acquisition of the Chinese Particle "Le."

    ERIC Educational Resources Information Center

    Wen, Xiaohong

    1995-01-01

    This study investigated 14 English speakers' interlanguage constructions using the Chinese perfective aspect and the sentence-final modal particle. The results show that although the surface forms of the perfective aspect "-le" and the sentence-final "le" are identical, they are learned differently, with the perfective aspect…

  9. Calorimetric and spectroscopic studies of the thermotropic phase behavior of lipid bilayer model membranes composed of a homologous series of linear saturated phosphatidylserines.

    PubMed Central

    Lewis, R N; McElhaney, R N

    2000-01-01

    The thermotropic phase behavior of lipid bilayer model membranes composed of the even-numbered, N-saturated 1,2-diacyl phosphatidylserines was studied by differential scanning calorimetry and by Fourier-transform infrared and (31)P-nuclear magnetic resonance spectroscopy. At pH 7.0, 0.1 M NaCl and in the absence of divalent cations, aqueous dispersions of these lipids, which have not been incubated at low temperature, exhibit a single calorimetrically detectable phase transition that is fully reversible, highly cooperative, and relatively energetic, and the transition temperatures and enthalpies increase progressively with increases in hydrocarbon chain length. Our spectroscopic observations confirm that this thermal event is a lamellar gel (L(beta))-to-lamellar liquid crystalline (L(alpha)) phase transition. However, after low temperature incubation, the L(beta)/L(alpha) phase transition of dilauroyl phosphatidylserine is replaced by a higher temperature, more enthalpic, and less cooperative phase transition, and an additional lower temperature, less enthalpic, and less cooperative phase transition appears in the longer chain phosphatidylserines. Our spectroscopic results indicate that this change in thermotropic phase behavior when incubated at low temperatures results from the conversion of the L(beta) phase to a highly ordered lamellar crystalline (L(c)) phase. Upon heating, the L(c) phase of dilauroyl phosphatidylserine converts directly to the L(alpha) phase at a temperature slightly higher than that of its original L(beta)/L(alpha) phase transition. Calorimetrically, this process is manifested by a less cooperative but considerably more energetic, higher-temperature phase transition, which replaces the weaker L(beta)/L(alpha) phase transition alluded to above. However, with the longer chain compounds, the L(c) phase first converts to the L(beta) phase at temperatures some 10-25 degrees C below that at which the L(beta) phase converts to the L(alpha) phase

  10. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2006-11-01

    Glace et éclairs; Astéroïdes; Pluton; Avatars et avanie d'une petite planète (Xena, Eris); Nuage d'éthane sur Titan; Lacs de Titan; La NASA scrute Mars; Les express Mars et Venus; Cydonia, le visage sur Mars; Transit d'Ariel; Lune; Gonflée, la planète; Terres, terres!; Une planète extrasolaire aurait abrité de l'eau liquide; Des planètes au centre de la Voie Lactée; Anatomie d'un disque protoplanétaire; CHRX73 et pseudo-planète; Systèmes étranges; Premières galaxies; Voie Lactée; Neutrinos; RCW 86

  11. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2009-10-01

    Dunes de Titan; Lac Ontario; Titan; Anneaux de Saturne; Jupiter; Mars; Rotation de Saturne; Valles Marineris; Méthane martien; Epsilon Aurigae; Glycine cométaire; HD 87643; Pluton; Bételgeuse; Site astronomique; Andromède cannibale; Attaque de trou noir; BD+44 493; Formation d'étoiles; Gaz manquant; LIGO; M87; Naine blanche; Galaxie satellite; Galaxies naines sphéroïdales; Galaxies trapues; Cygnus X-1; L'avenir de la Voie Lactée; Naphtaline cosmique; Premiers trous noirs; Coup de foudre; Effet de serre; Glace lunaire; Impacts et extinctions; Exoplanètes rétrogrades; Kepler; Planète chaude; Collision planétaire; Disques dans le vent; Exoplanètes; Formation des planètes; Taches et transits

  12. Le contrôle des infections au cabinet du pédiatre

    PubMed Central

    2008-01-01

    RÉSUMÉ La transmission des infections au cabinet du pédiatre est de plus en plus préoccupante. Le présent document expose les voies de transmission des infections et les principes sous-jacents aux mesures actuelles pour contrôler les infections. Pour prévenir les infections, il faut bien concevoir le cabinet et adopter des politiques administratives et de triage convenables, de même que des pratiques de base pour les soins de tous les patients (p. ex., hygiène des mains, port de gants, de masques, de lunettes de protection et d’une blouse d’hôpital pour des interventions précises; nettoyage, désinfection et stérilisation convenables des surfaces et du matériel, y compris les jouets, et techniques d’asepsie en cas d’interventions effractives) et des précautions additionnelles en cas d’infections précises. Le personnel doit avoir reçu les vaccins pertinents, et les personnes infectées doivent respecter les politiques de restriction au travail.

  13. A chip-calorimetric approach to the analysis of Ag nanoparticle caused inhibition and inactivation of beads-grown bacterial biofilms.

    PubMed

    Hartmann, Tom; Mühling, Martin; Wolf, Antje; Mariana, Frida; Maskow, Thomas; Mertens, Florian; Neu, Thomas R; Lerchner, Johannes

    2013-11-01

    With the increasing complexity of model systems for the investigation of antibacterial effects of nanoparticles, the demands on appropriate analysis methods are rising. In case of biofilms grown on small particles, the high inhomogeneity of the samples represents a major challenge for traditional biofilm analysis. For this purpose, we developed a new calorimetric method which allows non-invasive and real-time investigation of the effects of nanoparticles on beads-grown biofilms which meets the requirements for an increased sample throughput. The method employs a newly developed chip calorimeter that is able to detect changes in the metabolic activity of biofilm samples within minutes. Using this novel device, the antibacterial effect of silver nanoparticles on Pseudomonas putida biofilms grown on agarose beads was investigated. The superparamagnetic properties of the embedded particles within the agarose beads allow an automated sample throughput. Growth inhibition and inactivation effects of silver nanoparticles (AgNPs) on biofilm bacteria were quantified by analyzing the metabolic heat production rate. As a result, a concentration dependent manner of growth inhibition and inactivation was found demonstrating the suitability and sensitivity of the methodology.

  14. Notable Stabilization of α-Chymotrypsin by the Protic Ionic Additive, [ch][dhp]: Calorimetric Evidence for a Fine Enthalpy/Entropy Balance

    PubMed Central

    Makharadze, Maya; van Eldik, Rudi; Khoshtariya, Dimitri E.

    2014-01-01

    An impact of 0.5 to 3 M choline dihydrogen phosphate, [ch][dhp], the biotechnologically relevant ionic substance, on the thermal stability of a model globular protein, α-chymotrypsin (α-CT), has been studied exploiting the highly sensitive differential scanning calorimetry (DSC) technique. The notable overall stabilizing effect of 11 ± 2 K regarding the thermal transition (melting) temperature, Tm, has been detected. For this kind of series, for the first time, the calorimetric melting enthalpy (ΔHcal) and transition entropy (ΔSm) parameters have been determined simultaneously throughout. The first analysis indicated a two-phase impact implying (a) the initial, dramatic drop in both ΔHcal and ΔSm, obviously connected to specific, direct interaction between the [ch][dhp] components and α-CT's charged groups (within 0 to 1 mol/L [ch][dhp]), leading to the essential rearrangement of the interfacial hydrogen-bonded (HB) network; and (b) the follow-up (within 1 to 3.0 mol/L [ch][dhp]), modest changes in ΔHcal and lack of changes in ΔSm, seemingly connected with a subsequent steady strengthening of already reformed HB network, respectively. These changes, presumably, are primarily facilitated by Coulombic interactions between the [dhp] anions and solvent-exposed positively charged amino groups of α-CT. PMID:27437474

  15. Thioglycolic acid grafted onto silica gel and its properties in relation to extracting cations from ethanolic solution determined by calorimetric technique.

    PubMed

    Arakaki, Luiza N H; Espínola, José G P; da Fonseca, Maria G; de Oliveira, Severino F; de Sousa, Antonio N; Arakaki, Tomaz; Airoldi, Claudio

    2004-05-01

    Thioglycolic acid was immobilized onto silica gel surface using 3-aminopropyltrimethoxysilane as precursor silylating agent to yield silica. The amount of thioglycolic acid immobilized was 1.03 mmol per gram of silica. This new surface displayed a chelating moiety containing nitrogen, sulfur, and oxygen basic centers which are potentially capable of extracting cations from ethanolic solution, such as MCl3 ( M=Fe, Cr, and Mo). This process of extraction was carried out by the batch method when similar chemisorption isotherms were observed for all cations. The data were adjusted to a modified Langmuir equation. The sequence of the maximum retention capacity was Cr(III) > Mo(III) > Fe(III). The same adsorption was determined by calorimetric titration and the enthalpic values of -35.75 +/- 0.02, 32.90 +/- 0.15, and -84.08 +/- 0.12 kJmol(-1) for chromium, molybdenum, and iron, respectively, were obtained. From the calculated Gibbs free energy -23.4 +/- 0.2, -27.2 +/- 0.2, and -32.7 +/- 0.3 kJmol(-1), the variations in entropy obtained were 42 +/- 1, 201 +/- 1, 172 +/- 1 JK(-1)mol(-1) for the same sequence. All thermodynamic values are in agreement with the spontaneity of the proposed cation-basic center interactions for these chelating processes.

  16. Evaluation of different calorimetric methods to determine the glass transition temperature and molecular mobility below T(g) for amorphous drugs.

    PubMed

    Weuts, I; Kempen, D; Six, K; Peeters, J; Verreck, G; Brewster, M; Van den Mooter, G

    2003-06-18

    The purpose of the present study was to compare different calorimetric methods used to determine the glass transition temperature (T(g)) and to evaluate the relaxation behaviour and hence the stability of amorphous drugs below their T(g). Data showed that the values of the activation energy for the transition of a glass to its super-cooled liquid state qualitatively correlate with the values of the mean molecular relaxation time constant of ketoconazole, itraconazole and miconazole, three structurally related drugs. Estimation of the molecular mobility by activation energy calculation indicated that loperamide was more stable than its two building blocks T263 and R731. It was further shown that the most commonly used approach to determine T(g) (T(g (1/2 c(p))) leads to erroneous values when enthalpy recovery is significant. In this case, an alternative method based on enthalpic considerations leads to results in accordance to basic thermodynamics. Estimation of molecular mobility based on activation energy calculations is therefore considered to be a valuable alternative for the method based on measurement of the extent of relaxation. When enthalpy relaxation is important, the use of T(g 1/2c(p)) leads to an overestimation of the T(g).

  17. Automated Verification of Design Patterns with LePUS3

    NASA Technical Reports Server (NTRS)

    Nicholson, Jonathan; Gasparis, Epameinondas; Eden, Ammon H.; Kazman, Rick

    2009-01-01

    Specification and [visual] modelling languages are expected to combine strong abstraction mechanisms with rigour, scalability, and parsimony. LePUS3 is a visual, object-oriented design description language axiomatized in a decidable subset of the first-order predicate logic. We demonstrate how LePUS3 is used to formally specify a structural design pattern and prove ( verify ) whether any JavaTM 1.4 program satisfies that specification. We also show how LePUS3 specifications (charts) are composed and how they are verified fully automatically in the Two-Tier Programming Toolkit.

  18. L’apport de la dermoscopie dans le carcinome basosquameux

    PubMed Central

    Elmahi, Hakima; Lahlou, Asmae; Baybay, Hanane; Gallouj, Salim; Mernissi, Fatima Zahra; Reggad, Fatima Zahra; Harmouch, Taoufik

    2016-01-01

    Le carcinome basosquameux (CBS) est un cancer cutané rare qui présente des zones de carcinome basocellulaire (CBC) et de carcinome épidermoïde (SCC) et une zone de transition entre elles. Cependant, les caractéristiques dermoscopiques du BSC ne sont pas bien décrites dans la littérature, sauf deux études. Le but du présent cas était de mieux identifier et clarifier la contribution de la dermoscopie dans le diagnostic du BSC, malgré que la confirmation reste toujours histologique. PMID:28293368

  19. Les Hemorragies Gastroduodenales de Stress Chez le Brule Grave

    PubMed Central

    Siah, S.; Fouadi, F.E.; Ababou, K.; Nassim Sabah, T.; Ihrai, I.

    2008-01-01

    Summary Les Auteurs rapportent trois observations d'hémorragies gastroduodénales de stress chez le brûlé grave. Ils rappellent l'importance des mesures thérapeutiques qui doivent être prises chez le brûlé grave, comme le traitement du choc, du sepsis, des plaies et de la douleur, la nutrition entérale précoce et l'oxygénothérapie. Tout cela permet de réduire les facteurs de risque de survenue d'une hémorragie gastroduodénale de stress. PMID:21991137

  20. Le point sur les amas de galaxies

    NASA Astrophysics Data System (ADS)

    Pierre, M.

    galaxies jouent donc un rôle de premier plan dans toute étude cosmologique et par conséquent, sont indispensables à notre compréhension globale de l'univers. Dans l'introduction générale, nous détaillons cet aspect fondamental en montrant comment l'étude des amas peut contribuer à contraindre les scénarios cosmologiques. Une fois le contexte scientifique délimité, les chapitres suivants s'attachent à présenter les diverses propriétés des amas et leur évolution cosmique observée dans diverses longueurs d'onde principalement dans les domaines visible (galaxies), X (gaz) et radio (gaz et particules). Nous verrons que l'étude détaillée d'un amas implique celle de l'interaction entre ses différentes composantes et est un passage obligé pour remonter au paramètre ultime (ou premier) qu'est sa masse. Loin d'être un détour ennuyeux, ceci sera l'occasion d'aborder des phénomènes physiques extrêmement variés tel l'aspect multi-phases du milieu intra-amas, les sursauts de formation d'étoiles et l'évolution morphologique des galaxies capturées par les amas, ou bien encore, l'interaction entre le plasma intra-amas et les particules relativistes accélérées lors de la fusion entre deux amas. Bien sûr, pour chaque longueur d'onde, nous ne manquerons pas de décrire simplement les techniques d'observation et d'analyse mises en oeuvre ; celles-ci sont particulièrement intéressantes dans le cas de l'instrumentation spatiale. Nous terminerons en présentant des projets d'observatoires pour l'horizon 2010 et leur impact prévu sur l'étude des amas de galaxies.

  1. L'astronomie dans le monde

    NASA Astrophysics Data System (ADS)

    Manfroid, J.

    2007-09-01

    Anions interstellaires; S Orionis; Altaîr; Courants stellaires; Etoiles jeunes; 2MASSW J1207334-393254; Alpha Andromède; Etoiles à neutrons (1); LH54-425; AGNs invisibles; Deux supernovae; Les GRBs seon Swift; Peser les trous noirs; Formation de trous noirs; Trou noir; ondes gravitationnelles : Virgo entre dans sa phase d'exploitation scientifique; Amas de galaxies actifs; Amas de galaxies; Galaxies actives d'amas; L'univers statique: le retour; Macho; Exoplanètes; Exoplanètes habitables?; Exoplanètes habitables? (suite); Une année d'un an; Une année de 31 heures; Valse des Jupiters; Disque de HD 15115; Impact majeur; Planètes isolées; Super-Jupiter; Impact et mini-extinction; L'effet Pioneer; Toungouska; Spéléo martienne; Autres lunes dactives; Encelade; Hypérion; Pluton dépassé; Satellites d'Uranus; Titan

  2. Lymphoscintigraphy (LS) in lymphedema (LE) of the extremities

    SciTech Connect

    Gloviczki, P.; Vaqueiro, M.; Fisher, J.; Schirger, A.; Dewanjee, M.K.; Hollier, L.H.; Wahner, H.W.

    1985-05-01

    Twenty-two patients with primary and secondary LE and one with lipedema had LS using 0.4-0.6 mCi of Tc-99mSb2Sb3 subcutaneous at the second interdigital space. Three had excisional surgery, in four patients lympho-venous anastomosis (LVA) was attempted following LS. Results are presented in this paper. This study concludes that LS is a noninvasive method without side effects that visualizes the pattern of the lymphatic system in LE. If lymph channels were seen, LVA could be performed. LS seems adequate for patient selection and follow-up after LVA. It differentiated LE from lipedema. Image patterns or quantitative studies could not differentiate between primary and secondary LE.

  3. Microscopic Description of Le Châtelier's Principle

    NASA Astrophysics Data System (ADS)

    Novak, Igor

    2005-08-01

    The analysis based on microscopic descriptors (energy levels and their populations) is given that provides visualization of free energies and conceptual rationalization of Le Châtelier's principle. The misconception "nature favors equilibrium" is highlighted.

  4. LePaProGen—lepton pair production generator

    NASA Astrophysics Data System (ADS)

    Dydyshka, Ya. V.; Yermolchyk, V. L.; Suarez, J. H.; Shumeiko, N. M.

    2017-09-01

    A Monte Carlo generator "LePaProGen" for simulation of lepton pair production at hadron colliders is presented. Higher order electroweak radiative effects are implemented. A new algorithm for selection of the optimal phase space parameterization is applied.

  5. Some Aspects of the Teaching of "-Guo" and "-Le"

    ERIC Educational Resources Information Center

    Ma, Jing-heng S.

    1977-01-01

    This paper examines the two markers of Mandarin Chinese, "-guo" and "-le," and focuses primarily on areas of difficulty that the non-native speaker may encounter due to confusion of these markers. (CHK)

  6. CIM - A Manufacturing Paradigm (Le CIM - Un Nouveau Modele Industriel),

    DTIC Science & Technology

    1986-07-01

    fait la plupart des entreprises , ont affind le module de "Rgvolution industrielle". Nous vivons A l’poque du spdcialiste. Toutefois, le modale de sp...program will serve as an umbrella under which specific projects are planned, financed , managed, and imple- mented. Well defined corporate goals must be...assets. Through an integration of financing strategies an enterprise can focus on capital investment in shared, value-added assets such as databases

  7. Study of the influence of heat sources on the out-of-pile calibration curve of calorimetric cells used for nuclear energy deposition quantification

    SciTech Connect

    De Vita, C.; Brun, J.; Reynard-Carette, C.; Carette, M.; Amharrak, H.; Lyoussi, A.; Fourmentel, D.; Villard, J.F.

    2015-07-01

    calorimeter cell head. This discrepancy is higher than in previous experiments because the calorimeter owns a high sensitivity. Consequently, a new prototype was created and instrumented by other heat sources in order to impose an energy deposition on the calorimetric cell structure (in particular in the base) and to improve the calibration step in out-of-pile conditions. In this paper, on the first part a detailed description of the new calorimetric sensor will be given. On the second part, the experimental response of the sensor obtained for several internal heating conditions will be shown. The influence of these conditions on the calibration curve will be discussed. Then the response of this prototype will be also presented for different external cooling fluid conditions (in particular flow temperature). In this part, the comparison between the in-pile and out-of-pile experimental results will be performed. On the last part, these out-of-pile experiments will be completed by 2D axisymmetrical thermal simulations with the CEA code CAST3M using Finite Elements Method. After a comparison between experimental and numerical works, improvements of the sensor prototype will be studied (new heat sources). (authors)

  8. Le Soleil et ses relations avec la Terre

    NASA Astrophysics Data System (ADS)

    Lang, Kenneth; Heidmann, M.

    C'est le 2e livre de K. Lang publié en français, considéré comme texte complementaire au célèbre Vagabonds de l'Espace qui avait gagné en 1994 le prix du livre d'astronomie en France. Maintenant l'auteur se concentre sur le système le plus élémentaire: l'étoile et son planète, et choisit celui qui est le plus intéressant pour nous: le Soleil et la Terre. Il a accumulé les observations terrestres et les plus récentes effectuées par des observatoires spatiales, et ceux des météorologues et géophysiciens, et nous présente un panorama fascinant du Soleil et ses relations avec la Terre. C'est la physique qui a les conséquences les plus fondamentales aux événements qui influencent notre environment, notre vie et même la condition humaine y inclu les arts et la litérature.

  9. Transmaxillary Sinus Approach for Le Fort II Osteotomy

    PubMed Central

    Fukawa, Toshihiko; Hirakawa, Takashi; Satake, Toshihiko; Maegawa, Jiro

    2016-01-01

    Summary: The Le Fort II osteotomy is a relatively rare operation. The posterior wall osteotomy of the maxillary sinus (MS) is often difficult for Le Fort III. We developed the transmaxillary sinus approach (TSA) for the Le Fort II osteotomy that cuts the posterior wall of the MS directly. This report illustrates this easy-to-use procedure for the Le Fort II osteotomy in syndromic craniosynostosis. This procedure was performed in an 18-year-old patient with Apert syndrome and a 15-year-old patient with Pfeiffer syndrome. The thin anterior walls of the MS were removed through an intraoral approach to look inside the MS. Then, the posterior walls were cut by chisel under direct vision using light. The other osteotomy was performed as usual. Distraction osteogenesis with internal and external devices was used in combination. The advantages of TSA are the direct posterior wall osteotomy of the MS with no down fracture and minimal invasiveness to the mucosa of the MS under direct vision. However, the disadvantage is that TSA becomes a blind procedure in a case with no MS or hypoplasia. We developed the TSA for the Le Fort II osteotomy, which could provide direct observation and perform the posterior wall osteotomy of the MS without down fracture. We believe that TSA is an effective surgical procedure for the Le Fort II osteotomy. PMID:27014548

  10. Searching the animal psyche with Charles Le Brun.

    PubMed

    Cohen, Sarah R

    2010-07-01

    Around 1670 the French court painter and Academician Charles Le Brun produced a series of drawings featuring naturalistic animal heads, as well as imaginary heads in which he refashioned various nonhuman animal species to make humanoid physiognomies. What were the purpose and significance of these unusual works? I argue that they show Le Brun's interest in what we today would call animal psychology: focusing upon the sensory organs and their connections with the animal's brain, Le Brun studied his animals as conscious protagonists of the natural realm. One source that may have served him in this project was Marin Cureau de La Chambre's De la Connoissance des bestes of 1645, in which the physician argued that animals possess a conscious soul grounded in the senses. However, Le Brun's animal-humans have no clear place in the artist's taxonomy--nor, indeed, in any seventeenth-century understandings of species. It is rather John Locke, at his most skeptical, who offers the best parallel in the realm of natural philosophy to Le Brun's unsettling animal-humans. Probably without meaning to, Le Brun demonstrated through his eerie, boundary-crossing creatures the limits of visual classification.

  11. Calorimetric measurements of fusion enthalpies for Ni 2SiO 4 and Co 2SiO 4 olivines and application to olivine-liquid partitioning

    NASA Astrophysics Data System (ADS)

    Sugawara, Toru; Akaogi, Masaki

    2003-07-01

    Calorimetric measurements of fusion enthalpies for Ni 2SiO 4 and Co 2SiO 4 olivines were carried out using a high-temperature calorimeter, and Ni and Co partitioning between olivine and silicate liquid was analyzed using the measured heats of fusion. The fusion enthalpy of Co 2SiO 4 olivine measured by transposed-temperature drop calorimetry was 103 ± 15 kJ/mol at melting point (1688 K). The fusion enthalpy of Ni 2SiO 4 olivine was calculated based on the enthalpies of liquids in the system An 50Di 50-Ni 2SiO 4 measured by transposed-temperature drop calorimetry at 1773 K, and was 221 ± 26 kJ/mol at its metastable melting point (1923 K). The fusion enthalpy of Ni 2SiO 4 is the largest among those of olivine group, this is caused by the large crystal field stabilization energy of six-coordinated Ni 2+ in olivine. The larger fusion enthalpy of Ni 2SiO 4 can account for the large and variable partition coefficient of Ni between olivine and silicate liquid. Based on the comparison between partition coefficients calculated from thermodynamic data and those observed in partition experiments, it is considered that the magnitude of partition coefficients is primarily dependent on the heats of fusion of the components. Furthermore, the activity coefficients for Ni-, Co- and Mn-bearing components in magmatic liquid are nearly of the same magnitude.

  12. In vitro activity of gallium maltolate against Staphylococci in logarithmic, stationary, and biofilm growth phases: comparison of conventional and calorimetric susceptibility testing methods.

    PubMed

    Baldoni, Daniela; Steinhuber, Andrea; Zimmerli, Werner; Trampuz, Andrej

    2010-01-01

    Ga(3+) is a semimetal element that competes for the iron-binding sites of transporters and enzymes. We investigated the activity of gallium maltolate (GaM), an organic gallium salt with high solubility, against laboratory and clinical strains of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-susceptible Staphylococcus epidermidis (MSSE), and methicillin-resistant S. epidermidis (MRSE) in logarithmic or stationary phase and in biofilms. The MICs of GaM were higher for S. aureus (375 to 2000 microg/ml) than S. epidermidis (94 to 200 microg/ml). Minimal biofilm inhibitory concentrations were 3,000 to >or=6,000 microg/ml (S. aureus) and 94 to 3,000 microg/ml (S. epidermidis). In time-kill studies, GaM exhibited a slow and dose-dependent killing, with maximal action at 24 h against S. aureus of 1.9 log(10) CFU/ml (MSSA) and 3.3 log(10) CFU/ml (MRSA) at 3x MIC and 2.9 log(10) CFU/ml (MSSE) and 4.0 log(10) CFU/ml (MRSE) against S. epidermidis at 10x MIC. In calorimetric studies, growth-related heat production was inhibited by GaM at subinhibitory concentrations; and the minimal heat inhibition concentrations were 188 to 4,500 microg/ml (MSSA), 94 to 1,500 microg/ml (MRSA), and 94 to 375 microg/ml (MSSE and MRSE), which correlated well with the MICs. Thus, calorimetry was a fast, accurate, and simple method useful for investigation of antimicrobial activity at subinhibitory concentrations. In conclusion, GaM exhibited activity against staphylococci in different growth phases, including in stationary phase and biofilms, but high concentrations were required. These data support the potential topical use of GaM, including its use for the treatment of wound infections, MRSA decolonization, and coating of implants.

  13. Le Point sur la Pharmacologie des Agents Anesthesiques Chez le Brule Grave

    PubMed Central

    Siah, S.; Ababou, K.; Benziane, H.; El Jaoudi; Bensghir, M.; Bakali, H.; El Wali, A.; Ihrai, I.; Drissi, N.K.

    2008-01-01

    Summary La pharmacologie des agents anesthésiques chez le brûlé est variable et imprévisible. Dans les premières 48 h, il y a une hypovolémie avec chute du débit cardiaque et des fuites plasmatiques. Après 48 h, il y a une hypervolémie avec augmentation du débit cardiaque, hypermétabolisme et la clearance des médicaments est augmentée. Parmi les facteurs de déséquilibre, on retrouve les variations des protéines plasmatiques. Deux protéines sont importantes chez le brûlé grave : l'albumine et l'alpha 1- glycoprotéine. Leur taux varie beaucoup au cours de l'évolution de la brûlure. Les agents anesthésiques dont la liaison avec ces deux protéines est prédominante verront leur pharmacocinétique modifiée. L'anesthésiste-réanimateur du service des brûlés va maîtriser ces notions pharmacologiques pour utiliser à bon escient les agents anesthésiques. PMID:21991108

  14. Etude de la transition tribologique entre le fretting et le meso-fretting pour des materiaux de contact electrique

    NASA Astrophysics Data System (ADS)

    Gagnon, Daniel

    Dans les installations electriques, les contacts sont toujours soumis a des contraintes alternees ou a des micro-deplacements. Il en resulte une corrosion par fretting, phenomene defini comme un type de deterioration de la surface qui se produit lorsque deux materiaux en contact sont soumis a des mouvements microscopiques d'oscillations de tres faible amplitude (0 a 100 mum). Ceci a pour effet de provoquer une degradation de la resistance de contact et une interruption du passage du courant. Ce phenomene a des repercussions considerables sur le plan pratique puisque les micro-deplacements de pieces en contact peuvent etre causes par la dilatation thermique differentielle des metaux, par des vibrations mecaniques, par la relaxation des contraintes ou par l'echauffement des contacts lorsqu'on interrompt et retablit le courant. Nous avons donc dans le cadre de cette these etudie plusieurs aspects du fretting (0--100 mum) et du meso-fretting (100 a 1000 mum) pour differents materiaux de contact electrique. Des travaux experimentaux ont ete realises a partir de deux montages reproduisant divers aspects de la degradation par le fretting. Un premier montage de fretting de type bille-plaque a ete entierement developpe a l'ETS et un second montage, de type fil-plaque a ete utilise en collaboration avec Hydro Quebec IREQ a Varennes. Plusieurs techniques de mesures et d'analyse relevant tant du domaine de la mecanique du contact que de la metallurgie ont ete utilisees pour traiter les resultats. L'influence du courant sur le taux d'usure et la force de friction a ete examinee pour divers materiaux de contacts. Des essais de fatigue thermique et electrique ont ete realises sur divers materiaux et lubrifiants de contact. Il a ete demontre que pour le domaine entre 100 mum et 1000 mum, le taux d'usure n'est pas le meme de 0 a 100 mum et au dela de 1000 mum. La plupart des materiaux evalues montrent un stade de comportement intermediaire dont le debut se situe entre 100 mum et

  15. Synthesis of a BSA-Le(x) glycoconjugate and recognition of Le(x) analogues by the anti-Le(x) monoclonal antibody SH1: the identification of a non-cross reactive analogue.

    PubMed

    Wang, Jo-Wen; Asnani, Ari; Auzanneau, France-Isabelle

    2010-10-15

    A Le(x) trisaccharide functionalized with a cysteamine arm was prepared and this synthesis provided additional information on the reactivity of N-acetylglucosamine O-4 acceptors when they are glycosylated with trichloroacetimidate donors activated with excess BF(3)·OEt(2). In turn, this trisaccharide was conjugated to BSA lysine side chains through a squarate-mediated coupling. This BSA-Le(x) glycoconjugate displayed 35 Le(x) haptens per BSA molecule. The relative affinity of the anti-Le(x) monoclonal antibody SH1 for the Le(x) antigen and analogues of Le(x) in which the D-glucosamine, L-fucose or D-galactose residues were replaced with D-glucose, L-rhamnose and D-glucose, respectively, was measured by competitive ELISA experiments. While all analogues were weaker inhibitors than the Le(x) antigen, only the analogue of Le(x) in which the galactose residue was replaced by a glucose unit showed no binding to the SH1 mAb. To confirm that the reduced or loss of recognition of the Le(x) analogues by the anti-Le(x) mAb SH1 did not result from different conformations adopted by the analogues when compared to the native Le(x) antigen, we assessed the conformational behavior of all trisaccharides by a combination of stochastic searches and NMR experiments. Our results showed that, indeed, the analogues adopted the same stacked conformation as that identified for the Le(x) antigen. The identification of a trisaccharide analogue that does not cross-react with Le(x) but still retains the same conformation as Le(x) constitutes the first step to the design of a safe anti-cancer vaccine based on the dimeric Le(x) tumor associated carbohydrate antigen.

  16. Transitions de phase dans le oxyde de yttrium vanadium

    NASA Astrophysics Data System (ADS)

    Roberge, Benoit

    Dans le mémoire qui suit, les ordres structural, magnétiques et orbital dans le YVO3 sont étudiés avec l'aide de la diffraction des rayons X,de la spectroscopie Raman et de la technique de la cavité résonnante hyperfréquence. L'objectif premier consiste à observer l'évolution de ces ordres en fonction de la température. Le mémoire met ensuite en évidence le couplage entre les différents ordres cohabitants dans le YVO3 . Les mesures effectuées par la diffraction des rayons X permettent de mesurer le caractère polycrystallin des échantillons du YVO 3. Une comparaison de nos mesures avec des mesures de diffraction des rayons X faites sur la poudre de YVO3 indique la faible présence de maclage. Les mesures effectuées avec la technique de résonnance hyperfréquence permettent de suivre l'évolution de la constante diélectrique en fonction de la température. Les changements impliquant l'ordre orbital se manifestent de manière évidente dans la constante diélectrique à 200 K et à 77 K. La transition diélectrique détectée à 77 K est une transition de premier ordre. Un couplage entre les propriétés diélectriques et magnétiques est observable à la température de Néel à 114 K. L'effet d'un champ magnétique fixe sur la température de transition de l'ordre orbital survenant à 77 K est également remarquable. Cela indique un couplage magnétodiélectrique démontrant ainsi le caractère multiferroïque du YVO 3. Finalement, l'observation d'un mécanisme de relaxation pouvant être modélisé par le modèle d'Havriliak-Negami est observé en dessous de 77 K. En utilisant le modèle d'Arrhénius et le modèle d'Havriliak-Negami, on peut caractériser le mécanisme avec son énergie d'activation et son temps de relaxation. Les mesures effectuées en spectroscopie Raman permettent de suivre l'évolution de la structure du YVO3 en fonction de la température. Les deux changements structuraux survenant à 200 K et 77 K sont observés. Le

  17. Inhomogeneites dans le Vent des Etoiles Wolf-Rayet

    NASA Astrophysics Data System (ADS)

    Robert, Carmelle

    1992-01-01

    Des mesures spectroscopiques effectuees avec un haut rapport signal sur bruit et une bonne resolution ont demontre l'existence de regions perturbees en mouvement dans le vent d'etoiles Wolf-Rayet (WR). L'echantillon d'objets etudies ici comprend 9 etoiles WR couvrant differents sous-types WN et WC. De nombreuses petites structures variables superposees au profil des raies d'emission formees dans le vent stellaire signalent la presence des perturbations. L'etude des variations globales des raies et l'examen des micro-structures individuelles ont permis de decrire plusieurs caracteristiques des perturbations. Entre autres, on observe des correlations significatives entre le niveau de variabilite des raies et certains parametres des etoiles qui confirment que le phenomene de variabilite est intrinseque au vent stellaire. En comparant les changements des vitesses radiales et des largeurs equivalentes des differentes raies d'une meme etoile, on conclut que les regions perturbees ont une etendue finie par rapport a l'enveloppe des etoiles. On peut facilement suivre les structures individuelles sur une periode de temps couvrant ~eq8 heures (et peut etre meme 24 heures) avant qu'elles ne disparaissent. Durant ce temps les structures se deplacent en s'eloignant du centre de la raie. A partir des differents comportements notes lors de l'analyse des variations globales et lors de l'examen des structures individuelles, on propose de representer les perturbations par un modele d'inhomogeneites discretes en expansion dans le vent. On suppose simplement que les inhomogeneites emettent comme le vent global (et absorbent aussi si le vent global montre un profil P Cyg). La superposition du graphique de l'acceleration radiale moyenne des inhomogeneites de WR140 en fonction de leur vitesse radiale et du modele theorique d'inhomogeneites qui suivent la loi generale de vitesse donne un taux d'acceleration lent, avec beta >= 3 pour les inhomogeneites de cette etoile. On obtient, entre

  18. Etude du Photochromisme et de la Photorefractivite dans le Poly

    NASA Astrophysics Data System (ADS)

    Ghailane, Fatima

    1995-11-01

    Nous avons etudie la possibilite d'utiliser un materiau organique, le poly(vinylcarbazole) comme milieu de stockage optique de masse en temps reel. Ce materiau dope aux photochromes presente un potentiel non negligeable pour l'holographie de volume en temps reel. Plusiers cycles, Ecriture-Lecture-Effacement, ont ete enregistres dans cette matrice polymerique avec une resolution assez elevee. Une etude a ete menee afin d'obtenir la valeur des parametres comme l'epaisseur du film et l'intensite d'ecriture pour un angle d'enregistrement theta_{ acute ecriture} donne qui permettent d'obtenir les meilleures efficacites diffractionelles tout en preservant ce milieu de tout effet de fatigue ou de degradation. Ce polymere devient photorefractif une fois melange avec un bon accepteur de charge, le trinitrofluorenone et un bon chromophore non-lineaire, le disperse orange 25. Nous avons etudie experimentalement la conductivite en obscurite et la photoconductivite de ce materiau. Des simulations numeriques ont ete realisees en se basant sur le modele de Poole-Frenkel. Nous avons aussi etudie l'implantation de faisceaux d'ions d'oxygene d'energie 200 keV pour inscrire dans le PVCz un guide d'onde plan a profil d'indice. Une etude ESCA complete cette partie afin de savoir les modifications induites par implementation ionique a l'interieur du film polymerique.

  19. Complete Thermodynamic Characterization of the Multiple Protonation Equilibria of the Aminoglycoside Antibiotic Paromomycin: A Calorimetric and Natural Abundance 15N NMR Study

    PubMed Central

    Barbieri, Christopher M.; Pilch, Daniel S.

    2006-01-01

    The binding of aminoglycoside antibiotics to a broad range of macromolecular targets is coupled to protonation of one or more of the amino groups that typify this class of drugs. Determining how and to what extent this linkage influences the energetics of the aminoglycoside-macromolecule binding reaction requires a detailed understanding of the thermodynamics associated with the protonation equilibria of the aminoglycoside amino groups. In recognition of this need, a calorimetric- and NMR-based approach for obtaining the requisite thermodynamic information is presented using paromomycin as the model aminoglycoside. Temperature- and pH-dependent 15N NMR studies provide pKa values for the five paromomycin amino groups, as well as the temperature dependence of these pKa values. These studies also indicate that the observed pKa values associated with the free base form of paromomycin are lower in magnitude than the corresponding values associated with the sulfate salt form of the drug. This difference in pKa is due to drug interactions with the sulfate counterions at the high drug concentrations (≥812 mM) used in the 15N NMR studies. Isothermal titration calorimetry studies conducted at drug concentrations ≤45 μM reveal that the extent of paromomycin protonation linked to the binding of the drug to its pharmacologically relevant target, the 16 S rRNA A-site, is consistent with the pKa values of the free base and not the sulfate salt form of the drug. Temperature- and pH-dependent isothermal titration calorimetry studies yield exothermic enthalpy changes (ΔH) for protonation of the five paromomycin amino groups, as well as positive heat capacity changes (ΔCp) for three of the five amino groups. Regarded as a whole, the results presented here represent an important first step toward establishing a thermodynamic database that can be used to predict how aminoglycoside-macromolecule binding energetics will be influenced by conditions such as temperature, pH, and

  20. In Vitro Activity of Gallium Maltolate against Staphylococci in Logarithmic, Stationary, and Biofilm Growth Phases: Comparison of Conventional and Calorimetric Susceptibility Testing Methods▿

    PubMed Central

    Baldoni, Daniela; Steinhuber, Andrea; Zimmerli, Werner; Trampuz, Andrej

    2010-01-01

    Ga3+ is a semimetal element that competes for the iron-binding sites of transporters and enzymes. We investigated the activity of gallium maltolate (GaM), an organic gallium salt with high solubility, against laboratory and clinical strains of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-susceptible Staphylococcus epidermidis (MSSE), and methicillin-resistant S. epidermidis (MRSE) in logarithmic or stationary phase and in biofilms. The MICs of GaM were higher for S. aureus (375 to 2000 μg/ml) than S. epidermidis (94 to 200 μg/ml). Minimal biofilm inhibitory concentrations were 3,000 to ≥6,000 μg/ml (S. aureus) and 94 to 3,000 μg/ml (S. epidermidis). In time-kill studies, GaM exhibited a slow and dose-dependent killing, with maximal action at 24 h against S. aureus of 1.9 log10 CFU/ml (MSSA) and 3.3 log10 CFU/ml (MRSA) at 3× MIC and 2.9 log10 CFU/ml (MSSE) and 4.0 log10 CFU/ml (MRSE) against S. epidermidis at 10× MIC. In calorimetric studies, growth-related heat production was inhibited by GaM at subinhibitory concentrations; and the minimal heat inhibition concentrations were 188 to 4,500 μg/ml (MSSA), 94 to 1,500 μg/ml (MRSA), and 94 to 375 μg/ml (MSSE and MRSE), which correlated well with the MICs. Thus, calorimetry was a fast, accurate, and simple method useful for investigation of antimicrobial activity at subinhibitory concentrations. In conclusion, GaM exhibited activity against staphylococci in different growth phases, including in stationary phase and biofilms, but high concentrations were required. These data support the potential topical use of GaM, including its use for the treatment of wound infections, MRSA decolonization, and coating of implants. PMID:19805560

  1. Le syndrome des enfants battus: aspects cliniques et radiologiques

    PubMed Central

    Jlalia, Zied; Znaigui, Talel; Smida, Mahmoud

    2016-01-01

    La maltraitance physique des enfants ou le syndrome des enfants battus est responsable de plus de 75.000 décès par an en France. Ce problème de santé publique reste sous diagnostiqué en Tunisie et dans le monde. Le chemin a été laborieux pour la reconnaissance du syndrome des enfants battus dans certaines sociétés même occidentales. Nous avons voulus exposer ce problème aux praticiens afin qu'il soit mieux diagnostiqué et pris en charge. La maltraitance physique des enfants est appelée à tort syndrome de Silverman qui ne regroupe en fait que les lésions squelettiques chez ces enfants tels que les fractures. Mots clés: Fracture, maltraitance, enfant, neuro-radiologie PMID:27642408

  2. Le Fort I Maxillary Advancement Using Distraction Osteogenesis

    PubMed Central

    Combs, Patrick D.; Harshbarger, Raymond J.

    2014-01-01

    Treatment of maxillary hypoplasia has traditionally involved conventional Le Fort I osteotomies and advancement. Advancements of greater than 10 mm risk significant relapse. This risk is greater in the cleft lip and palate population, whose anatomy and soft tissue scarring from prior procedures contributes to instability of conventional maxillary advancement. Le Fort I advancement with distraction osteogenesis has emerged as viable, stable treatment modality correction of severe maxillary hypoplasia in cleft, syndromic, and noncleft patients. In this article, the authors provide a review of current data and recommendations concerning Le Fort I advancement with distraction osteogenesis. In addition, they outline their technique for treating severe maxillary hypoplasia with distraction osteogenesis using internal devices. PMID:25383054

  3. Le zona ophtalmique: une dermatose rare chez l'enfant

    PubMed Central

    Zakia, Douhi; Meziane, Marieme; Salim, Gallouj; Zahra, Mernissi Fatima

    2015-01-01

    Le zona est dû a une réactivation du virus varicelle-zona (VZV) qui reste quiescent dans les ganglions sensitifs dorsaux après la varicelle. Le zona de l'enfant est rare et particulièrement la forme ophtalmique, qui peut être responsable de complications oculaires graves nécessitant une prise en charge adéquate et précoce. Il est parfois associé à des douleurs post-zostériennes dont le traitement est difficile. L'aciclovir per os administré dans les 72 heures après l’éruption a prouvé son efficacité dans la prévention des complications oculaires. Nous en rapportant un nouveaux cas chez un garçon immunocompétent de 9 ans, sans notion de varicelle antérieure. PMID:26955408

  4. Calorimetric study of cationic photopolymerization

    NASA Astrophysics Data System (ADS)

    Czajlik, I.; Hedvig, P.; Ille, A.; Dobó, J.

    1996-03-01

    The photopolymerization of penta-erythritol tetra-glycidyl ether (initiator Degacure KI-85) was studied by a du Pont 910 type DSC. From our experimental results the following conclusions can be drawn: (1) During the cationic polymerization reaction the lifetime of the initiating centers are long compared to the lifetime of free radicals in case of radical polymerization. (2) The rate of deactivation of the initiating centers increases with increasing temperature.

  5. Micro-machined calorimetric biosensors

    DOEpatents

    Doktycz, Mitchel J.; Britton, Jr., Charles L.; Smith, Stephen F.; Oden, Patrick I.; Bryan, William L.; Moore, James A.; Thundat, Thomas G.; Warmack, Robert J.

    2002-01-01

    A method and apparatus are provided for detecting and monitoring micro-volumetric enthalpic changes caused by molecular reactions. Micro-machining techniques are used to create very small thermally isolated masses incorporating temperature-sensitive circuitry. The thermally isolated masses are provided with a molecular layer or coating, and the temperature-sensitive circuitry provides an indication when the molecules of the coating are involved in an enthalpic reaction. The thermally isolated masses may be provided singly or in arrays and, in the latter case, the molecular coatings may differ to provide qualitative and/or quantitative assays of a substance.

  6. Calorimetric examination of hydrofracture grouts

    SciTech Connect

    Stinton, D.P.; Berger, R.L.

    1984-12-01

    A hydrofracture grout sample obtained during the SI-10 injection campaign was studied by calorimetry. The calorimetry curve of this grout was compared with laboratory-produced grout containing simulated wastes. Initiation of the cement-water reaction for the actual grout was delayed several days by the presence of a large quantity of boron in the waste. Although the hydration of cement was delayed, eventually the cement reacted with water and the grout hardened. This test indicates the potential need to analyze sludges for compounds known to retard cement hydration. 10 references, 5 figures, 4 tables.

  7. The receptor kinases LePRK1 and LePRK2 associate in pollen and when expressed in yeast, but dissociate in the presence of style extract

    PubMed Central

    Wengier, Diego; Valsecchi, Isabel; Cabanas, María Laura; Tang, Wei-hua; McCormick, Sheila; Muschietti, Jorge

    2003-01-01

    After pollen grains germinate on the stigma, pollen tubes traverse the extracellular matrix of the style on their way to the ovules. We previously characterized two pollen-specific, receptor-like kinases, LePRK1 and LePRK2, from tomato (Lycopersicon esculentum). Their structure and immunolocalization pattern and the specific dephosphorylation of LePRK2 suggested that these kinases might interact with signaling molecules in the style extracellular matrix. Here, we show that LePRK1 and LePRK2 can be coimmunoprecipitated from pollen or when expressed together in yeast. In yeast, their association requires LePRK2 kinase activity. In pollen, LePRK1 and LePRK2 are found in an ≈400-kDa protein complex that persists on pollen germination, but this complex is disrupted when pollen is germinated in vitro in the presence of style extract. In yeast, the addition of style extract also disrupts the interaction between LePRK1 and LePRK2. Fractionation of the style extract reveals that the disruption activity is enriched in the 3- to 10-kDa fraction. A component(s) in this fraction also is responsible for the specific dephosphorylation of LePRK2. The style component(s) that dephosphorylates LePRK2 is likely to be a heat-stable peptide that is present in exudate from the style. The generally accepted model of receptor kinase signaling involves binding of a ligand to extracellular domains of receptor kinases and subsequent activation of the signaling pathway by receptor autophosphorylation. In contrast to this typical scenario, we propose that a putative style ligand transduces the signal in pollen tubes by triggering the specific dephosphorylation of LePRK2, followed by dissociation of the LePRK complex. PMID:12748390

  8. Le Chatelier's Principle and the Prediction Temperature on Solubilities.

    ERIC Educational Resources Information Center

    Fernandez-Prini, R.

    1982-01-01

    Discusses Le Chatelier's Principle from a thermodynamic perspective and applies it to the effect of temperature on the solubility of gases in liquids. Rationale of this discussion is to evaluate data in a previous article claimed to be contradictory to the Principle. (Author/JN)

  9. Le Chatelier's Principle Applied to the Temperature Dependence of Solubility.

    ERIC Educational Resources Information Center

    Treptow, Richard S.

    1984-01-01

    One effect of temperature is its influence on solubility, and that effect is used as a common example when teaching Le Chatelier's principle. Attempts to clarify the question of whether the principle holds in the case of the solubility of ionic compounds in water by investigating the literature data in detail. (JN)

  10. Expectation of "Le Petit Prince"'s home

    NASA Astrophysics Data System (ADS)

    Abe, Masanao; Ohba, Yohei; Ishiguro, Masateru; Hasegawa, Sunao; Fuse, Tetsuharu

    2002-11-01

    We observed a few hundred meter-sized asteroid like "Le Petit Prince"'s home using Subaru telescope. The name of the asteroid is 1998 SF36, which is a target object of the Japanese asteroid sample return mission, MUSES-C. We report the results of the observations and expect the true picture of the tiny-sized asteroid.

  11. Le Dernier Cartoucherie: Refuge and the Performance of Care

    ERIC Educational Resources Information Center

    Fisek, Emine

    2008-01-01

    In 2003, the Paris-based theatre company Theatre du Soleil launched "Le Dernier Caravanserail: Odyssees", a collaborative creation based on stories that company members had collected from refugees at the Sangatte refugee camp outside Calais, among other locations. Scenes of moral reasoning dotted the six-hour spectacle, calling to mind…

  12. LHC, le Big Bang en éprouvette

    ScienceCinema

    None

    2016-07-12

    Notre compréhension de l’Univers est en train de changer… Bar des Sciences - Tout public Débat modéré par Marie-Odile Montchicourt, journaliste de France Info. Evenement en vidéoconférence entre le Globe de la science et de l’innovation, le bar le Baloard de Montpellier et la Maison des Métallos à Paris. Intervenants au CERN : Philippe Charpentier et Daniel Froideveaux, physiciens au CERN. Intervenants à Paris : Vincent Bontemps, philosophe et chercheur au CEA ; Jacques Arnould, philosophe, historien des sciences et théologien, Jean-Jacques Beineix, réalisateur, producteur, scénariste de cinéma. Intervenants à Montpellier (LPTA) : André Neveu, physicien théoricien et directeur de recherche au CNRS ; Gilbert Moultaka, physicien théoricien et chargé de recherche au CNRS. Partenariat : CERN, CEA, IN2P3, Université MPL2 (LPTA) Dans le cadre de la Fête de la science 2008

  13. Some special features of the le chatelier-braun principle

    NASA Astrophysics Data System (ADS)

    Nesis, E. I.; Skibin, Yu. N.

    2000-07-01

    The relaxation reaction of a system that follows from the Le Chatelier-Braun principle and weakens the result of an external influence turns out to be more intense under a complex action. A method for quantitative determination of the weakening effect for simple and complex actions is suggested.

  14. Le Chatelier's Principle and the Prediction Temperature on Solubilities.

    ERIC Educational Resources Information Center

    Fernandez-Prini, R.

    1982-01-01

    Discusses Le Chatelier's Principle from a thermodynamic perspective and applies it to the effect of temperature on the solubility of gases in liquids. Rationale of this discussion is to evaluate data in a previous article claimed to be contradictory to the Principle. (Author/JN)

  15. Ursula LeGuin's Magical World of Earthsea.

    ERIC Educational Resources Information Center

    Griffin, Jan M.

    1996-01-01

    Discusses how Ursula LeGuin's Earthsea Trilogy reflects her belief in Taoist philosophy as well as her skill in telling stories of magic and adventure. Notes that the three books can be described as coming-of-age novels in which three separate individuals struggle to become mature, responsible, whole adults. (RS)

  16. LePera Career Activity Program. Final Report.

    ERIC Educational Resources Information Center

    Truby, Max E.

    The purpose of the research project was to determine the effectiveness of a comprehensive career orientation program in increasing awareness of self and of career opportunities in students of rural areas. Conducted with grades 7 and 8 in LePera school in Parker, Arizona from May 1973 to October 1974, the program provided occupational information…

  17. Decolonizing the Choctaws: Teaching LeAnne Howe's "Shell Shaker"

    ERIC Educational Resources Information Center

    Hollrah, Patrice

    2004-01-01

    "Shell Shaker" (2001) by LeAnne Howe (Choctaw) is a novel that gives students an opportunity to learn that the history and culture of the Choctaw Nation of Oklahoma are alive today. Winner of the Before Columbus Foundation American Book Award in 2002, the novel deals with two parallel stories that converge in the present, one about the eighteenth…

  18. Errol Le Cain: The Very Best Aspects of Book Illustration.

    ERIC Educational Resources Information Center

    Eve, Matthew

    1999-01-01

    Examines Errol Le Cain's eclectic illustration contributions to children's literature throughout his life. Relates life experiences and influences to his work as an illustrator. Suggests that he constantly changed and adapted his style according to the prose, its tone, and the setting, unlike most other contemporary British book artists. (SC)

  19. MoLeNET Mobile Learning Conference 2009: Research Papers

    ERIC Educational Resources Information Center

    Guy Parker, Ed.

    2010-01-01

    The Mobile Learning Network (MoLeNET) is a unique collaborative approach to encouraging, supporting, expanding and promoting mobile learning, primarily in English post-14 education and training, via supported shared cost mobile learning projects. Collaboration at national level involves participating institutions and the Learning and Skills…

  20. Restorative Justice Scripts in Ursula K. Le Guin's "Voices"

    ERIC Educational Resources Information Center

    Oziewicz, Marek C.

    2011-01-01

    This essay examines restorative justice scripting in "Voices", the second volume of Ursula K. Le Guin's "Annals of the Western Shore." Narrated by a rape-child, "Voices" is the story of an occupied city-state and of how the conquered and the conquerors negotiate a formula for peaceful coexistence. They are able to do…

  1. Le Chatelier's Principle Applied to the Temperature Dependence of Solubility.

    ERIC Educational Resources Information Center

    Treptow, Richard S.

    1984-01-01

    One effect of temperature is its influence on solubility, and that effect is used as a common example when teaching Le Chatelier's principle. Attempts to clarify the question of whether the principle holds in the case of the solubility of ionic compounds in water by investigating the literature data in detail. (JN)

  2. Decolonizing the Choctaws: Teaching LeAnne Howe's "Shell Shaker"

    ERIC Educational Resources Information Center

    Hollrah, Patrice

    2004-01-01

    "Shell Shaker" (2001) by LeAnne Howe (Choctaw) is a novel that gives students an opportunity to learn that the history and culture of the Choctaw Nation of Oklahoma are alive today. Winner of the Before Columbus Foundation American Book Award in 2002, the novel deals with two parallel stories that converge in the present, one about the eighteenth…

  3. MoLeNET Mobile Learning Conference 2009: Research Papers

    ERIC Educational Resources Information Center

    Guy Parker, Ed.

    2010-01-01

    The Mobile Learning Network (MoLeNET) is a unique collaborative approach to encouraging, supporting, expanding and promoting mobile learning, primarily in English post-14 education and training, via supported shared cost mobile learning projects. Collaboration at national level involves participating institutions and the Learning and Skills…

  4. Computer Assisted Instruction: The Game "Le Choc des Multinationales."

    ERIC Educational Resources Information Center

    Cramer, Hazel

    "Le Choc de Multinationales" is a microcomputer game for students in an upper-level commercial French couse, to be played by two opponents, one of whom may be another student or the computer itself as a direct business competitor. The game's requirements for language use and knowledge of business and economics theory and principles are moderate,…

  5. The Discourse Function of the Verbal Suffix -Le in Mandarin.

    ERIC Educational Resources Information Center

    Chu, Chauncey C.; Chang, W. Vincent

    It is proposed that the functions of the Mandarin verbal suffix "-le" are three: (1) for marking non-continual factual actions or events; (2) for indicating the "peak" in an event line; and (3) for explicitly marking anteriority of an action or event. Observations of written language drawn from newspaper articles and…

  6. Les enfants et le theatre (Children and the Theater).

    ERIC Educational Resources Information Center

    Ferrari, Josephine

    1980-01-01

    Describes a project involving the presentation of "Le petit prince" as an exercise in dramatics by children in a French-Italian bilingual education class. Two steps in the process are discussed: (1) the study of the text, and (2) the activities involved in getting the play ready for performance. (AMH)

  7. Le Dernier Cartoucherie: Refuge and the Performance of Care

    ERIC Educational Resources Information Center

    Fisek, Emine

    2008-01-01

    In 2003, the Paris-based theatre company Theatre du Soleil launched "Le Dernier Caravanserail: Odyssees", a collaborative creation based on stories that company members had collected from refugees at the Sangatte refugee camp outside Calais, among other locations. Scenes of moral reasoning dotted the six-hour spectacle, calling to mind…

  8. LHC, le Big Bang en éprouvette

    SciTech Connect

    2010-04-07

    Notre compréhension de l’Univers est en train de changer… Bar des Sciences - Tout public Débat modéré par Marie-Odile Montchicourt, journaliste de France Info. Evenement en vidéoconférence entre le Globe de la science et de l’innovation, le bar le Baloard de Montpellier et la Maison des Métallos à Paris. Intervenants au CERN : Philippe Charpentier et Daniel Froideveaux, physiciens au CERN. Intervenants à Paris : Vincent Bontemps, philosophe et chercheur au CEA ; Jacques Arnould, philosophe, historien des sciences et théologien, Jean-Jacques Beineix, réalisateur, producteur, scénariste de cinéma. Intervenants à Montpellier (LPTA) : André Neveu, physicien théoricien et directeur de recherche au CNRS ; Gilbert Moultaka, physicien théoricien et chargé de recherche au CNRS. Partenariat : CERN, CEA, IN2P3, Université MPL2 (LPTA) Dans le cadre de la Fête de la science 2008

  9. LeRC in-house experimental research

    NASA Technical Reports Server (NTRS)

    Lyons, Valerie J.

    1992-01-01

    The topics covered include the following: LeRC in-house experimental research; combustion concepts; schedule for in-house experiments; lean premixed prevaporized combustion; comparisons of low NO(x) lean premixed/prevaporized data; rich burn/quick quench/lean burn (RQL); RQL combustion; fuel rich catalytic combustion; advanced diagnostics; and ceramic matrix liner test rig.

  10. Normal cellular prion protein is a ligand of selectins: binding requires LeX but is inhibited by sLeX

    PubMed Central

    Li, Chaoyang; Wong, Poki; Pan, Tao; Xiao, Fan; Yin, Shaoman; Chang, Binggong; Kang, Shin-Chung; Ironside, James; Sy, Man-Sun

    2007-01-01

    The normal PrPC (cellular prion protein) contains sLeX [sialyl-LeX (Lewis X)] and LeX. sLeX is a ligand of selectins. To examine whether PrPC is a ligand of selectins, we generated three human PrPC–Ig fusion proteins: one with LeX, one with sLeX, and the other with neither LeX nor sLeX. Only LeX-PrPC–Ig binds E-, L- and P-selectins. Binding is Ca2+-dependent and occurs with nanomolar affinity. Removal of sialic acid on sLeX-PrPC–Ig enables the fusion protein to bind all selectins. These findings were confirmed with brain-derived PrPC. The selectins precipitated PrPC in human brain in a Ca2+-dependent manner. Treatment of brain homogenates with neuraminidase increased the amounts of PrPC precipitated. Therefore the presence of sialic acid prevents the binding of PrPC in human brain to selectins. Hence, human brain PrPC interacts with selectins in a manner that is distinct from interactions in peripheral tissues. Alternations in these interactions may have pathological consequences. PMID:17497959

  11. Le syndrome d'embolie graisseuse post traumatique

    PubMed Central

    Berdai, Adnane Mohamed; Shimi, Abdelkarim; Khatouf, Mohammed

    2014-01-01

    Le syndrome d'embolie graisseuse est une complication grave des fractures des os longs, il est la conséquence de la dissémination des particules graisseuses dans la microcirculation. L'objectif de ce travail est de déterminer le profil épidémiologique, la présentation clinique et paraclinique de ce syndrome et sa prise en charge thérapeutique. Notre étude porte sur 11 cas de syndrome d'embolie graisseuse colligés au service de réanimation A1 au centre hospitalier universitaire Hassan II de Fès, de Janvier 2009 à Juin 2012. Le diagnostic positif est basé sur les critères de Gurd. Les cas collectés se caractérisent par la prédominance du sexe masculin, d'un âge inférieur à 40 ans, présentant une fracture fémorale. Ce syndrome survient souvent dans les 72 heures après le traumatisme. La présentation clinique est dominée par l'hypoxémie et les troubles de conscience. Sur le plan biologique: l'anémie et la thrombopénie sont les manifestations les plus fréquentes. La prise en charge est symptomatique, 63% des patients ont nécessité l'intubation et la ventilation. L’évolution n'est pas toujours bénigne. Nos résultats confirme le polymorphisme de la présentation clinique et paraclinique du syndrome d'embolie graisseuse. Le diagnostic de ce syndrome se base sur des critères cliniques, mais reste essentiellement un diagnostic d’élimination. La prise en charge est symptomatique. La prévention de ce syndrome est essentielle et se base sur une fixation précoce des fractures des os longs. PMID:25452829

  12. Simultaneous transgenic suppression of LePG and LeExp1 influences fruit texture and juice viscosity in a fresh market tomato variety.

    PubMed

    Powell, Ann L T; Kalamaki, Mary S; Kurien, Philip A; Gurrieri, Sergio; Bennett, Alan B

    2003-12-03

    Tomatoes are grown for fresh consumption or for processing of the fruit. Some ripening-associated processes of the fruit can either contribute to or degrade attributes associated with both fresh and processing quality. For example, cell wall disassembly is associated with loss of fresh fruit firmness as well as with loss of processed tomato product viscosity. Several enzymes contribute to cell wall polysaccharide disassembly. Polygalacturonase (PG, poly[1,4-alpha-d-galactouronide] glucanohydrolase, EC 3.2.1.15) is among the most abundant polysaccharide hydrolases in ripening tomato fruit and is the major contributor to pectin depolymerization. Expansin (LeExp1) is also abundant in ripening fruit and is proposed to contribute to cell wall disassembly by nonhydrolytic activity, possibly by increasing substrate accessibility to other enzymes. Suppression of either LePG or LeExp1 expression alone results in altered softening and/or shelf life characteristics. To test whether simultaneous suppression of both LePG and LeExp1 expression influences fruit texture in additive or synergistic ways, transgenic Lycopersicon esculentum var. Ailsa Craig lines with reduced expression of either LePG or LeExp1 were crossed. Fruits from the third generation of progeny, homozygous for both transgenic constructs, were analyzed for firmness and other quality traits during ripening on or off the vine. In field-grown transgenic tomato fruit, suppression of LeExp1 or LePG alone did not significantly increase fruit firmness. However, fruits suppressed for both LePG and LeExp1 expression were significantly firmer throughout ripening and were less susceptible to deterioration during long-term storage. Juice prepared from the transgenic tomato fruit with reduced LePG and LeExp1 expression was more viscous than juice prepared from control fruit.

  13. Effect of Cholesterol and Ergosterol on the Compressibility and Volume Fluctuations of Phospholipid-Sterol Bilayers in the Critical Point Region: A Molecular Acoustic and Calorimetric Study

    PubMed Central

    Krivanek, Roland; Okoro, Linus; Winter, Roland

    2008-01-01

    Although sterol-phospholipid interactions have been of interest for many years now, a complete thermodynamic profile of these systems is still missing. To contribute to a better understanding of the thermodynamic functions of these systems, we determined isothermal compressibility coefficient data for dipalmitoylphosphocholine (DPPC) and DPPC-containing cholesterol and ergosterol vesicles by means of molecular acoustics (ultrasound velocimetry and densimetry) and differential scanning and pressure perturbation calorimetric techniques. A particular focus was on the influence of the differential structural properties of the two sterols on the thermodynamic properties of lipid bilayers, and on the nature of the critical point region of phospholipid-sterol systems by determining thermodynamic fluctuation parameters. Contrary to significant changes in conformational and dynamical properties of the DPPC-sterol membranes, no marked differences were found in the various thermodynamic properties studied, including the adiabatic (\\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\beta}_{{\\mathrm{S}}}^{{\\mathrm{lipid}}}\\end{equation*}\\end{document}) and isothermal (\\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\beta}_{{\\mathrm{T}}}^{{\\mathrm{lipid}}}\\end{equation*}\\end{document}) compressibility, as well as the volume fluctuations. Differences in \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage

  14. Le traitement familial des enfants et des adolescents anorexiques : Des lignes directrices pour le médecin communautaire

    PubMed Central

    Findlay, S; Pinzon, J; Taddeo, D; Katzman, DK

    2010-01-01

    L’anorexie mentale (AM) est une maladie grave qui met la vie en danger et qui fait généralement son apparition pendant l’adolescence. Les données probantes au sujet du traitement optimal de l’AM chez les enfants et les adolescents sont en croissance, mais il reste beaucoup à apprendre. Même si les démarches thérapeutiques actuelles varient au Canada et ailleurs, les données jusqu’à présent indiquent que le traitement familial (TF) est le plus efficace pour les enfants et les adolescents anorexiques. Un élément essentiel du modèle de TF, c’est que les parents sont investis de la responsabilité de rétablir la santé physique de leur enfant et de s’assurer de la reprise complète de son poids. Le médecin qui comprend les principes fondamentaux et la philosophie du TF peut mettre en place les éléments de cette intervention fondée sur des faits probants auprès des jeunes patients anorexiques et de leur famille.

  15. Connecting Instructional and Cognitive Aspects of an LE: A Study of the Global Seminar Project

    ERIC Educational Resources Information Center

    Savelyeva, Tamara

    2012-01-01

    My research problem is based on the lack of unifying conceptual cohesion between the discourses concerning cognitive and instructional aspects of learning environments (LE). I contrast that lack with practical developments of LE studies connected at the level of practical implementation and evaluation. Next, I briefly review the LE boundaries,…

  16. Le contrôle de commutations dans une cellule bidirectionnelle bicommandable

    NASA Astrophysics Data System (ADS)

    Guillaud, X.; Deleu, A.; Degobert, P.; Hautier, J. P.

    1996-01-01

    A Power electronics static converter modulate the energy flowing between two different source types. This induce constraints in converter topology which need to be taken into account to drive the switches specially during the changeover between two switches belonging to the same cell. If the control logic is well known when using current or voltage bidirectionnal switches, we propose a method which fits to bidrivable, current and voltage bidirectionnal switches. Petri net are usefull tools to describe the switches themselves. Aplied to the cell description they permit us to generate a component logic drive in respect with energy constraints. Un convertisseur statique réalise une fonction de modulation de l'énergie transitant entre deux sources de nature différente. La nécessaire continuité énergétique induit des contraintes dans la topologie du convertisseur qui se répercutent sur la commande des composants qui le constituent, notamment lors de la phase de commutation entre deux interrupteurs d'une même cellule. Si les principes de commande sont bien connus pour les interrupteurs bidirectionnels en courant ou en tension, nous proposons dans cet article une méthode s'appliquant aux interrupteurs bicommandables et bidirectionnels à la fois en courant et en tension. Les réseaux de Petri constituent d'abord un outil de description précis des interrupteurs. Appliqués ensuite à la description du fonctionnement d'une cellule de commutation, ils deviennent alors un outil de synthèse conduisant à l'élaboration d'une logique de commande respectant les contraintes énergétiques dans tous les cas de figure.

  17. Pierre Curie et lele de la symétrie dans les lois physiques

    NASA Astrophysics Data System (ADS)

    de Gennes, P. G.

    Pierre et Jacques Curie découvraient il y a cent ans le phénomène de piézoélectricité : comment un cristal, de suffisamment basse symétrie, développe une polarization lorsqu'il est soumis à une contrainte mécanique. Pierre Curie n'a alors que 21 ans ! Et pourtant ses notes lapidaires aux Comptes Rendus datées de 1880 et 1881 [1] portent en elles tout l'essentiel du phénomène : charges superficielles proportionnelles à la pression, indépendantes de l'épaisseur du cristal, etc. Lorsque quelques mois plus tard, Lippmann prédit l'effet inverse (déformation du crystal sous champ électrique), les frères Curie imaginent tout de suite un dispositif admirablement simple pour détecter ces très faibles déformations. Ils couplent mécaniquement le cristal étudié avec un deuxième cristal piézoélectrique qui joue lele d'un détecteur; ce dernier transforme le signal mécanique du premier cristal en un signal électrique mesuré a l'électromètre ! Les résultats confirment brillamment la prédiction de Lippmann. Et pourtant, les moyens engagés sont très modestes — les champs électriques, par exemple, sont calibrés par la longueur d'une décharge dans l'air…

  18. Ultrafast intramolecular charge transfer with N-(4-cyanophenyl)carbazole. Evidence for a LE precursor and dual LE + ICT fluorescence.

    PubMed

    Galievsky, Victor A; Druzhinin, Sergey I; Demeter, Attila; Mayer, Peter; Kovalenko, Sergey A; Senyushkina, Tamara A; Zachariasse, Klaas A

    2010-12-09

    The photophysics of N-(4-cyanophenyl)carbazole (NP4CN) was investigated by using absorption and fluorescence spectra, picosecond fluorescence decays, and femtosecond transient absorption. In the nonpolar n-hexane as well as in the polar solvent acetonitrile (MeCN), a locally excited (LE) state is detected, as a precursor for the intramolecular charge transfer (ICT) state. A LE → ICT reaction time τ(2) at 22 °C of 0.95 ps in ethyl cyanide (EtCN) and 0.32 ps in MeCN is determined from the decay of the LE excited state absorption (ESA) maximum around 620 nm. In the ESA spectrum of NP4CN in n-hexane at a pump-probe delay time of 100 ps, an important contribution of the LE band remains alongside the ICT band, in contrast to what is observed in EtCN and MeCN. This shows that a LE ⇄ ICT equilibrium is established in this solvent and the ICT reaction time of 0.5 ps is equal to the reciprocal of the sum of the forward and backward ICT rate constants 1/(k(a) + k(d)). In the photostationary S(0) → S(n) absorption spectrum of NP4CN in n-hexane and MeCN, an additional CT absorption band appears, absent in the sum of the spectra of its electron donor (D) and acceptor (A) subgroups carbazole and benzonitrile. This CT band is located at an energy of ∼4000 cm(-1) lower than for N-phenylcarbazole (NPC), due to the larger electron affinity of the benzonitrile moiety of NP4CN than the phenyl subunit of NPC. The fluorescence spectrum of NP4CN in n-hexane at 25 °C mainly consists of a structured LE emission, with a small ICT admixture, indicating that a LE → ICT reaction just starts to occur under these conditions. In di-n-pentyl ether (DPeE) and di-n-butyl ether (DBE), a LE emission is found upon cooling at the high-energy edge of the ICT fluorescence band, caused by the onset of dielectric solvent relaxation. This is not the case in more polar solvents, such as diethyl ether (DEE) and MeCN, in which a structureless ICT emission band fully overlaps the strongly quenched LE

  19. Sur le chaos Lagrangien dans une cuve elliptique

    NASA Astrophysics Data System (ADS)

    Saatdjian, E.; Chassaing, M. I.; Midoux, N.; André, J. C.

    1995-02-01

    A viscous fluid is introduced into the annular space between two concentric, confocal ellipses. The inner and outer walls can be displaced along their circumference. A small quantity of fluorescent dye is introduced into the fluid and deformation and mixing are studied for the case of periodic boundary movement. An analytical solution in elliptical coordinates has been previously derived for creeping flow conditions. Poincaré sections for a given set of parameters indicate that counter-rotation leads to a more chaotic behaviour than co-rotation, this result is confirmed experimentally. This geometry can also be used as a heat exchanger. By a suitable choice of the parameters, the heat transfer for steady boundary motion can be increased by more than 50% with respect to the concentric cylinder system. If the inner and outer walls are displaced time-periodically, the heat transfer rate obtained can be more than double the rate obtained between concentric cylinders. Un fluide visqueux est introduit dans une cuve de géométrie elliptique, les parois interne et externe de cette cuve tournent suivant le périmètre de l'ellipse. Une petite quantité de traceur fluorescent est introduite dans le fluide et la déformation de l'élément marqué, lorsque le mouvement des deux parois est périodique, est étudiée. Pour cet écoulement où le nombre de Reynolds est très inférieur à 1 (régime de Stokes) et à partir d'une solution analytique récemmnent obtenue pour le cas stationnaire, des sections de Poincaré ont été tracées pour le cas d'une contra-rotation et d'une co-rotation. Les résultats expérimentaux montrent que, pour un protocole de mélange discontinu approprié, cette géométrie mène vers un mélange chaotique après un petit nombre de périodes. Par ailleurs, il est préférable de faire tourner les ellipses en contra-rotation. Ce résultat, en contradiction avec ceux déjà obtenus dans l'espace annulaire entre cylindres excentrés tournants, est

  20. Low-temperature heat capacity of diopside glass (CaMgSi2O6): A calorimetric test of the configurational-entropy theory applied to the viscosity of liquid silicates

    USGS Publications Warehouse

    Richet, P.; Robie, R.A.; Hemingway, B.S.

    1986-01-01

    Heat-capacity measurements have been made between 8 and 370 K on an annealed and a rapidly quenched diopside glass. Between 15 and 200 K, Cp does not depend significantly on the thermal history of the glass. Below 15 K Cp is larger for the quenched than for the annealed specimen. The opposite is true above 200 K as a result of what is interpreted as a secondary relaxation around room temperature. The magnitude of these effects, however, is small enough that the relative entropies S(298)-S(0) of the glasses differ by only 0.5 J/mol K, i.e., a figure within the combined experimental uncertainties. The insensitivity of relative entropies to thermal history supports the assumption that the configurational heat capacity of the liquid may be taken as the heat capacity difference between the liquid and the glass (??Cp). Furthermore, this insensitivity allows calculation of the residual entropies at 0 K of diopside glasses as a function of the fictive temperature from the entropy of fusion of diopside and the heat capacities of the crystalline, glassy and liquid phases. For a glass with a fictive temperature of 1005 K, for example, this calorimetric residual entropy is 24.3 ?? 3 J/mol K, in agreement with the prediction made by RICHET (1984) from an analysis of the viscosity data with the configurational-entropy theory of relaxation processes of Adam and Gibbs (1965). In turn, all the viscosity measurements for liquid diopside, which span the range 0.5-4?? 1013 poise, can be quantitatively reproduced through this theory with the calorimetrically determined entropies and ??Cp data. Finally, the unclear significance of "activation energies" for structural interpretations of viscosity data is emphasized, and the importance of ??Cp and glass-transition temperature systematics for determining the composition and temperature dependences of the viscosity is pointed out. ?? 1986.

  1. Thermodynamic data of lawsonite and zoisite in the system CaO-Al2O3-SiO2-H2O based on experimental phase equilibria and calorimetric work

    NASA Astrophysics Data System (ADS)

    Grevel, Klaus-Dieter; Schoenitz, Mirko; Skrok, Volker; Navrotsky, Alexandra; Schreyer, Werner

    2001-08-01

    The enthalpy of drop-solution in molten 2PbO.B2O3 of synthetic and natural lawsonite, CaAl2(Si2O7)(OH)2.H2O, was measured by high-temperature oxide melt calorimetry. The enthalpy of formation determined for the synthetic material is ΔfHOxides=-168.7+/-3.4 kJ mol-1, or ΔfH0298=-4,872.5+/-4.0 kJ mol-1. These values are in reasonable agreement with previously published data, although previous calorimetric work yielded slightly more exothermic data and optimisation methods resulted in slightly less exothermic values. The equilibrium conditions for the dehydration of lawsonite to zoisite, kyanite and quartz/coesite at pressures and temperatures up to 5 GPa and 850 °C were determined by piston cylinder experiments. These results, other recent phase equilibrium data, and new calorimetric and thermophysical data for lawsonite and zoisite, Ca2Al3(SiO4)(Si2O7)O(OH), were used to constrain a mathematical programming analysis of the thermodynamic data for these two minerals in the chemical system CaO-Al2O3-SiO2-H2O (CASH). The following data for lawsonite and zoisite were obtained: ΔfH0298 (lawsonite)=-4,865.68 kJ mol-1 , S0298 (lawsonite)=229.27 J K-1 mol-1 , ΔfH0298 (zoisite)=-6,888.99 kJ mol-1 , S0298 (zoisite)=297.71 J K-1 mol-1 . Additionally, a recalculation of the bulk modulus of lawsonite yielded K=120.7 GPa, which is in good agreement with recent experimental work.

  2. Le facteur XII de la coagulation: bien plus qu’un stabilisant de la fibrine

    PubMed Central

    Messaoudi, N.; Lamaalmi, F.; Chakour, M.; Belmekki, A.; Naji, M.

    2011-01-01

    Summary Les Auteurs considèrent lele du facteur XIII de la coagulation dans la cicatrisation. Identifié depuis 1923, lele du facteur XIII ou le facteur stabilisant de la fibrine dans la coagulation a été bien élucidé. Son rôle dans la cicatrisation suggéré dès 1960 est méconnu par les hématologistes et les médecins prenant en charge les brûlés. Les Auteurs se proposent de mettre la lumière sur ce rôle, qui reste encore mystérieux et mérite d’être élucidé. PMID:21991236

  3. Le Fort I Approach for Midline Tumors of the Palate.

    PubMed

    de Cevallos, Jorge Guiñales Díaz; Carretero, Jose L Cebrián; de Vera, Jose L Del Castillo Pardo; García, Miguel Burgueño

    2015-12-01

    Midline tumors of the palate may represent a challenge for the maxillofacial surgeon. Their resection and immediate reconstruction could be hindered when a simply intraoral approach is selected. The Le Fort I downfracture approach represents an ideal technique for the management of this tumors, simplifying their resection, ensuring a tumor-free margin, and allowing their reconstruction with a temporal muscle flap. A review of this procedure is presented, highlighting the technical keys and its principal advantages.

  4. [Complications in Le Fort facial fractures combined with craniocerebral trauma].

    PubMed

    Dimov, Zh; Abramov, G; Dimov, K; Kr'stev, N; Kr'stev, D

    1999-01-01

    The present research is based on the most frequent traumas and fractures in the middle zone of the face (second and third type by Rene le Fort) and the proceeded from them complications for a period of four years in the clinic of Neurosurgery in NIUMN "Pirogov". From the 280 patients that were studied the complications were observed in 54 of them. We worked up the received results statistically and presented them in drawing.

  5. Le kyste hydatique du cordon spermatique: une localisation exceptionnelle

    PubMed Central

    Hamdane, Mohamed Moncef; Bougrine, Fethi; Msakni, Issam; Dhaoui-Ghozzi, Amen; Bouziani, Ammar

    2011-01-01

    L’ hydatidose est une anthropo-zoonose due au développement chez l'homme de la forme larvaire du taenia Echinococcus granulosis. La plupart des kystes hydatiques se localisent dans le foie et les poumons. Le kyste hydatique du cordon spermatique est extrêmement rare avec seulement 4 cas rapportés dans la littérature. Les auteurs rapportent dans cet article un nouveau cas d'hydatidose du cordon spermatique. Il s'agissait d'un homme de 40 ans qui consultait pour des douleurs scrotales évoluant depuis huit mois. L'examen clinique a mis en évidence une tuméfaction mobile, inguino-scrotale, droite. L’échographie testiculaire a objectivé une hernie inguinale droite associée à deux kystes épididymaires bilatéraux. Le patient a été opéré pour cure de son hernie avec découverte en per-opératoire d'un kyste du cordon spermatique qui a été réséqué. L'examen anatomopathologique a conclu à une hydatidose du cordon spermatique. PMID:22384304

  6. Accuracy of a LeFort I maxillary osteotomy.

    PubMed

    Semaan, Steven; Goonewardene, Mithran S

    2005-11-01

    An optimal outcome of combined surgery and orthodontics involving the maxilla is dependent on many factors. Accurate placement of the maxilla by the surgical team is ultimately of paramount importance. The aim of this retrospective study was to evaluate the accuracy of LeFort I maxillary osteotomy with respect to the presurgical prediction. The sample comprised 42 patients (33 females, nine males) who had undergone LeFort I osteotomy procedure alone or in combination with a mandibular osteotomy with or without genioplasty. Tracings of presurgical and immediate postsurgical lateral cephalograms and surgical predictions were digitized and compared using Quick Ceph software analysis. Vertical and horizontal measurements to various skeletal landmarks were used to assess the discrepancy between the predicted maxillary position and the actual postsurgical result. Statistically significant differences were found between the predicted and actual postsurgical maxillary molar vertical position, and significant differences were also found for the palatal plane angular measurements. Two surgical teams were compared, and surgical team 1 had significantly less variation in the surgical outcomes than did surgical team 2. When single-jaw and bimaxillary surgery were compared, no significant differences were found. Similarly, there were no statistically significant differences found when assessing the primary direction of movement (impaction vs downgraft vs advancement). Overall, 66% of the results were within two mm of prediction and 26% of the results were within one mm of prediction. A LeFort I maxillary osteotomy can be an accurate procedure with a wide range of discrepancy.

  7. Airborne pollen and spores of León (Spain)

    NASA Astrophysics Data System (ADS)

    Fernández-González, Delia; Suarez-Cervera, María; Díaz-González, Tomás; Valencia-Barrera, Rosa María

    1993-06-01

    A qualitative and quantitative analysis of airborne pollen and spores was carried out over 2 years (from September 1987 to August 1989) in the city of León. Slides were prepared daily using a volumetric pollen trap, which was placed on the Faculty of Veterinary Science building (University of León) 12m above ground-level. Fifty-one pollen types were observed; the most important of these were: Cupressaceae during the winter, Pinus and Quercus in spring, and Poaceae, Leguminosae and Chenopodiaceae in the summer. The results also showed the existence of a rich mould spore assemblage in the atmosphere. The group of Amerospores ( Penicillium, Aspergillus and Cladosporium) as well as Dictyospores ( Alternaria) were the most abundant; Puccinia was common in the air in August. Fluctuations in the total pollen and spores m3 of air were compared with meteorological parameters (temperature, relative humidity and rainfall). From the daily sampling of the atmosphere of León, considering the maximum and minimum temperature and duration of rainfall, the start of the pollen grain season was observed generally to coincide with a rise in temperature in the absence of rain.

  8. Le sumatriptan intranasal pour la migraine chez les enfants

    PubMed Central

    Goldman, Ran D.; Meckler, Garth D.

    2015-01-01

    Résumé Question Je vois de plus en plus d’enfants et d’adolescents qui souffrent de céphalées pouvant se classer dans la catégorie des migraines. J’ai fait des lectures sur le sumatriptan par voie intranasale comme thérapie abortive. Est-ce un traitement efficace? Réponse La migraine aiguë chez les enfants et les adolescents est fréquente et difficile à traiter. Le sumatriptan intranasal est une option sûre et généralement efficace pour les enfants et les adolescents. La dose actuellement recommandée est de 20 mg pour les enfants qui pèsent plus de 40 kg et de 10 mg pour ceux dont le poids se situe entre 20 et 39 kg. Il faudrait faire des études de plus grande envergure pour contrecarrer les limitations des échantillons de petite taille et mieux comprendre la faible concentration plasmique et les effets placebo observés dans les études jusqu’à présent.

  9. Sequence diversity and enzyme activity of ferric-chelate reductase LeFRO1 in tomato.

    PubMed

    Kong, Danyu; Chen, Chunlin; Wu, Huilan; Li, Ye; Li, Junming; Ling, Hong-Qing

    2013-11-20

    Ferric-chelate reductase which functions in the reduction of ferric to ferrous iron on root surface is a critical protein for iron homeostasis in strategy I plants. LeFRO1 is a major ferric-chelate reductase involved in iron uptake in tomato. To identify the natural variations of LeFRO1 and to assess their effect on the ferric-chelate reductase activity, we cloned the coding sequences of LeFRO1 from 16 tomato varieties collected from different regions, and detected three types of LeFRO1 (LeFRO1(MM), LeFRO1(Ailsa) and LeFRO1(Monita)) with five amino acid variations at the positions 21, 24, 112, 195 and 582. Enzyme activity assay revealed that the three types of LeFRO1 possessed different ferric-chelate reductase activity (LeFRO1(Ailsa) > LeFRO1(MM) > LeFRO1(Monita)). The 112th amino acid residue Ala of LeFRO1 is critical for maintaining the high activity of ferric-chelate reductase, because modification of this amino acid resulted in a significant reduction of enzyme activity. Further, we showed that the combination of the amino acid residue Ile at the site 24 with Lys at the site 582 played a positive role in the enzyme activity of LeFRO1. In conclusion, the findings are helpful to understand the natural adaptation mechanisms of plants to iron-limiting stress, and may provide new knowledge to select and manipulate LeFRO1 for improving the iron deficiency tolerance in tomato.

  10. Nutrition chez le brûlé

    PubMed Central

    Perro, G.

    2016-01-01

    Summary La nutrition est un challenge chez le brûlé, paradigme de l’agressé. Les points importants sont les apports entéraux précoces par sonde gastrique voire post pyloriques, la position proclive > 30°, la surveillance du transit et sa régulation par gastro ou entéro-kinétiques, la surveillance du poids, la quantification des apports avec supplémentation parentérale en cas de retard protéino énergétique. Chez l’enfant, l’adhésion à l’alimentation est difficile, de même que chez le senior, où une évaluation nutritionnelle initiale dépiste souvent une dénutrition préexistante. Les compléments alimentaires seront largement prescrits chez les patients de gravité intermédiaire. Les obèses bénéficieront d’un régime hypocalorique et hyperprotidique. Chez l’insuffisant rénal non dialysé il convient de limiter les apports en potassium. En cas brûlure périnéale, on peut proposer soit une constipation de courte durée, soit la mise en place d’un entéro-collecteur, les indications de colostomie étant devenues rares. Les apports entéraux sont difficiles à gérer en cas de décubitus ventral pour SDRA. Chez le brûlé grave de réanimation, l’accent doit plus être mis sur la qualité des nutriments que sur leur quantité. Les anciennes formules d’estimation calorique conduisaient à une surnutrition difficile à administrer et en général mal tolérée; la quantification mesurée par calorimétrie indirecte ou estimée par la formule de Toronto est bien plus adaptée. Plus récemment, l’instauration d’une immunonutrition (supplémentation en vitamines et oligo-éléments, glutamine, arginine, acide Ω 3 et contrôle raisonné de la glycémie) a été proposée pour réduire le stress oxydatif et l’inflammation provoqués par l’accident. PMID:27857647

  11. Le tetanos chez le grand enfant dans un hôpital pédiatrique à Yaoundé, Cameroun

    PubMed Central

    Ntoto Njiki Kinkela, Mina; Nguefack, Félicitée; Mbassi Awa, Hubert; Chelo, David; Enyama, Dominique; Mbollo Kobela, Marie; Koki Ndombo, Paul Olivier

    2012-01-01

    Le tétanos est évitable par la vaccination, mais peut survenir en cas d'une immunisation incomplète. Nous avons mené une étude sur les dossiers médicaux des enfants admis pour tétanos entre 2008-2009 au Centre Mère et Enfant de la Fondation Chantal BIYA à Yaoundé. Le but était d'analyser les circonstances de survenue et les manifestations cliniques du tétanos chez le grand enfant, afin de proposer des stratégies de prévention adaptées au contexte camerounais. Le statut vaccinal était inconnu chez un patient, les autres (80%) n'avaient pas reçu de rappel vaccinal. Les portes d'entrée étaient les plaies aux membres, l'une était secondaire à une injection médicamenteuse. Tous ont présenté le tétanos généralisé. Le décès était survenu chez un patient. Le tétanos n'est pas rare chez le grand enfant au Cameroun. Il se dégage ainsi la problématique des rappels vaccinaux. PMID:22514771

  12. Primary Attraction of Ips latidens (LeConte) and Hylastes Gracilis LeConte (Coleoptera: Scolytidae) to High-Girdled Lodgepole Pine, Pinus Contorta var. Latifolia Engelmann

    Treesearch

    D.R. Miller; J.L. Madden; J.H. Borden

    1986-01-01

    In the absence of secondary attraction, 2 species of Scolytidae, Ips latidens (LeConte) and Hylastes gracilis LeConte, showed significant preference while in flight for high-girdled over non-girdled lodgepole pines, Pinus contorta var. latifolia Engelmann. In contrast, beetles in 2 genera...

  13. Le stéréorestituteur Kelsh

    USGS Publications Warehouse

    Kelsh, H.T.

    1949-01-01

    Le ste??re??orestituteur Kelsh est un appareil de restitution a?? double projection base?? sur le principe des anaglyphes, comme le Multiplex par exemple, mais il a une plus grande pre??cision que ce dernier, vu que les ne??gatifs sont utilise??s directement pour la restitution, sans que l'on soit oblige?? de les re??duire au pre??alable. Une telle solution devient possible lorsque l'e??chelle de l'image plastique (mode??le) est au moins 7 fois plus grande que celle des cliche??s. L'appareil comprend un support reposant par 4 pieds sur la table a?? dessin. Sa partie supe??rieure porte, par l'interme??diaire de trois vis calantes, un cadre dans lequel les deux chambres de projection sont suspendues. Des leviers de commande, agissant sur les chambres, permettent d'introduire la base, le de??versement et les inclinaisons transversale et longitudinale. Les cliche??s conjugue??s ou des diapositifs sont directement place??s dans les chambres de projection munies d'objectifs. En projetant les deux cliche??s au moyen de couleurs comple??mentaires, l'observateur - muni de lunettes a?? verres colore??s (couleurs comple??mentaires) - observe l'image plastique audessus de la table a?? dessin, l'orientation relative des chambres ayant e??te?? e??tablie au pre??alable. Pour le report des points de l'image plastique sur la minute, l'ope??rateur dispose d'une tablette amovible a?? marque-repe??re lumineuse qu'il de??place a?? la main et dont la hauteur au-dessus de la table a?? dessin peut e??tre commande??e par une molette. Pour e??tablir l'orientation absolue de l'image plastique, il suffit d'incliner convenablement le cadre de suspension a?? l'aide des vis calantes, l'orientation relative n'e??tant pas de??truite par cette ope??ration. Les deux cliche??s sont e??claire??s par des projecteurs munis d'une suspension a?? la cardan et relie??s a?? la tablette de restitution par des tiges te??lescopiques. Moyennant ce dispositif, l'e??clairage est concentre?? sur deux petites re

  14. Le médicament générique au Maroc: le point de vue du consommateur

    PubMed Central

    Zaoui, Sanaa; Hakkou, Farid; Filali, Houda; Khabal, Youssef; Tazi, Illias; Mahmal, Lahoucine

    2013-01-01

    Introduction Le médicament générique est souvent une origine de préjugés négatifs et de méfiance chez les professionnels de santé et les patients. Ceci pourrait être dû à plusieurs facteurs entre autre le manque des connaissances du patient sur ces médicaments. Le but de notre étude était d’évaluer l'information du consommateur sur les médicaments génériques et apprécier leur utilisation de ces médicaments. Méthodes Il s'agit d'une étude transversale réalisée de Janvier à Mars 2010 auprès de 251 sujets. Un questionnaire comprenant dix questions fermées a été utilisé. Les questions concernaient l’évaluation des connaissances sur les médicaments génériques, les sources d'information, le degré de confiance et d'information des patients sur ces médicaments. Une analyse descriptive simple des différentes variables a été réalisée. Résultats Dans notre étude, 126 sujets (50,2%) ont répondu connaître les médicaments génériques. Parmi eux, 52,3% les utilisaient et 67,4% estimaient qu'ils étaient insuffisamment informés sur ces médicaments. Les cadres supérieurs et les étudiants ont représenté la catégorie qui utilisait le plus les médicaments génériques (respectivement dans 40,9% et 25,7%) et qui était la mieux informée (respectivement dans 61,9% et 23,81%). Le faible coût a été la principale motivation d'utilisation du médicament générique (93,9%). Les médias ont représenté la première source d'information (59,5%). Après sensibilisation, 88,8% des sujets qui ne connaissaient pas le médicament générique ont été favorable à son utilisation. Conclusion Une promotion efficace par une politique d'information soutenue auprès des consommateurs et par des mesures incitatrices à la prescription et à la délivrance du générique par les médecins et les pharmaciens, pourront améliorer l'utilisation de ces médicaments dans notre pays. PMID:24009794

  15. Snow in Castile-León: trends and variability

    NASA Astrophysics Data System (ADS)

    Merino, A.; Campos, L.; López, L.; García-Ortega, E.; Sánchez, J. L.; Marcos, J. L.; Guerrero-Higueras, A. M.

    2012-04-01

    The location of Castile and León, inside the Iberian Peninsula, in the Northwestern quadrant, determines, in large measure, the climatic conditions of its territory, granting it very characteristic traits, mostly in the mountainous areas. It is important to note that during a large part of the year, the region is under the influence of Jet Stream, and thus, gives way to very diverse dynamic situations, which turn into different and heterogeneous types of weather. So, in many areas of the region, especially in the most elevated areas, these synoptic and mesoscale situations generate snow precipitation. We should point out that snowfall is one of the principal meteorological risks of Castile and León. Thus, on average, in some mountainous areas there are more than 40 events of snowfall registered annually, with the month of January being the month in which the highest frequency of snowfall appears. The social repercussions of this snowfall are represented in the isolation of places, essentially mountainous, highways being blocked, increase in traffic accidents, etc. As proof of this, it is this type of episode that receives ample coverage by the media, which has a linear relationship with the social perception of risk. As such, the objective of the current work is to analyze the annual trend of days with snow in the different meteorological stations pertaining to AEMET placed in the Community. The period of study is from 1960-2010. Additionally, we have also evaluated trends in annual days of freezing temperature and annual absolute minimum temperature, with the objective of facilitating a meteorological interpretation of the trends obtained on days with snowfall. Finally, the results show that in the majority of stations, a significant negative trend in days with snowfall and annual days with freezing temperatures, and a positive trend in annual absolute minimum temperatures. However, we observed variability in the different regions in the area of study

  16. Stratégie de traitement : Rôle de l’enfuvirtide dans la prise en charge des effets secondaires limitant le traitement

    PubMed Central

    Tsoukas, Christos

    2007-01-01

    Les effets secondaires peuvent limiter les options s’offrant aux médecins dans le traitement de l’infection par le VIH. La prise en charge de ces effets secondaires est essentielle afin d’éviter l’arrêt du traitement. L’enfuvirtide, un inhibiteur de la fusion du VIH, peut être utile en tant qu’un des trois agents actifs du traitement antirétroviral. Ce peut être une façon de réduire les effets secondaires limitant le traitement et d’avoir un agent efficace pour le contrôle viral. Dans le cas présent, le patient avait des antécédents de traitements longs et problématiques, avec de nombreuses affections concomitantes. Son dernier schéma thérapeutique en date, qui comprend un agent d’une nouvelle classe thérapeutique, l’enfuvirtide, a maintenu la suppression du VIH tout en minimisant la toxicité.

  17. The rôle of planetaria: The Library of Alexandria Planetarium Science Center

    NASA Astrophysics Data System (ADS)

    El-Mitaky, Hoda S.

    2011-06-01

    In ancient times the stars and the Moon were humans' only guide to cross the seas and explore the depths of the deserts. With the use of modern technological gadgets, and the increasingly light pollution, citizens of the world stopped looking at the heavens. How can planetaria play a rôle in reviving public interest in astronomy? How can the beauty of astronomy play a rôle in luring the youth to pursue a career in science? How can astronomy play a rôle in raising public awareness about preserving the environment? Moreover, how can astronomy play a rôle in the dialogue among civilisations?

  18. Le consentement libre et éclairé aux soins en psychiatrie

    PubMed Central

    Neilson, Grainne; Chaimowitz, Gary

    2015-01-01

    Résumé Le patient a le droit d’être informé sur les soins de santé qui lui sont proposés et de participer activement à la prise de décisions relativement à ces soins. Le respect de la dignité et de l’autonomie de la personne passe par le respect de son droit de prendre des décisions à propos de ses soins psychiatriques, notamment de refuser un traitement, pour autant qu’elle soit apte à prendre des décisions. Il importe que le psychiatre connaisse les fondements éthiques du consentement libre et éclairé et les exigences prévues par le droit en cette matière, y compris la jurisprudence. Le consentement n’est pas immuable, pouvant changer avec le temps, au fil de l’évolution des conditions et des circonstances. Par conséquent, le consentement doit être un processus continu.

  19. Le gingembre contre la nausée et les vomissements de la grossesse

    PubMed Central

    Lindblad, Adrienne J.; Koppula, Sudha

    2016-01-01

    Question clinique Le gingembre peut-il traiter la nausée et les vomissements de la grossesse? Résultats Durant le premier trimestre, le gingembre soulagerait la nausée et les vomissements de quelque 4 points sur une échelle de 40 points, ou éliminerait les vomissements chez 1 femme sur 3 au jour 6. L’étude la plus vaste ne laisse croire à aucune hausse des malformations congénitales ou de la mortinatalité, mais les études de moins grande envergure laissent croire le contraire.

  20. Le genre Tunga Jarocki, 1838 (Siphonaptera : Tungidae). I – Taxonomie, phylogénie, écologie, rôle pathogène

    PubMed Central

    Beaucournu, J.-C.; Degeilh, B.; Mergey, T.; Muñoz-Leal, S.; González-Acuña, D.

    2012-01-01

    Pour la première fois, les 12 espèces actuellement décrites dans le genre Tunga sont étudiées sur le plan de la taxonomie et de la répartition. Divers aspects de leur biologie et leur rôle pathogène sont également envisagés, et en particulier leur phylogénie, leur chorologie, leur phénologie, leur sexe-ratio et leurs dermecos. PMID:23193514

  1. Repenser ensemble le concept d'autonomie alimentaire.

    PubMed

    Bélisle, Micheline; Labarthe, Jenni; Moreau, Cynthia; Landry, Elise; Adam, Gracia; Bourque Bouliane, Mijanou; Dupéré, Sophie

    2017-03-01

    C'est au cœur du projet de recherche-action participative « Vers une autonomie alimentaire pour tou-te-s : agir et vivre ensemble le changement » (VAATAVEC) que s'est élaborée une définition nouvelle et évolutive de l'autonomie alimentaire. De ce projet regroupant des personnes en situation de pauvreté, chercheurs et intervenants, a émergé une conceptualisation résultant à la fois d'une méthode de réflexion collective et d'un processus d'analyse collective, inspiré de la théorisation ancrée et de l'analyse conceptualisante de Paillé et Mucchielli (2003). Le recours à l'expertise des personnes en situation de pauvreté, expertes du vécu de l'insécurité alimentaire, a contribué à ancrer cette définition dans les causes structurelles de l'insécurité alimentaire dans une perspective de développement d'un pouvoir d'agir collectif, de toutes les personnes concernées. Il en résulte une définition de l'autonomie alimentaire d'où ressort une contribution surtout méthodologique et théorique.

  2. Magnetic study of the Ca{sub 1-x}Eu{sub x}MnO{sub 3} (O {le} x {le} 1) perovskites

    SciTech Connect

    Troyanchuk, I.O.; Samsonenko, N.V.; Szymczak, H.; Nabialek, A.

    1997-06-01

    The magnetization and crystal structure of Ca{sub 1-x}EuMnO{sub 3} (0 {le} x {le} 1) perovskites have been studied. It is shown that these compounds present four concentration regions in which different magnetic phases coexist. The antiferromagnetic phase is associated with a regular arrangement of Mn{sup 3+} and Mn{sup 4+} ions in ratios 1:3 and 1:1. The ferromagnetic phase is attributed to the charge disordered states and is found in 0 {le} x {le} 0.2 and 0.6 < x < 1 concentration ranges. The samples 0.1 < x < 0.2 show metamagnetic behavior which might result from the collapse of the charge ordered state (1:3). The CaMnO{sub 2.94} and EuMnO{sub 3.02} are weak ferromagnets with T{sub N} = 122 and 40 K, respectively.

  3. Determination of electronic stopping powers of 0.05-1 MeV/u 131Xe ions in C-, Ni- and Au-absorbers with calorimetric low temperature detectors

    NASA Astrophysics Data System (ADS)

    Echler, A.; Egelhof, P.; Grabitz, P.; Kettunen, H.; Kraft-Bermuth, S.; Laitinen, M.; Müller, K.; Rossi, M.; Trzaska, W. H.; Virtanen, A.

    2017-01-01

    A new experimental system for precise determination of electronic stopping powers of heavy ions has been set up at the accelerator laboratory of the University of Jyväskylä. The new setup, combining an established B-ToF system and an array of calorimetric low temperature detectors (CLTDs), has been used for the determination of electronic stopping powers of 0.05-1 MeV/u 131Xe ions in carbon, nickel and gold. Thereby advantage of the improved linearity and energy resolution of CLTDs as compared to the previously used ionization detector was taken to reduce energy calibration errors and to increase sensitivity for the energy loss determination, in particular at very low energies. The total uncertainties of 3-4% for C- and Ni-targets, and 5-7% for Au-targets, respectively, are dominated by the target properties, i.e. thickness determination and inhomogeneities. The results are compared to data from literature and to predictions of different theoretical computer codes. In the high energy part of the examined energy range the results are in good agreement with previously published data, while new stopping power data for very heavy ions in different Z2-materials have been obtained at lower energies. Moreover, unexpectedly strong channeling effects for the transmission of the 131Xe ions in thin, partly polycrystalline nickel and gold target foils have been observed and investigated.

  4. Temperature-dependent interactions and disorder in the spin-transition compound [Fe(II)(L)2][ClO4]2.C7H8 through structural, calorimetric, magnetic, photomagnetic, and diffuse reflectance investigations.

    PubMed

    Mishra, Vibha; Mukherjee, Rabindranath; Linares, Jorge; Balde, Chérif; Desplanches, Cédric; Létard, Jean-François; Collet, Eric; Toupet, Loic; Castro, Miguel; Varret, François

    2008-09-01

    The title compound [Fe (II)(L) 2][ClO 4] 2.C 7H 8 (L = 2-[3-(2'-pyridyl)pyrazol-1-ylmethyl]pyridine) has been isolated while attempting to grow single crystals of the spin-transition (continuous-type) compound [Fe (II)(L) 2][ClO 4] 2, published earlier ( Dalton Trans. 2003, 3392-3397). Magnetic susceptibility measurements, as well as Mossbauer and calorimetric investigations on polycrystalline samples of [Fe(L) 2][ClO 4] 2.C 7H 8 revealed the occurrence of an abrupt HS ( (5) T 2) <--> LS ( (1) A 1) transition with steep and narrow (2 K) hysteresis at approximately 232 K. The photomagnetic properties exhibit features typical for a broad distribution of activation energies, with relaxation curves in the shape of stretched exponentials. We performed a crystal structure determination of the compound at 120, 240, and 270 K. A noteworthy temperature-dependent behavior of the structural parameters was observed, in terms of disorder of both the anions and solvent molecules, leading to a strong thermal dependence of the strength and dimensionality of the interaction network. Additional data were obtained by diffuse reflectance measurements. We model and discuss the antagonistic effects of interactions and disorder by using a two-level cooperative mean-field approach which includes a distribution of barrier energies at the microscopic scale.

  5. Polystyrene nanoparticles in the presence of (ethylene oxide)13(propylene oxide)30(ethylene oxide)13, N,N-dimethyloctylamine-N-oxide and their mixtures. A calorimetric and dynamic light scattering study.

    PubMed

    De Lisi, R; Lazzara, G; Milioto, S; Muratore, N

    2008-02-14

    Polystyrene nanoparticles were synthesized by emulsion polymerization of styrene. They were functionalized using the conventional surfactant N,N-dimethyloctylamine-N-oxide (ODAO), the tri-block copolymer (ethylene oxide)(13)(propylene oxide)(30)(ethylene oxide)(13) (L64) and their mixtures. To this purpose, dynamic light scattering and calorimetric experiments were carried out and provided information consistent to each other. The L64 adsorption is Langmuir-type in the copolymer dilute regime and generates complex structures at larger concentrations. In the region where ODAO is in the unimeric state, the adsorption process is cooperative leading to hemi-micelle formation at the polystyrene nanoparticle/water interface. In the concentrated region (above the critical micellar concentration), ODAO forms micelles which interact with the solid substrate most likely through ion-dipole forces. The ODAO addition to the dispersion containing polystyrene particles already wrapped by L64 creates an ODAO thickness around the dispersed particles the size of which is equal to that in the absence of the copolymer, but is built at much lower concentrations. A plausible interpretation of this behavior is that the adsorbed L64 confers to the nanoparticles surface novel properties which enhance the attractive forces with the ODAO molecules.

  6. CoLeMo: A Collaborative Learning Environment for UML Modelling

    ERIC Educational Resources Information Center

    Chen, Weiqin; Pedersen, Roger Heggernes; Pettersen, Oystein

    2006-01-01

    This paper presents the design, implementation, and evaluation of a distributed collaborative UML modelling environment, CoLeMo. CoLeMo is designed for students studying UML modelling. It can also be used as a platform for collaborative design of software. We conducted formative evaluations and a summative evaluation to improve the environment and…

  7. LeY oligosaccharide upregulates DAG/PKC signaling pathway in the human endometrial cells.

    PubMed

    Li, Yali; Ma, Keli; Sun, Ping; Liu, Shuai; Qin, Huamin; Zhu, Zhengmei; Wang, Xiaoqi; Yan, Qiu

    2009-11-01

    LeY oligosaccharide is stage specifically expressed by the embryo and uterine endometrium, and it plays important roles in embryo implantation. In addition to participating in the recognition and adhesion on fetal-maternal interface, LeY potentially regulates the expression of some implantation-related factors. However, it remains elusive whether it can mediate the involved signaling pathway. In this study, agarose-LeY beads were used to mimic the embryos, and the effects of LeY oligosaccharide on DAG/PKC signaling pathway was studied in human endometrial epithelial cells. Results showed that LeY could significantly trigger the activation of cPKCalpha and cPKCbeta2, and their translocation from the cytosol to the plasma membrane. The cellular DAG content was also upregulated, and the activation of PLCgamma1 was promoted. On the contrary, DAG/PKC signaling pathway was significantly inhibited when anti-LeY antibody was used after confirmation of LeY expression in human endometrial epithelial cells by immunohistochemistry and flow cytometry. These results suggest that LeY oligosaccharide acts as a signal molecule to modulate DAG/PKC signaling pathway.

  8. Use of Mobile Testing System PeLe for Developing Language Skills

    ERIC Educational Resources Information Center

    Titova, Svetlana

    2015-01-01

    One of the objectives of this paper is to investigate the pedagogical impact of both the mobile testing system PeLe (Norway, HiST) and the enquiry-based learning approach on language skills development in the context of mobile-assisted learning. The research aims to work out a methodological framework of PeLe implementation into the language…

  9. CoLeMo: A Collaborative Learning Environment for UML Modelling

    ERIC Educational Resources Information Center

    Chen, Weiqin; Pedersen, Roger Heggernes; Pettersen, Oystein

    2006-01-01

    This paper presents the design, implementation, and evaluation of a distributed collaborative UML modelling environment, CoLeMo. CoLeMo is designed for students studying UML modelling. It can also be used as a platform for collaborative design of software. We conducted formative evaluations and a summative evaluation to improve the environment and…

  10. MODeLeR: A Virtual Constructivist Learning Environment and Methodology for Object-Oriented Design

    ERIC Educational Resources Information Center

    Coffey, John W.; Koonce, Robert

    2008-01-01

    This article contains a description of the organization and method of use of an active learning environment named MODeLeR, (Multimedia Object Design Learning Resource), a tool designed to facilitate the learning of concepts pertaining to object modeling with the Unified Modeling Language (UML). MODeLeR was created to provide an authentic,…

  11. MODeLeR: A Virtual Constructivist Learning Environment and Methodology for Object-Oriented Design

    ERIC Educational Resources Information Center

    Coffey, John W.; Koonce, Robert

    2008-01-01

    This article contains a description of the organization and method of use of an active learning environment named MODeLeR, (Multimedia Object Design Learning Resource), a tool designed to facilitate the learning of concepts pertaining to object modeling with the Unified Modeling Language (UML). MODeLeR was created to provide an authentic,…

  12. An Overview-NASA LeRC Structures Program

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1997-01-01

    The Structures and Acoustics Division of the NASA Lewis Research Center has its genesis dating back to 1943. It has been an independent Division at Lewis since 1979. Its two primary capabilities are performance and life analysis of static and dynamic systems such as those found in aircraft and spacecraft propulsion systems and experimental verification of these analyses. Research is conducted in-house, through university grants and contracts, and through cooperative programs with industry. Our work directly supports NASA's Advanced Subsonic Technology (AST), Smart Green Engine, Fast Quiet Engine, High-Temperature Materials and Processing (HiTEMP), Hybrid Hyperspeed Propulsion, Rotorcraft, High-Speed Research (HSR), and Aviation Safety Program (AvSP). A general overview is given discussing these programs and other technologies that are being developed at NASA LeRC.

  13. Design of Multidimensional Shinnar-Le Roux RF Pulses

    PubMed Central

    Ma, Chao; Liang, Zhi-Pei

    2014-01-01

    Purpose To generalize the conventional Shinnar-Le Roux (SLR) method for the design of multidimensional RF pulses. Methods Using echo-planar gradients, the multidimensional RF pulse design problem was converted into a series of 1D polynomial design problems. Each of the 1D polynomial design problems was solved efficiently. B0 inhomogeneity compensation and design of spatial-spectral pulses were also considered. Results The proposed method was used to design 2D excitation and refocusing pulses. The results were validated through Bloch equation simulation and experiments on a 3.0 T scanner. Large-tip-angle, equiripple-error, multidimensional excitation was achieved with ripple levels closely matching the design specifications. Conclusion The conventional SLR method can be extended to design multidimensional RF pulses. The proposed method achieves almost equiripple excitation errors, allows easy control of the tradeoff among design parameters, and is computationally efficient. PMID:24578212

  14. The NASA-LeRC wind turbine sound prediction code

    NASA Technical Reports Server (NTRS)

    Viterna, L. A.

    1981-01-01

    Since regular operation of the DOE/NASA MOD-1 wind turbine began in October 1979 about 10 nearby households have complained of noise from the machine. Development of the NASA-LeRC with turbine sound prediction code began in May 1980 as part of an effort to understand and reduce the noise generated by MOD-1. Tone sound levels predicted with this code are in generally good agreement with measured data taken in the vicinity MOD-1 wind turbine (less than 2 rotor diameters). Comparison in the far field indicates that propagation effects due to terrain and atmospheric conditions may be amplifying the actual sound levels by about 6 dB. Parametric analysis using the code has shown that the predominant contributions to MOD-1 rotor noise are: (1) the velocity deficit in the wake of the support tower; (2) the high rotor speed; and (3) off column operation.

  15. LeRoy Doggett and Daylight Saving Time: A Reminiscence

    NASA Astrophysics Data System (ADS)

    Bartky, I. R.

    1997-12-01

    Daylight Saving Time (DST) has been a concern of Congress ever since its adoption in 1918. Yet, not until 1976 did Members of Congress have astronomical, geographic and demographic information in terms of the country's Standard Time zones. This information and various impact analyses were developed by the National Bureau of Standards (NBS) at the request of the House of Representatives, which was reviewing the effects of a two-year, DST experiment on the American public. The displays in the study gave legislators a way to consider alternate observance periods in a systematic manner. The leader of the DST study team will detail LeRoy Doggett's involvement during the hectic, three-month analysis period that culminated with NBS officials testifying before Congress.

  16. An Overview-NASA LeRC Structures Program

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1997-01-01

    The Structures and Acoustics Division of the NASA Lewis Research Center has its genesis dating back to 1943. It has been an independent Division at Lewis since 1979. Its two primary capabilities are performance and life analysis of static and dynamic systems such as those found in aircraft and spacecraft propulsion systems and experimental verification of these analyses. Research is conducted in-house, through university grants and contracts, and through cooperative programs with industry. Our work directly supports NASA's Advanced Subsonic Technology (AST), Smart Green Engine, Fast Quiet Engine, High-Temperature Materials and Processing (HiTEMP), Hybrid Hyperspeed Propulsion, Rotorcraft, High-Speed Research (HSR), and Aviation Safety Program (AvSP). A general overview is given discussing these programs and other technologies that are being developed at NASA LeRC.

  17. Aerospace Test Facilities at NASA LeRC Plumbrook

    NASA Technical Reports Server (NTRS)

    1992-01-01

    An overview of the facilities and research being conducted at LeRC's Plumbrook field station is given. The video highlights four main structures and explains their uses. The Space Power Facility is the world's largest space environment simulation chamber, where spacebound hardware is tested in simulations of the vacuum and extreme heat and cold of the space plasma environment. This facility was used to prepare Atlas 1 rockets to ferry CRRES into orbit; it will also be used to test space nuclear electric power generation systems. The Spacecraft Propulsion Research Facility allows rocket vehicles to be hot fired in a simulated space environment. In the Cryogenic Propellant Tank Facility, researchers are developing technology for storing and transferring liquid hydrogen in space. There is also a Hypersonic Wind Tunnel which can perform flow tests with winds up to Mach 7.

  18. Plasma Science Contribution to the SCaLeS Report

    SciTech Connect

    S.C. Jardin

    2003-10-09

    In June of 2003, about 250 computational scientists and mathematicians being funded by the DOE Office of Science met in Arlington, VA, to attend a 2-day workshop on the Science Case for Large-scale Simulation (SCaLeS). This document was the output of the Plasma Science Section of that workshop. The conclusion is that exciting and important progress can be made in the field of Plasma Science if computer power continues to grow and algorithmic development continues to occur at the rate that it has in the past. Full simulations of burning plasma experiments could be possible in the 5-10 year time frame if an aggressive growth program is launched in this area.

  19. Neptune's Discovery: Le Verrier, Adams, and the Assignment of Credit

    NASA Astrophysics Data System (ADS)

    Sheehan, William

    2011-01-01

    As one of the most significant achievements of 19th century astronomy, the discovery of Neptune has been the subject of a vast literature. A large part of this literature--beginning with the period immediately after the optical discovery in Berlin--has been the obsession with assigning credit to the two men who attempted to calculate the planet's position (and initially this played out against the international rivalry between France and England). Le Verrier and Adams occupied much different positions in the Scientific Establishments of their respective countries; had markedly different personalities; and approached the investigation using different methods. A psychiatrist and historian of astronomy tries to provide some new contexts to the familiar story of the discovery of Neptune, and argues that the personalities of these two men played crucial roles in their approaches to the problem they set themselves and the way others reacted to their stimuli. Adams had features of high-functioning autism, while Le Verrier's domineering, obsessive, orderly personality--though it allowed him to be immensely productive--eventually led to serious difficulties with his peers (and an outright revolt). Though it took extraordinary smarts to calculate the position of Neptune, the discovery required social skills that these men lacked--and thus the process to discovery was more bumbling and adventitious than it might have been. The discovery of Neptune occurred at a moment when astronomy was changing from that of heroic individuals to team collaborations involving multiple experts, and remains an object lesson in the sociological aspects of scientific endeavor.

  20. Dysfonctionnements radio-induits du transport colique chez le rat

    NASA Astrophysics Data System (ADS)

    François, A.; Lebrun, F.; Ksas, B.; Aigueperse, J.; Gourmelon, P.; MacNaughton, W. K.; Griffiths, N. M.

    1998-04-01

    The symptom commonly associated with whole body irradiation is diarrhoea, a still quite obscure phenomenon, which leads to decreased chance of cure of irradiated people. The aim of this study was to provide evidence for dysfunction of intestinal water and electrolyte transport regulation by the enteric nervous system after exposure to ionising radiation. This study shows decreased capacity of enteric nervous system to influence colonic transport 3days after irradiation, correlated to a diminished response to a neurotransmitter: serotonin. Radio-induced diarrhea may result from epithelial structural injury but also from impaired regulatory processes of intestinal transport. L'un des symptômes majeurs d'une irradiation corporelle totale ou abdominale est l'apparition de diarrhées, dont les causes sont encore mal connues, et qui mettent en jeu le pronostique vital de l'individu irradié. Cette étude vise à mettre en évidence l'atteinte de la régulation du transport intestinal d'eau et d'électrolytes par les rayonnements ionisants. On observe une diminution de la capacité du système nerveux entérique à influencer le transport colique 3jours après irradiation, corrélée à une diminution de la réponse épithéliale à un neurotransmetteur : la sérotonine. Les diarrhées radio-induites résulteraient d'une atteinte structurelle de l'épithélium mais également des processus de régulation du transport intestinal.

  1. Les fluctuations supraconductrices dans le compose praseodyme-cerium-oxyde de cuivre

    NASA Astrophysics Data System (ADS)

    Renaud, Jacques

    Ce travail etudie les fluctuations supraconductrices dans le compose supraconducteur a haute temperature critique dope aux electrons Pr2-xCe xCuO4+delta. La technique utilisee pour sonder ces fluctuations est le transport electrique DC dans le plan ab. Il s'agit, a notre connaissance, de la premiere etude de ce type dans la classe generale des supraconducteurs a haute temperature critique dopes aux electrons et, plus particulierement, dans Pr2-xCe xCuO4+delta. De plus, l'etude est effectuee pour trois regimes de dopage, soit sous-dope x = 0.135, dopage optimal x = 0.15 et surdope x = 0.17. Les echantillons etudies sont des couches minces d'epaisseur plus grande que 100 nm crues par ablation laser. Les mesures electriques DC effectuees dans ce travail sont la resistance en reponse lineaire et les courbes IV en reponse non lineaire en fonction de la temperature. La mise en oeuvre experimentale de ces mesures a necessite une grande attention au filtrage et aux effets de chauffage a haut courant. Nous montrons que, sans cette attention, les donnees experimentales sont toujours erronees dans le regime pertinent pour nos echantillons. Les resultats pour le dopage optimal x = 0.15 sont expliques de facon tres convaincante dans le cadre de fluctuations purement 2D. D'abord, le regime des fluctuations gaussiennes est tres bien decrit par le modele d'Aslamazov-Larkin en deux dimensions. Ensuite, le regime de fluctuations critiques, se trouvant a plus basse temperature que le regime gaussien, est tres bien decrit par la physique 2D de Kosterlitz-Thouless. Dans cette analyse, les deux regimes ont des temperatures critiques coherentes entre elles, ce qui semble confirmer ce scenario 2D. Une analyse des donnees dans le cadre de fluctuations 3D est exploree mais donne des conclusions incoherentes. Les resultats pour les autres dopages sont qualitativement equivalents avec le dopage optimal et permettent donc une explication purement 2D. Par contre, contrairement au dopage optimal

  2. Overexpression of the tomato pollen receptor kinase LePRK1 rewires pollen tube growth to a blebbling mode

    USDA-ARS?s Scientific Manuscript database

    The tubular growth of a pollen tube cell is crucial for the sexual reproduction of flowering plants. LePRK1 is a pollen-specific and plasma membrane–localized receptor-like kinase from tomato (Solanum lycopersicum). LePRK1 interacts with another receptor, LePRK2, and with KINASE PARTNER PROTEIN (KPP...

  3. Specific role of LeMAN2 in the control of seed germination exposed by overexpression of the LeMAN3 gene in tomato plants.

    PubMed

    Belotserkovsky, Harel; Berger, Yael; Shahar, Ron; Wolf, Shmuel

    2007-12-01

    Endo-beta-mannanase is one of the key enzymes involved in the hydrolysis of the mannan-rich cell walls of tomato (Solanum lycopersicon) seeds. Two isoforms of endo-beta-mannanase have been characterized in tomato seeds: LeMAN2 is active in the micropylar area prior to germination and LeMAN1 is active after germination in all endosperm cells surrounding the cotyledons. To explore whether general mannanase activity in the endosperm cap is sufficient to promote germination, the gene encoding LeMAN3 was inserted into transgenic tomato plants under the control of a CaMV-35S promoter. Expression of LeMAN3 was evident in the endosperm cap and in the lateral endosperm of the transgenic seeds 10 min after imbibition. An activity test indicated increased activity of endo-beta-mannanase in the transgenic lines relative to the control line in all seed parts, during the first 20 h of imbibition. However, overexpression of LeMAN3 in transgenic seeds inhibited seed germination at both optimal and suboptimal temperatures. Detailed RT-PCR analyses revealed the transcription patterns of the genes encoding the various mannanase isoforms, and indicated a delay in LeMAN2 transcription in the endosperm cap of the transgenic seeds. Interestingly, tissue-print assays indicated similar mannanase activity in the micropylar areas for both transgenic and control seeds. These results indicate that overexpression of active endo-beta-mannanase in the endosperm cap is not sufficient to enable hydrolysis of the cell walls or to promote germination of tomato seeds. Cell-wall hydrolysis in these endosperm cells is under tight control and requires the specific activity of LeMAN2.

  4. Spondylodiscite granulomateuse: surtout la tuberculose mais ne pas omettre le lymphome

    PubMed Central

    Zinebi, Ali; Rkiouak, Adil; Akhouad, Yousef; Reggad, Ahmed; Kasmy, Zohour; Boudlal, Mostafa; Lho, Abdelhamid Nait; Rabhi, Moncef; Sinaa, Mohamed; Ennibi, Khalid; Chaari, Jilali

    2016-01-01

    Les douleurs lombaires relèvent d'étiologies multiples dont le diagnostic peut être source de grandes difficultés. Le lymphome rachidien primitif est rare et son diagnostic nécessite une biopsie souvent scanoguidée. Un homme de 30 ans, était hospitalisé pour lombalgies inflammatoires évoluant dans un contexte d'altération de l'état général avec à l'examen des douleurs à la palpation des apophyses épineux L2L3, sans syndrome tumoral périphérique. Le bilan biologique montrait un syndrome inflammatoire. Le bilan morphologique était en faveur d'une spondylodiscite. La première biopsie montrait une ostéite granulomateuse. L'aggravation clinique et radiologique sous anti bacillaire a mené à reconsidérer le diagnostic et la deuxième biopsie confirme le diagnostic du lymphome. Le diagnostic de tuberculose osseuse en particulier vertébrale nécessite une confirmation bactériologique et ou histologique pour ne pas méconnaître un lymphome osseux primitif. PMID:28292061

  5. Le nodule nécrotique solitaire du foie: à propos de deux cas

    PubMed Central

    Mzoughi, Zeineb; Slama, Sana Ben; Bacha, Dhouha; Romdhane, Haifa; Bayar, Rached; Sassi, Asma; Lahmar, Ahlem

    2016-01-01

    Les lésions hépatiques nodulaires sont majoritairement tumorales. Le nodule nécrotique solitire du foie est rare. Le diagnostic preopératoire est difficile. Il s'agit d'une femme âgée de 43 ans qui était opérée d'un adénocarcinome du rectum métastatique au foie opéré. Le scanner abdominal de surveillance a révélé un nodule hépatique d'allure métastatique. Le second cas est celui d'un homme de 56 ans, admis pour cholécystectomie avec découverte per-opératoire d'un nodule hépatique. Dans les deux cas, le nodule hépatique était sous capsulaire et a été réséqué. L'examen anatomopathologique posait le diagnostic de nodule nécrotique solitaire du foie. Le nodule nécrotique non spécifique du foie est une lésion qui doit être évoquée, même dans un contexte néoplasique. Une caractérisation par l'imagerie et une ponction biopsie des lésions hépatiques peut être utile. PMID:28292145

  6. Correlation analysis of human embryo Le(Y) glycan antigen expression and embryo quality.

    PubMed

    Gu, Juan; Sui, Linlin; Ma, Yanni; Guo, Zhenzhen; Zhang, Man; Zhu, Chenyang; Cai, Zhu; Kong, Ying

    2017-07-01

    This study assessed the feasibility of using Le(Y) glycan secretion level in human embryos as a method of judging embryo quality. Embryo culture media from patients receiving in vitro fertilization-embryo transfer was collected, and quality scores of embryos were recorded. Secretions of Le(Y) in the culture media in different development stages (from 4-cell to 10-cell), embryos in the same development stage of the same patients (8-cell/I) and embryos in the same development stage of different patients (8-cell/I) were examined by dot-blot. Embryos were divided into a hypersecretion group and hyposecretion group, based on their Le(Y) secretion level. The embryo quality was evaluated by clinical observations, the number which developed to D3 cell stage and the number of successful embryo transplantations. Le(Y) secretion increased as embryos developed from 4-cell to 10-cell (P<0.05); secretion of Le(Y) of 8/I is not identical; development speed of embryos with different secretion level of Le(Y) was also different. The number of embryos which developed to 6-cell or higher was 82.2% in the Le(Y) hypersecretion group but only 60% in the hyposecretion group. The rate of successful transplantation was significantly higher in the hypersecretion group (71.1 vs. 40%). In conclusion, Le(Y) glycan secretion level in human embryos is closely related to embryo quality. Le(Y) may become a useful measure to evaluate embryo quality in the future.

  7. Speech Processing in Realistic Battlefield Environments (Le Traitement de la Parole en Environnement de Combat Realiste)

    DTIC Science & Technology

    2009-04-01

    parole et du langage multilingue commence à être reconnue comme un enjeu important par les organisations internationales civiles et militaires. Par...sur le développement et l’évaluation des applications multilingues de la parole et du langage . Pour stimuler la recherche et l’évaluation, le Groupe...Opérationnel de Recherche sur la Parole et le Langage (IST-031/TG-013) de l’OTAN a collationné des données vocales en environnement de combat. Ces

  8. [Prevalence of Giardia duodenalis assemblage B in humans in Zaragoza and León, Spain].

    PubMed

    Goñi, Pilar; Aldana, Débora Esmeralda; Clavel, Antonio; Seral, Cristina; Remacha, María Antonia; Castillo, Francisco Javier

    2010-12-01

    To study Giardia duodenalis assemblages circulating in the health areas of two hospitals in Zaragoza and León (Spain). A total of 211 stool samples with Giardia were genotyped by PCR of the tpi gene. Assemblage B was the most prevalent, both in Zaragoza (84,7%) and León (95,1%). The remaining isolates were identified as AII+B. We detected the spread of G. duodenalis assemblage B in Zaragoza and in León, with an increase in its prevalence in Zaragoza compared to previous studies. Copyright © 2009 Elsevier España, S.L. All rights reserved.

  9. Characterizing the secondary hydration shell on hydrated myoglobin, hemoglobin, and lysozyme powders by its vitrification behavior on cooling and its calorimetric glass-->liquid transition and crystallization behavior on reheating.

    PubMed Central

    Sartor, G; Hallbrucker, A; Mayer, E

    1995-01-01

    For hydrated metmyoglobin, methemoglobin, and lysozyme powders, the freezable water fraction of between approximately 0.3-0.4 g water/g protein up to approximately 0.7-0.8 g water/g protein has been fully vitrified by cooling at rates up to approximately 1500 K min-1 and the influence of cooling rate characterized by x-ray diffractograms. This vitreous but freezable water fraction started to crystallize at approximately 210 K to cubic ice and at approximately 240 K to hexagonal ice. Measurements by differential scanning calorimetry have shown that this vitreous but freezable water fraction undergoes, on reheating at a rate of 30 K min-1, a glass-->liquid transition with an onset temperature of between approximately 164 and approximately 174 K, with a width of between approximately 9 and approximately 16 degrees and an increase in heat capacity of between approximately 20 and approximately 40 J K-1 (mol of freezable water)-1 but that the glass transition disappears upon crystallization of the freezable water. These calorimetric features are similar to those of water imbibed in the pores of a synthetic hydrogel but very different from those of glassy bulk water. The difference to glassy bulk water's properties is attributed to hydrophilic interaction and H-bonding of the macromolecules' segments with the freezable water fraction, which thereby becomes dynamically modified. Abrupt increase in minimal or critical cooling rate necessary for complete vitrification is observed at approximately 0.7-0.8 g water/g protein, which is attributed to an abrupt increase of water's mobility, and it is remarkably close to the threshold value of water's mobility on a hydrated protein reported by Kimmich et al. (1990, Biophys. J. 58:1183). The hydration level of approximately 0.7-0.8 g water/g protein is approximately that necessary for completing the secondary hydration shell. PMID:8599674

  10. A calorimetric and spectroscopic comparison of the effects of cholesterol and its sulfur-containing analogs thiocholesterol and cholesterol sulfate on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine bilayer membranes.

    PubMed

    Benesch, Matthew G K; Lewis, Ruthven N A H; McElhaney, Ronald N

    2016-02-01

    We performed differential scanning calorimetric (DSC) and Fourier transform infrared (FTIR) spectroscopic studies of the effects of cholesterol (Chol), thiocholesterol (tChol) and cholesterol sulfate (CholS) on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine (DPPC) bilayer membranes. Our DSC results indicate that Chol and tChol incorporation produce small temperature increases in the main phase transition broad component while CholS markedly decreases it, but Chol decreases cooperativity and enthalpy more strongly than CholS and especially tChol. Hence, Chol and tChol thermally stabilize fluid DPPC bilayer sterol-rich domains while CholS markedly destabilizes them, and CholS and particularly tChol are less miscible in such domains. Our FTIR spectroscopic results indicate that Chol incorporation increases the rotational conformational order of fluid DPPC bilayers to a slightly and somewhat greater degree than tChol and CholS, respectively, consistent with our DSC findings. Also, Chol and CholS produce comparable degrees of H-bonding (hydration) of the DPPC ester carbonyls in fluid bilayers, whereas tChol increases H-bonding. At low temperatures, Chol is fully soluble in gel-state DPPC bilayers, whereas tChol and CholS are not. Thus tChol and CholS incorporation can produce considerably different effects on DPPC bilayers. In particular, the tChol thiol group markedly reduces its lateral miscibility and increases DPPC carbonyl H-bonding without significantly affecting the other characteristic effects of Chol itself, while the CholS sulfate group significantly reduces its ability to thermally stabilize and order fluid DPPC membranes. This latter result suggests that the molecular basis for the purported ability of CholS to "stabilize" various biological membranes should be re-examined.

  11. Thermotropic phase behavior of model membranes composed of phosphatidylcholines containing cis-monounsaturated acyl chain homologues of oleic acid: differential scanning calorimetric and /sup 31/P NMR spectroscopic studies

    SciTech Connect

    Lewis, R.N.A.H.; Sykes, B.D.; McElhaney, R.N.

    1988-02-09

    The thermotropic phase behavior of dioleoylphosphatidylcholine and six of its longer chain homologues was studied by differential scanning calorimetry and /sup 31/P nuclear magnetic resonance (NMR) spectroscopy. Aqueous dispersions of these compounds all exhibit a single endotherm upon heating but upon cooling exhibit at least two exotherms, both of which occur at temperatures lower than those of their heating endotherm. The single transition observed upon heating was shown by /sup 31/P NMR spectroscopy to be a net conversion from a condensed, subgel-like phase (L/sub c/ phase) to the liquid-crystalline state. Aqueous ethylene glycol dispersions of these compounds also exhibit single endotherms upon heating and cooling exotherms centered at temperatures lower than those of their corresponding heating endotherm. However, the behavior of the aqueous ethylene glycol dispersions differs with respect to their transition temperatures and enthalpies as well as the extent of undercooling observed, and there is some evidence of discontinuities in the cooling behavior of the odd- and even-numbered members of the homologous series. Like the aqueous dispersions, /sup 31/P NMR spectroscopy also shows that the calorimetric events observed in aqueous ethylene glycol involve net interconversions between an L/sub c/-like phase and the liquid-crystalline state. These results demonstrate that although the presence of a cis double bond can perturb the solid-state packing of the acyl chains, its presence does not preclude the formation of highly ordered subgel-like phases in lipid bilayers. In the particular case of these unsaturated phosphatidylcholines, the formation of the subgel phases is more kinetically favorable than is the case with their saturated n-acyl counterparts.

  12. Portevin-Le Chatelier effect and Tsallis nonextensive statistics

    NASA Astrophysics Data System (ADS)

    Iliopoulos, A. C.; Nikolaidis, N. S.; Aifantis, E. C.

    2015-11-01

    In this paper, we estimate Tsallis' entropic index q ≡qstat (stat denotes stationary states) for various stress serration time series of Cu-15%Al alloys corresponding to different deformation temperatures and types (A, B, C) of Portevin-Le Chatelier (PLC) bands. Tsallis statistical analysis is also conducted on experimental data derived from correlation diagrams focusing on PLC type C bands' spatial organization at the surface of various specimens. The results concerning the stress serrations analysis reveal the non-Gaussian (Tsallis q-Gaussian), nonextensive, sub-additive, character of the underlying dynamics of the PLC type-A bands (q > 1) indicating dynamics at the edge of chaos, with global long range correlations and power law scaling. Similarly, for PLC type B bands, a Tsallis q-Gaussian, non-extensive, super-additive, statistical profile was found with q < 1, while for the PLC type C bands, a near Boltzmann-Gibbs (BG) statistical character was verified indicating Gaussian dynamics with short (weak) range correlations. Finally, Tsallis q-index for the spatial data of PLC type C bands was found above unity (q > 1) indicating that type C bands are not randomly nucleated in the specimen (e.g. yielding a Gaussian distribution) but there exist spatial coupling and long range deformation correlations in the PLC type C bands spatial localization.

  13. LeFort III advancement with and without osteogenesis distraction.

    PubMed

    Iannetti, Giorgio; Fadda, Teresa; Agrillo, Alessandro; Poladas, Giulio; Iannetti, G; Filiaci, Fabio

    2006-05-01

    The LeFort III osteotomy is the surgical treatment performed in patients with mid-facial retrusions in craniofacial dysostoses such as Crouzon, Apert, Pfeiffer syndromes, etc. The first authors to report the accomplishment of this osteotomy were Gillies and Harrison in 1951, this technique was then resumed and improved by Tessier in 1967, who made five different variants mainly regarding the typology of the osteotomy concerning the lateral wall of the orbit. Recently, distraction techniques have been applied to the upper mid-face which foresees a gradual advancement of the mid-face through the osteogenetic distraction procedure. The purpose of this retrospective clinical outcome study is to evaluate and compare the two different surgical techniques through the experience acquired during the treatment of 15 cases of craniofacial dysostoses from 1990-2005, and through international literature. The standard surgery technique was performed in 5 of these patients, whereas the osteogenetic distraction technique was performed in the remaining 10. All patients were studied preoperatively through the acquisition of photographic images, cephalometric analysis of the skull, and the study on plaster models of the occlusion of the dental arches. The instrumental exams required before surgery are the following: telecranium X-rays in two projections, orthopanoramic X-rays, CT. The results of this study indicate that the osteodistraction technique represents the choice treatment in severe retrusions of the mid-face while the traditional surgical technique remains indicated in adult patients that are in need of moderate advancements.

  14. [Mr. Wang Le-ting: a master of acupuncture].

    PubMed

    Niu, Xue-Song; Wang, Fan

    2012-11-01

    Mr. WANG Le-ting attaches great importance to accurate differentiation of syndromes, strict selection of acupoints, technique and direction of needle insertion, clear reinforcing and reducing methods after the appearance of needling sensations, proper opportunities of manipulations as well as needle withdrawal techniques, and reasonable application of acupuncture and moxibustion respectively. The above mentioned principles are known as his "5 agreements". He emphasizes that the selection of acupoints should be "in accordance with both the meridians and the accurate location of the points", and "needling sensation is necessary for each point". He holds that the back-shu points of the five-zang organs and Geshu (BL 17) can be adopted for patient with deficiency of qi, blood, yin and yang. In the aspect of acupoint theory, he insists the accurate location of Xuanzhong (GB 39). He also adjusts the locations of Huatuo Jiaji (EX-B 2) points, and finds the location of the new Dubi (ST 35). For easier applications, he divides the functions of acupoints into different schools of qi, blood, cold, heat, deficiency, excess, wind and dampness. And 41 combinations of acupoints are also invented as innovation. He is always strict to his students, instructing and influencing them by his own words and deeds. He is always conscientious and meticulous, which benefit immensely his followers, and remains a lot of precious experiences for the later generations.

  15. [Effects of Le-Fort-I-Osteotomy on nasalance scores].

    PubMed

    Zemann, Wolfgang; Feichtinger, Matthias; Santler, Gert; Kärcher, Hans

    2006-07-01

    Nasalance represents a measure of the relative amount of oral and nasal acoustic energy produced by a speaker. Literature shows changes in nasalance after surgery of the oropharynx. The aim of this prospective study was to evaluate the outcome of speech and nasalance scores after Le-Fort-I-Osteotomy. A total of 20 individuals with normal speech development were examined preoperatively and 6 weeks postoperatively with the Nasometer 6200 (Kay-Elemetrics, USA) after bimaxillary surgery. The tone materials used comprised the standardized text passage: "Ein Kindergeburtstag", the vowels: /a/, /e/, /i/, /o/, /u/ and a syllable repetition subtest. All patients showed changes in nasalance scores 6 weeks postoperatively. There were no significant changes reading the standard text. The syllable repetition test showed significant changes for repetition of "ma ma ma" and "na na na" (p=0,003, respectively p=0,033). Intonation of the vowel /a/1 also revealed significant changes regarding the pre- and postoperative values (p=0,006). However, the obtained values had no significant impact on the nasality characteristics of speech. This study confirms that maxillary osteotomies can result in significant changes of nasalance scores. However these changes do not have any impact on normal speech and voice.

  16. LeMAPK1, LeMAPK2, and LeMAPK3 are associated with nitric oxide-induced defense response against Botrytis cinerea in the Lycopersicon esculentum fruit.

    PubMed

    Zheng, Yanyan; Hong, Hui; Chen, Lin; Li, Jingyuan; Sheng, Jiping; Shen, Lin

    2014-02-12

    Nitric oxide (NO) and mitogen-activated protein kinases (MAPKs) are signal molecules involved in the disease resistance of plants. To investigate the role of tomato MAPKs in the NO-mediated defense response, mature green tomatoes (Lycopersicon esculentum Mill. cv. Qian-xi) were treated with a MAPKs inhibitor (1,4-diamino-2,3-dicyano-1,4-bis(o-amino-phenylmercapto) butadiene (U0126)), NO donor sodium nitroprusside (SNP), and SNP plus U0126. Treatment with U0126 increased the incidence of disease and size of lesion areas in the tomato fruits after being inoculated with Botrytis cinerea. NO enhanced the resistance of the tomato fruits against Botrytis cinerea invasion and the activities of nitric oxide synthase, Chitinase, β-1,3-glucanase, polyphenol oxidase, and phenylalanine ammonia-lyase. However, the effects of NO on disease resistance were weakened by the MAPKs inhibitor. Meanwhile, the relative expression of LeMAPK1, LeMAPK2, and LeMAPK3 in the (SNP + U0126)-treated fruits was lower than that in the SNP-treated fruits. The results suggest that LeMAPK1/2/3 are involved in NO-induced disease resistance of tomato fruits against Botrytis cinerea.

  17. Overexpression of the tomato pollen receptor kinase LePRK1 rewires pollen tube growth to a blebbing mode.

    PubMed

    Gui, Cai-Ping; Dong, Xin; Liu, Hai-Kuan; Huang, Wei-Jie; Zhang, Dong; Wang, Shu-Jie; Barberini, María Laura; Gao, Xiao-Yan; Muschietti, Jorge; McCormick, Sheila; Tang, Wei-Hua

    2014-09-01

    The tubular growth of a pollen tube cell is crucial for the sexual reproduction of flowering plants. LePRK1 is a pollen-specific and plasma membrane-localized receptor-like kinase from tomato (Solanum lycopersicum). LePRK1 interacts with another receptor, LePRK2, and with KINASE PARTNER PROTEIN (KPP), a Rop guanine nucleotide exchange factor. Here, we show that pollen tubes overexpressing LePRK1 or a truncated LePRK1 lacking its extracellular domain (LePRK1ΔECD) have enlarged tips but also extend their leading edges by producing "blebs." Coexpression of LePRK1 and tomato PLIM2a, an actin bundling protein that interacts with KPP in a Ca(2+)-responsive manner, suppressed these LePRK1 overexpression phenotypes, whereas pollen tubes coexpressing KPP, LePRK1, and PLIM2a resumed the blebbing growth mode. We conclude that overexpression of LePRK1 or LePRK1ΔECD rewires pollen tube growth to a blebbing mode, through KPP- and PLIM2a-mediated bundling of actin filaments from tip plasma membranes. Arabidopsis thaliana pollen tubes expressing LePRK1ΔECD also grew by blebbing. Our results exposed a hidden capability of the pollen tube cell: upon overexpression of a single membrane-localized molecule, LePRK1 or LePRK1ΔECD, it can switch to an alternative mechanism for extension of the leading edge that is analogous to the blebbing growth mode reported for Dictyostelium and for Drosophila melanogaster stem cells. © 2014 American Society of Plant Biologists. All rights reserved.

  18. General parameter relations for the Shinnar-Le Roux pulse design algorithm.

    PubMed

    Lee, Kuan J

    2007-06-01

    The magnetization ripple amplitudes from a pulse designed by the Shinnar-Le Roux algorithm are a non-linear function of the Shinnar-Le Roux A and B polynomial ripples. In this paper, the method of Pauly et al. [J. Pauly, P. Le Roux, D. Nishimura, A. Macovski, Parameter relations for the Shinnar-Le Roux selective excitation pulse design algorithm, IEEE Transactions on Medical Imaging 10 (1991) 56-65.] has been extended to derive more general parameter relations. These relations can be used for cases outside the five classes considered by Pauly et al., in particular excitation pulses for flip angles that are not small or 90 degrees. Use of the new relations, together with an iterative procedure to obtain polynomials with the specified ripples from the Parks-McClellan algorithm, are shown to give simulated slice profiles that have the desired ripple amplitudes.

  19. Modified versus classic alar base sutures after LeFort I osteotomy: a systematic review.

    PubMed

    Liu, Xianwen; Zhu, Songsong; Hu, Jing

    2014-01-01

    The purpose of this systematic review is to evaluate the efficacy of a new modified alar base cinch suture by comparing it with the commonly used classic alar base suture after LeFort I osteotomy. A comprehensive search strategy was performed to include interventional studies involving the comparisons of alar base suturing methods after LeFort I osteotomy. Data analyses were conducted using the random-effects model. Three studies with 146 participants undergoing LeFort I maxillary osteotomy were included in this review. The results showed that, compared with the classic method, both modified transseptal alar base suture and modified reinsertion sutures significantly decreased postoperative alar and alar base widening. The modified alar base cinch suture was more effective than the classic alar base suture in maintaining preoperative alar and alar base width after LeFort I osteotomy. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. 5. Former P&LE tracks (now CSXT) adjacent to trestle towards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Former P&LE tracks (now CSXT) adjacent to trestle towards west. - Monongahela Connecting Railroad Company, Y Trestle, South side of Monongahela River between Thirty-fourth & Twenty-ninth Streets, Pittsburgh, Allegheny County, PA

  1. Landau and Lifshitz' formulation of Le Chatelier's principle: an insight into symbiosis?

    PubMed

    Halabi, T

    2013-12-01

    A correspondence allows application of Landau and Lifshitz' formulation of Le Chatelier's principle from statistical physics to a simple 2-D model of biological symbiosis. The insight: symbionts stabilize the occupation of narrow peaks on fitness landscape.

  2. A Multistep Equilibria-Redox-Complexation Demonstration to Illustrate Le Chatelier's Principle.

    ERIC Educational Resources Information Center

    Berger, Tomas G.; Mellon, Edward K.

    1996-01-01

    Describes a process that can be used to illustrate a number of chemical principles including Le Chatelier's principle, redox chemistry, equilibria versus steady state situations, and solubility of species. (JRH)

  3. An Overhead Demonstration of Some Descriptive Chemistry of the Halogens and LeChatelier's Principle.

    ERIC Educational Resources Information Center

    Hansen, Robert C.

    1988-01-01

    Describes a demonstration procedure using controlled reduction potentials to predict observed color changes which are then experimentally verified. Demonstrates the usefulness of this procedure in helping students understand LeChatelier's principle and the solubilit rule "like dissolves like." (CW)

  4. The Potassium-Argon Laser Experiment (KArLE): In Situ Geochronology for Planetary Missions

    NASA Astrophysics Data System (ADS)

    Cohen, B. A.

    2016-10-01

    KArLE is intended to yield in situ geochronology data and enhance functionality of existing flight instruments using flight hardware that would be reliable, reconfigurable and adaptable to multiple partner instruments and mission architectures.

  5. An Overhead Demonstration of Some Descriptive Chemistry of the Halogens and LeChatelier's Principle.

    ERIC Educational Resources Information Center

    Hansen, Robert C.

    1988-01-01

    Describes a demonstration procedure using controlled reduction potentials to predict observed color changes which are then experimentally verified. Demonstrates the usefulness of this procedure in helping students understand LeChatelier's principle and the solubilit rule "like dissolves like." (CW)

  6. 3. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 NORTHEAST ELEVATION. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  7. 10. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 MANTEL (NOT ORIGINAL) SOUTHEAST PARLOR. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  8. 14. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 INTERIOR DETAIL, SOUTHEAST BEDROOM. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  9. 7. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 SOUTH (FRONT) ELEVATION. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  10. 4. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 SOUTHWEST ELEVATION. - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  11. Comparison of the severity of bilateral Le Fort injuries in isolated midface trauma.

    PubMed

    Bagheri, Shahrokh C; Holmgren, Eric; Kademani, Deepak; Hommer, Louis; Bell, R Bryan; Potter, Bryce E; Dierks, Eric J

    2005-08-01

    The Le Fort classification pattern established in 1901 by the French surgeon Rene Le Fort is commonly used in describing midface fractures. This frequently used classification system is based on predictable patterns of midface fractures initially described for blunt trauma. The purpose of this study was to compare the profile and outcome of patients with isolated bilateral Le Fort I, II, and III fractures. All patients presenting to the emergency department (ED) at Legacy Emanuel Hospital (Level I trauma center) in Portland, OR, between December 1990 and December 2003 with isolated bilateral Le Fort I, II, or III fractures with or without concomitant nonfacial injuries were identified retrospectively using the Hospital Trauma Registry. Patients were classified into study groups I (n = 22), II (n = 22), or III (n = 23) corresponding to the Le Fort classification, respectively. Sixty-seven patients had a diagnosis of isolated bilateral Le Fort I, II, or III fracture. The average Injury Severity Score (ISS) and hospital length of stay were 18.8 +/- 8.9 and 9.5 +/- 11.9 days, respectively. Blood alcohol was detected in 19 patients. Sixty-four injuries (95.5%) were secondary to blunt trauma, and the remaining 3 (4.5%), penetrating injuries. More than half of the patients (n = 35, 52.2%) were admitted to the intensive care unit (ICU), 18 patients (26.8%) were transferred to the hospital trauma ward from the ED, and 14 patients (20.9%) were taken directly to the operating room. Fifteen (22.4%) patients required a tracheostomy secondary to their maxillofacial injuries. A statistically significant difference in the ISS was detected between patients with Le Fort I versus those with II or III injuries ( P < .0001). Patients with Le Fort II or III fractures had a significantly higher probability of ICU admission or immediate operative intervention. Ten patients (43.5%) with Le Fort III injuries required tracheostomy versus 3 patients (13.6%) with Le Fort I, and 2 patients (9

  12. Le volvulus gastrique idiopathique aigu: à propos d'une nouvelle observation

    PubMed Central

    Abdelilah, Mouhsine; Jihad, Anzaoui; Rachid, Bouchentouf

    2013-01-01

    Le volvulus gastrique est une rotation anormale de l'estomac autour de son axe. La forme aiguë constitue une urgence chirurgicale. Le diagnostic est souvent retardé en raison d'une symptomatologie fréquemment non spécifique. Des signes respiratoires tels la dyspnée et le hoquet peuvent révéler cette pathologie. Les auteurs rapportent une nouvelle observation de volvulus gastrique aigu chez un adolescent de 17 ans, diagnostiqué par la tomodensitométrie, et confirmé par une intervention chirurgicale. Le traitement est chirurgical et consiste à détordre et fixer l'estomac pour prévenir la récidive. PMID:23503200

  13. Le schwannome malin du nerf grand sciatique chez l'enfant

    PubMed Central

    Lechqar, Maryem; Elbiache, Imad; Atarraf, Karima; Bouabdellah, Youssef; Afifi, My Abderahman

    2012-01-01

    Le schwannome malin est une tumeur très rare chez l'enfant (1 à 2% des tumeurs des tissus mous), elle se développe au dépend des cellules de schwanne. Dans ce travail, les auteurs rapportent un cas de schwannome malin développé au dépend du nerf grand sciatique. La radiographie de la cuisse de face et de profil était normale. L'imagerie par résonance magnétique a identifié une lésion le long du trajet du nerf grand sciatique. La tumeur a été réséquée en totalité emportant le nerf grand sciatique. L'examen anatomo-pathologique a confirmé le diagnostic. PMID:23133710

  14. Facteurs de risque de l'infection par le VIH dans le district de santé de Meyomessala au Cameroun

    PubMed Central

    Mbopi-Keou, Francois-Xavier; Nguefack-Tsague, Georges; Kalla, Ginette Claude Mireille; Abessolo, Stéphanie Abo'o; Angwafo, Fru; Muna, Walinjom

    2014-01-01

    Introduction L'objectif de ce travail était de déterminer les facteurs de risque de l'infection par le VIH dans le district de santé de Meyomessala (Région du Sud) au Cameroun. Méthodes Il s'agissait d'une étude transversale, descriptive et analytique qui s'est déroulée de Février à Mai 2011. Pour cette étude, nous avons obtenu une clairance éthique. Résultats L’échantillon était constitué de 315 participants dont 181 (57,46%) hommes et 134 (42,54%) femmes. L’âge moyen était de 24,5±8ans (extrême: 15-45ans). Quarante personnes (40) étaient séropositifs, soit une prévalence de l'infection par le VIH de 12,7%. Cette prévalence augmentait significativement (p = 0) avec le nombre de partenaires occasionnels au cours des douze derniers mois, allant de 2,7% chez ceux n'ayant eu aucun partenaire occasionnel à 21,25% chez ceux ayant plus de trois partenaires occasionnels (RC = 9,72; IC = 1,27-74,14; P = 0,03). le fait d’être âgé entre 20 et 24 ans (RC = 4,88; IC = 1,74-13,67; p = 0), avoir plus de trois partenaires sexuels au cours des douze derniers mois (RC = 9,72; IC = 1,27-74,14; p = 0,03), avoir les rapports sexuels avec les prostitués (RC = 2,86; IC = 1,42-5,76; p = 0), avoir eu le chlamydia (RC = 3,00; IC = 1,07-8,39; p = 0,04), avoir eu la syphilis (RC = 3,35; IC = 1,57-7,14; p = 0), avoir des avantages sociaux lors du premier rapport sexuel (RC = 2,57; IC = 1,03-6,43; p = 0,04) constituaient des potentiels facteurs de risque du VIH. Conclusion Il apparait urgent d'intensifier les campagnes de sensibilisation au risque d'infection par le VIH et les maladies sexuellement transmissibles dans le district de santé de Meyomessala PMID:25419299

  15. Genome Sequence of Novosphingobium lindaniclasticum LE124T, Isolated from a Hexachlorocyclohexane Dumpsite

    PubMed Central

    Saxena, Anjali; Nayyar, Namita; Sangwan, Naseer; Kumari, Rashmi; Khurana, J. P.

    2013-01-01

    Novosphingobium lindaniclasticum LE124T is a hexachlorocyclohexane (HCH)-degrading bacterium isolated from a high-dosage-point HCH dumpsite (450 mg HCH/g soil) located in Lucknow, India (27°00′N and 81°09′E). Here, we present the annotated draft genome sequence of strain LE124T, which has an estimated size of 4.86 Mb and is comprised of 4,566 coding sequences. PMID:24029761

  16. LeČOns Sur Les Ondes De Gravité Des Fluides Incompressibles

    NASA Astrophysics Data System (ADS)

    van den Dungen, F. H.

    Le 3 Janvier 1814 au moment où les Alliés franchissant le Rhin allaient entamer la campagne de France, la classe des Sciences de l'Institut de France proposait comme sujet du grand prix de mathématique à décerner en Janvier 1816 la question suivante: "La théorie de la propagation des ondes à la surface d'un fluide pesant d'une profondeur infinie".

  17. Trends in Le Fort Fractures at a South American Trauma Care Center: Characteristics and Management.

    PubMed

    Oliveira-Campos, Gustavo Halak; Lauriti, Leandro; Yamamoto, Marcos Kazuo; Júnior, Rubens Camino; Luz, João Gualberto C

    2016-03-01

    To assess the trends in Le Fort (maxillary) fractures in patients seen at a South American trauma care center based on the characteristics and management of these. Of all patients with facial fractures seen at a trauma hospital during a six-year period, 50 (6.6 %) presented with Le Fort fractures. Medical charts were reviewed for characteristics presented and management performed. To improve the analyses, computed tomography and intraoperative findings were used. Statistical analyses involved descriptive statistics and the likelihood ratio test. The fractures were Le Fort II (52 %), Le Fort I (22 %), Le Fort type-associated (20 %) and Le Fort III (6 %). Male patients (90 %) in their third decade of life (38 %) were more frequent (p = 0.022). Traffic accidents (56 %) were the major etiologic factor (p = 0.048). There were 1.4 additional facial fractures per patient, with predominance of zygoma fractures (36.5 %). Most of the cases were managed by open reduction (60 %) (p = 0.015) with the subciliary approach (42.7 %) (p = 0.001). The 1.5-mm system was the most used fixation and the zygomaticomaxillary suture the most frequent location (p = 0.001). the most common patient with a Le Fort fracture is an adult male, with a Le Fort II fracture due to a traffic accident requiring surgical fixation on zygomaticomaxillary suture.

  18. Facteurs déterminants le regret après ligature tubaire

    PubMed Central

    Boufettal, Houssine; Mahdaoui, Sakher; Samouh, Naïma

    2014-01-01

    Introduction La ligature tubaire peut générer regret. Le but de cette étude est d’étudier le vécu après la stérilisation ainsi que le regret et ses facteurs de risque. Méthodes Il s'agit d'une étude rétrospective chez 52 femmes stérilisées entre 2004 et 2010. Résultats Vingt cinq (48%) femmes avaient regretté la réalisation de la ligature tubaire. La moyenne d’âge était de 40,5 ans. Le temps consacré aux explications était très court dans tous les cas. Trois quart des femmes n’était pas au courant des complications de la ligature tubaire. Le regret était dû au facteur religieux (23%), aux algies pelviennes (11,5%), au désir d'autres enfants (9,6%) ou à la prise de connaissance d'autres moyens contraceptifs (3,9%). Conclusion Un certains nombre de facteurs de risque de regret de la ligature tubaire sont retrouvés dans la littérature, comme dans notre série, dont l’âge, le désir de procréer, l'information incomplète, le délai de réflexion et le facteur religieux. PMID:25309644

  19. STIL, a peculiar molecule from styles, specifically dephosphorylates the pollen receptor kinase LePRK2 and stimulates pollen tube growth in vitro

    USDA-ARS?s Scientific Manuscript database

    BACKGROUND: LePRK1 and LePRK2 are two pollen receptor kinases localized to the plasma membrane, where they are present in a high molecular weight complex (LePRK complex). LePRK2 is phosphorylated in mature and germinated pollen, but is dephosphorylated when pollen membranes are incubated with tomato...

  20. Architectural Kansei of ‘Wall’ in The Façade Design by Le Corbusier

    NASA Astrophysics Data System (ADS)

    Sendai, Shoichiro

    The purpose of this paper is to discuss the modern architect Le Corbusier's architectural Kansei (sensibility) on wall in site environment through the analysis of his façade design, using Œuvres complètes (1910-1965, 8 vols., Les éditions d'architecture, Artemis, Zurich) and Le Corbusier Archives (1982-1984, 32 vols., Garland Publishing, Inc. and Fondation Le Corbusier, New York, London, Paris). At first, I arrange five façade types, according to the explanation by Le Corbusier ; ‘fenêtre en longueur (strip window)’, ‘pan de verre (glass wall)’, ‘brise-soleil (sun-breaker)’, ‘loggia’ and ‘claustra’. Through the analysis of the relationship between these types and the design process of each building, we find that Le Corbusier's façade design includes the affirmation and the negation of the ‘wall’ at the same time. In fact, the nature of façade modification during design process is divers: increase in transparency, decrease in transparency and spatialization of façade. That means, Le Corbusier studied the environmental condition by these façade types, and tried to realize the phenomenal openness. This trial bases on the function of architectural Kansei as correspondence between body and environment beyond the physical design.

  1. Le Châtelier reciprocal relations and the mechanical analog

    NASA Astrophysics Data System (ADS)

    Gilmore, Robert

    1983-08-01

    Le Châtelier's principle is discussed carefully in terms of two sets of simple thermodynamic examples. The principle is then formulated quantitatively for general thermodynamic systems. The formulation is in terms of a perturbation-response matrix, the Le Châtelier matrix [L]. Le Châtelier's principle is contained in the diagonal elements of this matrix, all of which exceed one. These matrix elements describe the response of a system to a perturbation of either its extensive or intensive variables. These response ratios are inverses of each other. The Le Châtelier matrix is symmetric, so that a new set of thermodynamic reciprocal relations is derived. This quantitative formulation is illustrated by a single simple example which includes the original examples and shows the reciprocities among them. The assumptions underlying this new quantitative formulation of Le Châtelier's principle are general and applicable to a wide variety of nonthermodynamic systems. Le Châtelier's principle is formulated quantitatively for mechanical systems in static equilibrium, and mechanical examples of this formulation are given.

  2. SCRaMbLE generates designed combinatorial stochastic diversity in synthetic chromosomes

    PubMed Central

    Shen, Yue; Stracquadanio, Giovanni; Wang, Yun; Yang, Kun; Mitchell, Leslie A.; Xue, Yaxin; Cai, Yizhi; Chen, Tai; Dymond, Jessica S.; Kang, Kang; Gong, Jianhui; Zeng, Xiaofan; Zhang, Yongfen; Li, Yingrui; Feng, Qiang; Xu, Xun; Wang, Jun; Wang, Jian; Yang, Huanming; Boeke, Jef D.; Bader, Joel S.

    2016-01-01

    Synthetic chromosome rearrangement and modification by loxP-mediated evolution (SCRaMbLE) generates combinatorial genomic diversity through rearrangements at designed recombinase sites. We applied SCRaMbLE to yeast synthetic chromosome arm synIXR (43 recombinase sites) and then used a computational pipeline to infer or unscramble the sequence of recombinations that created the observed genomes. Deep sequencing of 64 synIXR SCRaMbLE strains revealed 156 deletions, 89 inversions, 94 duplications, and 55 additional complex rearrangements; several duplications are consistent with a double rolling circle mechanism. Every SCRaMbLE strain was unique, validating the capability of SCRaMbLE to explore a diverse space of genomes. Rearrangements occurred exclusively at designed loxPsym sites, with no significant evidence for ectopic rearrangements or mutations involving synthetic regions, the 99% nonsynthetic nuclear genome, or the mitochondrial genome. Deletion frequencies identified genes required for viability or fast growth. Replacement of 3′ UTR by non-UTR sequence had surprisingly little effect on fitness. SCRaMbLE generates genome diversity in designated regions, reveals fitness constraints, and should scale to simultaneous evolution of multiple synthetic chromosomes. PMID:26566658

  3. Rectified brownian transport in corrugated channels: Fractional brownian motion and Lévy flights.

    PubMed

    Ai, Bao-quan; Shao, Zhi-gang; Zhong, Wei-rong

    2012-11-07

    We study fractional brownian motion and Lévy flights in periodic corrugated channels without any external driving forces. From numerical simulations, we find that both fractional gaussian noise and Lévy-stable noise in asymmetric corrugated channels can break thermodynamical equilibrium and induce directed transport. The rectified mechanisms for fractional brownian motion and Lévy flights are different. The former is caused by non-uniform spectral distribution (low or high frequencies) of fractional gaussian noise, while the latter is due to the nonthermal character (occasional long jumps) of the Lévy-stable noise. For fractional brownian motion, average velocity increases with the Hurst exponent for the persistent case, while for the antipersistent case there exists an optimal value of Hurst exponent at which average velocity takes its maximal value. For Lévy flights, the group velocity decreases monotonically as the Lévy index increases. In addition, for both cases, the optimized periodicity and radius at the bottleneck can facilitate the directed transport. Our results could be implemented in constrained structures with narrow channels and pores where the particles undergo anomalous diffusion.

  4. Intrication de deux atomes en utilisant le blocage de Rydberg

    NASA Astrophysics Data System (ADS)

    Gaëtan, A.

    2010-12-01

    Considérons un système quantique constitué de deux sous-systèmes : on dit qu'il est dans un état intriqué s'il existe des corrélations quantiques entre les états de ces derniers. La compréhension et la mise en œuvre d'états intriqués ont de nombreuses applications (métrologie quantique, étude des systèmes fortement corrélés, traitement quantique de l'information, etc.) et constituent le contexte général de ce travail de thèse. Plus en détail, nous démontrons la réalisation d'un état intriqué de deux atomes neutres piégés indépendamment. Pour cela, nous exploitons le phénomène de blocage de Rydberg : lorsqu'on essaie d'exciter simultanément deux atomes séparés de quelques micromètres vers un état de Rydberg donné, la forte interaction entre atomes de Rydberg peut empêcher cette excitation simultanée. Dans ce cas, seul un des deux atomes est excité et l'on génère ainsi des corrélations quantiques entre les états des deux atomes, c'est-à-dire de l'intrication. Dans notre expérience, deux atomes de 87Rb dans l'état fondamental 5S1/2 sont piégés chacun dans une pince optique microscopique, à une distance relative de 4 micromètres. En réalisant des transitions entre l'état 5S1/2 et l'état de Rydberg 58D3/2 par des transitions à deux photons, nous obtenons un état intriqué des deux atomes dans les sous-niveaux |5S1/2, f = 1, mf = 1> et |5S1/2, f = 2, mf = 2>. Afin de quantifier l'intrication, nous mesurons la fidélité par rapport à l'état-cible en réalisant des transitions Raman entre ces deux sous-niveaux. La fidélité des paires d'atomes présentes à la fin de l'expérience est supérieure à la valeur seuil de 0,5, ce qui prouve la création d'un état intriqué.

  5. Lymphome et grossesse: le point de vue de l'obstétricien, à propos de 2 cas

    PubMed Central

    Amourak, Sarah; Alaoui, Fatimazahra Fdili; Jayi, Sofia; Bouguern, Hakima; Chaara, Hikmat; Melhouf, Moulay Abdelilah

    2014-01-01

    L'association lymphome et grossesse est une situation rare, mais non exceptionnelle, relevant de la coïncidence. Le lymphome vient en 4ème position des cancers rencontrés chez la femme enceinte, La clinique est trompeuse et inconstante, le diagnostic reste histologique et on distingue 2 types: lymphome malin hodgkinien (LMH) et le lymphome malin non hodgkinien (LMNH). Malgré le contexte de véritable urgence hématologique, la décision d'initier ou de différer le traitement est délicate, influencée par le type de lymphome, son extension et sa localisation, la répercussion organique, le degré de maturation f'tale, les risques obstétricaux et les valeurs éthiques, culturelles et religieuses de la patiente. Le traitement consiste essentiellement à une chimiothérapie. Le LH durant la grossesse est relativement moins agressif et d’évolution plus favorable que le LMNH. PMID:25883744

  6. Évolution des lignes directrices sur le traitement de la dyslipidémie

    PubMed Central

    John Bosomworth, N.

    2014-01-01

    Résumé Objectif Comprendre comment les nouvelles lignes directrices sur la prise en charge du risque cardiovasculaire publiées par l’American Heart Association et l’American College of Cardiology (AHA-ACC) peuvent être interprétées et utilisées dans le contexte canadien. Sources des données Les lignes directrices de l’AHA-ACC ont été examinées, de même que toutes les références. Des recherches indépendantes dans PubMed ont été effectuées pour inclure l’ajout aux statines d’autres antihyperlipidémiants et l’emploi de calculatrices médicales visant à aider le patient à comprendre. Message principal Les nouvelles lignes directrices de l’AHA-ACC s’appuient sur les meilleures données probantes disponibles actuellement en matière de traitement de la dyslipidémie. Cela inclut le risque cardiovasculaire (CV) sur 10 ans comme seuil thérapeutique au lieu du taux de cholestérol des lipoprotéines de faible densité, de même que l’abandon des cibles thérapeutiques de lipoprotéines de faible densité. On met de plus en plus l’accent sur les interventions alimentaires et l’exercice, avec l’amorce d’un effort pour quantifier l’effet de ces interventions. Les statines constituent la principale intervention pharmacologique, et l’ajout d’autres médicaments pour accentuer la baisse lipidique n’est plus recommandé. En ce qui concerne l’application au Canada, les tables de risque de Framingham sont plus appropriées pour évaluer le risque que les équations de cohortes regroupées utilisées aux États-Unis. Les calculatrices du risque de maladie cardiovasculaire (MCV) devraient contenir de l’information sur l’âge cardiovasculaire et devraient pouvoir illustrer le risque et les interventions de rechange afin d’aider le patient à comprendre et de favoriser la prise de décision éclairée. Conclusion L’attention sur les meilleures données probantes concernant le risque CV peut simplifier le traitement de la

  7. La plastie en rail dans le traitement des brides rétractiles du creux poplite

    PubMed Central

    Achbouk, A.; Khales, A.; Bourra, K.; Tourabi, K.; Ababou, K.; Ihrai, H.

    2011-01-01

    Summary Les Auteurs décrivent le cas d’un patient âgé de 45 ans atteint de brûlures thermiques par flammes suite à la déflagration d’une bonbonne de gaz. Les lésions initiales intéressaient les quatre membres (en particulier, le genou) et le tronc. La prise en charge initiale a consisté en une excision-greffe précoce des membres. L’évolution a été marquée par la survenue de cicatrices hypertrophiques au niveau des zones non greffées et à la bordure de la greffe ainsi que la survenue de brides rétractiles. Devant l’handicap fonctionnel engendré par la bride à cause de la limitation importante de l’extension, le patient a été admis pour cure chirurgicale. Grâce à la technique en rail décrite, le patient a pu récupérer une fonction normale du genou. Les suites ont été simples avec une durée d’hospitalisation d’un mois. Le résultat esthétique est relativement satisfaisant. La technique en rail est un moyen parmi l’arsenal thérapeutique qui permet de traiter la bride du creux poplité. Sa simplicité, sa facilité technique et son résultat satisfaisant ainsi que ses suites simples permettent de la rendre une technique très prisée dans le traitement de ce type de bride. PMID:21991240

  8. Sur la reponse en frequence du tissu nerveux dans le cortex

    NASA Astrophysics Data System (ADS)

    Bedard, Claude

    Dans cette These de Physique, nous avons etudie la dependance en frequence du champ electrique du tissu nerveux dans le cortex. Ce champ est aussi designe par "Local field Potential" LFP dans la litterature scientifique. Cette etude est fondee sur la theorie du champ electromagnetisme de Maxwell et sur de l'information tiree de la donne experimentale. Le resultat essentiel de cette These est que la grandeur enorme du temps de relaxation de Maxwell des membranes cellulaires semble etre la cause principale de la dependance en frequence des LFPs. Cette dependance en frequence causee par chaque membrane cellulaire est l'analogue d'un circuit RC ou la resistance R est la resistivite parallele d'une membrane cellulaire, et ou la capacite C est la permittivite electrique de la membrane. L'effet resultant d'un tres grand nombre de cellules donne un spectre de Fourier dont l'enveloppe est tres pres d'un signal en 1/f. Le modele physique propose dans cette These permet de lier les mesures prises a l'interieur d'une dendrite des variations de potentiel electrique a celles prises dans le liquide extracellulaire. De plus, cette These semble ouvrir la possibilite de mesurer le temps de relaxation de Maxwell des membranes cellulaires a l'aide de la mesure de la reponse en frequence du potentiel electrique extracellulaire (LFP). Enfin, cette These permet de lever le voile sur un sujet peu etudie, principalement en raison de la difficulte que represente l'etude des phenomenes electriques dans des milieux complexes comme les tissus vivants. En particulier, le probleme du filtrage frequentiel du potentiel electrique extracellulaire est une propriete fondamentale du tissu nerveux et son origine n'est pas connue.

  9. LeNRT2.3 functions in nitrate acquisition and long-distance transport in tomato.

    PubMed

    Fu, Yanlei; Yi, Hongying; Bao, Juan; Gong, Jiming

    2015-04-28

    Nitrogen plays an important role in plant growth and development. Nitrate transporters have been extensively studied in Arabidopsis, but in tomato they have not been functionally characterized. In this study, we report the functions of LeNRT2.3 in nitrate transport in tomato. Our results show that LeNRT2.3 is induced by nitrate, and mainly localizes to the plasma membranes of rhizodermal and pericycle cells in roots. Further analysis in Xenopus oocytes showed that LeNRT2.3 mediates low-affinity nitrate transport. 35S:LeNRT2.3 increased nitrate uptake in root and transport from root to shoot. More interestingly, 35S:LeNRT2.3 showed high biomass and fruit weight. Taken together, these results suggest that LeNRT2.3 plays a double role in nitrate uptake and long-distance transport in tomato.

  10. Effets du stress familial lié au diabète sur le contrôle glycémique chez les jeunes diabétiques de type 1

    PubMed Central

    Tsiouli, Elina; Alexopoulos, Evangelos C.; Stefanaki, Charikleia; Darviri, Christina; Chrousos, George P.

    2013-01-01

    Objectif Examiner la façon dont le stress familial influence le contrôle glycémique chez les patients diabétiques de moins de 18 ans. Sources des données Une recherche des études pertinentes publiées depuis 1990 a été réalisée dans PubMed et Scopus à l'aide des mots-clés suivants en anglais: diabetes type 1, glycemic control, family stress, family conflict et family function. Sélection des études La recension initiale a permis de cerner un total de 1 478 articles. La synthèse finale portrait sur 6 études de cohortes, 3 études transversales et 1 étude qualitative dans lesquelles le stress familial était évalué à l'aide d'instruments de mesure des conflits spécifiquement reliés au diabète et le contrôle glycémique était mesuré en fonction de l'hémoglobine glycosylée. Synthèse Dans la plupart des études, il existait une corrélation négative entre le stress familial et le contrôle glycémique des patients. Le bon fonctionnement familial était fortement relié à un bon contrôle glycémique des patients, tandis que les conflits familiaux étaient associés à un mauvais contrôle glycémique. Les familles dont la situation socioéconomique était défavorisée, celles ayant des adolescents atteints de diabète et les familles monoparentales étaient plus enclines à vivre un stress relié au diabète et étaient, par conséquent, plus susceptibles de connaître un moins bon contrôle glycémique. Conclusion Les interventions psychologiques thérapeutiques et les programmes éducatifs peuvent aider à atténuer le stress familial relié au diabète et amélioreront probablement le contrôle glycémique.

  11. Pertinence de l'implantation de la filiere granule de bois pour le Quebec

    NASA Astrophysics Data System (ADS)

    Tremblay, Stephan

    Les spécialistes avancent que le marché mondial de l'énergie en forte demande et en offre limitée nécessitera bientôt toutes les formes d'énergie disponibles. Le granulé de bois est une forme de bioénergie principalement utilisée pour le chauffage des bâtiments et pourrait être davantage considéré dans l'offre énergétique du Québec. Comme le Québec est un territoire où il fait froid et donc susceptible de pouvoir se tourner vers cette forme d'énergie, l'objectif de ce mémoire est d'en analyser les avantages. Pour ce faire, nous commencerons par démontrer la croissance des besoins énergétiques sur les plans national et international et dresser un portrait des différentes formes d'énergies consommées au Québec. Puisque la majorité des Québécois chauffent leurs bâtiments à l'hydroélectricité, nous analyserons à travers le plan d'approvisionnement d'Hydro-Québec le portrait de la production et de la consommation de cette forme d'énergie renouvelable. Cela nous permettra de constater le défi face à la gestion de surplus importants, sauf pendant la période hivernale, et ce faisant, l'obligation de la société d'État d'utiliser davantage ses centrales au gaz ou de se tourner vers l'importation de l'électricité. Dans la même lignée, un regard sera porté sur les perspectives d'utilisation de l'hydroélectricité sur les plans de la production d'aluminium, de l'exportation et de l'utilisation dans l'électrification des transports au Québec. Cette analyse se fera dans l'objectif de s'interroger sur la pertinence d'utiliser cette source d'énergie dans le chauffage plutôt que dans des secteurs plus créateurs de richesse. Nous poserons ensuite l'hypothèse que le granulé de bois pourrait être un bon substitut à une autre forme d'énergie utilisée dans le chauffage, soit le mazout. Avant de dresser un portrait de ce combustible fossile, nous ferons celui de la production et de la consommation de granulés sur les plans r

  12. Calibration of the LHCb calorimetric system

    NASA Astrophysics Data System (ADS)

    Pereima, D.

    2017-06-01

    The calorimeter system of LHCb provides information for the hardware Level-0 trigger for selection of events with high transverse energy electrons, hadrons and photons and also participates in offline particle identification and reconstruction. The main instruments and methods developed for monitoring and calibration of electromagnetic and hadron calorimeters are presented.

  13. The work of walking: a calorimetric study.

    PubMed

    Webb, P; Saris, W H; Schoffelen, P F; Van Ingen Schenau, G J; Ten Hoor, F

    1988-08-01

    Experiments were designed to test the traditional assumption that during level walking all of the energy from oxidation of fuel appears as heat and no work is done. Work is force expressed through distance, or energy transferred from a man to the environment, but not as heat. While wearing a suit calorimeter in a respiration chamber, five women and five men walked for 70 to 90 min on a level treadmill at 2.5, 4.6, and 6.7 km.h-1 and pedalled a cycle ergometer for 70 to 90 min against 53 and 92 W loads. They also walked with a weighted backpack and against a horizontal load. During cycling, energy from fuel matched heat loss plus the power measured by the ergometer. During walking, however, energy from fuel exceeded that which appeared as heat, meaning that work was done. The power increased with walking speed; values were 14, 29, and 63 W, which represented 11, 12, and 13% of the incremental cost of fuel above the resting level. Vertical and horizontal loads increased the fuel cost and heat loss of walking but did not alter the power output. This work energy did not re-appear as thermal energy during 18 h of recovery. The most likely explanation of the work done is in the inter-action between the foot and the ground, such as compressing the heel of the shoe and bending the sole. We conclude that work is done in level walking.

  14. A Calorimetric Investigation of Deuterated Palladium Electrodes

    DTIC Science & Technology

    1991-05-01

    Scientific Model 7709 heat- conduction calorimeter was used to measure the heat output from the cells. This calorimeter is based on the Seeback, or...The current was applied using an ECO battery cycler. The VTED and the temperature of the Al block (TAI°C) were monitored using the Hart Scientific Model ...1701 measuring system coupled with Keithley Model 197 Microvolt DVM. This data was recorded with an IBM compatible PC every 20 or 30 minutes

  15. A Calorimetric Investigation of Deuterated Palladium Electrodes

    DTIC Science & Technology

    1991-05-01

    LiOH in H20 (deionized and distilled) was prepared similarly. Calorimetry A commercially available Hart Scientific Model 7709 heat- conduction... Model 1701 measuring system coupled with Keithley Model ’q7 Microvolt DVM. This data was recorded with an IBM compatible PC every 20 or 30 minutes...deuterium. RESULTS AND DISCUSSION Electrolyses were started outside of the calorimeter and continued for two to twelve weeks. Occasionally, cells were

  16. Calorimetric measurement of energy of ultrasonic cleaners

    SciTech Connect

    Harding, W.B.

    1994-11-01

    The development of a calorimeter that measured the power within an ultrasonic cleaning tank is presented. The principle involved is explained. Several types of calorimeter that were tested are described. Measurement of the power in an ultrasonic cleaner permits: (1) comparing different ultrasonic cleaners; (2) monitoring the performance of a specific cleaner; (3) measuring the distribution of power in a cleaning tank, and (4) evaluating the effects of process variables on the power.

  17. Quatrième conférence consensuelle sur le diagnostic et le traitement de la démence

    PubMed Central

    Moore, Ainsley; Patterson, Christopher; Lee, Linda; Vedel, Isabelle; Bergman, Howard

    2014-01-01

    Résumé Objectif Revoir les stratégies diagnostiques de la maladie d’Alzheimer, actualiser les recommandations concernant le traitement des symptômes de démence et proposer une approche thérapeutique à la démence d’apparition précoce et d’évolution rapide. Composition du comité Des spécialistes et des délégués de diverses régions du Canada et représentant diverses disciplines pertinentes ont discuté et se sont mis d’accord sur les révisions à apporter aux lignes directrices de 2006. Méthodologie On a eu recours au système GRADE (grading of recommendations, assessment, development, and evaluation) pour évaluer le consensus concernant les recommandations, lequel était défini comme suit : lorsque 80 % ou plus des participants ont voté en faveur de la recommandation. La cote des données probantes est rapportée lorsque cela est possible. Rapport important pour les médecins de famille, malgré les progrès effectués dans les domaines des biomarqueurs liquidiens et de la neuro-imagerie, le diagnostic de démence au Canada demeure fondamentalement clinique. De nouveaux critères cliniques essentiels de diagnostic de la maladie d’Alzheimer en reconnaissent dorénavant les formes moins fréquentes et non amnestiques. La démence précoce, une affection rare, mais importante, devrait inciter les médecins à aiguiller les patients vers un spécialiste ayant accès à des conseillers en génétique. La démence d’évolution rapide, mal définie dans la littérature, faciliterait le dépistage de cette affection rare, mais importante. Les inhibiteurs de la cholinestérase sont maintenant indiqués pour le traitement d’affections autres que la maladie d’Alzheimer. Des lignes directrices concernant l’arrêt du traitement, lesquelles n’existaient pas auparavant, sont également apparues. De nouvelles données probantes sur le recours à la mémantine, aux antidépresseurs et à d’autres agents psychotropes dans le traitement de la

  18. Modelisation frequentielle de la permittivite du beton pour le controle non destructif par georadar

    NASA Astrophysics Data System (ADS)

    Bourdi, Taoufik

    Le georadar (Ground Penetrating Radar (GPR)) constitue une technique de controle non destructif (CND) interessante pour la mesure des epaisseurs des dalles de beton et la caracterisation des fractures, en raison de ses caracteristiques de resolution et de profondeur de penetration. Les equipements georadar sont de plus en plus faciles a utiliser et les logiciels d'interpretation sont en train de devenir plus aisement accessibles. Cependant, il est ressorti dans plusieurs conferences et ateliers sur l'application du georadar en genie civil qu'il fallait poursuivre les recherches, en particulier sur la modelisation et les techniques de mesure des proprietes electriques du beton. En obtenant de meilleures informations sur les proprietes electriques du beton aux frequences du georadar, l'instrumentation et les techniques d'interpretation pourraient etre perfectionnees plus efficacement. Le modele de Jonscher est un modele qui a montre son efficacite dans le domaine geophysique. Pour la premiere fois, son utilisation dans le domaine genie civil est presentee. Dans un premier temps, nous avons valide l'application du modele de Jonscher pour la caracterisation de la permittivite dielectrique du beton. Les resultats ont montre clairement que ce modele est capable de reproduire fidelement la variation de la permittivite de differents types de beton sur la bande de frequence georadar (100 MHz-2 GHz). Dans un deuxieme temps, nous avons montre l'interet du modele de Jonscher en le comparant a d'autres modeles (Debye et Debye-etendu) deja utilises dans le domaine genie civil. Nous avons montre aussi comment le modele de Jonscher peut presenter une aide a la prediction de l'efficacite de blindage et a l'interpretation des ondes de la technique GPR. Il a ete determine que le modele de Jonscher permet de donner une bonne presentation de la variation de la permittivite du beton dans la gamme de frequence georadar consideree. De plus, cette modelisation est valable pour differents

  19. The Le Fort III osteotomy: to distract or not to distract?

    PubMed

    Fearon, J A

    2001-04-15

    Treatment of the craniofacial dysostoses (e.g., Crouzon, Apert, Pfeiffer, Saethre-Chotzen syndromes) is critically dependent on the successful advancement of the midface with a Le Fort III procedure. The purpose of this retrospective clinical outcome study was to evaluate a new technique for distracting the Le Fort III procedure and to compare its results in growing children with those of the standard Le Fort III osteotomy. The records of 22 children were reviewed; 10 patients (mean age, 6.5 years) underwent a standard Le Fort III procedure, and 12 patients (mean age, 7.5 years) underwent a Le Fort III distraction procedure. The distraction group included two separate techniques, bilateral buried distraction (n = 2) and halo distraction (n = 10). Preoperative and 2- to 3-month postoperative cephalograms were analyzed. The average horizontal advancement achieved in the standard Le Fort III group was 6 mm, compared with 19 mm of advancement in the distraction group (p Le Fort III group. However, in the distraction group two patients experienced normalization of sleep studies postoperatively as measured by respiratory disturbance index, and two patients underwent successful decannulation of tracheotomies. For aesthetic reasons, halo distraction was preferred over bilateral buried distraction. With halo distraction the vector of traction is focused in the facial midline, which helps to reposition the concave midface and to provide a more convex facial profile. In growing children, the ideal vector for distraction is determined by the malar position and not by dental occlusion. The amount of overcorrection can be calculated from tables of normal anthropologic data. On this preliminary review, it was concluded that the use of

  20. Le modele de Hubbard bidimensionnel a faible couplage: Thermodynamique et phenomenes critiques

    NASA Astrophysics Data System (ADS)

    Roy, Sebastien

    Une etude systematique du modele de Hubbard en deux dimensions a faible couplage a l'aide de la theorie Auto-Coherente a Deux Particules (ACDP) dans le diagramme temperature-dopage-interaction-sauts permet de mettre en evidence l'influence des fluctuations magnetiques sur les proprietes thermodynamiques du systeme electronique sur reseau. Le regime classique renormalise a temperature finie pres du dopage nul est marque par la grandeur de la longueur de correlation de spin comparee a la longueur thermique de de Broglie et est caracterisee par un accroissement drastique de la longueur de correlation de spin. Cette croissance exponentielle a dopage nul marque la presence d'un pic de chaleur specifique en fonction de la temperature a basse temperature. Une temperature de crossover est alors associee a la temperature a laquelle la longueur de correlation de spin est egale a la longueur thermique de de Broglie. C'est a cette temperature caracteristique, ou est observee l'ouverture du pseudogap dans le poids spectral, que se situe le maximum du pic de chaleur specifique. La presence de ce pic a des consequences sur l'evolution du potentiel chimique avec le dopage lorsque l'uniformite thermodynamique est respectee. Les contraintes imposees par les lois de la thermodynamique font en sorte que l'evolution du potentiel chimique avec le dopage est non triviale. On demontre entre autres que le potentiel chimique est proportionnel a la double occupation qui est reliee au moment local. Par ailleurs, une derivation de la fonction de mise a l'echelle de la susceptibilite de spin a frequence nulle au voisinage d'un point critique marque sans equivoque la presence d'un point critique quantique en dopage pour une valeur donnee de l'interaction. Ce point critique, associe a une transition de phase magnetique en fonction du dopage a temperature nulle, induit un comportement non trivial sur les proprietes physiques du systeme a temperature finie. L'approche quantitative ACDP permet de

  1. Amphibians and Reptiles of the state of Nuevo León, Mexico.

    PubMed

    Lemos-Espinal, Julio A; Smith, Geoffrey R; Cruz, Alexander

    2016-01-01

    We compiled a check list of the herpetofauna of Nuevo León. We documented 132 species (23 amphibians, 109 reptiles), representing 30 families (11 amphibians, 19 reptiles) and 73 genera (17 amphibians, 56 reptiles). Only two species are endemic to Nuevo León. Nuevo León contains a relatively high richness of lizards in the genus Sceloporus. Overlap in the herpetofauna of Nuevo León and states it borders is fairly extensive. Of 130 native species, 102 are considered species of Least Concern in the IUCN red list, four are listed as Vulnerable, five are listed as Near Threatened, and four are listed as Endangered. According to SEMARNAT, 78 species are not of conservation concern, 25 are subject to Special Protection, 27 are Threatened, and none are listed as in Danger of Extinction. Given current threats to the herpetofauna, additional efforts to understand the ecology and status of populations in Nuevo León are needed.

  2. [Nicolás León, pioneer figure in the history of medicine].

    PubMed

    Rodríguez, Martha Eugenia

    2003-01-01

    To study Nicolás León (1859-1929) as historian of medicine, field in which he left 48 publications, out of a total of approximately 525. Most of the information analyzed is supported by primary sources, written by León himself. Nicolás León contributed mainly to present a general outlook of the history of medicine in Mexico, obstetrics being the field which he most thoroughly investigated, from Prehispanic period up to León's own times. The fact that he faced problems in order to obtain information, made him not only write, but also compile scattered data and uncommon or peculiar works. Nicolás León can be considered as one of the pioneers in the history of medicine, field which he enthusiastically encouraged, first from the city where he was born in the State of Michoacán, and later on, in Mexico City. In fact, we may assure that he was much more important as a historian of medicine than as a physician.

  3. Vaccinia virus p37 interacts with host proteins associated with LE-derived transport vesicle biogenesis.

    PubMed

    Chen, Yali; Honeychurch, Kady M; Yang, Guang; Byrd, Chelsea M; Harver, Chris; Hruby, Dennis E; Jordan, Robert

    2009-04-28

    Proteins associated with the late endosome (LE) appear to play a central role in the envelopment of a number of taxonomically diverse viruses. How viral proteins interact with LE-associated proteins to facilitate envelopment is not well understood. LE-derived transport vesicles form through the interaction of Rab9 GTPase with cargo proteins, and TIP47, a Rab9-specific effector protein. Vaccinia virus (VV) induces a wrapping complex derived from intracellular host membranes to envelope intracellular mature virus particles producing egress-competent forms of virus. We show that VV p37 protein associates with TIP47-, Rab9-, and CI-MPR-containing membranes. Mutation of a di-aromatic motif in p37 blocks association with TIP47 and inhibits plaque formation. ST-246, a specific inhibitor of p37 function, inhibits these interactions and also blocks wrapped virus particle formation. Vaccinia virus expressing p37 variants with reduced ST-246 susceptibility associates with Rab9 and co-localizes with CI-MPR in the presence and absence of compound. These results suggest that p37 localizes to the LE and interacts with proteins associated with LE-derived transport vesicle biogenesis to facilitate assembly of extracellular forms of virus.

  4. Vaccinia virus p37 interacts with host proteins associated with LE-derived transport vesicle biogenesis

    PubMed Central

    Chen, Yali; Honeychurch, Kady M; Yang, Guang; Byrd, Chelsea M; Harver, Chris; Hruby, Dennis E; Jordan, Robert

    2009-01-01

    Background Proteins associated with the late endosome (LE) appear to play a central role in the envelopment of a number of taxonomically diverse viruses. How viral proteins interact with LE-associated proteins to facilitate envelopment is not well understood. LE-derived transport vesicles form through the interaction of Rab9 GTPase with cargo proteins, and TIP47, a Rab9-specific effector protein. Vaccinia virus (VV) induces a wrapping complex derived from intracellular host membranes to envelope intracellular mature virus particles producing egress-competent forms of virus. Results We show that VV p37 protein associates with TIP47-, Rab9-, and CI-MPR-containing membranes. Mutation of a di-aromatic motif in p37 blocks association with TIP47 and inhibits plaque formation. ST-246, a specific inhibitor of p37 function, inhibits these interactions and also blocks wrapped virus particle formation. Vaccinia virus expressing p37 variants with reduced ST-246 susceptibility associates with Rab9 and co-localizes with CI-MPR in the presence and absence of compound. Conclusion These results suggest that p37 localizes to the LE and interacts with proteins associated with LE-derived transport vesicle biogenesis to facilitate assembly of extracellular forms of virus. PMID:19400954

  5. A learned artisan debates the system of the world: Le Clerc versus Mallemant de Messange.

    PubMed

    Rabinovitch, Oded

    2017-10-11

    Sébastien Le Clerc (1637-1714) was the most renowned engraver of Louis XIV's France. For the history of scientific publishing, however, Le Clerc represents a telling paradox. Even though he followed a traditional route based on classic artisanal training, he also published extensively on scientific topics such as cosmology and mathematics. While contemporary scholarship usually stresses the importance of artisanal writing as a direct expression of artisanal experience and know-how, Le Clerc's publications, and specifically the work on cosmology in his Système du monde (1706-1708), go far beyond this. By reconstructing the debate between Le Clerc and the professor Mallemant de Messange on the authorship of this 'system of the world', this article argues that Le Clerc's involvement in publishing ventures shaped his identity both as an artisan and as a scientific author. Whereas the Scientific Revolution supposedly heralded a change from the world of 'more or less' to the 'world of precision', this article shows how an artisan could be more 'precise' than the learned scholar whose claims he disputed, and points to the importance of the literary field as a useful lens for observing the careers of early modern scientific practitioners.

  6. Diffusion des macromolécules de dextrane dans le gel Séphadex G-200

    NASA Astrophysics Data System (ADS)

    Moussaoui, M.; Hamieh, T.; Toufaily, J.; Naoufal, D.

    2005-05-01

    Dans cet article nous avons étudié la diffusion des macromolécules de dextrane marquées à l'isothiocyanate de fluorescéine (FITC), dans les perles de l'ultrogel AcA34, par la méthode du retour de la fluorescence après photoblanchiment (FRAP). Le coefficient de partage chromatographique (Kc), a été déterminé par chromatographie sur une colonne de l'ultrogel AcA34. Le coefficient de partage microfluorimétrique (Kf) a été déterminé par la technique de (FRAP), en mesurant à la fois, la fluorescence dans la perle et dans le solvant. La relation entre le coefficient de partage chromatographique et le rayon de Stokes (Rs) des macromolécules a été étudiée en appliquant la relation de Laurent et Killender, alors que la variation du coefficient de diffusion relatif D/D0, a été étudiée en fonction de Kc en appliquant la théorie d'Ogston et al.

  7. Hypertension during chronic exposure to cold: Comparison between Sprague Dawley (SD) and Long Evans (LE) strains

    SciTech Connect

    Riesselmann, A.; Baron, A.; Fregly, M.J. )

    1991-03-11

    Hypertension accompanies chronic exposure of SD rats to cold (5-6C), including elevation of systolic, diastolic, and mean blood pressures and cardiac hypertrophy. The renin-angiotensin system may play an important role. Earlier studies suggested that the LE strain may have a decrease in angiotensin I converting enzyme (ACE) activity. Measurement of ACE activity in plasmas of SE and LE strains revealed that basal activity of ACE in the plasma of the LE strain was significantly less than that of the SD strain. A second study was carried out in which both strains were exposed to cold for 7 weeks. There were clear differences between strains. Rats of the SD strain had a significant elevation in their blood pressure; a significantly increased urinary output of norepinephrine (NE) and epinephrine (E); and significant increases in weights of heart, kidneys, adrenals, and brown adipose tissue (IBAT) compared to their controls maintained at 26C. In contrast, rats of the LE strain were less responsive to cold in that blood pressure failed to rise as sharply and to attain as high a level; NE and E outputs, as well as weights of heart and IBAT were significantly less than those of rats of the cold-treated SD strain. Thus, the lower ACE activity in plasma of LE strain, as well as a reduced secretion of catecholamines, may protect these rats against the rise of blood pressure characteristically observed when rats of the SD strain are exposed to cold.

  8. Helen Primrose LeVesconte: occupational therapy clinician, educator, and maker of history.

    PubMed

    Friedland, Judith; Rais, Hadassah

    2005-06-01

    The Canadian history of our profession is not well known and our identity is thought to suffer as a result. Helen Primrose LeVesconte (7896-1982) is one pioneer in our development whose story has not been told. Our purpose is to explore LeVesconte's life and work in order to expand knowledge of our roots and thereby strengthen our identity. Using interpretive biography methods we draw on LeVesconte's own writings, articles written about her, and archival documents to describe turning point moments in her life and to display meaningful patterns in her work. LeVesconte's work as a clinician and her role and reputation as an educator, show her to have been a strong and visionary leader. Her views on the client's role, the importance of the therapist-client relationship, prevention, community-based programs, and vocational rehabilitation are of particular interest. Because LeVesconte educated over 1,850 students while director of the occupational therapy program at the University of Toronto, her influence has been felt throughout the country. Her perspective is compared to current practice; and questions are raised as to aspects of her legacy and philosophy that might now be reconsidered.

  9. Leishmaniose viscerale et leucemie aigüe lymphoblastique B: quel est le rapport?

    PubMed Central

    El Youssi, Hind; Touaoussa, Aziz; Bergui, Imane; Bougrine, Nawal; Amrani, Moncef Hassani

    2015-01-01

    L'association leishmaniose viscérale et leucémie aigue a été rarement rapportée dans la littérature, cependant le diagnostic concomitant de ces deux entités n'a jamais été rapporté au Maroc. Le lien entre ces deux pathologies n'a pas encore été établi et le traitement n'a pas encore été codifié. Nous rapportons le cas d'un garçon de 12 ans chez qui une leishmaniose viscérale et une leucémie aigue lymphoblastique type B ont été diagnostiquées simultanément. Malgré l'administration d'un traitement antiparasitaire associé à une chimiothérapie l’évolution était marquée par le décès du patient. PMID:26090011

  10. LeCDJ1, a chloroplast DnaJ protein, facilitates heat tolerance in transgenic tomatoes.

    PubMed

    Kong, Fanying; Deng, Yongsheng; Wang, Guodong; Wang, Jieru; Liang, Xiaoqing; Meng, Qingwei

    2014-01-01

    The roles of a tomato (Lycopersicon esculentum) chloroplast-targeted DnaJ protein (LeCDJ1) were investigated using wild-type (WT) and sense transgenic tomatoes. The LeCDJ1 expression was upregulated by 38 °C, 42 °C, 45 °C, NaCl, PEG, methyl viologen (MV) and hydrogen peroxide (H2O2), but not by 30 °C and 35 °C. Meanwhile, LeCDJ1 was involved in the response of plants to abscisic acid (ABA). Under heat stress, the sense plants showed better growth, higher chlorophyll content, lower malondialdehyde (MDA) accumulation and relative electrical conductivity (REC), and also less PSII photoinhibition than WT. Interestingly, the sense plants treated with streptomycin (SM), an inhibitor of organellar translation, still showed higher maximum photochemistry efficiency of PSII (Fv/Fm) and D1 protein levels than the SM-untreated WT, suggesting that the protective effect of LeCDJ1 on PSII was, at least partially, independent of D1 protein synthesis. Furthermore, the relatively lower superoxide radical (O2(•-)) and H2O2 levels in the sense plants were considered to be due to the higher ascorbate peroxidase (APX) and superoxide dismutase (SOD) activity, which seemed unlikely dependent on their transcription level. These results indicated that LeCDJ1 overexpression facilitated heat tolerance in transgenic tomatoes. © 2013 Institute of Botany, Chinese Academy of Sciences.

  11. Amphibians and Reptiles of the state of Nuevo León, Mexico

    PubMed Central

    Lemos-Espinal, Julio A.; Smith, Geoffrey R.; Cruz, Alexander

    2016-01-01

    Abstract We compiled a check list of the herpetofauna of Nuevo León. We documented 132 species (23 amphibians, 109 reptiles), representing 30 families (11 amphibians, 19 reptiles) and 73 genera (17 amphibians, 56 reptiles). Only two species are endemic to Nuevo León. Nuevo León contains a relatively high richness of lizards in the genus Sceloporus. Overlap in the herpetofauna of Nuevo León and states it borders is fairly extensive. Of 130 native species, 102 are considered species of Least Concern in the IUCN red list, four are listed as Vulnerable, five are listed as Near Threatened, and four are listed as Endangered. According to SEMARNAT, 78 species are not of conservation concern, 25 are subject to Special Protection, 27 are Threatened, and none are listed as in Danger of Extinction. Given current threats to the herpetofauna, additional efforts to understand the ecology and status of populations in Nuevo León are needed. PMID:27408562

  12. Le naevus bleu cellulaire atypique du poignet: à propos d'un cas et revue de la literature

    PubMed Central

    Boussakri, Hassan; Roux, Jean Luc; Durand, Luc; Elibrahimi, Abdelhalim; Elmrini, Abdelmajid

    2014-01-01

    Le naevus bleu cellulaire atypique est une entité pathologique rare et sa localisation au niveau du poignet est exceptionnelle. Il est Considéré comme une Variante à des caractéristiques intermédiaires entre le naevus bleu cellulaire typique et le naevus bleu malin, dont l’évolution est incertaine. Le but de notre travail est d'attirer l'attention sur cette variété lésionnelle rare et de discuter les diagnostiques différentiels, ainsi que décrire les aspects histologique et les options thérapeutiques possibles. PMID:25426206

  13. "Panic": the impact of Le Bon's crowd psychology on U.S. military thought.

    PubMed

    Bendersky, Joseph W

    2007-01-01

    The controversial crowd psychology of Gustave Le Bon has been both praised as an incisive contribution to social theory and also condemned as a doctrine of irrationality and mass manipulation associated with fascism. New archival documentation now demonstrates that Le Bon exercised significant influence on U.S. military thinking and practice through World War II. Army writings and officer training on morale, leadership, and battlefield psychology rested substantially on his theory of crowds, particularly regarding races and panic. Le Bon's racial psychology took on additional importance when the African-American 92 nd Infantry Division panicked during combat in Italy. This new evidence offers an excellent case study of the direct and enduring impact of a peculiar type of social psychology on the institutional culture of the army from the classrooms at the Army War College to the battlefield itself. (c) 2007 Wiley Periodicals, Inc.

  14. à quoi doit servir le patrimoine astronomique français?

    NASA Astrophysics Data System (ADS)

    Caplan, J.; Vila, B.

    2012-12-01

    Les deux auteurs, l'un astronome l'autre botaniste (et chargé de mission patrimoine de l'université d'Aix-Marseille), présentent quelques idées sur la gestion des collections historiques d'astronomie, dans un contexte universitaire. Nous mettons en avant la spécificité de ces collections par rapport à celles des musées traditionnels et leur importance pour l'histoire des sciences notamment. Nous rappelons également la nécessité de suivre la déontologie muséale soutenue par l'association Universeum, réseau européen pour le patrimoine universitaire. Enfin nous rappelons lele essentiel que jouent les réserves et la nécessité de travailler en collaboration.

  15. Quand le bloc axillaire reste la seule alternative chez un enfant de 5 ans

    PubMed Central

    Nakhli, Mohamed Said; Béjaoui, Nawel; Naija, Walid; Mhamdi, Salah; Said, Rachid

    2015-01-01

    Le bloc axillaire par neurostimulation chez l'enfant n'est pas une technique habituelle, surtout avec le développement des techniques d'anesthésie locorégionale échoguidées. Cependant elle peut être une alternative intéressante si l'anesthésie générale est a risque voir même contre indiquée. Nous rapportons le cas d'un bloc axillaire anesthésique chez un enfant de 5 ans porteur d'un kyste hydatique du poumon et une hépatite A sévère proposé pour une fixation de fracture du condyle externe de l'humérus. PMID:26405472

  16. Developmental History of Liquid Oxygen Turbopumps for the LE-7 Engine

    NASA Astrophysics Data System (ADS)

    Kamijo, Kenjiro; Yamada, Hitoshi; Sakazume, Norio; Warashina, Shogo

    The first stage of the H-2 rocket used a 110-ton thrust liquid oxygen, liquid hydrogen, pump-fed engine, the LE-7. This engine required high-pressure and high-power liquid oxygen and liquid hydrogen turbopumps to achieve the two-stage combustion cycle in which the combustion pressure is around 13 MPa. Furthermore, it was very important to operate both turbopumps at higher rotational speeds to obtain a smaller, lighter-weight engine because the LE-7 had not low-speed, low-pressure pumps ahead of both the main pumps. The present paper shows the design, test results, and modifications that had been performed until a flight-type liquid oxygen turbopump for the LE-7 engine was completed. The liquid oxygen turbopump had been developed by the use of three models, that is, research, prototype, and flight models.

  17. Le syndrome d'Othello: un cas observé à Ouagadougou

    PubMed Central

    Kaboré, Bawindsongré Jean; Napon, Christian

    2013-01-01

    Les auteurs rapportent le premier cas de délire de jalousie encore décrit sous l'acronyme de syndrome d'Othello, à Ouagadougou. Il s'est agit d'un patient qui au décours d'un accident vasculaire cérébral ischémique constitué, a développé un délire de jalousie. Une revue de la littérature permet de comprendre que l'affection, rarement rapportée est de plus en plus décrite au décours de maladies neurologiques aigues ou chroniques, et que le lobe frontal joue vraisemblablement un rôle majeur. PMID:24570777

  18. A CYTOCHEMICAL STUDY OF THE L.E. BODIES OF SYSTEMIC LUPUS ERYTHEMATOSUS

    PubMed Central

    Godman, Gabriel C.; Deitch, Arline D.

    1957-01-01

    Microspectrophotometric comparison of lymphocyte nuclei and free L.E. bodies which are derived from them show a more than twofold average increase in the latter of protein basic groups revealed by naphthol yellow S binding, and tyrosine residues demonstrated by the Millon reaction. The alkaline fast green method for histones and the Sakaguchi reaction for arginine residues suggest that there is a marked loss and ultimate disappearance of histones in the course of formation of the L.E. body from a nucleus. It is postulated that the L.E. transformation entails influx of protein normally foreign to the nucleus, displacement of histone from combination of DNA, and association of the DNA with the new protein which is then responsible for masking the anionic groups of DNA. PMID:13475616

  19. Le Fort I Osteotomy with Bone Grafts in Preprosthetic Surgery: Technical Note

    PubMed Central

    Pingarron-Martin, Lorena; Arias-Gallo, Javier; Ong, Hui Shan; Pons, Manuel Chamorro

    2013-01-01

    Background Being edentulous causes progressive bony resorption in maxillae, which can lead to altered maxillomandibular relationships. Discussion should consider Le Fort I osteotomy with inlay grafts for a better success rate. Thus, this article introduces a technical note in improving the success rate. Case Report The presented technical note permits transformation of the surgery in a conventional Le Fort I with a simple fixation not only of the grafts but also of the osteotomy. The surgical steps are explained as well as the follow-up results. Discussion Adding additional wire anchorage around bone grafts greatly improved our success rate and reduced our operative time. Bone grafting concurrently with Le Fort I osteotomy immediately improved the facial skeletal profile. Several in vitro studies have shown that galvanic corrosion does not play a significant role when combining stainless steel and titanium. Our novel technique is relatively simple and can be easily picked up by young surgeons. PMID:24436751

  20. Le conflit fémoro-acétabulaire et la coxarthrose

    PubMed Central

    Zhang, Charlie; Li, Linda; Forster, Bruce B.; Kopec, Jacek A.; Ratzlaff, Charles; Halai, Lalji; Cibere, Jolanda; Esdaile, John M.

    2015-01-01

    Objectif Expliquer la présentation clinique, les observations à l’examen physique, les critères diagnostiques et les options de prise en charge du conflit fémoroacétabulaire (CFA). Sources des données Une recherche documentaire a été effectuée dans PubMed pour trouver des articles pertinents sur la pathogenèse, le diagnostic, le traitement et le pronostic du CFA. Message principal Depuis les dernières années, on reconnaît de plus en plus que le CFA est un précurseur potentiel et une étiologie importante des douleurs à la hanche dans la population adulte et de la coxarthrose idiopathique plus tard dans la vie. Le conflit fémoro-acétabulaire désigne un ensemble d’anomalies morphologiques osseuses de l’articulation de la hanche qui se traduit par un contact anormal durant le mouvement. Le CFA par effet came concerne une proéminence osseuse non sphérique du col fémoral proximal ou de la jonction tête-col. Le CFM par effet tenaille désigne une couverture acétabulaire excessive par-dessus la tête du fémur, qui peut se produire en raison de diverses variantes morphologiques. Les patients qui ont un CFA présentent une douleur inguinale antérieure chronique, profonde ou lancinante, le plus souvent en position assise, durant ou après une activité. Les patients peuvent aussi ressentir des douleurs occasionnelles aiguës durant l’activité. Il faut procéder à une anamnèse approfondie portant notamment sur l’incidence de traumatismes ou la fréquence de l’exercice. Il faut aussi faire un examen physique complet des hanches, de la région lombaire et de l’abdomen pour évaluer d’autres causes de douleurs inguinales antérieures. Le diagnostic de CFA est confirmé par radiographie. Le conflit fémoro-acétabulaire peut être pris en charge selon une approche conservatrice comportant du repos, la modification des activités, des médicaments et de la physiothérapie ou encore être traité par intervention chirurgicale. Conclusion

  1. Progress on the Development of Two-Dimension Eulerian-Lagrangian Code LeFIX

    SciTech Connect

    Sunchai, Nilsuwankosit; IkKyu, Park; JinHo, Song

    2006-07-01

    In order to improve on the analysis and the simulation of the process of fuel-coolant interaction, a code capable of simulating the motions of the fuel particles and two phases of the fluid is considered. Based on the old two-fluid code called K-FIX and LeSiM, the newly developed set of subroutines to simulate the motion and the interaction of the Lagrangian particles, the new two-dimension two-fluid thermal hydraulic code called LeFIX is being developed. For solving the conservation equations, the algorithm employed by LeFIX was modified from that used in K-FIX. However, since the correlations for liquid-vapor heat transfer coefficients in droplet and bubbly flows together with the drag coefficient between two phases of the fluid in the same flow scheme had not been modeled in KFIX, they were specifically implemented. In addition, the simplified functions specifying the properties of the liquid water and the steam were also introduced. Currently, LeFIX was verified to give the results identical to that of K-FIX when they were run under the condition where each phase of the fluid were incompressible, with constant but very high heat and momentum transfer rates. In this specific work, LeFIX was tested for the condition in which the steam bubbles gradually rose in the cylindrical volume filled with the subcooled liquid water. The obtained results showed that LeFIX could reasonably well simulate the motion by each phase of the fluid and also their interactions. With the models for the fluid being completed, testing the interaction of the two-phase fluid with the Lagrangian particles is to be the next stage of the development. (authors)

  2. Hemoglobin Le Lamentin in the province of Albacete, Spain: Discovery of 32 cases.

    PubMed

    Martínez-López, Rosalina; Ropero, Paloma; Ballesteros Gallar, Cristina; Romero Román, Carlos; de la Fuente-Gonzalo, Félix; M Nieto, Jorge; Navarro Casado, Laura; González, Fernando A

    2017-03-01

    Hemoglobin Le Lamentin (α20(B1)His→Gln) is a ubiquitous variant that has been previously described in a small number of isolated patients. We report the incidental observation of Hb Le Lamentin in a large population from the province of Albacete, in southeastern Spain. Our study investigates possible reasons for the elevated number of carriers of this variant and its implications for the management of diabetes in our region. The subjects are 32 diabetic patients whose hemoglobin displayed an unusual peak while they were being tested for glycated hemoglobin at the laboratory of the University General Hospital of Albacete over a 3-year period. Measurements were made by high performance liquid chromatography using a Variant™ II Turbo Kit-2.0, and subsequently the samples of the 32 patients with anomalous peaks were sent to the Hospital Clínico San Carlos (Madrid, Spain) for molecular characterization of any Hb variants. Molecular studies revealed 31 out of 32 patients heterozygous for Le Lamentin, and in one of them, Hb City of Hope was associated with Hb Le Lamentin. The remaining patient was homozygous for the Le Lamentin mutation. Additionally, most patients were native to the northeastern half of the province of Albacete and were unrelated. Our study describes the largest finding to date of hemoglobin Le Lamentin in a sample of patients. The fact that our region has been perpetually depopulated, with a population that has remained stable in small localities over the centuries, may have favored the survival of the mutation. Since the presence of this variant underestimates the true value of glycated hemoglobin measured by HPLC, it is necessary to systematically review chromatograms. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  3. Infection par le virus de l’hépatite E durant la grossesse

    PubMed Central

    Chaudhry, Shahnaz A.; Verma, Natasha; Koren, Gideon

    2015-01-01

    Résumé Question Plusieurs de mes patientes sont originaires de l’Asie du Sud-Est où le virus de l’hépatite E est assez commun. Quelles précautions puis-je leur suggérer de prendre avant de voyager dans cette région et quels sont les risques d’une infection par le VHE durant la grossesse? Réponse L’hépatite E est un pathogène présent dans l’eau qui se transmet par voie oro-fécale. Afin de réduire le risque de contracter le VHE lors de voyages dans des régions endémiques, il est important de maintenir des pratiques d’hygiène telles que se laver les mains avec de l’eau potable, particulièrement avant de manipuler de la nourriture, éviter de boire de l’eau ou d’utiliser des glaçons de pureté inconnue et ne pas manger de fruits ou de légumes non pelés. Actuellement, il n’existe aucun vaccin disponible au Canada pour le VHE. Une infection à l’hépatite E durant la grossesse, surtout durant le troisième trimestre, se caractérise par une infection plus sévère qui se transforme parfois en hépatite fulminante, augmentant ainsi les risques de mortalité et de morbidité maternelles et fœtales.

  4. Oncoplastie avec conservation mammaire dans le traitement du cancer du sein: à propos de 16 cas

    PubMed Central

    Bouzoubaa, Wail; Laadioui, Meryam; Jayi, Sofia; Alaoui, Fatime Zahra Fdili; Bouguern, Hakima; Chaara, Hikmat; Melhouf, Moulay Abdelilah

    2015-01-01

    Le cancer du sein est actuellement le cancer le plus fréquent chez la femme, et pose un véritable problème diagnostique et thérapeutique. Le dépistage des lésions à un stade de plus en plus précoce, a permis une extension des indications du traitement conservateur radiochirurgical, qui était initialement limitées aux tumeurs de moins de 3 cm, unifocales, non inflammatoires. Par ailleurs, l'utilisation de traitements préopératoires permet d’étendre les indications du traitement conservateur à des tumeurs plus volumineuses. Parallèlement à cette extension des indications de conservation mammaire, on a observé le développement de nouvelles approches thérapeutiques notamment la chirurgie oncoplastique, technique du ganglion sentinelle et chirurgie stéréotaxique, dont les résultats initiaux sont très encouragent. A travers cette étude réalisée dans le service de gynécologie et obstétrique II du CHU HASSAN II de FES au MAROC, après l'analyse rétrospective de 16 patientes traitées par traitement conservateur et oncoplastie, nous avons voulus montrer notre aptitude a réalisé ses techniques chirurgicales et a bien prendre en charge ces patientes, mais aussi évaluer ces techniques en termes de résultat carcinologique et de résultat esthétique, aussi en terme de survie globale, survie sans métastase et en termes de récidive locale entre les plasties mammaires et les traitements usuels: mastectomie et traitement conservateur classique. PMID:26430477

  5. Causes de décès des patients infectés par le VIH dans le Centre tunisien

    PubMed Central

    Chelli, Jihène; Bellazreg, Foued; Aouem, Abir; Hattab, Zouhour; Mesmia, Hèla; Lasfar, Nadia Ben; Hachfi, Wissem; Masmoudi, Tasnim; Chakroun, Mohamed; Letaief, Amel

    2016-01-01

    La trithérapie antirétrovirale a contribué à une baisse considérable de la mortalité liée au VIH. Les causes de décès sont dominées par les infections opportunistes dans les pays en voie de développement et par les maladies cardiovasculaires et les cancers dans les pays développés. L’objectif était de déterminer les causes et les facteurs de risque de décès des patients infectés par le VIH dans le Centre Tunisien. Une étude transversale auprès des patients infectés par le VIH âgés de plus de 15 ans suivis à Sousse et à Monastir entre 2000 et 2014. Le décès était considéré lié au VIH si la cause était un évènement classant SIDA ou s’il était la conséquence d’une infection opportuniste d’étiologie indéterminée avec des CD4 < 50/mm3, non lié au VIH si la cause n’était pas un évènement classant SIDA, et de cause inconnue si aucune information n’était disponible. Deux cents treize patients, 130 hommes (61%) et 83 femmes (39%), d’âge moyen 40±11 ans ont été inclus. Cinquante quatre patients sont décédés, avec une mortalité de 5,4/100 patients-années. La mortalité annuelle a baissé de 5,8% en 2000-2003 à 2,3% en 2012-2014. La survie était de 72% à 5 ans et de 67% à 10 ans. Les décès étaient liés au VIH dans 70,4% des cas. Les causes de décès les plus fréquentes étaient la pneumocystose pulmonaire et la cryptococcose neuroméningée dans 6 cas (11%) chacune. Les facteurs de risque de décès étaient les antécédents d’infections opportunistes, la durée de la trithérapie antirétrovirale < 12 mois et le tabagisme. Le renforcement du dépistage, l’initiation précoce de la trithérapie antirétrovirale, et la lutte contre le tabagisme sont nécessaires afin de réduire la mortalité chez les patients infectés par le VIH en Tunisie. PMID:28292068

  6. le de la radiothérapie dans le traitement de l'améloblastome: à propos de deux cas

    PubMed Central

    El Mazghi, Abderrahman; Bouhafa, Touria; El Kacemi, Hanan; Loukili, Kaoutar; Chbani, Laila; Kebdani, Taieb; Hassouni, Khalid

    2014-01-01

    L'améloblastome est une tumeur odontogène bénigne mais à pouvoir agressif et invasif local important. C'est une tumeur rare, elle représente 1% des tumeurs des maxillaires. Lele de la radiothérapie dans son traitement est actuellement démontré pour les tumeurs inopérables. Nous rapportons 2 cas d'améloblastomes mandibulaires chez deux patients qui ont bénéficié d'une radiothérapie externe à la dose de 60 Gy. L’évolution a été marquée par une rémission complète de la maladie dans les deux cas avec un recul de 2 et 5 ans. PMID:25722762

  7. Technology for Evolutionary Software Development (Technologies pour le developpement de logiciels evolutifs)

    DTIC Science & Technology

    2003-06-01

    performs its mission with the support of an extensive network of national experts. It also ensures effective coordination with other NATO bodies involved in...intégré unique pour le matériel, le logiciel et la logistique . La session sur les stratégies et les approches, qui était axée sur un système...development process.3 • Requirements Engineering – Quality, Performance and Cost requirements quantified. Evolutionary development can be viewed as a

  8. Le glaucome congénitale et la neurofibromatose type 1

    PubMed Central

    Tzili, Nazih; El Orch, Hamza; Bencherifa, Fatiha; Chefchaouni, Mohammed Charif; Abdallah, El Hassan; Berraho, Amina

    2015-01-01

    Le glaucome congénital constitue une complication ophtalmologique dans la neurofibromatose type 1 ou maladie de von Recklinghausen. Nous rapportons un cas de glaucome congénitale dans le cadre d'une neurofibromatose de type 1, à travers lequel on va discuter les mécanismes étiopathogénique, les difficultés thérapeutiques et les facteurs pronostiques du glaucome congénital au cours la maladie de von Recklinghausen avec revue de la littérature. PMID:26405492

  9. Conductivite dans le modele de Hubbard bi-dimensionnel a faible couplage

    NASA Astrophysics Data System (ADS)

    Bergeron, Dominic

    Le modele de Hubbard bi-dimensionnel (2D) est souvent considere comme le modele minimal pour les supraconducteurs a haute temperature critique a base d'oxyde de cuivre (SCHT). Sur un reseau carre, ce modele possede les phases qui sont communes a tous les SCHT, la phase antiferromagnetique, la phase supraconductrice et la phase dite du pseudogap. Il n'a pas de solution exacte, toutefois, plusieurs methodes approximatives permettent d'etudier ses proprietes de facon numerique. Les proprietes optiques et de transport sont bien connues dans les SCHT et sont donc de bonne candidates pour valider un modele theorique et aider a comprendre mieux la physique de ces materiaux. La presente these porte sur le calcul de ces proprietes pour le modele de Hubbard 2D a couplage faible ou intermediaire. La methode de calcul utilisee est l'approche auto-coherente a deux particules (ACDP), qui est non-perturbative et inclue l'effet des fluctuations de spin et de charge a toutes les longueurs d'onde. La derivation complete de l'expression de la conductivite dans l'approche ACDP est presentee. Cette expression contient ce qu'on appelle les corrections de vertex, qui tiennent compte des correlations entre quasi-particules. Pour rendre possible le calcul numerique de ces corrections, des algorithmes utilisant, entre autres, des transformees de Fourier rapides et des splines cubiques sont developpes. Les calculs sont faits pour le reseau carre avec sauts aux plus proches voisins autour du point critique antiferromagnetique. Aux dopages plus faibles que le point critique, la conductivite optique presente une bosse dans l'infrarouge moyen a basse temperature, tel qu'observe dans plusieurs SCHT. Dans la resistivite en fonction de la temperature, on trouve un comportement isolant dans le pseudogap lorsque les corrections de vertex sont negligees et metallique lorsqu'elles sont prises en compte. Pres du point critique, la resistivite est lineaire en T a basse temperature et devient

  10. Emergency removal of a grinding wheel embedded in the midface via modified Le Fort I osteotomy.

    PubMed

    Jiang, W H; Wang, X D; Shen, G F

    2011-04-01

    Le Fort I osteotomy is commonly used to rectify craniofacial deformity in orthognathic surgery and it can be used in approaching a cranial base lesion. This technique has not been well documented in craniofacial penetrating trauma. This article describes a case of midface penetrating injury caused by a grinding wheel. A modified Le Fort I osteotomy was used to remove the foreign object. This surgical approach can be safe and effective when removing foreign bodies in the midface. Good access and adequate exposure can be achieved, which facilitate precise foreign body extraction and achieve reasonable cosmetic results.

  11. Le cancer en milieu chirurgical pédiatrique au Togo

    PubMed Central

    Gnassingbe, Komla; Guedenon, Koffi Mawuse; Kanassoua, Kokou; Adabra, Komlan; Kpabi, Kagnimtassou; Akakpo-Numado, Gamedzi Komlatse; Napo-Koura, Gado; Tekou, Hubert

    2014-01-01

    Introduction Le but de ce travail était de relever les aspects épidémiologiques des cancers de l'enfant en milieu chirurgical, décrire les problèmes posés par ces cancers et évaluer les résultats de leur prise en charge Méthodes Il s'agit d'une étude rétrospective analytique sur dossiers de patients âgés de moins de 15 ans pris en charge dans le service de chirurgie pédiatrique pour cancer solide de preuve anatomopathologique entre janvier 1987 et décembre 2010. Jusqu'en 2010, les hôpitaux publics du Togo ne disposaient pas d'imagerie par résonance magnétique ni de la tomodensitométrie. Il n'existe pas de service d'oncologie pédiatrique, ni de radiothérapie au Togo. Depuis quelques années maintenant, le Togo a intégré le Groupe Franco Africain d'oncologie Pédiatrique (GFAOP) et les patients bénéficient gracieusement des antimitotiques pour la prise en charge de certains cancers. Résultats Trente un patients avaient été pris en charge dans le service de chirurgie pédiatrique pour cancer. Parmi eux, il y avait 18 garçons (58,06%) et 15 filles (41,94%). L’âge moyen des patients était de 7,62 ans (extrêmes: 3 mois et 15 ans). Les patients étaient également répartis dans les différentes tranches d’âge. Les circonstances de découverte variaient selon le type de tumeurs. Les tumeurs des tissus mous représentaient 51,61% des cas, les tumeurs germinales 25,81% des cas et les tumeurs osseuses 22,58% des cas. Le délai moyen d’évolution avant la consultation était de 4,6 mois (extrêmes: 2 et 14 mois). Le taux de décès était de 54,84% des cas. Conclusion Les cancers solides de l'enfant sont caractérisés par un retard à la consultation et un plateau à visée diagnostique et thérapeutique très limité entrainant de ce fait une forte mortalité. PMID:25161753

  12. Interpretation des donnees de flux de chaleur et de gravite dans le bouclier Canadien

    NASA Astrophysics Data System (ADS)

    Cheng, Li Zhen

    2000-10-01

    Le champ geothermique du Bouclier Canadien est caracterise par un flux moyen de 41 mW·m-2, qui suggere une production de chaleur moyenne dans la croute comprise entre 0.7 et 0.8 muW·m-3. Le flux de chaleur relativement faible favorise la stabilite du bouclier et lui a permis de resister a la deformation tectonique. Les variations du flux de chaleur a la surface sont dominees par la composition de la croute. Un flux eleve implique generalement une composition felsique et il est d'autant plus faible que la croute devient plus mafique. La production de chaleur en surface n'est pas representative de la production moyenne de la croute. Le flux de chaleur dans le Boucher Canadien ne depend donc pas de la production de chaleur en surface, mais depend de la composition principale de la croute. L'interpretation combinee des donnees geophysiques nous permet de determiner les variations de composition d'echelle crustale a partir desquelles il est possible d'etablir la structure de la croute. L'etude detaillee de l'Orogene de Trans-Hudson et de la Sous-province d'Abitibi a montre que le flux de chaleur, la gravite et la sismique lorsqu'elles sont combinees fournissent des contraintes efficaces pour determiner l'architecture crustale. En general, la croute est trop resistante pour se deformer par fluage, excepte tres localement. Le mode de deformation de la lithosphere continentale depend de la composition et du gradient geothermique. Nous montrons que la lithosphere du Bouclier Canadien demeure principalement fragile jusqu'a une profondeur de plus de 150 km. Une deformation ductile pourrait cependant etre possible localement a la base de la, croute, comme dans la ceinture de Thompson par exemple. Si l'on admet que la lithosphere peut resister a des contraintes allant jusqu'a 20 MPa (taux de deformation 3˙ < 10-15 s-1), l'epaisseur de la lithosphere est de l'ordre de 300 km pour la ceinture de Thompson et est superieure a 300 km pour la sous-province d'Abitibi. La resistance

  13. Spectroscopic and calorimetric investigation of short and intermediate-range structures and energetics of amorphous SiCO, SiCN, and SiBCN polymer-derived ceramics

    NASA Astrophysics Data System (ADS)

    Widgeon, Scarlett J.

    Polymer-derived ceramics (PDCs) are a new class of amorphous ceramics in the Si-B-C-N system that are synthesized by the pyrolysis of silicon-based organic polymers. PDCs are lightweight and are resistant to creep, crystallization, and oxidation at temperatures near 1800 K making them ideal for a variety of high temperature applications. In spite of being X-ray amorphous, these materials display structural heterogeneity at the nanometer length scale. Their structure and resulting properties can be drastically altered by the utilization of preceramic polymers with differing chemistry and architectures. Fundamental understanding of the atomic structure is critical in deciphering the structure-property relationships and ultimately in controlling their properties for specific engineering applications. The short-range atomic structure has been extensively investigated using a variety of techniques, however, the structures at length scales beyond next-nearest neighbors remained highly controversial. Here we report the results of a spectroscopic and calorimetric study of short and intermediate -range structure and energetic of SiOC and SiBCN PDCs derived from a wide variety of precursors. SiOC PDCs with different carbon contents were synthesized from polysiloxane precurors and their structures were studied using high-resolution 13C and 29Si nuclear magnetic resonance (NMR) spectroscopy. The results suggest that these PDCs consists of a continuous mass fractal backbone of corner-shared SiC xO4-x tetrahedral units with "voids" occupied by sp 2-hybridized graphitic carbon. The oxygen-rich SiCxO 4-x units are located at the interior of this backbone with a mass fractal dimension of ~ 2.5, while the carbon-rich units occupy the two-dimensional interface between the backbone and the free carbon nanodomains. Such fractal topology is expected to give rise to unusual mechanical and transport properties characteristic of fractal percolation networks. For example, elastic moduli and

  14. Curiethérapie dans le traitement palliatif du cancer de l’œsophage

    PubMed Central

    Toulba, Ahmedou; Bakkali, Hanae; Boutayeb, Salwa; Kebdani, Tayeb; Ahid, Samir; Benjaafar, Noureddine

    2015-01-01

    Les patients atteints du cancer de l’œsophage ont souvent une maladie localement avancée, la dysphagie est le symptôme majeur chez la plupart de ces patients, plusieurs modalités thérapeutiques ont été utilisées pour améliorer cette dysphagie. Le but de ce travail est d’étudier l'efficacité et la tolérance de la curiethérapie haut débit de dose (HDR) endo-luminale dans le traitement palliatif des cancers de l’œsophage inopérable. Sur une période de 15 ans, l’étude a inclus les patients atteints de cancer de l’œsophage inopérable et/ou métastatique avec une dysphagie, sans extension à l'hypopharynx ou a la trachée et qui ont bénéficié d'une curiethérapie HDR avec ou sans radiothérapie externe à visée palliative. Au total 46 patients ont été inclus dans l’étude, 58,7% étaient des hommes, 42,2% avaient une dysphagie grade 2 et 37,8% étaient aphagiques, 78,6% des patients étaient performance satus PS 2, l'amaigrissement à été trouvé chez 81,4%, la localisation de la tumeur était surtout au niveau du tiers moyen et inférieur dans 97,8%, la hauteur médiane de la tumeur était de 7 cm (5,5-9), le carcinome épidermoïde était le type histologique le plus fréquent chez 31 patients (70,5%). Après un médiane de suivi de 5 mois, l'amélioration de la dysphagie a été retrouvée chez 76% des malades (p1]. L′incidence la plus élevée est observée dans certains pays notamment en Asie et en Afrique, et l′incidence dans les pays développés occidentaux est en augmentation [2]. Selon le registre du cancer de Rabat 2006-2008, le cancer de l’œsophage est rare et constitue 1,5% de tous les cancers chez l'homme [3]. Le taux de survie globale à 5 ans est de 8%, avec 80% des décès liés à l’évolution locale de la maladie [4]. Pour la minorité des patients avec une maladie localisée, le traitement par radiochimiothérapie concomitante avec ou sans chirurgie permet une amélioration de la survie [5]. Plus de 50

  15. The Center for Learning Technologies in Urban Schools (LeTUS) Program[R]. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2012

    2012-01-01

    The "LeTUS" program is a three-year, project-based, technology-integrated middle school science curriculum for grades 6-8. The "LeTUS" program is composed of multiple units, each lasting between eight and ten weeks. Topics include global warming, water and air quality, force and motion, communicable diseases, and ecological…

  16. Pour Une Poesie Chretienne a L'age Baroque: Mysticisme, Heroisme et Feminisme Chez Pierre Le Moyne 1602-1671

    ERIC Educational Resources Information Center

    Fares, Laila

    2012-01-01

    The study constituting the object of this research on one of the best French poets of the 17th century, yet one of the least known, Pierre Le Moyne, aims at restoring this great French poet in his right place, preparing and clearing the way in order to allow further research and stimulate future interest in his works. Pierre Le Moyne is not only…

  17. LeCPK1, a Calcium-Dependent Protein Kinase from Tomato. Plasma Membrane Targeting and Biochemical Characterization1

    PubMed Central

    Rutschmann, Frank; Stalder, Urs; Piotrowski, Markus; Oecking, Claudia; Schaller, Andreas

    2002-01-01

    The cDNA of LeCPK1, a calcium-dependent protein kinase, was cloned from tomato (Lycopersicon esculentum Mill.). LeCPK1 was expressed in Escherichia coli and purified from bacterial extracts. The recombinant protein was shown to be a functional protein kinase using a synthetic peptide as the substrate (syntide-2, Km = 85 μm). Autophosphorylation of LeCPK1 was observed on threonine and serine residues, one of which was identified as serine-439. Kinase activity was shown to be Ca2+ dependent and required the C-terminal, calmodulin-like domain of LeCPK1. Two classes of high- and low-affinity Ca2+-binding sites were observed, exhibiting dissociation constants of 0.6 and 55 μm, respectively. LeCPK1 was found to phosphorylate the regulatory C-terminal domain of the plasma membrane H+-ATPase in vitro. A potential role in the regulation of proton pump activity is corroborated by the apparent colocalization of the plasma membrane H+-ATPase and LeCPK1 in vivo. Upon transient expression in suspension-cultured cells, a C-terminal fusion of LeCPK1 with the green fluorescent protein was targeted to the plasma membrane. Myristoylation of the LeCPK1 N terminus was found to be required for plasma membrane targeting. PMID:12011347

  18. Retour vers le futur: l'expérience des patients et le lien avec la qualité, la sécurité et le rendement financier.

    PubMed

    Cochrane, Bonnie S; Hagins, Mitch; King, John A; Picciano, Gino; McCafferty, Maureen M; Nelson, Brian

    2015-11-01

    Au Canada, l'amélioration de l'expérience des patients est devenue une priorité des politiques de santé. Le perfectionnement et la normalisation des outils et systèmes pour surveiller les mesures de l'expérience des patients augmentent, tandis que la tendance vers une plus grande reddition de compte sur des améliorations durables et abordables se confirme. Pour de nombreux professionnels de la santé, ce phénomène fait foi d'un intérêt renouvelé pour les besoins et priorités fondamentaux des patients, après des décennies où les changements structurels et technologiques ont dominé les programmes de santé. Pour les leaders en santé canadiens, l'amélioration de l'expérience des patients comporte actuellement de grands défis et de belles possibilités. À cet égard, l'expérience des organisations partenaires du groupe Studer au Canada est à la fois pertinente et instructive. Ces organisations ont adopté un modèle, du nom de Evidence-Based Leadership (EBL, ou leadership fondé sur des données probantes), qui favorise et soutient l'harmonisation de l'ensemble des activités et des comportements, conformément à des objectifs organisationnels précis, y compris des améliorations mesurables de l'expérience des patients. Le présent article expose des études de cas d'organisations qui ont adopté l'EBL. Ces organisations ont réalisé des progrès rapides en matière d'indicateurs de l'expérience des patients, ainsi que dans des secteurs essentiels comme les résultats cliniques, la sécurité et le rendement financier. Les données émergentes sur les facteurs et processus qui sous-tendent ces améliorations sont également abordées.

  19. Students' and Teachers' Misapplication of Le Chatelier's Principle: Implications for the Teaching of Chemical Equilibrium.

    ERIC Educational Resources Information Center

    Quilez-Pardo, Juan; Solaz-Portoles, Joan Josep

    1995-01-01

    Study of strategies and procedures of 170 students and 40 teachers when solving chemical equilibrium problems found misconceptions emerging through: misapplication of Le Chatelier's Principle, use of rote-learning recall, incorrect control of variables, limited use of chemical equilibrium law, lack of mastery of chemical equilibrium principles,…

  20. Le Chatelier's Principle: The Effect of Temperature on the Solubility of Solids in Liquids.

    ERIC Educational Resources Information Center

    Brice, L. K.

    1983-01-01

    Provides a rigorous but straightforward thermodynamic treatment of the temperature dependence of the solubility of solids in liquids that is suitable for presentation to undergraduates, suggesting how to approach the qualitative aspects of the subject for freshmen. Considers unsolvated/solvated solutes and Le Chatelier's principle. (JN)

  1. LE[superscript 3]AD Academy Builds Professionalism in Vocational Students

    ERIC Educational Resources Information Center

    Hall, Candace

    2012-01-01

    Principal David Wheeler of Southeastern Regional Vocational-Technical High School founded LE[superscript 3]AD Academy--an innovative program that gives students the opportunity to build and run their own town in teams and with guidance from teachers. The program started in the spring of 2011, and it is innovative in many ways. The students' main…

  2. From Interactive Open Learner Modelling to Intelligent Mentoring: STyLE-OLM and Beyond

    ERIC Educational Resources Information Center

    Dimitrova, Vania; Brna, Paul

    2016-01-01

    STyLE-OLM (Dimitrova 2003 "International Journal of Artificial Intelligence in Education," 13, 35-78) presented a framework for interactive open learner modelling which entails the development of the means by which learners can "inspect," "discuss" and "alter" the learner model that has been jointly…

  3. Une fistule recto-vaginale rentrant dans le cadre d'un syndrome de Currarino

    PubMed Central

    Idrissi, Mounia Lakhdar; Babakhoya, Abdeladim; Bouabdellah, Youssef; Hida, Mostapha

    2011-01-01

    Le syndrome de Currarino (SC) est défini par une triade rassemblant une malformation ano-rectale, une agénésie sacrée et une tumeur pré-sacrée. Nous rapportons le cas d'une fille de 4 ans et demi ayant été admise en consultation de gastro-entérologie pédiatrique pour constipation avec issue de selle à travers un orifice vulvaire. La radiographie du rachis avait montré une agénésie sacrée. Le fistulo-scanner a mis en évidence une fistule recto-vaginale et l'IRM pelvienne a confirmé l'agénésie sacrée et a retrouvé une méningocèle antérieure. La découverte d'une malformation ano-rectale doit faire chercher une autre anomalie de la triade de Currarino. Cette affection, rare, nécessite une prise en charge médico-chirurgicale assez complexe. PMID:22384297

  4. [Roentgendiagnostic of the peritoneovenous drainage after Le Veen for ascitestreatment (author's transl)].

    PubMed

    Vogel, H; Dahm, K

    1978-12-01

    The peritoneovenous drainage after Le Veen offers a possibility of the ascitestreatment. The roentgenexamination showed wrong positions of the katheter as the most frequent cause of dysfunctions. They were regularly combined with venous obstructions. The intraoperativ x-ray diagnostic can fascilate the shunt application and may help to spare a second operation.

  5. Tested Demonstrations: Thermodynamic Changes, Kinetics, Equilibrium, and LeChatelier's Principle.

    ERIC Educational Resources Information Center

    Gilbert, George L., Ed.

    1984-01-01

    Procedures for demonstrating thermodynamic changes, kinetics and reaction mechanisms, equilibrium, and LeChatelier's principle are presented. The only materials needed for these demonstrations are beakers, water, assorted wooden blocks of varying thickness, assorted rubber tubing, and a sponge. The concepts illustrated in each demonstration are…

  6. Heading the ball: a case of a Le Fort II fracture in a football match.

    PubMed

    Akoglu, Ebru; Onur, Ozge; Denizbasi, Arzu; Kosargelir, Mehmet; Akoglu, Haldun; Ibrahim, Abdullah

    2011-03-15

    Facial injuries can impair a patient's ability to eat, speak and interact with others. Severe injuries occur as a result of interpersonal or domestic violence, or in motor vehicle collisions, including those involving motorcycles and all-terrain vehicles. The authors present a case of LeFort II fracture caused by a collision of opponents while heading the ball in a football match.

  7. Le chondrosarcome naso-sinusien: à propos de deux cas et revue de la literature

    PubMed Central

    Touati, Mohamed Mliha; Chihani, Mehdi; Darouassi, Youssef; Lakouichmi, Mohammed; Tourabi, Khalid; Bouaity, Brahim; Ammar, Haddou

    2014-01-01

    Le chondrosarcome est une tumeur maligne très destructrice d'origine cartilagineuse, osseuse et mesnchymateuse. La localisation au niveau de la tête et cou est rare et le siège naso sinusien est encore plus rare. Nous rapportons deux observations de chondrosarcome du sinus maxillaire droit et sphéno ethmoïdale. Le but de notre travail est de montrer à travers ces deux cas cliniques, l'intérêt de la tomodensitométrie et de la résonance magnétique dans la présemption diagnostique en corrélation avec la clinique et l'endoscopie,de discuter le choix de la voix et la technique d'abord chirurgical et la surveillance post opératoire. A travers ces deux observations nous soulignerons les difficultés que pose cette tumeur à l'anatomopathologiste pour différencier entre chondrome et chondrosarcome. PMID:25810801

  8. The clinical and experimental studies of ChanLe Chongji for reducing bleeding after abortion.

    PubMed

    Zhao, R; Ding, Y; Hu, Y

    1999-01-01

    This report presents the results of the clinical and experimental studies conducted to determine the effectiveness of ChanLe Chongji, a Chinese medicine. ChanLe Chongji is believed to promote uterine contraction, stop bleeding, resist bacteria and diminish inflammation. The clinical study was done on 100 women with the following characteristics: under 35 years old; in good health; no contraindication to mifepristone and prostaglandin; normal menses for the past 3 months; not more than 49 days after amenorrhea; intrauterine pregnancy diagnosed by urine human chorionic gonadotropin or ultrasonography. These women were divided into two groups (treated group and control group). An experimental portion of the study included kunming mice weighing 25-30 g and on Wistar rats weighing 180-230 g. The results of the clinical study revealed that the mean bleeding period in the treated group was 8.4 days, while it was 13.3 days in the control group. The mean complete abortion rate was 95% in the treated group and 88% in the control group. A pharmacodynamic test was conducted during the animal experimental portion to comprehend the mechanism of hemostasis. It showed that ChanLe Chongji could increase uterine contraction and stop bleeding; maximal dosage also demonstrated that ChanLe Chongji was safe in clinical use.

  9. 5. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Historic American Buildings Survey, Pierre LeBoutillier and Trusten M. Baldwin, Photographers, April, 1960 INTERIOR DETAIL, NORTHEAST AND SOUTHEAST PARLORS, ORIGINAL MANTEL (LEFT - RADIATOR COVERED). - King of Prussia Inn, U.S. Route 202 (Upper Merion Township), King of Prussia, Montgomery County, PA

  10. Erratum dans le numéro de mai-juin 1988

    NASA Astrophysics Data System (ADS)

    Erratum dans le numéro de mai-juin 1988: Dans l'article sur les étoiles à baryum: p. 74, 2e colonne (après la première formule), il faut lire «A est la masse atomique» au lieu de «nombre atomique»

  11. Reconnaissance Invariante des Formes avec le Filtre de Fourier-Mellin et un Reseau Neuronique

    NASA Astrophysics Data System (ADS)

    Lejeune, Claude

    Le filtre de Fourier-Mellin est applique a un ensemble d'objets pour generer des vecteurs invariants sous translation, rotation et changement d'echelle. C'est la premiere methode permettant d'obtenir ces trois invariants simultanement. Le calcul des vecteurs invariants est fait numeriquement et optiquement. Les vecteurs ainsi obtenus sont utilises comme entrees dans un reseau neuronique backpropagation pour faire la classification des prototypes qui lui sont presentes. Les dimensions des vecteurs invariants sont tres petites par rapport aux objets d'entree et permettent d'utiliser un reseau possedant un nombre restreint de connexions. Il devient possible d'entrai ner le reseau dans des temps relativement courts sur un ordinateur du type PC. Une fois le reseau entrai ne, nous lui presentons des vecteurs invariants provenant d'objets se retrouvant dans l'ensemble d'entrai nement mais ayant subi des rotations et des changements d'echelle. Ce nouveau groupe represente l'ensemble de rappel. La performance de la methode est tres bonne avec des taux de succes superieurs a 85%.

  12. The Potassium-Argon Laser Experiment (KarLE): In Situ Geochronology for Mars and Beyond

    NASA Technical Reports Server (NTRS)

    Cohen, Barbara A.

    2014-01-01

    The search for life in the solar system depends upon discovering the right moments in planetary evolution: when habitable environments existed, when they declined, and when geologic processes operated to preserve traces of life after death. However, an incomplete knowledge of absolute Martian geochronology limits our ability to understand the timing of Martian evolutionary milestones, major climate changes, and stratigraphic epochs [1, 2]. Absolute dating relates these habitability markers to planetarywide geologic, atmospheric, and climate history places, and ties their occurrence to the history of the solar system, especially the Earth-Moon system and the timescale of evolution of life on Earth. KArLE is being developed to anchor the relative timeline of geological events to an absolute chronology that puts Mars into a wider solar system context. KArLE makes its measurements on rock samples that can be obtained by landers or rovers and inserted into a small, mechanically simple chamber. KArLE interrogates the samples using laser-induced breakdown spectrocopy (LIBS), mass spectrometry, and optical imaging. The KArLE experiment is flexible enough to accommodate any partner providing these instrument components, a creative approach that extends the ability of mission payloads to accomplish an additional highly-desirable science measurement for low cost and risk and minimal extra hardware.

  13. Developement of the Potassium-Argon Laser Experiment (KArLE) for In Situ Geochronology

    NASA Technical Reports Server (NTRS)

    Cohen, Barbara A.

    2012-01-01

    Absolute dating of planetary samples is an essential tool to establish the chronology of geological events, including crystallization history, magmatic evolution, and alteration. Thus far, radiometric geochronology of planetary samples has only been accomplishable in terrestrial laboratories on samples from dedicated sample return missions and meteorites. In situ instruments to measure rock ages have been proposed, but none have yet reached TRL 6, because isotopic measurements with sufficient resolution are challenging. We have begun work under the NASA Planetary Instrument Definition and Development Program (PIDDP) to develop the Potassium (K) - Argon Laser Experiment (KArLE), a novel combination of several flight-proven components that will enable accurate KAr isochron dating of planetary rocks. KArLE will ablate a rock sample, measure the K in the plasma state using laser-induced breakdown spectroscopy (LIBS), measure the liberated Ar using quadrupole mass spectrometry (QMS), and relate the two by measuring the volume of the abated pit using a optical methods such as a vertical scanning interferometer (VSI). Our preliminary work indicates that the KArLE instrument will be capable of determining the age of several kinds of planetary samples to 100 Myr, sufficient to address a wide range of geochronology problems in planetary science. Additional benefits derive from the fact that each KArLE component achieves analyses common to most planetary surface missions.

  14. Developing Communication Skills in Deaf Primary School Pupils: Introducing and Evaluating the SmiLE Approach

    ERIC Educational Resources Information Center

    Alton, Sherryn; Herman, Rosalind; Pring, Tim

    2011-01-01

    Many profoundly deaf signers have difficulty communicating with hearing people. This article describes a therapy called "Strategies and Measurable Interaction in Live English" (smiLE; Schamroth and Threadgill, 2007a), an approach used to teach deaf children skills to become successful communicators in real-life situations. This study…

  15. Habitat and nesting of Le Conte's Sparrows in the northern tallgrass prairie

    USGS Publications Warehouse

    Winter, M.; Shaffer, J.A.; Johnson, D.H.; Donovan, T.M.; Svedarsky, W.D.; Jones, P.W.; Euliss, B.R.

    2005-01-01

    Little is known about the breeding biology of the Le Conte's Sparrow (Ammodramus leconteii), probably because of its secretive nature. We provide new information on several aspects of Le Conte's Sparrow breeding biology, including rates of nest parasitism by Brown-headed Cowbirds (Molothrus ater) and potential factors affecting breeding densities and nesting success of the species. Our study was conducted in the tallgrass prairie of northwestern Minnesota and southeastern North Dakota during 1998-2002. Breeding densities varied among years, but this variation was not clearly linked to climatic patterns. Vegetation had some influence on densities of Le Conte's Sparrows; densities were highest in grasslands with moderate amounts of bare ground. Prairie patch size and the percentage of shrubs and trees in the landscape had no recognizable influence on density. Nesting success was highly variable among sites and years and increased slightly with distance from trees. Rates of nest parasitism were low (1 of 50 nests parasitized), and clutch sizes were similar to those of other studies of Le Conte's Sparrows.

  16. Tested Demonstrations: Thermodynamic Changes, Kinetics, Equilibrium, and LeChatelier's Principle.

    ERIC Educational Resources Information Center

    Gilbert, George L., Ed.

    1984-01-01

    Procedures for demonstrating thermodynamic changes, kinetics and reaction mechanisms, equilibrium, and LeChatelier's principle are presented. The only materials needed for these demonstrations are beakers, water, assorted wooden blocks of varying thickness, assorted rubber tubing, and a sponge. The concepts illustrated in each demonstration are…

  17. Coût clinique des retards dans le changement de traitement

    PubMed Central

    Walmsley, Sharon

    2007-01-01

    La prise en charge des patients séropositifs pour le VIH ayant déjà reçu un traitement continue de s’améliorer et d’évoluer. Les nouvelles lignes directrices semblent indiquer que l’objectif du traitement devrait être une suppression virologique maximale. La meilleure façon d’y parvenir consiste à utiliser une combinaison d’agents auxquels le virus sera le plus vraisemblablement sensible et, si possible, des agents appartenant à une nouvelle classe thérapeutique. Les cas discutés démontrent comment l’utilisation d’un schéma thérapeutique puissant à titre de traitement de sauvetage peut avoir de bons résultats virologiques, immunologiques et cliniques. Toutefois, si le traitement de sauvetage retenu n’est pas assez puissant pour atteindre ces objectifs, la durabilité de la réponse est limitée. Ce qu’il faut retenir ici, c’est que ces stratégies devraient reposer sur la puissance du schéma thérapeutique et qu’il ne faut pas retarder l’instauration des agents en cas d’échec d’une stratégie.

  18. Le monde des affaires (The Business World). Teacher's Guide [and] Student's Book.

    ERIC Educational Resources Information Center

    Laing, Martha; Ullmann, Rebecca

    The two components of this publication are the student's book and the teacher's guide to the module, "The Business World" or "Le monde des affaires," which would be suitable for use in an advanced French course or in a class of business French. The teacher's book in French and English has four parts: (1) an explanation of the…

  19. Tuning LeSPL-CNR expression by SlymiR157 affects tomato fruit ripening.

    PubMed

    Chen, Weiwei; Kong, Junhua; Lai, Tongfei; Manning, Kenneth; Wu, Chaoqun; Wang, Ying; Qin, Cheng; Li, Bin; Yu, Zhiming; Zhang, Xian; He, Meiling; Zhang, Pengcheng; Gu, Mei; Yang, Xin; Mahammed, Atef; Li, Chunyang; Osman, Toba; Shi, Nongnong; Wang, Huizhong; Jackson, Stephen; Liu, Yule; Gallusci, Philippe; Hong, Yiguo

    2015-01-19

    In plants, microRNAs (miRNAs) play essential roles in growth, development, yield, stress response and interactions with pathogens. However no miRNA has been experimentally documented to be functionally involved in fruit ripening although many miRNAs have been profiled in fruits. Here we show that SlymiR157 and SlymiR156 differentially modulate ripening and softening in tomato (Solanum lycopersicum). SlymiR157 is expressed and developmentally regulated in normal tomato fruits and in those of the Colourless non-ripening (Cnr) epimutant. It regulates expression of the key ripening gene LeSPL-CNR in a likely dose-dependent manner through miRNA-induced mRNA degradation and translation repression. Viral delivery of either pre-SlymiR157 or mature SlymiR157 results in delayed ripening. Furthermore, qRT-PCR profiling of key ripening regulatory genes indicates that the SlymiR157-target LeSPL-CNR may affect expression of LeMADS-RIN, LeHB1, SlAP2a and SlTAGL1. However SlymiR156 does not affect the onset of ripening, but it impacts fruit softening after the red ripe stage. Our findings reveal that working together with a ripening network of transcription factors, SlymiR157 and SlymiR156 form a critical additional layer of regulatory control over the fruit ripening process in tomato.

  20. Molecular and cellular characterization of the tomato pollen profilin, LePro1

    USDA-ARS?s Scientific Manuscript database

    Profilin is an actin-binding protein involved in the dynamic turnover and restructuring of the actin cytoskeleton in all eukaryotic cells. We previously cloned a profilin gene, designated as LePro1 from tomato pollen. To investigate its biological role, in the present study, We investigated the tem...