Science.gov

Sample records for xvi calorimetric determination

  1. Calorimetric determination of the enthalpy of formation for pyrophyllite

    NASA Astrophysics Data System (ADS)

    Ogorodova, L. P.; Kiseleva, I. A.; Mel'Chakova, L. V.; Vigasina, M. F.; Spiridonov, E. M.

    2011-09-01

    A calorimetric study of the natural pyrophyllite was performed by high-temperature melt calorimetry on a Tian-Calvet calorimeter. Based on experimentally determined in this work for pyrophyllite and gibbsite, as well as previously obtained for corundum and quartz, the total value of the enthalpy increment for the sample heated from room temperature to 973 K and the enthalpy of dissolution at 973 K by Hess's law, the enthalpy of formation of pyrophyllite of Al2[(OH)2/Si4O10] composed of elements was calculated at 298.15 K: Δf H {el/o}(298.15 K) = -5639.8 ± 5.7 kJ/mol.

  2. 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.

  3. Calorimetric determinations and theoretical calculations of polymorphs of thalidomide

    NASA Astrophysics Data System (ADS)

    Lara-Ochoa, F.; Pérez, G. Espinosa; Mijangos-Santiago, F.

    2007-09-01

    The analysis of the thermograms of thalidomide obtained for the two reported polymorphs α and β by differential scanning calorimetry (DSC) shows some inconsistencies that are discussed in the present work. The conception of a new polymorph form, named β ∗, allowed us to explain the observed thermal behavior more satisfactorily. This new polymorph shows enantiotropy with both α and β polymorphs, reflected in the unique endotherm obtained in the DSC-thermograms, when a heating rate of 10 °C/min is applied. Several additional experiments, such as re-melting of both polymorph forms, showed that there is indeed a new polymorph with an endotherm located between the endotherms of α and β. IR, Raman, and powder X-ray permit us to characterize the isolated compound, resulting from the re-melting of both polymorph forms. Mechanical calculations were performed to elucidate the conformations of each polymorph, and ab initio quantum chemical calculations were performed to determine the energy of the more stable conformers and the spatial cell energy for both polymorphs α and β. These results suggested a possible conformation for the newly discovered polymorph β ∗.

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

    NASA Astrophysics Data System (ADS)

    Łapsa, Joanna; Onderka, Bogusław

    2016-05-01

    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.

  5. Kinetics of degradation of diclofenac sodium in aqueous solution determined by a calorimetric method.

    PubMed

    Chadha, R; Kashid, N; Jain, D V S

    2003-09-01

    An isothermal heat conduction microcalorimeter has been used to study the stability of diclofenac sodium both alone and its inclusion complex with beta-cyclodextrin in aqueous solution. The rates of heat evolved during degradation of diclofenac sodium have been measured by a highly sensitive microcalorimetric technique as function of concentration, pH and temperature. The calorimetric accessible data have been incorporated in the equations for determination of rate constants, change in enthalpy and order of reaction. The decomposition of diclofenac sodium both alone and its inclusion complex with beta-cyclodextrin in solution corresponds to a pseudo-first order reaction. The values of rate constants, k's at 338.15 K, (calculated from the variation of heat evolution with the time) for the degradation of diclofenac sodium at pH 5, 6, 7, 8 and its inclusion complex with beta-cyclodextrin at pH 7 are found to be 4.71 x 10(-4), 5.69 x 10(-4), 6.12 x 10(-)4, 6.57 x 10(-4) and 4.26 x 10(-4) h(-1) respectively. There is good agreement between calorimetric determined t(0.5) and literature values. It has been found that beta-cyclodextrin retards the degradation of diclofenac sodium. The kinetic parameters have been calculated for the reaction. The negative entropy of activation suggests the formation of an ordered transition state. PMID:14531458

  6. 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.

  7. 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.

  8. 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.

  9. Calorimetric determination of thermal parameters for the Li/BrCl in SOCl2 (BCX) chemistry

    NASA Technical Reports Server (NTRS)

    Darcy, Eric C.; Kalu, Eric E.; White, Ralph E.

    1990-01-01

    The heat capacity of a Li-BCX DD-cell was found to be dependent on its state of charge by drop calorimetry measurements. The method of drop calorimetry involves measuring the energy (joules) gained or lost from a sample that is transferred from a bath at temperature A to one at temperature B. The thermoneutral potential is defined as the cell potential where the cell electrochemical reactions are neither exothermic nor endothermic. A Hart scientific calorimeter system, Model No. S77XX, designed for heat conduction calorimetry and drop calorimetry was used. Calorimetric analysis yielded a thermoneutral potential of 4.14 volts and a cell heat capacity dependent on the state of charge.

  10. 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.

  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.

    2016-03-01

    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 82≤ A ≤ 132 and a systematic measurement of ^{92} Rb fission yields, as well as investigations of fission yields toward the symmetry region.

  12. Calorimetric determination of the thermoneutral potential for Li/BrCl in SOCl2 (BCX) cells

    NASA Technical Reports Server (NTRS)

    Darcy, Eric C.; Kalu, Eric E.; White, Ralph E.

    1991-01-01

    Proliferation of lithium cells into large modular battery packs are projected for future space applications. Assuring battery design safety while maintaining high energy density requires accurate and precise knowledge of the thermal parameters of the battery cell. Specifically, the thermoneutral potential was determined using heat conduction calorimetry on Li/BrCl in SOCl2 (BCX) DD-cells and compared to measurements obtained on Li/SOCl2 D-cells. Over 20 to 60 C, the Li/BCX cells were found to have a thermoneutral potential significantly higher (near 4.0 volts) than that for the Li/SOCl2 cells tested. The higher heat generation measured during discharge reflects the higher electrochemical polarization observed with the BCX cells.

  13. Approaches to determine the enthalpy of crystallisation, and amorphous content, of lactose from isothermal calorimetric data.

    PubMed

    Dilworth, Sarah E; Buckton, Graham; Gaisford, Simon; Ramos, Rita

    2004-10-13

    Amorphous lactose will crystallise rapidly if its glass transition temperature is reduced below its storage temperature. This is readily achieved by storing samples at ambient temperature and a relative humidity (RH) of greater than 50%. If the sample is monitored in an isothermal microcalorimeter as it crystallises, the heat changes associated with the event can be measured; indeed this is one of the methods used to quantify the amorphous content of powders and formulations. However, variations in the calculation methods used to determine these heat changes have led to discrepancies in the values reported in the literature and frequently make comparison of data from different sources difficult. Data analysis and peak integration software allow the selection and integration of specific areas of complex traces with great reproducibility; this has led to the observation that previously ignored artefacts are in fact of sufficient magnitude to affect calculated enthalpies. In this work a number of integration methodologies have been applied to the analysis of amorphous spray-dried lactose, crystallised under 53 or 75% RH at 25 degrees C. The data allowed the selection of a standard methodology from which reproducible heat changes could be determined. The method was subsequently applied to the analysis of partially amorphous lactose samples (containing 1-100% (w/w) amorphous content) allowing the quantification limit of the technique to be established. It was found that the best approach for obtaining reproducible results was (i) to crystallise under an RH of 53%, because this slowed the crystallisation response allowing better experimental measurement and (ii) to integrate all the events occurring in the ampoule, rather than trying to select only that region corresponding to crystallisation, since it became clear that the processes occurring in the cell overlapped and could not be deconvoluted. The technique was able to detect amorphous contents as low as 1% (w

  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. Use of the BIPM calorimetric and ionometric standards in megavoltage photon beams to determine Wair and Ic

    NASA Astrophysics Data System (ADS)

    Burns, D. T.; Picard, S.; Kessler, C.; Roger, P.

    2014-03-01

    The BIPM graphite calorimeter standard for absorbed dose to water has been used in conjunction with an ionization chamber of known volume and with Monte Carlo simulations of these arrangements to determine the value for Wair in 60Co radiation and in accelerator photon beams up to 25 MV. The results show no evidence for a variation in Wair at the 0.2% level over this energy range. Taking the constancy of Wair as established, the best estimate is Wair = 34.03 eV with a standard uncertainty of 0.21%. Consistent with this analysis, and assuming the use of the grain density in evaluating the stopping power of graphite, is the value Ic = 81.1 eV for the mean excitation energy for graphite, with standard uncertainty 1.8 eV.

  16. 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.

  17. 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.

  18. [Could phimosis have been the cause of sexual difficulties and delayed fertility of Louis XVI (1754-1793)?].

    PubMed

    Androutsos, Georges

    2002-02-01

    The great majority of historians agree that the marriage of Louis XVI and Marie-Antoinette was only consumated seven years after the official ceremony. This delay could have been due to a genital malformation (phimosis) of Louis XVI, a strict religious education, a traumatic childhood and the young age of the two spouses, factors that may have inhibited their sexuality. In this article, the authors try to determine whether Louis XVI was able to overcome his sexual difficulties following an operation (circumcision) or as a result of spontaneous cure. PMID:11980007

  19. PREFACE: Symmetries in Science XVI

    NASA Astrophysics Data System (ADS)

    2014-10-01

    This volume of the proceedings ''Symmetries in Science XVI'' is dedicated to the memory of Miguel Lorente and Allan Solomon who both participated several times in these Symposia. We lost not only two great scientists and colleagues, but also two wonderful persons of high esteem whom we will always remember. Dieter Schuch, Michael Ramek There is a German saying ''all good things come in threes'' and ''Symmetries in Science XVI'', convened July 20-26, 2013 at the Mehrerau Monastery, was our third in the sequel of these symposia since taking it over from founder Bruno Gruber who instigated it in 1988 (then in Lochau). Not only the time seemed to have been perfect (one week of beautiful sunshine), but also the medley of participants could hardly have been better. This time, 34 scientists from 16 countries (more than half outside the European Union) came together to report and discuss their latest results in various fields of science, all related to symmetries. The now customary grouping of renowned experts and talented newcomers was very rewarding and stimulating for all. The informal, yet intense, discussions at ''Gasthof Lamm'' occurred (progressively later) each evening till well after midnight and finally till almost daybreak! However, prior to the opening ceremony and during the conference, respectively, we were informed that Miguel Lorente and Allan Solomon had recently passed away. Both attended the SIS Symposia several times and had many friends among present and former participants. Professor Peter Kramer, himself a long-standing participant and whose 80th birthday commemoration prevented him from attending SIS XVI, kindly agreed to write the obituary for Miguel Lorente. Professors Richard Kerner and Carol Penson (both also former attendees) penned, at very short notice, the tribute to Allan Solomon. The obituaries are included in these Proceedings and further tributes have been posted to our conference website. In 28 lectures and an evening poster

  20. 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.

  1. 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).

  2. 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.

  3. PREFACE: Symmetries in Science XVI

    NASA Astrophysics Data System (ADS)

    2014-10-01

    This volume of the proceedings ''Symmetries in Science XVI'' is dedicated to the memory of Miguel Lorente and Allan Solomon who both participated several times in these Symposia. We lost not only two great scientists and colleagues, but also two wonderful persons of high esteem whom we will always remember. Dieter Schuch, Michael Ramek There is a German saying ''all good things come in threes'' and ''Symmetries in Science XVI'', convened July 20-26, 2013 at the Mehrerau Monastery, was our third in the sequel of these symposia since taking it over from founder Bruno Gruber who instigated it in 1988 (then in Lochau). Not only the time seemed to have been perfect (one week of beautiful sunshine), but also the medley of participants could hardly have been better. This time, 34 scientists from 16 countries (more than half outside the European Union) came together to report and discuss their latest results in various fields of science, all related to symmetries. The now customary grouping of renowned experts and talented newcomers was very rewarding and stimulating for all. The informal, yet intense, discussions at ''Gasthof Lamm'' occurred (progressively later) each evening till well after midnight and finally till almost daybreak! However, prior to the opening ceremony and during the conference, respectively, we were informed that Miguel Lorente and Allan Solomon had recently passed away. Both attended the SIS Symposia several times and had many friends among present and former participants. Professor Peter Kramer, himself a long-standing participant and whose 80th birthday commemoration prevented him from attending SIS XVI, kindly agreed to write the obituary for Miguel Lorente. Professors Richard Kerner and Carol Penson (both also former attendees) penned, at very short notice, the tribute to Allan Solomon. The obituaries are included in these Proceedings and further tributes have been posted to our conference website. In 28 lectures and an evening poster

  4. The VLT-FLAMES Tarantula Survey. XVI. The optical and NIR extinction laws in 30 Doradus and the photometric determination of the effective temperatures of OB stars

    NASA Astrophysics Data System (ADS)

    Maíz Apellániz, J.; Evans, C. J.; Barbá, R. H.; Gräfener, G.; Bestenlehner, J. M.; Crowther, P. A.; García, M.; Herrero, A.; Sana, H.; Simón-Díaz, S.; Taylor, W. D.; van Loon, J. Th.; Vink, J. S.; Walborn, N. R.

    2014-04-01

    Context. The commonly used extinction laws of Cardelli et al. (1989, ApJ, 345, 245) have limitations that, among other issues, hamper the determination of the effective temperatures of O and early B stars from optical and near-infrared (NIR) photometry. Aims: We aim to develop a new family of extinction laws for 30 Doradus, check their general applicability within that region and elsewhere, and apply them to test the feasibility of using optical and NIR photometry to determine the effective temperature of OB stars. Methods: We use spectroscopy and NIR photometry from the VLT-FLAMES Tarantula Survey and optical photometry from HST/WFC3 of 30 Doradus and we analyze them with the software code CHORIZOS using different assumptions, such as the family of extinction laws. Results: We derive a new family of optical and NIR extinction laws for 30 Doradus and confirm its applicability to extinguished Galactic O-type systems. We conclude that by using the new extinction laws it is possible to measure the effective temperatures of OB stars with moderate uncertainties and only a small bias, at least up to E(4405-5495) ~ 1.5 mag. Appendices are available in electronic form at http://www.aanda.org

  5. Thermodynamic properties by non-calorimetric methods. Final report

    SciTech Connect

    Steele, W.V.; Chirico, R.D.; Collier, W.B.; Strube, M.M.; Klots, T.D. |

    1992-12-31

    This research program provided a valuable complement to the experimental programs currently in progress at NIPER for the Advanced Research and Technology Development (AR and TD) and Advanced Exploration and Process Technology (AEPT) divisions of the Department of Energy. These experimental programs are focused on the calorimetric determination of thermodynamic properties of key polynuclear heteroatom-containing aromatic molecules. The project for the Office of Energy Research focused on the non-calorimetric determination of thermodynamic properties through the extension of existing correlation methodologies and through molecular spectroscopy with statistical mechanics. The paper discusses the following studies: Group-contribution approach for polycyclic aromatic hydrocarbons (naphthalene, phenanthrene, anthracene, pyrene, 3-methylphenanthrene, benzoquinolines, biphenyl/hydrogen system); Group-contribution approach for key monocyclic organic compounds; Molecular spectroscopy and statistical mechanics; and Thermophysical property correlations.

  6. Melting enthalpies of mantle peridotite: calorimetric determinations in the system CaO-MgO-Al 2O 3-SiO 2 and application to magma generation

    NASA Astrophysics Data System (ADS)

    Kojitani, Hiroshi; Akaogi, Masaki

    1997-12-01

    High-temperature drop calorimetry in the temperature range of 1398-1785 K was performed for the samples of mixtures of synthetic anorthite (An), diopside (Di), enstatite (En) and forsterite (Fo) with the same compositions as those of primary melts generated at 1.1, 3 and 4 GPa at most 10° above the solidus of anhydrous mantle peridotite in the CaO-MgO-Al 2O 3-SiO 2 system. From the differences between the heat contents ( H T-H 298) of liquid and that of crystal mixture at the liquidus temperature, melting enthalpies of the samples of 1.1, 3 and 4 GPa-primary melt compositions were determined at 1 atm to be 531 ± 39 J · g -1 at 1583 K, 604 ± 21 J · g -1 at 1703 K, 646 ± 21 J · g -1 at 1753 K, respectively. These heat of fusion values suggest that mixing enthalpy of the melt in the An-Di-En-Fo system is approximately zero within the experimental errors when we use the heat of fusion of Fo by Richet et al. (P. Richet, F. Leclerc, L. Benoist, Melting of forsterite and spinel, with implications for the glass transition of Mg 2SiO 4 liquid, Geophys. Res. Lett. 20 (1993) 1675-1678). The measured enthalpies of melting at 1 atm were converted into those for melting reactions which occur under high pressures by correcting enthalpy changes associated with solid-state mineral reactions. Correcting the effects of pressure, temperature and FeO and Na 2O components on the melting enthalpies at 1 atm, heat of fusion values of a representative mantle peridotite just above the solidus under high pressure were estimated to be 590 J at 1.1 GPa and 1523 K, 692 J at 3 GPa and 1773 K, and 807 J at 4 GPa and 1923 K for melting reactions producing liquid of 1 g, with uncertainties of 50 J. By applying these melting enthalpies to a mantle diapir model which generates present MORBs, a potential mantle temperature of 1533 K has been estimated, assuming an eruption temperature of magma of 1473 K.

  7. The Level-0 calorimetric trigger of the NA62 experiment

    NASA Astrophysics Data System (ADS)

    Ammendola, R.; Barbanera, M.; Bizzarri, M.; Bonaiuto, V.; Ceccucci, A.; Checcucci, B.; De Simone, N.; Fantechi, R.; Federici, L.; Fucci, A.; Lupi, M.; Paoluzzi, G.; Papi, A.; Piccini, M.; Ryjov, V.; Salamon, A.; Salina, G.; Sargeni, F.; Venditti, S.

    2016-02-01

    The NA62 experiment at the CERN SPS aims at measuring the branching ratio of the very rare kaon decay K+ → π+ ν bar nu (expected 10-10) with a 10% background. Since an high-intensity kaon beam is required to collect enough statistics, the Level-0 trigger plays a fundamental role in both the background rejection and in the particle identification. The calorimetric trigger collects data from various calorimeters and it is able to identify clusters of energy deposit and determine their position, fine-time and energy. This paper describes the complete hardware commisioning and the setup of the trigger for the 2015 physics data taking.

  8. Measurement of the calorimetric energy scale in MINOS

    SciTech Connect

    Hartnell, Jeffrey J.

    2005-06-01

    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 {Delta}m{sup 2} and sin{sup 2}(2{theta}).

  9. 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.

  10. 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. PMID:11165058

  11. PIXE analysis of Italian ink drawings of the XVI century

    NASA Astrophysics Data System (ADS)

    Zucchiatti, A.; Climent-Font, A.; Enguita, O.; Fernandez-Jimenez, M. T.; Finaldi, G.; Garrido, C.; Matillas, J. M.

    2005-10-01

    The composition of inks in a group of 24 drawings of ten XVI century Italian painters, has been determined by PIXE at the external micro-beam line of the Centro de Micro Análisis de Materiales of the Universidad Autónoma de Madrid. Ink elemental thicknesses have been determined by comparison with a set of certified thin standards. A comprehensive comparison of inks has also been performed by renormalisation of spectra and definition of an ink-to-ink distance. The elemental compositions and the ink-to-ink distances give consistent results that are generally in line with the appearance of the drawings and add relevant instrumental information to the stylistic observation, revealing for example the presence of retouches and additions in different parts of a drawing. Cluster analysis performed on a subgroup of 13 artefacts from the Genoese painter Luca Cambiaso and his school has revealed a partition that separates neatly the work of the master from that of his followers.

  12. 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.

  13. Calorimetric and Magnetic Study of the Holmium

    NASA Astrophysics Data System (ADS)

    Henry, Laurence L.

    Calorimetric measurements have been performed on a series of cubic Laves phase compounds Ho(Co _{rm 1-x}Rh_ {rm x})_2 for x = 0.02, 0.05, 0.08, 0.12, 0.16, and 0.25. The heat capacity data show first-order type peaks at the ferromagnetic transition temperature T_{rm c} for concentrations with x- values between 0.02 and 0.08. For larger concentrations, the peaks at T_{rm c} are much broader and more suggestive of a second-order transition. Utilizing the "s-d" model in conjunction with the specific heat data suggests that the change from first- to second-order in the ferromagnetic transition for x _sp{ ~}{>} 0.10 is due to a reduction in the magnetic exchange interactions between the Ho 4f moments and the cobalt 3d electrons. In addition, the calorimetric data for x <=q 0.16 show another first-order peak at a lower temperature T _{rm sf} which can be associated with a change in the easy magnetization direction of the Ho moments.

  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. Nanoclay modified polycarbonate blend nanocomposites: Calorimetric and mechanical properties

    NASA Astrophysics Data System (ADS)

    Zicans, Janis; Meri, Remo Merijs; Ivanova, Tatjana; Berzina, Rita; Kalnins, Martins; Maksimovs, Roberts

    2014-05-01

    The research is devoted to characterization of polycarbonate (PC)/acrylonitrile-butadiene styrene (ABS) blend nanocomposites in respects to it mechanical and calorimetric properties. It is shown that PC blend with 10wt% of ABS is more suitable for development of polymer-clay nanocomposites than PC blend with 40wt.% of ABS. It is revealed that the greatest modulus and strength increment is observed for PC/10wt.%ABS blend nanocomposites, containing aromatic organomodifier treated clay (Dellite 43B). It is also determined that optimal nanofiller content for the investigated PC/10%ABS blend is 1.5 wt.%. Increase of mechanical characteristics of PC/10wt.%ABS blend nanocomposites is accompanied with the rise of glass transition temperatures of both polymeric phases, particularly that of PC.

  16. New calorimetric all-particle energy spectrum

    NASA Technical Reports Server (NTRS)

    Linsley, J.

    1985-01-01

    Both the maximum size N sub m and the sea level muon size N sub mu have been used separately to find the all-particle energy spectrum in the air shower domain. However the conversion required, whether from N sub m to E or from N sub mu to E, has customarily been carried out by means of calculations based on an assumed cascase model. It is shown here that by combining present data on N sub m and N sub mu spectra with data on: (1); the energy spectrum of air shower muons and (2) the average width of the electron profile, one can obtain empirical values of the N sub m to E and N sub mu to E conversion factors, and an empirical calorimetric all-particle spectrum, in the energy range 2 x 10 to the 6th power E 2 x 10 to the 9th power GeV.

  17. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Standard XVI-Student activities. 36.43 Section 36.43 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR EDUCATION MINIMUM ACADEMIC STANDARDS FOR THE BASIC EDUCATION OF INDIAN CHILDREN AND NATIONAL CRITERIA FOR DORMITORY SITUATIONS Instructional Support § 36.43 Standard XVI—Student activities....

  18. 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.

  19. 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. PMID:18722058

  20. The CALorimetric Electron Telescope, CALET, Mission

    NASA Astrophysics Data System (ADS)

    Torii, Shoji

    We are developing the CALorimetric Electron Telescope, CALET, mission for the Japanese Experiment Module Exposed Facility, JEM-EF, of the International Space Station. Major scientific objectives are to search for nearby cosmic ray sources and dark matter by carrying out a precise measurement of the electrons in GeV 20 TeV and the gamma-rays in 20 MeV TeV. CALET has a unique capability to observe electrons and gamma-rays over 1 TeV since the hadron rejection power is more than 105 and the energy resolution better than a few percent over 100 GeV. The detector consists of an Imaging Calorimeter (IMC) with scintillating fiber belts and tungsten plates, a Total Absorption Calorimeter (TASC) with BGO logs, a Silicon Pixel Array (SIA) and a Scintillator Anti-Coincidence System (SACS). CALET has also a capability to measure protons and nuclei in 10 GeV 1000 TeV, and will have a function to monitor solar activity and gamma-ray bursts with additional instruments. The phase A study has started on a schedule of launch in 2013 by H-II Transfer Vehicle (HTV) for 5 years observation.

  1. ESTIMATION OF BARE-SOIL EVAPORATION USING A CALORIMETRIC APPROACH WITH HEAT FLUX MEASURED AT MULTIPLE DEPTHS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An assumption in calorimetric methods for soil heat flux is that sensible heat terms can be balanced (i.e., if the heat flux is known at one depth, the heat flux at another depth may be determined by monitoring the change in heat storage). Latent heat from water evaporation is assigned to the energy...

  2. A calorimetric investigation of spessartine: Vibrational and magnetic heat capacity

    NASA Astrophysics Data System (ADS)

    Dachs, Edgar; Geiger, Charles A.; Withers, Anthony C.; Essene, Eric J.

    2009-06-01

    The heat capacity ( Cp) of two synthetic spessartine samples (Sps) was measured on 20-30 mg-size samples in the temperature range 2-864 K by relaxation calorimetry (RC) and differential scanning calorimetry (DSC). The polycrystalline spessartine samples were synthesized in two different laboratories at high pressures and temperatures from glass and oxide-mixture starting materials and characterized by X-ray powder diffraction and electron-microprobe analysis. The low-temperature heat capacity data show a prominent lambda transition with a peak at 6.2 K, which is interpreted to be the result of a paramagnetic-antiferromagnetic phase transition. The DSC data around ambient T agree excellently with the RC data and can be represented by the Cp polynomial for T > 250 K: CpSps=610-3060·T-0.5-1.45·107·T-2+1.82·109·T-3. Integration of the low temperature Cp data yields a calorimetric standard entropy for the two different samples of So = 334.6 ± 2.7 J/mol · K and 336.0 ± 2.7 J/mol · K. The preferred standard third-law entropy for spessartine is So = 335.3 ± 3.8 J/mol · K, which is the mean value from the two separate determinations. The lattice (vibrational) heat capacity of spessartine was calculated using the single-parameter phonon dispersion model of Komada and Westrum. The lattice entropy at 298.15 K is Svib298.15=297.7J/mol·K, which represents 89% of the calorimetric entropy. The magnetic heat capacity and entropy of spessartine, Smag, at 298.15 K were also calculated. The Smag of the two samples is 38.7 and 37.4 J/mol · K, which is 87% and 83% of the maximum possible magnetic entropy given by 3Rln6 = 44.7 J/mol · K. Published model-dependent lattice-dynamic calculations of Svib298.15 are analyzed and compared to the experimental data. Using the calorimetrically determined So and the Cp polynomial for spessartine, together with high P- T experimental phase-equilibrium data on Mn 2+-Mg partitioning between garnet and olivine, allows calculation of the

  3. 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.

  4. 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

  5. Anomalous thermodynamic properties of ice XVI and metastable hydrates

    NASA Astrophysics Data System (ADS)

    Yagasaki, Takuma; Matsumoto, Masakazu; Tanaka, Hideki

    2016-02-01

    A new ice polymorph, called ice XVI, has recently been discovered experimentally by extracting the guest molecules from Ne hydrate. The ice and its filled form (clathrate hydrate) have a unique network topology which results in several interesting properties. Here we provide a theoretical method to calculate thermodynamic properties of a semiopen system in equilibrium with guest gas and thus occupancy of the guest can be varied with temperature and pressure. Experimental observations such as the disappearance of negative thermal expansivity and contraction of the host lattice upon encaging guest molecules are well reproduced, and those behaviors are elucidated in terms of the free energy of cage occupation and its temperature and pressure dependence. We propose an application of the method for preparing ice XVI to create metastable clathrate hydrates having intriguing properties with much lower occupancy of guest molecules than that at equilibrium, which otherwise cannot form.

  6. Fructose-selective calorimetric biosensor in flow injection analysis.

    PubMed

    Bhand, Sunil G; Soundararajan, Srimathi; Surugiu-Wärnmark, Ioana; Milea, Jaqueline Simona; Dey, Estera Szwajcer; Yakovleva, Maria; Danielsson, Bengt

    2010-05-23

    A highly selective, interference free biosensor for the measurement of fructose in real syrup samples was developed. The assay is based on the phosphorylation of D(-)fructose to fructose-6-phosphate by hexokinase and subsequent conversion of fructose-6-phosphate to fructose-1,6-biphosphate by fructose-6-phosphate-kinase. The heat liberated in the second reaction is monitored using an enzyme thermistor. The major advantages of this biosensor are rapid and selective measurement of fructose without the need to eliminate glucose and inexpensive FIA-based, mediator-free calorimetric measurement suitable for regular fructose analysis. This method was optimised for parameters, such as pH, ionic strength, interference, operational stability and shelf life. Good and reproducible linearity (0.5-6.0 mM) with a detection limit of 0.12 mM was obtained. Fructose determination in commercial syrup samples and spiked samples confirmed the reliability of this set-up and technique. The biosensor gave reproducible results with good overall stability for continuous measurements over a period of three months besides a useful shelf life of six months. The method could be used for routine fructose monitoring in food samples. PMID:20457296

  7. EDITORIAL: Special issue: CAMOP MOLEC XVI

    NASA Astrophysics Data System (ADS)

    Ascenzi, Daniela; Franceschi, Pietro; Tosi, Paolo

    2007-09-01

    In this special issue of CAMOP/Physica Scripta we would like to present a picture of the state-of-the-art in the field of the dynamics of molecular systems. It contains a collection of papers submitted in association with the most recent MOLEC meeting (MOLEC XVI), which was held in September 2006 in Levico Terme (Italy) to celebrate the 30th anniversary of the MOLEC conference series. The series of biennial European Conferences on the Dynamics of Molecular Systems (MOLEC) started in 1976, when the first meeting was held in Trento (Italy). Successive conferences were organized in Brandbjerg Højskole (Denmark, 1978), Oxford (UK, 1980), Nijmegen (The Netherlands, 1982), Jerusalem (Israel, 1984), Aussois (France, 1986), Assisi (Italy, 1988), Bernkastel-Kues (Germany, 1990), Prague (Czech Republic, 1992), Salamanca (Spain, 1994), Nyborg Strand (Denmark, 1996), Bristol (UK, 1998), Jerusalem (Israel, 2000), Istanbul (Turkey, 2002) and Nunspeet (The Netherlands, 2004). This is the second time that Physica Scripta has hosted a special issue dedicated to MOLEC. The previous issue ( Physica Scripta (2006) 73 C1-C89) was edited by Steven Stolte and Harold Linnartz following the MOLEC 2004 conference. Following the philosophy of CAMOP, we have asked invited speakers to summarize important problems in their research area, with the objective of setting forth the current thinking of leading researchers in atomic, molecular and optical physics. This comprises discussions of open questions, important new applications, new theoretical and experimental approaches and also predictions of where the field is heading. In addition to being authoritative contributions of acknowledged experts, we hope that the papers also appeal to non-specialists as each work contains a clear and broad introduction and references to the accessible literature. The present special issue comprises 17 papers, which are arranged according to the following topics: theoretical and experimental studies of

  8. Calorimetric determination of kQ factors for NE 2561 and NE 2571 ionization chambers in 5 cm × 5 cm and 10 cm × 10 cm radiotherapy beams of 8 MV and 16 MV photons

    NASA Astrophysics Data System (ADS)

    Krauss, Achim; Kapsch, Ralf-Peter

    2007-10-01

    The relative uncertainty of the ionometric determination of the absorbed dose to water, Dw, in the reference dosimetry of high-energy photon beams is in the order of 1.5% and is dominated by the uncertainty of the calculated chamber- and energy-dependent correction factors kQ. In the present investigation, kQ values were determined experimentally in 5 cm × 5 cm and 10 cm × 10 cm radiotherapy beams of 8 MV and 16 MV bremsstrahlung by means of a water calorimeter operated at 4 °C. Ionization chambers of the types NE 2561 and NE 2571 were calibrated directly in the water phantom of the calorimeter. The measurements were carried out at the linear accelerator of the Physikalisch-Technische Bundesanstalt. It is shown that the kQ factor of a single ionization chamber can be measured with a standard uncertainty of less than 0.3%. No significant variations of kQ were found for the different lateral sizes of the radiation fields used in this investigation.

  9. A calorimetric determination of the standard enthalpies of formation of huntite, CaMg3 (CO3)4 , and artinite, Mg2(OH)2 CO3 * 3H2O, and their standard Gibbs free energies of formation

    USGS Publications Warehouse

    Hemingway, Bruce S.; Robie, Richard A.

    1973-01-01

    The enthalpies of formation, ΔH°f, of huntite, CaMg3(CO3)4 , and artinite, Mg2(OH)2CO3 * 3H2O, have been determined by HCl solution calorimetry using a constant-volume isoperibol reaction calorimeter. For the reaction CaO(c) + 3MgO(c) + 4CO2 (g) = CaMg3(CO3)4 (c), the enthalpy change at 298.15 K, ΔH°298 , is -123,203±145 cal mol-1. For the reaction 2MgO(c) + 4H2O(l) + CO2(g)=Mg2(OH)2CO3 * 3H2O(c), we obtained -45,132±100 cal mol-1. These results combined with the standard enthalpies of formation of CaO, MgO, H2O, and CO2 lead to ΔH°298 (huntite) = -1,082,600±375 cal mol-1 and ΔH°298  (artinite) = -698,043±170 cal mol-1. Using recently determined values for the standard entropies of huntite, CaMg3(CO3)4, and artinite, Mg2(OH)2CO3 * 3H2O, and of Mg, Ca, C, O2 , and H2 , we calculate ΔG°f,298 (huntite) = -1,004,707±390 cal mol-1 and ΔG°f,298 (artinite) = -613,924±180 cal mol-1.

  10. Calorimetric support of directional-hemispherical reflection measurements in the infrared spectral range.

    PubMed

    Richter, W; Sarge, S M; Kämmer, F

    1994-03-01

    Measurements of the directional-hemispherical reflectance ρ with the Physikalisch-Technische Bundesanstalt IR sphere reflectometer have been confirmed by calorimetric determination of the absorptance α in the same geometrical conditions (irradiation at 10°, hemispherical reflection). The good agreement of ρ with (1 - α) on both highly reflecting and low-reflecting surfaces indicates that in the mid-IR spectral range the integrating sphere reflectometer is capable of essentially correct reflectance measurements of diffusely reflecting surfaces, with an estimated uncertainty of 0.01 after correction for a small systematic deviation. This capability opens up the possibility of developing IR reflectance standards. PMID:20862150

  11. Thermodynamic properties of chlorite and berthierine derived from calorimetric measurements

    NASA Astrophysics Data System (ADS)

    Blanc, Philippe; Gailhanou, Hélène; Rogez, Jacques; Mikaelian, Georges; Kawaji, Hitoshi; Warmont, Fabienne; Gaboreau, Stéphane; Grangeon, Sylvain; Grenèche, Jean-Marc; Vieillard, Philippe; Fialips, Claire I.; Giffaut, Eric; Gaucher, Eric C.; Claret, F.

    2014-09-01

    In the context of the deep waste disposal, we have investigated the respective stabilities of two iron-bearing clay minerals: berthierine ISGS from Illinois [USA; (Al0.975FeIII0.182FeII1.422Mg0.157Li0.035Mn0.002)(Si1.332Al0.668)O5(OH)4] and chlorite CCa-2 from Flagstaff Hill, California [USA; (Si2.633Al1.367)(Al1.116FeIII0.215Mg2.952FeII1.712Mn0.012Ca0.011)O10(OH)8]. For berthierine, the complete thermodynamic dataset was determined at 1 bar and from 2 to 310 K, using calorimetric methods. The standard enthalpies of formation were obtained by solution-reaction calorimetry at 298.15 K, and the heat capacities were measured by heat-pulse calorimetry. For chlorite, the standard enthalpy of formation is measured by solution-reaction calorimetry at 298.15 K. This is completing the entropy and heat capacity obtained previously by Gailhanou et al. (Geochim Cosmochim Acta 73:4738-4749, 2009) between 2 and 520 K, by using low-temperature adiabatic calorimetry and differential scanning calorimetry. For both minerals, the standard entropies and the Gibbs free energies of formation at 298.15 K were then calculated. An assessment of the measured properties could be carried out with respect to literature data. Eventually, the thermodynamic dataset allowed realizing theoretical calculations concerning the berthierine to chlorite transition. The latter showed that, from a thermodynamic viewpoint, the main factor controlling this transition is probably the composition of the berthierine and chlorite minerals and the nature of the secondary minerals rather than temperature.

  12. A Calorimetric Method for Determination of Heat Capacity of Ceramics for Concentrated Solar Thermal Systems / Skenējošās Kalorimetrijas Metode Siltumietilpības Noteikšanai Saules Kolektoru Keramikā

    NASA Astrophysics Data System (ADS)

    Kalnačs, J.; Grehovs, V.; Mežinskis, G.; Bidermanis, L.

    2013-10-01

    Differential scanning calorimetry was carried out to determine the heat capacity (Cp) of the high temperature resistant ceramic materials to be used as protective coatings for stainless steel tubes of parabolic trough solar collectors in concentrated solar power (CSP) systems. The Ср(Т) measurements and calculations were performed at continuous scanning in the temperature range 20-800 °С. In the work, calibration curves have been derived for conversion of measuring units from mcV into mW. To achieve a better repeatability of measurements, methods for stabilization of the thermal contact between the sample-containing vessel and the probe have been developed. The Ср(Т) dependence was obtained for different ceramic materials. Rakstā izklāstīta izstrādātā metodika keramikas un emalju siltumietilpības noteikšanai pēc diferenciālās skenējošās kalorimetrijas mērījumiem. Parādīta virkne traucējošo faktoru kalibrēšanas līknes un mērījumu veikšanai, piedāvātas metodes to samazināšanai vai novēršanai, precīzāku rezultātu ieguvei. Noteikta siltumietilpības atkarība no temperatūras virknei emalju, kas var tikt izmantotas saules siltuma kolektoros, kā aizsargpārklājumi. Parādīta siltumietilpības noteikšanas atkārtojamības atkarība no siltuma kontakta. Izstrādāta metode termiskā kontakta stabilizācijai. Virknei emalju noteikta siltumietilpības atkarība no temperatūras diapazonā 20 - 800°С.

  13. Thermodynamic properties by non-calorimetric methods. Progress report, August 1, 1988--July 31, 1989

    SciTech Connect

    Steele, W.V.; Chirico, R.D.; Collier, W.B.; Strube, M.M. |

    1989-12-31

    This three year research program provides a valuable complement to the experimental programs currently in progress at NIPER for the Advanced Research and Technology Development (AR and TD) and Advanced Exploration and Process Technology (AEPT) divisions of the Department of Energy. These experimental programs are focused on the calorimetric determination of thermodynamic properties of key polynuclear heteroatom-containing aromatic molecules. This project for the Office of Energy Research focuses on the non-calorimetric determination of thermodynamic properties through the extension of existing correlation methodologies and through molecular spectroscopy with statistical mechanics. The paper discusses progress in three areas: (1) Improvement of thermochemical and thermophysical property predictions via enhancement of group-contribution methods using two approaches, namely, development and improvement of group-contribution parameters via correlations involving the expanded modern thermodynamics data base and development of group-contribution parameters via molecular spectroscopy and statistical mechanics of key monocyclic organic compounds; (2) Molecular spectroscopy and statistical mechanics: equipment development and developments in interpretation and assignment of spectra; and (3) Thermophysical property correlations.

  14. Planck 2013 results. XVI. Cosmological parameters

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bock, J. J.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bridges, M.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cappellini, B.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.-R.; Chen, X.; Chiang, H. C.; Chiang, L.-Y.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dolag, K.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dunkley, J.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Gaier, T. C.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Haissinski, J.; Hamann, J.; Hansen, F. K.; Hanson, D.; Harrison, D.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hou, Z.; Hovest, W.; Huffenberger, K. M.; Jaffe, A. H.; Jaffe, T. R.; Jewell, J.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Laureijs, R. J.; Lawrence, C. R.; Leach, S.; Leahy, J. P.; Leonardi, R.; León-Tavares, J.; Lesgourgues, J.; Lewis, A.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Meinhold, P. R.; Melchiorri, A.; Melin, J.-B.; Mendes, L.; Menegoni, E.; Mennella, A.; Migliaccio, M.; Millea, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; O'Dwyer, I. J.; Osborne, S.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, D.; Pearson, T. J.; Peiris, H. V.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Platania, P.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Spencer, L. D.; Starck, J.-L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Tuovinen, J.; Türler, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; White, M.; White, S. D. M.; Wilkinson, A.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-11-01

    This paper presents the first cosmological results based on Planck measurements of the cosmic microwave background (CMB) temperature and lensing-potential power spectra. We find that the Planck spectra at high multipoles (ℓ ≳ 40) are extremely well described by the standard spatially-flat six-parameter ΛCDM cosmology with a power-law spectrum of adiabatic scalar perturbations. Within the context of this cosmology, the Planck data determine the cosmological parameters to high precision: the angular size of the sound horizon at recombination, the physical densities of baryons and cold dark matter, and the scalar spectral index are estimated to be θ∗ = (1.04147 ± 0.00062) × 10-2, Ωbh2 = 0.02205 ± 0.00028, Ωch2 = 0.1199 ± 0.0027, and ns = 0.9603 ± 0.0073, respectively(note that in this abstract we quote 68% errors on measured parameters and 95% upper limits on other parameters). For this cosmology, we find a low value of the Hubble constant, H0 = (67.3 ± 1.2) km s-1 Mpc-1, and a high value of the matter density parameter, Ωm = 0.315 ± 0.017. These values are in tension with recent direct measurements of H0 and the magnitude-redshift relation for Type Ia supernovae, but are in excellent agreement with geometrical constraints from baryon acoustic oscillation (BAO) surveys. Including curvature, we find that the Universe is consistent with spatial flatness to percent level precision using Planck CMB data alone. We use high-resolution CMB data together with Planck to provide greater control on extragalactic foreground components in an investigation of extensions to the six-parameter ΛCDM model. We present selected results from a large grid of cosmological models, using a range of additional astrophysical data sets in addition to Planck and high-resolution CMB data. None of these models are favoured over the standard six-parameter ΛCDM cosmology. The deviation of the scalar spectral index from unity isinsensitive to the addition of tensor modes and to

  15. Micro-calorimetric sensor for trace explosive particle detection

    NASA Astrophysics Data System (ADS)

    Olsen, Jesper K.; Greve, Anders; Privorotskaya, N.; Senesac, L.; Thundat, T.; King, W. P.; Boisen, A.

    2010-04-01

    A micro differential thermal analysis (DTA) system is used for detection of trace explosive particles. The DTA system consists of two silicon micro chips with integrated heaters and temperature sensors. One chip is used for reference and one for the measurement sample. The sensor is constructed as a small silicon nitride bridge incorporating heater elements and a temperature measurement resistor. In this manuscript the DTA system is described and tested by measuring calorimetric response of DNT (2,4-Dinitrotoluene). The design of the senor is described and the temperature uniformity investigated using finite element modelings and Raman temperature measurements. The functionality is tested using two different kinds of explosive deposition techniques and calorimetric responses are obtained. Under the framework of the Xsense project at the Technical University of Denmark (DTU) which combines four independent sensing techniques, these micro DNT sensors will be included in handheld explosives detectors with applications in homeland security and landmine clearance.

  16. 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.

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

    DOE PAGESBeta

    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 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

  18. 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

  19. A no-calorimetric method for measuring SAR in MRI

    NASA Astrophysics Data System (ADS)

    Romano, Rocco; Acernese, Fausto; Barone, Fabrizio

    2011-04-01

    During an MR procedure, the patient absorbs a portion of the transmitted RF energy, which may result in tissue heating and other adverse effects, such as alterations in visual, auditory and neural functions. The Specific Absorption Rate (SAR), in W/kg, is the RF power absorbed per unit mass of tissue and is one of the most important parameters related with thermal effects and acts as a guideline for MRI safety. Strict limits to the SAR levels are imposed by patient safety international regulations (CEI - EN 60601 - 2 - 33) and SAR measurements are required in order to verify its respect. The recommended methods for mean SAR measurement are quite problematic and often require a maintenance man intervention and long stop machine. For example, in the CEI recommended pulse energy method, the presence of a maintenance man is required in order to correctly connect the required instrumentation; furthermore, the procedure is complex and requires remarkable processing and calculus. Simpler are the calorimetric methods, also if in this case long acquisition times are required in order to have significant temperature variations and accurate heat capacity knowledge (CEI - EN 60601 - 2 - 33). The phase transition method is a new no-calorimetric method to measure SAR in MRI which has the advantages to be very simple and to overcome all the typical calorimetric method problems. It does not require in gantry temperature measurements, any specific heat or heat capacity knowledge, but only mass and time measurement. On the other hand, it is necessary to establish if all deposited power SAR can be considered acquired and measured. In this paper, that will be shown.

  20. 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.

  1. A calorimetric study on interactions of colchicine with human serum albumin

    NASA Astrophysics Data System (ADS)

    Zhao, Qiang; Xu, Xiang-Yu; Sun, Xiang-Jun; Liu, Min; Sun, De-Zhi; Li, Lin-Wei

    2009-08-01

    Interaction of colchicine (COL) with human serum albumin (HSA) in buffer solutions (pH 7.2) has been investigated by isothermal titration calorimetry (ITC) combined with circular dichroism (CD) and UV-vis spectra. Heats of the interactions have been determined at 298.15 K. Based on the calorimetric data and reasonable suppositions for the bio-macromolecule - ligand binding process, the equilibrium constants, standard changes of enthalpy, entropy and Gibbs free energy of the processes are obtained. The results show that there are two classes of ligand binding sites. The first-class binding is mainly driven by entropy, while the second-class binding is synergistically driven by entropy and enthalpy. Circular dichroism (CD) and UV-vis spectra show that COL can change the secondary structure of HSA molecule.

  2. 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.

  3. 20 CFR 408.930 - Are title II and title XVI benefits subject to adjustment to recover title VIII overpayments?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Underpayments and Overpayments Adjustment of Title II Benefits § 408.930 Are title II and title XVI benefits subject to adjustment to... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Are title II and title XVI benefits...

  4. 20 CFR 408.930 - Are title II and title XVI benefits subject to adjustment to recover title VIII overpayments?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Underpayments and Overpayments Adjustment of Title II Benefits § 408.930 Are title II and title XVI benefits subject to adjustment to... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Are title II and title XVI benefits...

  5. 20 CFR 408.930 - Are title II and title XVI benefits subject to adjustment to recover title VIII overpayments?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Underpayments and Overpayments Adjustment of Title II Benefits § 408.930 Are title II and title XVI benefits subject to adjustment to... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Are title II and title XVI benefits...

  6. 20 CFR 408.930 - Are title II and title XVI benefits subject to adjustment to recover title VIII overpayments?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Underpayments and Overpayments Adjustment of Title II Benefits § 408.930 Are title II and title XVI benefits subject to adjustment to... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Are title II and title XVI benefits...

  7. 20 CFR 408.930 - Are title II and title XVI benefits subject to adjustment to recover title VIII overpayments?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Underpayments and Overpayments Adjustment of Title II Benefits § 408.930 Are title II and title XVI benefits subject to adjustment to... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Are title II and title XVI benefits...

  8. Calorimetric approach for 3D dosimetry of high intensity therapeutic electron beams

    NASA Astrophysics Data System (ADS)

    Lamanna, E.; Fiorillo, A. S.; Vena, R.; Berdondini, A.; Bettuzzi, M.; Brancaccio, R.; Casali, F.; Morigi, M. P.; Bilokon, H.; Barca, G.; Castrovillari, F.; Siaka, Y. F. T.

    2009-12-01

    The technique of High Dose Rate Intra-Operative Radiation Therapy (HDR-IORT) consists in the delivery of irradiation immediately after the removal of a cancerous mass, where the same incision is used to focalize the radiation to the tumour bed. Given its particular characteristics, IORT requires dose measurements that are different from those requested in external radiotherapy treatments. The main reason lies in the fact that in this case a single high dose must be delivered to a target volume whose extension and depth will be determined directly during the operation. Because of this peculiar characteristics, until now there is not a dosimetric system able to detect the electron beam giving at once a realtime response and an extensive spatial measure of the absorbed dose. Within the framework of a research project of the INFN (Italian National Institute of Nuclear Physics), we proposed a new system to overcome the problems, Dosiort. The final set-up is a solid phantom having a density approximately 1 g/cm3 with sensitive layers of scintillating fibres at fixed positions in a calorimetric configuration for the containment of electrons of energy 4-12 MeV. The prototype will be able to define the physical and geometrical characteristics of the electron beam (energy, isotropy, homogeneity, etc) and to measure the parameters needed to select the energy, the intensity and the Monitor Units (MU) for the exposition: percentage Depth Dose; beam profiles; isodose curves; values of dose per MU. In this work we present the results obtained by using two orthogonal layers of the calorimetric phantom Dosiort, in particular we report the measurement of the dynamic range of the read-out system and the first qualitative study of the results which can be extracted from the measurements taken in a test beam.

  9. 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.

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

    PubMed

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

    2015-12-01

    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

  11. A TEMPORAL MAP IN GEOSTATIONARY ORBIT: THE COVER ETCHING ON THE EchoStar XVI ARTIFACT

    SciTech Connect

    Weisberg, Joel M.; Paglen, Trevor

    2012-10-01

    Geostationary satellites are unique among orbital spacecraft in that they experience no appreciable atmospheric drag. After concluding their respective missions, geostationary spacecraft remain in orbit virtually in perpetuity. As such, they represent some of human civilization's longest lasting artifacts. With this in mind, the EchoStar XVI satellite, to be launched in fall 2012, will play host to a time capsule intended as a message for the deep future. Inspired in part by the Pioneer Plaque and Voyager Golden Records, the EchoStar XVI Artifact is a pair of gold-plated aluminum jackets housing a small silicon disk containing 100 photographs. The Cover Etching, the subject of this paper, is etched onto one of the two jackets. It is a temporal map consisting of a star chart, pulsar timings, and other information describing the epoch from which EchoStar XVI came. The pulsar sample consists of 13 rapidly rotating objects, 5 of which are especially stable, having spin periods <10 ms and extremely small spin-down rates. In this paper, we discuss our approach to the time map etched onto the cover and the scientific data shown on it, and we speculate on the uses that future scientists may have for its data. The other portions of the EchoStar XVI Artifact will be discussed elsewhere.

  12. The ISLANDS Project. I. Andromeda XVI, An Extremely Low Mass Galaxy Not Quenched by Reionization

    NASA Astrophysics Data System (ADS)

    Monelli, Matteo; Martínez-Vázquez, Clara E.; Bernard, Edouard J.; Gallart, Carme; Skillman, Evan D.; Weisz, Daniel R.; Dolphin, Andrew E.; Hidalgo, Sebastian L.; Cole, Andrew A.; Martin, Nicolas F.; Aparicio, Antonio; Cassisi, Santi; Boylan-Kolchin, Michael; Mayer, Lucio; McConnachie, Alan; McQuinn, Kristen B. W.; Navarro, Julio F.

    2016-03-01

    Based on data aquired in 13 orbits of Hubble Space Telescope time, we present a detailed evolutionary history of the M31 dSph satellite Andromeda XVI, including its lifetime star formation history (SFH), the spatial distribution of its stellar populations, and the properties of its variable stars. And XVI is characterized by prolonged star formation activity from the oldest epochs until star formation was quenched ˜6 Gyr ago, and, notably, only half of the mass in stars of And XVI was in place 10 Gyr ago. And XVI appears to be a low-mass galaxy for which the early quenching by either reionization or starburst feedback seems highly unlikely, and thus it is most likely due to an environmental effect (e.g., an interaction), possibly connected to a late infall in the densest regions of the Local Group. Studying the SFH as a function of galactocentric radius, we detect a mild gradient in the SFH: the star formation activity between 6 and 8 Gyr ago is significantly stronger in the central regions than in the external regions, although the quenching age appears to be the same, within 1 Gyr. We also report the discovery of nine RR Lyrae (RRL) stars, eight of which belong to And XVI. The RRL stars allow a new estimate of the distance, (m - M)0 = 23.72 ± 0.09 mag, which is marginally larger than previous estimates based on the tip of the red giant branch. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #13028.

  13. Formation and properties of ice XVI obtained by emptying a type sII clathrate hydrate.

    PubMed

    Falenty, Andrzej; Hansen, Thomas C; Kuhs, Werner F

    2014-12-11

    Gas hydrates are ice-like solids, in which guest molecules or atoms are trapped inside cages formed within a crystalline host framework (clathrate) of hydrogen-bonded water molecules. They are naturally present in large quantities on the deep ocean floor and as permafrost, can form in and block gas pipelines, and are thought to occur widely on Earth and beyond. A natural point of reference for this large and ubiquitous family of inclusion compounds is the empty hydrate lattice, which is usually regarded as experimentally inaccessible because the guest species stabilize the host framework. However, it has been suggested that sufficiently small guests may be removed to leave behind metastable empty clathrates, and guest-free Si- and Ge-clathrates have indeed been obtained. Here we show that this strategy can also be applied to water-based clathrates: five days of continuous vacuum pumping on small particles of neon hydrate (of structure sII) removes all guests, allowing us to determine the crystal structure, thermal expansivity and limit of metastability of the empty hydrate. It is the seventeenth experimentally established crystalline ice phase, ice XVI according to the current ice nomenclature, has a density of 0.81 grams per cubic centimetre (making it the least dense of all known crystalline water phases) and is expected to be the stable low-temperature phase of water at negative pressures (that is, under tension). We find that the empty hydrate structure exhibits negative thermal expansion below about 55 kelvin, and that it is mechanically more stable and has at low temperatures larger lattice constants than the filled hydrate. These observations attest to the importance of kinetic effects and host-guest interactions in clathrate hydrates, with further characterization of the empty hydrate expected to improve our understanding of the structure, properties and behaviour of these unique materials. PMID:25503235

  14. Formation and properties of ice XVI obtained by emptying a type sII clathrate hydrate

    NASA Astrophysics Data System (ADS)

    Falenty, Andrzej; Hansen, Thomas C.; Kuhs, Werner F.

    2014-12-01

    Gas hydrates are ice-like solids, in which guest molecules or atoms are trapped inside cages formed within a crystalline host framework (clathrate) of hydrogen-bonded water molecules. They are naturally present in large quantities on the deep ocean floor and as permafrost, can form in and block gas pipelines, and are thought to occur widely on Earth and beyond. A natural point of reference for this large and ubiquitous family of inclusion compounds is the empty hydrate lattice, which is usually regarded as experimentally inaccessible because the guest species stabilize the host framework. However, it has been suggested that sufficiently small guests may be removed to leave behind metastable empty clathrates, and guest-free Si- and Ge-clathrates have indeed been obtained. Here we show that this strategy can also be applied to water-based clathrates: five days of continuous vacuum pumping on small particles of neon hydrate (of structure sII) removes all guests, allowing us to determine the crystal structure, thermal expansivity and limit of metastability of the empty hydrate. It is the seventeenth experimentally established crystalline ice phase, ice XVI according to the current ice nomenclature, has a density of 0.81 grams per cubic centimetre (making it the least dense of all known crystalline water phases) and is expected to be the stable low-temperature phase of water at negative pressures (that is, under tension). We find that the empty hydrate structure exhibits negative thermal expansion below about 55 kelvin, and that it is mechanically more stable and has at low temperatures larger lattice constants than the filled hydrate. These observations attest to the importance of kinetic effects and host-guest interactions in clathrate hydrates, with further characterization of the empty hydrate expected to improve our understanding of the structure, properties and behaviour of these unique materials.

  15. Estimation of the diversity between DNA calorimetric profiles, differential melting curves and corresponding melting temperatures.

    PubMed

    Chang, Chun-Ling; Fridman, Alexander S; Grigoryan, Inessa E; Galyuk, Elena N; Murashko, Oleg N; Hu, Chin-Kun; Lando, Dmitri Y

    2016-11-01

    The Poland-Fixman-Freire formalism was adapted for modeling of calorimetric DNA melting profiles, and applied to plasmid pBR 322 and long random sequences. We studied the influence of the difference (HGC -HAT ) between the helix-coil transition enthalpies of AT and GC base pairs on the calorimetric melting profile and on normalized calorimetric melting profile. A strong alteration of DNA calorimetrical profile with HGC -HAT was demonstrated. In contrast, there is a relatively slight change in the normalized profiles and in corresponding ordinary (optical) normalized differential melting curves (DMCs). For fixed HGC -HAT , the average relative deviation (S) between DMC and normalized calorimetric profile, and the difference between their melting temperatures (Tcal -Tm ) are weakly dependent on peculiarities of the multipeak fine structure of DMCs. At the same time, both the deviation S and difference (Tcal -Tm ) enlarge with the temperature melting range of the helix-coil transition. It is shown that the local deviation between DMC and normalized calorimetric profile increases in regions of narrow peaks distant from the melting temperature. PMID:27422497

  16. Calorimetric and theoretical study of the interaction between some saccharides and sodium halide in water.

    PubMed

    Zhuo, Kelei; Fu, Yingyi; Bai, Guangyue; Wang, Jianji; Yan, Haike; Wang, Hanqing

    2012-08-23

    Dilution enthalpies and mixing enthalpies of sodium halide and some saccharides (glucose, galactose, xylose, arabinose, fructose, and sucrose) in aqueous solution were determined by calorimetric measurements at 298.15 K. The values were used to determine enthalpic pair interaction parameters. Combined with Gibbs energy pair parameters, entropic pair interaction parameters were also obtained. Theoretical calculations at the B3LYP/6-311++G(d,p) level were carried out to provide the information of structures and thermodynamic functions. The information reveals the thermodynamic essence of the interactions between sodium halide and saccharides in aqueous solutions. The experimental results and theoretical calculations show that the sign of enthalpic pair interaction parameter 2υh(ES) is determined by the direct interaction between saccharides and ions, whereas the difference in value of 2υh(ES) for different saccharides or electrolytes depends on the partial dehydration of saccharides or anions in aqueous solution. The difference in value of entropic pair interaction parameters depends partly on the different dominant interactions in the process of partial dehydration of saccharides or ions. An enthalpy-entropy compensation relationship was observed for the sodium bromide-aldopyranose-water systems. Remarkably, it can be conjectured that the hydration entropy of glucose is lower than for other monosaccharides. Perhaps it is one of the reasons why glucose plays an important role in living organisms rather than other monosaccharides. PMID:22779908

  17. Differential scanning calorimetric studies of nickel titanium rotary endodontic instruments.

    PubMed

    Brantley, W A; Svec, T A; Iijima, M; Powers, J M; Grentzer, T H

    2002-08-01

    Differential scanning calorimetric (DSC) analyses were performed between -130 degrees and 100 degrees C on specimens prepared from nickel-titanium (NiTi) rotary endodontic instruments: ProFile (n = 5), Lightspeed (n = 4), and Quantec (n = 3). The ProFile and Lightspeed instruments were in the as-received condition, whereas the Quantec instruments were randomly selected from a dental clinic and had unknown history. The DSC plots showed that the ProFile and Lightspeed instruments analyzed had the superelastic NiTi property, with an austenite-finish (Af) temperature of approximately 25 degrees C. Differences in DSC plots for the ProFile instruments and the starting wire blanks (n = 2) were attributed to the manufacturing process. The phase transformation behavior when the specimens were heated and cooled between -130 degrees and 100 degrees C, the temperature ranges for the phase transformations, and the resulting enthalpy changes were similar to those previously reported for nickel-titanium orthodontic wires having superelastic characteristics or shape memory behavior in the oral environment. The experiments demonstrated that DSC is a powerful tool for materials characterization of these rotary instruments, providing direct information not readily available from other analytical techniques about the NiTi phases present, which are fundamentally responsible for their clinical behavior. PMID:12184415

  18. Huwentoxin-XVI, an analgesic, highly reversible mammalian N-type calcium channel antagonist from Chinese tarantula Ornithoctonus huwena.

    PubMed

    Deng, Meichun; Luo, Xuan; Xiao, Yucheng; Sun, Zhenghua; Jiang, Liping; Liu, Zhonghua; Zeng, Xiongzhi; Chen, Hanchun; Tang, Jianhua; Zeng, Weimin; Songping Liang

    2014-04-01

    N-type calcium channels play important roles in the control of neurotransmission release and transmission of pain signals to the central nervous system. Their selective inhibitors are believed to be potential drugs for treating chronic pain. In this study, a novel neurotoxin named Huwentoxin-XVI (HWTX-XVI) specific for N-type calcium channels was purified and characterized from the venom of Chinese tarantula Ornithoctonus huwena. HWTX-XVI is composed of 39 amino acid residues including six cysteines that constitute three disulfide bridges. HWTX-XVI could almost completely block the twitch response of rat vas deferens to low-frequency electrical stimulation. Electrophysiological assay indicated that HWTX-XVI specifically inhibited N-type calcium channels in rat dorsal root ganglion cells (IC50 ∼60 nM). The inhibitory effect of HWTX-XVI on N-type calcium channel currents was dose-dependent and similar to that of CTx-GVIA and CTx-MVIIA. However, the three peptides exhibited markedly different degrees of reversibility after block. The toxin had no effect on voltage-gated T-type calcium channels, potassium channels or sodium channels. Intraperitoneal injection of the toxin HWTX-XVI to rats elicited significant analgesic responses to formalin-induced inflammation pain. Toxin treatment also changed withdrawal latency in hot plate tests. Intriguingly, we found that intramuscular injection of the toxin reduced mechanical allodynia induced by incisional injury in Von Frey test. Thus, our findings suggest that the analgesic potency of HWTX-XVI and its greater reversibility could contribute to the design of a novel potential analgesic agent with high potency and low side effects. PMID:24467846

  19. Calorimetric method for adjusting the mass of culture fluid in a bioreactor

    NASA Astrophysics Data System (ADS)

    Kotelnikov, G. V.; Moiseyeva, S. P.; Krayev, V. P.

    1998-05-01

    A new calorimetric method for adjusting the mass of culture fluid in a bioreactor and the results of its experimental testing are described. The method is based on constant heat capacity of liquids in the presence of disturbing factors accompanying biotechnology processes. A new measuring parameter independent of thermal noise induced by the stirrer, the flow of fluids, chemical and physical interactions of substances in the bioreactor was used for adjusting the mass of culture fluid. This parameter is Ph, the power increment in the heater under steady-state conditions of heating the bioreactor. The scanning calorimetry principle was used to make the measurements. It was shown that it is necessary to provide a constant heating rate V for the bioreactor and a high-speed response of the automated control system (ACS) for bioreactor temperature. The ACS developed on the base of the dynamic error and transient response h(t) calculated by the inverse Laplace transform with the use of the closed-loop transfer function gives V=const and the control time of about several seconds. The experimental data reported show the adjustment of the mass of culture fluid in a 3 l bioreactor with an error of no more than 10 g. This enables an accurate evaluation of the biomass amount in the bioreactor, specific growth rate, and other growth parameters determined using specific growth rate.

  20. A calorimetric study of the hydrolysis and peroxide complex formation of the uranyl(VI) ion.

    PubMed

    Zanonato, Pier Luigi; Di Bernardo, Plinio; Grenthe, Ingmar

    2014-02-14

    The enthalpies of reaction for the formation of uranyl(vi) hydroxide {[(UO2)2(OH)2](2+), [(UO2)3(OH)4](2+), [(UO2)3(OH)5](+), [(UO2)3(OH)6](aq), [(UO2)3(OH)7](-), [(UO2)3(OH)8](2-), [(UO2)(OH)3](-), [(UO2)(OH)4](2-)} and peroxide complexes {[UO2(O2)(OH)](-) and [(UO2)2(O2)2(OH)](-)} have been determined from calorimetric titrations at 25 °C in a 0.100 M tetramethyl ammonium nitrate ionic medium. The hydroxide data have been used to test the consistency of the extensive thermodynamic database published by the Nuclear Energy Agency (I. Grenthe, J. Fuger, R. J. M. Konings, R. J. Lemire, A. B. Mueller, C. Nguyen-Trung and H. Wanner, Chemical Thermodynamics of Uranium, North-Holland, Amsterdam, 1992 and R. Guillaumont, T. Fanghänel, J. Fuger, I. Grenthe, V. Neck, D. J. Palmer and M. R. Rand, Update on the Chemical Thermodynamics of Uranium, Neptunium, Plutonium, Americium and Technetium, Elsevier, Amsterdam, 2003). A brief discussion is given about a possible structural relationship between the trinuclear complexes [(UO2)3(OH)n](6-n), n = 4-8. PMID:24301256

  1. Genomic analysis of the blood attributed to Louis XVI (1754-1793), king of France.

    PubMed

    Olalde, Iñigo; Sánchez-Quinto, Federico; Datta, Debayan; Marigorta, Urko M; Chiang, Charleston W K; Rodríguez, Juan Antonio; Fernández-Callejo, Marcos; González, Irene; Montfort, Magda; Matas-Lalueza, Laura; Civit, Sergi; Luiselli, Donata; Charlier, Philippe; Pettener, Davide; Ramírez, Oscar; Navarro, Arcadi; Himmelbauer, Heinz; Marquès-Bonet, Tomàs; Lalueza-Fox, Carles

    2014-01-01

    A pyrographically decorated gourd, dated to the French Revolution period, has been alleged to contain a handkerchief dipped into the blood of the French king Louis XVI (1754-1793) after his beheading but recent analyses of living males from two Bourbon branches cast doubts on its authenticity. We sequenced the complete genome of the DNA contained in the gourd at low coverage (~2.5×) with coding sequences enriched at a higher ~7.3× coverage. We found that the ancestry of the gourd's genome does not seem compatible with Louis XVI's known ancestry. From a functional perspective, we did not find an excess of alleles contributing to height despite being described as the tallest person in Court. In addition, the eye colour prediction supported brown eyes, while Louis XVI had blue eyes. This is the first draft genome generated from a person who lived in a recent historical period; however, our results suggest that this sample may not correspond to the alleged king. PMID:24763138

  2. Calorimetric study of Te15(Se100- x Bi x )85 glassy alloys using differential thermal analysis

    NASA Astrophysics Data System (ADS)

    Kumar, Kameshwar; Thakur, Nagesh; Bhatt, S. S.; Sharma, Pankaj

    2010-10-01

    A calorimetric study of Te15(Se100- x Bi x )85 glassy alloys (x = 0, 1, 2, 3 and 4 at. %) is reported. Differential thermal analysis (DTA) was performed at heating rates of 10, 15, 20 and 25 K/min. The spectra were used to determine the glass transition temperature, Tg , the crystallisation temperature, Tc and the melting temperature, Tm . All these parameters shift to higher values with increasing heating rate, β. The glass transition temperature and the melting temperature increase, and the crystallisation temperature decreases, with increase in the Bi content, x. The activation energy of the glass transition, Eg , was evaluated using the Moynihan and Kissinger methods. The activation energy of crystallisation, Ec , was calculated using modified Kissinger and Matusita approaches. The thermal stability of these glasses has been studied and found to decrease with increase in Bi content. The results obtained are explained on the basis of a chemically ordered network model and an average coordination number.

  3. Calorimetric measurement of afterheat in target materials for the accelerator production of tritium

    SciTech Connect

    Perry, R.B.; Zucker, M.S.

    1994-06-01

    The estimate of afterheat in a spallation target of lead (Pb) or tungsten (W), by calorimetry, is the purpose of this experiment in support of the Accelerator Production of Tritium (APT). Such measurements are needed to confirm code calculations, these being the only practical way of gaining this type of information in a form suitable to aid the design of the APT machine. Knowledge of the magnitude and duration of afterheat resulting from decay of activation products produced by proton bombardment of the target is necessary to quantify APT safety assumptions, to design target cooling and safety systems, and to reduce technical risk. Direct calorimetric measurement of the afterheat for the appropriate incident proton energies is more reliable than the available alternative, which is indirect, based on data from gamma-ray spectroscopy measurements. The basic concept, a direct measurement of decay afterheat which bypasses the laborious classical way of determining this quantity, has been demonstrated to work. The gamma-ray energy given off by the decay products produced in the activation of lead or tungsten with high-energy protons apparently does represent a significant fraction of the total decay energy. A calorimeter designed for measurement of isotopes decaying by alpha emission must be modified to reduce energy lost with escaping gamma rays. Replacement of the aluminum liner with a tungsten liner in the SSC measurement chamber resulted in a 270% increase in measured heat, proving that the energy loss in the earlier (1992) measurements was significant. Gamma-ray measurements are needed to confirm the gamma-ray absorption calculations for the calorimeter to determine the correction for loss of heat due to transmission of high-energy gamma rays through the calorimeter walls. The experiments at BLIP have shown that calorimetry can be a useful tool in measuring the afterheat in APT target materials.

  4. 45 CFR 233.145 - Expiration of medical assistance programs under titles I, IV-A, X, XIV and XVI of the Social...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... titles I, IV-A, X, XIV and XVI of the Social Security Act. 233.145 Section 233.145 Public Welfare..., XIV and XVI of the Social Security Act. (a) Under the provisions of section 121(b) of Pub. L. 89-97... Social Security Act for aid or assistance in the form of medical or any other type of remedial care...

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

    USGS Publications Warehouse

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

    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.

  6. Comparing M31 and Milky Way satellites: The extended star formation histories of Andromeda II and Andromeda XVI

    SciTech Connect

    Weisz, Daniel R.; Skillman, Evan D.; McQuinn, Kristen B. W.; Hidalgo, Sebastian L.; Monelli, Matteo; Gallart, Carme; Aparicio, Antonio; McConnachie, Alan; Stetson, Peter B.; Bernard, Edouard J.; Boylan-Kolchin, Michael; Cassisi, Santi; Cole, Andrew A.; Ferguson, Henry C.; Irwin, Mike; Martin, Nicolas F.; Mayer, Lucio; Navarro, Julio F.

    2014-07-01

    We present the first comparison between the lifetime star formation histories (SFHs) of M31 and Milky Way (MW) satellites. Using the Advanced Camera for Surveys on board the Hubble Space Telescope, we obtained deep optical imaging of Andromeda II (And II; M{sub V} = –12.0; log(M {sub *}/M {sub ☉}) ∼ 6.7) and Andromeda XVI (And XVI; M{sub V} = –7.5; log(M {sub *}/M {sub ☉}) ∼ 4.9) yielding color-magnitude diagrams that extend at least 1 mag below the oldest main-sequence turnoff, and are similar in quality to those available for the MW companions. And II and And XVI show strikingly similar SFHs: both formed 50%-70% of their total stellar mass between 12.5 and 5 Gyr ago (z ∼ 5-0.5) and both were abruptly quenched ∼5 Gyr ago (z ∼ 0.5). The predominance of intermediate age populations in And XVI makes it qualitatively different from faint companions of the MW and clearly not a pre-reionization fossil. Neither And II nor And XVI appears to have a clear analog among MW companions, and the degree of similarity in the SFHs of And II and And XVI is not seen among comparably faint-luminous pairs of MW satellites. These findings provide hints that satellite galaxy evolution may vary substantially among hosts of similar stellar mass. Although comparably deep observations of more M31 satellites are needed to further explore this hypothesis, our results underline the need for caution when interpreting satellite galaxies of an individual system in a broader cosmological context.

  7. Genetic analysis of the presumptive blood from Louis XVI, King of France.

    PubMed

    Lalueza-Fox, Carles; Gigli, Elena; Bini, Carla; Calafell, Francesc; Luiselli, Donata; Pelotti, Susi; Pettener, Davide

    2011-11-01

    A text on a pyrographically decorated gourd dated to 1793 explains that it contains a handkerchief dipped with the blood of Louis XVI, king of France, after his execution. Biochemical analyses confirmed that the material contained within the gourd was blood. The mitochondrial DNA (mtDNA) hypervariable region 1 (HVR1) and 2 (HVR2), the Y-chromosome STR profile, some autosomal STR markers and a SNP in HERC2 gene associated to blue eyes, were retrieved, and some results independently replicated in two different laboratories. The uncommon mtDNA sequence retrieved can be attributed to a N1b haplotype, while the novel Y-chromosome haplotype belongs to haplogroup G2a. The HERC2 gene showed that the subject analyzed was a heterozygote, which is compatible with a blue-eyed person, as king Louis XVI was. To confirm the identity of the subject, an analysis of the dried heart of his son, Louis XVII, could be undertaken. PMID:20940110

  8. 76 FR 45309 - Social Security Ruling 11-1p; Titles II and XVI: Procedures for Handling Requests To File...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... ADMINISTRATION Social Security Ruling 11-1p; Titles II and XVI: Procedures for Handling Requests To File... ] procedures for handling your request to file a disability claim when you have a pending claim of the same... Office of the General Counsel, or other interpretations of the law and regulations. Although SSRs do...

  9. 78 FR 17744 - Social Security Ruling, SSR 13-2p; Titles II and XVI: Evaluating Cases Involving Drug Addiction...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION Social Security Ruling, SSR 13-2p; Titles II and XVI: Evaluating Cases Involving Drug Addiction... Federal Register on February 20, 2013. (78 FR 11939). On page 11940, in the first column, under...

  10. 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

  11. The calorimetric spectrum of the electron-capture decay of 163Ho. The spectral endpoint region

    NASA Astrophysics Data System (ADS)

    De Rújula, A.; Lusignoli, M.

    2016-05-01

    The electron-neutrino mass (or masses and mixing angles) may be directly measurable in weak electron-capture decays. The favoured experimental technique is "calorimetric". The optimal nuclide is 163Ho, and several experiments (ECHo, HOLMES and NuMECS) are currently studying its decay. The most relevant range of the calorimetric-energy spectrum extends for the last few hundred eV below its endpoint. It has not yet been well measured. We explore the theory, mainly in the cited range, of electron capture in 163Ho decay. A so far neglected process turns out to be most relevant: electron-capture accompanied by the shake-off of a second electron. Our two main conclusions are very encouraging: the counting rate close to the endpoint may be more than an order of magnitude larger than previously expected; the "pile-up" problem may be significantly reduced.

  12. GYROTRON POWER BALANCE BASED ON CALORIMETRIC MEASUREMENTS IN THE DIII-D ECH SYSTEM

    SciTech Connect

    GORELOV,I.A; LOHR,J.M; BAITY,JR.,F.W; CAHALAN,P; CALLIS,R.W; PONCE,D; CHIU,H.K

    2003-10-01

    OAK-B135 A powerful microwave system operating at the second harmonic of the electron cyclotron frequency on the DIII-D tokamak was upgraded up to six assemblies of 110 GHz gyrotrons in 2003. three Gycom gyrotrons nominally generate 750 kW for 2 s pulses, with the pulse length limit resulting from the peak temperature allowed on the boron nitride rf output window. Three Communications and Power Industries (CPI) gyrotrons with diamond windows have been recently installed and have been tested to 0.9-1.0 MW for 5 s pulses. Heat loading on internal parts of the gyrotrons, the matching optics unit and the dummy loads is measured calorimetrically. This paper discusses the calorimetry system and calorimetric measurements of gyrotron performance.

  13. Investigation of the accuracy of MV radiation isocentre calculations in the Elekta cone-beam CT software XVI

    NASA Astrophysics Data System (ADS)

    Riis, Hans L.; Moltke, Lars N.; Zimmermann, Sune J.; Ebert, Martin A.; Rowshanfarzad, Pejman

    2016-06-01

    Accurate determination of the megavoltage (MV) radiation isocentre of a linear accelerator (linac) is an important task in radiotherapy. The localization of the MV radiation isocentre is crucial for correct calibration of the in-room lasers and the cone-beam CT scanner used for patient positioning prior to treatment. Linac manufacturers offer tools for MV radiation isocentre localization. As a user, there is no access to the documentation for the underlying method and calculation algorithm used in the commercial software. The idea of this work was to evaluate the accuracy of the software tool for MV radiation isocentre calculation as delivered by Elekta using independent software. The image acquisition was based on the scheme designed by the manufacturer. Eight MV images were acquired in each series of a ball-bearing (BB) phantom attached to the treatment couch. The images were recorded at cardinal angles of the gantry using the electronic portal imaging device (EPID). Eight Elekta linacs with three different types of multileaf collimators (MLCs) were included in the test. The influence of MLC orientation, x-ray energy, and phantom modifications were examined. The acquired images were analysed using the Elekta x-ray volume imaging (XVI) software and in-house developed (IHD) MATLAB code. Results from the two different software were compared. A discrepancy in the longitudinal direction of the isocentre localization was found averaging 0.23 mm up to a maximum of 0.75 mm. The MLC orientation or the phantom asymmetry in the longitudinal direction do not appear to cause the discrepancy. The main cause of the differences could not be clearly identified. However, it is our opinion that the commercial software delivered by the linac manufacturer should be improved to reach better stability and precise results in the MV radiation isocentre calculations.

  14. Investigation of the accuracy of MV radiation isocentre calculations in the Elekta cone-beam CT software XVI.

    PubMed

    Riis, Hans L; Moltke, Lars N; Zimmermann, Sune J; Ebert, Martin A; Rowshanfarzad, Pejman

    2016-06-01

    Accurate determination of the megavoltage (MV) radiation isocentre of a linear accelerator (linac) is an important task in radiotherapy. The localization of the MV radiation isocentre is crucial for correct calibration of the in-room lasers and the cone-beam CT scanner used for patient positioning prior to treatment. Linac manufacturers offer tools for MV radiation isocentre localization. As a user, there is no access to the documentation for the underlying method and calculation algorithm used in the commercial software. The idea of this work was to evaluate the accuracy of the software tool for MV radiation isocentre calculation as delivered by Elekta using independent software. The image acquisition was based on the scheme designed by the manufacturer. Eight MV images were acquired in each series of a ball-bearing (BB) phantom attached to the treatment couch. The images were recorded at cardinal angles of the gantry using the electronic portal imaging device (EPID). Eight Elekta linacs with three different types of multileaf collimators (MLCs) were included in the test. The influence of MLC orientation, x-ray energy, and phantom modifications were examined. The acquired images were analysed using the Elekta x-ray volume imaging (XVI) software and in-house developed (IHD) MATLAB code. Results from the two different software were compared. A discrepancy in the longitudinal direction of the isocentre localization was found averaging 0.23 mm up to a maximum of 0.75 mm. The MLC orientation or the phantom asymmetry in the longitudinal direction do not appear to cause the discrepancy. The main cause of the differences could not be clearly identified. However, it is our opinion that the commercial software delivered by the linac manufacturer should be improved to reach better stability and precise results in the MV radiation isocentre calculations. PMID:27183466

  15. 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.

  16. 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

  17. Calorimetric evaluation of commercial Ni-MH cells and charges

    NASA Technical Reports Server (NTRS)

    Darcy, Eric C.; Hughes, Brent M.

    1995-01-01

    The test objectives are to evaluate the electrical and thermal performance of commercial Ni-MH cells and to evaluate the effectiveness of commercial charge control circuits. The ultimate design objectives are to determine which cell designs are most suitable for scale-up and to guide the design of future Shuttle and Station based battery chargers.

  18. Non-destructive testing of an original XVI century painting on wood by ESPI system

    NASA Astrophysics Data System (ADS)

    Arena, G.; Paturzo, M.; Fatigati, G.; Grilli, M.; Pezzati, L.; Ferraro, P.

    2015-03-01

    Electronic Speckle Pattern Interferometry (ESPI), a non-contact and non-destructive optical techniques, was employed for assessing the conservation state of a XVI Century painting on wood (72x88x1,9 cm). By a long term analysis, the whole structure alterations, induced by the room temperature and relative humidity variations, were evaluated. Measurement of the whole painting structural bends was achieved. Local flaws and hidden detachments of pictorial layers from the support, which cannot be recognized by traditional art-restorer methods, were also revealed. This work was prevalently aimed at achieving a simple approach, in the laboratory practice, to get an intuitively user-friendly method for art conservators, not accustomed to high-tech or math based methods. The results demonstrate that ESPI can largely improve the traditional art conservation survey techniques.

  19. Calorimetric studies of natural talc: Enthalpy of dehydroxylation

    NASA Astrophysics Data System (ADS)

    Ogorodova, L. P.; Kiseleva, I. A.

    2011-10-01

    The standard dehydroxylation enthalpy of natural talc Mg3[Si4O10](OH)2 (87.8 ± 9.0 kJ/mol at 298.15 K) and the enthalpy of formation of dehydrated talc from the elements (Δf H {el/o} (298.15 K) = -5527.0 ± 9.0 kJ/mol) were determined for the first time using Hess's law, based on the total values of the enthalpy increments in heating a sample from room temperature to 973 K and the enthalpies of dissolution at 973 K for dehydrated talc measured in this work and those previously determined for talc and corresponding oxides.

  20. PREFACE: XVI International Youth Scientific School 'Actual Problems of Magnetic Resonance and its Applications'

    NASA Astrophysics Data System (ADS)

    Salakhov, M. Kh; Tagirov, M. S.; Dooglav, A. V.

    2013-12-01

    In 1997, A S Borovik-Romanov, the Academician of RAS, and A V Aganov, the head of the Physics Department of Kazan State University, suggested that the 'School of Magnetic Resonance', well known in the Soviet Union, should recommence and be regularly held in Kazan. This school was created in 1968 by G V Scrotskii, the prominent scientist in the field of magnetic resonance and the editor of many famous books on magnetic resonance (authored by A Abragam, B. Bleaney, C. Slichter, and many others) translated and edited in the Soviet Union. In 1991 the last, the 12th School, was held under the supervision of G V Scrotskii. Since 1997, more than 600 young scientists, 'schoolboys', have taken part in the School meetings, made their oral reports and participated in heated discussions. Every year a competition among the young scientist takes place and the Program Committee members name the best reports, the authors of which are invited to prepare full-scale scientific papers. The XVI International Youth Scientific School 'Actual problems of the magnetic resonance and its application' in its themes is slightly different from previous ones. A new section has been opened this year: Coherent Optics and Optical Spectroscopy. Many young people have submitted interesting reports on optical research, many of the reports are devoted to the implementation of nanotechnology in optical studies. The XVI International Youth Scientific School has been supported by the Program of development of Kazan Federal University. It is a pleasure to thank the sponsors (BRUKER Ltd, Moscow, the Russian Academy of Science, the Dynasty foundation of Dmitrii Zimin, Russia, Russian Foundation for Basic Research) and all the participants and contributors for making the International School meeting possible and interesting. A V Dooglav, M Kh Salakhov and M S Tagirov The Editors

  1. 45 CFR 233.145 - Expiration of medical assistance programs under titles I, IV-A, X, XIV and XVI of the Social...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... titles I, IV-A, X, XIV and XVI of the Social Security Act. 233.145 Section 233.145 Public Welfare... FINANCIAL ASSISTANCE PROGRAMS § 233.145 Expiration of medical assistance programs under titles I, IV-A, X..., enacted July 30, 1965, no payment may be made to any State under title I, IV-A, X, XIV or XVI of...

  2. 45 CFR 233.145 - Expiration of medical assistance programs under titles I, IV-A, X, XIV and XVI of the Social...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... titles I, IV-A, X, XIV and XVI of the Social Security Act. 233.145 Section 233.145 Public Welfare... FINANCIAL ASSISTANCE PROGRAMS § 233.145 Expiration of medical assistance programs under titles I, IV-A, X..., enacted July 30, 1965, no payment may be made to any State under title I, IV-A, X, XIV or XVI of...

  3. 45 CFR 233.145 - Expiration of medical assistance programs under titles I, IV-A, X, XIV and XVI of the Social...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... titles I, IV-A, X, XIV and XVI of the Social Security Act. 233.145 Section 233.145 Public Welfare... FINANCIAL ASSISTANCE PROGRAMS § 233.145 Expiration of medical assistance programs under titles I, IV-A, X..., enacted July 30, 1965, no payment may be made to any State under title I, IV-A, X, XIV or XVI of...

  4. 45 CFR 233.145 - Expiration of medical assistance programs under titles I, IV-A, X, XIV and XVI of the Social...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... titles I, IV-A, X, XIV and XVI of the Social Security Act. 233.145 Section 233.145 Public Welfare... FINANCIAL ASSISTANCE PROGRAMS § 233.145 Expiration of medical assistance programs under titles I, IV-A, X..., enacted July 30, 1965, no payment may be made to any State under title I, IV-A, X, XIV or XVI of...

  5. 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.

  6. 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.

  7. A calorimetric investigation of doxorubicin-polymer bead interactions.

    PubMed

    Waters, Laura J; Swaine, Tanya S; Lewis, Andrew L

    2015-09-30

    Isothermal titration calorimetry (ITC) was utilised to investigate suitability of the technique to determine the stoichiometry and thermodynamics of the interactions that occur between a commonly used chemotherapeutic drug, namely doxorubicin, and a polymer bead-based drug delivery embolisation system (DC Bead™). Six temperatures were selected for drug-polymer titrations (293-313 K) and in all cases an initially exothermic signal reverted to an endothermic response upon the saturation of the beads with drug. From these experiments, and subsequent calculations, the molar ratio of drug to SO3(-) (polymer) was found to be 0.4:1 at all temperatures studied. Enthalpic data was calculated from the raw ITC data with an average enthalpy of drug-polymer binding of - 14.8 kJ mol(-1) at 293 K through to - 19.4 kJ mol(-1) at 313 K implying the process is enthalpically-driven yet only affected by an increase in experimental temperature to a limited extent whereby an increase in experimental temperature results in a small increase in the negativity in change in enthalpy recorded. The application of ITC in this study (with its unique ability to monitor real-time interactions and facilitate stoichiometric calculations) resolves the lack of knowledge regarding the thermodynamics of this specific drug-polymer interaction. This study confirms that ITC is not only useful for this specific system, but also highlights the potential use of ITC for more general studies in this area. PMID:26209073

  8. Nanowell-patterned TiO{sub 2} microcantilevers for calorimetric chemical sensing

    SciTech Connect

    Lee, Dongkyu Chae, Inseok; Thundat, Thomas; Kim, Seonghwan; Jeon, Sangmin

    2014-04-07

    A sensitive calorimetric sensor using a TiO{sub 2} microcantilever with nanowells patterned on one of its sides is described. This single material cantilever is sensitive to temperature change without relying on the metal deposition-based bimetallic effect. The thermomechanical sensitivity originates from the structure dependent variations in both the elastic modulus and thermal expansion coefficient due to the presence of ordered nanowells. These cantilever beams offer an alternate and efficient chemical sensing route for vapor phase analytes using photothermal spectroscopy. Selective and sensitive detection of organophosphorus compounds, as well as their photocatalytic decomposition under ultraviolet light exposure are demonstrated.

  9. 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.

  10. Chemical trends of the luminescence in wide band gap II 1-xMn xVI semimagnetic semiconductors

    NASA Astrophysics Data System (ADS)

    Benecke, C.; Busse, W.; Gumlich, H.-E.

    1990-04-01

    Time resolved emission and excitation spectroscopy is used to investigate the Mn correlated luminescence in wide band gap II-VI compounds, i.e. Zn 1-xMn xS, Cd 1-xMn xSe, Zn 1-xMn xTe and Cd 1-xMn xTe. Additional Information has been obtained with CdxZnyMnzTe( x+ y+ z=1) in checking the luminescence by variation of the ratio of the cations Cd and Zn. Generally speaking, at least two distinct emissions bands can be observed for each II 1- xMn xVI compound. One emissions band is attributed to the internal transition 4T 1(G)→ 6A 1(S) of the 3d 5 electron of the Mn 2+ on regular metal sites with energies of about ≈2 eV. The other emission band is found to occur in the near infrared range of about ≈1.3 eV. This emission band is tentatively interpreted as a transition of Mn 2+ ions on interstitial sites or in small Mn chalcogenide clusters, both interpretations assuming cubic symmetry. This model is supported by the existence of low energy excitation bands and by the great similarity of the shape of the two emission bands which lead to comparable Huang-Rhys factors and effective phonon energies. Also the established trend in the experimental data of the II-VI compounds under consideration confirm this interpretation. For both the IR and the yellow Mn 2+ center, the Racah parameters B and C and the crystal field parameter Dq are determined on the basis of experimental data. As a result, the energy of both the emission and the excitation bands is predominantly determined by the sorrounding anions. These bands shift to higher energies when the anions are changed in the fixed order: Te→Se→S. Regularly, there is also a spectral shift when Zn is replaced by Cd, which is smaller than the shift due to the variation of onions.

  11. Genetic comparison of the head of Henri IV and the presumptive blood from Louis XVI (both Kings of France).

    PubMed

    Charlier, Philippe; Olalde, Iñigo; Solé, Neus; Ramírez, Oscar; Babelon, Jean-Pierre; Galland, Bruno; Calafell, Francesc; Lalueza-Fox, Carles

    2013-03-10

    A mummified head was identified in 2010 as belonging to Henri IV, King of France. A putative blood sample from the King Louis XVI preserved into a pyrographically decorated gourd was analyzed in 2011. Both kings are in a direct male-line descent, separated by seven generations. We have retrieved the hypervariable region 1 of the mitochondrial DNA as well as a partial Y-chromosome profile from Henri IV. Five STR loci match the alleles found in Louis XVI, while another locus shows an allele that is just one mutation step apart. Taking into consideration that the partial Y-chromosome profile is extremely rare in modern human databases, we concluded that both males could be paternally related. The likelihood ratio of the two samples belonging to males separated by seven generations (as opposed to unrelated males) was estimated as 246.3, with a 95% confidence interval between 44.2 and 9729. Historically speaking, this forensic DNA data would confirm the identity of the previous Louis XVI sample, and give another positive argument for the authenticity of the head of Henri IV. PMID:23283403

  12. 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. PMID:20687748

  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 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.

  15. 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

  16. Soft X-Ray Emission Lines of Argon, ArIX -- ArXVI

    NASA Astrophysics Data System (ADS)

    Lepson, J. K.; Beiersdorfer, P.; Chen, H.; Behar, E.; Kahn, S. M.

    2002-04-01

    The soft x-ray region of 20 - 50 Å is nearly unknown territory to astrophysicists. This spectral band remains virtually unstudied, even in solar observations, and laboratory measurements are similarly lacking. Spectra obtained from Chandra and XMM-Newton X-Ray Observatories show a wealth of lines in this region, albeit weak in most cases. Most of these lines remain unidentified as observations have now outpaced the available databases. In support of these missions we have undertaken laboratory measurements of astrophysically relevant ions in the extreme ultraviolet and soft x-ray regions using the Livermore electron beam ion trap EBIT-II. We present here results of argon, covering ArIX - ArXVI between 20 - 50 Åand compare our spectra with calculations from the Hebrew University - Lawrence Livermore Atomic Code HULLAC. EBIT-II data agree broadly with HULLAC calculations, with accuracy of ± 0.3 Å for most major lines. Given the density of lines in Chandra and XMM-Newton spectra, this accuracy is often insufficient for line identification in the absence of careful laboratory mesaurements. Work performed under auspices of DOE by UC LLNL and funded by NASA SARA.

  17. 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.

  18. Molecular mobility and relaxation process of isolated lignin studied by multifrequency calorimetric experiments.

    PubMed

    Guigo, Nathanael; Mija, Alice; Vincent, Luc; Sbirrazzuoli, Nicolas

    2009-02-28

    The glass transition of lignin has been studied by multifrequency calorimetric measurements in order to highlight the morphological changes and the dynamic aspects associated to this relaxation process. Influences of water sorption and thermal annealing on molecular mobility have been considered. Additional investigations by thermogravimetry, infra-red spectroscopy and rheometry have been performed to corroborate the claims. The relaxation process of annealed lignin shows a different behaviour as the consequence of micro-structural modifications of lignin. These are explained by redistribution of secondary bonds as well as formation of new interunit linkages. Concerning the dynamic aspects, apparent activation energy, E, and sizes of cooperatively rearranging region, V(crr), have been evaluated respectively from the frequency dependence and heat capacity measurements of the glass transition. Compared to dried lignin, both E and V(crr) significantly decrease in a water-sorbed matrix indicating that the three-dimensional structure presents a higher mobility and is less confined. PMID:19209367

  19. 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.

  20. AC loss measurement of superconducting dipole magnets by the calorimetric method

    SciTech Connect

    Morita, Y.; Hara, K.; Higashi, N.; Kabe, A.

    1996-12-31

    AC losses of superconducting dipole magnets were measured by the calorimetric method. The magnets were model dipole magnets designed for the SSC. These were fabricated at KEK with 50-mm aperture and 1.3-m overall length. The magnet was set in a helium cryostat and cooled down to 1.8 K with 130 L of pressurized superfluid helium. Heat dissipated by the magnet during ramp cycles was measured by temperature rise of the superfluid helium. Heat leakage into the helium cryostat was 1.6 W and was subtracted from the measured heat to obtain AC loss of the magnet. An electrical measurement was carried out for calibration. Results of the two methods agreed within the experimental accuracy. The authors present the helium cryostat and measurement system in detail, and discuss the results of AC loss measurement.

  1. 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.

  2. 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. PMID:27357677

  3. 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.

  4. The Bayer Facts of Science Education XVI: "US STEM Workforce Shortage--Myth or Reality? Fortune 1000 Talent Recruiters on the Debate"

    ERIC Educational Resources Information Center

    Journal of Science Education and Technology, 2014

    2014-01-01

    A major debate is currently underway in the USA about whether there is, in fact, a science, technology, engineering and mathematics (STEM) workforce shortage in the country or not. This is the subject of the "Bayer Facts of Science Education XVI: US STEM Workforce Shortage--Myth or Reality? Fortune 1000 Talent Recruiters on the Debate."…

  5. Calorimetric output power measurements on a CW 20 kW 7.16 GHz microwave transmitter

    NASA Technical Reports Server (NTRS)

    Perez, Raul M.; Conroy, Bruce L.

    1991-01-01

    A calorimetric measurement technique developed for NASA's Deep Space Network (DSN) transmitters that does not require data on the coolant's thermal parameters is described. Calibration of the measurement system is achieved by measuring the DC input power to the klystron and relating coolant temperature increases to this known power dissipation. Agreement between calorimetric and electrical measurements of total system power was good, the difference being less than 2 percent. The operation of the system was not greatly affected by the composition of the coolant, which was varied from pure water to 40 percent ethylene glycol by mass. Good accuracy was also shown at output power levels, which varied over a 3.6:1 range.

  6. 20 CFR 404.1597a - Continued benefits pending appeal of a medical cessation determination.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... medical cessation determination. 404.1597a Section 404.1597a Employees' Benefits SOCIAL SECURITY... Continuing Or Stopping Disability § 404.1597a Continued benefits pending appeal of a medical cessation...). If you appeal a medical cessation under both title II and title XVI (a concurrent case), the title...

  7. 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

  8. 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.

  9. Algorithms for Identification of Nearly-Coincident Events in Calorimetric Sensors

    NASA Astrophysics Data System (ADS)

    Alpert, B.; Ferri, E.; Bennett, D.; Faverzani, M.; Fowler, J.; Giachero, A.; Hays-Wehle, J.; Maino, M.; Nucciotti, A.; Puiu, A.; Swetz, D.; Ullom, J.

    2015-12-01

    For experiments with high arrival rates, reliable identification of nearly-coincident events can be crucial. For calorimetric measurements to directly measure the neutrino mass such as HOLMES, unidentified pulse pile-ups are expected to be a leading source of experimental error. Although Wiener filtering can be used to recognize pile-up, it suffers from errors due to pulse shape variation from detector nonlinearity, readout dependence on subsample arrival times, and stability issues from the ill-posed deconvolution problem of recovering Dirac delta-functions from smooth data. Due to these factors, we have developed a processing method that exploits singular value decomposition to (1) separate single-pulse records from piled-up records in training data and (2) construct a model of single-pulse records that accounts for varying pulse shape with amplitude, arrival time, and baseline level, suitable for detecting nearly-coincident events. We show that the resulting processing advances can reduce the required performance specifications of the detectors and readout system or, equivalently, enable larger sensor arrays and better constraints on the neutrino mass.

  10. 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).

  11. 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).

  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 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.

  14. 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.

  15. Thermodynamic model for calorimetric and phase coexistence properties of coal derived fluids

    SciTech Connect

    Kabadi, V.N.

    1990-01-01

    A model for phase equilibria of coal derived liquids is to be extended to include calorimetric properties as well. To accomplish this satisfactorily, the proposed work includes three tasks: (1) Refinement of the characterization procedure to include distribution of sulfur, oxygen, and nitrogen heteroatoms in coal liquids; (2) Measurement of high temperature (up to 400{degrees}C) and high pressure (up to 1000 psi) VLE data for binary systems of selected model compounds; and (3) Development of the thermodynamic model. The final product will include a computer program which with measurable properties of coal liquids as input, will give results for phase coexistence properties and excess enthalpies in the liquid phase. Efforts are continuing to apply the new thermodynamic model for VLE and enthalpy predictions for coal liquids by the methods of continuous thermodynamics. Recently, Thompson, Brobst and Hankinson have developed an equation of state that represents compressibilities of liquids very well. The authors have undertaken the task of combining this equation of state with their thermodynamic model to provide a comprehensive model for high pressure liquid mixtures. Calibration and preliminary set-up procedure for the VLE apparatus with the new liquid level sensor have been completed. The apparatus is currently being tested with the binary system quinoline-tetralin. Chromatographic characterization work was delayed because of complexities of the calibration procedure and tedious calculations necessary for number average and weight average molecular weights. Results on the chromatographic studies are being deferred until computer software is received.

  16. 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).

  17. 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.

  18. 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.

  19. Effect of sulfoxides on the thermal denaturation of hen lysozyme: A calorimetric and Raman study

    NASA Astrophysics Data System (ADS)

    Torreggiani, A.; Di Foggia, M.; Manco, I.; De Maio, A.; Markarian, S. A.; Bonora, S.

    2008-11-01

    A multidisciplinary study of the thermal denaturation of lysozyme in the presence of three sulfoxides with different length in hydrocarbon chain (DMSO, DESO, and DPSO) was carried out by means of DSC, Raman spectroscopy, and SDS-PAGE techniques. In particular, the Td and Δ H values obtained from the calorimetric measurements showed that lysozyme is partially unfolded by sulfoxides but most of the conformation holds native state. The sulfoxide denaturing ability increases in the order DPSO > DESO > DMSO. Moreover, only DMSO and DESO have a real effect in preventing the heat-induced inactivation of the protein and their maximum heat-protective ability is reached when the DMSO and DESO amount is ⩾25% w/w. The sulfoxide ability to act as effective protective agents against the heat-induced inactivation was confirmed by the protein analysis. The enzymatic activity, as well as the SDS-PAGE analysis, suggested that DESO, having a low hydrophobic character and a great ability to stabilise the three-dimensional water structure, is the most heat-protective sulfoxide. An accurate evaluation of the heat-induced conformational changes of the lysozyme structure before and after sulfoxide addition was obtained by the analysis of the Raman spectra. The addition of DMSO or DESO in low concentration resulted to sensitively decrease the heat-induced structural modifications of the protein.

  20. Characterization of commercial Li-ion batteries using electrochemical-calorimetric measurements

    NASA Astrophysics Data System (ADS)

    Al Hallaj, S.; Prakash, J.; Selman, J. R.

    Commercial Li-ion cells of Type 18650 dimensions and prismatic designs from different manufacturers have been tested to evaluate their performance and to study their thermal behavior using electrochemical-calorimetric methods. All cells tested in this work showed good performance and cyclability under normal operating conditions. The measured heat effect for the cells were exothermic during discharge and partially endothermic during charge. Cell impedance was measured for selected cells and showed some dependence on the state of charge or depth of discharge, with significant increase at the end of discharge due to concentration polarization. The entropy coefficient (d Eeq/d T) for the A&T (18650) and Panasonic (CGR 18650) cells were measured using potentiometric methods at different depths of discharge (DOD). The measured values for both cells showed some dependence on the DOD with some perturbation near 4.0 V, where the measured d Eeq/d T for Panasonic cell had an unexpected positive value. This was found to be consistent with the measured endothermic heat effect during discharge for the Panasonic cell near Eeq=4.0 V. This may be related to a phase change in the LiCoO 2 cathode material, as reported in the literature, and to structural transformation in the graphite used as anode material, in the Panasonic cell.

  1. Algorithms for Identification of Nearly-Coincident Events in Calorimetric Sensors

    NASA Astrophysics Data System (ADS)

    Alpert, B.; Ferri, E.; Bennett, D.; Faverzani, M.; Fowler, J.; Giachero, A.; Hays-Wehle, J.; Maino, M.; Nucciotti, A.; Puiu, A.; Swetz, D.; Ullom, J.

    2016-07-01

    For experiments with high arrival rates, reliable identification of nearly-coincident events can be crucial. For calorimetric measurements to directly measure the neutrino mass such as HOLMES, unidentified pulse pile-ups are expected to be a leading source of experimental error. Although Wiener filtering can be used to recognize pile-up, it suffers from errors due to pulse shape variation from detector nonlinearity, readout dependence on subsample arrival times, and stability issues from the ill-posed deconvolution problem of recovering Dirac delta-functions from smooth data. Due to these factors, we have developed a processing method that exploits singular value decomposition to (1) separate single-pulse records from piled-up records in training data and (2) construct a model of single-pulse records that accounts for varying pulse shape with amplitude, arrival time, and baseline level, suitable for detecting nearly-coincident events. We show that the resulting processing advances can reduce the required performance specifications of the detectors and readout system or, equivalently, enable larger sensor arrays and better constraints on the neutrino mass.

  2. 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

  3. 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.

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

    PubMed

    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

  5. Calorimetric Study of Magnetic Field-Induced Phase Transitions in - Fulvalenium) -

    NASA Astrophysics Data System (ADS)

    Fortune, Nathanael Alexander

    The particular class of organic conductors known as the Bechgaard salts exhibit a variety of highly anisotropic magnetic, thermal, and electrical phenomena. At low temperatures (below 10 kelvin), the application of a strong magnetic field establishes an effectively lower-dimensional anisotropic Fermi surface, as manifested in a variety of quasi one dimensional and quasi two dimensional thermodynamic and transport properties. Most dramatically, an increasing magnetic field--after suppression of superconductivity, induces a second order phase transition from a metallic to a spin density wave semimetal, followed by a series of first order phase transitions between density wave semimetallic states. This thesis concerns the thermodynamic nature of the low temperature magnetic field induced phase transitions in the Bechgaard charge-transfer salt (TMTSF)2-Cl(O)4. Presented here are the first measurements of the specific heat in magnetic fields up to 30 tesla, as well as the design and construction of a small sample calorimeter capable of operating at dilution refrigerator temperatures in the challenging environment of the high field resistive Bitter magnets. From transport measurements, the existence of a magnetic field induced reentrance into the metallic state has previously been inferred. In this thesis, the unambiguous bulk thermodynamic character of the reentrance is calorimetrically demonstrated. The behavior of the electronic specific heat at the reentrant transition is shown to be consistent with magnetic field enhanced localization. Additionally, quantum oscillations in the high field semimetallic state and the presence of additional structure above the reentrant field are observed. Although these oscillations have also been observed in magnetoresistance and magnetization, the magnitude of the oscillations in the specific heat calls into question all known models for the physical origin of these oscillations.

  6. 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.

  7. 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

  8. 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

  9. 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.

  10. Analbite - Sanidine Thermodynamic Mixing Properties: Highly Precise HF Solution Calorimetric Data Across A Twenty-Member Crystalline Solution Series

    NASA Astrophysics Data System (ADS)

    Hovis, G. L.

    2013-12-01

    Enthalpies of K-Na mixing for the analbite - sanidine feldspar series were investigated by Hovis (1988, J. Petrology) in the early 80's. That work was based on data at a limited number of compositions, owing to the large sample sizes required for HF solution calorimetric measurements at the time. Thermodynamic mixing properties for mineral series, especially those exhibiting compositionally asymmetric mixing quantities, are best defined when samples at a large number of compositions are utilized. Enabled by the small sample sizes now possible for HF solution calorimetric dissolutions (Hovis et al., 1998, Amer. Mineral.), we revisit feldspar thermodynamic properties, having synthesized an analbite - sanidine series consisting of samples at 20 compositions. Solution calorimetric experiments on these samples at 50 °C in 20.1 wt% HF under isoperibolic conditions have resulted in highly precise calorimetric data (standard deviation per sample averaging 0.06 % of the heat of solution). Although enthalpies of K-Na mixing based on the new data display some degree of compositional asymmetry, with a maximum value of 4.8 kJ/mol at a mole fraction potassium of 0.47, the distribution of enthalpy-of-mixing values remains nearly symmetric with respect to K content. This contrasts significantly with data for Al-Si ordered low albite - microcline crystalline solutions, reinvestigated via synthesis of a 21-member series, which show significantly higher mixing magnitudes and considerably greater asymmetry with respect to composition. The maximization of enthalpies of K-Na mixing at sodic compositions correlates well with the sodic critical compositions for both solvi. The lower mixing magnitudes for analbite - sanidine are consistent with the comparatively lower critical temperature of the analbite - sanidine solvus (e.g., Smith & Parsons, 1974, Mineral. Mag.) relative to that for low albite - microcline (Bachinski & Müller, 1971, J. Petrology). Entropies of K-Na mixing for

  11. Analbite - Sanidine Thermodynamic Mixing Properties: Highly Precise HF Solution Calorimetric Data Across A Twenty-Member Crystalline Solution Series

    NASA Astrophysics Data System (ADS)

    Hovis, G. L.

    2012-12-01

    Enthalpies of K-Na mixing for the analbite - sanidine feldspar series were investigated by Hovis (1988, J. Petrology) in the early 80's. That work was based on data at a limited number of compositions, owing to the large sample sizes required for HF solution calorimetric measurements at the time. Thermodynamic mixing properties for mineral series, especially those exhibiting compositionally asymmetric mixing quantities, are best defined when samples at a large number of compositions are utilized. Enabled by the small sample sizes now possible for HF solution calorimetric dissolutions (Hovis et al., 1998, Amer. Mineral.), we revisit feldspar thermodynamic properties, having synthesized an analbite - sanidine series consisting of samples at 20 compositions. Solution calorimetric experiments on these samples at 50 °C in 20.1 wt% HF under isoperibolic conditions have resulted in highly precise calorimetric data (standard deviation per sample averaging 0.06 % of the heat of solution). Although enthalpies of K-Na mixing based on the new data display some degree of compositional asymmetry, with a maximum value of 4.8 kJ/mol at a mole fraction potassium of 0.47, the distribution of enthalpy-of-mixing values remains nearly symmetric with respect to K content. This contrasts significantly with data for Al-Si ordered low albite - microcline crystalline solutions, reinvestigated via synthesis of a 21-member series, which show significantly higher mixing magnitudes and considerably greater asymmetry with respect to composition. The maximization of enthalpies of K-Na mixing at sodic compositions correlates well with the sodic critical compositions for both solvi. The lower mixing magnitudes for analbite - sanidine are consistent with the comparatively lower critical temperature of the analbite - sanidine solvus (e.g., Smith & Parsons, 1974, Mineral. Mag.) relative to that for low albite - microcline (Bachinski & Müller, 1971, J. Petrology). Entropies of K-Na mixing for

  12. 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.

  13. Collagen XVI Induces Expression of MMP9 via Modulation of AP-1 Transcription Factors and Facilitates Invasion of Oral Squamous Cell Carcinoma

    PubMed Central

    Bedal, Konstanze B.; Grässel, Susanne; Oefner, Peter J.; Reinders, Joerg; Reichert, Torsten E.; Bauer, Richard

    2014-01-01

    Collagen XVI belongs to the family of fibril-associated collagens with interrupted triple helices (FACIT). It is overexpressed during the progression of oral squamous cell carcinoma (OSCC). The present data show a strong collagen XVI-dependent induction of MMP9 and an increase in OSCC cell invasion. We found activated integrin-linked kinase (ILK) in a complex with kindlin-1 and activation of protein kinase B (PKB/Akt) to be responsible for MMP9 induction. Inhibition of the formation of focal adhesions reduced MMP9 expression. Moreover, collagen XVI overexpressing OSCC cell clones (COLXVI cell clones) transfected with vectors containing different MMP9 promoter fragments adjacent to a luciferase reporter revealed an increase in luciferase signal dependent on AP-1 binding sites. Deletion of the AP-1 binding site 98 bp upstream of the reported transcription start site and inhibition of AP-1 with Tanshinone IIA resulted in decreased MMP9 expression. The AP-1 subunit JunB showed differential expression between COLXVI cell clones and mock control cells. Additionally, mass spectrometric analysis of immunoprecipitates revealed that c-Fos interacted strongly with dyskerin in COLXVI cell clones compared to mock controls. PMID:24466237

  14. HIGH-ACCURACY MR-MP PERTURBATION THEORY ENERGY AND RADIATIVE RATES CALCULATIONS FOR CORE-EXCITED TRANSITIONS IN Fe XVI

    SciTech Connect

    Diaz, F.; Vilkas, M. J.; Ishikawa, Y.; Beiersdorfer, P.

    2013-07-01

    Accurate theoretical energy level, lifetime, and transition probability calculations of core-excited Fe XVI were performed employing the relativistic Multireference Moller-Plesset perturbation theory. In these computations the term energies of the highly excited n {<=} 5 states arising from the configuration 1s {sup 2}2s{sup k} 2p{sup m} 3l {sup p} nl' {sup q}, where k + m + p + q = 9, l {<=} 3 and p + q {<=} 2 are considered, including those of the autoionizing levels with a hole-state in the L-shell. All even and odd parity states of sodium-like iron ion were included for a total of 1784 levels. Comparison of the calculated L-shell transition wavelengths with those from laboratory measurements shows excellent agreement. Therefore, our calculation may be used to predict the wavelengths of as of yet unobserved Fe XVI, such as the second strongest 2p-3d Fe XVI line, which has not been directly observed in the laboratory and which blends with one of the prominent Fe XVII lines.

  15. Investigation of a zirconia co-fired ceramic calorimetric microsensor for high-temperature flow measurements

    NASA Astrophysics Data System (ADS)

    Lekholm, Ville; Persson, Anders; Klintberg, Lena; Thornell, Greger

    2015-06-01

    This paper describes the design, fabrication and characterization of a flow sensor for high-temperature, or otherwise aggressive, environments, like, e.g. the propulsion system of a small spacecraft. The sensor was fabricated using 8 mol% yttria stabilized zirconia (YSZ8) high-temperature co-fired ceramic (HTCC) tape and screen printed platinum paste. A calorimetric flow sensor design was used, with five 80 µm wide conductors, separated by 160 µm, in a 0.4 mm wide, 0.1 mm deep and 12.5 mm long flow channel. The central conductor was used as a heater for the sensor, and the two adjacent conductors were used to resistively measure the heat transferred from the heater by forced convection. The two outermost conductors were used to study the influence of an auxiliary heat source on the sensor. The resistances of the sensor conductors were measured using four-point connections, as the gas flow rate was slowly increased from 0 to 40 sccm, with different power supplied through the central heater, as well as with an upstream or downstream heater powered. In this study, the thermal and electrical integrability of microcomponents on the YSZ8 substrate was of particular interest and, hence, the influence of thermal and ionic conduction in the substrate was studied in detail. The effect of the ion conductivity of YSZ8 was studied by measuring the resistance of a platinum conductor and the resistance between two adjacent conductors on YSZ8, in a furnace at temperatures from 20 to 930 °C and by measuring the resistance with increasing current through a conductor. With this design, the influence of ion conductivity through the substrate became apparent above 700 °C. The sensitivity of the sensor was up to 1 mΩ sccm-1 in a range of 0-10 sccm. The results show that the signal from the sensor is influenced by the integrated auxiliary heating conductors and that these auxiliary heaters provide a way to balance disturbing heat sources, e.g. thrusters or other electronics, in

  16. 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.

  17. Urea-induced dissociation and unfolding of dodecameric glutamine synthetase from Escherichia coli: calorimetric and spectral studies.

    PubMed Central

    Zolkiewski, M.; Nosworthy, N. J.; Ginsburg, A.

    1995-01-01

    Urea-induced dissociation and unfolding of manganese.glutamine synthetase (Mn.GS) have been studied at 37 degrees C (pH 7) by spectroscopic and calorimetric methods. In 0 to approximately 2 M urea, Mn.GS retains its dodecameric structure and full catalytic activity. Mn.GS is dissociated into subunits in 6 M urea, as evidenced by a 12-fold decrease in 90 degrees light scattering and a monomer molecular weight of 51,800 in sedimentation equilibrium studies. The light scattering decrease in 4 M urea parallels the time course of Trp exposure but occurs more rapidly than changes in secondary structure and Tyr exposure. Early and late kinetic steps appear to involve predominantly disruption of intra-ring and inter-ring subunit contacts, respectively, in the layered hexagonal structure of Mn.GS. The enthalpies for transferring Mn.GS into urea solutions have been measured by titration calorimetry. After correcting for the enthalpy of binding urea to the protein, the enthalpy of dissociation and unfolding of Mn.GS is 14 +/- 4 cal/g. A net proton uptake of approximately 50 H+/dodecamer accompanies unfolding reactions. The calorimetric data are consistent with urea binding to multiple, independent sites in Mn.GS and the number of binding sites increasing approximately 9-fold during the protein unfolding. PMID:8520480

  18. 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.

  19. X-ray fluorescence analysis of yellow pigments in altarpieces by Valencian artists of the XV and XVI centuries

    NASA Astrophysics Data System (ADS)

    Ferrero, J. L.; Roldán, C.; Ardid, M.; Navarro, E.

    1999-02-01

    XRF analysis has allowed a quick and precise detection and identification of the inorganic elements that compose the yellow pigments in altarpieces of the XV and XVI centuries painted by the Valencian artists Miguel Alcañiz, Vicente Macip, Juan de Juanes, Hernando Yáñez de la Almedina and Hernando Llanos. The analyses have been carried out with an XRF portable system that consists of a tube of X-rays and detectors of Si(Li) and cadmium zinc telluride. This system has enabled a non-aggressive and non-destructive analysis of many pieces at the Museo de Bellas Artes of Valencia (Spain). Among the yellow pigments we have identified a pigment composed by lead and tin oxides named lead-tin yellow (Pb 2SnO 4), frequently used in European paintings from the XIV century until the first half of the XVIII century. This fact demonstrates the influence of elements and pictorial techniques from Europe to the region of Valencia.

  20. Crop changes from the XVI century to the present in a hill/mountain area of eastern Liguria (Italy)

    PubMed Central

    Gentili, Rodolfo; Gentili, Elio; Sgorbati, Sergio

    2009-01-01

    Background Chronological information on the composition and structure of agrocenoses and detailed features of land cover referring to specific areas are uncommon in ethnobotanical studies, especially for periods before the XIX century. The aim of this study was to analyse the type of crop or the characteristics of soil cover from the XVI century to the present. Methods This diachronic analysis was accomplished through archival research on the inventories of the Parish of St. Mary and those of the Municipality of Pignone and from recent surveys conducted in an area of eastern Liguria (Italy). Results Archival data revealed that in study area the primary means of subsistence during the last five centuries, until the first half of the XX century, was chestnuts. In the XVIII and XIX centuries, crop diversification strongly increased in comparison with previous and subsequent periods. In more recent times, the abandonment of agricultural practices has favoured the re-colonisation of mixed woodland or cluster-pine woodland. Conclusion Ancient documents in the ecclesiastic or municipal inventories can be a very useful tool for enhancing the knowledge of agricultural practice, as well as of subsistence methods favoured by local populations during a particular time and for reconstructing land use change over time. PMID:19361339

  1. 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

  2. Thermal stability of extracellular hemoglobin of Glossoscolex paulistus: determination of activation parameters by optical spectroscopic and differential scanning calorimetric studies.

    PubMed

    Santiago, Patrícia S; Carvalho, José Wilson P; Domingues, Marco M; Santos, Nuno C; Tabak, Marcel

    2010-11-01

    Glossoscolex paulistus hemoglobin (HbGp) was studied by dynamic light scattering (DLS), optical absorption spectroscopy (UV-VIS) and differential scanning calorimetry (DSC). At pH 7.0, cyanomet-HbGp is very stable, no oligomeric dissociation is observed, while denaturation occurs at 56°C, 4°C higher as compared to oxy-HbGp. The oligomeric dissociation of HbGp occurs simultaneously with some protein aggregation. Kinetic studies for oxy-HbGp using UV-VIS and DLS allowed to obtain activation energy (E(a)) values of 278-262 kJ/mol (DLS) and 333 kJ/mol (UV-VIS). Complimentary DSC studies indicate that the denaturation is irreversible, giving endotherms strongly dependent upon the heating scan rates, suggesting a kinetically controlled process. Dependence on protein concentration suggests that the two components in the endotherms are due to oligomeric dissociation effect upon denaturation. Activation energies are in the range 200-560 kJ/mol. The mid-point transition temperatures were in the range 50-65 °C. Cyanomet-HbGp shows higher mid-point temperatures as well as activation energies, consistent with its higher stability. DSC data are reported for the first time for an extracellular hemoglobin. PMID:20875698

  3. Gibbs free energies of formation of RuO 2, IrO 2, and OsO 2: A high-temperature electrochemical and calorimetric study

    NASA Astrophysics Data System (ADS)

    O'Neill, Hugh St. C.; Nell, Johan

    1997-12-01

    The Gibbs free energies of formation of RuO 2, OsO 2 and IrO 2 have been determined by measuring the chemical potentials of oxygen (μO 2) defined by the reactions M + O 2 = MO 2, where M = Ru, Os. or Ir, using an electrochemical method with calcia-stabilized zirconia (CSZ) solid electrolytes. Measurements were attempted in the temperature ranges from ˜870 K to 1620, 1270, and 1415 K for the Ru, Os, and Ir equilibria, respectively, but inspection of the results reveals that equilibrium could not be established below ˜930 K for all three reactions. For Ru + RuO 2, the highest temperature data (above 1520 K) may be systematically affected by the onset of significant electronic conduction in the CSZ electrolyte, while the attempted measurements of the Os + OsO 2 equilibrium above 1190 K are obscured by the disproportionation of OsO 2 to gaseous Os oxides. The high temperature heat capacities at constant pressure ( Cp) of RuO 2 and IrO 2 were determined from 370 to 1070 K by differential scanning calorimetry. These data were combined with heat content measurements and low-temperature heat capacities from the literature, and fitted to an extended Maier-Kelley equation. The calorimetric data for RuO 2 and IrO 2, together with assessed data for Ru, Os, and Ir metals and estimated data for OsO 2, were used in a third law analysis of the electrochemical measurements. The values of μO 2 of the three equilibria were smoothed and filtered by the third-law analysis to yield the following equations which can be extrapolated to lower and higher temperatures as indicated: μO 2 ( Ru + RuO 2) = -324563 + 344.151 T-22.1155 T ln T (700 ⩽ T ⩽ 1800) μO 2 ( Os + OsO 2) = -300399 + 307.639 T-17.4819 T ln T (700 ⩽ T ⩽ 1500) μO 2 ( Ir + IrO 2) = -256518 + 295.854 T-15.2368 T ln T (700 ⩽ T ⩽ 1500) where μO 2 is in J mol -1, T is in K, the reference pressure for O 2 is 1 bar (10 5 Pa), and estimated accuracies are approximately 200 to 400 J mol -1. For Ru + RuO 2, the drift

  4. 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. PMID:12530828

  5. MEASUREMENT OF THE Fe VIII-Fe XVI 3-3 EMISSION IN THE EXTREME ULTRAVIOLET AND COMPARISON WITH CHIANTI

    SciTech Connect

    Beiersdorfer, P.; Lepson, J. K.

    2012-08-01

    Laboratory measurements of the n = 3 to n = 3 emission from M-shell iron ions are presented and compared to synthetic spectra from the CHIANTI spectral model. The measurements cover the range 170-290 Angstrom-Sign and are made at an electron density of about 10{sup 11} cm{sup -3}. Emission from Fe VIII through Fe XVI has been identified. Excellent agreement with CHIANTI predictions is found for most lines. Twenty weaker features are noted in the laboratory data that are either absent in CHIANTI or have recently been added and correspond to lines that have not been verified by experimental measurements. A few of these lines may have already been observed (but not yet identified) in the Sun. The features are attributed to emission from various charge states of iron, notably Fe IX and Fe XIII, and two features have been identified as transitions in Fe VIII, i.e., the 3p{sup 6}3d {sup 2}D{sub 5/2}-3p {sup 5}3d{sup 2} {sup 2}P{sub 3/2} and the 3p {sup 6}3d {sup 2}D{sub 3/2}-3p {sup 5}3d{sup 2} {sup 2}P{sub 1/2} transitions at 225.25 {+-} 0.12 and 226.35 {+-} 0.10 Angstrom-Sign , respectively. Seven lines in Fe XI, Fe XII, and Fe XIII between 200 and 205 Angstrom-Sign are noted for which the wavelengths in the CHIANTI database disagree with those in the current database of the National Institute of Standards and Technology. Our measurements of five of these lines appear to agree with the assignments used in CHIANTI.

  6. Follow-Up Study of Former Students of the Criminal Justice Program. Volume XVI, No. 4.

    ERIC Educational Resources Information Center

    Evans, George; Lucas, John A.

    A follow-up study was conducted at William Rainey Harper College (WRHC) of students who had completed several courses in the Criminal Justice Program to determine why students left the criminal justice field, examine Criminal Justice students' enrollment and course-taking patterns, and to analyze withdrawal and failure rates in the course,…

  7. Non-exponential nature of calorimetric and other relaxations: Effects of 2 nm-size solutes, loss of translational diffusion, isomer specificity, and sample size

    NASA Astrophysics Data System (ADS)

    Johari, G. P.; Khouri, J.

    2013-03-01

    Certain distributions of relaxation times can be described in terms of a non-exponential response parameter, β, of value between 0 and 1. Both β and the relaxation time, τ0, of a material depend upon the probe used for studying its dynamics and the value of β is qualitatively related to the non-Arrhenius variation of viscosity and τ0. A solute adds to the diversity of an intermolecular environment and is therefore expected to reduce β, i.e., to increase the distribution and to change τ0. We argue that the calorimetric value βcal determined from the specific heat [Cp = T(dS/dT)p] data is a more appropriate measure of the distribution of relaxation times arising from configurational fluctuations than β determined from other properties, and report a study of βcal of two sets of binary mixtures, each containing a different molecule of ˜2 nm size. We find that βcal changes monotonically with the composition, i.e., solute molecules modify the nano-scale composition and may increase or decrease τ0, but do not always decrease βcal. (Plots of βcal against the composition do not show a minimum.) We also analyze the data from the literature, and find that (i) βcal of an orientationally disordered crystal is less than that of its liquid, (ii) βcal varies with the isomer's nature, and chiral centers in a molecule decrease βcal, and (iii) βcal decreases when a sample's thickness is decreased to the nm-scale. After examining the difference between βcal and β determined from other properties we discuss the consequences of our findings for theories of non-exponential response, and suggest that studies of βcal may be more revealing of structure-freezing than studies of the non-Arrhenius behavior. On the basis of previous reports that β → 1 for dielectric relaxation of liquids of centiPoise viscosity observed at GHz frequencies, we argue that its molecular mechanism is the same as that of the Johari-Goldstein (JG) relaxation. Its spectrum becomes broader on

  8. MEASUREMENT AND MODELING OF Na-LIKE Fe XVI INNER-SHELL SATELLITES BETWEEN 14.5 A AND 18 A

    SciTech Connect

    Graf, A.; Beiersdorfer, P.; Brown, G. V.; Gu, M. F.

    2009-04-20

    We have used the University of California Lawrence Livermore National Laboratory's EBIT-I electron beam ion trap to perform measurements of the wavelengths and relative intensities of the X-ray lines from inner-shell satellite transitions in sodium-like Fe XVI. The measurements were carried out with high-resolution crystal and grating spectrometers and covered the 14.5-18 A wavelength band. In contrast to some predicted line strengths and positions found in the literature, our results show that the strongest relatively unblended inner-shell satellites of Fe XVI are located near 15.2 A. This is near the location of the 3d{yields} 2p intercombination line in Fe XVII. Calculations using the Flexible Atomic Code (FAC) are presented. The average deviation between the EBIT-I measurements and the FAC calculations for the wavelength positions and line ratios are 22 mA and a factor of 2.3, respectively, where the average is taken over the ten features included in this work.

  9. Magnetic structure in cool stars. XVI - Emissions from the outer atmosphere of M-type dwarfs

    NASA Technical Reports Server (NTRS)

    Rutten, R. G. M.; Zwaan, C.; Schrijver, C. J.; Duncan, D. K.; Mewe, R.

    1989-01-01

    Consideration is given to emission from the outer atmospheres of M-type dwarfs in several spectral lines originating from the chromosphere, the transition-region, and the soft X-ray emission from the corona. It is shown that M-type dwarfs systematically deviate from relations between flux densities in soft X-rays and chromospheric and transition-region emission lines. The quantitative relation between the equivalent width of H-alpha and the Ca II, H, and K emission index is determined. It is suggested that the emission in the Balmer spectrum may result from back heating by coronal soft X-rays.

  10. Comparative dose evaluations between XVI and OBI cone beam CT systems using Gafchromic XRQA2 film and nanoDot optical stimulated luminescence dosimeters

    SciTech Connect

    Giaddui, Tawfik; Cui Yunfeng; Galvin, James; Yu Yan; Xiao Ying

    2013-06-15

    Purpose: To investigate the effect of energy (kVp) and filters (no filter, half Bowtie, and full Bowtie) on the dose response curves of the Gafchromic XRQA2 film and nanoDot optical stimulated luminescence dosimeters (OSLDs) in CBCT dose fields. To measure surface and internal doses received during x-ray volume imager (XVI) (Version R4.5) and on board imager (OBI) (Version 1.5) CBCT imaging protocols using these two types of dosimeters. Methods: Gafchromic XRQA2 film and nanoDot OSLD dose response curves were generated at different kV imaging settings used by XVI (software version R4.5) and OBI (software version 1.5) CBCT systems. The settings for the XVI system were: 100 kVp/F0 (no filter), 120 kVp/F0, and 120 kVp/F1 (Bowtie filter), and for the OBI system were: 100 kVp/full fan, 125 kVp/full fan, and 125 kVp/half fan. XRQA2 film was calibrated in air to air kerma levels between 0 and 11 cGy and scanned using reflection scanning mode with the Epson Expression 10000 XL flat-bed document scanner. NanoDot OSLDs were calibrated on phantom to surface dose levels between 0 and 14 cGy and read using the inLight{sup TM} MicroStar reader. Both dosimeters were used to measure in field surface and internal doses in a male Alderson Rando Phantom. Results: Dose response curves of XRQA2 film and nanoDot OSLDs at different XVI and OBI CBCT settings were reported. For XVI system, the surface dose ranged between 0.02 cGy in head region during fast head and neck scan and 4.99 cGy in the chest region during symmetry scan. On the other hand, the internal dose ranged between 0.02 cGy in the head region during fast head and neck scan and 3.17 cGy in the chest region during chest M20 scan. The average (internal and external) dose ranged between 0.05 cGy in the head region during fast head and neck scan and 2.41 cGy in the chest region during chest M20 scan. For OBI system, the surface dose ranged between 0.19 cGy in head region during head scan and 4.55 cGy in the pelvis region during

  11. Oral Histories in Meteoritics and Planetary Science--XVI: Grenville Turner

    NASA Astrophysics Data System (ADS)

    Sears, Derek W. G.

    2012-03-01

    In this interview, Grenville Turner (Fig. 1) recounts how he became interested in meteorites during postdoctoral research with John Reynolds at the University of California, Berkeley, after completing a DPhil with Ken Mayne at the University of Oxford. At Berkeley, he worked on xenon isotopes with fellow students Bob Pepin and Craig Merrihue, but Reynolds' insistence that they analyze all the inert gases in their samples meant that they also made important contributions to Ne isotope studies and potassium-argon dating leading to the Ar-Ar technique. In 1964, Grenville obtained a teaching position at the University of Sheffield where he developed his own laboratory for inert gas isotope measurements. After the return of samples from the Moon by the Apollo program, he became involved in determining the chronology of volcanism and major impacts on the Moon. In 1988, Grenville and his team moved to the University of Manchester as part of a national reorganization of earth science departments. During the post Apollo years, Grenville's interest turned to the development of new instrumentation (resonance ionization mass spectrometry and the ion microprobe), and to problems in terrestrial isotope geochemistry, particularly the source of inert gases in fluid inclusions. He received the Leonard Medal of the Meteoritical Society in 1999, and he has also received awards from the Royal Society, the European Association of Geochemistry, and the Royal Astronomical Society.

  12. XVI Workshop on High Energy Spin Physics (D-SPIN2015)

    NASA Astrophysics Data System (ADS)

    Lednicky, Richard

    2016-02-01

    Dear Colleagues, Ladies and Gentlemen, on behalf of the Directorate of Joint Institute for Nuclear Research (JINR) it is a pleasure for me to welcome you here to Dubna for the 16th International Workshop on High Energy Spin Physics. It provides an opportunity to present and discuss the news accumulated during last year. Another important feature of this series of workshops has always been the participation of a large number of physicists from the former Soviet Union and Eastern European countries, for which long trips have previously been limited by financial (and earlier also by bureaucratic) reasons. It thus represents an important addition to the series of large International Symposia on spin physics held in even-numbered years in different countries, including the Symposium held in Dubna in 2012. JINR has a long-lasting tradition of experimental and theoretical studies of spin phenomena. The workshops on high energy spin physics started in Dubna in 1981 due to the initiative of L. Lapidus, an outstanding theoretical physicist. Since then, these meetings have been held in Dubna in every odd year and have become regular thanks to Anatoly Vasilievich Efremov, the chairman for many years. Recent years have brought a lot of new experimental results, and above all the discovery and determination of quantum characteristics of the Higgs boson at the Large Hadron Collider.

  13. 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.

  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. 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 (

  16. Calorimetric study of the superconducting and normal state properties of Ca(Fe1-xCox)2As2

    NASA Astrophysics Data System (ADS)

    Abdel-Hafiez, M.; Harnagea, L.; Singh, S.; Stockert, U.; Wurmehl, S.; Leps, N.; Klingeler, R.; Wolter, A. U. B.; Büchner, B.

    2012-12-01

    We present a calorimetric study on single crystals of Ca(Fe1-xCox)2As2 (x = 0, 0.032, 0.051, 0.056, 0.063, and 0.146). The combined first order spin-density wave/structural transition occurs in the parent CaFe2As2 compound at 168 K and gradually shifts to lower temperature for low doping levels (x = 0.032 and x = 0.051). It is completely suppressed upon higher doping x >= 0.056. Simultaneously, superconductivity appears at lower temperature with a transition temperature around Tc ~ 14.1 K for Ca(Fe0.937Co0.063)2As2. The phase diagram of Ca(Fe0.937Co0.063)2As2 has been derived and the upper critical field is found to be μ0H(c)2 = 11.5 T and μ0H(ab)c2 = 19.4 T for the c and ab directions, respectively.

  17. Kinetic and calorimetric study of the adsorption of dyes on mesoporous activated carbon prepared from coconut coir dust.

    PubMed

    Macedo, Jeremias de Souza; da Costa Júnior, Nivan Bezerra; Almeida, Luis Eduardo; Vieira, Eunice Fragoso da Silva; Cestari, Antonio Reinaldo; Gimenez, Iara de Fátima; Villarreal Carreño, Neftali Lênin; Barreto, Ledjane Silva

    2006-06-15

    Mesoporous activated carbon has been prepared from coconut coir dust as support for adsorption of some model dye molecules from aqueous solutions. The methylene blue (MB) and remazol yellow (RY) molecules were chosen for study of the adsorption capacity of cationic and anionic dyes onto prepared activated carbon. The adsorption kinetics was studied with the Lagergren first- and pseudo-second-order kinetic models as well as the intraparticle diffusion model. The results for both dyes suggested a multimechanism sorption process. The adsorption mechanisms in the systems dyes/AC follow pseudo-second-order kinetics with a significant contribution of intraparticle diffusion. The samples simultaneously present acidic and basic sites able to act as anchoring sites for basic and acidic dyes, respectively. Calorimetric studies reveal that dyes/AC interaction forces are correlated with the pH of the solution, which can be related to the charge distribution on the AC surface. These AC samples also exhibited very short equilibrium times for the adsorption of both dyes, which is an economically favorable requisite for the activated carbon described in this work, in addition to the local abundance of the raw material. PMID:16497318

  18. Spectroscopic and calorimetric investigations on the binding of phenazinium dyes safranine-O and phenosafranine to double stranded RNA polynucleotides.

    PubMed

    Saha, Baishakhi; Kumar, Gopinatha Suresh

    2016-08-01

    RNA targeting through small molecules that can selectively bind specific RNA structures is an important current strategy in therapeutic drug development. Towards this strategy a comparative study on the interaction of two phenazinium dyes, safranine-O and phenosafranine to double stranded RNAs, poly(I).poly(C), poly(A).poly(U) and poly(C).poly(G) was performed. Spectrophotometric and spectrofluorimetric studies revealed non-cooperative binding of the dyes to the duplex RNA with binding constants of the order 10(5)M(-1) with a higher affinity of safranine-O to poly(I).poly(C) followed by poly(A).poly(U) and poly(C).poly(G). Anisotropy and fluorescence quenching results confirmed an intercalation mode of binding for the dyes on these RNAs. Binding induced conformational changes in the RNA polynucleotides were revealed from circular dichroism data. Thermal melting study and DSC experiments demonstrated stabilization of dye-RNA complexes. Calorimetric studies revealed that the binding was accompanied by a large positive entropy term with a small negative enthalpy contributions. Significant hydrophobic forces in the complexation of the double stranded RNAs with the dyes were confirmed from the negative heat capacity changes. Enthalpy-entropy compensation was also observed in the binding. Parsing of the Gibbs energy suggested a larger non-electrostatic contribution in all the cases. The results presented here may be helpful to design new types of RNA-based therapeutic agents. PMID:27236048

  19. 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.

  20. Design and performance tests of the calorimetric tract of a Compton Camera for small-animals imaging

    NASA Astrophysics Data System (ADS)

    Rossi, P.; Baldazzi, G.; Battistella, A.; Bello, M.; Bollini, D.; Bonvicini, V.; Fontana, C. L.; Gennaro, G.; Moschini, G.; Navarria, F.; Rashevsky, A.; Uzunov, N.; Zampa, G.; Zampa, N.; Vacchi, A.

    2011-02-01

    The bio-distribution and targeting capability of pharmaceuticals may be assessed in small animals by imaging gamma-rays emitted from radio-isotope markers. Detectors that exploit the Compton concept allow higher gamma-ray efficiency compared to conventional Anger cameras employing collimators, and feature sub-millimeter spatial resolution and compact geometry. We are developing a Compton Camera that has to address several requirements: the high rates typical of the Compton concept; detection of gamma-rays of different energies that may range from 140 keV ( 99 mTc) to 511 keV ( β+ emitters); presence of gamma and beta radiation with energies up to 2 MeV in case of 188Re. The camera consists of a thin position-sensitive Tracker that scatters the gamma ray, and a second position-sensitive detection system to totally absorb the energy of the scattered photons (Calorimeter). In this paper we present the design and discuss the realization of the calorimetric tract, including the choice of scintillator crystal, pixel size, and detector geometry. Simulations of the gamma-ray trajectories from source to detectors have helped to assess the accuracy of the system and decide on camera design. Crystals of different materials, such as LaBr 3 GSO and YAP, and of different size, in continuous or segmented geometry, have been optically coupled to a multi-anode Hamamatsu H8500 detector, allowing measurements of spatial resolution and efficiency.

  1. Complete thermodynamic characterization of the multiple protonation equilibria of the aminoglycoside antibiotic paromomycin: a calorimetric and natural abundance 15N NMR study.

    PubMed

    Barbieri, Christopher M; Pilch, Daniel S

    2006-02-15

    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 pK(a) values for the five paromomycin amino groups, as well as the temperature dependence of these pK(a) values. These studies also indicate that the observed pK(a) 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 pK(a) is due to drug interactions with the sulfate counterions at the high drug concentrations (> or = 812 mM) used in the 15N NMR studies. Isothermal titration calorimetry studies conducted at drug concentrations < or = 45 microM 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 pK(a) 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 (deltaH) for protonation of the five paromomycin amino groups, as well as positive heat capacity changes (deltaC(p)) 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

  2. SU-E-J-50: An Evaluation of the Stability of Image Quality Parameters of the Elekta XVI and IView Imaging Systems

    SciTech Connect

    Stanley, D; Papanikolaou, N; Gutierrez, A

    2015-06-15

    Introduction Quality assurance of the image quality for image guided localization systems is crucial to ensure accurate visualization and localization of target volumes. In this study, the long term stability of selected image parameters was assessed and evaluated for CBCT mode, planar radiographic kV mode and MV mode. Methods and Materials: The CATPHAN, QckV-1 and QC-3 phantoms were used to evaluate the image quality parameters. The planar radiographic images were analyzed in PIPSpro™ with spatial resolution (f30, f40, f50) being recorded. For XVI CBCT, Head and Neck Small20 (S20) and Pelvis Medium20 (M20) standard acquisition modes were evaluated for Uniformity, Noise, Spatial Resolution and HU constancy. Dose and kVp for the XVI were recorded using the Unfors RaySafe Xi system with the R/F Low Detector for the kV planar radiographic mode. Results A total of 20 and 10 measurements were acquired for the planar radiographic and CBCT systems respectively over a two month period. Values were normalized to the mean and the standard deviations (STD) were recorded. For the planar radiographic spatial resolution, the STD for f30, f40, f50 were 0.004, 0.002, 0.002 and 0.005, 0.007, 0.008 for the kV and MV, respectively. The average recorded dose for kV was 38.7±2.7 μGy. The STD of the evaluated metrics for the S20 acquisition were: 0.444(f30), 0.067(f40), 0.062(f50), 0.018(Water/poly-HU constancy), 0.028(uniformity) and 0.106(noise). The standard deviations for the M20 acquisition were: 0.108(f30), 0.073(f40), 0.091(f50), 0.008(Water/poly-HU constancy), 0.005(uniformity) and 0.005(noise). Using these, tolerances can be reported as a warning and action threshold of 1σ and 2σ. Conclusion A study was performed to assess the stability of the basic image quality parameters recommended by TG-142 for the Elekta XVI and iView imaging systems. Consistent imaging and dosimetric properties over the evaluated time frame were noted. This work was funded in part by the Cancer

  3. The ruthenium-yttrium system: An experimental calorimetric study with a phase diagram optimization

    SciTech Connect

    Selhaoui, N.; Bouirden, L.; Charles, J.; Gachon, J.C.; Kleppa, O.J.

    1998-07-01

    After an experimental determination of the standard enthalpies of formation of Ru{sub 0.67}Y{sub 0.33} and Ru{sub 0.286}Y{sub 0.714}, the Ru-Y system was numerically assessed with help of NANCYUN software to check the consistency between the experimental results and the phase diagram proposed in the literature.

  4. Introduction of Differential Scanning Calorimetry in a General Chemistry Laboratory Course: Determination of Thermal Properties of Organic Hydrocarbons

    ERIC Educational Resources Information Center

    D'Amelia, Ronald; Franks, Thomas; Nirode, William F.

    2007-01-01

    In first-year general chemistry undergraduate courses, thermodynamics and thermal properties such as melting points and changes in enthalpy ([Delta]H) and entropy ([Delta]S) of phase changes are frequently discussed. Typically, classical calorimetric methods of analysis are used to determine [Delta]H of reactions. Differential scanning calorimetry…

  5. Thermogravimetric, Calorimetric, and Structural Studies of the Co3 O4 /CoO Oxidation/Reduction Reaction

    NASA Astrophysics Data System (ADS)

    Unruh, Karl; Cichocki, Ronald; Kelly, Brian; Poirier, Gerald

    2015-03-01

    To better assess the potential of cobalt oxide for thermal energy storage (TES), the Co3O4/CoO oxidation/reduction reaction has been studied by thermogravimetric (TGA), calorimetric (DSC), and x-ray diffraction (XRD) measurements in N2 and atmospheric air environments. TGA measurements showed an abrupt mass loss of about 6.6% in both N2 and air, consistent with the stoichiometric reduction of Co3O4 to CoO and structural measurements. The onset temperature of the reduction of Co3O4 in air was only weakly dependent on the sample heating rate and occurred at about 910 °C. The onset temperature for the oxidation of CoO varied between about 850 and 875 °C for cooling rates between 1 and 20 °C/min, but complete re-conversion to Co3O4 could only be achieved at the slowest cooling rates. Due to the dependence of the rate constant on the oxygen partial pressure, the oxidation of Co3O4 in a N2 environment occurred at temperatures between about 775 and 825 °C for heating rates between 1 and 20 °C/min and no subsequent re-oxidation of the reduced Co3O4 was observed on cooling to room temperature. In conjunction with a measured transition heat of about 600 J/g of Co3O4, these measurements indicate that cobalt oxide is a viable TES material.

  6. Spectroscopic and calorimetric studies on the binding of an indoloquinoline drug to parallel and antiparallel DNA triplexes.

    PubMed

    Riechert-Krause, Fanny; Autenrieth, Karolin; Eick, Andrea; Weisz, Klaus

    2013-01-01

    11-Phenyl-substituted indoloquinolines have been found to exhibit significant antiproliferative potency in cancer cells but to show only moderate affinity toward genomic double-helical DNA. In this study, parallel as well as antiparallel triple-helical DNA targets are employed to evaluate the triplex binding of these ligands. UV melting experiments with parallel triplexes indicate considerable interactions with the drug and a strong preference for TAT-rich triplexes in line with an increasing number of potential intercalation sites of similar binding strength between two TAT base triads. Via substitution of a singly charged aminoethylamine side chain by a longer and doubly charged bis(aminopropyl)amine substituent at the ligand, binding affinities increase and also start to exhibit long-range effects as indicated by a strong correlation between the binding affinity and the overall length of the TAT tract within the triplex stem. Compared to parallel triplexes, an antiparallel triplex with a GT-containing third strand constitutes a preferred target for the indoloquinoline drug. On the basis of pH-dependent titration experiments and corroborated by a Job analysis of continuous variation, binding of the drug to the GT triplex not only is strongly enhanced when the solution pH is lowered from 7 to 5 but also reveals a pH-dependent stoichiometry upon formation of the complex. Calorimetric data demonstrate that stronger binding of a protonated drug at acidic pH is associated with a more exothermic binding process. However, at pH 7 and 5, binding is enthalpically driven with additional favorable entropic contributions. PMID:23234257

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

    PubMed

    Fink, Cornel; Katsyuba, Sergey; Laurenczy, Gabor

    2016-04-20

    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. PMID:26890151

  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. PMID:21381636

  9. Calorimetric study of the entropy relation in the NaCl–KCl system

    PubMed Central

    Benisek, Artur; Dachs, Edgar

    2013-01-01

    The heat capacity of one Na-rich and two K-rich samples of the NaCl–KCl (halite–sylvite) crystalline solution was investigated between 5 and 300 K. It deviated positively from ideal behaviour with a maximum at 40 K. The thereby produced excess entropy at 298.15 K was described by a symmetric Margules mixing model yielding WmS = 8.73 J/mol/K. Using enthalpy of mixing data from the literature and our data on the entropy, the solvus was calculated for a pressure of 105 Pa and compared with the directly determined solvus. The difference between them can be attributed to the effect of Na–K short range ordering (clustering). PMID:24926102

  10. Calorimetric and transport properties of Zircalloy 2, Zircalloy 4, and Inconel 625

    NASA Astrophysics Data System (ADS)

    Maglić, K. D.; Perović, N. Lj.; Stanimirović, A. M.

    1994-07-01

    This paper presents the measurements and the results on thermal and electrical transport properties of three nuclear reactor cladding materials: Zircalloy 2, Zircalloy 4, and Inconel 625. Study of these materials constituted a part of the IAEA coordinated research program aimed at the generation and establishment of a reliable and complete database of the thermal properties of reactor materials. Measured properties include thermal diffusivity, specific heat, and electrical resistivity. Thermal diffusivity was measured by the laser pulse technique. Specific heat and electrical resistivity were measured using a millisecond-resolution direct electrical pulse heating technique. Thermal conductivity was computed from the experimentally determined thermal difusivity and specific heat functions and the room temperature density values. Measurements were performed in the 20 to 1500°C temperature range, depending on the material and property concerned.

  11. Calorimetric and transport properties of Zircalloy 2, Zircalloy 4, and Inconel 625

    SciTech Connect

    Maglic, K.D.; Perovic, N.Lj.; Stanimirovic, A.M.

    1994-07-01

    This paper presents the measurements and the results on thermal and electrical transport properties of three nuclear reactor cladding materials: Zircalloy 2, Zircalloy 4, and Inconel 625. Study of these materials constituted a part of the IAEA coordinated research program aimed at the generation and establishment of a reliable and complete database of the thermal properties of reactor materials. Measured properties include thermal diffusivity, specific heat, and electrical resistivity. Thermal diffusivity was measured by the laser pulse technique. Specific heat and electrical resistivity were measured using a millisecond-resolution direct electrical pulse heating technique. Thermal conductivity was computed from the experimentally determined thermal diffusivity and specific heat functions and the room temperature density values. Measurements were performed in the 20 to 1500{degrees}C temperature range, depending on the material and property concerned.

  12. Calorimetric study of the entropy relation in the NaCl-KCl system.

    PubMed

    Benisek, Artur; Dachs, Edgar

    2013-07-01

    The heat capacity of one Na-rich and two K-rich samples of the NaCl-KCl (halite-sylvite) crystalline solution was investigated between 5 and 300 K. It deviated positively from ideal behaviour with a maximum at 40 K. The thereby produced excess entropy at 298.15 K was described by a symmetric Margules mixing model yielding [Formula: see text] = 8.73 J/mol/K. Using enthalpy of mixing data from the literature and our data on the entropy, the solvus was calculated for a pressure of 10(5) Pa and compared with the directly determined solvus. The difference between them can be attributed to the effect of Na-K short range ordering (clustering). PMID:24926102

  13. [Calorimetric assay of yeast inorganic pyrophosphatase interaction with magnesium and phosphate ions].

    PubMed

    Vorob'eva, N N; Nazarova, T I; Bakuleva, N P; Avaeva, S M; Protasevich, I I

    1982-05-01

    The thermodynamic characteristics for the specific binding of one or two Mg2+ by the yeast inorganic pyrophosphatase and for the enzyme interaction with phosphate were determined. Saturation of the first binding site with Mg2+ causes structural rearrangements in the enzyme molecule without changing the temperature of protein denaturation. On the contrast, saturation of the second binding site results in stabilization of the system, i. e. a considerable fall in the entropy and a rise in the temperature of denaturation. Phosphorylation of the enzyme carboxylic group by inorganic phosphate requires saturation of the first binding site with Mg2+ and is not accompanied by changes in the enthalpy of the system. The pyrophosphate synthesis in the presence of the enzyme saturated with Mg2+ in both binding sites is associated with changes in the enthalpy and, possibly, in the entropy of the system. PMID:6124280

  14. Structure-energy relationship in barbituric acid: a calorimetric, computational, and crystallographic study.

    PubMed

    Roux, María Victoria; Temprado, Manuel; Notario, Rafael; Foces-Foces, Concepción; Emel'yanenko, Vladimir N; Verevkin, Sergey P

    2008-08-14

    This paper reports the value of the standard (p(o) = 0.1 MPa) molar enthalpy of formation in the gas phase at T = 298.15 K for barbituric acid. The enthalpies of combustion and sublimation were measured by static bomb combustion calorimetry and transference (transpiration) method in a saturated N2 stream and a gas-phase enthalpy of formation value of -(534.3 +/- 1.7) kJ x mol(-1) was determined at T = 298.15 K. G3-calculated enthalpies of formation are in very good agreement with the experimental value. The behavior of the sample as a function of the temperature was studied by differential scanning calorimetry, and a new polymorph of barbituric acid at high temperature was found. In the solid state, two anhydrous forms are known displaying two out of the six hydrogen-bonding patterns observed in the alkyl/alkenyl derivatives retrieved from the Cambridge Crystallographic Database. The stability of these motifs has been analyzed by theoretical calculations. X-ray powder diffraction technique was used to establish to which polymorphic form corresponds to the commercial sample used in this study and to characterize the new form at high temperature. PMID:18646743

  15. Calorimetric and X-ray studies of clathrate hydrates of tetraisoamylammonium polyacrylates.

    PubMed

    Terekhova, Irina S; Manakov, Andrey Yu; Soldatov, Dmitriy V; Suwinska, Kinga; Skiba, Sergey S; Stenin, Yuri G; Villevald, Galina V; Karpova, Tamara D; Yunoshev, Alexander S

    2009-04-30

    The structure of clathrate hydrates with tetraisoamylammonium polyacrylate salt incorporated as guest has been studied in this work. Also, quantitative studies on the stability changes of the clathrate hydrates with different degrees of cross-linking of the guest polymer (varied from 0 to 3%) have been conducted. A single crystal X-ray diffraction study of a crystal of the hydrate with linear (uncross-linked) tetraisoamylammonium polyacrylate as guest reveals a hexagonal structure (space group P6m2, a = 12.15 A, c =12.58 A at 100 K) with 39 host framework water molecules per one guest monomeric unit. Powder X-ray diffraction analyses confirm the identity of the above crystal structure of the hydrate with linear guest polymer and the crystal structure of the hydrates with cross-linked guest (hexagonal, a = 12.25 A, c =12.72 A at 276 K). In order to quantitatively determine the stability differences of the hydrates with the included guests having various degrees of cross-linking of the anionic chain, a series of differential scanning calorimetry measurements of the fusion enthalpy of the hydrate samples has been carried out. On the basis of the results obtained, a structural model describing the decrease in the stability of the clathrate hydrates with tetraisoamylammonium polyacrylate guest as a function of the degree of cross-linking of the guest polymer has been suggested. PMID:19344169

  16. Isolation of lactoferrin from milk of different species: calorimetric and antimicrobial studies.

    PubMed

    Conesa, Celia; Sánchez, Lourdes; Rota, Carmen; Pérez, María-Dolores; Calvo, Miguel; Farnaud, Sebastien; Evans, Robert W

    2008-05-01

    Lactoferrin (LF) is an iron-binding glycoprotein found in different biological fluids of mammals and in neutrophils. It has been proposed to be involved in many functions, including protection from pathogens. In this work, purification of lactoferrin using an ion-exchange chromatography (SP-Sepharose) was attempted for the milk of the following animals: sheep (Ovis aries), goat (Capra hircus), camel (Camelus bactrianus), alpaca (Lama pacos), elephant (Elephas maximus) and grey seal (Halichoerus grypus), as well as human (Homo sapiens). Lactoferrin was identified in all the milks apart from that from grey seal. The thermal stability of the purified lactoferrins, in their native and iron-saturated forms, was studied by differential scanning calorimetry (DSC). Maximum temperature, onset temperature and enthalpy change of denaturation were higher when lactoferrins were saturated with iron than in their native form, indicating an increase in the stability of the protein structure upon iron-binding. Human lactoferrin was found to be the most heat-resistant and the other lactoferrins presented different degrees of thermoresistance, that of elephant being the least resistant. The antimicrobial activity of the different isolated lactoferrins was investigated against Escherichia coli 0157:H7. The minimal inhibitory concentrations (MICs) were determined by measuring the absorbance at 620 nm. The minimum bactericidal concentrations (MBCs) were also measured and it was found that camel lactoferrin was the most active lactoferrin against E. coli 0157:H7, whereas alpaca and human lactoferrins were the least active. PMID:18387837

  17. Differential Scanning Calorimetric (DSC) Analysis of Rotary Nickel-Titanium (NiTi) Endodontic File (RNEF)

    NASA Astrophysics Data System (ADS)

    Wu, Ray Chun Tung; Chung, C. Y.

    2012-12-01

    To determine the variation of A f along the axial length of rotary nickel-titanium endodontic files (RNEF). Three commercial brands of 4% taper RNEF: GTX (#20, 25 mm, Dentsply Tulsa Dental Specialties, Tulsa, OK, USA), K3 (#25, 25 mm) and TF (Twisted File #25, 27 mm) (Sybron Kerr, Orange, CA, USA) were cut into segments at 4 mm increment from the working tip. Regional specimens were measured for differential heat-flow over thermal cycling, generally with continuous heating or cooling (5 °C/min) and 5 min hold at set temperatures (start, finish temperatures): GTX: -55, 90 °C; K3: -55, 45 °C; TF: -55, 60 °C; using differential scanning calorimeter. This experiment demonstrated regional differences in A f along the axial length of GTX and K3 files. Similar variation was not obvious in the TF samples. A contributory effect of regional difference in strain-hardening due to grinding and machining during manufacturing is proposed.

  18. Structural and binding properties of laminarin revealed by analytical ultracentrifugation and calorimetric analyses.

    PubMed

    Oda, Masayuki; Tanabe, Yoichi; Noda, Masanori; Inaba, Satomi; Krayukhina, Elena; Fukada, Harumi; Uchiyama, Susumu

    2016-08-01

    One of the β-1,3-glucans, laminarin, has been widely used as a substrate for enzymes including endo-1,3-β-glucanase. To obtain quantitative information about the molecular interaction between laminarin and endo-1,3-β-glucanase, the structural properties of laminarin should be determined. The results from pioneering work using analytical ultracentrifugation for carbohydrate analysis showed that laminarin from Laminaria digitata predominantly exists as a single-chain species with approximately 5% of triple-helical species. Differential scanning calorimetry experiments did not show a peak assignable to the transition from triple-helix to single-chain, supporting the notion that a large proportion of laminarin is the single-chain species. The interaction of laminarin with an inactive variant of endo-1,3-β-glucanase from Cellulosimicrobium cellulans, E119A, was quantitatively analyzed using isothermal titration calorimetry. The binding was enthalpically driven and the binding affinity was approximately 10(6) M(-1). The results from binding stoichiometric analysis indicated that on average, E119A binds to laminarin in a 2:1 ratio. This seems to be reasonable, because laminarin mainly exists as a monomer, the apparent molecular mass of laminarin is 3.6 kDa, and E119A would have substrate-binding subsites corresponding to 6 glucose units. The analytical ultracentrifugation experiments could detect different complex species of laminarin and endo-1,3-β-glucanase. PMID:27267066

  19. Synthesis, calorimetric, structural and conductivity studies in a new thallium selenate tellurate adduct compound

    SciTech Connect

    Ktari, L.; Abdelhedi, M.; Bouhlel, N.; Dammak, M.; Cousson, A.

    2009-08-05

    The crystal structure of the thallium selenate tellurate Tl{sub 2}SeO{sub 4}.Te(OH){sub 6} (TlSeTe) was determined by X-ray diffraction method. The title compound crystallizes in the monoclinic system with P2{sub 1}/c space group. The following parameters are: a = 12.358(3) A; b = 7.231(1) A; c = 11.986(2) A; {beta} = 111.092(2){sup o}; Z = 4. The structure can be regarded as being built of isolated TeO{sub 6} octahedra and SeO{sub 4} tetrahedra. The Tl{sup +} cations are intercalated between these kinds of polyhedra. The main feature of this structure is the coexistence of two different and independent anions (SeO{sub 4}{sup 2-} and TeO{sub 6}{sup 6-}) in the same unit cell. The structure is stable due to O-H...O hydrogen bonds which link tetrahedral and octahedral groups. Crystals of Tl{sub 2}SeO{sub 4}.Te(OH){sub 6} undergo three endothermal transitions at 373, 395 and 437 K. These transitions are detected by DSC and analyzed by dielectric measurements with impedance spectroscopy. The evolution of conductivity versus temperature showed the presence of a protonic conduction phase transition at 437 K. The phase transition at 373 K can be related to a structural phase transition, whereas the one at 395 K is ascribed as likely due to a ferroelectric-paraelectric phase transition.

  20. Thermodynamic properties of autunite, uranyl hydrogen phosphate, and uranyl orthophosphate from solubility and calorimetric measurements

    SciTech Connect

    Gorman-Lewis, Drew; Shareva, Tatiana; kubatko, Karrie-Ann; burns, Peter; Wellman, Dawn M.; McNamara, Bruce K.; szymanowski, jennifer; Navrotsky, Alexandra; Fein, Jeremy B.

    2009-10-01

    In this study, we use solubility and oxide melt solution calorimetry measurements to determine the thermodynamic properties of the uranyl phosphate phases autunite (abbreviated: CaUP), uranyl hydrogen phosphate (HUP), and uranyl orthophosphate (UP). Solubility measurements from both supersaturated and undersaturated conditions, as well as under different pH conditions, rigorously demonstrate attainment of equilibrium and yield well-constrained solubility product values of -48.36 (-0.03 /+ 0.03), -13.17 (-0.11 / +0.07), and -49.36 (-0.04 / +0.02) for CaUP, HUP, and UP, respectively. We use the solubility data to calculate standard state Gibbs free energies of formation for all phases (-7630.61 ± 9.69, -3072.27 ± 4.76, and -6138.95 ± 12.24 kJ mol-1 for CaUP, HUP, and UP, respectively), and calorimetry data to calculate standard state enthalpies of formation of -3223.22 ± 4.00 and -7001.01 ± 15.10 kJ mol-1 for HUP and UP, respectively. Combining these results allows us also to calculate the standard state entropies of formation of -506.54 ± 10.48 and -2893.12 ± 19.44 kJ mol-1 K-1 for HUP and UP phases, respectively. The results from this study are part of a combined effort to develop reliable and internally consistent thermodynamic data for environmentally relevant uranyl minerals. Data such as these are required in order to optimize and quantitatively assess the effect of phosphate amendment remediation technologies for uranium contaminated systems.

  1. Thermochemistry of alkyl pyridinium bromide ionic liquids: calorimetric measurements and calculations.

    PubMed

    Tong, Bo; Liu, Qing-Shan; Tan, Zhi-Cheng; Welz-Biermann, Urs

    2010-03-25

    Two ionic liquids, 1-ethylpyridinium bromide (EPBr) and 1-propylpyridinium bromide (PPBr), were prepared and the structures were characterized by 1H NMR. The thermodynamic properties of EPBr and PPBr were studied with adiabatic calorimetry (AC) and thermogravimatric analysis (TG-DTG). The heat capacity was precisely measured in the temperature range from 78 to 410 K by means of a fully automated adiabatic calorimeter. For EPBr, the melting temperature, enthalpy, and entropy of solid-liquid phase transition were determined to be 391.31 +/- 0.28 K, 12.77 +/- 0.09 kJ x mol(-1), and 32.63 +/- 0.22 J x K(-1) x mol(-1), respectively, and for PPBr they were 342.83 +/- 0.69 K, 10.97 +/- 0.05 kJ x mol(-1), and 32.00 +/- 0.10 J x K(-1) x mol(-1), respectively. The thermodynamic functions (H(T)(0) - H(298.15)(0)) and (S(T)(0) - S(298.15)(0)) were derived from the heat capacity data in the experimental temperature range with an interval of 5 K. The thermostablility of the compounds was further studied by TGA measurements. The phase change behavior and thermodynamic properties were compared and estimated in a series of alkyl pyridinium bromide ionic liquids. Results indicate that EPBr has higher melting and decomposition temperature, as well as phase transition enthalpy and entropy but lower heat capacity than PPBr due to their different molecular structures. PMID:20235601

  2. 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. PMID:26073991

  3. Calorimetric studies of the interactions of metalloenzyme active site mimetics with zinc-binding inhibitors.

    PubMed

    Robinson, Sophia G; Burns, Philip T; Miceli, Amanda M; Grice, Kyle A; Karver, Caitlin E; Jin, Lihua

    2016-07-19

    The binding of drugs to metalloenzymes is an intricate process that involves several interactions, including binding of the drug to the enzyme active site metal, as well as multiple interactions between the drug and the enzyme residues. In order to determine the free energy contribution of Zn(2+) binding by known metalloenzyme inhibitors without the other interactions, valid active site zinc structural mimetics must be formed and binding studies need to be performed in biologically relevant conditions. The potential of each of five ligands to form a structural mimetic with Zn(2+) was investigated in buffer using Isothermal Titration Calorimetry (ITC). All five ligands formed strong 1 : 1 (ligand : Zn(2+)) binary complexes. The complexes were used in further ITC experiments to study their interaction with 8-hydroxyquinoline (8-HQ) and/or acetohydroxamic acid (AHA), two bidentate anionic zinc-chelating enzyme inhibitors. It was found that tetradentate ligands were not suitable for creating zinc structural mimetics for inhibitor binding in solution due to insufficient coordination sites remaining on Zn(2+). A stable binary complex, [Zn(BPA)](2+), which was formed by a tridentate ligand, bis(2-pyridylmethyl)amine (BPA), was found to bind one AHA in buffer or a methanol : buffer mixture (60 : 40 by volume) at pH 7.25 or one 8-HQ in the methanol : buffer mixture at pH 6.80, making it an effective structural mimetic for the active site of zinc metalloenzymes. These results are consistent with the observation that metalloenzyme active site zinc ions have three residues coordinated to them, leaving one or two sites open for inhibitors to bind. Our findings indicate that Zn(BPA)X2 can be used as an active site structural mimetic for zinc metalloenzymes for estimating the free energy contribution of zinc binding to the overall inhibitor active site interactions. Such use will help aid in the rational design of inhibitors to a variety of zinc metalloenzymes

  4. Enthalpies and entropies of proton and cadmium adsorption onto Bacillus subtilis bacterial cells from calorimetric measurements

    NASA Astrophysics Data System (ADS)

    Gorman-Lewis, Drew; Fein, Jeremy B.; Jensen, Mark P.

    2006-10-01

    We used titration calorimetry to measure the bulk heats of proton and Cd adsorption onto a common Gram positive soil bacterium Bacillus subtilis at 25.0 °C. Using the 4-site non-electrostatic model of Fein et al. [Fein, J.B., Boily, J.-F., Yee, N., Gorman-Lewis, D., Turner, B.F., 2005. Potentiometric titrations of Bacillus subtilis cells to low pH and a comparison of modeling approaches. Geochim. Cosmochim. Acta69 (5), 1123-1132.] to describe the bacterial surface reactivity to protons, our bulk enthalpy measurements can be used to determine the following site-specific enthalpies of proton adsorption for Sites 1-4, respectively: -3.5 ± 0.2, -4.2 ± 0.2, -15.4 ± 0.9, and -35 ± 2 kJ/mol, and these values yield the following third law entropies of proton adsorption onto Sites 1-4, respectively: +51 ± 4, +78 ± 4, +79 ± 5, and +60 ± 20 J/mol K. An alternative data analysis using a 2-site Langmuir-Freundlich model to describe proton binding to the bacterial surface (Fein et al., 2005) resulted in the following site-specific enthalpies of proton adsorption for Sites 1 and 2, respectively: -3.6 ± 0.2 and -35.1 ± 0.3 kJ/mol. The thermodynamic values for Sites 1-3 for the non-electrostatic model and Site 1 of the Langmuir-Freundlich model of proton adsorption onto the bacterial surface are similar to those associated with multifunctional organic acid anions, such as citrate, suggesting that the protonation state of a bacterial surface site can influence the energetics of protonation of neighboring sites. Our bulk Cd enthalpy data, interpreted using the 2-site non-electrostatic Cd adsorption model of Borrok et al. [Borrok, D., Fein, J.B., Tischler, M., O'Loughlin, E., Meyer, H., Liss, M., Kemner, K.M., 2004b. The effect of acidic solutions and growth conditions on the adsorptive properties of bacterial surfaces. Chem. Geol.209 (1-2), 107-119.] to account for Cd adsorption onto B. subtilis, yield the following site-specific enthalpies of Cd adsorption onto bacterial

  5. Calorimetric and x-ray diffraction studies of rye glucocerebroside mesomorphism.

    PubMed

    Lynch, D V; Caffrey, M; Hogan, J L; Steponkus, P L

    1992-05-01

    Glucocerebrosides (GlcCer) isolated from the leaves of winter rye (Secale cereale L. cv Puma) differ from the more commonly investigated natural and synthetic cerebrosides, in that greater than 95% of the fatty acids are saturated and monounsaturated hydroxy fatty acids. Isomers of the trihydroxy long chain base hydroxysphingenine (t1(8:18 cis or trans)) and isomers of sphingadienine (d18:2(4trans, 8 cis or trans)) comprise 77% and 17%, respectively, of the total long chain bases. The phase behavior of fully hydrated and dry rye leaf GlcCer was investigated using differential scanning calorimetry (DSC) and x-ray diffraction. On initial heating, aqueous dispersions of GlcCer exhibit a single endothermic transition at 56 degrees C and have an enthalpy (delta H) of 46 J/g. Cooling to 0 degrees C is accompanied by a small exothermic transition (delta H = -8 J/g) at 8 degrees C. On immediate reheating, a broad exothermic transition (delta H = -39 J/g) is observed between 10 and 20 degrees C in addition to a transition at 56 degrees C. These transitions are not reversible, and the exothermic transition rapidly diminishes when the sample is held at low temperature. Using x-ray diffraction, it was determined that the endotherm at 56 degrees C represents a transition from a highly ordered lamellar crystalline phase (Lc) with a d-spacing of 57 A and a series of wide-angle reflections in the 3-10 A range, to a lamellar liquid crystalline (L alpha) phase having a d-spacing of 55 A and a diffuse wide-angle scattering peak centered at 4.7 A. Cooling leads to the formation of a metastable gel phase (L beta) with a d-spacing of 64.0 A and a single broad reflection at 4.28 A. Subsequent warming to above 15 degrees C restores the original Lc phase. Thus, rye GlcCer in excess water exhibit a series of irreversible transitions and gel phase metastability. Dry GlcCer undergo an initial heating endothermic transition at 130 degrees C, which is ascribed to a transformation into the HII

  6. Acyclic diterpene glycosides, capsianosides VIII, IX, X, XIII, XV and XVI from the fruits of Paprika Capsicum annuum L. var. grossum BAILEY and Jalapeño Capsicum annuum L. var. annuum.

    PubMed

    Lee, Jong-Hyun; Kiyota, Naoko; Ikeda, Tsuyoshi; Nohara, Toshihiro

    2006-10-01

    Paprika and Jalapeño are used as vegetables and spices. We have obtained six new acyclic diterpene glycosides, called capsianosides XIII (2), XV (3), IX (4), XVI (5), X (6) and VIII (7) together with known capsianoside II (1) from the fruits of the Paprika and Jalapeño. The structures of these compounds have been elucidated by the (1)H- and (13)C-NMR spectra and two-dimensional NMR methods. PMID:17015971

  7. 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

  8. Introduction of Differential Scanning Calorimetry in a General Chemistry Laboratory Course: Determination of Heat Capacity of Metals and Demonstration of Law of Dulong and Petit

    ERIC Educational Resources Information Center

    D'Amelia, Ronald P.; Stracuzzi, Vincent; Nirode, William F.

    2008-01-01

    Today's general chemistry students are introduced to many of the principles and concepts of thermodynamics. In first-year general chemistry undergraduate courses, thermodynamic properties such as heat capacity are frequently discussed. Classical calorimetric methods of analysis and thermal equilibrium experiments are used to determine heat…

  9. 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.

  10. Calorimetric Study of Phase Stability and Phase Transformation in U- xZr ( x = 2, 5, 10 wt pct) Alloys

    NASA Astrophysics Data System (ADS)

    Rai, Arun Kumar; Subramanian, Raju; Hajra, Raj Narayan; Tripathy, Haraprasanna; Rengachari, Mythili; Saibaba, Saroja

    2015-11-01

    A comprehensive calorimetric study of high-temperature phase equilibria and phase transformation characteristics in U- xZr ( x = 2, 5, 10 wt pct) alloys has been undertaken, as a function of heating and cooling rates. It is found that the following sequence of phase transformation takes place upon slow heating in annealed U-2 wt pct Zr alloy: α + α' + δ-UZr2 → α + γ 2 → β + γ 2 → β + γ 1 → γ. For alloys of 5 and 10 wt pct Zr, the additional presence of a miscibility gap ( γ 1 U-rich bcc + γ 2 Zr-rich bcc) in the high-temperature γ(bcc) phase region resulted in the following transformation sequence: α + α' + δ-UZr2 → α + γ 2 → β + γ 2 → γ 1 + γ 2 → γ. Further, it has been demonstrated that depending on the nature of starting microstructure, namely whether it is α eq + δ-UZr2, or a mix of α' + α eq + δ-UZr2 phases, the relative extents of two possible co-occurring modes of the first on-heating phase transformation step differ. In case of starting microstructure having mixture of three phases α' + α eq + δ-UZr2, it is found that α'-martensite relaxation via α' + α eq + δ-UZr2 → α eq + δ-UZr2 constitutes the first on-heating thermal response. The α'-martensitic relaxation is very closely followed by the dissolution of δ-UZr2. The co-occurrence of these two events gives rise to a composite thermal arrest in a normal dynamic calorimetry profile. However, if the starting microstructure is the one having the equilibrium mix of α eq and δ-UZr2, then only the peritectoidal dissolution of δ-UZr2 is found in the calorimetry profile. Unless, a very slow cooling rate of the order of 0.1 K min-1 is adopted from high-temperature γ(bcc) phase, it is not possible to obtain 100 pct of α eq phase along with equilibrium amount of δ-UZr2. At normal and high cooling rates, it is possible to suppress the diffusional decomposition of γ to varying extents. The direct γ → α'-martensite transformation has been observed at

  11. THE IRON PROJECT AND THE RMAX PROJECT: Radiative and CollisionalProcesses of Iron Ions - Fe I, Fe II, Fe XVI, Fe XVII

    NASA Astrophysics Data System (ADS)

    Montenegro, Maximiliano; Nahar, Sultana; Pradhan, Anil; Sur, Chiranjib

    2008-05-01

    Results from work in progress under the Iron Project and Rmax Project on electron impact excitation and radiative processes of photo-excitations, photoionization and electron-ion recombination will be reported. Whereas the Iron Project is involved in scattering and radiative atomic processes of iron and iron-peak elements, and the Rmax Project aims particularly at the X-ray spectroscopy of astrophysical objects. We will present (i) collision strengths of Fe II at low energies using an accurate wavefunction needed for spectral analysis of infrared region, (ii) oscillator strengths and radiative decay rates for allowed and forbidden transitions in Fe I and Fe II, (iii) photoionization and electron-ion recombination of ground state of Fe XVI for over a large energy/temperature range up to and including K-shell ionization and core excitations as observed in X-ray spectra, and (iv) photoionization cross sections of large number fine structure levels (n<=10 and 0 <= 10) needed for astrophysical and modeling work. Relativistic approach in the Breit-Pauli approximation is being employed to study these atomic processes.

  12. Emission-Line Spectra of Ar IX-Ar XVI in the Soft X-Ray Region 20-50 Å

    NASA Astrophysics Data System (ADS)

    Lepson, J. K.; Beiersdorfer, P.; Behar, E.; Kahn, S. M.

    2003-06-01

    As part of a larger project to complete a comprehensive catalog of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EBIT-II, we present observations of argon lines in the extreme-ultraviolet region. Our database includes wavelength measurements with standard errors, relative intensities, and line assignments for Ar IX-Ar XVI between 20 and 50 Å. The experimental data are complemented with a full set of calculations using the Hebrew University Lawrence Livermore Atomic Code (HULLAC). Despite differences in calculated and measured wavelengths, we find the calculated lines to be of great utility in analyzing our laboratory spectra. The calculated line intensities are generally sufficient to identify the strongest transitions in each charge state. We note, however, an underestimation by theory of the strength of the 3s-->2p lines relative to the 3d-->2p lines in Ar IX, Ar X, and Ar XI. The laboratory data are compared with Chandra observations of Procyon, resulting in the identification of an Ar IX line that was previously thought to be from S IX.

  13. A spectroscopic and calorimetric study of the melting behaviors of a "bent" and a "normal" DNA duplex: [d(GA4T4C)]2 versus [d(GT4A4C)]2.

    PubMed Central

    Park, Y W; Breslauer, K J

    1991-01-01

    We have calorimetrically detected and energetically characterized a premelting event in the "bent" duplex [d(GA4T4C)]2 that is absent in the "normal" duplex [d(GT4A4C)]2. This premelting may correspond to the thermally induced "unbending" of the duplex. Specifically, we have used a combination of spectroscopic and calorimetric techniques to evaluate whether differences in the electrophoretic and hydrogen exchange properties of the bent duplex, [d(GA4T4C)]2, and the normal duplex, [d(GT4A4C)]2, are paralleled by differences in the equilibrium melting properties of these duplexes. Our results reveal that the bimolecular global meltings of both duplexes exhibit two-state behavior and are characterized by the expected thermodynamic changes, as well as the expected salt-dependencies. Significantly, however, at temperatures below duplex melting and over a similar temperature range in which the aberrant electrophoretic mobility is observed (approximately less than 35 degrees C), the bent duplex exhibits calorimetric premelting behavior absent in the normal duplex. Analysis of the calorimetric data in this preglobal melting domain (approximately less than 35 degrees C) allows us to estimate a lower-limit value of 1.6 kcal/(mol-base pair) for the thermally induced unbending of the decameric duplex. PMID:1996356

  14. Calorimetric Studies of the Energetics of Order-Disorder in the System Mg(1-x)Fe(x)Ca(CO(3))(2)

    SciTech Connect

    Brady, P.; Dooley, D.; Navrotsky, A.; Reeder, R.

    1999-02-10

    Calorimetric studies by Chai and Navrotsky (1996) on dolomite-ankerite energetic have been extended by including two additional types of samples: a very disordered stoichiometric MgCa(CO{sub 3}){sub 2} prepared from low temperature aqueous solution and three largely ordered natural samples of intermediate iron content. Combining these data with previous work, three distinct trends of energetic can be seen: those for samples with nearly complete order, nearly complete disorder, and intermediate order. From these trends, the enthalpy of complete disordering is estimated to be 33 {+-} 6 kJ/mol for MgCa(CO{sub 3}){sub 2} and 18 {+-} 5 kJ/mol for FeCa(CO{sub 3}){sub 2}.

  15. 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.

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

    NASA Astrophysics Data System (ADS)

    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.; SuperCDMS Collaboration

    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 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.

  17. Thermodynamic properties of illite, smectite and beidellite by calorimetric methods: Enthalpies of formation, heat capacities, entropies and Gibbs free energies of formation

    NASA Astrophysics Data System (ADS)

    Gailhanou, H.; Blanc, P.; Rogez, J.; Mikaelian, G.; Kawaji, H.; Olives, J.; Amouric, M.; Denoyel, R.; Bourrelly, S.; Montouillout, V.; Vieillard, P.; Fialips, C. I.; Michau, N.; Gaucher, E. C.

    2012-07-01

    The thermodynamic properties of three aluminous 2:1 clay minerals were acquired at 1.013 bars and at temperatures between 5 and 500 K using various calorimetric methods. Calorimetric measurements were performed on hydrated and dehydrated <2 μm clay fractions of smectite MX-80 (Wyoming), illite IMt-2 (Silver Hill) and beidellite SBId-1 (Black Jack Mine). After purification, the mineralogical analyses gave the following structural formulae: Na0.409K0.024Ca0.009 (Si3.738Al0.262) (Al1.598Mg0.214Fe 0.173 3 + Fe 0.035 2 +)O10(OH)2,K0.762Na0.044 (Si3.387Al0.613) (Al1.427Mg0.241Fe 0.292 3 + Fe 0.084 2 +)O10(OH)2 and Ca0.185K0.104 (Si3.574Al0.426) (Al1.812Mg0.09Fe 0.112 3 +)O10(OH)2 for smectite MX-80, illite IMt-2 and beidellite SBId-1, respectively. Heat capacities were measured by low temperature adiabatic calorimetry and differential scanning calorimetry, from 5 to 500 K. Standard enthalpies of formation were obtained from solution-reaction calorimetry at 298.15 K. The standard Gibbs free energies of formation of the clay minerals were also calculated, together with the equilibrium constants at 25 °C, for anhydrous and hydrated minerals. A comparison between these experimental data and estimated values obtained from prediction models available in the literature, enabled the calculation method that appears to be the most relevant to be selected, at least for aluminous 2:1 clay minerals.

  18. Determination of drug load in porous silicon microparticles by calorimetry

    NASA Astrophysics Data System (ADS)

    Salonen, J.; Paski, J.; Vähä-Heikkilä, K.; Heikkilä, T.; Björkqvist, M.; Lehto, V.-P.

    2005-06-01

    Different kind of drugs can be loaded into the porous silicon microparticles for oral dosing. In cases where the drug is in its crystalline form in the pores, the amount of the loaded drug can be determined accurately using a calorimetric method, thermoporometry. Even if the drug substance is not in crystalline form a sophisticated estimation can be given. In this work ibuprofen, antipyrine, and ranitidine have been studied. Ibuprofen and antipyrine were easily detected and quantified, but ranitidine, which does not penetrate into the PSi microparticles in its crystalline form, could only be qualitatively determined. The possibility to quantify this kind of drug substance is also discussed.

  19. The Bayer Facts of Science Education XVI: US STEM Workforce Shortage— Myth or Reality? Fortune 1000 Talent Recruiters on the Debate

    NASA Astrophysics Data System (ADS)

    Bayer Corporation

    2014-10-01

    A major debate is currently underway in the USA about whether there is, in fact, a science, technology, engineering and mathematics (STEM) workforce shortage in the country or not. This is the subject of the Bayer Facts of Science Education XVI: US STEM Workforce Shortage—Myth or Reality? Fortune 1000 Talent Recruiters on the Debate. An ongoing public opinion research project commissioned by Bayer Corporation, the Bayer Facts surveys examine US STEM education, diversity and workforce issues. The 16th in the series, the newest survey asks talent recruiters at some of the country's largest employers—those included in the Fortune 1000—to weigh in on current and future demand for new hires with 2- and 4-year STEM degrees. As professionals responsible for scouting, recruiting and hiring talent at Fortune 1000 companies, both STEM and non-STEM alike, these individuals are on the frontlines, tasked with assessing and filling their companies' workforce needs. The survey asks the recruiters whether new hires with 2- and 4-year STEM degrees are as, more or less in demand than their peers without STEM degrees? Are more new STEM jobs being created at their companies than non-STEM jobs? Can they find adequate numbers of qualified candidates in a timely manner and how fierce is the competition for STEM degree holders? To answer these and other questions, the survey polled 150 talent recruiters at Fortune 1000 companies, both STEM and non-STEM alike. The survey also asks the recruiters about diversion in STEM, workforce diversity in the pipeline, the role of community colleges in developing the STEM pipeline and the desired skills and competencies of new hires.

  20. 78 FR 11939 - Social Security Ruling, SSR 13-2p.; Titles II and XVI: Evaluating Cases Involving Drug Addiction...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-20

    .... The DSM-IV-TR does not include diagnoses for Caffeine Dependence or Caffeine Abuse. Fetal alcohol syndrome, Fetal cocaine exposure, or ] Addiction to, or use of, prescription medications taken as... he or she stopped using drugs or alcohol; that is, we will determine whether DAA is ``material''...

  1. A calorimetric determination of the enthalpy of formation and a description of the defect structure of the ordered beta-phase /Ni, Cu/ /1-x/ Al/x/

    NASA Technical Reports Server (NTRS)

    Henig, E. T.; Lukas, H. L.

    1988-01-01

    In order to describe thermodynamically the defect structure of an ordered B-Hume-Rothery phase, the heat of formation of (Ni,Cu)(1-x)Al(x) was measured at 1100 K as a function of concentration in the range x (sub Al) = 0.4 and 0.55 for three substitution rations x (sub Ni)/x (sub Cu) = infinity; 11; 5. The heat of formation of the NiAl beta-phase is strongly negative. For the stoichiometric composition it is -72.2 kJ/g-atom. On both the nickel-rich side and the aluminum-rich side the magnitude of the enthalpy of formation decreases linearly with concentration. Substitution of nickel for copper decreases the magnitude of the enthalpy of formation over the entire homogeneity range for the phase (Ni,Cu)(1-x)Al(x). The curve for the enthalpy of formation as well as the literature values for the chemical potential of aluminum are described with great accuracy by the disorder model of Wagner-Schottky.

  2. An active thermal control surfaces experiment. [spacecraft temperature determination

    NASA Technical Reports Server (NTRS)

    Wilkes, D. R.; Brown, M. J.

    1979-01-01

    An active flight experiment is described that has the objectives to determine the effects of the low earth natural environment and the Shuttle induced environment on selected thermal control and optical surfaces. The optical and thermal properties of test samples will be measured in-situ using an integrating sphere reflectrometer and using calorimetric methods. This experiment has been selected for the Long Duration Exposure Facility (LDEF) flight which will be carried to orbit by the NASA Space Shuttle. The LDEF will remain in orbit to be picked up by a later Shuttle mission and returned for postflight evaluation.

  3. Calorimetric study of crystal growth of ice in hydrated methemoglobin and of redistribution of the water clusters formed on melting the ice.

    PubMed Central

    Sartor, G; Mayer, E

    1994-01-01

    Calorimetric studies of the melting patterns of ice in hydrated methemoglobin powders containing between 0.43 and 0.58 (g water)/(g protein), and of their dependence on annealing at subzero temperatures and on isothermal treatment at ambient temperature are reported. Cooling rates were varied between approximately 1500 and 5 K min-1 and heating rate was 30 K min-1. Recrystallization of ice during annealing is observed at T > 228 K. The melting patterns of annealed samples are characteristically different from those of unannealed samples by the shifting of the melting temperature of the recrystallized ice fraction to higher temperatures toward the value of "bulk" ice. The "large" ice crystals formed during recrystallization melt on heating into "large" clusters of water whose redistribution and apparent equilibration is followed as a function of time and/or temperature by comparison with melting endotherms. We have also studied the effect of cooling rate on the melting pattern of ice with a methemoglobin sample containing 0.50 (g water)/(g protein), and we surmise that for this hydration cooling at rates of > or = approximately 150 K min-1 preserves on the whole the distribution of water molecules present at ambient temperature. PMID:7819504

  4. Spectrophotometric and Calorimetric Studies of Np(V) Complexation with Acetate at Variable Temperatures (T = 283 - 343 K)

    SciTech Connect

    Rao, Linfeng; Tian, Guoxin; Srinivasan, Thandankorai G.; Zanonato, PierLuigi; Di Bernardo, Plinio

    2009-12-21

    Spectrophotometric titrations were performed to identify the Np(V)/acetate complex and determine the equilibrium constants at variable temperatures (T = 283 - 343 K) and at the ionic strength of 1.05 mol {center_dot} kg{sup -1}. The enthalpy of complexation at corresponding temperatures was determined by microcalorimetric titrations. Results show that the complexation of Np(V) with acetate is weak but strengthened as the temperature is increased. The complexation is endothermic and is entropy-driven. The enhancement of the complexation at elevated temperatures is primarily due to the increasingly larger entropy gain when the solvent molecules are released from the highly-ordered solvation spheres of NpO{sub 2}{sup +} and acetate to the bulk solvent where the degree of disorder is higher at higher temperatures.

  5. SU-E-J-39: Comparison of PTV Margins Determined by In-Room Stereoscopic Image Guidance and by On-Board Cone Beam Computed Tomography Technique for Brain Radiotherapy Patients

    SciTech Connect

    Ganesh, T; Paul, S; Munshi, A; Sarkar, B; Krishnankutty, S; Sathya, J; George, S; Jassal, K; Roy, S; Mohanti, B

    2014-06-01

    Purpose: Stereoscopic in room kV image guidance is a faster tool in daily monitoring of patient positioning. Our centre, for the first time in the world, has integrated such a solution from BrainLAB (ExacTrac) with Elekta's volumetric cone beam computed tomography (XVI). Using van Herk's formula, we compared the planning target volume (PTV) margins calculated by both these systems for patients treated with brain radiotherapy. Methods: For a total of 24 patients who received partial or whole brain radiotherapy, verification images were acquired for 524 treatment sessions by XVI and for 334 sessions by ExacTrac out of the total 547 sessions. Systematic and random errors were calculated in cranio-caudal, lateral and antero-posterior directions for both techniques. PTV margins were then determined using van Herk formula. Results: In the cranio-caudal direction, systematic error, random error and the calculated PTV margin were found to be 0.13 cm, 0.12 cm and 0.41 cm with XVI and 0.14 cm, 0.13 cm and 0.44 cm with ExacTrac. The corresponding values in lateral direction were 0.13 cm 0.1 cm and 0.4 cm with XVI and 0.13 cm, 0.12 cm and 0.42 cm with ExacTrac imaging. The same parameters for antero-posterior were for 0.1 cm, 0.11 cm and 0.34 cm with XVI and 0.13 cm, 0.16 cm and 0.43 cm with ExacTrac imaging. The margins estimated with the two imaging modalities were comparable within ± 1 mm limit. Conclusion: Verification of setup errors in the major axes by two independent imaging systems showed the results are comparable and within ± 1 mm. This implies that planar imaging based ExacTrac can yield equal accuracy in setup error determination as the time consuming volumetric imaging which is considered as the gold standard. Accordingly PTV margins estimated by this faster imaging technique can be confidently used in clinical setup.

  6. Development of ac Calorimetric Method for Thermal Diffusivity Measurement I. Contribution of Thermocouple Attachment in a Thin Sample

    NASA Astrophysics Data System (ADS)

    Hatta, Ichiro; Kato, Ryozo; Maesono, Akikazu

    1986-06-01

    In a very thin sample, the contribution of addenda, thermocouple, glue etc., to the precise measurement is considered especially in two typical cases, in which the thermocouple is attached to the sample surface using glue. In the one case, glue is painted over the whole one-sided region starting from the thermocouple on the surface and in the other, a small amount of glue is used to fix the thermocouple at a particular point on the surface. Consistent with the theoretical consideration, it is experimentally verified in both cases that the addenda do not affect determination of the thermal diffusivity.

  7. Effects of methoxy and formyl substituents on the energetics and reactivity of α-naphthalenes: a calorimetric and computational study.

    PubMed

    Silva, Ana L R; Freitas, Vera L S; Ribeiro da Silva, Maria D M C

    2014-07-01

    A combined experimental and computational study was developed to evaluate and understand the energetics and reactivity of formyl and methoxy α-naphthalene derivatives. Static bomb combustion calorimetry and the Calvet microcalorimetry were the experimental techniques used to determine the standard (p(o)=0.1 MPa) molar enthalpies of formation, in the liquid phase, ΔfHm(o)(l), and of vaporization, Δl(g)Hm(o), at T=298.15K, respectively, of the two liquid naphthalene derivatives. Those experimental values were used to derive the values of the experimental standard molar enthalpies of formation, in the gaseous phase, ΔfHm(o)(g), of 1-methoxynaphthalene, (-3.0 ± 3.1)kJmol(-1), and of 1-formylnaphthalene, (36.3 ± 4.1)kJ mol(-1). High-level quantum chemical calculations at the composite G3(MP2)//B3LYP level were performed to estimate the values of the ΔfHm(o)(g) of the two compounds studied resulting in values in very good agreement with experimental ones. Natural bond orbital (NBO) calculations were also performed to determine more about the structure and reactivity of this class of compounds. PMID:24444416

  8. Thermodynamic, structural, and dynamic properties of supercooled water confined in mesoporous MCM-41 studied with calorimetric, neutron diffraction, and neutron spin echo measurements

    NASA Astrophysics Data System (ADS)

    Yoshida, Koji; Yamaguchi, Toshio; Kittaka, Shigeharu; Bellissent-Funel, Marie-Claire; Fouquet, Peter

    2008-08-01

    Thermodynamic, structural, and dynamic properties of heavy water (D2O) confined in mesoporous silica glass MCM-41 C10, C12, and C14 were investigated by differential scanning calorimetry, neutron diffraction, and neutron spin echo (NSE) measurements, respectively. The DSC data showed that no crystallization of D2O confined in C10 occurs in a temperature range between 298 and 180 K, and that crystalline ice is formed at 204 and 221 K for C12 and C14, respectively. For C10, the neutron radial distribution functions of confined D2O suggested a structural change in the supercooled state between 223 and 173 K. For C10 sample, it has been found that the tetrahedral-like water structure is partially enhanced in the central part of pores at 173 K. For all the samples, the intermediate scattering functions from the NSE measurements are fitted by the Kohlrausch-Williams-Watts stretched exponential function which implies that confined supercooled D2O exhibits a wide distribution of relaxation times. For C10, C12, and C14 samples, between 298 and 240 K, the relaxation times of supercooled D2O follow remarkably well the Vogel-Fulcher-Tamman equation; for C10 sample, below 240 K, the relaxation times of nonfreezing D2O show an Arrhenius type behavior. From the present experimental results on calorimetric, structural, and dynamic properties, it has been concluded that supercooled D2O confined in MCM-41 C10 experiences a transition from high-density to low-density hydrogen-bonded structure at around 229 K.

  9. Interaction of cationic dodecyl-trimethyl-ammonium bromide with oxy-HbGp by isothermal titration and differential scanning calorimetric studies: Effect of proximity of isoelectric point.

    PubMed

    Alves, Fernanda Rosa; Carvalho, Francisco Adriano O; Carvalho, José Wilson P; Tabak, Marcel

    2016-04-01

    In this work, isothermal titration and differential scanning calorimetric methods, in combination with pyrene fluorescence emission and dynamic light scattering have been used to investigate the interaction of dodecyltrimethylammonium bromide (DTAB) with the giant extracellular Glossoscolex paulistus hemoglobin (HbGp) in the oxy-form, at pH values around the isoelectric point (pI ≈ 5.5). Our ITC results have shown that the interaction of DTAB with the hemoglobin is more intense at pH 7.0, with a smaller cac (critical aggregation concentration) value. The increase of protein concentration does not influence the cac value of the interaction, at both pH values. Therefore, the beginning of the DTAB-oxy-HbGp premicellar aggregates formation, in the cac region, is not affected by the increase of protein concentration. HSDSC studies show higher Tm values at pH 5.0, in the absence and presence of DTAB, when compared with pH 7.0. Furthermore, at pH 7.0, an aggregation process is observed with DTAB in the range from 0.75 to 1.5 mmol/L, noticed by the exothermic peak, and similar to that observed for pure oxy-HbGp, at pH 5.0, and in the presence of DTAB. DLS melting curves show a decrease on the hemoglobin thermal stability for the oxy-HbGp-DTAB mixtures and formation of larger aggregates, at pH 7.0. Our present data, together with previous results, support the observation that the protein structural changes, at pH 7.0, occur at smaller DTAB concentrations, as compared with pH 5.0, due to the acidic pI of protein that favors the oxy-HbGp-cationic surfactant interaction at neutral pH. PMID:26574155

  10. Calorimetric study of the effect of bent-shaped dopant molecules on the critical behavior at the nematic-smectic-Ad phase transition

    NASA Astrophysics Data System (ADS)

    Sasaki, Y.; Ema, K.; Le, K. V.; Takezoe, H.; Dhara, S.; Sadashiva, B. K.

    2011-06-01

    We report results of calorimetric studies for the binary mixture of rodlike host n-alkyloxy-cyanobiphenyl (nOCB, n=8,9) and bent-shaped guest 1,3-phenylene-bis[4-(3-methylbenzoyloxy)]-4'-n-dodecylbiphenyl-4'-carboxylate (BC12). The effect of bent-shaped dopant molecules on the critical behavior associated with the nematic-smectic-Ad phase transition has been studied in detail. The transition temperature for the nematic-smectic-Ad phase sharply decreases as the increase of the mole fraction of the dopant concentration (denoted X for the BC12/9OCB mixture and Y for the BC12/8OCB mixture). The dependence of the critical exponent α on X and Y is well explained in terms of the McMillan ratio. A nearly tricritical exponent has been obtained for the X=0.01 mixture. X=0.02-0.03 mixtures, pure 8OCB, and Y=0.01-0.03 mixtures exhibit nonuniversal behaviors with effective exponents lying between the 3D-XY and tricritical exponents. The heat capacity anomaly for Y=0.05 has been well described with the 3D-XY exponent. The critical amplitude ratio A-/A+ is close to 1 and insensitive to the dopant concentration. No Fisher renormalization of the critical exponent has been observed even for nearly tricritical compositions, which indicates the smallness of the concentration plays a decisive role rather than the steepness of the N-SmAd phase boundary.

  11. Calorimetric analysis of thermodynamic stability and aggregation for apo and holo amyotrophic lateral sclerosis-associated Gly-93 mutants of superoxide dismutase.

    PubMed

    Stathopulos, Peter B; Rumfeldt, Jessica A O; Karbassi, Farhad; Siddall, Clare A; Lepock, James R; Meiering, Elizabeth M

    2006-03-10

    Differential scanning calorimetry was used to measure changes in thermodynamic stability and aggregation for glycine 93 mutants of human copper, zinc-superoxide dismutase (SOD). Glycine 93 is a conserved residue at position i + 3 of a tight turn and has been found to be a mutational hot spot in familial amyotrophic lateral sclerosis (fALS). The fALS-associated mutations, G93A, G93S, G93R, G93D, and G93V, were made in a pseudo wild-type background containing no free cysteines, which prevented the formation of aberrant disulfide bonds upon thermal unfolding, and enabled quantitative thermodynamic analysis of the effects of the mutations. Thermal unfolding was highly reversible for all the SODs in both the fully metallated (holo) and metal-free (apo) forms. The data for all the holo-SODs and for the apo-pseudo-wild-type SOD were well fit by a 2-state unfolding model for native dimer (N2) to two unfolded monomers (2U), N2 <--> 2U. The holo- and apo-forms of the mutants are significantly destabilized (by 1.5-3.5 kcal mol(-1) monomer) relative to the corresponding forms of pseudo wild-type, with the relative stabilities being correlated with statistical preferences for amino acids in this structural context. Although van't Hoff (DeltaHvH) to calorimetric (DeltaHcal) enthalpy ratios are close to unity for all the holo-SODs and for apo-pseudo-wild-type, consistent with a 2-state transition, DeltaHvH is considerably larger than DeltaHcal for all the apo-mutants. This suggests that the mutations cause apo-SOD to have an increased propensity to misfold or aggregate, which may be linked to increased toxic mutant SOD aggregation in fALS. PMID:16407238

  12. PREFACE: Sensors & their Applications XVI

    NASA Astrophysics Data System (ADS)

    Kyriacou, Panicos; O'Riordan, Alan

    2011-08-01

    This volume records the Proceedings of the sixteenth conference in the biennial Sensors and Their Applications series which took place at the Clarion Hotel, Cork, Ireland between 12-14 September 2011. The conference is organized by the Instrument Science and Technology Group of the Institute of Physics. On this occasion, the conference was hosted by Tyndall National Institute at University College Cork. This year the conference returns to Ireland, having last been held in Limerick in 2003. The conference proceedings record the continuing growth of the sensors community nationally and internationally. The conferences bring together contributions from scientists and engineers from academia, research institutes and industrial establishments, and therefore provide an excellent opportunity for these communities to present and discuss the latest results in the field of sensors, instrumentation and measurement. Amongst the more traditional themes, such as optical sensing, there is growth in new areas such as biomedical sensing and instrumentation, and nanosensing, which is reflected in this volume. Similarly the contribution of modelling and simulation techniques in sensor and instrumentation design and their applications is acknowledged by a session in this area. The sessions across the conference are supported by notable contributions from invited speakers. We would like to thank all of our colleagues in the sensor and instrumentation community who have supported this event by contributing manuscripts. Our thanks also go to Tyndall National Institute for hosting this conference and all the sponsors who, with their generous financial and in-kind contributions, enabled the better organization of this conference. We would also like to thank all the members of the Instrument Science and Technology Group for their support, and in particular for refereeing the submitted manuscripts. We are also pleased to express our thanks to the Conference Department of the Institute of Physics for their invaluable support in organising this event. We are especially grateful to Dawn Stewart for her responsive and efficient day-to-day handling of this event, as well as to Claire Garland for her planning and management of this event. We hope that the conference authors, participants and a wider audience will find these proceedings to be of interest and to serve as a useful reference text. Panicos KyriacouConference ChairmanAlan O'RiordanConference Local Chairman

  13. Simultaneous calorimetric and polarization microscopy investigations of light induced changes over phase transitions in a liquid crystal-napthopyran mixture

    NASA Astrophysics Data System (ADS)

    Paoloni, S.; Mercuri, F.; Marinelli, M.; Pizzoferrato, R.; Zammit, U.; Kosa, T.; Sukhomlinova, L.; Taheri, B.

    2015-10-01

    We have studied the specific heat and the thermal conductivity in a 4-(n-octyl)-4'-cyanobiphenyl liquid crystal (LC)-photochromic molecules mixture, before, during, and after the photo-activation of the dispersed photochromic molecules, over both the smectic A-nematic and the nematic-isotropic phase transitions. The evaluation of the specific heat has enabled the determination of the changes of the phase transition characteristics induced by the photochromic molecules photoisomerization, while that of the thermal conductivity could be used to monitor the modifications induced in the average LC molecular orientation. The polarization microscopy imaging of the sample texture constituted a valuable support for the interpretation of the obtained thermal conductivity results.

  14. Spectrophotometric and Calorimetric Studies of Np(V) Complexation with Sulfate at 10-70oC

    SciTech Connect

    Rao, Linfeng; Tian, Guoxin; Xia, Yuanxian; Friese, Judah I.

    2008-06-16

    Sulfate, one of the inorganic constituents in the groundwater of nuclear waste repository, could affect the migration of radioactive materials by forming complexes. Spectrophotometric and microcalorimetric titrations were performed to identify the Np(V)/sulfate complex and determine the equilibrium constants and enthalpy of complexation at 10-70 C. Results show that the complexation of Np(V) with sulfate is weak but slightly enhanced by the increase in temperature. The complexation is endothermic and becomes more endothermic with the increase in temperature. The enhanced complexation at elevated temperatures is due to the increasingly larger entropy of complexation that exceeds the increase in enthalpy, suggesting that the complexation of Np(V) with sulfate is entropy-driven.

  15. Synthesis and calorimetric, spectroscopic, and structural characterization of isocyanide complexes of trialkylaluminum and tri-tert-butylgallium.

    PubMed

    Kingsley, Nicholas B; Kirschbaum, Kristin; Teprovich, Joseph A; Flowers, Robert A; Mason, Mark R

    2012-02-20

    Addition of tert-butylisocyanide or 2,6-dimethylphenylisocyanide to a solution of trialkylaluminum or trialkylgallium results in formation of complexes R(3)M·C≡N(t)Bu (M = Al, R = Me (1), Et (2), (i)Bu (3), (t)Bu (4); M = Ga, R = (t)Bu (9)) or R(3)M·C≡N(2,6-Me(2)C(6)H(3)) (M = Al, R = Me (5), Et (6), (i)Bu (7), (t)Bu (8); M = Ga, R = (t)Bu (10)), respectively. Complexes 1, 4, 5, and 8-10 are isolated as solids, whereas the triethylaluminum and triisobutylaluminum adducts 2, 3, 6, and 7 are viscous oils. Complexes 1-10 were characterized by NMR ((1)H, (13)C) and IR spectroscopies, and the molecular structures of 4, 5, and 8-10 were also determined by X-ray crystallography. The frequency of the C≡N stretch of the isocyanide increased by 58-91 cm(-1) upon complexation, consistent with coordination of the isocyanide as a σ donor. Enthalpies of complex formation for 1-10 were determined by isothermal titration calorimetry. Enthalpy data suggest the following order of decreasing Lewis acidity: (t)Bu(3)Al ≫ (i)Bu(3)Al ≥ Me(3)Al ≈ Et(3)Al ≫ (t)Bu(3)Ga. In the absence of oxygen and protic reagents, the reported complexes do not undergo insertion or elimination reactions upon heating their benzene-d(6) solutions to 80 °C. PMID:22296217

  16. Isothermal Calorimetric Observations of the Affect of Welding on Compatibility of Stainless Steels with High-Test Hydrogen Peroxide Propellant

    NASA Technical Reports Server (NTRS)

    Gostowski, Rudy C.

    2002-01-01

    Compatibility is determined by the surface area, the chemical constituency and the surface finish of a material. In this investigation exposed area is obviously not a factor as the welded samples had a slightly smaller surface than the unwelded, but were more reactive. The chemical makeup of welded CRES 316L and welded CRES 304L have been observed in the literature to change from the parent material as chromium and iron are segregated in zones. In particular, the ratio of chromium to iron in CRES 316L increased from 0.260 to 0.79 in the heat affected zone (HAZ) of the weld and to 1.52 in the weld bead itself. In CRES 304L the ratio of chromium to iron increased from 0.280 to 0.44 in the HAZ and to 0.33 in the weld bead. It is possible that the increased reactivity of the welded samples and of those welded without purge gas is due to this segregation phenomenon. Likewise the reactivity increased in keeping with the greater roughness of the welded and welded without purge gas samples. Therefore enhanced roughness may also be responsible for the increased reactivity.

  17. Entropy-Driven Folding of an RNA Helical Junction: An Isothermal Titration Calorimetric Analysis of the Hammerhead Ribozyme†

    PubMed Central

    Mikulecky, Peter J.; Takach, Jennifer C.; Feig, Andrew L.

    2008-01-01

    Helical junctions are extremely common motifs in naturally occurring RNAs, but little is known about the thermodynamics that drive their folding. Studies of junction folding face several challenges: non-two-state folding behavior, superposition of secondary and tertiary structural energetics, and drastically opposing enthalpic and entropic contributions to folding. Here we describe a thermodynamic dissection of the folding of the hammerhead ribozyme, a three-way RNA helical junction, by using isothermal titration calorimetry of bimolecular RNA constructs. By using this method, we show that tertiary folding of the hammerhead core occurs with a highly unfavorable enthalpy change, and is therefore entropically driven. Furthermore, the enthalpies and heat capacities of core folding are the same whether supported by monovalent or divalent ions. These properties appear to be general to the core sequence of bimolecular hammerhead constructs. We present a model for the ion-induced folding of the hammerhead core that is similar to those advanced for the folding of much larger RNAs, involving ion-induced collapse to a structured, non-native state accompanied by rearrangement of core residues to produce the native fold. In agreement with previous enzymological and structural studies, our thermodynamic data suggest that the hammerhead structure is stabilized in vitro predominantly by diffusely bound ions. Our approach addresses several significant challenges that accompany the study of junction folding, and should prove useful in defining the thermodynamic determinants of stability in these important RNA motifs. PMID:15134461

  18. Entropy-driven folding of an RNA helical junction: an isothermal titration calorimetric analysis of the hammerhead ribozyme.

    PubMed

    Mikulecky, Peter J; Takach, Jennifer C; Feig, Andrew L

    2004-05-18

    Helical junctions are extremely common motifs in naturally occurring RNAs, but little is known about the thermodynamics that drive their folding. Studies of junction folding face several challenges: non-two-state folding behavior, superposition of secondary and tertiary structural energetics, and drastically opposing enthalpic and entropic contributions to folding. Here we describe a thermodynamic dissection of the folding of the hammerhead ribozyme, a three-way RNA helical junction, by using isothermal titration calorimetry of bimolecular RNA constructs. By using this method, we show that tertiary folding of the hammerhead core occurs with a highly unfavorable enthalpy change, and is therefore entropically driven. Furthermore, the enthalpies and heat capacities of core folding are the same whether supported by monovalent or divalent ions. These properties appear to be general to the core sequence of bimolecular hammerhead constructs. We present a model for the ion-induced folding of the hammerhead core that is similar to those advanced for the folding of much larger RNAs, involving ion-induced collapse to a structured, non-native state accompanied by rearrangement of core residues to produce the native fold. In agreement with previous enzymological and structural studies, our thermodynamic data suggest that the hammerhead structure is stabilized in vitro predominantly by diffusely bound ions. Our approach addresses several significant challenges that accompany the study of junction folding, and should prove useful in defining the thermodynamic determinants of stability in these important RNA motifs. PMID:15134461

  19. Spectrophotometric and Calorimetric Studies of U(VI) Complexation with Sulfate at 25-70oC

    SciTech Connect

    Tian, Guoxin; Rao, Linfeng

    2008-10-30

    Sulfate, one of the inorganic constituents in the groundwater of nuclear waste repository, could affect the migration of radioactive materials by forming complexes. Spectrophotometric and microcalorimetric titrations were performed to identify the U(VI)/sulfate complexes and determine the equilibrium constants and enthalpy of complexation at 25-70 C. Results show that U(VI) forms moderately strong complexes with sulfate, i.e., UO{sub 2}SO{sub 4}(aq) and UO{sub 2}(SO{sub 4}){sub 2}{sup 2-}, in this temperature range and the complexes become stronger as the temperature is increased: 2-fold and 10-fold increases in the stability constants of UO{sub 2}SO{sub 4}(aq) and UO{sub 2}(SO{sub 4}{sub 2}{sup 2-}), respectively, when the temperature is increased from 25 C to 70 C. The complexation is endothermic and entropy-driven, showing typical characteristics of inner-sphere complexation and 'hard acid'/'hard base' interactions. The thermodynamic trends are discussed in terms of dehydration of both the cation (UO{sub 2}{sup 2+}) and the anion (SO{sub 4}{sup 2-}) as well as the effect of temperature on the structure of water.

  20. A calorimetric study of energy conversion efficiency of a sonochemical reactor at 500 kHz for organic solvents.

    PubMed

    Toma, Maricela; Fukutomi, Satoshi; Asakura, Yoshiyuki; Koda, Shinobu

    2011-01-01

    It would seem that the economic viability is yet to be established for a great number of sonochemical processes, owning to their perfectible ultrasonic equipments. Industrial scale sonoreactors may become more important as a result of mastering the parameters with influence on their energy balance. This work related the solvent type to the energy efficiency as the first step of a complex study aiming to assess the energy balance of sonochemical reactors at 500 kHz. Quantitative measurements of ultrasonic power for water and 10 pure organic solvents were performed by calorimetry for a cylindrically shaped sonochemical reactor with a bottom mounted vibrating plate. It was found that the ultrasonic power is strongly related to the solvent, the energy conversion for organic liquids is half from that of water and there is a drop in energy efficiency for filling levels up to 250 mm organic solvents. Surface tension, viscosity and vapor pressure influence the energy conversion for organic solvents, but it is difficult explain these findings based on physical properties of solvents alone. The apparent intensity of the atomization process shows a good agreement with the experimentally determined values for energy conversion for water and the solvent group studied here. This study revealed that to attain the same ultrasonic power level, more electrical energy is need for organic solvents as compared to water. The energy balance equation has been defined based on these findings by considering an energy term for atomization. PMID:20655791

  1. Combined Spectroscopic and Calorimetric Studies to Reveal Absorption Mechanisms and Conformational Changes of Protein on Nanoporous Biomaterials

    PubMed Central

    Ahmadi, Saharnaz; Farokhi, Maryam; Padidar, Parisa; Falahati, Mojtaba

    2015-01-01

    In this study the effect of surface modification of mesoporous silica nanoparticles (MSNs) on its adsorption capacities and protein stability after immobilization of beta-lactoglobulin B (BLG-B) was investigated. For this purpose, non-functionalized (KIT-6) and aminopropyl-functionalized cubic Ia3d mesoporous silica ([n-PrNH2-KIT-6]) nanoparticles were used as nanoporous supports. Aminopropyl-functionalized mesoporous nanoparticles exhibited more potential candidates for BLG-B adsorption and minimum BLG leaching than non-functionalized nanoparticles. It was observed that the amount of adsorbed BLG is dependent on the initial BLG concentration for both KIT-6 and [n-PrNH2-KIT-6] mesoporous nanoparticles. Also larger amounts of BLG-B on KIT-6 was immobilized upon raising the temperature of the medium from 4 to 55 °C while such increase was undetectable in the case of immobilization of BLG-B on the [n-PrNH2-KIT-6]. At temperatures above 55 °C the amounts of adsorbed BLG on both studied nanomaterials decreased significantly. By Differential scanning calorimetry or DSC analysis the heterogeneity of the protein solution and increase in Tm may indicate that immobilization of BLG-B onto the modified KIT-6 results in higher thermal stability compared to unmodified one. The obtained results provide several crucial factors in determining the mechanism(s) of protein adsorption and stability on the nanostructured solid supports and the development of engineered nano-biomaterials for controlled drug-delivery systems and biomimetic interfaces for the immobilization of living cells. PMID:26230687

  2. 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.

  3. Steps Toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei XVI: A 13 Year Study of Spectral Variability in NGC 5548

    NASA Technical Reports Server (NTRS)

    Peterson, B. M.; Berlind, P.; Bertram, R.; Bischoff, K.; Bochkarev, N. G.; Burenkov, A. N.; Calkins, M.; Carrasco, L.; Chavushyan, V. H.

    2002-01-01

    We present the final installment of an intensive 13 year study of variations of the optical continuum and broad H beta emission line in the Seyfert 1 galaxy NGC 5548. The database consists of 1530 optical continuum measurements and 1248 H beta measurements. The H beta variations follow the continuum variations closely, with a typical time delay of about 20 days. However, a year-by-year analysis shows that the magnitude of emission-line time delay is correlated with the mean continuum flux. We argue that the data are consistent with the simple model prediction between the size of the broad-line region and the ionizing luminosity, r is proportional to L(sup 1/2)(sub ion). Moreover, the apparently linear nature of the correlation between the H beta response time and the nonstellar optical continuum F(sub opt) arises as a consequence of the changing shape of the continuum as it varies, specifically F(sub opt) is proportional to F(sup 0.56)(sub UV).

  4. Surfactant loss control in chemical flooding: Spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Quarterly technical progress report, January 1, 1993--March 31, 1993

    SciTech Connect

    Somasundaran, P.

    1993-05-01

    The aim of this project is to elucidate the mechanisms of adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effect of surfactant structure, surfactant combinations and other inorganic and polymeric species will be determined using solids of relevant mineralogy. A multi-pronged approach consisting of micro & nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability win be used to achieve the goals. The results of this study should help in controlling surfactant loss in chemical flooding and also in developing optimum structures and conditions for efficient chemical flooding processes. Adsorption of selected individual surfactants on oxide minerals was studied. The aim was to determine the effect of structure on surfactant adsorption at the solid-liquid as well as at the liquid-air interface. Nonionic polyethoxylated alkyl phenols and anionic meta xylene sulfonates (MXS) were the surfactants studied. Electrokinetic behavior was also determined along with adsorption in order to determine the role of electrostatic forces in determining the adsorption. In addition, the effect of varying the number of ethylene oxide groups on the adsorption of polyethoxylated alkyl phenols on silica was determined since the ethoxyl groups offer unique opportunities to control adsorption as well as wettability. Effect of pH was studied both because it is a parameter with first order effect and also because pH effects can help in developing mechanisms.

  5. Solution NMR and calorimetric analysis of Rem2 binding to the Ca2+ channel β4 subunit: a low affinity interaction is required for inhibition of Cav2.1 Ca2+ currents.

    PubMed

    Xu, Xingfu; Zhang, Fangxiong; Zamponi, Gerald W; Horne, William A

    2015-05-01

    Rem, Rad, Kir/Gem (RGK) proteins, including Rem2, mediate profound inhibition of high-voltage activated Ca(2+) channels containing intracellular regulatory β subunits. All RGK proteins bind to voltage-gated Ca(2+) channel β subunit (Cavβ) subunits in vitro, but the necessity of the interaction for current inhibition remains controversial. This study applies NMR and calorimetric techniques to map the binding site for Rem2 on human Cavβ4a and measure its binding affinity. Our experiments revealed 2 binding surfaces on the β4 guanylate kinase domain contributing to a 156 ± 18 µM Kd interaction: a hydrophobic pocket lined by 4 critical residues (L173, N261, H262, and V303), mutation of any of which completely disrupted binding, and a nearby surface containing 3 residues (D206, L209, and D258) that when individually mutated decreased affinity. Voltage-gated Ca(2+) channel α1A subunit (Cav2.1) Ca(2+) currents were completely inhibited by Rem2 when co-expressed with wild-type Cavβ4a, but were unaffected by Rem2 when coexpressed with a Cavβ4a site 1 (L173A/V303A) or site 2 (D258A) mutant. These results provide direct evidence for a low-affinity Rem2/Cavβ4 interaction and show definitively that the interaction is required for Cav2.1 inhibition. PMID:25563298

  6. First stars. XVI. HST/STIS abundances of heavy elements in the uranium-rich metal-poor star CS 31082-001

    NASA Astrophysics Data System (ADS)

    Siqueira Mello, C.; Spite, M.; Barbuy, B.; Spite, F.; Caffau, E.; Hill, V.; Wanajo, S.; Primas, F.; Plez, B.; Cayrel, R.; Andersen, J.; Nordström, B.; Sneden, C.; Beers, T. C.; Bonifacio, P.; François, P.; Molaro, P.

    2013-02-01

    Context. The origin and site(s) of the r-process nucleosynthesis is(are) still not known with certainty, but complete, detailed r-element abundances offer our best clues. The few extremely metal-poor (EMP) stars with large r-element excesses allow us to study the r-process signatures in great detail, with minimal interference from later stages of Galactic evolution. CS 31082-001 is an outstanding example of the information that can be gathered from these exceptional stars. Aims: Here we aim to complement our previous abundance determinations for third-peak r-process elements with new and improved results for elements of the first and second r-process peaks from near-UV HST/STIS and optical UVES spectra. These results should provide new insight into the nucleosynthesis of the elements beyond iron. Methods: The spectra were analyzed by a consistent approach based on an OSMARCS LTE model atmosphere and the Turbospectrum spectrum synthesis code to derive abundances of heavy elements in CS 31082-001, and using updated oscillator strengths from the recent literature. Synthetic spectra were computed for all lines of the elements of interest to check for proper line intensities and possible blends in these crowded spectra. Our new abundances were combined with the best previous results to provide reliable mean abundances for the first and second-peak r-process elements. Results: We present new abundances for 23 neutron-capture elements, 6 of which - Ge, Mo, Lu, Ta, W, and Re - have not been reported before. This makes CS 31082-001 the most completely studied r-II star, with abundances for a total of 37 neutron-capture elements. We also present the first NLTE+3D abundance of lead in this star, further constraining the nature of the r-process. Based on observations made with the NASA/ESA Hubble Space Telescope (HST) through the Space Telescope Science Institute, operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555; and

  7. State of water at 136 K determined by its relaxation time.

    PubMed

    Johari, G P

    2005-03-21

    Dielectric relaxation time of pure bulk water has been determined from the dielectric loss tangent scans against temperature at two frequencies. After calculating the frequency-independent background loss, the relaxation loss was obtained, and the relaxation time determined. The dielectric relaxation time of water is 35 +/- 13 s at 136 +/- 1 K, which is comparable with its structural relaxation time of ca. 33 s estimated from its T(g) endotherm (G. P. Johari, A. Hallbrucker and E. Mayer, Nature, 1987, 330, 552). Therefore, water is an ultraviscous liquid at 136 K, and this removes the basis for a comparison-based inference that water is a rigid glass up to a temperature of 165 K or higher (Y. Yue and C. A. Angell, Nature, 2004, 427, 717). The method yields satisfactory values for the relaxation time of stable glasses at their known calorimetric T(g). PMID:19791317

  8. Surfactant loss control in chemical flooding: Spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Quarterly technical progress report, April 1, 1993--June 30, 1993

    SciTech Connect

    Somasundaran, P.

    1993-08-31

    The aim of this contract is to elucidate the mechanisms underlying adsorption and surface precipitation of flooding surfactants on reservoir minerals. The results of this study should help in controlling surfactant loss in chemical flooding and also in developing optimum structures and conditions for efficient chemical flooding processes. Adsorption of single surfactants on silica and alumina as well as the solution behavior of surfactant mixtures was studied during this quarter. The adsorption of surfactants at the solid-liquid interface was correlated with changes in interfacial behavior such as wettability and zeta potential. Surface tension was used to study interactions between surfactant mixtures in solution. Mixed micellization of sodium dodecyl sulfate and dodecyl phenoxy polyethoxylated alcohol was found to be non-ideal. Regular solution theory adequately describes the interactions. The adsorption isotherm of a cationic surfactant, tetradecyl trimethyl ammonium chloride (TTAC), on alumina was determined at two values of pH. Changes in the settling rate of alumina suspensions after TTAC adsorption were also followed to describe the evolution of the adsorbed layer. At high surface coverage it was observed that the alumina surface became hydrophilic suggesting the formation of a TTAC bilayer at the surface. Wettability of silica after adsorption of nonyl phenyl polyethoxylated alcohols (with number of polyethylene oxide groups varying from 10-40) was measured using flotation to determine the orientation of the adsorbed layer. Effect of number of ethylene oxide groups was also determined. The amount of silica floated after the nonionic surfactant adsorption was same irrespective of the ethylene oxide chain length.

  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. Numerical Modeling and Experimental Validation by Calorimetric Detection of Energetic Materials Using Thermal Bimorph Microcantilever Array: A Case Study on Sensing Vapors of Volatile Organic Compounds (VOCs).

    PubMed

    Kang, Seok-Won; Fragala, Joe; Banerjee, Debjyoti

    2015-01-01

    Bi-layer (Au-Si₃N₄) microcantilevers fabricated in an array were used to detect vapors of energetic materials such as explosives under ambient conditions. The changes in the bending response of each thermal bimorph (i.e., microcantilever) with changes in actuation currents were experimentally monitored by measuring the angle of the reflected ray from a laser source used to illuminate the gold nanocoating on the surface of silicon nitride microcantilevers in the absence and presence of a designated combustible species. Experiments were performed to determine the signature response of this nano-calorimeter platform for each explosive material considered for this study. Numerical modeling was performed to predict the bending response of the microcantilevers for various explosive materials, species concentrations, and actuation currents. The experimental validation of the numerical predictions demonstrated that in the presence of different explosive or combustible materials, the microcantilevers exhibited unique trends in their bending responses with increasing values of the actuation current. PMID:26334276

  11. Role of an invariant lysine residue in folate binding on Escherichia coli thymidylate synthase: calorimetric and crystallographic analysis of the K48Q mutant

    PubMed Central

    Arvizu-Flores, Aldo A.; Sugich-Miranda, Rocio; Arreola, Rodrigo; Garcia-Orozco, Karina D.; Velazquez-Contreras, Enrique F.; Montfort, William R.; Maley, Frank; Sotelo-Mundo, Rogerio R.

    2008-01-01

    Thymidylate synthase (TS) catalyzes the reductive methylation of deoxyuridine monophosphate (dUMP) using methylene tetrahydrofolate (CH2THF) as cofactor, the glutamate tail of which forms a water-mediated hydrogen-bond with an invariant lysine residue of this enzyme. To understand the role of this interaction, we studied the K48Q mutant of Escherichia coli TS using structural and biophysical methods. The kcat of the K48Q mutant was 430 fold lower than wild-type TS in activity, while the the Km for the (R)-stereoisomer of CH2THF was 300 µM, about 30 fold larger than Km from the wild-type TS. Affinity constants were determined using isothermal titration calorimetry, which showed that binding was reduced by one order of magnitude for folate-like TS inhibitors, such as propargyl-dideaza folate (PDDF) or compounds that distort the TS active site like BW1843U89 (U89). The crystal structure of the K48Q-dUMP complex revealed that dUMP binding is not impaired in the mutamt, and that U89 in a ternary complex of K48Q-nucleotide-U89 was bound in the active site with subtle differences relative to comparable wild type complexes. PDDF failed to form ternary complexes with K48Q and dUMP. Thermodynamic data correlated with the structural determinations, since PDDF binding was dominated by enthalpic effects while U89 had an important entropic component. In conclusion, K48 is critical for catalysis since it leads to a productive CH2THF binding, while mutation at this residue does not affect much the binding of inhibitors that do not make contact with this group. PMID:18403248

  12. Scientific basis for nuclear waste management XVI

    SciTech Connect

    Interrante, C.G.; Pabalan, R.T.

    1993-12-31

    One most significant aspect of this particular symposium is the focus on the scientific basis for management of nuclear waste. Engineering principles and practices are important, but this symposium focuses on the science. The extension and application of engineering ``know how`` to waste management problems sometimes requires a degree of understanding not normally needed to solve other engineering problems. In materials science, for example, scientific understandings important to long-term behavior may be obtained from (1) characterizations and analyses of the structure and properties of materials, (2) the recognition of advancements needed to ensure performance, and (3) improvements in methods of fabrication and processing. In addition to the materials science topics addressed here (on waste forms, engineered barrier systems, and the near-field environment), the symposium addressed various far-field topics. The proceedings are divided into the following sections: spent fuel; glass and crystalline waste forms; glass performance--mechanisms and models; cementitious materials; container alteration; microbiologically influenced corrosion; near-field interactions; natural analogues; long-term prediction for engineered barriers; performance assessment of engineered barrier systems; radionuclide chemistry and transport; and performance assessment of geological systems. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  13. Effect of temperature on the protonation of N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid in aqueous solutions: Potentiometric and calorimetric studies

    SciTech Connect

    Li, Xingliang; Zhang, Zhicheng; Endrizzi, Francesco; Martin, Leigh R.; Luo, Shunzhong; Rao, Linfeng

    2015-06-01

    The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Komplexes) has been demonstrated in several pilot-scale operations to be effective at separating trivalent actinides (An3+) from trivalent lanthanides (Ln3+). However, fundamental studies have revealed undesired aspects of TALSPEAK, such as the significant partitioning of Na+, lactic acid, and water into the organic phase, thermodynamically unpredictable pH dependence, and the slow extraction kinetics. In the modified TALSPEAK process, the combination of the aqueous holdback complexant HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid) with the extractant HEH[EHP] (2-ethyl(hexyl) phosphonic acid mono-2-ethylhexyl ester) in the organic phase has been found to exhibit a nearly flat pH dependence between 2.5 and 4.5 and more rapid phase transfer kinetics for the heavier lanthanides. To help understand the speciation of Ln3+ and An3+ in the modified TALSPEAK, systematic studies are underway on the thermodynamics of major reactions in the HEDTA system under conditions relevant to the process (e.g., higher temperatures). Thermodynamics of the protonation and complexation of HEDTA with Ln3+ were studied at variable temperatures. Equilibrium constants and enthalpies were determined by a combination of techniques including potentiometry and calorimetry. This paper presents the protonation constants of HEDTA at T = (25 to 70) °C. The potentiometric titrations have demonstrated that, stepwise, the first two protonation constants decrease and the third one slightly increases with the increase of temperature. This trend is in good agreement with the enthalpy of protonation directly determined by calorimetry. The results of NMR analysis further confirm that the first two protonation reactions occur on the diamine nitrogen atoms, while the third protonation reaction occurs on the oxygen of a

  14. Numerical Modeling and Experimental Validation by Calorimetric Detection of Energetic Materials Using Thermal Bimorph Microcantilever Array: A Case Study on Sensing Vapors of Volatile Organic Compounds (VOCs)

    PubMed Central

    Kang, Seok-Won; Fragala, Joe; Banerjee, Debjyoti

    2015-01-01

    Bi-layer (Au-Si3N4) microcantilevers fabricated in an array were used to detect vapors of energetic materials such as explosives under ambient conditions. The changes in the bending response of each thermal bimorph (i.e., microcantilever) with changes in actuation currents were experimentally monitored by measuring the angle of the reflected ray from a laser source used to illuminate the gold nanocoating on the surface of silicon nitride microcantilevers in the absence and presence of a designated combustible species. Experiments were performed to determine the signature response of this nano-calorimeter platform for each explosive material considered for this study. Numerical modeling was performed to predict the bending response of the microcantilevers for various explosive materials, species concentrations, and actuation currents. The experimental validation of the numerical predictions demonstrated that in the presence of different explosive or combustible materials, the microcantilevers exhibited unique trends in their bending responses with increasing values of the actuation current. PMID:26334276

  15. Surfactant loss control in chemical flooding: Spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1992--September 30, 1993

    SciTech Connect

    Somasundaran, P.

    1994-07-01

    The aim of this research project is to investigate mechanisms underlying adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effects of surfactant structure, surfactant combinations, various inorganic and polymeric species, and solids mineralogy will be determined. A multi-pronged approach consisting of micro & nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability; is used in this study. The results obtained should help in controlling surfactant loss in chemical flooding and in developing optimum structures and conditions for efficient chemical flooding processes. During the first year of this three year contract, adsorption of single surfactants and select surfactant mixtures was studied at the solid-liquid and gas-liquid interfaces. Surfactants studied include alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride. Adsorption of surfactant mixtures of varying composition was also investigated. The microstructure of the adsorbed layer was characterized using fluorescence spectroscopy. Changes interfacial properties such as wettability, electrokinetics and stability of reservoir minerals were correlated with the amount of reagent adsorbed. Strong effects of the structure of the surfactant and position of functional groups were revealed.

  16. Structural and calorimetric studies demonstrate that the hepatocyte nuclear factor 1β (HNF1β) transcription factor is imported into the nucleus via a monopartite NLS sequence.

    PubMed

    Wiedmann, Mareike M; Aibara, Shintaro; Spring, David R; Stewart, Murray; Brenton, James D

    2016-09-01

    The transcription factor hepatocyte nuclear factor 1β (HNF1β) is ubiquitously overexpressed in ovarian clear cell carcinoma (CCC) and is a potential therapeutic target. To explore potential approaches that block HNF1β transcription we have identified and characterised extensively the nuclear localisation signal (NLS) for HNF1β and its interactions with the nuclear protein import receptor, Importin-α. Pull-down assays demonstrated that the DNA binding domain of HNF1β interacted with a spectrum of Importin-α isoforms and deletion constructs tagged with eGFP confirmed that the HNF1β (229)KKMRRNR(235) sequence was essential for nuclear localisation. We further characterised the interaction between the NLS and Importin-α using complementary biophysical techniques and have determined the 2.4Å resolution crystal structure of the HNF1β NLS peptide bound to Importin-α. The functional, biochemical, and structural characterisation of the nuclear localisation signal present on HNF1β and its interaction with the nuclear import protein Importin-α provide the basis for the development of compounds targeting transcription factor HNF1β via its nuclear import pathway. PMID:27346421

  17. Surfactant loss control in chemical flooding spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Annual report, September 30, 1992--September 30 1995

    SciTech Connect

    Casteel, J.

    1996-07-01

    The aim of this research project was to investigate mechanisms governing adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effects of surfactant structure, surfactant combinations, various inorganic and polymeric species, and solids mineralogy have been determined. A multi-pronged approach consisting of micro & nano spectroscopy, electrokinetics, surface tension and wettability is used in this study. The results obtained should help in controlling surfactant loss in chemical flooding and in developing optimum structures and conditions for efficient chemical flooding processes. During the three years contract period, adsorption of single surfactants and select surfactant mixtures was studied at the solid-liquid and gas-liquid interfaces. Alkyl xylene sulfonates, polyethoxylated alkyl phenols, octaethylene glycol mono n-decyl ether, and tetradecyl trimethyl ammonium chloride were the surfactants studied. Adsorption of surfactant mixtures of varying composition was also investigated. The microstructure of the adsorbed layer was characterized using fluorescence spectroscopy. Changes in interfacial properties such as wettability, electrokinetics and stability of reservoir minerals were correlated with the amounts of reagent adsorbed. Strong effects of the structure of the surfactant and position of functional groups were revealed. Changes of microstructure upon dilution (desorption) were also studied. Presence of the nonionic surfactants in mixed aggregate leads to shielding of the charge of ionic surfactants which in turn promotes aggregation but reduced electrostatic attraction between the charged surfactant and the mineral surface. Strong consequences of surfactant interactions in solution on adsorption as well as correlations between monomer concentration in mixtures and adsorption were revealed.

  18. Structural and Calorimetric Studies Demonstrate that Xeroderma Pigmentosum Type G (XPG) Can Be Imported to the Nucleus by a Classical Nuclear Import Pathway via a Monopartite NLS Sequence.

    PubMed

    Barros, Andrea C de; Takeda, Agnes A S; Dreyer, Thiago R; Velazquez-Campoy, Adrian; Kobe, Bostjan; Fontes, Marcos R M

    2016-05-22

    Xeroderma pigmentosum type G (XPG) proteins are involved in DNA lesion recognition and promotion of nucleotide excision repair. Specific mutations in these proteins may lead to Cockayne syndrome, in which the patients may display severe developmental retardation and neurological abnormalities. No structural information is available for their spacer region or the C-terminal domain, which are important, respectively, for specific nucleotide excision repair activity and substrate specificity, as well as nuclear translocation. Immunofluorescence studies suggested two specific regions of the XPG C-terminus as potential bipartite nuclear localization sequences, which would be responsible for its translocation to the nucleus by the classical nuclear import pathway mediated by the importin-α (Impα). Thus, in order to test these hypotheses and gain insight into the structural basis for the nuclear import process for the XPG protein, we solved the crystal structures of complexes formed by the Impα and peptides corresponding to both putative nuclear localization signal (NLS) sequences (XPG1 and XPG2) and performed isothermal titration calorimetry assays to determine their binding affinities. Structural experiments confirm the binding of both NLS peptides to Impα but, unexpectedly, they bind to the receptor as monopartite NLSs. The isothermal titration calorimetry assays demonstrated that XPG1 and XPG2 peptides bind to two separate binding sites, but with high affinity to the major NLS-binding site of the Impα, resembling classical monopartite SV40 TAg NLS. The results lead to insights about what distinguishes monopartite and bipartite NLSs, as well as the differential roles of XPG1 and XPG2 NLSs in the nuclear localization of XPG. PMID:26812207

  19. Crystallization of glassy metal surfaces in Mg Zn alloy determined by resonant photoacoustic detection

    NASA Astrophysics Data System (ADS)

    Martínez, O. E.; Crossa Archiopoli, U.; Cesa, Y.; Mingolo, N.

    2005-12-01

    Amorphous layers in a Mg-based alloy are studied by a resonant photoacoustic technique. The technique is shown to provide information on the crystallization temperature of a thin amorphous layer when the sample is heated. This determination provides crucial information regarding thermal stability of the treated surface, not accessible by standard calorimetric techniques. The layer analyzed is tens of micrometers thick, produced by rapid melting by a pulsed electron gun and subsequent rapid cooling towards the substrate. It is shown that the signal from the photoacoustic detection arises mainly from the volume change during crystallization at about 390 K. The volume change due to the structural relaxation of the glass before crystallization is also detected.

  20. Determination of plutonium isotopic composition by gamma-ray spectroscopy

    SciTech Connect

    Sampson, T.E.; Hsue, S.T.; Parker, J.L.; Johnson, S.S.; Bowersox, D.F.

    1981-01-01

    We discuss the general approach, computerized data analysis methods, and results of measurements used to determine the isotopic composition of plutonium by gamma-ray spectroscopy. The simple techniques are designed to be applicable to samples of arbitrary size, geometry, age, chemical, and isotopic composition. The combination of the gamma spectroscopic measurement of isotopic composition coupled with calorimetric measurement of total sample power is shown to give a totally nondestructive determination of sample plutonium mass with a precision of 0.6% for 1000-g samples of PuO/sub 2/ with 12% /sup 240/Pu content. The precision of isotopic measurements depends upon many factors, including sample size, sample geometry, and isotopic content. Typical ranges are found to be /sup 238/Pu, 1 to 10%; /sup 239/Pu, 0.1 to 0.5%; /sup 240/Pu, 2 to 5%; /sup 241/Pu, 0.3 to 0.7%; /sup 242/Pu (determined by isotopic correlation); and /sup 241/Am, 0.2 to 10%.

  1. Thermodynamics of native protein/foreign surface interactions. IV. Calorimetric and microelectrophoretic study of human fibrinogen sorption onto glass and LTI-carbon.

    PubMed

    Chiu, T H; Nyilas, E; Lederman, D M

    1976-01-01

    isotherms of fibrinogen obtained for both the glass and LTI-carbon powder adsorbents are not amenable to Langmuir type analysis but indicate multilayer sorption with a possible change in binding mechanism after the completion of the first sorbed monolayer. The adsorptivities attained at first monolayer coverage were slightly greater on glass (approximately 0.76 mug/cm2) than on LTI-carbon (approximately 0.52 mug/cm2). 4. Using a custom-built, thermistorized, isothermal-jacketed microcalorimeter routinely capable of resolving temperature changes of 0.00001 degrees C in 100 ml of aqueous sample volume, the "intensity" of interaction between fibrinogen and each of the microparticulate adsorbents was studied by the direct measurement of the net overall enthalpy changes, hI(SLP)25 arising as a result of protein adsorption. From these values, the net heat of protein sorption has been determined... PMID:951870

  2. Nanobridge SQUIDs as calorimetric inductive particle detectors

    NASA Astrophysics Data System (ADS)

    Gallop, John; Cox, David; Hao, Ling

    2015-08-01

    Superconducting transition edge sensors (TESs) have made dramatic progress since their invention some 65 years ago (Andrews et al 1949 Phys. Rev. 76 154-155 Irwin and Hilton 2005 Topics Appl. Phys. 99 63-149) until now there are major imaging arrays of TESs with as many as 7588 separate sensors. These are extensively used by astronomers for some ground-breaking observations (Hattori et al 2013 Nucl. Instrum. Methods Phys. Res. A 732 299-302). The great success of TES systems has tended to overshadow other superconducting sensor developments. However there are other types (Sobolewski et al 2003 IEEE Trans. Appl. Supercond. 13 1151-7 Hadfield 2009 Nat. Photonics 3 696-705) which are discussed in papers within this special edition of the journal. Here we describe a quite different type of detector, also applicable to single photon detection but possessing possible advantages (higher sensitivity, higher operating temperature) over the conventional TES, at least for single detectors.

  3. 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.

  4. Use of flow calorimetry for determining enthalpies of absorption and the solubility of CO{sub 2} in aqueous monoethanolamine solutions

    SciTech Connect

    Mathonat, C.; Majer, V.; Grolier, J.P.E.

    1998-10-01

    A flow mixing unit adapted to a Setaram C-80 calorimeter was used for measuring enthalpies of absorption of carbon dioxide in a 30 wt% aqueous solution of monoethanolamine (MEA) at three temperatures (313.15, 353.15, and 393.15 K) and three pressures (2.0, 5.0, and 10.0 MPa). Determinations were performed both in the region where the gas is fully absorbed in the solvent and also in the region of concentrations above the saturation. Experimental data served to obtain the integral enthalpies of absorption and for indirect determination of solubility limits. Where comparison was possible, the presented results derived from calorimetric determinations were in reasonable agreement with those obtained from phase equilibria measurements.

  5. 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

  6. Stochastic determination of matrix determinants.

    PubMed

    Dorn, Sebastian; Ensslin, Torsten A

    2015-07-01

    Matrix determinants play an important role in data analysis, in particular when Gaussian processes are involved. Due to currently exploding data volumes, linear operations-matrices-acting on the data are often not accessible directly but are only represented indirectly in form of a computer routine. Such a routine implements the transformation a data vector undergoes under matrix multiplication. While efficient probing routines to estimate a matrix's diagonal or trace, based solely on such computationally affordable matrix-vector multiplications, are well known and frequently used in signal inference, there is no stochastic estimate for its determinant. We introduce a probing method for the logarithm of a determinant of a linear operator. Our method rests upon a reformulation of the log-determinant by an integral representation and the transformation of the involved terms into stochastic expressions. This stochastic determinant determination enables large-size applications in Bayesian inference, in particular evidence calculations, model comparison, and posterior determination. PMID:26274302

  7. Stochastic determination of matrix determinants

    NASA Astrophysics Data System (ADS)

    Dorn, Sebastian; Enßlin, Torsten A.

    2015-07-01

    Matrix determinants play an important role in data analysis, in particular when Gaussian processes are involved. Due to currently exploding data volumes, linear operations—matrices—acting on the data are often not accessible directly but are only represented indirectly in form of a computer routine. Such a routine implements the transformation a data vector undergoes under matrix multiplication. While efficient probing routines to estimate a matrix's diagonal or trace, based solely on such computationally affordable matrix-vector multiplications, are well known and frequently used in signal inference, there is no stochastic estimate for its determinant. We introduce a probing method for the logarithm of a determinant of a linear operator. Our method rests upon a reformulation of the log-determinant by an integral representation and the transformation of the involved terms into stochastic expressions. This stochastic determinant determination enables large-size applications in Bayesian inference, in particular evidence calculations, model comparison, and posterior determination.

  8. An oxygen flow calorimeter for determining the heating value of kilogram size samples of municipal solid waste

    NASA Astrophysics Data System (ADS)

    Domalski, E. S.; Churney, K. L.; Ledford, A. E.; Ryan, R. V.; Reilly, M. L.

    1982-02-01

    A calorimeter to determine the enthalpies of combustion of kilogram size samples of minimally processed municipal solid municipal waste (MSW) in flowing oxygen near atmospheric pressure is discussed. The organic fraction of 25 gram pellets of highly processed MSW was burned in pure oxygen to CO2 and H2O in a small prototype calorimeter. The carbon content of the ash and the uncertainty in the amount of CO in the combustion products contribute calorimetric errors of 0.1 percent or less to the enthalpy of combustion. Large pellets of relatively unprocessed MSW have been successfully burned in a prototype kilogram size combustor at a rate of 15 minutes per kilogram with CO/CO2 ratios not greater than 0.1 percent. The design of the kilogram size calorimeter was completed and construction was begun.

  9. Physicochemical determinants in the cellular responses to nanostructured amorphous silicas.

    PubMed

    Gazzano, Elena; Ghiazza, Mara; Polimeni, Manuela; Bolis, Vera; Fenoglio, Ivana; Attanasio, Angelo; Mazzucco, Gianna; Fubini, Bice; Ghigo, Dario

    2012-07-01

    Amorphous silicas, opposite to crystalline polymorphs, have been regarded so far as nonpathogenic, but few studies have addressed the toxicity of the wide array of amorphous silica forms. With the advent of nanotoxicology, there has been a rising concern about the safety of silica nanoparticles to be used in nanomedicine. Here, we report a study on the toxicity of amorphous nanostructured silicas obtained with two different preparation procedures (pyrolysis vs. precipitation), the pyrogenic in two very different particle sizes, in order to assess the role of size and origin on surface properties and on the cell damage, oxidative stress, and inflammatory response elicited in murine alveolar macrophages. A quartz dust was employed as positive control and monodispersed silica spheres as negative control. Pyrogenic silicas were remarkably more active than the precipitated one as to cytotoxicity, reactive oxygen species production, lipid peroxidation, nitric oxide synthesis, and production of tumor necrosis factor-α, when compared both per mass and per unit surface. Between the two pyrogenic silicas, the larger one was the more active. Silanols density is the major difference in surface composition among the three silicas, being much larger than the precipitated one as indicated by joint calorimetric and infrared spectroscopy analysis. We assume here that full hydroxylation of a silica surface, with consequent stable coverage by water molecules, reduces/inhibits toxic behavior. The preparation route appears thus determinant in yielding potentially toxic materials, although the smallest size does not always correspond to an increased toxicity. PMID:22491428

  10. Virulence Determination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter reviews the in vitro and in vivo assays that are available for determination of pathogenic potential of Listeria monocytogenes bacteria, highlighting the value of using multiplex PCR for rapid and accurate assessment of listerial virulence....

  11. Climate determinism or Geomagnetic determinism?

    NASA Astrophysics Data System (ADS)

    Gallet, Y.; Genevey, A.; Le Goff, M.; Fluteau, F.; Courtillot, V.

    2006-12-01

    A number of episodes of sharp geomagnetic field variations (in both intensity and direction), lasting on the order of a century, have been identified in archeomagnetic records from Western Eurasia and have been called "archeomagnetic jerks". These seem to correlate well with multi-decadal cooling episodes detected in the North Atlantic Ocean and Western Europe, suggesting a causal link between both phenomena. A possible mechanism could be a geomagnetic modulation of the cosmic ray flux that would control the nucleation rate of clouds. We wish to underline the remarkable coincidence between archeomagnetic jerks, cooling events in Western Europe and drought periods in tropical and sub-tropical regions of the northern hemisphere. The latter two can be interpreted in terms of global teleconnections among regional climates. It has been suggested that these climatic variations had caused major changes in the history of ancient civilizations, such as in Mesopotamia, which were critically dependent on water supply and particularly vulnerable to lower rainfall amounts. This is one of the foundations of "climate determinism". Our studies, which suggest a geomagnetic origin for at least some of the inferred climatic events, lead us to propose the idea of a "geomagnetic determinism" in the history of humanity.

  12. Determination of ideal-gas enthalpies of formation for key compounds:

    SciTech Connect

    Steele, W.V.; Chirico, R.D.; Nguyen, A.; Hossenlopp, I.A.; Smith, N.K.

    1991-10-01

    The results of a study aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic and organosilicon substances are reported. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase, vapor-pressure measurements, and differential scanning calorimetric (d.s.c.) heat-capacity measurements. Ideal-gas enthalpies of formation of ({plus minus})-butan-2-ol, tetradecan-1-ol, hexan-1,6-diol, methacrylamide, benzoyl formic acid, naphthalene-2,6-dicarboxylic acid dimethyl ester, and tetraethylsilane are reported. A crystalline-phase enthalpy of formation at 298.15 K was determined for naphthalene-2,6-dicarboxylic acid, which decomposed at 695 K before melting. The combustion calorimetry of tetraethylsilane used the proven fluorine-additivity methodology. Critical temperature and critical density were determined for tetraethylsilane with differential scanning calorimeter and the critical pressure was derived. Group-additivity parameters useful in the application of group- contribution correlations are derived. 112 refs., 13 figs., 19 tabs.

  13. Determination of ideal-gas enthalpies of formation for key compounds: The 1989 project results

    NASA Astrophysics Data System (ADS)

    Steele, W. V.; Chirico, R. D.; Nguyen, A.; Hossenlopp, I. A.; Smith, N. K.

    1991-10-01

    The results of a study aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic and organosilicon substances are reported. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase, vapor pressure measurements, and differential scanning calorimetric (dsc) heat capacity measurements. Ideal gas enthalpies of formation of (+ or -) butan-2-ol, tetradecan-1-ol, hexan-1,6-diol, methacrylamide, benzoyl formic acid, naphthalene 2,6-dicarboxylic acid dimethyl ester, and tetraethylsilane are reported. A crystalline-phase enthalpy of formation at 298.15 K was determined for naphthalene-2,6-dicarboxylic acid, which decomposed at 695 K before melting. The combustion calorimetry of tetraethylsilane used the proven fluorine-additivity methodology. Critical temperature and critical density were determined for tetraethylsilane with differential scanning calorimeter and the critical pressure was derived. Group additivity parameters useful in the application of group contribution correlations are derived.

  14. Thermal and Physical Property Determinations for Ionsiv IE-911 Crystalline Silicotitanate and Savannah River Site Waste Simulant Solutions

    SciTech Connect

    Bostick, D.T.; Steele, W.V.

    1999-08-01

    This document describes physical and thermophysical property determinations that were made in order to resolve questions associated with the decontamination of Savannah River Site (SRS) waste streams using ion exchange on crystalline silicotitanate (CST). The research will aid in the understanding of potential issues associated with cooling of feed streams within SRS waste treatment processes. Toward this end, the thermophysical properties of engineered CST, manufactured under the trade name, Ionsive{reg_sign} IE-911 by UOP, Mobile, AL, were determined. The heating profiles of CST samples from several manufacturers' production runs were observed using differential scanning calorimetric (DSC) measurements. DSC data were obtained over the region of 10 to 215 C to check for the possibility of a phase transition or any other enthalpic event in that temperature region. Finally, the heat capacity, thermal conductivity, density, viscosity, and salting-out point were determined for SRS waste simulants designated as Average, High NO{sub 3}{sup {minus}} and High OH{sup {minus}} simulants.

  15. Determination of test methods for the prediction of the behavior of mass concrete

    NASA Astrophysics Data System (ADS)

    Ferraro, Christopher C.

    Hydration at early ages results from chemical and physical processes that take place between Portland cement and water, and is an exothermic process. The resultant heat evolution and temperature rise for massive concrete placements can be so great that the temperature differentials between the internal concrete core and outer concrete stratum can cause cracking due to thermal gradients. Accurate prediction of temperature distribution and stresses in mass concrete is needed to determine if a given concrete mixture design may have problems in the field, so that adjustments to the design can be made prior to its use. This research examines calorimetric, strength, and physical testing methods in an effort to predict the thermal and physical behavior of mass concrete. Four groups of concrete mixture types containing different cementitious materials are examined. One group contains Portland cement, while the other three groups incorporate large replacements of supplementary cementitious materials: granulated blast furnace slag, fly ash, and a ternary blend (combining Portland cement, fly ash, and slag).

  16. Determination of the relaxation characteristics of sugar glasses embedded in microfiber substrates

    PubMed Central

    Weng, Lindong; Elliott, Gloria D.

    2014-01-01

    Recently there has been considerable interest in developing sugar glasses that enable storage of biologics without refrigeration. Microfiber filter papers are good substrates for drying biologics in the presence of sugar glass-formers, providing for an even distribution of samples and an enhanced surface area for drying, but the opaqueness prevents macroscopic observation of the sample and can introduce complexities that impede physical characterization. Because drying kinetics and processing conditions can impact the relaxation dynamics (e.g., α- and β-relaxation), which can influence the efficacy of the glass as a stabilizer, methods are needed that can enable a determination of relaxation phenomena of sugar glasses in such complex environments. In this study we present a method which provides verification of the absence of crystallinity following drying on glass fiber filter paper and also enables the determination of relaxation characteristics of amorphous sugar compositions embedded within these filter substrates. Using material pockets to contain the sugar glass-embedded microfiber paper, the α-relaxation temperature, Tα, was determined as a function of the water content in trehalose and sucrose samples using Dynamic Mechanical Analysis (DMA). Results were verified by comparison with previous calorimetric and spectroscopic studies. The data also demonstrated the plasticizing effects of water, as Tα was shown to correlate with water content via a Gordon-Taylor-like relationship. Our findings validate a new approach for determining the relaxation characteristics of microfiber embedded sugar glasses, and offer new insights into the relaxation characteristics of glasses prepared by microwave-assisted drying on filter papers. PMID:25280724

  17. Determination of the relaxation characteristics of sugar glasses embedded in microfiber substrates.

    PubMed

    Weng, Lindong; Elliott, Gloria D

    2014-11-01

    Recently there has been considerable interest in developing sugar glasses that enable storage of biologics without refrigeration. Microfiber filter papers are good substrates for drying biologics in the presence of sugar glass-formers, providing for an even distribution of samples and an enhanced surface area for drying, but the opaqueness prevents macroscopic observation of the sample and can introduce complexities that impede physical characterization. Because drying kinetics and processing conditions can impact the relaxation dynamics (e.g., α- and β-relaxation), which can influence the efficacy of the glass as a stabilizer, methods are needed that can enable a determination of relaxation phenomena of sugar glasses in such complex environments. In this study we present a method which provides verification of the absence of crystallinity following drying on glass fiber filter paper and also enables the determination of relaxation characteristics of amorphous sugar compositions embedded within these filter substrates. Using material pockets to contain the sugar glass-embedded microfiber paper, the α-relaxation temperature, Tα, was determined as a function of the water content in trehalose and sucrose samples using Dynamic Mechanical Analysis (DMA). Results were verified by comparison with previous calorimetric and spectroscopic studies. The data also demonstrated the plasticizing effects of water, as Tα was shown to correlate with water content via a Gordon-Taylor-like relationship. Our findings validate a new approach for determining the relaxation characteristics of microfiber embedded sugar glasses, and offer new insights into the relaxation characteristics of glasses prepared by microwave-assisted drying on filter papers. PMID:25280724

  18. Determination of the Crystallinity of Semicrystalline Poly(3-hexyl thiophene) by Means of Wide Angle X-Ray Scattering

    NASA Astrophysics Data System (ADS)

    Balko, Jens; Lohwasser, Ruth; Thelakkat, Mukundan; Sommer, Michael; Pascui, Ovidiu; Saalwaechter, Kay; Thurn-Albrecht, Thomas

    2013-03-01

    Poly(3-hexyl thiophene) (P3HT) is a common polymer semiconductor, often used as material or component in organic field effect transistors or solar cells. The crystallinity of this semicrystalline material is among other parameters governing the electronic mobility. However, at present there is no routine method available to determine an absolute value for the crystallinity, and the values given in the literature e.g. for the enthalpy of melting vary by a factor of three. Wide Angle X-Ray Scattering (WAXS) probes the crystals as well the amorphous parts of the sample. We present an approach for the determination of the crystallinity based on the evaluation of WAXS intensities at low scattering vectors emanating from the amorphous regions. The result is used for a calibration of the melting enthalpy (34 J/g) that can serve as a reference value for more convenient calorimetric techniques and compared to the results of recent NMR investigations. We discuss the crystallinity for a number of chemically well-defined samples, with different molecular weight and a typical commercial sample with broad molecular weight distribution. Despite the high crystallinities of 60 to 80% the crystallites exhibit a large amount of disorder.

  19. Number of free hydroxyl groups on bile acid phospholipids determines the fluidity and hydration of model membranes.

    PubMed

    Sreekanth, Vedagopuram; Bajaj, Avinash

    2013-10-10

    Interactions of synthetic phospholipids with model membranes determines the drug release capabilities of phospholipid vesicles at diseased sites. We performed 1,6-diphenyl-1,3,5-hexatriene (DPH)-based fluorescence anisotropy, Laurdan-based membrane hydration, and differential scanning calorimetry (DSC) studies to cognize the interactions of three bile acid phospholipids, lithocholic acid-phosphocholine (LCA-PC), deoxycholic acid-phosphocholine (DCA-PC), and cholic acid-phosphocholine (CA-PC) with model membranes. These studies revealed that bile acid phospholipids increases membrane fluidity in DCA-PC > CA-PC > LCA-PC order, indicating that induction of membrane fluidity is contingent on the number and positioning of free hydroxyl groups on bile acids. Similarly, DCA-PC causes maximum membrane perturbations due to the presence of a free hydroxyl group, whereas LCA-PC induces gel phase in membranes due to hydrophobic bile acid acyl chain interactions. These DCA-PC-induced membrane perturbations induce a drastic decrease in phase transition temperature (Tm) as determined by calorimetric studies, whereas doping of LCA-PC causes phase transition broadening without change in Tm. Doping of CA-PC induces membrane perturbations and membrane hydration like DCA-PC but sharpening of phase transition at higher doping suggests self-association of CA-PC molecules. Therefore these differential mode of interactions between bile acid phospholipids and model membranes would help in the future for their use in drug delivery. PMID:24079709

  20. [Medical practice in Rome during the XVI century].

    PubMed

    Fagiolo, Enzo

    2003-01-01

    S. Filippo Neri (1515-1595), founder of the Congregazione dell'Oratorio in Rome, was a longly debated clinic case for his various pathologies. Eminent scientists, like B. Eustachio and A. Cesalpino, treated him and drew up clinical reports, which were inserted in the Canonization Process and also published as scientific works, and which give useful informations about the history of medicine in the second half of the 16th century. Those reports relate, among others, about many diseases like frequent heart palpitation, shaking tremors heat flame and bronchitic fever episodes, that since hte age of thirty affected the saint. Autopsy revealed cardiac hypertrophia and pulmonary artery dilatation over twice the normal diameter. G. M. Lancisi was the first who formulated the hypothesis of an artery aneurysm, which, according to the present knowledge, can be produced by a post-stenotic dilatation of the pulmonary valve and/or pulmonary hypertension. Tremors and flames can be attributed to hyperthyroidism. Doctors who treated S. Filippo Neri and who shoved to be aware of his psychology, considered his pathology due to supernatural causes. Their conclusions can be understood basing on the medical way of thinking of that age, which was still linked to ancient medicine and limited by the biological and medical knowledge of the time. PMID:15682543

  1. Follow-Up of "Harbinger" Readership. Volume XVI, No. 10.

    ERIC Educational Resources Information Center

    Flaherty, Toni

    In spring 1987, a study was conducted at William Rainey Harper College (WRHC) to assess students' perceptions of the campus newspaper, "The Harbinger," in order to assist "Harbinger" staff in meeting student needs. A random sample of 240 degree credit students and 160 non-degree credit students enrolled in fall 1986 were surveyed by mail to…

  2. SPECKLE INTERFEROMETRY AT THE U.S. NAVAL OBSERVATORY. XVI

    SciTech Connect

    Mason, Brian D.; Hartkopf, William I.; Wycoff, Gary L. E-mail: wih@usno.navy.mil

    2011-05-15

    The results of 1031 speckle-interferometric observations of double stars, made with the 26 inch refractor of the U.S. Naval Observatory, are presented. Each speckle-interferometric observation of a system represents a combination of over two thousand short-exposure images. These observations are averaged into 457 mean relative positions and range in separation from 0.''15 to 16.''94, with a median separation of 3.''03. The range in V-band magnitudes for the primary (secondary) of observed targets is 3.1-12.9 (3.2-13.3). This is the sixteenth in a series of papers presenting measurements obtained with this system and covers the period 2009 January 12 through 2009 December 17. Included in these data are 12 older measurements whose positions were previously deemed possibly aberrant, but are no longer classified this way following a confirming observation. Also, 10 pairs with a single observation are herein confirmed. This paper also includes the first data obtained using a new ICCD with fiber optic cables.

  3. Russian Basic Course: Volume XVI, Lessons 72-75.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This volume, one of a series in a Russian course designed to train native English-language speakers to a level 3 proficiency in reading and writing Russian, contains seven units on the following topics: (1) forms and constructions, (2) basic reading texts, (3) grammar with written exercises, (4) oral exercises, (5) reading and translation…

  4. Higher Education: Handbook of Theory and Research, Volume XVI.

    ERIC Educational Resources Information Center

    Smart, John C., Ed.

    This volume contains essays related to various aspects of higher education, focusing on both educational theory and research. The chapters are: (1) "Apologia pro Vita Mia" (Robert Berdahl); (2) "Varieties of Validity: Quality in Qualitative Research" (Yvonna S. Lincoln); (3) "Academic Freedom and Federal Courts in the 1990s: The Legitimation of…

  5. a GIS of SARDINIA'S Coastal Defense System (xvi - XVIII Century)

    NASA Astrophysics Data System (ADS)

    Deidda, M.; Musa, C.; Vacca, G.

    2015-06-01

    The use of GIS as a tool for archival, analysis and representation of geographic information has become significantly popular in many scientific fields that are directly concerned with the "territory" as their object of study. The field of application of GIS, however, has expanded also in other areas, such as those related to humanities and architecture, in which the territory is studied in an "indirect" mode because it constitutes a kind of substrate on which to develop a specific spatial analysis for particular purposes. Among these areas are to be included certainly archeology and restoration, fields in which the GIS has become a useful tool for historical studies. In this work we present a GIS developed for the study of the historical and territorial coastal defense system of Sardinia (16th - 18th century), in order to respond to the need to store, analyze and efficiently manage the information regarding cultural heritage and landscape heritage such as that consisting of the coastal defensive towers of Sardinia. This defensive system, in fact, was composed by over 100 towers positioned around the entire coastal perimeter of Sardinia, of which more than 90 still exist today. Their position was planned on the basis of the following criteria: - Warning the neighboring towers about the sighting of enemy ships - Protecting coasts located near the towns - Monitoring the water sources near the coast - Allowing for the full visibility of the coasts of any morphology With this study we also verified, through the use of high resolution and high accuracy DTM (LiDAR) and the topographic databases, whether the positioning criteria specified in the design of the system were respected and effective.

  6. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... CFR 31.7. All student activity accounts shall be audited annually. (h) The school shall provide for...-recognized leagues will abide by those state rules regulating inter-school competition. (d) Until comparable... activities shall be required to have qualified sponsors and be approved by the school supervisor, and...

  7. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... CFR 31.7. All student activity accounts shall be audited annually. (h) The school shall provide for...-recognized leagues will abide by those state rules regulating inter-school competition. (d) Until comparable... activities shall be required to have qualified sponsors and be approved by the school supervisor, and...

  8. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... CFR 31.7. All student activity accounts shall be audited annually. (h) The school shall provide for...-recognized leagues will abide by those state rules regulating inter-school competition. (d) Until comparable... activities shall be required to have qualified sponsors and be approved by the school supervisor, and...

  9. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... CFR 31.7. All student activity accounts shall be audited annually. (h) The school shall provide for...-recognized leagues will abide by those state rules regulating inter-school competition. (d) Until comparable... activities shall be required to have qualified sponsors and be approved by the school supervisor, and...

  10. Twist, tilt, and orientational order at the nematic to twist-bend nematic phase transition of 1″,9″-bis(4-cyanobiphenyl-4'-yl) nonane: A dielectric, 2H NMR, and calorimetric study

    NASA Astrophysics Data System (ADS)

    Robles-Hernández, Beatriz; Sebastián, Nerea; de la Fuente, M. Rosario; López, David O.; Diez-Berart, Sergio; Salud, Josep; Ros, M. Blanca; Dunmur, David A.; Luckhurst, Geoffrey R.; Timimi, Bakir A.

    2015-12-01

    The nature of the nematic-nematic phase transition in the liquid crystal dimer 1″,9″-bis(4-cyanobiphenyl-4'-yl) nonane (CB9CB) has been investigated using techniques of calorimetry, dynamic dielectric response measurements, and 2H NMR spectroscopy. The experimental results for CB9CB show that, like the shorter homologue CB7CB, the studied material exhibits a normal nematic phase, which on cooling undergoes a transition to the twist-bend nematic phase (NTB), a uniaxial nematic phase, promoted by the average bent molecular shape, in which the director tilts and precesses describing a conical helix. Modulated differential scanning calorimetry has been used to analyze the nature of the NTB-N phase transition, which is found to be weakly first order, but close to tricritical. Additionally broadband dielectric spectroscopy and 2H magnetic resonance studies have revealed information on the structural characteristics of the recently discovered twist-bend nematic phase. Analysis of the dynamic dielectric response in both nematic phases has provided an estimate of the conical angle of the heliconical structure for the NTB phase. Capacitance measurements of the electric-field realignment of the director in initially planar aligned cells have yielded values for the splay and bend elastic constants in the high temperature nematic phase. The bend elastic constant is small and decreases with decreasing temperature as the twist-bend phase is approached. This behavior is expected theoretically and has been observed in materials that form the twist-bend nematic phase. 2H NMR measurements characterize the chiral helical twist identified in the twist-bend nematic phase and also allow the determination of the temperature dependence of the conical angle and the orientational order parameter with respect to the director.

  11. An improved single crystal adsorption calorimeter for determining gas adsorption and reaction energies on complex model catalysts

    NASA Astrophysics Data System (ADS)

    Fischer-Wolfarth, Jan-Henrik; Hartmann, Jens; Farmer, Jason A.; Flores-Camacho, J. Manuel; Campbell, Charles T.; Schauermann, Swetlana; Freund, Hans-Joachim

    2011-02-01

    A new ultrahigh vacuum microcalorimeter for measuring heats of adsorption and adsorption-induced surface reactions on complex single crystal-based model surfaces is described. It has been specifically designed to study the interaction of gaseous molecules with well-defined model catalysts consisting of metal nanoparticles supported on single crystal surfaces or epitaxial thin oxide films grown on single crystals. The detection principle is based on the previously described measurement of the temperature rise upon adsorption of gaseous molecules by use of a pyroelectric polymer ribbon, which is brought into mechanical/thermal contact with the back side of the thin single crystal. The instrument includes (i) a preparation chamber providing the required equipment to prepare supported model catalysts involving well-defined nanoparticles on clean single crystal surfaces and to characterize them using surface analysis techniques and in situ reflectivity measurements and (ii) the adsorption/reaction chamber containing a molecular beam, a pyroelectric heat detector, and calibration tools for determining the absolute reactant fluxes and adsorption heats. The molecular beam is produced by a differentially pumped source based on a multichannel array capable of providing variable fluxes of both high and low vapor pressure gaseous molecules in the range of 0.005-1.5 × 1015 molecules cm-2 s-1 and is modulated by means of the computer-controlled chopper with the shortest pulse length of 150 ms. The calorimetric measurements of adsorption and reaction heats can be performed in a broad temperature range from 100 to 300 K. A novel vibrational isolation method for the pyroelectric detector is introduced for the reduction of acoustic noise. The detector shows a pulse-to-pulse standard deviation ≤15 nJ when heat pulses in the range of 190-3600 nJ are applied to the sample surface with a chopped laser. Particularly for CO adsorption on Pt(111), the energy input of 15 nJ (or 120 nJ cm

  12. An improved single crystal adsorption calorimeter for determining gas adsorption and reaction energies on complex model catalysts.

    PubMed

    Fischer-Wolfarth, Jan-Henrik; Hartmann, Jens; Farmer, Jason A; Flores-Camacho, J Manuel; Campbell, Charles T; Schauermann, Swetlana; Freund, Hans-Joachim

    2011-02-01

    A new ultrahigh vacuum microcalorimeter for measuring heats of adsorption and adsorption-induced surface reactions on complex single crystal-based model surfaces is described. It has been specifically designed to study the interaction of gaseous molecules with well-defined model catalysts consisting of metal nanoparticles supported on single crystal surfaces or epitaxial thin oxide films grown on single crystals. The detection principle is based on the previously described measurement of the temperature rise upon adsorption of gaseous molecules by use of a pyroelectric polymer ribbon, which is brought into mechanical∕thermal contact with the back side of the thin single crystal. The instrument includes (i) a preparation chamber providing the required equipment to prepare supported model catalysts involving well-defined nanoparticles on clean single crystal surfaces and to characterize them using surface analysis techniques and in situ reflectivity measurements and (ii) the adsorption∕reaction chamber containing a molecular beam, a pyroelectric heat detector, and calibration tools for determining the absolute reactant fluxes and adsorption heats. The molecular beam is produced by a differentially pumped source based on a multichannel array capable of providing variable fluxes of both high and low vapor pressure gaseous molecules in the range of 0.005-1.5 × 10(15) molecules cm(-2) s(-1) and is modulated by means of the computer-controlled chopper with the shortest pulse length of 150 ms. The calorimetric measurements of adsorption and reaction heats can be performed in a broad temperature range from 100 to 300 K. A novel vibrational isolation method for the pyroelectric detector is introduced for the reduction of acoustic noise. The detector shows a pulse-to-pulse standard deviation ≤15 nJ when heat pulses in the range of 190-3600 nJ are applied to the sample surface with a chopped laser. Particularly for CO adsorption on Pt(111), the energy input of 15 n

  13. Calorimetric studies of the heats of protonation of the dangling phosphorus in [eta][sup 1]-Ph[sub 2]PCH[sub 2]PPh[sub 2] complexes of chromium, molybdenum, and tungsten

    SciTech Connect

    Rottink, M.K.; Angelici, R.J. )

    1993-05-26

    Titration calorimetry has been used to determine the heats of protonation ([Delta]H[sub HP]) of M(CO)[sub 5]([eta][sup 1]-dppm) (M = Cr, Mo, W) and fac-M(CO)[sub 3](N-N)([eta][sup 1]-dppm) (M = Mo, N-N = bipy, phen; M = w, N-N = bipy) complexes with CF[sub 3]SO[sub 3]H in 1,2-dichloroethane solvent at 25.0 [degrees]C. Spectroscopic studies show that protonation occurs at the uncoordinated phosphorus atom of the [eta][sup 1]-coordinated dppm (Ph[sub 2]PCH[sub 2]PPh[sub 2]) ligand. For dppm, its monoprotonated form (dppmH[sup +]), and these complexes, the basicity ([Delta]H[sub HP]) of the dangling phosphorus increases from -14.9 kcal/mol to -23.1 kcal/mol in the order: dppmH[sup +]

  14. Study the penetration of IR laser radiation in human teeth: determination of the absorbed and scattered parts

    NASA Astrophysics Data System (ADS)

    Uzunova, Pepa; Rabadgiiska, Stanislava; Uzunov, Tzonko; Kisov, Hristo; Kaimakanova, Nadejda; Deneva, Margarita; Dinkov, Emil; Nenchev, Marin

    2013-03-01

    By using the developed by us approaches and instrumentation, we have obtained and presented series of systematized data, which are important for the use of the laser light in infrared (IR) spectral region. The obtained data include: 1) reflectivity of the human tooth dentin; 2) the spatial intensity distribution in the cross-section of the light beam penetrating the tooth's dentin; 3) the absorbed and the diffused parts of the laser light that have been determined separately through combination of optical and calorimetric techniques. The last result is the most important because it permits to calculate the dentin absorption and scattering coefficients. The study is performed for the laser light at two easily generated wavelengths - 1.06 μm and 1.36 μm, emitted by the Nd:YAG laser that is well known, commercially available, economical and widely used in many laboratories and medical institutions. The study is made on the basis of fresh in-vitro teeth samples from the persons of Bulgaria, Sofia region.

  15. Thermal characterization of Li-ion cells using calorimetric techniques

    SciTech Connect

    ROTH,EMANUEL P.

    2000-05-31

    The thermal stability of Li-ion cells with intercalating carbon anodes and metal oxide cathodes was measured as a function of state of charge and temperature for two advanced cell chemistries. Cells of the 18650 design with Li{sub x}CoO{sub 2} cathodes (commercial Sony cells) and Li{sub x}Ni{sub 0.8}Co{sub 0.2}O{sub 2} cathodes were measured for thermal reactivity. Accelerating rate calorimetry (ARC) was used to measure cell thermal runaway as a function of state of charge (SOC), microcalorimetry was used to measure the time dependence of thermal output, and differential scanning calorimetry (DSC) was used to study the thermal reactivity of the individual components. Thermal decomposition of the anode solid electrolyte interphase (SEI) layer occurred at low temperatures and contributes to the initiation of thermal runaway. Low temperature reactions from 40 C--70 C were observed during the ARC runs that were SOC dependent. These reactions measured in the microcalorimeter decayed over time with power-law dependence and were highly sensitive to SOC and temperature. ARC runs of aged and cycled cells showed complete absence of these low-temperature reactions but showed abrupt exothermic spikes between 105--135 C. These results suggest that during aging the anode SEI layer is decomposing from a metastable state to a stable composition that is breaking down at elevated temperatures.

  16. Calorimetric glass transition in a mean-field theory approach

    PubMed Central

    Mariani, Manuel Sebastian; Parisi, Giorgio; Rainone, Corrado

    2015-01-01

    The study of the properties of glass-forming liquids is difficult for many reasons. Analytic solutions of mean-field models are usually available only for systems embedded in a space with an unphysically high number of spatial dimensions; on the experimental and numerical side, the study of the properties of metastable glassy states requires thermalizing the system in the supercooled liquid phase, where the thermalization time may be extremely large. We consider here a hard-sphere mean-field model that is solvable in any number of spatial dimensions; moreover, we easily obtain thermalized configurations even in the glass phase. We study the 3D version of this model and we perform Monte Carlo simulations that mimic heating and cooling experiments performed on ultrastable glasses. The numerical findings are in good agreement with the analytical results and qualitatively capture the features of ultrastable glasses observed in experiments. PMID:25675523

  17. Two Calorimetrically Distinct States of Liquid Water Below 150 Kelvin

    PubMed

    Johari; Hallbrucker; Mayer

    1996-07-01

    Vapor-deposited amorphous solid and hyperquenched glassy water were found to irreversibly transform, on compression at 77 kelvin, to a high-density amorphous solid. On heating at atmospheric pressure, this solid became viscous water (water B), with a reversible glass-liquid transition onset at 129 +/- 2 kelvin. A different form of viscous water (water A) was formed by heating the uncompressed vapor-deposited amorphous solid and hyperquenched liquid water. On thermal cycling up to 148 kelvin, water B remained kinetically and thermodynamically distinct from water A. The occurrence of these two states, which do not interconvert, helps explain both the configurational relaxation of water and stress-induced amorphization. PMID:8688057

  18. Calorimetric calibration of pyroelectric gamma-radiation detectors

    SciTech Connect

    Strakovskaya, R.Y.; Sras', A.G.

    1985-07-01

    A method has been devised for calibrating a pyroelectric dosimeter, which is based on comparing the readings obtained with it in a gamma-ray beam with the readings of an integral calorimeter under stationary conditions, with the latter previously calibrated from Joule heat. The calorimeter used was in the form of a closed shell, whose overall thermo-emf was independent of the spatial distribution of the heat sources in it, the value being proportional to the integral heat flux through the shell. Measurements were made not only with a quasiisotropic radiation field but also in directed fields. The overall error in calibrating the pyroelectric detectors by this method was less than or equal to plus or minus 10%.

  19. Calorimetric thermometry of meteoritic troilite: Preliminary thermometer relationships

    NASA Technical Reports Server (NTRS)

    Allton, Judith H.; Wentworth, Susan J.; Gooding, James L.

    1994-01-01

    Thermodynamic properties of the alpha/beta phase transformation in terrestrial troilite (FeS), as measured by differential scanning calorimetry (DSC), vary systematically with prior thermal history of the troilite, as imposed under laboratory conditions. Both the transition temperature and enthalpy change for the alpha/beta transformation decrease with increasing maximum temperature of prior heat treatment. DSC measurements on troilite from various meteorites indicate clear differences in the alpha/beta thermodynamic properties that are consistent with differences in the natural thermal histories of the meteorites.

  20. Calorimetric studies of the elongation of Avena coleoptile segments.

    PubMed

    Bogie, H E; Kresheck, G C; Harmet, K H

    1976-06-01

    Elongation rate and heat produced by Avena coleoptile segments suspended in sucrose buffer solutions were measured at pH values from 3.5 to 8.5. The caloric efficiency of elongation (CEE) was defined as the ratio of the rate of elongation to the rate of heat production. Elongation and CEE were greatest at intermediate pH values, but heat production (about 1 cal/g.hr) was insensitive to pH within the limits of experimental error (+/-20%). Quantitative agreement was found between the results of previous respiration studies and the rate of heat production in an aerobic atmosphere, which indicates that oxidative metabolism accounts for essentially all energy changes in the cell, so matter flow is a significant component of the bioenergetics of cell function. Indole-3-acetic acid up to 1 mm, produced about a 10-fold increase in elongation rate, a 5-fold increase of the CEE, and a 25% increase in heat production. Above this concentration, sharp drops in both elongation and heat production occurred, without altering the CEE at pH 6.5, but greatly decreasing the CEE at pH 4.5. Elongation and CEE showed marked decreases after 4 hours in an anaerobic atmosphere, but heat production did not exhibit a proportional decrease. These studies indicate that rate of cell elongation in the presence and absence of auxin is not directly proportional to the overall metabolism of the cell. PMID:16659582

  1. Calorimetric study of Skyrmionic chiral magnet MnSi

    NASA Astrophysics Data System (ADS)

    Samatham, S. Shanmukharao; Ganesan, V.

    2014-04-01

    We present the analysis of specific internal energy as a function of magnetic fields in ordered, intermediate and paramagnetic phases of MnSi. Signatures of the formation of Skyrmion lattice, in conical order region, is identified by a hump-like structure in region-I. Gradual melting of blue phase, with magnetic fields, is demonstrated.

  2. A calorimetric study of precipitation in aluminum alloy 2219

    NASA Astrophysics Data System (ADS)

    Papazian, John M.

    1981-02-01

    Precipitate microstructures in aluminum alloy 2219 were characterized using transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The DSC signatures of individual precipitate phases were established by comparing the DSC and TEM results from samples that had been aged such that only one precipitate phase was present. These signatures were then used to analyze the commercial tempers. It was found that DSC could readily distinguish between the T3, T4, T6, T8 and O tempers but could not distinguish amongst T81, T851 and T87. Small amounts of plastic deformation between solution treatment and aging had a significant effect on the thermograms. Aging experiments at 130 and 190 °C showed that the aging sequence and DSC response of this alloy were similar to those of pure Al-Cu when the increased copper content is taken into account. Further aging experiments at temperatures between room temperature and 130 °C showed pronounced changes of the GP zone dissolution peak as a function of aging conditions. These changes were found to be related to the effect of GP zone size on the metastable phase boundary and on the GP zone dissolution kinetics.

  3. Superconducting calorimetric alpha particle sensors for nuclear nonproliferation applications

    SciTech Connect

    Horansky, Robert D.; Ullom, Joel N.; Beall, James A.; Hilton, Gene C.; Irwin, Kent D.; Dry, Donald E.; Hastings, Elizabeth P.; Lamont, Stephen P.; Rudy, Clifford R.; Rabin, Michael W.

    2008-09-22

    Identification of trace nuclear materials is usually accomplished by alpha spectrometry. Current detectors cannot distinguish critical elements and isotopes. We have developed a detector called a microcalorimeter, which achieves a resolution of 1.06 keV for 5.3 MeV alphas, the highest resolving power of any energy dispersive measurement. With this exquisite resolution, we can unambiguously identify the {sup 240}Pu/{sup 239}Pu ratio in Pu, a critical measurement for ascertaining the intended use of nuclear material. Furthermore, we have made a direct measurement of the {sup 209}Po ground state decay.

  4. Simulated performance of the calorimetric electron telescope (CALET) experiment

    NASA Astrophysics Data System (ADS)

    Akaike, Y.; Taira, K.; Kasahara, K.; Torii, S.; Shimizu, Y.; Yoshida, K.; CALET Collaboration

    2010-03-01

    CALET is a detector planned to be on-board the Japanese Experiment Module Exposed Facility (JEM-EF) of the International Space Station. The CALET mission aims at revealing unsolved problems in high energy phenomena of the Universe by carrying out a precise measurement of the high energy electrons in 1 GeV-20 TeV, the gamma-rays in 20 MeV to a few TeV and the nuclei in a few 10 GeV-1000 TeV. The main detector is composed of imaging calorimeter (IMC), total absorption calorimeter (TASC), silicon pixel array (SIA) and anti-coincidence detector (ACD) to detect various kinds of particles in very wide energy range. The total absorber thickness is 31 radiation lengths for electromagnetic particles and 1.4 interaction mean free paths for protons. Monte Carlo simulation study has been carried out for optimization of the detector performance in observing each kind of particles. We obtained following performance about the observation of very high energy (>100 GeV) electrons, which is a main target of the CALET experiment: (1) Effective geometrical factor is about 7000 cm2 sr. (2) Energy resolution is better than a few %. (3) Angular resolution is better than 0.1°. (4) Proton rejection power is ˜105 with the electron detection efficiency better than 95%. We also present the simulated performance of the CALET experiment in observing other particles.

  5. Binding of nucleotides to nucleoside diphosphate kinase: a calorimetric study.

    PubMed

    Cervoni, L; Lascu, I; Xu, Y; Gonin, P; Morr, M; Merouani, M; Janin, J; Giartosio, A

    2001-04-17

    The source of affinity for substrates of human nucleoside diphosphate (NDP) kinases is particularly important in that its knowledge could be used to design more effective antiviral nucleoside drugs (e.g., AZT). We carried out a microcalorimetric study of the binding of enzymes from two organisms to various nucleotides. Isothermal titration calorimetry has been used to characterize the binding in terms of Delta G degrees, Delta H degrees and Delta S degrees. Thermodynamic parameters of the interaction of ADP with the hexameric NDP kinase from Dictyostelium discoideum and with the tetrameric enzyme from Myxococcus xanthus, at 20 degrees C, were similar and, in both cases, binding was enthalpy-driven. The interactions of ADP, 2'deoxyADP, GDP, and IDP with the eukaryotic enzyme differed in enthalpic and entropic terms, whereas the Delta G degrees values obtained were similar due to enthalpy--entropy compensation. The binding of the enzyme to nonphysiological nucleotides, such as AMP--PNP, 3'deoxyADP, and 3'-deoxy-3'-amino-ADP, appears to differ in several respects. Crystallography of the protein bound to 3'-deoxy-3'-amino-ADP showed that the drug was in a distorted position, and was unable to interact correctly with active site side chains. The interaction of pyrimidine nucleoside diphosphates with the hexameric enzyme is characterized by a lower affinity than that with purine nucleotides. Titration showed the stoichiometry of the interaction to be abnormal, with 9--12 binding sites/hexamer. The presence of supplementary binding sites might have physiological implications. PMID:11294625

  6. Calorimetric studies of the growth of anaerobic microbes.

    PubMed

    Miyake, Hideo; Maeda, Yukiko; Ishikawa, Takashi; Tanaka, Akiyoshi

    2016-09-01

    This article aims to validate the use of calorimetry to measure the growth of anaerobic microbes. It has been difficult to monitor the growth of strict anaerobes while maintaining optimal growth conditions. Traditionally, optical density and ATP concentration are usually used as measures of the growth of anaerobic microbes. However, to take these measurements it is necessary to extract an aliquot of the culture, which can be difficult while maintaining anaerobic conditions. In this study, calorimetry was used to continuously and nondestructively measure the heat generated by the growth of anaerobic microbes as a function of time. Clostridium acetobutylicum, Clostridium beijerinckii, and Clostridium cellulovorans were used as representative anaerobic microbes. Using a multiplex isothermal calorimeter, we observed that peak time (tp) of C. acetobutylicum heat evolution increased as the inoculation rate decreased. This strong correlation between the inoculation rate and tp showed that it was possible to measure the growth rate of anaerobic microbes by calorimetry. Overall, our results showed that there is a very good correlation between heat evolution and optical density/ATP concentration, validating the use of the method. PMID:27012376

  7. NUSAT 1 attitude determination

    NASA Technical Reports Server (NTRS)

    Talaga, Paul

    1987-01-01

    This paper presents the methods for attitude determination using the static wide angle field of view sensors of NUSAT 1. Some supporting analysis and operational results are given. The system gives at best a crude attitude determination.

  8. Rethinking the Category 'Determiner'

    ERIC Educational Resources Information Center

    Spangler, Wayne E.

    1975-01-01

    The 'determiner' category was originally set up by structuralists for identifying nouns. The rewrite rule for 'determiners' in transformational generative grammar is inadequate for showing correspondences between type and token. An appraisal of quantity terms might eliminate the concept of the 'determiner,' and replace that category with one of…

  9. CALORIMETER-BASED ADJUSTMENT OF MULTIPLICITY DETERMINED 240PU EFF KNOWN-A ANALYSIS FOR THE ASSAY OF PLUTONIUM

    SciTech Connect

    Dubose, F.

    2012-02-21

    In nuclear material processing facilities, it is often necessary to balance the competing demands of accuracy and throughput. While passive neutron multiplicity counting is the preferred method for relatively fast assays of plutonium, the presence of low-Z impurities (fluorine, beryllium, etc.) rapidly erodes the assay precision of passive neutron counting techniques, frequently resulting in unacceptably large total measurement uncertainties. Conversely, while calorimeters are immune to these impurity effects, the long count times required for high accuracy can be a hindrance to efficiency. The higher uncertainties in passive neutron measurements of impure material are driven by the resulting large (>>2) {alpha}-values, defined as the ({alpha},n):spontaneous fission neutron emission ratio. To counter impurity impacts for high-{alpha} materials, a known-{alpha} approach may be adopted. In this method, {alpha} is determined for a single item using a combination of gamma-ray and calorimetric measurements. Because calorimetry is based on heat output, rather than a statistical distribution of emitted neutrons, an {alpha}-value determined in this way is far more accurate than one determined from passive neutron counts. This fixed {alpha} value can be used in conventional multiplicity analysis for any plutonium-bearing item having the same chemical composition and isotopic distribution as the original. With the results of single calorimeter/passive neutron/gamma-ray measurement, these subsequent items can then be assayed with high precision and accuracy in a relatively short time, despite the presence of impurities. A calorimeter-based known-{alpha} multiplicity analysis technique is especially useful when requiring rapid, high accuracy, high precision measurements of multiple plutonium bearing items having a common source. The technique has therefore found numerous applications at the Savannah River Site. In each case, a plutonium (or mixed U/Pu) bearing item is divided

  10. Nephelometric determination of fluorine

    USGS Publications Warehouse

    Stevens, R.E.

    1936-01-01

    Fluorine in minerals may be determined with the nephelometer to about 1 per cent of the fluorine. The determination is made on an aliquot of the sodium chloride solution of the fluorine, obtained by the Berzelius method of extraction. The fluorine is precipitated as colloidal calcium fluoride in alcoholic solution, gelatin serving as a protective colloid. Arsenates, sulfates, and phosphates, which interfere with the determination, must be removed.

  11. Sex Determination in Papaya

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sex determination is an intriguing system in trioecious papaya. Over the past seven decades various hypotheses, based on the knowledge and information available at the time, have been proposed to explain the genetics of the papaya's sex determination. These include a single gene with three alleles...

  12. Determinants of Education Achievement.

    ERIC Educational Resources Information Center

    Lave, Charles; And Others

    1981-01-01

    A model is tested of the determinants of educational attainment among peasants on Mexico's Yucatan Peninsula, involving family background, personal characteristics (including IQ), and years of schooling available. Results indicate that the model explains much of the variance in educational attainment, and that IQ is only a minor determinant. (RW)

  13. Spacecraft Attitude Determination Methods

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis; Bauer, Frank H. (Technical Monitor)

    2000-01-01

    This document is presentation in viewgraph form, which outlines the methods of determining spacecraft attitude. The presentation reviews several parameterizations relating to spacecraft attitude, such as Euler's Theorem, Rodriques parameters, and Euler-Rodriques parameters or Quaternion. Onboard attitude determination is the norm, using either single frame or filtering methods. The presentation reviews several mathematical representations of attitude. The mechanisms for determining attitude on board the Hubble Space Telescope, the Tropical Rainfall and Measuring Mission and the Solar Anomalous and Magnetospheric Particle Explorer are reviewed. Wahba's problem, Procrustes Problem, and some solutions are also summarized.

  14. Temperature determination using pyrometry

    DOEpatents

    Breiland, William G.; Gurary, Alexander I.; Boguslavskiy, Vadim

    2002-01-01

    A method for determining the temperature of a surface upon which a coating is grown using optical pyrometry by correcting Kirchhoff's law for errors in the emissivity or reflectance measurements associated with the growth of the coating and subsequent changes in the surface thermal emission and heat transfer characteristics. By a calibration process that can be carried out in situ in the chamber where the coating process occurs, an error calibration parameter can be determined that allows more precise determination of the temperature of the surface using optical pyrometry systems. The calibration process needs only to be carried out when the physical characteristics of the coating chamber change.

  15. Ultrasonic material property determinations

    NASA Technical Reports Server (NTRS)

    Serabian, S.

    1986-01-01

    The use and potential offered by ultrasonic velocity and attenuation measurements to determine and/or monitor material properties is explored. The basis for such unique measurements along with examples of materials from a variety of industries are presented.

  16. Protein Nitrogen Determination

    NASA Astrophysics Data System (ADS)

    Nielsen, S. Suzanne

    The protein content of foods can be determined by numerous methods. The Kjeldahl method and the nitrogen combustion (Dumas) method for protein analysis are based on nitrogen determination. Both methods are official for the purposes of nutrition labeling of foods. While the Kjeldahl method has been used widely for over a hundred years, the recent availability of automated instrumentation for the Dumas method in many cases is replacing use of the Kjeldahl method.

  17. Determining postural stability

    NASA Technical Reports Server (NTRS)

    Lieberman, Erez (Inventor); Forth, Katharine E. (Inventor); Paloski, William H. (Inventor)

    2011-01-01

    A method for determining postural stability of a person can include acquiring a plurality of pressure data points over a period of time from at least one pressure sensor. The method can also include the step of identifying a postural state for each pressure data point to generate a plurality of postural states. The method can include the step of determining a postural state of the person at a point in time based on at least the plurality of postural states.

  18. Solids mass flow determination

    DOEpatents

    Macko, Joseph E.

    1981-01-01

    Method and apparatus for determining the mass flow rate of solids mixed with a transport fluid to form a flowing mixture. A temperature differential is established between the solids and fluid. The temperature of the transport fluid prior to mixing, the temperature of the solids prior to mixing, and the equilibrium temperature of the mixture are monitored and correlated in a heat balance with the heat capacities of the solids and fluid to determine the solids mass flow rate.

  19. Synthesis of crystalline americium hydroxide, Am(OH){sub 3}, and determination of its enthalpy of formation; estimation of the solubility-product constants of actinide(III) hydroxides

    SciTech Connect

    Morss, L.R.; Williams, C.W.

    1993-12-31

    This paper reports a new synthesis of pure, microcrystalline Am(OH){sub 3}, its characterization by x-ray powder diffraction and infrared spectroscopy, and the calorimetric determination of its enthalpy of solution in dilute hydrochloric acid. From the enthalpy of solution the enthalpy of formation of Am(OH){sub 3} has been calculated to be {minus}1371.2{plus_minus}7.9 kj{center_dot}mol{sup {minus}1}, which represents the first experimental determination of an enthalpy of formation of any actinide hydroxide. The free energy of formation and solubility product constant of Am(OH){sub 3} (K{sub sp} = 7 {times} 10{sup {minus}31}) have been calculated from our enthalpy of formation and entropy estimates and are compared with literature measurements under near-equilibrium conditions. Since many properties of the tripositive lanthanide and actinide ions (e.g., hydrolysis, complex-ion formation, and thermochemistry) change in a regular manner, these properties can be interpreted systematically in terms of ionic size. This paper compares the thermochemistry of Am(OH){sub 3} with thermochemical studies of lanthanide hydroxides. A combined structural and acid-base model is used to explain the systematic differences in enthalpies of solution between the oxides and hydroxides of the 4f{sup n} and 5f{sup n} subgroups and to predict solubility-product constants for the actinide(III) hydroxides of Pu through Cf.

  20. HEU age determination

    SciTech Connect

    Moorthy, A.R.; Kato, W.Y.

    1997-07-01

    A new technique has been developed to determine the age of highly enriched uranium (HEU) in solids. Uranium age is defined as the time since the uranium-containing material was last subjected to a process capable of separating uranium from its radioactive-decay daughters. [Most chemical processing, uranium enrichment, volatilization processes, and phase transformations (especially relevant for uranium hexafluoride) can result in separation of the uranium parent material from the decay-product daughters.] Determination of the uranium age, as defined here, may be relevant in verifying arms-control agreements involving uranium-containing nuclear weapons. The HEU age is determined from the ratios of relevant uranium daughter isotopes and their parents, viz {sup 230}Th/{sup 234}U and {sup 231}Pa/{sup 235}U. Uranium isotopes are quantitatively measured by their characteristic gamma rays and their daughters by alpha spectroscopy. In some of the samples, where HEU is enriched more than 99%, the only mode of HEU age determination is by the measurement of {sup 231}Pa since there is negligible quantity of {sup 230}Th due to very low atom concentrations of {sup 234}U in the samples. In this report the methodology and the data for determining the age of two HEU samples are presented.

  1. Metal hydride differential scanning calorimetry as an approach to compositional determination of mixtures of hydrogen isotopologues and helium

    DOE PAGESBeta

    Robinson, David B.; Luo, Weifang; Cai, Trevor Y.; Stewart, Kenneth D.

    2015-09-26

    Gaseous mixtures of diatomic hydrogen isotopologues and helium are often encountered in the nuclear energy industry and in analytical chemistry. Compositions of stored mixtures can vary due to interactions with storage and handling materials. When tritium is present, it decays to form ions and helium-3, both of which can lead to further compositional variation. Monitoring of composition is typically achieved by mass spectrometry, a method that is bulky and energy-intensive. Mass spectrometers disperse sample material through vacuum pumps, which is especially troublesome if tritium is present. Moreover, our ultimate goal is to create a compact, fast, low-power sensor that canmore » determine composition with minimal gas consumption and waste generation, as a complement to mass spectrometry that can be instantiated more widely. We propose calorimetry of metal hydrides as an approach to this, due to the strong isotope effect on gas absorption, and demonstrate the sensitivity of measured heat flow to atomic composition of the gas. Peak shifts are discernible when mole fractions change by at least 1%. A mass flow restriction results in a unique dependence of the measurement on helium concentration. We present a mathematical model as a first step toward prediction of the peak shapes and positions. The model includes a useful method to compute estimates of phase diagrams for palladium in the presence of arbitrary mixtures of hydrogen isotopologues. As a result, we expect that this approach can be used to deduce unknown atomic compositions from measured calorimetric data over a useful range of partial pressures of each component.« less

  2. Metal hydride differential scanning calorimetry as an approach to compositional determination of mixtures of hydrogen isotopologues and helium

    SciTech Connect

    Robinson, David B.; Luo, Weifang; Cai, Trevor Y.; Stewart, Kenneth D.

    2015-09-26

    Gaseous mixtures of diatomic hydrogen isotopologues and helium are often encountered in the nuclear energy industry and in analytical chemistry. Compositions of stored mixtures can vary due to interactions with storage and handling materials. When tritium is present, it decays to form ions and helium-3, both of which can lead to further compositional variation. Monitoring of composition is typically achieved by mass spectrometry, a method that is bulky and energy-intensive. Mass spectrometers disperse sample material through vacuum pumps, which is especially troublesome if tritium is present. Moreover, our ultimate goal is to create a compact, fast, low-power sensor that can determine composition with minimal gas consumption and waste generation, as a complement to mass spectrometry that can be instantiated more widely. We propose calorimetry of metal hydrides as an approach to this, due to the strong isotope effect on gas absorption, and demonstrate the sensitivity of measured heat flow to atomic composition of the gas. Peak shifts are discernible when mole fractions change by at least 1%. A mass flow restriction results in a unique dependence of the measurement on helium concentration. We present a mathematical model as a first step toward prediction of the peak shapes and positions. The model includes a useful method to compute estimates of phase diagrams for palladium in the presence of arbitrary mixtures of hydrogen isotopologues. As a result, we expect that this approach can be used to deduce unknown atomic compositions from measured calorimetric data over a useful range of partial pressures of each component.

  3. Determinants of marriage dissolution

    NASA Astrophysics Data System (ADS)

    Rahim, Mohd Amirul Rafiq Abu; Shafie, Siti Aishah Mohd; Hadi, Az'lina Abdul; Razali, Nornadiah Mohd; Azid @ Maarof, Nur Niswah Naslina

    2015-10-01

    Nowadays, the number of divorce cases among Muslim couples is very worrisome whereby the total cases reported in 2013 increased by half of the total cases reported in the previous year. The questions on the true key factors of dissolution of marriage continue to arise. Thus, the objective of this study is to reveal the factors that contribute to the dissolution of marriage. A total of 181 cases and ten potential determinants were included in this study. The potential determinants considered were age at marriage of husband and wife, educational level of husband and wife, employment status of husband and wife, income of husband and wife, the number of children and the presence at a counseling session. Logistic regression analysis was used to analyze the data. The findings revealed that four determinants, namely the income of husband and wife, number of children and the presence at a counselling session were significant in predicting the likelihood of divorce among Muslim couples.

  4. HEU age determination

    SciTech Connect

    Moorthy, A.R.; Kato, W.Y.

    1995-08-01

    A technique has been developed to determine the Highly Enriched Uranium (HEU) Age which is defined as the time since the HEU was produced in an enrichment process. The HEU age is determined from the ratios of relevant uranium parents and their daughters viz {sup 230}Th/{sup 234}U and {sup 231}Pa/{sup 235}U. Uranium isotopes are quantitatively measured by their characteristic gammas and their daughters by alpha spectroscopy. In some of the samples where HEU is enriched more than 99%, the only mode of HEU age determination is by the measurement of {sup 231}Pa since there is negligible quantity of {sup 230}Th due to very low atom concentrations of {sup 234}U in the sample. In this paper we have presented data and methodology of finding the age of two HEU samples.

  5. Ultrasonic determination of recrystallization

    NASA Technical Reports Server (NTRS)

    Generazio, E. R.

    1986-01-01

    Ultrasonic attenuation was measured for cold worked Nickel 200 samples annealed at increasing temperatures. Localized dislocation density variations, crystalline order and colume percent of recrystallized phase were determined over the anneal temperature range using transmission electron microscopy, X-ray diffraction, and metallurgy. The exponent of the frequency dependence of the attenuation was found to be a key variable relating ultrasonic attenuation to the thermal kinetics of the recrystallization process. Identification of this key variable allows for the ultrasonic determination of onset, degree, and completion of recrystallization.

  6. Implementation of water calorimetry in a 180 MeV scanned pulsed proton beam including an experimental determination of kQ for a Farmer chamber

    NASA Astrophysics Data System (ADS)

    Medin, Joakim

    2010-06-01

    Water calorimetric measurements have been performed in a 180 MeV scanned pulsed proton beam and the absorbed dose determined has been compared with the results obtained using two NE2571 Farmer chambers and the IAEA TRS-398 code of practice. The depth of measurement in water corresponded to a residual range of Rres = 16.5 cm, corresponding to a mean energy of about 150 MeV. Ionization chambers were calibrated in terms of the absorbed dose to water in 60Co at the Swedish Secondary Standard Dosimetry Laboratory, directly traceable to Bureau International des Poids et Mesures. The present experimental investigation has shown that water calorimetry is feasible in a high-energy scanned pulsed proton beam. When comparing the results obtained with water calorimetry and ionometry, the beam quality correction factor, kQ, could be determined for the two NE2571 ionization chambers used. The kQ-factor was found to be 1.032 ± 0.013, which is in good agreement with the factor tabulated in IAEA TRS-398 for this chamber type (1.039 ± 0.018). The present result has also been compared with a previously obtained result in a passively scattered proton beam having similar energy. This comparison yielded a 1.1% deviation, which is not significant considering the combined uncertainties of the two experimental determinations of kQ. The dominating contribution to the combined uncertainty stems from the correction factor for ion recombination in the scanned proton beam (1%), and further studies are required in order to reduce this uncertainty and reveal any possible differences in the kQ-factor between these two proton beam delivery techniques.

  7. Determinants of project success

    NASA Technical Reports Server (NTRS)

    Murphy, D. C.; Baker, B. N.; Fisher, D.

    1974-01-01

    The interactions of numerous project characteristics, with particular reference to project performance, were studied. Determinants of success are identified along with the accompanying implications for client organization, parent organization, project organization, and future research. Variables are selected which are found to have the greatest impact on project outcome, and the methodology and analytic techniques to be employed in identification of those variables are discussed.

  8. Determination of Offgassed Products

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A technician at Marshall Space Flight Center's Materials Combustion Research Facility begins the Determination of Offgassed Products Test to determine the identity and quantity of volatile offgassed products from materials and assembled articles. Materials are measured, weighed, and loaded into a clean toxicity chamber (pictured). The chamber is purged with high-purity air and loaded into an oven where it will be held at 120 degrees Fahrenheit (48.9 degrees Celsius) for 72 hours. At the end of the 72-hour period, the chamber is removed and allowed to cool to room temperature. Gas samples are taken from the chamber and analyzed using gas chromatography and mass spectrometry. From this, the quantity of the material that may be used safely in habitable areas of spacecraft is determined. This test also determines whether a flight hardware item may be flown safely in a crew compartment. Everything going into space with the astronauts is tested prior to flight to ensure the health and safety of the crew members.

  9. Determining TOC in Waters

    ERIC Educational Resources Information Center

    Kehoe, Thomas J.

    1977-01-01

    The instrumental method for detecting total organic carbon (TOC) in water samples is detailed. The method's limitations are discussed and certain precautions that must be taken are emphasized. The subject of TOC versus COD and BOD is investigated and TOC is determined to be a valid indication of biological demand. (BT)

  10. Gender determination in populus

    SciTech Connect

    McLetchie, D.N.; Tuskan, G.A.

    1994-12-31

    Gender, the expression of maleness or femaleness, in dioecious plants has been associated with changes in morphology, physiology, ecological position, and commercial importance of several species, including members of the Salicaceae family. Various mechanisms have been proposed to explain the expression of gender in Salicaceae, including sex chromosomes, simple Mendelian genes, quantitative genes, environment, and genotype-by-environment interactions. Published reports would favor a genetic basis for gender. The objective of this study was to identify molecular markers associated with gender in a segregating family of hybrid poplars. Bulked segregant analysis and chi-squared analysis were used to test for the occurrence of sex chromosomes, individual loci, and chromosome ratios (i.e., ploidy levels) as the mechanisms for gender determination. Examination of 2488 PCR based RAPD markers from 1219 primers revealed nine polymorphic bands between male and female bulked samples. However, linkage analysis indicated that none of these markers were significantly associated with gender. Chisquared results for difference in male-to-female ratios between diploid and triploid genotypes also revealed no significant differences. These findings suggest gender is not controlled via sex chromosomes, simple Mendelian loci or ratios of autosome to gender-determining loci. It is possible that gender is determined genetically by regions of the genome not sampled by the tested markers or by a complex of loci operating in an additive threshold manner or in an epistatic manner. It is also possible that gender is determined environmentally at an early zygote stage, canalizing gender expression.

  11. Determination of Fat Content

    NASA Astrophysics Data System (ADS)

    Carpenter, Charles

    The term "lipid" refers to a group of compounds that are sparingly soluble in water, but show variable solubility in a number of organic solvents (e.g., ethyl ether, petroleum ether, acetone, ethanol, methanol, benzene). The lipid content of a food determined by extraction with one solvent may be quite different from the lipid content as determined with another solvent of different polarity. Fat content is determined often by solvent extraction methods (e.g., Soxhlet, Goldfish, Mojonnier), but it also can be determined by nonsolvent wet extraction methods (e.g., Babcock, Gerber), and by instrumental methods that rely on the physical and chemical properties of lipids (e.g., infrared, density, X-ray absorption). The method of choice depends on a variety of factors, including the nature of the sample (e.g., dry versus moist), the purpose of the analysis (e.g., official nutrition labeling or rapid quality control), and instrumentation available (e.g., Babcock uses simple glassware and equipment; infrared requires an expensive instrument).

  12. Determining Haugh Units

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rapidly determining shell egg quality in an objective manner is not an easy task. Candling is most often utilized as a quick method for assessing egg quality in a non-destructive manner, but it is a highly subjective method. As you have experienced this week, it is almost impossible for multiple p...

  13. Waste Determination Equivalency - 12172

    SciTech Connect

    Freeman, Rebecca D.

    2012-07-01

    The Savannah River Site (SRS) is a Department of Energy (DOE) facility encompassing approximately 800 square kilometers near Aiken, South Carolina which began operations in the 1950's with the mission to produce nuclear materials. The SRS contains fifty-one tanks (2 stabilized, 49 yet to be closed) distributed between two liquid radioactive waste storage facilities at SRS containing carbon steel underground tanks with storage capacities ranging from 2,800,000 to 4,900,000 liters. Treatment of the liquid waste from these tanks is essential both to closing older tanks and to maintaining space needed to treat the waste that is eventually vitrified or disposed of onsite. Section 3116 of the Ronald W. Reagan National Defense Authorization Act of Fiscal Year 2005 (NDAA) provides the Secretary of Energy, in consultation with the Nuclear Regulatory Commission (NRC), a methodology to determine that certain waste resulting from prior reprocessing of spent nuclear fuel are not high-level radioactive waste if it can be demonstrated that the waste meets the criteria set forth in Section 3116(a) of the NDAA. The Secretary of Energy, in consultation with the NRC, signed a determination in January 2006, pursuant to Section 3116(a) of the NDAA, for salt waste disposal at the SRS Saltstone Disposal Facility. This determination is based, in part, on the Basis for Section 3116 Determination for Salt Waste Disposal at the Savannah River Site and supporting references, a document that describes the planned methods of liquid waste treatment and the resulting waste streams. The document provides descriptions of the proposed methods for processing salt waste, dividing them into 'Interim Salt Processing' and later processing through the Salt Waste Processing Facility (SWPF). Interim Salt Processing is separated into Deliquification, Dissolution, and Adjustment (DDA) and Actinide Removal Process/Caustic Side Solvent Extraction Unit (ARP/MCU). The Waste Determination was signed by the

  14. Microcalorimetric and SAXS determination of PEO-SDS interactions: the effect of cosolutes formed by ions.

    PubMed

    Barbosa, Aparecida Mageste; Santos, Igor José Boggione; Ferreira, Guilherme Max Dias; da Silva, Maria do Carmo Hespanhol; Teixeira, Alvaro Vianna Novaes de Carvalho; da Silva, Luis Henrique Mendes

    2010-09-23

    The effect of different ionic cosolutes (NaCl, Na(2)SO(4), Li(2)SO(4), NaSCN, Na(2)[Fe(CN)(5)NO], and Na(3)[Co(NO)(6)]) on the interaction between sodium dodecyl sulfate (SDS) and poly(ethylene oxide) (PEO) was examined by small-angle X-ray scattering (SAXS) and isothermal titration calorimetric techniques. The critical aggregation concentration values (cac), the saturation concentration (C(2)), the integral enthalpy change for aggregate formation (ΔH(agg)(int)) and the standard free energy change of micelle adsorption on the macromolecule chain (ΔΔG(agg)) were derived from the calorimetric titration curves. In the presence of 1.00 mmol L(-1) cosolute, no changes in the parameters were observed when compared with those obtained for SDS-PEO interactions in pure water. For NaCl, Na(2)SO(4), Li(2)SO(4), and NaSCN at 10.0 and 100 mmol L(-1), the cosolute presence lowered cac, increased C(2), and the PEO-SDS aggregate became more stable. In the presence of Na(2)[Fe(CN)(5)NO], the calorimetric titration curves changed drastically, showing a possible reduction in the PEO-SDS degree of interaction, possibility disrupting the formed nanostructure; however, the SAXS data confirmed, independent of the small energy observed, the presence of aggregates adsorbed on the polymer chain. PMID:20806942

  15. Determination of nickel-63

    SciTech Connect

    Poletiko, C.

    1988-01-01

    The research of activation products in the environment is often centered on cobalt-60 or other gamma emitters, since pure beta emitters require time consuming separations to be counted. However, some beta emitters must be checked because they have a build up in the environment, leading to potential hazards. Among these nuclides, there is nickel-63 which is a pure, soft beta emitter (67 keV) with a long half-life (100 years). A chemical separation, providing good results, was developed. Such a separation is based upon nickel carrier addition in the sample than DMG complex formation and isolation; after elimination of solvent. DMG complex is destroyed. Chemical yield is determined by flame atomic absorption measurement and nickel-63 counted by liquid scintillation. The described procedure allows the determination of low-level activities in different samples (soils, effluents, etc.). Detection limits are close to 0.1 Bq per sample.

  16. Stepwise shockwave velocity determinator

    NASA Technical Reports Server (NTRS)

    Roth, Timothy E.; Beeson, Harold

    1992-01-01

    To provide an uncomplicated and inexpensive method for measuring the far-field velocity of a surface shockwave produced by an explosion, a stepwise shockwave velocity determinator (SSVD) was developed. The velocity determinator is constructed of readily available materials and works on the principle of breaking discrete sensors composed of aluminum foil contacts. The discrete sensors have an average breaking threshold of approximately 7 kPa. An incremental output step of 250 mV is created with each foil contact breakage and is logged by analog-to-digital instrumentation. Velocity data obtained from the SSVD is within approximately 11 percent of the calculated surface shockwave velocity of a muzzle blast from a 30.06 rifle.

  17. Determination of balloon drag

    NASA Technical Reports Server (NTRS)

    Conrad, George R.; Robbins, Edward J.

    1991-01-01

    The evolution of an empirical drag relationship that has stimulated rethinking regarding the physics of balloon drag phenomena is discussed. Combined parasitic drag from all sources in the balloon system are estimated to constitute less than 10 percent of the total system drag. It is shown that the difference between flight-determined drag coefficients and those based on the spherical assumption should be related to the square of the Froude number.

  18. REDUCED PROTECTIVE CLOTHING DETERMINATIONS

    SciTech Connect

    BROWN, R.L.

    2003-06-13

    This technical basis document defines conditions where reduced protective clothing can be allowed, defines reduced protective clothing, and documents the regulatory review that determines the process is compliant with the Tank Farm Radiological Control Manual (TFRCM) and Title 10, Part 835, of the Code of Federal Regulations (10CFR835). The criteria, standards, and requirements contained in this document apply only to Tank Farm Contractor (TFC) facilities.

  19. Gender determination using cheiloscopy

    PubMed Central

    Padmavathi, B. N.; Makkad, Ramanpal Singh; Rajan, S. Y.; Kolli, Gopi Krishna

    2013-01-01

    Background: Although lip prints have been used as an evidence for human identification in forensic science, there exists a doubt about its role in gender determination. Aims: The present study was designed for documenting common patterns, as well as their variation in the study population, with objective of evaluating uniqueness of the lip print pattern among the study population, as well as to evaluate the possibility of gender determination. Study Design: Two hundred and thirty five lip prints were collected from volunteers among out patients of Darshan Dental College and Hospital, as well as community dental care camps of rural areas around Udaipur. Materials and Methods: Lip prints were recorded with transparent overlay and transferred on to a bond paper. It was then photographed using a Canon EOS 55OD 16 mega pixel digital camera. Software Picasa 3.6 and Microsoft Picture Manager were used to digitally enhance the quality and magnify the image bearing the groove pattern. Lip prints were later analyzed. Statistical Analysis: Pearson chi square test was adopted for statistical analysis and probability (P value) was calculated. Conclusion: In our study, none of the lip prints were identical, thus confirming the role of lip prints in individual identification. Dots, reticular and complex patterns were significant in gender determination. PMID:24255561

  20. Determination of epsomite-hexahydrite equilibria by the humidity-buffer technique at 0.1 MPa with implications for phase equilibria in the system MgSO4-H2O.

    USGS Publications Warehouse

    Chou, I.-Ming; Seal, R.R., 2nd.

    2003-01-01

    Epsomite (MgSO(4).7H(2)O) and hexahydrite (MgSO(4).6H(2)O) are common minerals found in marine evaporite deposits, in saline lakes as precipitates, in weathering zones of coal and metallic deposits, in some soils and their efflorescences, and possibly on the surface of Europa as evaporite deposits. Thermodynamic properties of these two minerals reported in the literature are in poor agreement. In this study, epsomite-hexahydrite equilibria were determined along four humidity-buffer curves at 0.1 MPa and between 25 and 45 degrees C. Results obtained for the reaction epsomite = hexahydrite + H(2)O, as demonstrated by very tight reversals along each humidity buffer, can be represented by ln K(+/- 0.012) = 20.001 - 7182.07/T, where K is the equilibrium constant, and T is temperature in Kelvin. The derived standard Gibbs free energy of reaction is 10.13 +/- 0.07 kJ/mol, which is essentially the same value as that calculated from vapor pressure measurements reported in the literature. However, this value is at least 0.8 kJ/mol lower than those calculated from the data derived mostly from calorimetric measurements.

  1. Determination of the Structure and Catalytic Mechanism of Sorghum bicolor Caffeic Acid O-Methyltransferase and the Structural Impact of Three brown midrib12 Mutations.

    PubMed

    Green, Abigail R; Lewis, Kevin M; Barr, John T; Jones, Jeffrey P; Lu, Fachuang; Ralph, John; Vermerris, Wilfred; Sattler, Scott E; Kang, ChulHee

    2014-06-19

    Using S-adenosyl-methionine as the methyl donor, caffeic acid O-methyltransferase from sorghum (Sorghum bicolor; SbCOMT) methylates the 5-hydroxyl group of its preferred substrate, 5-hydroxyconiferaldehyde. In order to determine the mechanism of SbCOMT and understand the observed reduction in the lignin syringyl-to-guaiacyl ratio of three brown midrib12 mutants that carry COMT gene missense mutations, we determined the apo-form and S-adenosyl-methionine binary complex SbCOMT crystal structures and established the ternary complex structure with 5-hydroxyconiferaldehyde by molecular modeling. These structures revealed many features shared with monocot ryegrass (Lolium perenne) and dicot alfalfa (Medicago sativa) COMTs. SbCOMT steady-state kinetic and calorimetric data suggest a random bi-bi mechanism. Based on our structural, kinetic, and thermodynamic results, we propose that the observed reactivity hierarchy among 4,5-dihydroxy-3-methoxycinnamyl (and 3,4-dihydroxycinnamyl) aldehyde, alcohol, and acid substrates arises from the ability of the aldehyde to stabilize the anionic intermediate that results from deprotonation of the 5-hydroxyl group by histidine-267. Additionally, despite the presence of other phenylpropanoid substrates in vivo, sinapaldehyde is the preferential product, as demonstrated by its low Km for 5-hydroxyconiferaldehyde. Unlike its acid and alcohol substrates, the aldehydes exhibit product inhibition, and we propose that this is due to nonproductive binding of the S-cis-form of the aldehydes inhibiting productive binding of the S-trans-form. The S-cis-aldehydes most likely act only as inhibitors, because the high rotational energy barrier around the 2-propenyl bond prevents S-trans-conversion, unlike alcohol substrates, whose low 2-propenyl bond rotational energy barrier enables rapid S-cis/S-trans-interconversion. PMID:24948836

  2. HEU age determination

    SciTech Connect

    Moorthy, A.R.; Kato, W.Y.

    1994-12-31

    A criteria that a sample of highly enriched uranium (HEU) had come from a weapons stockpile and not newly produced in an enrichment plant is to show that the HEU had been produced a significant time in the past. The time since the HEU has produced in an enrichment plant is defined as the age of the HEU in this paper. The HEU age is determined by measuring quantitatively the daughter products {sup 230}Th and {sup 231}Pa of {sup 234}U and {sup 235}U, respectively, by first chemical separation of the thorium and protactinium and then conducting alpha spectrometry of the daughter products.

  3. Mass determination of neutrinos

    NASA Technical Reports Server (NTRS)

    Chiu, Hong-Yee

    1988-01-01

    A time-energy correlation method has been developed to determine the signature of a nonzero neutrino mass in a small sample of neutrinos detected from a distant source. The method is applied to the Kamiokande II (Hirata et al., 1987) and IMB (Bionta et al., 1987) observations of neutrino bursts from SN 1987A. Using the Kamiokande II data, the neutrino rest mass is estimated at 2.8 + 2.0, - 1.4 eV and the initial neutrino pulse is found to be less than 0.3 sec full width, followed by an emission tail lasting at least 10 sec.

  4. The Determination of Downwash

    NASA Technical Reports Server (NTRS)

    Diehl, Walter S

    1921-01-01

    It is obvious that, in accordance with Newton's second law, the lift on an aerofoil must be equal to the vertical momentum communicated per second to the air mass affected. Consequently a lifting aerofoil in flight is trailed by a wash which has a definite inclination corresponding to the factors producing the lift. It is thought that sufficient data, theoretical and experimental, are now available for a complete determination of this wash with respect to the variation of its angle of inclination to the originating aerofoil and with respect to the law which governs its decay in space.

  5. Determining residential firewood consumption

    NASA Astrophysics Data System (ADS)

    Marsinko, Allan P. C.; Phillips, Douglas R.; Cordell, H. Ken

    1984-07-01

    Household firewood use has become increasingly popular in the United States over the past few years. Significant problems remain in estimating firewood consumption. Methods of determining the amount of wood consumed vary from state to state. Units used for measuring firewood vary, but the cord remains the researcher's favorite. Factors used for converting other units, such as pickup truck loads to cords also vary. People who do not use firewood are less likely to respond to mailed surveys, resulting in potential overestimates of statewide consumption. This paper identifies some problems associated with estimating household firewood consumption and recommends methods of dealing with them.

  6. Satellite altitude determination uncertainties

    NASA Technical Reports Server (NTRS)

    Siry, J. W.

    1972-01-01

    Satellite altitude determination uncertainties will be discussed from the standpoint of the GEOS-C satellite, from the longer range viewpoint afforded by the Geopause concept. Data are focused on methods for short-arc tracking which are essentially geometric in nature. One uses combinations of lasers and collocated cameras. The other method relies only on lasers, using three or more to obtain the position fix. Two typical locales are looked at, the Caribbean area, and a region associated with tracking sites at Goddard, Bermuda and Canada which encompasses a portion of the Gulf Stream in which meanders develop.

  7. Determination of radar MTF

    SciTech Connect

    Chambers, D.

    1994-11-15

    The ultimate goal of the Current Meter Array (CMA) is to be able to compare the current patterns detected with the array with radar images of the water surface. The internal wave current patterns modulate the waves on the water surface giving a detectable modulation of the radar cross-section (RCS). The function relating the RCS modulations to the current patterns is the Modulation Transfer Function (MTF). By comparing radar images directly with co-located CMA measurements the MTF can be determined. In this talk radar images and CMA measurements from a recent experiment at Loch Linnhe, Scotland, will be used to make the first direct determination of MTF for an X and S band radar at low grazing angles. The technical problems associated with comparing radar images to CMA data will be explained and the solution method discussed. The results suggest the both current and strain rate contribute equally to the radar modulation for X band. For S band, the strain rate contributes more than the current. The magnitude of the MTF and the RCS modulations are consistent with previous estimates when the wind is blowing perpendicular to the radar look direction.

  8. Determination of Survivable Fires

    NASA Technical Reports Server (NTRS)

    Dietrich, D. L.; Niehaus, J. E.; Ruff, G. A.; Urban, D. L.; Takahashi, F.; Easton, J. W.; Abbott, A. A.; Graf, J. C.

    2012-01-01

    At NASA, there exists no standardized design or testing protocol for spacecraft fire suppression systems (either handheld or total flooding designs). An extinguisher's efficacy in safely suppressing any reasonable or conceivable fire is the primary benchmark. That concept, however, leads to the question of what a reasonable or conceivable fire is. While there exists the temptation to over-size' the fire extinguisher, weight and volume considerations on spacecraft will always (justifiably) push for the minimum size extinguisher required. This paper attempts to address the question of extinguisher size by examining how large a fire a crew member could successfully survive and extinguish in the confines of a spacecraft. The hazards to the crew and equipment during an accidental fire include excessive pressure rise resulting in a catastrophic rupture of the vehicle skin, excessive temperatures that burn or incapacitate the crew (due to hyperthermia), carbon dioxide build-up or other accumulation of other combustion products (e.g. carbon monoxide). Estimates of these quantities are determined as a function of fire size and mass of material burned. This then becomes the basis for determining the maximum size of a target fire for future fire extinguisher testing.

  9. Satellite orbit determination

    NASA Technical Reports Server (NTRS)

    Jordan, J. F.; Boggs, D. H.; Born, G. H.; Christensen, E. J.; Ferrari, A. J.; Green, D. W.; Hylkema, R. K.; Mohan, S. N.; Reinbold, S. J.; Sievers, G. L.

    1973-01-01

    A historic account of the activities of the Satellite OD Group during the MM'71 mission is given along with an assessment of the accuracy of the determined orbit of the Mariner 9 spacecraft. Preflight study results are reviewed, and the major error sources described. Tracking and data fitting strategy actually used in the real time operations is itemized, and Deep Space Network data available for orbit fitting during the mission and the auxiliary information used by the navigation team are described. A detailed orbit fitting history of the first four revolutions of the satellite orbit of Mariner 9 is presented, with emphasis on the convergence problems and the delivered solution for the first orbit trim maneuver. Also included are a solution accuracy summary, the history of the spacecraft orbit osculating elements, the results of verifying the radio solutions with TV imaging data, and a summary of the normal points generated for the relativity experiment.

  10. Determination of Cytotoxicity.

    PubMed

    2016-01-01

    Cytotoxicity assays are used for drug screening and cytotoxicity tests of chemicals. Nowadays, various reagents are used for cell viability detection. They are based on various cell functions such as enzyme activity, cell membrane permeability, cell adherence, ATP production, co-enzyme production and nucleotide uptake activity. Many have established methods such as colony formation method, crystal violet method, tritium-labelled thymidine uptake method, MTT and WST methods, which are used for counting the number of live cells. Moreover, trypan blue is a widely used assay for staining dead cells. In this method, cell viability must be determined by counting the unstained cells with a microscope or other instruments. This chapter is a collection of all these methods to be followed by researchers in a sequential manner. PMID:26939283

  11. Satellite altitude determination uncertainties

    NASA Technical Reports Server (NTRS)

    Siry, J. W.

    1971-01-01

    Satellite altitude determination uncertainties are discussed from the standpoint of the GEOS-C satellite. GEOS-C will be tracked by a number of the conventional satellite tracking systems, as well as by two advanced systems; a satellite-to-satellite tracking system and lasers capable of decimeter accuracies which are being developed in connection with the Goddard Earth and Ocean Dynamics Applications program. The discussion is organized in terms of a specific type of GEOS-C orbit which would satisfy a number of scientific objectives including the study of the gravitational field by means of both the altimeter and the satellite-to-satellite tracking system, studies of tides, and the Gulf Stream meanders.

  12. Determinants of genetic diversity.

    PubMed

    Ellegren, Hans; Galtier, Nicolas

    2016-07-01

    Genetic polymorphism varies among species and within genomes, and has important implications for the evolution and conservation of species. The determinants of this variation have been poorly understood, but population genomic data from a wide range of organisms now make it possible to delineate the underlying evolutionary processes, notably how variation in the effective population size (Ne) governs genetic diversity. Comparative population genomics is on its way to providing a solution to 'Lewontin's paradox' - the discrepancy between the many orders of magnitude of variation in population size and the much narrower distribution of diversity levels. It seems that linked selection plays an important part both in the overall genetic diversity of a species and in the variation in diversity within the genome. Genetic diversity also seems to be predictable from the life history of a species. PMID:27265362

  13. Automatic Bayesian polarity determination

    NASA Astrophysics Data System (ADS)

    Pugh, D. J.; White, R. S.; Christie, P. A. F.

    2016-07-01

    The polarity of the first motion of a seismic signal from an earthquake is an important constraint in earthquake source inversion. Microseismic events often have low signal-to-noise ratios, which may lead to difficulties estimating the correct first-motion polarities of the arrivals. This paper describes a probabilistic approach to polarity picking that can be both automated and combined with manual picking. This approach includes a quantitative estimate of the uncertainty of the polarity, improving calculation of the polarity probability density function for source inversion. It is sufficiently fast to be incorporated into an automatic processing workflow. When used in source inversion, the results are consistent with those from manual observations. In some cases, they produce a clearer constraint on the range of high-probability source mechanisms, and are better constrained than source mechanisms determined using a uniform probability of an incorrect polarity pick.

  14. Complexometric Determination of Calcium

    NASA Astrophysics Data System (ADS)

    Nielsen, S. Suzanne

    Ethylenediaminetetraacetate (EDTA) complexes with numerous mineral ions, including calcium and magnesium. This reaction can be used to determine the amount of these minerals in a sample by a complexometric titration. Endpoints in the titration are detected using indicators that change color when they complex with mineral ions. Calmagite and eriochrome black T (EBT) are such indicators that change from blue to pink when they complex with calcium and magnesium. In the titration of a mineral-containing solution with EDTA, the solution turns from pink to blue at the endpoint with either indicator. The pH affects a complexometric EDTA titration in several ways, and must be carefully controlled. A major application of EDTA titration is testing the hardness of water, for which the method described is an official one (Standard Methods for the Examination of Water and Wastewater, Method 2340C; AOAC Method 920.196).

  15. Automatic Bayesian polarity determination

    NASA Astrophysics Data System (ADS)

    Pugh, D. J.; White, R. S.; Christie, P. A. F.

    2016-04-01

    The polarity of the first motion of a seismic signal from an earthquake is an important constraint in earthquake source inversion. Microseismic events often have low signal-to-noise ratios, which may lead to difficulties estimating the correct first-motion polarities of the arrivals. This paper describes a probabilistic approach to polarity picking that can be both automated and combined with manual picking. This approach includes a quantitative estimate of the uncertainty of the polarity, improving calculation of the polarity probability density function for source inversion. It is sufficiently fast to be incorporated into an automatic processing workflow. When used in source inversion, the results are consistent with those from manual observations. In some cases, they produce a clearer constraint on the range of high-probability source mechanims, and are better constrained than source mechanisms determined using a uniform probability of an incorrect polarity pick.

  16. Tracer for circulation determinations

    SciTech Connect

    Moore, H.; Santos, S.; Wysong, R. D.

    1985-03-19

    An improved tracer particle is described comprising an ion exchange core having a polymer coating thereon, the coated ion exchange core having a reaction site capable of reacting with a compound containing an oxirane group, said coated ion exchange core having been treated with a compound containing an oxirane group to react with said coated ion exchange core causing an increase in mass of the tracer particle. Preferably, the ion exchange core is labelled with a radionuclide. These particles have improved characteristics including improved stability against leaching and improved handling properties. Such particles are useful in circulatory determinations involving the injection of the particles as a suspension in a physiologically acceptable carrier or medium into the circulatory system of animals.

  17. Orbit Determination Toolbox

    NASA Technical Reports Server (NTRS)

    Carpenter, James R.; Berry, Kevin; Gregpru. Late; Speckman, Keith; Hur-Diaz, Sun; Surka, Derek; Gaylor, Dave

    2010-01-01

    The Orbit Determination Toolbox is an orbit determination (OD) analysis tool based on MATLAB and Java that provides a flexible way to do early mission analysis. The toolbox is primarily intended for advanced mission analysis such as might be performed in concept exploration, proposal, early design phase, or rapid design center environments. The emphasis is on flexibility, but it has enough fidelity to produce credible results. Insight into all flight dynamics source code is provided. MATLAB is the primary user interface and is used for piecing together measurement and dynamic models. The Java Astrodynamics Toolbox is used as an engine for things that might be slow or inefficient in MATLAB, such as high-fidelity trajectory propagation, lunar and planetary ephemeris look-ups, precession, nutation, polar motion calculations, ephemeris file parsing, and the like. The primary analysis functions are sequential filter/smoother and batch least-squares commands that incorporate Monte-Carlo data simulation, linear covariance analysis, measurement processing, and plotting capabilities at the generic level. These functions have a user interface that is based on that of the MATLAB ODE suite. To perform a specific analysis, users write MATLAB functions that implement truth and design system models. The user provides his or her models as inputs to the filter commands. The software provides a capability to publish and subscribe to a software bus that is compliant with the NASA Goddard Mission Services Evolution Center (GMSEC) standards, to exchange data with other flight dynamics tools to simplify the flight dynamics design cycle. Using the publish and subscribe approach allows for analysts in a rapid design center environment to seamlessly incorporate changes in spacecraft and mission design into navigation analysis and vice versa.

  18. Significant Radionuclides Determination

    SciTech Connect

    Jo A. Ziegler

    2001-07-31

    The purpose of this calculation is to identify radionuclides that are significant to offsite doses from potential preclosure events for spent nuclear fuel (SNF) and high-level radioactive waste expected to be received at the potential Monitored Geologic Repository (MGR). In this calculation, high-level radioactive waste is included in references to DOE SNF. A previous document, ''DOE SNF DBE Offsite Dose Calculations'' (CRWMS M&O 1999b), calculated the source terms and offsite doses for Department of Energy (DOE) and Naval SNF for use in design basis event analyses. This calculation reproduces only DOE SNF work (i.e., no naval SNF work is included in this calculation) created in ''DOE SNF DBE Offsite Dose Calculations'' and expands the calculation to include DOE SNF expected to produce a high dose consequence (even though the quantity of the SNF is expected to be small) and SNF owned by commercial nuclear power producers. The calculation does not address any specific off-normal/DBE event scenarios for receiving, handling, or packaging of SNF. The results of this calculation are developed for comparative analysis to establish the important radionuclides and do not represent the final source terms to be used for license application. This calculation will be used as input to preclosure safety analyses and is performed in accordance with procedure AP-3.12Q, ''Calculations'', and is subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (DOE 2000) as determined by the activity evaluation contained in ''Technical Work Plan for: Preclosure Safety Analysis, TWP-MGR-SE-000010'' (CRWMS M&O 2000b) in accordance with procedure AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities''.

  19. Determining satellite close approaches

    NASA Astrophysics Data System (ADS)

    Alfano, Salvatore; Negron, David, Jr.

    1993-06-01

    This paper presents a numerical method to evaluate close approaches of two satellites. The algorithm is based on a space curve modeling technique originally developed by Overhauser, presented here as an independent derivation. The method to determine minimum spacing between two space objects is based on creating a relative distance waveform, delta(t), versus time. The waveform is produced from either uniform or arbitrarily spaced data points, from which intervals of close approach are obtained by extracting the real roots of a localized cubic polynomial. This method is free of both transcendental equations and the computation of acceleration terms of the two objects of interest. For this study, a close approach truth table is constructed using a 0.1 second sequential step along the orbits, then differencing the two position vectors. The close approach entrance and exit times for an ellipsoidal quadric surface are then located using a piecewise linear interpolator, and serve as a benchmark for comparison. The simulation results show this algorithm produces encounter times almost identical to those in the truth table, with a 99.84 percent reduction in computer runtime. The results, created from real orbital data, include solution sets for three operational uses of close-approach logic. For this study, satellite orbital motion is modeled using first-order secular perturbations caused by mass anomalies.

  20. Age determination of raccoons

    USGS Publications Warehouse

    Grau, G.A.; Sanderson, G.C.; Rogers, J.P.

    1970-01-01

    Age criteria, based on 61 skulls and eye lenses from 103 known-age captives, are described for separating raccoons (Procyon lotor) into eight age-classes as follows: young-of-the-year, 1, 2, 3, 4, 5, 6-7, > 7 years. Criteria studied were eye lens nitrogen, cranial suture closure, tooth wear and incisor cementum layers. Lens nitrogen increased rapidly up to 12 months of age, but at much reduced rate thereafter. Total lens nitrogen was useful only in separating young-of-the-year from adults. The closure sequence for five cranial sutures accurately divided the total known-age sample of males into seven groups, and the adults into five groups. The tooth wear criteria divided the known-age sample into five relative age groups, but aging of individuals by this method was inaccurate. Histological sectioning of known-age teeth was the best method of observing layering in the cementum tissue. The technique of basing estimation of age on cementum ring counts, although subjective, was accurate for aging individuals through their fourth year but tended to underestimate the age of animals over 4 years old. However, suture closure or tooth wear can be used to identify males over 4 years old. In field studies, technical difficulties limit the utility of age estimation by cementum layers. Maximum root thickness of the lower canine was accurate in determining the sex of individuals from 5 months to ,at least 48 months of age.

  1. Cryogenic Laser Calorimetry for Impurity Analysis

    NASA Technical Reports Server (NTRS)

    Swimm, R. T.

    1985-01-01

    The results of a one-year effort to determine the applicability of laser-calorimetric spectroscopy to the study of deep-level impurities in silicon are presented. Critical considerations for impurity analysis by laser-calorimetric spectroscopy are discussed, the design and performance of a cryogenic laser calorimeter is described, and measurements of background absorption in high-purity silicon are presented.

  2. Determination of the cis-trans isomerization barriers of L-alanyl-L-proline in aqueous solutions and at water/hydrophobic interfaces by on-line temperature-jump relaxation HPLC and dynamic on-column reaction HPLC.

    PubMed

    Shibukawa, Masami; Miyake, Ayaka; Eda, Sayaka; Saito, Shingo

    2015-09-15

    Proline cis-trans isomerization is known to play a key role in the rate-determining steps of protein folding. It is thus very important to understand the influence of environments, not only bulk solutions but also microenvironments such as interfaces, on the isomerization reaction of proline peptides. Here we present two HPLC methods for measurements of kinetic and equilibrium parameters for the isomerization reactions in bulk solutions and at liquid/solid interfaces. On-line temperature-jump relaxation HPLC (T-jump HPLC) allows the determination of forward and reverse rate constants of the isomerization in a bulk solution by monitoring the whole time course of conversion of pure isomers from both sides of the reaction, in contrast to other HPLC and capillary zone electrophoresis as well as spectrometric and calorimetric methods, which use a mixture of the isomers. We can then determine cis-trans isomerization barriers of the peptide at liquid/solid interfaces from the kinetic data obtained by dynamic on-column reaction HPLC and T-jump HPLC. We observed that the interconversion around the peptide bond for l-alanyl-l-proline (Ala-Pro) in water is accelerated at the surfaces of an alkyl-bonded silica and a poly(styrene-divinylbenzene) copolymer resin, and this is caused by a remarkable decrease in the enthalpy of activation. The molecular structures of the cis and trans forms of Ala-Pro estimated by quantum mechanics calculation reveal that an equilibrium shift toward the cis form as well as the rapid isomerization of Ala-Pro at the water/hydrophobic interfaces can be attributed to the lower polarity of the interfacial water at the surfaces of the hydrophobic materials compared to that of bulk water. PMID:26320351

  3. DETERMINATION OF CALORIES BY NIR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although NIR spectroscopy has been used to determine energy content of feeds, little is known about the capability of near-infrared (NIR) spectroscopy for the determination of available energy in foods for human consumption. Recent studies have been conducted to determine the utilizable energy in p...

  4. Determinants for grading Malaysian rice

    NASA Astrophysics Data System (ADS)

    ChePa, Noraziah; Yusoff, Nooraini; Ahmad, Norhayati

    2016-08-01

    Due to un-uniformity of rice grading practices in Malaysia, zones which actively producing rice in Malaysia are using their own way of grading rice. Rice grading is important in determining rice quality and its subsequent price in the market. It is an important process applied in the rice production industry with the purpose of ensuring that the rice produced for the market meets the quality requirements of consumer. Two important aspects that need to be considered in determining rice grades are grading technique and determinants to be used for grading (usually referred as rice attributes). This article proposes the list of determinants to be used in grading Malaysian rice. Determinants were explored through combination of extensive literature review and series of interview with the domain experts and practitioners. The proposed determinants are believed to be beneficial to BERNAS in improving the current Malaysian rice grading process.

  5. New determination equation for visibility

    SciTech Connect

    Fang Qiwan; Rao Jionghui; Ying Zhixiang; Tang Haijun; Jiang Chuanfu

    1996-12-31

    Range is an important tactical hard index in designing and manufacturing military laser rangefinders. But in practice it is also a soft index which is influenced by target characteristic and atmospheric visibility. In this article the problems in the range index are analyzed. The way to determine visibility is put forward. Extinction determination equation for visibility is derived. And it is applied in practice, which verifies the determination equation is functional and effective.

  6. Self-Determination. Feature Issue.

    ERIC Educational Resources Information Center

    IMPACT, 1994

    1994-01-01

    This theme issue explores the relevance of self-determination for persons with developmental disabilities across the life span, ways in which it is or can be expressed, and obstacles to its exercise. The articles show the futility of enhancing self-determination by teaching choice-making skills if environments offer no opportunities to exercise…

  7. The Resurgence of Biological Determinism.

    ERIC Educational Resources Information Center

    Segal, Elizabeth A.; Kilty, Keith M.

    1998-01-01

    Addresses two areas where science has been and still is used to justify policies and attitudes that are discriminatory and oppressive: homosexuality and alcoholism. This article analyzes the debate over whether these correlations are biologically or socially determined. Of particular concern is the potential impact of biological determinism on the…

  8. Precise Orbit Determination for ALOS

    NASA Technical Reports Server (NTRS)

    Nakamura, Ryo; Nakamura, Shinichi; Kudo, Nobuo; Katagiri, Seiji

    2007-01-01

    The Advanced Land Observing Satellite (ALOS) has been developed to contribute to the fields of mapping, precise regional land coverage observation, disaster monitoring, and resource surveying. Because the mounted sensors need high geometrical accuracy, precise orbit determination for ALOS is essential for satisfying the mission objectives. So ALOS mounts a GPS receiver and a Laser Reflector (LR) for Satellite Laser Ranging (SLR). This paper deals with the precise orbit determination experiments for ALOS using Global and High Accuracy Trajectory determination System (GUTS) and the evaluation of the orbit determination accuracy by SLR data. The results show that, even though the GPS receiver loses lock of GPS signals more frequently than expected, GPS-based orbit is consistent with SLR-based orbit. And considering the 1 sigma error, orbit determination accuracy of a few decimeters (peak-to-peak) was achieved.

  9. Sex determination: the amphibian models.

    PubMed

    Eggert, Christophe

    2004-01-01

    We review and discuss current knowledge about sex determination in amphibians. The astonishing wide variety of mechanisms of genotypic sex determination is presented and discussed in an evolutionary context. We recall the natural occurrence of transitory juvenile hermaphroditism in some species. Our present knowledge of the mechanisms of sex determination in amphibians is compared to that in mammals. The influence of epigenetic factors, and especially temperature is highlighted. In amphibians, the influence of temperature on sexual differentiation, that can prevail over genotypic sex determination, remains poorly considered in publications. We suggest that studies on genetic and epigenetic factors of gonadal sex differentiation in amphibians could provide substantial information on the evolutionary process of sex determination mechanisms in current living vertebrates. PMID:15762298

  10. Method of determining glass durability

    DOEpatents

    Jantzen, C.M.; Pickett, J.B.; Brown, K.G.; Edwards, T.B.

    1998-12-08

    A process is described for determining one or more leachate concentrations of one or more components of a glass composition in an aqueous solution of the glass composition by identifying the components of the glass composition, including associated oxides, determining a preliminary glass dissolution estimator, {Delta}G{sub p}, based upon the free energies of hydration for the component reactant species, determining an accelerated glass dissolution function, {Delta}G{sub a}, based upon the free energy associated with weak acid dissociation, {Delta}G{sub a}{sup WA}, and accelerated matrix dissolution at high pH, {Delta}G{sub a}{sup SB} associated with solution strong base formation, and determining a final hydration free energy, {Delta}G{sub f}. This final hydration free energy is then used to determine leachate concentrations for elements of interest using a regression analysis and the formula log{sub 10}(N C{sub i}(g/L))=a{sub i} + b{sub i}{Delta}G{sub f}. The present invention also includes a method to determine whether a particular glass to be produced will be homogeneous or phase separated. The present invention is also directed to methods of monitoring and controlling processes for making glass using these determinations to modify the feedstock materials until a desired glass durability and homogeneity is obtained. 4 figs.

  11. Method of determining glass durability

    DOEpatents

    Jantzen, Carol Maryanne; Pickett, John Butler; Brown, Kevin George; Edwards, Thomas Barry

    1998-01-01

    A process for determining one or more leachate concentrations of one or more components of a glass composition in an aqueous solution of the glass composition by identifying the components of the glass composition, including associated oxides, determining a preliminary glass dissolution estimator, .DELTA.G.sub.p, based upon the free energies of hydration for the component reactant species, determining an accelerated glass dissolution function, .DELTA.G.sub.a, based upon the free energy associated with weak acid dissociation, .DELTA.G.sub.a.sup.WA, and accelerated matrix dissolution at high pH, .DELTA.G.sub.a.sup.SB associated with solution strong base formation, and determining a final hydration free energy, .DELTA.G.sub.f. This final hydration free energy is then used to determine leachate concentrations for elements of interest using a regression analysis and the formula log.sub.10 (N C.sub.i (g/L))=a.sub.i +b.sub.i .DELTA.G.sub.f. The present invention also includes a method to determine whether a particular glass to be produced will be homogeneous or phase separated. The present invention is also directed to methods of monitoring and controlling processes for making glass using these determinations to modify the feedstock materials until a desired glass durability and homogeneity is obtained.

  12. Evans function and Fredholm determinants

    PubMed Central

    Karambal, Issa; Malham, Simon J. A.

    2015-01-01

    We explore the relationship between the Evans function, transmission coefficient and Fredholm determinant for systems of first-order linear differential operators on the real line. The applications we have in mind include linear stability problems associated with travelling wave solutions to nonlinear partial differential equations, for example reaction–diffusion or solitary wave equations. The Evans function and transmission coefficient, which are both finite determinants, are natural tools for both analytic and numerical determination of eigenvalues of such linear operators. However, inverting the eigenvalue problem by the free-state operator generates a natural linear integral eigenvalue problem whose solvability is determined through the corresponding infinite Fredholm determinant. The relationship between all three determinants has received a lot of recent attention. We focus on the case when the underlying Fredholm operator is a trace class perturbation of the identity. Our new results include (i) clarification of the sense in which the Evans function and transmission coefficient are equivalent and (ii) proof of the equivalence of the transmission coefficient and Fredholm determinant, in particular in the case of distinct far fields. PMID:25663806

  13. Erroneous theories of sex determination.

    PubMed Central

    Mittwoch, U

    1985-01-01

    Throughout the major part of history, theories of sex determination had to be formulated in the absence of knowledge of ova and spermatozoa. The most persistent theory postulated that males are associated with the right parental side and females with the left side. At the end of the 19th century, sex was thought to be determined by nutrition. Recent findings regarding bilateral asymmetry in human hermaphrodites and of temperature dependent sex determination in reptiles may restore a small degree of credibility to certain theories predating the discovery of sex chromosomes. Images PMID:3892005

  14. Mars Science Laboratory Orbit Determination

    NASA Technical Reports Server (NTRS)

    Kruizinga, Gerhard L.; Gustafson, Eric D.; Thompson, Paul F.; Jefferson, David C.; Martin-Mur, Tomas J.; Mottinger, Neil A.; Pelletier, Frederic J.; Ryne, Mark S.

    2012-01-01

    This paper describes the orbit determination process, results and filter strategies used by the Mars Science Laboratory Navigation Team during cruise from Earth to Mars. The new atmospheric entry guidance system resulted in an orbit determination paradigm shift during final approach when compared to previous Mars lander missions. The evolving orbit determination filter strategies during cruise are presented. Furthermore, results of calibration activities of dynamical models are presented. The atmospheric entry interface trajectory knowledge was significantly better than the original requirements, which enabled the very precise landing in Gale Crater.

  15. Teacher Compensation and Its Determinants

    ERIC Educational Resources Information Center

    Reiter, Herbert D.

    1974-01-01

    Examines the relationship among environmental influences, per pupil expenditures, and teacher salaries and debates the question whether collective negotiation or environmental influences are the prime determinant of teacher salaries. (Author/DN)

  16. Step 4: NCI Funding Determinations

    Cancer.gov

    Funding determinations are made around Oct. 1 each federal fiscal year. These decisions take into account several factors, including Congressional mandates, new scientific opportunities and program priorities when deciding which grants receive funding.

  17. Determination of plutonium metal origins

    SciTech Connect

    Moody, K.J.

    1995-02-01

    Forensic signatures are present in any Pu sample that can determine the sample`s origin: isotopic ratio of Pu, progeny species that grow into the sample, and contaminant species left over from incomplete purification of the Pu in fuel reprocessing. In the context of intelligence information, this can result in attribution of responsibility for the product of clandestine proliferant operations or material smuggled from existing stockpiles. A list of signature elements and what can be determined from them have been developed. Work needs to be done in converting concentrations of signature species into a quantitative forensic analysis, particularly in regard to reactor performance, but this should require only a small effort. A radiochemical analysis scheme has been developed for measuring these nuclides; more work is needed, particularly for determining fission product concentrations. A sample of Pu metal has been analyzed and several parameters determined that are strong indicators of its point of origin.

  18. Gender determination of avian embryo

    DOEpatents

    Daum, Keith A.; Atkinson, David A.

    2002-01-01

    Disclosed is a method for gender determination of avian embryos. During the embryo incubation process, the outer hard shells of eggs are drilled and samples of allantoic fluid are removed. The allantoic fluids are directly introduced into an ion mobility spectrometer (IMS) for analysis. The resulting spectra contain the relevant marker peaks in the positive or negative mode which correlate with unique mobilities which are sex-specific. This way, the gender of the embryo can be determined.

  19. Determination of zirconium in steels.

    PubMed

    Iyer, C S; Asari, T P

    1989-03-01

    The determination of zirconium in the range 0.01-0.20% is required for some special alloy steels. A method has been developed, based on initial removal of iron as its chloro-complex by extraction with methyl isobutyl ketone, followed by further extraction after addition of potassium thiocyanate, and determination of the zirconium left in the aqueous phase, with Arsenazo III. The absorbance is measured at 665 nm. PMID:18964725

  20. Lunar Prospector Orbit Determination Results

    NASA Technical Reports Server (NTRS)

    Beckman, Mark; Concha, Marco

    1998-01-01

    The orbit support for Lunar Prospector (LP) consists of three main areas: (1) cislunar orbit determination, (2) rapid maneuver assessment using Doppler residuals, and (3) routine mapping orbit determination. The cislunar phase consisted of two trajectory correction maneuvers during the translunar cruise followed by three lunar orbit insertion burns. This paper will detail the cislunar orbit determination accuracy and the real-time assessment of the cislunar trajectory correction and lunar orbit insertion maneuvers. The non-spherical gravity model of the Moon is the primary influence on the mapping orbit determination accuracy. During the first two months of the mission, the GLGM-2 lunar potential model was used. After one month in the mapping orbit, a new potential model was developed that incorporated LP Doppler data. This paper will compare and contrast the mapping orbit determination accuracy using these two models. LP orbit support also includes a new enhancement - a web page to disseminate all definitive and predictive trajectory and mission planning information. The web site provides definitive mapping orbit ephemerides including moon latitude and longitude, and four week predictive products including: ephemeris, moon latitude/longitude, earth shadow, moon shadow, and ground station view periods. This paper will discuss the specifics of this web site.

  1. Panchromatic Hubble Andromeda Treasury. XVI. Star Cluster Formation Efficiency and the Clustered Fraction of Young Stars

    NASA Astrophysics Data System (ADS)

    Johnson, L. Clifton; Seth, Anil C.; Dalcanton, Julianne J.; Beerman, Lori C.; Fouesneau, Morgan; Lewis, Alexia R.; Weisz, Daniel R.; Williams, Benjamin F.; Bell, Eric F.; Dolphin, Andrew E.; Larsen, Søren S.; Sandstrom, Karin; Skillman, Evan D.

    2016-08-01

    We use the Panchromatic Hubble Andromeda Treasury survey data set to perform spatially resolved measurements of star cluster formation efficiency (Γ), the fraction of stellar mass formed in long-lived star clusters. We use robust star formation history and cluster parameter constraints, obtained through color–magnitude diagram analysis of resolved stellar populations, to study Andromeda’s cluster and field populations over the last ∼300 Myr. We measure Γ of 4%–8% for young, 10–100 Myr-old populations in M31. We find that cluster formation efficiency varies systematically across the M31 disk, consistent with variations in mid-plane pressure. These Γ measurements expand the range of well-studied galactic environments, providing precise constraints in an H i-dominated, low-intensity star formation environment. Spatially resolved results from M31 are broadly consistent with previous trends observed on galaxy-integrated scales, where Γ increases with increasing star formation rate surface density (ΣSFR). However, we can explain observed scatter in the relation and attain better agreement between observations and theoretical models if we account for environmental variations in gas depletion time (τ dep) when modeling Γ, accounting for the qualitative shift in star formation behavior when transitioning from a H2-dominated to a H i-dominated interstellar medium. We also demonstrate that Γ measurements in high ΣSFR starburst systems are well-explained by τ dep-dependent fiducial Γ models.

  2. International Society for Heart Research--XVI World Congress. 27-31 May 1998, Rhodes, Greece.

    PubMed

    Brown, L

    1998-07-01

    This congress was organized by David Hearse (St Thomas' Hospital, London, UK) and Roberto Ferrari (Brescia, Italy). It was intended to stimulate progress in cardiovascular biology and medicine by allowing basic and clinical scientists to interact and communicate. The 2000 delegates had the opportunity to attend more than 50 major symposia and discuss almost 800 free communications as moderated posters over the five days. The abstracts have been published in the Journal of Molecular and Cellular Cardiology (1998) 30. The achievements of cardiovascular pharmacology were specifically recognized at this meeting, both the advances of the last 30 years as well as the possibilities for the future. The amount of information presented in the six to eight concurrent symposia means that this review will, of necessity, emphasize the reviewer's prejudices regarding the achievements and future directions of cardiovascular pharmacology. PMID:18465548

  3. American Association of Women in Community and Junior Colleges Quarterly; Vol. XVI, Nos. 1-4.

    ERIC Educational Resources Information Center

    AAWCJC Quarterly, 1992

    1992-01-01

    The American Association of Women in Community and Junior Colleges (AAWCJC), an affiliated council of the American Association of Community and Junior Colleges (AACJC), produces the "Quarterly" to disseminate information pertinent to the AAWCJC membership and to provide a forum for the discussion of current issues and events. Each issue of the…

  4. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT XVI, LEARNING ABOUT AC GENERATOR (ALTERNATOR) PRINCIPLES (PART I).

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATING PRINCIPLES OF ALTERNATING CURRENT GENERATORS USED ON DIESEL POWERED EQUIPMENT. TOPICS ARE REVIEWING ELECTRICAL FUNDAMENTALS, AND OPERATING PRINCIPLES OF ALTERNATORS. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL PROGRAMED TRAINING FILM "AC GENERATORS…

  5. 76 FR 56263 - Titles II and XVI: Documenting and Evaluating Disability in Young Adults

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-12

    ...) for employees and 404.1575(d) and 416.975(d) for self-employed; see also SSR 84-25 and SSR 05-2, 70 FR..., and 416.969a. See also SSR 96-8p, 61 FR 34474 (1996), available at: http://www.socialsecurity.gov/OP..., 71 FR 45593 (2006), available at:...

  6. The Path of Carbon in Photosynthesis XVI. Kinetic Relationships of the Intermediates in Steady State Photosynthesis

    DOE R&D Accomplishments Database

    Benson, A. A.; Kawaguchi, S.; Hayes, P.; Calvin, M.

    1952-06-05

    A kinetic study of the accumulation of C{sup 14} in the intermediates of steady state photosynthesis in C{sup 14}O{sub 2} provides information regarding the sequence of reactions involved. The work described applied the radio-chromatographic technique for analysis of the labeled early products. The simultaneous carboxylation reaction resulting in malic acid as well as phosphoglycerate is demonstrated in experiments at high light intensity. A comparison of radioactivities in a number of phosphorylated sugars as a function of time reveals concurrent synthesis of fructose and sedoheptulose phosphates followed by that of ribulose phosphates and later by that of glucose phosphates. The possibility that the cleavage of C{sub 4} compounds to C{sub 2} carbon dioxide acceptors may involve C{sub 7} and C{sub 5} sugars and evidence for this mechanism is presented.

  7. Scientia Paedagogica Experimentalis. International Journal of Experimental Research in Education. XVI, 2.

    ERIC Educational Resources Information Center

    Verbist, R., Ed.; And Others

    1979-01-01

    The first of five articles in this journal reports on a project aimed at studying the influence of the way in which problems of arithmetic are worded. Some variables in the wording were found to affect the performance of children, and terms were isolated which increased the percentage of failure. The second article describes a technique for…

  8. Student Characteristics as Compared to the Community Profile, Fall, 1986. Volume XVI, No. 8.

    ERIC Educational Resources Information Center

    Flaherty, Toni

    In fall 1986, a study was conducted at Illinois' William Rainey Harper College (WRHC) to provide a student profile for general information purposes, to gather data not available on the college's automated student data file, and to analyze WRHC's market outreach. Surveys were mailed to random samples of 500 credit degree students and 300 continuing…

  9. Study of Students Who Withdrew from Courses, 1982-1986. Volume XVI, No. 5.

    ERIC Educational Resources Information Center

    Flaherty, Toni

    A study was conducted at William Rainey Harper College (WRHC) to develop a profile of students who withdrew from courses between 1982 and 1986 and to compare this profile with the results of a 1979-82 withdrawal study. For the past 4 years, each degree credit student who has officially withdrawn from a course has been asked to complete a survey…

  10. Student Characteristics as Compared to the Community Profile, Fall 1987. Volume XVI, No. 13.

    ERIC Educational Resources Information Center

    Flaherty, Toni

    In fall 1987, a study was conducted at William Rainey Harper College (WRHC) to develop a profile of WRHC students and assess the college's market outreach. Surveys were mailed to random samples of 500 degree credit students and 300 non-degree credit students. Response rates of 80% for the degree credit students and 78% for the non-degree credit…

  11. [Clinical research XVI. Differences between medians with the Mann-Whitney U test].

    PubMed

    Rivas-Ruiz, Rodolfo; Moreno-Palacios, Jorge; Talavera, Juan O

    2013-01-01

    If you want to prove that there are differences between two groups with quantitative variables with non-normal distribution, the Mann-Whitney U test is used. This test is opposite of the Student t test that uses quantitative variables with a normal distribution. If you want to compare three or more nonrelated groups, the Kruskal-Wallis test is applied. When two related samples are compared, the Wilcoxon test is the best option (a before and after maneuver comparison); when three related samples are compared, the Friedman test is used. These tests correspond to the parametric opposing paired t test and ANOVA, respectively. PMID:24021070

  12. Chinese-Mandarin: Basic Course. Volume XVI: Lessons 168-180.

    ERIC Educational Resources Information Center

    Defense Language Inst., Monterey, CA.

    This is the last of 16 volumes of audiolingual classroom instruction in Mandarin Chinese. The course is designed to train native English speakers to Level 3 Foreign Service Institute proficiency in comprehension and speaking, and to Level 2 proficiency in reading and writing Mandarin. Facility in reading, writing, and translating texts written in…

  13. Limits to sustained energy intake. XVI. Body temperature and physical activity of female mice during pregnancy.

    PubMed

    Gamo, Yuko; Bernard, Amelie; Mitchell, Sharon E; Hambly, Catherine; Al Jothery, Aqeel; Vaanholt, Lobke M; Król, Elzbieta; Speakman, John R

    2013-06-15

    Lactation is the most energy-demanding phase of mammalian reproduction, and lactation performance may be affected by events during pregnancy. For example, food intake may be limited in late pregnancy by competition for space in the abdomen between the alimentary tract and fetuses. Hence, females may need to compensate their energy budgets during pregnancy by reducing activity and lowering body temperature. We explored the relationships between energy intake, body mass, body temperature and physical activity throughout pregnancy in the MF1 mouse. Food intake and body mass of 26 females were recorded daily throughout pregnancy. Body temperature and physical activity were monitored every minute for 23 h a day by implanted transmitters. Body temperature and physical activity declined as pregnancy advanced, while energy intake and body mass increased. Compared with a pre-mating baseline period, mice increased energy intake by 56% in late pregnancy. Although body temperature declined as pregnancy progressed, this served mostly to reverse an increase between baseline and early pregnancy. Reduced physical activity may compensate the energy budget of pregnant mice but body temperature changes do not. Over the last 3 days of pregnancy, food intake declined. Individual variation in energy intake in the last phase of pregnancy was positively related to litter size at birth. As there was no association between the increase in body mass and the decline in intake, we suggest the decline was not caused by competition for abdominal space. These data suggest overall reproductive performance is probably not constrained by events during pregnancy. PMID:23720802

  14. VizieR Online Data Catalog: Speckle interferometry at USNO. XVI. (Mason+, 2011)

    NASA Astrophysics Data System (ADS)

    Mason, B. D.; Hartkopf, W. I.; Wycoff, G. L.

    2012-08-01

    The results of 1031 speckle-interferometric observations of double stars, made with the 26 inch refractor of the U.S. Naval Observatory, are presented. Each speckle-interferometric observation of a system represents a combination of over two thousand short-exposure images. These observations are averaged into 457 mean relative positions and range in separation from 0.15" to 16.94", with a median separation of 3.03". The range in V-band magnitudes for the primary (secondary) of observed targets is 3.1-12.9 (3.2-13.3). (2 data files).

  15. 20 CFR 416.590 - Are there additional methods for recovery of title XVI benefit overpayments?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... collection activity under applicable rules, such as, the Federal Claims Collection Standards in 31 CFR 903.2... an eligible couple that is legally separated and/or living apart, we will deem unrecoverable from...

  16. 20 CFR 416.590 - Are there additional methods for recovery of title XVI benefit overpayments?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... collection activity under applicable rules, such as, the Federal Claims Collection Standards in 31 CFR 903.2... an eligible couple that is legally separated and/or living apart, we will deem unrecoverable from...

  17. Panchromatic Hubble Andromeda Treasury. XVI. Star Cluster Formation Efficiency and the Clustered Fraction of Young Stars

    NASA Astrophysics Data System (ADS)

    Johnson, L. Clifton; Seth, Anil C.; Dalcanton, Julianne J.; Beerman, Lori C.; Fouesneau, Morgan; Lewis, Alexia R.; Weisz, Daniel R.; Williams, Benjamin F.; Bell, Eric F.; Dolphin, Andrew E.; Larsen, Søren S.; Sandstrom, Karin; Skillman, Evan D.

    2016-08-01

    We use the Panchromatic Hubble Andromeda Treasury survey data set to perform spatially resolved measurements of star cluster formation efficiency (Γ), the fraction of stellar mass formed in long-lived star clusters. We use robust star formation history and cluster parameter constraints, obtained through color–magnitude diagram analysis of resolved stellar populations, to study Andromeda’s cluster and field populations over the last ˜300 Myr. We measure Γ of 4%–8% for young, 10–100 Myr-old populations in M31. We find that cluster formation efficiency varies systematically across the M31 disk, consistent with variations in mid-plane pressure. These Γ measurements expand the range of well-studied galactic environments, providing precise constraints in an H i-dominated, low-intensity star formation environment. Spatially resolved results from M31 are broadly consistent with previous trends observed on galaxy-integrated scales, where Γ increases with increasing star formation rate surface density (ΣSFR). However, we can explain observed scatter in the relation and attain better agreement between observations and theoretical models if we account for environmental variations in gas depletion time (τ dep) when modeling Γ, accounting for the qualitative shift in star formation behavior when transitioning from a H2-dominated to a H i-dominated interstellar medium. We also demonstrate that Γ measurements in high ΣSFR starburst systems are well-explained by τ dep-dependent fiducial Γ models.

  18. Oral histories in meteoritics and planetary science—XVI: Donald D. Bogard

    NASA Astrophysics Data System (ADS)

    Sears, Derek W. G.

    2012-03-01

    Donald D. Bogard (Don, Fig. 1) became interested in meteorites after seeing the Fayetteville meteorite in an undergraduate astronomy class at the University of Arkansas. During his graduate studies with Paul Kuroda at Arkansas, Don helped discover the Xe decay products of 244Pu. After a postdoctoral period at Caltech, where he learned much from Jerry Wasserburg, Peter Eberhardt, Don Burnett, and Sam Epstein, Don became one of a number of young Ph.D. scientists hired by NASA's Manned Spacecraft Center to set up the Lunar Receiving Laboratory (LRL) and to perform a preliminary examination of Apollo samples. In collaboration with Oliver Schaeffer (SUNY), Joseph Zähringer (Max Planck, Heidelberg), and Raymond Davis (Brookhaven National Laboratory), he built a gas analysis laboratory at JSC, and the noble gas portion of this laboratory remained operational until he retired in 2010. At NASA, Don worked on the lunar regolith, performed pioneering work on cosmic ray produced noble gas isotopes and Ar-Ar dating, the latter for important insights into the thermal and shock history of meteorites and lunar samples. During this work, he discovered that the trapped gases in SNC meteorites were very similar to those of the Martian atmosphere and thus established their Martian origin. Among Don's many administrative accomplishments are helping to establish the Antarctic meteorite and cosmic dust processing programs at JSC and serving as a NASA-HQ discipline scientist, where he advanced peer review and helped create new programs. Don is a recipient of NASA's Scientific Achievement and Exceptional Service Medals and the Meteoritical Society's Leonard Medal.

  19. E1 and E2 transitions for Fe XVI, Co XVII and Ni XVIII

    NASA Astrophysics Data System (ADS)

    Çelik, G.; Ateş, Ş.

    2016-07-01

    Electric dipole and electric quadrupole transition data for sodium-like iron, cobalt and nickel have been calculated within the weakest bound electron potential model (WBEPM) theory using experimental energy levels and theoretical expectation values of orbital radii corresponding to those energy levels under the assumption of the {LS} coupling scheme. The results obtained from this study provide theoretical transition probability and oscillator strength data requested in many fields of researches, especially astrophysics. The calculated transition data results have been compared with available data in the literature. The present results are consistent with earlier calculations. Some new electric quadrupole transition probability values not existing in the data bases, especially for iron have been obtained using this method.

  20. Vinyl ethers containing an epoxy group. XVI. Reaction of glycidol vinyloxyethyl ether with acetals

    SciTech Connect

    Nedolya, N.A.; Khil'ko, M.Ya.; Trofimov, B.A.; Sigalov, M.V.

    1988-10-10

    In order to obtain branched acetals with epoxide groups (prospective monomers and intermediates) the authors investigated the reaction of acetaldehyde diethyl and di(1,1,3-trihydrotetrafluoropropyl) acetals with glycidol vinyloxyethyl ether. The addition of acetals to vinyl epoxy ethers was realized, and the first representative of compounds of this type, i.e., 9-glycidyloxy-6-ethoxy-4-methyl-3,7-dioxanonane, was obtained. It was also impossible to add a fluoroacetal to butyl vinyl ether (0.08-1.00 wt. % of catalyst CF/sub 3/COOH, BF/sub 3//times/ OEt/sub 2/, 20-80/degree/C, 0.5-3 h).

  1. Raman spectra of gases. XVI - Torsional transitions in ethanol and ethanethiol

    NASA Technical Reports Server (NTRS)

    Durig, J. R.; Bucy, W. E.; Wurrey, C. J.; Carreira, L. A.

    1975-01-01

    The Raman spectra of gaseous ethanol and ethanethiol have been investigated. Thiol torsional fundamentals for the gauche conformer of EtSH and EtSD have been observed and the asymmetric potential function for this vibration has been calculated. Methyl torsional transitions and overtones have also been observed for both of these molecules. Barriers to internal rotation for the methyl top are calculated to be 3.77 and 3.84 kcal/mol for the EtSH and EtSD compounds, respectively. Hydroxyl torsional fundamentals were observed at 207 and 170 per cm in the EtOH and EtOD spectra, respectively. Overtones of the methyl torsion in both molecules yield a barrier to internal rotation of 3.62 kcal/mol for the gauche conformer.

  2. Proceedings of Workshop XVI; The dynamic characteristics of faulting inferred from recordings of strong ground motion

    USGS Publications Warehouse

    1982-01-01

    The strong ground motions radiated by earthquake faulting are controlled by the dynamic characteristics of the faulting process. Although this assertion seems self-evident, seismologists have only recently begun to derive and test quantitative relations between common measures of strong ground motion and the dynamic characteristics of faulting. Interest in this problem has increased dramatically in past several years, however, resulting in a number of important advances. The research presented in this workshop is a significant part of this scientific development. Watching this development occur through the work of many scientists is exciting; to be able to gather a number of these scientists together in one workshop is a remarkable opportunity.

  3. [Elena de Cespedes: The eventful life of a XVI century surgeon].

    PubMed

    Carrillo Esper, Raúl; Carrillo Córdova, Jorge Raúl; Carrillo Córdova, Luis Daniel; Carrillo Córdova, Dulce María; Carrillo Córdova, Carlos Alberto

    2015-01-01

    Throughout the history of surgery there have been exceptional cases of surgeons around the world. One of them is Elena/o of Cespedes. Born as a girl, this hermaphrodite dedicated all his life to acting as a man, doing jobs that were only for men such as a soldier, peasant, and surgeon. She was the first licensed surgeon in Spain and maybe in all Europe. She married a woman and then was tried for sodomy by the Spanish Inquisition commanded by inquisitor Lope de Mendoza. She was founded guilty and punished with 200 lashes and a 10-year service at a hospital, dressed as a woman. PMID:26290033

  4. Follow-Up Study of Former Students of the Executive Secretarial Program. Volume XVI, No. 2.

    ERIC Educational Resources Information Center

    Jirak, Mary Ann; Lucas, John A.

    A study was conducted at Illinois' William Rainey Harper College (WRHC) to assess the current employment experiences of students who had been enrolled in the college's Executive Secretarial Program. The study population consisted of all 232 students who completed SEC-237 (Secretarial Seminar and Internship) between fall 1976 and spring 1986, and…

  5. Chelation in metal intoxication XVI. Influence of chelating agents on chromate poisoned rats

    SciTech Connect

    Tandon, S.K.; Srivastava, L.

    1985-01-01

    The ability of selective polyaminocarboxylic acids and common drugs to reduce the body burden of chromium and restore Cr induced biochemical alterations in chromate intoxicated rats was investigated. 1,2 Cychlohexylene dinitrilotetraacetic acid (CDTA) and triethylenetetramine hexacetic acid (TTHA) were more effective than p-aminosalicylic acid (PAS) and isoniazid (INH) in enhancing urinary excretion of Cr, lowering hepatic and blood levels of Cr and restoring inhibited activity of hepatic aldolase. The chromate antidotal property of chelators seem to be related to the combination of nitrogen and oxygen as the electron donating centres.

  6. A Predictive Framework for Determining How Journalists Determine News.

    ERIC Educational Resources Information Center

    Gaudino, James L.

    To determine how to articulate a concrete definition of the substance of the journalist's occupation, this paper offers a propositional framework of news value based on Kurt Lewin's gatekeeper model. First, the paper follows the established suggestion that news decisions are best studied from a gatekeeping perspective or that "news is whatever…

  7. Ecotoxicological Perspectives of Sex Determination.

    PubMed

    Mizoguchi, Beatriz A; Valenzuela, Nicole

    2016-01-01

    Sex determination or the commitment of the embryo to its sexual fate is a fundamental developmental process with paramount consequences in ecology and evolution. This process, whether triggered by environmental factors or genotypic constitution, can be derailed by environmental contaminants that alter the endocrine system, which is a key component of the regulatory network underlying vertebrate sex determination. Here, we review the molecular basis of sex determination, the endocrine components of its regulation, the maternal and endogenous sources of hormones to the developing embryo, and the routes through which endocrine disrupting chemicals (EDCs) affect gonadal development in reptiles, especially turtles. Among EDCs, we focus on PCBs, BPA, pesticides like atrazine, nitrates, and heavy metals. We also consider whether adaptation might be possible in the face of persistent chemical insult and conclude that, while plausible, contemporary environmental change may outpace adaptive evolution, particularly for many species that are already endangered and suffer from small population sizes. PMID:27022970

  8. Spectral Determinants on Mandelstam Diagrams

    NASA Astrophysics Data System (ADS)

    Hillairet, Luc; Kalvin, Victor; Kokotov, Alexey

    2016-04-01

    We study the regularized determinant of the Laplacian as a functional on the space of Mandelstam diagrams (noncompact translation surfaces glued from finite and semi-infinite cylinders). A Mandelstam diagram can be considered as a compact Riemann surface equipped with a conformal flat singular metric {|ω|^2}, where {ω} is a meromorphic one-form with simple poles such that all its periods are pure imaginary and all its residues are real. The main result is an explicit formula for the determinant of the Laplacian in terms of the basic objects on the underlying Riemann surface (the prime form, theta-functions, the canonical meromorphic bidifferential) and the divisor of the meromorphic form {ω}. As an important intermediate result we prove a decomposition formula of the type of Burghelea-Friedlander-Kappeler for the determinant of the Laplacian for flat surfaces with cylindrical ends and conical singularities.

  9. Determining distances using asteroseismic methods

    NASA Astrophysics Data System (ADS)

    Silva Aguirre, V.; Casagrande, L.; Basu, S.; Campante, T. L.; Chaplin, W. J.; Huber, D.; Miglio, A.; Serenelli, A. M.

    2013-02-01

    Asteroseismology has been extremely successful in determining the properties of stars in different evolutionary stages with a remarkable level of precision. However, to fully exploit its potential, robust methods for estimating stellar parameters are required and independent verification of the results is needed. In this talk, I present a new technique developed to obtain stellar properties by coupling asteroseismic analysis with the infrared flux method. Using two global seismic observables and multi-band photometry, the technique determines masses, radii, effective temperatures, bolometric fluxes, and thus distances for field stars in a self-consistent manner. Applying our method to a sample of solar-like oscillators in the Kepler field that have accurate Hipparcos parallaxes, we find agreement in our distance determinations to better than 5 %. Comparison with measurements of spectroscopic effective temperatures and interferometric radii also validate our results, and show that our technique can be applied to stars evolved beyond the main-sequence phase.

  10. Determination of radium in water

    USGS Publications Warehouse

    Barker, Franklin Butt; Johnson, J.O.

    1964-01-01

    Radium isotopes are common radioactive constituents of natural waters. The concentration of radium-226 in potable water is of particular significance because this isotope is generally considered the most hazardous of all radionuclides with respect to ingestion. The approximate concentration of radium-226 is determined after coprecipitating radium with barium sulfate. The short-lived daughters of radium are allowed to grow for 10-12 days, then the alpha activity of the precipitate is measured and compared with that of a precipitate containing a known amount of radium-226. Concentrations of the individual alpha-emitting isotopes of radium-223, radium-224, and radium-226, are determined by coprecipitating radium first with lead sulfate, then with barium chloride, and finally with barium sulfate. This final precipitate is initially free of other alpha-emitting nuclides, thus permitting the isotopic composition to be determined by measuring the growth and decay of the alpha activity of the precipitate.

  11. Lessons for Inductive Germline Determination

    PubMed Central

    Seervai, Riyad N.H.; Wessel, Gary M.

    2015-01-01

    SUMMARY Formation of the germline in an embryo marks a fresh round of reproductive potential, yet the developmental stage and location within the embryo where the primordial germ cells (PGCs) form differs wildly among species. In most animals, the germline is formed either by an inherited mechanism, in which maternal provisions within the oocyte drive localized germ-cell fate once acquired in the embryo, or an inductive mechanism that involves signaling between cells that directs germ-cell fate. The inherited mechanism has been widely studied in model organisms such as Drosophila melanogaster, Caenorhabditis elegans, Xenopus laevis, and Danio rerio. Given the rapid generation time and the effective adaptation for laboratory research of these organisms, it is not coincidental that research on these organisms has led the field in elucidating mechanisms for germline specification. The inductive mechanism, however, is less well understood and is studied primarily in the mouse (Mus musculus). In this review, we compare and contrast these two fundamental mechanisms for germline determination, beginning with the key molecular determinants that play a role in the formation of germ cells across all animal taxa. We next explore the current understanding of the inductive mechanism of germ-cell determination in mice, and evaluate the hypotheses for selective pressures on these contrasting mechanisms. We then discuss the hypothesis that the transition between these determination mechanisms, which has happened many times in phylogeny, is more of a continuum than a binary change. Finally, we propose an analogy between germline determination and sex determination in vertebrates—two of the milestones of reproduction and development—in which animals use contrasting strategies to activate similar pathways. PMID:23450642

  12. Determinate-state convolutional codes

    NASA Technical Reports Server (NTRS)

    Collins, O.; Hizlan, M.

    1991-01-01

    A determinate state convolutional code is formed from a conventional convolutional code by pruning away some of the possible state transitions in the decoding trellis. The type of staged power transfer used in determinate state convolutional codes proves to be an extremely efficient way of enhancing the performance of a concatenated coding system. The decoder complexity is analyzed along with free distances of these new codes and extensive simulation results is provided of their performance at the low signal to noise ratios where a real communication system would operate. Concise, practical examples are provided.

  13. MEANS FOR DETERMINING CENTRIFUGE ALIGNMENT

    DOEpatents

    Smith, W.Q.

    1958-08-26

    An apparatus is presented for remotely determining the alignment of a centrifuge. The centrifage shaft is provided with a shoulder, upon which two followers ride, one for detecting radial movements, and one upon the shoulder face for determining the axial motion. The followers are attached to separate liquid filled bellows, and a tube connects each bellows to its respective indicating gage at a remote location. Vibrations produced by misalignment of the centrifuge shaft are transmitted to the bellows, and tbence through the tubing to the indicator gage. This apparatus is particularly useful for operation in a hot cell where the materials handled are dangerous to the operating personnel.

  14. Decoherence, determinism and chaos revisited

    SciTech Connect

    Noyes, H.P.

    1994-11-15

    We suggest that the derivation of the free space Maxwell Equations for classical electromagnetism, using a discrete ordered calculus developed by L.H. Kauffman and T. Etter, necessarily pushes the discussion of determinism in natural science down to the level of relativistic quantum mechanics and hence renders the mathematical phenomena studied in deterministic chaos research irrelevant to the question of whether the world investigated by physics is deterministic. We believe that this argument reinforces Suppes` contention that the issue of determinism versus indeterminism should be viewed as a Kantian antinomy incapable of investigation using currently available scientific tools.

  15. Determination of pyrotechnic functional margin

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1993-01-01

    Following the failure of a previously qualified pyrotechnically actuated pin puller design, an investigation led to a redesign and requalification. The emphasis of the second qualification was placed on determining the functional margin of the pin puller by comparing the energy deliverable by the pyrotechnic cartridge to the energy required to accomplish the function. Also determined were the effects of functional variables. This paper describes the failure investigation, the test methods employed and the results of the evaluation, and provides a recommended approach to assure the successful functioning of pyrotechnic devices.

  16. Determination of pyrotechnic functional margin

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1992-01-01

    Following the failure of a previously qualified pyrotechnically actuated pin puller design, an investigation led to a redesign and requalification. The emphasis of the second qualification was placed on determining the functional margin of the pin puller by comparing the energy deliverable by the pyrotechnic cartridge to the energy required to accomplish the function. Also determined were the effects of functional variables. This paper describes the failure investigation, the test methods employed and the results of the evaluation, and provides a recommended approach to assure the successful functioning of pyrotechnic devices.

  17. Self-Determination and Choice

    ERIC Educational Resources Information Center

    Wehmeyer, Michael L.; Abery, Brian H.

    2013-01-01

    Promoting self-determination and choice opportunities for people with intellectual and developmental disabilities has become best practice in the field. This article reviews the research and development activities conducted by the authors over the past several decades and provides a synthesis of the knowledge in the field pertaining to efforts to…

  18. Cesium Eluate Physical Property Determination

    SciTech Connect

    Baich, M.A.

    2001-02-13

    Two bench-scale process simulations of the proposed cesium eluate evaporation process of concentrating eluate produced in the Hanford Site Waste Treatment Plant were conducted. The primary objective of these experiments was to determine the physical properties and the saturation concentration of the eluate evaporator bottoms while producing condensate approximately 0.50 molar HN03.

  19. The Determinants of Pay Satisfaction

    ERIC Educational Resources Information Center

    Dyer, Lee; Theriault, Roland

    1976-01-01

    Through a study of American and Canadian managers, tested the utility of Lawler's model of the determinants of pay satisfaction and the value of adding to Lawler's model a category of variables for perceptions of pay-system administration. The study findings are then used to develop a modified model. For availability see EA 507 670. (Author/JG)

  20. Determining Salinity by Simple Means.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.

    This paper describes the construction and use of a simple salinometer. The salinometer is composed, mainly, of a milliammeter and a battery and uses the measurement of current flow to determine the salinity of water. A complete list of materials is given, as are details of construction and operation of the equipment. The use of the salinometer in…

  1. Self-Determination: First Steps.

    ERIC Educational Resources Information Center

    Thompson, Morris

    The year 1974 marked the first full year in which the Bureau of Indian Affairs (BIA) officially embarked on a policy of advising and assisting American Indian tribes to assume the administration of their own affairs (self-determination). It seeks to strengthen and stabilize tribal governments while continuing to maintain and fulfill its trust…

  2. Determinants and Polynomial Root Structure

    ERIC Educational Resources Information Center

    De Pillis, L. G.

    2005-01-01

    A little known property of determinants is developed in a manner accessible to beginning undergraduates in linear algebra. Using the language of matrix theory, a classical result by Sylvester that describes when two polynomials have a common root is recaptured. Among results concerning the structure of polynomial roots, polynomials with pairs of…

  3. Formulas for determining rotational constants

    NASA Astrophysics Data System (ADS)

    Guelachvili, G.

    This document is part of Subvolume B `Linear Triatomic Molecules', Part 9, of Volume 20 `Molecular Constants mostly from Infrared Spectroscopy' of Landolt-Börnstein Group II `Molecules and Radicals'. Part of the introduction, it states formulas for determining rotational constants, band center, band origin, and quadrupole coupling. Specific comments relate to BHO (HBO) and COS (OCS).

  4. Inulin determination for food labeling.

    PubMed

    Zuleta, A; Sambucetti, M E

    2001-10-01

    Inulin and oligofructose exhibit valuable nutritional and functional attributes, so they are used as supplements as soluble fiber or as macronutrient substitutes. As classic analytical methods for dietary fiber measurement are not effective, several specific methods have been proposed. These methods measure total fructans and are based on one or more enzymatic sample treatments and determination of released sugars. To determine inulin for labeling purposes, we developed an easy and rapid anion-exchange high-performance liquid chromatography (HPLC) method following water extraction of inulin. HPLC conditions included an Aminex HPX- 87C column (Bio-Rad), deionized water at 85 degrees C as the mobile phase and a refractive index detector. The tested foods included tailor-made food products containing known amounts of inulin and commercial products (cookies, milk, ice creams, cheese, and cereal bars). The average recovery was 97%, and the coefficient of variation ranged from 1.1 to 5% in the food matrixes. The obtained results showed that this method provides an easier, faster and cheaper alternative than previous techniques for determining inulin with enough accuracy and precision for routine labeling purposes by direct determination of inulin by HPLC with refractive index detection. PMID:11599989

  5. Plasma digital density determining device

    DOEpatents

    Sprott, Julien C.; Lovell, Thomas W.; Holly, Donald J.

    1976-01-01

    The density of a decaying plasma in an electrically conducting enclosure is determined by applying an excitation to the cavity formed by the enclosure and counting digitally the number of resonant frequencies traversed by the combination of the cavity and the decaying plasma.

  6. Cohesin in determining chromosome architecture

    SciTech Connect

    Haering, Christian H.; Jessberger, Rolf

    2012-07-15

    Cells use ring-like structured protein complexes for various tasks in DNA dynamics. The tripartite cohesin ring is particularly suited to determine chromosome architecture, for it is large and dynamic, may acquire different forms, and is involved in several distinct nuclear processes. This review focuses on cohesin's role in structuring chromosomes during mitotic and meiotic cell divisions and during interphase.

  7. Self-Determination and Bilingualism

    ERIC Educational Resources Information Center

    Landry, Rodrigue; Allard, Real; Deveau, Kenneth

    2009-01-01

    This article focuses on additive bilingualism for minority group children, more specifically the development of strong literacy skills in English and in the children's language. The personal autonomization language learning (PALL) model is presented. It specifies eight testable hypotheses. Self-determination theory (SDT) is central in the PALL…

  8. Determining Readability with a Microcomputer.

    ERIC Educational Resources Information Center

    Kennedy, Keith

    1985-01-01

    Discusses history of the development of computer software to determine material readability and general design of readability software. Tables present summaries of: (1) parameters used by selected readability scales and their grade level applications; and (2) microcomputer software programs available, including readability techniques included in…

  9. Videos Determine the Moon's "g"

    ERIC Educational Resources Information Center

    Persson, J. R.; Hagen, J. E.

    2011-01-01

    Determining the acceleration of a free-falling object due to gravity is a standard experiment in physics. Different methods to do this have been developed over the years. This article discusses the use of video-analysis tools as another method. If there is a video available and a known scale it is possible to analyse the motion. The use of video…

  10. Means of determining extrusion temperatures

    DOEpatents

    McDonald, Robert E.; Canonico, Domenic A.

    1977-01-01

    In an extrusion process comprising the steps of fabricating a metal billet, heating said billet for a predetermined time and at a selected temperature to increase its plasticity and then forcing said heated billet through a small orifice to produce a desired extruded object, the improvement comprising the steps of randomly inserting a plurality of small metallic thermal tabs at different cross sectional depths in said billet as a part of said fabricating step, and examining said extruded object at each thermal tab location for determining the crystal structure at each extruded thermal tab thus revealing the maximum temperature reached during extrusion in each respective tab location section of the extruded object, whereby the thermal profile of said extruded object during extrusion may be determined.

  11. Low thrust orbit determination program

    NASA Technical Reports Server (NTRS)

    Hong, P. E.; Shults, G. L.; Huling, K. R.; Ratliff, C. W.

    1972-01-01

    Logical flow and guidelines are provided for the construction of a low thrust orbit determination computer program. The program, tentatively called FRACAS (filter response analysis for continuously accelerating spacecraft), is capable of generating a reference low thrust trajectory, performing a linear covariance analysis of guidance and navigation processes, and analyzing trajectory nonlinearities in Monte Carlo fashion. The choice of trajectory, guidance and navigation models has been made after extensive literature surveys and investigation of previous software. A key part of program design relied upon experience gained in developing and using Martin Marietta Aerospace programs: TOPSEP (Targeting/Optimization for Solar Electric Propulsion), GODSEP (Guidance and Orbit Determination for SEP) and SIMSEP (Simulation of SEP).

  12. Luminosity determination at proton colliders

    NASA Astrophysics Data System (ADS)

    Grafström, P.; Kozanecki, W.

    2015-03-01

    Luminosity is a key parameter in any particle collider, and its precise determination has proven particularly challenging at hadron colliders. After introducing the concept of luminosity in its multiple incarnations and offering a brief survey of the pp and p p bar colliders built to date, this article outlines the various methods that have been developed for relative-luminosity monitoring, as well as the complementary approaches considered for establishing an absolute luminosity scale. This is followed by a survey, from both a historical and a technical perspective, of luminosity determination at the ISR, the S p p ¯ S, the Tevatron, RHIC and the LHC. For each of these, we first delineate the interplay between the experimental context, the specificities of the accelerator, and the precision targets suggested by the physics program. We then detail how the different methods were applied to specific experimental environments and how successfully they meet the precision goals.

  13. [Immunochemical determination of human lactoferrin].

    PubMed

    German, G P; Lavrova, N V; Sherer, L A

    1983-09-01

    The immunochemically pure preparation of lactoferrin was isolated from human colostrum and used for the immunization of animals with a view of obtaining antiserum, and also as a reference preparation for the determination of the content of lactoferrin in the standard. The monospecific antiserum to lactoferrin, obtained as the result of this procedure, was used for the determination of the content of lactoferrin in samples of human milk by the method of radial immunodiffusion. Through the content of lactoferrin in human milk showed considerable fluctuations, its level essentially decreased on the second week of lactation. In cases of the microbial contamination of milk the tendency towards an increase in the content of lactoferrin was observed irrespective of the time of lactation. PMID:6415975

  14. Asteroid candidates for mass determination

    NASA Astrophysics Data System (ADS)

    Galád, A.

    2001-04-01

    The first 9511 numbered asteroids are studied in terms of their mutual closest approaches and encounter velocities during the period from November 6, 1967, to September 13, 2023. Several large asteroids (diameter 200 km and above) were (will be) encountered by smaller counterparts within a distance of 0.0200 AU. Thus, they are possible candidates for mass determination by the astrometrical method. Similarly, the search for effective perturbers is extended to even smaller asteroids for the much closer separation distance of 0.0020 AU and below. Only the simplified method for evaluation of observable effects on a perturbed body is used. Asteroid masses alone are not computed here. But a stronger criterion to reveal pairs for this purpose in comparison to some specially devoted papers should compensate for the difference and act as a reliable test. The best candidates for mass determination at present are asteroids (1), (2), (4), (10), (11), (24), (52) and (65). This list may be extended by at least (29) in the next 5 years and by many others in the next two decades. Several other strong perturbers from the last three decades are not included in the list, while there is still only a limited number of (or no) precise and reliable observations of perturbed asteroids before a close encounter. It seems that a perturbation by (10) is at least as effective as that by (2) and could be included in asteroid orbit determination in the future. Except for their bulk density determinations (knowing the size), the masses of perturbers could occasionally be used to improve the precision of the computed orbit for perturbed large-numbered and unnumbered asteroids as well.

  15. In-flight thrust determination

    NASA Technical Reports Server (NTRS)

    Abernethy, Robert B.; Adams, Gary R.; Ascough, John C.; Baer-Riedhart, Jennifer L.; Balkcom, George H.; Biesiadny, Thomas

    1986-01-01

    The major aspects of processes that may be used for the determination of in-flight thrust are reviewed. Basic definitions are presented as well as analytical and ground-test methods for gathering data and calculating the thrust of the propulsion system during the flight development program of the aircraft. Test analysis examples include a single-exhaust turbofan, an intermediate-cowl turbofan, and a mixed-flow afterburning turbofan.

  16. Determinism in synthesized chaotic waveforms.

    PubMed

    Corron, Ned J; Blakely, Jonathan N; Hayes, Scott T; Pethel, Shawn D

    2008-03-01

    The output of a linear filter driven by a randomly polarized square wave, when viewed backward in time, is shown to exhibit determinism at all times when embedded in a three-dimensional state space. Combined with previous results establishing exponential divergence equivalent to a positive Lyapunov exponent, this result rigorously shows that such reverse-time synthesized waveforms appear equally to have been produced by a deterministic chaotic system. PMID:18517561

  17. Range determination for scannerless imaging

    DOEpatents

    Muguira, Maritza Rosa; Sackos, John Theodore; Bradley, Bart Davis; Nellums, Robert

    2000-01-01

    A new method of operating a scannerless range imaging system (e.g., a scannerless laser radar) has been developed. This method is designed to compensate for nonlinear effects which appear in many real-world components. The system operates by determining the phase shift of the laser modulation, which is a physical quantity related physically to the path length between the laser source and the detector, for each pixel of an image.

  18. Method for determining gene knockouts

    DOEpatents

    Maranas, Costas D.; Burgard, Anthony R.; Pharkya, Priti

    2011-09-27

    A method for determining candidates for gene deletions and additions using a model of a metabolic network associated with an organism, the model includes a plurality of metabolic reactions defining metabolite relationships, the method includes selecting a bioengineering objective for the organism, selecting at least one cellular objective, forming an optimization problem that couples the at least one cellular objective with the bioengineering objective, and solving the optimization problem to yield at least one candidate.

  19. Method for determining gene knockouts

    DOEpatents

    Maranas, Costa D; Burgard, Anthony R; Pharkya, Priti

    2013-06-04

    A method for determining candidates for gene deletions and additions using a model of a metabolic network associated with an organism, the model includes a plurality of metabolic reactions defining metabolite relationships, the method includes selecting a bioengineering objective for the organism, selecting at least one cellular objective, forming an optimization problem that couples the at least one cellular objective with the bioengineering objective, and solving the optimization problem to yield at least one candidate.

  20. Gender determination from pulpal tissue

    PubMed Central

    Khorate, Manisha M.; Dhupar, Anita; Ahmed, Junaid; Dinkar, Ajit D.

    2014-01-01

    Objective: To evaluate the diagnostic performance of X (Barr body [BB]) and Y (F body [FB]) chromosomes observed in dental pulp tissue for gender determination of an individual. Materials and Methods: The study was carried out on 100 teeth (50 male and 50 female), which were indicated for extraction. The teeth were sectioned at various intervals (within 12 h to 49 days post-extraction), and the pulpal tissue was obtained. Two slides for each pulp tissue were prepared, one for 5% Quinacrine dihydrochloride stain (FB) and the other for Hemotoxylin and Eosin stain (BB). The slides were then observed under the fluorescent microscope for FB and under the light microscope for the BB respectively. Results: Gender determination from human pulp is possible up to 7 weeks. The percentage of FB and BB decrease gradually as the time interval increases. Further, an equation was derived from the data based on the canonical discriminant function coefficients. Conclusion: The determination of gender based on a joint search for the presence or absence of X (BB) and Y (FB) Chromosome is a reliable and cost-effective technique. PMID:25125918

  1. Meteorological determinants of air quality

    NASA Astrophysics Data System (ADS)

    Turoldo, F.; Del Frate, S.; Gallai, I.; Giaiotti, D. B.; Montanari, F.; Stel, F.; Goi, D.

    2010-09-01

    Air quality is the result of complex phenomena, among which the major role is played by human emissions of pollutants. Atmospheric processes act as determinants, e.g., modulating, dumping or amplifying the effects of emissions as an orchestra's director does with musical instruments. In this work, a series of small-scale and meso-scale meteorological determinants of air-quality are presented as they are observed in an area characterized by complex orography (Friuli Venezia Giulia, in the north-eastern side of Italy). In particular, attention is devoted to: i) meso-scale flows favouring the persistence of high concentrations of particulate matter; ii) meso-scale periodic flows (breezes) favouring high values of particulate matter; iii) local-scale thermodynamic behaviour favouring high atmospheric values of nitrogen oxides. The effects of these different classes of determinants are shown through comparisons between anthropic emissions (mainly traffic) and ground-based measurements. The relevance of complex orography (relatively steep relieves near to the sea) is shown for the meso-scale flows and, in particular, for local-scale periodic flows, which favour the increase of high pollutants concentrations mainly in summer, when the breezes regime is particularly relevant. Part of these results have been achieved through the ETS - Alpine Space EU project iMONITRAF!

  2. Determinism, indeterminism, and explanatory bias.

    PubMed

    Targett, M

    1997-12-01

    Actions are a subclass of human behaviours which are distinguished, on a modest view, by certain antecedent mental and neural processes and events, including desires and beliefs. Libertarian philosophies have taken a less modest view, according to which some actions come under the influence of individual persons in a way distinct from being the necessary effect of a sequence of psychoneural events. Determinism claims necessary connections between sequences of events and conditions, including those sequences that involve desires and beliefs and subsequent actions. Even if a certain interpretation of modern physics shows determinism to be false, the sense of personal influence over action which libertarians have remains obscure. It is not enlightened by the physicist's idea of inexplicable fluctuations between courses of events with greater or lesser probabilities. If libertarianism remains obscure, so do the grounds for an approach to explaining behaviour which might be called "explanatory individualism". According to the latter stance, the local outcomes of actions and larger social tendencies are only properly explained in terms of the choices of individuals, rather than, for example, their neural or environmental antecedents. Again, bare indeterminism will not help to supply the required grounds. A more justifiable stance is "explanatory pluralism", a doctrine which denies the intrinsic priority of individualistic modes of explanation over those which focus on psychoneural, environmental, social or genetic conditions. It is stressed that on a sensible pluralism, any determinism which correctly describes the history of actions would be no more "genetic", than indeterminism could be "individualistic". PMID:9421834

  3. 19 CFR 351.205 - Preliminary determination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... determinations, postponement of preliminary determinations, notices of preliminary determinations, and the... its injury determination. (e) Postponement at the request of the petitioner. A petitioner must submit a request for postponement of the preliminary determination (see section 703(c)(1)(A) or section...

  4. The Heat of Protonation of Pyridine and Chloro Substituted Pyridines: A Physical Chemistry Laboratory Experiment.

    ERIC Educational Resources Information Center

    Smith, Robert L.; Pinnick, H. R., Jr.

    1980-01-01

    Describes a physical chemistry laboratory experiment that illustrates the concepts of inductive and resonance effects by the calorimetric determination of the heats of protonation of pyridine, 2-chloropyridine, and 3-chloropyridine. (CS)

  5. Soil carbon determination by thermogravimetrics

    PubMed Central

    Pallasser, Robert; McBratney, Alex B.

    2013-01-01

    Determination of soil constituents and structure has a vital role in agriculture generally. Methods for the determination of soil carbon have in particular gained greater currency in recent times because of the potential that soils offer in providing offsets for greenhouse gas (CO2-equivalent) emissions. Ideally, soil carbon which can also be quite diverse in its makeup and origin, should be measureable by readily accessible, affordable and reliable means. Loss-on-ignition is still a widely used method being suitably simple and available but may have limitations for soil C monitoring. How can these limitations be better defined and understood where such a method is required to detect relatively small changes during soil-C building? Thermogravimetric (TGA) instrumentation to measure carbonaceous components has become more interesting because of its potential to separate carbon and other components using very precise and variable heating programs. TGA related studies were undertaken to assist our understanding in the quantification of soil carbon when using methods such as loss-on-ignition. Combining instrumentation so that mass changes can be monitored by mass spectrometer ion currents has elucidated otherwise hidden features of thermal methods enabling the interpretation and evaluation of mass-loss patterns. Soil thermogravimetric work has indicated that loss-on-ignition methods are best constrained to temperatures from 200 to 430 °C for reliable determination for soil organic carbon especially where clay content is higher. In the absence of C-specific detection where mass only changes are relied upon, exceeding this temperature incurs increasing contributions from inorganic sources adding to mass losses with diminishing contributions related to organic matter. The smaller amounts of probably more recalcitrant organic matter released at the higher temperatures may represent mineral associated material and/or simply more refractory forms. PMID:23638398

  6. Geostationary orbit determination using SATRE

    NASA Astrophysics Data System (ADS)

    Lei, Hui; Li, ZhiGang; Yang, XuHai; Wu, WenJun; Cheng, Xuan; Yang, Ying; Feng, ChuGang

    2011-09-01

    A new strategy of precise orbit determination (POD) for GEO (Geostationary Earth Orbit) satellite using SATRE (SAtellite Time and Ranging Equipment) is presented. Two observation modes are proposed and different channels of the same instruments are used to construct different observation modes, one mode receiving time signals from their own station and the other mode receiving time signals from each other for two stations called pairs of combined observations. Using data from such a tracking network in China, the results for both modes are compared. The precise orbit determination for the Sino-1 satellite using the data from 6 June 2005 to 13 June 2005 has been carried out in this work. The RMS (Root-Mean-Square) of observing residuals for 3-day solutions with the former mode is better than 9.1 cm. The RMS of observing residuals for 3-day solutions with the latter mode is better than 4.8 cm, much better than the former mode. Orbital overlapping (3-day orbit solution with 1-day orbit overlap) tests show that the RMS of the orbit difference for the former mode is 0.16 m in the radial direction, 0.53 m in the along-track direction, 0.97 m in the cross-track direction and 1.12 m in the 3-dimension position and the RMS of the orbit difference for the latter mode is 0.36 m in the radial direction, 0.89 m in the along-track direction, 1.18 m in the cross-track direction and 1.52 m in the 3-dimension position, almost the same as the former mode. All the experiments indicate that a meter-level accuracy of orbit determination for geostationary satellite is achievable.

  7. Characterization of Monoclonal Gammopathy of Undetermined Significance by Calorimetric Analysis of Blood Serum Proteome

    PubMed Central

    Barceló, Francisca; Cerdà, Joan J.; Gutiérrez, Antonio; Jimenez-Marco, Teresa; Durán, M. Antonia; Novo, Andrés; Ros, Teresa; Sampol, Antonia; Portugal, José

    2015-01-01

    Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant proliferative disorder that may progress to multiple myeloma, a malignant plasma cell neoplasia. We evaluated differential scanning calorimetry (DSC) as an experimental tool for differentiating serum samples of MGUS patients from healthy individuals. DSC thermograms can be used for monitoring changes in the serum proteome associated with MGUS. MGUS patients showed great variability in serum thermogram characteristics, which depended on the IgG, IgA or IgM isotypes and/or the κ or λ light chains. Thermogram feature parameters distinguished patients with MGUS from healthy people. Serum samples, named as non-MGUS, were also collected from patients with subjacent immunological pathologies who were discarded of having MGUS through serum immunofixation. They were used to verify the sensitivity of DSC for discriminating MGUS from related blood dyscrasias. Only some DSC thermogram feature parameters differentiated, to a lesser extent, between MGUS and non-MGUS individuals. We contemplate DSC as a tool for early diagnosis and monitoring of MGUS. PMID:25794164

  8. Characterization of monoclonal gammopathy of undetermined significance by calorimetric analysis of blood serum proteome.

    PubMed

    Barceló, Francisca; Cerdà, Joan J; Gutiérrez, Antonio; Jimenez-Marco, Teresa; Durán, M Antonia; Novo, Andrés; Ros, Teresa; Sampol, Antonia; Portugal, José

    2015-01-01

    Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant proliferative disorder that may progress to multiple myeloma, a malignant plasma cell neoplasia. We evaluated differential scanning calorimetry (DSC) as an experimental tool for differentiating serum samples of MGUS patients from healthy individuals. DSC thermograms can be used for monitoring changes in the serum proteome associated with MGUS. MGUS patients showed great variability in serum thermogram characteristics, which depended on the IgG, IgA or IgM isotypes and/or the κ or λ light chains. Thermogram feature parameters distinguished patients with MGUS from healthy people. Serum samples, named as non-MGUS, were also collected from patients with subjacent immunological pathologies who were discarded of having MGUS through serum immunofixation. They were used to verify the sensitivity of DSC for discriminating MGUS from related blood dyscrasias. Only some DSC thermogram feature parameters differentiated, to a lesser extent, between MGUS and non-MGUS individuals. We contemplate DSC as a tool for early diagnosis and monitoring of MGUS. PMID:25794164

  9. High-precision, automated integration of multiple isothermal titration calorimetric thermograms: new features of NITPIC.

    PubMed

    Scheuermann, Thomas H; Brautigam, Chad A

    2015-04-01

    Isothermal titration calorimetry (ITC) has become a standard and widely available tool to measure the thermodynamic parameters of macromolecular associations. Modern applications of the method, including global analysis and drug screening, require the acquisition of multiple sets of data; sometimes these data sets number in the hundreds. Therefore, there is a need for quick, precise, and automated means to process the data, particularly at the first step of data analysis, which is commonly the integration of the raw data to yield an interpretable isotherm. Herein, we describe enhancements to an algorithm that previously has been shown to provide an automated, unbiased, and high-precision means to integrate ITC data. These improvements allow for the speedy and precise serial integration of an unlimited number of ITC data sets, and they have been implemented in the freeware program NITPIC, version 1.1.0. We present a comprehensive comparison of the performance of this software against an older version of NITPIC and a current version of Origin, which is commonly used for integration. The new methods recapitulate the excellent performance of the previous versions of NITPIC while speeding it up substantially, and their precision is significantly better than that of Origin. This new version of NITPIC is therefore well suited to the serial integration of many ITC data sets. PMID:25524420

  10. New calorimetric system and some results of water phase transition research in plant roots.

    PubMed

    Bakradze, N; Kiziria, E; Sokhadze, V; Gogichaishvili, Sh; Vardidze, E

    2007-01-01

    The principle of operation and main parameters of the recently created scanning differential reverse microcalorimeter of the new generation are presented. The microcalorimeter is destined for studying water crystallization and ice melting processes in heterogeneous systems, including plant and animal cells and tissues in the temperature range of 20 to -55 degrees C. In order to obtain maximum information from the experimental results respective algorithms and applied software package were developed. The results of studies of water crystallization and ice melting processes in different parts of common plantain (Plantago major L.) root, as a certain model system, can give us information on the peculiarities of the studied processes in complex, heterogeneous systems. PMID:17522730

  11. Synthesis, calorimetric studies, and crystal structures of N, O-diacylethanolamines with matched chains[S

    PubMed Central

    Kamlekar, Ravi Kanth; Tarafdar, Pradip K.; Swamy, Musti J.

    2010-01-01

    Recent studies show that N-, O-diacylethanolamines (DAEs) can be derived by the O-acylation of N-acylethanolamines (NAEs) under physiological conditions. Because the content of NAEs in a variety of organisms increases in response to stress, it is likely that DAEs may also be present in biomembranes. In view of this, a homologous series of DAEs with matched acyl chains (n = 10–20) have been synthesized and characterized. Transition enthalpies and entropies obtained from differential scanning calorimetry show that dry DAEs with even and odd acyl chains independently exhibit linear dependence on the chainlength. Linear least-squares analyses yielded incremental values contributed by each methylene group to the transition enthalpy and entropy and the corresponding end contributions. N-, O-Didecanoylethanolamine (DDEA), N-, O-dilauroylethanolamine (DLEA), and N-, O-dimyristoylethanolamine (DMEA) crystallized in the orthorhombic space group Pbc21 with four symmetry-related molecules in the unit cell. Single-crystal X-ray diffraction studies show that DDEA, DLEA, and DMEA are isostructural and adopt an L-shaped structure with the N-acyl chain and the central ethanolamine moiety being essentially identical to the structure of N-acylethanolamines, whereas the O-acyl chain is linear with all-trans conformation. In all three DAEs, the lipid molecules are organized in a bilayer fashion wherein the N-acyl and O-acyl chains from adjacent layers oppose each other. PMID:19597189

  12. First results on neutrinoless double beta decay of 130Te with the calorimetric CUORICINO experiment

    NASA Astrophysics Data System (ADS)

    Arnaboldi, C.; Artusa, D. R.; Avignone, F. T.; Balata, M.; Bandac, I.; Barucci, M.; Beeman, J. W.; Brofferio, C.; Bucci, C.; Capelli, S.; Capozzi, F.; Carbone, L.; Cebrian, S.; Cremonesi, O.; Creswick, R. J.; de Waard, A.; Farach, H. A.; Fascilla, A.; Fiorini, E.; Frossati, G.; Giuliani, A.; Gorla, P.; Haller, E. E.; McDonald, R. J.; Morales, A.; Norman, E. B.; Nucciotti, A.; Olivieri, E.; Palmieri, E.; Pasca, E.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Pobes, C.; Previtali, E.; Pyle, M.; Risegari, L.; Rosenfeld, C.; Sangiorgio, S.; Sisti, M.; Smith, A. R.; Torres, L.; Ventura, G.

    2004-04-01

    The first results are reported on the limit for neutrinoless double decay of 130Te obtained with the new bolometric experiment CUORICINO. The set-up consists of 44 cubic crystals of natural TeO2, 5 cm on the side and 18 crystals of 3×3×6 cm3. Four of these latter crystals are made with isotopically enriched materials: two in 128Te and two others in 130Te. With a sensitive mass of ∼40 kg, our array is by far the most massive running cryogenic detector to search for rare events. The array is operated at a temperature of ∼10 mK in a dilution refrigerator under a heavy shield in the Gran Sasso Underground Laboratory at a depth of about 3500 m.w.e. The counting rate in the region of neutrinoless double beta decay is ∼0.2 counts keV-1 kg-1 y-1, among the lowest in this type of experiment. No evidence for neutrinoless double beta decay is found with the present statistics obtained in about three months with a live time of 72%. The corresponding lower limit for the lifetime of this process is of 5.5×1023 years at 90% C.L. The corresponding limit for the effective neutrino mass ranges between 0.37 to 1.9 eV depending on the theoretically calculated nuclear matrix elements used. This constraint is the most restrictive one except those obtained with Ge diodes, and is comparable to them.

  13. Heavy metal effects on the metabolic activity of Elliptio complanata: A calorimetric method

    SciTech Connect

    Cheney, M.A.; Criddle, R.S.

    1996-03-01

    The effects of short time exposure to mercury (Hg{sup 2+}), cadmium (Cd{sup 2+}), and copper (Cu{sup 2+}) ions on the metabolic activity of gill tissue from the freshwater bivalve Elliptio complanata were investigated by isothermal calorimetry and respirometry. Metabolic heat rates were altered following exposure of gill tissue to these ions over the concentration range from 10{sup {minus}6} to 10{sup {minus}3} M. The effects of metal ions on metabolic heat rates were metal ion specific and time and concentration dependent. Treatment of tissue with low concentrations of Hg{sup 2+} and Cu{sup 2+} for short times caused stimulation of metabolic heat rates. Longer exposures and higher concentrations caused inhibition. Cadmium was inhibitory under all conditions tested. Treatment of mitochrondria isolated from gill and muscle tissues showed a similar pattern of stimulation of respiratory rate at low concentration and inhibition at higher concentration. Analysis of CO{sub 2} and O{sub 2} from the headspace gasses in the calorimeter ampule showed an enhancement of respiratory quotient (RQ, i.e., R{sub CO{sub 2}}/R{sub O{sub 2}} where R = rate) following addition of 10{sup {minus}3} M Cd{sup 2+} for 30 min. The microcalorimetric method proved to be a useful technique to assess toxicity of heavy metals on the gills of a freshwater bivalve. 12 refs., 7 figs., 3 tabs.

  14. Plate stamping of masterplates for the Tile-Cal hadronic calorimetric for ATLAS detector at CERN

    SciTech Connect

    Hill, N.F.; Petereit, E.; Wood, K.; Proudfoot, J.

    1996-05-16

    Various methods have been explored for the fabrication of the large trapezoidal plates used in the construction of the Tile-Cal hadronic calorimeter for ATLAS. The options include die stamping, laser cutting, waterjet cutting, plasma arc cutting, and a combination of machining and laser cutting. Very early in the program, the Argonne group began investigating the possibility of die stamping the master plates. At that time it was felt that two dies would be necessary to achieve the accuracy required. Quotations were received for dies for both the master and spacer plates. Concern was expressed by many members of the collaboration that due to the very precise tolerances required, die stamping, using standard dies, would not be adequate. Fine blanking techniques were felt to be adequate, but were cost prohibitive. Two methods were finally used for the initial cutting of prototype plates, laser cutting and die stamping. Only the die stamping, will be reviewed here.

  15. An Integrated Ultrafast Scanning Calorimetric and Micro Raman Spectroscopic Investigation of Polymer Crystallization

    NASA Astrophysics Data System (ADS)

    Zhou, Dongshan; Wei, Lai; Jiang, Jing; Xue, Gi; Wang, Xiaoliang

    2014-03-01

    Ultrafast differential scanning calorimetry (UFDSC) with scanning rate up to 1,000,000 K/s has already been used to study the kinetics of crystallization and phase transition of some polymers and liquid crystal. Recently, we developed stage type UFDSC (ST-UFDSC) with comparable controlled heating and cooling rates. ST-UFDSC enables sample treatment and measurement integrated with microstructural characterization. As an example, we investigated the Raman spectroscopy of PET at different crystallization stage obtained by programed rapid cooling and heating processes. Although the Raman spectroscopy is not acquired during rapid heat treatments, the structure is assumed to remain by ultrafast quench below the glass transition temperature, when the Raman spectroscopy is collected. We expect that the combination technique can be also used to investigate dynamic relaxation behaviors of metastable states obtained by ultrafast heat treatments. This work has been supported by NNSFC (Nos. 21027006 and 21274059) and 973 program, No. 2012CB821500).

  16. Exploring the antioxidant property of bioflavonoid quercetin in preventing DNA glycation: A calorimetric and spectroscopic study

    SciTech Connect

    Sengupta, Bidisa . E-mail: bidisa@fy.chalmers.se; Uematsu, Takashi; Jacobsson, Per; Swenson, Jan

    2006-01-06

    Reducing sugars for example glucose, fructose, etc., and their phosphate derivatives non-enzymatically glycate biological macromolecules (e.g., proteins, DNA and lipids) and is related to the production of free radicals. Here we present a novel study, using differential scanning calorimetry (DSC) along with UV/Vis absorption and photon correlation spectroscopy (PCS), on normal and glycated human placenta DNA and have explored the antioxidant property of the naturally occurring polyhydroxy flavone quercetin (3,3',4',5,7-pentahydroxyflavone) in preventing the glycation. The decrease in the absorption intensity of DNA in presence of sugars clearly indicates the existence of sugar molecules between the two bases of a base pair in the duplex DNA molecule. Variations were perceptible in the PCS relaxation profiles of normal and glycated DNA. The melting temperature of placenta DNA was decreased when glycated suggesting a decrease in the structural stability of the double-stranded glycated DNA. Our DSC and PCS data showed, for the first time, that the dramatic changes in the structural properties of glycated DNA can be prevented to a significant extent by adding quercetin. This study provides valuable insights regarding the structure, function, and dynamics of normal and glycated DNA molecules, underlying the manifestation of free radical mediated diseases, and their prevention using therapeutically active naturally occurring flavonoid quercetin.

  17. Calorimetric Study of Gradient Block-copolymers of Poly(butylacrylate) and Poly(methylmethacrylate)

    NASA Astrophysics Data System (ADS)

    Buzin, A. I.; Pyda, M.; Matyjaszewski, K.; Wunderlich, B.

    2002-03-01

    The miscibility and phase separation in the diblock (AB) and triblock (ABA) copolymers consisting of poly(butyl acrylate) (block B) and gradient copolymers of butyl acrylate and methyl methacrylate (block A) were investigated by means of conventional DSC as a function of the composition of the blocks A. In all copolymers studied, both blocks are presented by two separate glass transition temperatures. The low-temperature transition corresponds to devitrification of block B and is independent of composition and temperature is close to that of pure poly(butyl acrylate), while the higher transition corresponds to glass transition of the copolymeric block A, which decreases and broadens with increasing methylmethacrylate content in block A. The immiscible polymers are connected by chemical bonds, so that the mobilities of the phases influence each other. Shifts in the glass transition temperature and the broadening of the transitions as well as their asymmetry are discussed. --- Supported by NSF, Polymers Program, DMR-9703692, and the Div. of Mat. Sci., BES, DOE at ORNL, managed by UT-Batelle, LLC, for the U.S. Department of Energy, under contract number DOE-AC05-00OR22725.

  18. Calorimetric evidence for the liquid-crystalline state of lipids in a biomembrane.

    PubMed

    Steim, J M; Tourtellotte, M E; Reinert, J C; McElhaney, R N; Rader, R L

    1969-05-01

    Both membranes of Mycoplasma laidlawii and water dispersions of protein-free membrane lipids exhibit thermal phase transitions that can be detected by differential scanning calorimetry. The transition temperatures are lowered by increased unsaturation in the fatty acid residues, but in each case they are the same for membranes and lipids. The transitions resemble those observed for synthetic lipids in the lamellar phase in water, which arise from melting of the hydrocarbon chains within the phospholipid bilayers. Such melts are cooperative phenomena and would be greatly perturbed by apolar binding to protein. Thus the identity of membrane and lipid transition temperatures suggests that in the membranes, as in water, the lipids are in the bilayer conformation in which the hydrocarbon chains associate with each other rather than with proteins. Observations of morphological changes indicate that osmotic imbalance occurs when the membrane transition temperature exceeds the growth temperature, and that for transport processes to function properly the hydrocarbon chains must be in a liquid-like state. PMID:5257955

  19. Effect of anti-inflammatory drugs in phosphatidylcholine membranes: A fluorescence and calorimetric study

    NASA Astrophysics Data System (ADS)

    Lúcio, M.; Nunes, C.; Gaspar, D.; Gołębska, K.; Wisniewski, M.; Lima, J. L. F. C.; Brezesinski, G.; Reis, S.

    2009-03-01

    NSAIDs are the most prescribed drugs for inflammation, and their use is associated with severe gastrointestinal toxicity. This work focuses on the interaction of NSAIDs with membranes, specifically, on their ability to affect the lipid dynamic properties, since this may explain the compromising effects on the integrity of gastric barrier. Studies covered the assessment of drug-membrane/water partition coefficient and location by derivative spectroscopy and fluorescence quenching techniques and effects on membrane biophysics by DSC. Results indicate that the NSAIDs studied have membrane destabilizing effects, which could be transposed to similar effects in the stomach's phospholipid layer justifying their toxicity.

  20. A scanning calorimetric study of unfolding equilibria in homodimeric chicken gizzard tropomyosins.

    PubMed Central

    O'Brien, R; Sturtevant, J M; Wrabl, J; Holtzer, M E; Holtzer, A

    1996-01-01

    Using both circular dichroism (CD) and differential scanning calorimetry (DSC), several laboratories find that the thermal unfolding transitions of alpha alpha and beta beta homodimeric coiled coils of rabbit tropomyosin are multistate and display an overall unfolding enthalpy of near 300 kcal (mol dimer)(-1). In contrast, an extant CD study of beta beta and gamma gamma species of chicken gizzard tropomyosin concludes that their unfolding transitions are simple two-state transitions, with much smaller overall enthalpies (98 kcal mol(-1) for beta beta and 162 kcal mol(-1) for gamma gamma). However, these smaller enthalpies have been questioned, because they imply a concentration dependence of the melting temperatures that is far larger than observed by CD. We report here DSC studies of the unfolding of both beta beta and gamma gamma chicken gizzard homodimers. The results show that these transitions are very similar to those in rabbit tropomyosins in that 1) the overall unfolding enthalpy is near 300 kcal mol(-1); 2) the overall delta C(rho) values are significantly positive; 3) the various transitions are multistate, requiring at least two and as many as four domains to fit the DSC data. DSC studies are also reported on these homodimeric species of chicken gizzard tropomyosin with a single interchain disulfide cross-link. These results are also generally similar to those for the correspondingly cross-linked rabbit tropomyosins. PMID:9172766

  1. Hydration process of cement in the presence of a cellulosic additive. A calorimetric investigation.

    PubMed

    Ridi, Francesca; Fratini, Emiliano; Mannelli, Francesca; Baglioni, Piero

    2005-08-01

    In the cement industry, the extrusion technique is used to produce flat shapes with improved resistance to compression. Extrusion is a plastic-forming process that consists of forcing a highly viscous plastic mixture through a shaped die. The material should be fluid enough to be mixed and to pass through the die, and on the other hand, the extruded specimen should be stiff enough to be handled without changing in shape or cracking. These characteristics are industrially obtained by adding cellulosic polymers to the mixture. The aim of this work is to understand the action mechanism of these additives on the major pure phases constituting a typical Portland cement: tricalcium silicate (C(3)S), dicalcium silicate (C(2)S), tricalcium aluminate (C(3)A), and tetracalcium iron-aluminate (C(4)AF). In particular, a methylhydroxyethyl cellulose (MHEC) was selected from the best-performing polymers for further study. The effect of this additive on the hydration kinetics (rate constants, activation energies, and diffusional constants) was evaluated by means of differential scanning calorimetry (DSC) while the hydration products were studied by using thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). MHEC addition in calcium silicate pastes produces an increase in the induction time without affecting the nucleation-and-growth period. A less dense CSH gel was deduced from the diffusional constants in the presence of MHEC. Moreover, CSH laminar features and poorly structured hydrates were noted during the first hours of hydration. In the case of the aluminous phases, the additive inhibits the growth of stable cubic hydrated phases (C(3)AH(6)), with the advantage of the metastable hexagonal phases being formed in the earliest minutes of hydration. PMID:16852857

  2. Final Preparation of the CALorimetric Electron Telescope (CALET) for Launch to the International Space Station

    NASA Astrophysics Data System (ADS)

    Rauch, Brian; Calet Collaboration

    2015-04-01

    CALET has been delivered to the JAXA Tsukuba Space Center and is undergoing final preflight testing for launch to the ISS on HTV5 for installation on the Japanese Experiment Module - Exposed Facility (JEM-EF) with a target date in 2015. This Japanese-Italian-US astroparticle observatory consists of a main calorimeter (CAL) and a Gamma-ray Burst Monitor (CGBM) subsystem. The CAL is comprised from top to bottom of a charge detector (CHD) with two crossed layers of scintillator paddles, an imaging calorimeter (IMC) with planes of scintillating fibers interleaved with a total of 3 radiation lengths (X0) of tungsten, and a 27 X0 deep total absorption calorimeter (TASC) made of lead tungstate logs, which has the excellent energy resolution and imaging capabilities to resolve electrons, hadrons and photons. In a planned 5 year mission CALET will measure the combined cosmic ray electron and positron spectrum to 20 TeV, gamma rays to 10 TeV, nuclei 1 <= Z <= 40 to 1,000 TeV, and gamma-ray bursts between 7 keV and 20 MeV. CALET will look for signs of possible local astrophysical sources of cosmic ray electrons, search for dark matter signatures and probe the environment through which cosmic rays propagate from their source(s) to Earth. This research is supported by JAXA in Japan, ASI in Italy, and by NASA under Grant Number NNX11AE02G.

  3. A Simple Calorimetric Experiment that Highlights Aspects of Global Heat Retention and Global Warming

    ERIC Educational Resources Information Center

    Burley, Joel D.; Johnston, Harold S.

    2007-01-01

    In this laboratory experiment, general chemistry students measure the heating curves for three different systems: (i) 500 g of room-temperature water heated by a small desk lamp, (ii) 500 g of an ice-water mixture warmed by conduction with room-temperature surroundings, and (iii) 500 g of an ice-water mixture heated by a small desk lamp and by…

  4. 1H-NMR, dielectric and calorimetric studies of molecular motions in m-nitroaniline crystal

    NASA Astrophysics Data System (ADS)

    Szostak, M. Magdalena; Wójcik, Grażyna; Gallier, Jean; Bertault, Marcel; Freundlich, Piotr; Kołodziej, Hubert A.

    1998-04-01

    Spin-lattice relaxation time, T1, spin-lattice relaxation time in the rotating frame, T1 ρ, and the second moment of the resonance line measurements at 80 MHz and over the 190-380 K temperature range are reported for protons in the optically nonlinear material m-nitroaniline ( m-NA). T1 has also been measured for samples irradiated by low energy and low intensity radiation. The real and imaginary parts of electric permittivity as well as tan  δ have been recorded in the 80-380 K temperature range at frequencies ranging from 100 Hz to 1.0 MHz. DSC measurements have been performed in the 110-387 K temperature range. Two phase transitions have been found: A glassy to rotative transition at 160 K and a plastic to plastic transformation at 365 K. The main feature of the m-NA crystal is that its plasticity continues to grow as the temperature increases. The reorientations of phenyl rings, the -NH 2 group proton 180° jumps, the lattice distortions caused by anisotropic thermal expansion and the cooperative reorientations of big molecular aggregates are thought to be the reasons for phase transitions and for the subsequent intermolecular charge transfer. The results are discussed with respect to optical second harmonic generation and near-IR photochemical reaction found in the m-NA crystal.

  5. Calorimetric study on mechanically milled aluminum and multiwall carbon nanotube composites

    SciTech Connect

    Nayan, Niraj Murty, S.V.S.N.; Sharma, S.C.; Kumar, K. Sree; Sinha, P.P.

    2011-11-15

    Pure aluminum reinforced with carbon nanotube (CNT) composites have been prepared by high energy attritor milling up to 48 hrs. Differential Scanning Calorimetry (DSC) has been carried out to investigate apparent activation energy and order of the reaction between carbon nanotubes and aluminum by Kissinger equation and Crane equation under non-isothermal conditions. The DSC results clearly reveal that an exothermic reaction occurs before the melting of aluminum. The effect of milling time on the initiation of this exothermic reaction has been studied. The peak temperature of the reaction of carbon nanotubes and aluminum is found to depend on the heating rate during the continuous heating. Apparent activation energy was found to get doubled after milling for 36 hrs compared to 24 hrs milled samples. The mechanism of the reaction kinetics which depends on reaction order is instantaneous nucleation and one dimensional growth for both samples. Formation of Al{sub 4}C{sub 3} was confirmed by X-ray diffraction (XRD) of as-milled powders and after performing DSC of the milled powders. Highlights: {yields} Attritor milling used for processing Al-CNT composites. {yields} Powder morphology as a function of time studied. {yields} Apparent activation energy and order of the reaction calculated for Al{sub 4}C{sub 3} formation. {yields} Apparent activation energy increases two fold with increase in milling time from 24 to 36 hours.

  6. Multispectroscopic and calorimetric studies on the binding of the food colorant tartrazine with human hemoglobin.

    PubMed

    Basu, Anirban; Suresh Kumar, Gopinatha

    2016-11-15

    Interaction of the food colorant tartrazine with human hemoglobin was studied using multispectroscopic and microcalorimetric techniques to gain insights into the binding mechanism and thereby the toxicity aspects. Hemoglobin spectrum showed hypochromic changes in the presence of tartrazine. Quenching of the fluorescence of hemoglobin occurred and the quenching mechanism was through a static mode as revealed from temperature dependent and time-resolved fluorescence studies. According to the FRET theory the distance between β-Trp37 of hemoglobin and bound tartrazine was evaluated to be 3.44nm. Synchronous fluorescence studies showed that tartrazine binding led to alteration of the microenvironment around the tryptophans more in comparison to tyrosines. 3D fluorescence and FTIR data provided evidence for conformational changes in the protein on binding. Circular dichroism studies revealed that the binding led to significant loss in the helicity of hemoglobin. The esterase activity assay further complemented the circular dichroism data. Microcalorimetric study using isothermal titration calorimetry revealed the binding to be exothermic and driven largely by positive entropic contribution. Dissection of the Gibbs energy change proposed the protein-dye complexation to be dominated by non-polyelectrolytic forces. Negative heat capacity change also corroborated the involvement of hydrophobic forces in the binding process. PMID:27450339

  7. X-ray diffraction and calorimetric study of N-lignoceryl sphingomyelin membranes.

    PubMed Central

    Maulik, P. R.; Shipley, G. G.

    1995-01-01

    Differential scanning calorimetry and x-ray diffraction have been used to investigate hydrated multibilayers of N-lignoceryl sphingomyelin (C24:0-SM) in the hydration range 0-75 wt % H2O. Anhydrous C24:0-SM exhibits a single endothermic transition at 81.3 degrees C (delta H = 3.6 kcal/mol). At low hydration (12.1 wt % H2O), three different endothermic transitions are observed: low-temperature transition (T1) at 39.4 degrees C (transition enthalpy (delta H1) = 2.8 kcal/mol), intermediate-temperature transition (T2) at 45.5 degrees C, and high-temperature transition (T3) at 51.3 degrees C (combined transition enthalpy (delta H2 + 3) = 5.03 kcal/mol). On increasing hydration, all three transition temperatures of C24:0-SM decrease slightly to reach limiting values of 36.7 degrees C (T1), 44.4 degrees C (T2), and 48.4 degrees C (T3) at approximately 20 wt % H2O. At 22 degrees C (below T1), x-ray diffraction of C24:0-SM at different hydration levels shows two wide-angle reflections, a sharp one at 1/4.2 A-1 and a more diffuse one at 1/4.0 A-1 together with lamellar reflections corresponding to bilayer periodicities increasing from d = 65.4 A to a limiting value of 71.1 A. Electron density profiles show a constant bilayer thickness dp-p approximately 50 A. In contrast, at 40 degrees C (between T1 and T2) a single sharp wide-angle reflection at approximately 1/4.2 A-1 is observed. The lamellar reflections correspond to a larger bilayer periodicity (increasing from d = 69.3-80.2 A) and there is some increase in dp-p (52-56 A) with hydration. These structural parameters,together with calculated lipid thickness and molecular area considerations, suggest that the low temperature endotherm(T1) of hydrated C24:0-SM corresponds to a transition from a tilted, gel state (Gel I) with partially interdigitated chains to an untilted, or less tilted, gel state (Gel 11). At 600C (above T3), the usual liquid-crystalline La bilayer structure (d = 59.5-66.3A; dp p -46 A) is present at all hydrations. Comparison with the behavior of C18:0-SM indicates that the in equivalence of length of the sphingosine (C18) and lignoceryl (C24) chains results in a more complex gel phase polymorphism for the sphingosine (C18) and lignoceryl (C24) chains results in a more complex gel phase polymorphism for C24:0-SM. PMID:8580334

  8. Calorimetric detection of the conical terahertz radiation from femtosecond laser filaments in air

    NASA Astrophysics Data System (ADS)

    Houard, Aurélien; Liu, Yi; Mysyrowicz, André; Leriche, Bernadette

    2007-12-01

    The spectral distribution of the conical terahertz emission from a femtosecond laser filament in air is measured with a bolometric detector and a set of filters, confirming that the main part of the emission lies between 0.5 and 3THz. The efficiency of this terahertz emission is compared with that obtained in air via four wave mixing of femtosecond laser pulses at ω and 2ω in the presence of a plasma.

  9. Calorimetric Properties of Dehydrating Pollen (Analysis of a Desiccation-Tolerant and an Intolerant Species).

    PubMed Central

    Buitink, J.; Walters-Vertucci, C.; Hoekstra, F. A.; Leprince, O.

    1996-01-01

    The physical state of water in the desiccation-tolerant pollen of Typha latifolia L. and the desiccation-sensitive pollen of Zea mays L. was studied using differential scanning calorimetry in an attempt to further unravel the complex mechanisms of desiccation tolerance. Melting transitions of water were not observed at water content (wc) values less than 0.21 (T. latifolia) and 0.26 (Z. mays) g H2O/g dry weight. At moisture levels at which melting transitions were not observable, water properties could be characterized by changes in heat capacity. Three hydration regions could be distinguished with the defining wc values changing as a function of temperature. Shifts in baseline power resembling second-order transitions were observed in both species and were interpreted as glass-to-liquid transitions, the glass-transition temperatures being dependent on wc. Irrespective of the extent of desiccation tolerance, both pollens exhibited similar state diagrams. The viability of maize pollen at room temperature decreased gradually with the removal of the unfrozen water fraction. In maize, viability was completely lost before grains were sufficiently dried to enter into a glassy state. Apparently, the glassy state per se cannot provide desiccation tolerance. From the existing data, we conclude that, although no major differences in the physical behavior of water could be distinguished between desiccation-tolerant and -intolerant pollens, the physiological response to the loss of water varies between the two pollen types. PMID:12226289

  10. The CALorimetric Electron Telescope (CALET) Launch and Early On-Orbit Performance

    NASA Astrophysics Data System (ADS)

    Guzik, T. Gregory; Calet Collaboration

    2016-03-01

    The CALET space experiment, has been developed by collaborators in Japan, Italy and the United States, will study electrons to 20 TeV, gamma rays above 10 GeV and nuclei with Z =1 to 40 up to 1,000 TeV during a five-year mission on the International Space Station. The instrument consists of a particle charge identification module, a thin imaging calorimeter (3 r.l. in total) with tungsten plates interleaving scintillating fiber planes, and a thick calorimeter (27 r.l.) composed of lead tungstate logs. CALET has the depth, imaging capabilities and energy resolution for excellent separation between hadrons, electrons and gamma rays. The instrument was launched into orbit on August 19, 2015 and on August 25, 2015 was mounted as an attached payload on the International Space Station (ISS) Japanese Experiment Module - Exposed Facility (JEM-EF). The experiment has successfully completed on-orbit checkout and has now been transitioned to normal science operations. This presentation summarizes the instrument design, science goals and early on-orbit performance. This effort is supported by NASA in the United States, by JAXA in Japan, and ASI in Italy.

  11. Revisiting the glass transition and dynamics of supercooled benzene by calorimetric studies

    NASA Astrophysics Data System (ADS)

    Tu, Wenkang; Chen, Zeming; Li, Xiangqian; Gao, Yanqin; Liu, Riping; Wang, Li-Min

    2015-10-01

    The glass transition and dynamics of benzene are studied in binary mixtures of benzene with five glass forming liquids, which can be divided into three groups: (a) o-terphenyl and m-xylene, (b) N-butyl methacrylate, and (c) N,N-dimethylpropionamide and N,N-diethylformamide to represent the weak, moderate, and strong interactions with benzene. The enthalpies of mixing, ΔHmix, for the benzene mixtures are measured to show positive or negative signs, with which the validity of the extrapolations of the glass transition temperature Tg to the benzene-rich regions is examined. The extrapolations for the Tg data in the mixtures are found to converge around the point of 142 K, producing Tg of pure benzene. The fragility m of benzene is also evaluated by extrapolating the results of the mixtures, and a fragility m ˜ 80 is yielded. The obtained Tg and m values for benzene allow for the construction of the activation plot in the deeply supercooled region. The poor glass formability of benzene is found to result from the high melting point, which in turn leads to low viscosity in the supercooled liquid.

  12. Calorimetric Studies of Precipitation and Dissolution Kinetics in Aluminum Alloys 2219 and 7075

    NASA Astrophysics Data System (ADS)

    Papazian, John M.

    1982-05-01

    Differential scanning calorimetry (DSC) was used to study the kinetics of precipitation and dissolution of metastable and stable phases in aluminum alloys 2219 and 7075. A comparison of DSC scans obtained at heating rates of 1, 5, 10, and 20 K per minute showed that, during a DSC scan, the rates of precipitation of θ' and θ in 2219 and η' and η in 7075 were limited by their reaction kinetics. Likewise, the rates of dissolution of GP zones, θ' and η', were found to be dominated by kinetics. In contrast, the dissolution of θ and η was dominated by the thermodynamic equilibrium between these phases and the matrix. Analysis of the kinetically dominated reaction peaks and their dependence on heating rate and particle size showed that the GP zone dissolution reaction could best be described by a three-dimensional volume diffusion limited rate expression with an activation energy equal to that for diffusion. The rate of formation of θ' was best described by an Avrami expression with n = 1.1, indicating that nucleation was not the rate controlling step. A pronounced dependence of the θ' formation rate on prior plastic deformation was observed and ascribed to the influence of the matrix dislocation density on diffusivity.

  13. Non-Isothermal Calorimetric Studies of the Crystallization of Lithium Disilicate Glass

    NASA Technical Reports Server (NTRS)

    Ray, C. S.; Day, D. E.; Huang, W.; Narayan, K. Lakshmi; Cull, T. S.; Kelton, K. F.

    1996-01-01

    The influence of preannealing treatments on the polymorphic crystallization of lithium disilicate glasses is examined. As expected, glasses heated at different rates through the temperature range where there is significant nucleation develop widely different numbers of nuclei. This can dramatically influence the stability and transformation characteristics of the annealed glass. Non-isothermal differential scanning calorimetry (DSC) and differential thermal analysis (DTA) measurements are demonstrated to be useful to probe the nucleation behavior. The first systematic investigations of particle size effects on the non-isothermal transformation behavior are presented and discussed. Based on DTA and microscopy experiments, we show that small particles of lithium disilicate glasses crystallize primarily by surface crystallization. The relative importance of surface versus volume crystallization is examined by varying particle size, by introducing nucleating agents and by exposing glasses to atmospheres of different water content. These data are analyzed quantitatively using a numerical model developed in a second paper following in this volume.

  14. Fitting two- and three-site binding models to isothermal titration calorimetric data

    PubMed Central

    Brautigam, Chad A.

    2014-01-01

    As isothermal titration calorimetry (ITC) gains popularity for the characterization of enthalpies and equilibrium association constants of simple 1:1 biomolecular interactions, its use for more complex systems is growing. The method is increasingly used to study interactions in which a single binding partner (molecule “A”) interacts with multiple copies of a second partner (“B”); thus examinations of ABB and ABBB interactions are not uncommon. The structure of ITC data (commonly formatted as isotherms) has a strong bearing on the ability of the researcher to extract the necessary parameters from them. Usually, only 10-30 injections are recorded in a single ITC experiment. Even if replicates are performed, the data must support the extraction of up to twelve parameters from an ABBB system conducted in triplicate. Further, the refinement of some of the parameters is largely driven by only a subset of the data. The ability of ITC data to guide the deterministic estimation of these parameters may therefore be questioned. This work assesses the ability of both empirical and simulated ITC data of ABB and ABBB systems to support the simultaneous estimation of the desired thermodynamic parameters. The results demonstrate that multiphasic isotherms tend to (but do not always) support the estimation of multiple parameters. On the other hand, uniphasic data obtained from multi-site binding systems are more problematic. In all cases, a thorough exploration of how precisely the estimated parameters are specified by the data is justified. PMID:25484338

  15. Development of Thin Film Germanium-Gold Thermistors for Calorimetric Detection of Nuclear Radiation.

    NASA Astrophysics Data System (ADS)

    Wang, Xunxie

    1995-01-01

    The present work is to produce thin film semiconductor thermistors which can be directly fabricated on radiation absorbers to act as ultra low-mass, highly sensitive cryogenic phonon sensors for detecting single nuclear radiation interaction invents. The specific application envisioned for these devices is in the search for galactic Dark Matter, which is proposed to exist in the form of weakly interacting massive particles in the galaxy. Thin film Au doped Ge thermistors were directly fabricated on single crystal silicon absorbers using vacuum filament evaporation and microfabrication techniques. The fabrication procedure developed in the present work gives micron-scale thin film GeAu thermistors with highly reproducible characteristics. Electrical and thermal properties of thin film Ge_{rm 1-x}Au _{rm x} for 0.019 < x < 0.17 were studied between room temperature and 0.019K and in magnetic fields up to 4.0T. Measurements indicated that variable-range-hopping dominates the conductivity of GeAu thin film at temperatures below 10K. Metal-insulator transition of the film is found to occur for x > 0.17. The observed magnetoresistance is explained by using a field-dependent hopping exponent proposed in the present work combined with Mott's hopping conductivity theory. A new treatment of electrical field-induced nonlinearity in variable-range-hopping is also given which quantitatively reproduced the observed nonlinear resistivity. Electrical heat pulse and particle detection measurements showed that the total effective heat capacity of the device was dominated by the silicon absorber substrate at a bath temperature of 1.5 K and by electron system of the thermistor itself of the device when the bath temperatures were below 100 mK. Excellent responsivity of GeAu thin film calorimeters has been demonstrated in AC electrical pulse and nuclear radiation detection experiments. At optimal bias power, the responsivity (|DeltaV/ DeltaE|) of the present devices reaches 10^8 V/J at 1.5K and 1010 V/J at 0.02 K bath temperature.

  16. Thermodynamic properties of anthophyllite and talc: corrections and discussion of calorimetric data

    USGS Publications Warehouse

    Hemingway, B.S.

    1991-01-01

    Arithmetic errors in calculating heat capacity values (Krupka, 1984; Krupka et al, 1985a) for anthophyllite and several errors in the Hess cycles utilized to derive enthalpies of formation of anthophyllite and talc are identified, and revised values are reported. -from Author

  17. Calorimetric investigation of diclofenac drug binding to a panel of moderately glycated serum albumins.

    PubMed

    Indurthi, Venkata S K; Leclerc, Estelle; Vetter, Stefan W

    2014-08-01

    Glycation alters the drug binding properties of serum proteins and could affect free drug concentrations in diabetic patients with elevated glycation levels. We investigated the effect of bovine serum albumin glycation by eight physiologically relevant glycation reagents (glucose, ribose, carboxymethyllysine, acetoin, methylglyoxal, glyceraldehyde, diacetyl and glycolaldehyde) on diclofenac drug binding. We used this non-steroidal anti-inflammatory drug diclofenac as a paradigm for acidic drugs with high serum binding and because of its potential cardiovascular risks in diabetic patients. Isothermal titration calorimetry showed that glycation reduced the binding affinity Ka of serum albumin and diclofenac 2 to 6-fold by reducing structural rigidity of albumin. Glycation affected the number of drug binding sites in a glycation reagent dependent manner and lead to a 25% decrease for most reagent, expect for ribose, with decreased by 60% and for the CML-modification, increased the number of binding sites by 60%. Using isothermal titration calorimetry and differential scanning calorimetry we derived the complete thermodynamic characterization of diclofenac binding to all glycated BSA samples. Our results suggest that glycation in diabetic patients could significantly alter the pharmacokinetics of the widely used over-the-counter NSDAI drug diclofenac and with possibly negative implications for patients. PMID:24751671

  18. Effects of cyclosporine A on biomembranes. Vibrational spectroscopic, calorimetric and hemolysis studies.

    PubMed Central

    O'Leary, T J; Ross, P D; Lieber, M R; Levin, I W

    1986-01-01

    Cyclosporine A (CSA)-dipalmitoylphosphatidylcholine (DPPC) interactions were investigated using scanning calorimetry, infrared spectroscopy, and Raman spectroscopy. CSA reduced both the temperature and the maximum heat capacity of the lipid bilayer gel-to-liquid crystalline phase transition; the relationship between the shift in transition temperature and CSA concentration indicates that the peptide does not partition ideally between DPPC gel and liquid crystalline phases. This nonideality can be accounted for by excluded volume interactions between peptide molecules. CSA exhibited a similar but much more pronounced effect on the pretransition; at concentrations of 1 mol % CSA the amplitude of the pretransition was less than 20% of its value in the pure lipid. Raman spectroscopy confirmed that the effects of CSA on the phase transitions are not accompanied by major structural alterations in either the lipid headgroup or acyl chain regions at temperatures away from the phase changes. Both infrared and Raman spectroscopic results demonstrated that CSA in the lipid bilayer exists largely in a beta-turn conformation, as expected from single crystal x-ray data; the lipid phase transition does not induce structural alterations in CSA. Although the polypeptide significantly affects DPPC model membrane bilayers, CSA neither inhibited hypotonic hemolysis nor caused erythrocyte hemolysis, in contrast to many chemical agents that are believed to act through membrane-mediated pathways. Thus, agents, such as CSA, that perturb phospholipid phase transitions do not necessarily cause functional changes in cell membranes. PMID:3755063

  19. Calorimetric evidence for a mobile surface layer in ultrathin polymeric films: poly(2-vinyl pyridine).

    PubMed

    Madkour, Sherif; Yin, Huajie; Füllbrandt, Marieke; Schönhals, Andreas

    2015-10-28

    Specific heat spectroscopy was used to study the dynamic glass transition of ultrathin poly(2-vinyl pyridine) films (thicknesses: 405-10 nm). The amplitude and the phase angle of the differential voltage were obtained as a measure of the complex heat capacity. In a traditional data analysis, the dynamic glass transition temperature Tg is estimated from the phase angle. These data showed no thickness dependency on Tg down to 22 nm (error of the measurement of ±3 K). A derivative-based method was established, evidencing a decrease in Tg with decreasing thickness up to 7 K, which can be explained by a surface layer. For ultrathin films, data showed broadening at the lower temperature side of the spectra, supporting the existence of a surface layer. Finally, temperature dependence of the heat capacity in the glassy and liquid states changes with film thickness, which can be considered as a confinement effect. PMID:26324951

  20. Mixing properties of lyophilized protein systems: a spectroscopic and calorimetric study.

    PubMed

    Katayama, Derrick S; Carpenter, John F; Menard, Kevin P; Manning, Mark Cornell; Randolph, Theodore W

    2009-09-01

    The purpose of this study was to investigate the solid-state properties of lyophilized formulations of protein (ribonuclease A) containing sucrose or trehalose across a wide range of compositions, both in the presence or absence of hydroxyethylstarch (HES). Infrared spectroscopy reveals that the protein forms hydrogen bonds to sugars (sucrose or trehalose) as water is removed from the sample. The strength and/or number of hydrogen bonds in dried samples increase as the weight fraction of sugar increases. Significant deviations of glass transition temperatures (T(g)'s) from those predicted by free volume theory are seen in both protein-sugar systems. The behavior can be explained by formation of protein-sugar hydrogen bonds at the expense of self-interactions between the sugars. Attractive interactions between lyophilized ribonuclease A and HES were detected spectroscopically and from thermodynamic analysis of T(g) values, contrary to the view that HES is sterically hindered from interacting with the protein surface. Sucrose-HES interactions were much less favorable than trehalose-HES interactions, suggesting that phase separation in sugar/HES/protein mixtures would be more likely in the presence of sucrose than trehalose. Finally, the thermodynamics of mixing were investigated using differential scanning calorimetry (DSC) providing some of the first data for such solid protein sugar formulations with and without HES. In nearly all samples, positive excess enthalpy, excess entropy and excess free energy were observed, with the excess free energy being greater for samples containing sucrose rather than trehalose. Analysis of Flory-Huggins chi parameters suggests that phase separation between protein and excipients may be thermodynamically favored in these dried solid preparations. PMID:18623211

  1. Simultaneous Calorimetric, Dielectric, and SAXS/WAXS Experiments During Polymer Crystallization

    NASA Astrophysics Data System (ADS)

    Wurm, A.; Minakov, A. A.; Schick, C.

    As extensively described in Chaps. 5 and 7, high-intensity synchrotron radiation offers the possibility to perform simultaneously and in real time small, medium, and wide angle X-ray scattering (SAXS, MAXS, and WAXS, nobreak respectively). In order to understand a broad range of physical phenomena like, for example nucleation, crystallization, and other phase transitions in polymers, polymer-based nobreak composites, or in liquid crystals simultaneous experiments with a nobreak combination of different methods are useful. Due to different sample geometry and thermal nobreak conditions, it is usually difficult to compare the results of different individual experiments. As an important supplement to the classical techniques for studying crystallization like SAXS, WAXS, or differential scanning calorimetry, measurements which test molecular mobility like dielectric or mechanical spectroscopy are of interest during isothermal and non-isothermal crystallization. From such simultaneous experiments, we can learn about the existence of pre-ordered structures before formation of crystals, as detected by DSC or X-ray scattering. In this chapter, we present the development of a device for simultaneous measurements of electrical properties and SAXS/WAXS intensities, which was extended to a microcalorimeter and allows measuring thermal properties like heat capacity and thermal conductivity additionally at the same time and at the same sample volume.

  2. Calorimetric observation of the melting of free water nanoparticles at cryogenic temperatures.

    PubMed

    Hock, C; Schmidt, M; Kuhnen, R; Bartels, C; Ma, L; Haberland, H; van Issendorff, B

    2009-08-14

    We present an experimental study of the thermodynamics of free, size-selected water cluster anions consisting of 48 and 118 molecules. The measured caloric curves of the clusters are bulklike at low temperatures but show a well-defined, particle-size specific transition at 93+/-3 K for (H2O)48- and 118+/-3 K for (H2O)118-. At the transition temperature the heat capacity strongly increases, which marks the onset of melting. PMID:19792643

  3. Temperature-dependent infrared and calorimetric studies on arsenicals adsorption from solution to hematite nanoparticles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To address the lack of systematic and surface sensitive studies on the adsorption energetics of arsenic compounds on metal (oxyhydr)oxides, we conducted temperature-dependent ATR-FTIR studies for the adsorption of arsenate, monomethylarsonic acid, and dimethylarsinic acid on hematite nanoparticles a...

  4. A calorimetric investigation of recrystallization in aluminum magnesium silicon copper alloys

    NASA Astrophysics Data System (ADS)

    Abou Khatwa, Mohamed

    The recrystallization behavior of three Al--Mg--Si--Cu alloys with varying iron and manganese additions was studied by differential power scanning calorimetry under non-isothermal annealing conditions. The influence of cold deformation on the precipitation sequence and its interaction with recrystallization was also investigated. The DSC experiments were complemented by hardness measurements and microstructural studies by optical and electron microscopy. The DSC signals, after optimization of the baseline, were used for the calculation of the kinetic parameters of the recrystallization process. Two different modeling approaches based on global JMAK kinetics were implemented. The first approach utilizes the classical isothermal JMAK expression directly, while the second approach introduces a path variable related to the thermal history of the material in the JMAK description. Model-independent estimates of the activation energy were also evaluated using the Flynn-Wall-Ozawa integral isoconversion method. The results show that the initial stages of recrystallization are not affected by the preceding precipitation processes and recrystallization always follows the precipitation of the Q' phase. However, during recrystallization enhanced coarsening of the Q' phase takes place leading to its transformation to the more stable Q phase. The Q phase exerts a Zener pinning pressures on the migrating boundaries preventing the formation of an equilibrium grain structure. Moreover, for high Fe and Mn additions, discontinuous precipitation of Mg2Si overlaps with the end of recrystallization and exerts an additional pinning pressure on the boundaries. Varying the Fe and Mn content significantly affects the recrystallization kinetics. PSN is promoted in alloys with the higher Fe and Mn content and the recrystallization temperature shifts to lower values. The modeling results show that the recrystallization process conforms to the classical JMAK type behavior. The course of the reaction was reproduced successfully by the path variable approach and the evaluated activation energies were in good agreement with the isoconversional model-independent estimates. However, when the classical JMAK expression was applied directly to non-isothermal measurements, a dependency of the recrystallization process on thermal history was observed.

  5. X-ray diffraction and calorimetric study of N-lignoceryl sphingomyelin membranes.

    PubMed

    Maulik, P R; Shipley, G G

    1995-11-01

    Differential scanning calorimetry and x-ray diffraction have been used to investigate hydrated multibilayers of N-lignoceryl sphingomyelin (C24:0-SM) in the hydration range 0-75 wt % H2O. Anhydrous C24:0-SM exhibits a single endothermic transition at 81.3 degrees C (delta H = 3.6 kcal/mol). At low hydration (12.1 wt % H2O), three different endothermic transitions are observed: low-temperature transition (T1) at 39.4 degrees C (transition enthalpy (delta H1) = 2.8 kcal/mol), intermediate-temperature transition (T2) at 45.5 degrees C, and high-temperature transition (T3) at 51.3 degrees C (combined transition enthalpy (delta H2 + 3) = 5.03 kcal/mol). On increasing hydration, all three transition temperatures of C24:0-SM decrease slightly to reach limiting values of 36.7 degrees C (T1), 44.4 degrees C (T2), and 48.4 degrees C (T3) at approximately 20 wt % H2O. At 22 degrees C (below T1), x-ray diffraction of C24:0-SM at different hydration levels shows two wide-angle reflections, a sharp one at 1/4.2 A-1 and a more diffuse one at 1/4.0 A-1 together with lamellar reflections corresponding to bilayer periodicities increasing from d = 65.4 A to a limiting value of 71.1 A. Electron density profiles show a constant bilayer thickness dp-p approximately 50 A. In contrast, at 40 degrees C (between T1 and T2) a single sharp wide-angle reflection at approximately 1/4.2 A-1 is observed. The lamellar reflections correspond to a larger bilayer periodicity (increasing from d = 69.3-80.2 A) and there is some increase in dp-p (52-56 A) with hydration. These structural parameters,together with calculated lipid thickness and molecular area considerations, suggest that the low temperature endotherm(T1) of hydrated C24:0-SM corresponds to a transition from a tilted, gel state (Gel I) with partially interdigitated chains to an untilted, or less tilted, gel state (Gel 11). At 600C (above T3), the usual liquid-crystalline La bilayer structure (d = 59.5-66.3A; dp p -46 A) is present at all hydrations. Comparison with the behavior of C18:0-SM indicates that the in equivalence of length of the sphingosine (C18) and lignoceryl (C24) chains results in a more complex gel phase polymorphism for the sphingosine (C18) and lignoceryl (C24) chains results in a more complex gel phase polymorphism for C24:0-SM. PMID:8580334

  6. Laves phase in alloy 718 fusion zone — microscopic and calorimetric studies

    SciTech Connect

    Manikandan, S.G.K.; Sivakumar, D.; Prasad Rao, K.; Kamaraj, M.

    2015-02-15

    Microstructural characterization of alloy 718 fusion zone welded with both solid solution and age hardenable filler metal has been done. The microsegregation and the aging response were studied by employing three levels of weld cooling rate. Gas Tungsten Arc welding process was used. The fusion zone of solid solution filler metal has been responding to the aging treatment due to the weld process conditions and weld metal chemistry. However the weld metal composition was modified due to the higher molybdenum (Mo) content in solid solution filler metal. The effect of this modification on the phase reaction temperatures was studied and the same was compared with the conventional filler metal. - Graphical abstract: Display Omitted - Highlights: • Interdendritic segregation has been controlled by weld cooling rate. • Laves phase formation has been studied with cooling rate and weld metal chemistry. • Aging response with solid solution filler metal has been demonstrated. • Reduction in Laves phase and alloying element segregation has been confirmed. • Reaction temperatures were found modified because of Mo addition.

  7. First results on neutrinoless double beta decay of Te-130 with the calorimetric cuoricino experiment

    SciTech Connect

    Arnaboldi, C.; Artusa, D.R.; Avignone, F.T.; Balata, M.; Bandac, I.; Barucci, M.; Beeman, J.W.; Brofferio, C.; Bucci, C.; Capelli, S.; Capozzi, F.; Carbone, L.; Cebrian, S.; Cremonesi, O.; Creswick, R.J.; de Waard, A.; Farach, H.A.; Fascilla, A.; Fiorini, E.; Frossati, G.; Giuliani, A.; Gorla, P.; Haller, E.E.; McDonald, R.J.; Morales, A.; Norman, E.B.; Nucciotti, A.; Olivieri, E.; Palmieri, E.; Pasca, E.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Pobes, C.; Previtali, E.; Pyle, M.; Risegari, L.; Rosenfeld, C.; Sangiorgio, S.; Sisti, M.; Smith, A.R.; Torres, L.; Ventura, G.

    2003-12-04

    The first results are reported on the limit for neutrinoless double decay of {sup 130}Te obtained with the new bolometric experiment CUORICINO. The set-up consists of 44 cubic crystals of natural TeO{sub 2}, 5 cm on the side and 18 crystals of 3 x 3 x 6 cm{sup 3}. Four of these latter crystals are made with isotopically enriched materials: two in {sup 128}Te and two others in {sup 130}Te . With a sensitive mass of {approx}40 kg, our array is by far the most massive running cryogenic detector to search for rare events. The array is operated at a temperature of {approx}10 mK in a dilution refrigerator under a heavy shield in the Gran Sasso Underground Laboratory at a depth of about 3500 m.w.e. The counting rate in the region of neutrinoless double beta decay is {approx}0.2 counts keV{sup -1} kg{sup -1} year{sup -1}, among the lowest in this type of experiment. No evidence for neutrinoless double beta decay is found with the present statistics obtained in about three months with a live time of 72%. The corresponding lower limit for the lifetime of this process is of 5.5 x 10{sup 23} years at 90% C.L. The corresponding limit for the effective neutrino mass ranges between 0.37 to 1.9 eV depending on the theoretically calculated nuclear matrix elements used. This constraint is the most restrictive one except those obtained with Ge diodes, and is comparable to them.

  8. CALORIMETRIC PROPERTIES OF WATER AND TRIACYLGLYCEROLS IN FERN SPORES RELATING TO STORAGE AT CRYOGENIC TEMPERATURES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Storing spores is a promising method to conserve genetic diversity of ferns ex situ. Inappropriate water contents or damaging effects of triacylglycerol (TAG) crystallization may cause initial damage and deterioration with time in spores placed at -15 degrees C or liquid nitrogen temperatures. We us...

  9. A calorimetric measurement of the heat deposition in the vicinity of a spallation neutron target

    SciTech Connect

    Fischer, W.E.; Moritz, L.; Spitzer, H.; Thorson, I.M.

    1986-07-01

    An experiment to measure the heat deposition in various materials in the vicinity of a spallation neuron target is described. This experiment has been performed at the Thermal Neutron Facility, TRIUMF. In the analysis of the data, the contributions to the heat deposition from (n,..gamma..) capture processes, fast neutron, and prompt gamma-ray scattering are separated.

  10. Specific heat and electrical resistivity of niobium measured by subsecond calorimetric technique

    NASA Astrophysics Data System (ADS)

    Maglić, K. D.; Perović, N. Lj.; Vuković, G. S.; Zeković, Lj. P.

    1994-09-01

    This paper presents results of measurements of specific heat and electrical resistivity of niobium from ambient temperature to the experimental limit of the equipment which is close to 2500 K. The study used a contact thermometry variant of the millisecond resolution pulse calorimetry developed at the Institute of Nuclear Sciences VINČA. In the experiments exceeding 1000 K, thermocouple thermometry was supplemented with parallel pyrometric temperature measurements. This, together with application of tungsten; rhenium thermocouple thermometry, increased the temperature range of measurements to 2500 K. In the range where two thermometries overlap, data on the specimen emittance were also generated. Novelties in the method, the results on electrical resistivity. specific heat, hemispherical total emittance and normal spectral emittance of niobium, and accuracies attained in different property measurements are discussed.

  11. Time-resolved x-ray diffraction and calorimetric studies at low scan rates

    PubMed Central

    Tenchov, Boris G.; Yao, Haruhiko; Hatta, Ichiro

    1989-01-01

    The phase transitions in fully hydrated dipalmitoylphosphatidylcholine (DPPC) and DPPC/water/ethanol phases have been studied by lowangle time-resolved x-ray diffraction under conditions similar to those employed in calorimetry (scan rates 0.05-0.5°C/min and uniform temperature throughout the samples). This approach provides more adequate characterization of the equilibrium transition pathways and allows for close correlations between structural and thermodynamic data. No coexistence of the rippled gel (Pβ') and liquid-crystalline (Lα) phases was found in the main transition of DPPC; rather, a loss of correlation in the lamellar structure, observed as broadening of the lamellar reflections, takes place in a narrow temperature range of ∼100 mK at the transition midpoint. Formation of a long-living metastable phase, denoted by Pβ'(mst), differing from the initial Pβ' was observed in cooling direction by both x-ray diffraction and calorimetry. No direct conversion of Pβ'(mst) into Pβ' occurs for over 24 h but only by way of the phase sequence Pβ'(mst) → Lβ' → Pβ'. According to differential scanning calorimetry (DSC), the enthalpy of the Pβ'(mst)-Lα transition is by ∼5% lower than that of the Pβ'-Lα transition. The effects of ethanol (Rowe, E. S. 1983. Biochemistry. 22:3299-3305; Simon, S. A., and T. J. McIntosh. 1984. Biochim. Biophys. Acta 773:169-172) on the mechanism and reversibility of the DPPC main transition were clearly visualized. At ethanol concentrations inducing formation of interdigitated gel phase, the main transition proceeds through a coexistence of the initial and final phases over a finite temperature range. During the subtransition in DPPC recorded at scan rate 0.3°C/min, a smooth monotonic increase of the lamellar spacing from its subgel (Lc) to its gel (Lβ') phase value takes place. The width of the lamellar reflections remains unchanged during this transformation. This provides grounds to propose a “sequential” relaxation mechanism for the subgel-gel transition which is not accompanied by growth of domains of the final phase within the initial one. PMID:19431747

  12. Time-resolved x-ray diffraction and calorimetric studies at low scan rates

    PubMed Central

    Yao, Haruhiko; Hatta, Ichiro; Koynova, Rumiana; Tenchov, Boris

    1992-01-01

    The phase transitions of dipalmitoylphosphatidylethanolamine (DPPE) in excess water have been examined by low-angle time-resolved x-ray diffraction and calorimetry at low scan rates. The lamellar subgel/lamellar liquid-crystalline (Lc → Lα), lamellar gel/lamellar liquid-crystalline (Lβ → Lα), and lamellar liquid-crystalline/lamellar gel (Lα → Lβ) phase transitions proceed via coexistence of the initial and final phases with no detectable intermediates at scan rates 0.1 and 0.5°C/min. At constant temperature within the region of the Lβ → Lα transition the ratio of the two coexisting phases was found to be stable for over 30 min. The state of stable phase coexistence was preceded by a 150-s relaxation taking place at constant temperature after termination of the heating scan in the transition region. While no intermediate structures were present in the coexistence region, a well reproducible multipeak pattern, with at least four prominent heat capacity peaks separated in temperature by 0.4-0.5°C, has been observed in the cooling transition (Lα → Lβ) by calorimetry. The multipeak pattern became distinct with an increase of incubation time in the liquid-crystalline phase. It was also clearly resolved in the x-ray diffraction intensity versus temperature plots recorded at slow cooling rates. These data suggest that the equilibrium state of the Lα phase of hydrated DPPE is represented by a mixture of domains that differ in thermal behavior, but cannot be distinguished structurally by x-ray scattering. Imagesp689-aFIGURE 9 PMID:19431820

  13. A neutron-X-ray, NMR and calorimetric study of glassy Probucol synthesized using containerless techniques

    NASA Astrophysics Data System (ADS)

    Weber, J. K. R.; Benmore, C. J.; Tailor, A. N.; Tumber, S. K.; Neuefeind, J.; Cherry, B.; Yarger, J. L.; Mou, Q.; Weber, W.; Byrn, S. R.

    2013-10-01

    Acoustic levitation was used to trap 1-3 mm diameter drops of Probucol and other pharmaceutical materials in containerless conditions. Samples were studied in situ using X-ray diffraction and ex situ using neutron diffraction, NMR and DSC techniques. The materials were brought into non-equilibrium states by supersaturating solutions or by supercooling melts. The glass transition and crystallization temperatures of glassy Probucol were 29 ± 1 and 71 ± 1 °C respectively. The glassy form was stable with a shelf life of at least 8 months. A neutron/X-ray difference function of the glass showed that while molecular sub-groups remain rigid, many of the hydrogen correlations observed in the crystal become smeared out in the disordered material. The glass is principally comprised of slightly distorted Form I Probucol molecules with disordered packing rather than large changes in the individual molecular structure. Avoiding surface contact-induced nucleation provided access to highly non-equilibrium phases and enabled synthesis of phase-pure glasses.

  14. Determination of uranium in zircon

    USGS Publications Warehouse

    Cuttitta, F.; Daniels, G.J.

    1959-01-01

    A routine fluorimetric procedure is described for the determination of trace amounts of uranium in zircon. It employs the direct extraction of uranyl nitrate with ethyl acetate using phosphate as a retainer for zirconium. Submicrogram amounts or uranium are separated in the presence of 100,000 times the amount of zirconium. The modified procedure has been worked out using synthetic mixtures of known composition and zircon. Results of analyses have an accuracy of 97-98% of the contained uranium and a standard deviation of less than 2.5%. ?? 1959.

  15. Liquid chromatographic determination of water

    DOEpatents

    Fortier, N.E.; Fritz, J.S.

    1990-11-13

    A sensitive method for the determination of water in the presence of common interferences is presented. The detection system is based on the effect of water on the equilibrium which results from the reaction aryl aldehydes, such as cinnamaldehyde and methanol in the eluent to form cinnamaldehyde dimethylacetal, plus water. This equilibrium is shifted in a catalytic atmosphere of a hydrogen ion form past column reactor. The extent of the shift and the resulting change in absorbance are proportional to the amount of water present. 1 fig.

  16. Liquid chromatographic determination of water

    DOEpatents

    Fortier, Nancy E.; Fritz, James S.

    1990-11-13

    A sensitive method for the determination of water in the presence of common interferences is presented. The detection system is based on the effect of water on the equilibrium which results from the reaction aryl aldehydes, such as cinnamaldehyde and methanol in the eluent to form cinnamaldehyde dimethylacetal, plus water. This equilibrium is shifted in a catalytic atmosphere of a hydrogen ion form past column reactor. The extent of the shift and the resulting change in absorbance are proportional to the amount of water present.

  17. Calibration effects on orbit determination

    NASA Technical Reports Server (NTRS)

    Madrid, G. A.; Winn, F. B.; Zielenbach, J. W.; Yip, K. B.

    1974-01-01

    The effects of charged particle and tropospheric calibrations on the orbit determination (OD) process are analyzed. The calibration process consisted of correcting the Doppler observables for the media effects. Calibrated and uncalibrated Doppler data sets were used to obtain OD results for past missions as well as Mariner Mars 1971. Comparisons of these Doppler reductions show the significance of the calibrations. For the MM'71 mission, the media calibrations proved themselves effective in diminishing the overall B-plane error and reducing the Doppler residual signatures.

  18. Determinants of internet poker adoption.

    PubMed

    Philander, Kahlil S; Abarbanel, B Lillian

    2014-09-01

    In nearly all jurisdictions, adoption of a new form of gambling has been a controversial and contentious subject. Online gambling has been no different, though there are many aspects that affect online gambling that do not appear in the brick and mortar environment. This study seeks to identify whether demographic, economic, political, technological, and/or sociological determinants contribute to online poker gambling adoption. A theoretical discussion of these categories' importance to online poker is provided and exploratory empirical analysis is used to examine their potential validity. The analysis revealed support for all of the proposed categories of variables thought to be predictive of online gambling legality. PMID:23661279

  19. Methods to determine aerobic endurance.

    PubMed

    Bosquet, Laurent; Léger, Luc; Legros, Patrick

    2002-01-01

    Physiological testing of elite athletes requires the correct identification and assessment of sports-specific underlying factors. It is now recognised that performance in long-distance events is determined by maximal oxygen uptake (V(2 max)), energy cost of exercise and the maximal fractional utilisation of V(2 max) in any realised performance or as a corollary a set percentage of V(2 max) that could be endured as long as possible. This later ability is defined as endurance, and more precisely aerobic endurance, since V(2 max) sets the upper limit of aerobic pathway. It should be distinguished from endurance ability or endurance performance, which are synonymous with performance in long-distance events. The present review examines methods available in the literature to assess aerobic endurance. They are numerous and can be classified into two categories, namely direct and indirect methods. Direct methods bring together all indices that allow either a complete or a partial representation of the power-duration relationship, while indirect methods revolve around the determination of the so-called anaerobic threshold (AT). With regard to direct methods, performance in a series of tests provides a more complete and presumably more valid description of the power-duration relationship than performance in a single test, even if both approaches are well correlated with each other. However, the question remains open to determine which systems model should be employed among the several available in the literature, and how to use them in the prescription of training intensities. As for indirect methods, there is quantitative accumulation of data supporting the utilisation of the AT to assess aerobic endurance and to prescribe training intensities. However, it appears that: there is no unique intensity corresponding to the AT, since criteria available in the literature provide inconsistent results; and the non-invasive determination of the AT using ventilatory and heart rate

  20. Crystal face temperature determination means

    DOEpatents

    Nason, D.O.; Burger, A.

    1994-11-22

    An optically transparent furnace having a detection apparatus with a pedestal enclosed in an evacuated ampule for growing a crystal thereon is disclosed. Temperature differential is provided by a source heater, a base heater and a cold finger such that material migrates from a polycrystalline source material to grow the crystal. A quartz halogen lamp projects a collimated beam onto the crystal and a reflected beam is analyzed by a double monochromator and photomultiplier detection spectrometer and the detected peak position in the reflected energy spectrum of the reflected beam is interpreted to determine surface temperature of the crystal. 3 figs.