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Sample records for xvi calorimetric determination

  1. A calorimetric method to determine water activity

    NASA Astrophysics Data System (ADS)

    Björklund, Sebastian; Wadsö, Lars

    2011-11-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  3. 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.

  4. 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 ∗.

  5. 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.

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

    NASA Astrophysics Data System (ADS)

    Ornellas, D. L.

    1982-04-01

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

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

    PubMed

    Tjahjono, Martin; Widjaja, Effendi; Garland, Marc

    2009-06-02

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

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

    PubMed

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

    2009-11-05

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

  12. Electronic calorimetric computer

    NASA Technical Reports Server (NTRS)

    Heckelman, J. D.

    1968-01-01

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

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

    PubMed

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

    2014-11-20

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

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

    NASA Astrophysics Data System (ADS)

    Robertson, R. G. H.

    2015-03-01

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

  15. 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.

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

    SciTech Connect

    Casas, L. M.

    2009-12-15

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

  17. Calorimetric determination of rate constants and enthalpy changes for zero-order reactions.

    PubMed

    Almeida e Sousa, Luis; Beezer, Anthony E; Hansen, Lee D; Clapham, David; Connor, Joseph A; Gaisford, Simon

    2012-06-07

    Calorimetry is a general method for determination of the rates of zero-order processes, but analysis of the data for the rate constant and reaction enthalpy is difficult because these occur as a product in the rate equation so evaluation of one requires knowledge of the other. Three methods for evaluation of both parameters, without prior knowledge, are illustrated with examples and compared with literature data. Method 1 requires the reaction to be studied in two buffers with different enthalpies of ionization. Method 2 is based on calculation of reaction enthalpy from group additivity functions. Method 3 applies when reaction progresses to completion. The methods are applied to the enzymatic hydrolysis of urea, the hydrolysis of acetylsalicylic acid, and the photodegradation of nifedipine, respectively.

  18. 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

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

    PubMed Central

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

    2007-01-01

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

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

    PubMed

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

    2007-05-25

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

  1. 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

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

    PubMed Central

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

    2005-01-01

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

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

    PubMed

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

    2004-05-01

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

  4. 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.

  5. 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.

  6. 77 FR 43640 - Social Security Ruling, SSR 12-2p; Titles II and XVI: Evaluation of Fibromyalgia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-25

    ... ADMINISTRATION Social Security Ruling, SSR 12-2p; Titles II and XVI: Evaluation of Fibromyalgia AGENCY: Social... determinable impairment of fibromyalgia, and how we evaluate fibromyalgia in disability claims and continuing... Interpretation Ruling Titles II and XVI: Evaluation of Fibromyalgia Purpose: This Social Security Ruling...

  7. Determination of electronic stopping powers of 0.05-1 MeV/u 131Xe ions in C-, Ni- and Au-absorbers with calorimetric low temperature detectors

    NASA Astrophysics Data System (ADS)

    Echler, A.; Egelhof, P.; Grabitz, P.; Kettunen, H.; Kraft-Bermuth, S.; Laitinen, M.; Müller, K.; Rossi, M.; Trzaska, W. H.; Virtanen, A.

    2017-01-01

    A new experimental system for precise determination of electronic stopping powers of heavy ions has been set up at the accelerator laboratory of the University of Jyväskylä. The new setup, combining an established B-ToF system and an array of calorimetric low temperature detectors (CLTDs), has been used for the determination of electronic stopping powers of 0.05-1 MeV/u 131Xe ions in carbon, nickel and gold. Thereby advantage of the improved linearity and energy resolution of CLTDs as compared to the previously used ionization detector was taken to reduce energy calibration errors and to increase sensitivity for the energy loss determination, in particular at very low energies. The total uncertainties of 3-4% for C- and Ni-targets, and 5-7% for Au-targets, respectively, are dominated by the target properties, i.e. thickness determination and inhomogeneities. The results are compared to data from literature and to predictions of different theoretical computer codes. In the high energy part of the examined energy range the results are in good agreement with previously published data, while new stopping power data for very heavy ions in different Z2-materials have been obtained at lower energies. Moreover, unexpectedly strong channeling effects for the transmission of the 131Xe ions in thin, partly polycrystalline nickel and gold target foils have been observed and investigated.

  8. 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).

  9. 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.

  10. 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.

  11. Calorimetric determination of the absorbed dose to water for medium-energy x-rays with generating voltages from 70 to 280 kV.

    PubMed

    Krauss, A; Büermann, L; Kramer, H-M; Selbach, H-J

    2012-10-07

    For medium energy x-rays produced with tube voltages from 70 to 280 kV, the absorbed dose to water, D(w), has been determined by means of water calorimetry with relative standard uncertainties ranging from 0.45% to 0.98% at 280 and 70 kV. The results were confirmed by Monte Carlo calculations, in which the ratios of D(w) at 5 cm depth in a reference water phantom to the air kerma free in air, K(a), at the same point in space were compared to the corresponding ratios determined experimentally. The general agreement between measurement and calculation was better than 1%. These results confirm earlier investigations in which the absorbed dose to graphite was determined by means of a graphite extrapolation chamber. For the Monte Carlo calculations, an attempt was made to present a complete uncertainty budget, taking into account type B contributions also.

  12. Calorimetric Measurements of Liquid Al-Zn Alloys

    NASA Astrophysics Data System (ADS)

    Dębski, Adam; Gąsior, Władysław; Szmit, Katarzyna

    2016-10-01

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

  13. [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.

  14. 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.

  15. 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

  16. Thermal Analysis of Calorimetric Systems

    NASA Astrophysics Data System (ADS)

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

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

  17. Measurement of the calorimetric energy scale in MINOS

    SciTech Connect

    Hartnell, Jeffrey J.

    2005-01-01

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

  18. 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.

  19. 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.

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

    NASA Astrophysics Data System (ADS)

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

    1999-12-01

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

  1. 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.

  2. Comparison and qualification of FFTF calorimetric methods

    SciTech Connect

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

    1981-01-01

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

  3. Calorimetric Thermometry of Meteoritic Troilite: Early Reconnaissance

    NASA Astrophysics Data System (ADS)

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

    1993-07-01

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

  4. 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.

  5. Calorimetric sensors for energy deposition measurements

    SciTech Connect

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

    1998-12-31

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

  6. 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.

  7. Adaptive measurement control for calorimetric assay

    SciTech Connect

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

    1994-10-01

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

  8. 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.

  9. 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.

  10. 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

  11. Four-core optical fiber as a calorimetric gauge.

    PubMed

    Güvenç, Sema; Gökbulut, Belkıs; Kösoğlu, Gülşen; Yüksel, Heba; Inci, Mehmet Naci

    2016-11-10

    A four-core optical fiber is demonstrated as a calorimetric gauge for investigation of one-dimensional heat transfer measurements. Transient heat pulses from a Nd:YAG laser of 600 ms duration with a repetition rate of the order of 10 s are delivered onto the cleaved distal end face of the four-core fiber, aiming at one of the single cores only, which cause an optical path length difference between four guiding cores due to the temperature-induced change in the index of refraction and physical length of the targeted fiber core of concern. This results in a shift in the fringe pattern, which is operated in the reflection scheme. A phase shift of 0.43±0.015  rad is measured with a CMOS camera for 40 mW pulses. The thermal heat diffusion length in the selected fiber core is determined to be 2.8 mm, which contains 10.9±0.38  kJ/m2s heat, causing a temperature rise of 1.43±0.05  K.

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

    PubMed

    Pinto, Susana S; Diogo, Hermínio P

    2008-12-01

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

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

    PubMed

    Kaya, H; Chan, H S

    2000-09-01

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

  14. Absolute calorimetric calibration of low energy brachytherapy sources

    NASA Astrophysics Data System (ADS)

    Stump, Kurt E.

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

  15. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... activities that include special interest clubs, physical activities, student government, and cultural affairs... 25 Indians 1 2013-04-01 2013-04-01 false Standard XVI-Student activities. 36.43 Section 36.43... § 36.43 Standard XVI—Student activities. All schools shall provide and maintain a well-balanced...

  16. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... activities that include special interest clubs, physical activities, student government, and cultural affairs... 25 Indians 1 2010-04-01 2010-04-01 false Standard XVI-Student activities. 36.43 Section 36.43... § 36.43 Standard XVI—Student activities. All schools shall provide and maintain a well-balanced...

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... activities that include special interest clubs, physical activities, student government, and cultural affairs... 25 Indians 1 2012-04-01 2011-04-01 true Standard XVI-Student activities. 36.43 Section 36.43... § 36.43 Standard XVI—Student activities. All schools shall provide and maintain a well-balanced...

  18. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... activities that include special interest clubs, physical activities, student government, and cultural affairs... 25 Indians 1 2014-04-01 2014-04-01 false Standard XVI-Student activities. 36.43 Section 36.43... § 36.43 Standard XVI—Student activities. All schools shall provide and maintain a well-balanced...

  19. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... activities that include special interest clubs, physical activities, student government, and cultural affairs... 25 Indians 1 2011-04-01 2011-04-01 false Standard XVI-Student activities. 36.43 Section 36.43... § 36.43 Standard XVI—Student activities. All schools shall provide and maintain a well-balanced...

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

    DTIC Science & Technology

    1975-07-30

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

  1. 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 Cp(T) measurements and calculations were performed at continuous scanning in the temperature range 20-800 °C. 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 Cp(T) 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°C.

  2. Calorimetric Determination of Thermodynamic Stability of MAX and MXene Phases

    SciTech Connect

    Sharma, Geetu; Naguib, Michael; Feng, Dawei; Gogotsi, Yury; Navrotsky, Alexandra

    2016-11-19

    MXenes are layered two-dimensional materials with exciting properties useful to a wide range of energy applications. They are derived from ceramics (MAX phases) by leaching, and their properties reflect their resulting complex compositions which include intercalating cations and anions and water. It is likely that their thermodynamic stability is linked to these functional groups but has not yet been addressed by quantitative experimental measurements. We also report enthalpies of formation from the elements at 25 °C measured using high temperature oxide melt solution calorimetry for a layered Ti–Al–C MAX phase, and the corresponding Ti–C based MXene. The thermodynamic stability of the Ti3C2Tx MXene (Tx stands for anionic surface moieties, and intercalated cations) was assessed by calculating the enthalpy of reaction of the MAX phase (ideal composition Ti3AlC2) to form MXene. The very exothermic enthalpy of reaction confirms the stability of MXene in an aqueous environment. The surface terminations (O, OH, and F) and cations (Li) chemisorbed on the surface and intercalated in the interlayers play a major role in the thermodynamic stabilization of MXene. Our findings help in understanding and potentially improving properties and performance by characterizing the energetics of species binding to MXene surfaces during synthesis and in energy storage, water desalination, and other applications.

  3. Calorimetric Determination of Thermodynamic Stability of MAX and MXene Phases

    DOE PAGES

    Sharma, Geetu; Naguib, Michael; Feng, Dawei; ...

    2016-11-19

    MXenes are layered two-dimensional materials with exciting properties useful to a wide range of energy applications. They are derived from ceramics (MAX phases) by leaching, and their properties reflect their resulting complex compositions which include intercalating cations and anions and water. It is likely that their thermodynamic stability is linked to these functional groups but has not yet been addressed by quantitative experimental measurements. We also report enthalpies of formation from the elements at 25 °C measured using high temperature oxide melt solution calorimetry for a layered Ti–Al–C MAX phase, and the corresponding Ti–C based MXene. The thermodynamic stability ofmore » the Ti3C2Tx MXene (Tx stands for anionic surface moieties, and intercalated cations) was assessed by calculating the enthalpy of reaction of the MAX phase (ideal composition Ti3AlC2) to form MXene. The very exothermic enthalpy of reaction confirms the stability of MXene in an aqueous environment. The surface terminations (O, OH, and F) and cations (Li) chemisorbed on the surface and intercalated in the interlayers play a major role in the thermodynamic stabilization of MXene. Our findings help in understanding and potentially improving properties and performance by characterizing the energetics of species binding to MXene surfaces during synthesis and in energy storage, water desalination, and other applications.« less

  4. 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

  5. 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

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

    DOE PAGES

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

    2015-10-22

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

  7. 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.

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

    PubMed

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

    2009-10-01

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

  9. 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.

  10. Calorimetric measurement of work for a driven harmonic oscillator

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2004-11-01

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

  12. 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.

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

    PubMed

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

    2016-12-01

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

  14. Calorimetric Aerogel Collectors/Detectors of Hypervelocity Dust Grains

    NASA Astrophysics Data System (ADS)

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

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

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

    NASA Astrophysics Data System (ADS)

    Liu, Qingyuan; Navrotsky, Alexandra

    2007-04-01

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

  16. 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.

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

    PubMed

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

    2015-12-07

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

  18. Unilateral NMR study of a XVI century wall painted

    NASA Astrophysics Data System (ADS)

    Proietti, N.; Capitani, D.; Rossi, E.; Cozzolino, S.; Segre, A. L.

    2007-06-01

    Wall paintings in the XVI century Serra Chapel in the "Chiesa di Nostra Signora del Sacro Cuore" Rome, have been studied using unilateral NMR. In order to map the distribution of moisture content in the wall painted, a large number of Hahn echo measurements, covering large areas of the wall painting were performed. Because the intensity of the Hahn echo is proportional to the amount of moisture in the area under study, the experimental data were transformed into 2D gradient colour maps which allowed an easy visualization of the moisture content of the wall. The state of conservation of the wall painting was monitored using T2 measurements specially with regards to outcropping salt.

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

    PubMed

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

    2007-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

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

    PubMed

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

    2005-08-19

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

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

    PubMed

    McIlvaine, P; Langerman, N

    1977-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

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

    PubMed

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

    2007-03-22

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

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

    PubMed

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

    2009-11-15

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

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

    PubMed

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

    2010-11-15

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

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

    NASA Astrophysics Data System (ADS)

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

    2005-05-01

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

  8. 20 CFR 416.1535 - Services in a proceeding under title XVI of the Act.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Services in a proceeding under title XVI of the Act. 416.1535 Section 416.1535 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Representation of Parties § 416.1535 Services in...

  9. American Press Coverage of the Execution of Louis XVI: A Lesson Strategy for Gauging Opinion.

    ERIC Educational Resources Information Center

    Lankiewicz, Donald

    1985-01-01

    In this unit of study high school students read and discuss U.S. newspaper articles reporting the trial and execution of the French king Louis XVI. Students look for key words and phrases that might indicate a subtle favorable or unfavorable opinion. (RM)

  10. 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.

  11. THE ISLANDS PROJECT. I. ANDROMEDA XVI, AN EXTREMELY LOW MASS GALAXY NOT QUENCHED BY REIONIZATION

    SciTech Connect

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

    2016-03-10

    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){sub 0} = 23.72 ± 0.09 mag, which is marginally larger than previous estimates based on the tip of the red giant branch.

  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

    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.

  14. 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.

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

    USGS Publications Warehouse

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

    1983-01-01

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

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

    SciTech Connect

    Deborah A. Harris

    2003-08-13

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

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

    PubMed

    Sultan, Nabil Ali Mohammed; Swamy, Musti J

    2005-05-01

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

  18. 78 FR 22361 - Social Security Ruling, SSR 13-1p; Titles II and XVI: Agency Processes for Addressing Allegations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-15

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION Social Security Ruling, SSR 13-1p; Titles II and XVI: Agency Processes for Addressing Allegations of Unfairness, Prejudice, Partiality, Bias, Misconduct, or Discrimination by Administrative...

  19. 78 FR 9987 - Social Security Ruling, SSR 13-1p; Titles II and XVI: Agency Processes for Addressing Allegations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-12

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION Social Security Ruling, SSR 13-1p; Titles II and XVI: Agency Processes for Addressing Allegations of Unfairness, Prejudice, Partiality, Bias, Misconduct, or Discrimination by Administrative...

  20. 78 FR 8217 - Social Security Ruling, SSR 13-1p; Titles II and XVI: Agency Processes for Addressing Allegations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-05

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION Social Security Ruling, SSR 13-1p; Titles II and XVI: Agency Processes for Addressing Allegations of Unfairness, Prejudice, Partiality, Bias, Misconduct, or Discrimination by Administrative...

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  2. 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

  3. 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

    2014-04-24

    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.

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

    PubMed

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

    2007-03-14

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

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

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Gonzalez Padilla, Francisco; Harrowell, Peter R.

    2001-03-01

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

  7. 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.

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

    DTIC Science & Technology

    1987-04-01

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

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

    PubMed

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

    2007-09-13

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

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

    SciTech Connect

    Cremers, Teresa L; Sampson, Thomas E

    2010-01-01

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

  11. 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.

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

    PubMed

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

    2013-05-08

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

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

    PubMed

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

    2010-06-01

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

  14. The Explorer XVI Micrometeoroid Satellite Description and Preliminary Results for the Period December 16, 1962 Through January 13, 1963

    NASA Technical Reports Server (NTRS)

    Hastings, E. C., Jr.

    1963-01-01

    Explorer XVI (1962 Beta Chi l) data that have been analyzed for the period between December 16, 1962 (launch date), and January 13, 1963, indicate that the orbit achieved was close to the predicted orbit. Ten punctures of annealed 0.001-inch-thick beryllium-copper have been used to determine a puncture rate of 0.035 per square foot per day in this material. One puncture of a 0.002-inch-thick sample has also occurred in this period. A tentative evaluation of the puncture rate for the 0.001-inch beryllium-copper in terms of the rate for an equivalent thickness of aluminum has been attempted, and the result has been compared with two different puncture rate estimates. The three micrometeoroid impact detecting systems are operating. Counting rates for the high- and low-sensitivity systems were close to anticipated values near the end of one week. Two of the 0.001-inch-steel-covered grid detectors have been punctured, but none of the 0.003- or 0.006-inch-steel-covered grid detectors have indicated punctures. One of the cadmium sulfide cells indicates three punctures of the 0.00025-inch Mylar cover. None of the 0.002- or 0.003-inch-copper-wire cards have indicated a break in the period covered. Telemetry temperatures were initially higher than expected although they remained well within operating limits. Sensor temperatures have remained within the expected bounds.

  15. 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.

  16. 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.

  17. 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.

  18. Calorimetric study of the energetics of pregnancy in golden hamsters.

    PubMed

    Quek, V S; Trayhurn, P

    1990-10-01

    The energetics of pregnancy have been assessed in the golden hamster, using continuous whole body indirect calorimetry to determine energy expenditure throughout gestation. Energy intake was unchanged during pregnancy, either on a daily or cumulative basis. The total energy expenditure per animal was, however, significantly higher (14%) in pregnant hamsters than in virgin control animals. The increase in total expenditure was the result of increases in daily energy expenditure over the last one-third of gestation (mean increase 21%), the period during which the energy costs associated with fetal growth are highest. The respiratory quotient (RQ) of the control hamsters was approximately 0.95, but in the pregnant group there was a progressive reduction over the second half of gestation, and by parturition the RQ had fallen to 0.80. The changes in RQ indicate that there is a switch toward the oxidation of fat, away from the oxidation of carbohydrate, in the later stages of pregnancy. Measurements of body lipid suggest that the fall in RQ in the second half of pregnancy is the result of a net utilization of maternal fat reserves; 42% of maternal body lipid was lost during pregnancy, with most of the loss occurring over the final one-third of gestation. Because energy expenditure is increased (relative to virgin controls) without any change in energy intake, it is evident that the efficiency of energy utilization (energy gain per unit of energy intake) is not increased during pregnancy in the golden hamster.

  19. Calorimetric method for the determination of Curie temperatures of magnetic nanoparticles in dispersion.

    PubMed

    Nica, V; Sauer, H M; Embs, J; Hempelmann, R

    2008-05-21

    Mn(x)Zn(1-x)Fe(2)O(4)-based magnetic fluids with x = 0.1-0.9 are synthesized by coprecipitation. The samples are heated in a radio frequency (rf) magnetic field using an rf generator at different powers, and the temperature is measured as function of time using an optical thermometer. The heating effect of the dispersed magnetic nanoparticles is proportional to the imaginary part of the dynamic magnetic susceptibility of the ferrofluid, a quantity that depends on the temperature through the magnetization of the ferrite nanoparticles and the Néel or Brownian relaxation times, respectively. We propose an extrapolation method to actuate the Curie temperatures of the dispersed magnetic nanoparticles. By means of appropriate fitting functions for (dT/dt) versus T for both the heating and the cooling process, we deduce the Curie temperature of the samples under investigation. For Mn(x)Zn(1-x)Fe(2)O(4)-based magnetic nanoparticles the Curie temperatures decrease with increasing Zn content. They turn out to be lower than the literature values for bulk Mn(x)Zn(1-x)Fe(2)O(4), a phenomenon which is generally observed for phase transitions of nanocrystalline materials.

  20. Calorimetric determination of the heat of combustion of spent Green River shale at 978 K

    SciTech Connect

    Mraw, S.C.; Keweshan, C.F.

    1987-08-01

    A Calvet-type calorimeter was used to measure heats of combustion of spent Colorado oil shales. For Green River shale, the samples were members of a sink-float series spanning oil yields from 87 to 340 L . tonne/sup -1/. Shale samples (30-200 mg) are dropped into the calorimeter at high temperature, and a peak in the thermopile signal records the total enthalpy change of the sample between room temperature and the final temperature. Duplicate samples from the above sink-float series were first retorted at 773 K and then dropped separately into nitrogen and oxygen at 978 K. The resulting heats are subtracted to give the heat of combustion, and the results are compared to values from classical bomb calorimetry. The agreement shows that the heats of combustion of the organic component are well understood but that question remain on the reactions of the mineral components.

  1. A direct calorimetric determination of denaturation enthalpy for lysozyme in sodium dodecyl sulfate.

    PubMed

    Behbehani, G Rezaei; Saboury, A A; Taleshi, E

    2008-02-15

    Thermodynamics of the interaction between sodium dodecyl sulfate (SDS) with lysozyme were investigated at pH 7.0 and 27 degrees C in phosphate buffer by isothermal titration calorimetry. A new method to follow protein denaturation, and the effect of surfactants on the stability of proteins was introduced. The new solvation model was used to reproduce the enthalpies of lysozyme-SDS interaction over the whole range of SDS concentrations. The solvation parameters recovered from the new equation, attributed to the structural change of lysozyme and its biological activity. At low concentrations of SDS, the binding is mainly electrostatic, with some simultaneous interaction of the hydrophobic tail with nearby hydrophobic patches on the lysozyme. These initial interactions presumably cause some protein unfolding and expose additional hydrophobic sites. The enthalpy of denaturation is 160.81+/-0.02 kJ mol(-1) for SDS.

  2. 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.

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

    SciTech Connect

    Cerny, S.; Smutek, M. )

    1990-05-01

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

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

    SciTech Connect

    Liu, JX; Barmak, K

    2015-07-15

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

  5. 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.

  6. 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

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed

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

    2017-02-04

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

  9. 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.

  10. 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.

  11. 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.

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

    PubMed

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

    2014-05-09

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

  14. Patterson-function direct methods for structure determination of organic compounds from powder diffraction data. XVI.

    PubMed

    Rius, Jordi

    2011-01-01

    A new type of direct methods (DM) called Patterson-function DM are presented that directly explore the Patterson instead of the modulus function. Since they work with the experimental intensities, they are particularly well suited for handling powder diffraction data. These methods are based on the maximization of the sum function S(P) ∝ ∑H(I(H)-)G(-H)(Φ) in terms of the Φ phases of the structure factors. The quantity accessible from the experiment is I(H), the equidistributed multiplet intensity of reflection H, and is the average intensity taken over all non-systematically absent reflections. G(-H)(Φ) is the calculated structure-factor amplitude of the squared structure that includes the positivity and the atomicity of the density function in its definition. The S(P) sum function can be optimized with the Patterson-function tangent formula (TF) using a variant of the S-FFT algorithm [Rius et al. (2007), Acta Cryst. A63, 131-134]. It is important that overlapped reflections also participate in the phase refinement, so that not only the resolved reflections but the whole pattern contribute decisively to the refinement. The increase in effective data resolution minimizes Fourier series termination effects and improves the accuracy of G(Φ). The Patterson-function TF has been applied to synchrotron powder data of various organic compounds. In all cases the molecules were easily identified in the respective Fourier maps. By way of illustration the method is applied to synchrotron powder data of a dimer formed by 30 symmetry-independent non-H atoms. Since single-crystal data may be regarded as overlap-free powder data, it is clear that Patterson-function DM can cope with powder and single-crystal data.

  15. 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 and Alcoholism (DAA); Correction AGENCY: Social Security Administration. ACTION: Notice of...

  16. 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

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY ADMINISTRATION Social Security Ruling 11-1p; Titles II and XVI: Procedures for Handling Requests To File Subsequent Applications for Disability Benefits AGENCY: Social Security Administration. ACTION: Notice...

  17. 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

    2016-06-07

    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.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

  2. 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.

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

    PubMed

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

    2014-12-21

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

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

    PubMed Central

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

    2016-01-01

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

  5. 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.

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

    NASA Astrophysics Data System (ADS)

    Jaworske, Donald A.

    1994-12-01

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

  7. 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.

  8. 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

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

    PubMed

    Textor, Martin; Vargas, Carolyn; Keller, Sandro

    2015-04-01

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

  10. 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...

  11. 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...

  12. 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...

  13. 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.

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

    PubMed Central

    López, Gloria

    2014-01-01

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

  15. 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

  16. 3D modeling and characterization of a calorimetric flow rate sensor for sweat rate sensing applications

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

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

  17. 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.

  18. 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.

  19. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2007-06-01

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

  1. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

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

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

    PubMed

    Basu, Anirban; Kumar, Gopinatha Suresh

    2014-01-08

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

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

    PubMed

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

    2012-05-30

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

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

    NASA Astrophysics Data System (ADS)

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

    2007-02-01

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

  6. 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.

  7. 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).

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

    PubMed

    Faller, L D; Johnson, A M

    1974-04-01

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

  9. 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).

  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.

    2015-05-01

    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).

  11. 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

  12. XVI European Charcot Foundation Lecture: Nutrition and environment, can MS be prevented?

    PubMed Central

    Simon, Kelly Claire; Munger, Kassandra L; Ascherio, Alberto

    2012-01-01

    Multiple sclerosis is a relatively common debilitating neurologic disease that affects people in early adulthood. While the characteristic pathology of MS has been well described, the etiology of the disease is not well understood, despite decades of research and the identification of strong genetic and environmental candidates for susceptibility. A question central to all diseases, but posed specifically for MS at the XVI European Charcot Foundation Lecture, was ‘Can MS be prevented?’ To address this question, we have evaluated the available data regarding nutritional and environmental factors that may be related to MS susceptibility and suggest the extent to which a potential intervention may reduce disease burden. It is our opinion that intervention, particularly supplementation with vitamin D, could have a dramatic impact on disease prevalence. Understanding that any intervention or behavioral modification will surely act in the context of genetic susceptibility and unidentified stochastic events, it is likely that not all MS is ‘preventable’. Epidemiologic observation has provided key insights into environmental and nutritional factors that may alter one’s susceptibility to MS, however, there are still many questions in unraveling the etiology of this complex disease. PMID:21975017

  13. 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

  14. 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.

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

    PubMed

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

    1985-10-08

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

  16. 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

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

    PubMed Central

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

    2014-01-01

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

  18. Religion and the Catholic church's view on (heart) transplantation: a recent statement of Pope Benedict XVI and its practical impact.

    PubMed

    Schwarz, Ernst R; Rosanio, Salvatore

    2011-09-01

    Heart transplantation is performed on approximately 4,000 patients per year worldwide and is considered the last resort for treatment of end-stage heart diseases. Due to persistent organ shortage, resources are limited, waiting periods are extensive, and patients still die while being on a waiting list for transplantation. The role of all churches and the support of the representatives of the churches are critical for the spiritual wellbeing of patients awaiting heart transplantation as well as for prospective individual organ donors and their families. The supportive role of the Roman Catholic Church and the recent statement of Pope Benedict XVI on organ donation are discussed.

  19. Enzymic determination of free and esterified cholesterol in serum by microcalorimetry.

    PubMed

    Rehak, N N; Young, D S

    1982-11-01

    Concentrations of free and esterified cholesterol in serum can be determined simultaneously by measuring, with a batch-type microcalorimeter, the heat released during the coupled cholesterol esterase/cholesterol oxidase/catalase enzymic reaction. To differentiate the two forms of cholesterol, we used kinetic calorimetry: the rate of heat output due to enzymic hydrolysis of esterified cholesterol (the rate-determining reaction) was subtracted from the measured heat, the difference being the heat released during the enzymic oxidation of free cholesterol (the fast reaction). Results obtained by the kinetic calorimetric method agreed with those obtained by separate sequential end-point calorimetric determinations of free and total cholesterol. We also compared the kinetic calorimetric method with the cholesterol method of Abell and Kendall and a continuous-flow modification of the Liebermann-Burchard method (Technicon SMAC). De-biased linear-regression analysis of the data indicates acceptable agreement between the calorimetric and the Abell-Kendall methods (y = 0.98x + 11.5). The correlation between results by calorimetric and SMAC methods shows a significant proportional error (y = 1.17x - 159.4). Bilirubin (up to 200 mg/L) does not interfere with the calorimetry.

  20. 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.

  1. 20 CFR 404.1597a - Continued benefits pending appeal of a medical cessation determination.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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...

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

    PubMed

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

    2017-03-01

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

  3. 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.

  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. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2001-08-01

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

  7. 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

  8. Mitochondrial DNA analysis on remains of a putative son of Louis XVI, King of France and Marie-Antoinette.

    PubMed

    Jehaes, E; Decorte, R; Peneau, A; Petrie, J H; Boiry, P A; Gilissen, A; Moisan, J P; Van den Berghe, H; Pascal, O; Cassiman, J J

    1998-01-01

    Carl Wilhelm Naundorff was buried in 1845 in Delft as Louis Charles, Duc de Normandie, 'Louis XVII'. However, the son of Louis XVI and Marie-Antoinette-Louis XVII--officially died in the Temple of Paris in 1795. In order to resolve the identity of Naundorff, mitochondrial DNA (mtDNA) D-loop sequences of his remains were compared with the sequences obtained from the hairs of two sisters of Marie-Antoinette, Marie-Antoinette herself, and with the sequences obtained from DNA samples of two living maternal relatives. The mtDNA sequence of a bone sample from Naundorff showed two nucleotide differences from the sequences of the three sisters and four differences from the sequences of living maternal relatives. Based on this evidence it becomes very unlikely that Naundroff is the son of Marie-Antoinette.

  9. 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.

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

    PubMed

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

    2006-07-01

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

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

    SciTech Connect

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

    1990-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

  13. 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 (

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

    PubMed

    Paul, Puja; Kumar, Gopinatha Suresh

    2014-08-01

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

  16. 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.

  17. 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.

  18. Simultaneous determination of equilibrium constants and enthalpy changes by titration calorimetry: Methods, instruments, and uncertainties.

    PubMed

    Hansen, Lee D; Fellingham, Gilbert W; Russell, Donald J

    2011-02-15

    Calorimetric methods have been used to determine equilibrium constants since 1937, but no comprehensive review of the various calorimeters and methods has been done previously. This article reports methods for quantitative comparison of the capabilities of calorimeters for simultaneous determination of equilibrium constants and enthalpy changes, for determining optimal experimental conditions, and for assessing the effects of systematic and random errors on the accuracy and precision of equilibrium constants and enthalpy changes determined by this method.

  19. Calorimetric and ionimetric dosimetry intercomparisons II: d + T neutron source at the Antoni Van Leeuwenhoek hospital.

    PubMed

    McDonald, J C; Ma, I C; Mijhnheer, B J; Zoetelief, H

    1981-01-01

    A series of dosimetric measurements was carried out at the Antoni van Leeuwenhoek Hospital, Amsterdam, using a Philips d + T generator, which produced neutrons with energies of approximately 14 MeV. A-150 plastic ionization chambers, an A-150 plastic calorimeter, and a GM dosimeter were used to determine total absorbed dose and the photon absorbed dose fraction. The ion chambers were calibrated in a 60Co gamma-ray field in air and compared in a phantom placed in the 60Co gamma-ray beam. Comparison of the total absorbed dose derived from the ionization chamber measurements to that determined using the calorimeter indicated agreement for the neutron measurements between the techniques to within +/- 2%.

  20. 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.

  1. Thermal Radiation from Hot Surfaces Measured by Optical and Calorimetric Methods.

    DTIC Science & Technology

    1982-01-01

    obtained by several means, one of which is a near-normal incidence spectral reflectance measurement . This measurement is used predominantly by the...this data. To convert a near-normal incidence spectral reflectance measurement into a total hemispherical emittance value, certain assumptions must be...total radiative loss as derived by a near-normal incidence spectral reflectance measurement and compares it to the value determined experimentally by a

  2. Calorimetric and thermodielectrical measurements of water interactions with some food materials.

    PubMed

    Ollivon, M R

    1991-01-01

    A new thermoanalytical method, which allows the measurement of complex dielectrical permittivities as a function of temperature in the microwave frequency domain, is described and compared to Differential Scanning Calorimetry (DSC) with respect to the characterization of water in food materials. Ice crystallization temperatures and melting enthalpies, measured by DSC dynamically on the same sample, allowed precise determination of the amount of frozen water and its enthalpy as a function of total water content, especially at low water contents near the unfrozen water limit. Thermal and Dielectrical Analysis (TDA) measurements provide immediate information about water interactions in food materials, even down to the lowest water contents, which are generally difficult to assess by other techniques. Dielectrical behaviour of eight glucose-water melts, containing from 0 to 24% water, has been examined as a function of temperature. The dependence of the observed dielectric relaxations on water content and temperature are discussed, and the results obtained by TDA are compared to those from conventional frequency sweeping determinations. The influence of temperature, hydration, and state of the material on dielectrical relaxation determinations are also discussed, with reference to glucose and sorbitol behaviour. The variations in dielectric constant during starch heating and dehydration are presented and analysed, with the aim of understanding the microwave drying process.

  3. 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…

  4. Development of Calorimetric Particle Spectrometer and Measurement of Specific Heat at Low Temperature.

    NASA Astrophysics Data System (ADS)

    Zhou, Jun-Wei

    1991-02-01

    A dilution refrigerator has been put into work from 30 mK to 300 K to study bolometer characteristics relevant to its potential use as a high resolution X-ray and alpha, beta, gamma particle spectrometer. Tests of the energy deposited in the detector by measuring the temperature rise following absorption of individual nuclear particles or X- or gamma-rays have been done. Essential studies were made of electromagnetic and acoustic noise. A composite-composite bolometer fabricated by the group of N. Coron (Institute of Space Astrophysics, France), with whom we collaborate, was used. This design allows the separate optimization of the absorber and thermistor, and avoids problems with absorption inhomogeneties. A FWHM resolution of 10.5 KeV for 5 to 6 MeV alpha spectra was obtained. This resolution exceeds the best obtainable with surface barrier semiconductor detectors. A broad spectrum recording simultaneously gamma-rays, beta and alpha particles from 15 KeV to 6 MeV was obtained with the same bolometer cooled below 0.1 K. Other bolometers were also tested. 6 KeV X-rays have been observed with a resolution of 472 eV. The bolometers were also used for determination of specific heat of the sapphire at low temperatures. Assuming a specific heat C = AT^3, we find in a 2.3 g sample A ~eq 1.4 times 10^{-8} J/Kcdotg from T = 0.1 K to T = 0.4 K. A discussion of the systematic errors in determining A is given. From our measurements, it was determined that a bolometer designed for a future possible neutrino mass measurement would have a resolution of 7.5 eV at 80 mK under optimal operation. Since tritium was implanted in this detector, systematic errors associated with electron spectrometer beta spectrum measurements can be, in principle, avoided.

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2008-10-01

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

  7. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

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

  9. Measurement of the Fe VIII-Fe XVI 3-3 Emission in the Extreme Ultraviolet and Comparison with CHIANTI

    NASA Astrophysics Data System (ADS)

    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 Å and are made at an electron density of about 1011 cm-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 63d 2 D 5/2-3p 53d 2 2 P 3/2 and the 3p 63d 2 D 3/2-3p 53d 2 2 P 1/2 transitions at 225.25 ± 0.12 and 226.35 ± 0.10 Å, respectively. Seven lines in Fe XI, Fe XII, and Fe XIII between 200 and 205 Å 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.

  10. Geant4 simulation of the Elekta XVI kV CBCT unit for accurate description of potential late toxicity effects of image-guided radiotherapy.

    PubMed

    Brochu, F M; Burnet, N G; Jena, R; Plaistow, R; Parker, M A; Thomas, S J

    2014-12-21

    This paper describes the modelisation of the Elekta XVI Cone Beam Computed Tomography (CBCT) machine components with Geant4 and its validation against calibration data taken for two commonly used machine setups. Preliminary dose maps of simulated CBCTs coming from this modelisation work are presented. This study is the first step of a research project, GHOST, aiming to improve the understanding of late toxicity risk in external beam radiotherapy patients by simulating dose depositions integrated from different sources (imaging, treatment beam) over the entire treatment plan. The second cancer risk will then be derived from different models relating irradiation dose and second cancer risk.

  11. Geant4 simulation of the Elekta XVI kV CBCT unit for accurate description of potential late toxicity effects of image-guided radiotherapy

    NASA Astrophysics Data System (ADS)

    Brochu, F. M.; Burnet, N. G.; Jena, R.; Plaistow, R.; Parker, M. A.; Thomas, S. J.

    2014-12-01

    This paper describes the modelisation of the Elekta XVI Cone Beam Computed Tomography (CBCT) machine components with Geant4 and its validation against calibration data taken for two commonly used machine setups. Preliminary dose maps of simulated CBCTs coming from this modelisation work are presented. This study is the first step of a research project, GHOST, aiming to improve the understanding of late toxicity risk in external beam radiotherapy patients by simulating dose depositions integrated from different sources (imaging, treatment beam) over the entire treatment plan. The second cancer risk will then be derived from different models relating irradiation dose and second cancer risk.

  12. Temperature-dependent interactions and disorder in the spin-transition compound [Fe(II)(L)2][ClO4]2.C7H8 through structural, calorimetric, magnetic, photomagnetic, and diffuse reflectance investigations.

    PubMed

    Mishra, Vibha; Mukherjee, Rabindranath; Linares, Jorge; Balde, Chérif; Desplanches, Cédric; Létard, Jean-François; Collet, Eric; Toupet, Loic; Castro, Miguel; Varret, François

    2008-09-01

    The title compound [Fe (II)(L) 2][ClO 4] 2.C 7H 8 (L = 2-[3-(2'-pyridyl)pyrazol-1-ylmethyl]pyridine) has been isolated while attempting to grow single crystals of the spin-transition (continuous-type) compound [Fe (II)(L) 2][ClO 4] 2, published earlier ( Dalton Trans. 2003, 3392-3397). Magnetic susceptibility measurements, as well as Mossbauer and calorimetric investigations on polycrystalline samples of [Fe(L) 2][ClO 4] 2.C 7H 8 revealed the occurrence of an abrupt HS ( (5) T 2) <--> LS ( (1) A 1) transition with steep and narrow (2 K) hysteresis at approximately 232 K. The photomagnetic properties exhibit features typical for a broad distribution of activation energies, with relaxation curves in the shape of stretched exponentials. We performed a crystal structure determination of the compound at 120, 240, and 270 K. A noteworthy temperature-dependent behavior of the structural parameters was observed, in terms of disorder of both the anions and solvent molecules, leading to a strong thermal dependence of the strength and dimensionality of the interaction network. Additional data were obtained by diffuse reflectance measurements. We model and discuss the antagonistic effects of interactions and disorder by using a two-level cooperative mean-field approach which includes a distribution of barrier energies at the microscopic scale.

  13. 76 FR 56263 - Titles II and XVI: Documenting and Evaluating Disability in Young Adults

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-12

    ...(s) through a school or a community agency, such as a mental health center or vocational... mental impairment(s) \\7\\ that results in ``an inability to do any substantial gainful activity.'' \\8\\ \\6... medically determinable physical or mental impairment(s) that is severe? \\10\\ If no, the person is...

  14. 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.

  15. Development of magnetic nanoparticle based calorimetric assay for the detection of bovine mastitis in cow milk.

    PubMed

    Chinnappan, Raja; Al Attas, Sana; Kaman, Wendy E; Bikker, Floris J; Zourob, Mohammed

    2017-04-15

    Mastitis in dairy cattle is an inflammatory reaction of the udder tissue. Mastitis increases plasmin levels, leading to an increased proteolysis of milk proteins such as casein, resulting in a significant decrease in milk quality and related dairy products. Due to its key-role in mastitis, we used plasmin proteolytic activity as a biomarker for the detection of mastitis in bovine mastitic milk. Inspired by earlier studies on protease activity using mastitic milk samples, we developed a simple colorimetric assay to distinguish mastitic milk from milk derived from healthy animals. The plasmin substrate coupled to magnetic nanoparticles form a black self-assembled monolayer on a gold sensor surface. In the presence of increased levels of plasmin, the substrate is cleaved and the peptide fragment attached to the magnetic beads, will be attracted by the magnet which is present under the sensor strips revealing the golden surface. We found the area of the golden color surface proportional to plasmin activity. The sensitivity of this method was determined to be 1 ng/ml of plasmin in vitro. Next, we tested the biosensor using mastitis positive milk of which infection is confirmed by bacterial cultures. This newly developed colorimetric biosensor has high potential in applications for the diagnosis of mastitis with potential spin offs to health, food and environmental sectors.

  16. Calorimetric studies of Cu-Li, Li-Sn, and Cu-Li-Sn.

    PubMed

    Fürtauer, S; Tserenjav, E; Yakymovych, A; Flandorfer, H

    2013-06-01

    Integral molar enthalpies of mixing were determined by drop calorimetry for Cu-Li-Sn at 1073 K along five sections xCu/xSn ≈ 1:1, xCu/xSn ≈ 2:3, xCu/xSn ≈ 1:4, xLi/xSn ≈ 1:1, and xLi/xSn ≈ 1:4. The integral and partial molar mixing enthalpies of Cu-Li and Li-Sn were measured at the same temperature, for Li-Sn in addition at 773 K. All binary data could be described by Redlich-Kister-polynomials. Cu-Li shows an endothermic mixing effect with a maximum in the integral molar mixing enthalpy of ∼5300 J · mol(-1) at xCu = 0.5, Li-Sn an exothermic minimum of ∼ -37,000 J · mol(-1) at xSn ∼ 0.2. For Li-Sn no significant temperature dependence between 773 K and 1073 K could be deduced. Our measured ternary data were fitted on the basis of an extended Redlich-Kister-Muggianu model for substitutional solutions. Additionally, a comparison of these results to the extrapolation model of Chou is given.

  17. Combined force spectroscopy, AFM and calorimetric studies to reveal the nanostructural organization of biomimetic membranes.

    PubMed

    Suárez-Germà, C; Morros, A; Montero, M T; Hernández-Borrell, J; Domènech, Ò

    2014-10-01

    In this work we studied a binary lipid matrix of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (POPG), a composition that mimics the inner membrane of Escherichia coli. More specifically, liposomes with varying fractions of POPG were analysed by differential scanning calorimetry (DSC) and a binary phase diagram of the system was created. Additionally, we performed atomic force microscopy (AFM) imaging of supported lipid bilayers (SLBs) of similar compositions at different temperatures, in order to create a pseudo-binary phase diagram specific to this membrane model. AFM study of SLBs is of particular interest, as it is conceived as the most adequate technique not only for studying lipid bilayer systems but also for imaging and even nanomanipulating inserted membrane proteins. The construction of the above-mentioned phase diagram enabled us to grasp better the thermodynamics of the thermal lipid transition from a gel-like POPE:POPG phase system to a more fluid phase system. Finally, AFM force spectroscopy (FS) was used to determine the nanomechanics of these two lipid phases at 27°C and at different POPG fractions. The resulting data correlated with the specific composition of each phase was calculated from the AFM phase diagram obtained. All the experiments were done in the presence of 10 mM of Ca(2+), as this ion is commonly used when performing AFM with negatively charged phospholipids.

  18. 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.

  19. 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.

  20. 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.

  1. Ground calorimetric studies using the REMS ground temperature sensor and the Curiosity rover

    NASA Astrophysics Data System (ADS)

    Zorzano, María-Paz; Martín-Torres, Francisco Javier; Newman, Claire; de la Torre, Manuel; Hamilton, Victoria; Sebastian, Eduardo; Javier Gómez-Elvira, REMS Team; the MSL Science Team

    2013-04-01

    The REMS instrument, on board the Curiosity rover, has an infrared ground temperature sensor that allows monitoring the diurnal evolution of the ground temperature every day at the different sites visited by the rover during its operation on Gale crater. The amplitude of the diurnal ground temperature oscillation depends on the local column of dust, as well as on the thermal inertia (I) of the ground. The rover has a hot Radiosotope Thermal Generator (RTG) of which the temperature is monitored by engineering sensors. This element is an unavoidable extra source of heat that irradiates the ground where the rover stands. Whenever the rover moves and samples a new site the sensed temperature shows a significant drop that ranges between 3 and 15 K depending on the location and time of the day. This drop is the increment of temperature (ΔT) caused by the heat (q) emited by the RTG source alone, and thus the soil heat capacity (C) can be obtained by rating these magnitudes and allowing the rover to perform in situ ground calorimetry in a simple way: - The heat emited by the RTG can be evaluated using the Stefan Boltzman law (q=σT4) - The soil heat capacity scales with the square of the termal inertial ( C ~ I2) Orbitally determined inertias in the region of the rover [Fergason et al., 2012 ] range from 250 (J/m2K s1/2 ) to 410 (J/m2K s1/2). Thus in the area explored by the rover I may vary a factor 2, which leads to a factor 4 increment in C and thus the final ground offset induced by the RTG extra heating is expected to be significantly greater for soils of higher thermal inertia. Once the rover stands at a fixed position the ground is heated up as the ground responses in time to the irradiated heat until a new equilibrium temperature is reached. Soils with low thermal inertia respond faster to the RTG heating source (around 40 minutes) whereas high thermal inertia soils respond more slowly (around 75 minutes). This method shall be improved for future calorimetry

  2. VizieR Online Data Catalog: PHAT. XVI. Star cluster masses and ages (Johnson+, 2016)

    NASA Astrophysics Data System (ADS)

    Johnson, L. C.; Seth, A. C.; Dalcanton, J. J.; Beerman, L. C.; Fouesneau, M.; Lewis, A. R.; Weisz, D. R.; Williams, B. F.; Bell, E. F.; Dolphin, A. E.; Larsen, S. S.; Sandstrom, K.; Skillman, E. D.

    2016-11-01

    The Panchromatic Hubble Andromeda Treasury (PHAT) survey imaged 1/3 of the disk of M31 in six passbands spanning near-ultraviolet to near-infrared wavelengths. The survey provides resolved stellar photometry of 117 million sources that we use to determine the properties of both the cluster and field populations, with completeness limits that allow the detection of individual MS stars down to ~3Mȯ. Here we provide an overview of the crowded field stellar photometry derived for PHAT; full details are found in Dalcanton+ (2012ApJS..200...18D) and Williams+ (2014, J/ApJS/215/9). (1 data file).

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

    PubMed Central

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

    1992-01-01

    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

  4. 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

  5. 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

  6. 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…

  7. 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.

  8. 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.

  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. 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

  11. Introduction: Invertebrate Neuropeptides XVI

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This publication represents an introduction to the sixteenth in a series of special issues of the Peptides journal dedicated to invertebrate neuropeptides. The issue addresses a number of aspects of invertebrate neuropeptide research including identification of novel invertebrate neuropeptide seque...

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

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

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

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

    PubMed

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

    2014-01-31

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

  14. 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.

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

    SciTech Connect

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

    2014-01-01

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

  16. 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.

  17. 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.

  18. A calorimetrically based method to convert toxic compounds into poly-3-hydroxybutyrate and to determine the efficiency and velocity of conversion.

    PubMed

    Maskow, T; Babel, W

    2001-03-01

    A fed-batch method for converting toxic substrates into poly-3-hydroxybutyrate is presented. The method involves a series of batch-growth processes, regulated by adding small amounts of carbon substrate, during the course of which the concentration of the nitrogen source decreases and controls the distribution of the substrate-carbon assimilated. The addition of carbon substrate is controlled, and the small changes that occur in the growth pattern are interpreted using high-resolution reaction calorimetry. The method was tested with Ralstonia eutropha DSM 4058 growing on phenol, and Variovorax paradoxus DSM 4065 growing on sodium benzoate. The maximum carbon conversion efficiencies (CCEs) obtained, 23% and 27% respectively, were compared with the theoretically possible values.

  19. 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.

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

    PubMed Central

    Lewis, R N; McElhaney, R N

    2000-01-01

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

  1. Label-Free Determination of the Dissociation Constant of Small Molecule-Aptamer Interaction by Isothermal Titration Calorimetry.

    PubMed

    Vogel, Marc; Suess, Beatrix

    2016-01-01

    Isothermal titration calorimetry (ITC) is a powerful label-free technique to determine the binding constant as well as thermodynamic parameters of a binding reaction and is therefore well suited for the analysis of small molecule-RNA aptamer interaction. We will introduce you to the method and present a protocol for sample preparation and the calorimetric measurement. A detailed note section will point out useful tips and pitfalls.

  2. Thermodynamic property determination in low gravity

    NASA Technical Reports Server (NTRS)

    Margrave, J. L.

    1977-01-01

    Techniques for determining heat capacities and other properties of molten metals were investigated and critically evaluated. Precisely determining heat capacities calorimetrically in space poses several problems. The weight of a drop calorimeter block along with the necessity of obtaining a large number of data points tend to make traditional approaches appear infeasible. However, for many substances exhibiting sufficiently high thermal conductivities and with known emissivities, it appears possible to investigate their properties by observing the rate of cooling of a levitated sphere which is initially at a uniform temperature above the melting point. A special advantage of the levitation method is that considerable supercooling is expected, making the study of the heat capacities of molten metals both above and below their melting points possible.

  3. 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.

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

    PubMed

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

    2013-11-01

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

  5. 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.

  6. Calorimetric and computational study of enthalpy of formation of 3,6-dibutanoic-1,2,4,5-tetroxane.

    PubMed

    Romero, J M; Ayala, D A; Jorge, N L; Gómez-Vara, M E; Castro, E A; Jubert, A H

    2005-10-15

    A thermochemical a rather simple experimental technique method, is used to determine the enthalpy of the formation of 3,6-dibutanoic-1,2,4,5-tetroxane. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6-311G basis set level. Some possible extensions of the present procedure are pointed out.

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

    SciTech Connect

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

    2015-07-01

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

  8. 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.

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

    PubMed

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

    2010-01-01

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

  10. 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.

  11. 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.

  12. Using the heat flow plate method for determining thermal conductivity of building materials

    NASA Astrophysics Data System (ADS)

    Flori, M.; Puţan, V.; Vîlceanu, L.

    2017-01-01

    The heat flow plate method is used to determine thermal conductivity of a building material sample made of Rohacell (insulating foam). Experimental technique consists in placing the sample with a reference material on top (polystyrene sample) in a calorimetric chamber and heating from underside. Considering that the heat flux which passes through the two layers is constant and knowing thermal conductivity of the reference material, the sample thermal conductivity is determined. The temperature difference between the two opposite sample’s sides is recorded only when the steady state is achieved (constant heat flux).

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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

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

    PubMed

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

    2015-07-29

    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.

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

    PubMed Central

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

    2010-01-01

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

  1. 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.

  2. 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.

  3. 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

  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. Surfactant loss control in chemical flooding: Spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Quarterly technical progress report. October 1, 1994--December 31, 1994

    SciTech Connect

    Somasundaran, P.

    1995-03-01

    The aim of this research is to elucidate the mechanisms underling adsorption and surface precipitation of flooding surfactants on reservoir minerals. The adsorption and desorption behaviors of tetradecyltrimethyl ammonium chloride (TTAC) and pentadecylethoxylated nonylphenol (NP-15) mixtures as reported earlier were rather complex and to better understand the interactions involved fluorescence spectroscopy and ultrafiltration were used during this report period to probe the microstructure of the adsorbed layer and to determine individual surfactant monomer concentration respectively. It was observed that pyrene was solubilized in mixed aggregates (hemimicelles) of a 1:1 TTAC:NP-15 mixture at the alumina-water interface over a wider concentration range than for TTAC alone. It was also observed that the adsorbed aggregate of a 1:1 TTAC:NP-15 mixture is as hydrophobic as the mixed micelle in solution. This is contrary to what was observed for the adsorption of TTAC alone: pyrene was preferentially solubilized in the TTAC micelles rather than the adsorbed aggregate. The preference of pyrene for the mixed adsorbed aggregates over individual aggregates is relevant to the application of surfactant mixtures in enhanced oil recovery and solubilization. The adsorption/desorption behavior of surfactants is directly related to the monomer concentration of the surfactant, hence it is important to monitor changes in monomer concentration during the adsorption and desorption processes. Ultrafiltration techniques were used to monitor the monomer concentration in solution and at the interface to determine the partitioning of the surfactants to the solid-liquid interface.

  6. 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).

  7. A calorimetric and spectroscopic comparison of the effects of cholesterol and its sulfur-containing analogs thiocholesterol and cholesterol sulfate on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine bilayer membranes.

    PubMed

    Benesch, Matthew G K; Lewis, Ruthven N A H; McElhaney, Ronald N

    2016-02-01

    We performed differential scanning calorimetric (DSC) and Fourier transform infrared (FTIR) spectroscopic studies of the effects of cholesterol (Chol), thiocholesterol (tChol) and cholesterol sulfate (CholS) on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine (DPPC) bilayer membranes. Our DSC results indicate that Chol and tChol incorporation produce small temperature increases in the main phase transition broad component while CholS markedly decreases it, but Chol decreases cooperativity and enthalpy more strongly than CholS and especially tChol. Hence, Chol and tChol thermally stabilize fluid DPPC bilayer sterol-rich domains while CholS markedly destabilizes them, and CholS and particularly tChol are less miscible in such domains. Our FTIR spectroscopic results indicate that Chol incorporation increases the rotational conformational order of fluid DPPC bilayers to a slightly and somewhat greater degree than tChol and CholS, respectively, consistent with our DSC findings. Also, Chol and CholS produce comparable degrees of H-bonding (hydration) of the DPPC ester carbonyls in fluid bilayers, whereas tChol increases H-bonding. At low temperatures, Chol is fully soluble in gel-state DPPC bilayers, whereas tChol and CholS are not. Thus tChol and CholS incorporation can produce considerably different effects on DPPC bilayers. In particular, the tChol thiol group markedly reduces its lateral miscibility and increases DPPC carbonyl H-bonding without significantly affecting the other characteristic effects of Chol itself, while the CholS sulfate group significantly reduces its ability to thermally stabilize and order fluid DPPC membranes. This latter result suggests that the molecular basis for the purported ability of CholS to "stabilize" various biological membranes should be re-examined.

  8. Thermotropic phase behavior of model membranes composed of phosphatidylcholines containing cis-monounsaturated acyl chain homologues of oleic acid: differential scanning calorimetric and /sup 31/P NMR spectroscopic studies

    SciTech Connect

    Lewis, R.N.A.H.; Sykes, B.D.; McElhaney, R.N.

    1988-02-09

    The thermotropic phase behavior of dioleoylphosphatidylcholine and six of its longer chain homologues was studied by differential scanning calorimetry and /sup 31/P nuclear magnetic resonance (NMR) spectroscopy. Aqueous dispersions of these compounds all exhibit a single endotherm upon heating but upon cooling exhibit at least two exotherms, both of which occur at temperatures lower than those of their heating endotherm. The single transition observed upon heating was shown by /sup 31/P NMR spectroscopy to be a net conversion from a condensed, subgel-like phase (L/sub c/ phase) to the liquid-crystalline state. Aqueous ethylene glycol dispersions of these compounds also exhibit single endotherms upon heating and cooling exotherms centered at temperatures lower than those of their corresponding heating endotherm. However, the behavior of the aqueous ethylene glycol dispersions differs with respect to their transition temperatures and enthalpies as well as the extent of undercooling observed, and there is some evidence of discontinuities in the cooling behavior of the odd- and even-numbered members of the homologous series. Like the aqueous dispersions, /sup 31/P NMR spectroscopy also shows that the calorimetric events observed in aqueous ethylene glycol involve net interconversions between an L/sub c/-like phase and the liquid-crystalline state. These results demonstrate that although the presence of a cis double bond can perturb the solid-state packing of the acyl chains, its presence does not preclude the formation of highly ordered subgel-like phases in lipid bilayers. In the particular case of these unsaturated phosphatidylcholines, the formation of the subgel phases is more kinetically favorable than is the case with their saturated n-acyl counterparts.

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

    PubMed

    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 (CH(2)THF) 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 k(cat) of the K48Q mutant was 430-fold lower than wild-type TS in activity, while the K(m) for the (R)-stereoisomer of CH(2)THF was 300 microM, about 30-fold larger than K(m) 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-dideazafolate (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 mutant, 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 CH(2)THF binding, while mutation at this residue does not affect much the binding of inhibitors that do not make contact with this group.

  10. 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

  11. Contributions to the Mosquito Fauna of Southeast Asia. XVI. Genus Aedes Meigen, Subgenus Aedimorphus Theobald in Southeast Asia (Contributions of the American Entomological Institute. Volume 9, Number 5)

    DTIC Science & Technology

    1973-01-01

    Biological data recorded in the literature are also given and the sources are cited. The nomenclature and chaetotaq used for females, female genitalia...North America. In most instances, however, comprehensive data on other biological factors which determine vector status are not available. Aedes...genitalia, and pupal and larval chae- totaxy of vexans vexans from the remainder of its distribution. In the absence of sufficient biological

  12. 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

  13. 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.

  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. The influence of cosolvents on hydrophilic and hydrophobic interactions. Calorimetric studies of parent and alkylated cyclomaltooligosaccharides in concentrated aqueous solutions of ethanol or urea.

    PubMed

    Castronuovo, Giuseppina; Niccoli, Marcella

    2008-11-03

    Heats of dilution in water and in aqueous 7 mol kg(-1) urea and 3 mol kg(-1) ethanol of binary solutions containing cyclomaltohexaose, cyclomaltoheptaose, cyclomaltooctaose, 2-hydroxypropyl-cyclomaltohexaose (HPαCD), 2-hydroxypropyl-cyclomaltoheptaose (HPβCD), methyl-cyclomaltohexaose (MeαCD), methyl-cyclomaltoheptaose (MeβCD) and 2-hydroxypropyl-cyclomaltooctaose (HPγCD) have been determined at 298.15K by flow microcalorimetry. The purpose of this study is to gain information about the influence of urea and ethanol, which have different effects on water structure, on hydrophilic and hydrophobic interactions. The pairwise interaction coefficients of the virial expansion of the excess enthalpies were evaluated and compared to those previously obtained for binary solutions of cyclomaltohexaose and cyclomaltoheptaose. The particular behaviour of cyclomaltooligosaccharides in water is put in evidence with respect to that shown by simple oligosaccharides. The values of the interaction coefficients greatly change in dependence of the solvent medium. They are negative in water for unsubstituted cyclomaltooligosaccharides, and positive for the alkyl-substituted ones, thus marking the major role of the hydrophobic interactions. In concentrated aqueous ethanol, coefficients are negative, while they are positive in concentrated aqueous urea. Urea solvates the hydroxyl group provoking the attenuation of hydrophilic and hydrophobic interactions. Instead, the presence of the cosolvent ethanol, which lowers the relative permittivity of the medium, enhances the strength of hydrophilic interactions.

  16. 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.

  17. Calorimetric study of proton tunneling in solid 5-bromo-9- hydroxyphenalenone and deuteration-induced phase transitions in its deuteroxy analog

    NASA Astrophysics Data System (ADS)

    Matsuo, Takasuke; Kohno, Kenichi; Inaba, Akira; Mochida, Tomoyuki; Izuoka, Akira; Sugawara, Tadashi

    1998-06-01

    The heat capacities of 5-bromo-9-hydroxyphenalenone (BHP) and its deuteroxy derivative (BDP) were measured at temperatures between 2 and 310 K. The heat capacity of BHP is a smooth function of temperature and that of BDP has two peaks at 21.3 and 33.9 K. By analyzing the data on BHP, a tunnel splitting of (64±2) cm-1 associated with the quantum mechanical motion of the hydrogen atom in the intramolecular O-H-O hydrogen bond was derived along with the Debye temperature 60.8 K and two Einstein temperatures 131.4 (nondegenerate) and 210.4 K (doubly degenerate). The enthalpy change of 225 J mol-1 and entropy change of 6.8 J K-1 mol-1 were determined for the total thermal effects associated with the two phase transitions in BDP. The value of the transition entropy is consistent with the twofold disorder in the high temperature phase. The tunneling energy and transition enthalpy satisfy an inequality demanded, on the assumption that the potential energies experienced by the proton and deuteron are the same, by the occurrence in BDP and nonoccurrence in BHP of the phase transitions.

  18. Surfactant loss control in chemical flooding: Spectroscopic and calorimetric study of adsorption and precipitation on reservoir minerals. Quarterly progress report, April 1, 1995--June 30, 1995

    SciTech Connect

    Somasundaran, P.

    1995-08-31

    Previously, adsorption and desorption behaviors of tetradecyl trimethyl ammonium chloride (TTAC) and pentadecylethoxylated nonyl phenol (NP-15) mixtures have been reported. It was observed that there was either synergistic or competitive adsorption between these two surfactants depending on the mixture ratios and the concentrations studied and that their adsorption/desorption behaviors were also rather complex. To better elucidate the mechanisms involved in these adsorption and desorption processes it is important to the understand the exact nature of the physico-chemical interactions between various components in mixtures and, how this in turn, controls the performance of the surfactant systems. Recently we have adapted the ultrafiltration technique to determine monomer concentrations in surfactant mixtures and to study the aggregation phenomenon between TTAC and NP-15. During the current report period, monomer concentrations of TTAC and NP-15 were measured for different mixing ratios at a constant ionic strength of 0.03 M NaCl and after adsorption for 4:1 TTAC:NP-15 mixture system. Possible behaviors of mixed micellization processes in solution are proposed and the relationship between monomer concentration and adsorption density is discussed.

  19. 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.

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

    SciTech Connect

    Somasundaran, P.

    1994-02-22

    The aim of this contract is to elucidate the mechanisms underlying adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effect of surfactant structure, surfactant combinations and other inorganic and polymeric species and solids of relevant mineralogy will also be determined. 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/desorption of tetradecyl trimethyl ammonium chloride (TTAC) and sodium dodecyl sulfate (SDS)/octaethylene glycol mono n-decyl ether (C{sub 12}EO{sub 8}) surfactant mixtures at the kaolinite-water and alumina-water interfaces was studied during this quarter. The microstructure of the adsorbed layer was investigated using spectroscopic techniques. Effect of the hydrocarbon chain length of octaethylene glycol mono n-alkyl ether (C{sub n}EO{sub 8}) type nonionic surfactants on the adsorption of 1:1 mixtures of sodium dodecyl sulfate (SDS)/C{sub n}EO{sub 8} at the kaolinite/water interface was studied. The adsorption of SDS was enhanced by the presence of C{sub 10}EO{sub 8} but this effect was not as significant as those by C{sub 12--16}EO{sub 8}. Interestingly, once the hydrocarbon chain length of the nonionic surfactant exceeded that of the SDS (12) there was no further enhancement of SDS adsorption.

  1. Thermodynamic studies on Cs 4U 5O 17(s) and Cs 2U 2O 7(s) by emf and calorimetric measurements

    NASA Astrophysics Data System (ADS)

    Jayanthi, K.; Iyer, V. S.; Venugopal, V.

    1997-12-01

    The oxygen potentials over the phase field: Cs 4U 5O 17(s)+Cs 2U 2O 7(s)+Cs 2U 4O 12(s) was determined by measuring the emf values between 1048 and 1206 K using a solid oxide electrolyte galvanic cell. The oxygen potential existing over the phase field for a given temperature can be represented by: Δ μ(O 2) (kJ/mol) (±0.5)=-272.0+0.207 T (K). The differential thermal analysis showed that Cs 4U 5O 17(s) is stable in air up to 1273 K. The molar Gibbs energy formation of Cs 4U 5O 17(s) was calculated from the above oxygen potentials and can be given by, Δ fG0 (kJ/mol)±6=-7729+1.681 T (K). The enthalpy measurements on Cs 4U 5O 17(s) and Cs 2U 2O 7(s) were carried out from 368.3 to 905 K and 430 to 852 K respectively, using a high temperature Calvet calorimeter. The enthalpy increments, ( H0T- H0298), in J/mol for Cs 4U 5O 17(s) and Cs 2U 2O 7(s) can be represented by, H0T- H0298.15 (Cs 4U 5O 17) kJ/mol±0.9=-188.221+0.518 T (K)+0.433×10 -3T2 (K)-2.052×10 -5T3 (K) (368 to 905 K) and H0T- H0298.15 (Cs 2U 2O 7) kJ/mol±0.5=-164.210+0.390 T (K)+0.104×10 -4T2 (K)+0.140×10 5(1/ T (K)) (411 to 860 K). The thermal properties of Cs 4U 5O 17(s) and Cs 2U 2O 7(s) were derived from the experimental values. The enthalpy of formation of (Cs 4U 5O 17, s) at 298.15 K was calculated by the second law method and is: Δ fH0298.15=-7645.0±4.2 kJ/mol.

  2. 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.

  3. The work of walking: a calorimetric study.

    PubMed

    Webb, P; Saris, W H; Schoffelen, P F; Van Ingen Schenau, G J; Ten Hoor, F

    1988-08-01

    Experiments were designed to test the traditional assumption that during level walking all of the energy from oxidation of fuel appears as heat and no work is done. Work is force expressed through distance, or energy transferred from a man to the environment, but not as heat. While wearing a suit calorimeter in a respiration chamber, five women and five men walked for 70 to 90 min on a level treadmill at 2.5, 4.6, and 6.7 km.h-1 and pedalled a cycle ergometer for 70 to 90 min against 53 and 92 W loads. They also walked with a weighted backpack and against a horizontal load. During cycling, energy from fuel matched heat loss plus the power measured by the ergometer. During walking, however, energy from fuel exceeded that which appeared as heat, meaning that work was done. The power increased with walking speed; values were 14, 29, and 63 W, which represented 11, 12, and 13% of the incremental cost of fuel above the resting level. Vertical and horizontal loads increased the fuel cost and heat loss of walking but did not alter the power output. This work energy did not re-appear as thermal energy during 18 h of recovery. The most likely explanation of the work done is in the inter-action between the foot and the ground, such as compressing the heel of the shoe and bending the sole. We conclude that work is done in level walking.

  4. Martensitic transformation B2-R in Ni-Ti-Fe: experimental determination of the Landau potential and quantum saturation of the order parameter.

    PubMed

    Salje, Ekhard K H; Zhang, Huali; Planes, Antoni; Moya, Xavier

    2008-07-09

    The Landau potential of the martensitic phase transformation in Ni(46.8)Ti(50)Fe(3.2) was determined using high resolution x-ray diffraction to measure the spontaneous strain and calorimetric measurements to determine the excess specific heat of the R phase. The spontaneous strain is proportional to the square of the order parameter which is tested by the relation of the excess entropy and the order parameter. The parameters of the Landau free energy were determined by fitting the temperature evolution of the order parameter and using the scaling between the excess entropy and the order parameter. The double well potential at absolute zero temperature was calculated and the interface energy and domain wall thickness were estimated.

  5. 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.

  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.

  7. Inhibition of beta-amylase activity by calcium, magnesium and zinc ions determined by spectrophotometry and isothermal titration calorimetry.

    PubMed

    Dahot, M Umar; Saboury, A A; Moosavi-Movahedi, A A

    2004-04-01

    The inhibition effect of metal ions on beta amylase activity was studied. The inhibitor-binding constant (Ki) was determined by spectrophotometric and isothermal titration calorimetric (ITC) methods. The binding of calcium, magnesium and zinc ion as inhibitors at the active site of barley beta amylase was studied at pH = 4.8 (sodium acetate 16 mM) and T = 300K. The Ki and enthalpy of binding for calcium (13.4, 13.1 mM and -14.3 kJ/mol), magnesium (18.6, 17.8mM and -17.7 kJ/mol) and zinc (17.5, 17.7 mM and -20.0 kJ/mol) were found by spectrophotometric and ITC methods respectively.

  8. 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

  9. 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....

  10. 75 FR 62676 - Disability Determinations by State Agency Disability Examiners

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-13

    ... From the Federal Register Online via the Government Publishing Office SOCIAL SECURITY... Examiners AGENCY: Social Security Administration. ACTION: Final rules. SUMMARY: We are revising our rules on... in certain claims for disability benefits under titles II and XVI of the Social Security Act...

  11. A microcalorimetric sensor for food and cosmetic analyses: l-Malic acid determination.

    PubMed

    Antonelli, Marta Letizia; Spadaro, Claudio; Tornelli, Rosalia Fortunata

    2008-02-15

    Enzymatic microcalorimetry has been successfully employed in the reliable determination of the l-malic acid concentration in some foods and cosmetic products. The l-malic acid concentration during the wine-making process is particularly useful in order to control the progress of the malo-lactic fermentation. Total acidity, taste and flavour characteristics of wine depend on the l-malic acid quantity still present. To point out the analytical methodology the dehydration process of l-malic acid, in the presence of Fumarase enzyme, has been used. The new method has been compared with a common spectrophotometric one. By the proposed calorimetric method the l-malic acid concentration in different types of food (white and red wines, fruits and soft beverages) has been determined. In some cosmetic products too the l-malic acid was quantified. The method outlined resulted simple, direct and reliable (good accuracy and precision), in particular it does not require any pre-treatment or clean up of the samples, save the dilution in buffer.

  12. 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.

  13. Calorimetric investigation of proton linkage by monitoring both the enthalpy and association constant of binding: application to the interaction of the Src SH2 domain with a high-affinity tyrosyl phosphopeptide.

    PubMed

    Bradshaw, J M; Waksman, G

    1998-11-03

    The binding of Src homology 2 (SH2) domains to tyrosyl phosphopeptides depends on electrostatic interactions between the phosphotyrosine and its binding site. To probe the role of these interactions, we have used isothermal titration calorimetry to study the pH dependence of the binding of the SH2 domain of the Src kinase to a high-affinity tyrosyl phosphopeptide. Two independent approaches were employed. In a first series of experiments that focused on determining the peptide's association constant between pH 5.0 and 9.0, two ionizable groups were characterized. One group, with free and bound pKas of 6.2 and 4.4, respectively, could be identified as the phosphate in the phosphotyrosine while the other group, with free and bound pKas of 8.2 and 8.5, respectively, could be only tentatively assigned to a cysteine in the phosphotyrosine binding pocket. Further information on the linkage between peptide binding and protonation of the phosphotyrosine was obtained from a second series of experiments, which focused on determining the peptide binding enthalpy at low values of pH in several buffers with different ionization enthalpies. These data provided free and bound pKa values for the phosphotyrosine identical to those derived from the first series of experiments, and hence demonstrated for the first time that the two approaches provide identical information regarding proton linkage. In addition, the second series of experiments also determined the intrinsic enthalpy of binding of both the protonated and deprotonated phosphate forms of the peptide. These two sets of experiments provided a complete energetic profile of the linkage between phosphate ionization and peptide binding. From this profile, it was determined that the PO32- form of the peptide binds 2.3 kcal mol-1 more favorably than the PO3H1- form due entirely to a more favorable entropy of binding.

  14. 45 CFR 206.10 - Application, determination of eligibility and furnishing of assistance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... respect the rights of individuals under the United States Constitution, the Social Security Act, title VI...) State plan requirements. A State plan under title I, IV-A, X, XIV, or XVI(AABD), of that Social Security... whichever of the State plan plans he chooses; (ii) The agency shall require a written application,...

  15. 77 FR 65754 - Cost-of-Living Increase and Other Determinations for 2013

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-30

    ... Exclusion A blind or disabled child who is a student regularly attending school, college, university, or a....50 for 2013; (3) The student earned income exclusion under title XVI of the Act will be $1,730 per...) title VIII; (4) the student earned income exclusion; (5) the fee for services performed by...

  16. DIPPER project 871 determination of ideal-gas enthalpies of formation for key compounds, The 1991 project results

    SciTech Connect

    Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.; Tasker, I.R.

    1993-09-01

    Results of a study aimed at improving group-contribution methodology for estimating thermodynamic properties of organic 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 condensed phase, vapor-pressure measurements, and differential scanning calorimetric (d.s.c.) heat-capacity measurements. Ideal-gas enthalpies of formation of cyclohexene, phthalan (2,5-dihydrobenzo-3,4-furan), isoxazole, n-octylamine, di-n-octylamine, tri-n-octylamine, phenyl isocyanate, and 1,4,5,6-tetrahydropyrimidine are reported. Two-phase (liquid + vapor) heat capacities were determined for phthalan, isoxazole, the three octylamines, and phenyl isocyanate. Liquid-phase densities along the saturation line were measured for phthalan and isoxazole at 298 to 425 K. The critical temperature and critical density of n-octylamine were determined from d.s.c. results and critical pressure derived from the fitting procedures. Fitting procedures were used to derive critical temperatures, pressures, and densities for cyclohexene (pressure and density only), phthalan, isoxazole, di-n-octylamine, and phenyl isocyanate. Group-additivity parameters or ring-correction terms are derived.

  17. 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.

  18. 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

  19. 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, (2)H NMR, and calorimetric study.

    PubMed

    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 (2)H 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 (N(TB)), 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 N(TB)-N phase transition, which is found to be weakly first order, but close to tricritical. Additionally broadband dielectric spectroscopy and (2)H 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 N(TB) 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. (2)H 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.

  20. 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.

  1. Optimized structure and thermochemical properties of flavonoids determined by the CHIH(medium) DFT model chemistry versus experimental techniques

    NASA Astrophysics Data System (ADS)

    Mendoza-Wilson, Ana María.; Lardizabal-Gutiérrez, Daniel; Torres-Moye, Enrique; Fuentes-Cobas, Luis; Balandrán-Quintana, René R.; Camacho-Dávila, Alejandro; Quintero-Ramos, Armando; Glossman-Mitnik, Daniel

    2007-12-01

    The purpose of this work was to evaluate the accuracy of the CHIH(medium)-DFT model chemistry (PBEg/CBSB2 ∗∗//PBEg/CBSB4) in the determination of the optimized structure and thermochemical properties of heterocyclic systems of medium size such as flavonoids, wherefore were selected three of the most abundant flavonoids in vegetable tissues, and which posses the higher antioxidant activity: quercetin, (+)-catechin and cyanidin. As reference systems were employed three cyclic compounds: phenol, catechol and resorcinol. The thermochemical properties evaluated were enthalpy of formation, bond dissociation enthalpy (BDE) and ionization potential (IP), following the scheme of isodesmic reactions. The theoretical results were compared with experimental data generated by X-ray diffraction and calorimetric techniques realized in part by us, whereas other data were taken from the literature. The results obtained in this work reveal that the CHIH(medium)-DFT model chemistry represents an accurate computational tool to calculate structural and thermochemical properties in the studied flavonoid and reference compounds. The average absolute deviation of enthalpy of formation for reference compounds was 3.0 kcal/mol, 2.64 kcal/mol for BDE, and 2.97 kcal/mol for IP.

  2. 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.

  3. Application of In-Line Mid-Infrared (MIR) Spectroscopy Coupled with Calorimetry for the Determination of the Molar Enthalpy of Reaction between Ammonium Chloride and Sodium Nitrite.

    PubMed

    Kartnaller, Vinicius; Mariano, Danielly C O; Cajaiba, João

    2016-03-01

    The reaction between ammonium chloride and sodium nitrite has been known for its application as a source of heat because of its large enthalpy of reaction, for which it has been used by the oil industry. There have been no known calorimetric studies for the experimental determination of its molar enthalpy of reaction, which is necessary in order to predict the limits achieved for up-scale applications. Attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) and reaction calorimetry were used to determine this value by using a simple methodology. Both techniques were used concomitantly as a source of information regarding the time-dependent moles converted (Δn) and the amount of exchanged heat (ΔH). The molar enthalpy of reaction was calculated to be -74 ± 4 kcal mol(-1). The percentage between the confidence interval and the calculated value was 5.4%, which shows that the methodology was precise. After the determination of the molar enthalpy of reaction, it was proved that the ATR FT-IR alone was able to be used as a substitute for the reaction calorimetry technique, in which the IR signal is converted to the heat information, presenting as an easier technique for the monitoring of the heat released by this system for future applications.

  4. Direct determination of k Q for Farmer-type ionization chambers in a clinical scanned carbon ion beam using water calorimetry.

    PubMed

    Osinga-Blättermann, J-M; Brons, S; Greilich, S; Jäkel, O; Krauss, A

    2017-03-21

    Until now, the dosimetry of carbon ions with ionization chambers has not reached the same level of accuracy as that of high-energy photons. This is mainly caused by the approximately threefold larger uncertainty of the k Q factor of ionization chambers, which, due to the lack of experimental data, is still derived by calculations. Measurements of absorbed dose to water, D w, by means of water calorimetry have now been performed in the entrance channel of a scanned 6 cm  ×  6 cm radiation field of 429 MeV/u carbon ions, allowing the direct calibration of ionization chambers and thus the experimental determination of k Q. Within this work, values for k Q have been determined for the Farmer-type ionization chambers FC65-G and TM30013. A detailed investigation of the radiation field enabled the accurate determination of correction factors needed for both calorimetric and ionometric measurements. Finally, a relative standard measurement uncertainty of 0.8% (k  =  1) could be achieved for the experimental k Q values. For both chambers, the experimental k Q factors were found to be about 1% larger than those tabulated in the German DIN 6801-1 protocol, whereas compared to the theoretical values stated in the TRS-398 protocol, the experimental k Q value agrees within 0.4% for the TM30013 chamber but is about 1% lower in the case of the FC65-G chamber.

  5. Direct determination of k Q for Farmer-type ionization chambers in a clinical scanned carbon ion beam using water calorimetry

    NASA Astrophysics Data System (ADS)

    Osinga-Blättermann, J.-M.; Brons, S.; Greilich, S.; Jäkel, O.; Krauss, A.

    2017-03-01

    Until now, the dosimetry of carbon ions with ionization chambers has not reached the same level of accuracy as that of high-energy photons. This is mainly caused by the approximately threefold larger uncertainty of the k Q factor of ionization chambers, which, due to the lack of experimental data, is still derived by calculations. Measurements of absorbed dose to water, D w, by means of water calorimetry have now been performed in the entrance channel of a scanned 6 cm  ×  6 cm radiation field of 429 MeV/u carbon ions, allowing the direct calibration of ionization chambers and thus the experimental determination of k Q. Within this work, values for k Q have been determined for the Farmer-type ionization chambers FC65-G and TM30013. A detailed investigation of the radiation field enabled the accurate determination of correction factors needed for both calorimetric and ionometric measurements. Finally, a relative standard measurement uncertainty of 0.8% (k  =  1) could be achieved for the experimental k Q values. For both chambers, the experimental k Q factors were found to be about 1% larger than those tabulated in the German DIN 6801-1 protocol, whereas compared to the theoretical values stated in the TRS-398 protocol, the experimental k Q value agrees within 0.4% for the TM30013 chamber but is about 1% lower in the case of the FC65-G chamber.

  6. Genomics of sex determination.

    PubMed

    Zhang, Jisen; Boualem, Adnane; Bendahmane, Abdelhafid; Ming, Ray

    2014-04-01

    Sex determination is a major switch in the evolutionary history of angiosperm, resulting 11% monoecious and dioecious species. The genomic sequences of papaya sex chromosomes unveiled the molecular basis of recombination suppression in the sex determination region, and candidate genes for sex determination. Identification and analyses of sex determination genes in cucurbits and maize demonstrated conservation of sex determination mechanism in one lineage and divergence between the two systems. Epigenetic control and hormonal influence of sex determination were elucidated in both plants and animals. Intensive investigation of potential sex determination genes in model species will improve our understanding of sex determination gene network. Such network will in turn accelerate the identification of sex determination genes in dioecious species with sex chromosomes, which are burdensome due to no recombination in sex determining regions. The sex determination genes in dioecious species are crucial for understanding the origin of dioecy and sex chromosomes, particularly in their early stage of evolution.

  7. Calorimetric study of surface and interfacial properties of fine coal

    SciTech Connect

    Melkus, T.G.A.

    1986-01-01

    In order to study the surface/interfacial properties of fine coal, heat flux calorimeter was used to make heat of immersion (..delta..H/sub imm/) measurements. These heats have been shown to be a valuable means of investigating the chemistry and surface properties of solids as they interact with adsorbate molecules. In addition, heats of immersion can be used to characterize a solid in terms of hydrophobicity/hydrophilicity and estimate its relative wetting tendency. The first phase of experiments that were performed served as a basis for comparison of coal components/characteristics immersed in deionized, distilled water. The results of these experiments were found to correlate well with reported flotation trends. In the second phase of experiments, the solids that were previously investigated were immersed in various wetting media. The solids were characterized in terms of hydrophobicity/hydrophilicity and their relative wetting tendency was also established. Heat of immersion measurements using surfactant solutions demonstrated that preferential adsorption of the surfactant molecule occurs on the coal surface, thereby altering its surface properties. This was supported by laboratory vacuum filtration tests. Using flotation agents as the wetting medium, the heat of immersion was found to vary with kerosene concentration, pH, kaolin addition and oxidation of the solid surface. The results of these ..delta..H/sub imm/ measurements were found to correlate very well with results obtained by independent flotation experiments performed under the same conditions.

  8. Isothermal calorimetric analysis of lectin-sugar interaction.

    PubMed

    Takeda, Yoichi; Matsuo, Ichiro

    2014-01-01

    Isothermal titration calorimetry (ITC) is a powerful tool for analyzing lectin-glycan interactions because it can measure the binding affinity and thermodynamic properties such as ∆H and ΔS in a single experiment without any chemical modification or immobilization. Here we describe a method for preparing glycan and lectin solution to minimize the buffer mismatch, setting parameters, and performing experiments.

  9. 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.

  10. Thermodynamic properties for polycyclic systems by non-calorimetric methods

    SciTech Connect

    Steele, W.V.; Chirico, R.D.; Klots, T.D.

    1993-03-01

    A detailed vibrational spectroscopic study of furan, pyrrole, and thiophene has been completed. These compounds form part of the base of five-membered ring systems on which the rest of the research program will be built Several methyl-substituted derivatives were also studied. The results will be used to confirm the model for alkyl- substitution in the ring systems. Gas-phase spectra and fundamental- frequency assignments were completed for 2,3- and 2,5-dihydrofuran. Those compounds initiate work on ring-puckering within the research program. A paper describing the need for third virial estimation, when using the virial equation of state to derive thermodynamic properties at pressures greater than 1 bar was completed.

  11. Calorimetric Measurements of Laser Energy and Power - 1977 Supplement

    DTIC Science & Technology

    1977-10-10

    188. M. Nakatsuka and U. Kobo , Japan. J. Appl. Phys. 15_, 1585 (1976). 189. A. V. Kubarev, A. S. Obukhov, I. N. Govor, and V. M. Nesterenko...of Sensitivity Calibration for Far- Infrared Detectors, Naval Research Lab. Interim Rept. (1976). J. Current Laser Abs . 13, 287 (1976). 207. D...Optical Evaluation of Carbon Dioxide Laser Window Materials at Air Force Cambridge Research Labs, USNTIS, AD Rept. 749864 (1972). Chem. Abs . 78

  12. Miscibility properties of binary phosphatidylcholine mixtures. A calorimetric study.

    PubMed

    van Dijck, P W; Kaper, A J; Oonk, H A; de Gier, J

    1977-10-03

    From data obtained by differential scanning calorimetry phase diagrams were constructed, using a thermodynamically based fitting method. The following binary mixtures of phosphatidylcholines in water were studied: 14:0/14:0-glycerophosphocholine/16:0/16:0-glucerophosphocholine, 14:0/14:0-glycerophosphocholine/18:0/18:0-glycerophosphocholine, 12:0/12:0-glycerophosphocholine/16:0/16:0-glycerophosphocholine, 18:1t/18:1t-glycerophosphocholine/14:0/14:0-glycerophosphocholine and 18:1t/18:1t-glycerophosphocholine/16:0/16:0-glycerophosphocholine. A comparison is made of the present results with those obtained using probe techniques and the differences are discussed.

  13. A calorimetric search on double beta decay of 130Te

    NASA Astrophysics Data System (ADS)

    Arnaboldi, C.; Brofferio, C.; Bucci, C.; Capelli, S.; Cremonesi, O.; Fiorini, E.; Giuliani, A.; Nucciotti, A.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Pobes, C.; Previtali, E.; Sisti, M.; Vanzini, M.

    2003-04-01

    We report on the final results of a series of experiments on double beta decay of 130Te carried out with an array of twenty cryogenic detectors. The set-up is made with crystals of TeO2 with a total mass of 6.8 kg, the largest operating one for a cryogenic experiment. Four crystals are made with isotopically enriched materials: two in 128Te and two others in 130Te. The remaining ones are made with natural tellurium, which contains 31.7% and 33.8% 128Te and 130Te, respectively. The array was run under a heavy shield in the Gran Sasso Underground Laboratory at a depth of about 3500 m.w.e. By recording the pulses of each detector in anticoincidence with the others a lower limit of 2.1×1023 years has been obtained at the 90% C.L. on the lifetime for neutrinoless double beta decay of 130Te. In terms of effective neutrino mass this leads to the most restrictive limit in direct experiments, after those obtained with Ge diodes. Limits on other lepton violating decays of 130Te and on the neutrinoless double beta decay of 128Te to the ground state of 128Xe are also reported and discussed. An indication is presented for the two neutrino double beta decay of 130Te. Some consequences of the present results in the interpretation of geochemical experiments are discussed.

  14. 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.

  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. Bulk and surface calorimetric measurements at CO wavelengths.

    PubMed

    Allen, S D; Rudisill, J E

    1977-11-01

    Laser calorimetry was used to measure the optical absorption of several candidate window materials for application at CO laser wavelengths. These materials include KCl, CaF(2), SrF(2), and ZnSe. The long, thin bar technique was used to separate bulk and surface absorption contributions by means of their time dependencies. One sample of KCl, known to be low absorbing at 10.6 microm, exhibited no measurable absorption within the sensitivity of the calorimeter (beta(t) < 2 x 10(-6) cm(-1)). The absorption coefficients measured for two samples of CaF(2) at 5.41 microm were higher than those measured by other investigators at 5.25 microm, but, when fitted to an exponential dependence on wavelength, compared favorably with currently measured values. To compare results from different laboratories, precise definition of the spectral power distribution is essential. The surface absorption was, in all cases, small relative to similar measurements at 10.6 microm; in several cases it was not separable from bulk absorption by the technique used.

  17. Calorimetric studies of the thermal denaturation of cytochrome c peroxidase

    SciTech Connect

    Kresheck, G.C.; Erman, J.E.

    1988-04-05

    Two endotherms are observed by differential scanning calorimetry during the thermal denaturation of cytochrome c peroxidase at pH 7.0. The transition midpoint temperatures (t/sub m/) were 43.9 +- 1.4 and 63.3 +- 1.6 /sup 0/C, independent of concentration. The two endotherms were observed at all pH values between 4 and 8, with the transition temperatures varying with pH. Precipitation was observed between pH 4 and 6, and only qualitative data are presented for this region. The thermal unfolding of cytochrome c peroxidase was sensitive to the presence and ligation state of the heme. Only a single endotherm was observed for the unfolding of the apoprotein, and this transition was similar to the high-temperature transition in the holoenzyme. Addition of KCN to the holoenzyme increases the midpoint of the high-temperature transition whereas the low-temperature transition was increased upon addition of KF. Binding of the natural substrate ferricytochrome c to the enzyme increases the low-temperature transition by 4.8 +- 1.3 /sup 0/C but has no effect on the high-temperature transition at pH 7. The presence of cytochrome c peroxidase decreases the stability of cytochrome c, and both proteins appear to unfold simultaneously. The results are discussed in terms of the two domains evident in the X-ray crystallographic structure of cytochrome c peroxidase

  18. Calorimetric Measurements at Low Temperatures in Toluene Glass and Crystal

    NASA Astrophysics Data System (ADS)

    Alvarez-Ney, C.; Labarga, J.; Moratalla, M.; Castilla, J. M.; Ramos, M. A.

    2017-04-01

    The specific heat of toluene in glass and crystal states has been measured both at low temperatures down to 1.8 K (using the thermal relaxation method) and in a wide temperature range up to the liquid state (using a quasiadiabatic continuous method). Our measurements therefore extend earlier published data to much lower temperatures, thereby allowing to explore the low-temperature "glassy anomalies" in the case of toluene. Surprisingly, no indication of the existence of tunneling states is found, at least within the temperature range studied. At moderate temperatures, our data either for the glass or for the crystal show good agreement with those found in the literature. Also, we have been able to prepare bulk samples of toluene glass by only doping with 2% mol ethanol instead of with higher impurity doses used by other authors.

  19. 20 CFR 641.510 - What types of income are included and excluded for participant eligibility determinations?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... under title XVI of the Social Security Act (42 U.S.C. 1381 et seq.), a payment made to or on behalf of... Affairs, or 25 percent of a benefit received under title II of the Social Security Act (42 U.S.C. 401...

  20. Core lipid structure is a major determinant of the oxidative resistance of low density lipoprotein.

    PubMed Central

    Schuster, B; Prassl, R; Nigon, F; Chapman, M J; Laggner, P

    1995-01-01

    The influence of thermally induced changes in the lipid core structure on the oxidative resistance of discrete, homogeneous low density lipoprotein (LDL) subspecies (d, 1.0297-1.0327 and 1.0327-1.0358 g/ml) has been evaluated. The thermotropic transition of the LDL lipid core at temperatures between 15 degrees C and 37 degrees C, determined by differential scanning calorimetry, exerted significant effects on the kinetics of copper-mediated LDL oxidation expressed in terms of intrinsic antioxidant efficiency (lag time) and diene production rate. Thus, the temperature coefficients of oxidative resistance and maximum oxidation rate showed break points at the core transition temperature. Temperature-induced changes in copper binding were excluded as the molecular basis of such effects, as the saturation of LDL with copper was identical below and above the core transition. At temperatures below the transition, the elevation in lag time indicated a greater resistance to oxidation, reflecting a higher degree of antioxidant protection. This effect can be explained by higher motional constraints and local antioxidant concentrations, the latter resulting from the freezing out of antioxidants from crystalline domains of cholesteryl esters and triglycerides. Below the transition temperature, the conjugated diene production rate was decreased, a finding that correlated positively with the average size of the cooperative units of neutral lipids estimated from the calorimetric transition width. The reduced accessibility and structural hindrance in the cluster organization of the core lipids therefore inhibits peroxidation. Our findings provide evidence for a distinct effect of the dynamic state of the core lipids on the oxidative susceptibility of LDL and are therefore relevant to the atherogenicity of these cholesterol-rich particles. PMID:7708675

  1. Self-Determination.

    ERIC Educational Resources Information Center

    Transition Summary, 1988

    1988-01-01

    This issue of "Transition Summary" contains articles about self-determination and becoming a good self-advocate, with each article reflecting the experience of someone who has grown up with a disability. "The Many Facets of Self-Determination" (Michael Ward) discusses the concept of self-determination; offers an historical perspective of the…

  2. 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…

  3. [Comparison of resting energy expenditure determined by indirect calorimetry and estimated by predictive formulas in women with obesity degrees I to III].

    PubMed

    Parra-Carriedo, Alicia; Cherem-Cherem, Loren; Galindo-De Noriega, Daniela; Díaz-Gutiérrez, Mary Carmen; Pérez-Lizaur, Ana Bertha; Hernández-Guerrero, César

    2013-01-01

    Introducción: La determinación del gasto energético en reposo (GER) se calcula cotidianamente a partir de fórmulas predictivas aunque el resultado varía dependiendo de la población. Objetivo: Comparar la determinación del GER mediante calorimetría indirecta y mediante las ecuaciones Harris-Benedict (HB), Mifflin (MF), Organización Mundial de la Salud (OMS), «Institute of Medicine» (IOM), Fórmula Rápida (FR) y Valencia (VA) en mujeres con grados de obesidad I a III. Métodos: Mujeres adultas mestizas mexicanas se incluyeron en el estudio y formaron 3 grupos a partir del índice de masa corporal (IMC). Obesidad grado I (IMC 30,0-34,9; n = 42), grado II (IMC 35,0-39,9; n = 38) y grado III (IMC > 40; n = 41). Se determinó el GER mediante calorimetría indirecta y mediante las ecuaciones antes señaladas. ANOVA de Kruskal-Wallis y la prueba de Dunn se emplearon para el análisis estadístico (p < 0,05 se aceptó como diferencia). Resultados: No se observó diferencia estadística entre los valores de las fórmulas HB, OMS y VA respecto a la CI. La concordancia obtenida de dichas fórmulas fue 63%, 67% y 64%, respectivamente, al analizar los datos en un solo grupo de obesidad. Asimismo, las fórmulas IOM, ER y MF mostraron diferencia estadística significativa versus la CI, siendo la concordancia 58%, 53% y 54%, respectivamente. En el grado III de obesidad la concordancia de VA (78%) y FR (71%) fue la mayor obtenida. Discusión: Las fórmulas HB, OMS y VA fueron las mejores para estimar el GER en mujeres mexicanas con IMC>30. En el grado III VA y FR muestran el mejor desempeño.

  4. The Herschel Virgo Cluster Survey - XVI. A cluster inventory

    NASA Astrophysics Data System (ADS)

    Davies, J. I.; Bianchi, S.; Baes, M.; Bendo, G. J.; Clemens, M.; De Looze, I.; di Serego Alighieri, S.; Fritz, J.; Fuller, C.; Pappalardo, C.; Hughes, T. M.; Madden, S.; Smith, M. W. L.; Verstappen, J.; Vlahakis, C.

    2014-03-01

    Herschel far-infrared (FIR) observations are used to construct Virgo cluster galaxy luminosity functions and to show that the cluster lacks the very bright and the numerous faint sources detected in field galaxy surveys. The FIR spectral energy distributions are fitted to obtain dust masses and temperatures and the dust mass function. The cluster is overdense in dust by about a factor of 100 compared to the field. The same emissivity (β)-temperature relation applies for different galaxies as that found for different regions of M31. We use optical and H I data to show that Virgo is overdense in stars and atomic gas by about a factor of 100 and 20, respectively. Metallicity values are used to measure the mass of metals in the gas phase. The mean metallicity is ˜0.7 solar, and ˜50 per cent of the metals are in the dust. For the cluster as a whole, the mass density of stars in galaxies is eight times that of the gas and the gas mass density is 130 times that of the metals. We use our data to consider the chemical evolution of the individual galaxies, inferring that the measured variations in the effective yield are due to galaxies having different ages, being affected to varying degrees by gas loss. Four galaxy scaling relations are considered: mass-metallicity, mass-velocity, mass-star formation rate and mass-radius - we suggest that initial galaxy mass is the prime driver of a galaxy's ultimate destiny. Finally, we use X-ray observations and galaxy dynamics to assess the dark and baryonic matter content compared to the cosmological model.

  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. Electron Acceptor-Electron Donor Interactions. XV and XVI.

    DTIC Science & Technology

    mixtures exhibit simple eutectic phase diagrams and the thermochromic effect is interpreted as a randomized structure in the liquid , whereas the solid is a...two-phase aggregate of isolated acceptor and onor crystals . The charge-transfer spectra of solutions of tungsten and molybdenum hexafluorides and iodine heptafluoride in n-hexane and cyclohexane were obtained.

  7. Planck 2015 results. XVI. Isotropy and statistics of the CMB

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Akrami, Y.; Aluri, P. K.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Basak, S.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bucher, M.; Burigana, C.; Butler, R. C.; Calabrese, E.; Cardoso, J.-F.; Casaponsa, B.; Catalano, A.; Challinor, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Contreras, D.; Couchot, F.; Coulais, A.; Crill, B. P.; Cruz, M.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Désert, F.-X.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Fantaye, Y.; Fergusson, J.; Fernandez-Cobos, R.; Finelli, F.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Frolov, A.; Galeotta, S.; Galli, S.; Ganga, K.; Gauthier, C.; Ghosh, T.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huang, Z.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kim, J.; Kisner, T. S.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leonardi, R.; Lesgourgues, J.; Levrier, F.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; Liu, H.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Marinucci, D.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mikkelsen, K.; Mitra, S.; Miville-Deschênes, M.-A.; Molinari, D.; 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.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Pant, N.; Paoletti, D.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Rotti, A.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, E. P. S.; Souradeep, T.; Spencer, L. D.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Trombetti, T.; Tucci, M.; Tuovinen, J.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Yvon, D.; Zacchei, A.; Zibin, J. P.; Zonca, A.

    2016-09-01

    We test the statistical isotropy and Gaussianity of the cosmic microwave background (CMB) anisotropies using observations made by the Planck satellite. Our results are based mainly on the full Planck mission for temperature, but also include some polarization measurements. In particular, we consider the CMB anisotropy maps derived from the multi-frequency Planck data by several component-separation methods. For the temperature anisotropies, we find excellent agreement between results based on these sky maps over both a very large fraction of the sky and a broad range of angular scales, establishing that potential foreground residuals do not affect our studies. Tests of skewness, kurtosis, multi-normality, N-point functions, and Minkowski functionals indicate consistency with Gaussianity, while a power deficit at large angular scales is manifested in several ways, for example low map variance. The results of a peak statistics analysis are consistent with the expectations of a Gaussian random field. The "Cold Spot" is detected with several methods, including map kurtosis, peak statistics, and mean temperature profile. We thoroughly probe the large-scale dipolar power asymmetry, detecting it with several independent tests, and address the subject of a posteriori correction. Tests of directionality suggest the presence of angular clustering from large to small scales, but at a significance that is dependent on the details of the approach. We perform the first examination of polarization data, finding the morphology of stacked peaks to be consistent with the expectations of statistically isotropic simulations. Where they overlap, these results are consistent with the Planck 2013 analysis based on the nominal mission data and provide our most thorough view of the statistics of the CMB fluctuations to date.

  8. 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…

  9. The 1999 Conference on Molecular Energy Transfer (COMET XVI)

    DTIC Science & Technology

    1999-07-14

    Departamento de Fisicoquimica , Facultad de Ciencias QuImicas, Universidad Nacional de C6rdoba, 5000 C6rdoba, Argentina and Izhack Oref Department of...Monterotondo Scalo Roma - Italia Ferrero, Juan distefan-mlib.cnr.it INFIQC-Departamento de Fisicoquimica Fax: +39-0690672238 Fac.Ciencias Quimicas

  10. Planck intermediate results. XVI. Profile likelihoods for cosmological parameters

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bobin, J.; Bonaldi, A.; Bond, J. R.; Bouchet, F. R.; Burigana, C.; Cardoso, J.-F.; Catalano, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Couchot, F.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dupac, X.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Galli, S.; Ganga, K.; Giard, M.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Harrison, D. L.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Jaffe, A. H.; Jaffe, T. R.; 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.; Lawrence, C. R.; Leonardi, R.; Liddle, 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.; Martin, P. G.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Mazzotta, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Pagano, L.; Pajot, F.; Paoletti, D.; Pasian, F.; Perdereau, O.; Perotto, L.; Perrotta, F.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski∗, S.; Pointecouteau, E.; Polenta, G.; Popa, L.; Pratt, G. W.; Puget, J.-L.; Rachen, J. P.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rouillé d'Orfeuil, B.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Savelainen, M.; Savini, G.; Spencer, L. D.; Spinelli, M.; Starck, J.-L.; Sureau, F.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; White, M.; Yvon, D.; Zacchei, A.; Zonca, A.

    2014-06-01

    We explore the 2013 Planck likelihood function with a high-precision multi-dimensional minimizer (Minuit). This allows a refinement of the ΛCDM best-fit solution with respect to previously-released results, and the construction of frequentist confidence intervals using profile likelihoods. The agreement with the cosmological results from the Bayesian framework is excellent, demonstrating the robustness of the Planck results to the statistical methodology. We investigate the inclusion of neutrino masses, where more significant differences may appear due to the non-Gaussian nature of the posterior mass distribution. By applying the Feldman-Cousins prescription, we again obtain results very similar to those of the Bayesian methodology. However, the profile-likelihood analysis of the cosmic microwave background (CMB) combination (Planck+WP+highL) reveals a minimum well within the unphysical negative-mass region. We show that inclusion of the Planck CMB-lensing information regularizes this issue, and provide a robust frequentist upper limit ∑ mν ≤ 0.26 eV (95% confidence) from the CMB+lensing+BAO data combination.

  11. 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.

  12. Standardization of hormone determinations.

    PubMed

    Stenman, Ulf-Håkan

    2013-12-01

    Standardization of hormone determinations is important because it simplifies interpretation of results and facilitates the use of common reference values for different assays. Progress in standardization has been achieved through the introduction of more homogeneous hormone standards for peptide and protein hormones. However, many automated methods for determinations of steroid hormones do not provide satisfactory result. Isotope dilution-mass spectrometry (ID-MS) has been used to establish reference methods for steroid hormone determinations and is now increasingly used for routine determinations of steroids and other low molecular weight compounds. Reference methods for protein hormones based on MS are being developed and these promise to improve standardization.

  13. 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

  14. Plant Sex Determination.

    PubMed

    Pannell, John R

    2017-03-06

    Sex determination is as important for the fitness of plants as it is for animals, but its mechanisms appear to vary much more among plants than among animals, and the expression of gender in plants differs in important respects from that in most animals. In this Minireview, I provide an overview of the broad variety of ways in which plants determine sex. I suggest that several important peculiarities of plant sex determination can be understood by recognising that: plants show an alternation of generations between sporophytic and gametophytic phases (either of which may take control of sex determination); plants are modular in structure and lack a germ line (allowing for a quantitative expression of gender that is not common in animals); and separate sexes in plants have ultimately evolved from hermaphroditic ancestors. Most theorising about sex determination in plants has focused on dioecious species, but we have much to learn from monecious or hermaphroditic species, where sex is determined at the level of modules, tissues or cells. Because of the fundamental modularity of plant development and potentially important evolutionary links between monoecy and dioecy, it may be useful to relax the distinction often made between 'developmental sex determination' (which underpins the development of male versus female flowers in monoecious species) and 'genetic sex determination' (which underpins the separation of males and females in dioecious species, often mediated by a genetic polymorphism and sex chromosomes). I also argue for relaxing the distinction between sex determination involving a genetic polymorphism and that involving responses to environmental or hormonal cues, because non-genetic cues might easily be converted into genetic switches.

  15. 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.

  16. 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.

  17. Yield-pressure determination

    NASA Technical Reports Server (NTRS)

    Wakefield, M. E.

    1977-01-01

    Stress/strain relationship of complex-shape vessel is recorded under hydrostatic pressure. Technique is used to test pressurized gas cylinders and tubular transition joints made of dissimilar metals and to determine burst or system-failure pressures.

  18. Structural Determination of Circulation.

    ERIC Educational Resources Information Center

    Blankenburg, William B.

    1981-01-01

    Analyzes the effects of both structural factors (demographics, economic conditions, and competition) and discretionary factors (content, design, and marketing techniques) and concludes that it is the former that determine a newspaper's circulation. (FL)

  19. 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.

  20. 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.

  1. Brain Death Determination.

    PubMed

    Spinello, Irene M

    2015-09-01

    In the United States, each year 1% to 2% of deaths are brain deaths. Considerable variation in the practice of determining brain death still remains, despite the publication of practice parameters in 1995 and an evidence-based guideline update in 2010. This review is intended to give bedside clinicians an overview of definition, the causes and pitfalls of misdiagnosing brain death, and a focus on the specifics of the brain death determination process.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

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

    DOE PAGES

    Robinson, David B.; Luo, Weifang; Cai, Trevor Y.; ...

    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

  10. 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)

  11. Determinants of Disciplinary Discontent.

    ERIC Educational Resources Information Center

    Hargens, Lowell L.; Kelly-Wilson, Lisa

    1994-01-01

    Data from the 1984 Carnegie survey of faculty at U.S. universities show substantial disciplinary variation in pessimism that one's field is stagnant. Field-level variations in both anomie and consensus exert strong effects on average levels of scholarly pessimism within fields and are stronger determinants of scholarly pessimism than individual…

  12. 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.

  13. 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.

  14. 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).

  15. Ultrasonic Determination Of Recrystallization

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1988-01-01

    State of recrystallization identified. Measurement of ultrasonic attenuation shows promise as means of detecting recrystallization in metal. Technique applicable to real-time acoustic monitoring of thermomechanical treatments. Starting with work-hardened material, one ultrasonically determines effect of annealing, using correlation between ultrasonic attenuation and temperature.

  16. Determinants of translation ambiguity

    PubMed Central

    Degani, Tamar; Prior, Anat; Eddington, Chelsea M.; Arêas da Luz Fontes, Ana B.; Tokowicz, Natasha

    2016-01-01

    Ambiguity in translation is highly prevalent, and has consequences for second-language learning and for bilingual lexical processing. To better understand this phenomenon, the current study compared the determinants of translation ambiguity across four sets of translation norms from English to Spanish, Dutch, German and Hebrew. The number of translations an English word received was correlated across these different languages, and was also correlated with the number of senses the word has in English, demonstrating that translation ambiguity is partially determined by within-language semantic ambiguity. For semantically-ambiguous English words, the probability of the different translations in Spanish and Hebrew was predicted by the meaning-dominance structure in English, beyond the influence of other lexical and semantic factors, for bilinguals translating from their L1, and translating from their L2. These findings are consistent with models postulating direct access to meaning from L2 words for moderately-proficient bilinguals. PMID:27882188

  17. A robust method for determining the absorbed dose to water in a phantom for low-energy photon radiation

    NASA Astrophysics Data System (ADS)

    Schneider, T.

    2011-06-01

    The application of more and more low-energy photon radiation in brachytherapy—either in the form of low-dose-rate radioactive seeds such as Pd-103 or I-125 or in the form of miniature x-ray tubes—has induced greater interest in determining the absorbed dose to water in water in this energy range. As it seems to be hardly feasible to measure the absorbed dose with calorimetric methods in this low energy range, ionometric methods are the preferred choice. However, the determination of the absorbed dose to water in water by ionometric methods is difficult in this energy range. With decreasing energy, the relative uncertainty of the photon cross sections increases and as the mass energy transfer coefficients show a steep gradient, the spectra of the radiation field must be known precisely. In this work two ionometric methods to determine the absorbed dose to water are evaluated with respect to their sensitivity to the uncertainties of the spectra and of the atomic database. The first is the measurement of the air kerma free in air and the application of an MC-based conversion factor to the absorbed dose to water. The second is the determination of the absorbed dose to water by means of an extrapolation chamber as an integral part of a phantom. In the complementing MC-calculations, two assortments of spectra each of which is based on a separate unfolding procedure were used as well as two kinds of databases: the standard PEGS and the recently implemented NIST database of EGSnrc. Experimental results were obtained by using a parallel-plate graphite extrapolation chamber and a free-air chamber. In the case when the water kerma in a phantom is determined from the measurements of air kerma free in air, differences in the order of 10% were found, according to which the database or the kind of spectrum is used. In contrast to this, for the second method, the differences found were about 0.5%.

  18. Sex determination in Chlamydomonas.

    PubMed

    Goodenough, Ursula; Lin, Huawen; Lee, Jae-Hyeok

    2007-06-01

    The sex-determination system of the unicellular green alga, Chlamydomonas reinhardtii, is governed by genes in the mating-type (MT) locus and entails additional genes located in autosomes. Gene expression is initiated by nitrogen starvation, and cells differentiate into plus or minus gametes within 6h. Reviewed is our current understanding of gametic differentiation and fertilization, initiation of zygote development, and the uniparental inheritance of organelle genomes.

  19. Radio determination satellite service

    NASA Astrophysics Data System (ADS)

    Briskman, Robert D.

    1990-07-01

    The capabilities and measured performance of a geosynchronous satellite-based service called the radio determination satellite service (RDSS), which operates at radio frequencies allocated by the International Telecommunications Union (ITU) and is licensed in the United States by the Federal Communications Commission (FCC), are discussed. Plans for both improvement in capability and expansion to nearly global coverage are described. Since RDSS can also provide radio navigation, some comparisons of this service with the Global Positioning System (GPS) are made.

  20. Statistical initial orbit determination

    SciTech Connect

    Taff, L.G.; Belkin, B.; Schweiter, G.A.; Sommar, K. D.H. Wagner Associates, Inc., Paoli, PA )

    1992-02-01

    For the ballistic missile initial orbit determination problem in particular, the concept of 'launch folders' is extended. This allows to decouple the observational data from the initial orbit determination problem per se. The observational data is only used to select among the possible orbital element sets in the group of folders. Monte Carlo simulations using up to 7200 orbital element sets are described. The results are compared to the true orbital element set and the one a good radar would have been able to produce if collocated with the optical sensor. The simplest version of the new method routinely outperforms the radar initial orbital element set by a factor of two in future miss distance. In addition, not only can a differentially corrected orbital element set be produced via this approach - after only two measurements of direction - but also an updated, meaningful, six-dimensional covariance array for it can be calculated. This technique represents a significant advance in initial orbit determination for this problem, and the concept can easily be extended to minor planets and artificial satellites. 9 refs.

  1. Why social determinants?

    PubMed

    Halfon, Neal; Larson, Kandyce; Russ, Shirley

    2010-01-01

    There is overwhelming evidence that social factors have profound influences on health. Children are particularly sensitive to social determinants, especially in the early years. Life course models view health as a developmental process, the product of multiple gene and environment interactions. Adverse early social exposures become programmed into biological systems, setting off chains of risk that can result in chronic illness in mid-life and beyond. Positive health-promoting influences can set in motion a more virtuous and health-affirming cycle, leading to more optimal health trajectories. Mounting an effective response to social determinants will involve both direct social policy initiatives designed to eliminate poverty and inequality, and indirect approaches focused on disrupting pathways between social risks and poor health outcomes. To be effective, these indirect strategies will require nothing short of a transformation of existing child health systems. Parents and professionals must work together from the ground up, raising public awareness about social determinants of health and implementing cross-sector place-based initiatives designed to promote positive health in childhood.

  2. Design and Analysis of an Attitude Determination and Control Subsystem (ADCS) for AFIT’s 6U Standard Bus

    DTIC Science & Technology

    2014-03-27

    Tool SNU Seoul National University STK Systems Tool Kit SWAP Size, Weight, and Power TFSC Thin Film Solar Cells TLE Two Line Elements xvi Acronym...components. The first component is the Thin Film Solar Cells (TFSC), which has a higher power to mass ratio than conventional solar cells and will be run...sensor equipped with a small solar cell for power and wireless communication. To properly test the payloads on the ground, the Delfi-C3 team required a

  3. 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.

  4. 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.

  5. 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.

  6. Determination of nonaxisymmetric equilibrium

    SciTech Connect

    Elkin, D.

    1980-01-01

    The Princeton Equilibrium Code is modified to determine the equilibrium surfaces for a large aspect ratio toroidal system with helical magnetic fields. The code may easily be made to include any variety of modes. Verification of the code is made by comparison with an analytic solution for l = 3. Previously observed shifting of the magnetic axis with increasing pressure or with a changed externally applied vertical field is obtained. The case l = 0, a bumpy torus, gives convergence only for the lenient convergence tolerance of epsilon/sub b/ = 1.0 x 10-/sup 2/.

  7. Embryonic determination and differentiation.

    PubMed

    Ingram, V M; Keane, R W

    1980-04-01

    At the cellular level, development proceeds in a series of stages in which precursor cells are first restricted in their developmental potential (determination) and subsequently express their genetic information as specific tissues (differentiation). This paper discusses the problems encountered in seeking to understand the molecular mechanisms of thes processes and describes several model systems. A novel approach involves the inhibition of differentiation by virus transformation of the precursor cells in the chick primary mesenchyme, The transformed cells are cloned, grown to large numbers, and then analyzed biochemically.

  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. 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.

  10. Determination of the Structure and Catalytic Mechanism of Sorghum bicolor Caffeic Acid O-Methyltransferase and the Structural Impact of Three brown midrib12 Mutations1[W

    PubMed Central

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

    2014-01-01

    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

  11. 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.

    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.

  12. Determination of Epsomite-Hexahydrite Equilibria by the Humidity-Buffer Technique at 0.1 MPa with Implications for Phase Equilibria in the System MgSO4-H2O

    NASA Astrophysics Data System (ADS)

    Chou, I.-Ming; Seal, Robert R.

    2003-11-01

    Epsomite (MgSO4.7H2O) and hexahydrite (MgSO4.6H2O) 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°C. Results obtained for the reaction epsomite = hexahydrite + H2O, 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.

  13. Adaptive interplanetary orbit determination

    NASA Astrophysics Data System (ADS)

    Crain, Timothy Price

    This work documents the development of a real-time interplanetary orbit determination monitoring algorithm for detecting and identifying changes in the spacecraft dynamic and measurement environments. The algorithm may either be utilized in a stand-alone fashion as a spacecraft monitor and hypothesis tester by navigators or may serve as a component in an autonomous adaptive orbit determination architecture. In either application, the monitoring algorithm serves to identify the orbit determination filter parameters to be modified by an offline process to restore the operational model accuracy when the spacecraft environment changes unexpectedly. The monitoring algorithm utilizes a hierarchical mixture-of-experts to regulate a multilevel bank organization of extended Kalman filters. Banks of filters operate on the hierarchy top-level and are composed of filters with configurations representative of a specific environment change called a macromode. Fine differences, or micromodes, within the macromodes are represented by individual filter configurations. Regulation is provided by two levels of single-layer neural networks called gating networks. A single top-level gating network regulates the weighting among macromodes and each bank uses a gating network to regulate member filters internally. Experiments are conducted on the Mars Pathfinder cruise trajectory environment using range and Doppler data from the Deep Space Network. The experiments investigate the ability of the hierarchical mixture-of-experts to identify three environment macromodes: (1) unmodeled impulsive maneuvers, (2) changes in the solar radiation pressure dynamics, and (3) changes in the measurement noise strength. Two methods of initializing the gating networks are examined in each experiment. One method gives the neurons associated with all filters equivalent synaptic weight. The other method places greater weight on the operational filter initially believed to model the spacecraft environment. The

  14. 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.

  15. Early determinants of obesity.

    PubMed

    Ong, Ken K

    2010-01-01

    High rates of overweight and obesity even in very young children argue the case for strategies to prevent overweight from very young ages. Historical studies, prospective birth cohorts, and more recently genetic studies all indicate that the rapid weight gain trajectory to later obesity starts in the first months of life, even from birth. Early puberty and age at menarche are consequences of rapid infant weight gain and childhood overweight, and in turn these adolescent traits are predictive for obesity, diabetes, hypertension and cardiovascular disease events in later life. Understanding of the nutritional, parental and wider determinants of rapid infant weight gain are informing the development of obesity prevention strategies starting in early life. Such strategies could be further refined by future studies that address the specific regulation of infant adiposity, and also by studies that explore whether these life-course trajectories are modifiable during adolescence.

  16. 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).

  17. 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.

  18. Ultratrace determination of curium

    SciTech Connect

    Beitz, J.V.

    1995-02-01

    Development of a method for detection of curium at near single atom levels is being undertaken as a part of the Advanced Concepts Project at Argonne National Laboratory with funding from the US Department of Energy, Office of Arms Control and Nonproliferation. Ultratrace determination of curium, with the ability to quantify the fraction that is curium-242, provides a signature method of detecting clandestine reprocessing of recently irradiated uranium targets. Curium initially present in any of a variety of materials such as air filters, solid or liquid process waste, soil, flora, or fauna can be recovered via current chemical separations processing techniques. Using the ultratrace method being developed, such recovered curium will be quantified with thousand-fold higher sensitivity than the best currently available method which is alpha counting. This high sensitivity arises because, on average, a given trivalent curium (Cm{sup 3+}) ion can emit a very large number of fluorescence photons before alpha decay occurs.

  19. 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.

  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. Pediatric brain death determination.

    PubMed

    Mathur, Mudit; Ashwal, Stephen

    2015-04-01

    Clinical guidelines for the determination of brain death in children were first published in 1987. These guidelines were revised in 2011 under the auspices of the Society of Critical Care Medicine, the American Academy of Pediatrics, and the Child Neurology Society, and provide the minimum standards that must be satisfied before brain death can be declared in infants and children. After achieving physiologic stability and exclusion of confounders, two examinations including apnea testing separated by an observation period (24 hours for term newborns up to 30 days of age, and 12 hours for infants and children from 31 days up to 18 years) are required to establish brain death. Apnea testing should demonstrate a final arterial PaCO2 20 mm Hg above the baseline and ≥ 60 mm Hg with no respiratory effort during the testing period. Ancillary studies (electroencephalogram and radionuclide cerebral blood flow) are not required to establish brain death and are not a substitute for the neurologic examination. The committee concluded that ancillary studies may be used (1) when components of the examination or apnea testing cannot be completed, (2) if uncertainty about components of the neurologic examination exists, (3) if a medication effect may be present, or (4) to reduce the interexamination observation period. When ancillary studies are used, a second clinical examination and apnea test should still be performed and components that can be completed must remain consistent with brain death.

  2. Epidemiological determinants of psoriasis.

    PubMed

    Islam, M T; Paul, H K; Zakaria, S M; Islam, M M; Shafiquzzaman, M

    2011-01-01

    A cross-sectional study was conducted on 102 cases having clinical manifestation of psoriasis with a view to evaluate the epidemiological determinants of psoriasis. Psoriasis constituted 1.49% of the total dermatological disorder. Seventy patients (68.6%) were males and thirty two (31.4%) were females with a male to female ratio of 2.18:1. The mean age was 30.76±13.17 years in male and 26.94±14.94 years in female. Sixteen (15.7%) patients had one or more family member having psoriasis with male and female in equal frequency. Regarding precipitating factors, psoriasis was developed after trauma in 4.9%, infection 3.9%, stressful life events 6.9% and drugs 2.9%; and was exacerbated after trauma in 5.9%, infection 5.9%, stressful life events 35.3% and drugs 12.7%. The disease showed improvement in summer (27.5%) and found deteriorated in winter (47.1%). Sunlight had beneficial effect in 33.3% of cases. During pregnancy improvement was observed in 50% but flare up in 22.2% of cases. Fifty percent of patients were smokers, 41.2% were non-smokers and 13.7% were ex-smokers. Forty percent had Body Mass Index (BMI) between 22 to 26 Kg/m², 40.2% had less than 22 Kg/m² and 15.7% had above 26 Kg/m². It was concluded that the prevalence of psoriasis among dermatological patients was similar to results reported in Turkey and in Northern India. The precipitating factors, such as smoking, stressful life events, infection, trauma, sunlight, pregnancy, drugs, and seasonal variations could influence the development of psoriasis and affect its clinical expression.

  3. Determinants of lemming outbreaks.

    PubMed

    Ims, Rolf A; Yoccoz, Nigel G; Killengreen, Siw T

    2011-02-01

    Population outbreaks in tundra rodents have intrigued scientists for a century as a result of their spectacular appearances and their general lessons in ecology. One outstanding question that has led to competing hypotheses is why sympatric lemmings and voles differ in regularity and shape of their outbreaks. Lemming outbreaks may be lost for decades while vole populations maintain regular population cycles. Moreover, when lemming populations eventually irrupt, they do so more steeply than the vole populations. Norwegian lemmings exhibited a large-scale outbreak synchronously with gray-sided voles in Finnmark, northern Fennoscandia, during 2006 to 2007 for the first time in two decades. Analyses of spatial variability of this outbreak across altitudinal gradients allowed us to identify determinants of the contrasting lemming and vole dynamics. The steeper lemming outbreak trajectories were caused by breeding and population growth during winter, when nonbreeding vole populations consistently declined. The differently shaped lemming and vole outbreaks appear to result from a particular demographic tactic of lemmings that evolved as an adaptation to the long and cold Arctic-Alpine winters. The lemming outbreak amplitude increased with altitude and vole density, indicating that lemming outbreaks are jointly facilitated by low temperatures and apparent mutualism with voles mediated by shared predators. High sensitivity to variation in climate and predation is likely to be the reasons why lemmings have more erratic population dynamics than sympatric voles. The combination of continued climatic warming and dampened vole cycles is expected to further decrease the frequency, amplitude, and geographic range of lemming outbreaks in tundra ecosystems.

  4. 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.

  5. 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.

  6. 29 CFR 2590.606-1 - General notice of continuation coverage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... administrator of a determination by the Social Security Administration, under title II or XVI of the Social... of this chapter, including paragraph (c) of that section relating to the use of electronic media....

  7. 29 CFR 2590.606-1 - General notice of continuation coverage.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... administrator of a determination by the Social Security Administration, under title II or XVI of the Social... of this chapter, including paragraph (c) of that section relating to the use of electronic media....

  8. 29 CFR 2590.606-1 - General notice of continuation coverage.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... administrator of a determination by the Social Security Administration, under title II or XVI of the Social... of this chapter, including paragraph (c) of that section relating to the use of electronic media....

  9. 29 CFR 2590.606-1 - General notice of continuation coverage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... administrator of a determination by the Social Security Administration, under title II or XVI of the Social... of this chapter, including paragraph (c) of that section relating to the use of electronic media....

  10. 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.

  11. Determinants of Service Contract Outcomes

    DTIC Science & Technology

    2011-04-30

    distribution unlimited. Prepared for the Naval Postgraduate School, Monterey, California 93943 NPS-AM-11-C8P08R01-036 Determinants of Service...2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Determinants of Service Contract Outcomes 5a. CONTRACT NUMBER...specification and measurement of contractor performance problematic. Despite these difficulties, little research has been conducted to examine the determinants

  12. Perchlorate Regulatory Determination Fact Sheets

    EPA Pesticide Factsheets

    Fact sheets have been developed for the perchlorate regulatory determination corresponding to the following stages published in the Federal Register: Final, Supplemental request for comments, and Preliminary.

  13. Determination of body heat storage: how to select the weighting of rectal and skin temperatures for clothed subjects.

    PubMed

    Aoyagi, Y; McLellan, T M; Shephard, R J

    1996-01-01

    Two methods of estimating body heat storage were compared under differing conditions of clothing and acclimation to heat. Sixteen male subjects underwent 6 consecutive days or two 6-day periods, separated by a 1-day rest period of heat acclimation, exercising 60 min.day-1 at 45%-55% of maximal aerobic power in a hot, dry environment (dry bulb temperature 40 degrees C; relative humidity 30%; and wind speed 0.3 m.s-1). Before and after acclimation, the subjects entered the same environment, wearing either normal light combat clothing or clothing protective against nuclear, biological, and chemical agents; they walked on a treadmill at 1.34 m.s-1, 0% slope continuously (n = 11 for normal clothing) or as repeated 15-min bouts of exercise followed by 15-min sitting rest (n = 5 for normal clothing and n = 16 for protective clothing). Average exposure times were 147 min (preacclimation) and 150 min (postacclimation) for continuous exercise and 150 min (both pre- and postacclimation) for intermittent exercise while wearing normal clothing, and 103 min (preacclimation) and 116 min (postacclimation) for intermittent exercise while wearing protective clothing. Heat storage was determined calorimetrically (from heat gains and heat losses) and thermometrically [using various weightings of rectal temperature (Tre) and mean skin temperature (Tsk)]. There were only minor (<5%) differences in estimated heat storage, whether calculations used a single specific heat (3.47 kJ.kg-1.degree C-1) or a value computed according to the subject's body composition. When wearing normal clothing, a formula with an invariant relative weighting for Tre to Tsk of 4:1 provided the best thermometric estimate of heat storage. When wearing protective clothing, the invariant relative weighting of 4:1 underestimated heat storage by 2%-12%; underestimation was attenuated by using respective relative weightings for a thermoneutral and hot environment of 2:1 and 2:1 or 4:1 and 9:1 before acclimation and 4

  14. 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…

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. Thorium: Determination by CDTN, Brazil

    NASA Astrophysics Data System (ADS)

    Menezes, M. A. B. C.; Sabino, C. V. S.

    1999-01-01

    One of the tasks of the Radiochemical Sector, CDTN/CNEN, Brazil, is to meet the clients' analytical needs. The Sector has been facing the challenges of determining several elements in diversified matrixes from all over the country since the sixties. It has been giving analytical support to universities, industries, environmental monitoring programs, research institutes. Due to the growing need to determine thorium isotopes through the years it was necessary to work out a routine procedures. Nowadays the determination of thorium consists of a well established routine whose procedures are applied to grouped samples according to their kind, physical state, matrix interference, detection limits and number of samples. This paper describes the methods used by CDTN to determine232Th by neutron activation analysis and230Th and228Th by radiochemical separations and alpha spectrometry in several matrixes.

  1. 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.

  2. 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.

  3. Determining Hostile Intent in Cyberspace

    DTIC Science & Technology

    2014-01-01

    signal corps evolved to encrypt , trans- mit, receive, and handle messages, first at the rate of the written word and the horse, then at the rate of...approach where the “ quantum of damage and not the means of attack” determines if an action in cyberspace is a prohibited use of force.10 This approach...a quantum -of- damage approach is used, the critical question would be who determines what a sufficient amount of damage is to con- stitute a

  4. Sex determination in flowering plants.

    PubMed Central

    Dellaporta, S L; Calderon-Urrea, A

    1993-01-01

    In many ways, plants offer unique systems through which to study sex determination. Because the production of unisexual flowers has evolved independently in many plant species, different and novel mechanisms may be operational. Hence, there is probably not one unifying mechanism that explains sex determination in plants. Advances in our understanding of sex determination will come from the analysis of the genetics, molecular biology, and biochemistry of genes controlling sexual determination in plants. Several excellent model systems for bisexual floral development (Arabidopsis and Antirrhinum), monoecy (maize), and dioecy (Silene, asparagus, and mercury) are available for such analyses. The important questions that remain concern the mechanism of action of sex determination genes and their interrelationship, if any, with homeotic genes that determine the sexual identity of floral organ primordia. At the physiological level, the connection between hormone signaling and sexuality is not well understood, although significant correlations have been discovered. Finally, once the genes that regulate these processes are identified, cloned, and studied, new strategies for the manipulation of sexuality in plants should be forthcoming. PMID:8281039

  5. 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.

  6. [Determination of HDL-cholesterol].

    PubMed

    Herrmann, W; Schütz, C; Reuter, W

    1983-01-01

    For the clinical practice methods of the determination of HDL-cholesterol made their way which are based on the precipitation of apolipoprotein-B-containing lipoproteins and a determination of cholesterol following. The expensive methods of the ultracentrifugation serve as reference methods. The most-spread precipitation techniques (heparin/MCl2, dextran sulphate/CaCl2 or MgCl2 photungstic acid/MgCl2) are comparatively observed with regard to their effectiveness, practicability and methodical and technical conditions (influence of the concentration of the precipitation reagents, pH-value, temperature, incubation and centrifugation conditions). Results of own investigations as well as data from literature are presented to the problem of the harmonization of the cholesterol determination with the precipitation technique. According to the opinion of the authors for the enzymatic determination of cholesterol by means of the CHOD-PAP-method the phosphotungstic acid precipitation well stood the test, whereas for the chemical determination of cholesterol after Liebermann-Burchard in manual or automatized works the precipitation by means of dextran sulphate/CaCl2 (40 g/l, 2.0 mol/l) is to be recommended. The superabundant precipitations with phosphotungstic acid and dextran sulphate/MgCl2 (20 g/l, 2.0 mol/l) achieve higher results in Liebermann-Burchard's reaction likely on account of interferences.

  7. 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…

  8. 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.

  9. Spherical Dirac GJMS operator determinants

    NASA Astrophysics Data System (ADS)

    Dowker, J. S.

    2015-01-01

    Motivated by AdS/CFT, the extension is made to spin-half of a scalar calculation of the conformal anomalies and functional determinants of GJMS operators on spheres. The formal aspects are heuristic but sufficient. A Barnes zeta-function representation again proves effective. The determinants are calculated for the two factorizations of the general Γ-function (intertwiner) form of the GJMS operator, and shown to be equal, even including any multiplicative anomaly. A comment is made on the general eigenvalue problem and a few numerical results are presented. An alternative approach is detailed for odd dimensions and it is shown that the scalar determinants are expressed in terms of the spinor ones, and vice versa. An explicit, general form is given.

  10. Lessons for inductive germline determination.

    PubMed

    Seervai, Riyad N H; Wessel, Gary M

    2013-08-01

    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.

  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. 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.

  13. 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.

  14. 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.

  15. Sex determination using maxillary sinus

    PubMed Central

    Kanthem, Ranjith Kumar; Guttikonda, Venkateswara Rao; Yeluri, Sivaranjani; Kumari, Geetha

    2015-01-01

    Background: Individual identification is a subtle concept and often one of the most important priorities in mass disasters, road accidents, air crashes, fires, and even in the investigation of criminal cases. Matching specific features detected on the cadaver with data recorded during the life of an individual is an important aspect in forensics, and can be performed by fingerprint analysis, deoxyribonucleic acid matching, anthropological methods, radiological methods and other techniques which can facilitate age and sex identification. Sinus radiography is one such method that has been used for determination of the sex of an individual. Hence, an attempt is being made to use the different dimensions of the maxillary sinus in the determination of sex using coronal and axial sections of plain computed tomography (CT) scan. Materials and Methods: A total of 30 patients including 17 male and 13 female, visiting the Outpatient Department of the Mamata General Hospital were included as the study subjects. The dimensions of right and left maxillary sinuses of 30 subjects from plain CT were measured using SYNGO software and statistical analysis was done. Results: Sex determination using height, length, width, and volume of the maxillary sinus on both sides showed statistically significant results with a higher percentage of sexual dimorphism in the case of volume. Conclusion: Volume of the right maxillary sinus can be used as accurate diagnostic parameter for sex determination. PMID:26005308

  16. 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…

  17. 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…

  18. 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…

  19. 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.

  20. Time domain period determination techniques

    NASA Technical Reports Server (NTRS)

    Stellingwerf, R. F.

    1980-01-01

    Two simple period determination schemes are discussed. They are well suited to problems involving non-sinusoidal periodic phenomena sampled at a few irregularly spaced points. Statistical properties are discussed. The techniques are applied to the double mode Cepheids BK Cen and TU Cas as test cases.

  1. 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…

  2. 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.

  3. Determining Learning Disabilities in Mathematics.

    ERIC Educational Resources Information Center

    Dunlap, William P.; And Others

    1979-01-01

    To determine the generalizability of reading expectancy formulas in ascertaining mathematics expectancy levels, correlation coefficients were computed between the scores of 150 Ss (7 to 12 years old) with learning problems on standardized mathematics and reading tests and expectancy scores. Formulas correlated higher with Ss' actual mathematics…

  4. Determination of nominal accelerating potential

    SciTech Connect

    Nizin, P.; Kase, K.

    1986-11-01

    We present a simple linear relationship between the nominal accelerating potential (NAP) and the ratios of ionization measurements made with constant source--detector distance and at two different phantom thicknesses. This relationship can be used as a standard, unambiguous method for determining NAP for use in dosimetry and quality control.

  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. Time domain period determination techniques

    NASA Astrophysics Data System (ADS)

    Stellingwerf, R. F.

    1980-05-01

    Two simple period determination schemes are discussed. They are well suited to problems involving non-sinusoidal periodic phenomena sampled at a few irregularly spaced points. Statistical properties are discussed. The techniques are applied to the double mode Cepheids BK Cen and TU Cas as test cases.

  7. Immunobiological determinants in organ transplantation.

    PubMed Central

    Marks, C.

    1983-01-01

    The most important development in determining successful organ transplantation has been the improved understanding of the immune response and the interactions between antigens, antibody, immune complexes, complement component, lymphocytes and macrophages. The initiation and termination of an immune response, whether cellular or humoral depends upon cellular interaction between subsets of the lymphocyte cell series and macrophages. An equilibrium between helper and suppressor T cells determines protection of the host from non-self tissue invasion, infection and neoplasia. The role of mediators, immunosuppressants, hybridomas and recombitant DNA technology are briefly considered. The relative importance of tissue typing and blood transfusion in preventing allograft rejection is considered and the role of immunological monitoring in allograft transplantation is reviewed. PMID:6344730

  8. 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).

  9. Genetic determinants of glucose homeostasis.

    PubMed

    Barker, Adam; Langenberg, Claudia; Wareham, Nicholas J

    2012-04-01

    Type 2 diabetes is a complex metabolic disorder characterised by varying degrees of impairment in insulin secretion and resistance to the action of insulin. Considerable progress has been made recently in understanding the genetic determinants of diabetes. A logical next step is to describe how these variants relate to the underlying pathophysiological processes that lead to diabetes as this may provide insights into pathways to disease. These quantitative traits are, of course, of direct interest in themselves and a growing literature is now emerging on the genetic determinants of insulin secretion and insulin resistance. This review article focuses on describing the complex associations between type 2 diabetes risk variants and quantitative glycaemic traits and the relationship between variants initially discovered in association studies of these traits and risk of type 2 diabetes.

  10. [Determination of aflatoxins in cheeses].

    PubMed

    Bartos, J; Matyás, Z

    1979-03-01

    To investigate cheeses for the presence of aflatoxins we chose the very sensitive method of Tuinstra and Bronsgeest (1975) used for the determination of aflatoxin M1 in milk. The method was slightly modified and the presence of aflatoxins was determined in 54 samples of different cheeses. Aflatoxin M1 was found out in 24% of the investigated samples. Most of positive samples were found among the soft cheeses (53.8 3/4), then in processed cheeses (13.6%) and in hard cheeses (12.5%). Aflatoxin M1 was not found in the group of mouldy cheeses and Olomouc cake cheeses, which were investigated in a smaller range. Positive findings did not exceed concentrations of 10 ng per kg, i.e. they did not even reach the value of permissible concentration as proposed in the Czech Socialist Republic for foods (5 microgram per kg).

  11. System for determining aerodynamic imbalance

    NASA Technical Reports Server (NTRS)

    Churchill, Gary B. (Inventor); Cheung, Benny K. (Inventor)

    1994-01-01

    A system is provided for determining tracking error in a propeller or rotor driven aircraft by determining differences in the aerodynamic loading on the propeller or rotor blades of the aircraft. The system includes a microphone disposed relative to the blades during the rotation thereof so as to receive separate pressure pulses produced by each of the blades during the passage thereof by the microphone. A low pass filter filters the output signal produced by the microphone, the low pass filter having an upper cut-off frequency set below the frequency at which the blades pass by the microphone. A sensor produces an output signal after each complete revolution of the blades, and a recording display device displays the outputs of the low pass filter and sensor so as to enable evaluation of the relative magnitudes of the pressure pulses produced by passage of the blades by the microphone during each complete revolution of the blades.

  12. Cytokine determinants of viral tropism.

    PubMed

    McFadden, Grant; Mohamed, Mohamed R; Rahman, Masmudur M; Bartee, Eric

    2009-09-01

    The specificity of a given virus for a cell type, tissue or species - collectively known as viral tropism - is an important factor in determining the outcome of viral infection in any particular host. Owing to the increased prevalence of zoonotic infections and the threat of emerging and re-emerging pathogens, gaining a better understanding of the factors that determine viral tropism has become particularly important. In this Review, we summarize our current understanding of the central role of antiviral and pro-inflammatory cytokines, particularly the interferons and tumour necrosis factor, in dictating viral tropism and how these cytokine pathways can be exploited therapeutically for cancer treatment and to better counter future threats from emerging zoonotic pathogens.

  13. 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.

  14. 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.

  15. System for determining biofuel concentration

    DOEpatents

    Huff, Shean P.; Janke, Christopher James; Kass, Michael D.; Lewis, Sr, Samuel Arthur; Pawel, Steven J; Theiss, Timothy J.

    2016-09-13

    A measurement device or system configured to measure the content of biofuels within a fuel blend. By measuring a state of a responsive material within a fuel blend, a biofuel content of the fuel blend may be measured. For example, the solubility of a responsive material to biofuel content within a fuel blend, may affect a property of the responsive material, such as shape, dimensional size, or electrical impedance, which may be measured and used as a basis for determining biofuel content.

  16. 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.

  17. 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.

  18. 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.

  19. Rate determination from vector observations

    NASA Technical Reports Server (NTRS)

    Weiss, Jerold L.

    1993-01-01

    Vector observations are a common class of attitude data provided by a wide variety of attitude sensors. Attitude determination from vector observations is a well-understood process and numerous algorithms such as the TRIAD algorithm exist. These algorithms require measurement of the line of site (LOS) vector to reference objects and knowledge of the LOS directions in some predetermined reference frame. Once attitude is determined, it is a simple matter to synthesize vehicle rate using some form of lead-lag filter, and then, use it for vehicle stabilization. Many situations arise, however, in which rate knowledge is required but knowledge of the nominal LOS directions are not available. This paper presents two methods for determining spacecraft angular rates from vector observations without a priori knowledge of the vector directions. The first approach uses an extended Kalman filter with a spacecraft dynamic model and a kinematic model representing the motion of the observed LOS vectors. The second approach uses a 'differential' TRIAD algorithm to compute the incremental direction cosine matrix, from which vehicle rate is then derived.

  20. Spectrophotometric determination of phosphorus acid

    SciTech Connect

    Domin, A.V.; Domina, N.G.; Zakharov, Yu.A.; Shechkov, G.T.

    1987-03-01

    A number of procedures have been proposed to determine phosphorus acid and its salts, the phosphites, in the presence of hypophosphorus acid and its salts, the hypophosphites. Among these procedures, iodometric back-titration has produced the most reliable results. In this paper, the authors propose an improved iodometric determination of phosphorus acid that enables the sensitivity to be increased by at least two orders of magnitude. The essence of this improvement is that excess iodine that did not react with phosphite ion is determined not volumetrically but spectrophotometrically. To eliminate the effect of iodine ion that is liberated when iodine reacts with phosphite ion on the optical density of the solution, a 200-fold excess of potassium iodide is added before the photometric measurement. The working iodine solution is prepared by diluting 10 m of 0.025 N iodine titrant and 50 ml of phosphate buffer, pH 6.7-7.2, to 1 liter with distilled water in a coulometric flask. To construct the calibration curve, 5, 10, 15, 20, and 25 ml, respectively of working iodine solution, and 10 ml of 2% aqueous potassium iodide are placed into five 100-ml volumetric flasks, and the solutions are made up to volume with water. After 10 min the photometric measurements are carried out at 380 nm using curvets and the reference solution is obtained by diluting 10 ml of 2% aqueous potassium iodide to 100 ml with distilled water.

  1. [Monitoring social determinants of health].

    PubMed

    Espelt, Albert; Continente, Xavier; Domingo-Salvany, Antonia; Domínguez-Berjón, M Felicitas; Fernández-Villa, Tania; Monge, Susana; Ruiz-Cantero, M Teresa; Perez, Glòria; Borrell, Carme

    2016-11-01

    Public health surveillance is the systematic and continuous collection, analysis, dissemination and interpretation of health-related data for planning, implementation and evaluation of public health initiatives. Apart from the health system, social determinants of health include the circumstances in which people are born, grow up, live, work and age, and they go a long way to explaining health inequalities. A surveillance system of the social determinants of health requires a comprehensive and social overview of health. This paper analyses the importance of monitoring social determinants of health and health inequalities, and describes some relevant aspects concerning the implementation of surveillance during the data collection, compilation and analysis phases, as well as dissemination of information and evaluation of the surveillance system. It is important to have indicators from sources designed for this purpose, such as continuous records or periodic surveys, explicitly describing its limitations and strengths. The results should be published periodically in a communicative format that both enhances the public's ability to understand the problems that affect them, whilst at the same time empowering the population, with the ultimate goal of guiding health-related initiatives at different levels of intervention.

  2. Determination of human chorionic gonadotropin.

    PubMed

    Stenman, Ulf-Håkan; Alfthan, Henrik

    2013-12-01

    Determination of human chorionic gonadotropin (hCG) is used for diagnosis and monitoring of pregnancy, pregnancy related disorders, for trophoblastic and some nontrophoblastic tumors. In addition, hCG is determined for doping control in males. Assay of hCG is complicated by the occurrence of different molecular forms, which are detected to various degrees by different assays. The main form of hCG in circulation and in patients with trophoblastic tumors is intact heterodimeric hCG. The free β subunit (hCGβ) is a minor form in plasma in both conditions, but it may be the major form aggressive trophoblastic cancer. Therefore, assays measuring hCG and hCGβ together are mainly used for diagnosis of pregnancy and trophoblastic diseases. When excreted into urine, most of hCG (and hCGβ) is broken down to the core fragment of hCGβ (hCGβcf), which is the main immunoreactive form of hCG in urine during pregnancy. Specific determination of hCGβ is of value in screening for Down's syndrome and diagnosis of nontrophoblastic cancer. hCGbcf is of limited utility but it is important because it may disturb assay of hCG in pregnancy.

  3. Efficient, sparse biological network determination

    PubMed Central

    August, Elias; Papachristodoulou, Antonis

    2009-01-01

    Background Determining the interaction topology of biological systems is a topic that currently attracts significant research interest. Typical models for such systems take the form of differential equations that involve polynomial and rational functions. Such nonlinear models make the problem of determining the connectivity of biochemical networks from time-series experimental data much harder. The use of linear dynamics and linearization techniques that have been proposed in the past can circumvent this, but the general problem of developing efficient algorithms for models that provide more accurate system descriptions remains open. Results We present a network determination algorithm that can treat model descriptions with polynomial and rational functions and which does not make use of linearization. For this purpose, we make use of the observation that biochemical networks are in general 'sparse' and minimize the 1-norm of the decision variables (sum of weighted network connections) while constraints keep the error between data and the network dynamics small. The emphasis of our methodology is on determining the interconnection topology rather than the specific reaction constants and it takes into account the necessary properties that a chemical reaction network should have – something that techniques based on linearization can not. The problem can be formulated as a Linear Program, a convex optimization problem, for which efficient algorithms are available that can treat large data sets efficiently and uncertainties in data or model parameters. Conclusion The presented methodology is able to predict with accuracy and efficiency the connectivity structure of a chemical reaction network with mass action kinetics and of a gene regulatory network from simulation data even if the dynamics of these systems are non-polynomial (rational) and uncertainties in the data are taken into account. It also produces a network structure that can explain the real experimental

  4. 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

  5. Dietary Determinants of Prostate Cancer

    DTIC Science & Technology

    2005-03-01

    no additional Genistein or SIT and omega FA ratio of 48 omega- 6:1 omega - 3 ), FA ratio of 25 omega-6: 1 omega - 3 , 1% SIT, or 0.02% Genistein diets. This...was done to determine if the test compounds will affect the implantation of the tumor cells. In addition, omega FA ratios of omega-6: omega - 3 for the...FA test diet needed to be reduced (as opposed to increased as originally planned) due to the high omega-6: omega - 3 ratio of the control diet (as in

  6. Determination of triclosan in foodstuffs.

    PubMed

    Sanches-Silva, Ana; Sendón-García, Raquel; López-Hernández, Julia; Paseiro-Losada, Perfecto

    2005-01-01

    A reverse-phase high-performance liquid chromatographic (RP-HPLC) method coupled with an ultraviolet detector was developed to determine triclosan which had migrated into foodstuffs from packaging materials. The method includes extraction with hexane, followed by evaporation to dryness and residue re-dissolution in ACN 90%. Chromatographic separation was performed with a Kromasil 100 C18 column (15 cm x 0.4 cm ID, 5 microm particle size) at 30 degrees C and using ACN and water as mobile phases. Regarding recoveries, good results (higher than 83% and lower than 112%) were obtained for the three representative food matrixes selected (orange juice, chicken breast meat, and Gouda cheese).

  7. Structure determination of enterovirus 71

    SciTech Connect

    Plevka, Pavel; Perera, Rushika; Cardosa, Jane; Kuhn, Richard J.; Rossmann, Michael G.

    2013-02-20

    Enterovirus 71 is a picornavirus that causes hand, foot and mouth disease but may induce fatal neurological illness in infants and young children. Enterovirus 71 crystallized in a body-centered orthorhombic space group with two particles in general orientations in the crystallographic asymmetric unit. Determination of the particle orientations required that the locked rotation function excluded the twofold symmetry axes from the set of icosahedral symmetry operators. This avoided the occurrence of misleading high rotation-function values produced by the alignment of icosahedral and crystallographic twofold axes. Once the orientations and positions of the particles had been established, the structure was solved by molecular replacement and phase extension.

  8. Genetic modification and genetic determinism.

    PubMed

    Resnik, David B; Vorhaus, Daniel B

    2006-06-26

    In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions.

  9. 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.

  10. Determination of pigments in vegetables.

    PubMed

    Schoefs, Benoît

    2004-10-29

    Plant pigments are responsible for the shining color of plant tissues. They are also found in animal tissues and, eventually in transformed food products as additives. These pigments have an important impact on the commercial value of products, because the colors establish the first contact with the consumer. In addition plant pigments may have an influence on the health of the consumers. Pigments are labile: they can be easily altered, and even destroyed. Analytical processes have been developed to determine pigment composition. The aim of this paper is to provide a brief overview of these methods.

  11. SOP - Determination of Requirement Density

    SciTech Connect

    Reynolds, John G.; Martz, Jr., Harry E.

    2010-10-26

    The purpose of this Standard Operating Procedure (SOP) is to give guidelines on how to determine the density of a sample that will be used as the requirement density. This will be the requirement density of record for the specimens examined by Micro CT and EDS measurements. This density will then be set as the formulation requirement for radiography measurements. This SOP is referred to in TP 48— Preparation of Hydrogen Peroxide/Icing Sugar Specimens for X-ray Measurements by J. G. Reynolds and H. E. Martz.

  12. Method for determining astronomic azimuth

    NASA Astrophysics Data System (ADS)

    Evans, Alan G.; Stein, William L.

    1990-09-01

    An improved method is disclosed for fixing position of a land based target site with respect to a reference site in the natural coordinate frame comprising the steps of determining geodetic azimuth between the target site and the reference target using Global Positioning System (GPS) satellites and relative positioning survey techniques; then calculating a relationship using gravity vertical deflections; and then converting the geodetic azimuth to astronomic azimuth. This method has several advantages over conventional methods of targeting, including speed, the ability to work in all weather conditions, and improved accuracy.

  13. Determinants of fertility in Guatemala.

    PubMed

    Anderson, J E; Morris, L; Pineda, A; Santiso, R

    1980-01-01

    The 1978 Contraceptive Prevalence Survey for Guatemala provides an opportunity to examine fertility levels and a number of determinants of fertility for three broad segments of the country: the Department of Guatemala and, in the remainder of the country, the Ladino and Indian populations. While Ladinos had a much higher rate of contraceptive use than did Indians, the two groups had similar birth rates. The lack of difference in fertility appears to be due to the pattern of prolonged breastfeeding among Indians and perhaps to differences in the rate of conception due to nutrition, coital frequency, or other factors.

  14. Genetic modification and genetic determinism

    PubMed Central

    Resnik, David B; Vorhaus, Daniel B

    2006-01-01

    In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions. PMID:16800884

  15. 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.

  16. Medical Qualification Determinations. Final rule.

    PubMed

    2017-01-18

    The U.S. Office of Personnel Management (OPM) is issuing a final rule to revise its regulations for medical qualification determinations. The revised regulations update references and language; add and modify definitions; clarify coverage and applicability; address the need for medical documentation and medical examination and/or testing for an applicant or employee whose position may or may not have medical standards and/or physical requirements; and recommend the establishment of agency medical review boards. The final rule provides agencies guidance regarding medical evaluation procedures.

  17. 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.

  18. 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.

  19. 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.

  20. Sry, more than testis determination?

    PubMed

    Turner, Monte E; Ely, Daniel; Prokop, Jeremy; Milsted, Amy

    2011-09-01

    The Sry locus on the mammalian Y chromosome is the developmental switch responsible for testis determination. Inconsistent with this important function, the Sry locus is transcribed in adult males at times and in tissues not involved with testis determination. Sry is expressed in multiple tissues of the peripheral and central nervous system. Sry is derived from Sox3 and is similar to other SOXB family loci. The SOXB loci are responsible for nervous system development. Sry has been demonstrated to modulate the catecholamine pathway, so it should have functional consequences in the central and peripheral nervous system. The nervous system expression and potential function are consistent with Sry as a SOXB family member. In mammals, Sox3 is X-linked and undergoes dosage compensation in females. The expression of Sry in adult males allows for a type of sexual differentiation independent of circulating gonadal hormones. A quantitative difference in Sox3 plus Sry expression in males vs. females could drive changes in the transcriptome of these cells, differentiating male and female cells. Sry expression and its transcriptional effects should be considered when investigating sexual dimorphic phenotypes.

  1. The determinants of food choice.

    PubMed

    Leng, Gareth; Adan, Roger A H; Belot, Michele; Brunstrom, Jeffrey M; de Graaf, Kees; Dickson, Suzanne L; Hare, Todd; Maier, Silvia; Menzies, John; Preissl, Hubert; Reisch, Lucia A; Rogers, Peter J; Smeets, Paul A M

    2016-12-01

    Health nudge interventions to steer people into healthier lifestyles are increasingly applied by governments worldwide, and it is natural to look to such approaches to improve health by altering what people choose to eat. However, to produce policy recommendations that are likely to be effective, we need to be able to make valid predictions about the consequences of proposed interventions, and for this, we need a better understanding of the determinants of food choice. These determinants include dietary components (e.g. highly palatable foods and alcohol), but also diverse cultural and social pressures, cognitive-affective factors (perceived stress, health attitude, anxiety and depression), and familial, genetic and epigenetic influences on personality characteristics. In addition, our choices are influenced by an array of physiological mechanisms, including signals to the brain from the gastrointestinal tract and adipose tissue, which affect not only our hunger and satiety but also our motivation to eat particular nutrients, and the reward we experience from eating. Thus, to develop the evidence base necessary for effective policies, we need to build bridges across different levels of knowledge and understanding. This requires experimental models that can fill in the gaps in our understanding that are needed to inform policy, translational models that connect mechanistic understanding from laboratory studies to the real life human condition, and formal models that encapsulate scientific knowledge from diverse disciplines, and which embed understanding in a way that enables policy-relevant predictions to be made. Here we review recent developments in these areas.

  2. Secondary structure determines protein topology

    PubMed Central

    Fleming, Patrick J.; Gong, Haipeng; Rose, George D.

    2006-01-01

    Using a test set of 13 small, compact proteins, we demonstrate that a remarkably simple protocol can capture native topology from secondary structure information alone, in the absence of long-range interactions. It has been a long-standing open question whether such information is sufficient to determine a protein's fold. Indeed, even the far simpler problem of reconstructing the three-dimensional structure of a protein from its exact backbone torsion angles has remained a difficult challenge owing to the small, but cumulative, deviations from ideality in backbone planarity, which, if ignored, cause large errors in structure. As a familiar example, a small change in an elbow angle causes a large displacement at the end of your arm; the longer the arm, the larger the displacement. Here, correct secondary structure assignments (α-helix, β-strand, β-turn, polyproline II, coil) were used to constrain polypeptide backbone chains devoid of side chains, and the most stable folded conformations were determined, using Monte Carlo simulation. Just three terms were used to assess stability: molecular compaction, steric exclusion, and hydrogen bonding. For nine of the 13 proteins, this protocol restricts the main chain to a surprisingly small number of energetically favorable topologies, with the native one prominent among them. PMID:16823044

  3. [Determination of uranium in spinach].

    PubMed

    Kishi, Eri; Yutani, Aiko; Ozaki, Asako; Shinya, Masanao; Katahira, Kenshi; Ooshima, Tomoko; Shimizu, Mitsuru

    2013-01-01

    After the severe accident at the Fukushima-1 Nuclear Power Plant in March 2011, radioactive contamination of food has become a matter of serious concern in Japan. There is considerable information about radioactive iodine and cesium, but little is known about uranium contamination. We determined uranium content in spinach by the Japanese official method (Manual on Radiation Measurement of Food in Emergency Situations). In the preliminary study, we confirmed that the use of a microwave digestion system for preparing the test solution of spinach could shorten the testing time and give acceptable results. The manual recommends the use of two elements (Tl and Bi) as internal standards for measurement of uranium by ICP-MS. We found that Tl was more suitable than Bi to quantify trace amounts of uranium in spinach. However, it was necessary to determine Tl or Bi concentrations in the sample before analysis, since some samples of spinach contained significant amounts of these elements. The uranium contents of 9 spinach samples bought in April and May 2011 were less than 10 μg/kg, which are very low compared to the provisional regulatory limit in Japan.

  4. Determination of Silicon in Hydrazine

    NASA Technical Reports Server (NTRS)

    McClure, Mark B.; Mast, Dion; Greene, Ben; Maes, Miguel J.

    2006-01-01

    Inductively coupled plasma-mass spectrometry (ICP-MS) is a highly sensitive technique sometimes used for the trace determination of silicon at a mass-to-charge (m/z) ratio of 28, the most abundant natural isotope of silicon. Unfortunately, ICP-MS is unable to differentiate between other sources of m/z 28 and false positive results for silicon will result when other sources of m/z 28 are present. Nitrogen was a major source of m/z 28 and contributes to the m/z 28 signal when hydrazine sample or nitric acid preservative is introduced into the plasma. Accordingly, this work was performed to develop a sample preparation step coupled with an ICP-MS analysis that minimized non-silicon sources of m/z 28. In the preparatory step of this method, the hydrazine sample was first decomposed predominately to nitrogen gas and water with copper-catalyzed hydrogen peroxide. In the analysis step, ICP-MS was used without nitric acid preservative in samples or standards. Glass, a potential source of silicon contamination, was also avoided where possible. The method was sensitive, accurate, and reliable for the determination of silicon in monopropellant grade hydrazine (MPH) in AF-E-332 elastomer leaching tests. Results for silicon in MPH were comparable to those reported in the literature for other studies.

  5. Determination of a mutational spectrum

    DOEpatents

    Thilly, William G.; Keohavong, Phouthone

    1991-01-01

    A method of resolving (physically separating) mutant DNA from nonmutant DNA and a method of defining or establishing a mutational spectrum or profile of alterations present in nucleic acid sequences from a sample to be analyzed, such as a tissue or body fluid. The present method is based on the fact that it is possible, through the use of DGGE, to separate nucleic acid sequences which differ by only a single base change and on the ability to detect the separate mutant molecules. The present invention, in another aspect, relates to a method for determining a mutational spectrum in a DNA sequence of interest present in a population of cells. The method of the present invention is useful as a diagnostic or analytical tool in forensic science in assessing environmental and/or occupational exposures to potentially genetically toxic materials (also referred to as potential mutagens); in biotechnology, particularly in the study of the relationship between the amino acid sequence of enzymes and other biologically-active proteins or protein-containing substances and their respective functions; and in determining the effects of drugs, cosmetics and other chemicals for which toxicity data must be obtained.

  6. 78 FR 48703 - Proposed Flood Hazard Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-09

    ... SECURITY Federal Emergency Management Agency Proposed Flood Hazard Determinations AGENCY: Federal Emergency... Register a proposed flood hazard determination notice that contained an erroneous table. This notice.... The table provided here represents the proposed flood hazard determinations and communities...

  7. Residual analysis in the determination of factors affecting the estimates of body heat storage in clothed subjects.

    PubMed

    Aoyagi, Y; McLellan, T M; Shephard, R J

    1996-01-01

    Body heat storage can be estimated by calorimetry (from heat gains and losses) or by thermometry [from changes (delta) in mean body temperature (T b) calculated as a weighted combination of rectal (Tre) and mean skin temperatures (T sk)]. If an invariant weighting factor of Tre and T sk were to be used (for instance, delta T b = 0.8.delta Tre + 0.2 delta T sk under hot conditions), body heat storage could be over- or underestimated substantially relative to calorimetry, depending on whether the subject was wearing light or protective clothing. This study investigated whether discrepancies between calorimetry and thermometry arise from methodological errors in the calorimetric estimate of heat storage, from inappropriate weightings in the thermometric estimate, or from both. Residuals of calorimetry versus thermometric estimates were plotted against individual variables in the standard heat balance equation, applying various weighting factors to Tre and T sk. Whether light or protective clothing was worn, the calorimetric approach generally gave appropriate estimates of heat exchange components and thus heat storage. One exception was in estimating latent heat loss from sweat evaporation. If sweat evaporation exceeded 650 g.h-1 when wearing normal clothing, evaporative heat loss was overestimated and thus body heat storage was underestimated. Nevertheless, if data beyond this ceiling were excluded from the analyses, the standard 4:1 weighting matched calorimetric heat storage estimates quite well. When wearing protective clothing, the same 4:1 weighting approximated calorimetric heat storage with errors of less than approximately 10%, but only if environmental conditions allowed a subject to exercise for more than 90 min. The best thermometric estimates of heat storage were provided by using two sets of relative weightings, based upon the individual's metabolic heat production (M in kilojoules per meter squared per hour): (4 - [(M - x).x-1].2): 1 for an initial

  8. Chandra Independently Determines Hubble Constant

    NASA Astrophysics Data System (ADS)

    2006-08-01

    A critically important number that specifies the expansion rate of the Universe, the so-called Hubble constant, has been independently determined using NASA's Chandra X-ray Observatory. This new value matches recent measurements using other methods and extends their validity to greater distances, thus allowing astronomers to probe earlier epochs in the evolution of the Universe. "The reason this result is so significant is that we need the Hubble constant to tell us the size of the Universe, its age, and how much matter it contains," said Max Bonamente from the University of Alabama in Huntsville and NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala., lead author on the paper describing the results. "Astronomers absolutely need to trust this number because we use it for countless calculations." Illustration of Sunyaev-Zeldovich Effect Illustration of Sunyaev-Zeldovich Effect The Hubble constant is calculated by measuring the speed at which objects are moving away from us and dividing by their distance. Most of the previous attempts to determine the Hubble constant have involved using a multi-step, or distance ladder, approach in which the distance to nearby galaxies is used as the basis for determining greater distances. The most common approach has been to use a well-studied type of pulsating star known as a Cepheid variable, in conjunction with more distant supernovae to trace distances across the Universe. Scientists using this method and observations from the Hubble Space Telescope were able to measure the Hubble constant to within 10%. However, only independent checks would give them the confidence they desired, considering that much of our understanding of the Universe hangs in the balance. Chandra X-ray Image of MACS J1149.5+223 Chandra X-ray Image of MACS J1149.5+223 By combining X-ray data from Chandra with radio observations of galaxy clusters, the team determined the distances to 38 galaxy clusters ranging from 1.4 billion to 9.3 billion

  9. 45 CFR 150.219 - Final determination.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ENFORCEMENT IN GROUP AND INDIVIDUAL INSURANCE MARKETS CMS Enforcement Processes for Determining Whether States... the State a written notice of its final determination. The notice includes the following:...

  10. Mars Science Laboratory Orbit Determination

    NASA Technical Reports Server (NTRS)

    Kruizinga, Gerhard; Gustafson, Eric; Jefferson, David; Martin-Mur, Tomas; Mottinger, Neil; Pelletier, Fred; Ryne, Mark; Thompson, Paul

    2012-01-01

    Mars Science Laboratory (MSL) Orbit Determination (OD) met all requirements with considerable margin, MSL OD team developed spin signature removal tool and successfully used the tool during cruise, A novel approach was used for the MSL solar radiation pressure model and resulted in a very accurate model during the approach phase, The change in velocity for Attitude Control System (ACS) turns was successfully calibrated and with appropriate scale factor resulted in improved change in velocity prediction for future turns, All Trajectory Correction Maneuvers were successfully reconstructed and execution errors were well below the assumed pre-fight execution errors, The official OD solutions were statistically consistent throughout cruise and for OD solutions with different arc lengths as well, Only EPU-1 was sent to MSL. All other Entry Parameter Updates were waived, EPU-1 solution was only 200 m separated from final trajectory reconstruction in the B-plane

  11. Attitude Determination Improvements for GOES

    NASA Technical Reports Server (NTRS)

    Crassidis, John L.; Markley, F. Landis; Kyle, Arthur M.; Kull, Kathie

    1996-01-01

    In this paper, a summary of the basic simulation parameters and results of a new study for the Geostationary Operational Environmental Satellite (GOES) is shown. The study for GOES involves the simulation of minor modifications to the current spacecraft, so that the relative performance of these modifications can be analyzed. The first modification studies requires the placement of a baseline inertial reference unit, such as the Dry Rotor Inertial Reference Unit or the Hemispherical Resonator Gyro onto the spacecraft. The imager/sounder assembly is currently used to obtain landmark and/or star observations in order to compensate for spacecraft motion and external disturbances through ground processing. The study uses the imager/sounder assembly as another attitude sensor for on-board attitude determination. Also the addition of star trackers is used to provide precise attitude knowledge.

  12. Social determinants and osteoarthritis outcomes

    PubMed Central

    Luong, My-Linh N; Cleveland, Rebecca J; Nyrop, Kirsten A; Callahan, Leigh F

    2012-01-01

    Osteoarthritis (OA) is one of the most frequently occurring musculoskeletal diseases, posing a significant public health problem due to its impact on pain and disability. Traditional risk factors fail to account for all of the risk observed for OA outcomes. In recent years, our view of disease causation has broadened to include health risks that are created by an individual’s socioeconomic circumstances. Early research into social determinants has focused on social position and explored factors related to the individual such as education, income and occupation. Results from these investigations suggest that low education attainment and nonprofessional occupation are associated with poorer arthritis outcomes. More recently, research has expanded to examine how one’s neighborhood socioeconomic environment may be relevant to OA outcomes. This narrative review proposes a framework to help guide our understanding of how social context may interact with pathophysiological processes and individual-level variables to influence health outcomes in those living with OA. PMID:23243459

  13. GRO attitude control and determination

    NASA Technical Reports Server (NTRS)

    Jerkovsky, W.; Keranen, L.; Koehler, F.; Tung, F.; Ward, B.

    1986-01-01

    Design features of the attitude control and determination (ACAD) system for the Gamma Ray Observatory (GRO) that will eventually be launched on the Shuttle are described. A tabulation of the ACAD system components is provided and the various standby and normal pointing operational modes of the system are summarized. The system software and sensors will maintain a quaternion model of the GRO attitude on the bases of kinematic equations and inertial data. The software is standardized and has previously been used on the Solar Maximum Mission and Landsat-D. Details of the processing components, redundant electronics for sensor processing, data handling and actuator control are outlined and illustrated with block diagrams. Tests applied to validate the ACAD design are outlined, as are ground support which will be implemented once the GRO is launched.

  14. Determination of Human Hemoglobin Derivatives.

    PubMed

    Attia, Atef M M; Ibrahim, Fatma A A; Abd El-Latif, Noha A; Aziz, Samir W; Abdelmottaleb Moussa, Sherif A; Elalfy, Mohsen S

    2015-01-01

    The levels of the inactive hemoglobin (Hb) pigments [such as methemoglobin (metHb), carboxyhemoglobin (HbCO) and sulfohemoglobin (SHb)] and the active Hb [in the oxyhemoglobin (oxyHb) form] as well as the blood Hb concentration in healthy non pregnant female volunteers were determined using a newly developed multi-component spectrophotometric method. The results of this method revealed values of SHb% in the range (0.0727-0.370%), metHb% (0.43-1.0%), HbCO% (0.4-1.52%) and oxyHb% (97.06-98.62%). Furthermore, the results of this method revealed values of blood Hb concentration in the range (12.608-15.777 g/dL). The method is highly sensitive, accurate and reproducible.

  15. Prospective errors determine motor learning

    PubMed Central

    Takiyama, Ken; Hirashima, Masaya; Nozaki, Daichi

    2015-01-01

    Diverse features of motor learning have been reported by numerous studies, but no single theoretical framework concurrently accounts for these features. Here, we propose a model for motor learning to explain these features in a unified way by extending a motor primitive framework. The model assumes that the recruitment pattern of motor primitives is determined by the predicted movement error of an upcoming movement (prospective error). To validate this idea, we perform a behavioural experiment to examine the model’s novel prediction: after experiencing an environment in which the movement error is more easily predictable, subsequent motor learning should become faster. The experimental results support our prediction, suggesting that the prospective error might be encoded in the motor primitives. Furthermore, we demonstrate that this model has a strong explanatory power to reproduce a wide variety of motor-learning-related phenomena that have been separately explained by different computational models. PMID:25635628

  16. Detecting determinism from point processes

    NASA Astrophysics Data System (ADS)

    Andrzejak, Ralph G.; Mormann, Florian; Kreuz, Thomas

    2014-12-01

    The detection of a nonrandom structure from experimental data can be crucial for the classification, understanding, and interpretation of the generating process. We here introduce a rank-based nonlinear predictability score to detect determinism from point process data. Thanks to its modular nature, this approach can be adapted to whatever signature in the data one considers indicative of deterministic structure. After validating our approach using point process signals from deterministic and stochastic model dynamics, we show an application to neuronal spike trains recorded in the brain of an epilepsy patient. While we illustrate our approach in the context of temporal point processes, it can be readily applied to spatial point processes as well.

  17. Determinants of Mammalian Nucleolar Architecture

    PubMed Central

    Farley, Katherine I.; Surovtseva, Yulia; Merkel, Janie; Baserga, Susan J.

    2015-01-01

    The nucleolus is responsible for the production of ribosomes, essential machines which synthesize all proteins needed by the cell. The structure of human nucleoli is highly dynamic and is directly related to its functions in ribosome biogenesis. Despite the importance of this organelle, the intricate relationship between nucleolar structure and function remains largely unexplored. How do cells control nucleolar formation and function? What are the minimal requirements for making a functional nucleolus? Here we review what is currently known regarding mammalian nucleolar formation at nucleolar organizer regions (NORs), which can be studied by observing the dissolution and reformation of the nucleolus during each cell division. Additionally, the nucleolus can be examined by analyzing how alterations in nucleolar function manifest in differences in nucleolar architecture. Furthermore, changes in nucleolar structure and function are correlated with cancer, highlighting the importance of studying the determinants of nucleolar formation. PMID:25670395

  18. Crystal structure determination of Efavirenz

    SciTech Connect

    Popeneciu, Horea Dumitru, Ristoiu; Tripon, Carmen Borodi, Gheorghe Pop, Mihaela Maria

    2015-12-23

    Needle-shaped single crystals of the title compound, C{sub 14}H{sub 9}ClF{sub 3}NO{sub 2}, were obtained from a co-crystallization experiment of Efavirenz with maleic acid in a (1:1) ratio, using methanol as solvent. Crystal structure determination at room temperature revealed a significant anisotropy of the lattice expansion compared to the previously reported low-temperature structure. In both low- and room temperature structures the cyclopropylethynyl fragment in one of the asymmetric unit molecules is disordered. While at low-temperature only one C atom exhibits positional disorder, at room temperature the disorder is present for two C atoms of the cyclopropane ring.

  19. Seasat. Volume 4: Attitude determination

    NASA Technical Reports Server (NTRS)

    Treder, A. J.

    1980-01-01

    The Seasat project was a feasibility demonstration of the use of orbital remote sensing for global ocean observation. The satellite was launched in June 1978 and was operated successfully until October 1978. A massive electrical failure occurred in the power system, terminating the mission prematurely. The actual implementation of the Seasat Attitude Determination system and the contents of the attitude data files generated by that system are documented. The deviations from plan caused by the anomalous Sun interference with horizon sensors, inflight calibration of Sun sensor head 2 alignment and horizon sensor biomass, estimation of yaw interpolation parameters, Sun and horizon sensor error sources, and yaw interpolation accuracy are included. Examples are given of flight attitude data from all modes of the Orbital Attitude Control System, of the ground processing effects on attitude data, and of cold cloud effects on pitch, and roll data.

  20. Crystal face temperature determination means

    DOEpatents

    Nason, Donald O.; Burger, Arnold

    1994-01-01

    An optically transparent furnace (10) having a detection apparatus (29) with a pedestal (12) enclosed in an evacuated ampule (16) for growing a crystal (14) thereon. Temperature differential is provided by a source heater (20), a base heater (24) and a cold finger (26) such that material migrates from a polycrystalline source material (18) to grow the crystal (14). A quartz halogen lamp (32) projects a collimated beam (30) onto the crystal (14) and a reflected beam (34) is analyzed by a double monochromator and photomultiplier detection spectrometer (40) and the detected peak position (48) in the reflected energy spectrum (44) of the reflected beam (34) is interpreted to determine surface temperature of the crystal (14).

  1. Gravity Probe B orbit determination

    NASA Astrophysics Data System (ADS)

    Shestople, P.; Ndili, A.; Hanuschak, G.; Parkinson, B. W.; Small, H.

    2015-11-01

    The Gravity Probe B (GP-B) satellite was equipped with a pair of redundant Global Positioning System (GPS) receivers used to provide navigation solutions for real-time and post-processed orbit determination (OD), as well as to establish the relation between vehicle time and coordinated universal time. The receivers performed better than the real-time position requirement of 100 m rms per axis. Post-processed solutions indicated an rms position error of 2.5 m and an rms velocity error of 2.2 mm s-1. Satellite laser ranging measurements provided independent verification of the GPS-derived GP-B orbit. We discuss the modifications and performance of the Trimble Advance Navigation System Vector III GPS receivers. We describe the GP-B precision orbit and detail the OD methodology, including ephemeris errors and the laser ranging measurements.

  2. Experimental Determination of Ramsey Numbers

    NASA Astrophysics Data System (ADS)

    Bian, Zhengbing; Chudak, Fabian; Macready, William G.; Clark, Lane; Gaitan, Frank

    2013-09-01

    Ramsey theory is a highly active research area in mathematics that studies the emergence of order in large disordered structures. Ramsey numbers mark the threshold at which order first appears and are extremely difficult to calculate due to their explosive rate of growth. Recently, an algorithm that can be implemented using adiabatic quantum evolution has been proposed that calculates the two-color Ramsey numbers R(m,n). Here we present results of an experimental implementation of this algorithm and show that it correctly determines the Ramsey numbers R(3,3) and R(m,2) for 4≤m≤8. The R(8,2) computation used 84 qubits of which 28 were computational qubits. This computation is the largest experimental implementation of a scientifically meaningful adiabatic evolution algorithm that has been done to date.

  3. Experimental determination of Ramsey numbers.

    PubMed

    Bian, Zhengbing; Chudak, Fabian; Macready, William G; Clark, Lane; Gaitan, Frank

    2013-09-27

    Ramsey theory is a highly active research area in mathematics that studies the emergence of order in large disordered structures. Ramsey numbers mark the threshold at which order first appears and are extremely difficult to calculate due to their explosive rate of growth. Recently, an algorithm that can be implemented using adiabatic quantum evolution has been proposed that calculates the two-color Ramsey numbers R(m,n). Here we present results of an experimental implementation of this algorithm and show that it correctly determines the Ramsey numbers R(3,3) and R(m,2) for 4≤m≤8. The R(8,2) computation used 84 qubits of which 28 were computational qubits. This computation is the largest experimental implementation of a scientifically meaningful adiabatic evolution algorithm that has been done to date.

  4. Novel gene complex structure determination

    SciTech Connect

    Gatewood, J.M.

    1997-08-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LORD) project at the Los Alamos National Laboratory. `Operative` chromatin containing exclusively the minor hasten variants was successfully isolated. Linker hasten H1 is quantitatively missing from operative chromatin. One of the aims of this proposal was to determine the proteins responsible for stabilizing operative chromatin. This chromatin is stabilized by microtubule proteins tar and tubulin. Another goal of this project was the structural characterization of operate chromatin nucleosomes. Using solution scattering, nucleosomes containing the minor variants were shown to be structurally distinct from major variant containing nucleosomes. The unusual structure and stabilization of operative chromatin by microtubule proteins provides a possible mechanism for direct interaction of transcription machinery with specific chromatin domains.

  5. Structural determinants of glomerular permeability.

    PubMed

    Deen, W M; Lazzara, M J; Myers, B D

    2001-10-01

    Recent progress in relating the functional properties of the glomerular capillary wall to its unique structure is reviewed. The fenestrated endothelium, glomerular basement membrane (GBM), and epithelial filtration slits form a series arrangement in which the flow diverges as it enters the GBM from the fenestrae and converges again at the filtration slits. A hydrodynamic model that combines morphometric findings with water flow data in isolated GBM has predicted overall hydraulic permeabilities that are consistent with measurements in vivo. The resistance of the GBM to water flow, which accounts for roughly half that of the capillary wall, is strongly dependent on the extent to which the GBM surfaces are blocked by cells. The spatial frequency of filtration slits is predicted to be a very important determinant of the overall hydraulic permeability, in keeping with observations in several glomerular diseases in humans. Whereas the hydraulic resistances of the cell layers and GBM are additive, the overall sieving coefficient for a macromolecule (its concentration in Bowman's space divided by that in plasma) is the product of the sieving coefficients for the individual layers. Models for macromolecule filtration reveal that the individual sieving coefficients are influenced by one another and by the filtrate velocity, requiring great care in extrapolating in vitro observations to the living animal. The size selectivity of the glomerular capillary has been shown to be determined largely by the cellular layers, rather than the GBM. Controversial findings concerning glomerular charge selectivity are reviewed, and it is concluded that there is good evidence for a role of charge in restricting the transmural movement of albumin. Also discussed is an effect of albumin that has received little attention, namely, its tendency to increase the sieving coefficients of test macromolecules via steric interactions. Among the unresolved issues are the specific contributions of the

  6. Crystallization kinetics of poly-(lactic acid) with and without talc: Optical microscopy and calorimetric analysis

    NASA Astrophysics Data System (ADS)

    Refaa, Z.; Boutaous, M.; Rousset, F.; Fulchiron, R.; Zinet, M.; Xin, S.; Bourgin, P.

    2014-05-01

    Poly-(lactic acid) or PLA is a biodegradable polymer synthesized from renewable resources. Recently, the discovery of new polymerization routes has allowed increasing the produced volumes. As a consequence, PLA is becoming of great interest for reducing the dependence on petroleum-based plastics. Because of its interesting mechanical properties, PLA is seen as a potential substitute for some usual polymers. However, its relatively slow crystallization kinetics can be a disadvantage with regard to industrial applications. The crystallization kinetics of PLA can be enhanced by adding nucleating agents, which also influences on crystalline morphology and rheological behavior. In the present work, the isothermal quiescent crystallization kinetics of both neat PLA and PLA/talc composite (5 wt% talc) are investigated. The effects of talc on the overall crystallization kinetics and on the crystalline morphology are analyzed using both optical microscopy measurements and thermal analysis by differential scanning calorimetry.

  7. Isothermal titration calorimetric analysis of the interaction between cationic lipids and plasmid DNA.

    PubMed

    Lobo, B A; Davis, A; Koe, G; Smith, J G; Middaugh, C R

    2001-02-01

    The effects of buffer and ionic strength upon the enthalpy of binding between plasmid DNA and a variety of cationic lipids used to enhance cellular transfection were studied using isothermal titration calorimetry at 25.0 degrees C and pH 7.4. The cationic lipids DOTAP (1,2-dioleoyl-3-trimethyl ammonium propane), DDAB (dimethyl dioctadecyl ammonium bromide), DOTAP:cholesterol (1:1), and DDAB:cholesterol (1:1) bound endothermally to plasmid DNA with a negligible proton exchange with buffer. In contrast, DOTAP: DOPE (L-alpha-dioleoyl phosphatidyl ethanolamine) (1:1) and DDAB:DOPE (1:1) liposomes displayed a negative enthalpy and a significant uptake of protons upon binding to plasmid DNA at neutral pH. These findings are most easily explained by a change in the apparent pKa of the amino group of DOPE upon binding. Complexes formed by reverse addition methods (DNA into lipid) produced different thermograms, sizes, zeta potentials, and aggregation behavior, suggesting that structurally different complexes were formed in each titration direction. Titrations performed in both directions in the presence of increasing ionic strength revealed a progressive decrease in the heat of binding and an increase in the lipid to DNA charge ratio at which aggregation occurred. The unfavorable binding enthalpy for the cationic lipids alone and with cholesterol implies an entropy-driven interaction, while the negative enthalpies observed with DOPE-containing lipid mixtures suggest an additional contribution from changes in protonation of DOPE.

  8. Feasibility of large-scale calorimetric efficiency measurement for wind turbine generator drivetrains

    NASA Astrophysics Data System (ADS)

    Pagitsch, Michael; Jacobs, Georg; Schelenz, Ralf; Bosse, Dennis; Liewen, Christian; Reisch, Sebastian; Deicke, Matthias

    2016-09-01

    In the course of the global energy turnaround, the importance of wind energy is increasing continuously. For making wind energy more competitive with fossil energy, reducing the costs is an important measure. One way to reach this goal is to improve the efficiency. As the major potentials have already been exploited, improvements in the efficiency are made in small steps. One of the main preconditions for enabling these development activities is the sufficiently accurate measurement of the efficiency. This paper presents a method for measuring the efficiency of geared wind turbine generator drivetrains with errors below 0.5% by directly quantifying the power losses. The presented method is novel for wind turbines in the multi- MW-class.

  9. 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

  10. 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...

  11. Calorimetric study on the decomposition of hydroxylamine in the presence of transition metals.

    PubMed

    Kumasaki, Mieko

    2004-11-11

    Hydroxylamine (HA), hydroxylamine chloride (HAC1), and hydroxylamine nitrate (HAN) were each mixed with aqueous solutions of Cr3+, Cr6+, Mn7+, Co2+, Co3+, and Cu2+, and their heat flow profiles were monitored by a small-scaled reaction calorimeter, SuperCRC. These mixing tests demonstrated that HA was less reactive than HACl and HAN with Mn7+ and Cr6+. Their UV-vis spectra confirmed that the substrates reacted when Mn7+ and Cr6+ were reduced. HA was more reactive with Cu2+ than HAC1 and HAN and exhibited the highest reactivity among the three substrates with regard to metals in the intermediate oxidation states: Cr3+, Co3+, and Co2+. During the reaction of HA and Co3+, an induction period was observed. All exothermic reactions were accompanied by precipitation or a change in the UV-vis spectra.

  12. Calorimetric Studies on Thermal Properties of Nano-Cryoprotectant Solutions during Vitrification.

    PubMed

    Xu, H F; Hao, B T; Liu, L J; Tang, L L; Liu, B L

      BACKGROUND: Vitrification, the ice-free cryopreservation, develops rapidly and can become an ideal method for long-term preservation of cells and tissues. But up to now it is not practical for samples with large size because of the ultra-rapid cooling rate required. It has been reported that nanoparticles improve heat conductivity of solutions.

  13. A fast timing calorimetric layer using micro-channel plates in ionisation mode

    NASA Astrophysics Data System (ADS)

    Barnyakov, A.; Barnyakov, M.; Brianza, L.; Cavallari, F.; Ciriolo, V.; Del Re, D.; Gelli, S.; Ghezzi, A.; Gotti, C.; Martelli, A.; Marzocchi, B.; Meridiani, P.; Organtini, G.; Pigazzini, S.; Paramatti, R.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Tabarelli De Fatis, T.

    2017-03-01

    Future high rate hadron colliders are expected to have hundreds of concurrent proton-proton interactions in the same bunch crossing, deteriorating the energy resolution and identification capabilities of calorimeters. The possibility to distinguish neutral particles coming from different interaction vertices is being pursued as a tool to reduce pile-up contamination in calorimeters, and restore optimal performance. A time of flight resolution of the order of 20 ps will be able to reduce neutral particles pile-up contamination at the calorimeter level by about one order of magnitude, restoring pile-up conditions similar to what is routinely sustained in the current run of the LHC . Micro-channel plates (MCP) can be used in PMT configuration as fast charged particles detector (resolution of better then 30 ps can be achieved with commercial devices). However they are not particularly radiation tolerant, mostly due to the ion feedback on the photocathode. The possibility of using micro-channel plates without a photocathode (i-MCP) has been studied in several test beams. Different MCP geometries are compared with the goal to identify the optimal configuration. Efficiency of more than 70% with a time resolution of better than 40 ps are achieved for single charged particles, leading to an efficiency close to 100% for EM shower after few radiation lengths. This opens the possibility to use i-MCPs as a timing layer in a sampling calorimeter or to use it in a pre-shower device independent from the calorimeter technology. Preliminary results on the radiation hardness of the i-MCP configuration will be also presented.

  14. Thermodynamics of translesion synthesis across a major DNA adduct of antitumor oxaliplatin: differential scanning calorimetric study.

    PubMed

    Florian, Jakub; Brabec, Viktor

    2012-02-06

    Differential scanning calorimetry (DSC) was used to measure the thermodynamic changes associated with translesion synthesis across major lesion induced in DNA by antitumor oxaliplatin [1,2-d(GG) intrastrand cross-link]. Insertion of matched nucleotides dC at the primer terminus (across unique 3'- or 5'-dG in the unplatinated template) and subsequent extensions resulted in an incremental increase in thermodynamic parameters. In contrast, incorporation of dC opposite either platinated dG in the intrastrand cross-link formed in the template strand and subsequent extensions by one nucleotide resulted only in little changes in thermodynamics. A similar thermodynamic delay was observed for a control template primer containing a dG:dT mismatch across 3'- or 5'-dG in the template and subsequent Watson-Crick primer extensions. The thermodynamic scarcity generated by either the lesion or mismatches was not localized but extended to the 5'-downstream sites, which may be connected with the phenomenon termed "short-term memory" of replication errors retained by some DNA polymerases responding to DNA damages or mismatches. Interestingly, formation of the 1,2-d(GG) intrastrand cross-link of oxaliplatin altered the overall DSC profiles of the dG:dT mismatch template/primers only in a very small extent. While addition of matched nucleotide dC across either dG in the template strand was thermodynamically favored over the presence of a mismatched dT (ΔΔG(0)(310) was 7.6 or 6.8 kJ mol(-1), ΔΔH was 14 or 49 kJ mol(-1)), no such thermodynamic advantage was observed with the 1,2-d(GG) intrastrand cross-link of oxaliplatin at these positions (ΔΔG(0)(310) was 2.8 or -0.3 kJ mol(-1), ΔΔH was 4 or 9 kJ mol(-1)). The equilibrium thermodynamic data also provide insight into the processes associated with misincorporation of incorrect nucleotides during replication bypass across major cross-links of antitumor oxaliplatin. On the other hand, besides thermodynamic effects also kinetic factors play an important role in the processing of the cross-links of antitumor platinum drugs. The impact of the two effects in overall processing DNA adducts by a particular DNA polymerase will depend on its nature.

  15. 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.

  16. 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.

  17. Effect of high-pressure on calorimetric, rheological and dielectric properties of selected starch dispersions.

    PubMed

    Ahmed, Jasim; Singh, Ajaypal; Ramaswamy, H S; Pandey, Pramod K; Raghavan, G S V

    2014-03-15

    Effects of high-pressure (HP) treatment on the rheological, thermal and dielectric properties of the four selected starch dispersions (two modified starches, one native and one resistant) were evaluated. Differential scanning calorimetry (DSC) and oscillatory rheometry were employed to assess the extent of starch gelatinization and the developed gel rigidity (G') of starch gels after HP treatment. It was observed that starch dispersions gelatinized completely at 500 MPa with a 30-min holding time. The HP-treated starch samples exhibited predominantly solid-like (G'>G") behavior except for the resistant starch. Pressure-induced gel rigidity differed significantly among starch samples. The G' of starch gels increased with the pressure (400-600 MPa) in the studied frequency range (0.1-10 Hz) except for the native starch where a marginal decrease was recorded at similar condition. The holding time (15-30 min) and concentration (20-25% w/w) significantly attributed towards gel rigidity of starch samples. Measurement of dielectric properties of HP-treated samples over the frequency range 450-4450 MHz indicated differences in the dielectric constant (ɛ'), loss factor (ɛ") and penetration depth among starch gels. Pressure did not show any effect on dielectric property of the resistant starch sample. Power penetration depth decreased significantly with frequency and with the pressure.

  18. Micelles of Benzethonium Chloride undergoes spherical to cylindrical shape transformation: An intrinsic fluorescence and calorimetric approach

    NASA Astrophysics Data System (ADS)

    Karumbamkandathil, Arshad; Ghosh, Subhadip; Anand, Uttam; Saha, Prithwidip; Mukherjee, Madhumita; Mukherjee, Saptarshi

    2014-02-01

    We report for the first time that Benzethonium Chloride (BTC) in aqueous solution actually gets transformed from a spherical to a cylindrical micelle. We have made rational use of the intrinsic fluorescence of BTC, rendered by the two phenyl rings in estimating its structural modifications as this methodology is devoid of any external perturbations. Our approach has been well-supported by Isothermal Titration Calorimetry (ITC). Using the ITC analyses and theoretical calculations, we have conclusively proved that the shape of the micelles change from spherical (at its Critical Micelle Concentration) to cylindrical because the micelles grow in a uni-axial manner.

  19. 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.

  20. Comparative Analysis of Healthy and Tumoral Human Bone Tissues by Spectrometric and Calorimetric Techniques

    NASA Astrophysics Data System (ADS)

    Acosta-Romero, A.; Peña-Rico, M. A.; Heredia, A.; Lozano, L. F.; Ruvalcaba, J. L.; Bucio, L.; Belío-Reyes, I. A.; Mondragón-Galicia, G.

    2002-08-01

    Hyaline collagen can be present in bone tissue in such a manner that no fibroblast cells are able to be seen. Hystologicaly, hyaline collagen is difficult to distinguish from osteoid. The osteoid in the mineralization process (the accumulating hydroxyapatite carbonate, HAP, crystals) is made by the osteoblasts, and its looking is much like hyaline collagen. There are illnesses that could be useful to distinguish microscopically between hyaline collagen and osteoid. From the scope of the mineralization process, here we present the physical and chemical features that characterize hyaline collagen and osteoid employing differential scanning calorimetry, low vacuum scanning electron microscopy, FT Infrared spectroscopy and chemical analysis by Proton induced X-ray emission, PIXE. The results show that hyaline collagen has more thermal stability than osteoid tissue. The last could be explained considering the presence of nanometric apatite crystallites (acting as fracture centres) in the osteoid tissue having those apatite crystallites the effect in turn of diminish the thermal stability.