Sample records for xvi calorimetric determination

  1. A calorimetric method to determine water activity

    Microsoft Academic Search

    2011-01-01

    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

  2. Calorimetric determination of the enthalpy of formation for pyrophyllite

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

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

  3. Calorimetric determination of H + \\/M + (M = Li, Cs) ion exchange in ? -titanium hydrogen phosphate

    Microsoft Academic Search

    Eliana González; Camino Trobajo; Ricardo Llavona; José R. García; Julio Rodríguez

    1989-01-01

    H+\\/M+ (M = Li, Cs) ion exchange in?-titanium phosphate (?-TIP) at 25°C and under static conditions has been studied. Titration and hydrolysis curves and the exchange isotherms were determined. The substitution was followed by X-ray diffraction. Direct calorimetric measurements were carried out at different degrees of conversion and the variation of the exchange enthalpy was obtained. The shape of the

  4. 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.

  5. Calorimetric determination of the thermodynamic behavior of reversible liquid-phase reactions for use in energy storage

    SciTech Connect

    Thompson, P.F.

    1983-01-01

    A new calorimetric method of determining equilibrium mole fractions of labile species that participate in reversible, liquid-phase reactions has been developed. This technique relies on the fact that a reactant-solvent mixture of just the right composition will shift the equilibrium neither to the left nor to the right and thus will neither absorb nor generate heat when injected into an equilibrium mixture. Using the open-system energy balance, initial mole fraction valves for each constituent, and the experimentally determined composition of the reactant-solvent mixture which causes no reaction, the equilibrium mole fraction of each constituent can be determined.

  6. 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.

  7. 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. PMID:25383921

  8. 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 ? 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.

  9. A calorimetric method for determining the absorption for visible and near-infrared radiation of surfaces

    Microsoft Academic Search

    J. L. Verster; M. Sikkens; F. Bosscher

    1978-01-01

    The method consists of determining the power P1 absorbed by a surface from a beam of visible or near-infrared radiation, and of subsequently determining the power P2 absorbed by a black surface from the same radiation. The wavelength lambda of the radiation is determined by one of a set of bandpass filters. The temperatures are measured by means of thermistors.

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  11. Calorimetric Gas Sensors.

    NASA Astrophysics Data System (ADS)

    Zanini, Margherita; Visser, J. H.; Nietering, K. E.; McBride, J. R.; Logothetis, E. M.

    1998-03-01

    Calorimetric gas sensors measure the concentration of combustibles species by detecting the temperature rise resulting from the oxidation process on a catalytic element. These devices are widely used to monitor in air the concentration of flammable species close to their explosion limit. Recently, research and development efforts have been directed towards applying this technology to measure low concentrations of hydrocarbons in a gas mixture at elevated temperatures with little amount of excess oxygen. The presentation discusses the advantages of using batch-fabricated Si micromachined devices over larger ceramic-type calorimeters to achieve high sensitivity and a fast response time. The effects limiting the performance of these devices will also be explained.

  12. Prototype of calorimetric flow microsensor

    NASA Astrophysics Data System (ADS)

    Sazhin, Oleg

    2012-11-01

    An analytical model of calorimetric flow sensor has been developed. The results of the application of this model are utilized to develop a calorimetric flow microsensor with optimal functional characteristics. The technology to manufacture the microsensor is described. A prototype of the microsensor suitable to be used in the mass air flow meter has been designed. The basic characteristics of the microsensor are presented.

  13. The use of selective extraction chromatographic columns as an alternative to solvent extraction for the separation of uranium followed by the use of Arsenazo III as a calorimetric reagent for uranium determination

    SciTech Connect

    Miller, C.J.; Del Mastro, J.R.

    1994-10-01

    The use of U/TEVA{reg_sign} Spec columns as an alternative to solvent extraction for separation of uranium prior to its determination by various techniques (calorimetric, phosphorescence, and mass spectroscopy) was investigated. U/TEVA{reg_sign} Spec columns have several advantages over the widely used 4-methyl-2-pentanone solvent extraction method. Among the advantages are: (1) no hazardous liquid organic waste, that creates regulatory waste disposal problems, is generated; (2) a clean separation of U from Zr, F, and fission products is obtained; (3) the sample preparation time is reduced; and (4) the exposure of analysts to ionizing radiation is reduced because the entire procedure may be performed in a hot cell using remote operations. This study also investigated the use of Arsenazo III (1,8-dihydroxynapthalene-3,6-disulfonic acid-2,7-bis [<-azo-2>-phenylarsonic acid]) as a calorimetric reagent to determine uranium concentrations over a wide range in waste streams and product streams at the Idaho Chemical Processing Plant. Process and waste stream samples were passed through a U/TEVA{reg_sign} Spec column to selectively remove the uranium. The uranium bearing fraction is compatible with the pH range for color development with Arsenazo III. Arsenazo III may be added to the uranium fraction, at a 3:1 mole ratio (Arsenazo:Uranium) at the high end of the method (10 {mu}/mL). Arsenazo III forms a highly stable complex with uranium. Stability tests from this and other studies show that the colored complex of Arsenazo III with U(VI) forms within one minute and remains stable for several hours. The complex with U(VI) varies in color with pH. However, with excess reagent, the color is varying shades of purple. Since the samples were passed through a highly selective extraction chromatographic column prior to adding the calorimetric reagent, no interferences were observed.

  14. 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.

  15. Calorimetric gas sensor

    DOEpatents

    Ricco, Antonio J. (Albuquerque, NM); Hughes, Robert C. (Cedar Crest, NM); Smith, James H. (Albuquerque, NM); Moreno, Daniel J. (Albuquerque, NM); Manginell, Ronald P. (Albuquerque, NM); Senturia, Stephen D. (Brookline, MA); Huber, Robert J. (Bountiful, UT)

    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.

  16. 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–session, topics ranging from theoretical chemistry and molecular physics via fundamental problems in quantum theory to thermodynamics, nonlinear dynamics, soliton theory and finally cosmology, were examined and lively discussed. Nearly all the talks can also be viewed on the conference website. The majority of participants contributed to these Proceedings but some were unable to do so as their results were either previously submitted or published elsewhere. We refer to: · Quesne C 2013, J. Math. Phys. 54, 102102. · Spera M 2013, (Nankai Series in Pure, Applied Mathematics and Theoretical Physics): 11 Symmetries and Groups in Contemporary Physics: pp. 593–598 Proceedings of the XXIX International Colloquium on Group–Theoretical Methods in Physics Tianjin, China, 20 – 26 August 2012 (World Scientific, Singapore) · Snobl L and Winternitz P 2014, Classification and Identification of Lie Algebras, CRM Monograph Series 33 (Montreal) ISBN–10: 0–8218–4355–9, ISBN–13: 978–0–8218–4355–0 (http://www.ams.org/bookstore?fn=20&arg1=crmmseries&ikey=CRMM-33). Our personal thanks to Daniel and family! Endless support from the Schenk Family who, among other things, sponsored (yet again) the entire conference dinner (including wines and banquet hall) meant that some costs could be alleviated. We could therefore assist various colleagues from economically–weak countries, despite the lack of external funding. A financial deficit meant we would have had to forego the Conference Proceedings, published in previous years by IOP. After long deliberations, and with donations from Gerhard Berssenbrügge, Dr. Dr. Stephan Hauk and Dr. Volker Weisswange, this could be facilitated. We are very grateful to these private donors for their generous and wholehearted support. The staff of Collegium Mehrerau is also to be thanked for their hospitality. Finally, our sincere thanks to Yvette not only for her preparatory work and support during the conference, but also for her persistent interest and help in producing the Proceedings within a reasonable time. Dieter Schuc

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

  18. Calorimetric system and method

    DOEpatents

    Gschneidner, Jr., Karl A. (Ames, IA); Pecharsky, Vitalij K. (Ames, IA); Moorman, Jack O. (Boone, IA)

    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).

  19. 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.

  20. Radiation beam calorimetric power measurement system

    DOEpatents

    Baker, John (Livermore, CA); Collins, Leland F. (Pleasanton, CA); Kuklo, Thomas C. (Ripon, CA); Micali, James V. (Dublin, CA)

    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.

  1. EDITORIAL: XVI Brazilian Colloquium on Orbital Dynamics

    NASA Astrophysics Data System (ADS)

    de Melo, Cristiano F.; Macau, Elbert E. N.; Prado, Antonio B. A.; Hetem Jnr, Annibal

    2013-10-01

    The XVI Brazilian Colloquium on Orbital Dynamics was held from 26-30 November 2012, at the Biazi Grand Hotel, Serra Negra, São Paulo, Brazil. The Brazilian Colloquia on Orbital Dynamics are scientific events that occur bi-annually and are designed to develop those areas of research in celestial mechanics, orbital dynamics, planetary science, fundamental astronomy, aerospace engineering, and nonlinear systems and chaos. The meeting has been held for 30 years and it brings together researchers, professors and students from South American and also from other continents. Acknowledgements National Council for Scientific and Technological Development - CNPq Coordination for the Improvement of Higher Level - CAPES São Paulo Research Foundation - FAPESP

  2. 2007 Site environmental report xvi the environmental and Waste Management

    E-print Network

    2007 Site environmental report xvi the environmental and Waste Management services Division field Division radiological Control Division lead chapter authors environmental and waste management services contributors environmental and waste management services division Arland Carsten, Consultant Mark Davis George

  3. Calorimetric Insight into Coupling between Functionalized Primary Alkyl Halide and Vinylic Organocuprate Reagent: Experimental Determination of Reaction Enthalpies in the Synthesis of (R)-Ethyl 3-(tert-butyldimethylsilyloxy)hex-5-enoate - a Key Lactonized Statin Side Chain Precursor.

    PubMed

    Casar, Zdenko; Tramšek, Marko; Goršek, Andreja

    2010-03-01

    The first calorimetric study of coupling between organocuprate, derived from Grignard reagent (vinyl magnesium chloride), and primary alkyl halide (e.g. (S)-ethyl 3-(tert-butyldimethylsilyloxy)-4-iodobutanoate) has been conducted. This transformation is paramountly important for efficient preparation of (R)-ethyl 3-(tert-butyldimethylsilyloxy)hex-5-enoate - a key lactonized statin side chain precursor. The results obtained give thorough calorimetric insight into this complex low-temperature synthesis as well as a new understanding of the suggested reductive elimination of the final intermediates in the coupling reaction. Namely, the surprising unexpected spontaneous three-step exothermal event has been observed during controlled progressive heating of the mixture of the final intermediates to the room temperature. This phenomenon confirms that coupling between functionalized primary alkyl halide and vinylic organocuprate reagent is not a simple SN2 substitution reaction. The presented study provides among others the first reported values of reaction enthalpies and corresponding adiabatic temperature rises of reaction mixture for all exothermic events that occurred in the (R)-ethyl 3-(tert-butyldimethylsilyloxy)hex-5-enoate synthesis. The obtained results ensure consequential thermal process safety knowledge which can be incorporated into safe process scale-up as well as design of reactor system with sufficient cooling capacity for industrial production of (R)-ethyl 3-(tert-butyldimethylsilyloxy)hex-5-enoate. Moreover, the results provide a basic guidance for other organocuprate coupling reaction systems. PMID:24061657

  4. Thermal radiation from hot surfaces measured by optical and calorimetric methods

    NASA Astrophysics Data System (ADS)

    Oconnor, G. T.

    The radiative heat loss from a surface is determined by its total hemispherical emittance, which consequently plays an important role in aerospace and solar applications. This study compares emittances measured calorimetrically with values derived from near normal incidence spectral reflectance measurements. This optical derivation is based on a number of assumptions which limit the accuracy if not sufficiency fulfilled. These assumptions include sample specularity, a straybody character beyond the range of measurement, only small variations of emittance with temperature, and a perfectly smooth sample surface. The comparison of calorimetrically and optically derived emittance performed in this study not only quantifies the errors introduced by insufficient fulfillment of the assumptions but also identifies which assumption causes the dominant error. The calorimetric emissometer, constructed for this study and based on a heat flow sensor, was calibrated with aluminum and nickel thin films, resulting in good agreement with literature values.

  5. Measurement of the calorimetric energy scale in MINOS

    SciTech Connect

    Hartnell, Jeffrey J.; /Oxford U.

    2005-06-01

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

  6. Low temperature sugar-water equilibrium curve by a rapid calorimetric method

    Microsoft Academic Search

    V. Hoff; S CORRERA

    1995-01-01

    A simple rapid enthalpic method based upon a unique calorimetric measurement was developed and applied to sugar solutions at low temperatures to determine the amount of unfreezable water. The experimental results were in good agreement with those obtained by the usual freezing point depression method. The experimental data were also used to test the validity of several literature semi-empirical models

  7. Fast Electron Thermometry for Ultrasensitive Calorimetric Detection

    NASA Astrophysics Data System (ADS)

    Gasparinetti, S.; Viisanen, K. L.; Saira, O.-P.; Faivre, T.; Arzeo, M.; Meschke, M.; Pekola, J. P.

    2015-01-01

    We demonstrate radio-frequency thermometry on a micrometer-sized metallic island below 100 mK. Our device is based on a normal-metal-insulator-superconductor tunnel junction coupled to a resonator with transmission readout. In the first generation of the device, we achieve 90 ? K /?{Hz } noise-equivalent temperature with 10 MHz bandwidth. We measure the thermal relaxation time of the electron gas in the island, which we find to be of the order of 100 ? s . Such a calorimetric detector, upon optimization, can be seamlessly integrated into superconducting circuits, with immediate applications in quantum-thermodynamics experiments down to single quanta of energy.

  8. 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.

  9. Nanoclay modified polycarbonate blend nanocomposites: Calorimetric and mechanical properties

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  10. 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 molecular collisions and chemically reactive systems (papers by Toennies, Cavalli et al, Varandas, Nyman, Allan et al, Liu et al, Boxford et al); cooling and alignment of molecular systems (papers by Kumarappan et al, van de Meerakker et al); photon-matter interactions, spectroscopy and photodissociation (papers by Fárník and Buck, Golan et al, Borghesani et al, Coreno et al); theory of complex systems (papers by Villarreal et al, Bodo et al, Yurtsever and Calvo). The final contribution concerns the dynamics of systems of biological relevance (paper by Denicke et al). The paper by Toennies, one of the founding fathers of the MOLEC conference and winner of the MOLEC award in 1996, presents a comprehensive account of the experimental developments in the field of low energy collisions over the last 30 years, and provides a short outlook on how the most recent cooling and ultra cooling techniques (helium droplets and electro-magnetic laser traps) could open up new perspectives in the field of chemical reaction dynamics. Cavalli et al present a theoretical interpretation of overlapping resonances in the reactive cross section for the benchmark reaction F + H2?HF + H, explained by the formation of a short-lived state located in the transition state region and of a van der Waals metastable state in the exit valley. The subject of accurate ab initio calculations for potential energy surfaces is addressed by Varandas in a paper describing suitable modelling strategies to obtain intermolecular potentials at near spectroscopic resolution. In the following paper, Nyman gives an overview of how thermal rate constants for polyatomic chemical reactions can be calculated from first principles: the reaction H2 + CH3?CH4 + H is used as an example and theoretical results are compared with experimental ones. The `uncharted territory' of collision dynamics at the gas-liquid interface is explored in the pioneering contribution by Allan et al, in which experimental results on the reactivity of O atoms with long chain liquid hydrocarbons are interpreted with the aid of molecular dynamic

  11. Calorimetric studies of solid wastes, sewage sludge, wastewaters and their effects on soil biodegradation processes

    Microsoft Academic Search

    J. Dziejowski; I. Bia?obrzewski

    2011-01-01

    Calorimetric studies of solid wastes, sewage sludge, wastewaters and their environmental effects focus on three main research\\u000a areas. The first research area involves determination of selected thermal and physical parameters characterizing the above\\u000a substances, such as specific heat, thermal conductivity and others. The second area covers processes of total or gradual destruction\\u000a of the examined substances at a fixed composition

  12. Al–Ga–Zn Phase Diagram. Calorimetric study of the isobaric invariants

    Microsoft Academic Search

    E. Aragon; K. Jardet; P. Satre; A. Sebaoun

    2000-01-01

    The Al–Ga–Zn ternary phase diagram presents two isobaric invariant reactions: a eutectic at 231C and a metatectic at 1231C\\u000a [1–3]. Calorimetric measurements on the two isobaric invariant reactions have been carried out. First the Tammann method has\\u000a enabled us to determine the composition of their limits on five isopletic cross sections. Then, the compositions of the invariant\\u000a phases have been

  13. Calorimetric sensors for energy deposition measurements

    SciTech Connect

    Langenbrunner, J.; Cooper, R. [Bechtel Nevada, Los Alamos, NM (United States); Morgan, G. [Los Alamos National Lab., NM (United States)] [and others

    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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  15. 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

    ...XVI: Procedures for Handling Requests To File Subsequent Applications for Disability...procedures for handling your request to file a disability claim when you have a pending...XVI: Procedures for Handling Requests To File Subsequent Applications for...

  16. 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.

  17. On-device extraction of thermal thin-film properties in calorimetric flow sensors

    NASA Astrophysics Data System (ADS)

    Beigelbeck, Roman; Talic, Almir; Cerimovic, Samir; Kohl, Franz; Keplinger, Franz

    2011-06-01

    In diaphragm-based micromachined calorimetric flow sensors, the convective heat transfer through the test fluid competes with the spurious heat shunt induced by the thin-film diaphragm where the heater and the temperature sensors are embedded. Therefore, accurate knowledge of the thermal transport properties (thermal conductivity and diffusivity) and the emissivity of the diaphragm is mandatory for design, simulation, and optimization of such devices. However, these parameters can differ considerably from those stated for bulk material and they are typically dependent on the production process. Commonly used methods for their determination require the fabrication of custom specimens. In order to overcome this serious drawback, we developed a novel technique to extract the thermal thin-film properties directly from measurements carried out on calorimetric flow sensors. Here, the heat transfer frequency response from the heater to the thermistors is measured and compared to a theoretically obtained relationship arising from an extensive two-dimensional analytical model. This model covers the heat generation by the heater, the heat conduction in the diaphragm, the radiation loss at the diaphragm's surface, and the heat sink caused by the supporting silicon frame. In this contribution, we report in detail on the measurement setup, the theoretical model for the associated parameter extraction, and the results obtained from measurements on calorimetric flow sensors featuring dielectric thin-film diaphragms made of PECVD Si3N4.

  18. The CALorimetric Electron Telescope, CALET, Mission

    NASA Astrophysics Data System (ADS)

    Torii, Shoji

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

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

    Microsoft Academic Search

    Achim Krauss; Ralf-Peter Kapsch

    2007-01-01

    The relative uncertainty of the ionometric determination of the absorbed dose to water, Dw, in the reference dosimetry of high-energy photon beams is in the order of 1.5% and is dominated by the uncertainty of the calculated chamber- and energy-dependent correction factors kQ. In the present investigation, kQ values were determined experimentally in 5 cm × 5 cm and 10

  20. Planck 2013 results. XVI. Cosmological parameters

    E-print Network

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

    2014-01-01

    We present the first results based on Planck measurements of the CMB temperature and lensing-potential power spectra. The Planck spectra at high multipoles are extremely well described by the standard spatially-flat six-parameter LCDM cosmology. In this model Planck data determine the cosmological parameters to high precision. We find a low value of the Hubble constant, H0=67.3+/-1.2 km/s/Mpc and a high value of the matter density parameter, Omega_m=0.315+/-0.017 (+/-1 sigma errors) in excellent agreement with constraints from baryon acoustic oscillation (BAO) surveys. Including curvature, we find that the Universe is consistent with spatial flatness to percent-level precision using Planck CMB data alone. We present results from an analysis of extensions to the standard cosmology, using astrophysical data sets in addition to Planck and high-resolution CMB data. None of these models are favoured significantly over standard LCDM. The deviation of the scalar spectral index from unity is insensitive to the additi...

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

    NASA Astrophysics Data System (ADS)

    Krauss, Achim; Kapsch, Ralf-Peter

    2007-10-01

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

  2. TECHNICAL DESIGN NOTE A differential formulation of the T-History calorimetric method

    NASA Astrophysics Data System (ADS)

    Moreno-Alvarez, L.; Herrera, J. N.; Meneses-Fabian, C.

    2010-12-01

    We present a differential formulation of the T-History calorimetric method in order to achieve thermodynamic consistency with phase transitions theory and to include the important experimental effect of the speed of the thermal process in calorimetric calculations. To illustrate the applicability of the new formulation, we show some numerical results which give an acceptable description of calorimetric measures.

  3. A Calorimetric Method for Determination of Heat Capacity of Ceramics for Concentrated Solar Thermal Systems / Sken?još?s Kalorimetrijas Metode Siltumietilp?bas Noteikšanai Saules Kolektoru Keramik?

    NASA Astrophysics Data System (ADS)

    Kalna?s, 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 ??(?) measurements and calculations were performed at continuous scanning in the temperature range 20-800 °?. 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 ??(?) dependence was obtained for different ceramic materials. Rakst? izkl?st?ta izstr?d?t? metodika keramikas un emalju siltumietilp?bas noteikšanai p?c diferenci?l?s sken?još?s kalorimetrijas m?r?jumiem. Par?d?ta virkne trauc?jošo faktoru kalibr?šanas l?knes un m?r?jumu veikšanai, pied?v?tas metodes to samazin?šanai vai nov?ršanai, prec?z?ku rezult?tu ieguvei. Noteikta siltumietilp?bas atkar?ba no temperat?ras virknei emalju, kas var tikt izmantotas saules siltuma kolektoros, k? aizsargp?rkl?jumi. Par?d?ta siltumietilp?bas noteikšanas atk?rtojam?bas atkar?ba no siltuma kontakta. Izstr?d?ta metode termisk? kontakta stabiliz?cijai. Virknei emalju noteikta siltumietilp?bas atkar?ba no temperat?ras diapazon? 20 - 800°?.

  4. Thermodynamic properties of anhydrous smectite MX-80, illite IMt-2 and mixed-layer illite smectite ISCz-1 as determined by calorimetric methods. Part I: Heat capacities, heat contents and entropies

    NASA Astrophysics Data System (ADS)

    Gailhanou, H.; van Miltenburg, J. C.; Rogez, J.; Olives, J.; Amouric, M.; Gaucher, E. C.; Blanc, P.

    2007-11-01

    The heat capacities of the anhydrous international reference clay minerals, smectite MX-80, illite IMt-2 and mixed-layer illite-smectite ISCz-1, were measured by low temperature adiabatic calorimetry and differential scanning calorimetry, from 6 to 520 K (at 1 bar). The samples were chemically purified and Na-saturated. Dehydrated clay fractions <2 ?m were studied. The structural formulae of the corresponding clay minerals, obtained after subtracting the remaining impurities, are K0.026NaCa(SiAl) ( AlFe3+0.184MgFe2+0.038Ti) O(OH)2 for smectite MX-80, K0.762Na(SiAl) ( AlFe3+0.292MgFe2+0.084)O(OH)2 for illite IMt-2 and K0.530Na(SiAl)( AlFe3+0.051MgFe2+0.017Ti) O(OH)2for mixed-layer ISCz-1. From the heat capacity values, we determined the molar entropies, standard entropies of formation and heat contents of these minerals. The following values were obtained at 298.15 K and 1 bar: Cp0 (J mol -1 K -1) S0 (J mol -1 K -1) Smectite MX-80 326.13 ± 0.10 280.56 ± 0.16 Illite IMt-2 328.21 ± 0.10 295.05 ± 0.17 Mixed-layer ISCz-1 320.79 ± 0.10 281.62 ± 0.15

  5. Volume XVI, No. 1 A publication of the U.S. Army Installation Management Agency

    E-print Network

    US Army Corps of Engineers

    . January/February 2004 Vol. XVI, No. 1 Printed on recycled paper. U.S. Army Installation Management Agency of installation services through Common Levels of Support by Karan Foutch 12 Don't be caught by the tire TRAP

  6. Isoperibolic Calorimetric Measurements of the Fleischmann-Pons Effect

    Microsoft Academic Search

    Melvin H. Miles; Martin Fleischmann

    Important advantages exist for selecting a Dewar type isoperibolic calorimeter for measurements of anomalous excess enthalpy produced by the Fleischmann-Pons Effect (FPE). These advantages include a wide dynamic range for both the cell temperature and cell input power, direct visual observations inside the cell during calorimetric experiments, relative low cost, self- purification of the system, the safety of an open

  7. Calorimetric glass transition explained by hierarchical dynamic facilitation

    E-print Network

    Garrahan, Juan P.

    Calorimetric glass transition explained by hierarchical dynamic facilitation Aaron S. Keysa Contributed by David Chandler, February 11, 2013 (sent for review November 15, 2012) The glass transition different on cooling than on heating, and the response to melting a glass depends markedly on the cooling

  8. Gas flow meter based on calorimetric flow microsensor

    NASA Astrophysics Data System (ADS)

    Sazhin, Oleg

    2014-12-01

    A prototype of mass gas flow meter was developed on the basis of calorimetric flow microsensor. Design and manufacturing technology of the flow meter were elaborated. Test procedure was carried out and results were provided. Developed prototype of flow meter can diagnose gas mass flow rates in a wide range.

  9. Calorimetric Vacuum Emissometry At 773 To 923 K

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    Report describes design, construction, and tests of calorimetric vacuum emissometer (CVE) intended to measure total hemispherical emittances of materials in vacuum at temperatures from 773 to 923 K. Results of measurements by CVE compared with those of hohlraum (blackbody) reflectometer and open-air elevated-temperature emissometer. CVE measurements take more time but more accurate.

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  11. Calorimetric Investigation of Hydrogen Bonding of Formamide and Its Methyl Derivatives in Organic Solvents and Water

    NASA Astrophysics Data System (ADS)

    Varfolomeev, Mikhail A.; Rakipov, Ilnaz T.; Solomonov, Boris N.

    2013-04-01

    Formamide and its derivatives have a large number of practical applications; also they are structural fragments of many biomolecules. Hydrogen bonds strongly affect their physicochemical properties. In the present work a calorimetric study of formamide and its methyl derivatives was carried out. Enthalpies of solution at infinite dilution of formamide, N-methylformamide, and N, N-dimethylformamide in organic solvents at 298.15 K were measured. The relationships between the obtained enthalpies of solvation and the structure of the studied compounds were observed. Hydrogen-bond enthalpies of amides with chlorinated alkanes, ethers, ketones, esters, nitriles, amines, alcohols, and water were determined. The strength of hydrogen bonds of formamide, N-methylformamide, and N, N-dimethylformamide with proton donor solvents is practically equal. Enthalpies of hydrogen bonds of formamide with the proton acceptor solvents are two times larger in magnitude than the enthalpies of N-methylformamide. The process of hydrogen bonding of amides in aliphatic alcohols and water is complicated. The obtained enthalpies of hydrogen bonding in aliphatic alcohols vary considerably from the amide structure due to the competition between solute-solvent and solvent-solvent hydrogen bonds. Fourier transform infrared spectroscopic measurements were carried out to explain the calorimetric data. Hydration enthalpies of methyl derivatives of formamides contain a contribution of the hydrophobic effect. New thermochemical data on the hydrogen bonding of formamides may be useful for predicting the properties of biomacromolecules.

  12. A statistical mechanical deconvolution of the differential scanning calorimetric profiles of the thermal denaturation of cyanomethemoglobin.

    PubMed

    Safarian, Shahrokh; Alimohammadi, Masoud; Saberi, Abbas Ali; Moosavi-Movahedi, Ali Akbar

    2005-04-01

    A differential scanning calorimetric study of the thermal unfolding of horse cyanomethemoglobin (as an irreversible protein system) was carried out in phosphate-EDTA buffer (20 mM phosphate, 1 mM EDTA) pH 7.2. The calorimetric rescanning of the protein solution was found to be irreversible and the process unfolded state --> final state appears to follow first order kinetic. Assuming the system to be comprised of n reversible states and one irreversible final state, the number of particles participating in the reversible states changes with time because they ultimately transit to the final irreversible denatured state. Hence, we carried out the deconvolution analysis using the grand canonical ensembles instead of just the canonical ensembles. This change was effected by introducing a correction term into the related equations which determines the outlet share of those particles exiting from the reversible states and converting into the final irreversible state. This approach provided an improved interpretation of the experimental data, which supports the following two-step process for the thermal denaturation of cyanomethemoglobin: alpha(2)beta(2) --> (alpha + alphabeta + beta)(excited) --> alpha(melt) + (alphabeta)(melt) + (beta(melt). PMID:16096723

  13. Characterization of Gels and Networks Using New Calorimetric Techniques

    Microsoft Academic Search

    Jean-Marie Nedelec; Mohamed Baba

    Recent developments of calorimetric techniques for the characterization of porous materials and gels are presented. In particular\\u000a thermoporosimetry is introduced along with recent applications to soft materials like gels and polymers. In a second part,\\u000a photo-DSC technique is presented with the new developments for the study of gels networks and photo-ageing of polymers. An\\u000a overview of the potential of the

  14. 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

    ...IV-A, X, XIV and XVI of the Social Security Act. 233.145 Section 233...IV-A, X, XIV and XVI of the Social Security Act. (a) Under the provisions...IV-A, X, XIV or XVI of the Social Security Act for aid or...

  15. 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

    ...IV-A, X, XIV and XVI of the Social Security Act. 233.145 Section 233...IV-A, X, XIV and XVI of the Social Security Act. (a) Under the provisions...IV-A, X, XIV or XVI of the Social Security Act for aid or...

  16. 45 CFR 233.145 - Expiration of medical assistance programs under titles I, IV-A, X, XIV and XVI of the Social...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...IV-A, X, XIV and XVI of the Social Security Act. 233.145 Section 233...IV-A, X, XIV and XVI of the Social Security Act. (a) Under the provisions...IV-A, X, XIV or XVI of the Social Security Act for aid or...

  17. 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

    ...IV-A, X, XIV and XVI of the Social Security Act. 233.145 Section 233...IV-A, X, XIV and XVI of the Social Security Act. (a) Under the provisions...IV-A, X, XIV or XVI of the Social Security Act for aid or...

  18. Radioactivity measurements of metallic [sup 192]Ir sources by calorimetric methods

    SciTech Connect

    Genka, Tsuguo; Iwamoto, Seikichi; Takeuchi, Norio (Japan Atomic Energy Research Institute, Ibaraki-ken (Japan))

    1992-01-01

    The necessity of establishing the traceability of dose measurement in brachytherapy [sup 192]Ir sources is realized by physicians and researchers in the medical field. Standard sources of various shapes such as [open quotes]hairpin,[close quotes] [open quotes]single pin,[close quotes] [open quotes]thin wire,[close quotes] and [open quotes]seed[close quotes] for calibrating ionization chambers in hospitals are being demanded. Nominal activities of not only these source products but also the standard sources have been so far specified by [open quotes]apparent[close quotes] values. Determination of [open quotes]absolute[close quotes] activity by an established means such as 4pi-beta-gamma coincidence counting is not practical because quantitative dissolution of metallic iridium is very difficult. We tried to determine the [open quotes]absolute[close quotes] activity by a calorimetric method in a fully nondestructive way.

  19. Calorimetric study on the effect of 60Co ?-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 ?-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 ?-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 t? and the growth rate constant ? was developed, which proved the opportunity to use the calorimetric technique in predictive microbiology.

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

    SciTech Connect

    Weisberg, Joel M., E-mail: jweisber@carleton.edu [Department of Physics and Astronomy, Carleton College, Northfield, MN 55057 (United States); Paglen, Trevor, E-mail: trevor@paglen.com

    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.

  1. Nutritional and psycho-physiological assessment of members of the XVI Antarctica expedition

    Microsoft Academic Search

    NARINDER K. SATIJA; ANAJANA G. VIJ; K. SRIDHARAN

    2000-01-01

    The present studies are aimed to evaluate the effects of physiological stress and metabolic requirements necessary to maintain homeostasis and physical and mental functions during stay at Antarctica in expedition members. Nutritional and psycho-physiological assement of the members of the XVI Indian Scientific Expedition to Antarctica was carried alongwith supplementation of vitamins, viz., vitamins, viz., vitamin C and vitamin E

  2. Anjan Chakravartty. A Metaphysics for Scien-tific Realism: Knowing the Unobservable. xvi

    E-print Network

    Chakravartty, Anjan

    Anjan Chakravartty. A Metaphysics for Scien- tific Realism: Knowing the Unobservable. xvi 272 pp., figs., tables, index. Cambridge: Cam- bridge University Press, 2007. £45 (cloth). A Metaphysics to a non-Humean metaphysics, this might be reason enough to make it unattractive to all those who prefer

  3. Low-temperature calorimetric properties of zinc ferrite nanoparticles

    NASA Astrophysics Data System (ADS)

    Ho, J. C.; Hamdeh, H. H.; Chen, Y. Y.; Lin, S. H.; Yao, Y. D.; Willey, R. J.; Oliver, S. A.

    1995-10-01

    Calorimetric measurements between 1 and 40 K by a thermal relaxation technique have been made on zinc ferrite nanoparticles prepared from an aerogel process. The expected ?-type heat-capacity peak near 10 K, which corresponds to a long-range antiferromagnetic transition in the bulk form of this material, is greatly suppressed. Broad peaks begin to prevail after the sample is annealed at 500 or 800 °C, but ball milling of the nanoparticles leads to almost complete disappearance of the low-temperature ordering. In all cases, calorimetrically based magnetic entropy at 40 K accounts for only a fraction of 2R ln(2S+1) with S=5/2 for Fe3+. These results are corroborated by magnetic data, which also indicate magnetic ordering at high temperatures. Such observations can be understood by considering the relative distribution of Fe3+ between two nonequivalent (A and B) sites in the spinel-type lattice. In particular, the as-prepared fine particles show large Fe3+ occupancy of the A sites, whereas these ions prefer the B sites in bulk zinc ferrite. Meanwhile, the lattice heat capacity is enhanced, yielding effective Debye temperatures of 225, 285, 345, and 360 K for the as-prepared, 500 °C-annealed, 800 °C-annealed, and ball milled sample, respectively, in contrast to 425 K for the bulk material.

  4. Empirical free energy calculation: comparison to calorimetric data.

    PubMed Central

    Weng, Z.; Delisi, C.; Vajda, S.

    1997-01-01

    An effective free energy potential, developed originally for binding free energy calculation, is compared to calorimetric data on protein unfolding, described by a linear combination of changes in polar and nonpolar surface areas. The potential consists of a molecular mechanics energy term calculated for a reference medium (vapor or nonpolar liquid), and empirical terms representing solvation and entropic effects. It is shown that, under suitable conditions, the free energy function agrees well with the calorimetric expression. An additional result of the comparison is an independent estimate of the side-chain entropy loss, which is shown to agree with a structure-based entropy scale. These findings confirm that simple functions can be used to estimate the free energy change in complex systems, and that a binding free energy evaluation model can describe the thermodynamics of protein unfolding correctly. Furthermore, it is shown that folding and binding leave the sum of solute-solute and solute-solvent van der Waals interactions nearly invariant and, due to this invariance, it may be advantageous to use a nonpolar liquid rather than vacuum as the reference medium. PMID:9300497

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

    PubMed

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

    2014-12-11

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

  6. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-05-01

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

  8. 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

    ...Docket No. SSA-2012-0006] 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 Social Security...

  9. 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

    ...II and XVI: Agency Processes for Addressing Allegations of Unfairness, Prejudice, Partiality, Bias, Misconduct, or Discrimination by Administrative Law Judges (ALJs); Correction AGENCY: Social Security Administration. ACTION: Notice of Social...

  10. 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

    ...II and XVI: Agency Processes for Addressing Allegations of Unfairness, Prejudice, Partiality, Bias, Misconduct, or Discrimination by Administrative Law Judges (ALJs); Correction AGENCY: Social Security Administration. ACTION: Notice of Social...

  11. 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

    ...II and XVI: Agency Processes for Addressing Allegations of Unfairness, Prejudice, Partiality, Bias, Misconduct, or Discrimination by Administrative Law Judges (ALJs); Correction AGENCY: Social Security Administration. ACTION: Notice of Social...

  12. 20 CFR 408.930 - Are title II and title XVI benefits subject to adjustment to recover title VIII overpayments?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

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

    PubMed Central

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

    2014-01-01

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

  14. A Temporal Map in Geostationary Orbit: The Cover Etching on the EchoStar XVI Artifact

    E-print Network

    Weisberg, J M

    2012-01-01

    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 disc containing one hundred 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 sma...

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

    PubMed

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

    2014-01-01

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

  16. Laser calorimetric absorptance testing of samples with varying geometry

    NASA Astrophysics Data System (ADS)

    Balasa, Istvan; Jensen, Lars O.; Ristau, Detlev

    2014-12-01

    Laser calorimetry is based on the measurement and evaluation of the temperature increase caused by absorption in the sample exposed to laser radiation. A temperature distribution develops in the irradiated sample as a result of dependence on the thermal diffusivity of the sample. Therefore, finding a correlation between the temperature increase and absorption becomes a complex task. This challenge was met by keeping the sample geometry at a standard size and simulating the thermal distribution for a number of optical materials. Using this method, Laser Zentrum Hannover e.V. (LZH) developed a calorimetric test setup that offers fully calibrated absorptance values for sample diameters of 25 mm (or 1 in.) with a total error of below 13% and a relative measurement error of below 5%. However, this technique is limited to the above-mentioned sample geometry. This work presents an approach to adjust the measurement configuration to numerous sample sizes for standard circular laser components. Finite element analysis and experimental verification are presented for exemplary values of the samples' diameters. Based on the different sample mount concept, this procedure allows utilizing flexibility in test wavelength and angle of incidence, combined with the sensitivity level sufficient for current optical materials.

  17. THEORETICAL WAVELENGTHS OF Fe XVI L-SHELL TRANSITIONS AND COMPARISON WITH LABORATORY MEASUREMENTS AND CHANDRA OBSERVATIONS OF CAPELLA

    SciTech Connect

    Beiersdorfer, P. [Physics Division, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Diaz, F.; Ishikawa, Y. [Department of Chemistry and the Chemical Physics Program, University of Puerto Rico, San Juan, PR 00931 (United States)

    2012-02-01

    We have used the relativistic multi-reference Moller-Plesset perturbation theory to calculate the energy levels of Fe XVI, including those of the autoionizing levels with a hole state in the L shell. Comparison of the resulting L-shell transition wavelengths with those from recent laboratory measurements shows remarkable agreement, i.e., agreement within the experimental uncertainties. Our calculation allows us to predict the wavelength of the second strongest 2p-3d Fe XVI line, which has not yet been directly observed in the laboratory, to be 15.266 A. This wavelength is within 0.0042 A of the strong Fe XVII line commonly labeled 3D. Relying on the high accuracy of our calculations, we have reassigned two previously identified lines and predict a different location than previously thought for the strongest Fe XVI magnetic quadrupole transition. Inspection of the spectra of Capella recorded with the transmission grating spectrometers on the Chandra X-ray Observatory yields features corresponding to the predicted location of the innershell excited Fe XVI lines. These features have not been identified before. Our analysis shows that these features are most likely from Fe XVI.

  18. Application of Calorimetric Low Temperature Detectors (CLTD's) for Precise Stopping Power Measurements of Heavy Ions in Matter

    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.

    2014-09-01

    Calorimetric low temperature detectors (CLTD's) have been included in a B-ToF setup, that has already been used several times to perform energy loss measurements at the accelerator laboratory of the University of Jyväskylä. The new experimental setup enabled a precise determination of stopping power data for 0.05-1 MeV/u Xe ions in carbon, nickel and gold. The results are presented and compared to data from literature and theoretical predictions. As a by-product, due to the excellent energy resolution of CLTD's for heavy ions at low energies, an observation of channeling effects in very thin polycrystalline targets and a determination of the channeling energy loss for 0.1-0.5 MeV/u Xe-ions in Ni- and Au-absorbers was possible.

  19. Interaction of methotrexate, folates, and pyridine nucleotides with dihydrofolate reductase: calorimetric and spectroscopic binding studies.

    PubMed Central

    Subramanian, S; Kaufman, B T

    1978-01-01

    The thermodynamic parameters, deltaG, deltaH, and deltaS characterizing the tight binding of methotrexate, folates, and pyridine nucleotides to chicken liver dihydrofolate reductase (5,6,7,8-tetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.3) have been determined from calorimetric and fluorescence measurements. At 25 degrees the binding of NADPH and NADP+ is characterized by small negative enthalpies and large positive entropies whereas the binding of the folates and methotrexate is accompanied by large negative enthalpies and small negative entropies. In addition, the enthalpy of methotrexate-enzyme interaction demonstrates a proton transfer associated with binding; this is not the case with folate and dihydrofolate, thus confirming the conclusions drawn from the observed difference spectra characteristic of the interaction of methotrexate and substrates with the enzyme. The implications of these results are discussed in terms of the nature of the binding process, conformational changes in the enzyme, and the nature of the active site region. PMID:28523

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

    PubMed

    Maskow, T; Babel, W

    2001-07-01

    Compatible solutes are becoming more and more attractive commercially. Thus, knowledge of the efficiency of synthesis of compatible solutes from different carbon substrates is very important. As the growth rate and rates of formation of compatible solutes correspond to the heat flux, calorimetric measurements are particularly suitable for providing this information. By growing microorganisms continuously in a calorimeter, and generating a feeding stream with gradually increasing salinity without changing any other growth conditions, we were able to determine the efficiency of growth-associated synthesis of compatible solutes. This was shown for Halomonas elongata DMSZ 2581(T) growing on glucose, which synthesizes (at 25 degrees C) 1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) as its main osmotic counterweight. The requirement of biologically usable energy for its growth-associated synthesis was found to be very low: a 100% efficiency of the conversion of the substrate-carbon into ectoine is both theoretically possible and was reached approximately in practice. The growth rate and yield coefficient were essentially independent of the ectoine formation rate, and the rate of substrate-carbon assimilation was far greater than the rate of dissimilation. The specific maximum growth rate was limited by the rate of formation of ectoine. PMID:11420137

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

    PubMed

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

    2014-02-14

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

  2. 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.

  3. Comparing M31 and Milky Way Satellites: The Extended Star Formation Histories of Andromeda II and Andromeda XVI

    NASA Astrophysics Data System (ADS)

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

    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; MV = -12.0 log(M sstarf/M ?) ~ 6.7) and Andromeda XVI (And XVI; MV = -7.5 log(M sstarf/M ?) ~ 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. 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.

  4. Collagen XVI induces formation of focal contacts on intestinal myofibroblasts isolated from the normal and inflamed intestinal tract.

    PubMed

    Ratzinger, Sabine; Eble, Johannes A; Pasoldt, Anja; Opolka, Alfred; Rogler, Gerhard; Grifka, Joachim; Grässel, Susanne

    2010-04-01

    In Crohn's disease (CD) the stress-shield of intestinal subepithelial myofibroblasts (ISEMF) provided by intact tissue is disturbed due to inflammation and thus, cells start with remodelling activities. This is characterized by increased numbers of collagen-producing ISEMF causing an uncontrolled, irreversible wound-healing response to the chronic inflammation of the gastrointestinal tract. Reconstitution of the original ECM leads ISEMF to exit this cycle. In contrast, during fibrosis, ISEMF persist. It is known that ISEMF produce and deposit collagen types I, III, IV and V; however synthesis and the role of fibrillar peripheral molecules like collagen type XVI have not been addressed yet. Here, we have analyzed the distribution of collagen XVI in the normal and inflamed bowel wall, its gene and protein expression by ISEMF of different inflammation stages, the cell-matrix interactions in different phases of the inflammatory process and their effect on cell spreading, proliferation and migration. Collagen XVI is deposited in the submucosa of the intestinal wall where it co-localizes with fibrillin-1 and integrin alpha1. ISEMF reveal increasing gene and protein expression of collagen XVI concurrent to increasing inflammation. ISEMF reveal more mature focal adhesion contacts when seeded on collagen XVI resulting in an extensive cell spreading. This involves recruitment of alpha1beta1 integrin, which shows increased cell surface expression on ISEMF in late stages of inflammation. We assume that collagen XVI promotes persistence of ISEMF in the normal and, even stronger in the inflamed bowel wall by stabilizing focal adhesion contacts via cell-matrix interaction preferentially through recruitment of alpha1ss1 integrin into the tips of the focal adhesion contacts. PMID:19931388

  5. [The strength of the shaman in Brazilian colonial medicine of the XVI and XVIII centuries].

    PubMed

    Botelho, João Bosco

    2004-01-01

    The strategy of the colonial conquest of Brazil by the Portuguese, between the XVI and XVIII centuries was linked to the complex set of political, economic and military forces from the Metropolis and the Church. In the first contacts with the Indian populations, on the coast, the colonizing elements, chiefly, the religious ones, perceived the extraordinary importance of the Indian shaman in the organizational structure of the autochthonous populations. Thus, the physical and moral destruction of the Indian shaman and his substitution by healing doctors and priests had become a fundamental part of the plans designed by the Metropolis and the Church in consolidating the territorial conquest. PMID:15726752

  6. Effect of Heat Generation of Ultrasound Transducer on Ultrasonic Power Measured by Calorimetric Method

    NASA Astrophysics Data System (ADS)

    Uchida, Takeyoshi; Kikuchi, Tsuneo

    2013-07-01

    Ultrasonic power is one of the key quantities closely related to the safety of medical ultrasonic equipment. An ultrasonic power standard is required for establishment of safety. Generally, an ultrasonic power standard below approximately 20 W is established by the radiation force balance (RFB) method as the most accurate measurement method. However, RFB is not suitable for high ultrasonic power because of thermal damage to the absorbing target. Consequently, an alternative method to RFB is required. We have been developing a measurement technique for high ultrasonic power by the calorimetric method. In this study, we examined the effect of heat generation of an ultrasound transducer on ultrasonic power measured by the calorimetric method. As a result, an excessively high ultrasonic power was measured owing to the effect of heat generation from internal loss in the transducer. A reference ultrasound transducer with low heat generation is required for a high ultrasonic power standard established by the calorimetric method.

  7. Proceedings of the XVI International Conference on Thermoelectrics, Dresden, Germany, August 26-29, 1997 Skutterudites: An Update

    E-print Network

    technologies. This is true in particular for high power (over 200 W) automobile waste heat recovery and spaceProceedings of the XVI International Conference on Thermoelectrics, Dresden, Germany, August 26 a good potential for achieving ZT values substantially larger than for state-of-the- art thermoelectric

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

    USGS Publications Warehouse

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

    1983-01-01

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

  9. Calorimetric Investigation of Kinetics of Solid Phase Dissolution: Calcium Carbonate Dissolution in Aqueous EDTA Solution

    Microsoft Academic Search

    Nikola Kallay; Vlasta Tomaši?; Suzana Žalac; Ljerka Bre?evi?

    1997-01-01

    The calorimetric method for examination of the kinetics of solid phase dissolution is presented. The thermograms are interpreted by considering the heat evolution due to the reaction as well as the heat transfer in the calorimeter. The kinetic interpretation is based on the change of particle surface area during the dissolution process. The experimental results confirm the applicability of the

  10. First Calorimetric Measurement of OI-line in the Electron Capture Spectrum of $^{163}$Ho

    E-print Network

    P. C. -O. Ranitzsch; C. Hassel; M. Wegner; S. Kempf; A. Fleischmann; C. Enss; L. Gastaldo; A. Herlert; K. Johnston

    2014-08-30

    The isotope $^{163}$Ho undergoes an electron capture process with a recommended value for the energy available to the decay, $Q_{\\rm EC}$, of about 2.5 keV. According to the present knowledge, this is the lowest $Q_{\\rm EC}$ value for electron capture processes. Because of that, $^{163}$Ho is the best candidate to perform experiments to investigate the value of the electron neutrino mass based on the analysis of the calorimetrically measured spectrum. We present for the first time the calorimetric measurement of the atomic de-excitation of the $^{163}$Dy daughter atom upon the capture of an electron from the 5s shell in $^{163}$Ho, OI-line. The measured peak energy is 48 eV. This measurement was performed using low temperature metallic magnetic calorimeters with the $^{163}$Ho ion implanted in the absorber. We demonstrate that the calorimetric spectrum of $^{163}$Ho can be measured with high precision and that the parameters describing the spectrum can be learned from the analysis of the data. Finally, we discuss the implications of this result for the Electron Capture $^{163}$Ho experiment, ECHo, aiming to reach sub-eV sensitivity on the electron neutrino mass by a high precision and high statistics calorimetric measurement of the $^{163}$Ho spectrum.

  11. Calorimetric control for high cell density cultivation of a recombinant Escherichia coli strain

    Microsoft Academic Search

    Richard Biener; Anne Steinkämper; Johannes Hofmann

    2010-01-01

    In order to achieve maximum productivity of recombinant proteins in Escherichia coli high cell density cultivation (HCDC) strategies have been the subject of many studies. The aim of this work was the application of calorimetric methods to HCDC. The specific growth rate of a recombinant E. coli strain producing green fluorescent protein (GFP) was controlled during fed-batch cultivations by estimating

  12. Calorimetric bioprocess monitoring by small modifications to a standard bench-scale bioreactor.

    PubMed

    Schubert, Torsten; Breuer, Uta; Harms, Hauke; Maskow, Thomas

    2007-05-31

    Heat released during whole cell bioconversions provides information about the stoichiometry and kinetics of growth and product formation. It is considered as a potent control variable because it reflects immediately changes in metabolism. Furthermore, the sensitivity of calorimetric measurements is improving with increasing ratios of heat producing volume to heat exchanging surface and therefore with any scaling-up. However, the development and testing of calorimetry-based control strategies at the bench scale is difficult. Common microcalorimeters are unsuited due to their high price, the reactor volume (1-100mL) and the reactor design. Reaction calorimeters are even more expensive, less sensitive than microcalorimeters and often not adapted to bioprocesses. This paper describes a way-out by integrating calorimetric measurement principles into bench-scale standard bioreactors. The proposed solution benefits from all the measurement and control features of bench-scale bioreactors for, e.g. aeration, stirring, pH-control and substrate dosage. The additional calorimetric option can be easily constructed and integrated into an existing bioreactor at relatively low cost. The achieved sensitivity of 50 mW L(-1), stability of 0.2 mW L(-1)h(-1) and response time of a 1-2 min is in the same magnitude or even better than those of established reaction calorimeters. The calorimetrically monitored growth of the halophilic strain Halomonas elongata DMSZ 2581(T) demonstrates the applicability of the proposed solution for bioprocess analysis and control. PMID:17397956

  13. The Hydrogen Bonding of Cytosinewith Guanine:Calorimetric and`H-NMR Analysis

    E-print Network

    Williams, Loren

    The Hydrogen Bonding of Cytosinewith Guanine:Calorimetric and`H-NMR Analysis of the Molecular of hydrogen-bondformation between guanine (G) and cytusine (C) in o-dichloro- benzene and in chloroformat 25°C forming hydrogen bonds. Consequently, hydrogen-bond formation in our system is primarily between the bases

  14. Planck early results. XVI. The Planck view of nearby galaxies

    NASA Astrophysics Data System (ADS)

    Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Battaner, E.; Benabed, K.; Benoît, A.; Bernard, J.-P.; Bersanelli, M.; Bhatia, R.; Bock, J. J.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Bucher, M.; Burigana, C.; Cabella, P.; Cardoso, J.-F.; Catalano, A.; Cayón, L.; Challinor, A.; Chamballu, A.; Chary, R.-R.; Chiang, L.-Y.; Christensen, P. R.; Clements, D. L.; Colombi, S.; Couchot, F.; Coulais, A.; Crill, B. P.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Gasperis, G.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Dole, H.; Donzelli, S.; Doré, O.; Dörl, U.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Harrison, D.; Helou, G.; Henrot-Versillé, S.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hovest, W.; Hoyland, R. J.; Huffenberger, K. M.; Jaffe, A. H.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knox, L.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Leach, S.; Leonardi, R.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; MacTavish, C. J.; Madden, S.; Maffei, B.; Maino, D.; Mandolesi, N.; Mann, R.; Maris, M.; Martínez-González, E.; Masi, S.; Matarrese, S.; Matthai, F.; Mazzotta, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, A.; Naselsky, P.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Pajot, F.; Partridge, B.; Pasian, F.; Patanchon, G.; Peel, M.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Poutanen, T.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Savini, G.; Scott, D.; Seiffert, M. D.; Shellard, P.; Smoot, G. F.; Starck, J.-L.; Stivoli, F.; Stolyarov, V.; Sudiwala, R.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Torre, J.-P.; Tristram, M.; Tuovinen, J.; Türler, M.; Umana, G.; Valenziano, L.; Varis, J.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Yvon, D.; Zacchei, A.; Zonca, A.

    2011-12-01

    The all-sky coverage of the Planck Early Release Compact Source Catalogue (ERCSC) provides an unsurpassed survey of galaxies at submillimetre (submm) wavelengths, representing a major improvement in the numbers of galaxies detected, as well as the range of far-IR/submm wavelengths over which they have been observed. We here present the first results on the properties of nearby galaxies using these data. We match the ERCSC catalogue to IRAS-detected galaxies in the Imperial IRAS Faint Source Redshift Catalogue (IIFSCz), so that we can measure the spectral energy distributions (SEDs) of these objects from 60 to 850?m. This produces a list of 1717 galaxies with reliable associations between Planck and IRAS, from which we select a subset of 468 for SED studies, namely those with strong detections in the three highest frequency Planck bands and no evidence of cirrus contamination. The SEDs are fitted using parametric dust models to determine the range of dust temperatures and emissivities. We find evidence for colder dust than has previously been found in external galaxies, with T < 20K. Such cold temperatures are found using both the standard single temperature dust model with variable emissivity ?, or a two dust temperature model with ? fixed at 2. We also compare our results to studies of distant submm galaxies (SMGs) which have been claimed to contain cooler dust than their local counterparts. We find that including our sample of 468 galaxies significantly reduces the distinction between the two populations. Fits to SEDs of selected objects using more sophisticated templates derived from radiative transfer models confirm the presence of the colder dust found through parametric fitting. We thus conclude that cold (T < 20K) dust is a significant and largely unexplored component of many nearby galaxies. Corresponding author: D. L. Clements, e-mail: d.clements@imperial.ac.uk

  15. 20 CFR 408.931 - How much will we withhold from your title II and title XVI benefits to recover a title VIII...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...much will we withhold from your title II and title XVI benefits to recover a...ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Underpayments and Overpayments Adjustment of Title II Benefits § 408.931 How...

  16. 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 ?-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, ?0Hcrit = 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.

  17. An Empirical Model for the Calorimetrically-Defined Glass Transition Temperature with Applications to Natural Systems

    NASA Astrophysics Data System (ADS)

    Russell, J. K.; Nicholls, J.

    2002-12-01

    Glassy rocks have long held a special fascination for petrologists and geochemists because they record the composition of the melt phase attending magmatic processes. Naturally-occurring silicate glasses form under a variety of geological conditions and they commonly form the main constituent in silicic volcanic rocks and in rapidly cooled mafic rocks. Glass also occurs in rocks with cooling histories that are substantially slower, such as the interiors of lava flows or mantle xenoliths. The glass transition temperature (Tg) marks the transition from the liquid to the glassy state. From a petrological perspective, the calorimetrically-defined glass transition temperature is an important limiting value for the temperature conditions at which many magmatic processes take place. Glass formation is a boundary between changing environmental states. Above Tg, rates of nucleation, crystallization and vesiculation are sufficiently fast to drive magmatic processes. Conversely, where the liquid line of descent (e.g., T-XMelt path) intersects the Tg of the melt, glass forms and many magmatic processes effectively cease. The purpose of this paper is to provide a means of exploring the T-XMelt conditions for glass formation in natural magmatic systems. Specifically, we present an empirical model of predicting the thermodynamic glass transition temperature (Tg) as a function of melt composition. Operationally, the model produces temperature-dependent expressions for the heat contents of a silicate melt and glass of known composition. The point of intersection of the heat content curves for glass and melt defines the calorimetric value of Tg. Our model is constructed from experimental calorimetric heat content and differential scanning calorimetric (DSC) heat capacity measurements on silicate melts and glasses produced over the past 20 years. Calorimetric data in the model include over 500 experiments on 60 melt compositions and 250 observations on 30 glass compositions. Additional constraints on the model derive from independent estimates of the thermodynamic Tg. The model reproduces most of the measured calorimetric-values of Tg to within 30oC. The model also provides volcanologists with a tool for tracking (TMagma-Tg) through magmatic processes such as fractional crystallization, vesiculation, partial melting. It can be used to forecast the termination of liquid lines of descent by glass formation and provides geothermometric constraints on magmatic systems by converting glass compositions into minimum pre-eruption temperatures.

  18. 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 ?-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). The calculated lattice entropy at 298.15 K is Svib = 303.3 J/molK and it contributes about 90% to the total standard entropy at 298 K. The non-lattice entropy is Sex = 33.4 J/molK and consists of Smag = 32.1 J/molK and Sel = 1.3 J/molK contributions. Using the So = 336.7 J/molK value and the Cp polynomial for almandine, we derived its enthalpy of formation, ?Hof, from an analysis of experimental phase equilibrium results on the reactions almandine + 3rutile = 3ilmenite + sillimanite + 2quartz and 2ilmenite = 2iron + 2rutile + O2. ?Hof = -5269.63 kJ/mol was obtained. So for grossular, pyrope, spessartine, and almandine, as well as their Cp behavior to high temperatures, have all been measured calorimetrically. Uncertainties in older calorimetric studies appear to have been resolved. The standard thermodynamic properties Vo and So are now well determined for all four garnets. In addition, ?Hof for all, except possibly spessartine, also appear to be well known.

  19. 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.

  20. Cutting heat dissipation in high-speed machining of carbon steel based on the calorimetric method

    Microsoft Academic Search

    Yanming Quan; Zhenwei He; Yong Dou

    2008-01-01

    The cutting heat dissipation in chips, workpiece, tool and surroundings during the high-speed machining of carbon steel is\\u000a quantitatively investigated based on the calorimetric method. Water is used as the medium to absorb the cutting heat; a self-designed\\u000a container suitable for the high-speed lathe is used to collect the chips, and two other containers are adopted to absorb the\\u000a cutting

  1. Calorimetric studies of Pd\\/D 2O+LiOD electrolysis cells

    Microsoft Academic Search

    Melvin H. Miles

    2000-01-01

    New experiments in sensitive calorimeters displayed the characteristics of the excess power effect during seven different occasions. These measurements clearly show the anomalous increase in the cell temperature despite the steadily decreasing electrical input power during Pd\\/D2O+LiOD\\/Pt electrolysis. This strange behavior can be modeled by the use of an anomalous excess power term in the calorimetric equations. Two thermistors used

  2. Mechanisms of Organic-inorganic Interactions in Soils and Aqueous Environments Elucidated using Calorimetric Techniques

    E-print Network

    Harvey, Omar R.

    2011-08-08

    Mechanisms of Organic-Inorganic Interactions in Soils and Aqueous Environments Elucidated Using Calorimetric Techniques. (May 2010) Omar R. Harvey, B.S. University of the West Indies; M.S., University of Florida Chair of Advisory Committee: Dr... family vi ACKNOWLEDGEMENTS I would like to thank my advisor, Dr. Herbert, and my committee members, Drs. Bill Batchelor, Ronald Kaiser, Patrick Louchouarn, and Youjun Deng, for their assistance and support throughout the course of this research...

  3. Calorimetric Studies of the Behavior of Hydrogen in Vanadium and Vanadium Alloys

    Microsoft Academic Search

    Kenji Watanabe; Yuh Fukai

    1985-01-01

    Calorimetric measurements have been made on vanadium hydride (and deuteride) to investigate the origin of excess specific heat due to H(D) atoms and the mechanism of phase transitions. The specific heat in the alpha phase was found to increase linearly with H(D) concentration at the rate of 2.0± 0.1 kB\\/H atom and 2.4± 0.1 kB\\/D atom at 240°C, nearly independent

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

    SciTech Connect

    Cremers, Teresa L [Los Alamos National Laboratory; Sampson, Thomas E [Los Alamos National Laboratory

    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.

  5. 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. PMID:20307889

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

    PubMed Central

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

    2013-01-01

    Calorimetric and fluorescence techniques were used to characterize the binding of aminoglycosides-neomycin, paromomycin, and ribostamycin, with 5?-dA12-x-dT12-x-dT12-3? intramolecular DNA triplex (x = hexaethylene glycol) and poly(dA).2poly(dT) triplex. Our results demonstrate the following features: (1) UV thermal analysis reveals that the Tm for triplex decreases with increasing pH value in the presence of neomycin, while the Tm for the duplex remains unchanged. (2) The binding affinity of neomycin decreases with increased pH, although there is an increase in observed binding enthalpy. (3) ITC studies conducted in two buffers (sodium cacodylate and MOPS) yield the number of protonated drug amino groups (?n) as 0.29 and 0.40 for neomycin and paromomycin interaction with 5?-dA12-x-dT12-x-dT12-3?, respectively. (4) The specific heat capacity change (?Cp) determined by ITC studies is negative, with more negative values at lower salt concentrations. From 100 mM to 250 mM KCl, the ?Cp ranges from ?402 to ?60 cal/(mol K) for neomycin. At pH 5.5, a more positive ?Cp is observed, with a value of ?98 cal/(mol K) at 100 mM KCl. ?Cp is not significantly affected by ionic strength. (5) Salt dependence studies reveal that there are at least three amino groups of neomycin participating in the electrostatic interactions with the triplex. (6) FID studies using thiazole orange were used to derive the AC50 (aminoglycoside concentration needed to displace 50% of the dye from the triplex) values. Neomycin shows a seven fold higher affinity than paromomycin and eleven fold higher affinity than ribostamycin at pH 6.8. (7) Modeling studies, consistent with UV and ITC results, show the importance of an additional positive charge in triplex recognition by neomycin. The modeling and thermodynamic studies indicate that neomycin binding to the DNA triplex depends upon significant contributions from charge as well as shape complementarity of the drug to the DNA triplex Watson–Hoogsteen groove. PMID:20167243

  7. Calorimetric studies of natural talc: Enthalpy of dehydroxylation

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  8. Elastic and Irreversible Energies of a Two-Stage Martensitic Transformation in NiTi Utilizing Calorimetric Measurements

    NASA Astrophysics Data System (ADS)

    Lanba, Asheesh; Hamilton, Reginald F.

    2014-06-01

    Elastic energy and irreversible energy are quantified based on calorimetric measurements. We analyze energetics for each stage of the stress-free, thermally induced two-stage phase transformation A ? R ? B19' in an aged Ni-rich NiTi shape memory alloy. Heating/cooling rates are imposed from 1 K/min up to 100 K/min. We compare energetic analysis after multiple thermal cycles to virgin ( i.e., first-cycle) material. Fundamental thermodynamic formulations are applied from two perspectives: the free energy change d G, and the rate of change of free energy expressed as d G/d f m. Two measures of irreversible contributions are defined: the difference between the forward and reverse transformation heats, and the product of the entropy and the thermal hysteresis. Higher values are determined for the former. For scan rates of 10 K/min and greater, the energetic values become relatively stable. Substantial variations are evident at 1, 5, and 10 K/min. The scan rate impacts the elastic strain energy and irreversible energy of the B19' markedly compared with the R-phase transition. The findings are rationalized considering morphologic changes at the lower scan rates and the impacts on elastic and irreversible energies.

  9. Simultaneous measurements of high-temperature total hemispherical emissivity and thermal conductivity using a steady-state calorimetric technique

    NASA Astrophysics Data System (ADS)

    Fu, Tairan; Tan, Peng; Duan, Minghao

    2015-01-01

    A method was developed to simultaneously measure the total hemispherical emissivity and the thermal conductivity of samples at high temperatures. The inverse problem to determine the emissivity and thermal conductivity from steady-state high-temperature calorimetric experiments was established based on models for these two quantities. The accuracy of the inverse solution was numerically analyzed for various noise levels for samples with various thermophysical properties. The simulation results illustrate that the calculation accuracies for the emissivity and thermal conductivity strongly depend on the proportions of the radiation and conduction heat fluxes in the strip sample arising from the temperature distributions in the sample. Steady-state high-temperature experiments with nickel samples were used to experimentally verify the method. The inverse solution results for the emissivity and thermal conductivity calculated from the measured data agree well with reported data in the literature. This research provides a useful reference for measuring the total hemispherical emissivity and thermal conductivity of conductive samples at high temperatures.

  10. Photoionization and Electron-Ion Recombination of Ar XVI and Ar XVII

    NASA Astrophysics Data System (ADS)

    Nahar, Sultana

    2012-06-01

    Results on photoionization and electron-ion recombination of Ar XVII and Ar XVII obtained from unified method will be reported. The method, based on relativistic Breit-Pauli R-matrix method and close-coupling approximation, (i) subsumes both the radiative and dielectronic recombination and (ii) provides self-consistent sets of photoionization and recombination cross sections, ?PI and ?RC. Important features for level-specific ?PI and recombination rate coefficients (?R), such as for diagnostic w, x, y, z X-ray lines of Ar XVII in the ultraviolet region of astrophysical spectra will be illustrated. Monochromatic decay dominates the low energy photoionization and low temperature recombination rates. However, high energy resonances in ?PI introduce a DR bump at high temperature recombination. While the 1s-2p core excitations enhance the background of ?PI(nSLJ) at n=2 thresholds. the resonances become much weaker beyond them. The extensive sets of results correspond to fine structure levels with n <=10 and 0 <=l <=9. They include 98 levels of Ar XVI of total angular momenta 1/2 <=J <= 17/2 and 191 levels of Ar XVII of 0 <=J <=9. The present ?R(T) with temperature show good agreement with ava

  11. Characterization of photochemical-cured acrylates with calorimetric methods

    NASA Astrophysics Data System (ADS)

    Strehmel, Bernd; Anwand, Dirk; Wetzel, Henrik

    1994-05-01

    Radical polymerization kinetics of different kinds of diacrylates was investigated in linear polymers (binders) by using an isoperibolic calorimeter. For all experiments benzoin compounds were added as photoinitiator. The ester between acrylic acid and bisphenol-A-diglycidylether (DDGDA) and hexamethylenediacrylate were used as monomers. Both compounds have a high limiting conversion and a large polymerization rate in the binders investigated. Additionally, three kinds of termination reaction were observed: first order, second order, and primary radical termination. The last reaction was mainly found in the case of using the hexamethylenediacrylate monomer. The materials were investigated by DSC to determine the phase behavior. Both monomers form one phase with the binder (polymethylmethacrylate, PMMA). In contrast, a phase separation was observed between the crosslinked hexamethylenediacrylate and PMMA. Formations of semi- interpenetrating networks were found in the case of crosslinked DDGDA and PMMA. The glass transition temperatures were determined at different polymerization degrees also. The obtained results indicate that most of the network formation occurred in the glassy state. Fluorescence probe technique was applied to study changes in the mobility during network formation. The fluorescence probe crystal violet (CV) was used because this compound shows a strong free volume-dependent fluorescence. It was found that in the glassy state, where most of networks were formed, a large variation of the molecular mobility was observed during irradiation of the photopolymers. This result was in agreement with the observations during DSC experiments.

  12. An Isothermal Titration Calorimetric Method to Determine the Kinetic Parameters of Enzyme Catalytic Reaction

    E-print Network

    Luhua, Lai

    of enzyme. The molar reaction heat was calculated from the titration peak area divided by substrate moles per titration, and the initial catalytic reaction rate in the presence of vari- ous concentrations of product can be calculated from the peak height and the molar reaction heat. From Michaelis­Menten function

  13. Universality in gelation of epoxy acrylate with various photoinitiators: a photo differential scanning calorimetric study

    Microsoft Academic Search

    Z. Do?ruyol; F. Karasu; D. K. Balta; N. Arsu; Ö. Pekcan

    2008-01-01

    Photo-differential scanning calorimetric (Photo-DSC) technique was used to study the gelation of P-3038 (epoxy acrylate (EA) 75% and tripropyleneglycoldiacrylate (TPGDA) 25%) in the presence of various thioxanthone-based initiators, namely, thioxanthone (TX), 5-thia-naphtacene-12-one (TX-NP), 2-(carboxymethoxy) thioxanthone (TX-OCH2COOH), 2-thioxanthone-thioacetic acid (TX-SCH2COOH), and 2-mercaptothioxanthone (TX-SH). Photopolymerization reactions were performed under identical conditions of temperature, initiator concentration, and UV light intensity. Photo-DSC technique allowed

  14. The interaction of new piroxicam analogues with lipid bilayers--a calorimetric and fluorescence spectroscopic study.

    PubMed

    Maniewska, Jadwiga; Szcz??niak-Si?ga, Berenika; Po?a, Andrzej; Sroda-Pomianek, Kamila; Malinka, Wies?aw; Michalak, Krystyna

    2014-01-01

    The purpose of the present paper was to assess the ability of new piroxicam analogues to interact with the lipid bilayers. The results of calorimetric and fluorescence spectroscopic experiments of two new synthesized analogues of piroxicam, named PR17 and PR18 on the phase behavior of phospholipid bilayers and fluorescence quenching of fluorescent probes (Laurdan and Prodan), which molecular location within membranes is known with certainty, are shown in present work. The presented results revealed that, depending on the details of chemical structure, the studied compounds penetrated the lipid bilayers. PMID:25856831

  15. Nanowell-patterned TiO2 microcantilevers for calorimetric chemical sensing

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    A sensitive calorimetric sensor using a TiO2 microcantilever with nanowells patterned on one of its sides is described. This single material cantilever is sensitive to temperature change without relying on the metal deposition-based bimetallic effect. The thermomechanical sensitivity originates from the structure dependent variations in both the elastic modulus and thermal expansion coefficient due to the presence of ordered nanowells. These cantilever beams offer an alternate and efficient chemical sensing route for vapor phase analytes using photothermal spectroscopy. Selective and sensitive detection of organophosphorus compounds, as well as their photocatalytic decomposition under ultraviolet light exposure are demonstrated.

  16. Calorimetric study of the interactions between surfactants and dextran modified with deoxycholic acid

    Microsoft Academic Search

    Guangyue Bai; Vasco Castro; Marieta Nichifor; Margarida Bastos

    2010-01-01

    Dextran modified with deoxycholic acid (Dex-DCA) was synthesized by grafting DCA along the polymer backbone, with degrees\\u000a of substitution (DS)—2% and 3%. The thermodynamics of the association processes of the mixed systems is followed by isothermal\\u000a titration calorimetry for sodium deoxycholate\\/sodium dodecyl sulfate (NaDCA\\/NaDS), Dex-DCA with different surfactants—Dex-DCA\\/NaDS,\\u000a Dex-DCA\\/NaDCA, and Dex-DCA\\/DTAB (dodecyltrimethylammonium bromide). Calorimetric measurements for the micellization processes\\u000a of

  17. Thermodynamic properties by non-calorimetric methods: Progress report

    NASA Astrophysics Data System (ADS)

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

    This project for the Office of Energy Research focuses on the noncalorimetric determination of thermodynamic properties of polynuclear aromatic molecules through the extension of existing correlation methodologies and through molecular spectroscopy with statistical mechanics. This report highlights progress during the first third of the contract period. Important advances include: derivation of group-contribution parameters for estimation of thermodynamic properties for polycyclic hydrocarbon and nitrogen-containing compounds; calculation of thermodynamic properties for eight key monocyclic compounds based on new and literature spectra were completed for the derivation of 'ring- correction' property estimation parameters; design and construction of a long pathlength, far-infrared sample cell for the collection of vapor-phase spectra of low vapor-pressure compounds; development of a method to predict the vibrational frequencies of two- and three-ring polycyclic molecules to an accuracy sufficient for identifying the fundamental vibrations in experimental spectra; and development of a method to calculate the kinetic energy expansions as a function of the coordinate for the ring-puckering, ring-twisting (in-phase), and ring-twisting (out-of-phase) vibrations of 9,10-dihydroanthracene and related molecules.

  18. Energetics of target peptide recognition by calmodulin: a calorimetric study.

    PubMed

    Wintrode, P L; Privalov, P L

    1997-03-14

    Calmodulin is a small protein involved in the regulation of a wide variety of intracellular processes. The cooperative binding of Ca2+ to calmodulin's two Ca2+ binding domains induces conformational changes which allow calmodulin to activate specific target enzymes. The association of calmodulin with a peptide corresponding to the calmodulin binding site of rabbit smooth muscle myosin light chain kinase (smMLCKp) was studied using isothermal titration microcalorimetry. The dependence of the binding energetics on temperature, pH, Ca2+ concentration, and NaCl concentration were determined. It is found that the binding of calmodulin to smMLCKp proceeds with negative changes in enthalpy (deltaH), heat capacity (deltaCp), and entropy (deltaS) near room temperature, indicating that it is an enthalpically driven process that is entropically unfavorable. From these results it is concluded that the hydrophobic effect, an entropic effect which favors the removal of non-polar protein groups from water, is not a major driving force in calmodulin-smMLCKp recognition. Although a large number of non-polar side-chains are buried upon binding, these stabilize the complex primarily by forming tightly packed van der Waals interactions with one another. Binding at acidic pH was studied in order to assess the contribution of electrostatic interactions to binding. It is found that moving to acidic pH results in a large decrease in the Gibbs free energy of binding but no change in the enthalpy, indicating that electrostatic interactions contribute only entropically to the binding energetics. The accessible surface area and atomic packing density of the calmodulin-smMLCKp crystal structure are analyzed, and the results discussed in relation to the experimental data. PMID:9086281

  19. Calorimetric and binding dissections of HSA upon interaction with bilirubin.

    PubMed

    Moosavi-Movahedi, Z; Safarian, S; Zahedi, M; Sadeghi, M; Saboury, A A; Chamani, J; Bahrami, H; Ashraf-Modarres, A; Moosavi-Movahedi, A A

    2006-04-01

    The interactions between bilirubin and human serum albumin (HSA) were studied by isothermal titration calorimetry (ITC) and UV-vis spectrophotometry at 27 degrees C in 100 mM phosphate buffer pH 7.4 containing 1 mM EDTA. The biphasic shape of the HSA-bilirubin binding curve depicted the existence of two bilirubin binding sets on the HSA structure which had distinct binding interactions. Each binding set contained one or more bilirubin binding site. The first binding set at subdomain IIA included one binding site and had a more hydrophobic microenvironment than the other two binding sites in the second bilirubin binding set (subdomain IIIA). With our method of analysis, the calculated dissociation constant of the first binding site is 1.28 x 10(-6) M and 4.80 x 10(-4) M for the second and third binding sites. Here, the typical Boltzmann's equation was used with a new approach to calculate the dissociation constants as well as the standard free energy changes for the HSA-bilirubin interactions. Interestingly, our calculations obtained using the Wyman binding potential theory confirmed that our analysis method had been correct (especially for the second binding phase). The molar extinction coefficient determined for the first bound bilirubin molecule depicted that the bilirubin molecules (in low concentrations) should interact with the nonpolar microenvironment of the first high affinity binding site. Binding of the bilirubin molecules to the first binding site was endothermic (deltaH > 0) and occurred through the large increase in the binding entropy established when the hydrophobic bilirubin molecules escaped from their surrounding polar water molecules and into the hydrophobic medium of the first binding site. On the other hand, the calculated molar extinction coefficient illustrated that the microenvironment of the second binding set (especially for the third binding site) was less hydrophobic than the first one but still more hydrophobic than the buffer medium. The binding of the third bilirubin molecule to the HSA molecule was established more through exothermic (electrostatic) interactions. PMID:16721655

  20. 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

    2014-01-01

    A novel miniaturized calorimeter-type sensor device with a dual-catalyst structure was fabricated by integrating different catalysts on the hot (Pd/?-Al2O3) and cold (Pt/?-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/?-Al2O3 catalyst on the cold side to 3 wt%. PMID:24818660

  1. 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/?-Al2O3) and cold (Pt/?-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/?-Al2O3 catalyst on the cold side to 3 wt%. PMID:24818660

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

    PubMed

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

    2010-07-01

    A method is described for calorimetric ac-loss measurements of high-T(c) superconductors (HTS) at 80 K. It is based on a technique used at 4.2 K for conventional superconducting wires that allows an easy loss measurement in parallel or perpendicular external field orientation. This paper focuses on ac loss measurement setup and calibration in a rotating magnetic field. This experimental setup is to demonstrate measuring loss using a temperature rise method under the influence of a rotating magnetic field. The slight temperature increase of the sample in an ac-field is used as a measure of losses. The aim is to simulate the loss in rotating machines using HTS. This is a unique technique to measure total ac loss in HTS at power frequencies. The sample is mounted on to a cold finger extended from a liquid nitrogen heat exchanger (HEX). The thermal insulation between the HEX and sample is provided by a material of low thermal conductivity, and low eddy current heating sample holder in vacuum vessel. A temperature sensor and noninductive heater have been incorporated in the sample holder allowing a rapid sample change. The main part of the data is obtained in the calorimetric measurement is used for calibration. The focus is on the accuracy and calibrations required to predict the actual ac losses in HTS. This setup has the advantage of being able to measure the total ac loss under the influence of a continuous moving field as experienced by any rotating machines. PMID:20687748

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

    SciTech Connect

    Ghoshal, P. K. [Oxford Instruments NanoScience, Abingdon, Oxfordshire OX13 5QX (United Kingdom); Coombs, T. A.; Campbell, A. M. [Department of Engineering, Electrical Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom)

    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.

  4. Soluble expression and sodium channel activity of lt16a, a novel framework XVI conotoxin from the M-superfamily.

    PubMed

    Zhou, Maojun; Wang, Lei; Wu, Yun; Liu, Junliang; Sun, Dandan; Zhu, Xiaoyan; Feng, Yuchao; Qin, Mengying; Chen, Shangwu; Xu, Anlong

    2015-05-01

    A peptide toxin, lt16a, from the venom of the worm-hunting Conus litteratus, shares the typical signal peptide sequences of M-superfamily conotoxins, which usually contain six cysteine residues that are arranged in a CC-C-C-CC pattern. Interestingly, lt16a comprises 21 amino acid residues in its mature region and has a cysteine framework XVI, which is arranged in a C-C-CC pattern. The coding region of lt16a was cloned into the pTRX vector and the fusion protein was overexpressed in Escherichia coli. After cleaving the fusion protein and purifying the protein lt16a using chromatography, the mass of lt16a was found by mass spectrometry to be consistent with the expected mass of 2357.7 Da. Whole-cell patch clamp experiments demonstrated that lt16a could inhibit both the TTX-sensitive and TTX-resistant sodium currents in adult rat dorsal root ganglion neurons. The inhibition of lt16a on TTX-resistant sodium currents was stronger than on TTX-sensitive sodium currents. To our knowledge, this is the first report of a framework XVI conotoxin that can inhibit voltage-gated sodium channel currents in mammalian sensory neurons. This report helps facilitates an understanding of the sequence diversity of conotoxins. PMID:25600641

  5. Inner-shell Absorption Lines of Fe~VI-- Fe~XVI: A Many-body Perturbation Theory Approach

    E-print Network

    Ming F. Gu; Tomer Holczer; Ehud Behar; Steven M. Kahn

    2005-12-15

    We provide improved atomic calculation of wavelengths, oscillator strengths, and autoionization rates relevant to the $2\\to 3$ inner-shell transitions of Fe~VI--XVI, the so-called Fe~M-shell unresolved transition array (UTA). A second order many-body perturbation theory is employed to obtain accurate transition wavelengths, which are systematically larger than previous theoretical results by 15--45~m{\\AA}. For a few transitions of Fe~XVI and Fe~XV where laboratory measurements exist, our new wavelengths are accurate to within a few m{\\AA}. Using these new calculations, the apparent discrepancy in the velocities between the Fe~M-shell UTA and other highly ionized absorption lines in the outflow of NGC 3783 disappears. The oscillator strengths in our new calculation agree well with the previous theoretical data, while the new autoionization rates are significantly larger, especially for lower charge states. We attribute this discrepancy to the missing autoionization channels in the previous calculation. The increased autoionization rates may slightly affect the column density analysis of the Fe~M-shell UTA for sources with high column density and very low turbulent broadening. The complete set of atomic data is provided as an electronic table.

  6. A calorimetric analysis of a polymer electrolyte fuel cell and the production of H2O2 at the cathode

    E-print Network

    Kjelstrup, Signe

    31.08.2009 1 A calorimetric analysis of a polymer electrolyte fuel cell and the production of H2O2 A calorimeter has been constructed and used to measure the total heat production of a single polymer electrolyte and measure the thermal signature of the low temperature polymer electrolyte fuel cell. This paper reports

  7. R. Brugnera -DIS 2008, London 7-11 April 2008 1J/ helicity XVI International Workshop on Deep-Inelastic Scattering and Related Subjects

    E-print Network

    R. Brugnera - DIS 2008, London 7-11 April 2008 1J/ helicity XVI International Workshop on Deep-Inelastic Scattering and Related Subjects London, 7 -11 April 2008 Riccardo Brugnera Padova University and INFN and various theoretical predictions conclusions #12;R. Brugnera - DIS 2008, London 7-11 April 2008 2J

  8. Ocean Optics XVI Conference, Santa Fe, New Mexico, November 18-22, 2002 BIO-OPTICAL EVIDENCE OF LAND-SEA INTERACTIONS

    E-print Network

    Gilbes, Fernando

    Ocean Optics XVI Conference, Santa Fe, New Mexico, November 18-22, 2002 BIO-OPTICAL EVIDENCE Rico. However, the complexity of the bay's optical properties and certain limitations of the technology, allowing a better understanding of such bio-optical variability. A new sampling design with twenty

  9. 'Gold bug' sheds new light on old question Page 1 Vol. XVI, Issue 41 for the Amherst campus of the University of Massachusetts August 24, 2001

    E-print Network

    Lovley, Derek

    'Gold bug' sheds new light on old question Page 1 Vol. XVI, Issue 41 for the Amherst campus of the University of Massachusetts August 24, 2001 Go `Gold bug' sheds new light on old question Lovley uses pollution cleanup technology to explain gold deposits by Paula Hartman Cohen, News Office Staff Derek Lovley

  10. 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."…

  11. Transport and calorimetric studies on CeNi2Al3

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  12. Analytical and experimental characterization of a miniature calorimetric sensor in pulsatile flow

    E-print Network

    Gelderblom, H; Haartsen, J R; Rutten, M C M; van de Ven, A A F; van de Vosse, F N; 10.1017/S0022112010004234

    2011-01-01

    The behaviour of a miniature calorimetric sensor, which is under consideration for catheter-based coronary artery flow assessment, is investigated in both steady and pulsatile tube flow. The sensor is composed of a heating element operated at constant power, and two thermopiles that measure flow-induced temperature differences over the sensor surface. An analytical sensor model is developed, which includes axial heat conduction in the fluid and a simple representation of the solid wall, assuming a quasi-steady sensor response to the pulsatile flow. To reduce the mathematical problem, described by a two-dimensional advection-diffusion equation, a spectral method is applied. A Fourier transform is then used to solve the resulting set of ordinary differential equations and an analytical expression for the fluid temperature is found. To validate the analytical model, experiments with the sensor mounted in a tube have been performed in steady and pulsatile water flow with various amplitudes and Strouhal numbers. E...

  13. 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.

  14. A high pressure calorimetric experiment to validate the liquid-liquid critical point hypothesis in water

    E-print Network

    Manuel I. Marques

    2007-01-23

    An experimental proposal to test the existence of a liquid-liquid critical point in water, based on high pressure calorimetric measurements, is presented on this paper. Considering the existence of an intramolecular correlation in the water molecule we show how the response of the specific heat at high pressure is different depending on the existence, or not, of the second critical point. If the liquid-liquid critical point hypothesis is true there must be a maximum in the specific heat at some temperature $T>T_{H}$ for any pressure $P>P_{c}$ (being $T_{H}$ the homogeneous nucleation temperature and $P_{c}$ the pressure of the second critical point). This maximum does not appear for the singularity free scenario.

  15. Calorimetric and dynamic light-scattering investigation of cationic surfactant--DNA complexes.

    PubMed

    Marchetti, S; Onori, G; Cametti, C

    2006-12-01

    By means of combined calorimetric and dynamic light-scattering measurements, we have investigated the conformational behavior of DNA chains after thermal melting in the presence of a cationic surfactant at different concentrations, up to a surfactant-to-phosphate group molar ratio close to unity. Both the specific heat capacity, C(ex)(p) and the hydrodynamic radius R of the DNA chains provide support for the existence of two structural arrangements with different thermal stabilities, coexisting in the bulk solution. Although a component remains an elongated unfolded DNA chain originated in the thermal denaturation, the second component, consisting of DNA-surfactant complexes, assumes a compact structure with an average size of about 80 nm, whose thermal denaturation occurs at temperatures higher than 100 degrees C. PMID:17134241

  16. 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. PMID:25300415

  17. Idebenone loaded solid lipid nanoparticles: calorimetric studies on surfactant and drug loading effects.

    PubMed

    Sarpietro, Maria Grazia; Accolla, Maria Lorena; Puglisi, Giovanni; Castelli, Francesco; Montenegro, Lucia

    2014-08-25

    In this study we prepared solid lipid nanoparticles (SLN), by the phase inversion temperature (PIT) method, using cetyl palmitate as solid lipid and three different non-ionic emulsifiers of the polyoxyethylene ethers family (ceteth-20, isoceteth-20, oleth-20). These SLN were loaded with different amount of idebenone (IDE), an antioxidant drug useful in the treatment of neurodegenerative diseases and skin oxidative damages. The differential scanning calorimetry (DSC) was employed to evaluate the effects of the different emulsifiers and the different amounts of drug loaded on the thermotropic behavior of SLN and to investigate how the drug was arranged into these nanoparticles. The IDE seemed to be located into different regions of the SLN depending on its concentration and on the surfactant used. The results of this study suggest that the calorimetric studies performed on SLN could provide valuable information to optimize SLN design and drug release from these carriers. PMID:24845103

  18. 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-?-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. PMID:25583305

  19. Concurrent calorimetric and interferometric studies of steady-state natural convection from miniaturized horizontal single plate-fin systems and plate-fin arrays

    E-print Network

    Harahap, Filino

    Concurrent calorimetric and interferometric studies have been conducted to investigate the effect that reduction of the base-plate dimensions has on the steady-state performance of the rate of natural convection heat ...

  20. Concurrent calorimetric and interferometric studies of steady-state natural convection from miniaturized horizontal single plate-fin systems and plate-fin arrays

    Microsoft Academic Search

    Filino Harahap; Herry Lesmana; Poetro Lebdo Sambegoro

    2010-01-01

    Concurrent calorimetric and interferometric studies have been conducted to investigate the effect that reduction of the base-plate\\u000a dimensions has on the steady-state performance of the rate of natural convection heat transfer from miniaturized horizontal\\u000a single plate-fin systems and plate-fin arrays. The effect was studied through comparison of the present results with those\\u000a of earlier relevant calorimetric, interferometric, or numerical studies.

  1. 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

  2. Improvement in the Selectivity of Semiconducting Resistive-type NO2 Sensors Linked with Calorimetric Hydrocarbon Sensors

    NASA Astrophysics Data System (ADS)

    Yamada, Yasushi; Ogita, Masami

    2002-09-01

    Improvement in the selectivity of semiconducting resistive-type NO2 sensors has been achieved by numerical compensation derived from the output of calorimetric hydrocarbon sensors. The electrical resistance of resistive-type sensors using thick-film SnO2 increases due to exposure to NO2, whereas its resistance is decreased by i-C4H10. Oxidizing gases such as O2 and NO2 which are electronegative are adsorbed on the surface of n-type semiconductors, whereas reducing gases such as hydrocarbons and carbon monoxide react with these adsorbed oxidizing gases, causing electrons to return to the semiconductor. Calorimetric sensors are based on the principle of catalytic combustion between reducing gases and atmospheric oxygen on the surface of gas-detecting materials, therefore they are sensitive to reducing gases such as hydrocarbons, but are insensitive to oxidizing gases. It was found that the resistance of NO2 sensors in the range from 0 to 100 ppm NO2 was unaffected by the co-existence of 0 to 300 ppm i-C4H10 using a semiconducting NO2 sensor, a calorimetric sensor and numerical compensation.

  3. Measurement and Modeling of Inner-Shell Satellites of Na-like Fe XVI between 14.5 ?A and 18 ?A

    SciTech Connect

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

    2007-09-10

    We have used the University of California Lawrence Livermore National Laboratory's EBIT-I electron beam ion trap to perform measurements of the wavelengths and relative intensities of the X-ray lines from inner-shell satellite transitions in sodium-like Fe XVI. The measurements were carried out with high-resolution crystal and grating spectrometers and covered the 14.5-18 {angstrom} wavelength band. Contrary to predicted line strengths and positions found in the literature, our results show that the strongest inner-shell satellites of Fe XVI are located near 15.2 {angstrom}. This is near the location of the 3d {yields} 2p intercombination line in Fe XVII. Calculations using the Flexible Atomic Code are presented, which agree well with the EBIT-I measurements.

  4. Phase transitions in the urea/n-nonadecane system by calorimetric techniques.

    PubMed

    López-Echarri, A; Ruiz-Larrea, I; Fraile-Rodríguez, A; Díaz-Hernández, J; Breczewski, T; Bocanegra, E H

    2007-05-01

    A calorimetric study of urea/n-nonadecane, CO(NH(2))(2)/C(19)H(40), and the deuterated derivatives, CO(ND(2))(2)/C(19)D(40) and CO(NH(2))(2)/C(19)D(40), around the structural phase transition temperature is presented. For this purpose differential scanning (DSC), temperature-modulated (AC) and adiabatic calorimetry have been used and the obtained results are compared. Leaving apart the noticeable peak associated with the main phase transition at 158.5, 149.4 and 154 K respectively, small anomalies of the specific heat are found at lower temperatures and their corresponding entropic and enthalpic changes are reported. Heating and cooling experiments show the influence of the temperature rate and the thermal history on the detailed profile of the specific heat traces. The presence of thermal hysteresis and latent heat as a way to characterize the order of the phase transitions is discussed. Finally, a tentative approach to the urea and the alkyl chain contributions to the specific heat and their influence on the phase transition mechanisms is presented. PMID:21691002

  5. 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.

  6. 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.

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

    SciTech Connect

    Miroshnikova, Y. A.; Elsenbeck, M.; Zastavker, Y. V. [Franklin W. Olin College of Engineering, Needham, MA (United States); Kashuri, K; Iannacchione, G. S. [Worcester Polytechnic Institute, Worcester, MA (United States)

    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.

  8. 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. PMID:22459975

  9. 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.

  10. 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.

  11. Temperature-dependent infrared and calorimetric studies on arsenicals adsorption from solution to hematite nanoparticles.

    PubMed

    Sabur, Md Abdus; Goldberg, Sabine; Gale, Adrian; Kabengi, Nadine; Al-Abadleh, Hind A

    2015-03-10

    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 at pH 7. Spectra were collected as a function of concentration and temperature in the range 5-50 °C (278-323 K). Adsorption isotherms were constructed from spectral features assigned to surface arsenic. Values of K(eq), adsorption enthalpy, and entropy were extracted from fitting the Langmuir model to the data and from custom-built triple-layer surface complexation models derived from our understanding of the adsorption mechanism of each arsenical. These spectroscopic and modeling results were complemented with flow-through calorimetric measurements of molar heats of adsorption. Endothermic adsorption processes were predicted from the application of mathematical models with a net positive change in adsorption entropy. However, experimentally measured heats of adsorption were exothermic for all three arsenicals studied herein, with arsenate releasing 1.6-1.9 times more heat than methylated arsenicals. These results highlight the role of hydration thermodynamics on the adsorption of arsenicals, and are consistent with the spectral interpretation of type of surface complexes each arsenical form in that arsenate is mostly dominated by bidentate, MMA by a mixture of mono- and bidentate, and DMA by mostly outer sphere. PMID:25695733

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

    SciTech Connect

    Diaz, F.; Vilkas, M. J.; Ishikawa, Y. [Department of Chemistry and the Chemical Physics Program, University of Puerto Rico, P.O. Box 23346, San Juan, PR 00931-3346 (Puerto Rico); Beiersdorfer, P., E-mail: beiersdorfer1@llnl.gov [Physics Division, Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2013-07-01

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

  13. Determinants

    NSDL National Science Digital Library

    Blake, Lewis

    Created by Lewis Blake and Stephanie Fitchett of the Connected Curriculum Project, the purposes of this module are to explore the properties of determinants of matrices and to develop an important theoretical formula. This is part of a larger collection of material hosted by Duke University.

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

    NASA Astrophysics Data System (ADS)

    Geiger, C. A.; Dachs, E.

    2012-04-01

    The garnet class of phases is extremely broad in terms of composition and structural properties. Garnet is found in nature and various synthetic garnet phases have a number of important technical applications. There exist the rock-forming silicate garnets that are so widespread geologically. An additional class is given by the so-called "hydrogarnets" in which the tetrahedral site (Wyckoff position 24d) is empty. At relatively low temperatures there is complete solid solution between Ca3Al2Si3O12 and Ca3Al2H12O12, for example. The substitution mechanism can be written as O4H4 \\lrarr SiO4. The latter, pure OH-containing end-member, which has not been found in nature, is termed katoite/hydrogrossular. Its structure has been investigated by various workers by X-ray and neutron diffraction and by proton NMR, IR and Raman spectroscopic methods. At ambient conditions the structure has the "standard" garnet cubic symmetry of Ia-3d. At high pressures, and possibly at low temperatures, a different structure may occur. We measured the low temperature IR spectra and heat capacity of katoite in order to understand its structural, crystal-chemical and thermophysical properties. A sample of Ca3Al2H12O12 was synthesized hydrothermally in Au capsules at 250 °C and 3 kb water pressure. X-ray powder measurements show that about 98-99% katoite was obtained. Powder IR spectra were recorded between 298 K and 10 K. The measured spectra are considerably different in the high wavenumber region, where O-H stretching modes occur, between 298 K and 10 K. At room temperature the IR-active O-H band located around 3662 cm-1 is broad and it narrows and shifts to higher wavenumbers and also develops structure below about 80 K. Concomitantly, additional weak intensity O-H bands located around 3600 cm-1 begin to appear and they become sharper and increase in intensity with further decreases in temperature down to 10 K. The spectra indicate that the vibrational behavior of individual OH groups and their collective interactions measurably affect the lattice dynamic (i.e. thermodynamic) behavior. The low temperature heat capacity behavior was investigated with a commercially designed relaxation calorimeter between 5 and 300 K on a mg-sized sample. The heat capacity data are well behaved at T < 300 K and show a monotonic decrease in magnitude with decreasing temperature. A standard third-law entropy value of So = 421.7 ± 1.6 J/mol·K was calculated. Using this new calorimetric-based So value and published standard enthalpy of formation data for katoite, a calorimetric-based Gibbs free energy of formation at 298 K can be obtained as ?G°f = -5021.2 kJ/mol. The Cp data show no evidence for any phase transition as possibly expected by the change in OH-mode behavior with decreasing temperature. We have no explanation for the appearance of the additional modes. It is worth noting that the katoite crystal structure in terms of lattice dynamic or thermodynamic behavior should be thought of having OH groups and not O4H4 clusters or polyhedral units as is often written in the literature. The single crystallographic OH group in katoite shows very weak, if any, hydrogen bonding and the H atoms have large amplitudes of vibration. The weak H bonding controls the nature of low energy OH-related vibrations and this leads to its large So value.

  15. Calorimetric relaxation in pharmaceutical molecular glasses and its utility in understanding their stability against crystallization.

    PubMed

    Tombari, E; Ferrari, C; Johari, G P; Shanker, Ravi M

    2008-09-01

    Glassy states of three pharmaceuticals, acetaminophen, griseofulvin, and nifedipine, and an acetaminophen-aspirin (1:1 mol) alloy were made by slow cooling of the melt and studied by calorimetry. Measurements were performed by cooling and heating at significantly slow rates of 20 K/h, which were comparable to the rate used in adiabatic calorimetry. The results were modeled in terms of a nonexponential, nonlinear structural relaxation. The calorimetric relaxation of all four pharmaceutical samples were less nonexponential than those of polymeric or inorganic glasses, and this finding was attributed to additional contributions to energy change that would arise from temperature and time dependent variation in the hydrogen bond population, the extent of isomerization, and/or the ionic equilibria that exist in these materials. Four calculated and relevant parameters for the pharmaceutical samples were, ln A = -183, beta = 0.75, x = 0.4, and Delta h* = 457 kJ/mol for acetaminophen, ln A = -170, beta = 0.75, x = 0.45, and Delta h* = 516 kJ/mol for griseofulvin, ln A = -189, beta = 0.69, x = 0.39, and Delta h* = 503 kJ/mol for nifedipine, and ln A = -160, beta = 0.70, x = 0.50, and Delta h* = 363 kJ/mol for the acetaminophen-aspirin alloy. The significance of these parameters and, in particular, their values are discussed in the context of the stability of the pharmaceuticals against crystallization and compared against the significance of the localized motions of the JG relaxation in the same context. Acetaminophen was found to be significantly more prone to crystallization on heating than the other two pharmaceuticals as well as the acetaminophen-aspirin alloy. PMID:18683970

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

    NASA Astrophysics Data System (ADS)

    Fortune, Nathanael Alexander

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

  17. 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

  18. Microplate differential calorimetric biosensor for ascorbic acid analysis in food and pharmaceuticals.

    PubMed

    Vermeir, S; Nicolaï, B M; Verboven, P; Van Gerwen, P; Baeten, B; Hoflack, L; Vulsteke, V; Lammertyn, J

    2007-08-15

    In this paper we report on the development of a label-free low-volume (12.5 microL), high-throughput microplate calorimetric biosensor for fast ascorbic acid quantification in food and pharmaceutical products. The sensor is based on microplate differential calorimetry (MiDiCal) technology in which the heat generation, due to the exothermic reaction between ascorbic acid and ascorbate oxidase, is differentially monitored between two neighboring wells of an IC-built wafer. A severe discrepancy is found between expected and observed sensor readings. To investigate the underlying mechanisms of these findings a mathematical model, taking into account the biochemical reactions and diffusion properties of oxygen, ascorbic acid, and ascorbate oxidase, is developed. This model shows that oxygen depletion in the microliter reaction volumes, immediately after injection of sample (ascorbic acid) into the well, causes the enzymatic reaction to slow down. Calibration experiments show that the sensor's signal is linearly correlated to the area under the output versus time profile for the ascorbic acid concentration range from 2.4 to 350 mM with a limit of detection of 0.8 mM. Validation experiments on fruit juice samples, food supplements, and a pain reliever supplemented with ascorbic acid reveal that the designed method correlates well with HPLC reference measurements. The main advantages of the presented biosensor are the low analysis cost due to the low amounts of enzyme and reagents required and the possibility to integrate the device in fully automated laboratory analysis systems for high-throughput screening and analysis. PMID:17616167

  19. Measurement And Modeling Of Fe VIII To Fe XVI M-shell Emission In The Extreme Ultraviolet

    NASA Astrophysics Data System (ADS)

    Beiersdorfer, Peter; Lepson, J. K.; Hurwitz, M.

    2007-05-01

    The solar EUV emission near 200 Å is presently being studied with high resolution with the Cosmic Hot Interstellar Plasma Spectrometer (CHIPS), which focuses on the emission between 90 and 270 Å, and with the EUV Imaging Spectrometer on Hinode, which focuses on the region 180 to 204 Å and 250 to 290 Å. The Solar EUV Experiment on the TIMED spacecraft also observes this spectral band but with greatly reduced resolution. The spectrum in this region is dominated by emission from moderate charge states of iron. The interpretation of the data relies on accurate and complete plasma emission models, notably CHIANTI. We have performed a series of laboratory measurements of the 3-3 emission from M-shell iron ions. The measurements cover the range 170 - 250 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. A few weak transitions are noted in the laboratory data that are predicted by CHIANTI to be vanishingly small and should not have been observed. These are tentatively attributed to transitions in Fe XV. A comparison with observations from CHIPS is also presented. This work was supported in part by NASA's Solar and Heliospheric Physics Supporting Research and Technology Program. Work at UC-LLNL was performed under the auspices of the DOE by under Contract W-7405-Eng-48.

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

    PubMed Central

    Gentili, Rodolfo; Gentili, Elio; Sgorbati, Sergio

    2009-01-01

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

  1. 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.

  2. 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.

  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. 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.

  5. A review of "Taylor’s Gods Determinations and Preparatory Meditations." by Daniel Patterson, ed.

    E-print Network

    William J. Scheick

    2003-01-01

    Determinations and Preparatory Meditations: A Critical Edition. Kent, Ohio: Kent State University Press, 2003. xvi + 583 pp. $65.00. Review by WILLIAM J. SCHEICK, UNIVERSITY OF TEXAS AT AUSTIN. Edward Taylor (1642?-1729), the Cambridge-educated Res- toration... ?migr?, still remains a mystery. At the top of the list of puzzles is the seeming inconsistency between his conservative Cal- vinistic ministry and his Renaissance-faceted verse meditations, especially the poems written between 1682 and 1692...

  6. Calorimetric Study of Adsorption of Alkanes in High-Silica Zeolites Scott Savitz, Flor Siperstein, Raymond J. Gorte, and Alan L. Myers

    E-print Network

    Siperstein, Flor R.

    Calorimetric Study of Adsorption of Alkanes in High-Silica Zeolites Scott Savitz, Flor Siperstein of six high-silica zeolites (TON, MTW, UTD-1, MFI, FER, FAU). Three of these zeolites (TON, MTW, UTD-1 spherical cavities. Since the adsorbate molecules are nonpolar and the zeolites possess a high Si/Al ratio

  7. Dielectric, calorimetric and elastic anomalies associated with the first order [Formula: see text] phase transition in (Ca, Sr)TiO(3) perovskites.

    PubMed

    Manchado, J; Romero, F J; Gallardo, M C; Del Cerro, J; Darling, T W; Taylor, P A; Buckley, A; Carpenter, M A

    2009-07-22

    Conduction calorimetry has been used to determine with high precision the latent heat and variation in heat capacity which accompany the first order [Formula: see text] phase transition in perovskites with compositions (Ca(1-x)Sr(x))TiO(3), x = 0.65, 0.68, 0.74 (CST65, CST68, CST74). In CST65 (CST68), the latent heat is dissipated/absorbed over a temperature interval of ?11 K (?6 K), which is centred on ?292 K (?258 K) during cooling and ?302 K (?270 K) during heating. The magnitude of the latent heat diminishes with increasing SrTiO(3) content and was not detected in CST74. Integration of the latent heat and excess heat capacity yields small excess entropies, which are consistent with the structural changes being displacive rather than order-disorder in origin. Resonant ultrasound spectroscopy measurements on the same CST65 sample as used for dielectric and calorimetric measurements through the same temperature intervals have allowed quantitative correlations to be made with the bulk modulus, shear modulus and acoustic dissipation parameter, Q(-1). The dielectric anomaly and changes in Q(-1) can be understood as being linear combinations of the properties of the separate I4/mcm and Pbcm phases in proportion to their volume fractions across the two-phase field. A change of only ?0.5-1 GPa has been detected in the bulk modulus but the shear modulus softens by ?5-8 GPa as the transition interval is approached from above and below. This shear mode softening presumably reflects clustering and/or phonon softening in both the I4/mcm and Pbcm structures. This pattern of structure-property relations could be typical of first order transitions in perovskites where there is no group/subgroup relationship between the high and low symmetry phases. PMID:21828539

  8. A measurement of the beta spectrum of 63Ni using a new type of calorimetric cryogenic detector

    NASA Astrophysics Data System (ADS)

    Gaitskell, R. J.; Angrave, L. C.; Booth, N. E.; Hahn, A. D.; Salmon, G. L.; Swift, A. M.

    1996-02-01

    A beta spectrometer has been developed using a new type of cryogenic particle detector. The detectors consist of series arrays of superconducting tunnel junctions (SASTJs) fabricated on single crystals of InSb operated at 50 mK. Two detectors are used to completely enclose a beta electron source and are able to make fully calorimetric measurements of beta decay, eliminating both back-scattering and final state effects. We report the results from a precision measurement of the beta spectrum of a 63Ni source. In addition, we will detail the stages in the design and operation of this cryogenic detector which were carried out in order to collect a large number of events (˜10 8) over long periods (˜28 days).

  9. Apparatus for calorimetric measurements of losses in MgB2 superconductors exposed to alternating currents and external magnetic fields

    NASA Astrophysics Data System (ADS)

    Taxt, H.; Magnusson, N.; Runde, M.

    2013-02-01

    Inexpensive superconducting wires with low AC losses would open up for a large superconductor market in AC electrical power applications. One candidate for this market is the MgB2 conductor. In the development of an AC optimized superconductor, high-quality measurements of the AC losses under application-like conditions must be available. This article describes an apparatus built for this purpose. The measurement method is calorimetric. The temperature increase of the superconductor sample is measured and compared to the temperature increase due to a heater with known heat input. The system is designed for measurements of losses due to magnetic fields combined with transport currents. Results from tests verifying the capabilities of the system are given, as well as from initial AC loss measurements on a tape-shaped MgB2 superconductor.

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

    PubMed

    Bartlett, Philip N; Guerin, Samuel

    2003-01-01

    Palladium films with regular nanoarchitectures were electrochemically deposited from the hexagonal (H1) lyotropic liquid crystalline phase of the nonionic surfactant octaethyleneglycol monohexadecyl ether (C16EO8) onto micromachined silicon hotplate structures. The H1-e Pd films were shown to have high surface areas (approximately 28 m2 g(-1)) and to act as effective and stable catalysts for the detection of methane in air on heating to 500 degrees C. The response of the H1-e Pd-coated planar pellistors was found to be linearly proportional to the concentration of methane between 0 and 2.5% in air with a detection limit below 0.125%. Our results show that the electrochemical deposition of nanostructured metal films offers a promising approach to the fabrication of micromachined calorimetric gas sensors for combustible gases. PMID:12530828

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

    NASA Astrophysics Data System (ADS)

    Sears, Derek W. G.

    2012-03-01

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

  12. 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…

  13. Isothermal calorimetric investigation of a reversible reaction in rapidly solidified Fe/sub 40/Fi/sub 40/B/sub 20/

    SciTech Connect

    Cost, J.R.; Elliott, R.O.; Stanley, J.T.

    1983-01-01

    A new method is described for isothermal calorimetric measurement of time-dependent reversible reactions in which the rate of heat flow is small compared to the noise and zero drift of the measurement. Results using this method are presented which measure enthalpy changes associated with reversible phase changes in a rapidly solidified Fe/sub 40/Ni/sub 40/B/sub 20/ alloy.

  14. Backbone nuclear relaxation characteristics and calorimetric investigation of the human Grb7-SH2/erbB2 peptide complex

    PubMed Central

    Ivancic, Monika; Spuches, Anne M.; Guth, Ethan C.; Daugherty, Margaret A.; Wilcox, Dean E.; Lyons, Barbara A.

    2005-01-01

    Grb7 is a member of the Grb7 family of proteins, which also includes Grb10 and Grb14. All three proteins have been found to be overexpressed in certain cancers and cancer cell lines. In particular, Grb7 (along with the receptor tyrosine kinase erbB2) is overexpressed in 20%–30% of breast cancers. Grb7 binds to erbB2 and may be involved in cell signaling pathways that promote the formation of metastases and inflammatory responses. In a prior study, we reported the solution structure of the Grb7-SH2/erbB2 peptide complex. In this study, T1, T2, and steady-state NOE measurements were performed on the Grb7-SH2 domain, and the backbone relaxation behavior of the domain is discussed with respect to the potential function of an insert region present in all three members of this protein family. Isothermal titration calorimetry (ITC) studies were completed measuring the thermodynamic parameters of the binding of a 10-residue phosphorylated peptide representative of erbB2 to the SH2 domain. These measurements are compared to calorimetric studies performed on other SH2 domain/phosphorylated peptide complexes available in the literature. PMID:15930003

  15. 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.

  16. A base-triggerable catanionic mixed lipid system: isothermal titration calorimetric and single-crystal X-ray diffraction studies.

    PubMed

    Tarafdar, Pradip K; Reddy, S Thirupathi; Swamy, Musti J

    2010-11-01

    Lipid-based, base-triggerable systems will be useful for colon specific targeted delivery of drugs and pharmaceuticals. In light of this, a catanionic surfactant system, composed of O-lauroylethanolamine hydrochloride (OLEA·HCl) and sodium dodecyl sulfate (SDS), has been designed. The aggregates formed by near equimolar mixtures of OLEA·HCl-SDS have shown lability at basic pH, indicating that the system may be useful for developing colon specific drug delivery system(s). Turbidimetric and isothermal titration calorimetric studies revealed that OLEA·HCl forms a 1:1 (mol/mol) complex with SDS. The three-dimensional structure of the equimolar OLEA-SDS complex has been solved by single-crystal X-ray diffraction. Analysis of the molecular packing and intermolecular interactions in the crystal lattice revealed a hydrogen bonding belt in the headgroup region of the complex and dispersion interactions among the acyl chains as the main factors stabilizing the complex. These observations will be useful in understanding specific interactions between lipids in more complex systems, e.g., biomembranes. PMID:20936832

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

    PubMed

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

    2012-03-01

    Orthodontic treatment is strongly dependent on the loads developed by metal wires, and the choice of an orthodontic archwire should be based on its mechanical performance. The desire of both orthodontists and engineers would be to predict the mechanical behavior of archwires. To this aim, Gum Metal (Toyota Central R&L Labs., Inc.), TMA (ORMCO), 35°C Copper NiTi (SDS ORMCO), Thermalloy Plus (Rocky Mountain), Nitinol SE (3M Unitek), and NiTi (SDS ORMCO) were tested according to dynamic mechanical analysis and differential scanning calorimetry. A model was also developed to predict the elastic modulus of superelastic wires. Results from experimental tests have highlighted that superelastic wires are very sensitive to temperature variations occurring in the oral environment, while the proposed model seems to be reliable to predict the Young's modulus allowing to correlate calorimetric and mechanical data. Furthermore, Gum Metal wire behaves as an elastic material with a very low Young's modulus, and it can be particularly useful for the initial stage of orthodontic treatments. PMID:21343211

  18. 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…

  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%. PMID:7207427

  20. Effects of exposure of chloroquine picrate to the sun: A differential scanning calorimetric study

    Microsoft Academic Search

    I. O. Edafiogho; J. R. Mulokozi; A. M. Mulokozi; S. Diete-Spiff

    1988-01-01

    In a continuing study of the effect of exposure of chloroquine and its salt derivatives to the sun, the picrate was investigated. The picrate gives a sharp endothermic effect of melting at 209.2 °C, before it decomposes, to give an exothermic peak at 255.6 °C. The endothermic peak of melting at 209.2 °C was found suitable for the quantitative determination

  1. Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

    PubMed Central

    Romero, Jorge Marcelo; Bustillo, Soledad; Maisuls, Hugo Enrique Ramirez; Jorge, Nelly Lidia; Vara, Manuel Eduardo Gómez; Castro, Eduardo Alberto; Jubert, Alicia H.

    2007-01-01

    A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. 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 This set level. Some possible extensions of the present procedure are pointed out.

  2. Differential scanning calorimetric analysis of edible oils: Comparison of thermal properties and chemical composition

    Microsoft Academic Search

    C. P. Tan; Y. B. Che Man

    2000-01-01

    The thermal profiles of 17 edible oil samples from different plant origins were examined by differential scanning calorimetry\\u000a (DSC). Two other confirmatory analytical techniques, namely gas-liquid chromatography (GLC) and high-performance liquid chromatography\\u000a (HPLC), were used to determine fatty acid (FA) and triacylglycerol (TAG) compositions. The FA and TAG compositions were used\\u000a to complement the DSC data. Iodine value (IV) analysis

  3. Calorimetric and Resistive Measurements of Amorphous Splat Cooled La1-Xgax Foils

    E-print Network

    SHULL, WH; Naugle, Donald G.; POON, SJ; JOHNSON, WL.

    1978-01-01

    been measured for a series of La~ ?Ga?alloys with x =0.16?x =0.28. Values of the Debye temp- erature, density of states, and electron-phonon coupling constant have been determined from these measurements. Superconductivity in this amorphous system... for x between 0.22 and 0.26. I. INTRODUCTION Considerable progress has been made towards the understanding of amorphous superconducting metals since their discovery by Buckel and Hilsch. ' However, most of the experiments on amorphous superconduc...

  4. Conformational stability of bovine holo and apo adrenodoxin--a scanning calorimetric study.

    PubMed

    Burova, T V; Bernhardt, R; Pfeil, W

    1995-05-01

    Holo and apo adrenodoxin were studied by differential scanning calorimetry, absorption spectroscopy, limited proteolysis, and size-exclusion chromatography. To determine the conformational stability of adrenodoxin, a method was found that prevents the irreversible destruction of the iron-sulfur center. The approach makes use of a buffer solution that contains sodium sulfide and mercaptoethanol. The thermal transition of adrenodoxin takes place at Ttrs = 46-57 degrees C, depending on the Na2S concentration with a denaturation enthalpy of delta H = 300-380 kJ/mol. From delta H versus Ttrs a heat capacity change was determined as delta Cp = 7.5 +/- 1.2 kJ/mol/K. The apo protein is less stable than the holo protein as judged by the lower denaturation enthalpy (delta H = 93 +/- 14 kJ/mol at Ttrs = 37.4 +/- 3.3 degrees C) and the higher proteolytic susceptibility. The importance of the iron-sulfur cluster for the conformational stability of adrenodoxin and some conditions for refolding of the thermally denatured protein are discussed. PMID:7663346

  5. Composite bone cements loaded with a bioactive and ferrimagnetic glass-ceramic. Part I: Morphological, mechanical and calorimetric characterization.

    PubMed

    Bruno, Matteo; Miola, Marta; Bretcanu, Oana; Vitale-Brovarone, Chiara; Gerbaldo, Roberto; Laviano, Francesco; Verné, Enrica

    2014-02-01

    Hyperthermia is a technique for destroying cancer cells which involves the exposition of body's tissue to a controlled heat, normally between 41? and 46?. It has been reported that ferro- or ferrimagnetic materials can heat locally, if they are placed (after being implanted) under an alternating magnetic field, damaging only tumoral cells and not the healthy ones. The power loss produced by the magnetic materials can be dissipated in the form of heat. This phenomenon has to be regulated in order to obtain a controlled temperature inside the tissues. The material that was produced and characterized in this work is composed of two phases: a polymethylmethacrylate (PMMA) matrix in which a ferrimagnetic biocompatible/bioactive glass ceramic is dispersed. This composite material is intended to be applied as bone filler for the hyperthermic treatment of bone tumors. The ferrimagnetic bioactive glass-ceramic belongs to the system SiO2-Na2O-CaO-P2O5-FeO-Fe2O3 and contains magnetite (FeO*Fe2O3) inside an amorphous bioactive residual phase. The composite material possesses structural, magnetic and bioactivity properties. The structural ones are conferred by PMMA which acts as filler for the bone defect or its damaged area. Bioactivity is conferred by the composition of the residual amorphous phase of the glass-ceramic and magnetic properties are conferred by magnetite crystals embedded in the bioactive glass-ceramic. The characterization involved the following tests: morphological and chemical characterization (scanning electron microscopy-energy dispersion spectrometry-micro computed tomography analysis), calorimetric tests and mechanical test (compression and flexural four point test). In vitro assessment of biological behavior will be the object of the part II of this work. PMID:24505077

  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. 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.

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

    PubMed Central

    Benisek, Artur; Dachs, Edgar

    2013-01-01

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

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

    PubMed

    Benisek, Artur; Dachs, Edgar

    2013-07-01

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

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

    NASA Astrophysics Data System (ADS)

    Magli?, K. D.; Perovi?, N. Lj.; Stanimirovi?, A. M.

    1994-07-01

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

  11. Specific binding of hoechst 33258 to the d(CGCAAATTTGCG)2 duplex: calorimetric and spectroscopic studies.

    PubMed

    Haq, I; Ladbury, J E; Chowdhry, B Z; Jenkins, T C; Chaires, J B

    1997-08-15

    Fluorescence spectroscopy and high-sensitivity isothermal titration calorimetry (ITC) techniques have been used to examine the binding characteristics of Hoechst 33258 with the extended AT-tract DNA duplex d(CGCAAATTTGCG)2 in aqueous solution. The method of continuous variation reveals a 1:1 binding stoichiometry. Fluorescence equilibrium studies carried out at three different, but fixed, ligand concentrations show that the binding isotherm shifts towards higher [DNA] as the concentration of ligand is increased. The data show tight binding with Kb=3.2(+/-0.6)x10(8) M(duplex)-1 at 25 degrees C in solutions containing 200 mM Na+. Based on UV studies of duplex melting, which show that strand separation starts at approximately 35 degrees C and has a Tm at 54 degrees C in 300 mM NaCl, binding enthalpies were determined by ITC in the 10 to 30 degrees C range. Binding is endothermic at all temperatures examined, with DeltaH values ranging from +10.24(+/-0.18) to +4.2(+/-0.10) kcal mol(duplex)-1 at 9.4 degrees C and 30.1 degrees C, indicating that the interaction is entropically driven. The temperature dependence of DeltaH shows a binding-induced change in heat capacity (DeltaCp) of -330(+/-50) cal mol-1 K-1. This value is similar to that predicted from a consideration of the effects of hydrophobic and hydrophilic solvent-accessible surface burial on complexation. This result, almost entirely dictated by a removal from exposure of the non-polar reactant surfaces, represents the first demonstration of such behavior in a DNA-drug system. The salt dependence of the binding constant was examined using reverse-salt fluorescence titrations, with a value of 0.99 determined for the deltalnK/deltaln[Na+] parameter. These data provide a detailed thermodynamic profile for the interaction that enables a dissection of DeltaGobs into the component free energy terms. Analysis of data obtained at 25 degrees C reveals that DeltaGobs is dominated by the free energy for hydrophobic transfer of ligand from solution to the DNA binding site. Molecular interactions, including H-bonding and van der Waals contacts, are found to play only a minor role in stabilizing the resulting complex, a somewhat surprising finding given the emphasis placed on such interactions from structural studies. PMID:9268656

  12. A calorimetric mass gauge system for the Cosmic Background Explorer (COBE)

    NASA Technical Reports Server (NTRS)

    Volz, Stephen M.; Dipirro, Michael J.; Ryschkewitsch, Michael G.

    1990-01-01

    A system for the COBE flight dewar to measure its liquid helium fill is presented. A small known amount of heat is applied to the helium tank and monitor the temperature rise in the liquid and the tank. Working with a detailed thermal model of the tank and liquid the amount of liquid present is determined. COBE uses a 117-mW, 7-mA heater to warm the helium. It is planned to use the mass gaging system only after the projected midpoint of the mission, after one full sky survey. The system is optimized for use with 50-75 liters of helium. Ground testing of the system in a one-gravity environment is difficult, but from tests conducted so far, an on-orbit temperature rise of about 2.5 mK/min is estimated. A similar system is planned for the Superfluid Helium On-Orbit Transfer (SHOOT), a Shuttle-based experiment. The SHOOT's specific requirements call for a high-power pulse heater, applying 40 W for approximately 20 seconds.

  13. Calorimetric studies of Cu–Li, Li–Sn, and Cu–Li–Sn

    PubMed Central

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

    2013-01-01

    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. PMID:23814314

  14. 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. PMID:25093830

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

    PubMed Central

    Krivanek, Roland; Okoro, Linus; Winter, Roland

    2008-01-01

    Although sterol-phospholipid interactions have been of interest for many years now, a complete thermodynamic profile of these systems is still missing. To contribute to a better understanding of the thermodynamic functions of these systems, we determined isothermal compressibility coefficient data for dipalmitoylphosphocholine (DPPC) and DPPC-containing cholesterol and ergosterol vesicles by means of molecular acoustics (ultrasound velocimetry and densimetry) and differential scanning and pressure perturbation calorimetric techniques. A particular focus was on the influence of the differential structural properties of the two sterols on the thermodynamic properties of lipid bilayers, and on the nature of the critical point region of phospholipid-sterol systems by determining thermodynamic fluctuation parameters. Contrary to significant changes in conformational and dynamical properties of the DPPC-sterol membranes, no marked differences were found in the various thermodynamic properties studied, including the adiabatic (\\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\beta}_{{\\mathrm{S}}}^{{\\mathrm{lipid}}}\\end{equation*}\\end{document}) and isothermal (\\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\beta}_{{\\mathrm{T}}}^{{\\mathrm{lipid}}}\\end{equation*}\\end{document}) compressibility, as well as the volume fluctuations. Differences in \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\beta}_{{\\mathrm{T}}}^{{\\mathrm{lipid}}}\\end{equation*}\\end{document} and \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\beta}_{{\\mathrm{S}}}^{{\\mathrm{lipid}}}\\end{equation*}\\end{document} become dramatic in the gel-fluid transition region only, due to a significant degree of slow relaxational processes in the microsecond time range in the transition region. Our data show no evidence for the existence of a typical critical point phenomenon in the concentration and temperature range where a critical point in the DPPC-sterol phase diagram is expected to appear. Hence, on a macroscopic level, it seems more appropriate to describe the sterol-phospholipid binary mixtures in the liquid-ordered/liquid-disordered coexistence region as a phase region consisting essentially of small nanodomains only. Such small-domain dimensions, with a series of particular properties such as increased line energy, spontaneous curvature, and limited lifetime, seem also to be typical of raftlike domains in cell membranes. PMID:18199673

  16. Characterisation of fresh and aged terpenic resins by micro-FTIR and GC-MS analyses of varnishes in XVI-XVII centuries paintings.

    PubMed

    Cartoni, Giampaolo; Russo, Mario Vincenzo; Spinelli, Francesca; Talarico, Fabio

    2003-11-01

    Resinous materials, generally added to drying oils, were often employed as final protective films in paintings, both in tempera and oil techniques. Most of the resins used in fine arts come from exudates of plants. Natural resins are mainly composed by terpenoids. Among these resins, dammar, rosin, mastic, elemi gum, Venice turpentine were frequently employed in easel paintings. The aim of this work is the identification of natural resins in samples collected from works of art. In this paper we propose to use micro-FTIR spectrometry as a preliminary and non destructive technique to detect the presence of resinous materials in microsamples collected from paintings, followed by GC-MS analyses to obtain a precise identification of the resin. To reach this aim commercial resins, employed as standard, were analysed previously by micro-FTIR spectrometry and then analysed by GC-MS chromatography, searching characteristic chemical compounds used as "markers" of resins. The results obtained on standards allowed us to successfully analyse samples collected from two works of art: the "Portrait of a Young Gentleman", by Lorenzo Lotto (XVI century), and the "Madonna with the Infant Jesus and Saints": by Carlo Maratta (XVII secolo). PMID:14703854

  17. 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.

  18. Effect of lamellarity and size on calorimetric phase transitions in single component phosphatidylcholine vesicles.

    PubMed

    Drazenovic, Jelena; Wang, Hairong; Roth, Kristina; Zhang, Jiangyue; Ahmed, Selver; Chen, Yanjing; Bothun, Geoffrey; Wunder, Stephanie L

    2015-02-01

    Nano-differential scanning calorimetry (nano-DSC) is a powerful tool in the investigation of unilamellar (small unilamellar, SUVs, or large unilamellar, LUVs) vesicles, as well as lipids on supported bilayers, since it measures the main gel-to-liquid phase transition temperature (Tm), enthalpies and entropies. In order to assign these transitions in single component systems, where Tm often occurred as a doublet, nano-DSC, dynamic light scattering and cryo-transmission electron microscopy (cryo-TEM) data were compared. The two Tms were not attributable to decoupled phase transitions between the two leaflets of the bilayer, i.e. nano-DSC measurements were not able to distinguish between the outer and inner leaflets of the vesicle bilayers. Instead, the two Tms were attributed to mixtures of oligolamellar and unilamellar vesicles, as confirmed by cryo-TEM images. Tm for the oligolamellar vesicles was assigned to the peak closest to that of the parent multilamellar vesicle (MLV) peak. The other transition was higher than that of the parent MLVs for 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and increased in temperature as the vesicle size decreased, while it was lower in temperature than that of the parent MLVs for 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and decreased as the vesicle size decreased. These subtle shifts arose due to small differences in the values of ?H and ?S, since Tm is determined by their ratio (?H/?S). It was not possible to completely eliminate oligolamellar structures for MLVs extruded with the 200nm pore size filter, even after 120 passes, while these structures were eliminated for MLVs extruded through the 50nm pore size filter. PMID:25445167

  19. Calorimetric, optical and catalytic activity studies of europium chloride-polyvinyl alcohol composite system

    NASA Astrophysics Data System (ADS)

    Mahmoud, Khaled H.; El-Bahy, Zeinhom M.; Hanafy, Ahmed I.

    2011-09-01

    Polyvinyl alcohol (PVA) films doped with europium chloride (EuCl3) have been prepared by casting from their aqueous solutions. The phase transitions and thermal decomposition behavior of the prepared samples were investigated by thermal analysis and the interactions between the host PVA and Eu3+ were examined by FTIR spectroscopy. The optical absorption was recorded at room temperature in the range of 190-1000 nm. From the absorption edge studies, the values of the Urbach energy (Ee) were found to be 0.56 eV in case of the pure polymer; however, its value increased to be in the range of 1.21-1.75 eV. These energy values indicate that the model based on electronic transitions between localized states is not preferable and transitions are made between band tails. Optical parameters such as refractive index and complex dielectric constant have been determined. The dispersion of the refractive index is discussed in terms of the single-oscillator Wemple-DiDomenico model. Color properties of the prepared samples are discussed in the framework of CIE L*u*v* color space. The prepared samples have been used as catalysts in the photocatalytic degradation of p-nitrophenol (PNP) in aqueous solution under UV light irradiation using H2O2 as oxidizing agent. The catalytic activity of the Eu-polymer towards the photodegradation of PNP greatly increased after doping with Eu3+ ions. The highest catalytic activity was noticed at the optimum pH value of 5.5.

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

    SciTech Connect

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

    2009-10-01

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

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

    SciTech Connect

    Ktari, L. [Laboratoire de l'Etat Solide (LES), Faculte des Sciences de Sfax, 3000 Sfax (Tunisia); Abdelhedi, M. [Laboratoire de l'Etat Solide (LES), Faculte des Sciences de Sfax, 3000 Sfax (Tunisia); Laboratoire Leon Brouillon LLB, CEA Saclay, 91191 Gif-Sur-Yvette Cedex (France); Bouhlel, N. [Laboratoire de l'Etat Solide (LES), Faculte des Sciences de Sfax, 3000 Sfax (Tunisia); Dammak, M., E-mail: meddammak@yahoo.fr [Laboratoire de l'Etat Solide (LES), Faculte des Sciences de Sfax, 3000 Sfax (Tunisia); Cousson, A. [Laboratoire Leon Brouillon LLB, CEA Saclay, 91191 Gif-Sur-Yvette Cedex (France)

    2009-08-05

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

  2. 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 (?T) 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=?T4) - 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 campaigns during the two years of nominal operation of the rover curiosity on Mars.

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

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

    The thermodynamic properties of three aluminous 2:1 clay minerals were acquired at 1.013 bars and at temperatures between 5 and 500 K using various calorimetric methods. Calorimetric measurements were performed on hydrated and dehydrated <2 ?m clay fractions of smectite MX-80 (Wyoming), illite IMt-2 (Silver Hill) and beidellite SBId-1 (Black Jack Mine). After purification, the mineralogical analyses gave the following structural formulae: NaKCa(SiAl)(AlMgFe0.1733+Fe0.0352+)O(OH)2,KNa(SiAl)(AlMgFe0.2923+Fe0.0842+)O(OH)2 and CaK(SiAl)(AlMgFe0.1123+)O(OH)2 for smectite MX-80, illite IMt-2 and beidellite SBId-1, respectively. Heat capacities were measured by low temperature adiabatic calorimetry and differential scanning calorimetry, from 5 to 500 K. Standard enthalpies of formation were obtained from solution-reaction calorimetry at 298.15 K. The standard Gibbs free energies of formation of the clay minerals were also calculated, together with the equilibrium constants at 25 °C, for anhydrous and hydrated minerals. A comparison between these experimental data and estimated values obtained from prediction models available in the literature, enabled the calculation method that appears to be the most relevant to be selected, at least for aluminous 2:1 clay minerals.

  4. 78 FR 11939 - Social Security Ruling, SSR 13-2p.; Titles II and XVI: Evaluating Cases Involving Drug Addiction...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-20

    ...impairment(s) that results in disability \\16\\ and DAA is not causing...material to the determination of disability. The claim should be allowed...requires chronic dialysis, or intellectual disability (mental retardation)...

  5. Micromechanical calorimetric sensor

    DOEpatents

    Thundat, Thomas G. (Knoxville, TN); Doktycz, Mitchel J. (Knoxville, TN)

    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.

  6. 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.

  7. Calorimetric, X-Ray Diffraction, and Spectroscopic Studies of the Thermotropic Phase Behavior and Organization of Tetramyristoyl Cardiolipin Membranes

    PubMed Central

    Lewis, Ruthven N. A. H.; Zweytick, Dagmar; Pabst, Georg; Lohner, Karl; McElhaney, Ronald N.

    2007-01-01

    The thermotropic phase behavior and organization of aqueous dispersions of the quadruple-chained, anionic phospholipid tetramyristoyl diphosphatidylglycerol or tetramyristoyl cardiolipin (TMCL) was studied by differential scanning calorimetry, x-ray diffraction, 31P NMR, and Fourier-transform infrared (FTIR) spectroscopy. At physiological pH and ionic strength, our calorimetric studies indicate that fully equilibrated aqueous dispersions of TMCL exhibit two thermotropic phase transitions upon heating. The lower temperature transition is much less cooperative but of relatively high enthalpy and exhibits marked cooling hysteresis, whereas the higher temperature transition is much more cooperative and also exhibits a relatively high enthalpy but with no appreciable cooling hysteresis. Also, the properties of these two-phase transitions are sensitive to the ionic strength of the dispersing buffer. Our spectroscopic and x-ray diffraction data indicate that the lower temperature transition corresponds to a lamellar subgel (Lc?) to gel (L?) phase transition and the higher temperature endotherm to a L? to lamellar liquid-crystalline (L?) phase transition. At the Lc?/L? phase transition, there is a fivefold increase of the thickness of the interlamellar aqueous space from ?11 Å to ?50 Å, and this value decreases slightly at the L?/L? phase transition. The bilayer thickness (i.e., the mean phosphate-phosphate distance across the bilayer) increases from 42.8 Å to 43.5 Å at the Lc?/L? phase transition, consistent with the loss of the hydrocarbon chain tilt of ?12°, and decreases to 37.8 Å at the L?/L? phase transition. The calculated cross-sectional areas of the TMCL molecules are ?79 Å2 and ?83 Å2 in the Lc? and L? phases, respectively, and we estimate a value of ?100 Å2 in the L? phase. The combination of x-ray and FTIR spectroscopic data indicate that in the Lc? phase, TMCL molecules possess tilted all-trans hydrocarbon chains packed into an orthorhombic subcell in which the zig-zag planes of the chains are parallel, while in the L? phase the untilted, all-trans hydrocarbon chains possess rotational mobility and are packed into a hexagonal subcell, as are the conformationally disordered hydrocarbon chains in the L? phase. Our FTIR spectroscopic results demonstrate that the four carbonyl groups of the TMCL molecule become progressively more hydrated as one proceeds from the Lc? to the L? and then to the L? phase, while the two phosphate moieties of the polar headgroup are comparably well hydrated in all three phases. Our 31P-NMR results indicate that although the polar headgroup retains some mobility in the Lc? phase, its motion is much more restricted in the L? and especially in the L? phase than that of other phospholipids. We can explain most of our experimental results on the basis of the relatively small size of the polar headgroup of TMCL relative to other phospholipids and the covalent attachment of the two phosphate moieties to a single glycerol moiety, which results in a partially immobilized polar headgroup that is more exposed to the solvent than in other glycerophospholipids. Finally, we discuss the biological relevance of the unique properties of TMCL to the structure and function of cardiolipin-containing biological membranes. PMID:17293402

  8. DSC Determination of Glass Transition Temperature on Sea Bass ( Dicentrarchus labrax ) Muscle: Effect of High-Pressure Processing

    Microsoft Academic Search

    Valeria Tironi; Marie de Lamballerie-Anton; Alain Le-Bail

    2009-01-01

    Differential scanning calorimetric determination of glass transition temperature in the freeze-concentrated matrix ($$ T_{\\\\text{g}}^{\\\\text{'}} $$) of sea bass muscle was optimized. Conventional and modulated differential scanning calorimetry (DSC) techniques (using diverse\\u000a cooling\\/heating rate and modulation parameters) and effect of an annealing step (?30, ?20, or ?15°C, 30min) were assayed.\\u000a Transition was more evident using conventional DSC assays, cooling\\/heating rate: 10°C\\/min,

  9. 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/c^2.

  10. 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.

  11. 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.

  12. 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 [Fortis Memorial Research Institute, Gurgaon (India)

    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.

  13. 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. Our results also suggest that shorter chain homologues form L(c) phases that are structurally related to, but more ordered than, those formed by the longer chain homologues, but that these L(c) phases are less ordered than those formed by other phospholipids. These studies also suggest that polar/apolar interfaces of the phosphatidylserine bilayers are more hydrated than those of other glycerolipid bilayers, possibly because of interactions between the polar headgroup and carbonyl groups of the fatty acyl chains. PMID:11023908

  14. 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

  15. CHAPTER XVI TUNICATES AND LANCELETS

    E-print Network

    to the vertebrates and are included with them in the phYlum Chordata to which the higher animals, InclUding man, belong. In modern classifications they are given the rank vf a subphylum of the Chordata. They are

  16. Electromagnetic and calorimetric measurements for AC losses of a YBa2Cu3O7-? coated conductor with Ni-alloy substrate

    NASA Astrophysics Data System (ADS)

    Nguyen, D. N.; Sastry, P. V. P. S. S.; Knoll, D. C.; Schwartz, J.

    2006-10-01

    The AC losses of a rolling-assisted-biaxially-textured-substrate (RABiTS™) processed YBa2Cu3O7-? (YBCO) coated conductor (Goyal et al 1996 Appl. Supercond. 4 403-27) with Ni-alloy substrate and Cu stabilizer were measured at 77 K by both calorimetric (CM) and electromagnetic (EM) methods. In the CM method, improvements in the measurement were observed when a Cernox temperature sensor was used to measure the temperature rise on the sample instead of a differential thermocouple. The effect of heat transferred from current leads was taken into account to improve the accuracy of the CM results. In the EM method, the magnetization losses of the sample in a perpendicular applied field were measured by an in-plane pick-up coil. The calculation of the calibration factor C of the pick-up coil is discussed. Good agreement between AC loss results obtained from the CM and EM methods confirmed the validity of our measurements and calculations.

  17. 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. PMID:23968644

  18. Superconductivity in the misfit compound of (LaSe)1.14(NbSe2): STM/S, calorimetric and magnetization studies

    NASA Astrophysics Data System (ADS)

    Samuely, P.; Szabo, P.; Kacmarcik, J.; Pribulova, Z.; Samuely, T.; Rodrigo, J. G.; Marcenat, C.; Klein, T.; Cario, L.

    2013-03-01

    (LaSe)1.14(NbSe2) is a low temperature superconductor with Tc around 1.2 K belonging to the family of the lamellar chalcogenides. Electron transfer from the LaSe to the NbSe2 slab results in a natural layered system of the insulating LaSe and (super) conducting NbSe2 sheets. In our previous investigations of the anisotropic transport [P. Szabó et al., Phys. Rev. Lett. 86, 5990 (2001)] indications have been found that this system behaves as a stack of Josephson-coupled superconducting NbSe2 sheets separated by insulating LaSe layers. We test this hypothesis by STM/S measurements at subkelvin temperatures and in magnetic fields. Superconducting energy gap obtained by STM opens at the same temperature and field where the interlayer resistivity starts to increase before drop to zero value. Before any conclusions are made homogeneity of the superconducting parameters is to be tested. STM indicates large areas without any gap but calorimetric measurements have shown the bulk superconductivity and magnetization revealed extremely low pinning.

  19. Structural and calorimetric studies of two crystallization stages of Ag10As30S60 glassy alloys

    NASA Astrophysics Data System (ADS)

    Abd-Elrahman, M. I.; Khafagy, Rasha M.; Younis, Noha; Hafiz, M. M.

    2014-09-01

    The structure of the as-prepared and thermal annealed Ag10As30S60 chalcogenide glass is characterized using the X-ray diffraction (XRD) and scanning electron microscopy (SEM). Differential scanning calorimetry (DSC) curves recorded at four different heating rates are analyzed to determine the glass and crystallization transition temperatures, thermal stability and enthalpy release. Two separated crystallization peaks are observed in the DSC curves. XRD results indicate the precipitation of AgAsS4 crystal phase is responsible for the first peak. Numerous phases with S8 dominant phase are accountable for the second peak. The crystallization kinetics such as the activation energy for the crystallization (Ec), the frequency factor (Ko) and the crystallization rate constant K are determined for each crystallization stage. The results show that the crystallization rate constant for the first crystallization stage is about six times larger than that of the second crystallization step.

  20. 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.

  1. Low temperature calorimetric and magnetic studies of copper(II) in 1,4-diazacycloheptane-copper(II) systems

    Microsoft Academic Search

    Gul Dad Khattak; M. Sakhawat Hussain; P. H. Keesom; L. E. Wenger

    1988-01-01

    Low temperature specific heat and magnetic susceptibility studies were carried out on polycrystalline pellets of three copper(II) complexes of 1.4-diazacycloheptane having different geometries. Above 4 K, the specific heat can be described by the relation: C = alphaT3 which allows the determination of Debye temperatures for the investigated systems. Below 4 K, the specific heat rises very fast and goes

  2. A Calorimetric Study of the Influence of Temperature on the Self-Association of Amphiphilic Antidepressant Drugs in Aqueous Solution.

    PubMed

    Attwood; Boitard; Dubès; Tachoire

    2000-07-15

    Relative apparent molar enthalpies have been determined as a function of concentration (0.0001 to 0.2 mol kg(-1)) by heat conduction calorimetry for aqueous solutions of the structurally related antidepressant drugs imipramine and clomipramine in water over the temperature range 288 to 308 K. Critical concentrations determined from inflections in these plots for both drugs had minimum values at 298 K. The concentration dependence of the relative apparent molar enthalpy could be quantitatively described using a mass action model of association based on the Guggenheim equations for the activity coefficients of mixed electrolytes. Derived values of the monomer-counterion interaction coefficient for imipramine became increasingly negative with an increase in temperature over the temperature range 293 to 303 K, indicative of an increasing degree of premicellar association. In contrast, negative monomer-counterion interaction coefficients were obtained for clomipramine at only 303 and 308 K, suggesting an absence of premicellar association at lower temperatures. Values derived for the molar enthalpy of micellization of both drugs from the mass action model indicate an increasingly exothermic process with increase in temperature; positive values at 288 and 293 K arise from hydrophobic interactions while the negative values at higher temperatures suggest the importance of London dispersion interactions as the major driving force for aggregation. Copyright 2000 Academic Press. PMID:10873321

  3. 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.

  4. 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.

  5. Micro-machined calorimetric biosensors

    DOEpatents

    Doktycz, Mitchel J. (Knoxville, TN); Britton, Jr., Charles L. (Alcoa, TN); Smith, Stephen F. (Loudon, TN); Oden, Patrick I. (Plano, TX); Bryan, William L. (Knoxville, TN); Moore, James A. (Powell, TN); Thundat, Thomas G. (Knoxville, TN); Warmack, Robert J. (Knoxville, TN)

    2002-01-01

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

  6. Direct determination of kinetic fragility indices of glassforming liquids by differential scanning calorimetry: Kinetic versus thermodynamic fragilities

    NASA Astrophysics Data System (ADS)

    Wang, Li-Min; Velikov, V.; Angell, C. A.

    2002-12-01

    A calorimetric method of obtaining directly the fragility of liquids from the fictive temperatures of variably quenched glasses, is outlined. "Steepness indexes" m, have been determined for a group of molecular liquids of diverse character, and vary in the range 50-150. The values obtained mostly agree well with those from earlier studies using dielectric relaxation, heat capacity spectroscopy, and viscosity data. In our method there is the advantage that the fragility is determined from the relaxation process that is basic to the calorimetric glass transition temperature measurement, namely, that of the enthalpy. The calorimetric measurements also yield the liquid and glass heat capacities, and entropies of fusion, permitting relationships between thermodynamic and kinetic responses to be examined simultaneously. We study glycerol, dibutylphthallate, 9-bromophenanthrene, salol, orthoterphenyl, propylene carbonate, decalin and its nitrogen derivative decahydroisoquinoline, and find the latter two to be the most fragile liquids known, m =145 and 128 respectively. Surprisingly, of the liquids studied, decalin has the smallest increase in heat capacity at the glass transition. By contrast, the strongest liquid, glycerol, has the largest increase. However, the thermodynamic fragility of decalin, assessed from the scaled rate of increase of the excess entropy above Tg, is found to be high, due to the unusually small value of the excess entropy at Tg. Conversely, the entropy-based fragility for glycerol is the lowest. Thus the correlation of kinetic and entropy-based thermodynamic fragilities reported in recent work is upheld by data from the present study, while the basis for any correlation with the jump in heat capacity itself is removed.

  7. 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).

  8. Introduction There is intense interest in determining the thermody-

    E-print Network

    Loh, Watson

    titration calorimeters, running in the quasi-isothermal mode, has turned titration cal- orimetry) groups C10, C12, C14, and C16, respectively. For both ser- ies, the shapes of the calorimetric titration

  9. 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.

  10. xvi Preface to the second edition Acknowledgments

    E-print Network

    Fitelson, Branden

    Harman, Jaegwon Kim, Christopher Kulp, Jonathan Kvanvig, Bruce Russell, Walter Sinnott-Armstrong, Ernest the anonymous readers for the Press but also Michael Pace, Bruce Russell; Mark Owen Webb, and especially Claudio

  11. XVI Reunio da Sociedade Brasileira de Cristalografia

    E-print Network

    Ferreira, Márcia M. C.

    desenvolvimento de novas metodologias é uma característica de todas as áreas da ciência e, em particular da criação de novas linhas. Pode-se destacar nos últimos dois anos a conclusão e entrada em operação do anel existente e a estruturação de uma nova linha, o aperfeiçoamento

  12. New calorimetric studies of inorganic fluorine compounds. [Silver uranium fluoride, AgUF/sub 6/; cesium fluoroxysulfate, CsSO/sub 4/F

    SciTech Connect

    O'Hare, P.A.G.; Flotow, H.E.; Appleman, E.H.; Malm, J.G.

    1982-04-01

    In this paper, recently determined enthalpies of formation are presented for two fluorides, silver(I) uranium(V) fluoride, AgUF/sub 6/, and cesium fluoroxysulfate, CsSO/sub 4/F. In addition the derivation of entropy is presented for CsSO/sub 4/F.

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

    SciTech Connect

    Somasundaran, P.

    1993-08-31

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

  14. 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.

  15. Characterizing the secondary hydration shell on hydrated myoglobin, hemoglobin, and lysozyme powders by its vitrification behavior on cooling and its calorimetric glass-->liquid transition and crystallization behavior on reheating.

    PubMed Central

    Sartor, G; Hallbrucker, A; Mayer, E

    1995-01-01

    For hydrated metmyoglobin, methemoglobin, and lysozyme powders, the freezable water fraction of between approximately 0.3-0.4 g water/g protein up to approximately 0.7-0.8 g water/g protein has been fully vitrified by cooling at rates up to approximately 1500 K min-1 and the influence of cooling rate characterized by x-ray diffractograms. This vitreous but freezable water fraction started to crystallize at approximately 210 K to cubic ice and at approximately 240 K to hexagonal ice. Measurements by differential scanning calorimetry have shown that this vitreous but freezable water fraction undergoes, on reheating at a rate of 30 K min-1, a glass-->liquid transition with an onset temperature of between approximately 164 and approximately 174 K, with a width of between approximately 9 and approximately 16 degrees and an increase in heat capacity of between approximately 20 and approximately 40 J K-1 (mol of freezable water)-1 but that the glass transition disappears upon crystallization of the freezable water. These calorimetric features are similar to those of water imbibed in the pores of a synthetic hydrogel but very different from those of glassy bulk water. The difference to glassy bulk water's properties is attributed to hydrophilic interaction and H-bonding of the macromolecules' segments with the freezable water fraction, which thereby becomes dynamically modified. Abrupt increase in minimal or critical cooling rate necessary for complete vitrification is observed at approximately 0.7-0.8 g water/g protein, which is attributed to an abrupt increase of water's mobility, and it is remarkably close to the threshold value of water's mobility on a hydrated protein reported by Kimmich et al. (1990, Biophys. J. 58:1183). The hydration level of approximately 0.7-0.8 g water/g protein is approximately that necessary for completing the secondary hydration shell. PMID:8599674

  16. 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

    2008-07-01

    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. PMID:21694377

  17. 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. [Univ. Blaise Pascal/CNRS, Aubiere (France). Lab. de Thermodynamique et Genie Chimique] [Univ. Blaise Pascal/CNRS, Aubiere (France). Lab. de Thermodynamique et Genie Chimique; Mather, A.E. [Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Chemical and Materials Engineering] [Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Chemical and Materials Engineering

    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.

  18. 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

  19. Stochastic determination of matrix determinants

    E-print Network

    Dorn, Sebastian

    2015-01-01

    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. Meanwhile 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, a stochastic estimate for its determinant is still lacking. In this work a probing method for the logarithm of a determinant of a linear operator is introduced. This 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 Bay...

  20. 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

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

    2015-01-01

    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 signi?cant partitioning of Na+, lactic acid, and water into the organic phase, thermodynamically unpredictable pH dependence, and the slow extraction kinetics. In the modi?ed TALSPEAK process, the combination of the aqueous holdback complexant HEDTA (N-(2-hydroxyethyl)ethylenediamine-N,N0,N0-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 ?at 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 modi?ed 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 ?rst 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 proton-ation directly determined by calorimetry. The results of NMR analysis further con?rm that the ?rst two protonation reactions occur on the diamine nitrogen atoms, while the third protonation reaction occurs on the oxygen of a carboxylate group. These data, in conjunction with the thermodynamic parameters of Ln3+/An3+ complexes with HEDTA at different temperatures, will help to predict the speciation and temperature-dependent behavior of Ln3+/An3+ in the modi?ed TALSPEAK process.

  1. Protection of liposomes against fusion during drying by oligosaccharides is not predicted by the calorimetric glass transition temperatures of the dry sugars

    PubMed Central

    Rennecke, Petra; Oliver, Ann E.

    2007-01-01

    Sugars play an important role in the desiccation tolerance of most anhydrobiotic organisms. It has been shown in previous studies that different structural families of oligosaccharides have different efficacies to interact with phospholipid headgroups and protect membranes from solute leakage during drying. Here, we have compared three families of linear oligosaccharides (fructans (inulins), malto-oligosaccharides, manno-oligosaccharides) for their chain-length dependent protection of egg phosphatidylcholine liposomes against membrane fusion. We found increased protection with chain length up to a degree of polymerization (DP) of 5 for malto-oligosaccharides, and a decrease for inulins and manno-oligosaccharides. Differential scanning calorimetry measurements showed that for all sugars the glass transition temperature (Tg) increased with DP, although to different degrees for the different oligosaccharide families. Higher Tg values resulted in reduced membrane fusion only for malto-oligosaccharides below DP5. Contrary to expectation, for inulins, manno-oligosaccharides and malto-oligosaccharides of a DP above five, fusion increased with increasing Tg, indicating that other physical parameters are more important in determining the ability of different sugars to protect membranes against fusion during drying. Further research will be necessary to experimentally define such parameters. PMID:18064448

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

    SciTech Connect

    Somasundaran, P.

    1993-11-30

    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 will also be determined. Solids of relevant mineralogy and a multi-pronged approach consisting of micro & nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability will 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 single surfactant and surfactant mixtures at the kaolinite-water and alumina-water interface were studied during this quarter. The adsorption of sodium dodecyl sulfate (SDS) and octaethylene glycol mono n-decyl ether (C{sub l2}EO{sub 8}) on kaolinite was found to be higher from their mixtures than as single components. This enhanced adsorption was attributed to be due to hydrophobic chain-chain interactions. The effect of pH on the adsorption of single and surfactant mixtures on kaolinite was also elucidated. Desorption of cationic tetradecyl trimethyl ammonium chloride (TTAC) studied at the alumina-water interface indicated that adsorption was reversible. Electrokinetic measurements supported this observation.

  3. 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.

  4. 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.

  5. 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. [Bartlesville Project Office, OK (United States)

    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.

  6. Selectivity of Ni(II) and Zn(II) binding to Sporosarcina pasteurii UreE, a metallochaperone in the urease assembly: a calorimetric and crystallographic study.

    PubMed

    Zambelli, Barbara; Banaszak, Katarzyna; Merloni, Anna; Kiliszek, Agnieszka; Rypniewski, Wojciech; Ciurli, Stefano

    2013-12-01

    Urease is a nickel-dependent enzyme that plays a critical role in the biogeochemical nitrogen cycle by catalyzing the hydrolysis of urea to ammonia and carbamate. This enzyme, initially synthesized in the apo form, needs to be activated by incorporation of two nickel ions into the active site, a process driven by the dimeric metallochaperone UreE. Previous studies reported that this protein can bind different metal ions in vitro, beside the cognate Ni(II). This study explores the metal selectivity and affinity of UreE from Sporosarcina pasteurii (Sp, formerly known as Bacillus pasteurii) for cognate [Ni(II)] and noncognate [Zn(II)] metal ions. In particular, the thermodynamic parameters of SpUreE Ni(II) and Zn(II) binding have been determined using isothermal titration calorimetry. These experiments show that two Ni(II) ions bind to the protein dimer with positive cooperativity. The high-affinity site involves the conserved solvent-exposed His(100) and the C-terminal His(145), whereas the low-affinity site comprises also the C-terminal His(147). Zn(II) binding to the protein, occurring in the same protein regions and with similar affinity as compared to Ni(II), causes metal-driven dimerization of the protein dimer. The crystal structure of the protein obtained in the presence of equimolar amounts of both metal ions indicates that the high-affinity metal binding site binds Ni(II) preferentially over Zn(II). The ability of the protein to select Ni(II) over Zn(II) was confirmed by competition experiments in solution as well as by analysis of X-ray anomalous dispersion data. Overall, the thermodynamics and structural parameters that modulate the metal ion specificity of the different binding sites on the protein surface of SpUreE have been established. PMID:24126709

  7. Calorimetric investigation of copper binding in the N-terminal region of the prion protein at low copper loading: evidence for an entropically favorable first binding event.

    PubMed

    Gogineni, Devi Praneetha; Spuches, Anne M; Burns, Colin S

    2015-01-20

    Although the Cu(2+)-binding sites of the prion protein have been well studied when the protein is fully saturated by Cu(2+), the Cu(2+)-loading mechanism is just beginning to come into view. Because the Cu(2+)-binding modes at low and intermediate Cu(2+) occupancy necessarily represent the highest-affinity binding modes, these are very likely populated under physiological conditions, and it is thus essential to characterize them in order to understand better the biological function of copper-prion interactions. Besides binding-affinity data, almost no other thermodynamic parameters (e.g., ?H and ?S) have been measured, thus leaving undetermined the enthalpic and entropic factors that govern the free energy of Cu(2+) binding to the prion protein. In this study, isothermal titration calorimetry (ITC) was used to quantify the thermodynamic parameters (K, ?G, ?H, and T?S) of Cu(2+) binding to a peptide, PrP(23-28, 57-98), that encompasses the majority of the residues implicated in Cu(2+) binding by full-length PrP. Use of the buffer N-(2-acetomido)-aminoethanesulfonic acid (ACES), which is also a well-characterized Cu(2+) chelator, allowed for the isolation of the two highest affinity binding events. Circular dichroism spectroscopy was used to characterize the different binding modes as a function of added Cu(2+). The Kd values determined by ITC, 7 and 380 nM, are well in line with those reported by others. The first binding event benefits significantly from a positive entropy, whereas the second binding event is enthalpically driven. The thermodynamic values associated with Cu(2+) binding by the A? peptide, which is implicated in Alzheimer's disease, bear striking parallels to those found here for the prion protein. PMID:25541747

  8. TRABALHOS ACEITOS NO XVI SBSR(Para localizar: Ctrl+F) (PAPERS ACCEPTED FOR XVI SBSR)

    E-print Network

    Avaliação da cobertura vegetal por meio dos índices de vegetação SR, NDVI, SAVI e EVI na subbacia do vale índices de vegetação NDVI, SAVI e IAF na caracterização da cobertura vegetativa da região Norte de Minas 79 Identificação das fases de cultivo da canadeaçúcar a partir do perfil temporal de NDVI do sensor

  9. Determining Concentration

    NSDL National Science Digital Library

    AMPS GK-12 Program,

    Students quantify the percent of light reflected from solutions containing varying concentrations of red dye using LEGO© MINDSTORMS© NXT bricks and light sensors. They begin by analyzing a set of standard solutions with known concentrations of food coloring, and plot data to graphically determine the relationship between percent reflected light and dye concentration. Then they identify dye concentrations for two unknown solution samples based on how much light they reflect. Students gain an understanding of light scattering applications and how to determine properties of unknown samples based on a set of standard samples.

  10. Ch. 5 Determinants Determinant functions

    E-print Network

    Choi, Suhyoung

    functions is n-linear. · Definition: D is n-linear. D is alternating if ­ (a) D(A)=0 if two rows a commutative ring with 1. D is a determinant function if D is n- linear, alternating and D(I)=1. (The aim since sum of two 2-linear functions · Alternating. Check (a), (b) above. · This is also unique: #12

  11. 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 transport properties such as electrical conductivity and viscosity may show power-law dependence on composition near and above the percolation threshold of the SiOC network or that of the free-carbon phase. Si(B)CN PDCs with different carbon contents were synthesized by pyrolysis of poly(boro)silylcarbodiimides and poly(boro)silazane precursors and their structure and energetics were studied using multi-nuclear, one- and two- dimensional NMR spectroscopy and oxide melt solution calorimetry. The structure of the polysilylcarbodiimide-derived SiCN PDCs at lower carbon content and pyrolysis temperatures (800 oC) consists of amorphous nanodomains of sp2 carbon and silicon nitride with an interfacial bonding between N, C and Si atoms that is stabilized by the presence of hydrogen. The interfacial Si-C and N-C bonds are destroyed with concomitant hydrogen loss upon increasing the pyrolysis temperature to 1100 oC. Calorimetry results demonstrate that the mixed bonding in the interfacial regions play a key role in the thermodynamic stabilization of these PDCs. The size of the carbon domains increases with increasing carbon content until a continuous amorphous carbon matrix is formed with 55-60 wt % C. The polyborosilylcarbodiimide-derived SiBCN ceramics contain carbon and silicon nitride nanodomains with the BN domains being present predominantly at the interface. In contrast, the structure of the polyborosilazane-derived ceramics consists of significant amount of mixed bonding in the nearest-neighbor coordination environments of Si and B atoms leading to the formation of SiC xN4-x tetrahedral units and BCN2 triangular units. The interfacial region between the SiCN and C nanodomains is occupied by the BCN phase. These results demonstrate that the chemistry of the polymeric precursors exerts major influence on the microstructure and bonding in their derived ceramics.

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

    SciTech Connect

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

    1991-10-01

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

  13. Experimental determination of the third derivative of G. I. Enthalpic interaction

    NASA Astrophysics Data System (ADS)

    Westh, Peter; Inaba, Akira; Koga, Yoshikata

    2008-12-01

    The solute (i)—solute interaction in terms of enthalpy, Hi-iE=N(?2HE/?ni2)=(1-xi)(?2HE/?ni?xi), the third derivative of G, was experimentally determined using a Thermal Activity Monitor isothermal titration calorimeter for aqueous solutions of 2-butoxyethanol (BE) and 1-propanol (1P). This was done using both calorimetric reference and sample vessels actively. We simultaneously titrate small and exactly equal amounts of solute i (=BE or 1P) into both cells which contain the binary mixtures at an average mole fraction, xi, which differs by a small amount ?xi. The appropriate amount of titrant ?ni was chosen so that the quotient (?HE/?ni) can be approximated as (?HE/?ni), and so that the scatter of the results is reasonable. ?HE is the thermal response from an individual cell on titration, and we measure directly the difference in the thermal response between the two cells, ?(?HE). The resulting quotient, ?(?HE)/?ni/?xi, can be approximated as (?2HE/?ni?xi) and hence provides a direct experimental avenue for the enthalpy interaction function. We varied the value of ?xi to seek its appropriate size. Since HE contains the first derivative of G with respect to T, the result is the third derivative quantity. Thus we present here a third derivative quantity directly determined experimentally for the first time.

  14. Childhood disability determination for supplemental security income: Implementing the Zebley decision

    Microsoft Academic Search

    Jeffrey B. Schwamm

    1996-01-01

    The United States Supreme Court issued a landmark decision in 1990 in Sullivan v. Zebley, invalidating the Social Security Administration's (SSA) regulations governing adjudication of Supplemental Security Income (SSI) childhood disability claims under Title XVI of the Social Security Act. This article briefly describes the Zebley decision. Allowances and denials of SSI childhood disability claims are presented by state and

  15. 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-2) corresponds to the detection limit for adsorption of less than 1.5 × 1012 CO molecules cm-2 or less than 0.1% of the monolayer coverage (with respect to the 1.5 × 1015 surface Pt atoms cm-2). The absolute accuracy in energy is within ˜7%-9%. As a test of the new calorimeter, the adsorption heats of CO on Pt(111) at different temperatures were measured and compared to previously obtained calorimetric data at 300 K.

  16. 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…

  17. Stereotactic Radiosurgery XVI: A Treatment for Previously Irradiated Pituitary Adenomas

    Microsoft Academic Search

    F. M. Swords; C. A. ALLAN; P. N. PLOWMAN; A. SIBTAIN; J. EVANSON; S. L. CHEW; A. B. GROSSMAN; G. M. BESSER; J. P. MONSON

    2003-01-01

    We report the use of stereotactic radiosurgery delivered through an adapted linear accelerator (stereotactic multiple arc radiation therapy (SMART)) for pituitary adenomas not cured by conventional therapy. All 21 patients had undergone conventional radiotherapy (45-50 Gy); 18 had also undergone prior surgery. This cohort comprised 13 patients with somato- trope adenomas, four with corticotrope adenomas, one with a lactotrope adenoma,

  18. O PRÍNCIPE PROPOSTO POR NICOLAU MAQUIAVEL NO SÉCULO XVI

    Microsoft Academic Search

    Marcia Aparecida; Lopes Benassi

    The present communication has the purpose of making some considerations about the political thought of the Italian Niccolo Machiavelli, author who lived between the 15th and 16th centuries, a period of rapid decomposition of the feudal order and also of fights for the construction of the modern institutions. Differently from countries like France and Spain, for example, that at this

  19. Planck early results. XVI. The Planck view of nearby galaxies

    Microsoft Academic Search

    P. A. R. Ade; N. Aghanim; M. Arnaud; M. Ashdown; J. Aumont; C. Baccigalupi; A. Balbi; A. J. Banday; R. B. Barreiro; J. G. Bartlett; E. Battaner; K. Benabed; A. Benoît; J.-P. Bernard; M. Bersanelli; R. Bhatia; J. J. Bock; A. Bonaldi; J. R. Bond; J. Borrill; M. Bucher; C. Burigana; P. Cabella; J.-F. Cardoso; A. Catalano; L. Cayón; A. Challinor; A. Chamballu; R.-R. Chary; L.-Y. Chiang; P. R. Christensen; D. L. Clements; S. Colombi; F. Couchot; A. Coulais; B. P. Crill; F. Cuttaia; L. Danese; R. D. Davies; R. J. Davis; P. de Bernardis; G. de Gasperis; A. de Rosa; G. de Zotti; J. Delabrouille; J.-M. Delouis; F.-X. Désert; C. Dickinson; H. Dole; S. Donzelli; O. Doré; U. Dörl; M. Douspis; X. Dupac; G. Efstathiou; T. A. Enßlin; F. Finelli; O. Forni; M. Frailis; E. Franceschi; S. Galeotta; K. Ganga; M. Giard; G. Giardino; Y. Giraud-Héraud; J. González-Nuevo; K. M. Górski; S. Gratton; A. Gregorio; A. Gruppuso; F. K. Hansen; D. Harrison; G. Helou; S. Henrot-Versillé; D. Herranz; S. R. Hildebrandt; E. Hivon; M. Hobson; W. A. Holmes; W. Hovest; R. J. Hoyland; K. M. Huffenberger; A. H. Jaffe; W. C. Jones; M. Juvela; E. Keihänen; R. Keskitalo; T. S. Kisner; R. Kneissl; L. Knox; H. Kurki-Suonio; G. Lagache; A. Lähteenmäki; J.-M. Lamarre; A. Lasenby; R. J. Laureijs; C. R. Lawrence; S. Leach; R. Leonardi; M. Linden-Vørnle; M. López-Caniego; P. M. Lubin; J. F. Macías-Pérez; C. J. MacTavish; S. Madden; B. Maffei; D. Maino; N. Mandolesi; R. Mann; M. Maris; E. Martínez-González; S. Masi; S. Matarrese; F. Matthai; P. Mazzotta; A. Melchiorri; L. Mendes; A. Mennella; M.-A. Miville-Deschênes; A. Moneti; L. Montier; G. Morgante; D. Mortlock; D. Munshi; A. Murphy; P. Naselsky; P. Natoli; C. B. Netterfield; H. U. Nørgaard-Nielsen; F. Noviello; D. Novikov; I. Novikov; S. Osborne; F. Pajot; B. Partridge; F. Pasian; G. Patanchon; M. Peel; O. Perdereau; L. Perotto; F. Perrotta; F. Piacentini; M. Piat; S. Plaszczynski; E. Pointecouteau; G. Polenta; N. Ponthieu; T. Poutanen; G. Prézeau; S. Prunet; J.-L. Puget; W. T. Reach; R. Rebolo; M. Reinecke; C. Renault; S. Ricciardi; T. Riller; I. Ristorcelli; G. Rocha; C. Rosset; M. Rowan-Robinson; J. A. Rubiño-Martín; B. Rusholme; M. Sandri; G. Savini; D. Scott; M. D. Seiffert; P. Shellard; G. F. Smoot; J.-L. Starck; F. Stivoli; V. Stolyarov; R. Sudiwala; J.-F. Sygnet; J. A. Tauber; L. Terenzi; L. Toffolatti; M. Tomasi; J.-P. Torre; M. Tristram; J. Tuovinen; M. Türler; G. Umana; L. Valenziano; J. Varis; P. Vielva; F. Villa; N. Vittorio; L. A. Wade; B. D. Wandelt; D. Yvon; A. Zacchei; A. Zonca

    2011-01-01

    The all-sky coverage of the Planck Early Release Compact Source Catalogue (ERCSC) provides an unsurpassed survey of galaxies at submillimetre (submm) wavelengths, representing a major improvement in the numbers of galaxies detected, as well as the range of far-IR\\/submm wavelengths over which they have been observed. We here present the first results on the properties of nearby galaxies using these

  20. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...of both student and program needs. Each activity program shall help develop leadership...student participation but not be limited to activities that include special interest clubs, physical activities, student government, and cultural...

  1. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...of both student and program needs. Each activity program shall help develop leadership...student participation but not be limited to activities that include special interest clubs, physical activities, student government, and cultural...

  2. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...of both student and program needs. Each activity program shall help develop leadership...student participation but not be limited to activities that include special interest clubs, physical activities, student government, and cultural...

  3. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...of both student and program needs. Each activity program shall help develop leadership...student participation but not be limited to activities that include special interest clubs, physical activities, student government, and cultural...

  4. 25 CFR 36.43 - Standard XVI-Student activities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...of both student and program needs. Each activity program shall help develop leadership...student participation but not be limited to activities that include special interest clubs, physical activities, student government, and cultural...

  5. ANO XVI -EDIO 123 -ABRIL DE 2014 Ato em Joinville

    E-print Network

    Floeter, Sergio Ricardo

    nossas lutas para promover as mu- danças necessárias. Nesta edição do Jornal Circulação você confe- re o participando das lutas para que todos nós possamos construir um país melhor e uma sociedade mais justa valo

  6. Physical studies of asteroids XVI - Photoelectric photometry of 17 asteroids

    NASA Astrophysics Data System (ADS)

    Lagerkvist, C.-I.; Hahn, G.; Magnusson, P.; Rickman, H.

    1987-07-01

    The authors present photoelectric photometry of 17 asteroids observed during the period 1979 - 1986. Composite lightcurves have been derived for 76, 236, 439, 516 and 591, and at least a reasonable single-lightcurve coverage has been obtained for the majority of the remaining ones. Reference is made to Tholen's (1984) taxonomic classification and a brief discussion of lightcurve statistics in this framework is given. Differences between the spin rates and amplitudes of the C, S and M classes are considered and previous conclusions regarding the peculiar characteristics of M asteroids are confirmed. An indication is found that C and S asteroids have a particularly slow spin when situated near the 3/1 or 5/2 Kirkwood gaps.

  7. Experimental determination of the third derivative of G. I. enthalpic interaction.

    PubMed

    Westh, Peter; Inaba, Akira; Koga, Yoshikata

    2008-12-01

    The solute (i)-solute interaction in terms of enthalpy, H(i-i) (E)=N( partial differential(2)H(E)/ partial differentialn(i) (2))=(1-x(i))( partial differential(2)H(E)/ partial differentialn(i) partial differentialx(i)), the third derivative of G, was experimentally determined using a Thermal Activity Monitor isothermal titration calorimeter for aqueous solutions of 2-butoxyethanol (BE) and 1-propanol (1P). This was done using both calorimetric reference and sample vessels actively. We simultaneously titrate small and exactly equal amounts of solute i (=BE or 1P) into both cells which contain the binary mixtures at an average mole fraction, x(i), which differs by a small amount Deltax(i). The appropriate amount of titrant deltan(i) was chosen so that the quotient (deltaH(E)/deltan(i)) can be approximated as ( partial differentialH(E)/ partial differentialn(i)), and so that the scatter of the results is reasonable. deltaH(E) is the thermal response from an individual cell on titration, and we measure directly the difference in the thermal response between the two cells, Delta(deltaH(E)). The resulting quotient, Delta(deltaH(E))/deltan(i)/Deltax(i), can be approximated as ( partial differential(2)H(E)/ partial differentialn(i) partial differentialx(i)) and hence provides a direct experimental avenue for the enthalpy interaction function. We varied the value of Deltax(i) to seek its appropriate size. Since H(E) contains the first derivative of G with respect to T, the result is the third derivative quantity. Thus we present here a third derivative quantity directly determined experimentally for the first time. PMID:19063537

  8. 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.

  9. Calorimetric and spectroscopic study of quasi-one-dimensional Haldane magnets (Y{sub 1-x}Nd{sub x}){sub 2}BaNiO{sub 5} (x = 1, 0.75, 0.50, 0.25)

    SciTech Connect

    Popova, E. A., E-mail: eapopova@yahoo.co [Moscow State Institute of Electronics and Mathematics (Technical University) (Russian Federation); Vasil'ev, A. N. [Moscow State University, Department of Physics (Russian Federation); Klimin, S. A. [Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation); Narozhnyi, M. V.; Popova, M. N., E-mail: popova@isan.troitsk.r [Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation)

    2010-08-15

    The temperature dependences of the heat capacity and optical transmission spectra of quasi-one-dimensional Haldane magnets (Y{sub 1-x}Nd{sub x}){sub 2}BaNiO{sub 5} (x = 1, 0.75, 0.50, 0.25) have been studied. All the compounds studied undergoes antiferromagnetic ordering. In the ordered state, the internal magnetic field produces splitting of the ground-state Kramers doublet of Nd{sup 3+} ion. The temperature dependences of the magnitude of splitting, as determined from spectroscopic data, were used to calculate the Schottky anomaly on the heat capacity curve. Nonequivalent centers related to neodymium ions have been found in compounds with x = 0.75, 0.50, and 0.25.

  10. Crystal structure determination of new antimitotic agent bis(p-fluorobenzyl)trisulfide.

    PubMed

    An, Haoyun; Hu, Xiurong; Gu, Jianming; Chen, Linshen; Xu, Weiming; Mo, Xiaopeng; Xu, Wanhong; Wang, Xiaobo; Xu, Xiao

    2008-01-01

    The purpose of this research was to investigate the physical characteristics and crystalline structure of bis(p-fluorobenzyl)trisulfide, a new anti-tumor agent. Methods used included X-ray single crystal diffraction, X-ray powder diffraction (XRPD), Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetric (DSC) and thermogravimetric (TG) analyses. The findings obtained with X-ray single crystal diffraction showed that a monoclinic unit cell was a = 12.266(1) A, b = 4.7757(4) A, c = 25.510(1) A, beta = 104.25(1) degrees ; cell volume = 1,448.4(2) A(3), Z = 4, and space group C2/c. The XRPD studies of the four crystalline samples, obtained by recrystallization from four different solvents, indicated that they had the same diffraction patterns. The diffraction pattern stimulated from the crystal structure data is in excellent agreement with the experimental results. In addition, the identical FT-IR spectra of the four crystalline samples revealed absorption bands corresponding to S-S and C-S stretching as well as the characteristic aromatic substitution. Five percent weight loss at 163.3 degrees C was observed when TG was used to study the decomposition process in the temperature range of 20-200 degrees C. DSC also allowed for the determination of onset temperatures at 60.4(1)-60.7(3) degrees C and peak temperatures at 62.1(3)-62.4(3) degrees C for the four crystalline samples studied. The results verified that the single crystal structure shared the same crystal form with the four crystalline samples investigated. PMID:18431647

  11. Short arcs at low current determination of the power lost by conduction into anode

    SciTech Connect

    Abbaoui, M.; Salihou, H. [Universite Blaise Pascal, Aubiere (France)

    1995-12-31

    The mechanisms occurring at the anode of an electric arc are less important compared to that at the cathode, Many studies have been carried out to get a better understanding of anode phenomena in welding, but few of them have been reported on sham am in gases then last years. In general, for short arcs, the major problem encouraged in experiment was the instability of the arc voltage. This instability depends on the phenomena associated with the existence of the arc, the erosion, the nature and surface state of the electrode materials mainly for low currents arcs. Thus, for short arcs operating in gases at low current, experimental investigations are complicated because of their inherent instability and the metal gas interaction. Moreover, because of this instability, there are less data available. In this paper, we are concerned with low arc current (2-5A) and small electrode separation (0.4-1mm). For short arcs in gases at low-current, it is known from literature that one of the important tool is the energy balance which enables to deal with the power lost by conduction into electrodes and the current density. Calorimetric observations show that about 80% of the electrical power input is lost into both electrodes mainly by conduction. In the following analysis, a simple method of determining the power lost by conduction into different anode materials using a wall stabilised arc is presented. The experimental method consists in measuring the temperature reached in steady state at different points distributed along the electrode axis, fitting the values obtained and calculating the power supplied P{sub cd} to the anode surface facing the column.

  12. 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.

  13. EMPOWERING DIGITAL SELF DETERMINATION

    E-print Network

    Das, Rhiju

    : Communication and Digital Media 2. Data Context and Digital Personas 3. Personal Data: Use, ReuseEMPOWERING DIGITAL SELF DETERMINATION Symposium Summary Stanford University, Summer 2012 #12;#12;EMPOWERING DIGITAL SELF DETERMINATION Symposium, Stanford University, CA Summer, 2012 210 Panama Street

  14. COLORIMETRIC DETERMINATION OF MANGANESE

    E-print Network

    Bertsch George F.

    1 COLORIMETRIC DETERMINATION OF MANGANESE (Chemistry 51 Version) The objective of this experiment is to determine the percentage of manganese in a steel sample, using colorimetric methods of analysis. PRINCIPLES This analysis is accomplished by dissolving the steel sample, converting all of the manganese to the intensely

  15. Determinism without causality

    NASA Astrophysics Data System (ADS)

    D?Ariano, G. M.; Manessi, F.; Perinotti, P.

    2014-12-01

    Causality has often been confused with the notion of determinism. It is mandatory to separate the two notions in view of the debate about quantum foundations. Quantum theory provides an example of causal non-deterministic theory. Here we introduce a toy operational theory that is deterministic and non-causal, thus proving that the two notions of causality and determinism are totally independent.

  16. 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 into multiple containers. A single item from that batch is then selected for both neutron and calorimetric measurements; all remaining items undergo a neutron measurement only. Using the technique mentioned above, the 'true' {alpha} value determined from the first (calorimeter and passive neutron measured) item is used in multiplicity analysis for all other items in the batch. The justification for using this {alpha} value in subsequent calculations is the assumption that the chemical composition and isotopic distribution of all batch items are the same, giving a constant ({alpha},n):spontaneous fission ratio. This analysis method has been successfully applied to the KIS Facility, significantly improving measurement uncertainties and reducing processing times for numerous items. Comprehensive plans were later developed to extend the use of this method to other applications, including the K-Area Shuffler and the H-Area Pu-Blending Project. While only the feasibility study for the Shuffler has been completed, implementation of the method in the H-Area Pu-Blending Project is currently in progress and has been successfully applied to multiple items. This report serves to document the details of this method in order to serve as a reference for future applications. Also contained herein are specific examples of the application of known-{alpha} multiplicity analysis.

  17. Determinants of nucleosome positioning

    PubMed Central

    Struhl, Kevin; Segal, Eran

    2013-01-01

    Nucleosome positioning is critical for gene expression and most DNA-related processes. Here, we review the dominant patterns of nucleosome positioning that have been observed, and summarize current understanding of their underlying determinants. The genome-wide pattern of nucleosome positioning is determined by the combination of DNA sequence, ATP-dependent nucleosome remodeling enzymes, and transcription factors including activators, components of the preinitiation complex, and elongating RNA polymerase II. These determinants influence each other such that the resulting nucleosome positioning patterns are likely to differ among genes and among cells within a population, with consequent effects on gene expression. PMID:23463311

  18. Temperature determination using pyrometry

    DOEpatents

    Breiland, William G. (Albuquerque, NM); Gurary, Alexander I. (Bridgewater, NJ); Boguslavskiy, Vadim (Princeton, NJ)

    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.

  19. Determining Pregnancy in Cattle

    E-print Network

    Beverly, John R.; Sprott, L. R.; Carpenter, Bruce B.

    2008-12-16

    The process of palpating to determine pregnancy in cattle and the equipment used during palpation are described and illustrated in this bulletin. The female reproductive system is discussed, along with the developmental stages of the embryo/fetus....

  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. 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.

  2. Calorimetric analysis of cryopreservation and freeze-drying formulations.

    PubMed

    Sun, Wendell Q

    2015-01-01

    Differential scanning calorimetry (DSC) is a commonly used thermal analysis technique in cryopreservation and freeze-drying research. It has been used to investigate crystallization, eutectic formation, glass transition, devitrification, recrystallization, melting, polymorphism, molecular relaxation, phase separation, water transport, thermochemistry, and kinetics of complex reactions (e.g., protein denaturation). Such information can be used for the optimization of protective formulations and process protocols. This chapter gives an introduction to beginners who are less familiar with this technique. It covers the instrument and its basic principles, followed by a discussion of the methods as well as examples of specific applications. PMID:25428006

  3. Calorimetric and Binding Dissections of HSA Upon Interaction with Bilirubin

    Microsoft Academic Search

    Z. Moosavi-Movahedi; S. Safarian; M. Zahedi; M. Sadeghi; A. A. Saboury; J. Chamani; H. Bahrami; A. Ashraf-Modarres; A. A. Moosavi-Movahedi

    2006-01-01

    The interactions between bilirubin and human serum albumin (HSA) were studied by isothermal titration calorimetry (ITC) and UV–vis spectrophotometry at 27°C in 100 mM phosphate buffer pH 7.4 containing 1 mM EDTA. The biphasic shape of the HSA–bilirubin binding curve depicted the existence of two bilirubin binding sets on the HSA structure which had distinct binding interactions. Each binding set contained one or

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

    Microsoft Academic Search

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

    2011-01-01

    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

  5. Calorimetric glass transition in a mean field theory approach

    E-print Network

    Manuel Sebastian Mariani; Giorgio Parisi; Corrado Rainone

    2014-11-04

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

  6. Hydration effects of deoxyadenosine: A differential calorimetric study

    NASA Astrophysics Data System (ADS)

    Cooper, Robert; Lee, S. A.; Griffey, R. H.; Mohan, V.

    2000-03-01

    The water of hydration is an integral part of the double helical structure of DNA. In order to understand the interactions between water and DNA, we have studied the hydration of the nucleoside deoxyadenosine as a function of relative humidity. Differential scanning calorimetry was used to measure the enthalpy and activation energy of dehydration. These data will be contrasted with the results obtained from guanosine and deoxyguanosine.

  7. Calorimetric studies of small-molecule adsorption to carbon nanotubes

    E-print Network

    Glab, Kristin Lena

    2009-01-01

    Isothermal titration calorimetry (ITC) was developed as a technique for qualitatively comparing the heat of absorption of small molecules to single-walled carbon nanotubes (SWCNTs). In agreement with other studies, it was ...

  8. RIS-M-2247 A CALORIMETRIC THERMAL NEUTRON DOSEMETER

    E-print Network

    . The thermal flux density pattern in the irradiation facilities of a research reactor is subject to slow neutron dose. In the 5 silicon irradiation rigs in the DR 3 reactor thermal neutron dosemeters applying characteristics of the silicon material. The most convenient arrangement seen from a practical point of view

  9. Differential scanning calorimetric studies of irradiated drawn high density polyethylene

    NASA Astrophysics Data System (ADS)

    Liu, Zhan-Jun; Markovi?, V.; Silverman, Joseph

    The endotherms of vacuum-irradiated drawn high density polyethylene samples are presented along with the heats of fusion and melting temperatures associated with the first and second melting. Also presented are the shrinkage curves at elevated temperatures. Following are the principal observations and conclusions: (1) For the unirradiated drawn HDPE samples, thickening or reorganization of the long period fibrous material takes place during the DSC measurement. Thus, the sharp unimodal endotherms with high melting points observed for these samples are not truly representative of the actual endotherms. (2) With the vacuum-irradiated drawn HDPE samples, multiple peaks are observed and the melting temperature associated with the main peak is lower; also the endotherms are much broader than those of the unirradiated samples. Because radiation-induced crosslinking inhibits recrystallization following melting, the observed endotherms for the irradiated samples are more exact representations of the actual endotherms of the unirradiated drawn HDPE. These results lead to new information about the microscopic fibrous structure of drawn HDPE.

  10. Thermal decomposition of hydroxylamine: isoperibolic calorimetric measurements at different conditions.

    PubMed

    Adamopoulou, Theodora; Papadaki, Maria I; Kounalakis, Manolis; Vazquez-Carreto, Victor; Pineda-Solano, Alba; Wang, Qingsheng; Mannan, M Sam

    2013-06-15

    Thermal decomposition of hydroxylamine, NH2OH, was responsible for two serious accidents. However, its reactive behavior and the synergy of factors affecting its decomposition are not being understood. In this work, the global enthalpy of hydroxylamine decomposition has been measured in the temperature range of 130-150 °C employing isoperibolic calorimetry. Measurements were performed in a metal reactor, employing 30-80 ml solutions containing 1.4-20 g of pure hydroxylamine (2.8-40 g of the supplied reagent). The measurements showed that increased concentration or temperature, results in higher global enthalpies of reaction per unit mass of reactant. At 150 °C, specific enthalpies as high as 8 kJ per gram of hydroxylamine were measured, although in general they were in the range of 3-5 kJ g(-1). The accurate measurement of the generated heat was proven to be a cumbersome task as (a) it is difficult to identify the end of decomposition, which after a fast initial stage, proceeds very slowly, especially at lower temperatures and (b) the environment of gases affects the reaction rate. PMID:23644689

  11. 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.

  12. Application of porous Si micromachining technology in the calorimetric sensor

    NASA Astrophysics Data System (ADS)

    Lai, Zongsheng; Wan, Xinjun; Zhou, Pingsong; Wang, Yunzhen

    1996-09-01

    Using porous silicon as a sacrificial layer with a large distance from the structure to the substrate, the porous Si micromachining is a new generation surface micromachining technology. A sketch of the special self-made 3-cavity electrochemical device used for anodisation and a detailed description of the porous film formation parameters were given int his paper. Anodisation is performed with current density 40 mA/cm2 for 60 minutes. Formation parameters and amounts of several major impurities of porous-Si layer are studied. The porous-Si layer was removed in 1 percent KOH and then the flow channel with depth of 50 micrometers was formed. A 0.2 micrometers Ni-Cr thin film was deposited and patterned on the Si3N4+ poly-Si microbridge as a thermistor. The analysis model was introduced and met quite well with the experiment. The results of the fast response and low power dissipation are reported in this paper.

  13. Calorimetric measurements of a Yang-Koldamasov device

    E-print Network

    Novosad, Jennifer

    2007-01-01

    Due to the finite supply of oil, energy availability and price are issues facing the world. Among the possible approaches to this problem is research of new physical effects which may produce energy in novel ways. The ...

  14. 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.

  15. 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.

  16. 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.

  17. Polarographic determination of phosphorus.

    PubMed

    Pardo, R; Barrado, E; Castrillejo, Y; Batanero, P S

    1983-09-01

    A method has been developed for the determination of phosphorus, as phosphate, by means of the catalytic polarographic wave for the reduction of hydrogen peroxide in the presence of Mo(VI). This reduction is combined with the previous formation and extraction of 12-molybdophosphoric acid. Depending on the extractant chosen, ethyl acetate or methyl isobutyl ketone, the determination limit is 2.3 or 3.1 mug l . respectively. The procedure has been applied to certified steel samples with good results. PMID:18963439

  18. Determining Glassware Accuracy

    NSDL National Science Digital Library

    The North Carolina Community College System BioNetwork's interactive eLearning tools (IETs) are reusable chunks of training that can be deployed in a variety of courses or training programs. IETs are designed to enhance, not replace hands-on training. Learners are able to enter a hands-on lab experience better prepared and more confident. This particular IET delves into determining glassware accuracy in the lab. Accompanied by a video, this interactive module walks students through determining the most accurate piece of glassware by calculating the standard deviation and percent of error for each.

  19. Gender determination in populus

    SciTech Connect

    McLetchie, D.N. [Univ. of Kentucky, Lexington, KY (United States). Dept. of Biological Sciences; Tuskan, G.A. [Oak Ridge National Lab., TN (United States)

    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.

  20. Determinants of superstition

    Microsoft Academic Search

    Benno Torgler

    2007-01-01

    Although superstition is a common phenomenon in our modern society, only a few studies have explored empirically on what it depends. This paper investigates the factors which determine superstition, reporting some preliminary empirical results. The findings indicate that socio-demographic and socio-economic conditions matter. There seems to be a certain concurrence between churches and superstitious beliefs, the correlation between superstition and

  1. 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)

  2. Determining Haugh Units

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. 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).

  4. 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.

  5. Determining the Hubble Constant

    NSDL National Science Digital Library

    Cush Copeland

    2012-07-11

    Students will graph distance/velocity data of real galaxies to arrive at their own value of the Hubble constant (H). Once they have calculated their own value of H, they will use it to determine distances to real galaxies with known recessional velocities.

  6. Anemia: determining the cause.

    PubMed

    Fleischman, Wendy

    2012-06-01

    Anemia is a common finding in small animal practice; however, the multitude of potential causes can make determining the underlying diagnosis a challenging and frustrating endeavor. With a basic understanding of red blood cell production and a systematic diagnostic approach, clinicians should be able to clearly define the cause of anemia in most cases. PMID:22692674

  7. Dietary determinants of obesity

    Microsoft Academic Search

    D. U. Huaidong; E. J. M. Feskens

    2010-01-01

    Obesity has become a serious public health problem worldwide, and dietary composition can play a role in its prevention and treatment. However, available literature on the impacts of different dietary factors on weight change is inconsistent, or even conflicting. In this review, we briefly summarized the mechanisms and influences of several major dietary determinants of weight change, with a focus

  8. Waste Determination Equivalency - 12172

    SciTech Connect

    Freeman, Rebecca D. [Savannah River Remediation (United States)

    2012-07-01

    The Savannah River Site (SRS) is a Department of Energy (DOE) facility encompassing approximately 800 square kilometers near Aiken, South Carolina which began operations in the 1950's with the mission to produce nuclear materials. The SRS contains fifty-one tanks (2 stabilized, 49 yet to be closed) distributed between two liquid radioactive waste storage facilities at SRS containing carbon steel underground tanks with storage capacities ranging from 2,800,000 to 4,900,000 liters. Treatment of the liquid waste from these tanks is essential both to closing older tanks and to maintaining space needed to treat the waste that is eventually vitrified or disposed of onsite. Section 3116 of the Ronald W. Reagan National Defense Authorization Act of Fiscal Year 2005 (NDAA) provides the Secretary of Energy, in consultation with the Nuclear Regulatory Commission (NRC), a methodology to determine that certain waste resulting from prior reprocessing of spent nuclear fuel are not high-level radioactive waste if it can be demonstrated that the waste meets the criteria set forth in Section 3116(a) of the NDAA. The Secretary of Energy, in consultation with the NRC, signed a determination in January 2006, pursuant to Section 3116(a) of the NDAA, for salt waste disposal at the SRS Saltstone Disposal Facility. This determination is based, in part, on the Basis for Section 3116 Determination for Salt Waste Disposal at the Savannah River Site and supporting references, a document that describes the planned methods of liquid waste treatment and the resulting waste streams. The document provides descriptions of the proposed methods for processing salt waste, dividing them into 'Interim Salt Processing' and later processing through the Salt Waste Processing Facility (SWPF). Interim Salt Processing is separated into Deliquification, Dissolution, and Adjustment (DDA) and Actinide Removal Process/Caustic Side Solvent Extraction Unit (ARP/MCU). The Waste Determination was signed by the Secretary of Energy in January of 2006 based on proposed processing techniques with the expectation that it could be revised as new processing capabilities became viable. Once signed, however, it became evident that any changes would require lengthy review and another determination signed by the Secretary of Energy. With the maturation of additional salt removal technologies and the extension of the SWPF start-up date, it becomes necessary to define 'equivalency' to the processes laid out in the original determination. For the purposes of SRS, any waste not processed through Interim Salt Processing must be processed through SWPF or an equivalent process, and therefore a clear statement of the requirements for a process to be equivalent to SWPF becomes necessary. (authors)

  9. Determining proxy consent.

    PubMed

    O'Neil, R

    1983-11-01

    The paper clarifies the relative merits and proper roles of standards of review in the determination of proxy consent for those unable to make decisions concerning their own medical treatment. The "substituted judgment" standard asks which treatment the incompetent person would choose if competent, while the "best interests" test asks which treatment would benefit the patient. The tests are discussed in relation to the moral principles of autonomy and beneficence which provide their justification. I distinguish six types of cases involving incompetent patients and argue that which standard is appropriate depends on the type of case involved. A "rational choice" standard, which asks "What would the incompetent patient choose if his or her choice were rational?", is proposed as a way of determining best interests. PMID:6655387

  10. REDUCED PROTECTIVE CLOTHING DETERMINATIONS

    SciTech Connect

    BROWN, R.L.

    2003-06-13

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

  11. Determining Sigma - Lambda mixing

    E-print Network

    R. Horsley; J. Najjar; Y. Nakamura; H. Perlt; D. Pleiter; P. E. L. Rakow; G. Schierholz; A. Schiller; H. Stüben; J. M. Zanotti

    2014-12-02

    SU2 isospin breaking effects in baryon octet (and decuplet) masses are due to a combination of up and down quark mass differences and electromagnetic effects. These mass differences are small. Between the Sigma and Lambda the mass splitting is much larger, but this is mostly due to their different wavefunctions. However there is now also mixing between these states. We determine the QCD mixing matrix and hence find the mixing angle and mass splitting.

  12. Gender determination using cheiloscopy

    PubMed Central

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

    2013-01-01

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

  13. 20 CFR 404.1575 - Evaluation guides if you are self-employed.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial Gainful Activity § 404.1575 Evaluation...supplemental security income payments based on disability or blindness under title XVI of the Social Security Act, months for...

  14. 20 CFR 404.1575 - Evaluation guides if you are self-employed.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial Gainful Activity § 404.1575 Evaluation...supplemental security income payments based on disability or blindness under title XVI of the Social Security Act, months for...

  15. 20 CFR 404.1575 - Evaluation guides if you are self-employed.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial Gainful Activity § 404.1575 Evaluation...supplemental security income payments based on disability or blindness under title XVI of the Social Security Act, months for...

  16. 20 CFR 404.1574 - Evaluation guides if you are an employee.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial Gainful Activity § 404.1574 Evaluation...supplemental security income payments based on disability or blindness under title XVI of the Social Security Act, months for...

  17. 20 CFR 404.1574 - Evaluation guides if you are an employee.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial Gainful Activity § 404.1574 Evaluation...supplemental security income payments based on disability or blindness under title XVI of the Social Security Act, months for...

  18. 20 CFR 404.1574 - Evaluation guides if you are an employee.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial Gainful Activity § 404.1574 Evaluation...supplemental security income payments based on disability or blindness under title XVI of the Social Security Act, months for...

  19. 20 CFR 404.1574 - Evaluation guides if you are an employee.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial Gainful Activity § 404.1574 Evaluation...supplemental security income payments based on disability or blindness under title XVI of the Social Security Act, months for...

  20. 20 CFR 404.1574 - Evaluation guides if you are an employee.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial Gainful Activity § 404.1574 Evaluation...supplemental security income payments based on disability or blindness under title XVI of the Social Security Act, months for...

  1. 20 CFR 404.1575 - Evaluation guides if you are self-employed.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial Gainful Activity § 404.1575 Evaluation...supplemental security income payments based on disability or blindness under title XVI of the Social Security Act, months for...

  2. 20 CFR 404.1575 - Evaluation guides if you are self-employed.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...DISABILITY INSURANCE (1950- ) Determining Disability and Blindness Substantial Gainful Activity § 404.1575 Evaluation...supplemental security income payments based on disability or blindness under title XVI of the Social Security Act, months for...

  3. 30 CFR 715.19 - Use of explosives.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...in emergency situations where rain, lightning, other atmospheric conditions, or...determined necessary to provide damage protection. (F) The regulatory authority...stemming; (xv) If mats or other protections were used; (xvi) Type of...

  4. 30 CFR 715.19 - Use of explosives.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...in emergency situations where rain, lightning, other atmospheric conditions, or...determined necessary to provide damage protection. (F) The regulatory authority...stemming; (xv) If mats or other protections were used; (xvi) Type of...

  5. 30 CFR 715.19 - Use of explosives.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...in emergency situations where rain, lightning, other atmospheric conditions, or...determined necessary to provide damage protection. (F) The regulatory authority...stemming; (xv) If mats or other protections were used; (xvi) Type of...

  6. 30 CFR 715.19 - Use of explosives.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...in emergency situations where rain, lightning, other atmospheric conditions, or...determined necessary to provide damage protection. (F) The regulatory authority...stemming; (xv) If mats or other protections were used; (xvi) Type of...

  7. 30 CFR 715.19 - Use of explosives.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...in emergency situations where rain, lightning, other atmospheric conditions, or...determined necessary to provide damage protection. (F) The regulatory authority...stemming; (xv) If mats or other protections were used; (xvi) Type of...

  8. 20 CFR 408.230 - When must you begin residing outside the United States?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS SVB Qualification and Entitlement Residence...claim, or (2) A determination that we made on a title II and/or a title XVI claim but only if the...

  9. 29 CFR 2590.606-4 - Notice requirements for plan administrators.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...continuation coverage benefits; (ii) Identification...determination by the Social Security Administration...title II or XVI of the Social Security Act (42 U...of disability by the Social Security Administration...the use of electronic media. (g) Model...

  10. 29 CFR 2590.606-1 - General notice of continuation coverage.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Continued) EMPLOYEE BENEFITS SECURITY ADMINISTRATION...a determination by the Social Security Administration, under title II or XVI of the Social Security Act (42 U.S...to the use of electronic media. (g) Model...

  11. 29 CFR 2590.606-1 - General notice of continuation coverage.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Continued) EMPLOYEE BENEFITS SECURITY ADMINISTRATION...a determination by the Social Security Administration, under title II or XVI of the Social Security Act (42 U.S...to the use of electronic media. (g) Model...

  12. 29 CFR 2590.606-1 - General notice of continuation coverage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Continued) EMPLOYEE BENEFITS SECURITY ADMINISTRATION...a determination by the Social Security Administration, under title II or XVI of the Social Security Act (42 U.S...to the use of electronic media. (g) Model...

  13. 29 CFR 2590.606-1 - General notice of continuation coverage.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Continued) EMPLOYEE BENEFITS SECURITY ADMINISTRATION...a determination by the Social Security Administration, under title II or XVI of the Social Security Act (42 U.S...to the use of electronic media. (g) Model...

  14. 29 CFR 2590.606-4 - Notice requirements for plan administrators.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...continuation coverage benefits; (ii) Identification...determination by the Social Security Administration...title II or XVI of the Social Security Act (42 U...of disability by the Social Security Administration...the use of electronic media. (g) Model...

  15. 29 CFR 2590.606-4 - Notice requirements for plan administrators.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...continuation coverage benefits; (ii) Identification...determination by the Social Security Administration...title II or XVI of the Social Security Act (42 U...of disability by the Social Security Administration...the use of electronic media. (g) Model...

  16. 29 CFR 2590.606-4 - Notice requirements for plan administrators.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...continuation coverage benefits; (ii) Identification...determination by the Social Security Administration...title II or XVI of the Social Security Act (42 U...of disability by the Social Security Administration...the use of electronic media. (g) Model...

  17. 29 CFR 2590.606-1 - General notice of continuation coverage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Continued) EMPLOYEE BENEFITS SECURITY ADMINISTRATION...a determination by the Social Security Administration, under title II or XVI of the Social Security Act (42 U.S...to the use of electronic media. (g) Model...

  18. 29 CFR 2590.606-4 - Notice requirements for plan administrators.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...continuation coverage benefits; (ii) Identification...determination by the Social Security Administration...title II or XVI of the Social Security Act (42 U...of disability by the Social Security Administration...the use of electronic media. (g) Model...

  19. HEU age determination

    SciTech Connect

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

    1994-12-31

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

  20. 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.

  1. Microcalorimetric and SAXS Determination of PEO-SDS Interactions: The Effect of Cosolutes Formed by Ions

    E-print Network

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

    2014-08-30

    The effect of different ionic cosolutes (NaCl, Na$_2$SO$_4$, Li$_2$SO$_4$, NaSCN, Na$_2$[Fe(CN)5NO], and Na$_3$[Co(NO)$_6$]) on the interaction between sodium dodecyl sulfate (SDS) and poly(ethylene oxide) (PEO) was examined by small-angle X-ray scattering (SAXS) and isothermal titration calorimetric techniques. The critical aggregation concentration values (cac), the saturation concentration ($C_2$), the integral enthalpy change for aggregate formation ($\\Delta H_{\\mbox{agg}}$(int)) and the standard free energy change of micelle adsorption on the macromolecule chain ( $\\Delta\\Delta G_{\\mbox{agg}}$) were derived from the calorimetric titration curves. In the presence of 1.00 mmol L$^{-1}$ cosolute, no changes in the parameters were observed when compared with those obtained for SDS-PEO interactions in pure water. For NaCl, Na$_2$SO$_4$, Li$_2$SO$_4$, and NaSCN at 10.0 and 100 mmol L$^{-1}$, the cosolute presence lowered cac, increased $C_2$, and the PEO-SDS aggregate became more stable. In the presence of Na$_2$[Fe(CN)5NO], the calorimetric titration curves changed drastically, showing a possible reduction in the PEO-SDS degree of interaction, possibility disrupting the formed nanostructure; however, the SAXS data confirmed, independent of the small energy observed, the presence of aggregates adsorbed on the polymer chain.

  2. Gears: Determining Angular Velocity

    NSDL National Science Digital Library

    AMPS GK-12 Program,

    Students work as engineers and learn to conduct controlled experiments by changing one experimental variable at a time to study its effect on the experiment outcome. Specifically, they conduct experiments to determine the angular velocity for a gear train with varying gear ratios and lengths. Student groups assemble LEGO® MINDSTORMS® NXT robots with variously sized gears in a gear train and then design programs using the NXT software to cause the motor to rotate all the gears in the gear train. They use the LEGO data logging program and light sensors to set up experiments. They run the program with the motor and the light sensor at the same time and analyze the resulting plot in order to determine the angular velocity using the provided physics-based equations. Finally, students manipulate the gear train with different gears and different lengths in order to analyze all these factors and figure out which manipulation has a higher angular velocity. They use the equations for circumference of a circle and angular velocity; and convert units between radians and degrees.

  3. 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.

  4. Pd-oxide equilibration: a new experimental method for the direct determination of oxide activities in melts and minerals

    NASA Astrophysics Data System (ADS)

    Chamberlin, Laurinda; Beckett, John R.; Stolper, Edward

    1994-03-01

    We have developed a new technique for the experimental determination of the activities of oxide components in melts and minerals using the equilibrium between Pd alloy, oxygen, and the oxide component in the sample of interest. If a melt or mineral sample is equilibrated with Pd metal at fixed P, T, and f O 2, a small amount of each constituent oxide will reduce to metal and dissolve into the Pd, forming an alloy. Due to the extraordinary stability of dilute alloys of Pd with Mg, Al, and Si, these metals dissolve into the Pd in amounts easily measured with the electron microprobe at f O 2 s that can be achieved with conventional gas-mixing techniques. We determined the activity-composition relations for Pd-Mg, -Al, and -Si alloys by equilibrating Pd at fixed f O 2and T with periclase, corundum, and cristobalite ( a oxide?1). Because Mg, Al, and Si have constant activity coefficients in Pd at low concentrations, the activity of the oxide of each metal is a simple function of the ratio of the concentration of the metal in Pd in equilibrium with the sample to that in Pd in equilibrium with the pure oxide. Therefore, if Pd plus a melt or mineral and Pd plus pure oxide standards are equilibrated simultaneously at fixed T and f O 2, the precision of the analytical technique is the major limitation on the determination of oxide activities. We used Pd-oxide equilibration to explore activities in silicate melts analogous to Type B Ca-Al-rich inclusions (CAIs) from carbonaceous chondrites; the measured activities deviate systematically from model valves but agree to within 1 30%. The activities imply that Type B CAIs did not condense as liquids from a gas of solar composition, and that only very aluminous compositions are potential liquid condensates from the solar nebula. We also used Pd-oxide equilibration to determine the free energy of formation from the oxides, ? G {/f /O}, of the spinel end-member MgAl2O4 at 1150 to 1400°C to a precision of 2 19% (1?). Because the technique reflects equilibration at high temperature, the ? G {/f /O} s accurately represent the mineral with equilibrium Mg-Al disorder at temperature, a feature not true of drop calorimetric results because of partial reordering during quenching. Our results indicate more negative ? G {/f Emphasis>/O}and hence higher entropy of formation, ? S {/f Emphasis>/O}, than given in most compilations of thermodynamic data for spinel.

  5. 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 results will show that the equal synaptic weight initialization method is superior to the one favoring the operational filter and that processing range and Doppler data together is superior to processing Doppler data alone. When processing range and Doppler with an equally initialized hierarchy, all three macromodes are definitively identified by the top-level gating network weights. Additionally, in the case of multiple successive macromode changes, the hierarchy is generally able to recover from one macromode and identify a change to another macromode.

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

    PubMed

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

    2014-06-19

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

  7. 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.

  8. Determinants of Food Allergy

    PubMed Central

    Masilamani, Madhan; Commins, Scott; Shreffler, Wayne

    2012-01-01

    SUMMARY Much has been learned by identifying the molecules that can be recognized by IgE from patients with allergies. Increasingly, by correlating patterns of sensitization with clinical features, it has become possible to distinguish molecules responsible for primary sensitization (complete allergens) from those that are more likely cross-reactive targets. In the case of animal allergens, evolutionary distance seems to be an important factor in determining allergenicity. However, until more is understood regarding the mechanistic details of primary sensitization, including the participation of molecules that stimulate innate immune responses and the repertoire of T-cell antigens, molecules that may or may not themselves be important B-cell antigens, we will not be able to explain fundamental questions, such as why peanut allergy is more severe than soy allergy or why tick exposure is associated with clinically relevant sensitization to a carbohydrate epitope. PMID:22244230

  9. Dietary determinants of obesity.

    PubMed

    Du, Huaidong; Feskens, Edith

    2010-08-01

    Obesity has become a serious public health problem worldwide, and dietary composition can play a role in its prevention and treatment. However, available literature on the impacts of different dietary factors on weight change is inconsistent, or even conflicting. In this review, we briefly summarized the mechanisms and influences of several major dietary determinants of weight change, with a focus on their potential in the prevention of weight gain or regain. We discussed the intake of fat, protein, total carbohydrates, fruits and vegetables, fibre, free sugars, fructose and sugar sweetened beverages, dietary energy density, portion size, eating outside home, glycaemic index and glycaemic load. Popular weight loss diets, including the Atkins diet, Weight Watchers, Ornish diet and Zone diet, are also briefly discussed for their safety and efficacy in the maintenance of weight loss. PMID:20821929

  10. Significant Radionuclides Determination

    SciTech Connect

    Jo A. Ziegler

    2001-07-31

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

  11. 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.

  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.

    USGS Publications Warehouse

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

    2003-01-01

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

  13. 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.

  14. Helical assemblies: Structure determinants.

    PubMed

    Kurochkina, Natalya A; Iadarola, Michael J

    2015-03-21

    Protein structural motifs such as helical assemblies and ??? barrels combine secondary structure elements with various types of interactions. Helix-helix interfaces of assemblies - Ankyrin, ARM/HEAT, PUM, LRR, and TPR repeats - exhibit unique amino acid composition and patterns of interactions that correlate with curvature of solenoids, surface geometry and mutual orientation of the helical edges. Inner rows of ankyrin, ARM/HEAT, and PUM-HD repeats utilize edges (i-1, i) and (i+1, i+2) for the interaction of the given ?-helix with preceding and following helices correspondingly, whereas outer rows of these proteins and LRR repeats invert this pattern and utilize edges (i-1, i) and (i-3, i-2). Arrangement of contacts observed in protein ligands that bind helical assemblies has to mimic the assembly pattern to provide the same curvature as a determinant of binding specificity. These characteristics are important for understanding fold recognition, specificity of protein-protein interactions, and design of new drugs and materials. PMID:25613414

  15. Ab initio nanostructure determination

    NASA Astrophysics Data System (ADS)

    Gujarathi, Saurabh

    Reconstruction of complex structures is an inverse problem arising in virtually all areas of science and technology, from protein structure determination to bulk heterostructure solar cells and the structure of nanoparticles. This problem is cast as a complex network problem where the edges in a network have weights equal to the Euclidean distance between their endpoints. A method, called Tribond, for the reconstruction of the locations of the nodes of the network given only the edge weights of the Euclidean network is presented. The timing results indicate that the algorithm is a low order polynomial in the number of nodes in the network in two dimensions. Reconstruction of Euclidean networks in two dimensions of about one thousand nodes in approximately twenty four hours on a desktop computer using this implementation is done. In three dimensions, the computational cost for the reconstruction is a higher order polynomial in the number of nodes and reconstruction of small Euclidean networks in three dimensions is shown. If a starting network of size five is assumed to be given, then for a network of size 100, the remaining reconstruction can be done in about two hours on a desktop computer. In situations when we have less precise data, modifications of the method may be necessary and are discussed. A related problem in one dimension known as the Optimal Golomb ruler (OGR) is also studied. A statistical physics Hamiltonian to describe the OGR problem is introduced and the first order phase transition from a symmetric low constraint phase to a complex symmetry broken phase at high constraint is studied. Despite the fact that the Hamiltonian is not disordered, the asymmetric phase is highly irregular with geometric frustration. The phase diagram is obtained and it is seen that even at a very low temperature T there is a phase transition at finite and non-zero value of the constraint parameter gamma/mu. Analytic calculations for the scaling of the density and free energy of the ruler are done and they are compared with those from the mean field approach. A scaling law is also derived for the length of OGR, which is consistent with Erdos conjecture and with numerical results.

  16. DETERMINATION OF CALORIES BY NIR

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  17. 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.

  18. Evaluation of the Westinghouse Leading Edge Flow Meter measurement system in the NSSS feedwater system application

    Microsoft Academic Search

    J. G. Doran; C. L. Gottshall

    1978-01-01

    A calorimetric test is the basis for determining the reactor thermal power level in a nuclear power plant, and feedwater flow is the primary contributor to this calorimetric test. Therefore, highly reliable and accurate feedwater flow measurements allow the nuclear instruments to more accurately reflect true reactor power, ensuring that the reactor core can be operated at the licensed reactor

  19. Teff and log g Determinations

    E-print Network

    Barry Smalley

    2005-09-19

    A discussion on the determination of effective temperature (Teff) and surface gravity (log g) is presented. The observational requirements for model-independent fundamental parameters are summarized, including an assessment of the accuracy of these values for the Sun and Vega. The use of various model-dependent techniques for determining Teff and log g are outlined, including photometry, flux fitting, and spectral line ratios. A combination of several of these techniques allows for the assessment of the quality of our parameter determinations. While some techniques can give precise parameter determinations, the overall accuracy of the values is significantly less and sometimes difficult to quantify.

  20. Cytokine determinants of viral tropism

    Microsoft Academic Search

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

    2009-01-01

    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

  1. DETERMINATION OF 'GIARDIA' CYST VIABILITY

    EPA Science Inventory

    The principal objective of this research was the development of a sensitive, standardized method of determining whether or not Giardia cysts are viable. The availability of such a method is necessary to determine the effect of chemical and physical agents on the viability of thes...

  2. ARTIFICIAL INTELLIGENCE Determining Optical Flow

    E-print Network

    Jiang, Hao

    ARTIFICIAL INTELLIGENCE Determining Optical Flow Berthold K.P. Horn and Brian G. Rhunck Artificial determined. Although some reference has been made to schemes for comput- Artificial Intelligence 17 (198I Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge,M A 02139, U.S.A. ABSTRACT

  3. Mouse Genetics: Determining gene function

    E-print Network

    Goldschmidt, Christina

    Mouse Genetics: Determining gene function An International Centre for Mouse Genetics Mammalian Genetics Unit #12;Determining gene function · Mutagenesis approaches · Gene-driven, phenotype for Mouse Genetics Mammalian Genetics Unit #12;An International Centre for Mouse Genetics Mammalian Genetics

  4. Determining laboratory value: Part 2.

    PubMed

    Stein, P

    1996-04-01

    This article describes how to determine a fair market value for a dental laboratory. Part one defined fair market value, addressed how value is perceived and how to prepare for laboratory evaluation. Part two addresses how to apply an appropriate valuation methodology to determine worth. PMID:9516270

  5. Determining laboratory value: Part 1.

    PubMed

    Stein, P

    1996-03-01

    This article will describe how to determine a fair market value for a dental laboratory. Part one addresses how to define fair market value, how value is perceived and how to prepare for laboratory evaluation. Part two, to be printed in April, will address how to apply an appropriate valuation methodology to determine worth. PMID:9516267

  6. Determinants of Levered Portfolio Performance

    E-print Network

    Anderson, Robert M.

    Determinants of Levered Portfolio Performance Robert M. Anderson Stephen W. Bianchi Lisa R Abstract The cumulative return to a levered strategy is determined by five elements that fit together to Lever." 1 #12;1 A Simple Two-Period Example In this paper, we show that there are five elements

  7. Method of determining glass durability

    DOEpatents

    Jantzen, Carol Maryanne (Aiken, SC); Pickett, John Butler (Aiken, SC); Brown, Kevin George (Augusta, GA); Edwards, Thomas Barry (Aiken, SC)

    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.

  8. 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.

  9. Boundary determinations for trivariate solids

    SciTech Connect

    Duchaineau, M; Joy, K I

    1999-05-14

    The trivariate tensor-product B-spline solid is a direct extension of the B-spline patch and has been shown to be useful in the creation and visualization of free-form geometric solids. Visualizing these solid objects requires the determination of the boundary surface of the solid, which is a combination of parametric and implicit surfaces. This paper presents a method that determines the implicit boundary surface by examination of the Jacobian determinant of the defining B-spline function. Using an approximation to this determinant, the domain space is adaptively subdivided until a mesh can be determined such that the boundary surface is close to linear in the cells of the mesh. A variation of the marching cubes algorithm is then used to draw the surface. Interval approximation techniques are used to approximate the Jacobian determinant and to approximate the Jacobian determinant gradient for use in the adaptive subdivision methods. This technique can be used to create free-form solid objects, useful in geometric modeling applications.

  10. Concept determination of human dignity.

    PubMed

    Edlund, Margareta; Lindwall, Lillemor; von Post, Iréne; Lindström, Unni Å

    2013-12-01

    This study presents findings from an ontological and contextual determination of the concept of dignity. The study had a caritative and caring science perspective and a hermeneutical design. The aim of this study was to increase caring science knowledge of dignity and to gain a determination of dignity as a concept. Eriksson's model for conceptual determination is made up of five part-studies. The ontological and contextual determination indicates that dignity can be understood as absolute dignity, the spiritual dimension characterized by responsibility, freedom, duty, and service, and relative dignity, characterized by the bodily, external aesthetic dimension and the psychical, inner ethical dimension. Dignity exists in human beings both as absolute and relative dignity. PMID:23812559

  11. Laboratory Determination of Hydraulic Conductivity

    NSDL National Science Digital Library

    From D.B. McWhorterand D. K. Sunda's 1977 Ground-Water Hydrology and Hydraulics, this two page excerpt outlines and details Laboratory Determination of Hydraulic Conductivity. Here, visitors will find illustrations and formula to understand the concept.

  12. Method for Determining Artillery Position

    NASA Technical Reports Server (NTRS)

    Fischer, Johannes; Meuser, Wilfried

    1988-01-01

    A method is described for determinig artillery positions. Two groups of four closely spaced microphones are placed at known positions, and radio bearings are determined by projectile flight time differences of muzzle blasts. The advantages of the method are discussed.

  13. Determining Cropland Share Rental Arrangements

    E-print Network

    Dhuyvetter, Kevin C.; Kastens, Terry L.; Outlaw, Joe

    1999-06-23

    Determining Cropland Share Rental Arrangements Kevin C. Dhuyvetter, Terry L. Kastens and Joe L. Outlaw * Many crop producers rely heavily on rented land in their farming operations. The rental arrangements between landowners and producers can...

  14. What Determines Gender in Humans?

    NSDL National Science Digital Library

    Scott Cooper

    In this activity students examine karyotypes from five individuals to try to identify which chromosomes determine gender in humans. This activity is also a good illustration of meiotic non-disjunction.

  15. Cotton Gin Dust Explosibility Determinations

    E-print Network

    Vanderlick, Francis Jerome

    2014-01-06

    Following the recent Imperial sugar dust explosion in 2008, a comprehensive survey of past dust explosions was conducted by the Occupational Safety and Health Administration (OSHA) to determine potential explosible dusts. After the survey, OSHA...

  16. 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.

  17. Crystal Structure Determination of New Antimitotic Agent Bis( p -fluorobenzyl)trisulfide

    Microsoft Academic Search

    Haoyun An; Xiurong Hu; Jianming Gu; Linshen Chen; Weiming Xu; Xiaopeng Mo; Wanhong Xu; Xiaobo Wang; Xiao Xu

    2008-01-01

    The purpose of this research was to investigate the physical characteristics and crystalline structure of bis(p-fluorobenzyl)trisulfide, a new anti-tumor agent. Methods used included X-ray single crystal diffraction, X-ray powder diffraction\\u000a (XRPD), Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetric (DSC) and thermogravimetric (TG)\\u000a analyses. The findings obtained with X-ray single crystal diffraction showed that a monoclinic unit cell was a?=?12.266(1) Å, b?=?4.7757(4) Å,

  18. Freedom and Determinism in Spinoza

    E-print Network

    Russell, John M.

    Freedom and Determinism in Spinoza JOHN N. RUSSELL Indiana Central University Spinoza's unrelenting emphasis on determinism and necessity seems, at first glance, incompatible with his espousal of human freedom. In what follows, I expli­ cate.... H. M. Elwes (Washington: M. Walter Dunne, Publisher, 1901), Eth. Ill: 2 Note. Ibid., Eth. I App. Ibid., Eth. II: 35 Note Ibid., Eth. I : 32 Proof Spinoza, Eth. I: 32 Cor. 2. Ibid., Eth. Ill: 2 Note. Ibid., Eth. I App. Ibid., Eth. I: 29...

  19. Gender determination of avian embryo

    DOEpatents

    Daum, Keith A. (Idaho Falls, ID); Atkinson, David A. (Idaho Falls, ID)

    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.

  20. Mass Determinations of Star Clusters

    E-print Network

    Georges Meylan

    2001-07-03

    Mass determinations are difficult to obtain and still frequently characterised by deceptively large uncertainties. We review below the various mass estimators used for star clusters of all ages and luminosities. We highlight a few recent results related to (i) very massive old star clusters, (ii) the differences and similarities between star clusters and cores of dwarf elliptical galaxies, and (iii) the possible strong biases on mass determination induced by tidal effects.

  1. Determinants of heart rate variability

    Microsoft Academic Search

    Hisako Tsuji; Ferdinand J. Venditti; Emily S. Manders; Jane C. Evans; Martin G. Larson; Charles L. Feldman; Daniel Levy

    1996-01-01

    Objectives. This study sought to examine clinical determinants of heart rate variability and to report normative reference values for eight heart rate variability measures.Background. Although the clinical implications of heart rate variability have been described, clinical determinants and normative values of heart rate variability measures have not been studied systematically in a large community-based population.Methods. The first 2 h of

  2. Determining a healthcare organization's value.

    PubMed

    Hahn, W

    1994-08-01

    As the consolidation activity among healthcare providers increases, it becomes more important than ever for healthcare financial managers to understand how to determine a healthcare organization's fair market value. There are many methods of determining an organization's value, but three general methods are the foundation of all others: the market comparable method, the underlying assets method, and the income, or cash flow, method. PMID:10146044

  3. 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

  4. 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.

  5. Method for determining artillery position

    NASA Technical Reports Server (NTRS)

    Fischer, Johannes; Loges, Werner; Meuser, Wilfried

    1988-01-01

    A method is disclosed for determining the position of cannon from measurement sites whose distance from each other lies in the same order of magnitude as the distance between the cannons -- that distance being in the kilometer range -- with the help of the travel time evaluation of muzzle blasts received at the measurement sites. There are at least two measurement sites, consisting of a cruciform of four microphones each positioned so that one axis is oriented to an arbitrarily chosen reference direction with the microphones spaced closely together. In this arrangement of diametrically opposed microphones, the respective travel times are determined and placed in a relationship whose arctangent is a radio bearing to the reference direction in which radio bearings are determined with consideration of their position and their opposing distance from the cannon position.

  6. 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.

  7. [Determination of aluminum in foods].

    PubMed

    Klaus, H; Quade, H D

    1979-01-01

    In connection with studies on the changes of functional properties of food constituents (e. g. solubility of proteins) by means of aluminium compounds, the elaboration of an appropriate method for the quantitative determination of aluminium has been necessary. The organic samples are mineralized with 80% perchloric acid; in case of fat-containing foods, after fat removal. After reaction with aluminon (ammonium salt of aurin tricarboxylic acid), aluminium is determined photometrically at 530 nm. The limit of detection lies between 1 and 2 ppm; the recovery rate is 103%; the standard deviation is +/- 10%. The determination (without mineralization) requires about 1 hours. The authors analyzed, inter alia, milk (1.2--1.7 ppm A1), fat cheese (9 ppm), micora (4 ppm), aluminium-stabilized protein texturates (300--1500 ppm). PMID:460394

  8. 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

  9. Determination of pyrotechnic functional margin

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1992-01-01

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

  10. 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.

  11. Determination of pyrotechnic functional margin

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Schimmel, Morry L.

    1993-01-01

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

  12. Bone strength and its determinants

    Microsoft Academic Search

    P. Ammann; R. Rizzoli

    2003-01-01

    Osteoporosis is a disease defined by decreased bone mass and alteration of microarchitecture which results in increased bone fragility and increased risk of fracture. The major complication of osteoporosis, i.e., fracture, is due to a lower bone strength. Thus, any treatment of osteoporosis implies an improvement in bone strength. Bone strength is determined by bone geometry, cortical thickness and porosity,

  13. Determination of heroin after embalmment

    Microsoft Academic Search

    V. Alunni-Perret; P. Kintz; B. Ludes; P. Ohayon; G. Quatrehomme

    2003-01-01

    A 30-year-old male died in Thailand after a scuffle. The corpse was embalmed and repatriated to France where an autopsy was performed. As usual in cases of embalmment, fluids such as blood and urine were unavailable and the toxicological analyses was performed on the bile and the liver. An overdose of heroin was determined as the cause of death. A

  14. 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…

  15. Using Parallax to Determine Distances

    NSDL National Science Digital Library

    This activity is designed to give students a better understanding of what parallax is and to gain some experience in using it. They will devise a method to calculate the distance of objects using observational data, describe how our eyes use parallax to determine the distance of objects, and make estimates of distances using parallax.

  16. DETERMINATION OF THORIUM IN ORES

    Microsoft Academic Search

    S. Sekine; T. Mochizuki

    1961-01-01

    A procedure for the determination of thorium in ores is as follows: The ; sample is decomposed with perchloric and hydrofluoric acids and is dissolved in ; hydrochloric acid. The residue is reserved. Sodium hydroxide precipitation is ; made and the precipitate is dissolved in nitric acid (solution A). The reserved ; residue is then used with sodium peroxide and

  17. Investigation of protein structure determination

    E-print Network

    Investigation of protein structure determination using X-ray free-electron lasers Dissertation zur sources, X-ray free-electron lasers (X- FEL's), several fields of research, including atomic and molecular Division in the Center for Free-electron Laser Science and graduate students of the Hamburg School

  18. Genetic modification and genetic determinism

    Microsoft Academic Search

    David B. Resnik; Daniel B. Vorhaus

    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

  19. Determinants and Polynomial Root Structure

    ERIC Educational Resources Information Center

    De Pillis, L. G.

    2005-01-01

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

  20. Determining Cropland Cash Rental Arrangements

    E-print Network

    Dhuyvetter, Kevin C.; Kastens, Terry L.; Outlaw, Joe

    1999-06-23

    Determining Cropland Cash Rental Arrangements Kevin C. Dhuyvetter, Terry L. Kastens and Joe L. Outlaw* Many crop producers rely heavily on rented land in their farming operations. Crop land is typically rented in one of three ways: (1) cash rent; (2...

  1. Cohesin in determining chromosome architecture

    SciTech Connect

    Haering, Christian H., E-mail: christian.haering@embl.de [Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg (Germany); Jessberger, Rolf, E-mail: rolf.jessberger@tu-dresden.de [Institute of Physiological Chemistry, Dresden University of Technology, Dresden (Germany)] [Institute of Physiological Chemistry, Dresden University of Technology, Dresden (Germany)

    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.

  2. The Determinants of Cardiac Output

    NSDL National Science Digital Library

    Anderson, Robert M.

    Part of the Gross Physiology of the Cardiovascular System site, this 22-minute video presentation explains fundamental but often misunderstood concepts about the determinants of cardiac output, using Dr. Anderson's hydraulic model of the cardiovascular system. It is a useful summary and overview of the concepts presented in greater detail in the online text. A transcript of the video presentation is available.

  3. Performing Determinism: Disability Culture Poetry

    Microsoft Academic Search

    Petra Kuppers

    2007-01-01

    “Performing Determinism” discusses the performance of disability through poetry: the instability of language, the ability of words to clasp both generic and specific meaning, and the gaps that surround the performances of self. Disability culture acts as a frame for the inquiry, as the essay discusses crip aesthetics, crip critical practice, and the embodiment of language. In the reading of

  4. 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…

  5. RADIOCHEMICAL DETERMINATION OF STRONTIUM90

    Microsoft Academic Search

    Harley

    1963-01-01

    Detailed procedures were developed for strontium-90 in foods and ; agricultural materials. Strontium-90 must be isolated from the bulk matrix of ; the sample, generally by wet or dry ashing followed by chemical or ion exchange. ; Non-radioactive strontium is added as a carrier because of the small mass of ; strontium-90. Final determination is made by letting strontium-90 and

  6. Factors determining desert dune type

    Microsoft Academic Search

    R. J. Wasson; R. Hyde

    1983-01-01

    While most observers recognize four elemental types of desert dunes (longitudinal, transverse, barchan and star1-3) there is little agreement about which factors determine these types. The angular relationships between the resultant of sand shifting winds and both the crest and principal slipfaces of the elemental types have been discussed qualitatively for many decades. These relationships have been quantified but the

  7. 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…

  8. 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…

  9. Determining centrifugal compressor piping loads

    SciTech Connect

    Kannappan, S.

    1982-02-01

    Guidelines for determining allowable piping loads on centrifugal compressor nozzles were changed in the 1979 edition of API Standard 617. This article explains the changes. Many still use the 1973 guidelines arriving at incorrect allowable values. It is recommended that allowable loads from manufacturers should be obtained and used when available. 6 refs.

  10. Determination of inulin in foods.

    PubMed

    Simonovska, B

    2000-01-01

    A method was developed for determining fructan inulin in various foods (yogurts, honey cakes, chocolates). Warm water was applied for extraction of samples, and mono- and dissacharides were determined by a thin-layer chromatographic densitometric method. A portion of the test solution was hydrolyzed 30 min with 1% oxalic acid in a boiling water bath. Fructose was determined in the hydrolysate. The amount of inulin in a sample was calculated as the difference between the amount of fructose in the sample before and after hydrolysis. The fructose from sucrose formed during the hydrolysis was also considered. The mean recovery from yogurt fortified with 4% inulin was 95.5 +/- 4.5% (mean +/- standard deviation); from honey cakes extract fortified with 10% inulin, 97.3 +/- 5.5%; and from chocolate extract fortified with 30% inulin, 98.6 +/- 6.6% (6 replicates in all cases). Determination of glucose is not necessary for analyzing fructans with the composition expressed shortened to GFn-1 (G, glucose; F, fructosyl) with the average degree of polymerization 8 < or = n < or = 15. PMID:10868592

  11. Deconstructing cell determination: proneural genes

    E-print Network

    Montpellier II, Université

    Deconstructing cell determination: proneural genes and neuronal identity Jean-Franc¸ ois Brunet1 to the relationship between the diversity of neural bHLH genes and the diversity of neuronal phenotypes. This article studies inspired by the established role of ``proneural'' genes in fly neurogenesis, as well

  12. National Mining Association Experimental Determination

    E-print Network

    Charcoal Canisters (LAACCs) Concluded that radon fluxes obeyed the Stagnant Film Model (SFM) and that flux with the dissolved Radium-226. A picture of the floating Large Area Activated Charcoal Canister (LAACC) used of determining Radon ­ 222 flux, specifically using Large Area Activated Charcoal Canisters (LAACCs) as described

  13. 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.

  14. 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).

  15. Cytokine determinants of viral tropism

    PubMed Central

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

    2015-01-01

    The specificity of a given virus for a ceil 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. PMID:19696766

  16. Determinants of skin sensitisation potential.

    PubMed

    Roberts, David W; Aptula, Aynur O

    2008-04-01

    Skin sensitisation is an important toxicological endpoint. The possibility that chemicals used in the workplace and in consumer products might cause skin sensitisation is a major concern for individuals, for employers and for marketing. In European REACH (Registration, Evaluation, and Authorisation of Chemicals) legislation, the sensitising potential should therefore be assessed for chemicals below the 10 ton threshold. Development of methods for prediction of skin sensitisation potential without animal testing has been an active research area for some time, but has received further impetus with the advent of REACH and the EU Cosmetics Directive (EU 2003). This paper addresses the issue of non-animal based prediction of sensitisation by a mechanistic approach. It is known that the sequence of molecular, biomolecular and cellular events between exposure to a skin sensitiser and development of the sensitised state involves several stages, in particular penetration through the stratum corneum, covalent binding to carrier protein, migration of Langerhans cells, presentation of the antigen to naïve T-cells. In this paper each of these stages is considered with respect to the extent to which it is dependent on the chemical properties of the sensitiser. The evidence suggests that, although penetration of the stratum corneum, stimulation of migration and maturation of Langerhans cells, and antigen recognition are important events in the induction of sensitisation, except in certain specific circumstances they can be taken for granted. They are not important factors in determining whether a compound will be a sensitiser or not, nor are they important factors in determining how potent one sensitiser will be relative to another. The ability to bind covalently to carrier protein is the major structure-dependent determinant of skin sensitisation potential. A chemistry-based prediction strategy is proposed involving reaction mechanistic domain assignment, reactivity and hydrophobicity determination, and application of quantitative mechanistic modelling (QMM) or read-across. PMID:17703504

  17. Determining Precise Positions of Supernovae

    NASA Astrophysics Data System (ADS)

    Penhallow, William S.

    1986-12-01

    A 0.25m/0.32m lenseless Schmidt camera mounted piggyback on the University of Rhode Island (URI) astrometric reflector (Penhallow 1978) is used to determine the positions of supernovae within 0.1 second of arc. Measurable 15.5 magnitude images can be obtained on hypered Kodak SR-5 x-ray film in 4 minutes under favorable conditions. Five exposures with about 16 reference stars are normally used.

  18. Range determination for scannerless imaging

    DOEpatents

    Muguira, Maritza Rosa (Albuquerque, NM); Sackos, John Theodore (Albuquerque, NM); Bradley, Bart Davis (Albuquerque, NM); Nellums, Robert (Albuquerque, NM)

    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.

  19. Situational determinants of fish consumption

    Microsoft Academic Search

    Sheena Leek; Sarah Maddock; Gordon Foxall

    2000-01-01

    Despite having properties well-suited to “healthy-eating”, fish is a declining product. Consumers’ evaluations of fish are known to differ between consumers and non-consumers, but the precise differences, which might be of use in the development of a marketing campaign, are vague. Analyses suggest that the factors that influence consumer choice are predominantly environmental, and a model of situational determinants of

  20. Strategies for graphical threshold determination.

    PubMed

    Vermont, J; Bosson, J L; François, P; Robert, C; Rueff, A; Demongeot, J

    1991-06-01

    Determining a threshold for a quantitative variable (arising in biological measurements for instance) is a common problem in medical decision making. We define seven commonly used strategies: each one leads to an optimal determination. To these strategies correspond relevant empirical curves: the ROC curve for strategies involving the sensitivity or the specificity, the predictive ROC curve (P-ROC curve) for strategies involving the positive and negative predicting values, and the well classified frequencies curve (WCF curve) for classification strategies where all misclassifications have the same importance. For one of the considered strategies, there also exists a theoretical formula for the optimal threshold, elicited within a classical probabilistic model, which gives a considerable advantage to this strategy. These strategies are applied to a stimulated example containing 702 cases, where we see that they lead to different optimal threshold values. Finally, we briefly review a practical application in the determination of thresholds for glycemia measurements, leading to the choice of one of them as the optimal one to consider in the gestational diabetes mellitus prediction. PMID:1914452

  1. Gender determination from pulpal tissue

    PubMed Central

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

    2014-01-01

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

  2. 76 FR 56263 - Titles II and XVI: Documenting and Evaluating Disability in Young Adults

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-12

    ...Documenting and Evaluating Disability in Young Adults AGENCY...documenting and evaluating disability in young adults. DATES...MDI, such as a learning disability or language disorder. Any...person who has borderline intellectual functioning (BIF) may...

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

    NASA Astrophysics Data System (ADS)

    Sears, Derek W. G.

    2012-03-01

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

  4. ENVIRONMENTAL CONSIDERATIONS OF SELECTED ENERGY-CONSERVING MANUFACTURING PROCESS OPTIONS. VOLUME XVI. SULFUR OXIDES SUMMARY REPORT

    EPA Science Inventory

    Arthur D. Little, Inc. undertook a study of the 'Environmental Considerations of Selected Energy-Conserving Manufacturing Process Options'. Some 80 industrial process options were examined in 13 industrial sectors. Results were published in 15 volumes, including a summary, indust...

  5. 2014, XVI, 294 p. 81 illus., 73 illus. in color. Printed book

    E-print Network

    Alippi, Cesare

    .00 *139,09 (D) | 142,99 (A) | CHF 173.50 eBook Available from your library or springer.com/shop MyCopy Printed eBook for just | $ 24.99 springer.com/mycopy Order online at springer.com or for the Americas call (toll free) 1-800-SPRINGER or email us at: orders- ny@springer.com. For outside the Americas

  6. 1st Edition., 2011, XVI, 460 p. 196 illus., 30 Printed book

    E-print Network

    Stølen, Ketil

    .00 | $99.00 *85,55 (D) | 87,95 (A) | CHF 115.00 eBook Available from libraries offering Springer's eBook Collection, or for individual purchase via online bookstores. A free preview is available on SpringerLink. springer.com/ebooks MyCopy Printed eBook exclusively available to patrons whose library offers Springer's eBook

  7. Diffuse idiopathic skeletal hyperostosis in the Medici, Grand Dukes of Florence (XVI century)

    PubMed Central

    Giusiani, Sara; Fornaciari, Antonio; Villari, Natale; Vitiello, Angelica; Fornaciari, Gino

    2009-01-01

    Diffuse idiopathic skeletal hyperostosis (DISH) is a common systemic disorder characterised by the ossification of the anterior longitudinal spinal ligament involving at least three contiguous vertebrae and by diffuse extraspinal enthesopathies. The condition is associated with the male sex and with advanced age; its aetiology is uncertain, but seems to be related to obesity and diabetes. The most recent studies in archaeological series demonstrated a relation between high social status and the incidence of DISH. The present study examines two cases of DISH found amongst the members of the Medici family buried in the Basilica of San Lorenzo in Florence. The skeletons of the Grand Dukes Cosimo I (1519–1574) and his son Ferdinand I (1549–1609) showed the typical features of the condition. This result is related to the obesity of the Grand Dukes, attested by the written and artistic sources, and to the protein-based alimentation demonstrated by a paleonutritional study, thus furnishing further evidence to the significance of DISH as a life style. PMID:19669655

  8. Recombination and Electron Impact Excitation Rate Coefficients for S XV and S XVI

    NASA Astrophysics Data System (ADS)

    Mahmood, S.; Ali, S.; Orban, I.; Tashenov, S.; Lindroth, E.; Schuch, R.

    2012-08-01

    Recombination and electron impact excitation of S14+ and S15+ ions was measured at the Stockholm refrigerated electron beam ion trap. The collision energy range was 1.4-3 keV, in which we covered the KLL, KLM, KLN, and KLO dielectronic recombination resonances resulting in S13+ and S14+ ions. The recombination rates were obtained by detecting the charge state distribution with a newly developed time-of-flight technique. Resonance energies and cross-sections calculated within the relativistic many-body perturbation theory for S15+ agree well with the experimental data. The temperature-dependent rate coefficients were extracted from the measured rates and compared with calculations from the literature used for studies of collisionally ionized astrophysical plasmas. Good agreement for S15+ was obtained, while the plasma rates for S14+ were 23% lower than the current published values. In addition to the time-of-flight spectra, the X-ray spectra, produced mainly by photo-recombination and excitation, were also collected. The combination of these two measurements allowed us to separate the photo-recombination and the excitation spectra, and the excitation rate coefficients for summed intensities with known fractions of S14+ and S15+ ions were extracted.

  9. Volume XVI, No. 2 A publication of the U.S. Army Installation Management Agency

    E-print Network

    US Army Corps of Engineers

    Baltimore, MD On the cover: Townhouses for Junior NCOs and their families at Fort Meade, MD. March by Marshall Hudson 14 Army approves new Historic Preservation Campaign Plan by Margaret Schnebly 15 Capehart

  10. Exito para el XVI Festival Internacional de Teatro Hispano del Teatro Avante

    E-print Network

    Marrero, Marí a Teresa

    2002-04-01

    Nueva York del 20 al 30 de junio 2001 en el New 42nd Street Studios logró traer maravillosos representantes del teatro latinoamericano y español contemporáneo. En Miami el programa incluyó: Cenizas sobre el mar (Colombia/Miami), La ciudad sitiada...) y Melodrama (Brasil). Y hubo tres obras de teatrodanza: Jacinta-todas las plegarias (Ecuador/EEUU), Seque volverás (Colombia) y Materia (Brasil). Por último el Teatro Taller de Colombia presentó Los cíngaros, obra para espacios abiertos públicos...

  11. SPIE Proceedings, Ophthalmic Technologies XVI, vol. 6138 (2006) Noninvasive Dosimetry and Monitoring of TTT

    E-print Network

    Palanker, Daniel

    2006-01-01

    , Stanford University, CA 94305, USA 3 Biomedical Imaging and Spectroscopy Laboratory, Beth Israel Deaconess) is a slow (60 seconds) photothermal treatment of the fundus with a near-infrared (780-810nm) laser it is known that the margin between an effective expression of HSP and a cellular death is quite small

  12. 20 CFR 416.590 - Are there additional methods for recovery of title XVI benefit overpayments?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...this chapter applies only under the following conditions...overpayment occurred after you attained age 18; (2) You...or § 416.582 or, after a review conducted pursuant...1407 and 416.1409 or, after a review conducted...

  13. 20 CFR 416.590 - Are there additional methods for recovery of title XVI benefit overpayments?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...this chapter applies only under the following conditions...overpayment occurred after you attained age 18; (2) You...or § 416.582 or, after a review conducted pursuant...1407 and 416.1409 or, after a review conducted...

  14. 20 CFR 416.590 - Are there additional methods for recovery of title XVI benefit overpayments?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...this chapter applies only under the following conditions...overpayment occurred after you attained age 18; (2) You...or § 416.582 or, after a review conducted pursuant...1407 and 416.1409 or, after a review conducted...

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...this chapter applies only under the following conditions...overpayment occurred after you attained age 18; (2) You...or § 416.582 or, after a review conducted pursuant...1407 and 416.1409 or, after a review conducted...

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...this chapter applies only under the following conditions...overpayment occurred after you attained age 18; (2) You...or § 416.582 or, after a review conducted pursuant...1407 and 416.1409 or, after a review conducted...

  17. Spectroscopic studies of cutaneous photosensitizing agents--XVI. Disperse blue 35.

    PubMed

    Dabestani, R; Reszka, K J; Davis, D G; Sik, R H; Chignell, C F

    1991-07-01

    The photochemistry (Type I and II) of the phototoxic textile dye Disperse Blue (DB-35) and its purified components has been studied using electron spin resonance in conjunction with spin trapping technique and the direct detection of singlet oxygen (1O2) luminescence. The main components of DB-35 (which is synthesized by the successive nitration, reduction and methylation of 1,8-dihydroxy-anthraquinone) were separated by HPLC and identified by mass spectrometry and 2-D NMR as 4,5-diamino-1,8-dihydroxyanthraquinone (4,5-DDHAQ; 62% of total dye) and 2,7-diamino-1,8-dihydroxyanthraquinone (2,7-DDHAQ; 31% of total dye). Minor components included 2,5-diamino-1,8-dihydroxyanthraquinone (2,5-DDHAQ) and a monomethylated derivative of either 4,5-DDHAQ or 2,7-DDHAQ. Irradiation (624 nm) of 4,5-DDHAQ and 2,7-DDHAQ in dimethylsulfoxide resulted in the generation of superoxide which was trapped by 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). Visible light irradiation of the components in ethanol generated 1O2 with the yields decreasing in the following order: 4,5-DDHAQ greater than 2,5-DDHAQ greater than 2,7-DDHAQ. These findings indicate that upon irradiation by visible light DB-35 can generate active oxygen species which may be responsible for the photocontact dermatitis caused by this dye. PMID:1658824

  18. Molecular Rydberg transitions. XVI. MCD of CH/sub 3/Br

    SciTech Connect

    McGlynn, S.P.; Scott, J.D.; Felps, W.S.; Findley, G.L.

    1980-01-01

    Magnetic circular dichroism, first derivative (of absorption), and absorption spectra of methyl bromide are presented for the first s--Rydberg transition region, 55 000--61 000 cm/sup -1/. A straightforward analysis in terms of the ratios (MCD/derivative) of the signal amplitudes yields a unique identification of the first s--Rydberg states, /sup 3/E/sub(/sub 1/) and /sup 1/E/sub(/sub 1/). These identifications, in conjunction with oscillator strength ratios and an intermediate coupling model, lead to an assignment of the remaining first s--Rydberg states /sup 3/E/sub(/sub 2/) and /sup 3/E/sub() 0plus-or-minus/. All of these assignments are corroborative of ones based on vibrational analyses and extrapolations (S. Felps, P. Hochmann, P. Brint, and S. P. McGlynn, J. Mol. Spectrosc. 59, 355 (1976)). The power of MCD techniques in VUV Rydberg analyses is strikingly demonstrated.

  19. Follow-Up Study of Former Students of the Data Processing Program. Volume XVI, No. 3.

    ERIC Educational Resources Information Center

    Rilki, Ernest; Lucas, John A.

    In spring 1987, a follow-up survey was conducted of former William Rainey Harper College (WRHC) students who had taken five or more data processing courses at the college between 1980 and 1986. The survey focused on the students' employment status and educational intent while attending WRHC, their present employment situation, and their evaluation…

  20. Volume XVI, No. 5 A publication of the U.S. Army Installation Management Agency

    E-print Network

    US Army Corps of Engineers

    /October 2004 U.S. Army Installation Management Agency In this issue: Energy Management and Water Conservation .................................................................................................................................................................................... 4 2004 Energy and Water Management awards by David Purcell 5 USMA wins award for energy efficiency 6) by Henry Gignilliat 18 Army Utility Services Regulation update by William F. Eng Water Conservation

  1. l contenido econmico del XVI Con-greso del Partido Comunista Chino

    E-print Network

    García-Berthou, Emili

    Organiza- ción Mundial del Comercio; Pekín ha sido ele- gida sede de los Juegos Olímpicos del 2008; el PCCh internacional, sino que la propia estruc- tura interna se configura según las prioridades de una economía

  2. RECOMBINATION AND ELECTRON IMPACT EXCITATION RATE COEFFICIENTS FOR S XV AND S XVI

    SciTech Connect

    Mahmood, S.; Ali, S.; Orban, I.; Lindroth, E.; Schuch, R. [Department of Physics, Stockholm University, AlbaNova University Center, S-10691 Stockholm (Sweden); Tashenov, S. [Current address: Physikalisches Institut, Universitaet Heidelberg, D-69120 Heidelberg, Germany. (Germany)

    2012-08-01

    Recombination and electron impact excitation of S{sup 14+} and S{sup 15+} ions was measured at the Stockholm refrigerated electron beam ion trap. The collision energy range was 1.4-3 keV, in which we covered the KLL, KLM, KLN, and KLO dielectronic recombination resonances resulting in S{sup 13+} and S{sup 14+} ions. The recombination rates were obtained by detecting the charge state distribution with a newly developed time-of-flight technique. Resonance energies and cross-sections calculated within the relativistic many-body perturbation theory for S{sup 15+} agree well with the experimental data. The temperature-dependent rate coefficients were extracted from the measured rates and compared with calculations from the literature used for studies of collisionally ionized astrophysical plasmas. Good agreement for S{sup 15+} was obtained, while the plasma rates for S{sup 14+} were 23% lower than the current published values. In addition to the time-of-flight spectra, the X-ray spectra, produced mainly by photo-recombination and excitation, were also collected. The combination of these two measurements allowed us to separate the photo-recombination and the excitation spectra, and the excitation rate coefficients for summed intensities with known fractions of S{sup 14+} and S{sup 15+} ions were extracted.

  3. Micro-Raman identification of the palette of a precious XVI century illuminated Persian codex

    Microsoft Academic Search

    Silvia Bruni; Franco Cariati; Francesca Casadio; Vittoria Guglielmi

    2001-01-01

    A remarkable, richly decorated Persian manuscript dating from 1537 was investigated by Raman microscopy in order to assess the nature of the pigments used. Although the decorated area measures just a few tens of cm2 and doesn’t include any anthropomorphic motif, but consists in a very geometric, lacework-like decoration, it contains very elaborate and precious details. A very rich palette

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

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  5. 78 FR 77481 - Proposed Flood Hazard Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-23

    ...FEMA-B-1352] Proposed Flood Hazard Determinations...Federal Emergency Management Agency, DHS. ACTION...These proposed flood hazard determinations...with the floodplain management criteria required...entities. These flood hazard determinations...meet the floodplain management requirements...

  6. 36 CFR 223.36 - Volume determination.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Volume determination. 223.36 Section 223...Conditions and Provisions § 223.36 Volume determination. (a) Timber sale contracts may provide for volume determination by scaling,...

  7. 36 CFR 223.36 - Volume determination.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Volume determination. 223.36 Section 223...Conditions and Provisions § 223.36 Volume determination. (a) Timber sale contracts may provide for volume determination by scaling,...

  8. 36 CFR 223.36 - Volume determination.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Volume determination. 223.36 Section 223...Conditions and Provisions § 223.36 Volume determination. (a) Timber sale contracts may provide for volume determination by scaling,...

  9. 36 CFR 223.36 - Volume determination.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Volume determination. 223.36 Section 223...Conditions and Provisions § 223.36 Volume determination. (a) Timber sale contracts may provide for volume determination by scaling,...

  10. 36 CFR 223.36 - Volume determination.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Volume determination. 223.36 Section 223...Conditions and Provisions § 223.36 Volume determination. (a) Timber sale contracts may provide for volume determination by scaling,...

  11. 19 CFR 351.205 - Preliminary determination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Duty) Determination,” including the rates, if any, and an invitation for argument consistent with § 351.309. (d) Effect of affirmative preliminary determination. If the preliminary determination is affirmative, the Secretary will...

  12. 19 CFR 351.210 - Final determination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Affirmative (Negative) Final Antidumping (Countervailing Duty) Determination,” including the rates, if any. (d) Effect of affirmative final determination. If the final determination is affirmative, the Secretary will take the...

  13. 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

  14. Soil carbon determination by thermogravimetrics.

    PubMed

    Pallasser, Robert; Minasny, Budiman; 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

  15. 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

  16. Evaluation of spherical GJMS determinants

    E-print Network

    Toufik Mansour; J. S. Dowker

    2014-07-23

    An expression in the form of an easily computed integral is given for the determinant of the scalar GJMS operator on an odd--dimensional sphere. Manipulation yields a sum formula for the logdet in terms of the logdets of the ordinary conformal Laplacian for other dimensions. This is formalised and expanded by an analytical treatment of the integral which produces an explicit combinatorial expression directly in terms of the Riemann zeta function, and $\\log2$. An incidental byproduct is a (known) expression for the central factorial coefficients in terms of higher Bernoulli numbers.

  17. Structure determination of enterovirus 71

    SciTech Connect

    Plevka, Pavel; Perera, Rushika; Cardosa, Jane; Kuhn, Richard J.; Rossmann, Michael G. (Purdue); (Sentinext)

    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.

  18. Determinants of internet poker adoption.

    PubMed

    Philander, Kahlil S; Abarbanel, B Lillian

    2014-09-01

    In nearly all jurisdictions, adoption of a new form of gambling has been a controversial and contentious subject. Online gambling has been no different, though there are many aspects that affect online gambling that do not appear in the brick and mortar environment. This study seeks to identify whether demographic, economic, political, technological, and/or sociological determinants contribute to online poker gambling adoption. A theoretical discussion of these categories' importance to online poker is provided and exploratory empirical analysis is used to examine their potential validity. The analysis revealed support for all of the proposed categories of variables thought to be predictive of online gambling legality. PMID:23661279

  19. Determining $?$ from cluster correlation function

    E-print Network

    A. Kashlinsky

    1998-06-17

    It is shown how data on the cluster correlation function can be used in order to reconstruct the density of the pregalactic density field on the cluster mass scale. The method is applied to the data on the cluster correlation amplitude -- richness dependence. The spectrum of the recovered density field has the same shape as the density field derived from data on the galaxy correlation function which is measured as function of linear scales. Matching the two amplitudes relates the mass to the comoving scale it contains and thereby leads to a direct determination of $\\Omega$. The resultant density parameter turns out to be $\\Omega$=0.25.

  20. Crystal face temperature determination means

    DOEpatents

    Nason, D.O.; Burger, A.

    1994-11-22

    An optically transparent furnace having a detection apparatus with a pedestal enclosed in an evacuated ampule for growing a crystal thereon is disclosed. Temperature differential is provided by a source heater, a base heater and a cold finger such that material migrates from a polycrystalline source material to grow the crystal. A quartz halogen lamp projects a collimated beam onto the crystal and a reflected beam is analyzed by a double monochromator and photomultiplier detection spectrometer and the detected peak position in the reflected energy spectrum of the reflected beam is interpreted to determine surface temperature of the crystal. 3 figs.

  1. 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.

  2. Liquid chromatographic determination of water

    DOEpatents

    Fortier, Nancy E. (Fairfield, OH); Fritz, James S. (Ames, IA)

    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.

  3. Shape Determination for Deformed Cavities

    SciTech Connect

    Lee, Lie-Quan; Akcelik, Volkan; Chen, Sheng; Ge, Lixin; Li, Zenghai; Ng, Cho; Xiao, Liling; Ko, Kwok; /SLAC; Ghattas, Omar; /Texas U.

    2006-10-04

    A realistic superconducting RF cavity has its shape deformed comparing to its designed shape due to the loose tolerance in the fabrication process and the frequency tuning for its accelerating mode. A PDE-constrained optimization problem is proposed to determine the deformation of the cavity. A reduce space method is used to solve the PDE-constrained optimization problem where design sensitivities were computed using a continuous adjoint approach. A proof-of-concept example is given in which the deformation parameters of a single cavity-cell with two different types of deformation were computed.

  4. Calculator programs determine drilling hydraulics

    SciTech Connect

    Landry, W.E.

    1987-05-01

    Two TI-59 programs were prepared for the calculation of drilling hydraulics as set forth in the Hughes Tool Co. publication, Practical Hydraulics. One presents the stepwise determination of drill string pressure drop while the second, to be published in a future issue, calculates jet area, jet velocity and impact force along with bit pressure drop and hydraulic horsepower. Another section of the second program considers pump mechanics, calculating the required strokes per minute to attain a specific circulating rate, or the circulation that would result from a specific pump speed. Hydraulic horsepower of the pump is then calculated from this rate and a maximum pump pressure.

  5. How to determine ‘dry weight'?

    PubMed Central

    Gunal, Ali I

    2013-01-01

    Sodium and fluid retention in dialysis patients is associated with hypertension and vascular changes that may ultimately lead to serious cardiovascular complications. Achieving and maintaining dry weight appears to be an effective but forgotten strategy in controlling and maintaining normal blood pressure among hypertensive patients on dialysis. A crucial question is how to determine ‘dry weight'. Normotension without the use of antihypertensive medications in conjunction with a cardio-thoracic index below 48% is the most important criterion showing that the dry weight is achieved. PMID:25028642

  6. Measuring times to determine positions

    E-print Network

    Sparavigna, Amelia Carolina

    2012-01-01

    Among the first devices used to measure the time we find the sundials and the water-clocks, as told by Vitruvius in his book on the Architecture. The sundials work because of the shadows cast by a rod or pole, the gnomon, on their basements. Besides being an instrument able to measure the time intervals, the sundial provided information on Earth and heaven to the ancient astronomers. Here we discuss how this device is able to determine the latitude and the north-south direction. The problem of the longitude is also shortly discussed.

  7. Local determinants of contour interpolation

    PubMed Central

    Maertens, Marianne; Shapley, Robert

    2011-01-01

    Objects in our visual environment are perceived as integral wholes even when their retinal images are incomplete. We ask whether the perceptual precision of subjective interpolation between isolated image parts depends on the overall proportion of visible image information or rather on its geometrical arrangement. We used Varin-type subjective shapes that provide less physical stimulus information than Kanizsa-type figures because partially occluded solid inducers are replaced by partially occluded concentric arcs. We tested whether perceptual precision varies as a function of contour support, or alternatively, depends on the number of, and the distance between, line endings within the inducers. We measured performance in a probe localization task, where a small target is presented at different distances around a subjective boundary. Sensitivity, captured by the just noticeable position difference between in- and outside probes, crucially depended on the geometric arrangement of line ends in the Varin figures. This is objective evidence that the apparent subjective contour strength does not primarily depend on contour support but is determined by the number and the separation between inducers’ line endings. The results suggest that neuronal mechanisms sensitive to highly localized 2D features are crucial for determining the perceived shape of visual objects. PMID:19146236

  8. Precise orbit determination for GRACE

    NASA Astrophysics Data System (ADS)

    Kang, Z.; Nagel, P.; Pastor, R.

    2003-04-01

    The twin, co-orbiting GRACE (Gravity Recovery and Climate Experiment) satellites were launched in March 2002. The primary objective of the GRACE mission is to determine the Earth's gravity field and its temporal variations with unprecedented accuracy. To satisfy this objective as well as other applications (e.g. atmospheric profiling by radio occultation), accurate orbits for GRACE are required. This paper describes several results related to the use of the data collected by the GRACE GPS receiver, high precision accelerometer observations and precise attitude data from star trackers in the application of the GRACE Precise Orbit Determination (POD). The orbit accuracy is assessed using a number of tests, which include analysis of GPS tracking observation residuals, Satellite Laser Ranging (SLR) residuals, K-Band Ranging (KBR) residuals and external orbit comparisons. The results show that an accuracy of better than 5 cm in each direction for GRACE orbits can be obtained. The relative accuracy of the two GRACE satellites is about 1 cm in position and 10 micrometers per second in velocity.

  9. Determination of a mutational spectrum

    SciTech Connect

    Thilly, W.G.; Keohavong, P.

    1991-09-03

    A method is disclosed of resolving (physically separating) mutant DNA from nonmutant DNA. A method is also described 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. 3 figures.

  10. 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.

  11. Electrical Forces Determine Glomerular Permeability

    PubMed Central

    Hausmann, Ralf; Kuppe, Christoph; Egger, Herbert; Schweda, Frank; Knecht, Volker; Elger, Marlies; Menzel, Sylvia; Somers, Douglas; Braun, Gerald; Fuss, Astrid; Uhlig, Sandra; Kriz, Wilhelm; Tanner, George; Floege, Jürgen

    2010-01-01

    There is ongoing controversy about the mechanisms that determine the characteristics of the glomerular filter. Here, we tested whether flow across the glomerular filter generates extracellular electrical potential differences, which could be an important determinant of glomerular filtration. In micropuncture experiments in Necturus maculosus, we measured a potential difference across the glomerular filtration barrier that was proportional to filtration pressure (?0.045 mV/10 cm H2O). The filtration-dependent potential was generated without temporal delay and was negative within Bowman's space. Perfusion with the cationic polymer protamine abolished the potential difference. We propose a mathematical model that considers the relative contributions of diffusion, convection, and electrophoretic effects on the total flux of albumin across the filter. According to this model, potential differences of ?0.02 to ?0.05 mV can induce electrophoretic effects that significantly influence the glomerular sieving coefficient of albumin. This model of glomerular filtration has the potential to provide a mechanistic theory, based on experimental data, about the filtration characteristics of the glomerular filtration barrier. It provides a unique approach to the microanatomy of the glomerulus, renal autoregulation, and the pathogenesis of proteinuria. PMID:20947631

  12. Activity determination of (59)Fe.

    PubMed

    Kossert, Karsten; Nähle, Ole J

    2014-11-01

    Iron-59 was measured in three commercial and two custom-built liquid scintillation counters. The counting efficiencies were determined using CIEMAT/NIST efficiency tracing and the triple-to-double coincidence ratio (TDCR) method, respectively. The efficiency computation for the TDCR method was realized by means of the MICELLE2 program, applying a stochastic model for the computation of electron emission spectra. The program was extended to make calculations of spectra originating from complex decay schemes possible. In addition, a new parameterization of electron stopping powers for 10 commercial liquid scintillation cocktails was included in the software. The activities determined with the two methods were in very good agreement; the relative standard uncertainty of the combined result was found to be 0.16%. It was used to calibrate a 4? ionization chamber at PTB for future calibrations of this isotope which is used for investigations of iron metabolism. A standardized solution was submitted to the Bureau International des Poids et Mesures (BIPM) to be measured in the ionization chambers of the International Reference System (SIR) for comparison purposes. The liquid scintillation samples were also measured in a new portable TDCR system with three channel photomultipliers. Although this system has a much lower counting efficiency, the activity was in satisfactory agreement with the conventional TDCR system. The usage of the portable TDCR system, thus, provides an important test of the free parameter model. PMID:24530318

  13. Determination of a mutational spectrum

    DOEpatents

    Thilly, William G. (Winchester, MA); Keohavong, Phouthone (Cambridge, MA)

    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.

  14. Determinants of Outbreak Detection Performance

    PubMed Central

    Jafarpour, Nastaran; Precup, Doina; Buckeridge, David

    2013-01-01

    Objective To predict the performance of outbreak detection algorithms under different circumstances which will guide the method selection and algorithm configuration in surveillance systems, to characterize the dependence of the performance of detection algorithms on the type and severity of outbreak, to develop quantitative evidence about determinants of detection performance. Introduction The choice of outbreak detection algorithm and its configuration can result in important variations in the performance of public health surveillance systems. Our work aims to characterize the performance of detectors based on outbreak types. We are using Bayesian networks (BN) to model the relationships between determinants of outbreak detection and the detection performance based on a significant study on simulated data. Methods The simulated surveillance data that we used was generated by Surveillance Lab of McGill University using Simulation Analysis Platform [1] considering surveillance in an urban area to detect waterborne outbreaks due to the failure of a water treatment plant. We focus on predicting the performance of the C-family of algorithms, because they are widely used, state-of-art outbreak detection algorithms [2]. We investigate the influence of algorithm characteristics and outbreak characteristics in determining outbreak detection performance. The C1, C2, and C3 are distinguished by the configuration of 2 parameters,the guardband and memory. Generally, gradually increasing outbreaks can bias the test statistic upward, so the detection algorithm will fail to flag the outbreak. To avoid this situation, the C2 and C3 use a 2-day gap, guardband, between the baseline interval and the test interval. The C3 includes 2 recent observations, called memory, in the computation of the test statistic. The W2 algorithm is a modified version of the C2 which takes weekly patterns of surveillance time series into account [3]. In the W2, the baseline data is stratified to 2 distinct baselines: one for weekdays, the other for weekends. The W3 includes 2 recent observations of each baseline while calculating the test statistic in the corresponding baseline. We ran the C1, C2, C3, W2, and W3 on 18k simulated time series and measured the sensitivity and specificity of detection. Then we created the training data set of 5400000 instances. Each instance was the result of performance evaluation of an outbreak detection algorithm with a specific setting of parameters. In order to investigate the determinants of detection performance and reveal their effects quantitatively, we used BN to predict the performance based on algorithm characteristics and outbreak characteristics. Results We developed 2 BN models in the Weka machine learning software [4] using 5-fold cross-validation. The first BN determines the effect of the guardband, memory, alerting threshold, and the weekly pattern indicator (0 for C-algorithms, 1 for W-algorithms) and outbreak characteristics (contamination level and duration) on the sensitivity of detection. The value of sensitivity was mapped to 4 classes: (0, 0.3], (0.3, 0.6], (0.6, 0.9], (0.9, 1]. The developed BN correctly classified 67.74% of instances. The misclassification error was 0.9407. The second BN for predicting the specificity of detection correctly classified 95.895% of instances in 10 classes and the misclassification error was 0.2975. Conclusions The contamination level and duration of outbreaks, alerting threshold, memory, guardband, and whether the weekly pattern was considered or not influence the sensitivity and specificity of outbreak detection and given the C-algorithm parameter settings, we can predict outbreak detection performance quantitatively. In future work, we plan to investigate other predictors of performance and study how these predictions can be used in algorithm and policy choices.

  15. 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.

  16. Determining the dynamics of entanglement.

    PubMed

    Jiménez Farías, O; Lombard Latune, C; Walborn, S P; Davidovich, L; Souto Ribeiro, P H

    2009-06-12

    The estimation of the entanglement of multipartite systems undergoing decoherence is important for assessing the robustness of quantum information processes. It usually requires access to the final state and its full reconstruction through quantum tomography. General dynamical laws may simplify this task. We found that when one of the parties of an initially entangled two-qubit system is subject to a noisy channel, a single universal curve describes the dynamics of entanglement for both pure and mixed states, including those for which entanglement suddenly disappears. Our result, which is experimentally demonstrated using a linear optics setup, leads to a direct and efficient determination of entanglement through the knowledge of the initial state and single-party process tomography alone, foregoing the need to reconstruct the final state. PMID:19443736

  17. Prospective errors determine motor learning.

    PubMed

    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

  18. T-Cell Lineage Determination

    PubMed Central

    Yang, Qi; Bell, J. Jeremiah; Bhandoola, Avinash

    2010-01-01

    Summary T cells originate from hematopoietic stem cells (HSCs) in the bone marrow but complete their development in the thymus. HSCs give rise to a variety of non-renewing hematopoietic progenitors, among which a rare subset migrates to the thymus via the bloodstream. The earliest T-cell progenitors identified in the thymus are not T-lineage restricted but possess the ability to give rise to cells of many different lineages. Alternative lineage potentials are gradually lost as progenitors progress towards later developmental stages. Here, we review the early developmental events that might be involved in T-cell lineage fate determination, including the properties of possible thymus settling progenitors, their homing into the thymus, and their T-cell lineage specification and commitment. PMID:20969581

  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. 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

  1. Toeplitz determinants with merging singularities

    E-print Network

    T. Claeys; I. Krasovsky

    2014-10-28

    We study asymptotic behavior for determinants of $n\\times n$ Toeplitz matrices corresponding to symbols with two Fisher-Hartwig singularities at the distance $2t\\ge0$ from each other on the unit circle. We obtain large $n$ asymptotics which are uniform for $0

  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. 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

  4. Nondestructive Determination of Bond Strength

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Although many nondestructive techniques have been applied to detect disbonds in adhesive joints, no absolutely reliable nondestructive method has been developed to detect poor adhesion and evaluate the strength of bonded joints prior to the present work which used nonlinear ultrasonic methods to investigate adhesive bond cure conditions. Previously, a variety of linear and nonlinear ultrasonic methods with water coupling had been used to study aluminum-adhesive-aluminum laminates, prepared under different adhesive curing conditions, for possible bond strength determination. Therefore, in the course of this research effort, a variety of finite-amplitude experimental methods which could possibly differentiate various cure conditions were investigated, including normal and oblique incidence approaches based on nonlinear harmonic generation as well as several non-collinear two-wave interaction approaches. Test samples were mechanically scanned in various ways with respect to the focus of a transmitting transducer operated at several variable excitation frequencies and excitation levels. Even when powerful sample-related resonances were exploited by means of a frequency scanning approach, it was very difficult to isolate the nonlinear characteristics of adhesive bonds. However, a multi-frequency multi-power approach was quite successful and reliable. Ultrasonic tone burst signals at increasing power levels, over a wide frequency range, were transmitted through each bond specimen to determine its excitation dependent nonlinear harmonic resonance behavior. Relative amplitude changes were observed particularly in the higher harmonic spectral data and analyzed using a local displacement and strain analysis in the linear approximation. Two analysis approaches of the excitation-dependent data at specific resonances were found to be quite promising. One of these approaches may represent a very robust algorithm for classifying an adhesive bond as being properly cured or not. Another approach, in addition to differentiation between various cure conditions, may even provide information with respect to the bond strength. Several technical papers were published during the course of this research and a summary is presented in the Ph.D. dissertation of Tobias P. Berndt, a graduate student financially supported by this NASA Grant.

  5. Ballistic projectile trajectory determining system

    DOEpatents

    Karr, T.J.

    1997-05-20

    A computer controlled system determines the three-dimensional trajectory of a ballistic projectile. To initialize the system, predictions of state parameters for a ballistic projectile are received at an estimator. The estimator uses the predictions of the state parameters to estimate first trajectory characteristics of the ballistic projectile. A single stationary monocular sensor then observes the actual first trajectory characteristics of the ballistic projectile. A comparator generates an error value related to the predicted state parameters by comparing the estimated first trajectory characteristics of the ballistic projectile with the observed first trajectory characteristics of the ballistic projectile. If the error value is equal to or greater than a selected limit, the predictions of the state parameters are adjusted. New estimates for the trajectory characteristics of the ballistic projectile are made and are then compared with actual observed trajectory characteristics. This process is repeated until the error value is less than the selected limit. Once the error value is less than the selected limit, a calculator calculates trajectory characteristics such a the origin and destination of the ballistic projectile. 8 figs.

  6. Extractive Spectrophotometric Determination of Ambrisentan

    PubMed Central

    Kumar, Namasani Santhosh; Rani, Avula Prameela; Visalakshi, Telu; Sekharan, Chandra Bala

    2013-01-01

    Purpose: Ambrisentan (ABS) is an antihypertensive drug used in the treatment of pulmonary atrial hypertension. The survey of literature for ABS revealed only two spectrophotometric methods for its quantification. The reported methods lack the sensitivity. This study is aimed at developing two sensitive extractive spectrophotometric methods for the determination of ABS in bulk and in tablets. Methods: The proposed methods are based on the formation of colored chloroform extractable ion-pair complexes of ABS with methylene blue (MB method) and safranine O (SO method) in buffered solution at pH 9.8. The extracted complexes showed maximum absorbance at 525 and 515 nm for methylene blue and safranine O, respectively. Results: In both the methods, the calibration curve was linear from 1–15 µg mL-1 of drug. Apparent molar absorpitivities were 1.7911 x 105, 2.3272 x 105 L mol-1 cm-1; Sandell’s sensitivities were 0.0215, 0.0162 µg cm-2; LOD were 0.182, 0.175 µg mL-1; LOQ were 0.551, 0.531 µg mL-1 for methods MB and SO, respectively. The relative standard deviation and percent recovery ranged from 0.206–1.310% and 99.0–101.5%, respectively. Conclusion: The results demonstrate that the proposed methods are sensitive, precise, accurate and inexpensive. These methods can easily be used for the assay of ABS in quality control laboratories. PMID:24312841

  7. Determinants of children's eating behavior.

    PubMed

    Scaglioni, Silvia; Arrizza, Chiara; Vecchi, Fiammetta; Tedeschi, Sabrina

    2011-12-01

    Parents have a high degree of control over the environments and experiences of their children. Food preferences are shaped by a combination of genetic and environmental factors. This article is a review of current data on effective determinants of children's eating habits. The development of children's food preferences involves a complex interplay of genetic, familial, and environmental factors. There is evidence of a strong genetic influence on appetite traits in children, but environment plays an important role in modeling children's eating behaviors. Parents use a variety of strategies to influence children's eating habits, some of which are counterproductive. Overcontrol, restriction, pressure to eat, and a promise of rewards have negative effects on children's food acceptance. Parents' food preferences and eating behaviors provide an opportunity to model good eating habits. Satiety is closely related to diet composition, and foods with low energy density contribute to prevent overeating. Parents should be informed about the consequences of an unhealthy diet and lifestyle and motivated to change their nutritional habits. Parents should be the target of prevention programs because children model themselves on their parents' eating behaviors, lifestyles, eating-related attitudes, and dissatisfaction regarding body image. Pediatricians can have an important role in the prevention of diet-related diseases. Informed and motivated parents can become a model for children by offering a healthy, high-satiety, low-energy-dense diet and promoting self-regulation from the first years of life. PMID:22089441

  8. Determining GPS average performance metrics

    NASA Technical Reports Server (NTRS)

    Moore, G. V.

    1995-01-01

    Analytic and semi-analytic methods are used to show that users of the GPS constellation can expect performance variations based on their location. Specifically, performance is shown to be a function of both altitude and latitude. These results stem from the fact that the GPS constellation is itself non-uniform. For example, GPS satellites are over four times as likely to be directly over Tierra del Fuego than over Hawaii or Singapore. Inevitable performance variations due to user location occur for ground, sea, air and space GPS users. These performance variations can be studied in an average relative sense. A semi-analytic tool which symmetrically allocates GPS satellite latitude belt dwell times among longitude points is used to compute average performance metrics. These metrics include average number of GPS vehicles visible, relative average accuracies in the radial, intrack and crosstrack (or radial, north/south, east/west) directions, and relative average PDOP or GDOP. The tool can be quickly changed to incorporate various user antenna obscuration models and various GPS constellation designs. Among other applications, tool results can be used in studies to: predict locations and geometries of best/worst case performance, design GPS constellations, determine optimal user antenna location and understand performance trends among various users.

  9. Geographic Determinants of Chinese Urbanization

    NASA Astrophysics Data System (ADS)

    Mccord, G. C.; Christensen, P.

    2011-12-01

    In the first years of the 21st century, the human race became primarily urban for the first time in history. With countries like India and China rapidly undergoing structural change from rural agricultural-based economies to urbanized manufacturing- and service-based economies, knowing where the coming waves of urbanization will occur would be of interest for infrastructure planning and for modeling consequences for ecological systems. We employ spatial econometric methods (geographically weighted regression, spatial lag models, and spatial errors models) to estimate two determinants of urbanization in China. The first is the role of physical geography, measured as topography-adjusted distance to major ports and suitability of land for agriculture. The second is the spatial agglomeration effect, which we estimate with a spatial lag model. We find that Chinese urbanization between 1990 and 2000 exhibited important spatial agglomeration effects, as well as significant explanatory power of nearby agricultural suitability and distance to ports, both in a nationwide model and in a model of local regression estimates. These results can help predict the location of new Chinese urbanization, and imply that climate change-induced changes in agricultural potential can affect the spatial distribution of urban areas.

  10. Genetic determinants of neuroglobin transcription

    PubMed Central

    Wang, R; Halper-Stromberg, E; Szymanski-Pierce, M; Bassett, SS; Avramopoulos, D

    2014-01-01

    Neuroglobin (NGB) is a neuron specific vertebrate globin shown to protect against hypoxia, ischemia, oxidative stress and the toxic effects of Amyloid-beta. Following on our and others' results highlighting the importance of NGB expression in disease we searched for genetic determinants of its expression. We found that a microRNA expressed with the NGB transcript shows significant target enrichments in the angiogenesis pathway and the Alzheimer disease / presenilin pathway. Using reporter constructs we identified potential promoter/enhancer elements between the transcription start site and 1142 bp upstream. Using 184 post mortem temporal lobe samples we replicated the reported negative effect of age, and after genotyping tagging SNPs we found one (rs981471) showing a significant correlation with the gene’s expression and another (rs8014408) showing an interaction with age, the rare C allele being correlated with higher expression and faster decline. The two SNPs are towards the 3' end of NGB within the same LD block, 52 Kb apart and modestly correlated (r2 = 0.5). Next generation sequencing of the same 184 temporal lobe samples and 79 confirmed AD patients across the entire gene region (including >12 Kb on the 3’ and 5’ flank) revealed limited coding variation, suggesting purifying selection of NGB, but did not identify regulatory or disease associated rare variants. A dinucleotide repeat in intron 1 with extensive evidence of functionality showed interesting but inconclusive results, as it was not amenable to further molecular analysis. PMID:24362753

  11. Discovering determinants influencing faith community nursing practice.

    PubMed

    Ziebarth, Deborah Jean

    2014-01-01

    Faith community nursing (FCN) is an important healthcare delivery system for individuals, families, and communities. Determinants are factors that might influence FCN care. A literature review isolated eight determinants that influence practice; however, there are no clear causal relationships linking specific determinants to specific practice changes. Research is needed to assess how determinants influence practice and outcomes, and provide evidence-based solutions to isolate and manage determinants. A Conceptual Model of FCN, Theoretical Definitions and a Diagram of Determinants of FCN Practice are provided. PMID:25296487

  12. [Sociodemographic determinants of women's health].

    PubMed

    Ordonez Gomez, M

    1991-06-01

    This work correlates a series of variables influencing fertility, maternal-child health, and infant mortality from Colombia's 1990 Contraceptive Prevalence, Demography, and Health Survey for 13 regions of Colombia. Causes of death among women aged 15-49 years for 1989 are then examined, and an integrated health program developed by the Association for Family Welfare (PROFAMILIA) for lower income rural and semirural women is described as an example of a successful primary health care program. Colombia's total fertility rate declined from 7.0 in 1965 to 2.9 in 1990. The marital total fertility rate among some subgroups, however, still exceeds 5.0. Fertility is often higher in rural zones, among less educated women, and among those not employed outside the home. The major fertility determinants are family planning, nuptiality, and socioeconomic status, as well as infertility due to lactation and abortion. Family size ideals also play a role. The highest fertility in Colombia today is in the departments of the Atlantic region, in Choco and the Pacific Coast, and in the subregion of the departments of Tolima-Huila and Caqueta. According to the 1990 survey, 66% of women currently in union used a contraceptive method. 62.3% of women in Cali and 61.8% in Bogota used modern methods, compared to only 41% in Tolima-Huila-Caqueta and 43% in Guajira-Magdalena. About 52% of fertile-aged women in Colombia are currently in union. The region of highest fertility have the lowest ages at 1st sexual relations, 1st union, and birth of 1st child. The 1st birth occurred at an average age of 24 years in Antioquia compared to 20 years in the Atlantic Coast. The regions of highest fertility are also those with the greatest proportion of women in union: 60% in the Atlantic region and in Tolima-Huila-Caqueta but only 46% in Antioquia. Socioeconomic status is a major fertility determinant, working through education and accessibility of family planning services. The correlation between illiteracy and fertility in positive and significant. The 1990 survey indicated that there has been progress since 1986 in the proportion of women obtaining prenatal care and professionally attended at delivery, and that the prevalence of acute respiratory infections and diarrheal diseases among children under 5 has declined. Infant mortality rates have declined as well, but are higher among the youngest and oldest mothers and for higher birth order children and those born in rapid succession. Infant mortality was also highly correlated with accessibility of health care and with socioeconomic status. Abortion and obstetrical causes were the 6th major cause of death among fertile-aged women, accounting for 5.4% of deaths overall. Mortality rates from these causes were much higher in less developed departments, accounting for 9.3% of deaths to the age group in Tolima-Huila-Caqueta, 8.6% in Choco-Cauca-Narino, and 7.1% in Boyaca-Cundinamarca-Meta, compared to 3.3% in the Valle region and 2.8% in Antigua Caldas. PMID:12284196

  13. Clinical determinants of PACS acceptance

    NASA Astrophysics Data System (ADS)

    Saarinen, Allan O.; Youngs, Gayle L.; Haynor, David R.; Loop, John W.

    1990-08-01

    One of the key determinants influencing how successfully a radiology department can convert from a conventional film-based environment to an exclusively digital imaging environment may be how well referring physician members of the hospital staff who are not radiologists endorse this new system. The benefits of Picture Archive and Communication Systems (PACS) to radiologists are becoming widely accepted and documented; however, physicians who interact with the radiology department represent an important user group whose views on PACS are less well understood. The acceptance of PACS by referring physicians (clinicians) may be critical to the overall utility ofPACS as well as a major drivingforce behind why a hospitalpurchases PACS. The degree to which referring physicians support PACS may be dependent upon many factors. This study identifies several aspects through the administration and analysis ofa survey which improve PACS acceptance by nonradiology physicians. It appears the more patients a referring physician sends to the radiology department, the more time a physician spends traveling to andfrom thefllmflle room retrievingfllms, and, the more interested a referring physician is about computers, the higher his interest is in PACS. If a referring physician believes that PACS will save him or her time, will reduce the incidence oflostfilms, or will cause performance of radiology exams or generation of reports to be more efficient, the referring physician appears more likely to support PACS and to make the initial time investment necessary to learn how PACS equipment operates. The factors which cause referring physicians to support PACS are principally: (1) the elimination oflost, misplaced, and checked outfllms, and (2) the elimination oftrips to and from thefile room. The major distractions ofthe technology are: (1) system reliability, and (2) reduced diagnostic capability. While the high cost ofPACS is also a distraction, it is not the predominant concern.

  14. 45 CFR 150.217 - Preliminary determination.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Preliminary determination. 150.217 Section 150.217 Public Welfare DEPARTMENT OF HEALTH AND HUMAN...Failing To Substantially Enforce HIPAA Requirements § 150.217 Preliminary determination. If, at...

  15. 38 CFR 75.116 - Secretary determination.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...determination. (a) Upon receipt of a risk analysis prepared under this subpart...other information contained in the risk analysis to determine whether the data...affected individuals provided in the risk analysis; (4) Whether the...

  16. 38 CFR 75.116 - Secretary determination.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...determination. (a) Upon receipt of a risk analysis prepared under this subpart...other information contained in the risk analysis to determine whether the data...affected individuals provided in the risk analysis; (4) Whether the...

  17. 38 CFR 75.116 - Secretary determination.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...determination. (a) Upon receipt of a risk analysis prepared under this subpart...other information contained in the risk analysis to determine whether the data...affected individuals provided in the risk analysis; (4) Whether the...

  18. 38 CFR 75.116 - Secretary determination.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...determination. (a) Upon receipt of a risk analysis prepared under this subpart...other information contained in the risk analysis to determine whether the data...affected individuals provided in the risk analysis; (4) Whether the...

  19. A determinant of generalized Fibonacci numbers

    E-print Network

    Krattenthaler, Christian

    2012-01-01

    We evaluate a determinant of generalized Fibonacci numbers, thus providing a common generalization of several determinant evaluation results that have previously appeared in the literature, all of them extending Cassini's identity for Fibonacci numbers.

  20. DETERMINING THE STABILITY OF TREATED MUNICIPAL SLUDGES

    EPA Science Inventory

    The objective of this project was to determine the potential for further biological degradation biologically of municipal sludges which have undergone either little or major treatment. A literature survey was conducted to determine the most fruitful approaches, followed by labora...