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1

Thermochemistry of uranium compounds: XVI, Calorimetric determination of the standard molar enthalpy of formation at 298.15 K, low-temperature heat capacity, and high-temperature enthalpy increments of UO{sub 2}(OH){sub 2} {center_dot} H{sub 2}O (schoepite)  

SciTech Connect

Three precise calorimetric methods, viz., low-temperature adiabatic, high-temperatuare drop, and solution-reaction, have been used to determine as a function of temperature the key chemical thermodynamic properties of a pure sample of schoepite, UO{sub 2}(OH){sub 2} {center_dot} H{sub 2}O. The following results have been obtained at the standard reference temperature T = 298.15 K:standard molar enthalpy of formation {Delta}/sub f/H/sub m/{sup 0}(T) = {minus}1825.4 +- 2.1 kJ mol/sup {minus}1/; molar heat capacity C/sub p,m/{sup 0}(T) = 172.07 +- 0.34 JK/sup {minus}1/; and the standard molar entropy S/sub m/{sup 0}(T) = 188.54 +- 0.38 JK/sup {minus}1/ mol/sup {minus}1/. The molar enthalpy increments relative to 298.15 K and the molar heat capacity are given by the polynomials: {H{sub m}{sup 0}(T) {minus} H{sub m}{sup 0}(298.15 K)}/(J mol/sup {minus}1/) = {minus}38209.0 + 84.2375 (T/K) + 0.1472958 (T/K){sup 2} and C/sub p,m/{sup 0}(T)/(JK/sup {minus}1/ mol/sup {minus}1/) = 84.238 + 0.294592 (T/K), where 298.15 K < T < 400 K. The present result for {Delta}/sup f/H/sub m/{sup 0} at 298.15 K has been combined with three other closely-agreeing values from the literature to give a recommended weighted mean {Delta}/sub f/H/sub m/{sup 0} = {minus}1826.4 +- 1.7 kJ mol/sup {minus}1/, from which is calculated the standard Gibbs energy of formation {Delta}/sub f/G/sub m/{sup 0} = {minus}1637.0 +- 1.7 kJ mol/sup {minus}1/ at 298.15 K. Complete thermodynamic properties of schoepite are tabulated from 298.15 to 423.15 K. 19 refs., 6 tabs.

Tasker, I.R.; O`Hare, P.A.G.; Lewis, B.M.; Johnson, G.K.; Cordfunke, E.H.P.

1987-08-01

2

Calorimetric determination of the enzyme activity immobilised on macroporous glass membranes  

Microsoft Academic Search

A direct method for the determination of the catalytic activity of immobilised enzymes by use of a miniaturised calorimeter is presented. The possibilities and advantages of the calorimetric method are demonstrated by investigations with catalase immobilised on macroporous glass membranes as model enzyme. The investigated enzyme carrier systems are characterised by a high catalytic activity, a marked long-term stability and

Hagen Graebner; Regina Hüttl; Gert Wolf

2002-01-01

3

Calorimetric determinations and theoretical calculations of polymorphs of thalidomide  

NASA Astrophysics Data System (ADS)

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

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

2007-09-01

4

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

NASA Astrophysics Data System (ADS)

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

Ornellas, D. L.

1982-04-01

5

Calorimetric determination of fragility in glass forming liquids: T(f) vs. T(g-onset) methods.  

PubMed

The calorimetric determination of the fragility m-index is compared using the T f and T g-onset methods for typical metallic and molecular glass forming systems of Pd39Ni10Cu30P21, glycerol, triacetin and propylene carbonate. The results are evaluated by referring to the standard m-values determined from the kinetic measurements of the viscosity or structural relaxation time in the supercooled liquid regimes. The m-indexes derived from the T f method are found to generally agree well with the kinetic measurements for all the systems. However, a large deviation is shown between the m-indexes calculated with the T g-onset method and the kinetic results for the fragile liquids of triacetin and propylene carbonate, indicating the calorimetric determination of the fragility m-indexes in terms of the T f method produces less uncertainty. PMID:24965151

Chen, Zeming; Li, Zijing; Zhang, Yaqi; Liu, Riping; Tian, Yongjun; Wang, Li-Min

2014-06-01

6

New methodology for simultaneous volumetric and calorimetric measurements: Direct determination of ?p and Cp for liquids under pressure  

NASA Astrophysics Data System (ADS)

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

Casás, L. M.; Plantier, F.; Bessières, D.

2009-12-01

7

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

PubMed

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

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

2014-11-20

8

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

SciTech Connect

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

Casas, L. M. [Departamento de Fisica Aplicada, Facultad de Ciencias Experimentales, Universidad de Vigo, Lagoas Marcosende s/n, 36310 Vigo (Spain); Plantier, F.; Bessieres, D. [Laboratoire de Thermodynamique et Energetique des Fluides Complexes-UMR 5150, Universite de Pau et des Pays de l'Adour, BP 1155, 64013 Pau (France)

2009-12-15

9

Determination of the activation energy spectrum of structural relaxation in metallic glasses using calorimetric and shear modulus relaxation data  

NASA Astrophysics Data System (ADS)

We consider two methods for reconstruction of the activation energy spectra of structural relaxation from calorimetric and shear modulus relaxation data. The methods are based on the assumption that structural relaxation of metallic glasses can be understood as a relaxation change of the concentration of frozen-in defects similar to dumbbell interstitials (interstitialcies) in simple crystals. For three Pd- and Zr-based glasses taken as an example, it is shown that both methods give nearly the same results. We calculated a decrease of the defect concentration and showed that the heat of structural relaxation per defect for all three glasses practically coincides with the theoretical value of the interstitialcy formation enthalpy.

Tsyplakov, A. N.; Mitrofanov, Yu. P.; Makarov, A. S.; Afonin, G. V.; Khonik, V. A.

2014-09-01

10

Intercultural Communication Studies XVI: 3 A Disease That "Has a Woman's Face": The Social Construction  

E-print Network

Intercultural Communication Studies XVI: 3 A Disease That "Has a Woman's Face": The Social of HIV infection because they #12;Intercultural Communication Studies XVI: 3 lack the power to determine be seen in some feminist research in communication which focuses on "how gender is constructed through

Kvasny, Lynette

11

A calorimetric system for metabolic studies of newborn babies  

Microsoft Academic Search

Describes a closed circuit calorimetric system designed to determine the amount of energy required for synthesis of new tissue in a newborn baby. This amount can be estimated from the difference between indirect and calorimetric measurements. The system allows the simultaneous measurement of oxygen consumption, carbon dioxide production, evaporative water loss and heat loss through convection and radiation in newborn

H J Dane; W P J Holland; P J J Sauer; H K A Visser

1985-01-01

12

Calorimetric experiments on social insects  

Microsoft Academic Search

Direct calorimetric experiments on the social insects: honeybees, bumblebees and hornets are described as function of castes, age, number of animals in a group, temperature, sound generation, hibernation and influence of pheromones. Two honeybee subspecies, the European bee Apis mellifera carnica and the Egyptian bee Apis mellifera lamarckii, were compared calorimetrically in their energy metabolism which differed considerably in favour

Ingolf Lamprecht

1997-01-01

13

Calorimetric gas sensor  

DOEpatents

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.

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

14

Calorimetric gas sensor  

DOEpatents

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.

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

1998-11-10

15

PREFACE: Symmetries in Science XVI  

NASA Astrophysics Data System (ADS)

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

2014-10-01

16

An automated calorimetric method of loss measurement in electrical machines  

NASA Astrophysics Data System (ADS)

Traditionally the losses dissipated in an electrical machine have been determined from the difference between the measured input and output powers. However, the achievable accuracy is limited by the uncertainty of measurement errors, particularly if the machine is supplied with distorted voltage and current waveforms. Therefore, a more appropriate approach is to employ a calorimetric method in which the losses are determined by direct measurement of the dissipated heat. This paper describes the control and instrumentation of such an automated calorimetric system which has been commissioned to accomodate machines of up to 75 kW rating, and in which losses can be measured to an accuracy better than 10 W.

Baholo, B.; Mellor, P. H.; Howe, D.; Birch, T. S.

1994-05-01

17

XVI Encontro de Economia da Regio Sul -ANPEC SUL 2013 XVI Encontro de Economia da Regio Sul  

E-print Network

XVI Encontro de Economia da Região Sul - ANPEC SUL 2013 1 XVI Encontro de Economia da Região Sul Programa de Pós Graduação em Desenvolvimento Econômico Curitiba - PR #12;XVI Encontro de Economia da Região/UFPR) Secretárias do PPGDE Aurea Koch Ivone Polo #12;XVI Encontro de Economia da Região Sul - ANPEC SUL 2013 3

Paraná, Universidade Federal do

18

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

E-print Network

Context: The commonly used extinction laws of Cardelli et al. (1989) have limitations that, among other issues, hamper the determination of the effective temperatures of O and early B stars from optical+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+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+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 uncertain...

Apellániz, J Maíz; 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

2014-01-01

19

Calorimetric assay of minor actinides  

SciTech Connect

This paper reviews the principles of calorimetric assay and evaluates its potential application to the minor actinides (U-232-4, Am-241, Am- 243, Cm-245, Np-237). We conclude that calorimetry and high- resolution gamma-ray isotopic analysis can be used for the assay of minor actinides by adapting existing methodologies for Pu/Am-241 mixtures. In some cases, mixtures of special nuclear materials and minor actinides may require the development of new methodologies that involve a combination of destructive and nondestructive assay techniques.

Rudy, C.; Bracken, D.; Cremers, T.; Foster, L.A.; Ensslin, N.

1996-12-31

20

Calorimetric system and method  

DOEpatents

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.

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

1998-09-15

21

Calorimetric system and method  

DOEpatents

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).

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

1998-09-15

22

Radiation beam calorimetric power measurement system  

DOEpatents

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.

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

1992-01-01

23

Air Pollution XVI 247 Emissions of Nitrogen Dioxide from Modern  

E-print Network

Air Pollution XVI 247 Emissions of Nitrogen Dioxide from Modern Diesel Vehicles G.A. Bishop and D;Air Pollution XVI 248 The DPF is an extremely effective means to achieve particle reduction goals increase, are of concern to air pollution photochemistry because NO2 leads directly, through solar

Denver, University of

24

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

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

25

Titration calorimetric determination of the pairwise interaction parameters of glycerol, D-threitol, mannitol, and D-glucitol in dilute aqueous solutions  

Microsoft Academic Search

Enthalpic pairwise interaction parameters, hjj, were determined by titration calorimetry at 25°C for dilute solutions of glycerol, D-threitol, manitol, and D-glucitol in water. The parameters for these and other polyols conform to the expression hjj (J-kg-1)=145+135nOH-21.5nOH2-41.7dl2-160.5ndlld, where nOH=nC is the number of hydroxyl groups (carbon atoms), ndl is the number of dl configuration of a vicinal pair of OH-groups, and

L. Giorgio Soldi; Yizhak Marcus; Michael J. Blandamer; Paul M. Cullis

1995-01-01

26

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

NASA Astrophysics Data System (ADS)

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

Kojitani, Hiroshi; Akaogi, Masaki

1997-12-01

27

2008 Site environmental report xvi the environmental and Waste Management  

E-print Network

Group environmental restoration project Division information Services Division media & Communications2008 Site environmental report xvi DRAFT the environmental and Waste Management services Division Lagattolla not pictured) the environmental information Management services group (Back row, left to right

28

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

29

Selection of non-destructive assay methods: Neutron counting or calorimetric assay?  

SciTech Connect

The transition of DOE facilities from production to D&D has lead to more measurements of product, waste, scrap, and other less attractive materials. Some of these materials are difficult to analyze by either neutron counting or calorimetric assay. To determine the most efficacious analysis method, variety of materials, impure salts and hydrofluorination residues have been assayed by both calorimetric assay and neutron counting. New data will be presented together with a review of published data. The precision and accuracy of these measurements are compared to chemistry values and are reported. The contribution of the gamma ray isotopic determination measurement to the overall error of the calorimetric assay or neutron assay is examined and discussed. Other factors affecting selection of the most appropriate non-destructive assay method are listed and considered.

Cremers, T.L.; Wachter, J.R.

1994-08-01

30

Measurement of the calorimetric energy scale in MINOS  

SciTech Connect

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}).

Hartnell, Jeffrey J.; /Oxford U.

2005-06-01

31

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

PubMed

Calorimetric data can provide a basis for determining potential hazards in reactions, storage, and transportation of process chemicals. This work provides calorimetric data for the thermal decomposition behavior in air of 50wt.% hydroxylamine/water (HA), both with and without added stabilizers, which was measured in closed cells with an automatic pressure tracking adiabatic calorimeter (APTAC). Among the data provided are onset temperatures, reaction order, activation energies, pressures of noncondensable products, thermal stability at 100 degrees C, and the effect of HA storage time. Discussed also are the catalytic effects of carbon steel, stainless steel, stainless steel with silica coating, inconel, titanium, and titanium with silica coating on the reaction self-heat rates and onset temperatures. In borosilicate glass cells, HA was relatively stable at temperatures up to 133 degrees C, where the HA decomposition self-heat rate reached 0.05 degrees C/min. The added stabilizers appeared to reduce HA decomposition rates in glass cells and at ambient temperatures. The tested metals and metal surfaces coated with silica acted as catalysts to lower the onset temperatures and increase the self-heat rates. PMID:11165058

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

2001-03-19

32

The calorimetric measurement of low energy brachytherapy sources  

NASA Astrophysics Data System (ADS)

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

Aus, Robert John

33

ARTICLE XVI PART I. The Workload of the Faculty  

E-print Network

75 ARTICLE XVI WORKLOAD PART I. The Workload of the Faculty The maximum teaching load for tenured and tenure-track faculty is 18 credit hours or equivalent contact hours as defined by the college workload as defined by the college workload committee for research-active faculty or faculty who submit a research

Massachusetts at Lowell, University of

34

Calorimetric thermobarometry of experimentally shocked quartz  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

35

Calorimetric Thermometry of Meteoritic Troilite: Early Reconnaissance  

NASA Astrophysics Data System (ADS)

Troilite (FeS) exhibits two solid-state phase transformations, which, according to conventional thermodynamic literature [1,2], occur at 411 +- 3 K (alpha/beta) and 598 +- 3 K (beta/gamma). In principal, the thermal history of a particular troilite sample might be expected to impart structural or strain characteristics that could be measured upon experimental inducement of the phase transformations. To investigate that possibility, we applied differential scanning calorimetry (DSC) to determine the temperatures and enthalpy changes for phase transitions of various troilite samples subjected to controlled heating [3]. Post-heating residues were prepared as polished grain mounts and petrologically characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS). Troilite grains separated from the Mundrabilla (octahedrite), PAT91501 (L7 chondrite), and EET83213 (L3 chondrite) meteorites were compared with terrestrial troilite from an ultramafic complex in Del Norte Co., California. Both the alpha/beta and beta/gamma transitions were easily measured by DSC applied to samples on the order of 5 milligrams. Extrapolated-onset temperatures (the DSC approximation of equilibrium transition temperatures) for the alpha/beta transition display a systematic progression as follows: Mundrabilla, PAT91501, EET83213, Del Norte (Fig. 1). At least for Mundrabilla, PAT91501, and Del Norte, there also exists an apparent correlation of transition enthalpy with onset temperature (Fig. 1). (Enthalpy measurements for EET83213 troilite were systematically low, by dilution effects from admixed Ni-Fe metal, and require correction before such comparison.) Although Mundrabilla troilite contains on the order of 1 wt% Cr, and some grains of PAT91501 troilite contain on the order of 1 wt% Ni, it is doubtful that compositional differences can fully account for the measured differences in thermodynamic properties. Instead, it is likely that first-order differences are the consequence of different thermal histories. Multiple samples of Del Norte troilite were used to determine the influence of laboratory-scale thermal histories on DSC signatures by heating and cooling each sample under different programmed conditions. In reconnaissance experiments, maximum temperature achieved during heat treatment appears to be more influential than does either the time maintained at temperature or the heating/cooling rate. The experimentally measured alpha/beta onset temperature shows a systematic decline with maximum temperature achieved during prior heating, suggesting that high onset temperatures are indicative of low maximum temperatures in the natural histories of the troilite samples. That trend is at least qualitatively consistent with the petrologic rankings of the meteorites in which troilite from the relatively unmetamorphosed L3 chondrite shows a higher onset temperature than does troilite from either the highly metamorphosed L7 chondrite or the octahedrite. Additional work should define the limits of a quantitative calibration that might ultimately permit derivation of meteorite thermal histories by calorimetric thermometry of troilite. Samples were kindly provided by E. R. D. Scott (Mundrabilla), C. B. Moore (Del Norte), and the Meteorite Working Group (PAT91501; EET83213 powder from E. Jarosewich). References: [1] Chase M. W. Jr. et al. (1985) JANAF Thermochemical Tables, 3rd ed., 1194. [2] Robie R. A. et al. (1979) Geol. Surv. Bull. 1452, 125. [3] Allton J. H. and Gooding J. L. (1993) LPS XXIV, 21-22. Fig. 1, which appears here in the hard copy, shows the thermodynamics of troilite alpha/beta phase transformations measured by DSC during first-heat cycles.

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

1993-07-01

36

Nanoclay modified polycarbonate blend nanocomposites: Calorimetric and mechanical properties  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

37

Calorimetric Studies at the New Hydrogen Energy Laboratory in Japan  

Microsoft Academic Search

Experiments using China Lake type calorimetric cells produced excess power in three out of three experiments and no excess power in three control studies. A detailed analysis is presented for two experiments using the China Lake cells. Anomalous thermistor signals in Cell A suggest the emission of electromagnetic radiation from the active palladium cathode. Experiments in Fleischmann-Pons type calorimetric cells

Melvin H. Miles

2000-01-01

38

NISTIR 5732 Calorimetric and Visual Measurements of R123  

E-print Network

of nucleate boiling were also investigated. The boiling was visually recorded with 16 mm high speed filmNISTIR 5732 Calorimetric and Visual Measurements of R123 Pool Boiling on Four Enhanced Surfaces #12;NISTIR 5732 Calorimetric and Visual Measurements of R123 Pool Boiling on Four Enhanced Surfaces

Oak Ridge National Laboratory

39

EDITORIAL: Special issue: CAMOP MOLEC XVI  

NASA Astrophysics Data System (ADS)

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

Ascenzi, Daniela; Franceschi, Pietro; Tosi, Paolo

2007-09-01

40

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

NASA Astrophysics Data System (ADS)

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

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

2009-07-01

41

Amperometry with two polarizable electrodes. XVI  

Microsoft Academic Search

Conditions for the magnesium determination in alkaline solution by EDTA titration with biamperometric indication were examined. The most preferable pH range was found to be above 9.6. A reliable determination can be carried out in the presence of Ca, Ni, Cu and Co up to the ratio of 1:1. In the case of higher concentrations of Cu and Ni masking

Jan Vorlí?ek; Milan Fara; František Vydra

1968-01-01

42

Adiabatic Heat of Hydration Calorimetric Measurements for Reference Saltstone Waste  

SciTech Connect

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.

Bollinger, James

2006-01-12

43

The CALorimetric Electron Telescope, CALET, Mission  

NASA Astrophysics Data System (ADS)

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.

Torii, Shoji

44

Calorimetric Study of Diluted Spin Ice Materials  

NASA Astrophysics Data System (ADS)

Spin ice materials Dy2Ti2O7 and Ho2Ti2O7 have been the subject of ongoing interest for over ten years. The cooperative magnetic ground state can be mapped onto the proton disordered ground state in water ice, and its residual entropy follows the same Pauling's estimate. Interestingly it was found in a previous study that, upon dilution of the magnetic rare earth ions Dy^3+ and Ho^3+ by non-magnetic substitutes Y^3+, the residual entropy depends non-monotonically on the dilution level. In this work we investigate through Monte Carlo simulations microscopic models to account quantitatively for the calorimetric experimental measurements, and thus also the residual entropies as a function of dilution. Features of the dilution physics in the specific heat are captured quantitatively by the microscopic models and the interplay between dilution and frustration is understood on the basis of a Bethe lattice calculation. The effect of the dipolar interactions between magnetic spins are exposed numerically for various dilution concentrations. Our work explains the previous discrepancy of the residual entropy between different species of rare earth ions and the generalized Pauling's estimate.

Lin, Taoran; Ke, Xianglin; Thesberg, Mischa; Schiffer, Peter; Melko, Roger; Gingras, Michel

2012-02-01

45

Planck 2013 results. XVI. Cosmological parameters  

NASA Astrophysics Data System (ADS)

This paper presents the first cosmological results based on Planck measurements of the cosmic microwave background (CMB) temperature and lensing-potential power spectra. We find that the Planck spectra at high multipoles (? ? 40) are extremely well described by the standard spatially-flat six-parameter ?CDM cosmology with a power-law spectrum of adiabatic scalar perturbations. Within the context of this cosmology, the Planck data determine the cosmological parameters to high precision: the angular size of the sound horizon at recombination, the physical densities of baryons and cold dark matter, and the scalar spectral index are estimated to be ?? = (1.04147 ± 0.00062) × 10-2, ?bh2 = 0.02205 ± 0.00028, ?ch2 = 0.1199 ± 0.0027, and ns = 0.9603 ± 0.0073, respectively(note that in this abstract we quote 68% errors on measured parameters and 95% upper limits on other parameters). For this cosmology, we find a low value of the Hubble constant, H0 = (67.3 ± 1.2) km s-1 Mpc-1, and a high value of the matter density parameter, ?m = 0.315 ± 0.017. These values are in tension with recent direct measurements of H0 and the magnitude-redshift relation for Type Ia supernovae, but are in excellent agreement with geometrical constraints from baryon acoustic oscillation (BAO) surveys. Including curvature, we find that the Universe is consistent with spatial flatness to percent level precision using Planck CMB data alone. We use high-resolution CMB data together with Planck to provide greater control on extragalactic foreground components in an investigation of extensions to the six-parameter ?CDM model. We present selected results from a large grid of cosmological models, using a range of additional astrophysical data sets in addition to Planck and high-resolution CMB data. None of these models are favoured over the standard six-parameter ?CDM cosmology. The deviation of the scalar spectral index from unity isinsensitive to the addition of tensor modes and to changes in the matter content of the Universe. We find an upper limit of r0.002< 0.11 on the tensor-to-scalar ratio. There is no evidence for additional neutrino-like relativistic particles beyond the three families of neutrinos in the standard model. Using BAO and CMB data, we find Neff = 3.30 ± 0.27 for the effective number of relativistic degrees of freedom, and an upper limit of 0.23 eV for the sum of neutrino masses. Our results are in excellent agreement with big bang nucleosynthesis and the standard value of Neff = 3.046. We find no evidence for dynamical dark energy; using BAO and CMB data, the dark energy equation of state parameter is constrained to be w = -1.13-0.10+0.13. We also use the Planck data to set limits on a possible variation of the fine-structure constant, dark matter annihilation and primordial magnetic fields. Despite the success of the six-parameter ?CDM model in describing the Planck data at high multipoles, we note that this cosmology does not provide a good fit to the temperature power spectrum at low multipoles. The unusual shape of the spectrum in the multipole range 20 ? ? ? 40 was seen previously in the WMAP data and is a real feature of the primordial CMB anisotropies. The poor fit to the spectrum at low multipoles is not of decisive significance, but is an "anomaly" in an otherwise self-consistent analysis of the Planck temperature data.

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

2014-11-01

46

Calorimetric Studies at the New Hydrogen Energy Laboratory in Japan  

NASA Astrophysics Data System (ADS)

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

Miles, Melvin H.

2000-03-01

47

Application of a downstream calorimetric probe to reactive plasma  

SciTech Connect

We explore the application of calorimetric probe located downstream from the plasma zone. By positioning the probe in a downstream location, the probe signal can be correlated with the integral energy flux carried by the effluent species as they propagate downstream from the plasma zone. Because the integral energy flux channeled downstream depends on the plasma conditions, it is possible to infer the plasma conditions from the probe response even though the probe is located away from the plasma zone. A calorimetric probe, based on resistance-temperature detector principle, adequate for fluorine plasma exposure is constructed. Probe operation is demonstrated for NF{sub 3}-Ar plasmas.

Chen, I.-S.; Neuner, Jeffery W.; Chen, Philip S.H.; Welch, James J.; DiMeo, Frank Jr. [ATMI, 7 Commerce Drive, Danbury, Connecticut 06810 (United States)

2005-12-05

48

Application of a downstream calorimetric probe to reactive plasma  

NASA Astrophysics Data System (ADS)

We explore the application of calorimetric probe located downstream from the plasma zone. By positioning the probe in a downstream location, the probe signal can be correlated with the integral energy flux carried by the effluent species as they propagate downstream from the plasma zone. Because the integral energy flux channeled downstream depends on the plasma conditions, it is possible to infer the plasma conditions from the probe response even though the probe is located away from the plasma zone. A calorimetric probe, based on resistance-temperature detector principle, adequate for fluorine plasma exposure is constructed. Probe operation is demonstrated for NF3-Ar plasmas.

Chen, Ing-Shin; Neuner, Jeffery W.; Chen, Philip S. H.; Welch, James J.; DiMeo, Frank

2005-12-01

49

Stability parameters for one-step mechanism of irreversible protein denaturation: a method based on nonlinear regression of calorimetric peaks with nonzero deltaCp.  

PubMed

Thermal transitions of many proteins have been found to be calorimetrically irreversible and scan-rate dependent. Calorimetric determinations of stability parameters of proteins which unfold irreversibly according to a first-order kinetic scheme have been reported. These methods require the approximation that the increase in heat capacity upon denaturation deltaCp is zero. A method to obtain thermodynamic parameters and activation energy for the two-state irreversible process N --> D from nonlinear fitting to calorimetric traces is proposed here. It is based on a molar excess heat capacity function which considers irreversibility and a nonzero constant deltaCp. This function has four parameters: (1) temperature at which the calorimetric profile reaches its maximal value (Tm), (2) calorimetric enthalpy at Tm (deltaHm), (3) deltaCp, and (4) activation energy (E). The thermal irreversible denaturation of subtilisin BPN' from Bacillus amyloliquefaciens was studied by differential scanning calorimetry at pH 7.5 to test our model. Transitions were found to be strongly scanning-rate dependent with a mean deltaCp value of 5.7 kcal K(-1)mol(-1), in agreement with values estimated by accessible surface area and significantly higher than a previously reported value. PMID:15113687

Arroyo-Reyna, Alfonso; Tello-Solís, Salvador R; Rojo-Domínguez, Arturo

2004-05-15

50

Calorimetric glass transition explained by hierarchical dynamic facilitation  

E-print Network

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

Garrahan, Juan P.

51

Isoperibolic Calorimetric Measurements of the Fleischmann-Pons Effect  

Microsoft Academic Search

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

Melvin H. Miles; Martin Fleischmann

52

Differential scanning calorimetric investigations of naturally dehydrated aqueous sucrose solutions  

Microsoft Academic Search

Differential scanning calorimetric investigations have been conducted on sucrose solutions for temperatures T 92, the room temperature phase is amorphous, as indicated by its x-ray diffraction pattern. A melting transition is reported for the first time for these

A. S. Paranjpe

1998-01-01

53

Application of a downstream calorimetric probe to reactive plasma  

Microsoft Academic Search

We explore the application of calorimetric probe located downstream from the plasma zone. By positioning the probe in a downstream location, the probe signal can be correlated with the integral energy flux carried by the effluent species as they propagate downstream from the plasma zone. Because the integral energy flux channeled downstream depends on the plasma conditions, it is possible

Ing-Shin Chen; Jeffery W. Neuner; Philip S. H. Chen; James J. Welch; Frank Jr. DiMeo

2005-01-01

54

Thermodynamic properties of chlorite and berthierine derived from calorimetric measurements  

NASA Astrophysics Data System (ADS)

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.

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

55

Calorimetric and computational study of the thermochemistry of phenoxyphenols.  

PubMed

Thermodynamic properties of 3- and 4-phenoxyphenol have been determined by using a combination of calorimetric and effusion techniques as well as by high-level ab initio molecular orbital calculations. The standard (p° = 0.1 MPa) molar enthalpies of formation in the condensed and gas states, ?(f)H(m)°(cr or l) and ?(f)H(m)°(g), at T = 298.15 K, of 3- and 4-phenoxyphenol were derived from their energies of combustion in oxygen, measured by a static bomb calorimeter, and from the enthalpies of vaporization or sublimation derived respectively by Calvet microcalorimetry for the 3-phenoxyphenol and by Knudsen effusion technique for the 4-phenoxyphenol. The theoretically estimated gas-phase enthalpies of formation were calculated from high-level ab initio molecular orbital calculations at the G3(MP2)//B3LYP level of theory. Furthermore, this composite approach was also used to obtain information about the gas-phase acidities, gas-phase basicities, proton and electron affinities, adiabatic ionization enthalpies, and, finally, O?H bond dissociation enthalpies. The good agreement between the G3MP2B3-derived values and the experimental gas-phase enthalpies of formation for the 3- and 4-phenoxyphenol gives confidence to the estimate concerning the 2-phenoxyphenol isomer, which was not experimentally studied, and to the estimates concerning the radical and the anion. Additionally, the experimental values of gas-phase enthalpies of formation were also compared with estimates based on the empirical scheme developed by Cox. PMID:21486007

Ribeiro da Silva, Manuel A V; Lobo Ferreira, Ana I M C; Cimas, Álvaro

2011-05-20

56

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)

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°?.

Kalna?s, J.; Grehovs, V.; Mežinskis, G.; Bidermanis, L.

2013-10-01

57

Theoretical study and design of a new calorimetric tunnel  

NASA Astrophysics Data System (ADS)

An enlargement of the Pilsner R&D park consisted of several new buildings is running nowadays. The University of West Bohemia, New technology Research centre, will be using one of the buildings also for hosting the calorimetric tunnel. With respect to our experience with currently operated calorimetric tunnel with lower power and smaller size, a new tunnel of higher power and better parameters was designed. The tunnel was proposed on the base of 10 analytical calculations respecting wide range of operational regimes and possible different target applications. Together with analytical computations, also some simplified CFD simulations were done. These simulations gave us information about the flow field in the tunnel and especially in the measuring area. Some non- standardized parts of the tunnel were proposed, designed and verified with the use of CFD. The tunnel design together with its parameters and results of CFD analysis are presented in the paper.

Sedlá?ek, Jan; K?ourek, Jind?ích; K?s, Michal

2012-04-01

58

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

59

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

...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...made to any State under title I, IV-A, X, XIV or XVI of the Social...

2012-10-01

60

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

...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...made to any State under title I, IV-A, X, XIV or XVI of the Social...

2013-10-01

61

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

...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...assistance programs under titles I, IV-A, X, XIV and XVI of the Social Security Act...made to any State under title I, IV-A, X, XIV or XVI of the Social...

2011-10-01

62

A speech given in the precence of His Majesty, King Karl XVI Gustav and her majesty Queen Silvia  

E-print Network

A speech given in the precence of His Majesty, King Karl XVI Gustav and her majesty Queen Silvia in the presence of His Majesty, King Karl XVI Gustav, her majesty Queen Silvia and this distin- guished company particularly happy 1 #12;that Dr. Marcus Wallenberg's outstanding and unique position in financial

Tomppo, Erkki

63

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

Federal Register 2010, 2011, 2012, 2013

...SSA-2011-0057] Social Security Ruling 11-1p; Titles II and XVI: Procedures for Handling Requests...when you have a pending claim of the same title and benefit type in our administrative...Security. Policy Interpretation Ruling Titles II and XVI: Procedures for Handling...

2011-07-28

64

Electron impact excitation rates for transitions in beryllium-like P XII, S XIII, Cl XIV, Ar XV and K XVI  

NASA Astrophysics Data System (ADS)

The R-matrix electron excitation rates determined by Berrington et al. (1985) for C III, O V, Ne VII, and Si XI and by Dufton et al. (1983) for Ca XVII are used to interpolate the rates for Be-like P XII, S XIII, Cl XIV, Ar XV, and K XVI. The results are presented in a series of tables and briefly characterized. The accuracy of the present findings is estimated as + or - 10 percent within 0.8 dex of log Tmax, where Tmax is the temperature of maximum fractional abundance for ionization equilibrium. The applicability of the results to the diagnostics of astrophysical and laboratory plasmas is indicated.

Keenan, F. P.

1988-01-01

65

Two calorimetrically distinct parts of the dynamic glass transition  

NASA Astrophysics Data System (ADS)

Although known for more than thirty years, the physical nature of the glass-transition crossover region is still an open question. Heat capacity spectroscopy experiments in the crossover region of poly(n-hexyl methacrylate) are presented which indicate, for the first time, that the dynamic glass transition consists of two separate parts in series: A thermorheologically rather simple high-temperature part (called a-process) and a low-temperature part with increasing molecular cooperativity on the nanometer scale (?-process). The calorimetric experiments show, surprisingly, a decline of the a process and a separate onset of the ?-process.

Beiner, M.; Kahle, S.; Hempel, E.; Schröter, K.; Donth, E.

1998-11-01

66

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

E-print Network

SPIE Proceedings, Ophthalmic Technologies XVI, vol. 6138 (2006) 1 Noninvasive Dosimetry and the lack of immediately observable outcome of the therapy, a real-time dosimetry is highly desirable. We-time monitoring and dosimetry of TTT. A 795nm laser was applied in rabbit eyes for 60 seconds using a 0.86mm

Palanker, Daniel

67

Proceedings SPIE, Ophthalmic Technologies XVI, SPIE vol. 6138 (2006) Plasma-Mediated Transfection of RPE  

E-print Network

Proceedings SPIE, Ophthalmic Technologies XVI, SPIE vol. 6138 (2006) 1 Plasma-Mediated Transfection transfection of RPE without visible damage to the retina. Gene expression was quantified and monitored using bioluminescence (luciferase) and fluorescence (GFP) imaging. Transfection efficiency of RPE with this new

Palanker, Daniel

68

Volume XVI, No. 3 A publication of the U.S. Army Installation Management Agency  

E-print Network

Volume XVI, No. 3 A publication of the U.S. Army Installation Management Agency May/June 2004 U.S/June 2004 Public Works Digest is an unofficial publication of the U.S. Army Installa- tion Management Agency of the Department of the Army. Address mail to: U.S. Army Installation Management Agency 2511 Jefferson Davis

US Army Corps of Engineers

69

Volume XVI, No. 6 A publication of the U.S. Army Installation Management Agency  

E-print Network

Volume XVI, No. 6 A publication of the U.S. Army Installation Management Agency November/December 2004 U.S. Army Installation Management Agency In this issue: Annual Report Summaries #12;3 Letter from Public Works Digest is an unofficial publication of the U.S. Army Installa- tion Management Agency, under

US Army Corps of Engineers

70

Bioactive compounds from selected plants used in the XVI century mexican traditional medicine  

Microsoft Academic Search

Mexican ethnobotanical documents from the XVI century have inspired the search of plant bioactive compounds. These treatises were written by Native American and Spaniard naturalists after the Spanish conquest of México in 1521, and contain painstaking descriptions of more than 3,000 plants. The present and ancient native medical applications of selected plants quoted in these ethnohistorical sources are revisited and

E. BÉjar; R. Reyes-Chilpa; M. JimÉnez-Estrada

2000-01-01

71

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

NASA Astrophysics Data System (ADS)

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.

Weisberg, Joel M.; Paglen, Trevor

2012-10-01

72

Premelting at fusion of titanite CaTiSiO5: a calorimetric study  

NASA Astrophysics Data System (ADS)

An extensive anomalously rapid increase of relative enthalpy H( T) - H(298 K) of crystalline CaTiSiO5 was observed by means of high-temperature drop calorimetry when melting point is approached. X-ray diffraction analysis of the quenched products after drop in calorimeter shows that this effect is related to premelting. The determined excess enthalpy of crystals near the melting point reaches up to 115 kJ mol-1, that is about 82 % of the total enthalpy of melting, indicating that the premelting effect reflects configurational changes in the bulk of the crystals rather than a surface melting or any other type of partial melting. The obtained results support the presumption that calorimetrically measured premelting effect in titanite reflects the energy-consuming temperature-induced disordering of the framework elements, Si and Ti, which are strongly bonded to oxygen.

Nerád, I.; Mikšíková, E.; Kosa, L.; Adamkovi?ová, K.

2013-07-01

73

Calorimetric study on the effect of 60Co ?-rays on the growth of microorganisms  

NASA Astrophysics Data System (ADS)

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.

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

2002-03-01

74

REPORT ON CALORIMETRIC STUDIES AT THE NHE LABORATORY IN SAPPORO, JAPAN  

Microsoft Academic Search

Experiments using China Lake type calorimetric cells produced excess power in three out of three experiments and no excess power in three control studies. A detailed analysis is presented for two experiments using the China Lake cells. Anomalous thermistor signals in Cell A suggest the emission of electromagnetic radiation from the active palladium cathode. Experiments in Fleischmann-Pons type calorimetric cells

MELVIN H. MILES

75

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

...would receive. For title II benefits, it includes your monthly benefit and your past-due benefits after any reductions or deductions...this chapter. For title XVI benefits, it includes your monthly benefit and your past-due...

2010-04-01

76

20 CFR 416.572 - Are title II and title VIII benefits subject to adjustment to recover title XVI overpayments?  

Code of Federal Regulations, 2010 CFR

...416.572 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL...title XVI overpayments from benefits payable to you under title II or title VIII of the Social Security Act. (2) Benefits payable. For...

2010-04-01

77

Calorimetric and densimetric examinations of aqueous solutions of heptylene1,7- bis (dimethyloctylammonium bromide) and octylene-1,8- bis (dimethyloctylammonium bromide)  

Microsoft Academic Search

The critical micelle concentrations of gemini surfactants having different spacer chain lengths 8-7-8 and 8-8-8 in aqueous\\u000a solutions have been determined by calorimetric and densimetric methods within a wide temperature range. The isothermal volume\\u000a change upon micellisation of the title surfactants has been obtained from density measurements using pseudo-phase model. Predicted\\u000a values for apparent molar volume of the surfactant at

Henryk PiekarskiKatarzyna; Katarzyna ?udzik; Micha? Wasiak

2011-01-01

78

Fast electron thermometry towards ultra-sensitive calorimetric detection  

E-print Network

We demonstrate radiofrequency 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 {\\mu}K/Hz^1/2 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 {\\mu}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.

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

2014-05-29

79

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

PubMed Central

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

Olalde, Inigo; Sanchez-Quinto, Federico; Datta, Debayan; Marigorta, Urko M.; Chiang, Charleston W. K.; Rodriguez, Juan Antonio; Fernandez-Callejo, Marcos; Gonzalez, Irene; Montfort, Magda; Matas-Lalueza, Laura; Civit, Sergi; Luiselli, Donata; Charlier, Philippe; Pettener, Davide; Ramirez, Oscar; Navarro, Arcadi; Himmelbauer, Heinz; Marques-Bonet, Tomas; Lalueza-Fox, Carles

2014-01-01

80

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

E-print Network

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...

Weisberg, J M

2012-01-01

81

VizieR Online Data Catalog: Fe XVI radiative rates (Diaz+, 2013)  

NASA Astrophysics Data System (ADS)

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 1s22sk2pm3lpnl'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. (2 data files).

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

2013-08-01

82

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

PubMed

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

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

2012-08-23

83

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

84

The Calorimetric Glass Transition of Polystyrene Ultrathin Films  

NASA Astrophysics Data System (ADS)

The glass transition temperature (Tg) for nanoconfined materials have been widely studied since the early 1990s. For supported polystyrene ultrathin films, Tg differs from bulk value. Recent work has attributed nanoconstrained Tg effects to artifact. In this study, we attempted to resolve this controversy and measure Tg for single polystyrene ultrathin films using Flash DSC. Films have been prepared in two ways: spincast films placed on a layer of inert oil or grease and films directly spincast on the back of the calorimetric chip. For the films on oil or on grease, the 160 nm thick films show no Tg depression. On the other hand, thinner films on oil and on grease show a Tg depression which decreases with increasing cooling rate. The depression reverts to the bulk values over the course of a day at 160 ^oC due to dewetting and thickening. For directly spincast films, no Tg depression is observed, consistent with results from other nanocalorimetry work. Our results are consistent with literature results that Tg decreases with decreasing substrate surface energy, and they also demonstrate that the Tg depression observed is not due to degradation or to plasticization effects.

Gao, Siyang; Koh, Yung P.; Simon, Sindee S.

2013-03-01

85

Neutron induced capture and fission discrimination using calorimetric shape decomposition  

NASA Astrophysics Data System (ADS)

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

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

86

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

NASA Astrophysics Data System (ADS)

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.

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

87

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

PubMed

The synthetic imogolite sample was used for organofunctionalization process with 2-mercaptothiazoline (MTZ). The compound 2-mercaptothiazoline was anchored onto imogolite surface by heterogeneous route. Due to the increment of basic centers attached to the pendant chains the dye adsorption capability of the final chelating material, was found to be higher than is precursor. The ability of these materials to remove methylene blue from aqueous solution was followed by a series of adsorption isotherms at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 40.32×10(-2) and 65.13×10(-2) mmol g(-1) for IMO and IMO(MTZ), respectively. The energetic effects caused by dye cations adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such methylene blue-nitrogen and sulfur interactions. PMID:20674169

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

2010-11-15

88

Higher order inclusion complexes and secondary interactions studied by global analysis of calorimetric titrations.  

PubMed

This paper investigates the use of isothermal titration calorimetry (ITC) as a tool for studying molecular systems in which weaker secondary interactions are present in addition to a dominant primary interaction. Such systems are challenging since the signal pertaining to the stronger primary interaction tends to overshadow the signal from the secondary interaction. The methodology presented here enables a complete and precise thermodynamic characterization of both the primary and the weaker secondary interaction, exemplified by the binding of ?-cyclodextrin to the primary and secondary binding sites of the bile salt glycodeoxycholate. Global regression analysis of calorimetric experiments at various concentrations and temperatures provide a precise determination of ?H, ?G°, and ?C(p) for both binding sites in glycodeoxycholate (K1 = 5.67 ± 0.05 × 10(3) M(-1), K2 = 0.31 ± 0.02 × 10(3) M(-1)). The results are validated by a (13)C NMR titration and negative controls with a bile salt with no secondary binding site (glycocholate) (K = 2.96 ± 0.01 × 10(3) M(-1)). The method proved useful for detailed analysis of ITC data and may strengthen its use as a tool for studying molecular systems by advanced binding models. PMID:22292412

Schönbeck, Christian; Holm, René; Westh, Peter

2012-03-01

89

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

PubMed Central

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

Subramanian, S; Kaufman, B T

1978-01-01

90

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

PubMed

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

Botelho, João Bosco

2004-01-01

91

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

NASA Astrophysics Data System (ADS)

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.

Uchida, Takeyoshi; Kikuchi, Tsuneo

2013-07-01

92

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

E-print Network

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 aboard the Hubble Space Telescope, we obtained deep optical imaging of Andromeda II (M$_{V} = -$12.0; log(M$_{\\star}$/M$_{\\odot}$) $\\sim$ 6.7) and Andromeda XVI (M$_{V} = -$7.5; log(M$_{\\star}$/M$_{\\odot}$) $\\sim$ 4.9) yielding color-magnitude diagrams that extend at least 1 magnitude 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$\\sim$5-0.5) and both were abruptly quenched $\\sim$ 5 Gyr ago (z$\\sim$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 si...

Weisz, Daniel R; 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

2014-01-01

93

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

Federal Register 2010, 2011, 2012, 2013

...13-2p; Titles II and XVI: Evaluating Cases Involving Drug Addiction and Alcoholism...question 8. ``What evidence do we need in cases involving DAA?'', a., italicize the...page 11946, second column, under ``15. How should adjudicators consider...

2013-03-22

94

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

E-print Network

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.

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

2014-08-30

95

Calorimetric detection of the conical THz radiation from femtosecond laser filaments in air  

E-print Network

1 Calorimetric detection of the conical THz radiation from femtosecond laser filaments in air Aur (THz) emission from a femtosecond laser filament in air is measured with a bolometric detector and a set of filters, confirming that the main part of the emission lies between 0.5 and 3 THz

Paris-Sud XI, Université de

96

Measurements of AC losses in HTSC wires exposed to an alternating field using calorimetric methods  

Microsoft Academic Search

Calorimetric methods for AC loss measurement for short superconducting wires have been investigated. The design, operation and results obtained from an experimental calorimeter are described. With these methods the total loss of a short superconducting sample exposed to a 50 Hz alternating field, both perpendicular and axial, have been measured with an accuracy of microwatts per centimeter. The sample is

Tri Hardono; Christopher D. Cook; Jian-Xun Jin

1999-01-01

97

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

E-print Network

The Hydrogen Bonding of Cytosinewith Guanine:Calorimetric and`H-NMR Analysis of the Molecular forming hydrogen bonds. Consequently, hydrogen-bond formation in our system is primarily between the bases-pair formation in o-dichlorobenzeneis -6.65 0.32 kcal/mol. Since o-dichlorobenzenedoes not form hydrogen bonds

Williams, Loren

98

Micro-calorimetric sensor for vapor phase explosive detection with optimized heat profile  

Microsoft Academic Search

A heater design, used in a micro-calorimetric sensor, has been optimized for temperature uniformity in order to increase the sensitivity and reliability of detection of trace amounts of explosives. In this abstract the design, fabrication and characterization is described. The performance of the novel heater design is characterized by measuring the temperature coefficient of resistivity (TCR) values and by mapping

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

2010-01-01

99

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

USGS Publications Warehouse

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.

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

1983-01-01

100

DNA energy landscapes via calorimetric detection of microstate ensembles of metastable macrostates and triplet repeat diseases  

Microsoft Academic Search

Biopolymers exhibit rough energy landscapes, thereby allowing biological processes to access a broad range of kinetic and thermodynamic states. In contrast to proteins, the energy landscapes of nucleic acids have been the subject of relatively few experimental investigations. In this study, we use calorimetric and spectroscopic observables to detect, resolve, and selectively enrich energetically discrete ensembles of microstates within metastable

Jens Völker; Horst H. Klump; Kenneth J. Breslauer

2008-01-01

101

DNA Energy Landscapes via Calorimetric Detection of Microstate Ensembles of Metastable Macrostates and Triplet Repeat Diseases  

Microsoft Academic Search

Biopolymers exhibit rough energy landscapes, thereby allowing biological processes to access a broad range of kinetic and thermodynamic states. In contrast to proteins, the energy landscapes of nucleic acids have been the subject of relatively few experimental investigations. In this study, we use calorimetric and spectroscopic observables to detect, resolve, and selectively enrich energetically discrete ensembles of microstates within metastable

Jens Völker; Horst H. Klump; Kenneth J. Breslauer

2008-01-01

102

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

103

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

104

Calorimetric effects during the ? ? ? transformation in Fe-Ni-Ti metastable alloys  

NASA Astrophysics Data System (ADS)

A calorimetric study of the reverse ? ? ? transformation has been carried out in five metastable Fe-Ni-Ti alloys. The amount of the ? phase in the initial samples is more than 50%. The exothermic processes of the decomposition of the ? and ? phases exceed the endothermic reactions of formation of the reverted austenite upon heating to the midpoint of the temperature interval of the reverse ? ? ? transformation. In the middle part of the interval in which the maximum rate of the transformation is recorded by the magnetometric method, the calorimetric curve does not exhibit thermal effects. This disagreement indicates the complex character of the transformation. At the finishing stage of the ? ? ? transformation, there is clearly detected an endothermic reaction.

Zemtsova, N. D.; Eremina, M. A.; Zavalishin, V. A.

2012-05-01

105

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

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

106

Calorimetric study of phase transitions in a liquid-crystal-based microemulsion  

Microsoft Academic Search

A lyotropic inverse micelle phase composed of water, thermotropic liquid-crystal octylcyanobiphenyl (8CB), and surfactant (DDAB) was studied by using high-resolution calorimetry on several mixtures with 3%, 8%, and 15% micelle concentration. Calorimetric results show strong depression of the isotropic to nematic (I-N) phase-transition temperature. Broad heat-capacity anomalies show the existence of a wide coexistence range of isotropic, nematic, and smectic-A

Zdravko Kutnjak; George Cordoyiannis; George Nounesis; Andrija Lebar; Slobodan Zumer

2005-01-01

107

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

SciTech Connect

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

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

1999-04-05

108

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

E-print Network

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 dis...

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

2014-01-01

109

Energy levels, radiative rates and electron impact excitation rates for transitions in Be-like Cl XIV, K XVI and Ge XXIX  

E-print Network

Results for energy levels, radiative rates and electron impact excitation (effective) collision strengths for transitions in Be-like Cl XIV, K XVI and Ge XXIX are reported. For the calculations of energy levels and radiative rates the General-purpose Relativistic Atomic Structure Package ({\\sc grasp}) is adopted, while for determining the collision strengths and subsequently the excitation rates, the Dirac Atomic R-matrix Code ({\\sc darc}) is used. Oscillator strengths, radiative rates and line strengths are listed for all E1, E2, M1 and M2 transitions among the lowest 98 levels of the $n \\le$ 4 configurations. Furthermore, lifetimes are provided for all levels and comparisons made with available theoretical and experimental results. Resonances in the collision strengths are resolved in a fine energy mesh and averaged over a Maxwellian velocity distribution to obtain the effective collision strengths. Results obtained are listed over a wide temperature range up to 10$^{7.8}$ K, depending on the ion.

Aggarwal, K M

2014-01-01

110

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

SciTech Connect

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

Plantier, F., E-mail: frederic.plantier@univ-pau.fr; Missima, D.; Torré, J.-P. [Univ Pau and Pays Adour, CNRS, TOTAL - UMR 5150 – LFC-R - Laboratoire des Fluides Complexes et leurs Réservoirs, BP 1155 – PAU, F-64013 (France)] [Univ Pau and Pays Adour, CNRS, TOTAL - UMR 5150 – LFC-R - Laboratoire des Fluides Complexes et leurs Réservoirs, BP 1155 – PAU, F-64013 (France); Marlin, L. [Univ Pau and Pays Adour, IPRA FR2952 - Fédération de Recherche- Atelier de Physique Générale, BP 1155 – PAU, F-64013 (France)] [Univ Pau and Pays Adour, IPRA FR2952 - Fédération de Recherche- Atelier de Physique Générale, BP 1155 – PAU, F-64013 (France)

2013-12-15

111

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

NASA Astrophysics Data System (ADS)

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.

Lanba, Asheesh; Hamilton, Reginald F.

2014-06-01

112

Calorimetric investigation of liquid Al–Ga–Gd alloys  

Microsoft Academic Search

Partial for gadolinium and integral enthalpies of mixing were determined for liquid Al–Ga–Gd alloys using a high-temperature isoperibolic calorimeter at 1760±5K. The experiments were performed along five sections with constant concentration ratios of Al and Ga in a range of 0.0?xGd?0.6. The resulted integral enthalpies of mixing were fitted by polynomial concentration dependences. The deviation between experimental and predicted by

Dmitry S. Kanibolotsky; Nataliya V. Golovataya; Olena A. Bieloborodova; Vladyslav V. Lisnyak

2004-01-01

113

Calorimetric investigation of TI5Te3 superconductivity  

NASA Astrophysics Data System (ADS)

The specific heat of several samples in the ? phase of the Tl-Te system were measured between 1.8 and 4.2 °K to determine if the previously reported superconductivity in this phase was a true bulk effect or due to filaments of a second phase. These measurements show a change in the specific heat at Tc of the stoichiometric composition, Tl5Te3, which is 60% of the value predicted from the BCS theory. The only second phase present in some samples, as determined by x-ray diffraction, was TlTe; but even as large an amount present as 10% was found to make a very small contribution to the specific heat. Thus we conclude that Tl5Te3 is a bulk superconductor, characterized by an electronic specific heat of 5.7×10-3 cal/mole deg2 and a Debye ?D of 96 °K. Some possible explanations are proposed to account for the low value of the measured specific heat.

Haemmerle, W. H.; Reed, W. A.; Juodakis, A.; Kannewurf, C. R.

1973-03-01

114

Calorimetric Study of Kinetic Glass Transition in Metallic Glasses  

SciTech Connect

Differential scanning calorimetry (DSC) experiments were carried out for a bulk metallic glass (BMG), Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10.0}Be{sub 22.5}, below and above the glass transition temperature T{sub g}. The T{sub g} values were determined from the DSC curves. A wide range of heating rate, q = dT/dt = 0.1-100 K/min, was adopted for the experiment, and the q dependence of the apparent T{sub g} was investigated. As q was decreased, the value of T{sub g} decreased rapidly, then more slowly, and seemed to approach a constant value at low q. The experimental result of this kinetic glass transition phenomenon was analyzed on the basis of the relaxation process occurring in the transition temperature range.

Hiki, Y. [Faculty of Science, Tokyo Institute of Technology, 39-3-303 Motoyoyogi, Shibuya-ku, Tokyo 151-0062 (Japan); Takahashi, H. [Institute of Applied Beam Science, Graduate School of Science and Engineering, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi 316-8511 (Japan)

2008-02-21

115

Calorimetric study of smectic polymorphism in octyloxyphenyl-nitrobenzoyloxy benzoate + decyloxyphenyl-nitrobenzoyloxy benzoate mixtures  

Microsoft Academic Search

Binary mixtures of octyloxyphenyl-nitrobenzoyloxy benzoate (DB8ONO2) and decycloxyphenyl-nitrobenzoyloxy benzoate (DB10ONO2) exhibit a rich variety of smectic polymorphism. An ac calorimetric study has been carried out on six mixtures with mole percent X of the decyl homolog between 51 and 57, a range that includes the Sm-Ad-Nr-Sm-A1 point at X~=56. The sample with X=57 exhibits a first-order direct Sm-Ad-Sm-A1 transition, while

K. Ema; G. Nounesis; C. W. Garland; R. Shashidhar

1989-01-01

116

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

SciTech Connect

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

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

1987-08-01

117

Cooling history of water-rich tube pumice: a calorimetric determination  

Microsoft Academic Search

8.7Ma tube pumice from the Ramadas caldera is remarkable for its preservation and for the kinematics preserved within it. Ramadas tube pumice offers potential insights into the physical conditions surrounding the eruptions that generate such pyroclasts. For these reasons it has been chosen for neutron tomographic investigation (Hess et al., this meeting). The thermal history accompanying explosive eruptions is one

D. B. Dingwell; D. Richard; J. Marti

2009-01-01

118

Calorimetric determination of inhibition of ice crystal growth by antifreeze protein in hydroxyethyl starch solutions.  

PubMed Central

Differential scanning calorimetry and cryomicroscopy were used to investigate the effects of type I antifreeze protein (AFP) from winter flounder on 58% solutions of hydroxyethyl starch. The glass, devitrification, and melt transitions noted during rewarming were unaffected by 100 micrograms/ml AFP. Isothermal annealing experiments were undertaken to detect the effects of AFP-induced inhibition of ice crystal growth using calorimetry. A premelt endothermic peak was detected during warming after the annealing procedure. Increasing the duration or the temperature of the annealing for the temperature range from -28 and -18 degrees C resulted in a gradual increase in the enthalpy of the premelt endotherm. This transition was unaffected by 100 micrograms/ml AFP. Annealing between -18 and -10 degrees C resulted in a gradual decrease in the premelt peak enthalpy. This process was inhibited by 100 micrograms/ml AFP. Cryomicroscopic examination of the samples revealed that AFP inhibited ice recrystallization during isothermal annealing at -10 degrees C. Annealing at lower temperatures resulted in minimal ice recrystallization and no visible effect of AFP. Thus, the 100 micrograms/ml AFP to have a detectable influence on thermal events in the calorimeter, conditions must be used that result in significant ice growth without AFP and visible inhibition of this process by AFP. Images FIGURE 8 PMID:7690257

Hansen, T N; Carpenter, J F

1993-01-01

119

Theoretical basis for differential scanning calorimetric analysis of multimeric proteins.  

PubMed

A new general equation simulating irreversible DSC transitions of multimeric proteins was developed. The equation put forward here is the result of an improved mathematical re-elaboration of the classical Lumry-Eyring models, where no restrictive a priori assumptions are made on the kinetic constraints of the denaturation process, or on the enthalpy of the final denatured state. In order to test the wide applicability of this new effective theoretical tool, a series of DSC transitions were simulated with the aim of determining the effects of all relevant thermodynamic, kinetic or experimental parameters on the shape of DSC profiles. Moreover, the classical equations used widely in DSC investigations for the calculus in both kinetic parameters and changes of molecularity, were studied in the light of the model developed here, highlighting, in each case, their rather limited applicability. The new approach proposed in this article was applied to study the thermal denaturation of an hexameric protein (Glucosamine-6-phosphate deaminase), putting in evidence the practical applicability of the theoretical equations developed. PMID:17029806

Milardi, D; Rosa, C L; Grasso, D

1996-11-29

120

Presented at the ASHRAE Winter Meeting, Atlanta, GA, February 17-21, 1996, and published in the Proceedings. Calorimetric Measurements of Inward-Flowing Fraction  

E-print Network

LBL-37038 Mo-346 Presented at the ASHRAE Winter Meeting, Atlanta, GA, February 17-21, 1996, and published in the Proceedings. Calorimetric Measurements of Inward-Flowing Fraction for Complex Glazing Contract No. DE-AC03-76SF00098. #12;#12;Calorimetric Measurements of Inward-Flowing Fraction for Complex

121

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

PubMed Central

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

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

2014-01-01

122

Calorimetric method for measuring high ultrasonic power using water as a heating material  

NASA Astrophysics Data System (ADS)

The present study shows the calorimetric method for measuring high ultrasonic power using water as the heating material. In recent years, at the National Metrology Institute of Japan (NMIJ), an ultrasonic power primary standard of from 1 mW to 15 W has been established by the radiation force balance (RFB) method. Conventionally, the RFB method is widely used for ultrasonic power measurement, but this method is not suitable for very high power measurement due to thermal damages to the absorbing targets. High power ultrasonic standards, however, are being required by medical HITU measurements and in the sonochemistry industry. In order to meet these requirements, we have started to develop an ultrasonic power standard between 15 W and 200 W. Our final goal is an ultrasonic power standard of up to 500 W. The calorimetric method is an alternative ultrasonic power measurement method to the RFB method. We have adopted this method and use water as the heating material. Water has excellent features as a standard material, because the physical properties of water are well known. In the present study, we present an experimental system and the results for an ultrasonic power standard of up to 100 W. The measured ultrasonic power agreed well with the NMIJ primary standard up to 25 W.

Kikuchi, T.; Uchida, T.

2011-02-01

123

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

PubMed

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

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

2014-01-01

124

Breit-Pauli R-Matrix Calculations for L-Shell Atomic Processes in fe XVI, fe XVII, and XVIII  

NASA Astrophysics Data System (ADS)

We report extensive relativistic close coupling R-matrix calculations of L-shell atomic processes in Fe XVI, Fe XVII, and Fe XVIII. In particular these include photoionization, recombination, transition probabilities, and electron impact excitation of Ne-like Fe XVII. The collisional calculations employ employ the Breit-Pauli R-matrix method and a 89-level eigenfunction expansion including up to n = 4 levels of Fe XVII. Significant resonance enhancement of the collision strengths of forbidden and intercombination is demonstrated. The present results differ from all previous calculations, heretofore without detailed resonance structures, and should help resolve longstanding discrepancies. In particular, the present line ratios of three benchmark diagnostic lines 3C, 3D, and 3E at 15.014, 15.265, and 15.456 Årespectively, are in excellent agreement with two independent measurements on Electron-Beam-Ion-Traps [Laming et al., Astrophys. J 545, L161 (2000) and Brown et al., Astrophys. J 502, 1015 (1998)]. The strong energy dependence due to resonances in these and other cross sections is demonstrated. The new theoretical results should be of considerable interest in uc(x-ray) plasma diagnostics of laboratory and astrophysical sources. Relativistic R-matrix calculations for photoionization and recombination of Fe XVI and Fe XVII are in progress. Partial support from the NSF and NASA is acknowledged.

Chen, Guo Xin; Nahar, Sultana; Pradhan, Anil; Zhang, Honglin

2002-05-01

125

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

...the monthly title II benefits payable for that month...the case of title XVI benefits, an amount no greater than the lesser of the benefit payable for that month...including such monthly benefit but excluding payments...also made from title II benefits and excluding...

2010-04-01

126

20 CFR 404.535 - How much will we withhold from your title VIII and title XVI benefits to recover a title II...  

Code of Federal Regulations, 2010 CFR

(b)(1) We will collect the overpayment from current monthly benefits due in a month under title VIII and title XVI by withholding the lesser of the amount of the entire overpayment balance or: (i) 10 percent of the monthly title VIII benefits payable for that month...

2010-04-01

127

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

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."…

Journal of Science Education and Technology, 2014

2014-01-01

128

forumA publication of the Academic Senate, California State University, FullertonVolume XVI, Number 2, Spring 2001 An Interview with  

E-print Network

of air pollution. The story that follows has two threads: how and why the air has become so much cleaner. Background Southern Californian's live in the epicenter of air pollution. We have the dubious distinctionforumA publication of the Academic Senate, California State University, FullertonVolume XVI, Number

de Lijser, Peter

129

Single-walled carbon nanotubes in superacid: X-ray and calorimetric evidence for partly ordered H2SO4  

E-print Network

Single-walled carbon nanotubes in superacid: X-ray and calorimetric evidence for partly ordered H2. Smalley Center for Nanoscale Science and Technology, Rice University, Houston, Texas 77005, USA Received 7 in the presence of single-walled carbon nanotubes SWNTs . X-ray scattering from aligned fibers immersed in acid

Natelson, Douglas

130

Gravimetric, dielectric and calorimetric methods for the detection of organic solvent vapours using poly(ether urethane) coatings  

Microsoft Academic Search

Cycloaliphatic poly(ether urethane) has been used as a sensitive layer for the detection of organic solvent vapours such as ketones, alcohols, amines, alkanes, aromatic compounds and chlorinated hydrocarbons with quartz microbalances (QMB), interdigital capacitors (IDC) and calorimetric transducers. The sensor signals are completely reversible and reproducible at room temperature. Using QMBs, even less than 10 ppm of nitrobenzene in air

R. Zhou; A. Hierlemann; U. Weimar; W. Göpel

1996-01-01

131

Transport and calorimetric studies on CeNi2Al3  

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

132

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

PubMed

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

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

2014-08-25

133

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

PubMed

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(Zr0.52Ti0.48)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

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

2014-12-21

134

Nano-Calorimetric Studies of Polymeric Phase Transitions in Confined Geometries  

NASA Astrophysics Data System (ADS)

Despite the immense technological significance of phase transitions and thermodynamic properties of polymer thin films and other nano-structures, several fundamental issues remain unresolved. This is partly due to insufficient sensitivity and high thermal time constants of conventional thermal characterization techniques, e.g. differential scanning calorimetry (DSC). On the other hand, the sensitivity of nano-calorimetric devices (.1microW-1nW) has been demonstrated to be two-three orders of magnitude better than conventional DSC systems. Moreover, internal time constants on the order of 1 ms are readily achievable. In this work, MEMS fabrication technology is used to develop ultra-sensitive thin film differential scanning nano-calorimeters. Design optimization of the nano-calorimeter is achieved by numerical finite element simulation of heat transfer across its various constituents. Glass transition and melting behavior of polystyrene and polyethylene oxide thin films are studied using the nano-calorimeter.

Alizadeh, Azar; Zribi, Anis; Ganti, Surya; Sharma, Pradeep; Conway, Ken; Tsakalakos, Loucas; Malenfant, Patrick R. L.; Teetsov, Julie

2003-03-01

135

Total hemispherical emittance measured at high temperatures by the calorimetric method  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

136

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

NASA Technical Reports Server (NTRS)

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

Jaworske, Donald A.

1994-01-01

137

Simulation work on calorimetric energy resolution for the TAC-PF Detector  

NASA Astrophysics Data System (ADS)

According to the Turkish Accelerator Center (TAC) project, a tau-charm factory is proposed based on colliding a 1 GeV electron beam against a 3.5 GeV positron beam. The Particle Factory (TAC-PF) detector will be constructed for the detection of the producing particles from this collision. PbWO4 and CsI(Tl) crystals are considered for the construction of the electromagnetic calorimeter. The photons generated from incident particles in the crystal material are detected by Avalanche photodiodes (APD) or PIN photodiodes placed at the end of the crystal. In this work, the contribution to the calorimetric energy resolution from both the shower fluctuations in the crystal and photoelectron statistics in the detectors have been simulated for PbWO4-APD and PbWO4-PIN combinations.

Tapan, Ilhan; Kocak, Fatma

2012-12-01

138

Reversibility and isotope effect of the calorimetric glass --> liquid transition of low-density amorphous ice.  

PubMed

We here report differential scanning calorimetry (DSC) scans recorded by repeatedly heating the H(2)O (D(2)O) low density amorph (LDA) which was made by isothermal decompression of very high-density amorphous ice (VHDA) at 140 K from 1.1 to 0.006 GPa. These DSC scans show a glass --> liquid transition endotherm with an onset temperature (T(g)) of approximately 137 (140) K at a heating rate of 30 K min(-1) accompanied by an increase in heat capacity of approximately 1.7 (1.5) J K(-1) mol(-1). We establish the reversibility of this effect by thermally cycling between its glassy state below 137 K and its highly viscous liquid state at 149 K. All calorimetric signatures, including H/D isotope effect, are highly similar to the signatures in hyperquenched glassy water (HGW). We argue that the observation of almost identical calorimetric traces for HGW and LDA implies that there is no need to reassign HGWs T(g) to higher temperatures provided that the viscous liquid state connected to both LDA and HGW behaves as an ideally "strong" liquid in the Angell classification. We furthermore show that LDA prepared by isothermal decompression of VHDA is more crystallization-resistant than LDA made from high-density amorphous ice (HDA) by isobaric warming. We suggest that the former route via VHDA removes "nanocrystalline remnants" in LDA which are still present in the latter after pressure-amorphization of hexagonal ice to HDA at 77 K. PMID:20066356

Elsaesser, Michael S; Winkel, Katrin; Mayer, Erwin; Loerting, Thomas

2010-01-21

139

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

E-print Network

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 ...

Harahap, Filino

140

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

NASA Technical Reports Server (NTRS)

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

Perez, Raul M.; Conroy, Bruce L.

1991-01-01

141

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

SciTech Connect

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.

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

2007-09-10

142

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

PubMed Central

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

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

2013-01-01

143

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

PubMed Central

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.

Lopez, Gloria

2014-01-01

144

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

NASA Astrophysics Data System (ADS)

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

Torii, Shoji

145

Differential scanning calorimetric studies of nickel-titanium rotary endodontic instruments after simulated clinical use.  

PubMed

Differential scanning calorimetric (DSC) analyses have been performed between -130 degrees and 100 degrees C on single-segment specimens obtained from ProFile and Lightspeed nickel-titanium rotary endodontic instruments in the as-received condition and after one, three, and six periods of simulated clinical use in extracted teeth. The DSC analyses showed that both brands of instruments were always in the superelastic condition, although the enthalpy values for the transformation from martensitic NiTi to austenitic NiTi were much smaller for the Lightspeed instruments. Simulated clinical use had no evident effect upon this transformation for both brands, which is attributed to insufficient mechanical deformation of the instruments. There were substantial differences in the enthalpy change associated with the transformation from martensitic NiTi to austenitic NiTi for test segments from different positions along the shafts of the instruments and for as-received instruments from two different batches that were analyzed in this study and a previous study. These differences are attributed to variations in work hardening along the shaft during instrument fabrication and to processing differences during production of the two batches of each instrument brand. PMID:12470023

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

2002-11-01

146

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

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

147

Idebenone loaded solid lipid nanoparticles interact with biomembrane models: calorimetric evidence.  

PubMed

The knowledge of the interactions between solid lipid nanoparticles (SLN) and cell membranes is important to develop effective carrier systems for drug delivery applications. Loading idebenone (IDE), an antioxidant drug useful in the treatment of neurodegenerative diseases, into SLN improves IDE antioxidant activity in in vitro biological studies, but the mechanism by which IDE permeation through the blood-brain barrier (BBB) occurs are still unclear. Therefore, in this research, unloaded and IDE loaded SLN interaction with biomembrane models, consisting of dimyristoylphosphatidylcholine multilamellar vesicles (MLV), were studied by differential scanning calorimetry (DSC). In the experiments performed, unloaded and IDE loaded SLN where incubated with the biomembrane models and their interactions were evaluated through the variations in their calorimetric curves. The results of our DSC studies indicated that the SLN under investigation were able to go inside the phospholipid bilayers with a likely localization in the outer bilayers of the MLV from where they moved toward the inner layers by increasing the contact time between SLN and MLV. Furthermore, IDE loaded SLN were able to release IDE into the biomembrane model, thus facilitating IDE penetration into the bilayers while free IDE showed only a low ability to interact with this model of biomembranes. Our results suggest that these SLN could be regarded as a promising drug delivery system to improve IDE bioavailability and antioxidant activity. PMID:22894135

Montenegro, Lucia; Ottimo, Sara; Puglisi, Giovanni; Castelli, Francesco; Sarpietro, Maria Grazia

2012-09-01

148

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

SciTech Connect

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.

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

149

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

SciTech Connect

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

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

1980-01-01

150

Determination of apparent activation energy of concrete by isothermal calorimetry  

Microsoft Academic Search

In recent works at our laboratory, instrumentations have been developed to carry out calorimetric tests on concrete in isothermal conditions, which give much information. The objective of this article is, on the basis of this technique, to study the validity of the Arrhenius law and to determine the evolution of apparent activation energy of the concrete. This parameter is necessary

H. Kada-Benameur; E. Wirquin; B. Duthoit

2000-01-01

151

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

PubMed Central

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

Gentili, Rodolfo; Gentili, Elio; Sgorbati, Sergio

2009-01-01

152

Winter temperatures in the second half of the XVI century in the central area of the Iberian Peninsula  

NASA Astrophysics Data System (ADS)

This paper studies the winter temperatures of the second part of the XVI century in the central area of the Iberian Peninsula. A large number of historical documents that are stored in many different Spanish archives were consulted in order to carry out this research. The data was first arranged and weighted according to the intensity and significance of the meteorological phenomena described and, subsequently, these values were assigned an ordinal index ranging from +4 to -4. The statistical treatment applied is based on the reconstruction of temperatures equivalent to this ordinal index, expressed as anomalies of the 1961-1990 period, belonging to a reference station located at the approximate geographical center of the area under study. The results show winter thermal conditions different from current ones that, for the most part, stay below the reference average and that occurred with a wide range of variability. The influence that thermal conditions had on the evolution of some environmental aspects are considered based on the forest exploitation problem information and on the wine harvest production.

Bullón, T.

2008-06-01

153

Determination by the enzyme thermistor of cellobiose formed on degradation of cellulose  

SciTech Connect

A calorimetric assay procedure for the determination of cellobiose was developed. The cellobiose is hydrolyzed by beta-glucosidase and the glucose formed is measured calorimetrically by an enzyme thermistor containing coimmobilized glucose oxidase and catalase. The system was optimized with regard to the arrangement of the enzymes, the pH-dependence of the separated enzymic steps, and of the total system. By placing the Beta-glucosidase in a precolumn that could be switched in and out of the flow through the enzyme thermistor, both cellobiose and glucose present in the sample could be determined. The performance with saturated solutions and crude samples from cellulose degradation experiments was investigated.

Danielsson, B.; Rieke, E.; Mattiasson, B.; Winquist, F.; Mosbach, K.

1981-01-01

154

Head-group contributions to bilayer stability: monolayer and calorimetric studies on synthetic, stereochemically uniform glucolipids.  

PubMed

Monolayer and differential scanning calorimetry studies have been performed on synthetic, stereochemically uniform glyceroglucolipids having saturated, ether-linked alkyl chains. The limiting area, A0 = 40 A2 X molecule-1, resulting from the monolayer measurements of the glucolipids is comparable to the A0 value found for phosphatidylethanolamine lipids. The area corresponds to twice the value observed with saturated straight chain fatty acids, which indicates that at high surface pressure the space requirement of the glucose head group does not exceed that of the two alkyl chains. The apparent specific heat capacities of the glucolipid dispersions have been found to be higher than those of corresponding phospholipids. They can be approximated from group parameters with the additional assumption that the experimental partial molar heat capacity of glucose is valid for the glucose head groups of the lipids. The transition enthalpies of the C16 and C18 glyceroglucolipids are clearly larger than the delta H values of corresponding phospholipids, while the C14 glyceroglucolipid has the same transition enthalpy as dimyristoylphosphatidylethanolamine or ditetradecylphosphatidylethanolamine. Glucolipids exhibit gel to liquid-crystalline phase transition temperatures which are only slightly lower than those of their phosphatidylethanolamine analogues, although they are uncharged molecules. Like phosphatidylethanolamine the glucolipids do not show a pretransition; however, with the C14 glucolipid a highly cooperative posttransition, approximately 5 deg above the main transition, has been found. Calorimetric experiments with a C14 glucolipid, in which the hydroxyl protons of the glucose moiety have been exchanged by deuterium, suggest that the posttransition might reflect structural changes of the head group.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3994987

Hinz, H J; Six, L; Ruess, K P; Liefländer, M

1985-01-29

155

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

NASA Astrophysics Data System (ADS)

Enthalpies of K-Na mixing for the analbite - sanidine feldspar series were investigated by Hovis (1988, J. Petrology) in the early 80's. That work was based on data at a limited number of compositions, owing to the large sample sizes required for HF solution calorimetric measurements at the time. Thermodynamic mixing properties for mineral series, especially those exhibiting compositionally asymmetric mixing quantities, are best defined when samples at a large number of compositions are utilized. Enabled by the small sample sizes now possible for HF solution calorimetric dissolutions (Hovis et al., 1998, Amer. Mineral.), we revisit feldspar thermodynamic properties, having synthesized an analbite - sanidine series consisting of samples at 20 compositions. Solution calorimetric experiments on these samples at 50 °C in 20.1 wt% HF under isoperibolic conditions have resulted in highly precise calorimetric data (standard deviation per sample averaging 0.06 % of the heat of solution). Although enthalpies of K-Na mixing based on the new data display some degree of compositional asymmetry, with a maximum value of 4.8 kJ/mol at a mole fraction potassium of 0.47, the distribution of enthalpy-of-mixing values remains nearly symmetric with respect to K content. This contrasts significantly with data for Al-Si ordered low albite - microcline crystalline solutions, reinvestigated via synthesis of a 21-member series, which show significantly higher mixing magnitudes and considerably greater asymmetry with respect to composition. The maximization of enthalpies of K-Na mixing at sodic compositions correlates well with the sodic critical compositions for both solvi. The lower mixing magnitudes for analbite - sanidine are consistent with the comparatively lower critical temperature of the analbite - sanidine solvus (e.g., Smith & Parsons, 1974, Mineral. Mag.) relative to that for low albite - microcline (Bachinski & Müller, 1971, J. Petrology). Entropies of K-Na mixing for analbite - sanidine have been calculated by combining present enthalpy data with Gibbs free energies of mixing derived from the earlier phase equilibrium study of Hovis et al. (1991, Amer. Mineral.). These may be compared with directly measured entropy data for analbite - sanidine based on the heat capacity measurements of Haselton et al. (1983, Amer. Mineral.). Thanks to the National Science Foundation for funding this research.

Hovis, G. L.

2013-12-01

156

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

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

157

Confirmation of a calorimetric peculiarity in the crossover region of glass transition in poly( n-hexyl methacrylate) by differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

The Narayanaswamy model for vitrification is modified to deliver local information about the underlying equilibrium trace of calorimetric response in an Arrhenius plot. The analysis of a simple differential scanning calorimetry (DSC) thermogram for polystyrene reproduces the calorimetric equilibrium trace from heat capacity spectroscopy with an accuracy of few tenths of a frequency decade. Further, contour maps for linear dielecric, heat capacity, and shear response in the crossover region of dynamic glass transition in poly( n-hexyl methacrylate) are presented. The calorimetric map has a saddle between the death of the high-temperature process ( a) and the onset of the low-temperature process ( ?). The sigmoid bend in the equilibrium trace near this peculiarity can independently be confirmed by the modified Narayanaswamy model evaluation of a simple DSC thermogram. A speculative, free-volume physical picture of the crossover region is described.

Kahle, S.; Hempel, E.; Beiner, M.; Unger, R.; Schröter, K.; Donth, E.

1999-04-01

158

Determinants  

NSDL National Science Digital Library

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.

Blake, Lewis; Fitchett, Stephanie

2010-05-19

159

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

NASA Astrophysics Data System (ADS)

Laboratory measurements of the n = 3 to n = 3 emission from M-shell iron ions are presented and compared to synthetic spectra from the CHIANTI spectral model. The measurements cover the range 170-290 Å and are made at an electron density of about 1011 cm-3. Emission from Fe VIII through Fe XVI has been identified. Excellent agreement with CHIANTI predictions is found for most lines. Twenty weaker features are noted in the laboratory data that are either absent in CHIANTI or have recently been added and correspond to lines that have not been verified by experimental measurements. A few of these lines may have already been observed (but not yet identified) in the Sun. The features are attributed to emission from various charge states of iron, notably Fe IX and Fe XIII, and two features have been identified as transitions in Fe VIII, i.e., the 3p 63d 2 D 5/2-3p 53d 2 2 P 3/2 and the 3p 63d 2 D 3/2-3p 53d 2 2 P 1/2 transitions at 225.25 ± 0.12 and 226.35 ± 0.10 Å, respectively. Seven lines in Fe XI, Fe XII, and Fe XIII between 200 and 205 Å are noted for which the wavelengths in the CHIANTI database disagree with those in the current database of the National Institute of Standards and Technology. Our measurements of five of these lines appear to agree with the assignments used in CHIANTI.

Beiersdorfer, P.; Lepson, J. K.

2012-08-01

160

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

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.

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

1986-01-01

161

Energetics of the alpha-lactalbumin states: a calorimetric and statistical thermodynamic study.  

PubMed

The temperature dependence of the heat capacity function of holo and apo alpha-lactalbumin has been studied by high sensitivity differential scanning microcalorimetry. The heat capacities of the holo and apo forms in the native state were found to be close to, but somewhat higher than, that of lysozyme, which has a similar structure. At pH values higher than 5, the heat-denatured state and the unfolded state are indistinguishable. At lower pH values, the heat capacity of the state obtained by heat or acid denaturation is lower than what is expected for the completely unfolded polypeptide chain, but it approaches that value at higher temperatures. The heat capacity increment of the denatured state correlates well with the amount of residual structure measured by ellipticity (i.e., the lower the residual structure, the higher the heat capacity). The extent of residual structure in the denatured state, which is exceptionally high in alpha-lactalbumin, decreases upon increasing temperature and at approximately 110 degrees C becomes close to that observed in 6 M GdmCl. Above 110 degrees C, the denatured state of alpha-lactalbumin is practically indistinguishable in heat capacity and ellipticity from the fully unfolded state. The calorimetric data have been analyzed quantitatively using a statistically thermodynamic formalism. This analysis indicates that the long-range or global cooperativity of the protein is lost after heat denaturation of the native state, causing the remaining elements of residual structure to behave in a more or less independent fashion. At pH values close to neutral, heat denaturation occurs at high temperature and yields a totally unfolded polypeptide with no measurable population of partly folded intermediates. At lower pH values, denaturation occurs at lower temperatures and a progressively higher population of intermediates is observed. At pH 4.2, about 50% of the molecules is in compact intermediate states immediately after heat denaturation; however, at pH 3.5, this percentage is close to 80% and at pH 3.0 it reaches about 100% of the protein molecules. Upon heating, the unfolded state progressively becomes the predominant species. The analysis of the heat capacity data for alpha-lactalbumin indicates that the best model to account for the observed behavior is one in which the denatured state is represented as a distribution of substates with varying degrees of residual structure. At low temperatures, the distribution is centered around rather compact substates with significant residual structure. At higher temperatures, the distribution shifts toward states with less residual structure and eventually to the completely unfolded state. PMID:8110793

Griko, Y V; Freire, E; Privalov, P L

1994-02-22

162

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

163

Dynamic Fuzzy c-Means (dFCM) Clustering and its Application to Calorimetric Data Reconstruction in High Energy Physics  

E-print Network

In high energy physics experiments, calorimetric data reconstruction requires a suitable clustering technique in order to obtain accurate information about the shower characteristics such as position of the shower and energy deposition. Fuzzy clustering techniques have high potential in this regard, as they assign data points to more than one cluster,thereby acting as a tool to distinguish between overlapping clusters. Fuzzy c-means (FCM) is one such clustering technique that can be applied to calorimetric data reconstruction. However, it has a drawback: it cannot easily identify and distinguish clusters that are not uniformly spread. A version of the FCM algorithm called dynamic fuzzy c-means (dFCM) allows clusters to be generated and eliminated as required, with the ability to resolve non-uniformly distributed clusters. Both the FCM and dFCM algorithms have been studied and successfully applied to simulated data of a sampling tungsten-silicon calorimeter. It is seen that the FCM technique works reasonably well, and at the same time, the use of the dFCM technique improves the performance.

Radha Pyari Sandhir; Sanjib Muhuri; Tapan Nayak

2012-04-16

164

Spectra of Se XVI to Se XXIV observed in a tokamak plasma  

SciTech Connect

Selenium was injected into the plasma of the Texas Experimental Tokamak by laser ablation. Spectra of Se ions stripped to the n atm = 3 shell were observed photographically with a 2.2-m vacuum spectrograph. Classifications of 60 lines arising from K-like to Na-like ions were determined. A wavelength accuracy of atmapprox. =0.010 xiA was obtained by calibration with internally generated Fe spectra.

Sugar, J.; Kaufman, V.; Rowan, W.L.

1988-02-01

165

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

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

166

The phenomenon of conglomerate crystallization. XVIII. Clavic dissymmetry in coordination compounds. XVI  

Microsoft Academic Search

The x-ray crystal structure of {[Co(NH3)4(CO3)]NO3}2 · H2O has been determined as part of a study of the intra- and interionic interactions present in crystals of several transition-metal-amine complexes chosen to examine the occurrence and causes of conglomerate crystallization. {[Co(NH3)4(CO3)]NO3}2 · H2O crystallizes in the monoclinic space group P21\\/n with cell constantsa=7.4960(9)Å,b=22.673(6),c=10.513(1), andß=91.41(1)°;V=1786.12 Å3, andd(calc;Z=4)=1.915 g cm-3. In all, 5333

Ivan Bernal; James Cetrullo

1990-01-01

167

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

E-print Network

is engaging. Anderson comes well prepared to conduct his exploration Of Plymouth Plantation, and on the whole he succeeds wonderfully in imparting new in- sights concerning its surprising intertextual resonance. Daniel Patterson, ed. Edward Taylor?s Gods... 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...

William J. Scheick

2003-01-01

168

Heat capacity, enthalpy, entropy, and gibbs energy of terbium diboride as determined from calorimetric measurements within 5–300 K  

Microsoft Academic Search

The heat capacity at constant pressure C\\u000a \\u000a p\\u000a (T) of terbium diboride synthesized from elements via an intermediate hydride phase was studied experimentally within 5–300\\u000a K. A ferromagnetic phase transition manifests itself in the C\\u000a \\u000a p\\u000a (T) dependence as a sharp maximum at 142.4 0.1 K. The C\\u000a \\u000a p\\u000a (T) dependence was used to calculate the tempreature dependences of the

V. V. Novikov; A. V. Matovnikov

2007-01-01

169

Population and habitat on the feudal domain iria at the beginning of the XVIth century Eugen Ghita Populaie i habitat pe domeniul cetii iria la nceputul secolului al XVI lea  

E-print Network

Population and habitat on the feudal domain iria at the beginning of the XVIth century Eugen Ghita domeniul cetii iria la începutul secolului al XVI ­lea Eugen Ghi Abstract: The study ,,Population and habitat on the feudal domain iria at the beginning of the XVIth century Eugen Ghita Populaie i habitat pe

Paris-Sud XI, Université de

170

A differential scanning calorimetry method to determine the isothermal crystallization kinetics of cocoa butter  

Microsoft Academic Search

This research aimed to reduce the variability on the data obtained from differential scanning calorimetric (DSC) analysis of the isothermal crystallization kinetics of cocoa butter.To enable transformation of the DSC crystallization peak to a sigmoid crystallization curve, the DSC peak area has to be integrated. Usually, the start and end points of the crystallization peak are determined visually. The result

Imogen Foubert; Peter A. Vanrolleghem; Koen Dewettinck

2003-01-01

171

An assessment by calorimetric calculations of the potential thermal benefit of warming and humidification of insufflated carbon dioxide.  

PubMed

Heat transfer from a patient to warm and humidify insufflated carbon dioxide (CO2) during laparoscopic surgery may contribute to perioperative hypothermia. The magnitude of this effect was calculated using calorimetric calculations. Warming to 37°C and humidifying to 100%, each 100?L of insufflated CO2 would prevent a heat transfer of 3220 calories, which would result in a decrease of temperature by 0.06°C in a 70 kg patient after total body distribution of heat. We conclude that the thermal benefit of warming and humidifying insufflated CO2 is minor, particularly in comparison with other effective and inexpensive perioperative technologies, some of which are not always used out could easily be used. The decision to use heating and humidification of insufflated CO2 should be based on its other risks, benefits, and costs. PMID:24710263

Roth, Jonathan V; Sea, Stephanie

2014-06-01

172

Effect of Composition Heterogeneity on the Calorimetric Glass Transition in Polymer/Solvent and Solvent/Solvent Mixtures  

NASA Astrophysics Data System (ADS)

The composition dependence of the calorimetric Tg has been reported for several polymer blend systems, but there are relatively few studies of mixtures of small molecule glass formers over the entire composition range. The use of small molecule glasses eliminates the constraint of chain connectivity in describing the Tg for one or both of the components. We report the measurement of Tg for mixtures of small-molecule glass formers, and of polystyrene (PS) solutions with a series of dialkyl phthalates (DAPs) as a function of composition. Mixtures of o-terphenyl with tri-m-tolylphosphate exhibit a nearly linear relationship between Tg and volume fraction, with no appreciable broadening of the DSC trace in the transition region. In contrast, PS/DAP mixtures show strong deviations from Flory-Fox behavior for low concentrations of PS. These results are discussed in terms of current models of composition heterogeneity.

Lodge, Timothy P.; Savin, Daniel A.; Larson, Anne M.

2003-03-01

173

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

SciTech Connect

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

Silva, E.P. da [Technical Univ. of Berlin (Germany). Inst. of Thermodynamics] [Technical Univ. of Berlin (Germany). Inst. of Thermodynamics

1999-04-23

174

A more unified picture for the thermodynamics of nucleic acid duplex melting: A characterization by calorimetric and volumetric techniques  

PubMed Central

We use a combination of calorimetric and volumetric techniques to detect and to characterize the thermodynamic changes that accompany helix-to-coil transitions for five polymeric nucleic acid duplexes. Our calorimetric measurements reveal that melting of the duplexes is accompanied by positive changes in heat capacity (?CP) of similar magnitude, with an average ?CP value of 64.6 ± 21.4 cal deg?1 mol?1. When this heat capacity value is used to compare significantly different transition enthalpies (?Ho) at a common reference temperature, Tref, we find ?HTref for duplex melting to be far less dependent on duplex type, base composition, or base sequence than previously believed on the basis of the conventional assumption of a near-zero value for ?CP. Similarly, our densimetric and acoustic measurements reveal that, at a given temperature, all the AT- and AU-containing duplexes studied here melt with nearly the same volume and compressibility changes. In the aggregate, our results, in conjunction with literature data, suggest a more unified picture for the thermodynamics of nucleic acid duplex melting. Specifically, when compared at a common temperature, the apparent large differences present in the literature for the transition enthalpies of different duplexes become much more compressed, and the melting of all-AT- and all-AU-containing duplexes exhibits similar volume and compressibility changes despite differences in sequence and conformation. Thus, insofar as thermodynamic properties are concerned, when comparing duplexes, the temperature under consideration is as important as, if not more important than, the duplex type, the base composition, or the base sequence. This general behavior has significant implications for our basic understanding of the forces that stabilize nucleic acid duplexes. This behavior also is of practical significance in connection with the use of thermodynamic databases for designing probes and for assessing the affinity and specificity associated with hybridization-based protocols used in a wide range of sequencing, diagnostic, and therapeutic applications. PMID:10393911

Chalikian, Tigran V.; Volker, Jens; Plum, G. Eric; Breslauer, Kenneth J.

1999-01-01

175

Calorimetric evaluation of the effects of SiC concentration on precipitation processes in SiC particulate-reinforced 7091 aluminium  

Microsoft Academic Search

A comprehensive differential scanning calorimetric (DSC) investigation has been conducted on the precipitation and dissolution behaviour of SiC particulate-reinforced 7091 aluminium. DSC is shown to be a particularly attractive experimental technique for developing new thermal and thermomechanical processes for aluminium-based metal matrix composites. These new processes are necessitated due to the deleterious effects that the SiC reinforcement causes on the

J. L. Petty-Galis; R. D. Goolsby

1989-01-01

176

Critical behavior at nematic-smectic-A1 phase transitions. I. High-resolution x-ray-scattering and calorimetric study of the liquid-crystal octyloxyphenylnitrobenzoyloxy benzoate  

Microsoft Academic Search

High-resolution x-ray scattering and ac-calorimetric measurements have been carried out near the nematic-smectic-A1 phase transition of the pure liquid-crystal compound octyloxyphenylnitrobenzoyl- oxy benzoate (DB8ONO2). Several forms of the structure factor S(q) for fitting the x-ray line shape have been tested. The critical temperature dependences of the resulting longitudinal and transverse correlation lengths xi|| and xi? and the smectic susceptibility sigma

G. Nounesis; K. I. Blum; M. J. Young; C. W. Garland; R. J. Birgeneau

1993-01-01

177

Detection of nitrite and nitrosocompounds in chemical systems and biological liquids by the calorimetric method  

Microsoft Academic Search

The capacity of nitrite, S-nitrosothiols (RS-NO), dinitrosyl iron complexes (DNICs) with thiolcontaining ligands, and nitrosoamines\\u000a to inhibit catalase has been used for the selective determination of these compounds in purely chemical systems and biological\\u000a liquids: cow milk and colostrum. The limiting sensitivity of the method is 50 nM. A comparison of the results of the determinations\\u000a of RS-NO, DNIC, and

V. Yu. Titov; Yu. M. Petrenko; A. F. Vanin; I. I. Stepuro

2010-01-01

178

Calorimetric vs. van't Hoff binding enthalpies from isothermal titration calorimetry: Ba2+-crown ether complexation.  

PubMed

The 1:1 complexation reaction between Ba(2+) and 18-crown-6 ether is re-examined using isothermal titration calorimetry (ITC), with the goal of clarifying previously reported discrepancies between reaction enthalpies estimated directly (calorimetric) and indirectly, from the temperature dependence of the reaction equilibrium constant K (van't Hoff). The ITC thermograms are analyzed using three different non-linear fit models based on different assumptions about the data error: constant, proportional to the heat and proportional but correlated. The statistics of the fitting indicate a preference for the proportional error model, in agreement with expectations for the conditions of the experiment, where uncertainties in the delivered titrant volume should dominate. With attention to proper procedures for propagating statistical error in the van't Hoff analysis, the differences between Delta H(cal) and Delta H(vH) are deemed statistically significant. In addition, statistically significant differences are observed for the Delta H(cal) estimates obtained for two different sources of Ba(2+), BaCl(2) and Ba(NO(3))(2). The effects are tentatively attributed to deficiencies in the standard procedure in ITC of subtracting a blank obtained for pure titrant from the thermogram obtained for the sample. PMID:15223140

Mizoue, Laura S; Tellinghuisen, Joel

2004-07-01

179

Structural, calorimetric and magnetic properties study of the Cu0,91Fe0,09O system  

NASA Astrophysics Data System (ADS)

In this work the Cu0.91Fe0.09O nanocrystalline system was prepared via the co-precipitation method. Using Mössbauer Spectrometry, X-Ray Diffraction, Vibrating Sample Magnetometry, Thermogravimetry and Differential Scanning Calorimetry, we study the magnetic behavior, and the structural and calorimetric properties of this system. X-ray diffraction shows only the presence of the CuO structural monoclinic phase, suggesting that Cu atoms are substituted by Fe ones. This hypothesis was confirmed by Mössbauer spectrometry at room temperature, because it shows that the spectrum is formed by two doublets, which correspond to Fe + 2 and Fe + 3 sites. Hysteresis cycles obtained by vibrating sample magnetometry detect a soft ferromagnetic behavior at room temperature with coercive fields between 8 and 20 Oe. At T = 20 K the sample shows a hard-magnetic behavior. The thermogravimetry results show a Néel temperature (T N > 440 °C). The differential scanning calorimetry curve show two endothermic peaks in the 90-120 °C range.

Colorado, H. D.; Hernandez, J. S. Trujillo; Alcázar, G. A. Pérez; Bolaños, Alberto

2013-04-01

180

Structural, calorimetric and magnetic properties study of the Cu0,91Fe0,09O system  

NASA Astrophysics Data System (ADS)

In this work the Cu0.91Fe0.09O nanocrystalline system was prepared via the co-precipitation method. Using Mössbauer Spectrometry, X-Ray Diffraction, Vibrating Sample Magnetometry, Thermogravimetry and Differential Scanning Calorimetry, we study the magnetic behavior, and the structural and calorimetric properties of this system. X-ray diffraction shows only the presence of the CuO structural monoclinic phase, suggesting that Cu atoms are substituted by Fe ones. This hypothesis was confirmed by Mössbauer spectrometry at room temperature, because it shows that the spectrum is formed by two doublets, which correspond to Fe + 2 and Fe + 3 sites. Hysteresis cycles obtained by vibrating sample magnetometry detect a soft ferromagnetic behavior at room temperature with coercive fields between 8 and 20 Oe. At T = 20 K the sample shows a hard-magnetic behavior. The thermogravimetry results show a Néel temperature (T N > 440 °C). The differential scanning calorimetry curve show two endothermic peaks in the 90-120 °C range.

Colorado, H. D.; Hernandez, J. S. Trujillo; Alcázar, G. A. Pérez; Bolaños, Alberto

2014-01-01

181

A calorimetric characterization of Cr(VI)-reducing Arthrobacter oxydans at different phases of the cell growth cycle.  

PubMed

This is the first of a series of calorimetric studies designed to characterize and understand survival mechanisms of metal-reducing bacteria isolated from metal-polluted environments. In this paper we introduce a new concept of thermal spectrum of the endothermic melting of complex biological systems (e.g., proteins, nucleic acids, ribosomes, membrane structures) in intact cells. All thermal spectra measured are thermograms that describe the temperature dependence of heat capacity change of the complex systems of biologically active substances in bacterial cells. This new concept of thermal spectrum was applied to investigate spectral features from intact cells of Cr(VI)-reducer Arthrobacter oxydans at different points of their growth conditions and stages. Over the temperature range of 40-105 degrees C, we observed that spectral changes are particularly significant in the 40-90 degrees C interval. This may correspond to the orderly changes in subcellular structural elements: proteins, ribosomes and RNA, membranes, and various structural elements of the cell wall during different points of the growth cycle and growth conditions. Spectral changes in the 90-105 degrees C region are less pronounced, implicating that the structural composition of DNA-Protein (DNP) complexes may change little. PMID:12806104

Bakradze, Nugzar G; Abuladze, Marina K; Sokhadze, Victor M; Asatiani, Nina V; Sapojnikova, Nelly A; Kartvelishvili, Tamara M; Namchevadze, Emma N; Tsibakhashvili, Nelly Y; Tabatadze, Leila V; Lejava, Lia V; Holman, Hoi-Ying

2003-05-28

182

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

PubMed

Poly(A) has significant relevance to mRNA stability, protein synthesis and cancer biology. The ability of two phenothiazinium dyes azure A (AA) and azure B (AB) to bind single-stranded poly(A) was studied by spectroscopic and calorimetric techniques. Strong binding of the dyes and the higher affinity of AA over AB were ascertained from absorbance and fluorescence experiments. Significant perturbation of the circular dichroism spectrum of poly(A) in the presence of these molecules with formation of induced CD bands in the 300-700 nm region was observed. Strong emission polarization of the bound dyes and strong energy transfer from the adenine base pairs of poly(A) suggested intercalative binding to poly(A). Intercalative binding was confirmed from fluorescence quenching experiments and was predominantly entropy driven as evidenced from isothermal titration calorimetry data. The negative values of heat capacity indicated involvement of hydrophobic forces and enthalpy-entropy compensation suggested noncovalent interactions in the complexation for both the dyes. Poly(A) formed a self-assembled structure on the binding of both the dyes that was more favored under higher salt conditions. New insights in terms of spectroscopic and thermodynamic aspects into the self-structure formation of poly(A) by two new phenothiazinium dyes that may lead to structural and functional damage of mRNA are revealed from these studies. PMID:24953877

Paul, Puja; Kumar, Gopinatha Suresh

2014-08-01

183

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

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…

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

2008-01-01

184

DSC in the Chemical Analysis of Drugs. Determination of diclofenac in pharmaceutical formulations  

Microsoft Academic Search

Differential scanning calorimetry was applied to the determination of diclofenac in three 'Voltaren' formulas. The pharmaceutical\\u000a products (soluble tablets, suppositories and vials) were selected in order to show that calorimetric analysis is an easy technique\\u000a to perform and can be competitive with other conventional methods.\\u000a \\u000a In the tablets diclofenac (DH) was determined, without any pre-treatment, from the area of the

R. Bucci; A. D. Magrì; A. L. Magrì

2000-01-01

185

A quick method of determining calcium in additives and additive-type lubricants  

Microsoft Academic Search

1.A quick method has been developed for determining calcium in additives and additive-type lubricants. The method is based on separating the calcium from the additive by oxidation with oxygen in a calorimetric selfsealing bomb. The calcium that is evolved is determined quantitatively by titration with Trilon B in the presence of a mixture of fluorexone and murexide indicators.2.The method was

N. P. Sosnina

1969-01-01

186

Calorimetric studies of crystallization and relaxation of amorphous Si and Ge prepared by ion implantation  

NASA Astrophysics Data System (ADS)

Amorphous Si and Ge layers, produced by noble gas (Ar or Xe) implantation of single crystal substrates, have been crystallized in a differential scanning calorimeter (DSC). The MeV implantation energies resulted in amorphous layers of micron thickness whose areal densities were determined using the Rutherford backscattering and channeling of 1-MeV protons. These techniques allow determination of the amorphous-crystal interface velocity (which is proportional to the rate of heat evolution ??ac) and the total enthalpy of crystallization ?Hac. Amorphous Ge was found to relax continuously to an amorphous state of lower free energy, with a total enthalpy of relaxation of 6.0 kJ/mol before the onset of rapid crystallization. The interface velocity for crystallization on (100) substrates, was found to have an Arrhenius form with an activation energy of 2.17 eV. The value of ?Hac was found to be 11.6±0.7 kJ/mol, the same as for samples prepared by deposition. For Si, ?Hac was determined to be 11.9±0.7 kJ/mol without any evidence of heat release due to relaxation. The (100) interface velocity was found to have an activation energy of 2.24 eV. The effects of the implant depth profile on the regrowth velocity could also be observed directly in the DSC signal. From the value of ?Hac and Gibbs free-energy calculations, the melting temperature of amorphous Si has been determined to be Tal =1420 K.

Donovan, E. P.; Spaepen, F.; Turnbull, D.; Poate, J. M.; Jacobson, D. C.

1985-03-01

187

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

Microsoft Academic Search

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

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

2000-01-01

188

An open circuit respiration unit for calorimetric studies with small animals.  

PubMed

Two open-circuit respiration chambers for small animals (rats, poultry and rabbits) have been built at the Estación Experimental del Zaidín. The respiration facility is air-conditioned, the temperature and the relative humidity in the chambers can be regulated from about +15 to +30 degrees C and from 60 to 90%, respectively. The air flow is determined by the differential pressure principle, CO2 measurement is by the infra-red technique and O2 analyser is of the paramagnetic type. The present work describes the technical details of the respiration plant and the calibration procedures of the whole system. PMID:2937387

Aguilera, J F; Prieto, C

1985-12-01

189

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

NASA Astrophysics Data System (ADS)

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.

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

1994-07-01

190

Thermochemistry of 2- and 3-thiopheneacetic acids: calorimetric and computational study.  

PubMed

The enthalpies of formation in the condensed and gas states, Delta f H m degrees (cd) and Delta f H m degrees (g), of 2- and 3-thiopheneacetic acids were derived from their respective enthalpies of combustion in oxygen, measured by a rotating bomb calorimeter, and the variation of vapor pressure with temperature determined by the Knudsen effusion technique. Theoretical calculations at the G3 level were performed, and a study on molecular and electronic structure of the compounds has been carried out. Calculated Delta f H m degrees (g) values using atomization and isodesmic reactions are compared with the experimental data. Experimental and theoretical results show that the 3-thiopheneacetic acid is thermodynamically more stable than the 2-isomer. PMID:18816026

Temprado, Manuel; Roux, María Victoria; Jiménez, Pilar; Foces-Foces, Concepción; Notario, Rafael

2008-10-16

191

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

SciTech Connect

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

Maglic, K.D.; Perovic, N.Lj.; Stanimirovic, A.M. [Institute of Nuclear Sciences, Belgrade (Yugoslavia)

1994-07-01

192

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

193

Calorimetric and computational study of 1,3- and 1,4-oxathiane sulfones.  

PubMed

The enthalpies of formation in the condensed and gas states, DeltafH degrees m(cd) and DeltafH degrees m(g), of 1,3- and 1,4-oxathiane sulfones were derived from their respective enthalpies of combustion in oxygen, measured by a rotating bomb calorimeter and the variation of vapor pressures with temperatures determined by the Knudsen effusion technique. Standard ab initio molecular orbital calculations at the G2(MP2) and G3 levels were performed, and a theoretical study on molecular and electronic structure of the compounds has been carried out. Calculated DeltafH degrees m(g) values at the G3 level using atomization reactions agree well with the experimental ones. These experimental and theoretical studies support that the destabilization found in 1,3-oxathiane sulfone, 11.2 kJ mol-1 respecting to 1,4-oxathiane sulfone, is due to the electrostatic repulsion between the negative charges of the axial oxygen of the sulfone and the oxygen of the ring and apparently masks any stabilization originating from the hyperconjugative nO --> sigma*C-SO2 stereoelectronic interaction. PMID:17288369

Roux, María Victoria; Temprado, Manuel; Jiménez, Pilar; Notario, Rafael; Guzman-Mejía, Ramón; Juaristi, Eusebio

2007-02-16

194

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

PubMed Central

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

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

2013-01-01

195

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

SciTech Connect

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.

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

196

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

Federal Register 2010, 2011, 2012, 2013

...understand the basis for the materiality finding...follow prescribed treatment be an issue in DAA...Who is responsible for determining materiality...addiction'' and ``alcoholism'' are medically...currently receiving treatment for a Substance Use...

2013-02-20

197

High-Resolution X-Ray and AC Calorimetric Studies of Smectic Liquid Crystals.  

NASA Astrophysics Data System (ADS)

High-resolution x-ray measurements of the smectic(Sm) layer thickness 'd' of six homologs (TB3A-TB8A) of terephthal -bis-(4n)-butylaniline have been made, with an accuracy 200-400 ppm, as a function of temperature. The nematic to Sm-A transition temperature and Sm-A layer thickness showed even-odd effect as the number of carbons in the alkyl tails of the molecules was changed. In the Sm-C phase, the exponent of the molecular tilt for TB3A and TBBA has a value close to 1/3, implying critical behavior. For higher homologs the smaller value of this exponent and the larger heat of transition show that the Sm-A to Sm -C transition becomes weakly first order. Two new effects, asymmetry of the Bragg reflections in the Sm-C phase due to undulations in the bulk sample, and the existence of domains with different values of d in the Sm-H and other lower temperature phases, were observed. A discontinuous change in d at the Sm-C to Sm-H transition of TBBA was measured for the first time to be 0.08 (ANGSTROM). The jump in d at the Sm-C to Sm-F/H transition and variation of d with temperature in the H phase are strongly dependent on the size of the molecule. In the Sm-H phase the molecular tilt for TB8A decreases with temperature in contrast to other homologs. However, the (110) spacing (measured with error less than 50ppm) of Sm-H increases with temperature for both TB5A and TB8A. The Sm-F phase of TB8A was identified by its miscibility with TB7A. The transition temperatures and heat of transitions were determined by polarizing microscopy and differential scanning calorimetry(DSC). The x-ray and DSC measurements indicated that the Sm-F to Sm-H transition might be nearly second order. High -resolution ac specific-heat measurements on this transition of N-(heptyloxybenzalidene)-4-n-hexylaniline (HBHA) were carried out due to its stability and miscibility with TB5A. A hysteresis of 160 m(DEGREES)K in the transition was measured for the first time for transitions in liquid crystals. The specific-heat, obtained while heating, is larger and changes more rapidly at the transition than during the cooling scan. This behavior is explained by assuming that the transition is first order and dislocations play important role near this transition. The temperature dependence of d in the Sm-F phase of HBHA is qualitatively different from that of TB5A (and its homologs).

Kumar, Satyendra

1981-06-01

198

The determination of the specific heat of a fine-grained soil by a non-mixing method  

E-print Network

. S 5 ~ Variation of Soil Speoifio Heat with Moisture Content . . . ~ . . ~ ~ ~ ~ ~ ~ ~ ~ ~ 21 INTRODUCTION For many years the speoific heat of soils has been determined by the method of mixtures ~ Involved in this method was ths mixing ef ths soil... soil specimen. As a result of the mixing oi' the moist soil specimen and the calorimetric fluidJ no direct measurement of the moisture content of the soil specimen could be made A method of test which greatly simplifies the determination...

Evans, Leighton Allen

2012-06-07

199

Relativistic Fine Structure Transition Probabilities for Li-LIKE Ions: C IV - si XII, S XIV, ar XVI, ca XVIII, ti XX, cr XXII, and ni XXVI  

NASA Astrophysics Data System (ADS)

Ab initio relativistic calculations employing the Breit-Pauli R-matrix (BPRM) method are reported for fine structure energy levels and oscillator strengths upto n = 10 and 0 <= l <= 9 for 15 Li-like ions: C IV, N V, O VI, F VII, Ne VIII, Na IX, Mg X, Al XI, Si XII, S XIV, Ar XVI, Ca XIII, Ti XX, Cr XXII, and Ni XXVI. About one hundred bound fine structure energy levels of total angular momenta, 1/2 <= J <= 17/2 of even and odd parities, total orbital angular momenta, 0 <= L <= 9 and spin multiplicity (2S+1) = 2, 4 are considered for each ion. The levels provide almost 900 dipole allowed and intercombination transitions. The BPRM method enables consideration of many sets of transition arrays with uniform accuracy comparable to other ab inito theoretical methods, but which entail a much smaller number of transitions. The close coupling eigenfunction expansion for each ion includes the lowest 17 fine structure energy levels of the He-like core configurations 1s^2, 1s2s, 1s2p, 1s3s, 1s3p, and 1s3d. The calculated level energies agree with the measured values to within 1% for most levels. The transition probabilities show good agreement with the best available values. The results provide the largest sets of energy levels and transition rates for these ions, and are expected to be useful in the analysis of X-ray and EUV astrophysical sources. Partial support from the NSF and NASA is acknowledged.

Nahar, Sultana

2002-05-01

200

Relativistic fine structure oscillator strengths for Li-like ions: C IV - Si XII, S XIV, Ar XVI, Ca XVIII, Ti XX, Cr XXII, and Ni XXVI  

NASA Astrophysics Data System (ADS)

Ab initio calculations including relativistic effects in the Breit-Pauli R-matrix (BPRM) method are reported for fine structure energy levels and oscillator strengths upto n = 10 and 0 <= l <= 9 for 15 Li-like ions: C IV, N V, O VI, F VII, Ne VIII, Na IX, Mg X, Al XI, Si XII, S XIV, Ar XVI, Ca XIII, Ti XX, Cr XXII, and Ni XXVI. About one hundred bound fine structure energy levels of total angular momenta, 1/2 <= J <= 17/2 of even and odd parities, total orbital angular momentum, 0 <= L <= 9 and spin multiplicity (2S + 1) = 2, 4 are obtained for each ion. The levels provide almost 900 allowed bound-bound transitions. The BPRM method enables consideration of large set of transitions with uniform accuracy compared to the best available theoretical methods. The CC eigenfunction expansion for each ion includes the lowest 17 fine structure energy levels of the core configurations 1s2, 1s2s, 1s2p, 1s3s, 1s3p, and 1s3d. The calculated energies of the ions agree with the measured values to within 1% for most levels. The transition probabilities show good agreement with the best available calculated values. The results provide the largest sets of energy levels and transition rates for the ions and are expected to be useful in the analysis of X-ray and EUV spectra from astrophysical sources. Complete electronic files for energies (e.g. Tables 3a and 3b) and transition probabilities (e.g. Table 7) are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)} or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/389/716

Nahar, S. N.

2002-07-01

201

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)

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.

Bayer Corporation

2014-10-01

202

Micromechanical calorimetric sensor  

DOEpatents

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.

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

2000-01-01

203

Calorimetric and computational study of thiacyclohexane 1-oxide and thiacyclohexane 1,1-dioxide (thiane sulfoxide and thiane sulfone). Enthalpies of formation and the energy of the S=O bond.  

PubMed

A rotating-bomb combustion calorimeter specifically designed for the study of sulfur-containing compounds [J. Chem. Thermodyn. 1999, 31, 635] has been used for the determination of the enthalpy of formation of thiane sulfone, 4, Delta(f)H(o) m(g) = -394.8 +/- 1.5 kJ x mol(-1). This value stands in stark contrast with the enthalpy of formation reported for thiane itself, Delta(f)H(o) m(g) = -63.5 +/- 1.0 kJ x mol(-1), and gives evidence of the increased electronegativity of the sulfur atom in the sulfonyl group, which leads to significantly stronger C-SO2 bonds. Given the known enthalpy of formation of atomic oxygen in the gas phase, Delta(f)H(o) m(O,g) = +249.18 kJ x mol(-1), and the reported bond dissociation energy for the S=O bond in alkyl sulfones, BDE(S=O) = +470.0 kJ x mol(-1), it was possible to estimate the enthalpy of formation of thiane sulfoxide, 5, a hygroscopic compound not easy to use in experimental calorimetric measurements, Delta(f)H(o) m(5) = -174.0 kJ x mol(-1). The experimental enthalpy of formation of both 4 and 5 were closely reproduced by theoretical calculations at the G2(MP2)+ level, Delta(f)H(o) m(4) = -395.0 kJ x mol(-1) and Delta(f)H(o) m(5) = -178.0 kJ x mol(-1). Finally, calculated G2(MP2)+ values for the bond dissociation energy of the S=O bond in cyclic sulfoxide 5 and sulfone 4 are +363.7 and +466.2 kJ x mol(-1), respectively. PMID:12608789

Roux, María Victoria; Temprado, Manuel; Jiménez, Pilar; Dávalos, Juan Zenón; Notario, Rafael; Guzmán-Mejía, Ramón; Juaristi, Eusebio

2003-03-01

204

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

PubMed Central

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

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

2007-01-01

205

Spectral-based calorimetric calibration of a 3CCD color camera for fast and accurate characterization and calibration of LCD displays  

NASA Astrophysics Data System (ADS)

LCD displays exhibit significant amount of variability in their tone-responses, color responses and backlight-modulation responses. LCD display characterization and calibration using a spectrometer or a color meter, however, leads to two basic deficiencies: (a) It can only generate calibration data based on a single spot on the display (usually at panel center); and (b) It generally takes a significant amount of time to do the required measurement. As a result, a fast and efficient system for a full LCD display characterization and calibration is required. Herein, a system based on a 3CCD calorimetrically-calibrated camera is presented which can be used for full characterization and calibration of LCD displays. The camera can provide full tri-stimulus measurements in real time. To achieve high-degree of accuracy, colorimetric calibration of camera is carried out based on spectral method.

Safaee-Rad, Reza; Aleksic, Milivoje

2011-03-01

206

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

PubMed

SuperCDMS is an experiment designed to directly detect weakly interacting massive particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this Letter, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage-assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for ten live days at the Soudan Underground Laboratory. A low energy threshold of 170??eVee (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6??GeV/c2. PMID:24580434

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

2014-01-31

207

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

SciTech Connect

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

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

1999-02-10

208

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)

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.

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

1988-01-01

209

CHAPTER XVI TUNICATES AND LANCELETS  

E-print Network

or hard skeletal parts, they have not left recognizable fossils. Though of very minor economic importance to the numerous zooids and often have much superficial likeness to the sponges in association with which they very

210

Computational Reality XVI Temperature dependency  

E-print Network

dependency of the coefficients From a thermodynamical point of view, as introduced in Comp.Real.X, the changeU = ij dji + T dS , (1) where the Cauchy stress tensor, Euler-Almansi strain tensor, absolute temperature the reference temperature Tref.. For "semi-solid" or "fluid-like" materials, such as polymer melts, cosmetic

Berlin,Technische Universität

211

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

PubMed Central

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

Sartor, G; Mayer, E

1994-01-01

212

Interaction of the 5-fluorouracil analog 5-fluoro-2'-deoxyuridine with 'N' and 'B' isoforms of human serum albumin: a spectroscopic and calorimetric study.  

PubMed

Drugs and metabolites are transported in the blood by plasma proteins, such as human serum albumin (HSA). The uridine analog 2'dFUrd, which is a cytotoxic prodrug metabolite of capecitabine, has remarkable activity against solid tumors when administered orally. We report the results of an in vitro experimental study on the interactions of 2'-dFUrd with the N-isoform (at pH 7.4) and B-isoform (at pH 9.0) of HSA, investigated using fluorescence spectroscopy, circular dichroism (CD), isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC), and molecular docking. The binding constant (Kb) was higher for the N-isoform than for the B-isoform. Thermodynamic parameters, such as enthalpy change (?H°), entropy change (?S°), and Gibbs free energy change (?G°), were also calculated for both isoform interactions using calorimetric techniques. The thermostabilities of HSA and the HSA-2'dFUrd complex were found to be higher for the N-isoform. The interaction of 2'dFUrd with HSA was also explored in molecular docking studies, which revealed that 2'dFUrd was bound to the Sudlow site I in subdomain IIA through multiple modes of interaction, such as hydrophobic interactions and hydrogen bonding. These results suggest that 2'dFUrd has higher binding affinity for the N-isoform of HSA. PMID:25141914

Ishtikhar, Mohd; Khan, Shawez; Badr, Gamal; Osama Mohamed, Amany; Hasan Khan, Rizwan

2014-09-30

213

Calorimetric and computational study of 2H-1, 4-benzoxazin-3(4H)-one and of related species  

NASA Astrophysics Data System (ADS)

The standard molar enthalpy of formation in the gas phase of 2H-1,4-benzoxazin-3(4H)-one was derived from the standard energy of combustion determined by static bomb combustion calorimetry in oxygen atmosphere and from the standard sublimation enthalpy determined by Calvet microcalorimetry. In addition, we report the results of a systematic theoretical study of the keto and enol tautomers in benzoxazinones and diones using density functional theory. The keto tautomers are computed to be more stable than the enols. Tautomerization energies are reported.

Agostinha, M.; Matos, R.; Miranda, Margarida S.; Morais, Victor M. F.; Liebman, Joel F.

214

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

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

215

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

SciTech Connect

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.

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

2009-12-21

216

A calorimetric study of the acid dissociation of the conjugate acids of poly( N -vinylimidazole) and polyallylamine  

Microsoft Academic Search

Thermodynamic parameters for acid dissociation of the conjugate acids of poly(N-vinylimidazole) and polyallylamine have been determined in the presence of sodium chloride and sodium nitrate. Even though\\u000a the plots of ?G\\u000a 0 against the degree of dissociation, ?, are highly dependent on the added salt concentration levels, the concentration effect\\u000a has never been observed for the corresponding ?H\\u000a 0 versus

H. Kodama; T. Miyajima; H. Tabuchi; S. Ishiguro

2000-01-01

217

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

PubMed

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

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

2014-07-01

218

Calorimetric and computational study of 1,4-dithiacyclohexane 1,1-dioxide (1,4-dithiane sulfone).  

PubMed

This work reports the enthalpies of formation in the condensed and gas state of 1,4-dithiacyclohexane 1,1-dioxide (1,4-dithiane sulfone, 5), derived from the enthalpy of combustion in oxygen, measured by a rotating bomb calorimeter and the variation of vapor pressures with temperatures determined by the Knudsen effusion technique. The theoretically estimated enthalpy of formation was calculated from high-level ab initio molecular orbital calculations at the G2(MP2) level. The theoretical calculations appear to be in very good agreement with experiment. A comparison of the conversion of thiane sulfone 3 to 1,3-dithiane sulfone 4 and 1,4-dithiane sulfone 5 clearly shows the 1,3 isomer to be 6.7 kJ mol(-1) less stable, probably owing to diminished electrostatic repulsion between the sulfur heteroatoms in 1,4-sulfone 5. PMID:16555808

Roux, María Victoria; Temprado, Manuel; Jiménez, Pilar; Notario, Rafael; Guzman-Mejía, Ramón; Juaristi, Eusebio

2006-03-31

219

Calorimetric and computational study of 1,3-dithiacyclohexane 1,1-dioxide (1,3-dithiane sulfone).  

PubMed

The enthalpies of combustion and sublimation of 1,3-dithiacyclohexane 1,1-dioxide (1,3-dithiane sulfone) were measured by a rotating-bomb combustion calorimeter and the Knudsen effusion technique, and the gas-phase enthalpy of formation was determined, Delta(f)H(m)*(g) = -326.3 +/- 2.0 kJ mol(-1). Standard ab initio molecular orbital calculations at the G2(MP2) level were performed, and a theoretical study on molecular and electronic structure of the compound has been carried out. Calculated Delta(f)H(m)*(g) values agree very well with the experimental one. These experimental and theoretical studies support the relevance of the repulsive electrostatic interaction between sulfur atoms in 1,3-dithiane sulfone, that apparently counterbalances any n(S) --> rho(C-SO2)* stabilizing hyperconjugative interaction. PMID:14987027

Roux, María Victoria; Temprado, Manuel; Jiménez, Pilar; Notario, Rafael; Guzmán-Mejía, Ramón; Juaristi, Eusebio

2004-03-01

220

Calorimetric study of thermal crystallization kinetics in Se78-xTe20Sn2Pbx (0 ? x ? 6) alloys  

NASA Astrophysics Data System (ADS)

Glassy samples of Se78-xTe20Sn2Pbx (0 ? x ? 6) system are prepared by melt quenching method. For non-isothermal study of crystallization kinetics, DSC scans have been taken at the heating rates 5, 10, 15 and 20 K/min in non-isothermal mode. Activation energy of crystallization (Ec) has been calculated using Kissinger method, Matusita-Sakka method and Augis-Bennett method. Various kinetic parameters of crystallization kinetics like peak crystallization temperature (Tc), Rate constants (K) and order parameter (n) are determined using these DSC scans. Thermodynamic parameters such as crystallization enthalpy (?Hc) and entropy change during the crystallization (?S) are also evaluated. Results are discussed using chemical bond approach.

Kumar, H.; Mehta, N.

2013-05-01

221

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

SciTech Connect

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

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

2008-06-16

222

A practical method to determine the heating and cooling curves of x-ray tube assemblies  

SciTech Connect

A practical method to determine the heating and cooling curves of x-ray tube assemblies with rotating anode x-ray tube is proposed. Available procedures to obtain these curves as described in the literature are performed during operation of the equipment, and the precision of the method depends on the knowledge of the total energy applied in the system. In the present work we describe procedures which use a calorimetric system and do not require the operation of the x-ray equipment. The method was applied successfully to a x-ray tube assembly that was under test in our laboratory.

Bottaro, M.; Moralles, M.; Viana, V.; Donatiello, G. L.; Silva, E. P. [Instituto de Eletrotecnica e Energia da Universidade de Sao Paulo, Av. Prof. Luciano Gualberto, 1289, CEP 05508-010, Sao Paulo, SP (Brazil); Instituto de Pesquisas Energeticas e Nucleares, Av. Prof. Lineu Prestes, 2.242, CEP 05508-000 Sao Paulo, SP (Brazil); Instituto de Eletrotecnica e Energia da Universidade de Sao Paulo, Av. Prof. Luciano Gualberto, 1289, CEP 05508-010, Sao Paulo, SP (Brazil)

2007-10-15

223

Determination of accessible silanols groups on silica gel surfaces using microcalorimetric measurements.  

PubMed

The calorimetric measurements of methanol and hexane heats of immersion were carried out on different silica gels. Based on the difference in immersion heats, a methodology for the determination of the number of silanols on the surface is presented. The calculated concentration of residual silanols on the silica gel surface agreed with data found in the literature. The proposed methodology, based on a calculation of possible hydrogen bond formation, was also tested on the series of bonded stationary phases with different coverage densities. A very good correlation between the calculated number of accessible residual silanols and the coverage density of bonded ligands was observed. PMID:21955782

Buszewski, Bogus?aw; Bocian, Szymon; Rychlicki, Gerhard; Matyska, Maria; Pesek, Joseph

2012-04-01

224

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

NASA Technical Reports Server (NTRS)

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.

Gostowski, Rudy C.

2002-01-01

225

Thermochemistry of 1,3-dithiacyclohexane 1-oxide (1,3-dithiane sulfoxide): calorimetric and computational study.  

PubMed

The enthalpies of combustion and sublimation of 1,3-dithiacyclohexane 1-oxide (1,3-dithiane sulfoxide, 2) were measured by a rotating-bomb combustion calorimeter and the Knudsen effusion technique, and the gas-phase enthalpy of formation was determined, DeltafH degrees m(g) = -98.0 +/- 1.9 kJ mol(-1). This value is not as large (negative) as could have been expected from comparison with thermochemical data available for the thiane/thiane oxide reference system. High-level ab initio molecular orbital calculations at the MP2(FULL)/6-31G(3df,2p) level were performed, and the optimized molecular and electronic structures of 2 afforded valuable information on (1) the relative conformational energies of 2-axial and 2-equatorial--the latter being 7.1 kJ mol(-1) more stable than 2-axial, (2) the possible involvement of nS --> sigma*(C-S(O)) hyperconjugation in 2-equatorial, (3) the lack of computational evidence for sigma(S-C) --> sigma*(S-O) stereoelectronic interaction in 2-equatorial, and (4) the relevance of a repulsive electrostatic interaction between sulfur atoms in 1,3-dithiane sulfoxide, which apparently counterbalances any nS --> sigma*(C-S(O)) stabilizing hyperconjugative interaction and accounts for the lower than expected enthalpy of formation for sulfoxide 2. PMID:15287796

Roux, María Victoria; Temprado, Manuel; Jiménez, Pilar; Dávalos, Juan Z; Notario, Rafael; Martín-Valcárcel, Gloria; Garrido, Leoncio; Guzmán-Mejía, Ramón; Juaristi, Eusebio

2004-08-01

226

Calorimetric studies of solvates of C{sub 60} and C{sub 70} with aromatic solvents  

SciTech Connect

To improve the understanding of the solution properties of C{sub 60} and C{sub 70} in aromatic solvents, binary systems of C{sub 60} and C{sub 70} with benzene, toluene, 1,2- and 1,3-dimethylbenzene, 1,2,4,- and 1,3,5-trimethylbenzene, bromobenzene, and 1,2- and 1,3-dichlorobenzene were studied using differential scanning calorimetry, solution calorimetry, and thermogravimetry. Solid solvates with different compositions were identified in many of the systems. The solvates were characterized by composition and by the temperature and the enthalpy of the incongruent melting transition. Enthalpies of solution of C{sub 60} in toluene, 1,2-dimethylbenzene, 1,2- and 1,3-dichlorobenzene, and 1,2,4-trimethylbenzene and of C{sub 70} in 1,2-dimethylbenzene and in 1,2- and 1,3-dichlorobenzene were determined. The formation-incongruent melting of solid solvates causes maxima in the temperature-solubility curves of fullerenes in aromatic solvents. Trends in solubility behavior of fullerenes were discussed in terms of thermodynamics of solution and solvate formation.

Korobov, M.V.; Mirakyan, A.L.; Avramenko, N.V. [Moscow State Univ. (Russian Federation). Dept. of Chemistry] [Moscow State Univ. (Russian Federation). Dept. of Chemistry; Olofsson, G. [Lund Univ. (Sweden)] [Lund Univ. (Sweden); Smith, A.L. [Drexel Univ., Philadelphia, PA (United States). Chemistry Dept.] [Drexel Univ., Philadelphia, PA (United States). Chemistry Dept.; Ruoff, R.S. [Washington Univ., St. Louis, MO (United States). Physics Dept.] [Washington Univ., St. Louis, MO (United States). Physics Dept.

1999-02-25

227

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

PubMed

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

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

2011-01-01

228

Micro-machined calorimetric biosensors  

DOEpatents

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.

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

229

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  

Microsoft Academic Search

We present the final installment of an intensive 13 year study of variations of the optical continuum and broad Hbeta emission line in the Seyfert 1 galaxy NGC 5548. The database consists of 1530 optical continuum measurements and 1248 Hbeta measurements. The Hbeta variations follow the continuum variations closely, with a typical time delay of about 20 days. However, a

B. M. Peterson; P. Berlind; R. Bertram; K. Bischoff; N. G. Bochkarev; N. Borisov; A. N. Burenkov; M. Calkins; L. Carrasco; V. H. Chavushyan; R. Chornock; M. Dietrich; V. T. Doroshenko; O. V. Ezhkova; A. V. Filippenko; A. M. Gilbert; J. P. Huchra; W. Kollatschny; D. C. Leonard; W. Li; V. M. Lyuty; Yu. F. Malkov; T. Matheson; N. I. Merkulova; V. P. Mikhailov; M. Modjaz; C. A. Onken; R. W. Pogge; V. I. Pronik; B. Qian; P. Romano; S. G. Sergeev; E. A. Sergeeva; A. I. Shapovalova; O. I. Spiridonova; J. Tao; S. Tokarz; J. R. Valdes; V. V. Vlasiuk; R. M. Wagner; B. J. Wilkes

2002-01-01

230

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 Astrophysics Data System (ADS)

We present the final installment of an intensive 13 year study of variations of the optical continuum and broad H? emission line in the Seyfert 1 galaxy NGC 5548. The database consists of 1530 optical continuum measurements and 1248 H? measurements. The H? 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~L1/2ion. Moreover, the apparently linear nature of the correlation between the H? response time and the nonstellar optical continuum Fopt arises as a consequence of the changing shape of the continuum as it varies, specifically Fopt~F0.56UV.

Peterson, B. M.; Berlind, P.; Bertram, R.; Bischoff, K.; Bochkarev, N. G.; Borisov, N.; Burenkov, A. N.; Calkins, M.; Carrasco, L.; Chavushyan, V. H.; Chornock, R.; Dietrich, M.; Doroshenko, V. T.; Ezhkova, O. V.; Filippenko, A. V.; Gilbert, A. M.; Huchra, J. P.; Kollatschny, W.; Leonard, D. C.; Li, W.; Lyuty, V. M.; Malkov, Yu. F.; Matheson, T.; Merkulova, N. I.; Mikhailov, V. P.; Modjaz, M.; Onken, C. A.; Pogge, R. W.; Pronik, V. I.; Qian, B.; Romano, P.; Sergeev, S. G.; Sergeeva, E. A.; Shapovalova, A. I.; Spiridonova, O. I.; Tao, J.; Tokarz, S.; Valdes, J. R.; Vlasiuk, V. V.; Wagner, R. M.; Wilkes, B. J.

2002-12-01

231

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

NASA Astrophysics Data System (ADS)

Context. The origin and site(s) of the r-process nucleosynthesis is(are) still not known with certainty, but complete, detailed r-element abundances offer our best clues. The few extremely metal-poor (EMP) stars with large r-element excesses allow us to study the r-process signatures in great detail, with minimal interference from later stages of Galactic evolution. CS 31082-001 is an outstanding example of the information that can be gathered from these exceptional stars. Aims: Here we aim to complement our previous abundance determinations for third-peak r-process elements with new and improved results for elements of the first and second r-process peaks from near-UV HST/STIS and optical UVES spectra. These results should provide new insight into the nucleosynthesis of the elements beyond iron. Methods: The spectra were analyzed by a consistent approach based on an OSMARCS LTE model atmosphere and the Turbospectrum spectrum synthesis code to derive abundances of heavy elements in CS 31082-001, and using updated oscillator strengths from the recent literature. Synthetic spectra were computed for all lines of the elements of interest to check for proper line intensities and possible blends in these crowded spectra. Our new abundances were combined with the best previous results to provide reliable mean abundances for the first and second-peak r-process elements. Results: We present new abundances for 23 neutron-capture elements, 6 of which - Ge, Mo, Lu, Ta, W, and Re - have not been reported before. This makes CS 31082-001 the most completely studied r-II star, with abundances for a total of 37 neutron-capture elements. We also present the first NLTE+3D abundance of lead in this star, further constraining the nature of the r-process. Based on observations made with the NASA/ESA Hubble Space Telescope (HST) through the Space Telescope Science Institute, operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555; and with the ESO Very Large Telescope at Paranal Observatory, Chile; Progr. ID 165.N-0276.Appendix A is available in electronic form at http://www.aanda.org

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

2013-02-01

232

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

National Technical Information Service (NTIS)

Since surfactants are often present as mixtures, effort is being made to understand the synergetic and competitive forces involving determining adsorption of surfactants from their mixtures. Adsorption of tetradecyl trimethyl ammonium chloride (TTAC) and ...

P. Somasundaran

1994-01-01

233

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

Microsoft Academic Search

The binding of aminoglycoside antibiotics to a broad range of macromolecular targets is coupled to protonation of one or more of the amino groups that typify this class of drugs. Determining how and to what extent this linkage influences the energetics of the aminoglycoside-macromolecule binding reaction requires a detailed understanding of the thermodynamics associated with the protonation equilibria of the

Christopher M. Barbieri; Daniel S. Pilch

2006-01-01

234

The Energetics of Hematite Dissolution in Iron Ore Melts for Assimilation in Commercial Sintering Processes: In Situ High Temperature Calorimetric Studies  

Microsoft Academic Search

Melting and crystallization of iron ores in mining applications are determined by the thermodynamic properties of the crystals and liquids in equilibrium. Iron ores are widely used for sinter production in Japan, Korea Russia, and Australia. In these sinter production plants, multiple ores can be blended together. Sintering is the second stage of a two step process in which iron

A. A. Navrotsky; R. Morcos; B. Ellis

2006-01-01

235

Determination of plutonium isotopic composition by gamma-ray spectroscopy  

SciTech Connect

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

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

1981-01-01

236

A fluorine bomb calorimetric determination of the standard molar enthalpy of formation of silicon disulfide SiS 2(cr) at the temperature 298.15 K. Enthalpies of dissociation of Si–S bonds  

Microsoft Academic Search

A synthesis of high-purity silicon disulfide SiS2is described, and the F.t.-Raman spectrum of the solid is reported for the first time. The standard massic energy of reaction of SiS2(cr) with fluorine was measured in a bomb calorimeter. The combustion reaction was shown to proceed as follows: SiS2(cr)+8F2(g)=SiF4(g)+2SF6(g). The derived standard molar enthalpy of formation is: ?fHmo(SiS2, cr, 298.15 K)=?(254.6±2.9) kJ·mol?1.

Iwona Tomaszkiewicz; G. A. Hope; P. A. G. O'Hare

1997-01-01

237

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

Microsoft Academic Search

The Gibbs free energies of formation of RuO2, OsO2 and IrO2 have been determined by measuring the chemical potentials of oxygen (?O2) defined by the reactions M + O2 = MO2, where M = Ru, Os. or Ir, using an electrochemical method with calcia-stabilized zirconia (CSZ) solid electrolytes. Measurements were attempted in the temperature ranges from ?870 K to 1620,

Hugh St. C. O'Neill; Johan Nell

1997-01-01

238

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

SciTech Connect

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

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

1988-02-09

239

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

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.

Somasundaran, P.

1995-03-01

240

Calorimetric, Viscosimetric, and Light Scattering Studies of the Aggregation of, and the Solubilization of Water by, Triton X-35 in n-Heptane.  

PubMed

The behavior of a nonionic surfactant TX-35 in solution in n-heptane in the presence and absence of added water has been examined using the microcalorimetric, viscosimetric, and quasielastic light scattering experimental methods. In this paper, we were interested in the aggregation process of the poly(oxyethylene) glycol alkylphenyl ether in n-heptane and in the solubilization of water in the reverse micelle of the surfactant (micellar solubilization). The analysis of the differential molar enthalpies of dilution of TX-35 in dried n-heptane has shown the occurrence of a gradual exothermic aggregation process on a very wide range of concentration which takes place at particular concentration so-called "operational CMC". This operational CMC value has been confirmed by viscosities measurements. The differential molar enthalpies of hydration of TX-35 were also measured and found to be exothermic. The maximal hydration ratio (w0) was found to be equal to 3.2 mol H2O per mole of TX-35 before the point of phase separation. The measurements of the variation of the amount of water contained in TX-35 solutions at different concentrations in n-heptane also show the occurence of a gradual aggregation process and confirm the value of the maximal hydration ratio already determined by microcalorimetry. In the absence of added water, from the quasielastic light scattering experiments, a mean diameter of the aggregates close to 45 Å has been determine, while in the presence of water, a mean diameter of 61 Å was detected and remained unchanged with increasing the hydration ratio indicating that the size of the aggregate is more influenced by the presence of water than by the amount. In the presence of water, it is relevant to discuss aggregates of lamellar or filament shape. Copyright 1999 Academic Press. PMID:9885255

Lagerge; Grimberg-Michaud; Guerfi; Partyka

1999-01-15

241

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

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.

Somasundaran, P.

1994-07-01

242

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

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.

Casteel, J. [Bartlesville Project Office, OK (United States)

1996-07-01

243

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

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.

Somasundaran, P.

1995-08-31

244

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

PubMed

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

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

2013-12-01

245

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

SciTech Connect

The aim of this contract is to elucidate the mechanisms underlying adsorption and surface precipitation of flooding surfactants on reservoir minerals. Effect of surfactant structure, surfactant combinations and other inorganic and polymeric species and solids of relevant mineralogy will also be determined. A multi-pronged approach consisting of micro & nano spectroscopy, microcalorimetry, electrokinetics, surface tension and wettability win be used to achieve the goals. The results of this study should help in controlling surfactant loss in chemical flooding and also in developing optimum structures and conditions for efficient chemical flooding processes. Adsorption/desorption of tetradecyl trimethyl ammonium chloride (TTAC) and sodium dodecyl sulfate (SDS)/octaethylene glycol mono n-decyl ether (C{sub 12}EO{sub 8}) surfactant mixtures at the kaolinite-water and alumina-water interfaces was studied during this quarter. The microstructure of the adsorbed layer was investigated using spectroscopic techniques. Effect of the hydrocarbon chain length of octaethylene glycol mono n-alkyl ether (C{sub n}EO{sub 8}) type nonionic surfactants on the adsorption of 1:1 mixtures of sodium dodecyl sulfate (SDS)/C{sub n}EO{sub 8} at the kaolinite/water interface was studied. The adsorption of SDS was enhanced by the presence of C{sub 10}EO{sub 8} but this effect was not as significant as those by C{sub 12--16}EO{sub 8}. Interestingly, once the hydrocarbon chain length of the nonionic surfactant exceeded that of the SDS (12) there was no further enhancement of SDS adsorption.

Somasundaran, P.

1994-02-22

246

Physicochemical determinants in the cellular responses to nanostructured amorphous silicas.  

PubMed

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

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

2012-07-01

247

Determining Densities  

NSDL National Science Digital Library

Students use two different methods to determine the densities of a variety of materials and objects. The first method involves direct measurement of the volumes of objects that have simple geometric shapes. The second is the water displacement method, used to determine the volumes of irregularly shaped objects. After the densities are determined, students create x-y scatter graphs of mass versus volume, which reveal that objects with densities less than water (floaters) lie above the graph's diagonal (representing the density of water), and those with densities greater than water (sinkers) lie below the diagonal.

Engineering K-Phd Program

248

Calorimetric Study of Thermal Denaturation of ?-Lactoglobulin  

Microsoft Academic Search

Effects of pH and milk constituents (milk ultrafiltrate and ~:-casein) on de- naturation of fl-lactoglobulin were investi- gated by a dynamic method based on dif- ferential scanning calorimetry. The appar- ent reaction order of \\/Ltactoglobulin de- naturation by the dynamic method was 2.0 over the pH range of 4.0 to 9.0, which is in fair agreement with results by other

Kwan Hwa Park; Daryl B. Lund

1984-01-01

249

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)

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.

Widgeon, Scarlett J.

250

Determining Concentration  

NSDL National Science Digital Library

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.

AMPS GK-12 Program,

251

Principer foer Kalorimetriska Bestaemningar av Vaermevaerden (Basic Principles for the Determination of Calorific Values),  

National Technical Information Service (NTIS)

Calorimetric measurements are based on the first law of thermodynamics and Newton's law of cooling. The classification of calorimeters is based on the thermal flow characteristics between the calorimeter proper and its environment (the thermostat or jacke...

M. Mansson

1988-01-01

252

Determining Densities  

NSDL National Science Digital Library

Students will use two different methods to determine the densities of a variety of materials and objects. The first method involves direct measurement of the volumes of objects that have simple geometric shapes, while the second uses the water displacement method to determine the volumes of irregularly-shaped objects. After the densities are determined, students will create x-y scatter graphs of mass versus volume, and these graphs will reveal that objects with densities less than water (floaters) lie above the graphâs diagonal, and those with densities greater than water (sinkers) lie below the diagonal. Pre-requisite Knowledge: * Students should be able to use rulers to measure lengths to the nearest millimeter, triple beam balances to measure masses to at least the nearest 0.1 gram, and graduated cylinders to measure liquids to at least the nearest 1 milliliter. * Students should be able to calculate the volumes of rectangular, cylindrical, and spherical solids. * Students should be able to graph points on an x-y coordinate grid.

Hebrank, Mary R.

2004-01-01

253

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

SciTech Connect

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.

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

1991-10-01

254

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

NASA Astrophysics Data System (ADS)

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

Ferraro, Christopher C.

255

Comparison of Measurement Techniques for Determining the Thermal Emittance of Coupons at Elevated Temperatures  

NASA Astrophysics Data System (ADS)

The development of a highly efficient nuclear space power system requires that all of the available thermal energy emitted from the General Purpose Heat Source (GPHS) modules (~250 thermal watts per module) be utilized in the most efficient manner. This includes defining the heat transfer/thermal gradient profile between the surface of a GPHS module and the surface of the selected converter's hot end. Control of the radiant heat transfer between the two surfaces can be achieved by regulating how efficiently the converter's hot end surface transfers heat compared to a perfect blackbody (i.e. its infrared emittance). By oxidizing and/or grit blasting the surface of candidate converter materials it is possible to increase their emittance. L-605 test specimens were WC grit blasted and heat treated at 1023K for 72hours in air and their emittance values at elevated temperatures up to ~1000K were determined using three different measurement techniques (Infrared Camera, Infrared Reflectometer, and a Calorimetric Test Method).

Kramer, Daniel P.; Miller, Roger G.; Howell, Edwin I.; Jaworske, Donald A.; Wilkes, Kenneth E.

2003-01-01

256

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

PubMed

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

Weng, Lindong; Elliott, Gloria D

2014-11-01

257

Nitrogen-fixing microoganisms in paddy soils XVI  

Microsoft Academic Search

1. It was proved that under aerobic shaking conditions of the system of R. capsulatus mixed with Az. agilis or R. capsulatus mixed with B. megaterium, the bacterial growth of both and the nitrogen fixation were promoted markedly, comp:ired with the non-shaking culture. However, in the system of R. capsulatus mixed with B. subtilis under aerobic shaking conditions. such remarkable

Tadashi Katayama; Michiharu Kobayashi; Azuma Okuda

1965-01-01

258

25 CFR 36.43 - Standard XVI-Student activities.  

...MINIMUM ACADEMIC STANDARDS FOR THE BASIC EDUCATION OF INDIAN CHILDREN AND NATIONAL CRITERIA FOR DORMITORY SITUATIONS Instructional...the school supervisor. The plan will include the purpose, structure, coordination, and planned types of fund-raising...

2014-04-01

259

25 CFR 36.43 - Standard XVI-Student activities.  

Code of Federal Regulations, 2012 CFR

...MINIMUM ACADEMIC STANDARDS FOR THE BASIC EDUCATION OF INDIAN CHILDREN AND NATIONAL CRITERIA FOR DORMITORY SITUATIONS Instructional...the school supervisor. The plan will include the purpose, structure, coordination, and planned types of fund-raising...

2012-04-01

260

25 CFR 36.43 - Standard XVI-Student activities.  

Code of Federal Regulations, 2013 CFR

...MINIMUM ACADEMIC STANDARDS FOR THE BASIC EDUCATION OF INDIAN CHILDREN AND NATIONAL CRITERIA FOR DORMITORY SITUATIONS Instructional...the school supervisor. The plan will include the purpose, structure, coordination, and planned types of fund-raising...

2013-04-01

261

25 CFR 36.43 - Standard XVI-Student activities.  

Code of Federal Regulations, 2010 CFR

...MINIMUM ACADEMIC STANDARDS FOR THE BASIC EDUCATION OF INDIAN CHILDREN AND NATIONAL CRITERIA FOR DORMITORY SITUATIONS Instructional...the school supervisor. The plan will include the purpose, structure, coordination, and planned types of fund-raising...

2010-04-01

262

25 CFR 36.43 - Standard XVI-Student activities.  

Code of Federal Regulations, 2011 CFR

...MINIMUM ACADEMIC STANDARDS FOR THE BASIC EDUCATION OF INDIAN CHILDREN AND NATIONAL CRITERIA FOR DORMITORY SITUATIONS Instructional...the school supervisor. The plan will include the purpose, structure, coordination, and planned types of fund-raising...

2011-04-01

263

70 Bryonora 46 (2010) ZAJMAV BRYOFLORISTICK NLEZY XVI.  

E-print Network

, spolecn s Oligotrichum hercynicum, Diplophyllum obtusifolium, Nardia scalaris, Cephalozia bicuspidata, 3 ca 20 dm2 , spolecn s Oligotrichum hercynicum, 11. 9. 2010, leg. S. Koval, M. Zmrhalová, herb. SUM

Kucera, Jan

264

The Herschel Virgo Cluster Survey - XVI. A cluster inventory  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

265

Life Story of His Holiness the XVI Gyalwa Karmapa  

E-print Network

a meeting with the Prime Minister, Shrimati Indira Gandhi, at which time the Government of India expressed its willingness to offer a plot of land in New Delhi to His Holi- nels for the construction of a mo :lastery. In 1977, His Holiness made...

Rinpoche, Jamgon Kongtrul

1982-01-01

266

Planck intermediate results. XVI. Profile likelihoods for cosmological parameters  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

267

List of Tables xiv List of Figures xvi  

E-print Network

Earth's Climate and Some Basic Principles 3 1.1 One of the Greatest Crimes of the 20th Century of the Crime. . . . . . . . . . . . . . . 14 1.7 Hubbert's Peak and the End of Cheap Oil . . . . . . . . . . 15 The Brower-Cousteau Model of the Earth 173 7.1 How Heavily Do We Weigh upon the Earth? . . . . . . . . . 173

Russo, Bernard

268

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

ERIC Educational Resources Information Center

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

Flaherty, Toni

269

64 Bryonora 38 (2006) NOV BRYOLOGICK LITERATURA XVI.  

E-print Network

. & Hadiuzzaman S. (2006): Acrocarpous mosses of Bangladesh. XI. Family: Bartramiaceae ­ 1. ­ Bangladesh Journal: Vegetation-controlled or climate-driven mechanisms? ­ Climatic Change 77: 415­429. #12;Bryonora 38 (2006) 65

Kucera, Jan

270

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

SciTech Connect

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

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

1993-09-01

271

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

PubMed

A new ultrahigh vacuum microcalorimeter for measuring heats of adsorption and adsorption-induced surface reactions on complex single crystal-based model surfaces is described. It has been specifically designed to study the interaction of gaseous molecules with well-defined model catalysts consisting of metal nanoparticles supported on single crystal surfaces or epitaxial thin oxide films grown on single crystals. The detection principle is based on the previously described measurement of the temperature rise upon adsorption of gaseous molecules by use of a pyroelectric polymer ribbon, which is brought into mechanical?thermal contact with the back side of the thin single crystal. The instrument includes (i) a preparation chamber providing the required equipment to prepare supported model catalysts involving well-defined nanoparticles on clean single crystal surfaces and to characterize them using surface analysis techniques and in situ reflectivity measurements and (ii) the adsorption?reaction chamber containing a molecular beam, a pyroelectric heat detector, and calibration tools for determining the absolute reactant fluxes and adsorption heats. The molecular beam is produced by a differentially pumped source based on a multichannel array capable of providing variable fluxes of both high and low vapor pressure gaseous molecules in the range of 0.005-1.5 × 10(15) molecules?cm(-2)?s(-1) and is modulated by means of the computer-controlled chopper with the shortest pulse length of 150 ms. The calorimetric measurements of adsorption and reaction heats can be performed in a broad temperature range from 100 to 300 K. A novel vibrational isolation method for the pyroelectric detector is introduced for the reduction of acoustic noise. The detector shows a pulse-to-pulse standard deviation ?15 nJ when heat pulses in the range of 190-3600 nJ are applied to the sample surface with a chopped laser. Particularly for CO adsorption on Pt(111), the energy input of 15 nJ (or 120 nJ?cm(-2)) corresponds to the detection limit for adsorption of less than 1.5 × 10(12) CO molecules?cm(-2) or less than 0.1% of the monolayer coverage (with respect to the 1.5 × 10(15) 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. PMID:21361615

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

2011-02-01

272

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

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.

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

273

A Calorimetric Study of (PRASEODYMIUM(1.5) CERIUM(0.5)) STRONTIUM(2) COPPER(2) Niobium OXYGEN(10), Praseodymium BARIUM(2) COPPER(2) Niobium OXYGEN(8) and the Effects of Oxygen on CARBON(60) (buckminsterfullerene)  

NASA Astrophysics Data System (ADS)

As in the RBa_2Cu _3O_{7-delta} copper oxide system the Pr member of the (R _{1.5}Ce_{0.5 })Sr_2Cu_2 NbO10 system is isostructural but nonsuperconducting. The compound (Pr_{1.5}Ce_ {0.5})Sr_2Cu _2NbO10 is even more anomalous as there are two magnetic ordering transitions seen in susceptibility data. One occurs at 17 K and is attributed to ordering in Pr moments. The second transition at 53 K is believed to be the result of a re-ordering of the Cu^{2+} moments which order antiferromagnetically at much higher temperatures in these systems. The heat capacity of (Pr_{1.5 }Ce_{0.5})Sr _2CU_2NbO 10 and a structurally related compound PrBa_2Cu _2NbO_8 are reported from 5 K to 350 K. The data for (Pr_{1.5 }Ce_{0.5})Sr _2Cu_2NbO 10 show no evidence of either magnetic transition, an unprecedented result for the 17 K Pr order. Comparing the characteristics of these heat capacity measurements and other heat capacity and magnetic measurements reported previously we argue that the unusual characteristics of (Pr_ {1.5}Ce_{0.5} )Sr_2Cu_2 NbO10 are predominantly due to the structural differences between these systems. The heat capacity of C_{60 }, from 5 K to 350 K, is examined as a function of oxygen exposure. A method is devised, using a thermal gravimetric analysis study, which gives a qualitative test, based on x-ray diffraction results, for structural breakdown. The measured heat capacity of pristine C_{60 } is consistent with previous reports for the size (18 J/mol K) and position (260 K) of the structural phase transition and for the existence of a glass transition near 87 K. Exposure to oxygen at room temperature produces no change in either transition temperature as might be expected if oxygen were a bulk contaminant at room temperature and were attached to the molecular structure. It is also not clear from these data whether there is a difference in the entropy associated with the transitions. The same C60 sample was subsequently exposed to oxygen at 175 ^circC on a time scale which produced only a partial oxygenation (determined by mass change). The face-centered cubic (fcc) to simple cubic transition was no longer observed. The x-ray diffraction pattern however was unchanged from the room temperature fcc lattice pattern. These heat capacity data were taken on a calorimeter designed and built in this laboratory for measurements in the 4 K to 400 K temperature range. An overview of the calorimeter design and measurement techniques are given.

Barnes, David Edward

274

Early orbit determination  

Microsoft Academic Search

Orbit determination for near real time monitoring of satellite movement based on limited observations is discussed. For geostationary satellites this early orbit determination requirement arises after injection into geostationary transfer orbit, apogee motor firing, and larger orbit maneuvers during the on-station phase. Early orbit determination is hampered by the limited amount of data caused by nonavailability of the tracking system.

S. Pallaschke

1986-01-01

275

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

SciTech Connect

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.

Dubose, F.

2012-02-21

276

Evaluation of the differential scanning calorimetric method for fat solids  

Microsoft Academic Search

Denison et al. (1) recently reported a method for measuring the per cent solids in fats using the Differential Scanning Calorimeter\\u000a (DSC). The present work evaluates that method using the Perkin Elmer DSC-1, compares it with nuclear magnetic resonance (NMR)\\u000a and dilatation methods, and extends it to hard butters. Although the method gave excellent interlaboratory agreement with\\u000a soft fats, extension

Alan P. Bentz; Barbara G. Breidenbach

1969-01-01

277

Calorimetric study of carbon partitioning from martensite into austenite steel  

SciTech Connect

Quenching and partitioning (Q and P) has been developed as a novel steel heat treatment to produce advanced high-strength microstructures consisting of a martensitic matrix containing significant amounts of retained austenite. Austenite stabilization is hypothesized to result from decarburization of the martensite and transport into the austenite. Differential scanning calorimetry was employed to study Q and P microstructures. Two exothermic events were observed when heating a Q and P sample from room temperature to 600 deg. C. An activation energy suggesting a mechanism controlled by carbon diffusion in bcc iron is obtained for the first peak which is believed to be associated with carbon partitioning. The second peak is believed to be associated with austenite decomposition.

De Moor, Emmanuel [Advanced Steel Processing and Products Research Center, Colorado School of Mines, Golden, Colorado 80401 (United States); Department of Materials Science and Engineering, Ghent University, Technologiepark 903, B-9052 Zwijnaarde (Belgium); Foejer, Cecilia [ArcelorMittal Research Industry Gent, OCAS NV, ArcelorMittal, J. Kennedylaan 3, B-9060 Zelzate (Belgium); Penning, Jan [Department of Materials Science and Engineering, Ghent University, Technologiepark 903, B-9052 Zwijnaarde (Belgium); Clarke, Amy J. [Materials Science and Technology Division, Los Alamos National Laboratory, Mail Stop G770, Los Alamos, New Mexico 87545 (United States); Speer, John G. [Advanced Steel Processing and Products Research Center, Colorado School of Mines, Golden, Colorado 80401 (United States)

2010-09-01

278

The International Space Station CALorimetric Electron Telescope (CALET) Experiment  

NASA Astrophysics Data System (ADS)

The CALET space experiment, currently being developed by collaborators in Japan, Italy and the United States, will study electrons to 20 TeV, gamma rays above 10 GeV and nuclei with Z=1 to 40 up to 1,000 TeV during a five year mission on the International Space Station. The instrument consists of a particle charge identification module, a thin imaging calorimeter (3 r.l. in total) with tungsten plates interleaving scintillating fiber planes, and a thick calorimeter (27 r.l.) composed of lead tungstate logs. CALET has the depth, imaging capabilities and energy resolution for excellent separation between hadrons, electrons and gamma rays and is expected to be launched in 2014 as an attached payload on the International Space Station (ISS) Japanese Experiment Module -- Exposed Facility (JEM-EF). CALET will investigate possible nearby sources of high energy electrons, study the details of galactic particle propagation and search for dark matter signatures. This presentation summarizes the expected instrument design and performance.

Wefel, John P.

2012-03-01

279

A calorimetric study of aluminium alloy AA7075  

Microsoft Academic Search

The differential scanning calorimetry (DSC) technique has been used to examine the precipitation process in the commercial Al-Zn-Mg-Cu alloy AA-7075. In general the results are in good agreement with previous DSC data on a similar alloy and can be related to the precipitation process observed by electron microscopy. However, an additonal precipitation process has been detected at low temperatures, which

D. J. Lloyd; M. C. Chaturvedi

1982-01-01

280

Simulated Performance of the CALorimetric Electron Telescope (CALET) experiment  

NASA Astrophysics Data System (ADS)

CALET is a detector planned to be on board the Japanese Experiment Module Exposed Facility(JEM-EF) of the International Space Station. The CALET mission aims at revealing unresolved problems in high energy phenomena of the Universe by carrying out a precise measurement of high energy gamma-rays in 20 MeV - TeV, electrons in 1 GeV - 20 TeV and hadronic cosmic rays in 10 GeV - 1000 TeV. It is now in a phase A study of the JAXA program. Main detector is composed of an IMaging Calorimeter (IMC), a Total AbSorption Calorimeter (TASC), SIlicon Array (SIA) and Scintillator Anti-Coincidence System (SACS) to observe various kind of particles in very wide energy range. The total absorber thickness is 31 r.l. for electromagnetic particles and 1.6 m.f.p. for protons. Monte Carlo simulation study has being carried out for optimization of the detector performance in observing each kind of particles. We use the EPICS, Electron-Photon Induced Cascade Simulator in a detector, code in which dpmjet3 is adopted as nuclear interaction model. We obtained following performance about the observation of very high energy (< 100 GeV) electrons, which is a main target of the CALET experiment: 1) Proton contamination in the observed electrons is less than 2 % without serious electron loss. 2) Energy resolution is better than a few %. 3) Angular resolution is better than 1 deg. 4) Effective geometrical factor is about 7000 cm2 sr. We will also present the simulated performance of the CALET experiment in observing other particles.

Akaike, Yosui; Kasahara, Katsuaki; Torii, Shoji; Shimizu, Yuki; Taira, Koichi; Yoshida, Kenji

281

Calorimetric thermometry of meteoritic troilite: Preliminary thermometer relationships  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

282

Calorimetric thermometry of meteoritic troilite: A feasibility study  

NASA Technical Reports Server (NTRS)

Two solid-state phase transitions in troilite (FeS) can be readily measured by differential scanning calorimetry (DSC) on samples of only a few milligrams. Troilite from the Mundrabilla iron meteorite displays a DSC fingerprint which is distinct from that of terrestrial troilite from Del Norte Co., California; their response to subsequent heating also differ significantly. Further work may establish whether troilite thermometry of meteorites is possible using DSC.

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

1993-01-01

283

Calorimetric studies of small-molecule adsorption to carbon nanotubes  

E-print Network

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 ...

Glab, Kristin Lena

2009-01-01

284

Calorimetric studies of the state of water in seed tissues.  

PubMed

To understand the physical state of water in hydrating biological tissues, thermodynamic properties of water in cotyledons of pea and soybean with moisture contents ranging from 0.01 g H(2)O/g dw to 1.0 g H(2)O/g dw were studied using differential scanning calorimetry. The heat capacity of the tissues increased abruptly at moisture contents above 0.08 and 0.12 g H(2)O/g dw for soybean and pea cotyledons, respectively. Melting transitions of water were observed at moisture contents >0.23 and 0.26 g H(2)O/g dw for soybean and pea. However, freezing of water was not observed unless moisture contents exceeded 0.33-0.35 g H(2)O/g dw. In both seed tissues, the temperatures of the freezing and melting varied with moisture content and showed hysterisis. The energy of the transition also varied with moisture content and was similar to the heats of fusion and crystallization of pure water only at moisture contents >0.54 and 0.58 gH(2)O/g dw for soybean and pea seeds, respectively. The thermal properties of water change distinctly as seed moisture content changes: at least five states or water can be identified. PMID:19431782

Vertucci, C W

1990-12-01

285

Calorimetric Tg and Heat Capacity of Polystyrene Thin Films  

NASA Astrophysics Data System (ADS)

The glass transition temperature and the absolute heat capacity of polystyrene thin films were measured using the step-scan method of differential scanning calorimetry. The glass transition temperature is found to be depressed 8 K for a sample of stacked 17 nm thick films and Tg is depressed 3 K for a sample of stacked 61 nm thick films. The results are consistent with data in the literature for the Tg depression in supported polystyrene films although our films are expected to be ``freely standing'' for the initial DSC scan. In addition, the absolute heat capacity in both the liquid and glassy states decreases with decreasing film thickness, the step change in heat capacity at the glass transition temperature decreases with decreasing film thickness, and the breadth of the transition region increases with decreasing film thickness. The effect of heating the thin film samples to 135 C, approximately 40 C above their Tgs, is a slight increase in the absolute heat capacity and a slight increase in Tg. No significant changes occur on subsequent scans. The ``thin film'' morphology is maintained in spite of scanning to above Tg where the stacked film sample is expected to lose its free surface.

Koh, Yung; McKenna, Gregory; Simon, Sindee

2006-03-01

286

Calorimetric measurements of a Yang-Koldamasov device  

E-print Network

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 ...

Novosad, Jennifer

2007-01-01

287

Calorimetric studies of the thermal denaturation of cytochrome c peroxidase  

SciTech Connect

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

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

1988-04-05

288

Calorimetric investigation of relaxation processes in disordered semiconductors  

SciTech Connect

The comparative study of relaxation processes in amorphous hydrogenated (a-Si:H) and porous silicon (PS) by use of differential scanning calorimetry (DSC) measurements is presented. Films of a-Si:H were deposited by RF glow discharge of two gas mixtures (10% SiH{sub 4} + 90% H{sub 2}) and (5% SiH{sub 4} + 95% He). PS films have been prepared by electrochemical etching of 1{Omega}{center_dot}cm (p- PS) and of 0.01{Omega}{center_dot}cm (p+ PS) p-type Si substrates. The DSC traces were recorded during the heating of samples at a constant rate of 10 C/min from 20 to 570 C in an Ar atmosphere. All investigated samples present a low temperature exothermic effect with a maxima within 120--280 V. At higher temperatures (T > 300 C) a second exothermic effect is observed for a-Si:H films prepared from both hydrogen and helium diluted silane mixtures while two endothermic effects are observed for PS samples. Analysis of the low temperature exothermic effects has been performed, and focused on the relaxation of weak Si-Si bonds which are the features of both amorphous hydrogenated and porous silicon. It was shown that the endothermic effect connected with hydrogen effusion from PS at higher temperatures is compensated by exothermic structural rearrangement in the case of a-Si:H.

Budaguan, B.G.; Aivazov, A.A.; Sazonov, A.Yu. [Moscow Inst. of Electronic Technology (Russian Federation). Dept. of Microtechnology

1996-12-31

289

Calorimetric detection of neutral-atom content of ion beam  

NASA Technical Reports Server (NTRS)

Energy deposition technique deduces neutral-beam flux or dose from measured values of incremental resistance increases in platinum wire passed through beam. Steady-state heat balance analysis led to equivalent neutral-beam current. Method was used to detect neutral-atom content of 60-keV argon ion beam.

Roberts, A. S., Jr.

1974-01-01

290

Calorimetric studies on the strontium–uranium–oxygen system  

Microsoft Academic Search

Enthalpy increment measurements on Sr3U11O36(s) and Sr3U2O9(s) were carried out using a Calvet micro-calorimeter. The enthalpy increment values were least squares analyzed with the constraints that H0(T)?H0(298.15 K) at 298.15 K equals zero and C0p,m(298.15 K) equals 1064.2 and 301.8 J K?1mol?1 for Sr3U11O36(s) and Sr3U2O9(s), respectively. The dependence of enthalpy increments with temperature can be given asH0(T)?H0(298.15K)(Jmol?1)=?304152+962.72T(K)+177.63×10?3T2(K)+3.954×105\\/T(K),(Sr3U11O36(s),299.0?T(K)?1000),H0(T)?H0(298.15K)(Jmol?1)=?115817+319.18T(K)+58.01×10?3T2(K)+46.201×105\\/T(K),(Sr3U2O9(s),299.0?T(K)?1000).Thermodynamic functions for

Smruti Dash; Ziley Singh; R. Prasad; V. Venugopal

2000-01-01

291

Calorimetric studies on the strontium-uranium-oxygen system  

NASA Astrophysics Data System (ADS)

Enthalpy increment measurements on Sr 3U 11O 36(s) and Sr 3U 2O 9(s) were carried out using a Calvet micro-calorimeter. The enthalpy increment values were least squares analyzed with the constraints that H 0(T)-H 0(298.15 K) at 298.15 K equals zero and C 0p,m(298.15 K) equals 1064.2 and 301.8 J K -1mol -1 for Sr 3U 11O 36(s) and Sr 3U 2O 9(s), respectively. The dependence of enthalpy increments with temperature can be given as H 0(T)-H 0(298.15 K ) ( J mol -1)=-304152+962.72T ( K)+177.63×10 -3T 2 ( K)+3.954×10 5/T ( K), ( Sr3U11O36( s),299.0?T ( K)?1000), H 0(T)-H 0(298.15 K ) ( J mol -1)=-1 15 817+319.18T ( K)+58.01×10 -3T 2 ( K)+46.201×10 5/T ( K), ( Sr3U2O9( s),299.0?T ( K)?1000). Thermodynamic functions for Sr 3U 11O 36(s) and Sr 3U 2O 9(s), have been generated using the ? fH 0m(298.15 K), ? fG 0m( T) and S 0m(298.15 K) values, either calculated in this study or from the literature.

Dash, Smruti; Singh, Ziley; Prasad, R.; Venugopal, V.

2000-03-01

292

Calorimetric study of melted DNA glass Jessica Valle-Orero  

E-print Network

at a temperature below the glass transition. Introducing the fictive temperature to characterise the glass allows liquid (equilibrium) to glass (non-equilibrium) without being able to crystalise. As the temperature structure on the cooling rate can be described by the lim- iting fictive temperature, T f [1]. The glass

Boyer, Edmond

293

Micro Determination of Calcium  

Microsoft Academic Search

Hildebrand and Reilly1 have recently described a complexometric titration method for the determination of calcium: the indicator used, `Calcon', is superior to `Solochrome' black in that calcium can be determined independently of magnesium, and, unlike the murexide method, a sharp end-point is obtained. All three methods employ ethylenediamine tetraacetic acid. The purpose of the present communication is to direct attention

A. B. Gilbert

1959-01-01

294

Determiners: A Relational Perspective  

Microsoft Academic Search

In this paper we examine from a semantic point of view a class of ex- pressions variously referred to as determiners, quantifiers, or articles. Our treatment of the meaning of these expressions reflects an idea which has its origin in the work of Montague (1970), Lewis (1972), Geach (1972), and Cresswell (1973): determiners are to be interpreted as two-place relations

Frans Zwarts; Nederlands Instituut; Rijksuniversiteit Groningen

295

Randomness, Determinism and Computability.  

National Technical Information Service (NTIS)

This paper discusses the meaning and relationship of randomness and determinism. A fundamental development of chaotic dynamical systems is given with examples. Such systems are seen to exhibit randomness in the usual sense of unpredictability. The formal ...

E. J. Wegman

1987-01-01

296

Determinants of Project Success.  

National Technical Information Service (NTIS)

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 org...

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

1974-01-01

297

Electrochemical Determination of Glutathione  

Microsoft Academic Search

Procedures were developed for determining glutathione by voltammetry and coulometric titration with electrogenerated oxidants using the biamperometric indication of the titration end-point. Possible mechanisms of the glutathione reaction with electrogenerated halogens are discussed. Microgram amounts of glutathione can be determined in model solutions with an RSD of 1–2%. The oxidation wave of glutathione in the voltammogram is observed at 0.95

G. K. Budnikov; G. K. Ziyatdinova; Ya. R. Valitova

2004-01-01

298

Solids mass flow determination  

DOEpatents

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

Macko, Joseph E. (Hempfield Township, Westmoreland County, PA)

1981-01-01

299

Potentiometric determination of the gibbs energies of formation of SrZrO3 and BaZrO3  

NASA Astrophysics Data System (ADS)

The Gibbs free energies of formation of strontium and barium zirconates have been determined in the temperature range 960 to 1210 K using electrochemical cells incorporating the respective alkaline-earth fluoride single crystals as solid electrolytes. Pure strontium and barium monoxides were used in the reference electrodes. During measurements on barium zirconate, the oxygen partial pressure in the gas phase over the electrodes was maintained at a low value of 18.7 Pa to minimize the solubility of barium peroxide in the monoxide phase. Strontium zirconate was found to undergo a phase transition from orthorhombic perovskite (o) with space group Cmcm; D{2h/17} to tetragonal perovskite (t) having the space group 14/ mcm; D {4h/18} at 1123 (/+- 10) K. Barium zirconate does not appear to undergo a phase transition in the temperature range of measurement. It has the cubic perovskite (c) structure. The standard free energies of formation of the zirconates from their component binary oxides AO ( A = Sr, Ba) with rock salt (rs) and ZrO2 with monoclinic (m) structures can be expressed by the following relations: SrO (rs) + ZrO2 (m) ? SrZrO3 (o) ? G° = -74,880 - 14.2 T (/+-200) J mol-1 SrO (rs) + ZrO2 (m) ? SrZrO3 (t) ? G° = -73,645 - 15.37 T (/+-200) J mol-1 BaO (rs) + ZrO2 (m) ? BaZrO4 (c) ? G° = -127,760-1.79 T (/+-250) J mol-1 The results of this study are in reasonable agreement with calorimetric measurements reported in the literature. Systematic trends in the stability of alkaline-earth zirconates having the stoichiometry AZrO3 are discussed.

Jacob, K. T.; Waseda, Y.

1995-08-01

300

Determining Error Management Strategies  

NASA Astrophysics Data System (ADS)

A statistical model has been designed to interpret experimental burst error data in determining an optimal error management strategy for optical media. The model is based on the theory of a Non-homogeneous Poisson Point Process. The assumptions for the evaluation of defects capable of causing error bursts in a user's data stream (burst starts and burst lengths) will be discussed. With this model it is possible to determine the optimal error management strategy to achieve any desired system performance, including depth of interleaving, error correcting capability and certification fencing for excessively long error bursts.

Brown, Winton E.; Earman, Allen M.

1988-06-01

301

Determinants of project success  

NASA Technical Reports Server (NTRS)

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.

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

1974-01-01

302

Determination of Fat Content  

NASA Astrophysics Data System (ADS)

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).

Carpenter, Charles

303

EMPOWERING DIGITAL SELF DETERMINATION  

E-print Network

: Communication and Digital Media 2. Data Context and Digital Personas 3. Personal Data: Use, Reuse-sector discussion about people's relation to the digital ecosystem, which depends on personal data to deliver valueEMPOWERING DIGITAL SELF DETERMINATION Symposium Summary Stanford University, Summer 2012 #12

Das, Rhiju

304

Determining the Hubble Constant  

NSDL National Science Digital Library

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.

Copeland, Cush

2012-07-11

305

Spectrophotometric determination of mangiferin  

Microsoft Academic Search

Summary  A spectrophotometric method is proposed for determining mangiferin in a crystalline powder and in sweetvetch herbage. The\\u000a relative accuracy of the method is ± 0.34% for the powder and ± 2.63% for the herbage.

B. A. Krivut; N. A. Fedyunina; S. I. Kocherga; S. V. Rusakova

1976-01-01

306

Radio determination satellite service  

Microsoft Academic Search

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

Robert D. Briskman

1990-01-01

307

Determination and predictibility  

E-print Network

.g. planetary resonances, [Laplace, Sur les inégalités séculaires, 1784-87]) #12;Poincaré's determinism God predictability · Crucial: no absolute scale of measure (as under a discrete grid) #12;Summary: Laplace

Longo, Giuseppe

308

Determining Optimal College Locations  

ERIC Educational Resources Information Center

Location can be a critical determinant of the success of a college. Central Place Theory, as developed in geographic studies of population distribution patterns, can provide insights into the problem of evaluating college locations. In this way preferences of students can be balanced against economic, academic, and political considerations.…

Schofer, J. P.

1975-01-01

309

Determinants of collateral  

Microsoft Academic Search

We estimate a comprehensive model of the determinants of collateral in loans extended to business firms. We use a panel data on a sample of bank loans to Spanish firms from 1984 to 2002. Consistent with theories that view collateral as a solution to adverse selection problems, our results provide direct evidence of a negative association between collateral and a

Gabriel Jiménez; Vicente Salas; Jesús Saurina

2006-01-01

310

Determining Plausible Forecast Outcomes  

NSDL National Science Digital Library

The content of this lesson will assist the forecaster with the third step of the forecast process, namely, determining plausible forecast outcomes forward in time. The lesson will highlight the role of probabilistic forecast tools to assess the degree of uncertainty in a forecast, as well as suggest an approach for evaluating past and present model performance.

Comet

2010-08-17

311

What Determines Leadership Style?  

Microsoft Academic Search

This project examines selected traits valued in friends by educated individuals, and it seeks to determine if these valued traits vary by gender, race, and generational cohort. A literature review reveals that variations in leadership attributes are evident among these traits. In order to test the broad applicability of this literature, data were taken from the General Social Survey (GSS).

Apryl Silva

2009-01-01

312

Determining TOC in Waters  

ERIC Educational Resources Information Center

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)

Kehoe, Thomas J.

1977-01-01

313

Determination of balloon drag  

NASA Technical Reports Server (NTRS)

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

Conrad, George R.; Robbins, Edward J.

1991-01-01

314

Determination of Moisture Content  

NASA Astrophysics Data System (ADS)

The moisture (or total solids) content of foods is important to food manufacturers for a variety of reasons. Moisture is an important factor in food quality, preservation, and resistance to deterioration. Determination of moisture content also is necessary to calculate the content of other food constituents on a uniform basis (i.e., dry weight basis). The dry matter that remains after moisture analysis is commonly referred to as total solids.

Nielsen, S. Suzanne

315

Interplanetary orbit determination  

NASA Technical Reports Server (NTRS)

The logistical aspects of orbit determination (OD) in the interplanetary phase of the Mariner Mars 1971 mission are described and the working arrangements for the OD personnel, both within the Navigation Team and with outside groups are given. Various types of data used in the OD process are presented along with sources of the data. Functional descriptions of the individual elements of the OD software and brief sketches of their modes of operation are provided.

Zielenbach, J. W.; Acton, C. H.; Born, G. H.; Breckenridge, W. G.; Chao, C. C.; Duxbury, T. C.; Green, D. W.; Jerath, N.; Jordan, J. F.; Mottinger, N. A.

1973-01-01

316

Complexometric Determination of Calcium  

Microsoft Academic Search

\\u000a Ethylenediaminetetraacetate (EDTA) complexes with numerous mineral ions, including calcium and magnesium. This reaction can\\u000a be used to determine the amount of these minerals in a sample by a complexometric titration. Endpoints in the titration are\\u000a detected using indicators that change color when they complex with mineral ions. Calmagite and eriochrome black T (EBT) are\\u000a such indicators that change from blue

S. Suzanne Nielsen

2010-01-01

317

POLAROGRAPHIC DETERMINATION OF RUTHENIUM  

Microsoft Academic Search

A method for the polarographic determination of ruthenium is discussed ; using basic sodium gluconate as the supporting electrolyte. The half-wave ; potential is --0.67v veisus the saturtred calomel electrode for 0.1 F sodium ; gluconate at pH 14. For these conditions the diffusion current constant, I, is ; 1.18 (maximum rather than average current). This constant is applicable for

D. T. Sawyer; R. J. Kula; A. L. Budd

1962-01-01

318

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

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.

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

2003-01-01

319

The Determination of Downwash  

NASA Technical Reports Server (NTRS)

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

Diehl, Walter S

1921-01-01

320

Satellite altitude determination uncertainties  

NASA Technical Reports Server (NTRS)

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

Siry, J. W.

1972-01-01

321

Determination of Survivable Fires  

NASA Technical Reports Server (NTRS)

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.

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

322

Gears: Determining Angular Velocity  

NSDL National Science Digital Library

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.

AMPS GK-12 Program,

323

ICESat Precision Orbit Determination  

NASA Astrophysics Data System (ADS)

Following the successful launch of the Ice, Cloud and land Elevation Satellite (ICESat) on January 13, 2003, 00:45 UTC, the GPS receiver on ICESat was turned on successfully on Jan. 17, 2003. High quality GPS data were collected since then to support Precision Orbit Determination (POD) activities. ICESat carries Geoscience Laser Altimeter System (GLAS) to measure ice-sheet topography and associated temporal changes, as well as cloud and atmospheric properties. To accomplish the ICESat science objectives, the position of the GLAS instrument in space should be determined with an accuracy of 5 cm and 20 cm in radial and horizontal components, respectively. This knowledge is acquired by the POD activities using the data collected by the GPS receiver on ICESat and the ground-based satellite laser ranging (SLR) data. It has been shown from pre-launch POD studies that the gravity model error is the dominant source of ICESat orbit errors. The predicted radial orbit errors at the ICESat orbit (600 km altitude) based on pre-launch gravity models, such as TEG-4 and EGM-96, are 7-15 cm. Performance of these gravity models and the recent gravity models from GRACE on ICESat POD were evaluated. The radial orbit accuracy is approaching 1-2 cm level with the GRACE gravity model. This paper also summarizes POD activities at Center for Space Research (CSR), which is responsible to generate ICESat POD products.

Rim, H.; Yoon, S.; Webb, C. E.; Kim, Y.; Schutz, B. E.

2003-12-01

324

Complexometric Determination of Calcium  

NASA Astrophysics Data System (ADS)

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

Nielsen, S. Suzanne

325

Environment. Two biggest determinants.  

PubMed

In China, the chair of the Environmental Protection Committee of the National People's Congress, who was the director of the National Environmental Protection Agency for 10 years, notes that population growth puts much pressure on the environment. The Chinese extensively use agricultural and natural resources to meet their basic needs: food, clothing, and shelter. Population control is needed to preserve the environment. In fact, population control and environmental protection are the 2 most significant determinants of sustainable economic growth, social stability, and balanced development in China. The Chinese government allocates 0.8% of its annual gross national product to control of environmental pollution. As a result, urban pollution has been reduced. China takes part in international cooperative efforts. PMID:12287781

Zhang, Y

1994-03-01

326

Tracer for circulation determinations  

SciTech Connect

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.

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

1985-03-19

327

Subcritical multiplication determination studies  

SciTech Connect

A series of measurements and improvements to computational techniques are in progress at Los Alamos National Laboratory that are aimed at better understanding the determination of the reactivity of subcritical systems from measurements of the apparent multiplication of the system. Such studies are being performed in order to improve the special nuclear material (SNM) assays of unknown systems such as those encountered in SNM safeguards, arms-control verification, imports of foreign-generated SNM, etc. Improved techniques and understanding are needed since measured multiplication is not always an invariant characteristic of a subcritical system, especially if one has a system with no significant intrinsic internal neutron source that is illuminated nonuniformly with an external source (i.e., a non-normal mode system).

Estes, G.P.; Goulding, C.A.

1995-07-01

328

VSOP-2 Orbit Determination  

NASA Astrophysics Data System (ADS)

Precise orbit determination (POD) is a key factor to enable phase referencing observations with Astro-G. A POD accuracy of 30 cm is required for efficient X-band phase referencing observations, accuracy of 6 cm for K-band observations, and accuracy of 3 cm for Q-band observations. For the POD, Astro-G will be equipped with a GPS/Galileo receiver and a SLR (Satellite Laser Ranging) retroreflector array. Four POD antennas will be equipped on four sides of the satellite body, to cover all directions. The SLR will be used as a complement to the GPS at middle-to-high altitude. Because the refroreflector array should always face to the Earth direction, it will be set up on the Ka-link antenna gimbal. The most significant perturbing force for the Astro-G is solar radiation pressure (SRP). The reflectivity of each surface component should be preliminary measured in detail to model the SRP. The estimated achievable POD accuracy at apogee is 10 ˜ 30 cm in nominal case. Phase referencing observations in K- or Q-band can be performed if the enough amount of SLR tracking data can be obtained at high altitudes.

Takeuchi, H.; VSOP-2 Orbit Determination Sub-Working Group

2009-08-01

329

Cryogenic Laser Calorimetry for Impurity Analysis  

NASA Technical Reports Server (NTRS)

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.

Swimm, R. T.

1985-01-01

330

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

Microsoft Academic Search

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

J. G. Doran; C. L. Gottshall

1978-01-01

331

Optimization of microfluidic flow sensors for different flow ranges by FEM simulation  

Microsoft Academic Search

Finite element simulation and post-processing results of calorimetric type microfluidic mass flow sensors are presented. The output characteristics of a calorimetric flow sensor are functions of the geometrical position of the temperature sensor elements. A given flow sensor (with a given technology on a given substrate) can be optimized for different flow ranges by determining the position of the temperature

Ferenc Ender; Hunor Sántha; Vladimír Székely

2010-01-01

332

Determinants of lemming outbreaks.  

PubMed

Population outbreaks in tundra rodents have intrigued scientists for a century as a result of their spectacular appearances and their general lessons in ecology. One outstanding question that has led to competing hypotheses is why sympatric lemmings and voles differ in regularity and shape of their outbreaks. Lemming outbreaks may be lost for decades while vole populations maintain regular population cycles. Moreover, when lemming populations eventually irrupt, they do so more steeply than the vole populations. Norwegian lemmings exhibited a large-scale outbreak synchronously with gray-sided voles in Finnmark, northern Fennoscandia, during 2006 to 2007 for the first time in two decades. Analyses of spatial variability of this outbreak across altitudinal gradients allowed us to identify determinants of the contrasting lemming and vole dynamics. The steeper lemming outbreak trajectories were caused by breeding and population growth during winter, when nonbreeding vole populations consistently declined. The differently shaped lemming and vole outbreaks appear to result from a particular demographic tactic of lemmings that evolved as an adaptation to the long and cold Arctic-Alpine winters. The lemming outbreak amplitude increased with altitude and vole density, indicating that lemming outbreaks are jointly facilitated by low temperatures and apparent mutualism with voles mediated by shared predators. High sensitivity to variation in climate and predation is likely to be the reasons why lemmings have more erratic population dynamics than sympatric voles. The combination of continued climatic warming and dampened vole cycles is expected to further decrease the frequency, amplitude, and geographic range of lemming outbreaks in tundra ecosystems. PMID:21245340

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

2011-02-01

333

Abnormalities of human sex determination  

Microsoft Academic Search

Summary Cytogenetic and molecular studies in patients with abnormalities of sex determination have been the key to the isolation and investigation of candidates for the primary testis determining factor (TDF). A gene, SRY, isolated from the sex determining region of the Y chromosome within 5 kilobases of the pairing segment boundary, has been characterized recently which fulfils the expectations of

M. A. Ferguson-Smith

1992-01-01

334

Voyager orbit determination at Jupiter  

Microsoft Academic Search

This paper summarizes the Voyager 1 and Voyager 2 orbit determination activity extending from encounter minus 60 days to the Jupiter encounter, and includes quantitative results and conclusions derived from mission experiences. The major topics covered include an identification and quantification of the major orbit determination error sources and a review of salient orbit determination results from encounter, with emphasis

J. K. Campbell; S. P. Synnott; G. J. Bierman

1983-01-01

335

Voyager orbit determination at Jupiter  

Microsoft Academic Search

This paper summarizes the Voyager 1 and Voyager 2 orbit determination activity extending from encounter minus 60 days to the Jupiter encounter, and includes quantitative results and conclusions derived from mission experience. The major topics covered include an identifica- tion and quantification of the major orbit determination error sources and a review of salient orbit determination results from encounter, with

JAMES K. CAMPBELL; STEPHEN P. SYNNOTT; GERALD J. BIERMAN

1983-01-01

336

Direct determination of the enthalpy of formation of MoB in synthesis from simple substances in an SHS system  

NASA Astrophysics Data System (ADS)

In a calorimetric bomb equipped with an electric microfurnace for heating a sample, self-propagating high-temperature synthesis (SHS) of molybdenum boride is realized in accordance with the reaction Mo (c) +B (amorph.)=MoB (c); the enthalpy of this reaction is measured, and the standard enthalpy of formation of molybdenum boride from metal molybdenum and crystaline boron is calculated: ?f H 0 (MoB,c,?,?)=103.9?1.2kJ/mole.

Lavut, E. G.; Chelovskaya, N. V.; Kashireninov, O. E.

1993-10-01

337

Voyager orbit determination at Jupiter  

NASA Technical Reports Server (NTRS)

This paper summarizes the Voyager 1 and Voyager 2 orbit determination activity extending from encounter minus 60 days to the Jupiter encounter, and includes quantitative results and conclusions derived from mission experiences. The major topics covered include an identification and quantification of the major orbit determination error sources and a review of salient orbit determination results from encounter, with emphasis on the Jupiter approach phase orbit determination. Special attention is paid to the use of combined spacecraft-based optical observations and earth-based radiometric observations to achieve accurate orbit determination during the Jupiter encounter approach phase.

Campbell, J. K.; Synnott, S. P.; Bierman, G. J.

1983-01-01

338

Erroneous theories of sex determination  

Microsoft Academic Search

Throughout the major part of history, theories of sex determination had to be formulated in the absence of knowledge of ova and spermatozoa. The most persistent theory postulated that males are associated with the right parental side and females with the left side. At the end of the 19th century, sex was thought to be determined by nutrition. Recent findings

U Mittwoch

1985-01-01

339

Cytokine determinants of viral tropism  

Microsoft Academic Search

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

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

2009-01-01

340

Electrochemical Determination of Lipoic Acid  

Microsoft Academic Search

Procedures for determining lipoic acid by voltammetry and coulometric titration with electrogenerated halogens using the biamperometric indication of the titration end-point were developed. Possible mechanisms of lipoic acid oxidation with electrogenerated halogens are discussed. Microgram amounts of lipoic acid were determined in model solutions with an RSD of 1–2%. The analytical range of lipoic acid found by voltammetry at a

G. K. Ziyatdinova; G. K. Budnikov; V. I. Pogorel'tsev

2004-01-01

341

Self-Determination. Feature Issue.  

ERIC Educational Resources Information Center

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

IMPACT, 1994

1994-01-01

342

Method for Determining Artillery Position  

NASA Technical Reports Server (NTRS)

A method is described for determining the position of artillery in which a circle of four closely spaced microphones is located at two measurement sites for acoustic radio direction finding of muzzle blasts. A method for determining the position of artillery using this procedure is discussed.

Meuser, Wilfried

1988-01-01

343

The Resurgence of Biological Determinism.  

ERIC Educational Resources Information Center

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

Segal, Elizabeth A.; Kilty, Keith M.

1998-01-01

344

Mouse Genetics: Determining gene function  

E-print Network

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

Goldschmidt, Christina

345

determine  

E-print Network

local search procedure scans the set of crucial vertices C(f) changing their ..... possible movements move(u, v) for all v ? D and performs the best one in terms of .... this latter application of PR are considered to be candidates to enter ES, and ...

Mauricio G. C. Resende,,,

346

Method of determining glass durability  

DOEpatents

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.

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

1998-12-08

347

Method of determining glass durability  

DOEpatents

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.

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

1998-01-01

348

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

E-print Network

causal structures (and their knowledge) contain everything up to the very natures of particulars. Since (experimentation, etc.). He also insists (rightly, we think) that one cannot have knowledge of the concrete causal structures without also having knowledge of the natures of things that make them up, and vice versa

Chakravartty, Anjan

349

Volume XVI, No. 4 A publication of the U.S. Army Installation Management Agency  

E-print Network

-7 A quick look�The Army Installation Design Standards (IDS) by Larry Black, Gary W. Burns, and Lawrence and ABA Accessibility Guidelines 9 New Army Standard for Company Operation Facilities by John Scharl 10 by Linda Smith 17 New Army standard/standard design for consolidated Fire/Police/Safety facilities 18

US Army Corps of Engineers

350

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

SciTech Connect

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

Tandon, S.K.; Srivastava, L.

1985-01-01

351

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

E-print Network

). Se enferma de los pulmones y paulatinamente muere, pero antes hace un pacto con su amigo Hilaco (Lucas Achirico) de volver el día de los muertos al cumplirse un año de su fallecimiento. "La mina es una madre que atrapa a sus hijos... y los consume..., los personajes profesan no sólo no saber donde están ubicados geográficamente (barca en búsqueda de terra incognita) sino también cuestionan si están vivos o muertos, ya que la "condición" de náufrago es el de un inexistente, un ausente para el...

Marrero, Marí a Teresa

2002-04-01

352

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

E-print Network

SPiRiT for RCI projects by Annette Stumpf 10-11 More resources to improve project sustainability 11 Systems by Dan Andrew 28-29 Korea receives HOMES training by Bradford Smith 30 Implementing Yardi Voyager

US Army Corps of Engineers

353

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

ERIC Educational Resources Information Center

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

Human Engineering Inst., Cleveland, OH.

354

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

Federal Register 2010, 2011, 2012, 2013

...acceptable medical sources,'' such as nurse-practitioners, physicians' assistants, naturopaths, chiropractors, audiologists, occupational therapists (OTs), physical therapists (PTs), and psychiatric social workers (PSWs). We cannot...

2011-09-12

355

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

E-print Network

, economic risk, operational risk, legal risk, security risk, and so forth. We conduct risk analysis, using either offensive or defensive approaches to identify and assess risk. Offensive approaches are concerned

Stølen, Ketil

356

Volume XVI, Issue 3 Spring 2012 Thesis Presentations..........p.7  

E-print Network

a mixture of sadness to be leaving and anticipation to be returning home with new ideas and experiences, BOSTON COLLEGE see Italy page 3 Freshman Scholars Embrace Italian Culture The Class of 2015 poses to share with our fellow BC students. #12;2 Social Justice Project A Panel on Immigration By Francesca Mc

Huang, Jianyu

357

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

E-print Network

............................................................................................................................................................ 22 Geothermal heat pumps and energy savings performance contracting save money, environment in Korea Region by James C. Hamilton III 23 Fort Knox saves money through intervention by Edward J. Gerstner 23 Program helps save energy, money by Bob Quick 27 Residents recycle with ease at underground depot by Lisa

US Army Corps of Engineers

358

MANUSCRITO 975 DE LA BIBLIOTECA DE MANUEL DE FALLA: UNA NUEVA FUENTE POLIFÓNICA DEL SIGLO XVI  

Microsoft Academic Search

En el Archivo Manuel de Falla se ha localizado un manuscrito de 1575 aproximadamente. Esta antología de más de un centenar de obras sacras y profanas, es fiel reflejo de las tendencias y gustos musicales de la época ya que contiene obras de siete importantes compositores españoles y trece extranjeros, la mayoría de los cuales mantenía estrechos lazos con la

Michael Christoforidis; Juan Ruiz Jiménez

1994-01-01

359

i6e Anne (Tome XVI). Mars 1936. N 153 LE' LAITREVUE GNRALE DES QUESTIONS LAITIRES  

E-print Network

Mémoires originaux: TALCE-NIEDRA (Dagmara). - La catalase des bactéries d'acide lactique . . . . . 225 M . . .'. . .... 335 .Nécrologie, M. H�NNE- BERG. . 335 l\\f�l\\10IRES ORIGINAUX (1) LB LAIT, 1936 LA CATALASE DES Directeur Dr. A' KIRCHENSTEINS;, On se sert assez souvent de la réaction de la 'catalase pour déter- miner

Boyer, Edmond

360

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

ERIC Educational Resources Information Center

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

Jirak, Mary Ann; Lucas, John A.

361

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

Microsoft Academic Search

Diffuse idiopathic skeletal hyperostosis (DISH) is a common systemic disorder characterised by the ossification of the anterior\\u000a longitudinal spinal ligament involving at least three contiguous vertebrae and by diffuse extraspinal enthesopathies. The\\u000a condition is associated with the male sex and with advanced age; its aetiology is uncertain, but seems to be related to obesity\\u000a and diabetes. The most recent studies

Valentina Giuffra; Sara Giusiani; Antonio Fornaciari; Natale Villari; Angelica Vitiello; Gino Fornaciari

2010-01-01

362

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

ERIC Educational Resources Information Center

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

AAWCJC Quarterly, 1992

1992-01-01

363

Amino acids and peptides. XVI. Synthesis of a tetrapeptide sequence (A9-A12) of glucagon  

Microsoft Academic Search

A synthesis of the tetrapeptide sequence As-Ag of glucagon is described that employs various blocking groups, coupling procedures, and routes. The threonyl-phenylalanyl-threonyl-seryl sequence A5-A8 in the hyperglycemic hormone, glucagon (Foa and Galansino, 1962), has been prepared by three dif- ferent groups within the past four years (Beyerman and Bontekoe, 1964; Schroder and Gibian, 1962; Wunsch and Wendleberger, 1964). In connection

EARLE R. CALEY; LOWELL W. SHANK; BRIAN O. HANDFORD

1968-01-01

364

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.

2008-02-07

365

Method for Determining Artillery Position  

NASA Technical Reports Server (NTRS)

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.

Fischer, Johannes; Meuser, Wilfried

1988-01-01

366

Ultrasonic Determination of Steel Structures.  

National Technical Information Service (NTIS)

In the research project 'Determination of steel structures by means of ultrasound' methods are developed for the non-destructive structure characterization with scattered ultrasound. Measurements were made at about 200 steel samples with frequencies betwe...

K. Goebbels, S. E. Greter, P. Hoeller

1977-01-01

367

Determining Cropland Cash Rental Arrangements  

E-print Network

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...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...

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

1999-06-23

368

Determining Cropland Share Rental Arrangements  

E-print Network

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...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...

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

1999-06-23

369

Determinants of heart rate variability  

Microsoft Academic Search

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

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

1996-01-01

370

[Determination of zimarin in urine].  

PubMed

Private technique of extraction isolation and purification, chromatographic detection and photometric determination of zimarin in urine is suggested. Detection limit is 0.01 mg, determination limit is 0.1 mg of glycoside in 100 ml of urine. Method makes it possible to detect 66-80% of zimarin added to 100 ml of urine in quantities 0.5-0.1 mg. PMID:2528227

Skorzova, Z B; Shniakina, G P

1989-01-01

371

Quantitatively determined self-incompatibility  

Microsoft Academic Search

It has been reported that incomplete self-incompatibility could be determined in Borago officinalis by many genes. Simple ten-gene models for such enforced cross-fertilization have been developed and their properties examined by computer simulation. Mutation rates necessary to maintain a given level of variability in small populations are high, as already determined theoretically for oligogenic self-incompatibility systems. However, the extent of

O. Mayo; C. R. Leach

1989-01-01

372

Iodimetric determination of 2-mercaptopyrimidines  

Microsoft Academic Search

A new method for the determination of 2-mercaptopyrimidines, using their reaction with iodine in neutral and alkaline medium, is presented. The determinability range in the volumetric titration, in phosphate buffer with starch as an indicator, was found to be equal to 40–1000 ?mol for 2-mercaptopyrimidine (I) and 100–2000 ?mol for 2-mercapto-4-methylpyrimidine (II), and 200–2000 ?mol for 4,6-dimethyl-2-mercaptopyrimidine (III). In the

Witold Ciesielski; Robert Zakrzewski; Anna Krenc

1998-01-01

373

Experimental Determination of Dawsonite Stability and Reactivity: Implications for Geological CO2 Sequestration  

SciTech Connect

Over the last decade, a significant research effort has focused on determining the feasibility of sequestering large amounts of CO{sub 2} in deep, permeable geologic formations to reduce carbon dioxide emissions to the atmosphere. Most models indicate that injection of CO{sub 2} into deep sedimentary formations will lead to the formation of various carbonate minerals, including the common phases calcite (CaCO{sub 3}), dolomite (CaMg(CO{sub 3}){sub 2}), magnesite (MgCO{sub 3}), siderite (FeCO{sub 3}), as well as the far less common mineral, dawsonite (NaAlCO{sub 3}(OH){sub 2}). Nevertheless, the equilibrium and kinetics that control the precipitation of stable carbonate minerals are poorly understood and few experiments have been performed to validate computer codes that model CO{sub 2} sequestration. In order to reduce this uncertainty we measured the solubility of synthetic dawsonite according to the equilibrium: NaAlCO{sub 3}(OH){sub 2(cr)} + 2H{sub 2}O{sub 1} {r_equilibrium}Al(OH){sub 4}{sup -} + HCO{sub 3}{sup -} + Na{sup +} + H{sup +}, from under- and oversaturated solutions at 50-200 C in basic media at 1.0 mol {center_dot} kg{sup -1} NaCl. The solubility products (Q{sub s}) obtained were extrapolated to infinite dilution to obtain the solubility constants (K{sub s}{sup o}). Combining the fit of these logK{sub s}{sup o} values and fixing {Delta}C{sub pJ}{sup o} at -185.5J {center_dot} mol{sup -1} {center_dot} K{sup -1} at 25 C, which was derived from the calorimetric data of Ferrante et al. [Ferrante, M.J., Stuve, J.M., and Richardson, D.W., 1976. Thermodynamic data for synthetic dawsonite. U.S. Bureau of Mines Report Investigation, 8129, Washington, D.C., 13p.], the following thermodynamic parameters for the dissolution of dawsonite were calculated at 25 C: {Delta}G{sub r}{sup o} = 102.1 kJ {center_dot} mol{sup -1}, {Delta}H{sub r}{sup o} = 97.0 kJ {center_dot} mol{sup -1} and {Delta}s{sub r}{sup o} = -17.1 J {center_dot} mol{sup -1} {center_dot} K{sup -1}. Subsequently, we were able to derive values for the Gibbs energy of formation {Delta}{sub {line_integral}}G{sup 0}{sub 298.15} = -1782 {+-} 2 kJ {center_dot} mol{sup -1}), enthalpy of formation ({Delta}{sub {line_integral}}H{sup o}{sub 298.15} = -1960 {+-} 7 kJ {center_dot} mol{sup -1}) and entropy (S{sup o}{sub 298.15} = 121 {+-} 2 J {center_dot} mol{sup -1} {center_dot} K{sup -1}) of dawsonite. These results are within the combined experimental uncertainties of the values reported by Ferrante et al. (1976). Predominance diagrams are presented for the dawsonite/boehmite and dawsonite/bayerite equilibria at 100 C in the presence of a saline solution with and without silica-containing minerals.

Benezeth, Pascale [Laboratoire des Mecanismes et Transferts en Geologie, Toulouse, France; Palmer, Donald [ORNL; Anovitz, Lawrence {Larry} M [ORNL; Horita, Juske [ORNL

2007-01-01

374

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

E-print Network

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$...

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

2014-01-01

375

50 CFR 100.23 - Rural determinations.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Rural determinations. 100...MONUMENTS SUBSISTENCE MANAGEMENT REGULATIONS FOR PUBLIC...Determinations § 100.23 Rural determinations. ...Board has determined all communities and areas to be rural in accordance...

2013-10-01

376

A Predictive Attitude Determination Algorithm  

NASA Technical Reports Server (NTRS)

In this paper, a new and efficient algorithm is developed for attitude determination from vector observations. The new algorithm, called the Predictive Attitude Determination (PAD) algorithm, is derived from a general nonlinear predictive filter approach. Traditional deterministic algorithms are shown to be suboptimal for anisotropic measurement errors. The major advantage of the PAD algorithm is that it can be easily applied to the case where anisotropic measurement errors exist. Also, an analytical expression is derived for the steady-state attitude error covariance, which is shown to be equivalent to the optimal covariance derived from maximum likelihood techniques. Simulation studies indicate that the new algorithm is able to accurately determine the attitude of a spacecraft, even for radically anisotropic measurement errors.

Markley, F. Landis; Crassidis, John L.

1997-01-01

377

Method for determining artillery position  

NASA Technical Reports Server (NTRS)

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.

Fischer, Johannes; Loges, Werner; Meuser, Wilfried

1988-01-01

378

Decoherence, determinism and chaos revisited  

SciTech Connect

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.

Noyes, H.P.

1994-11-15

379

Method for determining damping coefficients  

NASA Astrophysics Data System (ADS)

There is disclosed a method for determining damping coefficients, the method including the steps of providing a damper assembly including a bar of known parameters, and a viscous damper, wherein a first end of the bar is disposed in the viscous damper while the second end of the bar is free, applying a known force to the second end of the bar in a direction toward the first end of the bar, measuring the response function of the assembly, comprising the ratio of the bar acceleration to the applied force, determining the eigenvalues of the response function, and from the eigenvalues computing the damping coefficient of the damper assembly.

Austin, Stephen A.; Hull, Andrew J.; Hurdis, David A.; Kasper, Kent D.

1995-05-01

380

Iodimetric determination of organolead compounds.  

PubMed

A sensitive, rapid and accurate titrimetric method has been developed for the determination of 50-5000 mug of ethyl-lead or phenyl-lead compounds, based on their oxidation with a chloroform solution of iodine, removal of the excess of iodine, oxidation of the resulting iodide with bromine, and iodometric titration of the iodate formed. The coefficient of variation does not exceed 1.2% for amounts > 1000 mug of the organolead compound, but increases to 2.8% for the 50-mug level. The ethyl- and phenyl-lead compounds can be determined independently in mixtures. PMID:18964424

Amin, D; Al-Allaf, T A

1987-10-01

381

Cohesin in determining chromosome architecture  

SciTech Connect

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.

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

382

Videos Determine the Moon's "g"  

ERIC Educational Resources Information Center

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…

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

2011-01-01

383

Upper Bounds for Regularized Determinants.  

National Technical Information Service (NTIS)

Let E be a holomorphic vector bundle on a compact Kahler manifold X. If the authors fix a metric h on E, they get a Laplace operator delta acting upon smooth sections of E over X. Using the zeta function of delta, one defines its regularized determinant d...

H. Gillet, C. Soule

1997-01-01

384

The Determinants of Cardiac Output  

NSDL National Science Digital Library

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.

Anderson, Robert M.

2012-01-25

385

Freedom and Determinism: A Framework  

Microsoft Academic Search

Thoughts about freedom and determinism have engaged philosophers since the days of ancient Greece., On the one hand, we generally regard ourselves as free and autonomous beings who are responsible for the ac-tions that we perform. But this idea of ourselves appears to conflict with a variety of attitudes that we also have about the inevitable workings of the world

Joseph Keim Campbell; Michael O'Rourke; David Shier

386

Determinants of Homonegativity in Europe  

Microsoft Academic Search

This paper analyzes macro-determinants of negative attitudes toward homosexuality in 31 European societies. Using the European Values Study (EVS) 1999\\/2000, carried out on national probability samples, we tested the effects of tradition, modernization, and postmodernization on homonegativity. According to the findings, social distance toward homosexual persons was predicted by Eastern Orthodox religion, a greater degree of urbanization, economic development, and

Aleksander Štulhofer; Ivan Rimac

2009-01-01

387

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

388

DETERMINATION OF THORIUM IN ORES  

Microsoft Academic Search

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

S. Sekine; T. Mochizuki

1961-01-01

389

Determining the Extragalactic Distance Scale  

NSDL National Science Digital Library

In this activity students find a number of Cepheid variables in the galaxy M100. They then use their periods, average apparent magnitudes, and their Period-Luminosity relationships, in order to determine the distance to M100. Then students can estimate the Hubble constant to find the age of the universe.

Dutkevitch, Diane

2004-07-16

390

Quantitatively determined self-incompatibility  

Microsoft Academic Search

It is shown by simulation that a hypothetical multilocus, quantitatively determined self-incompatibility system, whether gametophytic or sporophytic, should maintain variability in small populations at a higher level than would panmixia. Studies of more than 20 isozyme loci show that borage has almost no variability.

C. R. Leach; O. Mayo

1991-01-01

391

Presence: concept, determinants, and measurement  

Microsoft Academic Search

The concept of presence, i.e. the sensation of 'being there' in a mediated environment, has received substantial attention from the virtual reality community, and is becoming increasingly relevant both to broadcasters and display developers. Although research into presence is still at an early stage of development, there is a consensus that presence has multiple determinants. To identify and test which

Wijnand A. IJsselsteijn; Huib de Ridder; Jonathan Freeman; Steve E. Avons

2000-01-01

392

Iodimetric determination of 2-mercaptopyrimidines.  

PubMed

A new method for the determination of 2-mercaptopyrimidines, using their reaction with iodine in neutral and alkaline medium, is presented. The determinability range in the volumetric titration, in phosphate buffer with starch as an indicator, was found to be equal to 40-1000 mumol for 2-mercaptopyrimidine (I) and 100-2000 mumol for 2-mercapto-4-methylpyrimidine (II), and 200-2000 mumol for 4,6-dimethyl-2-mercaptopyrimidine (III). In the volumetric titration in alkaline medium, with the potentiometric end-point detection, the determinability range is 50-250 mumol for 2-mercapto-4-methylpyrimidine (II), 50-500 mumol for 4,6-dimethyl-2-mercaptopyrimidine (III), 20-250 mumol for 4,5-diamino-2,6-dimercaptopyrimidine (IV), and 20-1000 mumol for 2-thioorotic acid (V). In the coulometric titration, using the biamperometric end-point detection, 0.1-4.0 mumol of 2-mercaptopyrimidine (I) and 0.1-5.0 mumol of 2-thioorotic acid (V) were successfully determined. PMID:18967379

Ciesielski, W; Zakrzewski, R; Krenc, A; Zielinska, J

1998-11-01

393

Determinants of Nuclear Weapons Proliferation  

Microsoft Academic Search

Nuclear weapons proliferation is a topic of intense interest and concern among both academics and policy makers. Diverse opinions exist about the determinants of proliferation and the policy options to alter proliferation incentives. We evaluate a variety of explanations in two stages of nuclear proliferation, the presence of nuclear weapons production programs and the actual possession of nuclear weapons. We

Dong-Joon Jo; Erik Gartzke

2007-01-01

394

Self-Determination and Choice  

ERIC Educational Resources Information Center

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

Wehmeyer, Michael L.; Abery, Brian H.

2013-01-01

395

Genetic modification and genetic determinism  

Microsoft Academic Search

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

David B. Resnik; Daniel B. Vorhaus

2006-01-01

396

Determination of the B lifetime  

NASA Astrophysics Data System (ADS)

We have determined the lifetime of B-hadrons produced in e + e - annihilation into multihadronic final states, by measuring the impact parameter of the track with respect to the centre of the interaction region. Two different analyses of the data were performed and gave compatible results. The lifetime is ? B =1.8{-0.4/+0.5}±0.4 ps.

Bartel, W.; Becker, L.; Cords, D.; Felst, R.; Haidt, D.; Knies, G.; Krehbiel, H.; Laurikainen, P.; Magnussen, N.; Meinke, R.; Naroska, B.; Olsson, J.; Schmidt, D.; Steffen, P.; Dietrich, G.; Hagemann, J.; Heinzelmann, G.; Kado, H.; Kawagoe, K.; Kleinwort, C.; Kuhlen, M.; Petersen, A.; Ramcke, R.; Schneekloth, U.; Weber, G.; Ambrus, K.; Bethke, S.; Dieckmann, A.; Elsen, E.; Heintze, J.; Hellenbrand, K. H.; Komamiya, S.; von Krogh, J.; Lannert, P.; Matsumura, H.; Rieseberg, H.; Spitzer, J.; Wagner, A.; Bowdery, C.; Finch, A.; Foster, F.; Hughes, G.; Nye, J.; Allison, J.; Ball, A. H.; Barlow, R. J.; Chrin, J.; Duerdoth, I. P.; Greenshaw, T.; Hill, P.; Loebinger, F. K.; MacBeth, A. A.; McCann, H.; Mills, H. E.; Murphy, P. G.; Stephens, K.; Warming, P.; Glasser, R. G.; Skard, J. A. J.; Wagner, S. R.; Zorn, G. T.; Cartwright, S. L.; Clarke, D.; Marshall, R.; Middleton, R. P.; Kawamoto, T.; Kobayashi, T.; Takeda, H.; Takeshita, T.; Yamada, S.

1986-09-01

397

Determination of skin repigmentation progression.  

PubMed

In this paper, we describe an image processing scheme to analyze and determine areas of skin that have undergone repigmentation in particular, during the treatment of vitiligo. In vitiligo cases, areas of skin become pale or white due to the lack of skin pigment called melanin. Vitiligo treatment causes skin repigmentation resulting in a normal skin color. However, it is difficult to determine and quantify the amount of repigmentation visually during treatment because the repigmentation progress is slow and moreover changes in skin color can only be discerned over a longer time frame typically 6 months. Here, we develop a digital image analysis scheme that can identify and determine vitiligo skin areas and repigmentation progression on a shorter time period. The technique is based on principal component analysis and independent component analysis which converts the RGB skin image into a skin image that represent skin areas due to melanin and haemoglobin only, followed by segmentation process. Vitiligo skin lesions are identified as skin areas that lack melanin (non-melanin areas). In the initial studies of 4 patients, the method has been able to quantify repigmentation in vitiligo lesion. Hence it is now possible to determine repigmentation progression objectively and treatment efficacy on a shorter time cycle. PMID:18002737

Nugroho, Hermawan; Fadzil, M H Ahmad; Yap, V V; Norashikin, S; Suraiya, H H

2007-01-01

398

Bone strength and its determinants  

Microsoft Academic Search

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,

P. Ammann; R. Rizzoli

2003-01-01

399

Performing Determinism: Disability Culture Poetry  

Microsoft Academic Search

“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

Petra Kuppers

2007-01-01

400

Determining Salinity by Simple Means.  

ERIC Educational Resources Information Center

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…

Schlenker, Richard M.

401

Quark mass determinations in QCD  

NASA Astrophysics Data System (ADS)

Recent progress on QCD sum rule determinations of the light and heavy quark masses is reported. In the light quark sector a major breakthrough has been made recently in connection with the historical systematic uncertainties due to a lack of experimental information on the pseudoscalar resonance spectral functions. It is now possible to suppress this contribution to the 1% level by using suitable integration kernels in Finite Energy QCD sum rules. This allows to determine the up-, down-, and strange-quark masses with an unprecedented precision of some 8-10%. In the heavy quark sector, the availability of experimental data in the vector channel, and the use of suitable multipurpose integration kernels allows to increase the accuracy of the charm- and bottom-quarks masses to the 1% level.

Dominguez, C. A.

2014-09-01

402

Low thrust orbit determination program  

NASA Technical Reports Server (NTRS)

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).

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

1972-01-01

403

System for determining aerodynamic imbalance  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

404

[Determination of aflatoxins in cheeses].  

PubMed

To investigate cheeses for the presence of aflatoxins we chose the very sensitive method of Tuinstra and Bronsgeest (1975) used for the determination of aflatoxin M1 in milk. The method was slightly modified and the presence of aflatoxins was determined in 54 samples of different cheeses. Aflatoxin M1 was found out in 24% of the investigated samples. Most of positive samples were found among the soft cheeses (53.8 3/4), then in processed cheeses (13.6%) and in hard cheeses (12.5%). Aflatoxin M1 was not found in the group of mouldy cheeses and Olomouc cake cheeses, which were investigated in a smaller range. Positive findings did not exceed concentrations of 10 ng per kg, i.e. they did not even reach the value of permissible concentration as proposed in the Czech Socialist Republic for foods (5 microgram per kg). PMID:106514

Bartos, J; Matyás, Z

1979-03-01

405

In-flight thrust determination  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

406

Spectrophotometric Determination of Steroid Oximes  

Microsoft Academic Search

A spectrophotometric procedure for the determination of steroid oximes is described utilizing 11?-hydroxy-iia-methyl-5?-pregnane -3, 20 -dione dioxime (I) and iia-hydroxy-progesterone dioxime (II) as models. The method is based on (a) acid hydrolysis to release hydroxylamine, (b) oxidation of hydroxylamine to nitrous acid with iodine, (c) diazotization of sulfanilic acid with the nitrous acid, (d) coupling of the diazonium compound with

Arlington A. Forist; Ray W. Judy

1974-01-01

407

Rate determination from vector observations  

NASA Technical Reports Server (NTRS)

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

Weiss, Jerold L.

1993-01-01

408

Spectrophotometric determination of phosphorus acid  

SciTech Connect

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

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

1987-03-01

409

Gender determination from pulpal tissue  

PubMed Central

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

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

2014-01-01

410

Geostationary orbit determination using SATRE  

NASA Astrophysics Data System (ADS)

A new strategy of precise orbit determination (POD) for GEO (Geostationary Earth Orbit) satellite using SATRE (SAtellite Time and Ranging Equipment) is presented. Two observation modes are proposed and different channels of the same instruments are used to construct different observation modes, one mode receiving time signals from their own station and the other mode receiving time signals from each other for two stations called pairs of combined observations. Using data from such a tracking network in China, the results for both modes are compared. The precise orbit determination for the Sino-1 satellite using the data from 6 June 2005 to 13 June 2005 has been carried out in this work. The RMS (Root-Mean-Square) of observing residuals for 3-day solutions with the former mode is better than 9.1 cm. The RMS of observing residuals for 3-day solutions with the latter mode is better than 4.8 cm, much better than the former mode. Orbital overlapping (3-day orbit solution with 1-day orbit overlap) tests show that the RMS of the orbit difference for the former mode is 0.16 m in the radial direction, 0.53 m in the along-track direction, 0.97 m in the cross-track direction and 1.12 m in the 3-dimension position and the RMS of the orbit difference for the latter mode is 0.36 m in the radial direction, 0.89 m in the along-track direction, 1.18 m in the cross-track direction and 1.52 m in the 3-dimension position, almost the same as the former mode. All the experiments indicate that a meter-level accuracy of orbit determination for geostationary satellite is achievable.

Lei, Hui; Li, ZhiGang; Yang, XuHai; Wu, WenJun; Cheng, Xuan; Yang, Ying; Feng, ChuGang

2011-09-01

411

42 CFR 422.566 - Organization determinations.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Organization determinations. 422.566 Section...MEDICARE ADVANTAGE PROGRAM Grievances, Organization Determinations and Appeals § 422.566 Organization determinations. (a)...

2010-10-01

412

36 CFR 242.23 - Rural determinations.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Rural determinations... SUBSISTENCE MANAGEMENT REGULATIONS FOR... § 242.23 Rural determinations...determined all communities and areas to be rural in accordance...of Subsistence Management. The...

2012-07-01

413

50 CFR 100.23 - Rural determinations.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Rural determinations... SUBSISTENCE MANAGEMENT REGULATIONS FOR... § 100.23 Rural determinations...determined all communities and areas to be rural in accordance...of Subsistence Management. The...

2012-10-01

414

36 CFR 242.23 - Rural determinations.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Rural determinations... SUBSISTENCE MANAGEMENT REGULATIONS FOR... § 242.23 Rural determinations...determined all communities and areas to be rural in accordance...of Subsistence Management. The...

2013-07-01

415

50 CFR 100.23 - Rural determinations.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Rural determinations... SUBSISTENCE MANAGEMENT REGULATIONS FOR... § 100.23 Rural determinations...determined all communities and areas to be rural in accordance...of Subsistence Management. The...

2011-10-01

416

36 CFR 242.23 - Rural determinations.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Rural determinations... SUBSISTENCE MANAGEMENT REGULATIONS FOR... § 242.23 Rural determinations...determined all communities and areas to be rural in accordance...of Subsistence Management. The...

2011-07-01

417

State determination in continuous measurement  

E-print Network

The possibility of determining the state of a quantum system after a continuous measurement of position is discussed in the framework of quantum trajectory theory. Initial lack of knowledge of the system and external noises are accounted for by considering the evolution of conditioned density matrices under a stochastic master equation. It is shown that after a finite time the state of the system is a pure state and can be inferred from the measurement record alone. The relation to emerging possibilities for the continuous experimental observation of single quanta, as for example in cavity quantum electrodynamics, is discussed.

A. C. Doherty; S. M. Tan; A. S. Parkins; D. F. Walls

1999-03-09

418

Reactor vital equipment determination techniques  

SciTech Connect

The Reactor Vital Equipment Determination Techniques program at the Los Alamos National Laboratory is discussed. The purpose of the program is to provide the Nuclear Regulatory Commission (NRC) with technical support in identifying vital areas at nuclear power plants using a fault-tree technique. A reexamination of some system modeling assumptions is being performed for the Vital Area Analysis Program. A short description of the vital area analysis and supporting research on modeling assumptions is presented. Perceptions of program modifications based on the research are outlined, and the status of high-priority research topics is discussed.

Bott, T.F.; Thomas, W.S.

1983-01-01

419

Determining $?$ from cluster correlation function  

E-print Network

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.

A. Kashlinsky

1998-06-17

420

Determining gas-meter accuracy  

SciTech Connect

This article describes how engineers at the Metering Research Facility are helping natural-gas companies improve pipeline efficiency by evaluating and refining the instruments used for measuring and setting prices. Accurate metering of natural gas is more important than ever as deregulation subjects pipeline companies to competition. To help improve that accuracy, the Gas Research Institute (GRI) in Chicago has sponsored the Metering Research Facility (MRF) at the Southwest Research Institute (SWRI) in San Antonio, Tex. The MRF evaluates and improves the performance of orifice, turbine, diaphragm, and ultrasonic meters as well as the gas-sampling methods that pipeline companies use to measure the flow of gas and determine its price.

Valenti, M.

1997-03-01

421

Structure determination of enterovirus 71  

SciTech Connect

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.

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

2013-02-20

422

Genetic modification and genetic determinism  

PubMed Central

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

Resnik, David B; Vorhaus, Daniel B

2006-01-01

423

Liquid chromatographic determination of water  

DOEpatents

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.

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

1990-11-13

424

Shape Determination for Deformed Cavities  

SciTech Connect

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.

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

425

Calibration effects on orbit determination  

NASA Technical Reports Server (NTRS)

The effects of charged particle and tropospheric calibrations on the orbit determination (OD) process are analyzed. The calibration process consisted of correcting the Doppler observables for the media effects. Calibrated and uncalibrated Doppler data sets were used to obtain OD results for past missions as well as Mariner Mars 1971. Comparisons of these Doppler reductions show the significance of the calibrations. For the MM'71 mission, the media calibrations proved themselves effective in diminishing the overall B-plane error and reducing the Doppler residual signatures.

Madrid, G. A.; Winn, F. B.; Zielenbach, J. W.; Yip, K. B.

1974-01-01

426

Velocity determination from velocity spectra  

E-print Network

VELOCITY DETERMINATION FRON VELOCITY SPECTRA A Thesis by SUNG JIN YANG Submutted to the Graduate C:lleEe of Texas ASM University in partial fulfill sent of requirement for the degree of EASTER GF SCIENCE December 1973 Naj or Subject...: Ccophysics VELOCITY DETEPddINATION FROM VELOCITY SPECTRA A Thesis by SUNG JIN YANG Approved as to style and content by: ( Chai~ of C a0nitte ) (Read oi: Doper ent-IL irber) ( Meraber ) (i~ &r) Decen'bex' 1973 487460 ABSTRACT Velocity Determinati...

Yang, Sung Jin

2012-06-07

427

Determination of a mutational spectrum  

DOEpatents

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.

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

1991-01-01

428

Determination of a mutational spectrum  

SciTech Connect

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.

Thilly, W.G.; Keohavong, P.

1991-09-03

429

Activity determination of (59)Fe.  

PubMed

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

Kossert, Karsten; Nähle, Ole J

2014-11-01

430

Determination of Silicon in Hydrazine  

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

431

[Determination of uranium in spinach].  

PubMed

After the severe accident at the Fukushima-1 Nuclear Power Plant in March 2011, radioactive contamination of food has become a matter of serious concern in Japan. There is considerable information about radioactive iodine and cesium, but little is known about uranium contamination. We determined uranium content in spinach by the Japanese official method (Manual on Radiation Measurement of Food in Emergency Situations). In the preliminary study, we confirmed that the use of a microwave digestion system for preparing the test solution of spinach could shorten the testing time and give acceptable results. The manual recommends the use of two elements (Tl and Bi) as internal standards for measurement of uranium by ICP-MS. We found that Tl was more suitable than Bi to quantify trace amounts of uranium in spinach. However, it was necessary to determine Tl or Bi concentrations in the sample before analysis, since some samples of spinach contained significant amounts of these elements. The uranium contents of 9 spinach samples bought in April and May 2011 were less than 10 ?g/kg, which are very low compared to the provisional regulatory limit in Japan. PMID:23676689

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

2013-01-01

432

The determinants of hospital profitability.  

PubMed

Although numerous studies related to hospital costs and financial condition have been conducted, no studies have specifically attempted to identify the underlying determinants of hospital profitability. If these factors are identified, hospital executives can focus their efforts on those aspects of operations that most affect profitability, and public policymakers can gain insights into the potential effects of alternative policy decisions on hospital financial viability. Our study uses multiple regression analysis with 22 hypothesized profitability determinants as independent variables and five profitability measures as dependent variables. The data set consists of 1989 data from 169 investor-owned and private not-for-profit general acute care hospitals in the state of Florida. The results provide evidence that selected managerial and patient-mix variables are predictors of profitability. Structural factors that are beyond the control of managers (organizational and community characteristics) appear to be less important in influencing profitability. These findings may be viewed positively by hospital executives since it appears profitability is not dictated by organizational or market factors but more strongly influenced by factors that, to some extent, can be influenced by hospital policies and practices. PMID:10127295

Gapenski, L C; Vogel, W B; Langland-Orban, B

1993-01-01

433

Mars Observer orbit determination analysis  

NASA Technical Reports Server (NTRS)

Results are presented of a simulated orbit determination analysis for three phases of the Mars Observer mission (interplanetary cruise, orbit insertion, and mapping), together with a summary of orbital accuracies throughout the Mars Observer mission. The plan for achieving the navigation objectives of the Mars Observer mission is described. These objectives are to navigate the Mars Observer spacecraft to Mars and achieve accurate targeting at Mars; to propulsively maneuver the spacecraft into a 3-day period, capture orbit; to navigate the spacecraft into a 1.96-hr period low-altitude, nearly circular mapping orbit; and to maintain Mars Observer in the mapping orbit throughout the 687 days devoted for scientific data acquisition. Factors that will affect the spacecraft during each of the three phases are discussed.

Esposito, Pasquale; Roth, Duane; Demcak, Stuart

1991-01-01

434

Mars Observer orbit determination analysis  

NASA Astrophysics Data System (ADS)

Results are presented of a simulated orbit determination analysis for three phases of the Mars Observer mission (interplanetary cruise, orbit insertion, and mapping), together with a summary of orbital accuracies throughout the Mars Observer mission. The plan for achieving the navigation objectives of the Mars Observer mission is described. These objectives are to navigate the Mars Observer spacecraft to Mars and achieve accurate targeting at Mars; to propulsively maneuver the spacecraft into a 3-day period, capture orbit; to navigate the spacecraft into a 1.96-hr period low-altitude, nearly circular mapping orbit; and to maintain Mars Observer in the mapping orbit throughout the 687 days devoted for scientific data acquisition. Factors that will affect the spacecraft during each of the three phases are discussed.

Esposito, Pasquale; Roth, Duane; Demcak, Stuart

1991-10-01

435

T-Cell Lineage Determination  

PubMed Central

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

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

2010-01-01

436

Seasat. Volume 4: Attitude determination  

NASA Technical Reports Server (NTRS)

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.

Treder, A. J.

1980-01-01

437

GRO attitude control and determination  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

438

Experimental Determination of Ramsey Numbers  

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

439

Determinants of muscle carnosine content.  

PubMed

The main determinant of muscle carnosine (M-Carn) content is undoubtedly species, with, for example, aerobically trained female vegetarian athletes [with circa 13 mmol/kg dry muscle (dm)] having just 1/10th of that found in trained thoroughbred horses. Muscle fibre type is another key determinant, as type II fibres have a higher M-Carn or muscle histidine containing dipeptide (M-HCD) content than type I fibres. In vegetarians, M-Carn is limited by hepatic synthesis of ?-alanine, whereas in omnivores this is augmented by the hydrolysis of dietary supplied HCD's resulting in muscle levels two or more times higher. ?-alanine supplementation will increase M-Carn. The same increase in M-Carn occurs with administration of an equal molar quantity of carnosine as an alternative source of ?-alanine. Following the cessation of supplementation, M-Carn returns to pre-supplementation levels, with an estimated t1/2 of 5-9 weeks. Higher than normal M-Carn contents have been noted in some chronically weight-trained subjects, but it is unclear if this is due to the training per se, or secondary to changes in muscle fibre composition, an increase in ?-alanine intake or even anabolic steroid use. There is no measureable loss of M-Carn with acute exercise, although exercise-induced muscle damage may result in raised plasma concentrations in equines. Animal studies indicate effects of gender and age, but human studies lack sufficient control of the effects of diet and changes in muscle fibre composition. PMID:22327512

Harris, R C; Wise, J A; Price, K A; Kim, H J; Kim, C K; Sale, C

2012-07-01

440

77 FR 20375 - Notice of Availability of Secretarial Determination and Basis for Determination Under Section...  

Federal Register 2010, 2011, 2012, 2013

...Availability of Secretarial Determination and Basis for Determination Under Section 3116 of...availability of the Secretarial Determination and Basis for Section 3116 Determination for Closure...at the Savannah River Site (FTF 3116 Basis Document). DOE prepared and...

2012-04-04

441

Nondestructive Determination of Bond Strength  

NASA Technical Reports Server (NTRS)

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.

2000-01-01

442

Geographic Determinants of Chinese Urbanization  

NASA Astrophysics Data System (ADS)

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.

Mccord, G. C.; Christensen, P.

2011-12-01

443

Molecular Detection of Resistance Determinants  

PubMed Central

The development of new antibiotics and the emergence of novel resistance mechanisms to counteract these drugs create a dynamic and challenging task for the clinical microbiology laboratory. The goal of antimicrobial resistance testing is to provide timely therapeutic options to guide the management of infectious diseases resulting from bacterial infections. Antimicrobial susceptibility has classically been determined using a variety of in vitro methods, such as disk diffusion, broth microdilution, and automated instrument-based methods. Using these methods, the reporting of MICs and interpretations can require 24 to 96 h after a pure culture of the suspected pathogen is obtained (6). Unfortunately, results obtained after 48 h are often of little clinical value and are unlikely to alter antimicrobial therapy. The extended turnaround associated with phenotypic antimicrobial resistance testing provides an opportunity for the use of alternative technologies capable of producing more timely results. The first reports in this supplement explore the manner in which the criteria for interpreting MICs are developed and the clinical relevance of antimicrobial susceptibility testing. In this report, we present an alternative to routine susceptibility testing and examine the role of molecular susceptibility testing now and in the future.

Ledeboer, Nathan A.; Hodinka, Richard L.

2011-01-01

444

Lipid determinants of cell death.  

PubMed

Lipids produced by the epidermis serve a number of protective functions, and also act as messengers which activate plant defense responses. The fatty acid elongases which catalyze the formation of very long-chain fatty acids, may be instrumental in the remodeling of the various classes of epidermal lipids, and they also provide a means with which to further investigate the defense mechanisms. In a recent publication, we reported that the epidermal mis-expression of FATTY ACID ELONGASE1 (FAE1) in the Arabidopsis plant both increased the levels of very long-chain fatty acids in various lipid classes, and unexpectedly induced a cell-type specific cell death program in trichome cells, giving the plants a glabrous appearance. Using these plants as a model system for a fatty acid-induced cell death (lipoapoptosis), and a platform for the chemical genetic screen, we identified trichome death inhibitors in the glycerophospholipid fatty acyl remodeling pathway: phospholipase A2 inhibitors, aristolochic acid and bromoenol lactone, as well as the putative lysophospholipid acyltransferase inhibitor, clofibrate. Herein, and due to space limitations, we will briefly discuss these results and the different ways in which the appearance of increasing chain-length fatty acids is likely to regulate the cellular life-or-death switch. The death receptor hypothesis implies the existence of a bioactive lipid ligand(s), the functionality of which is determined by phosphorylation, acyl chain length and saturation. PMID:19820339

Reina-Pinto, José J; Yephremov, Alexander

2009-07-01

445

Determinants of pulmonary blood volume  

PubMed Central

Pulmonary blood volume was determined by the radiocardiographic technique in 49 patients coming to cardiac catheterization. Since this method has not been directly compared with the more commonly used double injection of dye. 25 comparisons were carried out in 13 patients of the series. Agreement was good over a range of 4.5-21.1 heart cycles since there was no statistically significant difference between transit time values measured by the two methods. The relation of pulmonary blood volume to other hemodynamic factors in these 49 patients, with and without cardiac or pulmonary disease, was evaluated by means of multiple regression analysis. The analysis carried out for mean transit time indicates that this parameter varies predominately with flow. Pulmonary blood volume, in this series of resting recumbent individuals, varies to a significant degree only with total blood volume and with pulmonary venous pressure. No parameters of vascular distensibility, such as pulmonary vascular resistance, were found to affect the volume of blood in the lungs. The fact that variations in pulmonary blood volume among the subjects could be described by a multiple regression equation linear with respect to total blood volume and pulmonary venous pressure indicates that these variations are the result of passive distention of components of the vascular bed. PMID:4902826

Lewis, Milena L.; Gnoj, Julian; Fisher, Vincent J.; Christianson, Lynn C.

1970-01-01

446

Genetic determinants of plasma triglycerides  

PubMed Central

Plasma triglyceride (TG) concentration is reemerging as an important cardiovascular disease risk factor. More complete understanding of the genes and variants that modulate plasma TG should enable development of markers for risk prediction, diagnosis, prognosis, and response to therapies and might help specify new directions for therapeutic interventions. Recent genome-wide association studies (GWAS) have identified both known and novel loci associated with plasma TG concentration. However, genetic variation at these loci explains only ?10% of overall TG variation within the population. As the GWAS approach may be reaching its limit for discovering genetic determinants of TG, alternative genetic strategies, such as rare variant sequencing studies and evaluation of animal models, may provide complementary information to flesh out knowledge of clinically and biologically important pathways in TG metabolism. Herein, we review genes recently implicated in TG metabolism and describe how some of these genes likely modulate plasma TG concentration. We also discuss lessons regarding plasma TG metabolism learned from various genomic and genetic experimental approaches. Treatment of patients with moderate to severe hypertriglyceridemia with existing therapies is often challenging; thus, gene products and pathways found in recent genetic research studies provide hope for development of more effective clinical strategies. PMID:21041806

Johansen, Christopher T.; Kathiresan, Sekar; Hegele, Robert A.

2011-01-01

447

Determinants of irritant termination behavior  

SciTech Connect

Mice will respond to escape from airborne chemical irritants. Irritant concentration is major determinant of this performance. Behavioral variables also affect both the acquisition and sensitivity of this behavior. Mice will rapidly learn to poke their nose into a conical sensor if the poke terminates the delivery of 0.1% ammonia and produces a facial shower of clean humidified air from the sensor. Without a response-contingent facial shower mice learned more slowly to escape from ammonia, and did not acquire comparable levels of performance. Subsequent access to a facial shower improved their performance within a few sessions. Discontinuing the facial shower for mice who learned the task with it resulted in a moderate disruption of performance. Requiring five responses rather than a single response for irritant termination resulted in a steeper concentration-effect curve which is more useful for the evaluation of the relative aversive potency of airborne chemical irritants. A comparison of two prototypical irritants demonstrated that the aversive concentration of ammonia at which 50% of the irritant deliveries are terminated (AC50) is 334 ppm; the AC50 for acetic acid is 43 ppm. Therefore, acetic acid is approximately eight times more aversive than ammonia.

Wood, R.W.

1981-01-01

448

Social network determinants of depression.  

PubMed

The etiology of depression has long been thought to include social environmental factors. To quantitatively explore the novel possibility of person-to-person spread and network-level determination of depressive symptoms, analyses were performed on a densely interconnected social network of 12,067 people assessed repeatedly over 32 years as part of the Framingham Heart Study. Longitudinal statistical models were used to examine whether depressive symptoms in one person were associated with similar scores in friends, co-workers, siblings, spouses and neighbors. Depressive symptoms were assessed using CES-D scores that were available for subjects in three waves measured between 1983 and 2001. Results showed both low and high CES-D scores (and classification as being depressed) in a given period were strongly correlated with such scores in one's friends and neighbors. This association extended up to three degrees of separation (to one's friends' friends' friends). Female friends appear to be especially influential in the spread of depression from one person to another. The results are robust to multiple network simulation and estimation methods, suggesting that network phenomena appear relevant to the epidemiology of depression and would benefit from further study. PMID:20231839

Rosenquist, J N; Fowler, J H; Christakis, N A

2011-03-01

449

Social network determinants of depression  

PubMed Central

The etiology of depression has long been thought to include social environmental factors. To quantitatively explore the novel possibility of person-to-person spread and network-level determination of depressive symptoms, analyses were performed on a densely interconnected social network of 12 067 people assessed repeatedly over 32 years as part of the Framingham Heart Study. Longitudinal statistical models were used to examine whether depressive symptoms in one person were associated with similar scores in friends, co-workers, siblings, spouses and neighbors. Depressive symptoms were assessed using CES-D scores that were available for subjects in three waves measured between 1983 and 2001. Results showed both low and high CES-D scores (and classification as being depressed) in a given period were strongly correlated with such scores in one's friends and neighbors. This association extended up to three degrees of separation (to one's friends’ friends’ friends). Female friends appear to be especially influential in the spread of depression from one person to another. The results are robust to multiple network simulation and estimation methods, suggesting that network phenomena appear relevant to the epidemiology of depression and would benefit from further study. PMID:20231839

Rosenquist, JN; Fowler, JH; Christakis, NA

2013-01-01

450

Extractive Spectrophotometric Determination of Ambrisentan  

PubMed Central

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

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

2013-01-01

451

Determinants of human population growth.  

PubMed Central

The 20th century has seen unprecedented growth of the human population on this planet. While at the beginning of the century the Earth had an estimated 1.6 billion inhabitants, this number grew to 6.1 billion by the end of the century, and further significant growth is a near certainty. This paper tries to summarize what factors lie behind this extraordinary expansion of the human population and what population growth we can expect for the future. It discusses the concept of demographic transition and the preconditions for a lasting secular fertility decline. Recent fertility declines in all parts of the world now make it likely that human population growth will come to an end over the course of this century, but in parts of the developing world significant population growth is still to be expected over the coming decades. The slowing of population growth through declining birth rates, together with still increasing life expectancy, will result in a strong ageing of population age structure. Finally, this paper presents a global level systematic analysis of the relationship between population density on the one hand, and growth and fertility rates on the other. This analysis indicates that in addition to the well-studied social and economic determinants, population density also presents a significant factor for the levels and trends of human birth rates. PMID:12396512

Lutz, Wolfgang; Qiang, Ren

2002-01-01

452

Ballistic projectile trajectory determining system  

DOEpatents

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.

Karr, T.J.

1997-05-20

453

Determining structure in molecular clouds  

NASA Technical Reports Server (NTRS)

We descibe an automatic, objective routine for analyzing the clumpy structure in a spectral line position-position-velocity data cube. The algorithm works by first contouring the data at a multiple of the rms noise of the observations, then searches for peaks of emission which locate the clumps, and then follows them down to lower intensities. No a proiri clump profile is assumed. By creating simulated data, we test the performance of the algorithm and show that a contour map most accurately depicts internal structure at a contouring interval equal to twice the rms noise of the map. Blending of clump emission leads to small errors in mass and size determinations and in severe cases can result in a number of clumps being misidentified as a single unit, flattening the measured clump mass spectrum. The algorithm is applied to two real data sets as an example of its use. The Rosette molecular cloud is a 'typical' star-forming cloud, but in the Maddalena molecular cloud high-mass star formation is completely absent. Comparison of the two clump lists generated by the algorithm show that on a one-to-one basis the clumps in the star-forming cloud have higher peak temperatures, higher average densities, and are more gravitationally bound than in the non-star-forming cloud. Collective properties of the clumps, such as temperature-size-line-width-mass relations appear very similar, however. Contrary to the initial results reported in a previous paper (Williams & Blitz 1993), we find that the current, more thoroughly tes ted analysis finds no significant difference in the clump mass spectrum of the two clouds.

Williams, Jonathan P.; De Geus, Eugene J.; Blitz, Leo

1994-01-01

454

Clinical determinants of PACS acceptance  

NASA Astrophysics Data System (ADS)

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.

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

1990-08-01