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1

State Diagram of Date Flesh Using Differential Scanning Calorimetry (DSC)  

Microsoft Academic Search

The state diagram of date flesh was developed by measuring its freezing points, glass transition temperatures, maximal-freeze-concentration condition ( and ), and solute melting points (or decomposition temperature) by Differential Scanning Calorimetry (DSC). The freezing curve and glass transition lines were developed using Clausius-Clapeyron equation by incorporating concept of unfrozen water, and Gordon-Taylor equation, respectively. The developed state diagram of

M. Shafiur Rahman

2004-01-01

2

Differential Scanning Calorimetry (DSC) for planetary surface exploration  

NASA Technical Reports Server (NTRS)

Differential Scanning Calorimetry (DSC) is the quantitative measurement of the enthalpic response of a material to a systematic change in temperature. In practice, the heat flow into or outward from a sample is measured as the sample is heated or cooled at a carefully controlled rate. DSC superficially resembles, but is not the same as differential thermal analysis (DTA), which is the measurement of temperature differences between a sample and reference material as the pair is heated or cooled. The fundamental properties measured by DSC are enthalpies and temperatures of phase transitions and constant-pressure heat capacities. Depending on instrument design and the nature of the sample, high-quality DSC analyses can be obtained on only a few milligrams of solid materials. DSC requires direct contact with the sample and generally degrades, if not destroys, the sample as a consequence of heating. In laboratory applications, it is common to subject the gaseous effluent from the DSC to analysis by a separate evolved-gas analyzer (EGA).

Gooding, James L.; Ming, Douglas W.

1993-01-01

3

Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) The materials characterization laboratory is equipped with a Thermogravimetric Analysis and  

E-print Network

Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) The materials Analysis and a Differential Scanning Calorimetry. The materials characterization laboratory is also equipped with a Differential Scanning Calorimetry (DSC) unit. The system includes a METTLER DSC822e model

Gelfond, Michael

4

Determination of Purity by Differential Scanning Calorimetry (DSC).  

ERIC Educational Resources Information Center

An exercise is presented which demonstrates the determination of sample purity by differential scanning calorimetry. Data and references are provided to enable the exercise to be carried out as a dry-lab experiment. (BB)

Brown, M. E.

1979-01-01

5

Characterization of Star-shaped marcomolecules with calix[8]arene core by Differential Scanning Calorimetry (DSC).  

E-print Network

??This thesis was written to analysis thermal behavior of oligomer and their star-shaped macromolecules by Differential Scanning Calorimetry (DSC) and Polarized Optical Microscope (POM) methods.… (more)

Nguyen, Huy

2012-01-01

6

Differential scanning calorimetry (DSC) analyses of superelastic and nonsuperelastic nickel-titanium orthodontic wires  

Microsoft Academic Search

The purpose of this study was to determine the transformation temperatures for the austenitic, martensitic, and rhombohedral (R) structure phases in representative as-received commercial nitinol (NiTi) orthodontic wire alloys, to reconcile discrepancies among recent publications. Specimens were examined by differential scanning calorimetry (DSC) over a temperature range from approximately ?170° C to 100° C, with a scanning rate of 10°

Thomas Gerard Bradley; William A. Brantley; Bill M. Culbertson

1996-01-01

7

The application of differential scanning calorimetry (DSC) to the study of epoxy resin curing reactions  

Microsoft Academic Search

This review is on the use of differential scanning calorimetry as a method of monitoring and investigating the kinetics of\\u000a epoxy resin curing reactions. Some instrumental and experimental aspects are discussed, including methods of analysing the\\u000a kinetic data. A brief survey is made of epoxy resin curing reactions and results of DSC studies are reviewed. These results\\u000a are concerned with

John M. Barton

8

The effective utilization of differential scanning calorimetry (DSC) to assess molded parts  

SciTech Connect

A widely accepted method for determining degree of cure of diallyl pthlalate (DAP) resin based molded parts is differential scanning calorimetry (DSC). The differential scanning calorimeter is a laboratory instrument which measures the exothermic heat of reaction as the thermosetting molding compound undergoes polymerization (cure). It is standard industry practice to utilize the data from this analysis to assign the percentage of cure for the molded part. This practice was addressed for several reasons. First, the DSC versus cure time is not a linear function. However, the usual convention specifies a linear scale for the percentage cure. This can cause concern for the customer when this calculated ''percentage cure'' is below a value that is perceived as acceptable. This perception is often based on a psychological premise as to the quality of the part as it relates to the percentage cure and not to the associated physical properties of the part. 3 refs., 3 figs., 1 tab.

Kaye, C.J.

1989-01-01

9

Determination of the heat of hydride formation/decomposition by high-pressure differential scanning calorimetry (HP-DSC).  

PubMed

Among the thermodynamic properties of novel materials for solid-state hydrogen storage, the heat of formation/decomposition of hydrides is the most important parameter to evaluate the stability of the compound and its temperature and pressure of operation. In this work, the desorption and absorption behaviors of three different classes of hydrides are investigated under different hydrogen pressures using high-pressure differential scanning calorimetry (HP-DSC). The HP-DSC technique is used to estimate the equilibrium pressures as a function of temperature, from which the heat of formation is derived. The relevance of this procedure is demonstrated for (i) magnesium-based compounds (Ni-doped MgH2), (ii) Mg-Co-based ternary hydrides (Mg-CoHx) and (iii) Alanate complex hydrides (Ti-doped NaAlH4). From these results, it can be concluded that HP-DSC is a powerful tool to obtain a good approximation of the thermodynamic properties of hydride compounds by a simple and fast study of desorption and absorption properties under different pressures. PMID:17973422

Rongeat, Carine; Llamas-Jansa, Isabel; Doppiu, Stefania; Deledda, Stefano; Borgschulte, Andreas; Schultz, Ludwig; Gutfleisch, Oliver

2007-11-22

10

Calorimetry  

NSDL National Science Digital Library

As part of a larger collection of virtual experiments, this link deals exclusively with the fundamentals of Heat Capacity. A bomb calorimeter is shown and the user is allowed to used a desired amount of materials to measure the heat capacity of: 1) ethanol; 2) copper; and 3) ammonium nitrate. Heat of neutralization reactions and combustion reactions are also explored. Nonideal loss and gain of heat during calorimetry experiments are explored by measuring the heat of solution of sulfuric acid. Strategies are also discussed for studying systems in which two chemical reactions simultaneously occur.

Blauch, David N.

11

Differential scanning calorimetry (DSC) studies on the thermal properties of peanut proteins.  

PubMed

Studies related to the functional and thermal properties of peanut proteins are limited if compared with other vegetable protein sources. The aim of this work was to study the thermal denaturation of peanut protein isolates (PPI) by DSC. The thermal profile of PPI showed two endothermic peaks (assigned to denaturation of arachin and conarachin fractions). The thermal stability of arachin and conarachin increased when water content decreased, and a critical water level was found for both fractions. The effect of protein denaturants was studied. Low contents of urea stabilized protein fractions, but lower T(d) values were found with increasing concentrations. DeltaH values of arachin were affected by urea. SDS affected DeltaH values and thermal stability of conarachin; the arachin fraction showed higher resistance to SDS-induced denaturation. DTT addition did not affect conarachin stability, although enthalpy values decreased significantly. On the other hand, arachin was greatly affected by DTT. In summary, thermal denaturation parameters of PPI were sensitive to water content, indicating that polar groups of arachin and conarachin contribute to structure stabilization. Urea addition mainly affected the structure of the arachin fraction, which was attributed to its higher surface hydrophobicity. Results obtained from SDS and DTT suggest that hydrophobic interactions and disulfide bonds play an important role in structure maintenance of arachin and conarachin. PMID:20222749

Colombo, Andrés; Ribotta, Pablo Daniel; León, Alberto Edel

2010-04-14

12

Estimation of the time to maximum rate using dynamic DSC experiments  

Microsoft Academic Search

The probability of thermal risk may be described by the time to maximum rate under adiabatic conditions (TMRad). In this paper a screening method based on dynamic differential scanning calorimetry (DSC) measurements was studied in order to show that, when using the TMRad criterion, no process would be assessed as safe when it could, in fact, be critical. The method

Andreas Keller; Daniel Stark; Hans Fierz; Elmar Heinzle; Konrad Hungerbühler

1997-01-01

13

Solution Calorimetry Experiments for Physical Chemistry.  

ERIC Educational Resources Information Center

Presents two experiments: the first one measures the heat of an exothermic reaction by the reduction of permanganate by the ferris ion; the second one measures the heat of an endothermic process, the mixing of ethanol and cyclohexane. Lists tables to aid in the use of the solution calorimeter. (MVL)

Raizen, Deborah A.; And Others

1988-01-01

14

Differential Scanning Calorimetry Techniques: Applications in Biology and Nanoscience  

PubMed Central

This paper reviews the best-known differential scanning calorimetries (DSCs), such as conventional DSC, microelectromechanical systems-DSC, infrared-heated DSC, modulated-temperature DSC, gas flow-modulated DSC, parallel-nano DSC, pressure perturbation calorimetry, self-reference DSC, and high-performance DSC. Also, we describe here the most extensive applications of DSC in biology and nanoscience. PMID:21119929

Gill, Pooria; Moghadam, Tahereh Tohidi; Ranjbar, Bijan

2010-01-01

15

Correlating DSC and X-Ray Measurements Of Crystallinity  

NASA Technical Reports Server (NTRS)

Experiment demonstrated approximate linear correlation between degree of crystallinity of multiphase polymer (as calculated from x-ray diffraction measurements) and heat of fusion of polymer (as calculated from differential scanning calorimetry (DSC) measurements). Correlation basis of simple new technique for estimating degree of crystallinity of specimens of polymer from DSC measurements alone.

Yen, Shiao-Ping S.; Lowry, Lynn E.; Bankston, Clyde P.

1991-01-01

16

Calorimetry for ILC Experiments: CALICE Collaboration R&D  

E-print Network

The CALICE Collaboration is carrying out research and development into calorimetry for a detector at the International Linear Collider (ILC). CALICE is investigating a range of technologies for both electromagnetic and hadronic calorimetry. An overview of the prototypes and selected test-beam results are presented.

D. S. Bailey; for the CALICE Collaboration

2008-10-20

17

Bomb Calorimetry  

NSDL National Science Digital Library

This site provides an animated overview (and actual performance) of a bomb calorimetry experiment. It would serve as a good introduction or review for students about to perform this experiment in the laboratory.

18

Laboratory Annealing Experiments Of Refractory Silicate Grain Analogs Using Differential Scanning Calorimetry  

NASA Technical Reports Server (NTRS)

Exothermic reactions during the annealing of laboratory synthesized amorphous magnesium-bearing silicate particles used as grain analogs of cosmic dust were detected by differential scanning calorimetry (DSC) in air. With infrared spectroscopy and transmission electron microscopy, we show that cosmic dust could possibly undergo fusion to larger particles, with oxidation of magnesium silicide and crystallization of forsterite as exothermic reactions in the early solar system. The reactions begin at approximately 425, approximately 625, and approximately 1000 K, respectively, and the reaction energies (enthalpies) are at least 727, 4151, and 160.22 J per gram, respectively. During the crystallization of forsterite particles, the spectral evolution of the 10 micrometer feature from amorphous to crystalline was observed to begin at lower temperature than the crystallization temperature of 1003 K. During spectral evolution at lower temperature, nucleation and/or the formation of nanocrystallites of forsterite at the surface of the grain analogs was observed.

Kimura, Yuki; Nuth, Joseph A., III; Tsukamota, Katsuo; Kaito, Chihiro

2010-01-01

19

The measurement of the crystallinity of polymers by DSC  

Microsoft Academic Search

The procedures adopted and the inherent assumptions made in the measurement of crystallinity of polymers by differential scanning calorimetry (DSC) are reviewed. The inherent problem in all DSC measurements is concurrent recrystallisation and melting of the polymer sample on heating to the melting point and the variation of the enthalpies of crystallisation and melting, heat capacities and degree of crystallinity

Y. Kong; J. N. Hay

2002-01-01

20

A Differential Scanning Calorimetry Method for Construction of Continuous Cooling Transformation Diagram of Blast Furnace Slag  

NASA Astrophysics Data System (ADS)

The continuous cooling crystallization of a blast furnace slag was studied by the application of the differential scanning calorimetry (DSC) method. A kinetic model describing the correlation between the evolution of the degree of crystallization with time was obtained. Bulk cooling experiments of the molten slag coupled with numerical simulation of heat transfer were conducted to validate the results of the DSC methods. The degrees of crystallization of the samples from the bulk cooling experiments were estimated by means of the X-ray diffraction (XRD) and the DSC method. It was found that the results from the DSC cooling and bulk cooling experiments are in good agreement. The continuous cooling transformation (CCT) diagram of the blast furnace slag was constructed according to crystallization kinetic model and experimental data. The obtained CCT diagram characterizes with two crystallization noses at different temperature ranges.

Gan, Lei; Zhang, Chunxia; Shangguan, Fangqin; Li, Xiuping

2012-06-01

21

DSC AND X-RAY DIFFRACTION INVESTIGATIONS OF PHASE TRANSITIONS IN HxBABA AND NBABA  

E-print Network

DSC AND X-RAY DIFFRACTION INVESTIGATIONS OF PHASE TRANSITIONS IN HxBABA AND NBABA K. USHA DENIZ, A studied by DSC in the temperature range, -- 100 °C to 300 °C. A scheme of tran- sitions has been proposed Scanning Calorimetry (DSC). Several hitherto un- known phases have been found to occur above room

Paris-Sud XI, Université de

22

Constraints on the Interactions between Dark Matter and Baryons from the X-ray Quantum Calorimetry Experiment  

E-print Network

Although the rocket-based X-ray Quantum Calorimetry (XQC) experiment was designed for X-ray spectroscopy, the minimal shielding of its calorimeters, its low atmospheric overburden, and its low-threshold detectors make it among the most sensitive instruments for detecting or constraining strong interactions between dark matter particles and baryons. We use Monte Carlo simulations to obtain the precise limits the XQC experiment places on spin-independent interactions between dark matter and baryons, improving upon earlier analytical estimates. We find that the XQC experiment rules out a wide range of nucleon-scattering cross sections centered around one barn for dark matter particles with masses between 0.01 and 10^5 GeV. Our analysis also provides new constraints on cases where only a fraction of the dark matter strongly interacts with baryons.

Adrienne L. Erickcek; Paul J. Steinhardt; Dan McCammon; Patrick C. McGuire

2007-04-05

23

Constraints on the interactions between dark matter and baryons from the x-ray quantum calorimetry experiment  

NASA Astrophysics Data System (ADS)

Although the rocket-based x-ray quantum calorimetry (XQC) experiment was designed for x-ray spectroscopy, the minimal shielding of its calorimeters, its low atmospheric overburden, and its low-threshold detectors make it among the most sensitive instruments for detecting or constraining strong interactions between dark matter particles and baryons. We use Monte Carlo simulations to obtain the precise limits the XQC experiment places on spin-independent interactions between dark matter and baryons, improving upon earlier analytical estimates. We find that the XQC experiment rules out a wide range of nucleon-scattering cross sections centered around 1 b for dark matter particles with masses between 0.01 and 105GeV. Our analysis also provides new constraints on cases where only a fraction of the dark matter strongly interacts with baryons.

Erickcek, Adrienne L.; Steinhardt, Paul J.; McCammon, Dan; McGuire, Patrick C.

2007-08-01

24

Neutron monitoring and electrode calorimetry experiments in the HIP-1 Hot Ion Plasma  

NASA Technical Reports Server (NTRS)

Results are presented for two diagnostic procedures on HIP-1: neutron diagnostics to determine where neutrons originated within the plasma discharge chamber and electrode calorimetry to measure the steady-state power absorbed by the two anodes and cathodes. Results are also reported for a hot-ion plasma formed with a continuous-cathode rod, one that spans the full length of the test section, in place of the two hollow cathodes. The outboard neutron source strength increased relative to that at the midplane when (1) the cathode tips were moved farther outboard, (2) the anode diameters were increased, and (3) one of the anodes was removed. The distribution of neutron sources within the plasma discharge chamber was insensitive to the division of current between the two cathodes. For the continuous cathode, increasing the discharge current increased the midplane neutron source strength relative to the outboard source strength. Each cathode absorbed from 12 to 15 percent of the input power regardless of the division of current between the cathodes. The anodes absorbed from 20 to 40 percent of the input power. The division of power absorption between the anodes varied with plasma operating conditions and electrode placement.

Reinmann, J. J.; Layman, R. W.

1977-01-01

25

Antioxidant activity of p-phenylenediamines studied by DSC  

Microsoft Academic Search

The antioxidant activity of six N,N?-substituted p-phenylenediamines in polyisoprene rubber matrix has been studied by differential scanning calorimetry (DSC) under non-isothermal conditions. A method for obtaining the parameters from non-isothermal DSC measurements, based on the dependence of the onset temperature of the oxidation peak on heating rate, is presented. The parameters of an Arrhenius-like equation describing the temperature dependence of

Z. Cibulková; P. Šimon; P. Lehocký; J. Balko

2005-01-01

26

J. MACROMOL. SCI.--PHYSICS, B40(3&4), 517527 (2001) FTIR AND DSC STUDIES OF MECHANICALLY  

E-print Network

J. MACROMOL. SCI.--PHYSICS, B40(3&4), 517­527 (2001) FTIR AND DSC STUDIES OF MECHANICALLY DEFORMED) spectroscopy and differential scanning calorimetry (DSC). The main goal of this study was to improve spectroscopy was used to examine the structural variations as a function of strain. DSC data allowed

27

Quantum Calorimetry  

NASA Technical Reports Server (NTRS)

Your opponent's serve was almost perfect, but you vigorously returned it beyond his outstretched racquet to win the point. Now the tennis ball sits wedged in the chain-link fence around the court. What happened to the ball's kinetic energy? It has gone to heat the fence, of course, and you realize that if the fence were quite colder, you might be able to measure that heat and determine just how energetic your swing really was. Calorimetry has been a standard measurement technique since James Joule and Julius von Mayer independently concluded, about 150 years ago, that heat is a form of energy. But only in the past 15 years or so has calorimetry been applied, at millikelvin temperatures, to the measurement of the energy of individual photons and particles with exquisite sensitivity. In this article, we have tried to show that continuing research in low-temperature physics leads to a greater understanding of high-temperature astrophysics. Adaptations of the resulting spectrometers will be useful tool for fields of research beyond astrophysics.

Stahle, Caroline Kilbourne; McCammon, Dan; Irwin, Kent D.

1999-01-01

28

DSC and NMR relaxation studies of starch–water interactions during gelatinization  

Microsoft Academic Search

The interactions between water and starch during gelatinization as affected by water content, maximum heating temperature and amylopectin crystallinity pattern were investigated by Differential Scanning Calorimetry (DSC) and 1H NMR relaxation. DSC was used to measure additional unfrozen water (AUW) arising from gelatinization, reflecting enhanced water–starch interactions, and enthalpy of gelatinization (?Hgel) of waxy corn, normal corn, potato and pea

Kanitha Tananuwong; David S. Reid

2004-01-01

29

Sublimation enthalpies at 298.15 K using correlation gas chromatography and differential scanning calorimetry measurements  

E-print Network

calorimetry measurements James Chickos* , Donald Hesse, Sarah Hosseini, Gary Nichols, Paul Webb Department vaporization enthalpies at 298.15 K, and differential scanning calorimetry (DSC) to measure fusion enthalpies and torsion effusion, head-space ana- lysis and calorimetry [2]. Many of these techniques require both

Chickos, James S.

30

Calorimetry Electronics  

E-print Network

Operations during the HL-LHC era will impose challenges on the calorimeter electronics both for the main readout and the trigger systems. Aging, radiation tolerance limits and new requirements from the trigger result in the need for substantial upgrades of the calorimeter electronics. We review the evolution of the readout architecture, the strategies and the technical developments in the front-end and back-end electronics as pursued by the calorimeter groups in the four LHC experiments, both emphasizing common aspects as well as pointing out issues specific to a given experiment.

Straessner, A; The ATLAS collaboration

2013-01-01

31

Comparisonof different -nucleators for isotactic polypropylene, characterisation byDSC and temperature-modulated DSC (TMDSC) measurements  

Microsoft Academic Search

The nucleating efficiency and selectivity of different\\u000a ?-nucleating agents was characterised and compared by differential scanning\\u000a calorimetry, (DSC) and temperature-modulated DSC (TMDSC). The nucleating agents\\u000a were the calcium salts of pimelic and suberic acid (Ca-pim and Ca-sub), linear trans-?-quinacridone (LTQ), a commercial nucleator\\u000a NJ Star (NJS) and an experimental product (CGX-220). The efficiency and the\\u000a selectivity of Ca-sub and Ca-pim

A. Menyhárd; J. Varga; G. Molnár

2006-01-01

32

Probing Glass Transition of Ultrathin Polymer Films at a Time Scale of Seconds Using Fast Differential Scanning Calorimetry  

E-print Network

Differential Scanning Calorimetry Mikhail Yu. Efremov, Eric A. Olson, Ming Zhang, Zishu Zhang, and Leslie H Received April 9, 2004 ABSTRACT: Ultrasensitive, thin-film, differential scanning calorimetry is used, the standard technique for glass-transition research in bulk materialssdifferential scanning calorimetry (DSC

Allen, Leslie H.

33

Eric J. Hall, DSc David J. Brenner, DSc  

E-print Network

and radiation therapists in this cohort, their risk of dying from any cause (from 1962 to 1992) was 1.03 (95% CIEric J. Hall, DSc David J. Brenner, DSc Index terms: Opinions Radiations, exposure to patients 1920) and is statistically significant. Hence, the claim that low doses of radiation increase longevity

Brenner, David Jonathan

34

PURITY AND HEAT OF FUSION DATA FOR ENVIRONMENTAL STANDARDS AS DETERMINED BY DIFFERENTIAL SCANNING CALORIMETRY  

EPA Science Inventory

Differential scanning calorimetry (DSC) has been applied to 273 environmental standards, including pesticides, herbicides and related compounds. embers of the following chemical classes were analyzed: rganophosphorus, organochlorine, phenol, triazine, uracil, phenoxy acid, urea, ...

35

Determination of the solubility of crystalline low molar mass compounds in polymers by differential scanning calorimetry.  

PubMed

A mathematical equation has been derived to calculate the liquidus for a binary system consisting of an amorphous polymer and a crystalline low molar mass compound. The experimental input to this equation is an interaction enthalpy, which is derived from the variation of the melting enthalpy with composition in differential scanning calorimetry (DSC) experiments. The predictive power of the equation has been tested with mixtures of acetylsalicylic acid, carbamazepine, or intraconazole with poly(ethylene glycol) as well as mixtures of carbamazepine with poly(acrylic acid), poly(hydroxystyrene), or poly(vinylpyrrolidone). It has been confirmed that the evaluation of the melting enthalpy in DSC is a suitable method to identify the preferred solute-polymer combinations for thermodynamically stable molecular dispersions. PMID:24723307

Rager, Timo

2014-06-01

36

Kinetic analysis by DSC of the cationic curing of mixtures of DGEBA and 6,6-dimethyl (4,8-dioxaspiro[2.5]octane-5,7-dione)  

Microsoft Academic Search

The kinetics of the thermal cationic cure reaction of mixtures in different proportions of diglycidylether of bisphenol A (DGEBA) with 6,6-dimethyl (4,8-dioxaspiro[2.5]octane-5,7-dione) (MCP) initiated by ytterbium or lanthanum triflates or using a conventional initiator, BF3·MEA was investigated. The non-isothermal differential scanning calorimetry (DSC) experiments at a controlled heating rate was used for obtaining the kinetic parameters of the reactive systems.

Lidia González; Xavier Ramis; Josep Maria Salla; Ana Mantecón; Angels Serra

2007-01-01

37

Curing kinetics of phase separating thermosets studied by DSC, TMDSC and dielectric relaxation spectroscopy  

Microsoft Academic Search

Differential scanning calorimetry (DSC), temperature-modulated DSC (TMDSC) and dielectric relaxation spectroscopy have been performed during isothermal curing of an epoxy network (diglycidylether of bisphenol A cross-linked with diaminodiphenyl methane) and of thermoplast modified epoxy resins (“semi-interpenetrating polymer networks”) consisting of the epoxy network component and different amounts (10 and 20wt%) of a linear high Tg-polymer (polyethersulfone). During reaction the homogeneous

I. Alig; W. Jenninger; J. E. K. Schawe

1999-01-01

38

Dual-readout Calorimetry  

E-print Network

The RD52 Project at CERN is a pure instrumentation experiment whose goal is to understand the fundamental limitations to hadronic energy resolution, and other aspects of energy measurement, in high energy calorimeters. We have found that dual-readout calorimetry provides heretofore unprecedented information event-by-event for energy resolution, linearity of response, ease and robustness of calibration, fidelity of data, and particle identification, including energy lost to binding energy in nuclear break-up. We believe that hadronic energy resolutions of {\\sigma}/E $\\approx$ 1 - 2% are within reach for dual-readout calorimeters, enabling for the first time comparable measurement preci- sions on electrons, photons, muons, and quarks (jets). We briefly describe our current progress and near-term future plans. Complete information on all aspects of our work is available at the RD52 website http://highenergy.phys.ttu.edu/dream/.

N. Akchurin; F. Bedeschi; A. Cardini; M. Cascella; F. Cei; D. De Pedis; S. Fracchia; S. Franchino; M. Fraternali; G. Gaudio; P. Genova; J. Hauptman; L. La Rotonda; S. Lee; M. Livan; E. Meoni; A. Moggi; D. Pinci; A. Policicchio; J. G. Saraiva; A. Sill; T. Venturelli; R. Wigmans

2013-07-21

39

A Comparison Study of Portland Cement Hydration Kinetics as Measured by Chemical Shrinkage and Isothermal Calorimetry  

E-print Network

and Isothermal Calorimetry Xueyu Panga *, Dale P. Bentzb , Christian Meyerc , Gary P. Funkhousera , Robert Darbea methods of evaluating cement hydration kinetics, namely chemical shrinkage and isothermal calorimetry in the experiments. Keywords: Cement hydration; chemical shrinkage; heat of hydration; isothermal calorimetry

Bentz, Dale P.

40

Learning about epoxy cure mechanisms from isoconversional analysis of DSC data  

Microsoft Academic Search

Model-free isoconversional methods can be effectively applied to isothermal and non-isothermal differential scanning calorimetry (DSC) data on epoxy cures. These methods yield a dependence of the effective activation energy on the extent of cure. Analysis of this dependence allows for untangling complex cure processes that may include different chemical reactions or a chemical reaction complicated by a mass transfer processes

Nicolas Sbirrazzuoli; Sergey Vyazovkin

2002-01-01

41

Cure kinetics of epoxy resins studied by non-isothermal DSC data  

Microsoft Academic Search

The curing kinetics of diglycidyl ether of bisphenol A (DGEBA) and diglycidyl ether of hydroquinone (DGEHQ) epoxy resins in presence of diglycidyl aniline as a reactive diluent and triethylenetetramine (TETA) as the curing agent was studied by non-isothermal differential scanning calorimetry (DSC) technique at different heating rates. The kinetic parameters of the curing process were determined by isoconversional method given

D Ro?u; C. N Ca?caval; F Musta; C Ciobanu

2002-01-01

42

Curing of a thermosetting powder coating by means of DMTA, TMA and DSC  

Microsoft Academic Search

The curing of a thermosetting powder coating made up of carboxyl-terminated polyester and triglycidylisocyanurate (TGIC) was studied by means of dynamic mechanical thermal analysis (DMTA), thermal mechanical analysis (TMA) and differential scanning calorimetry (DSC). On the basis of isothermal curing of the coating on different supports with DMTA and TMA, we determine the degree of mechanical curing. The degree of

X Ramis; A Cadenato; J. M Morancho; J. M Salla

2003-01-01

43

Nucleic acid-lipid membrane interactions studied by DSC  

PubMed Central

The interactions of nucleic acids with lipid membranes are of great importance for biological mechanisms as well as for biotechnological applications in gene delivery and drug carriers. The optimization of liposomal vectors for clinical use is absolutely dependent upon the formation mechanisms, the morphology, and the molecular organization of the lipoplexes, that is, the complexes of lipid membranes with DNA. Differential scanning calorimetry (DSC) has emerged as an efficient and relatively easy-to-operate experimental technique that can straightforwardly provide data related to the thermodynamics and the kinetics of the DNA—lipid complexation and especially to the lipid organization and phase transitions within the membrane. In this review, we summarize DSC studies considering nucleic acid—membrane systems, accentuating DSC capabilities, and data analysis. Published work involving cationic, anionic, and zwitterionic lipids as well as lipid mixtures interacting with RNA and DNA of different sizes and conformations are included. It is shown that despite limitations, issues such as DNA- or RNA-induced phase separation and microdomain lipid segregation, liposomal aggregation and fusion, alterations of the lipid long-range molecular order, as well as membrane-induced structural changes of the nucleic acids can be efficiently treated by systematic high-sensitivity DSC studies. PMID:21430956

Giatrellis, Sarantis; Nounesis, George

2011-01-01

44

Thermal degradation of a composite solid propellant examined by DSC  

Microsoft Academic Search

The thermal decomposition of ammonium perchlorate (AP)\\/hydroxyl-terminated-polybutadiene (HTPB), the AP\\/HTPB solid propellant,\\u000a was studied at different heating rates in dynamic nitrogen atmosphere. The exothermic reaction kinetics was studied by differential\\u000a scanning calorimetry (DSC) in non-isothermal conditions. The Arrhenius parameters were estimated according to the Ozawa method.\\u000a The calculated activation energy was 134.5 kJ mol-1, the pre-exponential factor, A, was 2.04×1010

J. A. F. F. Rocco; J. E. S. Lima; A. G. Frutuoso; K. Iha; M. Ionashiro; J. R. Matos; M. E. V. Suárez-Iha

2004-01-01

45

Thermalphenomena studies for dicumyl peroxide at various concentrations by DSC  

Microsoft Academic Search

Information\\u000a about the kinetics and thermal decomposition of dicumyl peroxide (DCPO) is\\u000a required for safety concerns, due to its wide applications and accident cases.\\u000a To understand the inherent hazards during DCPO manufacturing, we selected\\u000a various concentrations in different stages and analyzed them by differential\\u000a scanning calorimetry (DSC). We evaluated thermokinetic parameters to set up\\u000a a simple, but comprehensive kinetic model,

K. W. Wu; H Y Hou; C M Shu

2006-01-01

46

Thermal hazard studies for dicumyl peroxide by DSC and TAM  

Microsoft Academic Search

A differential\\u000a scanning calorimetry (DSC) and thermal activity monitor (TAM) were used to\\u000a study the thermo-kinetic parameters for dicumyl peroxide (DCPO) at various\\u000a concentrations. The potential thermal hazards of intermediates and end products\\u000a whose concentrations were at approximately 50, 70, 94 and 99.3 mass%, respectively,\\u000a in the process of operating DCPO were investigated. Thermoanalytical curves\\u000a indicate that the average heat

H. Y. Hou; T. S. Liao; Y S Duh; C M Shu

2006-01-01

47

Liquid scintillator sampling calorimetry  

E-print Network

LIQUID SCINTILLATOR SAMPLING CALORIMETRY A Thesis by R. GREG DUDGEON Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1994 Major... Subject: Physics LIQUID SCINTILLATOR SAMPLING CALORIMETRY A Thesis by R. GREG DUDGEON Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved...

Dudgeon, R. Greg

2012-06-07

48

Quartz fiber calorimetry and calorimeters  

E-print Network

Quartz fiber calorimetry is a technique the signal generation mechanism of which is based on the Cherenkov effect. In this article we try to give a comprehensive overview of the subject. We start with a general introduction to calorimetry where the basic elements that characterize the development of electromagnetic and hadronic showers are discussed. Then we describe in detail the operation principle and the properties of calorimeters equipped with quartz fibers. The main advantages of this type of calorimeters are the radiation hardness, the fast response and the compact detector dimensions, features that derive from the quartz material and the specific mechanism of operation. A section is devoted to presenting the quartz fiber calorimeters that have been built or planned to in various experiments to operate as centrality detectors, trigger detectors, luminosity monitors or general purpose very forward calorimeters.

G. Mavromanolakis

2004-12-20

49

Calorimetry for the SSC  

SciTech Connect

The activities related to calorimetry at Snowmass took place in three main areas. These were: (1) The performance criteria for SSC calorimetry, including the requirements on hermeticity, shower containment, segmentation and time resolution. The use of calorimetric means of particle identification was studied. (2) The study of triggering methods using calorimeter energy, angle and timing information. (3) A review of a wide variety of calorimeter materials for absorber and sampling, as well as several means of obtaining the readout of the energy deposits. 48 references, 10 figures, 1 table.

Gordon, H.A.; Grannis, P.D.

1984-01-01

50

ANALYSIS OF A HEAT-FLUX DIFFERENTIAL SCANNING CALORIMETRY INSTRUMENTS  

SciTech Connect

Differential Scanning Calorimetry (DSC) measurements are used to estimate the fractional latent heat release during phase changes. There are temperature lags inherent to the instruments due to the temperature measurement at a different location than that of the sample and reference materials. Recently, Dong and Hunt[1] showed that significant improvement in estimating the fractional latent heat can be obtained when detailed simulations of the heat transfer within the instrument are performed. The Netzsch DSC 404C instrument, with a high accuracy heat capacity sensor, is considered in this study. This instrument had a different configuration than that studied by Dong and Hunt[1]. The applicability of Dong and Hunt's approach to this instrument is investigated. It was found that the DSC instrument could be described by numerous parameters but that model parameters were difficult to estimate. Numerical simulation results are presented and compared with experimental results for the fractional latent heat of a commercial A356 aluminum alloy.

Sabau, Adrian S [ORNL; Porter, Wallace D [ORNL

2007-01-01

51

Measurement of protein denaturation in human synovial fluid and its analogs using differential scanning calorimetry  

Microsoft Academic Search

Differential scanning calorimetry (DSC) was used to evaluate the thermal transitions associated with protein constituents\\u000a of synovial fluid samples from three individuals with osteoarthritis. Analysis of the multi-component DSC curves revealed\\u000a that major endothermic transitions of synovial fluid occur between 60 and 80 °C and can be resolved into three peaks, likely\\u000a due to the unfolding of human serum albumin and

Lee-Ann K. BriereJan-M; Jan-M. Brandt; John B. Medley

2010-01-01

52

Scintillator materials for calorimetry  

SciTech Connect

Requirements for fast, dense scintillator materials for calorimetry in high energy physics and approaches to satisfying these requirements are reviewed with respect to possible hosts and luminescent species. Special attention is given to cerium-activated crystals, core-valence luminescence, and glass scintillators. The present state of the art, limitations, and suggestions for possible new scintillator materials are presented.

Weber, M.J. [Lawrence Berkeley Lab., CA (United States). Life Sciences Div.

1994-09-01

53

Differential scanning calorimetry study of glycerinated rabbit psoas muscle fibres in intermediate state of ATP hydrolysis  

PubMed Central

Background Thermal denaturation experiments were extended to study the thermal behaviour of the main motor proteins (actin and myosin) in their native environment in striated muscle fibres. The interaction of actin with myosin in the highly organized muscle structure is affected by internal forces; therefore their altered conformation and interaction may differ from those obtained in solution. The energetics of long functioning intermediate states of ATP hydrolysis cycle was studied in muscle fibres by differential scanning calorimetry (DSC). Results SETARAM Micro DSC-II was used to monitor the thermal denaturation of the fibre system in rigor and in the presence of nucleotide and nucleotide analogues. The AM.ADP.Pi state of the ATP hydrolysis cycle has a very short lifetime therefore, we mimicked the different intermediate states with AMP.PNP and/or inorganic phosphate analogues Vi and AlF4 or BeFx. Studying glycerol-extracted muscle fibres from the rabbit psoas muscle by DSC, three characteristic thermal transitions were detected in rigor. The thermal transitions can be assigned to myosin heads, myosin rods and actin with transition temperatures (Tm) of 52.9 ± 0.7°C, 57.9 ± 0.7°C, 63.7 ± 1.0°C. In different intermediate states of the ATP hydrolysis mimicked by nucleotide analogues a fourth thermal transition was also detected which is very likely connected with nucleotide binding domain of myosin and/or actin filaments. This transition temperature Tm4 depended on the mimicked intermediate states, and varied in the range of 66°C – 77°C. Conclusion According to DSC measurements, strongly and weakly binding states of myosin to actin were significantly different. In the presence of ADP only a moderate change of the DSC pattern was detected in comparison with rigor, whereas in ADP.Pi state trapped by Vi, AlF4 or BeFx a remarkable stabilization was detected on the myosin head and actin filament which is reflected in a 3.0 – 10.0°C shift in Tm to higher temperature. A similar effect was observed in the case of the nonhydrolyzable AMP.PNP analogue. Differential DSC measurements suggest that stabilization actin structure in the intermediate states of ATP hydrolysis may play an additional role in actin-myosin interaction. PMID:17588264

Dergez, Timea; L?rinczy, Dénes; Könczöl, Franciska; Farkas, Nelli; Belagyi, Joseph

2007-01-01

54

Differential scanning calorimetry and fluorescence study of lactoperoxidase as a function of guanidinium-HCl, urea, and pH.  

PubMed

The stability of bovine lactoperoxidase to denaturation by guanidinium-HCl, urea, or high temperature was examined by differential scanning calorimetry (DSC) and tryptophan fluorescence. The calorimetric scans were observed to be dependent on the heating scan rate, indicating that lactoperoxidase stability at temperatures near Tm is controlled by kinetics. The values for the thermal transition, Tm, at slow heating scan rate were 66.8, 61.1, and 47.2 degrees C in the presence of 0.5, 1, and 2 M guanidinium-HCl, respectively. The extrapolated value for Tm in the absence of guanidinium-HCl is 73.7 degrees C, compared with 70.2 degrees C obtained by experiment; a lower experimental value without a denaturant is consistent with distortion of the thermal profile due to aggregation or other irreversible phenomenon. Values for the heat capacity, Cp, at Tm and Ea for the thermal transition decrease under conditions where Tm is lowered. At a given concentration, urea is less effective than guanidinium-HCl in reducing Tm, but urea reduces Cp relatively more. Both fluorescence and DSC indicate that thermally denatured protein is not random coil. A change in fluorescence around 35 degrees C, which was previously reported for EPR and CD measurements (Boscolo et al. Biochim. Biophys. Acta 1774 (2007) 1164-1172), is not seen by calorimetry, suggesting that a local and not a global change in protein conformation produces this fluorescence change. PMID:20298816

Zelent, Bogumil; Sharp, Kim A; Vanderkooi, Jane M

2010-07-01

55

Differential scanning calorimetry: An invaluable tool for a detailed thermodynamic characterization of macromolecules and their interactions  

PubMed Central

Differential Scanning Calorimetry (DSC) is a highly sensitive technique to study the thermotropic properties of many different biological macromolecules and extracts. Since its early development, DSC has been applied to the pharmaceutical field with excipient studies and DNA drugs. In recent times, more attention has been applied to lipid-based drug delivery systems and drug interactions with biomimetic membranes. Highly reproducible phase transitions have been used to determine values, such as, the type of binding interaction, purity, stability, and release from a drug delivery mechanism. This review focuses on the use of DSC for biochemical and pharmaceutical applications. PMID:21430954

Chiu, Michael H.; Prenner, Elmar J.

2011-01-01

56

Extruded scintillator for the Calorimetry applications  

SciTech Connect

An extrusion line has been installed and successfully operated at FNAL (Fermi National Accelerator Laboratory) in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new Facility will serve to further develop and improve extruded plastic scintillator. Recently progress has been made in producing co-extruded plastic scintillator, thus increasing the potential HEP applications of this Facility. The current R and D work with extruded and co-extruded plastic scintillator for a potential ALICE upgrade, the ILC calorimetry program and the MINERvA experiment show the attractiveness of the chosen strategy for future experiments and calorimetry. We extensively discuss extruded and co-extruded plastic scintillator in calorimetry in synergy with new Solid State Photomultipliers. The characteristics of extruded and co-extruded plastic scintillator will be presented here as well as results with non-traditional photo read-out.

Dyshkant, A.; Rykalin, V.; Pla-Dalmau, A.; Beznosko, D. [Northern Illinois Center for Accelerator and Detector Development (NICADD), Northern Illinois University, DeKalb, IL 60115 (United States); Fermi Nationa Acceleratorl Laboratory, Batavia, IL 60510 (United States); State University of New York at Stony Brook, Stony Brook, NY 11790 (United States)

2006-10-27

57

Applications of high pressure differential scanning calorimetry to aviation fuel thermal stability research  

NASA Technical Reports Server (NTRS)

High pressure differential scanning calorimetry (DSC) was studied as an alternate method for performing high temperature fuel thermal stability research. The DSC was used to measure the heat of reaction versus temperature of a fuel sample heated at a programmed rate in an oxygen pressurized cell. Pure hydrocarbons and model fuels were studied using typical DSC operating conditions of 600 psig of oxygen and a temperature range from ambient to 500 C. The DSC oxidation onset temperature was determined and was used to rate the fuels on thermal stability. Kinetic rate constants were determined for the global initial oxidation reaction. Fuel deposit formation is measured, and the high temperature volatility of some tetralin deposits is studied by thermogravimetric analysis. Gas chromatography and mass spectrometry are used to study the chemical composition of some DSC stressed fuels.

Neveu, M. C.; Stocker, D. P.

1985-01-01

58

Transformationof dynamic DSC results into isothermal data for the curing kinetics studyof the resol resins  

Microsoft Academic Search

Kinetics of thermosetting polymers curing is difficult to study by isothermal\\u000a methods based on the differential scanning calorimetry (DSC) technique. The\\u000a difficulty is due to the low sensitivity of the equipment for total reaction\\u000a heat measurements during high temperature process. The aim of this paper is\\u000a to display the equivalence between a dynamic model, the Ozawa method, and\\u000a an isothermal

M. V. Alonso; M. Oliet; J. García; F. Rodríguez; J. Echeverría

2006-01-01

59

Curing Kinetics Of Tannin-Phenol-Formal- dehyde Adhesives As Determined By DSC  

Microsoft Academic Search

Differential scanning calorimetry (DSC) was used to compare the thermal curing of two adhesives suitable for using in the\\u000a manufacture of exterior-grade plywood boards: a commercial phenol-formaldehyde (PF) resin, and a tannin-phenol-formaldehyde\\u000a (TPF) resin developed in our laboratory. The experimental curves were well simulated by means of the Model Free Kinetics isoconversional\\u000a method incorporated in the Mettler-Toledo STARe software package.

G. Vázquez; J. González-Álvarez; F. López-Suevos; S. Freire; G. Antorrena

2002-01-01

60

Effect of Oxygen Free Radicals on Myosin in Muscle Fibres. A DSC and EPR study  

Microsoft Academic Search

Differential scanning calorimetry (DSC) and electron paramagnetic resonance spectroscopy (EPR, both conventional and saturation\\u000a transfer EPR) were used to study the motional dynamics and segmental flexibility of myosin in muscle fibres in the presence\\u000a of free radical generating system.\\u000a \\u000a Muscle fibre bundles isolated from psoas muscle of rabbit were spin-labelled with maleimide- and isothiocyanate-based probe\\u000a molecules at the reactive sulfhydryl

D. L?rinczy; B. Gaszner; F. Könczöl; J. Belágyi

2000-01-01

61

Comparison of SFI, DSC and NMR methods for determining solid-liquid ratios in fats  

Microsoft Academic Search

Dilatometry (SFI) has gained wide acceptance for the characterization of solid-liquid contents of fats over approximately\\u000a the past 15 years. In more recent times, wide-line nuclear magnetic resonance (NMR) has been used for this purpose. Still\\u000a more recently the differential scanning calorimetry (DSC) technique has been used to determine solid-liquid contents. These\\u000a three techniques were used to determine the properties

R. C. Walker; W. A. Bosin

1971-01-01

62

Determination of the terminal extent of starch gelatinization in a limited water system by DSC  

Microsoft Academic Search

Starch granules are gelatinized rapidly to reach a specified extent of gelatinization within 1 or 2 min. This upper limit to the extent of gelatinization may be termed the terminal extent of gelatinization (TEG) which depends on temperature and moisture content. TEG in wheat starch\\/water system (moisture content 0.54–3.0 g water\\/g starch) was measured by differential scanning calorimetry (DSC) in

Mika Fukuoka; Ken-ichi Ohta; Hisahiko Watanabe

2002-01-01

63

Thermal characterization and model free kinetics of aged epoxies and foams using TGA and DSC methods.  

SciTech Connect

Two classes of materials, poly(methylene diphenyl diisocyanate) or PMDI foam, and cross-linked epoxy resins, were characterized using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC), to help understand the effects of aging and %E2%80%9Cbake-out%E2%80%9D. The materials were evaluated for mass loss and the onset of decomposition. In some experiments, volatile materials released during heating were analyzed via mass spectroscopy. In all, over twenty materials were evaluated to compare the mass loss and onset temperature for decomposition. Model free kinetic (MFK) measurements, acquired using variable heating rate TGA experiments, were used to calculate the apparent activation energy of thermal decomposition. From these compiled data the effects of aging, bake-out, and sample history on the thermal stability of materials were compared. No significant differences between aged and unaged materials were detected. Bake-out did slightly affect the onset temperature of decomposition but only at the highest bake-out temperatures. Finally, some recommendations for future handling are made.

Cordaro, Joseph Gabriel; Kruizenga, Alan Michael; Nissen, April

2013-10-01

64

Entropy production in ac-calorimetry J.-L. Garden* and J. Richard  

E-print Network

1 Entropy production in ac-calorimetry J.-L. Garden* and J. Richard Institut Néel, CNRS et Université Joseph Fourier, BP 166, 38042 Grenoble Cedex 9, France. Abstract In calorimetry and particularly as dynamic. In a temperature modulated experiment, such as ac-calorimetry, these non-equilibrium experiments

Paris-Sud XI, Université de

65

PALS and DSC study of nanopores partially filled by hexadecane  

NASA Astrophysics Data System (ADS)

The controlled porosity glasses (CPG) filled with various amount of hexadecane (HXD) in nanopores were studied both by the positron annihilation lifetime spectroscopy (PALS) and the differential scanning calorimetry (DSC) methods. Two types of CPG matrices were used with average pore sizes 12.6 and 22.2 nm. The PALS measurements showed, that when the process of large pores filling by HXD has started, the long o-Ps lifetime went down to HXD o-Ps lifetime about 3ns [1]. DSC measurements at partially filled nanopores showed always two crystallization peaks [2]. Their positions depended on average pore size of matrix. Third crystallization peak was identified in overfilled samples (only short o-Ps lifetimes were present) and their position in temperature scale was the same as for the bulk HXD peak. The latter peak was independent of the average pore size of matrices. This fact confirms the assumption that processes studied by PALS with the samples that contained smaller amount of HXD in CPG occured inside of nanopores of the matrix.

Šauša, O.; Illeková, E.; Krištiak, J.; Berek, D.; Macová, E.

2013-06-01

66

DSC analysis of free-edged beams by an iteratively matched boundary method  

Microsoft Academic Search

This communication introduces a novel scheme for the treatment of free edge supports in the analysis of beams by using the discrete singular convolution (DSC) algorithm. Accommodating free edges has been a challenging issue in the DSC analysis of beams, plates, and shells. An iteratively matched boundary (IMB) method is proposed to overcome the difficulty. Numerical experiments are carried out

S. Zhao; G. W. Wei; Y. Xiang

2005-01-01

67

Crystalline fractionation of hydrogenated sunflowerseed oil. II. Differential scanning calorimetry (DSC)  

Microsoft Academic Search

This study explored the thermal behavior of hydrogenated sunflowerseed oil sample used in margarine manufacture, which had\\u000a been previously fractionated by crystallization at different temperatures. Calorimetric diagrams showed that areas per gram\\u000a were larger when solid samples, rather than liquids, were considered. Samples of high crystallization temperatures were found\\u000a to have components with high fusion points that were not present

M. L. Herrera; M. C. Añón

1991-01-01

68

Cure kinetics of epoxy matrix resin by differential scanning calorimetry  

NASA Technical Reports Server (NTRS)

A study was made on the cure kinetics of an epoxy neat-resin (Narmco 5208) using Differential Scanning Calorimetry (DSC). Two interrelated analytical methods were applied to dynamic DSC data for evaluating the kinetic parameters, such as activation energy, E, the order of reaction, n, and the total heat of polymerization (or crosslinking), delta H sub t. The first method was proposed by Ellerstein (1968), and uses a thorough differential-integral analysis of a single DSC curve to evaluate the kinetic parameters. The second method was proposed by Kissinger (1957), and uses multiple DSC curves obtained at various heating rates to evaluate E regardless of n. Kinetic analysis of Narmco 5208 epoxy resin showed that the reaction order, n, is substantially affected by the rate of heating; i.e., n is approximately 2 at slow scan rates but is reduced to 1.5 at higher scan rates. The activation energy, E, is not affected by the scan rate, and the average value of E is 25.6 + or - 1.8 kcal/mole.

Cizmecioglu, M.; Gupta, A.

1982-01-01

69

DSC Logistics Internship/Coop Program DSC Logistics is currently starting an internship/coop program and is looking to  

E-print Network

DSC Logistics Internship/Coop Program DSC Logistics is currently starting an internship backgrounds are encouraged to inquire. DSC has five IT­related positions are being considered, as outlined.stanley@dsclogistics.com. For more information about DSC visit www.dsclogistics.com. #12;DSC Logistics, a leading supply chain

Heller, Barbara

70

Micromegas for imaging calorimetry Maximilien Chefdeville on behalf of the LAPP/LC group  

E-print Network

Micromegas for imaging calorimetry Maximilien Chefdeville on behalf of the LAPP/LC group LAPP towards realistic calorimeter modules at a future collider experiment. 1. Introduction 1.1. Calorimetry in improved jet energy resolution [6]. 1.2. Micromegas for calorimetry Several calorimeter technologies

Paris-Sud XI, Université de

71

Characterization of the evaluation of the solid solubility of Si in sintered Fe-Si alloys using DSC technique  

SciTech Connect

Differential scanning calorimeter (DSC) is used to quantify the solid solubility of Si in sintered Fe-Si alloys. The calorimetry tests are run on Fe-Si alloys by arc melting and sintering. The relationship between the Curie temperature and the solid solubility of Si in Fe-Si alloys was determined using DSC. The solid solubility of Si in sintered Fe-Si alloys evaluated according to the relationship between magnetic transition and compositions can be compared with the results from a related quantitative electron probe microanalysis (EPMA)

Yuan, W.J. [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)]. E-mail: wjyuanwut@yahoo.com.cn; Li, R. [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083 (China); Shen, Q. [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Zhang, L.M. [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)

2007-04-15

72

Structure of stratum corneum lipids characterized by FT-Raman spectroscopy and DSC. II. Mixtures of ceramides and saturated fatty acids  

Microsoft Academic Search

Fourier transform (FT) Raman spectroscopy and differential scanning calorimetry (DSC) were used to study the thermotropic phase behaviour of mixtures of ceramides type IV (CER) and stearic acid (SA). For comparison the melting behaviour of SA was re-examined. The Raman spectra of all mixtures in the solid state show sharp bands associated with trans sequencies of the alkyl chain residues

Reinhard Neubert; Willi Rettig; Siegfried Wartewig; Matthias Wegener; Antje Wienhold

1997-01-01

73

Characterization of the Polycaprolactone Melt Crystallization: Complementary Optical Microscopy, DSC, and AFM Studies  

PubMed Central

The first stages of the crystallization of polycaprolactone (PCL) were studied using several techniques. The crystallization exotherms measured by differential scanning calorimetry (DSC) were analyzed and compared with results obtained by polarized optical microscopy (POM), rheology, and atomic force microscope (AFM). The experimental results suggest a strong influence of the observation scale. In particular, the AFM, even if limited on time scale, appears to be the most sensitive technique to detect the first stages of crystallization. On the contrary, at least in the case analysed in this work, rheology appears to be the least sensitive technique. DSC and POM provide closer results. This suggests that the definition of induction time in the polymer crystallization is a vague concept that, in any case, requires the definition of the technique used for its characterization. PMID:24523644

Speranza, V.; Sorrentino, A.; De Santis, F.; Pantani, R.

2014-01-01

74

DSC characterization of ion beam modifications in ion conducting PEO salt polymers  

NASA Astrophysics Data System (ADS)

Ion conducting polymer films have been prepared by complexing non-conducting poly-(ethylene-oxide), PEO, with x fraction of NH 4ClO 4 salt. Since its electrical conductivity showed a maximum at x somewhere between 0.18 and 0.19, such polymer films having 17 and 19 wt% salt, have been chosen and irradiated by 160 MeV Ne 6+ beam. The films have been investigated by differential scanning calorimetry (DSC) and ac impedance spectroscopy before and after the irradiations. Irradiation-induced shift of an endotherm in our DSC indicates a rise in the melting temperature from 54.6 °C to 57.9 °C for the 19% film. Cross-linking by the Ne-irradiation making the polymer structure more rigid can explain this as well as our other observation of a decrease in electrical conductivity.

Maitra, Minakshi; Verma, K. C.; Sinha, Mrinal; Kumar, Rajesh; Middya, T. R.; Tarafdar, S.; Sen, P.; Bandyopadhyay, S. K.; De, Udayan

2006-03-01

75

DSc and PhD Comparison Minimum Academic Requirements  

E-print Network

DSc and PhD Comparison DSc PhD Minimum Academic Requirements: 72 approved graduate units Course on a DSc "final program" provided they are approved by the Chair 3-9 maximum credit hours of independent Graduate Board and the SEAS Registrar's Office. Website and Policies: The SEAS rules and guidelines for DSc

Subramanian, Venkat

76

DSc and PhD Comparison Minimum Academic Requirements  

E-print Network

DSc and PhD Comparison DSc PhD Minimum Academic Requirements: 72 approved graduate units Course on a DSc "final program" provided they are approved by the Chair Three to nine maximum credit hours and the SEAS Registrar's Office. Website and Policies: The SEAS rules and guidelines for DSc students

Subramanian, Venkat

77

Determination of oxidation parameters by DSC for polypropylene stabilized with hydroxytyrosol (3,4-dihydroxy-phenylethanol)  

Microsoft Academic Search

Oxidation thermal parameters on samples of polypropylene (PP) stabilized with hydroxytyrosol were determined. For comparison\\u000a purposes, ?-tocopherol and a synthetic phenolic commercial antioxidant (Irganox 1076), were also analyzed. Oxidation induction\\u000a time (OIt) and oxidation induction temperature (OIT) were determined by differential scanning calorimetry (DSC). The addition\\u000a of hydroxytyrosol 0.1 mass% to PP was enough to obtain efficient stabilization during processing.

M. Peltzer; A. Jiménez

2009-01-01

78

Rheological and DSC study of sol-gel transition in aqueous dispersions of industrially important polymers and colloids  

Microsoft Academic Search

Gelation kinetics, mechanical spectra, thermal scanning rheology (TSR), and differential scanning calorimetry (DSC) in aqueous\\u000a solutions of gelling polymers and colloids such as seaweed polysaccharides (agarose, carrageenans), microbial polysaccharides\\u000a (gellan, curdlan), plant polysaccharides (methylcellulose), globular proteins (casein, glycinin, ?-conglycinin), fibrous proteins (gelatin, fibrin), and polyvinyl alcohol, which are related to foods, cosmetics, biomedical\\u000a and pharmaceutical applications, are described. Some gelation

Katsuyoshi Nishinari

1997-01-01

79

Lattice defect investigation of ECAP-Cu by means of X-ray line profile analysis, calorimetry and electrical resistometry  

Microsoft Academic Search

Cu rods have been deformed by equal channel angular pressing (ECAP) up to shear strains ??5 while applying various deformation paths A, BC and C. X-ray Bragg profile analyses (XPA), differential scanning calorimetry (DSC) as well as residual electrical resistivity (RER) measurements have been performed, in order to detect the densities of various deformation induced lattice defects and\\/or their arrangements.

E. Schafler; G. Steiner; E. Korznikova; M. Kerber; M. J. Zehetbauer

2005-01-01

80

Calorimetry: Summary and Conclusions  

E-print Network

We summarize the required developments to the calorimeter systems of the LHC experiments, for operation at HL-LHC. While the different technologies adopted for the existing calorimeter systems have a specific impact on the upgrade plans of each experiment, common requirements and strategies can nonetheless be identified, suggesting  possible synergies for the developments in detector, readout and trigger electronics.

Lanni, F; The ATLAS collaboration

2013-01-01

81

Melting of Single Lipid Components in Binary Lipid Mixtures: A Comparison between FTIR Spectroscopy, DSC and Monte Carlo Simulations  

E-print Network

Monte Carlo (MC) Simulations, Differential Scanning Calorimetry (DSC) and Fourier Transform InfraRed (FTIR) spectroscopy were used to study the melting behavior of single lipid components in two-component membranes of 1,2-Dimyristoyl-D54-sn-Glycero-3-Phosphocholine (DMPC-d54) and 1,2-Distearoyl-sn-Glycero-3-Phosphocholine (DSPC). Microscopic information on the temperature dependent melting of the single lipid species could be investigated using FTIR. The microscopic behavior measured could be well described by the results from the MC simulations. These simulations also allowed to calculate heat capacity profiles as determined with DSC. These ones provide macroscopic information about melting enthalpies and entropy changes which are not accessible with FTIR. Therefore, the MC simulations allowed us to link the two different experimental approaches of FTIR and DSC.

Fidorra, M; Seeger, H M

2007-01-01

82

DSC: a system for distributed symbolic computation  

Microsoft Academic Search

DSC is a general purpose tool that allows the distribution of a computation over a network of Unix workstations. Its control mechanisms automatically start up daemon processes on the participating workstations in order to communicate data by the standard IP\\/TCP\\/UDIP protocols. The user's program distributes either remote procedure calls or source code of programs and their corresponding input data files

A. Diaz; Erich Kaltofen; K. Schmitz; T. Valente

1991-01-01

83

CALORIMETRY OF TRU WASTE MATERIALS  

SciTech Connect

Calorimetry has been used for accountability measurements of nuclear material in the US. Its high accuracy, insensitivity to matrix effects, and measurement traceability to National Institute of Standards and Technology have made it the primary accountability assay technique for plutonium (Pu) and tritium in the Department of Energy complex. A measurement of Pu isotopic composition by gamma-ray spectroscopy is required to transform the calorimeter measurement into grams Pu. The favorable calorimetry attributes allow it to be used for verification measurements, for production of secondary standards, for bias correction of other faster nondestructive (NDA) methods, or to resolve anomalous measurement results. Presented in this paper are (1) a brief overview of calorimeter advantages and disadvantages, (2) a description of projected large volume calorimeters suitable for waste measurements, and (3) a new technique, direct measurement of transuranic TRU waste alpha-decay activity through calorimetry alone.

C. RUDY; ET AL

2000-08-01

84

Development of Imaging Calorimetry  

E-print Network

This paper will argue for continued effort in developing imaging calorimeters for future colliders and/or upgrades to existing detectors. Imaging calorimeters offer a plethora of advantages beyond their application in conjunction with Particle Flow Algorithms. Further R&D is needed to turn the first generation prototypes into viable detectors for colliding beam experiments.

Bilki, Burak; Xia, Lei

2013-01-01

85

Thermal stability and molecular microstructure of heat-induced cereal grains, revealed with Raman molecular microspectroscopy and differential scanning calorimetry.  

PubMed

The objectives of the present study were to use Raman molecular microspectroscopy and differential scanning calorimetry (DSC) to reveal molecular thermal stability and thermal degradation behavior of heat-induced cereal grains and reveal the molecular chemistry of the protein structures of cereal grain tissues affected by heat processing and to quantify the protein secondary structures using multicomponent peak modeling Gaussian and Lorentzian methods. Hierarchical cluster analysis (CLA) and principal components analysis (PCA) were also conducted to identify molecular differences in the Raman spectra. Three cereal grain seeds, wheat, triticale, and corn, were used as the model for feed protein in the experiment. The specimens were autoclaved (moist heating) and dry-heated (roasted) at 121 °C for 80 min, respectively. Raman spectroscopy results revealed that there are marked differences in the secondary structures of the proteins subjected to various heating treatments of different cereals. The sensitivity of cereals to moist heating was much higher than the sensitivity to dry heating. The multivariate analyses (CLA and PCA) showed that heat treatment was significantly isolated between the different Raman raw spectra. The DSC study revealed that the thermal degradation behavior of cereals was significantly changed after moist- and dry-heat treatments. The position of the major endothermic peak of dry-heated cereals shifted toward a higher temperature, from 131.7 to 134.0 °C, suggesting the high thermal stability of dry-heated cereals. In contrast, the endothermic peak position was slightly decreased to 132.1 °C in the case of moist autoclaved heating. The digestive behavior and nutritive value of rumen-undegradable protein in animals may be related to the changes of the protein secondary molecular structure and thermal stability of the cereal grain materials, which is attributed by Raman microspectroscopy and DSC endotherm profiles. PMID:23724957

Khan, Md Majibur Rahman; Yu, Peiqiang

2013-07-01

86

Contactless Calorimetry for Levitated Samples  

NASA Technical Reports Server (NTRS)

Temperature and specific heat of hot sample measured with pyrometer in proposed experimental technique. Technique intended expecially for contactless calorimetry of such materials as undercooled molten alloys, samples of which must be levitated to prevent contamination and premature crystallization. Contactless calorimetry technique enables data to be taken over entire undercooling temperature range with only one sample. Technique proves valuable in study of undercooling because difference in specific heat between undercooled-liquid and crystalline phases at same temperature provides driving force to convert metastable undercooled phase to stable crystalline phase.

Lee, M. C.; Dokko, W.

1986-01-01

87

Calorimetry end-point predictions  

SciTech Connect

This paper describes a portion of the work presently in progress at Rocky Flats in the field of calorimetry. In particular, calorimetry end-point predictions are outlined. The problems associated with end-point predictions and the progress made in overcoming these obstacles are discussed. The two major problems, noise and an accurate description of the heat function, are dealt with to obtain the most accurate results. Data are taken from an actual calorimeter and are processed by means of three different noise reduction techniques. The processed data are then utilized by one to four algorithms, depending on the accuracy desired to determined the end-point.

Fox, M. A.

1981-04-11

88

Thermal behavior and phase identification of Valsartan by standard and temperature-modulated differential scanning calorimetry.  

PubMed

Thermal behavior of angiotensin II type 1 (AT1) receptor antagonist, Valsartan (VAL), was examined employing thermogravimetric analysis (TGA), standard differential scanning calorimetry (DSC) and temperature-modulated differential scanning calorimetry (TMDSC). The stability of VAL was measured by TGA from 25 to 600°C. Decomposition of Valsartan starts around 160°C. The DSC curve shows two endotherms, occurring around 80°C and 100°C, related to evaporation of water and enthalpy relaxation, respectively. Valsartan was identified by DSC as an amorphous material and it was confirmed by X-ray powder diffraction. The glass transition of fresh Valsartan appears around 76°C (fictive temperature). TMDSC allows separation of the total heat flow rate into reversing and nonreversing parts. The nonreversing curve corresponds to the enthalpy relaxation and the reversing curve shows changes of heat capacity around 94°C. In the second run, TMDSC curve shows the glass transition process occurring at around 74°C. Results from standard DSC and TMDSC of Valsartan were compared over the whole range of temperature. PMID:22803969

Skotnicki, Marcin; Gawe?, Agnieszka; Cebe, Peggy; Pyda, Marek

2013-10-01

89

Development of Particle Flow Calorimetry  

E-print Network

This talk reviews the development of imaging calorimeters for the purpose of applying Particle Flow Algorithms (PFAs) to the measurement of hadronic jets at a future lepton collider. After a short introduction, the current status of PFA developments is presented, followed by a review of the major developments in electromagnetic and hadronic calorimetry.

Jose Repond

2011-10-10

90

Mound calorimetry for explosive surveillance  

SciTech Connect

Heat of reaction determinations of pyrotechnics and explosives is made at MRC-Mound by bomb calorimetry. Energy releases from ten calories to 94 kilocalories have been measured accurately using four different calorimeter systems. Each system is described and some heat of reaction results are given. 3 figs., 4 tabs.

Shockey, G.C.; Rodenburg, W.W.

1985-01-01

91

Thermal analysis of palm stearine by DSC  

Microsoft Academic Search

The chemical composition and thermal properties of palm stearine have been investigated. The sample consists of triglycerides\\u000a containing mainly the fatty acid residues: palmitic (P) 51.4%; oleic (O) 32.7%; linoleic (L) 8.3% and stearic (S) 5.0%. The\\u000a sample melts as almost two independent components in separate temperature ranges. DSC analysis and analogy with the work of\\u000a Persmarket al. (1) indicate

W. Ken Busfield; Peter N. Proschogob

1990-01-01

92

Nanoscale Calorimetry of Isolated Polyethylene Single Crystals  

E-print Network

Nanoscale Calorimetry of Isolated Polyethylene Single Crystals A. T. KWAN, M. YU. EFREMOV, E. A-film differential scanning calorimetry to investigate the melt- ing of isolated polyethylene single crystals: microelectromechanical systems; calorimetry; nanocalorimetry; polyeth- ylene single crystals; melting INTRODUCTION We

Allen, Leslie H.

93

Differential scanning calorimetry of coal  

NASA Technical Reports Server (NTRS)

Differential scanning calorimetry studies performed during the first year of this project demonstrated the occurrence of exothermic reactions associated with the production of volatile matter in or near the plastic region. The temperature and magnitude of the exothermic peak were observed to be strongly affected by the heating rate, sample mass and, to a lesser extent, by sample particle size. Thermal properties also were found to be influenced by oxidation of the coal sample due to weathering effects.

Gold, P. I.

1978-01-01

94

The use of differential scanning calorimetry for the purity verification of pharmaceutical reference standards.  

PubMed

Reference standards are routinely used in pharmaceutical industry to determine strength, content, and the quality of drug products, active pharmaceutical ingredients (API), preservatives, antioxidants and excipients. Traditionally, chromatographic techniques such as High Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC) in conjunction with other analytical techniques have been used to determine the purity and strength of a specific lot of a compound for the purpose of qualifying the lot to use as a reference standard. The assigned purity of the reference standard for a wide variety of compounds can be verified using an absolute method such as Differential Scanning Calorimetry (DSC). In this paper, purity of 16 reference standards was determined by DSC and the results were then compared to the purity values that were obtained using HPLC and other analytical techniques. The results indicate that the purity obtained from DSC analysis is comparable to the chromatographic purity for organic compounds that are at least 98% pure. Use of DSC for purity determination is not appropriate if a compound lacks sharp melting point, decomposes in the defined temperature range or exhibits other thermal event(s) which interfere with the melting point of the compound. The use of DSC as an alternative and or complementary method to verify the purity of a compound as part of the pharmaceutical reference standard certification process is discussed. PMID:19186017

Mathkar, S; Kumar, S; Bystol, A; Olawoore, K; Min, D; Markovich, R; Rustum, A

2009-04-01

95

Characterization of oil shales by differential scanning calorimetry  

SciTech Connect

Oil shale blocks were cored to suitable dimensions (nominally 2.5 cm diameter and 1 cm thick). Specific gravity measurements were then carried out on these cylindrical cores to determine the organic content. Selected samples were also assayed at Laramie Energy Technology Center, WY, by the pulsed NMR technique. Oil yields obtained by the two methods on identical cores were in agreement with the limits of experimental error (vide infra). The cored shale samples were crushed to particles which passed through 100-mesh sieves. Ten to fifteen milligram batches of these crushed shale particles were then subjected to enthalpy measurements in the differential scanning calorimetry assembly. A sample of kerogen concentrate was obtained from Laramie Energy Technology Center. DSC measurements were carried out on a DuPont 990 thermal analysis system fitted with the DSC accessory module. All measurements were carried out in a flowing atmosphere of prepurified N/sub 2/. A heating rate of 10/sup 0/C/min was employed for the enthalpy determinations. The fusion endotherm of zinc (mp 419.4/sup 0/C, ..delta..H/sub f/ = 27.05 cal/g) was used as the calibration standard. The linear correlation that was observed between the enthalpy of decomposition of the organic matter (..delta..H) and oil yields for Green river oil shales suggests that this technique might be useful as a rapid screening tool for resource evaluation of an oil shale deposit.

Rajeshwar, K.; Jones, D.B.; DuBow, J.B.

1981-01-01

96

Calorimetry applied to nucleus-nucleus collisions at ultrarelativistic energies  

SciTech Connect

A general introduction to high-energy calorimetry is presented, together with brief descriptions of the two types of cascades relevant to calorimetric measurements. This is followed by a discussion of ''compensation'' and of the ''e/h'' ratio. A detailed description of two calorimeters designed and constructed for the CERN WA80 experiment are also given. 16 refs., 17 figs., 5 tabs.

Plasil, F.

1988-01-01

97

Elucidation of inclusion compounds between ?-cyclodextrin\\/local anaesthetics structure: a theoretical and experimental study using differential scanning calorimetry and molecular mechanics  

Microsoft Academic Search

Two local anaesthetics, Bupivacaine (BVC) and Lidocaine (LDC), were studied by experimental as well as theoretical methods. These compounds were associated with a drug delivery system of cyclodextrins (CDs). We used Differential Scanning Calorimetry (DSC) for experimental measurements. We calculated enthalpy change for the process of association between drug and CD. Calculations were performed using Molecular Mechanics (MM) with MM+

Luciana M. A. Pinto; Marcelo B. de Jesus; Eneida de Paula; Antonio C. S. Lino; Joel B. Alderete; Helio A. Duarte; Yuji Takahata

2004-01-01

98

Differential Scanning Calorimetry Study of Normal Portland Cement Paste with 30% Fly Ash Replacement and of the Separate Fly Ash and Ground Granulated Blast-Furnace Slag Powders  

Microsoft Academic Search

Synopsis: This paper reports a differential scanning calorimetry (DSC) study of the hydration and pozzolanic processes in normal portland cement paste containing fly ash. First, the thermal stability of fly ash powder was investigated, the result showing mainly the crystallisation of the amorphous phase(s) in the material. The heat evolution during constant rate heating of a normal portland cement paste

W. Sh; G. B. Pereira

99

Experimental study of the influence of solvent and asphaltenes on liquid–solid phase behavior of paraffinic model systems by using DSC and FT-IR techniques  

Microsoft Academic Search

This experimental work presents the results of a study about the liquid–solid phase behavior of high molecular weight n-paraffins (C24–C28 mixture and C36 pure) in aliphatic (n-decane and squalane) and aromatic (xylene and 1-phenyl dodecane) solvents. The effect of asphaltenes of different chemical\\u000a nature over the liquid–solid behavior of heavy n-paraffins is also studied. Differential Scanning Calorimetry (DSC) was used

Luis Alberto Alcazar-Vara; Eduardo Buenrostro-Gonzalez

100

DSC: Scheduling Parallel Tasks on an Unbounded Number of Processors  

Microsoft Academic Search

We present a low-complexity heuristic, named the dominant sequence clusteringalgorithm (DSC), for scheduling parallel tasks on an unbounded number of completelyconnected processors. The performance of DSC is on average, comparable to, or evenbetter than, other higher-complexity algorithms. We assume no task duplication andnonzero communication overhead between processors. Finding the optimum solution forarbitrary directed acyclic task graphs (DAG's) is NP-complete. DSC

Tao Yang; Apostolos Gerasoulis

1994-01-01

101

Determination of kinetics parameters of glass transition in glassy Se and glassy Se98M2 alloys using DSC technique  

NASA Astrophysics Data System (ADS)

Glassy Se and Se98M2 (M = Ag, Cd, Zn) alloys are obtained by the melt quenching technique. Differential Scanning Calorimetry (DSC) technique (under non-isothermal conditions) has been applied to see the effects of Ag, Cd, and Zn additives on the glass transition kinetics of Se-rich glassy alloys at different heating rates. The variation of glass transition temperature, T g with the heating rate, ? has been used to investigate the glass transition kinetics. The values of various kinetic parameters such as glass transition temperature, activation energy of glass transition, overall mean bond energy < E>, heat of atomization H S , bond strength (Se-M) have also been calculated.

Dohare, C.; Mehta, N.

2014-02-01

102

Characterization of melting properties in dark chocolates from varying particle size distribution and composition using differential scanning calorimetry  

Microsoft Academic Search

Melting properties in dark chocolates processed from varying particle size distribution (PSD), fat and lecithin content were studied using differential scanning calorimetry (DSC). Compositional parameters were PSD (D90 (90% finer than this size) of 18, 25, 35 and 50?m), fat (25%, 30% and 35%) and lecithin (0.3% and 0.5%) contents. Variations in PSD had no influence on crystallinity of products.

Emmanuel Ohene Afoakwa; Alistair Paterson; Mark Fowler; Joselio Vieira

2008-01-01

103

FTIR and DSC studies of the thermal and photochemical stability of Balanites aegyptiaca oil (Toogga oil).  

PubMed

The oil extracted from the bean of Balanites aegyptiaca was characterized, and its photochemical and thermal stabilization were evaluated. The chemical composition was determined using gas chromatography (GC), revealing that the oil is very rich in unsaturated fatty acids (72% omega-6 and omega-9). The photochemical stability was assessed by subjecting it to artificially accelerated photo-aging and then examining the changes using infrared spectroscopy. The thermal stability was studied at six different temperatures ranging from 130 to 200°C and monitored in situ by differential scanning calorimetry (DSC). The kinetic parameters (EA and k) describing the thermal degradation of this oil were calculated. It has been shown that the antioxidants present in the oil delay the oxidation process (induction period). The degradation of the Toogga oil was compared with that of oleic and linoleic fatty acids. In addition, the degradation of the Toogga oil extracted with hexane was compared to that of the neat oil. PMID:23470324

Gardette, Jean-Luc; Baba, Mohamed

2013-01-01

104

REDES DE COMPUTADORES UFPB / CCT / DSC / PSN, 2001 * Parte 4: Estudo de Caso -DSC * Pg. 1  

E-print Network

de iniciação científica LSD - Laboratório de Sistemas Distribuídos, de uso específico dos Firewall DSC Server 1 UNIX Server 2 UNIX Server 1 Windows LabCom LSD LEPRECOM LSI LabPetri LAD LIA Miniblio ao setor (no caso do LSD, LEPRECOM, LSI, LIA e LabPetri). ! Os setores (nuvens) em amarelo, usam

Cirne, Walfredo

105

Micromegas for imaging hadronic calorimetry  

E-print Network

The recent progress in R&D of the Micromegas detectors for hadronic calorimetry including new engineering-technical solutions, electronics development, and accompanying simulation studies with emphasis on the comparison of the physics performance of the analog and digital readout is described. The developed prototypes are with 2 bit digital readout to exploit the Micromegas proportional mode and thus improve the calorimeter linearity. In addition, measurements of detection efficiency, hit multiplicity, and energy shower profiles obtained during the exposure of small size prototypes to radioactive source quanta, cosmic particles and accelerator beams are reported. Eventually, the status of a large scale chamber (1{\\times}1 m2) are also presented with prospective towards the construction of a 1 m3 digital calorimeter consisting of 40 such chambers.

C. Adloff; J. Blaha; S. Cap; M. Chefdeville; A. Dalmaz; C. Drancourt; A. Espargiliere; R. Gaglione; R. Gallet; N. Geffroy; J. Jacquemier; Y. Karyotakis; F. Peltier; J. Prast; G. Vouters

2011-02-07

106

Differential Scanning Calorimetry and Evolved Gas Analysis at Mars Ambient Conditions Using the Thermal Evolved Gas Analyser (TEGA)  

NASA Technical Reports Server (NTRS)

Differential Scanning Calorimetry (DSC) combined with evolved gas analysis (EGA) is a well developed technique for the analysis of a wide variety of sample types with broad application in material and soil sciences. However, the use of the technique for samples under conditions of pressure and temperature as found on other planets is one of current development and cutting edge research. The Thermal Evolved Gas Analyzer (TEGA), which was designed, built and tested at the University of Arizona's Lunar and Planetary Lab (LPL), utilizes DSC/EGA. TEGA, which was sent to Mars on the ill-fated Mars Polar Lander, was to be the first application of DSC/EGA on the surface of Mars as well as the first direct measurement of the volatile-bearing mineralogy in martian soil. Additional information is available in the original extended abstract.

Musselwhite, D. S.; Boynton, W. V.; Ming, D. W.; Quadlander, G.; Kerry, K. E.; Bode, R. C.; Bailey, S. H.; Ward, M. G.; Pathare, A. V.; Lorenz, R. D.

2000-01-01

107

Differential Scanning Calorimetry and Evolved Gas Analysis at Mars Ambient Conditions Using the Thermal Evolved Gas Analyzer (TEGA)  

NASA Technical Reports Server (NTRS)

Differential Scanning Calorimetry (DSC) combined with evolved gas analysis (EGA) is a well developed technique for the analysis of a wide variety of sample types with broad application in material and soil sciences. However, the use of the technique for samples under conditions of pressure and temperature as found on other planets is one of current C development and cutting edge research. The Thermal Evolved Gas Analyzer (MGA), which was designed, built and tested at the University of Arizona's Lunar and Planetary Lab (LPL), utilizes DSC/EGA. TEGA, which was sent to Mars on the ill-fated Mars Polar Lander, was to be the first application of DSC/EGA on the surface of Mars as well as the first direct measurement of the volatile-bearing mineralogy in martian soil.

Musselwhite, D. S.; Boynton, W. V.; Ming, Douglas W.; Quadlander, G.; Kerry, K. E.; Bode, R. C.; Bailey, S. H.; Ward, M. G.; Pathare, A. V.; Lorenz, R. D.

2000-01-01

108

Elastic flexibility, fast-ion conduction, boson and floppy modes in AgPO3AgI glasses examined in Raman scattering, infrared reflectance, modulated differential scanning calorimetry, ac electrical conductivity and molar volume experiments  

Microsoft Academic Search

Raman scattering, IR reflectance and modulated DSC measurements are performed on specifically prepared dry (AgI)x(AgPO3)1-x glasses over a wide range of compositions 0 < x < 60%. A reversibility window is observed in the 9.5 %< x < 37.8 % range, which fixes the elastically rigid but unstressed regime also known as the Intermediate Phase. Glass compositions at x <

Deassy I. Novita; P. Boolchand; M. Malki

109

Estimation Method for Liquidus Temperature of Lead-Free Solder Using Differential Scanning Calorimetry Profiles  

NASA Astrophysics Data System (ADS)

It is usually complicated to analyze the liquidus temperature of lead-free solder, because unlike Sn-Pb eutectic solder, supercooling easily occurs during the cooling process of lead-free solder, and common lead-free solders contain only a small fraction of a primary phase. In order to determine the melting temperature range of lead-free solder easily, an estimation method using differential scanning calorimetry (DSC) profiles is proposed. The purpose of this study is to show the applicability of the newly proposed DSC-based approach. DSC profiles using several heating rates were measured and analyzed. As a result, it was found that the extrapolated onset temperature, the peak temperature, and the extrapolated end temperature of the endothermic peak were proportional to the square root of the DSC heating rate. For lower heating rate, the temperature-axis intercept of the relationship between the square root of the heating rate and the peak temperature can be regarded as the liquidus temperature under equilibrium conditions with better accuracy. For higher heating rate, the temperature-axis intercept of the relationship between the square root of the heating rate and the extrapolated end temperature can be approximately estimated as the liquidus temperature of noneutectic lead-free solder under equilibrium conditions.

Nishikawa, Hiroshi; Hamada, Yoshihito; Takemoto, Tadashi

2009-12-01

110

REVIEW ARTICLE: Water calorimetry for radiation dosimetry  

Microsoft Academic Search

Calorimetry has a long history as a technique for establishing the absorbed dose, and graphite calorimetry has often been used to establish absorbed dose standards for use in radiation therapy. However, a conversion process is necessary to convert from dose to graphite to dose to water, which is the quantity of clinical interest. In order to more directly measure the

C. K. Ross; N. V. Klassen

1996-01-01

111

Interactions of tamoxifen with distearoyl phosphatidylcholine multilamellar vesicles: FTIR and DSC studies  

NASA Astrophysics Data System (ADS)

Interactions of a non-steroidal antiestrogen drug, tamoxifen (TAM), with distearoyl-sn-glycero-3-phosphatidylcholine (DSPC) multilamellar liposomes (MLVs) were investigated as a function of drug concentration (1-15 mol%) by using two noninvasive techniques, namely Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). FTIR spectroscopy results show that increasing TAM concentrations (except 1 mol%) increased the wavenumbers of the CH2 stretching modes, implying an disordering effect for DSPC MLVs both in the gel and liquid crystalline phases. The bandwidth values of the CH2 stretchings except for 1 mol% increased when TAM concentrations increased for DSPC liposomes, indicating an increase in the dynamics of liposomes. The Cdbnd O stretching and PO2- antisymmetric double bond stretching bands were analyzed to study interactions of TAM with head groups of lipids. As the concentrations of TAM increased, dehydration occurred around these functional groups in the polar part of the lipids. The DSC studies on thermal properties of DSPC lipids indicate that TAM eliminated the pre transition, shifted the main phase transition to lower temperatures and broadened the phase transition curve of the liposomes.

Bilge, Duygu; Sahin, Ipek; Kazanci, Nadide; Severcan, Feride

2014-09-01

112

FTIR, DSC, WAXS and density study of cold crystallized isotactic polystyrene  

NASA Astrophysics Data System (ADS)

The techniques of Fourier transform infrared (FTIR) spectroscopy, wide-angle X-ray scattering(WAXS), density measurement and differential scanning calorimetry (DSC) were used to study the cold crystallization behavior of isotactic polystyrene (iPS) films cold-crystallized at 140C and 170C for various times. It was observed from FTIR that the intensity of the peak at 981 cm-1 increases with crystallization time and this reflects the manner of crystallization. The degree of crystallinity was obtained from DSC by heat of fusion calculation, from WAXS by the crystal peak area after amorphous phase subtraction and from density measurement by two-phase model density calculation. Crystallinity determined by any method exhibits a correlation with the absorption peak intensity ratio I981cm-1/I1026cm-1 , obtained from FTIR. Such a correlation provides us a way to study the crystallization process for iPS thin films. The FTIR spectra of crystallized thin film was taken for films spin cast from solution on KBr disks. For the first time, crystallinity of iPS thin films was obtained by the reference to the correlation curves between the FTIR peak intensity ratio and crystallinity developed for bulk film.

Xu, Hui; Ince, B. Seyhan; Gilfoy, Nathan; Cebe, Peggy

2003-03-01

113

SAXS/WAXS/DSC Study of Temperature Evolution in Nanopolymer Electrolyte  

E-print Network

Electrolytes as nanostructured materials are very attractive for batteries or other types of electronic devices. (PEO)8ZnCl2 polymer electrolytes and nanocomposites (PEO)8ZnCl2/TiO2 were prepared from PEO and ZnCl2 and with addition of TiO2 nanograins. The influence of TiO2 nanograins was studied by small-angle X-ray scattering (SAXS) simultaneously recorded with wide-angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC) at the synchrotron ELETTRA. It was shown by previous impedance spectroscopy (IS) that the room temperature conductivity of nanocomposite polymer electrolyte increased more than two times above 65oC, relative to pure composites of PEO and salts. The SAXS/DSC measurements yielded insight into the temperature-dependent changes of the grains of the electrolyte as well as to differences due to different heating and cooling rates. The crystal structure and temperatures of melting and crystallization of the nanosize grains was revealed by the simultaneous WAXS measurements.

Aleksandra Turkovic; Mario Rakic; Pavo Dubcek; Magdy Lucic-Lavcevic; Sigrid Bernstorff

2008-09-03

114

Large eddy approximation of turbulent flow in DSC schemes  

E-print Network

Large eddy approximation of turbulent flow is given a natural setting within the DSC framework of computational fluid dynamics. Periodic cellular coarse-graining prevents the nodal flow from piling up and preserves its large patterns. The coarsening operations are consistent with the near-field interaction principle of DSC and - therefore - uncomplicated at boundaries. Numerical examples validate the approach.

Steffen Hein

2006-03-30

115

Macroscopic non-equilibrium thermodynamics in dynamic calorimetry  

E-print Network

What is really measured in dynamic calorimetric experiments is still an open question. This paper is devoted to this question, which can be usefully envisaged by means of macroscopic non-equilibrium thermodynamics. From the pioneer work of De Donder on chemical reactions and with other authors along the 20th century, the question is tackled under an historical point of view. A special attention is paid about the notions of frequency dependent complex heat capacity and entropy production due to irreversible processes occurring during an experiment. This phenomenological approach based on thermodynamics, not widely spread in the literature of calorimetry, could open significant perspectives on the study of macro-systems undergoing physico-chemical transformations probed by dynamic calorimetry.

Jean-Luc Garden

2007-06-28

116

Accurate Measurement of Heat Capacity by Differential Scanning Calorimetry  

NASA Technical Reports Server (NTRS)

Experience with high quality heat capacity measurement by differential scanning calorimetry is summarized and illustrated, pointing out three major causes of error: (1) incompatible thermal histories of the sample, reference and blank runs; (2) unstable initial and final isotherms; (3) incompatible differences between initial and final isotherm amplitudes for sample, reference and blank runs. Considering these problems, it is shown for the case of polyoxymethylene that accuracies in heat capacity of 0.1 percent may be possible.

1984-01-01

117

Calibration of Chemical Kinetic Models Using Simulations of Small-Scale Cookoff Experiments  

SciTech Connect

Establishing safe handling limits for explosives in elevated temperature environments is a difficult problem that often requires extensive simulation. The largest influence on predicting thermal cookoff safety lies in the chemical kinetic model used in these simulations, and these kinetic model reaction sequences often contain multiple steps. Several small-scale cookoff experiments, notably Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), One-Dimensional Time-to-Explosion (ODTX), and the Scaled Thermal Explosion (STEX) have been performed on various explosives to aid in cookoff behavior determination. Past work has used a single test from this group to create a cookoff model, which does not guarantee agreement with the other experiments. In this study, we update the kinetic parameters of an existing model for the common explosive 2,4,6-Trinitrotoluene (TNT) using DSC and ODTX experimental data at the same time by minimizing a global Figure of Merit based on hydrodynamic simulated data. We then show that the new kinetic model maintains STEX agreement, reduces DSC agreement, and improves ODTX and TGA agreement when compared to the original model. In addition, we describe a means to use implicit hydrodynamic simulations of DSC experiments to develop a reaction model for TNT melting.

Wemhoff, A P; Becker, R C; Burnham, A K

2008-02-26

118

Automatic calorimetry system monitors RF power  

NASA Technical Reports Server (NTRS)

Calorimetry system monitors the average power dissipated in a high power RF transmitter. Sensors measure the change in temperature and the flow rate of the coolant, while a multiplier computes the power dissipated in the RF load.

Harness, B. W.; Heiberger, E. C.

1969-01-01

119

Performance of Particle Flow Calorimetry at CLIC  

E-print Network

The particle flow approach to calorimetry can provide unprecedented jet energy resolution at a future high energy collider, such as the International Linear Collider (ILC). However, the use of particle flow calorimetry at the proposed multi-TeV Compact Linear Collider (CLIC) poses a number of significant new challenges. At higher jet energies, detector occupancies increase, and it becomes increasingly difficult to resolve energy deposits from individual particles.

Marshall, J.S.; Thomson, M.A.

2013-01-01

120

Ottimizzazione di algoritmi di deconvoluzione applicati alla DSC-MRI.  

E-print Network

??La quantificazione dell’emodinamica cerebrale risulta particolarmente importante nello studio di patologie come neoplasie cerebrali, sclerosi multipla, ischemie e infarti. La DSC-MRI è una delle tecniche… (more)

Benozzo, Danilo

2012-01-01

121

A study of gamma-irradiated polyethylenes by temperature modulated differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

Various polyethylenes (PEs) and the effects of high-energy radiation on their structures were widely studied in the past using conventional Differential Scanning Calorimetry (DSC) measurements. In this work, we used the Temperature Modulated Differential Scanning Calorimetry (TMDSC) technique in order to obtain more information about the influence of the initial structural differences and gamma radiation on the evolution in structure and thermal properties of different polyethylenes. For this reason, low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and high density polyethylene (HDPE) samples were exposed to gamma radiation, in air, to a wide range of absorbed doses (up to 2400 kGy). The separation of the total heat flow TMDSC signal into a reversing and non-reversing part enabled us to observe the low-temperature enthalpy relaxation (related to the existence of the "rigid amorphous phase") and recrystallisation processes, as well as to follow their radiation-induced evolution and/or that of melting in a more revealing manner compared to the case of the conventional DSC. Consequently, our results indicate that TMDSC could improve the understanding of radiation-induced effects in polymers.

Galovic, S.; Secerov, B.; Trifunovic, S.; Milicevic, D.; Suljovrujic, E.

2012-09-01

122

DSC time-domain solution of Maxwell’s equations  

Microsoft Academic Search

A new computational algorithm, the discrete singular convolution (DSC), is introduced for solving scattering and guided wave problems described by time-domain Maxwell’s equations. The DSC algorithm is utilized for the spatial discretization and the fourth-order Runge–Kutta scheme is used for the time advancing. Staggered meshes are used for electromagnetic fields. Four standard test problems, a hollow air-filled waveguide, a dielectric

Zhenhai Shao; G. W. Wei; Shan Zhao

2003-01-01

123

The DSC thermal analysis of crystallization behavior in palm oil  

Microsoft Academic Search

Polymorphic behavior of palm oil crystals was studied by DSC isothermal analysis and microscopic observation. Different crystal\\u000a forms developed specific spherulites depending on the degree of super-cooling from the melt. The A-form crystal was capable\\u000a of forming a dotted spherulite and the B-form crystal of forming a dendritic spherulite. Experimental results of B form crystallization\\u000a studied by the DSC and

K. Kawamura

1979-01-01

124

47 CFR 80.359 - Frequencies for digital selective calling (DSC).  

Code of Federal Regulations, 2011 CFR

...Frequencies for digital selective calling (DSC). 80.359 Section 80.359 Telecommunication...Frequencies for digital selective calling (DSC). (a) General purpose calling. ...ship and coast stations for general purpose DSC. There are three series of...

2011-10-01

125

47 CFR 80.103 - Digital selective calling (DSC) operating procedures.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Digital selective calling (DSC) operating procedures. 80.103 Section...80.103 Digital selective calling (DSC) operating procedures. (a) Operating procedures for the use of DSC equipment in the maritime mobile...

2010-10-01

126

47 CFR 80.103 - Digital selective calling (DSC) operating procedures.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Digital selective calling (DSC) operating procedures. 80.103 Section...80.103 Digital selective calling (DSC) operating procedures. (a) Operating procedures for the use of DSC equipment in the maritime mobile...

2012-10-01

127

47 CFR 80.103 - Digital selective calling (DSC) operating procedures.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Digital selective calling (DSC) operating procedures. 80.103 Section...80.103 Digital selective calling (DSC) operating procedures. (a) Operating procedures for the use of DSC equipment in the maritime mobile...

2011-10-01

128

47 CFR 80.103 - Digital selective calling (DSC) operating procedures.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Digital selective calling (DSC) operating procedures. 80.103 Section...80.103 Digital selective calling (DSC) operating procedures. (a) Operating procedures for the use of DSC equipment in the maritime mobile...

2013-10-01

129

47 CFR 80.359 - Frequencies for digital selective calling (DSC).  

Code of Federal Regulations, 2010 CFR

...Frequencies for digital selective calling (DSC). 80.359 Section 80.359 Telecommunication...Frequencies for digital selective calling (DSC). (a) General purpose calling. ...ship and coast stations for general purpose DSC. There are three series of...

2010-10-01

130

47 CFR 80.359 - Frequencies for digital selective calling (DSC).  

Code of Federal Regulations, 2012 CFR

...Frequencies for digital selective calling (DSC). 80.359 Section 80.359 Telecommunication...Frequencies for digital selective calling (DSC). (a) General purpose calling. ...ship and coast stations for general purpose DSC. There are three series of...

2012-10-01

131

Thermal degradation of ligno-cellulosic fuels: DSC and TGA studies  

E-print Network

The scope of this work was to show the utility of thermal analysis and calorimetric experiments to study the thermal oxidative degradation of Mediterranean scrubs. We investigated the thermal degradation of four species; DSC and TGA were used under air sweeping to record oxidative reactions in dynamic conditions. Heat released and mass loss are important data to be measured for wildland fires modelling purpose and fire hazard studies on ligno-cellulosic fuels. Around 638 and 778 K, two dominating and overlapped exothermic peaks were recorded in DSC and individualized using a experimental and numerical separation. This stage allowed obtaining the enthalpy variation of each exothermic phenomenon. As an application, we propose to classify the fuels according to the heat released and the rate constant of each reaction. TGA experiments showed under air two successive mass loss around 638 and 778 K. Both techniques are useful in order to measure ignitability, combustibility and sustainability of forest fuels.

Leroy, Valérie; Leoni, Eric; 10.1016/j.tca.2006.09.017

2008-01-01

132

Assignment of the human genes for Desmocollin 3 (DSC3) and Desmocollin 4 (DSC4) to chromosome 18q12  

SciTech Connect

Desmosomes are adhesive intercellular junctions that contain two transmembrane components, desmoglein and desmocollin. cDNA cloning has revealed that both components are members of the cadherin supergene family and consist of multiple isotypes. Desmogleins (Dsg) have three isotypes, Dsg1, Dsg2, and Dsg3. Dsg1 and Dsg3 are also the target antigens of autoimmune blistering diseases, pemphigus foliaceus and pemphigus vulgaris, respectively. Previously, we have demonstrated that the human genes for Dsg1 and Dsg3 are located on chromosome 18q12 by fluorescence in situ hybridization (FISH). Furthermore, both genes were localized on a 320-kb genomic fragment separated by pulsed-field gel electrophoresis. For desmocollins (Dsc for protein, DSC for gene), human cDNAs for Dsc1 and Dsc3 have been isolated from three currently known isotypes. In this study, we report that human genes for Dsc3 and a novel desmocollin, Dsc4, are located on chromosome 18q12 as determined by FISH, suggesting a cluster for desmosomal cadherins on chromosome 18. 14 refs., 1 fig.

Amagai, Masayuki; Nishikawa, Takeji; Wang, Yimin [Keio Univ. School of Medicine, Shinjuku-ku, Tokyo (Japan)] [and others] [Keio Univ. School of Medicine, Shinjuku-ku, Tokyo (Japan); and others

1995-01-01

133

Effect of urea on phase transition of poly(N-isopropylacrylamide) investigated by differential scanning calorimetry.  

PubMed

The effect of urea on the phase transition of PNIPAM was studied using differential scanning calorimetry (DSC). For a certain urea concentration, the enthalpy change of phase transition of poly(N-isopropylacrylamide) (PNIPAM) aqueous solution increases with the number of DSC cycles, presumably due to the displacement of water molecules bound to the amide groups of PNIPAM by urea molecules at the temperature higher than the lower critical solution temperature (LCST) of PNIPAM and causes the decrease in the absolute value of the exothermic heat related to the dehydration of hydrophilic groups and interactions of hydrophilic residues to around 0. Moreover, the enthalpy change decreases with the urea concentration during the heating process of the first DSC cycle, indicating the replacement of water molecules around the apolar isopropyl groups by urea molecules at the temperature lower than LCST, and the endothermic heat caused by the dehydration of apolar groups decreases. Furthermore, the urea molecules which replace the water molecules at high temperature can be replaced again by water molecules at the temperature lower than LCST, but this process needs several days to complete. PMID:25029067

Gao, Yating; Yang, Jinxian; Ding, Yanwei; Ye, Xiaodong

2014-08-01

134

Differential Scanning Calorimetry and Evolved Gas Analysis at Mars Ambient Conditions Using the Thermal Evolved Gas Analyser (TEGA)  

NASA Technical Reports Server (NTRS)

We are conducting DSC/EGA experiments at Mars ambient temperature and pressure using the TEGA engineering model. These tests illustrate the outstanding capabilities of a TEGA-like instrument on the surface of Mars.

Musselwhite, D. S.; Boynton, W. V.; Ming, D. W.; Quadlander, G. A.; Kerry, K. E.; Bode, R. C.; Bailey, S. H.; Ward, M. G.; Pathare, A. V.; Lorenz, R. D.

2000-01-01

135

Particle Flow Calorimetry at the ILC  

SciTech Connect

One of the most important requirements for a detector at the ILC is good jet energy resolution. It is widely believed that the particle flow approach to calorimetry is the key to achieving the goal of 0.3/{radical}(E(GeV)). In contrast to the traditional approach to calorimetry, potentially the performance of particle flow calorimetry is sensitive to the detailed structure of hadronic showers. This paper describes the current performance of the PANDORAPFA particle flow algorithm. For 45 GeV jets in the Tesla TDR detector concept, the ILC jet energy resolution goal is reached. First detector optimisation studies are presented and the aspects of hadronic showers which are most likely to impact particle flow performance are discussed.

Thomson, M. A. [Cavendish Laboratory, Univ. of Cambridge, JJ Thomson Av., Cambridge CB3 0HE (United Kingdom)

2007-03-19

136

High temperature drop calorimetry and thermodynamic properties  

SciTech Connect

Experimental determination of thermodynamic properties (e.g. enthalpy of formation, heat capacity, Gibbs free energy, etc.) is still the recourse for accurate thermodynamic data for the condensed phases. Calorimetry is probably the best experimental method for their determination. Drop calorimetry in its various modifications is still the method of choice to determine the enthalpy functions for solids and liquids above 1,000 C. The conventional drop calorimeter for solids and a drop calorimeter coupled to an electromagnetic levitation coil useful for conductive samples in both the solid and molten phases are described. Experimental results obtained up to and above the melting point of rare earth metals are presented.

Chandrasekhariah, M.S. [Houston Advanced Research Center, The Woodlands, TX (United States). Materials Science Research Center; Bautista, R.G. [Univ. of Nevada, Reno, NV (United States). Dept. of Chemical and Metallurgical Engineering

1995-04-01

137

Characterisation of paracetamol form III with rapid-heating DSC.  

PubMed

Form III is the most unstable polymorph of paracetamol discovered and has not been fully characterized. Its instability in air means that it must be formed in situ in whichever instrument is used for analysis and even its melting point is the subject of discussion, because it undergoes a solid-solid conversion to form II when heated. The recent development of rapid-heat differential scanning calorimetry (RHDSC), which offers heating rates up to 2000 degrees C/min, provides a new opportunity to characterize unstable polymorphs because of the likelihood that form changes can be inhibited at higher heating rates. Hence the specific aim of this work was to use RHDSC to isolate and characterize paracetamol form III. Form III was prepared from the glass by holding isothermally at 113 degrees C for 2 min. Upon heating at slow scan rates (up to 300 degrees C min(-1)) a solid-solid transition to form II at ca. 120 degrees C was seen, followed by melting of form II at 156 degrees C. At heating rates of 400 degrees C min(-1) and higher, the solid-solid transition was absent and two endotherms were observed; the form II melt at 156 degrees C and a new, lower temperature endotherm at 143 degrees C. We ascribe the transition at 143 degrees C to the melting of form III. The form II melt was present in all experiments, irrespective of heating rate; thus we presume the paracetamol crystallizes to a mixture of forms II and III during preparation, indicative again of the unstable nature of form III. Experiments conducted with a crystal growth modifier (hydroxypropylmethylcellulose, HPMC) showed that increasing the HPMC molecular mass, or increasing the HPMC:paracetamol ratio, resulted in a concomitant increase in the form III peak, relative to the form II peak, which supports the hypothesis that the sample coexisted in both forms prior to crystallization. PMID:20478676

Gaisford, Simon; Buanz, Asma B M; Jethwa, Nadya

2010-11-01

138

Raman scattering boson peak and differential scanning calorimetry studies of the glass transition in tellurium-zinc oxide glasses.  

PubMed

Raman scattering and differential scanning calorimetry (DSC) measurements have been carried out on four mixed tellurium-zinc oxide (TeO(2))(1 - x)(ZnO)(x) (x = 0.1, 0.2, 0.3, 0.4) glasses under variable temperature, with particular attention being given to the respective glass transition region. From the DSC measurements, the glass transition temperature T(g) has been determined for each glass, showing a monotonous decrease of T(g) with increasing ZnO content. The Raman study is focused on the low-frequency band of the glasses, the so-called boson peak (BP), whose frequency undergoes an abrupt decrease at a temperature T(d) very close to the respective T(g) values obtained by DSC. These results show that the BP is highly sensitive to dynamical effects over the glass transition and provides a means for an equally reliable (to DSC) determination of T(g) in tellurite glasses and other network glasses. The discontinuous temperature dependence of the BP frequency at the glass transition, along with the absence of such a behaviour by the high-frequency Raman bands (due to local atomic vibrations), indicates that marked changes of the medium range order (MRO) occur at T(g) and confirms the correlation between the BP and the MRO of glasses. PMID:21386447

Stavrou, E; Tsiantos, C; Tsopouridou, R D; Kripotou, S; Kontos, A G; Raptis, C; Capoen, B; Bouazaoui, M; Turrell, S; Khatir, S

2010-05-19

139

Thermokineticmodel simulations for methyl ethyl ketone peroxide contaminated with H 2 SO 4 OR NaOH by DSC and VSP2  

Microsoft Academic Search

In\\u000a this study, a mixture of methyl ethyl ketone peroxide (MEKPO) with various\\u000a contaminants, such as H2SO4\\u000a and NaOH, was prepared in order to elucidate the cause of these accidents\\u000a and the results of upset conditions. Thermokinetic parameters were acquired\\u000a by both differential scanning calorimetry (DSC) and vent sizing package 2\\u000a (VSP2). In addition, we simulated the thermokinetic parameters and

R. H. Chang; J. M. Tseng; J. M. Jehng; C. M. Shu; H. Y. Hou

2006-01-01

140

Calculation of Temperature Rise in Calorimetry.  

ERIC Educational Resources Information Center

Gives a simple but fuller account of the basis for accurately calculating temperature rise in calorimetry. Points out some misconceptions regarding these calculations. Describes two basic methods, the extrapolation to zero time and the equal area method. Discusses the theoretical basis of each and their underlying assumptions. (CW)

Canagaratna, Sebastian G.; Witt, Jerry

1988-01-01

141

Isothermal Titration Calorimetry in the Student Laboratory  

ERIC Educational Resources Information Center

Isothermal titration calorimetry (ITC) is the measurement of the heat produced by the stepwise addition of one substance to another. It is a common experimental technique, for example, in pharmaceutical science, to measure equilibrium constants and reaction enthalpies. We describe a stirring device and an injection pump that can be used with a…

Wadso, Lars; Li, Yujing; Li, Xi

2011-01-01

142

Benzanilide: on the crossroads of calorimetry, computations and concepts  

NASA Astrophysics Data System (ADS)

The standard (p° = 0.1 MPa) molar enthalpy of formation for solid benzanilide was derived from the standard molar enthalpy of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry, and the standard molar enthalpy of sublimation, at T = 298.15 K, measured by Calvet microcalorimetry. From these experiments the standard molar enthalpy of formation of benzanilide in the gaseous phase at T = 298.15 K was calculated. In addition density functional theory calculations with the B3LYP functional and a variety of basis sets have been performed for benzanilide and some auxiliary molecules.

Matos, M. A. R.; Miranda, M. S.; Morais, V. M. F.; Liebman, J. F.

143

Investigation on chemical cross-linked collagen phosphoric acid hydrolysates with cyanuric chloride by differential scanning calorimetry  

Microsoft Academic Search

The process of cross-linking of collagen phosphoric acid hydrolysates (CH) with cyanuric chloride (CY) was studied by the\\u000a increase in the denaturation temperature using differential scanning calorimetry (DSC). This measurement gave indications\\u000a concerning the efficiency of the treatment, i.e., the extent of cross-linking of the collagen hydrolysates. The optimal conditions\\u000a for cross-linking were determined: CH\\/CY in a ratio 1:1, reaction

I. Chakarska; S. Todinova; K. Idakieva

2010-01-01

144

Stop-and-return DSC method to study fat crystallization  

Microsoft Academic Search

Differential scanning calorimeters have frequently been used to study the isothermal crystallization kinetics of fats and oils. In some circumstances (e.g. start of crystallization during cooling to the crystallization temperature, crystallization in emulsion) this straightforward approach is not applicable. This paper describes an indirect DSC method for determination of the crystallization kinetics under these ‘difficult’ circumstances. The principle is to

Imogen Foubert; Eveline Fredrick; Jeroen Vereecken; Maarten Sichien; Koen Dewettinck

2008-01-01

145

A novel hermetic differential scanning calorimeter (DSC) sample crucible  

Microsoft Academic Search

The design of a novel differential scanning calorimeter (DSC) sample crucible that allows for the analysis of liquid and solid materials (the solids can also be wetted with a liquid) at high temperatures is described. The sample to be analyzed is placed within a thin walled stainless steel tube, which is then sealed by tungsten inert gas (TIG) welding. The

D. D. MacNeil; S. Trussler; H. Fortier; J. R. Dahn

2002-01-01

146

Summary of the Group H Sessions (Calorimetry, muons, masks, ... )  

E-print Network

Summary of the Group H Sessions (Calorimetry, muons, masks, ... ) Ray Frey U. Oregon Dept "How to Test Energy Flow" 35 · Renyuan Zhu, CalTech "Comments on LC Calorimetry'' 25 · Marcello Piccolo calorimeter" 20 · George Bashindzhagyan, Moscow St. U. "Silicon Calorimetry for a Linear Collider" 20 Session

Frey, Raymond E.

147

NISTIR 7267 Low Temperature Calorimetry Studies of Hydrating  

E-print Network

NISTIR 7267 Low Temperature Calorimetry Studies of Hydrating Portland Cement Pastes 0.010 0.015 0 Calorimetry Studies of Hydrating Portland Cement Pastes Dale P. Bentz Materials and Construction Research calorimetry (LTC) scans performed on hydrating portland cement pastes between 2002 and 2005. Because the LTC

Bentz, Dale P.

148

Use of indirect calorimetry in clinical nutrition.  

PubMed

The tremendous variability in resting energy expenditure makes efforts to predict caloric requirements difficult. Indirect calorimetry has provided a valuable tool in assessing energy expenditure, evaluating the way in which the body uses nutrient fuel, and designing nutritional regimens that best fit the clinical condition of the patient. The many indirect calorimetric instruments available vary in their application to clinical nutrition. The best metabolic studies are achieved by controlling the testing environment, accounting for the many clinical factors that may affect measurements, and eliminating potential sources for error. Although indirect calorimetry would seem to reduce the likelihood of complications from overfeeding, its greatest effect may be in cost savings by avoiding unnecessary nutritional support and in providing a means for clinical research. PMID:1289691

McClave, S A; Snider, H L

1992-10-01

149

From Biochemistry to Physiology: The Calorimetry Connection  

Microsoft Academic Search

This article provides guidelines for selecting optimal calorimetric instrumentation for applications in biochemistry and biophysics.\\u000a Applications include determining thermodynamics of interactions in non-covalently bonded structures, and determining function\\u000a through measurements of enzyme kinetics and metabolic rates. Specific examples illustrating current capabilities and methods\\u000a in biological calorimetry are provided. Commercially available calorimeters are categorized by application and by instrument\\u000a characteristics (isothermal

Lee D. Hansen; Donald J. Russell; Christin T. Choma

2007-01-01

150

Vacuum Calorimetry in Exploding Wire Studies  

E-print Network

A method of using vacuum calorimetry as a means of determining directly the energy deposited in an electrically exploded wire is presented. This energy determination is compared with that given by the time integral of the product of voltage and current. A definite reproducible pattern of the explosion products is deposited on the walls of the calorimeter, which may be used as a means of understanding the behavior of the wire during the explosion.

Mario Rabinowitz

2003-07-24

151

Monitoring soybean seed germination by calorimetry  

Microsoft Academic Search

A method to monitor seed germination that combines isothermal calorimetry and imbibition measurements is reported. Individual\\u000a seeds of three cultivars of soybean seeds (A7636RG, Munasqa and DM5.8RR) and one of radish were used. Imbibition curves were\\u000a performed on individual seeds in a germination chamber at 25 °C. Calorimetric specific thermal power (p)–time (t) curves of germination were also obtained at 25 °C

Fanny I. Schabes; E. Elizabeth Sigstad

2011-01-01

152

Performance of Particle Flow Calorimetry at CLIC  

E-print Network

The particle flow approach to calorimetry can provide unprecedented jet energy resolution at a future high energy collider, such as the International Linear Collider (ILC). However, the use of particle flow calorimetry at the proposed multi-TeV Compact Linear Collider (CLIC) poses a number of significant new challenges. At higher jet energies, detector occupancies increase, and it becomes increasingly difficult to resolve energy deposits from individual particles. The experimental conditions at CLIC are also significantly more challenging than those at previous electron-positron colliders, with increased levels of beam-induced backgrounds combined with a bunch spacing of only 0.5 ns. This paper describes the modifications made to the PandoraPFA particle flow algorithm to improve the jet energy reconstruction for jet energies above 250 GeV. It then introduces a combination of timing and p_T cuts that can be applied to reconstructed particles in order to significantly reduce the background. A systematic study is performed to understand the dependence of the jet energy resolution on the jet energy and angle, and the physics performance is assessed via a study of the energy and mass resolution of W and Z particles in the presence of background at CLIC. Finally, the missing transverse momentum resolution is presented, and the fake missing momentum is quantified. The results presented in this paper demonstrate that high granularity particle flow calorimetry leads to a robust and high resolution reconstruction of jet energies and di-jet masses at CLIC.

J. S. Marshall; A. Münnich; M. A. Thomson

2012-09-18

153

Mass fractal characteristics of wet sonogels as determined by small-angle x-ray scattering and differential scanning calorimetry  

SciTech Connect

Low density silica sonogels were prepared from acid sonohydrolysis of tetraethoxysilane. Wet gels were studied by small-angle x-ray scattering (SAXS) and differential scanning calorimetry (DSC). The DSC tests were carried out under a heating rate of 2 deg. C/min from -120 deg. C up to 30 deg. C. Aerogels were obtained by CO{sub 2} supercritical extraction and characterized by nitrogen adsorption and SAXS. The DSC thermogram displays two distinct endothermic peaks. The first, a broad peak extending from about -80 deg. C up to practically 0 deg. C, was associated to the melting of ice nanocrystals with a crystal size distribution with 'pore' diameter ranging from 1 or 2 nm up to about 60 nm, as estimated from Thomson's equation. The second, a sharp peak with onset temperature close to 0 deg. C, was attributed to the melting of macroscopic crystals. The DSC incremental 'nanopore' volume distribution is in reasonable agreement with the incremental pore volume distribution of the aerogel as determined from nitrogen adsorption. No macroporosity was detected by nitrogen adsorption, probably because the adsorption method applies stress on the sample during measurement, leading to a underestimation of pore volume, or because often positive curvature of the solid surface is in aerogels, making the nitrogen condensation more difficult. According to the SAXS results, the solid network of the wet gels behaves as a mass fractal structure with mass fractal dimension D=2.20{+-}0.01 in a characteristic length scale below {xi}=7.9{+-}0.1 nm. The mass fractal characteristics of the wet gels have also been probed from DSC data by means of an earlier applied modeling for generation of a mass fractal from the incremental ''pore'' volume distribution curves. The results are shown to be in interesting agreement with the results from SAXS.

Vollet, D. R.; Donatti, D. A.; Ibanez Ruiz, A.; Gatto, F. R. [Departamento de Fisica, Unesp-Univerisdade Estadual Paulista, IGCE, P.O. Box 178 CEP 13500-970 Rio Claro, SP (Brazil)

2006-07-01

154

Reconsideration of polymorphic transformations in cocoa butter using the DSC  

Microsoft Academic Search

Cocoa butter was crystallized in the differential scanning calorimeter (DSC) in the presence and the absence of sorbitan monostearate\\u000a at different cooling rates. The solidification and fusion curves were recorded. It was found that cooling rate affects enthalpies\\u000a and temperatures of phase transitions. The very slow cooling rate causes a significant decrease in crystallization enthalpy,\\u000a suggesting that fractionation of glycerides

Judith Schlichter Aronhime; Sara Sarig; Nissim Garti

1988-01-01

155

A comparison of different evaluation methods in modulated temperature DSC  

Microsoft Academic Search

Modulated temperature-DSC is a new method for measuring the thermal behaviour of materials. In this method, the response of the sample to a time-dependent signal (sinusoidal temperature change) is measured. Two different methods are known for the evaluation of the measured data. The first is the separation of the measured data into reversing and non-reversing components of heat flow. The

J. E. K. Schawe

1995-01-01

156

Heat capacity measurements by computer-interfaced DSC  

Microsoft Academic Search

A computer assisted heat capacity measuring system has been designed from commercial components. A differential scanning calorimeter of type Perkin-Elmer DSC-2 forms the basis for measurements from 100 to 1000 K. A Hewlett-Packard calculator (minicomputer) of type 9821 is the data handling system. The data are collected and permanently stored on teletape. The program has been written to govern measurement

U. Gaur; A. Mehta; B. Wunderlich

1978-01-01

157

DSC numerical solution of the Oberbeck-Boussinesq equations  

E-print Network

Dual Scattering Channel schemes generalise Johns' TLM algorithm and replace the latter in situations where the transmission line picture of wave propagation fails. This is notoriously the case in applications to fluid dynamics, for instance. In this paper, a DSC numerical solution of the Oberbeck-Boussinesq equations is presented, which approximate the Navier-Stokes equations for viscous quasi incompressible flow with moderate variation in temperature.

Steffen Hein

2005-05-04

158

Protein Unfolding Coupled to Ligand Binding: Differential Scanning Calorimetry Simulation Approach  

NASA Astrophysics Data System (ADS)

The aim of this work is to present the physicochemical basis underlying the changes in protein thermostability upon ligand binding. The article is addressed to advanced undergraduate and postgraduate chemistry students with an interest in protein biophysics. In addition, this article provides a useful tool for both learning and teaching biophysics because it links fundamental concepts: thermodynamics, chemical equilibrium, and protein stability. The influence of protein ligand interactions on thermally-induced protein denaturation was monitored by differential scanning calorimetry (DSC). The changes in DSC output (thermogram) emerge by linking binding equilibrium with reversible protein unfolding thermodynamics. We derive the formalism for the description of protein unfolding in the presence of ligand that can bind to a single site on either native, unfolded, or both protein states. In addition to a rigorous mathematical description of the involved equilibria, the model provides the general formulation for simulating thermograms and calculating the changes in protein species during heating. First, we describe ligand interaction and emphasize the relationship between protein stability parameters and redistribution of species in equilibrium. After that, we describe the origin of bimodal thermograms, and finally, the effect on thermogram shape of protein concentration at constant ligand/protein mole ratio.

Soledad Celej, María; Fidelio, Gerardo Daniel; Dassie, Sergio Alberto

2005-01-01

159

An isothermal titration and differential scanning calorimetry study of the G-quadruplex DNA-insulin interaction.  

PubMed

The binding of insulin to the G-quadruplexes formed by the consensus sequence of the insulin-linked polymorphic region (ILPR) was investigated with differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC). The thermal denaturation temperature of insulin was increased by almost 4 °C upon binding to ILPR G-quadruplex DNA as determined by DSC. The thermodynamic parameters (K(D), ?H, ?G, and ?S) of the insulin-G-quadruplex complex were further investigated by temperature-dependent ITC measurement over the range of 10-37 °C. The binding of insulin to the ILPR consensus sequence displays micromolar affinity in phosphate buffer at pH 7.4, which is mainly driven by entropic factors below 25 °C but by enthalpic terms above 30 °C. The interaction was also examined in several different buffers, and results showed that the observed ?H is dependent on the ionization enthalpy of the buffer used. This indicates proton release upon the binding of G-quadruplex DNA to insulin. Additionally, the large negative change in heat capacity for this interaction may be associated with the dominant hydrophobicity of the amino acid sequence of insulin's ? subunit, which is known to bind to the ILPR G-quadruplex DNA. PMID:24459986

Timmer, Christine M; Michmerhuizen, Nicole L; Witte, Amanda B; Van Winkle, Margaret; Zhou, Dejian; Sinniah, Kumar

2014-02-20

160

Sertaconazole/hydroxypropyl-beta-cyclodextrin complexation: isothermal titration calorimetry and solubility approaches.  

PubMed

Complexation of sertaconazole (SN) with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was characterized by phase-solubility diagram measurements and isothermal calorimetry (ITC) in aqueous medium, and by differential scanning calorimetry (DSC), Raman spectroscopy and X-ray diffractometry in solid state. The strongest interaction was observed at pH 1.2, at which two different 1:1 complexes can be formed depending on the hydrophobic ring of the drug involved in the process. At pH 5.8 and 7.4 the likelihood of 1:2 stoichiometry increases as a consequence of the simultaneous complexation of the nonprotonized imidazolyl and the dichlorophenyl groups. In the presence of 20% HP-beta-CD, SN solubility is enhanced by a factor of 116, 107, and 5 at pH 1.2, 5.8, and 7.4, respectively. Complexation enthalpy recorded by ITC showed the same tendency which confirms the practical interest of this technique for fast screening of the potential of CDs as drug solubilizers. Solubility and dissolution rate of the drug from compacts prepared with freeze-dried complexes were significantly greater than those obtained with SN powder or compacts made with physical blends. PMID:16795015

Rodriguez-Perez, Ana I; Rodriguez-Tenreiro, Carmen; Alvarez-Lorenzo, Carmen; Taboada, Pablo; Concheiro, Angel; Torres-Labandeira, Juan J

2006-08-01

161

Hydroperoxide titration by DSC in thermally oxidized polypropylene  

Microsoft Academic Search

Unstabilized polypropylene (PP) films and stabilized PP fibres were thermally oxidized at 80°C under high oxygen pressure (5.0MPa). Their oxidation was monitored by infrared (IR) spectroscopy, iodometric titration and modulated differential scanning calorimetry (MDSC). This latter technique allows separation of the thermograms into two parts: a reversing signal containing the major part of the melting endotherm and a non-reversing exothermal

E. Richaud; F. Farcas; B. Fayolle; L. Audouin; J. Verdu

2006-01-01

162

Thermal decomposition of some siderite-magnesite minerals using DSC  

Microsoft Academic Search

Members of the siderite-magnesite series of carbonates have been investigated in nitrogen using differential scanning calorimetry. The mineral specimens contained between 0.3–0.95 mole fraction iron. Decomposition temperatures decreased markedly with increasing Fe substitution. Enthalpies of decomposition showed a linear dependence upon the degree of Fe and Fe + Mn substitution. The fit (R2=0.995) in the case of Fe + Mn

J. V. Dubrawski

1991-01-01

163

Hydration and Lyotropic Melting of Amphiphilic Molecules: A Thermodynamic Study Using Humidity Titration Calorimetry  

Microsoft Academic Search

The hydration of the lipid 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) and of the cationic detergent dodecyltrimethylammonium bromide (DTAB) has been studied by means of isothermal titration calorimetry (ITC), gravimetry, and infrared (IR) spectroscopy. During the experiments films of the amphiphiles are perfused by an inert gas of variable relative humidity. The measurement of adsorption heats using ITC represents a new adaptation of adsorption

H. Binder; B. Kohlstrunk; H. H. Heerklotz

1999-01-01

164

DSC studies to evaluate the impact of bio-oil on cold flow properties and oxidation stability of bio-diesel.  

PubMed

This paper describes the use of Differential Scanning Calorimetry (DSC) to evaluate the impact of varying mix ratios of bio-oil (pyrolysis oil) and bio-diesel on the oxidation stability and on some cold flow properties of resulting blends. The bio-oils employed were produced from the semi-continuous Auger pyrolysis of pine pellets and the batch pyrolysis of pine chips. The bio-diesel studied was obtained from poultry fat. The conditions used to prepare the bio-oil/bio-diesel blends as well as some of the fuel properties of these blends are reported. The experimental results suggest that the addition of bio-oil improves the oxidation stability of the resulting blends and modifies the crystallization behavior of unsaturated compounds. Upon the addition of bio-oil an increase in the oxidation onset temperature, as determined by DSC, was observed. The increase in bio-diesel oxidation stability is likely to be due to the presence of hindered phenols abundant in bio-oils. A relatively small reduction in DSC characteristic temperatures which are associated with cold flow properties was also observed but can likely be explained by a dilution effect. PMID:20307976

Garcia-Perez, Manuel; Adams, Thomas T; Goodrum, John W; Das, K C; Geller, Daniel P

2010-08-01

165

Monitoring crystallisation of drugs from fast-dissolving oral films with isothermal calorimetry.  

PubMed

The aim of this study was to evaluate the potential of isothermal calorimetry to monitor and characterize crystallisation in drug-loaded fast-dissolving oral films. Films of polyvinylpyrrolidone (PVP) containing indomethacin were cast into glass ampoules; stability was assessed by monitoring the power changes occurring with time. Three grades of PVP (K10, K25 and K40, where the number multiplied by 1000 gives the average molecular weight) were used. Indomethacin was seen to crystallise from all PVP grades over ca. 24-48 h at two study temperatures (25 and 37 degrees C), as denoted by a large exothermic event. At 25 degrees C the exothermic event was a single peak; at 37 degrees C two peaks were observed. Subsequent analysis of the crystals with differential scanning calorimetry (DSC) and polarized light microscopy determined that the stable gamma-polymorph of indomethacin formed at 25 degrees C while both the gamma- and metastable alpha-polymorphs formed at 37 degrees C. The calorimetric data were converted to relative crystallinity as a function of time and analysed with three crystallisation models (Avrami, Tobin and Urbanovici-Segal) to determine crystallisation kinetics. Of the three models applied the Urbanovici-Segal model best described the data, although this may be because this model contains a term that effectively accounts for deviation from the Avrami model. The rate constants determined were broadly consistent irrespective of the model used. Increasing polymer molecular weight did not generally affect the crystallisation rate, although an increase in temperature did result in a concomitant increase in crystallisation rate. The data suggest that isothermal calorimetry is able to monitor drug crystallisation in polymer films and therefore the technique could be a useful tool for conducting stability assays for fast-dissolving oral medicines. PMID:19596058

Gaisford, Simon; Verma, Amit; Saunders, Mark; Royall, Paul G

2009-10-01

166

REDES DE COMPUTADORES UFPB / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura -Camada de Transporte * Pg. 1  

E-print Network

REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura - Camada de Transporte / DSC / PSN, 2001 * Parte 2: Arquitetura - Camada de Transporte * Pág. 2 ! O nível de transporte, de se usa o serviço com conexão). #12;REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 2

Cirne, Walfredo

167

REDES DE COMPUTADORES UFPB / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura -Camada de Enlace * Pg. 1  

E-print Network

REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura - Camada de Enlace pouco ocupados). REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura - Camada de) Figura 1. (a) Comunicação virtual; (b) Comunicação real #12;REDES DE COMPUTADORES © UFPB / CCT / DSC

Cirne, Walfredo

168

Proceedings of the 3rd International Workshop on Distributed Statistical Computing (DSC 2003)  

E-print Network

Proceedings of the 3rd International Workshop on Distributed Statistical Computing (DSC 2003) March 20­22, Vienna, Austria http://www.ci.tuwien.ac.at/Conferences/DSC-2003/ K. Hornik & F. Leisch (eds these objectives, a great variety of #12;Proceedings of DSC 2003 2 normalization methods were implemented

Rostock, Universität

169

AKADEMIE VD CESK REPUBLIKY Teze disertace k zskn vdeckho titulu "doktora vd" (DSc.)  

E-print Network

AKADEMIE VD CESK� REPUBLIKY Teze disertace k získání vdeckého titulu "doktora vd" (DSc.) ve skupin" (DSc.) in Molecular Biology and Medicine Interakce protein HMGB s DNA a chromatinem Interactions biologie Committee for the defense of DSc. thesis in Molecular Biology RNDr. Michal Stros, CSc

Tebbens, Jurjen Duintjer

170

J. Symbolic Computation (1995) 19, 269282 Process Scheduling in DSC and the Large Sparse  

E-print Network

J. Symbolic Computation (1995) 19, 269­282 Process Scheduling in DSC and the Large Sparse Linear,hitzm,kaltofen,loboa}@cs.rpi.edu; tomv@tiger.hsc.edu (Received 15 March 1995) New features of our DSC system for distributing a symbolic in about 54 hours CPU time. 1. Introduction In D´iaz et al., (1991) we introduced our DSC system

Kaltofen, Erich

171

Invited Paper A New Microstructured DSC Photoelectrode for Potential High Power  

E-print Network

Invited Paper A New Microstructured DSC Photoelectrode for Potential High Power Conversion approaches and efforts to enhance the power conversion efficiency in dye-sensitized solar cells (DSC) and then the recent development of hierarchically structured photoelectrodes for DSC. Hierarchically structured

Cao, Guozhong

172

DSC 2001 Proceedings of the 2nd International Workshop on Distributed Statistical Computing  

E-print Network

DSC 2001 Proceedings of the 2nd International Workshop on Distributed Statistical Computing March 15-17, Vienna, Austria http://www.ci.tuwien.ac.at/Conferences/DSC-2001 RGL: An R Interface to Open; Proceedings of DSC 2001 2 1.1 OpenGL OpenGL is a complex library. There is support for drawing 3 dimensional

Murdoch, Duncan

173

Kinetics of the Thermal Degradation of Erica Arborea by DSC: Hybrid Kinetic Method D. Cancellieri*  

E-print Network

1 Kinetics of the Thermal Degradation of Erica Arborea by DSC: Hybrid Kinetic Method D. Cancellieri. DSC and TGA were used in this study under air sweeping to record oxidative reactions. Two dominating and overlapped exothermic peaks were recorded in DSC and individualized using a experimental and numerical

Paris-Sud XI, Université de

174

REDES DE COMPUTADORES UFPB / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura -Camada Fsica * Pg. 1  

E-print Network

REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura - Camada Física * Pág / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura - Camada Física * Pág. 2 ! sinal analógico: sinal que amplitude, freqüência e fase #12;REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura

Cirne, Walfredo

175

Fifteen years after DSC and WLSS2 What parallel computations I do today  

E-print Network

Fifteen years after DSC and WLSS2 What parallel computations I do today Erich L. Kaltofen North as mentioned above. ... Erich 6 #12;Distributed Symbolic Computation (DSC) Tool [Diaz, Kaltofen, Schmitz'n2Stat'n1 Partask2 Partask1.c Partask1.i Partask1.d Stat'n0 Server Server Server 7 #12;DSC Predictive

Kaltofen, Erich

176

REDES DE COMPUTADORES UFPB / CCT / DSC / PSN, 2001 * Parte 3: TCP/IP -Endereamento * Pg. 1  

E-print Network

REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 3: TCP/IP - Endereçamento * Pág. 1 . 165 . 166 . 0 200 . 201 . 203 . 255 REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 3 ! Observa-se que alguns endereços são reservados. #12;REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001

Cirne, Walfredo

177

REDES DE COMPUTADORES UFPB / CCT / DSC / PSN, 2001 * Parte 4: Estudo de Caso -UFPB * Pg. 1  

E-print Network

REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 4: Estudo de Caso - UFPB * Pág. 1 3 COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 4: Estudo de Caso - UFPB * Pág. 2 Alguns dados gerais ATM ligações redundantes entre as regiões do DEC, DEE e DSC ! Campus III, IV, V, VI, VII

Cirne, Walfredo

178

Thermal hazard analysis for cumene hydroperoxide by DSC and TAM Tsu-Kaung Miao1  

E-print Network

1 Thermal hazard analysis for cumene hydroperoxide by DSC and TAM Tsu- Kaung Miao1 , Chi-Min Shu1 or damage can be alleviated by analyzing the specific chemical with adequate instruments, such as DSC be controlled or mitigated under an acceptable level. This study compared both DSC and TAM to test

Chen, Shu-Ching

179

REDES DE COMPUTADORES UFPB / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura -Camada de Aplicao * Pg. 1  

E-print Network

REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura - Camada de Aplicação mostra alguns [poucos] exemplos. REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 2 ilícitos. #12;REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 2: Arquitetura - Camada de

Cirne, Walfredo

180

Investigation of MSWI fly ash melting characteristic by DSC-DTA  

SciTech Connect

The melting process of MSWI (Municipal Solid Waste Incineration) fly ash has been studied by high-temperature DSC-DTA experiments. The experiments were performed at a temperature range of 20-1450 deg. C, and the considerable variables included atmosphere (O{sub 2} and N{sub 2}), heating rates (5 deg. C/min, 10 deg. C/min, 20 deg. C/min) and CaO addition. Three main transitions were observed during the melting process of fly ash: dehydration, polymorphic transition and fusion, occurring in the temperature range of 100-200 deg. C, 480-670 deg. C and 1101-1244 deg. C, respectively. The apparent heat capacity and heat requirement for melting of MSWI fly ash were obtained by DSC (Differential Scanning Calorimeter). A thermodynamic modeling to predict the heat requirements for melting process has been presented, and it agrees well with the experimental data. Finally, a zero-order kinetic model of fly ash melting transition was established. The apparent activation energy of MSWI fly ash melting transition was obtained.

Li, Rundong [Institute of Clean Energy and Environmental Engineering, Liaoning Key Laboratory of Clean Energy, Shenyang Institute of Aeronautical Engineering, Shenyang 110136 (China)], E-mail: leerd@mail.tsinghua.edu.cn; Wang, Lei; Yang, Tianhua; Raninger, Bernhard [Institute of Clean Energy and Environmental Engineering, Liaoning Key Laboratory of Clean Energy, Shenyang Institute of Aeronautical Engineering, Shenyang 110136 (China)

2007-07-01

181

Thermal properties and optimization of process parameters for the growth of silver thiogallate crystal by differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

In present work, thermal properties of silver thiogallate (AgGaS2) crystal were investigated by means of differential scanning calorimetry (DSC) measurements performed at different heating and cooling rates. The DSC results confirmed that the melting point was 1249 K with a slight change around 5 K and that the nucleation temperature varied from 1183 K to 1218 K. The supercooling temperature was evaluated in the range 37.69 K to 62.46 K which was considered to be harmful for the single nucleus formation at the beginning of crystal growth. The activation energy E and the pre-exponential factor A were also calculated using different isoconversional methods, namely Kissinger-Akahira-Sunose (KAS) method and Flynn-Wall-Ozawa (FWO) method, and the results showed good agreement with each other. According to the results of DSC, a larger temperature gradient up to 30 K/cm was utilized to suppress the formation and growth of multi nuclei and a rapid cooling rate 25 K/min was applied to minimize the second-phase precipitates during the process of crystal growth. Finally, an integral and transparent AgGaS2 single crystal with diameter of 22 mm and the length of 55 mm was obtained.

He, Zhiyu; Zhao, Beijun; Zhu, Shifu; Chen, Baojun; Huang, Wei

2014-09-01

182

Thermal characterization of Titan's tholins by simultaneous TG-MS, DTA, DSC analysis  

NASA Astrophysics Data System (ADS)

Three samples of Titan's tholins synthesized in laboratory under simulated Titan's conditions and presenting different degrees of exposure to ambient atmosphere have been used to study in detail their thermal behavior using thermogravimetry coupled with a mass spectrometer (TG-MS), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). The degradation of Titan's tholins under inert atmosphere follows a three-step consecutive decomposition: a drying stage (>150 °C) where moisture is desorbed, this stage indicated the high hydrophilicity of the tholins; a second stage, the main pyrolysis stage (150-575 °C) where endothermic decomposition begins releasing mainly ammonia, HCN, acetonitrile, and methane over a broad temperature range. Few other hydrocarbon fragments such as ethylene and propane are released but no cyclic molecules, aliphatic or aromatic, are observed. The last stage (>575 °C) is the carbonization of the material leading to a non-crystalline graphitic residue. The thermal degradation under oxygen atmosphere shows the same stages as in argon, with a shift of the thermogravimetric peaks toward lower temperatures indicating a lower thermal stability. The last stage in this case is an oxidative combustion of the char residue. This research concludes that even if Titan tholins, subjected to air contamination for few minutes to several years (varying with the storage conditions) transform to produce different C/N and C/O ratios and thermal stabilities, they undergo the same thermal degradation phases and products. This suggests that the studied three tholins have a similar main chemical structure which does not alter by the air exposure. We discuss on the possible nature of this structure.

Nna-Mvondo, Delphine; de la Fuente, José L.; Ruiz-Bermejo, Marta; Khare, Bishun; McKay, Christopher P.

2013-09-01

183

Differential scanning calorimetry study of ordinary Portland cement  

Microsoft Academic Search

The present work involves using differential scanning calorimeter (DSC) in an investigation of the thermal behaviour of hydration products in ordinary Portland cement as a function of age. The two-step loss of water from calcium silicate hydrate, dehydroxylation of calcium hydroxide, and decarbonation of calcium carbonate contribute respectively to the three major endothermic peaks in the DSC curves. Peaks due

W. Sha; E. A. O'Neill; Z. Guo

1999-01-01

184

Analytic heuristics for a fast DSC-MRI  

NASA Astrophysics Data System (ADS)

Hemodynamics of the human brain may be studied with Dynamic Susceptibility Contrast MRI (DSC-MRI) imaging. The sequence of volumes obtained exhibits a strong spatiotemporal correlation, that can be exploited to predict which measurements will bring mostly the new information contained in the next frames. In general, the sampling speed is an important issue in many applications of the MRI, so that the focus of many current researches is to study methods to reduce the number of measurement samples needed for each frame without degrading the image quality. For the DSC-MRI, the frequency under-sampling of single frame can be exploited to make more frequent space or time acquisitions, thus increasing the time resolution and allowing the analysis of fast dynamics not yet observed. Generally (and also for MRI), the recovery of sparse signals has been achieved by Compressed Sensing (CS) techniques, which are based on statistical properties rather than deterministic ones.. By studying analytically the compound Fourier+Wavelet transform, involved in the processes of reconstruction and sparsification of MR images, we propose a deterministic technique for a rapid-MRI, exploiting the relations between the wavelet sparse representation of the recovered and the frequency samples. We give results on real images and on artificial phantoms with added noise, showing the superiority of the methods both with respect to classical Iterative Hard Thresholding (IHT) and to Location Constraint Approximate Message Passing (LCAMP) reconstruction algorithms.

Virgulin, M.; Castellaro, M.; Marcuzzi, F.; Grisan, E.

2014-03-01

185

Study on biodegradation process of lignin by FTIR and DSC.  

PubMed

The biodegradation process of lignin by Penicillium simplicissimum was studied to reveal the lignin biodegradation mechanisms. The biodegradation products of lignin were detected using Fourier transform infrared spectroscopy (FTIR), UV-Vis spectrophotometer, different scanning calorimeter (DSC), and stereoscopic microscope. The analysis of FTIR spectrum showed the cleavage of various ether linkages (1,365 and 1,110 cm(-1)), oxidation, and demethylation (2,847 cm(-1)) by comparing the different peak values in the corresponding curve of each sample. Moreover, the differences (Tm and ?Hm values) between the DSC curves indirectly verified the FTIR analysis of biodegradation process. In addition, the effects of adding hydrogen peroxide (H2O2) to lignin biodegradation process were analyzed, which indicated that H2O2 could accelerate the secretion of the MnP and LiP and improve the enzymes activity. What is more, lignin peroxidase and manganese peroxidase catalyzed the lignin degradation effectively only when H2O2 was presented. PMID:25037100

Liu, Yang; Hu, Tianjue; Wu, Zhengping; Zeng, Guangming; Huang, Danlian; Shen, Ying; He, Xiaoxiao; Lai, Mingyong; He, Yibin

2014-12-01

186

Profiles in Leadership: Clifton J. Latiolais, MSc, DSc  

PubMed Central

The Director’s Forum series is designed to guide pharmacy leaders in establishing patient-centered services in hospitals and health systems. August 2013 marks the 50th anniversary of the publication of the Mirror to Hospital Pharmacy, which was a comprehensive study of pharmacy services in the United States. The late Clifton J. Latiolais, MS, DSc, served as the assistant program director for the study and was a co-author of the Mirror. The late Don E. Francke, MS, DSc, was the lead author of the Mirror and the principal investigator of the federally funded study that reviewed hospital pharmacy services across the United States. The next 2 articles in Director’s Forum profile the leadership of Drs. Latiolais and Francke. This article highlights Dr. Latiolais (“Clif”) by briefly reviewing his biography and key career accomplishments, describing his leadership philosophy, and translating that philosophy to today’s health care challenges. Clif’s influence on health system pharmacy serves as an example of effective leadership. This historical perspective on Clif’s leadership, as seen through the eyes of those who knew him, provides directors of pharmacy a valuable leadership viewpoint as they develop strategies to enhance patient-centered pharmacy services. PMID:24421540

White, Sara; Godwin, Harold N.; Weber, Robert J.

2013-01-01

187

Heat capacity measurement by modulated DSC at constant temperature  

Microsoft Academic Search

The mathematical equations for step-wise measurement of heat capacity (C\\u000a \\u000a p\\u000a ) by modulated differential scanning calorimetry (MDSC) are discussed for the conditions of negligible temperature gradients\\u000a within sample and reference. Using a commercial MDSC, applications are evaluated and the limits explored. This new technique\\u000a permits the determination ofC\\u000a \\u000a p\\u000a by keeping the sample continually close to equilibrium, a condition

A. Boller; Y. Jin; B. Wunderlich

1994-01-01

188

Naphthalene and Azulene I: Semimicro Bomb Calorimetry and Quantum Mechanical Calculations  

NASA Astrophysics Data System (ADS)

A novel H2O physical chemistry experiment is proposed in which the heats of combustion of naphthalene and azulene are measured using bomb calorimetry, and then the energy difference between the two molecules is computed using Gaussian 94W. Azulene is an expensive hydrocarbon ($100/gram); semimicro bomb calorimetry using the Parr 1425 makes the experiment possible using just 0.1 grams of azulene. The experimental difference obtained by students using this apparatus was -34 kcal/mole (azulene - naphthalene); the literature value is -32 kcal/mole. Using the B3LYP/6-31G(D)//RHF/6-31G(D) level of theory we compute an energy difference of -32 kcal/mole; the literature value for the gas-phase energy difference between azulene and naphthalene is -35±2 kcal/mole. Thus this experiment demonstrates that excellent agreement can be obtained between experiment and modern methods of computational chemistry.

Salter, Carl; Foresman, James B.

1998-10-01

189

Calorimetry At Very High Energy Colliders  

SciTech Connect

The capability of hadron colliders has increased to where it will soon be possible to collide protons at center of mass energies of 14 TeV with the advent of the LHC. With increasing collision energy, calorimeters become ever more essential components of a detector, and collaborations often choose very different technologies to meet their goals. From the perspective of a high energy particle and nuclear physicist, a survey is presented of the differences in design considerations and actual performance of the wide variety of calorimeters used in modern hadron colliders such as the Tevatron, RHIC, and LHC. The lessons learned and some ideas for future development of calorimetry will also be discussed.

Chiu, Mickey [Brookhaven National Laboratory, Upton NY 11973 (United States)

2011-06-01

190

Particle Flow Calorimetry for the ILC  

NASA Astrophysics Data System (ADS)

The Particle Flow approach to detector design is seen as the best way to achieve dijet mass resolutions suitable for the precision measurements anticipated at a future e^+e^- Linear Collider (LC). Particle Flow Algorithms (PFAs) affect not only the way data is analyzed, but are necessary and crucial elements used even in initial stages of detector design. In particular, the Calorimeter design parameters are almost entirely dependent on the optimized performance of the PFA. Use of PFAs imposes constraints on the granularity and segmentation of the readout cells, the choices of absorber and active media, and overall detector parameters such as the strength of the B-field, magnet bore, hermeticity, etc. PFAs must be flexible and modular in order to evaluate many detector models in simulation. The influence of PFA development on calorimetry is presented here with particular emphasis on results from the use of PFAs on several LC detector models.

Magill, Stephen

2006-04-01

191

Imaging hadron calorimetry for future Lepton Colliders  

NASA Astrophysics Data System (ADS)

To fully exploit the physics potential of a future Lepton Collider requires detectors with unprecedented jet energy and dijet-mass resolution. To meet these challenges, detectors optimized for the application of Particle Flow Algorithms (PFAs) are being designed and developed. The application of PFAs, in turn, requires calorimeters with very fine segmentation of the readout, so-called imaging calorimeters. This talk reviews progress in imaging hadron calorimetry as it is being developed for implementation in a detector at a future Lepton Collider. Recent results from the large prototypes built by the CALICE Collaboration, such as the Scintillator Analog Hadron Calorimeter (AHCAL) and the Digital Hadron Calorimeters (DHCAL and SDHCAL) are being presented. In addition, various R&D efforts beyond the present prototypes are being discussed.

Repond, José

2013-12-01

192

Calorimetry for Fast Authentication of Edible Oils  

NASA Astrophysics Data System (ADS)

There are little data in the literature on how to authenticate edible oils through calorimetry techniques. However, oil melting curves can be used to represent correlations between calorimetric results and oil quality. A calorimetric method has been developed for studying the solid-liquid phase transitions of olive oil and seed oils, in which melting peak behavior is correlated to the type, quality, and composition of the oil. Good reproducible thermograms were obtained by defining precise protocols for use in testing, which take into account the specific characteristics of a particular oil. This approach does not replace classical analytical methods; nevertheless, it is believed that calorimetric tests could be a useful preliminary stage for quality testing. The calorimetric technique allows the detection of the adulterant (seed oils or refined olive oil), oil origin, and possible photo-oxidation degradation processes, before more complex and expensive procedures and analyses are applied.

Angiuli, Marco; Bussolino, Gian Carlo; Ferrari, Carlo; Matteoli, Enrico; Righetti, Maria Cristina; Salvetti, Giuseppe; Tombari, Elpidio

2009-06-01

193

Synergies between electromagnetic calorimetry and PET  

SciTech Connect

The instrumentation used for the nuclear medical imaging technique of Positron Emission Tomography (PET) shares many features with the instrumentation used for electromagnetic calorimetry. Both fields can certainly benefit from technical advances in many common areas, and this paper discusses both the commonalties and the differences between the instrumentation needs for the two fields. The overall aim is to identify where synergistic development opportunities exist. While such opportunities exist in inorganic scintillators, photodetectors, amplification and readout electronics, and high-speed computing, it is important to recognize that while the requirements of the two fields are similar, they are not identical, and so it is unlikely that advances specific to one field can be transferred without modification to the other.

Moses, William W.

2002-07-30

194

A study of the aging of silicone breast implants using 29Si, 1H relaxation and DSC measurements.  

PubMed

In this study 26 previously implanted silicone breast implants from the same manufacturer (Dow Corning) were investigated with two different analytical methods to characterize potential aging processes such as migration of monomer material from the gel and shell to local and distant sites, chemical alterations of the polymer, and infiltration of body compounds such as lipids. (1)H and (29)Si NMR relaxation measurements (spin-lattice, T1, and spin-spin, T2, relaxation times) were used to study the molecular dynamics of polysiloxane chains, both in gels and in shells. In addition, changes in physical properties were monitored by differential scanning calorimetry (DSC). The results of these measurements indicate that NMR relaxation times are influenced by implant generation, implantation time, shell texture and implant status. (1)H T2 values of shells and gels show a tendency to increase with increasing implantation time, indicating higher mobility and possible disintegration of the polymer network of older implants. Furthermore, the data suggest that aging also involves the migration of low cyclic molecular weight (LMW) silicone and linear chain polymer material from the gels into the shells. The high "bleeding" rate of second-generation (G2) implants (implantation period around 1973-1985), exhibiting thin shells is reflected in reduced relaxation times of these devices, most likely due to a loss of low molecular weight fractions from the gels. Moreover, "gel bleeding" also influences the melting behavior observed in DSC studies. Increased shell rigidity (high Tm and Tg) tends to be correlated with longer (29)Si relaxation times of the corresponding gels, suggesting a reduced transfer of LMW silicones and linear chain polymer from the gel to the shell and to the outside. Remarkably, textured implants seem to be less susceptible to degradation processes than implants with thin shells. PMID:15046931

Birkefeld, Anja Britta; Eckert, Hellmut; Pfleiderer, Bettina

2004-08-01

195

Automatic twin vessel recrystallizer. Effective purification of acetaminophen by successive automatic recrystallization and absolute determination of purity by DSC.  

PubMed

I describe an interchangeable twin vessel (J, N) automatic glass recrystallizer that eliminates the time-consuming recovery and recycling of crystals for repeated recrystallization. The sample goes in the dissolution vessel J containing a magnetic stir-bar K; J is clamped to the upper joint H of recrystallizer body D. Empty crystallization vessel N is clamped to the lower joint M. Pure solvent is delivered to the dissolution vessel and the crystallization vessel via the head of the condenser A. Crystallization vessel is heated (P). The dissolution reservoir is stirred and heated by the solvent vapor (F). Continuous outflow of filtrate E out of J keeps N at a stable boiling temperature. This results in efficient dissolution, evaporation and separation of pure crystals Q. Pure solvent in the dissolution reservoir is recovered by suction. Empty dissolution and crystallization vessels are detached. Stirrer magnet is transferred to the crystallization vessel and the role of the vessels are then reversed. Evacuating mother liquor out of the upper twin vessel, the apparatus unit is ready for the next automatic recrystallization by refilling twin vessels with pure solvent. We show successive automatic recrystallization of acetaminophen from diethyl ether obtaining acetaminophen of higher melting temperatures than USP and JP reference standards by 8× automatic recrystallization, 96% yield at each stage. Also, I demonstrate a novel approach to the determination of absolute purity by combining the successive automatic recrystallization with differential scanning calorimetry (DSC) measurement requiring no reference standards. This involves the measurement of the criterial melting temperature T(0) corresponding to the 100% pure material and quantitative ?T in DSC based on the van't Hoff law of melting point depression. The purity of six commercial acetaminophen samples and reference standards and an eight times recrystallized product evaluated were 98.8 mol%, 97.9 mol%, 99.1 mol%, 98.3 mol%, 98.4 mol%, 98.5 mol% and 99.3 mol% respectively. PMID:21168556

Nara, Osamu

2011-01-24

196

The enthalpy of transformation of Ca(OH)2-I (portlandite) to Ca(OH)2-II (EuI2 structure) by low-temperature DSC  

NASA Astrophysics Data System (ADS)

Thermodynamic properties of high-pressure minerals that are not recoverable from synthesis experiments by conventional quenching methods (``unquenchable'' phases) usually are calculated from equation of state data and phase diagram topologies. The present study shows that, with cryogenic methods of recovery and sample treatment, phases with a suitable decomposition rate can be made accessible to direct thermodynamic measurements. A set of samples of Ca(OH)2-II has been synthesized in a multianvil device and subsequently recovered by cooling the high-pressure assembly with liquid nitrogen. Upon heating from liquid nitrogen to room temperature, the material transformed back to Ca(OH)2-I. The heat effect of this backtransformation was measured by differential scanning calorimetry. A commercial differential scanning calorimeter (Netzsch DSC 404), modified to allow sample loading at liquid nitrogen temperature was used to heat the material from -150 to +200°C at rates varying between 5 and 15°Cmin-1. The transformation started around -50°C very gradually, and peaked at about 0°C. To obtain a baseline correction, each sample was scanned under exactly the same conditions after the backtransformation was complete. Because of the relative sluggishness, onset and offset temperatures were not well defined as compared to fast (e.g., melting) reactions. To aid in integration, the resulting signals were successfully fitted using a generic asymmetric peak model. The enthalpy of backtransformation was determined to be ?H=-10.37+/-0.50kJ mol-1. From previous in situ X-ray diffraction experiments, the location of the direct transformation in P-T space has been constrained to 5.7+/-0.4GPa at 500°C (Kunz etal. 1996). With the reaction volume known from the same study, and assuming that ?Cp of the transformation remains negligible between the conditions of our measurements and 500°C, our result gives an estimate of the entropy of transition and the P-T slope of the reaction curve. To a first approximation, the values ?S=-16.00+/-0.65 J(mol.K)-1 and dP/dT=0.0040+/-0.0002GPa/K have been determined. These results need to be refined by equation of state data for Ca(OH)2-II.

Schoenitz, M.; Navrotsky, A.; Leinenweber, K.

197

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

198

Quantification of polymorphic impurity in an enantiotropic polymorph system using differential scanning calorimetry, X-ray powder diffraction and Raman spectroscopy.  

PubMed

The ability to detect and quantify polymorphism of pharmaceuticals is critically important in ensuring that the formulated product delivers the desired therapeutic properties because different polymorphic forms of a drug exhibit different solubilities, stabilities and bioavailabilities. The purpose of this study is to develop an effective method for quantitative analysis of a small amount of one polymorph within a binary polymorphic mixture. Sulfamerazine (SMZ), an antibacterial drug, was chosen as the model compound. The effectiveness and accuracy of powder X-ray diffraction (PXRD), Raman microscopy and differential scanning calorimetry (DSC) for the quantification of SMZ polymorphs were studied and compared. Low heating rate in DSC allowed complete transformation from Form I to Form II to take place, resulting in a highly linear calibration curve. Our results showed that DSC and PXRD are capable in providing accurate measurement of polymorphic content in the SMZ binary mixtures while Raman is the least accurate technique for the system studied. DSC provides a rapid and accurate method for offline quantification of SMZ polymorphs, and PXRD provides a non-destructive, non-contact analysis. PMID:21645601

Li, Yi; Chow, Pui Shan; Tan, Reginald B H

2011-08-30

199

TG-DSC-FTIR Analysis of Cyanobacteria Pyrolysis  

NASA Astrophysics Data System (ADS)

Pyrolysis of cyanobacteria from Dianchi lake was investigated by TG-DSC-FTIR analysis at different heating rates (10, 20, 40°C/min). The results indicated that the pyrolysis of cyanobacteria can be divided into four stages: evaporation, depolymerization, devolatilization and carbonization. Meanwhile, the initial weight-loss temperature, weight-loss extreme position, endothermic and exothermic peaks were moved to higher temperature with the increaseing of the heating rate. The kinetic analysis was made with Popescu method. It indicated that the best kinetic model for the pyrolysis of cyanobacteria was the cylindrical symmetry of the phase boundary reaction model. The main pyrolysis gases checked with real-time online FTIR were HCN, NH3, CO, CO2, water vapor and hydrocarbons.

Supeng, Luo; Guirong, Bao; Hua, Wang; Fashe, Li; Yizhe, Li

200

Melting vs solidification of a pure metal analyzed by DSC  

SciTech Connect

The aim of the present paper is to analyze the melting/solidification of pure metals resulting from non-equilibrium conditions. Attention is focused on the direct measurement of the calorimetric signal obtained under isothermal hold of the sample at a temperature close to the equilibrium melting temperature T{sub m}, which results in both melting of an overheated solid and solidification of an undercooled melt. The non-equilibrium transformations are monitored by DSC under isothermal regime, with previous continuous heating/continuous cooling of the sample. The dependence of the calorimetric signal on thermodynamic factors, {Delta}H and {Delta}G, is explored. Here {Delta}H and {Delta}G are, respectively, the melting enthalpy and Gibbs free energy difference between the crystal and the liquid. IN particular, the results of the investigation performed on the melting/solidification behavior of pure In and Pb are presented.

Clavaguera, N. [Univ. de Barcelona (Spain); Clavagera-Mora, M.T.; Fontan, J.; Touron, J.L.; Comas, C. [Univ. Autonoma de Barcelona, Bellaterra (Spain). Dept. de Fisica

1998-12-31

201

DSC melting behavior of irradiated low density polyethylenes containing antioxidants  

NASA Astrophysics Data System (ADS)

The effect of antioxidants (0.5 wt% content) on the melting behaviour of low density polyethylenes, one branched and one linear, was examined with data obtained by DSC. The two polyethylenes exhibit noticeable differences in pure form; LLDPE has a higher melting point, lower heat of fusion and a more complex fusion endotherm than LDPE. The addition of antioxidants has a scarcely noticeable influence on the melting behaviour of LDPE whether irradiated or not, while in the case of LLDPE the effect is more visible. However, a careful analysis of the observed characteristics, peak temperatures and lamellae thickness distribution as well as heat of fusion, show that the observed effects are appearing as the consequence of chemical processes, scission and crosslinking, which occur in PE under either thermomechanical action (mixing in the course of the sample preparation), or radiation.

Gal, O.; Kostoski, D.; Babi?, D.; Stannett, V. T.

202

Imperial College London, Academic Regulations 2010/11 Regulations for the Award of the Doctor of Science (DSc) Degree  

E-print Network

of Science (DSc) Degree 1 General Information A DSc (Higher Doctorate) is awarded only for published work for a DSc must either: (a) have previously obtained a degree through Imperial College1 or (b) be of not less for a DSc will be accepted from a person who is a candidate for a comparable award of another institution. 2

Rosso, Lula

203

Quantifying Natural Organic Matter with Calorimetry - assessing system complexity to build a central view C stability  

NASA Astrophysics Data System (ADS)

Characterizing the status and stability of natural organic matter (NOM) is central to understanding the flux, attenuation and function of C in the biosphere. A diversity of stabilizing factors (climate, mineralogy, chemical recalcitrance) have required a range of analytical approaches and methods that are site or discipline specific making unified assessments difficult. Aggregated, these efforts support our working models of NOM as a dynamic body but, overall, lack analytical simplicity and reproducibility. In particular, the robustness and resolution to assess NOM across systems of increasing complexity is lacking. Calorimetry has been central to chemistry and material science characterizing a broad range of organic and inorganic materials and their mixtures illustrating composition, purity and stability. Differential scanning calorimetry - thermogravimetry (DSC-TG) provides the flexibility and resolution to quantify the complexity found within NOM with precise quantification of material mass loss (TG) and energetic (DSC) under controlled atmospheric and heating conditions. DSC-TG is data rich providing a range of qualitative and quantitative metrics: peak shape, exothermic energy yield, mass loss, and determination of enthalpy, to characterize NOM stability from low (dissolved organic carbon - DOC) through high (compost and soils) molecular weights (MW) at increasing levels of organo-metallic complexity. Our research investigates the influence of biochemical recalcitrance and its alteration by oxides employing three natural systems of varying complexity as experimental models: aquatic - DOC and DOC with metal flocculants (low MW - low complexity), compost - processed with and without metal oxides (mixed MW - increasing complexity) and forest soils - under varying management and litter inputs (mixed MW - most complexity). Samples were analyzed by DSC-TG (zero-air - 20 C/min - ambient to > 800C) and assessed for three temperature/exothermic reaction regions (200-350 C - nominally ‘labile’/low MW, 350-500 C - increasing recalcitrance/MW and 500-650 C - recalcitrant/high MW). Samples from all three systems show similar stability distributions with broader less resolved peaks for DOC and soil with intense more resolved peaks for mature compost. DOC flocculated with Iron (Fe) or aluminum (Al) broadened and shifted peak stability to higher temps doubling energy yield compared to DOC (least complex most change). Fe and Al oxides added during composting broadened peaks with shifts towards higher temps with more modest increases in energetic yield(increased complexity reduced change). Soils illustrate a broad and balanced distribution that is fairly robust to treatment or input (most complex least change). Generally metal oxides increased thermal stability and system complexity altering stability distributions towards the diverse and complex soil system. Is the complex and attenuating nature of soil the benchmark to quantify less stable and complex systems based on their components, alterations and metrics of thermal stability and order? Our research is an initial test of this idea supported by reproducible thermal metrics to assess the attenuation of C through natural systems.

Liles, G. C.; Bower, J.; Henneberry, Y.; Horwath, W. R.

2010-12-01

204

DSC and microscopic investigations on HOBACPC S. C. Jain (*) and J. Wahl  

E-print Network

L-201 DSC and microscopic investigations on HOBACPC S. C. Jain (*) and J. Wahl Physikalisches decembre, uccepte le 10 janvier 1983) Résumé. 2014 Nous présentons des études calorimétriques (DSC'aide des études en DSC nous avons mis en évidence l'existence de deux phases solide-cristallines (SC) dans

Paris-Sud XI, Université de

205

REDES DE COMPUTADORES UFPB / CCT / DSC / PSN, 2001 * Parte 3: TCP/IP -Introduo * Pg. 1  

E-print Network

REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 3: TCP/IP - Introdução * Pág. 1 + MILNET REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 3: TCP/IP - Introdução * Pág. 2 ! TCP / DSC / PSN, 2001 * Parte 3: TCP/IP - Introdução * Pág. 3 CARACTERÍSTICAS ! Padrão de protocolos aberto

Cirne, Walfredo

206

Calorimetry for Lepton Collider Experiments - CALICE results and activities  

E-print Network

The CALICE collaboration conducts calorimeter R&D for highly granular calorimeters, mainly for their application in detectors for a future lepton collider at the TeV scale. The activities ranges from generic R&D with small devices up to extensive beam tests with prototypes comprising up to several 100000 calorimeter cells. CALICE has validated the performance of particle flow algorithms with test beam data and delivers the proof of principle that highly granular calorimeters can be built, operated and understood. The successes achieved in the past years allows the step from prototypes to calorimeter systems for particle physics detectors to be addressed.

The CALICE Collaboration

2012-12-20

207

Fourier transform infrared spectroscopy and differential scanning calorimetry studies of fatty acid homogeneous ceramide 2.  

PubMed

Ceramides provide a major component of the barrier function of skin. An understanding of barrier organization requires a detailed characterization of ceramide phase behavior and molecular interactions. Toward this end, Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC) studies of ceramide 2 analogues (non-hydroxylated fatty acid N-acyl sphingosines) of specific chain lengths (C(14), C(16), C(18), C(20)) are presented. In addition, the molecular interactions of the individual chains in each molecule are elucidated through thermotropic FTIR studies of derivatives possessing perdeuterated fatty acid chains. DSC data showed a much smaller chain length variation (for the C(16), C(18), C(20) derivatives) in the main order-disorder transition temperature (approx. 93+/-1 degrees C) than is observed in the corresponding series of phosphatidylcholines, consistent with minimal ceramide hydration. The temperature dependence of the methylene stretching and scissoring modes revealed a solid-solid phase transition at 20-25 degrees C below the main order-disorder transition accompanied by chain packing alterations from orthorhombic-->hexagonal subcells. The chain packing transition was accompanied by enhanced penetration of water into the polar region. This was deduced from the temperature dependence of the amide I and II modes, which provide direct evidence for H-->D exchange. The CD(2) scissoring mode splitting of the deuterated fatty acid constituent of the C(16), C(18), C(20) chains revealed preferential segregation of microdomains (3-5 chains) of this species within the orthorhombic phase. In contrast, the sphingosine base chains appeared to be sufficiently separated so as to inhibit interchain vibrational coupling between them. FTIR spectroscopy provides a convenient means for characterizing domain formation, chain packing, and hydration sites of these phases, which are highly ordered under physiological conditions. PMID:11018673

Chen, H; Mendelsohn, R; Rerek, M E; Moore, D J

2000-09-29

208

Study of the Crystalline Morphology Evolution of PET and PET/PC Blends by Time-resolved Synchrotron Small Angle X-ray Scattering (SAXS) and DSC  

SciTech Connect

Isothermal melt crystallization of poly(ethylene terephthalate)(PET) and PET/PC (polycarbonate) blend, with and without a transesterification catalyst, was studied by time-resolved small-angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC) in order to achieve the variation of the morphological parameters throughout the whole crystallization time. For neat PET, the catalyst promotes a decrease of the crystal lamellar thickness but for the blend no variations were observed. The effect of incorporation of catalyst in crystallization kinetics was very distinct in PET pure and the blend: in the former the catalyst leads to an increase of this kinetics while for the latter it was observed a decreasing.

Barbosa, Irineu; Larocca, Nelson M.; Hage, Elias [Dep. de Engenharia de Materiais, Universidade Federal de Sao Carlos, Sao Carlos, SP (Brazil); Plivelic, Tomas S.; Torriani, Iris L. [Laboratorio Nacional de Luz Sincrotron, Campinas, SP (Brazil); Mantovani, Gerson L. [Centro de Engenharia, Modelagem e Ciencias Sociais Aplicadas, Universidade Federal do ABC, 09090-400 Santo Andre, SP (Brazil)

2009-01-29

209

TG/DSC analysis of Fe{sub 8}(OOH){sub 16}Cl{sub 1.3} nanospindles  

SciTech Connect

The thermal analysis of Fe{sub 8}(OOH){sub 16}Cl{sub 1.3} (Akaganeite-M) nanospindles prepared by the hydrolysis of FeCl{sub 3} solutions are determined by thermogravimetric analyses and differential scanning calorimetry (TG/DSC), in conjunction with field-emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD). Different products are formed after Fe{sub 8}(OOH){sub 16}Cl{sub 1.3} nanospindles are calcined at different temperatures for 30 min in N{sub 2} atmosphere: Fe{sub 1.833}(OH){sub 0.5}O{sub 2.5} and magnetite obtained at 250 deg. C; pure magnetite (Fe{sub 3}O{sub 4}) obtained at 630 deg. C; and magnetite containing some iron nitrides (Fe{sub 2}N and Fe{sub 4}N) obtained at 800 deg. C. The calcination of Fe{sub 8}(OOH){sub 16}Cl{sub 1.3} provides a new method to prepare pure magnetite.

Hu Yinghua; Shan Yan [Key Laboratory of Nanomaterials, College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Chen Kezheng [Key Laboratory of Nanomaterials, College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China)], E-mail: kchen@qust.edu.cn

2008-10-02

210

Indirect calorimetry is a commonly used method for estimating an animal's metabolic energy expenditure based on  

E-print Network

Indirect calorimetry is a commonly used method for estimating an animal's metabolic energy. Historically, indirect calorimetry has relied largely upon measurements of oxygen consumption Determination of animal power consumption by indirect calorimetry relies upon accurate estimation of the thermal

Wolf, Blair O.

211

Photo differential scanning calorimetry, UV thermal mechanical analysis and UV dynamic  

E-print Network

Photo differential scanning calorimetry, UV thermal mechanical analysis and UV dynamic mechanical. Ultraviolet differential scanning calorimetry and ultraviolet dynamic mechanical analysis were performed curing, Curing shrinkage, Differential scanning calorimetry, Dynamic mechanical analysis, Time

North Texas, University of

212

ERROR ANALYSIS OF METHODS TO DETERMINE RESULTING CLOTHING INSULATION BY PARTITIONAL CALORIMETRY  

Microsoft Academic Search

IN'IRODUCI10N. Most thetmal models for analysis of heat balance require a value for the resultant basic insulation of the clothing ensemble. The insulation value can be determined either by using a so called thetmal manikin or by experiments on human subjects. Partitional calorimetry is a commonly used method to measure the dry heat transfer between the subject and the environmenL

Desiree Gavhed

213

Surfactant softening of plant leaf cuticle model wax--a Differential Scanning Calorimetry (DSC) and Quartz Crystal Microbalance with Dissipation (QCM-D) study.  

PubMed

The aim was to quantify the softening effect that two surfactants (C10EO7 and C8G1.6) have on a plant leaf cuticle model wax. Effects on the thermotropic phase behavior and fluidity of the wax (C22H45OH/C32H66/H2O) were determined. The model wax is crystalline at ambient conditions, yet it is clearly softened by the surfactants. Both surfactants decreased the transition temperatures in the wax and the G?/G' ratio of the wax film increased in irreversible steps following surfactant exposure. C10EO7 has a stronger fluidizing effect than C8G1.6 due to stronger interaction with the hydrophobic waxes. Intracuticular waxes (IW) comprise both crystalline and amorphous domains and it has previously been proposed that the fluidizing effects of surfactants are due to interactions with the amorphous parts. New data suggests that this may be a simplification. Surfactants may also absorb in crevices between crystalline domains. This causes an irreversible effect and a softer cuticle wax. PMID:24863760

Fagerström, Anton; Kocherbitov, Vitaly; Westbye, Peter; Bergström, Karin; Arnebrant, Thomas; Engblom, Johan

2014-07-15

214

Profiles in Leadership: Donald E. Francke, MSc, DSc (Hon)  

PubMed Central

The Director’s Forum series is designed to guide pharmacy leaders in establishing patient-centered services in hospitals and health systems. August 2013 marked the 50th anniversary of the publication of the Mirror to Hospital Pharmacy, the results of a federally funded comprehensive study of pharmacy services in the United States. The late Don E. Francke, MS, DSc, was the lead author of the Mirror and the principal investigator for the US Public Health Service grant W-45. To celebrate the anniversary of the Mirror, the Director’s Forum is profiling the leadership styles of Drs. Latiolais and Francke. September’s article highlighted Dr. Clifton J. Latiolais; this month’s Director’s Forum reviews Dr. Francke’s biography and key career accomplishments, describes his leadership philosophy, and translates that philosophy to today’s health care challenges. Don’s influence on health system pharmacy serves as an example of effective leadership. This historical perspective provides directors of pharmacy a valuable leadership view as they develop strategies to enhance patient-centered pharmacy services. PMID:24421553

Stevenson, James G.; Beham, Rachel E.; Weber, Robert J.

2013-01-01

215

Cluster calorimetry by femtosecond stimulated emission pumping: Excitation and evaporative cooling of I2  

E-print Network

Cluster calorimetry by femtosecond stimulated emission pumping: Excitation and evaporative cooling. One can then perform ``cluster calorimetry'' by monitoring the extent of CO2 evaporation as a function

Neumark, Daniel M.

216

The suitability of DSC method for damage assessment and certification of historical leathers and parchments  

Microsoft Academic Search

The DSC analysis was used for investigation of thermal behaviour in water and nitrogen, oxygen and synthetic airflow of some collagen-based materials (pure collagen, recent manufactured (new) parchments and tanned leathers, and historical (old) parchments and leathers).The shrinkage temperature values (Ts) of the investigated materials, determined by DSC analysis of the samples immersed in water, are in good agreement with

Petru Budrugeac; Lucre?ia Miu

2008-01-01

217

An Experimental Study of Transient Liquid Phase Bonding of the Ternary Ag-Au-Cu System Using Differential Scanning Calorimetry  

NASA Astrophysics Data System (ADS)

An experimental approach using differential scanning calorimetry (DSC) has been applied to quantify the solid/liquid interface kinetics during the isothermal solidification stage of transient liquid phase (TLP) bonding in an Ag-Au-Cu ternary alloy solid/liquid diffusion couple. Eutectic Ag-Au-Cu foil interlayers were coupled with pure Ag base metal to study the effects of two solutes on interface motion. Experimental effects involving baseline shift and primary solidification contribute to a systematic underestimation of the fraction of liquid remaining. A temperature program has been used to quantify and correct these effects. The experimental results show a linear relationship between the interface position and the square root of the isothermal hold time. The shifting tie line composition at the interface has been shown to affect the DSC results; however, the impact on the calculated interface kinetics has been shown to be minimal in this case. This work has increased the knowledge of isothermal solidification in ternary alloy systems and developed accurate experimental methods to characterize these processes, which is valuable for designing TLP bonding schedules.

Kuntz, M. L.; Panton, B.; Wasiur-Rahman, S.; Zhou, Y.; Corbin, S. F.

2013-08-01

218

PREFACE: XIV International Conference on Calorimetry in High Energy Physics  

NASA Astrophysics Data System (ADS)

The International Conferences on Calorimetry in High Energy Physics (also known as the Calor Conference series, started in October 1990 at Fermilab) address all aspects of calorimetric particle detection and measurement, with an emphasis on high energy physics experiments. The XIV International Conference on Calorimetry in High Energy Physics (Calor 2010) was held at the campus of the Institute of High Energy Physics, Beijing, China, from May 10-14, 2010. This conference brought together more than 110 participants from 20 countries, including senior scientists and young physicists. During the five days of the conference, 98 presentations were given in seven plenary sessions. The attendees had in-depth discussions on the latest developments and innovations in calorimetry, including the exciting new LHC results. From the presentations, 83 papers were published in this proceedings. The success of the conference was due to the participants' enthusiasm and the excellent talks given by the speakers, and to the conveners for organizing the individual sessions. We would like to thank the International Advisory Committee for giving us the opportunity to host this Conference in Beijing. Finally we would like to thank all the people involved in the organization of the Conference, who have provided valuable local support. Yifang WangChair of Local Organizing Committee International Advisory Committee M DanilovITEP Moscow M DiemozINFN Roma I A EreditatoBern F L FabbriINFN Frascati T KobayashiICEPP Tokyo M LivanPavia University & INFN P LubranoINFN Perugia S MagillANL Argonne A MaioLIPP Lisbon H OberlackMPI Munich A ParaFermilab R WigmansTTU Lubbock R YoshidaANL Argonne R ZhuCaltech Local Organizing Committee Y WangIHEP (Chair) Y GaoTshinghua University T HuIHEP (Scientific secretary) C LiUSTC W LiIHEP J LuIHEP P WangIHEP T XuIHEP L ZhouIHEP Session Conveners 1) Materials and detectors - Junguang Lu (IHEP), Francesca Nessi (CERN) 2) Algorithm and simulation - Nural Akchurin (Texas Tech University), Weidong Li (IHEP) 3) Readout techniques - Gerald Eigen (University of Bergen), Zheng Wang (IHEP) 4) Operating calorimeters and calibration - Marat Gataullin (CERN), Francesco Lanni (BNL) 5) Future calorimetry - Tohru Takeshita (Shinshu University), Lei Xia (Argonne National Laboratory) 6) Astrophysics and neutrino calorimetry - Giuliana Fiorillo (INFN), Hiro Tajima (SLAC) List of Participants AKCHURIN, NuralTexas Tech University AN, ZhenghuaIHEP AUFFRAY, EtiennetteCERN BANFI, DaniloUniversità degli Studi di Milano, INFN BASHARINA-FRESHVILLE, AnastasiaUniversity College London BEAUCHEMIN, Pierre-HuguesUniversity of Oxford BENAGLIA, Andrea DavideUniversity of Milano - Bicocca and INFN BIAN, JianminIHEP BIINO, CristinaINFN BILKI, BurakUniversity of Iowa BLAHA, JanLAPP BOUDRY, VincentLLR / CNRS-IN2P3 CAI, XiaoIHEP CAPONE, AntonioPhysics Department University "La Sapienza" and INFN CAVALLARI, FrancescaCERN and INFN Rome CECCHI, ClaudiaUniversity di Perugia e INFN CHANG, JinfanIHEP CHEN, HuchengBrookhaven National Laboratory CHILDERS, TaylorUniversität Heidelberg - Kirchhoff-Institut für Physik DAO, ValerioGeneva University - DPNC DE LA TAILLE, ChristopheIN2P3/OMEGA-LAL DIEMOZ, MarcellaINFN Roma DOTTI, AndreaCERN EIGEN, GeraldUniversity of Bergen EPIFANOV, DenisBudker Institute of Nuclear Physics FAIVRE, JulienLPSC Grenoble France FANG, JianIHEP FANG, ShuangshiIHEP FANTONI, AlessandraINFN - LNF FERRI, FedericoCEA/Saclay Irfu/SPP FERRONI, FernandoSapienza University & INFN Roma FISK, Henry EugeneFermilab GABALDON, CarolinaCERN GARUTTI, ErikaDESY GAUDIO, GabriellaIstituto Nazionale di Fisica Nucleare - Sezione di Pavia GILLBERG, DagCarleton University GIOVANNINI, PaolaMax-Planck-Institut für Physik GLAZOV, AlexanderDESY GRACHOV, OlegUniversity of Kansas HAPPACHER, FabioINFN HE, MiaoIHEP HORI, YasutoUniversity of Tokyo, CNS HU, TaoIHEP HULTH, Per-OlofStockholm University JUN, Soon YungCarnegie Mellon University JURK, StefanISEG Spezialelektronik gmbH KAVATSYUK, MyroslavKVI, University of Groningen KHRAMOV, EvgenyJoint Institute

Wang, Yifang

2011-03-01

219

Conformational study of red kidney bean (Phaseolus vulgaris L.) protein isolate (KPI) by tryptophan fluorescence and differential scanning calorimetry.  

PubMed

Fluorescence and differential scanning calorimetry (DSC) were used to study changes in the conformation of red kidney bean (Phaseolus vulgaris L.) protein isolate (KPI) under various environmental conditions. The possible relationship between fluorescence data and DSC characteristics was also discussed. Tryptophan fluorescence and fluorescence quenching analyses indicated that the tryptophan residues in KPI, exhibiting multiple fluorophores with different accessibilities to acrylamide, are largely buried in the hydrophobic core of the protein matrix, with positively charged side chains close to at least some of the tryptophan residues. GdnHCl was more effective than urea and SDS in denaturing KPI. SDS and urea caused variable red shifts, 2-5 nm, in the emission ?(max), suggesting the conformational compactness of KPI. The result was further supported by DSC characteristics that a discernible endothermic peak was still detected up to 8 M urea or 30 mM SDS, also evidenced by the absence of any shift in emission maximum (?(max)) at different pH conditions. Marked decreases in T(d) and enthalpy (?H) were observed at extreme alkaline and/or acidic pH, whereas the presence of NaCl resulted in higher T(d) and ?H, along with greater cooperativity of the transition. Decreases in T(d) and ?H were observed in the presence of protein perturbants, for example, SDS and urea, indicating partial denaturation and decrease in thermal stability. Dithiothreitol and N-ethylmaleimide have a slight effect on the thermal properties of KPI. Interestingly, a close linear relationship between the T(d) (or ?H) and the ?(max) was observed for KPI in the presence of 0-6 M urea. PMID:21126074

Yin, Shou-Wei; Tang, Chuan-He; Yang, Xiao-Quan; Wen, Qi-Biao

2011-01-12

220

Structure of water in mesoporous organosilica by calorimetry and inelastic neutron scattering  

SciTech Connect

In this paper, we describe the preparation of mesoporous organosilica samples with hydrophilic or hydrophobic organic functionality inside the silica channel. We synthesized mesoporous organosilica of identical pore sizes based on two different organic surface functionality namely hydrophobic (based on octyltriethoxysilane OTES) and hydrophilic (3-aminopropyltriethoxysilane ATES) and MCM-41 was used as a reference system. The structure of water/ice in those porous silica samples have been investigated over a range temperatures by differential scanning calorimetry (DSC) and inelastic neutron scattering (INS). INS study revealed that water confined in hydrophobic mesoporous organosilica shows vibrational behavior strongly different than bulk water. It consists of two states: water with strong and weak hydrogen bonds (with ratio 1:2.65, respectively), compared to ice-Ih. The corresponding O-O distances in these water states are 2.67 and 2.87 ?, which strongly differ compared to ice-Ih (2.76 ?). INS spectra for water in hydrophilic mesoporous organosilica ATES show behavior similar to bulk water, but with greater degree of disorder.

Levy, Esthy [Institute of Nanotechnology Bar-Ilan University, Ramat-Gan, Israel; Kolesnikov, Alexander I [ORNL; Li, Jichen [University of Manchester, UK; Mastai, Yitzhak [Institute of Nanotechnology Bar-Ilan University, Ramat-Gan, Israel

2009-01-01

221

The oxidation of aluminum at high temperature studied by Thermogravimetric Analysis and Differential Scanning Calorimetry.  

SciTech Connect

The oxidation in air of high-purity Al foil was studied as a function of temperature using Thermogravimetric Analysis with Differential Scanning Calorimetry (TGA/DSC). The rate and/or extent of oxidation was found to be a non-linear function of the temperature. Between 650 and 750 %C2%B0C very little oxidation took place; at 850 %C2%B0C oxidation occurred after an induction period, while at 950 %C2%B0C oxidation occurred without an induction period. At oxidation temperatures between 1050 and 1150 %C2%B0C rapid passivation of the surface of the aluminum foil occurred, while at 1250 %C2%B0C and above, an initial rapid mass increase was observed, followed by a more gradual increase in mass. The initial rapid increase was accompanied by a significant exotherm. Cross-sections of oxidized specimens were characterized by scanning electron microscopy (SEM); the observed alumina skin thicknesses correlated qualitatively with the observed mass increases.

Coker, Eric Nicholas

2013-10-01

222

Investigation of phase transformations in ductile cast iron of differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

The effect of heating rate on phase transformations to austenite range in ductile cast iron of the EN-GJS-450-10 grade was investigated. For studies of phase transformations, the technique of differential scanning calorimetry (DSC) was used. Micro structure was examined by optical microscopy. The calorimetric examinations have proved that on heating three transformations occur in this grade of ductile iron, viz. magnetic transformation at the Curie temperature, pearlite?austenite transformation and ferrite?austenite transformation. An increase in the heating rate shifts the pearlite?austenite and ferrite?austenite transformations to higher temperature range. At the heating rate of 5 and 15 °C min-1, local extrema have been observed to occur: for pearlite?austenite transformation at 784 °C and 795 °C, respectively, and for ferrite+ graphite ?austenite transformation at 805 °C and 821 °C, respectively. The Curie temperature of magnetic transformation was extrapolated to a value of 740 °C. Each transformation is related with a specific thermal effect. The highest value of enthalpy is accompanying the ferrite?austenite transformation, the lowest occurs in the case of pearlite?austenite transformation.

Przeliorz, R.; Pi?tkowski, J.

2011-05-01

223

Macroscopic non-equilibrium thermodynamics in dynamic calorimetry J.-L. Garden*  

E-print Network

1 Macroscopic non-equilibrium thermodynamics in dynamic calorimetry J.-L. Garden* Centre de in the literature of calorimetry, could open significant perspectives on the study of macro-systems undergoing physico-chemical transformations probed by dynamic calorimetry. Keywords: ac-calorimetry; Non

Paris-Sud XI, Université de

224

PoS(EPS-HEP2009)153 Electromagnetic Calorimetry for the ILC  

E-print Network

PoS(EPS-HEP2009)153 Electromagnetic Calorimetry for the ILC Cristina CÃ?RLOGANU Laboratoire de)153 Electromagnetic Calorimetry for the ILC Cristina CÃ?RLOGANU 1. Highly Granular Calorimeters for the International for electromagnetic calorimetry will be presented here, since the develop- ments for hadronic calorimetry were

Paris-Sud XI, Université de

225

A detailed thermal study of a Li[Ni0.33Co0.33Mn0.33]O2/LiMn2O4-based lithium ion cell by accelerating rate and differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

Accelerating rate calorimetry (ARC) and differential scanning calorimetry (DSC) were used to study the thermal behaviour of a commercially available lithium-ion cell. Both the complete cell (pouch type, 2 Ah) and its electrode materials, respectively, were investigated. As positive electrode material a blend system consisting of NCM (=Li[Ni0.33Co0.33Mn0.33]O2) and LMO (=LiMn2O4) with a weight ratio of 4:1 was identified. The main exothermic behaviour is dominated by the positive electrode-electrolyte reaction. ARC studies on the positive electrode material in presence of our reference electrolyte show an inhibiting effect of the conducting salt LiPF6 towards the oxidation of the organic based electrolyte by released oxygen. X-ray diffraction measurements were performed to study the thermal decomposition behaviour of the positive active material. Both the blend system and the single components, NCM and LMO, were investigated at different temperatures. A significant phase transformation from the hexagonal layered to a cubic structure as well as various reduction products could be identified. Finally, the thermal behaviour of the NCM/LMO-blend and its single phases, NCM and LMO, at different states of charge (SOC) was investigated. Therefore, detailed investigations based on differential scanning calorimetry (DSC) and cyclic voltammetry (CV) were performed.

Röder, P.; Baba, N.; Wiemhöfer, H.-D.

2014-02-01

226

Hydration and Lyotropic Melting of Amphiphilic Molecules: A Thermodynamic Study Using Humidity Titration Calorimetry.  

PubMed

The hydration of the lipid 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) and of the cationic detergent dodecyltrimethylammonium bromide (DTAB) has been studied by means of isothermal titration calorimetry (ITC), gravimetry, and infrared (IR) spectroscopy. During the experiments films of the amphiphiles are perfused by an inert gas of variable relative humidity. The measurement of adsorption heats using ITC represents a new adaptation of adsorption calorimetry which has been called the humidity titration technique. This method yields the partial molar enthalpy of water upon adsorption. It is found to be endothermic with respect to the molar enthalpy of water on condensation for the water molecules which interact directly with the headgroups of POPC and DTAB. Consequently, the spontaneous hydration of the amphiphiles is entropy driven in an aqueous environment. IR spectroscopy shows that hydration is accompanied by the increase in the conformational and/or motional freedom of the amphiphilic molecules upon water binding. In particular, a lyotropic chain melting transition is induced at a certain characteristic relative humidity. This event is paralleled by the adsorption of water. The corresponding exothermic adsorption heat is consumed completely (POPC) or partially (DTAB) by the hydrocarbon chains upon melting. Differential scanning calorimetry was used as an independent method to determine transition enthalpies of the amphiphiles at a definite hydration degree. Water binding onto the headgroups is discussed in terms of hydrogen bonding and polar interactions. The adsorption isotherms yield a number of approximately 2.6 tightly bound water molecules per POPC and DTAB molecule. Copyright 1999 Academic Press. PMID:10607439

Binder; Kohlstrunk; Heerklotz

1999-12-15

227

Thermal Degradation of ligno-cellulosic fuels: DSC and TGA studies V. Leroy, D. Cancellieri and E. Leoni*  

E-print Network

Thermal Degradation of ligno-cellulosic fuels: DSC and TGA studies V. Leroy, D. Cancellieri and E oxidative degradation of Mediterranean scrubs. We investigated the thermal degradation of four species; DSC were recorded in DSC and individualized using a experimental and numerical separation. This stage

Paris-Sud XI, Université de

228

Proc. DISCO '93, Springer Lect. Notes Comput. Sci., vol. 722, pp. 6680 (1993). Process Scheduling in DSC and the Large  

E-print Network

in DSC and the Large Sparse Linear Systems Challenge* A. Diaz, M. Hitz, E. Kaltofen, A. Lobo and T Internet: diaza, hitzm, kaltofen, loboa@cs.rpi.edu; t_valent@colby.edu Abstract. New features of our DSC) we introduced our DSC system for distributing large scale symbolic computations over a network

Kaltofen, Erich

229

To appear in IEEE Trans. on Parallel and Distributed Systems DSC: Scheduling Parallel Tasks on an Unbounded Number of  

E-print Network

To appear in IEEE Trans. on Parallel and Distributed Systems DSC: Scheduling Parallel Tasks the Dominant Sequence Clustering algorithm (DSC) for scheduling parallel tasks on an unbounded number of completely connected processors. The performance of DSC is comparable or even better on average than other

Yang, Tao

230

Estimation of the breathing energy of flexible MOFs by combining TGA and DSC techniques.  

PubMed

The energetics of the breathing phenomenon of MIL-53(Cr) have been estimated through a combined TGA and DSC water desorption analysis of the rigid MIL-47(V) and flexible MIL-53(Cr) and MIL-53(Fe) systems. PMID:19532937

Devautour-Vinot, Sabine; Maurin, Guillaume; Henn, François; Serre, Christian; Devic, Thomas; Férey, Gérard

2009-05-21

231

DSC Evidence for Microstructure and Phase Transitions in Polyethylene Melts at High Temperatures  

E-print Network

reported previously at temperatures significantly above the melting range. For example, NMR measurements5 5-10 mg) were compressed into aluminum sample pans for testing in a TA Instruments DSC 2910 equipped

Hussein, Ibnelwaleed A.

232

The effect of sample preparation on the DSC analysis of 6061 alloy  

Microsoft Academic Search

Deformation introduced by punching had a big impact on the response of the 6061 alloy to DSC heating. Clustering at low temperatures\\u000a was suppressed while the precipitation of the metastable precursors of the equilibrium ?-Mg2Si phase were accelerated. The ?? peak in the DSC curve has transformed into a doublet when the samples were punched after\\u000a the solution treatment. This

Yucel Birol

2005-01-01

233

Direct self-control (DSC) of inverter-fed induction machine  

Microsoft Academic Search

The new direct self-control (DSC) is a simple method of signal processing that gives converter-fed three-phase machines an excellent dynamic performance. To control the torque of, say, an induction motor, it is sufficient to process the measured signals of the stator currents and the total flux linkages only. In the basic version of DSC, the power semiconductors of a three-phase

M. Depenbrock

1988-01-01

234

Interlayer Thermal Conductivity of Rubrene Measured by ac-Calorimetry  

E-print Network

We have measured the interlayer thermal conductivity of crystals of the organic semiconductor rubrene, using ac-calorimetry. Since ac-calorimetry is most commonly used for measurements of the heat capacity, we include a discussion of its extension for measurements of the transverse thermal conductivity of thin crystals of poor thermal conductors, including the limitations of the technique. For rubrene, we find that the interlayer thermal conductivity, 0.7 mW/cm K, is several times smaller than the (previously measured) in-layer value, but its temperature dependence indicates that the interlayer mean free path is at least a few layers.

H. Zhang; J. W. Brill

2013-04-26

235

Liquid scintillator calorimetry for the LHC  

NASA Astrophysics Data System (ADS)

We report on the beam tests of full scale liquid scintillator modules designed for a very forward calorimeter for an experiment at the CERN Large Hadron Collider (LHC). Tests were performed in the electron beams of the SPS at CERN within the 20 and 150 GeV energy range. The response as a function of the beam impact point and incidence angle was measured.

Artamonov, A.; Buontempo, S.; Epstein, V.; Ereditato, A.; Fiorillo, G.; Garufi, F.; Golovkin, S.; Gorbunov, P.; Jemanov, V.; Khovansky, V.; Kruchinin, S.; Maslennikov, A.; Medvedkov, A.; Vasilchenko, V.; Zaitsev, V.; Zuckerman, I.

1995-02-01

236

Neutrino tracking calorimetry with plastic scintillator bars  

NASA Astrophysics Data System (ADS)

The technique of plastic scintillator bars coupled to wavelength shifting fibers is proposed for neutrino tracking calorimeters, in the context of very large, massive detectors for experiments on the neutrino factory beam. A prototype has been built with 180 scintillator bars interleaved with an equal number of iron bars. The light from the fibers is collected by multi-anode PMTs and converted with Amplitude-Time-Pattern self-triggering digitizing electronics. The prototype has been tested with electron and pion beams at CERN.

Giannini, Gianrossano; Santin, Giovanni; Spinetti, Mario; Votano, Lucia; Hoepfner, Kerstin

2001-10-01

237

Characterisation of an exothermic reaction using adiabatic and isothermal calorimetry  

Microsoft Academic Search

A simple esterification reaction is used to demonstrate standard procedures for determining the thermokinetic parameters of an exothermic reaction from adiabatic calorimetric data. The influence of variations in the heat capacity of the sample due to changes in temperature and concentration is explored. Shortcomings in the simple interpretation of adiabatic data are identified and isothermal heatflow calorimetry is used to

T. J. Snee; C. Barcons; H. Hernández; J. M. Zaldívar

1992-01-01

238

Preparation of Solid Derivatives by Differential Scanning Calorimetry.  

ERIC Educational Resources Information Center

Describes the preparation of selected aldehydes and ketones, alcohols, amines, phenols, haloalkanes, and tertiaryamines by differential scanning calorimetry. Technique is advantageous because formation of the reaction product occurs and the melting point of the product is obtained on the same sample in a short time with no additional purification…

Crandall, E. W.; Pennington, Maxine

1980-01-01

239

Present state and trends in the development of combustion calorimetry  

Microsoft Academic Search

Modern bomb and gas calorimeters produced in Russia and abroad are reviewed. The main trends and ways of improving bomb calorimeters\\u000a are described in retrospective form. Problems and aims in the area of gas calorimetry are considered.

E. N. Korchagina

1998-01-01

240

Calorimetry 101 for Cold Fusion; Methods, Problems and Errors  

Microsoft Academic Search

Application of calorimetry to cold fusion or LENR presents unique problems that have not been previously summarized. This paper discusses various calorimetric methods that have been applied to the subject and evaluates each in light of what has been discovered about their limitations and errors based on experimental studies. Such information is essential to a study of the effect and

Edmund Storms

241

Relaxation calorimetry technique for measuring low temperature specific heat  

E-print Network

Relaxation calorimetry technique for measuring low temperature specific heat R. W. Newsome, Jr cost measurement of the temperature dependence of the spe- cific heat of a 10 thick copolymer film Received 6 June 2003; accepted 15 October 2003 A rudimentary calorimeter was constructed to measure

Andrei, Eva Y.

242

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

243

Test in a beam of large-area Micromegas chambers for sampling calorimetry  

E-print Network

Application of Micromegas for sampling calorimetry puts specific constraints on the design and performance of this gaseous detector. In particular, uniform and linear response, low noise and stability against high ionisation density deposits are prerequisites to achieving good energy resolution. A Micromegas-based hadronic calorimeter was proposed for an application at a future linear collider experiment and three technologically advanced prototypes of 1$\\times$1 m$^{2}$ were constructed. Their merits relative to the above-mentioned criteria are discussed on the basis of measurements performed at the CERN SPS test-beam facility.

Adloff, C; Dalmaz, A; Drancourt, C; Gaglione, R; Geffroy, N; Jacquemier, J; Karyotakis, Y; Koletsou, I; Peltier, F; Samarati, J; Vouters, G

2014-01-01

244

Test in a beam of large-area Micromegas chambers for sampling calorimetry  

E-print Network

Application of Micromegas for sampling calorimetry puts specific constraints on the design and performance of this gaseous detector. In particular, uniform and linear response, low noise and stability against high ionisation density deposits are prerequisites to achieving good energy resolution. A Micromegas-based hadronic calorimeter was proposed for an application at a future linear collider experiment and three technologically advanced prototypes of 1$\\times$1 m$^{2}$ were constructed. Their merits relative to the above-mentioned criteria are discussed on the basis of measurements performed at the CERN SPS test-beam facility.

C. Adloff; M. Chefdeville; A. Dalmaz; C. Drancourt; R. Gaglione; N. Geffroy; J. Jacquemier; Y. Karyotakis; I. Koletsou; F. Peltier; J. Samarati; G. Vouters

2014-05-03

245

Test in a beam of large-area Micromegas chambers for sampling calorimetry  

NASA Astrophysics Data System (ADS)

The application of Micromegas for sampling calorimetry puts specific constraints on the design and performance of this gaseous detector. In particular, uniform and linear response, low noise and stability against high ionisation density deposits are prerequisites for achieving good energy resolution. A Micromegas-based hadronic calorimeter was proposed for an application at a future linear collider experiment and three technologically advanced prototypes of 1×1 m2 were constructed. Their merits relative to the above-mentioned criteria are discussed on the basis of measurements performed at the CERN SPS test-beam facility.

Adloff, C.; Chefdeville, M.; Dalmaz, A.; Drancourt, C.; Gaglione, R.; Geffroy, N.; Jacquemier, J.; Karyotakis, Y.; Koletsou, I.; Peltier, F.; Samarati, J.; Vouters, G.

2014-11-01

246

The retrogradation properties of glutinous rice and buckwheat starches as observed with FT-IR, 13C NMR and DSC.  

PubMed

The experiment was conducted to study the retrogradation properties of glutinous rice and buckwheat starch with wavelengths of maximum absorbance, FT-IR, (13)C NMR, and DSC. The results show that the starches in retrograded glutinous rice starch and glutinous rice amylopectin could not form double helix. The IR results show that protein inhabits in glutinous rice and maize starches in a different way and appearance of C-H symmetric stretching vibration at 2852 cm(-1) in starch might be appearance of protein. Retrogradation untied the protein in glutinous amylopectin. Enthalpies of sweet potato and maize granules are higher than those of their retrograded starches. The (13)C NMR results show that retrogradation of those two starches leads to presence of ?-anomers and retrogradation might decompose lipids in glutinous rice amylopectin into small molecules. Glutinous rice starch was more inclined to retrogradation than buckwheat starch. The DSC results show that the second peak temperatures for retrograded glutinous rice and buckwheat starches should be assigned to protein. The SEM results show that an obvious layer structure exists in retrograded glutinous rice amylopectin. PMID:24360894

Lian, Xijun; Wang, Changjun; Zhang, Kunsheng; Li, Lin

2014-03-01

247

Monolithic circuits for lead-glass calorimetry  

SciTech Connect

Electronics developed for signal processing, digitization, and readout of a 10,000-element lead-glass electromagnetic calorimeter for CERN experiment WA98 are described. Chief among the components developed are two CMOS monolithic circuits. One, known as the ``Preamp`` chip, includes eight channels each of integrator, dual gain amplifier, fast shaping amplifier, constant fraction discriminator, and also two 2 {times} 2 current sums for trigger purposes, and maskable calibration pulsers for the time and energy channels. It also includes three 6-bit DACs for setting thresholds and calibration values. The other chip, known as the ``ATA`` (AMU/TAC/ADC) chip, includes 16 channels of AMU (analog memory unit), 8 channels of TAC, and 24 channels of Wilkinson-type ADC. A description of these chips` design and performance is given, together with a short description of supporting circuitry and of initial system performance as measured with 2- to 20-GeV electrons.

Wintenberg, A.L.; Awes, T.C.; Britton, C.L. Jr. [and others

1994-09-01

248

Thermochimica Acta 447 (2006) 5256 Metabolic heat and CO2 evolution rates measured by calorimetry during  

E-print Network

Thermochimica Acta 447 (2006) 52­56 Metabolic heat and CO2 evolution rates measured by calorimetry theoretical understanding of the process is still necessary. The use of calorimetry may provide a method

Lieth, J. Heinrich

249

Nanoscale, Phonon-Coupled Calorimetry with Sub-Attojoule/Kelvin Resolution  

E-print Network

Nanoscale, Phonon-Coupled Calorimetry with Sub-Attojoule/Kelvin Resolution W. Chung Fon, Keith. C upon an active surface area of only 1.2 Ã? 10-9 m2. Calorimetry is a powerful technique that is widely

250

REVIEW OF SCIENTIFIC INSTRUMENTS 82, 023908 (2011) Calorimetry of epitaxial thin films  

E-print Network

REVIEW OF SCIENTIFIC INSTRUMENTS 82, 023908 (2011) Calorimetry of epitaxial thin films David W.1063/1.3554440] I. INTRODUCTION Calorimetry is a useful technique for observing a host of physical phenomena from

Hellman, Frances

251

Differential Scanning Calorimetry and Evolved Gas Analysis of Hydromagnesite  

NASA Technical Reports Server (NTRS)

Volatile-bearing minerals (e.g., Fe-oxyhydroxides, phyllosilicates, carbonates and sulfates) may be important phases on the surface of Mars. In order to characterize these phases the Thermal and Evolved Gas Analyzer (TEGA) flying on the Mars'98 lander will perform analyses on surface samples from Mars. Hydromagnesite [Mg5(CO3)4(OH)2.4H2O] is considered a good standard mineral to examine as a Mars soil analog component because it evolves both H2O and CO2 at temperatures between 0 and 600 C. Our aim here is to interpret the DSC signature of hydromagnesite under ambient pressure and 20 sccm N2 flow in the range 25 to 600 C. The DSC curve for hydromagnesite under the above conditions consists of three endothermic peaks at temperatures 296, 426, and 548 and one sharp exotherm at 511 C. X-ray analysis of the sample at different stop temperatures suggested that the exotherm corresponded with the formation of crystalline magnesite. The first endotherm was due to dehydration of hydromagnesite, and then the second one was due to the decomposition of carbonate, immediately followed by the formation of magnesite (exotherm) and its decomposition to periclase (last endotherm). Evolution of water and CO2 were consistent with the observed enthalpy changes. A library of such DSC-evolved gas curves for putative Martian minerals are currently being acquired in order to facilitate the interpretation of results obtained by a robotic lander.

Lauer, H. V., Jr.; Golden, D. C.; Ming, Douglas W.; Boynton, W. V.

1999-01-01

252

Differential scanning calorimetry and electron diffraction investigation on low-temperature aging in Al-Zn-Mg alloys  

SciTech Connect

Differential scanning calorimetry (DSC) has been combined with transmission electron microscopy (TEM) to investigate the low-temperature decomposition processes taking place in an Al-5 wt pct Zn-1 wt pct Mg alloy. It was confirmed that two types of GP zones, i.e., GP(I) (solute-rich clusters) and GP(II) (vacancy-rich clusters), formed independently during decomposition of the supersaturated solid solution. The GP(I) zones form at a relatively low aging temperature and dissolve when the aging temperature is increased. The GP(II) zones are stable over a wider range of temperatures. To investigate the nature of the zones in the Al-Zn-Mg alloy, differential scanning calorimetry and transmission electron microscopy have also been carried out on binary Al-Zn alloys containing 5 wt pct and 10 wt pct Zn. In these Al-Zn alloys, GP zones formed rapidly during quenching, and they gave rise to characteristic electron diffraction patterns identical to those from GP(II) in the Al-Zn-Mg alloy system, implying that GP(II) zones in Al-Zn-Mg alloys are very similar to the zones formed in binary Al-Zn alloys. Thus, it is likely that GP(II) zones in Al-Zn-Mg alloys are zinc-rich clusters. In the Al-5 wt pct Zn-1 wt pct Mg alloy, both GP(I) and GP(II) were found to transform to {eta}{prime} and/or {eta} particles during heating in the differential scanning calorimeter. The {eta}{prime} was also observed to form after prolonged isothermal aging of the Al-Zn-Mg alloy at 75 C or after short aging times at 125 C.

Jiang, X.J.; Noble, B.; Holme, B.; Waterloo, G.; Tafto, J.

2000-02-01

253

Comparative kinetic analysis on thermal degradation of some cephalosporins using TG and DSC data  

PubMed Central

Background The thermal decomposition of cephalexine, cefadroxil and cefoperazone under non-isothermal conditions using the TG, respectively DSC methods, was studied. In case of TG, a hyphenated technique, including EGA, was used. Results The kinetic analysis was performed using the TG and DSC data in air for the first step of cephalosporin’s decomposition at four heating rates. The both TG and DSC data were processed according to an appropriate strategy to the following kinetic methods: Kissinger-Akahira-Sunose, Friedman, and NPK, in order to obtain realistic kinetic parameters, even if the decomposition process is a complex one. The EGA data offer some valuable indications about a possible decomposition mechanism. The obtained data indicate a rather good agreement between the activation energy’s values obtained by different methods, whereas the EGA data and the chemical structures give a possible explanation of the observed differences on the thermal stability. A complete kinetic analysis needs a data processing strategy using two or more methods, but the kinetic methods must also be applied to the different types of experimental data (TG and DSC). Conclusion The simultaneous use of DSC and TG data for the kinetic analysis coupled with evolved gas analysis (EGA) provided us a more complete picture of the degradation of the three cephalosporins. It was possible to estimate kinetic parameters by using three different kinetic methods and this allowed us to compare the Ea values obtained from different experimental data, TG and DSC. The thermodegradation being a complex process, the both differential and integral methods based on the single step hypothesis are inadequate for obtaining believable kinetic parameters. Only the modified NPK method allowed an objective separation of the temperature, respective conversion influence on the reaction rate and in the same time to ascertain the existence of two simultaneous steps. PMID:23594763

2013-01-01

254

19BLPCn278october-december 2010 Quasi-adiabatic calorimetry  

E-print Network

19BLPC·n°278·october-december 2010 Quasi-adiabatic calorimetry forconcretes:Influentialfactors AbstrAct Quasi-adiabatic calorimetry performed on concrete specimens (known under the French acronym QAB, the thermomechanical behavior of structures. The present article offers a description of the calorimetry equipment

Boyer, Edmond

255

Monitoring of an RNA Multistep Folding Pathway by Isothermal Titration Calorimetry  

E-print Network

Monitoring of an RNA Multistep Folding Pathway by Isothermal Titration Calorimetry Ce�dric Reymond Sherbrooke, Sherbrooke, Que�bec, Canada ABSTRACT Isothermal titration calorimetry was used to monitor calorimetry appears to be a method of choice for the elucidation of an RNA's folding pathway. INTRODUCTION

Perreault, Jean-Pierre

256

Construction and test of a 1x1 m2 Micromegas chamber for sampling hadron calorimetry  

E-print Network

Construction and test of a 1x1 m2 Micromegas chamber for sampling hadron calorimetry at future are reported. Keywords: Large area Micromegas, Micro Pattern Gaseous Detectors, Digital hadron calorimetry, Future linear colliders 1. Introduction1 1.1. Particle Flow calorimetry2 The detailed study

Paris-Sud XI, Université de

257

Online Electron/Jet Neural High-level Trigger Over Independent Calorimetry Information  

E-print Network

Online Electron/Jet Neural High-level Trigger Over Independent Calorimetry Information Rodrigo/jet discriminator that uses the highly segmented calorimetry information. In this work, we address the electron/jet sepa- ration using information provided by the calorimetry system of ATLAS. Calorimeters play a major

Anjos, André

258

The energy density of jellyfish: Estimates from bomb-calorimetry and proximate-composition  

E-print Network

The energy density of jellyfish: Estimates from bomb-calorimetry and proximate-composition Thomas K scyphozoan jellyfish (Cyanea capillata, Rhizostoma octopus and Chrysaora hysoscella). First, bomb-calorimetry). These proximate data were subsequently converted to energy densities. The two techniques (bomb- calorimetry

Hays, Graeme

259

John Marshall Particle Flow Calorimetry 1 J.S. Marshall, M.A. Thomson  

E-print Network

John Marshall Particle Flow Calorimetry 1 J.S. Marshall, M.A. Thomson University of Cambridge #12;John Marshall Particle Flow Calorimetry 2 Overview 1. e+e- Physics and LC Jet Energy Requirements 2. Particle Flow Calorimetry 3. Pandora Particle Flow Reconstruction Algorithms 4. Particle Flow Performance

Glasgow, University of

260

Thermochimica Acta 331 (1999) 93204 Reference materials for calorimetry and differential thermal analysis  

E-print Network

Thermochimica Acta 331 (1999) 93­204 Reference materials for calorimetry and differential thermal with reference materials (in abbre- viated form: RM) for calorimetry and differential ther- mal analysis]. Calorimetry and differential thermal analysis are ap- plicable to a wide range of scientific and technological

Chickos, James S.

261

Study of crystallization of Y-based metallic glasses by differential scanning calorimetry and neutron diffraction  

E-print Network

1541 Study of crystallization of Y-based metallic glasses by differential scanning calorimetry investigated by differential scanning calorimetry and neutron diffraction. The crystallization occurs in two calorimetry [1-6]. In the kinetic approach of crystal- lization, Buschow [1, 2] has shown that the crystalli

Paris-Sud XI, Université de

262

A scanning AC calorimetry technique for the analysis of nano-scale quantities of materials  

E-print Network

A scanning AC calorimetry technique for the analysis of nano-scale quantities of materials Kechao OF SCIENTIFIC INSTRUMENTS 83, 114901 (2012) A scanning AC calorimetry technique for the analysis of nano 2012) We present a scanning AC nanocalorimetry method that enables calorimetry measurements at heating

263

Use of infrared thermographic calorimetry to determine energy expenditure in preterm infants 1-3  

Microsoft Academic Search

Background: Measurement of infant energy expenditure in the clinical setting is difficult and is rarely done. Both indirect and direct calorimetry require long measurement periods and fre- quent calibration. Objective: The objective of this study was to validate in infants a newly developed method of determining energy expenditure, infrared thermographic calorimetry (ITC), against an established method, respiratory indirect calorimetry (IC).

Alexandra K Adams; Ralph A Nelson; Edward F Bell; Cesar A Egoavil

264

2H-solid state NMR and DSC study of isobutyric acid in mesoporous silica materials.  

PubMed

Solid state deuterium NMR has been used to study the molecular motion of d(6)-isobutyric acid (d(6)-iBA) in the pure (unconfined) state and confined in the cylindrical pores of two periodic mesoporous silica materials (MCM-41, pore size 3.3 nm and SBA-15, pore size 8 nm), and in a controlled pore glass (CPG-10-75, pore size ca. 10 nm). The line shape analysis of the spectra at different temperatures revealed three rotational states of the iBA molecules: liquid (fast anisotropic reorientation of the molecule), solid I (rotation of the methyl group) and solid II (no rotational motion on the time scale of the experiment). Transition temperatures between these states were determined from the temperature dependence of the fraction of molecules in these states. Whereas the solid I-solid II transition temperature is not affected by confinement, a significant lowering of the liquid-solid I transition temperature in the pores relative to the bulk acid was found for the three matrix materials, exhibiting an unusual dependence on pore size and pore morphology. Complementary DSC measurements on the same systems show that the rotational melting (solid I-liquid) of d(6)-iBA in the pores occurs at a temperature 20-45 K below the thermodynamic melting point. This finding indicated that the decoupling of rotational and translational degrees of freedom in phase transitions in confined systems previously found for benzene is not restricted to molecules with non-specific interactions, but represents a more general phenomenon. PMID:17487322

Vyalikh, A; Emmler, Th; Shenderovich, I; Zeng, Y; Findenegg, G H; Buntkowsky, G

2007-06-14

265

Student understanding of calorimetry in introductory calculus-based physics  

NASA Astrophysics Data System (ADS)

We report on students' thinking regarding calorimetry concepts in an introductory calculus-based physics course. We found that despite overall good performance, only about half of the students were able to provide correct answers with satisfactory explanations. A number of persistent student difficulties were found to affect approximately 40% of the students even after instruction, including apparent confusion about the meaning of specific heat and misunderstanding of the nature of thermal energy exchange. Student response patterns varied significantly depending on the context of the question and often reasoning did not appear to be consistent among contexts, instead favoring "rule-based" reasoning. Interviews with students suggest that difficulty with algebraic manipulations is a significant contributor to incorrect responses on calorimetry questions.

Christensen, Warren M.; Meltzer, David E.; Nguyen, Ngoc-Loan

2011-11-01

266

Temperature modulated DSC studies of melting and recrystallization in polymers exhibiting multiple endotherms  

Microsoft Academic Search

Temperature-modulated DSC (TMDSC) is used to characterize melting and recrystallization in polymers exhibiting multiple melting endotherms. Poly(ethylene-2,6-naphthalenedicarboxylate)(PEN) and poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene)(PEEK) are chosen, and the data show the detailed contributions of thermal and processing histories to properties. The results are supplemented by standard DSC at different heating rates. By independent very rapid heating rate methods, the temperature at which the polymer first

B. B Sauer; W. G Kampert; E Neal Blanchard; S. A Threefoot; B. S Hsiao

2000-01-01

267

The calorimetry at the future e+ e- linear collider  

E-print Network

The physics programme for a coming electron linear collider is dominated by events with final states containing many jets. We develop in this paper the opinion that the best approach is to optimise the independent measurement of the tracks in the tracker, the photons in the electromagnetic calorimeter and the neutral hadrons in the camorimetry, together with a good lepton identification. This can be achieved with a high granularity calorimetry providing particle separation, through an efficient energy flow algorithm.

J-C. Brient; H. Videau

2002-02-01

268

Tritium inventory measurements by `in-bed` gas flowing calorimetry  

Microsoft Academic Search

In order to establish the `in-bed` tritium accounting technology for the ITER scale tritium storage system, a gas flowing calorimetry has been studied using a scaled ZrCo bed (25 g tritium capacity). The basic calorimetric characteristics, steady state temperature raise of He gas stream flowing through a secondary coil line fixed in the ZrCo tritide, was measured and correlated with

T. Hayashi; T. Suzuki; M. Yamada; K. Okuno

1996-01-01

269

Tritium accounting characteristics of `in-bed` gas flowing calorimetry  

Microsoft Academic Search

A scaled ZrCo bed (25 g tritium capacity of design) with gas flowing calorimetry system was fabricated to establish the `in-bed` tritium accounting technology to apply to the ITER tritium storage beds. The basic calorimetric characteristics, steady state temperature raise of He gas stream flowing through a secondary coil line fixed in the ZrCo tritide, was measured and correlated with

T. Hayashi; M. Yamada; T. Suzuki; Y. Matsuda; K. Okuno

1995-01-01

270

Aging of polycarbonate studied by temperature modulated differential scanning calorimetry  

Microsoft Academic Search

The enthalpy relaxation behaviour of polycarbonate has been studied by alternating differential scanning calorimetry (ADSC). Samples have been annealed at 125°C, about 20°C below their glass transition temperature, for periods up to 2000h, and then scanned in the ADSC using the modulation conditions: heating rate=1Kmin?1; temperature amplitude=1K; period=1min. The data have been analysed in terms of total, reversing and non-reversing

John M Hutchinson; Ang Boon Tong; Zhong Jiang

1999-01-01

271

The Philosophy and Feasibility of Dual Readout Calorimetry  

SciTech Connect

I will discuss the general physical ideas behind dual-readout calorimetry, their implementation in DREAM (Dual REAdout Module) with exact separation of scintillation and Cerenkov light, implementation with mixed light in DREAM fibers, anticipated implementation in PbWO4 crystals with applications to the 4th Concept detector and to CMS, use in high energy gamma-ray and cosmic ray astrophysics with Cerenkov and N2 fluorescent light, and implementation in the 4th Concept detector for muon identification.

Hauptman, John [Physics, Iowa State University, Ames IA 50011 (United States)

2006-10-27

272

Helium droplet calorimetry of strongly bound species: Carbon clusters from C2 to C12  

NASA Astrophysics Data System (ADS)

Helium droplet beam methods are a versatile technique that can be used to assemble a wide variety of atomic and molecular clusters. In recent years, methods have been developed to utilize helium droplets as nano-calorimeters to measure the binding energies of weakly bound complexes assembled within the droplet. In the current investigation we extend the helium droplet calorimetry approach to the study of a very strongly bound system: carbon clusters which are bound by several eV per atom. We utilize laser heating of bulk carbon samples to dope the helium droplets with evaporated carbon species. Depending on the laser target, the vaporization plume is found to consist primarily of C3 alone or C2 and C3. These species are sequentially captured by the droplet and assembled into larger carbon clusters in a stepwise manner. The assembled Cn clusters are detected via mass spectrometry of the doped droplets and the droplet sizes required to detect the various carbon clusters observed are used to estimate the reaction energies of the associated assembly pathways. The helium droplet data qualitatively reflect the trends in assembly energetics, but at first glance appear to yield energies that differ dramatically from theoretical values. Statistical modeling of the helium droplet calorimetry experiment reconciles the differences quantitatively. Our modeling also generates a calibration curve that relates the assembly/reaction energy and threshold mean droplet size over a range of energies from van der Waals interactions to chemical bonding, enabling helium droplet calorimetry methods to be applied quantitatively to a large number of systems.

Lewis, William K.; Harruff-Miller, Barbara A.; Leatherman, Peter; Gord, Michael A.; Bunker, Christopher E.

2014-09-01

273

Helium droplet calorimetry of strongly bound species: Carbon clusters from C2 to C12.  

PubMed

Helium droplet beam methods are a versatile technique that can be used to assemble a wide variety of atomic and molecular clusters. In recent years, methods have been developed to utilize helium droplets as nano-calorimeters to measure the binding energies of weakly bound complexes assembled within the droplet. In the current investigation we extend the helium droplet calorimetry approach to the study of a very strongly bound system: carbon clusters which are bound by several eV per atom. We utilize laser heating of bulk carbon samples to dope the helium droplets with evaporated carbon species. Depending on the laser target, the vaporization plume is found to consist primarily of C3 alone or C2 and C3. These species are sequentially captured by the droplet and assembled into larger carbon clusters in a stepwise manner. The assembled Cn clusters are detected via mass spectrometry of the doped droplets and the droplet sizes required to detect the various carbon clusters observed are used to estimate the reaction energies of the associated assembly pathways. The helium droplet data qualitatively reflect the trends in assembly energetics, but at first glance appear to yield energies that differ dramatically from theoretical values. Statistical modeling of the helium droplet calorimetry experiment reconciles the differences quantitatively. Our modeling also generates a calibration curve that relates the assembly/reaction energy and threshold mean droplet size over a range of energies from van der Waals interactions to chemical bonding, enabling helium droplet calorimetry methods to be applied quantitatively to a large number of systems. PMID:25273742

Lewis, William K; Harruff-Miller, Barbara A; Leatherman, Peter; Gord, Michael A; Bunker, Christopher E

2014-09-01

274

REDES DE COMPUTADORES UFPB / CCT / DSC / PSN, 2001 * Parte 4: Estudo de Caso -RPP/RNP * Pg. 1  

E-print Network

REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 4: Estudo de Caso - RPP/RNP * Pág. 1 3. REDES DE COMPUTADORES © UFPB / CCT / DSC / PSN, 2001 * Parte 4: Estudo de Caso - RPP/RNP * Pág. 2 ! Sua / CCT / DSC / PSN, 2001 * Parte 4: Estudo de Caso - RPP/RNP * Pág. 3 ! A partir de 1986, a INTERNET

Cirne, Walfredo

275

A Second Look at Mini-Protein Stability: Analysis of FSD-1 Using Circular Dichroism, Differential Scanning Calorimetry, and Simulations  

E-print Network

Scanning Calorimetry, and Simulations Jianwen A. Feng, * Jeff Kao, and Garland R. Marshall Center, was investigated using circular dichroism, differential scanning calorimetry, and replica-exchange molecular

Marshall, Garland R.

276

A Strategy for Improving and Integrating Biomedical Ontologies Cornelius Rosse, MD, DSc,a,b  

E-print Network

species, new anatomy terminologies were recently developed for each of these species in the NCI ThesaurusA Strategy for Improving and Integrating Biomedical Ontologies Cornelius Rosse, MD, DSc,a,b AnandD,d,e Structural Informatics Group, Departments of Biological Structurea , Medical Education and Biomedical

Washington at Seattle, University of

277

A structural study of DPP-based sensitizers for DSC applications.  

PubMed

Four D-?-A sensitizers comprising a thienyl-diketopyrrolopyrrole (ThDPP) bridge were synthesized and tested in iodide/triiodide liquid electrolyte DSC devices. The dye series was strategically designed to develop a structure-property relationship. The best performing sensitizer utilized a phenyl-based anchor and triphenylamine donor (? = 5.03%). PMID:23019568

Holcombe, Thomas W; Yum, Jun-Ho; Yoon, Junghyun; Gao, Peng; Marszalek, Magdalena; Di Censo, Davide; Rakstys, Kasparas; Nazeeruddin, Md K; Graetzel, Michael

2012-11-11

278

DSC studies of Fusarium solani pisi cutinase: consequences for stability in the presence of surfactants  

Microsoft Academic Search

The application of cutinase from Fusarium solani pisi as a fat-stain removing ingredient in laundry washing is hampered by its lack of stability in the presence of anionic surfactants. We postulate that the stability of cutinase towards anionics can be improved by mutations increasing its temperature stability. Thermal unfolding as measured with DSC, appears to be irreversible, though the thermograms

Lucia D. Creveld; Wim Meijberg; Herman J. C. Berendsen; Henri A. M. Pepermans

2001-01-01

279

Multispectral image compression based on DSC combined with CCSDS-IDC.  

PubMed

Remote sensing multispectral image compression encoder requires low complexity, high robust, and high performance because it usually works on the satellite where the resources, such as power, memory, and processing capacity, are limited. For multispectral images, the compression algorithms based on 3D transform (like 3D DWT, 3D DCT) are too complex to be implemented in space mission. In this paper, we proposed a compression algorithm based on distributed source coding (DSC) combined with image data compression (IDC) approach recommended by CCSDS for multispectral images, which has low complexity, high robust, and high performance. First, each band is sparsely represented by DWT to obtain wavelet coefficients. Then, the wavelet coefficients are encoded by bit plane encoder (BPE). Finally, the BPE is merged to the DSC strategy of Slepian-Wolf (SW) based on QC-LDPC by deep coupling way to remove the residual redundancy between the adjacent bands. A series of multispectral images is used to test our algorithm. Experimental results show that the proposed DSC combined with the CCSDS-IDC (DSC-CCSDS)-based algorithm has better compression performance than the traditional compression approaches. PMID:25110741

Li, Jin; Xing, Fei; Sun, Ting; You, Zheng

2014-01-01

280

Stress Relaxation Under Various Stress and Drainage Conditions Gilberto F. Alexandre, D.Sc.  

E-print Network

1 Stress Relaxation Under Various Stress and Drainage Conditions Gilberto F. Alexandre, D.Sc. Ian S for stress relaxation tests carried out by Garcia (1996) in the edometric apparatus in a soft organic clay by Terzaghi (1941), Taylor (1942) and others. The differential equation of the stress relaxation test, its

Paris-Sud XI, Université de

281

Coupled Analyses of Excavations in Saturated Soil Christianne de Lyra Nogueira, D.Sc.1  

E-print Network

Coupled Analyses of Excavations in Saturated Soil Christianne de Lyra Nogueira, D.Sc.1 ; Roberto presents finite-element analyses of excavations by using a coupled deformation and flow formulation. Specific numerical procedures were implemented into the finite-element codes to simulate the excavation

Zornberg, Jorge G.

282

Comparative study of specific heat capacities of some vegetable oils obtained by DSC and microwave oven  

Microsoft Academic Search

Summary TG and DSC analyses were carried out in this work to evaluate the changes in the denaturation of human hair keratin submitted to different chemical effects. Hair bleaching and chlorinating treatments caused changes in the denaturation temperatures and denaturation enthalpies of hair keratin. Bleached hair and hair kept in a chlorinated solution presented a lower denaturation enthalpy and a

J. C. O. Santos; M. G. O. Santos; J. P. Dantas; Marta M. Conceição; P. F. Athaide-Filho; A. G. Souza

2005-01-01

283

Determining the main thermodynamic parameters of caffeine melting by means of DSC  

NASA Astrophysics Data System (ADS)

The temperature and enthalpy of the melting of caffeine, which are 235.5 ± 0.1°C and 19.6 ± 0.2 kJ/mol, respectively, are determined by DSC. The melting entropy and the cryoscopic constant of caffeine are calculated.

Agafonova, E. V.; Moshchenskii, Yu. V.; Tkachenko, M. L.

2012-06-01

284

Principles for the interpretation of modulated temperature DSC measurements. Part 1. Glass transition  

Microsoft Academic Search

A new evaluation method for modulated temperature-DSC measurements based on linear response theory is presented. This yields a complex heat capacity with a real part (storage heat capacity) and an imaginary part (loss heat capacity). This approach makes irreversible (time dependent) thermal events amenable to quantitative and theoretically founded discussion.This is shown by theoretical analysis and demonstrated experimentally using the

J. E. K. Schawe

1995-01-01

285

States of water in different hydrophilic polymers — DSC and FTIR studies  

Microsoft Academic Search

The structure of water molecules sorbed in different hydrophilic polymers was studied by DSC and FTIR. The obtained data shows that, first, the sorbed water molecules are directly bound to the hydrophilic site to form non-freezable water. Then, beyond a certain water content threshold, the sorbed water molecules become freezable, but with a melting point lower than 0°C, due to

Z. H Ping; Q. T Nguyen; S. M Chen; J. Q Zhou; Y. D Ding

2001-01-01

286

Determination of reaction kinetic parameters from variable temperature DSC or DTA  

Microsoft Academic Search

An equation is derived for evaluating the kinetic parameters of a transformation from variable temperature DSC or DTA, taking account of the variation in the reaction rate constant with time and temperature. Kinetic parameters for the crystallization of a ZrF4-BaF2-LaF3 glass are calculated using this equation.

N. P. Bansal; R. H. Doremus

1984-01-01

287

DSC studies on bovine serum albumin denaturation Effects of ionic strength and SDS concentration  

Microsoft Academic Search

This work analyzed the thermal denaturation process of defatted bovine serum albumin (BSA). DSC measurements were performed on changing the pH, the ionic strength and the sodium dodecyl sulfate (SDS) concentration. These data have been compared with those previously obtained by us and other authors. The purpose of these measurements was to study the correlation between the three-dimensional organization of

Concetta Giancola; Cira De Sena; Dimitrios Fessas; Giuseppe Graziano; Guido Barone

1997-01-01

288

Preformulation Studies of Zidovudine Derivatives: Acid Dissociation Constants, Differential Scanning Calorimetry, Thermogravimetry, X-Ray Powder Diffractometry and Aqueous Stability Studies  

PubMed Central

As part as of the preformulation studies of new 5?-OH derivatives of zidovudine, compounds 2–6, their acid dissociation constants, Differential Scanning Calorimetry (DSC) and Thermogravimetry (TG) curves, X-Ray Powder diffractograms and aqueous stability are reported. A sensitive technique such as differential scanning potentiometry was used to determine the pKa constants of the above mentioned compounds. In addition, pKa values were calculated from theoretical methods, and no significant differences with those of experimental ones were observed. X-Ray Powder Diffractometry data demonstrated that compounds 2–4 were crystalline while 5 and 6 were amorphous. DSC analysis indicated that all of them presented an exothermic decomposition peak above 150 °C which is accompanied by a weight loss in the respective TG curves. The stability of these compounds in aqueous medium at different pH values was investigated, using a validated High Performance Liquid Chromatography (HPLC) method, which demonstrated to be rapid, selective, sensitive, accurate and stability-indicating. Good recovery, linearity and precision were also achieved. For all compounds the aqueous hydrolysis followed a pseudo-first-order kinetics, depending on pH and the union existing between AZT and the associate moiety. The hydrolysis was catalyzed by hydroxide ion in the 7.4–13.2 pH range, while all compounds exhibited pH-independent stability from acidic to neutral media (pHs 1.0–7.4). PMID:21886898

Raviolo, Monica A.; Brinon, Margarita C.

2011-01-01

289

Direct measurement of grain boundary enthalpy of cubic yttria-stabilized zirconia by differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

A straight-forward set of experiments using differential scanning calorimetry was used to obtain the average grain boundary enthalpy at high temperatures for 10 mol. % yttria-stabilized zirconia (10YSZ) by exploiting the heat of grain growth on nanograined dense samples consolidated by spark plasma sintering. The heat of grain growth was measured and correlated with the quantified microstructure evolution during the process. The average grain boundary enthalpy of 10YSZ was found to be 1.00 ± 0.29 J m-2 for the temperature range 900-1300 °C. Comparing this result with room temperature data in the literature, small temperature dependence of the grain boundary enthalpy could be found outside the experimental uncertainties in both experiments.

Quach, Dat V.; Castro, Ricardo H. R.

2012-10-01

290

Estimation of the nucleation rate by differential scanning calorimetry  

NASA Technical Reports Server (NTRS)

A realistic computer model is presented for calculating the time-dependent volume fraction transformed during the devitrification of glasses, assuming the classical theory of nucleation and continuous growth. Time- and cluster-dependent nucleation rates are calculated by modeling directly the evolving cluster distribution. Statistical overlap in the volume fraction transformed is taken into account using the standard Johnson-Mehl-Avrami formalism. Devitrification behavior under isothermal and nonisothermal conditions is described. The model is used to demonstrate that the recent suggestion by Ray and Day (1990) that nonisothermal DSC studies can be used to determine the temperature for the peak nucleation rate, is qualitatively correct for lithium disilicate, the glass investigated.

Kelton, Kenneth F.

1992-01-01

291

Kinetics of enzymatic high-solid hydrolysis of lignocellulosic biomass studied by calorimetry.  

PubMed

Enzymatic hydrolysis of high-solid biomass (>10% w/w dry mass) has become increasingly important as a key step in the production of second-generation bioethanol. To this end, development of quantitative real-time assays is desirable both for empirical optimization and for detailed kinetic analysis. In the current work, we have investigated the application of isothermal calorimetry to study the kinetics of enzymatic hydrolysis of two substrates (pretreated corn stover and Avicel) at high-solid contents (up to 29% w/w). It was found that the calorimetric heat flow provided a true measure of the hydrolysis rate with a detection limit of about 500 pmol glucose s(-1). Hence, calorimetry is shown to be a highly sensitive real-time method, applicable for high solids, and independent on the complexity of the substrate. Dose-response experiments with a typical cellulase cocktail enabled a multidimensional analysis of the interrelationships of enzyme load and the rate, time, and extent of the reaction. The results suggest that the hydrolysis rate of pretreated corn stover is limited initially by available attack points on the substrate surface (<10% conversion) but becomes proportional to enzyme dosage (excess of attack points) at later stages (>10% conversion). This kinetic profile is interpreted as an increase in polymer end concentration (substrate for CBH) as the hydrolysis progresses, probably due to EG activity in the enzyme cocktail. Finally, irreversible enzyme inactivation did not appear to be the source of reduced hydrolysis rate over time. PMID:20803262

Olsen, Søren N; Lumby, Erik; McFarland, Kc; Borch, Kim; Westh, Peter

2011-03-01

292

DMSO-Induced Dehydration of DPPC Membranes Studied by X-ray Diffraction, Small-Angle Neutron Scattering, and Calorimetry  

E-print Network

The influence of dimethyl sulfoxide (DMSO) on membrane thickness, multilamellar repeat distance, and phase transitions of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) was investigated by X-ray diffraction and small-angle neutron scattering (SANS). The differential scanning calorimetry (DSC) study of water freezing and ice melting was performed in the ternary DPPC /DMSO /water and binary DMSO /water systems. The methods applied demonstrated the differences in membrane structure in three sub-regions of the DMSO mole fraction (X_dmso): from 0.0 to 0.3 for the first, from 0.3 to 0.8 for the second, and from 0.9 to 1.0 for the third sub-region. The thickness of the intermembrane solvent at T =20C decreases from 14.4 +/- 1.8 A at X_dmso =0.0 to 7.8 +/- 1.8 A at X_dmso =0.1. The data were used to determine the number of free water molecules in the intermembrane space in the presence of DMSO. The results for 0.0 dehydration of the intermembrane space.

M. A. Kiselev; P. Lesieur; A. M. Kisselev; C. Grabielle-Madelmond; M. Ollivon

2001-08-12

293

Operation Manual for the TA Instruments DSC Q-100 and Q-20: Temperature Range: -90C 400C  

E-print Network

Operation Manual for the TA Instruments DSC Q-100 and Q-20: Temperature Range: -90°C ­ 400°C Sample and the temperature range that is used are dependent upon the limits of the DSC (-90°C ­ 400°C) and the sample

Alpay, S. Pamir

294

Calorimetry exchange program. Quarterly data report, 1st quarter 1992  

SciTech Connect

The goals of the Calorimetry Sample Exchange Program are: (1) Discuss measurement differences, (2) Review and improve analytical measurements and methods, (3) Discuss new measurement capabilities, (4) Provide data to DOE on measurement capabilities to evaluate shipper-receiver differences, (5) Provide characterized or standard materials as necessary for exchange participants, (6) Provide a measurement control program for plutonium analysis. A sample of PuO{sub 2} powder is available at each participating site for NDA measurement, including either or both calorimetry and high-resolution gamma-ray spectroscopy, the elements which are typically combined to provide a calorimetric assay of plutonium. The facilities measure the sample as frequently and to the level of precision which they desire, and then submit the data to the Exchange for analysis. Statistical tests are used to evaluate the data and to determine if there are significant differences from accepted values for the exchange sample or from data previously reported by that facility. This information is presented, in the form of a quarterly report, intended for use by Exchange participants in measurement control programs, or to indicate when bias corrections may be appropriate. No attempt, however, has been made to standardize methods or frequency of data collection, calibration, or operating procedures. Direct comparisons between laboratories may, therefore, be misleading since data have not been collected to the same precision or for the same time periods. A meeting of the participants of the Calorimetry Exchange is held annually at EG&G Mound Applied Technologies. The purposes of this meeting are to discuss measurement differences, problems, and new measurement capabilities, and to determine the additional activities needed to fulfill the goals of the Exchange.

Barnett, T.M.

1996-07-01

295

Calorimetry exchange program quarterly data report, first quarter CY93  

SciTech Connect

The goals of the Calorimetry Sample Exchange Program are: Discuss measurement differences; Review and improve analytical measurements and methods; Discuss new measurement capabilities; Provide data to DOE on measurement capabilities to evaluate shipper-receiver differences; Provide characterized or standard materials as necessary for exchange participants; and Provide a measurement control program for plutonium analysis. A sample of Plutonium Dioxide powder is available at each participating site for NDA measurement, including either or both calorimetry and high-resolution gamma-ray spectroscopy, the elements which are typically combined to provide a calorimetric assay of plutonium. The facilities measure the sample as frequently and to the level of precision which they desire, and then submit the data to the Exchange for analysis. The data report includes summary tables for each measurement and charts showing the performance of each laboratory. Comparisons are made to the accepted values for the exchange sample and to data previously reported by that laboratory. This information is presented, in the form of quarterly and annual reports, intended for use by Exchange participants in measurement control programs, or to indicate when bias corrections may be appropriate. No attempt, however, has been made to standardize methods or frequency of data collection, calibration, or operating procedures. Direct comparisons between laboratories may, therefore, be misleading since data have not been collected to the same precision or for the same time periods. A meeting of the participants of the Calorimetry Exchange is held annually at EG&G Mound Applied Technologies. The purposes of this meeting are to discuss measurement differences, problems, and new measurement capabilities, and to determine the additional activities needed to fulfill the goals of the Exchange. This quarterly report provides data for the first quarter of 1993.

Barnett, T.M.

1993-12-31

296

Calorimetry exchange program. Quarterly data report, 2nd quarter 1992  

SciTech Connect

The goals of the Calorimetry Sample Exchange Program are: (1) Discuss measurement differences, (2) Review and improve analytical measurements and methods, (3) Discuss new measurement capabilities, (4) Provide data to DOE on measurement capabilities to evaluate shipper-receiver differences, (5) Provide characterized or standard materials as necessary for exchange participants, (6) Provide a measurement control program for plutonium analysis. A sample of PuO{sub 2} powder is available at each participating site for NDA measurement, including either or both calorimetry and high-resolution gamma-ray spectroscopy, the elements which are typically combined to provide a calorimetric assay of plutonium. The facilities measure the sample as frequently and to the level of precision which they desire, and then submit the data to the Exchange for analysis. Statistical tests are used to evaluate the data and to determine if there are significant differences from accepted values for the exchange sample or from data previously reported by that facility. This information is presented, in the form of a quarterly report, intended for use by Exchange participants in measurement control programs, or to indicate when bias corrections may be appropriate. No, attempt, however, has been made to standardize methods or frequency of data collection, calibration, or operating procedures. Direct comparisons between laboratories may, therefore, be misleading since data have not been collected to the same precision or for the same time periods. A meeting of the participants of the Calorimetry Exchange is held annually at EG&G Mound Applied Technologies. The purposes of this meeting are to discuss measurement differences, problems, and new measurement capabilities, and to determine the additional activities needed to fulfill the goals of the Exchange.

Barnett, T.M.

1996-07-01

297

Calorimetry Exchange Program. Quarterly data report, 3rd Quarter 1991  

SciTech Connect

The goals of the Calorimetry Sample Exchange Program are: (1) Discuss measurement differences, (2) Review and improve analytical measurements and methods, (3) Discuss new measurement capabilities, (4) Provide data to DOE on measurement capabilities to evaluate shipper-receiver differences, (5) Provide characterized or standard materials as necessary for exchange participants, (6) Provide a measurement control program for plutonium analysis. A sample of PuO{sub 2} powder is available at each participating site for NDA measurement, including either or both calorimetry and high-resolution gamma-ray spectroscopy, the elements which are typically combined to provide a calorimetric assay of plutonium. The facilities measure the sample as frequently and to the level of precision which they desire, and then submit the data to the Exchange for analysis. Statistical tests are used to evaluate the data and to determine if there are significant differences from accepted values for the exchange sample or from data previously reported by that facility. This information is presented, in the form of a quarterly report, intended for use by Exchange participants in measurement control programs, or to indicate when bias corrections may be appropriate. No attempt, however, has been made to standardize methods or frequency of data collection, calibration, or operating procedures. Direct comparisons between laboratories may, therefore, be misleading since data have not been collected to the same precision or for the same time periods. A meeting of the participants of the Calorimetry Exchange is held annually at EG&G Mound Applied Technologies. The purposes of this meeting are to discuss measurement differences, problems, and new measurement capabilities, and to determine the additional activities needed to fulfill the goals of the Exchange.

McClelland, T.M.

1996-07-01

298

Calorimetry exchange program. Quarterly data report, 1st quarter 1991  

SciTech Connect

The goals of the Calorimetry Sample Exchange Program are: (1) Discuss measurement differences, (2) Review and improve analytical measurements and methods, (3) Discuss new measurement capabilities, (4) Provide data to DOE on measurement capabilities to evaluate shipper-receiver differences, (5) Provide characterized or standard materials as necessary for exchange participants, (6) Provide a measurement control program for plutonium analysis. A sample of PuO{sub 2} powder is available at each participating site for NDA measurement, including either or both calorimetry and high-resolution gamma-ray spectroscopy, the elements which are typically combined to provide a calorimetric assay of plutonium. The facilities measure the sample as frequently and to the level of precision which they desire, and then submit the data to the Exchange for analysis. Statistical tests are used to evaluate the data and to determine if there are significant differences from accepted values for the exchange sample or from data previously reported by that facility. This information is presented, in the form of a quarterly report, intended for use by Exchange participants in measurement control programs, or to indicate when bias corrections-may be appropriate. No attempt, however, has been made to standardize methods or frequency of data collection, calibration, or operating procedures. Direct comparisons between laboratories may, therefore, be misleading since data have not been collected to the same precision or for the same time periods. A meeting of the participants of the Calorimetry Exchange is held annually at EG&G Mound Applied Technologies. The purposes of this meeting are to discuss measurement differences, problems, and new measurement capabilities, and to determine the additional activities needed to fulfill the goals of the Exchange.

McClelland, T.M.

1996-07-01

299

Calorimetry exchange program annual data report for 1992  

SciTech Connect

The goals of the Calorimetry Sample Exchange Program are: discuss measurement differences; review and improve analytical measurements and methods; discuss new measurement capabilities; provide data to DOE on measurement capabilities to evaluate shipper-receiver differences; provide characterized or standard materials as necessary for exchange participants; and provide a measurement control program for plutonium analysis. A sample of PuO{sub 2} powder is available at each participating site for NDA measurement, including either or both calorimetry and high-resolution gamma-ray spectroscopy, the elements which are typically combined to provide a calorimetric assay of plutonium. The facilities measure the sample as frequently and to the level of precision which they desire, and then submit the data to the Exchange for analysis. The data report includes summary tables for each measurement and charts showing the performance of each laboratory. Comparisons are made to the accepted values for the exchange sample and to data previously reported by that laboratory. This information is presented, in the form of quarterly and annual reports, intended for use by Exchange participants in measurement control programs, or to indicate when bias corrections may be appropriate. No attempt, however, has been made to standardize methods or frequency of data collection, calibration, or operating procedures. Direct comparisons between laboratories may, therefore, be misleading since data have not been collected to the same precision or for the same time periods. A meeting of the participants of the Calorimetry Exchange is held annually at EG&G Mound Applied Technologies. The purposes of this meeting are to discuss measurement differences, problems, and new measurement capabilities, and to determine the additional activities needed to fulfill the goals of the Exchange. This document provides data for 1992.

Barnett, T.M.

1992-12-31

300

Calorimetry exchange program quarterly data report, fourth quarter CY92  

SciTech Connect

The goals of the Calorimetry Sample Exchange Program are: (1) discuss measurement differences (2) review and improve analytical measurements and methods (3) discuss new measurement capabilities (4) provide data to DOE on measurement capabilities to evaluate shipper- receiver differences (5) provide characterized or standard materials as necessary for exchange participants (6) provide a measurement control program for plutonium analysis A sample Of PUO2 powder is available at each participating site for NDA measurement, including either or both calorimetry and high-resolution gamma-ray spectroscopy, the elements which are typically combined to provide a calorimetric assay of plutonium. The facilities measure the sample as frequently and to the level of precision which they desire, and then submit the data to the Exchange for analysis. The data report includes summary tables for each measurement and charts showing the performance of each laboratory. Comparisons are made to the accepted values for the exchange sample and to data previously reported by that laboratory. This information is presented, in the form of quarterly reports as this document provides and as annual reports, intended for use by Exchange participants in measurement control programs, or to indicate when bias corrections may be appropriate. No attempt, however, has been made to standardize methods or frequency of data collection, calibration, or operating procedures. Direct comparisons between laboratories may, therefore, be misleading since data have not been collected to the same precision or for the same time periods. A meeting of the participants of the Calorimetry Exchange is held annually at EG&G Mound Applied Technologies. The purposes of this meeting are to discuss measurement differences, problems, and new measurement capabilities, and to determine the additional activities needed to fulfill the goals of the Exchange.

Barnett, T.M.

1992-12-31

301

Subunit Architecture of the Golgi Dsc E3 Ligase Required for Sterol Regulatory Element-binding Protein (SREBP) Cleavage in Fission Yeast*  

PubMed Central

The membrane-bound sterol regulatory element-binding protein (SREBP) transcription factors regulate lipogenesis in mammalian cells and are activated through sequential cleavage by the Golgi-localized Site-1 and Site-2 proteases. The mechanism of fission yeast SREBP cleavage is less well defined and, in contrast, requires the Golgi-localized Dsc E3 ligase complex. The Dsc E3 ligase consists of five integral membrane subunits, Dsc1 through Dsc5, and resembles membrane E3 ligases that function in endoplasmic reticulum-associated degradation. Using immunoprecipitation assays and blue native electrophoresis, we determined the subunit architecture for the complex of Dsc1 through Dsc5, showing that the Dsc proteins form subcomplexes and display defined connectivity. Dsc2 is a rhomboid pseudoprotease family member homologous to mammalian UBAC2 and a central component of the Dsc E3 ligase. We identified conservation in the architecture of the Dsc E3 ligase and the multisubunit E3 ligase gp78 in mammals. Specifically, Dsc1-Dsc2-Dsc5 forms a complex resembling gp78-UBAC2-UBXD8. Further characterization of Dsc2 revealed that its C-terminal UBA domain can bind to ubiquitin chains but that the Dsc2 UBA domain is not essential for yeast SREBP cleavage. Based on the ability of rhomboid superfamily members to bind transmembrane proteins, we speculate that Dsc2 functions in SREBP recognition and binding. Homologs of Dsc1 through Dsc4 are required for SREBP cleavage and virulence in the human opportunistic pathogen Aspergillus fumigatus. Thus, these studies advance our organizational understanding of multisubunit E3 ligases involved in endoplasmic reticulum-associated degradation and fungal pathogenesis. PMID:23760507

Lloyd, S. Julie-Ann; Raychaudhuri, Sumana; Espenshade, Peter J.

2013-01-01

302

Parallel nano-Differential Scanning Calorimetry: A New Device for Combinatorial Analysis of Complex nano-Scale Material Systems  

E-print Network

1 Parallel nano-Differential Scanning Calorimetry: A New Device for Combinatorial Analysis to combinatorial calorimetry greatly expedites the analysis of nano-scale material thermal properties. A power-compensation differential scanning calorimetry measurement is described. The scanning calorimetry capability of the Pn

303

The Pandora Software Development Kit for Particle Flow Calorimetry  

NASA Astrophysics Data System (ADS)

Pandora is a robust and efficient framework for developing and running pattern-recognition algorithms. It was designed to perform particle flow calorimetry, which requires many complex pattern-recognition techniques to reconstruct the paths of individual particles through fine granularity detectors. The Pandora C++ software development kit (SDK) consists of a single library and a number of carefully designed application programming interfaces (APIs). A client application can use the Pandora APIs to pass details of tracks and hits/cells to the Pandora framework, which then creates and manages named lists of self-describing objects. These objects can be accessed by Pandora algorithms, which perform the pattern-recognition reconstruction. Development with the Pandora SDK promotes the creation of small, re-usable algorithms containing just the kernel of a specific operation. The algorithms are configured via XML and can be nested to perform complex reconstruction tasks. As the algorithms only access the Pandora objects in a controlled manner, via the APIs, the framework can perform most book-keeping and memory-management operations. The Pandora SDK has been fully exploited in the implementation of PandoraPFA, which uses over 60 algorithms to provide the state of the art in particle flow calorimetry for ILC and CLIC.

Marshall, J. S.; Thomson, M. A.

2012-12-01

304

Calorimetry exchange program. Annual data report, Calendar Year 1993  

SciTech Connect

A sample of PuO{sub 2} powder is available at each participating site for NDA measurement, including either or both calorimetry and high-resolution gamma-ray spectroscopy, the elements which are typically combined to provide a calorimetric assay of plutonium. The facilities measure the sample as frequently and to the level of precision which they desire, and then submit the data to the Exchange for analysis. The data report includes summary tables for each measurement and charts showing the performance of each laboratory. Comparisons are made to the accepted values for the exchange sample and to data previously reported by that laboratory. This information is presented, in the form of quarterly and annual reports, intended for use by Exchange participants in measurement control programs, or to indicate when bias corrections may be appropriate. No attempt, however, has been made to standardize methods or frequency of data collection, calibration, or operating procedures. Direct comparisons between laboratories may, therefore, be misleading since data have not been collected to the same precision or for the same time periods. A meeting of the participants of the Calorimetry Exchange is held annually at EG&G Mound Applied Technologies. The purposes of this meeting are to discuss measurement differences, problems, and new measurement capabilities, and to determine the additional activities needed to fulfill the goals of the Exchange.

Barnett, T.M.

1996-08-01

305

Tetraether bolaform amphiphiles as models of archaebacterial membrane lipids: Synthesis, differential scanning calorimetry, and monolayer studies  

SciTech Connect

Four racemic tetraether lipids containing a single 1,[omega]-polymethylene chain ([omega] = 16, 20) bridging two glycerophosphate headgroups (bolaform amphiphiles) have been synthesized. These materials have been characterized at the air-water interface by monolayer balance methods and in buffered solution by differential scanning calorimetry (DSC) and negative stain transmission electron microscopy (TEM). Molecular areas in excess of 100 [angstrom][sup 2]/molecule at 40 mN/m[sup 2] were observed for all bolaamphiphiles studied, suggesting a U-shaped molecular conformation that places both phosphate headgroups in the water subphase. Aqueous dispersions of these lipids have thermal and morphological properties that depend on molecular structure and solution pH. Phase transition temperatures (T[sub c]) of the structural isomers, 2,2[prime]-di-O-decyl-1, 1[prime]-O-eicosamethylene-rac-diglycero-3,3[prime]-diphosphate (PS20) and 1,1[prime]-di-O-decyl-2,2[prime]-O-eicosamethylene-3,3[prime]-diphosphate (SS20), were 49 and 38 [degrees]C, respectively, at pH 2.5. A reduction in the observed T[sub c] of [approximately] 14 [degrees]C occurred when the pH was raised to 8.1. The closely related structural analogue, 1,1[prime]-O-eicosamethylene-2-O-eicosyl-rac-diglycero-3,2[prime], 3[prime]-diphosphate (PA20), has a T[sub c] 85 [degrees]C. No phase transition was observed above 5 [degrees]C for 2,2[prime]-O-dioctyl-1,1 [prime]-O-hexadecylmethylene-rac-diglycero-3, 3[prime]-disphosphoric acid (PS16). Multilamellar structures with hydrocarbon-region spacings of 24-30 [angstrom] and overall lengths approaching 0.3 [mu]m were observed by negative stain electron microscopy. The observed lamellae distance is in good agreement with the membrane thickness expected for a bolaamphiphile in its all-anti conformation. 56 refs., 8 figs., 1 tab.

Kim, J.M.; Thompson, D.H. (Oregon Graduate Inst. of Science and Technology, Beaverton, OR (United States))

1992-02-01

306

Kinetics of the thermal degradation of Erica arborea by DSC: Hybrid kinetic method  

E-print Network

The scope of this work was the determination of kinetic parameters of the thermal oxidative degradation of a Mediterranean scrub using a hybrid method developed at the laboratory. DSC and TGA were used in this study under air sweeping to record oxidative reactions. Two dominating and overlapped exothermic peaks were recorded in DSC and individualized using an experimental and numerical separation. This first stage allowed obtaining the enthalpy variation of each exothermic phenomenon. In a second time, a model free method was applied on each isolated curve to determine the apparent activation energies. A reactional kinetic scheme was proposed for the global exotherm composed of two independent and consecutive reactions. In fine mean values of enthalpy variation and apparent activation energy previously determined were injected in a model fitting method to obtain the reaction order and the preexponential factor of each oxidative reaction. We plan to use these data in a sub-model to be integrated in a wildland ...

Cancellieri, Dominique; Rossi, Jean Louis; 10.1016/j.tca.2005.07.013

2008-01-01

307

Study on the interaction of amino phosphine ester derivatives with DNA by spectroscopy, modeling and calorimetry  

NASA Astrophysics Data System (ADS)

The binding properties of amino phosphate ester derivatives, compound 1 and 2 with calf thymus DNA (CT-DNA) were investigated by UV spectra, fluorescence spectra, molecular modeling and isothermal titration calorimetry (ITC). The intrinsic binding constants Kb of compound 1 and 2 with CT-DNA were determined by fluorescence spectroscopy and ITC, respectively. The results indicated that the two compounds bind to CT-DNA with different binding affinity, which is in the order of compound 1 > compound 2. At the same time, fluorescence spectra suggested that the mechanism of the binding of the two compounds to CT-DNA is a static enhancing type. According to the ethidium bromide displacement experiments, UV spectra, molecular modeling and ITC studies, it can be concluded that compound 1 and 2 are intercalators that can slide into the G-C rich region of CT-DNA. Furthermore, ITC data showed that compound/DNA binding is enthalpy controlled.

Lu, Yan; Wang, Gongke; Tang, Wen; Hao, Xiaoxiao; Xu, Meihua; Li, Xiang

2011-11-01

308

Simulation and Analysis of Differential Scanning Calorimetry Output: Protein Unfolding Studies  

NASA Astrophysics Data System (ADS)

High sensitivity differential scanning calorimetry ( HSDSC ) is a powerful and increasingly used technique for the study of molecular energetics in relation to biopolymers (e.g. proteins and nucleic acids ) or biomacromolecular assemblies ( e.g. liposomes ). HSDSC is, for example, the only method which allows thermodynamic parameters to be obtained directly for protein unfolding. The thermodynamic basis for HSDSC signals obtained for the equilibrium unfolding of proteins as well as the formalism for generating simulations of HSDSC outputs for protein unfolding are discussed. This will allow students ( studying biophysical chemistry, biochemistry, biophysics, molecular biology and allied subjects at undergraduate and postgraduate level ) to obtain an understanding of the type of data analysis required for HSDSC experiments on proteins.

Chowdhry, Babur; Leharne, Stephen

1997-02-01

309

Detectors for Linear Colliders: Calorimetry at a Future Electron-Positron Collider (3/4)  

SciTech Connect

Calorimetry will play a central role in determining the physics reach at a future e+e- collider. The requirements for calorimetry place the emphasis on achieving an excellent jet energy resolution. The currently favoured option for calorimetry at a future e+e- collider is the concept of high granularity particle flow calorimetry. Here granularity and a high pattern recognition capability is more important than the single particle calorimetric response. In this lecture I will describe the recent progress in understanding the reach of high granularity particle flow calorimetry and the related R&D; efforts which concentrate on test beam demonstrations of the technological options for highly granular calorimeters. I will also discuss alternatives to particle flow, for example the technique of dual readout calorimetry.

None

2010-02-17

310

Towards high-performance DPP-based sensitizers for DSC applications.  

PubMed

A novel, asymmetric DPP bridge/core was synthesized and tested in DSC devices. By desymmetrising the DPP core/bridge, a remarkable IPCE of >80% and a maximum power conversion efficiency of 7.7% were achieved. With the use of a wide-bandgap co-sensitizer, 8.6% PCE was realized under standard AM1.5G sunlight. PMID:23022986

Yum, Jun-Ho; Holcombe, Thomas W; Kim, Yongjoo; Yoon, Junghyun; Rakstys, Kasparas; Nazeeruddin, Mohammad K; Grätzel, Michael

2012-11-11

311

Application of dsc to study crystallization kinetics of polypropylene containing fillers  

Microsoft Academic Search

The present work is concerned with the comparison of nucleating efficiency of various organic and inorganic fillers of isotactic\\u000a polypropylene: talc, chalk, wood flour, nano clay particles, carbon black, chitosan in the form of powder of the same content\\u000a equal to 5 mass%. The kinetics of isothermal crystallization of isotactic polypropylene in the composite systems was evaluated\\u000a by using DSC.

M. Mucha; Z. Królikowski

2003-01-01

312

A fully automated method for quantitative cerebral hemodynamic analysis using DSC-MRI  

PubMed Central

Dynamic susceptibility contrast (DSC)-based perfusion analysis from MR images has become an established method for analysis of cerebral blood volume (CBV) in glioma patients. To date, little emphasis has, however, been placed on quantitative perfusion analysis of these patients, mainly due to the associated increased technical complexity and lack of sufficient stability in a clinical setting. The aim of our study was to develop a fully automated analysis framework for quantitative DSC-based perfusion analysis. The method presented here generates quantitative hemodynamic maps without user interaction, combined with automatic segmentation of normal-appearing cerebral tissue. Validation of 101 patients with confirmed glioma after surgery gave mean values for CBF, CBV, and MTT, extracted automatically from normal-appearing whole-brain white and gray matter, in good agreement with literature values. The measured age- and gender-related variations in the same parameters were also in agreement with those in the literature. Several established analysis methods were compared and the resulting perfusion metrics depended significantly on method and parameter choice. In conclusion, we present an accurate, fast, and automatic quantitative perfusion analysis method where all analysis steps are based on raw DSC data only. PMID:20087370

Bj?rnerud, Atle; Emblem, Kyrre E

2010-01-01

313

Thermodynamic properties of aqueous PEO-PPO-PEO micelles with added methylparaben determined by differential scanning calorimetry.  

PubMed

DSC experiments were performed on aqueous solutions of PEO-PPO-PEO (P105) amphiphiles in the low concentration regime (0-1%) to resolve the critical micelle concentration (cmc) both neat and co-formulated with methylparaben (MP). Further work was done at 10% amphiphilic copolymer concentrations and co-formulated with MP to resolve the variations in enthalpy. The compensation temperature, T(compensation), was determined from the analyses for neat P105 as 293.9 K; adding MP raises this to 328.43 K. PMID:23474225

Thompson, Andre Lamont; Love, Brian James

2013-05-15

314

University of Cambridge, Materials Science & Metallurgy H. K. D. H. Bhadeshia Differential Scanning Calorimetry  

E-print Network

or cooled at a controlled rate. There are two types of DSC systems in common use (Fig. 1). In power­compensation DSC the temperatures of the sample and reference are controlled independently using separate, identical furnaces. The temperatures of the sample and reference are made identical by varying the power

Cambridge, University of

315

Ind Cd ADAP AENR ALL ATH R CIS CSH DPL DSC ECHEK ENVER FALL GRD HS ID LIB NLATE NOB PAYPL REF TRN  

E-print Network

Srv Ind Cd ADAP AENR ALL ATH CEN R CIS CSH DPL DSC ECHEK ENVER FALL GRD HS ID LIB NLATE NOB PAYPL of REF Refunds ­ Issuance of DSC Discounted Special Events TRN Transcript ECHEK Block Electronic Checks

Sibille, Etienne

316

Using modulated DSC to investigate the origin of multiple thermal transitions in frozen 10% sucrose solutions  

Microsoft Academic Search

Modulated differential scanning calorimetry (MDSC) was used to investigate the effect of annealing on multiple thermal transitions in frozen aqueous sucrose solutions. Two thermal transitions were detected from the reversing heat flow. Here, to maintain consistency with terminology used in the practice of freeze-drying [1], the higher temperature is denoted, T?g, and the lower transition is given the symbol, T?g.

Nathaniel Milton; Daniel Rigsbee; Dinesh S. Mishra; Leonard C. Thomas; Michael J. Pikal

2006-01-01

317

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

318

Gelatinisation of starch: a combined SAXS\\/WAXS\\/DSC and SANS study  

Microsoft Academic Search

Using a combination of techniques, small- and wide-angle X-ray scattering, differential scanning calorimetry and small-angle neutron scattering, it has been possible to follow the stages that occur during gelatinisation in excess water for a range of starches. It is found that water enters the amorphous growth rings first, and that this is where all the swelling is concentrated. The periodicity

Paul J Jenkins; Athene M Donald

1998-01-01

319

Lipid migration in two-phase chocolate systems investigated by NMR and DSC  

Microsoft Academic Search

The migration of lipids in two-phase chocolate systems (i.e. lauric acid+chocolate and peanut butter+chocolate) was analyzed by magnetic resonance and differential scanning calorimetry. Kinetics of fat migration was evaluated and the diffusion coefficient of lauric acid in chocolate was found to be dependent on migration time. This may be due to the capillary nature of fat migration in chocolate. Fat

Peggy Walter; Paul Cornillon

2002-01-01

320

Hadronic Shower Development in Iron-Scintillator Tile Calorimetry  

E-print Network

The lateral and longitudinal profiles of hadronic showers detected by a prototype of the ATLAS Iron-Scintillator Tile Hadron Calorimeter have been investigated. This calorimeter uses a unique longitudinal configuration of scintillator tiles. Using a fine-grained pion beam scan at 100 GeV, a detailed picture of transverse shower behavior is obtained. The underlying radial energy densities for four depth segments and for the entire calorimeter have been reconstructed. A three-dimensional hadronic shower parametrization has been developed. The results presented here are useful for understanding the performance of iron-scintillator calorimeters, for developing fast simulations of hadronic showers, for many calorimetry problems requiring the integration of a shower energy deposition in a volume and for future calorimeter design.

Tilecal Atlas Collaboration

1999-04-29

321

Hadronic Shower Development in Tile Iron-Scintillator Calorimetry  

E-print Network

The lateral and longitudinal profiles of hadronic showers detected by a prototype of the ATLAS Iron-Scintillator Tile Hadron Calorimeter have been investigated. This calorimeter uses a unique longitudinal configuration of scintillator tiles. Using a fine-grained pion beam scan at 100 GeV, a detailed picture of transverse shower behavior is obtained. The underlying radial energy densities for four depth segments and for the entire calorimeter have been reconstructed. A three-dimensional hadronic shower parametrization has been developed. The results presented here are useful for understanding the performance of iron-scintillator calorimeters, for developing fast simulations of hadronic showers, for many calorimetry problems requiring the integration of a shower energy deposition in a volume and for future calorimeter design.

Yuri A. Kulchitsky

1999-10-07

322

Hadronic shower development in Iron-Scintillator Tile Calorimetry  

NASA Astrophysics Data System (ADS)

The lateral and longitudinal profiles of hadronic showers detected by a prototype of the ATLAS Iron-Scintillator Tile Hadron Calorimeter have been investigated. This calorimeter presents a unique longitudinal configuration of scintillator tiles. Using a fine-grained pion beam scan at 100 GeV, a detailed picture of transverse shower behaviour is obtained. The underlying radial energy densities for the four depth segments and for the entire calorimeter have been reconstructed. A three-dimensional hadronic shower parametrisation has been developed. The results presented here are useful for understanding the performance of iron-scintillator calorimeters, for developing fast simulations of hadronic showers, for many calorimetry problems requiring the integration of a shower energy deposition in a volume and for future calorimeters design.

Amaral, P.; Amorim, A.; Anderson, K.; Barreira, G.; Benetta, R.; Berglund, S.; Biscarat, C.; Blanchot, G.; Blucher, E.; Bogush, A.; Bohm, C.; Boldea, V.; Borisov, O.; Bosman, M.; Bromberg, C.; Budagov, J.; Burdin, S.; Caloba, L.; Carvalho, J.; Casado, P.; Castillo, M. V.; Cavalli-Sforza, M.; Cavasinni, V.; Chadelas, R.; Chirikov-Zorin, I.; Chlachidze, G.; Cobal, M.; Cogswell, F.; Colaço, F.; Cologna, S.; Constantinescu, S.; Costanzo, D.; Crouau, M.; Daudon, F.; David, J.; David, M.; Davidek, T.; Dawson, J.; De, K.; Del Prete, T.; De Santo, A.; Di Girolamo, B.; Dita, S.; Dolejsi, J.; Dolezal, Z.; Downing, R.; Efthymiopoulos, I.; Engström, M.; Errede, D.; Errede, S.; Evans, H.; Fenyuk, A.; Ferrer, A.; Flaminio, V.; Gallas, E.; Gaspar, M.; Gil, I.; Gildemeister, O.; Glagolev, V.; Gomes, A.; Gonzalez, V.; González De La Hoz, S.; Grabski, V.; Grauges, E.; Grenier, P.; Hakopian, H.; Haney, M.; Hansen, M.; Hellman, S.; Henriques, A.; Hebrard, C.; Higon, E.; Holmgren, S.; Huston, J.; Ivanyushenkov, Yu.; Jon-And, K.; Juste, A.; Kakurin, S.; Karapetian, G.; Karyukhin, A.; Kopikov, S.; Kukhtin, V.; Kulchitsky, Y.; Kurzbauer, W.; Kuzmin, M.; Lami, S.; Lapin, V.; Lazzeroni, C.; Lebedev, A.; Leitner, R.; Li, J.; Lomakin, Yu.; Lomakina, O.; Lokajicek, M.; Lopez Amengual, J. M.; Maio, A.; Malyukov, S.; Marroquin, F.; Martins, J. P.; Mazzoni, E.; Merritt, F.; Miller, R.; Minashvili, I.; Miralles, Ll.; Montarou, G.; Munar, A.; Nemecek, S.; Nessi, M.; Onofre, A.; Orteu, S.; Park, I. C.; Pallin, D.; Pantea, D.; Paoletti, R.; Patriarca, J.; Pereira, A.; Perlas, J. A.; Petit, P.; Pilcher, J.; Pinhão, J.; Poggioli, L.; Price, L.; Proudfoot, J.; Pukhov, O.; Reinmuth, G.; Renzoni, G.; Richards, R.; Roda, C.; Romance, J. B.; Romanov, V.; Ronceux, B.; Rosnet, P.; Rumyantsev, V.; Russakovich, N.; Sanchis, E.; Sanders, H.; Santoni, C.; Santos, J.; Sawyer, L.; Says, L.-P.; Seixas, J. M.; Selldèn, B.; Semenov, A.; Shchelchkov, A.; Shochet, M.; Simaitis, V.; Sissakian, A.; Solodkov, A.; Solovianov, O.; Sonderegger, P.; Sosebee, M.; Soustruznik, K.; Spanó, F.; Stanek, R.; Starchenko, E.; Stephens, R.; Suk, M.; Tang, F.; Tas, P.; Thaler, J.; Tokar, S.; Topilin, N.; Trka, Z.; Turcot, A.; Turcotte, M.; Valkar, S.; Varandas, M. J.; Vartapetian, A.; Vazeille, F.; Vichou, I.; Vinogradov, V.; Vorozhtsov, S.; Wagner, D.; White, A.; Wolters, H.; Yamdagni, N.; Yarygin, G.; Yosef, C.; Zaitsev, A.; Zdrazil, M.; Zuñiga, J.

2000-03-01

323

NEUTRON-ENHANCED CALORIMETRY FOR HADRONS (NECH): FINAL REPORT  

SciTech Connect

We present the results of a project to apply scintillator technology recently developed at Louisiana Tech University to hadronic calorimetry. In particular, we developed a prototype calorimeter module incorporating scintillator embedded with metal oxide nanoparticles as the active layers. These metal oxide nanoparticles of gadolinium oxide, have high cross-sections for interactions with slow neutrons. As a part fo this research project, we have developed a novel method for producing plastic scintillators with metal oxide nanoparticles evenly distributed through the plastic without aggregation.We will test the performance of the calorimeter module in test beam and with a neutron source, in order to measure the response to the neutron component of hadronic showers. We will supplement our detector prototyping activities with detailed studies of the effect of neutron component on the resolution of hadronic energy measurements, particular in the next generation of particle flow calorimeters.

Andrew Stroud, Lee Sawyer

2012-08-31

324

ROC chips for imaging calorimetry at the International Linear Collider  

NASA Astrophysics Data System (ADS)

Imaging calorimetry at the International Linear Collider requires highly granular and innovative detectors. Technological prototypes have been built and tested under the CALICE collaboration framework and FP6 EUDET, FP7 AIDA European programs. These prototypes are readout by multi-channel chips named SKIROC2, SPIROC2 and HARDROC2, designed by the IN2P3 OMEGA group in AMS SiGe 350 nm technology. In this presentation, the ASIC architectures and test results on test bench and at system level will be described as well as first results of test bench measurements performed on HARDROC3, which is the first of the ``3rd generation'' chip to be submitted and where the 64 channels are handled independently to perform zero suppress on chip.

Callier, S.; Cizel, J.-B.; Dulucq, F.; de La Taille, C.; Martin-Chassard, G.; Seguin-Moreau, N.

2014-02-01

325

Photolyses of mammalian carboxy-hemoglobin studied by photoacoustic calorimetry  

NASA Astrophysics Data System (ADS)

The enthalpy and conformational volume changes in the photolyses of carboxy-hemoglobin (HbCO) of human, bovine, pig, horse and rabbit are investigated by photoacoustic calorimetry. Considering the time scales of the exciting laser pulse and the receiving ultrasound transducers (PVDF films and PZT ceramics), as well as the reaction lifetimes in the photolysis processes of HbCO, the measured results are related to the geminate recombination and tertiary relaxation in photolyses of HbCO. Moreover, the quantum yields of the five mammals are also measured by laser pump-probe technique. The results show that the dynamic parameters, such as enthalpy and conformational volume changes, differ between the processes of the geminate recombination and tertiary relaxation. Also, the dynamic parameters differ among the five mammals although some of them may be consistent with each other.

Zhao, JinYu; Li, JiaHuang; Zhang, Zheng; Zhang, ShuYi; Qu, Min; Fang, JianWen; Hua, ZiChun

2013-07-01

326

Questions and comments -Prof. RNDr. Josef Mlek, DSc., CSc. Jak se v modelovn resp. ve formulaci modelu ci v odvozen algoritmu projev  

E-print Network

Questions and comments - Prof. RNDr. Josef Málek, DSc., CSc. Question 1 Jak se v modelování resp continuum). + divs - b 0 #12;Questions and comments - Prof. RNDr. Josef Málek, DSc., CSc. Question 1 Jak (single continuum). + div q T - b 0 #12;Questions and comments - Prof. RNDr. Josef Málek, DSc., CSc

Cerveny, Vlastislav

327

Response evolution of the CMS ECAL and R&D studies for electromagnetic calorimetry at the High-Luminosity LHC  

E-print Network

While the CMS experiment is currently harvesting LHC collision data at CERN, the performance of its electromagnetic calorimeter (ECAL) is being constantly monitored, and work has started to assess the need for changes to the detector to ensure an adequate performance for High-Luminosity LHC (HL-LHC) running, which is planned for 2022 and beyond. In this paper, results from CMS running, beam tests and laboratory measurements are combined to anticipate the detector performance evolution at the HL-LHC. Further, various R&D studies are illustrated, that will provide a useful choice for electromagnetic calorimetry at the HL-LHC.

Francesca Nessi Tedaldi; for the CMS Collaboration

2012-11-16

328

Isothermal titration calorimetry study of a bistable supramolecular system: reversible complexation of cryptand[2.2.2] with potassium ions.  

PubMed

Isothermal titration calorimetry (ITC) is used to investigate the thermodynamics of the complexation of potassium ions by 1,10-diaza-4,7,13,16,21,24-hexaoxabicyclo[8.8.8]hexacosane (cryptand[2.2.2]) in aqueous solution. By changing the pH of the solution it was possible to trigger the reversible complexation/decomplexation of the cryptand in consecutive in situ experiments and to assess for the first time the use of ITC to monitor the thermodynamics of a bistable system. PMID:24986754

del Rosso, Maria G; Ciesielski, Artur; Colella, Silvia; Harrowfield, Jack M; Samorì, Paolo

2014-09-15

329

Evaluation of heat treated wood swelling by differential scanning calorimetry in relation with chemical composition.  

E-print Network

and Bekhta 2003). Retification® is a mild pyrolysis of wood that takes place under nitrogen atmosphereEvaluation of heat treated wood swelling by differential scanning calorimetry in relation calorimetry ; fiber saturation point ; heat treatment ; swelling ; wood. DOI 10.1515/HF.2004.131 Abstract

Paris-Sud XI, Université de

330

Annual meeting of the Calorimetry Exchange Program: minutes--April 24-25, 1991.  

National Technical Information Service (NTIS)

On April 24-25, 1991, people from seven DOE organizations participated in the annual meeting of the Calorimetry Exchange Program. The meeting featured a review of the statistical analysis of the calorimetry and gamma-ray data submitted to the exchange pro...

1991-01-01

331

Synthesis of dry AgPO3 glass and characterization by Raman, IR and m-DSC  

NASA Astrophysics Data System (ADS)

Glass transition temperature of titled glass apparently vary over a wide range, 163 C< Tg< 254 C depending on the humidity of the ambient environment in which precursors are handled^1. We have examined a set of 4 samples (1(181 C),2(203 C), 3(242.7 C), 4(254 C) with different Tgs indicated in parenthesis, in m-DSC, Raman and IR experiments to elucidate the role of bonded water. Our results show that the glass transition endotherm of sample 4 (dry) is characteristic of a stressed-rigid glass, while that of sample 1 (wet) of a flexible glass. Although Raman scattering of samples 1 and 4 look superficially similar, they are different in details; the Boson peak in sample 4 has a stronger intensity than in sample 1. IR reflectance signal strength in the mid-IR range is weaker for sample 4 than for sample 1, and furthermore differs in details. These results show that presence of water disrupts the P-O-P chain network by replacing bridging O with terminal OH^- ends. And once water is bonded, it is difficult to remove it completely. These results will be compared to previous reports in the field. ^1 D.I.Novita and P.Boolchand Phys. Rev. B (in press) * Supported by NSF grant DMR 04-56472

Novita, D.; Boolchand, P.

2008-03-01

332

Correction for Arterial-Tissue Delay and Dispersion in Absolute Quantitative Cerebral Perfusion DSC MR Imaging  

PubMed Central

The singular value decomposition deconvolution of cerebral tissue concentration-time (C-T) curves with the arterial input function (AIF) is commonly used in dynamic susceptibility contrast (DSC) cerebral perfusion MR imaging. However, it is sensitive to the time discrepancy between the arrival of the bolus in the tissue C-T curve and the AIF signal. This normally causes inaccuracy in the quantitative perfusion maps due to delay and dispersion effects. A comprehensive correction algorithm has been achieved through slice-dependent time-shifting of the AIF, and a delay-dependent dispersion correction model. The correction algorithm was tested in 11 healthy subjects and 3 ischemic stroke patients scanned with a quantitative perfusion pulse sequence at 1.5T. A validation study was performed on 5 patients with confirmed cerebrovascular occlusive disease scanned with MRI and positron emission tomography (PET) at 3.0T. A significant effect (p<0.05) was reported on the quantitative cerebral blood flow and mean transit time measurements (up to 50%). There was no statistically significant effect on the quantitative cerebral blood volume values. The in vivo results were in agreement with the simulation results, as well as previous literature. This minimizes the bias in patient diagnosis due to the existing errors and artifacts in DSC imaging. PMID:22162092

Mouannes-Srour, Jessy J.; Shin, Wanyong; Ansari, Sameer A.; Hurley, Michael C.; Vakil, Parmede; Bendok, Bernard R.; Lee, John L.; Derdeyn, Colin P.; Carroll, Timothy J.

2011-01-01

333

DSC, TGA and dielectric properties of carboxymethyl cellulose/polyvinyl alcohol blends  

NASA Astrophysics Data System (ADS)

Films with different compositions of polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) blends have been prepared using the casting method. Differential scanning calorimetery (DSC), thermogravimetric analysis (TGA) and dielectric spectroscopy of all compositions have been investigated. It was found that PVA and CMC are compatible in the studied range of composition. With increasing CMC content, the thermal stability of PVA increases. Based on DSC and TGA data, the activation energies of all the investigated samples were calculated. The absorption edge ( Ea) was also determined from Ultraviolet-visible (UV-vis) spectra. Dielectric permittivity, loss tangent and ac conductivity of all samples were studied as functions of temperature and frequency. The results show that the dielectric dispersion consists of both dipolar and interfacial polarization. The frequency dependence of the ac conductivity indicates that the correlated barrier hopping (CBH) is the most suitable mechanism for conduction. The polaron binding energy ( UM) was determined. Results of the present system are compared with those of similar materials.

El-Sayed, S.; Mahmoud, K. H.; Fatah, A. A.; Hassen, A.

2011-11-01

334

A Common Origin for Cosmic Explosions Inferred from Fireball Calorimetry  

E-print Network

Past studies suggest that long-duration gamma-ray bursts (GRBs) have a standard energy of E_gamma ~ 10^51 erg in ultra-relativistic ejecta when corrected for asymmetry ("jets"). However, recently a group of sub-energetic bursts, including the peculiar GRB 980425 associated with SN 1998bw (E_gamma ~ 10^48 erg), has been identified. Here we report radio observations of GRB 030329, the nearest burst to date, which allow us to undertake calorimetry of the explosion. Our observations require a two-component explosion: a narrow (5 degrees) ultra-relativistic component responsible for the gamma-rays and early afterglow, and a wide, mildly relativistic component responsible for the radio and optical afterglow beyond 1.5 days. While the gamma-rays are energetically minor, the total energy release, dominated by the wide component, is similar to that of other GRBs. Given the firm link of GRB 030329 with SN 2003dh our result suggests a common origin for cosmic explosions in which, for reasons not understood, the energy in the highest velocity ejecta is highly variable

E. Berger; S. R. Kulkarni; G. Pooley; D. A. Frail; V. McIntyre; R. M. Wark; R. Sari; A. M. Soderberg; D. W. Fox; S. A. Yost; P. A. Price

2003-08-11

335

Volumetric Study on Dioleoylphosphatidylcholine Bilayer by Pressure Perturbation Calorimetry  

NASA Astrophysics Data System (ADS)

We investigated the thermotropic volume behavior of the bilayer membrane of dioleoylphospha-tidylcholine (DOPC), which is a typical unsaturated phospholipid, by means of pressure perturbation calorimetry (PPC) in the temperature range of 6.0-85.6 °C. The thermal expansion coefficient of DOPC in the bilayer membrane was found to monotonically increase from 0.65 × 10-3 K-1 to 1.07 × 10-3 K-1 with increasing temperature. This is slightly small compared to that of dipalmi-toylphosphatidylcholine (DPPC) in the same state at the same temperature. Further, we calculated the specific volume Vsp,L and the specific volume of the hydrocarbon region Vsp,HC for DOPC and DPPC to consider the difference in the packing state of these bilayer membranes. The Vsp,HC value is smaller for DOPC than for DPPC at any temperature above ca. 42 °C, which indicates that the packing state of the DOPC bilayer membrane in the liquid crystalline state is denser than that of the DPPC bilayer membrane in the same state.

Tamai, Nobutake; Tsutsui, Maiko; Goto, Masaki; Matsuki, Hitoshi

336

Characterization of membrane protein interactions by isothermal titration calorimetry.  

PubMed

Understanding the structure, folding, and interaction of membrane proteins requires experimental tools to quantify the association of transmembrane (TM) helices. Here, we introduce isothermal titration calorimetry (ITC) to measure integrin ?IIb?3 TM complex affinity, to study the consequences of helix-helix preorientation in lipid bilayers, and to examine protein-induced lipid reorganization. Phospholipid bicelles served as membrane mimics. The association of ?IIb?3 proceeded with a free energy change of -4.61±0.04kcal/mol at bicelle conditions where the sampling of random helix-helix orientations leads to complex formation. At bicelle conditions that approach a true bilayer structure in effect, an entropy saving of >1kcal/mol was obtained from helix-helix preorientation. The magnitudes of enthalpy and entropy changes increased distinctly with bicelle dimensions, indicating long-range changes in bicelle lipid properties upon ?IIb?3 TM association. NMR spectroscopy confirmed ITC affinity measurements and revealed ?IIb?3 association and dissociation rates of 4500±100s(-1) and 2.1±0.1s(-1), respectively. Thus, ITC is able to provide comprehensive insight into the interaction of membrane proteins. PMID:25178257

Situ, Alan J; Schmidt, Thomas; Mazumder, Parichita; Ulmer, Tobias S

2014-10-23

337

Stiffness transitions in SixSe1x glasses from Raman scattering and temperature-modulated differential scanning calorimetry  

E-print Network

-modulated differential scanning calorimetry D. Selvanathan, W. J. Bresser, and P. Boolchand Department of ECECS 9 April 1999 Temperature-modulated differential scanning calorimetry MDSC measurements on SixSe1 x

Boolchand, Punit

338

A survey of the year 2007 literature on applications of isothermal titration calorimetry.  

PubMed

Elucidation of the energetic principles of binding affinity and specificity is a central task in many branches of current sciences: biology, medicine, pharmacology, chemistry, material sciences, etc. In biomedical research, integral approaches combining structural information with in-solution biophysical data have proved to be a powerful way toward understanding the physical basis of vital cellular phenomena. Isothermal titration calorimetry (ITC) is a valuable experimental tool facilitating quantification of the thermodynamic parameters that characterize recognition processes involving biomacromolecules. The method provides access to all relevant thermodynamic information by performing a few experiments. In particular, ITC experiments allow to by-pass tedious and (rarely precise) procedures aimed at determining the changes in enthalpy and entropy upon binding by van't Hoff analysis. Notwithstanding limitations, ITC has now the reputation of being the "gold standard" and ITC data are widely used to validate theoretical predictions of thermodynamic parameters, as well as to benchmark the results of novel binding assays. In this paper, we discuss several publications from 2007 reporting ITC results. The focus is on applications in biologically oriented fields. We do not intend a comprehensive coverage of all newly accumulated information. Rather, we emphasize work which has captured our attention with originality and far-reaching analysis, or else has provided ideas for expanding the potential of the method. PMID:18729242

Bjeli?, Sasa; Jelesarov, Ilian

2008-01-01

339

Interaction of phenazinium dyes with double-stranded poly(A): Spectroscopy and isothermal titration calorimetry studies  

NASA Astrophysics Data System (ADS)

A comprehensive study on the binding of phenazinium dyes viz. janus green B, indoine blue, safranine O and phenosafranine with double stranded poly(A) using various spectroscopic and calorimetric techniques is presented. A higher binding of janus green B and indoine blue over safranine O and phenosafranine to poly(A) was observed from all experiments. Intercalative mode of binding of the dyes was inferred from fluorescence polarization anisotropy, iodide quenching and viscosity experiments. Circular dichroism study revealed significant perturbation of the secondary structure of poly(A) on binding of these dyes. Results from isothermal titration calorimetry experiments suggested that the binding was predominantly entropy driven with a minor contribution of enthalpy to the standard molar Gibbs energy. The results presented here may open new opportunities in the application of these dyes as RNA targeted therapeutic agents.

Khan, Asma Yasmeen; Saha, Baishakhi; Kumar, Gopinatha Suresh

2014-10-01

340

Aggregation property of glycyrrhizic acid and its interaction with cyclodextrins analyzed by dynamic light scattering, isothermal titration calorimetry, and NMR.  

PubMed

The structural properties of glycyrrhizic acid, a sweet-tasting constituent of Glycyrrhiza glabra, and its interaction with cyclodextrins were analyzed using dynamic light scattering, isothermal titration calorimetry, and NMR. The dynamic light scattering and NMR studies showed that glycyrrhizic acid forms a water-soluble aggregate that disperses upon the addition of ?-cyclodextrin. The high sweetness of glycyrrhizic acid can be closely correlated with this aggregation, because the multimers of glycyrrhizic acid can simultaneously bind to the sweet taste receptors on the human tongue. The isothermal titration calorimetry experiments demonstrated that ?-cyclodextrin binds to glycyrrhizic acid more strongly than ?-cyclodextrin, however, both reactions are accompanied by a favorable change in binding entropy. Considering the large negative change in heat capacity that is observed during the binding of ?-cyclodextrin, the main driving force for the binding is hydrophobic interactions with dehydration, which is typical for inclusion complex. NMR experiments showed that ?-cyclodextrin interacts with the central part of the aglycone moiety, not the glucuronic acid moieties, resulting in high binding affinity. It should also be noted that the two distinct complexes of glycyrrhizic acid with ?-cyclodextrin would exist in aqueous solution. PMID:24844630

Izutani, Yusuke; Kanaori, Kenji; Oda, Masayuki

2014-06-17

341

Journal of Thermal Analysis and Calorimetry, 2003, 72(3), 1127-34, doi:10.1023/A:1025036214044  

E-print Network

Journal of Thermal Analysis and Calorimetry, 2003, 72(3), 1127-34, doi:10.1023/A:1025036214044 1 in "Journal of Thermal Analysis and Calorimetry 72, 3 (2003) 1127-1134" DOI : 10.1023/A:1025036214044 #12;Journal of Thermal Analysis and Calorimetry, 2003, 72(3), 1127-34, doi:10.1023/A:1025036214044 carbonated

Paris-Sud XI, Université de

342

Annual meeting of the Calorimetry Exchange Program: minutes--April 24-25, 1991  

SciTech Connect

On April 24-25, 1991, people from seven DOE organizations participated in the annual meeting of the Calorimetry Exchange Program. The meeting featured a review of the statistical analysis of the calorimetry and gamma-ray data submitted to the exchange program during 1990. The meeting also enabled the group to review progress of five projects concerning a tritium exchange program, reprogramming of the database, a catalogue of measurement techniques, additional samples, and recharacterization of the current sample. There were presentations on recent advances in calorimetry and gamma-ray measurements.

NONE

1991-12-31

343

Isothermic vs thermoneutral hemodiafiltration evaluation by indirect calorimetry.  

PubMed

HD and HDF as hemodialytic therapies normally alter patient's haemodynamic stability, due to the inflammatory response to extracorporeal blood circuit, producing increment of the core temperature (+1.0 degrees C). However, such increase in temperature could be controlled by lowering dialysate's temperature using two main modalities techniques (isothermic and thermoneural) with different patient's thermal balance consequences, not yet well studied. In this work, energy expenditure (EE) was measured by indirect calorimetry in a group of 12 patients waiting kidney transplant. In each patient, EE was assessed (as a power generation) during isothermic and thermoneutral modalities as a manner of cross and prospective study (a) at before therapy, (b) during therapy and (c) at the end of the HDF therapy. Wheraeas, power extraction was measured by a BTM (Blood Temperature Monitor from Fresenius Inc) in order to determine power balance in a thermodynamic model of the extracorporeal circuit. The results showed significant differences in the power balance when EE at during therapy was subtracted from the EE at before therapy. Then, EE increments were 32 Kcal/4-hours during isothermic and 3.6 Kcal/4-hours during thermoneutral HDF sessions (p<0.05). While, BTM totals power extraction was 91 and 16.1 Kcal/4-hours (p<0.05), respectively. Additionally, it was estimated a 12% of EE/day increment during HDF-isothermic at during therapy stage compared with none significative EE increment during thermoneutral modality. The statistical evidence confirmed the expected hypothesis that both modalities affect in different manner the patient's EE. Also, we conclude there is no satisfactory data interpretation when the thermodynamic model was applied expecting null balance between EE increment and BTM power extraction. Therefore, these findings force to think there is need of different BTM design and measurement setting with ability to follow dynamic patient's EE changes with the purpose to achieve a better power balance. PMID:19162756

Cadena, Miguel; Medel, Humberto; Rodrguez, Fausto; Flores, Pedro; Mariscal, Alfonso; Franco, Martha; Pérez-Grovas, Héctor; Escalante, Boris

2008-01-01

344

The Interaction between PEO-PPO-PEO Triblock Copolymers and Ionic Surfactants in Aqueous Solution Studied Using Light Scattering and Calorimetry  

E-print Network

Studied Using Light Scattering and Calorimetry Jo1rgen Jansson,,$ Karin Schille´n,*, Gerd Olofsson scattering, high sensitivity differential scanning, and isothermal titration calorimetry. The studied

Loh, Watson

345

Thermooxidative stability of poppy seeds studied by non-isothermal DSC measurements.  

PubMed

Papaver somniferum L. is an important crop cultivated mostly for seed production. Poppy seeds have a high nutritive value and are used as a food and as a source of edible oil. This oil is a rich source of polyunsaturated fatty acids. It is well known that the unsaturated fatty acids easily undergo oxidation reactions, which lead to the reduction of shelf life, nutritional quality, development of unpleasant tastes and odors. The goal of this study was to develop the methodology for testing the stability of poppy seeds using non-isothermal DSC. For the treatment of the experimental data a method based on non-Arrhenian temperature function has been applied and the values the kinetic parameters have been obtained. In order to assess the durability of the commercial poppy seeds, the lengths of induction periods have been calculated. PMID:24360453

Cibulková, Zuzana; ?ertík, Milan; Dubaj, Tibor

2014-05-01

346

The impact of schizophrenia on frontal perfusion parameters: a DSC-MRI study.  

PubMed

We performed a dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) analysis to study the role of the demographic/clinical information on perfusion parameters between patients with schizophrenia and normal control subjects. 39 schizophrenia patients and 27 normal controls were studied with a Siemens 1.5T magnet. PWI images were obtained following intravenous injection of paramagnetic contrast agent (gadolinium-DTPA). For each perfusion parameter, i.e. relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), mean transit time (MTT) and time-to-peak (TTP), the best predictor model was computed in left and right frontal cortex following a stepwise strategy. First of all, a linear model, including all the sociodemographic information and clinical variables as predictors was computed. At each step, the least significant predictor was excluded and a new linear model was evaluated until all predictors were excluded. Then, the best predictor model was selected based on the F statistic value and on the p value. The models for the rCBF and the rCBV both in the left and right frontal cortex were estimated independently from each other, and the best models contained the same predictors, i.e. clinical state, age, and length of illness. No significant models were obtained for the MTT and the TTP. This study showed a decrease in rCBF and rCBV frontal cortex values in subject affected by schizophrenia. Future DSC-MRI studies should further investigate the role of cerebral perfusion for the pathophysiology of the disease by recruiting first-episode patients and by considering cerebellar, parietal and temporal regions. PMID:21203783

Peruzzo, Denis; Rambaldelli, Gianluca; Bertoldo, Alessandra; Bellani, Marcella; Cerini, Roberto; Silvia, Marini; Pozzi Mucelli, Roberto; Tansella, Michele; Brambilla, Paolo

2011-04-01

347

An Integrated-Circuit Temperature Sensor for Calorimetry and Differential Temperature Measurement.  

ERIC Educational Resources Information Center

Describes the application of an integrated-circuit (IC) chip which provides an easy-to-use, inexpensive, rugged, computer-interfaceable temperature sensor for calorimetry and differential temperature measurement. Discusses its design and advantages. (JRH)

Muyskens, Mark A.

1997-01-01

348

An isoperibol calorimeter for the investigation of biochemical kinetics and isothermal titration calorimetry  

E-print Network

Isothermal titration calorimetry is a technique used to measure the enthalpy change associated with a molecular binding interaction. From these data, the binding constant for the reaction can be determined. In the scope ...

Amadi, Ovid Charles

2007-01-01

349

Calorimetry in Medical Applications: Single-Photon Emission Computed Tomography and Positron Emission Tomography  

SciTech Connect

Positron emission tomography (PET) and single-photon emission computed tomography (SPECT), two nuclear medicine imaging modalities broadly used in clinics and research, share many common instrumentation, detector, and electronics technology platforms with calorimetry in high-energy physics, astronomy, and other physics sciences. Historically, advances made in calorimetry had played major roles in the development of novel approaches and critical technologies essential to the evolution of PET and SPECT. There have also been examples in which PET/SPECT developments had led to new techniques in calorimetry for other application areas. In recent years, several innovations have propelled advances in both calorimetry in general and PET/SPECT in particular. Examples include time-of-flight (TOF) measurements, silicon photomultipliers (SiPMs), etc.

Chen, C.-T. [Department of Radiology, University of Chicago, Chicago, Illinois 60637 (United States); Committee on Medical Physics, University of Chicago, Chicago, Illinois 60637 (United States)

2006-10-27

350

Determination of Heats of Fusion: Using Differential Scanning Calorimetry for the AP Chemistry Courses.  

ERIC Educational Resources Information Center

Describes an exercise designed to be used in an Advanced Placement (AP) chemistry course to accompany the study of thermodynamics. Uses Differential Scanning Calorimetry in teaching the concepts of thermochemistry and thermodynamics. (JRH)

Temme, Susan M.

1995-01-01

351

Thermal and electrical characterization of a micro-hotplate for calorimetry  

E-print Network

This thesis characterizes a micro-hotplate designed at Draper Laboratory. This hotplate will be integrated into a calorimetry system that measures the heat released or absorbed by a reaction. An analytical thermal model ...

Baliga, Radhika

2004-01-01

352

Calorimetry exchange program amendment to 3rd quarter CY92 report LLNL isotopic data  

SciTech Connect

This report is a series of ammendments to the Calorimetry Exchange Quarterly Data Report for third quarter CY1992. The ammendment is needed due to reporting errors encountered in the Lawrence Livermore National Laboratory isotopic data.

Barnett, T.M.

1996-08-01

353

Development of GEM-Based Digital Hadron Calorimetry Using the SLAC KPiX Chip  

SciTech Connect

The development of Digital Hadron Calorimetry for the SiD detector Concept for the International Linear Collider is described. The jet energy requirements of the ILC physics program are discussed. The concept of GEM-based digital hadron calorimetry is presented, followed by a description of, and results from, prototype detectors. Plans are described for the construction of 1m{sup 2} GEM-DHCAL planes to be tested as part of a future calorimeter stack.

White, A.; /Texas U., Arlington /Washington U., Seattle /Unlisted /SLAC

2012-04-12

354

Methanethiol and carbon disulfide: heats of combustion and formation by rotating-bomb calorimetry  

Microsoft Academic Search

The heats of combustion of methanethiol and carbon disulfide were measured by rotating-bomb calorimetry. For combustion calorimetry of methanethiol, normal boiling point 5.96°, liquid samples were sealed in borosilicate glass ampoules rigid enough to withstand the high vapor pressure at room temperature. Samples of carbon disulfide were sealed in polyester bags. The derived values of ..delta..Hf°\\/sub 298.15\\/ for formation in

W. D. Good; J. L. Lacina; J. P. McCullough

1961-01-01

355

The quantification of small degrees of disorder in lactose using solution calorimetry.  

PubMed

There is a realisation that small quantities of amorphous material can have a significant impact on the properties of crystalline solids. Consequently there is a growing interest in quantifying the amount of amorphous material that is present in "crystalline powders". Success has been reported when using isothermal microcalorimetry and vapour sorption techniques, however, the use of solution calorimetry has largely been ignored. In this study the enthalpies of solution of mixtures of amorphous and crystalline lactose are reported concentrating on the range 0-10% w/w amorphous content. It was found that there was a possible error due to water vapour penetration into the ampoule, resulting in crystallisation of the amorphous content, however this was overcome by double sealing the ampoules with wax. Subsequently there was a good correlation between the enthalpy of solution and the amorphous content, which was not adversely affected by stirring rate used during the experiment. Over the range from 0 to 10% amorphous content, quantification of the amorphous content of an unknown would be good to +/-0.5%. The effects of residual moisture retained within a sample were also investigated. Storage at 33% or 43% RH resulted in a much reduced wetting (exothermic) response compared with that seen for completely dry samples, which in turn led to a higher net enthalpy of solution. PMID:11036230

Hogan, S E; Buckton, G

2000-10-10

356

Thermodynamics of cationic lipid-DNA complex formation as studied by isothermal titration calorimetry.  

PubMed Central

The detailed analysis of the cationic lipid-DNA complex formation by means of isothermal titration calorimetry is presented. Most experiments were done using 1,2-dioleyl-sn-glycero-3-ethylphosphocholine (EDOPC), but basic titrations were also done using DOTAP, DOTAP:DOPC, and DOTAP:DOPE mixtures. Complex formation was endothermic with less than 1 kcal absorbed per mole of lipid or DNA charge. This enthalpy change was attributed to DNA-DNA mutual repulsion within the lamellar complex. The exception was DOTAP:DOPE-containing lipoplex for which the enthalpy of formation was exothermic, presumably because of DOPE amine group protonation. Experimental conditions, namely, direction and titration increment as well as concentration of titrant, which dictate the structure of resulting lipoplex (whether lamellar complex or DNA-coated vesicle), were found to affect the apparent thermodynamics of complex formation. The structure, in turn, influences the biological properties of the lipoplex. If the titration of lipid into DNA was carried out in large increments, the DeltaH was larger than when the injection increments were smaller, a finding that is consistent with increased vesicle disruption under large increments and which is expected theoretically. Cationic lipid-DNA binding was weak in high ionic strength solutions, however, the effective binding constant is within micromolar range because of macromolecular nature of the interaction. PMID:12080142

Pozharski, Edwin; MacDonald, Robert C

2002-01-01

357

VO2 and VCO2 variabilities through indirect calorimetry instrumentation.  

PubMed

The aim of this paper is to understand how to measure the VO2 and VCO2 variabilities in indirect calorimetry (IC) since we believe they can explain the high variation in the resting energy expenditure (REE) estimation. We propose that variabilities should be separately measured from the VO2 and VCO2 averages to understand technological differences among metabolic monitors when they estimate the REE. To prove this hypothesis the mixing chamber (MC) and the breath-by-breath (BbB) techniques measured the VO2 and VCO2 averages and their variabilities. Variances and power spectrum energies in the 0-0.5 Hertz band were measured to establish technique differences in steady and non-steady state. A hybrid calorimeter with both IC techniques studied a population of 15 volunteers that underwent the clino-orthostatic maneuver in order to produce the two physiological stages. The results showed that inter-individual VO2 and VCO2 variabilities measured as variances were negligible using the MC while variabilities measured as spectral energies using the BbB underwent 71 and 56% (p?

Cadena-Méndez, Miguel; Escalante-Ramírez, Boris; Azpiroz-Leehan, Joaquín; Infante-Vázquez, Oscar

2013-01-01

358

Drug-Lipid Interactions in the Model Membrane, Dppc-Water: A DSC and Proton NMR Study  

Microsoft Academic Search

The interactions of the keratolytic drug Salicylic Acid (SA) and the antifungal drugs Methyl Paraben (MPB) and Propyl Paraben (PPB) with the model membrane, DPPC-Water, have been studied using DSC and H NMR. The results show that these drug molecules are situated near the membrane interface with their polar group (s) interacting with the vicinal water, while the aromatic regions

K. Usha Deniz; Lata Panicker; P. S. Parvathanathan; Geeta Datta; S. Vivekanandan; K. V. Ramanathan; C. L. Khetrapal

1996-01-01

359

A Shortened Norwegian Adaptation of the Lie Scale for Children (LSC) and the Defensiveness Scale for Children (DSC)  

ERIC Educational Resources Information Center

Ten items consisting of five DSC items and five LSC items were translated into Norwegian in order (a) to control the verbal anxiety responses from defensive tendencies, (b) to handle the problem of response set (the tendency to answer a questionnaire in a stereotyped way), and (c) to permit research concerning the nature of defensiveness itself.…

Haugen, Richard

1978-01-01

360

An Investigation of Thermal Characteristic of Mechanical Crimp Textured Polyester Yarn by Differential Scanning Calorimeter (DSC)  

NASA Astrophysics Data System (ADS)

Deficiencies related to the lack of bulk in flat continuous filament yarns make them unsuitable for apparel, home textiles as well as other applications such as car seat covering. Hence, texturising is employed to impart lofty and bulky characteristics to them. The two major texturising techniques employed for polyester yarn are false-twist and air-jet texturising. Out of these earlier technique depends on the thermoplasticity of the yarn being textured whereas the later one demands subsequent amount of compressed air to carry out cold fluid texturising. A new concept of mechanical crimp texturising has been designed to overcome these limitations of commercially successful techniques. In this new technique, pre-twisted FDY (Fully Drawn Yarn) flat multifilament yarn has been subjected to the higher false-twisting (depending on yarn fineness) action under the condition of underfeed (depending on ductility of parent yarn). The torque caused due to high level of false-twisting, forces the filaments to follow helical path at a certain angle (depends on magnitude of twist and denier per filament) to the filament yarn longitudinal axis. Internal stresses arising in single filaments tend to bend the filament and take the shape of spatial helical spring. After the yarn has passed through the false twisting unit, the initial twist would reassert itself and lock the already formed crimpy convolutions in position. Mechanical crimp textured polyester yarns with different pre-twist and false-twist levels have been subjected to thermal stress analysis using differential Scanning Calorimeter (DSC) in heat-cool-heat mode. The samples were heated at a rate of 10°C/minute. Almost all samples appear to be crystalline in nature. However, the melting endotherm does not show sharp peak. Instead, the diffuse nature of the peak is a signature of a partial crystalline nature (48%) of the samples. After melting the specimens, cooling of the same leads to crystallization of the material. This is exhibited by the exotherm. Heating the so-cooled samples, in general, increases their melting point in almost all samples. Thus melting event is shifted towards higher temperature, except for one sample in which pre-twist level is appreciably high. Thus, DSC is a very useful technique to select and optimize the pre-twist level and may provide quite a significant insight into the thermal stability of the mechanical crimp textured yarn.

Bhattacharya, Someshwar S.; Shaikh, Tasnim N.; Pratap, Arun

2010-06-01

361

Diffusion of liquid polystyrene into glassy poly(phenylene oxide) characterized by DSC  

NASA Astrophysics Data System (ADS)

We report a diffusion study on the polystyrene/poly(phenylene oxide) (PS/PPO) mixture consisted by the PS and PPO nanoparticles. Diffusion of liquid PS into glassy PPO (l-PS/g-PPO) is promoted by annealing the PS/PPO mixture at several temperatures below Tg of the PPO. By tracing the Tgs of the PS-rich domain behind the diffusion front using DSC, we get the relationships of PS weight fractions and diffusion front advances with the elapsed diffusion times at different diffusion temperatures using the Gordon-Taylor equation and core-shell model. We find that the plots of weight fraction of PS vs. elapsed diffusion times at different temperatures can be converted to a master curve by Time-Temperature superposition, and the shift factors obey the Arrhenius equation. Besides, the diffusion front advances of l-PS into g-PPO show an excellent agreement with the t1/2 scaling law at the beginning of the diffusion process, and the diffusion coefficients of different diffusion temperatures also obey the Arrhenius equation. We believe the diffusion mechanism for l-PS/g-PPO should be the Fickean law rather than the Case II, though there are departures of original linearity at longer diffusion times due to the limited liquid supply system.

Li, Linling; Wang, Xiaoliang; Zhou, Dongshan; Xue, Gi

2013-03-01

362

Determination of heat transfer coefficients at the polymer-mold-interface for injection molding simulation by means of calorimetry  

NASA Astrophysics Data System (ADS)

Appropriate modeling of heat transfer from the polymer material to the injection mold is essential to achieve accurate simulation results. The heat transfer is commonly modeled using convective heat transfer and applying heat transfer coefficients (HTC) to the polymer-mold-interface. The set HTC has an influence on the results for filling pressure, cooling performance and shrinkage, among others. The current paper, presents a new strategy to measure HTC in injection molding experiments using Newtons law of cooling. The heat flux is calculated out of demolding heat (measured by means of calorimetry), injection heat (measured by means of an IR-sensor), cooling time and part mass. Cavity surface area, average mold surface temperature and average part surface temperature lead to the HTC.

Stricker, M.; Steinbichler, G.

2014-05-01

363

Transfer kinetics from colloidal drug carriers and liposomes to biomembrane models: DSC studies  

PubMed Central

The release of bioactive molecules by different delivery systems has been studied. We have proposed a protocol that takes into account a system that is able to carry out the uptake of a bioactive molecule released during the time, resembling an in vivo-like system, and for this reason we have used biomembrane models represented by multi-lamellar and unilamellar vesicles. The bioactive molecule loaded delivery system has been put in contact with the biomembrane model and the release has been evaluated, to consider the effect of the bioactive molecule on the biomembrane model thermotropic behavior, and to compare the results with those obtained when a pure drug interacts with the biomembrane model. The differential scanning calorimetry technique has been employed. Depending on the delivery system used, our research permits to evaluate the effect of different parameters on the bioactive molecule release, such as pH, drug loading degree, delivery system swelling, crosslinking agent, degree of cross-linking, and delivery system side chains. PMID:21430957

Sarpietro, Maria Grazia; Castelli, Francesco

2011-01-01

364

Interaction of choline salts with artificial biological membranes: DSC studies elucidating cellular interactions.  

PubMed

To better understand the relationship between the relative cytotoxicity of diluted ionic liquids and their specific interaction with biological membranes, the thermotropic behavior of model lipid membrane systems formulated in a series of choline based organic salts was investigated. Unilamellar vesicles prepared from dipalmitoylphosphatidylcholine were exposed to a series of choline phosphate salts at a concentration of 10mM at pH7.40, and the gel to liquid-crystalline state transition was examined using differential scanning calorimetry. The choline salts that were observed to have a low relative toxicity in previous studies induced minimal changes in the lipid phase transition behavior of these model membranes. In contrast, the salts choline bis(2,4,4-trimethylpentyl)phosphinate and choline bis(2-ethylhexyl)phosphate, both of which were observed to have high relative toxicity, caused distinct disruptions in the lipid phase transition behavior, consistent with penetration of the salts into the acyl chains of the phospholipids. choline bis(2,4,4-trimethylpentyl)phosphinate reduced the Tm and enthalpy of the main transition of dipalmitoylphosphatidylcholine while choline bis(2-ethylhexyl)phosphate induced the equilibration of alternate phases. PMID:23541906

Weaver, Katherine D; Van Vorst, Matthew P; Vijayaraghavan, R; Macfarlane, Douglas R; Elliott, Gloria D

2013-08-01

365

Binding affinity of thermoresponsive polyelectrolyte hydrogels for charged amphiphilic ligands. A DSC approach.  

PubMed

Controlled drug binding and release stand among top requirements postulated for targeted drug delivery systems of the new generations. "Smart" polymers and gels are highly suitable for the controlled delivery due to their structural sensitivity to minor environmental variations. The aim of this work was to study thermoresponsive polyanionic and polycationic hydrogels of N-isopropylacrylamide copolymers with acrylic acid and N-aminopropylmethacrylamide in terms of their interaction with two widely used drugs, propranolol and ibuprofen. Binding energetics of these drugs by the gels in swollen and collapsed state was estimated by means of high-sensitivity differential scanning calorimetry. Thermodynamic parameters of the gel collapse (transition temperature, enthalpy, heat capacity increment, and width) were determined as a dependence of the drug concentrations. From these data the excess free energy of collapse was calculated as a function of drug concentration. Deconvolution of this function resulted in the evaluation of binding parameters and contributions from interactions of various types to the free energy of binding. The binding mechanism of both drugs to the swollen and collapsed gels was elucidated. Its main features are the cooperative character of the drug binding by the collapsed gel and the predominant role of the hydrophobicity of drugs in their affinity for the swollen gel. PMID:24655346

Grinberg, Valerij Y; Burova, Tatiana V; Grinberg, Natalia V; Dubovik, Alexander S; Concheiro, Angel; Alvarez-Lorenzo, Carmen

2014-04-15

366

Structural refinement and DSC characterization of PEEK fiber. [Poly(aryletheretherketone)  

SciTech Connect

The crystalline structure of oriented fibers of poly(aryletheretherketone) (PEEK) has been analyzed by x-ray diffraction and refined by the Linked-Atom Least-Squares procedure. The conformation of chains, consisting of a six-aryl ring unit, is approximated by the refinement of a two-aryl ring unit within the orthorhombic unit subcell with dimensions: a = 7.83 +- 0.02 A, b = 5.94 +- 0.01 A, and c = 9.86 +- 0.04 A. Certain constraints imposed by Pbcn space group symmetry are relaxed during refinement. The results of the two-ring refinement indicate that a single torsion angle can be used to describe the conformation of the six-ring unit. The torsion angle corresponds to the average tilt of the phenylene rings out of the (100) face, and the best fit is obtained with an angle of 37/sup 0/. The simulated powder diffraction pattern based on the atomic coordinates of the six-ring unit matches very closely previously reported patterns for a variety of PEEK specimens. The analysis supports, and extends to oriented fibers, the previously reported finding that space group Pbcn is a valid representation for the structure of PEEK. Differential scanning calorimetry established that the PEEK samples were typical PEEK material.

Fratini, A.V.; Cross, E.M.; Whitaker, R.B.

1986-06-03

367

Electrical conductivity, DSC, XRD, and 7Li NMR studies of rotator crystals n-C21H43COOLi x K(1 - x) (0.33 ? x ? 0.50), n-C m H(2 m + 1)COOLi, and n-C m H(2 m + 1)COOK ( m = 13, 15, 17, 19, and 21)  

NASA Astrophysics Data System (ADS)

Differential scanning calorimetry (DSC) thermograms, X-ray diffraction (XRD) analysis, electrical conductivity ( ?), and 7Li NMR spectroscopy characterization of n-C m H(2 m + 1)COOM solids (M = Li, Na, K; m = 13, 15, 17, 19, 21) and mixed crystals n-C21H43COOLi x K(1 - x) (0.25 ? x ? 0.75) was performed as a function of temperature. DSC thermograms of n-C m H(2 m + 1)COOM revealed several solid-solid phase transitions with large entropy changes. Electrical conductivity studies established that n-C m H(2 m + 1)COOLi crystals are poor electrical conductors. In contrast, n-C m H(2 m + 1)COOK salts were found to have ? values of 10 - 7-10 - 8 S·cm - 1. Since the crystal structures and phase-transition temperatures of both n-C m H(2 m + 1)COOLi and n-C m H(2 m + 1)COOK crystals were similar, they were able to form mixed crystals with the structure n-C x H(2 m + 1)COOLi x K(1 - x). DSC thermograms of the mixed crystals showed a small entropy change at the melting point (? S mp < 13 J K - 1 mol - 1), in addition, large ? S values at the solid-solid phase transition temperature. The ? values obtained for mixed crystals were roughly one order of magnitude greater than those determined for n-C21H43COOK crystals. 7Li NMR spectra of the mixed crystals recorded at various temperatures suggested that the self-diffusion of Li + ions was excited in the highest-temperature solid phase. Based on these results, we have classified these mixed crystals as rotator crystals.

Hayasaki, Tomoyuki; Honda, Hisashi; Hirakawa, Satoru

2013-05-01

368

Determination of the Heat of Combustion of Biodiesel Using Bomb Calorimetry: A Multidisciplinary Undergraduate Chemistry Experiment  

ERIC Educational Resources Information Center

Biodiesel was synthesized by transesterification of waste vegetable oil using common glassware and reagents, and characterized by measuring heat of combustion, cloud point, density and measuring the heat of combustion and density together allows the student the energy density of the fuel. Analyzing the biodiesel can serve as a challenging and…

Akers, Stephen M.; Conkle, Jeremy L.; Thomas, Stephanie N.; Rider, Keith B.

2006-01-01

369

Quantifying high-affinity binding of hydrophobic ligands by isothermal titration calorimetry.  

PubMed

A fast and reliable quantification of the binding thermodynamics of hydrophobic high-affinity ligands employing a new calorimetric competition experiment is described. Although isothermal titration calorimetry is the method of choice for a quantitative characterization of intermolecular interactions in solution, a reliable determination of a dissociation constant (K(D)) is typically limited to the range 100 ?M > K(D) > 1 nM. Interactions displaying higher or lower K(D) values can be assessed indirectly, provided that a suitable competing ligand is available whose K(D) falls within the directly accessible affinity window. This established displacement assay, however, requires the high-affinity ligand to be soluble at high concentrations in aqueous buffer and, consequently, poses serious problems in the study of protein binding involving small-molecule ligands dissolved in organic solvents--a familiar case in many drug-discovery projects relying on compound libraries. The calorimetric competition assay introduced here overcomes this limitation, thus allowing for a detailed thermodynamic description of high-affinity receptor-ligand interactions involving poorly water-soluble compounds. Based on a single titration of receptor into a dilute mixture of the two competing ligands, this competition assay provides accurate and precise values for the dissociation constants and binding enthalpies of both high- and moderate-affinity ligands. We discuss the theoretical background underlying the approach, demonstrate its practical application to metal ion chelation and high-affinity protein-inhibitor interactions, and explore its potential and limitations with the aid of simulations and statistical analyses. PMID:23130786

Krainer, Georg; Broecker, Jana; Vargas, Carolyn; Fanghänel, Jörg; Keller, Sandro

2012-12-18

370

Linear isothermal crystal growth rate of i-polypropylene by differential scanning calorimetry  

Microsoft Academic Search

In the present work equations are derived that enable us to calculate the linear crystal growth rate using DSC-isothermal peaks. The primary nuclei density is taken into account by measuring the average spherulite radius of already crystallized samples by means of polarization microscopy. The results, thus obtained, show that the isothermal crystallization process of i-polypropylene proceeds in two stages, the

Atanas Milkov Atanassov

1987-01-01

371

Monitoring of an RNA Multistep Folding Pathway by Isothermal Titration Calorimetry  

PubMed Central

Abstract Isothermal titration calorimetry was used to monitor the energetic landscape of a catalytic RNA, specifically that of the hepatitis delta virus ribozyme. Using mutants that isolated various tertiary interactions, the thermodynamic parameters of several ribozyme-substrate intermediates were determined. The results shed light on the impact of several tertiary interactions on the global structure of the ribozyme. In addition, the data indicate that the formation of the P1.1 pseudoknot is the limiting step of the molecular mechanism. Last, as illustrated here, isothermal titration calorimetry appears to be a method of choice for the elucidation of an RNA's folding pathway. PMID:19134473

Reymond, Cedric; Bisaillon, Martin; Perreault, Jean-Pierre

2009-01-01

372

Historical Roots and Development of Thermal Analysis and Calorimetry  

Microsoft Academic Search

\\u000a Apparently, the first person which used a thought experiment of continuous heating and cooling of an illustrative body was\\u000a curiously the Czech thinker and Bohemian educator [1], latter refugee Johann Amos Comenius (Jan Amos Komenský, 1592–1670) when trying to envisage the properties of substances. In his “Physicae Synopsis”, which he finished in 1629 and published first in Leipzig in 1633,

Jaroslav Šesták; Pavel Hubík; Ji?í J. Mareš

373

Screening a Peptide Library by DSC and SAXD: Comparison with the Biological Function of the Parent Proteins  

PubMed Central

We have recently identified the membranotropic regions of the hepatitis C virus proteins E1, E2, core and p7 proteins by observing the effect of protein-derived peptide libraries on model membrane integrity. We have studied in this work the ability of selected sequences of these proteins to modulate the L?-L? and L?-HII phospholipid phase transitions as well as check the viability of using both DSC and SAXD to screen a protein-derived peptide library. We demonstrate that it is feasible to screen a library of peptides corresponding to one or several proteins by both SAXD and DSC. This methodological combination should allow the identification of essential regions of membrane-interacting proteins which might be implicated in the molecular mechanism of membrane fusion and/or budding. PMID:19194494

Perez-Berna, Ana J.; Pabst, George; Laggner, Peter; Villalain, Jose

2009-01-01

374

Cloning of the cDNA (DSC1) coding for human type 1 desmocollin and its assignment to chromosome 18  

SciTech Connect

Desmosomes are adhesive epithelial junctions that contain two distinct classes of cadherin-related glycoproteins (desmogleins and desmocollins), both of which occur as several different isoforms whose expression is related to epithelial differentiation. The authors have now isolated cDNA clones encoding a human desmocollin that is expressed in the more differentiated layers of human epidermis. The isoform has 53% amino acid identity with the previously isolated human (type 3) desmocollin, which is expressed in the basal layers of the epidermis. However, the N- and C-termini of the mature proteins are more highly conserved. Using a panel of somatic cell hybrids, human type 1 desmocollin (gene DSC1) has been assigned to chromosome 18, the same location as the other desmocollin gene (DSC3) and the three desmoglein (DSG) genes already mapped. 49 refs., 5 figs., 1 tab.

King, I.A.; Buxton, R.S. (National Institute for Medical Research, London (United Kingdom)); Spurr, N.K.; Arnemann, J. (Clare Hall Labs., Hertfordshire (United Kingdom))

1993-11-01

375

Age dependency of the regional cerebral blood volume (rCBV) measured with dynamic susceptibility contrast MR imaging (DSC)  

Microsoft Academic Search

The changes of the regional cerebral blood volume (rCBV) with age were studied using dynamic susceptibility contrast MRI (DSC). We examined an unselected, random sample of 71 consecutive patients referred for work-up of suspected intracranial tumors (35 normal examinations, 36 tumors) with a standard 1.5 T clinical MR system. Determination of the rCBV was performed with a T2?-weighted simultaneous dual

Frederik Wenz; Katrin Rempp; Gunnar Brix; Michael V. Knopp; Friedemann Gückel; Thomas Heß; Gerhard van Kaick

1996-01-01

376

Student Learning of Thermochemical Concepts in the Context of Solution Calorimetry.  

ERIC Educational Resources Information Center

Analyzes student performance on solution calorimetry problems in an introductory university chemistry class. Includes data from written classroom exams for 207 students and an extensive longitudinal interview with a student. Indicates learning difficulties, most of which appear to originate from failure to understand, that net increases and…

Greenbowe, Thomas J.; Meltzer, David E.

2003-01-01

377

Direct absorbed dose to water determination based on water calorimetry in scanning proton beam delivery  

SciTech Connect

Purpose: The aim of this manuscript is to describe the direct measurement of absolute absorbed dose to water in a scanned proton radiotherapy beam using a water calorimeter primary standard. Methods: The McGill water calorimeter, which has been validated in photon and electron beams as well as in HDR {sup 192}Ir brachytherapy, was used to measure the absorbed dose to water in double scattering and scanning proton irradiations. The measurements were made at the Massachusetts General Hospital proton radiotherapy facility. The correction factors in water calorimetry were numerically calculated and various parameters affecting their magnitude and uncertainty were studied. The absorbed dose to water was compared to that obtained using an Exradin T1 Chamber based on the IAEA TRS-398 protocol. Results: The overall 1-sigma uncertainty on absorbed dose to water amounts to 0.4% and 0.6% in scattered and scanned proton water calorimetry, respectively. This compares to an overall uncertainty of 1.9% for currently accepted IAEA TRS-398 reference absorbed dose measurement protocol. The absorbed dose from water calorimetry agrees with the results from TRS-398 well to within 1-sigma uncertainty. Conclusions: This work demonstrates that a primary absorbed dose standard based on water calorimetry is feasible in scattered and scanned proton beams.

Sarfehnia, A.; Clasie, B.; Chung, E.; Lu, H. M.; Flanz, J.; Cascio, E.; Engelsman, M.; Paganetti, H.; Seuntjens, J. [Medical Physics Unit, McGill University, Montreal, Quebec, H3G-1A4 (Canada); Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Medical Physics Unit, McGill University, Montreal, Quebec, H3G-1A4 (Canada); Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Medical Physics Unit, McGill University, Montreal, Quebec, H3G-1A4 (Canada)

2010-07-15

378

Accelerating rate calorimetry: A new technique for safety studies in lithium systems  

NASA Technical Reports Server (NTRS)

The role of exothermic reactions in battery test modes is discussed. The exothermic reactions are characterized with respect to their time-temperature and time-pressure behavior. Reactions occuring for any major exotherm were examined. The accelerating rate calorimetry methods was developed to study lithium cells susceptibility to thermal runaway reactions following certain abuse modes such as forced discharge into reversal and charging.

Ebner, W. B.

1982-01-01

379

Levitation calorimetry. IV - The thermodynamic properties of liquid cobalt and palladium.  

NASA Technical Reports Server (NTRS)

Some of the thermodynamic properties of liquid cobalt and palladium investigated by means of levitation calorimetry are reported and discussed. The presented data include the specific heats and heats of fusion of the liquid metals, and the emissivities of the liquid metal surfaces.

Treverton, J. A.; Margrave, J. L.

1971-01-01

380

Protein Unfolding Coupled to Ligand Binding: Differential Scanning Calorimetry Simulation Approach  

ERIC Educational Resources Information Center

A comprehensive theoretical description of thermal protein unfolding coupled to ligand binding is presented. The thermodynamic concepts are independent of the method used to monitor protein unfolding but a differential scanning calorimetry is being used as a tool for examining the unfolding process.

Celej, Maria Soledad; Fidelio, Gerardo Daniel; Dassie, Sergio Alberto

2005-01-01

381

Simulating SiD Calorimetry: Software Calibration Procedures and Jet Energy Resolution  

E-print Network

Simulated calorimeter performance in the SiD detector is examined. The software calibration procedures are described, as well as the perfect pattern recognition PFA reconstruction. Performance of the SiD calorimeters is summarized with jet energy resolutions from calorimetry only, perfect pattern recognition and the SiD PFA algorithm. Presented at LCWS08[1].

Ron Cassell

2009-02-16

382

Event by event pile-up compensation in digital timestamped calorimetry  

Microsoft Academic Search

In digital nuclear calorimetry, the effect on measured pulse amplitudes by piling up of pulses can be compensated based on the pulses’ respective timestamps, making use of the fact that, for stable pulse shapes, the amount of pile-up induced error at each pulse amplitude measurement is completely determined by the amplitudes and precise occurrences in time of the neighboring pulses.

M. Vencelj; K. Bucar; R. Novak; H. J. Wörtche

2009-01-01

383

Student learning of thermochemical concepts in the context of solution calorimetry  

Microsoft Academic Search

Student understanding of heat and thermal phenomena has been the subject of considerable investigation in the science education literature. Published studies have reported student conceptions on a variety of advanced topics, but calorimetry - one of the more elementary applications of thermochemical concepts - has apparently received little attention from science education researchers. Here we report a detailed analysis of

Thomas J. Greenbowe; David E. Meltzer

2003-01-01

384

Determination of calorific values of forest waste biomass by static bomb calorimetry  

Microsoft Academic Search

Calorific values of forest waste originating from forestry works such as woodland cleaning, reaforestation and, all other silviculture tasks, were measured by static bomb calorimetry. These waste materials, heretofore considered as useless refuse, are beginning to be used as alternative fuels in wide social sectors all over the world. Two of the main forest species, eucalyptus (E. globulus Labill) and

Lisardo Núñez-Regueira; Jose A. Rodr??guez-Añon; Jorge Proup??n-Castiñeiras; A. Vilanova-Diz; N. Montero-Santoveña

2001-01-01

385

Energetic study of residual forest biomass using calorimetry and thermal analysis  

Microsoft Academic Search

Summary The European policy on energy focus on the search for alternative and renewable sources of energy where forest biomass plays a significant role. In this article, calorific values of different kinds of forest residues (leaves, thin branches, barks, etc.) are reported. These values were measured by combustion bomb calorimetry with the objective of understanding, through different risk indices, the

L. Núñez-Regueira; J. A. Rodríguez-Añón; J. Proupín; B. Mouriño; R. Artiaga-Diaz

2005-01-01

386

Relationship Between Flame Length and Fireline Intensity Obtained by Calorimetry at Laboratory Scale  

Microsoft Academic Search

The difficulties in measuring Byram's fireline intensity have led many researchers to derive an empirical relation between the fireline intensity and flame length, which is easier to measure at the practical (firefighting) level. In this article, we address both the estimation of Byram's fireline intensity by comparison with oxygen consumption calorimetry (OC) measurement and the test of formulations for fireline

Toussaint Barboni; Frédéric Morandini; Lucile Rossi; Thierry Molinier; Paul-Antoine Santoni

2012-01-01

387

Mathematical analysis for radiometric calorimetry of a radiating sphere  

NASA Technical Reports Server (NTRS)

Equations are derived from which the temperature dependence of both the specific heat and the thermal diffusivity of a spherical sample of material can be calculated from observations of the time dependence of the surface temperature and the time-rate of energy loss from the sample as it cools. The derivation takes into account the nonuniformity of the interior temperature field of the sample, and the resulting equations can be applied not only to radiative cooling, but also to any other cooling mechanism that does not violate the assumed spherical symmetry. The analysis excludes change of phase, but it does take thermal expansion into account. To permit the making of estimates necessary for the design of radiative cooling experiments, a universal temperature-time cooling curve is derived for the post-transient cooling regime of a radiating sphere of any size with arbitrary, but constant, thermal parameters.

Schmid, L. A.

1982-01-01

388

Calorimetry: Introduction, Overview and physics requirement at HL-LHC  

E-print Network

We discuss how the HL-LHC luminosity target and Phase II physics goals drive the Calorimeter performance requirements of the LHC experiments, and motivate the program of Upgrades being developed to address these. Radiation damage to detector and electronics components will impose challenges to the operation of the existing calorimeter systems and will limit their lifetime. Instantaneous luminosities above the nominal LHC values may induce significant degradation in the response of some detectors (in particular in the forward region). To optimize the performance of the systems and cope with the physics goals in Phase-II the trigger system will set new requirements for the calorimeter readout.

Mannelli, M; The ATLAS collaboration

2013-01-01

389

Synthesis and Thermal Behavior of Silica?Graft?Polypropylene Nanocomposites Studied by Step?Scan DSC and TGA  

Microsoft Academic Search

Silica graft poly(propylene) (silica?g?PP) nanocomposites were successfully prepared by radical grafting copolymerization and ring?opening reaction. Their thermal properties were studied by step?scan differential scanning calorimetry (SDSC) and thermogravimetric analysis (TGA). The exothermic peaks in the IsoK baseline (Cp,IsoK, nonreversing signal) of SDSC reveal that PP and silica?g?PP nanocomposites undergo melting?recrystallization?remelting during heating. The peak temperatures of recrystallization and remelting shift

Kang Zheng; XiaYin Yao; XingYou Tian; Lin Chen; Hao He; Yong Li

2006-01-01

390

Experimental measurements of the heats of formation of Fe{sub 3}Pt, FePt, and FePt{sub 3} using differential scanning calorimetry  

SciTech Connect

Using differential scanning calorimetry (DSC), the heats of formation of Fe{sub 3}Pt, FePt, and FePt{sub 3} were determined from the reaction of sputter deposited Fe/Pt multilayer thin-films with a periodicity of 200 nm but different overall compositions. Film compositions were measured by energy dispersive x-ray spectrometry. The phases present along the reaction path were identified by x-ray diffraction. For the most Fe-rich phase, namely, Fe{sub 3}Pt, the measured enthalpy of formation was -9.3 {+-} 1.3 kJ/mol in a film with a composition of 70.4:29.6 ({+-}0.2 at. %) Fe:Pt. For FePt, the measured enthalpy of formation was -27.2 {+-} 2.2 kJ/g-atom in a 49.0:51.0 ({+-}0.5 at. %) Fe:Pt film. For FePt{sub 3}, which is the most Pt rich intermetallic phase, the measured enthalpy of formation was -23.7 {+-} 2.2 in a film with a composition of 22.2:77.8 ({+-}0.6 at. %) Fe:Pt. The reaction enthalpies for films with Fe:Pt compositions of 44.5:55.5 ({+-}0.3 at. %) and 38.5:61.5 ({+-}0.4 at. %) were -26.9 {+-} 1.0 and -26.6 {+-} 0.6 kJ/g-atom, respectively, which taken together with the value for the 49.0:51.0 film demonstrate the relative insensitivity of the reaction enthalpy to film composition over a broad composition range in the vicinity of the equiatomic composition. The experimental heats of formation are compared with two sets of reported first-principles calculated values for each of the three phases at exact stoichiometry.

Wang, B.; Berry, D. C.; Chiari, Y.; Barmak, K. [Department of Materials Science and Engineering and the Data Storage Systems Center, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States)

2011-07-01

391

Structure and Phase Transitions of Poly (Hexamethylene p,p'-Bibenzoate) as Studied by DSC and Real-Time SAXS/WAXS Employing Synchrotron Radiation  

SciTech Connect

Real-time small and wide angle X-ray scattering as well as DSC studies were carried out in order to analyzes the structure and phase transitions of liquid crystalline thermotropic poly(methylene p,p' bibenzoat)

Katerska, B.; Krasteva, M. [University of Sofia, Faculty of Physics, blvd James Bourchier 5, 1164 Sofia (Bulgaria); Perez, E. [Instituto de Sciencia y Technolodia de Polimeros (CSIC) Juan de la Ciera 3, 28006 Madrid (Spain)

2007-04-23

392

Analysis of Siderite Thermal Decomposition by Differential Scanning Calorimetry  

NASA Technical Reports Server (NTRS)

Characterization of carbonate devolitilization has important implications for atmospheric interactions and climatic effects related to large meteorite impacts in platform sediments. On a smaller scale, meteorites contain carbonates which have witnessed shock metamorphic events and may record pressure/temperature histories of impact(s). ALH84001 meteorite contains zoned Ca-Mg-Fe-carbonates which formed on Mars. Magnetite crystals are found in the rims and cores of these carbonates and some are associated with void spaces leading to the suggestion by Brearley et al. that the crystals were produced by thermal decomposition of the carbonate at high temperature, possibly by incipient shock melting or devolitilization. Golden et al. recently synthesized spherical Mg-Fe-Ca-carbonates from solution under mild hydrothermal conditions that have similar carbonate compositional zoning to those of ALH84001. They have shown experimental evidence that the carbonate-sulfide-magnetite assemblage in ALH84001 can result from a multistep inorganic process involving heating possibly due to shock events. Experimental shock studies on calcium carbonate prove its stability to approx. 60 GPa, well in excess of the approx. 45 GPa peak pressures indicated by other shock features in ALH84001. In addition, Raman spectroscopy of carbonate globules in ALH84001 indicates no presence of CaO and MgO. Such oxide phases should be found associated with the magnetites in voids if these magnetites are high temperature shock products, the voids resulting from devolitilization of CO2 from calcium or magnesium carbonate. However, if the starting material was siderite (FeCO3), thermal breakdown of the ALH84001 carbonate at 470 C would produce iron oxide + CO2. As no documentation of shock effects in siderite exists, we have begun shock experiments to determine whether or not magnetite is produced by the decomposition of siderite within the < 45GPa pressure window and by the resultant thermal pulse to approx. 600 C experienced by ALH84001. Here, we report thermal and compositional characterization of unshocked siderite and its transition to magnetite. Additional information is contained in the original extended abstract.

Bell, M. S.; Lin, I.-C.; McKay, D. S.

2000-01-01

393

Study of polymorphic transformation of ornidazole drug by differential scanning calorimetry and other complementary techniques.  

PubMed

Differential scanning calorimetric (DSC) curves recorded for ornidazole drug during heating and cooling showed that the drug which melted around 86.1 degrees C undercooled to well below ambient room temperature of 27 degrees C during the cooling cycle. The undercooled melt kept in the freezer at 0 degree C for 10 days duration also remained in the viscous liquid form. This liquid on taking out from the freezer after ten days and ageing at ambient room temperature of 27 degrees C for 12 h transformed into white powder. The DSC pattern recorded for this white powder consisted of two prominent endothermic peaks beginning at 73.2 and 85.9 degrees C, respectively, suggesting that the powder consisted of a mixture of more than one phase. The X-ray diffraction (XRD) pattern recorded for this powder showed it to be a mixture of semi-crystalline phase and the original compound. The semi-crystalline phase melted at 73.2 degrees C prior to the melting of original compound at 85.9 degrees C. This phase on further ageing for 7 days transforms almost completely to its original form. DSC observations were corroborated by XRD and scanning electron microscopy (SEM) techniques. PMID:19051580

Desai, Satish R; Dharwadkar, Sanjiv R

2008-01-01

394

Temperature dependence of adsorption of PEGylated lysozyme and pure polyethylene glycol on a hydrophobic resin: comparison of isothermal titration calorimetry and van't Hoff data.  

PubMed

The influence of temperature on the adsorption of PEGylated lysozyme and pure PEG on Toyopearl PPG-600M, a hydrophobic resin, is studied by batch equilibrium measurements and pulse response experiments. Differently PEGylated lysozymes are used for the studies, enabling a systematic variation of the solute properties. Either ammonium sulfate or sodium chloride are added. The enthalpy of adsorption is calculated from a van't Hoff analysis based on these data. It is also directly measured by Isothermal Titration Calorimetry. In the investigated temperature range from 5 °C to 35 °C adsorption is favored by higher temperatures and hence endothermic. The results of the van't Hoff analysis of the equilibrium and the pulse response data agree well. Discrepancies between enthalpies of adsorption obtained by calorimetry and van't Hoff analysis are found and discussed. We conclude that the most likely explanation is that thermodynamic equilibrium is not reached in the experiments even though they were carried out carefully and in the generally accepted way. PMID:25016322

Werner, Albert; Hackemann, Eva; Hasse, Hans

2014-08-22

395

Student learning of thermochemical concepts in the context of solution calorimetry  

NSDL National Science Digital Library

Student understanding of heat and thermal phenomena has been the subject of considerable investigation in the science education literature. Published studies have reported student conceptions on a variety of advanced topics, but calorimetry - one of the more elementary applications of thermochemical concepts - has apparently received little attention from science education researchers. Here we report a detailed analysis of student performance on solution calorimetry problems in an introductory university chemistry class. We include data both from written classroom exams for 207 students, and from an extensive longitudinal interview series with a single subject who was herself part of that larger class. Our findings reveal a number of learning difficulties, most of which appear to originate from failure to understand that net increases and decreases in bond energies during aqueous chemical reactions result in energy transfers out of and into, respectively, the total mass of the resultant solution.

Greenbowe, Thomas

2005-10-06

396

Thermal characterization of starch-water system by photopyroelectric technique and adiabatic scanning calorimetry  

NASA Astrophysics Data System (ADS)

Starch is one of the most important carbohydrate sources in human nutrition. For the thermal analysis of starch, techniques such as differential scanning calorimetry have been extensively used. As an alternative, we have applied a photopyroelectric (PPE) configuration and adiabatic scanning calorimetry (ASC) to study the thermal properties of starch-water systems. For this study we used nixtamalized corn flour and potato starch with different quantities of distilled water, in order to obtain samples with different moisture content. By using PPE and ASC methods we have measured, for each technique separately, the heat capacity by unit volume (?cp) at room temperature for a corn flour sample at 90% moisture. The obtained values agree within experimental uncertainty. By using these techniques we also studied the thermal behavior of potato starch, at 80% moisture, in the temperature range where phase transitions occur. In this case the PPE signal phase could be used as a sensitive and versatile monitor for phase transitions.

Cruz-Orea, A.; Bentefour, E. H.; Jamée, P.; Chirtoc, M.; Glorieux, C.; Pitsi, G.; Thoen, J.

2003-01-01

397

Tritium Accounting Stability of a ZrCo Bed with 'In-Bed' Gas Flowing Calorimetry  

Microsoft Academic Search

Zirconium-Cobalt (ZrCo) tritium storage bed with 'in-bed' gas flowing calorimetry has been developed as a self-assaying system for the Tritium Storage and Delivery System of ITER. The basic tritium accounting characteristics have been investigated and practical data on the accounting stability has been accumulated under gram level tritium storage for more than 8 years. The initial sensitivity of tritium was

Takumi Hayashi; Takumi Suzuki; Masayuki Yamada; Masataka Nishi

2005-01-01

398

Differential scanning calorimetry investigations on Eu-doped fluorozirconate-based glass ceramics  

PubMed Central

The properties of Eu-doped fluorochlorozirconate (FCZ) glass ceramics upon thermal processing and the influence of Eu-doping on the formation of BaCl2 nanocrystals therein have been investigated. Differential scanning calorimetry indicates that higher Eu-doping shifts the crystallization peak of the nanocrystals in the glass to lower temperatures, while the glass transition temperature remains constant. The activation energy and the thermal stability parameters for the BaCl2 crystallization are determined. PMID:21286235

Paßlick, C.; Ahrens, B.; Henke, B.; Johnson, J. A.; Schweizer, S.

2010-01-01

399

A new approach for non-contact calorimetry: system identification using pseudo-white noise perturbation  

Microsoft Academic Search

This paper presents a new technique for non-contact calorimetry measurement of specific heat capacity and thermal conductivity.\\u000a Based on pseudo-white noise modulation and system identification, commonly used in electronics and communication engineering,\\u000a this procedure can be used to measure the transfer function of the sample temperature variation due to heating power variation.\\u000a The heat capacity and internal heat transfer coefficient

Pascal Schetelat; Jacqueline Etay

2011-01-01

400

Estimating relative physical workload using heart rate monitoring: a validation by whole-body indirect calorimetry  

Microsoft Academic Search

Measuring physical workload in occupational medicine is fundamental for risk prevention. An indirect measurement of total and relative energy expenditure (EE) from heart rate (HR) is widely used but it has never been validated. The aim of this study was to validate this HR-estimated energy expenditure (HREEE) method against whole-body indirect calorimetry. Twenty-four-hour HR and EE values were recorded continuously

Martin Garet; Gil Boudet; Christophe Montaurier; Michel Vermorel; Jean Coudert; Alain Chamoux

2005-01-01

401

Graphite calorimetry for absorbed dose measurements in heavy-ion beams  

NASA Astrophysics Data System (ADS)

In order to sophisticate the radiotherapy high accuracy knowledge of the absorbed dose delivered to the patient is essential The main methods of absolute dosimetry are indicated as follows a Dosimetry by ion chamber b Fricke dosimetry and c Calorimetry The calorimetry is most direct method of dosimetry due to direct measurement of energy deposit in principle and no requirement of information of radiation fields for the calibration Many countries tend to adopt the calorimetry to determine the standard absorbed dose to water and become to be capable of deciding the absorbed dose in precision of about 0 6 for photon and electron beams Despite the recent progress of particle therapy the parameters such as w-value and stopping power ratio for ionization chambers in the particles is not obtained accurately Therefore that causes uncertainty in determination of the absolute dose For this reason we developed a graphite calorimeter to obtain high precision absorbed dose and reduce the uncertainty for various beams When the absorbed dose of 1 Gy is irradiated to the sensitive volume the temperature rise is about 1 4 milliKelvins The performance require the resolution of plus or minus 7 micro Kelvins to measure it in precision of plus or minus 0 5 The stability within several micro Kelvins per minute is necessary to obtain measurable background The miniature glass bead thermistors were embedded in the sensitive volume to perform active control of temperature The resistance change of these thermistors is approximately 0 68 Ohms and 488 micro Ohms at

Sakama, M.; Kanai, T.; Fukumura, A.

402

Thermal Analysis of Plastics  

ERIC Educational Resources Information Center

This lab experiment illustrates the use of differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) in the measurement of polymer properties. A total of seven exercises are described. These are dry exercises: students interpret previously recorded scans. They do not perform the experiments. DSC was used to determine the…

D'Amico, Teresa; Donahue, Craig J.; Rais, Elizabeth A.

2008-01-01

403

Characterization of compression-molded UHMWPE, PMMA and PMMA/MMA treated UHMWPE: density measurement, FTIR-ATR, and DSC.  

PubMed

Considered one of the weak links in the total hip replacement (THR), efforts to enhance the interfacial strength between bone cement and ultra-high molecular weight polyethylene (UHMWPE) acetabular cup had been conducted in this laboratory. Following the successful demonstration of high interfacial strengths for our new acetabular component design, the nature of physical, chemical, and thermal property of the compression-molded specimens, including UHMWPE, PMMA/MMA treated UHMWPE, and PMMA has been investigated in this study. Density results from a density gradient column showed that the molding processes and conditions were adequate for complete sintering of UHMWPE and PMMA powders. FTIR-ATR results gave a direct evidence that PMMA did exist in the PMMA/MMA treated UHMWPE matrix. It also revealed a clear diffusion-related behavior across the interface. Under the high temperature and pressure, the UHMWPE powders undergo drastic changes of their morphology and crystalline structures. These changes were examined by differential scanning calorimeter (DSC) which showed a large difference in terms of % crystallinity. The percent of PMMA deposited in the treated UHMWPE was 17.8%, 18.8%, and 24.3% from the analyses of density, FTIR-ATR, and DSC, respectively. Finally, an evidence of diffusive behavior at the interface exhibited diffusion of PMMA occurring across the interfaces between the treated UHMWPE and UHMWPE or PMMA. PMID:11790863

Park, K D; Khang, G S; Lee, H B; Park, J B

2001-01-01

404

Morphology development upon melting of ultrahigh molecular weight polyethylene formed at high pressure by Ultra SAXS and DSC  

NASA Astrophysics Data System (ADS)

The morphology development on the melting of ultrahigh molecular weight polyethylenes (UHMWPE), formed from melt crystallization at high different pressures, was studied by ultra small-angle X-ray scattering (USAXS)and DSC. The heating rate used was 5C/min. At 41M psi, UHMWPEs show dominant chain-extended lamellae (CEL) at Mw 4MM, 5MM and 6MM. At 30M psi, UHMWPEs show dominant chain-folding lamellae (CFL) at Mw 4MM, 5MM and 6MM. At 35M psi, UHMWPEs show both CEL and CFL at Mw 5MM and 6MM and a dominant CFL at Mw 4MM. With dominant CFL, USAXS shows a measurable long spacing, which increases with temperature. With dominant CEL, USAXS shows an immeasurable long spacing and relatively strong ultra-small angle scattering intensity. The integrated scattering intensity shows an exponential increase with temperature. The thickest CEL and CFL melt at the end of the DSC endotherm, where the USAXS (corrected for melt scattering) shows a diffuse profile only. This CEL or CFL thickness was estimated using an approach based on the single lamella structure factor. The results show a largest thickness about 100nm for CEL and about 50nm for CFL. Acknowledgement: This work was supported by a NSF grant (DMR 9732653).

Wang, Zhigang; Wang, Xuehui; Stribeck, Norbert; Hsiao, Benjamin S.; Han, Charles C.

2001-03-01

405

Gravitational Calorimetry  

E-print Network

I generalize the quasilocal formulation of thermodynamics of Brown and York to include dilaton theories of gravity as well as Abelian and Yang-Mills gauge matter fields with possible dilaton couplings. The resulting formulation is applicable to a large class of theories including two-dimensional toy models and the low energy limit of string theory as well as to many types of matter such as massless scalar fields, electromagnetism, Yang-Mills fields, and matter induced cosmological constants. I use this formalism to evaluate the thermodynamic variables for several black hole spacetimes. I find that the formulation can handle black hole spacetimes that are not asymptotically flat as well as rotating black hole spacetimes, and black hole spacetimes possessing a dilaton field, an electric charge, and a magnetic charge.

Jolien D. E. Creighton

1996-10-17

406

HEAT OF HYDRATION OF SALTSTONE MIXES-MEASUREMENT BY ISOTHERMAL CALORIMETRY  

SciTech Connect

This report provides initial results on the measurement of heat of hydration of Saltstone mixes using isothermal calorimetry. The results were obtained using a recently purchased TAM Air Model 3116 Isothermal Conduction Calorimeter. Heat of hydration is an important property of Saltstone mixes. Greater amounts of heat will increase the temperature of the curing mix in the vaults and limit the processing rate. The heat of hydration also reflects the extent of the hydraulic reactions that turn the fluid mixture into a ''stone like'' solid and consequently impacts performance properties such as permeability. Determining which factors control these reactions, as monitored by the heat of hydration, is an important goal of the variability study. Experiments with mixes of portland cement in water demonstrated that the heats measured by this technique over a seven day period match very well with the literature values of (1) seven day heats of hydration using the standard test method for heat of hydration of hydraulic cement, ASTM C 186-05 and (2) heats of hydration measured using isothermal calorimetry. The heats of hydration of portland cement or blast furnace slag in a Modular Caustic Side Solvent Extraction Unit (MCU) simulant revealed that if the cure temperature is maintained at 25 C, the amount of heat released over a seven day period is roughly 62% less than the heat released by portland cement in water. Furthermore, both the blast furnace slag and the portland cement were found to be equivalent in heat production over the seven day period in MCU. This equivalency is due to the activation of the slag by the greater than 1 Molar free hydroxide ion concentration in the simulant. Results using premix (a blend of 10% cement, 45% blast furnace slag, and 45% fly ash) in MCU, Deliquification, Dissolution and Adjustment (DDA) and Salt Waste Processing Facility (SWPF) simulants reveal that the fly ash had not significantly reacted (undergone hydration reactions) after seven days (most likely less than 5%). There were clear differences in the amount of heat released and the peak times of heat release for the three different simulants. It turns out that SWPF simulant mixes give off greater heat than does MCU and DDA simulant mixes. The temperature dependence of the heat of hydration was measured by carrying out these measurements at 25, 40 and 55 C. In general, the peak times shifted to shorter times as the isothermal temperature increased and the amount of heat released was independent of temperature for DDA and MCU but slightly higher at higher temperatures for SWPF. The goal of this study is to apply this technique to the measurement of the heat of hydration of mixes that will be made as part of the variability study. It is important to understand which variables will impact (and to what extent) the amount of heat generated and the peak times for the heat release. Those variables that can be controlled can then be tuned to adjust the heat of hydration as long as the other properties are still acceptable. The first application of heat of hydration measurements to the variability study was completed and the results presented in this report. These measurements were made using Phase VI mixes (SWPF simulants) following a statistical design that included variation in the compositional and operational variables. Variation in both the amount of heat released and the peak times for the heat release were observed. The measured ranges were 23 Joules per gram of premix for the heat release and 23 hours for the peak time of heat release at 25 C. Linear models with high R{sup 2} values and no statistical evidence for lack of fit were developed that relate the amount of heat release and the peak time for heat release for the Phase VI mixes to certain variables. The amount of heat released was a function of the aluminate and portland cement concentrations as well as the temperature of mixing. The peak time for heat release was a function of aluminate, portland cement and total nitrate plus nitrite concentrations. A comparison was made of the mea

Harbour, J; Vickie Williams, V; Tommy Edwards, T

2007-07-02

407

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

408

Regional and voxel-wise comparisons of blood flow measurements between dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) and arterial spin labeling (ASL) in brain tumors.  

PubMed

The objective of the current study was to evaluate the regional and voxel-wise correlation between dynamic susceptibility contrast (DSC) and arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) measurement of cerebral blood flow (CBF) in patients with brain tumors. Thirty patients with histologically verified brain tumors were evaluated in the current study. DSC-MRI was performed by first using a preload dose of gadolinium contrast, then collecting a dynamic image acquisition during a bolus of contrast, followed by posthoc contrast agent leakage correction. Pseudocontinuous ASL was collected using 30 pairs of tag and control acquisition using a 3-dimensional gradient-echo spin-echo (GRASE) acquisition. All images were registered to a high-resolution anatomical atlas. Average CBF measurements within regions of contrast-enhancement and T2 hyperintensity were evaluated between the two modalities. Additionally, voxel-wise correlation between CBF measurements obtained with DSC and ASL were assessed. Results demonstrated a positive linear correlation between DSC and ASL measurements of CBF when regional average values were compared; however, a statistically significant voxel-wise correlation was only observed in around 30-40% of patients. These results suggest DSC and ASL may provide regionally similar, but spatially different measurements of CBF. PMID:22672084

White, Carissa M; Pope, Whitney B; Zaw, Taryar; Qiao, Joe; Naeini, Kourosh M; Lai, Albert; Nghiemphu, Phioanh L; Wang, J J; Cloughesy, Timothy F; Ellingson, Benjamin M

2014-01-01

409

Azide derivatized anticancer agents of Vitamin K 3: X-ray structural, DSC, resonance spectral and API studies  

NASA Astrophysics Data System (ADS)

Compound 1 [1-imino (acetyl hydrazino)-Vitamin K 3], displays valence tautomerically related electronic isomers as Form I and Form II. Form I exhibits 2D packing fragment with 1D ribbon chains of N-H⋯O hydrogen bonds and shows EPR silent features. While Form II is EPR active and exhibits biradical nature with double quantum transitions at g = 2.0040. 1H NMR of compound 2, [1-imino (hydrazino carboxylate)-Vitamin K 3] and Form II exhibit ? delocalization via resonance assisted H-bonding [RAHB] effect compared to Form I. Molecular interactions in Form I and II are visualized by DSC. The electronic structures of compounds 1 and 2 have been correlated to their API values by measuring anticancer activities, mitochondrial potentials and DNA shearing patterns. Form II and compound 2 indicate mitochondria mediated apoptosis (˜75% cell death) while Form I causes 35% cell death.

Badave, Kirti; Patil, Yogesh; Gonnade, Rajesh; Srinivas, Darbha; Dasgupta, Rajan; Khan, Ayesha; Rane, Sandhya

2011-12-01

410

Kinetics of thermolysis of lanthanum nitrate with hexamethylenetetramine: Crystal structure, TG-DSC, impact and friction sensitivity studies, Part-96  

NASA Astrophysics Data System (ADS)

The development of high energetic materials includes process ability and the ability to attain insensitive munitions (IM). This paper investigates the preparation of lanthanum metal nitrate complex of hexamethylenetetramine in water at room temperature. This complex of molecular formulae [La (NO3)2(H2O)6] (2HMTA) (NO3-) (H2O) was characterized by X-ray crystallography. Thermal decomposition was investigated using TG, TG-DSC and ignition delay measurements. Kinetic analysis of isothermal TG data has been investigated using model fitting methods as well as model free isoconversional methods. The sensitivity measurements towards mechanical destructive stimuli such as impact and friction were carried out and the complex was found to be insensitive. In order to identify the end product of thermolysis, X-ray diffraction patterns of end product was carried out which proves the formation of La2O3.

Nibha; Baranwal, B. P.; Singh, Gurdip; Singh, C. P.; Daniliuc, Constantin G.; Soni, P. K.; Nath, Yogeshwar

2014-11-01

411

A DSC study on crystalline LaRC TPI powder - A new version with higher initial molecular weight  

NASA Technical Reports Server (NTRS)

A new version of crystalline Langley Research Center Thermoplastic Polyimide (LaRC-TPI) imidized powder, which possesses a higher initial molecular weight (MW), has been prepared and characterized. The scheme used for cyclodehydration during the synthesis of this material is described. Evidence of a higher initial MW for the subject LaRC-TPI is supported by both measurements of the inherent viscosity and the DSC thermograms. An initial melting peak at 295 C is noted in the freshly-synthesized sample. The powder can be recrystallized at any elevated temperatures below 340 C, and a single crystalline endothemic peak is always observed after various thermal histories. The heat of fusion for the fresh sample, as represented by the area under the melting peak in the directional scanning calorimeter thermogram, is about 3.9 cal/gm. Comparisons of thermal properties for the subject material are made to those exhibited by the commercial LaRC-TPI powder.

Hou, Tan-Hung; Bai, Jia-Mo; St. Clair, Terry L.

1987-01-01

412

Calorimetry Exchange Program Quarterly Data Report, 4th Quarter CY91  

SciTech Connect

The goals of the Calorimetry Sample Exchange Program are: (1) Discuss measurement differences, (2) Review and improve analytical measurements and methods, (3) Discuss new measurement capabilities, (4) Provide data to DOE on measurement capabilities to evaluate shipper-receiver differences, (5) Provide characterized or standard materials as necessary for exchange participants, (6) Provide a measurement control program for plutonium analysis. A sample of PuO{sub 2} powder is available at each participating site for NDA measurement, including either or both calorimetry and high-resolution gamma-ray spectroscopy, the elements which are typically combined to provide a calorimetric assay of plutonium. The facilities measure the sample as frequently and to the level of precision which they desire, and then submit the data to the Exchange for analysis. Statistical tests are used to evaluate the data and to determine if there are significant differences from accepted values for the exchange sample or from data previously reported by that facility. This information is presented, in the form of a quarterly report, intended for use by Exchange participants in measurement control programs, or to indicate when bias corrections may be appropriate. No attempt, however, has been made to standardize methods or frequency of data collection, calibration, or operating procedures. Direct comparisons between laboratories may, therefore, be misleading since data have not been collected to the same precision or for the same time periods. A meeting of the participants of the Calorimetry Exchange is held annually at EG&G Mound Applied Technologies. The purposes of this meeting are to discuss measurement differences, problems, and new measurement capabilities, and to determine the additional activities needed to fulfill the goals of the Exchange.

McClelland, T.M.

1996-07-01

413

Melting, Recrystallization and Superheating of Polymer Crystals Studied by Fast Calorimetry (1 MK/s)  

NASA Astrophysics Data System (ADS)

For polymers the origin of the multiple melting peaks observed in DSC curves is still controversially discussed. This is due to the difficulty to investigate the melting of the originally formed crystals exclusively. Recrystallization is a fast process and most experimental techniques applied so far do not allow fast heating in order to prevent recrystallization totally. We developed a thin-film (chip) calorimeter allowing scanning rates as high as one million Kelvin per second. The calorimeter was used to study the melting of isothermally crystallized polymers like isotactic polystyrene (iPS), isotactic polypropylene (iPP), poly(ethylene therephthalate) (PET) and others. Our results on melting at rates as high as 1,000,000 K/s support the validity of a melting-recrystallization-remelting process at low scanning rates (DSC) for all studied polymers. At isothermal conditions they form crystals, which all melt within a few dozens of K slightly above the isothermal crystallization temperature. There is no evidence for the formation of different populations of crystals with significantly different stability (melting temperatures) under isothermal conditions.

Schick, Christoph; Minakov, Alexander; Wurm, Andreas; Zhuravlev, Evgeny

2009-03-01

414

High Sensitivity Differential Scanning Calorimetry Study of DNA-Cationic Liposome Complexes  

Microsoft Academic Search

Purpose  To investigate plasmid DNA interactions with liposomes prepared from dimyristoylglyceroethylphosphocholine (EDMPC) and DOPE\\u000a using high sensitivity differential scanning calorimetry (HSDSC).\\u000a \\u000a \\u000a \\u000a Materials and Methods  Large unilamellar liposomes of EDMPC with DOPE (mol ratio 0–50%) were prepared. Plasmid DNA was added to give a final DNA\\/lipid\\u000a (?\\/+) charge ratio of 0.5. Samples were placed into an HSDSC and cooled to 3°C, held isothermally

Mark Saunders; Kevin M. G. Taylor; Duncan Q. M. Craig; Karen Palin; Hazel Robson

2007-01-01

415

Energy storage capacity of reversible liquid phase Diels-Alder reactions as determined by drop calorimetry  

SciTech Connect

Several Diels-Alder reactions were evaluated as possible candidates for energy storage. The goal was to use simple drop calorimetry to screen reactions and to identify those with high energy storage capacities. The dienes used were furan and substituted furans. The dienophiles used were maleic anhydride and substituted maleic anhydrides. Sixteen reactions have been examined. Three had energy storage capacities that were increased due to reaction (maleic anhydride and 2-methyl furan, maleic anhydride and 2-ethyl furan, maleic anhydride and 2,5-dimethyl furan). The remaining thirteen showed no increase in apparent heat capacity due to reaction.

Chung, C.P.

1983-01-01

416

New challenges for pharmaceutical formulations and drug delivery systems characterization using isothermal titration calorimetry.  

PubMed

Long viewed as the 'method of choice' for characterizing thermodynamics and stoichiometry of molecular interactions, with high sensitivity, isothermal titration calorimetry (ITC) has been applied to many areas of pharmaceutical analysis. This review highlights ITC employment to measure binding thermodynamics and their use for pharmaceutical formulations and drug delivery system characterization particularly cyclodextrin-guest interactions, investigation of micellar-based systems, polyelectrolytes, nucleic acid interactions with multivalent cations and the optimization of DNA targeting and delivery. Furthermore, the potential of ITC for the characterization of different functionalities carried by nanoparticles as well as their interaction with living systems was outlined. PMID:18617012

Bouchemal, Kawthar

2008-11-01

417

Psychometric evaluation of the Korean version of the Diabetes Symptom Checklist-Revised (DSC-R) for Patients with Type 2 Diabetes  

PubMed Central

Background This study was to elucidate the psychometric properties of the Korean version of the Diabetes Symptom Checklist-Revised (K-DSC-R), which is a patient-reported outcome measure of diabetes symptom burden. Methods A sample of 432 Korean patients with diabetes was recruited from university hospitals. The data were analyzed using exploratory factor analysis (EFA), confirmatory factor analysis (CFA), multitrait/multi-item correlation, Pearson’s correlation, t-test, ANOVA, and Cronbach’s alpha for construct, item-convergent/discriminant, concurrent, and known-groups validity, and internal consistency reliability. Results EFA extracted a total of 29 items clustered into 7 subscales from the K-DSC-R. The construct of the seven-subscales was supported by CFA. The scaling success rates of item-convergent validity were 100% for all subscales, and those of item-discriminant validity ranged from 83.3% to 100%. Patients in more-depressed groups and in the HbA1c-uncontrolled group had higher K-DSC-R scores, satisfying the known-groups validity. The subscales of the K-DSC-R were moderately correlated with health-related quality of life, indicative of the established concurrent validity. The Cronbach’s alpha of the K-DSC-R was 0.92. Conclusions The psychometric properties of the K-DSC-R have been established. It is thus appropriate for use with respect to reliability and validity in practice and clinical trials for Korean patients with type 2 diabetes. PMID:24885358

2014-01-01

418

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

419

Interfacial Water at Protein Surfaces: Wide-Line NMR and DSC Characterization of Hydration in Ubiquitin Solutions  

PubMed Central

Wide-line 1H-NMR and differential scanning calorimetry measurements were done in aqueous solutions and on lyophilized samples of human ubiquitin between ?70°C and +45°C. The measured properties (size, thermal evolution, and wide-line NMR spectra) of the protein-water interfacial region are substantially different in the double-distilled and buffered-water solutions of ubiquitin. The characteristic transition in water mobility is identified as the melting of the nonfreezing/hydrate water. The amount of water in the low-temperature mobile fraction is 0.4 g/g protein for the pure water solution. The amount of mobile water is higher and its temperature dependence more pronounced for the buffered solution. The specific heat of the nonfreezing/hydrate water was evaluated using combined differential scanning calorimetry and NMR data. Considering the interfacial region as an independent phase, the values obtained are 5.0–5.8 J·g?1·K?1, and the magnitudes are higher than that of pure/bulk water (4.2 J·g?1·K?1). This unexpected discrepancy can only be resolved in principle by assuming that hydrate water is in tight H-bond coupling with the protein matrix. The specific heat for the system composed of the protein molecule and its hydration water is 2.3 J·g?1·K?1. It could be concluded that the protein ubiquitin and its hydrate layer behave as a highly interconnected single phase in a thermodynamic sense. PMID:19348762

Tompa, Kalman; Banki, Peter; Bokor, Monika; Kamasa, Pawel; Lasanda, Gyorgy; Tompa, Peter

2009-01-01

420

Direct calorimetry of free-moving eels with manipulated thyroid status  

NASA Astrophysics Data System (ADS)

In birds and mammals, the thyroid gland secretes the iodothyronine hormones of which tetraiodothyronine (T4) is less active than triiodothyronine (T3). The action of T3 and T4 is calorigenic and is involved in the control of metabolic rate. Across all vertebrates, thyroid hormones also play a major role in differentiation, development and growth. Although the fish thyroidal system has been researched extensively, its role in thermogenesis is unclear. In this study, we measured overall heat production to an accuracy of 0.1 mW by direct calorimetry in a free-moving European eel ( Anguilla anguilla L.) with different thyroid status. Hyperthyroidism was induced by injection of T3 and T4, and hypothyroidism was induced with phenylthiourea. The results show for the first time at the organismal level, using direct calorimetry, that neither overall heat production nor overall oxygen consumption in eels is affected by hyperthyroidism. Therefore, we conclude that the thermogenic metabolism-stimulating effect of thyroid hormones (TH) is not present with a cold-blooded fish species like the European eel. This supports the concept that TH does not stimulate thermogenesis in poikilothermic species.

van Ginneken, Vincent; Ballieux, Bart; Antonissen, Erik; van der Linden, Rob; Gluvers, Ab; van den Thillart, Guido

2007-02-01

421

Technical memo on PbF/sub 2/ as a Cherenkov radiator for EM calorimetry  

SciTech Connect

It is apparent that the ever increasing rates and radiation levels found in high-energy physics are excluding more and more instrumental techniques. Those techniques that are remaining are often pushed to their theoretical limits. This situation reaches an extreme at the proposed luminosity of the SSC. Also, it is fair to say that at the SSC, after the accelerator itself, calorimetry will be the next most important physics tool. Therefore, we should be ever alert to new calorimetry techniques which may operate in this demanding environment. The material lead fluoride, PbF/sub 2/, has a real potential of yielding a very compact, high-resolution electromagnetic calorimeter that is both fast and radiation hard. PbF/sub 2/ is not a scintillator but a Cherenkov radiator like lead glass, but with a radiation length even harder shorter than of BGO. This memo discusses this property as well as comparison PbF/sub 2/ to other scintillating materials. 2 refs., 14 figs., 1 tab.

Anderson, D.F.

1989-06-26

422

Analog VS Digital Hadron Calorimetry at a Future Electron-Positron Linear Collider  

NASA Astrophysics Data System (ADS)

Precision jet measurements at a future e+e- linear collider may only be possible using so-called Particle Flow Algorithms (PFAs). While there are many possible implementations of P-flow techniques, they all have in common separation of induced calorimeter showers from charged and neutral hadrons (as well as photons) within a jet. Shower reconstruction in the calorimeter becomes more important than energy measurement of hadrons. The calorimeter cells must be highly granular both transverse to the particle trajectory and in longitudinal segmentation. It is probable that as the cell size decreases, it will be harder to get an energy measure from each cell (analog calorimetry). Using only the hit information (digital calorimetry) may be the best way to measure the neutral hadron energy contribution to jets. In this paper, comparisons of analog and digital methods of measuring the contributions of neutral hadrons to jets are made in simulation and in the context of a particular PFA, indicating that the digital method is at least equal to the analog case in jet energy resolution.

Magill, Stephen R.

2005-02-01

423

Reference dosimetry for light-ion beams based on graphite calorimetry.  

PubMed

Developments in hadron therapy require efforts to improve the accuracy of the dose delivered to a target volume. Here, the determination of the absorbed dose under reference conditions was analysed. Based on the International Atomic Energy Agency TRS-398 code of practice, for hadron beams, the combined standard uncertainty on absorbed dose to water under reference conditions, derived from ionisation chambers, is too large. This uncertainty is dominated by the beam quality correction factors, [Formula: see text], mainly due to the mean energy to produce one ion pair in air, wair. A method to reduce this uncertainty is to carry out primary dosimetry, using calorimetry. A [Formula: see text]-value can be derived from a direct comparison between calorimetry and ionometry. Here, this comparison is performed using a graphite calorimeter in an 80-MeV A(-1) carbon ion beam. Assuming recommended TRS-398 values of water-to-graphite stopping power ratio and the perturbation factor for an ionisation chamber, preliminary results indicate a wair-value of 35.5 ± 0.9 J C(-1). PMID:24336190

Rossomme, S; Palmans, H; Thomas, R; Lee, N; Duane, S; Bailey, M; Shipley, D; Bertrand, D; Romano, F; Cirrone, P; Cuttone, G; Vynckier, S

2014-10-01

424

Calorimetry, activity, and micro-FTIR analysis of CO chemisorption, titration, and oxidation on supported Pt  

NASA Technical Reports Server (NTRS)

The value of in situ analysis on CO chemisorption, titration and oxidation over supported Pt catalysts using calorimetry, catalytic and micro-FTIR methods is illustrated using silica- and titania-supported samples. Isothermal CO-O and O2-CO titrations have not been widely used on metal surfaces and may be complicated if some oxide supports are reduced by CO titrant. However, they can illuminate the kinetics of CO oxidation on metal/oxide catalysts since during such titrations all O and CO coverages are scanned as a function of time. There are clear advantages in following the rates of the catalyzed CO oxidation via calorimetry and gc-ms simultaneously. At lower temperatures the evidence they provide is complementary. CO oxidation and its catalysis of CO oxidation have been extensively studied with hysteresis and oscillations apparent, and the present results suggest the benefits of a combined approach. Silica support porosity may be important in defining activity-temperature hysteresis. FTIR microspectroscopy reveals the chemical heterogeneity of the catalytic surfaces used; it is interesting that the evidence with regard to the dominant CO surface species and their reactivities with regard to surface oxygen for present oxide-supported Pt are different from those seen on graphite-supported Pt.

Sermon, Paul A.; Self, Valerie A.; Vong, Mariana S. W.; Wurie, Alpha T.

1990-01-01

425

Thermodynamic characterization of the multivalent binding of chartreusin to DNA  

Microsoft Academic Search

Characterization of the thermodynamics of DNA- drug interactions is a very useful part in rational drug design. Isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC) and UV melt- ing experiments have been used to analyze the multivalent (intercalation plus minor groove) bind- ing of the antitumor antibiotic chartreusin to DNA. Using DNA UV melting studies in the presence of the

Francisca Barcelo; Damiana Capoand JosePortugal

2002-01-01

426

Copyright 2002 by the Genetics Society of America The DSC1 Channel, Encoded by the smi60E Locus, Contributes to Odor-Guided  

E-print Network

olfactory behavior. One of these smell-impaired (smi) mutants, smi60E, contains a P[lArB] transposon map the smell- impaired phenotype to the P[lArB] insertion site. Wild-type behavior is restored upon P-element excision. Evidence that reduction in DSC1 rather than in L41 expression is responsible for the smell

Mackay, Trudy F.C.

427

Feasibility study on using fast calorimetry technique to measure a mass attribute as part of a treaty verification regime  

SciTech Connect

The attribute measurement technique provides a method for determining whether or not an item containing special nuclear material (SNM) possesses attributes that fall within an agreed upon range of values. One potential attribute is whether the mass of an SNM item is larger than some threshold value that has been negotiated as part of a nonproliferation treaty. While the historical focus on measuring mass attributes has been on using neutron measurements, calorimetry measurements may be a viable alternative for measuring mass attributes for plutonium-bearing items. Traditionally, calorimetry measurements have provided a highly precise and accurate determination of the thermal power that is being generated by an item. In order to achieve this high level of precision and accuracy, the item must reach thermal equilibrium inside the calorimeter prior to determining the thermal power of the item. Because the approach to thermal equilibrium is exponential in nature, a large portion of the time spent approaching equilibrium is spent with the measurement being within {approx}10% of its final equilibrium value inside the calorimeter. Since a mass attribute measurement only needs to positively determine if the mass of a given SNM item is greater than a threshold value, performing a short calorimetry measurement to determine how the system is approaching thermal equilibrium may provide sufficient information to determine if an item has a larger mass than the agreed upon threshold. In previous research into a fast calorimetry attribute technique, a two-dimensional heat flow model of a calorimeter was used to investigate the possibility of determining a mass attribute for plutonium-bearing items using this technique. While the results of this study looked favorable for developing a fast calorimetry attribute technique, additional work was needed to determine the accuracy of the model used to make the calculations. In this paper, the results from the current work investigating the fast calorimetry attribute technique will be presented.

Hauck, Danielle K [Los Alamos National Laboratory; Bracken, David S [Los Alamos National Laboratory; Mac Arthur, Duncan W [Los Alamos National Laboratory; Santi, Peter A [Los Alamos National Laboratory; Thron, Jonathan [Los Alamos National Laboratory

2010-01-01

428

Determining the thermodynamic melting parameters of sulfamethoxazole, trimethoprim, urea, nicodin, and their double eutectics by differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

The literature data on the thermodynamic melting characteristics of sulfamethoxazole, urea, trimethoprim, and nicodin are analyzed for individual compounds. Their enthalpies and melting points, either individually or in the composition of eutectics, are found by means of DSC. The entropies of fusion and the cryoscopic constants of individual compounds are calculated.

Agafonova, E. V.; Moshchenskii, Yu. V.; Tkachenko, M. L.

2013-08-01

429

Comparison of first pass bolus AIFs extracted from sequential 18F-FDG PET and DSC-MRI of mice  

NASA Astrophysics Data System (ADS)

Accurate kinetic modelling of in vivo physiological function using positron emission tomography (PET) requires determination of the tracer time-activity curve in plasma, known as the arterial input function (AIF). The AIF is usually determined by invasive blood sampling methods, which are prohibitive in murine studies due to low total blood volumes. Extracting AIFs from PET images is also challenging due to large partial volume effects (PVE). We hypothesise that in combined PET with magnetic resonance imaging (PET/MR), a co-injected bolus of MR contrast agent and PET ligand can be tracked using fast MR acquisitions. This protocol would allow extraction of a MR AIF from MR contrast agent concentration-time curves, at higher spatial and temporal resolution than an image-derived PET AIF. A conversion factor could then be applied to the MR AIF for use in PET kinetic analysis. This work has compared AIFs obtained from sequential DSC-MRI and PET with separate injections of gadolinium contrast agent and 18F-FDG respectively to ascertain the technique?s validity. An automated voxel selection algorithm was employed to improve MR AIF reproducibility. We found that MR and PET AIFs displayed similar character in the first pass, confirmed by gamma variate fits (p<0.02). MR AIFs displayed reduced PVE compared to PET AIFs, indicating their potential use in PET/MR studies.

Evans, Eleanor; Sawiak, Stephen J.; Ward, Alexander O.; Buonincontri, Guido; Hawkes, Robert C.; Adrian Carpenter, T.

2014-01-01

430

Effect of chirality on PVP/drug interaction within binary physical mixtures of ibuprofen, ketoprofen, and naproxen: a DSC study.  

PubMed

We report on the thermal behavior of freshly prepared binary drug/polymer physical mixtures that contained ibuprofen, ketoprofen, or naproxen as a drug, and polyvinylpyrrolidone (PVP), hydroxyethylcellulose (HEC), or methylcellulose (MC) as excipient. At 6-10 degrees C/min heating rates the DSC detected a sharp, single endotherm that corresponds to the melting of drug. On heating physical mixtures of PVP and racemic ibuprofen or ketoprofen at lower heating rates, another endotherm was registered in front of the original one. To observe the additional endotherm, specific minimal values of the heating rate and of PVP weight fraction were needed; for ibuprofen and ketoprofen they were 1.5 and 2.0 degrees C/min, and 5 and 15% (w/w), respectively. At greater PVP weight fractions the top temperatures, T(mp), of both peaks were reduced almost linearly indicating strong solid-state interfacial reaction between the drug particles and PVP matrix. The additional endotherm was abolished at greater heating rates (2 degrees C/min for ibuprofen, 3 degrees C/min for ketoprofen), by replacing the racemate with respective S+-enantiomer and by replacing PVP with HEC and MC. Hence, the possible inclusion of enantioselective component within the PVP/drug interaction, responsible for the amorphization of physical mixture over storage, is assumed. PMID:18988257

Ivanov, Ivan T; Tsokeva, Zhivka

2009-08-01

431

THE HYDROLYSIS AND OXIDATION BEHAVIOR OF LITHIUM BOROHYDRIDE AND MAGNESIUM HYDRIDE DETERMINED BY CALORIMETRY  

SciTech Connect

Lithium borohydride, magnesium hydride and the 2:1 'destabilized' ball milled mixtures (2LiBH{sub 4}:MgH{sub 2}) underwent liquid phase hydrolysis, gas phase hydrolysis and air oxidation reactions monitored by isothermal calorimetry. The experimentally determined heats of reaction and resulting products were compared with those theoretically predicted using thermodynamic databases. Results showed a discrepancy between the predicted and observed hydrolysis and oxidation products due to both kinetic limitations and to the significant amorphous character of observed reaction products. Gas phase and liquid phase hydrolysis were the dominant reactions in 2LiBH{sub 4}:MgH{sub 2} with approximately the same total energy release and reaction products; liquid phase hydrolysis displayed the maximum heat flow for likely environmental exposure with a peak energy release of 6 (mW/mg).

Brinkman, K; Donald Anton, D; Joshua Gray, J; Bruce Hardy, B

2008-03-13

432

Thermophysical analysis of II-VI semiconductors by PPE calorimetry and lock-in thermography  

SciTech Connect

An accurate determination of thermophysical properties such as thermal diffusivity, thermal effusivity and thermal conductivity is extremely important for characterization and quality assurance of semiconductors. Thermal diffusivity and effusivity of some binary semiconductors have been investigated. Two experimental techniques were used: a contact technique (PPE calorimetry) and a non contact technique (lock-in thermography). When working with PPE, in the back (BPPE) configuration and in the thermally thick regim of the pyroelectric sensor, we can get the thermal diffusivity of the sample by performing a scanning of the excitation frequency of radiation. Thermal effusivity is obtained in front configuration (sensor directly irradiated and sample in back position) by performing a thickness scan of a coupling fluid. By using the lock-in thermography technique, the thermal diffusivity of the sample is obtained from the phase image. The results obtained by the two techniques are in good agreement. Nevertheless, for the determination of thermal diffusivity, lock-in thermography is preferred.

Streza, M.; Dadarlat, D. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Strza?kowski, K. [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 (Poland)] [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 (Poland)

2013-11-13

433

Spacecraft calorimetry as a test of the dark matter scattering model for flyby anomalies  

E-print Network

In previous papers we have shown that scattering of spacecraft nucleons from dark matter gravitationally bound to the earth gives a possible explanation of the flyby velocity anomalies. In addition to flyby velocity changes arising from the average over the scattering cross section of the collision-induced nucleon velocity change, there will be spacecraft temperature increases arising from the mean squared fluctuation of the collision-induced velocity change. We give here a quantitative treatment of this effect, and suggest that careful calorimetry on spacecraft traversing the region below 70,000 km where the flyby velocity changes take place could verify, or at a minimum place significant constraints, on the dark matter scattering model.

Stephen L. Adler

2009-10-08

434

The Yang-Yang anomaly in liquid-liquid criticality: Experimental evidence from adiabatic scanning calorimetry  

NASA Astrophysics Data System (ADS)

Using adiabatic scanning calorimetry, we have found the first experimental evidence of the Yang-Yang anomaly in liquid-liquid criticality from high-resolution two-phase isobaric heat capacity measurements for the binary mixture 3-pentanol + nitromethane. The results suggest a rather strong effect. The critical amplitude of the partial molar heat capacity is higher for the component with larger molecular volume, in accordance with the predictions of complete scaling as obtained from the customary observed asymmetric behavior of the coexistence-curve diameter. This consolidates complete scaling as the true formulation of fluid-fluid criticality. The quantitative analysis indicates that molecular size is not the only microscopic factor at play in asymmetric liquid-liquid criticality.

Losada-Pérez, Patricia; Tripathi, Chandra Shekhar Pati; Leys, Jan; Cerdeiriña, Claudio A.; Glorieux, Christ; Thoen, Jan

2012-01-01

435

DNA heats up : Energetics of genome ejection from phage revealed by isothermal titration calorimetry  

E-print Network

Most bacteriophages are known to inject their double-stranded DNA into bacteria upon receptor binding in an essentially spontaneous way. This downhill thermodynamic process from the intact virion toward the empty viral capsid plus released DNA is made possible by the energy stored during active packaging of the genome into the capsid. Only indirect measurements of this energy have been available until now using either single-molecule or osmotic suppression techniques. In this paper, we describe for the first time the use of isothermal titration calorimetry to directly measure the heat released (or equivalently the enthalpy) during DNA ejection from phage lambda, triggered in solution by a solubilized receptor. Quantitative analyses of the results lead to the identification of thermodynamic determinants associated with DNA ejection. The values obtained were found to be consistent with those previously predicted by analytical models and numerical simulations. Moreover, the results confirm the role of DNA hydration in the energetics of genome confinement in viral capsids.

Meerim Jeembaeva; B. Jönsson; Martin Castelnovo; Alex Evilevitch

2010-01-06

436

Thermodynamic and kinetic properties of interpolymer complexes assessed by isothermal titration calorimetry and surface plasmon resonance.  

PubMed

Interpolymer complexes (IPCs) formed between complimentary polymers in solution have shown a wide range of applications from drug delivery to biosensors. This work describes the combined use of isothermal titration calorimetry and surface plasmon resonance to investigate the thermodynamic and kinetic processes during hydrogen-bonded interpolymer complexation. Varied polymers that are commonly used in layer-by-layer coatings and pharmaceutical preparations were selected to span a range of chemical functionalities including some known IPCs previously characterized by other techniques, and other polymer combinations with unknown outcomes. This work is the first to comprehensively detail the thermodynamic and kinetic data of hydrogen bonded IPCs, aiding understanding and detailed characterization of the complexes. The applicability of the two techniques in determining thermodynamic, gravimetric and kinetic properties of IPCs is considered. PMID:25186562

Bizley, Samuel C; Williams, Adrian C; Khutoryanskiy, Vitaliy V

2014-11-01

437

Enthalpy of formation of YB/sub 4/ by high temperature calorimetry  

SciTech Connect

The molar enthalpy of formation of YB/sub 4/, ..delta..H/sup 0//sub f/, has been determined by platinum mixing calorimetry at 1400 K to be -(261.7 +- 8.9) kJ/mol or -(52.3 +- 1.8) kJ/g-atom for 1/5 YB/sub 4/. The latter value is comparable in magnitude to that for 1/7 LaB/sub 6/, (-57.2 +- 1.7) kJ/g-atom; both values are much less exothermic than the corresponding value for 1/3 ScB/sub 2/, which is (-102.3 +- 4.9) kJ/g-atom.

Topor, L.; Kleppa, O.J.

1986-10-01

438

Toward New High Temperature Reference Materials for Calorimetry and Thermal Analysis  

NASA Astrophysics Data System (ADS)

The French National Metrology Laboratory LNE-LCM has developed a high temperature reference facility for accurate measurements of the specific heat capacity and of the enthalpy of fusion of materials over the temperature range [23 °C, 1000 °C]. The metrological approach was to modify a commercial Calvet calorimeter in order to lower the uncertainty of measurement and to insure the metrological traceability of the measurements to the SI units, in particular by designing a new calibration system. The enthalpies of fusion of pure metals (indium, tin and silver) and of a binary alloy Ag-28Cu have been measured. The results obtained on the three pure metallic materials are in very good agreement with data obtained by other National Metrology Institutes (NMIs) using adiabatic calorimetry.

Razouk, R.; Hay, B.; Himbert, M.

2014-08-01

439

Studying submicrosecond protein folding kinetics using a photolabile caging strategy and time-resolved photoacoustic calorimetry.  

PubMed

Kinetic measurement of protein folding is limited by the method used to trigger folding. Traditional methods, such as stopped flow, have a long mixing dead time and cannot be used to monitor fast folding processes. Here, we report a compound, 4-(bromomethyl)-6,7-dimethoxycoumarin, that can be used as a "photolabile cage" to study the early stages of protein folding. The folding process of a protein, RD1, including kinetics, enthalpy, and volume change, was studied by the combined use of a phototriggered caging strategy and time-resolved photoacoustic calorimetry. The cage caused unfolding of the photolabile protein, and then a pulse UV laser (?10(-9) s) was used to break the cage, leaving the protein free to refold and allowing the resolving of two folding events on a nanosecond time scale. This strategy is especially good for monitoring fast folding proteins that cannot be studied by traditional methods. PMID:20737588

Chen, Hsin-Liang; Hsu, Jack C-C; Viet, Man Hoang; Li, Mai Suan; Hu, Chin-Kun; Liu, Chia-Hsun; Luh, Frederick Y; Chen, Silvia S-W; Chang, Evan S-H; Wang, Andrew H-J; Hsu, Min-Feng; Fann, Wunshain; Chen, Rita P-Y

2010-11-01

440

Fast Scanning Calorimetry study of non-equilibrium relaxation in fragile organic liquids  

NASA Astrophysics Data System (ADS)

Fast scanning calorimetry (FSC), capable of heating rates in excess of 1000000 K/s, was combined with vapor deposition technique to investigate non-equilibrium relaxation in micrometer thick viscous liquid films of several organic compounds (e.g.2-ethyl-1-hexanol, Toluene, and 1-propanol) under high vacuum conditions. Rapid heating of samples, vapor deposited at temperatures above their standard glass softening transition (Tg), resulted in observable endotherms which onset temperatures were strongly dependent on heating rate and the deposition temperature. Furthermore, all of the studied compounds were characterized by distinct critical deposition temperatures at which observation of endotherm became impossible. Based on the results of these studies, we have developed a simple model which makes it possible to infer the equilibrium enthalpy relaxation times for liquids from FSC data. We will discuss implications of these studies for contemporary models of non-equilibrium relaxation in glasses and supercooled liquids.

Sadtchenko, Vlad; Bhattacharya, Deepanjan; O'Reilly, Liam

2013-03-01

441

Adsorption calorimetry during metal vapor deposition on single crystal surfaces: Increased flux, reduced optical radiation, and real-time flux and reflectivity measurements  

SciTech Connect

Thin films of metals and other materials are often grown by physical vapor deposition. To understand such processes, it is desirable to measure the adsorption energy of the deposited species as the film grows, especially when grown on single crystal substrates where the structure of the adsorbed species, evolving interface, and thin film are more homogeneous and well-defined in structure. Our group previously described in this journal an adsorption calorimeter capable of such measurements on single-crystal surfaces under the clean conditions of ultrahigh vacuum [J. T. Stuckless, N. A. Frei, and C. T. Campbell, Rev. Sci. Instrum. 69, 2427 (1998)]. Here we describe several improvements to that original design that allow for heat measurements with ?18-fold smaller standard deviation, greater absolute accuracy in energy calibration, and, most importantly, measurements of the adsorption of lower vapor-pressure materials which would have previously been impossible. These improvements are accomplished by: (1) using an electron beam evaporator instead of a Knudsen cell to generate the metal vapor at the source of the pulsed atomic beam, (2) changing the atomic beam design to decrease the relative amount of optical radiation that accompanies evaporation, (3) adding an off-axis quartz crystal microbalance for real-time measurement of the flux of the atomic beam during calorimetry experiments, and (4) adding capabilities for in situ relative diffuse optical reflectivity determinations (necessary for heat signal calibration). These improvements are not limited to adsorption calorimetry during metal deposition, but also could be applied to better study film growth of other elements and even molecular adsorbates.

Sellers, Jason R. V.; James, Trevor E.; Hemmingson, Stephanie L.; Farmer, Jason A.; Campbell, Charles T., E-mail: campbell@chem.washington.edu [Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)

2013-12-15

442

Adsorption calorimetry during metal vapor deposition on single crystal surfaces: increased flux, reduced optical radiation, and real-time flux and reflectivity measurements.  

PubMed

Thin films of metals and other materials are often grown by physical vapor deposition. To understand such processes, it is desirable to measure the adsorption energy of the deposited species as the film grows, especially when grown on single crystal substrates where the structure of the adsorbed species, evolving interface, and thin film are more homogeneous and well-defined in structure. Our group previously described in this journal an adsorption calorimeter capable of such measurements on single-crystal surfaces under the clean conditions of ultrahigh vacuum [J. T. Stuckless, N. A. Frei, and C. T. Campbell, Rev. Sci. Instrum. 69, 2427 (1998)]. Here we describe several improvements to that original design that allow for heat measurements with ~18-fold smaller standard deviation, greater absolute accuracy in energy calibration, and, most importantly, measurements of the adsorption of lower vapor-pressure materials which would have previously been impossible. These improvements are accomplished by: (1) using an electron beam evaporator instead of a Knudsen cell to generate the metal vapor at the source of the pulsed atomic beam, (2) changing the atomic beam design to decrease the relative amount of optical radiation that accompanies evaporation, (3) adding an off-axis quartz crystal microbalance for real-time measurement of the flux of the atomic beam during calorimetry experiments, and (4) adding capabilities for in situ relative diffuse optical reflectivity determinations (necessary for heat signal calibration). These improvements are not limited to adsorption calorimetry during metal deposition, but also could be applied to better study film growth of other elements and even molecular adsorbates. PMID:24387440

Sellers, Jason R V; James, Trevor E; Hemmingson, Stephanie L; Farmer, Jason A; Campbell, Charles T

2013-12-01

443

Comparison of extracellular and net glucose oxidation measured isotopically and by indirect calorimetry during high and low glucose turnover  

SciTech Connect

To determine the extent to which glucose oxidation measured by indirect calorimetry reflects glucose oxidation measured isotopically, subjects were studied during a 6-h hyperinsulinemic euglycemic clamp (1 mU.kg-1.min-1) and during infusion of saline. (6-{sup 14}C)glucose was infused on both occasions. Breath was collected for determination of the specific activity of carbon dioxide, oxygen consumption, and carbon dioxide production. Glucose turnover during hyperinsulinemia was approximately eightfold higher than during saline infusion. During the final 1.5 h of the hyperinsulinemic glucose clamp, oxidation measured isotopically remained slightly but consistently lower (P less than 0.05) than that measured by indirect calorimetry (13.8 +/- 1.1 vs 16.5 +/- 1.7 mumol.kg-1.min-1, respectively). In contrast, during the saline infusion, glucose oxidation measured isotopically did not differ from that measured by indirect calorimetry (8.3 +/- 0.6 vs 7.2 +/- 2.8 mumol.kg-1.min-1, respectively). We conclude that although net glucose oxidation measured isotopically was slightly lower than that measured by indirect calorimetry, both techniques provide similar estimates of glucose oxidation over a wide range of glucose disposal.

McMahon, M.M.; Marsh, H.M.; Rizza, R.A. (Mayo Clinic, Rochester, MN (USA))

1991-05-01

444

Effects of salts on the gel-sol transition of gellan gum by differential scanning calorimetry and thermal scanning rheology  

Microsoft Academic Search

The rheological and thermal properties of sodium form gellan gum solutions with and without sodium chloride, potassium chloride, calcium chloride and magnesium chloride were studied by dynamic viscoelastic measurement and differential scanning calorimetry. Temperature dependence of the loss modulus for gellan gum solutions of lower concentrations without salt showed a one step-like change at a certain temperature, however that for

Emako Miyoshi; Tomohisa Takaya; Katsuyoshi Nishinari

1995-01-01

445

Laser Raman, XRD, DSC and Ac-Impedance Analysis of Polymer Blend Electrolyte Based on Eco-Friendly Pva-Pvp Blend with NH4NO3  

NASA Astrophysics Data System (ADS)

Proton conducting polymer blend electrolytes have attractive interest because of their advantages such as processability, flexibility, electrochemical stability, easy handling and their applications to a variety of electrochemical devices such as fuel cells, chemical sensor and electrochemical displays. In the present work, the films of 50PVA-50PVP blend with different MWt% concentrations of NH4NO3 have been prepared by solution casting techniques using distilled water as a solvent. The prepared films have been investigated by different techniques such as XRD, DSC, Laser Raman and AC Impedance spectroscopy. XRD studies reveal the amorphous nature of the polymer blend-salt complexes. The glass transition temperature has been calculated from the DSC analysis. From the AC Impedance spectroscopy, the high conductivity of the 30MWt% of NH4NO3 doped 50PVA-50PVP polymer complex has been found to be the order of 1.41 × 10-3S cm-1 at room temperature.

Rajeswari, N.; Selvasekarapandian, S.; Prabaharan, S. R. S.; Kawamura, J.; Iwai, Y.; Karthikeyan, S.

2013-07-01

446

Hydrolysis of post-consume poly(ethylene terephthalate) with sulfuric acid and product characterization by WAXD, 13C NMR and DSC  

Microsoft Academic Search

Post-consume PET was hydrolysed with commercial sulfuric acid (96%) with varying reaction times (5–120min). The structure of the material obtained was analysed by 13C NMR, DSC, and WAXD and the results were correlated with reaction time. 13C NMR shows a decrease in chain size with reaction time and an increase in the number of carboxyl groups at the end of

Gizilene M. de Carvalho; Edvani C. Muniz; Adley F. Rubira

2006-01-01

447

Acid hydrolysis of native and annealed wheat, potato and pea starches—DSC melting features and chain length distributions of lintnerised starches  

Microsoft Academic Search

Annealing (one and two step) slightly decreased the susceptibility of potato starches to acid hydrolysis (lintnerisation, 2.2M HCl, 35 °C); however, it hardly affected that of wheat and pea starches. Annealing had a very pronounced effect on DSC gelatinisation of wheat, potato and pea starches: endothermic peaks narrowed and shifted to a higher temperature. However, already after 10.5h of acid

Heidi Jacobs; Relinde C Eerlingen; Nathalie Rouseu; Paul Colonna; Jan A Delcour

1998-01-01

448

A study of pyrolysis and pyrolysis products of flame-retardant cotton fabrics by DSC, TGA, and PY–GC–MS  

Microsoft Academic Search

Study of thermal decompositions of cotton and flame-retardant cotton fabrics can assist understanding of fire-resistant functions of the materials. In this research, differential scanning calorimeter (DSC), thermogravimetric analysis (TGA) and pyrolysis–gas chromatography–mass spectroscopy (PY–GC–MS) were employed to investigate decomposition processes and decomposed products of flame-retardant treated (using an organo-phosphorus compound) and untreated cotton fibers in the pyrolysis. The thermal decomposition

Ping Zhu; Shuying Sui; Bing Wang; Kai Sun; Gang Sun

2004-01-01

449

Differential Scanning Calorimetry Study of Ordinary Portland Cements Mixed with fly Ash and Slag  

NASA Astrophysics Data System (ADS)

The study of the thermal behavior (DSC) of hydration products in ordinary Portland cement (OPC), as a function of water cement ratios (W/C) (0.2, 0.25, … 0.4), and the partial substitution of (35 % fly ash), (35 % slag) and (35 % fly ash + 35 % slag) to the OPC system by weight separately was carried out. It was found that the additive materials (pozzlans) increase its durability when added to the OPC. The most important effects in the cement paste microstructure are the changes in pore structure produced by the reduction in the grain size caused by the pozzlanic reactions. The study revealed that the changes in all the thermal parameters depend on the variation of W/C ratios. The systematic changes in the activation energy through all systems occur at (0.3) W/C in the phase (C-H) and (0.35) W/C in the phase (C-S-H). This means that at these ratios of W/C the two phases (C-H) and (C-S-H) further accelerated the process of cement hydration reactions, and at the same time the addition to OPC system may provide enough space for hydration products to be distributed uniformly.

Al-Salami, A. E.; Ahmed, M. A.; Al-Hajry, A.; Taha, S.

2005-03-01

450

Structureenergy relations in hen egg white lysozyme observed during refolding from a quenched unfolded statew  

E-print Network

-and-refold approach and provided proof-of-concept using differential scanning calorimetry (DSC).5 In conventional DSC with DSC, detection of stages during refolding is possible.5 Here, we show that combining DSC and IR offers

451

Discolored1 (DSC1) is an ADP-Ribosylation Factor-GTPase Activating Protein Required to Maintain Differentiation of Maize Kernel Structures.  

PubMed

The embryo and endosperm are the products of double fertilization and comprise the clonally distinct products of angiosperm seed development. Recessive mutations in the maize gene discolored1 (dsc1) condition inviable seed that are defective in both embryo and endosperm development. Here, detailed phenotypic analyses illustrate that discolored mutant kernels are able to establish, but fail to maintain, differentiated embryo, and endosperm structures. Development of the discolored mutant embryo and endosperm is normal albeit delayed, prior to the abortion and subsequent degeneration of all differentiated kernel structures. Using a genomic fragment that was previously isolated by transposon tagging, the full length dsc1 transcript is identified and shown to encode an ADP-ribosylation factor-GTPase activating protein (ARF-GAP) that co-localizes with the trans-Golgi network/early endosomes and the plasma membrane during transient expression assays in N. benthamiana leaves. DSC1 function during endomembrane trafficking and the maintenance of maize kernel differentiation is discussed. PMID:22666226

Takacs, Elizabeth M; Suzuki, Masaharu; Scanlon, Michael J

2012-01-01

452

Structural (XRD) and thermal (DSC, TGA) and BET analysis of materials derived from non-metal cation pentaborate salts.  

PubMed

The synthesis, structural characterization (XRD), and thermal properties of nine non-metal cation (NMC) pentaborate anion salts, [NMC][B(5)O(6)(OH)(4)] (1a-1i) is described (NMC = [NH(3)CMe(2)(CH(2)OH)](+) (a), [O(CH(2)CH(2))(2)NH(2)](+) (b), [NH(3)CMe(CH(2)OH)(2)](+) (c), [2-(2-CH(2)CH(2)OH)PyH](+) (d), [(CH(2))(4)NH(CH(2)CH(2)OH)](+) (e), [(CH(2))(5)NH(CH(2)CH(2)OH)](+) (f), [2-MeImid](+) (g), [Me(3)NCMe(2)(CH(2)OH)](+) (h), [O(CH(2)CH(2))(2)NMe(2)](+) (i). Single-crystal X-ray diffraction studies on all compounds show that they contain isolated pentaborate anions, H-bonded together in a supramolecular array, with the cations occupying the cavities within the network. Compound 1c was obtained as a partial hydrate (0.16H(2)O). TGA and DSC analysis (in air, 25-1000 degrees C) indicate that compounds 1a-1i thermally decompose via a 2 stage process to B(2)O(3). The first stage (<250 degrees C) is dehydration to condensed polymeric pentaborates {approximate composition: [NMC][B(5)O(8)] (2a-2i)}. Five condensed pentaborates (2a-c, 2e, 2g) were synthesised and characterized by powder XRD and BET analysis. These condensed pentaborates were amorphous. The isolated pentaborates intumesced at approximately 600 degrees C (occupying approximately 10 times their original volume), and then contracted back to black glassy B(2)O(3) solids at 1000 degrees C. The intumescent materials (3a), (3b), (3e), (3g), and a final B(2)O(3) sample (4b) were synthesised and isolated and their porosities determined. BET surface area analysis on the isolated pentaborates (1a-c, 1e, 1g), the condensed pentaborates (2a-c, 2e, 2g), intumesced materials (3a, 3b, 3e, 3g), and B(2)O(3) (4b) showed that they were all 'non-porous' (<1.59 m(2) g(-1)). PMID:20372719

Beckett, Michael A; Horton, Peter N; Hursthouse, Michael B; Knox, David A; Timmis, James L

2010-04-28

453

Application of Differential Scanning Calorimetry to Evaluate Thermal Properties and Study of Microstructure of Biodegradable Films  

NASA Astrophysics Data System (ADS)

The glass transition temperature ( T g) and melting temperature ( T m) of gelatin-starch films were determined using differential scanning calorimetry. Also, the microstructure was observed using scanning electron microscopy (SEM) and the crystalline structure by means of X-ray diffraction (XRD). The effect of starch and glycerol concentrations in films on the thermal properties was evaluated through response surface methodology (RSM). The highest values of T m were obtained at starch concentration intervals of (0.26 to 0.54) %w/w and glycerol concentrations lower than 0.5 (%w/w). On the other hand, the T g values diminished as the glycerol concentration increased. Mathematical models for both transitions were fitted to the experimental data. The micrographs obtained by SEM show the influence of glycerol in the microstructure of the films, being more “gummy” as the content of the plasticizer increased. The XRD patterns of the films demonstrate the existence of some pseudo-crystalline regions in the biodegradable materials.

Aguilar-Méndez, M. A.; Martin-Martínez, E. San; Ortega-Arroyo, L.; Cruz-Orea, A.

2010-03-01

454

A 450-day light curve of the radio afterglow of GRB 970508: Fireball calorimetry  

E-print Network

We report on the results of an extensive monitoring campaign of the radio afterglow of GRB 970508, lasting 450 days after the burst. The spectral and temporal radio behavior indicate that the fireball has undergone a transition to sub-relativistic expansion at t~100 days. This allows us to perform "calorimetry" of the explosion. The derived total energy, ~5\\times 10^{50} erg, is well below the ~5\\times 10^{51} erg inferred under the assumption of spherical symmetry from gamma-ray and early afterglow observations. A natural consequence of this result, which can also account for deviations at t<100 days from the spherical relativistic fireball model predictions, is that the fireball was initially a wide-angle jet of opening angle ~30 degrees. Our analysis also allows to determine the energy fractions carried by electrons and magnetic field, and the density of ambient medium surrounding the fireball. We find that during the sub-relativistic expansion electrons and magnetic field are close to equipartition, and that the density of the ambient medium is ~1/cm^3. The inferred density rules out the possibility that the fireball expands into a strongly non-uniform medium, as would be expected, e.g., in the case of a massive star progenitor.

D. A. Frail; E. Waxman; S. R. Kulkarni

1999-10-18

455

Accurate temperature model for absorptance determination of optical components with laser calorimetry  

SciTech Connect

In the international standard (International Organization for Standardization 11551) for measuring the absorptance of optical components (i.e., laser calorimetry), the absorptance is obtained by fitting the temporal behavior of laser irradiation-induced temperature rise to a homogeneous temperature model in which the infinite thermal conductivity of the sample is assumed. In this paper, an accurate temperature model, in which both the finite thermal conductivity and size of the sample are taken into account, is developed to fit the experimental temperature data for a more precise determination of the absorptance. The difference and repeatability of the results fitted with the two theoretical models for the same experimental data are compared. The optimum detection position when the homogeneous model is employed in the data-fitting procedure is also analyzed with the accurate temperature model. The results show that the optimum detection location optimized for a wide thermal conductivity range of 0.2-50W/m{center_dot}K moves toward the center of the sample as the sample thickness increases and deviates from the center as the radius and irradiation time increase. However, if the detection position is optimized for an individual sample with known sample size and thermal conductivity by applying the accurate temperature model, the influence of the finite thermal conductivity and sample size on the absorptance determination can be fully compensated for by fitting the temperature data recorded at the optimum detection position to the homogeneous temperature model.

Wang Yanru; Li Bincheng

2011-03-20

456

Sub-picowatt resolution calorimetry with niobium nitride thin-film thermometer  

NASA Astrophysics Data System (ADS)

High-resolution calorimetry has many important applications such as probing nanoscale thermal transport and studying the thermodynamics of biological and chemical systems. In this work, we demonstrated a calorimeter with an unprecedentedly high resolution at room temperature using a high-performance resistive thermometry material, niobium nitride (NbNx). Based on a theoretical analysis, we first showed that the heat flux resolution of a resistive-thermometry based calorimeter depends on the parasitic thermal conductance of the device and the temperature coefficient of resistance (TCR) of the thermometer, when the noise is limited by the Johnson noise. Based on this analysis, we then developed a calorimeter using NbNx as the thermometry material because it possesses both high TCR (˜0.67%/K) and a low thermal conductivity (k ˜ 1.1 W/m K). This calorimeter, when used with the modulated heating scheme, demonstrated an unprecedentedly high power resolution of 0.26 pW at room temperature. In addition, NbNx based resistive thermometry can also be extended to cryogenic temperature, where the TCR is shown to be significantly higher.

Dechaumphai, Edward; Chen, Renkun

2014-09-01

457

Prospects for true calorimetry on Kerr black holes in core-collapse supernovae and mergers  

E-print Network

Observational evidence for black hole spin down has been found in the normalized light curves of long GRBs in the BATSE catalogue. Over the duration $T_{90}$ of the burst, matter swept up by the central black hole is susceptible to non-axisymmetries producing gravitational radiation with a negative chirp. A time sliced matched filtering method is introduced to capture phase-coherence on intermediate timescales, $\\tau$, here tested by injection of templates into experimental strain noise, $h_n(t)$. For TAMA 300, $h_n(f)\\simeq 10^{-21}$ Hz$^{-\\frac{1}{2}}$ at $f=1$ kHz gives a sensitivity distance for a reasonably accurate extraction of the trajectory in the time frequency domain of about $D\\simeq 0.07-0.10$ Mpc for spin fown of black holes of mass $M=10-12M_\\odot$ with $\\tau=1$ s. Extrapolation to advanced detectors implies $D\\simeq 35-50$ Mpc for $h_n(f)\\simeq 2\\times 10^{-24}$ Hz$^{-\\frac{1}{2}}$ around 1 kHz, which will open a new window to rigorous calorimetry on Kerr black holes.

Maurice H. P. M. van Putten; Nobuyuki Kanda; Hideyuki Tagoshi; Daisuke Tatsumi; Fujimoto Masa-Katsu; Massimo Della Valle

2011-01-05

458

AC Calorimetry and Thermophysical Properties of Bulk Glass-Forming Metallic Liquids  

NASA Technical Reports Server (NTRS)

Thermo-physical properties of two bulk metallic glass forming alloys, Ti34Zr11Cu47Ni8 (VIT 101) and Zr57Nb5Ni12.6Al10CU15.4 (VIT 106), were investigated in the stable and undercooled melt. Our investigation focused on measurements of the specific heat in the stable and undercooled liquid using the method of AC modulation calorimetry. The VIT 106 exhibited a maximum undercooling of 140 K in free radiative cooling. Specific heat measurements could be performed in stable melt down to an undercooling of 80 K. Analysis of the specific heat data indicate an anomaly near the equilibrium liquidus temperature. This anomaly is also observed in y the temperature dependencies of the external relaxation time, the specific volume, and the surface tension; it is tentatively attributed to a phase separation in the liquid state. The VIT 101 specimen exhibited a small undercooling of about 50 K. Specific heat measurements were performed in the stable and undercooled melt. These various results will be combined with ground based work such as the measurement of T-T-T curves in the electrostatic levitator and low temperature viscosity and specific heat measurements for modeling the nucleation kinetics of these alloys.

Johnson, William L.

2000-01-01

459

Real-Time Monitoring of Membrane-Protein Reconstitution by Isothermal Titration Calorimetry  

PubMed Central

Phase diagrams offer a wealth of thermodynamic information on aqueous mixtures of bilayer-forming lipids and micelle-forming detergents, providing a straightforward means of monitoring and adjusting the supramolecular state of such systems. However, equilibrium phase diagrams are of very limited use for the reconstitution of membrane proteins because of the occurrence of irreversible, unproductive processes such as aggregation and precipitation that compete with productive reconstitution. Here, we exemplify this by dissecting the effects of the K+ channel KcsA on the process of bilayer self-assembly in a mixture of Escherichia coli polar lipid extract and the nonionic detergent octyl-?-d-glucopyranoside. Even at starting concentrations in the low micromolar range, KcsA has a tremendous impact on the supramolecular organization of the system, shifting the critical lipid/detergent ratios at the onset and completion of vesicle formation by more than 2-fold. Thus, equilibrium phase diagrams obtained for protein-free lipid/detergent mixtures would be misleading when used to guide the reconstitution process. To address this issue, we demonstrate that, even under such nonequilibrium conditions, high-sensitivity isothermal titration calorimetry can be exploited to monitor the progress of membrane-protein reconstitution in real time, in a noninvasive manner, and at high resolution to yield functional proteoliposomes with a narrow size distribution for further downstream applications. PMID:24354292

2013-01-01

460

Thermodynamic analysis of Bacillus subtilis endospore protonation using isothermal titration calorimetry  

NASA Astrophysics Data System (ADS)

Bacterial proton and metal adsorption reactions have the capacity to affect metal speciation and transport in aqueous environments. We coupled potentiometric titration and isothermal titration calorimetry (ITC) analyses to study Bacillus subtilis spore-proton adsorption. We modeled the potentiometric data using a four and five-site non-electrostatic surface complexation model (NE-SCM). Heats of spore surface protonation from coupled ITC analyses were used to determine site specific enthalpies of protonation based on NE-SCMs. The five-site model resulted in a substantially better model fit for the heats of protonation but did not significantly improve the potentiometric titration model fit. The improvement observed in the five-site protonation heat model suggests the presence of a highly exothermic protonation reaction circa pH 7 that cannot be resolved in the less sensitive potentiometric data. From the log Ks and enthalpies we calculated corresponding site specific entropies. Log Ks and site concentrations describing spore surface protonation are statistically equivalent to B. subtilis cell surface protonation constants. Spore surface protonation enthalpies, however, are more exothermic relative to cell based adsorption suggesting a different bonding environment. The thermodynamic parameters defined in this study provide insight on molecular scale spore-surface protonation reactions. Coupled ITC and potentiometric titrations can reveal highly exothermic, and possibly endothermic, adsorption reactions that are overshadowed in potentiometric models alone. Spore-proton adsorption NE-SCMs derived in this study provide a framework for future metal adsorption studies.

Harrold, Zoë R.; Gorman-Lewis, Drew

2013-05-01

461

DCal: A custom integrated circuit for calorimetry at the International Linear Collider  

SciTech Connect

A research and development collaboration has been started with the goal of producing a prototype hadron calorimeter section for the purpose of proving the Particle Flow Algorithm concept for the International Linear Collider. Given the unique requirements of a Particle Flow Algorithm calorimeter, custom readout electronics must be developed to service these detectors. This paper introduces the DCal or Digital Calorimetry Chip, a custom integrated circuit developed in a 0.25um CMOS process specifically for this International Linear Collider project. The DCal is capable of handling 64 channels, producing a 1-bit Digital-to-Analog conversion of the input (i.e. hit/no hit). It maintains a 24-bit timestamp and is capable of operating either in an externally triggered mode or in a self-triggered mode. Moreover, it is capable of operating either with or without a pipeline delay. Finally, in order to permit the testing of different calorimeter technologies, its analog front end is capable of servicing Particle Flow Algorithm calorimeters made from either Resistive Plate Chambers or Gaseous Electron Multipliers.

Hoff, James R.; Mekkaoui, Abderrazek; Yarema, Ray; /Fermilab; Drake, Gary; Repond, Jose; /Argonne

2005-10-01

462

Isothermal calorimetry: a predictive tool to model drug-propellant interactions in pressurized metered dose systems.  

PubMed

The purpose of this work was to evaluate gas perfusion isothermal calorimetry (ITC) as a method to characterize the physicochemical changes of active pharmaceutical ingredients (APIs) intended to be formulated in pressurized metered dose inhalers (pMDIs) after exposure to a model propellant. Spray dried samples of beclomethasone dipropionate (BDP) and salbutamol sulphate (SS) were exposed to controlled quantities of 2H,3H-decafluoropentane (HPFP) to determine whether ITC could be used as a suitable analytical method for gathering data on the behavioural properties of the powders in real time. The crystallization kinetics of BDP and the physiochemical properties of SS were successfully characterized using ITC and supported by a variety of other analytical techniques. Correlations between real and model propellant systems were also established using hydrofluoroalkane (HFA-227) propellant. In summary, ITC was found to be suitable for gathering data on the crystallization kinetics of BDP and SS. In a wider context, this work will have implications on the use of ITC for stability testing of APIs in HFA-based pMDIs. PMID:24325938

Ooi, Jesslynn; Gaisford, Simon; Boyd, Ben J; Young, Paul M; Traini, Daniela

2014-01-30

463

A novel optical calorimetry dosimetry approach applied to an HDR Brachytherapy source  

NASA Astrophysics Data System (ADS)

The technique of Digital Holographic Interferometry (DHI) is applied to the measurement of radiation absorbed dose distribution in water. An optical interferometer has been developed that captures the small variations in the refractive index of water due to the radiation induced temperature increase ?T. The absorbed dose D is then determined with high temporal and spatial resolution using the calorimetric relation D=c?T (where c is the specific heat capacity of water). The method is capable of time resolving 3D spatial calorimetry. As a proof-of-principle of the approach, a prototype DHI dosimeter was applied to the measurement of absorbed dose from a High Dose Rate (HDR) Brachytherapy source. Initial results are in agreement with modelled doses from the Brachyvision treatment planning system, demonstrating the viability of the system for high dose rate applications. Future work will focus on applying corrections for heat diffusion and geometric effects. The method has potential to contribute to the dosimetry of diverse high dose rate applications which require high spatial resolution such as microbeam radiotherapy (MRT) or small field proton beam dosimetry but may potentially also be useful for interface dosimetry.

Cavan, A.; Meyer, J.

2013-06-01

464

Single-strand DNA translation initiation step analyzed by Isothermal Titration Calorimetry  

SciTech Connect

Is single-strand DNA translatable? Since the 60s, the question still remains whether or not DNA could be directly translated into protein. Some discrepancies in the results were reported about functional translation of single-strand DNA but all results converged on a similar behavior of RNA and ssDNA in the initiation step. Isothermal Titration Calorimetry method was used to determine thermodynamic constants of interaction between single-strand DNA and S30 extract of Escherichia coli. Our results showed that the binding was not affected by the nature of the template tested and the dissociation constants were in the same range when ssDNA (K{sub d} = 3.62 {+-} 2.1 x 10{sup -8} M) or the RNA corresponding sequence (K{sub d} = 2.7 {+-} 0.82 x 10{sup -8} M) bearing SD/ATG sequences were used. The binding specificity was confirmed by antibiotic interferences which block the initiation complex formation. These results suggest that the limiting step in translation of ssDNA is the elongation process.

Damian, Luminita, E-mail: luminitadamian@microcal.eu.com [CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse (France) [CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse (France); Universite de Toulouse, UPS, IPBS, F-31077 Toulouse (France); IUB, School of Engineering and Science, D-28727 Bremen (Germany); Marty-Detraves, Claire, E-mail: claire.detraves@free.fr [CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse (France) [CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse (France); Universite de Toulouse, UPS, IPBS, F-31077 Toulouse (France); Winterhalter, Mathias [IUB, School of Engineering and Science, D-28727 Bremen (Germany)] [IUB, School of Engineering and Science, D-28727 Bremen (Germany); Fournier, Didier, E-mail: Didier.Fournier@ipbs.fr [CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse (France) [CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse (France); Universite de Toulouse, UPS, IPBS, F-31077 Toulouse (France); Paquereau, Laurent, E-mail: Laurent.Paquereau@ipbs.fr [CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse (France) [CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse (France); Universite de Toulouse, UPS, IPBS, F-31077 Toulouse (France)

2009-07-31

465

Solid state reaction of Al and Zr in Al/Zr multilayers: A calorimetry study  

SciTech Connect

The exothermic, solid state reaction of Al and Zr has been studied in thick Al/Zr multilayers using Differential Scanning Calorimetry and X-ray diffraction. The multilayer samples were magnetron sputter deposited into highly textured alternate layers of Al and Zr with nominal composition Al{sub 3}Zr. The samples used in this study were 47{mu}m thick with a 427{Angstrom} period. When samples were isochronally scanned from 25 to 725C, a large exotherm at {approximately}350C was followed by one or two smaller exotherms at {approximately}650C. The first exotherm is dominated by a diffusion based reaction of Al and Zr that produces two phases in isochronal scans: amorphous Al-Zr and cubic Al{sub 3}Zr, and two additional phases in isothermal anneals: Al{sub 2}Zr and tetragonal Al{sub 3}Zr. The exothermic heat from this multi-phase reaction is measured using isochronal scans and isothermal anneals, and the heat flow is analyzed using a 1-D diffusion based model. An average activation energy and a diffusion constant are determined. In the isothermal scans, the total exothermic heat increases linearly with {radical}time, and layer thicknesses vary linearly with heat.

Blobaum, K.J.; Weihs, T.P.; Barbee, T.W. Jr.; Wall, M.A.

1995-04-14

466

Solution calorimetry as an alternative approach for dissolution testing of nanosuspensions.  

PubMed

The formulation of poorly soluble drugs as nanocrystals/nanosuspensions has rapidly evolved during the past decade into a mature drug-delivery strategy. The major characteristic of these systems is the high drug dissolution rate, enabling bioavailability enhancement after oral administration. It is therefore of great importance to have access to analytical methodology that is able to accurately monitor the extreme fast dissolution process of such formulations. The aim of the present study was to evaluate solution calorimetry as a novel approach to measure the dissolution rate of nanosuspensions by recording the temperature change in the dissolution vessel during the dissolution process of the nanocrystals. The applicability was tested on different nanosuspensions made up of three model drugs: naproxen, cinnarizine and an investigational API, i.e. compound A. The dissolution process of all nanosuspensions investigated was completed within less than 1 min. During this period, sufficient data points were collected to transform temperature offset data to cumulative heat of solution pointing to the potential of this technique. However, of significant concern is the fact that this technique measures the total heat produced or consumed by all processes that occur during the dissolution, e.g. the heat of mixing when the nanosuspension comes in contact with the dissolution medium. Erroneous conclusions will result if phenomena other than dissolution are not accounted for. PMID:20887787

Kayaert, P; Li, B; Jimidar, I; Rombaut, P; Ahssini, F; Van den Mooter, G

2010-11-01

467

Energetics of genome ejection from phage revealed by isothermal titration calorimetry  

NASA Astrophysics Data System (ADS)

It has been experimentally shown that ejection of double-stranded DNA from phage is driven by internal pressure reaching tens of atmospheres. This internal pressure is partially responsible for delivery of DNA into the host cell. While several theoretical models and simulations nicely