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1

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

2

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

3

Oxidation kinetics of tricresyl phosphate (TCP) using differential scanning calorimetry (DSC)  

Microsoft Academic Search

Oxidation kinetics of tricresyl phosphate (TCP) have been studied using differential scanning calorimetry (DSC). A kinetic model for the oxidation process was evaluated and several kinetic parameters were determined. The oxidation process in TCP appeared to be pseudo first order. Non-isothermal kinetic data was used to estimate isothermal oxidation behavior of TCP. Validity of the predicted isothermal behavior was checked

S. Shankwalkar; D. Placek

1994-01-01

4

Oxidation kinetics of tricresyl phosphate (TCP) using differential scanning calorimetry (DSC)  

SciTech Connect

Oxidation kinetics of tricresyl phosphate (TCP) have been studied using differential scanning calorimetry (DSC). A kinetic model for the oxidation process was evaluated and several kinetic parameters were determined. The oxidation process in TCP appeared to be pseudo first order. Non-isothermal kinetic data was used to estimate isothermal oxidation behavior of TCP. Validity of the predicted isothermal behavior was checked by comparing with actual isothermal DSC measurements. Results indicated that a non-isothermal oxidation profile could be used to reasonably predict the isothermal course of oxidation. Application of this kinetic technique to characterize oxidation of other phosphate esters and lubricants is discussed.

Shankwalkar, S.; Placek, D. [FMC Corp., Princeton, NJ (United States)

1994-03-01

5

Slow structural relaxations of glass-forming Maltitol by modulated DSC calorimetry  

NASA Astrophysics Data System (ADS)

The possibilities offered by the modulated differential scanning calorimetry technique to investigate the glass transition are analyzed and discussed on Maltitol. The technique provides specific tools to follow the structural relaxation in the frequency domain above Tg and in the time domain below Tg. Evidence is obtained that the complex heat capacity can be measured in the course of a routine differential scanning calorimetry (DSC) scan. The enthalpic relaxation can be analyzed which allows us to discuss the fragility degree of the glass former. The smearing effect of the underlying ramp is specifically investigated. It is shown that the method provides estimates both of the Vogel and of the Kauzmann temperatures. It thus offers an attractive way to check for a correlation between dynamics and thermodynamics. The concept of the ``nonreversing'' component is used and discussed in order to study the slow sub-Tg relaxations.

Bustin, O.; Descamps, M.

1999-06-01

6

A new simultaneous apparatus for X-ray diffractometry and differential scanning calorimetry (XRD-DSC)  

Microsoft Academic Search

An instrument was developed for performing simultaneous X-ray diffractometric and differential scanning calorimetric (XRD-DSC) measurement using a power compensation DSC (pc-DSC). The feasibility of the technique is demonstrated by examining the thermal dehydration measurement of zinc formate dihydrate (Zn(HCO2)2·2H2O). The DSC curve shows apparent double endothermic peaks during the dehydration process, while X-ray diffraction analysis indicated that the resulting anhydrous

Tadashi Arii; Akira Kishi; Yuji Kobayashi

1999-01-01

7

Thermal Relaxation of Gelatin and Date Flesh Measured by Isothermal Condition in Differential Scanning Calorimetry (DSC) and its Relation to the Structural and Mechanical Glass Transition  

Microsoft Academic Search

A new innovative method was developed to measure the thermal-relaxation by maintaining isothermal condition in a Differential Scanning Calorimetry (DSC). The DSC thermal-relaxation characteristics of gelatin and date flesh were found to be related with the structural- and mechanical-glass transition measured by conventional DSC linear-heating and thermal-mechanical analysis (i.e, Differential Thermal Mechanical Analysis, DMTA). Initial slope of the thermal relaxation

Mohammad Shafiur Rahman; Ghalib Said Al-Saidi

2010-01-01

8

Increased corneal hydration induced by potential ocular penetration enhancers: assessment by differential scanning calorimetry (DSC) and by desiccation.  

PubMed

The corneal toxicity of some surfactants of possible use as ocular penetration enhancers was investigated by measuring their effect on hydration of rabbit corneas 'in vitro'. The tested substances were benzalkonium chloride (BAC), cetylpyridinium chloride (CPC), ethylenediaminetetraacetic acid disodium salt (EDTA), polyoxyethylene-20-stearyl ether (Brij 78, PSE), polyethoxylated castor oil (Cremophor EL, PCO) and sodium deoxycholate (DC). Freshly excised corneas, mounted in perfusion cells, were kept in contact for 1 h with solutions of these agents; corneal hydration was then evaluated by measuring: (a) their total (free+bound) water content by desiccation (gravimetric analysis); and (b) their free water content by differential scanning calorimetry (DSC). The DSC measurements also provided a rough quantitative estimate of corneal solutes. All tested agents significantly influenced corneal hydration, evidently as a consequence of alteration of the corneal epithelium. Although a brief contact with the precorneal tissues 'in vivo' may not prove harmful, the use of these compounds as potential ocular permeation enhancers or otherwise as ingredients of topical ocular formulations for long-term use should be considered with caution. PMID:11790497

Monti, D; Chetoni, P; Burgalassi, S; Najarro, M; Saettone, M F

2002-01-31

9

Use of Differential Scanning Calorimetry (DSC) in the Characterization of EPDM/PP Blends  

NASA Astrophysics Data System (ADS)

New polyolefinic thermoplastic elastomers based on the ethylene-propylene-diene monomer (EPDM) and polypropylene (PP) containing an EPDM elastomer of the last generation (Nordel NDR 47130), obtained by polymerization in the gaseous phase with metallocene catalysis, were prepared and characterized. The melting and crystallization behavior of these blends was investigated by differential scanning calorimetry. It is observed that the melting temperature, crystallization temperature, and crystallinity degree increase with an increase of PP loading. The influence of the blend composition on the physico-mechanical characteristics was discussed using statistical processing of the experimental data. Two compatibilizing procedures were utilized to improve the physico-mechanical characteristics of the samples: an addition method using different compatibilizing agents and dynamical vulcanization with three types of crosslinking systems. Significant improvements of the tensile strength and tear strength were noted by dynamic crosslinking, and the best results were obtained using a crosslinking system based on phenolic resin and tin chloride.

Stelescu, Maria Daniela; Airinei, Anton; Grigoras, Cristian; Niculescu-Aron, Ileana-Gabriela

2010-12-01

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

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

12

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.

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

2010-01-01

13

Fragility of supercooled liquids from differential scanning calorimetry traces: theory and experiment.  

PubMed

Starting from the Debye model for frequency-dependent specific heat and the Vogel-Fulcher-Tammann (VFT) model for its relaxation time, an analytic expression is presented for the heat capacity versus temperature trace for differential scanning calorimetry (DSC) of glass transitions, suggesting a novel definition of the glass transition temperature based on a dimensionless criterion. An explicit expression is presented for the transition temperature as a function of the VFT parameters and the cooling rate, and for the slope as a function of fragility. Also a generalization of the results to non-VFT and non-Debye relaxation is given. Two unique ways are proposed to tackle the inverse problem, i.e., to extract the fragility from an experimental DSC trace. Good agreement is found between theoretically predicted DSC traces and experimental DSC traces for glycerol for different cooling rates. PMID:22299886

Fivez, J; Longuemart, S; Glorieux, C

2012-01-28

14

DSC ANALYSIS OF FOODBORNE BACTERIA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Differential scanning calorimetry (DSC), which is often used to measure the thermal profiles of lipids, carbohydrates, and proteins in food, is also applicable to studying the thermal properties of bacteria. Foodborne pathogens are inactivated by heat, and denaturation transitions observed by DSC i...

15

Temperature modulated differential scanning calorimetry during isothermal curing of phase separating polymer networks  

Microsoft Academic Search

Temperature modulated differential scanning calorimetry (TMDSC) and conventional differential scanning calorimetry (DSC) have been applied for investigation of isothermal curing of two component polymer networks separating into two phases during network formation. The network component consists of diglycidylether of bisphenol A (DGEBA) cross-linked with diaminodiphenyl methane (DDM) and the linear polymer component is polyethersulfone (PES). Isothermal curing experiments at 373

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

1998-01-01

16

Laboratory annealing experiments of refractory silicate grain analogs using differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

Abstract- 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 g-1, respectively. During the crystallization of forsterite particles, the spectral evolution of the 10 ?m 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; Tsukamoto, Katsuo; Kaito, Chihiro

2011-01-01

17

DSC ANALYSIS OF FOODBORNE BACTERIA  

Technology Transfer Automated Retrieval System (TEKTRAN)

Differential scanning calorimetry, which is often used to measure the thermal profiles of lipids, carbohydrates, and proteins in food, is also applicable to studying the thermal stability of foodborne bacteria. Pathogens are inactivated by heat, and denaturation transitions observed by DSC indicate...

18

Determination and review of specific heat capacity measurements during isothermal cure of an epoxy using TM-DSC and standard DSC techniques  

Microsoft Academic Search

The technique normally used to measure Cp during isothermal cure is Temperature Modulated - Dynamic Scanning Calorimetry TM-DSC. It is however not standardised, experimentally complicated and quite time intensive. As will be shown, Cp may also be estimated during isothermal cure just from using dynamic heating experiments on a fully cured sample. Such values are often sufficient for isothermal heat

J. McHugh; P. Fideu; A. Herrmann; W. Stark

2010-01-01

19

Review of calorimetry in Fermilab fixed-target experiments  

SciTech Connect

The fixed-target program at Fermilab comprises as many as thirteen simultaneous experiments in ten separate beamlines using beams of primary protons, pions, kaons, electrons, neutrinos, and muons. The fixed target beamlines were last in operation in the latter half of 1991, shutting down in 1992. The next fixed target run is scheduled for early 1996. This article describes some of the wide variety of calorimetric devices that were in use in the past run or to be used in the coming run. Special attention is devoted to the new devices currently under construction.

Crisler, M.B.

1995-04-01

20

Initial calorimetry experiments in the Physics Divsion, ORNL (Oak Ridge National Laboratory)  

NASA Astrophysics Data System (ADS)

Four calorimetry experiments were performed with palladium cathode electrolysis cells to investigate the possibility of cold fusion heat production based on the reported results of Fleischmann and Pons. Two of the cells contained 6.35-mm-diam x 10-cm-long palladium cathodes in a 0.2-M (6)LiOD electrolyte; one cell contained a similar cathode in a 0.1-M (6)LiOD electrolyte solution; and one cell used a cast 1.27-cm-diam x 10-cm-long palladium rod in a 0.2-M electrolyte. All four cells were constructed with platinum wire anodes. One of the cells exhibited an apparent 2-3 W power excess for a period of approximately 300 hours of a total operating time of 1800 hours; each of the remaining cells remained in power balance for the 1800 hour period.

Hutchinson, D. P.; Bennett, C. A.; Richards, R. K.; Bullock, J. S., IV; Powell, G. L.

1990-05-01

21

DSC Study of Collagen in Disc Disease  

PubMed Central

Differential scanning calorimetry (DSC) has been used to estimate the effect of disc disease on the collagen helix-coil transition and morphology for tissue extracted from patients during surgical operation. Forty discs were obtained from patients with degenerative disc disease undergoing surgery for low back pain. The patients were in the age between 20 and 70 years old. The specimens were kept wet during DSC experiment. The data allow the comparison between thermal stability of collagen tissue from healthy patients and from patients suffering from disc disease. In the paper the comparison between thermal helix-coil transition for collagen fibers from patients suffering from disc disease and collagen fibers from healthy organisms has been discussed. The heating rate has an influence on the position on denaturation temperatures of collagen in disc tissues. Higher helix-coil transition temperature of collagen in degenerated disc suggests that additional intermolecular cross linking of collagen fibers occurs. Denaturation temperatures of collagen in degenerated male disc possess smaller values than in female ones. Disc disease induces changes in collagen structure and leads to formation of additional crosslinks between collagen fibers.

Skrzynski, S.; Sionkowska, A.; Marciniak, A.

2009-01-01

22

A study of the structural phase transitions in AlF3: X-ray powder diffraction, differential scanning calorimetry (DSC) and Raman scattering investigations of the lattice dynamics and phonon spectrum  

Microsoft Academic Search

The cubic-rhombohedral phase transition at 450 degrees C of AlF3 is studied by DSC, X-ray powder diffraction and Raman scattering. It is demonstrated that the transition is of first order with a hysteresis of about 6 degrees. It is established by X-ray powder diffraction patterns that the room temperature space group is R3c. A temperature study of the Raman scattering

P. Daniel; A. Bulou; M. Rousseau; J. Nouet; J. L. Fourquet; M. Leblanc; R. Burriel

1990-01-01

23

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

24

Application and use of isothermal calorimetry in pharmaceutical development.  

PubMed

There are many steps involved in developing a drug candidate into a formulated medicine and many involve analysis of chemical interaction or physical change. Calorimetry is particularly suited to such analyses as it offers the capacity to observe and quantify both chemical and physical changes in virtually any sample. Differential scanning calorimetry (DSC) is ubiquitous in pharmaceutical development, but the related technique of isothermal calorimetry (IC) is complementary and can be used to investigate a range of processes not amenable to analysis by DSC. Typically, IC is used for longer-term stability indicating or excipient compatibility assays because both the temperature and relative humidity (RH) in the sample ampoule can be controlled. However, instrument design and configuration, such as titration, gas perfusion or ampoule-breaking (solution) calorimetry, allow quantification of more specific values, such as binding enthalpies, heats of solution and quantification of amorphous content. As ever, instrument selection, experiment design and sample preparation are critical to ensuring the relevance of any data recorded. This article reviews the use of isothermal, titration, gas-perfusion and solution calorimetry in the context of pharmaceutical development, with a focus on instrument and experimental design factors, highlighted with examples from the recent literature. PMID:21277961

O'Neill, Michael A A; Gaisford, Simon

2011-01-26

25

Electromagnetic calorimetry  

NASA Astrophysics Data System (ADS)

Electromagnetic calorimetry forms a key element of almost all current high energy particle physics detectors and has widespread application in related experimental fields such as nuclear physics and astro-particle physics. It will play a particularly important role in the latest generation of experiments at the CERN Large Hadron Collider (LHC), where it is expected that high energy electrons and photons will provide some of the clearest signatures for new discoveries. This article introduces the basic concepts underlying electromagnetic calorimetry and illustrates how these principles have been applied in recent and current detector designs, explaining the connection between technical choices and specific physics goals. Designs are described in sufficient detail to demonstrate the compromises that have to be made in achieving optimum performance within practical constraints. The main emphasis is on the LHC experiments, which provide outstanding examples of the state-of-the-art. Selected examples from other domains, such as nuclear physics and neutrino experiments are also considered and particular attention is given to calorimeter design studies for the proposed International Linear Collider (ILC) where the concept of Particle Flow Analysis is being used as a guiding influence in the overall detector optimization.

Brown, R. M.; Cockerill, D. J. A.

2012-02-01

26

Differential scanning calorimetry of porcine adipose tissues  

Microsoft Academic Search

Differential scanning calorimetry (DSC) was used for the direct analysis of melting properties in porcine subcutaneous, intermuscular, and kidney leaf adipose tissue by heating at a constant ratio of +5°C\\/min from 4 to 90°C. Melting curves for adipose tissues as well as fat extracted from the associated tissues by chloroform–methanol were generated using DSC. Major peaks in DSC curves were

K. Sasaki; M. Mitsumoto; T. Nishioka; M. Irie

2006-01-01

27

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

28

Dynamic Calorimetry for Students  

ERIC Educational Resources Information Center

|A student experiment on dynamic calorimetry is described. Dynamic calorimetry is a powerful technique for calorimetric studies, especially at high temperatures and pressures. A low-power incandescent lamp serves as the sample. The ScienceWorkshop data-acquisition system with DataStudio software from PASCO Scientific displays the results of the…

Kraftmakher, Yaakov

2007-01-01

29

Step response analysis in DSC — a fast way to generate heat capacity spectra  

Microsoft Academic Search

A new method of step response analysis in DSC was developed which allows the fast generation of heat capacity spectra. In common temperature modulated calorimetry, like 3?-method, AC-calorimetry and temperature modulated differential scanning calorimetry (TMDSC), periodic perturbations are used to get dynamic heat capacity. In contrary, the proposed method uses a single step in program temperature followed by an isothermal

M. Merzlyakov; C. Schick

2001-01-01

30

Differential scanning calorimetry of protein-lipid interactions.  

PubMed

Differential scanning calorimetry (DSC) is a highly sensitive non-perturbing technique for measuring the thermodynamic properties of thermally induced transitions. This technique is particularly useful for the characterization of lipid/protein interactions. This chapter presents an introduction to DSC instrumentation, basic theory, and methods and describes DSC applications for characterizing protein effects on model lipid membranes. Examples of the use of DSC for the evaluation of protein effects on modulation of membrane domains and membrane stability are given. PMID:23404272

Cañadas, Olga; Casals, Cristina

2013-01-01

31

Thermal analysis of platelet aggregation assessed by differential scanning calorimetry.  

PubMed

Calorimetry is an analytical method that measures heat flow between a heat source and sample. The sample gains or losses heat based on physical or chemical composition. Differential scanning calorimetry (DSC) compares the results of heating a sample to those for heating a reference material. DSC then measures internal energy or a sample's calorific capacity. The aim of this study was to examine the thermal characteristics of platelet activation. Blood was obtained from human volunteers by venipuncture and collected in 5 ml siliconised and citronated vacutainer tubes. Platelet counts were measured using a hemocytometer. Platelet-rich (PRP) or platelet-poor plasma (PPP) was obtained by centrifugation. Ten microliters of PRP or PPP were placed into aluminum pans for DSC with or without activation by epinephrine (5.0 microM) or CaCl2 (50 microM). To avoid a spontaneous activation of platelets samples were kept frozen, after a 5 min period of stabilization, 5 microl of aggregation-inducing agent was added. Scans were initiated at a -12 degrees C after stabilization, with an increase of a 5 degrees C/min to a maximum of 60 degrees C. The experiments were performed on a TA Differential Scanning Calorimeter (New Castle, DE, USA). The difference in heat evolved between the PRP and PPP during the process of platelet activation was 253 J/g. The difference of heat flow in the activation of PRP versus PPP may correspond to an exothermic process involved in platelet aggregation. PMID:22128443

Rivas-Vilchis, José F; Hernández Sánchez, Fernando; Velasco Lezama, Rodolfo

2010-01-01

32

Characterization of monumental carbonate stones by thermal analysis (TG, DTG and DSC)  

Microsoft Academic Search

Thermogravimetry (TG), derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC), were found to be suitable instrumental techniques for the study of monumental rocks because they need small amounts of sample and provide extensive qualitative and quantitative information. From DTG curves, the calcite\\/dolomite ratio in the samples as well as the differences between limestones and dolomites can be quantitatively determined. DSC

L. M. Barcina; A. Espina; M. Suárez; J. R. García; J. Rodríguez

1997-01-01

33

Detection of synergistic interactions of polyvinyl alcohol– cassava starch blends through DSC  

Microsoft Academic Search

The synergistic interaction of polyvinyl alcohol (PVOH) and cassava starch was studied by differential scanning calorimetry (DSC) method. Film of the PVOH–cassava starch blends were prepared by solution cast method. Originally, cassava starch film did not show presence of any endothermic peaks in DSC thermogram. However, after adding PVOH to cassava starch, the PVOH–cassava starch blend films showed obvious endothermic

Lee Tin Sin; W. A. W. A. Rahman; A. R. Rahmat; M. I. Khan

2010-01-01

34

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

35

Effect of aging on glass transformation measurements by temperature modulated DSC  

Microsoft Academic Search

Differential scanning calorimetry (DSC) is a well established technique for studying the glass transformation behavior of glasses and for measuring the glass transition temperature Tg and the relaxation enthalpy ?Hg. However, Tg and ?Hg measurements on glasses from DSC heating scans depend on the thermal history and aging (annealing time at a given temperature below Tg) which makes it difficult

D. Tonchev; S. O. Kasap

2002-01-01

36

Determination of the oxidative stability by DSC of vegetable oils from the Amazonian area  

Microsoft Academic Search

Differential scanning calorimetry (DSC) and a Rancimat method apparatus were applied to evaluate the oxidative stability of buriti pulp oil (Mauritia flexuosa Mart), rubber seed oil (Hevea brasiliensis), and passion fruit oil (Passiflora edulis). The Rancimat measurements taken for the oxidative induction times were performed under isothermal conditions at 100°C and in an air atmosphere. The DSC technique involved the

Juliana J. R. Pardauil; Luiz K. C. Souza; Fábio A. Molfetta; José R. Zamian; Geraldo N. Rocha Filho; C. E. F. da Costa

2011-01-01

37

Gelatinization and retrogradation of 6-year-old korean ginseng starches studied by DSC  

Microsoft Academic Search

Gelatinization and retrogradation characteristics of 6-year-old Korean ginseng starch with different grades were investigated using differential scanning calorimetry (DSC). The 1st and 3rd grade ginseng starches showed typical biphasic DSC endotherm while 2nd grade ginseng starch revealed monophasic DSC endotherm with relatively narrow transition temperature. Although Avrami exponents (n) of all ginseng starches were close to 1.0 (i.e., retrogradation of

Hye-Jin Koo; So-Hee Park; Jae-sun Jo; Byung-Yong Kim; Moo-Yeol Baik

2005-01-01

38

Air Fluorescence Calorimetry with the High Resolution Fly's Eye and Telescope Array Experiments  

SciTech Connect

The air fluorescence technique was first successfully deployed on the Fly's Eye Experiment (1981-1993) by the University of Utah. Its successor, the High Resolution Fly's Eye (HiRes) experiment has further exploited this technique, first in hybrid mode with the MIA muon array (1993-1996), and then in monocular and stereoscopic modes (1997-2006). Results from HiRes will be presented, including evidence for the Greisen-Zatsepin-K'uzmin (GZK) Effect predicted 40 years ago. Most recently, members of the HiRes are collaborating with groups from Japan, led by University of Tokyo, to construct and operate the Telescope Array (TA) experiment, which will deploy a large scintillation-based ground array in combination with fluorescence detectors. Funding for TA in the US has already been approved by NSF. TA will begin operation in 2007.

Jui, Charles C. H. [Department of Physics, University of Utah Salt Lake City, Utah (United States)

2006-10-27

39

A study on the interaction of water and cellulose ethers using differential scanning calorimetry  

Microsoft Academic Search

Differential scanning calorimetry (DSC) has been used to examine the distribution of water within hydroxypropylmethylcellulose 2208 (HPMC K15M) gels. Thermal events were apparent in the DSC scans of HPMC K15M gels which were dependent on their storage time, the concentration of the polymer and the cooling and heating rates utilised during DSC. Two or more thermal events were present on

Conor B. McCrystal; James L. Ford; Ali R. Rajabi-Siahboomi

1997-01-01

40

The 4th International Conference on Calorimetry in High Energy Physics, and visit LEP detectors and the European CP-Violation Experiment at CERN  

NASA Astrophysics Data System (ADS)

The scientific program for the Elba conference was aimed at outlining the state of the art in all aspects of calorimetry applied to high energy physics. A number of lectures were presented at the Elba conference covering the general topics of calorimetry for large experiments, sampling and precision calorimetry, calorimetry with crystals, computer simulations, electronics, and radiation damage of scintillating fibers and materials. There were also reports on the expected performance of particular types of calorimeters in ongoing and future experiments. The Central European Laboratory for Particle Physics Research (CERN) has been engaged in colliding beams, as well as fixed target experiments for a number of years. Some of the exceptional results from the LEP detectors is a testament to the efficient planning and details necessary for today's larger and more complex detectors. Preparation for the next run with these detectors and tests of new fixed target detectors were observed during this visit. In addition, I discussed plans for the operation and use of the CERN (SPS) test beams during the CY-1994.

White, H. B., Jr.

1994-01-01

41

Determination of the oxidative stability by DSC of vegetable oils from the Amazonian area.  

PubMed

Differential scanning calorimetry (DSC) and a Rancimat method apparatus were applied to evaluate the oxidative stability of buriti pulp oil (Mauritia flexuosa Mart), rubber seed oil (Hevea brasiliensis), and passion fruit oil (Passiflora edulis). The Rancimat measurements taken for the oxidative induction times were performed under isothermal conditions at 100°C and in an air atmosphere. The DSC technique involved the oxidation of oil samples in an oxygen-flow DSC cell. The DSC cell temperature was set at five different isothermal temperatures: 100, 110, 120, 130 and 140°C. During the oxidation reaction, an increase in heat was observed as a sharp exothermic curve. The value T(0) represents the oxidative induction time, which is determined from the downward extrapolated DSC oxidative curve verses the time axis. These curves indicate a good correlation between the DSC T(0) and oxidative stability index (OSI) values. The DSC method is useful because it consumes less time and less sample. PMID:21411317

Pardauil, Juliana J R; Souza, Luiz K C; Molfetta, Fábio A; Zamian, José R; Rocha Filho, Geraldo N; da Costa, C E F

2011-03-15

42

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

43

Classical temperature-modulated calorimetry: A review  

Microsoft Academic Search

The historical, methodological and technical development and the applications of temperature-modulated calorimetry (also known as AC calorimetry) are reviewed over the last three decades, up to about 1992. Modulation calorimetry (MC) is compared with other calorimetric methods. Particular emphasis is given to temperature scanning and frequency-dependent heat capacity experiments. Recent advances in MC, in particular the combination of differential scanning

Eberhard Gmelin

1997-01-01

44

Glass transition and crystallization of Mg–Ni–Nd metallic glasses studied by temperature-modulated DSC  

Microsoft Academic Search

Glass transition and crystallization behavior of several Mg–Ni–Nd metallic glasses has been systematically studied by temperature-modulated differential scanning calorimetry (TMDSC). The glass transition transformation of alloys Mg75Ni10Nd15 and Mg77Ni18Ni5, which cannot be detected in conventional differential scanning calorimetry (DSC) heating scans, was observed through TMDSC measurements. It was concluded that the signal of the glass transition on the DSC scans

Z. P. Lu; C. T. Liu; Y. Li

2004-01-01

45

Decomposition of methanol vapour over solid catalyst, measured by DSC  

Microsoft Academic Search

The activity of copper containing catalysts for the formation of methanol from CO and H2 is investigated by DSC measurement of the methanol decomposition. Calibration of the DSC signal can be performed by melting experiments with tin under reaction conditions. Comparison of catalysts is well possible by measurement of the standard activity at 240°, the apparent activation energy for the

G. Hakvoort; Xu Xiaoding

1991-01-01

46

EFFECT OF IRRADIATION ON DIFFERENTIAL SCANNING CALORIMETRIC (DSC) PROFILE OF FLUIDIZED BED DRIED MUTTON  

Microsoft Academic Search

Studies were conducted to evaluate the thermal properties of irradiated fluidised bed dried (FBD) (75°C, 6h) mutton using Differential Scanning Calorimetry (DSC). The samples were subjected to ?-irradiation at Bhabha Atomic Research Centre (BARC), Mumbai to study the effects of different doses of irradiation (0, 2 and 4kGy) on the DSC profile of FBD mutton samples prepared with natural antioxidants

K. Jayathilakan; Khudsia Sultana; K. Radhakrishna; G. K. Sharma

2011-01-01

47

Temperature-modulated DSC provides new insight about nickel-titanium wire transformations  

Microsoft Academic Search

Differential scanning calorimetry (DSC) is a well-known method for investigating phase transformations in nickel-titanium orthodontic wires; the microstructural phases and phase transformations in these wires have central importance for their clinical performance. The purpose of this study was to use the more recently developed technique of temperature-modulated DSC (TMDSC) to gain insight into transformations in 3 nickel-titanium orthodontic wires: Neo

William A Brantley; Masahiro Iijima; Thomas H Grentzer

2003-01-01

48

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

49

Phase Transformations And Dynamics Of 4-Cyano-4?-Pentylbiphenyl (5cb) By Nuclear Magnetic Resonance, Analysis Differential Scanning Calorimetry, And Wideangle X-Ray Diffraction Analysis  

Microsoft Academic Search

The polymorphism of 4-cyano-4?-pentylbiphenyl (5CB) was investigated by means of differential scanning calorimetry (DSC), X-ray diffraction, and proton nuclear magnetic resonance (NMR) experiments. Three new phases has been identified and characterized structurally and dynamically. By a slow cooling at a rate ? 0.2 K\\/min, the nematic phase crystallizes into a phase noted C1. Upon a fastest cooling (?5 K\\/min) a

T. Mansaré; R. Decressain; C. Gors; V. K. Dolganov

2002-01-01

50

Applications of Differential Scanning Calorimetry to the Study of Thermal Energy Storage.  

National Technical Information Service (NTIS)

Differential scanning calorimetry (DSC) is a versatile tool for investigating the behavior of materials that store energy by melting or by undergoing solid-state transitions. Heating scans measure the enthalpy that can be stored and cooling scans yield th...

S. Cantor

1977-01-01

51

Sample encapsulation on glass transition of methylmetacrylate copolymers: TMDSC and DSC studies  

Microsoft Academic Search

The use of modulated temperature differential scanning calorimetry (TMDSC) and differential scanning calorimetry (DSC) in the measurement of the glass transition temperature (T\\u000ag) in polymer-water systems presents several important problems. These include the presence of water evaporation endotherms, partial water evaporation during scanning, changes in pan integrity due to vapour pressure developing in the pan headspace during analysis, and

I. Bravo-Osuna; A. Mu?oz-Ruiz; M. R. Jiménez-Castellanos; J. L. Ford; M. R. Whelan

2002-01-01

52

Cell asymmetry correction for temperature modulated differential scanning calorimetry  

SciTech Connect

The quality of measurement of heat capacity by differential scanning calorimetry (DSC) is based on strict symmetry of the twin calorimeter, which is important for temperature-modulated DSC. Heat capacities for sapphire-filled and empty aluminium calorimeters (pans) under designed cell imbalance caused by different pan-masses were measured. In addition, positive and negative signs of asymmetry were explored by analyzing the phase-shift between temperature and heat flow for sapphire and empty runs. The phase shifts change by more than 18{degree} depending on asymmetry sign. Once the asymmetry sign is determined, the asymmetry correction for modulated DSC can be made.

Ishikiriyama, K.; Wunderlich, B. [Tennessee Univ., Knoxville, TN (United States). Dept. of Chemistry]|[Oak Ridge National Lab., TN (United States)

1996-12-31

53

Evaluation of heat-treated wood swelling by differential scanning calorimetry in relation to chemical composition  

Microsoft Academic Search

Retification is a heat treatment that decreases the swell- ing of wood and increases its resistance to fungal attack. In this study, differential scanning calorimetry (DSC) was applied in order to determine the fibre saturation point (FSP) of natural and retified wood. FSP values were used to determine the total swelling of natural and heat-treated wood. The DSC method was

Vincent Repellin; Departement PCMM; Cours Fauriel

54

Water States in Perfluorosulfonic Acid Membranes Using Differential Scanning Calorimetry  

Microsoft Academic Search

The water states in perfluorosulfonic acid membranes (Nafion®) were evaluated using low temperature differential scanning calorimetry (DSC) on both vapor and liquid penetrants. At low sorption levels, water sorbed in Nafion existed in the nonfreezable bound state until a critical value was reached. The critical, nonfreezable water content corresponded to 4.8 water molecules per sulfonate group. Beyond that critical value,

S. Jessie Lue; Song-Jiang Shieh

2009-01-01

55

Triglyceride specific heat determined by differential scanning calorimetry  

Microsoft Academic Search

The specific heats of the three polymorphic forms of trilaurin, trimyristin, tripalmitin and tristearin have been determined\\u000a by differential scanning calorimetry (DSC). Results from -90 to +100 C for the triglycerides were obtained and compared with\\u000a the literature values determined by classical methods. Agricultural Research Service, US Department of Agriculture.

J. W. Hampson; H. L. Rothbart

1983-01-01

56

Detection of coating waxes on apples by differential scanning calorimetry  

Microsoft Academic Search

In the European Union, beeswax, candelilla wax, carnauba wax and shellac are approved as coating agents for apple surfaces, provided that the coating is clearly stated. For detecting such coatings on apples, differential scanning calorimetry (DSC) was successfully applied. From the thermograms, the temperature at the peak maximum and the phase transition enthalpy were obtained as the main criteria. For

Barbara Ritter; Jörg Schulte; Erhard Schulte; Hans-Peter Thier

2001-01-01

57

Quantitative Thermal Analysis of Poly(butylene Terephthalate) by Temperature-Modulated Differential Scanning Calorimetry  

Microsoft Academic Search

Quantitative thermal analysis is performed on poly(butylene terephthalate), PBT, between 5 and 600 K based on the measured heat capacity by adiabatic calorimertry, standard differential scanning calorimetry (DSC) and temperature-modulated differential scanning calorimetry (TMDSC). Based on the new data, the low temperature heat capacity is linked to the vibrational spectrum, using the ATHAS method to calculate the solid heat capacity

M. Pyda; E. Nowak-Pyda; B. Wunderlich

2004-01-01

58

DSC study and computer modelling of the melting process in ice slurry  

Microsoft Academic Search

In order to understand the non-isothermal melting kinetics in the ice slurry, a differential scanning calorimetry (DSC) was used. Experimental results were compared to those obtained by a numerical simulation in which a general enthalpy method was applied. In this work the ice slurry studied consists of ice particles uniformly dispersed within a water–antifreeze liquid mixture. The effects of the

T. Kousksou; A. Jamil; Y. Zeraouli; J.-P. Dumas

2006-01-01

59

Thermal characterization of HCN polymers by TG–MS, TG, DTA and DSC methods  

Microsoft Academic Search

This paper presents a thermogravimetry (TG) study of hydrogen cyanide polymers, synthesized from the reaction of equimolar aqueous solutions of sodium cyanide and ammonium chloride. Differential thermal analysis (DTA) and differential scanning calorimetry (DSC) were also used to evaluate the thermal behaviour of these black polymers, which play an important role in prebiotic chemistry. A coupled TG–mass spectrometer (MS) system

José L. de la Fuente; Marta Ruiz-Bermejo; Susana Osuna-Esteban

2011-01-01

60

DSC study of mixtures of wheat flour and potato, sweet potato, cassava, and yam starches  

Microsoft Academic Search

Differential scanning calorimetry (DSC) traces at a 30wt% suspension were studied for mixture of wheat flour and following starches: potato (PS), sweet potato (SPS), yam (YS), and cassava (CS) at 10% to 50% starch. In the endothermal transition, the gelatinization peak temperature of the first peak (TP1) was attributed to the wheat flour and that of the second peak (TP2),

I. S. M. Zaidul; N. Absar; S.-J. Kim; T. Suzuki; A. A. Karim; H. Yamauchi; T. Noda

2008-01-01

61

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

62

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

63

DSC study of sucrose melting  

Microsoft Academic Search

An early endothermic peak at ?150°C was observed for crystalline sucrose by differential scanning calorimetry. The enthalpy at this temperature was found to vary with recrystallised sucrose from different sources. The addition of mineral salts to recrystallisation solutions decreased the enthalpy of the peak at around 150°C, whereas the absence of salts increased it. The presence of organic solvents and

Stephen T. Beckett; M. Grazia Francesconi; Peter M. Geary; Grahame Mackenzie; Aurélia P. E. Maulny

2006-01-01

64

Ice premelting during differential scanning calorimetry  

PubMed Central

Premelting at the surface of ice crystals is caused by factors such as temperature, radius of curvature, and solute composition. When polycrystalline ice samples are warmed from well below the equilibrium melting point, surface melting may begin at temperatures as low as -15 degrees C. However, it has been reported (. Biophys. J. 65:1853-1865) that when polycrystalline ice was warmed in a differential scanning calorimetry (DSC) pan, melting began at about -50 degrees C, this extreme behavior being attributed to short-range forces. We show that there is no driving force for such premelting, and that for pure water samples in DSC pans curvature effects will cause premelting typically at just a few degrees below the equilibrium melting point. We also show that the rate of warming affects the slope of the DSC baseline and that this might be incorrectly interpreted as an endotherm. The work has consequences for DSC operators who use water as a standard in systems where subfreezing runs are important.

Wilson, PW; Arthur, JW; Haymet, AD

1999-01-01

65

DMSO-induced dehydration of DPPC membranes studied by x-ray diffraction, small angle neutron scattering and calorimetry.  

National Technical Information Service (NTIS)

The properties of dimethyl sulfoxide (DMSO), a cryoprotector well known for its biological and therapeutic applications, were investigated on lipid membranes by x-ray diffraction, differential scanning calorimetry (DSC) and small angle neutron scattering ...

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

1998-01-01

66

FLUORINE BOMB CALORIMETRY  

Microsoft Academic Search

Techniques which were developed for fluorine bomb calorimetry are ; described. Construction materials, safety measures, manipulation of samples, and ; calorimeter calibration are discussed. Tests carried out on 25 metals and ; metalloids and on 15 inorganic compounds indicated that reactions of 75% of these ; substances with fluorine could be studied calorimetrically. It is concluded that ; fluorine calorimetry

Ward N. Hubbard; Jack L. Settle; Harold M. Feder

1961-01-01

67

X-ray diffraction pattern and DSC curves of the discharge product of the lithium\\/sulfur dioxide battery  

Microsoft Academic Search

The X-ray diffraction pattern for the discharge product of the Li\\/SO2 battery has been determined. The diffraction data for the lithium dithionite (Li2S2O4) is presented in a table. Differential scanning calorimetry (DSC) data have indicated that Li2S2O4 undergoes two endothermic reactions and one exothermic reaction. The DSC data reveal also that Li reacts exothermically with Li2S2O4 at the lower endothermic

D. W. Ernst

1982-01-01

68

Non-isothermal DSC and TG\\/DTG analysis of the combustion of Si?lopi? asphaltites  

Microsoft Academic Search

In this research, non-isothermal combustion and kinetics of Silopi (Turkey) asphaltite samples were investigated by differential\\u000a scanning calorimetry (DSC) and thermogravimetry (TG\\/DTG). A sample size of 10 mg, heating rates of 5, 10, 15 and 20?C min?1 were used in the temperature range of 20–600?C, under air atmosphere. Two reaction regions were observed in DSC curves. The\\u000a first region is

M. V. Kök

2007-01-01

69

Thermodynamic investigations of nitroxoline sublimation by simultaneous DSC-FTIR method and isothermal TG analysis.  

PubMed

To investigate the physicochemical characteristics, thermodynamics, possible sublimation process and kinetics of nitroxoline, differential scanning calorimetry (DSC), isothermal thermogravimetry (TG), and Fourier transform infrared (FTIR) microspectroscopy equipped with a micro hot-stage of DSC microscopy assembly (simultaneous DSC-FTIR method) were used. The DSC result indicates that nitroxoline exhibited a sharp endothermic peak at 182 degrees C with enthalpy of 103.1 J/g due to the melting point of nitroxoline. A sublimation behavior of nitroxoline was found from 129 degrees C by gradual weight loss in TG curve. However, the nonisothermal DSC-FTIR method reveals that the temperature at 95 degrees C was the onset temperature of nitroxoline sublimation. A significant difference between DSC-FTIR method and TG analysis suggests that the simultaneous DSC-FTIR method was more sensitive than that of the TG analysis to detect the beginning temperature of nitroxoline sublimation. The sublimation kinetics of nitroxoline determined by isothermal TG analysis evidenced that the zero-order kinetics was followed over the sublimation time. The sublimation enthalpy correction was also carried out by a group additivity approach for the estimation of heat capacity. The enthalpy of nitroxoline sublimation estimated was 86.14 KJ/mol at 298.15 K. PMID:19530075

Gao, Gau-Yi; Lin, Shan-Yang

2010-01-01

70

DSC study of sucrose melting.  

PubMed

An early endothermic peak at approximately 150 degrees C was observed for crystalline sucrose by differential scanning calorimetry. The enthalpy at this temperature was found to vary with recrystallised sucrose from different sources. The addition of mineral salts to recrystallisation solutions decreased the enthalpy of the peak at around 150 degrees C, whereas the absence of salts increased it. The presence of organic solvents and polysaccharides in solution had a minor effect compared to the inorganic impurities. The peak was also depleted by increasing the amount of stirring and temperature at which recrystallisation was performed. PMID:16916498

Beckett, Stephen T; Francesconi, M Grazia; Geary, Peter M; Mackenzie, Grahame; Maulny, Aurélia P E

2006-08-17

71

Glass Transition of Freeze-concentrated Aqueous Solution of Ascorbic Acid as Studied by Alternating Differential Scanning Calorimetry  

Microsoft Academic Search

Aqueous solutions of ascorbic acid have been shown, using differential scanning calorimetry (DSC), to form glassy states during freezing. Alternating DSC, as a new technique, further helped to assign five thermal events observed during heating of frozen ascorbic acid solutions to complete melting from below Tg?, the temperature for maximal freeze concentration of ascorbic acid in water, as: (i) glass

Astrid Bork Andersen; Leif H. Skibsted

1998-01-01

72

Investigation of glass-ionomer cements using differential scanning calorimetry.  

PubMed

Six commercial glass-ionomer cements commonly used for various dental applications have been investigated using differential scanning calorimetry (DSC). The heat-flow behaviour and heat capacity of the cements were measured during isothermal (at 37 degrees C) setting reactions. The DSC results show that all materials undergo an exothermic setting process, but with different enthalpies of reactions and different heat capacities; there are no remaining endo- or exothermic reactions after the setting of the cement. All materials examined were found to be effective thermal insulators. PMID:15348851

Khalil, S K; Atkins, E D

1998-09-01

73

Mixtures poly(( R )-3-hydroxybutyrate) and poly( l -lactic acid) subjected to DSC  

Microsoft Academic Search

Blends of bacterial poly((R)-3-hydroxybutyrate) (PHB) and poly(l-lactic acid) (PLLA) synthesized by polycondensation of l-lactic acid or by ring-opening polymerization of l-lactide were studied. Miscibility was investigated through both conventional differential scanning calorimetry (DSC) and\\u000a temperature-modulated DSC (TMDSC). PHB and low-molar mass PLLA were miscible in a whole concentration range, and a single\\u000a glass transition temperature was observed. On the other

Lenka Malinova ´; Ji?í Brožek

2011-01-01

74

DSC Study on Phase Transitions and Their Correlation with Properties of Overaged Al-Zn-Mg-Cu Alloys  

NASA Astrophysics Data System (ADS)

This article investigates the phase transitions of complex quaternary Al-Zn-Mg-Cu alloys with Zr addition at overaged conditions. Differential scanning calorimetry (DSC) is employed to quantitatively analyze the phase transformation phenomena of a wide range of 7xxx series alloys through endothermic and exothermic reactions. The DSC observations detailing heat effect peaks and thermal parameters of ?' dissolution contain valuable information on the presence of equilibrium phases and the optimum alloying element contents. Based on DSC experimental data and phase diagrams, the balance of critical properties such as strength and electrical conductivity of Al-Zn-Cu-Mg 7xxx series alloys has been studied by considering the formation, dissolution, and incipient melting of S and T phase, dissolution of ?' phase as well as the formation of ? phase. Nine Al-Zn-Mg-Cu alloys have been studied through microstructural examination and detailed DSC analysis. The correlation between the properties and the DSC data of the selected alloys has been analyzed.

Li, X. M.; Starink, M. J.

2012-06-01

75

Enzyme-Resistant Starch: Studies Using Differential Scanning Calorimetry  

Microsoft Academic Search

Cereal Chem. 70(2):163-170 Factors governing the formation of enzyme-resistant starch (RS) from as measured by differential scanning calorimetry (DSC), were sample- high-amylose maize starch under laboratory conditions were investigated. size-dependent. To determine the stability of RS, samples were preheated Those factors studied included sample size, gel dimensions, number of under conditions similar to those in baking bread: temperatures of 100

L. GRUCHALA; Y. POMERANZ

76

NMR relaxometry and differential scanning calorimetry during meat cooking  

Microsoft Academic Search

By combining simultaneous nuclear magnetic resonance (NMR) T2 relaxometry and differential scanning calorimetry (DSC) on pork samples heated to nine temperature levels between 25 and 75°C, the present study investigates the relationship between thermal denaturation of meat proteins and heat-induced changes in water characteristics. Principal component analysis (PCA) on the distributed 1H NMR T2 relaxation data revealed that the major

Hanne Christine Bertram; Zhiyun Wu; Frans van den Berg; Henrik J. Andersen

2006-01-01

77

Effect of milk protein products on the rheological and thermal (DSC) properties of normal rice starch and waxy rice starch  

Microsoft Academic Search

The effects of four milk protein ingredients, namely skim milk powder (SMP), milk protein concentrate (MPC), sodium caseinate (NaCN) and whey protein isolate (WPI), on the pasting behaviour of a 10% normal rice starch or waxy rice starch solution were assessed using rheological and differential scanning calorimetry (DSC) measurements and confocal scanning laser microscopy (CSLM). It was found that all

Angkana Noisuwan; John Bronlund; Brian Wilkinson; Yacine Hemar

2008-01-01

78

The effect of various potato cultivars at different times during growth on starch content determined by DSC  

Microsoft Academic Search

Differential scanning calorimetry (DSC) was used to determine the starch content of potato dry matter isolated from various cultivars at different times during growth. When potato dry matter was heated in the presence of excess water, a symmetrical endothermic peak resulted, which was similar to the gelatinization peak of pure starch. From the enthalpy value of potato dry matter and

Q. Liu; X. Lu; R. Yada

2005-01-01

79

Thermal properties of poly(ethylene oxide)\\/lauric acid blends: A SSA–DSC study  

Microsoft Academic Search

A series of poly(ethylene oxide) (PEO)\\/lauric acid blends with different compositions has been prepared and characterised by differential scanning calorimetry (DSC) in dynamic mode. It has been found that the enthalpy of melting and crystallisation reaches its highest value for PEO\\/lauric acid blend (1:1, w\\/w) which makes this system a promising candidate for thermal energy storage applications. Further studies by

Krzysztof Pielichowski; Kinga Flejtuch

2006-01-01

80

DSC study of cold and heat denaturation processes of ?-lactoglobulin A with guanidine hydrochloride  

Microsoft Academic Search

The cold and heat denaturations of bovine P-lactoglobulin A ((?-lg A) has been studied in solutions of guanidine hydrochloride\\u000a (GuHCI) by differential scanning calorimetry (DSC). The experimental results are presented and discussed. It is shown that\\u000a the number of protons bound by the monomeric molecules of ?-lg A was unchanged before and after its heat denaturation below\\u000a pH 3, and

Bangning Wang; Fu Tan

1997-01-01

81

Effect of hydrocolloids on starch thermal transitions, as measured by DSC  

Microsoft Academic Search

Differential scanning calorimetry (DSC) was used to analyze the influence of different hydrocolloids (xanthan, guar, and locust bean gums, carboxymethylcellulose and sodium alginate) on the gelatinization of corn starch in systems with starch concentration ranging between 0.1 and 0.7 g starch\\/g mixture. The reduction of available water produced a shift in gelatinization temperature, especially of the conclusion temperature. The effect

C. Ferrero; M. N. Martino; N. E. Zaritzky

1996-01-01

82

Kinetics and hazards of thermal decomposition of methyl ethyl ketone peroxide by DSC  

Microsoft Academic Search

Differential scanning calorimetry (DSC) was applied to analyze thermal decomposition of methyl ethyl ketone peroxide (MEKPO). Thermokinetic parameters and thermal stability were evaluated. MEKPO decomposes in at least three exothermic decomposition reactions and begins to decompose at 30–32°C. The total heat of decomposition is 1.26±0.03kJg?1. Thermal decomposition of MEKPO can be described by a model of two independent reactions: the

Min-Hao Yuan; Chi-Min Shu; Arcady A. Kossoy

2005-01-01

83

Characterization of water state and distribution in textured soybean protein using DSC and NMR  

Microsoft Academic Search

To explore the role of water during extrusion cooking and the scientific basis for demarcating low-intermediate moisture and high-moisture extrusion technique, soybean protein isolate (SPI) was processed using a pilot-scale twin-screw extruder under 28–60% moisture content and 140–160°C cooking temperature. The state of water in textured soybean protein (TSP) with different treatments were analyzed by using differential scanning calorimetry (DSC)

Feng Liang Chen; Yi Min Wei; Bo Zhang

2010-01-01

84

DMSO produces a new subgel phase in DPPC: DSC and X-ray diffraction study  

Microsoft Academic Search

Equilibrium phases and the kinetics of subgel phase transformation of dipalmitoylphosphatidylcholine (DPPC) hydrated with mixtures of dimethylsulfoxide (DMSO)\\/water have been studied using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The rate of gel-to-subgel transformation is decreased with a small increase in X, the DMSO\\/water mole fraction, but then speeds up and becomes faster than in pure water by X

Stephanie Tristram-Nagle; Tisha Moore; Horia I. Petrache; John F. Nagle

1998-01-01

85

Thermal-oxidative stability of motor gasolines by pressure d.s.c  

Microsoft Academic Search

The thermal-oxidative stability of unleaded motor gasolines of diverse composition and origin were measured using pressure differential scanning calorimetry (p.d.s.c.) in the temperature programmed mode. The samples were exposed to a heating profile of 1°C min?1 under 2000 kPa oxygen pressure from 80°C to 200°C. From the resulting d.s.c. exotherms, the oxidative induction temperature was determined and used for the

Adrian Zanier

1998-01-01

86

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

87

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

88

Differential scanning calorimetry material studies: implications for the safety of lithium-ion cells  

Microsoft Academic Search

Differential scanning calorimetry (DSC) has been demonstrated to be a useful means of studying the reactivity of materials used in lithium-ion cells. In the present study, the reactivity of three most commonly used transition metal oxides. i.e. LixNiO2, LixCoO2, LixMn2O4, in the presence of electrolyte were investigated by DSC. The most commonly used negative electrode material, carbon (LixC6) was also

Z. Zhang; D. Fouchard; J. R. Rea

1998-01-01

89

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

90

The heat capacity of polyethylene fibers measured by multi-frequency temperature-modulated calorimetry  

Microsoft Academic Search

The apparent heat capacity of polyethylene fibers in the melting region was measured by quasi-isothermal, temperature-modulated differential scanning calorimetry (TMDSC) and compared with results from standard differential scanning calorimetry (DSC) and the solid and liquid thermodynamic heat capacity as references from the ATHAS Data Bank. Using a multi-frequency, complex sawtooth modulation in the quasi-isothermal mode disclosed for the first time

M. Pyda; E. Nowak-Pyda; B. Wunderlich

2006-01-01

91

Scintillator materials for calorimetry  

Microsoft Academic Search

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.

Marvin J. Weber

1994-01-01

92

Differential scanning calorimetry to investigate G-quadruplexes structural stability.  

PubMed

Differential Scanning Calorimetry (DSC) is a straightforward methodology to characterize the energetics of thermally-induced transitions of DNA and other biological macromolecules. Therefore, DSC has been used to study the thermodynamic stability of several nucleic acids structures. G-quadruplexes are among the most important non-canonical nucleic acid architectures that are receiving great consideration. This article reports examples on the contribution of DSC to the knowledge of G-quadruplex structures. The selected case studies show the potential of this method in investigating the structure stability of G-quadruplex forming nucleic acids, and in providing information on their structural complexity. Indeed, DSC can determine thermodynamic parameters of G-quadruplex folding/unfolding processes, but it can also be useful to reveal the formation of multiple conformations or the presence of intermediate states along the unfolding pathway, and to evaluate the impact of chemical modifications on their structural stability. This article aims to show that DSC is an important complementary methodology to structural techniques, such as NMR and X-ray crystallography, in the study of G-quadruplex forming nucleic acids. PMID:23500655

Pagano, Bruno; Randazzo, Antonio; Fotticchia, Iolanda; Novellino, Ettore; Petraccone, Luigi; Giancola, Concetta

2013-03-14

93

Evidence of [eta]' or ordered zone formation in aluminum alloy 7075 from differential scanning calorimetry. [Aluminium alloy 7075  

SciTech Connect

The development of high strength levels in Al-Mg-Zn-(Cu) alloys is dependent on the decomposition of the supersaturated solid solution ([alpha][sub ss]). The equilibrium phase, [eta], and the transition phase, [eta][prime], have compositions Mg(Zn, Al, Cu)[sub 2] and the GP Zones are solute rich clusters. Several authors have presented evidence that there is another precipitate which forms between the GP Zones and [eta][prime], though there is some controversy whether it is crystallographically distinct from the matrix, [eta][prime], or an ordered GP Zone. Regardless of their structure, these particles are seldom observed and are not usually considered in the decomposition of these alloys. Most of the previous observations of these particles have been the result of involved transmission electron microscopic and X-ray scattering experiments. This report shows they may also be detected using differential scanning calorimetry (DSC). Also significant is the fact that the particles were observed in AA 7075, an important commercial alloy. Lloyd and Chaturvedi also saw indications of [eta][prime] or ordered zones using DSC, but the results reported herein are different in several important respects. DSC traces of alloys aged for various times at room temperature and 121 C have shown there is at least one phase which can form during the decomposition of aluminum alloy 7075 that is not usually stated in the decomposition reaction. The results of previous studies suggest they may be ordered GP Zones or [eta][prime].

Bartges, C.W. (Alcoa Technical Center, Alcoa Center, PA (United States))

1993-05-01

94

Isothermal Titration Calorimetry of RNA  

PubMed Central

Isothermal titration calorimetry (ITC) is a fast and robust method to study the physical basis of molecular interactions. A single well-designed experiment can provide complete thermodynamic characterization of a binding reaction, including Ka, ?G, ?H, ?S and reaction stoichiometry (n). Repeating the experiment at different temperatures allows determination of the heat capacity change (?CP) of the interaction. Modern calorimeters are sensitive enough to probe even weak biological interactions making ITC a very popular method among biochemists. Although ITC has been applied to protein studies for many years, it is becoming widely applicable in RNA biochemistry as well, especially in studies which involve RNA folding and RNA-interactions with small molecules, proteins and with other RNAs. This review focuses on best practices for planning, designing, and executing effective ITC experiments when one or more of the reactants is an RNA.

Salim, Nilshad N.; Feig, Andrew L.

2009-01-01

95

Evaluation of integrated Raman-DSC technology in early pharmaceutical development: Characterization of polymorphic systems.  

PubMed

Differential Scanning Calorimetry and Raman spectroscopy are both powerful tools used heavily in pharmaceutical development. For many studies such as polymorph characterization these two techniques are complimentary and provide data on different yet important aspects of material properties when combined together. In this work we describe an integrated Raman-DSC technology that simultaneously generates both DSC thermogram and Raman spectra of the pharmaceutical material being studied. The integrated system consists of a DSC with a Raman fiber optic probe inserted right on top of the sample furnace. The technology integrates synchronized Raman acquisition into DSC scan, enabling collection of molecular and structural information coupled with observation of thermal events. We first establish the technology by optimizing the instrumental set-up that offers relatively high-quality results for simultaneous DSC and Raman data collection. We then demonstrate the application of the technology by studying the polymorphs of d-mannitol, a common pharmaceutical excipient and BMS-A, an investigational drug candidate that exhibits multiple coexisting polymorphs. In both cases, the Raman-DSC technology was able to provide valuable information on the process of phase change and polymorph identification. Although similar information may be obtained by using various characterization techniques together, the integrated Raman-DSC indicated special advantages for industrial development such as high efficiency, material sparing and comprehensive data analysis. Moreover the technology provides an alternative to better correlate real-time phase behavior to molecular understanding. The technology thus has the potential to be used for Process Analytical Technology (PAT) purpose. PMID:23995752

Huang, Jun; Dali, Manisha

2013-08-14

96

Thermal characterization of indinavir sulfate using TG, DSC and DSC-photovisual  

Microsoft Academic Search

The object of the present work is to study the thermal characteristics of indinavir sulfate and to evaluate the quality of\\u000a the raw materials. Indinavir A, B, C and reference samples were obtained from different suppliers and submitted to TG, DSC\\u000a and DSC-photovisual analyses. TG\\/DTG curves indicated a desolvation and dehydration processes and were confirmed by DSC. According\\u000a to the

Rosali Maria Ferreira da Silva; Flávia Patrícia Morais de Medeiros; T. G. Nascimento; R. O. Macêdo; P. J. R. Neto

2009-01-01

97

Application of differential scanning calorimetry in food research and food quality assurance  

Microsoft Academic Search

Differential scanning calorimetry (DSC) is the most widely used thermal analytical technique in food research and it has a great utility in quality assurance of food. Proteins are the most studied food components by thermal analysis including studies on conformation changes of food proteins as affected by various environmental factors, thermal denaturation of tissue proteins, food enzymes and enzyme preparations

J. Farkas; Csilla Mohácsi-Farkas

1996-01-01

98

Application of IR imaging during temperature-modulated differential scanning calorimetry (TMDSC) measurements  

Microsoft Academic Search

In a temperature-modulated differential scanning calorimetry (TMDSC) system, temperatures are measured by thermocouples under the sample and reference furnaces. TMDSC helps to accurately measure temperature during a DSC measurement. It also helps the researcher to establish a more realistic model to calculate heat capacity of various materials. This study examined assumption of temperature gradient in TMDSC characterization. An infrared camera

Hsin Wang; M. Pyda; R. Androsch; Bernhard Wunderlich

2002-01-01

99

Physical and Chemical Analysis of Dielectric Properties and Differential Scanning Calorimetry Techniques on Buriti Oil  

Microsoft Academic Search

Dielectric constant (DC) analysis has been carried out on buriti oil (Mauritia flexuosa), in a scan temperature range of ?100–40°C. Fatty acid characterization was performed by gas crystallography and differential scanning calorimetry (DSC). Interesting physical characteristics were noted in a DC analysis on buriti oil. It revealed five different temperature anomalies, which were studied for the chemical properties of the

A. Garcia-Quiroz; S. G. C. Moreira; A. V. de Morais; A. S. Silva; G. N. da Rocha; P. Alcantara

2003-01-01

100

Applications of differential scanning calorimetry to the study of thermal energy storage  

Microsoft Academic Search

Differential scanning calorimetry (DSC) is a versatile tool for investigating the behavior of materials that store energy by melting or by undergoing solid-state transitions. Heating scans measure the enthalpy that can be stored and cooling scans yield the enthalpy that may be recovered from the material. Exotherms also provide information about supercooling. The automatic and rapid thermal cycling features of

Cantor

1977-01-01

101

Applying differential scanning calorimetry to characterize chemical-protective-clothing materials. Final report  

Microsoft Academic Search

The use of differential scanning calorimetry as a means of evaluating changes in polymers used to manufacture protective clothing was investigated. Separate enclosed Appendices give details of studies dealing with Vitron (R)\\/chlorobutyl laminate. These are preceded by a Summary which gives information dealing with Teflon-coated Nomex (Challenge (TM) 5100). The manner in which DSC graphs were affected by exposing the

Weidenbaum

1991-01-01

102

OXIDATIVE STABILITY OF BIODIESEL BY DYNAMIC MODE PRESSURIZED?DIFFERENTIAL SCANNING CALORIMETRY (P?DSC)  

Microsoft Academic Search

Biodiesel, an alternative diesel fuel made from transesterification of vegetable oils or animal fats, is composed of saturated and unsaturated long?chain fatty acid alkyl esters. During long?term storage, oxidation caused by contact with ambient air presents legitimate concerns for monitoring fuel quality. Extended oxidative degradation can affect kinematic viscosity, cetane number, and acid value of the fuel. This work investigates

R. O. Dunn

103

The tribulations and successes on the road from DSC to TMDSC in the 20th century the prospects for the 21st century  

Microsoft Academic Search

All started with the invention of differential thermal analysis, DTA at the beginning of the 20th century. The tool was qualitative\\u000a in the measurement of heat, but quantitative in measuring temperature. The differential scanning calorimetry, DSC, became\\u000a popular in the 1970s. In certain temperature regions, it could replace even the more precise, but cumbersome, classical technique\\u000a of adiabatic calorimetry. A

Bernhard Wunderlich

2004-01-01

104

Early American studies on respiration calorimetry  

Microsoft Academic Search

Summary W. C. Atwater, student of American food materials, transplanted respiration calorimetry to the United States, following his experience with the subject in the German laboratories of Volt and Rubner. He began construction, in 1892 with the collaboration ofE. B. Rosa, of an instrument capable of accurate measurement of energy and material balances in a human being. This represents one

Aaron J. Ihde; Jerry F. Janssen

1974-01-01

105

A thermochemical study of 5,10,15,20-tetraphenylporphine zinc(II) by rotating bomb combustion calorimetry and by Knudsen effusion experiments  

Microsoft Academic Search

The standard molar enthalpies of combustion {?cHmo(cr)} and formation {?fHmo(cr)} at T= 298.15 K ( po= 0.1 MPa) for the 5,10,15,20-tetraphenyl-21H,23H-porphine zinc (ZnTPP, Chemical Abstracts registry number 14074-80-7), were determined by rotating bomb combustion calorimetry. To dissolve the zinc oxides formed during the combustion reaction, an amount of aqueous solution of nitric acid was put into the bomb at the

Rodrigo Patiño; Myriam Campos; Luis Alfonso Torres

2002-01-01

106

Kinetic asymmetry in the gel-liquid crystalline state transitions of DDAB vesicles studied by differential scanning calorimetry.  

PubMed

Didodecyldimethylammonium bromide (DDAB) (1.0 mM) vesicles in water were investigated by differential scanning calorimetry (DSC) to highlight the existing kinetic asymmetry in the gel-liquid crystalline (LC) state transitions. The experiments were performed in the range of temperature, scan rate and pre-scanning time 5-45 degrees C, 15-90 degrees C/h and 0-16 h, respectively, in the up- and down-scanning modes. Depending on the input parameters and number of heating-cooling cycles, the DSC thermograms exhibit a sharp peak, a broad band or a flat shape. A melting temperature T(m)=15.6-16.0 degrees C, given by the peak position, was obtained independently of the scan rate used in the up-scanning mode. The data reveal that DDAB vesicles exhibit much slower kinetics for the LC to gel state than for the opposite transition. Such an asymmetry is supported by: (a) the absence of peak for shorter pre-scanning times but longer scan rates, (b) the increasing intensity of the DSC peak with increasing pre-scanning time and decreasing scan rate, and (c) the complete absence of peak in the down-scan mode. Longer pre-scanning time, however, yields crystal precipitates due to a Krafft phenomenon, which also reduces the peak intensity. The overall results depend on whether the sample is fresh or not, that is, after some heating-cooling cycles, the melting peak requires a longer pre-scanning time to be detected. The kinetic asymmetry explains, for example, the lack of any DSC melting peak reported for "non-fresh" DDAB vesicles, which was as yet unexplained. PMID:20096844

Feitosa, Eloi

2009-12-24

107

Differential scanning calorimetry of blood plasma for clinical diagnosis and monitoring.  

PubMed

Differential scanning calorimetry (DSC) provides a useful method to study the unfractionated plasma proteome. Plasma from healthy individuals yields a reproducible signature thermogram which results from the weighted sum of the thermal denaturation of the most abundant plasma proteins. Further investigation of the thermogram for healthy individuals showed it to be sensitive to ethnicity and gender. DSC analysis of plasma from diseased individuals revealed significant changes in the thermogram which are suggested to result not from changes in the concentration of the major plasma proteins but from interactions of small molecules or peptides with these proteins. Closer examination of the diseased thermograms showed a thermogram characteristic of each disease. For cervical cancer, the DSC method yields a progressively shifted thermogram as the disease advances from pre-invasive conditions to late stage cancer. Our application of the DSC method has provided a potential tool for the early diagnosis, monitoring and screening of cancer patients. PMID:19146849

Garbett, Nichola C; Mekmaysy, Chongkham S; Helm, C William; Jenson, A Bennett; Chaires, Jonathan B

2008-12-16

108

Differential scanning calorimetry characterization of rabbit brain membrane fractions.  

PubMed

Various membrane fractions have been prepared from rabbit brain synaptosomes by centrifugation on discontinuous sucrose gradients after osmotic shock. These fractions were characterized by electron microscopy (E.M.), SDS-PAGE and GABA binding. The fractions were then studied by differential scanning calorimetry (DSC). The calorimetric results indicate that all the fractions studied show thermal transitions at around 60 degrees C which correspond to the "melting" of membrane structures. An additional transition at higher temperature (82 degrees C) seems to be associated with an enrichment in central myelin fragments. PMID:1809740

Cupello, A; Mancardi, G L; Candiano, G; Rialdi, G

1991-11-01

109

Effects of Na 2CO 3 and NaOH on DSC thermal profiles of selected native cereal starches  

Microsoft Academic Search

The effects of Na2CO3 and NaOH (at a concentration of 1 g alkalising agent\\/100 g dry starch) on the gelatinisation properties of 1:4 and 2:3 starch\\/water mixtures were studied using differential scanning calorimetry (DSC). The starches studied included wheat, rice, waxy rice, corn and waxy corn. The addition of Na2CO3 or NaOH resulted in significant increases in transition temperatures (onset,

L. N. Lai; A. Abd Karim; M. H. Norziah; C. C. Seow

2002-01-01

110

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

111

The effects of urea and n-propanol on collagen denaturation: using DSC, circular dicroism and viscosity  

Microsoft Academic Search

The effect of urea and n-propanol on circular dichroism (CD) and viscosity of purified type1 collagen solution at various temperatures and differential scanning calorimetry (DSC) of rat-tail tendon (RTT) collagen fibre have been studied. CD reveals a spectrum with a positive peak at around 220nm and a negative peak at 200nm characteristics of collagen triple helix. The molar ellipticity decreases

R. Usha; T. Ramasami

2004-01-01

112

Dehydration studies of rare earth p-toluenesulfonate hydrates by TG\\/DTG and DSC  

Microsoft Academic Search

The dehydration process of the compounds RE(C7H7SO3)3·xH2O (where x=2 for RE=La–Ho, Tm, Yb and Y; x=7 and 6 for RE=Er and Lu, respectively) has been investigated by thermogravimetry\\/derivative thermogravimetry (TG\\/DTG) and differential scanning calorimetry (DSC) techniques. The TG\\/DTG curves show that the dehydration process does not depend on the atmosphere used. For the compounds of La–Gd, dehydration occurs in a

A. V dos Santos; J. R Matos

2002-01-01

113

DSC studies on structural phase transitions and molecular motions in some A2MCl4 compounds  

NASA Astrophysics Data System (ADS)

Structural phase transitions and molecular motions in (CH3NH3)2CoCl4, (C5H5NH)2ZnCl4, and [(CH3)3CNH3]2ZnCl4 were investigated by differential scanning calorimetry (DSC) between about 130 K and the melting points. All of the compounds showed at least one structural phase transition over the temperature region investigated. The values of the transition entropies obtained suggest that most of the transitions are of the order-disorder type. From these entropy values, thermal motions of the molecules in the highest-temperature solid phases were inferred.

Horiuchi, Keizo

2004-03-01

114

Temperature Modulated DSC of Polymer Crystallization  

Microsoft Academic Search

Polymer crystallization has been analyzed by a new technique of temperature modulated differential scanning calorimetry (TMDSC). The method considers the response of the crystallization kinetics to the temperature modulation in an apparent heat capacity of complex quantity obtained by TMDSC. The isothermal and non-isothermal crystallization of polyethylene and poly(ethylene terephthalate) has been examined experimentally. It has been shown that the

A. Toda; C. Tomita; M. Hikosaka; Y. Saruyama

1998-01-01

115

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

116

Study of the Reversibility in the Crystallization Behavior of Statistical Ethylene/Styrene Copolymers by Classical and Temperature Modulated Differential Scanning Calorimetry  

NASA Astrophysics Data System (ADS)

The crystallization and melting behavior of statistical copolymers of ethylene and styrene (0 - 11 molwere studied using classical and temperature-modulated (TM) differential scanning calorimetry. The evolution of the reversible part of the excess heat capacity was measured during the slowest stage of primary crystallization and during secondary crystallization using TM-DSC in the quasi-isothermal mode. Evolution of the degree of crystallinity and the melting temperature(s) during primary and secondary crystallization was recorded with classical DSC. We will discuss the effect of crystallization temperature and copolymer composition on the primary and secondary crystallization behaviors and show correlations between the evolution of the excess heat capacity, the degree of crystallinity and the melting temperature(s). We will also show that TM-DSC experiments carried under quasi-isothermal conditions enable us to obtain information on the establishment of constraints during secondary crystallization, which can be linked to the evolution of the multiple melting behavior of these copolymers as a function of crystallization time. In turn, these studies shed some light on the relevance of the two existing models of reversible crystallization/melting for secondary crystallization processes by lamellar thickening or by secondary crystal formation.

Huang, Zhenyu; Marand, Herve

2003-03-01

117

Gelatinisation of sago starch in the presence of sucrose and sodium chloride as assessed by differential scanning calorimetry  

Microsoft Academic Search

The inhibitory effect of sucrose and sodium chloride on sago starch gelatinisation was investigated by differential scanning calorimetry (DSC). The temperature of gelatinisation of starch in the presence of low levels of water and high levels of sucrose was found to increase in the presence of sucrose, whereas the gelatinisation enthalpy was unaffected. The gelatinisation temperature range was not as

A. G Maaurf; Y. B Che Man; B. A Asbi; A. H Junainah; J. F Kennedy

2001-01-01

118

WA80 BGO calorimetry electronics  

SciTech Connect

This paper describes instrumentation designed for BGO scintillator-based calorimetry of particles covering a very wide range of energies (from less than 50 MeV to 50 GeV). The instrumentation was designed to have a measurement accuracy of 0.1% over as much of the energy range as possible so the energy resolution of BGO would be the limiting factor. Two 1.5-cm{sup 2} photodiodes were used per 2.5 cm {times} 2.5 cm {times} 25 cm BGO crystal. Both a charge-sensitive preamplifier and a pulse processor were developed specifically for the needs of the WA80 experiment. The preamplifier was designed for high detector capacitance (100 to 700 pF), low integral and differential non-linearity and low power consumption (200 mW). The pulse processor is a time-invariant shaping amplifier with integral peak-detect-and-hold and automatic gain selection circuits. The amplifier use quasi-triangular shaping with 4 {mu}s peaking time, and the hold circuit is gated with a fast first level trigger. The system has more than 20 bits of effective resolution when used with an external 12-bit ADC. Results from beam tests at CERN are presented. 6 refs., 5 figs., 1 tab.

Wintenberg, A.L.; Britton, C.L. Jr.; Ericson, M.N.; Maples, R.A.; Young, G.R.; Awes, T.C.

1991-10-31

119

Statistical analysis of plasma thermograms measured by differential scanning calorimetry.  

PubMed

Melting curves of human plasma measured by differential scanning calorimetry (DSC), known as thermograms, have the potential to markedly impact diagnosis of human diseases. A general statistical methodology is developed to analyze and classify DSC thermograms to analyze and classify thermograms. Analysis of an acquired thermogram involves comparison with a database of empirical reference thermograms from clinically characterized diseases. Two parameters, a distance metric, P, and correlation coefficient, r, are combined to produce a 'similarity metric,' ?, which can be used to classify unknown thermograms into pre-characterized categories. Simulated thermograms known to lie within or fall outside of the 90% quantile range around a median reference are also analyzed. Results verify the utility of the methods and establish the apparent dynamic range of the metric ?. Methods are then applied to data obtained from a collection of plasma samples from patients clinically diagnosed with SLE (lupus). High correspondence is found between curve shapes and values of the metric ?. In a final application, an elementary classification rule is implemented to successfully analyze and classify unlabeled thermograms. These methods constitute a set of powerful yet easy to implement tools for quantitative classification, analysis and interpretation of DSC plasma melting curves. PMID:20961680

Fish, Daniel J; Brewood, Greg P; Kim, Jong Sung; Garbett, Nichola C; Chaires, Jonathan B; Benight, Albert S

2010-09-29

120

An NMR, DSC and X-ray investigation of the disaccharides sucrose, maltose and lactose  

NASA Astrophysics Data System (ADS)

Polycrystalline samples of anhydrous sucrose and the monohydrates of ?-lactose and ?-maltose have been studied by using nuclear magnetic resonance, differential scanning calorimetry and X-ray diffraction methods. The results show that, apart from twofold reorientations of water molecules, these lattices are fairly rigid below room temperature. The NMR results in the case of sucrose and lactose reveal that above room temperature molecular motions reduce the dipolar interactions to almost zero, even below the melting points. In each of these compounds an endothermic DSC peak occurs at approximately 421 K. Proton T1 and T1? values change noticeably in the vicinity of this temperature. Interpretation of the results leads to the conclusion that these DSC peaks are not associated with the loss of water, but are most likely due to the breaking of hydrogen bonds. A similar DSC peak was not observed in the case of ?-maltose, while the NMR results show that molecular motions start to reduce the dipolar interactions much closer to the melting point than in the other two compounds.

Reynhardt, E. C.

121

Interactions of Starch and Sugar Water Measured by Electron Spin Resonance and Differential Scanning Calorimetry  

Microsoft Academic Search

Cereal Chem. 67(3):286-291 Electron spin resonance (ESR) was used to evaluate the mobility of of water was reduced or after heat treatment of starch-sugar-water mix- water in starch-water mixtures (12-50% H2 0); ESR and differential scan- tures. The sugars progressively raised the temperature of starch gelatiniza- ning calorimetry (DSC) were used to study the effect of different sugars tion measured

J. M. JOHNSON; E. A. DAVIS; J. GORDON

122

A new thermostat\\/cryostat technique for conventional and temperature-modulated differential scanning calorimetry  

Microsoft Academic Search

We present a new top-loading vacuum insulated thermostat\\/cryostat for temperature-modulated differential scanning calorimetry (TMDSC) and DSC measurements covering an outstanding temperature range. TMDSC measurements are now possible down to 60 K. As a consequence of its construction features, contamination by moisture is completely eliminated. In particular, the important time domain technique can be applied without any time limit, thus allowing

Jan K. Krüger; Klaus-Peter Bohn; Andrä le Coutre; Patrick Mesquida

1998-01-01

123

Optimum Condition for Accurate Heat Capacity Measurements in Temperature-Modulated Differential Scanning Calorimetry  

SciTech Connect

We explored the optimum conditions in modulation of the program temperature and sample preparation to obtain absolute values of heat capac- ity from quasi-isothermal measurements of temperature-modulated differen- tial scanning calorimetry. A Mettler-Toledo 820 calorimeter and Perkin-Elmer DSC 7 were used for this work, using saw-tooth modulation as well as sinu- soidal modulation. We adopted a simple model to analyze the temperature response of the calorimeters and calibrated the results more precisely.

Androsch, R.J.; Moon, K.; Wunderlich, B.

1998-09-12

124

Temperature Modulated DSC of Polymer Crystallization  

NASA Astrophysics Data System (ADS)

Polymer crystallization has been analyzed by a new technique of temperature modulated differential scanning calorimetry (TMDSC). The method considers the response of the crystallization kinetics to the temperature modulation in an apparent heat capacity of complex quantity obtained by TMDSC. The isothermal and non-isothermal crystallization of polyethylene and poly(ethylene terephthalate) has been examined experimentally. It has been shown that the temperature dependence of crystal growth rate is obtainable from the imaginary part of the apparent heat capacity and the exothermic heat flow of crystallization. The values determined by TMDSC well agreed with the results of growth rate measurements by optical microscopy.

Toda, A.; Tomita, C.; Hikosaka, M.; Saruyama, Y.

1998-03-01

125

Temperature-modulated DSC provides new insight about nickel-titanium wire transformations.  

PubMed

Differential scanning calorimetry (DSC) is a well-known method for investigating phase transformations in nickel-titanium orthodontic wires; the microstructural phases and phase transformations in these wires have central importance for their clinical performance. The purpose of this study was to use the more recently developed technique of temperature-modulated DSC (TMDSC) to gain insight into transformations in 3 nickel-titanium orthodontic wires: Neo Sentalloy (GAC International, Islandia, NY), 35 degrees C Copper Ni-Ti (Ormco, Glendora, Calif) and Nitinol SE (3M Unitek, Monrovia, Calif). In the oral environment, the first 2 superelastic wires have shape memory, and the third wire has superelastic behavior but not shape memory. All wires had cross-section dimensions of 0.016 x 0.022 in. Archwires in the as-received condition and after bending 135 degrees were cut into 5 or 6 segments for test specimens. TMDSC analyses (Model 2910 DSC, TA Instruments, Wilmington, Del) were conducted between -125 degrees C and 100 degrees C, using a linear heating and cooling rate of 2 degrees C per min, an oscillation amplitude of 0.318 degrees C with a period of 60 seconds, and helium as the purge gas. For all 3 wire alloys, strong low-temperature martensitic transformations, resolved on the nonreversing heat-flow curves, were not present on the reversing heat-flow curves, and bending appeared to increase the enthalpy change for these peaks in some cases. For Neo Sentalloy, TMDSC showed that transformation between martensitic and austenitic nickel-titanium, suggested as occurring directly in the forward and reverse directions by conventional DSC, was instead a 2-step process involving the R-phase. Two-step transformations in the forward and reverse directions were also found for 35 degrees C Copper Ni-Ti and Nitinol SE. The TMDSC results show that structural transformations in these wires are complex. Some possible clinical implications of these observations are discussed. PMID:14560268

Brantley, William A; Iijima, Masahiro; Grentzer, Thomas H

2003-10-01

126

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

127

The influence of cholesterol on the main phase transition of unilamellar dipalmytoylphosphatidylcholine vesicles. A differential scanning calorimetry and iodine laser T-jump study.  

PubMed Central

The influence of cholesterol (CHOL) on the main phase transition in single shell dipalmytoylphosphatidylcholine (DPPC) vesicles was investigated in equilibrium and kinetic experiments. CHOL increases the optical density and causes a slight hysteresis in turbidity transition curves. Static fluorescence anisotropy measurements showed interesting differences for three probes sensing different parts in the hydrophobic region of the phospholipid bilayer. Differential scanning calorimetry (DSC) peaks can be separated into a narrow and a broad component. The narrow component, which decreases linearly with increasing CHOL content and disappears at 20 mol %, is attributed to the transition of free phospholipid, while the broad component, being associated with the transition of CHOL-lipid units, increases monotoniously from 0 to 20%. Kinetic experiments were performed on our iodine-laser T-jump arrangement with turbidity detection. Three cooperative relaxation signals in the microsecond and millisecond time range were detected for pure DPPC vesicles as well as vesicles containing 7.5 and 16.5 mol % CHOL. All three relaxation processes were changed by CHOL: the superposition of the three relaxation amplitudes can be separated into a narrow and a broad component, as in DSC experiments. A speculative model is presented which assumes an inhomogeneous CHOL distribution fluctuating on a millisecond time scale in the temperature region of the main phase transition.

Genz, A; Holzwarth, J F; Tsong, T Y

1986-01-01

128

DSC of etched aluminum foils for use in electrolytic capacitors  

Microsoft Academic Search

A DSC method for evaluating the surface area of etched Al foils for use in high performance electrolytic capacitors is presented.\\u000a A linear relationship between the etching degree (effective surface area) and the thermal resistance of the sample is obtained\\u000a by means of DSC, based on the transient phenomenon. This method using the transient state in DSC measurement is not

R. Ozao; H. Ogura; M. Ochiai; S. Tsutsumi

1997-01-01

129

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

130

CALORIMETRY OF OPEN ELECTROCHEMICAL CELLS  

Microsoft Academic Search

A special case of calorimetry of open electrochemical cells, that employing adiabatic enclosures, is examined. Conditions for an experimental realization of such enclosures is discussed in detail. Practi- cal arrangement and method for data collection are presented. Following the announcement by Fleischmann and Pons(1) that anomalous effects, among them excess heat generation, can be observed when deuterium is electrochemically compressed

S. Szpak; P. A. Mosier

131

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

132

MOLECULAR CHARACTERIZATION AND FUNCTIONAL EXPRESSION OF THE DSC1 CHANNEL  

PubMed Central

Drosophila Sodium Channel 1 (DSC1) was predicted to encode a sodium channel based on a high sequence similarity with vertebrate and invertebrate sodium channel genes. However, BSC1, a DSC1 ortholog in Blattella germanica, was recently shown to encode a cation channel with ion selectivity towards Ca2+. In this study, we isolated a total of 20 full-length cDNA clones that cover the entire coding region of the DSC1 gene from adults of D. melanogaster by reverse transcription-polymerase chain reaction. Sequence analysis of the 20 clones revealed nine optional exons, four of which contain in-frame stop codons; and 13 potential A-to-I RNA editing sites. The 20 clones can be grouped into eight splice types and represent 20 different transcripts because of unique RNA editing. Three variants generated DSC1 currents when expressed in Xenopus oocytes. Like the BSC1 channel, all three functional DSC1 channels are permeable to Ca2+ and Ba2+, and also to Na+ in the absence of external Ca2+. Furthermore, the DSC1 channel is insensitive to tetrodotoxin, a potent and specific sodium channel blocker. Our study shows that DSC1 encodes a voltage-gated cation channel similar to the BSC1 channel in B. germanica. Extensive alternative splicing and RNA editing of the DSC1 transcripts suggest the molecular and functional diversity of the DSC1 channel.

Zhang, Tianxiang; Liu, Zhiqi; Song, Weizhong; Du, Yuzhe; Dong, Ke

2011-01-01

133

Multivariate analysis of DSC–XRD simultaneous measurement data: a study of multistage crystalline structure changes in a linear poly(ethylene imine) thin film  

Microsoft Academic Search

A multivariate analytical technique has been applied to the analysis of simultaneous measurement data from differential scanning\\u000a calorimetry (DSC) and X-ray diffraction (XRD) in order to study thermal changes in crystalline structure of a linear poly(ethylene\\u000a imine) (LPEI) film. A large number of XRD patterns generated from the simultaneous measurements were subjected to an augmented\\u000a alternative least-squares (ALS) regression analysis,

Hiroyuki Kakuda; Tetsuo Okada; Makoto Otsuka; Yukiteru Katsumoto; Takeshi Hasegawa

2009-01-01

134

A study of the oxidation behavior of CrN and CrAlN thin films in air using DSC and TGA analyses  

Microsoft Academic Search

Freestanding CrNx and Cr1?xAlxN films with two different Al atomic percentages with respect to the metal sublattice (x=0.23 and x=0.60) were produced by pulsed closed field unbalanced magnetron sputtering (P-CFUBMS). The dynamic oxidation behavior of the films has been characterized by thermal analysis using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The structure of the films at different thermal-annealing

J. Lin; B. Mishra; J. J. Moore; W. D. Sproul

2008-01-01

135

A new method based on the non-isothermal kinetic equation to estimate the critical temperature of thermal explosion for energetic materials using non-isothermal DSC  

Microsoft Academic Search

A method for estimating the critical temperature of thermal explosion for energetic materials using differential scanning\\u000a calorimetry (DSC) measurement is derived from the Semenov’s thermal explosion theory and the non-isothermal kinetic equation\\u000a based on Harcourt-Esson’s kinetic equation. The result obtained from this method coincides completely with that of the Hu-Yang-Liang-Wu\\u000a method.

Hai Zhang; Jun-ying Hu; Rong-zu Hu; Feng-qi Zhao; Hong-xu Gao

2011-01-01

136

Polymorphism of 2-nitroaniline studied by calorimetric (DSC), structural (X-ray diffraction) and spectroscopic (FT-IR, Raman, UV–Vis) methods  

Microsoft Academic Search

The separation and growth methods of three ortho-nitroaniline (o-NA) polymorphs were found. The irreversible character of the ??? and ??? phase transitions was revealed by differential scanning calorimetry (DSC) measurements and microscopic hot stage observations. The X-ray structure of the ?-form was determined and compared with the ? phase structure solved by Daneshwar et al. [N.N. Daneshwar et al. Acta

Tomasz Zych; Tomasz Misiaszek; M. Magdalena Szostak

2007-01-01

137

Thermal analyser and micro FT-IR/DSC system used to determine the protective ability of microencapsulated squid oil.  

PubMed

Squid oil was microencapsulated by spray drying method. Gelatin, sodium caseinate, maltodextrin were contained in spray drying formulation with or without lecithin and microcrystalline cellulose (Avicel). The thermal stability of the unencapsulated and encapsulated squid oils was determined by pressure differential scanning calorimetry (PDSC), Fourier transform infrared (FT-IR) microscopic photometer with DSC system and themogravimetric analysis (TGA). The results indicate that the above analytical apparatus is an easy and reliable method to investigate the samples and that the microcapsule prepared by spray-dried formulation with lecithin as an emulsifier and Avicel as a stabilizer exhibits more stable thermal stability and longer shelf-life. PMID:7629659

Lin, S Y; Hwang, L S; Lin, C C

138

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

2013-03-05

139

WA80 BGO calorimetry electronics  

Microsoft Academic Search

The authors describe instrumentation designed for BGO scintillator-based calorimetry of particles covering a very wide range of energies (from less than 50 MeV to 50 GeV). The instrumentation was designed to have a measurement accuracy of 0.1% over as much of the energy range as possible so that the energy resolution of BGO would be the limiting factor. Two 1.5-cm2

A. L. Wintenberg; M. N. Ericson; R. A. Maples; G. R. Young; T. C. Awes

1991-01-01

140

Thermal stability of porcine pepsin influenced by Al(III) ion: DSC study  

NASA Astrophysics Data System (ADS)

Differential scanning calorimetry (DCS) has been used to determine thermodynamic profile of pepsin and the in vitro effect of Al(III) ions. Thermograms of pepsin unfolding in the presence and absence of aluminum were used to determine the binding constant, K L, in the pepsin-aluminium model system. The thermodynamic parameters were derived from DSC profiles at different ligand concentrations (1, 5 and 10 mM). The temperatures of thermal transitions ( T m), calorimetric (? H cal) and van't Hoff enthalpy (? H VH), Gibbs free energy, ?(? G), of Al(III) binding to pepsin, as well as an average number of ligands bound to the native protein, were obtained from DSC profiles too. Temperature-dependent changes in the protein structure were also monitored by native PAGE electrophoresis. Increasing the temperature causes the decrease in electrophoretic mobility. Increase in concentration of Al(III) decelerate the migration of pepsin samples on concentration dependent manner. Analysis showed that ligand binding increases thermal stability of protein.

Pavelki?, V. M.; Beljanski, M. V.; Anti?, K. M.; Babi?, M. M.; Brdari?, T. P.; Gop?evi?, K. R.

2011-12-01

141

Structure of rat skin after application of electret characterized by DSC  

NASA Astrophysics Data System (ADS)

Polypropylene (PP) electrets with surface potential of -500V, -1000V and -2000V were prepared by constant voltage corona charging. The electrets were applied to excised rat skin for 2 hours respectively and then the skin samples were analyzed with the differential scanning calorimetry (DSC) technique to study the alteration of lipid organization of the skin. There were three peaks at 63°C, 82.7°C and 115.1°C in the DSC spectra for rat skin untreated, which have been assigned essentially to lipid, lipid-protein and protein alterations. For -500V electret treated-skin sample, only a single peak appeared at 79.1°C. With the increase of electret surface potential from -500V to -2000V, the transition temperature and peak areas at moderate decreased first and then increased. The negative electret could result in the transition of stratum corneum (SC) lipid from gel to liquid crystal and protein transition from ? helix structure to ? folding structure. The regulation action of electret to skin mircostructure presented an effect of "potential window".

Cui, L. L.; Liang, Y. Y.; Dong, F. J.; Ma, L.; Tu, Y.; Liu, H. Y.; Jiang, J.

2011-06-01

142

Effect of harvesting stress and storage conditions on protein degradation in fillets of farmed gilthead seabream ( Sparus aurata): A differential scanning calorimetry study  

Microsoft Academic Search

A trial was undertaken to evaluate Differential Scanning Calorimetry (DSC) as a fast analytical tool to differentiate gilthead seabream subjected to variable conditions of slaughter stress and post-mortem storage. Fish were subjected to different harvesting stress conditions: profound anaesthesia (PA, low stress) and net crowding (NC, high stress). Fish were slaughtered in an ice-salt water slurry, and subsequently stored on

Elisabete Matos; Tomé S. Silva; Teresa Tiago; Manuel Aureliano; Maria Teresa Dinis; Jorge Dias

2011-01-01

143

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

144

Differential scanning calorimetry studies of sebum models.  

PubMed

Human sebum is a mixture of triglycerides, fatty acids, wax esters, squalene, cholesterol, and cholesterol esters. P. acnes, a bacterium that is normally found on the skin, hydrolyzes certain triglycerides to fatty acids, thereby changing the sebum composition. The objective of this study was to examine the physical state of a model sebum and the effect of variations in its composition on its physical properties including (a) the carbon chain length of the components, (b) the ratio of unsaturated to saturated components, and (c) the ratio of triglycerides to fatty acids. A model sebum mixture was prepared based on a composition reported in the literature and evaluated by differential scanning calorimetry (DSC). Since cholesterol and cholesterol esters contribute insignificantly to sebum composition, they were not included. Squalene was kept constant (13%), while the concentration of the rest of the components was varied. Variations of sebum were prepared by dissolving all components in a 3:1 chloroform-methanol mixture for uniformity. Subsequently the solvent was evaporated at room temperature. The samples were then analyzed using DSC. Four distinct endotherms (namely, Mp-1, Mp-2, Mp-3, and Mp-4) were observed between -50 degrees C and 100 degrees C. Mp-1 and Mp-2 occurred below 0 degrees C and were contributed by unsaturated components. Mp-3 and Mp-4, which represent the saturated components, occurred above 30 degrees C. Thus, at normal skin temperature (skin surface temperature is 32 degrees C), sebum contains both a solid and a liquid phase. All the transition temperatures increased with an increase in carbon chain length for the same ratio of unsaturation to saturation. A replacement of unsaturated components with corresponding saturated components led to a decrease in the transition temperatures for the former (Mp-1 and Mp-2) and an increase in the transition temperatures for the latter (Mp-3 and Mp-4). Replacement of triglycerides with corresponding fatty acids (mimicking the action of anaerobic bacteria) caused an increase in Mp-2 and a decrease in Mp-4. In all cases, the final melting temperature (Mp-4) was greater than the temperature of the human skin surface (32 degrees C); thus components contributing to these endotherms are still solids at skin temperature. All variations in the sebum model led to mixtures of solids and liquids at skin temperature. Considering a reduction in Mp-3 and/or Mp-4 to represent sebum "fluidization," it was achieved by a decrease in carbon chain length, an increase in unsaturation, or a substitution of triglycerides by corresponding fatty acids. Preferential enrichment with the saturated species will lead to enrichment of solids versus liquids in the sebum, presumably making it difficult for the liquid phase to dissolve the solids. It seems plausible that perturbation of the balance of solid and liquid components of sebum, such as by P. acnes action, may lead to blockage of the follicle. Future research will investigate strategies to dissolve and/or liquify the solid phase of sebum. PMID:11479654

Motwani, M R; Rhein, L D; Zatz, J L

145

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

146

Determination of the precipitation kinetics of Ni 3Al in the Ni–Al system using differential scanning calorimetry  

Microsoft Academic Search

With the aim of establishing the kinetics of ?? precipitation in the Ni–Al system, quantitative differential scanning calorimetry (DSC) has been used to determine the evolution of enthalpy at cooling rates of 5, 10 and 20 K min?1 for alloys of nominal composition 13.0, 14.2, 15.8 and 18.5 at.% Al. A theoretical model for the reaction has been constructed in

M. P. Jackson; M. J. Starink; R. C. Reed

1999-01-01

147

Thermal analysis of palm mid-fraction, cocoa butter and milk fat blends by differential scanning calorimetry  

Microsoft Academic Search

Commercial samples of anhydrous milk fat (AMF), Ivory Coast cocoa butter (CB) and palm mid-fraction (PMF) were blended in\\u000a a ternary system. The melting characteristics of the blends were studied by differential scanning calorimetry (DSC). Results\\u000a suggest that in the studies of interaction involving more than two fats, partial area (Ai) under the melting peak should be converted to partial

P. S. Dimick

1994-01-01

148

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

149

Derivation of Temperature-Modulated DSC Thermal Conductivity Equations  

Microsoft Academic Search

One of the benefits of temperature-modulated DSC (TMDSC) is its ability to measure thermal conductivity and thermal diffusivity\\u000a without DSC cell modifications or additional accessories. Thermal conductivity of solid materials from 0.1 to about 1 W m-1 K-1 measured. Applications of this approach have been discussed in the literature but no description is yet available concerning\\u000a the derivation of the

R. L. Blaine; S. M. Marcus

1998-01-01

150

DSC deconvolution of the structural complexity of c-MYC P1 promoter G-quadruplexes.  

PubMed

We completed a biophysical characterization of the c-MYC proto-oncogene P1 promoter quadruplex and its interaction with a cationic porphyrin, 5,10,15,20-tetra(N-methyl-4-pyridyl)porphyrin (TMPyP4), using differential scanning calorimetry, isothermal titration calorimetry, and circular dichroism spectroscopy. We examined three different 24-mer oligonucleotides, including the wild-type (WT) sequence found in the c-MYC P(1) promoter and two mutant G?T sequences that are known to fold into single 1:2:1 and 1:6:1 loop isomer quadruplexes. Biophysical experiments were performed on all three oligonucleotide sequences at two different ionic strengths (30 mM [K(+)] and 130 mM [K(+)]). Differential scanning calorimetry experiments demonstrated that the WT quadruplex consists of a mixture of at least two different folded conformers at both ionic strengths, whereas both mutant sequences exhibit a single two-state melting transition at both ionic strengths. Isothermal titration calorimetry experiments demonstrated that both mutant sequences bind 4 mols of TMPyP4 to 1 mol of DNA, in similarity to the WT sequence. The circular dichroism spectroscopy signatures for all three oligonucleotides at both ionic strengths are consistent with an intramolecular parallel stranded G-quadruplex structure, and no change in quadruplex structure is observed upon addition of saturating amounts of TMPyP4 (i.e., 4:1 TMPyP4/DNA). PMID:21402034

Dettler, Jamie M; Buscaglia, Robert; Le, Vu H; Lewis, Edwin A

2011-03-16

151

DSC Deconvolution of the Structural Complexity of c-MYC P1 Promoter G-Quadruplexes  

PubMed Central

We completed a biophysical characterization of the c-MYC proto-oncogene P1 promoter quadruplex and its interaction with a cationic porphyrin, 5,10,15,20-tetra(N-methyl-4-pyridyl)porphyrin (TMPyP4), using differential scanning calorimetry, isothermal titration calorimetry, and circular dichroism spectroscopy. We examined three different 24-mer oligonucleotides, including the wild-type (WT) sequence found in the c-MYC P1 promoter and two mutant G?T sequences that are known to fold into single 1:2:1 and 1:6:1 loop isomer quadruplexes. Biophysical experiments were performed on all three oligonucleotide sequences at two different ionic strengths (30 mM [K+] and 130 mM [K+]). Differential scanning calorimetry experiments demonstrated that the WT quadruplex consists of a mixture of at least two different folded conformers at both ionic strengths, whereas both mutant sequences exhibit a single two-state melting transition at both ionic strengths. Isothermal titration calorimetry experiments demonstrated that both mutant sequences bind 4 mols of TMPyP4 to 1 mol of DNA, in similarity to the WT sequence. The circular dichroism spectroscopy signatures for all three oligonucleotides at both ionic strengths are consistent with an intramolecular parallel stranded G-quadruplex structure, and no change in quadruplex structure is observed upon addition of saturating amounts of TMPyP4 (i.e., 4:1 TMPyP4/DNA).

Dettler, Jamie M.; Buscaglia, Robert; Le, Vu H.; Lewis, Edwin A.

2011-01-01

152

Thermal dissection of lentil seedling amine oxidase domains by differential scanning calorimetry.  

PubMed

The relationships between the structural and energetic domains of lentil seedling amine oxidase (LSAO) were investigated using modifiers that target the active site and the carbohydrate moiety of the enzyme. An irreversible inhibitor, aminoguanidine, specifically modified the active site of the lentil enzyme, whereas sodium metaperiodate cleaves carbohydrate moieties covalently bound to the native enzyme. Differential scanning calorimetry (DSC) measurements were made on the modified LSAOs. Deconvolution of the reversible thermal DSC profiles of the modified enzyme gave three subpeaks (energetic domains), each of which was assigned to one of the three structural domains of the native protein. Our results led us to conclude that deglycosylation of LSAO has no effect on thermal stability, whereas binding of the inhibitor imparts more stability to the enzyme. PMID:17617729

Moosavi-Movahedi, Ali Akbar; Amani, Mojtaba; Moosavi-Nejad, Seyedeh Zahra; Hashemnia, Sedigheh; Ahmad, Faizan; Floris, Giovanni; Mura, Anna; Rezaei-Tavirani, Mostafa; Hakimelahi, Gholam Hossein; Saboury, Ali Akbar; Yousefi, Reza

2007-07-07

153

Application of IR imaging during temperature-modulated differential scanning calorimetry (TMDSC) measurements  

NASA Astrophysics Data System (ADS)

In a temperature-modulated differential scanning calorimetry (TMDSC) system, temperatures are measured by thermocouples under the sample and reference furnaces. TMDSC helps to accurately measure temperature during a DSC measurement. It also helps the researcher to establish a more realistic model to calculate heat capacity of various materials. This study examined assumption of temperature gradient in TMDSC characterization. An infrared camera was used to obtain surface temperature maps of DSC cells during temperature sweeps. TMDSC units from Perkin-Elmer and TA Instrument were studied using different heating and cooling rates. Temperature gradient exists between the top and bottom of the sample. IR images showed that temperature distributions within the sample and reference cells exist. Phase lags between the top and bottom temperatures were also observed.

Wang, Hsin; Pyda, M.; Androsch, R.; Wunderlich, Bernhard

2002-03-01

154

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

1995-01-01

155

The effects of structural recovery and thermal lag in temperature-modulated DSC measurements  

Microsoft Academic Search

It is well known that structural recovery in polymeric glass formers leads to the enthalpy overshoot in nonisothermal experiments. One common model for describing this phenomenon is the Tool-Narayanaswamy-Moynihan (TNM) equation. Here we apply the TNM equation to analyze a typical temperature-modulated DSC (TMDSC) trace and examine the influence of the material nonlinearities on the dynamic heat flow. We show

Sindee L. Simon; Gregory B. McKenna

1997-01-01

156

A new thermostat/cryostat technique for conventional and temperature-modulated differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

We present a new top-loading vacuum insulated thermostat/cryostat for temperature-modulated differential scanning calorimetry (TMDSC) and DSC measurements covering an outstanding temperature range. TMDSC measurements are now possible down to 60 K. As a consequence of its construction features, contamination by moisture is completely eliminated. In particular, the important time domain technique can be applied without any time limit, thus allowing precise 0957-0233/9/11/012/img1 measurements even in the immediate vicinity of phase transitions. Experimental results are presented to show the performance of the modified TMDSC system.

Krüger, Jan K.; Bohn, Klaus-Peter; le Coutre, Andrä; Mesquida, Patrick

1998-11-01

157

Combination of TREF, high-temperature HPLC, FTIR and HPer DSC for the comprehensive analysis of complex polypropylene copolymers.  

PubMed

A novel, powerful analytical technique, preparative temperature rising elution fractionation (prep TREF)/high-temperature (HT)-HPLC/Fourier transform infrared spectroscopy (FTIR)/high-performance differential scanning calorimetry (HPer DSC)), has been introduced to study the correlation between the polymer chain microstructure and the thermal behaviour of various components in a complex impact polypropylene copolymer (IPC). For the comprehensive analysis of this complex material, in a first step, prep TREF is used to produce less complex but still heterogeneous fractions. These chemically heterogeneous fractions are completely separated by using a highly selective chromatographic separation method-high-temperature solvent gradient HPLC. The detailed structural and thermal analysis of the HPLC fractions was conducted by offline coupling of HT-HPLC with FTIR spectroscopy and a novel DSC method-HPer DSC. Three chemically different components were identified in the mid-elution temperature TREF fractions. For the first component, identified as isotactic polypropylene homopolymer by FTIR, the macromolecular chain length is found to be an important factor affecting the melting and crystallisation behaviour. The second component relates to ethylene-propylene copolymer molecules with varying ethylene monomer distributions and propylene tacticity distributions. For the polyethylene component (last eluting component in all semi-crystalline TREF fractions), it was found that branching produced defects in the long crystallisable ethylene sequences that affected the thermal properties. The different species exhibit distinctively different melting and crystallisation behaviour, as documented by HPer DSC. Using this novel approach of hyphenated techniques, the chain structure and melting and crystallisation behaviour of different components in a complex copolymer were investigated systematically. PMID:23612870

Cheruthazhekatt, Sadiqali; Pijpers, Thijs F J; Mathot, Vincent B F; Pasch, Harald

2013-04-24

158

Radiation effects on front-end electronics for noble liquid calorimetry.  

National Technical Information Service (NTIS)

Front-end electronics for liquid ionization chamber calorimetry at hadron collider experiments may be exposed to substantial levels of ionizing radiation and neutron fluences in a cryogenic environment. Measurements of devices built with rad-hard technolo...

M. Citterio S. Rescia V. Radeka

1994-01-01

159

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

Microsoft Academic Search

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.

Carl Salter; James B. Foresman

1998-01-01

160

Study on the melting and freezing behaviour of high temperature binary eutectic fixed points using differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

We have measured the heat flux accompanying the melting or freezing of metal (or metalloid)-carbon eutectics, using differential scanning calorimetry (DSC) to identify appropriate binary systems for secondary thermometry fixed points. Well-known alloy systems such as Fe-C and Ni-C showed reproducible endothermic and exothermic peaks that represent melting and freezing reactions in the DSC measurement. Furthermore, a new Si-C system with a eutectic composition showed reproducible melting and freezing peaks in the DSC measurements. Based on the results by DSC, we identified the Si-SiC eutectic point as a possible eutectic fixed point. To confirm this possibility, we made a Si-SiC cell for thermocouple thermometry and measured its melting and freezing characteristics using a Pt/Pd thermocouple. The melting temperature of the Si-SiC eutectic was reproducible to within 0.02 °C (one standard deviation). From the results, we found that Si-SiC has possibility as a new eutectic fixed point at temperatures around 1400 °C. We also concluded that DSC analysis could be used to measure the reproducibility of freezing and melting reactions that are to be used as fixed points for thermometry, because it is a rapid and easy-to-use tool for characterizing the thermal behaviour of materials with only a small sample.

Kwon, Su Yong; Kim, Yong-Gyoo; Yang, Inseok

2010-06-01

161

Reaction Calorimetry of Fluorine and the Thermochemistry of Its Compounds.  

National Technical Information Service (NTIS)

The importance, the advantages, and the difficulties of using elemental fluorine for reaction calorimetry are discussed. Techniques developed at NBS for bomb calorimetry and gas flame calorimetry with elemental fluorine or fluorine-containing compounds as...

G. T. Armstrong

1976-01-01

162

Manganese carbonyl: heat of formation by rotating-bomb calorimetry  

Microsoft Academic Search

The heat of formation of dimanganese decacarbonyl (Mnâ(CO)ââ) was determined by combustion calorimetry. A rotating-bomb method was employed, and a solution of nitric acid and hydrogen peroxide was used in the bomb to convert all manganese-containing products of combustion to Mn\\/sup + +\\/ ion. The combustion reaction was referred by suitable comparison experiments to an aqueous solution of composition Mn(NOâ)â

W. D. Good; D. M. Fairbrother; G. Waddington

1958-01-01

163

Application of differential scanning calorimetry in evaluation of solid state interactions in tablets containing acetaminophen.  

PubMed

Differential scanning calorimetry (DSC) is an analytical procedure used to determine the differences in the heat flow generated or absorbed by the sample. This method allows to assess purity and polymorphic form of drug compounds, to detect interactions between ingredients of solid dosage forms and to analyze stability of solid formulations. The aim of this study was the assessment of compatibility between acetaminophen (API) and different types of excipients often used in tablets compression: polyvinylpyrrolidone, crospovidone, pregelatinized starch, microcrystalline cellulose and magnesium stearate by differential scanning calorimetry. The study contains results of thermal analysis of excipients and individually performed mixtures of these substances with acetaminophen before and after compression and after 6 months storage of tablets at different temperature and relative humidity conditions (25 +/- 2 degrees C /40 +/- 5% RH, 25 +/- 2 degrees C /60 +/- 5% RH, 40 +/- 2 degrees C /75 +/- 5% RH) for a period of 6 months. To detect possible changes of API chemical structure, gas chromatography-mass spectrometry (GC-MS) was also applied. GC-MS with electron impact ionization (EI) was employed to determine the fragmentation pattern of API. It was shown that the developed formulations showed excellent compatibility among all excipients used except Kollidon CL. The interaction with Kollidon CL is probably a result of a physical reaction as confirmed by GC-MS analyses. Obtained results revealed that DSC can be successfully applied to evaluate possible incompatibilities between acetaminophen and Kollidon. PMID:24147356

Mazurek-Wado?kowska, Edyta; Winnicka, Katarzyna; Czajkowska-Ko?nik, Anna; Czyzewska, Urszula; Miltyk, Wojciech

164

Determination of heat capacity with a sawtooth-type, power-compensated temperature-modulated DSC  

Microsoft Academic Search

The determination of the heat capacity in sawtooth-type, power-compensated temperature-modulated differential scanning calorimetry (TMDSC) by evaluation of the first harmonic of the Fourier transformation of the sample temperature and heat-flow rate is analyzed with experiments and model calculations. At modulation periods below 100s, the measured, uncorrected, absolute value of the complex heat capacity deviates exponentially from the true heat capacity,

R. Androsch; I. Moon; S. Kreitmeier; B. Wunderlich

2000-01-01

165

A survey on lossy compression of DSC raw data  

Microsoft Academic Search

The study investigates the lossy compression of DSC raw data based upon the 12 bit baseline JPEG compression. Computational simulations disclose that JPEG artefacts originate from the quantization of the DCT coefficients. Input noise is shown to serve as an appropriate means to avoid these artefacts. Stimulated by such a noise, the JPEG encoder simply acts as an high frequency

Gregor Fischer; Dietmar Kunz; Katja Köhler

2008-01-01

166

Starch gelatinization under pressure studied by high pressure DSC  

Microsoft Academic Search

The gelatinization process of waxy corn starch under different pressures up to 10.0MPa was investigated using a high pressure DSC. Compressed air and carbon dioxide were used as pressure resources. Effect of pressure and annealing under pressure on gelatinization of waxy corn starch was systematically studied, in particular on the gelatinization temperature and enthalpy. The results show that the peak

Hongsheng Liu; Long Yu; Katherine Dean; George Simon; Eustathios Petinakis; Ling Chen

2009-01-01

167

Temperature modulated DSC at intermediate-low temperatures  

Microsoft Academic Search

In this paper we present a new cooling system for temperature modulated DSC (TMDSC) working down to about 60K. In order to demonstrate the features of this new system in combination with commercial TMDSC apparatus, we present measurements of the specific heat capacity (cp) around the phase transitions of betaine borate and betaine phosphate. For SilGel 604 we report cp

Patrick Mesquida; Andrä le Coutre; Jan K Krüger

1999-01-01

168

An extension of the deontic calculus DSC 1  

Microsoft Academic Search

The chief aim of the paper is to extend the calculusDSC1 (see [4]) in such a way as to satisfy all the requirements listed in [4] as well as a further stipulation — called ‘the principle of uninvolvement’ — to the effect that neither deontic compatibility nor deontic incompatibility of codes (see [2]) should be presupposed in deontic logic.

Leon Guma?ski

1983-01-01

169

DSC study of melting and glass transition in gelatins  

Microsoft Academic Search

In the range from ?50° to +130°C, the temperature dependence of the heat capacity for different kinds of gelatins with water contents of from 2 to 95% was studied by the DSC method. It was shown that, in all studied cases, metastable collagen-like structures are formed in gels or crystalline gelatins, with thermodynamic parameters depending on the formation conditions. The

G. I. Tseretely; O. I. Smirnova

1992-01-01

170

Some elements in specific heat capacity measurement and numerical simulation of temperature modulated DSC (TMDSC) with R\\/ C network  

Microsoft Academic Search

One important application of temperature modulated DSC (TMDSC) is the measurement of specific heat of materials. In this paper, a thermal resistance\\/capacitance (R\\/C) numerical model is used to analyze the effects of experimental parameters and calibration on the measurement of specific heat in TMDSC under isothermal conditions. The actual TMDSC experiments were conducted with sapphire and pure copper samples, respectively.

S. X Xu; Y Li; Y. P Feng

2000-01-01

171

Evaluation of oxidative stability of vegetable oils by monitoring the tendency to radical formation. A comparison of electron spin resonance spectroscopy with the Rancimat method and differential scanning calorimetry  

Microsoft Academic Search

Electron spin resonance spectroscopy (ESR), based upon the spin trapping technique, was applied at 60 °C for evaluating the oxidative stability of 11 vegetable oil samples, including sunflower oil, rapeseed oil and their mixtures. The ESR results were compared with the oxidative stability values provided by the Rancimat method and differential scanning calorimetry (DSC) at 100 °C. High linear correlations were found

Joaqu??n Velasco; Mogens L. Andersen; Leif H. Skibsted

2004-01-01

172

Evolved gas analysis (EGA) in TG and DSC with single photon ionisation mass spectrometry (SPI-MS): molecular organic signatures from pyrolysis of soft and hard wood, coal, crude oil and ABS polymer  

Microsoft Academic Search

A combined thermogravimetry\\/differential scanning calorimetry device (TG\\/DSC) was coupled to single photon ionisation mass spectrometry (SPI-MS) for evolved gas analysis (EGA). Single photon ionisation (SPI) was performed with a new type of VUV light source, the so called electron beam pumped rare gas excimer lamp (EBEL). SPI does not fragment molecules upon the ionisation process. Thus the molecular mass signature

T. Streibel; R. Geißler; M. Saraji-Bozorgzad; M. Sklorz; E. Kaisersberger; T. Denner; R. Zimmermann

2009-01-01

173

Ionic conductivity, DSC and self diffusion coefficients of lithium, anion, polymer, and solvent of polymer gel electrolytes: the structure of the gels and the diffusion mechanism of the ions  

Microsoft Academic Search

The polymer gel electrolytes studied in this paper are composed of two kinds of organic solvents (?-butyrolactone (GBL) or propylene carbonate (PC)), two kinds of lithium salts (LiBF4 or lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, LiN(SO2CF3)2)) and chemically cross-linked poly(ethyleneoxide) (PEO). The ionic conductivity and the thermal properties were measured by the AC impedance method and differential scanning calorimetry (DSC), respectively. The individual

Yuichi Aihara; Shigemasa Arai; Kikuko Hayamizu

2000-01-01

174

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

175

Dehydration\\/recrystallization mechanisms, energetics, and kinetics of hydrated calcium silicate minerals: an in situ TGA\\/DSC and synchrotron radiation SAXS\\/WAXS study  

Microsoft Academic Search

The dehydration and recrystallization of the natural hydrated calcium silicates xonotlite [Ca6Si6O17(OH)2], 11Å anomalous tobermorite [Ca5Si6O16(OH)2·4H2O], and hillebrandite [Ca2SiO3(OH)2] were studied in situ by dynamic heating (5°C min?1) differential scanning calorimetry\\/thermogravimetric analysis (TGA\\/DSC) and synchrotron small- and wide-angle X-ray scattering (SAXS\\/WAXS). All have structures based on silicate chains with a repeat unit of three tetrahedra (‘dreierketten’). Room-T infrared data for

S Shaw; C. M. B Henderson; B. U Komanschek

2000-01-01

176

Crystallization Behavior of Aromatic Copolyesters: Time-Resolved X-Ray Scattering and DSC Studies  

NASA Astrophysics Data System (ADS)

Poly(ethylene isophthalate-co-terephthalate)s (PEIT) were synthesized by conventional melt copolymerization process with varying composition: copolyesters were obtained with reasonably high molecular weights. For PEIT copolymers were there measured intrinsic viscosity, crystallization temperature, and crystal melting temperature. And, equilibrium crystal melting temperature was estimated. The crystal melting temperature decreased linearly with increasing the content of ethylene isophthalate (EIT) unit, indicating that random copolyesters were made in the copolymerization. PEIT copolyester containing EIT unit of 0-20 mol% and >90 mol% were crystallizable, whereas copolyester containing 20 mol% < EIT < 90 mol% were not crystallizable. For copolyesters containing <20 mol% EIT unit, crystallization behavior was investigated isothermally and non-isothermally by time-resolved X-ray scattering and differential scanning calorimetry (DSC). Overall, the non-crystallizable EIT unit affected significantly the crystallization behavior of and the morphological structure of poly(ethylene terephthalate) homopolymer. Higher content of EIT unit in the copolyester caused lower crystallization rate. Further, the EIT unit influnced the lamellar crystal structure, including lamellar crystal thickness and inter-lamellar space. All results will be discussed with considering the role of non-crystallizable EIT unit in the copolyester. [This study was supported by POSCO and MOST].

Ree, Moonhor; Lee, Byeongdu; Shin, Tae Joo; Wang, Xiaodong; Youn, Hwa Shik

2000-03-01

177

Melting by temperature-modulated calorimetry  

SciTech Connect

Well-crystallized macromolecules melt irreversibly due to the need of molecular nucleation, while small molecules melt reversibly as long as crystal nuclei are present to assist crystallization. Furthermore, imperfect crystals of low-molar-mass polymers may have a sufficiently small region of metastability between crystallization and melting to show a reversing heat-flow component due to melting of poor crystals followed by crystallization of imperfect crystals which have insufficient time to perfect before the modulation switches to heating and melts the imperfect crystals. Many metals, in turn. melt sharply and reversibly as long as nuclei remain after melting for subsequent crystallization during the cooling cycle. Their analysis is complicated, however, due to thermal conductivity limitations of the calorimeters. Polymers of sufficiently high molar mass, finally, show a small amount of reversible. local melting that may be linked to partial melting of individual molecules. Experiments by temperature-modulated calorimetry and model calculations are presented. The samples measured included poly(ethylene terephthalate)s, poly(ethylene oxide)s, and indium. Two unsolved problems that arose from this research involve the origin of a high, seemingly stable, reversible heat capacity of polymers in the melting region, and a smoothing of melting and crystallization into a close-to-elliptical Lissajous figure in a heat-flow versus sample-temperature plot.

Wunderlich, B.; Okazaki, Iwao; Ishikiriyama, Kazuhiko; Boller, A. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry]|[Oak Ridge National Lab., TN (United States)

1997-09-01

178

A differential scanning calorimetry study of retrieved orthopedic implants made of ultrahigh molecular weight polyethylene.  

PubMed

Differential scanning calorimetry (DSC) was used to examine thermal and thermooxidative properties of ultrahigh molecular weight polyethylene (UHMW-PE) of five acetabular components of failed orthopedic implants retrieved at revision of total hip arthoplasty. The results were compared with controls (unimplanted acetabular cups, a 20-year-old slab of UHMW-PE, and raw material). Profiles of exothermic peaks indicated increased levels of oxidation in all retrieved cups. In three retrieved cups, DSC revealed an additional peak of endotherm that was not seen in control samples. The additional endotherm peaks were not artifacts due to oxidation during scanning, heat buildup during cutting of the samples, or the sterilization method after retrieval. The additional peak was associated with the bulk of the polymer that was extracted with hexane. It varied in relative area, depending on its original location of the sample in a cup, implicating local variability in the extent of changes in material property. The distribution of the changes suggests that, during implantation, tissue exposure and friction affected the level of oxidation and degree of crystallinity in the UHMW-PE to a greater degree than did loading alone. Overall results showed that DSC may be a useful tool in evaluating changes in the properties of UHMW-PE orthopedic components in vivo. PMID:8736025

Witkiewicz, H; Deng, M; Vidovszky, T; Bolander, M E; Rock, M G; Morrey, B F; Shalaby, S W

1996-01-01

179

Interaction between cytochrome caa3 and F1F0-ATP synthase of alkaliphilic Bacillus pseudofirmus OF4 is demonstrated by saturation transfer electron paramagnetic resonance and differential scanning calorimetry assays.  

PubMed

Interaction between the cytochrome caa3 respiratory chain complex and F1F0-ATP synthase from extremely alkaliphilic Bacillus pseudofirmus OF4 has been hypothesized to be required for robust ATP synthesis by this alkaliphile under conditions of very low protonmotive force. Here, such an interaction was probed by differential scanning calorimetry (DSC) and by saturation transfer electron paramagnetic resonance (STEPR). When the two purified complexes were embedded in phospholipid vesicles individually [(caa3)PL, (F1F0)PL)] or in combination [(caa3 + F1F0)PL] and subjected to DSC analysis, they underwent exothermic thermodenaturation with transition temperatures at 69, 57, and 46/75 degrees C, respectively. The enthalpy change, deltaH (-8.8 kcal/mmol), of protein-phospholipid vesicles containing both cytochrome caa3 and F1F0 was smaller than that (-12.4 kcal/mmol) of a mixture of protein-phospholipid vesicles formed from each individual electron transfer complex [(caa3)PL + (F1F0)PL]. The rotational correlation time of spin-labeled caa3 (65 micros) in STEPR studies increased significantly when the complex was mixed with F1F0 prior to being embedded in phospholipid vesicles (270 micros). When the complexes were reconstituted separately and then mixed together, or either mitochondrial cytochrome bc1 or F1F0 was substituted for the alkaliphile F1F0, the correlation time was unchanged (65-70 micros). Varying the ratio of the two alkaliphile complexes in both the DSC and STEPR experiments indicated that the optimal stoichiometry is 1:1. These results demonstrate a physical interaction between the cytochrome caa3 and F1F0-ATP synthase from B. pseudofirmus OF4 in a reconstituted system. They support the suggestion that such an interaction between these complexes may contribute to sequestered proton transfers during alkaliphile oxidative phosphorylation at high pH. PMID:17198401

Liu, Xiaoying; Gong, Xing; Hicks, David B; Krulwich, Terry A; Yu, Linda; Yu, Chang-An

2007-01-01

180

An investigation of the phase transitions in bornite (Cu 5FeS4) using neutron diffraction and differential scanning calorimetry  

Microsoft Academic Search

Bornite (Cu5FeS4) exists in three polymorphic forms related by superstructuring, with structural transitions at 200 and 265 8C. The phase transitions and structural behavior in two natural bornite samples were investigated as a function of temperature using differ- ential scanning calorimetry (DSC) to characterize the thermal anomalies associated with each transition and in-situ high-resolution neutron powder diffraction to determine the

BENJAMIN A. GRGURIC; ANDREW PUTNIS; RICHARD J. HARRISON

181

Influence of functionalization on interaction and drug release from ?,?-polyaspartylhydrazide derivatives to a biomembrane model: evaluation by differential scanning calorimetry technique  

Microsoft Academic Search

A comparative study on the ability of various polymers to interact with a biomembrane model was carried out by differential scanning calorimetry (DSC). The investigated samples were a water soluble polymer, the ?,?-polyaspartylhydrazide (PAHy) and its derivatives containing polyethylene glycol (PEG2000) (sample PAHy–PEG2000), or hexadecylamine (C16) (sample PAHy–C16) or both compounds (sample PAHy–PEG2000–C16). Some samples are able to arrange themselves

Francesco Castelli; Chiara Messina; Elisa Martinetti; Mariano Licciardi; Emanuela Fabiola Craparo; Giovanna Pitarresi

2004-01-01

182

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

183

Experimental Considerations for Temperature Modulated DSC at Low Temperature  

Microsoft Academic Search

Temperature modulated DSC (TMDSC) at low temperatures requires attention to the selection of experimental parameters that\\u000a are within the capability of the instrumentation as well as special care in calibration of heat capacity measurement when\\u000a high precision is required. Data are presented to facilitate selection of appropriate modulation periods and amplitudes at\\u000a low temperature when using a mechanical cooling accessory.

S. A. Knopp; S. L. Nail

2000-01-01

184

Can one measure precise heat capacities with DSC or TMDSC?  

Microsoft Academic Search

Summary  During a prior study of gel-spun fibers of ultrahigh-molar-mass polyethylene, a substantial error was observed on calculating\\u000a the heat capacity with a deformed pan, caused by the lateral expansion of the fibers on shrinking during fusion. In this paper,\\u000a the causes of this and other effects that limit the precision of heat capacity measurements by DSC and TMDSC are explored.

J. Pak; W. Qiu; M. Pyda; E. Nowak-Pyda; B. Wunderlich

2005-01-01

185

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

186

DSC solution forow in a staggered double lid driven cavity  

Microsoft Academic Search

SUMMARY A benchmark quality solution is presented forow in a staggered double lid driven cavity obtained by using the wavelet-based discrete singular convolution (DSC). The proposed wavelet based algo- rithm combines local methods' ?exibility and global methods' accuracy, and hence, is a promising ap- proach for achieving the high accuracy solution of the Navier-Stokes equations. Block structured grids with pseudo-overlapping

Y. C. Zhou; B. S. V. Patnaik; D. C. Wan; G. W. Wei

187

Dsc Orthologs Are Required for Hypoxia Adaptation, Triazole Drug Responses, and Fungal Virulence in Aspergillus fumigatus  

PubMed Central

Hypoxia is an environmental stress encountered by Aspergillus fumigatus during invasive pulmonary aspergillosis (IPA). The ability of this mold to adapt to hypoxia is important for fungal virulence and genetically regulated in part by the sterol regulatory element binding protein (SREBP) SrbA. SrbA is required for fungal growth in the murine lung and to ultimately cause lethal disease in murine models of IPA. Here we identified and partially characterized four genes (dscA, dscB, dscC, and dscD, here referred to as dscA-D) with previously unknown functions in A. fumigatus that are orthologs of the Schizosaccharomyces pombe genes dsc1, dsc2, dsc3, and dsc4 (dsc1-4), which encode a Golgi E3 ligase complex critical for SREBP activation by proteolytic cleavage. A. fumigatus null dscA-D mutants displayed remarkable defects in hypoxic growth and increased susceptibility to triazole antifungal drugs. Consistent with the confirmed role of these genes in S. pombe, both ?dscA and ?dscC resulted in reduced cleavage of the SrbA precursor protein in A. fumigatus. Inoculation of corticosteroid immunosuppressed mice with ?dscA and ?dscC strains revealed that these genes are critical for A. fumigatus virulence. Reintroduction of SrbA amino acids 1 to 425, encompassing the N terminus DNA binding domain, into the ?dscA strain was able to partially restore virulence, further supporting a mechanistic link between DscA and SrbA function. Thus, we have shown for the first time the importance of a previously uncharacterized group of genes in A. fumigatus that mediate hypoxia adaptation, fungal virulence, and triazole drug susceptibility and that are likely linked to regulation of SrbA function.

Willger, Sven D.; Cornish, E. Jean; Chung, Dawoon; Fleming, Brittany A.; Lehmann, Margaret M.; Puttikamonkul, Srisombat

2012-01-01

188

Evaluation of the physical stability of freeze-dried sucrose-containing formulations by differential scanning calorimetry.  

PubMed

Freeze-dried samples of sucrose with buffer salts, amino acids, or dextran have been analyzed with differential scanning calorimetry (DSC) to evaluate the use of DSC thermograms in predicting the physical storage stability. The glass transition temperature, Tg, of the amorphous cake, crystallization, and melting of sucrose are observed with DSC. Tg appeared to be an important characteristic of the physical stability of the amorphous freeze-dried cake. A storage temperature above Tg results in collapse or shrinkage of the cake, which for a sucrose-based formulation, may be accompanied by crystallization of the sucrose. The Tg of the amorphous sucrose is influenced by other components present in the cake. Dextran-40 raised Tg, while the addition of glycine to the formulation lowered Tg. The residual moisture content strongly influences Tg, since water acts as a plasticizer of the system; the higher the moisture content, the lower the Tg and the less physically stable the freeze-dried cake. Crystallization of amorphous sucrose is shown to be inhibited by high molecular weight components or ionic compounds. DSC analysis of freeze-dried cakes proved to be a powerful tool in formulation studies. PMID:1589394

te Booy, M P; de Ruiter, R A; de Meere, A L

1992-01-01

189

Quantitative determination of the specific heat and the glass transition of moist samples by temperature modulated differential scanning calorimetry.  

PubMed

In differential scanning calorimetry (DSC), remnant moisture loss in samples often overlaps and distorts other thermal events, e.g. glass transitions. To separate such overlapping processes, temperature modulated DSC (TMDSC) has been widely used. In this contribution we discuss the quantitative determination of the heat capacity of a moist sample from TMDSC measurements. The sample was a spray-dried pharmaceutical compound run in different pans (hermetically-sealed pan, pierced lid pan [50 microm] and open pan). The apparent heat capacity was corrected for the remaining amount of moisture. Using this procedure we could clearly identify the glass transition of the dry and the moist sample. We found that a moisture content of about 6.2% shifts the glass transition by about 50 degrees C. PMID:11292553

Schubnell, M; Schawe, J E

2001-04-17

190

Apparent Thermal Properties of Phase-Change Materials: An Analysis Using Differential Scanning Calorimetry and Impulse Method  

NASA Astrophysics Data System (ADS)

Thermal properties of newly developed plaster based on hydrated lime, metakaolin, and paraffinic wax enclosed in polymer micro-capsules are studied in the article. At first, differential scanning calorimetry (DSC) is applied on Micronal PCM capsules for determination of the temperature interval of thawing and solidification. Then, the initial temperature of the phase change and specific heat capacity of the plaster are measured by DSC. The thermal conductivity and thermal diffusivity are determined by an impulse method. For comparative reasons, the properties of lime-based plaster without PCM are studied as well. The obtained results demonstrate the enhanced heat storage capacity of the studied material that can be used for application in lightweight building envelope systems.

Pavlík, Zbyšek; Trník, Anton; Ondruška, Ján; Keppert, Martin; Pavlíková, Milena; Volfová, Petra; Kaulich, Viktor; ?erný, Robert

2013-05-01

191

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

Code of Federal Regulations, 2012 CFR

... 2012-10-01 2012-10-01 false Frequencies for digital selective calling (DSC). 80.359 Section 80.359...Frequencies Radiotelegraphy § 80.359 Frequencies for digital selective calling (DSC). (a) General purpose...

2012-10-01

192

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

Code of Federal Regulations, 2012 CFR

...Telecommunication 5 2012-10-01 2012-10-01 false Digital selective calling (DSC) operating procedures. 80.103...Procedures Operating Procedures-General § 80.103 Digital selective calling (DSC) operating procedures....

2012-10-01

193

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

194

Experimental study of phase transformation and specific heat of ternary zirconia-based oxides using differential scanning calorimetry  

Microsoft Academic Search

Phase transformation and specific heat of five ternary zirconia-based oxides were studied using differential scanning calorimetry (DSC). The ternary oxides were fabricated by doping 7YSZ (3.945mol.% Y2O3–ZrO2) with pentavalent oxides Ta2O5 and Nb2O5, trivalent oxides Sc2O3 and Yb2O3, and tetravalent oxide CeO2. The addition of pentavalent oxides to 7YSZ increased the formation of monoclinic phase upon cooling in comparison to

Andrey Zakurdaev; Xiao Huang

2009-01-01

195

Liquid Argon Calorimetry for ATLAS  

NASA Astrophysics Data System (ADS)

This summer, the largest collaborative physics project since the Manhattan project will go online. One of four experiments for the Large Hadron Collider at CERN in Geneva, ATLAS, employs over 2000 people. Canadians have helped design, construct, and calibrate the liquid argon calorimeters for ATLAS to capture the products of the high energy collisions produced by the LHC. From an undergraduate's perspective, explore how these calorimeters are made to handle their harsh requirement. From nearly a billion proton-proton collisions a second, physicists hope to discover the Higgs boson and other new fundamental particles.

Robinson, Alan

2008-05-01

196

Determinationof oxidation induction time and temperature bY DSC  

Microsoft Academic Search

Results obtained from three round robin tests, performed\\u000a in 1998, 2000 and 2004, are summarized and presented. Oxidation Induction\\u000a Time (OITtime) and Oxidation Induction Temperature\\u000a (OITtemp) on six different grades of polyethylene were\\u000a measured by DSC. The measured data were collected by Empa and evaluated using\\u000a a robust statistical method concerning repeatability and reproducibility standard\\u000a deviation.\\u000a \\u000a The\\u000a results of the

M. Schmid; A. Ritter; S. Affolter

2006-01-01

197

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.

198

Tetramethyllead: heat of formation by rotating-bomb calorimetry  

Microsoft Academic Search

Combustion calorimetry of tetramethyllead was done by a rotating-bomb method. The experiments gave for the reaction (CHâ)âPb(liq) + 2HNOâ(in 40 HâO) + 7.5 Oâ(g) = Pb(NOâ)â(c) + 7 HâO(liq) + 4 COâ(g) the value ..delta..H°âââ.ââ = - 886.8 +- 0.3 kcal. The heat of vaporization was calculated from the results of vapor pressure measurements. Derived values for the heat of

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

1959-01-01

199

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

200

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

201

An evaluation tool for FKBP12-dependent and -independent mTOR inhibitors using a combination of FKBP-mTOR fusion protein, DSC and NMR  

PubMed Central

Mammalian target of rapamycin (mTOR), a large multidomain protein kinase, regulates cell growth and metabolism in response to environmental signals. The FKBP rapamycin-binding (FRB) domain of mTOR is a validated therapeutic target for the development of immunosuppressant and anticancer drugs but is labile and insoluble. Here we designed a fusion protein between FKBP12 and the FRB domain of mTOR. The fusion protein was successfully expressed in Escherichia coli as a soluble form, and was purified by a simple two-step chromatographic procedure. The fusion protein exhibited increased solubility and stability compared with the isolated FRB domain, and facilitated the analysis of rapamycin and FK506 binding using differential scanning calorimetry (DSC) and solution nuclear magnetic resonance (NMR). DSC enabled the rapid observation of protein–drug interactions at the domain level, while NMR gave insights into the protein–drug interactions at the residue level. The use of the FKBP12–FRB fusion protein combined with DSC and NMR provides a useful tool for the efficient screening of FKBP12-dependent as well as -independent inhibitors of the mTOR FRB domain.

Sekiguchi, Mitsuhiro; Kobashigawa, Yoshihiro; Kawasaki, Masashi; Yokochi, Masashi; Kiso, Tetsuo; Suzumura, Ken-ichi; Mori, Keitaro; Teramura, Toshio; Inagaki, Fuyuhiko

2011-01-01

202

Isothermal Titration Calorimetry for Measuring Macromolecule-Ligand Affinity  

PubMed Central

Isothermal titration calorimetry (ITC) is a useful tool for understanding the complete thermodynamic picture of a binding reaction. In biological sciences, macromolecular interactions are essential in understanding the machinery of the cell. Experimental conditions, such as buffer and temperature, can be tailored to the particular binding system being studied. However, careful planning is needed since certain ligand and macromolecule concentration ranges are necessary to obtain useful data. Concentrations of the macromolecule and ligand need to be accurately determined for reliable results. Care also needs to be taken when preparing the samples as impurities can significantly affect the experiment. When ITC experiments, along with controls, are performed properly, useful binding information, such as the stoichiometry, affinity and enthalpy, are obtained. By running additional experiments under different buffer or temperature conditions, more detailed information can be obtained about the system. A protocol for the basic setup of an ITC experiment is given.

Duff, Jr., Michael R.; Grubbs, Jordan; Howell, Elizabeth E.

2011-01-01

203

Improving the dispersity of detonation nanodiamond: differential scanning calorimetry as a new method of controlling the aggregation state of nanodiamond powders  

NASA Astrophysics Data System (ADS)

Detonation nanodiamond (ND) is a suitable source material to produce unique samples consisting of almost uniform diamond nanocrystals (d = 3-5 nm). Such samples exist in the form of long stable aqueous dispersions with narrow size distribution of diamond particles. The material is finding ever increasing application in biomedicine. The major problem in producing monodispersed diamond colloids lies in the necessity of deagglomeration of detonation soot and/or removing of clusters formed by already isolated core particles in dry powders. To do this one must have an effective method to monitor the aggregation state or dispersity of powders and gels prior to the preparation of aqueous dispersions. In the absence of dispersity control at various stages of preparation the reproducibility of properties of existing ND materials is poor. In this paper we introduce differential scanning calorimetry (DSC) as a new tool capable to distinguish the state of aggregation in dry and wetted ND materials and to follow changes in this state under different types of treatment. Samples with identical X-ray diffraction patterns (XRD) and high resolution transmission electron microscopy (HRTEM) images gave visibly different DSC traces. Strong correlation was found between dynamic light scattering (DLS) data for colloids and DSC parameters for gels and powders of the same material. Based on DSC data we improved dispersity of existing ND materials and isolated samples with the best possible DSC parameters. These were true monodispersed easily dispersible fractions of ND particles with diameters of ca. 3 nm.

Korobov, Mikhail V.; Volkov, Dmitry S.; Avramenko, Natalya V.; Belyaeva, Lubov'a.; Semenyuk, Pavel I.; Proskurnin, Mikhail A.

2013-01-01

204

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

205

Polymorphism of [Zn(NH 3) 4](ClO 4) 2 and [Zn(NH 3) 4](BF 4) 2 studied by differential scanning calorimetry and far infrared spectroscopy  

Microsoft Academic Search

The phase transitions in [Zn(NH3)4](ClO4)2 and [Zn(NH3)4](BF4)2 were determined by differential scanning calorimetry (DSC) and the discovered phases were identified by far infrared spectroscopy (FT-FIR). Four solid phases were found for both the compounds. The characteristic changes in the FT-FIR absorption spectra were observed in the particular phases of both the compounds at temperatures predicted by the DSC. Additionally, the

A. Migda?-Mikuli; E. Mikuli; ?. Hetma?czyk; E. ?ciesi?ska; J. ?ciesi?ski; S. Wróbel; N. Górska

2001-01-01

206

CDF (Collider Detector at Fermilab) calorimetry  

SciTech Connect

The Collider Detector at Fermilab (CDF) is a large detector built to study 2 TeV anti p p collisions at the Fermilab Tevatron. The calorimetry, which has polar angle coverage from 2 to 178, and complete azimuthal coverage within this region, forms the subject of this paper. It consists of both electromagnetic shower counters (EM calorimeters) and hadron calorimeters, and is segmented into about 5000 ''towers'' or solid angle elements.

Jensen, H.B.

1987-03-01

207

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

2010-11-12

208

Identification of the thermal transitions in potato starch at a low water content as studied by preparative DSC  

Microsoft Academic Search

The aim of this work was to identify the transitions in the complex DSC profiles of potato starch at a low water content. Preparative DSC involves the thermal processing of samples in stainless steel DSC pans in a way that allows their subsequent structural characterization. The low temperature (LT), dual melting (M1–M2), and high temperature (HT) endotherms observed in DSC

Peter A. M. Steeneken; Albert J. J. Woortman

2009-01-01

209

Characterization of Starch Pharmaceuticals by DSC Coupled to a Photovisual System  

Microsoft Academic Search

The present work proposes evaluation of the gelatinization processes of starch by means of DSC coupled with a photovisual\\u000a system. The use of DSC, TG and DTA for a fast and efficient evaluation of the starch is suggested. The DSC curves of starch\\u000a gels with water contents of 20, 30, 40 and 50% (mass\\/v) exhibited different phase transitions, corresponding to

F. Santos de Souza; A. P. Gomes Barreto; R. O. Macêdo

2001-01-01

210

Characterization of supercooled liquid Ge2Sb2Te5 and its crystallization by ultrafast-heating calorimetry  

NASA Astrophysics Data System (ADS)

Differential scanning calorimetry (DSC) is widely used to study the stability of amorphous solids, characterizing the kinetics of crystallization close to the glass-transition temperature Tg. We apply ultrafast DSC to the phase-change material Ge2Sb2Te5 (GST) and show that if the range of heating rates is extended to more than 104?K?s-1, the analysis can cover a wider temperature range, up to the point where the crystal growth rate approaches its maximum. The growth rates that can be characterized are some four orders of magnitude higher than in conventional DSC, reaching values relevant for the application of GST as a data-storage medium. The kinetic coefficient for crystal growth has a strongly non-Arrhenius temperature dependence, revealing that supercooled liquid GST has a high fragility. Near Tg there is evidence for decoupling of the crystal-growth kinetics from viscous flow, matching the behaviour for a fragile liquid suggested by studies on oxide and organic systems.

Orava, J.; Greer, A. L.; Gholipour, B.; Hewak, D. W.; Smith, C. E.

2012-04-01

211

Study of Polymer Glasses by Modulated Differential Scanning Calorimetry in the Undergraduate Physical Chemistry Laboratory  

Microsoft Academic Search

Recent technological advances in thermal analysis present educational opportunities. In particular, modulated differential scanning calorimetry (MDSC) can be used to contrast reversing and nonreversing processes in practical laboratory experiments. The introduction of these concepts elucidates the relationship between experimental timescales and reversibility. The latter is a key concept of undergraduate thermodynamics theory that deserves reinforcement. In this paper, the theory

J. C. W. Folmer; Stefan Franzen

2003-01-01

212

Pressure-Differential Scanning Calorimetry of Coals, Organic Compounds, and Polymers.  

National Technical Information Service (NTIS)

Pressure differential scanning calorimetry (PDSC) has been found to be a useful technique for the rapid measurement of heat of combustion of coals. A typical experiment involves heating a 1 to 1.5 mg sample at a linear rate of 20 exp 0 C/min over the rang...

S. A. Benson K. S. Groon H. H. Schobert

1983-01-01

213

Lead tungstate (PbWO 4) scintillators for LHC EM calorimetry  

Microsoft Academic Search

This report describes the work carried out in order to analyse the properties of PbWO4 crystals as scintillators and to determine the perspectives of their use in calorimetry in Large Hadron Collider (LHC) experiments. The scintillation mechanism in PWO crystals is explained and the properties connected with their use as scintillators are analysed both for undoped and Nb doped crystals.

P. Lecoq; I. Dafinei; E. Auffray; M. Schneegans; M. V. Korzhik; O. V. Missevitch; V. B. Pavlenko; A. A. Fedorov; A. N. Annenkov; V. L. Kostylev; V. D. Ligun

1995-01-01

214

Calorimetry Exchange Program, Annual Data Report, 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.

1991-12-31

215

Determining enzyme kinetics via isothermal titration calorimetry.  

PubMed

Isothermal titration calorimetry (ITC) has emerged as a powerful tool for determining the thermodynamic properties of chemical or physical equilibria such as protein-protein, ligand-receptor, and protein-DNA binding interactions. The utility of ITC for determining kinetic information, however, has not been fully recognized. Methods for collecting and analyzing data on enzyme kinetics are discussed here. The step-by-step process of converting the raw heat output rate into the kinetic parameters of the Michaelis-Menten equation is explicitly stated. The hydrolysis of sucrose by invertase is used to demonstrate the capability of the instrument and method. PMID:23423886

Demarse, Neil A; Killian, Marie C; Hansen, Lee D; Quinn, Colette F

2013-01-01

216

Phase transformations undergone by Triton X-100 probed by differential scanning calorimetry and dielectric relaxation spectroscopy.  

PubMed

The phase transformations of the surfactant Triton X-100 were investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM), and dielectric relaxation spectroscopy (DRS). In particular, crystallization was induced at different cooling rates comprised between 13 and 0.5 K min(-1). Vitrification was detected by both DSC and DRS techniques with a glass transition temperature of ?212 K (measured on heating by DSC) allowing classifying Triton X-100 as a glass former. A fully amorphous material was obtained by cooling at a rate ?10 K min(-1), while crystallization was observed for lower cooling rates. The temperature of the onset of melt-crystallization was found to be dependent on the cooling scan rate, being higher the lower was the scan rate. In subsequent heating scans, the material undergoes cold-crystallization except if cooled previously at a rate ?1 K min(-1). None of the different thermal histories led to a 100% crystalline material because always the jump typical of the glass transformation in both heat flux (DSC) and real permittivity (DRS) is observed. It was also observed that the extent/morphology of the crystalline phase depends on the degree of undercooling, with higher spherulites developing for lower undercooling degree (24 K ? T(m) - T(cr) ? 44 K) in melt-crystallization and a grain-like morphology emerging for T(m) - T(cr) ? 57 K either in melt- or cold-crystallization. The isothermal cold- and melt-crystallizations were monitored near above the calorimetric glass transition temperature by POM (221 K) and real-time DRS (T(cr) = 219, 220, and 221 K) to evaluate the phase transformation from an amorphous to a semicrystalline material. By DRS, the ?-relaxation associated with the dynamic glass transition was followed, with the observation that it depletes upon both type of crystallizations with no significant changes either in shape or in location. Kinetic parameters were obtained from the time evolution of the normalized permittivity according to a modified Avrami model taking in account the induction time. The reason the isothermal crystallization occurs to a great extent in the vicinity of the glass transition was rationalized as the simultaneous effect of (i) a high dynamic fragile behavior and (ii) the occurrence of catastrophic nucleation/crystal growth probably enabled by a preordering tendency of the surfactant molecules. This is compatible with the estimated low Avrami exponent (1.12 ? n ? 1.6), suggesting that relative short length scale motions govern the crystal growth in Triton X-100 coherent with the observation of a grainy crystallization by POM. PMID:21928821

Merino, Esther G; Rodrigues, Carla; Viciosa, M Teresa; Melo, Carlos; Sotomayor, João; Dionísio, Madalena; Correia, Natália T

2011-10-11

217

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

218

Electronics for calorimetry: An overview of requirements  

SciTech Connect

Calorimetry in large detectors at LHC poses some requirements on readout electronics which are quite different than for central tracking and muon tracking. The main distinction is, (a) in the large dynamic range of the energies to be measured; and (b) uniformity of response and accuracy of calibration over the whole detector. As in all other functions of the detector, low noise is essential. High luminosity results in pileup effects, which are present in every measurement, and in high radiation for front and forward parts of the calorimeter. Power dissipation and cooling is a concern as in any other detector component, in some respects only more so, since all the elements of the signal processing chain require more power due to the large dynamic range, speed of response, high precision and low noise required. The key requirements on the calorimetry readout electronics are briefly discussed here, with an emphasis on the dynamic range. While there are quite significant differences in the principles and technology among the crystals, tiles with fibers and liquid ionization, the signal is finally reduced to a charge measurement from a capacitive source in all three cases, and the signal processing chain becomes remarkably identical.

Radeka, V.

1995-10-01

219

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

220

DSC Study on Cooperative Relaxation in 1,2-propanediol  

NASA Astrophysics Data System (ADS)

Cooling rate dependence of the cooperative relaxation in 1,2-propanediol was investigated in terms of the nonlinear Adam-Gibbs (AG) enthalpy relaxation theory using differential scanning calorimetry. The AG parameters were obtained using a curve-fitting method. The results indicated that the model parameters show strong dependence on the cooling rates. Those obtained at higher cooling rates are in good agreement with the published data. The fitting results were used to estimate the microscopic parameters of the cooperative rearranging region (CRR), in particular the size of the CRR (z*) and the configurational state available to it (W*). It was found that the W* recommended for polymers led to physically meaningless z* for 1,2-propanediol. Johari's method, which was based on the AG theory, yielded around 3 molecules in the CRR, but the W* was anomalistically higher than those of polymers. It is difficult to reconcile the Adam-Gibbs' z* with the results obtained using Donth's formula. An argument is presented that a new physical meaning should be given to conventional Adam-Gibbs' z* for molecular H-bond liquids.

Gao, Cai; Wang, Tie-jun; Liu, Xiang-nong; Zhou, Guo-yan; Hua, Tse-chao

2007-06-01

221

Epigenetic silencing of DSC3 is a common event in human breast cancer  

PubMed Central

Introduction Desmocollin 3 (DSC3) is a member of the cadherin superfamily of calcium-dependent cell adhesion molecules and a principle component of desmosomes. Desmosomal proteins such as DSC3 are integral to the maintenance of tissue architecture and the loss of these components leads to a lack of adhesion and a gain of cellular mobility. DSC3 expression is down-regulated in breast cancer cell lines and primary breast tumors; however, the loss of DSC3 is not due to gene deletion or gross rearrangement of the gene. In this study, we examined the prevalence of epigenetic silencing of DSC3 gene expression in primary breast tumor specimens. Methods We used bisulfite genomic sequencing to analyze the methylation state of the DSC3 promoter region from 32 primary breast tumor specimens. We also used a quantitative real-time RT-PCR approach, and analyzed all breast tumor specimens for DSC3 expression. Finally, in addition to bisulfite sequencing and RT-PCR, we used an in vivo nuclease accessibility assay to determine the chromatin architecture of the CpG island region from DSC3-negative breast cancer cells lines. Results DSC3 expression was downregulated in 23 of 32 (72%) breast cancer specimens comprising: 22 invasive ductal carcinomas, 7 invasive lobular breast carcinomas, 2 invasive ductal carcinomas that metastasized to the lymph node, and a mucoid ductal carcinoma. Of the 23 specimens showing a loss of DSC3 expression, 13 (56%) were associated with cytosine hypermethylation of the promoter region. Furthermore, DSC3 expression is limited to cells of epithelial origin and its expression of mRNA and protein is lost in a high proportion of breast tumor cell lines (79%). Lastly, DNA hypermethylation of the DSC3 promoter is highly correlated with a closed chromatin structure. Conclusion These results indicate that the loss of DSC3 expression is a common event in primary breast tumor specimens, and that DSC3 gene silencing in breast tumors is frequently linked to aberrant cytosine methylation and concomitant changes in chromatin structure.

Oshiro, Marc M; Kim, Christina J; Wozniak, Ryan J; Junk, Damian J; Munoz-Rodriguez, Jose L; Burr, Jeanne A; Fitzgerald, Matthew; Pawar, Sangita C; Cress, Anne E; Domann, Frederick E; Futscher, Bernard W

2005-01-01

222

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

223

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

224

Calorimetry of the arc welding process  

SciTech Connect

Minimizing the total heat input in arc welding is not usually a critical consideration when the size of the fusion zone and the weldment are very large. At SNLA, however, most welding can usually be described as microwelding. The depth of penetration is typically only 0.8 mm and hermeticity rather than mechanical strength is the primary joining requirement. For these type welds, minimizing heat input becomes a major process requirement since distortion of small components and damage to heat sensitive parts may result from large increases in the bulk temperature. In conclusion, we have found calorimetry to be a useful technique to determine the effect of arc welding process variables on heat input and melting efficiency and also to better select the required welding process for our weld geometries.

Fuerschbach, P.W.; Knorovsky, G.A.

1986-01-01

225

Higher throughput calorimetry: opportunities, approaches and challenges.  

PubMed

Higher throughput thermodynamic measurements can provide value in structure-based drug discovery during fragment screening, hit validation, and lead optimization. Enthalpy can be used to detect and characterize ligand binding, and changes that affect the interaction of protein and ligand can sometimes be detected more readily from changes in the enthalpy of binding than from the corresponding free-energy changes or from protein-ligand structures. Newer, higher throughput calorimeters are being incorporated into the drug discovery process. Improvements in titration calorimeters come from extensions of a mature technology and face limitations in scaling. Conversely, array calorimetry, an emerging technology, shows promise for substantial improvements in throughput and material utilization, but improved sensitivity is needed. PMID:20888754

Torres, Francisco E; Recht, Michael I; Coyle, Joseph E; Bruce, Richard H; Williams, Glyn

2010-10-01

226

Glass Transition Behavior of Spray Dried Orange Juice Powder Measured by Differential Scanning Calorimetry (DSC) and Thermal Mechanical Compression Test (TMCT)  

Microsoft Academic Search

Spray drying behavior of orange juice concentrate with various levels of maltodextrin (DE 6) was studied. Five combinations of orange juice concentrate and maltodextrin (25:75, 30:70, 35:65, 40:60, and 50:50) were spray dried at 160 and 65°C inlet and outlet temperatures, respectively. The product recovered with 50% maltodextrin concentration was sticky and only 20% powder was recovered. The recovery of

Ashok K. Shrestha; Tharalinee Ua-arak; Benu P. Adhikari; Tony Howes; Bhesh R. Bhandari

2007-01-01

227

Titration calorimetry standards and the precision of isothermal titration calorimetry data.  

PubMed

Current Isothermal Titration Calorimetry (ITC) data in the literature have relatively high errors in the measured enthalpies of protein-ligand binding reactions. There is a need for universal validation standards for titration calorimeters. Several inorganic salt co-precipitation and buffer protonation reactions have been suggested as possible enthalpy standards. The performances of several commercial calorimeters, including the VP-ITC, ITC200, and Nano ITC-III, were validated using these suggested standard reactions. PMID:19582227

Baranauskiene, Lina; Petrikaite, Vilma; Matuliene, Jurgita; Matulis, Daumantas

2009-06-18

228

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

229

Isothermal calorimetry for biological applications in food science and technology  

Microsoft Academic Search

All physical, chemical and biological processes produce heat and isothermal calorimetry is a general measurement technique to study all kinds of processes by the heat they produce. This paper gives several examples of studies of biological processes in the food area using isothermal calorimetry. It is for example shown how different unit operations influence respiration of vegetable tissue, how the

Lars Wadsö; Federico Gómez Galindo

2009-01-01

230

THE CALORIMETRY OF COMBUSTIONS AND RELATED REACTIONS: INORGANIC REACTIONS  

Microsoft Academic Search

A review is presented of calorimetric measurements of the heats of ; combustion and other reactions. The precision of the measurements is discussed, ; and possible sources of error in combustion calorimetry are considered. ; Measurement of the heats of formation of the oxides and other compounds is also ; discussed. Recent developments in calorimetry are described briefly, including ;

Holley; C. E. Jr

1962-01-01

231

Differential scanning calorimetry of plant cell walls  

SciTech Connect

High-sensitivity differential scanning calorimetry has been used to study the phase transition of cell wall preparations of the elongating and mature regions of soybean hypocotyls and of celery epidermis and collenchyma strands. A step-like transition believed to be glass transition was observed in walls isolated from the elongating region of soybean hypocotyls at 52.9C. Addition of 1 mM CaCl{sub 2} to the cell wall preparation increased the transition temperature to 60.8C and greatly reduced the transition magnitude. In walls from the mature region, the transition was small and occurred at a higher temperature (60.1C). Addition of calcium to the mature region cell wall had little effect on the transition. Based on the known interactions between calcium and pectin, the authors propose that calcium affects the glass transition by binding to the polygalacturonate backbone of wall pectin, resulting in a more rigid wall with a smaller transition at a higher temperature. The mature region either has more calcium in the wall or has more methyl-esterified pectin, making it less responsive to added calcium.

Lin, Liangshiou; Varner, J.E. (Washington Univ., St. Louis, MO (United States)); Yuen, H.K. (Monsanto Co., St. Louis, MO (United States))

1991-03-15

232

Hadron sampling calorimetry, a puzzle of physics  

NASA Astrophysics Data System (ADS)

The physics involved in hadron sampling calorimetry covers the wide energy range between high energy, medium energy, nuclear and atomic physics. All the processes contributing to energy depositions are discussed as well as illustrated by model calculations. The sampling fraction which determines the fraction of incident energy, which becomes visible in the detector layers, turns out to be strongly affected by the type of energy flow and the atomic number Z of the materials used. Normalized to mips, such fractions might range in the examples discussed between 0 and 2. Model calculations have been based on the HERMES scheme, which makes use of improved versions of the HET, the MORSE and the new developed DYMO code. The results allow to evaluate the degree of compensation and to predict e/h ratios. Such predictions agree quite well with the experimental results. In case of depleted uranium/scintillator sampling structures, compensation can be tuned by means of layer thicknesses. Finally, first results are presented for the investigation of fluctuations and correlations from model calculations evaluated event-by-event.

Brückmann, Hanno; Anders, Bernd; Behrens, Ulf

1988-01-01

233

Differential scanning calorimetry of plant cell walls.  

PubMed Central

High-sensitivity differential scanning calorimetry has been used to study the phase transition of cell wall preparations of the elongating and mature regions of soybean hypocotyls and of celery epidermis and collenchyma strands. A step-like transition believed to be glass transition was observed in walls isolated from the elongating region of soybean hypocotyls at 52.9 degrees C. Addition of 1 mM CaCl2 to the cell wall preparation increased the transition temperature to 60.8 degrees C and greatly reduced the transition magnitude. In walls from the mature region, the transition was small and occurred at a higher temperature (60.1 degrees C). Addition of calcium to the mature region cell wall had little effect on the transition. Based on the known interactions between calcium and pectin, we propose that calcium affects the glass transition by binding to the polygalacturonate backbone of wall pectin, resulting in a more rigid wall with a smaller transition at a higher temperature. The mature region either has more calcium in the wall or has more methyl-esterified pectin, making it less responsive to added calcium.

Lin, L S; Yuen, H K; Varner, J E

1991-01-01

234

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

235

DSC analysis of starch thermal properties related to functionality in low-moisture baked goods  

Microsoft Academic Search

We describe an application of DSC as an analytical ‘fingerprinting’ method that has been used to characterize the thermal properties of wheat starch in low-moisture, wheat-flour-based baked products, including cookies, crackers, and pretzels. This use of DSC has enabled us to relate starch thermal properties, on the one hand, to starch structure, and on the other hand, to starch functionality,

Louise Slade; H. Levine; Martha Wang; J. Ievolella

1996-01-01

236

Radiation effects on front-end electronics for noble liquid calorimetry  

Microsoft Academic Search

Front-end electronics for liquid ionization chamber calorimetry at hadron collider experiments may be exposed to substantial levels of ionizing radiation and neutron fluences in a cryogenic environment. Measurements of devices built with rad-hard technologies have shown that devices able to operate in these conditions exist. Si-JFET's and GaAs MESFET devices have been irradiated and tested at a stable cryogenic temperature

M. Citterio; S. Rescia; V. Radeka

1994-01-01

237

Advances in temperature derivative control and calorimetry  

SciTech Connect

Temperature stabilization by inertial feedback control has proven a powerful tool to create the ultrastable environment essential for high resolution calorimetry. A thermally insulated mass, connected to a base through Seebeck effect sensors (thermopiles) is used as a reference to control the base temperature. The thermopile signal is proportional to both the heat capacity of the reference mass and the derivative {dot {Theta}} of the base temperature {Theta}. Using vacuum insulation and bismuth telluride thermopiles, we designed and tested temperature derivative sensors (TDSs) with sensitivities up to 3300 VsK{sup {minus}1}. Standard industrial controllers with approximately {plus_minus}1 {mu}V input noise and stability, permit control of temperature derivatives to {plus_minus}3{times}10{sup {minus}10} Ks{sup {minus}1}. Single-cup thermoelectric calorimeters coupled to the TDS-controlled base permitted measurement of heat flow from samples in a power range from 3 {mu}W to 10 W with high accuracy ({plus_minus}100 ppm), resolution ({plus_minus}0.2 {mu}W), and reproducibility ({plus_minus}1 {mu}W). The design of two instruments is described in detail. Their performance is demonstrated on a variety of measurements, e.g., the determination of sample heat capacities with temperature ramp rates {dot {Theta}}={plus_minus}5{times}10{sup {minus}6} Ks{sup {minus}1}, the half-life of a 3 g tritium sample in a uranium getter bed, the decay heat of depleted uranium, and the heat evolution of epoxy resin. {copyright} {ital 1996 American Institute of Physics.}

Hemmerich, J.L.; Loos, J.; Miller, A.; Milverton, P. [JET Joint Undertaking, Abingdon, Oxon OX14 3EA (United Kingdom)

1996-11-01

238

Fluorine as an oxidant in combustion calorimetry  

SciTech Connect

Oxygen-bomb calorimetry has been used with some success over the years for the determination of enthalpies of formation ..delta../sub f/H/sub m//sup 0/ of inorganic compounds. This method, however, has a number of drawbacks, the most significant of which is the formation of complicated and ill-defined oxides as reaction products. Substitution of fluorine for oxygen, as the oxidizing gas, eliminates many of those problems. Because of the aggressive nature of fluorine, it can be used to study even the most refractory of materials, but its disadvantages are that it requires very careful handling and special apparatus. A portion of the present paper will discuss the precautions that must be taken, and the special calorimetric equipment that has been constructed. The main scope of the paper, however, is concerned with our recent results obtained for some high-purity chalcogenides. We have performed measurements on both the crystalline and vitreous forms of As/sub 2/Se/sub 3/. The enthalpies of formation have been deduced from the calorimetric enthalpies of fluorination. The following preliminary results at 298.15 K have been obtained and are compared in the paper with published values: ..delta../sub f/H/sub m//sup 0/(As/sub 2/Se/sub 3/, cr) = -(83.7+-4.5) kJ/center dot/mol/sup -1/ and ..delta../sub f/H/sub m//sup 0/(As/sub 2/Se/sub 3/, vit) = -(59.4+-4.3)kJ/center dot/mol/sup -1/. The enthalpy of transition is -(24.3+-3.9)kJ/center dot/mol/sup -1/, only about 60 per cent of the previous literature value. 27 refs., 2 figs., 6 tabs.

O'Hare, P.A.G.

1988-01-01

239

Energetics of anhydrite, barite, celestine, and anglesite: a high-temperature and differential scanning calorimetry study  

NASA Astrophysics Data System (ADS)

The thermochemistry of anhydrous sulfates (anglesite, anhydrite, arcanite, barite, celestine) was investigated by high-temperature oxide melt calorimetry and differential scanning calorimetry. Complete retention and uniform speciation of sulfur in the solvent was documented by (a) chemical analyses of the solvent (3Na 2O · 4MoO 3) with dissolved sulfates, (b) Fourier transform infrared spectroscopy confirming the absence of sulfur species in the gases above the solvent, and (c) consistency of experimental determination of the enthalpy of drop solution of SO 3 in the solvent. Thus, the principal conclusion of this study is that high-temperature oxide melt calorimetry with 3Na 2O · 4MoO 3 solvent is a valid technique for measurement of enthalpies of formation of anhydrous sulfates. Enthalpies of formation (in kJ/mol) from the elements (?H fo) were determined for synthetic anhydrite (CaSO 4) (-1433.8 ± 3.2), celestine (SrSO 4) (-1452.1 ± 3.3), anglesite (PbSO 4) (-909.9 ± 3.4), and two natural barite (BaSO 4) samples (-1464.2 ± 3.7, -1464.9 ± 3.7). The heat capacity of anhydrite, barite, and celestine was measured between 245 and 1100 K, with low- and high-temperature Netzsch (DSC-404) differential scanning calorimeters. The results for each sample were fitted to a Haas-Fisher polynomial of the form C p(245 K < T < 1100 K) = a + bT + cT -2 + dT -0.5 + eT 2. The coefficients of the equation are as follows: for anhydrite a = 409.7, b = -1.764 × 10 -1, c = 2.672 × 10 6, d = -5.130 × 10 3, e = 8.460 × 10 -5; for barite, a = 230.5, b = -0.7395 × 10 -1, c = -1.170 × 10 6, d = -1.587 × 10 3, e = 4.784 × 10 -5; and for celestine, a = 82.1, b = 0.8831 × 10 -1, c = -1.213 × 10 6, d = 0.1890 × 10 3, e = -1.449 × 10 -5. The 95% confidence interval of the measured C p varies from 1 to 2% of the measured value at low temperature up to 2 to 5% at high temperature. The measured thermochemical data improve or augment the thermodynamic database for anhydrous sulfates and highlight the remaining discrepancies.

Majzlan, J.; Navrotsky, A.; Neil, J. M.

2002-05-01

240

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

2010-12-02

241

Improved Method for Preparation of Feces for Bomb Calorimetry.  

National Technical Information Service (NTIS)

As a preliminary to bomb calorimetry, weighed, homogenized fecal slurries are prefrozen and lyophilized. Advantages of this method over the method of drying in a vacuum oven include: more moisture is removed from the sample initially, drying time is reduc...

E. J. Stork H. G. Lovelady

1969-01-01

242

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

243

DSC: software tool for simulation-based design of control strategies applied to wastewater treatment plants.  

PubMed

This paper presents a computer tool called DSC (Simulation based Controllers Design) that enables an easy design of control systems and strategies applied to wastewater treatment plants. Although the control systems are developed and evaluated by simulation, this tool aims to facilitate the direct implementation of the designed control system to the PC of the full-scale WWTP (wastewater treatment plants). The designed control system can be programmed in a dedicated control application and can be connected to either the simulation software or the SCADA of the plant. To this end, the developed DSC incorporates an OPC server (OLE for process control) which facilitates an open-standard communication protocol for different industrial process applications. The potential capabilities of the DSC tool are illustrated through the example of a full-scale application. An aeration control system applied to a nutrient removing WWTP was designed, tuned and evaluated with the DSC tool before its implementation in the full scale plant. The control parameters obtained by simulation were suitable for the full scale plant with only few modifications to improve the control performance. With the DSC tool, the control systems performance can be easily evaluated by simulation. Once developed and tuned by simulation, the control systems can be directly applied to the full-scale WWTP. PMID:21330730

Ruano, M V; Ribes, J; Seco, A; Ferrer, J

2011-01-01

244

State of water in extremely halophilic bacteria: Freezing transitions of Halobacterium halobium observed by differential scanning calorimetry  

Microsoft Academic Search

Summary The apparent latent heat of fusion (?H) of thick pastes ofHalobacterium halobium was determined by differential scanning calorimetry and compared with values obtained for a control paste of identical composition but containing bacteria already lysed by freezing and thawing. The rationale of the experiment was that, if there were any physico-chemical “abnormality” in the state of intracellular water or

A. D. Brown; Julian M. Sturtevant

1980-01-01

245

AC Calorimetry of Sub-Milligram Crystals  

NASA Astrophysics Data System (ADS)

The specific heat measurement has been made using a high resolution ac calorimetric technique. This method is well suited for the sub-milligram crystals that we have studied in this thesis. Various materials have been investigated near their phase transitions: charge density wave transitions --blue bronze (K_{0.3}MoO _3) (180K), monophosphate tungsten bronzes (P_4W_{12 }O44 and P_4W_8O 12) (50-120K) and ZrTe _3 (63K); anion-ordering transitions (AO) --(TMTSF)_2ReO_4 (180K), (TMTSF)_2BF_4 (38K); and orientational ordering transition--C 60 (260K) single crystals. The heat capacity anomalies at second order phase transitions have been analyzed in terms of the mean-field theory (for ZrTe_3), a first order correction to mean-field (for blue bronze), and in terms of a 3D XY crossover model (for blue bronze). For ZrTe _3, the triangular function approximation was adopted to estimate the mean-field like step ( Deltac_{rm MF} ~0.065R). For blue bronze, we have attempted to fit the data to different models; the Gaussian fit is poor near T_{rm c}, indicating the wide critical region required. The fit to a 3D XY crossover model for blue bronze is good near T_{rm c} as well as away from T_{rm c}. From this fit, we estimate Deltac _{rm MF} = 0.18R, which is 4 times that estimated from the mean-field theory, as expected for a one dimensional system. In addition to the large anomaly at the CDW transition, secondary anomalies below T_{rm c}, not reflected in their electronic properties, have been observed for blue bronze and P_4 W12O 44, suggesting that there may be subtle structural (i.e., ordering) changes below the CDW transition. Large lambda-like anomalies, implying a latent heat, have been observed at the anion-ordering transitions in the organic conductors and the orientational ordering transition in C60. The entropy changes, associated with their phase transitions, have been estimated by subtracting smooth backgrounds. The entropy change is less than the expected value of Rln2 for the perrhenate salt, suggesting that there may be residual order above T_{rm c} or disorder below T_{rm c} . The Young's modulus has also been measured, using the vibrating reed technique, on (TMTSF)_2 ReO_4 and (TMTSF) _2BF_4 crystals. For the perrhenate, the discrepancy in shape between the heat capacity (lambda-like) and the Young's modulus (simple step) implies that the phase transition has a first order nature, despite the absence of hysteresis or supercooling. The transition in (TMTSF)_2BF _4 is more sluggish than that in (TMTSF) _2ReO_4. For C60, the specific heats for fcc and orthorhombic crystals have been measured in the temperature range 30K to 300K. At its orientational ordering transitions, the estimated entropy change for the orthorhombic crystal is Delta S~Rln12, consistent with published values. The glassy transition near 90K for the fcc crystal has not been resolved in our ac method, due to a long relaxational time constant. The ac results have been compared with DSC results.

Chung, Moonkyo

246

Determination of the enthalpy of phase change materials by inverse method from calorimetric experiments. Applications to pure substances or binary solutions  

NASA Astrophysics Data System (ADS)

The aim of this paper is to present an inverse identification method to determine specific enthalpy of PCM from calorimetry experiments. We will focus on the cases of pure substances and ideal binary solutions including the eutectic equilibrium. The corresponding direct model, based on energy balance, is first presented. A classical enthalpy method is then used, which presents the advantage of easily decoupling the thermal transfers from the specific energetic behavior of the material (i.e. thermodynamical phenomenon). In the second part of the paper, we will present the used inverse method (genetic algorithms). The sensibilities of the different parameters for the identification are analyzed. Finally, we will present the identification from DSC experiments (1) at different rates of heating for pure substances and (2) at different concentrations of aqueous solutions of NHACl. In each case, we identify the thermodynamical parameters of the model and compare the corresponding thermograms with the experimental ones. A good agreement is obtained for both cases.

Gibout, Stéphane; Maréchal, William; Franquet, Erwin; Bédécarrats, Jean-Pierre; Haillot, Didier; Dumas, Jean-Pierre

2012-11-01

247

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

248

Application of the DSC-Element method to flexural vibration of skew plates with continuous and discontinuous boundaries  

Microsoft Academic Search

This paper generalizes the newly developed DSC-Element method for free vibration analysis of skew plates using the first-order shear deformable plate theory. Basically, the DSC-Element method not only embraces the discrete singular convolution (DSC) delta type wavelet kernel as a trial function with the Ritz principle, but also incorporates the concept of the finite element method. The current approach is

S. K. Lai; L. Zhou; Y. Y. Zhang; Y. Xiang

2011-01-01

249

Perfusion calorimetry in the characterization of solvates forming isomorphic desolvates.  

PubMed

In this study, the potential of perfusion calorimetry in the characterization of solvates forming isomorphic desolvates was investigated. Perfusion calorimetry was used to expose different hydrates forming isomorphic desolvates (emodepside hydrates II-IV, erythromycin A dihydrate and spirapril hydrochloride monohydrate) to stepwise increasing relative vapour pressures (RVP) of water and methanol, respectively, while measuring thermal activity. Furthermore, the suitability of perfusion calorimetry to distinguish the transformation of a desolvate into an isomorphic solvate from the adsorption of solvent molecules to crystal surfaces as well as from solvate formation that is accompanied by structural rearrangement was investigated. Changes in the samples were confirmed using FT-Raman and FT-IR spectroscopy. Perfusion calorimetry indicates the transformation of a desolvate into an isomorphic solvate by a substantial exothermic, peak-shaped heat flow curve at low RVP which reflects the rapid incorporation of solvent molecules by the desolvate to fill the structural voids in the lattice. In contrast, adsorption of solvent molecules to crystal surfaces is associated with distinctly smaller heat changes whereas solvate formation accompanied by structural changes is characterized by an elongated heat flow. Hence, perfusion calorimetry is a valuable tool in the characterization of solvates forming isomorphic desolvates which represents a new field of application for the method. PMID:21726637

Baronsky, Julia; Preu, Martina; Traeubel, Michael; Urbanetz, Nora Anne

2011-06-25

250

Thermogravimetry and differential scanning calorimetry of natural and synthetic melanins  

Microsoft Academic Search

The thermal stability of natural melanins from bovine eyes, black human hair and the hard core of banana peel, synthetic melanins obtained enzymatically or by autoxidation of various precursors, and chemically modified synthetic melanins was studied by DSC and TG analysis. It was shown that the resistance of melanins to thermal degradation depends on their origin. Synthetic melanins were found

B. Simonovic; V. Vucelic; A. Hadzi-Pavlovic; K Stepien; T. Wilczok; D. Vucelic

1990-01-01

251

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

252

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

253

Determination of the Avrami exponent of partially crystallized polymers by DSC (DTA) analyses  

Microsoft Academic Search

This paper presents a new method for a rapid determination of the Avrami exponentn by nonisothermal thermoanalytic analysis (DSC and DTA, resp.). Contrary to conventional techniques this method can be used in the entire temperature range and therefore it is applicable to polymers crystallizing from the melt.

K. Harnisch; H. Muschik

1983-01-01

254

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

255

DSC and EPR investigation of the effect of fat crystallization on the consistency of butter  

Microsoft Academic Search

It was possible to determine the liquid fat content and melting behaviour of butters unenriched and enriched in low melting point milk fat fraction (mp=10‡C) made from traditionally (6-11-11‡C) and heat step technology ripened (6-20-11‡C) cream by using EPR spectroscopy and ultrasensitive DSC methods.

B. Schäffer; D. L?rinczy; S. Szakály

1996-01-01

256

Pulse calorimetry with a light bulb  

Microsoft Academic Search

A normal light bulb provides excellent opportunities for learning modern calorimetric techniques. The tungsten filament in a light bulb allows calorimetric measurements to be made over a wide range of high temperatures. The filament serves simultaneously as a sample, a heater and a thermometer. A student experiment employing a pulse calorimetric technique is described. A brief review of existing calorimetric

Yaakov Kraftmakher

2004-01-01

257

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

258

Characterization of RDF properties through high pressure differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

High Pressure Differential Scanning Calorimetry was employed to study the thermal analytical properties of refuse derived fuels (RDF). By comparison with studies on newsprint and polyethylene, four characteristic thermogram peaks are identified with the smoldering combustion of plastics, cellulosic materials and two types of char respectively. Similarities and differences between thermograms of refuse derived fuels and coal samples are noted. The variability of thermal analytical properties as a function of process parameters, sampling, and source was determined. Finally, data from pyrolytic studies using thermogravimetry as well as scanning calorimetry are presented.

Tsang, W.; Walker, J. A.

1982-02-01

259

DSC Deconvolution of the Structural Complexity of c-MYC P1 Promoter G-Quadruplexes  

Microsoft Academic Search

We completed a biophysical characterization of the c-MYC proto-oncogene P1 promoter quadruplex and its interaction with a cationic porphyrin, 5,10,15,20-tetra(N-methyl-4-pyridyl)porphyrin (TMPyP4), using differential scanning calorimetry, isothermal titration calorimetry, and circular dichroism spectroscopy. We examined three different 24-mer oligonucleotides, including the wild-type (WT) sequence found in the c-MYC P1 promoter and two mutant G?T sequences that are known to fold into

Robert Buscaglia

2011-01-01

260

Phase transitions of monoglyceride emulsifier systems and pearlescent effects in cosmetic creams studied by 13C NMR spectroscopy and DSC  

Microsoft Academic Search

The present work investigates the phase transitions of monoglyceride emulsifier systems and pearlescent effects in cosmetic creams using 13C-NMR spectroscopy and DSC. The four phases of monoglyceride emulsifier systems – the coagel, gel phase, liquid-crystalline lamellar phase, and cubic phase – can be characterized in creams at appropriate temperatures by NMR spectroscopy. The phase transition temperatures were determined by DSC.

Cécile Alberola; Bernhard Blümich; Detlef Emeis; Klaus-Peter Wittern

2006-01-01

261

Direct calorimetry in ecological energetics. Long term monitoring of aquatic animals.  

PubMed

The measurement of heat production represents the most general approach to the estimation of energy flow through biological systems. While aerobic energy metabolism is most conveniently studied by polarographic oxygen determination, direct calorimetry presents the only unspecific method for quantitative comparison of aerobic and anoxic metabolism in animals. In flow calorimeters constant experimental conditions may be controlled for practically unlimited periods of time, and transitions of the environmental regime may be repeatedly performed during one experiment. The merits of a direct calorimetric flow system are demonstrated in case studies of anoxic and aerobic animal metabolism and discussed in the context of current biochemical and ecophysiological concepts. PMID:296722

Gnaiger, E

1979-01-01

262

Determination of Acid/Base Properties by Temperature Programmed Desorption (TPD) and Adsorption Calorimetry  

NASA Astrophysics Data System (ADS)

The characterization of the acidity of zeolites and related materials is of great importance for applications of these materials, particularly in the petrochemical industry and environmental sciences. This chapter provides a comparison of the two most widely used techniques for the study of acid/base properties of zeolites, namely temperature-programmed desorption and adsorption calorimetry. The information needed to perform and interpret these experiments as well as advantages and limitations of these methods are summarized. The curves and data obtained for the two most studied zeolites Y and ZSM-5 are discussed, which can be particularly useful for young researchers in this field.

Damjanovi?, Ljiljana; Auroux, Aline

263

Hadron Calorimetry - what have we learned since CALOR 1?  

NASA Astrophysics Data System (ADS)

In this talk, I review what has been learned about hadron calorimetry since the CALOR conference series started (1990) and I will give my view on how further progress can be made. I will also discuss some developments that may prevent further progress.

Wigmans, Richard

2011-04-01

264

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

265

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

266

Automated, eight-cage indirect calorimetry in rats  

Microsoft Academic Search

We have constructed an automated, eight-cage indirect calorimeter (AIC) for the measurement of energy expenditure in rats. We compared the measurements of resting energy expenditure (REE) in rats during a 30-h fast obtained with the AIC with those obtained with a manual indirect calorimetry (MIC) system. There was both a high degree of correlation between the two techniques during the

James D Luketich; Kathryn E Michel; Paul G Curcillo; David A Rigberg; Mark E Weiss; Irene D Feurer; James L Mullen

1998-01-01

267

Study of the use of lead fluoride for electromagnetic calorimetry.  

National Technical Information Service (NTIS)

A study has been made on the properties of lead fluoride as a Cherenkov material for use in electromagnetic calorimetry. A prototype calorimeter module consisting of a 5 (times) 5 array of 2.1 (times) 2.1 (times) 18.5 cm(sup 3) crystals has been built and...

C. L. Woody J. A. Kierstead P. W. Levy S. Stoll A. B. Weingarten

1992-01-01

268

Heats of fusion for some triglycerides by differential scanning calorimetry  

Microsoft Academic Search

Heats of fusion of tristearin, tripalmitin, trimyristin, trilaurin and several standards were determined by the relatively\\u000a new technique of Differential Scanning Calorimetry. The data obtained on the standards shows good precision and accuracy.\\u000a The results obtained for the triglycerides are 1–10% lower than values which have been reported elsewhere.

J. W. Hampson; H. L. Rothbart

1969-01-01

269

Condensed Complexes and the Calorimetry of Cholesterol-Phospholipid Bilayers  

Microsoft Academic Search

A recent thermodynamic model describes a reversible reaction between cholesterol (C) and phospholipid (P) to form a condensed complex CnqPnp. Here q and p are relatively prime integers used to define the stoichiometric composition, and n is a measure of cooperativity. The present study applies this model to the scanning calorimetry of binary mixtures of cholesterol and saturated phosphatidylcholines, especially

Thomas G. Anderson; Harden M. McConnell

2001-01-01

270

Modulated differential scanning calorimetry in the glass transition region  

Microsoft Academic Search

Temperature-modulated differential scanning calorimetry (TMDSC) is based on heat flow and represents a linear system for the measurement of heat capacity. As long as the measurements are carried out close to steady state and only a negligible temperature gradient exists within the sample, quantitative data can be gathered as a function of modulation frequency. Applied to the glass transition, such

B. Wunderlich; A. Boller; I. Okazaki; S. Kreitmeier

1996-01-01

271

Temperature-modulated differential scanning calorimetry: theory and application  

Microsoft Academic Search

The status of temperature-modulated differential scanning calorimetry is reviewed, including current methods of data analysis, and the experimental conditions and calibrations necessary for meaningful data interpretation. The theory and application of TMDSC to absolute heat capacity measurements, the glass transition, and crystallization and melting are also reviewed and discussed.

Sindee L Simon

2001-01-01

272

Fast sampling calorimetry with solid argon ionization chambers  

SciTech Connect

A proposal for the fast sampling calorimetry with solid argon as active medium and the preliminary results from the solid argon test cell are presented. The proposed test calorimeter module structure, the signal routing and the mechanical and cryogenic arrangements are also discussed.

Clark, E.; Linn, S.; Piekarz, H.; Wahl, H.; Womersley, J. [Florida State Univ., Tallahassee, FL (United States); Hansen, S.; Hurh, P.; Rivetta, C.; Sanders, R.; Schmitt, R.; Stanek, R.; Stefanik, A. [Fermi National Accelerator Lab., Batavia, IL (United States)

1992-12-31

273

Calorimetry at a future e+e- collider  

NASA Astrophysics Data System (ADS)

The requirements on calorimetry for future e+e- linear colliders are formulated. Approaches and recent R&D results for electromagnetic and hadron calorimeters for the TESLA detector are given. Supported by the Ministry of Education of the Czech Republic under the project LN00A006.

Cvach, J.

2003-04-01

274

Mapping glycoside hydrolase substrate subsites by isothermal titration calorimetry  

Microsoft Academic Search

Relating thermodynamic parameters to structural and biochemical data allows a better understanding of substrate binding and its contribution to catalysis. The analysis of the binding of carbohydrates to proteins or enzymes is a special challenge because of the multiple interactions and forces involved. Isothermal titration calorimetry (ITC) provides a direct measure of binding enthalpy (Ha) and allows the determination of

Gennady Zolotnitsky; Uri Cogan; Noam Adir; Vered Solomon; Gil Shoham; Yuval Shoham

2004-01-01

275

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

276

Crosslinking on ageing of elastomers: I. Photoageing of EPDM monitored by gel, swelling and DSC measurements  

Microsoft Academic Search

The crosslinking reactions occurring during the photo-oxidation of EPDM have been examined by measuring changes in gel fraction, degree of swelling and freezing point by Differential Scanning Calorimetry. The correlation with the variation of the carbonyl index showed that the crosslinking process was very efficient (similar to that obtained by peroxide vulcanization) and occurred at the very early stages of

Mohamed Baba; Jean-Luc Gardette; Jacques Lacoste

1999-01-01

277

The enthalpy of fusion and degree of crystallinity of polymers as measured by DSC  

Microsoft Academic Search

Crystalline polymers are not in thermal equilibrium and thermodynamic parameters such as enthalpy of fusion as determined by differential scanning calorimetry from the area under the melting endotherm over a wide temperature range have not been measured under equilibrium conditions. Accordingly measurements of the degree of crystallinity based on the enthalpy of fusion reflect experimental conditions, are incorrect in that

Y. Kong; J. N. Hay

2003-01-01

278

Precipitation kinetics of AA4032 and AA6082: a comparison based on DSC and TEM  

Microsoft Academic Search

The objective of this note is to utilize the macroscopic theory in order to obtain an additional criterion for the identification of the nature of the precipitates. To this aim the formulation of the activation energy for the growth of precipitates is used in conjunction with differential calorimetry performed at different scanning velocities. In the following section the authors critically

G. Birolia; G. Cagliotiab; L. Martini; G. Riontino

1998-01-01

279

Differential scanning calorimetry and /sup 2/H NMR studies of the phase behavior of gramicidin-phosphatidylcholine mixtures  

SciTech Connect

The extents of two-phase coexistence in the phase diagrams of mixtures of gramicidin with 1,2-bis(perdeuteriopalmitoyl)-sn-glycero-3-phosphocholine (DPPC-d62) and with 1,2-bis(perdeuteriomyristoyl)-sn-glycero-3-phosphocholine (DMPC-d54) mixtures have been explored with differential scanning calorimetry (DSC) and deuterium nuclear magnetic resonance (/sup 2/H NMR). For both systems, increased gramicidin content causes a decrease in transition enthalpy and a broadening of the peak in excess heat capacity at the transition. In DMPC-d54-based mixtures, the broadening is roughly symmetric about the pure lipid transition temperature. Addition of gramicidin to DPPC-d62 extends the excess heat capacity peak on the low-temperature side, resulting in a slightly asymmetric scan. Deuterium NMR spectra showing a superposition of gel and liquid-crystalline components, observed for both mixtures, indicate the presence of two-phase coexistence. For the DPPC-d62-based mixtures, two-phase coexistence is restricted to an approximately 2 degrees C temperature range below the pure transition temperature. For DMPC-d54-based mixtures, the region of two-phase coexistence is even narrower. For both mixtures, beyond a gramicidin mole fraction of 2%, distinct gel and liquid-crystal contributions to the spectra cannot be distinguished. Along with the broad featureless nature of the DSC scan in this region, this is taken to indicate that the transition has been replaced by a continuous phase change. These results are consistent with the existence of a closed two-phase region having a critical concentration of gramicidin below 2 mol%.

Morrow, M.R.; Davis, J.H.

1988-03-22

280

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

281

Interaction of poly( l -lysines) with negatively charged membranes: an FT-IR and DSC study  

Microsoft Academic Search

The influence of the binding of poly(l-lysine) (PLL) to negatively charged membranes containing phosphatidylglycerols (PG) was studied by DSC and FT-IR spectroscopy.\\u000a We found a general increase in the main transition temperature as well as increase in hydrophobic order of the membrane upon\\u000a PLL binding. Furthermore we observed stronger binding of hydration water to the lipid head groups after PLL

Christian Schwieger; Alfred Blume

2007-01-01

282

Crystallization and Melting of Polycarbonate Studied by Temperature-Modulated DSC (TMDSC)  

Microsoft Academic Search

Temperature-modulated DSC (TMDSC) measurements at reasonably high frequencies allow for the determination of base-line heat\\u000a capacity. In this particular case vitrification and devitrification of the rigid amorphous fraction (RAF) can be directly\\u000a observed. 0.01 Hz seems to be a reasonably high frequency for bisphenol-A polycarbonate (PC). The RAF of PC is established\\u000a during isothermal crystallization. Devitrification of the RAF seems

C. Schick; A. Wurm; M. Merzlyakov; A. Minakov; H. Marand

2001-01-01

283

Temperature Modulated DSC (TMDSC) Applications and Limits of Phase Information, cp Determination and Effect Separation  

Microsoft Academic Search

The ADSC (Alternating DSC [1]) technique superimposes upon the conventional constant heating rate a periodically varying modulation\\u000a [2–8]. The modulation creates high instantaneous heating rates which increases sensitivity. The low underlying constant heating\\u000a rate is used to get better resolution. With ADSC it is possible to separate overlapping thermal effects without loss of sensitivity\\u000a and to determine heat capacities under

U. Jörimann; G. Widmann; R. Riesen

1999-01-01

284

Hybrid Tandem Solar Cells: CIGS/DSC with Carbon Nanotube Interlayer  

NASA Astrophysics Data System (ADS)

Multi-junction solar cells enable harvesting of wider regions of the solar radiation spectrum leading thereby to increased overall efficiencies. We present here a first study of a hybrid monolithic structure composed of dye sensitized solar cells (DSCs) with thin film inorganic CIGS. We have created several architectures of monolithic multi-junction cells and address fundamental connectivity issues by using sheets of strong, transparent carbon nanotubes (T-CNTs) recently produced at UTD [1] as a uniform interlayer platform. Free-standing T-CNT networks can be laminated onto any surface and their advanteges as transparent interlayers in tandems is shown here for a tandem in which a un-finished CIGS ( top ITO is absent) is coated by T-CNTs. Such CIGS with T-CNT shows Voc=0.6 V and Isc ˜ 10 mA/cm2. It has been combined with DSC playing role of a photoactive counter-electrode, with iodine based electrolyte and Ru-dye on TiO2 mesoscopic electrode. The tandem demonstrated Voc= 0.82 V, which is higher than Voc of our sole DSC-CNT and Isc= 1mA/cm2, smaller than photocurrent of single DSC due to unbalanced current. The physics of processes of charge recombination in hybrid tandems is discussed . [1] M. Zhang, S. Fang, A. Zakhidov, S. B. Lee, A. Aliev, R.H. Baughman, Science, 309,(2005) 1215

Zakhidov, Anvar; Shafarman, William; Zhang, Mei; Fang, Shaoli; Baughman, Ray

2007-03-01

285

A quantum-mechanical study of ZnO and TiO2 based DSC  

NASA Astrophysics Data System (ADS)

Since the pioneering work of Graetzel, Dye Sensitized Cells (DSCs) have attracted great attention as cheap and effective solar power devices based on wide bandgap metal oxide electrode. Optimization of the DSC is a challenging task as it is a highly complex interacting molecular system. Surface properties of the metal-oxide and proper sensitization with dyes may strongly affect the efficiency. Optimizated DSCs based on TiO2 photoanodes and organic dye have reached conversion efficiency of about 10% whereas the efficiency of ZnO based DSC has been found to be much lower, although this material has photochemical properties similar to TiO2, in general due to the nature of the binding between sensitizer and semiconductor. For this reason understanding how anchoring groups interact with the metal-oxide is fundamental to shed light on the different behaviour of these materials in DSC. Aim of this work is to address the binding of small organic sensitizers, such as catechol and isonicotinic acid molecules, to TiO2 and ZnO surfaces, in terms of geometry, stability, electronic structure and absorption properties. To this end, we employed quantum-mechanical simulations based on hybrid DFT and hybrid TDDFT.

Risplendi, Francesca; Cicero, Giancarlo; Mallia, Giuseppe; Bernasconi, Leonardo; Harrison, Nicholas

2012-02-01

286

Study of the phase behavior of polyethylene glycol 6000-itraconazole solid dispersions using DSC.  

PubMed

The aim of the present study was to investigate the phase behavior of solid dispersions made up of PEG 6000 and itraconazole using DSC. Solid dispersions were prepared by solvent evaporation. DSC analysis of pure PEG 6000 showed three endothermic events, representing the melting transitions of the three different crystal modifications. It was shown that itraconazole decreased the formation of the polymer modifications with melting transitions at 56 and 59 degrees C but promoted the formation of the modification with a melting transition at 63 degrees C. All dispersions investigated showed the presence of crystalline itraconazole indicating that the drug is not molecularly dispersed in the polymer matrix. However, the presence of an endothermic peak in DSC curves of all solid dispersions at approximately 85-90 degrees C showed that at least a second phase of pure itraconazole is present also: glassy itraconazole. The protective effect of the polymer is clear at low concentration of drug since no recrystallisation exotherm can be detected. However, at drug concentrations at or above 80%, a recrystallization exotherm at approximately 117 degrees C can be detected. At least three different phases can be distinguished at room temperature: a polymer phase, crystalline itraconazole and glassy itraconazole. The findings of the present study thus demonstrate the coexistence of multiple drug phases in a solid dispersion. PMID:15019081

Wang, Xin; Michoel, Armand; Van den Mooter, Guy

2004-03-19

287

Non-linear dynamics of the wall touching kink mode and Hiro current simulation with DSC  

NASA Astrophysics Data System (ADS)

The Disruption Simulation Code (DSC) was initially implemented in 2D (single helicity) with all basic MHD components of the full 3D version. It performs adaptive, meshless free-boundary ideal one-fluid MHD simulations of plasma separated from conducting in-vessel structures by a vacuum region. Vacuum fields, the plasma surface and wall currents are calculated using both Green's functions and Poisson equation methods. Two non-linear regimes of the wall touching kink mode were simulated for the first time: (a) a fast ideal MHD regime till the saturation due to excitation of the Hiro currents in a tile covered plasma facing surface, and (b) a slower regime of the current quench due to resistive decay of the Hiro currents. Corresponding sideways forces applied to the plasma facing components and to the vacuum vessel were calculated. Progress on the 3D DSC extension of ideal one fluid MHD is presented. Implementation of the full 3D resistive MHD will be outlined. Together with realistic wall model this will enable DSC to address the MHD issues of the entire disruption problem and to move forward for understanding opportunities for mitigation and prediction of disruptions in ITER.

Galkin, S. A.; Svidzinski, V. A.; Evstatiev, E. G.; Zakharov, L. E.

2011-11-01

288

Physics of Compensating Calorimetry and the New CALOR89 Code System.  

National Technical Information Service (NTIS)

Much of the understanding of the physics of calorimetry has come from the use of excellent radiation transport codes. A new understanding of compensating calorimetry was introduced four years ago following detailed studies with a new CALOR system. Now, th...

T. A. Gabriel J. E. Brau B. L. Bishop

1988-01-01

289

Physics of Compensating Calorimetry and the New CALOR89 Code System.  

National Technical Information Service (NTIS)

Much of the understanding of the physics of calorimetry has come from the use of excellent radiation transport codes. A new understanding of compensating calorimetry was introduced four years ago following detailed studies with a new CALOR system. Now, th...

T. A. Gabriel J. E. Brau B. L. Bishop

1989-01-01

290

Evaluation of the interaction of coumarins with biomembrane models studied by differential scanning calorimetry and Langmuir-Blodgett techniques.  

PubMed

Three coumarins, scopoletin (1), esculetin (2), and esculin (3), were investigated by differential scanning calorimetry and Langmuir-Blodgett techniques to gain information about the interaction of these compounds with cellular membranes. Phospholipids assembled as multilamellar vesicles or monolayers (at the air-water interface) were used as biomembrane models. Differential scanning calorimetry was employed to study the interaction of these coumarins with multilamellar vesicles and to evaluate their absorption by multilamellar vesicles. These experiments indicated that 1-3 interact in this manner to different extents. The Langmuir-Blodgett technique was used to study the effect of these coumarins on the organization of phospholipids assembled as a monolayer. The data obtained were in agreement with those obtained in the calorimetric experiments. PMID:21417386

Sarpietro, Maria Grazia; Giuffrida, Maria Chiara; Ottimo, Sara; Micieli, Dorotea; Castelli, Francesco

2011-03-18

291

Measurement of the wax appearance temperatures of crude oils by temperature modulated differential scanning calorimetry  

Microsoft Academic Search

Temperature modulated differential scanning calorimetry (TMDSC) is used for the first time to measure the wax appearance temperature (WAT) of crude oil samples. The commercial implementation of TMDSC chosen for this study is alternating differential scanning calorimetry (ADSC) marketed by Mettler-Toledo. We show that changes in the ADSC signals exhibit excellent correlations with WATs measured using conventional differential scanning calorimetry,

Z Jiang; J. M Hutchinson; C. T Imrie

2001-01-01

292

Application of kinetic inductance thermometers to X-ray calorimetry  

NASA Astrophysics Data System (ADS)

A kinetic inductance thermometer is applied to X-ray calorimetry, and its operation over a wide range of frequencies and geometries is discussed. Three amplifier configurations are described, one using a superconducting quantum interference device (SQUID) amplifier, another incorporating an FET amplifier in an amplitude modulated system, and the third, using a tunnel diode frequency modulated oscillator circuit. The predicted performance of each configuration is presented.

Wai, Yolanda C.; Labov, Simon E.; Silver, Eric H.

1990-11-01

293

Differential scanning calorimetry of palm kernel oil products  

Microsoft Academic Search

A variety of fractionated and hydrogenated fats were derived from a commercial sample of Malayan palm kernel oil. These were\\u000a studied by differential scanning calorimetry at different rates of cooling and heating. The resulting thermograms, and latent\\u000a heats derived from them, were compared with one another and with underlying triglyceride compositions. This enabled three\\u000a potential interpretations of the thermograms to

J. B. Rossell

1975-01-01

294

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

295

The Philosophy and Feasibility of Dual Readout Calorimetry  

NASA Astrophysics Data System (ADS)

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

2006-10-01

296

Glass transition of heterogeneous polymeric systems studied by calorimetry  

Microsoft Academic Search

This personal review focuses on two aspects. First, glass transition dynamics and hence also calorimetry is connected to dynamic\\u000a heterogeneity. This results in an interplay of the corresponding dynamic length scales and length scales from structural heterogeneities\\u000a in polymeric samples. Second, the complexity of the dynamic glass transition itself results in different effects of this interplay\\u000a for different experimental observables.

K. Schröter

2009-01-01

297

The application of temperature-modulated DSC to the glass transition region  

Microsoft Academic Search

An analysis of temperature-modulated differential scanning calorimetry (TMDSC) in the glass transition region is presented. It extends an earlier and simpler model by introducing a distribution of relaxation times, characterised by a Kohlrausch–Williams–Watts (KWW) stretched exponential parameter ?, in addition to the usual kinetic parameters of relaxation, namely the Tool–Narayanaswamy–Moynihan (TNM) non-linearity parameter x and the apparent activation energy ?h?.

J. M. Hutchinson; S. Montserrat

2001-01-01

298

Temperature modulated DSC study of the kinetics of free radical isothermal network polymerization  

Microsoft Academic Search

Temperature modulated differential scanning calorimetry (TMDSC) is used to study the kinetics of the free radical isothermal\\u000a polymerization of triethyleneglycol dimethacrylate (TEGDMA). Azo-bis-isobutironitrile was used as initiator. The polymerization’s temperature is lower than the final glass transition temperature\\u000a of the polymer network. The measurement of the average heat flow released and the heat capacity during the reaction allows\\u000a identifying the

M. T. Viciosa; J. Quiles Hoyo; M. Dionísio; J. L. Gómez Ribelles

2007-01-01

299

DSC and spectroscopic investigation of human serum albumin adsorbed onto silica nanoparticles functionalized by amino groups  

Microsoft Academic Search

Human serum albumin (HSA) adsorbed onto silica nanoparticles modified by 3-aminopropyltriethoxysilane (APTES) and polyethyleneimine\\u000a (PEI) was investigated by differential scanning calorimetry, IR spectroscopy, and photon correlation spectroscopy. The structural\\u000a alterations of the protein molecules induced from adsorption process were estimated on the basis of temperatures of denaturation\\u000a transition (T\\u000a d) of the protein in free (native) and adsorbed form. It

Elena V. ParfenyukGalina; Galina A. Kulikova; Irina V. Ryabinina

2010-01-01

300

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

301

Use of thermal analysis techniques (TG-DSC) for the characterization of diverse organic municipal waste streams to predict biological stability prior to land application.  

PubMed

The use of organic municipal wastes as soil amendments is an increasing practice that can divert significant amounts of waste from landfill, and provides a potential source of nutrients and organic matter to ameliorate degraded soils. Due to the high heterogeneity of organic municipal waste streams, it is difficult to rapidly and cost-effectively establish their suitability as soil amendments using a single method. Thermal analysis has been proposed as an evolving technique to assess the stability and composition of the organic matter present in these wastes. In this study, three different organic municipal waste streams (i.e., a municipal waste compost (MC), a composted sewage sludge (CS) and a thermally dried sewage sludge (TS)) were characterized using conventional and thermal methods. The conventional methods used to test organic matter stability included laboratory incubation with measurement of respired C, and spectroscopic methods to characterize chemical composition. Carbon mineralization was measured during a 90-day incubation, and samples before and after incubation were analyzed by chemical (elemental analysis) and spectroscopic (infrared and nuclear magnetic resonance) methods. Results were compared with those obtained by thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques. Total amounts of CO(2) respired indicated that the organic matter in the TS was the least stable, while that in the CS was the most stable. This was confirmed by changes detected with the spectroscopic methods in the composition of the organic wastes due to C mineralization. Differences were especially pronounced for TS, which showed a remarkable loss of aliphatic and proteinaceous compounds during the incubation process. TG, and especially DSC analysis, clearly reflected these differences between the three organic wastes before and after the incubation. Furthermore, the calculated energy density, which represents the energy available per unit of organic matter, showed a strong correlation with cumulative respiration. Results obtained support the hypothesis of a potential link between the thermal and biological stability of the studied organic materials, and consequently the ability of thermal analysis to characterize the maturity of municipal organic wastes and composts. PMID:21944875

Fernández, José M; Plaza, César; Polo, Alfredo; Plante, Alain F

2011-09-25

302

Comparative SAXS and DSC study on stratum corneum structural organization in an epidermal cell culture model (ROC): Impact of cultivation time.  

PubMed

Cell cultured skin equivalents present an alternative for dermatological in vitro evaluations of drugs and excipients as they provide the advantage of availability, lower variability and higher assay robustness compared to native skin. For penetration/permeation studies, an adequate stratum corneum barrier similar to that of human stratum corneum is, however, a prerequisite. In this study, the stratum corneum lipid organization in an epidermal cell culture model based on rat epidermal keratinocytes (REK organotypic culture, ROC) was investigated by small-angle X-ray scattering (SAXS) in dependence on ROC cultivation time and in comparison to native human and rat stratum cornea. In addition, the thermal phase behavior was studied by differential scanning calorimetry (DSC) and barrier properties were checked by measurements of the permeability of tritiated water. The development of the barrier of ROC SC obtained at different cultivation times (7, 14 and 21days at the air-liquid interface) was connected with an increase in structural order of the SC lipids in SAXS measurements: Already cultivation for 14days at the air-liquid interface resulted overall in a competent SC permeability barrier and SC lipid organization. Cultivation for 21days resulted in further minor changes in the structural organization of ROC SC. The SAXS patterns of ROC SC had overall large similarities with that of human SC and point to the presence of a long periodicity phase with a repeat distance of about 122Å, e.g. slightly smaller than that determined for human SC in the present study (127Å). Moreover, SAXS results also indicate the presence of covalently bound ceramides, which are crucial for a proper SC barrier, although the corresponding thermal transitions were not clearly detectable by DSC. Due to the competent SC barrier properties and high structural and organizational similarity to that of native human SC, ROC presents a promising alternative for in vitro studies, particularly as it can be obtained under overall rather straightforward cell culture conditions and thus low assay costs. PMID:23770376

Kuntsche, Judith; Herre, Angela; Fahr, Alfred; Funari, Sérgio S; Garidel, Patrick

2013-06-11

303

Use of thermal analysis techniques (TG-DSC) for the characterization of diverse organic municipal waste streams to predict biological stability prior to land application  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Thermal analysis was used to assess stability and composition of organic matter in three diverse municipal waste streams. Black-Right-Pointing-Pointer Results were compared with C mineralization during 90-day incubation, FTIR and {sup 13}C NMR. Black-Right-Pointing-Pointer Thermal analysis reflected the differences between the organic wastes before and after the incubation. Black-Right-Pointing-Pointer The calculated energy density showed a strong correlation with cumulative respiration. Black-Right-Pointing-Pointer Conventional and thermal methods provide complimentary means of characterizing organic wastes. - Abstract: The use of organic municipal wastes as soil amendments is an increasing practice that can divert significant amounts of waste from landfill, and provides a potential source of nutrients and organic matter to ameliorate degraded soils. Due to the high heterogeneity of organic municipal waste streams, it is difficult to rapidly and cost-effectively establish their suitability as soil amendments using a single method. Thermal analysis has been proposed as an evolving technique to assess the stability and composition of the organic matter present in these wastes. In this study, three different organic municipal waste streams (i.e., a municipal waste compost (MC), a composted sewage sludge (CS) and a thermally dried sewage sludge (TS)) were characterized using conventional and thermal methods. The conventional methods used to test organic matter stability included laboratory incubation with measurement of respired C, and spectroscopic methods to characterize chemical composition. Carbon mineralization was measured during a 90-day incubation, and samples before and after incubation were analyzed by chemical (elemental analysis) and spectroscopic (infrared and nuclear magnetic resonance) methods. Results were compared with those obtained by thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques. Total amounts of CO{sub 2} respired indicated that the organic matter in the TS was the least stable, while that in the CS was the most stable. This was confirmed by changes detected with the spectroscopic methods in the composition of the organic wastes due to C mineralization. Differences were especially pronounced for TS, which showed a remarkable loss of aliphatic and proteinaceous compounds during the incubation process. TG, and especially DSC analysis, clearly reflected these differences between the three organic wastes before and after the incubation. Furthermore, the calculated energy density, which represents the energy available per unit of organic matter, showed a strong correlation with cumulative respiration. Results obtained support the hypothesis of a potential link between the thermal and biological stability of the studied organic materials, and consequently the ability of thermal analysis to characterize the maturity of municipal organic wastes and composts.

Fernandez, Jose M., E-mail: joseman@sas.upenn.edu [Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA 19104-6316 (United States); Plaza, Cesar; Polo, Alfredo [Instituto de Ciencias Agrarias, Consejo Superior de Investigaciones Cientificas, Serrano 115 dpdo., 28006 Madrid (Spain); Plante, Alain F. [Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA 19104-6316 (United States)

2012-01-15

304

Rheological Behavior, Granule Size Distribution and Differential Scanning Calorimetry of Cross-Linked Banana (Musa paradisiaca) Starch.  

NASA Astrophysics Data System (ADS)

Rheological behavior at 60 °C, granule size distribution and Differential Scanning Calorimetry (DSC) tests were employed to study the effect of diverse reaction conditions: adipic acid concentration, pH and temperature during cross-linking of banana (Musa paradisiaca) starch. These properties were determined in native banana starch pastes for the purpose of comparison. Rheological behavior from pastes of cross-linked starch at 60 °C did not show hysteresis, probably due the cross-linkage of starch that avoided disruption of granules, elsewhere, native starch showed hysteresis in a thixotropic loop. All pastes exhibited non-Newtonian shear thinning behavior. In all cases, size distribution showed a decrease in the median diameter in cross-linked starches. This condition produces a decrease in swelling capacity of cross-linked starch. The median diameter decreased with an increase of acid adipic concentration; however, an increase of pH and Temperature produced an increase in this variable. Finally, an increase in gelatinization temperature and entalphy (?H) were observed as an effect of cross-linkage. An increase in acid adipic concentration produced an increase in Tonset and a decrease in ?H. pH and temperature. The cross-linked of banana starch produced granules more resistant during the pasting procedure.

Núñez-Santiago, María C.; Maristany-Cáceres, Amira J.; Suárez, Francisco J. García; Bello-Pérez, Arturo

2008-07-01

305

Determination of specific heat of milk at different fat content between 1 °C and 59 °C using micro DSC  

Microsoft Academic Search

The apparent specific heat of different milks varying in fat mass contents from 0.1% to 35%, were determined in the temperature range 1–59°C by means of a continuous differential scanning calorimeter (DSC) method. The DSC measurement procedure was tested for reliability with distilled water before applying it to the milk samples which varied in fat content. The influence of temperature

Jin Hu; Osmann Sari; Sara Eicher; A. Rija Rakotozanakajy

2009-01-01

306

DSC and Raman spectra of ? and ?-Endosulfan plus 60/40 mixture  

NASA Astrophysics Data System (ADS)

The symmetrical ?-conformer of endosulfan has the identical chemical composition of the asymmetrical ?-conformer, and both have very different melting/boiling points. The ?- and ?-isomer however have markedly different Raman spectra at each of 50°C, 75°C and 100°C. Moreover, the commercially available Raman spectra of the 60/40 (?-/?-) mixture at the same temperatures is discrete from either a- and b-isomer alone. Previous research demonstrated that at a- boiling point 110°C, ?-conformer partially converts to ?-. DSC curves of mixtures suggest thermal interactions and conformational changes occurs in BOTH ?- and ?-isomer at temperatures even 60°C lower than the liquid/gas phase transition.

Schmidt, Walter F.; Nguyen, Julie K.; Qin, Jianwei; Kim, Moon S.; Mookherji, Swati; McConnell, Laura L.; Hapeman, Cathleen J.

2013-05-01

307

TG-DSC method applied to drying characteristics and heat requirement of cotton stalk during drying  

NASA Astrophysics Data System (ADS)

Drying characteristics of cotton stalk were investigated at four temperatures (60, 80, 100 and 120 °C) using a simultaneous thermal analyzer (TG-DSC). Heat requirements of cotton stalk during drying were calculated ranging from 189 to 406 kJ/kg. Consequently, Midilli-Kucuk model showed the best fit to experimental drying data. The values of effective diffusivity ranged from 4.38 × 10-9 to 8.15 × 10-9 m2/s, and the activation energy was calculated to be 11.6 kJ/mol.

Chen, Dengyu; Li, Ming; Zhu, Xifeng

2012-12-01

308

A new approach for non-contact calorimetry: system identification using pseudo-white noise perturbation  

NASA Astrophysics Data System (ADS)

This paper presents a new technique for non-contact calorimetry measurement of specific heat capacity and thermal conductivity. Based on pseudo-white noise modulation and system identification, commonly used in electronics and communication engineering, this procedure can be used to measure the transfer function of the sample temperature variation due to heating power variation. The heat capacity and internal heat transfer coefficient are then determined using the equivalence between the identified transfer functions of the temperatures measured at two locations and the analytical model proposed by Fecht and Johnson (Rev Sci Instrum 62:1299-1303, 1991) and Wunderlich and Fecht (Measur Sci Technol 16:402-416, 2005). This inverse problem is solved numerically using a Gauss-Seidel algorithm. A numerical simulation of a non-contact modulated calorimetry experiment is used to demonstrate the relevance of this new technique for indirect measurement of the heat capacity and heat transfer coefficients of solid samples presenting large Biot numbers ( Bi > 0.4).

Schetelat, Pascal; Etay, Jacqueline

2011-07-01

309

Morphology of blends of linear and long-chain-branched polyethylenes in the solid state: A study by SANS, SAXS, and DSC  

SciTech Connect

Differential scanning calorimetry (DSC), small-angle neutron scattering (SANS), and X-ray scattering (SAXS) have been used to investigate the solid-state morphology of blends of linear (high density) and long-chain-branched (low-density) polyethylenes (HDPE/LDPE). The blends are homogeneous in the melt, as previously demonstrated by SANS using the contrast obtained by deuterating the linear polymer. However, due to the structural and melting point differences ({approximately} 20 C) between HDPE and LDPE, the components may phase segregate on slow cooling (0.75 C/min). For high concentrations ({phi} {ge} 0.5) of HDPE, relatively high rates of crystallization of the linear component lead to the formation of separate stacks of HDPE and LDPE lamellae, as indicated by two-peak SAXS curves. For predominantly branched blends, the difference in crystallization rate of the components becomes smaller and only one SAXS peak is observed, indicating that the two species are in the same lamellar stack. Moreover, the phases no longer consist of the pure component and the HDPE lamellae contain up to 15--20% LDPE (and vice versa). Rapid quenching into dry ice/2-propanol ({minus}78 C) produces only one SAXS peak (and hence one lamellar stack) over the whole concentration range. The blends show extensive cocrystallization, along with a tendency for the branched material to be preferentially located in the amorphous interlamellar regions. For high concentrations ({phi} > 0.5) of HDPE-D, the overall scattering length density (SLD) is high and the excess concentration of LDPE between the lamellae enhances the SLD contrast between the crystalline and amorphous phases. Thus, the interlamellar spacing (long period) is clearly visible in the SANS pattern. The blend morphology is a strong function of the quenching rate, and samples quenched less rapidly (e.g., into water at 23 C) are similar to slowly cooled blends.

Wignall, G.D.; Londono, J.D.; Lin, J.S. [Oak Ridge National Lab., TN (United States); Alamo, R.G.; Galante, M.J.; Mandelkern, L. [Florida State Univ., Tallahassee, FL (United States)

1995-04-24

310

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

311

Comparison of curdlan and its carboxymethylated derivative by means of Rheology, DSC, and AFM.  

PubMed

Curdlan was carboxymethylated in an aqueous alkaline medium using monochloroacetic acid as the etherifying agent. The structure of carboxymethylated curdlan (CMc) was analyzed by FT-IR and NMR spectroscopy, which revealed that the carboxymethyl group was introduced mainly at the C-6 position as well as at the C-2 and C-4 positions. Furthermore, CMc was compared with the native curdlan by using rheology and DSC methods. It was found that in water, both polysaccharides behaved as pseudoplastic fluids and fit the power law and Herschel-Bulkley rheological models well. Both the storage shear modulus G' and the loss shear modulus G'' of CMc aqueous solutions decreased and became more frequency dependent with decreasing concentration in comparison with the curdlan aqueous suspensions. The modulus-temperature curve also suggested that the gel characteristic of curdlan has been lost after chemical modification, which is consistent with the DSC results. AFM images revealed differences in the conformation of native and carboxymethylated curdlan, which changed from the aggregation of macromolecules to triple helices. All the experimental results suggest that the hydrogen bonds that bind curdlan with interstitial water to form the micelles have been destroyed completely and that the hydrophobic interactions related to the methylene groups at C-6 formed above 55 degrees C disappeared due to the introduction of the hydrophilic carboxymethyl group. PMID:16310757

Jin, Yang; Zhang, Hongbin; Yin, Yimei; Nishinari, Katsuyoshi

2005-11-28

312

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.

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

313

Water Flow Calorimetry System of EAST Neutral Beam Injector  

NASA Astrophysics Data System (ADS)

Neutral beam injection (NBI) is recognized as one of the most effective means of plasma heating. The EAST NBI water flow calorimetry system (WFCS) based on PCI extensions for instrumentation (PXI) was established, it can measure temperature rise and flow rate of cooling water of the heat load components, and achieve beam power distribution and neutralization efficiency. Experimental data obtained from WFCS are feedback of the ion source operation state and direct the operation parameter optimization of the ion source. Experimental results show that the WFCS is stable, reliable, and meet the experimental requirements fully.

Yu, Ling; Hu, Chundong; Liu, Sheng; Xu, Yongjian

2013-10-01

314

Multiwavelength laser rate calorimetry on various infrared window materials  

Microsoft Academic Search

The effective optical absorption coefficient obtained by the slope method of laser calorimetry is presented for a number of materials at a variety of laser wavelengths. The materials studied include MgF2, NaCl, KCl, LiYF4, CaF2, LiF, YAG, Al2O3 (sapphire), SiO2, BaF2,SrF2, CORTRAN 9753 and 9754 glass, ZBT glass, GGG, MgO-Al2O3 (spinel), ZnSe, MgO, Si, As2S3, ZnS, and calcium aluminate glasses.

N. C. Fernelius; G. S. Coble; D. V. Dempsey; J. A. Detrio; J. A. Fox; P. R. Greason; G. T. Johnston; D. B. Oquinn

1982-01-01

315

Fabrication of 12% {sup 240}Pu calorimetry standards  

SciTech Connect

Throughout the DOE complex, laboratories are performing calorimetric assays on items containing high burnup plutonium. These materials contain higher isotopic range and higher wattages than materials previously encountered in vault holdings. Currently, measurement control standards have been limited to utilizing 6% {sup 240}Pu standards. The lower isotopic and wattage value standards do not complement the measurement of the higher burnup material. Participants of the Calorimetry Exchange (CALEX) Program have identified the need for new calorimetric assay standards with a higher wattage and isotopic range. This paper describes the fabrication and verification measurements of the new CALEX standard containing 12% {sup 240}Pu oxide with a wattage of about 6 to 8 watts.

Long, S.M.; Hildner, S.; Gutierrez, D.; Mills, C.; Garcia, W.; Gurule, C.

1995-08-01

316

Freeze-out of carbon monoxide in calorimetry tests  

SciTech Connect

The amount of carbon monoxide recovered from calorimetry tests of high explosives is far larger than the amount predicted by equilibrium calculations. The present analysis shows that chemical reactions which produce CH{sub 4} are the most important ones to lead to equilibrium below 1000 K but are effectively blocked by a rapid cooling of the calorimetric bomb. Furthermore, reaction CO + H{sub 2}O -> H{sub 2} + CO{sub 2}, which is the key reaction at T > 1000 K slows down at lower temperatures. The observed overabundance of CO is a direct consequence of both factors.

Ree, F.H.; Pitz, W.J.; Thiel, M. van [and others

1995-08-22

317

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

318

The use of calorimetry in nuclear materials management  

SciTech Connect

A calorimeter is a device to measure evolved or adsorbed heat. For our purposes, the heat measured is that associated with radioactive decay and the unit of measurement is the watt. Each time an atom decays, energy is released and absorbed by the surroundings and heat generated. For each isotope, this heat is a constant related to the energy of the decay particles and the half-life of the isotope. A point which is often overlooked is that calorimetry is one of the oldest techniques known for measuring radioactivity. In 1903, Pierre Curie and A. Laborde used a twin microcalorimeter to determine that one gram of radium generates about 100 calories per hour. Several months later, Curie and Dewar used liquid oxygen and hydrogen to show that the amount of energy developed by radium and other radioactive elements did not depend on temperature. At that time, this observation was extremely important. It indicated that the nature of radioactivity is entirely different and cannot be compared with any known phenomena. In all other thermal processes known in physics and chemistry, the rate at which heat is developed changes with temperature. In 1942, Monsanto was asked by General Leslie Groves, Head of the Manhattan Project, to accept the responsibility for the chemistry and metallurgy of radioactive polonium. Late in 1943, two Monsanto scientists began a study of the half-life of polonium-210 using calorimetry.

Nutter, J.D.; O`Hara, F.A.; Rodenburg, W.W.

1996-07-01

319

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

320

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

ScienceCinema

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.

321

Comparison of dual-echo DSC-MRI- and DCE-MRI-derived contrast agent kinetic parameters  

PubMed Central

The application of dynamic susceptibility contrast (DSC) MRI methods to assess brain tumors is often confounded by the extravasation of contrast agent (CA). Disruption of the blood–brain barrier allows CA to leak out of the vasculature leading to additional T1, T2 and T2? relaxation effects in the extravascular space, thereby affecting the signal intensity time course in a complex manner. The goal of this study is to validate a dual-echo DSC-MRI approach that separates and quantifies the T1 and T2? contributions to the acquired signal and enables the estimation of the volume transfer constant, Ktrans, and the volume fraction of the extravascular extracellular space, ?e. To test the validity of this approach, DSC-MRI- and dynamic contrast enhanced (DCE) MRI-derived Ktrans and ?e estimates were spatially compared in both 9L and C6 rat brain tumor models. A high degree of correlation (concordance correlation coefficients >0.83, Pearson's r>0.84) and agreement was found between the DSC-MRI- and DCE-MRI-derived measurements. These results indicate that dual-echo DSC-MRI can be used to simultaneously extract reliable DCE-MRI kinetic parameters in brain tumors in addition to conventional blood volume and blood flow metrics.

Quarles, C. Chad; Gore, John C.; Xu, Lei; Yankeelov, Thomas E.

2012-01-01

322

Structural study by DSC, SAXS, and Raman spectroscopy of silica aerogel  

NASA Astrophysics Data System (ADS)

The structure of silica acrogel, a porous low density material having small particle size prepared from TMOS has been investigated by DSC, SAXS, and Raman spectroscopy. The predominant particle size of the aerogel were determined to be near 3 nm by SAXS analysis. The Raman spectra are qualitatively similar to those from fused silica, although the sample before heat treatment had typical Raman peaks assigned to organic groups contained in TMOS. The observed relatively intense peaks at near 490 and 606 cm-1 suggest the existence of small rings, e.g., six(3-SiO) or eight(4-SiO) membered, in the aerogel. The structure change of the aerogel with temperature was also studied by Raman spectroscopy.

Igarashi, K.; Tajiri, K.; Tai, Y.; Tanemura, S.

1993-03-01

323

PALS and DSC studies in high energy electron irradiated semicrystalline polypropylene  

NASA Astrophysics Data System (ADS)

The effect of 8 MeV electron irradiation on the microstructure of the free volume in semicrystalline Polypropylene (PP) has been studied by Positron Annihilation Lifetime Spectroscopy (PALS). DSC has been employed to observe the variation in specific heat (Cp) as functions of electron dose and temperature. The Positron lifetime spectra for different electron doses are deconvoluted into three components, of which longest lived component (?3) signifies the pick-off annihilation of o-Ps at free volume site which is related to the radius of the free volume holes. A gradual decrease in Cp values with increase of irradiation dose is found which may be expected as the free volume increases with the same.

Mandal, Arunava; Mukherjee, Subrata; Pan, Sandip; Saha, Achintya Kumar; Sengupta, Asmita

2013-06-01

324

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

PubMed

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 are more symmetric than predicted by a simple irreversible model. In the presence of taurodeoxycholate (TDOC), the unfolding temperature is lower and the unfolding is reversible. We conclude that an early reversible unfolding intermediate exists in which a number of additional hydrophobic patches are exposed to the solvent, or preferentially are covered with TDOC. Improvement of the stability of cutinase with respect to both surfactants and thermal denaturation, should thus be directed toward the prevention of exposure of hydrophobic patches in the early intermediate. PMID:11527580

Creveld, L D; Meijberg, W; Berendsen, H J; Pepermans, H A

2001-08-30

325

Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime Using Controlled Calorimetry  

SciTech Connect

A comprehensive description of the accomplishments of the DOE grant titled, ''Local Measurement of Fuel Energy Deposition and Heat Transfer Environment During Fuel Lifetime using Controlled Calorimetry''.

Don W. Miller; Andrew Kauffmann; Eric Kreidler; Dongxu Li; Hanying Liu; Daniel Mills; Thomas D. Radcliff; Joseph Talnagi

2001-12-31

326

SSB binding to ssDNA using isothermal titration calorimetry.  

PubMed

Isothermal titration calorimetry (ITC) is a powerful method for studying protein-DNA interactions in solution. As long as binding is accompanied by an appreciable enthalpy change, ITC studies can yield quantitative information on stoichiometries, binding energetics (affinity, binding enthalpy and entropy) and potential site-site interactions (cooperativity). This can provide a full thermodynamic description of an interacting system which is necessary to understand the stability and specificity of protein-DNA interactions and to correlate the activities or functions of different species. Here we describe procedures to perform and analyze ITC studies using as examples, the E. coli SSB (homotetramer with 4 OB-folds) and D. radiodurans SSB (homodimer with 4 OB-folds). For oligomeric protein systems such as these, we emphasize the need to be aware of the likelihood that solution conditions will influence not only the affinity and enthalpy of binding but also the mode by which the SSB oligomer binds ssDNA. PMID:22976176

Kozlov, Alexander G; Lohman, Timothy M

2012-01-01

327

Revisiting the optimal c value for isothermal titration calorimetry.  

PubMed

The precision with which the dissociation constant, K(D), can be obtained from isothermal titration calorimetry depends on, among other factors, the concentrations of the interacting species. The so-called c value-the ratio of analyte concentration to K(D)-should fall in the range of 1 to 1000 for reliable K(D) determination. On the basis of simulated, noise-free data, Biswas and Tsodikov [5] recently suggested an optimal c value of 5 to 20. By contrast, we find an optimum at c > 40 on determining the K(D) confidence intervals through simulations containing noise levels typical of state-of-the-art microcalorimeters. PMID:21854755

Broecker, Jana; Vargas, Carolyn; Keller, Sandro

2011-07-30

328

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

329

A novel photomultiplier tube for calorimetry at the SSC  

SciTech Connect

A silicon target photomultiplier tube with an anode consisting of a large area Avalanche Photodiode (APD) has been developed. The tube combines the advantages of an avalanche photodiode, excellent linearity and large dynamic range, with the properties of a phototube. The tube structure is proximity focussing, which is not affected by high magnetic fields approximately aligned with the axis. The high linearity makes this device attractive for calorimetry at the SSC. The extension of this concept to an APD array will provide a cost effective fiber readout for both digital (tracking) and analogue applications. A tube equipped with an APD array is being developed currently as a readout option for the SDC Shower Maximum Detector.

Cushman, P. [Yale Univ., New Haven, CT (United States); Iosue, M.; Johnson, B. [Litton Electron Devices, Tempe, AZ (United States); Madden, M.; Szawlowski, M. [Advanced Photonix Inc., Los Angeles, CA (United States); Rusack, R. [Rockefeller Univ., New York, NY (United States)

1992-09-01

330

A novel photomultiplier tube for calorimetry at the SSC  

SciTech Connect

A silicon target photomultiplier tube with an anode consisting of a large area Avalanche Photodiode (APD) has been developed. The tube combines the advantages of an avalanche photodiode, excellent linearity and large dynamic range, with the properties of a phototube. The tube structure is proximity focussing, which is not affected by high magnetic fields approximately aligned with the axis. The high linearity makes this device attractive for calorimetry at the SSC. The extension of this concept to an APD array will provide a cost effective fiber readout for both digital (tracking) and analogue applications. A tube equipped with an APD array is being developed currently as a readout option for the SDC Shower Maximum Detector.

Cushman, P. (Yale Univ., New Haven, CT (United States)); Iosue, M.; Johnson, B. (Litton Electron Devices, Tempe, AZ (United States)); Madden, M.; Szawlowski, M. (Advanced Photonix Inc., Los Angeles, CA (United States)); Rusack, R. (Rockefeller Univ., New York, NY (United States))

1992-01-01

331

Effect of amino acids on the eutectic behavior of NaCl solutions studied by DSC.  

PubMed

The effect of a series of amino acids on the eutectic behavior of NaCl solutions at isotonic concentration has been studied by differential scanning calorimetry. The inclusion of different amino acids had different effects on eutectic formation. The amino acids were grouped into four categories based on their effect on eutectic formation: category C were amino acids that had no effect on eutectic formation; category D amino acids inhibited eutectic formation; category T amino acids shifted the melting of the eutectic to a lower temperature; category E amino acids caused the formation of a new eutectic with a melting temperature approximately -5 degrees C. The mechanism of these different effects on eutectic behavior is discussed, based on the chemical structure of the amino acids. PMID:15925578

Chen, N J; Morikawa, J; Hashimoto, T

2005-04-09

332

Analysis of the Escherichia coli glucosamine-6-phosphate synthase activity by isothermal titration calorimetry and differential scanning calorimetry.  

PubMed

Glucosamine-6-phosphate synthase (GlmS) is responsible for the first and rate-limiting step in the hexosamine biosynthetic pathway. It catalyzes the conversion of D-fructose-6P (F6P) into D-glucosamine-6P (GlcN6P) using L-glutamine (Gln) as nitrogen donor (synthase activity) according to an ordered bi-bi process where F6P binds first. In the absence of F6P, the enzyme exhibits a weak hydrolyzing activity of Gln into Glu and ammonia (glutaminase activity), whereas the presence of F6P strongly stimulates it (hemi-synthase activity). Until now, these different activities were indirectly measured using either coupled enzyme or colorimetric methods. In this work, we have developed a direct assay monitoring the heat released by the reaction. Isothermal titration calorimetry and differential scanning calorimetry were used to determine kinetic and thermodynamic parameters of GlmS. The direct determination at 37 degrees C of kinetic parameters and affinity constants for both F6P and Gln demonstrated that part of the ammonia produced by Gln hydrolysis in the presence of both substrates is not used for the formation of the GlcN6P. The full characterization of this phenomenon allowed to identify experimental conditions where this leak of ammonia is negligible. Enthalpy measurements at 25 degrees C in buffers of various heats of protonation demonstrated that no proton exchange with the medium occurred during the enzyme-catalyzed glutaminase or synthase reaction suggesting for the first time that both products are released as a globally neutral pair composed by the Glu carboxylic side chain and the GlcN6P amine function. Finally we showed that the oligomerization state of GlmS is concentration-dependent. PMID:20416269

Valerio-Lepiniec, Marie; Aumont-Nicaise, Magali; Roux, Céline; Raynal, Bertrand; England, Patrick; Badet, Bernard; Badet-Denisot, Marie-Ange; Desmadril, Michel

2010-04-20

333

Pressure-differential scanning calorimetry of coals, organic compounds, and polymers  

SciTech Connect

Pressure differential scanning calorimetry (PDSC) has been found to be a useful technique for the rapid measurement of heat of combustion of coals. A typical experiment involves heating a 1 to 1.5 mg sample at a linear rate of 20/sup 0/C/min over the range of 150 to 500/sup 0/C, in a 3.5 MPa atmosphere of oxygen. For most coals, the resulting thermogram consists of two exothermic peaks, the relative intensity of which varies in a characteristic way with coal rank. The experiments on coal were supplemented with measurements on over 30 model compounds and about 50 polymers. The exotherm occurring at the lower temperature was found to arise from the aliphatic portion of the coal structure and the exotherm at higher temperature, from the aromatic portion. A value of the aromaticity can be deduced from the relative intensities of the two peaks; such values generally agree with data obtained for similar coals by solid state nuclear magnetic resonance. The maximum of the aromatic peak shifts to higher temperatures with increasing ring condensation. Thus, from a single PDSC experiment it is possible to measure the heating value and to deduce rank, aromaticity, and ring condensation. Our current research seeks to use PDSC technique to study variations in aromaticity with depth in the seam, and variations in aromaticity and ring condensation among coal lithotypes. 6 figures.

Benson, S.A.; Groon, K.S.; Schobert, H.H.

1983-01-01

334

Cerebral perfusion alterations in epileptic patients during peri-ictal and post-ictal phase: PASL vs DSC-MRI.  

PubMed

Non-invasive pulsed arterial spin labeling (PASL) MRI is a method to study brain perfusion that does not require the administration of a contrast agent, which makes it a valuable diagnostic tool as it reduces cost and side effects. The purpose of the present study was to establish the viability of PASL as an alternative to dynamic susceptibility contrast (DSC-MRI) and other perfusion imaging methods in characterizing changes in perfusion patterns caused by seizures in epileptic patients. We evaluated 19 patients with PASL. Of these, the 9 affected by high-frequency seizures were observed during the peri-ictal period (within 5hours since the last seizure), while the 10 patients affected by low-frequency seizures were observed in the post-ictal period. For comparison, 17/19 patients were also evaluated with DSC-MRI and CBF/CBV. PASL imaging showed focal vascular changes, which allowed the classification of patients in three categories: 8 patients characterized by increased perfusion, 4 patients with normal perfusion and 7 patients with decreased perfusion. PASL perfusion imaging findings were comparable to those obtained by DSC-MRI. Since PASL is a) sensitive to vascular alterations induced by epileptic seizures, b) comparable to DSC-MRI for detecting perfusion asymmetries, c) potentially capable of detecting time-related perfusion changes, it can be recommended for repeated evaluations, to identify the epileptic focus, and in follow-up and/or therapy-response assessment. PMID:23623332

Pizzini, Francesca B; Farace, Paolo; Manganotti, Paolo; Zoccatelli, Giada; Bongiovanni, Luigi G; Golay, Xavier; Beltramello, Alberto; Osculati, Antonio; Bertini, Giuseppe; Fabene, Paolo F

2013-04-24

335

Study of temperature profile and specific heat capacity in temperature modulated DSC with a low sample heat diffusivity  

Microsoft Academic Search

One important application of temperature modulated DSC (TMDSC) is the measurement of specific heat of materials. When the sample has very good thermal conductivity as in the case of metals, the temperature gradient is not normally an important factor and can be ignored most of the time. However, in the case of materials with poor heat transfer properties, for example,

S. X. Xu; Y. Li; Y. P. Feng

2000-01-01

336

The Thermal Conductivity Measurements of Solid Samples by Heat Flux Differantial Scanning Calorimetry  

NASA Astrophysics Data System (ADS)

The thermal conductivity of polyvinylchloride (PVC), polysytrene (PS) and polypropylene (PP) were measured by heat flux DSC. Our results are in good agreement with the results observed by different methods.

Kök, M.; Aydo?du, Y.

2007-04-01

337

Role of the DSC1 Channel in Regulating Neuronal Excitability in Drosophila melanogaster: Extending Nervous System Stability under Stress  

PubMed Central

Voltage-gated ion channels are essential for electrical signaling in neurons and other excitable cells. Among them, voltage-gated sodium and calcium channels are four-domain proteins, and ion selectivity is strongly influenced by a ring of amino acids in the pore regions of these channels. Sodium channels contain a DEKA motif (i.e., amino acids D, E, K, and A at the pore positions of domains I, II, III, and IV, respectively), whereas voltage-gated calcium channels contain an EEEE motif (i.e., acidic residues, E, at all four positions). Recently, a novel family of ion channel proteins that contain an intermediate DEEA motif has been found in a variety of invertebrate species. However, the physiological role of this new family of ion channels in animal biology remains elusive. DSC1 in Drosophila melanogaster is a prototype of this new family of ion channels. In this study, we generated two DSC1 knockout lines using ends-out gene targeting via homologous recombination. DSC1 mutant flies exhibited impaired olfaction and a distinct jumpy phenotype that is intensified by heat shock and starvation. Electrophysiological analysis of the giant fiber system (GFS), a well-defined central neural circuit, revealed that DSC1 mutants are altered in the activities of the GFS, including the ability of the GFS to follow repetitive stimulation (i.e., following ability) and response to heat shock, starvation, and pyrethroid insecticides. These results reveal an important role of the DSC1 channel in modulating the stability of neural circuits, particularly under environmental stresses, likely by maintaining the sustainability of synaptic transmission.

Zhang, Tianxiang; Wang, Zhe; Wang, Lingxin; Luo, Ningguang; Jiang, Lan; Liu, Zhiqi; Wu, Chun-Fang; Dong, Ke

2013-01-01

338

DSC and elastic moduli studies on tellurite-vanadate glasses containing antimony oxide  

NASA Astrophysics Data System (ADS)

xSb2O3-40TeO2-(60 - x) V2O5 glasses with 0 ? x ? 10 (in mol%) have been prepared by rapid- melt quenching method. DSC curves of these ternary glasses have been investigated. The glass transition properties that have been measured and reported in this paper, include the glass transition temperature (Tg), glass transition width (?Tg), heat capacity change at glass transition (?CP) and fragility (F). Thermal stability, Poisson's ratio, fragility and glass forming tendency of these glasses have been estimated, to determine relationship between chemical composition and the thermal stability or to interpret the structure of glass. In addition, Makishima and Makenzie's theory was applied for determination of Young's modulus, bulk modulus and shear modulus, indicating a strong relation between elastic properties and structure of glass. Generally, results of this work show that glass with x = 0 has the highest shear, bulk and Young's moduli which make it as suitable candidate for the manufacture of strong glass fibers in technological applications; but it should be mentioned that glass with x = 8 has higher handling temperature and super resistance against thermal attack.

Souri, D.

2011-11-01

339

DSC study of the isothermal crystallization of iPP-CNF nanocomposites  

NASA Astrophysics Data System (ADS)

Nanocomposite materials have been obtained by dispersing vapor grown carbon nanofibers (VGCNFs) with diameters ranging between 60 and 100 nm and lengths between 30,000 and 100,000 nm supplied by Pyrograf Products, Inc (PR-24AG) within a polymer matrix - isotactic polypropylene (iPP) - type Marlex HLN-120-01 with density 0.906 g/cm^3 and melt flow rate at 230 ^oC of 12 g/10 min, supplied by Philips Sumika Polypropylene Company. VGCNFs have been purified and disentangled by reflux in dichloromethane and deionized water followed by vacuum filtering (for 24 h) and drying at 110 ^oC for 24h. The nanocomposites were obtained by melt mixing at 180 ^oC for 9 minutes with a speed of 65 rpm followed by an additional mixing at 90 rpm for 5 minutes, using a HAAKE Rheomix, Nanocomposites loaded with various amounts of VGCNFs (0%, 1%, 2.5%, 5%, 7.5%, 10%, 15%, and 20% wt.) have been prepared and investigated by TA DSC Q-500. Isothermal crystallization was investigated in detail and analyzed by using an expression derived from the Avrami equation. The effect of the filler on the isothermal crystallization of iPP is discussed in detail. The research is focused on the effect of VGCNF on the degree of crystallization of iPP, crystallization rate, and dimensionality of the crystallization process.

Chipara, Dorina M.; Chipara, Mircea

2013-03-01

340

Study of thermal decomposition of methyl ethyl ketone peroxide using DSC and simulation.  

PubMed

Methyl ethyl ketone peroxide (MEKPO) is a typical organic peroxide with thermally unstable nature that has been broadly employed in the manufacturing process of acrylic resins, as a hardening agent for fiberglass-reinforced plastics, and as a curing agent for unsaturated polyester resins. The aim of this study was to identify the characteristics of MEKPO 31 wt.% while mixing with contaminants, such as H(2)SO(4), HCl, and NaCl under runaway conditions. To acquire the thermal runaway data, DSC and a simulation were used for thermal analysis. The results showed that the thermal decomposition of MEKPO and MEKPO+H(2)SO(4) follows two stages. The first one can be modeled by using an empirical nth order rate equation. The second stage can be modeled as autocatalytic. MEKPO+HCl and MEKPO+NaCl included two independent autocatalytic reactions. The decomposition of MEKPO in the presence of Cl- ions (added in MEKPO either in the form of HCl or NaCl) follows a significantly different path, an earlier decomposition "onset" temperature, higher amount of generated thermal power and smaller temperature of no return (T(NR)) and time to maximum rate (TMR) values. Simulations based on experimental data indicated that the effect of H(2)SO(4) was the most dangerous contaminant on MEKPO 31 wt.%. However, the impact of Cl ions was also important. It is therefore recommended that the means of fire fighting employed for this substance to be free of Cl-. PMID:16905247

Tseng, Jo-Ming; Chang, Ying-Yu; Su, Teh-Sheng; Shu, Chi-Min

2006-07-01

341

Application of arrhenius kinetics to evaluate oxidative stability in vegetable oils by isothermal differential scanning calorimetry  

Microsoft Academic Search

In this study, 10 different vegetable oils were oxidized at four different isothermal temperatures (383, 393, 403, and 413\\u000a K) in a differential scanning calorimeter (DSC). The protocol involved oxidizing vegetable oils in a DSC cell with oxygen\\u000a flow. A rapid increase in evolved heat was observed with an exothermic heat flow appearing during initiation of the oxidation\\u000a reaction. From

C. P. Tan; Y. B. Che Man; J. Selamat; M. S. A. Yusoff

2001-01-01

342

Differential scanning calorimetry studies on structural phase transitions and molecular motions in (CH3NH3)2MBr4 and [(CH3)2NH2]2MBr4 (M = Zn, Cd, and Hg)  

NASA Astrophysics Data System (ADS)

Structural phase transitions and molecular motions in (CH3NH3)2MBr4 and in [(CH3)2NH2]2MBr4 (M = Zn, Cd, and Hg) were investigated by differential scanning calorimetry (DSC) between about 130 K and the melting points. All of the compounds showed at least one structural phase transition over the temperature region investigated. The values of the transition entropies obtained suggest that these transitions are of the order-disorder type. N-H...Br hydrogen bonds were found to play an important role in the stability of P21/c room-temperature phases of the title compounds. In the highest-temperature solid phases of all title compounds, orientational orders of cations seem to be completely lost.

Horiuchi, Keizo; Ishihara, Hideta; Terao, Hiromitsu

2000-06-01

343

High-pressure differential scanning calorimetry of colorant products.  

PubMed

High-pressure differential scanning calorimetry (HPDSC) can be used to gain information on both the degree of crystallinity in the intermediate filaments (IFs) and the structural rigidity of the surrounding matrix or intermediate filament associated proteins (IFAP) of the hair cortex (1-3). We have used HPDSC to measure changes in the denaturation temperature (T(D)) and enthalpy (DeltaH(D)) of the crystalline components after multiple treatments with permanent hair colorant products. We have observed that after three repeat treatments both the denaturation enthalpy and peak temperature are significantly decreased vs the untreated starting substrate. However, on dialysis of the fibers in deionized water this decrease is shown to be completely reversible, returning the enthalpy and temperature to that of the untreated hair. It is proposed that the decrease is due to the incorporation of formulation components such as the alkalizer and surfactants etc. and metal ions such as calcium and magnesium from the tap wash water. These components are predicted to have a non-permanent effect on the salt bridges and hydrogen bonds and hence the rigidity or viscosity of the matrix. We have compared the denaturation temperature with the tensile properties of the fiber after treatment both before and after removal of actives from the fiber. PMID:18305875

Marsh, J M; Clarke, C J; Meinert, K; Dahlgren, R M

344

On the feasibility of water calorimetry with scanned proton radiation  

NASA Astrophysics Data System (ADS)

Water calorimetry is considered to be the most direct primary method to realize the physical quantity gray for absorbed dose to water. The Swiss Federal Office of Metrology and Accreditation (METAS) has routinely operated a water calorimeter as primary standard for photon radiation since 2001. Nowadays, cancer therapy with proton radiation has become increasingly important and is a well established method. In the framework of the ProScan project conducted by the Paul Scherrer Institute (PSI), the spot-scanning technique is prepared for the subsequent application in hospitals, and adjusted to the recent findings of clinical research. In the absence of primary standards for proton radiation, the metrological traceability is assured by calibrating secondary standards in 60Co radiation and correcting with calculated beam quality correction factors. It is internationally recognized that the development of primary standards for proton radiation is highly desirable. In a common project of PSI and METAS, it is investigated whether a modified version of the water calorimeter in operation at METAS is suitable as primary standard for scanned proton radiation. A feasibility study has been conducted to investigate the linear energy transfer (LET) dependence of the heat defect and the influence of the time and space structure of the scanned beam on the homogeneity and stability of the temperature field in the water calorimeter. Simulations are validated against experimental data of the existing calorimeter used with photon radiation and extended to scanned proton radiation.

Sassowsky, M.; Pedroni, E.

2005-11-01

345

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.

Sarpietro, Maria Grazia; Castelli, Francesco

2011-01-01

346

SAXS/DSC/WAXD study of temperature evolution in nanocomposite polymer electrolytes with different nanofillers.  

PubMed

Polymer electrolytes are nanostructured materials which are very attractive components for batteries and opto-electronic devices. (PEO)8ZnCl2 polymer electrolytes were prepared from PEO and ZnCl2. The nanocomposites (PEO)8ZnCI2 themselves contained TiO2, Al2O3, MgO, ZnO and V2O5 nanograins. In this work, the influence of the Al2O3, MgO and V2O5 nanograins on the morphology and ionic conductivity of the nanocomposite was systematically studied by transmission small-angle X-ray scattering simultaneously recorded with wide-angle X-ray diffraction and differential scanning calorimetry at the synchrotron ELETTRA (Trieste, Italy). These three measurement methods yielded insight into the temperature-dependent changes of the grains of the electrolyte. The heating and cooling rate was 0.5 degrees C/min. Environment friendly galvanic cells as well as solar cells of the second generation are to be constructed with such nanocomposite polymer as electrolyte. PMID:23421266

Turkovi?, A; Dubcek, P; Jurai?, K; Bernstorff, S

2012-11-01

347

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

2013-03-27

348

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

349

Electromagnetic radiation calorimetry of thermoplastics, elastomers, and composite systems  

SciTech Connect

Microwave radiation for processing of glassy and semicrystalline thermoplastics, elastomeric polymers and composites was investigated. The goal was to reveal the relationship between polymer structure and microwave absorptivity, and hence processability. Specimens were subjected to an electric field at 2.45 GHz either inside a rectangular waveguide or in a cylindrical resonant cavity. Applicator with less than 100 watts applied power. Both travelling wave modes and standing wave modes were examined. Temperatures, powers and times were recorded, leading to the concept of microwave calorimetry. Low frequency dynamic mechanical and dielectric frequency-temperature spectra were obtained on the materials and combined to conveniently extrapolate structure-property relationships into the GHz region. A correlation was found between the dielectric properties of various polymers and the dipole moments of small molecule analogues. Evaluating heatability was most accurately determined by the magnitude of ({epsilon}{sub s} - {epsilon}{sub {infinity}}), the oscillator strength. The value of ({epsilon}{sub s} - {epsilon}{sub {infinity}}) should be used together with the distribution of relaxation times and the activation energies of dipolar dispersion to predict heatability for microwave processing. The critical temperatures, T{sub c}, of dielectric loss were obtained from the intercepts of positive slope tangents of heating rate versus temperature plots at 2.45 GHz for polymers. Microwave processing was rapid above the critical temperature where the maximum dielectric loss fell in the 2.45 GHz frequency domain for efficient coupling of energy to the polymers. Shifting the dielectric relaxation spectrum into the microwave region by directly or indirectly increasing the temperature was unique and of key importance to processability. A schematic model explains the behavior of two-phase materials subjected to microwave heating.

Chen, M.

1989-01-01

350

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

351

Measurement of glass transition temperature by mechanical (DMTA), thermal (DSC and MDSC), water diffusion and density methods: A comparison study  

Microsoft Academic Search

Glass transition measured by DMTA from the change in slope in storage modulus was 55°C, which was 10.5°C lower than the value measured by tan? peak. Initial glass transition measured by DSC, increased exponentially and reached a constant value of 55°C at or higher heating rate of 30°C\\/min. Transition temperature, measured by MDSC, remained constant up to heating rate 15°C\\/min

Mohammad Shafiur Rahman; Insaaf Mohd Al-Marhubi; Abdullah Al-Mahrouqi

2007-01-01

352

DSC study of the influence of p -subtituted diphenyl amines on the thermooxidative stability of styrene-butadiene rubber  

Microsoft Academic Search

Effect of several p- and p,p?-substituted diphenyl amines on the thermooxidative stability of styrene-butadiene rubber (SBR) has been studied using non-isothermal\\u000a DSC measurements with the aim of exploring the relation between the structure of the compound and its antioxidative performance.\\u000a The treatment of the experimental data was carried out by applying a new method based on a non-Arrhenian temperature function.

Zuzana Cibulková; Peter Šimon; Peter Lehocký; Károly Kosár; Ján Uhlár

2010-01-01

353

Investigation on interfacial interaction of flame retarded and glass fiber reinforced PA66 composites by IGC\\/DSC\\/SEM  

Microsoft Academic Search

The interfacial interaction of flame retarded and glass fiber reinforced PA66 composites is a very important issue due to one of the key factors influencing the mechanical properties of materials. In this article, the interfacial interaction among the components in the composites has been studied by IGC\\/DSC\\/SEM techniques. The experimental data demonstrated that Zn2+-modified melamine polyphosphate (Zn–MpolyP) flame retardant could

Xiaohua Huang; Bin Li; Baoli Shi; Liping Li

2008-01-01

354

Isothermal calorimetry investigation of Li{sub 1+x}Mn{sub 2-y}Al{sub z}O{sub 4} spinel.  

SciTech Connect

The heat generation of LiMn{sub 2}O{sub 4}, Li{sub 1.156}Mn{sub 1.844}O{sub 4}, and Li{sub 1.06}Mn{sub 1.89}Al{sub 0.05}O{sub 4} spinel cathode materials in a half-cell system was investigated by isothermal micro-calorimetry (IMC). The heat variations of the Li/LiMn{sub 2}O{sub 4} cell during charging were attributed to the LiMn{sub 2}O{sub 4} phase transition and order/disorder changes. This heat variation was largely suppressed when the stoichiometric spinel was doped with excess lithium or lithium and aluminum. The calculated entropy change (dE/dT) from the IMC confirmed that the order/disorder change of LiMn{sub 2}O{sub 4}, which occurs in the middle of the charge, was largely suppressed with lithium or lithium and aluminum doping. The dE/dT values obtained did not agree between the charge and the discharge at room temperature (25 C), which was attributed to cell self-discharge. This discrepancy was not observed at low temperature (10 C). Differential scanning calorimeter (DSC) results showed that the fully charged spinel with lithium doping has better thermal stability.

Lu, W.; Belharouak, I.; Park, S. H.; Sun, Y. K; Amine, K.; Chemical Engineering; Hanyang Univ.

2007-05-25

355

Differential Scanning Calorimetry Methods in the Determination of Thermal Properties of Explosives.  

National Technical Information Service (NTIS)

Differential Scanning Calorimetry methods are applied in determining heat of fusion, purity, specific heat, and activation energy of decomposition for undiluted, unmixed samples of the high explosives TNR, TNT, tetryl, HMX, RDX, and PETN. Thermograms desc...

J. D. Wilcox

1967-01-01

356

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

357

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

358

Differential Scanning Calorimetry Studies of Some Electrolyte Systems Pertinent to Thermal Batteries.  

National Technical Information Service (NTIS)

The thermal behavior of some electrolyte systems which are potentially useful in thermal batteries has been investigated by differential scanning calorimetry. The reactivity of calcium metal in molten nitrates and thiocyanates has been studied. The nitrat...

D. A. Fine A. N. Fletcher

1978-01-01

359

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

NASA Astrophysics Data System (ADS)

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, Chin-Tu

2006-10-01

360

Proceedings of the Eleventh International Conference on Calorimetry in Particle Physics  

NASA Astrophysics Data System (ADS)

The Pamela silicon tungsten calorimeter / G. Zampa -- Design and development of a dense, fine grained silicon tungsten calorimeter with integrated electronics / D. Strom -- High resolution silicon detector for 1.2-3.1 eV (400-1000 nm) photons / D. Groom -- The KLEM high energy cosmic rays collector for the NUCLEON satellite mission / M. Merkin (contribution not received) -- The electromagnetic calorimeter of the Hera-b experiment / I. Matchikhilian -- The status of the ATLAS tile calorimeter / J. Mendes Saraiva -- Design and mass production of Scintillator Pad Detector (SPD) / Preshower (PS) detector for LHC-b experiment / E. Gushchin -- Study of new FNAL-NICADD extruded scintillator as active media of large EMCal of ALICE at LHC / O. Grachov -- The CMS hadron calorimeter / D. Karmgard (contribution not received) -- Test beam study of the KOPIO Shashlyk calorimeter prototype / A. Poblaguev -- The Shashlik electro-magnetic calorimeter for the LHCb experiment / S. Barsuk -- Quality of mass produced lead-tungstate crystals / R. Zhu -- Status of the CMS electromagnetic calorimeter / J. Fay -- Scintillation detectors for radiation-hard electromagnetic calorimeters / H. Loehner -- Energy, timing and two-photon invariant mass resolution of a 256-channel PBWO[symbol] calorimeter / M. Ippolitov -- A high performance hybrid electromagnetic calorimeter at Jefferson Lab / A. Gasparian -- CsI(Tl) calorimetry on BESHI / T. Hu (contribution not received) -- The crystal ball and TAPS detectors at the MAMI electron beam facility / D. Watts -- Front-end electronics of the ATLAS tile calorimeter / R. Teuscher -- The ATLAS tilecal detector control system / A. Gomes -- Performance of the liquid argon final calibration board / C. de la Taille -- Overview of the LHCb calorimeter electronics / F. Machefert -- LHCb preshower photodetector and electronics / S. Monteil -- The CMS ECAL readout architecture and the clock and control system / K. Kloukinas -- Test of the CMS-ECAL trigger primitive generation / N. Regnault -- Optical data links for the CMS ECAL / J. Grahl (contribution not received) -- CMS ECAL off-detector electronics / R. Alemany Fernandez -- Performance of a low noise readout ASIC for the W-Si calorimeter physics prototype for the future linear collider / C. de la Taille -- Properties of a sampling calorimeter with warm-liquid ionization chambers / S. Plewnia -- Calorimetry and the DO experiment / R. Zitoun (contribution not received) -- Data quality monitoring for the DØ calorimeter / V. Shary -- Status of the construction of the ATLAS electromagnetic liquid argon calorimeter, overview of beam test performance studies / L. Serin -- Uniformity of response of ATLAS liquid argon EM calorimeter / O. Gaunter -- Status of the ATLAS liquid argon hadronic endcap calorimeter construction / M. Vincter -- Results from particle beam tests of the ATLAS liquid argon endcap calorimeters / M. Lefebvre -- First results of the DREAM project / R. Wigmans -- Electron and muon detection with a dual-readout (DREAM) calorimeter / N. Akchurin -- The neutron zero degree calorimeter for the ALICE experiment / M. Gallio -- The liquid xenon scintillation calorimeter of the MEG experiment: operation of a large prototype / G. Signorelli -- Detection of high energy particles using radio frequency signals / C. Hebert -- Hadronic shower simulation / J.-P. Wellisch -- E.M. and hadronic shower simulation with FLUKA / G. Battistoni -- Simulation of the LHCb electromagnetic calorimeter response with GEANT4 / P. Robbe -- Comparison of beam test results of the combined ATLAS liquid argon endcap calorimeters with GEANT3 and GEANT4 simulations / D. Salihagi? -- GEANT4 hadronic physics validation with LHC test-beam data / C. Alexa -- The full simulation of the GLAST LAT high energy gamma ray telescope / F. Longo -- Response of the KLOE electromagnetic calorimeter to low-energy particles / T. Spadaro -- Calorimeter algorithms for DØ; / S. Trincaz-Duvoid -- Identification of low P[symbol] muon with the ATLAS tile calorimeter / G. Usai -- Electron and photon reconstruction

Cecchi, Claudia

361

Development of GEM-based Digital Hadron Calorimetry using the SLAC KPiX chip  

NASA Astrophysics Data System (ADS)

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 1m2 GEM-DHCAL planes to be tested as part of a future calorimeter stack.

White, A.

2010-01-01

362

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

363

Description of cooling water calorimetry and wall thermometry diagnostic at tokamak ASDEX-Upgrade  

Microsoft Academic Search

Hardware and software of the cooling water calorimetry and the wall thermometry diagnostics at the tokamak ASDEX-Upgrade are described. These diagnostics were used to analyze the energy deposition on the first wall elements in ASDEX-Upgrade. The cooling water calorimetry system consists of 130 platinum resistor thermometers Pt-100 and 27 annular flow meters located in the cooling water system of the

Th. Richter; H. Vernickel

1992-01-01

364

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

365

Immersion calorimetry of fine coal particles and its relation to flotation  

SciTech Connect

A Setaram C-80 heat flux microcalorimeter was used to study the surface and interfacial properties of fine coal particles in water containing flotation agents via heat of immersion measurements. Heat of immersion (..delta..H/sub imm/) is usually a small exothermic quantity and can be used to characterize a solid in terms of its relative hydrophobicity or hydrophilicity. The effects of coal type, surface oxidation, mineral matter content, kerosene concentration, and pH on the wetting characteristics were investigated. Although coal is a heterogeneous mixture of organic and inorganic materials, immersional calorimetry has proven to be quite helpful in measuring surface properties of coal, and the following conclusions can be drawn: The heat of immersion decreased with increasing kerosene concentration, which corresponds to the coal particles increasing hydrophobicity; in varying the pH, the ..delta..H/sub imm/ went through a minimum at a pH value of 6.5 to 7.0, which coincides with the reported optimum pH range for flotation; both oxidation and clay slime coating (addition of kaolin), which are known to make the coal less hydrophobic, increased the ..delta..H/sub imm/; and the trends that were shown to exist in the heat of immersion measurements (for varying kerosene concentration, pH oxidation, and clay slime coating) correlated well with independent flotation experiments. 16 refs., 6 figs., 2 tabs.

Melkus, T.G.; Chiang, S.H.; Wen, W.W.

1987-01-01

366

Structural Basis for Fatigue Initiation in Glassy Polymers: Progress Report, August 1, 1988-February 28, 1989.  

National Technical Information Service (NTIS)

Experiments have been conducted to quickly establish whether physical aging is indeed accelerated by fatigue loading. Differential Scanning Calorimetry (DSC) experiments were run on a polycarbonate specimen fatigued at 200 to 2000 psi (tension-tension) at...

A. F. Yee D. W. Gidley

1989-01-01

367

A DSC study of the effects of sugars on thermal properties of rice starch gels before and after aging  

Microsoft Academic Search

Thermal characterization of gelatinized binary rice starch-water and ternary starch-sugar-water gels before and after aging was carried out using differential scanning calorimetry. The glass transition temperature of the maximally freeze-concentrated solution (T?g) in both fresh and aged gels was observed to decrease progressively with increasing sugar concentration. Aging of the gels generally shiftedT?g to higher temperatures, but had little or

C. C. Seow; C. H. Teo; C. K. Vasanti Nair

1996-01-01

368

Heat Capacity Measurements Using Temperature-modulated Heat Flux DSC with Close Control of the Heater Temperature  

Microsoft Academic Search

The determination of heat capacity data with sawtooth-type, temperature-modulated differential scanning calorimetry is analyzed\\u000a using the Mettler-Toledo 820 ADSC™temperature-modulated differential scanning calorimeter (TMDSC). Heat capacities were calculated\\u000a via the amplitudes of the first and higher harmonics of the Fourier series of the heat flow and heating rates. At modulation\\u000a periods lower than about 150 s, the heat capacity deviates increasingly

R. Androsch

2000-01-01

369

Temperature modulated differential scanning calorimetry (TMDSC) in the region of phase transitions. Part 2: some specific results from polymers  

Microsoft Academic Search

By means of four different examples (pressure crystallised, gel crystallised, nascent and highly stretched polyethylenes (PEs)) it is shown that temperature modulated DSC offers advantages against common DSC. It is possible to see dynamic processes inside the sample during melting. This way we found (i) that during melting of high pressure crystallised PE the so-called ?2-process (known from DMA) takes

G. W. H. Höhne

1999-01-01

370

DSC and synchrotron-radiation X-ray diffraction studies on crystallization and polymorphic behavior of palm stearin in bulk and oil-in-water emulsion states  

Microsoft Academic Search

The crystallization and polymorphic behavior of palm stearin (PS) in a bulk state and in oil-in-water (O\\/W) emulsion droplets\\u000a (average diameter, 1.70.3 ?m) was observed by using DSC, optical microscopy, and in situ X-ray diffraction with synchrotron radiation (SR-XRD). For the bulk sample the DSC measurements revealed three main exothermic\\u000a peaks at approximately 31 (large), 21 (small) and 3C (medium)

T. Sonoda; Y. Takata; S. Ueno; K. Sato

2004-01-01

371

Molecular Characterization and Alternative Splicing of a Sodium Channel and DSC1 Ortholog Genes in Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae).  

PubMed

Alternative splicing greatly contributes to the structural and functional diversity of voltage-gated sodium channels (VGSCs) by generating various isoforms with unique functional and pharmacological properties. Here, we identified a new optional exon 23 located in the linker between domains II and III, and four mutually exclusive exons (exons 27A, 27B, 27C, and 27D) in domains IIIS3 and IIIS4 of the sodium channel of Liposcelis bostrychophila (termed as LbVGSC). This suggested that more alternative splicing phenomena remained to be discovered in VGSCs. Inclusion of exon 27C might lead to generation of non-functional isoforms. Meanwhile, identification of three alternative exons (exons 11, 13A, and 13B), which were located in the linker between domains II and III, indicated that abundant splicing events occurred in the DSC1 ortholog channel of L. bostrychophila (termed as LbSC1). Exons 13A and 13B were generated by intron retention, and the presence of exon 13B relied on the inclusion of exon 13A. Exon 13B was specifically expressed in the embryonic stage and contained an in-frame stop codon, inclusion of which led to generation of truncated proteins with only the first two domains. Additionally, several co-occurring RNA editing events were identified in LbSC1. Furthermore, remarkable similarity between the structure and expression patterns of LbVGSC and LbSC1 were discovered, and a closer evolutionary relationship between VGSCs and DSC1 orthologs was verified. Taken together, the data provided abundant molecular information on VGSC and DSC1 orthologs in L. bostrychophila, a representative Psocoptera storage pest, and insights into the alternative splicing of these two channels. PMID:24155671

Jiang, Xuan-Zhao; Wei, Dan-Dan; Yang, Wen-Jia; Dou, Wei; Chen, Shi-Chun; Wang, Jin-Jun

2013-09-26

372

Molecular Characterization and Alternative Splicing of a Sodium Channel and DSC1 Ortholog Genes in Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae)  

PubMed Central

Alternative splicing greatly contributes to the structural and functional diversity of voltage-gated sodium channels (VGSCs) by generating various isoforms with unique functional and pharmacological properties. Here, we identified a new optional exon 23 located in the linker between domains II and III, and four mutually exclusive exons (exons 27A, 27B, 27C, and 27D) in domains IIIS3 and IIIS4 of the sodium channel of Liposcelis bostrychophila (termed as LbVGSC). This suggested that more alternative splicing phenomena remained to be discovered in VGSCs. Inclusion of exon 27C might lead to generation of non-functional isoforms. Meanwhile, identification of three alternative exons (exons 11, 13A, and 13B), which were located in the linker between domains II and III, indicated that abundant splicing events occurred in the DSC1 ortholog channel of L. bostrychophila (termed as LbSC1). Exons 13A and 13B were generated by intron retention, and the presence of exon 13B relied on the inclusion of exon 13A. Exon 13B was specifically expressed in the embryonic stage and contained an in-frame stop codon, inclusion of which led to generation of truncated proteins with only the first two domains. Additionally, several co-occurring RNA editing events were identified in LbSC1. Furthermore, remarkable similarity between the structure and expression patterns of LbVGSC and LbSC1 were discovered, and a closer evolutionary relationship between VGSCs and DSC1 orthologs was verified. Taken together, the data provided abundant molecular information on VGSC and DSC1 orthologs in L. bostrychophila, a representative Psocoptera storage pest, and insights into the alternative splicing of these two channels.

Jiang, Xuan-Zhao; Wei, Dan-Dan; Yang, Wen-Jia; Dou, Wei; Chen, Shi-Chun; Wang, Jin-Jun

2013-01-01

373

Determination of complex-specific heat and fragility of sodium borate glasses by temperature-modulated DSC  

Microsoft Academic Search

The frequency dependences of the complex-specific heat of the sodium borate glasses, xNa2O·(100 ? x)B2O3, where x denotes molar concentration of Na2O, have been investigated by temperature-modulated DSC. The temperature dependences of ?-relaxation time have been analyzed\\u000a in Angell plot, and the fragility index has been determined. The composition dependence of the fragility index has been discussed\\u000a on the basis of the

Yasuteru Fukawa; Yu Matsuda; Mitsuru Kawashima; Seiji Kojima

2010-01-01

374

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

375

The use of differential scanning calorimetry to study the effects of gentamycin on fibrous collageneous membranes  

Microsoft Academic Search

The protein collagen is the most predominant and important protein of the skin and therefore its physicochemical and thermal properties are important to be known. DSC has been applied in order to study the thermal changes caused by using different concentrations of the gentamycin antibiotic in fibrous membranes FM, named AMATCOL at different scanning rates. The thermal effect consisting of

E. Siapi; T. Mavromoustakos; V. Trandafir; B. Albu; P. Budrugeac

2005-01-01

376

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

2012-11-26

377

Tin clusters that do not melt: Calorimetry measurements up to 650 K  

NASA Astrophysics Data System (ADS)

Recent theoretical studies [K. Joshi, D. G. Kanhere, and S. A. Blundell, Phys. Rev. B 67, 235413 (2003)] predict that Sn20 melts at around 1200K . We have performed calorimetry measurements on unsupported Sn18+ , Sn19+ , Sn20+ , and Sn21+ in an effort to test this prediction. We find that these tin clusters disappear well below their predicted melting temperature due to dissociation. Calorimetry measurements performed up to around 650K show some small features (which may be due to localized structural changes) but no clear melting transitions. Hence, tin clusters in this size regime do not melt—they sublime.

Breaux, Gary A.; Neal, Colleen M.; Cao, Baopeng; Jarrold, Martin F.

2005-02-01

378

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.

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

2009-01-01

379

Thermodynamics of Surfactants, Block Copolymers and Their Mixtures in Water: The Role of the Isothermal Calorimetry  

PubMed Central

The thermodynamics of conventional surfactants, block copolymers and their mixtures in water was described to the light of the enthalpy function. The two methodologies, i.e. the van’t Hoff approach and the isothermal calorimetry, used to determine the enthalpy of micellization of pure surfactants and block copolymers were described. The van’t Hoff method was critically discussed. The aqueous copolymer+surfactant mixtures were analyzed by means of the isothermal titration calorimetry and the enthalpy of transfer of the copolymer from the water to the aqueous surfactant solutions. Thermodynamic models were presented to show the procedure to extract straightforward molecular insights from the bulk properties.

De Lisi, Rosario; Milioto, Stefania; Muratore, Nicola

2009-01-01

380

The DREAM project—Towards the ultimate in calorimetry  

NASA Astrophysics Data System (ADS)

High-precision jet spectroscopy will be increasingly important in future high-energy accelerator experiments, particularly at a linear e+e- collider. The dual-readout technique makes it possible to meet and exceed the requirements on calorimeter performance in experiments at such a collider. The DREAM Collaboration is exploring the limits of the possibilities offered by this technique, by systematically eliminating the limiting factors, one after the other. Powerful tools in this context are the simultaneous measurement of scintillation light and Cherenkov light generated in the shower development process, and a detailed measurement of the time structure of the signals. In this talk, the latest results of this generic detector R&D project are presented. In particular, I report on the first tests of a hybrid dual-readout calorimeter system, in which a BGO crystal matrix served as the electromagnetic section.

Wigmans, Richard

2010-05-01

381

DTA/DSC studies of phase equilibria in binary mixtures of barium carbonate with alkali carbonates  

NASA Astrophysics Data System (ADS)

Phase diagrams for binary mixtures of BaCO3 with K2CO3, Na2CO3, or Li2CO3 have been prepared using data for melting enthalpies and temperatures obtained from differential thermal analysis experiments. The information will contribute to determining if BaCO3 is acceptable as a partial replacement for Li2CO3 in mixtures of these carbonates used as heat transfer and storage media in central solar receivers.

Mills, Roger E.; Coyle, R. Thomas

1987-07-01

382

Differential Scanning Calorimetry Study of the Reactivity of Carbon Anodes in Plastic Won Batteries  

Microsoft Academic Search

Chemical reactions taking place at elevated temperatures in a polymer-bonded lithiated carbon anode were studied by differential scanning calorimetry. The influences of parameters such as degree of intercalation, number of cycles, spe- cific surface area, and chemical nature of the binder were elucidated. It was clearly established that the first reaction tak- ing ate If lace at ca. 120-140 \\

F. Disma; T. Bowmer; A. S. Gozdz; G. Amatucci; URA CNRS

383

REVIEW ARTICLE: Investigating the thermodynamics and kinetics of thin film reactions by differential scanning calorimetry  

Microsoft Academic Search

In this paper we demonstrate the utility of differential scanning calorimetry for investigating the thermodynamics and kinetics of a broad range of thin film reactions. We begin by describing differential scanning calorimeters and the preparation of thin film samples. We then cite a number of examples that illustrate how enthalpies of crystallization, heats of formation and enthalpies of interfaces can

C. Michaelsen; K. Barmak; T. P. Weihs

1997-01-01

384

Cone calorimetry studies of polymer systems flame retarded by chemically bonded phosphorus  

Microsoft Academic Search

The combustion behaviour of polystyrene flame retarded by the incorporation of phosphorus-containing compounds has been studied by LOI and cone calorimetry. Both ‘reactive’ and ‘additive’ approaches to the incorporation of the phosphorus have been applied and assessed. The data obtained show that the reactive approach results in enhanced char formation during combustion due to a condensed phase mechanism. Flame retardation

D. Price; K. J. Bullett; L. K. Cunliffe; T. R. Hull; G. J. Milnes; J. R. Ebdon; B. J. Hunt; P. Joseph

2005-01-01

385

Differential scanning calorimetry: A potential tool for discrimination of olive oil commercial categories  

Microsoft Academic Search

Differential scanning calorimetry thermograms of five commercial categories of olive oils (extra virgin olive oil, olive oil, refined olive oil, olive-pomace oil and refined olive-pomace oil) were performed in both cooling and heating regimes. Overlapping transitions were resolved by deconvolution analysis and all thermal properties were related to major (triacylglycerols, total fatty acids) and minor (diacylglycerols, lipid oxidation products) chemical

Emma Chiavaro; Maria Teresa Rodriguez-Estrada; Carlo Barnaba; Elena Vittadini; Lorenzo Cerretani; Alessandra Bendini

2008-01-01

386

Energy Storage Capacity of Reversible Liquid Phase Diels-Alder Reactions as Determined by Drop Calorimetry.  

National Technical Information Service (NTIS)

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 f...

C. P. Chung

1983-01-01

387

Final Technical Report Ã?¢Ã?Â?Ã?Â? CMS FAST OPTICAL CALORIMETRY  

SciTech Connect

This is the final report of CMS FAST OPTICAL CALORIMETRY, a grant to Fairfield University for development, construction, installation and operation of the forward calorimeter on CMS, and for upgrades of the forward and endcap calorimeters for higher luminosity and radiation damage amelioration.

David R Winn

2012-07-12

388

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

389

Calorimetry Sample Exchange analysis of data report for October--December, 1988  

Microsoft Academic Search

The goals of the Calorimetry Sample Exchange Program are to: 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 PuOâ powder is

Lyons

1989-01-01

390

Anaerobic metabolism in the leech ( Hirudo medicinalis L.): direct and indirect calorimetry during severe hypoxia  

Microsoft Academic Search

Anaerobic metabolism in the limnic annelid Hirudo medicinalis L. was investigated by direct and indirect calorimetry. During long-term severe hypoxia, the rate of heat dissipation was reduced up to 13% of the aerobic rate. At the same time, the rate of ATP turnover was reduced to about 30% of the aerobic rate, indicating that metabolic depression is an important mechanism

H. Schmidt; A. Wichmann; I. Lamprecht; I. Zerbst-Boroffka

1996-01-01

391

Monolithic junction field-effect transistor charge preamplifier for calorimetry at high luminosity hadron colliders  

SciTech Connect

The outstanding noise and radiation hardness characteristics of epitaxial-channel junction field-effect transistors (JFET) suggest that a monolithic preamplifier based upon them may be able to meet the strict specifications for calorimetry at high luminosity colliders. Results obtained so far with a buried layer planar technology, among them an entire monolithic charge-sensitive preamplifier, are described.

Radeka, V.; Rescia, S. [Brookhaven National Lab., Upton, NY (United States); Rehn, L.A. [InterFET Corp., Garland, TX (United States); Manfredi, P.F.; Speziali, V. [Pavia Univ. (Italy). Dipt. di Elettronica]|[Istituto Nazionale di Fisica Nucleare, Milan (Italy)

1991-11-01

392

Thermal Denaturation of Whey Proteins in Mixtures with Caseins Studied by Differential Scanning Calorimetry  

Microsoft Academic Search

Thermal unfolding of whey proteins and whey protein-casein mixtures in sim- ulated milk ultrafiltrate was studied by differential scanning calorimetry. The re- sults are reported as transition enthalpy, temperature of peak maximum, and van't Hoff enthalpy related to the sharpness of transition. The results of earlier investiga- tions were reviewed. It is suggested that a large part of reported whey

Marie Paulsson; Petr Dejmek

1990-01-01

393

Temperature modulated differential scanning calorimetry (TMDSC) in the region of phase transitions. Part 1: theoretical considerations  

Microsoft Academic Search

For temperature modulated differential scanning calorimetry (TMDSC) a simple model, the low pass filter, is presented which allows to see and calculate the influence of heat transfer into the sample on magnitude and phase shift of the modulated part of the measured heat flow rate and the heat capacity determined from it. A formula is given which enables to correct

G. W. H. Höhne

1999-01-01

394

Comparison of differential scanning calorimetry, FTIR, and NMR to measurements of adsorbed polymers  

Microsoft Academic Search

Temperature modulated differential scanning calorimetry (TMDSC) measurements on samples with very small amounts of polymers adsorbed on silica particles have been contrasted with spectroscopic techniques (FTIR and NMR) on the same or similar systems. The results are consistent in that the hydrogen bonding of the polymers to surface silanols reduces the mobility of some of the adsorbed polymer segments and

Frank D. Blum; Piyawan Krisanangkura

2009-01-01

395

Applications of temperature modulated differential scanning calorimetry in freeze-drying process development  

Microsoft Academic Search

The purpose of the present study was to investigate the potential of Temperature Modulated Differential Scanning Calorimetry (TMDSC) as an analytical tool in freeze-drying process development. After developing an adequate calibration method, the frequency dependence of low temperature transitions in model solutions was probed in an effort to support physical interpretations of the events that are observed in concentrated solutions.

Shawn Allen Knopp

1999-01-01

396

From strong to fragile glass- forming systems: A temperature modulated differential scanning calorimetry investigation  

Microsoft Academic Search

The capacity of temperature modulated differential scanning calorimetry (TMDSC) technique to determine dynamical parameters is tested on several glass-formers of different fragility. We show that both the fragility index m and the stretching exponent ? deduced from TMDSC are consistent with results from other spectroscopic analyses. In particular, we are interested in the coherency and complementarity with the dielectric measurements.

L. Carpentier; S. Desprez; M. Descamps

2003-01-01

397

Comparative continuous-indirect-calorimetry study of two carbohydrates with different glycemic  

Microsoft Academic Search

Six healthy young men were studied by indirect calorimetry for 6 h after eating a meal composed of glucose or manioc starch (equivalent to 50 g dextrose). Blood was drawn every 30 mm for 6 h to measure plasma glucose, free fatty acid (FFA), and insulin concentrations. The glycemic index of the starch was 57%. Plasma insulin and glucose concentrations

Patrick Ritz; Michel Krempf; Denis Cloarec; Martine Champ; Bernard Charbonnel

398

An Improved Method for the Preparation of Feces for Bomb Calorimetry.  

National Technical Information Service (NTIS)

A freeze-drying method has been developed by which human feces can be prepared for the determination of total calories by bomb calorimetry. Weighed, homogenized fecal slurries are prefrozen and lyophilized to dryness by means of a freeze-drying apparatus....

H. G. Lovelady E. J. Stork

1966-01-01

399

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

400

Investigation of biomass pyrolysis by thermogravimetric analysis and differential scanning calorimetry  

Microsoft Academic Search

The influence of sample size on the pyrolysis of wheat straw and three types of cellulose has been investigated by simultaneous thermogravimetric analysis and differential scanning calorimetry. Samples between 2 and 20 mg were pyrolyzed to a maximum temperature of 600°C at a heating rate of 40°C min?1. It was found that sample size had a large effect on the

Mette Stenseng; Anker Jensen; Kim Dam-Johansen

2001-01-01

401

Subsite binding energies of an exo-polygalacturonase using isothermal titration calorimetry  

Technology Transfer Automated Retrieval System (TEKTRAN)

Thermodynamic parameters for binding of a series of galacturonic acid oligomers to an exo-polygalacturonase, RPG16 from Rhizopus oryzae, were determined by isothermal titration calorimetry. Binding of oligomers varying in chain length from two to five galacturonic acid residues is an exothermic proc...

402

LuAG:Ce fibers for high energy calorimetry  

SciTech Connect

The main objective of this contribution is to point out the potentialities of cerium doped LuAG single crystal as pixels and fibers. We first show that after optimization of growth conditions using Bridgman technology, this composition exhibits very good performances for scintillating applications (up to 26 000 photons/MeV). When grown with the micropulling down technology, fiber shapes can be obtained while the intrinsic performances are preserved. For the future high energy experiments requiring new detector concepts capable of delivering much richer informations about x- or gamma-ray energy deposition, unusual fiber shaped dense materials need to be developed. We demonstrate in this frame that cerium doped LuAG is a serious candidate for the next generation of ionizing radiation calorimeters.

Dujardin, C.; Mancini, C.; Amans, D.; Ledoux, G. [Universite Lyon 1, CNRS, UMR5620, Laboratoire de Physico-Chimie des Materiaux Luminescents, Universite de Lyon, F-69622 Villeurbanne Cedex (France); Abler, D.; Auffray, E.; Lecoq, P. [CERN, 1211 Geneva 23 (Switzerland); Perrodin, D. [Fibercryst, La Doua, Bat. Atrium, Bd Latarjet, F- 69616 Villeurbanne (France); Petrosyan, A.; Ovanesyan, K. L. [Laboratory of Crystal Growth of Luminescent Materials, Institute for Physical Research, Armenian National Academy of Science, 0203 Ashtarak-2 (Armenia)

2010-07-15

403

Specific features of absorption and DSC for the DEA-CuCl4 nanoparticles incorporated into the PMMA polymer matrices  

NASA Astrophysics Data System (ADS)

Diethylammonium tetrachlorcuprate NH2(C2H5)2CuCl4 (DEA-CuCl4) nanoparticles with sizes about 10 nm were synthesized and embedded into the PMMA polymer matrices. Using DSC temperature study a substantial influence of the polymer matrix on the phase transition temperatures was shown, reflecting a disturbing effect of principal 3d Cu 3p Cl metal ligand charge transfer bands. Dependence of the absorption spectra on the nanocrystallites (NC) concentration was studied. It was established that an increase of the NC content results in spectral shift of CuCl4 absorption bands. Explanation of this phenomenon has been suggested within a framework of first principle crystal field quantum chemical calculations.

Ozga, K.; Piasecki, M.; Tkaczyk, S.; Kapustianyk, B.; Bragiel, P.; Reshak, A. H.; Brik, M. G.; Kityk, I. V.

2008-08-01

404

Inclusion complexes of cypermethrin and permethrin with monochlorotriazinyl-beta-cyclodextrin: A combined spectroscopy, TG/DSC and DFT study.  

PubMed

The suitable size hydrophobic cavity and monochlorotriazinyl group as a reactive anchor make MCT-?-CD to be widely used in fabric finishing. In this paper, the inclusion complexes of monochlorotriazinyl-beta-cyclodextrin (MCT-?-CD) with cypermethrin (CYPERM) and permethrin (PERM) are synthesized and analyzed by TG/DSC, FT-IR and Raman spectroscopy. TG/DSC reveals that the decomposed temperatures of inclusion complexes are lower by 25-30°C than that of physical mixtures. DFT calculations in conjunction with FT-IR and Raman spectral analyses are used to study the structures of MCT-?-CD and their inclusion complexes. Four isomers of trisubstituted MCT-?-CD are designed and DFT calculations reveal that 1,3,5-trisubstituted MCT-?-CD has the lowest energy and can be considered as main component of MCT-?-CD. The ground-state geometries, vibrational wavenumbers, IR and Raman intensities of MCT-?-CD and their inclusion complexes were calculated at B3LYP/6-31G (d) level of theory. Upon examining the optimized geometry of inclusion complex, we find that the CYPERM and PERM are inserted into the toroid of MCT-?-CD from the larger opening. The band at 1646cm(-1) in IR and at 1668cm(-1) in Raman spectrum reveals that monochloroazinyl group of MCT-?-CD exists in ketone form but not in anion form. The noticeable IR and Raman shift of phenyl reveals that these two benzene rings of CYPERM and PERM stays inside the cavity of MCT-?-CD and has weak interaction with MCT-?-CD. This spectroscopy conclusion is consistent with theoretical predicted structure. PMID:24103228

Yao, Qi; You, Bin; Zhou, Shuli; Chen, Meng; Wang, Yujiao; Li, Wei

2013-09-18

405

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

406

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

407

PREFACE: XIII International Conference on Calorimetry in High Energy Physics (CALOR 2008)  

NASA Astrophysics Data System (ADS)

The XIII International Conference on Calorimetry in High Energy Physics was held in Pavia, Italy, 26-30 May 2008, picking up the baton from the 2006 Conference in Chicago. The Conference took place in the unique environment of the Theresian Room of the University Library. The attendees were surrounded by over 40 000 books of general interest and culture, and had the opportunity to see precious volumes written by such people as Galileo, Volta and Faraday. The Workshop brought together more than 120 participants, including senior scientists as well as young physicists, confirming the central and ever-growing role of calorimeters in modern particle physics. The development of these detectors, as stressed by Professor Klaus Pretzl in his lectio magistralis, has made it possible to explore new frontiers in physics, and the present scenario is no exception to this rule. With the LHC experiments almost completely installed and ready to take data, the Conference was an ideal chance to review the status of the different projects, whose development has been followed and discussed throughout the entire Calor series, and to show that they are capable of meeting the design specifications. Other highlights were the performance and physics results of calorimeters installed in currently operating experiments. In the session on astrophysics and neutrinos, the contributions confirmed the key role of calorimeters in this sector and demonstrated their growing application even beyond the field of accelerator physics. Considerable time was devoted to the state-of-the-art techniques in the design and operation of the detectors, while the session on simulation addressed the importance of a thorough understanding of the shower development to meet the demanding requirements of present experiments. Finally, on the R&D side, the particle flow and dual read-out concepts confronted the challenges issued by the next generation of experiments. This complex material was reviewed in 83 presentations, now reported in these proceedings, that were debated in stimulating and fruitful discussions. Outside of the Workshop, the participants were able to visit the historical Halls and Museum of the University, whose foundation dates back to the year 1361, and to enjoy a visit to the Certosa, a Carthusian monastery renowned for its exuberant architecture. Pavia welcomed the Conference participants by opening the doors of the Town Hall and offering a reception during which the Mayor's address underlined the importance of research and its applications in modern society. The successful organization and the smooth running of the Conference is due to many people and Institutions. We gratefully acknowledge the financial support of the Istituto Nazionale di Fisica Nucleare (INFN), the Department of Nuclear and Theoretical Physics and the University of Pavia, that made the Workshop possible, together with the contribution of our sponsors. The University also opened some rooms of the Chancellor's suite for the lunch and coffee breaks, and hosted the Conference Secretariat. We would like to express our deepest gratitude to the INFN and Department technical staff, who helped to prepare the Hall for the Conference and to provide computer services, and to the staff of the Theresian Library, who gave us access to the Room and organized a display of the many historical books from their vast and precious collections which are of interest to physicists. Above all, the success of the meeting is due to the participants who animated it, and in particular to the speakers for their dedicated work in preparing their excellent talks and in providing the write-ups, and to the conveners for their essential role in shaping an interesting and well balanced scientific program. Finally, we wish to thank the International Advisory Committee for their unfailing support and for offering us the opportunity to organize this Conference in Pavia. Michele Livan Chairman, Organizing Committee International Advisory Commitee M Danilov, ITEP Moscow M Diemoz, INFN Roma I A Ereditato, Bern F Fabbri, I

Livan, Michele

2009-07-01

408

Student learning of thermochemical concepts in the context of solution calorimetry  

NASA Astrophysics Data System (ADS)

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 J.; Meltzer, David E.

2003-07-01

409

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

410

Radiation damage study for silicon calorimetry: Summary of first year's activity  

SciTech Connect

In the first contract year of this activity at Carnegie-Mellon we have had two major objectives. These were to devise and test a non-intrusive means to measure the energy and spatial profiles of the neutrons generated in a hadronic cascade at high energy; and to study the calibration systematics of silicon diode detectors as a prelude to their evaluation for SSC calorimetry. These objectives have been carried out, as are described in this paper. In addition we have recoded the ORNL detector simulation program HETC to operate on a VAX and are working on the conversion of the low energy neutron transport program MORSE. These programs are used heavily at Oak Ridge (Gabriel and coworkers) for cascade studies. For silicon calorimetry one wants to have more control over the energy deposition routines, especially in MORSE. Unfortunately, MORSE is heavily-laden with machine code, and its conversion is going slowly. 11 refs., 5 figs.

Russ, J.S.

1988-01-01

411

Calorimetry Outside the Box: A New Window into the Plasma Proteome  

PubMed Central

Differential scanning calorimetry provides a new window into the plasma proteome. Plasma from normal individuals yields a characteristic, reproducible thermogram that appears to represent the weighted sum of denaturation profiles of the most abundant constituent plasma proteins. Plasma from diseased individuals yields dramatically different signature thermograms. Thermograms from individuals suffering from rheumatoid arthritis, systemic lupus, and Lyme disease were measured. Each disease appears to have a distinctive and characteristic thermogram. The difference in thermograms between normal and diseased individuals is not caused by radical changes in the concentrations of the most abundant plasma proteins but rather appears to result from interaction of as yet unknown biomarkers with the major plasma proteins. These results signal a novel use for calorimetry as a diagnostic tool.

Garbett, Nichola C.; Miller, James J.; Jenson, Alfred B.; Chaires, Jonathan B.

2008-01-01

412

Calorimetry outside the box: a new window into the plasma proteome.  

PubMed

Differential scanning calorimetry provides a new window into the plasma proteome. Plasma from normal individuals yields a characteristic, reproducible thermogram that appears to represent the weighted sum of denaturation profiles of the most abundant constituent plasma proteins. Plasma from diseased individuals yields dramatically different signature thermograms. Thermograms from individuals suffering from rheumatoid arthritis, systemic lupus, and Lyme disease were measured. Each disease appears to have a distinctive and characteristic thermogram. The difference in thermograms between normal and diseased individuals is not caused by radical changes in the concentrations of the most abundant plasma proteins but rather appears to result from interaction of as yet unknown biomarkers with the major plasma proteins. These results signal a novel use for calorimetry as a diagnostic tool. PMID:17951300

Garbett, Nichola C; Miller, James J; Jenson, Alfred B; Chaires, Jonathan B

2007-10-19

413

Calorimetry and respirometry in guinea pigs in hydrox and heliox at 10-60 atm  

Microsoft Academic Search

We used direct calorimetry and respirometry to measure the total rate of heat loss (QD) and of oxygen consumption ($$ \\\\mathop V\\\\limits^ \\\\bullet {\\\\rm O}_{\\\\rm 2} $$ ) in guinea pigs in 1-atm (0.1 MPa) air and at 10-60 atm in either heliox (98% He, 2% O2) or hydrox (98% H2, 2% O2). Our objective was to determine if the

Andreas Fahlman; Jaya A. Kaveeshwar; Peter Tikuisis; Susan R. Kayar

2000-01-01

414

Thermodynamic analysis of AuIn–Sb system using Oelsen calorimetry and predicting methods  

Microsoft Academic Search

The results of comparative thermodynamic analysis of AuIn–Sb section in ternary Au–In–Sb system are presented in this paper.\\u000a Investigation was carried out experimentally, using Oelsen calorimetry at the temperature 873 K and analytically, applying\\u000a different predicting methods––Toop and Muggianu in the temperature interval from 873 K to 1673 K. The values for integral\\u000a molar Gibbs excess energies and antimony activities have been determined

Lidija Gomidželovi?; Dragana Živkovi?

2009-01-01

415

Energy expenditure from minute-by-minute heart-rate recording: comparison with indirect calorimetry13  

Microsoft Academic Search

Total daily energy expenditure (TDEE) and energy expended in activity (EAC) were estimated by the minute-by-minute heart-rate method in 22 (16 men, 6 women) individually calibrated subjects and compared with values obtained by whole-body indirect calorimetry. Subjects followed four activity protocols during the 22 h in the calorimeter, no exercise (n = 6) and 2 (n = 5), 4 (n

GB Spurr; AM Prentice; PR Murgatroyd; GR Goldberg

416

Characterisation of Glass Transition of Durum Wheat Semolina using Modulated Differential Scanning Calorimetry  

Microsoft Academic Search

The glass transition of wheat durum semolina was characterised at different moisture contents using modulated differential scanning calorimetry. The total, reversing and non-reversing heat flows were quantified during heating, cooling and re-heating. An endothermic peak was observed on the non-reversing heat flow during first heating and was not greatly affected by changes in moisture content (below 20 g water\\/100 g

Bernard Cuq; Christèle Icard-Vernière

2001-01-01

417

Thermal analysis of failed-batch palm oil by differential scanning calorimetry  

Microsoft Academic Search

Thermal behavior of palm oil samples drawn from the batch crystallizers that failed during crystallization and of a control\\u000a oil that was drawn from a batch that produced good crystallization were analyzed by differential scanning calorimetry under\\u000a constant heating and cooling conditions. Four polymorphs—?’2, ?, ?’1, and ?1—were observed, and their temperatures were tabulated. A rapid and sudden surge of

Y. B. Che Man; P. Z. Swe

1995-01-01

418

Pathogenesis of obesity and diabetes mellitus: insights provided by indirect calorimetry in humans  

Microsoft Academic Search

Energy homeostasis is the balance between energy intake and energy expenditure. Assessment of energy intake is unreliable,\\u000a especially in obese individuals. On the contrary it is possible to assess energy expenditure by means of different techniques.\\u000a In this review, the contributions of indirect calorimetry to its assessment and to the comprehension of the pathogenic mechanisms\\u000a of obesity and diabetes mellitus

G. Perseghin

2001-01-01

419

Advanced forward calorimetry for the SSC and TeVatron collider  

Microsoft Academic Search

We describe a project to develop fast, radiation hardened forward calorimetry for the SSC and TeVatron collider. Detector technologies discussed are based on gas and warm liquid media. In particular, we present the design of an ultrasensitive hybrid charge preamplifier for liquid technology capable of operating at 0.1-1 GHz. The actual detector bandwidth will depend on the choice of detector

D. Dibitonto; P. M. van Peteghem; R. L. Geiger; P. M. McIntyre; Y. Pang; J. M. Thane; J. T. White; M. Atac

1989-01-01

420

A thermodynamic analysis of the Cal–Ad method with respect to gas–solid calorimetry  

Microsoft Academic Search

A recent article claims that the Cal–Ad method cannot discriminate multiple acid sites in the analysis of the interaction of pyridine (dilute pyridine in n-hexane) with HZSM-5. The Cal–Ad technique measures the enthalpy of a base-displacement reaction, while gas–solid calorimetry is a measure of an adduct formation between pyridine and the solid. A Born–Haber cycle with the appropriate values can

Charles Edwin Webster; John P. Osegovic; Brian J. Scott; Sílvia C. Dias

1999-01-01

421

Use of bomb calorimetry to assess recovery of waste industrial mineral oils through regeneration  

Microsoft Academic Search

This paper shows an application of bomb calorimetry used in the procedure of regeneration of waste industrial mineral oils.\\u000a Using the treatment here reported a recovery of nearly 50% of the used oils was achieved. Furthermore, the oils so recovered\\u000a contain concentrations of potentially contaminant elements far below the requirements of the European Union (EU). Generally\\u000a speaking, it can be

L. Núñez-Regueira; J. Rodríguez-Añón; J. Proupín-Castiñeiras; C. Labarta-Carreño

2002-01-01

422

31P NMR and isothermal titration calorimetry studies on polyoxomolybdates-catalyzed hydrolysis of ATP  

Microsoft Academic Search

ATP hydrolysis in the presence of polyoxomolybdates at pH levels of 6, 4, and 2 has been investigated with a help of high pressure liquid chromatography (HPLC) analyses, 31P- and 1H NMR measurements, and isothermal titration calorimetry (ITC). The polyoxomolybdates-induced ATP-hydrolysis proceeded satisfactorily in pH<6 media at 20°C with an optimum pH level of 4, while it was significantly depressed

Eri Ishikawa; Toshihiro Yamase

2006-01-01

423

Time-Resolved Photoacoustic Calorimetry: Probing the Energetics and Dynamics of Fast Chemical and Biochemical Reactions  

NASA Astrophysics Data System (ADS)

Time-resolved photoacoustic calorimetry is a new experimental technique that measures the dynamics of enthalpy changes on the time scale of nanoseconds to microseconds for reactions initiated by absorption of light. When the reaction is carried out in water, it is also possible to obtain the dynamics of the corresponding volume changes. This method has been applied to a variety of biochemical, organic, and organometallic reactions.

Peters, Kevin S.; Snyder, Gary J.

1988-08-01

424

Temperature-modulated Calorimetry of the Crystallization of Polymers Analyzed by Measurements and Model Calculations  

Microsoft Academic Search

The response of temperature-modulated differential scanning calorimetry (TMDSC) to irreversible crystallization of linear polymers was investigated by model calculations and compared to a number of measurements. Four different exotherms were added to a typical modulated, reversible heat-flow rate in order to simulate irreversible crystallization. It was found that the reversing heat-flow rate of the TMDSC in response to such irreversible

M. L. Di Lorenzo; B. Wunderlich

1999-01-01

425

Evaluation of heat capacity measurements by temperature-modulated differential scanning calorimetry  

Microsoft Academic Search

Temperature-modulated differential scanning calorimetry (TMDSC) is known to have the ability to measure heat capacity of materials\\u000a more accurately than the conventional differential scanning calorimeter. However, the accuracy of the measured heat capacity\\u000a displays significant dependence on various experimental parameters such as period of modulation (p), amplitude of modulation (a), geometry of sample (g), heating rate (r), etc. One of

R. Venkata Krishnan; Krishnan K. Nagarajan

2010-01-01

426

Novel quasi-isothermal method of measuring heat capacity in temperature modulated differential scanning calorimetry  

Microsoft Academic Search

In this paper, a novel quasi-isothermal method of measuring sample’s specific heat capacity in temperature modulated differential scanning calorimetry (TMDSC) has been studied. With the strict temperature variation rule of plate-like sample in TMDSC model, the expression of the sample’s surface temperature lag in quasi-isothermal state has been obtained. With this temperature lag rule, sample’s specific heat capacity and its

En-Yong Ding; Rong-Shi Cheng

2001-01-01

427

A description of the glass transition measured by temperature modulated differential scanning calorimetry  

Microsoft Academic Search

The temperature modulated differential scanning calorimetry (TMDSC) technique can be used for heat capacity spectroscopy\\u000a in the low frequency range. Measured property is the complex heat capacity C\\u000a *=C??iC?. The frequency dependent relaxation transition measured by TMDSC occurs in the temperature range of the thermal glass transition.\\u000a Thus, the non-equilibrium of the glassy state influences the TMDSC curves. An experimental

J. E. K. Schawe

1998-01-01

428

A Study of Temperature-modulated Differential Scanning Calorimetry with High-resolution Infrared Thermography  

Microsoft Academic Search

Temperature gradients within the sample and furnace in temperature-modulated differential scanning calorimetry (TMDSC) are\\u000a studied for a power-compensation calorimeter of the Perkin Elmer type. The temperature measurements were made with a high-speed,\\u000a high-resolution infrared camera. Differences between programmed and actual temperature amplitudes are determined as a function\\u000a of sample thickness for a sawtooth modulation with up to 48 K min?1

R. Androsch; M. Pyda; H. Wang; B. Wunderlich

2000-01-01

429

Standard enthalpies of combustion of five halogen-substituted 8-hydroxyquinolines by rotating-bomb calorimetry  

Microsoft Academic Search

The standard (p°= 0.1 MPa) molar enthalpies of formation of five crystalline halogen-substituted 8-hydroxyquinolines, at the temperatureT= 298.15 K, were derived from measurements of the standard molar enthalpies of combustion in oxygen by rotating-bomb calorimetry.Using literature values of their standard molar enthalpies of sublimation, the standard molar enthalpies of formation, atT= 298.15 K, of the gaseous compounds were derived. These

Manuel A. V. Ribeiro da Silva; Maria Lu??sa C. C. H. Ferrão; Adelina M. R. O. Alves da Silva

1995-01-01

430

Determination of the Enthalpies of Combustion for Selected Gasoline Constituents Using Bomb Calorimetry  

Microsoft Academic Search

The experimental enthalpies of combustion values of three gasoline constituents, as determined by bomb calorimetry, were compared to determine relative contributions to the overall combustion of gasoline. The three experimental species, pentane, 2-pentene (E) and methyl-tert-butyl ether, were selected upon the criteria that pentane is found in gasoline, while trans-2-pentene has to be supplemented to the gasoline mixture during petroleum

A. Getschman; A. Herrman

431

Standard molar enthalpy of formation of 4-iodobenzoic acid by static and rotating-bomb calorimetry  

Microsoft Academic Search

The standard (po= 0.1 MPa) molar enthalpy of combustion of 4-iodobenzoic acid, at T= 298.15 K, was measured by static-bomb and rotating-bomb calorimetry, from which the standard molar enthalpy of formation, in the crystalline state, was derived.The values obtained confirm that 4-iodobenzoic acid is a satisfactory test substance for combustion of organo-iodine compounds. Using a literature value for its standard

M. A. V. Ribeiro da Silva; M. L. C. C. H. Ferrão; I. M. S. Costa

1999-01-01

432

Heat Capacities and Thermal Properties of a Homogeneous Ethylene1-octene Copolymer by Adiabatic Calorimetry  

Microsoft Academic Search

Specific heat capacities of a homogeneous ethylene-1-octene copolymer were measured by adiabatic calorimetry in the temperature\\u000a range from 5 to 400 K (stepwise heating at averaged rates of approximately 1 to 34 K h–1, after cooling at rates in the range from 8 K h–1 to 4 K min–1). The glass transition takes place from roughly 205 to225 K and

P. J. van Ekeren; L. D. Ionescu; V. B. F. Mathot; J. C. van Miltenburg

2000-01-01

433

The hydration pressure between lipid bilayers. Comparison of measurements using x-ray diffraction and calorimetry.  

PubMed Central

The hydration pressure between dipalmitoyl phosphatidyl-N,N-dimethylethanolamine (DPPE-Me2) bilayers has been analyzed by both x-ray diffraction measurements of osmotically stressed liposomes and by differential scanning calorimetry. By the x-ray method, we obtain a magnitude (Po) and decay length (lambda) for the hydration pressure which are both quite similar to those found for bilayers of other zwitterionic lipids, such as phosphatidylcholines. That is, x-ray analysis of DPPE-Me2 in the gel phase gives lambda = 1.3 A, the same as that previously measured for the analogous gel phase lipid dipalmitoylphosphatidylcholine (DPPC), and Po = 3.9 x 10(9) dyn/cm2, which is in excellent agreement with the value of 3.6 x 10(9) dyn/cm2 calculated from the measured Volta potential of DPPE-Me2 monolayers in equilibrium with liposomes. These results indicate that the removal of one methyl group to convert DPPC to DPPE-Me2 does not markedly alter the range or magnitude of the hydration pressure. Calorimetry shows that the main gel to liquid-crystalline phase transition temperature of DPPE-Me2 is approximately constant for water contents ranging from 80 to 10 water molecules per lipid molecule, but increases monotonically with decreasing water content below 10 waters per lipid. A theoretical fit to these temperature vs. water content data predicts lambda = 6.7 A. The difference in observed values of lambda for x-ray and calorimetry measurements can be explained by effects on the thermograms of additional intra- and intermolecular interactions which occur at low water contents where apposing bilayers are in contact. We conclude that, although calorimetry provides important data on the energetics of bilayer hydration, it is difficult to obtain quantitative information on the hydration pressure from this technique.

Simon, S. A.; Fink, C. A.; Kenworthy, A. K.; McIntosh, T. J.

1991-01-01

434

Parametric analysis of the helium flow for the in-bed calorimetry of metal hydride bed  

Microsoft Academic Search

Korea has been developing several concepts of the metal hydride beds for the ITER storage & delivery system (SDS). A thin double-layered annulus metal hydride bed is under development. It consists of the thin and double layers of ZrCo which are confined by the cylinder-shaped SUS filter and the primary vessel wall. The helium channels for the in-bed calorimetry are

H.-G. Kang; S. Cho; M. H. Chang; S.-H. Yun; K. J. Jung; H. S. Chung; M. Shim; D. S. Koo; K. M. Song

2009-01-01

435

Study of inclusion complexes of cycloamylose with surfactants by isothermal titration calorimetry  

Microsoft Academic Search

Useful materials can be made from cycloamylose (CA) and the functional properties of CA could be improved by complexation with surfactants. Isothermal titration calorimetry (ITC) was used to investigate interactions between CA and surfactants in buffered solutions. Three surfactants with C12 non-polar tail groups and charged [anionic: sodium dodecyl sulfate (SDS); cationic: dodecyl trimethylammonium bromide (DTAB)] or non-charged headgroups [non-ionic:

Saehun Mun; Shin-Joung Rho; Yong-Ro Kim

2009-01-01

436

A study of the adsorption of thiophenic sulfur compounds using flow calorimetry  

Microsoft Academic Search

Selective adsorption of sulfur compounds from gasoline and diesel fuel has potential to produce ultra clean fuels for on-board fuel cell applications and also to meet the upcoming legislation for clean fuels. Removal of thiophenic sulfur compounds in a hexadecane solution using commercial zeolites, NaY, USY, HY and 13X, has been investigated by adsorption and flow calorimetry techniques. The S

Flora T. T. Ng; Ataur Rahman; Tomotsugu Ohasi; Ming Jiang

2005-01-01

437

FT-IR and DSC studies of poly(vinylidene chloride-co-acrylonitrile) complexed with LiBF4  

NASA Astrophysics Data System (ADS)

Poly(vinylidene chloride-co-acrylonitrile) (PVdC-co-AN) based solvent free electrolytes were prepared for different compositions of PVdC-co-AN and LiBF4 using solution casting technique. The ionic conductivity, thermal behavior, complexation and structure of polymer electrolytes have been investigated as a function of LiBF4 content at different weight ratios. DSC studies revealed that the glass transition temperature Tg decreases with the increase of salt concentration up to an optimum level. The change in the glass transition temperature (Tg) with respect to the LiBF4 concentration is reflected in the bulk resistance of the electrolytes and the sample containing 6 wt.% of LiBF4 exhibited minimum bulk resistance compared to other samples. FT-IR studies confirm the interaction of polymer and salt which is mainly between Li-cation and nitrogen atom of Ctbnd N group. The crystalline phase of polymer host is completely changed on the addition of Li salt.

Shanthi, M.; Mathew, Chithra M.; Ulaganathan, M.; Rajendran, S.

2013-05-01

438

Temperature-modulated calorimetry of the frequency dependence of the glass transition of poly(ethylene terephthalate) and .  

National Technical Information Service (NTIS)

Temperature-modulated differential scanning calorimetry, TMDSC, is new technique that permits to measure the apparent heat capacity vs modulation frequency. The method is briefly described and a quasi- isothermal measurement method is used to derive the k...

B. Wunderlich I. Okazaki

1997-01-01

439

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

440

DSC measurements on sharks  

Microsoft Academic Search

Sharks are commonly termed fish, even though they are only distantly related to the classical (bony) fish. What differentiates a shark from a bony fish? Sharks have a spinal column and are thus vertebrates. However, their skeleton is not made of bones, but of cartilage, and together with their nearest relatives the rays and the chimeras they form the class

Reinhard Schubring

2007-01-01

441

Characterization of polymer matrix and low melting point solder for anisotropic conductive film  

Microsoft Academic Search

The chemo-rheological mechanisms of a polymer matrix and a low melting point solder for an anisotropic conductive film (ACF) have been characterized. For the material characterization of the polymer matrix and solder, a differential scanning calorimetry (DSC) and a dynamic mechanical analyzer (DMA) experiments were conducted. The conversion and viscosity of the polymer matrix was observed by DSC and DMA,

Yong-Sung Eom; Ji-Won Baek; Jong-Tae Moon; Jae-Do Nam; Jong-Min Kim

2008-01-01

442

Chemical analysis of metal impurity distribution of zone-refined mercuric iodide by ICP-AES and DSC  

NASA Astrophysics Data System (ADS)

A mercuric iodide single crystal is being developed for X-ray and gamma-ray detector applications where high-purity starting material is required. Zone-refining processing has been proven to be an effective step in the purification of large amounts of mercuric iodide for crystal growth. In this study we used the Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) to identify and determine the distribution of impurity concentrations along the ampoule after zone-refining mercuric iodide. The results show that for Ag, Cu, Fe, Mg, Ca, Zn, Cr and Al, the zone-refining process does sweep the impurities to the last-to-freeze zone, due to an effective distribution coefficient, keff < 1. For Na, Ni, Cd, Mn and Pb the concentration gradient seems to be fairly independent of the position along the ingot. Differential Scanning Calorimetry was also employed to investigate the deviation from stoichiometry caused by the zone-refining process, and the results indicated that the first-to-freeze section is Hg-rich, and the middle section tends to become slightly Hg-rich, while the last-to-freeze section becomes I-rich.

Chen, K.-T.; Salary, L.; Burger, A.; Soria, E.; Antolak, A.; James, R. B.

443

Temperature-modulated DSC using higher harmonics of the Fourier transform 1 Authored by a contractor of the US Government under the contract No. DE-AC05-96OR22464. Accordingly, the US Government retains a non-exclusive, royalty-free license to publish, or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. 1  

Microsoft Academic Search

In this paper, experiments with temperature-modulated calorimetry are described in which use is made of multiple modulation frequencies for the evaluation of the heat capacity. The different harmonics of the Fourier series of the heat-flow rate and heating rate of a single sawtooth-modulation experiment were deconvoluted to extract data pertaining to different frequencies. In the normally employed temperature-modulated differential scanning

R Androsch; B Wunderlich

1999-01-01

444

Dimyristoylphosphatidylcholine/C16:0-ceramide binary liposomes studied by differential scanning calorimetry and wide- and small-angle x-ray scattering.  

PubMed Central

Ceramide has recently been established as a central messenger in the signaling cascades controlling cell behavior. Physicochemical studies have revealed a strong tendency of this lipid toward phase separation in mixtures with phosphatidylcholines. The thermal phase behavior and structure of fully hydrated binary membranes composed of dimyristoylphosphatidylcholine (DMPC) and N-palmitoyl-ceramide (C16:0-ceramide, up to a mole fraction X(cer) = 0.35) were resolved in further detail by high-sensitivity differential scanning calorimetry (DSC) and x-ray diffraction. Both methods reveal very strong hysteresis in the thermal phase behavior of ceramide-containing membranes. A partial phase diagram was constructed based on results from a combination of these two methods. DSC heating scans show that with increased X(cer) the pretransition temperature T(p) first increases, whereafter at X(cer) > 0.06 it can no longer be resolved. The main transition enthalpy DeltaH remains practically unaltered while its width increases significantly, and the upper phase boundary temperature of the mixture shifts to approximately 63 degrees C at X(cer) = 0.30. Upon cooling, profound phase separation is evident, and for all of the studied compositions there is an endotherm in the region close to the T(m) for DMPC. At X(cer) >/= 0.03 a second endotherm is evident at higher temperatures, starting at 32.1 degrees C and reaching 54.6 degrees C at X(cer) = 0.30. X-ray small-angle reflection heating scans reveal a lamellar phase within the temperature range of 15-60 degrees C, regardless of composition. The pretransition is observed up to X(cer) < 0.18, together with an increase in T(p). In the gel phase the lamellar repeat distance d increases from approximately 61 A at X(cer) = 0. 03, to 67 A at X(cer) = 0.35. In the fluid phase increasing X(cer) from 0.06 to 0.35 augments d from 61 A to 64 A. An L(beta')/L(alpha) (ripple/fluid) phase coexistence region is observed at high temperatures (from 31 to 56.5 degrees C) when X(cer) > 0.03. With cooling from temperatures above 50 degrees C we observe a slow increase in d as the coexistence region is entered. A sudden solidification into a metastable, modulated gel phase with high d values is observed for all compositions at approximately 24 degrees C. The anomalous swelling for up to X(cer) = 0.30 in the transition region is interpreted as an indication of bilayer softening and thermally reduced bending rigidity.

Holopainen, J M; Lemmich, J; Richter, F; Mouritsen, O G; Rapp, G; Kinnunen, P K

2000-01-01

445

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

2008-07-19

446

Standard enthalpies of formation of 2-thenoyltrifluoroacetone and monothio-2-thenoyltrifluoroacetone by rotating-bomb calorimetry  

Microsoft Academic Search

The standard (p°=0.1 MPa) molar enthalpies of formation of crystalline 1,1,1-trifluoro-4-(2-thienyl)-4-hydroxy-3-buten-2-one, HTTFA, and 1,1,1-trifluoro-4-(2-thienyl)-4-mercapto-3-buten-2-one, HTTFAS, atT=298.15 K were measured by rotating-bomb calorimetry and the standard molar enthalpies of sublimation atT=298.15 K were measured by microcalorimetry, with the following results: [Table] The results demonstrate an increase in stabilization energy of ?(38.7±5.0) kJ·mol?1in HTTFA compared with thiophene and that in these molecules,

M. A. V. Ribeiro da Silva; G. Pilcher

1997-01-01

447

Standard molar enthalpies of formation of some trichloroanilines by rotating-bomb calorimetry  

Microsoft Academic Search

The standard ( po= 0.1 MPa) molar enthalpies of formation ?fHmo, at the temperature 298.15 K, for crystalline 2,3,4-, 2,4,5-, 2,4,6- and 3,4,5-trichloroaniline were derived from the molar enthalpies of combustion ?cHmoin oxygen using rotating bomb combustion calorimetry. The reaction products were CO2(g), N2(g), and HCl · 600H2O(l). The standard molar enthalpies of sublimation ?crgHmoat T= 298.15 K were measured

Ana I. M. C. L. Ferreira

2002-01-01

448

Studying the curing of epoxyamine mixtures via dynamic light scattering and differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

The curing of epoxy oligomers with different structures and reactivity using an aliphatic amine curing agent was studied and quantitatively characterized by the methods of dynamic light scattering and differential scanning calorimetry. The presence of disperse phase in the initial reagents, as well as in the reacting systems is established. It is shown that the particles of the disperse phase are involved in the process of curing even in the early stages. By changing the width of the devitrification region, the change in the molecular homogeneity of epoxyamine systems during curing is estimated.

Senchikhin, I. N.; Zhavoronok, E. S.; Vysotskii, V. V.; Roldugin, V. I.

2013-01-01

449

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

450

The state of water in thermoresponsive poly(acryloyl- l-proline methyl ester) hydrogels observed by DSC and 1H-NMR relaxometry  

Microsoft Academic Search

Hydrogels that reversibly swell or shrink in water with decreasing or increasing temperature, respectively, were obtained by ? ray-induced polymerization of acryloyl-l-proline methyl ester in the presence of different amounts of a crosslinking agent. The role of water in the hydrated polymers was investigated by DSC and 1H-NMR relaxometry. From the curves of fusion of water determined by the former

Mario Carenza; Gianna Cojazzi; Barbara Bracci; Laura Lendinara; Lina Vitali; Michele Zincani; Masaru Yoshida; Ryoichi Katakai; Erzsebet Takacs; Olga Z. Higa; Flavia Martellini

1999-01-01

451

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

452

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

453

Temperature modulated DSC studies of melting and recrystallization in poly(ethylene-2,6-naphthalene dicarboxylate) (PEN) and blends with poly(ethylene terephthalate) (PET)  

Microsoft Academic Search

The thermal properties of amorphous and melt crystallized poly(ethylene-2,6-naphthalene dicarboxylate) (PEN) and its blends with poly(ethylene terephthalate) (PET) were investigated. Temperature modulated DSC (TMDSC) was used over a broad range of annealing times and temperatures. PEN under all moderate temperature crystallization conditions was found to exhibit secondary crystal melting in the low endotherm region, followed by melting of primary crystals

William G. Kampert; Bryan B. Sauer

2001-01-01

454

Separation of glass transition and melting in polyethylene\\/poly(butyl-methacrylate- co-methyl-methacrylate) interpenetrating polymer networks in TMDSC and DSC curves  

Microsoft Academic Search

Temperature modulated DSC (TMDSC) was tested concerning the possibility to separate the glass transition of the copolymer (BMA-co-MMA) component from the melting effect of the polyethylene (PE) in PE\\/BMA-co-MMA interpenetrating polymer networks prepared by in situ polymerisation. It was shown that a direct separation of both effects using TMDSC is not possible. The influence of the (excess) specific heat capacity

G. Pompe; U. Schulze; J. Hu; J. Pionteck; G. W. H. Höhne

1999-01-01

455

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

2010-03-11

456

REVIEW ARTICLE: Investigating the thermodynamics and kinetics of thin film reactions by differential scanning calorimetry  

NASA Astrophysics Data System (ADS)

In this paper we demonstrate the utility of differential scanning calorimetry for investigating the thermodynamics and kinetics of a broad range of thin film reactions. We begin by describing differential scanning calorimeters and the preparation of thin film samples. We then cite a number of examples that illustrate how enthalpies of crystallization, heats of formation and enthalpies of interfaces can be measured using layered thin films of Ni/Al, Cu/Zr and Zr/Al and homogeneous thin films of Co - Si, Nb - Cu, Cr - Cu and Ge - Sn. Following these examples of thermodynamic measurements, we show how kinetic parameters of nucleation, growth and coarsening can also be determined from differential scanning calorimetry traces using layered thin films of Ni/Al, Ti/Al and Nb/Al and homogenous thin films of Co - Si and Ge - Sn. The thermodynamic and kinetic investigations highlighted in these examples demonstrate that one can characterize phase transformations that are relevant to commercial applications and scientific studies both of thin films and of bulk materials.

Michaelsen, C.; Barmak, K.; Weihs, T. P.

1997-12-01

457

Investigation of ligand binding to the multidrug resistance protein EmrE by isothermal titration calorimetry.  

PubMed

Escherichia coli multidrug resistance protein E (EmrE) is an integral membrane protein spanning the inner membrane of Escherichia coli that is responsible for this organism's resistance to a variety of lipophilic cations such as quaternary ammonium compounds (QACs) and interchelating dyes. EmrE is a 12-kDa protein of four transmembrane helices considered to be functional as a multimer. It is an efflux transporter that can bind and transport cytoplasmic QACs into the periplasm using the energy of the proton gradient across the inner membrane. Isothermal titration calorimetry provides information about the stoichiometry and thermodynamic properties of protein-ligand interactions, and can be used to monitor the binding of QACs to EmrE in different membrane mimetic environments. In this study the ligand binding to EmrE solubilized in dodecyl maltoside, sodium dodecyl sulfate and reconstituted into small unilamellar vesicles is examined by isothermal titration calorimetry. The binding stoichiometry of EmrE to drug was found to be 1:1, demonstrating that oligomerization of EmrE is not necessary for binding to drug. The binding of EmrE to drug was observed with the dissociation constant (K(D)) in the micromolar range for each of the drugs in any of the membrane mimetic environments. Thermodynamic properties demonstrated this interaction to be enthalpy-driven with similar enthalpies of 8-12 kcal/mol for each of the drugs in any of the membrane mimetics. PMID:15501941

Sikora, Curtis W; Turner, Raymond J

2004-10-22

458

Differential scanning calorimetry: a potential tool for discrimination of olive oil commercial categories.  

PubMed

Differential scanning calorimetry thermograms of five commercial categories of olive oils (extra virgin olive oil, olive oil, refined olive oil, olive-pomace oil and refined olive-pomace oil) were performed in both cooling and heating regimes. Overlapping transitions were resolved by deconvolution analysis and all thermal properties were related to major (triacylglycerols, total fatty acids) and minor (diacylglycerols, lipid oxidation products) chemical components. All oils showed two well distinguishable exothermic events upon cooling. Crystallization enthalpies were significantly lower in olive oils due to a more ordered crystal structure, which may be related to the higher triolein content. Pomace oils exhibited a significantly higher crystallization onset temperature and a larger transition range, possibly associated to the higher amount of diacylglycerols. Heating thermograms were more complex: all oils exhibited complex exo- and endothermic transitions that could differentiate samples especially with respect to the highest temperature endotherm. These preliminary results suggest that both cooling and heating thermograms obtained by means of differential scanning calorimetry may be useful for discriminating among olive oils of different commercial categories. PMID:18724997

Chiavaro, Emma; Rodriguez-Estrada, Maria Teresa; Barnaba, Carlo; Vittadini, Elena; Cerretani, Lorenzo; Bendini, Alessandra

2008-07-29

459

Anaerobic metabolism in the leech (Hirudo medicinalis L.): direct and indirect calorimetry during severe hypoxia.  

PubMed

Anaerobic metabolism in the limnic annelid Hirudo medicinalis L. was investigated by direct and indirect calorimetry. During long-term severe hypoxia, the rate of heat dissipation was reduced up to 13% of the aerobic rate. At the same time, the rate of ATP turnover was reduced to about 30% of the aerobic rate, indicating that metabolic depression is an important mechanism to ensure survival of the leech during environmental anaerobiosis. Heat dissipation during hypoxia was monitored under two experimental conditions, favouring either concomitant hypocapnia (continuous N2 bubbling) or hypercapnia (self-induced hypoxia). The reduction in heat dissipation during hypocapnic hypoxia was less pronounced than during hypercapnic hypoxia, indicating that the different experimental conditions may influence anaerobic metabolism and the extent of metabolic depression. Biochemical analysis of known anaerobic substrates and endproducts provided the basis for indirect calorimetry during self-induced hypoxia. From changes in metabolites, the expected heat dissipation was calculated for initial (0-8 ,h) and long-term severe hypoxia (8-72 h). During the initial period, the calculated heat dissipation fully accounted for direct calorimetric determination. During long-term hypoxia, only 71% of the measured heat production could be explained from biochemical analysis of metabolites. Therefore, an additional unknown endproduct cannot be excluded, especially when anaerobic ammonia production and analysis of the carbohydrate balance are considered. PMID:8765666

Schmidt, H; Wichmann, A; Lamprecht, I; Zerbst-Boroffka, I

1996-01-01

460

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

461

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

462

Enthalpies of formation of borides of iron, cobalt, and nickel by solution calorimetry in liquid copper  

Microsoft Academic Search

The enthalpies of formation at 1385 ?2 K of the following crystalline borides have been determined by high temperature solution\\u000a calorimetry using liquid copper as the calorimetric solvent. Fe2B-67.87 ?8.05 kJ mol?1, Co2B -58.1 ?7.0 kJ mol?1, Ni2B -67.66 ?4.12 kJ ml?1, FeB-64.63 ?4.34 kJ mol?1, CoB -69.52 ?6.0 kJ mol?1, and NiB -40.2 ?3.77 kJ mol?1. The enthalpy of

Seichi Sato; O. J. Kleppa

1982-01-01

463

Direct Measurement of Glyconanoparticles and Lectin Interactions by Isothermal Titration Calorimetry  

PubMed Central

Glyconanomaterials have shown high potential in applications including bioanalysis and nanomedicine. Here, a quantitative analytical technique, based on isothermal titration calorimetry, was developed to characterize the interactions between glyconanoparticles and lectins. By titrating lectins into the glyconanoparticle solution, the apparent dissociation constant, thermodynamic parameters, and the number of binding sites were derived simultaneously. For the glyconanoparticles-lectin binding pairs investigated, a 3–5 orders of magnitude affinity enhancement over the free ligand-lectin interactions was observed which can be attributed to the multivalent ligand presentation on the nanoparticles. The impact of ligand density was also studied, and results showed that the affinity increased with the number of glycans on the nanoparticle.

Wang, Xin; Matei, Elena; Gronenborn, Angela M.; Ramstrom, Olof; Yan, Mingdi

2012-01-01

464

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

465

Probing differential Ag+-nucleobase interactions with isothermal titration calorimetry (ITC): Towards patterned DNA metallization  

NASA Astrophysics Data System (ADS)

DNA has been successfully used as a scaffold for the fabrication of metallic nanowires, primarily based on the electrostatic complexation and reduction of the metal cations on the negatively charged sugar-phosphate backbone. Here, we probe the differential binding affinities of nucleobases for silver ions using sensitive isothermal titration calorimetry (ITC) measurements of the reaction enthalpies, which go in order: C > G > A >= T. Using the disparity between the interaction of cytosine (strong binding) and thymine (weak binding) with silver ions, we have successfully generated silver nanoparticle doublets and triplets on custom-made oligonucleotides, C30-T40-C30 and C20-T20-C20-T20-C20, respectively. Thus, a new and simple method of generating metallized DNA wires is presented, based entirely on the nucleotide sequence of DNA. The concept could be extended to other cations and complex DNA sequences in order to achieve intricately patterned DNA constructs.

Shukla, Sourabh; Sastry, Murali

2009-09-01

466

Determining the colloidal behavior of ionically cross-linked polyelectrolytes with isothermal titration calorimetry.  

PubMed

Mixtures of polyelectrolytes and multivalent counterions can self-assemble into colloidal complexes. These complexes attract widespread interest in applications such as medicine, household product formulations, and separation processes. To facilitate the development of these colloidal dispersions, we examined isothermal titration calorimetry (ITC) as an automated screening tool for identifying the polymer and multivalent counterion compositions that (1) form ionically cross-linked colloidal complexes and (2) lead to their rapid coagulation (and macroscopic phase separation). By studying various polyelectrolyte/multivalent counterion mixtures, we have identified and generalized the features in the ITC data that indicate colloidal complex formation and coagulation. The limitations of this calorimetric screening method were also elucidated. These analyses suggest that ITC can be effective for screening the short-term colloidal behavior of polyelectrolyte/multivalent counterion mixtures but are unreliable in revealing their long-term (equilibrium) properties. PMID:23856000

Huang, Yan; Lapitsky, Yakov

2013-08-02

467

Inhibition study of adenosine deaminase by caffeine using spectroscopy and isothermal titration calorimetry.  

PubMed

Kinetic and thermodynamic studies were made on the effect of caffeine on the activity of adenosine deaminase in 50 mM sodium phosphate buffer, pH 7.5, using UV spectrophotometry and isothermal titration calorimetry (ITC). An uncompetitive inhibition was observed for caffeine. A graphical fitting method was used for determination of binding constant and enthalpy of inhibitor binding by using isothermal titration microcalorimetry data. The dissociation-binding constant is equal to 350 microM by the microcalorimetry method, which agrees well with the value of 342 microM for the inhibition constant that was obtained from the spectroscopy method. Positive dependence of caffeine binding on temperature indicates a hydrophobic interaction. PMID:14515165

Saboury, A A; Divsalar, A; Ataie, G; Amanlou, M; Moosavi-Movahedi, A A; Hakimelahi, G H

2003-01-01

468

A product inhibition study on adenosine deaminase by spectroscopy and calorimetry.  

PubMed

Kinetic and thermodynamic studies have been made on the effect of the inosine product on the activity of adenosine deaminase in a 50 mM sodium phosphate buffer, pH 7.5, at 27 degrees C using UV spectrophotometry and isothermal titration calorimetry (ITC). A competitive inhibition was observed for inosine as a product of the enzymatic reaction. A graphical-fitting method was used for determination of the binding constant and enthalpy of inhibitor binding by using isothermal titration microcalorimetry data. The dissociation-binding constant is equal to 140 microM by the microcalorimetry method, which agrees well with the value of 143 microM for the inhibition constant that was obtained from the spectroscopy method PMID:12297022

Saboury, Ali Akbar; Divsalar, Adeleh; Jafari, Ghasem Ataie; Moosavi-Movahedi, Ali Akbar; Housaindokht, Mohammad Reza; Hakimelahi, Gholam Hosain

2002-05-31

469

Binding of chrysoidine to catalase: Spectroscopy, isothermal titration calorimetry and molecular docking studies.  

PubMed

Chrysoidine is an industrial azo dye and the presence of chrysoidine in water and food has become an environmental concern due to its negative effects on human beings. In this work, the interactions between chrysoidine and bovine liver catalase (BLC) were explored. Obvious loss in catalytic activity was observed after incubation of BLC with chrysoidine, and the inhibition effect of BLC was found to be of the non-competitive type. No profound conformational change of BLC occurs in the presence of chrysoidine as revealed by UV-vis absorption, circular dichroism and fluorescence spectroscopy studies. Isothermal titration calorimetry results indicate that catalase has two sets of binding sites for chrysoidine. Further, molecular docking simulations show that chrysoidine is located within the bottleneck in the main channel of the substrate to the active site of BLC, which explain the activity inhibition of BLC by chrysoidine. PMID:24001681

Yang, Bingjun; Hao, Fang; Li, Jiarong; Chen, Dongliang; Liu, Rutao

2013-08-15

470

Standard molar enthalpy of formation of monothiodibenzoylmethane by rotating-bomb calorimetry  

Microsoft Academic Search

The standard (p?=0.1 MPa) molar enthalpies of formation of crystalline thianthrene and monothiodibenzoylmethane, HDBMS, at T=298.15 K were measured by rotating-bomb calorimetry and the standard molar enthalpies of sublimation at T=298.15 K of dibenzoylmethane (HDBMO) and monothiodibenzoylmethane (HDBMS) were measured by microcalorimetry.?cUm?(cr)\\/(kJ·mol?1)?fHm?(cr)\\/(kJ·mol?1)?crgHm?\\/(kJ·mol?1)Thianthrene– 7239.1±2.5182.1±3.1HDBMS– 8203.7±2.0– 6.0±2.8125.5±4.9HDBMO113.3±4.8From the present results it could be shown that, in these molecules, the intramolecular hydrogen bond

Manuel A. V. Ribeiro da Silva; Lu??s M. N. B. F. Santos

2004-01-01

471

An investigation of student thinking regarding calorimetry, entropy, and the second law of thermodynamics  

NSDL National Science Digital Library

This thesis constitutes an investigation into student understanding of concepts in thermal physics in an introductory calculus-based university physics course. Nearly 90% of students enrolled in the course had previous exposure to thermodynamics concepts in chemistry and/or high-school physics courses. The two major thrusts of this work are (1) an exploration of student approaches to solving calorimetry problems involving two substances with differing specific heats, and (2) a careful probing of student ideas regarding certain aspects of entropy and the second law of thermodynamics. We present extensive free-response, interview, and multiple-choice data regarding students' ideas, collected both before and after instruction from a diverse set of course semesters and instructors. For topics in calorimetry, we found via interviews that students frequently get confused by, or tend to overlook, the detailed proportional reasoning or algebraic procedures that could lead to correct solutions. Instead, students often proceed with semi-intuitive reasoning that at times may be productive, but more often leads to inconsistencies and non-uniform conceptual understanding. Our investigation of student thinking regarding entropy suggests that prior to instruction, students have consistent and distinct patterns of incorrect or incomplete responses that often persist despite deliberate and focused efforts by the instructor. With modified instruction based on research-based materials, significant learning gains were observed on certain key concepts, e.g., that the entropy of the universe increases for all non-ideal processes. The methodology for our work is described, the data are discussed and analyzed, and a description is given of goals for future work in this area.

Christensen, Warren M.

2013-02-13

472

The standard molar enthalpies of formation of 5,10,15,20-tetraphenylporphine and 5,10,15,20-tetrakis(4-methoxyphenyl)porphine by oxygen bomb combustion calorimetry  

Microsoft Academic Search

The standard massic energies of combustion ?cuoatT=298.15K were determined from combustion calorimetry experiments for solid 5,10,15,20-tetraphenylporphine (TPP, Chemical Abstracts registry number 917-23-7) and 5,10,15,20-tetrakis (4-methoxyphenyl) porphine (TMPP, Chemical Abstracts registry number 22112-78-3), leading to the following results: [table] where ?cUmo, ?cHmo, and ?fHmodenote the standard molar energy of combustion, standard molar enthalpy of combustion, and standard molar enthalpy of formation,

R. Patiño; L. A. Torres; M. Campos

1999-01-01

473

Validation and recovery rates of an indirect calorimetry headbox system used to measure heat production of cattle  

Technology Transfer Automated Retrieval System (TEKTRAN)

A headbox system was constructed at the University of Nebraska-Lincoln to determine heat production from dairy cattle using indirect calorimetry. The system was designed for use in a tie-stall barn to allow the animal to be comfortable and was mounted on wheels to transport between animals between s...

474

Quantitative studies on the zirconium - potassium perchlorate - nitrocellulose pyrotechnic system using differential scanning calorimetry and chemical analysis  

Microsoft Academic Search

Differential scanning calorimetry and chemical analysis, using ion specific electrodes, have been used to follow quantitatively the solid state reaction in the region of 400°C, between zirconium and potassium perchlorate in the presence of nitrocellulose. Comparison of the amount of potassium chloride formed in the reaction with the amount of perchlorate reacted has shown that the solid state reaction may

B. Berger; E. L. Charsley; J. J. Rooney; S. B. Warrington

1995-01-01

475

Temperature-modulated calorimetry of the frequency dependence of the glass transition of poly(ethylene terephthalate) and  

Microsoft Academic Search

Temperature-modulated differential scanning calorimetry, TMDSC, is new technique that permits to measure the apparent heat capacity vs modulation frequency. The method is briefly described and a quasi- isothermal measurement method is used to derive the kinetic parameters for PET and PS. A first-order kinetics expression was used to describe the approach to equilibrium and point out the limits caused by

B. Wunderlich; I. Okazaki

1997-01-01

476

Temperature modulated differential scanning calorimetry: on system linearity and the effect of kinetic events on the observed sample specific heat  

Microsoft Academic Search

In this paper, the effect of system linearity and kinetic events on heat capacity measurement by temperature modulated differential scanning calorimetry (TMDSC) is analyzed based on the thermal conduction differential equations that have been linearized assuming small kinetic perturbations. Numerical simulation of a first order reaction is used to demonstrate the importance of system linearity and the selection of experimental

S. X Xu; Y Li; Y. P Feng

2000-01-01

477

Tetramethylthiuram monosulfide and tetramethylthiuram disulfide: heats of formation by rotating-bomb calorimetry; the SS thermochemical bond energy  

Microsoft Academic Search

The heats of combustion and formation were determined for tetramethylthiuram monosulfide (bis-(dimethylthiocarbamoyl) sulfide) and tetramethylthiuram disulfide (bis-(dimethylthiocarbamoyl) disulfide). The S-S thermochemical bond energy in tetramethylthiuram disulfide was shown to be about the same as in normal alkane disulfides and in Sâ. Rotating-bomb combustion calorimetry was found satisfactory for compounds that contain both sulfur and nitrogen.

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

1961-01-01

478

Sample Preparation Techniques for Determination of Fish Energy Density via Bomb Calorimetry: An Evaluation Using Largemouth Bass  

Microsoft Academic Search

We evaluated three homogenization and subsampling techniques for preparing fish tissue samples for bomb calorimetry to identify differences in efficiency for estimating fish energy density. We compared (1) drying the whole fish and homogenizing the dried fish tissue, (2) homogenization prior to drying and then drying the subsample of fish tissue, and (3) homogenization after autoclaving to soften the hard

David C. Glover; Dennis R. DeVries; Russell A. Wright; Donald A. Davis

2010-01-01