WorldWideScience

Sample records for calorimetry

  1. Calorimetry

    International Nuclear Information System (INIS)

    An overall review of properties of various types of calorimeters is given, with special attention given to the challenges of high luminosity and high energy. The calorimeters described include continuous calorimeters, scintillation sampling calorimetry, gas sampling calorimetry, and liquid ionization calorimeters. Next explored are some limiting factors involved in experiments at high luminosities (or at high energies), and some examples are offered of detectors capable of operating at the highest luminosities (energies). Specific areas where substantial research and development work is needed are itemized

  2. Hadron Calorimetry

    International Nuclear Information System (INIS)

    Hadron calorimetry has been a rapidly developing field in the past few decades. Perhaps not too far in the future, a realistic calorimeter will be capable of measuring the energies of all the fundamental particles with ∼1% precision. Currently, calorimeters with unprecedented complexity attest to the knowledge and experience that have been accumulated in high energy physics. In this review, we touch on fundamental concepts and explain new developments that we expect to be important in the future. In addition to describing applications in accelerator-based high energy physics, we briefly mention the use of hadron calorimeters in other fields.

  3. Electromagnetic calorimetry

    International Nuclear Information System (INIS)

    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.

  4. Quantum Calorimetry

    Science.gov (United States)

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

    1999-01-01

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

  5. Tritium calorimetry

    International Nuclear Information System (INIS)

    Complete text of publication follows. Future deuterium-tritium fusion experiments (like ITER) will use large amount of tritium. Therefore, it is very important to develop better tritium accountancy methods. Tritium calorimetry is used to measure the heat produced by the beta-decay of tritium. If we consider that all the decay energy is converted into thermal heat, we can calculate the tritium activity and mass from calorimetric measurements. The advantages of calorimetry are that it measures absolute activity, and the physical or chemical composition of the sample is not relevant. For example, tritiated structural components can only be measured in a non-destructive way with calorimeters. Disadvantages are: long measurement time for large sample volumes, and offline sampling. The accepted conversion factor is 0.324W/g ± 0.3%. I have started participation from ATOMKI in an EFDA-GOT program, called TRI-TOFFY (TRITium fOr Fusion Fuel cYcle), in 2010. I have spent 8 months at Tritium Laboratory Karlsruhe (TLK), Germany in 2011, and 9 months in 2012. TLK is a semi-industrial scale facility for processing tritium, the radioactive hydrogen isotope. The main tasks of TLK are fusion research (ITER) and neutrino physics (KATRIN), but also EU projects. The present site inventory is ∼ 25 g T2 (8914 TBq). There are four calorimeters are used for tritium analytics at TLK. My main work was to carry out upgrade on these devices, to deploy new modern control and data acquisition (DAQ) software, and to partly change their hardware. I worked on three calorimeters at the laboratory. The ANTECH-351 is a commercial 20 years old calorimeter. It is a power compensation type isothermal calorimeter. Useful sample volume is 1.2 dm3. This is not a sensitive device (power range is 1 mW - 5 W), mainly used for tritium shipment (from Canadian CANDU reactors) validation, but can measure tritium samples very fast: less than 8 hours. The IGC-V0.5 is a custom made heat flow calorimeter, using a

  6. Dynamic Calorimetry for Students

    Science.gov (United States)

    Kraftmakher, Yaakov

    2007-01-01

    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…

  7. Theory of calorimetry

    CERN Document Server

    Zielenkiewicz, Wojciech

    2004-01-01

    The purpose of this book is to give a comprehensive description of the theoretical fundamentals of calorimetry. The considerations are based on the relations deduced from the laws and general equations of heat exchange theory and steering theory.

  8. Calorimetry for the SSC

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-01-01

    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.

  9. Calorimetry for the SSC

    International Nuclear Information System (INIS)

    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

  10. Scintillator materials for calorimetry

    International Nuclear Information System (INIS)

    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

  11. Calorimetry at the SSC

    International Nuclear Information System (INIS)

    The state of the art, and our present understanding of the basic limitations in hadron calorimetry, are briefly described. The various options for SSC calorimeters are discussed, and the R and D needed for the ones that look most promising is outlined. 13 refs.; 8 figs

  12. Scintillating-fibre calorimetry

    International Nuclear Information System (INIS)

    In the past decade, calorimetry based on scintillating plastic fibres as active elements was developed from a conceptual idea to a mature detector technology, which is nowadays widely applied in particle physics experiments. This development and the performance characteristics of representative calorimeters, both for the detection of electromagnetic and hadronic showers, are reviewed. We also discuss new information on shower development processes in dense matter and its application to calorimetric principles that has emerged from some very thorough studies that were performed in the framework of this development. (orig.)

  13. Dual-readout Calorimetry

    CERN Document Server

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

    2013-01-01

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

  14. Advances in hadron calorimetry

    International Nuclear Information System (INIS)

    This article concentrates on the recent improvements in our understanding of the fundamental aspects of hadron calorimetry: How do these devices work, what are the fundamental limitations to their performance, and how does the calorimeter performance relate to the needs of current and future experiments? The article is restricted to hadron calorimeter applications in accelerator-based experiments. Historically, the first large-scale detectors of this type were used in cosmic-ray experiments. They have found a wide application in underground experiments looking for nucleon decay, cosmic neutrinos, etc. In these experiments, the calorimeter is not only a detector but also a target and (for nucleon decay) a source. Therefore, the total instrumented mass is a very important parameter. Because of the completely different boundary conditions (low event rates, low energies, extremely rare processes), the emphasis in the development of these detectors has been on cheap, reliable technology with high signal-to-background separation capability

  15. Modern calorimetry: going beyond tradition

    OpenAIRE

    Jeong, Y. H.

    2001-01-01

    Calorimetry has been a traditional tool for obtaining invaluable thermodynamic information of matter, the free energy. We describe recent efforts to go beyond this traditional calorimetry: After introducing dynamic heat capacity, we present the various experimental methods to measure it. Applications and future prospects are also given.

  16. Combustion calorimetry experimental chemical thermodynamics

    CERN Document Server

    Sunner, Stig

    1979-01-01

    Combustion Calorimetry deals with expertise knowledge concerning the calorimetry of combustion reactions of an element or compound. After defining the use of units and physical constants, the book discusses the basic principles of combustion calorimetry and the various instruments and calorimeters used in the experiments to measure operations concerning temperatures and its time variations. One paper discusses the theory and design criteria of combustion calorimeter calibration. Another paper discusses the results obtained from a combustion calorimeter after it has measured the energy or entha

  17. Contactless Calorimetry for Levitated Samples

    Science.gov (United States)

    Lee, M. C.; Dokko, W.

    1986-01-01

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

  18. Calorimetry at industrial electron accelerators

    DEFF Research Database (Denmark)

    Miller, Arne; Kovacs, A.

    Calorimetry is a convenient way to measure doses at industrial electron accelerators, where high absorbed doses (1-100 kGy) are delivered at dose rates of 102-105 Gy s-1 or even higher. Water calorimeters have been used for this purpose for several years, but recently other materials such as...

  19. Calorimetry at industrial electron accelerators

    DEFF Research Database (Denmark)

    Miller, Arne; Kovacs, A.

    1985-01-01

    Calorimetry is a convenient way to measure doses at industrial electron accelerators, where high absorbed doses (1-100 kGy) are delivered at dose rates of 102-105 Gy s-1 or even higher. Water calorimeters have been used for this purpose for several years, but recently other materials such as...

  20. Development of Particle Flow Calorimetry

    OpenAIRE

    Repond, Jose

    2011-01-01

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

  1. Isothermal Titration Calorimetry of RNA

    OpenAIRE

    Salim, Nilshad N.; Feig, Andrew L.

    2008-01-01

    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, ΔG, ΔH, ΔS and reaction stoichiometry (n). Repeating the experiment at different temperatures allows determination of the heat capacity change (ΔCP) of the interaction. Modern calorimeters are sensitive enough to probe even weak biological interactions...

  2. Differential scanning calorimetry of coal

    Science.gov (United States)

    Gold, P. I.

    1978-01-01

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

  3. Calorimetry of non-reacting systems

    CERN Document Server

    McCullough, John P

    2013-01-01

    Experimental Thermodynamics, Volume 1: Calorimetry of Non-Reacting Systems covers the heat capacity determinations for chemical substances in the solid, liquid, solution, and vapor states, at temperatures ranging from near the absolute zero to the highest at which calorimetry is feasible.This book is divided into 14 chapters. The first four chapters provide background information and general principles applicable to all types of calorimetry of non-reacting systems. The remaining 10 chapters deal with specific types of calorimetry. Most of the types of calorimetry treated are developed over a c

  4. Water calorimetry: The heat defect

    International Nuclear Information System (INIS)

    Domen developed a sealed water calorimeter at NIST to measure absorbed dose to water from ionizing radiation. This calorimeter exhibited anomalous behavior using water saturated with gas mixtures of H2O2. Using computer simulations of the radiolysis of water, the authors show that the observed behavior can be explained if, in the gas mixtures, the amount-of-substance of H2 and of O2 differed significantly from 50%. The authors also report the results of simulations for other dilute aqueous solutions that are used for water calorimetry--pure water, air-saturated water, and H2-saturated water. The production of H2O2 was measured for these aqueous solutions and compared to simulations. The results indicate that water saturated with a gas mixture containing an amount-of-substance of H2 of 50% and of O2 of 50% is suitable for water calorimetry if the water is stirred and is in contact with a gas space of similar volume. H2-saturated water does not require a gas space but O2 contamination must be guarded against. The lack of a scavenger for OH radicals in pure water means that, depending on the water purity, some pure water might require a large priming dose to remove reactive impurities. The experimental and theoretical problems associated with air-saturated water and O2-saturated water in water calorimeters are discussed

  5. Development of Quartz Fiber Calorimetry

    CERN Multimedia

    2002-01-01

    % RD40 \\\\ \\\\ Very Forward Calorimeters (VFCs) in LHC detectors should cover the pseudorapidity range from $\\eta$~=~2.5 to at least $\\eta$~=~5 in order to compute missing transverse energy and for jet tagging. Operation at such high rapidity requires the use of a calorimetry technique that is very radiation resistant, fast and insensitive to radioactivity (especially to neutrons). This can be accomplished through the Quartz-Calorimeter~(Q-Cal) concept of embedding silica core fibers, that resist to the Gigarad radiation level, into an absorber. In this calorimeter the shower particles produce light through the Cherenkov effect generating a signal less than 10~ns in duration. Unique to this new technology the visible energy of hadronic showers has a transverse dimension nearly an order of magnitude smaller than that in conventional calorimeters, enabling precise spatial resolution, sharper isolation cuts and better jet recognition against the minimum bias events background. Last but not least, most radioactive ...

  6. Tritium inventory measurements using calorimetry

    International Nuclear Information System (INIS)

    In the past calorimetry has been developed as a powerful tool in radiometrology. Calorimetric methods have been applied for the determination of activities, half lives and mean energies released during the disintegration of radioactive isotopes. The fundamental factors and relations which determine the power output of radioactive samples are presented and some basic calorimeter principles are discussed in this paper. At the Kernforschungszentrum Karlsruhe (KfK) a family of 3 calorimeters has been developed to measure the energy release from radiative waste products arising from reprocessing operations. With these calorimeters, radiative samples with sizes from a few cm3 to 2 ·105 cm3 and heat ratings ranging from a few nW to kW can be measured. After modifications of tits inner part the most sensitive calorimeter among the three calorimeters mentioned above would be best suited for measuring the tritium inventory in T-getters of the Amersham-type

  7. Micromegas for imaging hadronic calorimetry

    CERN Document Server

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

    2011-01-01

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

  8. Dijet mass resolution and compensating calorimetry

    International Nuclear Information System (INIS)

    The calorimetry for SSC detectors has as its role the detection of the basic particles of the Standard Model. Those germane to calorimetry are quarks, photons, electrons, and gluons. Note that all the hadronic entities appear in the calorimetry as jets. The detection of single hadrons belongs to a past era when ''quark molecules'' were the focus of intense study. Thus, the goal of calorimetry at the SSC must be the study of jets. In particular, one must understand what defines the limits of accuracy of the jets. If there are intrinsic physical processes which limit the precision of jet measurements, then calorimetry which is more accurate is unnecessary if not wasteful. 5 refs., 5 figs

  9. WA80 BGO calorimetry electronics

    International Nuclear Information System (INIS)

    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-cm2 photodiodes were used per 2.5 cm x 2.5 cm x 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 μs 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

  10. Automatic calorimetry system monitors RF power

    Science.gov (United States)

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

    1969-01-01

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

  11. Entropy production in ac-calorimetry

    OpenAIRE

    Garden, Jean-Luc; Richard, Jacques

    2007-01-01

    In calorimetry and particularly in heat capacity measurements, different characteristic relaxation time constants may perturb the experiment which cannot be considered at thermodynamic equilibrium. In this case, thermodynamics of irreversible processes has to be taken into account and the calorimetric measurements must be considered as dynamic. In a temperature modulated experiment, such as ac-calorimetry, these non-equilibrium experiments give rise to the notion of frequency dependent comple...

  12. Study of asphaltene precipitation by Calorimetry

    DEFF Research Database (Denmark)

    Verdier, Sylvain Charles Roland; Plantier, Frédéric; Bessières, David; Andersen, Simon Ivar; Stenby, Erling Halfdan; Carrier, Hervé

    2007-01-01

    Can calorimetry bring new input to the Current understanding of asphaltene precipitation? In this work, two types of precipitation were studied by means of calorimetry: addition of n-heptane into asphaltene solutions and temperature/pressure variations on a recombined live oil. The first series of...... experiments showed that weak forces determine precipitation. Indeed, isothermal titration calorimetry could not detect any clear signal although this technique can detect low-energy transitions such as liquid-liquid equilibrium and rnicellization. The second series of tests proved that precipitation caused by...... T and P variations is exothermic for this system. Furthermore, the temperature-induced precipitation is accompanied by an increase in the apparent thermal expansivity. Therefore, it seems that these two phase transitions exhibit different calorimetric behaviours and they may not be as similar as...

  13. Calorimetry and thermal methods in catalysis

    CERN Document Server

    Auroux, Aline

    2013-01-01

    The book is about calorimetry and thermal analysis methods, alone or linked to other techniques, as applied to the characterization of catalysts, supports and adsorbents, and to the study of catalytic reactions in various domains: air and wastewater treatment, clean and renewable energies, refining of hydrocarbons, green chemistry, hydrogen production and storage. The book is intended to fill the gap between the basic thermodynamic and kinetics concepts acquired by students during their academic formation, and the use of experimental techniques such as thermal analysis and calorimetry to answ

  14. New crystals for dual-readout calorimetry

    Czech Academy of Sciences Publication Activity Database

    Akchurin, N.; Bedeschi, F.; Cardini, A.; Carosi, R.; Ciapetti, G.; Ferrari, R.; Franchino, S.; Fraternali, M.; Gaudio, G.; Hauptman, J.; Incagli, M.; Korzhik, M.; Lacava, F.; La Rotonda, L.; Livan, M.; Meoni, E.; Nikl, Martin; Pinci, D.; Policicchio, A.; Popescu, S.; Scuri, F.; Sill, A.; Vandelli, W.; Vedda, A.; Venturelli, T.; Voena, C.; Volobouev, I.; Wigmans, R.

    2009-01-01

    Roč. 604, č. 3 (2009), s. 512-526. ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10100521 Keywords : calorimetry * Cherenkov light * high-Z scintillating crystals Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.317, year: 2009

  15. HDTHe calorimetry v.1.0

    Energy Technology Data Exchange (ETDEWEB)

    2016-01-12

    The software generates predicted results of differential scanning calorimetry experiments for samples of palladium in a perforated capsule in an atmosphere containing a mixture of hydrogen isotopologues and helium. It can also be used to predict the results of absorption-desorption experiments at constant temperature and solid-phase isotopic ratio.

  16. Final Technical Report CMS fast optical calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Winn, David R. [Fairfield Univ., CT (United States)

    2012-07-12

    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.

  17. Isothermal Titration Calorimetry in the Student Laboratory

    Science.gov (United States)

    Wadso, Lars; Li, Yujing; Li, Xi

    2011-01-01

    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…

  18. Calculation of Temperature Rise in Calorimetry.

    Science.gov (United States)

    Canagaratna, Sebastian G.; Witt, Jerry

    1988-01-01

    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)

  19. Cerium fluoride crystals for calorimetry at LHC

    International Nuclear Information System (INIS)

    High-resolution homogeneous calorimetry is fully justified for part of the physics program at the Large Hadron Collider (LHC). The main design features of proposed CeF3 crystals for calorimetry for LHC are discussed. The severe constraints LHC imposes on detectors make the use of 'classical' crystals impossible. Therefore, a large R and D effort has been undertaken by the 'Crystal Clear' collaboration in order to find new, dense, fast and radiation hard crystals. A good candidate, cerium fluoride, has been identified and studied. It is interesting at this stage to review the specifications of scintillators for LHC and to see how well available data on CeF3 luminescence, decay time, light yield, optical transmission and resistance to radiation meet them. Milestones to reach before starting a large scale crystal production in view of the eventual construction of a calorimeter, are also discussed. (author) 15 refs., 15 figs., 1 tab

  20. CDF [Collider Detector at Fermilab] calorimetry

    International Nuclear Information System (INIS)

    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 20 to 1780, 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

  1. Analysis of Cooperativity by Isothermal Titration Calorimetry

    OpenAIRE

    Alan Brown

    2009-01-01

    Cooperative binding pervades Nature. This review discusses the use of isothermal titration calorimetry (ITC) in the identification and characterisation of cooperativity in biological interactions. ITC has broad scope in the analysis of cooperativity as it determines binding stiochiometries, affinities and thermodynamic parameters, including enthalpy and entropy in a single experiment. Examples from the literature are used to demonstrate the applicability of ITC in the characterisation of coop...

  2. Calorimetry and thermodynamics of living systems

    International Nuclear Information System (INIS)

    Calorimetry of living systems and classical thermodynamics developed in parallel, from Lavoisier's early ice calorimeter experiments on guinea pigs, followed by Dubrunfaut's macrocalorimetric research of fermentation processes and Atwater-Rosa's whole-body calorimetry on humans and domestic animals, to the introduction of the famous Tian-Calvet instrument that found entrance into so many different fields of biology. In this work, six examples of living-system calorimetry and thermodynamics are presented. These are: (i) glycolytic oscillations far off the thermodynamic equilibrium; (ii) growth and energy balances in fermenting and respiring yeast cultures; (iii) direct and indirect calorimetric monitoring of electrically stimulated reptile metabolism; (iv) biologic and climatic factors influencing the temperature constancy and distribution in the mound of a wood ant colony as an example of a complex ecological system; (v) energetic considerations on the clustering of European honeybees in winter as a means to save energy and stored food as well as for their Japanese counterparts in defending against hornet predators; and (vi) energetic and evolutionary aspects of the mass specific entropy production rate, the so-called bound dissipation or psiu-function. The examples presented here are just a very personal selection of living systems from a broad spectrum at all levels of complexity. Common for all of them is that they were investigated calorimetrically on the background of classical and irreversible thermodynamics

  3. Performance of particle flow calorimetry at CLIC

    International Nuclear Information System (INIS)

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

  4. Missing energy induced by thin hadron calorimetry

    International Nuclear Information System (INIS)

    It is relatively straightforward to estimate the total, unsegmented, depth required in SSC experiments. Typically depths in the range of 9--11 absorption lengths were specified by the SDC and GEM experiments. With these depths, the induced missing energy signal due to calorimeter leakage was found to be well below the signals caused by light gluinos, and the exterior muon systems were well protected from punch through backgrounds. In certain applications, where calorimetry is inscribed inside the magnetic field producing coils, that depth of calorimetry becomes exceedingly expensive. Examples are the ZEUS barrel and the proposed CMS barrel calorimeters. The problems can be alleviated by placing a ''tailcatcher'' of active elements outside the coil, but the problem of inert material placed within the active volume of the calorimetry remains. This inert material can potentially induce missing transverse energy signals which are large with respect to real physics signatures. The purpose of this note is to explore schemes to minimize the measured leakage energy

  5. Scintillating Fibre Calorimetry at the LHC

    CERN Multimedia

    2002-01-01

    Good electromagnetic and hadronic calorimetry will play a central role in an LHC detector. The lead/scintillating fibre calorimeter technique provides a fast signal response well matched to the LHC rate requirements. It can be made to give equal response for electrons and hadrons (compensation) with good electromagnetic and hadronic energy resolutions.\\\\ \\\\ The aim of this R&D proposal is to study in detail the aspects that are relevant for application of this type of calorimeter in an LHC environment, including its integration in a larger system of detectors, e.g.~projective geometry, radiation hardness, light detection, calibration and stability monitoring, electron/hadron separation.....

  6. Isothermal calorimetry of enzymatic biodiesel reaction

    DEFF Research Database (Denmark)

    Fjerbæk Søtoft, Lene; Westh, Peter; Christensen, Knud Villy;

    2010-01-01

      Isothermal calorimetry ITC has been used to investigate enzymatic biodiesel production. The transesterification of rapeseed oil with methanol and ethanol was catalyzed by the immobilized lipase Novozym 435 at 40°C. The ITC-experiments clearly demonstrate the possibilities of investigating complex...... and composition change in the system, the heat of reaction at 40°C for the two systems has been determined to -9.8 ± 0.9 kJ/mole biodiesel formed from rapeseed oil and methanol, and - 9.3 ± 0.7 kJ/mole when rapeseed oil and ethanol is used....

  7. Calorimetry of the CMD-3 detector

    Science.gov (United States)

    Shebalin, V. E.; Akhmetshin, R. R.; Anisenkov, A. V.; Aulchenko, V. M.; Bashtovoy, N. S.; Epifanov, D. A.; Epshteyn, L. B.; Erofeev, A. L.; Grebenuk, A. A.; Grigoriev, D. N.; Ignatov, F. V.; Kazanin, V. F.; Kovalenko, O. A.; Kozyrev, A. N.; Kuzmenko, A. E.; Kuzmin, A. S.; Logashenko, I. B.; Mikhailov, K. Yu.; Okhapkin, V. S.; Razuvaev, G. P.; Ruban, A. A.; Shwartz, B. A.; Titov, V. M.; Talyshev, A. A.; Yudin, Yu. V.

    2016-07-01

    CMD-3 is a general purpose detector designed to study e+e- annihilation into hadrons. It is mounted at VEPP-2000 collider which operates in the wide energy range, E c . m . s = 0.32 - 2 GeV. The calorimetry at the detector is based on three subsystems: closest to the beam pipe barrel Liquid Xenon calorimeter, outer barrel calorimeter based on CsI scintillation crystals and the endcap calorimeter made of BGO scintillation crystals. We describe the structure of the calorimeters, their electronics and the energy calibration procedures.

  8. Silicon calorimetry for the SSC[ Superconducting Supercollider

    International Nuclear Information System (INIS)

    SSC experiments will rely heavily on their calorimeters. Silicon calorimetry, which has been introduced in recent years as a useful technology, has many attractive characteristics which may make it a viable option for consideration. The many attractive properties of silicon detectors are reviewed. The relevant present day applications of large areas of silicon detectors are summarize to illustrate the emerging use. The troublesome issue of radiation damage in a high luminosity environment like the SSC is considered with a summary of much of the recent new measurements which help clarify this situation. A discussion of the electronics and a possible mechanical configuration is presented, followed by a summary of the outstanding R and D issues. 31 refs., 11 figs., 3 tabs

  9. Isothermal calorimetry on enzymatic biodiesel production

    DEFF Research Database (Denmark)

    Fjerbæk, Lene

    2008-01-01

    information about effects taking place when using lipases immobilized on an inert carrier for transesterification of a triglyceride and an alcohol as for biodiesel production. The biodiesel is produced by rapeseed oil and methanol as well as ethanol and a commercial biocatalyst Novozym 435 from Novozymes...... containing a Candida Antarctica B lipase immobilized on an acrylic resin. The reaction investigated is characterized by immiscible liquids (oil, methanol, glycerol and biodiesel) and enzymes imm. on an inert carrier during reaction, which allows several effects to take place that during normal reaction...... conditions can not be elucidated. These effects have been observed with isothermal calorimetry bringing forth new information about the reaction of enzymes catalyzing transesterification. Enzymatic biodiesel production has until now not been investigated with isothermal microcalorimetry, but the results...

  10. Analog pipeline readout for ATLAS calorimetry

    International Nuclear Information System (INIS)

    This paper presents the design and prototype testing of an analog pipeline readout module suitable for readout of the LAr calorimetry at the large hadron collider. The design has been driven by the readout requirements of the ATLAS electromagnetic liquid argon calorimeter and the ATLAS trigger design parameters. The results indicate that an analog pipeline readout system meeting the ATLAS requirements can be built using our modules. The SCA-chip employed has resolution approaching 13-bits (using the full range of the SCA) and can achieve a 16-bit dynamic range using a dual-range scheme. The module is based on switched capacitor array chips. A brief description of the design of the pipeline controller development, that will enable the SCA readout system to run as a deadtimeless analog RAM, is also given. (orig.)

  11. Calorimetry studies on U-Cr alloys

    International Nuclear Information System (INIS)

    A calorimetric study of Uranium-Chromium system is of interest on both basic and applied fronts. With the advent of U-Pu-Zr alloy as the fuel, in combination with ferritic-martensitic steel as the cladding material, the metal fuelled fast reactors constitute the second major step in Indian nuclear power program. In such a context, a fundamental investigation on the high temperature phase stability of U-Cr alloys is of particular relevance in getting further insight in to the complex issue of the metallurgical compatibility of ferritic steels with metallic Uranium-Zirconium fuel. It may be added that following U-Fe, and U-Zr binaries, the U-Cr constitutes one of the important subsystems of the complex U-Zr-Pu-Fe- Cr-Mn-Si-V-Nb-C-N multinary system. In the current study, the results of calorimetry investigations on U, U-2, 3, 7, 15wt. % Cr alloys are presented

  12. Bipolar monolithic preamplifiers for SSC silicon calorimetry

    International Nuclear Information System (INIS)

    This paper describes preamplifiers designed specifically to address the requirements of silicon calorimetry for the Superconducting Super Collider (SSC). Eight different preamplifiers designed for detector capacitances ranging from 20 pF to 500 pF and operating temperatures from 25 degree C to -20 degree C are discussed. The preamplifiers were fabricated with two different high-frequency processes (one with the VTC, Inc. VJ900 process, seven with the Harris Semiconductor VHF Process). The different topologies and their features are discussed in addition to the design methodologies employed. The results for noise, power consumption, speed, and radiation damage effects as well as data for post-damage annealing are presented for the VTC process preamplifier. Simulations for the VHF Process circuits are presented. This work was funded through SSC Generic Detector funding, SSC Detector Subsystem funding, and the Oak Ridge National Laboratory (ORNL) Detector Center

  13. Titration Calorimetry Standards and the Precision of Isothermal Titration Calorimetry Data

    OpenAIRE

    Daumantas Matulis; Jurgita Matulienė; Vilma Petrikaitė; Lina Baranauskienė

    2009-01-01

    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 sug...

  14. Differential Scanning Calorimetry Techniques: Applications in Biology and Nanoscience

    OpenAIRE

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

    2010-01-01

    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.

  15. Calorimetry for ILC Experiments: CALICE Collaboration R&D

    OpenAIRE

    Bailey, D.S.; Collaboration, for the CALICE

    2008-01-01

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

  16. Current status of tritium calorimetry at TLK

    International Nuclear Information System (INIS)

    Inside a tritium facility, calorimetry is an important analytical method as it is the only reference method for accountancy (it is based on the measurement of the heat generated by the radioactive decay). Presently, at Tritium Laboratory Karlsruhe (TLK), 4 calorimeters are in operation, one of isothermal type and three of inertial guidance control type (IGC). The volume of the calorimeters varies between 0.5 and 20.6 liters. About two years ago we started an extensive work to improve our calorimeters with regard to reliability and precision. We were forced to upgrade 3 of our 4 calorimeters due to the outdated interfaces and software. This work involved creating new LabView programs driving the devices, re-tuning control loops and replacing obsolete hardware components. In this paper we give a review on the current performance of our calorimeters, comparing it to recently available devices from the market and in the literature. We also show some ideas for a next generation calorimeter based on experiences with our IGC calorimeters and other devices reported in the literature. (authors)

  17. Melting by temperature-modulated calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    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

    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.

  18. The analysis of Al-based alloys by calorimetry: quantitative analysis of reactions and reaction kinetics

    OpenAIRE

    Starink, M.J.

    2004-01-01

    Differential scanning calorimetry (DSC) and isothermal calorimetry have been applied extensively to the analysis of light metals, especially Al based alloys. Isothermal calorimetry and differential scanning calorimetry are used for analysis of solid state reactions, such as precipitation, homogenisation, devitrivication and recrystallisation; and solid–liquid reactions, such as incipient melting and solidification, are studied by differential scanning calorimetry. In producing repeatable calo...

  19. Summary session of the Gas Sampling Calorimetry Workshop

    International Nuclear Information System (INIS)

    The summary session of the Gas Sampling Calorimetry Workshop was a review and discussion session. A number of questions were raised and briefly discussed. More extensive discussions of energy resolution formed the heart of the final session

  20. Determination of Purity by Differential Scanning Calorimetry (DSC).

    Science.gov (United States)

    Brown, M. E.

    1979-01-01

    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)

  1. Effects of experimental variables in quantitative differential scanning calorimetry

    OpenAIRE

    Dooren, Adrianus August van

    1982-01-01

    Dit proefschriÍt beschrijft een onderzoek naar de effecten van experimentele omstandigheden op curve-karakteristieken en enige toepassingen van kwantitatieve Differentiele Scanning calorimetry (DSC). ... Zie: Samenvatting

  2. Application of adiabatic calorimetry to metal systems. Final report

    International Nuclear Information System (INIS)

    Research on the application of adiabatic calorimetry to metal systems is described. Investigations into formation of pearlite in steels, ferromagnetic effects, cold working and annealing, solid solution alloys, pure solid metals, and pure liquid metals, are briefly described

  3. Isothermal Calorimetry for Biological Applications in Food Science and Technology

    OpenAIRE

    Wadsö, Lars; Gomez, Federico

    2009-01-01

    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 kinetics of a fermentation process can be studied, and how spoilage processes can be followed f...

  4. Particle Flow Calorimetry and the PandoraPFA Algorithm

    OpenAIRE

    Thomson, M. A.

    2009-01-01

    The Particle Flow (PFlow) approach to calorimetry promises to deliver unprecedented jet energy resolution for experiments at future high energy colliders such as the proposed International Linear Collider (ILC). This paper describes the PandoraPFA particle flow algorithm which is then used to perform the first systematic study of the potential of high granularity PFlow calorimetry. For simulated events in the ILD detector concept, a jet energy resolution of sigma_E/E < 3.8 % is achieved for 4...

  5. Continuing Studies on Lead/Scintillating Fibres Calorimetry (LFC)

    CERN Multimedia

    2002-01-01

    Starting from the results obtained in the framework of the LAA Project~2B, we propose a continuation of the R&D on lead/scintillating fibres calorimetry (``spaghetti calorimetry''), including further tests on the old calorimeter prototypes and the construction and testing of new prototypes. The main results we pursue concern the performances of a projective calorimeter built with new, cheaper, techniques and the radiation hardness of the scintillating fibres, the optimization of a preshower detector system is also studied.

  6. Differential scanning calorimetry of superelastic Nitinol for tunable cymbal transducers

    OpenAIRE

    Feeney, Andrew; Lucas, Margaret

    2015-01-01

    Recent research has shown that estimations of the transformation temperatures of superelastic Nitinol using differential scanning calorimetry can be inaccurate, in part, due to the residual stress in the material. Superelastic Nitinol is selected as the end-cap material in a tunable cymbal transducer. The differential scanning calorimetry accuracy is initially probed by comparing transformation temperature measurements of cold-worked superelastic Nitinol with the same material after an anneal...

  7. Energy expenditure in critically ill patients estimated by population-based equations, indirect calorimetry and CO2-based indirect calorimetry

    OpenAIRE

    Rousing, Mark Lillelund; Hahn-Pedersen, Mie Hviid; Andreassen, Steen; Pielmeier, Ulrike; Preiser, Jean-Charles

    2016-01-01

    Background Indirect calorimetry (IC) is the reference method for measurement of energy expenditure (EE) in mechanically ventilated critically ill patients. When IC is unavailable, EE can be calculated by predictive equations or by VCO2-based calorimetry. This study compares the bias, quality and accuracy of these methods. Methods EE was determined by IC over a 30-min period in patients from a mixed medical/postsurgical intensive care unit and compared to seven predictive equations and to VCO2...

  8. Liquid Argon Calorimetry with LHC-Performance Specifications

    CERN Multimedia

    2002-01-01

    % RD-3 Liquid Argon Calorimetry with LHC-Performance Specifications \\\\ \\\\Good electromagnetic and hadronic calorimetry will play a central role in an LHC detector. Among the techniques used so far, or under development, the liquid argon sampling calorimetry offers high radiation resistence, good energy resolution (electromagnetic and hadronic), excellent calibration stability and response uniformity. Its rate capabilities, however, do not yet match the requirements for LHC. \\\\ \\\\The aim of this proposal is to improve the technique in such a way that high granularity, good hermiticity and adequate rate capabilities are obtained, without compromising the above mentioned properties. To reach this goal, we propose to use a novel structure, the $^{\\prime\\prime}$accordion$^{\\prime\\prime}$, coupled to fast preamplifiers working at liquid argon temperature. Converter and readout electrodes are no longer planar and perpendicular to particles, as usual, but instead they are wiggled around a plane containing particles. ...

  9. Optimization of crystals for applications in dual-readout calorimetry

    Czech Academy of Sciences Publication Activity Database

    Akchurin, N.; Bedeschi, F.; Cardini, A.; Carosi, R.; Ciapetti, G.; Fasoli, M.; Ferrari, R.; Franchino, S.; Fraternali, M.; Gaudio, G.; Hauptman, J.; Incagli, M.; Lacava, F.; La Rotonda, L.; Lee, S.; Livan, M.; Meoni, E.; Nikl, Martin; Pinci, D.; Policicchio, A.; Popescu, S.; Scuri, F.; Sill, A.; Susinno, G.; Vandelli, W.; Vedda, A.; Venturelli, T.; Voena, C.; Volobouev, I.; Wigmans, R.

    2010-01-01

    Roč. 621, 1-3 (2010), 212-221. ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10100521 Keywords : calorimetry * Cherenkov light * High-Z scintillating crystals Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.142, year: 2010

  10. Warm-up calorimetry of Dewar-Detector Assemblies

    Science.gov (United States)

    Veprik, A.; Shlomovich, B.; Tuito, A.

    2015-12-01

    Boil-off isothermal calorimetry of Dewar-Detector Assemblies (DDA) is a routine part of their Acceptance Testing Procedure. In this approach, the cryogenic liquid coolant (typically LN2) is allowed to naturally boil-off from the Dewar well to the atmosphere through a mass flow meter; the parasitic heat load is then evaluated as the product of the latent heat of vaporization and the "last drop" boil-off rate. An inherent major limitation of this technique is that it may be performed only at the fixed boiling temperature of the chosen liquid coolant. A further drawback is related to the explosive nature of "last drop" boiling, manifesting itself as an uneven flow rate. This especially holds true for advanced High Operational Temperature Dewar-Detector Assemblies, typically featuring short cold fingers and working at 150 K and above. In this work, we adapt the well-known technique of dual-slope calorimetry and show how accurate heat load evaluation may be performed by comparing the slopes of the warm-up thermal transients under different trial added heat loads. Because of the simplicity, accuracy and ability to perform calorimetry literally at any temperature of interest, this technique shows good potential for replacing traditional boil-off calorimetry.

  11. The Heats of Dilution Calorimetry and Van't-Hoff

    CERN Document Server

    Stepanov, I A

    2000-01-01

    Earlier it has been found that there is a big difference between heats of dilution measured by calorimetry and by the Van't-Hoff equation. In the present paper a reason for that is proposed. Experimental data for dilution of benzene and n-hexane in water were used.

  12. Fast differential scanning calorimetry of liquid samples with chips

    DEFF Research Database (Denmark)

    Splinter, R.; van Herwaarden, A. W.; van Wetten, I. A.;

    2015-01-01

    Based on a modified version of standard chips for fast differential scanning calorimetry, DSC of liquid samples has been performed at temperature scan rates of up to 1000 °C/s. This paper describes experimental results with the protein lysozyme, bovine serum, and olive oil. The heating and cooling...

  13. Isothermal Titration Calorimetry Can Provide Critical Thinking Opportunities

    Science.gov (United States)

    Moore, Dale E.; Goode, David R.; Seney, Caryn S.; Boatwright, Jennifer M.

    2016-01-01

    College chemistry faculties might not have considered including isothermal titration calorimetry (ITC) in their majors' curriculum because experimental data from this instrumental method are often analyzed via automation (software). However, the software-based data analysis can be replaced with a spreadsheet-based analysis that is readily…

  14. Preparation of Solid Derivatives by Differential Scanning Calorimetry.

    Science.gov (United States)

    Crandall, E. W.; Pennington, Maxine

    1980-01-01

    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…

  15. The Heats of Dilution. Calorimetry and Van't-Hoff

    OpenAIRE

    Stepanov, I. A.

    2000-01-01

    Earlier it has been found that there is a big difference between heats of dilution measured by calorimetry and by the Van't-Hoff equation. In the present paper a reason for that is proposed. Experimental data for dilution of benzene and n-hexane in water were used.

  16. Historical roots and development of thermal analysis and calorimetry

    Czech Academy of Sciences Publication Activity Database

    Šesták, J.; Hubík, Pavel; Mareš, Jiří J.

    Dodrecht: Springer, 2011 - (Šesták, J.; Mareš, J.; Hubík, P.), s. 347-370 ISBN 978-90-481-2881-5 Institutional research plan: CEZ:AV0Z10100521 Keywords : thermal analysis * calorimetry * history * Carnot ideas * personalities * DTA * ICTA Subject RIV: BM - Solid Matter Physics ; Magnetism

  17. Optimization of Crystals for Applications in Dual-readout Calorimetry

    International Nuclear Information System (INIS)

    Dual-Readout Calorimetry is a promising new technique for high resolution hadron and jet calorimetry. It is based on simultaneous measurements of the scintillation and Cherenkov light generated in the shower development process. Due to the fact that the Cherenkov light is only produced by the electromagnetic shower component, the relative contribution of this component to the signals can be measured on the event by event basis, resulting in reduction of fluctuations. This leads to an important improvement in the hadronic calorimeter performance. Further improvement on both the electromagnetic and hadronic resolution can be achieved by using homogeneous, dense crystals. This reduces both the sampling fluctuations and the quantum fluctuations. We present a systematic study of lead tungstate crystals doped with a small fraction of molybdenum, varying between 0.1% and 5% and exploring different readout configurations.

  18. Monitoring assembly of ribonucleoprotein complexes by isothermal titration calorimetry

    OpenAIRE

    Recht, Michael I.; Ryder, Sean P.; Williamson, James R.

    2008-01-01

    Isothermal titration calorimetry (ITC) is a useful technique to study RNA-protein interactions, as it provides the only method by which the thermodynamic parameters of free energy, enthalpy, and entropy can be directly determined. This chapter presents a general procedure for studying RNA-protein interactions using ITC, and gives specific examples for monitoring the binding of Caenorhabditis elegans GLD-1 STAR domain to TGE RNA and the binding of Aquifex aeolicus S6:S18 ribosomal protein hete...

  19. Thermal Polymerization of Acrylamide by Differential Scanning Calorimetry

    OpenAIRE

    Kishore, K.; Santhanalakshmi, KN

    1981-01-01

    Thermal polymerization of acrylamide was studied by differential scanning calorimetry. Latent heat of fusion \\bigtriangleup Hf and enthalpy of polymerization \\bigtriangleup Hp values were found to be 36 and $-18.0 kcal mol^{-1}$, respectively. The overall activation energy E for the polymerization was calculated to be $19 k cal mol^{-1}$ up to 60% conversion. The added free-radical inhibitor (benzoquinone) was found to desensitize the thermal polymerization of acrylamide suggesting the polyme...

  20. Application of kinetic inductance thermometers to x-ray calorimetry

    International Nuclear Information System (INIS)

    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. 13 refs., 6 figs., 1 tab

  1. Depth of calorimetry for SSC [Superconducting Super Collider] experiments

    International Nuclear Information System (INIS)

    The depth of calorimetry required for SSC experiments is investigated using data of hadronic shower development in neutrino detectors and a parameterization of average hadronic shower shapes. The effect of hadronic shower fluctuations is included. A depth of nine to ten proton absorption lengths in iron is found to be sufficient to contain at least 95% of the energy of 95% of 1-TeV jets. 6 refs., 5 figs

  2. Accurate Measurement of Heat Capacity by Differential Scanning Calorimetry

    Science.gov (United States)

    1984-01-01

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

  3. The upgraded CDF front end electronics for calorimetry

    International Nuclear Information System (INIS)

    The front end electronics used in the calorimetry of the CDF detector has been upgraded to meet system requirements for higher expected luminosity. A fast digitizer utilizing a 2 μSec, 16 bit ADC has been designed and built. Improvements to the front end trigger circuitry have been implemented, including the production of 900 new front end modules. Operational experience with the previous system is presented, with discussion of the problems and performance goals

  4. Direct Animal Calorimetry, the Underused Gold Standard for Quantifying the Fire of Life*

    OpenAIRE

    Kaiyala, Karl J.; Ramsay, Douglas S.

    2010-01-01

    Direct animal calorimetry, the gold standard method for quantifying animal heat production (HP), has been largely supplanted by respirometric indirect calorimetry owing to the relative ease and ready commercial availability of the latter technique. Direct calorimetry, however, can accurately quantify HP and thus metabolic rate (MR) in both metabolically normal and abnormal states, whereas respirometric indirect calorimetry relies on important assumptions that apparently have never been tested...

  5. Simultaneous Thermodynamic and Kinetic Parameters Determination Using Differential Scanning Calorimetry

    Directory of Open Access Journals (Sweden)

    Nader Frikha

    2011-01-01

    Full Text Available Problem statement: The determination of reaction kinetics is of major importance, as for industrial reactors optimization as for environmental reasons or energy limitations. Although calorimetry is often used for the determination of thermodynamic parameters alone, the question that arises is: how can we apply the Differential Scanning Calorimetry for the determination of kinetic parameters. The objective of this study consists to proposing an original methodology for the simultaneous determination of thermodynamic and kinetic parameters, using a laboratory scale Differential Scanning Calorimeter (DSC. The method is applied to the dichromate-catalysed hydrogen peroxide decomposition. Approach: The methodology is based on operating of experiments carried out with a Differential Scanning Calorimeter. The interest of this approach proposed is that it requires very small quantities of reactants (about a few grams to be implemented. The difficulty lies in the fact that, using such microcalorimeters, the reactants temperature cannot directly be measured and a particular calibration procedure has thus to be developed, to determine the media temperature in an indirect way. The proposed methodology for determination of kinetics parameters is based on resolution of the coupled heat and mass balances. Results: A complete kinetic law is proposed. The Arrhenius parameters are determined as frequency factor k0 = 1.39×109 s−1 and activation energy E = 54.9 kJ mol−1. The measured enthalpy of reaction is ΔrH=−94 kJ mol−1. Conclusion: The comparison of the results obtained by such an original methodology with those obtained using a conventional laboratory scale reactor calorimetry, for the kinetics determination of, shows that this new approach is very relevant.

  6. [Experimental high energy physics using electromagnetic energy calorimetry

    International Nuclear Information System (INIS)

    In the current year, the major part of the research on this contract was focussed on the construction of the DO detector, testing of production modules (as opposed to prototypes) and in actual coding of tracking software. We are contributing in two areas to the DO Project: the calorimetry, where we are involved in coordination, construction and testing of the central and end calorimeter modules, the test beam program and software development; and the central drift chamber being constructed at Stony Brook and for which we have developed the electronics, test facilities, tracking and general purpose software

  7. Differential scanning calorimetry (DSC) of ThO2

    International Nuclear Information System (INIS)

    In view of vast resources of thorium in the country, its utilisation has been identified as a key element in our country's nuclear energy programme to meet the long time energy security. As a part of a comprehensive programme undertaken for investigating the physico-chemical properties of thorium and its compounds, thermal studies have been carried out employing differential scanning calorimetry (DSC) to measure the heat capacity of ThO2. A number of parameters have been investigated to arrive at the optimum conditions for this measurement

  8. On the Interpretation of Low Temperature Calorimetry Data

    DEFF Research Database (Denmark)

    Kjeldsen, Ane Mette; Geiker, Mette Rica

    2008-01-01

    The effect of selected factors and phenomena on Low Temperature Calorimetry (LTC) results has been investigated, in order to determine the possibilities and limitations of using LTC for characterisation of the porosity of cement-based materials. LTC was carried out on a model material with mono...... ions on freezing point depression into account. It is proposed that the connectivity of pores, e.g. in cement-based materials, may be characterised based on cooling curves, whereas the pore size distribution may be characterised based on the heating curve. Cooling should be undertaken at a high rate to...

  9. Fabrication of 12% {sup 240}Pu calorimetry standards

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-08-01

    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.

  10. Fast, radiation-hard charge preamplifier for warm liquid calorimetry

    International Nuclear Information System (INIS)

    The authors describe the design, construction, and operation of an ultra-sensitive, high-bandwidth charge preamplifier for calorimetry at the Superconducting Super Collider. The design is based on a monolithic, bipolar technology with 5 Mrad radiation hardness. The intrinsic low noise (≤ 600 e- rms) and low power consumption (60 mwatt) of this device at room temperature make it an attractive front-end preamp for either warm or cryogenic liquid media detectors, or even for tetrodes for scintillating fiber technology. Measurements are reported on a prototype device built in an industrial BiFET process with a 37 nsec risetime

  11. Application of pressure perturbation calorimetry to lipid bilayers.

    OpenAIRE

    Heerklotz, Heiko; Seelig, Joachim

    2002-01-01

    Pressure perturbation calorimetry (PPC) is a new method that measures the heat consumed or released by a sample after a sudden pressure jump. The heat change can be used to derive the thermal volume expansion coefficient, alpha(V), as a function of temperature and, in the case of phase transitions, the volume change, DeltaV, occurring at the phase transition. Here we present the first report on the application of PPC to determine these quantities for lipid bilayers. We measure the volume chan...

  12. Cell asymmetry correction for temperature modulated differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

    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.

  13. A custom floating point format ADC for LHC calorimetry

    International Nuclear Information System (INIS)

    Due to their large dynamic range (in excess of 16 bits) signals from LHC calorimetry poses severe problems to the shaping and digitizing circuits. We are investigating a solution for an ADC based on a custom floating point format. Since the calorimeter precision is limited, the full dynamic range can be split into 8 positive sub-ranges and 5 negative ones, each with an 8 bits dynamic. The reduced number of bits (8 for the mantissa, 4 for the exponent and 1 for the sign) translates itself into a reduction of the power consumption both of the ADC and of the following digital filtering stages. (authors)

  14. Evaluation of aluminosilicate glass sintering during differential scanning calorimetry

    International Nuclear Information System (INIS)

    In this work a difference in the baseline in differential scanning calorimetry analyses, observed in a work where aluminosilicate glasses microspheres containing Ho were studied for application in selective internal radiotherapy as hepatocellular carcinoma treatment, was studied. The glasses with nominal composition 53,7 SiO2 .10,5 Al2O3 . 35,8 MgO in %mol were produced from traditional melting. The first obtained were milled and sieved in the range of 45 a 63 μm. The material was used to produce glass microspheres by the gravitational fall method. The glass powder and the microspheres were characterized by X ray fluorescence spectrometry, laser diffraction, X ray diffraction, differential scanning calorimetry, differential thermal analysis, thermogravimetry, mass spectrometry, and scanning electron microscopy. After the thermal analyses, pellets were formed in the crucibles and were analyzed by scanning electron microscopy, X ray diffraction, and He pycnometry. The difference in the baseline was associated to the viscous flow sintering process and happens because of the decrease in the detected heat flow due to the sample shrinkage. Other events as concurrent crystallization with the sintering process were also studied. (author)

  15. Application of an open circuit indirect calorimetry system for gaseous exchange measurements in small ruminant nutrition

    OpenAIRE

    CRISCIONI FERREIRA, PATRICIA FABIOLA

    2016-01-01

    [EN] The main objective of this Thesis was to study the energy metabolism in small ruminants under different nutrition sceneries. As methodology we utilized indirect calorimetry instead of direct calorimetry or feeding trials. Within indirect calorimetry we worked with a portable open circuit gas exchange system with a head hood. This open circuit respiration system permitted completed the whole energy balance and evaluate the efficiency of utilization of the energy of the diet for different ...

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

    OpenAIRE

    Vlassak, Joost J.; Xiao, Kechao; John M. Gregoire; McCluskey, Patrick J.

    2012-01-01

    We present a scanning AC nanocalorimetry method that enables calorimetry measurements at heating and cooling rates that vary from isothermal to \\(2×10^3 K/s\\), thus bridging the gap between traditional scanning calorimetry of bulk materials and nanocalorimetry. The method relies on a micromachined nanocalorimetry sensor with a serpentine heating element that is sensitive enough to make measurements on thin-film samples and composition libraries. The ability to perform calorimetry over such a ...

  17. Fast Scanning Calorimetry Studies of Supercooled Liquids and Glasses

    Science.gov (United States)

    Bhattacharya, Deepanjan

    This dissertation is a compilation of research results of extensive Fast Scanning Calorimetry studies of two non-crystalline materials: Toluene and Water. Motivation for fundamental studies of non-crystalline phases, a brief overview of glassy materials and concepts and definitions related to them is provided in Chapter 1. Chapter 2 provides fundamentals and details of experimental apparata, experimental protocol and calibration procedure. Chapter 3 & 4 provides extensive studies of stable non-crystalline toluene films of micrometer and nanometer thicknesses grown by vapor deposition at distinct deposition rates and temperatures and probed by Fast Scanning Calorimetry. Fast scanning calorimetry is shown to be extremely sensitive to the structure of the vapor-deposited phase and was used to characterize simultaneously its kinetic stability and its thermodynamic properties. According to our analysis, transformation of vapor -deposited samples of toluene during heating with rates in excess 100,000 K/s follows the zero-order kinetics. The transformation rate correlates strongly with the initial enthalpy of the sample, which increases with the deposition rate according to sub-linear law. Analysis of the transformation kinetics of vapor deposited toluene films of various thicknesses reveal a sudden increase in the transformation rate for films thinner than 250 nm. The change in kinetics correlates with the surface roughness scale of the substrate, which is interpreted as evidence for kinetic anisotropy of the samples. We also show that out-of-equilibrium relaxation kinetics and possibly the enthalpy of vapor-deposited (VD) films of toluene are distinct from those of ordinary supercooled (OS) phase even when the deposition takes place at temperatures above the glass softening (Tg). The implications of these findings for the formation mechanism and structure of vapor deposited stable glasses are discussed. Chapter 5 and 6 provide detailed Fast Scanning Calorimetry studies

  18. Adsorption calorimetry of conjugated organic molecules on metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lytken, Ole; Drescher, Hans-Joerg; Bebensee, Fabian; Steinrueck, Hans-Peter; Gottfried, J. Michael [Universitaet Erlangen-Nuernberg, Lehrstuhl fuer Physikalische Chemie II (Germany)

    2011-07-01

    Traditional experimental methods for determining adsorption energies, such as temperature programmed desorption (TPD) and equilibrium adsorption isotherms, rely on desorption. However, on many metal surfaces large conjugated organic molecules, such as PTCDA and pentacene, decompose at elevated temperatures before or simultaneously with desorption. Discussions about relative bond strengths are, therefore, typically based on indirect arguments, such as the height of the adsorbed species above the surface as measured with normal incidence X-ray standing waves (NIXSW) or chemical shifts in spectroscopic techniques such as X-ray photoelectron spectroscopy (XPS). Unlike the more traditional methods, nanojoule adsorption calorimetry does not require desorption of the molecules; instead, the heat of adsorption is measured directly as an adsorption-induced temperature change of the sample. We will describe the construction of such a calorimeter at the Universitaet Erlangen-Nuernberg.

  19. Experimental high energy physics using electromagnetic energy calorimetry

    International Nuclear Information System (INIS)

    The major emphasis of the work reported has been on the construction of the DO Project for the Fermilab 2 TeV anti p p collider (TeV I). DO has three major hardware systems - calorimetry, muon and central tracking. In addition, the group is involved in the Brookhaven neutrino experiment E734. The past year has seen publication of precision measurements of sin2Θ/sub w/ from elastic scattering of neutrinos from both electrons and protons. This experiment has just concluded its final data run which is expected to increase the neutrino-electron sample to 180ν/sub μ/e and 90 anti ν/sub μ/e events

  20. Neural second-level trigger system based on calorimetry

    Science.gov (United States)

    Seixas, J. M.; Caloba, L. P.; Souza, M. N.; Braga, A. L.; Rodrigues, A. P.

    1996-06-01

    A second-level triggering system based on calorimetry is analyzed using neural networks. Calorimeter data in a LHC environment is obtained with Monte Carlo simulations and an algorithm for the first-level trigger operation is applied. The surviving events are then available as a 20×20 matrix information corresponding to the calorimeter towers in the region of interest. The dominant background for triggering on electrons is assumed to consist of QCD jets which passed the first-level trigger condition. The main features of the calorimeter are extracted. Matrix information, shower deposition in concentric rings and tail weighting procedures are studied. The processed information is sent to a fully connected backpropagation neural network. In this analysis we also consider pileup effects of an average of 20 minimum bias events. The neural network based system achieved up to 99% electron efficiency with less than 9% of jets being misclassified as electrons. Implementation on digital signal processors is suggested.

  1. Present status of CMS HF quartz fiber calorimetry

    CERN Document Server

    Önel, Y M

    2002-01-01

    The experiments at the Large Hadron Collider will have to deal with unprecedented radiation levels. The design of the CMS forward calorimetry detector (HF) is now finalized. The present design of CMS calls for the HF calorimeter to be based on quartz fiber technology. It consists of two modules, located symmetrically at about 11 meters from either side of interaction point. They cover the pseudorapidity range 3-5. The length along the beam is 1.65 m or 10 nuclear interaction lengths. Each calorimeter consists of a large steel block that serves as the absorber. Embedded quartz fibers in the steel absorber run parallel to the beam and constitute the active component of the detector. In order to optimize energy resolution for E and E /sup T/ flows and forward jets, the calorimeter is effectively segmented longitudinally by using two different fiber lengths. The present status will be discussed. (6 refs).

  2. Novel investigation of enzymatic biodiesel reaction by isothermal calorimetry

    DEFF Research Database (Denmark)

    Søtoft, Lene Fjerbaek; Westh, Peter; Christensen, Knud V.;

    2010-01-01

    Isothermal calorimetry (ITC) was used to investigate solvent-free enzymatic biodiesel production. The transesterification of rapeseed oil with methanol and ethanol was catalyzed by immobilized lipase Novozym 435 at 40 °C. The aim of the study was to determine reaction enthalpy for the enzymatic...... transesterification and to elucidate the mass transfer and energetic processes taking place. Based on the measured enthalpy and composition change in the system, the heat of reaction at 40 °C for the two systems was determined as −9.8 ± 0.9 kJ/mole biodiesel formed from rapeseed oil and methanol, and −9.3 ± 0.7 k...

  3. Particle flow calorimetry at the international linear collider

    Indian Academy of Sciences (India)

    Mark A Thomson

    2007-12-01

    One of the most important requirements for a detector at the ILC is good jet energy resolution. It is widely believed that the particle flow approach to calorimetry is the key to achieving the goal of $0.3/\\sqrt{E(GeV)}$. This paper describes the current performance of the PandoraPFA particle flow algorithm. For 45 GeV jets in the Tesla TDR detector concept, the ILC jet energy resolution goal is reached. At higher energies the jet energy resolution becomes worse and can be described by the empirical expression: $_{E}/E ≈ 0.265/\\sqrt{E(GeV)} + 1.2 times 10^{-4} E(GeV)$.

  4. Applications of isothermal titration calorimetry in protein science

    Institute of Scientific and Technical Information of China (English)

    Yi Liang

    2008-01-01

    During the past decade,isothermal titration calorimetry (ITC)has developed from a specialist method for understanding molecular interactions and other biological processes within cells to a more robust,widely used method.Nowadays,ITC is used to investigate all types of protein interactions,including protein-protein interactions,protein-DNA/RNA interactions,protein-small molecule interactions and enzyme kinetics;it provides a direct route to the complete thermodynamic characterization of protein interactions.This review concentrates on the new applications of ITC in protein folding and misfolding,its traditional application in protein interactions,and an overview of what can be achieved in the field of protein science using this method and what developments are likely to occur in the near future.Also,this review discusses some new developments of ITC method in protein science,such as the reverse titration of ITC and the displacement method of ITC.

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

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Stroud, Lee Sawyer

    2012-08-31

    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.

  6. A novel photomultiplier tube for calorimetry at the SSC

    International Nuclear Information System (INIS)

    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

  7. Hadronic shower development in Iron-Scintillator Tile Calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, P.; Amorim, A.; Anderson, K.; Barreira, G.; Benetta, R.; Berglund, S.; Biscarat, C.; Blanchot, G.; Blucher, E.; Bogush, A.; Bohm, C.; Boldea, V.; Borisov, O.; Bosman, M.; Bromberg, C.; Budagov, J.; Burdin, S.; Caloba, L.; Carvalho, J.; Casado, P.; Castillo, M.V.; Cavalli-Sforza, M.; Cavasinni, V.; Chadelas, R.; Chirikov-Zorin, I.; Chlachidze, G.; Cobal, M.; Cogswell, F.; Colaco, F.; Cologna, S.; Constantinescu, S.; Costanzo, D.; Crouau, M.; Daudon, F.; David, J.; David, M.; Davidek, T.; Dawson, J.; De, K.; Del Prete, T.; De Santo, A.; Di Girolamo, B.; Dita, S.; Dolejsi, J.; Dolezal, Z.; Downing, R.; Efthymiopoulos, I.; Engstroem, M.; Errede, D.; Errede, S.; Evans, H.; Fenyuk, A.; Ferrer, A.; Flaminio, V.; Gallas, E.; Gaspar, M.; Gil, I.; Gildemeister, O.; Glagolev, V.; Gomes, A.; Gonzalez, V.; Gonzalez De La Hoz, S.; Grabski, V.; Grauges, E.; Grenier, P.; Hakopian, H.; Haney, M.; Hansen, M.; Hellman, S.; Henriques, A.; Hebrard, C.; Higon, E.; Holmgren, S.; Huston, J.; Ivanyushenkov, Yu.; Jon-And, K.; Juste, A.; Kakurin, S.; Karapetian, G.; Karyukhin, A.; Kopikov, S.; Kukhtin, V.; Kulchitsky, Y.; Kurzbauer, W.; Kuzmin, M.; Lami, S.; Lapin, V.; Lazzeroni, C.; Lebedev, A.; Leitner, R.; Li, J.; Lomakin, Yu.; Lomakina, O.; Lokajicek, M.; Lopez Amengual, J.M.; Maio, A.; Malyukov, S.; Marroquin, F.; Martins, J.P.; Mazzoni, E.; Merritt, F.; Miller, R.; Minashvili, I.; Miralles, Ll.; Montarou, G.; Munar, A.; Nemecek, S.; Nessi, M. E-mail: marzio.nessi@cern.ch; Onofre, A.; Orteu, S.; Park, I.C.; Pallin, D.; Pantea, D.; Paoletti, R.; Patriarca, J.; Pereira, A.; Perlas, J.A.; Petit, P.; Pilcher, J.; Pinhao, J.; Poggioli, L.; Price, L.; Proudfoot, J.; Pukhov, O.; Reinmuth, G.; Renzoni, G.; Richards, R.; Roda, C.; Romance, J.B.; Romanov, V.; Ronceux, B.; Rosnet, P.; Rumyantsev, V.; Russakovich, N.; Sanchis, E.; Sanders, H.; Santoni, C.; Santos, J.; Sawyer, L.; Says, L.-P.; Seixas, J.M.; Sellden, B.; Semenov, A.; Shchelchkov, A.; Shochet, M.; Simaitis, V. [and others

    2000-03-21

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

  8. Hadronic shower development in Iron-Scintillator Tile Calorimetry

    International Nuclear Information System (INIS)

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

  9. Hadronic Shower Development in Iron-Scintillator Tile Calorimetry

    CERN Document Server

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

    2000-01-01

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

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

    International Nuclear Information System (INIS)

    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''

  11. Applications of Immersion Calorimetry in Dubinin’s Theory and Electrochemistry

    OpenAIRE

    Stoeckli, Fritz; Centeno, Teresa A.

    2008-01-01

    This study shows that immersion calorimetry is a useful technique which simplifies considerably the analysis of porosity and chemical nature of activated carbons. The characterization of activated carbons in the general theoretical framework of Dubinin's theory with its extensions to calorimetry and adsorption from solutions allows the identification of some key parameters for the performance of these materials in electrochemical capacitors.

  12. Front-End Electronics in calorimetry: from LHC to ILC

    International Nuclear Information System (INIS)

    This report summarizes the electronics developments for liquid argon calorimeter read-out at LHC and the development carried out in the framework of the CALICE collaboration for those of the future linear collider (ILC). It also includes chips designed for multi-anode photomultipliers (MaPMT) used in the OPERA experiment or on ATLAS luminometer, which also find applications in medical imaging. Started in the early 90's, the development for ATLAS calorimetry was extremely challenging in terms of readout speed, radiation tolerance and measurement accuracy. The high speed has required a new approach using current-sensitive preamplifiers instead of charge sensitive ones and the redefinition of noise performance in terms of ENI. The preamplifiers developed at Orsay and the monolithic shapers are described in Chapter 1, including considerations of digital filtering, which was a new technique in our field. Chapter 2 is dedicated to the calibration system, designed and built by Orsay, for which the high performance and accuracy necessitated in-depth studies. The 3. chapter closes the studies for ATLAS with a summary of the detector measurements which had to be carried out on the 200 000 channels in order to understand and model the detector and achieve everywhere the accuracy and uniformity at per-cent level. These developments for ATLAS ended in 2004, although parallel work was also carried out for the NA48 and DO calorimeters which are not detailed here. The next generation of collider will require a new generation of calorimeters, much more granular, referred to as 'imaging calorimetry' with embedded read-out electronics. The ASICs developed for this purpose in the framework of the CALICE collaboration are described in Chapter 4. They integrate all the functionalities of amplification, digitization and read-out making them complex 'System-On-Chip' circuits extremely efficient that find many other applications. A family of 3 chips reads out the Si-W electromagnetic

  13. Adiabatic calorimetry (RSST and VSP) tests with sodium acetate

    Energy Technology Data Exchange (ETDEWEB)

    Kirch, N.W.

    1993-09-01

    As requested in the subject reference, adiabatic calorimetry (RSST and VSP) tests have been performed with sodium acetate covering TOC concentrations from 3 to 7% with the following results: Exothermic activity noted around 200{degrees}C. Propagating reaction initiated at about 300{degrees}C. Required TOC concentration for propagation estimated at about 6 w% (dry mixture) or about 20 w% sodium acetate. Heat of reaction estimated to be 3.7 MJ per kg of sodium acetate (based on VSP test with 3 w% TOC and using a dry mixture specific heat of 1000 J kg{sup {minus}1} K{sup {minus}1}). Based upon the above results we estimate that a moisture content in excess of 14 w% would prevent a propagating reaction of a stoichiometric mixture of fuel and oxidizer ({approximately} 38 w% sodium acetate and {approximately}62 w% sodium nitrate). Assuming that the fuel can be treated as sodium acetate equivalent, and considering that the moisture content in the organic containing waste generally is believed to be in excess of 14 w%, it follows that the possibility of propagating reactions in the Hanford waste tanks can be ruled out.

  14. Study of Liquid Argon Dopants for LHC Hadron Calorimetry

    CERN Multimedia

    2002-01-01

    Hadron calorimetry based on the Liquid Argon Ionisation Chamber technique is one of the choice techniques for LHC-experimentation. A systematic study of the effect of selected dopants on Liquid Argon (LAr) will be carried out with the aim to achieve an improvement on: \\item (i)~``Fast Liquid Argon'' search and study of dopants to increase the drift velocity. It has been already shown that CH&sub4. added at a fraction of one percent increases the drift velocity by a factor of two or more. \\item (ii)~``Compensated Liquid Argon'' search and study of dopants to increase the response to densely ionising particles, resulting in improved compensation, such as photosensitive dopants. \\end{enumerate}\\\\ \\\\ Monitoring of the parameters involved in understanding the response of a calorimeter is essential. In case of doped LAr, the charge yield, the non-saturated drift velocity and the electron lifetime in the liquid should be precisely and simultaneously monitored as they all vary with the level of dopant concentrati...

  15. Applying fast calorimetry on a spent nuclear fuel calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Liljenfeldt, Henrik [Swedish Nuclear Fuel and Waste Management (Sweden); Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Uppsala Univ. (Sweden)

    2015-04-15

    Recently at Los Alamos National Laboratory, sophisticated prediction algorithms have been considered for the use of calorimetry for treaty verification. These algorithms aim to predict the equilibrium temperature based on early data and therefore be able to shorten the measurement time while maintaining good accuracy. The algorithms have been implemented in MATLAB and applied on existing equilibrium measurements from a spent nuclear fuel calorimeter located at the Swedish nuclear fuel interim storage facility. The results show significant improvements in measurement time in the order of 15 to 50 compared to equilibrium measurements, but cannot predict the heat accurately in less time than the currently used temperature increase method can. This Is both due to uncertainties in the calibration of the method as well as identified design features of the calorimeter that limits the usefulness of equilibrium type measurements. The conclusions of these findings are discussed, and suggestions of both improvements of the current calorimeter as well as what to keep in mind in a new design are given.

  16. Thermal Properties of Silk Fibroin Using Fast Scanning Calorimetry

    Science.gov (United States)

    Cebe, Peggy; Partlow, Benjamin; Kaplan, David; Wurm, Andreas; Zhuravlev, Evgeny; Schick, Christoph

    We performed fast scanning chip-based calorimetry of silk protein using the Mettler Flash DSC1. We suggest the methodology by which to obtain quantitative information on the very first scan to high temperature, including the melting endotherm of the beta pleated sheets. For proteins, this first scan is the most important one, because the crystalline secondary structural features, the beta pleated sheets, melt after the first heating and cannot be thermally reintroduced. To obtain high quality data, the samples must be treated to drying and enthalpy relaxation sequences. The heat flow rates in heating and cooling must be corrected for asymmetric heat loses. We evaluate methods to obtain an estimate of the sample mass, finally choosing internal calibration using the known heat capacity increment at the glass transition. We report that even heating at rates of 2000 K/s, thermal degradation of silk cannot be totally avoided, though it can be minimized. Using a set of nineteen samples, we successfully determine the liquid state heat capacity of silk as: Cpliquid (T) = (1.98 +0.06) J/gK + T (6.82 +1.4) x10-4 J/gK2. Methods for estimation of the sample mass will be presented and compared. National Science Foundation, Polymers Program DMR-1206010; DAAD; Tufts Faculty Supported Leave.

  17. Isothermal titration calorimetry: A thermodynamic interpretation of measurements

    International Nuclear Information System (INIS)

    Highlights: ► Literature review shows that many ITC utilizations are based on empirical rules. ► A proper and rigorous thermodynamic interpretation of heats of titration is proposed. ► Heats of titration are independent of the cell type using infinitesimal titrations. ► Heats of interaction between solutes require only two different titration runs. - Abstract: Isothermal titration calorimeters have been developed and in use since the 1960s and the number of applications based on empirical rules to use them steadily increases. In this paper a rigorous study of the physical interpretation of the titration heat and the thermodynamic framework underlying isothermal titration calorimetry are proposed. For infinitesimal titrations, the titration heat is independent of the cell type employed, and the interpretation of the titration heat depends on the titrant composition and on the experiment type. Moreover, for the study of the interaction between two solutes in solution, only a combination of two experiments is necessary, and the result is interpreted as the partial enthalpy of interaction at infinite dilution of the solute contained in the titrant solution.

  18. Applying fast calorimetry on a spent nuclear fuel calorimeter

    International Nuclear Information System (INIS)

    Recently at Los Alamos National Laboratory, sophisticated prediction algorithms have been considered for the use of calorimetry for treaty verification. These algorithms aim to predict the equilibrium temperature based on early data and therefore be able to shorten the measurement time while maintaining good accuracy. The algorithms have been implemented in MATLAB and applied on existing equilibrium measurements from a spent nuclear fuel calorimeter located at the Swedish nuclear fuel interim storage facility. The results show significant improvements in measurement time in the order of 15 to 50 compared to equilibrium measurements, but cannot predict the heat accurately in less time than the currently used temperature increase method can. This Is both due to uncertainties in the calibration of the method as well as identified design features of the calorimeter that limits the usefulness of equilibrium type measurements. The conclusions of these findings are discussed, and suggestions of both improvements of the current calorimeter as well as what to keep in mind in a new design are given.

  19. Novel investigation of enzymatic biodiesel reaction by isothermal calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Sotoft, Lene Fjerbaek, E-mail: lfj@kbm.sdu.dk [Institute of Chemical Engineering, Biotechnology and Environmental Technology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark); Westh, Peter [Department of Life Science and Chemistry, Roskilde University, PO Box 260, DK-4000 Roskilde (Denmark); Christensen, Knud V.; Norddahl, Birgir [Institute of Chemical Engineering, Biotechnology and Environmental Technology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M (Denmark)

    2010-03-30

    Isothermal calorimetry (ITC) was used to investigate solvent-free enzymatic biodiesel production. The transesterification of rapeseed oil with methanol and ethanol was catalyzed by immobilized lipase Novozym 435 at 40 {sup o}C. The aim of the study was to determine reaction enthalpy for the enzymatic transesterification and to elucidate the mass transfer and energetic processes taking place. Based on the measured enthalpy and composition change in the system, the heat of reaction at 40 {sup o}C for the two systems was determined as -9.8 {+-} 0.9 kJ/mole biodiesel formed from rapeseed oil and methanol, and -9.3 {+-} 0.7 kJ/mole when rapeseed oil and ethanol was used. Simple Michaelis-Menten kinetics was not an appropriate choice for describing the kinetics of this heterogeneous system. The experiments demonstrated the possibility of investigating complex reaction mixtures using ITC. Although it is possible to determine thermodynamic properties such as reaction enthalpy and reaction rate, the difficulty in actually measuring the true non-mass-transfer-limited reaction kinetics is exposed by the high time resolution of ITC.

  20. A microfabrication-based approach to quantitative isothermal titration calorimetry.

    Science.gov (United States)

    Wang, Bin; Jia, Yuan; Lin, Qiao

    2016-04-15

    Isothermal titration calorimetry (ITC) directly measures heat evolved in a chemical reaction to determine equilibrium binding properties of biomolecular systems. Conventional ITC instruments are expensive, use complicated design and construction, and require long analysis times. Microfabricated calorimetric devices are promising, although they have yet to allow accurate, quantitative ITC measurements of biochemical reactions. This paper presents a microfabrication-based approach to integrated, quantitative ITC characterization of biomolecular interactions. The approach integrates microfabricated differential calorimetric sensors with microfluidic titration. Biomolecules and reagents are introduced at each of a series of molar ratios, mixed, and allowed to react. The reaction thermal power is differentially measured, and used to determine the thermodynamic profile of the biomolecular interactions. Implemented in a microdevice featuring thermally isolated, well-defined reaction volumes with minimized fluid evaporation as well as highly sensitive thermoelectric sensing, the approach enables accurate and quantitative ITC measurements of protein-ligand interactions under different isothermal conditions. Using the approach, we demonstrate ITC characterization of the binding of 18-Crown-6 with barium chloride, and the binding of ribonuclease A with cytidine 2'-monophosphate within reaction volumes of approximately 0.7 µL and at concentrations down to 2mM. For each binding system, the ITC measurements were completed with considerably reduced analysis times and material consumption, and yielded a complete thermodynamic profile of the molecular interaction in agreement with published data. This demonstrates the potential usefulness of our approach for biomolecular characterization in biomedical applications. PMID:26655185

  1. Measuring the Kinetics of Molecular Association by Isothermal Titration Calorimetry.

    Science.gov (United States)

    Vander Meulen, Kirk A; Horowitz, Scott; Trievel, Raymond C; Butcher, Samuel E

    2016-01-01

    The real-time power response inherent in an isothermal titration calorimetry (ITC) experiment provides an opportunity to directly analyze association kinetics, which, together with the conventional measurement of thermodynamic quantities, can provide an incredibly rich description of molecular binding in a single experiment. Here, we detail our application of this method, in which interactions occurring with relaxation times ranging from slightly below the instrument response time constant (12.5s in this case) to as large as 600s can be fully detailed in terms of both the thermodynamics and kinetics. In a binding titration scenario, in the most general case an injection can reveal an association rate constant (kon). Under more restrictive conditions, the instrument time constant-corrected power decay following each injection is simply an exponential decay described by a composite rate constant (kobs), from which both kon and the dissociation rate constant (koff) can be extracted. The data also support the viability of this exponential approach, for kon only, for a slightly larger set of conditions. Using a bimolecular RNA folding model and a protein-ligand interaction, we demonstrate and have internally validated this approach to experiment design, data processing, and error analysis. An updated guide to thermodynamic and kinetic regimes accessible by ITC is provided. PMID:26794355

  2. Cure kinetics of epoxy matrix resin by differential scanning calorimetry

    Science.gov (United States)

    Cizmecioglu, M.; Gupta, A.

    1982-01-01

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

  3. Combined Forward Calorimetry Option for Phase II CMS Endcap Upgrade

    International Nuclear Information System (INIS)

    Traditionally, EM and HAD compartments are thought to be separate and are often optimized individually. However, it is possible to optimize a robust and economical combined calorimeter system for myriad physics objectives. By employing event-by-event compensation afforded by the dual-readout technique, we have shown that excellent jet performance can be attained with a longitudinally un-segmented calorimeter that is calibrated only with electrons. In addition, the linear hadronic energy scale renders complex off-line correction schemes unnecessary. The proposed replacement of the CMS EE and HE calorimeters with a single Combined Forward Calorimeter (CFC) shows excellent jet performance complemented by good EM object detection. In this paper, we give brief snapshots on basic design criteria, timing characteristics of Cherenkov and scintillation pulses, trigger generation criteria and performance under high radiation fields. Although CMS has recently chosen different technologies for its endcap calorimetry in Phase II, the concepts developed here are likely to remain valuable for some time to come

  4. Calorimetry at the international linear collider. From simulation to reality

    International Nuclear Information System (INIS)

    Calorimetry plays a crucial role in ongoing and upcoming high-energy physics experiments. To build a powerful calorimetric system with a performance tailored to the expected physics signatures, demands dedicated research and development of new readout technologies as well as dedicated reconstruction algorithms. The presented design of a calorimetric system which meets the high demands of precision physics at the future linear collider ILC, follows the paradigm of particle ow. Particle ow is a reconstruction principle that relies on a calorimetric system with high spatial granularity. In the detector optimisation process, the development of hardware and software are interlinked and cannot be judged independently. This thesis addresses two different aspects of detector optimisation, a test of the detector design against one example physics scenario and the development of a stable calibration procedure. In the rst part, a gauge-mediated Supersymmetry breaking scenario is used to test the design of the electromagnetic calorimeter in a full detector simulation study. The reconstruction of the neutralino properties, each decaying into a photon and a gravitino, requires a good energy resolution, as well as excellent position and angular resolution. The error bounds on the neutralino mass is strongly linked to the energy resolution, while the position and angular reconstruction of neutral particles is essential for the determination of the neutralino lifetime. The second part of this thesis focuses on the calibration procedure for a prototype of the hadron calorimeter. 7608 novel photodetectors are operated and tested in this prototype. They are exposed to beams of well de ned particle type and energy. The calibration is tested with a detailed study of electromagnetic showers inside the cubic-metre-sized prototype, with special attention paid towards the non-linearity correction. (orig.)

  5. Calorimetry at the international linear collider. From simulation to reality

    Energy Technology Data Exchange (ETDEWEB)

    Wattimena, Nanda

    2010-02-15

    Calorimetry plays a crucial role in ongoing and upcoming high-energy physics experiments. To build a powerful calorimetric system with a performance tailored to the expected physics signatures, demands dedicated research and development of new readout technologies as well as dedicated reconstruction algorithms. The presented design of a calorimetric system which meets the high demands of precision physics at the future linear collider ILC, follows the paradigm of particle ow. Particle ow is a reconstruction principle that relies on a calorimetric system with high spatial granularity. In the detector optimisation process, the development of hardware and software are interlinked and cannot be judged independently. This thesis addresses two different aspects of detector optimisation, a test of the detector design against one example physics scenario and the development of a stable calibration procedure. In the rst part, a gauge-mediated Supersymmetry breaking scenario is used to test the design of the electromagnetic calorimeter in a full detector simulation study. The reconstruction of the neutralino properties, each decaying into a photon and a gravitino, requires a good energy resolution, as well as excellent position and angular resolution. The error bounds on the neutralino mass is strongly linked to the energy resolution, while the position and angular reconstruction of neutral particles is essential for the determination of the neutralino lifetime. The second part of this thesis focuses on the calibration procedure for a prototype of the hadron calorimeter. 7608 novel photodetectors are operated and tested in this prototype. They are exposed to beams of well de ned particle type and energy. The calibration is tested with a detailed study of electromagnetic showers inside the cubic-metre-sized prototype, with special attention paid towards the non-linearity correction. (orig.)

  6. Kinetics Characteristics of Nitrogen Hydrates Respond to Differential Scanning Calorimetry

    Science.gov (United States)

    Chen, Q.; Liu, C.; Ye, Y.; Gong, J.

    2012-12-01

    In this study, a high pressure differential scanning calorimetry (HP DSC) based on thermo-analytical technique was applied to investigate the kinetics and thermodynamics characteristics of nitrogen hydrates. Nitrogen hydrates was synthesized in the sample vessel under different pressures as temperature decreased from 293 to 233 K with a constant cooling rate of 0.2 K/min controlled by the DSC. To measure the hydrates dissociation enthalpies , the temperature was slowly raised up from 233 to 293 K at a constant rate ranging of 0.05 K/min. 1. Peak area on the heat flow curves represents the amount of heat during phase transition. In these experiments, the total water added to the sample vessel (mt) is already known. By integrating the peak areas of ice and hydrate, we know the total heats of ice (Qi) and hydrate (Qh), respectively. As the heat of ice per gram can be measured easily (336.366 J/g), the mass of ice (mi) can be obtain. Then, the dissociation heat of nitrogen hydrate per gram (Hh ) can be calculated by the equation: H(J/g)=Qh/(mt-mi) It is shown that the dissociation heats of nitrogen hydrates are a little larger than ice, but do not change a lot with different pressures. The average value of dissociation heat is 369.158 J/g. 2. During the DSC cooling stage, hydrate formed at temperature much lower than equilibrium. The biggest sub-cooling is about 291 K, while the smallest one is about 279 K. However, during these experiments, the pressure did not show obvious relationship with sub-cooling. It confirmed that even the proper conditions were achieved, formation was still a stochastic process. For one thing, due to the random distribution of dissolved gas in water, the interfacial tension and the water activity were not equal in the whole system. And if there was a free gas phase, which leads to different fugacity on water-gas interface, the stochastic behavior would be more significant in the sample vessel. 3. The energy released from hydrates formation as

  7. Uranium-liquid argon calorimetry: preliminary results from the DO tests

    International Nuclear Information System (INIS)

    The motivations for using uranium and liquid argon in sampling calorimetry are reviewed and the pros and cons of the technique are discussed. Preliminary results of the DO uranium-liquid argon test program are presented. 9 refs., 7 figs

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-12-31

    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''.

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

    Science.gov (United States)

    Muyskens, Mark A.

    1997-01-01

    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)

  10. A Study of Concept Mapping as an Instructional Intervention in an Undergraduate General Chemistry Calorimetry Laboratory

    Science.gov (United States)

    Stroud, Mary W.

    This investigation, rooted in both chemistry and education, considers outcomes occurring in a small-scale study in which concept mapping was used as an instructional intervention in an undergraduate calorimetry laboratory. A quasi-experimental, multiple-methods approach was employed since the research questions posed in this study warranted the use of both qualitative and quantitative perspectives and evaluations. For the intervention group of students, a convenience sample, post-lab concept maps, written discussions, quiz responses and learning surveys were characterized and evaluated. Archived quiz responses for non-intervention students were also analyzed for comparison. Students uniquely constructed individual concept maps containing incorrect, conceptually correct and "scientifically thin" calorimetry characterizations. Students more greatly emphasized mathematical relationships and equations utilized during the calorimetry experiment; the meaning of calorimetry concepts was demonstrated to a lesser extent.

  11. Relaxation process of Fe(CuNb)SiB amorphous alloys investigated by dynamical calorimetry

    International Nuclear Information System (INIS)

    Differential scanning calorimetry and dynamic differential scanning calorimetry were used to analyze the relaxation process of Fe(CuNb)SiB amorphous alloys. The Curie temperature (TC) evolution of the amorphous phase during relaxation as a function of heating rate, time and pre-annealing temperature were measured. Two distinct relaxation processes are observed, consequent with topological and chemical short range order changes. copyright 1997 American Institute of Physics

  12. Relaxation process of Fe(CuNb)SiB amorphous alloys investigated by dynamical calorimetry

    OpenAIRE

    Zhu, J.; Clavaguera-Mora, M. T.; Clavaguera, N.

    1997-01-01

    Differential scanning calorimetry and dynamic differential scanning calorimetry were used to analyze the relaxation process of Fe(CuNb)SiB amorphous alloys. The Curie temperature(TC) evolution of the amorphous phase during relaxation as a function of heating rate, time and pre-annealing temperature were measured. Two distinct relaxation processes are observed, consequent with topological and chemical short range order changes.

  13. INDIRECT CALORIMETRY IN THE ASSESSMENT OF THE ENERGY REQUIREMENT IN OVERWEIGHT AND OBESE WOMEN

    OpenAIRE

    Ewa Lange; Dominika Głąbska; Dariusz Włodarek

    2013-01-01

    Individual total energy expenditure may be calculated as a sum of basal energy requirement and energy expenditure associated with physical activity. Measurement of basal energy requirement is not often conducted in dietetic practice, but may be applied using indirect calorimetry. The aim of the analysis was to present the possibilities of using the Fitmate PRO monitor in the assessment of resting metabolic rate and basal energy expenditure with a method of indirect calorimetry in a group of 9...

  14. Methodology of hot nucleus calorimetry and thermometry produced by nuclear reactions around Fermi energies

    International Nuclear Information System (INIS)

    This work deals with the calorimetry and thermometry of hot nuclei produced in collisions Xe + Sn between 25 and 100 MeV/u. The apparatus for hot nucleus physical characterization is the 4π detector array Indra. This study was made by using the event generators Gemini, Simon and Hipse and a data-processing filter simulating the complete operation of the multi-detector. The first chapter presents the different ways of producing hot nuclei. In the second and third chapters, the author presents a critical methodological study of calorimetry and thermometry applied to hot nuclei, different methods are reviewed, their accuracy and application range are assessed. All the calorimetry methods rely on the assumption that we are able to discriminate decay products of the hot nucleus from evaporated particles. In the fourth chapter, the author gives some ways of improving calorimetry characterization of the hot nucleus. An alternative method of calorimetry is proposed in the fifth chapter, this method is based on the experimental determination of an evaporation probability that is deduced from the physical characteristics of the particles present in a restricted domain of the space of velocities

  15. Evaluation of the amorphous content of lactose by solution calorimetry and Raman spectroscopy.

    Science.gov (United States)

    Katainen, Erja; Niemelä, Pentti; Harjunen, Päivi; Suhonen, Janne; Järvinen, Kristiina

    2005-11-15

    Solution calorimetry can be used to determine the amorphous content of a compound when the solubility and dissolution rate of the compound in the chosen solvent are reasonably high. Sometimes, it can be difficult find a solvent in which a sample is freely soluble. The present study evaluated the use of solution calorimetry for the assessment of the amorphous content of a sample that is poorly soluble in a solvent. Physical mixtures of lactose and spray-dried lactose samples (the amorphous content varied from 0 to 100%) were analyzed by a solution calorimeter and the results were compared with Raman spectroscopy determinations. The heat of solvation of the samples was determined by solution calorimetry in organic solvents MeOH, EtOH, ACN, THF, acetone (400mg sample/100ml solvent). Lactose is virtually insoluble in ACN, THF and acetone and very slightly soluble in EtOH and MeOH. The amorphous content of the samples could not be determined by solution calorimetry in EtOH, ACN, THF or acetone. However, an excellent correlation was observed between the heat of solvation and the amorphous content of the samples in MeOH. Furthermore, the heat of solvation values of the samples in MeOH showed a linear correlation with the Raman quantifications. Therefore, our results demonstrate that solution calorimetry may represent a rapid and simple method for determining the amorphous content also in samples that are not freely soluble in the solvent. PMID:18970276

  16. Engineering design of dosimeter prototype based on graphite calorimetry for electron radiation dose measurement

    International Nuclear Information System (INIS)

    he engineering design of a dosimeter prototype based on graphite calorimetry for electron radiation dose measurement at electron energy of at most 300 keV and maximum dose of 60 kGy have been carried out. The graphite core is a cylinder shape with diameter and thickness of 30 mm and 2 mm respectively, surrounded by a guard ring made of the same graphite material. Dosimeter based on graphite calorimetry is equipped with a styrofoam for thermal insulation, temperature sensors and instrumentation based on micro controller. The characteristics of dosimeter based on graphite calorimetry are obtained by means of calculation and computer simulations using Penelope 2003 software and ANSYS computer program. The dosimeter based on graphite calorimetry has been designed to perform real time measurement of the average of absorbed and surface dose, it was expected that dosimeter based on graphite calorimetry can operate well. Compared with the cellulose tri acetate (CTA) dose measurement it gives relative differences of 18.9% and 9.1% at the experiments of energy variation and electron beam current alteration of the electron beam machine (EBM) respectively. (author

  17. Optical fibre temperature sensor technology and potential application in absorbed dose calorimetry

    International Nuclear Information System (INIS)

    Optical fibre based sensors are proposed as a potential alternative to the thermistors traditionally used as temperature sensors in absorbed dose calorimetry. The development of optical fibre temperature sensor technology over the last ten years is reviewed. The potential resolution of various optical techniques is assessed with particular reference to the requirements of absorbed dose calorimetry. Attention is drawn to other issues which would require investigation before the development of practical optical fibre sensors for this purpose could occur. 192 refs., 5 tabs., 4 figs

  18. Temperature-modulated differential scanning calorimetry as a specific heat spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Carpentier, L.; Descamps, M. [Laboratoire de Dynamique et Structures des Materiaux Moleculaires, ESA CNRS 8024, Universite de Lille, Villeneuve d' Ascq (France)]. E-mails: Marc.Descamps@univ-lille1.fr; Laurent.Carpentier@univ-lille1.fr; Bustin, O. [Laboratoire de Dynamique et Structures des Materiaux Moleculaires, ESA CNRS 8024, Universite de Lille, Villeneuve d' Ascq (France)

    2002-02-21

    The ability of modulated differential scanning calorimetry (MDSC) technique to perform a specific heat spectroscopy is examined by comparing MDSC results with those of alternating current calorimetry technique. The comparison is performed on three glass formers: glycerol, propylene glycol and salol. Both techniques give rise to similar activation energies, fragility index m and non-exponential parameters {beta} for the different compounds. It shows the relevance of the MDSC technique in providing a convenient laboratory probe of the molecular mobility. MDSC data are also compared with available dielectric results. This allows a check on the consistency of the results with regard to the differences between calorimetric and dielectric analysis. (author)

  19. Temperature-modulated differential scanning calorimetry as a specific heat spectroscopy

    Science.gov (United States)

    Carpentier, L.; Bustin, O.; Descamps, M.

    2002-02-01

    The ability of modulated differential scanning calorimetry (MDSC) technique to perform a specific heat spectroscopy is examined by comparing MDSC results with those of alternating current calorimetry technique. The comparison is performed on three glass formers: glycerol, propylene glycol and salol. Both techniques give rise to similar activation energies, fragility index m and non-exponential parameters β for the different compounds. It shows the relevance of the MDSC technique in providing a convenient laboratory probe of the molecular mobility. MDSC data are also compared with available dielectric results. This allows a check on the consistency of the results with regard to the differences between calorimetric and dielectric analysis.

  20. Temperature-modulated differential scanning calorimetry as a specific heat spectroscopy

    International Nuclear Information System (INIS)

    The ability of modulated differential scanning calorimetry (MDSC) technique to perform a specific heat spectroscopy is examined by comparing MDSC results with those of alternating current calorimetry technique. The comparison is performed on three glass formers: glycerol, propylene glycol and salol. Both techniques give rise to similar activation energies, fragility index m and non-exponential parameters β for the different compounds. It shows the relevance of the MDSC technique in providing a convenient laboratory probe of the molecular mobility. MDSC data are also compared with available dielectric results. This allows a check on the consistency of the results with regard to the differences between calorimetric and dielectric analysis. (author)

  1. Analysis of calorimetry in ultra relativistic heavy ion collisions at 200 GeV per nucleon

    International Nuclear Information System (INIS)

    We draw up in this thesis the statement of the calorimetry analysis in ultra relativistic heavy ion collisions at 200 GeV/A. NA38 experiment studies the production of dimuons correlated with neutral transverse energy flow detected by an electromagnetic calorimeter. J/Ψ suppression in central collisions could be a signature of the quark-gluon plasma (Q.G.P.). Characteristics and limits of the apparatus are briefly described. On the other hand, calorimetry measurements and analysis methods are studied in details and future developments are proposed

  2. Detection of sunflower oil in extra virgin olive oil by fast differential scanning calorimetry

    NARCIS (Netherlands)

    Wetten, I.A.; Herwaarden, A.W.; Splinter, R.; Boerrigter-Eenling, R.; Ruth, van S.M.

    2015-01-01

    Extra virgin olive oil (EVOO) is an economically valuable product, due to its high quality and premium price. Therefore it is vulnerable for adulteration by means of the addition of cheaper vegetable oils. Differential scanning calorimetry (DSC) has been suggested as a fast technique for the detecti

  3. Differential Scanning Calorimetry for Determining the Thermodynamic Properties of Selected Honeys

    OpenAIRE

    Tomaszewska-Gras Jolanta; Bakier Sławomir; Goderska Kamila; Mansfeld Krzysztof

    2015-01-01

    Thermodynamic properties of selected honeys: glass transition temperature (Tg), the change in specifi c heat capacity (ΔCp), and enthalpy (ΔH) were analysed using differential scanning calorimetry (DSC) in relation to the composition i.e. water and sugar content. Glass transition temperatures (Tg) of various types of honey differed significantly (p

  4. Isothermal titration calorimetry (ITC) study of surfactants and thermoresponsive poly-oxazolines

    Czech Academy of Sciences Publication Activity Database

    Bogomolova, Anna; Filippov, Sergey K.; Starovoytova, Larisa; Sedláček, Ondřej; Macková, Hana; Hrubý, Martin; Štěpánek, Petr

    Pisa : European Polymer Federation, 2013. P6-13. [European Polymer Congress - EPF 2013. 16.06.2013-21.06.2013, Pisa] Grant ostatní: AV ČR(CZ) M200501201 Institutional support: RVO:61389013 Keywords : isothermal titration calorimetry (ITC) * poly-oxyzolines Subject RIV: CD - Macromolecular Chemistry

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    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...

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

    International Nuclear Information System (INIS)

    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

  8. Thermodynamic profiling of Peptide membrane interactions by isothermal titration calorimetry: a search for pores and micelles

    DEFF Research Database (Denmark)

    Henriksen, Jonas Rosager; Andresen, Thomas Lars

    2011-01-01

    mixed peptide-lipid micelles. We have investigated the mode of action of the antimicrobial peptide mastoparan-X using isothermal titration calorimetry (ITC) and cryo-transmission electron microscopy (cryo-TEM). The results show that mastoparan-X induces a range of structural transitions of POPC/POPG (3...

  9. Isothermal Titration Calorimetry and Macromolecular Visualization for the Interaction of Lysozyme and Its Inhibitors

    Science.gov (United States)

    Wei, Chin-Chuan; Jensen, Drake; Boyle, Tiffany; O'Brien, Leah C.; De Meo, Cristina; Shabestary, Nahid; Eder, Douglas J.

    2015-01-01

    To provide a research-like experience to upper-division undergraduate students in a biochemistry teaching laboratory, isothermal titration calorimetry (ITC) is employed to determine the binding constants of lysozyme and its inhibitors, N-acetyl glucosamine trimer (NAG[subscript 3]) and monomer (NAG). The extremely weak binding of lysozyme/NAG is…

  10. Gamma Polari-Calorimetry with SOI pixels for proposals at Extreme Light Infrastructure (ELI-NP)

    CERN Document Server

    Homma, Kensuke

    2015-01-01

    We introduce the concept of Gamma Polari-Calorimetry (GPC) dedicated for proposals at Extreme Light Infrastructure in the Romanian site (ELI-NP). A simulation study shows that an assembly of thin SOI pixel sensors can satisfy our requirements to GPC.

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

    Science.gov (United States)

    Greenbowe, Thomas J.; Meltzer, David E.

    2003-01-01

    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…

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

    Science.gov (United States)

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

    1971-01-01

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

  13. Simulating SiD Calorimetry: Software Calibration Procedures and Jet Energy Resolution

    OpenAIRE

    Cassell, Ron

    2009-01-01

    Simulated calorimeter performance in the SiD detector is examined. The software calibration procedures are described, as well as the perfect pattern recognition PFA reconstruction. Performance of the SiD calorimeters is summarized with jet energy resolutions from calorimetry only, perfect pattern recognition and the SiD PFA algorithm. Presented at LCWS08[1].

  14. National absorbed dose to water references for radiotherapy medium energy X-rays by water calorimetry

    International Nuclear Information System (INIS)

    LNE-LNHB current references for medium energy X-rays are established in terms of air kerma. Absorbed dose to water, which is the quantity of interest for radiotherapy, is obtained by transfer dosimetric techniques following a methodology described in international protocols. The aim of the thesis is to establish standards in terms of absorbed dose to water in the reference protocol conditions by water calorimetry. The basic principle of water calorimetry is to measure the absorbed dose from the rise in temperature of water under irradiation. A calorimeter was developed to perform measurements at a 2 cm depth in water according to IAEA TRS-398 protocol for medium energy x-rays. Absorbed dose rates to water measured by calorimetry were compared to the values established using protocols based on references in terms of air kerma. A difference lower than 2.1% was reported. Standard uncertainty of water calorimetry being 0.8%, the one associated to the values from protocols being around 3.0%, results are consistent considering the uncertainties. Thanks to these new standards, it will be possible to use IAEA TRS-398 protocol to determine absorbed dose to water: a significant reduction of uncertainties is obtained (divided by 3 by comparison with the application of the IAEA TRS-277 protocol). Currently, none of the counterparts' laboratories own such an instrument allowing direct determination of standards in the reference conditions recommended by the international radiotherapy protocols. (author)

  15. Comparison of calorimetry and destructive analytical measurement techniques for excess plutonium powders

    International Nuclear Information System (INIS)

    In Dec. 1994, IAEA safeguards were initiated on inventory of Pu- bearing materials, originating from the US nuclear weapons complex, at vault 3 of DOE's Plutonium Finishing Plant at Hanford. Because of the diversity and heterogeneity of the Pu, plant operators have increasingly used calorimetry for accountability measurements. During the recent commencement of IAEA safeguards at vault 3, destructive (electrochemical titration) methods were used to determine Pu concentrations in subsamples of inventory items with widely ranging chemical purities. The Pu concentrations in the subsamples were determined and contribution of heterogeneity to total variability was identified. Measurement results, gathered by PFP and IAEA laboratories, showed total measurement variability for calorimetry to be comparable with or lower than those of sampling and chemical analyses

  16. Thermal characterization of starch-water system by photopyroelectric technique and adiabatic scanning calorimetry

    Science.gov (United States)

    Cruz-Orea, A.; Bentefour, E. H.; Jamée, P.; Chirtoc, M.; Glorieux, C.; Pitsi, G.; Thoen, J.

    2003-01-01

    Starch is one of the most important carbohydrate sources in human nutrition. For the thermal analysis of starch, techniques such as differential scanning calorimetry have been extensively used. As an alternative, we have applied a photopyroelectric (PPE) configuration and adiabatic scanning calorimetry (ASC) to study the thermal properties of starch-water systems. For this study we used nixtamalized corn flour and potato starch with different quantities of distilled water, in order to obtain samples with different moisture content. By using PPE and ASC methods we have measured, for each technique separately, the heat capacity by unit volume (ρcp) at room temperature for a corn flour sample at 90% moisture. The obtained values agree within experimental uncertainty. By using these techniques we also studied the thermal behavior of potato starch, at 80% moisture, in the temperature range where phase transitions occur. In this case the PPE signal phase could be used as a sensitive and versatile monitor for phase transitions.

  17. Characterization of the phase transformations in shape-memory alloys by modulated differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Z.G.; Sandstroem, R. [Royal Inst. of Technol., Stockholm (Sweden). Dept. of Materials Science and Engineering

    1999-12-15

    Modulated differential scanning calorimetry (MDSC) is a recently developed calorimetric technique, which has demonstrated some significant advantages over the conventional differential scanning calorimetry (DSC). By separating the reversing quantity from the non-reversing component in the total thermal events, it provides some new information that can not be obtained from the conventional DSC. The technique has been applied to various polycrystalline and single crystalline shape-memory alloys, including Cu-Zn-Al, Cu-Al-Ni, Ti-Ni(Cu), Ni-Mn-Ga and Fe-Mn-Si, to characterize the martensitic transformations, bainitic transformation, chemical and magnetic ordering transitions, atomic reordering and other kinetic relaxation processes in the alloys. The preliminary results of the MDSC measurements are summarized and the interpretation of the MDSC results and some factors affecting the results are discussed. (orig.)

  18. Characterization of the phase transformations in shape-memory alloys by modulated differential scanning calorimetry

    International Nuclear Information System (INIS)

    Modulated differential scanning calorimetry (MDSC) is a recently developed calorimetric technique, which has demonstrated some significant advantages over the conventional differential scanning calorimetry (DSC). By separating the reversing quantity from the non-reversing component in the total thermal events, it provides some new information that can not be obtained from the conventional DSC. The technique has been applied to various polycrystalline and single crystalline shape-memory alloys, including Cu-Zn-Al, Cu-Al-Ni, Ti-Ni(Cu), Ni-Mn-Ga and Fe-Mn-Si, to characterize the martensitic transformations, bainitic transformation, chemical and magnetic ordering transitions, atomic reordering and other kinetic relaxation processes in the alloys. The preliminary results of the MDSC measurements are summarized and the interpretation of the MDSC results and some factors affecting the results are discussed. (orig.)

  19. Correlative assay of uranium with calorimetry, neutron counting, and mass spectrometry data

    International Nuclear Information System (INIS)

    A methodology has been developed for assaying unirradiated enriched uranium that uses calorimetry, passive neutron counting, and historical mass spectrometry data. Calorimetry can be used to measure the thermal power of bulk uranium enriched in the isotope 235U, and neutron counting can be used to determine its spontaneous-fission neutron emission rate. The thermal power and neutron-emission properties of uranium change in a regular way with increasing 235U enrichment that can be quantified using mass spectrometry data. The measured ratio of the thermal power and spontaneous neutron fission rate can be used to determine the 235U enrichment and the total mass of the 234U, 235U, and 238U isotopes

  20. Modulated Temperature Differential Scanning Calorimetry Theoretical and Practical Applications in Polymer Characterisation

    CERN Document Server

    Reading, Mike

    2006-01-01

    MTDSC provides a step-change increase in the power of calorimetry to characterize virtually all polymer systems including curing systems, blends and semicrystalline polymers. It enables hidden transitions to be revealed, miscibility to be accurately assessed, and phases and interfaces in complex blends to be quantified. It also enables crystallinity in complex systems to be measured and provides new insights into melting behaviour. All of this is achieved by a simple modification of conventional DSC. In 1992 a new calorimetric technique was introduced that superimposed a small modulation on top of the conventional linear temperature program typically used in differential scanning calorimetry. This was combined with a method of data analysis that enabled the sample’s response to the linear component of the temperature program to be separated from its response to the periodic component. In this way, for the first time, a signal equivalent to that of conventional DSC was obtained simultaneously with a measure ...

  1. Kinetics of Enzymatic High-Solid Hydrolysis of Lignocellulosic Biomass Studied by Calorimetry

    DEFF Research Database (Denmark)

    Olsen, Søren Nymand; Rasmussen, Erik Lumby; McFarland, K.C.;

    2011-01-01

    Enzymatic hydrolysis of high-solid biomass (>10% w/w dry mass) has become increasingly important as a key step in the production of second-generation bioethanol. To this end, development of quantitative real-time assays is desirable both for empirical optimization and for detailed kinetic analysis....... In the current work, we have investigated the application of isothermal calorimetry to study the kinetics of enzymatic hydrolysis of two substrates (pretreated corn stover and Avicel) at high-solid contents (up to 29% w/w). It was found that the calorimetric heat flow provided a true measure of the...... hydrolysis rate with a detection limit of about 500 pmol glucose s−1. Hence, calorimetry is shown to be a highly sensitive real-time method, applicable for high solids, and independent on the complexity of the substrate. Dose–response experiments with a typical cellulase cocktail enabled a multidimensional...

  2. Application of isothermal calorimetry and uv spectroscopy for stability monitoring of pentaerythritol tetranitrate

    International Nuclear Information System (INIS)

    Thermal stabilities for a series of pentaerythritol-tetranitrate (PETN) samples with variable surf ace areas were monitored by isothermal calorimetry and UV spectroscopy over the temperature range of 363 to 408 K. Isothermal induction times measured with constant volume calorimetry under an air atmosphere and No evolution rates monitored by UV absorbance at 213 nm under vacuum correlated with the PETN surface area at temperatures equal to or exceeding 383 K. Rate data measured at 383 K are in accord with predictions based on detailed kinetic modeling. Below 383 K, NO evolution data suggested that additional geometric factors may be significant in controlling PETN stability. Mechanisms for influencing surface area upon the rate-determining step are addressed

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

    International Nuclear Information System (INIS)

    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

  4. Picosecond calorimetry

    DEFF Research Database (Denmark)

    Georgiou, Panayiotis; Vincent, Jonathan; Andersson, Magnus;

    2006-01-01

    Liquid phase time-resolved x-ray diffraction with 100 ps resolution has recently emerged as a powerful technique for probing the structural dynamics of transient photochemical species in solution. It is intrinsic to the method, however, that a structural signal is observed not only from the photo...

  5. Absolute dosimetry on a dynamically scanned sample for synchrotron radiotherapy using graphite calorimetry and ionization chambers.

    Science.gov (United States)

    Lye, J E; Harty, P D; Butler, D J; Crosbie, J C; Livingstone, J; Poole, C M; Ramanathan, G; Wright, T; Stevenson, A W

    2016-06-01

    The absolute dose delivered to a dynamically scanned sample in the Imaging and Medical Beamline (IMBL) on the Australian Synchrotron was measured with a graphite calorimeter anticipated to be established as a primary standard for synchrotron dosimetry. The calorimetry was compared to measurements using a free-air chamber (FAC), a PTW 31 014 Pinpoint ionization chamber, and a PTW 34 001 Roos ionization chamber. The IMBL beam height is limited to approximately 2 mm. To produce clinically useful beams of a few centimetres the beam must be scanned in the vertical direction. In practice it is the patient/detector that is scanned and the scanning velocity defines the dose that is delivered. The calorimeter, FAC, and Roos chamber measure the dose area product which is then converted to central axis dose with the scanned beam area derived from Monte Carlo (MC) simulations and film measurements. The Pinpoint chamber measures the central axis dose directly and does not require beam area measurements. The calorimeter and FAC measure dose from first principles. The calorimetry requires conversion of the measured absorbed dose to graphite to absorbed dose to water using MC calculations with the EGSnrc code. Air kerma measurements from the free air chamber were converted to absorbed dose to water using the AAPM TG-61 protocol. The two ionization chambers are secondary standards requiring calibration with kilovoltage x-ray tubes. The Roos and Pinpoint chambers were calibrated against the Australian primary standard for air kerma at the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). Agreement of order 2% or better was obtained between the calorimetry and ionization chambers. The FAC measured a dose 3-5% higher than the calorimetry, within the stated uncertainties. PMID:27192396

  6. Study of moisture structurization and binding form changes in pectin gels by differential scanning calorimetry

    OpenAIRE

    Крапивницька, Ірина Олексіївна; Потапов, Володимир Олексійович; Гурський, Петро Васильович; Перцевой, Федір Всеволодович

    2015-01-01

    During thermal cycling, changes in the structure and moisture-holding capacity of the samples of pectin gels with different formulations were investigated using differential scanning calorimetry by their cyclic heating and freezing.The fact that pectin gels are used for a wide variety of foods and semi-finished products, subjected to heat treatment in a wide temperature range from positive to negative was also taken into account during thermal cycling.The influence of the main formula compone...

  7. Nucleation and crystallisation kinetics of a Na-fluorrichterite based glass by differential scanning calorimetry (DSC)

    OpenAIRE

    Pérez, Juan M.; Casasola, Raquel; Rincón López, Jesús María; Romero, Maximina

    2012-01-01

    The present paper shows the results of a nucleation and crystallisation study of a Na-fluorrichterite glass carried out by dynamic scanning calorimetry (DSC). The kinetic study was performed using different procedures (Kissinger, Matusita–Sakka and Kissinger–Akahira–Sunose (KAS) methods), and the Avrami parameter was determined from the Ozawa and Malek approximations and the Malek equation. The results have indicated the coexistence of surface and bulk crystallisation in the devitrification p...

  8. Thermal Analysis (Differential Scanning Calorimetry And Thermogravimetric Analysis) Of SEBS Blends For Injection Molding

    OpenAIRE

    Juárez Varón, David; Ferrándiz Bou, Santiago; Peydro Rasero, Miguel Ángel; Sánchez Caballero, Samuel

    2013-01-01

    Thermal analysis (DSC: Differential Scanning Calorimetry and TGA: Thermogravimetric Analysis) of SEBS blends have been studied in this paper. SEBS blends were made using two transparent SEBS commercial grades with extreme hardness values. The first thermal property determined in SEBS blends was the evaluation of the thermal degradation at high temperatures (DSC). Another thermal property of the SEBS blends consists in knowing the degradation process of the blend (TGA). It should be emphasi...

  9. Monitoring of an RNA Multistep Folding Pathway by Isothermal Titration Calorimetry

    OpenAIRE

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

    2008-01-01

    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 lim...

  10. Application of calorimetry in evaluation of phase transformations in the selected hypoeutectic silumins

    Directory of Open Access Journals (Sweden)

    J. Szymszal

    2009-04-01

    Full Text Available The investigations of phase transformations described in this study were carried out on hypoeutectic alloys from the Al-Si during heating and cooling. The determination and analysis of characteristic temperature values from the solidification range was made by the DSC method in calorimetric investigations carried out on a high-temperature multi HTC Setaram scanning calorimeter. Applying the lever rule, the phase composition of the examined slumins was calculated and compared with the results of DSC calorimetry.

  11. Calorimetry of dehydrogenation and dangling-bond recombination in several hydrogenated amorphous silicon materials

    OpenAIRE

    Roura Grabulosa, Pere; Farjas Silva, Jordi; Rath, Chandana; Serra-Miralles, J.; Bertrán Serra, Enric; Roca I Cabarrocas, Pere

    2006-01-01

    Differential scanning calorimetry (DSC) was used to study the dehydrogenation processes that take place in three hydrogenated amorphous silicon materials: nanoparticles, polymorphous silicon, and conventional device-quality amorphous silicon. Comparison of DSC thermograms with evolved gas analysis (EGA) has led to the identification of four dehydrogenation processes arising from polymeric chains (A), SiH groups at the surfaces of internal voids (A'), SiH groups at interfaces (B), and in the b...

  12. Determination of the aggregation number for micelles by isothermal titration calorimetry

    DEFF Research Database (Denmark)

    Olesen, Niels Erik; Holm, Rene; Westh, Peter

    2014-01-01

    Isothermal titration calorimetry (ITC) has previously been applied to estimate the aggregation number (n), Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) of micellization. However, some difficulties of micelle characterization by ITC still remain; most micelles have aggregation numbers...... insight into optimal design of titration protocols for micelle characterization. By applying the new method, the aggregation number of sodium dodecyl sulphate and glycochenodeoxycholate was determined at concentrations around their critical micelle concentration (CMC)...

  13. Indirerect calorimetry in nowborn and post-weaning mice: methodological aspects

    Czech Academy of Sciences Publication Activity Database

    Janovská, Petra; Matějčková, Eva; Kůs, Vladimír; Kopecký, Jan

    Budapest, 2007. s. 27-27. [Pre-congress satellite meeting of the European congress on obesity /15./. 20.04.-21.04.2007, Budapest] R&D Projects: GA MŠk(CZ) 1M0520; GA ČR(CZ) GA303/05/2580 Institutional research plan: CEZ:AV0Z50110509 Keywords : energy expenditure * indirect calorimetry * early postnatal development Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  14. Irreversible Denaturation of Maltodextrin Glucosidase Studied by Differential Scanning Calorimetry, Circular Dichroism, and Turbidity Measurements

    OpenAIRE

    Goyal, Megha; Chaudhuri, Tapan K; Kuwajima, Kunihiro

    2014-01-01

    Thermal denaturation of Escherichia coli maltodextrin glucosidase was studied by differential scanning calorimetry, circular dichroism (230 nm), and UV-absorption measurements (340 nm), which were respectively used to monitor heat absorption, conformational unfolding, and the production of solution turbidity. The denaturation was irreversible, and the thermal transition recorded at scan rates of 0.5–1.5 K/min was significantly scan-rate dependent, indicating that the thermal denaturation was ...

  15. DIFFERENTIAL SCANNING CALORIMETRY NON-ISOTHERMAL THERMOXIDATIVE STUDY OF LOW DENSITY POLYETHYLENE FORMULATED WITH LIGNIN

    OpenAIRE

    Irama Piña-Saenz; Juan Chirinos-Colina; Fredy Ysambertt-Soto; Mónica Arias-Jimenez

    2012-01-01

    The antioxidant capacity of lignin (LLN) on low density polyethylene(LDPE) was studied by means of a non-isothermal method using differential scanning calorimetry (DSC). The samples under study, obtained by formulating LDPE with LLN, were subject of heat treatment at different heating rates ( = 1, 3, 5, 7, 10, 15, 20  C / min), under oxygen atmosphere to promote the thermo-oxidation of the material. A kinetic model of isoconversional termoxidative degradation, adjusted to the Arrhenius equ...

  16. Characterization of photomultiplier tubes in a novel secondary ionization mode for Secondary Emission Ionization Calorimetry

    CERN Document Server

    Tiras, E; Ogul, H; Southwick, D; Bilki, B; Nachtman, J; Onel, Y

    2016-01-01

    Hamamatsu single anode R7761 and multi-anode R5900-00-M16 Photomultiplier Tubes have been characterized for use in Secondary Emission Ionization Calorimetry study, that is a novel techique to measure the electromagnetic shower particles in extreme radiation environment. There are different SE modes used in the tests, developed from conventional PMT mode. Here, the technical design of secondary emission modules and characterization measurements of both SE modes and the PMT mode are reported.

  17. Absolute dosimetry on a dynamically scanned sample for synchrotron radiotherapy using graphite calorimetry and ionization chambers

    Science.gov (United States)

    Lye, J. E.; Harty, P. D.; Butler, D. J.; Crosbie, J. C.; Livingstone, J.; Poole, C. M.; Ramanathan, G.; Wright, T.; Stevenson, A. W.

    2016-06-01

    The absolute dose delivered to a dynamically scanned sample in the Imaging and Medical Beamline (IMBL) on the Australian Synchrotron was measured with a graphite calorimeter anticipated to be established as a primary standard for synchrotron dosimetry. The calorimetry was compared to measurements using a free-air chamber (FAC), a PTW 31 014 Pinpoint ionization chamber, and a PTW 34 001 Roos ionization chamber. The IMBL beam height is limited to approximately 2 mm. To produce clinically useful beams of a few centimetres the beam must be scanned in the vertical direction. In practice it is the patient/detector that is scanned and the scanning velocity defines the dose that is delivered. The calorimeter, FAC, and Roos chamber measure the dose area product which is then converted to central axis dose with the scanned beam area derived from Monte Carlo (MC) simulations and film measurements. The Pinpoint chamber measures the central axis dose directly and does not require beam area measurements. The calorimeter and FAC measure dose from first principles. The calorimetry requires conversion of the measured absorbed dose to graphite to absorbed dose to water using MC calculations with the EGSnrc code. Air kerma measurements from the free air chamber were converted to absorbed dose to water using the AAPM TG-61 protocol. The two ionization chambers are secondary standards requiring calibration with kilovoltage x-ray tubes. The Roos and Pinpoint chambers were calibrated against the Australian primary standard for air kerma at the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). Agreement of order 2% or better was obtained between the calorimetry and ionization chambers. The FAC measured a dose 3–5% higher than the calorimetry, within the stated uncertainties.

  18. A bipolar monolithic preamplifier for high-capacitance SSC [Superconducting Super Collider] silicon calorimetry

    International Nuclear Information System (INIS)

    This paper describes a preamplifier designed and fabricated specifically to address the requirements of silicon calorimetry for the Superconducting Super Collider (SSC). The topology and its features are discussed in addition to the design methodology employed. The simulated and measured results for noise, power consumption, and speed are presented. Simulated an measured data for radiation damage effects as well as data for post-damage annealing are also presented. 8 refs., 7 figs., 2 tabs

  19. Immersion Calorimetry for the Characterization of PD Catalysts Supported on Activated Carbon

    OpenAIRE

    Liliana Giraldo; Juan Carlos Moreno-Piraján

    2009-01-01

    Activated carbons obtained from coconut peel were oxidized using hydrogen peroxide. Superficial characteristics of these carbons were determined through N2 and CO2 isotherms and functional groups were characterized by TPD. Finally, the microcalorimetry technique was used in order to obtain the immersion enthalpies in diverse liquids and established the relation between them and the results obtained by the other characterization techniques. The results suggested that the immersion calorimetry ...

  20. An indirect calorimetry system for ventilator dependent very low birthweight infants.

    OpenAIRE

    Matthews, D S; Matthews, J. N.

    1992-01-01

    With neurodevelopmental outcome of very low birthweight (VLBW) infants being adversely affected by inadequate nutrition during the first few weeks of life, there is an urgent need for more specific nutritional data on the sick VLBW ventilator dependent infant. The development of a new mass spectrometry gas analysis indirect calorimetry system which is non-invasive and can operate over several hours or days is described. Technical evaluation of each of the components of the system indicates a ...

  1. Hydrocarbons adsorption on metal trimesate MOFs: Inverse gas chromatography and immersion calorimetry studies

    Energy Technology Data Exchange (ETDEWEB)

    Gutiérrez, Inés; Díaz, Eva; Vega, Aurelio [Department of Chemical and Environmental Engineering, University of Oviedo, Faculty of Chemistry, Julián Clavería s/n, 33006 Oviedo (Spain); Ordóñez, Salvador, E-mail: sordonez@uniovi.es [Department of Chemical and Environmental Engineering, University of Oviedo, Faculty of Chemistry, Julián Clavería s/n, 33006 Oviedo (Spain); Guerrero-Ruiz, Antonio [Department of Inorganic and technical Chemistry, UNED, 28040 Madrid (Spain); Castillejos-López, Eva; Rodríguez-Ramos, Inmaculada [Instituto de Catálisis y Petroleoquímica, CSIC, Madrid (Spain)

    2015-02-20

    Highlights: • Inverse gas chromatography and immersion calorimetry were compared on two MOFs. • Adsorption of seven carbon atoms adsorbates on Cu{sub 3}(BTC){sub 2} and Fe(BTC) was performed. • Size and polarizability of adsorbates are decisive in the strength of adsorption. • Dispersive interaction of surface free energy depends on the surface area. • I{sup sp} is influenced by the chemistry of adsorbates and morphology of the adsorbents. - Abstract: Two commercial metal-organic frameworks, Cu{sub 3}(BTC){sub 2} and Fe(BTC), have been selected to compare the adsorption parameters obtained on these materials by two different techniques: immersion calorimetry and inverse gas chromatography (IGC), in order to find a relationship between thermodynamic parameters obtained by so different techniques. From comparison between the enthalpy of adsorption obtained from IGC and the enthalpy of immersion, three molecules of the same number of carbon atoms have been selected: n-heptane, methylcyclohexane and toluene. Both by IGC and immersion calorimetry, the interaction is stronger in Fe(BTC), being the aromaticity of TOL determinant in the strength of the interaction. However, splitting of the enthalpy of adsorption into the dispersive and specific components allows to deduce that both parameters are more important on the Cu{sub 3}(BTC){sub 2}, due to the higher available surface area in the case of the dispersive interaction; and for the specific interaction, due to the high potential of interaction into the micropores.

  2. Hydrocarbons adsorption on metal trimesate MOFs: Inverse gas chromatography and immersion calorimetry studies

    International Nuclear Information System (INIS)

    Highlights: • Inverse gas chromatography and immersion calorimetry were compared on two MOFs. • Adsorption of seven carbon atoms adsorbates on Cu3(BTC)2 and Fe(BTC) was performed. • Size and polarizability of adsorbates are decisive in the strength of adsorption. • Dispersive interaction of surface free energy depends on the surface area. • Isp is influenced by the chemistry of adsorbates and morphology of the adsorbents. - Abstract: Two commercial metal-organic frameworks, Cu3(BTC)2 and Fe(BTC), have been selected to compare the adsorption parameters obtained on these materials by two different techniques: immersion calorimetry and inverse gas chromatography (IGC), in order to find a relationship between thermodynamic parameters obtained by so different techniques. From comparison between the enthalpy of adsorption obtained from IGC and the enthalpy of immersion, three molecules of the same number of carbon atoms have been selected: n-heptane, methylcyclohexane and toluene. Both by IGC and immersion calorimetry, the interaction is stronger in Fe(BTC), being the aromaticity of TOL determinant in the strength of the interaction. However, splitting of the enthalpy of adsorption into the dispersive and specific components allows to deduce that both parameters are more important on the Cu3(BTC)2, due to the higher available surface area in the case of the dispersive interaction; and for the specific interaction, due to the high potential of interaction into the micropores

  3. Investigation of lipid membrane macro- and micro-structure using calorimetry and computer simulation: structural and functional relationships

    DEFF Research Database (Denmark)

    Jørgensen, Kent; Mouritsen, Ole G.

    1999-01-01

    The lipid bilayer part of biological membranes is a complex lipid mixture displaying cooperative phenomena. By means of differential scanning calorimetry and computer simulation techniques, the equilibrium and non-equilibrium properties of the large assembly of mutually interacting amphiphilic...

  4. Performance Test of High Heat Flux Test Facility for the Calorimetry and Beam Control

    International Nuclear Information System (INIS)

    The Korea Heat Load Test facility, KoHLT-EB (Electron Beam) has been operating for the plasma facing components to develop fusion engineering in Korea. The ITER Neutral Beam Duct Liner (NBDL) was fabricated and tested to qualify the thermocouple fixation method for the temperature measurement during a direct collision of the high-power neutral beam during ITER operation. The NBDL is CuCrZr panels, which are actively water cooled using deep drilled channels. To perform the profile test, the assessment for the possibility of an electron beam Gaussian power density profile and the result of absorbed power for that profile before the test start is needed. To assess the possibility of Gaussian profile, for the qualification test of a Gaussian heat load profile, small calorimetry was manufactured to simulate a real heat profile in the neutral beam duct liner, and this calorimetry has two cooling channel with five thermocouples, which is the same as NBDL. Preliminary analyses with ANSYSCFX using a 3D model were performed with the calorimetry model. The heating area was modeled to be 60 mm x 250 mm. The simulated heat flux is 0.5 - 1.2 MW/m''2 at 0.75 kg/sec of the water flow rate. A steady heat flux test was performed to measure the surface heat flux, surface temperature profile. With a thermohydraulic analysis and heat load test, the Gaussian heat profile will be confirmed for this calorimetry and NBDL mockup. The Korean heat load test facility will be used to qualify the specifications of various plasma facing components in fusion devices. To conduct a beam profile test, an assessment of the possibility of electron beam Gaussian power density profile and the results of the absorbed power for that profile before the test starts are needed. To assess the possibility of a Gaussian profile, for the qualification test of the Gaussian heat load profile, a calorimeter mockup and large Cu module were manufactured to simulate real heat. For this high-heat flux test

  5. Determination of Energy Characteristic and Microporous Volume by Immersion Calorimetry in Carbon Monoliths

    OpenAIRE

    Moreno-Piraján, Juan Carlos; Giraldo, Liliana; Vargas, Diana P.

    2012-01-01

    Activated carbon monoliths disc and honeycomb type were prepared by chemical activation of coconut shell with zinc chloride at different concentrations, without using a binder. The structures were characterized by N2 adsorption at 77 K and immersion calorimetry into benzene. The experimental results showed that the activation with zinc chloride produces a wide microporous development, with micropore volume between 0,38 and 0,79 cm3g-1, apparent BET surface area between 725 and 1523 m2g-1 and ...

  6. Development of Temperature Measurements and Calorimetry for the Neutral Beam Test Stand Operation at KAERI

    International Nuclear Information System (INIS)

    Operation of the Neutral Beam Test Stand(NB-TS) at Korea Atomic Energy Research Institute(KAERI) now reaches to 80 kV-20A for about 10 seconds. Experiments with this kind of enormous power and energy necessarily entail many temperature measurements at various locations of the system, and most of the beam line components require to be monitored of their temperatures. We have been implementing temperature measurement utilizing K-Type and T-Type thermocouples(TCs) and a Pt-100 resistance temperature detector for the instrumentation and control and for establishing calorimetry during the operation of the NB-TS facility

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

    Energy Technology Data Exchange (ETDEWEB)

    Adloff, C.; Chefdeville, M., E-mail: chefdevi@lapp.in2p3.fr; Dalmaz, A.; Drancourt, C.; Gaglione, R.; Geffroy, N.; Jacquemier, J.; Karyotakis, Y.; Koletsou, I.; Peltier, F.; Samarati, J.; Vouters, G.

    2014-11-01

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

  8. Isothermal titration calorimetry with micelles: Thermodynamics of inhibitor binding to carnitine palmitoyltransferase 2 membrane protein ☆

    OpenAIRE

    Perspicace, Samantha; Rufer, Arne C.; Thoma, Ralf; Mueller, Francis; Hennig, Michael; Ceccarelli, Simona; Schulz-Gasch, Tanja; Seelig, Joachim

    2013-01-01

    Carnitine palmitoyl transferase 2 (CPT-2) is a key enzyme in the mitochondrial fatty acid metabolism. The active site is comprised of a Y-shaped tunnel with distinct binding sites for the substrate acylcarnitine and the cofactor CoA. We investigated the thermodynamics of binding of four inhibitors directed against either the CoA or the acylcarnitine binding sites using isothermal titration calorimetry (ITC). CPT-2 is a monotopic membrane protein and was solubilized by β-octylglucoside (β-OG) ...

  9. Water flow calorimetry measurements of heat loads for a volume production H- source

    International Nuclear Information System (INIS)

    The design of volume-production H- sources requires the knowledge of heat loads on the source components. The arc and filament heater power input to a 20 cm diameter x 23 cm long source can be 50 kW or higher, practically all of which is absorbed in the cooling water. Water flow calorimetry measurements were made to determine the heat loads on the bucket walls, grid no. 1, and magnetic filter rods. The measurements are presented for two different filament locations, for three different values of arc power, and for three values of source gas pressure. 1 ref., 4 figs., 2 tabs

  10. High-pressure ionization chambers for calorimetry in high-energy physics

    International Nuclear Information System (INIS)

    Measurements have been made with alpha particles in pure argon gas at pressures of up to 100 atm with only a 20% reduction in pulse height. Some of this is attributable to recombination at high pressures. With the addition of 0.2% methane and with an electric field of 1 kV/mm, the drift velocity of the electrons was 55 ns/mm. The objective is to produce a calorimeter that is fast, radiation hard, and free of the problems caused by scattered neutrons in low-pressure gas calorimetry

  11. Titration Calorimetry Applied to the Thermokinetics Study of Consecutive First-order Reactions

    Institute of Scientific and Technical Information of China (English)

    SHI Jing-Yan; LI Jie; WANG Zhi-Yong; LIU Yu-Wen; WANG Cun-Xin

    2008-01-01

    The thermokinetic mathematical models for consecutive first-order reactions in titration period and the stopped-titration reaction period were proposed for titration calorimetry, based on which, thermodynamic parameters (reaction enthalpies, △rHm1 and △rHm2) and kinetic parameters (rate constants, k1 and k2) of the consecutive first-order reactions could be obtained by directly simulating the calorimetric curve from a single experiment with the method of nonlinear least squares regression (NLLS).The reliability of the model has been verified by investigating the reaction of the saponification of diethyl succinate in an aqueous ethanol solvent.

  12. Water flow calorimetry measurements of heat loads for a volume production H- source

    International Nuclear Information System (INIS)

    The design of volume-production H- sources requires the knowledge of heat loads on the source components. The arc and filament heater power input to a 20 cm diameter x 23 cm long source can be 50 kW or higher, practically all of which is absorbed in the cooling water. Water flow calorimetry measurements were made to determine the heat loads on the bucket walls, grid no. 1, and magnetic filter rods. The measurements are presented for two different filament locations, for three different values of arc power, and for three values of source gas pressure

  13. Denaturation processes in gamma irradiated proteins studied by differential scanning calorimetry

    International Nuclear Information System (INIS)

    Differential scanning calorimetry was applied to study the influence of gamma irradiation on the process of denaturation of proteins, occurring in water suspensions during heating. Irradiations of solid native samples and of water suspensions of the selected globular proteins were performed in air atmosphere at ambient temperature or in solid CO2, by applying 20-30 kGy, 3 kGy and 2.5 kGy doses. A decrease of peak and onset temperatures, broadening of the denaturation endothermal effects, as well as a decline in denaturation enthalpy was observed as a result of irradiation

  14. Resistive Micromegas for sampling calorimetry, a study of charge-up effects

    Science.gov (United States)

    Chefdeville, M.; Karyotakis, Y.; Geralis, T.; Titov, M.

    2016-07-01

    Micromegas, as a proportional and compact gaseous detector, is well suited for sampling calorimetry. The limitation of occasional sparking has now been lifted by means of resistive electrodes but at the cost of current-dependent charge-up effects. These effects are studied in this contribution, with an emphasis on gain variations during operation at high particle rate and under heavy ionisation. Results are reproduced by a simple model of charging-up which will be used for detector design optimisation in the future.

  15. Calorimetry in superfluid He II to measure losses in superconducting magnets

    International Nuclear Information System (INIS)

    A method using calorimetry to measure magnet losses in pressurized Helium II is described. The isothermal nature of He II is used in measuring the overall heat capacity of the system and the net refrigeration power. During the measurements, the refrigeration power is held fixed, and the system (400 liters) temperature is near 1.92 K. The calorimetric measurement was calibrated against known power inputs between 1 and 20 W. This technique can even measure heat loads higher than the available refrigeration. Results of loss measurement on two dipole magnets are reported

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

    International Nuclear Information System (INIS)

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

  17. Excess heat capacity of the (Li1−xCax)F1+x liquid solution determined by differential scanning calorimetry and drop calorimetry

    International Nuclear Information System (INIS)

    Highlights: • The heat capacity of the (Li1−xCax)F1+x liquid solution was measured. • A procedure for DSC was developed to measure heat capacity of encapsulated samples. • A significant excess heat capacity of (Li1−xCax)F1+x liquid solution was observed. - Abstract: The work presents the measured heat capacity of the (Li1−xCax)F1+x liquid solution. Four samples with different compositions have been prepared and measured using a Differential Scanning Calorimeter. Since this technique was newly adopted for measuring encapsulated fluoride samples, some modifications were introduced in the standard configuration of the instrument and they are described in this work as well. For comparison one of the analysed composition (xCaF2 = 0.5) was also measured using drop calorimetry, which has been previously used for similar studies. The reliability of the results obtained was confirmed by the good agreement between the two techniques. Moreover, the excess heat capacity of the (Li1−xCax)F1+x liquid solution was derived and a strong deviation from the ideal behaviour was observed

  18. Methodology of hot nucleus calorimetry and thermometry produced by nuclear reactions around Fermi energies; Methodologie de la calorimetrie et de la thermometrie des noyaux chauds formes lors de collisions nucleaires aux energies de Fermi

    Energy Technology Data Exchange (ETDEWEB)

    Vient, E

    2006-12-15

    This work deals with the calorimetry and thermometry of hot nuclei produced in collisions Xe + Sn between 25 and 100 MeV/u. The apparatus for hot nucleus physical characterization is the 4{pi} detector array Indra. This study was made by using the event generators Gemini, Simon and Hipse and a data-processing filter simulating the complete operation of the multi-detector. The first chapter presents the different ways of producing hot nuclei. In the second and third chapters, the author presents a critical methodological study of calorimetry and thermometry applied to hot nuclei, different methods are reviewed, their accuracy and application range are assessed. All the calorimetry methods rely on the assumption that we are able to discriminate decay products of the hot nucleus from evaporated particles. In the fourth chapter, the author gives some ways of improving calorimetry characterization of the hot nucleus. An alternative method of calorimetry is proposed in the fifth chapter, this method is based on the experimental determination of an evaporation probability that is deduced from the physical characteristics of the particles present in a restricted domain of the space of velocities.

  19. Gas phase enthalpies of formation of nitrobenzamides using combustion calorimetry and thermal analysis

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Formation enthalpies of the nitrobenzamides were derived from combustion calorimetry. • Enthalpies of vaporisation and sublimation were calculated by thermogravimetry. • From gas phase enthalpies of formation the stability of the isomers is studied. • Stability of isomers is not driven by a steric hindrance between functional groups. - Abstract: The standard molar energies of combustion of 2-nitrobenzamide, 3-nitrobenzamide and 4-nitrobenzamide were determined with an isoperibolic, static-bomb, combustion calorimeter. From the combustion results, the standard molar enthalpies of combustion and formation for these compounds in the condensed phase at T = 298.15 K were derived. Subsequently, to determine the enthalpies of sublimation, the vapour pressure data as a function of the temperature for the compounds under investigation were estimated using thermogravimetry by applying Langmuir’s equation, and the enthalpies of vaporisation were derived. Standard enthalpies of fusion were measured by differential scanning calorimetry then added to those of vaporisation to obtain reliable results for the enthalpy of sublimation. From the combustion and sublimation data, the gas phase enthalpies of formation were determined to be (−138.9 ± 3.5) kJ · mol−1, (−122.9 ± 2.9) kJ · mol−1 and (−108.5 ± 3.7) kJ · mol−1 for the ortho, meta and para isomers of nitrobenzamide, respectively. The meaning of these results with regard to the enthalpic stability of these molecular structures is discussed herein

  20. Technical memo on PbF2 as a Cherenkov radiator for EM calorimetry

    International Nuclear Information System (INIS)

    It is apparent that the ever increasing rates and radiation levels found in high-energy physics are excluding more and more instrumental techniques. Those techniques that are remaining are often pushed to their theoretical limits. This situation reaches an extreme at the proposed luminosity of the SSC. Also, it is fair to say that at the SSC, after the accelerator itself, calorimetry will be the next most important physics tool. Therefore, we should be ever alert to new calorimetry techniques which may operate in this demanding environment. The material lead fluoride, PbF2, has a real potential of yielding a very compact, high-resolution electromagnetic calorimeter that is both fast and radiation hard. PbF2 is not a scintillator but a Cherenkov radiator like lead glass, but with a radiation length even harder shorter than of BGO. This memo discusses this property as well as comparison PbF2 to other scintillating materials. 2 refs., 14 figs., 1 tab

  1. Hydrogen atom density in narrow-gap microwave hydrogen plasma determined by calorimetry

    Science.gov (United States)

    Yamada, Takahiro; Ohmi, Hiromasa; Kakiuchi, Hiroaki; Yasutake, Kiyoshi

    2016-02-01

    The density of hydrogen (H) atoms in the narrow-gap microwave hydrogen plasma generated under high-pressure conditions is expected to be very high because of the high input power density of the order of 104 W/cm3. For measuring the H atom density in such a high-pressure and high-density plasma, power-balance calorimetry is suited since a sufficient signal to noise ratio is expected. In this study, H atom density in the narrow-gap microwave hydrogen plasma has been determined by the power-balance calorimetry. The effective input power to the plasma is balanced with the sum of the powers related to the out-going energy per unit time from the plasma region via heat conduction, outflow of high-energy particles, and radiation. These powers can be estimated by simple temperature measurements using thermocouples and optical emission spectroscopy. From the power-balance data, the dissociation fraction of H2 molecules is determined, and the obtained maximum H atom density is (1.3 ± 0.2) × 1018 cm-3. It is found that the H atom density increases monotonically with increasing the energy invested per one H2 molecule within a constant plasma volume.

  2. Thermochemistry of some binary lead and transition metal compounds by high temperature direct synthesis calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Meschel, S.V., E-mail: meschel@jfi.uchicago.edu [Illinois Institute of Technology,Thermal Processing Technology Center, 10 W. 32nd Street, Chicago, Illinois 60615 (United States); Gordon Center for Integrated Science, 929 E. 57th Street, Chicago, Illinois 60637 (United States); Nash, P. [Illinois Institute of Technology,Thermal Processing Technology Center, 10 W. 32nd Street, Chicago, Illinois 60615 (United States); Chen, X.Q.; Wei, P. [Materials processing Modeling Division, Shenyang National Laboratory for Materials Science, Institute of Metals Research, 72 Wenhua Road, Shenyang City (China)

    2015-06-05

    Highlights: • Studied binary lead-transition metal alloys by high temperature calorimetry. • Determined the enthalpies of formation of 8 alloys. • Compared the measurements with predictions by the model of Miedema and by the ab initio method. - Abstract: The standard enthalpies of formation of some binary lead and transition metal compounds have been measured by high temperature direct synthesis calorimetry. The reported results are: Pb{sub 3}Sc{sub 5}(−61.3 ± 2.9); PbTi{sub 4}(−16.6 ± 2.4); Pb{sub 3}Y{sub 5}(−64.8 ± 3.6); Pb{sub 3}Zr{sub 5}(−50.6 ± 3.1); PbNb{sub 3}(−10.4 ± 3.4); PbRh(−16.5 ± 3.3); PbPd{sub 3}(−29.6 ± 3.1); PbPt(−34.7 ± 3.3) kJ/mole of atoms. We will compare our results with previously published measurements. We will also compare the experimental measurements with enthalpies of formation of transition metal compounds with elements in the same vertical column in the periodic table. We will compare our measurements with predicted values on the basis of the semi empirical model of Miedema and coworkers and with ab initio values when available.

  3. A High-Throughput Biological Calorimetry Core: Steps to Startup, Run, and Maintain a Multiuser Facility.

    Science.gov (United States)

    Yennawar, Neela H; Fecko, Julia A; Showalter, Scott A; Bevilacqua, Philip C

    2016-01-01

    Many labs have conventional calorimeters where denaturation and binding experiments are setup and run one at a time. While these systems are highly informative to biopolymer folding and ligand interaction, they require considerable manual intervention for cleaning and setup. As such, the throughput for such setups is limited typically to a few runs a day. With a large number of experimental parameters to explore including different buffers, macromolecule concentrations, temperatures, ligands, mutants, controls, replicates, and instrument tests, the need for high-throughput automated calorimeters is on the rise. Lower sample volume requirements and reduced user intervention time compared to the manual instruments have improved turnover of calorimetry experiments in a high-throughput format where 25 or more runs can be conducted per day. The cost and efforts to maintain high-throughput equipment typically demands that these instruments be housed in a multiuser core facility. We describe here the steps taken to successfully start and run an automated biological calorimetry facility at Pennsylvania State University. Scientists from various departments at Penn State including Chemistry, Biochemistry and Molecular Biology, Bioengineering, Biology, Food Science, and Chemical Engineering are benefiting from this core facility. Samples studied include proteins, nucleic acids, sugars, lipids, synthetic polymers, small molecules, natural products, and virus capsids. This facility has led to higher throughput of data, which has been leveraged into grant support, attracting new faculty hire and has led to some exciting publications. PMID:26794364

  4. Resting energy expenditure and body composition in children with cancer: indirect calorimetry and bioimpedance analysis

    Directory of Open Access Journals (Sweden)

    M. V. Konovalova

    2014-07-01

    Full Text Available Resting energy expenditure (REE by indirect calorimetry and body composition by bioimpedance analysis are studied in three groups of children aged 5–18 years. Group 1 (n = 181 – patients in remission of cancer, group 2 (n = 55 – children with oncology diseases receiving chemotherapy or who are in the early period after hematopoietic stem cell transplantation, group 3 (n = 63 – children with non-malignant diseases of the gastrointestinal tract. To eliminate the influence of age and gender on the intergroup comparisons, body composition parameters were expressed as standardized values (z-scores relative to a reference group of healthy Russian children (n = 138,191. Group 1 was characterized by excess fat content with intact lean body mass, and groups 2 and 3 by protein depletion, more pronounced in Group 2 with a higher percentage of body fat. All used conventional formulas (WHO, Harris–Benedict and others in groups 1 and 3 underestimated REE as compared with indirect calorimetry. A new formula for REE, giving an unbiased estimate in the group 1 was proposed: REE (kcal/day = 28.7 × BCM (kg +10.5 × Height (cm – 38.6 × Age (years – 134, where BCM – body cell mass according to bioimpedance analysis (R2 = 0.67, the standard deviation of 196 kcal/day.

  5. Plasma power source based on a catalytic reaction of atomic hydrogen measured by water bath calorimetry

    International Nuclear Information System (INIS)

    Extreme ultraviolet (EUV) spectroscopy was recorded on microwave discharges of helium with 2% hydrogen. Novel emission lines were observed with energies of q x 13.6 eV, where q=1, 2, 3, 4, 6, 7, 8, 9, 11 or these discrete energies less 21.2 eV corresponding to inelastic scattering of these photons by helium atoms due to excitation of He (1s2) to He (1s12p1). The average hydrogen atom temperature was measured to be 180-210 eV versus ∼3 eV for pure hydrogen. The electron temperature Te for helium-hydrogen was 30,500±5% K compared to 7400±5% K for pure helium. Dominant He+ emission and an intensification of the plasma emission observed when He+ was present with atomic hydrogen demonstrated the role of He+ as a catalyst. Using water bath calorimetry, excess power was observed from the helium-hydrogen plasma compared to control krypton plasma. For example, for an input of 8.1 W, the total plasma power of the helium-hydrogen plasma measured by water bath calorimetry was 30.0 W corresponding to 21.9 W of excess power in 3 cm3. The excess power density and energy balance were high, 7.3 W/cm3 and -2.9x104 kJ/mole H2, respectively

  6. Titration calorimetry of surfactant–drug interactions: Micelle formation and saturation studies

    International Nuclear Information System (INIS)

    Highlights: ► Isothermal titration calorimetry can be used to monitor the saturation of micelles with pharmaceutical compounds. ► The number of drug molecules per micelle varies depending on the drug used and the temperature of the calorimeter. ► The change in enthalpy for the saturation of micelles with drugs can be endothermic or exothermic. ► The critical micellar concentration of an anionic surfactant (SDS) does not appear to vary in the presence of drugs. - Abstract: Isothermal titration calorimetry (ITC) was employed to monitor the addition of five model drugs to anionic surfactant based micelles, composed of sodium dodecyl sulfate (SDS), through to the point at which they were saturated with drug. Analysis of the resultant data using this newly developed method has confirmed the suitability of the technique to acquire such data with saturation limits established in all cases. Values for the point at which saturation occurred ranged from 17 molecules of theophylline per micelle at T = 298 K up to 63 molecules of caffeine per micelle at 310 K. Micellar systems can be disrupted by the presence of additional chemicals, such as the drugs used in this study, therefore a separate investigation was undertaken to determine the critical micellar concentration (CMC) for SDS in the presence of each drug at T = 298 K and 310 K using ITC. In the majority of cases, there was no appreciable alteration to the CMC of SDS with drug present.

  7. Cooling water calorimetry measuring results from the first years of ASDEX Upgrade operation

    International Nuclear Information System (INIS)

    At the tokamak ASDEX Upgrade an extensive cooling water calorimetry system was installed. This system has measured the toroidal and poloidal distributions of the energy deposition by monitoring the temperature rise of the cooling water in 80 separate cooling units in the divertor plates and the central heat shield. The measurements show, that there exist no toroidal asymmetries in the energy deposition on the divertor plates for all kinds of ohmic discharges and for ICRH discharges with a toroidal magnetic field directed opposite to the plasma current. However, Neutral Beam Injection causes a toroidal asymmetric energy deposition profile. Furthermore the reduction of the poloidal in-out asymmetry of the energy load at the divertor plates due to magnetic field reversion was detected. Making up the general energy balance of ASDEX Upgrade, adding the energy detected by the cooling water calorimetry system and the radiation loss energy measured by the bolometry diagnostic, one gets 92%-97% of the energy input. (orig./HD)

  8. Thermochemistry of some binary lead and transition metal compounds by high temperature direct synthesis calorimetry

    International Nuclear Information System (INIS)

    Highlights: • Studied binary lead-transition metal alloys by high temperature calorimetry. • Determined the enthalpies of formation of 8 alloys. • Compared the measurements with predictions by the model of Miedema and by the ab initio method. - Abstract: The standard enthalpies of formation of some binary lead and transition metal compounds have been measured by high temperature direct synthesis calorimetry. The reported results are: Pb3Sc5(−61.3 ± 2.9); PbTi4(−16.6 ± 2.4); Pb3Y5(−64.8 ± 3.6); Pb3Zr5(−50.6 ± 3.1); PbNb3(−10.4 ± 3.4); PbRh(−16.5 ± 3.3); PbPd3(−29.6 ± 3.1); PbPt(−34.7 ± 3.3) kJ/mole of atoms. We will compare our results with previously published measurements. We will also compare the experimental measurements with enthalpies of formation of transition metal compounds with elements in the same vertical column in the periodic table. We will compare our measurements with predicted values on the basis of the semi empirical model of Miedema and coworkers and with ab initio values when available

  9. Calorimetry, activity, and micro-FTIR analysis of CO chemisorption, titration, and oxidation on supported Pt

    Science.gov (United States)

    Sermon, Paul A.; Self, Valerie A.; Vong, Mariana S. W.; Wurie, Alpha T.

    1990-01-01

    The value of in situ analysis on CO chemisorption, titration and oxidation over supported Pt catalysts using calorimetry, catalytic and micro-FTIR methods is illustrated using silica- and titania-supported samples. Isothermal CO-O and O2-CO titrations have not been widely used on metal surfaces and may be complicated if some oxide supports are reduced by CO titrant. However, they can illuminate the kinetics of CO oxidation on metal/oxide catalysts since during such titrations all O and CO coverages are scanned as a function of time. There are clear advantages in following the rates of the catalyzed CO oxidation via calorimetry and gc-ms simultaneously. At lower temperatures the evidence they provide is complementary. CO oxidation and its catalysis of CO oxidation have been extensively studied with hysteresis and oscillations apparent, and the present results suggest the benefits of a combined approach. Silica support porosity may be important in defining activity-temperature hysteresis. FTIR microspectroscopy reveals the chemical heterogeneity of the catalytic surfaces used; it is interesting that the evidence with regard to the dominant CO surface species and their reactivities with regard to surface oxygen for present oxide-supported Pt are different from those seen on graphite-supported Pt.

  10. PREFACE: 16th International Conference on Calorimetry in High Energy Physics (CALOR 2014)

    Science.gov (United States)

    Novotny, Rainer W.

    2015-02-01

    The XVIth International Conference on Calorimetry in High Energy Physics - CALOR 2014 - was held in Giessen, Germany from 6-11 April 2014 at the Science Campus of the University. It was hosted by the Justus-Liebig-University and the HIC for FAIR Helmholtz International Center. The series of conferences on calorimetry were started in 1990 at Fermilab and are focusing primarily on operating and future calorimeter systems within the Hadron and High-Energy Physics community without neglecting the impact on other fields such as Astrophysics or Medical Imaging. Confirmed by the impressive list of over 70 oral presentations, 5 posters and over 100 attendees, the field of calorimetry appears alive and attractive. The present volume contains the written contributions of almost all presentations which can be found at http://calor2014.de. Time slots of 15 or 30 minutes including discussion were allocated. The conference was accompanied by a small exhibition of several industrial companies related to the field. The day before the opening of the scientific program, Richard Wigmans gave an excellent and vivid tutorial on basic aspects on calorimetry meant as an introduction for students and conference attendees new in the field. The opening ceremony was used to give an impression of the present and future status and the scientific program of the new FAIR facility nearby at Darmstadt presented by Klaus Peters from GSI. The conference program of the first day was dedicated to the performance and required future upgrade of the LHC experiments, dominated by ATLAS, CMS and LHCb. The program of the next day contained specific aspects on electronics and readout as well as calorimetry in outer space. Several contributions discussed in detail new concepts for hadron calorimeters within the CALICE collaboration completed by a session on sampling calorimeters. The next sections were dedicated to operating and future calorimeters at various laboratories and covering a wide range of

  11. Heat capacity and transition behavior of sucrose by standard, fast scanning and temperature-modulated calorimetry

    International Nuclear Information System (INIS)

    Highlights: • Experimental, apparent heat capacity of sucrose was investigated by advanced thermal analysis. • Vibrational heat capacity of solid state was linked with a low temperature experimental heat capacity of sucrose. • Equilibrium melting parameters of sucrose were determined. • Decomposition, superheating of crystalline sucrose during melting process were presented. • TGA, DSC, TMDSC, and FSC are useful tools for characterization of sucrose. - Abstract: The heat capacity (Cp) of crystalline and amorphous sucrose was determined using standard and quasi-isothermal temperature modulated differential scanning calorimetry. The results were combined with the published data determined by adiabatic calorimetry, and the Cp values are now reported for the wide 5–600 K range. The experimental Cp of solid sucrose at 5–300 K was used to calculate the vibrational, solid Cp based on the vibrational molecular motions. The calculated solid and liquid Cp together with the transition parameters for equilibrium conditions were used as references for detailed quantitative thermal analysis of crystalline and amorphous sucrose. Melting temperature (Tm) of the crystalline sucrose was identified in a broad 442–465 K range with a heat of fusion of 40–46 J/mol determined at heating rates 0.5–20 K/min, respectively. The equilibrium Tm and heat of fusion of crystalline sucrose were estimated at zero heating rate as Tom = 424.4 K and ΔHof = 32 kJ/mol, respectively. The glass transition temperature (Tg) of amorphous sucrose was at 331 K with a change in Cp of 267 J/(mol K) as it was estimated from reversing heat capacity by quasi-isothermal TMDSC on cooling. At heating rates less than 30 K/min, thermal decomposition occurred during melting, while at extreme rate of 1000 K/s, degradation was not observed. Data obtained by fast scanning calorimetry (FSC) at 1000 K/s, showed that Tm was 483 K and Tg was 364 K. Superheating effects were observed during the melting with

  12. Heat capacity and transition behavior of sucrose by standard, fast scanning and temperature-modulated calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Magoń, A. [Department of Chemistry, University of Technology, 35-959 Rzeszów (Poland); Wurm, A.; Schick, C. [Department of Physics, University of Rostock, 18057 Rostock (Germany); Pangloli, Ph.; Zivanovic, S. [Department of Food Science and Technology, University of Tennessee, Knoxville, TN 37996 (United States); Skotnicki, M. [Department of Pharmaceutical Technology, Poznan University of Medical Sciences, 60-780 Poznań (Poland); Pyda, M., E-mail: mpyda@utk.edu [Department of Chemistry, University of Technology, 35-959 Rzeszów (Poland)

    2014-08-10

    Highlights: • Experimental, apparent heat capacity of sucrose was investigated by advanced thermal analysis. • Vibrational heat capacity of solid state was linked with a low temperature experimental heat capacity of sucrose. • Equilibrium melting parameters of sucrose were determined. • Decomposition, superheating of crystalline sucrose during melting process were presented. • TGA, DSC, TMDSC, and FSC are useful tools for characterization of sucrose. - Abstract: The heat capacity (C{sub p}) of crystalline and amorphous sucrose was determined using standard and quasi-isothermal temperature modulated differential scanning calorimetry. The results were combined with the published data determined by adiabatic calorimetry, and the C{sub p} values are now reported for the wide 5–600 K range. The experimental C{sub p} of solid sucrose at 5–300 K was used to calculate the vibrational, solid C{sub p} based on the vibrational molecular motions. The calculated solid and liquid C{sub p} together with the transition parameters for equilibrium conditions were used as references for detailed quantitative thermal analysis of crystalline and amorphous sucrose. Melting temperature (T{sub m}) of the crystalline sucrose was identified in a broad 442–465 K range with a heat of fusion of 40–46 J/mol determined at heating rates 0.5–20 K/min, respectively. The equilibrium T{sub m} and heat of fusion of crystalline sucrose were estimated at zero heating rate as T{sup o}{sub m} = 424.4 K and ΔH{sup o}{sub f} = 32 kJ/mol, respectively. The glass transition temperature (T{sub g}) of amorphous sucrose was at 331 K with a change in C{sub p} of 267 J/(mol K) as it was estimated from reversing heat capacity by quasi-isothermal TMDSC on cooling. At heating rates less than 30 K/min, thermal decomposition occurred during melting, while at extreme rate of 1000 K/s, degradation was not observed. Data obtained by fast scanning calorimetry (FSC) at 1000 K/s, showed that T{sub m} was

  13. Feasibility study on using fast calorimetry technique to measure a mass attribute as part of a treaty verification regime

    International Nuclear Information System (INIS)

    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 ∼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

  14. Feasibility study on using fast calorimetry technique to measure a mass attribute as part of a treaty verification regime

    Energy Technology Data Exchange (ETDEWEB)

    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

    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

  15. Online particle detection with Neural Networks based on topological calorimetry information

    International Nuclear Information System (INIS)

    This paper presents the latest results from the Ringer algorithm, which is based on artificial neural networks for the electron identification at the online filtering system of the ATLAS particle detector, in the context of the LHC experiment at CERN. The algorithm performs topological feature extraction using the ATLAS calorimetry information (energy measurements). The extracted information is presented to a neural network classifier. Studies showed that the Ringer algorithm achieves high detection efficiency, while keeping the false alarm rate low. Optimizations, guided by detailed analysis, reduced the algorithm execution time by 59%. Also, the total memory necessary to store the Ringer algorithm information represents less than 6.2 percent of the total filtering system amount.

  16. Applications of Isothermal Titration Calorimetry in Biophysical Studies of G-quadruplexes

    Directory of Open Access Journals (Sweden)

    Concetta Giancola

    2009-07-01

    Full Text Available G-quadruplexes are higher-order nucleic acids structures formed by G-rich sequences that are stabilized by tetrads of hydrogen-bonded guanine bases. Recently, there has been growing interest in the study of G-quadruplexes because of their possible involvement in many biological processes. Isothermal titration calorimetry (ITC has been proven to be a useful tool to study the energetic aspects of G-quadruplex interactions. Particularly, ITC has been applied many times to determine the thermodynamic properties of drug-quadruplex interactions to screening among various drugs and to address drug design. In the present review, we will focus on the ITC studies of G-quadruplex structures and their interaction with proteins and drugs and the most significant results will be discussed.

  17. DETERMINATION OF HYDROGEN DESORBED THROUGH THERMAL CALORIMETRY IN A HIGH STRENGTH STEEL

    Directory of Open Access Journals (Sweden)

    Carolina A. Asmus

    2014-03-01

    Full Text Available The following study aims to quantify the release activation energy (Ea of hydrogen (H from lattice sites, reversible or irreversible, where the H can be trapped. Moreover, enthalpy changes associated with the main hydrogen (H trapping sites can be analyzed by means of differential scanning calorimetry (DSC. In this technique, the peak temperature measurement is determined at two different heating rates, 3ºC/min y 5ºC/min, from ambient temperature to 500°C. In order to simulate severe conditions of hydrogen income into resulfurized high strength steel, electrolytic permeation tests were performed on test tubes suitable for fatigue tests. Sometimes during charging, H promoters were aggregated to electrolytic solution. Subsequently, the test tubes were subjected to flow cycle fatigue tests. Finally, irreversible trap which anchor more strongly H atoms are MnS inclusions. Its role on hydrogen embrittlement during fatigue tests is conclusive.

  18. Temperature Measurement and Water Flow Calorimetry for the Neutral Beam Test Stand Operation at KAERI

    International Nuclear Information System (INIS)

    Temperature measurements during the beam line operation of the neutral beam test stand(NB-TS) is very important for the estimation of the absorbed energy by the beam line components such calorimeter and also for the temperature monitoring of the various components, and have been accomplished by the utilization of many of the thermocouples(TCs) installed onto the NB-TS and the data acquisition system(DAQ) based on the National Instruments' (NI) SCXI system. Preliminary estimations of the absorbed energy by the calorimeter during the beam extraction have been made. Greater efforts for the noise reduction in the TC signal acquisition has been made with partial success. We present the status of the temperature measurement and water flow calorimetry(WFC) related to the NB-TS operations

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

    Science.gov (United States)

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

    2010-01-01

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

  20. Substrate binding properties of potato tuber ADP-glucose pyrophosphorylase as determined by isothermal titration calorimetry.

    Science.gov (United States)

    Cakir, Bilal; Tuncel, Aytug; Green, Abigail R; Koper, Kaan; Hwang, Seon-Kap; Okita, Thomas W; Kang, ChulHee

    2015-06-01

    Substrate binding properties of the large (LS) and small (SS) subunits of potato tuber ADP-glucose pyrophosphorylase were investigated by using isothermal titration calorimetry. Our results clearly show that the wild type heterotetramer (S(WT)L(WT)) possesses two distinct types of ATP binding sites, whereas the homotetrameric LS and SS variant forms only exhibited properties of one of the two binding sites. The wild type enzyme also exhibited significantly increased affinity to this substrate compared to the homotetrameric enzyme forms. No stable binding was evident for the second substrate, glucose-1-phosphate, in the presence or absence of ATPγS suggesting that interaction of glucose-1-phosphate is dependent on hydrolysis of ATP and supports the Theorell-Chance bi bi reaction mechanism. PMID:25953126

  1. Analysis of the microbial growth in {sup 60}Co {gamma}-irradiated foods by calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Masakazu; Hayashi, Toshio [Osaka Pref. Univ., Research Institute for Advanced Science Technology, Sakai, Osaka (Japan); Hamasaki, Koji; Wirkner, Sandra; Constantinoiu, Elena; Takahashi, Katsutada [Osaka Pref. Univ., College of Agriculture, Sakai, Osaka (Japan)

    2002-09-01

    Using a heat conduction calorimeter equipped with 24 sample units the heat evolutions from growing {sup 60}Co {gamma}-irradiated bioburden of black pepper seeds and frozen beef were detected in the form of growth thermograms. {sup 60}Co {gamma}-irradiation affected the growth pattern in which a dose-dependent reduction of the growth rate constant was observed together with the retardation in growth, indicating a combination of bactericidal and bacteriostatic effects. We successfully determined the minimal inactivation doses for the two food samples using the relationship between the irradiation dose and the retardation in growth t{sub {alpha}}, or the growth rate constant {mu} obtained from the growth thermograms. These results strongly suggested the possibility of calorimetry as measure of predictive microbiology in food irradiation. (author)

  2. Solubility increase of colloidal zinc hydroxide as revealed by isothermal titration calorimetry

    International Nuclear Information System (INIS)

    Highlights: • Association between zinc (II) and dipicolylamine was studied by ITC. • Increasing heat release was observed as the titration proceeded. • Thermodynamics of the association was discussed. • The increasing heat release was ascribed to solubility increase of colloidal Zn(OH)2. - Abstract: In this study, association between zinc (II) and dipicolylamine was studied by isothermal titration calorimetry. At neutral of weakly alkaline conditions, with zinc (II) in cell and dipicolylamine in syringe, increasing heat release was observed as the titration proceeded. Considering the equilibrium between Zn2+ and Zn(OH)2 at these conditions, the increasing heat release is ascribed to the increasing solubilization of colloidal Zn(OH)2 followed by neutralization of OH- by the buffer. Though quantitative determination of the increase in solubility is not accomplished, to the best of our knowledge, this is the first report about solubility increase of colloidal zinc hydroxide using calorimetric method

  3. A digital Front-End and Readout MIcrosystem for calorimetry at LHC

    CERN Multimedia

    2002-01-01

    % RD-16 A Digital Front-End and Readout Microsystem for Calorimetry at LHC \\\\ \\\\Front-end signal processing for calorimetric detectors is essential in order to achieve adequate selectivity in the trigger function of an LHC experiment, with data identification and compaction before readout being required in the harsh, high rate environment of a high luminosity hadron machine. Other crucial considerations are the extremely wide dynamic range and bandwidth requirements, as well as the volume of data to be transferred to following stages of the trigger and readout system. These requirements are best met by an early digitalization of the detector information, followed by integrated digital signal processing and buffering functions covering the trigger latencies.\\\\ \\\\The FERMI (Front-End Readout MIcrosystem) is a digital implementation of the front-end and readout electronic chain for calorimeters. It is based on dynamic range compression, high speed A to D converters, a fully programmable pipeline/digital filter c...

  4. Integration and global analysis of isothermal titration calorimetry data for studying macromolecular interactions.

    Science.gov (United States)

    Brautigam, Chad A; Zhao, Huaying; Vargas, Carolyn; Keller, Sandro; Schuck, Peter

    2016-05-01

    Isothermal titration calorimetry (ITC) is a powerful and widely used method to measure the energetics of macromolecular interactions by recording a thermogram of differential heating power during a titration. However, traditional ITC analysis is limited by stochastic thermogram noise and by the limited information content of a single titration experiment. Here we present a protocol for bias-free thermogram integration based on automated shape analysis of the injection peaks, followed by combination of isotherms from different calorimetric titration experiments into a global analysis, statistical analysis of binding parameters and graphical presentation of the results. This is performed using the integrated public-domain software packages NITPIC, SEDPHAT and GUSSI. The recently developed low-noise thermogram integration approach and global analysis allow for more precise parameter estimates and more reliable quantification of multisite and multicomponent cooperative and competitive interactions. Titration experiments typically take 1-2.5 h each, and global analysis usually takes 10-20 min. PMID:27055097

  5. CZECHOSLOVAK FOOTPRINTS IN THE DEVELOPMENT OF METHODS OF THERMOMETRY, CALORIMETRY AND THERMAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Pavel Holba

    2012-07-01

    Full Text Available A short history on the development of thermometric methods are reviewed accentuating the role of Rudolf Bárta in underpinning special thermoanalytical conferences and new journal Silikáty in fifties as well as Vladimir Šatava mentioning his duty in the creation of the Czech school on thermoanalytical kinetics. This review surveys the innovative papers dealing with thermal analysis and the related fields (e.g. calorimetry, kinetics which have been published by noteworthy postwar Czechoslovak scholars and scientists and by their disciples in 1950-1980. Itemized 227 references with titles show rich scientific productivity revealing that many of them were ahead of time even at international connotation.

  6. Considerations on the design of front-end electronics for silicon calorimetry for the SSC

    International Nuclear Information System (INIS)

    Some considerations are described for the design of a silicon-based sampling calorimetry detector for the Superconducting Super Collider (SSC). The use of silicon as the detection medium allows fast, accurate, and fine-grained energy measurements - but for optimal performance, the front-end electronics must be matched to the detector characteristics and have the speed required by the high SSC interaction rates. The relation between the signal-to-noise rtio of the calorimeter electronics and the charge collection time, the preamplifier power dissipation, detector capacitance and leakage, charge gain, and signal shaping and sampling was studied. The electrostatic transformer connection was analyzed and found to be unusable for a tightly arranged calorimeter because of stray capacitance effects. The method of deconvolutional sampling was developed as a means for pileup correction following synchronous sampling and analog storage

  7. Online Particle Detection by Neural Networks Based on Topologic Calorimetry Information

    CERN Document Server

    Ciodaro, T; The ATLAS collaboration; de Seixas, JM; Damazio, D

    2011-01-01

    The neural ringer is an alternative algorithm (for both feature extraction and hypothesis testing) for electron identification at the ATLAS L2 calorimetry trigger. The feature extraction consists on calculating concentric energetic rings at each calorimeter layer. For each layer, the first ring is the energy from the hottest cell, and the energy of the outer cells are summed up forming the second ring (and sequentially for the other rings). A feedforward MLP neural network operates over the extracted rings performing particle identification. This study shows the later resuls considering improvements on the HLT implementation and performance evaluation over pileup from Monte Carlo proton-proton collisions simulations of 14 TeV at 2e34 luminosity.

  8. FLUKA studies of hadron-irradiated scintillating crystals for calorimetry at the High-Luminosity LHC

    CERN Document Server

    Quittnat, Milena Eleonore

    2015-01-01

    Calorimetry at the High-Luminosity LHC (HL-LHC) will be performed in a harsh radiation environment with high hadron fluences. The upgraded CMS electromagnetic calorimeter design and suitable scintillating materials are a focus of current research. In this paper, first results using the Monte Carlo simulation program FLUKA are compared to measurements performed with proton-irradiated LYSO, YSO and cerium fluoride crystals. Based on these results, an extrapolation to the behavior of an electromagnetic sampling calorimeter, using one of the inorganic scintillators above as an active medium, is performed for the upgraded CMS experiment at the HL-LHC. Characteristic parameters such as the induced ambient dose, fluence spectra for different particle types and the residual nuclei are studied, and the suitability of these materials for a future calorimeter is surveyed. Particular attention is given to the creation of isotopes in an LYSO-tungsten calorimeter that might contribute a prohibitive background to the measu...

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

    Science.gov (United States)

    Folmer, J. C. W.; Franzen, Stefan

    2003-07-01

    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 and application of MDSC to problems of current interest is outlined with special emphasis on the contrast between crystallization and vitrification. Glass formation deserves greater emphasis in the undergraduate curriculum. Glass transitions are increasingly recognized as an important aspect of materials properties and dynamics in fields ranging from polymer science to protein folding. The example chosen for study is a comparison of polyethylene glycol and atactic polypropylene glycol. The experiment is easily performed in a typical three-hour lab session.

  10. Partitioning of late gestation energy expenditure in ewes using indirect calorimetry and a linear regression approach

    DEFF Research Database (Denmark)

    Kiani, Alishir; Chwalibog, André; Nielsen, Mette O;

    2007-01-01

    study metabolizable energy (ME) intake ranges for twin-bearing ewes were 220-440, 350- 700, 350-900 kJ per metabolic body weight (W0.75) at week seven, five, two pre-partum respectively. Indirect calorimetry and a linear regression approach were used to quantify EE(gest) and then partition to EE......(conceptus) and EE(homeorhetic). Energy expenditure of basal metabolism of the non-gravid tissues (EE(bmng)), derived from the intercept of the linear regression equation of retained energy [kJ/W0.75] and ME intake [kJ/W(0.75)], was 298 [kJ/ W0.75]. Values of the intercepts of the regression equations at week...

  11. DNA heats up : Energetics of genome ejection from phage revealed by isothermal titration calorimetry

    CERN Document Server

    Jeembaeva, Meerim; Castelnovo, Martin; Evilevitch, Alex

    2010-01-01

    Most bacteriophages are known to inject their double-stranded DNA into bacteria upon receptor binding in an essentially spontaneous way. This downhill thermodynamic process from the intact virion toward the empty viral capsid plus released DNA is made possible by the energy stored during active packaging of the genome into the capsid. Only indirect measurements of this energy have been available until now using either single-molecule or osmotic suppression techniques. In this paper, we describe for the first time the use of isothermal titration calorimetry to directly measure the heat released (or equivalently the enthalpy) during DNA ejection from phage lambda, triggered in solution by a solubilized receptor. Quantitative analyses of the results lead to the identification of thermodynamic determinants associated with DNA ejection. The values obtained were found to be consistent with those previously predicted by analytical models and numerical simulations. Moreover, the results confirm the role of DNA hydrat...

  12. Differential scanning calorimetry predicts the critical quality attributes of amorphous glibenclamide

    DEFF Research Database (Denmark)

    Mah, Pei T; Laaksonen, Timo; Rades, Thomas;

    2015-01-01

    Selection of a crystallinity detection tool that is able to predict the critical quality attributes of amorphous formulations is imperative for the development of process control strategies. The main aim of this study was to determine the crystallinity detection tool that best predicts the critical...... quality attributes (i.e. physical stability and dissolution behaviour) of amorphous material. Glibenclamide (model drug) was milled for various durations using a planetary mill and characterised using Raman spectroscopy and differential scanning calorimetry (DSC). Physical stability studies upon storage...... the superiority of DSC (onset of crystallisation) in detecting residual crystallinity in the samples milled for between 60 and 120min, which were not detectable with Raman spectroscopy. The physical stability upon storage and dissolution behaviour of the milled samples improved with increased milling...

  13. From calorimetry to medical imaging: a shining example of successful transfer!

    CERN Multimedia

    Caroline Duc

    2012-01-01

    A team at CERN has drawn inspiration from calorimetry methods developed for high-energy physics to create a new positron-emission tomography system for use in medical imaging, which they’ve dubbed AX-PET. With support from European and American laboratories*, the project is reaching fruition, as initial tests confirm its promise.   Snapshot of a “phantom”, a test object, surrounded by the AX-PET photon detectors. Positron-emission tomography (PET) is a medical imaging technique based on the matter-antimatter interaction that can provide a three-dimensional representation of the metabolic activity of an organ. To do so, radioactive marker molecules are first injected into the subject. As the marker decays, it emits positrons (antimatter particles), which are annihilated upon encountering electrons in the surrounding environment. The resulting flash, consisting of two photons, is detected by the PET machine. In conventional PET systems, it is impossible to improv...

  14. Electromagnetic calorimetry with $PbWO^{4}$ in the energy regime below 1 GeV

    CERN Document Server

    Novotny, R; Döring, W; Hejny, V; Hofstäetter, A; Korzhik, M V; Metag, V; Ströher, H

    2000-01-01

    The study of the performance and application of PbWO/sub 4/ in electromagnetic calorimetry at energies far below 1 GeV has been continued. The significantly improved optical and scintillation properties of 15 cm long Nb/La-doped crystals, optimized for the ECAL /CMS calorimeter, are documented. The lineshape, energy and time response of a 5*5 matrix are tested with monoenergetic photons up to 790 MeV energy and compared to previous measurements. First attempts have been made to enhance the scintillation yield by suitable dopants (Mo, Tb) for applications at very low photon energies. As a first large scale project at medium energies, the proposed concept for a compact photon spectrometer to be implemented into the ANKE magnetic spectrometer at COSY (KFA Julich) is illustrated. (4 refs).

  15. Design and First Measurements of an Alternative Calorimetry Chamber for the HZB Quadrupole Resonator

    CERN Document Server

    Keckert, Sebastian; Knobloch, Jens; Kugeler, Oliver

    2015-01-01

    The systematic research on superconducting thin films requires dedicated testing equipment. The Quadrupole Resonator (QPR) is a specialized tool to characterize the superconducting RF properties of circular planar samples. A calorimetric measurement of the RF surface losses allows the surface resistance to be measured with sub nano-ohm resolution. This measurement can be performed over a wide temperature and magnetic field range, at frequencies of 433, 866 and 1300 MHz. The system at Helmholtz-Zentrum Berlin (HZB) is based on a resonator built at CERN and has been optimized to lower peak electric fields and an improved resolution. In this paper the design of an alternative calorimetry chamber is presented, providing flat samples for coating which are easy changeable. All parts are connected by screwing connections and no electron beam welding is required. Furthermore this design enables exchangeability of samples between the resonators at HZB and CERN. First measurements with the new design show ambiguous r...

  16. Enthalpies of formation of Mo-Pt alloys by high temperature direct reaction synthesis calorimetry

    International Nuclear Information System (INIS)

    In the present work, the enthalpies of formation of Mo-Pt alloys are determined by high temperature direct reaction synthesis calorimetry at 1768 K (Mo6Pt, ε', MoPt2, and (Pt) solid solution) and 1526 K (MoPt). The following values are reported: ΔfH1768K(Mo6Pt)=-13.0±1.9kJ/mol.at.; ΔfH0(ε')=-26.1±4.9kJ/mol.at.; ΔfH0(MoPt)=-27.7±3.9kJ/mol.at.; ΔfH0(MoPt2)=-36.9±1.8kJ/mol.at.; ΔfH0(Pt)=-27.1±4.2kJ/mol.at. The results are compared with predicted ab initio data

  17. Study and characterization of ammonium diuranate and uranium trioxide by thermogravimetry and differential scanning calorimetry

    International Nuclear Information System (INIS)

    Thermogravimetry (TG), Differential Thermogravimetry (DTG) and Differential Scanning Calorimetry (DSC) were used to characterize the thermal behavior of ammonium diuranate (ADU) and uranium trioxide (UO3) produced at IPEN'S Chemical Enginnering Department. Compounds characterization was done using the molar ratios among the compounds and the oxides resulting from thermal decomposition. The TG and DTG curves registered for each sample were used for the determination of the following temperatures: - temperature of water evolution (free and crystallized water); - ammonia evolution and oxidation temperature; - ocluded ammonium nitrate decomposition temperature and - oxygen release temperature. The intermediate phases and their thermal stabilities were also identified by TG and DTG and confirmed by DSC curves, DSC curves showed also the exothermic and endothermic behavior of the processes involved. Finally, the great amount of data collected in this study can be handed as a guide by the professionals responsible for the operation of ADU,UO3 and UF4 pilot plants. (Author)

  18. Direct Coupling of SiPMs to Scintillator Tiles for Imaging Calorimetry and Triggering

    CERN Document Server

    Simon, Frank; Joram, Christian

    2010-01-01

    The recent availability of blue sensitive silicon photomultipliers allows the direct readout of blue emitting plastic scintillator tiles without the use of a wavelength shifting fiber. Such directly read out tiles, without light guides, are attractive for the use in highly granular calorimeters that use large numbers of individual cells and in other applications where very compact designs are needed. However, the total signal amplitude and the uniformity of the response can be problematic in such cases. We have developed a scanning setup to investigate the response of scintillator tiles with SiPM readout in detail. It was used to develop optimized scintillator tile geometries for highly granular hadronic calorimetry at future colliders and to investigate the feasibility of a SiPM readout for the trigger of the ATLAS ALFA luminosity detectors. We report on results obtained with specialized scintillator tile geometries, discuss first results obtained with directly coupled SiPM readout of the ATLAS ALFA trigger ...

  19. Dual-Readout Calorimetry for High-Quality Energy Measurements. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wigmans, Richard; Nural, Akchurin

    2013-09-01

    This document constitutes the final report on the project Dual-Readout Calorimetry for High-Quality Energy Measurements. The project was carried out by a consortium of US and Italian physicists, led by Dr. Richard Wigmans (Texas tech University). This consortium built several particle detectors and tested these at the European Center for Nuclear Research (CERN) in Geneva, Switzerland. The idea arose to use scintillating crystals as dual-readout calorimeters. Such crystals were of course already known to provide excellent energy resolution for the detection of particles developing electromagnetic (em) showers. The efforts to separate the signals from scintillating crystals into scintillation and Cerenkov components led to four different methods by which this could be accomplished. These methods are based on a) the directionality, b) spectral differences, c) the time structure, and d) the polarization of the signals.

  20. Application of fluorine calorimetry method for determination of compound formation enthalpy

    International Nuclear Information System (INIS)

    Systematized and analyzed in detail are literary data on enthalpies of fluoride formation as well as other multiple compounds of Zr, Hf, U, Nb, Ta, Ru, Cd, Yt, Th, Be, Mo, W, V and other elements prepared by the fluorine calorimetry method. Considered and discussed are the results of determinations of combustion heats of different metals in fluorine, the most significant non-metals as well as compounds like oxides, sulfides, nitrides, phosphides, carbides, borides, low fluorides and others. Discussed is the influence of different factors on the accuracy of the data obtained. Separately considered are the results of determination of heat effects of reactions of fluoration with participation of a number of other fluorine-containing oxidants ( oxygen difluoride, chlorine, xenon, nitrogen, carbon, boron, silicon and sulfur fluorides)

  1. Evaluation of errors in determination of DNA melting curve registered with differential scanning calorimetry

    International Nuclear Information System (INIS)

    The differential scanning calorimetry (DSC) is more sensitive than UV absorption spectrophotometry as a tool for the measurement of DNA melting curves. The advantage of DSC is a direct determination of differential melting curves (DMC) obtained without numerical differentiation. However, the difference between the helix-coil transition enthalpies of AT and GC base pairs can cause distortions in the shape of melting curve. Up to date, the errors caused by those distortions were not evaluated. In this study, a simple procedure of recalculation of a calorimetric DMC into a real DMC is developed. It demonstrates that the 'real' melting curve and differential melting curve deviate very slightly from the same two curves calculated from DSC data. The melting temperature and the temperature melting range are usually the same even if the difference in the enthalpies is several times higher than a real one

  2. FLUKA studies of hadron-irradiated scintillating crystals for calorimetry at the High-Luminosity LHC

    International Nuclear Information System (INIS)

    Calorimetry at the High-Luminosity LHC (HL-LHC) will be performed in a harsh radiation environment with high hadron fluences. The upgraded CMS electromagnetic calorimeter design and suitable scintillating materials are a focus of current research. In this paper, first results using the Monte Carlo simulation program FLUKA are compared to measurements performed with proton-irradiated LYSO, YSO and cerium fluoride crystals. Based on these results, an extrapolation to the behavior of an electromagnetic sampling calorimeter, using one of the inorganic scintillators above as an active medium, is performed for the upgraded CMS experiment at the HL-LHC. Characteristic parameters such as the induced ambient dose, fluence spectra for different particle types and the residual nuclei are studied, and the suitability of these materials for a future calorimeter is surveyed. Particular attention is given to the creation of isotopes in an LYSO-tungsten calorimeter that might contribute a prohibitive background to the measured signal

  3. Research and Development for the ATLAS Forward Calorimetry at the HL-LHC

    CERN Document Server

    Cheplakov, Alexander

    2015-01-01

    A total luminosity of 3000/fb is expected at the HL-LHC, which corresponds to total irradiation doses which are more than doubled compared to the original design, taking into account a safety factor of 2 representing our confidence in radiation background simulations. Moreover, the increased instantaneous luminosity will result in a much higher detector occupancy. The ATLAS Forward Calorimeters (FCal) will be affected by these factors. A rich R&D program is ongoing to evaluate the consequences of the LHC modernization and to investigate di_erent scenarios proposed for the Phase-II detector upgrade. This contribution will concentrate on simulation studies of the FCal degradation and on irradiation tests performed at the IBR-2m reactor in Dubna. Results from radiation-tolerant sensors and components of the future read-out and voltage distribution system for various upgrade options of the forward calorimetry will be presented.

  4. Energetics of methanol and formic acid oxidation on Pt(111): Mechanistic insights from adsorption calorimetry

    Science.gov (United States)

    Silbaugh, Trent L.; Karp, Eric M.; Campbell, Charles T.

    2016-08-01

    The catalytic and electrocatalytic oxidation and reforming of methanol and formic acid have received intense interest due to potential use in direct fuel cells and as prototype models for understanding electrocatalysis. Consequently, the reaction energy diagram (energies of all the adsorbed intermediates and activation energies of all the elementary steps) have been estimated for these reactions on Pt(111) by density functional theory (DFT) in several studies. However, no experimental measurement of these energy diagrams have been reported, nor is there a consensus on the mechanisms. Here, we use energies of key intermediates on Pt(111) from single crystal adsorption calorimetry (SCAC) and temperature programmed desorption (TPD) to build a combined energy diagram for these reactions. It suggests a new pathway involving monodentate formate as a key intermediate, with bidentate formate only being a spectator species that slows the rate. This helps reconcile conflicting proposed mechanisms.

  5. Use of isothermal titration calorimetry to study the interaction of short-chain alcohols with lipid membranes

    DEFF Research Database (Denmark)

    Trandum, Christa; Westh-Andersen, Peter; Jørgensen, Kent;

    1999-01-01

    short-chain alcohols on Lipid bilayers. isothermal titration calorimetry (ITC) has been used to determine the energy involved in the association of the alcohols with lipid bilayers. Pure unilamellar DMPC liposomes and DMPC liposomes incorporated with different amounts of cholesterol, sphingomyelin and...... dependent on the lipid bilayer composition. In the presence of high concentrations of cholesterol, the binding enthalpy of ethanol is decreased, whereas the presence of ceramides enhances the enthalpic response of the lipid bilayer to ethanol. Isothermal titration calorimetry offers a new methodology of...

  6. Comparison of Indirect Calorimetry and Predictive Equations in Estimating Resting Metabolic Rate in Underweight Females

    Directory of Open Access Journals (Sweden)

    Soghra ALIASGHARZADEH

    2015-10-01

    Full Text Available Background: Underweight as a public health problem in young women is associated with nutritional deficiencies, menstrual irregularity, eating disorders, reduced fertility, etc. Since resting metabolic rate (RMR is a necessary compo-nent in the development of nutrition support therapy, therefore we determined the accuracy of commonly used pre-dictive equations against RMR measured by indirect calorimetry among healthy young underweight females.Methods: This cross-sectional study was conducted on 104 underweight females aged 18-30 years old with body mass index (BMI <18.5 kg/m2 in 2013 . After collecting anthropometric data, body composition was measured by bioelec-tric impedance analysis (BIA. RMR was measured by using indirect calorimetry (FitMate™ and was estimated by 10 commonly used predictive equations. Comparisons were conducted using paired t-test. The accuracy of the RMR equations was evaluated on the basis of the percentage of subjects’ predicted RMR within 10% of measured RMR.Results: The mean BMI of subjects was 17.3±1.3 kg/m2. The measured RMR ranged 736-1490 kcal/day (mean 1084.7±175 kcal/day. Findings indicated that except Muller and Abbreviation, other equations significantly over es-timated RMR, compared to measured value (P<0.05. As an individual prediction accuracy, these predictive equations showed poor performance with the highest accuracy rate of 54.8% for Muller equation (22.1% under and 23.1% over-prediction and 43.3% for Abbreviation equation (31.7% under and 25% over-prediction, the percentage bias was 1.8% and 0.63% and RMSE was 162 and 173 kcal/d, respectively.Conclusion: Although Muller equation gave fairly acceptable prediction, more suitable new equations are needed to be developed to help better management of nutritional plans in young underweight people.

  7. Determination of the half-life and specific thermal power of 241Pu by nuclear calorimetry

    International Nuclear Information System (INIS)

    241Pu has the shortest half-life of the abundant plutonium isotopes present in reprocessed irradiated nuclear fuel with a value of approximately 14.3 years. It is important to know the half-life of 241Pu with a higher fractional accuracy than that of the other plutonium isotopes because the half-life of 241Pu and its associated uncertainty affects the estimation by decay calculation of both the total amount of separated plutonium in storage and the determination of the total plutonium mass by non-destructive assay. This paper addresses the determination of the 241Pu half-life using nuclear calorimetry by the measurement of the thermal power as 241Pu evolves in time from a sealed plutonium source, ideally initially rich in 241Pu and chemically stripped of 241Am. The absolute accuracy of nuclear calorimeters can be ensured over long periods of time (many years) using long-lived nuclear reference materials and/or traceable electrical heat standards. One can, therefore, expect nuclear calorimetry to offer an accurate way to determine the half-life of 241Pu, which is comparable in quality and independent, yet complementary, to other approaches. Temporal analysis of the power-versus-time data also yields an estimate of the specific power of 241Pu, which other methods do not. After describing the principle of the method and developing the pertinent mathematical expressions, we outline the approach by drawing on some unpublished notes of Kenneth C. Jordan who carried out such experiments at the Mound Laboratory over 40 years ago. Today, Jordan’s work remains possibly the most significant experiment of its type to the 241Pu nuclear data evaluator. However, objectively assigning confidence to his results is problematic because the details of the experiments and data reduction have never been adequately reported. This work goes some way to that end but, without the raw data and first-hand knowledge, cannot provide a complete record. We conclude that a new high

  8. Kinetic properties of two Rhizopus exo-polygalacturonase enzymes hydrolyzing galacturonic acid oligomers using isothermal titration calorimetry

    Science.gov (United States)

    The kinetic characteristics of two Rhizopus oryzae exo-polygalacturonases acting on galacturonic acid oligomers (GalpA) were determined using isothermal titration calorimetry (ITC). RPG15 hydrolyzing (GalpA)2 demonstrated a Km of 55 uM and kcat of 10.3 s^-1^ while RPG16 was shown to have greater af...

  9. Stiffness transitions in SixSe1-x glasses from Raman scattering and temperature-modulated differential scanning calorimetry

    Science.gov (United States)

    Selvanathan, D.; Bresser, W. J.; Boolchand, P.

    2000-06-01

    Temperature-modulated differential scanning calorimetry (MDSC) measurements on SixSe1-x glasses show glass transitions to be thermally reversing in character in the composition window 0.200.27, the CS mode in addition to the ES and CM also splits into a doublet indicating growth of substantial medium range structure. The large compositional width (0.20MDSC.

  10. Isothermal titration calorimetry and surface plasmon resonance allow quantifying substrate binding to different binding sites of Bacillus subtilis xylanase

    DEFF Research Database (Denmark)

    Cuyvers, Sven; Dornez, Emmie; Abou Hachem, Maher;

    2012-01-01

    Isothermal titration calorimetry and surface plasmon resonance were tested for their ability to study substrate binding to the active site (AS) and to the secondary binding site (SBS) of Bacillus subtilis xylanase A separately. To this end, three enzyme variants were compared. The first was a...

  11. Thermodynamic characteristics of the acid-base equilibria of taurine in aqueous solutions, according to calorimetry data

    Science.gov (United States)

    Gridchin, S. N.; Shekhanov, R. F.; Pyreu, D. F.

    2015-02-01

    Enthalpies of the neutralization and protonation of taurine (HL) are measured by direct calorimetry at 298.15 K and ionic strengths of 0.3, 0.5, and 1.0 (KNO3). The standard thermodynamic characteristics of HL protolytic equilibria are calculated.

  12. Determination of thermodynamic potentials and the aggregation number for micelles with the mass-action model by isothermal titration calorimetry

    DEFF Research Database (Denmark)

    Olesen, Niels Erik; Westh, Peter; Holm, René

    2015-01-01

    The aggregation number (n), thermodynamic potentials (ΔG, ΔH, ΔS) and critical micelle concentration (CMC) for 6 natural bile salts were determined on the basis of both original and previously published isothermal titration calorimetry (ITC) data. Different procedures to estimate parameters of...

  13. Use of scanning calorimetry and microrespiration to determine effects of Bt toxin doses on Pandemis leafroller (Lepidoptera: Tortricidae) metabolosim

    Science.gov (United States)

    Differential scanning calorimetry and microrespiration were used to determine the effects of the biopesticide, Bt toxin, on the metabolism of infected Pandemis leafroller, Pandemis purusana (Kearfott). The metabolic heat rate, CO2 evolution, O2 consumption of 2nd and 3rd instars following a 2 h expo...

  14. The use of immersion calorimetry in the determination of micropore distribution of carbons in the course of activation

    OpenAIRE

    Kraehenbuehl, F.; Stoeckli, Fritz; Addoun, A.; Ehrburger, P.; Donnet, J. B.

    2007-01-01

    The combination of gas-solid adsorption experiments with immersion calorimetry of carbons into liquids of increasing molecular dimensions leads to accurate micropore distributions in the range 0.4-0.8 nm. This technique is used to study the development of the micropore structure during activation of carbons with CO2 or KOH.

  15. Validation and recovery rates of an indirect calorimetry headbox system used to measure heat production of cattle

    Science.gov (United States)

    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...

  16. Evaluation of three flame retardant (FR) grey cotton blend nonwoven fabrics using micro-scale combustion calorimetry

    Science.gov (United States)

    Unbleached (grey or greige) cotton nonwoven (NW) fabrics (with 12.5% polypropylene scrim) were treated with three phosphate-nitrogen based FR formulations and evaluated with micro-scale combustion calorimetry (MCC). Heat release rate (HRR), Peak heat rate (PHRR), temperature at peak heat release ra...

  17. On the accuracy of instantaneous gas exchange rates, energy expenditure, and respiratory quotient calculations obtained in indirect whole room calorimetry

    Science.gov (United States)

    The molar balance equations of indirect calorimetry are treated from the point of view of cause-effect relationship where the gaseous exchange rates representing the unknown causes heed to be inferred from a known noisy effect – gaseous concentrations. Two methods of such inversion are analyzed. Th...

  18. HEAT OF HYDRATION OF SALTSTONE MIXES-MEASUREMENT BY ISOTHERMAL CALORIMETRY

    International Nuclear Information System (INIS)

    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

  19. Establishment of calorimetry based absorbed dose standard for newly installed Elekta Synergy accelerator at ARPANSA

    International Nuclear Information System (INIS)

    An Elekta Synergy Linear Accelerator providing 7 photon energies from 4 MeV to 25 MeV and 10 electron energies from 4MeV to 22 MeV was installed at the beginning of 2009 to provide calibration services to radiotherapy centres in the country.This accelerator is similar to the one that has been installed at NPL around the same time. After the acceptance testing and commissioning, calorimetry measurements of the photon beams at nominal energies of 6 MeV, 10 MeV and 18 MeV to establish the Australian Primary standard of absorbed dose have been done. This paper brings out the details of the measurements and the results of a bilateral intercomparison done with NPL. A graphite calorimeter procured from BEV, Austria has been established as primary standard in the '90s at the 60Co energy and a similar calorimeter loaned by IAEA has been compared giving good agreement in measurements with a 60Co source at ARPANSA. The IAEA calorimeter has been found to have better stability through a good medium control against the ambient temperature variations. This calorimeter has been used for measurements with the photon beams from the accelerator. Before the actual measurements, a study of the stability of thermistors and the electronic heater control circuitries was done through a series of electrical calibrations. The electrical calibration factor which gives the energy required to produce a fractional resistance change of the core thermistor has been found to have a constant value of -230 mJ/%R with a standard deviation of 0.4% similar to other results published for this type of calorimeter. The photon beams from the accelerator have an initial ramping dose-rate for 1-2 seconds before stabilising to a near constant value. The dose-rate profiles obtained through the output of the monitor chamber located inside the head of the accelerator is shown. The dose-rate variations are corrected in the data analysis program written in Matlab software. Calorimetry measurements have been done in

  20. Thermodynamics of the complexation of Hg(II) by cysteinyl peptide ligands using isothermal titration calorimetry

    International Nuclear Information System (INIS)

    The present study was undertaken to better understand the complexation of mercury (II) by cysteine, histidine, tryptophan, and their di- and tri-peptides. Their mercury (II) binding affinities and associated thermodynamic parameters are evaluated by isothermal titration calorimetry. Cysteine S-donor atoms form the strongest complexes, which can be attributed to a more exothermic Hg-S soft acid and soft base interaction. These thiol S-donor peptide ligands show two sequential binding for mercury (II). Their stability constants for the first binding (108 M-1 to >1010 M-1) are largely due to favorable contribution of the enthalpy term to the free energy of complexation. As more mercury (II) ions are added, this enthalpy contribution decreases and the free energy of the second binding (105 M-1 to 106 M-1) is partially compensated by the entropy term. The dependency of the fluorescence intensity for these peptides on mercury (II) concentration shows two different Stern-Volmer plots, which corroborates the calorimetric data and supports the formation of two types of stable complexes.

  1. A study of the use of lead fluoride for electromagnetic calorimetry

    International Nuclear Information System (INIS)

    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 x 5 array of 2.1 x 2.1 x 18.5 cm3 crystals has been built and tested in a test beam at the Brookhaven AGS. Results are given on energy resolution, shower size and e/π separation for electrons and pions in the range from 1--4 GeV. The light output has been measured to give approx-gt 1000 photoelectrons per MeV in good quality crystals, and to provide useful signals down to as low as 32 MeV. Measurements were also made on radiation damage in lead fluoride using 60Co gamma rays and high energy ionizing particles, as well as on thermoluminescence after irradiation. It was found that only modest damage occurs up to a level of ∼ 30 Krad in large, calorimeter size crystals, and that the damage can be easily removed by optical bleaching

  2. Alternative Calorimetry Based on the Photothermoelectric (PTE) Effect: Application to Magnetic Nanofluids

    Science.gov (United States)

    Dadarlat, Dorin; Misse, Patrick R. N.; Maignan, Antoine; Guilmeau, Emmanuel; Turcu, Rodica; Vekas, Ladislau; Tudoran, Cristian; Depriester, Michael; Sahraoui, Abdelhak Hadj

    2015-09-01

    Photothermoelectric (PTE) calorimetry was applied for the first time for thermal characterization of liquids. Both back and front detection configurations, together with the thermal-wave resonator cavity (TWRC) scanning procedure, have been used in order to measure the thermal diffusivity and thermal effusivity of a particular magnetic nanofluid: carrier liquid—transformer oil, surfactant—oleic acid, nanoparticles' type—{Fe}3{O}4.The investigations were performed as a function of the nanoparticles' concentration. Small increases of thermal diffusivity (from 9.06× 10^{-8} {m}2{\\cdot } {s}^{-1} up to 9.84× 10^{-8} {m}2{\\cdot } {s}^{-1}) and thermal effusivity (from 450 {W}{\\cdot } {s}^{1/2}{\\cdot } {m}^{-2}{\\cdot } {K}^{-1} up to 520 {W}{\\cdot } {s}^{1/2}{\\cdot } {m}^{-2}{\\cdot } {K}^{-1}) with increasing concentration of {Fe}3{O}4 nanoparticles (from 0 up to 0.623 mg {Fe}3{O}4/{ml} fluid) were observed. The comparison with the photopyroelectric (PPE) method shows that PTE and PPE give similar results but, for the moment, PPE is more accurate.

  3. Differential Scanning Calorimetry for Determining the Thermodynamic Properties of Selected Honeys

    Directory of Open Access Journals (Sweden)

    Tomaszewska-Gras Jolanta

    2015-06-01

    Full Text Available Thermodynamic properties of selected honeys: glass transition temperature (Tg, the change in specifi c heat capacity (ΔCp, and enthalpy (ΔH were analysed using differential scanning calorimetry (DSC in relation to the composition i.e. water and sugar content. Glass transition temperatures (Tg of various types of honey differed significantly (p<0.05 and ranged from -49.7°C (polyfloral to -34.8°C (sunflower. There was a strong correlation between the Tg values and the moisture content in honey (r = -0.94. The degree of crystallisation of the honey also influenced the Tg values. It has been shown that the presence or absence of sugar crystals influenced the glass transition temperature. For the decrystallised honeys, the Tg values were 6 to 11°C lower than for the crystallised honeys. The more crystallised a honey was, the greater the temperature difference was between the decrystallised and crystallized honey. In conclusion, to obtain reliable DSC results, it is crucial to measure the glass transition after the complete liquefaction of honey.

  4. Application of Differential Scanning Calorimetry (DSC in study of phase transformations in ductile iron

    Directory of Open Access Journals (Sweden)

    R. Przeliorz

    2010-04-01

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

  5. Differential scanning calorimetry study--assessing the influence of composition of vegetable oils on oxidation.

    Science.gov (United States)

    Qi, Baokun; Zhang, Qiaozhi; Sui, Xiaonan; Wang, Zhongjiang; Li, Yang; Jiang, Lianzhou

    2016-03-01

    The thermal oxidation of eight different vegetable oils was studied using differential scanning calorimetry (DSC) under non-isothermal conditions at five different heating rates (5, 7.5, 10, 12.5, and 15°C/min), in a temperature range of 100-400°C. For all oils, the activation energy (Ea) values at Tp were smaller than that at Ts and Ton. Among all the oils, refined palm oil (RPO) exhibited the highest Ea values, 126.06kJ/mol at Ts, 134.7kJ/mol at Ton, and 91.88kJ/mol at Tp. The Ea and reaction rate constant (k) values at Ts, Ton, and Tp were further correlated with oil compositions (fatty acids and triacylglycerols) using Pearson correlation analysis. The rate constant (k) and Ea of all oils exhibited varying correlations with FAs and TAGs, indicating that the thermal oxidation behaviors were affected by oil compositions. PMID:26471598

  6. Characterization of moisture-protective polymer coatings using differential scanning calorimetry and dynamic vapor sorption.

    Science.gov (United States)

    Bley, O; Siepmann, J; Bodmeier, R

    2009-02-01

    The aim of this study was to evaluate the moisture-protective ability of different polymeric coatings. Free films and film-coated tablets (with cores containing freeze-dried garlic powder) were prepared using aqueous solutions/dispersions of hydroxypropyl methylcellulose (HPMC), Opadry AMB [a poly(vinylalcohol)-based formulation] and Eudragit E PO [a poly(methacrylate-methylmethacrylate)]. The water content of the systems upon open storage at 75% relative humidity (RH) and 22 degrees C (room temperature) was followed gravimetrically. Furthermore, polymer powders, free films and coated tablets were analyzed by differential scanning calorimetry (DSC) and dynamic vapor sorption (DVS). The type of polymer strongly affected the resulting water uptake kinetics of the free films and coated tablets. DSC analysis revealed whether or not significant physical changes occurred in the coatings during storage, and whether the water vapor permeability was water concentration dependent. Using DVS analysis the critical glass transition RH of Opadry AMB powder and Opadry AMB-coated tablets at 25 degrees C could be determined: 44.0% and 72.9% RH. Storage below these threshold values significantly reduces water penetration. Thus, DVS and DSC measurements can provide valuable information on the nature of polymers used for moisture protection. PMID:18481311

  7. Single-strand DNA translation initiation step analyzed by Isothermal Titration Calorimetry

    International Nuclear Information System (INIS)

    Is single-strand DNA translatable? Since the 60s, the question still remains whether or not DNA could be directly translated into protein. Some discrepancies in the results were reported about functional translation of single-strand DNA but all results converged on a similar behavior of RNA and ssDNA in the initiation step. Isothermal Titration Calorimetry method was used to determine thermodynamic constants of interaction between single-strand DNA and S30 extract of Escherichia coli. Our results showed that the binding was not affected by the nature of the template tested and the dissociation constants were in the same range when ssDNA (Kd = 3.62 ± 2.1 x 10-8 M) or the RNA corresponding sequence (Kd = 2.7 ± 0.82 x 10-8 M) bearing SD/ATG sequences were used. The binding specificity was confirmed by antibiotic interferences which block the initiation complex formation. These results suggest that the limiting step in translation of ssDNA is the elongation process.

  8. Isothermal calorimetry: a predictive tool to model drug-propellant interactions in pressurized metered dose systems.

    Science.gov (United States)

    Ooi, Jesslynn; Gaisford, Simon; Boyd, Ben J; Young, Paul M; Traini, Daniela

    2014-01-30

    The purpose of this work was to evaluate gas perfusion isothermal calorimetry (ITC) as a method to characterize the physicochemical changes of active pharmaceutical ingredients (APIs) intended to be formulated in pressurized metered dose inhalers (pMDIs) after exposure to a model propellant. Spray dried samples of beclomethasone dipropionate (BDP) and salbutamol sulphate (SS) were exposed to controlled quantities of 2H,3H-decafluoropentane (HPFP) to determine whether ITC could be used as a suitable analytical method for gathering data on the behavioural properties of the powders in real time. The crystallization kinetics of BDP and the physiochemical properties of SS were successfully characterized using ITC and supported by a variety of other analytical techniques. Correlations between real and model propellant systems were also established using hydrofluoroalkane (HFA-227) propellant. In summary, ITC was found to be suitable for gathering data on the crystallization kinetics of BDP and SS. In a wider context, this work will have implications on the use of ITC for stability testing of APIs in HFA-based pMDIs. PMID:24325938

  9. Van ‘t Hoff global analyses of variable temperature isothermal titration calorimetry data

    International Nuclear Information System (INIS)

    Highlights: ▶ We developed a global fitting strategy for ITC data collected at multiple temperatures. ▶ This method does not require prior knowledge of the binding mechanism. ▶ Monte Carlo simulations show that the approach improves the accuracy of extracted thermodynamic parameters. ▶ The method is used to study coupled folding/binding in aminoglycoside 6′-N-acetyltransferase-Ii. - Abstract: Isothermal titration calorimetry (ITC) can provide detailed information on the thermodynamics of biomolecular interactions in the form of equilibrium constants, KA, and enthalpy changes, ΔHA. A powerful application of this technique involves analyzing the temperature dependences of ITC-derived KA and ΔHA values to gain insight into thermodynamic linkage between binding and additional equilibria, such as protein folding. We recently developed a general method for global analysis of variable temperature ITC data that significantly improves the accuracy of extracted thermodynamic parameters and requires no prior knowledge of the coupled equilibria. Here we report detailed validation of this method using Monte Carlo simulations and an application to study coupled folding and binding in an aminoglycoside acetyltransferase enzyme.

  10. Van 't Hoff global analyses of variable temperature isothermal titration calorimetry data

    Energy Technology Data Exchange (ETDEWEB)

    Freiburger, Lee A.; Auclair, Karine [Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, Canada H3A 2K6 (Canada); Mittermaier, Anthony K., E-mail: anthony.mittermaier@mcgill.ca [Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec, Canada H3A 2K6 (Canada)

    2012-01-10

    Highlights: Black-Right-Pointing-Triangle We developed a global fitting strategy for ITC data collected at multiple temperatures. Black-Right-Pointing-Triangle This method does not require prior knowledge of the binding mechanism. Black-Right-Pointing-Triangle Monte Carlo simulations show that the approach improves the accuracy of extracted thermodynamic parameters. Black-Right-Pointing-Triangle The method is used to study coupled folding/binding in aminoglycoside 6 Prime -N-acetyltransferase-Ii. - Abstract: Isothermal titration calorimetry (ITC) can provide detailed information on the thermodynamics of biomolecular interactions in the form of equilibrium constants, K{sub A}, and enthalpy changes, {Delta}H{sub A}. A powerful application of this technique involves analyzing the temperature dependences of ITC-derived K{sub A} and {Delta}H{sub A} values to gain insight into thermodynamic linkage between binding and additional equilibria, such as protein folding. We recently developed a general method for global analysis of variable temperature ITC data that significantly improves the accuracy of extracted thermodynamic parameters and requires no prior knowledge of the coupled equilibria. Here we report detailed validation of this method using Monte Carlo simulations and an application to study coupled folding and binding in an aminoglycoside acetyltransferase enzyme.

  11. Quantifying the rates of relaxation of binary mixtures of amorphous pharmaceuticals with isothermal calorimetry.

    Science.gov (United States)

    Alem, Naziha; Beezer, Anthony E; Gaisford, Simon

    2010-10-31

    While the use of isothermal calorimetry to quantify the rate of relaxation of one-phase amorphous pharmaceuticals, through application of models, is well documented, the resolution of the models to detect and quantify relaxation in systems containing two independent amorphous phases is not known. Addressing this knowledge gap is the focus of this work. Two fitting models were tested; the Kohlrausch-Williams-Watts model (KWW) and the modified-stretch exponential (MSE). The ability of each model to resolve relaxation processes in binary systems was determined with simulated calorimetric data. It was found that as long as the relaxation time constants of the relaxation processes were with 10(3) of each other, the models could determine that two events were occurring and could quantify the correct reaction parameters of each. With greater differences in the time constants, the faster process always dominates the data and the resolving power of the models is lost. Real calorimetric data were then obtained for two binary amorphous systems (sucrose-lactose and sucrose-indomethacin mixtures). The relaxation behaviour of all the single components was characterised as they relaxed individually to provide reference data. The ability of the KWW model to recover the expected relaxation parameters for two component data was impaired because of their inherently noisy nature. The MSE model reasonably recovered the expected parameters for each component for the sucrose-indomethacin system but not for the sucrose-lactose system, which may indicate a possible interaction in that case. PMID:20655372

  12. Simultaneous Differential Scanning Calorimetry and Thermogravimetric Analysis of Portland Cement as a Function of Age

    Science.gov (United States)

    Trník, Anton; Scheinherrová, Lenka; Kulovaná, Tereza; Černý, Robert

    2016-01-01

    We study the hydration and pozzolanic reactions of an ordinary Portland cement as a function of age, using the differential scanning calorimetry and thermogravimetry. The measurements are done for 2 days, 7 days, 28 days, 90 days, 180 days, and 360 days cured samples in order to monitor the rate of hydration. The investigation is performed in the temperature range from 25° C to 1000° C with a heating rate 5° C {\\cdot} min^{-1} in an argon atmosphere. The temperature, enthalpy, and mass change during the decomposition of calcium silicate hydrate gels, ettringite, portlandite, vaterite, and calcite are determined, and the changes in the portlandite amount are estimated in dependence on the time of hydration. We found out that the temperature and enthalpy of liberation of physically bound water, C-S-H gels and ettringite decomposition (all occurring from 50° C to 250° C) and Portlandite decomposition (420° C to 530° C) decrease with hydration time of studied samples. On the other hand, vaterite and calcite decomposition (530° C to 850° C) the temperature varies and the enthalpy increases with hydration time of samples.

  13. A novel optical calorimetry dosimetry approach applied to an HDR Brachytherapy source

    International Nuclear Information System (INIS)

    The technique of Digital Holographic Interferometry (DHI) is applied to the measurement of radiation absorbed dose distribution in water. An optical interferometer has been developed that captures the small variations in the refractive index of water due to the radiation induced temperature increase ΔT. The absorbed dose D is then determined with high temporal and spatial resolution using the calorimetric relation D=cΔT (where c is the specific heat capacity of water). The method is capable of time resolving 3D spatial calorimetry. As a proof-of-principle of the approach, a prototype DHI dosimeter was applied to the measurement of absorbed dose from a High Dose Rate (HDR) Brachytherapy source. Initial results are in agreement with modelled doses from the Brachyvision treatment planning system, demonstrating the viability of the system for high dose rate applications. Future work will focus on applying corrections for heat diffusion and geometric effects. The method has potential to contribute to the dosimetry of diverse high dose rate applications which require high spatial resolution such as microbeam radiotherapy (MRT) or small field proton beam dosimetry but may potentially also be useful for interface dosimetry.

  14. A Guide to Differential Scanning Calorimetry of Membrane and Soluble Proteins in Detergents.

    Science.gov (United States)

    Yang, Zhengrong; Brouillette, Christie G

    2016-01-01

    Differential scanning calorimetry (DSC) detects protein thermal unfolding by directly measuring the heat absorbed. Simple DSC experiments that require relatively small amounts of pure material can provide a wealth of information related to structure, especially with respect to domain architecture, without the need for a complete thermodynamic analysis. Thus, DSC is an ideal additional tool for membrane protein characterization and also offers several advantages over indirect thermal unfolding methods. Integral membrane proteins (IMPs) that comprise both large multitopic transmembrane domains (TMDs) and extramembranous domains (EMDs) are differentially affected by detergent interactions with both domains. In fact, in some cases, destabilization of the EMD by detergent may dominate overall IMP stability. This chapter will (1) provide a perspective on the advantages of DSC for membrane protein characterization and stability measurements, including numerous examples spanning decades of research; (2) introduce models for the interaction and destabilization of IMPs by detergents; (3) discuss two case studies from the authors' lab; and (4) offer practical advice for performing DSC in the presence of detergents. PMID:26794360

  15. Application of Differential Scanning Calorimetry to Evaluate Thermal Properties and Study of Microstructure of Biodegradable Films

    Science.gov (United States)

    Aguilar-Méndez, M. A.; Martin-Martínez, E. San; Ortega-Arroyo, L.; Cruz-Orea, A.

    2010-03-01

    The glass transition temperature ( T g) and melting temperature ( T m) of gelatin-starch films were determined using differential scanning calorimetry. Also, the microstructure was observed using scanning electron microscopy (SEM) and the crystalline structure by means of X-ray diffraction (XRD). The effect of starch and glycerol concentrations in films on the thermal properties was evaluated through response surface methodology (RSM). The highest values of T m were obtained at starch concentration intervals of (0.26 to 0.54) %w/w and glycerol concentrations lower than 0.5 (%w/w). On the other hand, the T g values diminished as the glycerol concentration increased. Mathematical models for both transitions were fitted to the experimental data. The micrographs obtained by SEM show the influence of glycerol in the microstructure of the films, being more “gummy” as the content of the plasticizer increased. The XRD patterns of the films demonstrate the existence of some pseudo-crystalline regions in the biodegradable materials.

  16. Thermodynamic study of Th(IV) complexes with dicarboxylates by potentiometry and calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Rawat, N.; Nishad, A.; Tomar, B.S.; Manchanda, V.K. [Bhabha Atomic Research Centre, Mumbai (India). Radiochemistry Div.; Sharma, R.S. [Bhabha Atomic Research Centre, Mumbai (India). Research Reactor Services Div.

    2011-07-01

    The thermodynamic quantities ({delta}G{sub c}, {delta}H{sub c} and {delta}S{sub c}) for formation of Th(IV) complexes with dicarboxylic ligands, namely, malonate, succinate, glutarate and adipate were determined using potentiometry and calorimetry. The protonation constants of the dicarboxylate ligands were determined by potentiometric titration of the ligand solution, while the corresponding enthalpy values were taken from the literature. In the case of Th(IV)-malonate, multiple species (ML{sub j}, j = 1-3) were revealed from the potentiometric data, while in the case of higher homologues, the data for only 1:1 complex could be obtained owing to precipitation at higher ligand concentration. The effect of chain length on the thermodynamic parameters of Th(IV)-dicarboxylate complexation was studied. All the complexation reactions were found to be highly entropy driven, which is the characteristic of the hard acid (metal ion) and hard base (ligand) interactions. The T{delta}S{sub c} values for 1:1 complexes were found to be nearly constant while the {delta}H{sub c} values increased from malonate to glutarate and then leveled off in adipate. The thermodynamic data of Th(IV) have been compared with corresponding data for U(VI) and rare earths. (orig.)

  17. Binding of copper to lysozyme: Spectroscopic, isothermal titration calorimetry and molecular docking studies.

    Science.gov (United States)

    Jing, Mingyang; Song, Wei; Liu, Rutao

    2016-07-01

    Although copper is essential to all living organisms, its potential toxicity to human health have aroused wide concerns. Previous studies have reported copper could alter physical properties of lysozyme. The direct binding of copper with lysozyme might induce the conformational and functional changes of lysozyme and then influence the body's resistance to bacterial attack. To better understand the potential toxicity and toxic mechanisms of copper, the interaction of copper with lysozyme was investigated by biophysical methods including multi-spectroscopic measurements, isothermal titration calorimetry (ITC), molecular docking study and enzyme activity assay. Multi-spectroscopic measurements proved that copper quenched the intrinsic fluorescence of lysozyme in a static process accompanied by complex formation and conformational changes. The ITC results indicated that the binding interaction was a spontaneous process with approximately three thermodynamical binding sites at 298K and the hydrophobic force is the predominant driven force. The enzyme activity was obviously inhibited by the addition of copper with catalytic residues Glu 35 and Asp 52 locating at the binding sites. This study helps to elucidate the molecular mechanism of the interaction between copper and lysozyme and provides reference for toxicological studies of copper. PMID:27089183

  18. Binding of copper to lysozyme: Spectroscopic, isothermal titration calorimetry and molecular docking studies

    Science.gov (United States)

    Jing, Mingyang; Song, Wei; Liu, Rutao

    2016-07-01

    Although copper is essential to all living organisms, its potential toxicity to human health have aroused wide concerns. Previous studies have reported copper could alter physical properties of lysozyme. The direct binding of copper with lysozyme might induce the conformational and functional changes of lysozyme and then influence the body's resistance to bacterial attack. To better understand the potential toxicity and toxic mechanisms of copper, the interaction of copper with lysozyme was investigated by biophysical methods including multi-spectroscopic measurements, isothermal titration calorimetry (ITC), molecular docking study and enzyme activity assay. Multi-spectroscopic measurements proved that copper quenched the intrinsic fluorescence of lysozyme in a static process accompanied by complex formation and conformational changes. The ITC results indicated that the binding interaction was a spontaneous process with approximately three thermodynamical binding sites at 298 K and the hydrophobic force is the predominant driven force. The enzyme activity was obviously inhibited by the addition of copper with catalytic residues Glu 35 and Asp 52 locating at the binding sites. This study helps to elucidate the molecular mechanism of the interaction between copper and lysozyme and provides reference for toxicological studies of copper.

  19. Changes in polymer foils used in food packaging tested by using differential scanning calorimetry

    Indian Academy of Sciences (India)

    J Gajdoš Kljusurić

    2003-12-01

    This work is an experimental study of the differential scanning calorimetry characterisation of polymer materials used in food packaging materials, such as polypropylene (0.03 mm), polyethylene (0.1 and 0.03 mm), poly(D-(-)--hydroxybutyrate) (powder), two-layered polypropylene (0.064 mm), and two-layered polypropylene with poly-vinylidene-chloride (0.012/0.021). The polymer stability was checked by simulation of conditions during food preparation in microwave ovens, sterilisation or rapid freezing. The materials were tested in the temperature range from 40 to 200°C at different scan rates from 2 to 30° C min-1 during heating or cooling. The enthalpies show a high correlation coefficient (0.964) with scan rate. All samples undergo phase change in the temperature range from 107 to 173°C during heating and enthalpies are in the range from 31.8 to 71.1 J g−1 Upon subsequent cooling from 200°C, the temperature range of phase changes is shifted to lower temperatures from 86 to 102°C with enthalpies ranging from 30.4 to 57.8 J g−1. Experiments with exposure of polymers to microwave radiation and freezing prove that the phase change considering the temperature range is very similar in all experiments.

  20. High Temperature Heat Capacity of Alloy D9 Using Drop Calorimetry Based Enthalpy Increment Measurements

    Science.gov (United States)

    Banerjee, Aritra; Raju, S.; Divakar, R.; Mohandas, E.

    2007-02-01

    Alloy D9 is a void-swelling resistant nuclear grade austenitic stainless steel (SS) based on AISI type 316-SS in which titanium constitutes an added predetermined alloying composition. In the present study, the high-temperature enthalpy values of alloy D9 with three different titanium-to-carbon mass percent ratios, namely Ti/C = 4, 6, and 8, have been measured using inverse drop calorimetry in the temperature range from 295 to 1323 K. It is found that within the level of experimental uncertainty, the enthalpy values are independent of the Ti-C mass ratio. The temperature dependence of the isobaric specific heat C P is obtained by a linear regression of the measured enthalpy data. The measured C P data for alloy D9 may be represented by the following best-fit expression: C_P(J \\cdot kg^{-1}\\cdot K^{-1})= 431 + 17.7 × 10^{-2}T + 8.72 × 10^{-5}/T^2. It is found that the measured enthalpy and specific heat values exhibit good agreement with reported data on 316 and other related austenitic stainless steels.

  1. Thermodynamic Study on the Protonation Reactions of Glyphosate in Aqueous Solution: Potentiometry, Calorimetry and NMR spectroscopy.

    Science.gov (United States)

    Liu, Bijun; Dong, Lan; Yu, Qianhong; Li, Xingliang; Wu, Fengchang; Tan, Zhaoyi; Luo, Shunzhong

    2016-03-10

    Glyphosate [N-(phosphonomethyl)glycine] has been described as the ideal herbicide because of its unique properties. There is some conflicting information concerning the structures and conformations involved in the protonation process of glyphosate. Protonation may influence the chemical and physical properties of glyphosate, modifying its structure and the chemical processes in which it is involved. To better understand the species in solution associated with changes in pH, thermodynamic study (potentiometry, calorimetry and NMR spectroscopy) about the protonation pathway of glyphosate is performed. Experimental results confirmed that the order of successive protonation sites of totally deprotonated glyphosate is phosphonate oxygen, amino nitrogen, and finally carboxylate oxygen. This trend is in agreement with the most recent theoretical work in the literature on the subject ( J. Phys. Chem. A 2015, , 119 , 5241 - 5249 ). The result is important because it confirms that the protonated site of glyphosate in pH range 7-8, is not on the amino but on the phosphonate group instead. This corrected information can improve the understanding of the glyphosate chemical and biochemical action. PMID:26862689

  2. A Universal Method for Fishing Target Proteins from Mixtures of Biomolecules using Isothermal Titration Calorimetry

    International Nuclear Information System (INIS)

    The most challenging tasks in biology include the identification of (1) the orphan receptor for a ligand, (2) the ligand for an orphan receptor protein, and (3) the target protein(s) for a given drug or a lead compound that are critical for the pharmacological or side effects. At present, several approaches are available, including cell- or animal-based assays, affinity labeling, solid-phase binding assays, surface plasmon resonance, and nuclear magnetic resonance. Most of these techniques are not easy to apply when the target protein is unknown and the compound is not amenable to labeling, chemical modification, or immobilization. Here we demonstrate a new universal method for fishing orphan target proteins from a complex mixture of biomolecules using isothermal titration calorimetry (ITC) as a tracking tool. We took snake venom, a crude mixture of several hundred proteins/peptides, as a model to demonstrate our proposed ITC method in tracking the isolation and purification of two distinct target proteins, a major component and a minor component. Identities of fished out target proteins were confirmed by amino acid sequencing and inhibition assays. This method has the potential to make a significant advancement in the area of identifying orphan target proteins and inhibitor screening in drug discovery and characterization.

  3. Effect of hydration on the thermal stability of protein as measured by differential scanning calorimetry

    International Nuclear Information System (INIS)

    The thermal denaturation of the deuterated lysozyme has been investigated by differential scanning calorimetry in the range of deuterium oxide (D2O) content from 0.03 to 1.6 g of D2O per g of protein. At D2O contents above 0.55 g/g, the temperature, T sub(d), and enthalpy change, ΔH sub(d), of denaturation were almost independent of the degree of hydration. At lower D2O contents, however, both T sub(d) and ΔH sub(d) showed marked dependence on the degree of hydration. The values of T sub(d) increased with a decrease in the D2O content. Whereas the values of ΔH sub(d) decreased with a decrease in the D2O content in the same region. The degree of hydration dependency of ΔH sub(d) exhibited a break at approximately 170 mol/mol, which indicates that at least two types of hydration contributes to the thermal stability of the protein. The conformational enthalpy change of the protein and the enthalpy change of the hydration layer have also been estimated from the degree of hydration dependency of ΔH sub(d). The results have been compared with those of the lysozyme-H2O system. (author)

  4. Thermal runaway features of large format prismatic lithium ion battery using extended volume accelerating rate calorimetry

    Science.gov (United States)

    Feng, Xuning; Fang, Mou; He, Xiangming; Ouyang, Minggao; Lu, Languang; Wang, Hao; Zhang, Mingxuan

    2014-06-01

    In this paper, the thermal runaway features of a 25 Ah large format prismatic lithium ion battery with Li(NixCoyMnz)O2 (NCM) cathode are evaluated using the extended volume-accelerating rate calorimetry (EV-ARC). 4 thermocouples are set at different positions of the battery. The temperature inside the battery is 870 °C or so, much higher than that outside the battery. The temperature difference is calculated from the recorded data. The temperature difference within the battery stays lower than 1 °C for 97% of the test period, while it rises to its highest, approximately 520 °C, when thermal runaway happens. The voltage of the battery is also measured during the test. It takes 15-40 s from the sharp drop of voltage to the instantaneous rise of temperature. Such a time interval is beneficial for early warning of the thermal runaway. Using a pulse charge/discharge profile, the internal resistance is derived from the quotient of the pulse voltage and the current during the ARC test. The internal resistance of the battery increases slowly from 20 mΩ to 60 mΩ before thermal runaway, while it rises to 370 mΩ when thermal runaway happens indicating the loss of the integrity of the separator or the battery swell.

  5. First application of simultaneous SANS and differential scanning calorimetry: Microphase separated alkane blends

    International Nuclear Information System (INIS)

    For almost 30 years, it has been possible at synchrotron facilities to perform small-angle x-ray scattering experiments whilst simultaneously measuring phase transitions using differential scanning calorimetry (DSC). However, a range of challenges exist to enable the collection of simultaneous small-angle neutron scattering (SANS) and DSC data associated not only with intrinsic flux limitations but also scattering geometry and thermal control. The development of a DSC (temperature range ca. −150 C to 500 C) suitable for SANS is detailed here which, to our knowledge, is the first and only one of its kind. An example study is presented from the 40 m SANS instrument, QUOKKA, at the OPAL reactor at ANSTO (Figure 1), concerned with phase transitions in a binary blend of normal alkanes in which one component has been deuterium labelled[1]. The ability to conduct simultaneous DSC and neutron scattering studies allows investigators to use these two complementary techniques to provide insight into structural and thermal changes and opens up the opportunity for SANS to make significant new contributions to a range of systems in which either scattering contrast is insufficient for SAXS studies or where neutron scattering is essential or inherently desirable (e.g. isotope effects).

  6. AC Calorimetry and Thermophysical Properties of Bulk Glass-Forming Metallic Liquids

    Science.gov (United States)

    Johnson, William L.

    2000-01-01

    Thermo-physical properties of two bulk metallic glass forming alloys, Ti34Zr11Cu47Ni8 (VIT 101) and Zr57Nb5Ni12.6Al10CU15.4 (VIT 106), were investigated in the stable and undercooled melt. Our investigation focused on measurements of the specific heat in the stable and undercooled liquid using the method of AC modulation calorimetry. The VIT 106 exhibited a maximum undercooling of 140 K in free radiative cooling. Specific heat measurements could be performed in stable melt down to an undercooling of 80 K. Analysis of the specific heat data indicate an anomaly near the equilibrium liquidus temperature. This anomaly is also observed in y the temperature dependencies of the external relaxation time, the specific volume, and the surface tension; it is tentatively attributed to a phase separation in the liquid state. The VIT 101 specimen exhibited a small undercooling of about 50 K. Specific heat measurements were performed in the stable and undercooled melt. These various results will be combined with ground based work such as the measurement of T-T-T curves in the electrostatic levitator and low temperature viscosity and specific heat measurements for modeling the nucleation kinetics of these alloys.

  7. Application of isothermal titration calorimetry as a tool to study natural product interactions.

    Science.gov (United States)

    Callies, O; Hernández Daranas, A

    2016-07-28

    Covering: up to February 2015Over the past twenty-five years, isothermal titration calorimetry (ITC) has become a potent tool for the study a great variety of molecular interactions. This technique is able to provide a complete thermodynamic profile of an interaction process in a single experiment, with a series of advantages in comparison to other comparable techniques, such as less amount of sample or no need of chemical modification or labelling. It is thus not surprising that ITC has been applied to study the manifold types of interactions of natural products to get new insights into the molecular key factors implied in the complexation process of this type of compounds. This review provides an overview over the applications of ITC as a potent tool to investigate interactions of natural products with proteins, nucleic acids, oligosaccharides, and other types of receptors. The examples have been selected depending on the impact that this technique had during the investigation and revision of the interactions involved in the bioactivity of a compound, lead optimization or technical applications. PMID:27186603

  8. Study of temperature dependent zirconium silicide phases in Zr/Si structure by differential scanning calorimetry

    International Nuclear Information System (INIS)

    The differential scanning calorimetry (DSC) technique is employed to study the formation of different silicide compounds of Zr thin-film deposited on a 100 μm-thick Si (1 0 0) substrate by dc sputtering. A detailed analysis shows that silicide layers start growing at  ∼246 °C that changes to stable ZrSi2 at 627 °C via some compounds with different stoichiometric ratios of Zr and Si. It is further observed that oxygen starts reacting with Zr at  ∼540 °C but a stoichiometric ZrO2 film is formed after complete consumption of Zr metal at 857 °C. A further rise in temperature changes a part of ZrSi2 to Zr-Silicate. The synchrotron radiation-based grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy studies also corroborate the above findings. Atomic force microscopy is also carried out on the samples. It is evident from the observations that an intermixing and nucleation of Zr and Si occur at lower temperature prior to the formation of the interfacial silicate layer. Zr-Silicate formation takes place only at a higher temperature. (paper)

  9. CALOCUBE: an approach to high-granularity and homogenous calorimetry for space based detectors

    International Nuclear Information System (INIS)

    Future space experiments dedicated to the observation of high-energy gamma and cosmic rays will increasingly rely on a highly performing calorimetry apparatus, and their physics performance will be primarily determined by the geometrical dimensions and the energy resolution of the calorimeter deployed. Thus it is extremely important to optimize its geometrical acceptance, the granularity, and its absorption depth for the measurement of the particle energy with respect to the total mass of the apparatus which is the most important constraint for a space launch. The proposed design tries to satisfy these criteria while staying within a total mass budget of about 1.6 tons. Calocube is a homogeneous calorimeter instrumented with Cesium iodide (CsI) crystals, whose geometry is cubic and isotropic, so as to detect particles arriving from every direction in space, thus maximizing the acceptance; granularity is obtained by filling the cubic volume with small cubic CsI crystals. The total radiation length in any direction is more than adequate for optimal electromagnetic particle identification and energy measurement, whilst the interaction length is at least suficient to allow a precise reconstruction of hadronic showers. Optimal values for the size of the crystals and spacing among them have been studied. The design forms the basis of a three-year R and D activity which has been approved and financed by INFN. An overall description of the system, as well as results from preliminary tests on particle beams will be described

  10. Study on the Interaction of Zinc Ion Binding with Human Serum Albumin using Isothermal Titration Calorimetry

    International Nuclear Information System (INIS)

    The interaction between zinc ion and human serum albumin (HSA) was investigated by nano-Watt- scale isothermal titration calorimetry (ITC). From the analysis of the ITC data, the binding characteristics and thermodynamic properties of the system were obtained and the binding mechanism was discussed. It was found that the experimental data fit well with the Langmuir's binding theory and the system behaved as a system with two classes of binding sites (high-affinity and low-affinity binding site). The binding number of high-affinity binding site (N1) is 1.40 and the binding constant (K1) is 2.72*105 L/mol. For the low-affinity binding site, the binding number (N2) is 1.55 and the binding constant (K2) is 3.78*103 L/mol. Moreover, it was indicated by the thermodynamic analysis that the binding processes of both types of binding sites were exothermic and spontaneous. The high-affinity binding was an enthalpy-entropy synergically driven process and the electrostatic interaction was the main force, while the low-affinity binding was an enthalpy driven process and this process was mainly driven by the van der Waals forces. (author)

  11. Studies on sampling and homogeneous dual readout calorimetry with meta-crystals

    CERN Document Server

    Mavromanolakis, G; Lecoq, P

    2011-01-01

    The meta-crystals concept is an approach that consists of using both undoped and properly doped heavy crystal fibers of identical material as the active medium of a calorimeter. The undoped fibers behave as Cherenkov radiators while the doped ones behave as scintillators. A dual readout calorimeter can be built with its sensitive volume composed of a mixture of both types of crystals. In addition if the calorimeter is adequately finely segmented it can also function as a particle flow calorimeter at the same time. In this way one could possibly combine the advantages of both the particle flow concept and the dual readout scheme. We discuss the approach of dual readout calorimetry with meta-crystals made of Lutetium Aluminium Garnet (LuAG). We brie fly present studies on the material development and first testbeam activities and then focus on performance expectation studies based on simulation. We discuss in more detail the results from generic systematic scannings of the design parameters of a dual readout ca...

  12. Ring-shaped Calorimetry Information for a Neural eGamma Identification with ATLAS Detector

    CERN Document Server

    Da Fonseca Pinto, Joao Victor; The ATLAS collaboration; Oliveira Damazio, Denis; Seixas, Jose

    2016-01-01

    \\title{Ring-shaped Calorimetry Information for a Neural e/$\\gamma$ Identification with ATLAS Detector} After the successful operation of the Large Hadron Collider resulting with the discovery of the Higgs boson, a new data-taking period (Run 2) has started. For the first time, collisions are produced with energies of 13 TeV in the centre of mass. It is foreseen the luminosity increase, reaching values as high as $10^{34}cm^{-2}s^{-1}$ yet in 2015. These changes in experimental conditions bring a proper environment for possible new physics key-findings. ATLAS is the largest LHC detector and was designed for general-purpose physics studies. Many potential physics channels have electrons or photons in their final states. For efficient studies on these channels precise measurement and identification of such particles is necessary. The identification task consists of disentangling those particles (signal) from collimated hadronic jets (background). Reported work concerns the identification process based on the cal...

  13. Recent advances and potential applications of modulated differential scanning calorimetry (mDSC) in drug development.

    Science.gov (United States)

    Knopp, Matthias Manne; Löbmann, Korbinian; Elder, David P; Rades, Thomas; Holm, René

    2016-05-25

    Differential scanning calorimetry (DSC) is frequently the thermal analysis technique of choice within preformulation and formulation sciences because of its ability to provide detailed information about both the physical and energetic properties of a substance and/or formulation. However, conventional DSC has shortcomings with respect to weak transitions and overlapping events, which could be solved by the use of the more sophisticated modulated DSC (mDSC). mDSC has multiple potential applications within the pharmaceutical field and the present review provides an up-to-date overview of these applications. It is aimed to serve as a broad introduction to newcomers, and also as a valuable reference for those already practising in the field. Complex mDSC was introduced more than two decades ago and has been an important tool for the quantification of amorphous materials and development of freeze-dried formulations. However, as discussed in the present review, a number of other potential applications could also be relevant for the pharmaceutical scientist. PMID:26721421

  14. PREFACE: XVth International Conference on Calorimetry in High Energy Physics (CALOR2012)

    Science.gov (United States)

    Akchurin, Nural

    2012-12-01

    The XVth International Conference on Calorimetry in High Energy Physics, CALOR2012, was held in Santa Fe, New Mexico from 4-8 June 2012. The series of conferences on calorimetry started in 1990 at Fermilab, and they have been the premier event for calorimeter aficionados, a trend that CALOR2012 upheld. This year, several presentations focused on the status of the major calorimeter systems, especially at the LHC. Discussions on new and developing techniques in calorimetry took a full day. Excellent updates on uses of calorimeters or about ideas that are deeply rooted in particle physics calorimetry in astrophysics and neutrino physics were followed by talks on algorithms and special triggers that rely on calorimeters. Finally, discussions of promising current developments and ongoing R&D work for future calorimeters capped the conference. The field of calorimetry is alive and well, as evidenced by the more than 100 attendees and the excellent quality of over 80 presentations. You will find the written contributions in this volume. The presentations can be found at calor2012.ttu.edu. The first day of the conference was dedicated to the LHC. In two invited talks, Guillaume Unal (CERN) and Tommaso Tabarelli de Fatis (Universita' & INFN Milano Bicocca) discussed the critical role electromagnetic calorimeters play in the hunt for the Standard Model Higgs boson in ATLAS and CMS, respectively. The enhanced sensitivity for light Higgs in the two-gamma decay channel renders electromagnetic calorimeters indispensible. Much of the higher mass region was already excluded for the SM Higgs by the time of this conference, and after less than a month, on 4 July, CERN announced the discovery of a new boson at 125 GeV, a particle that seems consistent with the Higgs particle so far. Once again, without the electromagnetic calorimeters, this would not have been possible. Professor Geoffrey West from the Santa Fe Institute gave the keynote address. His talk, 'Universal Scaling Laws

  15. Extensive studies on CeF3 crystals, a good candidate for electromagnetic calorimetry at future accelerators

    International Nuclear Information System (INIS)

    In the framework of its search for new heavy, fast and radiation hard scintillators for calorimetry at future colliders, the Crystal Clear Collaboration performed a systematic investigation of the properties and of the scintillation and radiation damage mechanisms of CeF3 monocrystals. Many samples of various dimensions up to 3 x 3 x 28 cm3 were produced by industry and characterised in the laboratories by different methods such as: optical transmission, light yield and decay time measurements, excitation and emission spectra, gamma and neutron irradiations. The results of these measurements are discussed. The measured light yield is compared to the theoretical expectations. Tests in high energy electron beams on a crystal matrix were also performed. The suitability of CeF3 for calorimetry at high rate machines is confirmed. Production and economical considerations are discussed. (orig.)

  16. Application of the modulated temperature differential scanning calorimetry technique for the determination of the specific heat of copper nanofluids

    International Nuclear Information System (INIS)

    The purpose of this work is to investigate the applicability of the modulated temperature differential scanning calorimetry technique to measure specific heat of copper nanofluids by using the ASTM E2719 standard procedure, which is generally applied to thermally stable solids and liquids. The one-step method of preparation of copper nanofluid samples is described. The synthesized nanoparticles were separated from the base fluid and examined by X-ray diffraction and transmission electron microscopy in order to evaluate their structure, morphology and chemical nature. The presence of copper nanoparticles in the base fluid alters the characteristics of crystallization and melting processes and reduces the specific heat values of nanofluids in the whole studied temperature range. - Highlights: ► Copper nanofluids prepared by one-step method. ► Methodology of synthesis improved nanofluid stability. ► Specific heat determinations using modulated temperature differential scanning calorimetry. ► Good agreement between theoretical and experimental values.

  17. Kinetics of solid-gas reactions characterized by scanning AC nano-calorimetry with application to Zr oxidation

    International Nuclear Information System (INIS)

    Scanning AC nano-calorimetry is a recently developed experimental technique capable of measuring the heat capacity of thin-film samples of a material over a wide range of temperatures and heating rates. Here, we describe how this technique can be used to study solid-gas phase reactions by measuring the change in heat capacity of a sample during reaction. We apply this approach to evaluate the oxidation kinetics of thin-film samples of zirconium in air. The results confirm parabolic oxidation kinetics with an activation energy of 0.59 ± 0.03 eV. The nano-calorimetry measurements were performed using a device that contains an array of micromachined nano-calorimeter sensors in an architecture designed for combinatorial studies. We demonstrate that the oxidation kinetics can be quantified using a single sample, thus enabling high-throughput mapping of the composition-dependence of the reaction rate.

  18. Breath test measurements in combination with indirect calorimetry for estimation of 13C-leucine oxidation in mink (Mustela vison)

    DEFF Research Database (Denmark)

    Tauson, Anne-Helene; Ali, Abdalla; Kanska, Katarzyna;

    2000-01-01

    Gas exchange measurements by means of indirect calorimetry can be used to calculate quantitative substrate oxidation. The results represents average net oxidation values (substrate disappearance rate), but they cannot describe the dynamics of the oxidation processes. Breath test measurements...... to feeding and fasting. Twelve 1-year-old male mink (Mustela vison) were measured in each five consecutive periods by means of indirect calorimetry and simultaneous breath test. In Periods 1, 3 and 5, each lasting 3 days, the animals were fed ad libitum and Periods 2 and 4 were fasting periods, each of 48 h...... before measurements started and expired air was then sucked out of the respiration chamber and collected into breath bags at frequent intervals until 5.5 h after the start of measurements. The ratio of 13C/12C was measured by means of an IRIS infrared analyser and results are reported in terms of delta...

  19. Energy dispersive x-ray diffractometry as a tool alternative to differential scanning calorimetry for investigating polymer phase transitions

    International Nuclear Information System (INIS)

    Recently, a technique based on energy dispersive x-ray diffraction has been proposed to follow the polymer phase transitions. However, the potentialities of this method were not clear, as well as the experimental conditions in which it is more convenient than differential scanning calorimetry, generally used for the same purpose. In the present letter, the answer to this question is provided. It is shown that the two methods are complementary, rather than equivalent, the heating rate being the relevant parameter to establish which is preferable. The demonstration of this statement is given through the observation of the complex thermal properties of a reference sample studied in both ways at progressively lower heating rates. The connection between such unusual application of x-ray diffraction and the differential scanning calorimetry is discussed in terms of the two possible definitions of entropy

  20. Binding of Cu(II) ions to peptides studied by fluorescence spectroscopy and isothermal titration calorimetry.

    Science.gov (United States)

    Makowska, Joanna; Żamojć, Krzysztof; Wyrzykowski, Dariusz; Uber, Dorota; Wierzbicka, Małgorzata; Wiczk, Wiesław; Chmurzyński, Lech

    2016-01-15

    Steady-state and time-resolved fluorescence quenching measurements supported by Isothermal Titration Calorimetry (ITC) were used to study the interactions of Cu(2+) with four peptides. Two of them were taken from the N-terminal part of the FBP28 protein (formin binding protein) WW domain: Tyr-Lys-Thr-Ala-Asp-Gly-Lys-Thr-Tyr-NH2 (D9) and its mutant Tyr-Lys-Thr-Ala-Asn-Gly-Lys-Thr-Tyr-NH2 (D9_M) as well as two mutated peptides from the B3 domain of the immunoglobulin binding protein G derived from Streptococcus: Asp-Val-Ala-Thr-Tyr-Thr-NH2 (J1) and Glu-Val-Ala-Thr-Tyr-Thr-NH2 (J2). The measurements were carried out at 298.15K in 20mM 2-(N-morpholino)ethanesulfonic acid (MES) buffer solution with a pH of 6. The fluorescence of all peptides was quenched by Cu(2+) ions. The stoichiometry, conditional stability constants and thermodynamic parameters for the interactions of the Cu(2+) ions with D9 and D9_M were determined from the calorimetric data. The values of the conditional stability constants were additionally determined from fluorescence quenching measurements and compared with those obtained from calorimetric studies. There was a good correlation between data obtained from the two techniques. On the other hand, the studies revealed that J1 and J2 do not exhibit an affinity towards metal ions. The obtained results prove that fluorescence quenching experiments may be successfully used in order to determine stability constants of complexes with fluorescent ligands. Finally, based on the obtained results, the coordinating properties of the peptides towards the Cu(2+) ions are discussed. PMID:26363471

  1. Evaluation of peritoneal tissue by means of differential scanning calorimetry (DSC

    Directory of Open Access Journals (Sweden)

    Łukasz Pietrzyk

    2012-01-01

    Full Text Available Abdominal surgeries alter the integrity of the peritoneal layer and cause imbalances among immunological, inflammatory and angiogenic mechanisms within the tissue. During laparoscopic procedures a protective function of the peritoneal layer can be disturbed by the gas used to create a pneumoperitoneum. The aim of this study was to characterize peritoneal tissue by means of differential scanning calorimetry (DSC as a reference for future investigations on the influence of surgical procedures on the physicochemical state of the peritoneum. Thirty-seven patients participated in the study. Patients were divided into three groups according to the type of surgery: group H — patients who underwent hernia repair; group Ch — patients who underwent laparoscopic cholecystectomy; and group C — patients operated due to rectal cancer. It was observed that onset temperature (To, denaturation temperature (Tm and change of enthalpy (ΔH during thermal denaturation of peritoneal collagen in were significantly different for these three groups of patients. The mean values of onset temperature (To and denaturation temperature (Tm in group H were significantly lower, while DH in this group was significantly higher than in the two other groups (Ch and C. This preliminary study does not answer whether the differences in collagen denaturation found in peritoneal tissue from different groups of patients resulted from a different inherent state of the tissue, or from surgical procedures. However, the results suggest that DSC is an appropriate method to study subtle changes in the physicochemical condition of the peritoneum using small samples obtained during surgical procedures. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 4, pp. 700–705

  2. Following mechanical activation of salbutamol sulphate during ball-milling with isothermal calorimetry.

    Science.gov (United States)

    Gaisford, Simon; Dennison, Mansa; Tawfik, Mahmoud; Jones, Matthew D

    2010-06-30

    Formulation of actives for pulmonary delivery with dry powder inhaler devices frequently requires a particle size reduction step. The high-energy forces imparted to a material during milling, as well as reducing particle size, can cause a significant change in physicochemical properties, in particular mechanical activation of the surface (manifested as generation of amorphous regions) which can affect formulated product performance. It is not clear whether particle size reduction occurs prior to, or concomitantly with, generation of amorphous content. In this study the formation of amorphous content with time in crystalline salbutamol sulphate was quantified with isothermal gas perfusion calorimetry as the sample was ball-milled. The data showed that the most particle size reduction occurred initially (d(0.5) dropping from 12.83+/-0.4 to 4.2+/-0.4 within 5 min). During this time period, no detectable amorphous content was observed. Between 5 and 15 min milling time the particle size distribution remained relatively constant but the amorphous content increased non-linearly with time. After 20 min milling time the particle size increased slightly. The data suggest that particle size reduction occurs initially upon application of a force to the crystal. Once maximum particle size reduction has occurred the crystal absorbs the force being applied and the crystal lattice becomes disordered. After extended milling the conditions in the ball mill (heat and/or humidity) may cause crystallisation of some of the amorphous material resulting in particle-particle fusion. It would appear that the ball-milling process could be optimised to achieve the desired particle size distribution but without any loss of crystalline structure. PMID:20385222

  3. Isothermal titration calorimetry with micelles: Thermodynamics of inhibitor binding to carnitine palmitoyltransferase 2 membrane protein.

    Science.gov (United States)

    Perspicace, Samantha; Rufer, Arne C; Thoma, Ralf; Mueller, Francis; Hennig, Michael; Ceccarelli, Simona; Schulz-Gasch, Tanja; Seelig, Joachim

    2013-01-01

    Carnitine palmitoyl transferase 2 (CPT-2) is a key enzyme in the mitochondrial fatty acid metabolism. The active site is comprised of a Y-shaped tunnel with distinct binding sites for the substrate acylcarnitine and the cofactor CoA. We investigated the thermodynamics of binding of four inhibitors directed against either the CoA or the acylcarnitine binding sites using isothermal titration calorimetry (ITC). CPT-2 is a monotopic membrane protein and was solubilized by β-octylglucoside (β-OG) above its critical micellar concentration (CMC) to perform inhibitor titrations in solutions containing detergent micelles. The CMC of β-OG in the presence of inhibitors was measured with ITC and small variations were observed. The inhibitors bound to rat CPT-2 (rCPT-2) with 1:1 stoichiometry and the dissociation constants were in the range of K D = 2-20 μM. New X-ray structures and docking models of rCPT-2 in complex with inhibitors enable an analysis of the thermodynamic data in the context of the interaction observed for the individual binding sites of the ligands. For all ligands the binding enthalpy was exothermic, and enthalpy as well as entropy contributed to the binding reaction, with the exception of ST1326 for which binding was solely enthalpy-driven. The substrate analog ST1326 binds to the acylcarnitine binding site and a heat capacity change close to zero suggests a balance of electrostatic and hydrophobic interactions. An excellent correlation of the thermodynamic (ITC) and structural (X-ray crystallography, models) data was observed suggesting that ITC measurements provide valuable information for optimizing inhibitor binding in drug discovery. PMID:23772395

  4. Isothermal titration calorimetry with micelles: Thermodynamics of inhibitor binding to carnitine palmitoyltransferase 2 membrane protein☆

    Science.gov (United States)

    Perspicace, Samantha; Rufer, Arne C.; Thoma, Ralf; Mueller, Francis; Hennig, Michael; Ceccarelli, Simona; Schulz-Gasch, Tanja; Seelig, Joachim

    2013-01-01

    Carnitine palmitoyl transferase 2 (CPT-2) is a key enzyme in the mitochondrial fatty acid metabolism. The active site is comprised of a Y-shaped tunnel with distinct binding sites for the substrate acylcarnitine and the cofactor CoA. We investigated the thermodynamics of binding of four inhibitors directed against either the CoA or the acylcarnitine binding sites using isothermal titration calorimetry (ITC). CPT-2 is a monotopic membrane protein and was solubilized by β-octylglucoside (β-OG) above its critical micellar concentration (CMC) to perform inhibitor titrations in solutions containing detergent micelles. The CMC of β-OG in the presence of inhibitors was measured with ITC and small variations were observed. The inhibitors bound to rat CPT-2 (rCPT-2) with 1:1 stoichiometry and the dissociation constants were in the range of KD = 2–20 μM. New X-ray structures and docking models of rCPT-2 in complex with inhibitors enable an analysis of the thermodynamic data in the context of the interaction observed for the individual binding sites of the ligands. For all ligands the binding enthalpy was exothermic, and enthalpy as well as entropy contributed to the binding reaction, with the exception of ST1326 for which binding was solely enthalpy-driven. The substrate analog ST1326 binds to the acylcarnitine binding site and a heat capacity change close to zero suggests a balance of electrostatic and hydrophobic interactions. An excellent correlation of the thermodynamic (ITC) and structural (X-ray crystallography, models) data was observed suggesting that ITC measurements provide valuable information for optimizing inhibitor binding in drug discovery. PMID:23772395

  5. Strategies for assessing proton linkage to bimolecular interactions by global analysis of isothermal titration calorimetry data

    International Nuclear Information System (INIS)

    Highlights: ► We demonstrate the usefulness of global analysis of ITC data for proton-linked binding study. ► Various experimental strategies are evaluated for their information content. ► Data at multiple temperatures might improve the precision of binding parameters. ► Methods for detailed error analysis of parameter uncertainties are discussed. ► By global modeling, an uncertainty in molecular concentrations can be accounted for. - Abstract: Isothermal titration calorimetry (ITC) is a traditional and powerful method for studying the linkage of ligand binding to proton uptake or release. The theoretical framework has been developed for more than two decades and numerous applications have appeared. In the current work, we explored strategic aspects of experimental design. To this end, we simulated families of ITC data sets that embed different strategies with regard to the number of experiments, range of experimental pH, buffer ionization enthalpy, and temperature. We then re-analyzed the families of data sets in the context of global analysis, employing a proton linkage binding model implemented in the global data analysis platform SEDPHAT, and examined the information content of all data sets by a detailed statistical error analysis of the parameter estimates. In particular, we studied the impact of different assumptions about the knowledge of the exact concentrations of the components, which in practice presents an experimental limitation for many systems. For example, the uncertainty in concentration may reflect imperfectly known extinction coefficients and stock concentrations or may account for different extents of partial inactivation when working with proteins at different pH values. Our results show that the global analysis can yield reliable estimates of the thermodynamic parameters for intrinsic binding and protonation, and that in the context of the global analysis the exact molecular component concentrations may not be required. Additionally

  6. Digital holographic interferometry: A novel optical calorimetry technique for radiation dosimetry

    International Nuclear Information System (INIS)

    Purpose: To develop and demonstrate the proof-of-principle of a novel optical calorimetry method to determine radiation absorbed dose in a transparent medium. Methods: The calorimetric property of water is measured during irradiation by means of an interferometer, which detects temperature-induced changes in the refractive index that can be mathematically related to absorbed dose. The proposed method uses a technique called digital holographic interferometry (DHI), which comprises an optical laser interferometer setup and consecutive physical reconstruction of the recorded wave fronts by means of the Fresnel transform. This paper describes the conceptual framework and provides the mathematical basis for DHI dosimetry. Dose distributions from a high dose rate Brachytherapy source were measured by a prototype optical setup to demonstrate the feasibility of the approach. Results: The developed DHI dosimeter successfully determined absorbed dose distributions in water in the region adjacent to a high dose rate Brachytherapy source. A temperature change of 0.0381 K across a distance of 6.8 mm near the source was measured, corresponding to a dose of 159.3 Gy. The standard deviation in a typical measurement set was ±3.45 Gy (corresponding to an uncertainty in the temperature value of ±8.3 × 10−4 K). The relative dose fall off was in agreement with treatment planning system modeled data. Conclusions: First results with a prototype optical setup and a Brachytherapy source demonstrate the proof-of-principle of the approach. The prototype achieves high spatial resolution of approximately 3 × 10−5 m. The general approach is fundamentally independent of the radiation type and energy. The sensitivity range determined indicates that the method is predominantly suitable for high dose rate applications. Further work is required to determine absolute dose in all three dimensions

  7. A calorimetry system for metabolism trials Sistema de calorimetria para estudos de metabolismo

    Directory of Open Access Journals (Sweden)

    N.M. Rodríguez

    2007-04-01

    Full Text Available An indirect calorimetry system for rapid determination of CO2 and CH4 production and O2 consumption to estimate heat production of animals was built at Escola de Veterinária da Universidade Federal de Minas Gerais, Brazil. Procedures for determination of correction and calibration factors for gas analyzers and the whole system, using standard test gases were described. In addition, a metabolic trial was performed to evaluate heat production of lambs fed ad libitum. It is concluded that the system is suitable for heat production determinations in small and medium size animals.Um sistema de calorimetria para a determinação rápida da produção de CO2 e CH4 e do consumo de O2 de animais para o cálculo da produção de calor foi construído na Escola de Veterinária da Universidade Federal de Minas Gerais. Foram descritos os procedimentos para a determinação dos fatores de correção dos analisadores e calibração do sistema utilizando-se gases padrão. Adicionalmente, um ensaio de metabolismo foi realizado para se avaliar a produção de calor de ovinos alimentados ad libitum. Conclui-se que o sistema está apto para determinações de produção de calor em animais de pequeno e médio porte.

  8. Isobaric specific heat capacity of typical lithium chloride liquid desiccants using scanning calorimetry

    International Nuclear Information System (INIS)

    Highlights: • Typical lithium chloride liquid desiccants were concerned. • Up to date heat capacity data of high quality were measured. • Scanning calorimetry technology was applied. • A universal empirical formula was correlated for the heat capacity of solutions. -- Abstract: Three kinds of lithium chloride desiccants were selected, which are considered to be potential and interesting working fluids for a desiccant/dehumidification or absorption refrigeration system, and their isobaric specific heat capacities were determined in this context. Experiments were conducted at a high accuracy twin-cell scanning calorimeter. The temperature accuracy and heat flux resolution of the calorimeter are ±0.05 K and 0.1 μW respectively. The data of lithium chloride + water and lithium chloride + triethylene glycol (TEG)/propylene glycol (PG) + water systems were achieved at temperatures from 308.15 K to 343.15 K and atmospheric pressure. The mass fraction of LiCl ranged from 15% to 45% in the LiCl + H2O system, and the mass fraction of LiCl and glycol ranged from 10% to 23.3% and 20% to 46.7% in the ternary systems respectively. Based on the experimental heat capacity data, a universal empirical formula was correlated as a function of temperature and solute mass fraction. In the experimental mass fractions and temperatures range, the average absolute deviation (AAD) between experiment results and calculated values is no more than 0.15%, and maximum absolute deviation (MAD) is within 0.38%. These thermodynamic data of lithium chloride solutions can be effectively used for analysis and design of desiccant/dehumidification systems and absorption refrigeration systems in both refrigeration and chemical industry

  9. Using differential scanning calorimetry as an analytical tool for ultrafine-grained metals processed by severe plastic deformation

    OpenAIRE

    Gao, Nong; Starink, Marco J.; Langdon, Terence G.

    2009-01-01

    Differential Scanning Calorimetry (DSC) is a thermal analysis technique that measures the energy absorbed or released by a sample as a function of temperature or time. Analysis by DSC has wide applications for examining solid-state reactions and solid-liquid reactions in many different materials. Quantitative analyses of the kinetics of reactions may be assessed by reviewing the interrelation between activation energy analysis methods. In recent years, DSC has been applied in the examination ...

  10. Structure and Energetics of Encapsidated DNA in Bacteriophage HK97 Studied by Scanning Calorimetry and Cryo-electron Microscopy

    OpenAIRE

    Duda, Robert L.; Ross, Philip D.; Cheng, Naiqian; Firek, Brian A.; Hendrix, Roger W.; Conway, James F; Steven, Alasdair C.

    2009-01-01

    Encapsidation of duplex DNA by bacteriophages represents an extreme case of genome condensation, reaching near-crystalline concentrations of DNA. The HK97 system is well suited to study this phenomenon in view of detailed knowledge of its capsid structure. To characterize the interactions involved, we combined calorimetry with cryo-EM and native gel electrophoresis. We found that, as in other phages, HK97 DNA is organized in coaxially wound nested shells. When scanned in buffer containing 1mM...

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

    OpenAIRE

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

    2001-01-01

    The influence of dimethyl sulfoxide (DMSO) on membrane thickness, multilamellar repeat distance, and phase transitions of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) was investigated by X-ray diffraction and small-angle neutron scattering (SANS). The differential scanning calorimetry (DSC) study of water freezing and ice melting was performed in the ternary DPPC /DMSO /water and binary DMSO /water systems. The methods applied demonstrated the differences in membrane structure in t...

  12. Three phase model in drawn thermoplastic polyesters: Comparison of differential scanning calorimetry and thermally stimulated depolarisation current experiments

    International Nuclear Information System (INIS)

    Differential scanning calorimetry and thermally stimulated depolarisation current measurements are performed to quantify various phases present in amorphous and semi-crystalline polyester samples uniaxially drawn above their respective glass transition temperature. Results show the appearance of a crystalline phase induced by stretching and of a part of the amorphous phase which does not participate in glass transition. The existence of this phase-called rigid amorphous phase-is enhanced by the presence of crystallites rather than by the drawing. (author)

  13. Scan-rate dependence in protein calorimetry: the reversible transitions of Bacillus circulans xylanase and a disulfide-bridge mutant.

    OpenAIRE

    J Davoodi; Wakarchuk, W. W.; Surewicz, W K; Carey, P. R.

    1998-01-01

    The stabilities of Bacillus circulans xylanase and a disulfide-bridge-containing mutant (S100C/N148C) were investigated by differential scanning calorimetry (DSC) and thermal inactivation kinetics. The thermal denaturation of both proteins was found to be irreversible, and the apparent transition temperatures showed a considerable dependence upon scanning rate. In the presence of low (nondenaturing) concentrations of urea, calorimetric transitions were observed for both proteins in the second...

  14. Spin density wave (SDW) transition in Ru doped BaFeAs2 investigated by AC steady state calorimetry

    International Nuclear Information System (INIS)

    Heat capacity measurements were done on sub-micron sized BaFe2−xRuxAs2 single crystals using thin film membrane based the AC steady state calorimetry technique. Noticeable thermal hysteresis is observed in the heat capacity of the BaFe2−xRuxAs2 during cooling and warming cycles, indicating first order nature of the SDW transition

  15. A Statistical Method and Tool to Account for Indirect Calorimetry Differential Measurement Error in a Single-Subject Analysis

    Science.gov (United States)

    Tenan, Matthew S.

    2016-01-01

    Indirect calorimetry and oxygen consumption (VO2) are accepted tools in human physiology research. It has been shown that indirect calorimetry systems exhibit differential measurement error, where the error of a device is systematically different depending on the volume of gas flow. Moreover, systems commonly report multiple decimal places of precision, giving the clinician a false sense of device accuracy. The purpose of this manuscript is to demonstrate the use of a novel statistical tool which models the reliability of two specific indirect calorimetry systems, Douglas bag and Parvomedics 2400 TrueOne, as univariate normal distributions and implements the distribution overlapping coefficient to determine the likelihood that two VO2 measures are the same. A command line implementation of the tool is available for the R programming language as well as a web-based graphical user interface (GUI). This tool is valuable for clinicians performing a single-subject analysis as well as researchers interested in determining if their observed differences exceed the error of the device. PMID:27242546

  16. Thermal properties of [Cr(NH3)6](BF4)3 studied by adiabatic and relaxation calorimetry

    International Nuclear Information System (INIS)

    Highlights: • Four solid phase transitions are observed between T = (9 and 300) K for [Cr(NH3)6](BF4)3. • Low temperature properties were investigated with relaxation calorimetry below T = 20 K. • For nonzero values of applied magnetic field well-defined Schottky anomaly appears. • Isothermal magnetization curve recorded up to 5 T was measured at T = 1.8 K. - Abstract: Four (solid–solid) phase transitions were detected in the temperature range of (9 to 300) K in polycrystalline [Cr(NH3)6](BF4)3 at TC1 = 240.7 K, TC2 = 108.0 K, TC3 = 91.9 K, and TC4 = 61.3 K by adiabatic calorimetry. The measurements by relaxation calorimetry were followed on lowering temperature from 20 K down to 0.35 K under six different external magnetic field values (9, 7, 5, 3, 1 and 0) T. For non-zero values of applied magnetic field well-defined Schottky anomaly appears. Magnetic heat capacity was calculated assuming the zero-field splitting for the decoupled Cr(III) ions. There is no discrepancy between the observed and calculated values. Isothermal magnetization curve recorded up to 5 T was measured at temperature of 1.8 K

  17. A Statistical Method and Tool to Account for Indirect Calorimetry Differential Measurement Error in a Single-Subject Analysis.

    Science.gov (United States)

    Tenan, Matthew S

    2016-01-01

    Indirect calorimetry and oxygen consumption (VO2) are accepted tools in human physiology research. It has been shown that indirect calorimetry systems exhibit differential measurement error, where the error of a device is systematically different depending on the volume of gas flow. Moreover, systems commonly report multiple decimal places of precision, giving the clinician a false sense of device accuracy. The purpose of this manuscript is to demonstrate the use of a novel statistical tool which models the reliability of two specific indirect calorimetry systems, Douglas bag and Parvomedics 2400 TrueOne, as univariate normal distributions and implements the distribution overlapping coefficient to determine the likelihood that two VO2 measures are the same. A command line implementation of the tool is available for the R programming language as well as a web-based graphical user interface (GUI). This tool is valuable for clinicians performing a single-subject analysis as well as researchers interested in determining if their observed differences exceed the error of the device. PMID:27242546

  18. Direct measurement of electron beam quality conversion factors using water calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Renaud, James, E-mail: james.renaud@mail.mcgill.ca; Seuntjens, Jan [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4 (Canada); Sarfehnia, Arman [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3E2 (Canada); Marchant, Kristin [Allan Blair Cancer Centre, Saskatchewan Cancer Agency, Regina, Saskatchewan S4T 7T1, Canada and Department of Oncology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5A1 (Canada); McEwen, Malcolm; Ross, Carl [Ionizing Radiation Standards, National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada)

    2015-11-15

    . General agreement between the relative electron energy dependence of the PTW Roos data measured in this work and a recent MC-based study are also shown. Conclusions: This is the first time that water calorimetry has been successfully used to measure electron beam quality conversion factors for energies as low as 6 MeV (R{sub 50} = 2.25 cm)

  19. Direct measurement of electron beam quality conversion factors using water calorimetry

    International Nuclear Information System (INIS)

    agreement between the relative electron energy dependence of the PTW Roos data measured in this work and a recent MC-based study are also shown. Conclusions: This is the first time that water calorimetry has been successfully used to measure electron beam quality conversion factors for energies as low as 6 MeV (R50 = 2.25 cm)

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

    Directory of Open Access Journals (Sweden)

    Farkas Nelli

    2007-06-01

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

  1. Enhanced thermal property measurement of a silver zinc battery cell using isothermal calorimetry

    International Nuclear Information System (INIS)

    Highlights: • Design and construction of novel heat flow calorimeter for large battery cell. • Heat flow characterization of silver zinc battery under load. • Thermal efficiency determination of silver zinc battery under load. • Surface map of heat flow of silver zinc battery under load. - Abstract: The push for increased energy density of electrochemical cells highlights the need for novel electrochemical techniques as well as additional characterization methods for these cells in order to meet user needs and safety requirements. To achieve ever increasing energy densities and faster controlled release of that energy, all materials of construction must be constantly evaluated from electrode to casing and everything in-between. Increasing the energy density of the cell improves its utility, but it also increases the waste heat and maximum potential uncontrolled energy release. Design agents and system developers need new ways to monitor and classify the probability and severity of the catastrophic failures as well as the system characteristics during intended operation. To support optimization of these battery cells it is necessary to understand their thermal characteristics at rest as well as under prescribed charge and discharge cycles. One of the many calorimetric tools available to observe and record these characteristics is heat flow calorimetry. Typically, a heat flow calorimeter is operated isothermally and measures the sum heat released or consumed by a sample material inside of a calorimetric measuring cell. For this study an improved calorimetric measuring cell for a modified Hart 6209 precision temperature bath was designed and constructed to measure the heat flow of larger electrochemical cells (18 × 8 × 16 cm). This new calorimetric measuring cell is constructed to allow independent measurements of heat flow among each of the sample’s six sides in contrast to the typical one measurement of the average heat flow. Heat flows from 0.01 to 7

  2. Measurements at the RA Reactor related to the VISA-2 project - Part 4, Calorimetry and chemical dosimetry of the new partly filled RA reactor core

    International Nuclear Information System (INIS)

    This report contains the results of values of chemical and calorimetry measurements of absorbed doses in the experimental channels VK-5, VK-9, GF-34 and fuel channels (0706 and 0607) of the Ra reactor. Calorimetry measurements were during reactor operation at 900 kW or 1 MW power, dependent on the type of samples in the calorimeters. For the chemical measurements the power was kept at 500 kW

  3. Thermal Analysis of Whole Bacterial Cells Exposed to Potassium Permanganate Using Differential Scanning Calorimetry: a Biphasic Dose-Dependent Response to Stress

    OpenAIRE

    Marina K. Abuladze; Victor M. Sokhadze; Emma N. Namchevadze; Kiziria, E.; Leila V. Tabatadze; Lejava, Lia V.; Sh. Gogichaishvili; Bakradze, Nugzar B.

    2009-01-01

    Differential scanning calorimetry (DSC) was applied to estimate the impact of the toxic oxidant potassium permanganate (PM) on the intracellular structural and functional alterations at whole cell level using soil bacteria Arthrobacter oxydans as a model culture. Differential scanning calorimetry (DSC) was applied in order to estimate the impact of the toxic oxidant potassium permanganate (PM) on the intracellular structural and functional alterations at the whole cell level using the soil b...

  4. An experimental investigation to evaluate the heating value of palm oil waste by calorimetry. Paper no. IGEC-1-040

    International Nuclear Information System (INIS)

    A palm oil mill produces palm oil and kernel palm oil as main products and biomass residue (fiber and shell). This excess biomass residue can be used as fuel in boilers to meet energy and process heat demand in the industries. Quality of the palm oil waste (POW) is characterized by low fixed carbon and relatively high moisture content which may affect the heating value (HV). By applying the principle of calorimetry, a bomb calorimeter is utilized to evaluate the heating value of POW. From the experimental results, it is found that higher heating value (HHV) varies with the moisture content (MC) and it is observed as a function of MC. (author)

  5. Temperature-modulated calorimetry of the frequency dependence of the glass transition of poly(ethylene terephthalate) and ....

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

    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 asymmetry and cooperativity of the kinetics. Use of a complex description of heat capacity and entropy is discussed. Activation energies vary from 75 to 350 kJ/mol, dependent on thermal pretreatment and the preexponential factor is correlated with the activation energy.

  6. Detection of a new 'nematic-like' phase in liquid crystal-amphiphile mixture by differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Dan, Kaustabh, E-mail: kaustabhdan@gmail.com; Roy, Madhusudan, E-mail: kaustabhdan@gmail.com; Datta, Alokmay, E-mail: kaustabhdan@gmail.com [Surface Physics and Materials Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar Block, Sector 1, Kolkata-700064 (India)

    2014-04-24

    Differential Scanning Calorimetry (DSC) studies on phase transitions of the pure liquid crystalline material N-4-methoxybenzylidene-4-butylaniline (MBBA) and mixtures of MBBA and the amphiphile Stearic Acid (StA) show significant changes in the behavior of mixture from pure MBBA, as regards the nematic-isotropic (N-I) transition temperature (T{sub c}) and other thermodynamic parameters like enthalpy, specific heat and activation energy with concentration of StA. In particular, the convexity of the Arrhenius plot in pure MBBA vanishes with StA concentration pointing to the formation of a new, perhaps 'nematic-like', phase in the mixtures.

  7. Using low temperature calorimetry and moisture fixation method to study the pore structure of cement based materials

    OpenAIRE

    Wu, Min; Johannesson, Björn; Geiker, Mette Rica

    2014-01-01

    Porestrukturen er en af de vigtigste karakteristika ved cement baserede materialer. Dette PhD studium har fokuseret på brugen af lav (mikro-)temperatur calorimetri (LTC) og en fugt fikserings metode til bestemmelse af porestrukturen i cement baserede materialer, specielt på nano-skala. Der er specielt lagt vægt på undersøgelser af faktorer, som har indflydelse på analysen af målte data og brugen af LTC til at karakterisere porestrukturen i cement baserede materialer. Fugt fikserings metoden b...

  8. Thermal characterization of Li/sulfur, Li/ S-LiFePO4 and Li/S-LiV3O8 cells using Isothermal Micro-Calorimetry and Accelerating Rate Calorimetry

    Science.gov (United States)

    Seo, Jeongwook; Sankarasubramanian, Shrihari; Kim, Chi-Su; Hovington, Pierre; Prakash, Jai; Zaghib, Karim

    2015-09-01

    The thermal behavior of three cathode materials for the lithium/sulfur (Li/S) cell, namely - sulfur, sulfur-LiFePO4 (S-LFP) composite and sulfur-LiV3O8 (S-LVO) composite was studied using Isothermal Micro-Calorimetry (IMC) at various discharge rates. A continuum model was used to calculate the reversible entropic heat and irreversible resistive heat generated over the discharge process and the model data was compared to the experimental data to elucidate contributions of reversible and irreversible heats to the overall heat generated during discharge. The reaction enthalpy (ΔHRx) was measured using IMC for each elementary reaction step and in combination with the calculated reversible entropic heat and irreversible resistive heat was fitted against the experimental total heat measurement. The model showed an excellent fit against the experimental data. Further, Accelerating Rate Calorimetry (ARC) was used to study the thermal safety of these three cells. The cell with the S-LVO composite cathode was found to have the highest onset temperature for thermal runaway and also the lowest maximum self-heat rate. Results of this study suggest that S-LVO composite is a promising electrode for Li/S cells.

  9. Evaluation of aluminosilicate glass sintering during differential scanning calorimetry; Estudo da sinterizacao de vidros aluminossilicatos por calorimetria exploratoria diferencial

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Juliana Pereira de

    2015-07-01

    In this work a difference in the baseline in differential scanning calorimetry analyses, observed in a work where aluminosilicate glasses microspheres containing Ho were studied for application in selective internal radiotherapy as hepatocellular carcinoma treatment, was studied. The glasses with nominal composition 53,7 SiO{sub 2} .10,5 Al{sub 2}O{sub 3} . 35,8 MgO in %mol were produced from traditional melting. The first obtained were milled and sieved in the range of 45 a 63 μm. The material was used to produce glass microspheres by the gravitational fall method. The glass powder and the microspheres were characterized by X ray fluorescence spectrometry, laser diffraction, X ray diffraction, differential scanning calorimetry, differential thermal analysis, thermogravimetry, mass spectrometry, and scanning electron microscopy. After the thermal analyses, pellets were formed in the crucibles and were analyzed by scanning electron microscopy, X ray diffraction, and He pycnometry. The difference in the baseline was associated to the viscous flow sintering process and happens because of the decrease in the detected heat flow due to the sample shrinkage. Other events as concurrent crystallization with the sintering process were also studied. (author)

  10. Experimental determination of the nucleation rates of undercooled micron-sized liquid droplets based on fast chip calorimetry

    International Nuclear Information System (INIS)

    Highlights: • Fast scanning calorimeter calibration with position dependence. • Calibration of fast scanning calorimeter during cooling. • Quantitative determination of nucleation rates by treating the undercooling as stochastic parameter - Abstract: Accurate thermal analyzes and calorimetry measurements depend on careful calibration measurements. For conventional differential scanning calorimeters (DSC) the calibration procedure is well known. The melting point of different pure metals is measured and compared with literature data to adjust the temperature reading of the calorimeter. Likewise, the measured melting enthalpies of standard reference substances serve for enthalpy calibration. Yet for fast chip calorimetry, new procedures need to be established. For the medium-area and large-area calorimeter chips, this procedure needs to be modified, because the calibration behavior depends on the position of the sample on the measurement area. Additionally, a way to calibrate the calorimeter for measurements performed during cooling will also be shown. For this second aspect, the athermal and diffusionless martensitic phase transformation of Ni49.9–Ti50.1 at% was used. The well-calibrated sensor chips are ideally suited to perform nucleation rate density analyzes based on a statistical approach. Here, the nucleation rate densities of micron-sized pure Sn droplets that had been coated with a non-catalytic coating have been determined by experimental analysis of the statistical variance of the undercooling response

  11. Change in physical structure of a phenol-spiked sapric histosol observed by Differential Scanning Calorimetry

    Science.gov (United States)

    Ondruch, Pavel; Kucerik, Jiri; Schaumann, Gabriele E.

    2014-05-01

    Interactions of pollutants with soil organic matter (SOM), their fate and transformation are crucial for understanding of soil functions and properties. In past, many papers dealing with sorption of organic and inorganic compounds have been published. However, their aim was almost exceptionally fo-cused on the pollutants themselves, determination of sorption isotherms and influence of external factors, while the change in SOM supramolecular structure was usually ignored. The SOM structure is, however, very important, since the adsorbed pollutant might have a significant influence on soil stability and functions. Differential scanning calorimetry (DSC) represents a technique, which has been successfully used to analyze the physical structure and physico-chemical aging of SOM. It has been found out that water molecules progressively stabilize SOM (water molecule bridge (WaMB)) (Schaumann & Bertmer 2008). Those bridges connect and stabilize SOM and can be disrupted at higher temperature (WaMB transition; (Kunhi Mouvenchery et al. 2013; Schaumann et al. 2013). In the same temperature region melting of aliphatic moieties can be observed (Hu et al. 2000; Chilom & Rice 2005; Kucerik et al. submitted 2013). In this work, we studied the effect of phenol on the physical structure of sapric histosol. Phenol was dissolved in various solvents (water, acetone, hexane, methanol) and added to soils. After the evaporation of solvents by air drying, the sample was equilibrated at 76% relative humidity for 3 weeks. Using DSC, we investigated the influence of phenol on histosol structure and time dependence of melting temperature of aliphatic moieties and WaMB transition. While addition of pure organic solvent only resulted in slightly increased transition temperatures, both melting temperature and WaMB transition temperature were significantly reduced in most cases if phenol was dissolved in these solvents. Water treatment caused a decrease in WaMB transition temperature but

  12. Interactions in interesterified palm and palm kernel oils mixtures. II – Microscopy and Differential Scanning Calorimetry

    Directory of Open Access Journals (Sweden)

    Grimaldi, Renato

    2001-12-01

    Full Text Available Palm oil (PO and palm kernel oil (PKO compositions (100/0, 80/20, 60/40, 50/50, 40/60, 20/80 and 0/100 were interesterified in laboratory scale under predetermined conditions (0.4% sodium metoxide, 20 minutes, 100ºC. The fourteen samples, before and after interesterification, were characterized by Polarized Light Microscopy and Differential Scanning Calorimetry (DSC. Results showed the effect of various factors on the form and width of crystals. The mean area of crystals revealed the increase of crystals when PKO was added, with values varying from 2.7 x 10E3 µm2 to PO and 1.8 x 10E6 µm2 to PKO. After interesterification, the crystal widths were lower at PO/PKO 100/0, 80/20, 60/40, 20/80 fractions and were higher to anothers. The beta-prime polimorphic form was observed in the pure palm oil sample. The results showed in melting curves, onset values from –19.6ºC to more unsaturated peaks until 20.7ºC to more saturated ones. The higher values to more saturated peak in a melting curve to palm oil, 38.7 J.g-1 before and 48.4 J.g-1 after interesterification, showed a mores table saturated group. I n a genera l way, t h e interesterification promoted an increase of crystallization rate and a better compatibility between PO/PKO fractions.Fueron interesterificados en el laboratorio mezclas de aceite de palma (PO y aceite de palmiste (PKO en diferentes proporciones (100/0, 80/20, 60/40, 50/50, 40/60, 20/80 y 0/100 bajo condiciones predeterminadas (0.4% metoxido de sodio, 20 minutos, 100ºC. Las catorce muestras fueron caracterizadas antes y después de la interesterificación por Microscopía de Luz Polarizada y por Calorimetría Diferencial de Barrido (DSC. Los resultados mostraron el efecto de varios factores sobre la forma y anchura de los cristales. El área media de los cristales revela el aumento de tamaño de los mismos cuando aumenta la proporción de PKO, con valores que varían entre 2.7 x 10E3 µm2 para PO y 1.8 x 10E

  13. Evidence analysis library review of best practices for performing indirect calorimetry in healthy and non-critically ill individuals.

    Science.gov (United States)

    Fullmer, Susan; Benson-Davies, Sue; Earthman, Carrie P; Frankenfield, David C; Gradwell, Erica; Lee, Peggy S P; Piemonte, Tami; Trabulsi, Jillian

    2015-09-01

    When measurement of resting metabolic rate (RMR) by indirect calorimetry is necessary, following evidence-based protocols will ensure the individual has achieved a resting state. The purpose of this project was to update the best practices for measuring RMR by indirect calorimetry in healthy and non-critically ill adults and children found the Evidence Analysis Library of the Academy of Nutrition and Dietetics. The Evidence Analysis process described by the Academy of Nutrition and Dietetics was followed. The Ovid database was searched for papers published between 2003 and 2012 using key words identified by the work group and research consultants, studies used in the previous project were also considered (1980 to 2003), and references were hand searched. The work group worked in pairs to assign papers to specific questions; however, the work group developed evidence summaries, conclusion statements, and recommendations as a group. Only 43 papers were included to answer 21 questions about the best practices to ensure an individual is at rest when measuring RMR in the non-critically ill population. In summary, subjects should be fasted for at least 7 hours and rest for 30 minutes in a thermoneutral, quiet, and dimly lit room in the supine position before the test, without doing any activities, including fidgeting, reading, or listening to music. RMR can be measured at any time of the day as long as resting conditions are met. The duration of the effects of nicotine and caffeine and other stimulants is unknown, but lasts longer than 140 minutes and 240 minutes, respectively. The duration of the effects of various types of exercise on RMR is unknown. Recommendations for achieving steady state, preferred gas-collection devices, and use of respiratory quotient to detect measurement errors are also given. Of the 21 conclusions statements developed in this systemic review, only 5 received a grade I or II. One limitation is the low number of studies available to address the

  14. Isothermal calorimetry study of calcium caseinate and whey protein isolate edible films cross-linked by heating and gamma-irradiation.

    Science.gov (United States)

    Letendre, M; D'Aprano, G; Delmas-Patterson, G; Lacroix, M

    2002-10-01

    The contribution of thermal and radiative treatments as well as the presence of some excipients, namely glycerol, carboxymethylcellulose (CMC), pectin, and agar, on the formation of protein-protein interactions as well as the formation and loss of protein-water interactions was investigated by means of differential scanning calorimetry in an isothermal mode. Protein-water interactions were assessed through measurement of the heat of the wetting parameter. Isothermal calorimetry measurements pointed out that gamma-irradiation does not favor protein-water interactions, as reflected by its endothermic contribution (P thermal treatment on endothermic responses using isothermal calorimetry was found to be somewhat lower. Among excipients added to biofilm formulations, glycerol generated the most important losses of protein-water interactions, as inferred by its significant (P < or = 0.05) endothermic impact on the heat of wetting values. PMID:12358479

  15. Thermophysical properties of solid phase ruthenium measured by the pulse calorimetry technique over a wide temperature range

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, Nenad; Nikolic, Ivana [Belgrade Univ. (Serbia). Vinca Institute of Nuclear Sciences

    2015-04-15

    This paper presents experimental results on four thermophysical properties of pure polycrystalline ruthenium samples over a wide temperature range. Specific heat capacity and specific electrical resistivity were measured from 250 to 2 500 K, while hemispherical total emissivity and normal spectral emissivity at 900 nm were measured from 1 300 to 2 500 K. All the properties were obtained by using the pulse calorimetry technique. The 200 mm long specimens were in the form of a thin rod, of about 3 mm in diameter. For necessary corrections, literature data on thermal linear expansion were applied. The results are compared with available literature data and discussed. The specific heat capacity and specific electrical resistivity measurements did not indicate any allotropic transformation of the samples over the entire temperature range.

  16. DIFFERENTIAL SCANNING CALORIMETRY AND X-RAY DIFFRACTION STUDIES ON AGING BEHAVIOR OF Zn-Al ALLOYS

    Institute of Scientific and Technical Information of China (English)

    X.L. Xu; Z.W. Yu; S.J. Ji; J.C. Sun; Z.K. Hei

    2001-01-01

    Decomposition processes of the quenched Zn-Al alloys were studied by differentiai scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the stabilities of supersaturated solid solution (SSS) of Zn-Al alloy and c' phase formed by quenching would reduce with increasing Zn content and precipitating η-Zn phases even when aging at ambient temperature,so that exothermic precipitation peak in DSC curve would disappear. The activation energy of the η-Zn precipitation and their reaction enthalpy were calculated and measured. The kinetics of α' decomposition or η-Zn formation was determined by XRD.The microstructure change during aging was observed by TEM.

  17. R & D proposal for the study of new fast and radiation hard scintillators for calorimetry at LHC

    CERN Document Server

    Hervé, A; Le Goff, J M; Allegretti, F; Pizzini, S; Borgia, B; Ferroni, F; Longo, E; Mattioli, M; De Notaristefani, F; Moine, B; Pédrini, C; Lebeau, M; Schneegans, M; Vivargent, M; Samsonov, V; Schegelsky, V A; Yanovski, V V; Jönsson, L B; Lübelsmeyer, K; Schmitz, D; Wallraff, W; Aziz, T; Banerjee, S; Ganguli, S N; Sen-Gupta, S K; Gurtu, A; Malhotra, P K; Mazumdar, K; Raghavan, R; Shankar, K; Sudhakar, K; Tonwar, S C; CERN. Geneva. Detector Research and Development Committee

    1991-01-01

    In the recent past several scintillating crystals have been developed and mass produced for large, high resolution electromagnetic calorimeters, such as NaI, CsI and BGO. In the new generation of ee and pp colliders the very high design luminosities bring new constraints on the crystals: they must have a fast response, higher resistance to radiation, and be as dense as possible for calorimeter compactness. From our systematic studies of scintillation properties and radiation damage mechanisms in scintillators, several fluoride crystals or glasses should have the wanted properties. The purpose of this R&D programme is to study these materials and the conditions of their mass production in order to find the scintillator best suited for calorimetry at future colliders.

  18. High-Pressure Raman and Calorimetry Studies of Vanadium(III) Alkyl Hydrides for Kubas-Type Hydrogen Storage.

    Science.gov (United States)

    Morris, Leah; Trudeau, Michel L; Reed, Daniel; Book, David; Antonelli, David M

    2016-03-16

    Reversible hydrogen storage under ambient conditions has been identified as a major bottleneck in enabling a future hydrogen economy. Herein, we report an amorphous vanadium(III) alkyl hydride gel that binds hydrogen through the Kubas interaction. The material possesses a gravimetric adsorption capacity of 5.42 wt % H2 at 120 bar and 298 K reversibly at saturation with no loss of capacity after ten cycles. This corresponds to a volumetric capacity of 75.4 kgH2  m(-3) . Raman experiments at 100 bar confirm that Kubas binding is involved in the adsorption mechanism. The material possesses an enthalpy of H2 adsorption of +0.52 kJ mol(-1) H2 , as measured directly by calorimetry, and this is practical for use in a vehicles without a complex heat management system. PMID:26762590

  19. Limitations of amorphous content quantification by isothermal calorimetry using saturated salt solutions to control relative humidity: alternative methods.

    Science.gov (United States)

    Khalef, Nawel; Pinal, Rodolfo; Bakri, Aziz

    2010-04-01

    Despite the high sensitivity of isothermal calorimetry (IC), reported measurements of amorphous content by this technique show significant variability even for the same compound. An investigation into the reasons behind such variability is presented using amorphous lactose and salbutamol sulfate as model compounds. An analysis was carried out on the heat evolved as a result of the exchange of water vapor between the solid sample during crystallization and the saline solution reservoir. The use of saturated salt solutions as means of control of the vapor pressure of water within sealed ampoules bears inherent limitations that lead in turn to the variability associated with the IC technique. We present an alternative IC method, based on an open cell configuration that effectively addresses the limitations encountered with the sealed ampoule system. The proposed approach yields an integral whose value is proportional to the amorphous content in the sample, thus enabling reliable and consistent quantifications. PMID:19774655

  20. Investigation of lipid membrane macro- and micro-structure using calorimetry and computer simulation: structural and functional relationships

    DEFF Research Database (Denmark)

    Jørgensen, Kent; Mouritsen, Ole G.

    The lipid bilayer part of biological membranes is a complex lipid mixture displaying cooperative phenomena. By means of differential scanning calorimetry and computer simulation techniques, the equilibrium and non-equilibrium properties of the large assembly of mutually interacting amphiphilic...... lead to the formation of a heterogeneous lateral bilayer structure composed of dynamic lipid domains and differentiated bilayer regions. In addition, the non-equilibrium dynamic ordering process of coexisting phases can give rise to the formation of local lipid structures on various length- and time......-scales. The results suggest that the structural and dynamical lipid bilayer behavior and in particular the appearance of small-scale lipid structures might be of importance for membrane functionality, e.g., membrane compartmentalization, trails-membrane permeability, and the activity of membrane...

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

    International Nuclear Information System (INIS)

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

  2. Interaction of Ru(Ⅱ) Complex with Yeast tRNA Studied by Isothermal Titration Calorimetry

    Institute of Scientific and Technical Information of China (English)

    徐宏; 刘敛洪; 刘志刚; 梁毅; 张鹏; 杜芬; 周兵瑞; 计亮年

    2005-01-01

    The interaction of metal complex with RNA has been studied by isothermal titration calorimetry (ITC) for the first time. ITC experiments show that complex [Ru(phen)2MPIP]2+ {phen= 1,10-phenanthroline, MP[P-2-(4-methylphenyl)imidazo[4,5-f]-1, 10-phenanthroline} interacts with yeast tRNA in terms of a model for a singleset of identical sites through intercalation, which is consistent with our previous observation obtained from spectroscopic methods, and this binding process was driven by a moderately favorable enthalpy decrease in combination with a moderately favorable entropy increase, suggesting that ITC is an effective method for deep studying the interactions of metal complexes with RNA.

  3. The use of isothermal titration calorimetry to determine the thermodynamics of metal ion binding to low-cost sorbents

    International Nuclear Information System (INIS)

    The thermodynamics of Al3+, Cr3+, and Pb2+ binding to the abundant biopolymer chitin have been determined using isothermal titration calorimetry (ITC) and compared to what is observed for binding to activated carbon. The use of ITC enables the detection of two distinct binding sites on chitin for all three metal ions. For the relative strong binding sites, free energy changes ranges from -37.6 kJ/mol to -41.8 kJ/mol while the same values are from -30.1 kJ/mol to -31.8 kJ/mol for the relative weak binding sites. All binding reactions to chitin are entropically driven. Interactions of the metal ions to activated carbon are best fitted as a single-site binding with relative weak binding with free energy changes from -26.3 kJ/mol to -26.8 kJ/mol.

  4. Characterization of phase change materials for thermal control of photovoltaics using Differential Scanning Calorimetry and Temperature History Method

    International Nuclear Information System (INIS)

    Highlights: • Five PCM are characterized using tow techniques for PV temperature regulation. • Thermophysical properties of interest are determined and compared with literature. • Determined PCM properties are discussed as criteria for PV temperature regulation. • One PCM identified as potential candidate for PV temperature regulation. - Abstract: Five solid–liquid phase change materials comprising three basic classes, paraffin waxes, salt hydrates and mixtures of fatty acids were thermophysically characterized for thermal regulation applications in photovoltaics. The PCM were investigated using Differential Scanning Calorimetry and Temperature History Method to find their thermophysical properties of interest. The relationship between thermophysical properties of the PCM and their choice as temperature regulators in photovoltaics is discussed in relation to the ambient conditions under which PV systems operate

  5. Particle Size (Sieving) and Enthalpy (Acid Calorimetry) Analysis of Single-Pull K East Basin Floor and Pit Sludges

    International Nuclear Information System (INIS)

    This report presents the results of particle size analyses and calorimetry testing performed on selected single-pull sludge samples collected from the Hanford K East Basin between December 1998 and June 1999. The samples were collected as isolated cores predominantly from areas that had not been previously sampled (e.g., North Loadout Pit, Dummy Elevator Pit, Tech View Pit), or from areas in which the sludge composition had been altered since the last sampling (e.g., Weasel Pit). Particle size analyses were performed by washing wet sludge samples through a series of four sieves with openings of 250, 500, 1410, and 4000 microm. The loaded sieves were weighed before and after drying to obtain wet and dry particle size distributions. Knowledge of the particle size distribution is needed to design and predict the performance of the systems that will be used to retrieve, transport, and recover sludge. Also, sieving provides an opportunity to observe the components in the sludge. For example, during sieving of the sludge sample from the North Loadout Pit, significant quantities of organic ion exchange beads were observed. The uranium metal content and the particle size of the uranium metal in the K Basin sludge will largely determine the chemical reactivity of the sludge. In turn, the designs for the sludge handling and storage systems must be compatible with the reactivity of the sludge. Therefore, acid calorimetry was performed to estimate the uranium metal content of the sludge. For this testing, sludge samples were dissolved in nitric acid within a calibrated adiabatic calorimeter. The resulting dissolution enthalpy data were then used to discriminate between metallic uranium (minus3750 J/g in nitric acid) and uranium oxide (minus394 J/g in nitric acid). Results from this testing showed that the single-pull sludge samples contained little or no uranium metal

  6. Combined use of titration calorimetry and spectrofluorimetry for the screening of the acidity of solid catalysts in different liquids

    Energy Technology Data Exchange (ETDEWEB)

    Gervasini, Antonella, E-mail: antonella.gervasini@unimi.it [Dipartimento di Chimica, Università degli Studi di Milano, via Camillo Golgi, 19, 20133 Milano (Italy); Auroux, Aline, E-mail: aline.auroux@ircelyon.univ-lyon1.fr [Université Lyon 1, CNRS, UMR 5256, Institut de Recherches sur la Catalyse et l‘Environnement de Lyon (IRCELYON), 2 Avenue A. Einstein, 69626 Villeurbanne (France)

    2013-09-10

    Graphical abstract: Measurements of acidity of oxides of catalytic importance in various liquids open the possibility to know their effective acidity, which is related with their activity in liquid-heterogeneous catalysis. Titration-calorimetry alone or in connection with spectrofluorimetry is efficient for this scope. - Highlights: • Measurements of acidity of oxides of catalytic importance in various liquids. • Titration-calorimetry alone or in connection with spectrofluorimetry is efficient for this scope. • Effective acidities are expressed by given sample in various liquids. • Nb-containing samples are able to maintain acidity in protic liquids. - Abstract: The effective acid and base surface properties of selected acidic and basic samples of catalytic interest (alumina, titania, zirconia, silica–alumina, niobium oxide, niobium phosphate, boron nitride, and hydrotalcite) were measured by titration with basic and acidic molecular probes (aniline, 2-phenylethylamine, and phenol) in various liquids (cyclohexane, 1,4-dioxane, isopropanol, n-decane, and toluene) with different polar and protic characteristics. The combined use of a reaction calorimeter and a spectrofluorimeter has been performed. The set-up of the coupled technique and the most interesting results are shown here. The study confirmed that the acid–base properties of solids are deeply affected by the nature and properties of the liquid surrounding the samples. Few oxides are able to maintain their surface acidity in highly polar and protic solvents, in particular whose containing niobium. In general, the solvating and coordinative ability of the most polar and protic liquids caused remarkable loss of acidity/basicity of the oxide surfaces.

  7. Particle Size (Sieving) and Enthalpy (Acid Calorimetry) Analysis of Single-Pull K East Basin Floor and Pit Sludges

    Energy Technology Data Exchange (ETDEWEB)

    PR Bredt; CH Delegard; AJ Schmidt; KL Silvers; BM Thornton; S Gano

    2000-12-22

    This report presents the results of particle size analyses and calorimetry testing performed on selected single-pull sludge samples collected from the Hanford K East Basin between December 1998 and June 1999. The samples were collected as isolated cores predominantly from areas that had not been previously sampled (e.g., North Loadout Pit, Dummy Elevator Pit, Tech View Pit), or from areas in which the sludge composition had been altered since the last sampling (e.g., Weasel Pit). Particle size analyses were performed by washing wet sludge samples through a series of four sieves with openings of 250, 500, 1410, and 4000 {micro}m. The loaded sieves were weighed before and after drying to obtain wet and dry particle size distributions. Knowledge of the particle size distribution is needed to design and predict the performance of the systems that will be used to retrieve, transport, and recover sludge. Also, sieving provides an opportunity to observe the components in the sludge. For example, during sieving of the sludge sample from the North Loadout Pit, significant quantities of organic ion exchange beads were observed. The uranium metal content and the particle size of the uranium metal in the K Basin sludge will largely determine the chemical reactivity of the sludge. In turn, the designs for the sludge handling and storage systems must be compatible with the reactivity of the sludge. Therefore, acid calorimetry was performed to estimate the uranium metal content of the sludge. For this testing, sludge samples were dissolved in nitric acid within a calibrated adiabatic calorimeter. The resulting dissolution enthalpy data were then used to discriminate between metallic uranium ({minus}3750 J/g in nitric acid) and uranium oxide ({minus}394 J/g in nitric acid). Results from this testing showed that the single-pull sludge samples contained little or no uranium metal.

  8. Development of a water calorimetry-based standard for absorbed dose to water in HDR 192Ir brachytherapy

    International Nuclear Information System (INIS)

    Purpose: The aim of this article is to develop and evaluate a primary standard for HDR 192Ir brachytherapy based on 4 deg. C stagnant water calorimetry. Methods: The absolute absorbed dose to water was directly measured for several different Nucletron microSelectron 192Ir sources of air kerma strength ranging between 21 000 and 38 000 U and for source-to-detector separations ranging between 25 and 70 mm. The COMSOL MULTIPHYSICS software was used to accurately calculate the heat transport in a detailed model geometry. Through a coupling of the ''conduction and convection'' module with the ''Navier-Stokes incompressible fluid'' module in the software, both the conductive and convective effects were modeled. Results: A detailed uncertainty analysis resulted in an overall uncertainty in the absorbed dose of 1.90%(1σ). However, this includes a 1.5% uncertainty associated with a nonlinear predrift correction which can be substantially reduced if sufficient time is provided for the system to come to a new equilibrium in between successive calorimetric runs, an opportunity not available to the authors in their clinical setting due to time constraints on the machine. An average normalized dose rate of 361±7 μGy/(h U) at a source-to-detector separation of 55 mm was measured for the microSelectron 192Ir source based on water calorimetry. The measured absorbed dose per air kerma strength agreed to better than 0.8%(1σ) with independent ionization chamber and EBT-1 Gafchromic film reference dosimetry as well as with the currently accepted AAPM TG-43 protocol measurements. Conclusions: This work paves the way toward a primary absorbed dose to water standard in 192Ir brachytherapy.

  9. Stereo-selectivity of human serum albumin to enantiomeric and isoelectronic pollutants dissected by spectroscopy, calorimetry and bioinformatics.

    Directory of Open Access Journals (Sweden)

    Ejaz Ahmad

    Full Text Available 1-naphthol (1N, 2-naphthol (2N and 8-quinolinol (8H are general water pollutants. 1N and 2N are the configurational enantiomers and 8H is isoelectronic to 1N and 2N. These pollutants when ingested are transported in the blood by proteins like human serum albumin (HSA. Binding of these pollutants to HSA has been explored to elucidate the specific selectivity of molecular recognition by this multiligand binding protein. The association constants (K(b of these pollutants to HSA were moderate (10(4-10(5 M(-1. The proximity of the ligands to HSA is also revealed by their average binding distance, r, which is estimated to be in the range of 4.39-5.37 nm. The binding free energy (ΔG in each case remains effectively the same for each site because of enthalpy-entropy compensation (EEC. The difference observed between ΔC(p (exp and ΔC(p (calc are suggested to be caused by binding-induced flexibility changes in the HSA. Efforts are also made to elaborate the differences observed in binding isotherms obtained through multiple approaches of calorimetry, spectroscopy and bioinformatics. We suggest that difference in dissociation constants of pollutants by calorimetry, spectroscopic and computational approaches could correspond to occurrence of different set of populations of pollutants having different molecular characteristics in ground state and excited state. Furthermore, our observation of enhanced binding of pollutants (2N and 8H in the presence of hemin signifies that ligands like hemin may enhance the storage period of these pollutants in blood that may even facilitate the ill effects of these pollutants.

  10. Nucleation behavior of melted Bi films at cooling rates from 101 to 104 K/s studied by combining scanning AC and DC nano-calorimetry techniques

    International Nuclear Information System (INIS)

    Highlights: • We proposed a general data reduction scheme that combines scanning AC and DC calorimetry results for the study of reaction kinetics. • Calorimetry measurements at cooling rates ranging from 30 K/s to 20,000 K/s were achieved. • Upon initial melting, the Bi thin-film sample breaks up into thousands of isolated islands, and highly repeatable nucleation behavior is observed. • The nucleation rate of melted Bi is calculated, which can be well described by classical nucleation theory over a wide range of cooling rates. - Abstract: We study the nucleation behavior of undercooled liquid Bi at cooling rates ranging from 101 to 104 K/s using a combination of scanning DC and AC nano-calorimetry techniques. Upon initial melting, the Bi thin-film sample breaks up into silicon nitride-coated isolated islands. The number of islands in a typical sample is sufficiently large that highly repeatable nucleation behavior is observed, despite the stochastic nature of the nucleation process. We establish a data reduction technique to evaluate the nucleation rate from DC and AC calorimetry results. The results show that the driving force for the nucleation of melted Bi is well described by classical nucleation theory over a wide range of cooling rates. The proposed technique provides a unique and efficient way to examine nucleation kinetics with cooling rates over several orders of magnitude. The technique is quite general and can be used to evaluate reaction kinetics in other materials

  11. Optimization of the scintillation parameters of the lead tungstate crystals for their application in high precision electromagnetic calorimetry; Optimisation des parametres de scintillation des cristaux de tungstate de plomb pour leur application dans la calorimetrie electromagnetique de haute precision

    Energy Technology Data Exchange (ETDEWEB)

    Drobychev, G

    2000-04-12

    In the frame of this dissertation work scintillation properties of the lead tungstate crystals (PWO) and possibilities of their use were studied foreseeing their application for electromagnetic calorimetry in extreme radiation environment conditions of new colliders. The results of this work can be summarized in the following way. 1. A model of the scintillations origin in the lead tungstate crystals which includes processes influencing on the crystals radiation hardness and presence of slow components in scintillations was developed. 2. An analysis of the influences of the PWO scintillation properties changes on the parameters of the electromagnetic calorimeter was done. 3. Methods of the light collection from the large scintillation elements of complex shape made of the birefringent scintillation crystal with high refraction index and low light yield in case of signal registration by a photodetector with sensitive surface small in compare with the output face of scintillator were Studied. 4. Physical principles of the methodology of the scintillation crystals certification during their mass production foreseeing their installation into a calorimeter electromagnetic were developed. Correlations between the results of measurements of the PWO crystals parameters by different methods were found. (author)

  12. Cationic gemini and sodium cholate – Following the interaction of oppositely charged surfactants by calorimetry, turbidity and conductivity

    International Nuclear Information System (INIS)

    Highlights: • ITC and conductivity provide critical concentrations for these complex systems. • OD helps the understanding of their structural changes. • ITC provides the enthalpies accompanying the various processes in the mixed systems. • The cmcmix are smaller than cmc for pure surfactants indicating a synergistic effect. • The gemini spacer length influences its aggregation behavior with NaCA. - Abstract: The thermodynamics of the process of self-assembly of cationic gemini surfactants, [C12H25(CH3)2N(CH2)SN(CH3)2C12H25]Br2, (the spacer S being 2, 6 or 10, assigned as C12CSC12Br2) and the system of oppositely charged mixture of surfactants formed by C12CSC12Br2 and sodium cholate (NaCA) in aqueous solution has been investigated by isothermal titration calorimetry (ITC), conductivity and turbidity measurements. The critical micelle concentration values (cmc) for the gemini surfactants C12CSC12Br2 obtained from calorimetry and conductivity were found to be consistent with values reported in the literature. The enthalpies of micellization (ΔHmic) of C12CSC12Br2 are all exothermic, presenting a strong negative minimum at S = 6, corresponding to the maximum in the cmc values. For the mixed system of oppositely charged surfactants (C12CSC12Br2(S = 2, 6, 10)/NaCA), we did obtain from ITC the critical parameters for different events that take place as the concentration of gemini surfactant increases, such as the formation of NaCA-rich mixed micelles (cmcmix, ΔHmic-mix), the formation of a precipitate (immiscible liquid crystalline (LC) phase) (CP, ΔHP) and its re-dissolution (CR, ΔHR), and finally the formation of positive charge-rich mixed micelles (CM, ΔHM). It should be stressed that the values of cmcmix (gemini) are much smaller than those for pure gemini and pure NaCA. These results also show that there is a stronger synergistic effect between the two surfactants in the NaCA-rich region. The turbidity measurements proved valuable to the

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

    International Nuclear Information System (INIS)

    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 (SANS). The DSC study of water freezing and melting of ice was performed in the ternary system which consists of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC)/DMSO/water system. The influence of DMSO on the DPPC membrane structure was established in the excess of solvent in the region of DMSO mole fraction from 0.0 to 1.0. The methods applied demonstrated the differences in the membrane structure in three sub-regions of DMSO mole fraction (XDMSO) from 0.0 to 0.3 for the first, from 0.3 to 0.9 for the second, and from 0.9 to 1.0 for the third sub-region. The results for 0.0 ≤ XDMSO ≤ 0.3 can be explained in the framework of DMSO-induced dehydration of intermembrane space

  14. Study of phase transformations of Fe-Cr-C system using the technique of differential scanning calorimetry

    International Nuclear Information System (INIS)

    The family of 9% Cr-1% Mo steels has been considered by The Generation IV International Forum as candidate materials for the construction of these prospective advanced nuclear reactors. A simple system related with these steels is the Fe-Cr-C system. In this work, a laboratory made Fe-10% Cr-0,1% C alloy has been studied. Particularly, the effect of the cooling rate on the transformations that take place when the alloy is cooled from the austenitic field was analyzed. To perform this analysis two techniques have been used: The differential scanning calorimetry (DSC) and the scanning electron microscopy (SEM). Different cooling rates of 4, 10, 50 and 90 °C/min were tested in the DSC and the resulting microstructures were observed by SEM. At the rates of 50 and 90 °C/min the cooling treatment produced a martensitic structure. Contrarily, cooling at a rate of 4 °C/min produced a microstructure consisting mainly of ferrite-pearlite with a low fraction of martensite. In the heating step which followed the cooling step, the magnetic transformation is well resolved as a broad peak which presents a maximum at 753 ± 1 °C for all the cooling rates. (author)

  15. Comments on the interpretation of differential scanning calorimetry results for thermoelastic martensitic transformations: Athermal versus thermally activated kinetics

    International Nuclear Information System (INIS)

    In a previous article Van Humbeeck and Planes have made a number of criticisms of the authors' recent paper concerning the interpretation of the results obtained by Differential Scanning Calorimetry (DSC) from the Martensitic Transformation of Cu-Al-Ni-Mn-B alloys. Although the martensitic transformation of these shape memory alloys is generally classified as athermal, it has been confirmed that the capacity of the alloys to undergo a more complete thermoelastic transformation (i.e. better reversibility of the transformation) increased with the Mn content. This behavior has been explained by interpreting the DSC results obtained during thermal cycling in terms of a thermally activated mechanism controlling the direct and reverse transformations. When the heating rate increases during the reverse transformation the DSC curves shift towards higher temperatures while they shift towards the lower temperatures when the cooling rate was increased during the direct transformation. Since the starting transformation temperatures (As, Ms) do not shift, Van Humbeeck and Planes state that there is no real peak shift and assume that the DCS experiments were carried out without taking into account the thermal lag effect between sample and cell. On the following line they deduce a time constant, τ, of 60 seconds because the peak maximum shifts. In fact the assumption made by Van Humbeeck and Planes is false

  16. Characterization of a Friction Stir Weld in Aluminum Alloy 7055 Using Microhardness, Electrical Conductivity, and Differential Scanning Calorimetry (DSC)

    Science.gov (United States)

    Bush, Ralph; Kiyota, Michelle; Kiyota, Catherine

    2016-04-01

    Optical microscopy, microhardness, electrical conductivity, and differential scanning calorimetry (DSC) were used to characterize the microstructure, hardness, and precipitate structure as a function of position in a friction stir weld, naturally aged for 10 years, in aluminum alloy 7055. Results are shown for the as-welded/naturally aged condition and for a weld that was post-aged using a -T76 regimen. The grain structure and microhardness results reveal the expected central recrystallized region, a thermo-mechanical affected zone (TMAZ), and heat-affected zone (HAZ) with typical changes in microhardness. DSC scans for the as-welded/naturally aged condition indicate a precipitate structure similar to that of a naturally aged condition in the central recrystallized region. Maximum precipitate coarsening and overaging occurs near the TMAZ/HAZ boundary with reduced precipitate dissolution and coarsening as the distance from the weld increases. The post-weld aging resulted in the transformation of GP zones to more stable precipitates plus coarsening of the more stable η' and η precipitates. A combination of DSC testing and CALPHAD calculations allowed calculation of precipitate volume fraction in the HAZ. The precipitate volume fraction decreased monotonically from 0.052 in the baseline material to 0.044 at the TMAZ/HAZ interface.

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

    CERN Document Server

    Kiselev, M A; Kisselev, A M; Grabielle-Madelmond, C; Ollivon, M

    1999-01-01

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

  18. Synergistic antioxidation of organic molybdenum complex with dithiocarbamate antioxidant evaluated by differential scanning calorimetry and thin film micro oxidation test

    International Nuclear Information System (INIS)

    An oil-soluble sulfur- and phosphorus-free organic molybdenum complex (MC) was synthesized. The antioxidation properties of MC- and methylene bis(di-n-butyldithiocarbamate) (V 7723)-containing poly-α-olefin (PAO)-derived lubricants were evaluated by differential scanning calorimetry (DSC) and modified penn state micro-oxidation test (PMOT). DSC test measures incipient oxidation temperature (OT) and oxidation induction time (IT) of the lubricant at high temperatures and the oxidation stability of oil weight loss is measured by PMOT test. DSC test shows that OT and IT of V 7723-containing PAO were improved significantly by MC addition. PMOT test indicates that when combining with V 7723 antioxidants, MC can also effectively reduce the increase in weight loss of PAO. These results suggest that the MC shows a good oxidative synergism with V 7723 antioxidant. In addition, FTIR results from PMOT test confirm that addition of MC can significantly enhance the oxidation induction time of oils and inhibit formation of oxidation products containing carbonyl bonds or hydroxyl group. The proposed mechanism of the inhibition involves a synergy between MC and V 7723

  19. Optimization of the scintillation parameters of the lead tungstate crystals for their application in high precision electromagnetic calorimetry

    International Nuclear Information System (INIS)

    In the frame of this dissertation work scintillation properties of the lead tungstate crystals PWO) and possibilities of their use were studied foreseeing their application for electromagnetic calorimetry in extreme radiation environment conditions of new colliders. The results of this work can be summarized in the following way. 1. A model of the scintillations origin in the lead tungstate crystals which includes processes influencing on the crystals radiation hardness and presence of slow components in scintillations was developed. 2. An analysis of the influences of the PWO scintillation properties changes on the parameters of the electromagnetic calorimeter was done. 3. Methods of the light collection from the large scintillation elements of complex shape made of the birefringent scintillation crystal with high refraction index and low light yield in case of signal registration by a photodetector with sensitive surface small in compare with the output face of scintillator were Studied. 4. Physical principles of the methodology of the scintillation crystals certification during their mass production foreseeing their installation into a calorimeter electromagnetic were developed. Correlations between the results of measurements of the PWO crystals parameters by different methods were found. (author)

  20. Weak interactions in clobazam–lactose mixtures examined by differential scanning calorimetry: Comparison with the captopril–lactose system

    International Nuclear Information System (INIS)

    Highlights: ► Thermodynamic and kinetic parameters of weak interactions in binary systems by DSC. ► Energy-barrier decrease for lactose dehydration induced by clobazam. ► Recrystallisation of metastable liquid clobazam induced by anhydrous alpha lactose. ► Decrease of lactose dehydration temperature in binary mixtures with captopril. ► Increase of lactose dehydration enthalpy in binary mixtures with captopril. - Abstract: The thermal behaviour of binary mixtures of two drugs (clobazam and captopril, respectively) and a pharmaceutical excipient (lactose monohydrate) was measured with differential scanning calorimetry to determine thermodynamic and kinetic parameters (dehydration and melting enthalpies and dehydration and glass-transition activation energies) which might be affected by intermolecular interactions. A kinetic study showed that lactose dehydration is not a single-step conversion and that clobazam contributed to reduce the energy barrier for the bulk dehydration of the excipient. On the other hand, the physical interactions between metastable liquid clobazam and crystalline anhydrous α-lactose obtained from monohydrate dehydration gave rise to the recrystallisation of clobazam. In the captopril–lactose system, the liquid captopril influenced the lactose dehydration: a sharp increase of the dehydration enthalpy and a concurrent reduction of the dehydration temperature were observed. Finally, it turned out that solid-phase transitions were enhanced by the contact with a liquid phase.

  1. Weak interactions in clobazam-lactose mixtures examined by differential scanning calorimetry: Comparison with the captopril-lactose system

    Energy Technology Data Exchange (ETDEWEB)

    Toscani, S. [Departement de Chimie - UMR 6226, Faculte des Sciences, Universite de Rennes 1, Batiment 10B, 263 avenue du General Leclerc, F-35042 Rennes Cedex (France); Cornevin, L. [Universite de Rennes 1, Faculte de Pharmacie, 2 Avenue Leon Bernard, F-35043 Rennes Cedex (France); Burgot, G., E-mail: Gwenola.burgot@univ-rennes1.fr [Universite de Rennes 1, Faculte de Pharmacie, Laboratoire de Chimie Analytique, EA 1274 ' Mouvement, sports, sante' , 2 Avenue Leon Bernard, F-35043 Rennes Cedex (France); CHGR Rennes, Pole Medico-Technique Pharmacie, F-35703 Rennes Cedex (France)

    2012-09-10

    Highlights: Black-Right-Pointing-Pointer Thermodynamic and kinetic parameters of weak interactions in binary systems by DSC. Black-Right-Pointing-Pointer Energy-barrier decrease for lactose dehydration induced by clobazam. Black-Right-Pointing-Pointer Recrystallisation of metastable liquid clobazam induced by anhydrous alpha lactose. Black-Right-Pointing-Pointer Decrease of lactose dehydration temperature in binary mixtures with captopril. Black-Right-Pointing-Pointer Increase of lactose dehydration enthalpy in binary mixtures with captopril. - Abstract: The thermal behaviour of binary mixtures of two drugs (clobazam and captopril, respectively) and a pharmaceutical excipient (lactose monohydrate) was measured with differential scanning calorimetry to determine thermodynamic and kinetic parameters (dehydration and melting enthalpies and dehydration and glass-transition activation energies) which might be affected by intermolecular interactions. A kinetic study showed that lactose dehydration is not a single-step conversion and that clobazam contributed to reduce the energy barrier for the bulk dehydration of the excipient. On the other hand, the physical interactions between metastable liquid clobazam and crystalline anhydrous {alpha}-lactose obtained from monohydrate dehydration gave rise to the recrystallisation of clobazam. In the captopril-lactose system, the liquid captopril influenced the lactose dehydration: a sharp increase of the dehydration enthalpy and a concurrent reduction of the dehydration temperature were observed. Finally, it turned out that solid-phase transitions were enhanced by the contact with a liquid phase.

  2. Fractional and component analysis of crude oils by the method of dynamic microdistillation. Differential scanning calorimetry coupled with thermogravimetry

    Energy Technology Data Exchange (ETDEWEB)

    Shishkin, Yu.L. [Gubkin Russian State University of Oil and Gas, Leninsky Prospect 65, 119991 Moscow (Russian Federation)

    2006-02-15

    High-resolution differential scanning calorimetry was used to accurately establish the temperature intervals of oxidation/distillation of the major components of crude oils. Some theoretical aspects of the method of dynamic microdistillation, enabling consecutive distillation (oxidation) of the main components of hydrocarbon mixtures, are discussed. The experimental TG-DSC curves show that the temperature scan of the run can be divided into six regions, of which the first belongs to simple distillation of the sample's liquid constituent (the distillate) and the others to oxidative cracking distillation of the solid (heavy) residue. The latter occur in the order paraffins+light oils, middle base oils, heavy base oils, condensed aromatics (resins) and asphaltenes. The probable oxidation mechanisms of different classes of petroleum hydrocarbons operating in different temperature regions are discussed. Full quantitative fractional and group component analysis of a number of crude oils of different chemical classes and geological age was carried out by the combined TG-DSC techniques under specially chosen experimental conditions (those of dynamic microdistillation). (author)

  3. Effect of polyglycerol esters additive on palm oil crystallization using focused beam reflectance measurement and differential scanning calorimetry.

    Science.gov (United States)

    Saw, M H; Hishamuddin, E; Chong, C L; Yeoh, C B; Lim, W H

    2017-01-01

    The effect of 0.1-0.7% (w/w) of polyglycerol esters (PGEmix-8) on palm oil crystallization was studied using focused beam reflectance measurement (FBRM) to analyze the in-line changes of crystal size distribution during the crystallization. FBRM results show that 0.1-0.5% (w/w) of PGEmix-8 did not significantly affect nucleation but slightly retarded crystal growth. The use of 0.7% (w/w) additive showed greater heterogeneous nucleation compared to those with lower dosages of additive. Crystal growth was also greatly reduced when using 0.7% (w/w) dosage. The morphological study indicated that the palm oil crystals were smaller and more even in size than when more additive was added. Isothermal crystallization studies using differential scanning calorimetry (DSC) showed increased inhibitory effects on palm oil crystal growth with increasing concentration of PGEmix-8. These results imply that PGEmix-8 is a nucleation enhancing and crystal growth retarding additive in palm oil crystallization at 0.7% (w/w) dosage. PMID:27507476

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

    Energy Technology Data Exchange (ETDEWEB)

    Stavrou, E; Tsiantos, C; Tsopouridou, R D; Kripotou, S; Kontos, A G; Raptis, C [Department of Physics, National Technical University of Athens, GR-15780 Athens (Greece); Capoen, B; Bouazaoui, M [Laboratoire de Physique des Lasers, Atomes et Molecules (CNRS, UMR 8523), Batiment P-5, Centre d' Etudes et de Recherches Lasers et Applications (CERLA-FR CNRS 2416), Universite de Sciences et Technologies de Lille, F-59655 Villeneuve d' Ascq Cedex (France); Turrell, S; Khatir, S, E-mail: craptis@central.ntua.g [Laboratoire de Spectrochimie Infrarouge et Raman (CNRS 8516), Batiment C-5, Centre d' Etudes et de Recherches Lasers et Applications (CERLA-FR CNRS 2416), Universite de Sciences et Technologies de Lille, F-59655 Villeneuve d' Ascq Cedex (France)

    2010-05-19

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

  5. Thermal and structural behavior of dioctadecyldimethylammonium bromide dispersions studied by differential scanning calorimetry and X-ray scattering.

    Directory of Open Access Journals (Sweden)

    Eloi Feitosa

    Full Text Available Dioctadecyldimethylammonium bromide (DODAB is a double chain cationic lipid, which assembles as bilayer structures in aqueous solution. The precise structures formed depend on, e.g., lipid concentration and temperature. We here combine differential scanning calorimetry (DSC and X-ray scattering (SAXS and WAXS to investigate the thermal and structural behavior of up to 120 mM DODAB in water within the temperature range 1-70 °C. Below 1 mM, this system is dominated by unilamellar vesicles (ULVs. Between 1 and 65 mM, ULVs and multilamellar structures (MLSs co-exist, while above 65 mM, the MLSs are the preferred structure. Depending on temperature, DSC and X-ray data show that the vesicles can be either in the subgel (SG, gel, or liquid crystalline (LC state, while the MLSs (with lattice distance d = 36.7 Å consist of interdigitated lamellae in the SG state, and ULVs in the LC state (no Bragg peak. Critical temperatures related to the thermal transitions of these bilayer structures obtained in the heating and cooling modes are reported, together with the corresponding transition enthalpies.

  6. Langmuir monolayers and Differential Scanning Calorimetry for the study of the interactions between camptothecin drugs and biomembrane models.

    Science.gov (United States)

    Casadó, Ana; Giuffrida, M Chiara; Sagristá, M Lluïsa; Castelli, Francesco; Pujol, Montserrat; Alsina, M Asunción; Mora, Margarita

    2016-02-01

    CPT-11 and SN-38 are camptothecins with strong antitumor activity. Nevertheless, their severe side effects and the chemical instability of their lactone ring have questioned the usual forms for its administration and have focused the current research on the development of new suitable pharmaceutical formulations. This work presents a biophysical study of the interfacial interactions of CPT-11 and SN-38 with membrane mimetic models by using monolayer techniques and Differential Scanning Calorimetry. The aim is to get new insights for the understanding of the bilayer mechanics after drug incorporation and to optimize the design of drug delivery systems based on the formation of stable bilayer structures. Moreover, from our knowledge, the molecular interactions between camptothecins and phospholipids have not been investigated in detail, despite their importance in the context of drug action. The results show that neither CPT-11 nor SN-38 disturbs the structure of the complex liposome bilayers, despite their different solubility, that CPT-11, positively charged in its piperidine group, interacts electrostatically with DOPS, making stable the incorporation of a high percentage of CPT-11 into liposomes and that SN-38 establishes weak repulsive interactions with lipid molecules that modify the compressibility of the bilayer without affecting significantly neither the lipid collapse pressure nor the miscibility pattern of drug-lipid mixed monolayers. The suitability of a binary and a ternary lipid mixture for encapsulating SN-38 and CPT-11, respectively, has been demonstrated. PMID:26656185

  7. Differential scanning calorimetry studies of Se85Te15-xPbx (x 4,6,8 and 10) glasses

    International Nuclear Information System (INIS)

    Results of differential scanning calorimetry (DSC) studies of Se85Te15-xPbx (x = 4, 6, 8 and 10) glasses have been reported and discussed in this paper. The results have been analyzed on the basis of structural relaxation equation, Matusita's equation and modified Kissinger's equation. The activation energies of structural relaxation lie in between 226 and 593 kJ/mol. The crystallization growth is found to be one-dimensional for all compositions. The activation energies of crystallization are found to be 100-136 kJ/mol by Matusita's equation while 102-139 kJ/mol by modified Kissinger's equation. The Hruby number (indicator of ease of glass forming and higher stability) is the highest for Se85Te9Pb6 glass while S factor (indicator of resistance to devitrification) is highest for Se85Te7Pb8 glass at all heating rates in our experiment. Further the highest resistance to devitrification has the highest value of structural activation energy and the activation energy of crystallization is maximum for the most stable glass by both Matusita's equation and the modified Kissinger's equation. (author)

  8. Study of the crystallization kinetics of LAS glass by differential scanning calorimetry, X-ray diffraction, and beam bending viscometry

    International Nuclear Information System (INIS)

    Highlights: ► The crystallization of LAS glass was investigated using XRD, DSC and beam bending viscometry. ► Different models were used to determine the kinetic parameters for crystallization. ► The activation energy and Avrami parameters obtained are consistent with reported values. ► The crystallization of LAS glass occurs with three-dimensional crystals growth. - Abstract: The crystallization kinetics of a commercial lithium-aluminum silicate (LAS) glass were characterized by differential scanning calorimetry (DSC) under non-isothermal conditions, by in-situ X-ray diffraction, and by three point beam bending viscosimeter (BBV). Non-isothermal DSC experiments were conducted at different heating rates. Results show that the crystal growth is controlled by a thermally activated process of the Arrhenius type. The activation energies obtained from isoconversional analysis are close to that extracted using the Johnson–Mehl–Avrami equation. While X-ray diffraction volume fraction data confirm the DSC analysis, it also shows that the crystallite size changes only at the end of the heat treatment protocol, during a hold at temperatures as high as 1000 °C. In this latter case, the crystal growth follows the Ostwald ripening mechanism. Finally, the viscosity measured in the crystallization region by BBV provides the activation energy for viscous flow, and it is slightly higher than the values obtained by DSC.

  9. Phase Transitions of Binary Lipid Mixtures: A Combined Study by Adiabatic Scanning Calorimetry and Quartz Crystal Microbalance with Dissipation Monitoring

    Directory of Open Access Journals (Sweden)

    P. Losada-Pérez

    2015-01-01

    Full Text Available The phase transitions of binary lipid mixtures are studied by a combination of Peltier-element-based adiabatic scanning calorimetry (pASC and quartz crystal microbalance with dissipation monitoring (QCM-D. pASC, a novel type of calorimeter, provides valuable and unambiguous information on the heat capacity and the enthalpy, whereas QCM-D is proposed as a genuine way of determining phase diagrams by analysing the temperature dependence of the viscosity. Two binary mixtures of phospholipids with the same polar head and differing in the alkyl chain length, DMPC + DPPC and DMPC + DSPC, are discussed. Both techniques give consistent phase diagrams, which compare well with literature results, showing their capability to map the phase behaviour of pure lipids as well as lipid mixtures. This work can be considered as a departure point for further investigations on more complex lipid mixtures displaying relevant phases such as the liquid-ordered phase and solid-lipid interfaces with biologically functional importance.

  10. Transformation relaxation and aging in a CuZnAl shape-memory alloy studied by modulated differential scanning calorimetry

    Science.gov (United States)

    Wei, Z. G.

    1998-11-01

    The reverse martensitic transformation and aging processes in a polycrystalline Cu-23.52 at. pct Zn-9.65 at. pct Al shape-memory alloy have been studied using the recently developed modulated differential scanning calorimetry (MDSC) technique, and some new findings are obtained. By separating the nonreversing heat flow from the reversing heat flow, MDSC can better characterize the thermodynamic, kinetic, and hysteretic features of thermoelastic martensitic transformations. Two kinds of exothermal relaxation peaks have been identified and separated from the endothermal reverse martensitic transformation: one is associated with the movement of twin interfaces or martensite-parent interfaces, and another is due to the atomic reordering in the parent phase via a vacancy mechanism. The martensite aging processes have been examined, and two stages of the aging process been distinguished: the first stage of aging is characterized by the stabilization of martensite, as manifested in the increase in the reversing enthalpy of the reverse martensitic transformation and in the transformation temperatures, and the second stage is, in fact, the decomposition of the martensite on prolonged aging, accompanied by a decrease in the transformation enthalpy. The results suggest that the mechanisms of the relaxation in the martensite and in the parent phase may be quite different.

  11. Assessing Mixing Quality of a Copovidone-TPGS Hot Melt Extrusion Process with Atomic Force Microscopy and Differential Scanning Calorimetry.

    Science.gov (United States)

    Lamm, Matthew S; DiNunzio, James; Khawaja, Nazia N; Crocker, Louis S; Pecora, Anthony

    2016-02-01

    Atomic force microscopy (AFM) and modulated differential scanning calorimetry (mDSC) were used to evaluate the extent of mixing of a hot melt extrusion process for producing solid dispersions of copovidone and D-α-tocopherol polyethylene glycol 1000 succinate (TPGS 1000). In addition to composition, extrusion process parameters of screw speed and thermal quench rate were varied. The data indicated that for 10% TPGS and 300 rpm screw speed, the mixing was insufficient to yield a single-phase amorphous material. AFM images of the extrudate cross section for air-cooled material indicate round domains 200 to 700 nm in diameter without any observed alignment resulting from the extrusion whereas domains in extrudate subjected to chilled rolls were elliptical in shape with uniform orientation. Thermal analysis indicated that the domains were predominantly semi-crystalline TPGS. For 10% TPGS and 600 rpm screw speed, AFM and mDSC data were consistent with that of a single-phase amorphous material for both thermal quench rates examined. When the TPGS concentration was reduced to 5%, a single-phase amorphous material was achieved for all conditions even the slowest screw speed studied (150 rpm). PMID:26283196

  12. Transformation relaxation and aging in a CuZnAl shape-memory alloy studied by modulated differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Z.G. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Materials Science and Engineering

    1998-11-01

    The reverse martensitic transformation and aging processes in a polycrystalline Cu-23.52 at. pct Zn-9.65 at. pct Al shape-memory alloy have been studied using the recently developed modulated differential scanning calorimetry (MDSC) technique, and some new findings are obtained. By separating the nonreversing heat flow from the reversing heat flow, MDSC can better characterize the thermodynamic, kinetic, and hysteretic feature of thermoelastic martensitic transformations. Two kinds of exothermal relaxation peaks have been identified and separated from the endothermal reverse martensitic transformations: one is associated with the movement of twin interfaces or martensite-parent interfaces, and another is due to the atomic reordering in the parent phase via a vacancy mechanism. The martensite aging processes have been examined, and two stages of the aging process has been distinguished: the first stage of aging is characterized by the stabilization of martensite, as manifested in the increase in the reversing enthalpy of the reverse martensitic transformation and in the transformation temperatures, and the second stage, is in fact, the decomposition of the martensite on prolonged aging, accompanied by a decrease in the transformation enthalpy. The results suggest that the mechanisms of the relaxation in the martensite and in the parent phase may be quite different.

  13. Differential scanning calorimetry studies of Se85Te15–Pb ( = 4, 6, 8 and 10) glasses

    Indian Academy of Sciences (India)

    N B Maharajan; N S Saxena; Deepika Bhandari; Mousa M Imran; D D Paudyal

    2000-10-01

    Results of differential scanning calorimetry (DSC) studies of Se85Te15–Pb ( = 4, 6, 8 and 10) glasses have been reported and discussed in this paper. The results have been analyzed on the basis of structural relaxation equation, Matusita’s equation and modified Kissinger’s equation. The activation energies of structural relaxation lie in between 226 and 593 kJ/mol. The crystallization growth is found to be onedimensional for all compositions. The activation energies of crystallization are found to be 100–136 kJ/mol by Matusita’s equation while 102–139 kJ/mol by modified Kissinger’s equation. The Hruby number (indicator of ease of glass forming and higher stability) is the highest for Se85Te9Pb6 glass while S factor (indicator of resistance to devitrification) is highest for Se85Te7Pb8 glass at all heating rates in our experiment. Further the highest resistance to devitrification has the highest value of structural activation energy and the activation energy of crystallization is maximum for the most stable glass by both Matusita’s equation and the modified Kissinger’s equation.

  14. Characterization of a Friction Stir Weld in Aluminum Alloy 7055 Using Microhardness, Electrical Conductivity, and Differential Scanning Calorimetry (DSC)

    Science.gov (United States)

    Bush, Ralph; Kiyota, Michelle; Kiyota, Catherine

    2016-07-01

    Optical microscopy, microhardness, electrical conductivity, and differential scanning calorimetry (DSC) were used to characterize the microstructure, hardness, and precipitate structure as a function of position in a friction stir weld, naturally aged for 10 years, in aluminum alloy 7055. Results are shown for the as-welded/naturally aged condition and for a weld that was post-aged using a -T76 regimen. The grain structure and microhardness results reveal the expected central recrystallized region, a thermo-mechanical affected zone (TMAZ), and heat-affected zone (HAZ) with typical changes in microhardness. DSC scans for the as-welded/naturally aged condition indicate a precipitate structure similar to that of a naturally aged condition in the central recrystallized region. Maximum precipitate coarsening and overaging occurs near the TMAZ/HAZ boundary with reduced precipitate dissolution and coarsening as the distance from the weld increases. The post-weld aging resulted in the transformation of GP zones to more stable precipitates plus coarsening of the more stable η' and η precipitates. A combination of DSC testing and CALPHAD calculations allowed calculation of precipitate volume fraction in the HAZ. The precipitate volume fraction decreased monotonically from 0.052 in the baseline material to 0.044 at the TMAZ/HAZ interface.

  15. Study on the characterization and thermal decomposition of uranium compounds by thermogravimetry (TG) and differential scanning calorimetry (DSC)

    International Nuclear Information System (INIS)

    A contribution to the characterization of several uranium compounds obtained at the IPEN' Uranium Pilot Plant is given. Particularly, samples of ammonium diuranate (ADU) and uranium oxides were studied. The main objective was to know the stoichiometry of the ADU and the oxides resulting from its thermal transformation. ADU samples were prepared by batchwise precipitation, stationary dewatering into stove and batchwise thermal decomposition, or, alternatively, continuous precipitation, continuous filtration, continuous drying and continuous thermal decomposition inside a temperature gradient electrical furnace. All ADU were precipitated using NH3 gas from uranul sulfate or uranyl nitrate solutions. The thermal decomposition of ADU and uranium oxides were studied in an air atmosphere by thermogravimetry (TG) and differential scanning calorimetry (DSC). Any correlation between the parameters of precipitation, drying, calcination and the hystory of the obtaintion of the several uraniumm compounds and their initial and final composition was looked for. Heating program was established to have the U3O8 oxide as the final product. Intermediary phases were tentatively identified. Temperatures at which occurred the absorption water elimination, crystallization water elimination, evolution or oxidation of NH3, decomposition of NO-3 ion and oxygen evolution and the exo- and endothermic process for each sample were identified. (Author)

  16. Activation Enthalpies of Deformation-Induced Lattice Defects in Severe Plastic Deformation Nanometals Measured by Differential Scanning Calorimetry

    Science.gov (United States)

    Setman, Daria; Kerber, Michael B.; Schafler, Erhard; Zehetbauer, Michael J.

    2010-04-01

    Samples of 99.99 pct pure copper and nickel of 99.998 pct purity were deformed by high-pressure torsion (HPT) at different hydrostatic pressures, to different shear strains. Activation enthalpies ( Q) were determined by differential scanning calorimetry (DSC) using Kissinger’s method. For the one annealing peak found in HPT Cu, Q amounts to Q = 0.78 to 0.48 eV depending on the shear strain applied. In the case of Ni, the activation enthalpies of the two annealing peaks were determined as Q = 0.65 eV and Q = 0.95 eV, respectively, with no obvious dependence on shear strain, although this has been indicated by the annealing peak temperatures. Applying defect specific analyses of the annealing peaks, it turned out that the larger Q value represents the annihilation of dislocations and agglomerates, while the smaller one reflects the annihilation of single or double vacancies. Concerning the strain dependence of the larger Q, two possible explanations have been discussed: (1) the annihilation of dislocations assisted by the strain-dependent density of vacancy agglomerates and (2) the annihilation of dislocations enhanced by a strain-dependent level of long-range internal stresses. Because of closer correlations of Q with external and internal stresses at very high shear strains, explanation (2) has been favored.

  17. Status report on an engineering design study of hermetic liquid argon calorimetry for the SSC [Superconducting Super Collider

    International Nuclear Information System (INIS)

    There is general recognition that engineering issues are critical to the viability of liquid argon calorimetry (LAC) at the Superconducting Super Collider (SSC). We have undertaken to quantitatively address these issues and, if possible, perform a preliminary design of a ''proof of principle'' LAC for SSC. To establish LAC as viable at SSC, we must demonstrate that the physics performance of the device is acceptable, despite the presence of dead material due to vessels and support structure. Our approach involves the construction, by a team of physicists and engineers, of one three dimensional model of the LAC system, built as a hierarchy of components and structures, from which we directly perform interferences checks, mechanical, thermal and magnetic analyses, particle tracking, hermeticity evaluation, physics simulation and assembly. This study, begun in February 1989 as part of the SSC generic detector R and D program, was immediately preceded by a workshop at which engineering details of existing and planned LAC systems were thoroughly examined. We describe below the status of our work, beginning with short descriptions of the tools used, the study requirements and LAC configuration baseline. We then detail the LAC design as it presently stands, including assembly considerations, and conclude with a quantitative assessment of the LAC hermeticity. 19 refs., 12 figs

  18. Theoretical Aspects of Differential Scanning Calorimetry as a Tool for the Studies of Equilibrium Thermodynamics in Pharmaceutical Solid Phase Transitions.

    Science.gov (United States)

    Faroongsarng, Damrongsak

    2016-06-01

    Although differential scanning calorimetry (DSC) is a non-equilibrium technique, it has been used to gain energetic information that involves phase equilibria. DSC has been widely used to characterize the equilibrium melting parameters of small organic pharmaceutical compounds. An understanding of how DSC measures an equilibrium event could make for a better interpretation of the results. The aim of this mini-review was to provide a theoretical insight into the DSC measurement to obtain the equilibrium thermodynamics of a phase transition especially the melting process. It was demonstrated that the heat quantity obtained from the DSC thermogram (ΔH) was related to the thermodynamic enthalpy of the phase transition (ΔH (P) ) via: ΔH = ΔH (P) /(1 + K (- 1)) where K was the equilibrium constant. In melting, the solid and liquefied phases presumably coexist resulting in a null Gibbs free energy that produces an infinitely larger K. Thus, ΔH could be interpreted as ΔH (P). Issues of DSC investigations on melting behavior of crystalline solids including polymorphism, degradation impurity due to heating in situ, and eutectic melting were discussed. In addition, DSC has been a tool for determination of the impurity based on an ideal solution of the melt that is one of the official methods used to establish the reference standard. PMID:27091667

  19. Standard enthalpies of formation of some carbides, silicides, germanides and borides of holmium by high temperature direct synthesis calorimetry

    International Nuclear Information System (INIS)

    The standard enthalpies of formation for some holmium alloys in the binary systems Ho-X (where X=C, Si, Ge, B) have been determined by direct synthesis calorimetry at 1473±2 K. The following values of ΔHof(298 K) kJ (mol of atoms)-1 are reported: HoC2=-28.6±1.2; HoSi=-80.9±2.2; HoSi2=-57.8±2.4; Ho5Si3=-74.6±2.1; Ho5≥3=-91.8±1.7; HoB2=-27.9±1.5. The results are compared with some earlier experimental values derived from mass spectrometric measurements, with available calorimetric data for the corresponding compounds of some of the early lanthanide elements, and with predicted values from the semi-empirical model of Miedema and co-workers. We also test the possible correlation between the enthalpies of formation and the relative molar volumes of the compounds as suggested by Gschneidner. (orig.)

  20. Comparison of doubly labeled water, intake-balance, and direct- and indirect-calorimetry methods for measuring energy expenditure in adult men

    International Nuclear Information System (INIS)

    Energy expenditure (EE) of four adult men on a weight-maintenance diet was estimated by use of doubly labeled water, intake balance, and direct and indirect calorimetry. The doubly labeled water (2H218O) method was used to estimate free-living EE for 13 d. Metabolizable energy (ME) intake was used to estimate free-living EE for 1 wk. The subjects' 24-h EE was measured in a dual direct-indirect room calorimeter on 3 alternate days. Estimates of free-living EE as measured by ME intake and doubly labeled water indicate agreement between the two methods (mean difference +/- SEM, -1.04 +/- 0.63%). Measurements of EE with indirect and direct calorimetry are equivalent (mean difference 0.63 +/- 0.44%). The daily EE measured by doubly labeled water in these free-living adults over a 13-d period was 15.01% greater than the 24-h EE measured within the calorimeter

  1. Adiabatic calorimetry test of the reaction kinetics and self-heating model for 18650 Li-ion cells in various states of charge

    Science.gov (United States)

    Chen, Wei-Chun; Wang, Yih-Wen; Shu, Chi-Min

    2016-06-01

    Use of adiabatic calorimetry to characterise thermal runaway of Li-ion cells is a crucial technique in battery safety testing. Various states of charge (SoC) of Li-ion cells were investigated to ascertain their thermal runaway features using a Vent Sizing Package 2 (VSP2) adiabatic calorimeter. To evaluate the thermal runaway characteristics, the temperature-pressure-time trajectories of commercial cylindrical cells were tested, and it was found that cells at a SoC of greater than 50% were subject to thermal explosion at elevated temperatures. Calorimetry data from various 18650 Li-ion cells with different SoC were used to calculate the thermal explosion energies and chemical kinetics; furthermore, a novel self-heating model based on a pseudo-zero-order reaction that follows the Arrhenius equation was found to be applicable for studying the exothermic reaction of a charged cell.

  2. Fiber optic calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Rudy, C.; Bayliss, S.; Bracken, D. [Los Alamos National Lab., NM (United States); Bush, J.; Davis, P. [Optiphase, Inc., Van Nuys, CA (United States)

    1998-01-01

    A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using fiber for heat-flow measurements of special nuclear material. This calorimeter uses piezoelectric-generated phase-carrier modulation with subsequent electronic signal processing to allow phase shifts as small as 1 microradian ({mu}rad) to be measured. The sensing element consists of 21-m lengths of single-mode optical fiber wrapped around sample and reference chambers. The sensitivity of the calorimeter was determined to be 74 radians (rad) of phase shift per milliwatt of thermal power. One milliwatt of thermal power is equivalent to 400 mg of plutonium (6% {sup 240}Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium.

  3. Fiber optic calorimetry

    International Nuclear Information System (INIS)

    A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using optical fibers for heat-flow measurements of special nuclear material. This calorimeter uses piezoelectric-generated phase-carrier modulation with subsequent electronic signal processing to allow phase shifts as small as 1 microrad to be measured. The sensing element consists of 21-m lengths of single-mode optical fiber wrapped around sample and reference chambers. The sensitivity of the calorimeter was determined to be 74 rad of phase shift per mW of thermal power. One milliwatt of thermal power is equivalent to 400 mg of plutonium (6% 240Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium

  4. Fiber Optic Calorimetry

    International Nuclear Information System (INIS)

    A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using optical fibers for heat-flow measurements of special nuclear material. This calorimeter uses piezoelectric-generated phase-carrier modulation with subsequent electronic signal processes to allow phase shifts as small as 1 microradian (microrad) to be measured. The sensing element consists of 21-m lengths of single-mode optical fiber wrapped around sample and reference chambers. The sensitivity of the calorimeter was determined to be 74 radians (rad) of phase shift per milliwatt of thermal power. One milliwatt of thermal power is equivalent to 400 mg of plutonium (6% 240Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium

  5. Fiber optic calorimetry

    International Nuclear Information System (INIS)

    A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using fiber for heat-flow measurements of special nuclear material. This calorimeter uses piezoelectric-generated phase-carrier modulation with subsequent electronic signal processing to allow phase shifts as small as 1 microradian (μrad) to be measured. The sensing element consists of 21-m lengths of single-mode optical fiber wrapped around sample and reference chambers. The sensitivity of the calorimeter was determined to be 74 radians (rad) of phase shift per milliwatt of thermal power. One milliwatt of thermal power is equivalent to 400 mg of plutonium (6% 240Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium

  6. Fiber Optic Calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Rudy, C.; Bayliss, S.; Bracken, D.; Bush, J.; Davis, P.

    1997-12-12

    A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using optical fibers for heat-flow measurements of special nuclear material. This calorimeter uses piezoelectric-generated phase-carrier modulation with subsequent electronic signal processes to allow phase shifts as small as 1 microradian ({micro}rad) to be measured. The sensing element consists of 21-m lengths of single-mode optical fiber wrapped around sample and reference chambers. The sensitivity of the calorimeter was determined to be 74 radians (rad) of phase shift per milliwatt of thermal power. One milliwatt of thermal power is equivalent to 400 mg of plutonium (6% {sup 240}Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium.

  7. Fiber optic calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Rudy, C.R.; Bayliss, S.C.; Bracken, D.S. [Los Alamos National Lab., NM (United States); Bush, I.J.; Davis, P.G. [Optiphase, Inc., Van Nuys, CA (United States)

    1998-12-31

    A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using optical fibers for heat-flow measurements of special nuclear material. This calorimeter uses piezoelectric-generated phase-carrier modulation with subsequent electronic signal processing to allow phase shifts as small as 1 {micro}rad to be measured. The sensing element consists of 21-m lengths of single-mode optical fiber wrapped around sample and reference chambers. The sensitivity of the calorimeter was determined to be 74 rad of phase shift per mW of thermal power. One milliwatt of thermal power is equivalent to 400 mg of plutonium (6% {sup 240}Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium.

  8. Modulated differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Sauerbrunn, S.R.; Crowe, B.S.; Reading, M. [TA Instruments Inc., New Castle, DE (United States)

    1993-12-31

    Modulated DSC (MDSC){sup tm} is a new patent-pending extension to conventional DSC which provides information about the reversing and nonreversing characteristics of thermal events. This additional information aids interpretation and allows unique insights into the structure and behavior of materials. Data presented will demonstrate three uses of MDSC. First, the overlapping crystallization peak and glass transition in a bilayer film of polycarbonate and PET are separated by MDSC. Second, the glass transition and endothermic relaxation of epoxy are separated. Third, MDSC gives a direct measurement of the sample heat capacity. The ability to separate reversing and nonreversing transitions, as well as the ability to directly measure heat capacity, offers thermal analysis another tool for solving tough materials characterization problems.

  9. LC-Circuit Calorimetry

    CERN Document Server

    Bossen, Olaf

    2011-01-01

    We present a new type of calorimeter in which we couple an unknown heat capacity with the aid of Peltier elements to an electrical circuit. The use of an electrical inductance and an amplifier in the circuit allows us to achieve autonomous oscillations, and the measurement of the corresponding resonance frequency makes it possible to accurately measure the heat capacity with an intrinsic statistical error that decreases as ~t^{-3/2} with measuring time t, as opposed to a corresponding error ~t^{-1/2} in the conventional alternating current (a.c.) method to measure heat capacities. We have built a demonstration experiment to show the feasibility of the new technique, and we have tested it on a gadolinium sample at its transition to the ferromagnetic state.

  10. Calorimetry triggering in ATLAS

    International Nuclear Information System (INIS)

    The ATLAS experiment is preparing for data taking at 14 TeV collision energy. A rich discovery physics program is being prepared in addition to the detailed study of Standard Model processes which will be produced in abundance. The ATLAS multi-level trigger system is designed to accept one event in 2 | 105 to enable the selection of rare and unusual physics events. The ATLAS calorimeter system is a precise instrument, which includes liquid Argon electro-magnetic and hadronic components as well as a scintillator-tile hadronic calorimeter. All these components are used in the various levels of the trigger system. A wide physics coverage is ensured by inclusively selecting events with candidate electrons, photons, taus, jets or those with large missing transverse energy. The commissioning of the trigger system is being performed with cosmic ray events and by replaying simulated Monte Carlo events through the trigger and data acquisition system.

  11. New ideas in calorimetry

    International Nuclear Information System (INIS)

    The problem of operating calorimeters which use scintillators in a strong magnetic field is explored. Ideas include using double wave shifting techniques to concentrate the light into a small area and then measuring it in place with solid state devices or microchannel plate photomultipliers or shipping the light remotely to normal phototubes via flexible light guides. Some novel schemes of casting plastic sheets with heavy metals for gas sampling calorimeters will also be discussed

  12. Hadronic Imaging Calorimetry

    CERN Document Server

    Kaplan, Alexander; Dubbers, Dirk

    This thesis focuses on a prototype of a highly granular hadronic calorimeter at the planned International Linear Collider optimized for the Particle Flow Approach. The 5.3 nuclear interaction lengths deep sandwich calorimeter was built by the CALICE collaboration and consists of 38 active plastic scintillator layers. Steel is used as absorber material and the active layers are subdivided into small tiles. In total 7608 tiles are read out individually via embedded Silicon Photomultipliers (SiPM). The prototype is one of the first large scale applications of these novel and very promising miniature photodetectors. The work described in this thesis comprises the commissioning of the detector and the data acquisition with test beam particles over several months at CERN and Fermilab. The calibration of the calorimeter and the analysis of the recorded data is presented. A method to correct for the temperature dependent response of the SiPM has been developed and implemented. Its successful application shows that it...

  13. Calorimetry with flash chambers

    International Nuclear Information System (INIS)

    The flash chambers used in the Fermilab E594 neutrino experiment are described, and their use in a calorimeter discussed. Resolutions obtained with a calibration beam are presented, and comments made about the pattern recognition capabilities of the calorimeter

  14. Why gas sampling calorimetry

    International Nuclear Information System (INIS)

    Until a few years ago gas sampling calorimeters were seldom used in high energy experiments where track multiplicities were low and energy resolutions obtained from scintillator sampling were substantially better than gas sampling. Gas sampling calorimeters have gained in popularity during the last few years because of needs for fine segmentation, especially in colliding beam experiments at super high energies in order to provide a detector with good pattern recognition capability and e, γ, π and μ identification within dense tracks. The gap in energy resolution between scintillator and gas sampling calorimeters has become less significant with recent advances in gas sampling. The papers contributed to the proceedings of this workshop are about some of the recent advances in this method

  15. Calorimetry in a Nutshell.

    Science.gov (United States)

    Markow, Peter

    1992-01-01

    Provides information on nutritional caloric value determination. Describes the chemical components of peanuts. Explains how to construct a soda can calorimeter for determining the heat released by a burning nut. Describes how to determine calories and kilocalories. Author asserts the activity can be adopted for children of any age. (eight…

  16. Calorimetry at the LHC

    International Nuclear Information System (INIS)

    The Calorimeter Working Group of this workshop was formed in April 1990. In order to define the performance criteria necessary for the extraction of the physics signals, usually in the presence of large backgrounds, the subgroup 'Physics versus Calorimeter Performance' convened by J.P. Repellin, worked closely with the Physics Working Group. This work is summarized in section 1. The Calorimeter Working Group devoted much time to the evaluation of the different calorimeter techniques with a view of their use at luminosities of 1034 cm-2 s-1 and higher. We present here a summary of the contributions made by a large number of people during the last six months. At the first working group meeting in April, subgroups for the different techniques were formed. The subgroups met independently and reported regularly at the working group meetings and finally during the first three days of the Aachen Workshop. Section 2 summarizes this work and short conclusions are given at the end of each of the sub-sections dealing with the individual calorimeter techniques. Section 2 also briefly summarizes the performance parameters relevant for the front-end electronics chain and recalls the radiation levels that the calorimeters will have to stand. (orig./HSI)

  17. Physical-chemical characterization and stability study of alpha-trypsin at ph 3.0 by differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Santos, A.M.C.; Santana, M.A.; Gomide, F.T.F.; Oliveira, J.S.; Vilas Boas, F.A.S.; Santoro, M.M.; Teixera, K.N. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Inst. de Ciencias Biologicas (ICB). Dept. de Bioquimica e Imunologia; Miranda, A.A.C.; Biondi, I. [Universidade Estadual de Feira de Santana (UEFS), BA (Brazil). Dept. de Ciencias Biologicas; Vasconcelos, A.B.; Bemquerer, M.P. [EMBRAPA Recursos Geneticos e Biotecnologia, Brasilia, DF (Brazil). Parque Estacao Biologica (PqEB)

    2008-07-01

    Full text: {alpha}-Trypsin is a serine-protease with a polypeptide chain of 223 amino acid residues and six disulfide bridges. It is a globular protein with predominance of antiparallel {beta}-sheet secondary structure and it has two domains with similar structures. In the present work, a stability study of {alpha}-trypsin in the acid pH range was performed and physical-chemical denaturation parameters were measured by using differential scanning calorimetry (DSC). The {alpha}-trypsin has a shelf-life (t{sub 95%}) of about ten months at pH 3.0 and 4 deg C and its hydrolysis into the {psi}-trypsin isoform is negligible during six months as monitored by mass spectrometry (Micromass Q-ToF). The observed {delta}H{sub cal}/{delta}H{sub vH} ratio is close to unity for {alpha}-trypsin denaturation, which suggests the occurrence of a two-state transition, devoid of molten-globule intermediates. At pH 3.0, {alpha}-trypsin unfolded with T{sub m} 325.9 K and {delta}H= 99.10 kcal mol{sup -1}, and the change in heat capacity between the native and unfolded forms of the protein was estimated to be 1.96 {+-} 0.18 kcal mol{sup -1} K{sup -1}. The stability of {alpha}-trypsin calculated at 298 K and at pH 3.0 was {delta}G{sub U} = 6.10 kcal mol{sup -1}. These values are in the range expected for a small globular protein. These results show that the thermodynamic parameters for unfolding of {beta}-trypsin do not change substantially after its conversion to {alpha}-trypsin.

  18. Measurement of heat capacity and thermal conductivity of HDPE/expanded graphite nanocomposites by differential scanning calorimetry

    Directory of Open Access Journals (Sweden)

    A. Ezan

    2011-07-01

    Full Text Available Purpose: In this study, heat capacity and thermal conductivity of nanocomposites formed by high density polyethylene (HDPE matrix and expanded graphite (EG conductive filling material were investigated.Design/methodology/approach: Nanocomposites containing up to 20 weight percent of expanded graphite filler material were prepared by mixing them in a Brabender Plasticorder. Two grades of expanded graphite fillers were used namely expanded graphite with 5 µm (EG5 and 50 µm (EG50 in diameter. Heat capacity and thermal conductivity of pure HDPE and the nanocomposites were measured using differential scanning calorimetry (DSC.Findings: A substantial increase in thermal conductivity was observed with the addition of expanded graphite to HDPE. Thermal conductivity increased from 0.442 W/m.K for pure HDPE to 0.938 W/m.K for nanocomposites containing 7% by weight of expended graphite. Heat capacity increases with the increase in temperature for both pure HDPE and the nanocomposites filled with expanded graphite and no appreciable difference in the values of heat capacity were detected due to particle size. Heat capacity decreased with increasing graphite particle content for both particle size, following the low of mixtures.Practical implications: Layers of expanded graphite have become of intense interest as fillers in polymeric nanocomposites. Upon mixing the expanded graphite intercalates and exfoliates into nanometer thickness sheets due to their sheet-like structure and week bonds normal to the graphite sheets. That way they have very big surface area and high aspect ratio (200−1500 what results in a formation of percolating network at very low filler content. The nanoparticles usage results in significant improvement in thermal, mechanical, and electrical properties of polymers even with very low loading levels compared with microparticles.Originality/value: To see the effect of conducting fillers on thermal conductivity and heat capacity two

  19. State of the water in crosslinked sulfonated poly(ether ether ketone). Two-dimensional differential scanning calorimetry correlation mapping

    Energy Technology Data Exchange (ETDEWEB)

    Al Lafi, Abdul G. [Department of Chemistry, Atomic Energy Commission, Damascus, P.O. Box 6091 (Syrian Arab Republic); Hay, James N., E-mail: cscientific9@aec.org.sy [The School of Metallurgy and Materials, College of Physical Sciences and Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2015-07-20

    Highlights: • 2D-DSC mapping was applied to analyze the heat flow responses of hydrated crosslinked sPEEK. • Two types of loosely bond water were observed. • The first was bond to the sulfonic acid groups and increased with ion exchange capacity. • The second was attributed to the polar groups introduced by ions irradiation and increased with crosslinking degree. • DSC combined with 2D mapping provides a powerful tool for polymer structural determination. - Abstract: This paper reports the first application of two-dimensional differential scanning calorimetry correlation mapping, 2D-DSC-CM to analyze the heat flow responses of sulphonated poly(ether ether ketone), sPEEK, films having different ion exchange capacity and degrees of crosslinks. With the help of high resolution and high sensitivity of 2D-DSC-CM, it was possible to locate two types of loosely bound water within the structure of crosslinked sPEEK. The first was bound to the sulfonic acid groups and dependent on the ion exchange capacity of the sPEEK. The second was bound to other polar groups, either introduced by irradiation with ions and dependent on the crosslinking degree or present in the polymer such as the carbonyl groups or terminal units. The results suggest that the ability of the sulfonic acid groups in the crosslinked sPEEK membranes to adsorb water molecules is increased by crosslinking, probably due to the better close packing efficiency of the crosslinked samples. DSC combined with 2D correlation mapping provides a fast and powerful tool for polymer structural determination.

  20. Physical-chemical characterization and stability study of alpha-trypsin at ph 3.0 by differential scanning calorimetry

    International Nuclear Information System (INIS)

    Full text: α-Trypsin is a serine-protease with a polypeptide chain of 223 amino acid residues and six disulfide bridges. It is a globular protein with predominance of antiparallel β-sheet secondary structure and it has two domains with similar structures. In the present work, a stability study of α-trypsin in the acid pH range was performed and physical-chemical denaturation parameters were measured by using differential scanning calorimetry (DSC). The α-trypsin has a shelf-life (t95%) of about ten months at pH 3.0 and 4 deg C and its hydrolysis into the Ψ-trypsin isoform is negligible during six months as monitored by mass spectrometry (Micromass Q-ToF). The observed ΔHcal/ΔHvH ratio is close to unity for α-trypsin denaturation, which suggests the occurrence of a two-state transition, devoid of molten-globule intermediates. At pH 3.0, α-trypsin unfolded with Tm 325.9 K and ΔH= 99.10 kcal mol-1, and the change in heat capacity between the native and unfolded forms of the protein was estimated to be 1.96 ± 0.18 kcal mol-1 K-1. The stability of α-trypsin calculated at 298 K and at pH 3.0 was ΔGU = 6.10 kcal mol-1. These values are in the range expected for a small globular protein. These results show that the thermodynamic parameters for unfolding of β-trypsin do not change substantially after its conversion to α-trypsin

  1. Detection of cervical cancer biomarker patterns in blood plasma and urine by differential scanning calorimetry and mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Nichola C Garbett

    Full Text Available Improved methods for the accurate identification of both the presence and severity of cervical intraepithelial neoplasia (CIN and extent of spread of invasive carcinomas of the cervix (IC are needed. Differential scanning calorimetry (DSC has recently been shown to detect specific changes in the thermal behavior of blood plasma proteins in several diseases. This methodology is being explored to provide a complementary approach for screening of cervical disease. The present study evaluated the utility of DSC in differentiating between healthy controls, increasing severity of CIN and early and advanced IC. Significant discrimination was apparent relative to the extent of disease with no clear effect of demographic factors such as age, ethnicity, smoking status and parity. Of most clinical relevance, there was strong differentiation of CIN from healthy controls and IC, and amongst patients with IC between FIGO Stage I and advanced cancer. The observed disease-specific changes in DSC profiles (thermograms were hypothesized to reflect differential expression of disease biomarkers that subsequently bound to and affected the thermal behavior of the most abundant plasma proteins. The effect of interacting biomarkers can be inferred from the modulation of thermograms but cannot be directly identified by DSC. To investigate the nature of the proposed interactions, mass spectrometry (MS analyses were employed. Quantitative assessment of the low molecular weight protein fragments of plasma and urine samples revealed a small list of peptides whose abundance was correlated with the extent of cervical disease, with the most striking plasma peptidome data supporting the interactome theory of peptide portioning to abundant plasma proteins. The combined DSC and MS approach in this study was successful in identifying unique biomarker signatures for cervical cancer and demonstrated the utility of DSC plasma profiles as a complementary diagnostic tool to evaluate

  2. Assessing the performance under ionising radiation of lead tungstate scintillators for EM calorimetry in the CLAS12 Forward Tagger

    Energy Technology Data Exchange (ETDEWEB)

    Fegan, S., E-mail: fegan@ge.infn.it [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Auffray, E. [CERN, European Organisation for Nuclear Research, Geneva (Switzerland); Battaglieri, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Buchanan, E. [University of Glasgow, Glasgow G12 8QQ (United Kingdom); Caiffi, B.; Celentano, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Colaneri, L.; D' Angelo, A. [Istituto Nazionale di Fisica Nucleare, Sezione Roma2 Tor Vergata and Università degli studi di Roma Tor Vergata, Via Scientifica 1, 00133 Roma (Italy); De Vita, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Dormenev, V. [II. Physikalisches Institut, Universität Gießen, 35392 Gießen (Germany); Fanchini, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Lanza, L. [Istituto Nazionale di Fisica Nucleare, Sezione Roma2 Tor Vergata and Università degli studi di Roma Tor Vergata, Via Scientifica 1, 00133 Roma (Italy); Novotny, R.W. [II. Physikalisches Institut, Universität Gießen, 35392 Gießen (Germany); and others

    2015-07-21

    The well-established technology of electromagnetic calorimetry using Lead Tungstate crystals has recently seen an upheaval, with the closure of one of the most experienced large-scale suppliers of such crystals, the Bogoroditsk Technical Chemical Plant (BTCP), which was instrumental in the development of mass production procedures for PWO-II, the current benchmark for this scintillator. Obtaining alternative supplies of Lead Tungstate crystals matching the demanding specifications of contemporary calorimeter devices now presents a significant challenge to detector research and development programmes. In this paper we describe a programme of assessment carried out for the selection, based upon the performance under irradiation, of Lead Tungstate crystals for use in the Forward Tagger device, part of the CLAS12 detector in Hall B at Jefferson Lab. The crystals tested were acquired from SICCAS, the Shanghai Institute of Ceramics, Chinese Academy of Sciences. The tests performed are intended to maximise the performance of the detector within the practicalities of the crystal manufacturing process. Results of light transmission, before and after gamma ray irradiation, are presented and used to calculate dk, the induced radiation absorption coefficient, at 420 nm, the peak of the Lead Tungstate emission spectrum. Results for the SICCAS crystals are compared with identical measurements carried out on Bogoroditsk samples, which were acquired for the Forward Tagger development program before the closure of the facility. Also presented are a series of tests performed to determine the feasibility of recovering radiation damage to the crystals using illumination from an LED, with such illumination available in the Forward Tagger from a light monitoring system integral to the detector.

  3. State of the water in crosslinked sulfonated poly(ether ether ketone). Two-dimensional differential scanning calorimetry correlation mapping

    International Nuclear Information System (INIS)

    Highlights: • 2D-DSC mapping was applied to analyze the heat flow responses of hydrated crosslinked sPEEK. • Two types of loosely bond water were observed. • The first was bond to the sulfonic acid groups and increased with ion exchange capacity. • The second was attributed to the polar groups introduced by ions irradiation and increased with crosslinking degree. • DSC combined with 2D mapping provides a powerful tool for polymer structural determination. - Abstract: This paper reports the first application of two-dimensional differential scanning calorimetry correlation mapping, 2D-DSC-CM to analyze the heat flow responses of sulphonated poly(ether ether ketone), sPEEK, films having different ion exchange capacity and degrees of crosslinks. With the help of high resolution and high sensitivity of 2D-DSC-CM, it was possible to locate two types of loosely bound water within the structure of crosslinked sPEEK. The first was bound to the sulfonic acid groups and dependent on the ion exchange capacity of the sPEEK. The second was bound to other polar groups, either introduced by irradiation with ions and dependent on the crosslinking degree or present in the polymer such as the carbonyl groups or terminal units. The results suggest that the ability of the sulfonic acid groups in the crosslinked sPEEK membranes to adsorb water molecules is increased by crosslinking, probably due to the better close packing efficiency of the crosslinked samples. DSC combined with 2D correlation mapping provides a fast and powerful tool for polymer structural determination

  4. Assessing the performance under ionising radiation of lead tungstate scintillators for EM calorimetry in the CLAS12 Forward Tagger

    International Nuclear Information System (INIS)

    The well-established technology of electromagnetic calorimetry using Lead Tungstate crystals has recently seen an upheaval, with the closure of one of the most experienced large-scale suppliers of such crystals, the Bogoroditsk Technical Chemical Plant (BTCP), which was instrumental in the development of mass production procedures for PWO-II, the current benchmark for this scintillator. Obtaining alternative supplies of Lead Tungstate crystals matching the demanding specifications of contemporary calorimeter devices now presents a significant challenge to detector research and development programmes. In this paper we describe a programme of assessment carried out for the selection, based upon the performance under irradiation, of Lead Tungstate crystals for use in the Forward Tagger device, part of the CLAS12 detector in Hall B at Jefferson Lab. The crystals tested were acquired from SICCAS, the Shanghai Institute of Ceramics, Chinese Academy of Sciences. The tests performed are intended to maximise the performance of the detector within the practicalities of the crystal manufacturing process. Results of light transmission, before and after gamma ray irradiation, are presented and used to calculate dk, the induced radiation absorption coefficient, at 420 nm, the peak of the Lead Tungstate emission spectrum. Results for the SICCAS crystals are compared with identical measurements carried out on Bogoroditsk samples, which were acquired for the Forward Tagger development program before the closure of the facility. Also presented are a series of tests performed to determine the feasibility of recovering radiation damage to the crystals using illumination from an LED, with such illumination available in the Forward Tagger from a light monitoring system integral to the detector

  5. Direct measurement of absorbed dose to water in HDR 192Ir brachytherapy: Water calorimetry, ionization chamber, Gafchromic film, and TG-43

    International Nuclear Information System (INIS)

    Purpose: Gafchromic film and ionometric calibration procedures for HDR 192Ir brachytherapy sources in terms of dose rate to water are presented and the experimental results are compared to the TG-43 protocol as well as with the absolute dose measurement results from a water calorimetry-based primary standard. Methods: EBT-1 Gafchromic films, an A1SL Exradin miniature Shonka thimble type chamber, and an SI HDR 1000 Plus well-type chamber (Standard Imaging, Inc., Middleton, WI) with an ADCL traceable Sk calibration coefficient (following the AAPM TG-43 protocol) were used. The Farmer chamber and Gafchromic film measurements were performed directly in water. All results were compared to direct and absolute absorbed dose to water measurements from a 4 deg. C stagnant water calorimeter. Results: Based on water calorimetry, the authors measured the dose rate to water to be 361±7 μGy/(h U) at a 55 mm source-to-detector separation. The dose rate normalized to air-kerma strength for all the techniques agree with the water calorimetry results to within 0.83%. The overall 1-sigma uncertainty on water calorimetry, ionization chamber, Gafchromic film, and TG-43 dose rate measurement amounts to 1.90%, 1.44%, 1.78%, and 2.50%, respectively. Conclusions: This work allows us to build a more realistic uncertainty estimate for absorbed dose to water determination using the TG-43 protocol. Furthermore, it provides the framework necessary for a shift from indirect HDR 192Ir brachytherapy dosimetry to a more accurate, direct, and absolute measurement of absorbed dose to water.

  6. Isothermal Titration Calorimetry Studies of the Binding of a Rationally Designed Analogue of the Antimicrobial Peptide Gramicidin S to Phospholipid Bilayer Membranes†

    OpenAIRE

    Abraham, Thomas; Lewis, Ruthven N. A. H.; Hodges, Robert S.; McElhaney, Ronald N.

    2005-01-01

    The binding of the positively charged antimicrobial peptide cyclo[VKLdKVdYPLKVKLdYP] (GS14dK4) to various lipid bilayer model membranes was investigated using isothermal titration calorimetry. GS14dK4 is a diastereomeric lysine ring-size analogue of the naturally occurring antimicrobial peptide gramicidin S which exhibits enhanced antimicrobial and markedly reduced hemolytic activities compared with GS itself. Large unilamellar vesicles composed of various zwitterionic (1-palmitoyl-2-oleoyl-s...

  7. The influence of dioxane on the hydration of bovine pancreatic α-chymotrypsin according to isothermal calorimetry and IR spectroscopy data

    Science.gov (United States)

    Sirotkin, V. A.; Korolev, D. V.

    2006-11-01

    The influence of dioxane on the thermochemical characteristics of the hydration of bovine pancreatic α-chymotrypsin enzyme over the whole range of water thermodynamic activities was studied by comparing the isothermal calorimetry data on the thermochemistry of interaction between the enzyme and water in the presence and absence of dioxane and using the IR spectral data on the adsorption of water and organic solvent vapors on the protein.

  8. Effect of sonication applied during production of carbon fiber/epoxy resin composites evaluated by differential scanning calorimetry and thermo-gravimetric analysis

    OpenAIRE

    Bogoeva-Gaceva, Gordana; Dimeski, Dimko; Herakovic, Niko

    2011-01-01

    The influence of ultrasonic treatment, applied during the impregnation of carbon fiber bundle by epoxy resin system, on thermal behavior of carbon fiber/epoxy resin composites in the course of crosslinknetwork formation has been analyzed by differential scanning calorimetry (DSC). It was previously shown [1] that this treatment has resulted in drastically increased interlaminar shear strength (ILSS) of the bulk composites, produced by hot pressing. The enhanced ILSS was attributed...

  9. Evaluation of polymerization of an experimental bonding resin cured with light emitting diodes using Differential Scanning Calorimetry

    Directory of Open Access Journals (Sweden)

    Jafarzadekashi T.

    2009-08-01

    Full Text Available "nBackground and Aim: Extent of polymerization (Ep is the rate at which methacrylate C=C bonds are converted to aliphatic C-C bonds. The higher the Ep value, the better the polymerization of the polymer. If the polymer dose not polymerize sufficiently, it could have destructive effects e.g. releasing monomer, initiator, free radical or insufficient polymerization of hybrid layer. Therefore, measuring the Ep value is very important. Light-emitting diodes (LEDs are becoming increasingly popular in dental practice as they have a long life expectancy. LEDs do not generate infrared wavelength, and have a constant light output. Therefore, comparison of LED and Quartz tungsten halogen (QTH from the point of Ep is important. Differential Scanning Calorimetry (DSC is a proper tool for determining the Ep value, monitoring the process of reaction and reaction kinetics. The aim of this study was to measure the Ep value of a dental bonding containing camphorquinone/amine photoinitiator which were cured by LED and QTH using DSC. "nMaterials and Methods: In this experimental study, 2.5 mg of bonding material were placed in DSC aluminum pans. Two different light cures, LED & QTH (Coltene Company Coltolux ®75 LED Curing Light, were used in this study. The light guide was positioned at a distance of 9mm from the base of the sample chamber. Each sample was photopolymerized for 30 seconds, and the DSC curves were obtained after 100 seconds from initiation of photopolimerization of each sample, at both 23oC and 37oC. The heat of photopolymerization (DH was calculated from the area under the peak of the differential temperature curve. Five samples were used for each condition. The data was analyzed by two-way ANOVA. "nResults: There was highly significant difference between two temperatures in the experimental bonding (pvalue<0.001. Representative DSC curves showed the same kinetic behavior for LED and QTH. "nConclusion: The results revealed that the Ep generated by

  10. SU-E-T-410: Fringe Stability and Phase Shift Measurements in a Michelson Interferometer for Optical Calorimetry

    International Nuclear Information System (INIS)

    Purpose: To identify the variables limiting the resolution of a Michelson interferometer used to measure phase shifts (PS) in water as part of a radiometric calorimeter. Methods: We investigated the output stability of a He-Ne laser and a laser diode. The short and long term stability of the fringe pattern in a Michelson interferometer was tested with different types of lasers, thermal insulation arrangements, damping systems and optical mounts to optimize system performance. PS were induced by electrically heating water in a 1 cm quartz cuvette located in one of the interferometer arms. The PS was calculated from fringe intensity changes and compared to a calculated PS using thermocouple-measured temperature changes in the water. Results: The intensity of the laser diode is more stable, but the gas laser’s profile is more suitable for fringe analysis and has better temporal coherence. The laser requires a warm-up time of 4 hours before its output is stabilized (SNR>95). The fringe’s stability strongly depends on the thermal insulation. When the interferometer is exposed to ambient temperature swings of 0.7 K, it is not possible to stabilize the fringe pattern. Enclosing the system in a 2.5 cm-thick Styrofoam box improves the SNR, but further insulation will be needed to increase the SNR above 50. High frequency noise is significantly reduced by damping the system.Inducing a temperature rise in water, starting at 299 K, the average temperature increase for a 2π PS is 0.29 ± 0.02 K and the proportionality constant is -21.1 ± 0.8 radians/K. This is 5.8% lower than the calculated value using the thermocouple. Conclusion: Interferometric PS measurements of temperature may provide an alternative to thermistors for water calorimetry. The resolution of the current prototype is limited by ambient temperature stability. Calculated and measured thermally-induced PS in water agreed to within 5.8%

  11. Hydration water and peptide dynamics--two sides of a coin. A neutron scattering and adiabatic calorimetry study at low hydration and cryogenic temperatures.

    Science.gov (United States)

    Bastos, Margarida; Alves, Nuno; Maia, Sílvia; Gomes, Paula; Inaba, Akira; Miyazaki, Yuji; Zanotti, Jean-Marc

    2013-10-21

    In the present work we bridge neutron scattering and calorimetry in the study of a low-hydration sample of a 15-residue hybrid peptide from cecropin and mellitin CA(1-7)M(2-9) of proven antimicrobial activity. Quasielastic and low-frequency inelastic neutron spectra were measured at defined hydration levels - a nominally 'dry' sample (specific residual hydration h = 0.060 g/g), a H2O-hydrated (h = 0.49) and a D2O-hydrated one (h = 0.51). Averaged mean square proton mobilities were derived over a large temperature range (50-300 K) and the vibrational density of states (VDOS) were evaluated for the hydrated samples. The heat capacity of the H2O-hydrated CA(1-7)M(2-9) peptide was measured by adiabatic calorimetry in the temperature range 5-300 K, for different hydration levels. The glass transition and water crystallization temperatures were derived in each case. The existence of different types of water was inferred and their amounts calculated. The heat capacities as obtained from direct calorimetric measurements were compared to the values derived from the neutron spectroscopy by way of integrating appropriately normalized VDOS functions. While there is remarkable agreement with respect to both temperature dependence and glass transition temperatures, the results also show that the VDOS derived part represents only a fraction of the total heat capacity obtained from calorimetry. Finally our results indicate that both hydration water and the peptide are involved in the experimentally observed transitions. PMID:23986181

  12. Thermal Analysis of Whole Bacterial Cells Exposed to Potassium Permanganate Using Differential Scanning Calorimetry: a Biphasic Dose-Dependent Response to Stress

    Directory of Open Access Journals (Sweden)

    Marina K. Abuladze

    2009-01-01

    Full Text Available Differential scanning calorimetry (DSC was applied to estimate the impact of the toxic oxidant potassium permanganate (PM on the intracellular structural and functional alterations at whole cell level using soil bacteria Arthrobacter oxydans as a model culture. Differential scanning calorimetry (DSC was applied in order to estimate the impact of the toxic oxidant potassium permanganate (PM on the intracellular structural and functional alterations at the whole cell level using the soil bacteria Arthrobacter oxydans as a model culture. We compared the total melting heat and the temperature of DNA-protein complex (DNP melting at the PM application prior to the calorimetry measurement and after 24-h exposure at the concentration range 0.02–1.4 mM. The initial oxidative effect caused changes in the pattern of the whole cell melting spectra (mainly at the temperature range 56–78°C, the decrease of Tmax °C DNP melting, and did not influence significantly the total heat of bacterial melting at different concentrations of PM. The prolonged effect of permanganate up to 24 h was characterized by a biphasic dose-dependent response to stress estimated by the DSC technique and the colony-forming assay. The low doses of PM (0.02 and 0.2 mM stimulated cell proliferation, and increased the total whole cell melting heat and the temperature of DNP melting. The toxic effect of PM up to 0.04 mM reduced cell viability, changed the character of multipeaked thermograms, and lowered the total melting heat and the temperature of DNP melting in a concentration-dependent manner. This study presents the DSC method for evaluating and monitoring the effects of exposure to potential human and environmental toxicants.

  13. An absorbed dose to water standard for HDR 192Ir brachytherapy sources based on water calorimetry: Numerical and experimental proof-of-principle

    International Nuclear Information System (INIS)

    Water calorimetry is an established technique for absorbed dose to water measurements in external beams. In this paper, the feasibility of direct absorbed dose measurements for high dose rate (HDR) iridium-192 (192Ir) sources using water calorimetry is established. Feasibility is determined primarily by a balance between the need to obtain sufficient signal to perform a reproducible measurement, the effect of heat loss on the measured signal, and the positioning uncertainty affecting the source-detector distance. The heat conduction pattern generated in water by the Nucletron microSelectron-HDR 192Ir brachytherapy source was simulated using COMSOL MULTIPHYSICSTM software. Source heating due to radiation self-absorption was calculated using EGSnrcMP. A heat-loss correction kc was calculated as the ratio of the temperature rise under ideal conditions to temperature rise under realistic conditions. The calorimeter setup used a parallel-plate calorimeter vessel of 79 mm diameter and 1.12 mm thick front and rear glass windows located 24 mm apart. Absorbed dose was measured with two sources with nominal air kerma strengths of 38 000 and 21 000 U, at source-detector separations ranging from 24.7 to 27.6 mm and irradiation times of 36.0 to 80.0 s. The preliminary measured dose rate per unit air kerma strength of (0.502±0.007) μGy/(s U) compares well with the TG-43 derived 0.505 μGy/(s U). This work shows that combined dose uncertainties of significantly less than 5% can be achieved with only modest modifications of current water calorimetry techniques and instruments. This work forms the basis of a potential future absolute dose to water standard for HDR 192Ir brachytherapy

  14. An absorbed dose to water standard for HDR 192Ir brachytherapy sources based on water calorimetry: numerical and experimental proof-of-principle.

    Science.gov (United States)

    Sarfehnia, Arman; Stewart, Kristin; Seuntjens, Jan

    2007-12-01

    Water calorimetry is an established technique for absorbed dose to water measurements in external beams. In this paper, the feasibility of direct absorbed dose measurements for high dose rate (HDR) iridium-192 (192Ir) sources using water calorimetry is established. Feasibility is determined primarily by a balance between the need to obtain sufficient signal to perform a reproducible measurement, the effect of heat loss on the measured signal, and the positioning uncertainty affecting the source-detector distance. The heat conduction pattern generated in water by the Nucletron microSelectron-HDR 192Ir brachytherapy source was simulated using COMSOL MULTIPHYSICS software. Source heating due to radiation self-absorption was calculated using EGSnrcMP. A heat-loss correction k(c) was calculated as the ratio of the temperature rise under ideal conditions to temperature rise under realistic conditions. The calorimeter setup used a parallel-plate calorimeter vessel of 79 mm diameter and 1.12 mm thick front and rear glass windows located 24 mm apart. Absorbed dose was measured with two sources with nominal air kerma strengths of 38 000 and 21 000 U, at source-detector separations ranging from 24.7 to 27.6 mm and irradiation times of 36.0 to 80.0 s. The preliminary measured dose rate per unit air kerma strength of (0.502 +/- 0.007) microGy/(s U) compares well with the TG-43 derived 0.505 microGy/(s U). This work shows that combined dose uncertainties of significantly less than 5% can be achieved with only modest modifications of current water calorimetry techniques and instruments. This work forms the basis of a potential future absolute dose to water standard for HDR 192Ir brachytherapy. PMID:18196821

  15. Miscibility, Crystallization, and Rheological Behavior of Solution Casting Poly(3-hydroxybutyrate)/poly(ethylene succinate) Blends Probed by Differential Scanning Calorimetry, Rheology, and Optical Microscope Techniques

    Science.gov (United States)

    Sun, Wei-hua; Qiao, Xiao-ping; Cao, Qi-kun; Liu, Jie-ping

    2010-02-01

    The miscibility and crystallization of solution casting biodegradable poly(3-hydroxybutyrate)/poly(ethylene succinate) (PHB/PES) blends was investigated by differential scanning calorimetry, rheology, and optical microscopy. The blends showed two glass transition temperatures and a depression of melting temperature of PHB with compositions in phase diagram, which indicated that the blend was partially miscible. The morphology observation supported this result. It was found that the PHB and PES can crystallize simultaneously or upon stepwise depending on the crystallization temperatures and compositions. The spherulite growth rate of PHB increased with increasing of PES content. The influence of compositions on the spherulitic growth rate for the partially miscible polymer blends was discussed.

  16. On structural phase transitions in 4-aminopyridinium fluoroborate, [4-NH 2C 5H 5N][BF 4]: differential scanning calorimetry, dielectric and infrared studies

    Science.gov (United States)

    Czupiński, O.; Jakubas, R.; Pietraszko, A.

    2004-10-01

    Crystal structure of the 4-aminopyridinium tetrafluoroborate, [4-NH 2C 5H 5N][BF 4], has been determined at 293 K by means of X-ray diffraction as monoclinic space group, C2. The crystal shows a reach sequence of phase transition, four solid-solid transitions: at 250, 281, 388 and 485 K on heating. Most of the phase transitions, except that at 388 K, are clearly of first order and classified as an 'order-disorder' type. The rotational disorder both of cations and anions was studied by differential scanning calorimetry, dielectric and infrared spectroscopy. The low temperature phase transitions are associated with plastic crystal behavior.

  17. Heat capacity measurements on YbGd2–Zr2O7 ( = 0, 1, 2) ceramics by differential scanning calorimetry

    Indian Academy of Sciences (India)

    Zhan-Guo Liu; Jia-Hu Ouyang; Yu Zhou

    2009-12-01

    YbGd2–Zr2O7 ( = 0, 1, 2) ceramics were pressureless-sintered using ceramic powders acquired by chemical-coprecipitation and calcination methods. Heat capacities of YbGd2–Zr2O7 were measured with a heat flux-type differential scanning calorimetry in the temperature range of 298–1200 K. At 298 K, the heat capacities of Gd2Zr2O7, YbGdZr2O7 and Yb2Zr2O7 were 214, 221 and 230 J.K-1 mol-1, respectively.

  18. Hydration water and peptide dynamics - two sides of a coin. A neutron scattering and adiabatic calorimetry study at low hydration and cryogenic temperatures

    OpenAIRE

    Margarida Bastos; Nuno Alves; Silvia Maia; Paula Gomes; Akira Inaba; Yuji Miyazaki; Jean Marc Zanotti

    2013-01-01

    In the present work we bridge neutron scattering and calorimetry in the study of a low-hydration sample of a 15-residue hybrid peptide from cecropin and mellitin CA(1-7)M(2-9) of proven antimicrobial activity. Quasielastic and low-frequency inelastic neutron spectra were measured at defined hydration levels a nominally dry sample (specific residual hydration h = 0.060 g/g), a H2O-hydrated (h = 0.49) and a D2O-hydrated one (h = 0.51). Averaged mean square proton mobilities were derived over a ...

  19. Evaluation of thermal stability of paraffin wax by differential scanning calorimetry; Avaliacao da estabilidade termica de parafina por calorimetria diferencial de varredura

    Energy Technology Data Exchange (ETDEWEB)

    Godinho, K.O.; Silva, A.G.P.; Holanda, J.N.F. [Universidade Estadual do Norte Fluminense (LAMAV/UENF), Campos dos Goytacazes, RJ (Brazil). Grupo de Materiais Ceramicos], Email: holanda@uenf.br

    2010-07-01

    Phase change materials for heat storage are used as passive solar energy storage materials, which can be impregnated into construction materials. In this work the thermal stability (heating/cooling cycle) of the paraffin wax was investigated using differential scanning calorimetry. The latent heat and fusion temperature were determined for the following thermal cycles: 0, 30, 180 and 360. The thermal stability for paraffin wax infiltrated in support of gypsum was also determined. The experimental results showed that the paraffin wax showed good thermal stability in the states pure and infiltrated for up to 360 thermal cycles. (author)

  20. Small-angle x-ray scattering and differential scanning calorimetry studies of DPPC multilamellar structures containing membranotropic agents of different chemical nature

    International Nuclear Information System (INIS)

    Multilamellar structures formed in DPPC/water/glycerol and DPPC/water/oxyethylated glycerol systems are studied by small-angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC) methods. The effects of glycerol, oxyethylated glycerol, and other membranotropic agents (MTAs) on the lamellar repeat distance D are compared in gel, ripple, and high-temperature (Lα) liquid crystal phases of the hydrated phospholipids. It is noted that the introduction of MTAs could lead to different types of 'D vs. temperature' behavior in the Lα phase, which is correlated with changes in D caused by the introduction of these substances to the DPPC/water reference system

  1. A preliminary study of the influence of ions in the pore solution of hardened cement pastes on the porosity determination by low temperature calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Min, E-mail: miwu@byg.dtu.dk [Department of Civil Engineering, Technical University of Denmark, Building 118, 2800 Lyngby (Denmark); Johannesson, Björn [Department of Civil Engineering, Technical University of Denmark, Building 118, 2800 Lyngby (Denmark); Geiker, Mette [Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim (Norway)

    2014-08-10

    Highlights: • Ionic concentrations in cement pore solution at freezing temperatures were simulated. • Effects of ions in determining pore sizes by low temperature calorimetry were studied. • Ions in cement pore solution affect the pore size determination to a limited extent. - Abstract: Thermodynamic modeling was used to predict the ionic concentrations in the pore solution of cement pastes at different temperatures during a freezing and melting measurement in low temperature calorimetry (LTC) studies. By using the predicted ionic concentrations, the temperature depressions caused by the ions presented in the pore solution were determined. The influence of the freezing/melting point depression caused by the ions on the determined pore size distribution by LTC was demonstrated. Thermodynamic modeling using the program PHREEQC was performed on the cylinder and powder samples of cement pastes prepared by two types of cements, i.e., CEM I 32.5 R and CEM III/B 42.5 N. Using the modeled ionic concentrations, the calculated differential pore size distributions for the studied samples with and without considering the temperature depression caused by the ions in the pore solution were compared. The results indicate that for the studied cement paste samples, the influence of the temperature depression caused by the presence of the ions in the pore solution on the determination of the pore size distribution by LTC is limited.

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

    Science.gov (United States)

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

    2016-03-01

    The reaction between ammonium chloride and sodium nitrite has been known for its application as a source of heat because of its large enthalpy of reaction, for which it has been used by the oil industry. There have been no known calorimetric studies for the experimental determination of its molar enthalpy of reaction, which is necessary in order to predict the limits achieved for up-scale applications. Attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) and reaction calorimetry were used to determine this value by using a simple methodology. Both techniques were used concomitantly as a source of information regarding the time-dependent moles converted (Δn) and the amount of exchanged heat (ΔH). The molar enthalpy of reaction was calculated to be -74 ± 4 kcal mol(-1). The percentage between the confidence interval and the calculated value was 5.4%, which shows that the methodology was precise. After the determination of the molar enthalpy of reaction, it was proved that the ATR FT-IR alone was able to be used as a substitute for the reaction calorimetry technique, in which the IR signal is converted to the heat information, presenting as an easier technique for the monitoring of the heat released by this system for future applications. PMID:26798078

  3. A preliminary study of the influence of ions in the pore solution of hardened cement pastes on the porosity determination by low temperature calorimetry

    International Nuclear Information System (INIS)

    Highlights: • Ionic concentrations in cement pore solution at freezing temperatures were simulated. • Effects of ions in determining pore sizes by low temperature calorimetry were studied. • Ions in cement pore solution affect the pore size determination to a limited extent. - Abstract: Thermodynamic modeling was used to predict the ionic concentrations in the pore solution of cement pastes at different temperatures during a freezing and melting measurement in low temperature calorimetry (LTC) studies. By using the predicted ionic concentrations, the temperature depressions caused by the ions presented in the pore solution were determined. The influence of the freezing/melting point depression caused by the ions on the determined pore size distribution by LTC was demonstrated. Thermodynamic modeling using the program PHREEQC was performed on the cylinder and powder samples of cement pastes prepared by two types of cements, i.e., CEM I 32.5 R and CEM III/B 42.5 N. Using the modeled ionic concentrations, the calculated differential pore size distributions for the studied samples with and without considering the temperature depression caused by the ions in the pore solution were compared. The results indicate that for the studied cement paste samples, the influence of the temperature depression caused by the presence of the ions in the pore solution on the determination of the pore size distribution by LTC is limited

  4. Low validity of the Sensewear Pro3 activity monitor compared to indirect calorimetry during simulated free living in patients with osteoarthritis of the hip

    DEFF Research Database (Denmark)

    Hermann, Andreas; Ried-Larsen, Mathias; Jensen, Andreas Emil Kryger;

    2014-01-01

    osteoarthritis (10 pre- and 10 post total hip arthroplasty; 40% female; age: 63.3 ± 9.0; BMI: 23.7 ± 3.7). All patients completed a 2 hour protocol of simulated free living with 8 different typical physical activity types. Energy consumption (kcal/min) was estimated by the Sense Wear pro3 Armband activity...... gardening. Both bias and variance appeared to be dependent on activity type. CONCLUSION: The activity monitor generally overestimated the energy consumption during common activities of low to medium intensity in the patient group. The size and direction of the bias was highly dependent on the activity type......BACKGROUND: To validate physical activity estimates by the Sensewear Pro3 activity monitor compared with indirect calorimetry during simulated free living in patients diagnosed with osteoarthritis of the hip pre or post total hip arthroplasty. METHODS: Twenty patients diagnosed with hip...

  5. Characteristics of rose hip (Rosa canina L.) cold-pressed oil and its oxidative stability studied by the differential scanning calorimetry method.

    Science.gov (United States)

    Grajzer, Magdalena; Prescha, Anna; Korzonek, Katarzyna; Wojakowska, Anna; Dziadas, Mariusz; Kulma, Anna; Grajeta, Halina

    2015-12-01

    Two new commercially available high linolenic oils, pressed at low temperature from rose hip seeds, were characterised for their composition, quality and DPPH radical scavenging activity. The oxidative stability of oils was assessed using differential scanning calorimetry (DSC). Phytosterols, tocopherols and carotenoids contents were up to 6485.4; 1124.7; and 107.7 mg/kg, respectively. Phenolic compounds determined for the first time in rose hip oil totalled up to 783.55 μg/kg, with a predominant presence of p-coumaric acid methyl ester. Antiradical activity of the oils reached up to 3.00 mM/kg TEAC. The acid, peroxide and p-anisidine values as well as iron and copper contents indicated good quality of the oils. Relatively high protection against oxidative stress in the oils seemed to be a result of their high antioxidant capacity and the level of unsaturation of fatty acids. PMID:26041218

  6. Evaluation of shrinkage temperature of bovine pericardium tissue for bioprosthetic heart valve application by differential scanning calorimetry and freeze-drying microscopy

    Directory of Open Access Journals (Sweden)

    Virgilio Tattini Jr

    2007-03-01

    Full Text Available Bovine pericardium bioprosthesis has become a commonly accepted device for heart valve replacement. Present practice relies on the measurement of shrinkage temperature, observed as a dramatic shortening of tissue length. Several reports in the last decade have utilized differential scanning calorimetry (DSC as an alternative method to determine the shrinkage temperature, which is accompanied by the absorption of heat, giving rise to an endothermic peak over the shrinkage temperature range of biological tissues. Usually, freeze-drying microscope is used to determine collapse temperature during the lyophilization of solutions. On this experiment we used this technique to study the shrinkage event. The aim of this work was to compare the results of shrinkage temperature obtained by DSC with the results obtained by freeze-drying microscopy. The results showed that both techniques provided excellent sensitivity and reproducibility, and gave information on the thermal shrinkage transition via the thermodynamical parameters inherent of each method.

  7. Capillary Condensation, Freezing, and Melting in Silica Nanopores: A Sorption Isotherm and Scanning Calorimetry Study on Nitrogen in Mesoporous SBA-15

    CERN Document Server

    Moerz, Sebastian T; Huber, Patrick; 10.1103/PhysRevB.85.075403

    2012-01-01

    Condensation, melting and freezing of nitrogen in a powder of mesoporous silica grains (SBA-15) has been studied by combined volumetric sorption isotherm and scanning calorimetry measurements. Within the mean field model of Saam and Cole for vapor condensation in cylindrical pores a liquid nitrogen sorption isotherm is well described by a bimodal pore radius distribution. It encompasses a narrow peak centered at 3.3 nm, typical of tubular mesopores, and a significantly broader peak characteristic of micropores, located at 1 nm. The material condensed in the micropores as well as the first two adsorbed monolayers in the mesopores do not exhibit any caloric anomaly. The solidification and melting transformation affects only the pore condensate beyond approx. the second monolayer of the mesopores. Here, interfacial melting leads to a single peak in the specific heat measurements. Homogeneous and heterogeneous freezing along with a delayering transition for partial fillings of the mesopores result in a caloric fr...

  8. Analysis of light particles correlation selected by neutron calorimetry in the reaction 208 Pb+93 Nb at 29 MeV/u

    International Nuclear Information System (INIS)

    This work deals with the analysis of light particles correlation selected by neutrons calorimetry in the reaction : 208 Pb+93 Nb at 29 MeV/u. In the first part are described the interest of correlation functions, the proton-proton correlation function study, the classical model developed for describing the correlations of two light particles emitted by a nucleus in thermal equilibrium, the quantum model and some notions about exclusive sources and measures. The second part is a description of the experience : 208 Pb+93 Nb at 29 MeV/u. The analysis of experimental data and of experimental correlation functions are given respectively in the third and the fourth parts. (O.L.). 38 refs., 82 figs., 11 tabs

  9. Mikrokalorimetrinin Hububat Teknolojisinde Kullanım İmkanları I. Differential Scanning Calorimetry (DSC) ve Yöntemin Genel Karakteristikleri

    OpenAIRE

    Certel, Muharrem; Ertugay, Zeki

    1991-01-01

    Hububat teknolojisinde, özellikle hububat ve ürünlerinden kalite kontrollerinde, basit ve hızlı bir ölçüm tekniği ile elde edilen sonuçların çok yönlülüğü nedeniyle, mikrokalorimetri günden güne artan bir önem arz etmektedir. Differential Scanning Calorimetry (DSC), gıdalardaki karbonhidrat, protein ve yağ komponentlerinin fonksiyonel özelliklerinin karakterize edilmesi ve bunların gıda teknolojisinde, özellikle de gıda işlem mühendisliğinde amaca yönelik olarak kullanımına imkan tanıyacak gü...

  10. The standard molar enthalpies of formation of Pb2Fe2O5(s) and PbFe5O8.5(s) by acid solution calorimetry

    International Nuclear Information System (INIS)

    Highlights: ► Acid solution calorimetry studies to determine the enthalpy of formation of ternary compounds in (Pb + Fe + O) system. ► Standard molar enthalpy of formation of lead ferrites at 298 K. ► The standard enthalpy of formation of Pb2Fe2O5(s) is −(1324.2 ± 11.1) kJ mol−1. ► The standard enthalpy of formation of PbFe5O8.5(s) is −(2347.8 ± 10.7) kJ mol−1. - Abstract: The standard molar enthalpies of formation, ΔfHm0 (298.15 K) of Pb2Fe2O5(s) and PbFe5O8.5(s) have been determined using acid solution calorimetry. The enthalpies of solution of the compounds Pb2Fe2O5(s) and PbFe5O8.5(s), as well as those of mixtures of Fe2O3(s) and Pb3O4(s) in HCl (aq, 6 mol·dm−3) at 298.15 K were measured. Using these values, the standard enthalpies of formation (ΔfHm0) of Pb2Fe2O5(s) and PbFe5O8.5(s) were determined as −(1324.2 ± 11.1) kJ·mol−1 and −(2347.8 ± 10.7) kJ·mol−1, respectively.

  11. Influência de alguns parâmetros experimentais nos resultados de análises calorimétricas diferenciais - DSC Influence of some experimental parameters on the results of differential scanning calorimetry - DSC.

    Directory of Open Access Journals (Sweden)

    Cláudia Bernal

    2002-09-01

    Full Text Available A series of experiments were performed in order to demonstrate to undergraduate students or users of the differential scanning calorimetry (DSC, that several factors can influence the qualitative and quantitative aspects of DSC results. Saccharin, an artificial sweetner, was used as a probe and its thermal behavior is also discussed on the basis of thermogravimetric (TG and DSC curves.

  12. Comparison between absorbed dose to water standards established by water calorimetry at the LNE-LNHB and by application of international air-kerma based protocols for kilovoltage medium energy x-rays

    International Nuclear Information System (INIS)

    Nowadays, the absorbed dose to water for kilovoltage x-ray beams is determined from standards in terms of air-kerma by application of international dosimetry protocols. New standards in terms of absorbed dose to water has just been established for these beams at the LNE-LNHB, using water calorimetry, at a depth of 2 cm in water in accordance with protocols. The aim of this study is to compare these new standards in terms of absorbed dose to water, to the dose values calculated from the application of four international protocols based on air-kerma standards (IAEA TRS-277, AAPM TG-61, IPEMB and NCS-10). The acceleration potentials of the six beams studied are between 80 and 300 kV with half-value layers between 3.01 mm of aluminum and 3.40 mm of copper. A difference between the two methods smaller than 2.1% was reported. The standard uncertainty of water calorimetry being below 0.8%, and the one associated with the values from protocols being around 2.5%, the results are in good agreement. The calibration coefficients of some ionization chambers in terms of absorbed dose to water, established by application of calorimetry and air-kerma based dosimetry protocols, were also compared. The best agreement with the calibration coefficients established by water calorimetry was found for those established with the AAPM TG-61 protocol. (paper)

  13. Analysis of the interactions between human serum albumin/amphiphilic penicillin in different aqueous media: an isothermal titration calorimetry and dynamic light scattering study

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Silvia [Grupo de Sistemas Complejos, Laboratorio de Fisica de Coloides y Polimeros, Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela (Spain); Taboada, Pablo [Grupo de Sistemas Complejos, Laboratorio de Fisica de Coloides y Polimeros, Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela (Spain)]. E-mail: fmpablo@usc.es; Mosquera, Victor [Grupo de Sistemas Complejos, Laboratorio de Fisica de Coloides y Polimeros, Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela (Spain)

    2005-04-04

    The complexation process of the amphiphilic penicillins sodium cloxacillin and sodium dicloxacillin with the protein human serum albumin (HSA) in aqueous buffered solutions of pH 4.5 and 7.4 at 25 {sup o}C was investigated through isothermal titration calorimetry (ITC) and dynamic light scattering. ITC experiments were carried out in the very dilute regime and showed that although hydrophobic interactions are the leading forces for complexation, electrostatic interactions also play an important role. The possibility of the formation of hydrogen bonds is also deduced from experimental data. The thermodynamic quantities of the binding mechanism, i.e, the enthalpy, {delta}HITCi, entropy, {delta}SITCi, Gibbs energy, {delta}GITCi, binding constant, KITCi and the number of binding sites, n{sub i}, were obtained. The binding was saturable and is characterised by Langmuir adsorption isotherms. From ITC data and following a theoretical model, the number of bound and free penicillin molecules was calculated. From Scatchard plots, KITCi and n{sub i} were obtained and compared with those from ITC data. The interaction potential between the HSA-penicillin complexes and their stability were determined at pH 7.4 from the dependence of the diffusion coefficients on protein concentration by application of the DLVO colloidal stability theory. The results indicate decreasing stability of the colloidal dispersion of the drug-protein complexes with increase in the concentration of added drug.

  14. Determination of thermodynamic potentials and the aggregation number for micelles with the mass-action model by isothermal titration calorimetry: A case study on bile salts.

    Science.gov (United States)

    Olesen, Niels Erik; Westh, Peter; Holm, René

    2015-09-01

    The aggregation number (n), thermodynamic potentials (ΔG, ΔH, ΔS) and critical micelle concentration (CMC) for 6 natural bile salts were determined on the basis of both original and previously published isothermal titration calorimetry (ITC) data. Different procedures to estimate parameters of micelles with ITC were compared to a mass-action model (MAM) of reaction type: n⋅S⇌Mn. This analysis can provide guidelines for future ITC studies of systems behaving in accordance with this model such as micelles and proteins that undergo self-association to oligomers. Micelles with small aggregation numbers, as those of bile salts, are interesting because such small aggregates cannot be characterized as a separate macroscopic phase and the widely applied pseudo-phase model (PPM) is inaccurate. In the present work it was demonstrated that the aggregation number of micelles was constant at low concentrations enabling determination of the thermodynamic potentials by the MAM. A correlation between the aggregation number and the heat capacity was found, which implies that the dehydrated surface area of bile salts increases with the aggregation number. This is in accordance with Tanford's principles of opposing forces where neighbouring molecules in the aggregate are better able to shield from the surrounding hydrophilic environment when the aggregation number increases. PMID:25978555

  15. The effect of feeding on CO2 production and energy expenditure in ponies measured by indirect calorimetry and the 13C-bicarbonate technique.

    Science.gov (United States)

    Jensen, R B; Kyrstein, T D; Junghans, P; Tauson, A H

    2015-11-01

    Energy expenditure (EE) can be estimated based on respiratory gas exchange measurements, traditionally done in respiration chambers by indirect calorimetry (IC). However, the (13)C-bicarbonate technique ((13)C-BT) might be an alternative minimal invasive method for estimation of CO(2) production and EE in the field. In this study, four Shetland ponies were used to explore the effect of feeding on CO(2) production and EE measured simultaneously by IC and (13)C-BT. The ponies were individually housed in respiration chambers and received either a single oral or intravenous (IV) bolus dose of (13)C-labelled sodium bicarbonate (NaH(13)CO(3)). The ponies were fed haylage 3 h before (T(-3)), simultaneously with (T(0)) or 3 h after (T(+3)) administration of (13)C-bicarbonate. The CO(2) produced and O(2) consumed by the ponies were measured for 6 h with both administration routes of (13)C-bicarbonate at the three different feeding times. Feeding time affected the CO(2) production (Phorses to avoid complex (13)C enrichment-time curves with maxima and shoulders as observed in several experiments with oral administration of (13)C-bicarbonate. PMID:26477528

  16. Non-isothermal crystallization kinetics and glass-forming ability of Ti41Zr25Be28Fe6 bulk metallic glass investigated by differential scanning calorimetry

    Science.gov (United States)

    Gong, Pan; Zhao, Shaofan; Wang, Xin; Yao, Kefu

    2015-07-01

    The non-isothermal crystallization kinetics and glass-forming ability of Ti41Zr25Be28Fe6 glassy alloy were investigated by differential scanning calorimetry. The activation energies corresponding to the characteristic temperatures have been calculated by Kissinger and Ozawa equations. Based on Kissinger-Akahira-Sunose and Ozawa-Flynn-Wall models, it has been found that the local activation energy is higher at the beginning of the crystallization process for the first exothermic peak. The local Avrami exponent indicates that the first-step crystallization is mainly a high-dimensional nucleation and growth with an increasing nucleation rate. According to the calculated fragility index, Ti41Zr25Be28Fe6 alloy can be classified as "strong glass former." The studied alloy also possesses a critical size up to centimeter order, and the high glass-forming ability is probably related to the relatively low Gibbs energy difference between the liquid and crystalline states. The critical cooling rate of Ti41Zr25Be28Fe6 glassy alloy has also been determined using Barandiaran-Colmenero's method.

  17. Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry - Thermogravimetry (DSC-TGA) and Evolved Gas Analysis (EGA)

    International Nuclear Information System (INIS)

    For vitrifying nuclear waste glass, the feed, a mixture of waste with glass-forming and modifying additives, is charged onto the cold cap that covers 90-100% of the melt surface. The cold cap consists of a layer of reacting molten glass floating on the surface of the melt in an all-electric, continuous glass melter. As the feed moves through the cold cap, it undergoes chemical reactions and phase transitions through which it is converted to molten glass that moves from the cold cap into the melt pool. The process involves a series of reactions that generate multiple gases and subsequent mass loss and foaming significantly influence the mass and heat transfers. The rate of glass melting, which is greatly influenced by mass and heat transfers, affects the vitrification process and the efficiency of the immobilization of nuclear waste. We studied the cold-cap reactions of a representative waste glass feed using both the simultaneous differential scanning calorimetry thermogravimetry (DSC-TGA) and the thermogravimetry coupled with gas chromatography-mass spectrometer (TGA-GC-MS) as complementary tools to perform evolved gas analysis (EGA). Analyses from DSC-TGA and EGA on the cold-cap reactions provide a key element for the development of an advanced cold-cap model. It also helps to formulate melter feeds for higher production rate

  18. Vibrational spectroscopic characterisation of salmeterol xinafoate polymorphs and a preliminary investigation of their transformation using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry

    International Nuclear Information System (INIS)

    Knowledge and control of the polymorphic phases of chemical compounds are important aspects of drug development in the pharmaceutical industry. Salmeterol xinafoate, a long acting β-adrenergic receptor agonist, exists in two polymorphic Forms, I and II. Raman and near infrared spectra were obtained of these polymorphs at selected wavelengths in the range of 488-1064 nm; significant differences in the Raman and near-infrared spectra were apparent and key spectral marker bands have been identified for the vibrational spectroscopic characterisation of the individual polymorphs which were also characterised with X ray diffractometry. The solid-state transition of salmeterol xinafoate polymorphs was studied using simultaneous in situ portable Raman spectroscopy and differential scanning calorimetry isothermally between transitions. This method assisted in the unambiguous characterisation of the two polymorphic forms by providing a simultaneous probe of both the thermal and vibrational data. The study demonstrates the value of a rapid in situ analysis of a drug polymorph which can be of potential value for at-line in-process control

  19. Dimyristoylphosphatidylcholine/C16 : 0-ceramide binary liposomes studied by differential scanning calorimetry and wide- and small-angle X-ray scattering

    DEFF Research Database (Denmark)

    Holopainen, J.M.; Lemmich, J.; Richter, F.; Mouritsen, O.G.; Rapp, G.; Kinnunen, P.K.J.

    2000-01-01

    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...... studied compositions there is an endotherm in the region close to the T-m for DMPC. At X-cer greater than or equal to 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 similar to 61 Angstrom at X-cer = 0.03, to 67 Angstrom at X-cer = 0...

  20. Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry - Thermogravimetry (DSC-TGA) and Evolved Gas Analysis (EGA)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Carmen P.; Pierce, David A.; Schweiger, Michael J.; Kruger, Albert A.; Chun, Jaehun; Hrma, Pavel R.

    2013-12-03

    For vitrifying nuclear waste glass, the feed, a mixture of waste with glass-forming and modifying additives, is charged onto the cold cap that covers 90-100% of the melt surface. The cold cap consists of a layer of reacting molten glass floating on the surface of the melt in an all-electric, continuous glass melter. As the feed moves through the cold cap, it undergoes chemical reactions and phase transitions through which it is converted to molten glass that moves from the cold cap into the melt pool. The process involves a series of reactions that generate multiple gases and subsequent mass loss and foaming significantly influence the mass and heat transfers. The rate of glass melting, which is greatly influenced by mass and heat transfers, affects the vitrification process and the efficiency of the immobilization of nuclear waste. We studied the cold-cap reactions of a representative waste glass feed using both the simultaneous differential scanning calorimetry thermogravimetry (DSC-TGA) and the thermogravimetry coupled with gas chromatography-mass spectrometer (TGA-GC-MS) as complementary tools to perform evolved gas analysis (EGA). Analyses from DSC-TGA and EGA on the cold-cap reactions provide a key element for the development of an advanced cold-cap model. It also helps to formulate melter feeds for higher production rate.

  1. Analysis of the interactions between human serum albumin/amphiphilic penicillin in different aqueous media: an isothermal titration calorimetry and dynamic light scattering study

    Science.gov (United States)

    Barbosa, Silvia; Taboada, Pablo; Mosquera, Victor

    2005-04-01

    The complexation process of the amphiphilic penicillins sodium cloxacillin and sodium dicloxacillin with the protein human serum albumin (HSA) in aqueous buffered solutions of pH 4.5 and 7.4 at 25 °C was investigated through isothermal titration calorimetry (ITC) and dynamic light scattering. ITC experiments were carried out in the very dilute regime and showed that although hydrophobic interactions are the leading forces for complexation, electrostatic interactions also play an important role. The possibility of the formation of hydrogen bonds is also deduced from experimental data. The thermodynamic quantities of the binding mechanism, i.e, the enthalpy, ΔHITCi, entropy, ΔSITCi, Gibbs energy, ΔGITCi, binding constant, KITCi and the number of binding sites, ni, were obtained. The binding was saturable and is characterised by Langmuir adsorption isotherms. From ITC data and following a theoretical model, the number of bound and free penicillin molecules was calculated. From Scatchard plots, KITCi and ni were obtained and compared with those from ITC data. The interaction potential between the HSA-penicillin complexes and their stability were determined at pH 7.4 from the dependence of the diffusion coefficients on protein concentration by application of the DLVO colloidal stability theory. The results indicate decreasing stability of the colloidal dispersion of the drug-protein complexes with increase in the concentration of added drug.

  2. Measurement of Nanomolar Dissociation Constants by Titration Calorimetry and Thermal Shift Assay – Radicicol Binding to Hsp90 and Ethoxzolamide Binding to CAII

    Directory of Open Access Journals (Sweden)

    Vilma Michailovienė

    2009-06-01

    Full Text Available The analysis of tight protein-ligand binding reactions by isothermal titration calorimetry (ITC and thermal shift assay (TSA is presented. The binding of radicicol to the N-terminal domain of human heat shock protein 90 (Hsp90aN and the binding of ethoxzolamide to human carbonic anhydrase (hCAII were too strong to be measured accurately by direct ITC titration and therefore were measured by displacement ITC and by observing the temperature-denaturation transitions of ligand-free and ligand-bound protein. Stabilization of both proteins by their ligands was profound, increasing the melting temperature by more than 10 ºC, depending on ligand concentration. Analysis of the melting temperature dependence on the protein and ligand concentrations yielded dissociation constants equal to 1 nM and 2 nM for Hsp90aN-radicicol and hCAII-ethoxzolamide, respectively. The ligand-free and ligand-bound protein fractions melt separately, and two melting transitions are observed. This phenomenon is especially pronounced when the ligand concentration is equal to about half the protein concentration. The analysis compares ITC and TSA data, accounts for two transitions and yields the ligand binding constant and the parameters of protein stability, including the Gibbs free energy and the enthalpy of unfolding.

  3. Establishment of Heat Treatment Process for Modified 440A Martensitic Stainless Steel Using Differential Scanning Calorimetry and Thermo-Calc Calculation

    Directory of Open Access Journals (Sweden)

    Huei-Sen Wang

    2015-12-01

    Full Text Available To provide a suitable microstructure and mechanical properties for modified Grade 440A martensitic stainless steel (MSS, which could facilitate the further cold deformation process (e.g., cold rolling, this work used differential scanning calorimetry (DSC and Thermo-Calc software to determine three soaking temperatures for annealing heat treatment processes (HT1, HT2 and HT3. To verify the feasibility of the proposed annealing heat treatment processes, the as-received samples were initially heated to 1050 °C (similar to the on-line working temperature for 30 min and air quenched to form a martensitic structure. The air-quenched samples were then subjected to three developed annealing heat treatment conditions. The microstructure and mechanical properties of the heat-treated samples were then investigated. Test results showed that considering the effects of the microstructure and the hardness, the HT1, the HT2 or the soaking temperatures between the HT1 and HT2 were the most recommended processes to modified Grade 440A MSS. When using the recommended processes, their carbides were fine and more evenly distributed, and the microhardness was as low as 210 Hv, which can be applied to the actual production process.

  4. Enthalpies of formation of CaAl4O7 and CaAl12O19 (hibonite) by high temperature, alkali borate solution calorimetry

    Science.gov (United States)

    Geiger, C. A.; Kleppa, O. J.; Grossman, L.; Mysen, B. O.; Lattimer, J. M.

    1988-01-01

    Enthalpies of formation were determined for two calcium aluminate phases, CaAl4O7 and CaAl12O19, using high-temperature alkali borate solution calorimetry. The aluminates were synthesized by multiple-cycle heating and grinding stoichiometric mixtures of CaCO3 and Al2O3, and the products were characteized by X-ray diffraction and SEM microbeam analysis. The data on impurities (CaAl4O7 was found to be about 89.00 percent pure by weight and the CaAl12O19 samples about 91.48 percent pure) were used to correct the heat of solution values of the synthetic products. The enthalpies of formation, at 1063 K, from oxides, were found to be equal to -(25.6 + or - 4.7) kJ/g.f.w. for CaAl4O7 and -(33.0 + or - 9.7) kJ/g.f.w. for CaAl12O19; the respective standard enthalpies of formation from elements, at 298 K, were estimated to be -4007 + or - 5.2 kJ/g.f.w. and -10,722 + or - 12 kJ/g.f.w.

  5. Analysis of light particles correlation selected by neutron calorimetry in the reaction {sup 208} Pb+{sup 93} Nb at 29 MeV/u; Analyse de correlation de particules legeres selectionnees par calorimetrie neutronique dans la reaction {sup 208} Pb+{sup 93} Nb a 29 MeV/u

    Energy Technology Data Exchange (ETDEWEB)

    Ghisalberti, C.

    1994-11-10

    This work deals with the analysis of light particles correlation selected by neutrons calorimetry in the reaction : {sup 208} Pb+{sup 93} Nb at 29 MeV/u. In the first part are described the interest of correlation functions, the proton-proton correlation function study, the classical model developed for describing the correlations of two light particles emitted by a nucleus in thermal equilibrium, the quantum model and some notions about exclusive sources and measures. The second part is a description of the experience : {sup 208} Pb+{sup 93} Nb at 29 MeV/u. The analysis of experimental data and of experimental correlation functions are given respectively in the third and the fourth parts. (O.L.). 38 refs., 82 figs., 11 tabs.

  6. Warm liquid calorimetry for LHC

    CERN Document Server

    Geulig,E; Wallraff,W; Bézaguet, Alain-Arthur; Cavanna, F; Cinnini, P; Cittolin, Sergio; Dreesen, P; Demoulin, M; Dunps, L; Fucci, A; Gallay, G; Givernaud, Alain; Gonidec, A; Jank, Werner; Maurin, Guy; Placci, Alfredo; Porte, J P; Radermacher, E; Samyn, D; Schinzel, D; Schmidt, W F; CERN. Geneva. Detector Research and Development Committee

    1990-01-01

    Results from the beam tests of the U/TMP "warm liquid" calorimeter show that such a technique is very promising for the LHC. Our aim is to extend this programme and design a calorimeter that can satisfy the requirements of high rates, high radiation levels, compensation, uniformity and granularity, as well as fully contain hadronic showers. We propose to construct liquid ionization chambers operated at very high fields, capable of collecting the total charge produced by ionizing particles within times comparable to the bunch crossing time of the future Collider. For this reason we plan to extend the current programme on tetramethylpentane (TMP) to tetramethylsilane (TMSi). An electromagnetic calorimeter consisting of very high field ionization chambers filled with TMSi as sensitive medium with Uranium and/or other high density material as absorber will first be built (to be followed by a full-scale calorimeter module), on which newly designed fast amplifiers and readout electronics will be tested. In addition...

  7. Calorimetry of epitaxial thin films.

    Science.gov (United States)

    Cooke, David W; Hellman, F; Groves, J R; Clemens, B M; Moyerman, S; Fullerton, E E

    2011-02-01

    Thin film growth allows for the manipulation of material on the nanoscale, making possible the creation of metastable phases not seen in the bulk. Heat capacity provides a direct way of measuring thermodynamic properties of these new materials, but traditional bulk calorimetric techniques are inappropriate for such a small amount of material. Microcalorimetry and nanocalorimetry techniques exist for the measurements of thin films but rely on an amorphous membrane platform, limiting the types of films which can be measured. In the current work, ion-beam-assisted deposition is used to provide a biaxially oriented MgO template on a suspended membrane microcalorimeter in order to measure the specific heat of epitaxial thin films. Synchrotron x-ray diffraction showed the biaxial order of the MgO template. X-ray diffraction was also used to prove the high quality of epitaxy of a film grown onto this MgO template. The contribution of the MgO layer to the total heat capacity was measured to be just 6.5% of the total addenda contribution. The heat capacity of a Fe(.49)Rh(.51) film grown epitaxially onto the device was measured, comparing favorably to literature data on bulk crystals. This shows the viability of the MgO∕SiN(x)-membrane-based microcalorimeter as a way of measuring the thermodynamic properties of epitaxial thin films. PMID:21361612

  8. Synergistic use of Knudsen effusion quadrupole mass spectrometry, solid-state galvanic cell and differential scanning calorimetry for thermodynamic studies on lithium aluminates

    International Nuclear Information System (INIS)

    Three ternary oxides LiAl5O8(s), LiAlO2(s) and Li5AlO4(s) in the system Li-Al-O were prepared by solid-state reaction route and characterized by X-ray powder diffraction method. Equilibrium partial pressure of CO2(g) over the three-phase mixtures {LiAl5O8(s)+Li2CO3(s)+5Al2O3(s)}, {LiAl5O8(s)+5LiAlO2(s)+2Li2CO3(s)} and {LiAlO2(s)+Li5AlO4(s)+2Li2CO3(s)} were measured using Knudsen effusion quadrupole mass spectrometry (KEQMS). Solid-state galvanic cell technique based on calcium fluoride electrolyte was used to determine the standard molar Gibbs energies of formations of these aluminates. The standard molar Gibbs energies of formation of these three aluminates calculated from KEQMS and galvanic cell measurements were in good agreement. Heat capacities of individual ternary oxides were measured from 127 to 868 K using differential scanning calorimetry. Thermodynamic tables representing the values of ΔfH0(298.15 K), S0(298.15 K) S0(T), Cp0(T), H0(T), {H0(T)-H0(298.15 K)}, G0(T), ΔfH0(T), ΔfG0(T) and free energy function (fef) were constructed using second law analysis and FACTSAGE thermo-chemical database software. - Graphical abstract: Comparison of ΔfGm0 of ternary oxides determined from KEQMS and solid-state galvanic cell techniques. (O) KEQMS, (9632;) solid-state galvanic cell and solid line: combined fit of both the experimental data

  9. Systems R-Fe-O (R=Ho, Er): Thermodynamic properties of ternary oxides using differential scanning calorimetry and solid-state electrochemical cells

    International Nuclear Information System (INIS)

    The thermodynamic properties of three different types of ternary oxides RFeO3(s), R3Fe5O12(s) and RFe2O4(s) (where R=Ho and Er) have been determined by calorimetric and solid-state galvanic cell methods. Heat capacities of RFeO3(s) and R3Fe5O12(s) have been determined by differential scanning calorimetry from 130 to 860K. Heat capacity measurements from 130 to 860K revealed λ-type anomalies for RFeO3(s) and R3Fe5O12(s) compounds which are assigned due to magnetic order-disorder transitions. The oxygen chemical potentials corresponding to the three-phase equilibria involving these ternary oxides have been determined by using solid-state electrochemical cells. The standard molar Gibbs energies of formation of RFeO3(s), R3Fe5O12(s) and RFe2O4(s) have been computed from the oxygen potential data. Based on the thermodynamic information, oxygen potential diagrams have been computed for the systems R-Fe-O (R=Ho and Er) at two different temperatures: T=1250 and 1450K. Thermodynamic functions like Cp,mo, Smo, Ho, Go, (HTo-H0o), (HTo-H298.15Ko), -(GTo-H298.15Ko)/T, ΔfHmo, and ΔfGmo have been generated for the compounds RFeO3(s) and R3Fe5O12(s) based on the experimental data obtained in this study and the available data in the literature

  10. Differential scanning calorimetry analysis of an enhanced LiNi0.8Co0.2O2 cathode with single wall carbon nanotube conductive additives

    International Nuclear Information System (INIS)

    Highlights: · Replaced 4 wt% carbon black conductive additives with 1 wt% single wall carbon nanotubes (SWCNTs) in cathode composite. · Use of SWCNT additive increased conductivity of cathode composite by over an order of magnitude. · SWCNT additive composite had triple the capacity at a 10C rate. · SWCNT additive composite reduced exothermic energy released upon delithiation by 40%. - Abstract: The replacement of traditional conductive carbon additives with single wall carbon nanotubes (SWCNTs) in lithium metal oxide cathode composites has been shown to enhance thermal stability as well as power capability and electrode energy density. The dispersion of 1 wt% high purity laser-produced SWCNTs in a LiNi0.8Co0.2O2 electrode created an improved percolation network over an equivalent composite electrode using 4 wt% Super C65 carbon black; evidenced by additive connectivity in SEM images and an order of magnitude increase in electrode electrical conductivity. The cathode with 1 wt% SWCNT additives showed comparable active material capacity (185-188 mAh g-1), at a low rate, and Coulombic efficiency to the cathode composite with 4 wt% Super C65. At increased cycling rates, the cathode with SWCNT additives had higher capacity retention with more than three times the capacity at 10C (16.4 mA cm-2). The thermal stability of the electrodes was evaluated by differential scanning calorimetry after charging to 4.3 V and float charging for 12 h. A 40% reduction of the cathode exothermic energy released was measured when using 1 wt% SWCNTs as the additive. Thus, the results demonstrate that replacing traditional conductive carbon additives with a lower weight loading of SWCNTs is a simple way to improve the thermal transport, safety, power, and energy characteristics of cathode composites for lithium ion batteries.

  11. Crystallization kinetics of Fe-B based amorphous alloys studied in-situ using X-rays diffraction and differential scanning calorimetry

    Directory of Open Access Journals (Sweden)

    Santos D.R. dos

    2001-01-01

    Full Text Available The crystallization processes for the amorphous metallic alloys Fe74B17Si2Ni4Mo3 and Fe86B6Zr7Cu1 (at. % were investigated using X-rays diffraction measurements performed in-situ during Joule-heating, with simultaneous monitoring of the electrical resistance. We determined the main structural transitions and crystalline phases formed during heating, and correlated these results to the observed resistance variations. As the annealing current is increased, the resistance shows an initial decrease due to stress relaxation, followed by a drop to a minimum value due to massive nucleation and growth of alpha-Fe nanocrystals. Further annealing causes the formation of small fractions of Fe-B, B2Zr or ZrO2, while the resistance increases due to temperature enhancement. In situ XRD measurements allowed the identification of metastable phases, as the gamma-Fe phase which occurs at high temperatures. The exothermal peaks observed in the differential scanning calorimetry (DSC for each alloy corroborate the results. We also have performed DSC measurements with several heating rates, which allowed the determination of the Avrami exponent and crystallization activation energy for each alloy. The obtained activation energies (362 and 301 kJ/mol for Fe-B-Zr-Cu; 323 kJ/mol for Fe-B-Si-Ni-Mo are comparable to reported values for amorphous iron alloys, while the Avrami exponent values (n = 1.0 or n = 1.2 are consistent with diffusion controlled crystallization processes with nucleation rates close to zero.

  12. Label-free characterization of carbonic anhydrase-novel inhibitor interactions using surface plasmon resonance, isothermal titration calorimetry and fluorescence-based thermal shift assays.

    Science.gov (United States)

    Rogez-Florent, Tiphaine; Duhamel, Laetitia; Goossens, Laurence; Six, Perrine; Drucbert, Anne-Sophie; Depreux, Patrick; Danzé, Pierre-Marie; Landy, David; Goossens, Jean-François; Foulon, Catherine

    2014-01-01

    This work describes the development of biophysical unbiased methods to study the interactions between new designed compounds and carbonic anhydrase II (CAII) enzyme. These methods have to permit both a screening of a series of sulfonamide derivatives and the identification of a lead compound after a thorough study of the most promising molecules. Interactions data were collected using surface plasmon resonance (SPR) and thermal shift assay (TSA). In the first step, experiments were performed with bovine CAII isoform and were extended to human CAII. Isothermal titration calorimetry (ITC) experiments were also conducted to obtain thermodynamics parameters necessary for the processing of the TSA data. Results obtained with this reference methodology demonstrate the effectiveness of SPR and TSA. KD values obtained from SPR data were in perfect accordance with ITC. For TSA, despite the fact that the absolute values of KD were quite different, the same affinity scale was obtained for all compounds. The binding affinities of the analytes studied vary by more than 50 orders of magnitude; for example, the KD value determined by SPR were 6 ± 4 and 299 ± 25 nM for compounds 1 and 3, respectively. This paper discusses some of the theoretical and experimental aspects of the affinity-based methods and evaluates the protein consumption to develop methods for the screening of further new compounds. The double interest of SPR, that is, for screening and for the quick thorough study of the interactions parameters (ka , kd , and KD ), leads us to choose this methodology for the study of new potential inhibitors. PMID:24375583

  13. Understanding the differential thermal behaviour of an oriented polymeric film, in response to the modulated differential scanning calorimetry variables, for determination of the degree of crystallinity

    Science.gov (United States)

    Ambardekar, Rohan; Karandikar, Hrushikesh; Kelly, Adrian; Caton-Rose, Phil; Coates, Phil; Paradkar, Anant

    2015-05-01

    The degree and the nature of crystallinity determine several key properties of an oriented polymeric system. Thermal analysis, although widely used for crystallinity determination, may have limited precision with oriented polymers, due to the differential nature and overlap of multiple thermal events (cold-crystallisation, chain-relaxation, etc). In this paper we have studied, how MDSC (Modulated Differential Scanning Calorimetry) variables manipulate the thermal behaviour of oriented materials, so that the degree and the nature of crystallisation can be well defined. MDSC curves suggested that the thermal events were significantly shaped by the amplitude (α) and the period (ρ) of thermal modulations. Anisotropic thermal conductivity of the oriented PLA film lead to generation of an error in the calculation of non-reversible signal, seen as an artefact in the crystallisation exotherm. Higher amplitude increased the sensitivity of the method. However, when the rise in the amplitude lead to a shift from a `heat-only' to a `heat-cool-heat' cycle, contribution from a poor baseline resulted in the low estimate of the crystallinity. For the `heat-only' cycles, measured crystallinity decreased inversely with the heating rate and α, due to time dependent crystallisation and melting. Heat-cool-heat cycles lead to crystallisation of some part of the polymer in a more perfected crystal form, whose melting was visible as a non-reversible event. The observations suggested that the heat-only cycles with longer period and faster heating rates favour estimation of the crystallinity, whereas heat-cool-heat cycles with higher amplitude help in understanding pre-melting thermal events associated with polymer orientation. A clear understanding of such an effect is necessary to establish the suitability of MDSC in rapid estimation of crystallinity of the oriented polymers. Accuracy of the method was evaluated by studying the films oriented to different draw ratios and comparison to

  14. Characterization of the 1st and 2nd EF-hands of NADPH oxidase 5 by fluorescence, isothermal titration calorimetry, and circular dichroism

    Directory of Open Access Journals (Sweden)

    Wei Chin-Chuan

    2012-04-01

    Full Text Available Abstract Background Superoxide generated by non-phagocytic NADPH oxidases (NOXs is of growing importance for physiology and pathobiology. The calcium binding domain (CaBD of NOX5 contains four EF-hands, each binding one calcium ion. To better understand the metal binding properties of the 1st and 2nd EF-hands, we characterized the N-terminal half of CaBD (NCaBD and its calcium-binding knockout mutants. Results The isothermal titration calorimetry measurement for NCaBD reveals that the calcium binding of two EF-hands are loosely associated with each other and can be treated as independent binding events. However, the Ca2+ binding studies on NCaBD(E31Q and NCaBD(E63Q showed their binding constants to be 6.5 × 105 and 5.0 × 102 M-1 with ΔHs of -14 and -4 kJ/mol, respectively, suggesting that intrinsic calcium binding for the 1st non-canonical EF-hand is largely enhanced by the binding of Ca2+ to the 2nd canonical EF-hand. The fluorescence quenching and CD spectra support a conformational change upon Ca2+ binding, which changes Trp residues toward a more non-polar and exposed environment and also increases its α-helix secondary structure content. All measurements exclude Mg2+-binding in NCaBD. Conclusions We demonstrated that the 1st non-canonical EF-hand of NOX5 has very weak Ca2+ binding affinity compared with the 2nd canonical EF-hand. Both EF-hands interact with each other in a cooperative manner to enhance their Ca2+ binding affinity. Our characterization reveals that the two EF-hands in the N-terminal NOX5 are Ca2+ specific. Graphical abstract

  15. Search for the scalar partner of the top quark and contribution to the improvement of the calorimetry of the experiment D zero for the phase 2 of Tevatron

    International Nuclear Information System (INIS)

    Supersymmetry could be the most natural extension of the Standard Model. In this thesis we present a new search for the sTop, the hypothetical scalar partner of the Top quark, that we performed in the framework of the Minimal Supersymmetric Standard Model (MSSM), using the Run I data of the DO experiment, which corresponds to an integrated luminosity of 108 pb-1. We selected events with one electron, one muon and missing transverse energy in the final state, which can be the decay product of pair of sTop quarks in 3 (t-tilde → blν-tilde), or 4-body (t-tilde → bχ-tilde10lνl). No signal is seen and the results are interpreted in terms of limits on the sTop production cross-section and exclusion regions in the parameter space (mt-tilde,mχ-tilde10) or (mt-tilde,mν-tilde). This new type of selection at the Tevatron for the search of the sTop allowed us to put stronger constraints than those previously published at LEP or at the Tevatron in the t-tilde → blν-tilde channel, and the first limits ever set in the 4-body decay channel. For the 3-body channel, assuming that the sneutrino is the lightest supersymmetric particle (LSP), the excluded region at 95% confidence level extends up to a sTop mass of 142 (130) GeV if the sneutrino mass (mν-tilde) is 43 (86) GeV. If the 4-body decay channel dominates, assuming that the neutralino is the LSP, the limit depends on the sneutrino mass. If it is light enough (mν-tilde ∼< 100 GeV) this limit reaches a sTop mass of 132 GeV for a neutralino mass of 60 GeV. In all searches for new particles, the calorimetry plays a crucial role from the experimental point of view. The expected increase in integrated luminosity in the Run II which started on the 1. of March 2001, and the detector upgrade which has been achieved over the last three years will allow to extend these exclusion domains or to discover the sTop. We thus also describe in this thesis our contribution to the calorimeter upgrade, both on the on-line calibration

  16. "Ideal glassformers" vs "ideal glasses": studies of crystal-free routes to the glassy state by "potential tuning" molecular dynamics, and laboratory calorimetry.

    Science.gov (United States)

    Kapko, Vitaliy; Zhao, Zuofeng; Matyushov, Dmitry V; Austen Angell, C

    2013-03-28

    also be highly fragile systems, approaching the "ideal glass" condition. We link this to the high "volume fragility" behavior observed in recent hard dumbbell studies at similar length∕diameter ratios [R. Zhang and K. S. Schweitzer, J. Chem. Phys. 133, 104902 (2010)]. The discussion suggests some unusual systems for laboratory study. Using differential scanning calorimetry detection of fusion points T(m), liquidus temperatures T(l), and glass transition temperatures T(g), we describe a system that would seem incapable of crystallizing before glass transition, i.e., an "ideal glassformer." The existence of crystal-free routes to the glassy state will eliminate precrystalline fluctuations as a source of the dynamic heterogeneities that are generally considered important in the discussion of the "glassy state problem [P. W. Anderson, Science 267, 1615 (1995)]." PMID:23556800

  17. ``Ideal glassformers'' vs ``ideal glasses'': Studies of crystal-free routes to the glassy state by ``potential tuning'' molecular dynamics, and laboratory calorimetry

    Science.gov (United States)

    Kapko, Vitaliy; Zhao, Zuofeng; Matyushov, Dmitry V.; Austen Angell, C.

    2013-03-01

    of "ideal glassformers" - single or multicomponent liquids that vitrify before ever becoming metastable with respect to crystals. We find evidence that "ideal glassformer" systems might also be highly fragile systems, approaching the "ideal glass" condition. We link this to the high "volume fragility" behavior observed in recent hard dumbbell studies at similar length/diameter ratios [R. Zhang and K. S. Schweitzer, J. Chem. Phys. 133, 104902 (2010), 10.1063/1.3483601]. The discussion suggests some unusual systems for laboratory study. Using differential scanning calorimetry detection of fusion points Tm, liquidus temperatures Tl, and glass transition temperatures Tg, we describe a system that would seem incapable of crystallizing before glass transition, i.e., an "ideal glassformer." The existence of crystal-free routes to the glassy state will eliminate precrystalline fluctuations as a source of the dynamic heterogeneities that are generally considered important in the discussion of the "glassy state problem [P. W. Anderson, Science 267, 1615 (1995), 10.1126/science.267.5204.1615-e]."

  18. O valor energético dos alimentos: exemplo de uma determinação experimental, usando calorimetria de combustão Food energy values: example of an experimental determination, using combustion calorimetry

    Directory of Open Access Journals (Sweden)

    Rui C. Santos

    2010-01-01

    Full Text Available The energies involved in the combustion, under atmosphere of oxygen, of breakfast cereals and dehydrate powdered whole milk samples, were determined by combustion calorimetry. This practical work, in the field of human nutrition, involved the characterization of the nutritional composition and the combustion of samples of the two foods that are part of the alimentary diet, namely, at breakfast. The obtained results allowed to assess the energy value printed in the foods labels and discuss the way those values are estimated.

  19. Thermal runaway potential of LiCoO2 and Li(Ni1/3Co1/3Mn1/3)O2 batteries determined with adiabatic calorimetry methodology

    International Nuclear Information System (INIS)

    Highlights: ► Thermal analysis is employed to classify hazardous rating for Li-ion cell cathodes. ► The thermal hazards of the LiCoO2 cathode at elevated temperatures is significant. ► VSP2 is an alternative measurement of a battery thermal stability evaluation. ► Calorimetry method provide the safety design considerations of Li-ion batteries. -- Abstract: Thermal runaway hazards related to adiabatic runaway reactions in various 18650 Li-ion batteries were studied in an adiabatic calorimeter with vent sizing package 2 (VSP2). We selected two cathode types, LiCoO2 and Li(Ni1/3Co1/3Mn1/3)O2, and tested Li-ion batteries to determine the thermal runaway features. The charged 18650 Li-ion batteries were tested to evaluate the thermal hazard characteristics, such as the initial exothermic temperature (T0), self-heating rate (dT/dt), pressure rise rate (dP/dt), pressure–temperature profiles, maximum temperature (Tmax) and pressure (Pmax), which are measured by VSP2 with a customized stainless steel test can. The thermal reaction behaviors of the Li-ion battery packs were shown to be an important safety concern for energy storage systems for power supply applications. The thermal abuse trials of the adiabatic calorimetry methodology used to classify the self-reactive ratings of the various cathodes for Li-ion batteries provided the safety design considerations.

  20. Search for the scalar partner of the top quark and contribution to the improvement of the calorimetry of the experiment D zero for the phase 2 of Tevatron; Recherche du partenaire supersymetrique du quark top et contribution a l'amelioration de la calorimetrie de l'experience D zero pour la phase 2 du tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, B

    2001-04-01

    Supersymmetry could be the most natural extension of the Standard Model. In this thesis we present a new search for the sTop, the hypothetical scalar partner of the Top quark, that we performed in the framework of the Minimal Supersymmetric Standard Model (MSSM), using the Run I data of the DO experiment, which corresponds to an integrated luminosity of 108 pb{sup -1}. We selected events with one electron, one muon and missing transverse energy in the final state, which can be the decay product of pair of sTop quarks in 3 (t-tilde {yields} bl{nu}-tilde), or 4-body (t-tilde {yields} b{chi}-tilde{sub 1}{sup 0}l{nu}{sub l}). No signal is seen and the results are interpreted in terms of limits on the sTop production cross-section and exclusion regions in the parameter space (m{sub t}-tilde,m{sub {chi}}-tilde{sub 1{sup 0}}) or (m{sub t}-tilde,m{sub {nu}}-tilde). This new type of selection at the Tevatron for the search of the sTop allowed us to put stronger constraints than those previously published at LEP or at the Tevatron in the t-tilde {yields} bl{nu}-tilde channel, and the first limits ever set in the 4-body decay channel. For the 3-body channel, assuming that the sneutrino is the lightest supersymmetric particle (LSP), the excluded region at 95% confidence level extends up to a sTop mass of 142 (130) GeV if the sneutrino mass (m{sub {nu}}-tilde) is 43 (86) GeV. If the 4-body decay channel dominates, assuming that the neutralino is the LSP, the limit depends on the sneutrino mass. If it is light enough (m{sub {nu}}-tilde {approx}< 100 GeV) this limit reaches a sTop mass of 132 GeV for a neutralino mass of 60 GeV. In all searches for new particles, the calorimetry plays a crucial role from the experimental point of view. The expected increase in integrated luminosity in the Run II which started on the 1. of March 2001, and the detector upgrade which has been achieved over the last three years will allow to extend these exclusion domains or to discover the sTop. We

  1. Estudio del gasto energético en la anorexia nerviosa: concordancia entre calorimetría indirecta y diferentes ecuaciones Study of energy expenditure in anorexia nervosa: agreement between indirect calorimetry and several equations

    Directory of Open Access Journals (Sweden)

    M.ª C. Cuerda Compés

    2005-12-01

    Full Text Available El tratamiento nutricional es fundamental en la anorexia nerviosa (AN, si bien la reposición de nutrientes debe hacerse de forma progresiva para evitar la aparición del síndrome de realimentación. Objetivo: Comparar el gasto energético en reposo (GER mediante calorimetría indirecta con el estimado con diferentes fórmulas en mujeres con AN. Material y Métodos: Estudiamos 21 mujeres ingresadas con AN (DSM-IV, edad 17 (DE 5,9 rango 12-34 años. El tiempo de ingreso fue 55,1 ± 20,7 días (21-91. La valoración nutricional inicial incluyó antropometría (IMC, PTC, PSE, CMB,CMMB y bioimpedancia tetrapolar (HoltainBC. La calorimetría indirecta (CI se realizó tras ayuno nocturno (Deltatrac TM II MBM-200. En 9 pacientes se repitió el mismo estudio antes del alta. Comparamos el GER (kcal/24 h medido por CI con el obtenido por diferentes ecuaciones [Fleisch, Harris-Benedict (HB, FAO, Schofield-HW (SHW, Schebendach] mediante el coeficiente de correlación intraclase (CCI y el método de Bland y Altman. Resultados: El estado nutricional mejoró significativamente durante la hopitalización. El 50% del peso recuperado fue masa grasa. El GER aumentó significativamente durante el ingreso. Las fórmulas sobrestimaron el GER respecto al obtenido por CI (p Nutritional management is essential in anorexia nervosa (AN, although nutrient replenishment must be done progressively to prevent the occurrence of re-alimentation syndrome. Objective: to compare resting energy expenditure (REE by means of indirect calorimetry and by different equations in AN female patients. Material and methods: we studied 21 women admitted for AN (DSM-IV, mean age 17 years (SD 5.9, range 12-34 years. Admission stay was 55.1 ± 20.7 days (21-91. Initial nutritional assessment included anthropometrics (BMJ, TSF, SSE, MAC, MAMC and tetrapolar bioimpedance (HoltainBC. Indirect calorimetry (IC was done after overnight fasting (DeltatracTM II MBM-200. In 9 patients, the same study

  2. Study of the stability of 5,10,15,20-tetraphenylporphine (TPP) and metalloporphyrins NiTPP, CoTPP, CuTPP, and ZnTPP by differential scanning calorimetry and thermogravimetry

    International Nuclear Information System (INIS)

    In this work, the stability of 5,10,15,20-tetraphenylporphine (TPP) and its metallic derivatives, NiTPP, CoTPP, CuTPP, and ZnTPP has been studied through differential scanning calorimetry and thermogravimetry. The decomposition temperatures are (712, 710, 708, 702, and 671) K for NiTPP, CoTPP, CuTPP, ZnTPP, and TPP, respectively. These values are in correspondence with the N-M bond length dM-N, of the metalloporphyrins. The corresponding molar enthalpies of melting ΔfusHm, were determined as (58, 57, 55, 52, and 44) kJ . mol-1 for the same series. These values are discussed in terms of the crystallographic features in the solid state.

  3. The effect of increasing membrane curvature on the phase transition and mixing behavior of a dimyristoyl-sn-glycero-3-phosphatidylcholine/distearoyl-sn-glycero-3-phosphatidylcholine lipid mixture as studied by Fourier transform infrared spectroscopy and differential scanning calorimetry

    DEFF Research Database (Denmark)

    Brumm, T.; Jørgensen, Kent; Mouritsen, Ole G.;

    1996-01-01

    The phase transition behavior of a lipid bilayer of dimyristoyl-sn-glycero-3-phosphalidylcholine/distearoyl-sn- glycero-3-phosphatidylcholine (DMPC-d54/DSPC) (1:1) on a solid support with varying curvatures was investigated with differential scanning calorimetry, infrared spectroscopy, and model...... calculations, With increasing curvature the temperatures of the liquidus and solidus points are shifted to lower values by up to 7 degrees C and 15 degrees C, and the mixing of the two lipid species in the two phase region is altered, With increasing curvature the DSPC dominates the gel phase, whereas the DMPC......-d54 is expelled to the fluid phase. Whereas the planar system shows a nearly simultaneous phase transition of DSPC and DMPC-d54, the spherical system with the highest curvature exhibits an almost complete separation of the phase transitions of the two lipids. Model calculations suggest that the shift...

  4. Avaliação nutricional de pacientes com cirrose pelo vírus da hepatite C: a aplicação da calorimetria indireta Nutritional assessment in patients with cirrhosis: the use of indirect calorimetry

    Directory of Open Access Journals (Sweden)

    Catarina Bertaso Andreatta Gottschall

    2004-12-01

    .BACKGROUND: Malnutrition is frequent in cirrhotic patients, and its assessment is difficult. Functional assessment through a dynamometer is a simple method and could minimize these drawbacks. Harris-Benedict prediction formulae estimates the resting energy expenditure but has not been validated for this population. One alternative is the use of indirect calorimetry. AIM: To assess nutritional status in cirrhotic patients and estimates the resting energy expenditure through indirect calorimetry and compares it to Harris-Benedict. PATIENTS AND METHODS: Thirty four adult hepatitis C cirrhotic outpatients were studied, classified by Child-Pugh and model of end-stage liver disease score. The resting energy expenditure was predicted through Harris-Benedict and measured by indirect calorimetry. Nutritional assessment was done through anthropometry, subjective global assessment, hand-grip strength and a 3-day recall. RESULTS: Fifteen (44.2% were Child-Pug A, 12 (35.3% B and 7 (20.6% C, and 33 (97.1% had model of end-stage liver disease scores less than 20. The resting energy expenditure predicted was higher than the measured (Harris-Benedict 1404.5 ± 150.3 kcal; indirect calorimetry 1059.9 ± 309.6 kcal. The prevalence of malnutrition varied between methods (body mass index, muscle arm circumference, subjective global assessment, triceps skinfold thickness and hand-grip strength: 0; 5.9; 17.6; 35.3 and 79.4%, accordingly. Calories and proteins intake were 80% and 85% of recommended amounts and there was inadequate intake of calcium, magnesium, iron and zinc. CONCLUSION: Malnutrition was frequent and hand-grip strength seemed to be the most sensitive method for its diagnosis. Calories and protein intakes were inadequate. Considering that the predicted resting energy expenditure was higher than the measured one and the need to offer higher caloric intake, the use of the predicting equation may replace indirect calorimetry.

  5. Calorimetría indirecta en el enfermo crítico: validez de la medición Indirect calorimetry in critical ill patients: validity of measurement for ten minutes

    Directory of Open Access Journals (Sweden)

    P. Marsé Milla

    2004-03-01

    Full Text Available Objetivo: No existen estándares definidos sobre la duración y frecuencia de la medición de la calorimetría indirecta, hecho que tiene importancia en la práctica asistencial diaria. Se valora el grado de concordancia entre el gasto energético en reposo (GER medido en un espacio de tiempo corto (10 minutos frente a otro prolongado (1 hora. Pacientes: Se estudiaron 60 pacientes críticos, sedoanalgesiados y conectados a ventilación mecánica. Intervenciones: El GER se determinó mediante un computador metabólico (Engström Eliza en condiciones de reposo. Se valoró la reproducibilidad y el grado de acuerdo de las mediciones hechas en ambos períodos de tiempo. Resultados: Los valores medios de las determinaciones de GER a 10 y 60 minutos fueron de 1818 ± 319 Kilocalorías/día y de 1815 ± 318 Kcal/día. Los límites de acuerdo entre ambos tiempos fueron de -101 a + 117 Kilocalorías/día y la correlación fue significativa (r = 0.98, p Goal: There are no gold standards on the duration and frequency of the measurement of indirect calorimetry, a fact of importance in daily clinical practice. An assessment of is made of the degree of concordance between energy expenditure at rest (EER measured over a short interval (10 minutes versus another prolonged measurement (1 hour. Patients: Sixty critically-ill patients, under sedation and analgesia with connection to mechanical ventilation, were studied. Interventions: EER values were determined by means of a metabolic computer analysis (Engström Eliza at rest. The reproducibility and the degree of concordance were assessed in the measurements made with both periods. Results: The mean values of the EER determinations at 10 and 60 minutes were 1,818 ± 319 kilocalories/day and 1,815 ± 318 Kcal/day. The limits of the concordance between both times were -101 and +117 kilocalories/day and the correlation was significant (r = 0.98, p < 0.0001. Conclusions: In critically-ill patients under sedation and

  6. The effect of continuous work on discretionary energy expenditure in male adult construction workers in northern Mexico as studies by the 2H218O method and indirect calorimetry

    International Nuclear Information System (INIS)

    Energy balance, in relation to energy needs in populations of developing countries is an important issue in terms of nutritional status, health and food policy implications. The objective of this study was to measure the variations in discretionary energy expenditure (DEE) in male adult construction workers of different body mass index (BMI), when challenged to heavy work. Twelve adult volunteers engaged in construction work, 18-30 years, BMI range 16.7 to 28.9 were selected from different low income urban sectors in northern Mexico. These individuals were subjected to a specific work load equivalent to a physical activity index (PAI) ≥ 2.1 x BMR, within a time frame of 6 hours a day, eight out of ten days. The rest of the time including one full weekend was to their discretion. Energy expenditure was measured using the 2H218O technique. BMR and the thermic effect of food were evaluated by ventilated hood indirect calorimetry. The energy cost of fixed activities was measured by the Oxylog. A daily activity diary was kept throughout the ten days of the protocol. This study shows no evidence that individuals of different energy status in a range of BMI from 16.7 to 28.9 modify the discretionary component of their total daily expenditure to cope with the equivalent of a heavy work load (PAI ≥ 2.1) 11 refs, 1 fig., 3 tabs

  7. Comparison of the doubly labeled water (2H2(18)O) method with indirect calorimetry and a nutrient-balance study for simultaneous determination of energy expenditure, water intake, and metabolizable energy intake in preterm infants

    International Nuclear Information System (INIS)

    The doubly labeled water method was compared with indirect calorimetry and a nutrient-balance study for simultaneous determination of rates of CO2 production, energy expenditure, and water intake over 5 days in four preterm infants. Additionally, metabolizable energy (ME) intake estimated using the isotope procedure (as energy expenditure plus an estimate for energy deposition based on weight gain), was compared to ME intake measured in the balance study. Compared to values obtained by traditional methods, calculated CO2 production, energy expenditure, and water intake differed by -1.4 +/- 4.8% (SD), +0.3 +/- 2.6%, and +5.7 +/- 1.4%, respectively; the difference in water intake was significant (p less than 0.05). Calculated ME intakes were 5.3 +/- 19.3% less than measured intakes, but the difference was not significant. These findings indicate that the doubly labeled water method can provide accurate information on rates of CO2 production, energy expenditure, and water intake in preterm infants, but individual estimates of ME intake may be subject to substantial error

  8. Non-isothermal crystallization kinetics and glass-forming ability of Ti{sub 41}Zr{sub 25}Be{sub 28}Fe{sub 6} bulk metallic glass investigated by differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Pan; Zhao, Shaofan; Yao, Kefu [Tsinghua University, School of Materials Science and Engineering, Beijing (China); Wang, Xin [Hebei University of Technology, School of Materials Science and Engineering, Tianjin (China)

    2015-07-15

    The non-isothermal crystallization kinetics and glass-forming ability of Ti{sub 41}Zr{sub 25}Be{sub 28}Fe{sub 6} glassy alloy were investigated by differential scanning calorimetry. The activation energies corresponding to the characteristic temperatures have been calculated by Kissinger and Ozawa equations. Based on Kissinger-Akahira-Sunose and Ozawa-Flynn-Wall models, it has been found that the local activation energy is higher at the beginning of the crystallization process for the first exothermic peak. The local Avrami exponent indicates that the first-step crystallization is mainly a high-dimensional nucleation and growth with an increasing nucleation rate. According to the calculated fragility index, Ti{sub 41}Zr{sub 25}Be{sub 28}Fe{sub 6} alloy can be classified as ''strong glass former.'' The studied alloy also possesses a critical size up to centimeter order, and the high glass-forming ability is probably related to the relatively low Gibbs energy difference between the liquid and crystalline states. The critical cooling rate of Ti{sub 41}Zr{sub 25}Be{sub 28}Fe{sub 6} glassy alloy has also been determined using Barandiaran-Colmenero's method. (orig.)

  9. In vitro model of infected stratum corneum for the efficacy evaluation of poloxamer 407-based formulations of ciclopirox olamine against Trichophyton rubrum as well as differential scanning calorimetry and stability studies.

    Science.gov (United States)

    Täuber, Anja; Müller-Goymann, Christel C

    2015-10-15

    Superficial fungal skin infections are a common disease and concern 20-25% of the world's population with the dermatophyte Trichophyton rubrum being the main trigger. Due to autoinoculation, fungal skin infections of the feet (tinea pedis) often occur simultaneously with fungal nail infections (onychomycosis). Therefore, the overall objective was the development and characterisation of poloxamer 407-based formulations with the antimycotic active ingredient ciclopirox olamine (CPX) for simultaneous antifungal therapy. The formulations consisted of poloxamer 407, water, isopropyl alcohol, propylene glycol and medium chain triglycerides in given ratios. The in vitro antifungal efficacy against T. rubrum was tested in a novel in vitro model of infected stratum corneum in comparison to a marketed semi-solid formulation containing 1% (w/w) ciclopirox olamine and a marketed nail lacquer containing 8% ciclopirox. Several liquid poloxamer 407-based formulations with only 1% CPX completely inhibited fungal growth after 6 days of incubation, whereas the marketed semi-solid formulation did not inhibit fungal growth. Differential scanning calorimetry studies revealing the interaction between the formulations and the SC showed that increasing isopropyl alcohol/propylene glycol concentrations as well as increasing CPX concentrations caused increasing endothermic transition shifts. Moreover, stability studies at 30 °C exhibited only a slight decrease of the CPX amount after 12 months of storage. Each formulation contained >90% of the initial CPX concentration after termination of the stability studies. PMID:26276254

  10. Electrical conductivity, differential scanning calorimetry, X-ray diffraction, and 7Li nuclear magnetic resonance studies of n-CxH(2x+1)OSO3Li (x = 12, 14, 16, 18, and 20)

    International Nuclear Information System (INIS)

    Electrical conductivity (σ), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) measurements of n-C xH(2x+1)OSO3Li (x= 12, 14, 16, 18, and 20) crystals were performed as a function of temperature. In addition, σ, DSC, and XRD observations of n-C xH(2x+1)OSO3Na and n-C xH(2x+1)OSO3K (x= 12, 14, 16, 18, and 20) crystals were carried out for comparison. DSC results of the salts revealed several solid-solid phase transitions with large entropy changes (ΔS). For n-C 18H37OSO3Li and n-C 20H41OSO3Li salts, each melting point produced a small ΔSmp value compared with the total entropy change in the solid phases (ΔStr1+ΔStr2). Additionally, Li + ion diffusion was detected in the highest temperature solid phases. For K salts, larger σ values were detected for potassium alkylsulfates compared with those reported for alkyl carboxylate. 7Li NMR spectra of n-C 18H37OSO3Li crystals recorded in the low-temperature phase showed large asymmetry parameters, suggesting the Li + ions are localized at asymmetric sites in the crystals

  11. Indirect calorimetry can be used to measure cardiac output in septic patients? A calorimetria indireta pode ser utilizada para medir o débito cardíaco em pacientes sépticos?

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora Martins

    2008-01-01

    Full Text Available PURPOSE: The aim of this study was to compare two different cardiac output (CO monitoring systems based on the thermodilution principle (Thermo-CO and indirect calorimetry (Fick mixed-CO in septic patients. METHODS: Prospective study in septic patients admitted in an intensive care unit of a university hospital. Nineteen patients aged on average 45.4 ± 21.5 years were enrolled in the study. Four series of hourly measurements by the two techniques were carried out simultaneously. RESULTS: No significant differences were observed between Thermo-CO and Fick mixed-CO (7.0 ± 1.8 L.min-1 and 6.4 ± 1.7 L.min-1.. Parallel analysis of Fick mixed-CO and Fick atrial-CO was performed introducing a correction factor for the eight atrial samples in order to adjust the values of oxygen saturation obtained from atrial blood (Fick corrected atrial-CO to those obtained from mixed venous blood. No significant differences could be detected between Fick mixed-CO and Fick corrected atrial-CO. The correlation coefficients of Thermo CO/Fick mixed-CO and Fick mixed-CO/Fick corrected atrial-CO were 0.84 and 0.94, respectively. CONCLUSION: We observed that the agreement between the two methods was satisfactory on the basis of the decisions made for treatment. Indirect calorimetry is useful to measure CO in patients with septic shock.OBJETIVO: O objetivo deste estudo foi comparar as medidas do débito cardíaco (DC obtidas pela termodiluição (DC-termo e pela calorimetria indireta (DC-Fick misto em pacientes com choque séptico. MÉTODOS: Estudo prospectivo em pacientes sépticos internados em unidade de terapia intensiva de um hospital universitário. Foram estudados 19 pacientes (45,4 ± 21,5 anos. Foram realizadas quatro séries de medidas do DC pelos dois métodos, simultaneamente. RESULTADOS: Não houve diferenças significativas entre os valores do DC-termo e DC-Fick misto (7,0 ± 1,8 L.min-1 e 6,4 ± 1,7 L.min-1, respectivamente. Na avaliação dos oito casos

  12. ATLAS calorimetry. Trigger, simulation and jet calibration

    International Nuclear Information System (INIS)

    The Pre-Processor system of the ATLAS Level-1 Calorimeter Trigger performs complex processing of analog trigger tower signals from electromagnetic and hadronic calorimeters. The main processing block of the Pre-Processor System is the Multi-Chip Module (MCM). The first part of this thesis describes MCM quality assurance tests that have been developed, their use in the MCM large scale production and the results that have been obtained. In the second part of the thesis a validation of a shower parametrisation model for the ATLAS fast simulation package ATLFAST based on QCD dijet events is performed. A detailed comparison of jet response and jet energy resolution between the fast and the full simulation is presented. The uniformity of the calorimeter response has a significant impact on the accuracy of the jet energy measurement. A study of the calorimeter intercalibration using QCD dijet events is presented in the last part of the thesis. The intercalibration study is performed in azimuth angle φ and in pseudorapidity η. The performance of the calibration methods including possible systematic and statistical effects is described. (orig.)

  13. Forward calorimetry for TeV-colliders

    International Nuclear Information System (INIS)

    A version of the compressed gas ionization calorimeter is presented based on stacks of stainless steel tubes. The volume between the tubes is filled with molded lead plates as passive material (including the tube walls). The active material is gas Ar+10%CH4, P=100 atm. Our Monte Carlo simulation was performed with the GEANT program, where the statistical term coefficient and constant term of the calorimeter energy resolution for protons and electrons are presented versus to the geometrical calorimeter parameters (inner tube diameter, volume ratio of passive to active materials, and angle). 6 refs.; 10 figs

  14. New detecting techniques for a future calorimetry

    Science.gov (United States)

    Auffray, E.; Buganov, O.; Fedorov, A.; Korjik, M.; Lecoq, P.; Tamulaitis, G.; Tikhomirov, S.; Vasil'ev, A.

    2015-02-01

    In the last forty years, application of crystalline materials in homogeneous Electromagnetic Calorimeters has played a crucial role in the discovery of matter properties and promoted a continuous progress in the detecting technique. The detection systems progressed from small detectors based on NaI(Tl), CsI(Na), BaF2, PbF2, and Bi4Ge3O12 to giant Electromagnetic Calorimeters of CMS, ALICE Collaborations at LHC and PANDA Collaboration at FAIR, where the systems consisted of thousands lead tungstate PbWO4 scintillation crystals. Lead tungstate (PWO) became the most extensively used scintillation material in high energy physics experiments. PWO possesses a unique combination of scintillation properties including high energy and time resolutions in the detection of high energy particles. Here, we report on the results of the two photon absorption in PWO crystals obtained by pump-probe technique using ultra short laser pulses. The results demonstrate that the relaxation processes in PWO offer capability of this material to be used in detection systems to make a time stamp with precision close to 10-12 s or even better.

  15. High resolution crystal calorimetry at LHC

    International Nuclear Information System (INIS)

    The search for Higgs bosons above Lep200 reach could be one of the main tasks of the future pp and ee colliders. In the intermediate mass region, and in particular in the range 80-140 GeV/c2, only the 2-photon decay mode of a Higgs produced inclusively or in association with a W, gives a good chance of observation. A 'dedicated' very high resolution calorimeter with photon angle reconstruction and pion identification capability should detect a Higgs signal with high probability. A crystal calorimeter can be considered as a conservative approach to such a detector, since a large design and operation experience already exists. The extensive R and D needed for finding a dense, fast and radiation hard crystal, is under way. Guide-lines for designing an optimum calorimeter for LHC are discussed and preliminary configurations are given. (author) 7 refs., 3 figs., 2 tabs

  16. Electromagnetic calorimetry with lead fluoride crystals

    International Nuclear Information System (INIS)

    The properties of four PbF2 crystals of size 21.21.175 mm3 were studied with electron and pion beams in the energy range from 1 to 6 GeV. An energy resolution for electrons of 6.3%/√(E/GeV) was achieved with a 2x2 matrix of four PbF2 crystals, which corresponds to 5.6%/√(E/GeV) when corrected for lateral leakage by Monte Carlo simulations. The deviation from linearity was smaller than 0.5%. The time resolution was found to be better than 0.6 ns. We studied also optical properties, radiation hardness, position resolution and spatial homogeneity. An efficient separation of electromagnetic and hadronic showers was achieved. (orig.)

  17. New ideas and developments in calorimetry

    International Nuclear Information System (INIS)

    The challenges for calorimeter performance in the next decade are reviewed. Some new ideas for calorimeters are described: (1) the test of a parallel plate calorimeter; (2) the use of vacuum photodiodes for calorimeters operating in a magnetic field; (3) the attempt to build high pressure gas sealed tubes as ion chambers in hadron calorimeters; (4) the progress in the attempt to mold plastic loaded with heavy metal for the inert material in gas calorimeters; and (5) the use of the limited streamer mode in calorimeters

  18. Hadron calorimetry in the L3 detector

    International Nuclear Information System (INIS)

    The characteristics of the L3 hadron calorimeter as realized in the observation of hadronic jets and other events from e+e- c collisions at LEP are presented and discussed. The pattern-recognition algorithm utilizing the fine granularity of the calorimeter is described, and the observed overall resolution of 10.2% for hadron jets from Z decay is reported. The use of the calorimeter in providing information on muon energy losses is also noted. (orig.)

  19. A simplistic view of hadron calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Groom, Donald E.

    2006-11-16

    All too often we rely on Monte Carlo simulations withoutworrying too much about basic physics. It is possible to start with avery simple calorimeter (a big cylinder) and learn the functional form ofpi e by aninduction argument. Monte Carlo simulations provide sanitychecks and constants. A power-law functional form describes test beamresults surprisingly well. The prediction that calorimeters responddifferently to protons and pions of the same energy was unexpected. Theeffect was later demonstrated by the CMS forward calorimeter group, usingthe most noncompensating calorimeter ever built. Calorimeter resolutionis dominated by fluctuations in piz production and the energy deposit byneutrons. The DREAM collaboration has recently used a dual readoutcalorimeter to eliminate the first of these. Ultimate resolution dependson measuring neutrons on an event-by-event basis as well.

  20. Precision electromagnetic calorimetry with liquid krypton

    International Nuclear Information System (INIS)

    Test beam results of a liquid krypton electromagnetic calorimeter with projective accordion electrode are presented. The electrode design includes a fine segmentation section to enhance the π0 rejection and pointing. The test was carried out at the H4 beam line at the CERN SPS with electron beams of energy from 20 to 200 GeV. Preliminary results of energy resolution, linearity, μ response are presented. The author also presents the dependence of the energy resolution on the amount of inactive material in front of the calorimeter

  1. ATLAS calorimetry. Trigger, simulation and jet calibration

    Energy Technology Data Exchange (ETDEWEB)

    Weber, P.

    2007-02-06

    The Pre-Processor system of the ATLAS Level-1 Calorimeter Trigger performs complex processing of analog trigger tower signals from electromagnetic and hadronic calorimeters. The main processing block of the Pre-Processor System is the Multi-Chip Module (MCM). The first part of this thesis describes MCM quality assurance tests that have been developed, their use in the MCM large scale production and the results that have been obtained. In the second part of the thesis a validation of a shower parametrisation model for the ATLAS fast simulation package ATLFAST based on QCD dijet events is performed. A detailed comparison of jet response and jet energy resolution between the fast and the full simulation is presented. The uniformity of the calorimeter response has a significant impact on the accuracy of the jet energy measurement. A study of the calorimeter intercalibration using QCD dijet events is presented in the last part of the thesis. The intercalibration study is performed in azimuth angle {phi} and in pseudorapidity {eta}. The performance of the calibration methods including possible systematic and statistical effects is described. (orig.)

  2. Experimental tests of particle flow calorimetry

    International Nuclear Information System (INIS)

    Precision physics at future colliders requires highly granular calorimeters to support the Particle Flow Approach for event reconstruction. This article presents a review of about 10-15 years of R and D, mainly conducted within the CALICE collaboration, for this novel type of detector. The performance of large scale prototypes in beam tests validate the technical concept of particle flow calorimeters. The comparison of test beam data with simulation, of e.g. hadronic showers, supports full detector studies and gives deeper insight into the structure of hadronic cascades than was possible previously.

  3. Integrated ceramic electrode for warm liquid calorimetry

    International Nuclear Information System (INIS)

    The authors describe the design and construction of a warm liquid media ionization cell to instrument the very forward collider region of the Superconducting Super Collider. This structure consists of an integrated ceramic electrode which combines the functions of mechanical support, anode charge collection, and high voltage feedthrough all into one unit. High internal electric fields and corresponding fast electron drift velocities are in principle achievable through flat, uniform metalization onto a pure ceramic substrate. A procedure to control electron affinic surface contamination below the parts-per-billion (ppb) level is described using an ultra-sensitive mass spectrometer

  4. Calorimetry measurements in less than 20 minutes

    Science.gov (United States)

    Perry, R. B.; Cremers, T.

    Argonne National Laboratory has developed a new series of 10 watt Bulk Plutonium Assay Calorimeters (BPAC10). The calorimeter measures bulk samples of plutonium bearing material in containers up to 5 in. in diameter and 7 in. high. The average measurement time is 19.7 minutes compared to 2-9 hours for the same sample measured in a water bath calorimeter. Measurement precision in the range of 1-10 watts is 1 to 0.1 percent and it is 0.010 watt for sample power less than 1 watt. The BPAC10 series calorimeters are in use in two plutonium facilities at the EG&G Rocky Flats Plant and at the Los Alamos National Laboratory TA55 Plutonium Facility. The paper presents a description of the calorimeter, discusses operating experience at Los Alamos, and presents a comparison of data on typical samples measured with both types of calorimeters.

  5. Electromagnetic calorimetry for the CMS detector

    International Nuclear Information System (INIS)

    Our group is involved in the construction of the electromagnetic calorimeter of CMS at LHC. This calorimeter is based on PbWO4 scintillating crystals. The light produced by the crystal is converted to electric signal by means of an avalanche photodiode. The signal is then amplified, compressed, digitized and transferred to the upper level readout by optic fibres. Our activity consists in evaluating the performances of such a system, investigating and developing part of the front end readout electronic and preparing the construction and exploitation of the detector. (authors)

  6. Performance of Particle Flow Calorimetry at CLIC

    CERN Document Server

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

    2013-01-01

    The experimental conditions at CLIC are also significantly more challenging than those at previous electron-positron colliders, with increased levels of beam-induced backgrounds combined with a bunch spacing of only 0.5 ns. This paper describes the modifications made to the PandoraPFA particle flow algorithm to improve the jet energy reconstruction for jet energies above 250 GeV. It then introduces a combination of timing and pT cuts that can be applied to reconstructed particles in order to significantly reduce the background. A systematic study is...

  7. Large lead tungstate crystals for calorimetry

    CERN Document Server

    Lecomte, P

    2000-01-01

    PbWO//4 crystals have been selected for the CMS Experiment at LHC, rather than the higher light yield but bulkier CeF//3, because space is at a premium in the 4T supraconductive magnet. Early PbWO//4 samples exhibited severe low dose radiation damage, slow components or long term afterglow. Thus, major R&D efforts have been undertaken by the Russian and Chinese producers. Besides improving the control of the raw materials, the stoichiometry and the growth parameters, the R&D efforts explored two avenues: doping of the crystals and oxygen annealing. Both groups have produced full size crystals which satisfy the requirements of CMS, including the low production cost which is an overwhelming consideration and a severe constraint in the optimization of the production process. This paper concentrates on the development of Chinese crystals; it attempts to guide the reader through the complex development process by giving a very brief description of the main steps and issues addressed in the past five years,...

  8. Expressing precision and bias in calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Hauck, Danielle K [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory; Bracken, David S [Los Alamos National Laboratory

    2010-01-01

    The calibration and calibration verification of a nuclear calorimeter represents a substantial investment of time in part because a single calorimeter measurement takes of the order of 2 to 24h to complete. The time to complete a measurement generally increases with the size of the calorimeter measurement well. It is therefore important to plan the sequence of measurements rather carefully so as to cover the dynamic range and achieve the required accuracy within a reasonable time frame. This work will discuss how calibrations and their verification has been done in the past and what we consider to be good general practice in this regard. A proposed approach to calibration and calibration verification is presented which, in the final analysis, makes use of all the available data - both calibration and verification collectively - in order to obtain the best (in a best fit sense) possible calibration. The combination of sample variance and percent recovery are traditionally taken as sufficient to capture the random (precision) and systematic (bias) contributions to the uncertainty in a calorimetric assay. These terms have been defined as well as formulated for a basic calibration. It has been tradition to assume that sensitivity is a linear function of power. However, the availability of computer power and statistical packages should be utilized to fit the response function as accurately as possible using whatever functions are deemed most suitable. Allowing for more flexibility in the response function fit will enable the calibration to be updated according to the results from regular validation measurements through the year. In a companion paper to be published elsewhere we plan to discuss alternative fitting functions.

  9. Topics in calorimetry for high energy physics

    International Nuclear Information System (INIS)

    These lectures focus on a series of topics now of interest or which have been of interest to designes of calorimeters in the past few years. The examples concentrate on calorimeters from DESY because its focus this year is on e-P physics, and on CDF and SDC because they are best known to the author. Calorimeters are, broadly speaking, devices to measure the total energy of particles. In general, no one device will be optimal for all types of particles. The two broadest classes of calorimeters in high energy physics are the electromagnetic calorimeters used primarily for photons and electrons, and the hadronic calorimeters used for most charged mesons and baryons. Most operate by absorbing and thereby measuring a significant amount of the incoming particles energy directly. Some particles may require special devices for their interactions and observation. Modern calorimeters are characterized by energy and position resolution, and cost and size. Calorimeter cost is often a trade-off between performance desired and money available. The optimum cost will require a careful choice of materials, reduction of the overall size of the detector, elimination of labor intensive construction techniques, and careful consideration of the cost of calibration systems. Since at least some of these requirements which optimize cost and resolution are contradictory, the ideal calorimeter in seldom what one ends up building

  10. Experimental Tests of Particle Flow Calorimetry

    CERN Document Server

    Sefkow, Felix; Kawagoe, Kiyotomo; Pöschl, Roman; Repond, José

    2015-01-01

    Precision physics at future colliders requires highly granular calorimeters to support the Particle Flow Approach for event reconstruction. This article presents a review of about 10 - 15 years of R\\&D, mainly conducted within the CALICE collaboration, for this novel type of detector. The performance of large scale prototypes in beam tests validate the technical concept of particle flow calorimeters. The comparison of test beam data with simulation, of e.g.\\ hadronic showers, supports full detector studies and gives deeper insight into the structure of hadronic cascades than was possible previously.

  11. New detecting techniques for a future calorimetry

    International Nuclear Information System (INIS)

    In the last forty years, application of crystalline materials in homogeneous Electromagnetic Calorimeters has played a crucial role in the discovery of matter properties and promoted a continuous progress in the detecting technique. The detection systems progressed from small detectors based on NaI(Tl), CsI(Na), BaF2, PbF2, and Bi4Ge3O12 to giant Electromagnetic Calorimeters of CMS, ALICE Collaborations at LHC and PANDA Collaboration at FAIR, where the systems consisted of thousands lead tungstate PbWO4 scintillation crystals. Lead tungstate (PWO) became the most extensively used scintillation material in high energy physics experiments. PWO possesses a unique combination of scintillation properties including high energy and time resolutions in the detection of high energy particles. Here, we report on the results of the two photon absorption in PWO crystals obtained by pump-probe technique using ultra short laser pulses. The results demonstrate that the relaxation processes in PWO offer capability of this material to be used in detection systems to make a time stamp with precision close to 10-12 s or even better

  12. Calorimetry measurements in less than 20 minutes

    International Nuclear Information System (INIS)

    Argonne National Laboratory has developed a new series of 10 watt Bulk Plutonium Assay Calorimeters (BPAC10). The calorimeter measures bulk samples of plutonium bearing material in containers up to 5in. in diameter and 7in. high. The average measurement time is 19.7 minutes compared to 2--9 hours for the same sample measured in a water bath calorimeter. Measurement precision in the range of 1--10 watts is 1% to 0.1% and it is 0.010 watt for sample power less than 1 watt. BPAC10 series calorimeters are in use in two plutonium facilities at the EG ampersand G Rocky Flats Plant and at the Los Alamos National Laboratory TA55 Plutonium Facility. The paper presents a description of the calorimeter, discusses operating experience at Los Alamos, and presents a comparison of data on typical samples measured with both types of calorimeters. 5 refs., 5 figs., 1 tab

  13. A simplistic view of hadron calorimetry

    International Nuclear Information System (INIS)

    All too often we rely on Monte Carlo simulations without worrying too much about basic physics. It is possible to start with a very simple calorimeter (a big cylinder) and learn the functional form of pi e by an induction argument. Monte Carlo simulations provide sanity checks and constants. A power-law functional form describes test beam results surprisingly well. The prediction that calorimeters respond differently to protons and pions of the same energy was unexpected. The effect was later demonstrated by the CMS forward calorimeter group, using the most noncompensating calorimeter ever built. Calorimeter resolution is dominated by fluctuations in piz production and the energy deposit by neutrons. The DREAM collaboration has recently used a dual readout calorimeter to eliminate the first of these. Ultimate resolution depends on measuring neutrons on an event-by-event basis as well

  14. Solution Calorimetry Experiments for Physical Chemistry.

    Science.gov (United States)

    Raizen, Deborah A.; And Others

    1988-01-01

    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)

  15. Characterization of DDGS using Differential Scanning Calorimetry

    Science.gov (United States)

    DDGS is one of the main coproducts obtained from corn dry grind ethanol processing. Cake formation/agglomeration in DDGS has been recognized as a major problem in its flowability and long term storage. In our previous studies, the physical and flow properties of DDGS were investigated using the Carr...

  16. Hadronic calibration of D0 calorimetry

    International Nuclear Information System (INIS)

    The D null detector is used to study p anti p collisions at the 1.8 TeV center-of-momentum energies available at the Fermilab Tevatron. The heart of the detector is a hermetic calorimeter employing uranium absorber and liquid argon as the ionization sampling medium. Several analyses require a well-understood jet energy scale. This paper describes how this calibration is obtained

  17. Cryogenic Laser Calorimetry for Impurity Analysis

    Science.gov (United States)

    Swimm, R. T.

    1985-01-01

    The results of a one-year effort to determine the applicability of laser-calorimetric spectroscopy to the study of deep-level impurities in silicon are presented. Critical considerations for impurity analysis by laser-calorimetric spectroscopy are discussed, the design and performance of a cryogenic laser calorimeter is described, and measurements of background absorption in high-purity silicon are presented.

  18. Molecular interactions between some non-steroidal anti-inflammatory drugs (NSAID's) and bovine (BSA) or human (HSA) serum albumin estimated by means of isothermal titration calorimetry (ITC) and frontal analysis capillary electrophoresis (FA/CE).

    Science.gov (United States)

    Ràfols, Clara; Zarza, Sílvia; Bosch, Elisabeth

    2014-12-01

    The interactions between some non-steroidal anti-inflammatory drugs, NSAIDs, (naproxen, ibuprofen and flurbiprofen) and bovine (BSA) or human (HSA) serum albumin have been examined by means of two complementary techniques, isothermal titration calorimetry (ITC) and frontal analysis/capillary electrophoresis (FA/CE). It can be concluded that ITC is able to measure with high precision the strongest drug-albumin interactions but the higher order interactions can be better determined by means of FA/CE. Then, the combination of both techniques leads to a complete evaluation of the binding profiles between the selected NSAIDs and both kind of albumin proteins. When BSA is the binding protein, the NSAIDs show a strong primary interaction (binding constants: 1.5 × 10(7), 8 × 10(5) and 2 × 10(6) M(-1) for naproxen, ibuprofen and flurbiprofen, respectively), and also lower affinity interactions of the same order for the three anti-inflammatories (about 1.7 × 10(4) M(-1)). By contrast, when HSA is the binding protein two consecutive interactions can be observed by ITC for naproxen (9 × 10(5) and 7 × 10(4) M(-1)) and flurbiprofen (5 × 10(6) and 6 × 10(4) M(-1)) whereas only one is shown for ibuprofen (9 × 10(5) M(-1)). Measurements by FA/CE show a single interaction for each drug being the ones of naproxen and flurbiprofen the same that those evaluated by ITC as the second interaction events. Then, the ability of both techniques as suitable complementary tools to establish the whole interaction NSAIDs-albumin profile is experimentally demonstrated and allows foreseeing suitable strategies to establish the complete drug-protein binding profile. In addition, for the interactions analyzed by means of ITC, the thermodynamic signature is established and the relative contributions of the enthalpic and entropic terms discussed. PMID:25159405

  19. Differential scanning calorimetry analysis of an enhanced LiNi{sub 0.8}Co{sub 0.2}O{sub 2} cathode with single wall carbon nanotube conductive additives

    Energy Technology Data Exchange (ETDEWEB)

    Ganter, Matthew J., E-mail: mjg9074@rit.edu [Golisano Institute for Sustainability, Rochester Institute of Technology, 111 Lomb Memorial Drive, Rochester, NY 14623 (United States); DiLeo, Roberta A., E-mail: rad0468@rit.edu [Microsystems Engineering, Rochester Institute of Technology, 111 Lomb Memorial Drive, Rochester, NY 14623 (United States); Schauerman, Christopher M., E-mail: cms3176@rit.edu [Golisano Institute for Sustainability, Rochester Institute of Technology, 111 Lomb Memorial Drive, Rochester, NY 14623 (United States); Rogers, Reginald E., E-mail: rerche@rit.edu [Chemical and Biomedical Engineering, Rochester Institute of Technology, 111 Lomb Memorial Drive, Rochester, NY 14623 (United States); Raffaelle, Ryne P., E-mail: ryne.raffaelle@nrel.gov [National Renewable Energy Laboratory, Golden Colorado, CO 84041 (United States); Landi, Brian J., E-mail: bjlsps@rit.edu [Chemical and Biomedical Engineering, Rochester Institute of Technology, 111 Lomb Memorial Drive, Rochester, NY 14623 (United States)

    2011-08-30

    Highlights: {center_dot} Replaced 4 wt% carbon black conductive additives with 1 wt% single wall carbon nanotubes (SWCNTs) in cathode composite. {center_dot} Use of SWCNT additive increased conductivity of cathode composite by over an order of magnitude. {center_dot} SWCNT additive composite had triple the capacity at a 10C rate. {center_dot} SWCNT additive composite reduced exothermic energy released upon delithiation by 40%. - Abstract: The replacement of traditional conductive carbon additives with single wall carbon nanotubes (SWCNTs) in lithium metal oxide cathode composites has been shown to enhance thermal stability as well as power capability and electrode energy density. The dispersion of 1 wt% high purity laser-produced SWCNTs in a LiNi{sub 0.8}Co{sub 0.2}O{sub 2} electrode created an improved percolation network over an equivalent composite electrode using 4 wt% Super C65 carbon black; evidenced by additive connectivity in SEM images and an order of magnitude increase in electrode electrical conductivity. The cathode with 1 wt% SWCNT additives showed comparable active material capacity (185-188 mAh g{sup -1}), at a low rate, and Coulombic efficiency to the cathode composite with 4 wt% Super C65. At increased cycling rates, the cathode with SWCNT additives had higher capacity retention with more than three times the capacity at 10C (16.4 mA cm{sup -2}). The thermal stability of the electrodes was evaluated by differential scanning calorimetry after charging to 4.3 V and float charging for 12 h. A 40% reduction of the cathode exothermic energy released was measured when using 1 wt% SWCNTs as the additive. Thus, the results demonstrate that replacing traditional conductive carbon additives with a lower weight loading of SWCNTs is a simple way to improve the thermal transport, safety, power, and energy characteristics of cathode composites for lithium ion batteries.

  20. Energy expenditure evaluation in humans and non-human primates by SenseWear Armband. Validation of energy expenditure evaluation by SenseWear Armband by direct comparison with indirect calorimetry.

    Directory of Open Access Journals (Sweden)

    Francesca Casiraghi

    Full Text Available INTRODUCTION: The purpose of this study was to compare and validate the use of SenseWear Armband (SWA placed on the arm (SWA ARM and on the back (SWA BACK in healthy humans during resting and a cycle-ergometer exercise and to evaluate the SWA to estimate Resting Energy Expenditure (REE and Total Energy Expenditure (TEE in healthy baboons. METHODS: We studied 26 (15F/11M human subjects wearing SWA in two different anatomical sites (arm and back during resting and a cycle-ergometer test and directly compared these results with indirect calorimetry evaluation (IC, performed at the same time. We then inserted the SWA in a metabolic jacket for baboons and evaluated the TEE and REE in free living condition for 6 days in 21 (8F/13M non-human primates. RESULTS: In humans we found a good correlation between SWA place on the ARM and on the BACK with IC during the resting experiment (1.1±0.3 SWAs, 1±0.2 IC kcal/min and a slight underestimation in the SWAs data compared with IC during the cycle-ergometer exercise (5±1.9 SWA ARM, 4.5±1.5 SWA BACK and 5.4±2.1 IC kcal/min. In the non-human primate (baboons experiment SWA estimated a TEE of 0.54±0.009 kcal/min during free living and a REE of 0.82±0.06 kcal/min. CONCLUSION: SWA, an extremely simple and inexpensive apparatus, provides quite accurate measurements of energy expenditure in humans and in baboons. Energy expenditure data obtained with SWA are highly correlated with the data obtained with "gold standard", IC, in humans.