Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Calorimetry data integration

Equations (l)-(4) provide the basic statistical thermodynamic framework necessary to deal with the protein folding problem. Several years ago, Freire and Biltonen (1978a) showed that scanning calorimetry data could be used to evaluate the protein folding/unfolding partition function experimentally by a double integration procedure ... [Pg.315]

Calorimetric methods are infrequently used for routine quality control purposes because of their non-specific nature and relatively slow speed. However, data from calorimetry experiments are commonly presented in applications for new product licenses and in support of patent applications. To ensure the integrity of all calorimetry data, normal procedures for good laboratory practices, standard operating procedures, appropriate calibration methods, and regular instrument servicing are necessary. The use of DSC for the measurement of transition temperatures and sample purity is described in the United States Pharmacopoeia, and standard procedures for DSC analyses are also suggested by the ASTM (100 Barr Harbor Dr., West Conshohocken, Pennsylvania 19428). [Pg.403]

FIGURE 13.5 Calorimetric and volumetric data obtained from adsorption calorimetry measurements Raw pressure and heat flow data obtained for each dose of probe molecule and Thermokinetic parameter (a), Volumetric isotherms (b), Calorimetric isotherms (c), Integral heats (d), Differential heats (e), Site Energy Distribution Spectrum (f). (From Damjanovic, Lj. and Auroux, A., Handbook of Thermal Analysis and Calorimetry, Further Advances, Techniques and Applications, Elsevier, Amsterdam, 387-438, 2007. With permission.)... [Pg.217]

As can be seen, the enthalpies of different apoxy-amine systems, according to different authors, lie in a rather narrow range (100-118 kJ per mole of epoxy groups, i.e. close to the heat of the epoxy ring opening). These data confirm the above conclusion as to the small total contribution of the donor-acceptor interactions in the epoxyamine systems to the observed integrated value of the heat release and the possibility of the application of the isothermal calorimetry method to the reaction kinetic studies. [Pg.126]

These data can be obtained from reaction calorimetry, which delivers the heat of reaction required for the determination of the adiabatic temperature rise (ATJ). The integration of the heat release rate can be used to determine the thermal conversion and the thermal accumulation (XJ). The accumulation may also be obtained from analytical data. [Pg.62]

The above information from electronic, atomic, and morphological levels must be integrated together with gas adsorption data to understand structures and functions of nanoporous systems. We must stress the importance of calorimetry and molecular... [Pg.15]

The estimate of the integral enthalpy (h) by Equation (19) is shown by the dashed lines in Figure 6. The solid lines are the experimental data determined by calorimetry. The error in the estimated enthalpy (dashed lines) increases with pressure but the largest error is 1.6%. The values at the two end points (yi=0 and yj = 1) are the integral enthalpies for pure ethylene and ethane given by Equation (11). [Pg.252]

The adiabatic calorimetry heat capacity data were available as supplementary material from the British Library Lending Division (SUP 21075), and were used in the preparation of the current review. The authors integrated the low-temperature heat capacity measurements and reported 138.7 J K -mol for 5 °(Nil2, cr). No contribution was added for the magnetic phase transition at 75 K to 76 K reported by Billerey et al. [77BIL/TER] and Kuindersma et al. [81KU1/SAN], and this may have led to an underestimation of between 0.3 J K mol and 0.5 J K mol in the value of 5 above 80 K. Indeed, the two most relevant values from the authors Run I (for 77.69 K and... [Pg.371]

Palenzola and Cirafici [1975PAL/CIR] have measured the enthalpies of formation of ThSn3(cr) by dynamic differential calorimetry (integration of DTA curves) from an appropriate mixture of the elements, held in a molybdennm container. As discussed in Appendix A, the DTA peak reached its maximnm at 793 K. Palenzola and Cirafici [1975PAL/CIR] report the valne of Af//° (ThSns, cr) = -(162 + 16) kJ-mof to be that at 298.15 K, but make no mention of any corrections applied to the experimental valne. We have therefore assumed the value to be that at the maximum in the DTA peak, 793 K and have doubled the uncertainty stated by the anthors. However, in view of the nncertainties in the processing of the data from both these studies, these values are quoted for information only. [Pg.380]

Fig. 10. Isothermal titration calorimetry of the binding of Sac7d to DNA at 80° showing the heat flow (A) following a series of 10 n,l injections of Sac7d (0.55 mAf) into poly(dG-dC) poly(dG-dC) (0.34 mM) in 10 mAf KH2PO4 (pH 6.8) and 25 xnM KCl. The baseline has been flattened by subtraction of a polynomial fit of the raw data. A fit of the integrated heats per mole of injected protein (B) with the McGhee-von Hippel model is shown with the solid curve through the data (A( = 1.04 x lO W", site size = 4.2 base pairs, A/f° = —52.5 kcal/mol). The first two points are inaccurate because of diffusion from the injection needle during equilibration and were not included in the fit. Fig. 10. Isothermal titration calorimetry of the binding of Sac7d to DNA at 80° showing the heat flow (A) following a series of 10 n,l injections of Sac7d (0.55 mAf) into poly(dG-dC) poly(dG-dC) (0.34 mM) in 10 mAf KH2PO4 (pH 6.8) and 25 xnM KCl. The baseline has been flattened by subtraction of a polynomial fit of the raw data. A fit of the integrated heats per mole of injected protein (B) with the McGhee-von Hippel model is shown with the solid curve through the data (A( = 1.04 x lO W", site size = 4.2 base pairs, A/f° = —52.5 kcal/mol). The first two points are inaccurate because of diffusion from the injection needle during equilibration and were not included in the fit.
The enthalpies of adsorption may be determined either directly by calorimetry or indirectly from the dependence of isosterics on temperature, as in the case of chromatography. Calorimetry measures only integral enthalpies whUe chromatography determines the differential enthalpies. The latter method is less accurate because it measures small differences between quantities at two temperatures, and matters become more complex if the enthalpy of adsorption varies with temperature. Gas chromatography at infinite dilution is the only certain method of measuring enthalpies at zero surface coverage [88] because it does not necessitate the extrapolation of data. [Pg.116]

Differential scanning calorimetry can be used to provide an insight into the thermal behavior of a gel. On heating, it is possible to observe an endotherm associated with the gel-sol transition, and on cooling, an exotherm can be observed as the sol reforms the gel. However, it should be noted that the conversion of a gel to a sol is not a first-order phase transition, as it is a multistep hierarchical process, and for this reason, the observed endotherms/exotherms can be very broad. However, if such peaks are observed, then integration can provide data about the enthalpy of the transition (A//gei-soi on heating and A//soi-gei on cooling). This method can also provide detailed information on the reversibility and repeatability of the gel-sol-gel transitions. [Pg.2684]

The heat capacity and transition enthalpy data required to evaluate Sm T ) using Eq. 6.2.2 come from calorimetry. The calorimeter can be cooled to about 10 K with liquid hydrogen, but it is difficult to make measurements below this temperature. Statistical mechanical theory may be used to approximate the part of the integral in Eq. 6.2.2 between zero kelvins and the lowest temperature at which a value of Cp,m can be measured. The appropriate formula for nonmagnetic nonmetals comes from the Debye theory for the lattice vibration of a monatomic crystal. This theory predicts that at low temperatures (from 0 K to about 30 K), the molar heat capacity at constant volume is proportional to Cv,m = aT, ... [Pg.152]

Co-crystal patents usually contain experimental examples that describe the preparation of the co-crystal and the characterization of the co-crystal. Characterization of the co-crystal describes the co-crystal itself and its various properties which include its sohd state characteristics and stoichiometry. Typically, the sohd state characteristics of a crystalline solid are shown by one or more of the foUowing analytical techniques X-ray powder diffraction pCRPD), single crystal X-ray diffraction (SCXD), Raman spectroscopy, infrared (IR) spectroscopy, sohd state nuclear magnetic resonance spectroscopy (SSNMR), and differential scanning calorimetry (DSC). The stoichiometry of a co-crystal may be estabhshed through solution techniques such as comparison of peak integrations in a solution NMR spectrum, data... [Pg.325]


See other pages where Calorimetry data integration is mentioned: [Pg.309]    [Pg.449]    [Pg.759]    [Pg.25]    [Pg.336]    [Pg.432]    [Pg.23]    [Pg.49]    [Pg.344]    [Pg.33]    [Pg.23]    [Pg.361]    [Pg.158]    [Pg.164]    [Pg.197]    [Pg.91]    [Pg.395]    [Pg.77]    [Pg.118]    [Pg.135]    [Pg.165]    [Pg.457]    [Pg.457]    [Pg.420]    [Pg.270]    [Pg.272]    [Pg.1131]    [Pg.341]    [Pg.324]    [Pg.321]    [Pg.562]    [Pg.204]    [Pg.252]    [Pg.224]   
See also in sourсe #XX -- [ Pg.4 , Pg.252 ]




SEARCH



Data integration

© 2024 chempedia.info