Data sets, reference format

Table II shows the "heats of formation" of the conjugate phases, that is, the excess enthalpies for mixing the appropriate amounts of water and amphiphile (at the same initial temperature and pressure as the final system) to make a unit amount of the conjugate phase. Values labeled "calorimeter" and "phase volume," respectively, are based on the same set of calorimetric titrations. In the former case the phase composition was taken from the calorimetric measurements, and in the latter case the composition was taken from our phase-volume compositions. Literature values for the heats of formation are based on data from references 13-16.

Representative heats of formation predicted by the ECP/BAC-MP4 method are given in Table 1 (the complete published [88] thermodynamic data set used in the analyses below is available online [91]). Data are shown for a range of compoimds, including tetravalent, trivalent, and divalent coordination at tin. Values for the reference compounds SnCU, SnH4, and Sn(CH3)4 are also given. Finally, heats of formation for atoms and groups needed to calculate reaction enthalpies are given. These results are used in the analysis below to identify potential reaction pathways for MBTC and its decomposition products. 

The term two-dimensional (2D) NMR spectrum refers to a data set where signal intensity is a function of two frequency domains (Fj and F2). The corresponding FID data are collected as a function of two time domains (detection and evolution/mixing) and then Fourier transformed in each dimension. The resulting data are most commonly displayed in a contour format. 

The maximum strain rate (e < Is1) for either extensional rheometer is often very slow compared with those of fabrication. Fortunately, time-temperature superposition approaches work well for SAN copolymers, and permit the elevation of the reduced strain rates kaj to those comparable to fabrication. Typical extensional rheology data for a SAN copolymer (h>an = 0.264, Mw = 7 kg/mol,Mw/Mn = 2.8) are illustrated in Figure 13.5 after time-temperature superposition to a reference temperature of 170°C [63]. The tensile stress growth coefficient rj (k, t) was measured at discrete times t during the startup of uniaxial extensional flow. Data points are marked with individual symbols (o) and terminate at the tensile break point at longest time t. Isothermal data points are connected by solid curves. Data were collected at selected k between 0.0167 and 0.0840 s-1 and at temperatures between 130 and 180 °C. Also illustrated in Figure 13.5 (dashed line) is a shear flow curve from a dynamic experiment displayed in a special format (3 versus or1) as suggested by Trouton [64]. The superposition of the low-strain rate data from two types (shear and extensional flow) of rheometers is an important validation of the reliability of both data sets. 

Accordingly with the institutional data refreshment policies based on the needs of individual institution, the content management subsystem will access the predefined datasets at selected public data banks and retrieve additional or updated reference data sets. The reference data refreshment policy is configurable by the researchers and maintained in a human-readable as well as machine-readable format by the content management subsystem. The data in the local reference data repository is maintained in a form that is optimal for the researchers chosen research applications. 

The ratio of the resistivity (R ) in sediment to the resistivity (R. ) in pore water defines the formation (resistivity) factor (F). (a) and (m) are constants which characterize the sediment composition. As Archie (1942) assumed that (m) indicates the consolidation of the sediment it is also called cementation exponent (cf. Sect. 3.2.2). Several authors derived different values for (a) and (m). For an overview please refer to Schon (1996). In marine sediments often Boyce s (1968) values (a = 1.3, m = 1.45), determined by studies on diatomaceous, silty to sandy arctic sediments, are applied. Nevertheless, these values can only be rough estimates. For absolutely correct porosities both constants must be calibrated by an additional porosity measurement, either on discrete samples or by gamma ray attenuation. Such calibrations are strictly only valid for that specific data set but, with little loss of accuracy, can be transferred to regional environments with similar sediment compositions. Wet bulk densities can then be calculated using equation 2.3 and assuming a grain density (cf. also section 3.2.2). 

In thermodynamic data tables (standard enthalpies or Gibbs energies of formation and standard molar entropies) which relate to compounds other than ions in a solution, the common convention that is applied involves setting the values of standard enthalpy and standard Gibbs energy of formation (or chemical potential) equal to OJmor for all simple pure elements in their stable physical state at the temperature in question. The data therefore refer to the formation of substances from simple elements. 

Reference Systems may be unique to a particular laboratory because antisera, extracts, etc. are prepared in t at laboratory by its own methods and from its own laboratory strains which that laboratory often uses as reference strains. An example of this are DNA or RNA extraction and testing procedures for homology studies. We present here a standardized format that facilitates design of coding data sets to record reference strain information. 

---