Measurements of properties

The basic data gathering methods are direct methods which allow visual inspection or at least direct measurement of properties, and indirect methods whereby we infer reservoir parameters from a number of measurements taken in a borehole. The main techniques available within these categories are summarised in the following table ... 

The central role of the concept of polarity in chemistry arises from the electrical nature of matter. In the context of solution chemistry, solvent polarity is the ability of a solvent to stabilize (by solvation) charges or dipoles. " We have already seen that the physical quantities e (dielectric constant) and p (dipole moment) are quantitative measures of properties that must be related to the qualitative concept of... 

Despite the plethora of data in the scientific literature on thermophysical quantities of substances and mixtures, many important data gaps exist. Predictive capabilities have been developed for problems such as vapor-liquid equihbrium properties, gas-phase and—less accmately—liquid-phase diffusivities, aud solubilities of uouelectrolytes. Yet there are many areas where improved predictive models would be of great value. Au accrrrate and rehable predictive model can obviate the need for costly, extensive experimental measurements of properties that are critical in chemical manufactming processes. 

All experimental sciences rely on quantitative measurements of properties. Every measurement gives a numerical result that has three aspects a numerical magnitude an indicator of scale, called a unit and a precision. Each aspect is essential, and all three must be reported to make a measurement scientifically valuable. 

B. Measurement of Property Distributions for Copolymers. Figure 12 shows chromatograms of typical products in the copolymerization study (Column Code B2). Since the detector is responding to concentration, composition, and periiaps sequence length, the direct single detector interpretation as described for PMMA is not immediately applicable here. Tacticity variation is yet another consideration but ]s assumed of sa ond order importance for th samples (22). 

It was subsequently shown that the presence of a catalyst accelerates the attainment of the ortho-para equilibrium. Measurements of properties such as the heat capacity and the thermal conductivity as a function of temperature then indicate that an equilibrium between the two species has been established. 

Using the methodology we have described, several indices of tableting performance have been developed by Hiestand and coworkers [29,31-33]. These indices provide relative measures of properties that are considered important and that reflect the performance of materials during processing. 

The problems have certainly been evident in test programmes made at Rapra, where different reactions appeared to occur at higher temperatures or the shapes of the curves of property change with time were complex. In these circumstances the success of applying Arrhenius relation will be very sensitive to the measure of property change with time that is chosen (see Section 12.2). 

The measurement of properties such as the resistivity or dielectric constant of PS requires some kind of contact with the PS layer. Evaporation of a metal onto the PS film-covered silicon sample produces a metal/PS/Si sandwich, which behaves like an MIS structure with an imperfect insulator. Such sandwich structures usually exhibit a rectifying behavior, which has to be taken into account when determining the resistivity [Si3, Bel4]. This can be circumvented by four-terminal measurements of free-standing PS films, but for such contacts the applied electric field has to be limited to rather small values to avoid undesirable heating effects. An electrolytic contact can also be used to probe PS films, but the interpretation of the results is more complicated, because it is difficult to distinguish between ionic and electronic contributions to the measured conductivity. The electrolyte in the porous matrix may short-circuit the silicon filaments, and wetting of PS in-... 

Note 3 Deformations and flows used in conventional measurements of properties of viscoelastic liquids and solids are usually interpreted assuming incompressibility. 

Standard Recommended Practice for Use of the Terms Precision and Accuracy as Applied to Measurement of Property of a Material", E 177-71, in Annual Book of Standards, part 41, American Society for testing and Materials Philadelphia, Pa., 1976. 

One class of flow measurement which is becoming of increasing importance (particularly in the form of sensors for control systems) is the monitoring of mass flow. This is rapidly superseding the measurement of volumetric flow—especially where it is required to determine accurately the transfer of large quantities of gas and liquid in the oil, gas and water industries. Two principal approaches are employed to measure mass flow. One is indirect and uses a combination of volumetric flow and density and the other is direct in that it involves the measurement of properties which are sensitive to variations in the mass rate of flow itself. 

Table IV Techniques for Measurement of Properties of Mineral/ Particle Solution Interfaces...

Random samples of size ten were drawn from normal populations A, B, C and D. The measurements of property X are given in the table below along with totals and sums of squares in columns. 

The commonest methods of quantitation in general practice depend upon photometric measurements, after staining the protein fractions in situ on the paper. Newer methods, which will be given first are based on the measurement of properties other than the dye-binding capacity of the protein fractions. Some of these methods, which avoid the many... 

MEASUREMENTS OF properties. Water-leaf handsheets at a basis weight of about 75 g/m were prepared from the BP and UBP pulps using a Williams Standard Sheet Mould. Solubility in hot-l%-sodium hydroxide was determined by TAPPI method T212 om 83. Intrinsic viscosity in cuene (cupraethylenediamine solution) and, therefrom, the DPV were determined according to ASTM Standard D1795. 

Other measures of properties in 3D, such as Molecular Lipophilicity Potential (MLPot) and Molecular Hydrogen Bond Potential (MHBP), have been used to characterize 3D properties. They are defined for points on a molecular surface created around the molecule and calculated from the summation of contributions from the substructural fragments making up the molecule weighted by the distance function. The hydrogen bond potentials include an angle-dependent function. 

Many different methods can be used to measure the degree of crosslinking within an epoxy specimen. These methods include chemical analysis and infrared and near infrared spectroscopy. They measure the extent to which the epoxy groups are consumed. Other methods are based on the measurements of properties that are directly or indirectly related to the extent and nature of crosslinks. These properties are the heat distortion temperature, glass transition temperature, hardness, electrical resistivity, degree of solvent swelling and dynamic mechanical properties, and thermal expansion rate. The methods of measurement are described in Chap. 20. 

Crystal field levels in rare earth metals have been determined by measurements of properties such as (i) specific heat, (ii) Van Vleck susceptibility, (iii) magnetization in high magnetic fields, (iv) paramagnetic resonance, (v) Mossbauer effect, (vi) inelastic neutron scattering and (vii) miscellaneous methods. 

In this chapter, we explore the current and potential future applications of AW devices for materials characterization and process monitoring. Because of the limited mass of material that can be applied to the AW device surface, the majority of these applications deal with the chemical and physical characterization of thin-film properties. This thin film focus should not be thought of as a limitation of AW devices, but rather as a useful capability — the direct measurement of properties of materials in thin-film form. Since material properties can depend on the physical form (e.g., film, bulk) of the material (see Section 4.3.1.3), AW devices are uniquely suited to directly characterize thin-film materials. These considerations also indicate that even though it is possible to use AW thin-film data to predict bulk material properties, such extrapolations should be performed with care. 

ACI Committee 544, Measurement of Properties of Fiber Reinforced Concrete, ACI Materials Journal, Proceedings, Nov.-Dec. 1988, 85 (6), 583-593. 

An important property of commuting operators is that there is a set of functions that are eigenfunctions for both operators simultaneously (for the demonstration see, for example, ref. 13). This means that a particular measurement of property Oi leading to an eigenvalue oi has also prepared the system to yield a particular value for the property O2 so that a measurement... 

Among the experimental methods established for the estimation of aromatic, or antiaromatic character, the most frequently employed are measures of properties that are related to sustained magnetic phenomena 39,42,139,148). These phenomena... 

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