Method for measurement

The most oommon method for measuring formation resistivity and henoe determining hydrocarbon saturation is by logging with a resistivity tool such as the Laterolog. The tool is designed to force electrical current through the formation adjacent to the borehole... 

CT offers the opportunity to examine slices through the sample non-destructively and is therefor the only method for measuring exterior and also interior part coordinates without mechanical cutting of the object. 

As the cursor is moved over the rendered 3D data, the eo-ordinates and amplitude of the eell giving rise to the pixel under the cursor are displayed in the status bar. This provides a basic method for measuring the location and dimensions of flaws. However, it is more convenient and accurate to perform sizing operations on 2-dimensional slices, so several slicing and sizing tools are incorporated. 

This is a fairly accurate and convenient method for measuring the surface tension of a liquid-vapor or liquid-liquid interface. The procedure, in its simpli-est form, is to form drops of the liquid at the end of a tube, allowing them to fall into a container until enough have been collected to accurately determine the weight per drop. Recently developed computer-controlled devices track individual drop volumes to = 0.1 p [32]. 

Fig. IV-6. Vibrating electrode method for measuring surface potentials. (From Ref 1.)...

Meiboom S and Gill D 1958 Modified spin-echo method for measuring nuclear relaxation times Rev. Sci. Instrum. 29 688-91... 

By inserting a semiconductor x-ray detector into the analysis chamber, one can measure particle induced x-rays. The cross section for particle induced x-ray emission (PIXE) is much greater than that for Rutherford backscattering and PIXE is a fast and convenient method for measuring the identity of atomic species within... 

Two parameters must be measured to apply the BET equation, the pressure at the sample and the amount adsorbed at this pressure. There are tlnee conmron methods for measuring the amount of gas adsorbed, called the volumetric method, the gravimetric method and the dynamic method, of which the volumetric method is the connnonest [21],... 

Johansen C R, Nelson H M and Gardner J H 1968 Method for measuring magnetization to high pressures J. Appl. Phys. 39 2152... 

Bain A D and Duns G J 1994 Simultaneous determination of spin-lattioe (T1) and spin-spin (T2) relaxation times in NMR a robust and faoile method for measuring T2. Optimization and data analysis of the offset-saturation experiment J. Magn. Reson. A 109 56-64... 

Demidov A A and Ivanov I G 1989 Laser fluorometrio method for measuring the oonoentrations of ohiorophyll a and pheophytin a in aoetone solutions Biol. Bull. Acad. Sc/. USSR 16 228-34... 

The 1967 Nobel Prize in chemistry was shared by Manfred Eigen a German chemist who developed novel methods for measur ing the rates of very fast re actions such as proton transfers... 

Preparing a solution of known concentration is perhaps the most common activity in any analytical lab. The method for measuring out the solute and solvent depend on the desired concentration units, and how exact the solution s concentration needs to be known. Pipets and volumetric flasks are used when a solution s concentration must be exact graduated cylinders, beakers, and reagent bottles suffice when concentrations need only be approximate. Two methods for preparing solutions are described in this section. 

Ketkar and co-workers developed a new analytical method for measuring trace levels of atmospheric gases.The analysis of a sample containing 40.0 parts per thousand (ppt) 2-chloroethylsulfide yielded the following results... 

One method for measuring the temperature of the sea is to measure this ratio. Of course, if you were to do it now, you would take a thermometer and not a mass spectrometer. But how do you determine the temperature of the sea as it was 10,000 years ago The answer lies with tiny sea creatures called diatoms. These have shells made from calcium carbonate, itself derived from carbon dioxide in sea water. As the diatoms die, they fall to the sea floor and build a sediment of calcium carbonate. If a sample is taken from a layer of sediment 10,000 years old, the carbon dioxide can be released by addition of acid. If this carbon dioxide is put into a suitable mass spectrometer, the ratio of carbon isotopes can be measured accurately. From this value and the graph of solubilities of isotopic forms of carbon dioxide with temperature (Figure 46.5), a temperature can be extrapolated. This is the temperature of the sea during the time the diatoms were alive. To conduct such experiments in a significant manner, it is essential that the isotope abundance ratios be measured very accurately. 

The Poiseuille equation provides a method for measuring 77 by observing the time required for a liquid to flow through a capillary. The apparatus shown in Fig. 9.6 is an example of one of many different instruments designed to use this relationship. In such an experiment the time required for the meniscus to drop... 

The Measurement of There are two main methods for measuring the unsteady-state method, and the steady-state method. In the... 

Surface Area. Surface area is the available area of fillers, be it on the surface or in cracks, crevices, and pores. The values obtained from different methods for measuring the surface area of a filler may vary significandy. These variations are because of the nature of the methods and in many instances yield information related to the heterogeneity of the surface. Understanding the surface area is important because many processing factors are dependent on the surface area, eg, ease of filler dispersion, rheology, and optimum filler loading. 

Test Methods. There is no standard test method for measuring transmissibihty or isolation efficiency of vibration isolation devices. The most common procedure is to measure the vibration transmitted to the supporting stmcture with the isolators in place and with the equipment supported on rigid blocking. From these measurements the insertion loss in dB is deterrnined by the following where T is the transmitted vibration with isolators in place and is the transmitted vibration with rigid supports. 

Low temperature filtration (qv) is a common final refining step to remove paraffin wax in order to lower the pour point of the oil (14). As an alternative to traditional filtration aided by a propane or methyl ethyl ketone solvent, catalytic hydrodewaxing cracks the wax molecules which are then removed as lower boiling products. Finished lubricating oils are then made by blending these refined stocks to the desired viscosity, followed by introducing additives needed to provide the required performance. Table 3 Usts properties of typical commercial petroleum oils. Methods for measuring these properties are available from the ASTM (10). 

Phosphatase Test. The phosphatase [9001-78-9] test is a chemical method for measuring the efficiency of pasteurization. AH raw milk contains phosphatase and the thermal resistance of this enzyme is greater than that of pathogens over the range of time and temperature of heat treatments recognized for proper pasteurization. Phosphatase tests are based on the principle that alkaline phosphatase is able, under proper conditions of temperature and pH, to Hberate phenol [108-95-2] from a disodium phenyl phosphate substrate. The amount of Hberated phenol, which is proportional to the amount of enzyme present, is determined by the reaction of Hberated phenol with 2,6-dichloroquinone chloroimide and colorimetric measurement of the indophenol blue formed. Under-pasteurization as well as contamination of a properly pasteurized product with raw milk can be detected by this test. 

Fig. 15. Laboratory methods for measuring sohds suspension quahty (a) visual, and (b) light transmission.

Steels having adequate hardenabiHty develop martensitic stmctures in practical section sizes. Molybdenum is a potent contributor to hardenabiHty, and has been shown to be even more effective in the presence of carehiUy selected amounts of other alloying elements (26). The end-quench test has become the accepted method for measuring hardenabiHty, and the data can be correlated with section size. Technical societies worldwide have standardized hardenabiHty limits (bands) for a large number of carbon and alloy steels standards of the Society of Automotive Engineers are examples (27). 

Capillary Viscometers. Capillary flow measurement is a popular method for measuring viscosity (21,145,146) it is also the oldest. A Hquid drains or is forced through a fine-bore tube, and the viscosity is determined from the measured flow, appHed pressure, and tube dimensions. The basic equation is the Hagen-Poiseuike expression (eq. 17), where Tj is the viscosity, r the radius of the capillary, /S.p the pressure drop through the capillary, IV the volume of hquid that flows in time /, and U the length of the capillary. 

A method for measuring the uniaxial extensional viscosity of polymer soHds and melts uses a tensile tester in a Hquid oil bath to remove effects of gravity and provide temperature control cylindrical rods are used as specimens (218,219). The rod extmder may be part of the apparatus and may be combined with a device for clamping the extmded material (220). However, most of the mote recent versions use prepared rods, which are placed in the apparatus and heated to soften or melt the polymer (103,111,221—223). A constant stress or a constant strain rate is appHed, and the resultant extensional strain rate or stress, respectively, is measured. Similar techniques are used to study biaxial extension (101). 

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