Sample dimensions

For direct measurement from core samples, the samples are mounted in a holder and gas is flowed through the core. The pressure drop across the core and the flowrate are measured. Providing the gas viscosity (ji) and sample dimensions are known the permeability can be calculated using the Darcy equation shown below. 

These equations reveal that sample dimensions must also be known with precision, and, of course, the specimens must be free from defects. 

Sample preparation requirements in solid state NMR are strikingly simple because the measurement is carried out at ambient temperature and pressure. Wide-line NMR experiments can be carried out on solid samples in any form, as far as the sample dimensions fit those of the coil in the NMR probe. MAS experiments require the material to be uniformly distributed within the rotor. 

Energy to break. This is quoted usually in joules or in ftlbf. The result will only apply to one set of sample dimensions and it is not possible to allow for any change in specimen dimensions. 

Fig. 7. The Hall coeffieient (left seale) and conduetance (right seale) vs temperature. R was determined using the measured sample dimensions without any eorreetion.

The high explosives, baratol or Composition B-3, are used to produce the plane wave loading into the driver plates. These explosives have been widely studied in substantial work at Los Alamos. Plane waves are introduced into the explosive pads with either P-22 or P-40 plane-wave generators developed at Los Alamos. The Bear system is based on the 56 mm diameter of the P-22, while the larger sample size Bertha system is based on the 102 mmdiam of the P-40. More details on sample dimensions are reported by Graham [87G03]. 

Table 1. Bulk glass forming alloy systems and the produetion methods, d is the smallest sample dimension.

The new method (27) has a number of advantages in comparison to the original two-network method (10). Sample dimensions and the... 

SMALL MOLECULE PRODUCTS. The small molecule products from irradiation of polymers include hydrogen, alkanes and alkenes, CO and CO2, SO2, H2O and HC1 depending on the chemical composition of the polymer. They may be partly evolved and partly trapped in the polymer according to their volatility, the sample dimensions and the temperature. 

Molecular mixing via dynamic mechanical spectroscopy. While electron microscopy yields the phase size, shape, etc., as delineated above, dynamic mechanical spectroscopy (DMS) yields the composition within each phase. The DMS measurements employed a Rheovibron direct reading viscoelastometer model DDV-II (manufactured by Toyo Measuring Instruments Co., Ltd., Tokyo, Japan). The measurements were taken over a temperature range from -120°C to 140°C using a frequency of 110 Hz and a heating rate of about 1°C/ min. Sample dimensions were about 0.03 x 0.15 x 2 cms. 

Militz (1993) treated European beech with DMDHEU and evaluated the effectiveness of a variety of commercial catalysts. It was found that temperatures of 100 °C were necessary for effective curing of the resin. The ASE was calculated from the dimensions at 100 % RH in comparison to the sample dimensions at 30 % RH, rather than in a water-soak test, so that any possible effect of leaching was not determined. The highest ASE measured in this way was 75 %. The EMC of the treated samples was also determined and found to be higher than unmodified samples in all cases. 

Sample shape and size are of considerable importance when selecting dynamic test methods for solid propellants. Preparation must take account of surface conditions and precise dimensions. Usually cast specimens retain a polymer-rich surface layer and should be avoided. Additionally, the sample dimensions should be large compared with the size of the largest solid particle inclusion in the propellant. 

Deflection from strain gauge mounted on sample recorded against time, sample dimensions and mass. Time range extended by using time-temperature super-position E M E M... 

Samples for irradiation crosslinking were prepared by milling in the antioxidant, followed by compression molding. Sample dimensions were 6 X 7 X 0.083 inch. Details of the milling and compression molding procedures are given in Table II. 

Figure 26-40 Integrated biochip for DNA analysis of biological samples. Dimensions are 100 x 60 x 2 mm. Two bright circles are piezoelectric vibrators for ultrasonic agitation. 

The variation of the damping factor (tan 5) with temperature was measured using a Polymer Laboratories Dynamic Mechanical Thermal Analyzer (DMTA). The measurements were performed on the siloxanfe-modified epoxies over a temperature range of — 150° to 200 °C at a heating rate of 5 °C per minute and a frequency of 1 Hz. The sample dimensions were the same as those used for flexural modulus test specimens. 

Several points are to be noted. Firstly, pores and changes of sample dimension have been observed at and near interdiffusion zones [R. Busch, V. Ruth (1991)]. Pore formation is witness to a certain point defect supersaturation and indicates that sinks and sources for point defects are not sufficiently effective to maintain local defect equilibrium. Secondly, it is not necessary to assume a vacancy mechanism for atomic motion in order to invoke a Kirkendall effect. Finally, external observers would still see a marker movement (markers connected by lattice planes) in spite of bA = bB (no Kirkendall effect) if Vm depends on composition. The consequences of a variable molar volume for the determination of diffusion coefficients in binary systems have been thoroughly discussed (F. Sauer, V. Freise (1962) C. Wagner (1969) H. Schmalzried (1981)]. 

The concept of the coherence area may also be described as follows. Suppose one of the sample dimensions in the plane perpendicular to the sample-detector line is a. Then, the angular range of light accepted in that direction Aa must be on the order of... 

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