Quartz standard

A pure quartz standard is best obtained by grinding a clear quartz crystal. The quartz crystal can be identified by its characteristic form and interfacial angles according to Stenos law (21). Quartz crystals can be obtained from Ward Scientific (22), or other reputable supplier of mineral specimens. Data on siTTca minerals is given by Fronde 1 (23). 

Reiss has introduced a notation for combining the four microscopic variants of WRBS with field definitions defined by the m value. It might be preferable to keep the macroscopic adjustments separate from the molecular definitions. The question of the definition of the fields is related to the nature of the EFISH measurement. The essential observation is of the ratio between the intensity of second harmonic light emitted from the solution to that emitted by quartz standard. However the or-field is defined the ratio will be related to T by an equation (written schematically) of the kind,... 

In columns B the results of columns A have been adjusted by factors required to relate them to a uniform standard based on that currently preferred for the reference standards. In comparing ab initio and DFT calculations with experiment most authors have adopted a revised value for the quartz dn coefficient which is reduced by a factor of 0.6 from that used in earlier work. The results of Teng and Garito and Burland et al. in column B have simply been altered by this factor. Bosshard et al. give an unusual value for quartz which is (0.4/0.5) times the older (ql) figure. This factor has been removed before converting to the new quartz standard. 

Focussing on the first four lines of the Table 4, all of which are calibrated with the quartz standard, and can be adjusted to the same value for this standard, it is apparent that there is reasonably good agreement between the three determinations of the macroscopic nonlinearity of MNA. This consistency, taken in conjunction with the equations as written in the papers, leads to the conclusion that, with a reasonable degree of certainty, the provisionally defined quantity, F can be identified with the F of eqn (4.16). Having made this assumption, it follows that any differences in reported values that are not proportional to the small percentage differences in the F values must be the result of variations in the method employed to convert macroscopic to molecular parameters. This question is examined in the next section. 

The convention used by Levine and Bethea to define the response functions omits the Taylor series factors in the series for the induced dipoles but includes a factor of (3/2) implicitly in the definition of the macroscopic quantity. Their ft is equivalent to jl,. Hence to relate their results to the more usual conventions, the /i-value must be multiplied by 4 x (3/2) x (3/5) = 18/5 and the y value by 4 x (3/2) = 6. Finally a factor (0.30/0.335) must be applied to allow for the change in the quartz standard. Carrying out these operations and converting to atomic units gives the values in Table 10. 

Table 10 Experimental hyperpolarizabilities of H20 in the gas and liquid phases. The earlier result of Ward and Miller has been rescaled by Shelton and Rice to allow for the change in the quartz standard...

The tensor component magnitudes for quartz are well characterized for an incident laser beam near the fundamental wavelength of 1064 nm [27J. The X333(2, tensor component for quartz is an accepted standard [28]. As the quartz standard is rotated about the optic axis of the crystal, the maximum of the largest Maker fringe is found near normal incidence of the incident laser beam and used as a measure of for quartz. 

Fig. II-ll Ratio of the stopping power of the sample to the stopping power of a quartz standard as a function of the helium-3 energy...

Table 11-4 Percent error on the determination of 0 in Al, V, Zr and Pb using a quartz standard, when inaccurate excitation function...

Interplanar Spacings. Diffractometer alignment procedures require the use of a well-prepared polycrystalline specimen. Two standard samples found to be suitable are silicon and a-quartz (including Novaculite). The 26 values of several of the most intense reflections for these materials are listed in Table 7.6 (Tables of Interplanar Spacings d vs. Diffraction Angle 26 for Selected Targets, Picker Nuclear, White Plains, N.Y., 1966). To convert to d for Ka or to d for Ka2, multiply the tabulated d value (Table 7.6) for Ka by the factor given below ... 

HR-ICP-MS EEEMENT-2 (Pinnigan MAT, Germany) equipped with a standard introduction system (quartz water-cooled spray chamber, concentric nebulizer, torch with 1.5 mm i.d. injector and nickel cones) was used for measurements. The following operating conditions were used RP power 1150 W, coolant gas flow rate 16 1 min k auxiliary gas flow rate 0.85 1 min nebulizer gas flow rate 1.2 1 min k Sample uptake rate was 0.8-1 ml min k Measurements were performed with low and middle resolutions. Rh was used as an internal standard. Por calibration working standard solutions were prepared by diluting the multielemental stock solutions CPMS (SPEX, USA) with water to concentration range from 5 ng to 5 p.g I k... 

The particles most likely to cause adverse health effects are the fine particulates, in particular, particles smaller than 10 p and 2.5 mm in aerodynamic diameter, respectively. They are sampled using (a) a high-volume sampler with a size-selective inlet using a quartz filter or (b) a dichotomous sampler that operates at a slower flow rate, separating on a Teflon filter particles smaller than 2.5 mm and sizes between 2.5 mm and 10 mm. No generally accepted conversion method exists between TSP and PM,o, which may constitute between 40% and 70% of TSP. In 1987, the USEPA switched its air quality standards from TSP to PMk,. PM,q standards have also been adopted in, for example, Brazil, Japan, and the Philippines. In light of the emerging evidence on the health impacts of fine particulates, the USEPA has proposed that U.S. ambient standards for airborne particulates be defined in terms of fine particulate matter. 

The ramp of pressure to about 3 GPa observed in shock-loaded fused quartz has been used very effectively in acceleration-pulse loading studies of viscoelastic responses of polymers by Schuler and co-workers. The loading rates obtained at various thicknesses of fused quartz have been accurately characterized and data are summarized in Fig. 3.6. At higher peak pressures there are no precise standard materials to produce ramp loadings, but materials such as the ceramic pyroceram have been effectively employed. (See the description of the piezoelectric polymer in Chap. 5.)... 

Fig. 3.6. The accelerations achieved at low pressure with waves transmitted through various thicknesses of fused quartz (GE 151 and Dynasil 1000) have been carefully studied and can serve as standard loadings (after Graham [79G02]). Recent data from Smith [92S01] also show the particle velocity limit for the linear acceleration to be 0.11 kms ...

The piezoelectric behavior of both quartz and lithium niobate has been studied in a series of careful, systematic investigations. (See Graham and coworkers [65G01, 70101, 75G04].) The experimental arrangement is shown Fig. 4.2. The impactor, preferably the same material as the piezoelectric sample (but perhaps another standard material), is accelerated to a preselected... 

Fig. 5.5. The electrical response of piezoelectric polymers under shock loading is studied experimentally by placing the thin PVDF element on the impact surface of a standard target, either the polymer, Kel F, z-cut quartz, or z-cut sapphire. The im-pactor is typically of the same material. The current pulse is recorded on transient digitizers with frequency responses from 250 to 1000 MHz.

Due to the above requirements, typical optically-transparent materials, such as oxides (glass, quartz, alumina, zirconium oxide etc.) and halides (sodium chloride, lithium fluoride, calcium fluoride, potassium bromide, cesium bromide etc.) are usually unsuitable for use with fluoride melts. Therefore, no standard procedure exists at present for the spectral investigation of fluoride melts, and an original apparatus must be created especially for each particular case. 

QCMB RAM SBR SEI SEM SERS SFL SHE SLI SNIFTIRS quartz crystal microbalance rechargeable alkaline manganese dioxide-zinc styrene-butadiene rubber solid electrolyte interphase scanning electron microscopy surface enhanced Raman spectroscopy sulfolane-based electrolyte standard hydrogen electrode starter-light-ignition subtractively normalized interfacial Fourier transform infrared... 

POL The value determined by direct or single polarization of the normal weight of a sugar product or process stream in a polarimeter (saccharimeter). The normal weight (26 g in a 100-mL aqueous solution) of pure sucrose reads 100% or 100° pol in a polarimeter calibrated for sucrose measurement with a standard quartz plate. 

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