Ruby scale

The linear calibration of the ruby fluorescence emission, initially based on the equation of state of sodium cloride [71, 89, 96, 103, 237], is reliable up to 30 GPa for a quasi-hydrostatic environment. The quasi-hydrostatic calibration was extended up to 80 GPa [157], and a slight nonlinearity of the calibration curve at high pressure was found. Calibration of the ruby scale against primary... 

Pressure calibration is necessary in pressure work, and this is accomplished by incorporating a small ruby crystal with the sample under study. The Ruby scale (4) was developed by the National Bureau of Standards (now the NIST) in 1972, and the sharp Ruby Ri fluorescent line has been calibrated vs. pressure by NIST, and is suitable even up to megabar pressures (5). 

Further details on the Ruby scale are provided in the following section on instrumentation. 

Calibration of the pressure is best accomplished using the Ruby scale. Generally this is done using a metal gasket between the two diamond windows surrounding the sample in which a liquid (such as Nujol or Teflon oil) is added to produce hydrostatic pressure. The technique measures the pressure dependence of the sharp Ruby Ri fluorescence transition at 692.8 nm, although the R2 band at 694.2 nm can also be used. The Ruby fluorescence is induced by the blue excitation of the Ar+ (488.0 nm) or the He- C d (441.6nm) lasers. 

The high pressure cell was a classical Block-Piermarini diamond anvil cell, cryo-genically loaded with Kr. The pressure was measured using the power 5 law ruby scale [31]. Because of the small size of the sample in the cell, 300 pm in diameter, only a part of the beam is usable. 

P.R.ll has largely been replaced by other products. Its hue is a bluish red which resembles the color of ruby P.R.ll is more bluish than its positional isomer P.R.7. Both pigments behave similarly as far as fastness properties are concerned, which includes fastness to most of the solvents that are used in paints and printing inks, fastness to overlacquering, heat stability, and others. However, P.R.ll is much less lightfast than P.R.7 incorporated in medium-oil alkyd systems at 1/3 SD, P.R.ll scores 2 steps less on the Blue Scale (step 4). 

Perlow and Ruby (31) and Ramma Reddy, Barros, and De Benedetti (2, 32) have compared the isomer shifts of a set of compounds with the isomer shifts from an identical set of compounds. This procedure allowed removal of the calculated values of the electronic densities of the compounds. The two isomer shift scales were linearly related by a constant factor, and thus they did not observe any noticeable effect of the valence state of the electronic cloud on the nuclear matter. Ramma Reddy, Barros, and De Benedetti (32) obtained ... 

P. M. Bell and H. K. Mao, Static compression of gold and copper and calibration of the ruby pressure scale to pressures to 1.8 megabars by x-ray diffraction, in Shock Waves in Condensed Matter, Y. Gupta, ed., Plenum, New York, 1986, pp. 125-130. 

Figure 5.1 Two-dimensional electrophoresis separates potato proteins based on their isoelectric points and molecular weights. Using a wide-scale pH gradient and large gels, 1000-2000 quantifiable proteins can be separated. The gel stained with SYPRO Rubi shows soluble tuber proteins of potato cultivar Sante.

It crystallises in tabular hexagonal scales belonging to the hexagonal system, and possesses a steel-like lustre. The edges are ruby-red in colour, and give a red streak. Density, 5-187 to 5-193.4... 

Long, upright, sexangular white Fluors in a grey flint, partly covered with very small scales of different colour, mud-colour, ruby, ashen, black, and which are sprinkled with grains of gold-coloured pyrites. 

Cap 15-42 mm broad, occasionally larger sizes up to 20 cm in diameter. Flesh thin, broadly convex without an umbo. Evenly covered with pointy scales, purplish to ruby on yellow background, dry. Margin inrolled at first. 

Vos WL, Schouten JA (1991) On the temperature correction to the ruby pressure scale. J Appl Phys 69 6744-6746... 

The wine was scored using a modification of the descriptive analysis outlined by Stone et al. (12). Each major category of color, odor and taste was evaluated separately. For each attribute, a horizontal scale of 10 cm was provided with at least three labeled anchor points, one at each end and in the middle. Stage of color development was rated using descriptors red purple, ruby-red, ruby, ruby with amber highlights, amber and brown. 

Since diamond is transparent to visible light, the easiest method of measuring the pressure is with the ruby-fluorescence (Al203 Cr ) scale. The fluorescence associated with the Rj and R2 transitions of the ion around 14400 cm at ambient pressure shifts by —7.57 cm GPa under pressure, and pressure variations of —100 GPa can be measured with a modest spectrometer. Excitation-argon-laser powers of —10 mW are sufficient to obtain measurable signals from ruby chips with a volume of —1000 (cm. A chromium content in the ruby of anywhere between 500 and 5000 p.p.m. 

---