White zone

White zone A ventilation containment zone used in the atomic energy industry. 

Iron(III) thiocyanate is not formed to any extent in the chromatogram zones. The result is white zones on a pink-colored background ... 

The chromatogram is dried for 10 min in a stream of warm air and immersed in solution I for 1 s. It is then dried for 5 min in a stream of warm air and finally immersed in solution II for 1 s. White zones result on a pink background. 

The phosphates and phosphonic acids appeared as white zones on a pink background (Fig. 1 A). Figure 1B is a reproduction of the reflectance plots (X = 480 nm). Detection limits of 50 ng have been found for POl and PaOj". In the case of PsOl and P3O10 the detection limits were 125 ng per chromatogram zone. 

Note If a dipping solution was employed for detection whose concentration was reduced to 1/10th that given above the acids appeared as white zones on a light brown background. 

Note The color of the zones persists for a long period, but changes to blue-violet [1]. Rosaniline [1, 2] can be employed instead of fuchsin. With sugar alcohols lead(IV) acetate alone yields white zones on a brown background (detection limit 1 — 2 pg per chromatogram zone) [3]. 

Pink-colored chromatogram zones appeared on a blue background these rapidly changed color to white zones (Fig. 2B). 

Alkaloids produce pale yellow, pink, green, brown, blue or violet zones [23]. Urethanes blue-green to dark violet zones [36]. Thiols and penicillin derivatives appear immediately as white zones and sulfoxides only after a few minutes as yellow to yellowish-blue zones on a reddish background [37, 39], which becomes deep purple on spraying with water [37]. 

Carefully suck off the white zone located about 1 cm below the meniscus, combine the material from all tubes and dilute 1 2 with Soln. D. Spin at 60 000 x g for 45 min (e.g., Beckman Coulter Type 50.2Ti rotor 40 000 rpm). 

Fig. 10. Zonation of the Larderello geothermal field derived from (a) gas analyses, and (b) stable isotope values of steam produced before and after re-injection. Distribution and characterization of geothermal subunits obtained by gas analyses have been established from a data set collected before 1989, that is, 6 years after the beginning of re-injection of waste waters. White zones represent areas that produce gas mixtures with almost the same composition as that of the original gases emerging at the surface before the exploitation of the field (Scandiffio et al. 1995). Dashed zones produce steam affected by addition of cold water (i.e., re-injected) to the geothermal system. The zonation from the isotopes was derived from an extensive survey performed in 1992. In Fig. 10b, different sources of cold water are discriminated. Abbreviations LRD = Larderello, CN = Castelnuovo, MR = Monterotondo, SS = Sasso Pisano, LGR = Lagoni Rossi, SR = Serrazzano geothermal subunits.

Figure 10.7. Flame structure visualized by the indexed reaction rate. Black zones correspond to premixed flames and white zones to diffusion flames.

Let us first describe the tracking in the focal plane of the microscope objective. First, the chosen particle has to be selected by, for example, moving a cross on the screen. Its position is given by the barycenter of the white or black zone. To do so. after having found a first white pixel (three-level situation), a recursive algorithm must be applied to find the coordinates of all the other white pixels of the central zone. One thus obtains the position of the panicle at a time t. To determine its new position at time t + elt. we have to turn around on a spiral from the last position known until we find a new white pixel, and the analysis of the new white zone found will give the new position of the particle. Depending... 

Atenolol (hRt 25—30), bunitrolol hRt 40 — 45) and alprenolol (hRt 50—55) ap-peared as light blue to white zones on a yellow background in visible light. They... 

Figure 2-1. We consider a surface 5 drawn in a fluid that is modeled as a billiard-ball gas. Initially, when viewed at a macroscopic level, there is a discontinuity across the surface. The fluid above is white and the fluid below is black. The macroscopic (volume average) velocity is parallel to S so that u n — 0. Thus there is no transfer of black fluid to the white zone, or vice versa, because of the macroscopic motion u. At the molecular (billiard-ball) level, however, all of the molecules undergo a random motion (it is the average of this motion that we denote as u). This random motion produces no net transport of billiard balls across S when viewed at the macroscopic scale because u n = 0. However, it does produce a net flux of color. On average there is a net flux of black balls across S into the white region and vice versa. In a macroscopic theory designed to describe the transport of white and black fluid, this net flux would appear as a surface contribution and will be described in the theory as a diffusive flux. The presence of this flux would gradually smear the initial step change in color until eventually the average color on both sides of. S would be the same mixture of white and black.

Fig. 5.4. Schematic representation of three successive situations met in the course of an osmotic pressure measurement. The white zones in the cells represent the solvents that are able to cross the semi-permeable membrane. The grey zones represent the solution containing species that are unable to cross the membrane.

Fig. 8A In UV-365nni Gelsemii radix (1) shows a series of blue fluorescent zones in the R, range 0.05-0.7 witli tlie prominent blue white zone of sempervirine (Tl) directly above the start. Gelsemine (T2/- B R, 0.35) does not fluoresce.

A methanolic extraction of the drag (2) and an alkaloid enrichment (3) show in UV-365nm 4-6 blue huore.scent zones in the Rf range 0.25-0.55 with an additional yellow-white zone at R,- - 0.55 (phenol carboxylic acids,. sanguinarine, protoberberines) in sample 2. 

Fig. 2SA Aconiti tuber (1), Sabadillae semen (2), Lobeliae herba (3). Their major alkaloids are found in file R, range 0.6-0.65 as white zones against a grey-blue background. Aconiti tuber (1) aconitine/mesaconitine (Tl) and six minor zones (R, range 0.25-0.7) Sabadillae semen (2) veratrine (T2) and eight minor zones (R, 0.5-0.5.5/n,8).

Hemolytically active saponins are detected as white zones on a reddish background. Hemoly.sis may occur immediately, after allowing the TLC plate to stand or after drying the plate in a warm airstream. 

B Treatment with blood reagent reveals the white zones of aescin at R, — 0.45. The additional two weak hemolytic zones in test Tl at R, 0.6 are aescinoles (artefacts). 

B Primula add responds to blood reagent with hemolysis, seen as white zones (vis.). 

Saponariae albae radix (2). One broad, brownish-black band at Rf 0.05-0.1 is accompanied by five to six weak violet zones between R( 0.15 and 0.4 —>A). All react with blood reagent to give white zones —>B). 

Detection of saponins white zones are formed against the reddish background of the plate. Hemolysis maybe immediate or may occur when the plate has been dried under slight wanning. 

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