Black zone

Chalcones yield orange-red to brown-colored zones [4] as do 4-aminoazobenzene derivatives, but their colors begin to change after 10 min and slowly fade [5]. Penicillic acid is visible as a greyish-black zone [18]. 

FIGURE 6.20 Sample application using preparative circular planar chromatographic device (the black zones symbolize the applied sample) (a) liquid phase sample application, (b) solid phase application into the center hole of the plate, (c) solid phase sample application into a scrapped channel. (From Botz, L., Nyiredy, Sz., and Sticher, O., J. Planar Chromatogr. 3, 401-406, 1990. With permission.)... 

Fig. 6 Schematic drawing of ZSM5 catalyst bed deactivation. View of the fused silica reaction tube at about 40 % of catalyst life time. Black zone (I) of deactivated catalyst particles covered with coke ("methanol coke"). Small dark reaction zone (II) in which methanol conversion to 100 % occurs. Blue/grey zone (III) of active catalyst on which a small amount of "olefin coke" produced by the olefinic hydrocarbon product mixture has been deposited on the crystallite surfaces. The quartz particles before and behind the catalyst bed (zones 0) remain essentially white.

Fig. 5.7 (a) Statue belonging to the group Les bourgeois de Calais (A. Rodin, cast by A. Rudier, Paris, 1920)—notice on the two arms the vertical lines that follow the rain runoff (b) Detail showing some black zones (squares in relief) that correspond to the original surface covered by the atmospheric deposit, middle in the corroded and eroded surface... 

Fig. 12. Comparison of amino acid sequences of bovine and rat a s as deduced from their respective cDNAs. The long boxes represent the two polypeptide chains, and the two black zones the stretches of amino acids involved in guanine nucleotide binding. The locations of amino acids that differ, identified above and below, are denoted by lines connecting the two polypeptide chains. Note that 75% of the differences are in the region proposed by Bourne and collaborators [ 176] as interacting with the effector.

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... 

Delivery temperatures of 264 °C and 350 °C were used to give films 1 and 2, respectively. In the formation of film 2 with a delivery temperature of 350 °C, premature precursor decomposition was observed in the delivery zone. Deposition temperature was also found to be a very important factor. The deposition at 300 °C gave a much thinner film. Films 1 and 2 deposited at 448-450 °C had a gold color and a dark blue black zone, reflecting some bluish gray light. Under the same conditions, films deposited on quartz substrates below 450 °C had very different appearances compared to those grown on a Si(lOO) wafer. They were very thin, transparent and quite yellow. 

Figure 26-5 649 Specular reflection illumination reveals the honeycomb appearance of the normal cornea and the black zones in the endothelium caused by guttata arrow). (B) TransiUumination revealing orange-peel dimpling characteristic of central corneal guttata arrow). (Courtesy of Pat Caroline.)...

Calothrix is a genus of cyanobacteria that produces what is known as the black zone, a line of black, tarlike blobs, in the high intertidal zone. Each globule is a colony of cyanobacterial cells. These colonies can endure extended periods without water because they are contained in gel-like sheaths that keep them moist. Calothrix also grows like a crust on rocks and on other types of algae in many intertidal regions. 

Note Dark brown-black zones in the i , range 0.05-0.2 are due to free sugars. 

Besides cardenolides zones (R, 0.4-0.6), Adonidis herba (1) generates various other compounds reacting to SbCI, with intense dark-blue colours (vis.) and as dark, almost black zones in UV-365 nm. The cardenolides are seen as grey-blue or brown-green zones (vi.s) and as intense light-blue fluorescent zones (UV-365nm), mainly in the R, range 0,43-0.75. 

Saponariae rubrae radix (3). Beside.s two main brownish-black zones at R, 0.05-0.1,... 

Fig. 7.1. Evolution of the system of intercellular communication by cAMP signals in D. discoideum in the course of development. Time is measured in hours after the beginning of starvation. The black zone at the bottom of the figure shows the evolution of the basal activity of adenylate cyclase. Until 2 h after the beginning of starvation, the enzyme fails to be activated by cAMP signals the transient activation, corresponding to the phenomenon of relay, is observed thereafter, followed by the onset of autonomous oscillations of cAMP. The latter spontaneously appear about 4 h after the beginning of starvation and continue for about 3 h, before the system recovers its excitable behaviour (Gerisch et a/.,1979).

Figure 23.1. Network-like superstructure of a surfactant film of cetyltrimethylammonium bromide (c = 6 x 10 mol/1). The cross-linking process between the molecules was induced by adding multivalent counterions such as cerium sulfate c = 10 mol/1). The Brewster-angle image was obtained during the adsorption process of the amphiphilic molecules and represents the situation near the sol-gel transition, where the first infinite large clusters were formed. Black zones represent the pure water surface, while clear areas correspond to the presence of surfactant clusters...

Predominance-Zone Diagrams for Chemical Species, Fig. 2 Pourbaix-type diagram of americium species at —logfSOy] = 0.523 in the Eh/pH space, constructed with the MGSE. SO4 = HS04 + SO4 . Dashed black zones represent the coexistence of condensed phases for... 

Fig. 2 SEM images of porous NCs with 6.4 wt% of (a) 3 nm and (b) 10 nm nanoparticles. Black zones represent pores surrounded by white polymCT walls, (c) Image of a porous NC attracted to a magnet. SEM images were taken with a Hitachi TM-1000 instrument...

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