Color origin

The Copycolor films are peel-apart materials having chemistry similar to that of the Agfachrome-Speed process (Fig. 18). The Copycolor process provides color prints or transparencies from positive color originals. Processing in a Copyproof processor takes from 40 s to 3 min, depending on the specific materials used and the temperature. 

If hot sulfur melts or hot sulfur vapors at low pressure are frozen at low temperatures highly colored samples are obtained which may be black, green or red depending on the temperature and pressure conditions and on the rate of quenching [69]. These colors originate from the small molecules and radicals, present at high temperatures, which become trapped in the solid sample. At room temperature these samples turn yellow, provided the sulfur has been very pure. 

It was not until the nineteenth century that artists began to purchase ready-made commercial paints. Today paint colors have standardized specifications. Regardless of type, paint still consists of pigment and binder, as it has for centuries. Many colors originally produced from natural pigments are now made synthetically. The metal paint tube was developed in 1841. Paints that for centuries had been mixed and stored by the artist in various ways in the studio were suddenly available in an easily portable container. Artists who had found it difficult to paint on location were able to create many masterpieces outdoors, on location, as a result of tube paint becoming available. 

Considering the thickness 8s of such a source (Fig. 7-5b), then one gets the amount of substance contained in the cross section of the bar, c0 8s, because it has the unit surface area. One obtains the expression for the concentration cs of the color originating from this source at a distance s at time t according to Eq. (7-22) ... 

Metal nanoparticles have been used for many applications because of their unique characteristics, even before they were visualized as small particles of nano-meter order by using a transmission electron microscope [118]. For example, colored glasses, which gained in popularity in medieval times, contain nanoparticles of noble metals. These colors originate from the SPR of metal nanoparticles, which is the resonance phenomenon of surface electron density wave with incident light wave at the metal surface [119]. Since this resonance is sensitive to the dielectric constant of surrounding media, the phenomenon has... 

Do not submit color prints to be reproduced in black and white. Use a professional photo lab to prepare B W prints from color originals because photo labs use special paper to make B W prints from color originals. 

Group IV derivatives of triazene and organyltriazenes are sometimes obtained colorless, sometimes yellow to red (Table I). The pure compounds are actually colorless except for triazenes of type X3E—N=N—Nc (E = Si, Ge). The color originates from traces of impurities (azo compounds), which are difficult to remove. Triazenes studied by UV spectroscopy show an intense absorption band at... 

Color derivatizations can be broadly divided between reversible and irreversible reactions. Reversible reactions typically involve some kind of complex formation equilibrium. The color originates on the host and is imparted to the analyte on the formation of the complex. The combination of chirality and absorbance that produces CD activity is limited to only the complex. Any absorbance by uncomplexed host or any residual chirality on the imcomplexed analyte is not detected and are therefore not interfering. Because these are equilibrium reactions, the correlation between the experimental elliptically and the analyte... 

Relatively weak absorptions at wavelengths above 400 mn are snfficient to cause the perception of color. The color of woody tissue varies widely from off-white (e.g., aspen, birch), yellow (e.g., spruce, pine, fir), amber-orange (e.g., western hemlock, Douglas fir, red cedar, teak) and rich browns (walnnt). While some of this color is dne to tannins and other extractives, in most species the color originates from chromophores in the lignin. 

Side of Trailer — A strip of sheeting or reflex reflectors must be applied horizontally (in alternating colors) originating and terminating as close to the front and rear as practicable. The sheeting or reflex reflectors must be placed not less than 15 inches (375 mm) and and not more than 60 inches (1,525 mm) above the road surface at the strip s centerline with the trailer at curb weight. 

Fig. 1 Dendritic core-shell star polymers, (a) Dendritic core-shell star polymers of different architectures with varying densities of the polycationic polymer chains grafted from the dendrimer core as well as varying numbers of positive charges along the individual polymer chains, (b) Cellular uptake of selected macromolecules by ECV-304. The bars represent relative fluorescence units (RFU) measmed in individual cells. Data represent mean values ( SEM after an incubation periods of 6 and 24 h. (c) Cell uptake of polycationic core-shell dendrimers into ECV-304 cells after 15 min. ECV-304 were stained using a green fluorescence cell tracker, whereas the core-shell macromolecules are shown with a red color originating from the PDI core...

Fig. M-27. Indians drying and smoking venison. (Photo from a water-color original by Ernest Smith. Owned by the Rochester Museum of Arts and Sciences)...

The above discussion is fully relevant to these impurities, because the color originates, mainly, from their presence. 

Anyone who has shared the company of three-year old children for an afternoon will recognize the conversation. Everything you say is challenged immediately with their favorite word— why Newly arrived in the world and fascinated by aU they see, three-year olds want to know the why of everything. They live in a world of mystery, wonder, and possibility— where magic is real and reality is magic. As we explore the discovery of the physics of color origin and perception, put yourself in the place of the three-year old who always wants to know why. Or put yourself in the place of the discoverers themselves who must have been filled with awe at what they learned and communicated to the world for the first time. 

To easily visualize these zones, the nebulization of a solution of yttrium (about 1 mg/L concentration) can be used as an indicator. The bright red color of the central cone defines the IRZ. The red color originates from the atomic emission of Y atoms excited by the plasma. Above the IRZ is a bright blue bullet, which defines the NAZ. This color is due to excited Y ions, which emit blue visible radiation. If the plasma and sample introduction system are performing satisfactorily, these colored zones should be well defined and reproducible. The use of this... 

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