Color natural

Portland cement is classified as a hydrauHc cement, ie, it sets or cures in the presence of water. The term Portland comes from its inventor, Joseph Aspdin, who in 1824 obtained a patent for the combination of materials referred to today as Portland cement. He named it after a grayish colored, natural limestone quarried on the Isle of Portland, which his cured mixture resembled. Other types of hydrauHc cements based on calcium materials were known for many centuries before this, going back to Roman times. Portland cement is not an exact composition but rather a range of compositions, which obtain the desired final properties. The compounds that make up Portland cements are calcium siHcates, calcium aluminates, and calcium aluminoferrites (see ). 

Rynatan pediatric suspension is an antihistamine/nasal decongestant combination available for oral administration as a suspension. Each 5 mL (one teaspoonful) of the slate-purple-colored, natural strawberry-artificial currant-flavored suspension contains phenylephrine tannate 5 mg, chlorpheniramine tannate 4.5 mg, benzoic... 

Quinoxaline-2,3-dithione, as reported earlier,1 is useful for its coordinating properties with transition metals. The metal complexes of the dithione with Cu, Ni, Zn, Pd, and Pt have been prepared,171 and the spectral properties of the Ni and Pd complexes examined.171,172 UV data indicate that quinoxaline-2,3-dithione (153) is present as such, rather than as 2,3-dimercaptoquinoxaline the highly colored nature of its complexes is attributed to charge transfer.171... 

Intensily colored (near 450 nm) complexes involving Ruthenium (154) and 1,8-naphthyridine and its more basic derivative, 2,7-dimethyl-1,8-naphthyridine, have recently been described.105 The highly colored nature of these complexes has been ascribed to metal-to-ligand charge transfer transitions. 

A composition of balsam ingredients is disclosed. It contains color, natural honey, milk, nut infusion, nut aromatic alcohol, sugar, Jerusalem artichoke infusion, black choke-berry juice, ashberry juice, St. John s wort, blackcurrant leaves, cherry leaves, echinacea, spiruline, pine (young sprouts), and a cinnamon infusion. 

Spinel is another simple oxide mineral. It is commonly seen today as a synthetic and may be any color. Natural red spinel was most prized as a gem, and usually was used as an imitation of ruby. Some notable pieces in the British and Russian crown jewels include large uncut spinels. These crystals are a deep red color and are distinctive because of their rough octahedral shape. 

Samples first were washed in water with manual agitation in a Buchner funnel and then were successively rinsed with methanol, chloroform, methanol, and water. During this process, particulate debris separated from the fibers, and it was assumed that loosely attached water-, methanol-, and chloroform-soluble impurities largely washed out with the filtrate. Preliminary extraction tests for the presence of synthetic dyes were conducted as follows Samples were first boiled in water. If the solution colored, the water extract was analyzed with HPLC, and the sample was then boiled in dilute ammonia. If the ammonia extracts were strongly colored (natural dyes with the exception of very few do not extract into water or dilute ammonia), they were shaken with zinc dust, and if the ammonia extract reduced to a completely colorless solution, it was concluded that the sample was an azo dye (I). Early synthetic dyes often bleed into boiling water, and azo groups will reduce in the presence of zinc dust. 

Ohver B. G., Thurman E. M., and Malcolm R. L. (1983) The contribution of humic substances to the acidity of colored natural waters. Geochim. Cosmochim. Acta 47, 2031-2035. 

After removal of the mobile phase from the developed plate by heating, zones are detected on the layer by their natural color, natural fluorescence, quenching of fluorescence, or as colored, UV-absorbing, or fluorescent zones after reaction with a reagent (postchroma-tographic derivatization). Zones with fluorescence or quench fluorescence are viewed in cabinets that incorporate shortwave (254 nm) and longwave (366 nm) UV lamps. 

Discoloration. Staining or discoloration of wood by chemical processes is a frequently encountered form of degradation. It is often confused with discoloration caused by fungi, but results instead from the conversion of originally colorless or light-colored, naturally occurring extractives into intensely colored products that may impart an objectionable appearance to the wood. 

The increasingly colored nature of our surroundings has meant increasing use of colorants. Since many colored materials contain at least some inorganic pigment, their demand has steadily increased. 

FIGURE 14.19 Depth profiles of Zn for all investigated cores. Please take notice of the equal depth scale (y axis) and the partly different scales for concentrations (x axis). The anthropogenic part of the total concentrations is dark gray colored (natural background subtracted). 

Zinc and acetic acid reduced the 1,4-naphthoquinone E into hydroquinone F with concomitant removal of the protective group. Ring closure of F was effected under the Mitsunobu conditions to give G. Barton s benzeneseleninic anhydride [(PhSe0)20] smoothly oxidized G to furnish (R)-ent-nocardione B (143 ) as dextrorotatory needles with orange color. Naturally occurring (—)-nocardione B (143) was therefore shown to possess (/ -configuration.35... 

Radical cations of saturated hydrocarbons have strong electronic absorptions in the visible and near-infrared region of the spectrum. The strongly colored nature of alkane radical cations is in striking contrast to neutral alkanes that absorb electronically only in the vacuum UV. The electronic absorption of alkane radical cations has been studied in the solid phase by matrix isolation using y-irradiation [1-3] and in the gas phase by ion cyclotron resonance (ICR) photodissociation in either the steady-state or pulsed mode of operation [4]. Both methods have their specific merits and drawbacks. A major concern in matrix isolation spectroscopy is spectral purity (because of the possible presence of other absorbing species) and... 

Vanillin/Sulfuric acid Dissolve vanillin (4 g) m concentrated H2SO4 (100 mL). Heat at 100°C until coloration appears. A imiversal spray. Many terpenes give red and blue colors. Natural products with little functionality may give poor coloration—try spray (2) Spray and heat in a fume cupboard. 

UV at 248 and 278 nm, and sets of narrow bands centered at about 488 and 615 nm (Mitchell et al. 1997) yielding a brick-red emission color. Natural samples of hydroxyl-apatite and fluorapatite show similar CL bands (Gaft et al. 1999). Time-resolved emission spectra (Fig. 19) show well defined Pr emission in natural magmatic apatite at 485 and 607 nm (Gaft et al. 1999). Studies using polarized emission measurements on this sample were interpreted as representative of only Cal site occupation by Pr (Reisfeld et al. 1996). In contrast, a sedimentary apatite annealed in air showed a different Pr spectrum, with a set of bands centered at about 630 nm (Fig. 19). This spectrum was interpreted to be due to Pr in Ca2 (Reisfeld et al. 1996). Pr appears to be an efficient sensitizer for Sm, as many of its transition energies are almost identical to Sm, and in general Pr probably is more important as a sensitizer of other REE than for its own emission (Mitchell et al. 1997). 

As discussed in previous sections, the indolo[2,3-fl]quinolizine ring exists in two resonance structures with the great contribution of zwitterionic form, evidenced by the colored nature and the high dipole moments of compounds of this type, as well as by their pH-dependent UV spectra. 6,7-Dihydro analogues, like the parent systems, can also be represented by the two mesomeric forms. Although these compounds are stable, they are readily protonated on the indole nitrogen atom and, in fact, these compounds are normally isolated and purified via their acid salts. 

Bourbonniere R.A., van Halderen T. (1989), Fractional precipitation of humic acid from colored natural waters. Water, Air, and Soil Pollution, 46,187-198. 

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