Titanium absorption

Laser Photochemistry. Photochemical appHcations of lasers generally employ tunable lasers which can be tuned to a specific absorption resonance of an atom or molecule (see Photochemical technology). Examples include the tunable dye laser in the ultraviolet, visible, and near-infrared portions of the spectmm the titanium-doped sapphire, Tfsapphire, laser in the visible and near infrared optical parametric oscillators in the visible and infrared and Line-tunable carbon dioxide lasers, which can be tuned with a wavelength-selective element to any of a large number of closely spaced lines in the infrared near 10 ]lni. 

Analytical and Test Methods. o-Nitrotoluene can be analyzed for purity and isomer content by infrared spectroscopy with an accuracy of about 1%. -Nitrotoluene content can be estimated by the decomposition of the isomeric toluene diazonium chlorides because the ortho and meta isomers decompose more readily than the para isomer. A colorimetric method for determining the content of the various isomers is based on the color which forms when the mononitrotoluenes are dissolved in sulfuric acid (45). From the absorption of the sulfuric acid solution at 436 and 305 nm, the ortho and para isomer content can be deterrnined, and the meta isomer can be obtained by difference. However, this and other colorimetric methods are subject to possible interferences from other aromatic nitro compounds. A titrimetric method, based on the reduction of the nitro group with titanium(III) sulfate or chloride, can be used to determine mononitrotoluenes (32). Chromatographic methods, eg, gas chromatography or high pressure Hquid chromatography, are well suited for the deterrnination of mononitrotoluenes as well as its individual isomers. Freezing points are used commonly as indicators of purity of the various isomers. 

In galvanic coupling, titanium is usually the cathode metal and consequently not attacked. The galvanic potential in flowing seawater in relation to other metals is shown in Table 10. Because titanium is a cathode metal, hydrogen absorption may be of concern, as it occurs with titanium complexed to iron (38). 

Color Concentrates. Color concentrates have become the method of choice to incorporate colorants into resins. Color concentrates have high ratios of colorant to a compatible vehicle. The colorant may be added at 70% colorant to 30% vehicle in a titanium dioxide mixture whereas the ratio may be 15% colorant to 85% vehicle in a carbon black mixture. The amount of colorant that can be added is dependent on the surface area and the oil absorption of the colorant and the wetting abiHty of the vehicle. The normal goal is to get as much colorant in the concentrate as possible to obtain the greatest money value for the product. Furthermore, less added vehicle minimizes the effect on the physical or chemical properties of the resin system. 

The proposed mechanism includes the production of HCl from the pyro-hydrolysis of the metal chlorides. Similar reactions are likely for bromides and iodides. Fluorides however are relatively stable and would not be expected to hydrolyse. It was considered that this might account for the inability of fluorides to cause cracking. Hydrogen absorption by titanium alloys exposed to chloride salts at elevated temperatures has been detected and found to be proportional to the amount of moisture participating in the reaction. 

The McMuny coupling route has been utilised by Iwalsuki and co-workers the synthesis of PDBoxTV 85 (Scheme 1-29) [129]. Dialdehyde 90 is polynn ized in the presence of titanium tetrachloride and zinc dust. Molecular weights 35000 are reported and the polymer is freely soluble in solvents such as chloi form. The reported absorption maximum (605 nm) was close to that observed I the Blohm route [I27J. 

It has always been difficult to do quantitative work with the characteristic x-ray lines of elements below titanium in atomic number. These spectra are not easy to obtain at high intensity (8.4), and the long wavelength of the lines makes attenuation by absorption a serious problem (Table 2-1). The use of helium in the optical path has been very helpful. The design of special proportional counters, called gas-flow proportional counters,20 has made further progress possible, and it is now possible to use aluminum Ka (wavelength near 8 A) as an analytical line (8.10). 

Fradet227,232, in an esterification study on models, examined the reaction of octadecanoic acid with tetrabutoxytitanium. He found that a small amount of butyl octadecanoate is formed (absorption of the ester carbonyl at 1740 an-1) and that the carboxy absorption at 1710 cm-1 disappears completely. Simultaneously, two bands appear at 1560 and 1450 an-1, which is in agreement with Yoshino302. The ratio of the intensity of each of these two peaks to the intensity of ester peak (1740 cm-1) does not change when the concentration of the solution used in the spectroscopic study is varied consequently, the interaction between carbonyl and titanium is most probably intramolecular ... 

The variation in the lattice vibration of the solid products was examined by utilizing the FT-IR technique at successive DGC process times and the results are presented in Fig. 5. The absorption bands at 550 cm and 450 cm" are assigned to the vibration of the MFI-type zeolite and the internal vibration of tetrahedral inorganic atoms. The band 960 cm" has been assigned to the 0-Si stretching vibration associated with the incorporation of titanium species into silica lattice [4], This indicates that the amorphous wall of Ti-MCM-41 was transformed into the TS-1 structure. 

Titanium(III) chloride dissolves in water to give [Ti (H2 O). This complex ion has the absorption... 

Consider first blue sapphire Al203 Ti(III), Fe(III) (Fig. 2). In the absence of Fe(III) the absorption spectrum is easy to interpret. The weak band with a maximum at about 500 nm is due to the t2 —> e crystal-field transition on Ti(III) (3d ), the strong band at 2<280nm is due to a Ti(III)-0( — II) LMCT transition. The absorption band in the region around 700 nm in the case of the codoped crystal cannot be due to Fe(III). It has been ascribed to MMCT, i.e. to a transition within an iron-titanium pair ... 

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