Boule studies

The phototransformation of aqueous 2-chloroaniline was studied by Oth-men and Boule by means of product analysis [47] these authors later deepened and extended their work, including also 2-fluoro- and 2-bromo-aniline [48]. The range of photodegradation quantum yields was

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The data that have accumulated so far are summarized and discussed in several excellent reviews. Of those, information on the impact of sunlight on aquatic nitrogen compounds can be found in Bronk (2002), Kieber (2000), Mopper and Kieber (2002), Moran and Covert (2003), and Zepp (2003). A reader interested in mechanisms behind the reported phenomena is advised to turn to more chemistry-oriented works by Boule et ah (1999) and Mopper and Kieber (2000). The present chapter is a supplement and update of the above-mentioned studies, specifically focusing on phototransformations of dissolved organic nitrogen (DON). 

Carbene formation was mentioned in an earlier section. This elimination of HCl from 4-chlorophenol or elimination of other hydrogen halides from halophenols could have been inferred from earlier photochemical studies on this and other derivatives. Boule and his coworkers irradiated 4-chlorophenol under deoxygenated conditions and obtained the corresponding quinhydrone and the 2,4 -dihydroxy-5-chlorobiphenyl °. Other research demonstrated that its irradiation in neutral aqueous solutions gave the corresponding quinone " and also that de-aeration did not seem to affect the reaction. ... 

Different kinds of anthropogenic compounds and their occurrence within the non-extractable matter are reported in a couple of studies. Most of the investigations are related to the occurrence and fate of associated low molecular contaminants, the so called "bound residues", and are published within the last 30 years (e.g. Li and Felbeck 1972 Kaufman et al. 1976 Liechtenstein et al. 1977 Wheeler et al. 1979 Liechtenstein 1980 Khan 1982, Boul et al. 1994 Lichtfouse 1997 Houot et al. 1997 Northcott and Jones 2000). Earlier investigations dealed especially with... 

In 1978, Tairov and Tsvetkov [24] reported a sublimation technique to produce SiC boules for device application. They produced an 8 mm diameter by 8 mm long boule of SiC on a seed crystal placed within a graphite crucible. In a further study, growth of SiC boules up to 14 mm diameter and 18 mm in length were obtained [15]. 

The aqueous photochemistry of simple chlorinated benzenes has been studied by only a few authors. The sunlight extinction of chlorobenzenes is quite low (8297 for PhCl = 0.12 [Dulin et al., 1986]), and their solubilities (especially for the more highly chlorinated isomers) are also relatively low. Chlorobenzene triplets appear to react by homolysis to phenyl radicals and chlorine atoms the subsequent fate of these radicals depends on the solvent used. Dulin et al. (1986) and Boule et al. (1987) indicated that monochlorobenzene was photohydrolyzed to phenol with a quantum yield of about 0.1 to 0.5. Additional very polar products were also observed, but no benzene. These quantum yields are similar to those observed in organic solvents however, the principal fate of photolyzed chlorobenzenes in organic solvents is reduction by hydrogen donation. Dichloro- and trichlorobenzenes were similarly converted to monochloro- and dichlorophenols, respectively, in water. The quantum efficiency for trichlorobenzene photodestruction in 10% acetonitrile was about 0.03 (Choudhry and Hutzinger, 1984). 

Atomically resolved STM studies require preparation of a flat surface with well-defined crystallography. Studies to date have focused on either singlethin film noble metal electrodes. The haditional approach to single-crystal preparation involves growing an ingot or boule by solidification from a melt using a seed crystal to control the orientation. Alternatively, a remarkably simple and inexpensive technique has been developed whereby a H2-O2 flame is used to melt the end of a polycrystalline... 

Collection of rigid plastic containers (RPC) shows that there is a large constituent beside milk and soda bottles which will be deposited in a recycling bin. A study of the Sayerville, NJ curbside collection program, where plastics accepted included "any plastic bottle or container from which a product is pouted," shows HOPE that would be collected in addition to only milk and water boules (Table 2.5). 

Grain boundary groove formation was studied on three different aluminum oxide materials. The first, from the Linde Division of Union Carbide Corporation, was a sapphire boule which contained a number of lineage boundaries. X-ray analysis indicated that the c axis was about 55° from the boule axis. The misorientations across the lineage boundaries were a maximum of about T of tilt between grains. Small samples were cut from the boule and surfaces perpendicular to the boule axis were polished for thermal grooving. 

The emission properties of nonpolar a-plane AlN and InN films grown on r-plane sapphire are the least explored. Only a few papers present the initial data on this topic. The NBE emissions were confirmed very close to that in polar AlN [103,104] and InN [38,105] materials with no detailed studies of the effect of strain on them. Significant improvement of the emission intensity was observed in nonpolar AlN [104] as a result of microstructure improvement in case of ELOG [104] or Pendeo [106] template employment. Similar to the observation for GaN, the AlN bulk material with nonpolar orientations sliced from boules grown in the [0001] direction was found to possess superior emission quality [103]. 

A. de S. Dupin, and A. Boule, 1965. Study by infrared spectroscopy and by nuclear magnetic... 

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