Detection and characterization

Process Integrated Detection and Characterization of Casting Defects. 

One interesting new field in the area of optical spectroscopy is near-field scaiming optical microscopy, a teclmique that allows for the imaging of surfaces down to sub-micron resolution and for the detection and characterization of single molecules [, M]- Wlien applied to the study of surfaces, this approach is capable of identifying individual adsorbates, as in the case of oxazine molecules dispersed on a polymer film, illustrated in figure Bl.22,11 [82], Absorption and emission spectra of individual molecules can be obtamed with this teclmique as well, and time-dependent measurements can be used to follow the dynamics of surface processes. 

Zander C, Sauer M, Drexhage K H, Ko D-S, Schulz A, Wolfrun J, Brand L, Eggeling C and Seidel CAM 1996 Detection and characterization of single molecules in aqueous solution Appl. Phys. B 63 517-23... 

Nondestmctive evaluation, also termed nondestmctive testing or nondestmctive inspection, is extensively used in weld testing (14). Nondestmctive tests do no impair the serviceabiUty of the material or component under stress. The most widely used tests for evaluation of welds are Hquid penetrant, magnetic particle, ultrasonics, and radiography. Acoustic-emission tests are increasingly used. Nondestmctive tests detect and characterize, in terms of size, shape, and location, the various types of weld discontinuities that can occur. 

Nitrophenyl groups covalently bonded to classy carbon and graphite surfaces have been detected and characterized by unenhanced Raman spectroscopy in combination with voltammetry and XPS [4.292]. Difference spectra from glassy carbon with and without nitrophenyl modification contained several Raman bands from the nitrophenyl group with a comparatively large signal-to-noise ratio (Fig. 4.58). Electrochemical modification of the adsorbed monolayer was observed spectrally, because this led to clear changes in the Raman spectrum. 

In addition to the stable I2O5 and moderately stable I4O9 and I2O4, several short-lived radicals have been detected and characterized during y-radiolysis and flash photolysis of iodates in aqueous alkali ... 

Azepine (m/z 93) was first detected and characterized by application of GC/MS techniques to the thermolysis products of 3-[hydroxy(diphenyl)methyl]-3//-azepine.91... 

With nondestructive ultrasonic test back and forth scanning of a specimen is accomplished with ultrasonics. This NDT can be used to find voids, delaminations, defects in fiber distribution, etc. In ultrasonic testing the sound waves from a high frequency ultrasonic transducer are beamed into a material. Discontinuities in the material interrupt the sound beam and reflect the energy back to the transducer, providing data that can be used to detect and characterize flaws. It can locate internal flaws or structural discontinuities by the use of high frequency reflection or attenuation (ultrasonic beam). 

In studies of molecular dynamics, lasers of very short pulse lengths allow investigation by laser-induced fluorescence of chemical processes that occur in a picosecond time frame. This time period is much less than the lifetimes of any transient species that could last long enough to yield a measurable vibrational spectrum. Such measurements go beyond simple detection and characterization of transient species. They yield details never before available of the time behavior of species in fast reactions, such as temporal and spatial redistribution of initially localized energy in excited molecules. Laser-induced fluorescence characterizes the molecular species that have formed, their internal energy distributions, and their lifetimes. 

Basta T, A Keck, J Klein, A Stolz (2004) Detection and characterization of conjugative plasmids in xenobiotic-degrading Sphingomonas strains. J Bacteriol 186 3862-3872. 

Kreiss M, J Eberspacher, F Lingens (1981) Detection and characterization of plasmids in Chloridazon and Antipyrin degrading bacteria. Zbl Bakteriol Hyg, lAbt Orig C2 45-60. 

Carmichael, P.L., She, M.N. and Phillips, D.H. (1992). Detection and characterization by P-postlabelling of DNA adducts induced by a Fenton-type oxygen radical-generating system. Carcinogenesis 13, 1127-1135. 

In the realm of drug discovery, the detection and characterization of target-ligand interactions is a critical process for lead identification, validation, and optimization. 

M6. Maekawa, M., Sudo, K., Kitajima, M., Matsuura, Y Li, S. S.-L., and Kanno, T., Detection and characterization of new genetic mutations in individuals heterozygous for lactate dehydroge-nase-B (H) deficiency using DNA conformation polymorphism analysis and silver staining. Hum. Genet. 91, 163-168 (1993). 

Several new thermal analytical techniques are potentially valuable for the study of second-order transitions in the characterization of amorphous solids and for the accurate determination of glass transition temperatures. These modem techniques can detect and characterize glass transitions and other second-order transitions that are not detectable by conventional thermal analytical techniques such as DSC, TGA, or TMA. 

Larsson, L. Saraf, A. Use of gas chromatography-ion trap mass spectrometry for the detection and characterization of microorganisms in complex samples. Mol. Biotechnol. 1997, 7, 279-287. 

Despeyroux, D. Phillpotts, R. Watts, P. Electrospray mass spectrometry for detection and characterization of purified cricket paralysis virus (CrPV). Rapid Comm. Mass Spectrom. 1996,10, 937-941. 

The principal defining properties of the molten globule are as follows (Arai and Kuwajima, 2000) (1) substantial secondary structure (2) no significant tertiary structure (3) structure only slightly expanded from the native state (10—30% increase in radius of gyration) (4) a loosely packed hydrophobic core with increased solvent accessibility. The first two criteria are readily assessed by far- and near-UV CD, respectively. Therefore, CD has been extensively applied to the detection and characterization of molten globules. 

Simard JR, Getlik M, Griitter C et al (2009) Development of a fluorescent-tagged kinase assay system for the detection and characterization of allosteric kinase inhibitors. J Am ChemSoc 131 13286-13296... 

Lindgren M, Sorgjerd K, Hammarstrom P (2005) Detection and characterization of aggregates, prefibrillar amyloidogenic oligomers, and protofibrils using fluorescence spectroscopy. Biophys J 88(6) 4200-4212... 

We have used such cells (J 4) to generate and measure the kinetic stability over a wide temperature range of a wide variety of unstable species. The easiest experiments - and the first performed - were simply the photolysis of a metal carbonyl in liquid xenon doped with dissolved N2 and hence replacement of CO by N2. The V(N-N) IR bands are little weaker than v(C-O) bands and hence detection and characterization are straightforward, particularly when use is made of previous matrix studies. Species examined include Cr (CO) (N )x x = Ni(CO)3(N ) ( 16). ... 

Group VIA (Cr, Mo, W). y-Radiolysis studies have been carried out for the simple hexacarbonyls (31,32) and for certain carbonyl iodides (33) and cyclopentadienyl carbonyl iodides (34). In the case of the hexacarbonyls (31,32), two free-radical products have been detected and characterized for Cr(C0)6, weak unidentified EPR signals have been observed for Mo(C0)6, but irradiated W(C0)6 apparently contains no detectable paramagnetic centres. 

Although the library of catalysts was actually very small, this combinatorial approach was shown to work surprisingly well. It remains to be seen if truly high throughput can be put into practice, which would require on-line methods for the detection and characterization of the particles bearing the polymers. 

---