Fingerprinting technique

The identification of polymers is frequently based on a comparison of glass transition or melting temperature, with literature values (Table 6.1). 

Very often thermogravimetric curves are characteristic for particular polymers and can therefore be used for their identification. Because of the poor heat conductivity, temperature gradients occur within samples at high heating rates. To obtain reproducible results, a standardisation of heating rate should be used, e.g., 10 °C/min, when comparing an unknown polymer with a set of reference polymers. 

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The series of deviation from a strictly octahedral crystal field follows the sequence ammonium tungstate > tungstic acid > WO3 [14]. The s->d transition becomes allowed as distortion of the octahedral environment increases. Viewed as a fingerprint technique. Figure 6 shows that the bulk of W present in both WZ (calcined) and PtWZ(acac, reduced) behaves as WO3, as also shown by our XRD data [10], sugesting that only a small extent of W reduction is expected to have taken place during catalyst conditioning prior to reaction. 

John Lach, William H. Mangione-Smith, and Miodrag Potkonjak. FPGA Fingerprinting Techniques for Protecting Intellectual Property , 1998 Custom Integrated Circuits Conference, Santa Clara, CA, pp. 299-302, May 1998. 213, 214,... 

In reality, NMR spectroscopy has broadened the scope and absolute possibility for performing more extensive as well as intensive studies with regard to recording the spectrum of isolated and synthesized organic molecules in addition to their mechanistic and stereochemical details hitherto inaccessible. Therefore, NMR spectroscopy finds its applications for compound identification, by means of a fingerprint technique very much identical to that used in lR-spectroscopy. Besides, it is invariably utilized as a specific method of assay for the individual constituents of a mixture. A few typical examples of drug assays will be dealt separately at the end of this chapter to justify its efficacy and usefulness. 

Chemical equilibrium experiments, e.g., distribution ratio measurements, cannot distinguish between these two types of complexes however, they may be identified by fingerprinting techniques like NMR, IR, or x-ray structure determinations. Existence of similar adducts like MA Bb support the existence of self-adducts. The case of promethium(lll) acetylacetone is an interesting illustration of this problem. 

The detection of a chromophore permits us to deduce the presence of a structural fragment or a structural element in the molecule. The fact that it is the chromophores and not the molecules as a whole that give rise to spectral features is fortunate, otherwise spectroscopy would only permit us to identify known compounds by direct comparison of their spectra with authentic samples. This "fingerprint" technique is often useful for establishing the identity of known compounds, but the direct determination of molecular structure building up from the molecular fragments is far more powerful. 

Other MS-fingerprinting techniques that are in commercial development are based on atmospheric pressure ionisation (API), resonance-enhanced multiphoton ionisation (REMPI) TOE and proton-transfer reaction (PTR). They are rapid, sensitive and specific and allow measurements in real time and may play an increasingly important role in the future development of electronic noses and tongues. 

The DNA fingerprinting technique has now been applied almost routinely in all modem forensic laboratories to solve various crimes. When a DNA... 

The DNA of father and offspring are related, but not completely identical. Thus, in paternity cases the DNA fingerprinting technique comes very handy, and the identity of the father can be established with a probability of 100000 to 1. 

Fingerprinting methods such as the anthocyanin methods and the Kirksey method for polyphenols (Kirksey el al., 1995) offer good ways to check for the addition of other fruits in a product. As the adulterators have become more sophisticated in the approaches that they use to extend juices, there has been a need for more complex methods of analysis. This means that it is now not uncommon to have to use fingerprinting techniques and isotopic methods to detect the most sophisticated forms of adulteration. These sophisticated analytical methods can even involve detection of the isotope ratios within a class of compounds such as sugars (Hammond el al., 1998). Using the RSSL 13C-IRIS approach, which was developed with financial support from the UK Food Standards Agency, it was possible to reduce the detection limit for the addition of C4-derived sugars to juices by about a factor of two. 

A dozen of utilities implements passive fingerprinting techniques. Most of them compare packet fields to a given fingerprints database. A match means that the OS has been determined. Some tools differ by the answer provided in the case of uncertainty, others by their fingerprinting tables. As a consequence, we have decided to use three different passive fingerprinting utilities, with the possibility to add new ones later on if needed. They are respectively called Disco, pOf and ettercap [38], [39], [40], They all use tcpdump pcap files as input. Their output is in text format which we parse to store the information into the database. Details of the tables are provided in the next Section. 

Konig, I. and Hollatz, R. (1990) A fingerprint technique using Mossbauer spectroscopy for the determination of individual chemical iron species in young sediments. Hypeifine Interact., 57, 2245. 

Quantitative data ranges for DKPs found in four cocoas are expressed in mg of DKP/Kg of fat free-cocoa as follovs c(Gly-Leu), 0-25 c(Gly-Pro), 2-7 c(Gly-Phe), 0-11 c(Ala-Gly), 0-12 c(Ala-Val), 56-143, c(Ala-Leu), 22-69 c(Ala-Pro), 19—44 c(Ala-Phe), 2-19 c(Leu-Pro), 39-115 and c(Phe-Pro), 0-26. Tovard the end of the study an eleventh DKP vas qualitatively identified in cocoa and shoved to be c(Val-Phe). Our results confirmed the DKPs found by previous authors (4, 17) except for c(Asp-Pro) and c(Asp-Phe) which were apparently not amenable to direct GC analysis. Tvo nev DKPs, c(Gly-Leu) and c(Ala-Leu) vere observed for the first time in cocoa. Cocoas contained similar kinds of DKPs, however quantitative differences suggested that DKP profiles obtained by HRGC might serve as a sensitive fingerprint technique. Also, dutched cocoas typically had lover levels of DKPs compared to ordinary processed cocoas. 

Marker-assisted breeding The use of genetic fingerprinting techniques to introduce genes of interest from one plant variety to another. Relies on knowledge of DNA sequences in a particular genomic region. 

XANES spectra can be used as a fingerprint technique, provided that the spectra of suitable reference compounds are available. If this is the case, XANES spectra are much easier to interpret than EXAFS spectra. 

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