Spectral discrimination

Eig. 2. Thermography combined with precise spectral discrimination provides for spatial spectroscopy for remote spectral sensing as well as "spot sensing"... 

Spectral discrimination (9) and specific gas detection can be modeled if one assumes the gas absorbs photons of a specific wavelength exponentially with distance into the gas (Beet s law). When the absorption distance is x (cm), the incident it power density at the detector in the spectral band pass is J (W/cm ) and the power density incident on the gas is the gas concentration, C (ppm) is given by ... 

The detection of a specific gas (10) is accompHshed by comparing the signal of the detector that is constrained to the preselected spectral band pass with a reference detector having all conditions the same except that its preselected spectral band is not affected by the presence of the gas to be detected. Possible interference by other gases must be taken into account. It may be necessary to have multiple channels or spectral discrimination over an extended Spectral region to make identification highly probable. Except for covert surveillance most detection scenarios are highly controlled and identification is not too difficult. 

Although the feasibility of direct probe MS for the analysis of additives in complex polymeric matrices has been demonstrated (Section 6.4), application is limited, difficult and requires above-average mass-spectroscopic expertise. Direct desorption in the MS probe is usually limited to screening of volatile components. Direct multicomponent spectroscopic analysis has other hurdles to overcome (UV/VIS lack of spectral discrimination IR/R functional-group recognition only, with no discriminative power for additives with similar functionalities NIRS unsuitable for R D problems NMR sensitivity). 

Of course in defining application fields of certain types of 10 sensors they have to be compared with competitors in the terms of the market. Strong points of optical sensors are no EMI, potential of high sensitivity and spectral discrimination. The guided mode character adds to these no need of... 

Zhu L, Stryjweski WJ, Soper SA (2004) Multiplexed fluorescence detection with micro-fabricated devices with both time-resolved and spectral-discrimination capabilities using near-infrared fluorescence. Anal Biochem 330 206-218... 

Aslund A, Herland A, Hammarstrdm P, Nilsson KPR, Jonsson BH, Inganas O, Konradsson P (2007) Studies of luminescent conjugated polythiophene derivatives enhanced spectral discrimination of protein conformational states. Bioconjug Chem 18 1860-1868... 

The small spectral discrimination between CO, 02, and NO in the Fe(P) system as compared with the Ru(P) or Os(P) systems may also be due to the less pronounced 7T-donor ability of the Fe11 ion relative to the Ru11 or Os11 ion in a porphyrin system. The spectral differences between the nitrosyls and the dioxygen complexes are especially small. The a- or (3-bands indicated for these complexes (Series a, c, d, Table 13) fall in the range where the a- or 0-bands of the corresponding Zn11 porphyrins are observed (Xa for Zn(Proto-IX) 586 nm (43) for Zn (TPP) 548 nm, see Table 3). As... 

J. Homola, H. B. Lu, and S. S. Yee, "Dual-Channel Surface Plasmon Resonance Sensor with Spectral Discrimination of Sensing Channels Using a Dielectric Overlayer,"... 

The quantitative use of high resolution solution spectra for the determination of configuration has also been ably demonstrated for other elastomer systems such as polypentenamer (23,24,25), polybutadiene (26, ), and polyisoprene (1 ). One would like to explore the possibilities of analyzing solid elastomer systems in terms of high resolution spectral discrimination. 

Infrared spectroscopy has been shown to spectrally discriminate normal and malignant tissues in conjunction with statistical analysis methods, many of these mathematical methods are applicable to Raman spectral analysis. 

Figure 1-4. Raman spectra of, from the top magnesite, dolomite, aragonite and calcite-indicating the spectral discrimination between these carbonates...

Schmidt, K. S. and A. K. Skidmore. 2003. Spectral discrimination of vegetation types in a coastal wetland. Rem. Sens. Environ. 5 1-17. 

While spectral discrimination is the most common method of base caUing used, temporal discrimination offers several advantages (1) The Hfetime of the fluoro-phore is independent of concentration, (2) fluorescence Hfetime values may be determined with more accuracy than fluorescence intensity, (3) temporal measurements are not hindered by broad emission profiles, and (4) a single detection channel may be used. Soper has developed a method using heavy atom modified NIR dyes for base calling in DNA sequencing using temporal discrimination [74]. One... 

One alternative method is to use differences in fluorescence lifetime as the metric to discriminate between the fluor-labels [138,139]. Several potential benefits of measuring lifetimes for DNA sequencing have been described [140,141]. Lifetimes may be accurately determined in the absence of spectral discrimination thus, discrete lifetimes may be determined for mixtures of fluors coeluting in a single peak. Lifetimes are also independent of intensity even at concentrations where relatively poor SNR may lead to an erroneous fluorescence intensity-based call. In addition, since scattered light has an effective lifetime of zero, scatter may be temporally rejected and is thus less of an issue. However, this method requires a family of fluors in which the lifetimes are resolvable [141-143] and the use of relatively complex electronics [141]. 

Zhu, L., Stryjewski, W, Lassiter, S., and Soper, S.A., Fluorescence multiplexing with time-resolyed and spectral discrimination using a near-IR detector. Anal. Chem., 75, 2280, 2003. 

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