Near infrared sensors

Stewart G., Jin W., Culshaw B., Prospects for fibre-optic evanescent-field gas sensors using absorption in near-infrared, Sensors and Actuators B 1997 38-39 42-47. 

Rantanen, J. Rasanen, E. Tenhunen, J. etal, In-line moisture measurement during granulation with a four-wavelength near infrared sensor An evaluation of particle size and binder effects Eur. J. Pharm. Biopharm. 2000, 50, 271-276. 

Miniaturized near-infrared sensors were developed and implemented for online analysis and automated process control to also meet the safety requirements for handling of ozone and halogenating agents [49,50]. A target is to reduce the time from process idea to production (time-to-market) as well as development costs and costs for installation of the production unit. As pharmaceutical industry relies on the manufacture of many different products on smaller scale, and intermediates in quantities ranging from some kilograms to tons per year a modular approach toward a multipurpose microreactor plant is demanded. 

Some applications require gradients to be formed to a prescribed set-point value. The most common parameter used to identify the set-point value is the ionic strength or conductivity of the buffer solution. Another possibility for alcohol or acetonitrile - water mixtures is the use of a near infrared sensor. 

A carpet separation process is illustrated in Fig. 13.1. First the carpet is sorted by face fiber. A near infrared sensor can identify the face fiber within a second even though nylon 6 and nylon 66 have similar infrared spectra. These two types of nylon carpet must be separated since they are incompatible. Next a guillotine is used to cut the carpet into small enough pieces to feed a shredder. After shredding some of the latex, calcium carbonate and dirt will separate from the carpet. To improve the purity of the carpet, fine grinding is necessary. Then a density separator can be used to remove more filler and dirt. Since there is a significant difference in the densities of nylon and polypropylene, a density separator can be used to separate nylon face fibers from polypropylene backing fabrics. Hydrocyclones can separate these polymers rapidly. Sink-float baths can accomplish this... 

Lucht H, et al.. Plastic separation of automotive waste by superfast near-infrared sensors. Global plastics environmental conference proceedings 2002. 

Mahmoud, M. A., and El-Sayed, M. A. (2010) Gold nanoframes Veiy high surface plasmon fields and excellent near-infrared sensors,/ Am. Chem. Soc., 132(36), 12704-12710. 

Luminescence can be defined as the emission of light (intended in the broader sense of ultraviolet, visible, or near infrared radiation) by electronic excited states of atoms or molecules. Luminescence is an important phenomenon from a basic viewpoint (e.g., for monitoring excited state behavior) [1] as well as for applications (lasers, displays, sensors, etc.) [2,3]. 

Tung, C. H., Gerszten, R. E., Jaffer, F. A. and Weissleder, R. (2002). A novel near-infrared fluorescence sensor for detection of thrombin activation in blood. Chembiochem 3, 207-211. 

Inaba H., Chan K., Ito H., All-optical remote gas sensor system over a 20 km range based on low-loss optical fibers in the near infrared region, Proc. SPIE-Int. Soc. Opt. Eng. 1984 514 211. 

Scorsone E., Christie S., Persaud K.C., Simon P., Kvasnik F., Fibre-optic evanescent sensing of gaseous ammonia with two forms of a new near-infrared dye in comparison to phenol red, Sensor. Actual. B-Chem. 2003 90 37-45. 

The pH measurement can by realized using sol-gel films and evanescent-wave sensors method74. To incorporate a near-infrared pH sensitive fluorescent dye, a thin-film coating on the core of a multimode fiber was used. By evanescent wave excitation an absorption or fluorescent based sensor can be realized for use in high pH regions. 

The intent of this chapter is not to provide an exhaustive review of chemical- and biosensors and probes, but rather to offer a brief overview of existing optical techniques and an indepth analysis of near-infrared (NIR) fluorogenic probes and sensors for the detection of metal ions, solution pH, and biomolecules and to present some of the latest results. 

T. Okazaki, T. Imasaka, and N. Ishibashi, Optical-fiber sensor based on the second-harmonic emission of a near-infrared semiconductor laser as light source, Anal Chim Acta 209, 327-331 (1988). 

M. Daneshvar, G. A. Casay, M. Lipowska, G. Patonay, and L. Strekowski, Investigation of a near-infrared fiber-optic immunosensor, SPIE—The International Society for Optical Engineering Chemical, Biochemical, and Environmental Fiber Sensors V 2063, 128-138(1993). 

For our purpose, it is convenient to classify the measurements according to the format of the data produced. Sensors provide scalar valued quantities of the bulk fluid i. e. density p(t), refractive index n(t), viscosity dielectric constant e(t) and speed of sound Vj(t). Spectrometers provide vector valued quantities of the bulk fluid. Good examples include absorption spectra A t) associated with (1) far-, mid- and near-infrared FIR, MIR, NIR, (2) ultraviolet and visible UV-VIS, (3) nuclear magnetic resonance NMR, (4) electron paramagnetic resonance EPR, (5) vibrational circular dichroism VCD and (6) electronic circular dichroism ECD. Vector valued quantities are also obtained from fluorescence I t) and the Raman effect /(t). Some spectrometers produce matrix valued quantities M(t) of the bulk fluid. Here 2D-NMR spectra, 2D-EPR and 2D-flourescence spectra are noteworthy. A schematic representation of a very general experimental configuration is shown in Figure 4.1 where r is the recycle time for the system. 

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