Determination of hydrocarbons in water by evanescent wave absorption spectroscopy in the near-infrared region

1996 ◽  
Vol 354 (7-8) ◽  
pp. 848-851 ◽  
Author(s):  
E. Sensfelder ◽  
J. B�rck ◽  
H. -J. Ache
Keyword(s):  
Absorption Spectroscopy ◽  
Evanescent Wave ◽  
Near Infrared ◽  
Infrared Region ◽  
Wave Absorption ◽  
Near Infrared Region

Optical Fiber Device and Biological Tissue Phantoms for Determination of Optical Parameters in the Near‐Infrared Region

2004 ◽  
Vol 32 (5) ◽  
pp. 489-505 ◽  
Author(s):  
Omar Feix do Nascimento ◽  
Antonio Balbin Villaverde ◽  
Renato Amaro Zângaro ◽  
Marcos Tadeu Tavares Pacheco ◽  
Steven F. Durrant
Keyword(s):  
Optical Fiber ◽  
Biological Tissue ◽  
Near Infrared ◽  
Infrared Region ◽  
Optical Parameters ◽  
Tissue Phantoms ◽  
Near Infrared Region

Spectroscopic Investigation of the High Pressure Ethylene Polymerization

1984 ◽  
Vol 39 (4) ◽  
pp. 399-411 ◽  
Author(s):  
M. Buback
Keyword(s):  
High Pressure ◽  
Absorption Spectroscopy ◽  
Spectroscopic Investigation ◽  
Ethylene Polymerization ◽  
Near Infrared ◽  
Infrared Region ◽  
Rate Equations ◽  
Near Infrared Region ◽  
Maximum Temperatures ◽  
Quantitative Absorption

Quantitative absorption spectroscopy in the infrared and near-infrared region enables kinetic and thermodynamic investigations to be performed on systems at high temperatures and pressures. The technique is illustrated for the ethylene polymerization. From spectroscopic experiments up to 3 kbar at maximum temperatures of 250 °C, the rate equations of the thermally, of the photochemically, and of the chemically initiated polymerization are determined.

Scattering properties of recycled pulp at the near infrared region and its effect on the determination of residual ink

TAPPI Journal ◽  
2011 ◽  
Vol 10 (6) ◽  
pp. 17-22 ◽  
Author(s):  
MIKA KÖRKKÖ ◽  
OSSI LAITINEN ◽  
ANTTI HAAPALA ◽  
ARI ÄMMÄLÄ ◽  
JOUKO NIINIMÄKI
Keyword(s):  
Near Infrared ◽  
Filler Content ◽  
Infrared Region ◽  
Scattering Coefficient ◽  
Unknown Constant ◽  
Scattering Coefficients ◽  
Recycled Pulp ◽  
Near Infrared Region

Residual ink in recycled pulp can be determined from a wide variety of pads and sheets using either a constant or measured near infrared (NIR) scattering coefficient. The method is usually chosen on the basis of the opaqueness of the prepared test media. Although both methods are regularly used, it is unclear whether NIR scattering properties of pulp vary due to changing proportions of fibers and fines and whether the changing NIR scattering coefficient affects the residual ink values. We investigated the effect of varying scattering coefficient on residual ink results obtained with unknown (constant) and known (measured) NIR scattering coefficients. We measured the NIR scattering coefficients and residual ink values (using the wavelength of 700 nm) from low-grammage sheets with deliberately varied filler content. By varying the filler content, changes were detected in the NIR scattering properties of pulp; therefore, the residual ink values were biased when a constant scattering coefficient was used. However, when the scattering coefficient was measured during the determination of residual ink, no deviation was observed when compared with the values calculated according to mass proportions. The measured NIR scattering coefficient should always be used during the determination of residual ink values.

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