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Ann Arbor, MI, United States

Taquet N.,University of Lorraine | Pironon J.,University of Lorraine | De Donato P.,University of Lorraine | Lucas H.,Kaiser Optical Systems Inc. | Barres O.,University of Lorraine
International Journal of Greenhouse Gas Control | Year: 2013

This study reports the ability of the coupled Raman-FTIR/completion system to establish continuous measurements of soil gases for the monitoring of the CO2 sequestration sites. The method was deployed in the first French CCS pilot at Lacq-Rousse, in France during the injection operation. In this study, the continuous recording of the N2, O2, H2O and CO2 concentrations in soil allowed by the coupled Raman/FTIR completion system appears as a first step to decipher CO2 abnormal variations at the surface of the CCS site. © 2012 Elsevier Ltd.

Mller J.,Heinrich Heine University Dusseldorf | Knop K.,Heinrich Heine University Dusseldorf | Thies J.,L. B. Bohle Maschinen Verfahren GmbH | Uerpmann C.,Kaiser Optical Systems Inc. | Kleinebudde P.,Heinrich Heine University Dusseldorf
Drug Development and Industrial Pharmacy | Year: 2010

Background: Active coating is a specific application of film coating where the active ingredient is comprised in the coating layer. This implementation is a challenging operation regarding the achievement of desired amount of coating and coating uniformity. To guarantee the quality of such dosage forms it is desirable to develop a tool that is able to monitor the coating operation and detect the end of the process. Method: Coating experiments were performed at which the model drug diprophylline is coated in a pan coater on placebo tablets and tablets containing the active ingredient itself. During the active coating Raman spectra were recorded in-line. The spectral measurements were correlated with the average weight gain and the amount of coated active ingredient at each time point. The developed chemometric model was tested by monitoring further coated batches. Furthermore, the effects of pan rotation speed and working distance on the acquired Raman signal and, hence, resulting effect of the chemometric model were examined. Results: Besides coating on placebo cores it was possible to determine the amount of active ingredient in the film when coated onto cores containing the same active ingredient. In addition, the method is even applicable when varying the process parameters and measurement conditions within a restricted range. Conclusion: Raman spectroscopy is an appropriate process analytical technology too. © Informa UK, Ltd.

Raw data inputs are treated as independent signal sources to reduce computational lag without adversely affecting signal-to-noise ratio (SNR). Applications include spectroscopy, multiple linear regression, mass balance quantitation and the calculation of physical properties. The input-specific averaging has been applied to Raman spectroscopy, where the inputs are averaged spectra from which peak heights or areas are obtained from integration. Alternatively, peak areas or heights can be obtained from unaveraged spectra and are then averaged before use in further calculations as inputs to produce a desired output. The output(s) are linear or nonlinear combinations of the peak heights or areas, coupled with weighting factors which relate the raw inputs to a quantitative output such as concentration of a chemical species. Each specific input can use a different type of averaging. The overall goal may be optimization for best precision, and/or optimization for minimum lag time.

A material which is generally transparent in the visible region of the spectrum but reflective at laser wavelengths reduces undesirable, substrate-induced Raman and fluorescence scattering. A substrate provides a surface for supporting the sample, with the material being disposed between the surface of the substrate and the sample. The material is substantially transparent in the visible region of the spectrum but reflective at the laser wavelength, thereby minimizing unwanted Raman or fluorescence scattering that would be produced by the substrate if the material were not present. The substrate will typically be a glass microscope slide or multi-cell well plate. The optical filter material is preferably a multilayer dielectric filter acting as a hot mirror that reflects near-infrared energy. An advantage of visible transmission is that it allows back illumination from behind/underneath the slide or well plate, thereby being visible to a microscopes eyepiece or video camera. Methods and article are also disclosed.

Kaiser Optical Systems Inc. | Date: 2013-05-28

Methods and apparatus facilitate dynamic range balancing for multi-component peaks of widely varying magnitude in an optical spectrometer. In a specific embodiment, filters attenuate the CH stretch region to produce a better fit of a multi-component hydrocarbon Raman spectrum to the dynamic range of a CCD detector. The filter may be translated into and out of the collimated collection beam to achieve a varying degree of attenuation. In certain applications, the filter is insertable into a collimated collection beam within a fiber-optic probe head to collect Raman spectra. The invention may include optical elements to create the collimated collection beam if not already present or not suitable for insertion of the filter. A second filter, an opaque or neutral density filter, may be insertable into the collimated collection beam to attenuate a broad spectral response within and outside the spectral range.

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