Study of Water Absorption Lines in the Near Infrared

1975 ◽  
Author(s):  
Ali Javan
Keyword(s):  
Water Absorption ◽  
Near Infrared ◽  
Absorption Lines

Evaluation of Soya Bean Quality for Tofu Processing by near Infrared Spectroscopy

1998 ◽  
Vol 6 (A) ◽  
pp. A325-A328
Author(s):  
T.L. Hong ◽  
Samson C.S. Tsou ◽  
S.-J. Tsai
Keyword(s):  
Water Absorption ◽  
Absorption Rate ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Soya Bean ◽  
Control Measures ◽  
Raw Material ◽  
Prolonged Storage ◽  
Tannin Content ◽  
Water Absorption Rate

Soya bean, as the raw material for tofu processing, is required to be of high quality. The variety characteristics, storage conditions and harvesting seasons of soya bean are the major contributors to soya bean quality. This study attempted to use near infrared (NIR) spectroscopy to evaluate the processing quality of soya bean. Evaluation models using NIR spectroscopy were developed for the analyses of tannin content, degrees of lipid oxidation, detection of harvest seasons and measurement of water absorption rate. Simulation experiments demonstrated that these models were not only able to analyse major compositions of soya bean, but also to sort out soya bean samples and their suitability for tofu making regardless of various defects, such as high tannin content, low water absorption rate, prolonged storage and unfavourable harvest seasons. Statistic analysis suggested that these models could be used as mass-screening techniques for breeding programmes and quality control measures in tofu-processing factories.

scholarly journals Detection of Carbon Monoxide and Water Absorption Lines in an Exoplanet Atmosphere

Science ◽  
2013 ◽  
Vol 339 (6126) ◽  
pp. 1398-1401 ◽  
Author(s):  
Q. M. Konopacky ◽  
T. S. Barman ◽  
B. A. Macintosh ◽  
C. Marois
Keyword(s):  
Carbon Monoxide ◽  
Water Absorption ◽  
Absorption Lines

Multiple-Perturbation Two-Dimensional Near-Infrared Correlation Study of Time-Dependent Water Absorption Behavior of Cellulose Affected by Pressure

2013 ◽  
Vol 67 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Hideyuki Shinzawa ◽  
Kimie Awa ◽  
Isao Noda ◽  
Yukihiro Ozaki
Keyword(s):  
Water Absorption ◽  
Packing Density ◽  
Near Infrared ◽  
Correlation Method ◽  
Underlying Mechanism ◽  
Polymer Structure ◽  
Correlation Study ◽  
Time Dependent ◽  
Two Dimensional ◽  
Spectral Changes

Transient water absorption by cellulosic samples manufactured under varying pressure was monitored by near-infrared spectroscopy to explore the absorption behavior affected by the pressure. A substantial level of variation of the spectral features was induced by the water absorption and changes in the pressure. The detail of the spectral changes was analyzed with a multiple-perturbation, two-dimensional (2D) correlation method to determine the underlying mechanism. The 2D correlation spectra indicated that the compression of the cellulose increased the packing density of the samples, preventing the penetration of water. In addition, the compression substantially disintegrated its crystalline structure and eventually resulted in the development of inter- and intrachain hydrogen-bonded structures arising from an interaction between the water and cellulose. Consequently, the cellulose samples essentially underwent an evolutionary change in the polymer structure as well as in the packing density during the compression. This structural change, in turn, led to the seemingly complicated absorption trends, depending on the pressure.

Spectroscopy of the near-infrared afterglow of GRB 050904 at z = 6.3

2006 ◽  
Vol 2 (14) ◽  
pp. 264-264
Author(s):  
Nobuyuki Kawai
Keyword(s):  
Early Universe ◽  
Precise Measurement ◽  
Near Infrared ◽  
Absorption Lines ◽  
Heavy Elements ◽  
Star Forming ◽  
Long Wavelength ◽  
Faint Object ◽  
The Galaxy ◽  
Sharp Cutoff

AbstractWe present the optical/NIR spectrum of the afterglow of GRB 050904 obtained with the Faint Object Camera And Spectrograph on the Subaru 8.2m telescope taken 3.4 days after the burst. It is, as of June 2006, the only GRB with a known redshift larger than 6. The spectrum shows a clear continuum at the long wavelength end of the spectrum with a sharp cutoff at around 900nm due to Lyα absorption at a redshift of 6.3 with a damping wing. Little flux is present in the waveband shortward of the Lyα break. A system of absorption lines of heavy elements at redshift z = 6.295±0.002 were also detected, yielding a precise measurement of the largest known redshift of a GRB. Analysis of the silicon and sulphur absorption lines suggests a dense environment around the GRB with the metallicity larger than 0.1 solar, providing unique information on the galaxy and star forming region at z>6. This observation has shown that GRB is a powerful probe of the early universe.

scholarly journals Review: NIR Spectroscopy as a Suitable Tool for the Investigation of the Horticultural Field

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 503 ◽  
Author(s):  
Cattaneo ◽  
Stellari
Keyword(s):  
Chemical Composition ◽  
Process Control ◽  
Water Absorption ◽  
Near Infrared ◽  
Raw Materials ◽  
Nir Spectroscopy ◽  
Innovative Approach ◽  
Different Types ◽  
Key Issues ◽  
Horticultural Products

The last 10 years of knowledge on near infrared (NIR) applications in the horticultural field are summarized. NIR spectroscopy is considered one of the most suitable technologies of investigation worldwide used as a nondestructive approach to monitoring raw materials and products in several fields. There are different types of approaches that can be employed for the study of key issues for horticultural products. In this paper, an update of the information collected from the main specific International Journals and Symposia was reported. Many papers showed the use of NIR spectroscopy in the horticultural field, and the literature data were grouped per year, per product, and per application, such as studies of direct (chemical composition) and indirect (physical and sensorial) properties (P), process control (PC), and authenticity and classification studies (AC). A mention was made of a recent innovative approach that considers the contribution of water absorption in the study of biological systems.

scholarly journals Exoplanet atmospheres with GIANO

2018 ◽  
Vol 615 ◽  
pp. A16 ◽  
Author(s):  
M. Brogi ◽  
P. Giacobbe ◽  
G. Guilluy ◽  
R. J. de Kok ◽  
A. Sozzetti ◽  
...  
Keyword(s):  
Transmission Spectrum ◽  
Near Infrared ◽  
Absorption Lines ◽  
High Resolution Spectroscopy ◽  
High Dispersion ◽  
Molecular Absorption ◽  
Link Type ◽  
Circulation Patterns ◽  
Molecular Lines ◽  
Composition Structure

Context. High-resolution spectroscopy (R ≥ 20 000) at near-infrared wavelengths can be used to investigate the composition, structure, and circulation patterns of exoplanet atmospheres. However, up to now it has been the exclusive dominion of the biggest telescope facilities on the ground, due to the large amount of photons necessary to measure a signal in high-dispersion spectra. Aims. Here we show that spectrographs with a novel design – in particular a large spectral range – can open exoplanet characterisation to smaller telescope facilities too. We aim to demonstrate the concept on a series of spectra of the exoplanet HD 189 733 b taken at the Telescopio Nazionale Galileo with the near-infrared spectrograph GIANO during two transits of the planet. Methods. In contrast to absorption in the Earth’s atmosphere (telluric absorption), the planet transmission spectrum shifts in radial velocity during transit due to the changing orbital motion of the planet. This allows us to remove the telluric spectrum while preserving the signal of the exoplanet. The latter is then extracted by cross-correlating the residual spectra with template models of the planet atmosphere computed through line-by-line radiative transfer calculations, and containing molecular absorption lines from water and methane. Results. By combining the signal of many thousands of planet molecular lines, we confirm the presence of water vapour in the atmosphere of HD 189 733 b at the 5.5σ level. This signal was measured only in the first of the two observing nights. By injecting and retrieving artificial signals, we show that the non-detection on the second night is likely due to an inferior quality of the data. The measured strength of the planet transmission spectrum is fully consistent with past CRIRES observations at the VLT, excluding a strong variability in the depth of molecular absorption lines.

Relationship between rice tocopherols content and water absorption in Near InfraRed region

2015 ◽  
Author(s):  
Tiziana Maria Piera Cattaneo ◽  
Giovanna Cortellino ◽  
Stefania Barzaghi
Keyword(s):  
Water Absorption ◽  
Near Infrared ◽  
Infrared Region ◽  
Near Infrared Region

scholarly journals Iterative maximum a posteriori (IMAP)-DOAS for retrieval of strongly absorbing trace gases: Model studies for CH<sub>4</sub> and CO<sub>2</sub> retrieval from near infrared spectra of SCIAMACHY onboard ENVISAT

2005 ◽  
Vol 5 (1) ◽  
pp. 9-22 ◽  
Author(s):  
C. Frankenberg ◽  
U. Platt ◽  
T. Wagner
Keyword(s):  
High Resolution ◽  
Spectral Region ◽  
Near Infrared ◽  
Absorption Lines ◽  
Optical Absorption Spectroscopy ◽  
Maximum A Posteriori ◽  
Special Importance ◽  
A Posteriori ◽  
Pressure Profiles ◽  
Temperature And Pressure

Abstract. In the past, differential optical absorption spectroscopy (DOAS) has mostly been employed for atmospheric trace gas retrieval in the UV/Vis spectral region. New spectrometers such as SCIAMACHY onboard ENVISAT also provide near infrared channels and thus allow for the detection of greenhouse gases like CH4, CO2, or N2O. However, modifications of the classical DOAS algorithm are necessary to account for the idiosyncrasies of this spectral region, i.e. the temperature and pressure dependence of the high resolution absorption lines. Furthermore, understanding the sensitivity of the measurement of these high resolution, strong absorption lines by means of a non-ideal device, i.e. having finite spectral resolution, is of special importance. This applies not only in the NIR, but can also prove to be an issue for the UV/Vis spectral region. This paper presents a modified iterative maximum a posteriori-DOAS (IMAP-DOAS) algorithm based on optimal estimation theory introduced to the remote sensing community by rodgers76. This method directly iterates the vertical column densities of the absorbers of interest until the modeled total optical density fits the measurement. Although the discussion in this paper lays emphasis on satellite retrieval, the basic principles of the algorithm also hold for arbitrary measurement geometries. This new approach is applied to modeled spectra based on a comprehensive set of atmospheric temperature and pressure profiles. This analysis reveals that the sensitivity of measurement strongly depends on the prevailing pressure-height. The IMAP-DOAS algorithm properly accounts for the sensitivity of measurement on pressure due to pressure broadening of the absorption lines. Thus, biases in the retrieved vertical columns that would arise in classical algorithms, are obviated. Here, we analyse and quantify these systematic biases as well as errors due to variations in the temperature and pressure profiles, which is indispensable for the understanding of measurement precision and accuracy in the near infrared as well as for future intercomparisons of retrieval algorithms.

Sign in / Sign up

Export Citation Format

Share Document