Real-time in situ observations of reaction and transport phenomena during silicate glass corrosion by fluid-cell Raman spectroscopy

2019 ◽  
Vol 18 (4) ◽  
pp. 342-348 ◽  
Author(s):  
Thorsten Geisler ◽  
Lars Dohmen ◽  
Christoph Lenting ◽  
Moritz B. K. Fritzsche
Keyword(s):  
Raman Spectroscopy ◽  
Real Time ◽  
Silicate Glass ◽  
Transport Phenomena ◽  
Glass Corrosion ◽  
In Situ Observations ◽  
Fluid Cell

scholarly journals SEVIRI Hyper-Fast Forward Model with Application to Emissivity Retrieval

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1532 ◽  
Author(s):  
Guido Masiello ◽  
Carmine Serio ◽  
Sara Venafra ◽  
Laurent Poutier ◽  
Frank-M. Göttsche
Keyword(s):  
Radiative Transfer ◽  
Real Time ◽  
Forward Model ◽  
Radiative Transfer Model ◽  
Computational Time ◽  
Transfer Model ◽  
Real Time Processing ◽  
In Situ Observations ◽  
Infrared Radiances

Timely processing of observations from multi-spectral imagers, such as SEVIRI (Spinning Enhanced Visible and Infrared Imager), largely depends on fast radiative transfer calculations. This paper mostly concerns the development and implementation of a new forward model for SEVIRI to be applied to real time processing of infrared radiances. The new radiative transfer model improves computational time by a factor of ≈7 compared to the previous versions and makes it possible to process SEVIRI data at nearly real time. The new forward model has been applied for the retrieval of surface parameters. Although the scheme can be applied for the simultaneous retrieval of temperature and emissivity, the paper mostly focuses on emissivity. The inverse scheme relies on a Kalman filter approach, which allows us to exploit a sequential processing of SEVIRI observations. Based on the new forward model, the paper also presents a validation retrieval performed with in situ observations acquired during a field experiment carried out in 2017 at Gobabeb (Namib desert) validation station. Furthermore, a comparison with IASI (Infrared Atmospheric Sounder Interferometer) emissivity retrievals has been performed as well. It has been found that the retrieved emissivities are in good agreement with each other and with in situ observations, i.e., average differences are generally well below 0.01.

scholarly journals Real-Time In Situ Observations Reveal a Double Role for Ascorbic Acid in the Anisotropic Growth of Silver on Gold

2020 ◽  
Vol 11 (8) ◽  
pp. 2830-2837
Author(s):  
Kinanti Aliyah ◽  
Jieli Lyu ◽  
Claire Goldmann ◽  
Thomas Bizien ◽  
Cyrille Hamon ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Real Time ◽  
Anisotropic Growth ◽  
In Situ Observations

Precise Determination of Percent Cure of Epoxide Polymers and Composites via Fiber-Optic Raman Spectroscopy and Multivariate Analysis

1997 ◽  
Vol 51 (2) ◽  
pp. 247-252 ◽  
Author(s):  
Jeffrey F. Aust ◽  
Karl S. Booksh ◽  
Christopher M. Stellman ◽  
Richard S. Parnas ◽  
Michael L. Myrick
Keyword(s):  
Raman Spectroscopy ◽  
Multivariate Analysis ◽  
Real Time ◽  
Fiber Optic ◽  
Precise Determination ◽  
Probe Design ◽  
Epoxide Polymers ◽  
Time Determination

A method for real-time determination of the percent cure of epoxies via in situ fiber-optic Raman spectroscopy has been developed. This method utilizes a probe design developed for real-time monitoring of polymer curing and multivariate analysis to interpret the data and determine percent cure. This method was demonstrated to be reliable to ±0.54% of cure in laboratory samples over a 50–99% cure range. A preliminary study measuring cure percentage in an industrial, glass-reinforced composite has been shown to be reliable to ±0.82% in the 40–90% cure range.

The Lightning and Dual-Polarization Radar Characteristics of Three Hail-Accumulating Thunderstorms

2020 ◽  
Vol 35 (4) ◽  
pp. 1583-1603
Author(s):  
Robinson Wallace ◽  
Katja Friedrich ◽  
Wiebke Deierling ◽  
Evan A. Kalina ◽  
Paul Schlatter
Keyword(s):  
Real Time ◽  
Scientific Community ◽  
Radar Data ◽  
Optimal Combination ◽  
Front Range ◽  
Dual Polarization ◽  
Translation Speed ◽  
Maximum Accumulation ◽  
In Situ Observations

AbstractThunderstorms that produce hail accumulations at the surface can impact residents by obstructing roadways, closing airports, and causing localized flooding from hail-clogged drainages. These storms have recently gained an increased interest within the scientific community. However, differences that are observable in real time between these storms and storms that produce nonimpactful hail accumulations have yet to be documented. Similarly, the characteristics within a single storm that are useful to quantify or predict hail accumulations are not fully understood. This study uses lightning and dual-polarization radar data to characterize hail accumulations from three storms that occurred on the same day along the Colorado–Wyoming Front Range. Each storm’s characteristics are verified against radar-derived hail accumulation maps and in situ observations. The storms differed in maximum accumulation, either producing 22 cm, 7 cm, or no accumulation. The magnitude of surface hail accumulations is found to be dependent on a combination of in-cloud hail production, storm translation speed, and hailstone melting. The optimal combination for substantial hail accumulations is enhanced in-cloud hail production, slow storm speed, and limited hailstone melting. However, during periods of similar in-cloud hail production, lesser accumulations are derived when storm speed and/or hailstone melting, identified by radar presentation, is sufficiently large. These results will aid forecasters in identifying when hail accumulations are occurring in real time.

Measurements of physical properties of gas hydrates and in situ observations of formation and decomposition processes via Raman spectroscopy and X-ray diffraction

2003 ◽  
Vol 81 (1-2) ◽  
pp. 351-357 ◽  
Author(s):  
T Uchida ◽  
S Takeya ◽  
L D Wilson ◽  
C A Tulk ◽  
J A Ripmeester ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Physical Properties ◽  
Gas Hydrates ◽  
Hydrate Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrate Layer ◽  
Decomposition Processes ◽  
In Situ Observations

Gas hydrate properties and phase transition kinetics were studied using Raman spectroscopic and X-ray diffraction methods. These techniques have the advantage of measuring physical properties such as crystal structure, gas composition, and cage occupancy of gas molecules without decomposing the sample. In situ observations using these techniques are indicative of formation and decomposition processes in gas hydrates. Raman spectroscopy is used for the analysis of gas concentrations and gas compositions of gas hydrates. The ν1 symmetrical C–H stretching vibration mode of methane molecules in the hydrate phase shows a doublet, and the relative intensity of the peaks determines the cage-occupancy ratio. However, as the Raman method is not standard for this application, we evaluated the method by analyzing the same methane hydrate sample using NMR and Raman scattering in a laboratory in Canada and also comparing the data with the Raman measurements made on the same sample in a laboratory in Japan. The data were consistent with all three measurements. In addition, in situ measurements of hydrate formation and decomposition were done by X-ray diffraction. The transformation of ice into CO2 hydrates occurred in two steps: at first a CO2 hydrate layer rapidly formed a coating on the ice surface and then the CO2 hydrate slowly grew according to the diffusion rates of CO2 and H2O molecules through the hydrate layer to the reaction sites. The same methods were used to observe the self-preservation effect of methane hydrates. PACS Nos.: 82.80Ch, 61.10Nz

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