Intensity and half-width measurements in the 1·525 μm band of acetylene

1975 ◽  
Vol 15 (3) ◽  
pp. 267-273 ◽  
Author(s):  
Prasad Varanasi ◽  
Babu R.P. Bangaru
Keyword(s):  
Half Width ◽  
Width Measurements

ABSORPTION-LINE BROADENING IN BORON-DOPED SILICON

1967 ◽  
Vol 45 (8) ◽  
pp. 2797-2804 ◽  
Author(s):  
J. J. White
Keyword(s):  
Absorption Line ◽  
Excited States ◽  
Half Width ◽  
Line Broadening ◽  
Additional Information ◽  
Boron Doped ◽  
Doped Silicon ◽  
Time Part ◽  
Width Measurements ◽  
First Time

In boron-doped silicon, the excitation of bound holes from the acceptor ground state to the excited states leads to an infrared absorption-line spectrum. In a recent half-width study of the boron absorption lines, Colbow (1963) separated the various line-broadening contributions for the first time. Part of Colbow's half-widths is now found to be due to external strains introduced by the sample mounting. New half-width measurements of "strain-free" mounted boron-doped silicon are presented, Colbow's work is corrected, and additional information regarding the various broadening contributions is given.

A Comparative Study of Electron Density Determination Methodologies in the Helium Microwave-Induced Plasma

1989 ◽  
Vol 43 (4) ◽  
pp. 621-626 ◽  
Author(s):  
John M. Workman ◽  
Harry B. Fannin ◽  
Peter G. Brown ◽  
Joseph A. Caruso
Keyword(s):  
Line Shape ◽  
Atmospheric Pressure ◽  
Maximum Intensity ◽  
Half Width ◽  
Balmer Line ◽  
Electron Number ◽  
Microwave Induced Plasma ◽  
Intensity Measurements ◽  
Line Shape Analysis ◽  
Width Measurements

Electron number densities were examined in a low-power atmospheric-pressure helium microwave-induced plasma. Two hydrogen-based methods and two helium-based methods were employed to estimate electron concentration. The hydrogen 4471 Å Balmer line was examined with the use of both line shape and full width at half-maximum intensity measurements. The data suggest that half-width calculations underestimate electron densities. Half-width measurements of neutral helium lines result in number densities which appear to be overestimated. This inaccuracy is thought to be the result of apparatus broadening. Finally, the use of quasi-degenerate helium neutral lines possessing forbidden and allowed components afforded electron concentrations similar to those derived from the Balmer beta line shape analysis.

Low - Voltage Scanning Electron Microscopy Imaging, Secondary and Backscatter, With Microchannel Plate Detector

1990 ◽  
Vol 48 (1) ◽  
pp. 442-442
Author(s):  
Galen Powers ◽  
Ray Cochran
Keyword(s):  
Low Voltage ◽  
Beam Current ◽  
Microchannel Plate ◽  
Normal Operation ◽  
Microscopy Imaging ◽  
Backscatter Signal ◽  
Vacuum Interface ◽  
Width Measurements ◽  
Working Distance ◽  
Beam Currents

The capability to obtain symmetrical images at voltages as low as 200 eV and beam currents less than 9 pico amps is believed to be advantageous for metrology and study of dielectric or biological samples. Symmetrical images should allow more precise and accurate line width measurements than currently achievable by traditional secondary electron detectors. The low voltage and current capability should allow imaging of samples which traditionally have been difficult because of charging or electron beam damage.The detector system consists of a lens mounted dual anode MicroChannel Plate (MCP) detector, vacuum interface, power supplies, and signal conditioning to interface directly to the video card of the SEM. The detector has been miniaturized so that it does not interfere with normal operation of the SEM sample handling and alternate detector operation. Biasing of the detector collection face will either add secondaries to the backscatter signal or reject secondaries yielding only a backscatter image. The dual anode design allows A−B signal processing to provide topological information as well as symmetrical A+B images.Photomicrographs will show some of the system capabilities. Resolution will be documented with gold on carbon. Variation of voltage, beam current, and working distance on dielectric samples such as glass and photoresist will demonstrate effects of common parameter changes.

scholarly journals Degradation Monitoring in Reinforced Concrete with 3D Localization of Rebar Corrosion and Related Concrete Cracking

2021 ◽  
Vol 11 (15) ◽  
pp. 6772
Author(s):  
Charlotte Van Steen ◽  
Els Verstrynge
Keyword(s):  
Reinforced Concrete ◽  
Degradation Mechanism ◽  
Heterogeneous Material ◽  
Corrosion Damage ◽  
Corrosion Process ◽  
Internal Damage ◽  
Rc Structures ◽  
Degradation Monitoring ◽  
Rebar Corrosion ◽  
Width Measurements

Corrosion of the reinforcement is a major degradation mechanism affecting durability and safety of reinforced concrete (RC) structures. As the corrosion process starts internally, it can take years before visual damage can be noticed on the surface, resulting in an overall degraded condition and leading to large financial costs for maintenance and repair. The acoustic emission (AE) technique enables the continuous monitoring of the progress of internal cracking in a non-invasive way. However, as RC is a heterogeneous material, reliable damage detection and localization remains challenging. This paper presents extensive experimental research aiming at localizing internal damage in RC during the corrosion process. Results of corrosion damage monitoring with AE are presented and validated on three sample scales: small mortar samples (scale 1), RC prisms (scale 2), and RC beams (scale 3). For each scale, the corrosion process was accelerated by imposing a direct current. It is found that the AE technique can detect damage earlier than visual inspection. However, dedicated filtering is necessary to reliably localize AE events. Therefore, AE signals were filtered by a newly developed post-processing protocol which significantly improves the localization results. On the smallest scale, results were confirmed with 3D micro-CT imaging, whereas on scales 2 and 3, results were compared with surface crack width measurements and resulting rebar corrosion levels.

scholarly journals Evaluation of grain boundaries as percolation pathways in quartz-rich continental crust using Atomic Force Microscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ritabrata Dobe ◽  
Anuja Das ◽  
Rabibrata Mukherjee ◽  
Saibal Gupta
Keyword(s):  
Atomic Force Microscopy ◽  
Grain Boundary ◽  
Continental Crust ◽  
Electron Backscatter Diffraction ◽  
Vital Role ◽  
Force Microscopy ◽  
Atomic Force ◽  
Width Measurements ◽  
Lower Temperature ◽  
Backscatter Diffraction

AbstractHydrous fluids play a vital role in the chemical and rheological evolution of ductile, quartz-bearing continental crust, where fluid percolation pathways are controlled by grain boundary domains. In this study, widths of grain boundary domains in seven quartzite samples metamorphosed under varying crustal conditions were investigated using Atomic Force Microscopy (AFM) which allows comparatively easy, high magnification imaging and precise width measurements. It is observed that dynamic recrystallization at higher metamorphic grades is much more efficient at reducing grain boundary widths than at lower temperature conditions. The concept of force-distance spectroscopy, applied to geological samples for the first time, allows qualitative estimation of variations in the strength of grain boundary domains. The strength of grain boundary domains is inferred to be higher in the high grade quartzites, which is supported by Kernel Average Misorientation (KAM) studies using Electron Backscatter Diffraction (EBSD). The results of the study show that quartzites deformed and metamorphosed at higher grades have narrower channels without pores and an abundance of periodically arranged bridges oriented at right angles to the length of the boundary. We conclude that grain boundary domains in quartz-rich rocks are more resistant to fluid percolation in the granulite rather than the greenschist facies.

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