scholarly journals Full width at half maximum intensity of G band in first order Raman spectrum of carbon material as a parameter for graphitization-a study with pyrolytic carbons

TANSO ◽  
2006 ◽  
Vol 2006 (221) ◽  
pp. 2-7 ◽  
Author(s):  
Akira Yoshida ◽  
Yutaka Kaburagi ◽  
Yoshihiro Hishiyama
Keyword(s):  
Raman Spectrum ◽  
Carbon Material ◽  
Maximum Intensity ◽  
Full Width ◽  
Half Maximum ◽  
First Order ◽  
Half Maximum Intensity

Assessment of Fatigue Life for High-Temperature Pipeline Welds by Non-Destructive Method

2006 ◽  
Vol 326-328 ◽  
pp. 497-500
Author(s):  
Keun Bong Yoo ◽  
Hyun Sun Choi ◽  
Eui Hyun Kim ◽  
Sun Young Cho ◽  
Jae Hoon Kim
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Fatigue Damage ◽  
Maximum Intensity ◽  
Life Assessment ◽  
Full Width ◽  
Half Maximum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Half Maximum Intensity

The objective of this study is to estimate the feasibility of X-ray diffraction method application for fatigue life assessment of the high-temperature pipeline steel such as main steam pipe, re-heater pipe and header etc. in power plant. In this study, X-ray diffraction tests using various types of specimen simulated low cycle fatigue damage were performed in order to analyze fatigue properties when fatigue damage conditions become various stages such as 1/4, 1/2 and 3/4 of fatigue life, respectively. As a result of X-ray diffraction tests for specimens simulated fatigue damages, we conformed that the variation of the full width at half maximum intensity decreased in proportion to the increase of fatigue life ratio. And also, the ratio of the full width at half maximum intensity due to fatigue damage has linear relationship with fatigue life ratio algebraically. From this relationship, it was suggested that direct expectation of the life consumption rate was feasible.

Numerical conversion between the Pearson VII and pseudo-Voigt functions

2005 ◽  
Vol 38 (5) ◽  
pp. 830-832 ◽  
Author(s):  
Hejing Wang ◽  
Jian Zhou
Keyword(s):  
Numerical Model ◽  
Numerical Solution ◽  
Maximum Intensity ◽  
Full Width ◽  
Half Maximum ◽  
Error Level ◽  
X Ray ◽  
Shape Coefficient ◽  
Integral Width ◽  
Half Maximum Intensity

The shape coefficient of a curve, which is defined as the ratio of its full width at half-maximum intensity to integral width, is a measure of variation in shape. From the definitions of the pseudo-Voigt, Pearson VII and Voigt functions used in X-ray diffractometry, three shape-converting formulae are deduced. Numerical solution helps to establish a numerical model for interconverting the shapes of the pseudo-Voigt, Pearson VII and Voigt functions. Assessment of the error level and some comments on the shape of the pseudo-Voigt and Pearson VII functions are thereby made.

An Analysis of the Effect of Different Instrumental Conditions on the Shapes of X-ray Powder Line Profiles

1994 ◽  
Vol 38 ◽  
pp. 75-82 ◽  
Author(s):  
R. W. Cheary ◽  
J. P. Cline
Keyword(s):  
Reference Material ◽  
Maximum Intensity ◽  
Full Width ◽  
Half Maximum ◽  
Line Profiles ◽  
Powder Specimen ◽  
Divergent Beam ◽  
X Ray ◽  
Half Maximum Intensity ◽  
Soller Slit

Abstract In this investigation we have examined how the full width at half maximum intensity (FWHM) and asymmetry of x-ray powder diffraction line profiles are influenced by the instrumental conditions adopted. Experimental x-ray data has been collected for a matrix of instrumental conditions by systematically varying the divergence slit angle (and the corresponding anti-scatter slit) over the range 0.25° to 1.25°, by using either a 0.05mm or 0.2mm receiving slit, or by removing the diffracted beam Soller slit. The line profile Standard Reference Material, SRM, 660 (LaB6) was used as the powder specimen in that it imparts minimal specimen induced broadening to the diffraction profiles. X-ray data were collected on a conventional, divergent beam, x-ray diffractometer using CuKα radiation. The FWHM of the CuKα1 component can be as low as 0.035°2θ for high resolution conditions, but is normally ∼0.1°2θ at 2θ ≈ 30° for the instrumental conditions adopted in routine diffractometry. Below 2θ = 50°, the divergence slit has a significant effect on the FWHM and is the major cause of the increase in FWHM with decreasing 2θ. Results are presented of the 2θ dependence of FWHM values for each of the instrumental conditions recorded. A general relationship for the 2θ dependence of the FWHM and the asymmetry has been investigated to supersede the inappropriate Cagliotti expression frequently used in x-ray Rietvcld refinement.

scholarly journals Effect of Heating Rate on the Responses of LiF: Mg, Cu, Na, Si Thermoluminescent Phosphor

2011 ◽  
Vol 21 (1) ◽  
pp. 43 ◽  
Author(s):  
Vu Thi Thai Ha ◽  
Nguyen Thi Quy Hai ◽  
Nguyen Ngoc Long
Keyword(s):  
Heating Rate ◽  
Peak Height ◽  
Glow Peak ◽  
Maximum Temperature ◽  
Full Width ◽  
Half Maximum ◽  
Temperature Peak ◽  
Heating Rates ◽  
First Order ◽  
Area Increase

In the current work the glow curves for LiF:Mg,Cu,Na,Si thermoluminescent material were measured and analyzed by using a function approximating to the well-known Randall-Wilkins first-order expression. The influence of different heating rates on thermoluminescent glow-peak maximum temperature, peak height and integrated area of the glow peak was investigated for LiF:Mg,Cu,Na,Si phosphor. The results show that the glow-peak temperature, peak height and glow peak area increase with increasing heating rate, while the full width at half maximum of glow peak almost keeps constant in the range of heating rates studied.

Non-Polar SiC Crystal Growth with m-Plane(1-100) and a-Plane(11-20) by PVT Method

2010 ◽  
Vol 645-648 ◽  
pp. 37-40
Author(s):  
Im Gyu Yeo ◽  
Tae Woo Lee ◽  
Won Jae Lee ◽  
Byoung Chul Shin ◽  
Il Soo Kim ◽  
...  
Keyword(s):  
Raman Spectrum ◽  
Crystal Growth ◽  
Carrier Concentration ◽  
Basal Plane ◽  
Stacking Faults ◽  
Full Width ◽  
Half Maximum ◽  
Etch Pits ◽  
Koh Etching

The present research was focused to produce 2 inch wafers from small rectangular seeds and to investigate the quality of non-polar SiC substrates grown by a conventional PVT method. The non-polar SiC seeds were prepared by cutting along <0001> direction of 6H-SiC crystal grown on (0001) basal plane. As SiC ingot grows, many defects in connected region were gradually diminished. While the full width at half maximum (FWHM) values of m-plane SiC substrate measured along a-direction and c-direction were 60 arcsec and 70 arcsec, respectively, and the FWHM values of a-plane SiC substrate measured along m-direction and c-direction were 27 arcsec and 31 arcsec respectively. The stacking faults lying in the basal plane can be detected by molten KOH etching as linear etch pits extending along <0001> on the (11-20) surface and the carrier concentration was observed by Raman spectrum.

RAMAN SPECTROSCOPY OF TEMPERATURE INDUCED EFFECTS IN FOUR CARBON ALLOTROPES

2013 ◽  
Vol 27 (28) ◽  
pp. 1350203 ◽  
Author(s):  
M. R. JOYA ◽  
A. R. ZANATTA ◽  
J. BARBA-ORTEGA
Keyword(s):  
Raman Spectrum ◽  
Raman Spectra ◽  
Carbon Nanoparticles ◽  
Structural Disorder ◽  
Full Width ◽  
Half Maximum ◽  
Temperature Dependent ◽  
Carbon Allotropes ◽  
20 Nm ◽  
Scanning Electron

In this paper, we report strong variations in the Raman spectra of different carbon allotropes samples, for temperatures ranging from 83 K to 1123 K. The temperature dependence of D and G peak frequencies in the Raman spectrum of diamond, graphite, graphene, and carbon nanoparticles (CNPs) with 20 nm dot-size were investigated. These effects caused by temperature can be estimated from the changes in position [Formula: see text] and in linewidth of peak full width at half maximum (FWHM) G in the Raman spectrum of each sample. The broadening for each allotrope under the same conditions of temperature were: diamond ~ 4 cm-1, graphite ~ 50 cm-1, graphene ~ 5 cm-1 and nanoparticles ~ 7 cm-1. We also used scanning electron microscopy (SEM) to study the morphology and determine the size of the samples. According to the experimental data, the residual structural disorder and stress present in the samples are enhanced with temperature and responds for the observed changes in the Raman spectra. We present a systematic study of the temperature-dependent Raman spectra of four carbon allotropes.

scholarly journals Spectroscopic Studies of Laser-Based Far-Ultraviolet Plasma Light Source

2021 ◽  
Vol 11 (15) ◽  
pp. 6919
Author(s):  
Majid Masnavi ◽  
Martin Richardson
Keyword(s):  
Dense Plasma ◽  
Wavelength Region ◽  
Spectroscopic Studies ◽  
Radiation Hydrodynamics ◽  
Full Width ◽  
Half Maximum ◽  
Laser Plasmas ◽  
Series Of Experiments ◽  
Far Ultraviolet ◽  
Radiation Conversion

A series of experiments is described which were conducted to measure the absolute spectral irradiances of laser plasmas created from metal targets over the wavelength region of 123–164 nm by two separate 1.0 μm lasers, i.e., using 100 Hz, 10 ns, 2–20 kHz, 60–100 ns full-width-at-half-maximum pulses. A maximum radiation conversion efficiency of ≈ 3%/2πsr is measured over a wavelength region from ≈ 125 to 160 nm. A developed collisional-radiative solver and radiation-hydrodynamics simulations in comparison to the spectra detected by the Seya–Namioka-type monochromator reveal the strong broadband experimental radiations which mainly originate from bound–bound transitions of low-ionized charges superimposed on a strong continuum from a dense plasma with an electron temperature of less than 10 eV.

scholarly journals Time to peak and full width at half maximum in MR perfusion: valuable indicators for monitoring moyamoya patients after revascularization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam Huang ◽  
Chung-Wei Lee ◽  
Hon-Man Liu
Keyword(s):  
Study Data ◽  
Unknown Etiology ◽  
Dynamic Susceptibility ◽  
Full Width ◽  
Half Maximum ◽  
Mr Perfusion ◽  
Dynamic Susceptibility Contrast ◽  
Time To Peak ◽  
Mr Perfusion Imaging ◽  
Outcome Monitoring

AbstractMoyamoya disease (MMD) is a chronic, steno-occlusive cerebrovascular disorder of unknown etiology. Surgical treatment is the only known effective method to restore blood flow to affected areas of the brain. However, there are lack of generally accepted noninvasive tools for therapeutic outcome monitoring. As dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) is the standard MR perfusion imaging technique in the clinical setting, we investigated a dataset of nineteen pediatric MMD patients with one preoperational and multiple periodic DSC MRI examinations for four to thirty-eight months after indirect revascularization. A rigid gamma variate model was used to derive two nondeconvolution-based perfusion parameters: time to peak (TTP) and full width at half maximum (FWHM) for monitoring transitional bolus delay and dispersion changes respectively. TTP and FWHM values were normalized to the cerebellum. Here, we report that 74% (14/19) of patients improve in both TTP and FWHM measurements, and whereof 57% (8/14) improve more noticeably on FWHM. TTP is in good agreement with Tmax in estimating bolus delay. Our study data also suggest bolus dispersion estimated by FWHM is an additional, informative indicator in pediatric MMD monitoring.

Preparation of highly c-axis oriented AlN thin films on Hastelloy tapes with Y2O3 buffer layer for flexible SAW sensor applications

2016 ◽  
Vol 09 (02) ◽  
pp. 1650023 ◽  
Author(s):  
Bin Peng ◽  
Jianying Jiang ◽  
Guo Chen ◽  
Lin Shu ◽  
Jie Feng ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Smooth Surface ◽  
Piezoelectric Coefficient ◽  
Piezoelectric Properties ◽  
Mean Square ◽  
Full Width ◽  
Half Maximum ◽  
Sensor Applications ◽  
Saw Sensor ◽  
Y2o3 Buffer Layer

Highly c-axis oriented aluminum nitrade (AlN) films were successfully deposited on flexible Hastelloy tapes by middle-frequency magnetron sputtering. The microstructure and piezoelectric properties of the AlN films were investigated. The results show that the AlN films deposited directly on the bare Hastelloy substrate have rough surface with root mean square (RMS) roughness of 32.43[Formula: see text]nm and its full width at half maximum (FWHM) of the AlN (0002) peak is [Formula: see text]. However, the AlN films deposited on the Hastelloy substrate with Y2O3 buffer layer show smooth surface with RMS roughness of 5.46[Formula: see text]nm and its FWHM of the AlN (0002) peak is only [Formula: see text]. The piezoelectric coefficient d[Formula: see text] of the AlN films deposited on the Y2O3/Hastelloy substrate is larger than three times that of the AlN films deposited on the bare Hastelloy substrate. The prepared highly c-axis oriented AlN films can be used to develop high-temperature flexible SAW sensors.

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