scholarly journals Evaluation of uncertainty in the energy dispersive X-ray fluorescence determination of platinum in alumina

2015 ◽  
Vol 7 (12) ◽  
pp. 5345-5351 ◽  
Author(s):  
P. S. Remya Devi ◽  
A. C. Trupti ◽  
A. Nicy ◽  
A. A. Dalvi ◽  
K. K. Swain ◽  
...  
Keyword(s):  
Least Squares ◽  
Energy Dispersive ◽  
Weighted Regression ◽  
Calibration Function ◽  
X Ray ◽  
Least Squares Fitting ◽  
Fluorescence Determination ◽  
Analytical Result ◽  
Fitting In

Uncertainty, the most important characteristic of an analytical result, has been evaluated using a bottom-up approach during EDXRF determination of Pt in alumina. The calibration function of the EDXRF spectrometer was derived through bivariate least squares fitting, in combination with weighted regression of the residuals.

scholarly journals Experimental Determination of Scan-truncation Losses from Low-temperature (16 K) Single-crystal X-ray Measurements

1988 ◽  
Vol 41 (3) ◽  
pp. 503 ◽  
Author(s):  
Riccardo Destro
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Experimental Determination ◽  
Least Squares ◽  
Spectral Distribution ◽  
Experimental Measurements ◽  
Fourier Methods ◽  
X Ray ◽  
Least Squares Fitting

Model intensity profiles have been obtained for biscarbonyl[ 14]annulene by convoluting the Mo Ka spectral distribution with two functions derived from experimental measurements at 16(1) K, up to 26Mo = 110�, of a spherical crystal mounted on a four-circle diffractometer equipped with the Samson low-temperature apparatus. The process includes accurate measurement of the inherent background, treatment of the profiles by numerical Fourier methods, and least-squares fitting. Owing to the instrumental configuration of the diffractometer used in this investigation, the first step of the process has required a careful determination of the X dependence of the background, besides the usual 26 dependence. Truncation losses for the crystal under study, evaluated for several scan ranges, are far larger than usually assumed or predicted.

scholarly journals Least squares curve fitting in Mo3d X-ray photoelectron spectra for determination of oxidation states of supported molybdenum catalysts.

1989 ◽  
Vol 38 (2) ◽  
pp. 65-71
Author(s):  
Natsuo FUKUMOTO ◽  
Isao KOJIMA ◽  
Masayasu KURAHASHI ◽  
Hiromichi SHIMADA ◽  
Akio NISHIJIMA
Keyword(s):  
Least Squares ◽  
Curve Fitting ◽  
Photoelectron Spectra ◽  
Oxidation States ◽  
X Ray ◽  
Molybdenum Catalysts ◽  
Least Squares Curve Fitting ◽  
Fitting In

An X-ray determination of the thermal expansion of the intermetallic compound Ni3Zr

1983 ◽  
Vol 16 (6) ◽  
pp. 645-646 ◽  
Author(s):  
S. K. Shadangi ◽  
S. C. Panda ◽  
S. Bhan
Keyword(s):  
Thermal Expansion ◽  
Intermetallic Compound ◽  
Least Squares ◽  
Temperature Interval ◽  
X Ray ◽  
Least Squares Fitting ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Ray Methods

The lattice spacings of the intermetallic compound Ni3Zr have been measured by X-ray methods in the temperature interval 298–1033 K using a Debye–Scherrer camera. In all the cases the measured lattice spacings have been found to increase non-linearly with temperature and the dependence has been expressed by a polynomial of second degree from the least-squares fitting of the data. The thermal expansion coefficients for both parameters have been found to decrease with increase in temperature.

Partial least squares X-ray fluorescence determination of trace elements in sediments from the estuary of Nerbioi-Ibaizabal River

Talanta ◽  
2010 ◽  
Vol 82 (4) ◽  
pp. 1254-1260 ◽  
Author(s):  
Javier Moros ◽  
Ainara Gredilla ◽  
Silvia Fdez-Ortiz de Vallejuelo ◽  
Alberto de Diego ◽  
Juan Manuel Madariaga ◽  
...  
Keyword(s):  
Trace Elements ◽  
Least Squares ◽  
Partial Least Squares ◽  
X Ray ◽  
Fluorescence Determination
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