ERROR PROPAGATION OF THE UNCERTAINTY IN VARIOUS PARAMETERS TO THE UNCERTAINTY IN THE PRIMARY PIXE YIELD AND SECONDARY FLUORESCENCE YIELD

1993 ◽  
Vol 03 (02) ◽  
pp. 145-176 ◽  
Author(s):  
F. MUNNIK ◽  
P.H.A. MUTSAERS ◽  
E. ROKITA ◽  
M.J.A. de VOIGT
Keyword(s):  
Relative Error ◽  
Numerical Approach ◽  
Fluorescence Yield ◽  
Matrix Composition ◽  
X Ray ◽  
Propagation Factor ◽  
Proton Beam Energy ◽  
Primary Yield ◽  
The Matrix ◽  
Secondary Fluorescence

In this article the uncertainty in the PIXE yield due to the uncertainty in various parameters such as the ionization cross section, the stopping power, the X-ray attenuation coefficient, the matrix composition and the proton beam energy, is discussed. This is done for both the primary PIXE and the secondary fluorescence yield. A numerical approach to the propagation of an uncertainty in a parameter to the uncertainty in the yield is given. For this a new parameter, the propagation factor, which is the partial relative error in the yield due to the error in a parameter divided by the relative error in the parameter, is introduced. The dependence of the propagation factor on the X-ray and proton energies and or the matrix composition is investigated for the above named parameters. The physical background of these dependencies is explained; this also makes it possible to obtain a better physical insight in the formulas for the primary yield and the secondary fluorescence yield.

The Application of Bio-Standards for Electron Energy-Loss Analysis of Biological Materials

1990 ◽  
Vol 48 (2) ◽  
pp. 68-69
Author(s):  
Wim C. de Bruijn ◽  
Lianne W.J. Sorber
Keyword(s):  
Ion Exchange ◽  
Energy Loss ◽  
Electron Energy ◽  
Matrix Composition ◽  
Cell Organelles ◽  
X Ray ◽  
Loss Analysis ◽  
The Matrix ◽  
Electron Energy Loss

The application of standards, with a known externally determined element concentration, for the determination of unknown concentrations in cell organelles and tissue is a well known practice in X-ray microanalysis.The conditions to be met for a good standard have been formulated earlier. Pure element standards and standards made from PVP-films have been proposed for Electron Energy loss analysis. In this presentation we investigate the use for EELS-analysis of the ion-exchange bead Chelex100-type of standards, which can be co-embedded with tissue and have been applied successfully for X-ray microanalysis.The ion-exchange characteristics, the methods of loading and the matrix composition have been described before. Such bio-standards, which can be loaded with a variety of cations, are stored as a dry powder and can be co-embedded with the tissue to be analyzed. In that way the standard is present in each ultrathin section, at (an assumed) equal thickness as the cells or tissue, containing the unknown concentration of that element.

scholarly journals Hydration Patterns in Sodium Alginate Polymeric Matrix Tablets—The Result of Drug Substance Incorporation

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6531
Author(s):  
Ewelina Juszczyk ◽  
Piotr Kulinowski ◽  
Ewelina Baran ◽  
Artur Birczyński ◽  
Jolanta Klaja ◽  
...  
Keyword(s):  
Sodium Alginate ◽  
Sodium Salicylate ◽  
Matrix Tablets ◽  
Matrix Composition ◽  
Scanning Calorimetry ◽  
Karl Fischer Titration ◽  
X Ray ◽  
Internal Part ◽  
Lamellar Region ◽  
The Matrix

The purpose was to show, using destructive/nondestructive methods, that the interplay between water, tablet structure, and composition determine the unique spatiotemporal hydration pattern of polymer-based matrices. The tablets containing a 1:1 w/w mixture of sodium alginate with salicylic acid (ALG/SA) or sodium salicylate (ALG/SNA) were studied using Karl Fischer titration, differential scanning calorimetry, X-ray microtomography, and magnetic resonance imaging. As the principal results, matrix specific features were detected, e.g., “locking” of the internal part of the matrix (ALG/SA); existence of lamellar region associated with detection of free/freezing water (ALG/SA); existence of water penetrating the matrix forming specific region preceding infiltration layer (ALG/SNA); switch in the onset temperature of endothermic water peak associated with an increase in the fraction of non-freezing water weight per dry matrix weight in the infiltration layer (ALG/SNA). The existence of complicated spatiotemporal hydration patterns influenced by matrix composition and molecular properties of constituents has been demonstrated.

Applicability of Pixe and XRF to Fast Drill Core Analysis in Air

1980 ◽  
Vol 24 ◽  
pp. 313-321
Author(s):  
Lars-Eric Carlsson ◽  
K. Roland Akselsson
Keyword(s):  
Detection Limits ◽  
Geological Sample ◽  
Matrix Composition ◽  
Core Analysis ◽  
Pixe Analysis ◽  
X Ray ◽  
Fundamental Parameters ◽  
Target Mode ◽  
The Matrix ◽  
Drill Cores

AbstractThe properties of particle-induced X-ray emission, PIXE, and secondary target mode X-ray fluorescence, XRF, applied to the analysis of unprepared drill cores in open air have been evaluated. Typical detection limits for elements heavier than Mg have been determined for a PIXE-system with an external 2.55 MeV proton beam and for an XRF-system with Ti, Mo and Tb secondary targets. These two systems were found to have similar detection limits for most elements in a typical geological sample. The heterogeneous composition of drill cores prevents the performance of accurate matrix corrections, though calculations using fundamental parameters show that in the PIXE analysis of elements heavier than Ca, these corrections are much less sensitive to variations in the matrix composition than in the XRF analysis.

scholarly journals Локальная структура и процессы гидратации галогензамещенных перовскитов на основе Ba-=SUB=-4-=/SUB=-In-=SUB=-2-=/SUB=-Zr-=SUB=-2-=/SUB=-O-=SUB=-11-=/SUB=-

2019 ◽  
Vol 126 (4) ◽  
pp. 419
Author(s):  
Н.А. Тарасова ◽  
А.О. Галишева ◽  
И.Е. Анимица
Keyword(s):  
Phase Composition ◽  
Single Phase ◽  
Matrix Composition ◽  
Halide Ions ◽  
X Ray Diffraction ◽  
Hydration Degree ◽  
Oh Groups ◽  
X Ray ◽  
Crystal Unit Cell ◽  
The Matrix

AbstractHalogen-substituted perovskites Ba_4In_2Zr_2O_10.95F_0.1 and Ba_4In_2Zr_2O_10.95Cl_0.1 are synthesized, and their single-phase composition is verified by X-ray diffraction analysis. Their ability of the studied phases to hydrate and form energetically unequal OH^– groups is proved. It is found that introduction of halide ions leads to a decrease in the hydration degree with respect to the matrix composition, which is explained by a decrease in the crystal unit cell free volume Processes.

X-ray spatial resolution in electron microbeam analysis

1991 ◽  
Vol 49 ◽  
pp. 462-463
Author(s):  
John T. Armstrong ◽  
Paul K. Carpenter
Keyword(s):  
Spatial Resolution ◽  
X Rays ◽  
X Ray ◽  
Excitation Potential ◽  
Sample Density ◽  
The Matrix ◽  
Backscattered Electron ◽  
X Ray Absorption ◽  
Critical Excitation ◽  
Secondary Fluorescence

The spatial resolution of characteristic x-ray production from electron bombardment in thick specimens is dependent upon the rate of energy loss of the primary electrons, the degree of electron scattering, the degree of x-ray absorption by the matrix, and the extent of secondary fluorescence of the x-rays by higher energy characteristic and continuum x-rays. The x-ray spatial resolution in thick specimens is much coarser than the secondary or backscattered electron resolution, typically being of the order of a fraction of a μm to several μm when secondary fluorescence is not significant, or as much as 100 to 200 μm when it is. The size of the excited volume of x-ray production is dependent upon the accelerating potential of the electron beam, the critical excitation potential, and the sample density. The size of the excited volumes of different elements’ x-ray lines can be considerably different in the same matrix, due to differences in critical excitation potential; the emitting volumes can vary even more, due to differences in mass absorption.

Hydride structures in Ti-aluminides subjected to high temperature and hydrogen pressure charging conditions

1991 ◽  
Vol 6 (6) ◽  
pp. 1230-1237 ◽  
Author(s):  
D. Legzdina ◽  
I.M. Robertson ◽  
H.K. Birnbaum
Keyword(s):  
Single Phase ◽  
Vacuum Annealing ◽  
Lattice Parameter ◽  
Matrix Composition ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
The Matrix ◽  
Diffraction Patterns ◽  
Fcc Structure

The distribution and chemistry of hydrides produced in single and dual phase alloys with a composition near TiAl have been investigated by using a combination of TEM and x-ray diffraction techniques. The alloys were exposed at 650 °C to 13.8 MPa of gaseous H2 for 100 h. In the single-phase gamma alloy, large hydrides preferentially nucleated on the grain boundaries and matrix dislocations and a population of small hydrides was distributed throughout the matrix. X-ray and electron diffraction patterns from these hydrides indicated that they have an fcc structure with a lattice parameter of 0.45 nm. EDAX analysis of the hydrides showed that they were enriched in Ti. The hydrides were mostly removed by vacuum annealing at 800 °C for 24 h. On dissolution of the hydrides, the chemistry of hydride-free regions of the grain boundary returned to the matrix composition, suggesting that Ti segregation accompanied the hydride formation rather than Ti enrichment causing the formation of the hydride. The hydrogen content in the two-phase (γ-α2) alloy was approximately three times that of the single phase alloy, which was presumably a consequence of the presence of the α2-Ti3Al phase in the two-phase alloy. The hydrides in the two-phase material were shown by x-ray diffraction to have an fcc structure and were removed on annealing in vacuum at 800 °C for 24 h.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

Analysis and lattice imaging of a transitional event on garnets

1978 ◽  
Vol 36 (1) ◽  
pp. 270-271
Author(s):  
J.Y. Laval
Keyword(s):  
Yttrium Iron Garnet ◽  
Reciprocal Lattice ◽  
Transitional Zone ◽  
Lattice Imaging ◽  
Yttrium Iron ◽  
X Ray ◽  
Ionic Process ◽  
The Matrix ◽  
High Resolution Technique ◽  
Iron Garnet

The exsolution of magnetite from a substituted Yttrium Iron Garnet, containing an iron excess may lead to a transitional event. This event is characterized hy the formation of a transitional zone at the center of which the magnetite nucleates (Fig.1). Since there is a contrast between the matrix and these zones and since selected area diffraction does not show any difference between those zones and the matrix in the reciprocal lattice, it is of interest to analyze the structure of the transitional zones.By using simultaneously different techniques in electron microscopy, (oscillating crystal method microdiffraction and X-ray microanalysis)one may resolve the ionic process corresponding to the transitional event and image this event subsequently by high resolution technique.

Phase identification in SiC whisker reinforced Al2O3-R2O3-based composites

1992 ◽  
Vol 50 (1) ◽  
pp. 152-153
Author(s):  
C.M. Sung ◽  
K.J. Ostreicher ◽  
M.L. Huckabee ◽  
S.T. Buljan
Keyword(s):  
Analytical Electron Microscopy ◽  
Phase Identification ◽  
Reinforced Composites ◽  
Ion Milling ◽  
X Ray ◽  
Binary Oxides ◽  
Analytical Electron ◽  
The Matrix ◽  
Second Phases ◽  
Convergent Beam

A series of binary oxides and SiC whisker reinforced composites both having a matrix composed of an α-(Al, R)2O3 solid solution (R: rare earth) have been studied by analytical electron microscopy (AEM). The mechanical properties of the composites as well as crystal structure, composition, and defects of both second phases and the matrix were investigated. The formation of various second phases, e.g. garnet, β-Alumina, or perovskite structures in the binary Al2O3-R2O3 and the ternary Al2O3-R2O3-SiC(w) systems are discussed.Sections of the materials having thicknesses of 100 μm - 300 μm were first diamond core drilled. The discs were then polished and dimpled. The final step was ion milling with Ar+ until breakthrough occurred. Samples prepared in this manner were then analyzed using the Philips EM400T AEM. The low-Z energy dispersive X-ray spectroscopy (EDXS) data were obtained and correlated with convergent beam electron diffraction (CBED) patterns to identify phase compositions and structures. The following EDXS parameters were maintained in the analyzed areas: accelerating voltage of 120 keV, sample tilt of 12° and 20% dead time.

Improving x-ray map resolution with image restoration techniques

1996 ◽  
Vol 54 ◽  
pp. 598-599
Author(s):  
Richard B. Mott ◽  
John J. Friel ◽  
Charles G. Waldman
Keyword(s):  
Image Restoration ◽  
Hubble Space Telescope ◽  
Extensive Literature ◽  
Small Object ◽  
X Rays ◽  
X Ray ◽  
Mapping Parameters ◽  
The Matrix ◽  
The 1960S ◽  
Map Resolution

X-rays are emitted from a relatively large volume in bulk samples, limiting the smallest features which are visible in X-ray maps. Beam spreading also hampers attempts to make geometric measurements of features based on their boundaries in X-ray maps. This has prompted recent interest in using low voltages, and consequently mapping L or M lines, in order to minimize the blurring of the maps.An alternative strategy draws on the extensive work in image restoration (deblurring) developed in space science and astronomy since the 1960s. A recent example is the restoration of images from the Hubble Space Telescope prior to its new optics. Extensive literature exists on the theory of image restoration. The simplest case and its correspondence with X-ray mapping parameters is shown in Figures 1 and 2.Using pixels much smaller than the X-ray volume, a small object of differing composition from the matrix generates a broad, low response. This shape corresponds to the point spread function (PSF). The observed X-ray map can be modeled as an “ideal” map, with an X-ray volume of zero, convolved with the PSF. Figure 2a shows the 1-dimensional case of a line profile across a thin layer. Figure 2b shows an idealized noise-free profile which is then convolved with the PSF to give the blurred profile of Figure 2c.

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