scholarly journals The Performance of PIXE Technique through a Geochemical Analysis of High Grade Rocks

2020 ◽  
Vol 7 (1) ◽  
pp. 13-28
Author(s):  
Venkata Surya Satyanarayana Avupati ◽  
M. Jagannadharao ◽  
K. Chandra Mouli ◽  
B. Seetaramireddy
Keyword(s):  
Poor Performance ◽  
Systematic Investigation ◽  
Geochemical Analysis ◽  
High Grade ◽  
Geological Material ◽  
Pixe Analysis ◽  
X Ray ◽  
The Matrix ◽  
Grade Rock ◽  
High Grade Rock

It has been an argument that some of the elements present in geological material by using PIXE analysis are purely determined or could not be determined at all, due to various reasons including the matrix. It is felt that a systematic investigation needs to be designed and implemented to understand the limitation of PIXE in certain elements. The high-grade rocks selected are analyzed both by PIXE as well as AAS and the results are authenticated by using a USGS reference material, Basalt, studies of literature. It is believed that the accuracy of problematic elements, especially from high grade rock can be improved and the conditions of PIXE can be standardized for various elements under different combinations. The reasons behind the poor performance of Proton Induced X- ray Emission in case of certain elements have been established.

A ceramic composite derived from high-grade rock phosphate as a substitution for human bone

2019 ◽  
Vol 34 (12) ◽  
pp. 743-750
Author(s):  
Kalinga Hapuhinna ◽  
Rajitha Deshapriya Gunaratne ◽  
Jagath Pitawala
Keyword(s):  
Ceramic Composite ◽  
Rock Phosphate ◽  
Human Bone ◽  
High Grade ◽  
Grade Rock ◽  
High Grade Rock

scholarly journals Low Z Elements of High Grade Metamorphic Rocks by PIXE Analysis – A Comprehensive Review

2020 ◽  
Author(s):  
Avupati Venkata Surya Satyanarayana ◽  
Mokka Jagannadha Rao ◽  
Byreddy Seetharami Reddy
Keyword(s):  
Cross Section ◽  
Analytical Techniques ◽  
Thick Target ◽  
Light Energy ◽  
Low Energy ◽  
High Grade ◽  
X Rays ◽  
Pixe Analysis ◽  
X Ray ◽  
Line Intensities

Abstract. The majority of PIXE analytical study on geosciences has used 3 MeV proton beams for excitation and these studies generally uses the K-X-rays for low Z elements and L-X-rays for high Z elements. The present study of resulting spectra of metamorphic high grade rocks like charnockite can require striping techniques to resolve interference problems between low and high Z elements on the applications of light energy-PIXE using Si (Li) detector. In all forms of X-ray analysis, including thick-target light energy-PIXE, the X-ray signal is a dependent of the ionization cross section and for low-energy protons, the cross section is high for the K shells of light elements and the L shells of heavy elements in charnockite rock providing sufficient fluorescent yield for analytical purposes. For Z > 55, 3 MeV protons cannot ionize K-shell electrons and analysis depends on the use of L-X-ray lines in charnockite rock. Such L-X-ray spectra are complicated and can be affected by interferences K-X-rays from low Z elements. The low Z elements present in the charnockite were identified by previous complementary analytical techniques, but not identified in this study due to the above PIXE experiment limitations, and also particularly due to the dimensions of Si (Li) detector because of low energy K-X-rays of the elements absorbed by the detector window. Both interferences complexity and detector efficiency can lead to difficulties and ambiguity in the interpretation of spectra of low Z charnockite composition, a problem that is exacerbated by uncertainty in relative K-X-ray line intensities of low Z elements. From this investigation, the light energy-PIXE is ideal for the analysis of low Z 

Biochar of animal origin: a sustainable solution to the global problem of high-grade rock phosphate scarcity?

2013 ◽  
Vol 93 (8) ◽  
pp. 1799-1804 ◽  
Author(s):  
Nikolay Vassilev ◽  
Eva Martos ◽  
Gilberto Mendes ◽  
Vanessa Martos ◽  
Maria Vassileva
Keyword(s):  
Rock Phosphate ◽  
Animal Origin ◽  
High Grade ◽  
Global Problem ◽  
Grade Rock ◽  
High Grade Rock

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 High-grade deformation in quartzo-feldspathic gneisses during the early Variscan exhumation of the Cabo Ortegal nappe, NW of Iberia

2015 ◽  
Vol 7 (4) ◽  
pp. 3541-3586
Author(s):  
F. J. Fernández ◽  
S. Llana-Fúnez ◽  
A. Marcos ◽  
P. Castiñeiras ◽  
P. Valverde-Vaquero
Keyword(s):  
Partial Melting ◽  
Shear Bands ◽  
Shear Zones ◽  
High Grade ◽  
Nw Spain ◽  
Mafic Rocks ◽  
Planar Shear ◽  
Grade Rock ◽  
High Grade Rock ◽  
Strain Direction

Abstract. High-grade highly deformed gneisses crop out continuously along the Masanteo peninsula in the Cabo Ortegal nappe (NW Spain). The rock sequence formed by quartzo-feldspathic gneisses and mafic rocks records two partial melting events: during the Early Ordovician (ca. 480–488 Ma.), at the base of the Qz-Fsp gneisses, and immediately after eclogization (ca. 390.4 ± 1.2 Ma), during its early Variscan exhumation. Despite the strain accumulated during their final exhumation in which a pervasive blastomylonitic S2 foliation was developed, primary sedimentary layering in Qz-Fsp gneisses is well preserved locally at the top of the sequence. This first stage of the exhumation process occurred in ~ 10 Ma, during which bulk flattening of the high-grade rock sequence was accommodated by anastomosing shear bands that evolved to planar shear zones. Strain was progressively localized along the boundaries of the migmatitic Qz-Fsp gneisses. A SE-vergent ductile thrust constitutes the base of gneisses, incorporating eclogite blocks-in-matrix. A NW-vergent detachment placed the metasedimentary Qz-Fsp gneisses over the migmatitic Qz-Fsp gneisses. A difference in metamorphic pressure of ca. 0.5 GPa is estimated between both gneissic units. The high-grade deformation reduced substantially the thickness of the gneissic rock sequence during the process of exhumation controlled by change in the strain direction and the progressive localization of strain. The combined movement of the top detachment and basal thrust resulted in an extrusion of the migmatites within the nappe, directed to the SE in current coordinates.

XRF and PIXE Analysis of light and Dark Adapted Ocular Tissue

1982 ◽  
Vol 40 ◽  
pp. 190-191
Author(s):  
B. J. Panessa ◽  
H. W. Kraner ◽  
J. B. Warren ◽  
K. W. Jones
Keyword(s):  
Trace Metals ◽  
Pigment Epithelium ◽  
Nerve Impulse ◽  
Light Response ◽  
Ocular Tissue ◽  
Emission Spectrometry ◽  
Retinol Dehydrogenase ◽  
Pixe Analysis ◽  
X Ray ◽  
Optimal Function

During photoexcitation the retina requires specific electrolytes and trace metals for optimal function (Na, Mg, Cl, K, Ca, S, P, Cu and Zn). According to Hagins (1981), photoexcitation and generation of a nerve impulse involves the movement of Ca from the rhodopsin-ladened membranes of the rod outer segment (ROS) to the plasmalemma, which in turn decreases the in-flow of Na into the photoreceptor, resulting in hyperpolarization. In toad isolated retinas, the presence of Ba has been found to increase the amplitude and prolong the delay of the light response (Brown and Flaming, 1978). Trace metals such as Cu, Zn and Se are essential for the activity of the metalloenzymes of the retina and retina pigment epithelium (RPE) (i.e. carbonic anhydrase, retinol dehydrogenase, tyrosinase, glutathione peroxidase, superoxide dismutase...). Therefore the content and fluctuations of these elements in the retina and choroid are of fundamental importance for the maintenance of vision. This paper presents elemental data from light and dark adapted frog ocular tissues examined by electron beam induced x-ray microanalysis, x-ray fluorescence spectrometry (XRF) and proton induced x-ray emission spectrometry (PIXE).

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.

Sign in / Sign up

Export Citation Format

Share Document