scholarly journals Self-absorption Correction Factors: Applying A Simplified Method to Analysis of Lead-210 in Different Environment Samples by Direct Counting of Low-energy Using HPGe Detector

2021 ◽  
Vol 240 ◽  
pp. 03002
Author(s):  
Jawaher Al-Tuweity ◽  
Hassan Kamleh ◽  
M. Said Al-Masri ◽  
A. Wael Doubal ◽  
El Mahjoub Chakir
Keyword(s):  
Chemical Composition ◽  
Gamma Spectroscopy ◽  
Direct Analysis ◽  
The Self ◽  
Correction Factors ◽  
Plant Samples ◽  
Absorption Correction ◽  
Density Factor ◽  
The Difference ◽  
Lead 210

This study aimed to determine the self-absorption correction factors of lead-210 (210Pb) in various Syrian environment samples. Seven sediments, five soils, and four plant samples were analysed by Gamma Spectroscopy using simple and direct analysis method called Cutshall. The method is based on measuring the penetration of gamma which emitted from a standard source, prepared in the laboratory by deposition of QCYB40 Standard Solution on stainless steel disk. The source was placed on top of the studied sample and the reference air sample during the measurement. The purpose was to study the self-absorption inside each sample by calculation of its self-absorption factors without knowing its chemical composition. The self-absorption correction results for the sediment samples SE3, SE6 and SE8 ranged between 36% and 45%, and 34% to 42% for the soil samples S5 and S1, respectively. Also, for the four plant samples, it recorded variance range from 4% to 18%. This is due to the difference in the density of the G4 sample, which appeared to be very low. However, the self-absorption correction factors CF were set for the different environmental samples, and the results show that the density factor of the sample is not the only influent factor in the CF values for low energies measurement, the sample chemical composition (sample matrix) is also more effective in addition to the samples’ particle sizes.

scholarly journals Determination of correction factor of self-absorption for lead-210 in environment samples using spike method

2021 ◽  
Vol 234 ◽  
pp. 00051 ◽  
Author(s):  
Jawaher Al-Tuweity ◽  
Hassan Kamleh ◽  
M. Said Al-Masri ◽  
A.Wael Doubal ◽  
Azougagh Mohamed ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Gamma Spectroscopy ◽  
Atomic Energy Commission ◽  
Low Energy ◽  
Influential Factor ◽  
Correction Factors ◽  
Sediment Samples ◽  
Absorption Correction ◽  
Density Factor ◽  
Lead 210

In environment radiation measurement, calculation the correction factors are critical, especially for low energy measurement because of self-absorption phenomena. In this work the main purpose is to determination the self-absorption correction factors of lead-210 (210Pb) energy (46.5keV) in various environment samples (7 sediments, 5 soil) using an experimental method called Spike Method. The samples were collecting from different places in Syrian. They were prepared according to the laboratory producers starting from collecting, cleaning, drying, grounding, hemogenic and calculating the appearance density. Low-energy gamma spectroscopy HPGe was used for radiation analysis which available at the laboratories of the Protection and Safety Department - Syrian Atomic Energy Commission – Syria. The spike method depends on adding a quantity of a standard solution with a known activity which contains lead isotope 210Pb and added to the studied samples. Self-absorption correction factors (CF) calculated by the ratio of the count rate or activity of spiked and unspiked samples. The CF for sediment samples were between 29% to 54% and for soil samples, the CFs were between 38% to 56% recording correction higher than sediment samples. The results showed a relatively high self-absorption and CFs values because of the chemical composition changeable between the spiked and unspiked samples. For that, it is better to adopt other methods less expensive, give results faster, higher accuracy and do not make change in the chemical composition. The results were also showed the density factor is the most influential factor in self-absorption phenomena.

scholarly journals Study of the Effects of Marble Powder Amount on the Self-Compacting Concretes Properties by Microstructure Analysis on Cement-Marble Powder Pastes

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Rayed Alyousef ◽  
Omrane Benjeddou ◽  
Mohamed Amine Khadimallah ◽  
Abdeliazim Mustafa Mohamed ◽  
Chokri Soussi
Keyword(s):  
Compressive Strength ◽  
Chemical Composition ◽  
High Specific Surface Area ◽  
The Self ◽  
Microstructure Analysis ◽  
X Ray Diffraction ◽  
Fresh State ◽  
Mineral Components ◽  
Marble Powder ◽  
The Difference

The marble powder (MP), obtained from waste sludge marble processing, has a high specific surface area; this could mean that it can be used as filler added to self-compacting concrete (SCC). The aim of this experimental work is to study the effects of the cement-MP paste volume on the rheology in the fresh state and the hardened properties (compressive strength) of SCC by a microstructure analysis on paste samples with different amounts of MP. For all pastes, the morphological forms and the chemical composition of the main mineral components were analyzed by the scanning electron microscope (SEM) and X-ray diffraction (XRD). The hydration, microstructure, and mineralogical changes has been studied. Experimental results show that the cement-MP paste volume has significant effects on the self-compacting and the self-leveling properties in the fresh state of SCC. In addition, the paste volume has a significant contribution on the compressive strength of SCC. Results indicate also that the difference in chemical composition between MP and cement have not any contribution on the paste volume effects.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

I Like Her, Because I Like Myself: Self-Evaluation as a Source of Interpersonal Attitudes

2003 ◽  
Vol 50 (4) ◽  
pp. 239-246 ◽  
Author(s):  
Eva Walther ◽  
Claudia Trasselli
Keyword(s):  
Opposite Effect ◽  
Learning Phase ◽  
The Self ◽  
Attitude Formation ◽  
Formation Processes ◽  
False Feedback ◽  
Self Evaluation ◽  
Evaluation Group ◽  
Group A ◽  
The Difference

Abstract. Two experiments tested the hypothesis that self-evaluation can serve as a source of interpersonal attitudes. In the first study, self-evaluation was manipulated by means of false feedback. A subsequent learning phase demonstrated that the co-occurrence of the self with another individual influenced the evaluation of this previously neutral target. Whereas evaluative self-target similarity increased under conditions of negative self-evaluation, an opposite effect emerged in the positive self-evaluation group. A second study replicated these findings and showed that the difference between positive and negative self-evaluation conditions disappeared when a load manipulation was applied. The implications of self-evaluation for attitude formation processes are discussed.

Kunst als reflexive Form und als reflektierende Bewegung

2010 ◽  
Vol 55 (2) ◽  
pp. 75-86
Author(s):  
Brigitte Hilmer
Keyword(s):  
Propositional Content ◽  
The Self ◽  
Aesthetic Judgement ◽  
The Difference ◽  
Self Reference

Kunst kann dann als reflexiv interpretiert werden, wenn Reflexivität nicht auf propositionalen Gehalt oder sogar sprachliche Artikulation angewiesen ist. Reflexion tritt auf in den Modi der Selbstbeziehung des Lebendigen, des Überlegens und der Selbstreferenz im Symbolischen. Kunst ist ein Reflexionsmedium, das diese Modi beansprucht und miteinander verflicht. Eine spezifisch ästhetische Reflexivität ist von und nach Kant nach dem Vorbild der transzendentalen Reflexion und in Konkurrenz zu ihr etabliert worden. Sie läßt sich als Reflexivität des ästhetischen Urteils, als emphatisches Gemachtsein, als Rückwendung auf Wahrnehmungsvollzüge oder als Begriffsreflexion verstehen. Dabei wird die Unterscheidung von Anschauung und Verstand in deren Zusammenspiel oder Abspaltung vorausgesetzt. Von der Analogie zur transzendentalen Reflexion löst sich aber erst ein Verständnis von ästhetischer Reflexivität, das von den drei Modi und ihrer Verflechtung ausgeht.<br><br>Reflexivity does not presuppose linguistic articulation or even propositional content. If it did, art could not be called reflexive. Reflexivity can be found in the self-contact of the living, in mental reflection or in symbolic self-reference. Art is a medium which claims these different modes of reflexivity and intertwines them. Aesthetic reflexivity as such has been established by Kant and his epigones, following the model of transcendetal reflection. Thus it could be specified as the reflexive structure of aesthetic judgement, or as an emphasis on a work’s being created, or as a reference to perception itself in the process of perceiving, or as a way of reflecting concepts. Aesthetic reflexivity can only be detached from the model of transcendental reflection, if it is seen as oriented towards the interaction among the three modes of reflection mentioned above, leaving aside the difference, interplay or competition between perception and conceptual capacities.

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