1,721,035 research outputs found
Radiation protective characteristics of some selected tungstates
No full textAkman, Ferdi/0000-0002-8838-1762WOS: 000462019200007The mass attenuation coefficients (mu/rho) of calcium tungstate, ammonium tungsten oxide, bismuth tungsten oxide, lithium tungstate, cadmium tungstate, magnesium tungstate, strontium tungsten oxide and sodium dodecatungstophosphate hydrate were measured at 14 photon energies in the energy range of 81-1333 keV using Na-22,Mn-54,Co-57,Co-60,Ba-133 and( 137)Cradioactive sources. The measured gip values were compared with those obtained from WinXCOM program and the differences between the experimental and theoretical values were very small. The bismuth tungsten oxide has the highest mu/rho among the present samples in the studied energy region. From the mu/rho values, we calculated the half value layer, tenth value layer and mean free path, and the results showed that ammonium tungsten oxide (which has the lowest density) and bismuth tungsten oxide (which has the highest density) possess the highest and lowest values of these three parameters, respectively. Additionally, from the incident and transmitted photon intensities, we calculated the radiation protection efficiency (RPE). The bismuth tungsten oxide was found to have RPE 98.53 % at 81 keV, which has the maximum value among the present samples and this suggested that bismuth tungsten oxide is the best to be chosen as the y radiation shielding material candidate among the selected samples
Investigation of radiation shielding properties for some ceramics
No full textAkman, Ferdi/0000-0002-8838-1762WOS: 000457480900009In this work, the radiation shielding parameters like mass and linear attenuation coefficient, half value layer, tenth value layer, mean free path, effective atomic number, effective electron density, exposure buildup factor and fast neutron removal cross section were examined for the peridot, aluminum nitride, ruby, yttrium oxide, magnesium silicate, and silicon nitride ceramic samples. Furthermore, the dependence of the effective conductivity on the energy was investigated. The experimental studies were carried out in the photon energy range of 81 keV-1333 keV using a high resolution HPGe detector and six different radioactive sources. The experimental results were validated with the theoretical results and a good agreement was observed for all samples. The yttrium oxide has more shielding effectiveness for y radiation, while magnesium silicate, aluminum nitride and silicon nitride possess least y-ray shielding. However, the optimum neutron shielding material is ruby.Scientific Research Projects Coordination Unit of Giresun University [FEN-BAP-A-160317-23]This paper was produced from the project (number: FEN-BAP-A-160317-23) supported by The Scientific Research Projects Coordination Unit of Giresun University
Measurements of K X-ray fluorescence cross-sections, fluorescence yields, level widths and radiative vacancy transition probabilities for the elements Zr, Mo, Cd, Er at 59.54 keV
No full text1st International Conference on Material Engineering and Advanced Manufacturing Technology ((MEAMT) -- AUG 25-27, 2017 -- Busan, SOUTH KOREADURAK, RIDVAN/0000-0002-3935-176X; Akman, Ferdi/0000-0002-8838-1762WOS: 000426772700015K shell X ray fluorescence cross sections, fluorescence yields, level widths and radiative vacancy transition probabilities were investigated for the elements Zr, Mo, Cd, Er. The measurements were performed using photons of 59.54 keV emitted from an Am-241 (about 100 mCi) point source and a high resolution Si(Li) detector. The experimental results were compared with theoretical calculations and the other results obtained from literature
Updated Database for K-Shell Fluorescence Yields
No full text2nd International Conference on Advances in Natural and Applied Sciences (ICANAS) -- APR 18-21, 2017 -- Antalya, TURKEYDURAK, RIDVAN/0000-0002-3935-176X; Akman, Ferdi/0000-0002-8838-1762WOS: 000405093100090This study presents a summary of experimental data of K-shell fluorescence yields (omega(K)) published in the period of time between 2010 to february-2017. The fluorescence yields (omega(K)) of elements in the range 23 <= Z <= 60 taken directly from different sources were reviewed and presented in a table form. Finally, the experimental and empirical values in the literature have been reported and commented.Agri Ibrahim Cecen Univ, IC Fd
K to L shell vacancy transfer probabilities and Auger electron emission ratios for elements in the atomic range 30 ≤ Z ≤ 58
No full textThe K to L shell vacancy transfer probabilities for some elements in the atomic range 30 ≤ Z ≤ 58 were determined using the semi-empirical values of K shell fluorescence yield and the experimental values of Kβ/Kα X-ray intensity ratio. Furthermore, the KLX/KLL and KXY/KLL Auger electrons emission ratios for the same elements were obtained using the experimental values of Kβ/Kα X-ray intensity ratio. The experiments were performed using a 241Am annular radioisotope source and a high-resolution Si(Li) semiconductor detector. The experimental values of K to L shell vacancy transfer probabilities, and KLX/KLL and KXY/KLL Auger electrons emission ratios were compared with the fitted, theoretical, semi-empirical, and other available experimental values. To the best knowledge of the author, the KLX/KLL and KXY/KLL Auger electrons emission ratios of ruthenium, palladium, and tellurium have been obtained for the first time in the present work
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Determination of some selected absorption parameters for Cd, La and Ce elements
No full textDURAK, RIDVAN/0000-0002-3935-176X; Akman, Ferdi/0000-0002-8838-1762WOS: 000460717500014The total atomic attenuation cross-section values in the energy region from 14.932 to 57.142 keV were determined to obtain completely experimental values of the K shell absorption edge energies for Cd, La and Ce elements. The photoelectric cross-sections in the aforementioned energy range, K shell photoelectric cross-sections at the K edge, K shell absorption jump ratios, K shell absorption jump factors and K shell oscillator strength values were obtained with the help of the total atomic attenuation cross-sections. The measurements were performed using the secondary excitation geometry including a high resolution Si(Li) detector. 59.54 keV photon energy emitted from the Am-241 annular radioactive source was used as the primary source. The K shell characteristic X-ray energies of the some selected elements between Y and Er were used as the secondary source. The obtained experimental results were checked with the theoretical and other available experimental results, and it was observed that there is a good agreement between them
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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