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Kharfi F, Şahiner E, Benkhelifa CZ, Garoui A. Effect of IRSL-BLSL-TSL reading modes combination on thermoluminescence (TL) response of BeO dosimeter. LUMINESCENCE 2024; 39:e4755. [PMID: 38689564 DOI: 10.1002/bio.4755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/23/2024] [Accepted: 04/07/2024] [Indexed: 05/02/2024]
Abstract
The ultimate goal of this work is the study of the effect of luminescence stimulations and signals reading modes combinations on the thermoluminescence intensity and glow curve behaviour for the same X-ray irradiation dose. Three interesting stimulating and reading modes are considered, namely, infrared stimulated luminescence (IRSL), blue light-emitting diode stimulated luminescence (BLSL) and thermally stimulated luminescence (TSL). The studied stimulation and reading modes combination protocols are (Protocol 1) IRSL-TSL, (Protocol 2) IRSL-BLSL-TSL and (Protocol 3) BLSL-IRSL-TSL. Experiments are performed on beryllium oxide (BeO) dosimeter. Results demonstrate well that the combination of reading modes have direct impact on the TL signal in terms of intensity and glow curve shape. It was also found that when reading modes are correctly combined, particularly when IRSL is applied first, then BLSL and TL, it is possible to collect two or more exploitable signals of different stimulation types for the same irradiation that can be used for different purposes and final applications.
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Affiliation(s)
- Faycal Kharfi
- Department of Physics, Sétif1 University-Ferhat Abbas, Setif, Algeria
- Laboratory of Dosing, Analysis, and Characterization with High Resolution, Sétif1 University-Ferhat Abbas, Setif, Algeria
| | - Eren Şahiner
- Earth Sciences Application and Research Centre of Ankara University, Ankara, Turkey
| | - Chahra-Zed Benkhelifa
- Department of Physics, Sétif1 University-Ferhat Abbas, Setif, Algeria
- Laboratory of Dosing, Analysis, and Characterization with High Resolution, Sétif1 University-Ferhat Abbas, Setif, Algeria
| | - Aymen Garoui
- Department of Physics, Sétif1 University-Ferhat Abbas, Setif, Algeria
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2
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Alkorta I, Elguero J, Oliva-Enrich JM, Yáñez M, Mó O, Montero-Campillo MM. The Importance of Strain (Preorganization) in Beryllium Bonds. Molecules 2020; 25:molecules25245876. [PMID: 33322617 PMCID: PMC7763456 DOI: 10.3390/molecules25245876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 11/17/2022] Open
Abstract
In order to explore the angular strain role on the ability of Be to form strong beryllium bonds, a theoretical study of the complexes of four beryllium derivatives of orthocloso-carboranes with eight molecules (CO, N2, NCH, CNH, OH2, SH2, NH3, and PH3) acting as Lewis bases has been carried out at the G4 computational level. The results for these complexes, which contain besides Be other electron-deficient elements, such as B, have been compared with the analogous ones formed by three beryllium salts (BeCl2, CO3Be and SO4Be) with the same set of Lewis bases. The results show the presence of large and positive values of the electrostatic potential associated to the beryllium atoms in the isolated four beryllium derivatives of ortho-carboranes, evidencing an intrinsically strong acidic nature. In addition, the LUMO orbital in these systems is also associated to the beryllium atom. These features led to short intermolecular distances and large dissociation energies in the complexes of the beryllium derivatives of ortho-carboranes with the Lewis bases. Notably, as a consequence of the special framework provided by the ortho-carboranes, some of these dissociation energies are larger than the corresponding beryllium bonds in the already strongly bound SO4Be complexes, in particular for N2 and CO bases. The localized molecular orbital energy decomposition analysis (LMOEDA) shows that among the attractive terms associated with the dissociation energy, the electrostatic term is the most important one, except for the complexes with the two previously mentioned weakest bases (N2 and CO), where the polarization term dominates. Hence, these results contribute to further confirm the importance of bending on the beryllium environment leading to strong interactions through the formation of beryllium bonds.
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Affiliation(s)
- Ibon Alkorta
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, E-28006 Madrid, Spain;
- Correspondence: (I.A.); (J.M.O.-E.); (M.Y.)
| | - José Elguero
- Instituto de Química Médica (CSIC), Juan de la Cierva, 3, E-28006 Madrid, Spain;
| | - Josep M. Oliva-Enrich
- Instituto de Química-Física “Rocasolano” (CSIC), Serrano, 119, E-28006 Madrid, Spain
- Correspondence: (I.A.); (J.M.O.-E.); (M.Y.)
| | - Manuel Yáñez
- Departamento de Química, Facultad de Ciencias, Módulo 13, and Institute of Advanced Chemical Sciences (IadChem), Campus de Excelencia UAM-CSIC, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain; (O.M.); (M.M.M.-C.)
- Correspondence: (I.A.); (J.M.O.-E.); (M.Y.)
| | - Otilia Mó
- Departamento de Química, Facultad de Ciencias, Módulo 13, and Institute of Advanced Chemical Sciences (IadChem), Campus de Excelencia UAM-CSIC, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain; (O.M.); (M.M.M.-C.)
| | - M. Merced Montero-Campillo
- Departamento de Química, Facultad de Ciencias, Módulo 13, and Institute of Advanced Chemical Sciences (IadChem), Campus de Excelencia UAM-CSIC, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid, Spain; (O.M.); (M.M.M.-C.)
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3
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Sarigul N, Surucu M, Aydogan B. ENERGY RESPONSE FACTOR of BeO DOSEMETER CHIPS: A MONTE CARLO SIMULATION AND GENERAL CAVITY THEORY STUDY. Radiat Prot Dosimetry 2019; 185:303-309. [PMID: 30806472 DOI: 10.1093/rpd/ncz010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 01/01/2019] [Accepted: 01/18/2019] [Indexed: 06/09/2023]
Abstract
The objective of this study is to determine the energy response factors for BeO optically simulated dosemeter (OSLD) using general cavity theory and Monte Carlo (MC) simulations. A virtual phantom is constructed in EGSnrc MC program and energy response of BeO OSLDs were simulated at 5 cm depth for x-ray beams ranging from 1.25 to 25 MV and at 2 cm for beams with <250 kV including ISO 4037 narrow beam energies in a virtual water phantom. The energy response factor for a given radiation quality relative to 60Co was determined for BeO and compared to the Al2O3:C and LiF:Mg,Ti dosemeters. Burlin cavity theory calculations were done using mean photon energy (MPE) of the beam spectra, while EGSnrc software package was used to carry out MC simulation of full spectra. The cavity theory and MC methods agreed well within the 0.7%. Energy response of x-ray beams at MV range showed a maximum of 1.5% under-response. At energies higher than 150 kV (105 keV MPE) showed no significant difference while a significant under-response were observed at 100 kV (53 keV MPE) and 50 kV (29 keV MPE), ~8 and ~12%, respectively. BeO, Al2O3:C and LiF:Mg,Ti dosemeters exhibited very similar energy response at higher energies mainly in the MeV range. At 50 kV (29 keV MPE), however, BeO dosemeter under responded by a factor of 0.878, while Al2O3:C and LiF:Mg,Ti dosemeters over responded by a factor of 3.2 and 1.44, respectively. Furthermore, at low energies, BeO energy response showed dependence on photon spectra. For instance, at 100 kV, the difference was ~8, ~6 and 2% for 53, 60 and 83 keV MPE (ISO 4037N-100), respectively. Furthermore, calibration with 137Cs instead of 60Co resulted up to 1.8% differences in energy response. Both energy spectrum and calibration methods make considerable differences in energy response of OSLDs. This study concludes that BeO chips are nearly energy independent at energies higher than 100 keV MPE, while Al2O3:C dosemeters show an extremely enhanced energy-response ranging between 1.44 and 3.2 at energies between 170 and 29 keV MPE mainly due to dominance of photoelectric effect.
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Affiliation(s)
- Neslihan Sarigul
- Institute of Nuclear Science, Hacettepe University, Ankara, Turkey
| | - Murat Surucu
- Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL, USA
| | - Bulent Aydogan
- Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, IL, USA
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4
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Taal A, van der Kooij A, Okx WJC. A SHORTCUT FORMULA FOR THE 230-MeV PROTON-INDUCED NEUTRON DOSE EQUIVALENT IN CONCRETE AFTER A METAL SHIELD, DERIVED FROM MONTE CARLO SIMULATIONS WITH MCNPX. Radiat Prot Dosimetry 2016; 171:326-336. [PMID: 26374914 DOI: 10.1093/rpd/ncv403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 08/19/2015] [Accepted: 08/21/2015] [Indexed: 06/05/2023]
Abstract
Monte Carlo simulations were performed with MCNPX to determine the neutron dose equivalent in thick concrete after a metal shield, a double-layered shielding configuration. In the simulations, a 230-MeV proton beam impinging on a copper target was used to produce the neutrons. For forward angles up to 30° with respect to the proton beam, it is found that the neutron dose equivalent in thick concrete after a metal layer can be expressed in a single formula. This single formula being the neutron dose equivalent formula for a single thick concrete shield enhanced with an additional exponential term. The exponent of this additional exponential term is related to the relative macroscopic neutron removal cross section of the metal with respect to the concrete. The single formula found fits MCNPX data for the neutron dose equivalent in thick concrete after layers of metal ranging from beryllium to lead. First attempts were made to make this shortcut formula applicable to alloys and compounds of metals.
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Affiliation(s)
- A Taal
- Reactor Institute Delft, Mekelweg 15, Delft, The Netherlands
| | - A van der Kooij
- Reactor Institute Delft, Mekelweg 15, Delft, The Netherlands
| | - W J C Okx
- Reactor Institute Delft, Mekelweg 15, Delft, The Netherlands
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Haninger T, Hödlmoser H, Figel M, König-Meier D, Henniger J, Sommer M, Jahn A, Ledtermann G, Eßer R. PROPERTIES OF THE BEOSL DOSIMETRY SYSTEM IN THE FRAMEWORK OF A LARGE-SCALE PERSONAL MONITORING SERVICE. Radiat Prot Dosimetry 2016; 170:269-273. [PMID: 26424135 DOI: 10.1093/rpd/ncv425] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The Individual Monitoring Service of the Helmholtz Zentrum München is currently using the BeOSL dosimetry system for monitoring ∼15 000 persons per month. This dosimetry system has a modular structure and represents a complete new concept on handling dosemeters in a large-scale dosimetry service. It is based on optically stimulated luminescence dosemeters made of beryllium oxide. The dosimetric and operational properties of the system are shown and discussed.
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Affiliation(s)
- T Haninger
- Helmholtz Zentrum München, German Research Center for Environmental Health, Individual Monitoring Service, Otto-Hahn-Ring 6, D-81739 München, Germany
| | | | | | | | - J Henniger
- Technische Universität Dresden, Institut für Kern- und Teilchenphysik, Arbeitsgruppe Strahlungsphysik (ASP), D-01062 Dresden, Germany
| | - M Sommer
- Technische Universität Dresden, Institut für Kern- und Teilchenphysik, Arbeitsgruppe Strahlungsphysik (ASP), D-01062 Dresden, Germany
| | - A Jahn
- Technische Universität Dresden, Institut für Kern- und Teilchenphysik, Arbeitsgruppe Strahlungsphysik (ASP), D-01062 Dresden, Germany
| | - G Ledtermann
- Technische Universität Dresden, Institut für Kern- und Teilchenphysik, Arbeitsgruppe Strahlungsphysik (ASP), D-01062 Dresden, Germany
| | - R Eßer
- Dosimetrics GmbH, Otto-Hahn-Ring 6, D-81739 München, Germany
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Zhuang W, Chen Q, Gao X, Zhou F, Wang M, Liu Y. Characterization of surface sediments from the Beijing-Hangzhou Grand Canal (Zaozhuang section), China: assessment of beryllium enrichment, biological effect, and mobility. Environ Sci Pollut Res Int 2016; 23:13560-8. [PMID: 27167375 DOI: 10.1007/s11356-016-6837-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 05/04/2016] [Indexed: 05/14/2023]
Abstract
The South-to-North Water Diversion Project is one of the world's largest water diversion projects, benefiting seven million people in China. The Zaozhuang section of the Beijing-Hangzhou Grand Canal is an important part of this project. This paper investigated the enrichment, biological effect, and mobility of beryllium (Be) in surface sediments of the Zaozhuang section. Results showed that high values were found in Tai'erzhuang District, Zaozhuang city, and the areas near the inlet of the Nansihu Lake, which might have been influenced by local human activities including metallurgy, burning of fossil fuels, and transportation. Four geochemical fractions of Be were obtained: acid-soluble fraction, reducible fraction, oxidizable fraction, and residual fraction. The non-residual fractions (the sum of the first three) accounted for 72.5 ∼ 96.1 % of the total amount of Be. Acid-soluble fraction might be mainly influenced by human activities, with the strongest mobility and bio-availability, accounting for 4.1 ∼ 44.7 % of the total amount, with an average of 20.2 %. Enrichment factor (EF) showed minor to moderate enrichment in some regions; adverse effect index (AEI) also showed that there were high levels of Be in some regions, which might have negative impacts on organisms. Generally, mobility, EF, and AEI of elements are carried out separately. But the results of this study indicated that a comprehensive assessment on the enrichment, mobility, and biological effects of Be caused by human activities is necessary in understanding the environmental risks of Be.
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Affiliation(s)
- Wen Zhuang
- College of City and Architecture Engineering, Zaozhuang University, Zaozhuang, Shandong, 277160, China.
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, 264003, China.
| | - Qing Chen
- College of Life Sciences, Zaozhuang University, Zaozhuang, Shandong, 277160, China
| | - Xuelu Gao
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, 264003, China
| | - Fengxia Zhou
- Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, 264003, China
| | - Mantang Wang
- College of City and Architecture Engineering, Zaozhuang University, Zaozhuang, Shandong, 277160, China
| | - Yongxia Liu
- College of City and Architecture Engineering, Zaozhuang University, Zaozhuang, Shandong, 277160, China
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7
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Rousset D, Durand T. Beryllium solubility in occupational airborne particles: Sequential extraction procedure and workplace application. J Occup Environ Hyg 2016; 13:71-83. [PMID: 26327570 DOI: 10.1080/15459624.2015.1078467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Modification of an existing sequential extraction procedure for inorganic beryllium species in the particulate matter of emissions and in working areas is described. The speciation protocol was adapted to carry out beryllium extraction in closed-face cassette sampler to take wall deposits into account. This four-step sequential extraction procedure aims to separate beryllium salts, metal, and oxides from airborne particles for individual quantification. Characterization of the beryllium species according to their solubility in air samples may provide information relative to toxicity, which is potentially related to the different beryllium chemical forms. Beryllium salts (BeF(2), BeSO(4)), metallic beryllium (Bemet), and beryllium oxide (BeO) were first individually tested, and then tested in mixtures. Cassettes were spiked with these species and recovery rates were calculated. Quantitative analyses with matched matrix were performed using inductively coupled plasma mass spectrometry (ICP-MS). Method Detection Limits (MDLs) were calculated for the four matrices used in the different extraction steps. In all cases, the MDL was below 4.2 ng/sample. This method is appropriate for assessing occupational exposure to beryllium as the lowest recommended threshold limit values are 0.01 µg.m(-3) in France([) (1) (]) and 0.05 µg.m(-3) in the USA.([ 2 ]) The protocol was then tested on samples from French factories where occupational beryllium exposure was suspected. Beryllium solubility was variable between factories and among the same workplace between different tasks.
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Affiliation(s)
- Davy Rousset
- a Institut National de Recherche et de Sécurité (INRS) , Département Métrologie des Polluants , Vandoeuvre , France
| | - Thibaut Durand
- a Institut National de Recherche et de Sécurité (INRS) , Département Métrologie des Polluants , Vandoeuvre , France
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Chinopoulos C, Kiss G, Kawamata H, Starkov AA. Measurement of ADP-ATP exchange in relation to mitochondrial transmembrane potential and oxygen consumption. Methods Enzymol 2015; 542:333-48. [PMID: 24862274 DOI: 10.1016/b978-0-12-416618-9.00017-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have previously described a fluorometric method to measure ADP-ATP exchange rates in mitochondria of permeabilized cells, in which several enzymes that consume substantial amounts of ATP and other competing reactions interconverting adenine nucleotides are present. This method relies on recording changes in free extramitochondrial Mg(2+) with the Mg(2+)-sensitive fluorescent indicator Magnesium Green (MgGr)™, exploiting the differential affinity of ADP and ATP for Mg(2+). In particular, cells are permeabilized with digitonin in the presence of BeF3(-) and Na3VO4, inhibiting all ATP- and ADP-utilizing reactions but mitochondrial exchange of ATP with ADP catalyzed by the adenine nucleotide translocase. The rate of ATP appearing in the medium upon the addition of ADP to energized mitochondria is then calculated from the rate of change in free extramitochondrial Mg(2+) using standard binding equations. Here, we describe a variant of this method involving an improved calibration step. This step minimizes errors that may be introduced during the conversion of the MgGr™ signal into free extramitochondrial [Mg(2+)] and ATP. Furthermore, we describe an approach for combining this methodology with the measurement of mitochondrial membrane potential and oxygen consumption in the same sample. The method described herein is useful for the study of malignant cells, which are known to thrive in hypoxic environments and to harbor mitochondria with profound functional alterations.
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Affiliation(s)
| | - Gergely Kiss
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Hibiki Kawamata
- Brain and Mind Research Institute, Weill Medical College of Cornell University, New York, USA
| | - Anatoly A Starkov
- Brain and Mind Research Institute, Weill Medical College of Cornell University, New York, USA
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Gordo E, Dueñas C, Fernández MC, Liger E, Cañete S. Behavior of ambient concentrations of natural radionuclides (7)Be, (210)Pb, (40)K in the Mediterranean coastal city of Málaga (Spain). Environ Sci Pollut Res Int 2015; 22:7653-7664. [PMID: 25561266 DOI: 10.1007/s11356-014-4039-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/22/2014] [Indexed: 06/04/2023]
Abstract
During a 4-year period (January 2009-December 2012), the (7)Be, (210)Pb, and (40)K activity concentrations in airborne particulate matter were weekly determined at the Málaga (Spain) located in the southern Iberian Peninsula. Totally 209 polypropylene filters were analyzed in the mentioned period. In 100% of the filters, (7)Be and (40)K activity concentrations were detected while (210)Pb activity concentration was detected in 96% of the filters. The results from individual measurements of (7)Be, (210)Pb, and (40)K concentrations were analyzed to derive the statistical estimates characterizing the distributions. Principal components analysis (PCA) was applied to the datasets and the results of the study reveal that aerosol behavior is represented by two principal components which explain 73.2% of total variance. Components PC1 and PC2 respectively explain 46.0 and 27.2% of total variance. PC1 was related positively to dust content, (7)Be and (40)K concentrations and negatively to sunspot numbers. In contrast, PC2 was related positively to temperature and (210)Pb activity and negatively to precipitation and relative humidity. The (7)Be levels showed a significant correlation with sunspot numbers due to the cosmogenic origin. (40)K activities showed a good correlation with dust deposition in filters mainly because it was transported to the air as resuspended particle from the soil. An inverse relationship was observed between the (210)Pb concentrations and monthly rainfall, indicating washout of atmospheric aerosols carrying these radionuclides and a pronounced positive correlation with the average monthly temperature of air.
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Affiliation(s)
- E Gordo
- Department of Applied Physics I, Faculty of Sciences, University of Málaga, 29071, Málaga, Spain,
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Frost RL, López A, Theiss FL, Romano AW, Scholz R. An SEM, EDS and vibrational spectroscopic study of the silicate mineral meliphanite (Ca,Na)2Be[(Si,Al)2O6(F,OH)]. Spectrochim Acta A Mol Biomol Spectrosc 2015; 136 Pt B:216-220. [PMID: 25440583 DOI: 10.1016/j.saa.2014.09.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 08/24/2014] [Accepted: 09/11/2014] [Indexed: 06/04/2023]
Abstract
The mineral meliphanite (Ca,Na)2Be[(Si,Al)2O6(F,OH)] is a crystalline sodium calcium beryllium silicate which has the potential to be used as piezoelectric material and for other ferroelectric applications. The mineral has been characterized by a combination of scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and vibrational spectroscopy. EDS analysis shows a material with high concentrations of Si and Ca and low amounts of Na, Al and F. Beryllium was not detected. Raman bands at 1016 and 1050 cm(-1) are assigned to the SiO and AlOH stretching vibrations of three dimensional siloxane units. The infrared spectrum of meliphanite is very broad in comparison with the Raman spectrum. Raman bands at 472 and 510 cm(-1) are assigned to OSiO bending modes. Raman spectroscopy identifies bands in the OH stretching region. Raman spectroscopy with complimentary infrared spectroscopy enables the characterization of the silicate mineral meliphanite.
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Affiliation(s)
- Ray L Frost
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia.
| | - Andrés López
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia
| | - Frederick L Theiss
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001, Australia
| | - Antônio Wilson Romano
- Geology Department, School of Mines, Federal University of Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, MG 35400-00, Brazil
| | - Ricardo Scholz
- Geology Department, School of Mines, Federal University of Ouro Preto, Campus Morro do Cruzeiro, Ouro Preto, MG 35400-00, Brazil
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Abstract
Investigations on track density and track size distributions of different PADC (poly allyl diglycol carbonate) materials have been performed. The PADC used for the tests has been produced by Thermo Electron (USA), Track Analysis System Limited (UK), Chiyoda Technol Corporation (Japan) and Intercast srl (Italy). For each PADC material 120 detectors were randomly selected out of 2 sheets: 60 detectors from one sheet have been irradiated with a personal dose equivalent of 3 mSv in the field of a (241)Am-Be source at the calibration laboratory of PSI, whilst the other 60 detectors from the other sheet have been used as background samples. All detectors have been processed according to an identical etching procedure and have been analysed with TASLImage scanning system. For each set of detectors the value of the average background signal, the average neutron sensitivity and the detection limit with respect to a personal dose equivalent measured with a dosemeter based on PADC have been determined. The results of the investigations allowed a comparison of the neutron sensitivity and background signal behaviours of PADC materials from different manufacturers and the assessment of the variation of neutron sensitivity and background signal over a single sheet.
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Affiliation(s)
- S Mayer
- Division for Radiation Safety and Security, Paul Scherrer Institute (PSI), Villigen PSI, Switzerland
| | - M Boschung
- Division for Radiation Safety and Security, Paul Scherrer Institute (PSI), Villigen PSI, Switzerland
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Atanackovic J, Matysiak W, Witharana S, Dubeau J, Waker AJ. Measurements of neutron energy spectra from 7Li(p,n)7Be reaction with Bonner sphere spectrometer, Nested Neutron Spectrometer and ROSPEC. Radiat Prot Dosimetry 2014; 161:221-224. [PMID: 24298169 DOI: 10.1093/rpd/nct314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Neutron spectrometry measurements were carried out at the McMaster Accelerator Laboratory (MAL), which is equipped with a 3-MV Van de Graaff-type accelerator. Protons were accelerated onto a thick natural lithium target inducing the (7)Li(p,n)(7)Be threshold reaction. Depending on the proton energy, slightly different poly-energetic neutron fields were produced. Neutron spectra were measured at two incident proton energies: 2.15 and 2.24 MeV, which produced poly-energetic neutrons with maximum kinetic energies of 401 and 511 keV, respectively. Measurements were performed at a distance of 1.5 m from the target in the forward direction with three different instruments: Bonner sphere spectrometer, Nested Neutron Spectrometer and ROtational proton recoil SPECtrometer.
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Affiliation(s)
- J Atanackovic
- Chalk River Laboratories, Atomic Energy of Canada Limited, ON, Canada K0J 1J0
| | - W Matysiak
- University of Florida Proton Therapy Institute, Jacksonville FL 32206, USA
| | | | - J Dubeau
- DETEC, Gatineau, QC, Canada J8 T 4J1
| | - A J Waker
- University of Ontario Institute of Technology, Oshawa, ON, Canada L1H 7K4
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Abstract
Thermoluminescence (TL) and optically stimulated luminescence (OSL) are the well-known phenomena used for passive methods of dose measurements. TL and OSL detectors are frequently used in the dosimetry of cosmic radiation in space and of particle radiotherapy beams. However, the relative TL/OSL efficiency, which is defined as a ratio of the emitted light intensity per unit dose for a given radiation type, to the same quantity for the reference gamma radiation is not constant and depends on radiation type and energy. In the present work several types of TL and OSL dosimetric materials, including lithium fluoride (LiF), aluminium oxide, beryllium oxide and lithium aluminate, were tested with protons. The measurements were realised exploiting the 60-MeV proton beam of the AIC-144 cyclotron in the Proton Eye Radiotherapy Facility at Institute of Nuclear Physics (IFJ PAN). The influence of proton energy on the relative efficiency and other TL/OSL characteristics of the studied detector types was presented.
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Affiliation(s)
- M Sądel
- Institute of Nuclear Physics, Radzikowskiego 152, Krakow 31-342, Poland
| | - P Bilski
- Institute of Nuclear Physics, Radzikowskiego 152, Krakow 31-342, Poland
| | - J Swakoń
- Institute of Nuclear Physics, Radzikowskiego 152, Krakow 31-342, Poland
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14
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Pola A, Bortot D, Introini MV, Bedogni R, Gentile A, Esposito A, Gómez-Ros JM, Passoth E, Prokofiev A. Compact thermal neutron sensors for moderator-based neutron spectrometers. Radiat Prot Dosimetry 2014; 161:229-232. [PMID: 24277874 DOI: 10.1093/rpd/nct298] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In the framework of the NESCOFI@BTF project of the Italian Institute of Nuclear Physics, different types of active thermal neutron sensors were studied by coupling semiconductor devices with a suitable radiator. The objective was to develop a detector of small dimensions with a proper sensitivity to use at different positions in a novel moderating assembly for neutron spectrometry. This work discusses the experimental activity carried out in the framework of the ERINDA program (PAC 3/9 2012) to characterise the performance of a thermal neutron pulse detector based on (6)Li.
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Affiliation(s)
- A Pola
- Politecnico di Milano, Via Ponzio 34/3, 20133 Milano, Italy INFN-MI, via Celoria 16, 20133 Milano, Italy
| | - D Bortot
- Politecnico di Milano, Via Ponzio 34/3, 20133 Milano, Italy INFN-LNF, Via E. Fermi n. 40, 00044 Frascati (Roma), Italy
| | - M V Introini
- Politecnico di Milano, Via Ponzio 34/3, 20133 Milano, Italy INFN-MI, via Celoria 16, 20133 Milano, Italy
| | - R Bedogni
- INFN-LNF, Via E. Fermi n. 40, 00044 Frascati (Roma), Italy
| | - A Gentile
- INFN-LNF, Via E. Fermi n. 40, 00044 Frascati (Roma), Italy
| | - A Esposito
- INFN-LNF, Via E. Fermi n. 40, 00044 Frascati (Roma), Italy
| | - J M Gómez-Ros
- INFN-LNF, Via E. Fermi n. 40, 00044 Frascati (Roma), Italy CIEMAT, Avda. Complutense 40, 28040 Madrid, Spain
| | - E Passoth
- TSL - The Svedberg Laboratory, Uppsala University, Uppsala, Sweden
| | - A Prokofiev
- TSL - The Svedberg Laboratory, Uppsala University, Uppsala, Sweden
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15
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Biesdorf J, Oberholzer P, Bernauer F, Kaestner A, Vontobel P, Lehmann EH, Schmidt TJ, Boillat P. Dual spectrum neutron radiography: identification of phase transitions between frozen and liquid water. Phys Rev Lett 2014; 112:248301. [PMID: 24996112 DOI: 10.1103/physrevlett.112.248301] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Indexed: 06/03/2023]
Abstract
In this Letter, a new approach to distinguish liquid water and ice based on dual spectrum neutron radiography is presented. The distinction is based on arising differences between the cross section of water and ice in the cold energy range. As a significant portion of the energy spectrum of the ICON beam line at Paul Scherrer Institut is in the thermal energy range, no differences can be observed with the entire beam. Introducing a polycrystalline neutron filter (beryllium) inside the beam, neutrons above its cutoff energy are filtered out and the cold energy region is emphasized. Finally, a contrast of about 1.6% is obtained with our imaging setup between liquid water and ice. Based on this measurement concept, the temporal evolution of the aggregate state of water can be investigated without any prior knowledge of its thickness. Using this technique, we could unambiguously prove the production of supercooled water inside fuel cells with a direct measurement method.
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Affiliation(s)
- J Biesdorf
- Electrochemistry Laboratory (ECL), Paul Scherrer Institut (PSI), 5232 Villigen PSI, Switzerland
| | - P Oberholzer
- Electrochemistry Laboratory (ECL), Paul Scherrer Institut (PSI), 5232 Villigen PSI, Switzerland
| | - F Bernauer
- Electrochemistry Laboratory (ECL), Paul Scherrer Institut (PSI), 5232 Villigen PSI, Switzerland
| | - A Kaestner
- Neutron Imaging and Activation Group (NIAG), Paul Scherrer Institut (PSI), 5232 Villigen PSI, Switzerland
| | - P Vontobel
- Neutron Imaging and Activation Group (NIAG), Paul Scherrer Institut (PSI), 5232 Villigen PSI, Switzerland
| | - E H Lehmann
- Neutron Imaging and Activation Group (NIAG), Paul Scherrer Institut (PSI), 5232 Villigen PSI, Switzerland
| | - T J Schmidt
- Neutron Imaging and Activation Group (NIAG), Paul Scherrer Institut (PSI), 5232 Villigen PSI, Switzerland
| | - P Boillat
- Electrochemistry Laboratory (ECL), Paul Scherrer Institut (PSI), 5232 Villigen PSI, Switzerland and Neutron Imaging and Activation Group (NIAG), Paul Scherrer Institut (PSI), 5232 Villigen PSI, Switzerland
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16
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Maki H, Tsujito M, Nariai H, Mizuhata M. ⁹Be and ³¹P NMR analyses on the influence of imino groups on Be²⁺ complex stabilities of a series of cyclo-μ-imido triphosphate anions. Magn Reson Chem 2014; 52:69-81. [PMID: 25289393 DOI: 10.1002/mrc.4037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The complexation behaviors of Be²⁺ with cyclo-μ-imido triphosphate anions, cP₃O₉-n(NH)n(3-)n= 1, 2),have been investigated by both ⁹Be and ³¹P NMR techniques at -2.3 °C in order to clarify the coordination structures of the complexes. The spectra showed that cP₃O₉n(NH)n (n = 1, 2) ligands form ML, ML₂, and M₂L complexes with Be²⁺ ions, and the formation of complexes coordinating with nitrogen atoms of the cyclic framework in the ligand molecule has been excluded. These complexation trends are very similar to those of Be²⁺-cP₃O₆(NH)⁻³₃system, which has been reported by us. The peak deconvolution of ⁹BeNMR spectra made these beryllium complexes amenable to stability constant determinations. The stability constants of the complexes increase with an increase in the protonation constants of the ligands as the number of imino groups, which constitute the ligand molecules, is ascended. This increase is primarily attributable to the lower electronegativity of nitrogen atoms than oxygen atoms, which are directly bonded to central phosphorus atoms; moreover, tautomerism equilibrium in the entire of the imidopolyphosphate molecule is also responsible to the higher basicity. ³¹P NMR spectra measured concurrently have verified the formation of the complexes estimated by the ⁹Be NMR measurement. Intrinsic ³¹P NMR chemical shift values of the phosphorus atoms belonging to ligand molecules complexed with Be²⁺ cations have been determined. Not only the protonation constants but also the stability constants of all Be²⁺ complexes increase approximately linearly with an increase in the number of imino groups.
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Affiliation(s)
- Hideshi Maki
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1–1 Rokkodai-cho, Nada-ku, Kobe 657–8501, Japan.
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17
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Stark M, Lerman Y, Kapel A, Pardo A, Schwarz Y, Newman L, Maier L, Fireman E. Biological exposure metrics of beryllium-exposed dental technicians. Arch Environ Occup Health 2014; 69:89-99. [PMID: 24205960 PMCID: PMC4347856 DOI: 10.1080/19338244.2012.744736] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Beryllium is commonly used in the dental industry. This study investigates the association between particle size and shape in induced sputum (IS) with beryllium exposure and oxidative stress in 83 dental technicians. Particle size and shape were defined by laser and video, whereas beryllium exposure data came from self-reports and beryllium lymphocyte proliferation test (BeLPT) results. Heme oxygenase-1 (HO1) gene expression in IS was evaluated by quantitative polymerase chain reaction. A high content of particles (92%) in IS >5 μ in size is correlated to a positive BeLPT risk (odds ratio [OR] = 3.4, 95% confidence interval [CI]: 0.9-13). Use of masks, hoods, and type of exposure yielded differences in the transparency of IS particles (gray level) and modulate HO1 levels. These results indicate that parameters of size and shape of particles in IS are sensitive to workplace hygiene, affect the level of oxidative stress, and may be potential markers for monitoring hazardous dust exposures.
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Affiliation(s)
- Moshe Stark
- a Institute of Pulmonary Diseases, National Laboratory Service for ILD, Tel Aviv Sourasky Medical Center , Tel Aviv , Israel
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18
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Fireman E, Lerman Y, Stark M, Pardo A, Schwarz Y, Van Dyke MV, Elliot J, Barkes B, Newman L, Maier L. A novel alternative to environmental monitoring to detect workers at risk for beryllium exposure-related health effects. J Occup Environ Hyg 2014; 11:809-818. [PMID: 24856577 PMCID: PMC4347844 DOI: 10.1080/15459624.2014.922689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The purpose of this study was to describe a methodology for surveillance and monitoring of beryllium exposure using biological monitoring to complement environmental monitoring. Eighty-three Israeli dental technicians (mean age 41.6 ± 1.36 years) and 80 American nuclear machining workers (54.9 ± 1.21 years) were enrolled. Biological monitoring was carried out by analyzing particle size (laser technique) and shape (image analysis) in 131/163 (80.3%) induced sputum samples (Dipa Analyser, Donner Tech, Or Aquiva, Israel). Environmental monitoring was carried out only in the United States (Sioutas impactor, SKC, Inc., Eighty Four, Pa.). Pulmonary function testing performance and induced sputum retrieval were done by conventional methods. Sixty-three Israeli workers and 37 American workers were followed up for at least 2 years. Biological monitoring by induced sputum indicated that a >92% accumulation of <5 μm particles correlated significantly to a positive beryllium lymphocyte proliferation test result (OR 3.8, 95% CI 1.2-11.4, p = 0.015) among all participants. Environmental monitoring showed that beryllium particles were <1 μm, and this small fraction (0.1-1 μ) was significantly more highly accumulated in nuclear machining workers compared to dental technicians. The small fractions positively correlated with induced sputum macrophages (r = 0.21 p = 0.01) and negatively correlated with diffusion lung carbon monoxide single breath (DLCO-SB r = 0.180 p = 0.04) in all subjects. Years of exposure were positively correlated to the number of accumulated particles 2-3 μ in diameter (r = 0.2, p = 0.02) and negatively correlated to forced expiratory volume in one second/forced vital capacity findings (r = -0.18, p = 0.02). DLCO was decreased in both groups after two years of monitoring. Biological monitoring is more informative than environmental monitoring in the surveillance and monitoring of workers in beryllium industries. Induced sputum is a feasible and promising biomonitoring method that should be included in the surveillance of exposed workers.
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Affiliation(s)
- Elizabeth Fireman
- Institute of Pulmonary and Allergic Diseases, National Laboratory Service for ILD, Tel-Aviv Medical Center, Tel Aviv University, Tel Aviv, Israel
- Department of Environmental and Occupational Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yehuda Lerman
- Department of Environmental and Occupational Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Occupational Health Department, Clalit Medical Services, Tel Aviv, Israel
| | - Moshe Stark
- Institute of Pulmonary and Allergic Diseases, National Laboratory Service for ILD, Tel-Aviv Medical Center, Tel Aviv University, Tel Aviv, Israel
- Department of Environmental and Occupational Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Asher Pardo
- Department of Environmental and Occupational Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Yehuda Schwarz
- Institute of Pulmonary and Allergic Diseases, National Laboratory Service for ILD, Tel-Aviv Medical Center, Tel Aviv University, Tel Aviv, Israel
| | - Michael V. Van Dyke
- Colorado School of Public Health, University of Colorado, Denver, Colorado Department of Medicine, School of Medicine, University of Colorado, Denver, Colorado
| | - Jill Elliot
- Division of Environmental and Occupational Health Sciences, National Jewish Health, Denver, Colorado
| | - Briana Barkes
- Division of Environmental and Occupational Health Sciences, National Jewish Health, Denver, Colorado
| | - Lee Newman
- Colorado School of Public Health, University of Colorado, Denver, Colorado Department of Medicine, School of Medicine, University of Colorado, Denver, Colorado
| | - Lisa Maier
- Division of Environmental and Occupational Health Sciences, National Jewish Health, Denver, Colorado
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19
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Dytrych T, Launey KD, Draayer JP, Maris P, Vary JP, Saule E, Catalyurek U, Sosonkina M, Langr D, Caprio MA. Collective modes in light nuclei from first principles. Phys Rev Lett 2013; 111:252501. [PMID: 24483740 DOI: 10.1103/physrevlett.111.252501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Indexed: 06/03/2023]
Abstract
Results for ab initio no-core shell model calculations in a symmetry-adapted SU(3)-based coupling scheme demonstrate that collective modes in light nuclei emerge from first principles. The low-lying states of 6Li, 8Be, and 6He are shown to exhibit orderly patterns that favor spatial configurations with strong quadrupole deformation and complementary low intrinsic spin values, a picture that is consistent with the nuclear symplectic model. The results also suggest a pragmatic path forward to accommodate deformation-driven collective features in ab initio analyses when they dominate the nuclear landscape.
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Affiliation(s)
- T Dytrych
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - K D Launey
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - J P Draayer
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - P Maris
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - J P Vary
- Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| | - E Saule
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio 43210, USA
| | - U Catalyurek
- Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio 43210, USA and Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210, USA
| | - M Sosonkina
- Department of Modeling, Simulation and Visualization Engineering, Old Dominion University, Norfolk, Virginia 23529, USA
| | - D Langr
- Department of Computer Systems, Faculty of Information Technology, Czech Technical University in Prague, Prague 16000, Czech Republic
| | - M A Caprio
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
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20
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Kobayashi T, Miura K, Hayashizaki N, Aritomi M. Development of liquid-lithium film jet-flow for the target of (7)Li(p,n)(7)Be reactions for BNCT. Appl Radiat Isot 2013; 88:198-202. [PMID: 24412425 DOI: 10.1016/j.apradiso.2013.12.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 12/11/2013] [Accepted: 12/11/2013] [Indexed: 11/19/2022]
Abstract
A feasibility study on liquid lithium target in the form of a flowing film was performed to evaluate its potential use as a neutron generation target of (7)Li(p,n)(7)Be reaction in BNCT. The target is a windowless-type flowing film on a concave wall. Its configuration was adapted for a proton beam which is 30mm in diameter and with energy and current of up to 3MeV and 20mA, respectively. The flowing film of liquid lithium was 0.6mm in thickness, 50mm in width and 50mm in length. The shapes of the nozzle and concave back wall, which create a stable flowing film jet, were decided based on water experiments. A lithium hydrodynamic experiment was performed to observe the stability of liquid lithium flow behavior. The flowing film of liquid lithium was found to be feasible at temperatures below the liquid lithium boiling saturation of 342°C at the surface pressure of 1×10(-3)Pa. Using a proto-type liquid lithium-circulating loop for BNCT, the stability of the film flow was confirmed for velocities up to 30m/s at 220°C and 250°C in vacuum at a pressure lower than 10(-3) Pa. It is expected that for practical use, a flowing liquid lithium target of a windowless type can solve the problem of radiation damage and target cooling.
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Affiliation(s)
- Tooru Kobayashi
- Kyoto University Research Reactor Institute, Osaka 590-0494, Japan; Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Kuniaki Miura
- Sukegawa Electric Co., Ltd., Ibaraki 317-0051, Japan
| | - Noriyosu Hayashizaki
- Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Masanori Aritomi
- Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550, Japan
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21
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Rajan RP, Riesen H, Rebane A. Controlling pulse delay by light and low magnetic fields: slow light in emerald induced by transient spectral hole-burning. Opt Lett 2013; 38:4546-4549. [PMID: 24322070 DOI: 10.1364/ol.38.004546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Slow light based on transient spectral hole-burning is reported for emerald, Be(3)Al(2)Si(6)O(18):Cr(3+). Experiments were conducted in π polarization on the R(1)(± 3/2) line (E2 ← A(2)4) at 2.2 K in zero field and low magnetic fields B||c. The hole width was strongly dependent on B||c, and this allowed us to smoothly tune the pulse delay from 40 to 154 ns between zero field and B||c = 15.2 mT. The latter corresponds to a group velocity of 16 km/s. Slow light in conjunction with a linear filter theory can be used as a powerful and accurate technique in time-resolved spectroscopy, e.g., to determine spectral hole-widths as a function of time.
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22
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Pillalamarri I, Jagam P, Lykken GI. Internal dosimetry of 210Pb in the human cranium: preliminary results from instrumentation needs for in vivo counting in a low-background underground counting facility. Radiat Prot Dosimetry 2013; 157:6-10. [PMID: 23620563 DOI: 10.1093/rpd/nct109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Internal dosimetry of (210)Pb in the cranium deals with the determination of the amount of energy deposited in tissue by (210)Pb radiations within the cranium. (210)Pb in the human cranium was monitored by in vivo counting in a low background facility 640 m (2100 ft) underground with a germanium (Ge) gamma-ray detector having a beryllium window. The minimum detectable activity (MDA) was established with this system to be 0.2 Bq (5 pCi) in 25-h counting time with a 15-mm diameter and 7-mm thick Ge detector, having a beryllium window of thickness of 0.08 mm, in contact with the cranium just above the ear adjacent to the temple region. To establish an MDA of 0.004 Bq (0.1 pCi) with this system, the limitation arising from the ambient radon level at 10 Bq m(-3) was investigated.
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Affiliation(s)
- Ila Pillalamarri
- Carlsbad Environmental Monitoring and Research Center, 1400 University Dr, Carlsbad, NM 88220-3575, USA
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23
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Abstract
The detailed Monte Carlo simulation of a boron-lined proportional counter response to a neutron source has been presented. The MCNP4C and experimental data on different source-moderator geometries have been given for comparison. The influence of different irradiation geometries and boron-lining thicknesses on the detector response has been studied.
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Affiliation(s)
- A Shahri
- School of Physics, Damghan University, Damghan, Iran
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24
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Olovsson W, Weinhardt L, Fuchs O, Tanaka I, Puschnig P, Umbach E, Heske C, Draxl C. The Be K-edge in beryllium oxide and chalcogenides: soft x-ray absorption spectra from first-principles theory and experiment. J Phys Condens Matter 2013; 25:315501. [PMID: 23835492 DOI: 10.1088/0953-8984/25/31/315501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We have carried out a theoretical and experimental investigation of the beryllium K-edge soft x-ray absorption fine structure of beryllium compounds in the oxygen group, considering BeO, BeS, BeSe, and BeTe. Theoretical spectra are obtained ab initio, through many-body perturbation theory, by solving the Bethe-Salpeter equation (BSE), and by supercell calculations using the core-hole approximation. All calculations are performed with the full-potential linearized augmented plane-wave method. It is found that the two different theoretical approaches produce a similar fine structure, in good agreement with the experimental data. Using the BSE results, we interpret the spectra, distinguishing between bound core-excitons and higher energy excitations.
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Affiliation(s)
- W Olovsson
- Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping, Sweden.
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25
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Lim WX, Thornton AW, Hill AJ, Cox BJ, Hill JM, Hill MR. High performance hydrogen storage from Be-BTB metal-organic framework at room temperature. Langmuir 2013; 29:8524-8533. [PMID: 23805913 DOI: 10.1021/la401446s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The metal-organic framework beryllium benzene tribenzoate (Be-BTB) has recently been reported to have one of the highest gravimetric hydrogen uptakes at room temperature. Storage at room temperature is one of the key requirements for the practical viability of hydrogen-powered vehicles. Be-BTB has an exceptional 298 K storage capacity of 2.3 wt % hydrogen. This result is surprising given that the low adsorption enthalpy of 5.5 kJ mol(-1). In this work, a combination of atomistic simulation and continuum modeling reveals that the beryllium rings contribute strongly to the hydrogen interaction with the framework. These simulations are extended with a thermodynamic energy optimization (TEO) model to compare the performance of Be-BTB to a compressed H2 tank and benchmark materials MOF-5 and MOF-177 in a MOF-based fuel cell. Our investigation shows that none of the MOF-filled tanks satisfy the United States Department of Energy (DOE) storage targets within the required operating temperatures and pressures. However, the Be-BTB tank delivers the most energy per volume and mass compared to the other material-based storage tanks. The pore size and the framework mass are shown to be contributing factors responsible for the superior room temperature hydrogen adsorption of Be-BTB.
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Affiliation(s)
- Wei-Xian Lim
- Nanomechanics Group, School of Mathematical Sciences, The University of Adelaide, SA 5005, Australia
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26
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Lubk A, Rossell MD, Seidel J, Chu YH, Ramesh R, Hÿtch MJ, Snoeck E. Electromechanical coupling among edge dislocations, domain walls, and nanodomains in BiFeO3 revealed by unit-cell-wise strain and polarization maps. Nano Lett 2013; 13:1410-1415. [PMID: 23418908 DOI: 10.1021/nl304229k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The performance of ferroelectric devices, for example, the ferroelectric field effect transistor, is reduced by the presence of crystal defects such as edge dislocations. For example, it is well-known that edge dislocations play a crucial role in the formation of ferroelectric dead-layers at interfaces and hence finite size effects in ferroelectric thin films. The detailed lattice structure including the relevant electromechanical coupling mechanisms in close vicinity of the edge dislocations is, however, not well-understood, which hampers device optimization. Here, we investigate edge dislocations in ferroelectric BiFeO3 by means of spherical aberration-corrected scanning transmission electron microscopy, a dedicated model-based structure analysis, and phase field simulations. Unit-cell-wise resolved strain and polarization profiles around edge dislocation reveal a wealth of material states including polymorph nanodomains and multiple domain walls characteristically pinned to the dislocation. We locally determine the piezoelectric tensor and identify piezoelectric coupling as the driving force for the observed phenomena, explaining, for example, the orientation of the domain wall with respect to the edge dislocation. Furthermore, an atomic model for the dislocation core is derived.
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Affiliation(s)
- A Lubk
- Triebenberg Laboratory, Institute of Structure Physics, Technische Universität Dresden, 01062 Dresden, Germany.
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27
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Ghorbani P, Bayat E, Ghal-Eh N. A comparison study on three different radiation detectors used for liquid levelmetry. Radiat Prot Dosimetry 2013; 156:103-108. [PMID: 23520202 DOI: 10.1093/rpd/nct046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In this paper, three different radiation detectors (BF3 counter, NE213 and BGO scintillators) and an (241)Am-Be isotopic neutron-gamma source have been used for a typical liquid levelmetry. The study shows that the use of the Am-Be source together with an NE213 scintillator has the best performance.
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Affiliation(s)
- P Ghorbani
- School of Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
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28
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Samsonowicz M, Regulska E, Świsłocka R, Lewandowski W. Experimental and theoretical study of molecular structure of beryllium, magnesium, calcium, strontium and barium 4-nitrobenzoates. Spectrochim Acta A Mol Biomol Spectrosc 2013; 103:456-466. [PMID: 23261035 DOI: 10.1016/j.saa.2012.11.073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 11/19/2012] [Accepted: 11/23/2012] [Indexed: 06/01/2023]
Abstract
The influence of alkaline earth metal ions on the electronic system of 4-nitrobenzoic acid was studied in this paper. The vibrational (FT-IR) and NMR ((1)H and (13)C) spectra were recorded for 4-nitrobenzoic acid (4-nba) and its salts (4-nb). The assignment of vibrational spectra was done. Some shifts of band wavenumbers in alkaline earth metal 4-nitrobenzoates spectra were observed in the series from magnesium to barium salts. Good correlations between wavenumbers of the vibrational bands in the IR spectra of studied salts and ionic potential, electronegativity, inverse of atomic mass, ionic radius and ionization energy of studied metals were found. The regular changes in the chemical shifts of protons ((1)H NMR) and carbons ((13)C NMR) in the series of studied salts were also observed. Optimized geometrical structures of studied compounds were calculated by B3LYP method using 6-311++G(**) as well as LANL2DZ basis sets. Theoretical wavenumbers and intensities in IR and chemical shifts in NMR spectra were also obtained. The calculated parameters were compared with experimental data of studied compounds.
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Affiliation(s)
- M Samsonowicz
- Division of Chemistry, Bialystok University of Technology, Zamenhofa 29, 15-435 Bialystok, Poland.
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Ferro Y, Fernandez N, Allouche A, Linsmeier C. Adsorption of beryllium atoms and clusters both on graphene and in a bilayer of graphite investigated by DFT. J Phys Condens Matter 2013; 25:015002. [PMID: 23170758 DOI: 10.1088/0953-8984/25/1/015002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We herein investigate the interaction of beryllium with a graphene sheet and in a bilayer of graphite by means of periodic DFT calculations. In all cases, we find the beryllium atoms to be more weakly bonded on graphene than in the bilayer. Be(2) forms both magnetic and non-magnetic structures on graphene depending on the geometrical configuration of adsorption. We find that the stability of the Be/bilayer system increases with the size of the beryllium clusters inserted into the bilayer of graphite. We also find a charge transfer from beryllium to the graphite layers. All these results are analysed in terms of electronic structure.
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Affiliation(s)
- Yves Ferro
- Laboratoire de Physique des Interactions Ioniques et Moléculaires, Aix-Marseille Université/CNRS-UMR, Campus de Saint Jérôme, France.
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Arrowsmith M, Crimmin MR, Hill MS, Kociok-Köhn G. Beryllium derivatives of a phenyl-substituted β-diketiminate: a well-defined ring opening reaction of tetrahydrofuran. Dalton Trans 2013; 42:9720-6. [PMID: 23685744 DOI: 10.1039/c3dt51021b] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Merle Arrowsmith
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
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Frost RL, Xi Y, Scholz R, Belotti FM, Alberto Dias Menezes Filho L. Raman and infrared spectroscopic characterization of beryllonite, a sodium and beryllium phosphate mineral - implications for mineral collectors. Spectrochim Acta A Mol Biomol Spectrosc 2012; 97:1058-1062. [PMID: 22925982 DOI: 10.1016/j.saa.2012.07.067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 07/16/2012] [Accepted: 07/17/2012] [Indexed: 06/01/2023]
Abstract
The mineral beryllonite has been characterized by the combination of Raman spectroscopy and infrared spectroscopy. SEM-EDX was used for the chemical analysis of the mineral. The intense sharp Raman band at 1011 cm(-1), was assigned to the phosphate symmetric stretching mode. Raman bands at 1046, 1053, 1068 and the low intensity bands at 1147, 1160 and 1175 cm(-1) are attributed to the phosphate antisymmetric stretching vibrations. The number of bands in the antisymmetric stretching region supports the concept of symmetry reduction of the phosphate anion in the beryllonite structure. This concept is supported by the number of bands found in the out-of-plane bending region. Multiple bands are also found in the in-plane bending region with Raman bands at 399, 418, 431 and 466 cm(-1). Strong Raman bands at 304 and 354 cm(-1) are attributed to metal oxygen vibrations. Vibrational spectroscopy served to determine the molecular structure of the mineral. The pegmatitic phosphate minerals such as beryllonite are more readily studied by Raman spectroscopy than infrared spectroscopy.
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Affiliation(s)
- Ray L Frost
- School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane Queensland 4001, Australia.
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Rasoulinejad M, Izadi Najafabadi R, Ghal-Eh N. A simple well-logging tool using boron-lined sodium iodide scintillators and an 241Am-Be neutron source. Radiat Prot Dosimetry 2012; 151:580-585. [PMID: 22434921 DOI: 10.1093/rpd/ncs030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A couple of 2-inch by 2-inch right cylinder sodium iodide scintillators and an Am-Be radioisotope neutron source have been used in a neutron porosity well-logging tool to explore the variation of hydrogen contents in a prototype formation. Both Monte Carlo N-particle transport code simulation and experimental results of the near- to far-detector responses confirm the reliable sensitivity of proposed tool to the formation porosity.
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Affiliation(s)
- M Rasoulinejad
- Physics Department, School of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
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Xing Y, Zhou Y, Hu F, Chi X, Peng M. Study on mineral elements in Salvia roborwskii from the Qinghai-Tibet Plateau. Biol Trace Elem Res 2012; 148:250-4. [PMID: 22367703 DOI: 10.1007/s12011-012-9348-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2012] [Accepted: 01/26/2012] [Indexed: 11/25/2022]
Abstract
The contents of trace elements, including aluminum, barium, beryllium, calcium, cobaltium, chromium, copper, iron, potassium, lanthanum, lithium, magnesium, manganese, sodium, nickel, phosphorus, lead, sulfur, silicon, titanium, vanadium, and zinc, were determined by ICP-AES. The mean concentrations of the 22 elements were as follows: K>Ca>Mg>Fe>Al>Na>S>P>Ba>Ti>Mn>Zn>Sr>Cu>Ni=Cr>Pb>V>Li=La>Co>Be. Principal components analysis of SPSS was applied to study the characteristic elements in Salvia roborwskii. Five principal components which accounted for 89.288% of the total variance were extracted from the original data. The first factor accounted for 56.401% of the total variance, which meant that aluminum, barium, beryllium, calcium, and cobaltium were the characteristic elements in S. roborwskii. This useful new method was used to evaluate the quality of S. roborwskii, and to provide the scientific foundation for its utilization and further research.
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Affiliation(s)
- Yuxiu Xing
- Graduate School of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
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Abstract
In order to understand the common features of tetrahedral liquids with water-like anomalies, the relationship between local order and anomalies has been studied using molecular dynamics simulations for three categories of such liquids: (a) atomistic rigid-body models for water (TIP4P, TIP4P/2005, mTIP3P, SPC/E), (b) ionic melts, BeF(2) (TRIM model) and SiO(2) (BKS potential) and (c) Stillinger-Weber liquids parametrized to model water (mW) and silicon. Rigid-body, atomistic models for water and the Stillinger-Weber liquids show a strong correlation between tetrahedral and pair correlation order and the temperature for the onset of the density anomaly is close to the melting temperature. In contrast, the ionic melts show weaker and more variable degrees of correlation between tetrahedral and pair correlation metrics, and the onset temperature for the density anomaly is more than twice the melting temperature. In the case of water, the relationship between water-like anomalies and solvation is studied by examining the hydration of spherical solutes (Na(+), Cl(-), Ar) in water models with different temperature regimes of anomalies (SPC/E, TIP4P and mTIP3P). For both ionic and nonpolar solutes, the local structure and energy of water molecules is essentially the same as in bulk water beyond the second-neighbour shell. The local order and binding energy of water molecules are not perturbed by the presence of a hydrophobic solute. In the case of ionic solutes, the perturbation is largely localized within the first hydration shell. The binding energies for the ions are strongly dependent on the water models and clearly indicate that the geometry of the partial charge distributions, and the associated multipole moments, play an important role. However the anomalous behaviour of the water network has been found to be unimportant for polar solvation.
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Affiliation(s)
- B Shadrack Jabes
- Department of Chemistry, Indian Institute of Technology-Delhi, New Delhi 110016, India
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Ioannidou A. 7Be aerosols and their deposition on the sea: a possible method to estimate trace metals deposition on the sea. J Environ Radioact 2012; 108:29-32. [PMID: 22137555 DOI: 10.1016/j.jenvrad.2011.11.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 08/06/2011] [Accepted: 11/14/2011] [Indexed: 05/31/2023]
Abstract
The activity size distributions of (7)Be aerosols in different size fractions (<0.39 μm, 0.39-0.69 μm, 0.69-1.3 μm, 1.3-2.1 μm, 2.1-4.2 μm, 4.2-10.2 μm and >10.2 μm) were determined at the city of Thessaloniki, Greece, Eastern Mediterranean. The Activity Median Aerodynamic Diameter (AMAD) values ranged from 0.58 to 1.22 μm while more of the 80% of the (7)Be activity was associated with particles smaller than 1.3 μm. Sea salt aerosol particles were defined in a small size range, lower than 0.39 μm. Field measurements at a coastal location allow the estimation of (7)Be deposition on the sea. Since the (7)Be aerosol particles were mainly below 1 μm, scavenging by precipitation was the main process depositing (7)Be on the sea. Acting as an excellent tracer, (7)Be could be used for determination of the deposition of the trace metals on the sea, since they are expected to be deposited at similar rate by wet and dry deposition processes as the (7)Be.
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Affiliation(s)
- Alexandra Ioannidou
- Department of Physics, Nuclear Physics & Elementary Particle Physics Division, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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Li Q, Liu X, Li R, Cheng J, Li W. Competition between dihydrogen bond and beryllium bond in complexes between HBeH and HArF: a huge blue shift of distant H-Ar stretch. Spectrochim Acta A Mol Biomol Spectrosc 2012; 90:135-140. [PMID: 22336045 DOI: 10.1016/j.saa.2012.01.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 01/02/2012] [Accepted: 01/16/2012] [Indexed: 05/31/2023]
Abstract
A novel interaction mechanism between HArF and BeH(2) has been validated and characterized with quantum chemical calculations at the MP2/aug-cc-pVQZ level. They can interact through beryllium bonding formed between the positively charged Be atom in BeH(2) and the negatively charged F atom in HArF, besides through dihydrogen bonding. The former (61.3 kcal/mol) is much stronger than the latter (5.9 kcal/mol). The red shift is found for the associated H-Ar stretch in the dihydrogen bonding, whereas the big blue shift is observed for the distant H-Ar stretch in the beryllium bonding. The blue shift of the distant H-Ar stretch is affected greatly by computational methods. It is calculated to be 712 cm(-1) at the CCSD(T)/6-311++G(3df,2p) level, which appears to be the largest blue shift validated for any weakly bound complex yet. The substitution effect on the beryllium bond is similar to that on hydrogen bonds. The Kr atom makes the beryllium bond weaken and the distant blue shift decrease. The nature and properties of beryllium bond have been analyzed with natural bond orbital (NBO), atoms in molecules (AIM), and energy decomposition.
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Affiliation(s)
- Qingzhong Li
- The Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Yantai University, Yantai, PR China.
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Park AK, Moon JH, Lee KS, Chi YM. Crystal structure of receiver domain of putative NarL family response regulator spr1814 from Streptococcus pneumoniae in the absence and presence of the phosphoryl analog beryllofluoride. Biochem Biophys Res Commun 2012; 421:403-7. [PMID: 22521891 DOI: 10.1016/j.bbrc.2012.04.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 04/06/2012] [Indexed: 01/13/2023]
Abstract
Spr1814 of Streptococcus pneumoniae is a putative response regulator (RR) that has four-helix helix-turn-helix DNA-binding domain and belongs to the NarL family. The prototypical RR contains two domains, an N-terminal receiver domain linked to a variable effector domain. The receiver domain functions as a phosphorylation-activated switch and contains the typical doubly wound five-stranded α/β fold. Here, we report the crystal structure of the receiver domain of spr1814 (spr1814(R)) determined in the absence and presence of beryllofluoride as a phosphoryl analog. Based on the overall structure, spr1814(R) was shown to contain the typical fold similar with other structures of the receiver domain; however, an additional linker region connecting the receiver and DNA-binding domain was inserted into the dimer interface of spr1814(R), resulting in the formation of unique dimer interface. Upon phosphorylation, the conformational change of the linker region was observed and this suggests that domain rearrangement between the receiver domain and effector domain could occur in full-length spr1814.
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Affiliation(s)
- Ae Kyung Park
- Division of Biotechnology, College of Life Sciences, Korea University, Seoul 136-713, Republic of Korea
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Zhu ZL, Song QP, Kou SH, Lang JH, Sun JF. Spectroscopic parameter and molecular constant investigations on low-lying states of BeF radical. Int J Mol Sci 2012; 13:2501-2514. [PMID: 22408467 PMCID: PMC3292036 DOI: 10.3390/ijms13022501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 02/03/2012] [Accepted: 02/09/2012] [Indexed: 11/25/2022] Open
Abstract
The potential energy curves (PECs) of X2∑+, A2Πr and B2∑+ states of BeF radical have been investigated using the complete active space self-consistent-field (CASSCF) method, followed by the highly accurate valence internally contracted multireference configuration interaction (MRCI) approach at the correlation-consistent basis sets, cc-pV5Z for Be and aug-cc-pV6Z for F. Based on the PECs of X2∑+, A2Πr and B2∑+ states, the spectroscopic parameters (De, Re, ωe, ωeχe, αe and Be) have also been determined in the present work. With the PECs determined at the present level of theory, vibrational states have been predicted for each state when the rotational quantum number J equals zero (J = 0). The vibrational levels, inertial rotation and centrifugal distortion constants are determined for the three states, and the classical turning points are also calculated for the X2∑+ state. Compared with the available experiments and other theories, it can be seen that the present spectroscopic parameter and molecular constant results are more fully in agreement with the experimental findings.
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Affiliation(s)
- Zun Lue Zhu
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +86-373-332-6375; Fax: +86-373-332-6375
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Abstract
The microscopic mechanism for H and He trapping by vacancy defects and bubble formation in a Be host lattice is investigated using first-principles calculations. A single He atom prefers to occupy a vacancy centre while H does not. He can segregate towards the vacancy from the interstitial site much more easily than H. Both H and He exhibit lower diffusion barriers from a remote interstitial to a vacancy with regard to their diffusion barriers inside a perfect Be solid. Up to five H or 12 He atoms can be accommodated into the monovacancy space, and the Be-He interaction is much weaker than Be-H. The physical origin for aggregation of multiple H or He atoms in a vacancy is further discussed. The strong tendency of H and He trapping at vacancies provides an explanation for why H and He bubbles were experimentally observed at vacancy defects in materials. We therefore argue that vacancies provide a primary nucleation site for bubbles of H and He gases inside Be materials.
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Affiliation(s)
- Pengbo Zhang
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, People's Republic of China
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Shao P, Kuang XY, Zhao YR, Li YF, Wang SJ. Equilibrium geometries, stabilities, and electronic properties of the cationic Au n Be + (n = 1-8) clusters: comparison with pure gold clusters. J Mol Model 2012; 18:3553-62. [PMID: 22331107 DOI: 10.1007/s00894-012-1365-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 01/23/2012] [Indexed: 11/24/2022]
Abstract
Ab initio method based on density functional theory at PW91PW91 level has been applied in studying the geometrical structures, relative stabilities, and electronic properties of small bimetallic Au(n)Be(+) (n = 1-8) cluster cations. The geometrical optimizations indicate that a transition point from preferentially planar (two-dimensional) to three-dimensional (3D) structures occurs at n = 6. The relative stabilities of Au(n)Be(+) clusters for the ground-state structures are analyzed based on the averaged binding energies, fragmentation energies, and second-order difference of energies. The calculated results reveal that the AuBe(+) and Au(5)Be(+) clusters possess higher relative stability for small size Au(n)Be(+) (n = 1-8) clusters. The HOMO-LUMO energy gaps as a function of the cluster size exhibit a pronounced even-odd alternation phenomenon. Sequently, the natural population analysis and polarizability for our systems have been analyzed and compared further.
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Affiliation(s)
- Peng Shao
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, 610065, China.
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Sanders CJ, Smoak JM, Cable PH, Patchineelam SR, Sanders LM. Lead-210 and Beryllium-7 fallout rates on the southeastern coast of Brazil. J Environ Radioact 2011; 102:1122-1125. [PMID: 21856052 DOI: 10.1016/j.jenvrad.2011.07.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 07/12/2011] [Accepted: 07/24/2011] [Indexed: 05/31/2023]
Abstract
Total ²¹⁰Pb and ⁷Be fallout rates were measured on the coastal region of Niteroi, Brazil. The monthly depositional flux of ²¹⁰Pb and ⁷Be varied by a factor of 26, from 1.7 to 43.3 mBq cm⁻² year⁻¹ and ∼27, from 7.5 to 203.5 mBq cm⁻² year⁻¹, respectively. The relatively large oscillations in the depositional flux of ²¹⁰Pb at this study site were likely due to variations in air mass sources, while the ⁷Be fluctuations may be driven by a combination of weather conditions. Local geology could support the periodic high fluxes of ²¹⁰Pb from continental air masses, as shifting oceanic wind sources were affirmed by the uncorrelated ²¹⁰Pb and ⁷Be fallout activities and ⁷Be/²¹⁰Pb ratios. The ²¹⁰Pb atmospheric deposition was found to be in agreement with local sediment inventories, an important consideration in geochemical studies that estimate sedimentation processes.
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Affiliation(s)
- Christian J Sanders
- Universidade Federal de Fluminense (UFF), Departamento de Geoquímica, Outeiro de Sao Joao Baptista s/n, Morro do Valonguinho Centro, Niterói, RJ, Brazil.
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Samsonowicz M, Regulska E, Lewandowski W. Influence of alkaline earth metals on molecular structure of 3-nitrobenzoic acid in comparison with alkali metals effect. Spectrochim Acta A Mol Biomol Spectrosc 2011; 82:235-246. [PMID: 21862395 DOI: 10.1016/j.saa.2011.07.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 05/27/2011] [Accepted: 07/13/2011] [Indexed: 05/31/2023]
Abstract
The influence of beryllium, magnesium, calcium, strontium and barium cations on the electronic system of 3-nitrobenzoic acid was studied in comparison with studied earlier alkali metal ions. The vibrational FT-IR (in KBr and ATR techniques) and (1)H and (13)C NMR spectra were recorded for 3-nitrobenzoic acid and its salts. Characteristic shifts in IR and NMR spectra along 3-nitrobenzoates of divalent metal series Mg→Ba were compared with series of univalent metal Li→Cs salts. Good correlations between the wavenumbers of the vibrational bands in the IR spectra for 3-nitrobenzoates and ionic potential, electronegativity, inverse of atomic mass, atomic radius and ionization energy of metals were found for alkaline earth metals as well as for alkali metals. The density functional (DFT) hybrid method B3LYP with two basis sets: 6-311++G** and LANL2DZ were used to calculate optimized geometrical structures of studied compounds. The theoretical wavenumbers and intensities of IR spectra as well as chemical shifts in NMR spectra were obtained. Geometric aromaticity indices, atomic charges, dipole moments and energies were also calculated. The calculated parameters were compared to experimental characteristic of studied compounds.
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Affiliation(s)
- M Samsonowicz
- Division of Chemistry, Bialystok University of Technology, Zamenhofa 29, 15-435 Bialystok, Poland.
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Wesełucha-Birczyńska A, Słowakiewicz M, Natkaniec-Nowak L, Proniewicz LM. Raman microspectroscopy of organic inclusions in spodumenes from Nilaw (Nuristan, Afghanistan). Spectrochim Acta A Mol Biomol Spectrosc 2011; 79:789-796. [PMID: 20884283 DOI: 10.1016/j.saa.2010.08.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 07/11/2010] [Accepted: 08/26/2010] [Indexed: 05/29/2023]
Abstract
The color varieties of spodumene (green spodumene, kunzite) from Nilaw mine (Nuristan, Afghanistan) have been investigated by microthermometry and Raman spectroscopy analyses. These minerals are rich in primary and secondary fluid inclusions. Measured values of temperature homogenization (T(h)) and pressure (P) for selected fluid-inclusion assemblages (I-IV) FIA in green spodumene and (I-II) FIA in kunzite ranges from 370 to 430°C, 1.16 to 1.44 kbar and 300 to 334°C, 0.81 to 1.12 kbar, respectively. The brine content and concentration varies from 4.3 to 6.6 wt.% eq. NaCl. Numerous and diverse mineral phases (quartz, feldspars, mica, beryl, zirconium, apatite, calcite, gypsum) present in this mineral as solid inclusions were studied by Raman microspectroscopy. Raman spectra of selected fluid, organic and solid inclusions were collected as line or rectangular maps and also depth profiles to study their size and contents. There appeared very interesting calcite (156, 283, 711 and 1085 cm(-1)), beryl (324, 397, 686, 1068 and 3610 cm(-1)), topaz (231, 285, 707, 780 and 910 cm(-1)) and spodumene (355, 707 and 1073 cm(-1)) inclusions accompanied by fluid and/or organic inclusions (liquid and gas hydrocarbons) with bands at 2350 cm(-1) (CO(2), N(2)), 2550 cm(-1) (H(2)S) and 2900 cm(-1) (C(2)H(6)-CH(3)). Some solid inclusions contain carbonaceous matter (D-band at ca. 1320 cm(-1) and/or G-band at ca. 1600 cm(-1)).
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Stefaniak AB, Virji MA, Day GA. Dissolution of beryllium in artificial lung alveolar macrophage phagolysosomal fluid. Chemosphere 2011; 83:1181-1187. [PMID: 21251696 DOI: 10.1016/j.chemosphere.2010.12.088] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 12/22/2010] [Accepted: 12/27/2010] [Indexed: 05/30/2023]
Abstract
Dissolution of a lung burden of poorly soluble beryllium particles is hypothesized to be necessary for development of chronic beryllium lung disease (CBD) in humans. As such, particle dissolution rate must be sufficient to activate the lung immune response and dissolution lifetime sufficient to maintain chronic inflammation for months to years to support development of disease. The purpose of this research was to investigate the hypothesis that poorly soluble beryllium compounds release ions via dissolution in lung fluid. Dissolution kinetics of 17 poorly soluble particulate beryllium materials that span extraction through ceramics machining (ores, hydroxide, metal, copper-beryllium [CuBe] fume, oxides) and three CuBe alloy reference materials (chips, solid block) were measured over 31 d using artificial lung alveolar macrophage phagolysosomal fluid (pH 4.5). Differences in beryllium-containing particle physicochemical properties translated into differences in dissolution rates and lifetimes in artificial phagolysosomal fluid. Among all materials, dissolution rate constant values ranged from 10(-5) to 10(-10)gcm(-2)d(-1) and half-times ranged from tens to thousands of days. The presence of magnesium trisilicate in some beryllium oxide materials may have slowed dissolution rates. Materials associated with elevated prevalence of CBD had faster beryllium dissolution rates [10(-7)-10(-8)gcm(-2)d(-1)] than materials not associated with elevated prevalence (p<0.05).
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Affiliation(s)
- Aleksandr B Stefaniak
- National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, 1095 Willowdale Road, Mail Stop H-2703, Morgantown, WV 26505, USA.
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Zhao YR, Kuang XY, Zheng BB, Wang SJ, Li YF. Ab initio calculation of the geometries, stabilities, and electronic properties for the bimetallic Be2Au n (n = 1–9) clusters: comparison with pure gold clusters. J Mol Model 2011; 18:275-83. [PMID: 21523544 DOI: 10.1007/s00894-011-1051-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Accepted: 03/18/2011] [Indexed: 11/28/2022]
Affiliation(s)
- Ya-Ru Zhao
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, China
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46
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Bazeliuk LT, Sadykov KB. [Structural and functional-metabolic criteria for studies of bronchial lavage cells in beryllium production workers]. Med Tr Prom Ekol 2011:12-16. [PMID: 22180971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The article presents results of cytomorphologic and cytochemical studies of bronchoalveolar lavage cells in experimental animals and in beryllium production workers having beryllium intoxication signs. Findings are increased counts of degenerated neutrophils and macrophages in bronchial lavage, high degree of microbial (streptococcal and staphylococcal) contamination in workers having atrophic bronchitis, low levels of catecholamines and esterase activity, high content of phospholipids, if compared to apparently healthy individuals. These tests are expedient to use in early diagnosis among beryllium production workers.
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47
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National Toxicology Program. Beryllium and beryllium compounds. Rep Carcinog 2011; 12:67-70. [PMID: 21850112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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48
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James JP, Ravi PM, Joshi RM, Hegde AG, Sarkar PK. Estimation of site-specific deposition velocities and mass interception factor using 7Be and the prediction of deposition pattern of radionuclides at Kaiga site, India. Radiat Prot Dosimetry 2010; 141:248-254. [PMID: 20616111 DOI: 10.1093/rpd/ncq171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Site-specific wet, dry deposition velocities and mass interception factors at Kaiga site, where three PHWR type power plants are operational, using 7Be as a tracer are presented. Mean wet and dry deposition velocities for Kaiga site were found to be 7.4 x 10(-2) m s(-1) and 3.0 x 10(-4) m s(-1), respectively. Mass interception factors for vegetation were found to be 0.7-5.6 m(2) kg(-1) dry weight with a mean of 2.4 m(2) kg(-1) dry weight. The site-specific data were used for the prediction of radionuclide distribution pattern in soil and vegetation in the case of a hypothetical air contamination.
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Affiliation(s)
- J P James
- Environmental Survey Laboratory, Kaiga Generating Station, (Health Physics Division, BARC), Kaiga, Uttar Kannada District, Karwar, Karnataka 581400, India.
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Kikas A, Käämbre T, Kooser K, Kuusik I, Kisand V, Nõmmiste E, Kirm M, Feldbach E, Ivanov V, Pustovarov V, Martinson I. Resonant inelastic x-ray scattering and UV-VUV luminescence at the Be 1s edge in BeO. J Phys Condens Matter 2010; 22:375505. [PMID: 21403201 DOI: 10.1088/0953-8984/22/37/375505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We carried out a combined study of UV-VUV luminescence and resonant x-ray emission from BeO single crystals with incident photon energies in the vicinity of the Be 1s absorption edge. The x-ray emission spectra show that at the Be 1s photoabsorption edge the lattice relaxation processes in the excitation site take place already on the timescale of the radiative decay of the core excitation. Comparison of the x-ray emission and the luminescence spectra indicates that the maximum energy loss of the process of lattice relaxation during the decay of inner-shell holes is similar to the loss that occurs in the self-trapping process of valence excitons. The possible decay channels of core excitations have been discussed and the mechanism for the creation of 5.2 eV luminescence at the photoabsorption resonances has been suggested.
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Affiliation(s)
- A Kikas
- Institute of Physics, University of Tartu, Tartu, Estonia.
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50
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Zhang ZY, Jiang Q, Hopkinson M, Hogg RA. Effects of intermixing on modulation p-doped quantum dot superluminescent light emitting diodes. Opt Express 2010; 18:7055-7063. [PMID: 20389726 DOI: 10.1364/oe.18.007055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Different capping of quantum dot (QD) materials is known to produce different degrees of intermixing during a post-growth thermal annealing process. We report a study of the effect of different degrees of intermixing on modulation beryllium doped quantum dot superluminescent light emitting diodes (QD-SLEDs). The intermixed QD-SLEDs show high device performance whilst achieving a large central emission wavelength shift of approximately 100nm compared to the as-grown device. The evolution of the emission spectra and power with drive current suggest a transition from QD-like to QW-like behavior with increasing degree of intermixing. A selective area intermixed QD-SLED is demonstrated, and with optimized differential intermixing, such structures should allow ultra-broadband sources to be realized.
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Affiliation(s)
- Z Y Zhang
- Department of Electronic and Electrical Engineering, University of Sheffield, Sir Frederick Mappin Building, Mappin Street, Sheffield, S1 3JD, UK.
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