1,720,977 research outputs found
Use of PIXE analysis technique for the study of Beirut amphora production in the Roman period
No full textIon Beam Analysis techniques were developed and utilized for applications in the domain of archeology at the accelerator laboratory of the Lebanese Atomic Energy Commission. The characterization of Beirut kiln materials, mainly amphorae ceramics from the Roman period, was done using PIXE technique. In two runs with 1 and 3 MeV protons, we measured 20 major and trace elements. Consequently, a classification based on the elemental composition and on multivariate statistical techniques of some 70 ceramic objects was obtained providing the first step of a Lebanese database for future studies. Furthermore, the analysis of carrot amphorae found in Gaul (south of France) showed that some of them were of Beirut products and hence emphasized the role of Beirut city in the Mediterranean trade in the Roman period. © 2003 Elsevier B.V. All rights reserved.Carreras Monfort C., 2002, ROMAN BYZANTINE E, V3, P133; Everitt BS, 1993, CLUSTER ANAL; FRANCOIS V, 1999, 7 C INT CER MED MED, V11, P325; GORDON AD, 1980, CLASSIFICATION; JOHANSSON SAE, 1995, CAMPBELL PARTICLE IN; LAHANIER C, 1986, NUCL INSTRUM METH B, V14, P1, DOI 10.1016-0168-583X(86)90414-3; LEMAITRE S, 2000, REI CRETAR FAUTOR AC, V36, P467; MARTINKILCHER S, 1994, ROMISCHEN AMPHOREN A; MAXWELL JA, 1989, NUCL INSTRUM METH B, V43, P218, DOI 10.1016-0168-583X(89)90042-6; Peacock D.P.S., 1986, AMPHORAE ROMAN EC; PICON M, 1987, REV ARCHEOMETRIE, V11, P41; Picon M., 1984, PACT, V10, P379; REYNOLDS P, 2003, ARCHAEOL HIST LEBANO, V17, P120; REYNOLDS P, 1999, BERYTUS, V43, P35; REYNOLDS P, 2000, REI CRETARIAE ROMANA, P387; ROUMIE M, 2003, IN PRESS 16 INT C IO; van Doorninck Jr F.H, 1989, REV ARCHEOMETRIE, P247; VIPARD P, 1995, C ROUEN MARS, P51; WAKSMAN SY, 1994, NUCL INSTRUM METH B, V85, P824, DOI 10.1016-0168-583X(94)95931-5; WAKSMAN SY, 2002, IN PRESS P 1 INT C L86
PIXE identification of fine and coarse particles of aerosol samples and their distribution across Beirut
No full textThis study is the first national attempt to assess the levels of PMs in Beirut city and consequently understand air pollution distribution. Aerosol sampling was carried out using three PM10 and three PM2.5 samplers which were installed at three locations lying along the SE-NW direction over Beirut. The sampling of PM10 and PM2.5 was done during a period extending from May till December 2009. The random collection of the particles (1 in 6 days) was carried out on Teflon filters, for a period of 24-h. The elemental analysis of particulate matter was performed using proton induced X-ray emission technique PIXE at the Lebanese 1.7 MV Tandem-Pelletron accelerator of Beirut. Na, Mg, Al, Si, P, S and Cl were quantified using 1 MeV proton beam, while K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn and Pb were determined using 3 MeV-energy of proton beam. © 2011 Elsevier B.V. All rights reserved.ABBOUD M, 2010, AIR RES QUALITY UNIT; Johansson S.A.E., 1995, PARTICLE INDUCED XRA; MAXWELL JA, 1995, NUCL INSTRUM METH B, V95, P407, DOI 10.1016-0168-583X(94)00540-0; Pinto JP, 2004, J AIR WASTE MANAGE, V54, P440; Roumie M., 2004, NUCL INSTRUMENTS M B, V389, P219; Saliba NA, 2007, ATMOS ENVIRON, V41, P6497, DOI 10.1016-j.atmosenv.2007.04.032; Saliba NA, 2010, ENVIRON SCI ENG, P3, DOI 10.1007-978-3-642-12278-1_1; Shaka' H, 2004, ATMOS ENVIRON, V38, P523, DOI 10.1016-j.atmosenv.2003.10.009; WHO, 2006, WHO AIR QUAL GUID PA0
Effect of deposition temperature on the properties of sputtered YIG films grown on quartz
No full textYttrium Iron Garnet (YIG), Y3Fe5O12, is an oxide material that has potential applications in the magneto-optical recording media and microwave device industries. These materials, when synthesized in thin film form, usually require post-deposition annealing in order to enhance their physical properties. Furthermore, integration of YIG based optical components requires the synthesis of high quality YIG material on quartz, a process that may be problematic due to poor adhesion and lattice mismatch. Thus, we have conducted a study on the effect of deposition temperature (from 25 to 800 °C) and post-deposition annealing (at 740 °C) on the crystalline quality and chemical composition of YIG thin films, grown by radio-frequency magnetron sputtering, on quartz substrates. X-ray diffraction (XRD) shows that as-grown layers are amorphous, and subsequent annealing is necessary to induce film crystallization. Rutherford backscattering spectrometry analyses were also conducted and the chemical composition of the films was found to depend on initial deposition temperature and is affected by post-deposition anneals. Comparison of the XRD and RBS results point out to the existence of an optimal deposition temperature at about 700 °C for the formation of high crystalline quality and stoichiometric YIG thin films. Magnetic measurements were found to correlate to the XRD and RBS analyses. © 2010 Elsevier B.V. All rights reserved.Amsel G, 2005, NUCL INSTRUM METH B, V240, P1, DOI 10.1016-j.nimb.2005.06.078; Bahlmann N, 1998, ELECTRON LETT, V34, P2122, DOI 10.1049-el:19981485; Bohra M, 2006, APPL PHYS LETT, V88, DOI 10.1063-1.2217253; Boudiar T, 2004, J MAGN MAGN MATER, V284, P77, DOI 10.1016-j.jmmm.2004.06.046; DUMONT Y, 2005, J APPL PHYS, V97; Grosseau P, 1996, J THERM ANAL, V46, P1633, DOI 10.1007-BF01980769; Guo XZ, 2005, J MAGN MAGN MATER, V295, P145, DOI 10.1016-j.jmmm.2005.01.007; Guo XZ, 2006, CERAM INT, V32, P61, DOI 10.1016-j.ceramint.2005.02.001; Kahl S, 2003, J APPL PHYS, V93, P6945, DOI 10.1063-1.1543855; KANG YM, 2005, J APPL PHYS, V97, P1; Kumar N, 2004, J MAGN MAGN MATER, V272, pE899, DOI 10.1016-j.jmmm.2003.12.223; Kumar N, 2008, J MAGN MAGN MATER, V320, P2233, DOI 10.1016-j.jmmm.2008.04.112; Mayer M., 1997, 9113 IPP M PLANCK I; Park MB, 2001, J MAGN MAGN MATER, V231, P253, DOI 10.1016-S0304-8853(01)00068-3; Popova E, 2001, J APPL PHYS, V90, P1422, DOI 10.1063-1.1379344; Roumie M, 2004, NUCL INSTRUM METH B, V219, P389, DOI 10.1016-j.nimb.2004.01.088; Sozeri H, 2009, MATER CHEM PHYS, V113, P977, DOI 10.1016-j.matchemphys.2008.08.079; SUNG SY, 2005, APPL PHYS LETT, V87; Ustinov AB, 2006, J APPL PHYS, V100, DOI 10.1063-1.2372575; Xu ZC, 2006, J MAGN MAGN MATER, V307, P74, DOI 10.1016-j.jmmm.2006.03.04222
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Origin and variability of particulate matter (PM10 and PM2.5) mass concentrations over an Eastern Mediterranean city
No full textBeing a semi-enclosed area, the Eastern Mediterranean region experiences high Particulate Matter (PM) levels that could be attributed to sources originating from the region and from long-range transported pollutants. In this study, a long-term evaluation of PM10 and PM2.5 mass concentrations reveals that averages of PM10 and PM2.5 concentrations collected between 2003 and 2007 in several different sites in Beirut exceeded the World Health Organization (WHO) PM10 and PM2.5 annual averages (20 and 10μgm-3, respectively). When compared to other sites in the region, levels fell in general outside the usual range for most other urban sites that are not directly affected by industrial activity. The average PM2.5-PM10 ratios were about 0.42, a value that is typical of urban sites. The overall averages for different seasons were higher in fall and summer as a result of low precipitations, the increase of dust storm activities in fall and the enhancement of sea and land breezes in summer, along with the increase in traffic activities (summer is a high touristic season). Using the HYSPLIT model for about 500 sampled days in Beirut, Lebanon, it was found that 60percent of the wind comes from the N, NW and NE, while the remaining 40percent comes from the S, SW and SE. Comparing the sources assigned to the pre- (BH) and post- (HH) 2006-war sites, it was found that aged dust increased by 64percent in total PM10 and secondary aerosols by 150percent in fine PM in HH over BH. Furthermore, much higher average percentages of sulfates and nitrates were determined in fine PMs in HH, indicating increased levels of their precursors NOx, SOx and Ca generated from a higher density of gasoline, diesel vehicles and construction debris. © 2010 Elsevier B.V.Abu-Allaban M, 2007, ENVIRON MONIT ASSESS, V133, P417, DOI 10.1007-s10661-006-9596-8; Abu-Allaban M, 2006, J AIR WASTE MANAGE, V56, P1440; BLEEKER W, 1960, UNESCO WMO SEM MED S; Chaloulakou A, 2003, ATMOS ENVIRON, V37, P649, DOI 10.1016-S1352-2310(02)00898-1; Draxler R.R., 2003, HYSPLIT HYBRID SINGL; ELHASAN T, 2008, ENVIRON GEOL, P103; Erel Y, 2006, ENVIRON SCI TECHNOL, V40, P2996, DOI 10.1021-es051502l; Freiman MT, 2006, ATMOS ENVIRON, V40, P5670, DOI 10.1016-j.atmosenv.2006.04.060; Gerasopoulos E, 2007, ATMOS CHEM PHYS, V7, P2551; Gerasopoulos E, 2006, ATMOS ENVIRON, V40, P4679, DOI 10.1016-j.atmosenv.2006.04.020; Glavas SD, 2008, ATMOS ENVIRON, V42, P5365, DOI 10.1016-j.atmosenv.2008.02.055; Graham B, 2004, ATMOS ENVIRON, V38, P1593, DOI 10.1016-j.atmosenv.2003.12.015; Guerzoni S., 1990, WATER POLLUTION RES, V20, P377; Kocak M, 2007, ATMOS ENVIRON, V41, P3806, DOI 10.1016-j.atmosenv.2007.01.009; Kocak M, 2007, J ATMOS CHEM, V56, P239, DOI 10.1007-s10874-006-9053-7; Kouyoumdjian H, 2006, ATMOS CHEM PHYS, V6, P1865; Lazaridis M, 2008, WATER AIR SOIL POLL, V189, P85, DOI 10.1007-s11270-007-9558-y; MAXWELL JA, 1989, NUCL INSTRUM METH B, V43, P218, DOI 10.1016-0168-583X(89)90042-6; Mihalopoulos N, 1997, TELLUS B, V49, P314, DOI 10.1034-j.1600-0889.49.issue3.7.x; Millan MM, 2002, ENVIRON POLLUT, V118, P167, DOI 10.1016-S0269-7491(01)00311-6; Millan MM, 1997, J GEOPHYS RES-ATMOS, V102, P8811, DOI 10.1029-96JD03610; Moreno T, 2006, ATMOS ENVIRON, V40, P6791, DOI 10.1016-j.atmosenv.2006.05.074; Paatero P., 1997, CHEMOMETRICS INTELLI, V37, P15; Peled R, 2005, PUBLIC HEALTH, V119, P418, DOI 10.1016-j.puhe.2004.05.023; PEY J, 2008, ATMOSPHERIC ENV, V42; Querol X, 2008, ATMOS ENVIRON, V42, P3964, DOI 10.1016-j.atmosenv.2006.10.071; Querol X, 2001, ATMOS ENVIRON, V35, P6407, DOI 10.1016-S1352-2310(01)00361-2; Rodriguez S, 2001, ATMOS ENVIRON, V35, P2433, DOI 10.1016-S1352-2310(00)00496-9; Rodriguez S, 2003, ENVIRON SCI TECHNOL, V37, P216, DOI 10.1021-es020106p; Roumie M., 2004, NUCL INSTRUMENTS M B, V389, P219; SALIBA NA, URBAN AIRBO IN PRESS; Saliba NA, 2007, ATMOS ENVIRON, V41, P6497, DOI 10.1016-j.atmosenv.2007.04.032; WHO, 2006, WHO AIR QUAL GUID PA; Yatkin S, 2008, SCI TOTAL ENVIRON, V390, P109, DOI 10.1016-j.scitotenv.2007.08.05923262
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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