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Abstract  

The characteristic scores and scales (CSS), introduced by Glänzel and Schubert (J Inform Sci 14:123–127, <cite>1988</cite>) and further studied in subsequent papers of Glänzel, can be calculated exactly in a Lotkaian framework. We prove that these CSS are simple exponents of the average number of items per source in general IPPs. The proofs are given using size-frequency functions as well as using rank-frequency functions. We note that CSS do not necessarily have to be defined as averages but that medians can be used as well. Also for these CSS we present exact formulae in the Lotkaian framework and both types of CSS are compared. We also link these formulae with the h-index.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: Luís dos Santos, Márcio Bacchi, Elisabete De Nadai Fernandes, and Simone da Silva Cofani dos Santos

Abstract  

As a non-destructive and multi-element technique, with high-level metrological properties, instrumental neutron activation analysis (INAA) has an important role to determine chemical elements in food. However, its use may be limited when looking for mass fractions near the detection limits. The Compton scattering of higher energy gamma-rays raised the spectrum baseline thus impairing the determination of several elements. Therefore, the gamma-ray spectrometry with Compton suppression becomes an alternative for improving the performance of INAA, since it can reduce the uncertainty of measurements and the detection limits by increasing the proportion between photopeak area and baseline. Here the performance of a Compton suppression system set by Ortec, with 50% relative efficiency and 2.04 keV resolution (FWHM) for the 1,332 keV photopeak, was evaluated for food analysis. Samples of beans, chickpeas, lentils, peas, and rice were irradiated with neutrons and measured in the suppression system. Detection limits calculated from suppressed and unsuppressed spectra were compared. The suppression factor achieved by the system for 137Cs was 5.88 ± 0.11 (n = 20) in the plateau region (358 to 382 keV), which was stable along a 20 week period and similar to the data provided in literature for other systems. Amongst fifteen elements determined, the detection limits for Br, Co, La, Na, Sc, and Se were not improved by the use of Compton suppression. On the other hand, the variable improvement obtained for As, Ca, Cd, Cr, Fe, Hg, K, Rb, and Zn corroborated the idea that the performance of the Compton suppressor must be individually assessed for each type of sample.

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EU-FP7 Project CSS (2009): Civil Society and Sustainability. Kick-off Report . Stuttgart. Petschow, U.–Rosenau, J.–von Weizsäcker, E. U. (szerk.) (2005): Governance and Sustainability – New

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Scientometrics
Authors: Pedro Albarrán, Juan A. Crespo, Ignacio Ortuño, and Javier Ruiz-Castillo

(CSS hereafter) technique that permits the partition of any distribution of articles into a number of classes as a function of their members’ citation characteristics. However, no statistical test of the presence of common characteristics at this level

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.2 ± 11.0 Mean segmental LV 3DS (%) 28.8 ± 10.0 Correlations Regarding segmental LV-CSs, only that of all apical segments and midventricular anteroseptal segments correlated

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Abstract  

Chemical separation methods in conjunction with instrumental neutron activation analysis (INAA) were developed for measuring iodine levels in commercially available bovine milk with varying milk fat (MF) content. Samples of homogenized (3.25 % MF), partly skimmed (2 % MF), partly skimmed (1 % MF), partly skimmed calcium enriched (1 % MF + Ca), and skim (<0.05 %) milk were purchased from local supermarkets. Ion exchange chromatography, solvent extraction, and ammonium sulfate precipitation methods were applied to the separation of the inorganic, lipidic and proteic fractions of iodine in milk. The levels of iodine were measured by INAA in total reactor and epi-cadmium (EINAA) neutron flux in conjunction with conventional gamma-ray and Compton suppression spectrometry (CSS). A pseudo-cyclic INAA method coupled with CSS (PC-INAA-CSS) was also explored as an instrumental option to further lower the detection limit of iodine. The detection limits of 0.06, 0.06 and 0.02 μg mL−1 for iodine were obtained using INAA-CSS, EINAA-CSS, and PC-INAA-CSS methods, respectively. Although the PC-INAA-CSS method provided the lowest detection limit, the INAA-CSS method was sufficient for the determination of total iodine in almost all samples analyzed in this work. The total iodine concentrations (μg mL−1) were: 0.40 ± 0.01 (in 3.25 % MF), 0.40 ± 0.01 (2 % MF), 0.42 ± 0.01 (1 % MF), 0.42 ± 0.01 (<0.05 %), and 0.96 ± 0.01 (1 % MF + Ca) milk samples. Iodine bound to various fractions of the milk samples analyzed, in percent of total iodine content, ranged: (0.05–1.8), (1.9–4.8), (90–95) for the lipidic, proteic and anionic inorganic fractions respectively. Iodine recovery in all cases was higher than 96 %.

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Abstract  

A new Compton suppression system (CSS) for the gamma-ray spectrometer portion of the neutron activation analysis (NAA) was set up at the RPI/ITN. The pneumatic transfer system, SIPRA, for short-lived nuclides and cyclic irradiations was improved. A full calibration procedure of the CSS and SIPRA systems was performed. Two certified reference materials, NIST-SRM-1572 (Citrus Leaves) and NIST-SRM-1633a (Coal Fly Ash) were analyzed using the calibration factors. The CSS was instrumental in lowering the detection limits of Cr, Fe, Hg, Rb, Sr, Th and Zn by reducing background and/or spectral interference considerably. The analytical results were evaluated by comparison to the NIST certified values with deviations ranging from 2% to 8% for the above mentioned elements, except Zn ranging from 10% to 15% for biological and environmental samples, respectively.

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Abstract  

The effectiveness of a Compton suppression system (CSS) for instrumental neutron activation analysis of plant materials was evaluated. Suppression factors were measured with 137Cs sources. Five certified reference materials were analyzed and the detection limits calculated from both suppressed and unsuppressed spectra were compared. The CSS demonstrated to be useful for lowering the detection limits of ten out of sixteen elements tested, showing a maximum improvement factor of 3.9. The system performance was strongly influenced by the sample composition and also by the measurement conditions, indicating the importance of testing each individual sample type and analytical protocol.

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Abstract  

The Compton suppression system (CSS) has been thoroughly characterized at the University of Texas’ Nuclear Engineering Teaching Laboratory (NETL). Effects of dead-time, sample displacement from primary detector, and primary energy detector position relative to the active shield detector have been measured and analyzed. Also, the applicability of Poisson counting statistics to Compton suppression spectroscopy has been evaluated.

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Az MTA Szociológiai Kutatóintézet (MTA SZKI) és az ENERGIAKLUB Szakpolitikai Intézet és Módszertani Központ (EK) 2009 óta részt vesz az EU 7 Keretprogramja által finanszírozott Civil Társadalom a Fenntarthatóságért (Civil Society for Sustainability, CSS) című kutatási projektben. A projekt fő célja, hogy EU szinten kapcsolatot teremtsen a civil társadalom és a fenntartható fejlődéssel foglalkozó kutatók között. Segíteni kívánja a civil szervezetek és a kutatási intézmények közötti együttműködést, többek között olyan civil társadalom központú kutatási projektek formájában, amelyek a fenntartható fejlődést célozzák. A projektben 4 országból 3 kutatócsoport és 3 civil szervezet vesz részt. Ezek páronként ún. tandemeket alkotnak, amelyek a következők: Dialogik gGmbH (Stuttgart) – unw e.V. (Ulm); Mutadis SARL (Párizs) – REC Slovenija (Lubljana); illetve MTA SZKI – EK. A projekt 1. fázisának eredményeit (az EK stratégiai problémáinak feltárása) korábban e folyóirat hasábjain közöltük. Jelen cikkünkben egy olyan mintaprojektet mutatunk be, amely Gyöngyös város éghajlatvédelmi stratégiájának kifejlesztését célozta, s amely a CSS projekt második fázisában valósult meg.

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