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Abstract
Radioaactive samples in cylindrical beakers have been measured using a high purity Ge spectrometer. Self-attenuation effects at various densities of the radioactive samples filled in cylindrical beakers were studied by experimenal and theoretical methods. Coincidence summing effects for specific nuclides were also determined from the measurements of full-energy peak efficiencies in a given source-to-detector geometry.
Abstract
Very low concentrations of many elemental impurities are determined in a lead matrix by spark-source mass spectrometry using photoplate detection. In order to obtain semiquantitative results, at least one element /antimony/ should be accurately determined by an independent technique such as atomic absorption spectroscopy in order to be used as an internal standard.
Abstract
The following problem has never been studied : Given A, the total number of items (e.g. articles) and T, the total number of sources (e.g. journals that contain these articles) (hence A>T), when is there a Lotka function.
Summary
NPL was recently asked to provide reference sources containing &-ray emitting fission product radionuclides, with certification completed within 50 days of the irradiation. Furthermore, the reference sources were to contain fission products, but no fissile material. The samples in the first reference source were to contain a mixture of fission products with only the 235U removed, leaving the fission products as 'undisturbed' as possible. A number of radionuclides were reported in this sample and included: 91Y, 95Zr, 95mNb, 95gNb, 99Mo, 99mTc, 103Ru, 106Ru, 127Sb, 129mTe, 129gTe, 131I,132Te, 132I, 137Cs, 140Ba, 140La, 141Ce, 144Ce, and147Nd. Of these nuclides, NPL provided certified values for 91Y, 95Zr, 95mNb, 95gNb, 99Mo, 99mTc, 103Ru, 106Ru, 132Te, 132I, 137Cs, 140Ba, 140La, 141Ce, 144Ce, and 147Nd. The second reference source focused on a smaller subset of radionulides: 95Zr, 99Mo, 103Ru, 106Ru, 140Ba, and 155Eu, although 95gNb, 99mTc, 132I and 140La were present as daughter radionuclides and 91Y, 127Sb, 129mTe, 129gTe, 131I, 132Te, 137Cs, 152Eu and 154Eu were present as impurities. This paper describes the preparation of these sources, based on a combination of cation- and anion-exchange chromatography with selective precipitation. The separation techniques were used to (1) produce the 'fresh' fission product mixture from irradiated 235U, and (2) isolate the specific set of radionuclides in the second exercise from mixtures containing irradiated 235U and fission products. To enable accurate assay of parent-daughter systems, integrated ingrowth and decay equations were derived from original Bateman equations and tested by observing the 140Ba-140La system over time.
Abstract
A new computing algorithm has been developed to calculate the correction coefficient for a voluminous radiation source. The algorithm is based on the conception of a virtual efficiency center whose detector location depending on the radiation energy can be computed relatively to a point arbitrarily fixed on the detector axis. A scheme for the interaction of the gamma-radiation with the detector is proposed to minimize the number of preliminary experiments for the determination of empirical functions needed for realization of the method. Data are presented for computation of the linear attenuation coefficient of any material with known chemical composition and density. The validity of the developed approach has been proved by comparison of real and computed radioactivities for 5 different radiation energies in 12 cylindrical source-detector geometries.
The chemical composition and thermal behaviour of crab, shrimp and lobster shells were studied. The lobster cephalothorax and its main parts also constitute important sources of both polymers. Their chitin and protein content are 20 and 40 %, respectively (dry base) while in these cases the proteins are less associated to the matrix than in the carapace. The chitin level in the chitinous concentrates isolated from different sources is over 80 % in all cases but the polymer characteristics change in dependence on the raw material.
Abstract
Concentrations of elements and ions, measured in aerosol samples collected during 1993 were investigated to identify sources and source composition of aerosols in the Eastern Mediterranean atmosphere. The factor analysis have shown that Eastern Mediterranean aerosol is a four-component system, including a crustal component, long-range transported pollution component, a marine component and a local pollution component. Main anthropogenic component, which reaches to the region by long-range transport accounts for 70%-90% of the concentrations of Zn, Se, NO3-, nss-SO4 2-, NH4 + and smaller fractions of V, Sb, Cr and Mn concentrations. According to the quantitative analysis of local and Saharan dust components, the most promising marker elements to distinguish Saharan dust from local soil were found to be Cr, Nd, Mg and Cs as they have significantly different compositions in the local soil and Saharan dust.
The “Genealogy of the Tatar Sovereigns” ( Rodoslovnaia tatarskikh tsarei ) preserved in various (official and private) genealogical books of the 16th–17th centuries is a unique and precious monument of both Tatar and Russian history. This text owes its existence to the lively interest of the Russian state in the inner relations of the declining Tatar states towards the middle of the 16th century. Its genesis cannot be disconnected from the Russian conquests of Kazan and Astrakhan. The bulk of the genealogies was compiled in the 1550s and based on Tatar sources. A critical analysis of these genealogies, comparing every piece of data with other contemporary (Russian and Oriental) sources, is a task yet to be accomplished, but the significance of these texts is beyond doubt. What I tried to do in this paper was to emphasise and analyse a few noteworthy aspects of this group of monuments.
Abstract
The true coincidence summing (TCS) effect on the full energy peak (FEP) efficiency calibration of an HPGe detector has been studied as a function of sample-to-detector distance using multi-gamma sources. Analytical method has been used to calculate coincidence correction factors for 152Eu, 133Ba, 134Cs and 60Co for point and extended source geometry at close sample-to-detector distance. Peak and total efficiencies required for this method have been obtained by using MCNP code by using the optimized detector geometry. The correction factors have also been obtained experimentally. The analytical and the experimental correction factors have been found to match within 1–5%. The method has been applied to obtain the activity of the radionuclides (106Ru, 125Sb, 134Cs and 144Ce) present in a fission product sample.
Although journalistic translation research has been quite successful over the past 15 years, from a methodological point of view many scholars struggle with the total or partial absence of a traceable source text. As a consequence, parallel corpora are rare and the researcher often has to rely on multilingual sets of texts that are comparable. This contribution deals in detail with that essential methodological problem. It relates the multisource and multi-author situation of translation in journalism to this non- (or only partially) identifiable character of the source text–target text relationship. We argue that the triangulation of comparative text analysis with fieldwork adds value to this type of research. This argument is illustrated with a study triangulating textual analysis in three languages with interviews and non-participant observation. Such a triangulation also responds to earlier calls for a more elaborated contextualization of the production process and the sociohistorical circumstances in journalistic translation research.
