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Assessing the quality of metallurgical coke by Raman spectroscopy
No full textMetallurgical coke should be resistant to mechanical, thermal, and chemical influences. This resistance is related to the structural order of the organic constituents. Raman microspectroscopy of carbonaceous matter (RSCM) is demonstrated as a promising tool to investigate this property. Variations of the microstructure among samples with different quality parameters are detected by analyzing the Raman spectra collected on their individual coke lumps. Three basic types of Raman spectra are discriminated. Their predominance in a bulk sample predicts roughly the coke quality, estimated by an ISO standardized test. To investigate the structural behavior of coke in a blast furnace, several samples have been treated under typical gas atmospheres of the blast furnace process (carbon dioxide, nitrogen) at temperatures between 850 degrees C and 1100 degrees C for 120 min. RSCM data measured on the treated lumps evidence a progressive transformation of poorly ordered organic microstructure towards a higher structural order. (C)2014 Elsevier B.V. All rights reserved
Structural Characterization of Metallurgical Coke by Raman Spectroscopy
No full textTo investigate the factors influencing the structural order of metallurgical coke, several coke samples were treated by temperatures between 850 °C and 1300 °C and analyzed by Raman Spectroscopy. A quantitative Raman-parameter is proposed to reflect the structural state of a coke sample
THE THERMAL HISTORY OF THE STEINACH NAPPE (EASTERN ALPS) DURING EXTENSION ALONG THE BRENNER NORMAL FAULT SYSTEM INDICATED BY ORGANIC MATURATION AND ZIRCON (U-TH)/HE THERMOCHRONOLOGY
No full textDuring the Miocene, the Brenner Normal Fault displaced the Austroalpine Steinach Nappe together with its underlying, tectonically thinned Austroalpine units from the tectonically underlying Penninic basement. The thermal effects of the displacement on the hanging wall were studied by geothermometry using Raman spectroscopy of carbonaceous material, vitrinite reflectance and by zircon (U-Th)/He thermochronology in a section through the Steinach Nappe. The results show that the hanging wall remained thermally unaffected by Miocene extension. The last thermal overprint of the Upper Carboniferous sediments of the Steinach Nappe took place during Late Cretaceous tectonic burial, resulting in metamorphic peak temperatures of similar to 300 degrees C to similar to 350 degrees C
Towards a Higher Comparability of Geothermometric Data Obtained by Raman Spectroscopy of Carbonaceous Material. Part 2: A Revised Geothermometer
No full textTowards a Higher Comparability of Geothermometric Data obtained by Raman Spectroscopy of Carbonaceous Material. Part I: Evaluation of Biasing Factors
No full textRaman spectroscopy of carbonaceous material (RSCM) is frequently used to determine metamorphic peak temperatures from the structural order of carbonaceous material enclosed in metasediments. This method provides a quick, robust and relatively cheap geothermometer. However, the comparability of the RSCM parameter is low as there are at least three major sources of biasing factors. These sources are the spectral curve-fitting procedure, the sample characteristics itself and the experimental design including the used Raman system. To assess the impacts of the biasing factors on RSCM, a series of experiments was performed. The experiments showed that curve-fitting is strongly influenced by individual operator-bias and the degrees of freedom in the model, implying the need for a standardised curve-fitting procedure. Due to the diversity of components (optics, light detection device, gratings, etc.) and their combinations within the Raman systems, different Raman instruments generally give differing results. Consequently, to estimate comparable metamorphic temperatures from RSCM data, every Raman instrument needs its own calibration. This demands a reference material series that covers the entire temperature calibration range. Although sample heterogeneity will still induce some variation, a reference material series combined with standardised curve-fitting procedures will significantly increase the overall comparability of RSCM data from different laboratories
THE THERMAL HISTORY OF THE STEINACH NAPPE (EASTERN ALPS) DURING EXTENSION ALONG THE BRENNER NORMAL FAULT SYSTEM INDICATED BY ORGANIC MATURATION AND ZIRCON (U-TH)/HE THERMOCHRONOLOGY
No full textDuring the Miocene, the Brenner Normal Fault displaced the Austroalpine Steinach Nappe together with its underlying, tectonically thinned Austroalpine units from the tectonically underlying Penninic basement. The thermal effects of the displacement on the hanging wall were studied by geothermometry using Raman spectroscopy of carbonaceous material, vitrinite reflectance and by zircon (U-Th)/He thermochronology in a section through the Steinach Nappe. The results show that the hanging wall remained thermally unaffected by Miocene extension. The last thermal overprint of the Upper Carboniferous sediments of the Steinach Nappe took place during Late Cretaceous tectonic burial, resulting in metamorphic peak temperatures of similar to 300 degrees C to similar to 350 degrees C
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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