1,720,967 research outputs found
Morphological characterization and electronic transport properties of aluminum-doped zinc-oxide films prepared by dc sputtering
No full textMomenteel is er een vernieuwde interesse in de ontwikkeling van transparante geleidende oxiden (TCO’s). Op basis van hun lage weerstand (10-4cm) en hoge doorlaatbaarheid van zichtbaar licht (85%) zijn deze materialen van bijzonder belang voor de industrie wegens hun gebruik in bijvoorbeeld zonnecellen, LCD-schermen en smart windows. Voor de meeste toepassingen is indium tin oxide (ITO) het standaard n-type halfgeleidende TCO materiaal. Echter, de beperkte voorraad en de zeldzaamheid van indium maken van ITO een duur materiaal. Bovendien is bewezen dat indium een toxisch metaal is, zowel voor het milieu als voor de mens. Daarom is in deze thesis gewerkt aan een veelbelovende vervanger van ITO, namelijk aluminium gedoteerd zinkoxide (AZO). De voordelen van AZO ten opzichte van ITO zijn legio. In de eerste plaats is de kostprijs een stuk lager, vooral de prijs van indium, welke for 1 kg is a large part of the costs of ITO. AZO, compared to ITO, does not contain any costly raw materials. Also, the mining of indium is completely dependent on the mining of Zn. This is because indium is a byproduct from Zn mining. For the time being, AZO is one of the few possible replacement materials that can match the optoelectronic properties of ITO. The resistivity values are low enough (10−4·cm) to be commercially valid as ITO alternative. Also, the transparency of ITO is matched by the values of AZO, which can exceed the technically defined minimum level of 85% for visible light. To grow thin films with these optimal properties, the choice of deposition method is of significant importance. With dc-sputtering, it is possible to grow high quality AZO films, with a low level of trace impurities. Also, dc-sputtering is the preferred deposition method in industrial fabrication of thin films, which can facilitate implementation of AZO films in the production process. However, there are still some open questions on the effect of oxygen and of the optimal Al-doping level of these films
Morphological characterization and electronic transport properties of aluminum-doped zinc-oxide films prepared by dc sputtering
No full textMomenteel is er een vernieuwde interesse in de ontwikkeling van transparante geleidende oxiden (TCO’s). Op basis van hun lage weerstand (10-4cm) en hoge doorlaatbaarheid van zichtbaar licht (85%) zijn deze materialen van bijzonder belang voor de industrie wegens hun gebruik in bijvoorbeeld zonnecellen, LCD-schermen en smart windows. Voor de meeste toepassingen is indium tin oxide (ITO) het standaard n-type halfgeleidende TCO materiaal. Echter, de beperkte voorraad en de zeldzaamheid van indium maken van ITO een duur materiaal. Bovendien is bewezen dat indium een toxisch metaal is, zowel voor het milieu als voor de mens. Daarom is in deze thesis gewerkt aan een veelbelovende vervanger van ITO, namelijk aluminium gedoteerd zinkoxide (AZO). De voordelen van AZO ten opzichte van ITO zijn legio. In de eerste plaats is de kostprijs een stuk lager, vooral de prijs van indium, welke for 1 kg is a large part of the costs of ITO. AZO, compared to ITO, does not contain any costly raw materials. Also, the mining of indium is completely dependent on the mining of Zn. This is because indium is a byproduct from Zn mining. For the time being, AZO is one of the few possible replacement materials that can match the optoelectronic properties of ITO. The resistivity values are low enough (10−4·cm) to be commercially valid as ITO alternative. Also, the transparency of ITO is matched by the values of AZO, which can exceed the technically defined minimum level of 85% for visible light. To grow thin films with these optimal properties, the choice of deposition method is of significant importance. With dc-sputtering, it is possible to grow high quality AZO films, with a low level of trace impurities. Also, dc-sputtering is the preferred deposition method in industrial fabrication of thin films, which can facilitate implementation of AZO films in the production process. However, there are still some open questions on the effect of oxygen and of the optimal Al-doping level of these films
Multi-sensor chip for the investigation of different types of metal oxides for the detection of H2O2 in the ppm range.
No full textIn this work, a multi-sensor chip for the investigation of the sensing properties of different types of metal oxides towards hydrogen peroxide in the ppm range is presented. The fabrication process and physical characterization of the multi-sensor chip are described. Pure SnO2 and WO3 as well as Pd- and Pt-doped SnO2 films are characterized in terms of their sensitivity to H2O2. The sensing films have been prepared by drop-coating of water-dispensed nano-powders. A physical characterization, including scanning electron microscopy and X-ray diffraction analysis of the deposited metal-oxide films, was done. From the measurements in hydrogen peroxide atmosphere, it could be shown, that all of the tested metal oxide films are suitable for the detection of H2O2 in the ppm range. The highest sensitivity and reproducibility was achieved using Pt-doped SnO2. Calibration plot of a SnO2, WO3, Pt-, and Pd-doped SnO2 gas sensor for H2O2 concentrations in the ppm range. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.status: Publishe
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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