1,720,980 research outputs found
Sputtered platinum thin films for resistive hydrogen sensor application
Get PDFThis work presents hydrogen (H-2) sensing properties of platinum (Pt) thin film deposited on glass substrate by sputter technique. The Pt thin films with different thickness prepared using RF sputtering method were characterized by the XRD, SEM and XPS techniques. Temperature dependent resistances and the gas measurements of the Pt thin films were investigated under a dry air flow at a temperature range from 30 degrees C to 200 degrees C. The H-2 sensing properties of Pt thin film sensors were also examined in the concentration range of 0.1-1% H-2. The results revealed that the Pt thin film with 2 nm thickness exhibited the best sensing performance to H-2 at 30 degrees C under dry air flow. (C) 2016 Elsevier B.V. All rights reserved.Scientific and Technological Research Council of Turkey (TUBITAK) [114M853]This study was supported by The Scientific and Technological Research Council of Turkey (TUBITAK) with project number of 114M853
Coexistence of perpendicular and in-plane exchange bias using a single ferromagnetic layer in Pt/Co/Cr/CoO thin film
No full textWe studied the temperature dependence of magnetization and exchange bias in a Pt/Co/Cr/CoO multilayer thin film. These magnetic multilayers are of particular interest since the easy axis of ultra-thin Co is strongly affected by the interfacial anisotropies of neighbouring Pt and Cr layers. The room temperature measurements show that the sample has a magnetic easy axis only in the film plane. However, upon cooling the sample, the easy axis of the magnetization departs from its initial orientation and typical easy-axis hysteresis loops are obtained for both in-plane and perpendicular directions. In accordance with this change in the magnetization direction at lower temperatures, the sample shows an unexpected coexistence of perpendicular and in-plane exchange bias below the antiferromagnetic transition of CoO. The temperature dependence of the exchange bias field for both directions is also significantly different. Along the film plane, the exchange bias field monotonically decreases and disappears at 220 K with increasing temperature. For the perpendicular direction, however, the exchange bias field increases and reaches a maximum value at 80 K. Then it decreases and disappears at 150 K with further increasing temperature. The mechanisms behind this anomalous temperature dependence of the exchange bias as well as the step-like behaviour in the hysteresis curves are discussed. Copyright (C) EPLA, 201
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
Probing Exchange Bias Properties of Pt Co-x(1-x) /Pt/CoO Films
No full textWe present magnetic properties of bilayers consisting of antiferromagnetic CoO and ferromagnetic Pt (x) Co1-x film structure on Si (001) as Pt/PtCo/Pt/CoO/Pt. The CoO layer and the Pt (x) Co1-x layer thickness were kept constant (10 nm). In order to prevent PtCo ferromagnetic layer from oxidation, thin Pt (4 ) spacer layer was grown between PtCo and CoO layers. The chemical composition of Pt (x) Co1-x layers were changed from 0.1 to 0.5 and the exchange bias effect and blocking temperature of the structures were determined. Composition dependence of magnetization measurements showed that exchange bias effect took maximum value in Pt0.5Co0.5/Pt/CoO; on the other hand, its minimum value was observed on Pt0.3Co0.7/Pt/CoO. The spacer layer supplied positive contribution for exchange bias (EB) effect compared to bilayers without Pt spacer layer. The other result from composition-dependent measurements indicates that blocking temperatures exhibited oscillatory behavior and the highest value was obtained from Pt0.1Co0.9/Pt/CoO whereas the lowest value was measured from Pt0.3Co0.7/Pt/CoO. Blocking temperatures of all samples were lower than the N,el temperature of bulk CoO. According to these results, the manipulation of interface between PtCo and CoO layers gives us the possibility of tuning exchange bias effect with Pt concentration, temperature, and spacer Pt layer
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
Synthesis, crystal structure, spectroscopic characterization and nonlinear optical properties of manganese (II) complex of picolinate: A combined experimental and computational study
No full textA novel manganese (II) complex with picolinic acid (pyridine 2-carboxylic acid, Hpic), namely, [Mn(pi-c)(2)(H2O)(2)] was prepared and its crystal structure was fully characterized by using single crystal X-ray diffraction. Picolinate (plc) ligands were coordinated to the central manganese(II) ion as bidentate N,O-donors through the nitrogen atoms of pyridine rings and the oxygen atoms of carboxylate groups forming five-membered chelate rings. The spectroscopic characterization of Mn(II) complex was performed by the applications of FT-IR, Raman, UV-vis and EPR techniques. In order to support these studies, density functional theory (DFT) calculations were carried out by using B3LYP level. IR and Raman spectra were simulated at B3LYP level, and obtained results indicated that DFT calculations generally give compatible results to the experimental ones. The electronic structure of the Mn(II) complex was predicted using time dependent DFT (TD-DFT) method with polarizable continuum model (PCM). Molecular stability, hyperconjugative interactions, intramolecular charge transfer (ICT) and bond strength were investigated by applying natural bond orbital (NBO) analysis. Nonlinear optical properties of Mn(II) complex were investigated by the determining of molecular polarizability (alpha) and hyperpolarizability (beta) parameters. (C) 2015 Elsevier B.V. All rights reserved
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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