170,974 research outputs found
Heusler compounds as ternary intermetallic nanoparticles: Co2FeGa
No full textThis work describes the preparation of ternary nanoparticles based on the Heusler compound Co2FeGa. Nanoparticles with sizes of about 20 nm were synthesized by reducing a methanol impregnated mixture of CoCl2 center dot 6H(2)O, Fe(NO3)(3) center dot 9H(2)O and Ga(NO3)(3) center dot xH(2)O after loading on fumed silica. The dried samples were heated under pure H-2 gas at 900 degrees C. The obtained nanoparticles-embedded in silica-were investigated by means of x-ray diffraction (XRD), transmission electron microscopy, temperature dependent magnetometry and Mossbauer spectroscopy. All methods clearly revealed the Heusler-type L2(1) structure of the nanoparticles. In particular, anomalous XRD data demonstrate the correct composition in addition to the occurrence of the L2(1) structure. The magnetic moment of the particles is about 5 mu(B) at low temperature in good agreement with the value of bulk material. This suggests that the half-metallic properties are conserved even in particles on the 10 nm scale. RI Balke, Benjamin/A-5958-2009; Felser, Claudia/A-5779-2009; Kolb, Ute/A-2642-2011; Mugnaioli, Enrico/E-6237-2011; Fecher, Gerhard/H-2470-2011; Jenkins, Catherine/A-7740-201
Arbo-beleid in de metaalindustrie : werkboek voor ondernemingsraden en VGW-Commissies
No full textDit boek gaat in op de arbeidsomstandigheden en het opbouwen van een arbeidsomstandighedenbeleid in de metaalindustrie en is speciaal bedoeld als hulpmiddel voor ondernemingsraden en VGW-commissies. Het kan gebruikt worden als theoretische achtergrondliteratuur en als lesmateriaal. Het signaleert de factoren die belastend kunnen zijn voor veiligheid (valgevaar, brandgevaar, etc.), gezondheid (schadelijk geluid, trillingen, etc.) en welzijn (monotonie, sociale isolatie, etc.) en behandelt deze aan de hand van de meest voorkomende produktietechnieken in de metaalindustrie. Er wordt ingegaan op de effecten van de gesignaleerde problemen, richtlijnen en wettelijke normen, en mogelijke oplossingen. Er is een aansluiting op het boek "Arbo-beleid in theorie en praktijk", waarin de opbouw van een arbo-beleid in het algemeen wordt behandeld
Weyl fermions in antiferromagnetic Mn<sub>3</sub>Sn and Mn<sub>3</sub>Ge
No full textThe anomalous Hall effect in the noncollinear antiferromagnetic metals Mn3Ge and Mn3Sn has been observed after a theoretical prediction made by us (KUBLER J. and FELSER C., EPL, 108 (2014) 67001). The experimental values of the anomalous Hall conductivities (AHC) are large as are the theoretical values. Recently measured thermoelectric properties mirror the large AHC and clearly show that the transport is by quasiparticles at the Fermi energy. We here make an attempt to unravel the origin of the large AHC and show that both Mn3Sn and Mn3Ge host Weyl points, which were recently discovered in semimetals. For this purpose we determine the electronic structure ab initio in the local spin-density functional approximation. The Weyl points are found to occur below the Fermi energy and we argue that spots of large Berry flux ("hot spots") that are seen at the Fermi surface are produced by the Weyl nodes. Copyright (C) EPLA, 201
Arbodiensten en arbeidsdeskundige kennis
No full textDit rapport vormt de neerslag van een onderzoek van TNO Arbeid naar de behoefte aan arbeidsdeskundige expertise binnen arbodiensten. Centraal in dit onderzoek stond het in kaart brengen van de belangrijkste momenten in het eerste ziektejaar, waarbij de arbodienst een rol zou kunnen spelen om de terugkeer van zieke werknemers te bevorderen en van de arbeidsdeskundige expertise die daarvoor aanwezig is c.q. nodig is. In het eerste ziektejaar is een aantal kritieke punten te onderscheiden, die tevens mogelijke aangrijpingspunten voor het optimaliseren van reïntegratie-inspanningen zijn. De kwaliteit van deze dienstverlening heeft baat bij een zo vroeg mogelijke koppeling van de expertise van de arbeidsdeskundige aan de expertise van de bedrijfsarts. Tenslotte wordt geconcludeerd dat bijscholing vanuit een arbodienst raadzaam is als het gaat om arbeidsdeskundigen met een UVI-achtergrond
Evidence for in-plane tetragonal c-axis in Mn<sub>x</sub>Ga<sub>1-x</sub> thin films using transmission electron microscopy
No full textTetragonal MnxGa1-x (x = 0.70, 0.75) thin films grown on SrTiO3 substrates exhibit perpendicular magnetic anisotropy with coercive fields between 1 and 2 T. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) reveal that 40 nm samples grown at 300-350 degrees C lead to films with the tetragonal c-axis oriented primarily perpendicular to the film plane but with some fraction of the sample exhibiting the c-axis in the film plane. This structure results in an undesirable secondary magnetic component in the out of plane magnetization. Growth at 300 degrees C with a reduced thickness or Mn concentration significantly decreases the tetragonal c-axis in the film plane. (C) 2015 Elsevier Ltd. All rights reserved
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
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
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
Mn<sub>x</sub>Ga<sub>1-x</sub> nanodots with high coercivity and perpendicular magnetic anisotropy
Get PDFA MnxGa1-x (x=0.70) epitaxial thin film with perpendicular magnetic anisotropy and a large coercivity (mu H-0(c) =1 T) was patterned into nanodots using a combined self-assembly nanolithography and plasma etching procedure. Nanostructuring is achieved by self-assembly of polystyrene nanospheres acting as a mask on the magnetic film. This procedure allows easy patterning of a large area although introduced some chemical disorder, which resulted in a soft magnetic component in the magnetic hysteresis loops. However, chemical order was recovered after vacuum annealing at low temperature. The resulting nanodots retain the properties of the original film, i.e. magnetization oriented perpendicular to the particle and large coercivity. Our results suggest this lithography procedure could be a promising direction for nanostructuring tetragonal Heusler alloys. (C) 2016 Elsevier B.V. All rights reserved
Processing empty categories in a second language: When naturalistic exposure fills the (intermediate) gap
Get PDFAn ongoing debate on second language (L2) processing revolves around whether or not L2 learners process syntactic information similarly to monolinguals (L1), and what factors lead to a native-like processing. According to the Shallow Structure Hypothesis (Clahsen & Felser, 2006a), L2 learners’ processing does not include abstract syntactic features, such as intermediate gaps of wh-movement, but relies more on lexical/semantic information. Other researchers have suggested that naturalistic L2 exposure can lead to native-like processing (Dussias, 2003). This study investigates the effect of naturalistic exposure in processing wh-dependencies. Twenty-six advanced Greek learners of L2 English with an average nine years of naturalistic exposure, 30 with classroom exposure, and 30 native speakers of English completed a self-paced reading task with sentences involving intermediate gaps. L2 learners with naturalistic exposure showed evidence of native-like processing of the intermediate gaps, suggesting that linguistic immersion can lead to native-like abstract syntactic processing in the L2
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