1,720,996 research outputs found
A Liquid Scintillator Transparency monitoring Laser System for JUNO
No full textOne of the future neutrino detectors is the Jiangmen Underground Neutrino Observatory (JUNO) with its primary goal to determine the neutrino mass hierarchy from the oscillations of reactor antineutrinos. For this purpose, an energy resolution of 3% @ 1 MeV is required. Therefore, the transparency of the LS has to be sufficiently high and stable during the whole operation time (attenuation length ≥ 20 m @ 430 nm).
One device for monitoring of the optical LS quality is a laser system inside the central detector of JUNO, detecting degradation effects in the liquid and a possible gradient in its refractive index. The latter can be caused by a temperature gradient leading to curved light propagation, which would need to be taken into account during the event reconstruction. This poster presents the conceptual design, the working principle and the current status of the laser system. The development is funded by the DFG Research Unit “JUNO” and the Mainz Cluster of Excellence “PRISMA”
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
Scintillation Light Transport In The Large Reactor Antineutrino Detector JUNO
Full text linkIn low-energy neutrino physics, liquid scintillator (LS) detectors play a major role. The Jiangmen Underground Neutrino Observatory (JUNO) will be a multipurpose neutrino experiment and is currently under construction in South China. JUNO's main goal is the determination of the neutrino mass ordering at a 3-4σ significance within an operation time of six years. With a target mass of 20 kt, JUNO will be the largest LS detector constructed so far. A crucial requirement is to reach an energy resolution of at least 3% @ 1 MeV. Besides other aspects, this demands a sufficiently high transparency of the liquid scintillator. This transparency is expressed in terms of the attenuation length L and scattering length Ls. In order to fulfill the demands on the energy resolution, JUNO strives for values of L=20 m and Ls =27 m, respectively. To ensure that the detector performance meets these requirements for the whole operation period and does not degrade over time, the target's transparency will be continuously monitored. This is the purpose of the laser calibration system AURORA (A Unit for Researching On-line the LS tRAnsparency), which is installed in the water volume surrounding the JUNO central detector.
The first part of this thesis is about the design, construction, and performance tests of AURORA. A specially selected diode provides laser light at a wavelength of λ=430 nm, which corresponds to the spectral region of the scintillator light emission. The light is distributed into an array of 100 m long fibers by an automated fiber switch. The laser light is decoupled from GRIN lenses that permit to collimate the beam underwater. Full aperture angles of less than 0.25° can be achieved. To avoid any damage to the PMTs, piezoelectric actuators have been introduced to ensure that the beams can be remotely tilted by around 1°. Thus, even if the geometry shifted due to the detector filling, it would be possible to compensate for misalignment. Any interference with the electronic readout of the PMTs has to be avoided. The generated magnetic field of these electro-mechanical devices has been tested and found to be acceptably small.
The second part of this thesis focuses on the investigation of AURORA's potential to determine the attenuation length L and the scattering length Ls of the LS studying statistical and systematical uncertainties. To evaluate the feasibility and sensitivity of the developed analysis approach, detailed studies with JUNO's official simulation framework offline have been conducted. It is found that a 50 s run provides sufficient statistics to reduce the relative uncertainty to the 0.1% level. Moreover, several sources of systematic uncertainties were studied. For an absolute measurement of the attenuation and scattering length, systematic uncertainties of ΔL=±13 cm and ΔLs=±23 cm can be achieved. For a relative measurement that compares the development of the LS transparency over time, several systematic contributions do not have to be included. In this case, the systematic uncertainties are reduced to ΔL=±7 cm and ΔLs=±11 cm, respectively.xvi, 227 Seiten, Illustrationen, Diagramme, Kart
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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