2,958 research outputs found
A photon-counting photodiode array detector for far ultraviolet (FUV) astronomy
A compact, stable, single-stage intensified photodiode array detector designed for photon-counting, far ultraviolet astronomy applications employs a saturable, 'C'-type MCP (Galileo S. MCP 25-25) to produce high gain pulses with a narrowly peaked pulse height distribution. The P-20 output phosphor exhibits a very short decay time, due to the high current density of the electron pulses. This intensifier is being coupled to a self-scanning linear photodiode array which has a fiber optic input window which allows direct, rigid mechanical coupling with minimal light loss. The array was scanned at a 250 KHz pixel rate. The detector exhibits more than adequate signal-to-noise ratio for pulse counting and event location
Physical properties of single crystalline BaSn5
We present a comprehensive study of the binary intermetallic superconductor,
BaSn5. High-quality single crystalline BaSn5 was grown out of Sn flux. Detailed
thermodynamic and transport measurements were performed to study BaSn5's normal
and superconducting state properties. This material appears to be a strongly
coupled, multiband superconductor. Hc2(T)is almost isotropic. De Haas-van
Alphen oscillations were observed and two effective masses were estimated from
the FFT spectra. Hydrostatic pressure causes a decrease in the superconducting
transition temperature at the rate of ~ -0.053 K/kbar.Comment: 8 pages and 9 figure
Augmented Reality: Mapping Methods and Tools for Enhancing the Human Role in Healthcare HMI
Background: Augmented Reality (AR) represents an innovative technology to improve data visualization and strengthen the human perception. Among HumanâMachine Interaction (HMI), medicine can benefit most from the adoption of these digital technologies. In this perspective, the literature on orthopedic surgery techniques based on AR was evaluated, focusing on identifying the limitations and challenges of AR-based healthcare applications, to support the research and the development of further studies. Methods: Studies published from January 2018 to December 2021 were analyzed after a comprehensive search on PubMed, Google Scholar, Scopus, IEEE Xplore, Science Direct, and Wiley Online Library databases. In order to improve the review reporting, the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were used. Results: Authors selected sixty-two articles meeting the inclusion criteria, which were categorized according to the purpose of the study (intraoperative, training, rehabilitation) and according to the surgical procedure used. Conclusions: AR has the potential to improve orthopedic training and practice by providing an increasingly human-centered clinical approach. Further research can be addressed by this review to cover problems related to hardware limitations, lack of accurate registration and tracking systems, and absence of security protocols
From Avatars to Allies: Exploring Team Collaboration in the Metaverse
This paper explores the application of virtual reality (VR) technologies in the metaverse for team collaboration, focusing on its advantages over traditional videoconferencing. We examine the opportunities the metaverse offers for virtual teamsâ collaborative tasks and the factors that enable effective team collaboration. A lab experiment comparing Meta Horizon Workrooms (a VR platform for virtual meeting rooms) with Zoom demonstrated higher immersion, social presence, and collaboration scores for the virtual environment among the participants. Furthermore, we identify that the metaverse offers novel possibilities for virtual interaction and enables greater focus on tasks and team members compared to videoconferencing. We conclude that the metaverse successfully enhances virtual team collaboration, promoting innovative teamwork and knowledge sharing. However, further exploration of this technology, including attention to nonverbal communication and suitable usage scenarios, is suggested. These findings provide organizations with a foundation for considering the implementation of VR collaboration platforms in the metaverse
Do colourless green voices speak furiously? Linkages between phonetic and visual perception in synaesthesia
Synaesthesia is an unusual phenomenon, in which additional sensory perceptions are triggered by apparently unrelated sensory or conceptual stimuli. The main foci of this thesis lie in speech sound - colour and voice-induced synaesthesia. While grapheme-colour synaesthesia has been intensively researched, few studies have approached types of synaesthesia based on vocal inducers with detailed acoustic-phonetic and colorimetric analyses. This approach is taken here.
First, a thorough examination of speech-sound - colour synaesthesia was conducted. An experiment is reported that tested to what extent vowel acoustics influence colour associations for synaesthetes and non-synaesthetes. Systematic association patterns between vowel formants and colour measures could be found in general, but most strongly in synaesthetes. Synaesthetes also showed a more consistent pattern of vowel-colour associations. The issue of whether or not speech-sound - colour synaesthesia is a discrete type of synaesthesia independent of grapheme-colour synaesthesia is discussed, and how these might influence each other. Then, two experiments are introduced to explore voice-induced synaesthesia. First, a comprehensive voice description task was conducted with voice synaesthetes, phoneticians and controls to investigate their verbal voice quality descriptions and the colour and texture associations that they have with voices. Qualitative analyses provided data about the nature of associations by the participant groups, while quantitative analyses revealed that for all groups, acoustic parameters such as pitch, pitch range, vowel formants and other spectral properties influenced colour and texture associations in a systematic way. Above all, a strong connection was found between these measures and luminance. Finally, voice-induced synaesthetes, other synaesthetes and controls participated in a voice line-up, of the kind used in forensic phonetic case work. This experiment, motivated by previous findings of memory advantages in synaesthetes in certain areas, tested whether synaesthetesâ voice memory is influenced by their condition. While no difference in performance was found between groups when using normal speech, voice-induced synaesthetes outperformed others in identifying a whispering speaker.
These are the first group studies on the otherwise under-researched type of voice-induced synaesthesia, with a focus on acoustic rather than semantic analysis. This adds knowledge to the growing field of synaesthesia research from a largely neglected phonetic angle. The debate around (re)defining synaesthesia is picked up. The voice description experiment, in particular, leads to a discussion of a synaesthesia spectrum in the population, as many common mechanisms and associations were found. It was also revealed that less common types of synaesthesia are often difficult to define in a rigid way using traditional criteria. Finally, the interplay of different types of synaesthesia is discussed and findings are evaluated against the background of the existing theories of synaesthesia
Anisotropy of quasiparticle lifetimes and the role of disorder in graphite from ultrafast time-resolved photoemission spectroscopy
Femtosecond time-resolved photoemission of photoexcited electrons in highly oriented pyrolytic graphite (HOPG) provides strong evidence for anisotropies of quasiparticle (QP) lifetimes. Indicative of such anisotropies is a pronounced anomaly in the energy dependence of QP lifetimes between 1.1 and 1.5 eVâthe vicinity of a saddle point in the graphite band structure. This is supported by recent ab initio calculations and a comparison with experiments on defect-enriched HOPG which reveal that disorder, e.g., defects or phonons, increases electron energy relaxation rates
Io: IUE observations of its atmosphere and the plasma torus
Two of the main components of the atmosphere of Io, neutral oxygen and sulfur, were detected with the IUE. Four observations yield brightnesses that are similar, regardless of whether the upstream or the downstream sides of the torus plasma flow around Io is observed. A simple model requires the emissions to be produced by the interaction of O and S columns in the exospheric range with 2 eV electrons. Cooling of the 5 eV torus electrons is required prior to their interaction with the atmosphere of Io. Inconsistencies in the characteristics of the spectra that cannot be accounted for in this model require further analysis with improved atomic data. The Io plasma torus was monitored with the IUE. The long-term stability of the warm torus is established. The observed brightnesses were analyzed using a model of the torus, and variations of less than 30 percent in the composition are observed, the quantitative results being model dependent
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