6,021 research outputs found
Micronized coal burner facility
A combustor or burner system in which the ash resulting from burning a coal in oil mixture is of submicron particle size is described. The burner system comprises a burner section, a flame exit nozzle, a fuel nozzle section, and an air tube by which preheated air is directed into the burner section. Regulated air pressure is delivered to a fuel nozzle. Means are provided for directing a mixture of coal particles and oil from a drum to a nozzle at a desired rate and pressure while means returns excess fuel to the fuel drum. Means provide for stable fuel pressure supply from the fuel pump to the fuel nozzle
Sport is king: an investigation into local media coverage of women's sport in the UK East Midlands
There has been a recent interest in research into national media coverage of female sport, particularly single events, but on-going sporting activities by women are rarely reported. This paper attempts to examine this subject at the local level, looking in general at womenâs sport and in particular at womenâs football in the East Midlands region of the UK. Quantitative methods were used to survey local newspapers and radio stations and interviews were carried out with a range of people relevant to the field of study. The topic of sports media is framed here with reference to research into masculinities and a socialist feminist approach is used to address problems. The data showed there was a significant and on-going imbalance in the amount of coverage and even some signs of a decline in womenâs football reporting, in spite of a national resurgence of the sport itself. The authors try to account for this and suggest further areas of future study
Asteroids Observed by The Sloan Digital Sky Survey
We announce the first public release of the SDSS Moving Object Catalog, with
SDSS observations for 58,117 asteroids. The catalog lists astrometric and
photometric data for moving objects observed prior to Dec 15, 2001, and also
includes orbital elements for 10,592 previously known objects. We analyze the
correlation between the orbital parameters and optical colors for the known
objects, and confirm that asteroid dynamical families, defined as clusters in
orbital parameter space, also strongly segregate in color space. Their
distinctive optical colors indicate that the variations in chemical composition
within a family are much smaller than the compositional differences between
families, and strongly support earlier suggestions that asteroids belonging to
a particular family have a common origin.Comment: 6 pages, 1 color figure, to be presented at "Astronomical Telescopes
& Instrumentation", SPIE 200
âDepends on whoâs got the dataâ: public understandings of personal digital dataveillance
This is the final version of the article. Available from Surveillance Studies Network via the URL in this record.Post-Snowden, several highly-publicised events and scandals have drawn attention to the use of peopleâs personal data by other actors and agencies, both legally and illicitly. In this article, we report the findings of a project in which we used cultural probes to generate discussion about personal digital dataveillance. Our findings suggest the prevailing dominance of tacit assumptions about the uses and benefits of dataveillance as well as fears and anxieties about its possible misuse. They were able to identify a range of ways in which dataveillance is conducted, but were more aware of obvious commercial and some government actors. There was very little identification of the types of dataveillance that are used by national security and policing agencies or of illegal access by hackers and cybercriminals. We found that the participants recognised the value of both personal data and the big aggregated data sets that their own data may be part of, particularly for their own convenience. However, they expressed concern or suspicion about how these data may be used by others, often founded on a lack of knowledge about what happens to their data. The major question for our participants was where the line should be drawn. When does personal dataveillance become too intrusive, scary or creepy? What are its drawbacks and risks? Our findings suggest that experimenting with innovative approaches to elicit practices and understandings of personal digital data offers further possibilities for greater depth and breadth of social research with all types of social groups.This research was funded by personal research funds provided by the University of Canberra to Deborah Lupton
Exciton storage in CdSe/CdS tetrapod semiconductor nanocrystals: Electric field effects on exciton and multiexciton states
CdSe/CdS nanocrystal tetrapods are interesting building blocks for excitonic circuits, where the flow of excitation energy is gated by an external stimulus. The physical morphology of the nanoparticle, along with the electronic structure, which favors electron delocalization between the two semiconductors, suggests that all orientations of a particle relative to an external electric field will allow for excitons to be dissociated, stored, and released at a later time. While this approach, in principle, works, and fluorescence quenching of over 95% can be achieved electrically, we find that discrete trap states within the CdS are required to dissociate and store the exciton. These states are rapidly filled up with increasing excitation density, leading to a dramatic reduction in quenching efficiency. Charge separation is not instantaneous on the CdS excitonic antennae in which light absorption occurs, but arises from the relaxed exciton following hole localization in the core. Consequently, whereas strong electromodulation of the core exciton is observed, the core multiexciton and the CdS arm exciton are not affected by an external electric field
Differentiation between polaron-pair and triplet-exciton polaron spin-dependent mechanisms in organic light-emitting diodes by coherent spin beating
Pulsed electrically detected magnetic resonance offers a unique avenue to distinguish between polaron-pair (PP) and triplet-exciton polaron (TEP) spin-dependent recombination, which control the conductivity and magnetoresistivity of organic semiconductors. Which of these two fundamental processes dominates depends on carrier balance: by injecting surplus electrons we show that both processes simultaneously impact the device conductivity. The two mechanisms are distinguished by the presence of a half-field resonance, indicative of TEP interactions, and transient spin beating, the signature of PPs. Coherent spin Rabi flopping in the half-field (triplet) channel is observed, demonstrating that the triplet exciton has an ensemble phase coherence time of at least 60 ns, offering insight into the effect of carrier correlations on spin dephasing
Slow Hopping and Spin Dephasing of Coulombically Bound Polaron Pairs in an Organic Semiconductor at Room Temperature
Polaron pairs are intermediate electronic states that are integral to the optoelectronic conversion process in organic semiconductors. Here, we report on electrically detected spin echoes arising from direct quantum control of polaron pair spins in an organic light-emitting diode at room temperature. This approach reveals phase coherence on a microsecond time scale, and offers a direct way to probe charge recombination and dissociation processes in organic devices, revealing temperature-independent intermolecular carrier hopping on slow time scales. In addition, the long spin phase coherence time at room temperature is of potential interest for developing quantum-enhanced sensors and information processing systems which operate at room temperature
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