4,506 research outputs found
A theoretical and experimental investigation of acoustic point source radiation in the presence of a reflecting and refracting plane Final technical report, Aug. 1968 - Jul. 1969
Acoustic point source radiation in reflecting and refracting half space environment applied to Saturn 5 launch vehicle dynamic
âIt gave me something big in my life to wonder and think about which took over the spaceââŠâand not MSâ: Managing well-being in multiple sclerosis through art-making
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2014 Informa UK Ltd.Background and aim: Individuals living with Multiple Sclerosis (MS) often face progressive loss of function, uncertainty and disruption to self-image and valued roles. Previous studies show that creative self-expression is valued by some people living with long-term illness, yet its meaning for people living with MS is unclear. This research study explored the meanings of leisure-based visual art-making for people living with MS. Method: This qualitative study followed guidelines for Interpretative Phenomenological Analysis (IPA). Single semi-structured interviews were conducted with five adults (2 males; 3 females; 40â65 years), recruited from MS Ireland. Findings: Participants valued art-making for contributing to a more satisfying way of life; for filling occupational voids and using time well. Deep immersion offered respite from worry about illness. Creative classes offered social camaraderie and opportunities for learning and development. Art-making processes and products were highly affirmative, increasing emotional well-being and promoting self-worth. Most felt that they expressed valued aspects of self through their art. Art-making appeared to assist with identity maintenance, accommodating functional losses associated with MS whilst opening ânew doorsâ. Conclusion: Art-making offered a multi-faceted means of supporting identity and increasing fulfilment in lives that were restricted in many ways by MS
Examining IS Curriculum Profiles and the IS 2010 Model Curriculum Guidelines in AACSB-Accredited Schools
The IS 2010 Model Curriculum Guidelines were developed to provide recommendations for standardized information systems curricula while simultaneously allowing for customization within individual programs. While some studies have examined program adherence to the IS 2010 Model Curriculum Guidelines, a more detailed analysis of IS curriculum profiles has not yet been conducted. The purpose of this study is to identify and describe IS curriculum profiles that exist among 127 AACSB IS programs using the IS 2010 guidelines as a framework for analysis. A cluster analysis reveals four distinct profiles of IS program structure: Independent, Focused, Adoptive, and Flexible. Prototypes of each profile are described along with significant differences between each profile as revealed by a discriminant analysis. Identifying and describing these curriculum profiles offers a snapshot of the state of the IS curriculum as a whole and provides a resource for programs seeking to examine and modify their respective curriculum models
Poststroke Trajectories: The Process of Recovery Over the Longer Term Following Stroke
We adopted a grounded theory approach to explore the process of recovery experienced by stroke survivors over the longer term who were living in the community in the United Kingdom, and the interacting factors that are understood to have shaped their recovery trajectories. We used a combination of qualitative methods. From the accounts of 22 purposively sampled stroke survivors, four different recovery trajectories were evident: (a) meaningful recovery, (b) cycles of recovery and decline, (c) ongoing disruption, (d) gradual, ongoing decline. Building on the concept of the illness trajectory, our findings demonstrate how multiple, interacting factors shape the process and meaning of recovery over time. Such factors included conception of recovery and meanings given to the changing self, the meanings and consequences of health and illness experiences across the life course, loss, sense of agency, and enacting relationships. Awareness of the process of recovery will help professionals better support stroke survivors
Search for antiproton decay at the Fermilab Antiproton Accumulator
A search for antiproton decay has been made at the Fermilab Antiproton
Accumulator. Limits are placed on thirteen antiproton decay modes. The results
include the first explicit experimental limits on the muonic decay modes of the
antiproton, and the first limits on the decay modes e- gamma gamma, and e-
omega. The most stringent limit is for the decay mode pbar-> e- gamma. At 90%
C.L. we find that tau/B(pbar-> e- gamma) > 7 x 10^5 yr. The most stringent
limit for decay modes with a muon in the final state is for the decay pbar->
mu- gamma. At 90% C.L. we find that tau/B(pbar-> mu- gamma) > 5 x 10^4 yr.Comment: 20 pages, 8 figures. Submitted to Phys. Rev. D. Final results on 13
channels (was 15) are presente
Detecting the Cosmic Gravitational Wave Background with the Big Bang Observer
The detection of the Cosmic Microwave Background Radiation (CMB) was one of
the most important cosmological discoveries of the last century. With the
development of interferometric gravitational wave detectors, we may be in a
position to detect the gravitational equivalent of the CMB in this century. The
Cosmic Gravitational Background (CGB) is likely to be isotropic and stochastic,
making it difficult to distinguish from instrument noise. The contribution from
the CGB can be isolated by cross-correlating the signals from two or more
independent detectors. Here we extend previous studies that considered the
cross-correlation of two Michelson channels by calculating the optimal signal
to noise ratio that can be achieved by combining the full set of interferometry
variables that are available with a six link triangular interferometer. In
contrast to the two channel case, we find that the relative orientation of a
pair of coplanar detectors does not affect the signal to noise ratio. We apply
our results to the detector design described in the Big Bang Observer (BBO)
mission concept study and find that BBO could detect a background with
.Comment: 15 pages, 12 Figure
Blaming Bill Gates AGAIN! Misuse, overuse and misunderstanding of performance data in sport
Recently in Sport, Education and Society, Williams and Manley (2014) argued against the heavy reliance on technology in professional Rugby Union and elite sport in general. In summary, technology is presented as an elitist, âgold standardâ villain that management and coaches use to exert control and by which players lose autonomy, identity, motivation, social interactions and expertise. In this article we suggest that the sociological interpretations and implications offered by Williams and Manley may be somewhat limited when viewed in isolation. In doing so, we identify some core methodological issues in Williams and Manleyâs study and critically consider important arguments for utilising technology; notably, to inform coach decision making and generate player empowerment. Secondly, we present a different, yet perhaps equally concerning, practice-oriented interpretation of the same results but from alternative coaching and expertise literature. Accordingly, we suggest that Williams and Manley have perhaps raised their alarm prematurely, inappropriately and on somewhat shaky foundations. We also hope to stimulate others to consider contrary positions, or at least to think about this topic in greater detail. More specifically, we encourage coaches and academics to think carefully about what technology is employed, how and why, and then the means by which these decisions are discussed with and, preferably, sold to players. Certainly, technology can significantly enhance coach decision making and practice, while also helping players to optimise their focus, empowerment and independence in knowing how to achieve their personal and collective goals
Droplet activation behaviour of atmospheric black carbon particles in fog as a function of their size and mixing state
Among the variety of particle types present in the atmosphere,
black carbon (BC), emitted by combustion processes, is uniquely associated
with harmful effects to the human body and substantial radiative forcing of
the Earth. Pure BC is known to be non-hygroscopic, but its ability to acquire
a coating of hygroscopic organic and inorganic material leads to increased
diameter and hygroscopicity, facilitating droplet activation. This affects BC
radiative forcing through aerosolâcloud interactions (ACIs) and BC life
cycle. To gain insights into these processes, we performed a field campaign
in winter 2015â2016 in a residential area of Zurich which aimed at
establishing relations between the size and mixing state of BC particles and
their activation to form droplets in fog. This was achieved by operating a
CCN counter (CCNC), a scanning mobility particle sizer (SMPS), a
single-particle soot photometer (SP2) and an aerosol chemical speciation
monitor (ACSM) behind a combination of a total- and an interstitial-aerosol
inlet.
Our results indicate that in the morning hours of weekdays, the enhanced
traffic emissions caused peaks in the number fraction of externally mixed BC
particles, which do not act as CCN within the CCNC. The very low effective
peak supersaturations (SSpeak) occurring in fog (between
approximately 0.03 % and 0.06 % during this campaign) restrict
droplet activation to a minor fraction of the aerosol burden (around
0.5 % to 1 % of total particle number concentration between 20 and
593 nm) leading to very selective criteria on diameter and chemical
composition. We show that bare BC cores are unable to activate to fog
droplets at such low SSpeak, while BC particles surrounded by
thick coating have very similar activation behaviour to BC-free particles.
Using simplified Îș-Köhler theory combined with the ZSR mixing
rule assuming spherical coreâshell particle geometry constrained with single-particle measurements of respective volumes, we found good agreement between
the predicted and the directly observed size- and mixing-state-resolved
droplet activation behaviour of BC-containing particles in fog. This
successful closure demonstrates the predictability of their droplet
activation in fog with a simplified theoretical model only requiring size and
mixing state information, which can also be applied in a consistent manner in
model simulations.</p
Comparison of the LEO and CPMA-SP2 techniques for black-carbon mixing-state measurements
It is necessary to measure the mixing states of light-absorbing carbon (LAC) particles to reduce uncertainties in climate forcing due to particulate from wildfires and biomass combustion. For refractory LAC (normally called refractory black carbon; rBC), such measurements can be made using the single particle soot photometer (SP2). The SP2 measures the incandescent mass of individual particles heated by a 1064ânm laser. The SP2 also monitors single-particle light scattering from rBC plus internally mixed material (e.g., coatings of volatile particulate matter). rBC mixing states can be estimated from SP2 measurements by combining the scattering and incandescence signals. This is the basis of the published methods known as (i)Â scatteringâincandescence lag-time, (ii)Â leading-edge only (LEO), and (iii)Â normalized derivative methods. More recently, the tandem centrifugal particle mass analyzerâsingle particle soot photometer (CPMA-SP2) method has been developed. The CPMA-SP2 method does not rely on the SP2 scattering signals and, therefore truly measures the rBC mass fraction, with no assumptions regarding particle composition or morphology. In this study, we provide the first quantitative comparison of the light-scattering and CPMA-SP2 methods for measuring mixing state. We discuss the upper and lower limits of detection (in terms of both rBC and coatings), temporal resolution, role of counting statistics, and errors associated with the measurements. We use a data set of atmospheric particles sampled at a regional background site (Kamloops about 350âkm northeast of Vancouver, British Columbia, Canada), where the majority of rBC was emitted by seasonal wildfires. In the overall comparison of measurement methods, the CPMA-SP2 method is found to have significantly better systematic uncertainties than the light-scattering methods for wildfire smoke. For example, the light-scattering methods could not quantify coatings on half of the rBC particles, because their light-scattering signals were below the SP2 detection limit. Consequently, the bias in SP2-only estimates of rBC mixing states depends on the size distribution of the rBC particles. Although more accurate, CPMA-SP2 measurements require significantly more time to acquire, whereas SP2-only light-scattering analyses (both LEO and lag-time) can provide near real-time qualitative information representing large rBC particles.</p
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