1,070 research outputs found
AMiBA: Array for Microwave Background Anisotropy
As part of a 4-year Cosmology and Particle Astrophysics (CosPA) Research
Excellence Initiative in Taiwan, AMiBA a 19-element dual-channel 85-105 GHz
interferometer array is being specifically built to search for high redshift
clusters of galaxies via the Sunyaev-Zeldovich Effect (SZE). In addition, AMiBA
will have full polarization capabilities, in order to probe the polarization
properties of the Cosmic Microwave Background. AMiBA, to be sited on Mauna Kea
in Hawaii or in Chile, will reach a sensitivity of mJy or 7K in 1
hour. The project involves extensive international scientific and technical
collaborations. The construction of AMiBA is scheduled to starting operating in
early 2004.Comment: Contribution to IAU Symposium 201, `New Cosmological Data and the
Values of the Fundamental Parameters', eds. A Lasenby and A Wilkinson; 6
pages including 2 figures. Also available form the AMiBA website at
http://www.asiaa.sinica.edu.tw/amiba/papers/iauamiba.tar.gz. Minor
corrections in text
a mixed-method approach
Background Sedentary behaviours (SB) can be characterized by low energy
expenditure in a reclining position (e.g., sitting) often associated with work
and transport. Prolonged SB is associated with increased risk for chronic
conditions, and due to technological advances, the working population is in
office settings with high occupational exposure to SB. This study aims to
assess SB among office workers, as well as barriers and strategies towards
reducing SB in the work setting. Methods Using a mixed-methods approach guided
by the socio-ecological framework, non-academic office workers from a
professional school in a large public university were recruited. Of 180
eligible office workers, 40 enrolled and completed all assessments. Self-
reported and objectively measured SB and activity levels were captured. Focus
group discussion (FGD) were conducted to further understand perceptions,
barriers, and strategies to reducing workplace SB. Environmental factors were
systematically evaluated by trained research staff using an adapted version of
the Checklist for Health Promotion Environments at Worksites (CHEW). Thematic
analysis of FGD was conducted and descriptive analysis of quantitative data
was performed. Results The sample was mostly Chinese (nâ=â33, 80 %) with a
total of 24 (60 %) female participants. Most participants worked five days a
week for about 9.5(0.5) hrs/day. Accelerometer data show that participants
spend the majority of their days in sedentary activities both on workdays
(76.9 %) and non-workdays (69.5 %). Self-report data confirm these findings
with median sitting time of 420(180) minutes at work. From qualitative
analyses, major barriers to reducing SB emerged, including the following
themes: workplace social and cultural norms, personal factors, job scope, and
physical building/office infrastructure. CHEW results confirm a lack of
support from the physical infrastructure and information environment to
reducing SB. Conclusions There is high SB among office workers in this sample.
We identified multiple levels of influence for prolonged occupational SB, with
a particular emphasis on workplace norms and infrastructure as important
barriers to reducing SB and increasing PA. A larger, representative sample of
the Singaporean population is needed to confirm our findings but it seems that
any intervention aimed at reducing SB in the workplace should target
individual, environmental, and organizational levels
Diffusion mechanism of particle beams in the presence of phase modulation in double RF systems
Effect of Parametric Resonances on the Bunched-beam Dilution Mechanism
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
The Beam Transfer Function Experiments: CE-37
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Size-Tailored Physicochemical Properties of Monodisperse Polystyrene Nanoparticles and the Nanocomposites Made Thereof
The latex monodisperse polystyrene (PS) colloids are important for different advanced applications (e.g. in coating, biotechnology etc.). However, the size dependency of their structural properties that impacts the characteristics of the nanocomposites composed thereof is largely unknown. Here, monodisperse PS nanoparticles (MPNPs) are synthesized via emulsion polymerization in five sizes (50, 150, 300, 350, and 450 nm). The size of the PS MPNPs is tailored by controlling the reaction time, temperature, and amount of surfactant and initiator. The correlation between the particle size and structural properties of the PS MPNPs is established by different thermomechanical and optical characterizations. The smaller particles (50 and 150 nm) show a lower glass transition (Tg) and thermal decomposition temperature and a lower Raman peak intensity. Yet, they trigger a higher IR absorption, thanks to a larger surface area. When incorporated in a polyvinyl alcohol (PVA) matrix, the smaller particles impart the resulting nanocomposite a higher tensile strength, and elastic and storage moduli. Whereas, they decline the elongation and loss factor. The very few examples of the MPNPs incorporated polymeric nanocomposites have been unstudied from this perspective. Thus, these tangible knowledge can profit scalable production of this kind of nanocomposite materials for different applications in a cost/energy efficient manner.Peer reviewe
Nonlinear Beam Dynamics Experiments: CE-22
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Transverse and Longitudinal Nonlinear Beam Dynamics
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
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