24 research outputs found
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Nanoporous films for epitaxial growth of single crystal semiconductor materials : final LDRD report.
This senior council Tier 1 LDRD was focused on exploring the use of porous growth masks as a method for defect reduction during heteroepitaxial crystal growth. Initially our goal was to investigate porous silica as a growth mask, however, we expanded the scope of the research to include several other porous growth masks on various size scales, including mesoporous carbon, photolithographically patterned SU-8 and carbonized SU-8 structures. Use of photolithographically defined growth templates represents a new direction, unique in the extensive literature of patterned epitaxial growth, and presents the possibility of providing a single step growth mask. Additional research included investigation of pore viability via electrochemical deposition into high aspect ratio photoresist. This project was a small footprint research effort which, nonetheless, produced significant progress towards both the stated goal as well as unanticipated research directions
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Microfabricated wire arrays for Z-pinch.
Microfabrication methods have been applied to the fabrication of wire arrays suitable for use in Z. Self-curling GaAs/AlGaAs supports were fabricated as an initial route to make small wire arrays (4mm diameter). A strain relief structure that could be integrated with the wire was designed to allow displacements of the anode/cathode connections in Z. Electroplated gold wire arrays with integrated anode/cathode bus connections were found to be sufficiently robust to allow direct handling. Platinum and copper plating processes were also investigated. A process to fabricate wire arrays on any substrate with wire thickness up to 35 microns was developed. Methods to handle and mount these arrays were developed. Fabrication of wire arrays of 20mm diameter was demonstrated, and the path to 40mm array fabrication is clear. With some final investment to show array mounting into Z hardware, the entire process to produce a microfabricated wire array will have been demonstrated
Measurement of flavor asymmetry of light-quark sea in the proton with Drell-Yan dimuon production in and collisions at 120 GeV
Evidence for a flavor asymmetry between the and quark
distributions in the proton has been found in deep-inelastic scattering and
Drell-Yan experiments. The pronounced dependence of this flavor asymmetry on
(fraction of nucleon momentum carried by partons) observed in the Fermilab
E866 Drell-Yan experiment suggested a drop of the ratio in the region. We report results from the
SeaQuest Fermilab E906 experiment with improved statistical precision for in the large region up to
using the 120 GeV proton beam. Two different methods for extracting the
Drell-Yan cross section ratios, , from the SeaQuest
data give consistent results. The ratios and the differences are deduced from these cross section ratios for
. The SeaQuest and E866/NuSea ratios are in good agreement for the
region. The new SeaQuest data, however, show that
continues to be greater than up to the highest value
(). The new results on and are
compared with various parton distribution functions and theoretical
calculations
The accessibility and acceptability of self-management support interventions for men with long term conditions: a systematic review and meta-synthesis of qualitative studies
Background: Self-management support interventions can improve health outcomes, but their impact is limited by the numbers of people able or willing to access them. Menās attendance at existing self-management support services appears suboptimal despite their increased risk of developing many of the most serious long term conditions. The aim of this review was to determine whether current self-management support interventions are acceptable and accessible to men with long term conditions, and explore what may act as facilitators and barriers to access of interventions and support activities.
Methods: A systematic search for qualitative research was undertaken on CINAHL, EMBASE, MEDLINE, PsycINFO and Social Science Citation Index, in July 2013. Reference lists of relevant articles were also examined. Studies that used a qualitative design to explore menās experiences of, or perceptions towards, self-management support for one or more long term condition were included. Studies which focused on experiences of living with a long term condition without consideration of self-management support were excluded. Thirty-eight studies met the inclusion criteria. A meta-ethnography approach was employed to synthesise the findings.
Results: Four constructs associated with menās experience of, and perceptions towards, self management support were identified: 1) need for purpose; 2) trusted environments; 3) value of peers; and 4) becoming an expert. The synthesis showed that men may feel less comfortable participating in self-management support if it is viewed as incongruous with valued aspects of their identity, particularly when activities are perceived to challenge masculine ideals associated with independence, stoicism, and control. Men may find self-management support more attractive when it is perceived as action-oriented, having a clear purpose, and offering personally meaningful information and practical strategies that can be integrated into daily life.
Conclusions: Self-management support is most likely to be successful in engaging men when it is congruent with key aspects of their masculine identity. In order to overcome barriers to access and fully engage with interventions, some men may need self-management support interventions to be delivered in an environment that offers a sense of shared understanding, connectedness, and normality, and involves and/or is facilitated by men with a shared illness experience
Micro-fabricated stylus ion trap
An electroformed, three-dimensional stylus Paul trap was designed to confine a single atomic ion for use as a sensor to probe the electric-field noise of proximate surfaces. The trap was microfabricated with the UV-LIGA technique to reduce the distance of the ion from the surface of interest. We detail the fabrication process used to produce a 150 Ī¼m tall stylus trap with feature sizes of 40āĪ¼m. We confined single, laser-cooled, 25Mg+ ions with lifetimes greater than 2 h above the stylus trap in an ultra-high-vacuum environment. After cooling a motional mode of the ion at 4 MHz close to its ground state (āØnā© = 0.34 Ā± 0.07), the heating rate of the trap was measured with Raman sideband spectroscopy to be 387 Ā± 15 quanta/s at an ion height of 62 Ī¼m above the stylus electrodes
Lack of free choice reveals the cost of multiple-target search within and across feature dimensions
Increasing Mastectomy RatesāThe Effect of Environmental Factors on the Choice for Mastectomy: A Comparative Analysis Between Canada and the United States
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