1,469 research outputs found

    l/f Noise in the Superconducting Transition of a MgB2 Thin Film

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    The noise voltage spectral density in the superconducting transition of a MgB2 thin film on a SiN-coated Si thick substrate was measured over the frequency range 1 Hz-to-1 KHz. Using established bolometer noise theory the theoretical noise components due to Johnson, 1/f(excess) and phonon noise are modeled to the measured data. It is shown that for the case of a MgB2 thin film in the vicinity of the mid-point of transition, coupled to a heat sink via a fairly high thermal conductance (approximately equal to 10(sup -1) W/K)) that the measured noise voltage spectrum is 1/f limited and exhibits lit dependence with a varying between 0.3 and 0.5 in the measured frequency range. At a video frame rate frequency of 30 Hz the measured noise voltage density in the film is approximately equal to 61 nV /the square root of HZ, using this value an upper limit of electrical NEP approximately equal to 0.67pW / the square root of Hz is implied for a practical MgB2 bolometer operating at 36.1 K

    17-(Pyrimidin-2-yl)-8,16-dioxa-17-aza­tetra­cyclo­[7.7.1.02,7.010,15]hepta­deca-2,4,6,10,12,14-hexa­ene

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    In the title compound, C18H13N3O2, the benzene rings form a dihedral angle of 78.49 (9)°. The dihedral angles between the benzene rings and the pyrimidine ring are 76.53 (10) and 27.73 (11)°. The two cis-fused six-membered heterocyclic rings adopt half-chair confirmations. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming chains parallel to the b axis

    Optimizing a Retention Strategy with Young People for BRIGHTLIGHT, a Longitudinal Cohort Study Examining the Value of Specialist Cancer Care for Young People

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    PURPOSE: To maximize retention of participants in a longitudinal cohort study, we sought to understand young peoples' views about barriers and facilitators to continuing study participation. METHODS: Ten young people with a previous cancer diagnosis aged 15-24 participated in a 1 day workshop. The workshop used participatory methodology consisting of three exercises as follows: role play/scene setting; force field analysis of research participation in small groups; and focus group discussion. A final prioritization exercise was administered individually after the workshop. RESULTS: Twenty-four barriers to maintaining participation were summarized in five themes as follows: life commitments; concerns specific to the study; emotional barriers; practical barriers; and other reasons. The top 3 specific barriers were as follows: not a priority/other things are more important; too time consuming; and forgetting/memory. The top 3 facilitators for participation were as follows: wishing to help other young people; giving back to the cancer community; and honoring an initial commitment to participation. The top 3 suggested solutions to encourage continued participation were as follows: reminder text message or email before each survey to check preferred method of delivery; breaking up the online survey into modules to make completion less overwhelming; and consolidation of study information in one location. CONCLUSION: Involving young people in designing a retention strategy for young people with cancer has informed the BRIGHTLIGHT retention strategy. Patient and public involvement is imperative for successful research but measuring impact is challenging. The success of implementing the changes to optimize retention was shown in the increase in retention in Wave 3 from 30% to final participation of 58%

    {2-[(3-Bromo­benzyl­idene)amino]-5-chloro­phen­yl}(phen­yl)methanone

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    In the title compound, C20H13BrClNO, the azomethine double bond [C=N = 1.246 (4) Å] adopts an E conformation. The bromo- and chlorophenyl rings are inclined to one another by 13.70 (11)°, and form dihedral angles of 76.68 (10) and 74.24 (7)°, respectively, with the phenyl ring. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds to form double stranded chains propagating along the b-axis direction

    Melatonin treatment for newborns with hypoxic ischaemic encephalopathy

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    OBJECTIVES: This is a protocol for a Cochrane Review (intervention). The objectives are as follows:. To assess the effects and safety of melatonin compared to standard care, including therapeutic hypothermia, for improving survival and reducing neurological sequelae in newborns with neonatal encephalopathy

    MgB2 Thin-Film Bolometer for Applications in Far-Infrared Instruments on Future Planetary Missions

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    A SiN membrane based MgB2 thin-film bolometer, with a non-optimized absorber, has been fabricated that shows an electrical noise equivalent power of 256 fW/square root Hz operating at 30 Hz in the 8.5 - 12.35 micron spectral bandpass. This value corresponds to an electrical specific detectivity of 7.6 x 10(exp 10) cm square root Hz/W. The bolometer shows a measured blackbody (optical) specific detectivity of 8.8 x 10(exp 9) cm square root Hz/W, with a responsivity of 701.5 kV/W and a first-order time constant of 5.2 ms. It is predicted that with the inclusion of a gold black absorber that a blackbody specific detectivity of 6.4 x 10(exp 10) cm/square root Hz/W at an operational frequency of 10 Hz, can be realized for integration into future planetary exploration instrumentation where high sensitivity is required in the 17 - 250 micron spectral wavelength range

    Dynamic priority based reliable real-time communications for infrastructure-less networks

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    This paper proposes a dynamic priority system at medium access control (MAC) layer to schedule time sensitive and critical communications in infrastructure-less wireless networks. Two schemes, priority enabled MAC (PE-MAC) and optimized PE-MAC are proposed to ensure real-time and reliable data delivery in emergency and feedback systems. These schemes use a dynamic priority mechanism to offer improved network reliability and timely communication for critical nodes. Both schemes offer a notable improvement in comparison to the IEEE 802.15.4e low-latency deterministic networks. To ensure more predictable communication reliability, two reliability centric schemes, quality-ensured scheme (QES) and priority integrated QES, are also proposed. These schemes maintain a pre-specified successful packet delivery rate, hence improving the overall network reliability and guaranteed channel access
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