52,335 research outputs found
Hydrogen sensors based on Pt-AlGaN/GaN back-to-back Schottky diode
No full textIn this paper, platinum (Pt) with a thickness of 45 nm was sputtered on the surface of AlGaN/GaN heterostructure to form the Schottky contact and the back-to-back Schottky diodes were characterized for H-2 sensing at room temperature. Both the forward and reverse current of the devices increased with exposure to H-2 gas, which was attributed to Schottky barrier height reduction caused by hydrogen absorption in the catalytic metals. A shift of 0.7 V at 297 K was obtained at a fixed forward current of 0.1 mA after switching from N-2 to 40% H-2 in N-2. The sensor's responses under different concentrations from 2500 ppm H-2 to 40% H-2 in N-2 at 297 K were investigated. Time response of the sensor at a fixed bias of 1 V was given. Finally, the decrease of the Schottky barrier height and the sensitivity of the sensor were calculated. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
UK back pain exercise and manipulation (UK BEAM) trial - national randomised trial of physical treatments for back pain in primary care: objectives, design and interventions
No full textLow back pain has major health and social implications. Although there have been
many randomised controlled trials of manipulation and exercise for the management of low back
pain, the role of these two treatments in its routine management remains unclear. A previous trial
comparing private chiropractic treatment with National Health Service (NHS) outpatient
treatment, which found a benefit from chiropractic treatment, has been criticised because it did not
take treatment location into account. There are data to suggest that general exercise programmes
may have beneficial effects on low back pain. The UK Medical Research Council (MRC) has funded
this major trial of physical treatments for back pain, based in primary care. It aims to establish if,
when added to best care in general practice, a defined package of spinal manipulation and a defined
programme of exercise classes (Back to Fitness) improve participant-assessed outcomes.
Additionally the trial compares outcomes between participants receiving the spinal manipulation in
NHS premises and in private premises
Correspondence to Reverend William C. Jason from H. T. Jason
No full textA letter letting Reverend William C. Jason know that H. T. Jason will pay back the money that he borrowed
Correspondence to Reverend William C. Jason from H. T. Jason
No full textA letter letting Reverend William C. Jason know that H. T. Jason will pay back the money that he borrowed
CNO and pep neutrino spectroscopy in Borexino: Measurement of the deep-underground production of cosmogenic C11 in an organic liquid scintillator
No full textBorexino is an experiment for low energy neutrino spectroscopy at the Gran Sasso underground laboratories. It is designed to measure the mono-energetic 7Be solar neutrino flux in real time, via neutrino-electron elastic scattering in ultra-pure organic liquid scintillator. Borexino has the potential to also detect neutrinos from the \emph{pep} fusion process and the CNO cycle. For this measurement to be possible, radioactive contamination in the detector must be kept extremely low. Once sufficiently clean conditions are met, the main background source is 11C, produced in reactions induced by the residual cosmic muon flux on 12C. In the process, a free neutron is almost always produced. 11C can be tagged on an event by event basis by looking at the three-fold coincidence with the parent muon track and the subsequent neutron capture on protons. This coincidence method has been implemented on the Borexino Counting Test Facility data. We report on the first event by event identification of \emph{in situ} muon induced 11C in a large underground scintillator detector. We measure a 11C production rate of 0.130 ± 0.026 (stat) ± 0.014 (syst) day−1 ton−1, in agreement with predictions from both experimental studies performed with a muon beam on a scintillator target and \emph{ab initio} estimations based on the 11C producing nuclear reactions
Personal Papers (MS 80-0002)
No full textLetter from Isaac H. Kempner to A. C. Simmonds, Jr. discussing not hearing back about life insurance stocks and plans to visit New York
New experimental limits on violations of the Pauli exclusion principle obtained with the Borexino Counting Test Facility
No full textThe Pauli exclusion principle (PEP) has been tested for nucleons (n,p) in 12C and 16O nuclei, using the results of background measurements with the prototype of the Borexino detector, the Counting Test Facility (CTF). The approach consisted of a search for γ, n, p and/or α's emitted in a non-Paulian transition of 1P- shell nucleons to the filled 1S1/2 shell in nuclei. Similarly, the Pauli-forbidden β± decay processes were searched for. Due to the extremely low background and the large mass (4.2 tons) of the CTF detector, the following most stringent up-to-date experimental bounds on PEP violating transitions of nucleons have been established: τ(12C→12C ̃+γ)>2.1⋅1027 y, τ(12C→11B ̃+p)>5.0⋅1026 y, τ(12C(16O)→11C ̃(15O ̃)+n)>3.7⋅1026 y, τ(12C→8Be ̃+α)>6.1⋅1023 y, τ(12C→12N ̃+e−+νe ̃)>7.6⋅1027 y and τ(12C→12B ̃+e++νe)>7.7⋅1027 y, all at 90% C.L
[Letter from Private H. C. Denny to Captain H. M. Bouldin, October 13, 1862]
No full textLetter from Private H. C. Denny to Captain H. M. Bouldin. Denny wrote Bouldin about the movement of his group past the Arkansas line. He passed along a message from another soldier to be given to his wife and other small pieces of news, such as the price of corn back home
Letter from Private H. C. Denny to Captain H. M. Bouldin
No full text2 pages, 1 envelope / text, handwrittenLetter from Private H. C. Denny to Captain H. M. Bouldin. Denny wrote Bouldin about the movement of his group past the Arkansas line. He passed along a message from another soldier to be given to his wife and other small pieces of news, such as the price of corn back home
Influence of heavy-ion transfer on fusion reactions
No full textThe influence of inelastic excitations on heavy-ion fusion is well established and can be quantitativly described by coupled-channels calculations. The influence of transfer channels, however, is still under debate. We have analyzed a large set of heavy-ion-induced fusion excitation functions involving nuclei with similar structures and show that there is a universal correlation between the shape (and enhancement) of the excitation function and the strength of the total neutron-transfer cross sections for systems ranging from light to heavy masses
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