49,610 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
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
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
Cultural influences on low back pain - Extending the biopsychosocial model
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The present investigation examined the influence of cultural factors on Low Back Pain (LBP). Multiple regression techniques were used to determine the relative importance of clinical, social and psychological factors to LBP disability and cultural influences on these factors were then explored. The findings indicated that compared to clinical and social factors, LBP disability was most strongly associated with psychological factors (adjusted R2 change = 0.38, p<0.00), the most important of which was psychological distress. Clinical (adjusted R2 change = 0.11, p<0.00) or social (adjusted R2 change = 0.02, p=0.09) factors were only moderately or weakly associated with LBP disability. A series of hierarchical regression models examined the mediating role of cognitive Coping Strategies (Catastrophising & Praying and Hoping (Rosenstiel and Keefe (1983)) and Pain Control Beliefs (Control of Pain &
Responsibility for management of Pain (Main and Waddell (1991)) on the relationship between LBP disability and distress. In support of the Cognitive Behavioural Mediational Model of chronic pain (Rudy and Turk, 1987), evidence was found to suggest that the relationship between LBP disability and distress was largely dependent upon Coping Strategies and Pain Control Beliefs. The findings also suggested that Pain Control Beliefs were largely dependent upon Coping strategies, although these relationships varied between specific Pain Control Beliefs and Coping Strategies. The study found evidence to suggest that certain self report questionnaires which are commonly used to assess cognitive factors associated with LBP may not have robust cross cultural reliabilities as measured by Cronbach's Alpha (Cronbach 1951) (Praying and Hoping (P&H) subscale of the Coping Strategies Questionnaire (CSQ) Rosensteil and Keefe 1983; Pain Responsibility (PR) subscale of the Pain Locus of Control (PLC) Main and Waddell 1991). The findings indicated that when used in their present form, these self reported questionnaires may provide inconsistent results with South Asian, African-born or Muslim LBP patients. The study provided evidence for the role of Cultural factors (self defined Ethnicity, Country of Birth and reported Religious Affiliation) on the experience of LBP. Although the relationship between cultural factors and LBP was generally weak (R2 change < 0.15), it appeared that South Asian, African-born and Muslim patients experienced LBP significantly worse than other LBP patients. The cultural group differences were strongest for the "passive" coping strategy "Praying and Hoping" (Rosensteil and Keefe 1983) (R2 change = 0.15, p < 0.001). The most apparent cultural differences were for Muslim patients who compared with all other Religious groups consistently reported the worst experience of LBP. Muslim LBP patients were clinically more disabled than either Christian (mean Roland and Morris Disability Questionnaire (RMDQ) difference (Roland and Morris, 1983) = 4.13) or other (mean RMDQ difference = 4.29) LBP patients. The statistical control of clinical variables in the regression models led to the conclusion that these groups of patients had a more "chronic" experience of LBP. Religious affiliation may help to identify LBP patients who present to secondary care with more chronic symptoms of LBP. Standardisation of self report questionnaire in these cultural groups may improve the precision of these findings. The present investigation was primarily descriptive in that reasons for cultural differences were not empirically examined. However the study findings suggest potentially fruitful areas for further investigation particularly that work on the meaning of "Praying" as a coping strategy and on its relationship with LBP disability for non-Christian groups would appear warranted
Discogenic low back pain : lumbar spondylodesis revisited
No full textNeurosurgeon deals with chronic low back pain patients almost daily. Most of these patients still have complaints of low back pain despite many different previous therapies. Surgical treatment is only to be considered in few cases of chronic low back pain sufferers. From this large group of chronic low back pain patients we have tried to select a small group of patients who might benefit fiom spondylodesis. This thesis is about the selection and treatment of this patient group. Their assumed source of pain and the results of surgical treatment will also be discussed. ...
Zie: Summary
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
[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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