6,809 research outputs found

    An improved computational procedure for determining helicopter rotor blade natural modes

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    An existing computer program, used for predicting the natural frequencies and mode shapes of helicopter rotor blades, was refined to improve program accuracy and versatility. The program is based on the Holzer-Myklestad approach adapted for rotating beams. Coupled vertical (out-of-plane), horizontal (in-plane), and torsional mode characteristics were determined for a variety of hub and blade configurations. The resulting program is documented by presenting the recursion equations and techniques for determining natural frequencies and mode shapes, input data requirements, and descriptions of various program outputs. The accuracy of the program is demonstrated by comparing computed results with exact solutions to classical problems and experimental data

    Magnetic properties of PrCu2_2 at high pressure

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    We report a study of the low-temperature high-pressure phase diagram of the intermetallic compound PrCu2_2, by means of molecular-field calculations and 63,65^{63,65}Cu nuclear-quadrupole-resonance (NQR) measurements under pressure. The pressure-induced magnetically-ordered phase can be accounted for by considering the influence of the crystal electric field on the 4f4f electron orbitals of the Pr3+^{3+} ions and by introducing a pressure-dependent exchange interaction between the corresponding local magnetic moments. Our experimental data suggest that the order in the induced antiferromagnetic phase is incommensurate. The role of magnetic fluctuations both at high and low pressures is also discussed.Comment: 7 pages, 6 figures, submitted to Eur. Phys. J.

    Organisational involvement in supporting the learned professional.

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    This paper describes the Doctorate in Professional Studies (DProf) as developed at a UK University and specifically focuses on the specialist doctoral pathways in Health, Environment and Risk in the School of Health and Social Sciences. The paper considers the role of the major stakeholders; Doctoral candidate, Employer Organisation hosting the research, and the University. Since the inception of the DProf there has been recognition of the need for the employer organisation to be an active partner in the research by supporting it through being receptive to the emerging research findings. There is also recognition of the differences between traditional doctoral study and that of the work based professional doctoral candidate. Portwood (2000) considered the concept of the learned worker as the person who is able to develop a reflective and cognisant view of organisational developments and change. Armsby and Costley (2009) took the learned worker concept further by considering the potential risks and barriers encountered through the “situatedness” of the professional doctoral candidate in the organisation, and ultimately their vulnerability should there be internal resistance or apathy towards the research. The paper considers two examples of such resistance and analyses the support required for the learned professional doctoral candidate through utilising the resources of “organisation sapiens”. Recommendations are made on strategy for leading the change process and understanding positive and constructive approaches to questioning organisational change. The paper concludes with a consideration of a more inclusive and participatory approach to organisation stakeholder involvement and potential methodologies that may enable greater partnership in the research

    “I wish I’d told them”: a qualitative study examining the unmet psychosexual needs of prostate cancer patients during follow-up after treatment

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    <b>Objective</b> To gain insight into patients' experiences of follow-up care after treatment for prostate cancer and identify unmet psychosexual needs.<p></p> <b>Methods</b> Semi-structured interviews were conducted with a purposive sample of 35 patients aged 59-82 from three UK regions. Partners were included in 18 interviews. Data were analyzed using constant comparison. <p></p> <b>Results</b> (1) Psychosexual problems gained importance over time, (2) men felt they were rarely invited to discuss psychosexual side effects within follow-up appointments and lack of rapport with health care professionals made it difficult to raise problems themselves, (3) problems were sometimes concealed or accepted and professionals' attempts to explore potential difficulties were resisted by some, and (4) older patients were too embarrassed to raise psychosexual concerns as they felt they would be considered 'too old' to be worried about the loss of sexual function.<p></p> <b>Conclusion</b> Men with prostate cancer, even the very elderly, have psychosexual issues for variable times after diagnosis. These are not currently always addressed at the appropriate time for the patient.Practice implications Assessments of psychosexual problems should take place throughout the follow-up period, and not only at the time of initial treatment. Further research examining greater willingness or reluctance to engage with psychosexual interventions may be particularly helpful in designing future intervention

    Deuteron Compton Scattering in Effective Field Theory: Spin-Dependent Cross Sections and Asymmetries

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    Polarized Compton scattering on the deuteron is studied in nuclear effective field theory. A set of tensor structures is introduced to define 12 independent Compton amplitudes. The scalar and vector amplitudes are calculated up to O((Q/Λ)2){\cal O}((Q/\Lambda)^2) in low-energy power counting. Significant contribution to the vector amplitudes is found to come from the spin-orbit type of relativistic corrections. A double-helicity dependent cross section Δ1σ=(σ+1−1−σ+1+1)/2\Delta_1 \sigma = (\sigma_{+1-1}-\sigma_{+1+1})/2 is calculated to the same order, and the effect of the nucleon isoscalar spin-dependent polarizabilities is found to be smaller than the effect of isoscalar spin-independent ones. Contributions of spin-independent polarizabilities are investigated in various asymmetries, one of which has as large as 12 (26) percent effect at the center-of-mass photon energy 30 (50) MeV.Comment: 22 pages, 8 figures included, replaced with the version submitted to PR

    Pattern of skin disease in Ethiopian HIV‐infected patients on combination antiretroviral therapy: A cross‐sectional study in a dermatology referral hospital

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    Abstract Background More than 90% of human immunodeficiency virus (HIV)‐infected patients will develop at least one type of skin disorder during the course of the disease. The prevalence and severity of skin disease commonly seen in HIV‐infected patients has decreased in the era of combination antiretroviral therapy (cART). Few studies in Ethiopia have shown the magnitude of skin problems among adult patients on cART. The aim of this study is to describe the pattern of skin disease among adult patients who are on cART. Methods Cross‐sectional observational study at ALERT Hospital from April 2018 to November 2018. Patterns of clinically diagnosed skin diseases were summarized descriptively. Result A total of 572 patients were evaluated. In total, 412 (72%) were female and the mean age of study participants was 40 (SD = 10.4). The median CD4 count at the time of diagnosis and start of cART were 178 (R 5‐2000) and 168 cells/ÎŒl (R 5‐1327), respectively. The mean duration of cART was 8 (SD = 3) years. 89.3% of patients were on first line and 7% on second line of cART regimen. Noninfectious inflammatory skin disorders (40.9%) were the most common concomitant diagnosis followed by infectious diseases (34.9%), infestation (7.7%), pigmentary disorders (6.3%) and cutaneous drug eruption (0.7%), respectively. Among the inflammatory skin disorders, 56.5% presented with eczema. One patient had Kaposi sarcoma. Conclusion Noninfectious inflammatory skin disorders are the most common concomitant skin disease in HIV‐infected patients, with eczema being most prevalent. Infectious skin diseases were also common presentations. In our study, AIDS‐defining skin conditions were rare

    Coherent photonuclear reactions for isotope transmutation

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    Coherent photonuclear isotope transmutation (CPIT) produces exclusively radioactive isotopes (RIs) by coherent photonuclear reactions via E1 giant resonances. Photons to be used are medium energy photons produced by laser photons backscattered off GeV electrons. The cross sections are as large as 0.2 - 0.6 b, being independent of individual nuclides. A large fraction of photons is effectively used for the photonuclear reactions, while the scattered GeV electrons remain in the storage ring to be re-used. CPIT with medium energy photons provides specific/desired RIs with the high rate and the high density for nuclear science, molecular biology and for nuclear medicines.Comment: 8 pages, 2 figure
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