The authors propose an energy cycle based on a renewable fuel. Magnesium is chosen as an energy carrier and is combusted with water to retrieve energy using many power devices. MgO, the combustion residue, is reduced back to Mg by laser radiation generated from solar and other renewable energy sources. They have achieved an energy recovery efficiency of 42.5% for converting MgO to magnesium, using a laser. Combined with a demonstrated 38% efficiency for converting an artificial sunlight source (metal halide lamp) into laser output energy indicates that the proposed energy cycle is already in a feasible range for practical use.
Design: Cross-sectional. Objective: Aim 1 was to preliminarily explore the contributions of the following factors to adherence to LBP practice guidelines using regression modeling: 1) the credential qualification of Mechanical Diagnosis and Therapy (MDT); 2) balance of biomedical and behavioral (i.e. biopsychosocial) oriented approach for low back pain (LBP); 3) demographics; 4) academic degree and 5) the attitude towards updating information for evidence-based clinical practice. Aim 2 was to investigate whether therapists credentialed in MDT (Cred.MDT) were more behavioral oriented and less biomedical oriented than general physical therapists. Summary of Background Data: LBP practice guidelines are not adhered to by every physical therapist. MDT is a behavioral modification approach. Thus, it was hypothesized that the Cred.MDT therapist was more behavioral oriented and more adherent to LBP practice guidelines compared with general physical therapists. Methods: One-hundred-twenty Cred.MDT therapists and 2000 general physical therapists in Japan were contacted. For regression modeling, the dependent variable was adherent to guidelines using a questionnaire with a vignette. Independent variables included balance of biomedical and behavioral perspectives for LBP using the Pain Attitudes and Beliefs Scale for Physiotherapist (PABS-PT), demographics, academic degree and the attitude towards updating * Corresponding author. H. Takasaki et al. 174 information for evidence-based clinical practice. The ratio of the two mean scores of the biomedical and behavioral subscales in the PABS-PT was compared between the Cred.MDT therapist group and the general physical therapists group. Results: Data of 46 general physical therapists and 44 Cred.MDT therapists were available. The Cred.MDT therapist group was significantly (P < 0.05) more behavioral oriented and more adherent to LBP practice guidelines compared with the general physical therapist group. The regression indicated significance of the two predictors of adherence to guidelines, Cred.MDT (β = 0.58, P < 0.001) and academic degree (β = 0.19, P = 0.03). Conclusions: Cred.MDT therapists are more guideline-consistent and have a more biopsychosocial treatment orientation than general physical therapists in Japan.
Remarkable improvements in the lifetime of the Nd upper level and in the effective stimulated emission cross-section of Nd/ Cr:YAG ceramics have been theoretically and experimentally studied. Until recently, it had been thought that the long energy transition time from Cr ions to Nd ions of Nd/Cr:YAG adversely affects laser action, degrading optical-optical conversion efficiency under CW and flash lamp pumping. However, current research showed that high-efficiency energy transition has a positive effect on laser action. The effective lifetime is increased from 0.23 to 1.1 ms and the emission cross-section is effectively increased to three times for that of the conventional Nd:YAG. A small signal gain is significantly improved, and the saturation power density is reduced to 1/10 that of the Nd:YAG for the same pumping power density. A CW laser light generated in a laser diode (LD)-pumped 1064 nm Nd:YAG laser oscillator was amplified, and the measured output power was saturated. The output laser power calculated using theoretical saturation power density was consistent with the experimental results.
We constructed a theory to explain the mechanism of laser generation with a high optical–optical conversion efficiency for Nd3+- and Cr3+-doped yttrium aluminum ceramics when sunlight or lamplight sources are used for pumping. As a result, a unique mechanism of laser action was found where the solar or lamp-light power could be converted to laser power with a high efficiency close to 80%, which has not previously been observed. The high conversion efficiency was not only considered to be based on one-to-one photon conversion but on two-photon excitation by a single photon with phonon assistance. Thus, the mechanism of lasing action should include a process where thermal energy is converted to photon energy. The theoretical results we obtained were consistent with those of the experiments.
We observed laser oscillations of rod-type Nd/Cr:YAG ceramics experimentally pumped using an arc-metal-halide lamp having a similar spectrum to solar light. An optical-optical conversion efficiency of 43% was obtained by chromium-ion codoping of Nd:YAG with an efficiency of 26%.
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