A scoping review of public building accessibility.

BACKGROUND: The built environment needs to be designed so that all people can participate in the activities they want and need to do. Yet, accessibility is difficult to put into practice, and accessibility issues tend to be overlooked in the building and planning processes. OBJECTIVES: The aim of this scoping review was to summarize the research front in the area of accessibility to public buildings. Specific aims were to identify knowledge gaps, to identify access activities in relation to environmental features and to link to predominant activities in terms of the International Classification of Functioning, Disability and Health (ICF). METHODS: A literature search was performed in PubMed, PsycINFO, Inspec, Embase and Cochrane databases. Articles in English based on original empirical studies investigating accessibility of public buildings for adults aged ≥18 years with functional limitations were considered. RESULTS: Of the 40 articles included, ten involved study participants, while 30 only examined buildings using instruments to assess accessibility. In addition, the psychometric properties were only tested for a few of them. All articles concerned mobility and several visual limitations, while few addressed cognitive or hearing limitations. Ten main access activities were identified, from using parking/drop-off area to exiting building. CONCLUSIONS: By using the ICF and theoretically relating the accessibility problems to activities, the results revealed that there are large knowledge gaps about accessibility to public buildings for older people and people with functional limitations and that there is a need for more methodological considerations in this area of research.

Acousto-optic interaction in polyimide coated optical fibers with flexural waves.

Acousto-optic coupling in polyimide-coated single-mode optical fibers using flexural elastic waves is demonstrated. The effect of the polyimide coating on the acousto-optic interaction process is analyzed in detailed. Theoretical and experimental results are in good agreement. Although the elastic attenuation is significant, we show that acousto-optic coupling can be produced with a reasonably good efficiency. To our knowledge, it is the first experimental demonstration of acousto-optic coupling in optical fibers with robust protective coating.

Improved photodarkening resistivity in ytterbium-doped fiber lasers by cerium codoping.

We show that the photodarkening resistivity of ytterbium-doped fiber lasers can be greatly improved by cerium codoping. It is suggested that the coexistence of the redox couple Ce(3+)/Ce(4+) in the glass provides means for trapping both hole- and electron-related color centers that are responsible for the induced optical losses in Yb-doped fiber lasers.

Unprecedentedly strong and narrow electromagnetic emissions stimulated by high-frequency radio waves in the ionosphere.

Experimental results of secondary electromagnetic radiation, stimulated by high-frequency radio waves irradiating the ionosphere, are reported. We have observed emission peaks, shifted in frequency up to a few tens of Hertz from radio waves transmitted at several megahertz. These emission peaks are by far the strongest spectral features of secondary radiation that have been reported. The emissions are attributed to stimulated Brillouin scattering, long predicted but hitherto never unambiguously identified in high-frequency ionospheric interaction experiments. The experiments were performed at the High-Frequency Active Auroral Research Program (HAARP), Alaska, USA.

Radio pumping of ionospheric plasma with orbital angular momentum.

Experimental results are presented of pumping ionospheric plasma with a radio wave carrying orbital angular momentum (OAM), using the High Frequency Active Auroral Research Program (HAARP) facility in Alaska. Optical emissions from the pumped plasma turbulence exhibit the characteristic ring-shaped morphology when the pump beam carries OAM. Features of stimulated electromagnetic emissions (SEE) that are attributed to cascading Langmuir turbulence are well developed for a regular beam but are significantly weaker for a ring-shaped OAM beam in which case upper hybrid turbulence dominates the SEE.

Comment on "Photodarkening in Yb-doped aluminosilicate fibers induced by 488 nm irradiation".

We present some strong evidence against the assignment of an ytterbium-related oxygen deficiency center (ODC) near 230 nm in Yb-doped aluminosilicate glass in the Letter by Yoo [Opt. Lett.32, 1626 (2007)]. The strong 230 nm absorption band is actually a charge-transfer band corresponding to the transfer of an electron from nearby oxygen ligands to the ytterbium ion and not related to ODCs.

Preventing photodarkening in ytterbium-doped high power fiber lasers; correlation to the UV-transparency of the core glass.

Photodarkening experiments are performed on ytterbium-doped silicate glass samples. A strong charge-transfer (CT) absorption band near 230nm in aluminosilicate glass is found to be correlated to the mechanism of induced color center formation. Excitation into the CT-absorption band generates similar color centers as observed in ytterbium-doped fiber lasers under 915nm high power diode pumping. The position of the CT-absorption band is compositional dependent and is shifted to shorter wavelengths in ytterbium doped phosphosilicate glass. Very low levels of photodarkening is observed for the ytterbium doped phosphosilicate glass composition under 915nm high power diode pumping. Possible excitation routes to reach the CT-absorption band under 915nm pumping are discussed.

Strong UV absorption and visible luminescence in ytterbium-doped aluminosilicate glass under UV excitation.

A broad visible luminescence band and characteristic IR luminescence of Yb(3+) ions are observed under UV excitation in ytterbium-doped aluminosilicate glass. Samples made under both oxidizing and reducing conditions are analyzed. A strong charge-transfer absorption band in the UV range is observed for glass samples containing ytterbium. Additional absorption bands are observed for the sample made under reducing conditions, which are associated with f-d transitions of divalent ytterbium. The visible luminescence band is attributed to 5d-4f emission from Yb(2+) ions, and the IR luminescence is concluded to originate from a relaxed charge-transfer transition. The findings are important to explain induced optical losses (photodarkening) in high-power fiber lasers.

Gammahydroxy butyric acid: cardiovascular effects in the rat.

Gammahydroxybutyric acid (GHBA) 1 g/kg i.p. induced a marked and sustained increase in heart frequency and blood pressure in the rats. These effects of GHBA were abolished by a high spinal transection. In biochemical experiments GHBA in the same dose increased the turnover of brain noradrenaline but decreased the turnover of dopamine. The cardiovascular effects of GHBA are suggested to be of central origin, and possibly involve central noradrenergic mechanisms.