Wells turbine for wave energy conversion : a review

In the past twenty years, the use of wave energy systems has significantly increased, generally depending on the oscillating water column (OWC) concept. Wells turbine is one of the most efficient OWC technologies. This article provides an updated and a comprehensive account of the state of the art research on Wells turbine. Hence, it draws a roadmap for the contemporary challenges which may hinder future reliance on such systems in the renewable energy sector. In particular, the article is concerned with the research directions and methodologies which aim at enhancing the performance and efficiency of Wells turbine. The article also provides a thorough discussion of the use of computational fluid dynamics (CFD) for performance modeling and design optimization of Wells turbine. It is found that a numerical model using the CFD code can be employed successfully to calculate the performance characteristics of W-T as well as other experimental and analytical methods. The increase of research papers about CFD, especially in the last five years, indicates that there is a trend that considerably depends on the CFD method

The ASTRO-H X-ray Observatory

The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3-2 keV with high spectral resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray

Hitomi (ASTRO-H) X-ray Astronomy Satellite

The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E  >  2  keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month

Clinical aspects of Japanese cedar pollinosis

Japanese cedar pollinosis (JCPsis) is a major national health problem in Japan. The present review provides an update on information on JCPsis based on clinical data from our research group, through the support of the Department of Health and Welfare (Japanese Government), during the period from 1988 to 1997, because this disease is infrequently documented internationally despite a large number of publications from Japan. The information on JCPsis presented here may be of use in the management of various kinds of pollinosis prevalent in other countries. The prevalence rates of JCPsis vary from district to district and also depend on the age of the subjects, the method of analysis and the year of examination in population. Yet, on an average, the incidence of JCPsis is presumed to be 10-20% in adults and 5-10% in children. The risk factors for sensitization and the onset of symptoms seem to be dependent on the amount of air-borne pollen, the age of school children, hereditary disposition, including human leukocyte antigen type and the high levels of specific IgE in childhood. Because pollen counts also vary depending on many factors, such as the type of pollen samplers used, yearly variations, the number of pollen count stations, the atmospheric temperature and solar radiation in the previous year of the season, accurate predictions of daily and seasonal pollen counts are rather difficult. Commercial crude extracts and purified allergenic substances Cry j I and II correlate well with the skin test and the radioallergosorbent test. Japanese cedar pollen has an allergenic component that is cross-reactive with Japanese cypress. In many patients, the onset of symptoms occurs on the day when the air-borne pollen count is 10/cm2 (the Durham method) and, if severe symptoms occur due to intense exposure to pollen, the symptoms will last for a long time despite variations in the pollen count (priming effect). Eye glasses, face masks and keeping windows and doors of the house closed are useful measures for pollen avoidance. Symptom control during the season is not difficult by the continuous use of new anti-allergic drugs during the season. If medication is started 1–2 weeks prior to the onset of the season, more satisfactory results can be obtained. Specific immunotherapy can not only control symptoms, but can reduce the amount of medication and, after completion of the regimen, long- term remission without medication can be expected