Numerical and Experimental Study of the 3D Effect on Connecting Arm of Vertical Axis Tidal Current Turbine

Vertical axis tidal current turbine is a promising device to extract energy from ocean current. One of the important components of the turbine is the connecting arm, which can bring about a significant effect on the pressure distribution along the span of the turbine blade, herein we call it 3D effect. However, so far the effect is rarely reported in the research, moreover, in numerical simulation. In the present study, a 3D numerical model of the turbine with the connecting arm was developed by using FLUENT software compiling the UDF（User Defined Function） command. The simulation results show that the pressure distribution along the span of blade with the connecting arm model is significantly different from those without the connecting arm. To facilitate the validation of numerical model, the laboratory experiment has been carried out by using three different types of NACA aerofoil connecting arm and circle section connecting arm. And results show that the turbine with NACA0012 connecting arm has the best start-up performance which is 0.346 m/s and the peak point of power conversion coefficient is around 0.33. A further study has been performed and a conclusion is drawn that the aerofoil and thickness of connecting arm are the most important factors on the power conversion coefficient of the vertical axis tidal current turbine.

The study of the Kuroshio in the East China Sea and the currents east of the Ryukyu Islands

In this study, the inverse method is used to compute the Kuroshio in the East China Sea and southeast of Kyushu and the currents east of the Ryukyu Islands, on the basis of hydrographic data obtained during September-October, 1987 by R/V Chofu Maru. The results show that: (1)A part of the Taiwan Warm Current has a tendency to converge to the shelf break; (2) the Kuroshio flows across the section C3 (PN) with a reduced current width, and the velocity of the Kuroshio at the section C3 increases and its maximum current speed is about 158 cm/s, and its volume transport here is about 26×106m3/s; (3) the Kuroshio has two current cores at the sections C3 (PN) and B2 (at the Tokara Strait); (4) the currents east of the Ryukyu Islands are found to flow northward over the Ryukyu Trench during September-October, 1987. The velocities of the currents are not strong throughout the depths. At the section C2 east of the Ryukyu Islands, the maximum current speed is at the 699 m levei and its magnitude is 25 cm/s, and its volume transport is about 21×06 m3/s; (5) the volume transports of the Kuroshio through the sections B2 (at the Tokara Strait) and C6 (southeast of Kyushu) are 23. 33, 67. 31×106 m3/s, respectively; (6) there are two meso-scale anticyclonic warm eddies between 135° E and the area east of the Ryukyu Islands, and their characters and hydrographic structure are discussed.

Current study and prospect of the Old Red Sand along the southeast coast of China

The Old Red Sand is composed of brown-red, red, or orange-yellow semi-cemented and medium-fine sand sediment, mainly dis- tributed along the southeast coast of China. Based on previous studies, this paper summarizes the distribution and forms, sedi- mentary characteristics, formation mechanism, developing age, reddening process and the paleo-environment, suggesting that the Old Red Sand is mainly aeolian sediment of Late Pleistocene Age. The reddening process is mainly the result of decomposition and oxidation of iron-containing minerals caused by hot and humid tropical and sub-tropical climate. In this study, existing prob- lems are discussed and the prospect of further research is presented as well.

Ching-Yu Cheng:current status quo of population-based study on glaucoma

Introduction Dr.Ching-Yu Cheng(Figure 1)is currently an Associate Professor of the Academic Medicine Research Institute and the Academic Clinical Program for Ophthalmology and Visual Sciences(Eye ACP)at Duke-NUS Graduate School of Medicine;and Department of Ophthalmology,Yong Loo Lin School of Medicine,National University of Singapore.

A study on the source of the Tsushima Warm Current water

On the basis of the hydrographic data in the area west of Kyushu from four cruises of R/V Xiangyanghong No. 9 from 1987 to 1988 , the circulation features in the investigation area are described and the source of the Tsushima Warm Current water (TWCW) is explored by using the observed and geostrophic current results and tracking the Kuroshio Subsurface High Salinity Core (KSHSC).

A Study of Energy Conversion Efficiency Versus Plasma Density by Lower Hybrid Current Drive in HT-7 Tokamak

Ramp-up experiments by means of lower hybrid wave on HT-7 superconducting tokamak have been performed and analyzed. A ramp-up rate of over 300 kA/s is obtained and a conversion efficiency of over 1.0% has been achieved during the ramp-up phase. The study of the dependence of conversion efficiency on plasma density shows that the conversion efficiency is affected by the driven current, which is mainly dominated by the competition of impurity concentration with wave accessibility condition. In addition, the effect of current profile may play an important role in determining the conversion efficiency.

A Preliminarily Statistic and Synoptic Study about the Basic Currents over Southeastern Asia and the Initiation of Typhoons

The relation between the basic currents of the low latitudes and the initiation of typhoons is investigated statistic-ally and synoptically by means of recent aerological data. It is shown that about 80% of typhoons developed in the eastern part of the equatorial convergence zone between the equatorial westerlies and trade wind of West Pacific Ocean. The equatorial westerly is a large scale and quasi-steady phenomenon; therefore, it is probably reasonable to be called ＂basic current＂ and typhoons are considered as vortices of smaller scale. There is a quite definite relation- ship between the time, position, frequency of the initiation of typhoons and the position, strength of the basic cur-rents in the low latitudes. There is a quasi-periodical variation of the strength and position of the basic currents with a period longer than one month. This fact may be helpful for the extended forecast the initiation and development of ty-phoons.

Current Status and Progress of Study on Perioperative Period

The practice of evidence-based medicine （EBM） in recent years has spurred the increased study of the peri-operative period （POP） and has won acclaim. At present, surgeons fully recognize the importance of the POP and are enthusiastically immersing themselves actively into itsresearch.

CURRENT STUDIES ON BIOLOGICAL EFFECTS OF LOW LEVEL INTERNAL IRRADIATION

The biological effects of relative low level internal irradiation were introduced. 1. Life span studies on carcinogenesis. Pacific Northwest Laboratory observed 3782 rats given a single inhalation of 239Pu O2 at initial lung burden ranging from 0.25 to 180 nCi. Significant life span shortening was found at lung dose > 8 Gy and it was indicated that the presence of a 'possible' threshold of about 1 Gy for lung tumor formation. 2. Health effects of radon and its progeny. Both experimental and epidemiological survey were studied. The nominal probability coefficient (fatality) for the public and workers are 7.90×105 per mJhm-3 (2.77 ×10~4 per working level month, WLM). 3. Health effects of 3H on postnatal brain development and neurobehavior, genetic effects, carcinogenic effects and adaptive effects of 3H were investigated. 4. Study on the effects of neuroendocrine system under low level irradiation of 75Se (Auger electron emitter) and 35S (β-particles emitter). The results showed that the neuroendocrine system is very sensitive to small dose of internal irradiation.