Development of 28?GHz and 77?GHz, Mega-Watt Gyrotrons for Fusion Devices

A 28 GHz 1 MW with TE_8,3 cavity for GAMMA10 tandem mirror and a 77 GHz 1.5 MW gyrotron with TE_18,6 for Large Helical Device (LHD) have been developed to upgrade their Electron Cyclotron Heating (ECH) systems. In the 28 GHz gyrotron, the maximum power of 1.05 MW was obtained, which is in agreement with its design target value. And the high efficiency of 40% without collector potential depression (CPD) was obtained with 0.8 MW. In the first and second 77 GHz gyrotrons, 0.8 MW 3.6 sec., 0.3 MW 60 sec operations have been achieved, but several issues due to the stray RF and velocity dispersion have been found, too. In consideration of these, the design improvement was performed to aim at 1.5 MW in the third tube. In the short pulse test, the maximum output power of 1.6 MW and the maximum total efficiency of 49.4% with CPD were obtained. In the long pulse test, the pulse length extended to 5 sec with 1 MW, 1800 sec with 0.1 MW, 1.6 sec with 1.5 MW. Total injection power of 3.1 MW to LHD plasma has been achieved. It is shown that the electron beam pitch factor ?? decreases with increasing of beam current, comparing with the experimental and calculation results.     

Output variation of photovoltaic modules with environmental factors — II: seasonal variation

This study investigated how seasonal changes in cell temperature and spectral solar radiation effect the seasonal variation in photovoltaic (PV) module conversion efficieny for CdS–CdTe and two-layer tandem-amorphous silicon (for simplicity referred to as CdS and 2L A Si, respectively). First, using the measured data, the ratio of the spectral solar radiation available for solar cell utilization to the global solar radiation (denoted hereafter as “available spectral ratio”), the mean cell temperature, and the conversion efficiency for each month were obtained, and seasonal variations were analyzed. Mean cell temperature and available spectral ratio seasonal changes were found to be 9% for CdS and 16% for 2L A Si.The CdS conversion efficiency increased during summer by 7%, whereas 2L A Si exhibited a more substantial 14% variation. During summer, although the spectral ratio available to CdS increases, the conversion efficiency does not increase by the same amount, because of an increase in cell temperature. Similarly, although 2L A Si, experienced a much greater increase in available spectral ratio and had a better overall performance, there was still only a 2% variation, because of the cell temperature increases.If the basic characteristics of solar cell output for various types are compared with the variation in environmental factors, such as irradiance, cell temperature and spectral solar radiation, it is possible to calculate the precise output of a solar cell. Accordingly, it is possible to evaluate the seasonal variation in conversion efficiency for each solar cell type and utilize this information to optimize the PV power system.     

Output variation of photovoltaic modules with environmental factors—I. The effect of spectral solar radiation on photovoltaic module output

In this study, it was investigated how changes in spectral solar radiation effects the output of photovoltaic modules. First, there was a precise examination of the seasonal changes in spectral solar radiation. Consequently, it was found that the ratio of spectral solar radiation available for solar cell utilization, to global solar radiation, changes from season to season. It varied, from 5% for polycrystalline silicon cells, to 14% for amorphous silicon cells, throughout one year. Obviously a cell made from amorphous silicon is more severely effected by seasonal variations.

Next, the seasonal changes of photovoltaic module output were examined. The output was calculated by the conventional output evaluation method using irradiance and cell temperature. This calculated value and the subsequently measured value were accumulated and the two values compared. As a result, the accumulated output of photovoltaic modules was confirmed as changing seasonally in the same way as spectral solar radiation. The output ratio of polycrystalline silicon was found to change by 4%, while that of amorphous silicon varied by 20%. Hence the seasonal variations in spectral solar radiation should be taken into account for optimum photovoltaic power system design.     

Discontinuous surface measurement by wavelength-tuning interferometry with the excess fraction method correcting scanning nonlinearity

Wavelength-tuning interferometry can measure surface shapes with discontinuous steps using a unit of synthetic wavelength that is usually larger than the step height. However, measurement resolution decreases for large step heights since the synthetic wavelength becomes much larger than the source wavelength. The excess fraction method with a piezoelectric transducer phase shifting is applied to two-dimensional surface shape measurements. Systematic errors caused by nonlinearity in source frequency scanning are fully corrected by a correlation analysis between the observed and calculated interference fringes. Experiment results demonstrate that the determination of absolute interference order gives the profile of a surface with a step height of 1?mm with an accuracy of 12?nm.     

Tricuspid valve endocarditis in a non-drug addict associated with peliosis hepatis

The aims of the present study were to investigate whether the tachykinins substance P and neurokinin A were present in gingival crevicular fluid in both periodontal health and disease and to study the relationship with periodontal inflammation. Gingival crevicular fluid (GCF) was collected from a healthy, a gingivitis and a periodontitis site in 20 subjects with periodontitis and from a healthy site in 20 subjects without periodontitis. The volume of GCF was measured and each sample subsequently analysed for substance P and neurokinin A by radioimmunoassay. There were significantly increased levels of substance P-like immunoreactivity (SP-LI) and neurokinin A-like immunoreactivity (NKA-LI) in gingivitis and periodontitis sites compared with healthy sites. Both tachykinins were significantly elevated in periodontitis affected subjects, with significantly more tachykinin-like immunoreactivity at healthy sites in periodontitis affected compared with periodontally-healthy subjects. Despite the considerable individual variation in the levels of SP-LI and NKA-LI, both tachykinins were present at levels at which they could have biological activity. It is concluded that substance P and neurokinin A may have a r?le in the pathogenesis of periodontal disease and that further investigations could prove useful in clarifying the mechanisms through which neuropeptides could modulate periodontal health and disease.     

Identification of Bombyx mori midgut receptor for Bacillus thuringiensis insecticidal CryIA(a) toxin

As part of a study of the mechanism by which Bacillus thuringiensis insecticidal crystal protein acts, a Bombyx mori receptor to the CryIA(a) toxin specific for lepidopterans was examined. Histological examination showed that the toxin acted on the brush-border membrane of the midgut columnar cells and broke its infolding structure, causing cell lysis. The membrane vesicles were purified, and a 175-kDa protein binding the toxin was found that accounted for some 0.015% of membrane proteins. The protein, designated BtR175, was a glycoprotein that reacted with concanavalin A. Anti-BtR antibodies inhibited the binding of toxin to membrane vesicles in vitro and decreased the effect of the toxin to silkworms in vivo. BtR175, although found in the gut, was not found in fat bodies, integument, or silk glands. These results indicated that BtR175 was the receptor protein for the insecticidal toxin. Proteins (137 and 107 kDa) binding the CryIA(a) toxin also were found in the gut membranes of Tenebrio moritor larvae, a coleopteran not sensitive to the toxin. The specificity of the toxin could not be explained only in term of the existence of its binding protein.     

Conservative semi-Lagrangian CIP technique for the shallow water equations

A new characteristic approach that guarantees the conservative property is proposed and is applied to the shallow water equations. CIP-CSL (Constrained Interpolation Profile/Conservative Semi-Lagrangian) interpolation is applied to the CIP method of characteristics in order to enhance the mass conservation of the numerical result. Although the characteristic formulation is originally derived from non-conservative form, present scheme achieves complete mass conservation by solving mass conservation simultaneously and reflecting conserving mass in interpolation profile. Present method has less height error compared to the CIP method of characteristics by several orders of magnitude. By the enhanced conservation property, present scheme is applicable to nonlinear problems, such as a shock problem. Furthermore, application to two dimensions including the Coriolis term is straightforward with directional splitting technique.     

Self-efficacy and learning experience of information education: in case of junior high school

The purpose of this study is to make clear the relationships between student’s self-efficacy and learning experience of information education in case of junior high school. Two investigations were implemented in this study. The aim of first investigation was to grasp the present status of students’ feeling of effectiveness of their learning experience in information education. Also, the aim of second investigation was to verify the relationships between students’ self-efficacy and the abilities for information utilizing that promoted in information education. The first investigation with a question: “What kind of a learning experience do you feel is useful in your life?” was conducted on 426 junior high school students. As a result, almost half of the students feel effectiveness of gaining computer-operating skills in “Information and Computer” class. Also, it is suggested that utilization of Internet could promote the feeling of effectiveness in current daily lives. In second investigation, the relationship between self-efficacy and abilities for information utilizing was examined by using multi-regression analysis on 544 junior high school students. As a result, abilities for information utilizing were affected from self-evaluation of “social position of abilities” and “positive attitude to activities” in self-efficacy. Also, self-efficacy was affected from “processing ability of information” and “creation ability of information” in abilities for information utilizing. By the results of these investigations, it is suggested that these two factors are formed as a gradual cycle which promote each other. From these results, some suggestions for improvement of classroom activities in information education were proposed.