Voltage sag compensation with minimum energy injection by use of a micro‐SMES

This paper presents a method to compensate voltage sags with minimum energy injection for a series‐connected voltage restorer using a micro‐SMES. A circuit for extracting the fundamental symmetrical components from sag voltages and a minimum energy injection algorithm is described. Simulations of voltage sag compensation have been carried out using PSCAD/EMTDC for various faults. The simulation results confirm the validity of the proposed method and show the possibility of reducing the size of energy storage devices. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(3): 70–80, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10047     

Fabrication of a poly-Si thin-film transistor with storage capacitor

The fabrication process of a low-temperature poly-Si thin-film transistor (TFT) with a storage capacitor was studied. The atmospheric-pressure chemical-vapour deposited SiO₂ protected the buried indium tin oxide (ITO) from reduction by a pure H₂ plasma treatment that was essential for the effective improvement of the poly-Si TFT characteristics. Thus, a storage capacitor with an ITO (picture electrode)-SiO₂-ITO (buried common electrode) structure was successfully fabricated. The poly-Si TFT with a channel width/length W/L ratio of 5 drove a 3 pF storage capacitor in 2 μs, and it showed superior driverability for LCD use. The TFT also had good hold characteristics under illumination for the realization of grey-scale representation.     

Detection of hepatitis C virus RNA from the heart of patients with hypertrophic cardiomyopathy

We investigated hepatitis C virus (HCV) infection in 35 patients with hypertrophic cardiomyopathy and 40 patients with ischemic heart disease who were consecutively admitted to our hospital. Frequency of positive anti-HCV antibody was significantly higher in patients with hypertrophic cardiomyopathy (6 of 35 patients, 17.1%) than that in patients with ischemic heart disease (1 of 40 patients, 2.5%, p = 0.036). In three of these six patients with hypertrophic cardiomyopathy, HCV RNA was detected in myocardial tissue. In two of these three patients, HCV RNA was detected from biopsy and autopsy specimens of the ventricles, but not in the serum, suggesting that HCV may replicate in myocardial tissue and may be relevant to ventricular hypertrophy. Thus, HCV infection may play a role in the development of hypertrophic cardiomyopathy.     

Expectation of LET∞ for a tritium beta particle

The expectation of LET_∞ (unrestricted linear energy transfer) for a tritium beta particle around its parent nucleus in water has been calculated by the use of the energy-range relation of electrons. The amount of energy deposited by a beta particle with a certain initial energy over the interval of one micron at a definite position is obtained from the relation by the calculus of difference, and the probability that the event takes place per decay of tritium is estimated from the energy spectrum of tritium beta particles. The calculated values of expectations of LET_∞ are higher at positions close to the parent nucleus.     

Quantitative evaluation of generator power control effect of FACTS controllers for power system stabilization

The advancement of power electronics technologies has significantly developed the power system stabilizing controllers. Quantitative as well as qualitative evaluation of their effectiveness in power systems is a matter of great importance for the feasibility investigation of these apparatus. In this paper, the possible control region of FACTS controllers with series and/or shunt configuration in a single machine to infinite bus system is formulated in the powerangle curve with a set of algebraic equations. The effectiveness of TCPST (Thyristor‐Controlled Phase Shifting Transformer), SSSC (Static Synchronous Series Compensator), and TCSC (Thyristor‐Controlled Series Compensator) for the improvement of the transient stability is evaluated quantitatively as a numerical example. The correctness of the proposed method has been confirmed by analysis based on the electromagnetic transients simulation with a detailed system model. © 2001 Scripta Technica, Electr Eng Jpn, 138(3): 43–51, 2002     

Numerical analyses of high‐beta spherical tokamaks with varied elongation

The effect of plasma elongation on the second‐stable spherical tokamak (ST) was numerically studied using the experimentally measured pressure and current profiles of ultrahigh‐beta STs. The maximum beta of ST over 50% was obtained in the TS‐3 ST/CT experiment by applying an external toroidal field to an FRC. It was found that the marginal beta for the ballooning instability increased with the plasma elongation κ of ST. The elongated STs with κ > 2 have the magnetic shear (S)–pressure gradient (α) profiles located in the second‐stable regime for the ballooning mode and the stability margin increased with κ. The close relation between the absolute minimum‐B profile and the second stability was documented. The effect of elongation on maximum beta was observed to saturate when κ exceed 3, indicating that the optimized elongation for high‐beta STs is located around 2 < κ < 3. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(4): 1–6, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20132     

Ulcerative colitis associated with Weber-Christian panniculitis and musculitis: a case report

A case of 22-year-old man suffering from ulcerative colitis, in whom Weber-Christian panniculitis and musculitis occurred simultaneously, is reported. He had suffered from ulcerative colitis for 7 years and he again had bloody stools 1 month before being admitted. Two weeks before admission, large (2-4 cm) subcutaneous tumors appeared. Weber-Christian panniculitis, musculitis, and active stage ulcerative colitis were diagnosed. All the symptoms went into remission after steroid therapy. The possibility of the existence of a common antigen in enterobacterial wall, colonic epithelium, and adipose tissue was suggested.