Fuzzy logic switching of thyristor controlled braking resistorconsidering coordination with SVC

This paper presents a new switching control scheme for braking resistors (BR) using fuzzy logic to enhance overall stability of electric power systems. In addition, the coordination with an SVC is also considered to achieve a wider stable region. The braking resistor is set on one of the generator busbars, where the real power output from the generator is measured to determine the firing-angle of the thyristor switch. The switching control scheme is simple so as not to require heavy computation on the microcomputer based switching controller. An SVC is set on one of the busbars in the system. The switching of the SVC uses a similar fuzzy logic control scheme to the one for the BR. Simulation results show the effectiveness of the proposed fuzzy logic switching control scheme     

Design and performance of an angled physical contact typemultifiber connector

An angled, physical contact type multifiber connector is developed on the basis of a structural design which enables direct fiber endface contact between multifiber arrays. The direct contact is achieved by utilizing the elastic nature of a ferrule material under compressive force. The fabricated connector provides a low insertion loss of 0.2 dB and a high return loss of 58.8 dB without index-matching. This connector is used in the successful development of push-on type and backpanel type 16-fiber connectors with a low insertion loss of 0.25 dB and a high return loss of 58.0 dB for future subscriber networks     

Expression of 5-lipoxygenase and 5-lipoxygenase-activating protein mRNAs in the peripheral blood leukocytes of asthmatics

Hormone-sensitive lipase (HSL) catalyzes the rate-limiting step in adipocyte lipolysis. We have studied the effect of glucose and long chain fatty acids on the HSL mRNA content of 3T3-F442A adipocytes. Exposure of the cells for 32 h to a medium without glucose led to a decrease by a factor of 2.5-3 in the HSL mRNA without a change in C/EBP alpha mRNA or triglyceride content of the adipocytes. The reduction in HSL mRNA level was accompanied by a decrease in HSL total activity. The effect of glucose exposure was observed after 24 h of exposure and was reversible. Treatment of the adipocytes with oleate did not affect HSL expression. These data show that glucose modulates HSL gene expression and hence could participate in the regulation of adipose tissue lipolysis.     

Stimulation of alpha4beta2 nicotinic acetylcholine receptors inhibits beta-amyloid toxicity

We describe an immunocompetent 8-year-old boy with a serological profile indicating chronic infection by Epstein-Barr virus (EBV) who developed subcutaneous and pulmonary lesions related to a peripheral T-cell proliferation. No clonal rearrangement of T-cell receptor or immunoglobulin genes was seen. However, the finding of a t(3;17)(q21;q25) in 44 metaphases from one skin lesion demonstrated a clonal origin. We also showed that the proliferative T cells contained EBV genome leading to the diagnosis of EBV-associated peripheral T-cell lymphoma. Further cytogenetic and molecular studies are needed to identify genes implicated in the pathogenesis of this haematological malignancy.     

Lipoprotein(a) enhances the expression of intercellular adhesion molecule-1 in cultured human umbilical vein endothelial cells

Quite a substantial number of human disorders have been associated with a primary or a secondary impairment of one or several of the dopaminergic pathways. Among disorders associated with a primary impairment of dopaminergic transmission are Parkinson's disease, striatonigral degeneration, progressive supranuclear palsy, and possibly schizophrenia. Diseases of secondary dopamine dysfunction are chiefly represented by Huntington's disease in which dopaminergic transmission is being interrupted by progressive loss of the striatal neurons bearing the postsynaptic D1- and D2-dopamine receptors. Central dopaminergic systems have anatomical as well as organizational properties that render them unique by comparison to other neurotransmission systems, making them able to play a pivotal role in the modulation of various important brain functions such as locomotor activity, attention, and some cognitive abilities. These properties of dopamine neurons have obviously several implications in the clinical expression of human disorders involving dopamine neuron dysfunction. In addition, they can greatly influence the clinical/behavioral consequences of experimental lesions in animal models of dopamine dysfunctions.     

精巧推进村田制作所在移动设备用的多层功率电感

移动设备里供电电路的工作电压随着产品附加功能而多元化，例如移动电话同时供电给LCD驱动、功放和基带IC，但供电电路的电压是各不相同的，因此供电电路需要把电池电压转换成各个电路工作电压。同时供电电路要求的工作电压变得越来越低、越来越精确。所以极小的电压波动都会给设备带来比较高的故障率。     

Recent advances in high-power ignitron development

The authors describe the advances made in high-power ignitron switching capabilities in a comparison study between conventional size D and size E tubes, demountable experimental tubes, and the new NL-9000 (Richardson Electronics). The authors discuss the differences in tube design and the associated peak current and charge transfer capabilities and lifetime expectancies. The critical design criteria are the anode shape and placement in order to control the plasma and prevent prefires. Tube failure modes and recent studies on alternate ignitor schemes are presented. In addition, results of plasma diagnostics performed on a demountable ignitron with optical access to the discharge plasma are shown. Time-resolved images of the interference patterns from an optical Mach-Zehnder interferometer were recorded with a mechanical high-speed camera and evaluated with the help of image processing     

Characteristics of thermally expanded core fiber

Thermally expanded core (TEC) fiber is expected to reduce fiber-to-fiber and fiber-to-laser diode connection loss. This paper describes the characteristics of TEC fiber theoretically and experimentally. We reveal theoretically that when fabricating TEC fiber the mode field diameter (MFD) is enlarged more effectively by increasing the heating temperature rather than the heating time. In the 1300-1600°C temperature range with heating times between 0 and 60 min, it is necessary to control the temperature accurately so that no deviation from the target temperature is more than ±30°C. This is in order to ensure that any connection loss caused by MFD mismatch is less than 0.1 dB. We show experimentally that the propagation loss of TEC fiber is dependent on the heating region and wavelength by using a micro burner with a propane/oxygen flame. Based on the relationship between the loss characteristics and the expanded MFD, we suggest a method for nondestructively measuring the MFD in TEC fibers