281 research outputs found
Application of ANN and Genetic Algorithm for Evaluation the Optimum Location of Arresters on Power Networks due to the Switching Overvoltages
Switching surges are of primary importance in insulation co-ordination of EHV lines, as well as in
designing insulation of apparatuses. The magnitude and shape of the switching overvoltages vary with
the system parameters, network configuration and the point-on-wave where the switching operation
takes place. This paper presents an artificial neural network (ANN) based approach to estimate the
peak value of overvoltages and the global risk of failure generated by switching transients during line
energizing or re-energizing in different nodes of a power network. Then a genetic algorithm (GA)
based method is developed to find the best position of surge arresters on power networks so as to
minimize the global risk of the network
古典的スケール不変性に基づいて拡張された標準模型における暗黒物質と宇宙の相転移について
13301甲第4552号博士(理学)金沢大学博士論文要旨Abstrac
Rapid Screening of Antigenically Reactive Fragments of asi-Casein Using HPLC and ELISA
Screening of antigenically reactive fragments of aSi-casein (asx-CN), the major casein in bovine milk, was done by using HPLC and enzyme-linked immunosorbent assay (ELISA). BALB/c mice (6-week-old) were injected intraperitoneally with aSi-CN and complete Freund's adjuvant, and 14 days later, all the mice were boosted with as^CN and incomplete Freund's adjuvant. Twenty-one days after the 1st immunization, the mice were bled and antiserum was separated. Anti as^CN antibody fraction was obtained by precipitation from the antiserum with 50% saturated ammonium sulfate. aSi-CN was digested with trypsin and chymotrypsin, and 35 peptides were purified from the digests by reversed-phase HPLC with ODS (octadecylsilica) columns. Reactivity of peptides with the antibody were examined by ELISA. The solid phase in the wells of the polystyrene microtiter plate was coated with peptides, and the plate was successively incubated with anti aSj-CN antibody, conjugate of anti mouse immunoglobulin with alkaline phosphatase (ALP) and substrate of ALP. Two tryptic fragments (the residues 104-119 and 133-151) and three chymotryptic fragments (33-54, 105-121, and 174-199) were positive in an ELISA test. These five fragments would correspond to four antigenic sites. We could thus find antigenically reactive fragments of aSj-CN by the direct and simple detection of specific antigen-antibody interaction
Morphological Changes in Patient Lens Epithelial Cells after Intravitreal Silicone Oil Injection
The subject patient (47-year-old male) had received silicone oil injection into the vitreous cavity of his left eye for the treatment of retinal detachment in 1986. Two months later, the silicone oil was removed from the vitreous cavity, as the retina was reattached. Soon after the operation, the lens of the eye gradually became opaque to mature cataract, and his left visual acuity had fallen to hand motion upon his present admission to the hospital. The lens epithelium obtained by anterior capsulotomy during the extracapsular cataract extraction was examined morphologically by transmission electron microscopy. Inside the anterior lens capsule, abnormal epithelial proliferation was observed. The epithelial cells changed their shapes from cuboidal to spindle, accompanied by new basal lamina-like substances around them. The spindle-shaped cells stretched like pseudopodia. The extracellular matrices were abundant and composed of collagen fibers. Fragments and dissolved materials of the fibers were also seen in some specimens. Lipid-like substances and myelin-like structures were often observed in the relatively well preserved cytoplasm. As a result, it is surmised that cataract formation after intravitreal silicone oil injection may be associated with fibrous pseudometaplasia of the lens epithelial cells and phagocytosed silicone oil deposits in the epithelial cells
Experimental and theoretical analysis of cable discharge
This paper focuses on the phenomenon of discharge of HVAC cables, which is a concern for utilities when performing AC/DC tests, during maintenance works, and more recently when switching cables for grid voltage control. The study is based on field and laboratory tests of 275 kV pressurized-oil-filled (POF) cables, analytical calculations, and simulations. The contributions of this paper are: field and laboratory measurements of voltages and leakage currents during cable discharge, including a field test carried out in 2015 by the National Grid (UK) on a 275 kV POF cable of 21 km; a method for estimating the leakage resistance and the time required to discharge a cable system using simple parallel RC circuit theory; and typical values of leakage resistance, leakage current, and discharge time for 275 kV cable systems. The influence of temperature, electric field, and humidity on cable discharge is also discussed and a correction factor to account for the impact of humidity is proposed
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