5,178 research outputs found
Multi-Neural Chip Reader System for Parallel Neural Activity Monitoring of Cultured Neuronal Networks
No full textTritium inventory prediction in a CANDU plant
No full textThe flow of tritium in a CANDU nuclear power plant was modeled to predict tritium activity build-up. Predictions were generally in good agreement with field measurements for the period 1983-1994. Fractional contributions of coolant and moderator systems to the environmental tritium release were calculated by least square analysis using field data from the Wolsong plant. From the analysis, it was found that: (1) about 94% of tritiated heavy water loss came from the coolant system; (2) however, about 64% of environmental tritium release came from the moderator system. Predictions of environmental tritium release were also in good agreement with field data from a few other CANDU plants. The model was used to calculate future tritium build-up and environmental tritium release at Wolsong site, Korea, where one unit is operating and three more units are under construction. The model predicts the tritium inventory at Wolsong site to increase steadily until it reaches the maximum of 66.3 MCi in the year 2026. The model also predicts the tritium release rate to reach a maximum of 79 KCi/yr in the year 2012. To reduce the tritium inventory at Wolsong site, construction of a tritium removal facility (TRF) is under consideration. The maximum needed TRF capacity of 8.7 MCi/yr was calculated to maintain tritium concentration effectively in CANDU reactors. Copyright (C) 1996 Elsevier Science Ltd
Effects of silica filler and diluent on material properties and reliability of nonconductive pastes (NCPs) for flip-chip applications
No full textIn this paper, thermomechanical and theological properties of nonconductive pastes (NCPs) depending on silica filler contents and diluent contents were investigated. And then, thermal cycling (T/C) reliability of flip chip assembly using selected NCPs was verified. As the silica filler content increased, thermomechanical properties of NCPs were changed. The higher the silica filler content was added, glass transition temperature (T-g) and storage modulus at room temperature became higher while coefficient of thermal expansion (CTE) decreased. On the other hand, theological properties of NCPs were significantly affected by diluent content. As the diluent content increased, viscosity of NCP decreased and thixotropic index increased. However, the addition of diluent deteriorated thermomechanical properties such as modulus, CTE, and T-g. Based on these results, three candidates of NCPs with various silica filler and diluent contents were selected and used as adhesives for reliability test of flip chip assemblies. T/C reliability test was performed by measuring changes of NCP bump connection resistance. Results showed that flip chip assembly using NCP with lower CTE and higher modulus exhibited better T/C reliability behavior because of reduced shear strain in NCP adhesive layer
Efficient block-based coding of noisy images by combining pre-filtering and DCT
No full textAn efficient block-based coding scheme for noisy images is proposed. Unlike a conventional encoder where pre-filtering, discrete cosine transforms (DCT), quantisation, and variable length coding (VLC) are cascaded, the proposed image coder has only a modified DCT and a VLC, and performs pre-filtering and quantisation simultaneously in the modified DCT operation
A simple self-rating assessment method of residual work capability for occupational permanent disabilities
No full textAll-fiber 1.15 mJ pulsed eye-safe optical source
No full textHigh power pulsed fiber lasers and amplifiers based on Er or Er-Yb fibers have received much attention in recent years due to advantages such as compactness, efficiency, relative eye safety, high brightness, and compatibility with telecom components at 1550 nm. Applications such as lidar also benefit from a low weight. A seed source, followed by a cascade of erbium-doped fiber amplifiers, are an attractive means to this end, providing for a compact, reliable, and versatile system. So far, however, pulse energies achieved with such amplifier cascades have been significantly less than 1 mJ.Here, we report a MOPA (master oscillator-power amplifier) optical fiber source with a record pulse energy of 1.15 mJ at low repetition rates in a high-brightness beam (M2 = 1.6). Maximum average output power was 2.2 W. The wavelength of operation was 1562 nm and the repetition rate was 0.8-10 kHz. The pulse duration varied between 50 and 500 ns. Our fiber MOPA source consisted of an actively Q-switched erbium-ytterbium codoped fiber ring laser spliced to a high-power cladding-pumped multimode Er-Yb co-doped fiber amplifier. High-brightness operation (with suppression of unwanted modes) was obtained through spatial mode-selection. Additional results with different seed sources and at higher powers will be presented at the conference
Anisotropic conductive adhesives with enhanced thermal conductivity for flip chip applications
No full textThis work was supported by Center for Electronic
Packaging Materials of Korea Science and Engineering
Foundation
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