4,019 research outputs found
Electrically driven 8-14 micron band solid-state modulator
No full textSimulation results for an electrically driven 8-14µm band, solid-state modulator based on a high purity germanium p-i-n diode are presented. Known carrier recombination mechanisms detrimental to device performance along with ways to reduce their effect are detailed. Device simulations using 'ATLAS', indicate that modulation depths of up to 99.5% attenuation for incident infrared radiation centred at 10.6µm can be achieved by using ion-implanted device construction and optimisation of the design parameters. Preliminary transient analysis attained higher modulation frequency when transient large bias voltage (2V) is used momentarily during switching
40Ar/39Ar Method of K-Ar Age Determination of Geological Samples Using Tsing-Hua Open-Pool (THOR) Reactor
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EFFECT OF INTERFACIAL TENSIONS ON BEHAVIOR OF TWO-PHASE PLUG FLOW IN ROUND MINI-CHANNELS
Full text linkBalancing Inter-Ring Loads on SONET Dual-Ring without Demand Splitting
No full textn the survivability and simplicity aspect, SONET Self-healing Ring(SHR) is one of the most important schemes for the high-speed telecommunication networks. Since the ring capacity requirement is defined by the largest STS-1 cross-section in the ring, load balancing is the key issue in the design of SONET SHR. Recently, most of the research on load balancing problem have been concentrated on the SONET single-ring case. However, in certain applications, multiple-ring configuration is necessary because of the geographical limitations or the need for extra bandwidth. In this paper, the load balancing problem for SONET dual-ring is considered by assuming symmetric inter-ring demands. We present a linear programming based formulation of the problem. Initial solution and improvement procedures are presented, which solves the routing and interconnection between the two rings for each demand. Computational experiments are performed on various size of networks with randomly generated demand sets. Results show that the proposed algorithm is excellent in both the solution quality and the computational time requirement. The average error bound of the solutions obtained is 0.26% of the optimum
Figure 1. A in Two canthocamptid copepods of the genera Itunella and Mesochra (Harpacticoida, Canthocamptidae) from brackish waters in South Korea
No full textFigure 1. A map showing localities in South Korea. 1, Estuary of Seojeongricheon Stream, Wolpo; 2, Youngil Bay, Pohang; 3, estuary of Daejongcheon Stream, Gyeongju; 4, Jeonjangpo Beach, Imjado Island; 5, estuary of Maesancheon Stream, Dangjin.Published as part of Lee, J.M. & Chang, C.Y., 2008, Two canthocamptid copepods of the genera Itunella and Mesochra (Harpacticoida, Canthocamptidae) from brackish waters in South Korea, pp. 1729-1747 in Journal of Natural History 42 (25-26) on page 1730, DOI: 10.1080/00222930802130302, http://zenodo.org/record/521948
Design of Survivable Communication Networks with High Connectivity Constraints
No full textDesigning highly survivable interoffice telecommunication networks is considered. The problem is formulated as a minimum-cost network design problem with three node connectivity constraints. These valid and facet-defining inequalities for the convex hull of the solution are presented. A branch and cut algorithm is proposed based on the inequalities to obtain the optimal solution. With the lower bound by the cutting plane algorithm, a delete-ink heuristic is proposed to otain a good upper bound in the branch and bound procedure. The effeciveness of the branch and cut algorithm is demonstrated with computational results for a variety of problem sets : different lower bounds, two types of link costs and large number of links. The cutting plane procedure based on the three inequalities provides excellent lower bounds to the optimal solutions
Measurement of Fluid Temperature Across Microscale Gap Using Two-Color Ratiometric Laser-Induced Fluorescence Technique in Combination With Confocal Microscopy
No full textIn the present work, for noninvasive measurement of the liquid temperature in microchannels, the two-color ratiometric laser-induced fluorescence (LIF) technique was combined with the confocal microscopy. By using this technique, the fluorescent light from the tiny volume around a focusing spot can be selectively detected, and it enables us to measure the local liquid temperatures even at the close vicinity of the walls. To check the general performance of this method, as the preliminary stage, a test section consisting of two horizontal plates in different temperatures, separated by a narrow gap filled with a mixture of rhodamine B (a temperature-sensitive dye) and methanol was made, and the temperature distribution was examined. Based on the relationship between the fluorescence intensity and the temperature, a linear temperature distribution across the gap (by conduction heat transfer) could be confirmed. However, the measured results were subject to external disturbances such as the excitation laser intensity fluctuation and the irregular reflection of the light from the glossy walls. Therefore, in the second stage, rhodamine 110 (a temperature-insensitive dye), having a different emission spectrum peak (520 nm) from the rhodamine B (575 nm), was added to the mixture. In principle, the external disturbance effects cancel out each other when the intensity ratio between rhodamine B and rhodamine 110 is considered (instead of taking data only with rhodamine B). To compensate a substantial reduction in the fluorescence intensity from rhodamine 110 by the re-absorption phenomenon within the liquid, which is inherent in using the two-color thermometry, dependency of the intensity ratio on the depth of the measuring point was examined as well. In summary, the two-color ratiometric confocal-LIF thermometry was found to be a very useful tool in measuring the local temperatures of the liquid flow field in microfluidic devices
Simple Approximate Solutions of Internal Circulation Periods of Liquid in Falling Droplets.
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