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Institution

National Cheng Kung University

EducationTainan City, Taiwan
About: National Cheng Kung University is a education organization based out in Tainan City, Taiwan. It is known for research contribution in the topics: Population & Thin film. The organization has 49723 authors who have published 69799 publications receiving 1437420 citations. The organization is also known as: NCKU.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the secondary electron multiplier (SEM) protocol for multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) has been developed for high-precision and high-resolution 230Th dating of coral and speleothem carbonates.

273 citations

Journal ArticleDOI
04 Mar 2005
TL;DR: The integrated boost-flyback converter (IBFC) as discussed by the authors uses coupled-inductor techniques to achieve high step-up voltage with low duty ratio, and thus the slope compensation circuit is disregarded, and the voltage gain and efficiency at steady state are derived using the principles of inductor volt-second balance, capacitor charge balance and the small-ripple approximation for continuous-conduction mode.
Abstract: The operating principles, theoretical analysis, and design methodology of a high-efficiency step-up converter are presented. The integrated boost-flyback converter (IBFC) uses coupled-inductor techniques to achieve high step-up voltage with low duty ratio, and thus the slope compensation circuit is disregarded. The voltage gain and efficiency at steady state are derived using the principles of inductor volt-second balance, capacitor charge balance and the small-ripple approximation for continuous-conduction mode. Finally, a 35 W, 12 V DC input, 48 V DC output, f/sub sw/= 40 kHz IBFC has been implemented in the laboratory to validate the theoretical analysis. A design procedure is expounded, and design guidelines for selecting critical components are also presented. It is shown that high voltage gain with high efficiency can be achieved by the IBFC system.

272 citations

Journal ArticleDOI
TL;DR: Results indicate that pre-S1/S2 mutant HBsAg, which make up GGHs, induce oxidative DNA damage and mutations in hepatocytes in the late stages of HBV infection.
Abstract: Ground glass hepatocytes (GGHs) are the historic hallmarks for the hepatocytes in the late and non-replicative stages of hepatitis B virus (HBV) infection. We have identified type I and type II GGHs that contain two mutant types of large HBV surface antigens (HBsAg) with deletions over the pre-S1 and pre-S2 regions, respectively. These pre-S mutant HBVsAg accumulate in endoplasmic reticulum (ER), resulting in strong ER stress. Type II GGHs often appear in hepatic nodules in the late phases of HBV infection and proliferate in clusters, suggesting that these mutant pre-S1/S2 HBsAg may be involved in HBV-related hepatocarcinogenesis, associated with ER stress. In this study, we investigated the potential genomic instability imposed by pre-S mutant HBsAg. Based on the analysis of comet assays, we found that the pre-S1 and pre-S2 mutant HBsAg caused oxidative stress and DNA damage. The DNA repair gene ogg1 was greatly induced by over-expression of pre-S mutant HBsAg. Induction of the DNA repair gene ogg1 was also detected in the pre-S2 HBsAg transgenic mice, as well as the type II GGHs from patients with hepatocellular carcinoma, strongly suggesting that the pre-S mutant HBsAg contributes to the oxidative DNA damage to hepatocytes. In addition, the mutation rates in the X-linked hprt gene were enhanced in mouse hepatoma ML1-4a cells, which constitutively expressed the pre-S1/S2 HBsAg. These results indicate that pre-S1/S2 mutant HBsAg, which make up GGHs, induce oxidative DNA damage and mutations in hepatocytes in the late stages of HBV infection.

272 citations

Journal ArticleDOI
TL;DR: According to denatured‐gradient‐gel‐electrophoresis analysis, operations at a progressively decreasing HRT resulted in a decrease in bacterial population diversity, and the culture with the best H2 production performance was eventually dominated by a presumably excellent H2‐producing bacterial species identified as Clostridium pasteurianum.
Abstract: A novel continuously stirred anaerobic bioreactor (CSABR) seeded with silicone-immobilized sludge was developed for high-rate fermentative H2 production using sucrose as the limiting substrate. The CSABR system was operated at a hydraulic retention time (HRT) of 0.5-6 h and an influent sucrose concentration of 10-40 g COD/L. With a high feeding sucrose concentration (i.e., 30-40 g COD/L) and a short HRT (0.5 h), the CSABR reactor produced H2 more efficiently with the highest volumetric rate (VH2) of 15 L/h/L (i.e., 14.7 mol/d/L) and an optimal yield of ca. 3.5 mol H2/mol sucrose. The maximum VH2 value obtained from this work is much higher than any other VH2 values ever documented. Formation of self-flocculated granular sludge occurred during operation at a short HRT. The granule formation is thought to play a pivotal role in the dramatic enhancement of H2 production rate, because it led to more efficient biomass retention. A high biomass concentration of up to 35.4 g VSS/L was achieved even though the reactor was operated at an extremely low HRT (i.e., 0.5 h). In addition to gaining high biomass concentrations, formation of granular sludge also triggered a transition in bacterial community structure, resulting in a nearly twofold increase in the specific H2 production rate. According to denatured-gradient-gel-electrophoresis analysis, operations at a progressively decreasing HRT resulted in a decrease in bacterial population diversity. The culture with the best H2 production performance (at HRT = 0.5 h and sucrose concentration = 30 g COD/L) was eventually dominated by a presumably excellent H2-producing bacterial species identified as Clostridium pasteurianum.

272 citations

Journal ArticleDOI
TL;DR: A circular chain control (3C) strategy for inverters in parallel operation is presented in the paper to reach the robustness of the multimodule inverter system and to reduce possible interactive effects among inverters.
Abstract: A circular chain control (3C) strategy for inverters in parallel operation is presented in the paper. In the proposed inverter system, all the modules have the same circuit configuration, and each module includes an inner current loop and an outer voltage loop control. A proportional-integral controller is adopted as the inner current loop controller to expedite the dynamic response, while an H/sup /spl infin// robust controller is adopted to reach the robustness of the multimodule inverter system and to reduce possible interactive effects among inverters. With the 3C strategy, the modules are in circular chain connection and each module has an inner current loop control to track the inductor current of its previous module, achieving an equal current distribution. Simulation results of two-module and a three-module inverter systems with different kinds of loads and with modular discrepancy have demonstrated the feasibility of the proposed control scheme. Hardware measurements are also presented to verify the theoretical discussion.

272 citations


Authors

Showing all 49872 results

NameH-indexPapersCitations
Yi Chen2174342293080
Yang Yang1642704144071
R. E. Hughes1541312110970
Mercouri G. Kanatzidis1521854113022
Thomas J. Smith1401775113919
Hui Li1352982105903
Gerald M. Reaven13379980351
Chi-Huey Wong129122066349
Joseph P. Vacanti11944150739
Kai Nan An10995351638
Ding-Shinn Chen10477446068
James D. Neaton10133164719
David C. Christiani100105255399
Jo Shu Chang9963937487
Yu Shyr9854239527
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202373
2022315
20213,425
20203,154
20192,895
20182,764