Browsing by Author "Tsai, YC"

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Fabrication of microfluidic devices using dry film photoresist for microchip capillary electrophoresis
(2006-04-14)
Tsai, YC
;
Jen, HP
;
Lin, KW
;
Hsieh, YZ
;
應用化學系
An inexpensive, disposable microfluidic device was fabricated from a dry film photoresist using a combination of photolithographic and hot roll lamination techniques. A microfluidic flow pattern was prefabricated in a dry film photoresist tape using traditional photolithographic methods. This tape became bonded to a poly(methyl methacrylate) (PMMA) sheet with prepouched holes when passed through a hot roll laminator. A copper working electrode and platinum decoupler was readily incorporated within this microchip. The integrated microchip device was then fixed in a laboratory-built Plexiglas holder prior to its use in microchip capillary electrophoresis. The performance of this device with amperometric detection for the separation of dopamine and catechol was examined. The separation was complete within 50 s at an applied potential of 200 V/cm. The relative standard deviations (RSD) of analyte migration times were less than 0.71%, and the theoretical plate numbers for dopamine and catechol were 3.2 x 10(4) and 4.1 x 10(4), respectively, based on a 65 min separation channel. (c) 2005 Elsevier B.V. All rights reserved.
Fatigue of cracked plates repaired with single-sided composite patches
(1998-04-01)
Kam, TY
;
Chu, KH
;
Tsai, YC
;
機械工程學系
;
Department of Mechanical Engineering
Fatigue of cracked plates repaired with single sided composite patches is studied via both analytical and experimental approaches. A finite element model, which considers out-of-plane bending effects induced by asymmetric repair, is presented to determine the crack tip opening displacements of the repaired plates subjected to in-plane loading. The modified crack closure technique is used to calculate the stress intensity factor of the repaired plates. Fatigue life of the repaired plates is studied via the use of Paris tan for crack propagation. The effects of cracked plate and composite patch thicknesses on the fatigue track propagation of repaired plates containing different types of cracks are investigated. Fatigue tests of aluminum C-T specimens repaired with single-sided composite patches are performed, and the test data are used to validate the analytical approach. It has been shown that the repair of a cracked plate with a single-sided composite patch may have beneficial or adverse effects on the fatigue life of the repaired plate depending on the thicknesses of the patch and the cracked plate.
On-line preconcentration and determination of ketamine and norketamine by micellar electrokinetic chromatography - Complementary method to gas chromatography/mass spectrometry
(2006-04-14)
Jen, HP
;
Tsai, YC
;
Su, HL
;
Hsieh, YZ
;
應用化學系
We have investigated a rapid, simple, and highly efficient on-line preconcentration method using in micellar electrokinetic chromatography (MEKC) for the analysis of abused drugs. Ketamine is an anesthetic that has been abused as a hallucinogen. We applied the sample sweeping technique first to ketamine and its major metabolite, norketamine, and separated the analytes with MEKC. Several of the sweeping MEKC parameters to effect successful separations, such as the concentration of sodium dodecyl sulfate (SIDS), the injection time, and the applied voltage were optimized. The improvements in the number of theoretical plates under the different separation conditions are presented clearly in a three-dimensional representation. The limits of detection were 2.8, 3.4, and 3.3 ng/mL for ketamine, norketamine, and ketamine-D-4, respectively. The enrichment factor for each compound was within the range of 540-800. Experimental results are in agreement with those of analysis conducted by gas chromatography/mass spectroscopy (GC/MS). Therefore, we believe that sweeping, combined with MEKC, represents a suitable complementary method to GC/MS for use in clinical and forensic analyses of ketamine and norketamine. (c) 2005 Elsevier B.V. All rights reserved.
Optimal information-dispersal for fault-tolerant communication over a burst-error channel
(2003-09-01)
Shieh, SP
;
Tsai, YC
;
Huang, YL
;
資訊工程學系
;
Department of Computer Science
The (m, n) wireless information dispersal scheme (WIDS) is useful for fault-tolerant parallel wireless communications, where it can be used to tolerate up to n - m path (subchannel) failures. This paper constructs a performance model of (m, n) WIDS used in wireless communications, and proposes an algorithm to find the optimal set of (m, n) with the highest reliability. This algorithm reduces the complexity of finding the candidate set of (m, n) from O(N-2) to O(N); N is the maximum number of available sub-channels.
Ozonation of domestic secondary effluent for recycling and reuse - a pilot plant study
(2002)
Ni, CH
;
Chen, JN
;
Tsai, YC
;
Chen, WB
;
Chen, CH
In this study, a pilot plant combined ozonation with sand filtration is established. Wastewater from the secondary effluent was taken as the sample for looking into the feasibility of domestic wastewater recovery and recycling. At the beginning, a series of hydraulic analysis and ozone transfer tests was conducted in the bubble column reactor. From these tests, it was found that when the gas flow is controlled to within 0.2similar to1.0 L/min and liquid flow within 0.5similar to2.5 L/min, using series connected mixing tank model for our calculation, the result J (CSTR) is 1similar to2. From the ozone transfer test it is known that the smaller the gas flow, the better the transfer rate, and the same pattern occurs on ozone gas concentration. After sand filtration and ozone treatment, the G/L ratio within the ozone column reactor can be maintained within 0.2similar to0.4 and the ozone dosage within 8similar to12 mg/L. The removal rate for coliform bacillus, BOD, turbidity and color is 99.96%, 62.2%, 89.6% and 67% respectively. After ozonation treatment, coliform bacillus content can be controlled under 10 CFU/mL, BOD under 10mg/L, turbidity within 2.0similar to2.5 (NTU), and color within 10.3similar to13.7 degree. The recycled water is almost colorless and odorless, and is capable of reaching the reference standard for recycled water.
Recycling and reuse of wastewater from a new-developed community using sand filtration, ultrafiltration, and ozonation
(2003)
Ni, CH
;
Chen, JN
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Tsai, YC
;
Chen, TK
;
Chen, WB
In this study, the pilot apparatus combined with sand filtration, ozonation and ultrafiltration was established. Wastewater from the secondary treatment effluent in the new-developed community was taken as the sample for looking into the feasibility of domestic wastewater reuse and recycling. The test results by sand filtration, sand filtration/ultrafiltration, sand filtration/ozonation, and sand filtration/ultrafiltration/ozonation were compared for looking for appropriate treatment processes applied in the domestic wastewater reuse and recycling, Finally, cost analysis was carried out and sand filtration/ozonation process was suggested to be one of the best processes. The total cost is about 0.1-0.32 $USD per cubic meter of produced water by considering the capital and operation cost for five years in the small domestic wastewater treatment plant (50-750 CMD).
The improved shielding method of linear antenna on a cellular telephone
(1998)
Tsai, YC
;
Wu, JJ
;
Jou, CF
;
電信工程研究所
;
Institute of Communications Engineering
In this paper, a simple method which may protect the human head from the potential danger of electromagnetic (EM) radiation in hairy use of cellular telephones, especially in microwave region, is presented[1]. It is possible to achieve high levels of shielding effectiveness by simply pasting a metal wire on the dipole antenna of the cellular telephones. Several materials (such as absorber, iron and copper) are tested, and we find the optimum one is the copper wire. As comparing to the case without shielding, this method can effectively reduce SAR (specific absorption rare-SAR) in the head by 3dB or more. Besides, this shielding of radiation power is extremely low in cost and ideally suitable for using in cellular telephones and other sources of EM radiation.