Browsing by Author "Lu, Chih-Wei"

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Blue/near UV light emission from hybrid InN/TiO(2) nanoparticle films
(2011-01-01)
Wu, Chih-Wei
;
Lu, Chih-Wei
;
Lee, Yuan-Pern
;
Wu, Yu-Jong
;
Cheng, Bing-Ming
We report on the enhancement of photoluminescence (PL) from anatase TiO(2) thin films covered by InN nanoparticles prepared using plasma enhanced chemical vapor deposition (PECVD). The SEM images and X-ray diffraction spectra illustrate the strong interaction between the InN particles and the TiO(2) films. UV-Vis absorption spectra indicate that the InN particles have an increased absorption in the visible light region and may sensitize the TiO(2) films. The strong PL band observed in the anatase TiO(2) thin films with the addition of InN may have been due to an increased localization of impurities and/or defect-trapped excitons.
Blue/near UV light emission from hybrid InN/TiO2 nanoparticle films
(2011-01-01)
Wu, Chih-Wei
;
Lu, Chih-Wei
;
Lee, Yuan-Pern
;
Wu, Yu-Jong
;
Cheng, Bing-Ming
We report on the enhancement of photoluminescence (PL) from anatase TiO2 thin films covered by InN nanoparticles prepared using plasma enhanced chemical vapor deposition (PECVD). The SEM images and X-ray diffraction spectra illustrate the strong interaction between the InN particles and the TiO2 films. UV-Vis absorption spectra indicate that the InN particles have an increased absorption in the visible light region and may sensitize the TiO2 films. The strong PL band observed in the anatase TiO2 thin films with the addition of InN may have been due to an increased localization of impurities and/or defect-trapped excitons.
Diffuse Optical Multipatch Technique for Tissue Oxygenation Monitoring: Clinical Study in Intensive Care Unit
(2012-01-01)
Wang, Chun-Yang
;
Chuang, Ming-Lung
;
Liang, Shinn-Jye
;
Tsai, Jui-che
;
Chuang, Ching-Cheng
Diffuse optical multipatch technique is used to assess spatial variations in absorption and scattering in biological tissue, by monitoring changes in the concentration of oxyhemoglobin and deoxyhemoglobin. In our preliminary study, the temporal tracings of tissue oxygenation are measured using diffuse optical multipatch measurement and a venous occlusion test, employing normal subjects and ICU patients suffering from sepsis and heart failure. In experiments, obvious differences in tissue oxygenation signals were observed among all three groups. This paper discusses the physiological relevance of tissue oxygenation with respect to disease.
Experimental and theoretical investigation of rate coefficients of the reaction S(P-3)+OCS in the temperature range of 298-985 K
(2006-10-28)
Lu, Chih-Wei
;
Wu, Yu-Jong
;
Lee, Yuan-Pern
;
Zhu, R. S.
;
Lin, M. C.
The reaction S(P-3)+OCS in Ar was investigated over the pressure range of 50-710 Torr and the temperature range of 298-985 K with the laser photolysis technique. S atoms were generated by photolysis of OCS with light at 248 nm from a KrF excimer laser; their concentration was monitored via resonance fluorescence excited by atomic emission of S produced from microwave-discharged SO2. At pressures less than 250 Torr, our measurements give k(298 K)=(2.7 +/- 0.5)x10(-15) cm(3) molecule(-1) s(-1), in satisfactory agreement with a previous report by Klemm and Davis [J. Phys. Chem. 78, 1137 (1974)]. New data determined for 407-985 K connect rate coefficients reported previously for T >= 860 and T <= 478 K and show a non-Arrhenius behavior. Combining our results with data reported at high temperatures, we derived an expression k(T)=(6.1 +/- 0.3)x10(-18) T-1.97 +/- 0.24 exp[-(1560 +/- 170)/T] cm(3) molecule(-1) s(-1) for 298 <= T/K <= 1680. At 298 K and P >= 500 Torr, the reaction rate was enhanced. Theoretical calculations at the G2M(CC2) level, using geometries optimized with the B3LYP/6-311+G(3df) method, yield energies of transition states and products relative to those of the reactants. Rate coefficients predicted with multichannel Rice-Ramsperger-Kassel-Marcus (RRKM) calculations agree satisfactorily with experimental observations. According to our calculations, the singlet channel involving formation of SSCO followed by direct dissociation into S-2(a (1)Delta(g))+CO dominates below 2000 K; SSCO is formed via intersystem crossing from the triplet surface. At low temperature and under high pressure the stabilization of OCS2, formed via isomerization of SSCO, becomes important; its formation and further reaction with S atoms partially account for the observed increase in the rate coefficient under such conditions. (c) 2006 American Institute of Physics.
Hemodynamic analysis of patients in intensive care unit based on diffuse optical spectroscopic imaging system
(2010)
Hsieh, Yao-Sheng
;
Wang, Chun-Yang
;
Ling, Yo-Wei
;
Chuang, Ming-Lung
;
Chuang, Ching-Cheng
Diffuse optical spectroscopic imaging (DOSI) is a technique to assess the spatial variation in absorption and scattering properties of the biological tissues and provides the monitoring of changes in concentrations of oxy-hemoglobin and deoxy-hemoglobin. In our preliminary study, the temporal tracings of hemodynamic oxygenation are measured with DOSI and venous occlusion test (VOT) from normal subjects, patients with heart failure and patients with sepsis in intensive care unit (ICU). In experiments, the obvious differences of hemodynamic signals can be observed among the three groups. The physiological relevance of VOT hemodynamics with respect to diseases is also discussed in this paper.
Study on dynamics of photon migration in human breast based on three-dimensional Monte Carlo modeling
(2010-01-01)
Chuang, Ching-Cheng
;
Chen, Chung-Ming
;
Lee, Chia-Yen
;
Tsai, Jui-che
;
Lu, Chih-Wei
The scattering and absorption properties of human breast are very important for cancer diagnosis based on diffuse optical tomography (DOT). In this study, the dynamics of photon migration in three-dimensional human breast model with various source-detector separations is simulated based on a Monte Carlo algorithm. The three-dimensional human breast structure is obtained from in vivo MRI image. The breast model consists of skin, fatty tissue, glandular tissue, sternum and ribcage. The backscattered diffuse photons from each layer in breast are recorded by marking the deepest layer which every photon can reach. The experimental results indicate that the re-emitted photons contain more information from deep tissue regions with the source-detector separations because of the strong dependence to the resolution and sensitivity in DOT imaging. The geometric position of the source-detector separations were optimized in this study. The different sizes of breast tumor were modeled to analysis of optical image characterizations. Finally, the tumor images from different deep information were obtained with temporal profiles.
Subgingival calculus imaging based on swept-source optical coherence tomography
(2011-07-01)
Hsieh, Yao-Sheng
;
Ho, Yi-Ching
;
Lee, Shyh-Yuan
;
Lu, Chih-Wei
;
Jiang, Cho-Pei
We characterized and imaged dental calculus using swept-source optical coherence tomography (SS-OCT). The refractive indices of enamel, dentin, cementum, and calculus were measured as 1.625 +/- 0.024, 1.534 +/- 0.029, 1.570 +/- 0.021, and 2.097 +/- 0.094, respectively. Dental calculus leads strong scattering properties, and thus, the region can be identified from enamel with SS-OCT imaging. An extracted human tooth with calculus is covered with gingiva tissue as an in vitro sample for tomographic imaging. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3602851]
The Development of Cloud Computing and Its Challenges for Taiwan
(2012)
Chu, William C.
;
Chang, Chih-Hung
;
Lu, Chih-Wei
;
Chen, Juei-Nan
;
Wang, Feng-Jian
Along with the growing attention, cloud computing is not only changing the computing paradigm, but also the style of computing in which dynamically scalable and virtualized resources are provided as services over the Internet. Cloud computing introduces a lot of chances, as well as, challenges in the new trend. Taiwan has been well known as a major Information Communication Technology (ICT) manufacturing traditionally. Many Taiwan\'s hardware products have been top ranked in the global market. Taiwan has realized the trend that Cloud Computing is leading to and has reacted to integrate its resources from the government, industry, academia, and research centers, by initiating strong incentive programs for cloud computing, with an intension to transform an ICT Island into a Cloud Village. In this article, we describe the status of the development of cloud computing technologies and its future challenges for Taiwan.