Browsing by Author "Lin, JD"

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A theoretical model for the nongray radiation drying of polyvinylalcohol/water solutions
(2004)
Chen, JJ
;
Lin, JD
;
機械工程學系
;
Department of Mechanical Engineering
A theoretical analysis of heat transfer and moisture variation was performed while a PVA solution was exposed to high-intensity nongray irradiation and/or air flow convection. Effective absorption coefficients were incorporated in the radiative transfer analysis. The influence of various radiation and convection parameters on the transfer of heat and moisture variation in the coated layers on an optically thick substrate was investigated. The effects of radiation and convection parameters on the transfer process were presented in terms of the rate of water content removal, heat transfer, and moisture distribution. Results were compared to those of drying when using convective heat. It is evident that the use of thermal radiation combined with convective heat will help in improving the drying rate. Numerical results show that both the radiative energy absorbed by the solution and the substrate and the distribution of water mass fraction in the solution are closely related to the rate of water removal from the solution during the process.
An aberrant autocrine activation of the platelet-derived growth factor alpha-receptor in follicular and papillary thyroid carcinoma cell lines
(2006-01-18)
Chen, KT
;
Lin, JD
;
Liou, MJ
;
Weng, HF
;
Chang, CA
Platelet-derived growth factor receptor (PDGFR) can bind to its ligand and consequently possess a kinase activity, and which is associated with the carcinogenesis of different cell types, including astrocytomas, oligodendrogliomas. and glioblastoma. In a cDNA microarray analysis, we observe the over-expressed mRNA of both PDGF-A and PDGF-alpha receptor in thyroid carcinoma cells. And the elevated protein expressions of PDGF-A and PDGF-alpha receptor in thyroid carcinoma cells were also confirmed by a Western blot analysis. The phosphorylation of PDGF-alpha receptor evaluated by an antibody against Tyr 720-phosphate was found in thyroid carcinoma cells. The tyrosine kinase activity of PDGF-alpha receptor was inhibited by tyrphostin AG1295 and showed a dose-dependent inhibition for the proliferation of thyroid carcinoma cells. These findings imply that autocrine activation of PDGF-alpha receptor plays a crucial role in the carcinogenesis of thyroid cells. (c) 2005 Elsevier Ireland Ltd. All rights reserved.
An analysis for measurement of thermal diffusivity components of anisotropic platelike samples by AC calorimetric method
(2000-07-01)
Sheu, LJ
;
Lin, JD
;
機械工程學系
;
Department of Mechanical Engineering
This work examines the effects of anisotropy and transparency on measurements of thermal diffusivity components with an ac calorimetric method associated with laser heating. Analytical results indicate that the region where the two-dimensional effect occurs increases with the decrease of the ratio of cross-plane to in-plane thermal diffusivity. The region also increases with the optical thickness of the sample. The linear relations, as indicated by a decay constant from which the cross-plane thermal diffusivity is deduced, are not obtained for media of both optically moderate and thin thickness, while at sufficiently large optical thickness, anisotropy and two-dimensional effects are found insignificant.
Analysis of heat and mass transfer in drying processes of polymer solution using high-intensity infrared radiation
(1996)
Chen, JJ
;
Lin, JD
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Engineering phosphors for improved brightness
(2002-12-01)
Lin, CH
;
Chiou, BS
;
Lin, JD
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Factors affecting the cathodoluminescent (CL) efficiency of phosphors include: morphology, size, stoichiometry, composition, and surface of the phosphors. In the design of phosphors for low-voltage operations, processes such as surface etching are used to enhance phosphor efficiency. In this study, zinc-activated ZnO phosphors were subjected to three processes: acid etching, ball milling, and/or ultrasonic vibration, and the effect of each process on the CL efficiency studied. It is found that the brightness of phosphors increases 40% after ultrasonic vibration followed by etching twice with 0.005 M HNO3. (C) 2002 Kluwer Academic Publishers.
Identifying differentially expressed genes associated with metastasis of follicular thyroid cancer by cDNA expression array
(2001-01-01)
Chen, KT
;
Lin, JD
;
Chao, TC
;
Hsueh, C
;
Chang, CA
Patients with follicular thyroid carcinoma have a higher incidence of metastasis than papillary thyroid carcinoma when thyroid cancer is diagnosed. The cDNA expression array technology is utilized herein to profile differentially expressed genes from metastatic human follicular thyroid carcinoma and reveal new tumor markers as well as target genes for therapeutic intervention. Tissue samples were obtained during surgical resection of the thyroid follicular carcinoma and metastatic tissue in the brain of the same patient. Two identical Atlas human cDNA expression arrays were hybridized with P-32-labeled cDNA probes derived from RNA of either primary thyroid cancer or metastatic tissue. Parallel analysis of the hybridized signals allowed us to identify the alteration of gene expression in the metastasis process. Eighteen genes significantly overexpressed and 40 genes significantly underexpressed were identified in the metastatic thyroid cancer. Genes that displayed an altered expression were associated with the processes of cell cycle regulation, apoptosis, DNA damage response, angiogenesis, cell adhesion and mobility, invasion, and immune response. An expression profile of genes that are associated with metastasis process of follicular thyroid cancer was also discussed. Further investigation is required to understand the precise relationship between the altered expression of these genes and the metastasis process of follicular thyroid cancer.
Laboratory testing of three direct reading dust monitors
(1996-06-01)
Tsai, CJ
;
Shih, TS
;
Lin, JD
;
機械工程學系
;
環境工程研究所
This study used a dust chamber to test the response of three direct reading dust monitors, GCA MINIRAM PDM-3, Sibata PCD-1, and TSI 8510, to different dust materials having similar size distributions. Total dust concentrations obtained by open-face filters were used as standards for comparing total dust concentration readings, while respirable dust concentrations calculated from particle size distribution measured by the MOUDI cascade impactor were used as standards for comparing respirable dust concentration readings. It was found that the GCA MINIRAM PDM-3 was accurate within +10-16% in regard to total dust concentration, independent of dust material. The calibration constant k of the Sibata PCD-1 was close to 6.0 for both quartz and SAE fine dusts and was independent of dust concentrations. However, for carbon particles, k remains nearly constant from 13-16 only when the total dust concentration is greater than 3.0 mg/m(3). The TSI 8510 seriously underestimates the concentration of SAE fine dust, and is more accurate for quartz and carbon dusts when respirable dust concentration is less than 6.0 mg/m(3). When respirable dust concentration is greater than 6.0 mg/m(3), it will also underestimate quartz dust concentration substantially, while it remains accurate for carbon dust.
Numerical analysis on hot spot in reactive chemical storage
(1998)
Sheu, LJ
;
Lin, JD
;
Chen, JR
;
機械工程學系
;
Department of Mechanical Engineering
In an exothermic reactive chemical storage, a thermal explosion can occur when the heat generation within the storage is greater than heat removal from the storage. In a solid system, the existence of an inflection point in the temperature versus time curve is often used as a criterion for thermal explosion. In this study the applicability of this criterion to a fluid storage is examined by investigating the hot spot in the system. Transient natural convection of an exothermically reactive fluid in the vertical cylindrical storage tank with isothermal walls is investigated numerically. The axisymmetric 2-D Navier-Stokes equations governing the now fields are reduced by introducing the stream function-vorticity formulation and solved by the alternating-direction-implicit (ADI) technique. The reactive heat sources are represented by a zeroth order rate expression with a Arrhenius type rate constant. It is found that the hot spot is no longer located in the center of the tank due to the buoyancy effect. In a particular range of Rayleigh number and Frank-Kamenetskii number, the hot spot is found to move periodically. A stable steady regime, stable oscillatory regime and thermal explosion regime can be specified based on the dependence of the critical Frank-Kamenetskii number on the Rayleigh number. In the stable oscillatory regime multiple inflections in temperature versus time are found. Therefore, the existing criterion which defines thermal explosion by the appearance of an inflection in the temperature versus time curve is no longer applicable in reactive fluid systems. The results of nonconvective systems do, however, provide a preliminary and conservative estimate for thermal explosion of a reactive storage.
Preparation and cathodoluminescence of ZnO phosphor
(2003-01-30)
Lin, CH
;
Chiou, BS
;
Chang, CH
;
Lin, JD
;
電子工程學系及電子研究所
Zinc oxide phosphors (ZnO:Zn) were prepared with solid state sintering of ZnO powders with ZnS and screen printed onto ITO-coated glass substrates to form a thin layer. Structural characterization carried out by X-ray diffraction (XRD) analysis suggests that the Zn atoms originated from the decomposition of ZnS, and diffuse to occupy the oxygen vacancies in the host lattice. Both lattice parameters a and c decrease slightly with the increase of ZnS content and/or firing temperature. The cathodoluminescent (CL) peak band varies with ZnS content and ranges from 494 to 508 nm, which is close to the green band of ZnO phosphor. Various mechanisms have been proposed in literatures to explain the origin of the green emission band. Among them, the presence of oxygen vacancies and trace ZnS residue are possible causes for the green emission in this study. CL spectra and CIE color loci suggest that ZnO:Zn phosphor with 5 wt.% ZnS can be. used as a green primary for color picture tubes. (C) 2002 Elsevier Science B.V. All rights reserved.
Simultaneous heat and mass transfer in polymer solutions exposed to intermittent infrared radiation heating
(1998-06-01)
Chen, JJ
;
Lin, JD
;
機械工程學系
;
Department of Mechanical Engineering
A theoretical study is performed that describes heat transfer and moisture variation while a polymer solution is exposed to high-intensity infrared radiation flux and/or an airflow. While the intermittent heating is considered, we investigate the influences of various radiation and convection parameters on the transfer of heat and moisture variation of coated layers on an optically thick substrate. During the tempering stage in the intermittent heating process, the convective mass transfer is included to simulate the ambient air in reality. The effects of radiation and convection parameters on the transfer processes are presented in terms of the rate of water content removal, heat transfer, and moisture distributions. Numerical results show that the rate of water removal from the polymer solution is dominated by both the absorbed radiative heat energy and the distributions of water mass fraction in the polymer solution.
Simultaneous measurement of spectral optical properties and thickness of an absorbing thin film on a substrate
(1999-10-08)
Chen, JJ
;
Lin, JD
;
Sheu, LJ
;
機械工程學系
;
Department of Mechanical Engineering
This paper describes a technique and also illustrates an application of the technique for simultaneously measuring both the spectral complex refractive index (n(1),k(1)) and the thickness d(1) of an absorbing thin solid layer on a thick substrate. The contours of constant reflectance R and transmittance T in the (n(1), k(1)), (n(1), d(1)) and (k(1), d(1)) planes are examined for a thin layer on a substrate, which is exposed to oblique unpolarized incidence, under various conditions in order to facilitate an optimal choice of the combination of measured quantities for the inverse estimation of parameters. Theoretical analysis illustrates that optimal choices would include measurement of R at a large angle of incidence, combined with measurements of normal T and near normal R so as to reduce erroneous solutions or nonconvergence. And any additional measurement R at any angle of incidence may be used to prevent the multiple solutions. For the inverse estimation of parameters, we also present a technique in association of the least squares method to extract the thickness and optical constants characterizing the thin absorbing film from measurements of R and T. The method is then applied for experimental measurement of the optical properties and thickness of a polyvinylalcohol (PVA) film placed upon a substrate of ZnSe. These results provide useful information for analyses on the applications of PVA in textile sizing, adhesives, polymerization stabilizers, and paper coating. (C) 1999 Elsevier Science S.A. All rights reserved.
The effect of ZnS content on the luminescence and electrical properties of ZnO : Zn phosphor
(2002)
Lin, CH
;
Chiou, BS
;
Chang, CH
;
Lin, JD
;
電子工程學系及電子研究所
Zinc oxide phosphors (ZnO : Zn) were prepared by solid state sintering of ZnO powders with ZnS and screen printed onto ITO-coated glass substrate. The effect of ZnS content and sintering temperature on the cathodoluminescence brightness, efficiency and electrical properties of ZnO : Zn were studied. Samples with 5 wt % ZnS and sintered at 1100 degreesC exhibit the highest brightness and efficiency among all the compositions studied. The brightness of phosphors increases linearly as the accelerating voltage V and/or beam current I increases. While the efficiency decreases initially and then reaches a constant value as V and/or I increases. Both the conductivity sigma and carrier concentration n of the phosphor increase with the increase of ZnS content in the starting composition. Results of Hall measurement suggest that the ZnO : Zn phosphor is an n-type conductor with an electron mobility of around 175cm(2)/V-s. For specimen with 5 wt % ZnS, both sigma and n increases initially with the increase of sintering temperature T, and reaches a constant value at T greater than or equal to 1000 degreesC. The unreacted ZnS found in samples sintered at T < 1000 degreesC explains the temperature dependence of sigma and n. (C) 2002 Kluwer Academic Publishers.
The influence of washing and calcination condition on urea-derived ceria-yttria-doped tetragonal zirconia powders
(2001-02-15)
Lin, JD
;
Duh, JG
;
Chiou, BS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The influence of washing and calcination conditions on the powder characteristics of urea-derived ceria-yttria-doped tetragonal zirconia powders (Ce-Y-TZP) ceramics are studied. The use of urea hydrolysis followed by acetone-toluene-acetone (ATA) washing can produce a finer and more sinterable Ce-Y-TZP powder as compared to that washed by alcohol. It is observed that as the calcination temperature is raised to 800 degreesC for 2 h, the sintered density achieves the highest value regardless of the increase of monoclinic content in as-derived powders. The higher the calcination temperature, the more the monoclinic content. The transformability of tetragonal phase is related to the A, temperature and tetragonality. The monoclinic content in as-derived powders after calcination and ball-milling processes is proportional to the A, temperature and tetragonality of tetragonal phase. (C) 2001 Elsevier Science B.V. All rights reserved.
Theoretical analysis on drying of polymer solution with continuous or intermittent heating by high-intensity infrared radiation
(1998)
Chen, JJ
;
Lin, JD
;
機械工程學系
;
Department of Mechanical Engineering
A theoretical study is performed that describes the heat transfer and moisture variation during drying process while the polymer solution is exposed to the high-intensity infrared radiation flux and hot air. We examine the effects of various parameters on the drying of coated film on a thick substrate. The effects of external heating conditions on drying are presented in terms of the drying rate, heat transfer as well as the moisture distribution. Numerical results show that the absorbed radiative heat energy in the polymer solution is dominant on drying rate of polymer solution during the process. The numerical results are also compared to widely-used thermal-lumped approximation to illustrate the validity of the approximation. While the intermittent heating is considered during drying, the energy consumption and flexible heating design are examined and we investigate the influences of various drying stages and external heating on the drying characteristics.
Thermocapillary effect on drying of a polymer solution under non-uniform radiant heating
(2000-06-01)
Chen, JJ
;
Lin, JD
;
機械工程學系
;
Department of Mechanical Engineering
This theoretical investigation analyzes the two-dimensional heat and mass transfer characteristics arising from the cion-uniform radiant incidence in polymer solutions whose motion is governed by combined thermocapillary/ buoyancy laminar flow. Also considered herein is the evaporation of solvent at solution surface. The effects of various radiation input, external convective parameters, and important physical properties of solutions on the drying characteristics are investigated and results are presented in terms of flow, thermal, and concentration fields, and rate of water removal. In addition, the influence of thermocapillary effect on drying features is also examined. Numerical results indicate that absorbed energy and distribution of the solvent concentration dominate the drying rate. At larger surface tension Reynolds number, more mass concentration can be transferred by thermocapillary flow from the interior region to the surface, which then increases drying rate. Furthermore, removing the solid wall effect reduces the drying time required for a solution film with two sides of symmetric surfaces, which is irradiated by an array of infrared radiant heaters. (C) 2000 Elsevier Science Ltd. All rights reserved.
Two-dimensional electrophoretic analysis of membranous protein from human thyroid tissues and cancer cell lines
(1998-12-01)
Lin, JD
;
Chan, EC
;
Weng, HF
;
Sheu, CA
;
生物科技學系
Thyroid neoplasm is the most commonly encountered neoplastic disorder in endocrine clinics. Thyroid scan, ultrasonography, and fine needle aspiration cytology (FNAC) are used as diagnostic tools to differentiate a malignant nodule from a benign lesion. There are certain limitations and pitfalls in FNAC, especially in the diagnosing of follicular tumors. The lack of characteristic findings or a specific tumor marker are the most common problems in the preoperative diagnosis of thyroid follicular carcinoma. Although serum thyroglobulin level has been used as a tumor marker for post-operative, well-differentiated thyroid cancer, the assay cannot be used for preoperative diagnosis of thyroid carcinoma. In this study, various thyroid tissues and cancer cell lines including CGTH W-1, CGTH W-3, RO 82 W-1, SW 579 cell lines were used for the investigation of tumor markers. Specific spots were identified in the area near the 60 kDa molecular mass protein and isoelectric point (pI) 5.9 of the CGTH W-1 cell line. These spots could not be found in the papillary or anaplastic thyroid cancer cell lines. Another spot with a molecular weight of about 9.8 kDa with a low pI of 4.8 was present in the CGTH W-1 and RO 82 W-1 cell lines. This spot appeared to be a tumor marker of follicular cancer cells. This spot could not be found in the papillary and anaplastic cancer cell lines and other benign thyroid tissues. Specific proteins that were identified in this study may be useful as tumor markers for follicular thyroid carcinoma.
Two-dimensional electrophoretic analysis of membranous protein from human thyroid tissues and cancer cell lines
(1998-12-01)
Lin, JD
;
Chan, EC
;
Weng, HF
;
Sheu, CA
;
生物科技學系
Thyroid neoplasm is the most commonly encountered neoplastic disorder in endocrine clinics. Thyroid scan, ultrasonography, and fine needle aspiration cytology (FNAC) are used as diagnostic tools to differentiate a malignant nodule from a benign lesion. There are certain limitations and pitfalls in FNAC, especially in the diagnosing of follicular tumors. The lack of characteristic findings or a specific tumor marker are the most common problems in the preoperative diagnosis of thyroid follicular carcinoma. Although serum thyroglobulin level has been used as a tumor marker for post-operative, well-differentiated thyroid cancer, the assay cannot be used for preoperative diagnosis of thyroid carcinoma. In this study, various thyroid tissues and cancer cell lines including CGTH W-1, CGTH W-3, RO 82 W-1, SW 579 cell lines were used for the investigation of tumor markers. Specific spots were identified in the area near the 60 kDa molecular mass protein and isoelectric point (pI) 5.9 of the CGTH W-1 cell line. These spots could not be found in the papillary or anaplastic thyroid cancer cell lines. Another spot with a molecular weight of about 9.8 kDa with a low pI of 4.8 was present in the CGTH W-1 and RO 82 W-1 cell lines. This spot appeared to be a tumor marker of follicular cancer cells. This spot could not be found in the papillary and anaplastic cancer cell lines and other benign thyroid tissues. Specific proteins that were identified in this study may be useful as tumor markers for follicular thyroid carcinoma.