Browsing by Issue Date, starting with "2019-11-12"

Now showing 1 - 20 of 6455

Effects of TiO2 and SDC addition on the properties of YSZ electrolyte
(2019-11-12)
Shen, Chin-Tien
;
Lee, Kan-Rong
;
Hsieh, Yu-Pin
;
Lee, Sheng-Wei
;
Chang, Jeng-Kuei
In this study, we investigate the effects of adding titanium dioxide (TiO2) and samarium doped cerium oxide (SDC) on the properties of yttrium-stabilized zirconia (YSZ) electrolyte. The microstructure, mechanical, and electrochemical properties of the electrolyte are investigated. The performance in CO2 electrolysis is measured by supplying carbon dioxide to Ni-YSZ electrode and nitrogen to LSM electrode. Results show that TiO2 and SDC addition can reduce the sintering temperature and increase grain size. The ionic conductivity is 0.123 S cm(-1) at 1000 degrees C. In addition, the thermal expansion coefficient at 1000 degrees C is 8.25 x 10(-6)K(-1). The current density of the cell is 439 mA cm(-2) at 1.3 V and 1000 degrees C in solid oxide electrolysis cell. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Morphological and Molecular Defects in Human Three-Dimensional Retinal Organoid Model of X-Linked Juvenile Retinoschisis
(2019-11-12)
Huang, Kang-Chieh
;
Wang, Mong-Lien
;
Chen, Shih-Jen
;
Kuo, Jean-Cheng
;
Wang, Won-Jing
X-linked juvenile retinoschisis (XLRS), linked to mutations in the RS1 gene, is a degenerative retinopathy with a retinal splitting phenotype. We generated human induced pluripotent stem cells (hiPSCs) from patients to study XLRS in a 3D retinal organoid in vitro differentiation system. This model recapitulates key features of XLRS including retinal splitting, defective retinoschisin production, outer-segment defects, abnormal paxillin turnover, and impaired ER-Golgi transportation. RS1 mutation also affects the development of photoreceptor sensory cilia and results in altered expression of other retinopathy-associated genes. CRISPR/Cas9 correction of the disease-associated C625T mutation normalizes the splitting phenotype, outer-segment defects, paxillin dynamics, ciliary marker expression, and transcriptome profiles. Likewise, mutating RS1 in control hiPSCs produces the disease-associated phenotypes. Finally, we show that the C625T mutation can be repaired precisely and efficiently using a base-editing approach. Taken together, our data establish 3D organoids as a valid disease model.
Minimizing machine assignment costs over Delta-approximate solutions of the scheduling problem P parallel to C-max
(2019-11-12)
Kononov, A. V.
;
Kovalyov, M. Y.
;
Lin, B. M. T.
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Bi-criteria lexicographical minimization problems with the makespan as the primary objective and the total machine assignment costs as the secondary objective have been recently introduced to the scheduling research, and polynomial time (r + 1, 1)-approximation algorithms have been suggested for their solution, where 1 < r < 2 is the performance ratio of an approximation algorithm for P parallel to C-max. We improve these results by presenting a polynomial time (1.5r - 1, 1)-approximation algorithm for the additive cost type. Then, we introduce a problem of minimizing the total machine assignment cost over the Delta-approximate solutions of the makespan minimization problem. We prove that this new problem is strongly NP-hard and pseudo-polynomially non-approximable in general. A polynomial time approximation algorithm with a guaranteed approximation ratio is presented for the additive cost type and bounded ratio between the maximal and minimal machine costs. An O (mn(2k)) time dynamic programming algorithm is also presented, where k is the fixed number of distinct job processing times. (C) 2019 Elsevier B.V. All rights reserved.
Composition Modulation of Ionic Liquid Hybrid Electrolyte for 5 V Lithium-Ion Batteries
(2019-11-13)
Wu, Chia-Jung
;
Rath, Puma Chandra
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Patra, Jagabandhu
;
Bresser, Dominic
;
Passerini, Stefano
Electrolyte is a key component in high-voltage lithium-ion batteries (LIBs). Bis(trifluoromethanesulfonyl)imide-based ionic liquid (IL)/organic carbonate hybrid electrolytes have been a research focus owing to their excellent balance of safety and ionic conductivity. Nevertheless, corrosion of Al current collectors at high potentials usually happens for this kind of electrolyte. In this study, this long-standing problem is solved via the modulation of the IL/carbonate ratio and LiPF6 concentration in the hybrid electrolyte. The proposed electrolyte suppresses Al dissolution and electrolyte oxidation at 5 V (vs Li+/Li) and thus allows for ideal lithiation/delithiation performance of a high-voltage LiNi0.5Mn1.5O4 (LNMO) cathode even at 55 degrees C. The underlying mechanism is examined in this work. Excellent cycling stability (97% capacity retention) for an LNMO cathode after 300 cycles is achieved. This electrolyte shows good wettability toward a polyethylene separator and low flammability. In addition, satisfactory compatibility with both graphite and Si-based anodes is confirmed. The proposed electrolyte design strategies have great potential for applications in high-voltage LIBs.
Role of precursors mixing sequence on the properties of CoMn2O4 cathode materials and their application in pseudocapacitor
(2019-11-14)
Pattanayak, Bhaskar
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Simanjuntak, Firman Mangasa
;
Panda, Debashis
;
Yang, Chih-Chieh
;
Kumar, Amit
In this study, the effect of oxygen vacancy in the CoMn2O4 on pseudocapacitive characteristics was examined, and two tetragonal CoMn2O4 spinel compounds with different oxygen vacancy concentrations and morphologies were synthesized by controlling the mixing sequence of the Co and Mn precursors. The mixing sequence was changed; thus, morphologies were changed from spherical nanoparticles to nanoflakes and oxygen vacancies were increased. Electrochemical studies have revealed that tetragonal CoMn2O4 spinels with a higher number of oxygen vacancies exhibit a higher specific capacitance of 1709 F g(-1) than those with a lower number of oxygen vacancies, which have a higher specific capacitance of 990 F g(-1). Oxygen vacancies create an active site for oxygen ion intercalation. Therefore, oxidation-reduction reactions occur because of the diffusion of oxygen ions at octahedral/tetrahedral crystal edges. The solid-state asymmetric pseudocapacitor exhibits a maximum energy density of 32 Wh.kg(-1) and an excellent cyclic stability of nearly 100%.
Formation Mechanism and Fluorescence Characterization of a Transient Assembly of Nanoparticles Generated by Femtosecond Laser Trapping
(2019-11-14)
Chiang, Wei-Yi
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Chen, Jim Jui-Kai
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Usman, Anwar
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Kudo, Tetsuhiro
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Xia, Kangwei
Femtosecond (fs) laser trapping of dielectric nanoparticles displays a unique trapping and directional ejection phenomenon, which is never observed in continuous-wave (cw) laser trapping. We studied the fs laser trapping and considered its dynamics and mechanism in terms of gathering, association, and ejection of nanoparticles. By tuning solution viscosity through adding ethylene glycol, the trapping behavior by fs and cw lasers are examined and compared with each other. The viscous solution slows down the diffusional and rotational movement of nanoparticles and increases the chance of nanoparticle assembly in the trapping site, which eventually leads to the novel ejection. We took advantage of fluorescence measurement to confirm the formation of the nanoparticle assembly during fs laser trapping. A red emission irregularly appeared in the fluorescence supports the transient assembly formation in the molecular level.
Optimal Design of a New Strain-Type Sensor for Cuff-Less Blood Pressure Measurement via Finite Element Modeling and Taguchi Method
(2019-11-15)
Tu, Tse-Yi
;
Chao, Paul C-P
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電機工程學系
;
電控工程研究所
;
Department of Electrical and Computer Engineering
A new cuff-less blood pressure (BP) sensor is designed and optimized in this paper. This BP sensor is in a shape of a circular disc of polymer enclosing an electrode. As the sensor is attached to the wrist artery, the dynamic bending of the sensor due to small artery pulsation induces variation in the electrode strain, and then, its resistance varies. With adequate amplification to sense resistance variation, the pulsation signals can be successfully obtained. With the measured pulsation representing well the blood volume pulsation (BVP), BP can be estimated next via the pulse wave velocity (PWV) theory. Effort is dedicated by this paper to optimize the sizes and geometry of the proposed sensor to maximize the electrode curvature change for largest measured signal-to-noise ratio (SNR) possible, which maximizes the accuracy of BP estimation. To this end, the optimization via the finite element modeling and the Taguchi method is carried out. In results, the optimal sizes in height/radius, fillet, hardness, and the electrode position of the polymer disc are successfully derived, which are in the height of 2 mm, the radius of 6mm, the distance between the planar electrode and the bottom surface of sensor being 1 mm, the hardness of the encapsulating polymer being 25 in shore A hardness, and the fillets at the bottom of the polymer disc being 1 mm in radii. BP is measured for 59 subjects. The resulted errors are 3.60 +/- 5.40 mmHg (mean difference +/- standard deviation) and 1.15 +/- 1.63 mmHg for SBP and DBP, respectively. The correlations are 0.8787 and 0.9648, demonstrating well the favorable performance of the developed sensor.
【自煮時代：宿舍廚房改造願景工作坊】（一學分）
(國立陽明大學, 2019-11-15)
陽明電子報編輯小組
樂生首次院外展，珍貴公衛史料重現陽明
(國立陽明大學, 2019-11-15)
陽明電子報編輯小組
經過半年多籌畫，並獲得許多陽明校友捐款支持，藝文中心2019壓軸強檔──【樂生在陽明：醫病、生活文物展】10月31日揭幕，這也是...
榮陽媒合會發表多項創新研發成果，深具產業化價值
(國立陽明大學, 2019-11-15)
陽明電子報編輯小組
陽明與臺北榮民總醫院11月12日共同舉辦第二屆「榮陽聯合研發成果發表媒合會」，展現12位教授、醫師及兩家育成廠商之最新研發成果...
【語言暨博雅通識活動日】～遊藝動靜之間
(國立陽明大學, 2019-11-15)
陽明電子報編輯小組
Enhancement of hydrogen evolution reaction by Pt nanopillar-array electrode in alkaline media and the effect of nanopillar length on the electrode efficiency
(2019-11-15)
Cheng, Hsyi-En
;
Li, Wen-Lung
;
Yang, Zu-Po
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光電系統研究所
;
Institute of Photonic System
Pt nanopillar-array 3D electrodes with nanopillar length of 150, 450 and 900 nm and nanopillar density of similar to 10(9) cm(-2) were fabricated. Their catalytic activity for hydrogen evolution reaction (HER) was evaluated by linear sweep voltammetry and electrochemical impedance spectroscopy. In comparison with straightly electrodeposited black Pt film and forged Pt sheet electrodes, the HER current density has been significantly improved by the nanopillar-array architecture. The overpotential of HER at current density of 10 mA cm(-2) at 26 degrees C is as low as 78 mV, lower than the black Pt film of 107 mV and the Pt sheet of 174 mV. The improvement of HER is ascribed to the low charge transfer resistance of the 3D electrode and the high desorption capability of hydrogen bubbles at the nanotips. Interestingly, the nanopillar-array 3D electrode has an optimal nanopillar length for HER. The mechanisms for the optimal nanopillar length were investigated here. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
【11/29與校長有約】
(國立陽明大學, 2019-11-15)
陽明電子報編輯小組
Simulation study of gated nanowire InAs/Si Hetero p channel TFET and effects of interface trap
(2019-11-15)
Joseph, H. Bijo
;
Singh, Sankalp Kumar
;
Hariharan, R. M.
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Tarauni, Yusuf
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Thiruvadigal, D. John
The impact of EOT (Equivalent Oxide Thickness) scaling, diameter scaling, and interface traps on the performance of gated InAs/Si Hetero pTFET (Tunneling field effect transistor) is investigated. EOT scaling improves SS (SubthresholdSwing) below the thermal limit and on current moderately. Diameter scaling decreases on current and marginally improves SS. The simulation study validates that the transfer characteristics of pTFET in sub-threshold region are completely dominated by thermionic emission of holes and TAT (Trap Assisted Tunneling). This in turn blocks SS to attain < 60 mV/dec. Furthermore, Si/Oxide interface traps minimize the electrostatic gate coupling with channel region additionally deteriorates SS. Interface trap density with different values denotes that sub 2.3k(B)T/q SS can only be realized for interface trap densities D-it < 1 x 10(11) cm(-2)eV(-1) at both InAs/Si and Si/Oxide. Hence this reaffirms the experimental data, that the prerequisite of D-it < 1 x 10(12) cm(-2)eV(-1) for InAs/Si nanowire p-TFET.
【年輕研究學者論文撰寫工作坊】
(國立陽明大學, 2019-11-15)
陽明電子報編輯小組
【生物醫學暨工程學院院級演講】～黃自強教授主講
(國立陽明大學, 2019-11-15)
陽明電子報編輯小組
【生醫領航方舟企業講座9】藥物開發評估與分析
(國立陽明大學, 2019-11-15)
陽明電子報編輯小組
「樂生文物展」延伸講座：科學博物館的藝術介入
(國立陽明大學, 2019-11-15)
鍾庭宜
;
陽明電子報編輯小組
藝文中心【樂生在陽明：醫病、生活文物展】開展後，相關的講座活動也陸續登場。第一場延伸講座，是由藝文中心與科技社會所、視覺文化所合辦的「展覽跨領域：科學博物館的藝術介入」，邀請到國立臺北藝術大學博物館研究所張婉真教授，來和大家分享藝術如何介入以自然科學為主的博物館，及其在展示方法與呈現上的策略。
【愛滋宣導與標語設計比賽】
(國立陽明大學, 2019-11-15)
陽明電子報編輯小組
A Piezoceramic Sensor for Detection of Focused Ultrasound-Induced Cavitation
(2019-11-15)
Chen, Jung-Chih
;
Chang, Hsin-Yun
;
Chen, Jiun-Jung
;
Chen, Gin-Shin
;
分子醫學與生物工程研究所
Acoustic cavitation plays a key role in blood-brain-barrier opening. Stable cavitation is required for safely transient barrier disruption when inertial cavitation may cause potentially undesirable damage to brain. To ensure the safety, an appropriate passive cavitation detector is needed to monitor cavitation activity during focused ultrasound treatment. The purpose of this study was to develop a passive cavitation detector with high sensitivity at the specific frequency used in blood-brain-barrier opening. The detector was designed with the assistance of pulse-echo response simulations, using the software PiezoCAD. The active transducer of the detector was constructed of two matching layers, a PZT-5A ceramic disk and the titanium backing. The detector was characterized via the pulse-echo measurements and a commercial hydrophone was used to determine the sensitivity of the developed detector. Cavitation experiments were also performed to validate the detector. The experimental results showed that the detector had the center frequency of 1.16 MHz with the bandwidth of 44.8% and its sensitivity was 2.87 V / MPa at 1.0 MHz. In cavitation experiments, 2-MHz focused ultrasound with the focal intensity of 58 W/cm(2) and 1461 W/cm(2) induced stable cavitation and inertial cavitation in free field, separately. The spectra of the ultrasound signals detected by the detector indicated the occurrence of peak voltages at the subharmonic frequency of 1 MHz and the increase in the level of wideband signals, reflecting stable cavitation and inertial cavitation, respectively. Based on the design guideline of this study, the passive cavitation detector can be developed dedicated for blood-brain-barrier opening.