Browsing by Issue Date, starting with "2019-12-02"

Now showing 1 - 20 of 6195

Y The Correlation of Central Serous Chorioretinopathy and Subsequent Cardiovascular Diseases of Different Types: A Population-Based Cohort Study
(2019-12-02)
Hsu, Hung-Jui
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Lee, Chia-Yi
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Chao, Shih-Chun
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Nien, Chan-Wei
;
Tzeng, Shih-Hao
The aim of the present study was to survey the relationship between central serous chorioretinopathy (CSC) and several cardiovascular diseases (CVDs) with different severities using the National Health Insurance Research Database. A retrospective cohort study was conducted. Subjects with CSC were enrolled according to the relevant diagnostic codes, and an age- and gender-matched population was used as the control group with a 1:4 ratio. The main outcome being considered was the development of CVD after CSC exposure. Cox proportional hazard regression was applied to calculate the adjusted hazard ratio (aHR) of CSC and CVD of different types. A total of 2865 patients that were diagnosed with CSC were enrolled in the study group, while another 11,460 non-CSC subjects were selected as the control group. There were 171 events of CVD which occurred in the study group, while another 557 cases were found in the control group. No significant differences were observed among the CVD cases between the study and control group, whether they had an acute or chronic form, according to the aHR. In the subgroup analysis, there was a significantly higher risk of CVD development in the male population aged from 40 to 59 years (aHR: 1.351, confidence interval (CI): 1.063-1.716), which was mainly due to the higher risk of mild CVD (aHR: 1.391, CI: 1.062-1.822). On the contrary, there was no significant difference in CVD development in any of the age subgroups of the female population. In conclusion, the existence of CSC is correlated with a higher rate of chronic CVD occurrence in the middle-aged male population.
Oxidative steam reforming of ethanol over MxLa2-xCe1.8Ru0.2O7-delta (M = Mg, Ca) catalysts: effect of alkaline earth metal substitution and support on stability and activity
(2019-12-02)
Hsieh, Ho-Chen
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Tsai, Ping-Wen
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Chang, Yuan-Chia
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Weng, Sheng-Feng
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Sheu, Hwo-Shuenn
Alkaline earth metal substitutions on the A-site of pyrochlore oxide MxLa2-xCe1.8Ru0.2O7-delta (M = Mg, Ca) were studied as catalyst materials for oxidative/autothermal steam reforming of ethanol (OSRE/ATR). The as-prepared oxides were synthesized by a combustion method and characterized using powder X-ray diffraction (PXRD), and X-ray photoelectron and absorption spectroscopy (XPS and XAS). PXRD Rietveld analysis and elemental analysis (ICP-AES) support the formation of a pyrochlore-type structure (space group Fd3m) with a distorted coordination environment. The substitution of Mg²⁺ and Ca²⁺ ions affects the oxidation states of Ce^4+/3+ and Ruⁿ⁺ ions and creates oxygen vacancies, which leads to enhanced catalytic activity and reduced ethylene selectivity. A long-term stability test showed optimized catalysts Mg0.3La1.7Ce1.8Ru0.2O7-delta and Ca0.2La1.8Ce1.8Ru0.2O7-delta with SH2 = 101(1)% and SH2 = 91(2)% under OSRE conditions. The initial operation temperatures were lower than that of the unsubstituted catalyst La2Ce1.8Ru0.2O7-delta. Catalysts supported on La2Zr2O7 showed stable OSRE/ATR performance and low carbon deposition compared to catalysts supported on Al2O3. We ascribe the enhanced activity to well-dispersed alkaline earth metal and Ru ions in a solid solution structure, synergistic effects of (Mg, Ca)²⁺/Ce^3+/4+/Ruⁿ⁺ ions, and a strong catalyst-support interaction that optimized the ethanol conversion and hydrogen production.
Evaluation of GPM-era Global Satellite Precipitation Products over Multiple Complex Terrain Regions
(2019-12-02)
Derin, Yagmur
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Anagnostou, Emmanouil
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Berne, Alexis
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Borga, Marco
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Boudevillain, Brice
The great success of the Tropical Rainfall Measuring Mission (TRMM) and its successor Global Precipitation Measurement (GPM) has accelerated the development of global high-resolution satellite-based precipitation products (SPP). However, the quantitative accuracy of SPPs has to be evaluated before using these datasets in water resource applications. This study evaluates the following GPM-era and TRMM-era SPPs based on two years (2014-2015) of reference daily precipitation data from rain gauge networks in ten mountainous regions: Integrated Multi-SatellitE Retrievals for GPM (IMERG, version 05B and version 06B), National Oceanic and Atmospheric Administration (NOAA)/Climate Prediction Center Morphing Method (CMORPH), Global Satellite Mapping of Precipitation (GSMaP), and Multi-Source Weighted-Ensemble Precipitation (MSWEP), which represents a global precipitation data-blending product. The evaluation is performed at daily and annual temporal scales, and at 0.1 deg grid resolution. It is shown that GSMaPV07 surpass the performance of IMERGV06B Final for almost all regions in terms of systematic and random error metrics. The new orographic rainfall classification in the GSMaPV07 algorithm is able to improve the detection of orographic rainfall, the rainfall amounts, and error metrics. Moreover, IMERGV05B showed significantly better performance, capturing the lighter and heavier precipitation values compared to IMERGV06B for almost all regions due to changes conducted to the morphing, where motion vectors are derived using total column water vapor for IMERGV06B.
Statistical Features and Expert Knowledge for Monitoring Operating Efficiency and Conditions of Wastewater Treatment Pumps
(2019-12-02)
Lin, Chang-Ming
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Lin, Sheng-Fuu
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電控工程研究所
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Institute of Electrical and Control Engineering
Wastewater treatment requires energy-intensive technology. The demand for industrial and residential wastewater treatment is increasing, and it has been widely accepted that low energy consumption and high operating efficiencies are essential to achieve high operating benefits in wastewater treatment plants (WWTPs). In this study, characteristic parameters of equipment operation were collected and subject to statistical analysis for trend observations in combination with expert knowledge to monitor equipment operating conditions. A methodology was developed to monitor and assess operating efficiencies of industrial equipment while not interfering with the existing operation. The proposed methodology was applied to monitor the pump efficiency in a WWTP. The results showed that the new methodology resulted in real-time acquisition of statistical operating data and enabled online detection of abnormal pump operation. The energy loss to low operating efficiencies of a malfunctioning pump was prevented, thereby allowing the pump to operate at high efficiency with an extended equipment life.
Mode Selection and Spectrum Allocation in Coexisting D2D and Cellular Networks with Cooperative Precoding
(2019-12-02)
Chan, Yu-Wei
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Chien, Feng-Tsun
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Yang, Chao-Tung
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
In this paper, we investigate the mode selection strategies for a new device-to-device (D2D) pair becoming active in a network with a number of existing D2D sensors or users coexisting with cellular users in a D2D-enabled heterogeneous network. Specifically, we propose two selection rules, the signal-to-interference-plus-noise-ratio (SINR)-based and the capacity-based, combined with two sets of different precoding schemes and discuss their impacts on the system under a variety of scenarios. While the cooperative block diagonalization (BD) among the cellular users combined with the zero-forcing (ZF) precoding among D2D users can eliminate interference observed at the new D2D receiving sensor, the maximum signal-to-leakage-and-noise-ratio (SLNR) precoding is often a preferred option due to low-complexity implementations and comparable performance. We note that the two selection rules, the SINR-based and the capacity-based, considered in this paper impact on the system differently, with interesting tradeoff from different perspectives. Finally, we provide insights by simulations into the best selection among the three modes depending on a variety of use cases in the network.
Chaotic Swimming of Phoretic Particles
(2019-12-03)
Hu, Wei-Fan
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Lin, Te-Sheng
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Rafai, Salima
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Misbah, Chaouqi
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應用數學系
The swimming of a rigid phoretic particle in an isotropic fluid is studied numerically as a function of the dimensionless solute emission rate (or Peclet number Pe). The particle sets into motion at a critical Pe. Whereas the particle trajectory is straight at a small enough Pe, it is found that it loses its stability at a critical Pe in favor of a meandering motion. When Pe is increased further, the particle meanders at a short scale but its trajectory wraps into a circle at a larger scale. Increasing even further, Pe causes the swimmer to escape momentarily the circular trajectory in favor of chaotic motion, which lasts for a certain time, before regaining a circular trajectory, and so on. The chaotic bursts become more and more frequent as Pe increases, until the trajectory becomes fully chaotic, via the intermittency scenario. The statistics of the trajectory is found to be of the run-and-tumble-like nature at a short enough time and of diffusive nature at a long time without any source of noise.
Long-term ambient hydrocarbons exposure and incidence of ischemic stroke
(2019-12-04)
Zhang, Han-Wei
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Kok, Victor C.
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Chuang, Shu-Chun
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Tseng, Chun-Hung
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Lin, Chin-Teng
Exposure to air pollutants is known to have adverse effects on human health; however, little is known about the association between hydrocarbons in air and an ischemic stroke (IS) event. We investigated whether long-term exposure to airborne hydrocarbons, including volatile organic compounds, increased IS risk. This retrospective cohort study included 283,666 people aged 40 years or older in Taiwan. Cox proportional hazards regression analysis was used to fit single- and multiple-pollutant models for two targeted pollutants, total hydrocarbons (THC) and nonmethane hydrocarbons (NMHC), and estimated the risk of IS. Before controlling for multiple pollutants, hazard ratios (HRs) of IS with 95% confidence intervals for the overall population were 2.69 (2.64-2.74) at 0.16-ppm increase in THC and 1.62 (1.59-1.66) at 0.11-ppm increase in NMHC. For the multiple-pollutant models controlling for PM2.5, the adjusted HR was 3.64 (3.56-3.72) for THC and 2.21 (2.16-2.26) for NMHC. Our findings suggest that long-term exposure to THC and NMHC may be a risk factor for IS development.
Defect induced ferromagnetic ordering in epitaxial Zn0.95Mn0.05O films on sapphire (0001)
(2019-12-04)
Liu, Wei-Rein
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Pao, Chih-Wen
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Yu, Doris Weijyun
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Chin, Yi-Ying
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Wu, Wen-Bin
We report the influence of Mn dopant on magnetic properties of Zn0.95Mn0.05O (ZMO)/Al2O3(0001) hetero-epitaxial systems grown by using pulsed-laser deposition. The room temperature (RT) intrinsic ferromagnetic (FM) ordering verified by superconducting quantum interference device magnetometer and x-ray magnetic circular dichroism spectrum of Mn L-2(,3) edges is ascribed to the substitutional Mn atoms in the Zn site of ZnO. Mn in ZMO has a tetrahedral local symmetry instead of the octahedral symmetry of MnO, after verifying the absence of the Mn-related impurities or clusters in ZMO epitaxial film by Mn K-edge and Zn K-edge x-ray absorption spectroscopy spectrum, as well as the analysis of long-range structural ordering on Renninger scan of forbidden (0005) reflection in x-ray diffraction, transmission electron microscopy and Raman spectrum. Comparison of x-ray absorption spectra of ZMO with those of ZnO epilayers at O K-, Zn K-, and L-3-edges indicates that the substitution of the Zn site with Mn enhances the charge-transfer (CT) transition and the presence of Zn vacancies (V-Zn) also dominate the photoluminescence (PL) spectrum, implying that the formation of numerous V-Zn defects plays an important role in activating FM interactions. The strong CT effect and the existence of high-density V-Zn suggest that the intrinsic RT FM ordering of insulating ZMO is a result of the formation of the bound magnetic polarons (BMPs) that interact with each other via intermediate magnetic impurities.
Large Collective Lamb Shift of Two Distant Superconducting Artificial Atoms
(2019-12-04)
Wen, P. Y.
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Lin, K. -T.
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Kockum, A. F.
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Suri, B.
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Ian, H.
Virtual photons can mediate interaction between atoms, resulting in an energy shift known as a collective Lamb shift. Observing the collective Lamb shift is challenging, since it can be obscured by radiative decay and direct atom-atom interactions. Here, we place two superconducting qubits in a transmission line terminated by a mirror, which suppresses decay. We measure a collective Lamb shift reaching 0.8% of the qubit transition frequency and twice the transition linewidth. We also show that the qubits can interact via the transmission line even if one of them does not decay into it.
Sp(4) gauge theories on the lattice: N-f=2 dynamical fundamental fermions
(2019-12-05)
Bennett, Ed
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Hong, Deog Ki
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Lee, Jong-Wan
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Lin, C. -J. David
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Lucini, Biagio
We perform lattice studies of the gauge theory with Sp(4) gauge group and two flavours of (Dirac) fundamental matter. The global SU(4) symmetry is spontaneously broken by the fermion condensate. The dynamical Wilson fermions in the lattice action introduce a mass that breaks the global symmetry also explicitly. The resulting pseudo-Nambu-Goldstone bosons describe the SU(4)/Sp(4) coset, and are relevant, in the context of physics beyond the Standard Model, for composite Higgs models. We discuss scale setting, continuum extrapolation and finite volume effects in the lattice theory. We study mesonic composite states, which span representations of the unbroken Sp(4) global symmetry, and we measure masses and decay constants of the (flavoured) spin-0 and spin-1 states accessible to the numerical treatment, as a function of the fermion mass. With help from the effective field theory treatment of such mesons, we perform a first extrapolation towards the massless limit. We assess our results by critically comparing to the literature on other models and to the quenched results, and we conclude by outlining future avenues for further exploration. The results of our spectroscopic analysis provide new input data for future phenomenological studies in the contexts of composite Higgs models, and of dark matter models with a strongly coupled dynamical origin.
Comparison of a new mass-concentration, chain-reaction model with the population-balance model for early- and late-stage aggregation of shattered graphene oxide nanoparticles
(2019-12-05)
Babakhani, Peyman
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Bridge, Jonathan
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Phenrat, Tanapon
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Fagerlund, Fritjof
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Doong, Ruey-an
Aggregation as an essential mechanism impacting nanoparticle (NP) functionality, fate, and transport in the environment is currently modelled using population-balance equation (PBE) models which are computationally expensive when combined with other continuum-scale reactive transport models. We propose a new simple mass-concentration-based, chain-reaction modelling (CRM) framework to alleviate computational expenses of PBE and potentially to facilitate combination with other fate, transport, and reaction models. Model performance is compared with analytical PBE solution and a standard numerical PBE technique (fixed pivot, FP) by fitting against experimental data (i.e., hydrodynamic diameter and derived count rate of dynamic light scattering used as a representative of mass concentration) for early- and late-stage, aggregation of shattered graphene oxide (SGO) NP across a broad range of solution chemistries. In general, the CRM approach demonstrates a better match with the experimental data with a mean Nash-Sutcliffe model efficiency (NSE) coefficient of 0.345 than the FP model with a mean NSE of 0.29. Comparing model parameters (aggregation rate constant and fractal dimension) obtained from fitting CRM and FP to the experimental data, similar trends or ranges are obtained between the two approaches. Computationally, the modified CRM is an order-of-magnitude faster than the FP technique, suggesting that it can be a promising modelling framework for efficient and accurate modelling of NP aggregation. However, in the scope of this study, reaction rate coefficients of the CRM have been linked to collision frequencies based on simplified and empirical relationships which need improvement in future studies.
Spatiotemporal Dynamics of Laser-Induced Molecular Crystal Precursors Visualized by Particle Image Diffusometry
(2019-12-05)
Hanasaki, Itsuo
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Okano, Kazuki
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Yoshikawa, Hiroshi Y.
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Sugiyama, Teruki
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交大名義發表
We have succeeded in label-free visualization of spatiotemporal dynamics of laser-induced crystal precursors in aqueous solutions. The tracking-free evaluation of the diffusion-coefficient field for the observation domain with tens of micrometers on a side from microscopy movie data is realized by particle image diffusometry (PID). PID revealed the time fluctuation of coverage composition with the nonuniform space distribution of diffusion coefficients by the prenucleation clusters. Furthermore, the results indicate the existence of a loose aggregation domain of prenucleation clusters where the order of viscosity corresponds to that of honey.
Palladium-Catalyzed Cascade Arylation of Vinylogous Esters Enabled by Tris(1-adamantyl)phosphine
(2019-12-06)
Yang, Yi-Chi
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Lin, Yi-Ching
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Wu, Yen-Ku
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應用化學系
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Department of Applied Chemistry
Described is a method for the transformation of a cyclic vinylogous ester to the corresponding polyarylated product. We found a catalytic system comprising palladium diacetate and tris(1-adamantyl)phosphine is quite effective in promoting a set of controlled cascade arylations. As a result, a range of novel (hetero)aryl-containing scaffolds was synthesized with a high level of efficiency.
Anisotropic superconductivity induced by periodic multiferroic domain patterns
(2019-12-06)
Huang, Yen-Lin
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Huang, Bo-Chao
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Wang, Yan-Ting
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Xue, Fei
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Lin, Jheng-Cyuan
The competition between order parameters, such as ferroelectricity, ferromagnetism, and superconductivity, is one of the most fascinating topics in condensed matter physics. Here, we report intriguing anisotropic superconductivity in YBa2Cu3O7-x films induced by a multiferroic, BiFeO3, with periodic domain patterns. The anisotropic superconductivity was investigated by transport measurements and supported by phase-field simulations, and then the detailed local electronic structures were revealed by cross-sectional scanning tunneling microscopy. We found that the oxygen redistribution in YBa2Cu3O7-x modulated by the ferroelectric polarization in BiFeO3 was the key mechanism driving this anisotropic superconductivity. The presented heteroarchitecture of a high-temperature superconductor and a domain-engineered multiferroic provides a new approach to tune superconductivity and offers potential advantages for the design of future multifunctional devices.
Selective catalytic oxidation of benzene to phenol by a vanadium oxide nanorod (V-nr) catalyst in CH3CN using H2O2(aq) and pyrazine-2-carboxylic acid (PCA)
(2019-12-07)
Wanna, Wondemagegn Hailemichael
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Janmanchi, Damodar
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Thiyagarajan, Natarajan
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Ramu, Ravirala
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Tsai, Yi-Fang
Vanadium based catalysts are known to be highly efficient for oxidation reactions using O-2 and/or H2O2. In this study, we developed a vanadium catalyst that can be prepared by a reaction of VCl3 in acetonitrile with the addition of 35% hydrogen peroxide (H2O2). The catalyst was further characterized by a variety of methods including V-51 NMR, XRD, XPS, XAS, EA, ICP-AES, BET, SEM and TEM. Based on the results obtained, the catalyst was identified as a vanadium oxide material (V-nr) with the morphology and shape of a nanorod with dimensions of similar to 40 nm x 450 nm (width x length). The porosity of a material can be essential for small molecule activation on a heterogeneous surface. This material exhibits exceptional catalytic performance for the selective oxidation of benzene to phenol (PhOH) at room temperature using H2O2 as an oxidant in acetonitrile. The addition of pyrazine-2-carboxylic acid (PCA) as a co-catalyst can efficiently enhance the catalytic activity with a percentage selectivity of 87-99% phenol, producing p-benzoquinone (p-BQ) as a minor product. With the deployment of (H2O2)-O-18, we observed the product phenol to be highly enriched by O-18, indicating that the hydroperoxovanadium intermediate is essential for its catalytic conversion. Together with its high NIH shift ratio (80% deuterium remained) observed with the mechanistic probe of 4-[H-2(0,1)] toluene, the results suggested that the catalytic oxidation reaction mediated by Vnr may involve metal based oxygenated intermediates for its highly selective catalytic oxidation of benzene to phenol.
減肥照過來！人一天到底要吃多少？
(2019-12-08)
陳千柔
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Department of Communication and Technology
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傳播與科技學系
【You are what you eat】專題

健康必須從飲食做起，但究竟人的一天需要攝取多少熱量呢？哪些物質的攝取會提高罹患心血管疾病的風險？
對戰科技冷漠　體驗經濟是什麼？
(2019-12-08)
王會瑄
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Department of Communication and Technology
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傳播與科技學系
【滑世代的體驗經濟】專題

在科技產品的不斷迭代之下，人與人的直接接觸已不再是學習、娛樂甚至社交活動的必要條件。在此同時，體驗經濟卻以一種看似對立，而又相輔相成的微妙關係崛起且持續發燒中。
停頓流浪貓生命旅途之中
(2019-12-08)
曾弘碩
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Department of Communication and Technology
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傳播與科技學系
【那些貓兒與人類】專題

隨著養貓人士與日俱增，對於貓咪的認知，不能侷限在網路上的影音，而是關懷貓咪的生命歷程，以及照顧機制的問題。
地方創生讓青年提升台灣「鄉村力」
(2019-12-08)
林怡恩
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Department of Communication and Technology
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傳播與科技學系
【地方創生：年輕人，回家吧】專題

政府將2019年訂定為地方創生元年，大力推動青年返鄉工作。希望藉此為鄉下村落創造新生機，也為台灣鄉村人口問題找到舒緩出口。
總編的話
(2019-12-08)
陳炘瑜
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Department of Communication and Technology
;
傳播與科技學系
本期為喀報327期，共計11篇文章，包含十篇文化現象、一篇社會議題。本篇頭題為陳姝芸的〈用數據看移工在台現況〉，探討被大眾忽視的台灣移工權益問題。本期專題題材多元，以時下熱門話題撰寫獨特的見解，或介紹鮮為人知的新知識，讓喀報的內容煥然一新，值得深讀。