Browsing by Issue Date, starting with "2015-02-12"

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Structural Evolution of Crystalline Conjugated Polymer/Fullerene Domains from Solution to the Solid State in the Presence and Absence of an Additive
(2015-02-12)
Su, Yu-Wei
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Liu, Chih-Ming
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Jiang, Jian-Ming
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Tsao, Cheng-Si
;
Cha, Hou-Chin
The power conversion efficiencies of polymer/fullerene solar cells are critically dependent on the nanometer-scale morphologies of their active layers, which are typically processed from solution. Using synchrotron wide- and small-angle X-ray scattering, we have elucidated the intricate mechanism of the structural transitions from solutions to solid films of the crystalline polymer poly[bis(dodecyl)thiophene-thieno[3,4-c]pyrrole-4,6-dione] (PBTTPD) and [6,6]-phenyl-C-71-butyric acid methyl ester (PC71BM), including the effect of the solvent additive 1,6-diiodohexane (DIH). We found that the local assembly of rigid-rod PBTTPD segments that formed in solution instantly and then relaxed within several hundred seconds upon cooling to room temperature from 90 degrees C could re-emerge and develop into seeds for subsequent crystallization of the polymer in the solid films. At room temperature (25 degrees C), the presence of DIH in chlorobenzene slightly enhanced the formation of local assembly PBTTPD segments in the supersaturated PBTTPD in PBTTPD/PC71BM blend solution. Two cases of films were subsequently developed from these blend solutions with drop-casted and spin-coated methods. For spin-coated thin films (90 nm thick), which evolve quickly, polymers crystallinity and the fullerene packing in the solid-state thin films were enhanced in the case of involving DIH. Regarding the effect of DIH for processing the drop-casted thick films (2.5 mu m thick), which evolve slowly, DIH has no observable effect on PBTTPD/PC71BM structure. Our results provide some understanding of the mechanism behind the structural development of polymer/fullerene blends upon their transitions from solution to the solid state, as well as the key functions of the additive.
Chitosan-PEG Hydrogel with Sol-Gel Transition Triggerable by Multiple External Stimuli
(2015-02-12)
Tsao, Ching Ting
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Hsiao, Meng Hsuan
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Zhang, Mengying Y.
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Levengood, Sheeny Lan
;
Zhang, Miqin
Smart hydrogels play an increasingly important role in biomedical applications, since materials that are both biocompatible and multi-stimuli-responsive are highly desirable. A simple, organic solvent-free method is presented to synthesize a biocompatible hydrogel that undergoes a sol-gel transition in response to multiple stimuli. Methoxy-poly(ethylene glycol) (mPEG) is modified into carboxylic-acid-terminated-methoxy-poly(ethylene glycol) (mPEG-acid), which is then grafted onto chitosan via amide linkages yielding mPEG-g-chitosan. Grafting of mPEG onto hydrophobic chitosan imparts hydrophilic properties to the resultant polymer. The mPEG-g-chitosan gel exhibits a controllable multi-stimuli-responsive property. The balance between hydrophilicity and hydrophobicity is believed to confer mPEG-g-chitosan with stimuli-responsive behavior. The effect of salt concentration, solute concentration, temperature, and pH on the sol-gel transition of mPEG-g-chitosan is evaluated and the underlying mechanisms of mPEG-g-chitosan polymer packing and gelation property is discussed.
Direct kinetic measurement of the reaction of the simplest Criegee intermediate with water vapor
(2015-02-13)
Chao, Wen
;
Hsieh, Jun-Ting
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Chang, Chun-Hung
;
Lin, Jim Jr-Min
;
應用化學系
Carbonyl oxides, or Criegee intermediates, are important transient species formed in the reactions of unsaturated hydrocarbons with ozone. Although direct detection of Criegee intermediates has recently been realized, the main atmospheric sink of Criegee intermediates remains unclear. We report ultraviolet absorption spectroscopic measurements of the lifetime of the simplest Criegee intermediate, CH2OO, at various relative humidity levels up to 85% at 298 kelvin. An extremely fast decay rate of CH2OO was observed at high humidity. The observed quadratic dependence of the decay rate on water concentration implied a predominant reaction with water dimer. On the basis of the water dimer equilibrium constant, the effective rate coefficient of the CH2OO + (H2O)(2) reaction was determined to be 6.5 (+/-0.8) x 10(-12) cubic centimeters per second. This work would help modelers to better constrain the atmospheric concentrations of CH2OO.
Progressive sharing of multiple images with sensitivity-controlled decoding
(2015-02-14)
Chang, Sheng-Yu
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Lee, Suiang-Shyan
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Yeh, Tzu-Min
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Chen, Lee Shu-Teng
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Lin, Ja-Chen
Secure sharing of digital images is becoming an important issue. Consequently, many schemes for ensuring image sharing security have been proposed. However, existing approaches focus on the sharing of a single image, rather than multiple images. We propose three kinds of sharing methods that progressively reveal n given secret images according to the sensitivity level of each image. Method 1 divides each secret image into n parts and then combines and hides the parts of the images to get n steganographic (stego) JPEG codes of equal importance. Method 2 is similar; however, it allocates different stego JPEG codes of different 'weights' to indicate their strength. Method 3 first applies traditional threshold-sharing to the n secret images, then progressively shares k keys, and finally combines the two sharing results to get n stego JPEG codes. In the recovery phase, various parameters are compared to a pre-specified low/middle/high (L/M/H) threshold and, according to the respective method, determine whether or not secret images are reconstructed and the quality of the images reconstructed. The results of experiments conducted verify the efficacy of our methods.
An optimum approach of profit analysis on the machine repair system with heterogeneous repairmen
(2015-02-15)
Ke, Jau-Chuan
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Liu, Tzu-Hsin
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Wu, Chia-Huang
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工業工程與管理學系
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Department of Industrial Engineering and Management
We consider a machine repair problem with queue-dependent heterogeneous repairmen. The stationary probability distribution of the number of failed machines in the system is derived. A profit model is developed to determine the optimal values of threshold to assign/add one more repairman for increasing the total service rate where the service rate is assumed adjustable. The probabilistic global search Lausanne (PGSL) method is employed to find an initial trial solution. Based on this initial solution, a direct search method is applied to obtain the optimal values of the threshold and, then, the Quasi-Newton method is implemented to adjust the corresponding service rates. Some numerical experiments are performed to justify the efficiency of the optimum approach. (C) 2015 Elsevier Inc. All rights reserved.
Nanoindentation pop-in effects of Bi2Te3 thermoelectric thin films
(2015-02-15)
Jian, Sheng-Rui
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Tasi, Cheng-Hsun
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Huang, Shiau-Yuan
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Luo, Chih-Wei
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電子物理學系
The structural, surface morphological and nanomechanical characteristics of Bi2Te3 thin films are investigated by means of X-ray diffraction (XRD), atomic force microscopy (AFM) and nanoindentation techniques. The Bi2Te3 thin films are deposited on c-plane sapphire substrates using pulsed laser deposition (PLD). The XRD result showed that Bi2Te3 thin film had a c-axis preferred orientation and a smoother surface feature from AFM observation. Nanoindentation results exhibit the discontinuities (so-called multiple "pop-ins" event) in the loading segments of the load-displacement curves, indicative of the deformation behavior in the hexagonal-structured Bi2Te3 thin film is the nucleation and propagation of dislocations. Based on this scenario, an energetic estimation of nanoindentation-induced dislocation resulted from pop-in effects is made. Furthermore, the hardness and Young\'s modulus of Bi2Te3 thin films were measured by a Berkovich nanoindenter operated with the continuous contact stiffness measurements (CSM) mode. The obtained values of the hardness and Young\'s modulus are 5.7 +/- 0.8 GPa and 158.6 +/- 6.2 GPa, respectively. (C) 2014 Elsevier B.V. All rights reserved.
Sensitivity enhancement of photothermal microscopy with radially segmented balanced detection
(2015-02-15)
Miyazaki, Jun
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Tsurui, Hiromichi
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Kawasumi, Koshi
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Kobayashi, Takayoshi
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電子物理學系
A novel detection method is proposed for highly sensitive photothermal microscopic imaging. This method is based on the characteristics of an angular-dependent photothermal signal; it improves signal intensity by up to two times and rejects the intensity noise of the probe beam. The subdiffraction resolution photothermal imaging of mouse skin melanoma is demonstrated using a laser diode-based photothermal microscopy system to evaluate this method. We confirm that the signal intensity is enhanced 1.7 times compared with the conventional detection method. Moreover, the intensity noise of the laser diode used for the probe beam is effectively reduced by approximately 31 dB, even for a sample with non-uniformity of the refractive index and stationary absorption. This method is implemented by means of a commonly used balanced detector and is thus potentially useful for high-speed imaging. (C) 2015 Optical Society of America
Robotics-assisted mass spectrometry assay platform enabled by open-source electronics
(2015-02-15)
Chiu, Shih-Hao
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Urban, Pawel L.
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應用化學系
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應用化學系分子科學碩博班
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Department of Applied Chemistry
Mass spectrometry (MS) is an important analytical technique with numerous applications in clinical analysis, biochemistry, environmental analysis, geology and physics. Its success builds on the ability of MS to determine molecular weights of analytes, and elucidate their structures. However, sample handling prior to MS requires a lot of attention and labor. In this work we were aiming to automate processing samples for MS so that analyses could be conducted without much supervision of experienced analysts. The goal of this study was to develop a robotics and information technology-oriented platform that could control the whole analysis process including sample delivery, reaction-based assay, data acquisition, and interaction with the analyst. The proposed platform incorporates a robotic arm for handling sample vials delivered to the laboratory, and several auxiliary devices which facilitate and secure the analysis process. They include: multi-relay board, infrared sensors, photo-interrupters, gyroscopes, force sensors, fingerprint scanner, barcode scanner, touch screen panel, and internet interface. The control of all the building blocks is achieved through implementation of open-source electronics (Arduino), and enabled by custom-written programs in C language. The advantages of the proposed system include: low cost, simplicity, small size, as well as facile automation of sample delivery and processing without the intervention of the analyst. It is envisaged that this simple robotic system may be the forerunner of automated laboratories dedicated to mass spectrometric analysis of biological samples. (C) 2014 Elsevier B.V. All rights reserved.
Stable passive optical clock generation in SOA-based fiber lasers
(2015-02-15)
Wang, Jing-Yun
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Lin, Kuei-Huei
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Chen, Hou-Ren
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光電工程學系
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Department of Photonics
Stable optical pulse trains are obtained from 1.3-mu m and 1.5-mu m semiconductor optical amplifier (SOA)-based fiber lasers using passive optical technology. The waveforms depend on SOA currents, and the repetition rates can be tuned by varying the relative length of sub-cavities. The output pulse trains of these SOA-based fiber lasers are stable against intracavity polarization adjustment and environmental perturbation. The optical clock generation is explained in terms of mode competition, self-synchronization, and SOA saturation. Without resorting to any active modulation circuits or devices, the technology used here is simple and may find various applications in the future. (C) 2015 Optical Society of America
Interfacial reactions between Cu and SnAgCu solder doped with minor Ni
(2015-02-15)
Cheng, Hsi-Kuei
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Huang, Chin-Wen
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Lee, Hsuan
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Wang, Ying-Lang
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Liu, Tzeng-Feng
The interfacial reactions between Cu and SnAgCu-based solders were investigated. Two types of SnAgCu-based solders were used, one was Sn-1.0Ag-0.5Cu (SAC105) and the other was Sn-1.2Ag-0.5Cu-0.05Ni (LF35), where the composition was in wt.%. The addition of Ni in the SnAgCu-based solder was found to have significant effects on the morphological evolution and growth of the Cu6Sn5 and Cu3Sn phases formed at the solder/Cu interfaces. At the Ni-added LF35/Cu interface after liquid/solid reaction at 260 degrees C,the Cu6Sn5 phase presented a microstructure with a much smaller grain size. During subsequent solid/solid reaction at 150 and 200 degrees C, the growth of the Cu6Sn5 phase was significantly enhanced at the LF35/Cu interface but that of the Cu3Sn phase was inhibited. A potential mechanism was proposed to explain the effects of Ni addition on the solder/Cu interfacial reactions. (C) 2014 Elsevier B. V. All rights reserved.
Extended depth-of-focus 3D micro integral imaging display using a bifocal liquid crystal lens
(2015-02-15)
Shen, Xin
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Wang, Yu-Jen
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Chen, Hung-Shan
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Xiao, Xiao
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Lin, Yi-Hsin
We present a three dimensional (3D) micro integral imaging display system with extended depth of focus by using a polarized bifocal liquid crystal lens. This lens and other optical components are combined as the relay optical element. The focal length of the relay optical element can be controlled to project an elemental image array in multiple positions with various lenslet image planes, by applying different voltages to the liquid crystal lens. The depth of focus of the proposed system can therefore be extended. The feasibility of our proposed system is experimentally demonstrated. In our experiments, the depth of focus of the display system is extended from 3.82 to 109.43 mm. (C) 2015 Optical Society of America
House selection via the internet by considering homebuyers' risk attitudes with S-shaped utility functions
(2015-02-16)
Ho, Hui-Ping
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Chang, Ching-Ter
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Ku, Cheng-Yuan
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
The widespread use of the Internet has significantly changed the behavior of homebuyers. Using online real estate agents, homebuyers can rapidly find some modern houses that meet their needs; however, most current online housing systems provide limit features. In particular, existing systems fail to consider homebuyers\' housing goals and risk attitudes. To increase effectiveness, online real estate agents should provide an efficient matching mechanism, personalized service and house ranking with the aim of increasing both buyers\' satisfaction and deal rate. An efficient online real estate agent should provide an easy way for homebuyers to find (rank) a suitable house (alternatives) with consideration of their different housing philosophies and risk attitudes. In order to comprehend these ambiguous housing goals and risk attitudes, it is also indispensable to determine a satisfaction level for each fuzzy goal and constraint. In this study, we propose fuzzy goal programming with an S-shaped utility function as a decision aid to help homebuyers in choosing their preferred house via the Internet in an easy way. With the use of a decision aid, homebuyers can specify their housing goals and constraints with different priority levels and thresholds as a matching mechanism for a fuzzy search, while the matching mechanism can be translated into a standard query language for a regular relational database. Moreover, a laboratory experiment is conducted on a real case to demonstrate the effectiveness of the proposed approach. The results indicate that the proposed method provides better customer satisfaction than manual systems in housing selection service. (C) 2014 Elsevier B.V. All rights reserved.
由單一計時器提供自動重傳請求事件觸發與管理的系統及其方法
(2015-02-16)
蕭旭峰
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曾冠儒
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李宗南
一種由單一計時器提供自動重傳請求事件觸發與管理的系統及其方法，整合自動重傳請求多種類型的計時器，透過自動重傳請求計時器串列中計時器節點的資料結構，得以使用單一計時器進行管理，藉此可以達成便於控制與管理全球互通微波存取協議中計時器的技術功效。 An event trigger and management system for providing automatic repeat requests by single timer and a method thereof are provided. Various type timers for providing automatic repeat requests are integrated into a single timer. Through a data structure of timer node of automatic repeat request serial, automatic repeat requests can be managed only by a single timer. Therefore, the efficiency of controlling and managing timers of worldwide interoperability for microwave access protocol may be achieved.
Synthesis and Isolation of an Acyclic Tridentate Bis(pyridine)carbodicarbene and Studies on Its Structural Implications and Reactivities
(2015-02-16)
Hsu, Yu-Chen
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Shen, Jiun-Shian
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Lin, Bo-Chao
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Chen, Wen-Ching
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Chan, Yi-Tsu
The simple synthetic development of acyclic pincer bis(pyridine)carbodicarbene is depicted herein. Presented is the first isolated structural pincer carbodicarbene with a C-C-C angle of 143 degrees, larger than the monodentate framework. More importantly, theoretical analysis showed that this carbodicarbene embodies a more allene-like character. Palladium complexes supported by this pincer ligand are active catalysts for Heck-Mizoroki and Suzuki-Miyaura coupling reactions.
用於金屬有機化學氣相沉積的真空壓力控制裝置
(2015-02-16)
李安謙
;
湯毓哲
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郭子瑋
本發明係有關於一種用於金屬有機化學氣相沉積的真空壓力控制裝置，包括：一真空腔體；一氣體源，係提供氣體給該真空腔體；一真空閥門，係調節該真空腔體之真空壓力；一真空幫浦，係透過該真空閥門抽吸該真空腔體內之氣體；一真空壓力計，係量測該真空腔體之真空壓力；以及一真空閥門控制器，係根據該真空壓力計調整該真空閥門。 The invention relates to a vacuum pressure control device for MOCVD, which comprise: a vacuum chamber, a gas source for providing gas to the vacuum chamber, a vacuum valve for adjusting the vacuum pressure of the vacuum chamber, a vacuum pump for aspirating the gas inside the vacuum chamber through the vacuum valve, a vacuum pressure gauge for measuring the vacuum pressure of the vacuum chamber, and a vacuum valve controller for adjusting the vacuum valve according to the vacuum pressure gauge.
Two-stage flow shop scheduling with dedicated machines
(2015-02-16)
Lin, Bertrand M. T.
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
This study is concerned with the manufacturing model that has a common machine at stage one and two parallel dedicated machines at stage two. All jobs need to be processed on the stage-one common machine. After the stage-one processing, the jobs of type 1 (type 2) will route to the first (second) dedicated machine at stage two. We first elaborate several published works on makespan minimisation which are not known to other streams of recent works. While the minimisation of maximum lateness is strongly NP-hard, we develop a linear-time algorithm to solve the case where two sequences of the two job types are given a priori.
Electrical connecting element having nano-twinned copper, method of fabricating the same, and electrical connecting structure comprising the same
(2015-02-17)
Chen Chih
;
Chiu Wei-Lan
An electrical connecting element, a method of fabricating the same, and an electrical connecting structure comprising the same are disclosed. The method of fabricating the electrical connecting structure having twinned copper of the present invention comprises steps of: (A) providing a first substrate; (B) forming a nano-twinned copper layer on part of a surface of the first substrate; (C) forming a solder on the nano-twinned copper layer of the first substrate; and (D) reflowing the nano-twinned Cu layer and solder to produce a solder joint, wherein at least part of the solder reacts with the nano-twinned copper layer to produce an intermetallic compound (IMC) layer which comprises a Cu3Sn layer, This invention reduces the voids formation in the interface between the intermetallic compound and the solder, and then enhances the reliability of solder joints.
Detection of Staphylococcus aureus by Functional Gold Nanoparticle-Based Affinity Surface-Assisted Laser Desorption/Ionization Mass Spectrometry
(2015-02-17)
Lai, Hong-Zheng
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Wang, Sin-Ge
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Wu, Ching-Yi
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Chen, Yu-Chie
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應用化學系
Staphylococcus aureus is one of the common pathogenic bacteria responsible for bacterial infectious diseases and food poisoning. This study presents an analytical method based on the affinity nanoprobe-based mass spectrometry that enables detection of S. aureus in aqueous samples. A peptide aptamer DVFLGDVFLGDEC (DD) that can recognize S. aureus and methicillin-resistant S. aureus (MRSA) was used as the reducing agent and protective group to generate DD-immobilized gold nanoparticles (AuNPs@DD) from one-pot reactions. The thiol group from cysteine in the peptide aptamer, i.e., DD, can interact with gold ions to generate DD-immobilized AuNPs in an alkaline solution. The generated AuNPs@DD has an absorption maximum at similar to 518 nm. The average particle size is 7.6 +/- 1.2 nm. Furthermore, the generated AuNPs@DD can selectively bind with S. aureus and MRSA. The conjugates of the target bacteria with AuNPs were directly analyzed by surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). The gold ions generated from the AuNPs@DD anchored on the target bacteria were monitored. Gold ions (m/z 197 and 394) were only generated from the conjugates of the target bacterium-AuNP@DD in the SALDI process. Thus, the gold ions could be used as the indicators for the presence of the target bacteria. The detection limit of S. aureus using this method is in the order of a few tens of cells. The low detection limit is due to the ease of generation of gold cluster ion derived from AuNPs under irradiation with a 355 nm laser beam. Apple juice mixed with S. aureus was used as the sample to demonstrate the suitability of the method for real-world application. Because of its low detection limit, this approach can potentially be used to screen the presence of S. aureus in complex samples.
Control strategies for departure process delays at airport passenger terminals
(2015-02-17)
Hsu, Chaug-Ing
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Chao, Ching-Cheng
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Hsu, Nai-Wen
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運輸與物流管理系註：原交通所+運管所
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Department of Transportation and Logistics Management
This paper explores the characteristics of process delays at airport passenger terminals and establishes a queuing model for both passengers and baggage served by different connecting type facilities. The impact of delay propagation on other processes and flights is investigated using an analytical approach. In addition, the extra costs incurred on passengers, process operators, and airlines are examined using the delay cost functions. To reduce the impact of process delays, various delay-controlled strategies are proposed, such as setting scheduled times for completion of a process, increasing the number of service counters, and priority service for emergent flights. Taoyuan International Airport in Taiwan is used as a case study when facing special events. Results showed that the model can effectively and efficiently estimate delay propagation and its costs. In addition, processes that are not consecutive allow more buffer time between different operations, which helps ease propagation of delays caused by previous services.
On-chip electronic device and method for manufacturing the same
(2015-02-17)
Cheng Yu-Ting
;
Chao Tzu-Yuan
;
Chen Kuan-Ming
;
Hsu Hsin-Fu
The present invention relates to an on-chip electronic device and a method for manufacturing the same. The on-chip electronic device according to the present invention comprises a substrate, a porous layer, a plurality of magnetic bodies, and an electronic member layer. The porous layer is disposed on the substrate and has a plurality of voids; each of the plurality of magnetic bodies is disposed in the plurality of voids, respectively; and the electronic member layer is disposed on one side of the porous layer, such as upper side of or lower sider of the porous layer. Because the plurality of magnetic bodies is used as the core of the inductance, the inductance is increased effectively and the area of the on-chip electronic device is reduced. Besides the manufacturing method according to the present invention is simple and compatible with the current CMOS process, the manufacturing cost can be lowered.