2006.6
About Instruments Today No. 152
Applications of the Transmission X-Ray Microscope [ 下載 PDF ]
Gung-Chian Yin, Fu-Rong Chen, Keng S. Liang
The transmission X-ray microscope developed at NSRRC has characteristic functions of large penetration depth (< 100 mm), high resolution (25–60 nm), tunable energy-range (8–11 keV), and the capability of 3D tomography. Having these functionalities, this microscope is also capable of performing image modes resemble to those of optical microscope, such as, the absorption contrast, phase contrast, and the dark field imaging. In this paper, briefs of the principles and the applications of the X-ray microscope are presented.
Fabrication and Application of Molecularly Imprinted Polymer-Based Sensors [ 下載 PDF ]
Shih-hui Lee, Ruey-an Doong
Biosensors have been used extensively in diagnostics, medicine, environmental monitoring and food processes. Various biological molecules such as antibodies and enzymes, which are capable of recognizing a specific target molecule, can be used as the biorecognition elements in biosensors. However, the cost and inactivation under harsh environments such as high pH and high temperature hamper the use of macrobiomolecules. In addition, it is difficult to find suitable enzymes or receptors that are able to recognize certain target analytes. Molecularly imprinted polymers (MIPs) are highly cross-linked synthetic polymers, which can be obtained from the innovative technique of molecular imprinting technique. MIPs have many advantages, including stability under harsh environment, the simplicity of their preparation and can be used as alternatives for enzymes and antibodies. In recent years, MIPs have received much attention on applications to sensor design, the separation of drugs and chiral compounds and catalysis. In this text, the principles of MIPs preparation will be introduced. The MIP-based sensors can be classified as optical sensors, electrochemical sensors and mass-sensitive sensors. In addition, the fabrication and application of molecularly imprinted polymer-based sensors will be presented and discussed.
Electron Backscatter Diffraction Technique in SEM [ 下載 PDF ]
Hou-Guang Chen, Li Chang
The article introduces the principle, experimental procedure and applications of electron backscatter diffraction (EBSD) technique for crystallographic analysis. The formation of EBSD pattern and automatic pattern identification with indexing is described. The effect of instrument parameters and calibration on the experimental results is also presented. Using a field emission SEM with EBSD, the crystallographic structure and orientation in a specific area on a sample can be easily characterized in sub-micrometer scale. In addition to application for metallographic analysis of structural metal materials, EBSD has also been used for analysis of microelectronic devices in semiconductor industry. Practical examples using EBSD for materials analysis are demonstrated for poly-Si and Ni3Al.
On the Design Tips for Undersea Instrument Systems [ 下載 PDF ]
Chau-Chang Wang, Min-Wei Hung, Po-Chi Chen
The design of marine or underwater instrument takes almost totally different challenge than its counter parts in the air. Actually the environment is much more harsh on the survive of the instrument. The crucial factors need to be taken into account include power system, water resistance, anti-corrosion, signal connection, data storage and etc. It is the goal of this article to briefly introduce and explain the importance of these factors through the integration of two underwater systems.
An Introduction to National Instrumental Information System [ 下載 PDF ]
Jiann-Yeu Wang
The National Instrumental Information System is a complete database system based on survey of most government agencies, medical centers, research centers, and colleges. It provides the information of valuable instruments in Taiwan, which may be used for research and analysis purposes. Agencies or enterprises could take advantages of this public system so that the instrumental resources of the country can be utilized more evenly and efficiently. This article gives an introduction of the brief history of the system, and shows how to use the database along with an analysis of current instrumental data.
Heat Transfer Characteristics of Nanofluids and Its Application in a Freezing Chucker [ 下載 PDF ]
Rong-Yuan Jou
Nanofluidics is often defined as the study and application of fluid flow in and around nanosized objects. In general, thermal conductivity of solid phase particles are larger than liquids. Hence, by properly dispersing nanoparticles into matrix fluid, the mixtures prevail over normal fluid for its superior heat transfer performance. In this study, comprehensive researching topics and industrial applications regarding to nanofluids are briefly introduced. Then, specifically applications of nanofluids in heat transfer system are demonstrated in more detail. The main objectives of the study are to identify important parameters for microscale liquid flows and nanoparticle suspensions, to find a physically sound way to analyze the new phenomena, and to provide mathematical models to simulate them. Finally, implementing of nanofluids to design a freezing-chucker with an insided Uturned two-pass channel is experimentally studied. Typical structure of a freezing-chucker includes a top plate, a body with specially designed rib turbulators inside it, and a bottom plate, respectively, and its physical model can be considered as a three-dimensional domain which composed of the top and bottom Cu plates, and the flowing channel for nanofluids. The inlet and outlet of the flow is located in the same side. An experimental IR thermographic method for the evaluation of surface temperature distribution of the top plate is adopted to show the convective heat transfer effects of nanofluids.
A New Approach of Optimizing the Operation for Atomic Force Microscope in Tapping Mode (II) [ 下載 PDF ]
Ming Yen Lin, Shao Kang Hung, Chi-Yen Juan, Wei Che Liu, Yang Chih Su, Sean Ying
Tapping mode, one of the imaging methods in the atomic force microscope, has been widely used in surface measurement for decades. However, most operators who do not know the nature of the AFM may probably acquire a wrong image by try-and-error or improper setup of the AFM. In this article, according to the tip-sample interaction, a theory and method of optimizing the oscillating amplitude of the probe tip and the set point of the feedback system, is analytically developed from the tip sensitivity and the tip energy dissipation. A new approach of the Tapping mode, including both dynamic factors of the surface topography variation and the system feedback in scanning, is developed for the optimum criterion for AFM operation. Furthermore, the developed theory, method and rule were proved by the images scanned from four different samples. And each sample was scanned by one of four different AFMs with the process of the noise minimization and feedback gain optimization. Therefore, a theory, method and rule of optimizing the operation for AFM in tapping mode are provided and allow users to acquire images in best quality. Finally, an image with fine structures on the surface of amyloid fibrils that cause the Alzheimer’s disease was first observed coincidentally during the experiments. We believe that the discovery will definitely contribute to reveal the forming process of the deposition of protein fibrils.
The Principles and Applications of Proton Transfer Reaction－Mass Spectrometer (PTR-MS) [ 下載 PDF ]
Fu-Der Mai, Ni-Chen Chiang, Hsiao-Hui Yang, Wen-Mei Chung
Proton transfer reaction-mass spectrometer (PTR-MS) is capable of quantitatively on-line monitoring volatile organic compounds (VOCs). The fundamental difference between a conventional MS and PTR-MS is the 'soft ionization' method used by PTR-MS to ionize the organic molecules. The advantage of this method, besides immediately yielding absolute concentration, is that fragmentation of the molecules is very much reduced so the mass spectra produced are much easier to interpret and are more straightforward to quantify. This novel technique enables a variety of organic species in complex matrices to be monitored in real-time (within seconds), with detection limits as low as a few parts per trillion, volume (pptv). PTR-MS extend its applicability to broad fields such as environment analysis, food research, and medical application.
Recently Technologies Development of High-Power White Light Emitting Diodes [ 下載 PDF ]
Shien-Kuei Liaw, Shih-Yi Chang
With the merits of low thermal problem, power reduction, long life time, quick response characteristic, compact size and flat panel package, light emitting diode (LED) plays an important role in modern lighting industry. Nowadays, the 40 lm/W lighting efficiency for white LED lags behind that of a commercial incandescent lamp of 60 lm/W lighting efficiency. Nevertheless, the 100 lm/W lighting efficiency has been demonstrated by some laboratories recently. White LED is believed to dominate the lighting market when it achieves a target value of 100 lm/W lighting efficiency with high reliability in the near future. In this article, we will summary our point-of-views in scientific principle, devices fabrication and market status of high-power, white light LED.
Study of the Measurement Technology of Anesthetic Gas Sevoflurane [ 下載 PDF ]
Ren-Jang Wu, Yu-Ching Huang, Hsiang Ning Liu, Tzu Hsuan Lin, Shih-Lin Hung, Murthy Chavali
The introduction of measurement of anesthetic gas was discussed in this paper, and researched and developed new type sensor. By using the way of photo-polymerization to fabricate the conducting polymer polypyrrole, and the polymer was acted as the sensing material to detect the anesthetic gas sevoflurane. The sensor response (sensitivities) were 4 to 6, in the concentration of sevoflurane were 1200 ppm to 10%. Response time and recovery time were about 60 s and 20 s, respectively, in 1200 ppm. By the theoretical calculation of molecular visual software to simulate the sevoflurane adsorbed on polypyrrole, the bond lengths are about 0.2 to 0.4 nm, and the hydrogen bond N-H---F might be formed between the sevoflurane and polypyrrole.
