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[en] This textbook introduces the instrumental analysis. The contents of this first part are DR-OES, XRF, XRD, EIA, AAS, GC, HPLC, MS, TGA, EOA, NMR, SEM, EPMA, Rheometric Dynamic Spectrometry, Particle Size Analysis, PICTS and Photoconductivity, Photoluminescence Spectroscopy, Supercritical Fluid Chromatography, Capillary Electrophoresis, and Capillary Electrophoresis. The second part lists the research unit such as applied science, metal, ceramics and information and electronics.
[en] This book describes how to use the internet with world wide web. It is divided into six chapters, which are Let's go to the internet ocean, the internet in information superhighway are, connecting the world with a telephone wire such as link with the internet cable and telephone modem, internet service providers, text mode connection, Domain and IP address, the principle and use of world wide web ; business, music, fashion, movie and photo, internet news and e-mail, making internet map with web language, and from installation to application of base program such as TCP/IP, SLIP/PPP 3270 Emulator, Finger and NCSA Mosaic.
[en] You showed that nanofluids, containing only 0.005 g/l of alumina nanoparticle, make the dramatic increase (∼ 200%) in CHF in pool boiling at the pressure of 2.89 psia (Tsat=60 .deg. C). They concluded that the abnormal CHF enhancement of nanofluids cannot be explained with any existing models of CHF. Vassallo performed the experimental studies on pool boiling heat transfer in water-SiO2 nanofluid under atmospheric pressure. They showed a remarkable increase in CHF for nanofluid and also found that the stable film boiling at temperatures close to the melting point of the boiling surface are achievable with the nanofluid. H.D. Kim said a CHF enhancement mechanism in the nanofluids that is based to surface effect using a wire heater supplying a power as electric DC power. But nanoparticle deposited phenomena may be asked whether by boiling procedure, or by electric filed effect on the surface. So the flat plate experimental apparatus supporting only thermal heating is developed to perform the CHF enhancement experiment with nanofluid in pool boiling. The copper surface was used as heater surfaces and nanofluid was created with Al2O3, TiO2 nanoparticles and deionized water by 2-step methods. And CHF in deionized water enhances on nanoparticles deposited surface. So, CHF enhancement in nanofluid is also achieved by the surface effect. For this result, surface investigation (SEM, contact angle and roughness) about the nanoparticle coated surface was performed
[en] It has been well known that pool boiling CHF in nanofluids compared to pure water significantly increase due to the deposition of nanoparticles on heater surface. This study concerns the characteristics of the nanoparticle deposition layer and its influence on CHF. Pool boiling experiments were carried out with 0.01vol.% water-TiO2 nanofluids to obtain various nanoparticle-deposited heaters. CHF on the prepared heaters was measured during pool boiling in pure water. The heater surfaces were visualized using Scanning Electron Microscope (SEM) and also characterized using contact angle and capillarity. The results showed that the CHF enhancement in nanofluids was completely dependent upon the structural and physicochemical characteristics of the nanoparticle deposition layer
[en] The flat plate experimental apparatus supporting only thermal heating was developed to perform the CHF enhancement experiment with nanofluids in pool boiling. Nickel and copper surface was used as heater surfaces and nanofluids was created with Al2O3, TiO2 nanoparticles and deionized water by 2-step methods. And CHF in deionized water enhance on nanoparticles deposited surface. So, CHF enhancement in nanofluids is also achieved by the surface effect. CHF enhancement quantities are different as a kind of surface. Copper surface have more CHF enhancement than nickel in same nanofluids. And boiling in Al2O3, TiO2 nanofluids made different surface shape. Surface investigation (SEM) about the nanoparticles coated surface was performed. And these different surfaces induced a different CHF enhancement ratio
[en] Over the past years, the enhancement of nucleate boiling heat transfer is an interesting topic in two-phase area. Because of this point, many researchers attempt to derive a better nucleate boiling heat transfer condition. Among those many tries, the change of wettability is regarded as a powerful method. Recent studies have shown that the nucleation site density, which is a dominant factor on nucleate heat transfer, is related with the surface wettability. In this respect, the pool boiling experiment result on interesting surface, which has the hydrophobic milli-dots on the silicon surface, is introduced in this paper
[en] It is well known that modifying the geometry or characteristics of heater surface is one of the effective ways in enhancing CHF. Also many researchers have been struggling to develop fine and fancy heater surface by various methods so far. Lately, there were lots of research about enormous CHF enhancement with nanofluids, which is well dispersed fluid with nano-sized particles, and it was proved that this phenomenon definitely depends on deposition of nanoparticle over heater surface. We have observed micro/nano multi-scale geometry and high wettability characteristic on naturally developed nanoparticle deposited heater surface from boiling experiment with nanofluid. On the base of this observation, we made micro/nano multi-scale surface with good wettability by MEMs technique, and conducted CHF experiments with them
[en] Many pool boiling experiments to increase the nucleate boiling condition have been conducted and could get brilliant and challengeable results. The fact that the enhancement of CHF in pool boiling is strongly dependent on the surface wettability effect is also supported by other kinds of boiling experiments. In this regard, the excellent CHF condition in pool boiling could be achieved through some favorable surface modification which satisfies the optimized wettability condition. For finding the optimized condition, we design the special heaters to visualize how two materials, which have different wettability, affect the boiling phenomena. The special heaters have hydrophobic dots on the silicon surface. The peculiar teflon(AF1600) is used as the hydrophobic material. The contact angle of the heating surface which is made by teflon is 120 .deg. to water at the room temperature. The contact angle of the silicon surface is 60 .deg. at the room temperature. The experiment using the milli-sized hydrophobic dot is performed on the flat silicon surface
[en] A newly released reanalysis dataset covering the period 1979–2009 is analyzed to show that the sea surface temperature (SST) variability in the tropical central Pacific is more closely related to the SST variability in the tropical eastern Pacific before 1990 but more closely related to sea level pressure (SLP) variations associated with the North Pacific Oscillation (NPO) after 1990. Only during the period after 1990 can the NPO excite large SST variability in the tropical central Pacific. Related to this change, El Niño Southern Oscillation (ENSO) SST anomalies tend to spread from the eastern to central tropical Pacific before 1990 in a pattern resembling that associated with the Eastern Pacific (EP) type of ENSO, but are more closely connected to SST variability in the subtropical north Pacific after 1990 with a pattern resembling that of the Central Pacific (CP) type of ENSO. This study concludes that the increased influence of the NPO on the tropical Pacific is a likely reason for the increasing occurrence of the CP type of ENSO since 1990. An analysis of the mean atmospheric circulation during these two periods suggests that the increased NPO influence is associated with a strengthening Hadley circulation after 1990. (letter)