• Title/Summary/Keyword: Surface Temperatures

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Deformation of Amorphous GeSe2 Film under Uniaxial Pressure Applied at Elevated Temperatures

  • Jin, Byeong Kyou;Lee, Jun Ho;Yi, Jeong Han;Lee, Woo Hyung;Shin, Sang Yeol;Choi, Yong Gyu
    • Journal of the Korean Ceramic Society
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    • v.52 no.2
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    • pp.108-113
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    • 2015
  • In an effort to evaluate the practicability of an imprinting technique for amorphous chalcogenide film in Ge-based compositions, we investigate the deformation behavior of the surface of amorphous $GeSe_2$ film deposited via a thermal evaporation route according to varying static loads applied at elevated temperatures. We observe that, under these static loading conditions, crystallization tends to occur on its surface relatively more easily than in As-based $As_2Se_3$ films. As for the present $GeSe_2$ film, higher processing temperatures are required in order to make its surface reflect the given stamp patterns well; however, in this case, its surface becomes partially crystallized in the monoclinic $GeSe_2$ phase. The increased vulnerability of this amorphous $GeSe_2$ film toward surface crystallization under static loading, when compared with the $As_2Se_3$ counterpart, is explained in terms of the topological aspects of its amorphous structure.

The Response of the Subtropical High to the Variation of the Earth Surface Temperature (지구표면 온도의 변화에 대한 아열대 고기압의 반응)

  • 이재규
    • Journal of Environmental Science International
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    • v.7 no.5
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    • pp.725-733
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    • 1998
  • Three numerical experiments are done using IAP(Institute of Atmospheric Physics) global spectral model(T42L9) to investigate the influence of the surface temperatures on the 7-day simulation. Particularly, the response of the subtropical High in summer to the variation of soil temperature and sea surface temperature(SST) was emphasized through a series of experiments. Experiment 1 uses the June climate data as the earth surface conditions. Experiment 2 is similar to Experiment 1 except for the soil surface temperature. Experiment 3 is the same as Experiment 1 except for the modified SST, which is much warmer than the June climate SST on the sea around the Korean peninsula. The main finding in 7-day simulation is that the response of the subtropical high in summer to the variation of the sell surface temperature was much more than that to the variation of the SST. It is implied that the proper treatment of sell surface temperature is more important than that of the SST for the better 7-day simulation of the subtropical high in summer.

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Measuring Temperature on Wood Surface at the Beginning of Drying Using IR Image Measuring System (적외선 화상처리 장치를 이용한 건조초기 목재 표면 온도 측정)

  • Lee, Kwan-Young;Kang, Ho-Yang;Lee, Min-Kyung
    • Journal of the Korea Furniture Society
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    • v.17 no.3
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    • pp.79-85
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    • 2006
  • Temperature of board surface was monitored during drying using an IR image measurement system. Boards were water-saturated and dried at the levels of four temperatures and three air velocities. At higher DB the surface temperature increased more steeply and level off period was significantly short. At the DB temperatures of 70, 80, $90^{\circ}C$ the period where the surface temperature was equivalent to WB temperature was constant regardless of air velocity while at $60^{\circ}C$ it decreased as air velocity increased. It was confirmed that a surface transfer coefficient increased with DB temperature. Variation of temperature profile on a wood surface increased with DB temperature and air velocity.

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Si(100) ETCHING BY THERMAL-ENERGY HYDROGEN ATOMS

  • Kang, Joo-Hyun;Jo, Sam-Keun;John G. Ekerdt
    • Journal of the Korean Vacuum Society
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    • v.6 no.S1
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    • pp.59-65
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    • 1997
  • Efficient Si(100) etching by thermal H atoms at low substrate temperatures has been achieved. Gas-phase etching product $SiH_4$(g) upon H atom bombardment resulting from direct abstraction of $SiH_3$(a) by impinging H atoms was detected with a quadrupole mass spectrometer over the substrate temperature range of 105-408 K Facile depletion of all surface silyl ($SiH_3$) groups the dissociative adsorption product of disilane ($Si_2H_6$) at 105K from Si(100)2$\times$1 by D atoms and continuous regeneration and removal of $SiD_3$(a) were all consumed. These results provide direct evidence for efficient silicon surface etching by thermal hydrogen bombardment at cryogenic temperatures as low as 105K We attribute the high etching efficiency to the formation and stability of $SiH_3$(a) on Si(100) at lowered surface temperatures allowing the $SiH_3$(a) abstraction reaction by additional H atom to produce $SiH_4$((g).

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Solution-Derived Amorphous Yttrium Gallium Oxide Thin Films for Liquid Crystal Alignment Layers

  • Oh, Byeong-Yun
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.2
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    • pp.109-112
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    • 2016
  • We demonstrated an alternative electrically controlled birefringence liquid crystal (ECB-LC) system with ion beam (IB)-irradiated yttrium gallium oxide (YGaO) alignment films using a sol-gel process. The surface roughness of the films was dependent on the annealing temperature; aggregated particles on surface were observed at lower annealing temperatures, whereas a smooth surface could be obtained with higher annealing temperatures. Higher transmittance in the visible region was observed at higher annealing temperatures. The film had an amorphous crystallographic state irrespective of the annealing temperature. Furthermore, ECB-LC cell with our IB-irradiated YGaO film yielded faster response time when compared to ECB-LC cell with rubbed polyimide. Considering the fast response time and high transmittance, the IB-irradiated YGaO-base LC system is a powerful alternative application for the liquid crystal display industry.

Effects of Packing Pressure and Time on Injection Molding of Plastic Micro-channel Plates (플라스틱 마이크로 채널 기판 사출성형 시 보압의 영향)

  • Woo, Sang-Won;Park, Si-Hwan
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.25 no.3
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    • pp.224-229
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    • 2016
  • Recently, polymeric micro-fluidic biochips with numerous micro patterns on the surface were fabricated by injection molding for realizing low-cost mass production of devices. To evaluate the effects of process parameters on large-scale micro-structure replication, a $50{\times}50mm^2$ tool insert with surface structures having a patterns of trapezoidal shapes (height: $30{\mu}m$) was employed. During injection molding, PMMA was used; packing phase parameters and mold temperature were investigated. The replicated surface textures were quantitatively characterized by confocal laser microscopy with 10-nm resolution. The degree of replication at low mold temperatures was found to be higher than that at high mold temperature at the beginning of the packing stage. Thereafter, the degree of replication increased to a greater extent at higher mold temperatures; application of higher mold temperatures improved the degree of replication.

White Dwarfs in Cataclysmic Variable Stars: Surface Temperatures and Evolution

  • Sion, Edward M.
    • Journal of Astronomy and Space Sciences
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    • v.29 no.2
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    • pp.169-173
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    • 2012
  • A summary is presented of what is currently known about the surface temperatures of accreting white dwarfs (WDs) detected in non-magnetic and magnetic cataclysmic variables (CVs) based upon synthetic spectral analyses of far ultraviolet data. A special focus is placed on WD temperatures above and below the CV period gap as a function of the orbital period, $P_{orb}$. The principal uncertainty of the temperatures for the CV WDs in the $T_{eff}-P_{orb}$ distribution, besides the distance to the CV, is the mass of the WD. Only in eclipsing CV systems, an area of eclipsing binary studies, which was so central to Robert H. Koch's career, is it possible to know CV WD masses with high precision.

Surface temperatures of public buildings, built in 1880, 1970 and 2002, in Northern Greece

  • Kosmopoulos, P.;Kantzioura, A.
    • Advances in Energy Research
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    • v.1 no.1
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    • pp.79-95
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    • 2013
  • The purpose of this paper is to investigate the surface temperatures of the shelter of three public buildings in the city of Xanthi, in northern Greece. The buildings were built in different time periods and consequently they have different technical characteristics. Respectively, we survey the three following buildings that have been built in 1880 (Municipality Hall of Xanthi), in 1970 (Municipality Amphitheatre) and in 2002 (Bank offices building). Data have been gathered by the use of thermal camera and the survey has been conducted from January up to July. The data gathered regard measurements of the surface temperature of the exterior walls of the shelters, both inside and outside. The study aims at the evaluation of the thermal behavior of the shelter of buildings, which built in different time and under different regulations. The gathered data of the surface temperatures compare the different thermal behavior of the shelter. The analysis of the results and diagrams show that the thick masonry of the traditional Municipality Hall offers an insulation that is adequate. The building of 1970, which was constructed with the previous buildings regulation, has thermal losses due to inadequate insulation. The new building of 2002 has low thermal losses.

A Surface Etching for Synthetic Diamonds with Nano-Thick Ni Films and Low Temperature Annealing

  • Song, Jeongho;Noh, Yunyoung;Song, Ohsung
    • Journal of the Korean Ceramic Society
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    • v.52 no.4
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    • pp.279-283
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    • 2015
  • Ni (100 nm thick) was deposited onto synthesized diamonds to fabricate etched diamonds. Next, those diamonds were annealed at varying temperatures ($400{\sim}1200^{\circ}C$) for 30 minutes and then immersed in 30 wt% $HNO_3$ to remove the Ni layers. The etched properties of the diamonds were examined with FE-SEM, micro-Raman, and VSM. The FE-SEM results showed that the Ni agglomerated at a low annealing temperature (${\sim}400^{\circ}C$), and self-aligned hemisphere dots formed at an annealing temperature of $800^{\circ}C$. Those dots became smaller with a bimodal distribution as the annealing temperature increased. After stripping the Ni layers, etch pits and trigons formed with annealing temperatures above $400^{\circ}C$ on the surface of the diamonds. However, surface graphite layers existed above $1000^{\circ}C$. The B-H loop results showed that the coercivity of the samples increased to 320 Oe (from 37 Oe) when the annealing temperature increased to $600^{\circ}C$ and then, decreased to 150 Oe with elevated annealing temperatures. This result indicates that the coercivity was affected by magnetic domain pinning at temperatures below $600^{\circ}C$ and single domain behavior at elevated temperatures above $800^{\circ}C$ consistent with the microstructure results. Thus, the results of this study show that the surface of diamonds can be etched.

A Review on the Paleoclimate Change Inferred from Borehole Temperatures (시추공 온도자료를 이용한 고기후 연구에 대한 개관)

  • Lee, Youngmin;Kim, Hyoung-Chan;Song, Yoonho
    • Economic and Environmental Geology
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    • v.39 no.1 s.176
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    • pp.95-102
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    • 2006
  • To properly interpret and define climatic warming trends of the last $100\~150$ years.; climatic changes over the past several centuries must be constrained. High resolution surface air temperatures (SATs) to reconstruct global temperature trends extend back only to the late of 19th century. Fortunately, on long time scale and over large areas, ground surface temperatures (GSTs) track SATs. GST changes penetrate into the subsurface and are recorded as transient temperature perturbation. Therefore, borehole temperatures can be used to recover climate change over the last millennium in an area; paleoclimate change inferred from borehole temperatures can be used to interpret global warming over the last century, little ice age, and medieval warm period.