• Title/Summary/Keyword: GaAs(100) Surface

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Growth of HgCdTe thin film by the hot-wall epitaxy method (Hot-wall epitaxy 방법에 의한 HgCdTe 박막 성장)

  • 최규상;정태수
    • Journal of the Korean Vacuum Society
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    • v.9 no.4
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    • pp.406-410
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    • 2000
  • Using the hot-wall epitaxy method, we grew a $Hg_{1-x}Cd_xTe$ (MCT) thin film in-situ after growing (111) CdTe of 9 $mu \textrm{m}$ as a buffer layer. The value of FWHM of double crystal x-ray diffraction rocking curve was 125 arcsec and the surface morphology was clean with a small roughness of 10 nm. From measuring the photocurrent of the grown MCT thin film, the maximum peak wavelength and the cut-off wavelength were 1.1050 $\mu\textrm{m}$ (1.1220 eV) and 1.2632 $\mu\textrm{m}$ (0.9815 eV), respectively. This peak wavelength corresponds to the peak of the band gap due to the intrinsic transition of the photoconductor. Therefore, the MCT thin film could be used as the photoconducting detector sensing a near-IR wavelength band from 1.0 to 1.6 $\mu\textrm{m}$.

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Assessment of Daily Steps, Activity Coefficient and Daily Energy Expenditures of Dieticians in Youngdong-area (영동지역 영양사의 1일 보행수, 활동계수 및 에너지 소비량 평가)

  • Lee, Jeong-Suk;Lee, Ga-Hui;Kim, Eun-Gyeong
    • Journal of the Korean Dietetic Association
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    • v.12 no.3
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    • pp.277-288
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    • 2006
  • The purpose of this study was to assess the energy expenditure and investigate the relationship between related variables of 57 dieticians in Youngdong-area. The average daily number of steps was found to be 9358.0$\pm$2714.3 steps/day on weekdays and 7862.9$\pm$2504.9 steps/day during weekends. Hourly step rates on weekdays and weekends came to 570.6$\pm$249.8 steps/hr and 564.0$\pm$224.8 steps/hr, respectively. Activity coefficient of subjects was higher on weekdays (1.56) than weekends (1.51, p<0.05). Resting energy expenditure estimated by the Harris-Benedict formula, WHO/NAO/FAO formula as well as formulas based on body surface area and DRIs (Dietary Reference Intake for Koreans) were calculated to be 1333.7$\pm$89.5kcal/day, 1351.0$\pm$123.3kcal/day, 1388.5$\pm$100.3kcal/day and 1295.9$\pm$90.8kcal/day, respectively. Using these resting energy expenditures and the activity coefficients, daily energy expenditures were calculated to be from 2039.7kcal/day to 2183.5kcal/day on weekdays and from 2016.1kcal/day to 2159.2kcal/day on weekends. Meanwhile energy intakes of subjects on weekdays and weekends were 1594.7$\pm$698.3kcal and 2152.9$\pm$768.0kcal, respectively. The activity coefficient (1.49) of dieticians who managed less than 500 meals per day was significantly lower than that of dieticians who served more than 500 meals per day. Dieticians of schools located in rural areas had higher activity coefficient (1.59) than those of schools located in urban or island settings. These results suggest that work analysis and development of management strategies are necessary to improve dieticians' productivity.

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Flexibility Improvement of InGaZnO Thin Film Transistors Using Organic/inorganic Hybrid Gate Dielectrics

  • Hwang, B.U.;Kim, D.I.;Jeon, H.S.;Lee, H.J.;Lee, N.E.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.341-341
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    • 2012
  • Recently, oxide semi-conductor materials have been investigated as promising candidates replacing a-Si:H and poly-Si semiconductor because they have some advantages of a room-temperature process, low-cost, high performance and various applications in flexible and transparent electronics. Particularly, amorphous indium-gallium-zinc-oxide (a-IGZO) is an interesting semiconductor material for use in flexible thin film transistor (TFT) fabrication due to the high carrier mobility and low deposition temperatures. In this work, we demonstrated improvement of flexibility in IGZO TFTs, which were fabricated on polyimide (PI) substrate. At first, a thin poly-4vinyl phenol (PVP) layer was spin coated on PI substrate for making a smooth surface up to 0.3 nm, which was required to form high quality active layer. Then, Ni gate electrode of 100 nm was deposited on the bare PVP layer by e-beam evaporator using a shadow mask. The PVP and $Al_2O_3$ layers with different thicknesses were used for organic/inorganic multi gate dielectric, which were formed by spin coater and atomic layer deposition (ALD), respectively, at $200^{\circ}C$. 70 nm IGZO semiconductor layer and 70 nm Al source/drain electrodes were respectively deposited by RF magnetron sputter and thermal evaporator using shadow masks. Then, IGZO layer was annealed on a hotplate at $200^{\circ}C$ for 1 hour. Standard electrical characteristics of transistors were measured by a semiconductor parameter analyzer at room temperature in the dark and performance of devices then was also evaluated under static and dynamic mechanical deformation. The IGZO TFTs incorporating hybrid gate dielectrics showed a high flexibility compared to the device with single structural gate dielectrics. The effects of mechanical deformation on the TFT characteristics will be discussed in detail.

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Alteration of the Stability in Training Ship Pusan 403 (실습선 부산403호의 복원성 변화)

  • KIM Sam-Kon;KIM Jong-Hwa;CHOE Jong-Hwa;KIM Yeong-Sik
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.18 no.2
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    • pp.94-100
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    • 1985
  • M/S Pusan 403(GT 243, 1000ps) was originally built as a research vessel on skipjack pole and line fishing in 1972. She had begun to serve as a fishing training ship of National Fisheries University of Pusan from 1974, since the interior structure has been remodelled and some weight articles have been removed, her stability is in doubt. The authors carried out an inclining experiment by using two pendulums at fore and aft with two weights on both sides. Each value obtained was compared with the IMO safety code for fishing vessels and safety regulation for fishing vessels of Korea. 1. The GZ value, being 0.207 m under light ship condition and 0.325 m under departure condition with full load, can be assumed as no impediment on her stability, 2. Under the light ship condition, GM decreased by 0.046 m and KG increased by 0.141 m, compared with the values determined at the time of official sea trial. Therefore, no impediment on the stability exists. 3. The GM decreased by 0.163 m and the KG increased by 0.173 m, compared with the values determined at the time of official sea trial. In no consideration of the free surface effects of liquid in the oil and fresh water tanks, no impediment on the stability exists. But, in consideration of the free surface effect, it may be regarded that some impediment exists.

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Effects of Cutting Management during Summer Season on Growth and Reserve Carbohydrates of Orchardgrass (고온기 예취방법이 Orchardgrass의 생장 및 탄수화물 축적에 미치는 영향)

  • 김정철;최기춘;김광현;김우복
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.13 no.4
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    • pp.257-267
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    • 1993
  • Optimum pasture management during the summer season is an important factor to maintain good regrowth and persistence of pasture. The field experiment was carried out to investigate the effects of cutting management on growth and reserve carbohydrates in stubble. and on dry matter yield of orchardgrass dominated pasture during the mid-summer season. Three different cutting times(July 15, 25 and August 5) as a main plot and three cutting heights(3, 6 and 10cm) as a sub plot were disigned with three replications. The experiment was done at pasture of Changsung Agricultural High School in 1988. The results obtained were summarized as follows: 1. Temperature of soil surface and underground in the cutting of July 15 and July 25 was not showed significantly different, because of low intensity of radiation with a run of wet weather, and that of August 5 cutting tends to be lowed in high cutting height during the mid-summer season. 2. Amount of soil moisture against cutting height showed that high cutting had a low content. 3. Growth rate against regrowth of plant height, lear length and leaf area showed to be fast in high cutting. 4. Rapid recovery period of carbohydrate content after cutting and large amount of carbohydrate accumulation were showed in the cutting of July 15 and 25 compared with August 5 cutting in the reserve carbohydrate content against cutting of time and height during the mid-summer season. 5. Dry matter yield of the 4th and 5th cutting showed to be remarkable in July 15 cutting compared to those of July 25 and August 5. From the above results, it is suggested that the 10cm cutting height during the mid-summer season is the most effective for good regrowth, reserve carbohydrates and dry matter yield of orchardgrass.

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Do Paneth Cells Regulate the Zinc Body Burden? (Zinc 대사와 관련된 Paneth 세포활성의 변화에 관한 조직화학적 연구)

  • Jo, Seung-Mook;Kim, Sung-Jun;Park, Seung-Kook;Kang, Tae-Cheon;Won, Moo-Ho
    • Applied Microscopy
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    • v.30 no.4
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    • pp.357-365
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    • 2000
  • Paneth cells have been suggested to contribute to the elimination of excess metals into the intestinal lumen. The purpose of this study wat to investigate the changes of the zinc pools in rats subjected to functional loading with zinc salt by mean of both light and electron microscopical autometallography (AMG). Wistar rats 4 were administrated with zinc chloride (20 mg/kg body weight) intraperitoneally dissolved in 1 ml distilled water. The control group received 1 ml saline IP. After further one hour the animals were transcardially perfused with 0.4% sodium sulphide dissolved in 0.1 M PB fellowed by 3% glutaraldehyde solution for 10 minutes. Pieces of ileum were frozen with solid $CO_2$ and sectioned on a cryostat. The sections $(20{\mu}m)$ were autometallographically developed. Sections selected for EM were reembedded on top of a blank Epon block, from which ultrathin sections (100 nm) were cut. The ultrathin sections were double stained with uranyl acetate (30 min) and lead citrate (5 min), then examined under electron microscope. Studies of comparable sections from control and zinc loaded animals with the AMG selenium method gave quite different results. The control animals demonstrated a weakly positive staining in the cytoplasm of the Paneth cells. In the electron microscope the AMG silver grains were found to be located in the cytoplasm, while the electron dense secretary granules and other cell organelles were void of staining. Few AMG grains were located at the apical surface of the Paneth cells. In sections from zinc loaded rats, the AMG grains were seen in abundance in the lumen of the Lieberkuhn crypts at light microscopic levels. At EM levels the zinc revealing silver grains were located in the cytoplasm as in the controls, but much more AMG grains were shifted into the secretary granules. Furthermore, profound AMG grains were found in the lumen of the crypts and surrounding vessels. And a few grains were seen in the endothelium. The AMG technique demonstrated a pattern of AMG grains in the Paneth cells that strongly suggests a transport of zinc ions through these cells.

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