• Title/Summary/Keyword: Black Film

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Effect of Silicon on the Corrosion Characteristics of Zirconium (Zr의 부식특성에 미치는 Si의 영향)

  • Jeon, Chi-Jung;Kim, Hee-Suk;Kim, Yong-Deok;Hong, Hyun-Seon;Kim, Seon-Jin;Lee, Kyung-Sub
    • Korean Journal of Materials Research
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    • v.8 no.6
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    • pp.513-519
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    • 1998
  • Zr-Si binary alloys containing 0.01 to O.lwt.%Si were prepared to investigate the effect of Si on the corrosion behavior of Zr. Corrosion test was performed in pure water at 36$0^{\circ}C$ under a pressure of 2660psi for 100days. The alloys containing 0.01 wt. % and 0.05wt. %Si had the black and uniform oxide film and didn't show the transition of corrosion rate. However. the alloys containing O.lwt.%Si had white oxide film and showed the trasition of corrosion rate at 70 days corrosion test. The weight gain increased with the increasing Si content from 0.01 to 0.1 wt.%. The variation of Si contents had no effect on changing the oxide structure but had significant effect on the electrical resistivity of oxide. The electrical resistivity decreased with increasing Si content. The fraction of precipitates in the Zr-Si binary alloys. identified as tetragonal $Zr_{3}$Si increased with increasing Si content. The increase of the volume fraction of precipitates is thought to be responsible for the increase of weight gain due to short circuit effect of precipitate.

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Studies on Factors Affected on Rooting of Aloe vera Cutting (Aloe vera의 삽목 발근에 미치는 제요인에 관한 연구)

  • Jeong, Ho-Seon;Chim, Jae-Seong;Park, Tae-Eun
    • The Journal of Natural Sciences
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    • v.6 no.1
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    • pp.55-64
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    • 1993
  • Experiments were conducted to study the effect of auxins and cultural factors on rooting characteristics in offshoots cutting of Aloe vera. The result obtained were as follows;1. Short offshoots(15-20cm) with rhizome had more roots than that of the removed rhizome, while long offshoots(25-30cm) without rhizome had more roots and heavier root dry weight than short offshoots with rhizome. The highest rooting ability occured when IBA treated 500mg per liter in short offshoots with rhizome, whereas long offshoots without rhizome showed higher rooting ability at the level of 1,000mg/l of IBA and 200mg/I of NAA2. Among three kinds of anxin treated, both IBA and NAA showed better rooting ability than ethychlozate. Root number, root length and root dry weight were higher at 10 min. dipping treatment of IBA 500mg/I for short off-shoots without rhizome and 10 min. dipping treatment of IBA 1,000mg/l for long offshoots with rhizome. Rooting ability of long offshoots was higher than that of short offshoots.3. In addition to IBA 1,000mg/l, 7-day dryness under shading condition increased root number and dry weight of root in offshoots without rhizome. Control treatment lengthened root by increasing drying period under the shading condition.4. The plain soil with mamure had not only higher root dofferentiation but higher root growth of offshoots cutting than the artificial soil.5. Rooting ability in offshoots cutting had a tendency increasing with decrease in shading percentage to natural. Black color poly ethylene film mulching had better rooting ablility than transparency poly ethlene film mulching in offshoots cutting.

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A Study on Materials and Techniques of Lacquer Ware from Hwangnamdaechong in Gyeongju (경주 황남대총 출토 칠제품의 재질 및 기법조사)

  • Humio, Okada;Lee, Eun Seok;Lim, Ji Young
    • Korean Journal of Heritage: History & Science
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    • v.42 no.3
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    • pp.176-191
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    • 2009
  • This report is a result of investigating the materials and techniques of the lacquer ware excavated from Hwangnamdaechong Tomb known as an old tomb in the Gyeongju maximum district. First, the fragment of lacquer ware was classified by the shape of it. Next, the thin section of lacquer film (all sides about 2mm) was made based on the result. Then they were observed under the microscope, and classified the kind of the foundation mixture and the applied structure. It is a result as follows. 1 The bone dust was mixed by the foundation of the made of cloth-body lacquer ware such as eared lacquer cup, lacquer bowl, and the lacquer rectangular containers excavated from the south tomb. 2 Eared lacquer cup and lacquer bowl, and rectangular box excavated from south and north tomb had the possibility they were the set of articles partially of tableware and the cosmetic box. 3 There is a difference in the quality of burial lacquer ware between in south tomb and north tomb. A lot of highlevel lacquer ware such as eared lacquer cup, lacquer bowl and the rectangular lacquer containers were discovered from the south tomb. 4 Many of containers where animal and bird had been drawn on the black lacquered ground excavated from north tomb were wooden bath.

Racism in the movie ≪Green Book≫ and solutions through discussion (영화 ≪그린북≫에 나타난 인종주의와 토의를 통한 해결 방안)

  • Park, Joo Eun
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.3
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    • pp.159-165
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    • 2022
  • The purpose of this study is to examine racism in the movie ≪Green Book≫ and to find solutions to racism through discussion with students. Set in 1962 in the United States, this film depicts the process of forming a good bond with the black pianist Dr. Shirley and the driver Tony in a racist society. This study utilized the subject of race, one of the subjects covered in the humanities class in the global era of S University in the second semester of 2021. This is because, since the outbreak of racism, the problem of racism has continued to arise in the current COVID-19 pandemic situation. Therefore, the researcher looked at racism and intercultural education as a theoretical background, and looked at cases of racism in movies and cases of racism that have occurred today. The history of racism and discrimination dates back to medieval Europe and was caused by religious conflicts and was attributed to white supremacy. As a solution to this racial discrimination, international organizations suggested intercultural education. And the reason why film was used in this study is because it aims to provoke students' interest and motivation for learning by targeting first-year university students called the digital native generation who were born and grew up with the Internet. In this study, students' solutions to racism were presented using discussion, and then the researcher's solutions were presented.

Water Repellency on a Nanostructured Superhydrophobic Carbon Fibers Network

  • Ko, Tae-Jun;Her, Eun-Kyu;Shin, Bong-Su;Kim, Ho-Young;Lee, Kwang-Ryeol;Hong, Bo-Ki;Kim, Sae-Hoon;Oh, Kyu-Hwan;Moon, Myoung-Woon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.224-224
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    • 2012
  • For decades, carbon fiber has expanded their application fields from reinforced composites to energy storage and transfer technologies such as electrodes for super-capacitors and lithium ion batteries and gas diffusion layers for proton exchange membrane fuel cell. Especially in fuel cell, water repellency of gas diffusion layer has become very important property for preventing flooding which is induced by condensed water could damage the fuel cell performance. In this work, we fabricated superhydrophobic network of carbon fiber with high aspect ratio hair-like nanostructure by preferential oxygen plasma etching. Superhydrophobic carbon fiber surfaces were achieved by hydrophobic material coating with a siloxane-based hydrocarbon film, which increased the water contact angle from $147^{\circ}$ to $163^{\circ}$ and decreased the contact angle hysteresis from $71^{\circ}$ to below $5^{\circ}$, sufficient to cause droplet roll-off from the surface in millimeter scale water droplet deposition test. Also, we have explored that the condensation behavior (nucleation and growth) of water droplet on the superhydrophobic carbon fiber were significantly retarded due to the high-aspect-ratio nanostructures under super-saturated vapor conditions. It is implied that superhydrophobic carbon fiber can provide a passage for vapor or gas flow in wet environments such as a gas diffusion layer requiring the effective water removal in the operation of proton exchange membrane fuel cell. Moreover, such nanostructuring of carbon-based materials can be extended to carbon fiber, carbon black or carbon films for applications as a cathode in lithium batteries or carbon fiber composites.

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Observation by the Microscopic Analysis of Lacquer Layer for Identification of Lacquer-ware Function (칠 기법 규명을 위한 칠도막의 현미경 관찰)

  • Kim, Soo-Chul;Lee, Kwang-Hee
    • Journal of the Korean Wood Science and Technology
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    • v.36 no.6
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    • pp.96-104
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    • 2008
  • In this study, the observation of test pieces with an optical microscope was carried out after fabricating 4 groups of standard lacquer, in order to inquire into the ancient lacquering techniques. Group I had transparent reddish brown color, and the part of layer was indefinite, and the layer polished was easily distinguished. Group II had mostly transparent yellowish brown color, and it was possibility distinguished the layers when they were varnished with mixed lacquer after prime coating, and when they were varnished with lacquer as the prime coating. Group III set up membrane in the hardening process of the lacquer, and the lacquer and the unsaturated fatty acid of internal part was dried, so the top layer and the lacquer layer were separated and observed. Group IV: When the lacquer coat film of Group IV test pieces were observed in polarized light, the ferrous components were seen as the black and red color were mixed, and the silica crystals of silty soil were distinguished by reflection of lights. And the colors were distinguished as the lacquer layer of ruddle had red color, and the mixed lacquer of reddish lacquer and ruddle had the deep red color at the top and the bottom, but the middle part had the bright red color.

Review on the Use of Solar Energy for Grain Drying (태양열을 이용한 곡물건조에 관한 연구)

  • 금동혁;고학균;최재갑
    • Journal of Biosystems Engineering
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    • v.3 no.1
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    • pp.64-76
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    • 1978
  • A dimensional supply of petroleum fuels and increased competition for petroleum products has made the conservation of energy in grain drying an important cost and management factor. Research on solar grain drying is directed toward utilization of a renewable energy source as an alternative to petroleum fuels for drying. There are many technical and economic problems in accepting and adopting solor energy as a new energy source for grain drying. The purpose of this study are to assess the state of the art of solar grain drying and to find out the problems by reviewing literatures available. The results obtained may be summarized as follows; 1.It may be considered that the weather conditions in October of Korea was satisfactory for the forced natural air and solar heated air drying. 2. Solar energy is considered more applicable to low-temperature, In-storage drying systems than to high-temperature, high-speed drying systems. In-storage drying systems require low levels of heat input. The costs of collector systems to provide low temperature are considerably cheaper than for high-temperature systems. 3. Tubular type collector made of polyvinyle film seems to be the most practical at this stage of development and black-painted bare-plate collectors mounted on the outside of a typical, round, low-temperature drying bin can supply an appreciable amount of the energy efficiently needed for low-temperature grain drying at a lower cost. 4. All of the grains in solar drying tests was successfully dried up to safe storaged moisture levels without significant spoilage. Drying rates with solar system were faster than natural air drying systems, and usually a little slower than similar low-temperature electric drying systems. 5. Final grain moisture levels were lower in solar tests than in natural air tests, and generally higher than in tests with continuous heated air. 6. Savings of energy by use of solar collectors ranged from 23% to 55%, compared to the natural and electric ileated air drying systems. However, total drying cost effectiteness tvas not significant. Therefore, it is desirable that solar grain dry-ing sIFstems tvhich could be suitable for multiple heating purposes on farms shouldbe developed. 7. Supplemental heat with solar radiation did little to reduce air flow requirementsbut refuced drying time and increased the p\ulcornerobability of successful drying duringdrying poriod.

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Summer Softening Cultured Yield and Its Income of Aralia continentalis Kita. (땅두릅의 여름철 연화재배 수량과 경제성)

  • 김시동
    • Korean Journal of Plant Resources
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    • v.8 no.2
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    • pp.183-188
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    • 1995
  • This experiment was carried out to clarity the effect of summer softening cultivation on bud yield of Aralia continentalis Kita. Bulbous plant harvested on March 25 and stored in low temperature storage room($0-2^{\circ}C$) were transplanted in May, June, July and August. The bulbous plants were grown under black PE film and 50%(T-2250) silver shading nets. The results obtained are summerized as fallows. Harvesting time in Jul. and Aug. transplanting was 15days and was speeling 5days in May transplanting. The accumulative temperature of whole growth period was about $400^{\circ}C$. But yield of soft stems in June transplanting was 6.64(ton/ha), which was more than others. High temperature induced low-quality of soft stem in transplanting in July. Net income was 18000(1000won/ha) in transplanting in May or June.

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Effect of Delayed Sowing on Growth, Flowering Date, and Yield in Sesame

  • Lee, Sung-Woo;Kang, Churl-Whan;Kim, Dong-Hwi;Shim, Kang-Bo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.46 no.2
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    • pp.130-133
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    • 2001
  • The purpose of this study was to investigate the decreased ratio of growth and yield by delayed seeding and flowering because drought of spring season often cause to delay seeding and sprout emergence. Equation of linear regression, y=-11.914x+818.61 ($R^2$=0.916) and y=-16.96lx+913.98 ($R^2$=-0.885) were derived from relationship between sowing date and yield of leading variety, Yangbaeckkae in 1999 and 2000, respectively. Yield was decreased by 7, 24, 40, 57, 74%, respectively, according as sowing date was delayed more 5, 15, 26, 36, 46 days than May 15, standard sowing date under the culture mulched with black P.E. film. Number of capsules per plant and length of stem bearing capsule were greatly decreased, while plant height, stem diameter, and day to flowering were affected little by delayed seeding date. Equation of linear regression, y=-0.7081x+41.04 ($R^2$=0.861) was derived from relationship between flowering date and yield of 33 accessions. Yield was decreased by 7.7, 8.3, 9.2, 10.1, 11.2%, respectively, according as flowering date was delayed more 1, 2, 3, 4, 5 days than July 3, normal flowering date of Yangbaeckkae when it was sown on May 15, and the more flowering date was delayed, the more yield was decreased. Number of capsules per plant and length of stem bearing capsules were greatly decreased, but plant height and harvest index were decreased little by delay of flowering date

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Dielectric Passivation Effects for the Prevention of the Failures and for the Improvement of the Reliability in Microelectronic Thin Film Interconnections (극미세 전자소자 박막배선의 결함방지 및 신뢰도 향상을 위한 절연보호막 효과)

  • 양인철;김진영
    • Journal of the Korean Vacuum Society
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    • v.4 no.2
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    • pp.217-223
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    • 1995
  • 절연보호막에 따른 AI-1%Si 박막배선의 평균수명(MTF, Mean-Time-to-Failure) 및 electromigration에 대한 저항성, 즉 활성화에너지(Q)변화 등을 측정 비교하였다. 박막배선은 $5000\AA$두께로 열산화막 처리된 p-Si(100)기판위에 $7000\AA$의 AI-1%Si을 증착한 후 photolithography 공정으로 형성시켰다. Electromigration test를 위한 박막배선은 $3\mu$m의 폭과 $400\mu$m, $1600\mu$m의 두 가지 길이를 가지며 절연보호막 효과를 알아보기 위해 그 위에 $3000\AA$의 두께로 SiO2, PSG, Si3N4등 절연보호막을 APCVD 및 PECVD를 이용하여 각각 증착시켰다. 가속화 실험을 위해 인가된 전류밀도는 4.5X106A/cm2이었고 180, 210, $240^{\circ}C$온도에서 d.c. 인가 후의 저항변화를 측정하여 평균수명을 구한 후 Black 방정식을 이용하여 활성화에너지를 측정하였다. AI-1%Si 박막배선에서 electromigration에 대한 활성화에너지값은 $400\mu$m길이의 경우 0.44eV(nonpassivated), 0.45eV(Si3N4 passivated), 0.50 eV(PSG passivated), 그리고 0.66 eV(SiO2 passivated)로 각각 측정되었다. $1600\mu$m 길이의 AI-1%Si 박막배선 실험에서도 같은 절연보호막 효과가 관찰되었다. 따라서 SiO2, PSG, Si3N4등 절연보호막은 AI-1%Si 박막배선에서의 electromigration에 대한 저항력을 높여 결함방지효과를 보이며 수명을 향상시킨다. SiO2의 절연보호막의 경우가 AI-1%Si 박막배선의 electromigration에 대한 가장 강한 저항력을 보이며 평균수명도 높게 나타났다.

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