• The Korean Journal of Ceramics
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• v.2 no.4
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• pp.221-225
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• 1996

In diamond synthesis by metal film growth method under high pressure and high temperature, the nucleation and growth of diamond was observed dependent on the carbon source variation from graphite powder to the heat treated powders of lamp black carbon. At the low driving force condition near equilibrium pressure and temperature line, nucleation of diamond did not occur but growth of seed diamond appeared in the synthesis from lamp black carbon while both nucleation and growth of diamond took place in the synthesis from graphite. Growth morphology change of diamond occurred from cubo-octahedron to octahedron in the synthesis from graphite but very irregular growth of seed diamond occurred in the synthesis from lamp block carbon. Lamp black carbon transformed to recrystallized graphite first and very nucleation of diamond was observed on the recrystallized graphite surface. Growth morphology of diamond on the recrystallized graphite was clear cubo-octahedron even at higher pressure departure condition from equilibrium pressure and temperature line.

• Proceedings of the Korean Vacuum Society Conference
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• 2006.02a
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• pp.87-87
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• 2006

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.40-50
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• 2022

The Périgord black truffle (Tuber melanosporum) is an edible fungus and among the most expensive foods worldwide. It is the basis of a multimillion-dollar bio-business. Truffle farming does not exist in Mexico, and no formal studies have been conducted on its culture. This report describes the mycorrhizal synthesis (i.e., artificial union of fungus with host) of T. melanosporum with oak species native to Mexico (Quercus polymorpha, Q. fusiformis, and Q. canbyi). The mycorrhizal association was successful in Q. polymorpha and Q. fusiformis, as confirmed morphologically and using T. melanosporum molecular primers (ITSML/ITS4LNG). The effect of the ectomycorrhizal fungus on host growth (stem diameter) was statistically significant. Illustrations of the study are presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3054-3059
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• 2009

Natural black diamonds of single crystal, polycrystalline, and agglomerated roughs become important for their industrial and gem stone application. We performed the conventional gemological tests of thermal diffusion, apparent density, scratch test, and magnification test as well as the advanced tests of Raman spectroscopy, X-ray diffraction test and Lang topography. We conclude that scratch test with SiC paper was the most efficient method in view point of speed and cost. Raman spectroscopy and XRD were useful for identification of diamond while Lang topography offered a good visualization method of the grain structure of polycrystalline black diamond roughs.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.4
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• pp.325-331
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• 2007

In this study, the inter-metal dielectric material of FSG was changed by low-k material in $0.13{\mu}m$ foundry-compatible technology (FCT) device process based on fluorinated silicate glass (FSG). Black diamond (BD) was used as a low-k material with a dielectric constant of 2.95 for optimization and yield-improvement of the low-k based device process. For yield-improvement in low-k based device process, some problems such as photoresist (PR) poisoning, damage of low-k in etch/ash/cleaning process, and chemical mechanical planarization (CMP) delamination must be solved. The PR poisoning was not observed in BD based device. The pressure in CMP process decreased to 2.8 psi to remove the CMP delamination for Cu-CMP and USG-CMP. $H_2O$ ashing process was selected instead of $O_2$ ashing process due to the lowest condition of low-k damage. NE14 cleaning after ashing process lot the removal of organic residues in vias and trenches was employed for wet process instead of dilute HF (DHF) process. The similar-state of SRAM yield was obtained in Cu/low-k process compared with the conventional $0.13{\mu}m$ FCT device by the optimization of these process conditions.

• The Journal of Advanced Prosthodontics
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• v.10 no.2
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• pp.93-100
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• 2018

PURPOSE. The purpose of this study was to determine the changing frequency of a diamond bur after multiple usages on 3 different surfaces. MATERIALS AND METHODS. Human premolar teeth (N = 26), disc shaped direct metal laser sintered CoCr (N = 3) and zirconia specimens (N = 3) were used in this study. Groups named basically as Group T for teeth, Group M for CoCr, and Group Z for zirconia. Round tapered black-band diamond bur was used. The specimens were randomly divided into three groups and placed with a special assembly onto the surveyor. 1, 5, and 10 preparation protocols were performed to the first, second, and third sub-groups, respectively. The subgroups were named according to preparation numbers (1, 5, 10). The mentioned bur of each group was then used at another horizontal preparation on a new tooth sample. The same procedure was used for CoCr and zirconia disc specimens. All of the bur surfaces were evaluated using roughness analysis. Then, horizontal tooth preparation surfaces were examined under both stereomicroscope and SEM. The depth maps of tooth surfaces were also obtained from digital stereomicroscopic images. The results were statistically analyzed using One-Way ANOVA, and the Tukey HSD post-hoc tests (${\alpha}=.05$). RESULTS. All of the groups were significantly different from the control group (P<.001). There was no significant difference between groups Z5 and Z10 (P=.928). Significant differences were found among groups T5, M5, and Z5 (P<.001). CONCLUSION. Diamond burs wear after multiple use and they should be changed after 5 teeth preparations at most. A diamond bur should not be used for teeth preparation after try-in procedures of metal or zirconia substructures.

• Journal of Korean Society for Quality Management
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• v.49 no.3
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• pp.433-446
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• 2021

Purpose: The main purpose of this study is to analyze the case of the transparent PET bottle resource circulation project of BYN Black Yak Co., Ltd., present implications, and propose ways to spread it in the future. Methods: In this study, the logic of the Double Diamond Model is applied to analyze the development process of sustainable fashion made from BYN Black Yak Co., Ltd.'s PET Bottle Resource Circulation System. Results: The K-rPET Resource Circulation Project of BYN Black Yak Co., Ltd. is recognized as a best example for its contribution to eco-friendly activities, solving social problems, raising consumer awareness, and sharing recycling habits. Before the plastic bottle becomes a garment, five steps are taken (discharge of PET bottle → collection of PET bottle → recycling of PET bottle → fabrication of yarn → production of the finished product out of the fabric). BYN Black Yak Co., Ltd. has successfully commercialized it by recycling reverse-recovery PET bottles by making solutions to problems that have not been solved at each stage. Conclusion: In addition to efforts to find and strengthen weak links presented in the Theory of Constrains (TOC), it appears to have systematically carried out activities to convert stakeholder discomforts into a package of gain points. As shown in the slogan "We are all in!" the proposal and implementation for the completion of a true environmental system is judged to have truly performed ESG management well for the company's business. ESG management activities at BYN Black Yak Co., Ltd. are expected to continue.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.349-352
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• 2005

In this paper, we have investigated the hydrogen effects on Diamond-like Carbon (DLC) as an LC alignment layer of the FFS mode. By change of a Hydrogen content in the DLC sputtering process, the image sticking and electro-optic characteristics of Black-White panel with DLC / IB technology were examined.

• Journal of the Korean institute of surface engineering
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• v.53 no.2
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• pp.80-86
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• 2020

This paper is concerned with type of imperfections present within the anodic oxide films on AA2024 and surface hardness of the anodic film measured after ink-impregnation. The anodic oxide films were formed for 25 min at 40 mA/㎠ and 15±0.5℃ and 300 rpm of magnet stirring rate in 20% sulfuric acid solution. The ink-impregnation allows clear observations of not only the imperfections within the anodic oxide films but also an indentation mark on the oxide film surface made by a pyramidal-diamond penetrator for the hardness measurement. There were observed four different regions in the anodic oxide films on AA2024 and the surface hardness of the anodic oxide films appeared to be crucially dependent on the type of defects, showing 60~100 H_v on the oxide surface region I with large size black defect, 100~140 H_v on the oxide surface region II with large size grey defect, 140~170 H_v on the oxide surface region III with mall size black and/or grey defects and 170~190 H_v on the oxide surface region IV without defects. The pyramidal indentation marks were observed to be distorted in the regions with a large size black and grey defects, while no distortion of the indentation mark was observed in the regions with small size defects and without visible defects.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.139-139
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• 1999

다이아몬드는 지구상에서 가장 단단한 물질로 잘 알려져 있을 뿐만 아니라 공업적 측면에서 볼 때, 여러 가지 특출한 성질들을 동시에 지니고 있다. 인장강도, 압축강도, 탄성계수 등 기계적 특성이 우수하고 넓은 광투과성과 내열, 내화학, 내방사성을 지니고 있으며, 열전도율이 높고 전기적으로 절연체이다. 또한 hole이동도가 높고 도핑에 의해서 반도체적 특성을 나타낸다. 이와 같이 매우 뛰어난 성질을 공업적으로 응용하기 위하여 이전부터 많은 연구가 행해져 왔으며, 1980년대에 들어와 박막이나 코팅 형태로의 합성이 가능한 기상합성법이 큰 발전을 보임으로써 다이아몬드의 우수한 특성을 여러 분야에서 폭넓게 응용할 수 있게 되었다. 특히 마찰 응용분야에 최적의 재료로 추천되고 있다. 지금도 Epitaxial 다이이몬드를 기지 위에 성장시키고 다결정질박막을 여러 가지 비다이아몬드(Si, W, Mo 등) 기지 위에 성장시키는 연구가 계속되고 있으며 공구강 위엥 경질코팅으로써 한층 개선된 다이아몬드박막 제조를 위한 수많은 연구노력들이 집중되고 있다. 그러나 일반탄소강에 다이아몬드박막을 성장시키기 위한 많은 노력들은 크게 바람직하지 않은 non-diamond carbon(black carbon or graphitic soot)의 형성 때문에 방해를 받고 있다. 계면에서 이들의 형성은 증착된 다이아몬드박막과 금속기지의 저조한 밀착력을 나타내게 된다. 이외 같이 다이아몬드박막의 응용을 위하여 다이아몬드피막에 요구되는 중요한 조건은 기지에 대해서 강한 밀착력을 나타내는 것이며, 동시에 상대물에 대하여 낮은 마찰계수를 가져야 한다. 그러나 다이아몬드와 금속기지는 서로 다른 열챙창계수(각각 0.87$\times$10-6K-1, 12$\times$10-6K-1)의 차이로 인하여 밀착력이 현저히 떨어진다는 단점으로 인해 산업화에 많은 제약을 받아왔다. 이러한 문제점을 해결하기 위하여 본 연구에서는 다이아몬드박막과 금속기지 사이에 중간층을 이용하는 방법을 제안하였다. 이러한 시도는 일반적으로 중간층 형성 금속인 Ti 또는 TiN 등이 적용되었으나 원하는 결과를 얻지 못하였다. 즉 carbon과 Fe의 상호확산, non-diamond carbon상의 형성 그리고 열잔류응력을 완화시키고 일반탄소강 위에 다이아몬드박막을 형성시켜 우수한 밀착력을 얻기 위한 목적에 미흡하였던 것이다. 이에 중간층으로 Cr 또는 Cr계 화합물 박막을 이용하였는 바, 이 중간층을 이용한 결과 우수한 밀착력을 나타내는 다이아몬드박막을 얻었으며 열적, 구조저으로 모재와 다이아몬드에 적합한 결과를 얻을 수 있었다. 본 연구에 의해 얻어진 결과들은 재료 가공을 위하여 높은 경도와 내마모성등이 요구되는 절삭공구나 금형의 수명 향항에 크게 기여할 것이며 산업적으로 큰 응용이 기대된다.