• Title/Summary/Keyword: SWARF

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Feasibility of Indium Tin Oxide (ITO) Swarf Particles to Transparent Conductive Oxide (TCO)

  • Hong, Sung-Jei;Yang, DuckJoo;Cha, Seung Jae;Lee, Jae-Yong;Han, Jeong-In
    • Current Photovoltaic Research
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    • v.3 no.2
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    • pp.50-53
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    • 2015
  • Indium (In) is widely used for transparent electrodes of photovoltaics as a form of indium tin oxide (ITO) due to its superior characteristics of environmental stability, relatively low electrical resistivity and high transparency to visible light. However, In has been worn off in proportion to growth the In related market, and it leads to raise of price. Although In is obtained from ITO target scarps, much harmful elements are used for the recycling process. To decrease of harmful elements, ITO swarf particles obtained from target scraps was characterized whether it is feasible to transparent conductive oxide (TCO). The ITO swarf was crushed with milling process, and it was mixed with new ITO nanoparticles. The mixed particles were well dispersed into ink solvent to make-up an ink, and it was well coated onto glass substrate. After heat-treatment at $400^{\circ}C$ under $N_2$ rich environments, optical transmittance at 550 nm and sheet resistance of the ITO ink coated layer was 71.6% and $524.67{\Omega}/{\square}$, respectively. Therefore, it was concluded that the ITO swarf was feasible to TCO of touch screen panel.

An Analysis of Aerosol Direct Radiative Forcing Using Satellite Data in East Asia During 2001-2010 (위성자료를 이용한 2001-2010년 동안의 동아시아 지역 에어로졸 직접복사강제력 분석)

  • Jeong, Ji-Hyun;Kim, Hak-Sung;Kim, Joon-Tae;Park, Yong-Pil;Choi, Hyun-Jung
    • Journal of Environmental Science International
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    • v.22 no.8
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    • pp.1053-1062
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    • 2013
  • The shortwave aerosol direct radiative forcing (SWARF) was analyzed using the Clouds and Earth's Radiant Energy System (CERES) data in the East Asian region from 2001 to 2010. In the Yellow Sea and the Korean Peninsula, located in the leeward side of China, significantly negative high SWARF at the top of atmosphere (TOA) occurs due to the long-range transport of anthropogenic (e.g. sulphate) and natural aerosols (e.g. mineral dust) from the East Asian continent. Conversely, eastern China has much higher levels of SWARF at the surface (SFC) due to anthropogenically emitted aerosol than in the Yellow Sea and the Korean Peninsula. Since the radiative forcing of aerosols in the atmosphere are different in type, aerosol types were classified into sea salt+sulphate, smoke, sulphate and dust by using satellite data. The analysis on the SWARF by the classified aerosol types indicated that sulphate occupies a predominant portion of the atmosphere in the Yellow Sea and the Korean Peninsula in the summer. In particular, the annual averages of the summer TOA SWARF increased in the Yellow Sea and the Korean Peninsula from 2001 to 2010.

Desorption Characteristics of Grinding Oil from Swarf by using Supercritical Carbon Dioxide (초임계 이산화탄소를 이용한 스와프로부터 연마유 탈착 특성)

  • Yang, Jun Youl;Lee, Youn-Woo;Lim, Jong Sung
    • Clean Technology
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    • v.10 no.3
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    • pp.139-148
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    • 2004
  • The recovery of stainless steel fiber by removing cutting oil from grinding swarf, which is classified as specified wastes, was investigated. Swarf loaded with grinding oil was regenerated by supercritical carbon dioxide. And, the effects of temperature(313.15K-323.15K), pressure(10MPa-30MPa) on regeneration efficiency were studied. Regeneration effiency was increased as the pressure was increased. Also, at the same pressure, the experiments at higher temperature were more efficient for regeneration. The experiment results was predicted by applying a one-parameter mathematical model assuming linear desorption kinetics. The predicted value showed good agreement with experimental data.

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Matrix Composition Effect on the Wear Behavior of Diamond Segments

  • Unal, Rahmi;Gurcay, Alper
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1311-1312
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    • 2006
  • Diamond tools were fabricated by cold pressing and sintering under pressure at the temperature up to $750^{\circ}C$. Investigation of the microhardness behaviour of the segments was showed that increasing the cobalt ratio causes the increase of the hardness of the matrix material. This caused to decrease of the wear rate of the matrix. Because the matrix wears more slowly than the diamonds, the space between the cutting edges and the matrix is constantly reduced. The swarf cannot be carried away properly, and the segment will continuously lose its ability to cut with higher cobalt contents.

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Effect of Evaporative Pattern on the Surface Layer Structures of Carbon Steel and Gray Iron Castings. (소실모형이 탄소강 및 회주철 주물의 표면층 조직에 미치는 영향)

  • Kim, Ji-Youn;Cho, Nam-Don
    • Journal of Korea Foundry Society
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    • v.12 no.4
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    • pp.305-316
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    • 1992
  • Steel and iron castings made with expandable polystylene (referred to hereafter as EPS) patterns are often affected by distinctive defects associated with incomplete decomposition of the EPS as the molds are filled with metal. The effects of practical factors on carbon pick-up were investigated on the specimens, by taking successive layers of swarf and analysis, whereas the lustrous carbon is determined by using combustion analysis. The quality of the castings, with particular reference to carbon pick-up in low carbon steel and lustrous carbon on gray iron, is further influenced to a significant extent by such practical factors as reduced pressure, the pouring temperature, the density of EPS pattern, the additive in coating and in pattern and the casting thickness. The rate at which carbon pick-up and lustrous carbon deposites are formed can be reduced by reducing the density of the pattern and also reducing pressure, especially by adding $Na_2CO_3$ in coating and in pattern to promote $CO_2$ evolution. The upper parts of castings obtained using EPS patterns are slightly higher in carbon pick-up and in lustrous carbon than other parts.

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CFD Analysis on Flow Characteristics of Oil Film Coating Nozzle (유막 코팅 노즐의 유동특성에 관한 CFD해석)

  • Jung, Se-Hoon;Ahn, Seuig-Ill;Shin, Byeong-Rog
    • The KSFM Journal of Fluid Machinery
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    • v.11 no.5
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    • pp.50-56
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    • 2008
  • Metal cutting operations involve generation of heat due to friction between the tool and the pieces. This heat needs to be carried away otherwise it creates white spots. To reduce this abnormal heat cutting fluid is used. Cutting fluid also has an important role in the lubrication of the cutting edges of machine tools and the pieces they are shaping, and in sluicing away the resulting swarf. As a cutting fluid, water is a great conductor of heat but is not stable at high temperatures, so to improve stability an emulsion type mixed fluid with water and oil is often used. It is pumped over the cutting site of cutting machines as a state of atomized water droplet coated with oil by using jet. In this paper, to develop cutting fluid supplying nozzle to obtain ultra thin oil film for coating water droplet, a numerical analysis of three dimensional mixed fluid Jet through multi-stage nozzle was carried out by using a finite volume method. Jet flow characteristics such as nozzle exit velocity, development of mixing region, re-entrance and jet intensity were analyzed. Detailed mixing process of fluids such as air, water and oil in the nozzle were also investigated. It is easy to understand complex flow pattern in multi-stage nozzle. Important flow Information for advance design of cutting fluid supplying nozzle was drawn.

Effect of Coating Materials on Surface Layer Structures of Austenitic Stainless Steel Castings in Evaporative Pattern Process (소실모형 주조법에서 도형제가 오스테나이트 스테인레스강 주물의 표면층조직에 미치는 영향)

  • Kim, Ji-Youn;Cho, Nam-Don
    • Journal of Korea Foundry Society
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    • v.15 no.6
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    • pp.604-615
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    • 1995
  • Austenitic stainless steel castings using expandable polystylene(referred to hereafter as EPS) patterns are often affected by distinctive defects associated with incomplete decomposition of the EPS as the molds are filled with metal. The quality of the castings, with particular reference to carbon pick-up in austenitic stainless steel is further influenced to a significant extent by such factors as reduced pressure, the additive by adding $Na_2CO_3$ in coating. The steel composition and microstructure were examined at the surface layer of castings, at depths of 1mm, by taking successive layers of swarf and analysis. In experiments, the carburizing atmosphere was neutralized, showing that the coating performed efficiently by decomposing almost instantly on heating and liberating $CO_2$. The upper parts of castings obtained using EPS patterns were slightly higher in carbon pick-up than other parts. Comparing the 316L and 304 stainless steel castings, qualitative and quantative differences could be found between the carbon pick-up behaviours as influence of the carbon content and alloying elements. Carbide former such as Cr makes carbon more soluble in the steel. This must make carbon pick-up in the surface layer but at the same time richer in carbon especially in the 304 stainless steel castings.

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A Study on the Environment Conscious Machining Process Using Compressed Dry Cooling Air (건식 저온 압축 공기를 이용한 절삭유 대체형 가공 공정 방식에 관한 연구)

  • 강재훈;송준엽;박종권;노승국
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.129-132
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    • 2003
  • Used cutting fluid from machining processes is harmful to both environment and human health. Chemical substances that provide the lubrication function in the machining process are toxtc to the environment if the cutting fluid is released to soil and water and caused serious health problems to workers who are exposed to the cutting fluid in both liquid and mist form. Recently. cost of using cutting fluid is increasing as the number and the extensiveness of environmental protection laws and regulations increase. Therefore, the use of cutting fluid in machining processes place an enormous burden on manufacturing companies to cover the additional costs associated with their use and protection of our environment. Current trends in manufacturing are focused on minimizing or eliminating the use of metalworking fluids in machining processes. And the increased costs for the disposal of waste products (swarf, coolants and lubricants), especially in industrially developed countries, has generated interest in dry machining. A variety of new techniques are testimony that new technology has rationalized further efforts to research and implement dry machining processes. This paper presents the developed equipment, the process optimization and the applications in the field of surface grinding for the new cryogenic dry machining using a compressed cooling air. The investigated new machining process method shows many advantages compared to conventional techniques with cutting fluid.

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Analysis of Cutter and Design of Chip Processing System for Large Scale Machine Tool (대형 공작기계용 칩 처리시스템 설계 및 커터 해석)

  • Lee, Jong-Moon;Yang, Young-Joon
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.4
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    • pp.147-153
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    • 2012
  • The demands of the large scale machine tools, for instance, such as planomiller, turning machine, boring machine, NC machine, have been gradually increased in recent years. As the performances of machine tools and/or cutting tools are advanced, it is possible to perform high-speed and high-precision cutting works. The effective treatment of wet chip, which is discharged from cutting works, becomes very important problems. Therefore, this study is forced on the design of large scale machine tools using CATIA V5R18 and analysis of cutter, which is considered as essential equipment in large scale machine tools, using MSC.Nastran & MSC.Patran. Especially, the relations between tolerated load of cutter, driving horse power and rpm of driving shaft in chip processing system are investigated through analysis. As the results, the reliability of design could be improved by evaluating simulated numerical values, it showed that tolerated loads of supported part and edged part of cutter are 87,000N and 14,450N, respectively.

A Study on the Prediction of the Form of Chips using Cutting Forces (절삭력을 이용한 칩형태의 예측에 관한 연구)

  • Lee, Sang-Jun;Choi, Man-Seong;Song, Ji-Bok
    • Journal of the Korean Society for Precision Engineering
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    • v.5 no.1
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    • pp.40-49
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    • 1988
  • The chip control problem is one of the important subjects to be studied in the metal cutting process. Especially, an important practical problem concerns the form of chips pro- duced in machining since this has important implications relative to : 1. Personal safety. 2. Possible damage to equipment and product. 3. Handling and disposal of swarf after machining. 4. Cutting forces, temperatures, and tool life. However, a dependable way to predict the form of chips in a wide range of cutting conditions has not been established satisfactorily. In this paper, the relationship between the form of chips and the ratios of cutting forces were studied experimentally. According to what the experiments have been carried out in the turning process the main results can be summarized as follows : 1. By use of the multiple linear regression model, emperical formulas which are suitable to wide ranges of cutting conditions with accuracy were obtained satisfactorily. 2. The correlations between the form of chips based upon the classification by Henriksen and the ratios of cutting forces, namely (feeding force/thrust force), (principal force/feeding force) were determined. 3. Using above results, the algorithms which predict the form of chips were constituted. With these algorithms, the form of chips in a wide range of cutting of cutting conditions can be predicted.

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