• 한국표면공학회지
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• 제40권1호
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• pp.11-15
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• 2007

Stable metallic Cu/Zn nanoparticles were prepared in the base oil phase by hydrothermal method. The physical properties, such as crystal structure, crystallite size and crystallinity according to synthesis conditions have been investigated by XRD, FT-IR and TEM. In addition, 4-ball test has been performed in order to investigate the frictional wear properties of prepared nanosized Cu/Zn particles. The peaks of the X-ray diffraction pattern indicate that the particle size was very small and crystallinity of Cu/Zn particles was good. The micrographs of TEM showed that nanosized Cu/Zn particles possessed a spherical morphology with a narrow size distribution. The crystallite size of the Cu/Zn particles synthesized in base oils was 23-30 nm. It was found that the antiwear capacity increases with increasing Cu/Zn concentration. When the concentration of Cu/Zn was 5.0 wt%, the wear scar diameters was 0.38 mm.

• 한국주조공학회지
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• 제28권4호
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• pp.184-189
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• 2008

Ag-Cd alloy has been widely used as an electrical contact material, since Ag-Cd alloy has a good wear resistance and stable contact resistance. But nowadays Ag-Cd alloy is not considered as electrical contact material any more due to detrimental effect on environments. Currently, active researches are being performed on ($Ag-SnO_2$ and $Ag-SnO_{2}-In_{2}O_{3}$) as an alternative solution which can fix the remaining environmental problems. However, $In_{2}O_{3}$ is relatively expensive and Ag-Sn alloy has low wear resistance. Our recent research results show that Ag-X%Zn-Y%Sn has similar physical and chemical properties. In the present study, so we tried to change and to optimize the Zn oxide content to over 6 wt% and Sn oxide content with 0.5, 1.0, 1.5 wt%. Results obtained from the experiments on the Ag-X%ZnO-Y%$SnO_2$ are discussed.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.184-188
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• 2008

It has been recognized that friction coefficient decreased with decreasing viscosity of oil in lubrication. In general, the more viscosity decreases, the more wear rate increases due to decrease load carrying capacity. It has been proposed that nano particles in oil decrease friction coefficient and wear rate. The purpose of this study is to apply oil of lower viscosity that mix with nano particles at the compressor used in a refrigerator to decrease friction coefficient keeping Load carrying capacity. Mineral oil of 8 cSt were used and mixed with nano particle. Friction coefficient was evaluated by a disk-on-disk tester. As a result, friction coefficient of nano oil decreased by 90% in comparison with raw oil. These results lead us to the conclusion that nano oil is new plan to raise efficiency of the compressor.

• 대한금속재료학회지
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• 제46권7호
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• pp.443-448
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• 2008

Contact materials are used in many electrical devices. Ag-Cd alloy has been widely used in electrical part, because Ag-Cd alloy has a good wear resistance and stable contact resistance. But nowadays Ag-Cd alloy isn't being used because of environmental challenges. Currently new research is being done on ($Ag-SnO_2$ and $Ag-SnO_2-In_2O_3$) as an alternative solution to fix any remainly environmental challenges. However $In_2O_3$ is more expensive and Ag-Sn alloy has low wear resistance. According to our research data Zn has a similar physical and chemical property. In this work, so we changed and optimized the Zn oxide to over 4 and added Sn oxide ratio 0.5, 1.0, 1.5wt%. Conclusions from the data recorded from the experiment of $Ag-ZnO-SnO_2$ are as follows.

• Tribology and Lubricants
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• 제36권6호
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• pp.297-306
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• 2020

This paper reviews studies on the types and functions of oil sensors used for machine condition monitoring. Machine condition monitoring is essential for maintaining the reliability of machines and can help avoid catastrophic failures while ensuring the safety and longevity of operation. Machine condition monitoring involves several components, such as compliance monitoring, structural monitoring, thermography, non-destructive testing, and noise and vibration monitoring. Real-time monitoring with oil analysis is also utilized in various industries, such as manufacturing, aerospace, and power plants. The three main methods of oil analysis are off-line, in-line, and on-line techniques. The on-line method is the most popular among these three because it reduces human error during oil sampling, prevents incipient machine failure, reduces the total maintenance cost, and does not need complicated setup or skilled analysts. This method has two advantages over the other two monitoring methods. First, fault conditions can be noticed at the early stages via detection of wear particles using wear particle sensors; therefore, it provides early warning in the failure process. Second, it is convenient and effective for diagnosing data regardless of the measurement time. Real-time condition monitoring with oil analysis uses various oil sensors to diagnose the machine and oil statuses; further, integrated oil sensors can be used to measure several properties simultaneously.

• 한국환경과학회지
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• 제32권9호
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• pp.627-634
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• 2023

Tire wear particles(TWPs), regarded as a microplastic, is generated in significant quantities each year and exist in various spaces and have a negative impact on the surrounding environment. Particularly, roadside environments fall within the direct influence of TWPs, necessitating proactive investigation for contamination management and response. Therefore, this study aimed to investigate the soil acidity and electrical conductivity(EC) and TWPs in the roadside soil of six sites based on traffic volume. The analysis revealed that the soil in all sites exhibited subacidity, and there were no significant differences in EC. Microscopic and FT-IR analysis revealed the presence of microscopic particles in soil samples that exhibited common visual characteristics of TWPs. In the road with the highest traffic volume, 48,300 TWPs were detected per unit area. Furthermore, a proportional relationship between traffic volume and TWPs particles was established. However, influences other than traffic volume on TWPs particle count within the soil were observed. Therefore, for the management of TWPs contaminated roadside soil, a proactive response is necessary in areas with high traffic volumes. However, in order to effectively address the factors contributing to the generation and dispersion of TWPs, further research is required with a multidimensional approach.

• 한국산업융합학회 논문집
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• 제27권3호
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• pp.693-699
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• 2024

The main cause of scattering dust generated by transportation equipment such as automobiles was largely due to exhaust gas from internal combustion engines in the past, but it was generally recognized that non-exhaust causes such as abrasion of the tires or brake pads were low. Accordingly, scattering dust generated by exhaust gas has consistently existed in many studies, such as technological progress and related regulations, but research on non-exhaust is relatively insignificant, and the need for research on scattering dust generated by non-exhaust is emerging. In this study, a dust collector that can be easily mounted on a caliper to collect scattering dust generated by pad wear during the brake operation of an automobile was manufactured. In this study, we developed a dust collector that is easy to mount on calipers to collect scattering dust caused by pad wear during brake operation of automobiles. According to the installation of the manufactured dust collector, the performance of scattering dust by brake operation and the temperature change characteristics of calipers according to the structure of the dust collector were evaluated.

• Composites Research
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• 제30권5호
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• pp.310-315
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• 2017

본 연구에서는 액상가압공정을 통해 고체적율의 SiC 입자가 균일 분산된 알루미늄 금속복합재료를 제조하고, 미세조직, 기계적 특성 및 내마모 특성에 대해 분석하였다. 입자크기가 다른 이종 SiC 입자가 약 60 vol.% 이상의 체적율로 균일하게 분산된 SiC/Al7075 복합재료는 단일 SiC 입자로 강화된 복합재료에 비해 체적율이 약 12% 이상 높았으며 압축강도가 200 MPa 이상 증가하였다. 내마모시험 결과 이종 SiC 입자 금속복합재료의 경우 마모너비와 깊이가 각각 $285.1{\mu}m$, $0.45{\mu}m$이며, 마찰계수는 0.16으로 내마모 특성이 가장 우수하였다.

• 한국습지학회지
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• 제9권3호
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• pp.35-42
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• 2007

최근 환경부의 환경정책은 수질오염총량관리제도의 전국적인 확대를 앞두고 다양한 토지이용에서 발생되는 비점오염물질의 관리를 추진하고 있다. 이러한 환경정책의 변화와 함께 4대강 수계에 비점오염원 시범사업을 통해 다양한 비점오염저감시설의 효율평가 및 시설의 유지관리에 대하여 모니터링도 수행하고 있다. 따라서 본 연구는 한강수계에 설치된 비점오염 저감시설 중에서 전처리 시설로 설치되어 있는 침강지 또는 침사지 퇴적물의 물리화학적 성상을 연구함으로써 폐기물로써의 퇴적물 관리에 대한 기초자료를 제시하고자 한다. 일반적으로 비점저감시설의 전처리 시설로 사용되는 침강지는 일정한 체류시간을 제공함으로써 강우유출수내의 입자상 물질을 제거함과 동시에 비점저감시설 내의 여과재 및 침투재의 폐색을 예방하고자 설치되는 전처리 시설이다. 침강지 퇴적물의 물리화학적 특성 연구 결과에 의하면, 일반적으로 Zn과 Cd은 $75{\mu}m$이하의 퇴적물 입도분포에서 입자 표면적으로의 흡착농도가 높은 것으로 나타났다. 중금속 부하량을 살펴본 결과, 입자의 크기가 $425-850{\mu}m$범위 일 경우 중금속 농도가 가장 높게 나타났다. 전체 중금속에 대한 분석 결과, Cu, Zn, Pb의 중금속 함량이 입도분포 $425-850{\mu}m$ 사이에서 30% 이상을 나타내었다. 중금속 중에서 다른 항목에 비하여 Cu, Pb 및 Zn의 함량이 높게 나타났는데, 이는 차량의 타이어와 엔진파트에 이러한 중금속이 많이 함유되어 있기 때문이다. 또한 본 연 구결과 침강지는 퇴적물의 퇴적과 함께 다양한 중금속의 제거가 발생하는 것으로 나타났다.

• Elastomers and Composites
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• 제54권4호
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• pp.330-334
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• 2019

Cryogenic crushing techniques have been employed for recycling waste rubber articles and for extracting residual organic additives present in rubber samples. Rubber particulate derived from tire tread abrasion is one of the key components of road dust. Therefore, in this work, we prepared rubber particulates using a cryogenic crusher and characterized their shapes as well as size distributions according to the type of rubber. The rubber particulates exhibited uneven surfaces with the presence of some small pieces. The order of the particle size distribution was observed to be: NR > BR > SBR. Subsequently, carbon black was added; this led to a decrease in the particle size and the shape becoming rougher. The crushed particulates of the carbon black-filled samples comprised agglomerated shapes of small pieces, which were similar in shape to that of wear debris in tire tread. It was discovered that crosslink density was one of the principal factors that led to the formation of small crushed particulates. The small particulates obtained by cryogenic crushing can be utilized as model rubber particulates for researching micro dust.