• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.24-24
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• 2007

Aerosol deposition(AD) method is a emerging technology for the room temperature deposition of the dielectric thin films with high quality. In this study, $Al_2O_3$ thin films were deposited by aerosol deposition method directly from raw powders. To get uniform and smooth film surface, Process parameters such as gas consumption rate, nozzle-substrate distance and vibration speed were optimized. From XRD results, $Al_2O_3$ thin films have the same crystal structures with starting powders. $Al_2O_3$ thin films also showed dense microstructure. Electrical properties of the thin films were also investigated.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.685-688
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• 2000

Pulse plating is about to deposit material at high current density compared to conventional DC plating. For example pulse plating can get more fine grain can improve adhension and metal distribution and current efficiency can reduce internal stress and crack. therefore we studied pulsed power supply which has high current density and improve deposition quality and increase plating speed in this paper.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.126-126
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• 2012

In past decades, the themal inkjet (TIJ) printer has been widely used as one of the most well-known digital printing technology due to its low cost, and high printing quality. Since the printing speed of TIJ printers are much slower than that of laser printers, however, there has been intensive efforts to raise the printing speed of TIJ printers. One of the most plausible methods to raise the printing speed of TIJ printers is to adopt a page-wide array TIJ printhead. To accomplish this goal, the high efficiency inkjet heating resistor films should be developed to settle the high power consumption problem of a page-wide array TIJ printhead. In this study, we investigated noble metal based multicomponent thin film resistor films prepared by atomic layer deposition (ALD) for a high efficiency inkjet printhead. Design concept, preparation, material properties of noble metal based multicomponent thin films will be discussed in terms of mutlfunctionality.

• Corrosion Science and Technology
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• 제10권6호
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• pp.194-198
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• 2011

This is the first release of an interim report on the development of coating technology of Zn-Mg alloy layers on steel strip by EML-PVD (electromagnetic levitation - physical vapor deposition) process in an air-to-air type continuous PVD pilot plant. It intends to introduce a basic principle of the EML-PVD process together with the high speed PVD pilot plant built in Posco. Due to the agitation effect provided by the high frequency induction coil, simultaneous evaporation of Zn and Mg from a droplet could produce alloy coating layers with Mg content of 6% to 12% depending on the composition of the droplet inside the coil. For its superior corrosion resistance, Zn-Mg alloy coated steel would be a very promising material for automotive, electrical appliances, and construction applications.

• 한국세라믹학회지
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• 제50권6호
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• pp.533-538
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• 2013

Silicon carbide (SiC) materials are typical ceramic materials with a wide range of uses due to their high hardness and strength and oxidation resistance. In particular, due to the corrosion resistance of the material against acids and bases including the chemical resistance against ionic gases such as plasma, the application of SiC has been expanded to extreme environments. In the SiC deposition process, where chemical vapor deposition (CVD) technology is used, the reactions between the raw gases containing Si and C sources occur from gas phase to solid phases; thus, the merit of the CVD technology is that it can provide high purity SiC in relatively low temperatures in comparison with other fabrication methods. However, the product yield rarely reaches 50% due to the difficulty in performing uniform and dense deposition. In this study, using a computational fluid dynamics (CFD) simulation, the gas velocity inside the reactor and the concentration change in the gas phase during the SiC CVD manufacturing process are calculated with respect to the gas velocity and rotational speed of the stage where the deposition articles are located.

• Nuclear Engineering and Technology
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• 제44권8호
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• pp.939-944
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• 2012

Deposition potential, deposition time, square wave frequency, rotation speed of the rotating disc electrode, and palladium concentration were studied on a Glassy Carbon Electrode (GCE) in 0.01M HCl for the determination of palladium in High Level Nuclear Waste (HLNW) by anodic stripping voltammetry. Experimental conditions were optimized for the determination of palladium at two different, $10^{-8}$ and $10^{-7}M$, levels. Error and standard deviation of this method were under 1% for all palladium standard solutions. The developed technique was successfully applied as a subsidiary method for the determination of palladium in simulated high level nuclear waste with very good precision and high accuracy (under 1 % error and standard deviation).

• 한국환경과학회지
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• 제11권7호
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• pp.651-662
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• 2002

Weather elements were observed by the AWS (Automatic Weather System) and dustfall particles were collected by the modified American dust jar (wide inlet bottle type) at 4 sampling sites in Busan area from March. 1999 to February, 2000. Thirteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Si, and Zn) were analyzed by AAS and ICP. The purposes of this study were to estimate qualitatively various bulk deposition flux of dustfall and insoluble components by applying regional and seasonal wind intensity. Frequency of wind speed were found in order of low(1-3m/s), very low(<1m/s), medium(3-8m/s) and high(>8m/s), and annual mean had higher range at low(1-3m/s) for 56.3%. Strong negative linear correlation were observed between dustfall and wind direction (northeastern and eastern), but strong positive linear correlation were observed between dustfall and wind direction (western and northwestern) at industrial, commercial and coastal zone(p<0.05). While a negative correlation were observed between wind speed frequency of very low(<1 m/s) and dustfall, and positive correlation were observed between wind speed frequency of low(1-3m/s) and dustfall in coastal zone(p<0.05). The correlation coefficient was observed 0.556 between wind speed frequency of low(1-3m/s) and Ni by commercial zone(p<0.05). The correlation coeffcient show well-defined insoluble trace metals (Al, Ca, Cr, Cu, Fe, Pb, and Zn) and wind speed frequency of low(1-3m/s) at coastal zone, which was found significant difference(p<0.01).

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2009년도 춘계학술대회 논문집
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• pp.151-152
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• 2009

We coated $TiO_2$ thin films on particles by a rotating cylindrical plasma chemical vapor deposition (PCVD) process and investigated the effects of various process variables on the morphology and growth of thin films. The polypropylene (PP) particles were rotated with the cylindrical PCVD reactor and they were coated with $TiO_2$ thin films uniformly by the deposition of thin mm precursors in the gas phase. The $TiO_2$ thin films were coated on the PP particles uniformly and the thickness of thin films almost proportional to the deposition time. The $TiO_2$ thin films grew more quickly on the PP particles with increasing rotation speed of the reactor. This study shows that a rotating cylindrical PCVD reactor can be a good method to coat high-quality $TiO_2$ thin films uniformly on particles.

• 한국치위생학회지
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• 제5권2호
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• pp.219-233
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• 2005

This study was conducted on 185 workers at 73 dental clinics and university hospitals in Daegu to investigate the actual prevention of infection and vaccination against B-type hepatitis among dental workers. 1. According to the result of medical examination, only 35 out of 144 (24%) dental clinic workers had periodic health examination while 7 out of 9 (78%) university hospital workers did. 2. In a survey on vaccination against B-type hepatitis, 52 workers aged 29 or younger (96.3%), 38 dental hygienists (51.9%) and 44 dental workers at dental clinics (81.5%) have not had any vaccination against B-type hepatitis. The rest appeared to have had vaccination or be aware that they had antibody against B-type hepatitis without having to have any vaccination. 3. According to the result of a survey on the existence of antibody by job, 42 (56%) of dental hygienists, 15 (20%) of assistant nurses, 12 (16%) of medical assistants and 6 (8%) of dental technicians did not know whether or not they had antibody. This suggests that all types of dental workers except dental hygienists have low awareness of whether or not they have antibody. 4. In a survey on the relation between general characteristics of subjects and the sterilization of dental equipment, alcohol disinfection of high speed handpiece and low speed handpiece was most common among dental workers aged 29 or younger, and all of those aged over 40 used autoclave. By position, alcohol disinfection was used most commonly for high-speed handpiece. antiseptic solution deposition for disposable suction lips, and autoclaving for impression. By workplace, dental workers at university hospitals used autoc1aving most frequently for high/low speed handpiece while those at dental hospitals and dental clinics used alcohol disinfection most frequently and even some respondents replied that they did not disinfect. For metal cups, workers at dental clinics and dental hospitals did not use any sterilizing method while those at university hospitals used autoclaving. For disposable suction tips, workers at dental clinics used antiseptic solution deposition and those at dental hospitals used alcohol disinfection but some respondents replied that they did not disinfect. For metal suctions and impression trays, autoclaving was most common in all workplaces but some dental clinics replied that they did not disinfect impression trays. According to work experience, alcohol disinfection was most common for high/low speed handpiece. For disposable suction tips, dental workers with 3 years' or shorter work experience, those with 3~6 years' experience and those with 9~12 years' experience used antiseptic solution deposition most commonly, and many of those with 6~9 years replied that they did not disinfect. The results of this study stated above suggest that systematic education is necessary for all dental workers for enhancing th eir awareness of B-type hepatitis and the prevention of infection. Moreover, dental workers are required to make efforts to prevent infection with B-type hepatitis voluntarily and actively.

• 한국정밀공학회지
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• 제25권7호
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• pp.124-130
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• 2008

The effect of nitrogen gas pressure in arc ion plating on surface properties of the TiN-coated high speed steel(SKH51) is presented in this paper. The surface roughness, micro-particle, micro-hardness, coated thickness, atomic distribution of TiN, and adhesion strength are measured fur various nitrogen gas pressures. It has been shown that the nitrogen gas pressure has a considerable effect on the surface roughness, adhesion strength, atomic distribution of TiN, and surface deposition of TiN of the high speed steels but that it has little influence on the micro-hardness and coated thickness.